Evaluating the efficacy of a miR-10 therapy after myocardial infarction

冠状动脉粥样硬化性血栓闭塞引起的心肌梗死(MI)是全球范围内导致缺血后心力衰竭和心脏性猝死的主要危险因素。虽然在治疗急性心肌梗死方面取得了重大进展，包括基于导管的介入和新的辅助治疗，但由于缺血后心力衰竭，长期死亡率和住院率增加。目前，改善心肌梗塞后预后的有效治疗方法是抑制血小板和神经内分泌的激活。新的分子治疗方案的目标是通过诱导和促进新的毛细血管和侧支动脉形成来增加冠脉血流量。虽然引入经典的单一促血管生成生长因子的几种基因治疗方法在临床试验中未能证明有效，但基于miRNA的基因治疗的最新进展在大型动物试验中被证明是有效的。在我们和其他人之前的工作中，miR-10被确定为斑马鱼、小鼠和人类血管内皮细胞中一种有效的正向血管生成调节剂。值得注意的是，miR-10s的促血管生成功能特别是通过旁分泌机制介导的。除了促进血管生成的功能外，其他几项研究表明，强制在细胞中表达miR-10可以有效地阻止细胞凋亡，而且miR-10也是以旁分泌的方式，能够有益地调节组织炎症，促进愈合。目前的项目建议遵循这样的假设，即miR-10代表了一个有吸引力的、多事实的作用的新靶点，部分通过积极调节血管生成、改善心肌细胞存活和控制炎症过程来有益地改变MI后的结果。这些实验旨在评估心肌梗死后心脏miR-10过度表达的治疗潜力。在第一个具体目标中，i)我们将评估在对照动物体内过表达miR-10的影响，以评估miR-10治疗的潜在不良反应，我们将收集包括药效学、药动学和毒理学在内的参数的初步数据。在第二个特定目标中，我们将确定AAV9-miR-10介导的过表达对心肌梗死后体内的有益影响。因此，我们将评估正常情况下和MI后心功能和心肌血管形成、坏死性瘢痕组织分布以及细胞死亡和炎性细胞聚集的变化。这项研究的概念设计遵循非临床环境下的概念验证方法，系统地评估miR-10疗法治疗缺血性心脏病的潜力。

Myocardial loss due to myocardial infarction (MI) triggered by atherothrombotic occlusion of coronary vessels is the major risk factor for post-ischemic heart failure and sudden cardiac death world wide. While major advances have been made in treating acute myocardial infarction including catheter based interventions and novel adjunctive medical treatments, long-term mortality and hospitalization rates increased due to post-ischemic heart failure. Todays potent therapeutic approaches to improve the outcome after MI aim at inhibiting platelet and neuroendocrine activation. Novel molecular therapy options target at increasing coronary blood flow by inducing and enhancing new capillary and collateral arterial vessel formation. While several gene therapy approaches introducing classical single proangiogenic growth factors failed to demonstrate effectiveness in clinical trials, recent progress in miRNA based gene therapies hold great promise and proved potency in large animal trials. In previous work by us and others, miR-10 was established as a potent positive modulator of angiogenesis in zebrafish, mouse and human endothelial cells. Noticeably, miR-10s pro-angiogenic function is particularly mediated through paracrine mechanisms. Besides it pro-angiogenic function, it was shown by several others that forced expression of miR-10 in a cell actively blocked apoptosis and that miR-10, also in a paracrine fashion, is able to beneficially modulate tissue inflammation to promote healing. The present project proposal follows the hypothesis, that miR-10 represents an attractive, multifactual acting, new target to beneficially change the outcome post-MI in part by positively modulate angiogenesis, improving cardiomyocyte cell survival and controlling inflammatory processes. The proposed experiments aim at evaluating the therapeutic potential of cardiac miR-10 overexpression after MI. In the first specific aim I) we will evaluate the effects of miR-10 overexpression in vivo in control animals to assess potential adverse effects of a miR-10 therapy and we will collect initial data on parameters, including pharmacodynamics, pharmacokinetics and toxicology. In a second specific aim II) we will determine the beneficial impact of AAV9-miR-10 mediated overexpression in vivo post-MI. Therefor, we will assess changes in heart function and myocardial vascularization, in necrotic scar tissue distribution as well as cell death and accumulation of inflammatory cells under normal conditions and after MI. The conceptual design of this study follows a proof of concept approach in a non-clinical setting to systematically evaluate the potential of miR-10 therapy to treat ischemic heart disease.