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 K+ (KATP) 通道在心脏中大量表达。 现在确定了这些通道在介导缺血性损伤的心脏保护及其作用中的关键作用 在心脏中参与缺血预适应的保护机制有几种不同。 KATP 通道的亚型，但对于缺血和再灌注期间的作用知之甚少。 人们感兴趣的是冠状动脉平滑肌 (SM) 和冠状动脉内皮细胞中存在的 KATP 通道亚型 人们越来越关注这些冠状通道作为血流调节和调节的目标。 心脏保护作用，但人们对 SM 和 EC KATP 通道的了解相对较少。 心室 KATP 通道，并且它们也彼此不同，这是我们理解的主要障碍。 它们在心肌缺血等复杂事件中各自的作用是目前缺乏的 专门用于研究这两种通道亚型的资源我们已经生成了新型遗传小鼠模型。 可以区分 KATP 通道的这些亚型，并用其中之一显示 EC KATP 通道 强烈参与缺血/再灌注期间的心肌保护。拟议研究的目标是。 系统地研究 EC 和 SM KATP 通道亚型在冠状动脉调节中的作用 血流量、缺血期间的保护以及对缺血预处理的保护反应。 认为 EC 和 SM KATP 通道亚型都有助于冠状动脉血液的调节 流量和心脏保护，但通过明显不同的机制。 条件敲除小鼠中，我们将专门针对 EC 或 SM KATP 通道亚型提出研究。 有三个目标 在目标 1 中，我们将研究这两种冠状动脉 KATP 通道亚型在血液中的作用。 我们将使用隔离的、加压的微血管和隔离的、灌注的心脏。 我们还将研究 EC 和 SM KATP 通道的作用。 目标 2 将研究 EC 和 SM KATP 通道在心肌“无复流”现象中的作用。 使用体内小鼠 I/R 模型进行心肌保护并研究调节梗塞的途径 目标 3 将研究 EC 和 SM KATP 通道亚型在缺血期间的贡献。 我们还将使用体内小鼠 I/R 模型和细胞测定进行预处理。 KATP 通道亚型作为潜在的保护机制并研究分子信号通路 这项多位研究人员的提案结合了三位知名研究人员的专业知识； Lefer 在体内心脏缺血/再灌注模型方面拥有丰富的专业知识，Coetzee 博士在 使用电生理学、生化和分子方法以及 Tinker 博士的方法研究 KATP 通道 研究血管 KATP 通道分子信号传导途径的专业知识。 为冠状动脉 KATP 通道亚型的独特功能提供重要的分子见解 病理生理条件。