Tissue Kallikrein, Oxidative Stress and Renal Fibrosis

组织激肽释放酶、氧化应激和肾纤维化

• 批准号: 6894827
• 负责人: JULIE CHAO
• 金额: $ 28.91万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6894827
• 关键词: RNA interference; angiotensin /renin /aldosterone hypertension; apoptosis; biological signal transduction; cell morphology; cell proliferation; chronic renal failure; dietary sodium; enzyme activity; enzyme mechanism; extracellular matrix; fibrosis; inflammation; interstitial; kallikreins; kidney function; kinins; laboratory rat; nephrosclerosis; oxidative stress; pathologic process; sodium chloride; tissue /cell culture

DESCRIPTION (provided by applicant): The objective of this proposal is to study the role and signaling mechanisms by which the kallikreinkinin system (KKS) protects against salt-induced nephrosclerosis. The long-term goal is to develop novel therapeutic targets in the treatment and prevention of chronic renal disease and end-stage renal failure. Renal kallikrein levels are markedly reduced in humans and animal models with renal disease. By linkage analysis, we showed an association of a promoter polymorphic allele in the human tissue kallikrein gene with salt-induced hypertension and end-stage renal failure, as well as with blood pressure responses to changes in dietary sodium restriction. These findings implicate an important role of the KKS in salt-sensitive hypertension and renal function. Indeed, our preliminary studies show that elevated kallikrein/kinin levels (following kallikrein gene transfer) results in suppression of salt-induced inflammatory cell infiltration, glomerular enlargement, apoptosis, cell proliferation and collagen content in Dahl salt-sensitive (DS) rats. These protective effects were accompanied by increased nitric oxide (NO) levels and reduced oxidative stress and TGF-beta expression. Based on these findings, we hypothesize that the KKS through NO formation prevents and reverses salt-induced nephrosclerosis through inhibition of oxidative stress-induced signaling pathways. The following Specific Aims will be pursued to determine the signaling mechanisms that mediate the protective effects of the KKS in: 1) interstitial inflammation, 2) apoptosis, 3) proliferation and hypertrophy and 4) extracellular matrix accumulation leading to fibrosis. The signaling mechanisms may involve MCP-1, VCAM-1, ICAM-1, NF-kappaB, TGF-beta, MAPK, PA/MMP, PI3-kinase/Akt and p21/p27kip1. Enhanced kallikrein levels will be achieved by kallikrein gene delivery and kallikrein protein infusion into a salt-dependent hypertensive rat model. Cellular signaling pathways will be dissected in cultured endothelial and renal cells using specific inhibitors, neutralizing antibodies, dominant-negative DNA constructs, and small interference RNA. These studies should provide novel and in-depth information regarding the role of kallikrein/kinin in prevention and reversal of inflammation, apoptosis, proliferation, hypertrophy, and fibrosis that contribute to salt-induced nephrosclerosis.

描述（由申请人提供）：本提案的目的是研究激肽释放酶系统（KKS）保护盐诱导的肾硬化的作用和信号机制。长期目标是开发治疗和预防慢性肾脏疾病和终末期肾衰竭的新治疗靶点。 在患有肾脏疾病的人类和动物模型中，肾脏激肽释放酶水平显著降低。 通过连锁分析，我们发现了人类组织激肽释放酶基因启动子多态性等位基因与盐诱导的高血压和终末期肾功能衰竭，以及与饮食钠限制变化的血压反应相关。 这些发现暗示了KKS在盐敏感性高血压和肾功能中的重要作用。事实上，我们的初步研究表明，升高的激肽释放酶/激肽水平（以下激肽释放酶基因转移）的结果抑制盐诱导的炎性细胞浸润，肾小球扩大，细胞凋亡，细胞增殖和胶原蛋白含量在达尔盐敏感（DS）大鼠。 这些保护作用伴随着一氧化氮（NO）水平的增加和氧化应激和TGF-β表达的减少。 基于这些发现，我们假设KKS通过NO的形成，通过抑制氧化应激诱导的信号通路，防止和逆转盐诱导的肾硬化。将追求以下特定目的，以确定介导KKS在以下方面的保护作用的信号传导机制：1）间质性炎症，2）细胞凋亡，3）增殖和肥大，以及4）导致纤维化的细胞外基质蓄积。其信号转导机制可能涉及MCP-1、VCAM-1、ICAM-1、NF-κ B、TGF-β、MAPK、PA/MMP、PI 3-kinase/Akt和p21/p27 kip 1。 通过将激肽释放酶基因递送和激肽释放酶蛋白输注到盐依赖性高血压大鼠模型中，将实现激肽释放酶水平的增强。将使用特异性抑制剂、中和抗体、显性阴性DNA构建体和小干扰RNA在培养的内皮细胞和肾细胞中剖析细胞信号传导途径。这些研究应提供关于激肽释放酶/激肽在预防和逆转炎症、凋亡、增殖、肥大和纤维化中的作用的新颖和深入的信息，这些炎症、凋亡、增殖、肥大和纤维化有助于盐诱导的肾硬化。