生物信息大分子功能的研究——酵母甘露聚糖对鼠Sarcoma-180瘤生长的抑制效应

酵母甘露聚糖（Mannan,简称Man）是能参与生物信息流影响生物体、特别是在糖基化方面起着重要调控作用的生物信息大分子.它是否能在抑制生物机体中肿瘤生长方面具有重要作用？研究结果表明：酵母甘露聚糖既能使患S-180瘤鼠的体质增强的同时又有抑制其体内所患S-180瘤生长的功效.Man抑制患鼠机体内的S-180瘤生长的功效（抑瘤率）随用量的增加而提高,当Man用量达360 mg（40 mg/Kg/d·9d）时,其抑瘤率达98.4％的最高水平,此时鼠体重增加1.66倍.Man的抑瘤功效有最佳适用量并存在性别敏感性,通常是雄性鼠的抑瘤率高于雌性鼠.Man抑制鼠S-180肿瘤生长的作用优于市售5-氟尿嘧啶的作用.     

双向电泳结合质谱分析长双歧杆菌XY01分泌蛋白质图谱

菌体的分泌蛋白质在宿主和菌体的相互作用之间起着重要的作用. 本研究采用双向凝胶电泳的方法建立了长双歧杆菌XY01分泌蛋白质图谱,通过MALDI-TOF/TOF质 谱鉴定和数据库搜索,对鉴定到的分泌蛋白进行了分析. 共检测到21个蛋白质点, 成功鉴定18个蛋白质点,分别代表14个不同的蛋白质,等电点分布在4.5～7.0之间 ,分子质量分布在20 ～65 kD之间;通过COGs分类和功能分析,信号肽和细胞定位及KEGG代谢通路分析. 结果表明,这些蛋白质对菌体细胞壁/膜的形成、生物信号传导和物质代谢等起着重要作用. 研究结果为长双歧杆菌蛋白质组学和基因组学的研究提供了参考.     

组蛋白激活拟南芥CDPK催化CaMBP10的体外磷酸化反应

植物转脂蛋白 (plant lipid transfer proteins, LTPs) 是高等植物中广泛存在的多基因编码的小分子碱性蛋白. 本研究室已经证明白菜和豌豆LTPs可分别被内源胞浆可溶性和膜结合钙依赖性蛋白激酶 (calcium-dependent protein kinase, CDPK) 磷酸化. 为深入研究CDPK对白菜钙调素结合蛋白10 (calmodulin-binding protein-10, CaMBP10) 的磷酸化性质及特征, 本文从拟南芥可溶性蛋白粗提物中检测到1个分子量约为54 kD的CDPK对CaMBP10有磷酸化作用. 研究表明, 组蛋白可增强 CDPK对CaMBP10的磷酸化活性, 促进磷酸化进程. 而且组蛋白和Ca2+对CDPK具有协同调节效应, 二者共同作用时比Ca2+单独作用时, 激酶的活力增强约12倍. 此外, 不同组蛋白对CDPK的激活能力不同, 组蛋白1对该激酶活性的激活能力要比组蛋白3高约8倍.     

Gene cloning and functional analysis of yellow green leaf3 (ygl3) gene during the whole-plant growth stage in rice

Chlorophyll is an important photosynthetic pigment in the process of photosynthesis in plants and photosynthetic bacteria. Genes involved in chlorophyll biosynthesis in Arabidopsis and photosynthetic bacteria have been well documented. In rice, however, these genes have not been fully annotated. In this paper, a yellow-green leaf gene, yellow green leaf3 (ygl3) was cloned and analyzed. ygl3 encodes magnesium chelation ChlD (D) subunit, a key enzyme for chlorophyll synthesis, resulting in a yellow-green leaf phenotype in all growth stages in rice. Expression content of ygl3 is highest in the leaf blades, followed by the leaf sheaths, while there is virtually no expression of the gene in the stems and seeds. The sub-cellular structure and protein content of the photosynthetic system of the ygl3 mutant were revealed by transmission electron microscopy, BN-PAGE, and western blotting. The results show that the mutation of the ygl3 gene indirectly leads to a decrease in the protein content of the photosynthetic system and severely obstructs the formation of granum thylakoids.     

Activation of TLR4 signaling promotes gastric cancer progression by inducing mitochondrial ROS production

Chronic infection, such as Helicobacter pylori infection, has been associated with the development of gastric cancer (GC). Pathogen-associated molecular patterns can trigger inflammatory responses via Toll-like receptors (TLRs) in GC. Here we showed that Toll-like receptor 4 (TLR4) was highly expressed in GC cells and was associated with the aggressiveness of GC. The binding of lipopolysaccharide (LPS) to TLR4 on GC cells enhanced proliferation without affecting apoptosis. Higher level of reactive oxygen species (ROS) was induced after activation of TLR4 signaling in GC. Using oxidase inhibitors and antioxidants, we found that mitochondrial ROS (mROS) was major source of TLR4-stimulated ROS generation. This elevated mROS production can be inhibited by diphenylene iodonium (DPI), and the blocking of the mROS production rather than ROS neutralization resulted in cell cycle arrest and the loss of mitochondrial potential, which were plausible reason for decreased cell viability. Furthermore, the increased mROS owing to TLR4 signaling resulted in the activation of Akt phosphorylation and NF-κB p65 nuclear translocation. Altogether, these results reveal a novel pathway linking innate immune signaling to GC cell proliferation, implicate mROS as an important component of cell survival signals and further establish mitochondria as hubs for GC therapies.     

