Abstract:Membrane fusion between the viral envelope and host cell membrane is a key step for an enveloped virus entering into the host cell. The process involves intricate interactions between and conformational changes of viral envelope glycoproteins and corresponding cellular receptors. Herpesvirus contains many glycoproteins and different types of cellular receptors, the transformable receptor-glycoprotein complex constitutes a multipartite entry-fusion system. The molecular mechanisms of membrane fusion are generally regarded as the one of the most challenging issues in the study of enveloped virus. Much progress has been made recently in achieving a substantially improved knowledge base of this subject. A comprehensive review was presented on the structures and functions of important viral glycoproteins and receptors, formation of a receptor-glycoprotein complex during herpesvirus entry, and associated pathways. Detailed models of viral membrane fusion are also given. In addition, the prospect of future research is addressed.

Abstract:Alzheimer′s disease (AD) is one of the most prevalent neurodegenerative disorders. However, the mechanisms of the disease are still unclear. Increasing evidences demonstrated that mitochondrial dysfunction and structural abnormalities induced by Aβ play important roles in this disease. β-Amyloid (Aβ) induced mitochondrial damage can be attributed to reduced activities of several key enzymes of mitochondrial energy metabolism, impaired balance of mitochondrial fission and fusion as well as mitochondrial membrane permeability transition pore (mPTP) formation. The recent progress in the mechanisms of Aβ induced mitochondrial damage was summarized.

Abstract:Non-genomic effects of estrogen exist largely in female reproductive system. Through genomic and non-genomic pathways, and their integration, estrogen performs different physiological functions in various target tissues. In the ovary, estrogen functions as a reactive oxygen scavenger and protects ovarian cells from apoptosis through non-genomic pathway. Estrogen also regulates the expression of uterine genes in an estrogen receptor-independent manner. The review on estrogen non-genomic effects will be beneficial for understanding the mechanism of estrogen action.

Abstract:p16^INK4a plays a key role in control of cell cycle progression by negatively regulating the CDK4/6 activity. It was shown that histone acetyltransferase p300 had a positive effect on the activation of p16^INK4a promoter, whereas, histone deacetylases HDAC3/4 counteracted the p300-mediated activation of p16^INK4a promoter, and decreased the p16^INK4a mRNA and protein levels. Chromatin immunoprecipitation (ChIP) tests revealed that the transfection of p300 reversed the hypoacetylation status of histones at the p16^INK4a promoter mediated by HDAC3/4. Moreover, the immunofluorescence study showed that the nucleo-cytoplasmic shuttling of HDAC4 may play an important role. Furthermore, Western blot and ChIP assays demonstrated that the HDAC inhibitor sodium butyrate (NaBu) enhanced p16^INK4a expression through inducing histone hyperacetylation. Based on these data, a hypothetical model was proposed for the involvement of reversible histone acetylation in transcriptional regulation of the p16^INK4a gene.

Abstract:In order to establish pig induced pluripotent stem cells (iPS) with defined factor fusion protein, four defined factors genes Oct4, Sox2, c-Myc and Klf4 were delivered into porcine fetal fibroblasts by lentiviral transfection. The porcine fetal fibroblasts expressed exogenous defined factor genes were sub-cultured, and the clear-cut cell clones were gradually isolated. The cell colones grew at similar rates and stability, exhibited normal karyotype, and expressed alkaline phosphatase, Oct4, Nanog and SSEA1. And these cells could differentiate into various kinds of tissue in teratomas. The results confirmed that the isolated cell clones were iPS cells. This would greatly facilitate the further improvement of the induction protocol and in-depth study and application of pig iPS cells.

