Molecular medicine focus on understanding the diseases based on molecular level, and developing personalized medicine strategies for diagnostics and therapeutics. However, powerful molecular recognition tool is still limited for cancer diagnosis and therapy, which impeding cancer research. Aptamers are generated from systematic evolution of ligands by exponential enrichment (SELEX) also known as in vitro selection, ranging from synthetic single-stranded DNA, RNA or XNA (enhanced modified nucleotides), HNA (nucleotides of specific structures such as G quadruplex). The main advantages of aptamers including high specificity, high affinity, simple and rapid synthesis, easy chemical modification, wide target range, good tissue penetration and low immunogenicity. As a molecular recognition tool in molecular medicine, aptamer shows wide applications in developing personalized prediction, diagnosis and therapeutics for its high specificity and high affinity against target. This review discusses the applications of aptamers in disease diagnosis, including aptamer-based tumor marker discovery, liquid biopsy, and molecular imaging, Moreover, the applications of aptamer-based cancer therapy are reviewed, including aptamer-based inhibitors, aptameric drug conjugates, nanomedicines, and aptamer-mediated immunotherapy. Finally, it is promising aptamer will be extensively employed in the future including fundamental research, diagnosis and therapeutics. However, following issues are still need to be addressed. First, the application scenarios-dependent SELEX procedures lack studying which limits the clinical applications of aptamers. Second, the structure of aptamer-target complex has not been fully elucidated, which restricts the precise regulation of aptamers. Third, aptamer is easily degraded by enzymes in vivo and has a short half-life period, which hinders the applications of aptamer-drug conjugates in the development of targeted drugs. With the advancement of screening technology and the further enhancement of aptamer performance, it is expected that aptamers will find more extensive utilization in the field of molecular medicine in the future.
Nucleic acid aptamers are a class of single-stranded DNA or RNA molecules with specific molecular recognition capability, obtained by a process called systematic evolution of ligands by exponential enrichment (SELEX). They have the advantages of high thermal stability, ease of chemical synthesis and modification, and low immunogenicity compared to antibodies, and have attracted widespread interest in many fields such as bioanalysis, biomedicine, and biotechnology. High-quality aptamers are the basis of applications, however, the number of them that meet requirements of practical applications is very limited. How to obtain aptamers with high affinity, high specificity, and high in vivo stability is the technical bottleneck in the field of aptamers. Firstly, this review briefly introduces the basic theory of SELEX and its critical experimental steps including design of nucleic acid library, monitoring selection process, preparation of secondary library, sequencing and screening of candidate aptamers. The six main research directions of SELEX during the past thirty years are then concluded. They are respectively (1) how to improve the specificity of aptamers, (2) how to improve the stability of aptamers against nuclease degradation, (3) rapid SELEX, (4) how to isolate aptamers for complex targets, (5) how to isolate small molecule-binding aptamers, and (6) how to isolate high affinity aptamers. The development of rapid SELEX technologies has attracted tremendous attention and almost all physical separation methods have been applied to improve the SELEX efficiency. Very recently, several methods involving the highly efficient chemical reactions have been reported, providing novel strategies for the rapid isolation of aptamers. The key research progresses of SELEX technologies suitable for the isolation of small molecule-binding aptamers are subsequently reviewed and the challenges of each method are critically commented. There are three types of SELEX methods including the target-immobilized SELEX, library-immobilized SELEX (Capture-SELEX), and homogeneous SELEX (GO-SELEX). Even though the target-immobilized SELEX suffers from many issues such as steric hindrance, it is still a popularly used method due to its simplicity. In recent years, Capture-SELEX has been widely applied. The experimental conditions of Capture-SELEX (concentration of positive-SELEX target, choice of negative-SELEX targets and their concentrations) and the affinity (KD,dissociation constant) and the specificity of the isolated aptamers for the 36 targets are listed in a table. Based on the information from the table, the effect of the experimental conditions on the affinity and the specificity is discussed. The statistical data indicates that the lower concentration of the positive-SELEX targets favors the isolation of the higher affinity aptamers, while it is not a necessary condition. Negative-SELEX is currently the dominant strategy to improve the specificity of aptamers. However, the specificity of many aptamers cannot meet the requirement for practical applications. The choice of negative-SELEX targets and their concentrations in each case are quite different. In 20 out of the 36 targets, no negative-SELEX was performed for the aptamer isolation. How to obtain the aptamers with high specificity is the most difficult challenge for small molecule targets. It is in urgent need to establish novel strategies beyond negative-SELEX to improve the specificity of aptamers. The experimental conditions of GO-SELEX and the KD and the specificity of the isolated aptamers for the 13 small molecule targets are also list for comparison. The comparison data shows the less numbers of the enrichment cycles required for GO-SELEX than Capture-SELEX, while the obtained aptamers all commonly have KD in the nanomolar range. The lower enrichment efficiency of Capture-SELEX should be due to the self-dissociation of the immobilized library. The affinity evaluation is the important part of the characterization of aptamer structure and performance. More than ten affinity assays are frequently used for aptamer characterization, which are roughly divided into three categories: separation-based, immobilization-based, and homogeneous methods. All techniques could generate false-positive and false-negative results. Taking gold nanoparticle-based colorimetric assay and isothermal thermal titration as examples, we review the technical progresses and comment on the fundamental reasons resulting in the inconsistent results when the different affinity assays are conducted. The final part of this review provides an outlook on the future trends of aptamer isolation technologies, affinity characterization techniques, and the technical standardization.
JIA Hai-Jing, GAO Ya-Jing, LOU Xin-Hui.Review: Main Research Directions, Advances and Challenges in Nucleic Acid Aptamer Isolation and Affinity Evaluation Technologies[J].,2023,50(9):2051-2076.Export: BibTexEndNote
Renal carcinoma is one of the most common tumors in the urinary system, and its incidence is on the rise. Renal cell carcinoma, as the main type of renal tumor, has a high frequency of local invasion and distant metastasis, and about 33% to 50% of patients with renal cell carcinoma have metastases at the time of discovery. Since there are no specific signs and symptoms in the early stage of renal cell carcinoma, the main treatment is surgical resection, insensitive to radiotherapy and chemotherapy, and the therapeutic means are limited, the early diagnosis of renal cell carcinoma can greatly improve the chances of effective treatment of renal cell carcinoma, which is of great significance for the effective treatment of renal cell carcinoma. Aptamers are oligonucleotide fragments obtained from nucleic acid molecular libraries by systematic evolution of ligands by exponential enrichment (SELEX). It can selectively bind to small molecular ligands or high affinity protein targets, and has high affinity and specificity to target molecules or cells, and has been widely used in tumor imaging diagnosis and targeted therapy. This article mainly reviews the aptamers related to renal cancer, and summarizes and discusses the application of aptamers in the diagnosis and treatment of renal carcinoma.
Traditional tumor treatment methods lack sufficient targeting and can cause serious side effects. Exosomes are natural nanovesicles that carries a variety of biomolecules such as nucleic acids, proteins, metabolites, etc. They participate in intercellular communication and serve as drug delivery carriers with exceptional performance advantages, including low immunogenicity, low toxicity, and the ability to traverse natural barriers. However, targeting ability of exosome-based drug delivery systems is still insufficient. Aptamer is a class of chemically synthesized single-stranded nucleic acid molecules, which have the characteristics of small molecular mass, easy modification and low immunogenicity, and can be used as affinity ligands to specifically bind to targeted molecules. Aptamer-modified exosomes can precisely deliver drugs to the site where tumor cells occur, thereby achieving targeted treatment of tumors, enhancing the effectiveness of tumor therapy, and reducing adverse effects. Aptamers can modify exosomes in a variety of ways, mainly including receptor-ligand binding, hydrophobic interactions, DSPE-PEG2000-Mal conjugation, amide bonding, click chemistry, which lays a solid foundation for the development and application of aptamer functionalized exosome drug delivery systems. At present, the aptamer functionalized exosome drug delivery system still faces the following problems, such as the difficulty of aptamer screening, the low efficiency of exosome isolation and purification, and the lack of safety research on the use of aptamer-functionalized exosomes as drug-targeting delivery systems. As long as the above problems are solved, the role of aptamer functionalized exosomes in the treatment of tumors can be maximized. This review will focus on the application of aptamer functionalized exosome drug targeting delivery systems in various tumor treatments, and elaborate on their future challenges and opportunities.
Extracellular vesicles (EVs) play an important role in many physiological and pathological processes by participating in intercellular communication. Therefore, the isolation and analysis of EVs have a great value for understanding their biological functions and developing EV-based diagnosis and treatment methods for diseases. The efficient isolation and highly sensitive and reliable detection of EVs largely depend on the recognition ligands. Aptamers are a type of single stranded oligonucleotides that can efficiently and specifically bind to their targets. Their merits of easy modification and programmability make them ideal recognition ligands for EV isolation and analysis. To improve the isolation efficiency of EVs, various strategies have been proposed to enhance the affinity of aptamers and the contact probability between interfaces and EVs. In addition, the isolation of EV subtypes helps to understand the biological significance of EVs. In terms of EV analysis, methods such as electrochemistry, visualization, surface enhanced Raman spectroscopy (SERS) and fluorescence were developed, according to the transduction modes of the recognition signals of aptamers and EVs. This review summarizes recent progress, challenges, and future directions in the selection of aptamers and their applications in EV isolation and analysis.
Point-of-care testing (POCT) is an innovative diagnostic technology that provides cost-effective and rapid analysis, as well as accurate diagnostics. It enables patients to obtain clinically relevant results through self-testing. This technology has played a vital role in clinical diagnosis, disease monitoring, and early detection of infectious diseases. Nucleic acid aptamers, which are molecular probes capable of specifically recognizing multiple targets, have emerged as valuable components in biomedical sensors for molecular recognition. They offer advantages such as easy synthesis, good stability, and signal amplification. In recent years, research on aptamer-based POCT technology has garnered widespread attention in the world. The key issues in current research include obtaining more high-affinity aptamers to meet the detection needs of various targets, improving detection sensitivity through signal amplification, and integrating with different sensors to meet the requirements of POCT products. In this review, we first briefly introduce the selection process and the targets used for systematic evolution of ligands by exponential enrichment (SELEX). We discuss new SELEX strategies that have been developed to improve the selection efficiency and enhance the affinity of aptamers. Furthermore, we analyze 4 commonly used signal amplification strategies in aptamer-based POCT sensors. Among these methods, nucleic acid signal amplification and self-assembly signal amplification techniques are commonly used due to their low cost and wide applicability. The combination of these two techniques has also been developed to improve detection sensitivity and shorten reaction time. Coupling aptamers with enzyme-based reactions is the simplest method to improve signal amplification in POCT sensors. Various nanomaterials, such as metal nanoparticles, graphene, carbon nanotubes, and metal-organic frameworks, are widely used to improve the detection sensitivity. The combination of multi-functional nanomaterials for signal amplification has also been introduced in this part. Additionally, we introduce a strategy that involves the use of aptamers to initiate the activation of CRISPR-associated proteins, resulting in the cleavage of DNA or RNA molecular beacons and leading to signal amplification. Furthermore, we also introduce the most recent advances in the development of various aptamer-based electrochemical sensors and optical sensors in the field of POCT. Aptamer-based electrochemical sensors offer advantages such as fast response, easy operation, and portability. In this part, we highlight a series of blood glucose meter based aptasensors used to quantify a variety of biomarkers. For the importance of research on continuous detection device, we review recent progress in the development of aptamer-based continues electrochemical testing devices. In aptamer-based optical POCT techniques, the recent development of colorimetry, lateral flow assay (LFA), fluorescence, surface-enhanced Raman scattering (SERS), surface plasmon resonance (SPR), and evanescent wave fiber optic sensors are introduced, with a focus on comparing the performance characteristics of each sensor. Finally, this review presents a summary and future challenges in the research and commercialization of aptamer-based POCT sensors. To simplify the aptamers selection process, it is crucial to invest in studying the molecular recognition mechanisms of aptamers and developing artificial intelligence-based methods for aptamer selection. Additionally, integrating aptamers with advanced sensor technologies like microfluidic chips and wearable devices can greatly enhance detection sensitivity and stability. From a commercial perspective, current aptamer-based POCT products mostly comprise fluorescent or colorimetric assay kits and lateral flow test strips. However, to garner more attention in the competitive POCT market, aptamer-based POCT sensors have an edge in small molecules detection and multi-channel detection.
Abnormal glycosylation of tumor cells is a sign of cancer, and it plays a vital role in malignant transformation and cancer progression. Tumor-associated carbohydrate antigens (TACAs) caused by different mechanisms have been suggested as biomarkers for clinical oncology diagnosis, as well as specific targets for therapeutic interventions. For both aspects, the development of TACA-specific binders with high affinity and specificity is of essential significance. Lectins and antibodies are the major biological tools for the recognition of specific glycans. However, due to the complex structural homology and low immunogenicity of glycans, the recognition capability of lectins and preparation of sugar-specific antibodies are facing distinct challenges. Aptamers, which are short single-stranded DNA/RNA oligonucleotides capable of recognizing a range of chemical and biological species, seem to be a potential solution. They exhibit several significant advantages, such as smaller size, better stability, easier synthesis, facile modification, lower toxicity, and immunogenicity, for in vivo utilization. In recent years, aptamers have attracted increasing attention in the recognition of carbohydrates, but review literatures on aptamers targeting glycans are lag behind. This review focuses on the current development of TACA-binding aptamers. Firstly, we present a brief overview of the role of glycosylation changes in cancer growth, and cite some frequent TACAs as recognized hallmark traits. Secondly, we discuss the major challenges that hinder the exploration of glycan recognition receptors, and compare the strengths and weaknesses of lectins and antibodies. Thirdly, we underline the unique advantages of aptamers, and summarize the available or improved TACA-binding aptamers. According to the target sources in the aptamer screening procedure, 3 kinds of targets including purified carbohydrate molecules, glycan epitope of proteins, and serum carbohydrate antigens are described. We highlight specific examples to emphasize the progress in terms of screening methods, aptamer performance and applicabilities. Finally, we conclude the main contents, and provide the suggestions and directions for developing more valuable, effective, and high-performance TACA-targeted aptamers in the future. In contrast with lectins and antibodies, aptamers are still a newly emerging force, and the aptamer-based scientific research and translational applications have experienced rapid expansion recently. It is worth noting that only a few aptamers with sufficient affinity, specificity, and stability could be used for practical applications, and the number of aptamers available for glycan recognition is even more limited. Until now, most aptamers against glycoprotein biomarkers have been obtained without directing the selection towards any specific region of the target. Consequently, in most cases it is not known whether glycan, peptide or both are involved in the binding. It has still remained a great challenge to screen glycan-specific aptamers, and more efforts are needed to elevate the application of aptamers in cancer diagnosis and treatment to a new level. With the continuous advancement of aptamer screening technology, we believe that more new types of TACA aptamers will be generated, and their specificities will be further improved. Therefore, nucleic acid aptamers hold great prospect and strong market in the future clinical practice, and the detection of glycoforms of current biomarkers is a promising approach to improve sensitivity and specificity in early cancer diagnosis.
Acute myocardial infarction (AMI) has become the leading cause of death in cardiovascular diseases. Myocardial ischemia-reperfusion (MI/R) occurs when myocardial blood circulation is reconstructed after blood supply is limited or lack, often after myocardial infarction, and is the main cause of acute myocardial injury. According to the length of ischemia time, arrhythmia, myocardial inhibition, and myocardial infarction may occur in sequence in MI/R. Mitochondria are the key organelles involved in MI/R injury. Mitochondrial ROS eruption, Ca2+ imbalance, mPTP opening, mitochondrial swelling, and release of pro-apoptotic proteins all lead to mitochondrial dysfunction and myocardial function impairment. Exercise is an effective intervention to prevent myocardial ischemia-reperfusion injury, and its protective effect is closely related to the intensity of exercise, the length of exercise time, the type of exercise and the internal exercise ability. The mitochondrial mechanism of exercise protection against myocardial ischemia-reperfusion injury is determined by many factors, such as mitochondrial energetics, KATP channels, mPTP, ΔΨm, mitochondrial proteins, mitochondrial lipids, mitochondrial quality control, and some remote regulatory factors. This paper reviews the mitochondrial mechanism of MI/R, the protective effect of exercise on MI/R and the role of mitochondria in it, in order to provide more theoretical basis and new therapeutic targets for the diagnosis and treatment of heart disease, and provide new targets for drug research and development. In future clinical treatment, it is expected that sports pills targeted mitochondria can treat MI/R injury for bedridden people who cannot exercise or people who do not want to exercise through new technological means such as nanoparticle packaging.
Endo-beta-N-acetylglucosaminidase (ENGase) is widely distributed in various organisms. The first reported ENGase activity was detected in Diplococcus pneumoniae in 1971. The protein (Endo D) was purified and its peptide sequence was determined in 1974. Three ENGases (Endo F1-F3) were discovered in Flavobacterium meningosepticum from 1982 to 1993. After that, the activity was detected from different species of bacteria, yeast, fungal, plant, mice, human and etc. Multiple ENGases were detected in some species, such as Arabidopsis thaliana and Trichoderma atroviride. The first preliminary crystallographic analysis of ENGase was conducted in 1994. But to date, only a few ENGases structures have been obtained, and the structure of human ENGase is still missing. The currently identified ENGases were distributed in the GH18 or GH85 families in Carbohydrate Active Enzyme (CAZY) database. GH18 ENGase only has hydrolytic activity, but GH85 ENGase has both hydrolytic and transglycosylation activity. Although ENGases of the two families have similar (β/α)8-TIM barrel structures, the active sites are slightly different. ENGase is an effective tool for glycan detection and glycan editing. Biochemically, ENGase can specifically hydrolyze β-1,4 glycosidic bond between the two N-acetylglucosamines (GlcNAc) on core pentasaccharide presented on glycopeptides and/or glycoproteins. Different ENGases may have different substrate specificity. The hydrolysis products are oligosaccharide chains and a GlcNAc or glycopeptides or glycoproteins with a GlcNAc. Conditionally, it can use the two products to produce a new glycopeptides or glycoprotein. Although ENGase is a common presentation in cell, its biological function remains unclear. Accumulated evidences demonstrated that ENGase is a none essential gene for living and a key regulator for differentiation. No ENGase gene was detected in the genomes of Saccharomyces cerevisiae and three other yeast species. Its expression was extremely low in lung. As glycoproteins are not produced by prokaryotic cells, a role for nutrition and/or microbial-host interaction was predicted for bacterium produced enzymes. In the embryonic lethality phenotype of the Ngly1-deficient mice can be partially rescued by Engase knockout, suggesting down regulation of Engase might be a solution for stress induced adaptation. Potential impacts of ENGase regulation on health and disease were presented. Rabeprazole, a drug used for stomach pain as a proton inhibitor, was identified as an inhibitor for ENGase. ENGases have been applied in vitro to produce antibodies with a designated glycan. The two step reactions were achieved by a pair of ENGase dominated for hydrolysis of substrate glycoprotein and synthesis of new glycoprotein with a free glycan of designed structure, respectively. In addition, ENGase was also been used in cell surface glycan editing. New application scenarios and new detection methods for glycobiological engineering are quickly opened up by the two functions of ENGase, especially in antibody remodeling and antibody drug conjugates. The discovery, distribution, structure property, enzymatic characteristics and recent researches in topical model organisms of ENGase were reviewed in this paper. Possible biological functions and mechanisms of ENGase, including differentiation, digestion of glycoproteins for nutrition and stress responding were hypothesised. In addition, the role of ENGase in glycan editing and synthetic biology was discussed. We hope this paper may provide insights for ENGase research and lay a solid foundation for applied and translational glycomics.
Extracellular vesicles (EVs) are a kind of exsomes secreted by cells, which all cells release them as part of their normal physiology and during acquired abnormalities. Extracellular vesicles (EVs) can be broadly divided into two categories by their sizes, and medium/large EVs (m/l EVs). As a kind of extracellular vesicle, small EVs (sEVs) are mostly discoid vesicles with diameters ranging from 40?nm to 200?nm, less than 200nm. The medium/large EVs (m/l EVs) are elliptical with a diameter more than 200nm. sEVs play a crucial role in intercellular communication and have emerged as important mediators in the development and progression of liver diseases.
In this review, we discussed the current understanding of the role of sEVs, particularly non-coding RNA in non-alcoholic fatty liver disease (NAFLD) and their potential as diagnostic and therapeutic targets. sEVs are small membrane-bound particles secreted by cells, which fuse with plasma membrane and release to extracellular matrix. Depending on the cell of origin, sEVs ccould contain many cell constituents, including various DNA, RNA, lipids, metabolites, and cytosolic and cell-surface proteins, biomolecules. In addition, many RNA and DNA molecules contained by sEVs, such as mRNA, microRNA (miRNA), long noncoding RNA (lncRNA) and mitochondrial DNA (mtDNA), which can be transferred to recipient cells to effectively promote their biological response, physiological and pathological functions. Such sEVs-mediated responses can be disease promoting or restraining. The intrinsic properties of sEVs in regulating complex intracellular pathways has advanced their potential utility in the therapeutic control of many diseases. Recent studies reviewed here also indicate a functional, targeted, mechanism-driven accumulation of specific cellular components in sEVs, suggesting that they have a role in regulating intercellular communication. Many studies have also shown the involvement of sEVs’ noncoding RNA in controlling cell activities and their crucial functions in regulating lipid metabolism. sEVs noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs) regulate physiological functions and maintain lipid metabolism homeostasis. MicroRNAs (miRNA) are small non-coding RNA molecules that regulate posttranscriptional gene expression by repressing messenger RNA-targets. These circulating miRNAs are easily accessible, disease-specific and sensitive to small changes, which makes them ideal biomarkers for diagnostic, prognostic, predictive or monitoring purposes. Specific miRNA signatures can be reflective of disease status and development or indicators of poor treatment response in liver diseases. And lncRNAs have been shown to regulate gene expression by interacting with transcription factors or chromatin-modifying enzymes, which regulate gene expression by binding to target mRNAs. Then circRNAs contributed to NAFLD progression by acting as microRNA sponges, functional protein sponges, or novel templates for protein translation.
