Protective Role of miR-34c in Hypoxia by Activating Autophagy through BCL2 Repression

Hypoxia leads to significant cellular stress that has diverse pathological consequences such as cardiovascular diseases and cancers. MicroRNAs (miRNAs) are one of regulators of the adaptive pathway in hypoxia. We identified a hypoxia-induced miRNA, miR-34c, that was significantly upregulated in hypoxic human umbilical cord vein endothelial cells (HUVECs) and in murine blood vessels on day 3 of hindlimb ischemia (HLI). miR-34c directly inhibited BCL2 expression, acting as a toggle switch between apoptosis and autophagy in vitro and in vivo. BCL2 repression by miR-34c activated autophagy, which was evaluated by the expression of LC3-II. Overexpression of miR-34c inhibited apoptosis in HUVEC as well as in a murine model of HLI, and increased cell viability in HUVEC. Importantly, the number of viable cells in the blood vessels following HLI was increased by miR-34c overexpression. Collectively, our findings show that miR-34c plays a protective role in hypoxia, suggesting a novel therapeutic target for hypoxic and ischemic diseases in the blood vessels.     

自然界斜纹夜蛾核型多角体病毒的基因型多态性

【目的】从基因组序列角度进一步揭示自然界斜纹夜蛾核型多角体病毒（Spodoptera litura nucleopolyhedrovirus, SpltNPV）的基因型多态性。【方法】病毒克隆A5, F1, X3 和 X15分别以活体克隆法分离自SpltNPV埃及株、 日本福冈株和日本小笠原株。根据SpltNPV基因组全序列（GenBank登录号: AF325155）和海灰翅夜蛾核型多角体病毒（S. littoralis NPV, SpliNPV）部分基因序列（GenBank登录号: X99377, X99376 和X98924）设计引物, PCR扩增获得A5, F1, X3 和 X15的多角体蛋白（polyhedrin, polh）基因和ORF18~ORF23序列。【结果】根据多角体蛋白基因序列, X3和X15属于SpltNPV型, 而A5和F1属于SpliNPV型。将A5, F1, X3 和 X15的ORF18~ORF23与SpltNPV和SpliNPV相应的基因序列进行同源性比较。结果发现, F1与SpliNPV以及X3与SpltNPV的核苷酸序列相似性高, 但X3的ORF20在172~558 nt处缺失387 bp。尽管依据多角体蛋白基因序列X15属于SpltNPV型, 但对于ORF18~ORF23序列, X15与SpliNPV的相似性高于与SpltNPV的相似性。同样, A5属于SpliNPV型, ORF18~ORF20与SpliNPV相应的核苷酸序列相似性高, 但ORF21与SpltNPV相应的核苷酸序列一致性为100%, 特别是ORF22, SpltNPV的特有序列出现在A5的基因组中, 而且与SpltNPV的ORF22一致性为100%; 反过来, ORF23又与SpliNPV相应的核苷酸序列相似性高。【结论】所有这些都表明, SpltNPV在自然界不仅存在基因型多态性, 而且即使属于同一基因型, 它们的基因组序列也有显著差异。可利用SpltNPV在自然界的这种异质性筛选适宜防治斜纹夜蛾幼虫的株系。     

RIP3 blockade prevents immune-mediated hepatitis through a myeloid-derived suppressor cell dependent mechanism

Autoimmune hepatitis (AIH) is an immune-mediated chronic inflammatory liver disease, and its pathogenesis is not fully understood. Our previous study discovered that receptor interacting protein kinase 3 (RIP3) is correlated with serum transaminase levels in AIH patients. However, its role and underlying mechanism in AIH are poorly understood. Here, we detected the increased expression and activation of RIP3 in livers of patients and animal models with AIH. The inhibition of RIP3 kinase by GSK872 prevented concanavalin A (ConA)-induced immune-mediated hepatitis (IMH) by reduced hepatic proinflammatory cytokines and immune cells including Th17 cells and macrophages. Further experiments revealed that RIP3 inhibition resulted in an increase in CD11b⁺Gr1⁺ myeloid-derived suppressor cells (MDSCs) with immunoregulatory properties in the liver, spleen, and peripheral blood. Moreover, the depletion of Gr-1⁺ MDSCs abrogated the protective effect and immune suppression function of GSK872 in ConA-induced IMH. Altogether, our data demonstrate that RIP3 blockade prevents ConA-induced IMH through promoting MDSCs infiltration. Inhibition of RIP3 kinase may be a novel therapeutic avenue for AIH treatment.     

Systemic arteriopathy in SIV-infected rhesus macaques (Macaca mulatta)

BACKGROUND: Severe disseminated vasculopathy was observed in two simian immunodeficiency virus (SIV)-infected rhesus macaques (Macaca mulatta). These animals developed clinical signs of AIDS, including lymphadenopathy, weight loss, diarrhea and collapse. RESULTS AND DISCUSSION: Grossly, both animals showed emaciation, lymphadenopathy, vegetations on the mitral valve, renal infarcts and a dilated intestine; one animal had multifocal hemorrhages in multiple organs. Histologically, both cases had disseminated arteriopathy characterized by intimal thickening and fibrosis with varying degrees of vasculitis. The lesion was prominent in the kidney, intestine, pancreas, liver, heart, lymph nodes, spleen and testis. Occasional venules had intimal thickening. Both cases had cytomegalovirus (CMV) infection with intranuclear inclusions, CMV antigen and nucleic acid; some inclusions were observed in endothelial cells within some of the vascular lesions in one of the two. These data suggest that CMV caused the unusual lesions.     