Abstract:The theory of topological visual perception was proposed in previous studies. According to this theory, topological properties, as a global properties, is the primitive of visual perception, and figures with topological differences could be discriminated easier than figures with local feature differences. The different topological properties pattern recognition was investigated in mice by using a modified Y-maze. Two stimuli of topological different features were used to train mice to distinguish between ring and square. Besides, a ring and a square, the other stimulus which topologically features different or same carried as test. These stimulus patterns include a hollow square, a disk, a ring with a gap and a hollow square with a gap. The results showed that the mice trained to discriminate the ring (the reward pattern) from the square(the not reward pattern)were unable to distinguish between the disk and the square as well as the ring and the hollow square, but were able to discriminate the hollow square from the ring with a gap, the hollow square with a gap or the disk, respectively. The data suggest that visual system in mice may be sensitive to topological distinction and extract the topological properties to transfer. Moreover, these findings provide a new evidence for the hypothesis that topological perception is a fundamental property of vision.

Abstract:Based on a large spectrum of US28, planning to find out new antagon. Membrane spanning domain and epitopes were used to predict a binding mimotope that US28 bound with CC chemokines, the result of which were used to design and synthesize the peptide. The 12 peptide phage library was built sourcing from 25 different chemokines random phages including four families. The binding mimotope of synthesized peptide was screened by phage display technique, and assessed by ELISA assay. PL+S method was used to screen the 12 phage library with the target as biotinylated soluble form peptide H22. Biological activity of H22 were measured with cellular chemotaxis assays and calcium mobilization. Amino acid sequences of the displayed peptides in 10 phage clones were deduced from DNA sequences. They are GSESLNAHCALW, EIDGFNAHCALL, VIARLNAHCALR, ATECLNAHCALW, VIESLNAHCALW, DNGSINAHCALL and VKKTLNAHCALR. Every peptide sequence contains at least 2 hydrophobic residues. Eight of the 10 clones have a conservative sequence LNAHCAL. Chemotaxis assays showed that H22 induced migration of peripheral blood mononuclear, and H22 suppressed PBMCs' migration induced by hMIP-1β and EC₅₀=30.9 μg/L. H22 itself was not remarkably associated with the normal, rapid mobilization of calcium from intracellular stores. Instead, it blocked calcium mobilization induced by endogenous chemokines. It proves that using chemokine sequence of human source to build a peptide library and screen effective sequence is available. The conservative sequence could simulate the binding mimotope of Human MIP-1β interacting with HCMV US28 N-terminus to bind with synthesized peptide H22. The study has demonstrated that peptide H22 cannot stop the biological function of hMIP-1β and block the signal transduction from hMIP-1β by the way of calcium pathway, but itself did not affect cells activity.

Abstract:MG132(Z-Leu-leu-leu-CHO) is an inhibitor of proteasome, and it can reversibly inhibit the activation of proteasome, thereby inhibiting the degradation of protein which involved in ubiquitin-proteasome pathway(UPP), and inducing apoptosis at last. Study demonstrated that MG132 was capable of inhibition the proliferation of Bel-7404 hepatocarcinoma cell. After treated with different-concentration of MG132 at different-time, the change of morphological change and endoplasmic reticulum stress, formation of autophagic vacuoles and apoptotic bodies, cells viability, cell apoptosis, the protein expression of both apoptosis and autophagy signaling pathway related genes formation of in Bel-7404 cells were assessed by fluorescence microscope, Hoechst33342 staining, MTT assay, AnnexinⅤ/PI flow cytometry, Western blotting and transmission electron microscopy analysis. The results suggested that MG132 can inhibit Bel-7404 cells growth remarkably . It was able to activate Caspase-12 through endoplasmic reticulum stress pathway, can also influence the level of Bcl-2/Bax, and consequently induced releasing of cytochrome c through mitochondrial pathway. Both of the two different signaling pathways can activate Caspase-3 and PARP. Furthermore, MG132 increased the expression of Beclin1 and LC3B. Autophagic vacuoles were also detected by transmission electron microscopy analysis. It was confirmed that MG132 inhibited the growth of Bel-7404 cells not only via apoptosis pathway, but also related with autophagy pathway.