Finally, sEVs could be engineered to deliver diverse therapeutic payloads, including short interfering RNAs, antisense oligonucleotides and so on, with an ability to direct their delivery to a desired target. The potential of targeting sEVs with lncRNAs and microRNAs not only could be potential diagnostic biomarkers for NAFLD, but also have potential therapeutic effects on NAFLD, which might provide new ideas for the NAFLD treatment. In conclusion, this review article provides an overview of the current understanding of the roles of sEVs nonconding RNA in NAFLD, so we suggest that further research into these molecules could lead to new diagnostic tools and therapeutic strategies for NAFLD.
LI Xiang,LI Ye.The roles of small extracellular vesicles and the non-coding RNA they carry in non-alcoholic fatty liver disease[J]..Export: BibTexEndNote
Cerebral ischemic stroke is an acute cerebrovascular disease caused by cerebral vascular occlusion, and it is associated with high incidence, disability, and mortality rates. Studies have found that excessive or insufficient autophagy can lead to cellular damage. Autophagy consists of autophagosome formation and maturation, autophagosome-lysosome fusion, degradation and clearance of autophagic substrates within autolysosomes, and these processes collectively constitute autophagic flux. Research has revealed that cerebral ischemia can induce impaired fusion between autophagosomes and lysosomes, resulting in autophagic flux impairment. Intracellular membrane fusion is mediated by three core components: N-ethylmaleimide sensitive factor (NSF) ATPase, soluble NSF attachment protein (SNAP), and soluble NSF attachment protein receptors (SNAREs). SNAREs, after mediating fusion between autophagosomes and lysosomes, remain in an inactive complex state on the autolysosomal membrane, requiring NSF reactivation into monomers to perform subsequent rounds of membrane fusion-mediated functions. NSF is the sole ATPase capable of reactivating SNAREs. Recent studies have shown that cerebral ischemia significantly inhibits NSF ATPase activity, reducing its reactivation of SNAREs. This may be a pathological mechanism for impaired fusion between autophagosomes and lysosomes, leading to neuronal autophagic flux impairment. This article discusses the pathological mechanisms of NSF ATPase inactivation, including SNAREs dysregulation, impaired fusion between autophagosomes and lysosomes, and insufficient transport of proteolytic enzymes to lysosomes, and explores approaches to improve neuronal autophagic flux through NSF ATPase reactivation. It provides references for stroke treatment improvement and points out directions for further research.
Objective Molecular docking plays a critical role in predicting binding modes and affinity between molecules, serving as a pivotal method in structural biology and computer-aided drug design research. Our research team has recently developed a novel template-based docking method called FitDock, which outperforms commonly used molecular docking methods in terms of accuracy and speed, particularly when approximate protein-ligand templates are available. To enhance the accessibility of the FitDock method and promote its broader application in the field of molecular simulation, the development of a graphical software tool is imperative. Methods Utilizing Python-based graphical programming, we have created FitDockApp, a plugin software for the molecular visualization software PyMOL. Results FitDockApp enables template-based molecular docking and ligand structure alignment through an interactive graphical interface, providing real-time visualization of predicted three-dimensional structures. It also offers the convenience of uploading docking files to a laboratory server to obtain the optimal template. Additionally, FitDockApp includes batch docking functionality. Conclusion FitDockApp simplifies the docking process through its user-friendly interface and provides robust functionality to assist researchers in obtaining precise docking results. FitDockApp is a free software compatible with both Windows and Linux systems and can be downloaded from http://cao.labshare.cn/fitdock/.
In vertebrate embryonic development, the segmentation clock controls the cyclic formation of somites through presomitic mesoderm (PSM) cells. Somites are paired segmented structures along the anterior–posterior axis that eventually develop into vertebrae and ribs. Disruptions in the segmentation clock leads to defects in somitogenesis, resulting in congenital spinal diseases. The major patterning modules that are involved in segmentation clock is the clock and wavefront, which primarily relies on signaling gradients and cyclic oscillation. Mesodermal differentiation is regulated by combinatorial gradient system that involves the activity of the fibroblast growth factor (FGF), the Wnt/ b-catenin, and the retinoic acid (RA) signaling pathways. The antagonistic gradients of these signals set a position of the determination front. In the tail bud and posterior mesoderm, FGF and Wnt signaling prevent cell maturation and the molecular oscillators start to express. The molecular oscillators rely on negative feedback loops to maintain their oscillatory expression patterns. As the cells move anteriorly, FGF signaling gradually decays and RA signaling began to strengthen. Meanwhile, the molecular oscillators propagate anteriorly with wave pattern. At the determination front, low levels of FGF signaling and high levels of RA signaling eliminate differentiation inhibition and initiate molecular oscillators to activate cyclic genes, such as Mesp2, leading to the formation of repetitive structures in somites. Advancements in live reporter and 2D culture systems have revealed that coupling delays in cell communication can maintain the synchronous segmentation clock between adjacent cells. Studies have shown that these coupling delays are controlled by the Lfng gene, it can adjust coupling delays to fit in-phase oscillations by increasing the time required for intercellular DLL1–Notch signaling. To sum up, the dual homeostasis of opposing signaling gradients determines the segment boundaries, the distance traveled by a molecular oscillator in one oscillation cycle determines the somite size, and the delayed coupling in intercellular signaling regulates the synchronization of clock oscillations. These three factors interact with each other to form a segmentation clock network coordinating somitogenesis. Recent studies have revealed that the intercellular coupling delay mechanism is a major factor influencing the maintenance of oscillation synchronization. Intercellular coupling delay errors, such as increased or decreased delay time, can desynchronizing intercellular oscillations and resulting in somite fusion. However, the mechanisms governing how intercellular communication becomes involved in oscillation synchronization remains unclear. Congenital scoliosis (CS) is a result of anomalous development of the vertebrate which associate with somitogenesis malformation. We observed that deficiency or overdose of vitamin A intake in gestation may lead to CS. While the deep mechanism of how RA signalling regulates oscillation synchronization still need to be detected. With the rapid development of 3D culture systems, researchers have successfully recapitulated the formation of somite-like structures with antero-posterior identity and indicated that the rate of metabolism is directly proportional to that of development. In summary, deconstructing the segmentation clock in vitro facilitates the dissection of regulation networks of the segmentation clock and offers an excellent proxy for studying the metabolic regulation of somitogenesis speed across species and the mechanisms underlying the formation of bilateral symmetry. It also creates a platform for exploring dysregulation mechanisms involved in the development of pathological somite defects.
Human-animal interaction has a long-standing tradition dating back to ancient times. With the rapid advancements in intelligent chips, wearable devices, and machine algorithms, the intelligent interaction between animals and electronic technology, facilitated by electronic devices and systems for communication, perception, and control, has become a reality. These electronic devices aim to implement an animal-centric working mode to enhance human understanding of animals and promote the development of animal intelligence and creativity. This article takes medium-sized and large animals as research objects, with the goal of developing their ability enhancement, and introduces the concept of "Intelligent Animal Augmentation System (IAAS)". This concept is used to describe the characteristics of such devices and provides a comprehensive overview of existing animal and computer interface solutions. In general, IAAS can be divided into implantable and non-implantable types, each composed of interface platforms, perception and interpretation, control and instruction components. Through various levels of enhancement systems and architectural patterns, intelligent interaction between humans and animals can be realized. Although existing IAAS still lack a complete independent interaction system architecture, they hold great promise and development space in the future. Not only can they be applied as substitutes for cutting-edge devices and transportation equipment, but they are also expected to achieve cross-species information interaction through intelligent interconnection. Additionally, IAAS can promote bidirectional interaction between humans and animals, playing a significant role in advancing animal ethics and ecological protection. Furthermore, the development of interaction models based on animal subjects can provide insightful research experiences for the design of human-computer interaction systems, thereby contributing to the more efficient realization of the ambitious goal of human-machine integration.
Food addiction is an important factor in the development of human obesity and is also a core factor that most people cannot maintain weight loss or adhere to restrictive diets to maintain a healthy weight. A deeper understanding of food addiction and its neurobiological mechanisms will provide accurate targets for intervening in food addiction to improve obesity. Food addiction refers to the dependence of individuals on certain specific foods (high-calorie foods) to the extent that it becomes difficult to control and manifests a series of addictive-like behavioral changes. Drug addiction is characterized by compulsive, chronic and repetitive nature. Yale Food Addiction Scale (YFAS) has been developed to specifically assess food addiction. The animal model for food addiction is the mouse food self-administration model. The neural circuits of the lateral hypothalamus-ventral tegmental area-nucleus accumbens and ventral tegmental area-prelimbic-nucleus accumbens are key neurobiological mechanisms that regulate food addiction.
When skin injuries are healing, complex wound environments can be easily created, which can result in wound infection, excessive inflammation caused by neutrophil accumulation and inflammatory factors, and excessive reactive oxygen species, resulting in high levels of oxidative stress. As a result of these factors, cell membranes, proteins, DNA, etc. may become damaged, which adversely affects the repair function of normal cells around the wound, resulting in the formation of chronic wounds. The effectiveness of wound dressings as a treatment is well known. They can offer temporary skin damage protection, prevent or control wound infection, create an environment that is conducive to mending skin damage, and speed wound healing. Traditional dressings like gauze, cotton balls, and bandages, however, have the drawbacks of having no antimicrobial properties, having weak adhesive properties, having poor mechanical properties, being susceptible to inflammation, obstructing angiogenesis, needing frequent replacement, and being unable to create an environment that is conducive to wound healing. As an innovative bandage, self-assembled hydrogel has great water absorption, high water retention, superior biocompatibility, biodegradability and three-dimensional structure. With properties including hemostasis, antibacterial, anti-inflammatory, and antioxidant, the synthesized raw material itself and the loaded active compounds have a wide range of potential applications in the treatment of skin injuries and wound healing. This research begins by examining and discussing the mechanism of cross-linking in self-assembled hydrogels. The cross-linking modes include non-covalent consisting of physical interaction forces such as electrostatic interactions, ∏-stacking, van der Waals forces, hydrophobic interactions, and metal-ligand bonds, covalent cross-linking formed by dynamic covalent bonding such as disulfide bonding, Schiff bases, etc. And hybrid cross-linking with mixed physical forces and dynamic covalent bonding. The next part describes the special structure and excellent functions of self-assembled hydrogels, which include an extracellular matrix-like structure, the removal of exogenous microorganisms, and the mitigation of inflammation and oxidative stress. It goes on to explain the benefits of using self-assembled hydrogels as dressings for skin injuries. These dressings are capable of controlling cell proliferation, loading active ingredients, achieving hemostasis and coagulation, hastening wound healing, and controlling the regeneration of the injured area. The development of self-assembly hydrogels as dressings is summarized in the last section. The transition from purely non-covalent or covalent cross-linking to hybrid cross-linking with multiple networks, from one-strategy action to multi-strategy synergy in exerting antimicrobial, anti-inflammatory, and antioxidant effects and from single-function to multi-functioning in a single product. Additionally, it is predicted that future developments in self-assembled hydrogels will focus on creating biomimetic gels with multi-strategy associations linkage from naturally self-assembling biomolecules peptides, lipids, proteins and polysaccharides; improving the properties and cross-linking of raw materials to enhance the storage capabilities of hydrogels and cross-linking techniques, realizing the recycling of hydrogels; conducting additional research and exploration into the cross-linking process of hydrogels; and realizing the gel's controllable rate of degradation. Furthermore, combining three-dimensional (3D) printing and 3D microscopic imaging technology to design and build one-to-one specialized gel dressings; using computer simulation and virtual reality to eliminate the time factor, resulting in self-assembled hydrogels that perfectly fit the ideal dressing.
Objective Disruption of epithelial layer may instantaneously induce the generation of endogenous electric fields, which was proved to play an important role in guiding the cell migration and promoting wound healing. PIEZO1 is a kind of mechanic sensitive channel, may regulate by voltage, is proved to involve in chemotactic migration of cells and play an important role in the process of wound healing. In this paper, the role of PIEZO1 and its downstream proteins FAK and Integrin β1 in the electric field guided cell migration were investigated by HaCaT cells (human immortalized keratinocyte). Method Cell migration was tracked by Living cell Imaging System in directed current (DC) electric field (EF). Inhibitors and RNAi techniques were applied to study the function of PIEZO1 and other related proteins in electric fields. Western blot was used to detect the expression and phosphorylation levels of Integrin β1 and FAK in electric field guided migration under EF stimulation. Results PIEZO1 RNAi as well as Ruthenium red and GsMTx4 treatment all significantly inhibited the electrotaxis of HaCaT cells. Electric field stimulation with GsMTx4 treatment alone increased FAK phosphorylation level and the expression of Integrin β1. Electric field promoted the expression level of Integrin β1 and the phosphorylation level of FAK. Inhibiting the expression of PIEZO1 by RNAi significantly attenuated the phosphorylation level of FAK under EF stimulation. Inhibition of Integrin β1 and FAK by inhibitor significantly decrease the electric field guided cell migration. Conclusion PIEZO1 as well as Integrin β1 and FAK are involved in the electric field guided cell migration of HaCaT cells. Electric field signals regulate the expression of Integrin β1 and the activation of FAK through PIEZO1-mediated signal pathway to orchestrate cell migration.
Abstract The CRISPR/Cas system consists of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR-associated proteins (Cas). The system forms an adaptive immune system in archaea and bacteria. The inherent defense mechanism enables these microorganisms to protect themselves against the invasion of foreign genetic material. The system functions of immune response including three main stages: adaptation, expression/maturation, and interference, each stage needs specific Cas proteins encoded by Cas gene located near the CRISPR sequences, along with other auxiliary proteins. In 2015, Zhang et al. reported the Cas12a (Cpf1) as a member of the Class II type V CRISPR/Cas12a system, which possesses endonuclease activity. This finding holds great promise for its application in the field of biotechnology. In 2018, Doudna’s team first applied the CRISPR/Cas12a system for detecting HPV nucleic acid. The system comprises the following essential components in vitro detection:
Cas12a, the crRNA sequence complementary to the target DNA, the PAM sequence, and the ssDNA reporter.
Cas12a possesses a typical RuvC domain, displaying a canonical bilobed architecture that consists of a recognition (REC) lobe and a nuclease (NUC) lobe. The REC lobe contains the REC1 and REC2 domains, and the NUC lobe includes RuvC, PAM-interacting (PI), Wedge (WED), and Bridge helix (BH) domains. The mature crRNA for Cas12a has a length of 42-44 nt, consists of repeat sequence (19/20 nt) and spacer sequence (23-25 nt). The crRNA spacer sequence has been found to require a length of 18 nt to achieve complete cleavage activity in vitro. Additionally, mutation in the bases of crRNA can indeed affect the activity of Cas12a.
The PAM sequence plays a critical role in the recognition and degradation of DNA by the CRISPR/Cas system, enabling the system to distinguish between self and non-self genomic materials. Cas12a can effectively target the spacer sequence downstream of a T-rich PAM sequence at the 5' end. LbCas12a and AsCas12a both recognize the PAM sequences of 5'-TTTN-3', while FnCas12a recognizes the PAM sequences of 5'-TTN-3'. All of these PAM sequences are located upstream on the non-template strand (NTS) at the 5' end.
Cas12a (Cpf1), guided by the crRNA, binds to the target DNA by recognizing the PAM sequence. It exhibits the ability to induce arbitrary cleavage of ssDNA within the system while cleaving the target ssDNA or dsDNA. According to this feature, an array of nucleic acid detection methods has been developed for tumor detection and infection diagnostics, such as the DETECTR (RPA-CRISPR/Cas12a method) and HOLMES (PCR-CRISPR/Cas12a method) in 2018. Then, in 2019, Cas12aVDet (one-step detection method), where Cas12a protein was immobilized on the upper wall of the reaction tube. This not only prevented contamination from opening the tube but also reduced the detection reaction time. In 2021, the dWS-CRISPR (digital warm-start CRISPR) was developed as a one-pot detection method. It serves as an accurate approach for quantitatively detecting SARS-CoV-2 in clinical specimens. With the innovation of scientific technology, the high-sensitivity signal transduction technology has also been integrated with the CRISPR/Cas12a system, enabling direct detection of nucleic acids, and eliminating the need for nucleic acid amplification steps.
Here, we elaborated the detection principles of CRISPR/Cas12a in in vitro detection. We discussed the different stages leading to the catalytic pathway of target DNA, and the practical applications of Cas12a in nucleic acid detection. These findings revealed a target interference mechanism that originates from the binding of Cas12a-guided RNA complex to complementary DNA sequences within PAM-dependent (dsDNA) regions. The crRNA-DNA binding activates Cas12a, enabling site-specific dsDNA cleavage and non-specific ssDNA trans-cleavage. The release of Cas12a ssDNase activity provides a novel approach to enhance the sensitivity and specificity of molecular diagnostic applications. Before these CRISPR/Cas12a-based nucleic acid detection methods can be introduced into clinical use, substantial work is still required to ensure the accuracy of diagnosis. Nevertheless, we believe that these innovative detection tools based on CRISPR/Cas will revolutionize future diagnostic technologies, particularly offering significant assistance in pathogen infection diagnosis for developing countries with relatively poor healthcare conditions and high prevalence of infectious diseases.
Objective The warm sensors located in keratinocytes have the ability to directly detect warm temperature, with TRPA1 in dorsal root ganglion (DRG) neurons being a potential mediator of the downstream transduction process. The present study aimed to elucidate the mechanism by which warm information is transmitted from keratinocytes to TRPA1. Method TRPA1-transfected HKE293T cells as well as DRG neuron cells from wild-type and TRPA1 knockout mice were cultured separately, and stimulated with warm temperatures using a perfusion apparatus. Single cell calcium imaging was used to monitor calcium influx during stimulation, and the role of H2O2 in this process was also examined. Additionally, RNA-seq analysis was performed on primary keratinocytes cultured at different temperatures to identify potential candidates responsible for keratinocytes-TRPA1 warm transduction. Results Our finding indicated that TRPA1-transfected HEK293T cells or DRG neurons could be activated by warm temperature in the presence of H2O2. However, when TRPA1 was knocked out or blocked by HC-030031, the H2O2-potentiated warm response was significantly reduced. Moreover, Chemokine C–C motif ligand 2 (CCL2) and decorin (DCN), two H2O2 related factors, exhibited different expression patterns in keratinocytes cultured at 33℃ and 37℃, respectively. This result is consistent with previous research showing that mice stimulated at 37℃ induced more DRG activation than those stimulated at 33℃. Conclusion H2O2 can potentiate the TRPA1-dependent warm response, and H2O2-related factors in keratinocytes can be affected by warm temperature, suggesting the possible role of H2O2 related factors in warm transduction from keratinocytes to downstream TRPA1 in DRG neurons.
Pupil size, as a window into the minds of others, plays a crucial role in social interaction. While previous studies have focused on the influence of non-social factors, such as the physical properties of stimuli, on pupil diameter, recent research has emphasized the significant connection between social information processing and pupil size. In this comprehensive review, we aim to explore how the processing of social stimuli (e.g., face, biological motion) and their emotional characteristics affect pupil size. In essence, pupil size is believed to reflect an individual's perception of social stimuli. It goes beyond simple physical properties and encompasses the processing of complex social information, including social contexts and interactions. The modulation of pupil size in response to social stimuli is believed to be driven by two key mechanisms: emotional arousal and social attention. When individuals encounter emotionally charged social cues, their pupils tend to dilate, indicating heightened emotional engagement. Similarly, the dilation of pupils when individuals focus on specific social cues suggests an increased allocation of cognitive resources to process relevant social information. Furthermore, the connection between pupil size and social information processing has provided intriguing findings in individuals with autism spectrum disorder (ASD). Known for their significant social deficits, individuals with ASD exhibited abnormal pupillary responses when presented with social stimuli. These findings raise the possibility of utilizing pupillary responses as a potential index for identifying individuals with ASD at a relatively younger age. Moreover, the incorporation of pupillary response measurements in the diagnosis holds great promise in transcending the limitations of the minimum diagnostic age. This can have important implications both in terms of theoretical understanding and practical applications related to the diagnosis and intervention of ASD.
Objective At present, the matching reagents of commercially available Rapid DNA instruments based on microfluidics chip technology are autosome STR individual identification reagents. The non-recombining part of the human Y chromosome is widely used in forensic DNA analysis, particularly in cases where standard autosomal DNA profile is uninformative. Y-STR loci are useful markers to identify males and male lineages in forensic practice. In order to achieve rapid and fully integrated detection of Y-STR loci, this study constructed the RTyper Y27 microfluidic chip rapid detection system and validated the performance of this system. Methods The system was verified and evaluated by sensitivity, success rate, typing accuracy, peak height balance, sizing precision and accuracy, mock case sample tests, mixture detection ability, and inhibition tolerance. Results Complete Y-STR profiles can be obtained when the template amount of DNA standard 9948 was ≥8 ng, the number of blood cards was ≥3 pieces, and the number of oral swab scrapings was ≥7 times. The success rate of fully integrated detection was 91.52%, and the concordance rates was 99.74% for 165 testing samples. The success rate of 115 blood spots in these samples was 90.43%, with a typing accuracy of 99.65%, the success rate of 50 buccal swabs was 94%, with a typing accuracy of 99.92%. There was no significant difference in typing accuracy between blood spots and buccal swab samples. The peak height ratio between different fluorescence channels was 89.81%. The standard deviation of allelic ladder for 10 runs was within 0.5 bp. The size differences between allele and corresponding allele in allelic ladder was within 0.5 bp. The maximum precision CV values within and between batches were 0.48% and 0.68%, respectively, which were lower than 15%. These data indicate that the system has good accuracy and precision. The system was capable of accurately typing oral swabs, blood cards, saliva cards, cigarette butts, blood swabs and seminal stains. Complete Y-STR profiles can be obtained and distinguish at the 1:3 ratio of minor and major contributors in artificial male DNA mixtures. Complete Y-STR genotyping can be obtained under the interference of inhibitors, such as different concentrations of humic acid (50 ng/μL~400 ng/μL), indigotin (20 nM~100 nM) and hemoglobin (100 μM~500 μM). Conclusion In this study, the RTyper Y27 microfluidic chip rapid amplification system is combined with the Quick TargSeq 1.0 integrated system, and the Y-STR profile can be obtained in approximately 2 hours. Through a series of verification experiments, the results show that the system has good repeatability, accuracy and stability, can meet the on-site Y-STR detection requirements, and can be used in forensic practice.
