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，包括细胞外小泡(EV)，前景看好。 其他干预措施失败的严重冠心病糖尿病患者的治疗选择。而动物- 基于细胞疗法的研究一直很有希望，临床试验未能显示出类似的疗效 CAD.5-7这种差异可能是由于代谢综合征(MS)环境中的信号改变所致。《长河》 申请者获得这项研究奖学金的学期目标是发展坚实的基础和核心技能。 从事学术心胸研究，在此之后，他可以开始作为心脏外科科学家的职业生涯 完成外科临床培训。这个项目的总体目标是阐明分子 EV诱导缺血心肌冠状动脉侧支循环形成的临床机制 相关的猪MS模型，明确血糖控制在增强EV诱导的作用中的作用 血管生成。中心假设是，血糖控制将减少活性氧簇(ROS)，改变 AMP：ATP比率，并增加血管内皮生长因子诱导的PI3K-Akt信号，允许增强EV介导 血管生成。核心假设将通过追求两个具体目标来检验：1)确定 冠状动脉新生血管关键信号通路的血糖调控及侧支反应 猪缺血心肌对人骨髓间充质干细胞来源的EVS的影响 2)确定低氧修饰的HBMSC来源的EV的影响，该EVS包含增加的水平 血管内皮生长因子/肝细胞生长因子、葡萄糖转运蛋白SLC2A14和Akt对大鼠冠状动脉血管生成和心肌灌注的影响 有无血糖控制的多发性硬化症猪模型的慢性缺血心肌。对于这两个目标，一个 利用左回旋支收缩建立饮食诱导多发性硬化和慢性心肌缺血的猪模型 被利用。应用二甲双胍治疗多发性硬化症和慢性心肌缺血并进行血糖控制的猪 心内注射HBMSC-EV与低氧修饰HBMSC-EV与安慰剂比较。分析将是 对参与血管生成信号转导的蛋白质、血管密度、心肌 灌流和心脏功能。本申请中提出的研究具有创新性，因为它调查了 HBMSC-EV在临床相关大动物模型中治疗慢性心肌缺血的应用 代谢综合征，更准确地反映了人类复杂的病理生理和共病 病人。这项拟议的研究具有重要意义，因为它有望确定临床相关的治疗方法 可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开发针对慢性阻塞性肺疾病患者的创新疗法。 心肌缺血，与美国国立卫生研究院增进健康、延长生命、减少疾病和 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.