Deciphering the mechanisms of c-kit+ cells in heart repair

破译c-kit细胞在心脏修复中的机制

• 批准号: 10166901
• 负责人: WEINIAN SHOU
• 金额: $ 39.38万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-15 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10166901
• 关键词: Acute; Address; Adult; Animals; Attenuated; Cardiac; Cardiac Myocytes; Cell Cycle; Cell Therapy; Cells; Coronary Vessels; Development; Endothelial Cells; Endothelium; Functional disorder; Gene Expression Profile; Genetic; Heart; Heart Injuries; Heart failure; Heterogeneity; Human; In Vitro; Initiator Codon; Label; LacZ Genes; Left Ventricular Remodeling; MYH11 gene; Mammals; Morbidity - disease rate; Mus; Myocardial; Natural regeneration; Nature; Nuclear; PECAM1 gene; Patients; Play; Population; Proliferating; Proto-Oncogene Protein c-kit; Regenerative Medicine; Reporter; Reporter Genes; Reporting; Research; Role; Series; Smooth Muscle; Stem cell transplant; Suicide; Testing; Time; Transplantation; Troponin T; blastomere structure; cardiac repair; coronary vasculature; effective intervention; heart cell; heart function; improved; in vitro activity; in vivo; induced pluripotent stem cell; injury and repair; mortality; mouse model; paracrine; progenitor; programs; self-renewal; stem cells; tool; virtual

PROJECT SUMMARY The c-kit-positive (c-kit+) cells are the first putative population of cardiac stem cells (CSCs) identified in mammals, with self-renewing, clonogenic and multipotent activities in vitro. It also reported that adult cardiac c- kit+ cells are necessary and sufficient for myocardial regeneration. While these findings are encouraging, a recent lineage tracing study in mice indicated that cardiac resident c-kit+ cells have minimal potential to differentiate into cardiomyocytes in vivo. To ascertain the true identity of cardiac c-kit+ cells, we generated a series of new mouse models by targeting reporter genes (H2B-tdTomato, nuclear lacZ and H2B-GFP) and MerCreMer cassette into the start codon of c-kit in mice. With them, we first uncovered that c-kit in fact labels a subpopulation (~43%) of PECAM+ cardiac endothelial cells. After acute cardiac injury, the resident c-kit+ cells still retain their endothelial identity, and have little or no potential to become cardiomyocytes. However, disregard the low myogenic potential of cardiac resident c-kit+ cells during development and after cardiac injury, transplantation of exogenously expanded c-kit+ cells has been consistently shown to improve heart function and attenuate adverse left ventricular remodeling in both ischemic and non-ischemic cardiomyopathy. Thus, there must be unrecognized mechanisms underlying c-kit+ cell therapy. Given our new finding that c-kit actually labels a subpopulation of cardiac endothelial cells, we hypothesized transplanted c-kit+ cells repair the injured heart through their endothelial nature. c-kit+ cells may improve self-renew of the recipient heart by generating new coronary vasculature, or by releasing paracrine factors. Transplanted c-kit+ cells may also be reprogramed and gain multipotency after in vitro expansion. In this research program, we will use state-of-the- art mouse models and human c-kit+ cardiac endothelial cells to test these hypotheses with three Aims: Aim 1 will determine if the endothelial nature of c-kit+ cells contributes to heart repair; Aim 2 will determine if the transplanted c-kit+ endothelial cells promote self-renew of the recipient heart, and if they serve as progenitors to regenerate coronary vessels and/or cardiomyocytes; Aim 3 will determine if the paracrine factors from transplanted c-kit+ cells are essential for heart repair. This project will provide definitive answers to elucidate ultimate mechanisms by which c-kit+ cells promote heart repair.

项目概要 c-kit 阳性 (c-kit+) 细胞是第一个假定的心脏干细胞 (CSC) 群体 哺乳动物，在体外具有自我更新、克隆形成和多能活性。它还报告说，成人心脏 c- kit+细胞对于心肌再生是必要且充分的。虽然这些发现令人鼓舞，但 最近对小鼠进行的谱系追踪研究表明，心脏驻留 c-kit+ 细胞具有最小的潜力 在体内分化成心肌细胞。为了确定心脏 c-kit+ 细胞的真实身份，我们生成了 通过靶向报告基因（H2B-tdTomato、核 lacZ 和 H2B-GFP）开发一系列新的小鼠模型 MerCreMer 盒插入小鼠 c-kit 的起始密码子中。通过他们，我们首先发现 c-kit 实际上标记了 PECAM+ 心脏内皮细胞亚群 (~43%)。急性心脏损伤后，驻留的 c-kit+ 细胞 仍然保留其内皮特性，并且几乎没有或没有成为心肌细胞的潜力。然而， 忽略心脏驻留 c-kit+ 细胞在发育期间和心脏后的低生肌潜力 损伤，移植外源扩增的 c-kit+ 细胞已被一致证明可以改善心脏 功能并减轻缺血性和非缺血性心肌病中不良的左心室重构。 因此，c-kit+细胞疗法背后一定存在未被认识的机制。鉴于我们的新发现，c-kit 实际上标记了心脏内皮细胞的亚群，我们假设移植的 c-kit+ 细胞修复了 通过其内皮性质损伤心脏。 c-kit+细胞可以通过以下方式改善受体心脏的自我更新 产生新的冠状血管系统，或通过释放旁分泌因子。移植的 c-kit+ 细胞也可以 体外扩增后重新编程并获得多能性。在这个研究计划中，我们将使用最先进的 Art 小鼠模型和人类 c-kit+ 心脏内皮细胞通过三个目标来测试这些假设： 目标 1 将确定 c-kit+ 细胞的内皮性质是否有助于心脏修复；目标 2 将确定是否 移植的 c-kit+ 内皮细胞促进受体心脏的自我更新，如果它们作为祖细胞 再生冠状血管和/或心肌细胞；目标 3 将确定旁分泌因子是否来自 移植的 c-kit+ 细胞对于心脏修复至关重要。该项目将提供明确的答案来阐明 c-kit+细胞促进心脏修复的最终机制。

项目成果

Arrhythmia Mechanism and Dynamics in a Humanized Mouse Model of Inherited Cardiomyopathy Caused by Phospholamban R14del Mutation.

• DOI: 10.1161/circulationaha.119.043502
• 发表时间: 2021-08-10
• 期刊: Circulation
• 影响因子: 37.8
• 作者: Raad N;Bittihn P;Cacheux M;Jeong D;Ilkan Z;Ceholski D;Kohlbrenner E;Zhang L;Cai CL;Kranias EG;Hajjar RJ;Stillitano F;Akar FG
• 通讯作者: Akar FG