Glycosylation is one of the most important reactions in living organisms as it results in the formation of glycoconjugates with diverse biological functions. Sugar nucleotides are structurally composed of sugar and nucleoside diphosphate or monophosphate, which are widespread within a variety of biological cells. As glycosyl donors for the transglycosyl reactions catalyzed by Leloir-type glycosyltransferases, sugar nucleotides are essential for the synthesis of glycans and glycoconjugates. However, high costs and limited availability of nucleotide sugars prevent applications of biocatalytic cascades on an industrial scale. Therefore, attentions on synthetic strategies of sugar nucleotides have been increasing to achieve their wide applications in various fields.
The nine common sugar nucleotides in mammals have been fully studied with large-scale synthesis through chemical, enzymatic (chemo-enzymatic) and cell factory strategies. In addition to common sugar nucleotides, many rare sugar nucleotides are present in plants and bacteria. Although unnatural sugar nucleotides cannot be synthesized in organisms, they have great potential in research as substrates for glycosyltransferases in carbohydrate synthesis, as enzyme inhibitors in biochemical studies, and as components of glycoconjugate biosynthesis. Therefore, increasing attention has been paid to explore the efficient synthesis of unnatural sugar nucleotides. Currently, strategies for chemical synthesis of sugar nucleotides have been greatly improved, such as the use of effective catalysts for forming pyrophosphate bonds and the development of entirely new synthesis protocols. Multiple sugar nucleotides, especially unnatural sugar nucleotides, are synthesized chemically. However, chemical synthesis requires tedious protection and deprotection steps, resulting in complex steps, high cost and low yield. In contrast, enzymatic (chemo-enzymatic) and cell factory method have significant advantages such as high yield, easy operation and easy process scale-up in the preparation of sugar nucleotides. Hence, they are prominent strategies for sugar nucleotide preparation.
Herein, the biosynthesis and application of sugar nucleotides are reviewed, mainly focusing on the nine sugar nucleotides common in mammals. The early strategies for enzymatic synthesis of sugar nucleotides generally used de novo synthesis pathway. With the discoveries of enzymes involved in salvage pathway of sugar nucleotide synthesis and the development of one-pot multienzyme (OPME) method, the synthesis of sugar nucleotides was greatly simplified. Cell factory method employs the microbial living cells as a "processing plant" by engineering their metabolic pathways through genetic engineering technology. The cell factory method has high yield, and has been applied for efficient synthesis of several sugar nucleotides. Moreover, the strategy of gram-scale synthesis of multiple rare sugar nucleotides by cascade reactions from common sugar nucleotides using sugar nucleotides synthases cloned from different sources was illustrated. In recent years, the synthesis cost of sugar nucleotides has been further reduced through various ways, such as regeneration of nucleotides, regeneration of organic cofactors, and application of immobilized enzyme technology. Furthermore, through the continuous improvement of sugar nucleotides purification process, the use of high concentration of multi-enzyme cascade and rapid chromatographic purification process, the synthesis of multiple sugar nucleotides and their derivatives from monosaccharides was achieved, which gradually broke the limitations of the existing strategy. With the efficient synthesis of sugar nucleotides, their applications in various fields have been increasingly explored, including the synthesis of glycans and glycoconjugates, biochemical characterization of glycosyltransferases and bioorthogonal labeling strategies, which are of great significance to the research of biochemistry, glycobiology and the development of related pharmaceutical products.
Lipoprotein(a) (Lp(a)) is a complex circulating lipoprotein, and increasing evidence has demonstrated its role as a risk factor for atherosclerotic cardiovascular disease and as a possible therapeutic target. Proprotein converting enzyme proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor significantly decreases the circulating level of Lp(a) and reduces the risk of cardiovascular events. Based on the research results in recent years, this review will systematically summarize the progress on the relevant mechanisms of PCSK9 inhibitor reducing Lp(a) synthesis and promoting its degradation, as well as the challenges and future directions in this field.
Xue Yu,liyang.Progress on the mechanisms of PCSK9 inhibitor reducing lipoprotein (a)[J]..Export: BibTexEndNote
Methamphetamine (METH) is a powerful stimulant drug that can cause addiction and serious health problems. It is one of the most widely abused drugs in the world, especially in China. However, the mechanisms of how METH affects the brain and leads to addiction are still unclear, and there are no effective treatments for METH addiction in clinical practice. Therefore, it is important to explore the new addiction mechanisms and treatment strategies of METH.
METH addiction is a complex and chronic brain disorder that involves multiple brain regions and neurotransmitter systems. Neurotransmitters are chemical messengers that transmit signals between neurons (nerve cells) in the brain. Some of the main neurotransmitters involved in METH addiction are dopamine (DA), glutamate (Glu), norepinephrine (NE), and serotonin (SNRIS). These neurotransmitters regulate various aspects of brain function, such as reward, reinforcement, motivation, cognition, emotion, and behavior.
When a person takes METH, it causes a surge of these neurotransmitters in the brain, especially in the prefrontal cortex (mPFC), ventral tegmental area (VTA), and nucleus accumbens (NAc). These brain regions form a circuit called the mesocorticolimbic system, which is responsible for mediating the rewarding and reinforcing effects of drugs and natural stimuli. The increased levels of neurotransmitters in this circuit make the person feel euphoric, alert, confident, and energetic. However, repeated or chronic use of METH can also cause negative effects, such as anxiety, paranoia, psychosis, depression, and cognitive impairment.
The effects of METH on the brain are not only due to the changes in neurotransmitter levels, but also to the changes in gene expression. Gene expression is the process by which genes are turned on or off to produce proteins that perform various functions in the cells. Gene expression can be influenced by environmental factors, such as drugs, stress, diet, etc. One way that environmental factors can affect gene expression is through epigenetic mechanisms.
Epigenetics is a branch of genetics that studies the heritable changes in gene expression that are not caused by changes in DNA sequence. Epigenetic mechanisms include histone modifications, DNA methylation, and non-coding RNA regulation. These mechanisms can modulate the chromatin structure and accessibility, thereby affecting the transcriptional activity of genes. Chromatin is a complex of DNA and proteins that forms the chromosomes in the nucleus of the cell. The chromatin structure can be altered by adding or removing chemical groups to histones (proteins that wrap around DNA) or DNA itself. These chemical groups can either activate or repress gene expression by changing the affinity of transcription factors (proteins that bind to DNA and initiate transcription) or other regulatory molecules. Non-coding RNAs are RNA molecules that do not code for proteins but can regulate gene expression by interacting with DNA, RNA, or proteins.
Epigenetic mechanisms provide a link between environmental stimuli and gene expression, and play an important role in various physiological and pathological processes, including drug addiction. Recent studies have shown that epigenetic mechanisms are involved in the regulation of neurotransmitter systems and neural plasticity in response to METH exposure. Neural plasticity is the ability of neurons to change their structure and function in response to experience or injury. Neural plasticity is essential for learning, memory, adaptation, and recovery.
The expression of some genes related to METH addiction is altered by epigenetic modifications, such as histone acetylation, methylation, ubiquitination, and non-coding RNA regulation. These epigenetic changes may affect the synaptic function and morphology, neuronal connectivity, and circuitry formation in the brain regions implicated in METH addiction. Moreover, some epigenetic modifications may persist for a long time after METH withdrawal, suggesting that they may contribute to the development and maintenance of METH addiction.
In this article, we will review the current literature on the epigenetic mechanisms of METH addiction. We will first introduce METH and its pharmacological effects, and then discuss the epigenetic regulation of neurotransmitter systems and neural plasticity by METH. We will focus on the changes of histone, DNA, and RNA during METH addiction, and the possible causes and consequences of their relationship with METH addiction. We will also provide some perspectives on the potential applications of epigenetic interventions for METH addiction treatment. The following figure directly shows the effect of METH subcutaneous injection on mice from three aspects of epigenetic mechanism type, action site and molecular level changes, which is also a relatively objective result obtained in this paper.
Mitophagy, a highly precise form of autophagy, plays a pivotal role in maintaining cellular homeostasis by selectively targeting and eliminating damaged mitochondria through a process known as mitophagy. Within this tightly regulated mechanism, dysfunctional mitochondria are specifically delivered to lysosomes for degradation. Disruptions in mitophagy have been implicated in a diverse range of pathological conditions, spanning diseases of the nervous system, cardiovascular system, cancer, aging, and metabolic syndrome. The elucidation of mitophagy's impact on cardiovascular disorders, liver diseases, metabolic syndromes, immune dysfunctions, inflammatory conditions, and cancer has significantly advanced our understanding of the complex pathogenesis underlying these conditions. These studies have shed light on the intricate connections between dysfunctional mitophagy and disease progression. Among the disorders associated with mitochondrial dysfunction, insulin resistance (IR) stands out as a prominent condition linked to metabolic disorders. IR is characterized by a diminished response to normal levels of insulin, necessitating higher insulin levels to trigger a typical physiological reaction. Hyperinsulinemia and metabolic disturbances often coexist with IR, primarily due to defects in insulin signal transduction. Oxidative stress, stemming from mitochondrial dysfunction, exerts dual effects in the context of insulin resistance. Initially, it disrupts insulin signaling pathways and subtly contributes to the development of insulin resistance. Additionally, by inducing mitochondrial damage and autophagy, oxidative stress indirectly impedes insulin signaling pathways. Consequently, mitophagy acts as a protective mechanism, encapsulating damaged or dysfunctional mitochondria through the autophagy-lysosome pathway. This efficient process eliminates excessive reactive. The intricate interplay between mitochondrial function, oxidative stress, mitophagy, and insulin resistance represents a captivating field of investigation in the realm of metabolic disorders. By unraveling the underlying complexities and comprehending the intricate relationships between these intertwined processes, researchers strive toward uncovering novel therapeutic strategies. With a particular focus on mitochondrial quality control and the maintenance of redox homeostasis, these interventions hold tremendous potential in mitigating insulin resistance and enhancing overall metabolic health. Emerging evidence from a myriad of studies has shed light on the active involvement of mitophagy in the pathogenesis of metabolic disorders. Notably, interventions such as exercise, drug therapies, and natural products have been documented to induce mitophagy, thereby exerting beneficial effects on metabolic health through the activation of diverse signaling pathways. Several pivotal signaling molecules, including AMPK, PINK1/Parkin, BNIP3/Nix, and FUNDC1, have been identified as key regulators of mitophagy and have been implicated in the favorable outcomes observed in metabolic disorders. Of particular interest is the unique role of PINK1/Parkin in mitophagy compared to other proteins involved in this process. PINK1/Parkin exerts influence on mitophagy through the ubiquitination of outer mitochondrial membrane proteins. Conversely, BNIP3/Nix and FUNDC1 modulate mitophagy through their interaction with LC3, while also displaying certain interrelationships with each other. In this comprehensive review, our objective is to investigate the intricate interplay between mitophagy and insulin resistance, elucidating the relevant signaling pathways and exploring the treatment strategies that have garnered attention in recent years. By assimilating and integrating these findings, we aim to establish a comprehensive understanding of the multifaceted roles and intricate mechanisms by which mitophagy influences insulin resistance. This endeavor, in turn, seeks to provide novel insights and serve as a catalyst for further research in the pursuit of innovative treatments targeting insulin resistance.
The World Health Organization has declared that the outbreak of Coronavirus disease 2019 (COVID-19) is a global pandemic. As mutations occurred in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the global epidemic still needs further concern. Worryingly, the effectiveness and neutralizing activity of existing antibodies and vaccines against SARS-CoV-2 variants is declining. There is an urgent need to find an effective antiviral medication with broad-spectrum inhibitory effects on novel coronavirus mutant strains against the SARS-CoV-2 infection. Neutralizing antibodies play an important role in the prevention and treatment of COVID-19. The interaction of Spike-Receptor-binding domain (Spike-RBD) of SARS-CoV-2 and human angiotensin-converting enzyme 2 (ACE2) is the first and critical step of SARS-CoV-2 infection. Hence, the SARS-CoV-2 Spike-RBD is a hot target for neutralizing antibodies development. Evusheld, the combination of Tixagevimab and Cilgavimab monoclonal antibodies (mAbs) targeting Spike-RBD exhibits neutralizing activity against BA.2.12.1, BA.4 and BA.5, which could be used as pre-exposure prophylaxis against SARS-CoV-2 infection. The nucleocapsid (N) protein is a conservative and high-abundance structural protein of SARS-CoV-2. The nCoV396 monoclonal antibody, isolated from the blood of convalescent COVID-19 patients against the N protein of SARS-CoV-2. This mAb not only showed neutralizing activity but also inhibits hyperactivation of complement and lung injury induced by N protein. The mAb 3E8 targeting ACE2 showed broadly neutralizing activity against SARS-CoV-2 and D614G、B.1.1.7、B.1.351、B.1.617.1 and P.1 variants in vitro and in vivo, but did not impact the biological activity of ACE2. Compared with neutralizing antibodies, small molecule inhibitors have several advantages, such as broad-spectrum inhibitory effect, low cost, and simple administration methods. Several small-molecule inhibitors disrupt viral binding by targeting the ACE2 and N-terminal domain (NTD) of SARS-CoV-2 Spike protein. Known drugs such as Chloroquine and Hydroxychloroquine could also block the infection of SARS-CoV-2 by interacting with residue Lys353 in the peptidase domain of ACE2. The transmembrane protease serine 2 (TMPRSS2) inhibitors Camostat mesylate and Proxalutamide inhibit infection by blocking TMPRSS2 mediates viral membrane fusion. The main protease inhibitor Paxlovid and RNA-dependent RNA polymerase inhibitor Azvudine have been approved for treatment of COVID-19 patients. This review summarizes the current research status of neutralizing antibodies and small molecule inhibitors and prospects for their application. We expect to provide more valuable information for further studies in this field.
Cells not only contain membrane-bound organelles (MBOs) but also membrane-less organelles (MLOs) formed by the condensation of many biomacromolecules. Examples include RNA-protein granules such as nucleoli and PML nuclear bodies in the nucleus, as well as stress granules and P-bodies in the cytoplasm. Phase separation is the basic organizing principle of the form of the condensates or membrane-less organelles (MLOs) of biomacromolecules including proteins and nucleic acids. In particular, liquid-liquid phase separation (LLPS) compartmentalizes and concentrates biological macromolecules into liquid condensates. It has been found that phase separation of biomacromolecules requires some typical intrinsic characteristics, such as intrinsically disordered regions, modular domains， and multivalent interactions. The phase separation of biomacromolecules plays a key role in many important cell activities. In recent years, the phase separation of the biomacromolecules phase has become a focus of research in gene transcriptional regulation. Transcriptional regulatory elements such as RNA polymerases, transcription factors (TFs), and super-enhancers (SEs) all play important roles through phase separation. Our group has previously reported for the first time that long-term inactivation or absence of assembly factors leads to the formation of condensates of RNA polymerase II (RNAPII) subunits in the cytoplasm, and this process is reversible, suggesting a novel regulatory model of the eukaryotic transcription machinery. The phase separation of biomacromolecules provides a biophysical understanding of the rapid transmission of transcriptional signals by a large number of TFs. Moreover, phase separation during transcriptional regulation is closely related to the occurrence of cancer. For example, the activation of oncogenes is usually associated with the formation of phase separation condensates at the SEs. In this review, the intrinsic characteristics of the formation of biomacromolecules phase separation and the important role of phase separation in transcriptional regulation are reviewed, which will provide a reference for understanding basic cell activities and gene regulation in cancer.
Polθ (DNA polymerase theta), also known as DNA polymerase θ, is the member of the DNA polymerase A family and plays a crucial role in the repair of DNA double-strand breaks (DSB). Polθ has three distinct structural domains: the N-terminal helicase-like domain with a conserved sequence, the C-terminal polymerase domain, and the central domain, which is a disordered sequence connecting these two regions. Notably，Polθ is the only known polymerase in eukaryotes that possesses helicase activity. However, it is also an error-prone polymerase.
When DNA DSBs occur, a specialized network consisting of at least four pathways, including Classical-Non Homologous End Joining (C-NHEJ), Homologous Recombination (HR), Single-Strand Annealing (SSA), and Alternative-End Joining (Alt-EJ) is responsible for their repair. In the absence of major DNA repair pathways like HR, cells rely on Alt-EJ pathway mediated by Polθ to repair damaged DNA and maintain genomic stability. Nevertheless due to the low fidelity of Polθ, Alt-EJ repair often leads to errors. Depletion of Polθ has shown to increases DSB formation and compromise genomic stability. Conversely, overexpression of Polθ has been associated with increases DNA damage markers and impairs cell cycle progression. As a result, the impact of Polθ on genome stability remains controversial.
Furthermore, overexpression of Polθ is frequently observed in cancer and is associated with a characteristic mutational signature and poor prognosis. Depleting Polθ in an HR-deficient background has been shown to impair cell viability, suggesting a synthetic lethal (SL) relationship between Polθ and HR factors. In recent years, targeted chemotherapy drugs that inhibit tumor growth have gained significant attention. However, off-target effects and drug resistance pose challenges for clinical application, particularly with Poly-ADP-ribose Polymerase inhibitor (PARPi). Blocking Polθ activity in HR-deficient tumor cells has been found to reverse PARPi resistance, making Polθ a very promising therapeutic target in cancer treatment.
The availability of crystal structures for both the helicase and the polymerase domain has facilitated the design of potent inhibitors of Polθ. Currently, several highly specific and effective small molecule inhibitors targeting Polθ, such as Novobiocin, RP-6685, and ART558, have been reported to effectively block various cancers with HR deficiency. The initial success of these inhibitors points to new directions for treating BRCA1/2-mutated tumors. Additionally, reducing the Alt-EJ repair pathway mediated by Polθ can improve HR repair efficiency and increase the chance of exogenous gene target integration (TI), suggesting potential new applications for Polθ inhibitors. This article reviews the recent research progress on the molecular function of Polθ and its involvement in the Alt-EJ pathway modification mechanism, providing insights for a deeper understanding of this field.
Chimeric RNA is a fusion transcript comprising of exon fragments from different genes; There are three splicing types: chromosome rearrangements, trans-splicing, cis-splicing, and the recently mentioned circular chimeric RNA. The traditional methods for the detection of chimeric RNA includes chromosome karyotype analysis, FISH, DNA microarray, etc., but their specificity, sensitivity and accuracy for the detection of chimeric RNA are poorly understood. With the development of high throughput sequencing analysis and next-generation sequencing technology has shown improved data processing ability and detection of chimeric RNA. Currently, detection methods making use of high-throughput sequencing datasets includes FusionCatcher, SOAPfuse, EricScript, etc. For validation of the detected chimeric RNA, the commonly used methods include PCR, RPA, agarose gel electrophoresis, sanger sequencing, etc. The development of newly introduced techniques has led to the discovery of different novel chimeric RNA, the third and fourth generation sequencing has also been developed and nearly mature, and the sequencing technology taking PacBio as an example has also brought a new dawn to the discovery of chimeric RNA, but each of them has its advantages and disadvantages, mainly focusing on its cost, false positive rate, detection time, etc. This paper basically describes various different techniques that can be utilized for the detection and validation of chimeric RNA.
The development of animal early embryos commences with the reprogramming of terminally differentiated gametes into totipotent zygotes following fertilization. During the initial stages of embryonic development, the transcriptional levels of zygotic genome remain silent and maternal gene products dominate the regulation of development. As embryonic development progresses, the maternal gene products undergo phased degradation while the zygotic genome gradually activates transcription, marking the transition from the maternal regulation to the zygotic genome regulation in early embryonic development, which is also referred to as the maternal-zygotic transition (MZT). Zygotic genome activation (ZGA) is a critical turning process in this transition, and its accurate occurrence is crucial for early embryonic development and cell fate decisions. However, the regulatory factors and molecular mechanisms of ZGA remain poorly understood. Studies have shown that ZGA varies greatly among different species and may be affected by a variety of regulatory factors such as DNA methylation, histone modification, non-coding RNA, chromatin remodeling and ZGA related factors. Here, we review the research progress of the above regulatory factors affecting ZGA, which can provide valuable insights for further investigations into the ZGA related mechanisms of early embryos.
Objective Gastric cancer (GC) seriously affects human health and life, and research has shown that it is closely related to the serine/glycine metabolism. The proliferation ability of tumor cells is greatly influenced by the metabolism of serine and glycine. In this work, a stable metabolic dynamic model of gastric cancer cells was established via a large-scale metabolic network dynamic modeling method in terms of a potential landscape description of stochastic and non-gradient systems. Based on the regulation of the model, a quantitative analysis was conducted to investigate the dynamic mechanism of serine/glycine metabolism affecting the proliferation of gastric cancer cells. Methods We introduced random noise to the kinetic equations of the general metabolic network, and applied stochastic kinetic decomposition to obtain the Lyapunov function of the metabolic network parameter space. A stable metabolic network was achieved by further reducing the change in the Lyapunov function tied to the stochastic fluctuations. Results Despite the unavailability of a large number of dynamic parameters, we were able to successfully construct a dynamic model for the metabolic network in gastric cancer cells. When extracellular serine is available, the model preferentially consumes serine. In addition, when the conversion rate of glycine to serine increases, the model significantly upregulates the steady-state fluxes of SAM and SAH. Conclusion In this paper, we provide evidence supporting the preferential uptake of serine by gastric cancer cells and the important role of serine/glycine conversion rate in SAM generation, which may affect the proliferation ability of gastric cancer cells by regulating the cellular methylation process. This provides a new idea and direction for targeted cancer therapy based on serine/glycine metabolism.
