Abstract:In vitro fertilisation (IVF) as one of the assisted reproductive technologies(ARTs) plays an important role in modern medical treatment of human infertility. The development of ART has not only broken through the natural way and process of human reproduction, but also exerted a great influence on the development of reproductive medicine. Therefore, British scientist Robert Edwards won the Nobel Prize in physiology and medicine in 2010 for the contribution of his research on the assisted reproductive technology.

Abstract:Epigenetics and avian influenza virus are two research fields subject to intensive studies and attracted much attention in recent years. Several interesting reviews and research articles well-organized into these topics were published in the 2009 edition No.4 and No.5 of Science in China Series C-Life Sciences (SCLS). The topic “Molecular epigenetics: dawn of a new era of biomedical research” consists of three review papers, which summarized the latest advances and perspectives in three different fields of molecular epigenetics, including the inheritance of histone methyl marks as well as the dynamic regulation of histone methylation by demethylation, the microRNA biogenesis and the mechanism by which microRNA function in post-transcriptional gene silencing, and RNA-directed DNA methylation and demethylation in plants. The topic entitled“The challenges of avian influenza virus: mechanism, epidemiology and control” contains seven review articles, one research paper and one website introduction. These papers concentrated not only the clinical aspects of avian influenza virus infection in China, but also the basic research in this field, which gave us a full picture on the spread of H5N1 virus, as well as how to combat it in China. These articles on H5N1 would be highly meaningful not only for scientists but also for ordinary people.

Abstract:The completion of the Human Genome Project (HGP) in 2001 heralded the coming of the post-genomic era, and also set off a new wave of RNA research. As the new frontier in the post-genomic era, RNomics are now a highlight in the life science, the discovery of diverse ncRNA challenge the traditional understanding that proteins are the only effectors of gene function. To display the latest progress in RNA research, the third issue of Science in China Series C-Life Sciences(2009) focus on non-coding RNA and RNomics with 8 review notes, covering the sncRNAs in animals and plants, miRNA in oncogenesis, cell differentiation and development, RNA targets for diagnosis and therapy, mRNA splicing, RNAs involved in genomic imprinting and evolution of ncRNA genes. This special topic shows the latest advances and some perspective on the non-coding RNA research field.

Abstract:UCH-L1 is abundantly expressed in brain which possesses ubiquitin hydrolase activity, ubiquitin ligase activity and the effect of monomeric ubiquitin stabilizing. UCH-L1 is critical for the normal morphology and function of the synapses, which can rescue the LTP deficit and impaired memory induced by β-amyloid protein (Aβ). In addition, the I93M mutation in UCH-L1 is associated with familial Parkinson's disease (PD) while the S18Y polymorphic variant of UCH-L1 is associated with a specific antioxidant protective function in neurons. By researching the structure, function and the mechanism in the nervous system of UCH-L1, hopes to provide a concept or a method to treat neurodegenerative diseases such as AD and PD.

Abstract:Parkinson's disease (PD) is the most frequent progressive neurodegenerative movement disorder, and autosomal dominant inherited PD can be caused by LRRK2 mutations. The new findings of LRRK2's function were summarized and described in 10 aspects, such as molecular genetics, expressing distribution and subcellular localization, function of mutants, protein chemistry, protein dynamics, interacting protein and substrate, signal transduction pathway, connection with neurite and synaptic vesicles protein, structure analysis, pathological and clinic features. It was pointed out that these achievements have preliminarily clarified the pathogenic mechanism of how LRRK2 mutants cause PD, and presented the new strategies for treatment of PD. Finally, the future researches were previewed.

Abstract:The receptor-interacting protein 3 (RIP3) is a member of RIP kinase family, which has highly conserved serine/threonine kinase activity. Increasing number of evidences has revealed RIPs to be essential sensors of cellular stress and a key regulator of cell apoptosis, necrosis and survival. Recent studies demonstrating RIP3 as a possible trigger for cellular necrosis in response to TNF-α family of death inducing cytokines may lead to new strategies for developing cancer therapy. This review focuses on the biological characteristics and structure of RIP3 protein, and its cell death control function between apoptotic and necrotic.

Abstract:As shown by many researches, various lipids are not only involved in many cellular processes, such as plant signal transduction, vesicular transport, and cytoskeletal rearrangements, but also play a pivotal role in mediating plant growth, development and stress responses. However, due to the diversity and complexity of lipids, and the limitation of analytical approach, its hard to have a deep understanding on lipids. Electrospray ionization tandem mass spectrometry (ESI-MS/MS) is a direct-infusion, high-throughput analytical strategy. By utilizing this approach, most lipid molecular species can be quantified in a short time only need small samples, detection of minor changes in plant lipids induced by environmental changes and growth and development has thus been greatly facilitated. The successful application of this approach in plants has led to great progress in plant lipidomics in recent years. Functions of some lipids and lipid-hydrolyzing enzymes in plant stress and defense responses have been revealed, and several novel genes related to plant lipid metabolism have been identified, all owing to the facilitation of this approach. Moreover, some new discoveries related to lipid distribution, transport, and transformation and identification of new lipid species have been made through the ESI-MS/MS approach coupled with other lipid analyzing methods. The paper firstly gives a brief depiction on the characteristics of the ESI-MS/MS approach, then provides an overview of application advances of the approach in plant lipidomics, and offers some prospective options to its future development in the final part.

