Abstract:Organoid can make up for the deficiency of cell models and animal models commonly used in traditional research. And it also provides an important experimental basis for the study of key functional studies of living organisms. At the present stage, organoid model has become a hot research field and is of great significance in disease mechanism research, drug screening, regenerative medicine, and biomedical material evaluation. In this paper, the research of organoids in the past 10 years is reviewed. It summarizes the development history and research status of organoid research, and also focuses on the main research fields of organoids. In addition, this paper mainly analyzes the key scientific issues in the study of organoids and propose ideas for organoid in biomedicine, regenerative medicine and precise treatment of diseases.

Abstract:Single-cell RNA-seq provides information on the differences in gene expression, making it possible to study the cells and the mechanism of their interactions at the single-cell level. In recent years, single-cell transcriptome technology has experienced the development at the principle of cDNA amplification from homopolymer tailing-based, in vitro reverse transcription to template-switch, and greatly improved the sensitivity. At the same time, cell isolation is promoted from 96/384 well plates, droplets to nano-pores, which greatly reduced the experimental cost while increasing the throughput. The single-cell RNA-seq, with its advantages in cell heterogeneity and cell classification, has promoted the construction of cell atlas from developmental biology to normal tissue and pathological cell biology. This paper reviews the recent progress of single-cell RNA-seq and its application in human cell atlas.

Abstract:The virus-like particle (VLP) of murine polyomavirus (MPV) is a spherical shell with nanostructure. It assembles from protein VP1, the major structural protein of capsid. MPV VLP has a unique nanostructure that can self-assemble in vivo or in vitro and many sites that can be modified. The special architecture make it an ideal nanoscale model in scientific fields such as biochemistry. With the modification of the protein capsid and the transformation of the core cavity, researchers have developed a series of vaccines, multifunctional diagnostic agents and versatile nanocage systems. Recent studies of MPV VLP modification have focused on the interface modification between subunits to facilitate the assemble process, and the interior or exterior modification to develop diverse applications. This paper reviews the structural characteristics of MPV VLP, and briefly introduces the expression systems and assembly mechanism. The modification of MPV VLP was summarized, with emphasis on chemical modification and modification using genetic engineering. In addition, the applications of MPV VLP in the fields of vaccine development, delivery of drug and other molecules were described with examples. Then the prospect of research on MPV VLP was discussed, focusing on the large-scale production and in-depth analysis of assembly mechanism, beneficial from the use of advanced science and technology.

Abstract:Biomacromolecules refer to the substances such as DNA, proteins, polysaccharides, etc. in living organisms, which are essential for the normal life activities of organisms. De novo synthesis and design techniques have high degree of freedom and simple precursors in the synthesis and structural design of biomacromolecules, enabling new design and efficient synthesis of biomacromolecules for specific research purposes. Recently, de novo synthesis and design techniques have begun to receive attention in the fields of artificial gene combination, novel protein drug design, glycoconjugate synthesis, etc. Based on the de novo synthesis and design of biomacromolecules, the newly designed DNA or novel gene expression products, as well as glycosylation or glycoconjugates with recognition functions, can be targeted prepared. Simultaneously, the techniques will greatly advance biologically active substances such as cytokine mimics, gene therapy delivery vehicles, providing a new solution for the construction of artificial biological systems and the treatment of rare diseases. This paper reviews the de novo synthesis and design of DNA, protein and polysaccharides, expounds the related methods and applications, and finally summarizes the relationship between three kinds of substances.

Abstract:Epstein-Barr virus (EBV) has a relatively large double-stranded DNA genome. The EBV genome is approximately 172 kb in length. EBV has been associated with several cancer types, such as nasopharyngeal carcinoma, lymphoma and gastric cancer. EBV miRNAs can regulate gene expressions of virus and host cell, and play a variety of roles in the development of EBV-associated cancers. This article reviews the biological functions of EBV miRNAs in viral infection, oncogenesis, tumor invasion and metastasis, anti-apoptosis, signaling pathway, and potential significance as biomarkers for diagnosis of EBV-associated cancers. EBV miRNAs may be candidate targets of the therapy for EBV-associated cancers.

Abstract:Atg11, as scaffold proteins, mainly mediated the formation of autophagosome in selective autophagy through its many helical domains. Selective autophagy could specifically remove damaged biomolecules and organelles and played an important role in the intracellular material turnover of eukaryotes. Firstly, the structural features of Atg11 were briefly introduced. Secondly, the roles of Atg11 in three kinds of selective autophagy including Cvt pathway, peroxidase autophagy and mitochondrial autophagy were introduced. Finally, the other features of Atg11 were briefly summarized. This review systematically summarized the research progress of Atg11 in recent years, so as to provide references for the formation of autophagosomes and the function of Atg11 in this process.

