Cynandione A mitigates ischemic injuries in rats with cerebral ischemia

Cynandione A, an acetophenone from the roots of Cynanchum auriculatum and other species in the genus attenuates neurotoxicity of a variety of neurotoxic agents such as l-glutamate in vitro. In this study, we sought to further characterize the neuroprotective effects of cynandione A and other acetophenones from the roots of C. auriculatum in pheochromocytoma tumor cell line PC12 and investigate whether cynandione A protected against ischemic injuries in rats with experimentally induced cerebral ischemia. Viability assays using the 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophen-yl)-2H-tetrazolium monosodium salt method and lactate dehydrogenase (LDH) release assays showed that cynandione A dose-dependently attenuated glutamate-induced cytotoxicity. Comparative proteomic analysis by two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization-time of flight MS/MS of PC12 cells treated with cynandione A showed 10 μM cynandione A caused broad changes in protein expression in PC12 cells including down-regulation of high mobility group box 1 (HMGB1) and dihydropyrimidinase-like 2 (DPYSL2). Immunoblotting studies showed that 10 μM cynandione A aborted glutamate-induced increase in DPYSL2 and HMGB1 levels in PC12 cells and 30 mg/kg cynandione A also attenuated the rise in HMGB1 levels and mitigated DPYSL2 cleavage in brain tissues of rats with cerebral ischemia. Furthermore, rats with cerebral ischemia treated with 30 mg/kg cynandione A exhibited markedly improved neurological deficit scores at 24 and 72 h compared with control and a 7.2% reduction in cerebral infarction size at 72 h (p < 0.05 vs. control). Our findings demonstrated that cynandione A mitigated ischemic injuries and should be further explored as a neuroprotective agent for ischemic stroke.     

Inhibition of Filamin-A Reduces Cancer Metastatic Potential

Filamin-A cross-links actin filaments into dynamic orthogonal networks, and interacts with an array of proteins of diverse cellular functions. Because several filamin-A interaction partners are implicated in signaling of cell mobility regulation, we tested the hypothesis that filamin-A plays a role in cancer metastasis. Using four pairs of filamin-A proficient and deficient isogenic cell lines, we found that filamin-A deficiency in cancer cells significantly reduces their migration and invasion. Using a xenograft tumor model with subcutaneous and intracardiac injections of tumor cells, we found that the filamin-A deficiency causes significant reduction of lung, splenic and systemic metastasis in nude mice. We evaluated the expression of filamin-A in breast cancer tissues by immunohistochemical staining, and found that low levels of filamin-A expression in cancer cells of the tumor tissues are associated with a better distant metastasis-free survival than those with normal levels of filamin-A. These data not only validate filamin-A as a prognostic marker for cancer metastasis, but also suggest that inhibition of filamin-A in cancer cells may reduce metastasis and that filamin-A can be used as a therapeutic target for filamin-A positive cancer.     

不产桔霉素的红曲霉菌种深层发酵生产莫纳可林K

对三株在YES培养基中不产桔霉素的红曲霉菌种,在摇瓶中研究了它们液体发酵生产莫纳可林K的情况。在大米粉培养基中,红色红曲霉不产莫纳可林K,但是紫色红曲霉和烟灰色红曲霉均能产莫纳可林K,前者产量高于后者。在葡萄糖．甘油培养基中,后两者的产量均很低,但是如果在该培养基中添加酵母膏,紫色红曲霉能产生较为可观的莫纳可林K。在2L的发酵罐中,利用添加了酵母膏的葡萄糖-甘油培养基,紫色红曲霉在第13d的莫纳可林K产量可达104mg/L,培养过程中无桔霉素产生。     

Combinatorial signals of activin/nodal and bone morphogenic protein regulate the early lineage segregation of human embryonic stem cells

Cell fate commitment of pre-implantation blastocysts, to either the inner cell mass or trophoblast, is the first step in cell lineage segregation of the developing human embryo. However, the intercellular signals that control fate determination of these cells remain obscure. Human embryonic stem cells (hESCs) provide a unique model for studying human early embryonic development. We have previously shown that Activin/Nodal signaling contributes to maintaining pluripotency of hESCs, which are derivatives of the inner cell mass. Here we further demonstrate that the inhibition of Activin/Nodal signaling results in the loss of hESC pluripotency and trophoblast differentiation, similar to BMP4-induced trophoblast differentiation from hESCs. We also show that the trophoblast induction effect of BMP4 correlates with and depends on the inhibition of Activin/Nodal signaling. However, the activation of BMP signaling is still required for trophoblast differentiation when Activin/Nodal signaling is inhibited. These data reveal that the early lineage segregation of hESCs is determined by the combinatorial signals of Activin/Nodal and BMP.     

Production and Accumulation of Xylooligosaccharides with Long Chains by Growing Culture and Xylanase of a Mutant Strain of Bacillus pumilus X-6-19

Bacillus pumilus X-6-9 isolated from soil and subsequently identified, produced xylooligosacchatides with long chainsfrom xylan and accumulated them in the culture. By improving the culture conditions and mutating the bacterium, a 3.2-fold increasein the production of the xylooligosaccharides was established, when compared to the original culture conditions of B. pumilus X-6-19.The addition of D-glucose to the culture of the mutant swain U-3 of B. pumilus X-6-9 repressed the synthesis of β-xylosidase, but notxylanase. Thus, it was revealed that strain U-3 was a good organism for the production and accumulation of xylooligosaccharideswith long chains from xylan by a microbial culture. Xylanase produced by strain U-3 was purified to homogeneity and characterized.The hydrolyzates generated by the purified xylanase contained xylobiose, xylotrinse, xylotewaose, and xylopentaose, but not xylose.     

