Ion Channel Regulation Coronary Smooth Muscle Phenotype

离子通道调节冠状动脉平滑肌表型

• 批准号: 7140016
• 负责人: DOUGLAS K BOWLES
• 金额: $ 27.3万
• 依托单位: UNIVERSITY OF MISSOURI-COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-12-01 至 2010-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7140016
• 关键词: atherosclerosis; calcium channel; calcium flux; cardiovascular disorder prevention; coronary disorder; dietary lipid; disease /disorder model; exercise; gene expression; hyperlipidemia; microspectrophotometry; miniature swine; mitogens; nitric oxide; nitric oxide synthase; nutrition related tag; phenotype; potassium channel; small interfering RNA; transcription factor; vascular endothelium; vascular smooth muscle; voltage gated channel; western blottings

It is becoming increasingly evident that calcium influx in vascular smooth muscle is a strong modulator of smooth muscle (SM) gene regulation and phenotype via activation of calcium-dependent transcription factors. We provide evidence that L-type calcium influx is necessary for the constitutive expression of smooth muscle-specific differentiation markers (SMX: e.g. SMMHC, SMaA) and that exercise can increase L-type calcium channel function in coronary smooth muscle (CSM). The general aim of this proposal is to determine the mechanism(s) by which exercise training limits CSM phenotype switching during atherosclerosis. The overall hypothesis is that calcium influx via L-type, voltage-gated calcium channels (L-VGCC) stabilizes CSM in a differentiated, contractile phenotype. Conversely, dedifferentiation and proliferation are stimulated by upregulation of intermediate-conductance K channels (IK) and store-operated calcium channels (SOC). Exercise training prevents CSM phenotypic switching by maintaining L-VGCC activity and subsequent SM-specific, calcium-dependent gene expression. The Specific Aims are:1) Determine the effect of atherosclerosis on CSM ion channel functional expression, 2) Determine the effect of atherosclerosis on intracellular calicum regulation by membrane potential, 3) Determine the effect of L-type VGCC- versus IK/SOC-mediated calcium influx on calcium-dependent transcription factors and SMX and 4) Determine whether exercise training can prevent the loss of L-type VGCC-mediated SMX. Early and advanced models of atherosclerosis will be produced in swine by dietary high-fat, high-cholesterol (HFC) or balloon injury. Both in vitro and in vivo measures of CSM phenotype will be determined using molecular, cellular and in vivo coronary angiography techniques. The proposed research will provide the first mechanistic link between coronary ion channel activity and CSM phenotype switching. Furthermore, it will provide the first mechanistic examination of the role of CSM in the cardioprotective effect of exercise.

越来越明显的是，血管平滑肌的钙涌入是强大的调节剂 平滑肌（SM）基因调节和表型通过钙依赖性转录的激活 因素。我们提供了证据表明L型钙涌入是必要的 平滑肌特异性分化标记（SMX：例如SMMHC，SMAA），该运动可以增加 冠状动脉平滑肌（CSM）中的L型钙通道功能。该提议的一般目的是 确定运动训练限制CSM表型切换的机制 动脉粥样硬化。总体假设是通过L型，电压门控钙通道（L-VGCC）流入钙的流入 在分化的收缩表型中稳定CSM。相反，去分化和 通过上调中等导电k通道（IK）和储存 钙通道（SOC）。锻炼训练可以通过维护L-VGCC来防止CSM表型转换 活性和随后的SM特异性钙依赖性基因表达。具体目的是：1） 确定动脉粥样硬化对CSM离子通道功能表达的影响，2）确定 动脉粥样硬化对膜电位调节细胞内钙的调节，3）确定L型的作用 VGCC-与IK/SOC介导的钙依赖性转录因子和SMX的钙涌入和4） 确定运动训练是否可以防止L型VGCC介导的SMX的损失。早 动脉粥样硬化的高级模型将通过猪，高脂，高胆固醇（HFC）或 气球受伤。 CSM表型的体外和体内测量都将使用分子， 细胞和体内冠状动脉造影技术。拟议的研究将提供第一个 冠状离子通道活性与CSM表型切换之间的机械联系。此外，它将 提供CSM在运动的心脏保护作用中的作用的首次机械检查。