Constitutive hsp70 in Ischemia/Reperfusion Protection

缺血/再灌注保护中的组成型 hsp70

• 批准号: 6492688
• 负责人: CHING-YUAN SU
• 金额: $ 22.8万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2005-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6492688
• 关键词: cell line; cytoprotection; genetically modified animals; heat shock proteins; laboratory mouse; mitochondrial membrane; myocardial infarction; myocardial ischemia /hypoxia; oxidative stress; protease inhibitor; proteasome; protein localization; protein protein interaction; protein structure function; proteolysis; reperfusion

DESCRIPTION (Verbatim from the application): Reactive oxygen species (ROS) are formed during reoxygenation of ischemic hearts. These oxygen byproducts may initiate tissue damage. The inability of the myocardium to defend against ROS toxicity may lead to ischemia/reperfusion (I/R) injury. Hence, modulation of cellular stress defenses has a clinical significance regarding myocardial preservation during I/R. The inducible heat shock protein 70 (hsp70) is cardioprotective during I/R. Using H9c2 heart cells, we found that its constitutive isoform (hsc70) is also protective against stress. Furthermore, hsc70 has a lower threshold for redistribution and induction activation by mild priming stress and thus is a suitable candidate for pharmacological manipulation. Hsc70 overexpression stabilizes the membrane during hydrogen peroxide (H2O2) exposure, and a simultaneous increase in hsc70 and hsp70 confers a greater stress protection than individual hsp alone. We postulate that hsc70 alone can protect against I/R injury, and through its interaction with hsp70, this protein affords a marked I/R protection. A proteasome inhibitor, lactacystin, suppressed hsc7O-mediated membrane protection, suggesting that hsc7O overexpression may help membrane preservation by facilitating the turnover of certain stress-modified proteins. To test these hypotheses, both H9c2 cell and transgenic animal models will be employed. We will (1) explore the membrane-stabilization mechanism of hsc70 by demonstrating a redistribution of hsc70 to the plasma or mitochondrial membranes during stress, and examine the resultant change in lipid order; (2) use multiple inhibitors to confirm an involvement of proteolysis in hsc70-mediated protection; (3) examine whether hsc70 overexpression alone protects against I/R-induced myocardial infarction; and (4) study the potential interaction between hsc70/hsp70 to improve stress resistance by examining if these hsps bind and stabilize the same cellular target sites, such as the membrane, during stress. This study may enhance our understanding of the hsc70protective mechanism(s).

描述（逐字化的应用程序）：活性氧（ROS）是 在缺血性心脏的重氧过程中形成。这些氧副产品可能 引发组织损伤。心肌无法防御ROS的能力 毒性可能导致缺血/再灌注（I/R）损伤。因此，调制 细胞应力防御对心肌具有临床意义 在I/R期间保存。诱导热激蛋白70（HSP70）为 I/R期间的心脏保护。使用H9C2心脏细胞，我们发现它 组成型同工型（HSC70）也可以防止应力。此外， HSC70的重新分布和诱导激活的阈值较低 启动应力，因此是药理学的合适候选者 操纵。 HSC70过表达在氢气中稳定膜 过氧化物（H2O2）暴露，HSC70和HSP70同时增加 与单独的HSP相比，赋予更大的压力保护。我们假设 仅HSC70就可以防止I/R受伤，并通过其相互作用 使用HSP70，该蛋白具有明显的I/R保护。蛋白酶体 抑制剂，乳酸，抑制了HSC7O介导的膜保护， 提示HSC7O过表达可以通过 促进某些应激改性蛋白的营业额。测试这些 假设将采用H9C2细胞和转基因动物模型。我们 （1）通过演示探索HSC70的膜稳定机理 HSC70在血浆或线粒体膜中重新分布 压力，并检查脂质顺序的变化； （2）使用多个 抑制剂确认蛋白水解参与HSC70介导的 保护; （3）检查HSC70是否单独保护 I/R诱导的心肌梗塞； （4）研究潜在的相互作用 在HSC70/HSP70之间，通过检查这些HSP来提高压力抗性 结合并稳定相同的细胞靶位点，例如膜， 压力。这项研究可能会增强我们对HSC70Protottecter的理解 机理。