HCV E2蛋白诱导的体液免疫及CTL应答研究

应用PCR方法扩增出HCVE2基因编码417a．a-750a．a的DNA片段,克隆到原核表达载体pQE30 LacZ启动子下游,转化JM109菌株。在JM109菌株中诱导表达出N端含6个组氨酸的E2融合蛋白,用Ni-NTA-Superflow亲和层析柱纯化作为抗原免疫实验兔和BALB／c鼠。定期取兔血,采用间接ELISA方法检测兔子体内针对E2的抗体水平和维持规律。结果显示,距初次免疫14d兔子体内已有抗体产生,直至免疫第55d抗体水平持续上升,之后抗体水平保持稳定,抗体滴度达到1：3200。六周后,取鼠脾脏制各淋巴细胞,定向刺激扩增后与经过重组真核表达质粒pCE2转染的P815细胞作用,利用LDH释放试验检测作用效果。在E：T＝200：1的情况下,杀伤率超过30％。这些结果表明工程菌株表达的HCVE2蛋白具有良好的免疫原性,可以诱发免疫实验动物机体产生较高滴度的抗体及特异性CTL应答。由此我们认为E2蛋白是发展HCV预防工程蛋白疫苗的合适候选者。     

PNAS-4 expression and its relationship to p53 in colorectal cancer

PNAS-4 is a novel pro-apoptotic protein activated during the early response to DNA damage; however, the molecular mechanisms and pathways regulating PNAS-4 expression in tumors are not well understood. We hypothesized that PNAS-4 is a p53 down-stream target gene and designed this study. We searched online for putative p53-binding sites in the entire PNAS-4 gene and did not find any corresponding information. In HCT116 colon cancer cells, after being transfected with small interfering RNA to silence p53, the expressions of PNAS-4 and other known p53 target gene (Apaf1, Bax, Fas and Dr5) were determined by real-time PCR. We found that PNAS-4 was up-regulated while Apaf1, Bax, Fas and Dr5 were down-regulated. We then examined the expression of PNAS-4 and p53 mutation in colorectal cancer patients. PNAS-4 expressed both in colorectal cancers and normal tissues, but compared with paired control, PNAS-4 was up-regulated in cancers (P = 0.018). PNAS-4 overexpression ratios were correlated to the p53 mutant status (P = 0.001). The mean PNAS-4 expression levels of p53 mutant homozygote group and heterozygote group were higher than that of p53 wild type group (P = 0.013). The expression ratios of PNAS-4 (every sample in relative to its paired normal mucosa) were different between negative lymph node metastasis (66% up-regulated, 34% down-regulated) and positive metastasis (42% up-regulated, 58% down-regulated). Taken together, these findings suggested that PNAS-4 was not a p53 target, but overexpression of PNAS-4 was correlated to p53 inactivity in colorectal cancer.     

南沙群岛西南部和北部湾口海域鱼类物种多样性

根据2012-2013年在南沙群岛西南部和北部湾口海域春秋两个航次的调查资料, 分析了该海域鱼类种类组成、相对重要性指数和物种多样性等特征。结果表明, 两个航次调查共鉴定鱼类504种, 隶属于2纲31目129科294属; 其中北部湾口海域出现鱼类301种, 南沙群岛西南部海域出现鱼类357种。优势种数量较少, 多以中小型鱼类为主, 且季节间变化较大。春季多样性指数高于秋季, 这主要是因为春季出现的大量鱼类为补充群体, 而许多种类在秋季有向较深海区移动的趋势; 南沙群岛西南部海域多样性指数高于北部湾口海域, 这主要是由于南沙群岛西南部海域受水温和洋流的影响较大造成的。更替指数和迁移指数显示, 秋季鱼类群落结构稳定性要低于春季, 而且两个季节的鱼类群落结构都偏离平衡状态, 主要是由鱼类的洄游和不同适温性鱼类的迁入迁出造成的。综合来看, 南沙群岛西南部海域鱼类物种多样性和群落结构稳定性均高于北部湾口海域, 在努力控制资源可捕量范围的同时, 可合理开发南海中南部海域的渔业资源。     

鳜鱼外周血细胞显微和亚显微结构的观察

本文报道了鳜鱼外周血细胞的显微和亚显微结构。血涂片经过染色,可鉴别出红细胞、血栓细胞、淋巴细胞、单核细胞和嗜中性粒细胞;还见到幼稚的正在分裂的红细胞,提示红细胞亦可在外周血液中通过直接分裂产生。白细胞中,血栓细胞体积最小,嗜中性粒细胞体积最大;单核细胞数目最少,血栓细胞数目最多。电镜下,红细胞中可见线粒体和高尔基复合体;淋巴细胞线粒体中可见类似髓样体的板层状结构;血栓细胞和单核细胞与其它鱼类的基本