Mitochondrial quality control plays an important role in maintaining homeostasis of mitochondrial network and normal function of mitochondria. ATPase family AAA domain-containing protein 3A (ATAD3A) is one of the mitochondrial membrane proteins involved in the regulation of mitochondrial structure and function, mitochondrial dynamics, mitophagy and other important biological processes. Recent studies show that ATAD3A not only interacts with Mic60/Mitofilin and mitochondrial transcription factor A (TFAM) to maintain mitochondrial cristae morphology and oxidative phosphorylation, but also interacts with dynamin-related protein 1 (Drp1) to positively/negatively regulate mitochondrial fission. In addition, ATAD3A serves as a bridging factor between the translocase of the outer mitochondrial membrane (TOM) complex and translocase of the inner mitochondrial membr ane (TIM) complex to facilitate the import of PTEN-induced putative kinase protein 1 (PINK1) into mitochondria and its processing displays a pro-autophagic or anti-autophagic activity. This article reviews the role and mechanism of ATAD3A in regulating mitochondrial quality control. Firstly, as an inner mitochondrial membrane protein, ATAD3A is involved in maintaining the stability of mitochondrial crista structure, and its gene deletion or mutation will cause the loss and breakage of crista. Secondly, ATAD3A is also involved in maintaining mitochondrial respiratory function and mitochondrial nucleoid homeostasis, and its gene deletion or mutation can reduce the activity of mitochondrial respiratory chain complex and enhance the size and movement of nucleoid. Thirdly, ATAD3A participates in the negative regulation of mitochondrial fusion, but its role in mitochondrial fission may dependent on specific cell types, as it can promote and/or inhibit the mitochondrial fission by increasing and/or decreasing phosphorylation or oligomerization of Drp1. Finally, ATAD3A can interact with mitophagy-related proteins (e.g. PINK1, autophagy/beclin-1 regulator 1 (AMBRA1), acylglycerol kinase (AGK) ) to enhance/reduce PINK1-Parkin-dependent mitophagy.
zhangduo,xiazhi,shanghuayu.The role of membrane protein ATAD3A in the mitochondrial quality control[J]..Export: BibTexEndNote
Abstract Objective The advent of atomic force microscopy (AFM) provides a powerful tool for the studies of life sciences. Particularly, AFM-based indentation assay has become an important method for the detection of cellular mechanics, yielding numerous novel insights into the physiological and pathological activities from the single-cell level and considerably complementing traditional biochemical ensemble-averaged assays. However, current AFM indentation technology is mainly dependent on manual operation with low efficiency, seriously restricting its practical applications in the field of life sciences. Here, a method based on the combination of deep learning image recognition and AFM is developed for precisely and efficiently detecting the mechanical properties of single isolated cells and clustered cells. Methods The YOLO deep learning algorithm was used to recognize the central region of the cell in the optical image, the dual UNet neural network with an embedded vision transformer (ViT) module was used to recognize the peripheral regions of the cell, and the template matching algorithm was used to recognize the tip of the spherical probe. Based on the automatic determination of the positional relationships between the microsphere tip and the different parts of the cell, the AFM tip was accurately moved to the central and peripheral regions of the target cell for rapid measurements of cell mechanical properties. Two types of cells, including HEK 293 cell (human embryonic kidney cell) and HGC-27 cell (human undifferentiated gastric cancer cell), were used for the experiments. The Hertz model was applied to analyze the force curves obtained on cells to obtain cellular Young’s modulus. Results AFM probe can be precisely moved to the different parts (central areas and peripheral areas) of cells to perform mechanical measurements under the guidance of deep learning-based optical image automatic recognition. The experimental results show that the proposed method is not only suitable for single isolated cells, but also suitable for clustered cells. Conclusions The research demonstrates the great potential of deep learning image recognition to aid AFM in the precise and efficient detection of cellular mechanical properties mechanics, and combining deep learning-based image recognition with AFM will benefit the development of high-throughput AFM-based methodology to measure the mechanical properties of cells.
Lv Xiaolong,LI Mi.Deep Learning Image Recognition-assisted Atomic Force Microscopy for Precise and Efficient Detection of Single-cell Mechanical Properties[J]..Export: BibTexEndNote
R-spondin2(Rspo2) is a member of protein family RSPOs, which can be coupled to receptor 4/5 (leucine-rich repeat-containing g protein-coupled receptor 4/5, LGR4/5), cell surface transmembrane E3 ubiquitin ligase znrf3/rnf43 (zinc and ring finger 3/ring finger protein 43), heparan sulfate proteoglycan (Heparan sulfate proteoglycans, HSPGs) and the IQ motif (IQ gap 1) containing GTP enzyme activating protein 1 regulate the Wnt/β- catenin signaling pathway, which is the most widely studied signaling pathway and directly related to basic bone biology. Any problem in this pathway may have an impact on bone regulation. In recent years, it has been found that Rspo2 _ 2 can act on osteoblast, osteoclast and chondrocytes through Wnt/β-catenin, and take part in some bone diseases such as ossification of the posterior longitudinal ligament of the spine. OPLL), Osteoarthritis (OA) and rheumatoid arthritis (RA) occur and develop, so the study of Rspo2 may become a new therapeutic direction for bone-related diseases. Based on the latest research progress, this paper reviews the structure and main functions of Rspo2, the mechanism of Rspo2 regulating Wnt/β-catenin signaling pathway and its influence on skeletal system, in order to provide new ideas and ways for the prevention and treatment of bone-related diseases.
Circular RNAs (circRNAs) are a kind of non-coding RNA (ncRNA) with covalent closed-loop structure. They have attracted more and more attention because of their high stability, evolutionary conservatism, and tissue expression specificity. It has shown that circRNAs are involved in the development of a variety of diseases including malignant tumors recently. Nasopharyngeal Carcinoma (NPC) is a malignant tumor that occurs in the nasopharynx and has a unique ethnic and geographical distribution in South China and Southeast Asia. Epstein-Barr virus (EBV) infection is closely related to the development of NPC. Radiotherapy and chemotherapy are the mainstays of treatment for NPC. But tumor recurrence or distant metastasis is the leading cause of death in patients with NPC. Several studies have shown that circRNAs, as gene expression regulators, play an important role in NPC and affect the progression of NPC. This review mainly summarized the research status of abnormally expressed circRNAs in NPC and EBV-encoded circRNAs. We also discussed the possibility of circRNAs as a therapeutic target, diagnostic and prognostic marker for NPC.
Objective Hair is an essential skin appendage, primarily composed of keratins and keratin-associated proteins. The protein composition and proportion of hair samples vary among different races and sexes. Currently, there is a lack of efficient methods to extract hair proteins. This study aims to explore the application of quantitative hair proteomics in distinguishing individual hair characteristics. Method Based on the exploration of sample processing and lysis buffer using three hair samples, we developed a stable and efficient hair protein extraction method, named PLEE (PTM Lab for protein extraction from hair with high efficiency). We used the PLEE method to extract seven human hair samples and performed proteomic experiments on them using in-gel digestion method to produce data for analyzing hair protein composition and proportion among individuals. Results A total of 274 proteins were identified, among which 107 proteins were commonly present, and the number of non-common proteins ranged from 57-119, with some samples having unique identification proteins. Using the 107 commonly identified proteins for quantitative protein fractionation analysis, various samples were distinguished by clustering and principal component analysis, and technical repeated samples were merged, indicating the stability of the process. In addition, 10 key proteins (KRT33A; KRTAP9-6; KRT83; KRTAP7-1; KRT32; BLMH; KRT38; KRTAP11-1; NPAS1; KRTAP4-3) with large differences between individuals and stable protein identification within the same individual were screened. Conclusion The protein composition of hair varies among different individuals, and the 10 selected proteins are expected to be key proteins for distinguishing individual hair characteristics and have significant potential applications in individual identification and criminal investigation.
Ubiquitination, a diverse post-translational modification, is carried out by enzymes including E1-activating enzymes, E2-conjugating enzymes, E3 ligases, and deubiquitinating enzymes (DUBs). Ubiquitin itself possesses seven lysine residues and N-terminal methionine, allowing for the formation of polyubiquitin chains with different lengths and linkages. These chains exhibit various topologies that can be recognized by proteins containing ubiquitin-binding domain, thereby transmitting distinct cellular signals. To unravel the physiological mechanisms associated with ubiquitin, numerous ubiquitin probes have been developed. This review provides an overview of recent advancements in the field of ubiquitin probes, focusing on activity-based and affinity-based probes. Activity-based probes are designed to covalently bind to DUBs, E1s, or E3s, enabling the identification and characterization of these enzymes. Affinity-based probes, on the other hand, selectively bind to ubiquitin-binding domains, facilitating the identification of proteins that interact with ubiquitin. Moreover, this review comprehensively discusses the synthetic methodologies employed for the acquisition of ubiquitin probes. These includes meticulous discussions on the synthesis of individual monomeric modules, the establishment of isopeptide linkages, as well as the incorporation of reactive functional groups. Additionally, the review explores the emerging area of cell-penetrating ubiquitin probes and highlights their latest applications in living cells. These probes incorporate cell-penetrating peptides to enable their internalization into cells, allowing for direct visualization and manipulation of ubiquitin-modified proteins within their native environment. Overall, this review offers insights into the design, synthesis, and applications of ubiquitin probes, highlighting their significance in elucidating ubiquitin-mediated cellular processes.
Growth/Differentiation Factor-5(GDF-5) belongs to transforming growth factor β(TGF-β) family, which is expressed in bone, cartilage, heart, brain, kidney, skeletal muscle and tendon, liver, fat and other organs and tissues as well. GDF-5 binds to receptor BMPR - Ⅰ/BMPR - Ⅱ and activates different signaling pathways such as smad1/5/8, PI3K/Akt, p38-MAPK. For a long time, numerous studies have shown that GDF-5 plays an important role in protecting joints. However, researchers have found GDF-5 also plays significant biological functions in other organs. For example, GDF-5 improves cardiac function by reducing oxidative stress and fibrosis in infarcted hearts. GDF-5 can also reduce oxidative stress in the brain and increase the number of neurons in an effort to delay the progression of Alzheimer's disease and Parkinson's disease. It is a situation, research on GDF-5, at present, mainly focuses on the growth and repair of bone, cartilage and tendons, while there are few reports on its biological effects in other organs. Therefore, this article reviews and summarizes the research progress on GDF-5 and metabolic diseases in recent years in order to provide new insights and theoretical basis for the role of GDF-5 in improving metabolic diseases.
Di-(2-ethylhexyl) phthalate (DEHP) is currently one of the most widely used plasticizers, widely found in all kinds of items, such as children's toys and food packaging materials, but also added to wallpaper, cable protective agents and other building decoration materials. DEHP is toxic and absorbed by the human body through respiratory tract, digestive tract and skin contact, which can cause damage to multiple systems, especially the male reproductive system, and testis is an important target organ. Oxidative stress injury is the core mechanism of spermatogenesis disorder caused by DEHP. DEHP exposure can cause oxidative stress or ROS increase in germ cells, and on this basis, promote cell apoptosis or cause excessive autophagy. The toxicity of DEHP to Leydig cells is mainly to interfere with the synthesis of steroid hormones. For Sertoli cells, ferroptosis and destruction of the blood-testis barrier are common injury mechanisms. In addition, gene methylation caused by DEHP not only affects the spermatogenic process, but also has epigenetic effects on offspring. In this paper, we reviewed the pathological damage, germ cell toxicity and epigenetic effects of DEHP on testis, and focused on the damage and molecular mechanism on testicular spermatogenic cells, Leydig cells and Sertoli cells. Future research is required to elucidate the body's clearance mechanism and treatment plan after exposure to DEHP and whether DEHP will damage the function of myoid cells. It is hoped that this can provide new ideas for prevention and treatment of male reproductive disorders resulting from long-term exposure to plastic products.
Blood transfusion accuracy is crucial for disease treatment and emergency rescue. Prior to a blood transfusion, it is essential to perform a number of tests to assure proper clinical treatment and reduce the risk of complications. Pre-transfusion testing refers primarily to the blood group, coagulation, and infection to assure transfusion safety and prevent cross-infection. Blood type, cross-matching blood, fibrinogen, viral hepatitis, human immunodeficiency virus, and syphilis are routine pre-transfusion tests. Immunoassay is the traditional clinical pretransfusion detection method. With the expansion of clinical treatment requirements from hospital to on-site treatment, new technologies, such as electrochemical sensing, microfluidics, and spectroscopy technology, are being developed gradually for rapid detection prior to blood transfusion. The development of technologies including colloidal gold immunity and biochips has facilitated the shift from large-scale laboratory equipment to portable testing for pre-transfusion screening. Further, the introduction of artificial intelligence technologies such as machine learning, biometric technology, and computer vision has contributed to the advancement of intelligent pre-transfusion testing. This article reviews the various application scenarios, benefits, and drawbacks of different pre-transfusion detection technologies, analyzes the application of a series of new technologies in pre-transfusion detection and its future development trend, and provides a reference for promoting the development of pre-transfusion detection and even rapid disease marker detection.
Abstract Objective It was reported that the transthyretin (TTR) has a neuroprotective effect on Alzheimer’s disease (AD), which is manifested by the ability of TTR to inhibit the pathological aggregation of amyloid-beta (Aβ) protein. In this work, we investigated the mechanism of the interactions between TTR and Aβ at the molecular level to reveal the neuroprotective effect of TTR on AD. Method Protein-protein docking was used to explore the models of interaction between different structural forms of TTR and Aβ, and molecular dynamics simulation was further applied to investigate the dynamic process of the interaction between the two. Result Both TTR tetramer and monomer can interact with Aβ monomer, and the thyroxine-binding channel of TTR tetramer is the main binding site of Aβ monomer. In addition, the EF helix and EF loop of TTR tetramer were also able to bind Aβ monomer. When the TTR tetramer dissociates, the hydrophobic site of the internal TTR monomer is exposed, which has a strong affinity for Aβ monomer. For the interaction between Aβ aggregates and TTR, a higher degree of aggregation can be formed between TTR monomer and Aβ aggregates due to the β-sheet-rich property of TTR monomer and Aβ aggregates, which may therefore reduce the cytotoxicity of Aβ aggregates. Conclusion Both TTR tetramer and monomer can inhibit Aβ aggregation by “sequestering” Aβ monomer, while TTR monomer can reduce the cytotoxicity of Aβ aggregates by forming large co-aggregation with Aβ Aggregates. This work can provide an important theoretical basis for the design and discovery of anti-AD drugs based on the neuroprotective effects of TTR.
Nanozyme is novel nanoparticle with enzyme-like activity, which can be classified into peroxidase-like nanozyme, catalase-like nanozyme, superoxide dismutase-like nanozyme, oxidase-like nanozyme and hydrolase-like nanozyme according to the type of reaction they catalyze. Since researchers first discovered Fe3O4 nanoparticles with peroxidase-like activity in 2007, a variety of nanoparticles have been successively found to have catalytic activity and applied in bioassays, inflammation control, antioxidant damage and tumor therapy, playing a key role in disease diagnosis and treatment.
We summarize the use of nanozymes with different classes of enzymatic activity in the diagnosis and treatment of diseases and describe the main factors influencing nanozyme activity. Lin et al. identified an Mn-based peroxidase-like nanoparticle enzyme that induces the reduction of glutathione in tumors to produce glutathione disulfide and Mn2+, which induces the production of ROS in tumor cells by breaking down H2O2 in physiological media through Fenton-like action, thereby inhibiting tumor cell growth. To address the limitation of tumor tissue hypoxia during photodynamic tumor therapy, Wang et al. used hydrogen peroxide nanozymes to catalyze H2O2 to produce oxygen, which significantly enhanced the effect of photodynamic therapy. In pathological states, where excess superoxide radicals are produced in the body, superoxide dismutase-like nanozymes are able to selectively regulate intracellular ROS levels, thereby protecting normal cells and slowing down the degradation of cellular function. Based on this principle, Shi et al. have designed an engineered nanosponge that can save nerve cells by rapidly scavenging free radicals and providing timely oxygenation before thrombolysis. Starvation therapy, in which glucose oxidase catalyzes the hydrolysis of glucose to gluconic acid and hydrogen peroxide in cancer cells with the involvement of oxygen, attenuates glycolysis and the production of intermediate metabolites such as nucleotides, lipids and amino acids, was used by Hao et al. to synthesize an oxidase-like nanozyme that achieved effective inhibition of tumor growth. Furthermore, by fine-tuning the Lewis acidity of the metal cluster to improve the intrinsic activity of the hydrolase nanozyme and providing a shortened ligand length to increase the density of its active site, Li et al. synthesized a hydrolase-like nanozyme capable of cleaving phosphate bonds, amide bonds, glycosidic bonds and even biofilms with high efficiency in hydrolyzing the substrate. All these effects depend on the size, morphology, composition, surface modification and environmental media of the nanozyme, which are important aspects to consider in order to improve the catalytic efficiency of the nanozyme and have important implications for the development of nanozyme.
Although some progress has been made in the research of nanozymes in disease treatment and diagnosis, there are still some problems, for example, the catalytic rate of nanozymes is still difficult to reach the level of natural enzymes in vivo, the toxic effects of some heavy metal nanozymes material itself, etc. Therefore, the construction of nanozyme systems with multiple functions, good biocompatibility and high targeting efficiency, and their large-scale application in diagnosis and treatment is still an urgent problem to be solved. (1) To improve the selectivity and specificity of nanozymes. By using antibody coupling, the nanoparticles are able to specifically bind to antigens that are overexpressed in certain cancer cells. It also significantly improves cellular internalization through antigen-mediated endocytosis and enhances the enrichment of nanozymes in target tissues, thereby improving targeting during tumor therapy. Some exogenous stimuli such as laser and ultrasound are used as triggers to control the activation of nanozymes and achieve specific activation of nanozyme. (2) To explore more practical and safer nanozymes and their catalytic mechanisms: biocompatible, clinically proven material molecules can be used for the synthesis of nanoparticles. (3) To solve the problem of its standardization and promote the large-scale clinical application of nanozymes in biomonitoring. Thus, it can go out of the laboratory and face the market to serve human health in more fields, which is one of the future trends of nanozyme development.
Objective : Phosphatidylinositol 3 kinases ( PI3Ks ) play an important role in cell directional movement by regulating F-actin. However, the structure and function of PI3Ks are complex. The role of PI3Ks in cell electrotaxis is not fully understood. Therefore, in this study, the model organism Dictyostelium discoideum cells were used as experimental materials to explore the role of PI3K1 and PI3K2 in electrotaxis.
Methods : Firstly, PI3K1 coding gene pikA knockout mutant and PI3K2 coding gene pikB knockout mutant were constructed by CRISPR / Cas9 system. Secondly, two mutants were placed in a DC electric field with a strength of 12 V / cm and the electrotaxis were analyzed.
Results : Data analysis showed that the direction index of wild-type cells in DC electric field was 0.86 ± 0.03, while the direction index of pikA- and pikB- mutants in DC electric field was 0.95 ± 0.02 and 0.94 ± 0.03, respectively. In addition, the average trajectory speed of wild-type cells in the electric field was 3.34 ± 0.08 μm / min, while the average trajectory speed of pikA- and pikB- mutants were 4.85 ± 0.20 μm / min and 5.48 ± 0.15 μm / min, respectively. The t test showed that there were significant differences in the directedness index and speed between the mutant and wild type. Western blot results showed that both phosphorylated Akt and phosphorylated ERK were significantly increased in pikA- and pikB- mutants.
Conclusion : PI3K1 and PI3K2 may inhibit the electrotaxis of Dictyostelium discoideum cells by increasing the activity of Akt and ERK.
Spatial environment includes multiple scales, which can be specifically divided into operable near-scale figural space, navigable space consisting of single-viewpoint space and environmental space, and large-scale geographic space. It is very important for human and animal's daily life to distinguish the spatial environment at different scales. The representation of spatial scale is related to its corresponding functional needs, and the parietal lobe is responsible for the representation of near-scale space. Navigable spatial representation in hippocampus and cerebral cortex showed a "coarse to fine" gradient along the posterior to anterior axis. However, the scale representation of abstract social space shows a dichotomy. Future research should focus on temporal dynamics of spatial scale representation and the influence of spatial scale on the format of the cognitive map.
WU Wen-Ya,WANG Liang.Neural representation of multiple spatial scales[J]..Export: BibTexEndNote
Abstract Objective Recent successful restoration of the native conformation and function of the complementary-determining regions (CDRs) of antibodies on gold nanoparticles (AuNPs) demonstrates that the era of molecular conformational engineering is dawning. Basically, molecular conformational engineering aims to precisely tune flexible non-functional molecules into special conformations to carry out novel functions, in the same way as protein folding. In order to explore the general applicability of molecular conformational engineering, as well as to reveal the mechanism of protein structure-function relationship, the objective of this work is to restore the native conformation and function of the CDRs of an antibody on platinum nanoparticles (PtNPs). Method The CDR fragment of the anti-lysozyme antibody cAB-lys3, which has no stable conformation or function in free state, was conjugated onto the surface of PtNPs through two Pt-S bonds. The original antigen-recognizing function of the CDR restored on PtNPs was assessed by the specific inhibition of the enzymatic activity of lysozyme by the PtNP-CDR conjugates. Results After optimization of the peptide density on the surface of PtNPs and modification of PtNPs with polyethylene glycol (PEG), the resulted PtNP-based hybrid artificial antibody (PtNP-10EG-30P1), dubbed Platinumbody, could bind specifically to lysozyme and significantly inhibit the activity of lysozyme. Conclusion This is the first time that the fragment of a protein could refold on PtNPs. Together with the previous Goldbody and Silverbody, current work demonstrates that artificial proteins could be generally created by restoration of the native conformation of natural proteins fragments on NPs.