Abstract:Transcriptional regulation mechanisms have not been clearly illuminated for NGX6 gene, which is a candidate of tumor suppressor gene in colorectal cancer. pGL3/Enhancer/1126 vector, a recombinant reporter gene vectors of the transcription regulatory region of NGX6 gene, was constructed based on bioinformatic techniques and identified by luciferase assay system. No canonical TATA boxes, but several CAAT and GC boxes were observed in the transcription regulatory region by the online analysis programs PromoterInspector program, FistEF, CpGplot and MatInspector Professional. Transcriptional factor Sp1 was validated to bind to NGX6 promoter by electrophoretic mobility shift assay (EMSA). Inhibition of the Sp1 binding to NGX6 promoter by mithramycin A significantly reduced the promoter activity. The endogenous expression of NGX6 in mRNA level was down-regulated by mithramycin A and blocking with Sp1.

Abstract:To evaluate the feasibility of using magnetic iron oxide nanoparticles (pll-DCIONP) as HIF-1α shRNA gene carrier for transfection in vitro and in vivo, and the effect of HIF-1α targeted RNA interference for reversing cisplatin resistance in human lung adenocarcinoma A549/CDDP. The HIF-1α shRNA was constructed and transfected into A549/CDDP and its xenograft animal model by pll-DCIONP and lipo2000, respectively. Fluorescent microscopy was employed to compare the transfection efficiency in vitro. The expression levels of HIF-1α, MRP1 and LRP after transfection were detected by reverse transcription polymerase chain reaction (RT-PCR) and immunocytochemistry analysis. Immunohistochemical analysis was performed to compare the levels of HIF-1α, MRP1 and LRP in transplanted tumors among different groups. In order to calculate the cisplatin resistant, MTT assay was performed to detect the cell half-maximum inhibitory concentration (IC₅₀). The growth index of transplanted tumors after transfection were detected among groups. Additionally, HE staining of liver, kidney and brain tissues was used after magnetic iron oxide nanoparticles transfection. The method of pll-DCIONP was more efficient on transferring plasmid into cells than the lipids examined in vitro (P < 0.01). The mRNA and protein levels of HIF-1α, MRP1 and LRP of A549/CDDP were decreased after transfection with HIF-1α shRNA, and the resistance to cisplatin of A549/CDDP was reversed by 82%. The protein levels of HIF-1α, MRP1 and LRP in A549/CDDP transplanted tumors were decreased after transfection with HIF-1α shRNA; also, the growth of A549/CDDP transplanted tumors were inhibited by HIF-1α shRNA, cooperating with the synergistic effect of cisplatin. No necrosis of liver, kidney and brain tissue were observed after magnetic iron oxide nanoparticles transfection. The pll-DCIONP could be used as one of the ideal gene carriers for HIF-1α shRNA gene delivery in vitro and in vivo. HIF-1α can be an effective target for reversing cisplatin resistance in lung cancer, the mechanism underlying may be related to the decreased expression levels of HIF-1α, MRP1 and LRP after transfection with HIF-1α shRNA, and magnetic nanoparticle-mediated HIF-1α shRNA transfection has biological safety to some extent.

Abstract:Fully human antibody fragment Fab that specifically binding to Trop-2 (trophoblast cell-surface antigens 2, Trop-2), was selected from phage display antibody library. Positive phage-displayed antibody clones were selected on live cell lines and immobilized protein. The purified Fab was verified by SDS-PAGE and Western blot, which showed two bands at about 28 ku and 32 ku at the expected sizes. To analyze the immunological characters of Fab for Trop-2 binding, flow cytometry, immunoprecipitation assays and mass spectrometry were set up and carried out with BxPc3 and NIH3T3 cell lines. The results demonstrated Fab could bind native Trop-2 specifically on the BxPc3 cell surface. Peptide mapping fingerprint showed that the protein which bound is Trop-2 protein. Immunohistochemistry detection illuminated Fab could bind the membrance protein of pancreatic cancer tissue. In vitro cell growth inhibition assay showed that anti-Trop-2 Fab could inhibit the Trop-2 positive cell BxPc3 growth, it illuminated that anti-Trop-2 Fab bound the Trop-2 on Trop-2 positive cell surface. For Trop-2 negative cell line NIH3T3, no significant inhibition among the different dosages of Fab. The results showed that anti-Trop-2 Fab antibody fragments could recognize Trop-2 extracellular domain in native conformation, making them as potential powerful reagents for clinical therapeutic application.

