Mechanisms of VEGF modulation of smooth muscle function

VEGF调节平滑肌功能的机制

基本信息

批准号：
7368080
负责人：
Reynold Alexander Panettieri
金额：
$ 34.41万
依托单位：
UNIVERSITY OF PENNSYLVANIA
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：
2006-01-27 至 2009-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7368080
关键词：
1,2-diacylglycerol 4-ethoxymethylene-2-phenyl-2-oxazoline-5-one Address Agonist Allergens Antioxidants Asthma Attenuated Calcium Calmodulin Carbachol Cell Proliferation Cell physiology Chronic Clinical Cultured Cells Data Deposition Development Diglycerides Disruption Endothelial Cells Enzyme Inhibitor Drugs Enzyme Inhibitors Extracellular Matrix Family Generations Growth Factor Guanine Guanine Nucleotide Exchange Factors Guanosine Triphosphate Phosphohydrolases Human Immunoblotting Immunofluorescence Immunologic In Vitro Inositol Laboratories Ligands Light MYLK gene Mediating Mesenchymal Microtubules Modeling Molecular Monomeric GTP-Binding Proteins Mus Muscle function Myosin Light Chains NADPH Oxidase Outcome Pathway interactions Phospholipase C Phosphorylation Principal Investigator Protein Overexpression Proteins Reactive Oxygen Species Regulation Relative (related person)Research Personnel Rho-associated kinase Role Sarcoplasmic Reticulum Smooth Muscle Myocytes Specificity Stress Structure Superoxide Dismutase Testing Transgenic Mice Transgenic Organisms Tubulin Vascular Endothelial Growth Factor Receptor Vascular Endothelial Growth Factors Vascular Permeabilities airway hyperresponsiveness airway inflammation airway remodeling angiogenesis base cytokine in vivo inhibitor/antagonist insight programs receptor respiratory smooth muscle rho rho GTP-Binding Proteins tau Proteins tripolyphosphate

项目摘要

Chronic severe asthma is characterized by airways inflammation and airway hyperresponsiveness (AHR). Cytokines and growth factors promote smooth muscle cell proliferation, deposition of extracellular matrix and microvascular remodeling that are prominent features of airway remodeling. New clinical evidence supports an important role for vascular endothelial growth factor (VEGF), a growth factor that regulates vascular permeability and angiogenesis, as a modulator of airway inflammation and AHR in asthma. We present exciting new data demonstrating that VEGF enhances agonist-induced tracheal ring force generation. VEGF also activates RhoA and Rac1 and induces formation of reactive oxygen species (ROS) in ASM cells. In light of these findings, we hypothesize that VEGF activates the Rho family GTPases in ASM cells, leading to enhanced agonist-induced force generation through disruption of microtubules and formation of ROS. To test these hypotheses, we propose the following specific aims: Aim 1 will define the in vivo effects of VEGF on Rho activation and agonist-induced force generation, using a murine model of allergen-induced airway inflammation or transgenic overexpression of VEGF. The relative efficacy of VEGF receptor-specific ligands to activate Rho, phosphorylate myosin light chain (MLC) and enhance agonist- induced force will be characterized. We will also determine whether VEGF induces calcium sensitization in ASM cells. Aim 2 will determine whether microtubule (MT)disruption mediates VEGF-induced augmentation of force generation induced by agonists. We will determine whether MT disruption or stabilization alters agonist-induced tracheal ring force generation and characterize the effect of VEGF on phosphorylation of the MT-associated protein Tau. Finally, we will determine whether Rho activation is necessary and/or sufficient for mediating VEGF effects on MT. Aim 3 will determine whether reactive oxygen species are necessary and/or sufficient to mediate VEGF-induced augmentation of agonist-induced force generation. We will determine the receptor specificity of VEGF-induced ROS generation and whether inhibition of ROS formation abrogates the effects of VEGF on agonist-induced force. Agonist-induced force generation in tracheal rings derived from gp91phox-deficient or superoxide dismutase transgenic mice will be compared to the effects of antioxidants or enzyme inhibitors. Finally, we will determine whether expression of VEGF modulates Rac activation in vivo and if Rac is necessary and/or sufficient for VEGF-induced ROS and MLC phosphorylation in vitro. Elucidating mechanisms of VEGF-induced alterations in smooth muscle cell force generation fits into the broader program of understanding the contribution of ASM cells to airway remodeling in asthma, and may provide a basis for the development of anti-VEGF therapies aimed at modulating the pathophysiological changes associated with asthma.

慢性重度哮喘的特征是气道炎症和气道高反应性（AHR）。细胞因子和生长因子促进平滑肌细胞增殖、细胞外基质沉积和微血管重塑是气道重塑的显着特征。新的临床证据支持血管内皮生长因子（VEGF）的重要作用，血管内皮生长因子是调节血管的生长因子通透性和血管生成，作为哮喘气道炎症和 AHR 的调节剂。我们呈现令人兴奋的新数据表明 VEGF 增强激动剂诱导的气管环力的产生。血管内皮生长因子还激活 RhoA 和 Rac1 并诱导 ASM 细胞中活性氧 (ROS) 的形成。在根据这些发现，我们假设 VEGF 激活 ASM 细胞中的 Rho 家族 GTPases，通过破坏微管导致增强激动剂诱导的力产生 ROS的形成。为了检验这些假设，我们提出以下具体目标：目标 1 将定义使用鼠模型研究 VEGF 对 Rho 激活和激动剂诱导力产生的体内影响过敏原诱导的气道炎症或 VEGF 转基因过度表达。 VEGF的相对功效受体特异性配体激活 Rho、磷酸化肌球蛋白轻链 (MLC) 并增强激动剂- 感应力将被表征。我们还将确定 VEGF 是否会诱导钙敏感化 ASM 细胞。目标 2 将确定微管 (MT) 破坏是否介导 VEGF 诱导激动剂诱导的力产生增强。我们将确定 MT 是否中断或稳定性改变激动剂诱导的气管环力的产生并表征 VEGF 对 MT 相关蛋白 Tau 的磷酸化。最后，我们将判断Rho是否激活对于介导 VEGF 对 MT 的影响是必要和/或充分的。目标 3 将确定是否有反应氧物种对于介导 VEGF 诱导的激动剂诱导的增强是必要的和/或足够的力的产生。我们将确定 VEGF 诱导的 ROS 生成的受体特异性以及是否 ROS 形成的抑制消除了 VEGF 对激动剂诱导力的影响。激动剂诱导力来自 gp91phox 缺陷或超氧化物歧化酶转基因小鼠的气管环的产生将是与抗氧化剂或酶抑制剂的作用相比。最后我们判断是否表达 VEGF 在体内调节 Rac 激活，以及 Rac 对于 VEGF 诱导的 ROS 是否是必要和/或充分的和 MLC 体外磷酸化。阐明 VEGF 诱导平滑肌改变的机制细胞力的产生适合理解 ASM 细胞对气道的贡献的更广泛的计划哮喘重塑，并可能为开发针对哮喘的抗 VEGF 疗法提供基础调节与哮喘相关的病理生理变化。