Immunoassays are widely used in medicine, food, environment and other fields due to they have the advantages of simpleness, rapidness and accuracy. Combining immunoassays with nanomaterials can improve the performance of immunoassays. Compared with traditional nanomaterials, upconversion nanoparticles(UCNPs) have excellent optical properties such as good photostability, long luminescence lifetime and narrow and tunable emission bands, which can significantly reduce background noise and improve analytical sensitivity when combined with immunoassay. This paper briefly introduces the luminescence mechanism of UCNPs, summarizes the synthesis and surface modification methods of UCNPs. And then five UCNPs-based immunoassay techniques, namely, fluorescence resonance energy transfer, inner filter effect, magnetic separation technique, upconversion-linked immunosorbent assay and upconversion immunochromatography, are discussed in detail. These sensing protocols of UCNPs-based immunoassays have been successfully utilized to detect various targets, including small molecules, macromolecules, and pathogens, all of which closely related to food safety, human health, and environmental pollution. Finally, the challenges and prospects of this technique are summarized and prospected. Although the UCNPs immunoassays based on antibodies and antigens have made great progress, most of the research is still in the stage of laboratory, and there is a long way to go to realize its social applications. There is a series of challenges need to be overcome:(1) Designing excellent water soluble and dispersive upconversion nanomaterials is needed. Hydrophilic ligands are bound to smaller upconversion nanoparticles and removing hydrophobic surface ligands are the most widely used methods to improve solubility and dispersity. (2) Multi-detection technology platforms and multi-mode simultaneous detection platforms have great potential, which will improve the efficiency of point of care detection. (3) The researchers also need to focus on some important problems. For examples, the upconversion luminescence efficiency of UCNPs is difficult to maintain, the synthesis method is complex, and the surface modification degree and functionalization are difficult to control.
Circulating tumor DNA (ctDNA) comes from tumor, reflecting the genetic information of the tumor well, and will change with the progress of the tumor. In recent years, the unique capabilities of ctDNA have attracted much attention and been widely studied. In this paper, based on the summary of the source, properties and sample processing of ctDNA, its detection technology and application in cancer diagnosis and treatment are reviewed. The roles and importance of ctDNA reference material in second-generation sequencing are described. The urgency of establishing uniform standards and specifications of ctDNA in various processes, such as samples collection, storage, quantitative testing and data analysis, has been pointed out.
Purpose: TePixD (Tll0078) is a blue light-using flavin (BLUF) photoreceptor protein from Thermosynechococcus elongatus BP-1. TePixD protein has a conserved Tyr8-Gln50-Met93 triad around the FAD pocket to mediate the proton-coupled electron transfer (PCET) process. But the detailed light response mechanism needs further study. We aimed to elucidate the structure and biochemical properties of TePixD mutants at key light response sites to analyze the light response process of TePixD.
Methods: We employed X-ray crystallography to resolve the crystal structure of the TePixD Y8F mutant. The side chain of Tyr8 is involved in PCET while Phe8 in mutation loses the function due to the loss of its hydroxyl group. We compared the structure of TePixD Y8F mutation to TePixD wild type (WT) and its homology protein SyPixD Y8F. Using multi-angle light scattering (MALS), we analyzed the oligomerization of multiple TePixD mutations (Y8F, Q50L, W91F, Y8F/W91F, and Q50L/W91F), focusing specifically on mutational sites that are critical residues for the protein’s photo response to dark and light conditions.
Results: We resolved the crystal structure of the TePixD Y8F mutant at a resolution of 2.54 ? and found that it shares a similar overall structure with the TePixD WT but exhibits significant differences from the SyPixD Y8F structure. Biochemical analysis revealed differences in molecular weight and elution profiles between the TePixD mutants and the WT under dark and light conditions, indicating the perturbation on the light-induced conformational change by the mutants.
Conclusion: Our structure determination and biochemical analyses will add information to reveal the light response mechanism of BLUF proteins.
Intestinal organoids are constructed by crypts or stem cells from the intestine under the 3D support of the culture matrix. They contain all mature cells of the intestine, and have become a new and efficient platform for studying the mechanism of intestinal diseases. Compared with 2D cell culture, organoid can not only more effectively simulate the physiological structure and function of the intestine, but also better restore the true ecology of the intestine in different external environments. Therefore, it is more widely used in the study of pathogenesis of different intestinal diseases. This article reviewed the new progress of intestinal organ like culture, and the application and progress in the pathogenesis of inflammatory bowel diseases, colorectal cancer and celiac disease in recent years, and also discussed the application in drug research and development and screening.
Objective Direct continuous monitoring of arterial blood pressure is invasive and continuous monitoring cannot be achieved by traditional cuffed indirect blood pressure measurement methods. Previously, continuous non-invasive arterial blood pressure monitoring was achieved by using photoplethysmography (PPG), but it is discrete values of systolic and diastolic blood pressures rather than continuous values constructing arterial blood pressure waves. This study aimed to reconstruct arterial blood pressure wave signal based on CNN-LSTM using PPG to achieve continuous non-invasive arterial blood pressure monitoring. Method A CNN-LSTM hybrid neural network model was constructed, and the PPG and arterial blood pressure wave synchronized recorded signal data from the MIMIC (Medical Information Mart for Intensive Care) were used. The PPG signals were input to this model after noise reduction, normalization, and sliding window segmentation. The corresponding arterial blood pressure waves were reconstructed from PPG by using the CNN-LSTM hybrid model. Results When using the CNN-LSTM neural network with a window length of 312, the error between the reconstructed arterial blood pressure values and the actual arterial blood pressure values was minimal: the values of MAE(Mean Absolute Error) and RMSE(Root Mean Square Error) were 2.79(mmHg) and 4.24(mmHg), respectively, and the cosine similarity is the optimal. The reconstructed arterial blood pressure values were highly correlated with the actual arterial blood pressure values, which met the Association for the Advancement of Medical Instrumentation (AAMI) standards. Conclusion CNN-LSTM hybrid neural network can reconstruct arterial blood pressure wave signal using PPG to achieve continuous non-invasive arterial blood pressure monitoring.
Wu Jiaze,Liang Hao,Chen Ming.Arterial Blood Pressure Wave Signal Reconstruction using Photoplethysmography by CNN-LSTM Model[J]..Export: BibTexEndNote
Outer membrane vesicles (OMVs) are nanoscale vesicles secreted by Gram-negative bacteria. As a unique bacterial secretion, OMV secretion can help bacteria maintain the outer membrane stability or remove harmful substances. Studies have shown that local separation of outer membrane and peptidoglycan layers led by abnormalities in outer membrane protein function, abnormal structure or excessive accumulation of LPS, and erroneous accumulation of phospholipids in the outer leaflet, which can all lead to bacterial outer membrane protrusion and eventually bud formation of OMVs. Since OMVs are mainly composed of bacterial outer membrane and periplasmic components, the pathogen-associated molecular patterns (PAMPs) on their surface can trigger strong immune responses. For example, OMVs can recruit and activate neutrophils, polarize macrophages to secrete large amounts of inflammatory factors. More importantly, OMVs can act as adjuvants to induce DC maturation to enhance adaptive immune response in the body. At the same time, OMVs are derived from bacteria, which make it easy to modify. The methods by genetic engineering and others can improve their tumor targeting, give them new functions, or reduce their immunotoxicity, which is conducive to their application in tumor therapy. OMVs not only induce apoptosis or pyroptosis of tumor cells, but also regulate the host immune system, which makes OMVs themselves have a certain killing effect on tumors. In addition, the tendency of neutrophils to inflammatory tumor sites and the formation of neutrophil extracellular traps enable OMVs to target tumor sites, and the suitable size and the characteristic that they are easily taken up by DCs give OMVs a certain lymphatic targeting ability. Therefore, OMVs are often employed as excellent drug or vaccine carriers in tumor therapy. This review mainly discusses the biological mechanism of OMVs, the regulatory effects of OMVs on immune cells, the functional modification strategies of OMVs, and their research progress in tumor therapy
Objective N6-methyladenosine (m6A) is the most common and abundant chemical modification in RNA and plays an important role in many biological processes. Several computational methods have been developed to predict m6A methylation sites. However, these methods lack robustness when targeting different species or different tissues. To improve the robustness of the prediction performance of m6A methylation sites in different tissues, this paper proposed a double-layer bidirectional gated recurrent unit (BiGRU) network model that combines reverse sequence information to extract higher-level features of the data. Method Some representative mammalian tissue m6A methylation site datasets were selected as the training datasets. Based on a BiGRU, a double-layer BiGRU network was constructed by collocation of the model network, the model structure, the number of layers and the optimizer. Results The model was applied to predict m6A methylation sites in 11 human, mouse and rat tissues, and the prediction performance was compared with that of other methods using the same tissues. The results demonstrated that the average area under the receiver operating characteristic curve (AUC) predicted by the proposed model reached 93.72%, equaling that of the best prediction method at present. The values of accuracy (ACC) , sensitivity (SN), specificity (SP) and Matthews correlation coefficient (MCC) were 90.07%, 90.30%, 89.84% and 80.17%, respectively, which were higher than those of the current methods for predicting m6A methylation sites. Conclusion compared with that of existing research methods, the prediction accuracy of the double-layer BiGRU network was the highest for identifying m6A methylation sites in the 11 tissues, indicating that the method proposed in this study has an excellent generalizability.
Exosome is a kind of extracellular vesicles secreted by cells to the outside. Biogenesis mainly involves two invaginations of the cytoplasmic membrane, the formation of multivesicular bodies, and the release of exosomes. Exosomes have abundant and diverse inclusions—including landmark membrane proteins, soluble proteins, various RNA molecules and DNA fragments, etc. Cells can achieve intercellular signal communication by secreting and receiving exosomes. Via interaction of ligand molecules on the exosome membrane with receptors on the surface of other cytoplasmic membranes, exosomes can activate cell signal transduction or fuse with the cell membrane to release its contents into the cytoplasm to exert regulatory functions. In the central nervous system, exosomes secreted by neurons and various glial cells can mediate wired synaptic signal transmission, but mainly play a role similar to neuromodulator by way of volume transmission. In this paper, the biogenesis of exosomes and important functional components are described in detail, and the characteristics of neural exosomes in the biogenesis, content sorting and controlled release are compared with those of synaptic vesicles. We further review the research progress on the physiological functions of neural exosomes on the central nervous system and their roles in the occurrence and development of neurodegenerative diseases and major depressive disorder. We also prospect the application of exosomes in the early diagnosis and targeted therapy of nervous system diseases.
RNA editing, an essential post-transcriptional reaction occurring in double-stranded RNA (dsRNA), generates informational diversity in the transcriptome and proteome. In mammals, the main type of RNA editing is the conversion of adenosine to inosine (A-to-I), processed by adenosine deaminases acting on the RNAs (ADARs) family, and interpreted as guanosine during nucleotide base-pairing. It has been reported that millions of nucleotide sites in human transcriptome undergo A-to-I editing events, catalyzed by the primarily responsible enzyme, ADAR1. In hematological malignancies including myeloid/lymphocytic leukemia and multiple myeloma, dysregulation of ADAR1 directly impacts the A-to-I editing states occurring in coding regions, non-coding regions, and immature miRNA precursors. Subsequently, aberrant A-to-I editing states result in altered molecular events, such as protein-coding sequence changes, intron retention, alternative splicing, and miRNA biogenesis inhibition. As a vital factor of the generation and stemness maintenance in leukemia stem cells (LSCs), disordered RNA editing drives the chaos of molecular regulatory network and ultimately promotes the cell proliferation, apoptosis inhibition and drug resistance. At present, novel drugs designed to target RNA editing (e.g. rebecsinib) are under development and have achieved outstanding results in animal experiments. Compare with traditional antitumor drugs, epigenetic antitumor drugs are expected to overcome the shackle of drug resistance and recurrence in hematological malignancies, and provide new treatment options for patients. This review summarized the recent advances in the regulation mechanism of ADAR1-mediated RNA editing events in hematologic malignancies, and further discussed the medical potential and clinical application of ADAR1.
Objective The traditional Chinese medicine Strychnos nux-vomica L. (SN) has the clinical effect of reducing swelling and relieving pain; however, SN is toxic due to its alkaloid components. Little is known about the endogenous metabolic changes induced by SN toxicity in rats and their potential effects on the metabolic dysregulation of intestinal microbiota. Therefore, toxicological investigation of SN is of great significance to its safety assessment. Methods In this study, the toxic mechanisms of SN were explored using a combination of metabolomics and 16S rRNA gene sequencing. The toxic dose, intensity, and target organ of SN were determined in rats using acute, cumulative, and subacute toxicity tests. UHPLC-MS was used to analyze the serum, liver, and renal samples of rats after intragastric SN administration. The decision tree and K Nearest Neighbor (KNN) model were established based on the bootstrap aggregation (bagging) algorithm to classify the omics data. After samples were extracted from rat feces, the high-throughput sequencing platform was used to analyze the 16S rRNA V3-V4 region of bacteria. Results The Bagging algorithm improved the accuracy of sample classification. Twelve biomarkers were identified, where their metabolic dysregulation may be responsible for SN toxicity in vivo. Several types of bacteria such as Bacteroidetes, Anaerostipes, Oscillospira and Bilophila, were demonstrated to be closely related to physiological indices of renal and liver function, indicating that SN-induced liver and kidney damage may be related to the disturbance of these intestinal bacteria. Conclusion The toxicity mechanism of SN was revealed in vivo, which provides a scientific basis for the safe and rational clinical use of SN.
wangxiye,baimeirong,jiangmingyang,lidan,baimeirong.Study on the Toxicity of Strychnos Nux-vomica L. in vivo in Rats - Application of Bagging Algorithm and 16S rRNA Gene Sequencing Technology in Toxicology Research[J]..Export: BibTexEndNote
Glioma is the most common malignancy of the central nervous system, originating mainly from glial cells. Because of its highly aggressive nature, glioma has one of the highest rates of death among all types of cancer. Therefore, it is very imptortant to develop new therapeutic approaches and drugs for glioma treatment. Instead of activate the telomerase, approximately 30% of glioma use alternative lenthening of telomere (ALT) to maintain telomere length. The mechanism of ALT development is poorly understood, however, some genetic mutations have been reported to induce the development of ALT glioma, such as ATRX, IDH1R132H, p53, etc. The lack of ALT glioma cell lines and preclinical ALT glioma models has limited the mechanistic studies of ALT glioma. Therefore, this review listed ALT glioma cell lines that derived from primary culture or gene editing in the last decade, as well as the xenografted animal models established by ALT glioma cell lines, and discussed the role and significance these cell and animal models play in preclinical studies.
The brain's neural circuits consist of a large number of highly unstable networks. Despite the existence of mangy internal and external factors that continuously disturb the balance, our brains employ an array of homeostatic mechanisms that allow neurons or neural circuits to sense how active they are, and when they deviate from a target value, whereby a force must be generated to move neuronal activity back toward this target. Sleep is one of the well-known physiological states in the regulation of homeostasis. Sleep pressure increases during wakefulness and decreases during sleep. When sleep is lost (e.g., sleep deprivation), this loss is compensated by extending or strengthening subsequent sleep. These phenomena are known as sleep homeostasis. The dysregulation of sleep homeostasis accompanies brain-related disease such as schizophrenia, bipolar disorder, major depressive disorders, autism spectrum disorders and so on. More importantly, it can significantly undermine the basis of traditional sleep hygiene practices for these diseases. Therefore, clarifying the mechanism of sleep homeostasis is important for therapy, but it remains an unsolved mystery. In addition to pharmacological treatment, non-invasive brain stimulation has become one of the most promising tools for clinical treatment in recent years due to its low cost, portability and low incidence of side effects. In order to promote relevant technologies, this review will focus on the electrophysiological mechanisms of sleep homeostasis. We first discuss the electrophysiological marker of sleep homeostasis, slow-wave activity, then move to the neuronal firing rates, finally discuss more aspects of sleep homeostasis, including differences in brain area, sleep stages, learning and individual differences.
Oligonucleotide drugs have experienced accelerated development in the past 10 years, and some of them have been used in clinical treatment. Because of its convenient design, flexible sequence, and high specificity, it is expected to solve the “undruggable” challenge of many targets which are difficult in drug development. Moreover, its clinical transformation period and cost are relatively low, which makes oligonucleotide drug become the frontier of emerging biotechnology drug discovery. Brain diseases, including neurodegenerative diseases, glioma, and motor neuron diseases, are currently incurable, and most of them are age-related. Due to the complex etiology, many targets are difficult to be drugged. At the same time, the existence of the barrier system "blood-brain barrier" in the brain makes most drugs unable to achieve effective accumulation at brain lesions, and many small molecule drugs have failed in clinical transformation. The specificity and sequence flexibility of oligonucleotide acid drugs provide new possibilities for drug development, but they also face the challenge of brain delivery. Although a variety of oligonucleotide drugs have been used in the medical market, brain-targeted oligonucleotide drugs are still extremely rare. This article reviewed recent advances and discussed key topics and clinical transformation challenges in this field, such as clinical approval cases, bottlenecks of brain-targeted delivery and current strategies, as well as potential targets for aging-related brain diseases.
Renal cell carcinoma (RCC) is the primary malignant neoplasm. The ubiquitin-proteasome system (UPS) is crucial to the control of protein level and regulation of physiological and pathological processes. Deubiquitinases (DUBs), key components of UPS, specifically removing ubiquitin chains from the target protein, have showed crucial roles for protein homeostasis and quality control by rigidly regulating the balance between ubiquitination and deubiquitination in normal physiology. Accumulating studies indicate that abnormal function DUBs is associated with the progression and metastasis of RCC. Depending on the substrates, some DUBs may suppress RCC while others promote. Herein, we review recent research advances in RCC-associated DUBs, describe their classification, functional roles, summarize the role and mechanisms of action of DUBs in RCC and discuss the potential of targeting DUBs for cancer treatment.
luoxia,jinxiaofeng.The roles of deubiquitinases in Renal cell carcinoma[J]..Export: BibTexEndNote
The UV cross-linking immunoprecipitation (CLIP) technique was first established in 2003. Sequences of target RNAs and binding sites of specific RNA-binding proteins (RBPs) were identified within the entire transcriptome by UV cross-linking, immunoprecipitation, reverse transcription, and subsequent high-throughput sequencing. Over the last 20 years, CLIP has been continuously modified and improved. Advanced operability and accuracy have extended its application category.
Currently, the widely used CLIP technologies include high-throughput sequencing with crosslinking-immunoprecipitation (HITS-CLIP), photoactivatable-ribonucleoside-enhanced CLIP (PAR-CLIP), individual nucleotide resolution CLIP (iCLIP), Enhanced CLIP (eCLIP), infrared-CLIP (irCLIP), etc. HITS-CLIP combines high-throughput sequencing with UV cross-linking immunoprecipitation. The 254nm UV cross-linking and RNAase digestion steps allow the technology to capture transient intracellular RBP-RNA interactions; however, there are limitations in the efficiency of UV cross-linking, with low resolution and high intrinsic background noise. For PAR-CLIP, photoactivatable ribonucleoside was incorporated into RNA molecules, and RBP cross-linked with RNA by 365 nm UV light to improve cross-linking efficiency and resolution. Cross-linking mediated single-base mutations provide more accurate binding site information and reduce interference from background sequences. Long-term alternative nucleotide incorporation, on the other hand, can be cytotoxic and may skew experimental results. iCLIP can identify RBP-RNA cross-linking sites at the single nucleotide level through cDNA circularization and subsequent re-linearization steps, but it has more experimental procedures, and partial cDNAs lost in the circularization step are inevitable. eCLIP discards the radioisotope labeling procedure and reduces RNA loss by ligating adaptors in two separate steps, greatly improving the library-building efficiency, and reducing bias associated with PCR amplification; however, the efficiency of immunoprecipitation cannot be visually assessed at the early stage of the experiment. The irCLIP technique replaces radioisotopes with infrared dyes and greatly reduces the initial number of cells required for the experiment; however, an infrared imaging scanner is essential for the irCLIP application. To address more particular scientific issues, derivative CLIP-related techniques such as PAPERCLIP, cTag-PAPERCLIP, hiCLIP, and tiCLIP have also been developed in recent years.
In practice, the aforementioned CLIP approaches have their advantages and disadvantages. When deciding on a technical strategy, we should take into account our experimental objectives and conditions, such as whether we need to precisely define the RNA site for binding to RBP; whether we have the necessary experimental conditions for working with radioisotopes or performing infrared imaging; the amount of initial sample size, and so on. In addition, the CLIP technique has a relatively large number of procedures and can be divided into several successive experimental modules. We can try to combine modules from different mainstream CLIP technologies to meet our experimental requirements, which also gives us more opportunities to improve and refine them and to build more targeted derivative CLIP technologies according to our research objectives.
Objective Transcription factor NFE2 was observed abnormal expression in myeloproliferative neoplasm (MPN) patients. However, how NFE2 is transcriptionally regulated remain ambiguous.
Method Active enhancers were predicted by public NGS data and conformed experimentally via dual luciferase reporter assay. After that, PRO-seq and GRO-seq data was used to detect enhancer RNAs transcribed from these enhancers. RACE was utilized to clone the full length eRNA transcripts, and RT-qPCR was used to measure their expression in different leukemia cell lines as well as the transcript levels during induced differentiation. Finally, to investigate the molecular function of the eRNA, overexpression and knockdown of the eRNA via lentivirus system was performed in K562 cells.
Results We identified three enhancers regulating NFE2 transcription, which located at -3.6k, -6.2k and +6.3k from NFE2 TSS respectively. At the -3.6k enhancer, we cloned an eRNA transcript and characterized that as a lncRNA which was expressed and located in nucleus in three types of leukemia cell lines. When this lncRNA was overexpression, NFE2 was upregulated and decreases of K562 cell proliferation and migration ability were observed. While knocking down of this lncRNA, opposite effects were found.
Conclusion We identified an enhancer lncRNA that regulate NFE2 transcription positively and suppress K562 cell proliferation.
Tumor is one of the major diseases that endanger people's health. At present, the treatments used for tumor include surgery, chemotherapy, radiotherapy and so on. Nonetheless, the traditional treatments have some disadvantages, such as insufficient treatment effect, liable to cause multidrug resistance, toxicity and side effect, etc. Further research and exploration of tumor treatment schemes are still necessary. As the energy converter of cells, mitochondria are currently considered to be one of the most important targets for the design of new drugs for tumor, cardiovascular and neurological diseases. Nano-drug delivery carriers have the characteristics of being easily modified with active targeting groups, and it can achieve accurate targeted drug delivery to cells and organelles. This paper reviews the application of mitochondrial targeted nanoparticles in tumor diagnosis and treatment from the aspects of inhibiting tumor cell proliferation, promoting tumor cell apoptosis, inhibiting tumor recurrence and metastasis, and inducing cell autophagy.