Abstract:The physiological role of brown adipose tissue (BAT) is quite different from that of white adipose tissue (WAT) by dissipating energy as heat instead of generating ATP. Mitochondrion is an essential organelle that plays a crucial role in energy production and cellular homeostasis. To gain a better understanding of energy metabolism in BAT, mitochondria were isolated and a systematic analysis of protein patterns was performed in WAT and BAT of rat with two-dimensional gel electrophoresis. Differentially expressed proteins were identified using mass spectrometry and it was found that the proteins involved in lipid and amino acid metabolisms, TCA cycle, and respiratory chain are more abundant in BAT than in WAT, which are further up-regulated in response to cold exposure in BAT. Furthermore, the study reveals, for the first time, a subset of COQ genes required for Coenzyme Q biosynthesis are significantly up-regulated after cold exposure in BAT. These findings suggest that Coenzyme Q increase is implicated in the non-shivering thermogenesis and contribute new data for understanding the unique process of energy metabolism in BAT.

Abstract:Reduced glutathione (GSH) plays an important role in plant resistance to biotic and abiotic stresses. A putative glutathione transporter gene, ZmGT1, was cloned from maize (Zea mays) using RACE-PCR. The deduced ZmGT1 protein is highly homologous to glutathione transporters from other plants. A yeast mutant (hgt1Δ) deficient in glutathione transport was used to characterize the physiological functions of this gene. Complementation by ZmGT1 restored growth of the hgt1Δ mutant strain on a medium containing GSH as the sole sulfur source and also mediated the uptake of a model glutathione conjugate, GS-N-ethylmaleimide (GS-NEM). ZmGT1 was expressed in all organs of maize seedlings, with a higher level of transcript being found in leaves. The expression of ZmGT1 was strongly induced by atrazine with a 4～5 fold increase in transcript level being detected in leaves after 96 h treatment. The strong up-regulation of ZmGT1 by atrazine suggests that this glutathione transporter may be involved in the detoxification of xenobiotics.

Abstract:In the previous reports, BMP9 has shown potent function to induce osteogenesis, but the underlying molecular mechanism of osteogenesis induced by BMP9 is needed to be deeply explored. Dominant negative typeⅡ TGFβ receptors and BMP9 were constructed by following recombinant adenoviruses protocol and co-introduced into target cells. Then the typeⅡ TGFβ receptors required for BMP9-induced osteogenesis was identified and analyzed through in vitro and in vivo assays. It was found that three dominant negative typeⅡ TGFβ receptors, which are dnBMPRⅡ, dnActRⅡ and dnActRⅡB, can not only reduce alkaline phosphatase (ALP) activity induced by BMP9 and calcium deposition, but also repress the activation of Smad signal pathway. Moreover, dnBMPRⅡ, dnActRⅡ and dnActRⅡB also showed to inhibit ectopic bone formation induced by BMP9 in vivo. However, target cells expressed BMPRⅡ and ActRⅡ, but not ActRⅡB. Then, when BMPRⅡ and ActRⅡ were silenced by RNA interference in target cells, luciferase reporter activity and ALP activity induced by BMP9 was accordingly inhibited along with knockdown of BMPRⅡ and ActRⅡ. Taken together, those results intensively suggest that BMPRⅡ and ActRⅡ are the functional typeⅡ TGFβ receptors required for BMP9 induced osteogenesis.

Abstract:In order to explore the mechanisms of candidate liver tumor suppressor protein PIG11 induced apoptosis, eleven PIG11 binding proteins were first time identified in human hepatoma HepG2 cells, which heat shock protein 60 (Hsp60) is one of them. It has been confirmed by co-immunoprecipitation combined with Western blot analysis. Furthermore, using Western blot analysis, the protein expression of Hsp60 is down-regulated in pLXSN-PIG11-HepG2 cells group than that of pLXSN-HepG2 and HepG2 groups(n=3, P < 0.01), and over-expression of PIG11 induces translocation of Bax protein from cytoplasm to mitochondria in HepG2 cells. These results suggested that PIG11 protein can combine with Hsp60 in HepG2 cells, and the over-expression of PIG11 induce HepG2 cells apoptosis through mitochondrial pathway and the translocation of Bcl-2 family proteins Bax from cytoplasm to mitochondria maybe play an important role in the process.

Abstract:Particle detection of fluorescent images has become an indispensable tool in biological research. Here a simple and fast method for biological particles detection with high efficiency and accuracy, improved wavelet transform (IWT) was introduced. IWT originates from wavelet multiscale products (WMP). However, it resolves the problems in WMP and is more adaptive in dealing with different types of images. The performance of IWT, WMP and MSVST (multiscale variance stabilizing transform) was quantitatively evaluate by using both synthetic and real fluorescence images. Experimental results show that IWT performs much better than WMP in most cases, and has comparable results with the much complicated algorithm, MSVST. Besides, IWT is 20% faster than MSVST when processing the same images. Therefore, it was concluded that IWT can be generally used for the automatic detection of different kinds of biological particles, and the simplicity and accuracy make it a better choice for fluorescent image analysis.