Studies on mechanism for Initial Responses to Stress in Cells

以前，我们发现热休克应激迅速诱导人成纤维细胞中的甾醇葡萄糖苷（SG），并假设SG作为一个重要的脂质介质在细胞应激反应的过程中发挥作用。本研究探讨了SG对大鼠冷束缚应激性胃溃疡的保护作用。(1)It结果表明，冷束缚应激诱导胆固醇葡萄糖苷（CG）在胃和肾中的器官特异性蓄积。(2)A在大鼠胃匀浆中检测CG生物合成酶活性。该酶是一种膜结合葡糖基转移酶，其使用UDP-葡萄糖和胆固醇作为底物。（3）应激前口服CG可明显抑制大鼠胃溃疡的形成。口服CG引起胃粘膜细胞中HSF 1的快速激活和随后的HSP 70的表达。（4）口服大豆提取物SG也有抗溃疡作用，但未观察到HSP的诱导作用，提示CG可能在应激信号转导系统的早期阶段起脂质介导剂的作用，SGs是治疗胃溃疡的有效细胞保护剂。

Previously, we found that heat shock stress rapidly induced sterylglucoside(SG) in human fibroblast cells and hypothesized that SG functions as a crucial lipid mediator in the process of cellular stress responses. In this study, we examined the protective effect of SG against cold-restraint stress-induced gastric ulcer in rats.(1)It was shown that cold-restraint stress induced the organ-specific accumulation of cholesterylglucoside(CG) in stomach and kidney.(2)A biosynthetic enzyme activity of CG was detected in homogenates of rat stomach. The enzyme was a membrane-bound glucosyltransferase, which uses UDP-glucose and cholesterol as substrates.(3)When CG was orally administered to rat prior to the stress application, the formation of gastric ulcer was markedly suppressed as compared to control. Orally administered CG caused the rapid activation of HSFl and the subsequent expression of HSP70 in gastric mucous cells.(4)Oral administration of SG derived from soy bean also showed the untiulcer effect, although no HSP induction was observed.These findings suggest that CG may act as a lipid mediator in an early stage of the stress signal transduction system and that SGs are effective cytoprotective agents for medical treatment of gastric ulcer.