Project 2 - Role of Inflammation in CMC-Induced Myocardal Repair

细胞疗法改善心脏功能的机制尚不清楚。尽管注入的细胞 最小限度地分化为心肌细胞或血管，只有一小部分在 受者，无论注射的细胞类型如何，都观察到共同的有益影响：泵的改善 功能，减少纤维化，促进血管生成。这些结果与细胞 治疗利用了内源性修复机制，然而，这些机制尚未被确定。免疫者 该系统与多种无菌疾病有关，包括调节心肌损伤的过程 并进行修复。尽管未解决的炎症过程由浸润性和组织驻留免疫控制 细胞加重心力衰竭，梗塞心肌中巨噬细胞耗尽导致左室破裂和 死亡。因此，免疫细胞似乎在心脏中扮演着截然相反的角色。巨噬细胞已经 被证明是新生哺乳动物心肌损伤后自发再生所必需的，以及 最近的发现表明，它们是细胞治疗介导的心肌修复的直接贡献者。不过， 免疫细胞如何调节心肌修复以及是什么决定了它们的有害与有益行为 仍然不为人知。此外，细胞疗法对修复性免疫细胞的影响尚未被研究。 在内心深处。我们的初步数据显示，将心脏间充质细胞(CMCs)注射到梗死区 心脏促进修复性巨噬细胞的积累。因此，这一提议的中心假设是 巨噬细胞促进单核细胞的募集和修复性巨噬细胞的激活，这是必不可少的。 内源性修复介质。通过对免疫细胞群体进行详细的流式细胞术分析 在CMC给药后，我们不仅将解决免疫细胞募集的时间进程，还将 确定细胞治疗后心脏炎症最终是如何消退的。为了澄清 巨噬细胞调节单核细胞来源的巨噬细胞炎症过程的机制，我们将 确定这些细胞如何调节NFB-p65亚单位的表达，重点是水平转移 通过CMC来源的EVS向巨噬细胞传递miRNAs。最后，利用巨噬细胞遗传命运图谱和 转基因巨噬细胞，我们将阐明单核细胞来源的巨噬细胞在CMC诱导中的作用 心肌修复。该项目将首次对细胞疗法如何调节免疫细胞进行系统分析。 --一种研究相对较少的机制。研究结果将提供新的见解，不仅是对 调控细胞治疗的机制介导的心肌修复，还包括内源性修复的方式 巨噬细胞的活动被招募。我们还将确定电动汽车是否概括了 免疫细胞上的巨噬细胞。因此，这些研究对于我们理解 免疫系统总体上调节心肌内环境的稳定。

The mechanism by which cell therapy improves cardiac function remains unclear. Although injected cells minimally differentiate into cardiomyocytes or vessels, and only a small fraction survive long term in the recipient, common beneficial effects are observed regardless of injected cell type: improvement in pump function, reduction of fibrosis, and enhanced angiogenesis. These results are consistent with the idea that cell therapy recruits endogenous repair mechanisms which, however, have not been identified. The immune system has been implicated in a variety of sterile diseases, including processes regulating myocardial damage and repair. Although unresolved inflammatory processes controlled by infiltrating and tissue-resident immune cells worsen heart failure, depletion of macrophages in the infarcted myocardium leads to LV rupture and death. Thus, immune cells appear to play diametrically opposite roles in the heart. Macrophages have been shown to be required for spontaneous regeneration of neonatal mammalian myocardium after injury, and recent findings implicate them as direct contributors to cell therapy-mediated myocardial repair. Nevertheless, how immune cells regulate myocardial repair and what determines their harmful versus salutary actions remains unknown. Furthermore, the impact of cell therapy on reparative immune cells has not yet been studied in the heart. Our preliminary data show that injection of cardiac mesenchymal cells (CMCs) into the infarcted heart promotes accumulation of reparative macrophages. Thus, the central hypothesis of this proposal is that CMCs facilitate recruitment of monocytes and activation of reparative macrophages, which are essential endogenous mediators of repair. By generating detailed flow cytometric analyses of immune cell populations following CMC administration, we will not only resolve the time course of immune cell recruitment, but also determine how inflammation is eventually extinguished in the heart after cell therapy. To elucidate the mechanism whereby CMCs regulate inflammatory processes in monocyte-derived macrophages, we will determine how these cells regulate NFB-p65 subunit expression, with emphasis on horizontal transfer of miRNAs to macrophages through CMC-derived EVs. Finally, using macrophage genetic fate mapping and genetically modified CMCs, we will elucidate the role of monocyte-derived macrophages in CMC-induced myocardial repair. This project will be the first systematic analysis of how cell therapy modulates immune cells – a mechanism that has been relatively understudied. The results will provide novel insights not only into the mechanisms regulating cell therapy-mediated myocardial repair, but also into how endogenous reparative activities of macrophages are recruited. We will also determine whether EVs recapitulate the salutary effects of CMCs on immune cells. Thus, these studies have far-reaching implications for our understanding of how the immune system regulates myocardial homeostasis in general.