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.

慢性严重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，细胞外基质的沉积和微血管重塑，是气道重塑的突出特征。新的临床证据支持血管内皮生长因子（VEGF）的重要作用，这是调节血管的生长因子渗透性和血管生成，作为哮喘中气道炎症和AHR的调节剂。我们在场令人兴奋的新数据表明，VEGF增强了激动剂诱导的气管环产生。 VEGF 还激活RhoA和Rac1，并诱导ASM细胞中活性氧（ROS）的形成。在关于这些发现的光，我们假设VEGF激活了ASM细胞中的Rho家族GTPase，通过微管的破坏和 ROS的形成。为了检验这些假设，我们提出以下具体目的：AIM 1将定义 VEGF对RHO激活和激动剂诱导的力产生的体内影响，使用鼠模型过敏原引起的气道炎症或VEGF的转基因过表达。 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 - 诱导力将被表征。我们还将确定VEGF是否在 ASM细胞。 AIM 2将确定微管（MT）是否介导VEGF诱导的激动剂引起的力产生的增强。我们将确定MT中断还是稳定化改变了激动剂引起的气管环产生，并表征了VEGF对 MT相关蛋白Tau的磷酸化。最后，我们将确定Rho激活是否是必要和/或足以介导VEGF对MT的影响。 AIM 3将确定反应性是否氧气是必要的和/或足以介导VEGF诱导的激动剂诱导的增强力产生。我们将确定VEGF诱导的ROS产生的受体特异性，以及是否是否 ROS形成的抑制作用消除了VEGF对激动剂诱导的力的影响。激动剂引起的力源自GP91Phox缺乏或超氧化物歧化酶转基因小鼠的气管环的产生与抗氧化剂或酶抑制剂的作用相比。最后，我们将确定是否表达 VEGF的体内调节RAC激活，如果RAC是必需的，并且/或足以用于VEGF诱导的ROS 体外MLC磷酸化。阐明VEGF诱导的平滑肌改变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程序哮喘进行改造，可能为开发针对抗VEGF疗法的发展提供基础调节与哮喘相关的病理生理变化。