PROTEIN KINASE C IN ISCHEMIC RENAL INJURY AND REPAIR

蛋白激酶C(PKC)同工酶是一类细胞内的蛋白激酶 通过磷酸化来调节细胞的生长和分化 靶蛋白。PKC在细胞对缺血的反应中发挥作用 在包括肾脏在内的各种组织中。我们已经证明了表达式 几种PKC同工酶与活化C-激酶受体(RACK1)的关系 在缺血性肾损伤后增强。中概述的研究 该提案旨在描述单个PKC的角色 实验性急性肾小管再生中的同工酶 采用体外和体内的缺血性肾损伤模型。第一个目标 建议的研究的一部分是将单个PKC同工酶定位为 正在经历再生或死亡的特定细胞。蛋白激酶C测定法 将被执行以确定哪些个体同工酶是 缺血损伤后激活或下调。第二个目标 该提案的目的是确定PKC是否在维护 LLCPK1细胞存活及促进再生的实验研究 氧化损伤。LLCPK1细胞将受到氧化损伤 PKC激活剂和抑制剂的存在及其对细胞的影响 生存能力将被确定。LLCPK1细胞高表达个体 将建立PKC同工酶，这些细胞系将用于 描述个体同工酶在氧化后恢复中的作用 居间伤害。这项建议的第三个目的是研究其影响 蛋白激酶C激活剂和抑制物对大鼠肾脏再生的影响 急性缺血性肾功能衰竭。我们的初步数据显示 大鼠脑缺血前给予PKC激活剂可改善 受伤的过程。这些观察结果将被扩展以测试 不同PKC激活剂和抑制剂对肾功能的影响 细胞形态、细胞增殖、细胞凋亡和分化 缺血症。

Protein kinase C (PKC) isozymes comprise a family of cellular kinases that regulate cell growth and differentiation via phosphorylation of target proteins. PKC plays a role in the cellular response to ischemia in various tissues including kidney. We have shown that the expression of several PKC isozymes and the receptor for activated C-kinase(RACK1) are enhanced following ischemic renal injury. The studies outlined in this proposal are designed to delineate the role of individual PKC isozymes in the tubular regeneration following experimental acute ischemic renal injury using in vitro and in vivo models. The first aim of the proposed research is to localize individual PKC isozymes to particular cells that are undergoing regeneration or death. PKC assays will be performed to determine which of the individual isozymes are activated or down-regulated following ischemic injury. The second aim of the proposal is to determine if PKC plays a role in maintaining cellular viability and promoting regeneration of LLCPK1 cells following oxidant injury. LLCPK1 cells will be subjected to oxidant injury in presence of activators and inhibitors of PKC and their effects on cell viability will be determined. LLCPK1 cells overexpressing individual PKC isozymes will be established and these cell lines will be used to delineate the role of individual isozymes in recovery following oxidant mediated injury. The third aim of the proposal is to study the effect of PKC activators and inhibitors on renal regeneration using a rat model of acute ischemic renal failure. Our preliminary data indicate that administration of PKC activators to rats pre-ischemia ameliorates the course of injury. These observations will be extended to test the effects of various PKC activators and inhibitors on renal function, morphology, cell proliferation, apoptosis and differentiation post- ischemia.