MXenes is an emerging two-dimensional (2D) material, which was composed of layered transition metal carbides and/or nitrides, have attracted enormous attention in the past decade since their innovative discovery by Gogotsi and Barsoum in 2011. The general formula of MXenes is Mn+1XnTx (n = 1-4), where M represents transition metal elements (such as Ti, Nb, Ta, etc.), X represents carbon and/or nitrogen, and Tx represents surface terminations (such as -OH, -F, =O, etc). In recent years, MXenes have been widely applied in the biological field due to their high biocompatibility, abundant surface groups, good conductivity and photothermal properties. Due to the strong absorption of laser in the near infrared region, strong X-ray attenuation ability and surface easily modified by various molecules or nanoparticles, MXenes have been used as photothermal agents and contrast agents in the tumor therapy and tumor diagnosis. This paper reviews the application of MXenes and MXenes-based composites in tumor therapy and active targeting tumor therapy. According to the modal of action on tumor cells, it was divided into monotherapy, bimodal therapy and trimodal therapy. Among them, the monotherapy mainly used the photothermal properties of MXenes for photothermal therapy, studies have found that MXenes QDs can be used for chemodynamic therapy. In addition, sonodynamic therapy can also be achieved by loading the sonosensitizers on the surface of MXenes. Bimodal therapy and trimodal therapy are mainly used to load anticancer drugs, photosensitizers, metal particles and other substances on the surface of MXenes to achieve combination therapy. In contrast to the limited treatment efficacy and possible side effects arising from monotherapy, the development of bimodal therapy and trimodal therapy may harbor the collective merits of respective individual treatments and give rise to much higher anticancer efficacy at lower dosage of therapeutic agents administered, thus avoiding high-dose-induced side effects. The combined use of multiple treatments displayed superior advantages over monotherapy in producing an improved therapy outcome. According to the modal of entry into tumor cells, it was divided into passive targeting and active targeting. Active targeting therapy was mainly divided into homologous targeting therapy and targeting agents targeting therapy. The strategy of homologous targeting therapy was to coat MXenes with tumor cell membrane and increased the uptake of MXenes by tumor cells. Targeting agents targeting therapy used targeting agents to specifically bind to the receptors on the surface of tumor cells, subsequently, the precise uptake of MXenes by tumor cells was achieved. Finally, the current challenges and future development trends of MXenes in preparation technology and tumor therapy are discussed.
Polyunsaturated fatty acids (PUFAs) have diverse health-promoting effects, such as potentially protecting in immune, nervous, and cardiovascular systems by targeting a variety of sites, including most ion channels. Voltage-gated potassium channels of the KV7 family and large-conductance Ca2+- and voltage-activated K+ (BKCa) channels are expressed in many tissues, therefor, their physiological importance is evident from the various disorders linked to dysfunctional KV7 channels and BKCa channels. Thus, it is extremely important to learn how potassium channels are regulated by PUFAs. The aim of this review is to provide an overview of the effects of PUFAs on KV7 channels and BKCa channels functions, as well as the mechanisms underlying these effects. In summarizing reported effects of PUFAs on KV7 and BKCa channels mediated currents, we generally conclude that PUFAs increase the current amplitude, meanwhile, differential molecular and biophysical mechanisms are associated with the current increase. In KV7 channels the currents increasement are associated with a shift in the voltage dependence of channel opening and increased maximum conductance in KV7 channels, while in BKCa channels, they are associated with destabilization the pore domain closed conformation. Furthermore, PUFA effects are influence by auxiliary subunits of KV7 and BKCa channels, associate with channels in certain tissues. although findings are conflicting. A better understanding of how PUFAs regulate KV7 and BKCa channels may offer insight into their physiological regulation and may lead to new therapeutic strategies and approaches.
Objective To investigate the genetic polymorphism and structure of 47 autosomal microhaplotypes in the Han population in Changshu, Jiangsu, and to evaluate the forensic efficiencies and forensic parameters. Methods The DNA library of unrelated individual samples was prepared according to MHSeqTyper47 kit manual and sequenced on the MiSeq FGx platform. Microhaplotype genotyping and sequencing depth statistics were processed using MHTyper. The genetic information of samples was then evaluated. The fixation index and genetic distance between the Jiangsu Changshu population and the reference populations in the 1000 genomes project phase 3 (1KG) were calculated, and forensic parameters were evaluated. Results The fixation index and genetic distance between the Han population in Changshu, Jiangsu, and the CHB (Han Chinese in Beijing, China) reference population in 1KG were the lowest. The effective allele number (Ae) of each locus is also the closest between the two populations. The combined matching probability (CMP) of the Changshu Han population is close to the five populations of the East Asian reference super-population in 1KG, which is 1.25×10-36, and the combined probability of exclusion reached 0.999 999 999 964 1. Conclusion This study reported the genetic polymorphism and allele frequency of 47 microhaplotypes in a Han population in Changshu, Jiangsu Province. This information provides a data basis for 47 microhaplotypes in forensic applications. In addition, the polymorphism differences between the 1KG reference population and the Han population in Changshu, Jiangsu were compared, and the genetic structure of 47 microhaplotypes in the Han population in Changshu, Jiangsu was revealed. In general, the reference data of the East Asian super-population in 1KG is more in line with the genetic characteristics of the Han population in Changshu, Jiangsu.
Magnetic cell sorting technology is a highly specific and rapid cell sorting technology using superparamagnetic nanocomposites for cell sorting, which is widely used in immunology, stem cytology, oncology, clinical medicine and other fields. Magnetic cell sorting technology is divided into positive isolation, negative isolation/untouched cell isolation, depletion, multi-step isolation and automated cell separation systems. In this review, we firstly give a brief introduction to the classification and application of magnetic cell sorting technology, then discusses several new techniques and challenges based on magnetic cell sorting in recent years, such as improving the sorting efficiency by improving the structure of magnetic materials and magnetic field structure. The necessity of biological evaluation of magnetic cell sorting products was emphatically analyzed. Through the biological evaluation, the advantages and disadvantages of magnetic cell sorting products can be understood, and the research and development ability could be improved. Therefore, ten biological evaluation technical parameters related to magnetic cell sorting products were proposed: yield, purity, sterility, cytotoxicity, cell morphology, viability, light scattering characteristics of cells, fluorescent antibody labeling ability of cells, cell activation and cell proliferation. The ten biological evaluation technical parameters play an important role in promoting the standardized application of magnetic cell sorting.
Abstract Objective The scale of microalgae farming industry is huge. During farming, it is easy for microalgae to be affected by miscellaneous bacteria and other contaminants. Because of that, periodic test is necessary to ensure the growth of microalgae. Present microscopy imaging and spectral analysis methods have higher requirements for experiment personnel, equipment and sites, for which it is unable to achieve real-time portable detection. Method This paper has developed a microalgae detection system based on deep learning. A microscopy imaging device based on bright field was constructed. With imaged captured from the device, a neural network based on YOLOv3 was trained and deployed on microcomputer, thus realizing real-time portable microalgae detection. This paper has also improved the feature extraction network by introducing cross-region residual connection and attention mechanism and replacing optimizer with Adam optimizer using multistage and multimethod strategy. Results With cross-region residual connection, the mAP value reached 0.92.Compared with manual result, the detection error was 8.49%. Conclusion The system could achieve real-time portable microalgae detection and provide relatively accurate detection result, so it can be applied to periodic test in microalgae farming.
Human eyesight is mainly built up with central vision images received at the macular region. Loss of central vision by frailty and age-related macular degeneration, etc., can rob a person of the ability to read, drive and recognize people’s faces. For these groups of people, it is feasible to project simplified images to the retina regions out of the macula thus utilizing the peripheral vision to partially restore the capacity of visual sensation. In general, people can clearly notice moving objects in the peripheral vision but usually sense a hazy scene when the objects in the sight field are located far from the central region. Due to lack of direct applications, the sensation characteristics in peripheral vision are not fully revealed. In this work, we have systematically investigated the human eyesight properties in the peripheral region with various eccentricities, i.e., the offset angle from the straightforward direction, in the range of 10°-55°. Symbols, numerals, Chinese characters and moving or changing objects with different sizes, combinations of colors and eccentricities, have been tested for healthy college students. Characteristics of visual capacity in terms of reaction time, identification error that obtained from these experiments have shown that peripheral vision could play an important role in recognition of symbols, patterns and texts. The results may offer important clue for practical applications, such as the implantation of artificial optical devices in eyes, or the development of color symbol codes for special communication.
Social behavior is extremely important for the physical and mental health of individuals, their growth and development, and for social development. Social behavioral disorders have become a typical clinical representation of a variety of psychiatric disorders and have serious adverse effects on the development of individuals. The prefrontal cortex, as one of the key areas responsible for social behavior, involves in many advanced brain functions such as social behavior, emotion, and decision-making. The neural activity of prefrontal cortex has a major impact on the performance of social behavior. Numerous studies demonstrate that neurons and glial cells can regulate certain social behaviors by themselves or the interaction which we called neural microcircuits; and the collaboration with other brain regions also regulates different types of social behaviors. The PFC-thalamus projections mainly influence social dominance and social preference; the PFC-amygdala projections play a key role in fear behavior, emotional behavior, social exploration, and social identification; and the PFC-nucleus accumbens projections mainly involve social preference, social memory, social cognition, and spatial-social associative learning. Based on the above neural mechanism, many studies have focused on applying the non-invasive neurostimulation to social deficit-related symptoms, including transcranial magnetic stimulation (TMS), transcranial electrical stimulation (TES) and focused ultrasound stimulation (FUS). Our previous study also investigated that repetitive transcranial magnetic stimulation can improve the social behavior of mice and low-intensity focused ultrasound ameliorated the social avoidance behavior of mice by enhancing neuronal activity in the prefrontal cortex. In this review, we summarize the relationship between neurons, glial cells, brain projection and social behavior in the prefrontal cortex, and systematically show the role of the prefrontal cortex in the regulation of social behavior. We hope our summarization will provide a reference for the neural mechanism and effective treatment of social disorders.
In prokaryotes like Escherichia coli (E. coli), transcription tends to be coupled with translation, which is usually manifested in the mutual regulation of transcription and translation such as transcription polarity, transcription attenuation and synchronization of transcription and translation rates. Indirect coupling and physical coupling are two different models of the coupling. (p)ppGpp, riboswitch and TufA protein participate in the maintenance of indirect coupling. Physical coupling could be divided into those mediated by NusG or RfaH factors and those induced via "collision" under non-factor condition. Transcription or translation in response to independent signals supports the transition among several coupled modes. Coupling is necessary for normal gene expression, and its release will contribute to adverse events such as transcription termination, R-loop formation, conflict between replication and transcription and mRNA cleavage. The related technologies of structural biology have clearly demonstrated the structural details and characteristics of partial coupled expressomes. These technologies, combined with methods like multiomics analysis, will provide deeper insights into the coupling. Significantly, the study of the coupling may bring new ideas for development of the targeted antibiotics.
SHEN Chong-Jie,Morigen.Mechanism of Transcription-translation Coupling in Escherichia coli[J]..Export: BibTexEndNote
Objective: Existing artificial vision devices can be divided into two types: implanted devices and extracorporeal devices, both of which have some disadvantages. The former requires surgical implantation, which may lead to irreversible trauma, while the latter has some defects such as relatively simple instructions, limited application scenarios and relying too much on the judgment of artificial intelligence (AI) to provide enough security. Here we propose a system that has voice interaction and can convert surrounding environment information into tactile commands on head and neck. Compared with existing extracorporeal devices, our device can provide a larger capacity of information and also has advantages such as lower cost, lower risk, suitable for a variety of life and work scenarios. Methods: With the latest remote wireless communication and chip technologies, microelectronic devices, cameras and sensors worn by the user, as well as the huge database and computing power in the cloud, the backend staff can get a full insight into the scenario, environmental parameters and status of the user remotely (for example, across the city) in real time. In the meanwhile, by comparing the cloud database and in-memory database and with the help of AI-assisted recognition and manual analysis, they can quickly develop the most reasonable action plan and send instructions to the user. In addition, the backend staff can provide humanistic care and emotional sustenance through voice dialogs. Results: This study originally proposes the concept of “remote virtual companion” and demonstrates the related hardware and software as well as test results. The system can not only achieve basic guide functions, for example, helping a person with visual impairment to shop in supermarkets, find seats at cafes, walk on the streets, construct complex puzzles, and play cards, but also can meet the demand for fast-paced daily tasks such as cycling. Conclusion: Experimental results show that this “remote virtual companion” is applicable for various scenarios and demands. It can help blind people with their travels, shopping and entertainment, or accompany the elderlies with their trips, wilderness explorations, and travels.
Abstract Objective To construct an analysis process for Identity-By-Descent (IBD) algorithm to predict distant relatives and evaluate the prediction accuracy. Methods 253 family samples were detected by using high-density whole genome SNP chip. IBD algorithm was used to predict the genetic relationship between pairs of individuals, and the prediction accuracy was evaluated. The number of SNPs was randomly reduced to evaluate the effect of SNP numbers on the accuracy of the algorithm prediction. Results Among 1-7th kinship degree, the average confidence interval accuracy of IBD algorithm was 94.72%, and the prediction credibility was 99.77%. The false negative of IBD algorithm was found when kinship degree is 6 or higher. When the number of SNPs decreases, the prediction accuracy will decline to a certain extent. Conclusion The IBD algorithm can accurately predict the genetic relationship within the seventh kinship degree, and it has important application value in population genetics, forensic genealogy inference and other fields.
Abstract Objective Although expression of the TEAD1 protein in preadipocytes has been established, its function remains unclear. In this study, we sought to detect transcripts of TEAD1 in chicken and to examine the effects of this protein on the proliferation, migration, apoptosis, and differentiation of immortalized chicken preadipocyte cell lines (ICP1). Methods The full-length sequence of the TEAD1 gene was cloned and the two transcripts were subjected to bioinformatics analysis. The subcellsular localization of TEAD1 transcripts was determined based indirect immunofluorescence. The effects of TEAD1 transcripts overexpression on the proliferation of ICP1 cells were examined by RT-qPCR, CCK-8, and EdU assays; the effects of TEAD1 transcripts on ICP1 cells migration were examined based on the scratch test; and the effects of TEAD1 transcripts overexpression on ICP1 cells apoptosis were analyzed using apoptosis-Hoechst staining and RT-qPCR. The expression of TEAD1 transcripts in different tissues, cells lines, and ICP1 at different periods of differentiation was analyzed by RT-qPCR. The effects of TEAD1 transcripts overexpression on lipid droplet accumulation and adipogenic-related gene expression in ICP1 cells were analyzed based on Oil Red O and BODIPY staining, RT-qPCR, western blotting, and dual-luciferase reporter gene assays. Finally, the content of triglyceride (TG) in ICP1 cells was measured by overexpression of TEAD1 transcripts. Results The full-length TEAD1 was cloned and two TEAD1 transcripts were identified. The TEAD1-V1 protein was found to be localized primarily in the cell nucleus, whereas the TEAD1-V2 protein is localized in the cell cytoplasm and nucleus. The overexpression of both TEAD1-V1 and TEAD1-V2 significantly inhibited the proliferation of ICP1 cells. Whereas the overexpression of TEAD1-V1 promoted ICP1 cells migration, the overexpression of TEAD1-V2 had no significant effects on ICP1 migration; and the overexpression of both TEAD1-V1 and TEAD1-V2 significantly promoted the apoptosis of ICP1 cells. We established that the different transcripts of TEAD1 have similar functions in different tissues and cells lines. During induced preadipocyte differentiation, the expression of these genes initially declined, although subsequently increased. Overexpression of TEAD1-V1 promoted a significant reduction in lipid droplet formation and inhibited C/EBPα expression during the differentiation of ICP1 cells (P < 0.05). However, the overexpression of TEAD1-V2 had no significant effect on lipid droplet accumulation or the expression of adipogenic-related proteins (P > 0.05). Overexpression of TEAD1-V1 significantly decreased triglyceride content in ICP1 cells (P <0.05), while overexpression of TEAD1-V2 had no effect on triglyceride content in ICP1 cells (P > 0.05). Conclusion In this study, for the first time, identified two TEAD1 transcripts. Overexpressed transcripts TEAD1-V1 and TEAD1-V2 both inhibited the proliferation of chicken preadipocytes and promoted apoptosis of chicken preadipocytes. TEAD1-V1 inhibited the differentiation of proadipocytes and promoted the migration of proadipocytes, while TEAD1-V2 had no effect on the differentiation and migration of proadipocytes.
Objective In recent years, accumulating evidence indicated that epigenetic alterations may be used as the potential biomarkers to detect toxicity caused by MNPs. Thus, the effects of metal nanoparticles (MNPs) exposure on the phosphorylation of histone H3 at serine 10 (p-H3S10) were clarified, and the changes of whole gene expression in cells exposed to typical MNPs were explored in this study to provide a theoretical basis for screening the biomarkers of early toxicity of MNPs. Methods The effects of ten kinds of MNPs exposure on the p-H3S10 were evaluated using western blotting and flow cytometry. In addition, the effects of copper oxide (CuO) NPs, which is a typical MNPs, on the whole gene expression of cells were explored at the transcriptional level by RNA sequencing technology. Results All the tested MNPs except nickel oxide NPs induced p-H3S10 to different degrees. Among, upregulation of p-H3S10 was observed at immediately after CuO-NPs and zinc oxide NPs treatment, and continued for 10 h. Moreover, p-H3S10 increased slightly after aluminium oxide NPs and antimony (III) oxide NPs treatment, and reached the highest point at 0.5 h. After that, p-H3S10 began to decrease and obtained the lowest value at 2 h. However, p-H3S10 began to rise again after treatment over 2 h until the final observation time point. In addition, p-H3S10 was temporarily induced after treatment with iron (II,III) oxide NPs, silica NPs, cobalt (II,III) oxide NPs, chromium (III) oxide NPs or titanium dioxide NPs, but rapidly ceased. Further analysis indicated that MNP-induced p-H3S10 was highly related to the cellular uptake of MNPs, and the sustained release of ions from MNPs inside cells might generate p-H3S10 for an extended period after the initial uptake of MNPs. In addition, RNA sequencing analysis revealed that CuO-NPs treatment caused significant differential expression of 275 genes (P≤0.05), 185 of which were upregulated and 90 of which were downregulated. Gene ontology (GO) analysis showed that the majority of differentially expressed genes (DEGs) were involved in regulation of signaling, transcription factor activity and kinase activity. Through analyzing enriched GO pathways related to stress, two prominent membrane-activated cascades emerged: the mitogen-activated protein kinase (MAPK) cascade, and Janus kinase/signal transducers and activators of transcription (JAK/STAT) cascade. Genetic markers specific to extracellular signal-regulated kinases ERK1/ERK2 regulation, stress-activated MAPK cascades, and JAK/STAT cascade were also significantly altered after CuO-NPs treatment. It was observed/found that a large number of genes related to MAPK tyrosine/serine/threonine phosphatase activity were differentially expressed after/due to CuO-NPs treatment. Kyoto Encyclopedia of Genes and Genomes analysis showed strong associations between the DEGs and signal transduction, signaling molecules and interactions, immune and endocrine systems. Moreover, several DEGs were also correlated with transport, catabolism, cell growth and cell death. MAPK cascades were also significantly upregulated after CuO-NPs exposure. Conclusion These results indicated that early induction of p-H3S10 by MNPs is highly related to the cellular uptake of MNPs, and the persistent release of ions from MNPs inside cells might generate p-H3S10 for a long time after the initial uptake of MNPs. Taken together, the p-H3S10 has potential as a suitable candidate biomarker for evaluating the toxicity of MNPs.
Crossmodal transfer is the ability to apply the knowledge acquired in one sensory modality to another. Researches on crossmodal transfer investigate how the brain represents information from different sensory modalities, and provide new insights to improve cognitive processing efficiency and reduce repeated learning. To clarify the characteristics and mechanism of crossmodal transfer, this article first introduced the crossmodal transfer effect in different fields of research, such as object recognition, category learning, and time perception. After that, the theoretical research on the representation type of crossmodal transfer were reviewed, mainly including multisensory theory and multisensory mental imagery theory as well as the supportive and opposite findings. The research progress on the neural mechanism of crossmodal transfer using ERP and fMRI techniques were introduced, mainly including metamodal theory, and multisensory reverse hierarchy theory as well as the supportive and opposite findings. The objective and subjective factors which influence crossmodal transfer effect were sorted out, in which we suggested that the modality dominance phenomenon supports the metamodal theory, while the influence of some other factors such as sensory experience, age, setting of learning tasks and stimulus features supports theories such as the multisensory hypothesis. Finally, we described the potential applications of the current research findings on crossmodal transfer and pointed out future research questions in this field.
Manganese superoxide dismutase catalyzes the dismutation of two molecules of superoxide to one molecule of oxygen and one molecule of hydrogen peroxide. The oxidation of superoxide anion to oxygen by Mn3+SOD proceeds at a rate close to diffusion. The reduction of superoxide anion to hydrogen peroxide by Mn2+SOD can be progressed parallelly in either a fast or a slow cycle pathway. In the slow cycle pathway, Mn2+SOD forms a product inhibitory complex with superoxide anion, which is protonated and then slowly releases hydrogen peroxide out. In the fast cycle pathway, superoxide anion is directly converted into product hydrogen peroxide by Mn2+SOD, which facilitates the revival and turnover of the enzyme. We proposed for the first time that temperature is a key factor that regulates MnSOD into the slow- or fast-cycle catalytic pathway. As the temperature increases in the physiological temperature range, the slow cycle becomes the mainstream of the whole catalytic reaction, so the increasing temperature in the physiological range inhibits the activity of the enzyme. The biphasic enzymatic kinetic properties of manganese superoxide dismutase can be rationalized by a temperature-dependent coordination model of the conserved active center of the enzyme. When the temperature decreases, a water molecule (or OH-) is close to Mn or even coordinates Mn, which can interfere with the formation of product inhibition. So, the enzymatic reaction occurs mainly in the fast cycle pathway at a lower temperature. Finally, we describe the regulation of the enzyme by several chemical modification modes, indicating that manganese superoxide dismutase is rapidly regulated in many patterns (allosteric regulation and chemical modification). These regulatory modulations can rapidly and directly change the activation of the enzyme, and then regulate the balance and fluxes of superoxide anion and hydrogen peroxide in cells. We try to provide a new theory to reveal the physiological role of manganese superoxide dismutase and reactive oxygen species.
