Subendothelial Exosomes in Coronary Microvascular Dysfunction

内皮下外泌体在冠状动脉微血管功能障碍中的作用

• 批准号: 10586075
• 负责人: PinLan Li
• 金额: $ 54.11万
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-03-15 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10586075
• 关键词: Address; Angina Pectoris; Angiography; Animals; Applications Grants; Arteries; Atherosclerosis; Blood; Blood flow; Cell Communication; Cell membrane; Cells; Ceramides; Chest Pain; Code; Coronary; Coronary Arteriosclerosis; Coronary artery; Development; Diagnosis; Endothelial Cells; Endothelin; Endothelin-1; Endothelium; Enzymes; Extracellular Matrix; Farber' s lipogranulomatosis; Functional disorder; Future; Gene Deletion; Genes; Heart; Human; Impairment; Inflammasome; Inflammatory; Knockout Mice; Lead; Lipids; Literature; Lysosomes; Mediating; Metabolism; MicroRNAs; Microvascular Dysfunction; Multivesicular Body; Mus; Muscle Contraction; Myocardial Infarction; Myocardial Ischemia; NADPH Oxidase; Pathogenesis; Pathogenicity; Pathologic; Pathology; Patients; Play; Prevention; Process; Prostaglandins; Proteins; Proteoglycan; Regulation; Relaxation; Reporting; Risk Factors; Role; Signal Transduction; Smooth Muscle; Smooth Muscle Myocytes; Sphingolipids; Sphingomyelins; Sphingosine; Stimulus; Stream; Testing; Thinness; Vascular Diseases; Vesicle; Work; acute coronary syndrome; arterial remodeling; arteriole; atherogenesis; constriction; exosome; galactosylgalactosylglucosylceramidase; hypercholesterolemia; insight; knockout gene; microvesicles; novel; novel therapeutics; particle; prevent; receptor; response; trafficking; vascular injury; western diet

Project Summary Coronary microvascular dysfunction or disease (CMD) may lead to angina pectoris or acute coronary syndrome (ACS) without obstructive coronary artery disease (CAD), which is considered as one of major mechanisms of ischemia heart disease (IHD). However, the pathogenesis of CMD remains unclear. Based on literature and our previous studies, we wondered whether exosomes or other microvesicles-mediated signaling from endothelial cells (ECs) serve as a crucial mechanism mediating CMD because much thinner endothelium- smooth muscle (EC-SM) space in small coronary arteries (CAs) or arterioles than large arteries may limit the development of typical atherogenic pathology, but the exosome-carrying molecules may result in functional abnormality in these small coronary arteries. Our preliminary studies indeed demonstrated that exosomes were increasingly secreted into subendothelial space in small coronary arteries in mice fed the Western diet (WD) and that deletion of lysosomal acid ceramidase (AC) in coronary ECs from Asah1fl/fl/ECcre mice, a strain of EC- specific AC gene knockout mice (Asah1 is mouse gene code of AC) resulted in accumulation or trapping of exosomes in the EC-SM space, leading to CMD-mediated myocardial ischemia without atherosclerosis and obstructive CAD. The present grant proposal will test a central hypothesis that endothelium-derived exosomes regulated by lysosomal AC-mediated sphingolipid metabolism plays a crucial role in the control of small CA function and that subendothelial exosome accumulation is critically implicated in the pathogenesis of CMD. To test this hypothesis, three Specific Aims are proposed. Specific Aim 1 will determine whether exosome secretion from coronary arterial ECs is fine controlled by lysosomal AC activity and whether the deficiency of this AC regulation causes subendothelial accumulation of exosomes in small CAs of Asah1fl/fl/ECcre mice, leading to CMD and myocardial ischemia without atherosclerosis and obstructive CAD. Specific Aim 2 attempts to test whether lysosomal AC-mediated sphingolipid signaling regulates lysosome trafficking to and fusion with multivesicular bodies (MVBs) to limit exosome secretion from ECs and whether pathologically released exosomes from ECs with gene deletion from Asah1fl/fl/ECcre mice induce dysfunction of coronary arterial SMCs. In Specific Aim 3, we will address whether the AC regulation of lysosome trafficking and exosome secretion from coronary ECs are attributed to its action on lysosomal TRPML1 channel activity and associated Ca2+ release and whether the deficiency of this regulatory mechanism leads to subendothelial exosome accumulation and CMD. To our knowledge, these proposed studies will represent the first effort to investigate the pathogenic role of subendothelial exosomes in CMD and consequent myocardial ischemia and the findings will provide new insights into the pathogenesis of CMD and IHD without atherosclerosis or obstructive CAD.

项目摘要 冠状动脉微血管功能障碍或疾病（CMD）可能导致心绞痛或急性冠状动脉 没有阻塞性冠状动脉疾病（CAD）的综合征（ACS），这被认为是主要的 缺血性心脏病（IHD）的机制。但是，CMD的发病机理尚不清楚。基于 文献和我们以前的研究，我们想知道外泌体或其他微泡介导的信号传导是 从内皮细胞（EC）作为介导CMD的至关重要机制，因为内皮较薄 小动脉中的小动脉或小动脉中的平滑肌（EC-SM）空间可能限制 开发典型的动脉粥样硬化病理学，但外泌体携带分子可能会导致功能性 这些小型冠状动脉异常。我们的初步研究确实表明外泌体是 在小鼠喂养西方饮食（WD）的小鼠小鼠中，越来越分泌成冠状动脉的下皮空间 并从asah1fl/fl/eccre小鼠的冠状动脉EC中缺失溶酶体酸神经酶（AC），这是一种EC-的菌株 特定的AC基因基因敲除小鼠（ASAH1是AC的小鼠基因代码）导致积累或捕获 EC-SM空间中的外泌体，导致CMD介导的心肌缺血没有动脉粥样硬化和 阻塞性CAD。目前的赠款提案将检验一个中心假设，即内皮衍生的外泌体 受溶酶体AC介导的鞘脂代谢调节在小CA的控制中起着至关重要的作用 功能和内皮下外泌体积累与CMD的发病机理至关重要。到 检验该假设，提出了三个具体目标。具体目标1将决定外泌体是否 冠状动脉EC的分泌受溶酶体AC活性的良好控制，以及是否缺乏 该AC调节导致外泌体的下皮积累，在ASAH1FL/FL/ECCRE小鼠的小CAS中 导致CMD和心肌缺血没有动脉粥样硬化和阻塞性CAD。具体目标2 试图测试溶酶体AC介导的鞘脂信号传导是否调节溶酶体运输到和 与多囊体（MVB）融合以限制EC的外泌体分泌以及是否在病理上 从ASAH1FL/FL/ECCRE小鼠中释放出具有基因缺失的EC的外泌体诱导冠状动脉功能障碍 动脉SMC。在特定目标3中，我们将解决溶酶体贩运和 冠状动脉EC的外泌体分泌归因于其对溶酶体TRPML1通道活动的作用和 相关的CA2+释放以及该调节机制的缺乏是否导致下皮下皮 外泌体积累和CMD。据我们所知，这些拟议的研究将代表 研究下皮外泌体在CMD中的致病作用以及随之而来的心肌缺血和 这些发现将为CMD和IHD发病机理提供新的见解，而无需动脉粥样硬化或 阻塞性CAD。