Abstract:Deep brain stimulation has been used to treat movement disorders such as Parkinson diseases by utilizing high-frequency stimulations (HFS) of electrical pulses with constant inter-pulse-intervals (IPI). To develop new stimulation paradigms for treating more brain diseases, HFS with varying IPI (i.e., varying-frequency) has been investigated. Previous studies have shown that the efficacy obtained by varying-frequency is different from that obtained by constant-frequency even with a same mean frequency. We hypothesized that small changes in IPI during HFS could substantially change the effect of HFS on neurons. To test this hypothesis, HFS sequences with constant IPI (IPI = 10 or 7.5 ms for a frequency of 100 or 133 Hz ) and varying IPI (IPI = 5-10 ms with a mean frequency of 133 Hz) were alternately applied at afferent axon fibers of pyramidal cells in rat hippocampal CA1 region. The evoked potentials of downstream neurons were recorded and analyzed to quantitatively evaluate the neuronal responses to stimulations with constant IPI and varying IPI. The results showed that during persistent stimulation with constant IPI, the responses of downstream neurons changed from initial synchronized firing of population spikes (PS) into non-synchronized firing (i.e., unit spikes). However, once the stimulation switched to the sequence with varying IPI, synchronized firing reappeared with large PS events. Additionally, the amplitude of PS and the synchronization degree of firing induced by varying IPI were similar to those induced by single pulses at baseline. However, the incidence of PS was only ~7% of the pulse frequency, indicating a cumulative action of multiple pulses for generating such synchronized firing of neurons by stimulations with varying IPI. In addition, the appearance of PS was related to the length of proceeding IPI. Presumably, nonlinear responses of neuronal axons and synapses to high-frequency stimulation might cause the synchronized activity induced by varying-frequency. These results indicate that tiny differences in intervals of varying-frequency stimulation may generate a modulation effect on neurons very different from that of constant-frequency stimulation. The present study shows important results for revealing the mechanisms of brain stimulation and for advancing the development of new stimulation paradigms to treat various brain diseases.

Abstract:Nerve growth factor (NGF) can bind to cell surface receptor p75NTR and TrkA and play a vital role in cell differentiation, survival, apoptosis, proliferation and migration. TrkA interacted with multiple proteins in vivo, but due to the complexity of the NGF signaling pathway, it is still necessary to explore more proteins that interact with TrkA to gain a more accurate understanding of the NGF pathway. Here we report eIF4A1 is a new partner of TrkA. We found eIF4A1 interacted with TrkA via the yeast two hybrid assay. And then the association between TrkA and eIF4A1 was identified by GST pull-down and co-immunoprecipitation assay. Additionally, NGF stimulated this interaction and the associated binding domain is the N-terminus domain (NTD) in eIF4A1 and the TK domain in TrkA. And eIF4A1 could colocalize with TrkA at cell membrane. Furthermore, eIF4A1 also inhibits TrkA polyubiquitination through lysine (Lys)-63-linked polyubiquitin chains which causes its internalization. So eIF4A1 plays a novel role in NGF signaling pathway.

Abstract:Fabry disease(FD) is a rare X-linked recessive hereditary lysosomal storage disease. One of the most commonly used biomarkers for detecting FD is Lyso-GB3, a globotriaosylsphingosine, which is usually analyzed by liquid chromatography-tandem mass spectrometry(LC-MS/MS), because of its high specificity and sensitivity. Due to the complexity of LC-MS/MS technology, efficient and reliable diagnosis of FD by LC-MS/MS was unavailable in most hospitals in China. Therefore, patients’ samples need to be prepared at local hospitals and then sent to central laboratories for LC-MS/MS analysis. As a result, samples undergo a lengthy shipment and storage process, potentially compromising sample quality and thus precision of diagnosis. We first established and validated a novel LC-MS/MS-based method and to guarantee FD sample quality, we studied the effects of pre-analytical variables on the analysis of Lyso-GB3. These pre-analytical variables include storage temperature and time of plasma, freeze-thaw cycles of plasma, degree of hemolysis of plasma, storage temperature and time of whole blood, and centrifugation temperature. Finally, we analyzed 86 FD samples and 100 normal human samples and made correlation studies on the relationship between Lyso-GB3 level and FD classification. Results showed Lyso-GB3 level started decreasing post 4 days when plasma was stored at 20°C. In addition, hemolysis significantly influenced the FD sample quality and severe hemolysis caused the Lyso-GB3 level decreased by 57.8%. Other pre-analytical variables have little impact on FD sample quality. Under the conditions of the standard operational procedures before analysis, the sensitivity and specificity for screening FD is 100%, which ensures the accuracy of the method. Furthermore, we used plasma Lyso-GB3 level to distinguish classical FD patients from non-classical FD patients. When we set the cut-off value as 55.15 μg/L, the sensitivity and the specificity were 71% and 100%, respectively. The area under the receiver operating characteristic curve was 0.83. Our findings can help standardize the operational procedures in medical labs to guarantee high FD sample quality and provide a reference for identification of Chinese FD classification.