Proteomics in immunity and herpes simplex encephalitis

The genetic theory of infectious diseases has proposed that susceptibility to life-threatening infectious diseases in childhood, occurring in the course of primary infection, results mostly from individually rare but collectively diverse single-gene variants. Recent evidence of an ever-expanding spectrum of genes involved in susceptibility to infectious disease indicates that the paradigm has important implications for diagnosis and treatment. One such pathology is childhood herpes simplex encephalitis, which shows a pattern of rare but diverse disease-disposing genetic variants. The present report shows how proteomics can help to understand susceptibility to childhood herpes simplex encephalitis and other viral infections, suggests that proteomics may have a particularly important role to play, emphasizes that variation over the population is a critical issue for proteomics and notes some new challenges for proteomics and related bioinformatics tools in the context of rare but diverse genetic defects.     

麻疹病毒受体与病毒侵入

麻疹病毒是一种具囊膜的负链RNA病毒,两种主要的囊膜蛋白血凝素蛋白(H)和膜融合蛋白(F)表达在膜表面负责病毒侵入过程中与宿主受体的结合和膜融合过程.病毒囊膜蛋白与受体的相互作用是病毒侵入宿主的关键步骤,决定了病毒感染能力、种属和组织嗜性.因此,囊膜病毒与受体的结合位点往往成为重要的抗病毒药物的靶点.目前已发现的3种麻疹病毒受体包括CD46、SLAM和Nectin-4.以下综述了麻疹病毒受体的特征及在病毒侵入中的作用、麻疹病毒H蛋白与受体的相互作用机制,为抗病毒药物设计及麻疹病毒作为肿瘤治疗性载体的应用提供理论依据.     

扎伊尔埃博拉病毒糖蛋白基因的克隆和表达

埃博拉病毒属丝状病毒科,能引发动物和人出血热症状,人感染后病死率高达90%以上,目前还没有有效预防和治疗的药物和疫苗。近年来,这种烈性传染病病毒传入我国的可能性不断加大,给我国公共卫生应急体系带来新的挑战。本研究针对埃博拉病毒的最主要结构蛋白——糖蛋白(GP),构建了重组原核表达载体pET28a(+)-GP1(33~313aa)、pET28a(+)-GP1(190~313aa)、pET28a(+)-GP2(502~632aa)、pET28a(+)-sGP,以及重组真核表达载体pcDNA3.1(+)-edited GP、pcDNA3.1(+)-GP1、pcDNA3.1(+)-GP。结果表明,GP1(33~313aa)、GP1(190~313aa)和sGP能在大肠埃希菌BL21(DE3)中以包涵体的形式表达,GP、GP1和GP2能在HEK293T细胞中表达,但均不能在BHK21细胞中表达。本研究为进一步探索埃博拉病毒GP的结构和功能及GP抗体制备奠定了基础。     

Synthesis of cyclooctapeptides: constraints analogues of the peptidic neurotoxin, ω‐agatoxine IVB—an experimental point of view

ω‐AGA IVB is an important lead structure when considering the design of effectors of glutamate release inducting P/Q‐type calcium channels. The best route to achieve the analogues possessing the three‐dimensional arrangement corresponding to the native binding loop was the introduction of constraint by ring formation via side chain to side chain lactamization for suitably protected Lys and Glu residues. Since tryptophane residue located at position 14 of this neuropeptide has been suggested as essential for binding, analogues in which this amino acid was replaced by aza‐tryptophane and alanine were synthesized. The synthesis was carried out on various acid‐labile resins (BARLOS chlorotrityl, Rink amide, PEG‐based or Wang resins), by Fmoc strategy. In this paper, we describe optimization of the peptide cyclization with various protecting groups, and on resin or in solution cyclization experimental parameters. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.     

Effect of Electroconvulsive Shock on Mitochondrial Respiratory Chain in Rat Brain

It is well described that impairment of energy production has been implicated in the pathogenesis of a number of diseases. Although several advances have occurred over the past 20 years concerning the use and administration of electroconvulsive therapy (ECT) to minimize its side effects, little progress has been made in understanding its mechanism of action. In this work, our aim was to measure the activities of mitochondrial respiratory chain complexes II and IV and succinate dehydrogenase from rat brain after acute and chronic electroconvulsive shock (ECS). Our results showed that mitochondrial respiratory chain enzymes activities were increased after acute ECS in hippocampus, striatum and cortex of rats. Besides, we also demonstrated that complex II activity was increased after chronic ECS in cortex, while hippocampus and striatum were not affected. Succinate dehydrogenase, however, was inhibited after chronic ECS in striatum, activated in cortex and not affected in hippocampus. Finally, complex IV was not affected by chronic ECS in hippocampus, striatum and cortex. Our findings demonstrated that brain metabolism is altered by ECS.