MOLECULAR MCHANISM OF CYTOSKELETON-MEDIATED STRESS RESPONSE IN GASTRIC MUCOSAL CELLS.

胃粘膜细胞细胞骨架介导的应激反应的分子机制。

基本信息

批准号：
05670481
负责人：
ROKUTAN Kazuhito
金额：
$ 1.28万
依托单位：
SCHOOL OF MEDICINE,THE UNIVERSITY OF TOKUSHIMA
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

项目摘要

Oxodative stress initiates S-thiolation of specific proteins including actin in cultured gastric mucosal cells. This reversible modification of actic has been suggested to play an importent role in preserving microfilament dynamics under oxidative stress. To test a hypothesis that intracellular glutathione may regulate in sensing and signal transduction of stress response, I examined the induction of heat shock proteins (HSPs) in glutathione-depleted gastric cells.When primary cultures of gastric mucosal cells from guinea pigs were exposed to heat (43ﾟC), ethanol, hydrogen peroxide, or diamide, they rapidly synthesized HSPs. Heat stress induced HSP90, HSP72, and HSC73, and ethanol prominently induced HSP60. In addition to these HSPs, hydrogen peroxide and diamide increased in the syntheses of several undefined proteins. None of these proteins were induced by exposure to the stressors, when intracellular glutathione was depleted to less than 10% of control values by pretreatment of cells with DL-buthionine-[S,R]-sulfoximine (BSO). Gel morbility shift assay using a synthetic oligonucleotide coding HSP72 heat shock element did not show any activation of heat shock factor (HSF) in glutathione-depleted cells exposed to heat, and subsequently no accumulation of HSP72 mRNA was detected in the cells. Immunoblot analysis with ant-HSF1 showed that the amount of HSF1 protein was not decreased by treatment with BSO,but the protein was not recovered in nuclear proteins extracted from BSO-pretreated cells. These results suggest that glutathione may serve a role in mucosal protection through the transcriptional activation of heat shock genes in gastric mucosal cells.

氧化应激启动了培养的胃粘膜细胞中肌动蛋白等特定蛋白质的 S-硫醇化，这种可逆的活性修饰在氧化应激下保持微丝动力学方面发挥着重要作用。为了研究应激反应的信号转导，我检查了谷胱甘肽耗尽的胃细胞中热休克蛋白（HSP）的诱导。豚鼠的粘膜细胞暴露于热（43°C）、乙醇、过氧化氢或二酰胺中，它们迅速合成HSP，热应激诱导HSP90、HSP72和HSC73，并且乙醇除了这些HSP之外还显着诱导HSP。过氧化氢和二酰胺在几种未定义的蛋白质的合成中增加，当细胞内时，这些蛋白质都不是由于暴露于应激源而诱导的。使用编码 HSP72 热休克元件的合成寡核苷酸对细胞进行预处理，将谷胱甘肽消耗至对照值的 10% 以下。谷胱甘肽耗尽的细胞受热后热休克因子 (HSF) 被激活，随后用免疫印迹分析在细胞中未检测到 HSP72 mRNA 的积累。 ant-HSF1表明，用BSO处理后，HSF1蛋白的量并未减少，但从BSO预处理的细胞中提取的核蛋白中，该蛋白没有恢复。这些结果表明，谷胱甘肽可能通过转录激活发挥粘膜保护作用。胃粘膜细胞中的热休克基因。