Impact of Glycemic Control on Extracellular Vesicle-Mediated Angiogenesis in a Porcine Model of Chronic Myocardial Ischemia and Metabolic Syndrome

终末期弥漫性冠状动脉疾病（CAD）的治疗选择， 糖尿病，1，2仍然有限。再生疗法，包括细胞外囊泡（EV），是有前途的 其他干预失败的重度CAD糖尿病患者的治疗选择。当动物- 细胞疗法的基础研究已经很有希望，但临床试验未能证明类似的疗效， CAD.5-7这种差异可能是由于代谢综合征（MS）背景下信号传导的改变。长 申请人在追求这项研究奖学金的长期目标是发展一个强大的基础和核心技能 以学术心胸研究为背景，他可以在之后开始作为心脏外科医生科学家的职业生涯。 完成外科临床培训。本项目的总体目标是阐明 临床研究中EV诱导缺血心肌中冠状动脉侧支形成的机制 MS的相关猪模型，特别是确定血糖控制在增强EV诱导的MS中的作用。 血管生成核心假设是血糖控制将减少活性氧（ROS），改变血糖水平。 AMP：ATP比率，并增加VEGF诱导的PI 3 K-Akt信号传导，允许增强EV介导的 血管生成中心假设将通过追求两个具体目标来检验：1）确定 血糖控制对参与冠状动脉血管生成和支化反应的关键信号通路的影响 人骨髓间充质干细胞（HBMSC）衍生的EV在猪模型中的缺血心肌 2）鉴定含有增加的MS水平的低氧修饰的HBMSC衍生的EV的作用， VEGF/HGF、葡萄糖转运蛋白SLC 2A 14和Akt对冠状动脉血管生成和心肌灌注的影响 慢性缺血性心肌在猪模型的MS，血糖控制和不控制。为了实现这两个目标， 采用左旋Ameroid收缩法建立饮食诱导MS和慢性心肌缺血的猪模型， 被利用患有MS和慢性心肌缺血的猪，在使用和不使用二甲双胍控制血糖的情况下， 注射（心内）HBMSC-EV vs低氧修饰HBMSC-EV vs安慰剂。分析将 对参与血管生成信号传导的蛋白质的分子表达、血管密度、心肌 灌注和心脏功能。本申请中提出的研究是创新的，因为它调查了 在临床相关的大型动物模型中使用HBMSC-EV治疗慢性缺血心肌， 代谢综合征，更准确地反映了人类复杂的病理生理学和共病 患者这项拟议的研究意义重大，因为它有望确定临床相关的治疗方法。 增强慢性缺血心肌对HBMSC-EV的血管生成反应的策略。 最终，这些知识可能有助于为慢性胰腺炎患者开发创新疗法。 心肌缺血，符合NIH的使命，以提高健康，延长寿命，减少疾病， 残疾。

Therapeutic options for end-stage, diffuse coronary artery disease (CAD), an important complication of diabetes,1,2 remain limited. Regenerative therapies, including extracellular vesicles (EV), are promising therapeutic options for diabetic patients with severe CAD who have failed other interventions. While animal- based studies of cell therapy have been promising, clinical trials have failed to demonstrate similar efficacy in CAD.5–7 This discrepancy may be due to altered signaling in the setting of metabolic syndrome (MS). The long term goal of the applicant in pursuing this research fellowship is to develop a strong foundation and core skill set in academic cardiothoracic research, with which he can launch a career as a cardiac surgeon scientist after completing surgical clinical training. The overall objective of this project is to elucidate the molecular mechanisms involved in EV-induced coronary collateral development in ischemic myocardium in a clinically relevant porcine model of MS, specifically identifying the role of glycemic control in augmenting EV-induced angiogenesis. The central hypothesis is that glycemic control will reduce reactive oxygen species (ROS), alter AMP:ATP ratio, and increase VEGF-induced PI3K-Akt signaling, allowing for augmented EV-mediated angiogenesis. The central hypothesis will be tested by pursuing two specific aims: 1) Identify the effects of glycemic control on key signaling pathways involved in coronary angiogenesis and collateralization response of ischemic myocardium to human bone marrow mesenchymal stem cell (HBMSC) derived EVs in a porcine model of MS; 2) Identify the effects of hypoxia-modified HBMSC-derived EVs containing increased levels of VEGF/HGF, glucose transporter SLC2A14, and Akt, on coronary angiogenesis and myocardial perfusion in chronically ischemic myocardium in a porcine model of MS, with and without glycemic control. For both aims, a porcine model of diet-induced MS and chronic myocardial ischemia using left circumflex ameroid constriction will be used. Swine with MS and chronic myocardial ischemia with and without glycemic control using metformin will be injected (intracardiac) with HBMSC-EV vs hypoxia-modified HBMSC-EV vs placebo. Analysis will be performed on molecular expression of proteins involved in angiogenesis signaling, vessel density, myocardial perfusion, and cardiac function. The research proposed in this application is innovative because it investigates the use of HBMSC-EV to treat chronically ischemic myocardium in a clinically relevant large animal model of metabolic syndrome, which more accurately reflects the complex pathophysiology and co-morbidities in human patients. The proposed research is significant because it is expected to identify clinically relevant therapeutic strategies that can enhance the angiogenic response of chronically ischemic myocardium to HBMSC-EV. Ultimately, such knowledge may contribute to the development of innovative therapies for patients with chronic myocardial ischemia, aligning with the NIH mission to enhance health, lengthen life, and reduce illness and disability.