Protein Phosphatase 2A Catalytic Subunit α Plays a MyD88-Dependent,Central Role in the Gene-Specific Regulation of Endotoxin Tolerance

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Highlights? PP2Ac is constitutively activated and targets MyD88 in LPS-tolerized macrophages ? Constitutively active PP2Ac shifts a proinflammatory MyD88 to its prosurvival mode ? Constitutively active PP2Ac reprograms gene-specific chromatin modification landscape ? Constitutively active PP2Ac broadly defines ET at both signaling and epigenetic levels     

A New Species of the Genus Leptolalax(Anura: Megophryidae) from Northern Thailand

A new species of the genus Leptolalax is described from Doi Saket, Chiang Mai Province, northern Thailand. The new species is distinguished from its congeners by the following combination of characters: 1) adult size large(male SVL 45.8-52.5 mm); 2) tympanum distinct; 3) skin of dorsal surface mostly smooth, with distinct tubercles on dorsal and lateral parts of the body; 4) ventrolateral glandular ridge distinct and complete; 5) lateral body and groin covered with dark brown or black spots; 6) throat, chest, and belly nearly immaculate white; and 7) bi-colored iris, upper onethird golden, and lower two-thirds gray. Molecular phylogenetic analysis of mitochondrial 16S rRNA further distinguishes it from its congeners for which sequences are available.     

Expansion of mesenchymal stem cells under atmospheric carbon dioxide

Stem cells are needed for an increasing number of scientific applications, including both fundamental research and clinical disease treatment. To meet this rising demand, improved expansion methods to generate high quantities of high quality stem cells must be developed. Unfortunately, the bicarbonate buffering system – which relies upon an elevated CO₂ environment – typically used to maintain pH in stem cell cultures introduces several unnecessary limitations in bioreactor systems. In addition to artificially high dissolved CO₂ levels negatively affecting cell growth, but more importantly, the need to sparge CO₂ into the system complicates the ability to control culture parameters. This control is especially important for stem cells, whose behavior and phenotype is highly sensitive to changes in culture conditions such as dissolved oxygen and pH. As a first step, this study developed a buffer to support expansion of mesenchymal stem cells (MSC) under an atmospheric CO₂ environment in static cultures. MSC expanded under atmospheric CO₂ with this buffer achieved equivalent growth rates without adaptation compared to those grown in standard conditions and also maintained a stem cell phenotype, self‐renewal properties, and the ability to differentiate into multiple lineages after expansion. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:1298–1306, 2013     

陕西省烟草灰霉病病原及云芝多糖对其防治研究

采用形态学观察和分子鉴定方法对2011年在陕西省发生的一种烟草未知病害的病原菌进行鉴定。从病叶组织分离纯化得到病原菌,通过致病性测定以及人工接种后再分离病菌,证明编号LJL007的菌株为该病的致病菌。依据病原菌的形态学和培养特征,将菌株LJL007鉴定为灰葡萄孢Botrytis cinerea Pers.,其有性型为富氏葡萄孢盘菌Botryotinia fuckeliana Whetzel。通过核糖体DNAITS序列分析,分离菌株LJL007序列(登录号:HM17900)与富氏葡萄孢盘菌序列(登录号:HM849615)同源性达100%,进一步证明该病原菌是灰葡萄孢Botrytis cinerea。云芝多糖在离体条件下,对灰葡萄孢的菌丝生长和孢子萌发均无直接抑制作用。云芝多糖对烟草灰霉病有较好预防保护作用,其预防效果可达56.29%。云芝多糖可显著提高烟草体内几丁质酶和β-1,3-葡聚糖酶活性,其活性峰值分别比对照提高56.89%和429.83%,说明云芝多糖可诱导植物产生抗病性。     

An Efficient Rice Mutagenesis System Based on Suspension-Cultured Cells

Plant mutants are important bio-resources for crop breeding and gene functional studies. Conventional methods for generating mutant libraries by mutagenesis of seeds with physical or chemical agents are of low efficiency. Here, we developed a highly-efficient ethyl methanesulfonate (EMS) mutagenesis system based on suspension-cultured cells, with rice (Oryza sativa L.) as an example. We show that treatment of suspension-cultured tiny cell clusters with 0.4% EMS for 18-22h followed by differentiation and regeneration produced as high as 29.4% independent mutant lines with visible phenotypic variations, including a number of important agronomic traits such as grain size, panicle size, grain or panicle shape, tiller number and angle, heading date, male sterility, and disease sensitivity. No mosaic mutant was observed in the mutant lines tested. In this mutant library, we obtained a mutant with an abnormally elongated uppermost internode. Sequencing and functional analysis revealed that this is a new allelic mutant of eui (elongated uppermost internode) caused by two point mutations in the first exon of the EUI gene, representing a successful example of this mutagenesis system.