Abstract:There is accumulating evidence that apoptosis plays a key role in genesis of epilepsy, but the relationship between apoptosis and drug resistance in medically intractable epilepsy is not clear. The effect of XIAP antisense oligonucleotides on drug resistance in K562/Dox cells and rats of intractable epilepsy was investigated. The multidrug resistance cell line K562/Dox was established, and the expression of XIAP in K562/Dox cells and normal K562 cells was observed. After XIAP antisense oligonucleotides was transiently transfected into K562/Dox cells, mitochondrial membrane potential was assessed using JC-1. At the same time, antiepileptic drugs resistant in K562/Dox cells was measured by MTT. In addition, the model of intractable epilepsy was established by kindling of amygdale in rats. After XIAP antisense oligonucleotides was applied to PHT-CBZ resistant rats by lateral ventricle, after discharge threshold(ADT) and after discharge duration(ADD) was observed. The results showed that the expression of XIAP was significantly increased in K562/Dox cells compared with K562 cells. After XIAP antisense oligonucleotides was transiently transfected into K562/Dox cells, the expression of XIAP was regulated down, and mitochondrial membrane potential of K562/Dox cells was decreased. Moreover, XIAP down-regulation could increase the sensitivity of K562/Dox cells to antiepileptic drugs. The level of IC₅₀ was decreased significantly in K562/Dox cells, and the reversal index were 1.76 and 1.73, respectively. Furthermore, animal studies found that, compared with control group, ADT was significantly higher (P < 0.05) and ADD shortened in PHT-CBZ resistant rats after XIAP antisense oligonucleotides was applied. It is obvious that the expression of XIAP was significantly increased in drug resistant K562/Dox cells. Down-regulation of XIAP could reverse the drug-resistance of K562/Dox cells, and improve the electrobiological activity in PHT-CBZ resistant rats. These findings indicate that XIAP is involved in multidrug resistance in medically intractable epilepsy.

Abstract:Hydrostatic pressure has direct effect on vascular endothelium. Endothelial lipase (EL) is a newly identified member, only secreted by endothelial cells, of the triglycerides lipase family. EL may be one important determinants of HDL-metabolism and inflammation acting at the vessel wall. However, little is known about regulation of EL at the vessel wall. The effect of hydrostatic pressure on EL and its possible mechanism were investigated. In human umbilical vein endothelial cells, increasing pressures (120, 150 and 180 mmHg) treatment in a custom-made pressure incubator increased the mRNA and protein expression level of EL without obvious cells apoptosis.180 mmHg treatment up-regulated EL mRNA and protein about 2.2, 2.54 fold relative to pressure atmosphere, respectively. Inhibitor of nuclear factor-κB MG132 attenuated the high pressure induction of EL expression level, which is half of EL expression in 180 mmHg treatment group. These findings provide new insights into the effect of hydrostatic pressure on EL expression through nuclear factor-κB signal pathways.

Abstract:Tea plant flower is a product of the tea plant during its growing. Polysaccharide are abundant in tea flower. However, the components in tea flower are underutilized at present. The study aimed at evaluating the antitumor activity and immunomodulatory effect of tea plant flower polysaccharide (TFP) via various in vivo assay systems. The inhibition effect of TFP on sarcoma 180 tumor (S180)-bearing mice was observed at dosages of 75, 150 and 300 mg/kg by systematically to measure the S180 tumor inhibition rate, mice survival rate and cellular immunity. The result showed that continuous administration of TFP for 10 day continuously was found to inhibit the growth of transplanted S180, prolong the mice survival days, promote the plasma interleukin-2, interferon-γ levels and improve the T-lymphocyte subsets CD4⁺ and CD4⁺/CD8⁺ percentages after treatment with TFP. In addition, TFP was found to increase the delayed-type hypersensitivity response and macrophage phagocytosis significantly. These results strongly suggest that TFP enhances the host defense response to tumor due in part to the immunomodulatory activity.

Abstract:To examine the active site of recombinant buckwheat trypsin inhibitor (rBTI), two mutants (R45A-aBTI, R45F-fBTI) were generated through site-directed mutagenesis. Activity analysis found that the aBTI and fBTI had lost trypsin inhibitory activity. However, aBTI and fBTI showed new inhibitory activities against elastase and chymotrypsin, respectively. This result suggested that Arg⁴⁵ is the active site of rBTI. These inhibitors showed remarkable stability to heat and pH. The possible effects of aBTI and fBTI on the proliferation of human HL-60 and EC9706 cell lines were investigated by MTT assays. It indicated that aBTI and fBTI could specifically inhibit the growth of HL-60 and EC9706 cells in a dose- and time-dependent manner. The active site of rBTI was determined and two new inhibitors were obtained in this research. Knowledge about the active site is useful for further clarifying the physiological mechanism of rBTI and other protease inhibitors. New inhibitory activities of aBTI and fBTI are potentially useful in the fields of health and medicine.

