Cellular Cardiomyoplasty for Chronic Heart Failure

描述(由申请人提供)：在对慢性缺血性心脏病的基于细胞的疗法的理解和翻译方面取得了重大进展，这种疾病影响了大约500万美国人。我们利用该奖项的第一个资助期开发了以渐进性心室重塑为特征的复杂的猪缺血性心肌病模型。使用这个模型，我们已经测试了几种基于细胞的治疗策略，收集了主要的机械学见解，并开发了足够的临床前数据来启动临床试验。重要的是，我们发现间充质干细胞(MSCs)在受损猪心内的植入和分化伴随着1)与宿主细胞缝隙连接的形成，2)刺激内源性心脏干细胞(CSC)的增殖和分化，3)在既往慢性缺血功能障碍的心肌区持续反向重构和收缩恢复。在初步研究结果中，我们还表明，联合使用MSCs和CSCs可显著提高缩小梗塞面积的疗效。在这份续期申请中，我们建议确定 使用我们已建立的猪模型，这种基于细胞的治疗缺血性心肌病的新策略的分子基础。因此，我们提出了一系列三个目标，旨在测试关于MSC和基于CSC的心脏再生的新机制假说。我们建议1)建立自体CSCs和MSCs联合应用改善心肌梗死瘢痕减少的机制，2)评估连接蛋白43(Cx43)介导的细胞间连接对心脏再生的影响，3)评估细胞间的相互作用和药物和/或基因修饰的CSCs在缺血性心肌病心肌修复中的疗效。这些研究将继续我们的工作轨迹，旨在尽可能获得最可靠的临床前数据，以扩大我们对慢性缺血性心脏病基于细胞的治疗机制的知识基础。拟议的研究是及时的，有理由的，并可能通过解决大量患者中未得到满足的需求来解决进行性心力衰竭、终身残疾、心脏性猝死和反复住院的风险，从而对健康产生重大影响。所采用的方法得到了我们团队的良好验证，包括体外和体内实验模型以及我们团队目前使用的高效细胞递送系统和最先进的成像策略。我们的机制研究项目具有很高的翻译价值和非常重要的意义，因为细胞疗法提供了 修复心肌梗死后左心功能不全患者再生新的心肌并减少心力衰竭的进展。总之，这些目标将促进我们对基于细胞治疗慢性缺血性心脏病的潜在机制的理解，特别强调细胞组合的影响。 可以具有相加或协同特性的分子机制的类型和调节，从而提高细胞治疗缺血性心肌病的有效性和持久性。

DESCRIPTION (provided by applicant): Major progress has been made in the understanding and translational advancement of cell-based therapeutics for chronic ischemic heart disease, a condition affecting approximately 5 million Americans. We have used the first funding period of this award to develop sophisticated porcine models of ischemic cardiomyopathy characterized by progressive ventricular remodeling. Using this model we have tested several strategies for cell-based therapeutics, gleaned major mechanistic insights, and developed sufficient preclinical data to be able to initiate clinical trials. Importantly, we showed that engraftment and differentiation of mesenchymal stem cells (MSCs) in the injured porcine heart was accompanied by 1) gap junction formation with host cells, 2) stimulation of endogenous cardiac stem cell (CSC) proliferation and differentiation and 3) sustained reverse remodeling and contractile restoration in myocardial areas of prior chronic ischemic dysfunction. In preliminary findings, we also showed that combining MSCs with CSCs leads to substantially greater efficacy at infarct size reduction. In this renewal application, we propose to identify the molecular underpinnings of this novel cell- based therapeutic strategy for ischemic cardiomyopathy using our established porcine model. Accordingly, we propose a series of three aims designed to test novel mechanistic hypotheses regarding MSC and CSC-based cardiac regeneration. We propose to 1) establish the mechanisms underlying the improved infarct scar reduction resulting from a combination of autologous CSCs and MSCs, 2) assess the impact of cell-cell communication by connexin 43 (Cx43)-mediated gap junctions on cardiac regeneration, and 3) assess the cell- cell interaction and efficacy of pharmacologically and/or genetically modified CSCs for myocardial repair in ischemic cardiomyopathy. These studies will continue our trajectory of work designed to obtain the most robust preclinical data possible to enlarge our knowledge base of the mechanisms underlying cell-based therapy for chronic ischemic heart disease. The proposed studies are timely, warranted, and could have a major health impact by addressing an unmet need in a large population of patients at risk for progressive heart failure, lifelong disability, sudden cardiac death, and recurrent hospitalizations. The approaches employed are well validated by our group and include in vitro and in vivo experimental models and efficient cell delivery systems and state of the art imaging strategies currently in use by our group. Our mechanistic research program has high translational value and is highly significant, as cellular therapy offers the potential to regenerate new myocardium and decrease progression of heart failure in patients with left ventricular dysfunction due to healed myocardial infarction. Together, these aims will advance our understanding of the mechanisms underlying cell- based therapy for chronic ischemic heart disease, with specific emphasis placed upon the impact of a combination of cell types and modulation of molecular mechanisms that can have additive or synergistic properties, thereby enhancing the efficacy and durability of cell therapy for ischemic cardiomyopathy.