Anion channel regulation of vascular superoxide signaling in hypertension

高血压血管超氧化物信号传导的阴离子通道调节

基本信息

批准号：
10642865
负责人：
FRED S LAMB
金额：
$ 69.62万
依托单位：
VANDERBILT UNIVERSITY MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-06-15 至 2026-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10642865
关键词：
Angiotensin II Anions Antioxidants Apoptosis Binding Biological Biological Assay Blood Pressure Blood Vessels Cardiovascular Diseases Cause of Death Cells Compensation Cytoplasm Disease Endocytosis Environment Exhibits Family Feedback Free Radicals Goals Hydrogen Peroxide Hypertension Hypertrophy Impairment Inflammation Inflammatory Infusion procedures Knockout Mice Leucine-Rich Repeat Link Mass Spectrum Analysis Medial Mesentery Methods Molecular Monomeric GTP-Binding Proteins Mus Myocardial Ischemia Myography NADPH Oxidase 1 Nitric Oxide Oxidants Oxidation-Reduction Oxidative Stress Pathology Pathway interactions Perfusion Permeability Peroxonitrite Physiological Production Proliferating Property Protein Family Protein Isoforms Proteins Reactive Nitrogen Species Reactive Oxygen Species Regulation Relaxation Resistance Risk Factors Role Scaffolding Protein Signal Pathway Signal Transduction Signaling Molecule Smooth Muscle Myocytes Stroke Superoxides TNF gene TNFRSF1A gene Vascular Diseases Vascular Smooth Muscle Vasodilation Vasodilator Agents Vasomotor Work antioxidant enzyme antioxidant therapy channel blockers chronic inflammatory disease constriction cytokine defined contribution experimental study extracellular hypertension treatment insight knock-down migration myosin phosphatase novel novel therapeutic intervention oxidation patch clamp pressure public health relevance response selective expression spatiotemporal treatment strategy ubiquitin-protein ligase vascular inflammation vasoactive agent

项目摘要

PROJECT SUMMARY Hypertension (HTN) is a chronic inflammatory disease and is a primary risk factor for ischemic heart disease and stroke, the two leading causes of death worldwide. HTN is associated with vascular “oxidative stress”, yet antioxidant therapy has not proven effective. This may be because reactive oxygen species (ROS) also participate in normal physiological signaling by molecules like Angiotensin II (AngII) and tumor necrosis factor α (TNFα). Pathology may result from excess activation, loss of spatiotemporal constraints, or dysregulation of the feedback mechanisms that control these signals. AngII and TNFα both activate NADPH Oxidase 1 (Nox1), producing extracellular superoxide (O2-•). By an unknown mechanism, this generates an intracellular signal, and disruption of this protects against vascular inflammation and AngII-induced HTN. We previously found that Nox1 physically associates with Volume-Regulated Anion Channels (VRACs) that are encoded by Leucine-Rich Repeat-Containing 8 family proteins. LRRC8A associates with one of four related isoforms (LRRC8B-E) to produce channels with unique properties. ROS production by Nox1 requires functional VRACs, potentially for change compensation, and the oxidized environment created by Nox1 regulates VRACs. Thus, VRACs and Nox1 are functionally interdependent. We now provide new evidence that O2-• also enters cells via these closely associated anion channels. This may allow tight regulation of O2-• delivery to the cytoplasm, providing spatial control of redox signaling which limits off-target oxidation. Blood vessels from mice lacking LRRC8A only in vascular smooth muscle cells (VSMCs) exhibit normal contractility but enhanced vasodilation and these mice are protected from AngII-induced HTN. We hypothesize that by regulating Nox1 activity and O2-• entry into VSMCs, LRRC8 anion channels control cytoplasmic redox signaling pathways that promote inflammation and impair vasodilation. Aim #1 will determine how LRRC8 channels facilitate O2-• influx into VSMCs and determine how this is regulated by local redox conditions. We will use two novel O2-• flux assays that we have developed combined with patch-clamp recording to achieve these goals. Aim #2 will determine how LRRC8A channels and O2-• modulate inflammation and contractility via two cytoplasmic targets: 1) RhoA, a small GTPase that controls vasomotor function, and 2) TRIM21, an E3 ubiquitin ligase that we identified by mass spectrometry as a novel binding partner of LRRC8A. TRIM21 modulates both NF-κB-dependent inflammation and the Nrf2-dependent antioxidant response. Aim #3 will define the contribution of specific LRRC8 isoforms to AngII-induced hypertension in mice. Blood pressure recording, vascular reactivity and molecular biologic studies will define the LRRC8 channel subtype that controls Nox1 and vascular function in HTN . Relevance: Links between inflammation, oxidative stress and cardiovascular disease are clear, but methods to control oxidant-dependent signaling are lacking. This project will identify novel therapeutic strategies that are applicable to the treatment of HTN and vascular inflammation.

项目概要高血压（HTN）是一种慢性炎症性疾病，是缺血性心脏的主要危险因素高血压和中风是全球两大死亡原因，与血管“氧化”有关。压力”，但抗氧化疗法尚未被证明有效，这可能是因为活性氧（ROS）。还参与血管紧张素 II (AngII) 等分子的正常生理信号传导和肿瘤坏死病理学可能是由于过度激活、时空限制丧失或控制这些信号的反馈机制的失调都会激活 NADPH。氧化酶 1 (Nox1)，通过未知机制产生细胞外超氧化物 (O2-•)。细胞内信号，破坏该信号可以防止血管炎症和 AngII 诱导的高血压。我们之前发现 Nox1 与容量调节阴离子通道 (VRAC) 物理关联，由富含亮氨酸重复序列的 8 个家族蛋白编码，与四种蛋白之一相关。 Nox1 需要相关亚型 (LRRC8B-E) 来产生具有独特特性的 ROS 生产通道。功能性 VRAC，可能用于变化补偿，以及 Nox1 产生的氧化环境因此，VRAC 和 Nox1 在功能上是相互依赖的。 O2-• 也通过这些密切相关的阴离子通道进入细胞，这可能允许严格调节O2-•。递送到细胞质，提供氧化还原信号的空间控制，限制脱靶氧化。仅血管平滑肌细胞 (VSMC) 中缺乏 LRRC8A 的小鼠的血管表现正常收缩力但血管舒张增强，并且这些小鼠免受 AngII 诱导的 HTN 的影响。通过调节Nox1 活性和O2-• 进入VSMC，LRRC8 阴离子通道控制细胞质促进炎症和损害血管舒张的氧化还原信号通路将决定如何进行。 LRRC8 通道促进O2-• 流入VSMC，并决定如何通过局部氧化还原条件对其进行调节。我们将使用我们开发的两种新颖的 O2-• 通量测定法与膜片钳记录相结合来实现这些目标#2 将确定LRRC8A 和O2-• 如何通过调节炎症和收缩性。两个细胞质靶标：1) RhoA，一种控制血管舒缩功能的小 GTP 酶，2) TRIM21，一种 E3 我们通过质谱分析鉴定出泛素连接酶是 LRRC8A 的新型结合伴侣。调节 NF-κB 依赖性炎症和 Nrf2 依赖性抗氧化反应。目标 #3 定义特定 LRRC8 异构体对 AngII 诱导的小鼠高血压的影响。记录、血管反应性和分子生物学研究将定义 LRRC8 通道亚型控制 HTN 中的 Nox1 和血管功能。心血管疾病的发病机制已明确，但该项目缺乏控制氧化剂依赖性信号传导的方法。将确定适用于治疗高血压和血管炎症的新治疗策略。