Abstract:To dissect the splicing mechanism is a critical step in understanding the plant morphogenesis, growth, development and responses to stresses. Compared to animals, the research on RNA splicing is progressing poorly in plants. The splicing patterns of gene fragments derived from monocot rice BADH2 and dicot Arabidopsis GR7 were detected by Agrobacterium-mediated tobacco transient expression system. The results indicated that the fundamental splicing regulatory elements are conserved in plants. The tobacco transient expression system could be used as an important tool for fast and sensitive detection of gene splicing regulation in higher plants.

Abstract:OsWRKY89, a rice WRKY transcription factor gene, is induced by UV-B radiation. To identify the cis-elements in the OsWRKY89 promoter related to UV-B response, the promoter and its deleted fragments were each fused with gus reporter gene and transformed into rice calli. The transgenic plants regenerated were used to analyze their responses to UV-B irradiation. Finally, an UV-B response cis-regulatory element was narrowed to the region of 25 bp between -1 188 and -1 213 upstream the translation start site of OsWRKY89 gene, including nucleotide sequence of AAGATCTACCATTGCTCTATAGCTT. Through analysis of the promoter of OsWRKY89 and 28 genes up-regulated by UV-B treatment, two relatively conserved UV-B response elements in the 1 500 bp protmoter region studied were located. Coincidental, the 25 bp of OsWRKY89 promoter contains one of the conserved elements. Furthermore, several conserved light-response elements including ACE^OsWRKY89, MRE^OsWRKY89 and UVBox^AtANAC13 were also found to adjoine to the 25 bp UV-B response region in the OsWRKY89 promoter, suggesting they together play roles in regulating the light responses of the gene.

Abstract:Sepsis is one of the most serious problems of modern medicine nowadays and improvements in treatments are urgently needed. Bone marrow derived stromal cells (BMSCs) have a potent immunosuppressive effect in humans in vivo. IL-10, a cytokine synthesis inhibitory factor, plays an important role in anti-inflammatory response. Here BMSCs were infected with recombinant adenovirus encoding murine IL-10 (mIL-10) and a GFP marker to obtain GFP positive BMSC-mIL-10 cells. The BMSC-mIL-10 cells were injected into mice with cecal ligation and puncture (CLP)-induced sepsis, and the enhanced expression of IL-10 in blood was confirmed by ELISA. Indeed, in CLP mice mode, the systematic delivery of IL-10 via BMSCs effectively suppressed the production of proinflammatory cytokines, including TNF-α, IL-6, IL-1α and IL-1β, compared to BMSCs alone. The therapeutic benefits were further demonstrated by an increased prevention from body loss, increased survival rate, and the suppression of inflammatory response in lung and kidney. Furthermore, these effects may be mediated by inhibiting the activation of NF-κB in macrophages and neutrophils. Collectively, these results suggest that systemic delivery of IL-10 by BMSCs may serve as a potential treatment in sepsis therapy.

Abstract:As an important hormone, melatonin has a wide range of functions in human body. Inappropriate light at night (LAN) will cause abnormal human circadian rhythm and then lead to melatonin secretion suppression. Melatonin suppression depends on correlated color temperature (CCT) and wavelengths of LAN. So far there was no quantitative algorithm for melatonin suppression by LAN. A relative spectral sensitivity curve of human plasma melatonin suppression was fitted and an algorithm was presented for predicting melatonin suppression by LAN. Theoretical basis and a method were provided for instructing safety strategy of architectural light at night. Also, the results could be applied in controlling light pollution, formulating the standard of safety nocturnal environment illumination and some other fields.