Regulation of Microvascular Function by ROS

ROS对微血管功能的调节

基本信息

批准号：
7218283
负责人：
CHRISTOPHER S WILCOX
金额：
$ 47.4万
依托单位：
GEORGETOWN UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-09-01 至 2011-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7218283
关键词：
Accounting Agonist Angiotensin II Antioxidants Blood Vessels Buffers Calcium Complication Contracts Cuprozinc Superoxide Dismutase Development Endothelin Endothelin-1 Endothelium Enzyme Activators Enzymes Equilibrium Excretory function Figs - dietary Gene Silencing Gene Targeting Generations Genes Homeostasis Hydrogen Peroxide Hypertension Individual Infusion procedures Injection of therapeutic agent Intake Intravenous Kidney Knock-out Knockout Mice Lead Lipids Mediating Mediation Mesentery Metabolism Modeling Molecular Multienzyme Complexes Mus NADP NADPH Oxidase Nitric Oxide Oryctolagus cuniculus Oxidases Oxidation-Reduction Oxidative Stress Pathway interactions Pharmaceutical Preparations Play Principal Investigator Process Prostaglandin-Endoperoxide Synthase Prostaglandins Protein Isoforms Proteins RNA Interference Rate Rattus Reactive Oxygen Species Regulation Relaxation Research Design Research Personnel Resistance Rho-associated kinase Role Role playing therapy Small Interfering RNA Smooth Muscle Myocytes Sodium Chloride Source Superoxide Dismutase Superoxides Testing Thromboxane Receptor Thromboxanes Time Transplantation Tubular formation Up-Regulation Vascular resistance Vasoconstrictor Agents arteriole base cyclooxygenase 1 cyclooxygenase 2 design enhancing factor feeding hemodynamics human CYBA protein in vivo inhibitor/antagonist intravital microscopy kidney vascular structure knockout gene mouse model peroxidation prevent programs receptor research study response rho salt balance vasoconstriction

项目摘要

Low rates of Angiotensin II (Ang II) infusion increase reactive oxygen species (ROS), upregulate key renal components of NADPH oxidase (p22phox, NOX-1) and downregulate EC-SOD. Antioxidant drugs implicate ROS in the development of hypertension, yet the specific roles of renal and systemic ROS in vasoconstriction, salt retention and the mediation by NADPH oxidase, or by reduced SOD-dependent defense in the kidney, are largely undefined. We will study BP homeostasis (telemetric BP), salt handling and sensitivity and microvascular mechanisms in mice (isolated, perfused renal afferent and mesenteric resistance vessels and in vivo intravital microscopy) to explore the roles of an endothelium-derived contracting factor (EDCF) and enhanced VSMC contractility in the microvessels. We will relate these functional studies to ROS, NO, and calcium activity in individual microdissected vessels and pre-glomerular vascular smooth muscle cells. Our primary strategy is the use of knockout models and small interference RNAs (siRNAs) directed at target genes delivered intrarenally to assess specifically renal mechanisms of hypertension. This will be extended with kidney cross-transplantation combined with a cre-lox strategy to knockout genes specifically in VSMC to establish, for the first time, the roles of the kidney and its afferent arterioles in mediating hypertension with ROS. Aim 1 will use the EC-SOD -/- mouse model of stable, sustained microvascular oxidative stress to test the hypothesis that oxidative stress releases endothelin, which acts on type A or B receptors to engage a cyclooxygenase-derived EDCF that activates adjacent VSMCs where contractility is enhanced by a Ca++ sensitizing pathway mediated by rho/rho kinase. Aim 2 will use EC-SOD -/- mice administered siRNA to IC-SOD delivered selectively to the kidney to test the hypothesis that IC-SOD is the major antioxidant defense in the kidney and that its renal deficiency promotes renal vasoconstriction, salt retention, and hypertension. Aim 3 will use normal mice with siRNA to p22phox delivered to the kidney or systemically to test the hypothesis that renal NADPH oxidase mediates increased afferent arteriolar contractility, RVR, salt retention and hypertension with Ang II. These projects are an integrated approach to dissect the roles of ROS in renal microvascular reactivity and salt handling that constitute renal mechanisms of hypertension.

低剂量的血管紧张素 II (Ang II) 输注会增加活性氧 (ROS)，上调关键的肾功能 NADPH 氧化酶（p22phox、NOX-1）的成分并下调 EC-SOD。抗氧化药物牵涉其中 ROS 在高血压发展中的作用，但肾脏和全身 ROS 在高血压发展中的具体作用血管收缩、盐潴留以及 NADPH 氧化酶或 SOD 依赖性减少的介导肾脏的防御，很大程度上是不确定的。我们将研究血压稳态（遥测血压）、盐处理小鼠的敏感性和微血管机制（分离的、灌注的肾传入和肠系膜）阻力血管和体内活体显微镜）探索内皮衍生的作用收缩因子（EDCF）并增强微血管中的 VSMC 收缩性。我们将把这些联系起来对单个显微解剖血管和肾小球前的 ROS、NO 和钙活性进行功能研究血管平滑肌细胞。我们的主要策略是使用淘汰模型和小干扰 RNA (siRNA) 针对肾内递送的靶基因，以评估特定的肾脏机制高血压。这将通过肾交叉移植与 cre-lox 策略相结合来扩展敲除 VSMC 中的基因，首次确定肾脏及其传入神经的作用小动脉通过 ROS 介导高血压。目标 1 将使用稳定、持续的微血管氧化应激的 EC-SOD -/- 小鼠模型来检验氧化应激的假设应激释放内皮素，内皮素作用于 A 型或 B 型受体，与环氧合酶衍生的 EDCF 结合激活邻近的 VSMC，其中 Ca++ 敏化途径介导的收缩性增强 rho/rho 激酶。目标 2 将使用 EC-SOD -/- 小鼠施用 siRNA，将 IC-SOD 选择性地递送至肾来检验 IC-SOD 是肾脏中主要的抗氧化防御及其肾功能的假设缺乏会促进肾血管收缩、盐潴留和高血压。目标 3 将使用普通小鼠将 p22phox 的 siRNA 递送至肾脏或全身，以检验肾 NADPH 的假设氧化酶通过 Ang II 介导传入小动脉收缩力、RVR、盐潴留和高血压的增加。这些项目是剖析 ROS 在肾微血管反应性中的作用的综合方法，盐处理构成高血压的肾脏机制。