Role of Drebrin in Vascular Smooth Muscle Remodeling

Drebrin 在血管平滑肌重塑中的作用

• 批准号: 8438339
• 负责人: JONATHAN A STIBER
• 金额: $ 37.37万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-20 至 2018-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8438339
• 关键词: Actin-Binding Protein; Angioplasty; Angiotensin II; Arterial Injury; Arterial Intimas; Atherosclerosis; Binding; Blood Pressure; Blood Vessels; Calcium; Calcium Signaling; Cations; Complex; Congestive Heart Failure; Continuous Infusion; Cytoskeletal Modeling; Cytoskeleton; Endothelium; Exhibits; Family; Future; Histologic; Homer 1; Hyperplasia; Hypertension; In Vitro; Knowledge; Lead; Link; Measurement; Measures; Medial; Mediating; Medical; Mission; Modeling; Molecular; Morbidity - disease rate; Mus; Myocardial Infarction; Neonatal; Pathogenesis; Phenotype; Platelet-Derived Growth Factor; Process; Proliferating; Proteins; Public Health; Regulation; Research; Role; Scaffolding Protein; Signal Pathway; Signal Transduction; Small Interfering RNA; Smooth Muscle Myocytes; Stroke; Testing; Therapeutic; Vascular Smooth Muscle; Vascular remodeling; Yeasts; arterial remodeling; burden of illness; cell motility; cell transformation; congenic; disability; drebrins; fetal bovine serum; in vivo; innovation; insight; link protein; loss of function; migration; mortality; novel; novel therapeutic intervention; protein complex; public health relevance; receptor; response; restenosis; scaffold; treatment strategy; yeast two hybrid system

DESCRIPTION (provided by applicant): Integral to the pathogenesis of atherosclerosis is the transformation of vascular smooth muscle cells (SMCs) from a "contractile" to a "proliferative/migratory" phenotype. This transformation also underlies the arterial "remodeling" associated with hypertension and restenosis following angioplasty and stenting. On a molecular level, this SMC transformation involves cytoskeletal signaling and calcium signaling pathways. Transient receptor potential (TRP) channels are a family of nonselective cation channels which have been implicated in the modulation of calcium influx during vascular remodeling. Critical missing details include what proteins link TRP channels to cytoskeletal signaling pathways and how these proteins influence SMC migration. We have previously shown that TRP channels require the scaffolding protein Homer 1 for proper function. Homer 1 associates with Drebrin, an actin-binding protein highly expressed in SMCs--as we showed using yeast-two hybrid studies, in vitro binding studies, and mutational analyses. In Preliminary Studies, reducing Drebrin expression with siRNA produced spontaneous calcium influx similar to that we observed in the absence of Homer 1. Our Preliminary Studies also show that, compared with WT SMCs, SMCs from Drebrin haploinsufficient (Dbn-/+) mice migrate faster and have increased basal TRP channel activity. We also found that Drebrin expression is upregulated in response to arterial injury, suggesting a role for Drebrin in the regulation of vascular remodeling. Because of the importance of TRP channels in SMC migration and the importance of Drebrin/Homer scaffolds in regulating TRP channels, we plan to test the hypothesis that the Drebrin inhibits SMC transformation to the proliferative/migratory phenotype through regulation of TRP channel function. To test this hypothesis, we will pursue the following Specific Aims. 1) To determine the role of Drebrin in TRP channel regulation in SMCs. We hypothesize that Drebrin loss of function will result in TRP channel dysregulation characterized by increased TRP channel activity and Ca2+ influx. 2) To determine the effect of Drebrin on SMC migration and proliferation. We hypothesize that TRP channel dysregulation observed in Drebrin loss-of-function models will result in increased migration and proliferation compared with controls, both in vitro and in vivo. 3) To determine the effect of Drebrin on hypertensive arterial remodeling. We expect that, compared with WT, Dbn-/+ mice will exhibit similar hypertensive responses but increased medial expansion in response to angiotensin II-induced hypertension. The research proposed in this application is innovative because it focuses on TRP channel regulation by a protein complex, comprising Homer 1 and Drebrin, whose role in the vasculature is currently unknown. The impact of our studies will be to provide critical insights into the function of TRP-regulatory scaffolding proteins which link TRP channel activation with cytoskeletal signaling complexes during SMC migration.

描述（由申请人提供）：动脉粥样硬化的发病机理不可或缺的是血管平滑肌细胞（SMC）从“收缩”转变为“增殖/迁移”表型。这种转变还构成了与血管成形术和支架后高血压和再狭窄相关的动脉“重塑”。在分子水平上，这种SMC转化涉及细胞骨架信号传导和钙信号通路。瞬态受体电位（TRP）通道是一个非选择性阳离子通道的家族，与血管重塑过程中钙涌入的调节有关。关键缺少细节包括哪些蛋白质将TRP通道与细胞骨架信号通路联系起来以及这些蛋白质如何影响SMC迁移。我们先前已经表明，TRP通道需要脚手架蛋白质荷马1才能正确功能。荷马1与Drebrin（一种在SMC中高度表达的肌动蛋白结合蛋白）辅助 - 正如我们使用酵母 - 两种杂种研究，体外结合研究和突变分析所表明的。在初步研究中，用siRNA降低Drebrin的表达产生的自发性钙涌入与我们没有荷马1相似的自发钙涌入。我们的初步研究还表明，与WT SMC相比，与WT SMC相比，来自DREBRIN HAPLOINSUNDING FORIAND FORIANS FAIMASS SMC（DBN - /+）小鼠迁移了越来越及其基础TRP TRP TRP TRAP Clannel TRAL PISTICT。我们还发现，DREBRIN的表达因动脉损伤而上调，这表明Drebrin在调节血管重塑中的作用。由于TRP通道在SMC迁移中的重要性以及Drebrin/Homer支架在调节TRP通道中的重要性，因此我们计划测试DREBRIN通过调节TRP通道函数抑制SMC转化对增殖/迁移表型的假设。为了检验这一假设，我们将追求以下特定目标。 1）确定DREBRIN在SMC中TRP通道调节中的作用。我们假设DREBRIN功能丧失将导致TRP通道失调，其特征是TRP通道活性增加和Ca2+流入。 2）确定Drebrin对SMC迁移和增殖的影响。我们假设在DREBRIN功能丧失模型中观察到的TRP通道失调将导致与体外和体内对照组相比，将导致迁移和增殖增加。 3）确定德雷布林对高血压动脉重塑的影响。我们预计，与WT相比，DBN-/+小鼠将表现出相似的高血压反应，但对血管紧张素II诱导的高血压的反应增加了内侧膨胀。该应用程序中提出的研究具有创新性，因为它专注于蛋白质复合物的TRP通道调节，其中包括Homer 1和Drebrin，其在脉管系统中的作用目前尚不清楚。我们的研究的影响是提供对TRP调节脚手架蛋白功能的关键见解，该蛋白将TRP通道激活与SMC迁移过程中的细胞骨架信号传导复合物联系起来。