Zhangxu.The Catalytic Principle and Activity Modulation of Manganese Superoxide Dismutase[J]..Export: BibTexEndNote
Reducing the consumption of attentional resources and improving human performance in dynamic visual sustained attention tasks is a key issue in sustained attention research. The Multiple Object Tracking (MOT) task is a widely used paradigm for studying individual sustained attention. In a classic multiple object tracking (MOT) paradigm, observers need to maintain their attention on specific targets among a set of distractors and track their movement. To further utilize attentional resources and improve tracking performance, researchers have proposed studying the additivity problem of grouping effects in attention tracking. Grouping effects during MOT is the phenomenon that moving items can be perceived into larger moving units based on featural cues of themselves or task requirements. This article reviewed previous studies about attention resources, classification, additivity, and neural mechanisms of grouping effects in MOT. Based on previous research, we concluded that grouping effects in MOT can be classified into three categories, i.e., spatiotemporal-based grouping, object-based grouping, and feature-based grouping, according to different grouping cues (spatiotemporal continuity, global perception and organization of objects, and surface featural similarity). Grouping based on multiple cues will produce greater effects compared with one cue, this is the additive effect. The study of additivity is important for understanding the cognitive mechanisms of different grouping effects, the attentional mechanisms and resource allocation in individual dynamic visual tracking. This study summarized previous behavioral and neuroimaging researches, systematically explored the non-additivity based on different surface features and the additivity based on surface features and specific spatiotemporal features. Exploring the mechanism of additivity effects provides us with new insight into understanding grouping effects. For future studies, researchers need to thoroughly investigate the neural mechanisms of different kinds of groupings. This can not only provide explanations for the additivity of groupings but also provide substantial evidence for the classification of groupings.
WANG CHUNDI,LI SHUTING.Grouping Effects and its Additivity in Multiple Object Tracking[J]..Export: BibTexEndNote
Transient receptor potential melastatin 7 (TRPM7), a member of the TRPM subfamily, is a ubiquitously expressed bifunctional transmembrane protein with a channel domain fused to an active kinase domain. As a non-selective cation channel, TRPM7 is permeable to Ca2+, Mg2+, Zn2+, Na+, K+, and other trace metals. As a α-kinase, TRPM7 can autophosphorylate its serine and threonine residues, or phosphorylate endogenously targeted substrates such as myosin II. Through the joint action of the two domains, TRPM7 participates in various physiological processes such as Mg2+ homeostasis regulation, cell proliferation, differentiation, adhesion and migration, and ultimately affects cell differentiation and embryonic development. Dysfunction of the TRPM7 has been associated with multiple neurodegenerative diseases, tissue fibrosis, ischemic injury as well as the occurrence and development of tumors. Genetic or pharmacological deficit of the TRPM7 relieves ischemic neuronal injury and inhibits the proliferation and migration of tumors, while up-regulating or restoring TRPM7 decreases blood pressure, maintains normal embryonic development and may be an effective strategy to treat the neurodegenerative disorders. However, whether TRPM7 is a promising target for the development of clinical drugs remains elusive. Nowadays, several small molecules display activation or inhibitory activities on the TRPM7 channel, and have been successfully used to uncover new cellular roles of TRPM7 in physiological and pathological conditions. Nonetheless, selective and potent TRPM7 modulators are limited. This review summarizes the research progress on the physiological and pathological functions of TRPM7 and its small-molecule modulators, which may provide new therapeutic strategies for TRPM7-related diseases and new directions for the development of novel TRPM7 regulators.
Botulinum toxin type A (BTX-A) induces a reversible muscle paralysis at the injection site. There is evidence that BTX-A injection in specific facial muscles affects emotional experience and the processing of emotional stimuli (e.g., facial expressions, emotional language, and videos). Neuroscience research showed that BTX-A injection could attenuate amygdala activity, and could affect the neurocognitive function of the reward system and other cerebral cortex as well. These findings can be interpreted by facial feedback hypothesis and social feedback hypothesis from the individual and social perspectives respectively. For subjects who received the injection, BTX-A reduces feedback from facial muscles thus impairing emotional experience and processing. According to this hypothesis, proprioceptive signals from facial muscles are conducted to the mesencephalic trigeminal nucleus and locus coeruleus, the latter of which sends direct projections to the thalamus, basal ganglia, and cerebral cortex related to motor, cognition, and emotion. In interpersonal communication, the observer’s emotional experience becomes similar to the subject who has received BTX-A injection through facial mimicry, and the subject’s emotional experience is also affected by the observer in turn. The mirror neuron system plays an important role in the process. Based on the existing researches, this review proposed an integrated model to explain the cognitive and neural mechanisms of how BTX-A injection affects emotional processing, which deepens the neural basis of facial feedback and social feedback for expression recognition and emotion processing. The model illustrates the roles of facial feedback and social feedback respectively as ‘signal resource’ and ‘amplifier’ of emotional processing caused by BTX-A injection, and the relationship between them. Specifically, the changes in muscles induced by facial mimicry causing emotional synchronization in social feedback process is in line with facial feedback process. The interaction of the two emotional processes could also cause multiple overlapping effects, which exist in both individual emotional processes and interpersonal interactions. Future studies should expand the aspects and levels of emotional processing, such as focusing on subliminal emotion processing and emotion regulation; further explore the mechanisms of how BTX-A injection affects emotional processing using neuroimaging technologies; improve the research paradigms to study the causal relationship between facial feedback and emotional processing; explore the mechanisms and application of BTX-A in the treatment of mental illness like depression; compare the effects of BTX-A injection and other invasive facial procedures on emotional processing. Further research will not only improve the understanding of cognitive and neural mechanisms underlying emotion but also have potential implications in mental health and medical cosmetology.
MIAO Xiao-Fan,BI Yi-Fan,LIU Ye.The Effect of Botulinum Toxin Type A Injection on Emotional Processing: The Cognitive and Neural Mechanisms[J]..Export: BibTexEndNote
Microorganisms can form biofilms, complex, heterogeneous, multicellular communities that adhere to surfaces. Biofilm formation on the surface of structures in water will accelerate structures' corrosion, seriously affect their service efficiency and life, and significantly impact the growth of animals, plants, and human life. Hence, clarifying the mechanism of biofilm formation contributes to developing new strategies to control biofilm formation on surface and then reduce infections, biofouling, and contaminations. Biofilm-targeting strategies include the regulation of established biofilms or the modulation of single-cell attachment. In most studies, physicochemical mechanism is frequently applied to explain the initial bacterial adhesion phenomena but rarely to explain other stages of biofilm formation. This review presents a five-step comprehensive description of the physicochemical process from film formation to biofilm maturation: (1) period of film formation; (2) period of bacterial adhesion; (3) period of extracellular-polymeric-substances (EPSs) membrane formation; (4) period of regulating biofilm by quorum-sensing (QS); (5) period of biofilm maturation. We first clarify how the film formed by compound molecules affects the surface's physicochemical properties and initial adhesion, summarizing many factors that affect bacterial adhesion. We then review the types of EPSs and signal molecules secreted by bacteria after irreversible adhesion, as well as their role and QS mechanism in biofilm maturation. Finally, we discuss how bacteria or microcolonies separate from the mature biofilm by physicochemical action and summarize the morphology and adhesion characterization methods after the biofilm matures. This review redefines the role of physicochemical in the whole process of biofilm formation and provides a theoretical basis for the prevention, removal, and utilization of biofilm and other related research fields.
Polycystin-2 (PC2, or TRPP2, PKD2) is one of the two major protein types responsible for the underlying etiology of the world"s most prevalent monogenic autosomal dominant polycystic kidney disease (ADPKD). As a transient receptor potential channel (TRP) protein, PC2 can self-assemble into homotetrameric ion channels and form heterologous receptor-ion channel complexes with other proteins,which plays a key role in Ca2+ signaling. PC2 exists on specific cell membranes such as endoplasmic reticulum, primary cilia and plasma membrane, and act in the regulation of mechanosensation, cell polarity, cell proliferation and apoptosis. In addition to its function as an ion channel where cations permeat, PC2 interacts with many other channels and acts as their regulator, eventually further affecting intracellular signaling and causing cystic cells to change from their normal absorption and quiescence to pathological secretion and proliferation when it is absent. PC2 also locates in specific subcellulars and assembles chaperone to form polycystic protein complexes, which are act in a variety of cell differentiation, proliferation, survival and apoptosis-related signaling pathways, and are critical in systemic physiology, especially in ADPKD. In this review , we describe the structure of PC2 channels, and its biophysical and physiological properties as a modulator of cation channels and intracellular calcium channels, and the mechanisms by which dysregulated channel activity contributes to disease, also highlighting emphasize the complexity of PC2 involved in signal transduction in ADPKD.
Lipid metabolism is one of the three major metabolisms in the human body. Lipid metabolism is usually in a balanced state under the regulation of hormones and other signaling factors. When the homeostasis is disrupted, the level of triglyceride (TG) and cholesterol in the blood changes, eventually causing atherosclerosis (AS), obesity and other lipid dysfunction diseases. Long non-coding RNA (lncRNA) is a group of RNAs that do not have the ability to code proteins with more than 200 nucleotides in length. Recent studies have found that lncRNAs are closely related to the regulation of metabolism, inflammation, immune system, and vascular function. A large body of research suggests that lncRNAs are involved in the regulation of lipid metabolism and thus are expected to be potential therapeutic targets for some lipid metabolic diseases.
Sulforaphane is a naturally occurring active substance derived from cruciferous vegetables with potent antioxidant and anticancer properties. Researches have shown that sulforaphane has good bioavailability and can be absorbed by the small intestine through passive transport, followed by excretion in the form of urine via the hydrophobic acid pathway. In addition, since sulforaphane is easy to be absorbed and metabolized, wrapping sulforaphane with nanomaterials can improve its bioavailability and stability, prolong its action time in human body, and better utilize its therapeutic effect. In terms of mechanism of action, sulforaphane can activate Nrf2 and HSF1 signaling pathways, induce the expression of phase II detoxification enzymes HO-1, NADPH, GST and HSP, thus regulating the concentration of oxidative stress ROS in vivo; inhibit NF-κB signaling pathway, thus suppressing the expression of inflammatory factors TNF-α, IL-1 and IL-6; regulate epigenetic modifications, thus inhibiting HDAC and DNMT, and increasing the concentration of histone H3 and H4; by regulating the expression levels of the above factors, sulforaphane can affect the occurrence and development of cancer, neurodegenerative diseases and other diseases. In recent years, several phase I/II clinical trials have shown that sulforaphane has good drug-generating properties. For example, researchers have found that patients with ASD and skin cancer have not shown any health problems and their corresponding functional problems have improved greatly after long-term use of sulforaphane. This suggests that in the future sulforaphane has a very high medicinal potential for the treatment of cancer and neurodegenerative diseases. In this paper, we review the pharmacokinetics, target of action and safety of sulforaphane and its research progress in tumor and neurodegenerative diseases to provide a reference for the future application of sulforaphane in the treatment of tumor and neurodegenerative diseases.
Objective Many studies have shown that a high-sugar diet can do a lot of harm to the health of teenagers. As one of the important windows for human to perceive the world, the visual system plays an important role in teenagers' perception ability. Many studies have confirmed that high-sugar diet can damage visual function, but the current research on the effects of high-sugar diet on visual function mainly focuses on the front of the visual pathway, focusing on the eye system and the optic ganglion, the posterior of the visual pathway, such as the central cortex, has not been reported. In order to understand the effect of high sugar diet on visual function, the effect of high sugar diet on central cortex was studied.
Methods In this study, we used the behavioral paradigm of GO/NO-GO orientation discrimination task and in vivo multi-channel electrophysiological techniques to explore the effects of high-sugar diet on the primary visual cortex of young mice.
Results Behavioral results showed that young mice that had undergone two months of high-sugar diet had a reduced ability to distinguish orientation. The response characteristics of single neurons in the primary visual cortex (V1) were analyzed by electrophysiological techniques. It was found that the ability of orientation tuning of single neurons in the primary visual cortex decreased in mice fed with high-sugar diet, the response variability of neurons increased and the signal-to-noise ratio (SNR) decreased significantly. We further analyzed the changes of signal-to-noise ratio (SNR) and response variability at population level. The results showed that SNR decreased significantly and response variability increased significantly at population level. The results of neuron correlation analysis showed that the noise correlation of primary visual cortex in the high-sugar diet group was significantly up-regulated. In conclusion, these results suggest that a high-sugar diet impairs the ability of young mice to discriminate orientation by affecting the receptive field characteristics of individual neurons in the primary visual cortex, as well as the information processing capacity of neuronal populations.
XU Long-Ling.Functional impairment of the primary visual cortex of young mice by high-sugar diet and its mechanism[J]..Export: BibTexEndNote
Abstract Objective Based on bioelectrical impedance Spectroscopy, we propose a label-free method for real-time detection of biological cell activity. The method determines whether the cells are active or not based on the differences in electrical properties of the cells at different concentrations, physiological and pathological states, in order to assist physicians to quickly and precisely locate the scalded tissues in patients and achieve effective excision during clinical surgery. Methods Active zebrafish embryonic stem cells were used to simulate human scalded tissues, and bioimpedance spectroscopy was used to identify the physiological state of the cellular tissues. Results There were significant differences in the impedance amplitude changes of the cells in different states, from which it could be found that the impedance amplitude of the active cells at the same concentration was on average 17.25% higher than that of the dead cells, and the relaxation frequency of the active cells occurred 25% earlier than that of the dead cells. Conclusion The experimental data showed that the bioimpedance spectroscopy method can effectively distinguish two types of physiological states of embryonic cells; from the clustering region, it can be seen that the BIS assay has obvious ability to distinguish cell activity and concentration, which theoretically can quickly assist physicians to complete the detection of scalded tissues of patients.
Human milk oligosaccharides (HMOs) present in breast milk are a family of highly complex oligosaccharides that play a positive role in the intestinal flora, immune barrier, and brain development of infants. Due to the complex matrix in breast milk, the variety of oligosaccharides, the span of abundance, and the presence of many isomers, the detection of breast milk is faced with many challenges. A variety of techniques have been used for the analysis of human milk oligosaccharides and over 200 HMOs have been identified. Liquid chromatography and capillary electrophoresis have been effective in separating human milk oligosaccharides. Nuclear magnetic resonance spectroscopy, mass spectrometry and infrared multiphoton dissociation spectroscopy have promoted the comprehensive structural resolution of HMOs. This paper reviews the various techniques used to achieve high sensitivity and specificity for the analysis of HMOs and compares the advantages and disadvantages of the different techniques. This paper also focuses on the breakthroughs in mass spectrometry and the combination of different techniques to facilitate the analysis and determination of HMOs, providing a comprehensive technical support to explore the structure-function relationship of oligosaccharides and to gain a deeper understanding of the biological functions of HMOs.
The p53 protein is an essential tumor suppressor in the human body that plays a critical role in preventing tumor formation by controlling cell cycle arrest and promoting apoptosis. Mutations in the p53 gene are frequently observed in more than 50% of tumor tissues and lead to the generation of mutant p53 proteins, which not only have a dominant-negative effect (DN) that hinders the function of wild-type p53 protein but also have gain-of-function (GOF) effects that stimulate tumor development by regulating cell metabolism, invasion, migration, and other processes. Therefore, mutant p53 protein has become a specific drug target for cancer therapy. However, the lack of a drug-binding pocket and smooth surface of mutant p53 proteins have made them undruggable targets for a long time. In recent years, with the development of high-throughput screening technology and an enhanced understanding of the structure and conformational changes exhibited by mutant p53 proteins, a multitude of small molecule compounds directed against mutant p53 protein have been identified, exhibiting substantial in vitro anti-tumor efficacy. Moreover, some of these compounds have entered clinical trials. This review summarized the direct and indirect strategies for the treatment of cancers targeting mutant p53, with a primary focus on the mechanisms of action of small molecule compounds that reactivate mutant p53 protein or degrade mutant p53 protein. The aim is to provide assistance for the development of innovative drugs targeting mutant p53 protein in the future.
Objective The high density SNP genotype data were obtained by whole genome sequencing (WGS), the accuracy of genotype was evaluated, and this study is intended to establish the method of using whole genome sequencing data for SNP kinship relationship prediction. Method The samples were sequenced at a depth of 30× through the MGISEQ-200RS sequencing platform, and 645199 autosomal SNP in the Wegene GSA DNA microarray were extracted from the sequencing data. After quality control and filtering, the prediction relationship was calculated and predicted by IBS/IBD algorithm, and the ancestry of the samples was analyzed. Results The coincidence rate between SNP genotype extracted from sequencing data and Wegene GSA genotype is more than 99.62%.The SNP genotype obtained by sequencing can predict kinship from level 1 to level 4 by using IBS algorithm, and confidence interval accuracy of level 4 kinship prediction is 100%. Using IBD algorithm, the confidence interval accuracy of level 1 to 7 kinship prediction is 100%. The pedigree inference ability of SNP obtained from high-depth whole genome sequence data is not significantly different from that of DNA microarray prediction.At the same time, the use of whole genome sequencing data for ancestry inference is consistent with the survey results. Conclusion The whole genome resequencing technique can be applied to SNP genealogy inference to provide clues for case detection.
RAS-related signaling system plays an important role in the occurrence and development of colorectal cancer, which is closely related to the proliferation, metastatic potential, and apoptosis of colorectal cancer cells. However, treating this type of cancer with a single medicine, either targeted therapies or chemotherapies, is not always the best option. In recent years, RAS-related signaling pathway inhibitors have been utilized in conjunction with other medications with promising outcomes in clinical trials and preclinical investigations. When used in concert with other anti-cancer drugs, EGFR inhibitors, VEGF inhibitors, RAS direct inhibitors, MEK inhibitors, and RAF inhibitors have shown particularly impressive performance. In terms of clinical value, combining cetuximab with chemotherapy regimens, EGFR inhibitors with chemotherapy regimens, and EGFR inhibitors with other anti-cancer drugs dramatically enhanced important indicators in patients with colorectal cancer who had wild-type RAS. However, treatment options for patients with RAS-mutant colorectal cancer have been less favorable, and in this context, anti-angiogenic and anti-EGFR agents and immune checkpoint inhibitors have been approved as second-line treatment options. In preclinical studies, inhibitors that directly target RAS have been shown to be effective in combination with other drugs, and other treatment options have also shown good results, giving patients with colorectal cancer unlimited hope. This review focuses on the relationship between RAS-related signaling pathways and colorectal cancer, combination tactics in clinical trials and preclinical studies, and research on drug resistance mechanisms linked with composition administration in order to lay the foundation?for future clinical multidrug therapy strategies.
Objective The Cochlear Microphonic (CM) signal produced by the bat cochlear outer auditory hair cells contains information related to the movement of the cochlear basilar membrane. The aim of this study was to investigate the mechanism of bat cochlear nerve influence on echolocation by analyzing the relationship between frequency modulation (FM) bat CM signals and their received acoustic frequencies. Methods The CM signals of FM bats (Eptesicus and Pipistrellus) were recorded and analyzed in response to pure acoustic (Tone Burst) stimulation by placing a set of metal electrodes in the ventral cochlear nucleus. Results Two different species of FM bats (Eptesicus and Pipistrellus) exhibited CM mean frequency response curves during high sound pressure stimulation with a distinct concavity in the narrower specific frequency band vocalization. For Eptesicus, the CM rms frequency response curves showed significant troughs on both sides of the terminal frequency (TF) of the first and second harmonics; moreover, these troughs were repeated at 15 kHz intervals from 15 kHz onwards; for Pipistrellus, the CM rms frequency response curves showed significant troughs only on both sides of the first harmonic. The valleys are evident on both sides. Conclusions The relationship between the inhibition exhibited by the CM signal and the FM bat's first and second harmonic TF reflects the fact that the cochlear nerve produces inhibition for specific frequencies, and this inhibition helps the bat to extract target localization information modulated to the vicinity of the TF.
Brain source localization technology aims to identify the source of neural activity in the brain through the EEG and Meg signals on the scalp surface, which is the basis of studying the neural activity, cognitive process, and pathological function of the cerebral cortex. Its millisecond time resolution can effectively make up for the shortcomings of fMRI in low time resolution. However, the accuracy of brain source localization faces great challenges due to the inadequacy of the inverse problem in theory and the errors caused by different recording methods, the number of electrodes, and head model construction in practice. This also limits the practical application of brain source localization methods in neuroscience and psychology research, clinical diagnosis, and treatment. Therefore, the accuracy evaluation of the theoretical analysis and practical operation is very important in the practical application of brain source localization technology. To solve the above problems, this paper introduces the existing brain source localization methods and analyzes the accuracy evaluation methods of brain source localization technology and its practical application in basic research and clinical diagnosis and treatment. Specifically, in the theoretical analysis, this paper summarizes the evaluation methods based on spatial resolution, point diffusion, and crosstalk function on the degree of source overlap among different brain source localization methods and the influence of other sources on target sources. In practice, this paper introduces the effects of recording mode, electrode number, density, and head volumetric conduction model on source positioning accuracy. In addition, the application of brain source localization technology in time-frequency analysis and connectivity analysis, as well as its clinical application in epilepsy, attention deficit, hyperactivity disorder, and other brain abnormalities or diseases are further introduced in this paper.
Colorectal cancer (CRC) is the second leading cause of cancer death, and patients tend to be more younger. Although chemotherapy, immunotherapy and targeted therapy have made progress, the toxicity, drug resistance and high price of drugs have seriously affected the comprehensive treatment effect of CRC. Therefore, seeking new, more sensitive and effective drugs and drug targets is the current research focus. Ferroptosis, a recently discovered regulation mode of cell death, which is closely related to cancer drug resistance. Activating ferroptosis has become a potential strategy to overcome the drug resistance mechanism of traditional cancer treatment. The development and application of drugs that induce ferroptosis is expected to become an effective means to treat CRC. This review describes the latest progress in the research of metabolic pathway drugs related to ferroptosis in CRC, so as to comprehensively understand the specific mechanism of ferroptosis based drugs in CRC, fully tap its therapeutic potential, and provide new methods for the diagnosis and treatment of CRC and the solution of drug resistance.
