Roles of Endothelial and Smooth Muscle KATP Channels in Myocardial Ischemic Injury

内皮和平滑肌 KATP 通道在心肌缺血性损伤中的作用

• 批准号: 9914670
• 负责人: William A Coetzee
• 金额: $ 75.63万
• 依托单位: LSU HEALTH SCIENCES CENTER
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-01 至 2023-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9914670
• 关键词: Biochemical; Biochemistry; Biology; Blood Preservation; Blood Vessels; Blood flow; Cardiac; Cell Death; Cellular Assay; Collaborations; Complex; Coronary; Coronary Vessels; Data; Development; Electrophysiology (science); Endothelial Cells; Endothelium; Environment; Event; Functional disorder; Genetic; Goals; Heart; Hypoxia; Infarction; Ion Channel; Ischemia; Ischemic Preconditioning; Joints; Knock-out; Knockout Mice; Mediating; Mitochondria; Modeling; Molecular; Mus; Myocardial; Myocardial Ischemia; Myocardium; Pathway interactions; Pharmacology; Physiological; Play; Positioning Attribute; Proteins; Protocols documentation; Publications; Regulation; Reperfusion Injury; Reperfusion Therapy; Research; Research Personnel; Research Support; Resources; Role; Signal Pathway; Signal Transduction; Smooth Muscle; Smooth Muscle Myocytes; Stress; Surface; Two-Dimensional Echocardiography; Ventricular; cardioprotection; conditional knockout; coronary vasculature; density; experience; experimental study; heart function; in vivo; insight; interest; ischemic injury; mouse model; novel; preconditioning; pressure; response; tool; trafficking; vascular bed

SUMMARY Sarcolemmal ATP-sensitive K+ (KATP) channels are abundantly expressed in the heart. Several groups have now identified a key role for these channels in mediating cardioprotection against ischemic injury and their participation in the protective mechanism of ischemic preconditioning. In the heart there several different subtypes of KATP channels and little is known about the roles during ischemia and reperfusion. Of particular interest are the KATP channel subtypes present in the coronary smooth muscle (SM) and coronary endothelial cells (EC). There is increasing focus on these coronary channels as a target for blood flow regulation and cardioprotection, yet they are relatively poorly understood. The SM and EC KATP channels are distinct from ventricular KATP channels and they are also distinct from each other. A major barrier to our understanding of their respective roles during a complex event such as myocardial ischemia is the lack of currently available resources specifically to study these two channel subtypes. We have generated novel genetic mouse models that can distinguish these subtypes of KATP channels and show with one of these that EC KATP channels strongly participate in myocardial protection during ischemia/reperfusion. The goal of the proposed studies is systematically to examine the role(s) of the EC and SM KATP channel subtypes in the regulation of coronary blood flow, protection during ischemia and the protective response to ischemic preconditioning. We hypothesize that both EC and SM KATP channel subtypes contribute to the regulation of coronary blood flow and cardioprotection, but through distinctly different mechanisms. Using novel and validated conditional knockout mice, we will specifically target EC or SM KATP channel subtypes. The proposed studies have three Aims. In Aim 1, we will investigate the roles of these two coronary KATP channel subtypes in blood flow during ischemia. We will use isolated, pressurized microvessels and isolated, perfused hearts under normal, hypoxic and ischemic conditions. We will additionally investigate the role of EC and SM KATP channels in the myocardial “no-reflow” phenomenon. Aim 2 will investigate the roles of EC and SM KATP channels in myocardial protection using an in vivo murine I/R model and investigate pathways that regulate infarct development. Aim 3 will investigate the contribution of EC and SM KATP channel subtypes during ischemic preconditioning using an in vivo murine I/R model and cellular assays. We will also examine trafficking of these KATP channel subtypes as a potential protective mechanism and investigate molecular signaling pathways involved. This multi-investigator proposal combines the expertise of three highly established investigators; Dr. Lefer’s extensive expertise with in vivo cardiac ischemia/reperfusion models, and Dr. Coetzee’s track record of studying KATP channels with electrophysiological, biochemical and molecular approaches and Dr. Tinker’s expertise in studying molecular signaling pathways in vascular KATP channels. The proposed studies will provide important molecular insights into the unique functions of coronary KATP channel subtypes under pathophysiological conditions.

概括 肌膜ATP敏感的K+（KATP）通道在心脏中是绝对表达的。有几个小组 现在确定了这些渠道在介导针对缺血性损伤及其的心脏保护方面的关键作用 参与缺血性预处理的受保护机制。在心中有几种不同 KATP通道的亚型和在缺血和再灌注过程中的作用知之甚少。特别 兴趣是冠状动脉平滑肌（SM）和冠状动脉内皮中存在的KATP通道亚型 细胞（EC）。这些冠状动脉通道作为血流调节的目标和 心脏保护作用，但它们相对较少了解。 SM和EC KATP通道与 心室KATP通道，它们彼此之间也不同。我们理解的主要障碍 他们在复杂活动（例如心肌缺血）中各自的角色缺乏当前可用的 专门研究这两个通道亚型的资源。我们已经产生了新型的遗传小鼠模型 可以区分KATP通道的这些亚型，并用其中之一显示EC KATP通道 在缺血/再灌注期间，强烈参与心肌保护。拟议研究的目的是 系统地检查EC和SM KATP通道亚型在冠状动脉调节中的作用 血流，缺血期间的保护以及对缺血性预处理的受保护反应。 假设EC和SM KATP通道亚型都有助于调节冠状动脉血液 流动和心脏保护，但通过明显不同的机制。使用小说并经过验证 有条件的敲除小鼠，我们将专门针对EC或SM KATP通道亚型。提出的研究 有三个目标。在AIM 1中，我们将研究这两个冠状动脉KATP通道亚型在血液中的作用 缺血期间流动。我们将使用孤立的，加压的微血管和孤立的，灌注的心 正常，低氧和缺血状况。我们还将研究EC和SM KATP通道的作用 在心肌“无流动”现象中。 AIM 2将研究EC和SM KATP渠道的作用 使用体内鼠I/R模型的心肌保护并调查调节保险的途径 发展。 AIM 3将研究缺血性期间EC和SM KATP通道亚型的贡献 使用体内鼠I/R模型和细胞测定法进行预处理。我们还将检查这些贩运 KATP通道亚型作为潜在的受保护机制，并研究了分子信号通路 涉及。该多次投资者提案结合了三位备受熟悉的研究人员的专业知识；博士 Lefer具有体内心脏缺血/再灌注模型的广泛专业知识，以及Coetzee博士的往绩记录 使用电生理，生化和分子方法研究KATP通道和Tinker博士 研究血管KATP通道中分子信号通路的专业知识。拟议的研究将 为冠状动脉KATP通道亚型的独特功能提供重要的分子见解 病理生理状况。