Role of VSMC-Derived Exosomes in the Cardiovascular Complications of Diabetes

 描述（由申请人提供）：糖尿病的心血管并发症部分源自内皮细胞（EC）、巨噬细胞和血管平滑肌细胞（VSMC）功能的促动脉粥样硬化变化。 因此，糖尿病导致的VSMC中miRNA表达的变化可能通过外泌体介导的miRNA转移促进糖尿病的心血管并发症，所述外泌体介导的miRNA转移诱导内皮活化和动脉炎症。本提案的目的是确定外泌体介导的miR-221/222转移在糖尿病介导的心血管疾病增加中的影响。我们的初步数据表明，糖尿病VSMC衍生的外泌体（DVE）促进内皮细胞活化，内皮功能障碍，以及巨噬细胞向炎症表型的转变。此外，我们发现DVE促进体内动脉粥样硬化斑块的形成。该提案假设：糖尿病伴随着VSMC分泌的外泌体中miR-221/222增加，其通过促进内皮细胞活化和功能障碍以及巨噬细胞向促炎表型极化来加速心血管疾病进展（M1）。该假设将通过三个具体目标进行检验：1）证明DVE通过增加miR-221/222促进动脉粥样硬化斑块形成。2)证明DVE通过eNOS解偶联以及巨噬细胞表型向促炎M1状态的转变促进内皮细胞活化和活性氧增加; 3）将VSMC中IGFR的损失与DVE的miR-221/222含量增加和响应于DVE治疗的动脉粥样硬化斑块形成增加联系起来。目的1将证明DVE促进动脉粥样硬化斑块形成。目的2将描述DVE如何促进EC功能障碍、EC活化和巨噬细胞向炎症表型的极化。每个目标还将检查miR-221/222在这些效应中的作用。目的3将扩展我们目前的研究结果，以了解DVE中miR-221/222增加的机制。该项目的预期结果是证明糖尿病伴随着DVE的产生，DVE促进EC和巨噬细胞中的心血管疾病。这些数据将产生重大的积极影响，因为它们将确定糖尿病人群心血管疾病增加背后的新机制。这项提案中的研究是创新的，因为它将推动我们理解的范式转变 的作用，血管平滑肌细胞在动脉粥样硬化病变的形成，通过引入一种新的机制，使血管平滑肌细胞改变EC和巨噬细胞的功能。

 DESCRIPTION (provided by applicant): The cardiovascular complications of diabetes derive, in part, from pro-atherosclerotic changes in the function of endothelial cells (ECs), macrophages, and vascular smooth muscle cells (VSMCs). Thus, changes in miRNA expression in VSMCs as a result of diabetes may promote the cardiovascular complications of diabetes via exosome mediated transfer of miRNA that induce endothelial activation and arterial inflammation. The objective of this proposal is determining the impact of exosome mediated transfer of miR-221/222 in the diabetes mediated increase in cardiovascular disease. Our preliminary data demonstrate that diabetic VSMC-derived exosomes (DVEs) promote endothelial cell activation, endothelial dysfunction, and a shift of macrophages toward an inflammatory phenotype. Furthermore, we found that DVEs promote atherosclerotic plaque formation in vivo. This proposal hypothesizes: Diabetes is accompanied by increased miR-221/222 in the exosomes secreted by VSMCs that accelerates cardiovascular disease progression by promoting endothelial cell activation and dysfunction as well as a polarization of macrophages toward a pro-inflammatory phenotype (M1). The hypothesis will be tested through three specific aims: 1) Demonstrate that DVEs promote atherosclerotic plaque formation through an increase in miR-221/222.; 2) Demonstrate that DVEs promote endothelial cell activation and increased reactive oxygen species through eNOS uncoupling as well as a shift in macrophage phenotype toward the pro-inflammatory M1 state; 3) Link loss of the IGFR in VSMCs to the increased miR-221/222 content of DVEs and increased atherosclerotic plaque formation in response to DVE treatment. Aim 1 will demonstrate that DVEs promote atherosclerotic plaque formation. Aims 2 will characterize how DVEs promote EC dysfunction, EC activation, and polarization of macrophages toward an inflammatory phenotype. Each aim will also examine the role of miR-221/222 in these effects. Aim 3 will extend the findings of our current research to understand the mechanism underlying the increase in miR-221/222 in DVEs. Together the expected outcome of this project is a demonstration that diabetes is accompanied by the generation of DVEs that promote cardiovascular disease in ECs and macrophages. These data will have a significant positive impact as they will identify novel mechanisms behind the increased cardiovascular disease in the diabetic population. The research in this proposal is innovative because it will drive a paradigm shift in our understanding of the role of VSMCs in atherosclerotic lesion formation by introducing a novel mechanism whereby VSMCs alter EC and macrophage function.