Pyroptosis, a type of regulated cell death, have been shown to be immunogenic in quite a few studies. Pyroptosis has been observed since 1986 and was found to be mediated by GSDM family proteins until recently. Gasdermines (GSDMs) are a group of intracellular proteins that mediates cell pyroptosis. Although GSDMs are expressed in inactive forms, some proteolytic enzymes can activate them. The N-terminus of activated GSDMs perforate the plasma membrane, resulting in cell lysis. Pyroptosis is a double-edged sword that is closely related to the tumor immune microenvironment. Pro-inflammatory molecules and DAMPs will be quickly and effectively released into the microenvironment from the pyroptotic cells, and trigger inflammation and immune response, while these immune responses are not always positive. Inductions of pyroptotic cell death have been shown to promote anti-tumor immunity and improve the efficacy of immune checkpoint inhibitors, which involves the cytotoxic effects of effector T lymphocytes, or reprograming of the tumor microenvironment to an immunostimulatory state. In this review, we not only summarize the mechanisms of different types of pyroptosis and the key molecules that promote inflammatory and immune response during pyroptosis, but also compare its common features with apoptosis. In addition, we discuss the potential positive and negative factors to cancer therapy during pyroptosis. Although our understanding of pyroptosis in cancer is growing, many mechanisms remain unclear - how pyroptosis activates the immune system, how pyroptosis is regulated, and how pyroptosis can be harnessed therapeutically to improve cancer immunotherapy or to reduce therapy related toxicity. We hope this review will help further understanding of the role of pyroptosis in tumor microenvironment and cancer immune therapy, promoting the improvement of cancer therapy strategies.
Purpose: Aging is an increasingly serious social problem. The cognitive function of the elderly, such as attention, shows a significant decline. Investigating the deficits of visual attention regulatory network caused by aging will further our understanding of the neural mechanism of cognition declines of the elderly, and providing us the theoretical basis to find potential intervention methods. Methods: In the study, we used a classical two-target attention task. Subjects were asked to keep their gaze on the central fixation cross. a pair of spots appeared separately located on left and right 13.5° from the cross. After 800-1200 ms fixation, one of two spots randomly changed its form or both remained unchanged. We recorded neural activity of young adults and old adults during the attention task using electroencephalogram (EEG). Results: Through comparing the differences of EEG activity under visual stimuli changed and unchanged conditions, we found that neural activity of channels in frontal, parietal and temporal areas of young adults significantly changed with the change of stimuli, while neural activity of old adults didn’t follow the change of stimuli. Conclusion: These results demonstrated that brain network of the elderly could not effectively react to the change of external visual information load in the attention task. Aging is accompanied by the functional decline of the visual attention regulatory network. Besides, decline of this brain network also showed sex difference. Our research provided new evidence for the decline of visual attention regulatory network of the elderly.
Mitochondria are responsible for cellular aerobic respiratory function. The nervous system is a huge energy consuming tissue of the body and highly depends on the structure and functional stability of mitochondria. Multiple research shows that mitochondrial abnormality is an essential reason for the occurrence and development of various neurological diseases. The mitochondria-targeted treatment for neurological disorders has become a frontier and hot spot. This review focuses on the research progress of mitochondrial transplantation in the treatment of various neurological diseases, mainly discussing its cellular and molecular mechanisms and the challenges which it faces, in order to provide clues and basis for clinical development of new therapeutic methods. There are 11 neurological models that have been reported to be effective for mitochondrial transplantation: middle cerebral artery occlusion cerebral ischemia reperfusion model, focal cerebral ischemia model, traumatic brain injury model, schizophrenia model, depression model, diabetic cognitive dysfunction model, Parkinson's disease model, aging model, sepsis model, nerve compression model and spinal cord injury model. According to the source of transplanted mitochondria, the mitochondrial transplantation methods used in the above studies can be divided into direct transplantation and indirect transplantation. Direct transplantation refers to the transfer of mitochondria themselves, while indirect transplantation refers to the transfer of other carriers carrying mitochondria. There are three sources of mitochondria for direct transplantation: cell lines, human umbilical cord mesenchymal stem cells, and allografts. Mitochondria are derived from skeletal muscle, placenta, liver, brain and platelets. There are six methods of mitochondrial transplantation into the body: arterial injection, intraventricular injection, intravenous injection, vitreous injection, epineural injection, and spinal injection. The number of injections varies from a single injection to multiple injections in a row. The amount of mitochondria injected varied greatly. The duration of therapeutic or ameliorative effects after mitochondrial transplantation varied widely in reports. The effect after transplantation was to reduce the degree of disease in the animals. Biological mechanisms of mitochondrial transplantation consists of tunneling nanotubes (TNTs) and extracellular vesicles (EVs). And EVs are further classified into three categories according to their diameter size, including exosomes, microvesicles, and apoptotic body. The key issues to be addressed in mitochondrial transplantation for neurological diseases include: source of transplanted mitochondrial; pathway of mitochondrial transplantation; storage of the mitochondria; immune response. Mitochondrial transplantation has achieved great results in the treatment of neurological diseases in less than a decade, and it is considered to have great clinical value. This review predicts that future studies will gradually reveal mitochondrial quality control strategies and their molecular and cellular mechanisms in mitochondrial transplantation, and will form clinical standardized diagnosis and treatment plans for mitochondrial transplantation.
Variations in human vital sign will lead to changes of blood composition and quality. As for a basic screening project to assess human health, blood analysis has been extensively applied to health monitoring, disease diagnosis and rehabilitation evaluation. With the rapid development of economy and the continuous improvement of national living standards, human’s awareness of life and health is increasingly enhanced, which greatly promotes the evolution of sample, fast and sensitive disease screening technology. At present, developing the rapid blood analysis device has become a hot spot in the medical field for disease screening. There are many kinds of existing studies, but the whole blood analysis has not been systematically sorted and classified. This study systematically reviews the main development research and the latest progress of whole blood analysis. Starting form two aspects of direct whole blood analysis and indirect whole blood analysis, the current equipment methods and applications has been clarified based on direct whole blood analysis, the core processing technology and detection technology has been concluded based on indirect whole blood analysis. Finally, the problems of non-portability, low efficiency and high price for the whole blood analysis device at the present stage has been discussed, and the prospect of whole blood analysis in the direction of integration, intellectualization and low-cost has been summarized and prospected, which provided new ideas for the future research direction of rapid blood analysis.
Chemical modifications of RNA bases play essential roles in finetuning the functions of the modified RNA species. The m6A modification is one of the most prevalent RNA modifications in nature with important functions in RNA stability, pre-mRNA splicing, translational regulations and likely others. m6A modifications in eukaryotes are believed to be mainly carried out by two related methyltransferases, METTL3 and METTL16 based on mammalian nomenclature. METTL16, similar to METTL3, has a large variety of RNA substrates, including pre-mRNA, rRNA, snRNA and lncRNA. Therefore, a unifying molecular function seems farfetched for the METTL16-installed m6A modification. In addition, METTL16 carries out important function in translational regulation independent of its methyltransferase activity, adding another layer of functional complexity to this highly conserved enzyme. In this review, we summarize the domain architecture of METTL16 and homologous proteins, indicating the conserved functional domains as well as the mammalian specific VCR domain suggestive of additional function of the higher enzymes. We summarize the confirmed METTL16-methylated RNA substrates as the pre-mRNA for SAM synthetase (MAT) in men and worms, and the U6 small nuclear RNA (snRNA) in yeast, plants, worms and men. Although the role of m6A modification in regulating SAM levels by alternative splicing might represent a case of convergent evolution, this proposition lacks support from plant studies of METTL16. The lack of m6A modification on U6 snRNA, an essential component of the spliceosome, has been identified in genome-wide studies as the cause for the splicing defects of specific introns in yeast and plants. How much of this function of U6 modification is conserved remains unclear. Mammalian METTL16 has been shown to carry out methylation-independent function by interacting with the machinery for protein synthesis. In addition, METTL16 was originally identified as the interacting protein of the triple-helix forming MALAT1, a long non-coding RNA highly expressed in certain tumors. However, whether MALAT1 is a methylation substrate of METTL16 or what underlies the biological significance of the METTL16-MALAT1 interaction remains under characterized. While knock-out mutants of METTL3 proteins suffer mild organismal consequences, those of METTL16 cause much more severe physiological abnormalities. How the conserved METTL16 enzymes fulfill an array of diverse and essential functions promises to be one of the fascinating directions in RNA biology.
Can emotional information be unconsciously processed by the brain? The subliminal affective priming effect provides rigorous evidence for this question. With the visual masking and continuous flash suppression paradigms, the subliminal affective priming effect has been found in tasks on attention and memory, social evaluation and even behavior preference when invisibly facial expressions are employed as primes. It has also been shown that the participants’ skin conductance level and cardiovascular reactivity are enhanced in these tasks. The findings from studies that aimed to explore neural mechanisms suggest that unconsciously perceived facial expressions have an influence on the early perceptual processing and late emotional meaning analysis of the target stimuli, in which the amygdala plays an important role. The affective primacy hypothesis and the feelings-as-information theory are proposed to explain the mechanism of the subliminal affective priming effect from the perspectives of domain specificity of affective system and affective attribution. Finally, potential directions for future studies are suggested.
The complex tumor microenvironment leads to the inefficient intra-tumor delivery of antitumor drugs severely restrict the therapeutic effect of drugs on superficial tumors. The biocompatible transdermal microneedles with high rigidity can effectively puncture the skin cuticle and deliver agents within the microneedle to superficial tumor tissues via controlled drug release, which would significantly improve drug bioavailability and avoid toxicity to livers/kidneys compared with conventional drug intravenous/oral administration. Here, the design of biocompatible transdermal microneedles for chemotherapy, photodynamic therapy, photothermal therapy, immunotherapy, cell therapy and vaccine in introduced. We also summarize the challenges of biocompatible transdermal microneedles-mediated superficial tumor therapy, to help promote potential translational superficial tumor applications of microneedles.
Under the background of precision medicine and personalized medicine, molecular diagnosis is more and more widely applied in pathogen detection, tumor diagnosis, eugenics and fertility, environmental protection, food safety and other fields, and continues to develop in the direction of molecular POCT(point-of-care testing)with advantages of fast and accurate, low-cost, simple operation. Ultra-fast pulse-controlled PCR (upPCR) is an extension and upgrade of real-time quantitative PCR (qPCR) technology, which uses energy pulses to control metal heating elements (mainly gold nanoparticles) in amplification reactions to complete the rapid heating of the local microenvironment of the solution within a few hundred microseconds, and realize the melting and denaturation of template DNA; After stopping heating, the reaction microenvironment can be rapidly cooled by the surrounding solution down to the extension temperature of the polymerase to achieve amplification of template DNA. A single denaturation-amplification cycle of upPCR is only 1.5-5 seconds, which is much faster than traditional PCR (about 90 seconds per cycle), and can thus greatly speed up the PCR reaction. On the basis of retaining the advantages of traditional qPCR such as high sensitivity, high specificity and multiplex detection, ultra-fast pulse control PCR technology adds new advantages such as ultra-fast reaction time (less than 15 min) and simple operation, which is very suitable for molecular POCT scenarios such as home detection and community screening. This paper mainly reviews the principle, core raw materials, equipments and applications of upPCR technology in molecular diagnosis, and discusses the advantages and disadvantages of this technology, as well as future technology development and application trends.
JING Wei,MA Fu-Qiang.Applications of Ultra-fast Pulse-controlled PCR(upPCR)[J]..Export: BibTexEndNote
Quorum sensing (QS) is a bacterial communication system that depends on bacterial density and is closely related to bacterial pathogenicity and drug resistance. Quorum sensing signal molecules are an important substance basis for QS system to regulate various cellular processes of microorganisms. The identification and detection of QS signal molecules is an indispensable link in the exploration of the regulatory mechanism of bacterial quorum sensing system. It is of important reference significance for the interaction, efficient detection and mechanism analysis of microorganisms such as bacteria in the fields of life science and pharmacy. It is illustrated that the photoelectric sensing detection is of great potential for the real-time detection of QS signal molecules with its high sensitivity and diversity of methods. Combining with molecular imprinting, biological receptor recognition, magnetic separation and so on, photoelectric sensor could provide more efficient means of detection. In this paper, the types of QS signal molecules and common QS systems were briefly introduced, and then the photoelectric detection methods and technologies of QS signal molecules were summarized. The sensitive media, sensing interface, sensing mechanism and testing effect of photoelectric sensing detection were discussed in details. The optical analysis techniques were of a wide range of applications in the detection of QS signal molecule in biological samples. Fluorescence detection method has high sensitivity in quantification of signal molecules, and fluorescence imaging method can provide real-time in situ observation of bacterial QS process. SERS spectral analysis technique could provide molecular fingerprint information of targets in the QS process of some biological samples. Electrochemical detection techniques could dynamically monitor QS signal molecules through the changes of electrochemical signals. Meanwhile, much more attention had been paid to microfluidic analysis technology, because it was taken as a favorable platform for the in-situ monitoring of bacterial QS signal molecules and QS process by the way of combining the photoelectric sensors and microfluidic control.
Piezo1 is a newly discovered mechanosensitive ion channel in mammals, which plays important functions in different tissues and organs, including bone, urinary tract, eyeball, and artery. However, abnormal Piezo1 mechanical transmission can cause a variety of diseases and promote the course of disease. Fibrotic disease can occur in almost any tissue and organ, and its main feature is excessive cross-linking and accumulation of collagen and other extracellular matrix components, which eventually leads to increased stiffness of tissues and organs and affected physiological functions. At present, more and more studies have shown that Piezo1 plays an important regulatory role in the occurrence and development of fibrotic diseases, which is closely related to the change of matrix mechanical state. This paper describes the structure and activation mechanism of Piezo1, and systematically summarizes the research progress of Piezo1 in fibrotic diseases of the heart, kidney, pancreas, liver and other organs, in order to provide a new perspective and strategy for the treatment of fibrotic diseases.
YIN Shi-Yun,CHEN Guo-Bao.Research Progress of the Mechanosensitive Ion Channel Piezo1 in Fibrotic Diseases[J]..Export: BibTexEndNote
Oncolytic viruses are a class of viruses that are naturally or genetically engineered to replicate specifically in tumor cells and exert anti-tumor effects. The anti-tumor effect of oncolytic virus is mainly achieved through the following two aspects: (1) direct oncolytic effect, such as inducing apoptosis of tumor cells and promoting cell lysis. (2) as a drug that activates immunity, oncolytic viruses induce the body to produce strong anti-tumor immunity and achieve the purpose of clearing tumors. As an important branch of immunotherapy, oncolytic viral therapy has become a research hotspot in this field due to its tumor specificity and convenient genetic modification. Until now, only four products have been approved for marketing, despite more than 100 cases of oncolytic viral therapies in the recruitment and completion stages of clinical trials. There continue to be many challenges in the application of oncolytic therapy in oncology treatment. Therefore, a systematic review of oncolytic virus modification strategies and an in-depth understanding of the biological processes of oncolytic viruses are all the more necessary. Viruses are host-dependent in their replication and proliferation processes, and their biological processes are closely related to the metabolic state of the host. The hallmark feature of tumors is metabolic reprogramming, the process by which tumor cells reconsider their metabolic networks to meet the demands of exponential growth and proliferation and to prevent oxidative stress. This typically includes enhanced glycolysis and glutaminolysis, as well as changes in mitochondrial function and redox homeostasis.
The replication of oncolytic viruses requires the synthesis of biological macromolecules, such as amino acids, lipids, nucleotides, etc. Viruses themselves do not encode relevant enzymes, so they often need to use the metabolic pathways of their host cells to synthesize the substances they need. Enhancing the replication and oncolytic ability of oncolytic viruses by targeting host metabolic reprogramming is a promising direction. It has been shown that lipid metabolism and intermediates are one of the ways in which viruses engage in dialogue with their hosts, and lipid rafts are essential components for oncolytic viruses to perform their infection and replication functions. Cholesterol depletion in host cells has shown conflicting results, presumably related to the type of virus. For example, the dependence of envelope and non-envelope viruses on lipid synthesis may differ, although this needs more literature support. The idea that enhanced glycolytic levels in host cells promote the infection, replication, and anti-tumor effects of oncolytic viruses is equally controversial. Oncolytic viruses replicate to a degree comparable to that of proliferative tumor cells, and both rely on glutamine metabolism to participate in the synthesis of biological macromolecules. Adenoviruses and VSV are significantly less able to replicate in states where the glutamine metabolic pathway is suppressed. Similarly, the level of host nucleotide metabolism is closely related to the replication capacity of oncolytic viruses and enhancing RNA reductase (RR) activity can promote HSV replication in tumors. Therefore, the use of oncolytic viruses to regulate host metabolic reprogramming, or in combination with drugs that can regulate host metabolism, is one of the directions to further improve oncolytic virus anti-tumor efficacy.
konglingkai,wujunhua.Research advances in the regulation of oncolytic viruses by targeting metabolic reprogramming[J]..Export: BibTexEndNote
After rapid development, the micro technology has broken through the optical diffraction limit, which mainly includes: 1) STED; 2) SIM; 3) PALM; 4) STORM; 5) MINFLUX; 6) SIMFLUX, etc. Considering the signal-to-noise ratio of fluorescence molecule signal acquisition, reducing the impact of photobleaching on imaging, and considering imaging resolution, we adopted STORM microscopic imaging technology. Multicolor imaging technology is helpful to the extraction of biological information. Three channel imaging is selected based on various factors, and GNP and cells are used for imaging verification. By optimizing the algorithm for the position shift caused by spectral overlap and hardware error, a good imaging effect is obtained, and each alignment error is guaranteed to be within 20 nm of the resolution of the super resolution microscope.
Marine macroalgae (including brown algae, red algae, and green algae) exhibit several features of an excellent feedstock for biorefinery, such as high yield of biomass, no occupation of arable land, and no requirement of fresh water. In 2021, the production of brown algae in China was 1.9 million tons, which was much higher than other economic algae. It is worth noting that the carbohydrate content of brown algae is as high as 60%, and three sugars, including alginate, fucoidan and laminarin are unique to brown algae. Amongst them, alginate is a linear anionic polysaccharide which consists of 1,4-linked C-5-epimers β-D-mannuronic acid (M) and α-L-guluronic acid (G). The decomposition of alginate is catalyzed by alginate lyases via β-elimination of glycosidic bonds. They produce various oligosaccharides with unsaturated uronic acid at the non-reducing end, or 4,5-unsaturated uronic acid monomers mannuronate (ΔManUA) and guluronate (ΔGulUA). Fucoidans usually consist of a backbone of α-1,3-L-fucopyranose residues or alternating α-1,3-linked and α-1,4-linked L-fucopyranosyls, and side branches containing glucose, galactose, rhamnose, xylose, mannose or glucuronic acid. The fucopyranose residues may be substituted with sulfate. The highly modified structure of fucoidans can significantly affect the cleavage of glycosidic linkages. Therefore, hydrolases that act on a branched chain and sulfatases are required for the primary degradation. Subsequently, L-fucoses are produced by a series of sulfatases and fucosidases belonging to GH29, GH95, GH107, GH141, GH151, or GH168 families. Laminarin, the storage polysaccharide in algae, is composed of a linear backbone of 20-30 residues of β-1,3-linked-D-glucopyranose and a branched chain of β-1,6-linked-D-glucopyranose. The glycosidic bond in its backbone can be broken by endo-β-1,3-laminarinases (EC 18.104.22.168 and EC 22.214.171.124) and exo-β-1,3-glucanases (EC 126.96.36.199). The β-1,6-glucanase (EC 188.8.131.52) releases glucose by breaking the glycosidic bond in the branched chain of laminarin. Algae-derived polysaccharides and their oligosaccharides have shown health beneficial effects, such as immunomodulatory, antitumor, anti-inflammatory, and other activities, which possess great potential as alternative, renewable resources in cosmetics and functional foods. In this review, we mainly focus on the efficient degradation of brown algae, and summarize the mechanisms adopted by these enzymes for catalysis and conformation changes of substrate specific recognition. Furthermore, it will provide insights for the precise customization of oligosaccharides and the construction of industrial biorefinery platform, thereby promoting the efficient conversion of brown algae.
Ubiquitination is a prevalent posttranslational modification in eukaryotic cells. Ubiquitination almost regulates all eukaryotic signaling pathways, thereby playing essential roles in eukaryotic cellular processes including immune responses. Bacterial pathogens inject a series of virulence proteins, named effectors, via special protein secretion systems, such as type III and type IV secretion systems, into the host cells to modulate host signaling pathways. Many effectors harbor unique enzymatic activities to modify ubiquitin or the ubiquitin-conjugating enzyme Ubc13, or have E3 ubiquitin ligase or deubiquitinase activities. This review summarizes the progresses and the newest discoveries on mechanisms of host ubiquitination modulation by bacterial effector proteins.
The planning and construction of Xiong'an New District is a major historical strategic choice made by the Party Central Committee in the context of the new era. Xiong'an and surrounding areas will undertake and usher in major historical missions and opportunities.As a frontier in the high-tech field, the future of medical development is a battleground, the 6th China Biophysical Society Nanobiology Branch Annual Conference of Nano Biomedicine, "Innovative Nano Drugs" Xiong'an Forum, it was held in Baoding City, Hebei Province, where Xiong'an was located on April 24-28，2019.
Yang Tong-Ren,HUANG Yuan-Yu.The 6th Annual Academic Conference of the Branch of Nanobiology of the Chinese Society of Biophysics and 'Innovative Nanomedicine' Xiongan Forum were successfully held[J]..Export: BibTexEndNote
Sponsored by：Institute of Biophysics, The Chinese Academy of Sciences; Biophysical Society of ChinaEdited by: Editorial Office of Progress in Biochemistry and BiophysicsPublished by：Editorial Office of PIBBEditor-in-Chief：HE Rong-Qiao Adress：15 Datun Road, Chaoyang District,Beijing 100101,China Telephone：86-10-64888459 Email：firstname.lastname@example.org Journal inclusion：SCI, CA, Scopus, AJ ISSN：1000-3282