Cardioprotective Repair through Cardiopoiesis

描述(申请人提供)：心肌梗死是发病率的主要原因，由于心肌自我更新能力有限而导致收缩性能丧失。胚胎干细胞分化为心肌细胞的能力为再生修复提供了机会。事实上，这些典型干细胞用于治疗的基础在于它们固有的多能性，然而，独特的多谱系分化能力带来了肿瘤生长的风险，其好处超过了阻碍修复应用的好处。这项建议的目的是磨练干细胞的可塑性，以消除恶性倾向的非引导分化，以实现安全修复。初步研究表明，在内胚层导向的心脏营养信号的瞬时窗口期间，发育中的拟胚体内的胚胎干细胞群体具有明确的生心承诺的能力，由此产生的中胚层产生了祖细胞“造心”干细胞表型。目的1将(I)利用类胚体干细胞分化分离这一促心源性群体，(Ii)确定其分子特性，以及(Iii)确定其向终末性心肌转化的倾向。目的#2将(I)破译内胚层来源的心肌营养信号，(Ii)以类胚体的方式大规模招募促心源性心脏生成细胞群，(Iii)在体内验证这种新型干细胞的安全性。目的#3将(I)评估获得的心脏干细胞在治疗心肌梗死中的治疗潜力，(Ii)确定修复的潜在机制，以及(Iii)设计干细胞以增强对应激的耐受性，从而实现增强的心脏保护结果。基于心脏干细胞的特征和心脏营养信号的特征，这一建议将剖析心脏生成确保形成多能性的基本过程。在分子和细胞水平上对心脏发生的剖析将进一步整合到治疗范例中，并转化到器官和生物水平上，用于安全的基于细胞的心肌梗死再生治疗。

DESCRIPTION (provided by applicant): Myocardial infarction is a leading cause of morbidity with loss of contractile performance precipitated by the limited capacity of heart muscle for self-renewal. The aptitude of embryonic stem cells for differentiation into cardiomyocytes provides an opportunity for regenerative repair. Indeed, the basis for therapeutic use of these quintessential stem cells lies in their inherent pluripotency, yet the distinct ability for multi-lineage differentiation carries the liability of neoplastic growth that outweighs benefit impeding reparative applications. The objective of this proposal is to hone stem cell plasticity in order to nullify malignancy-prone unguided differentiation for safe repair. Preliminary studies demonstrate the aptitude for definitive cardiogenic commitment of an embryonic stem cell population within the developing embryoid body, during a transient window of endoderm-directed cardiotrophic signaling, with the resulting specification of the mesoderm yielding a progenitor "cardiopoietic" stem cell phenotype. Aim #1 will (i) isolate this pro-cardiogenic population utilizing embryoid body-based stem cell differentiation, (ii) define its molecular identity, and (iii) determine its propensity for terminal cardiomyogenic transformation. Aim #2 will (i) decipher the endoderm-derived cardiotrophic signaling, (ii) recruit in an embryoid body-free manner the pro-cardiogenic cardiopoietic population at large scale, and (iii) validate in vivo the safety profile of this novel stem cell type. Aim #3 will (i) assess the curative potential of procured cardiopoietic stem cells in treating myocardial infarction, (ii) determine the underlying mechanism for repair, and (iii) engineer stem cells for augmented tolerance to stress achieving enhanced cardioprotective outcome. Based on the characterization of cardiopoietic stem cells and the profiling of cardiotrophic cues, this proposal will dissect the fundamental process of cardiopoiesis securing formative confinement of pluripotency. Dissection of cardiogenesis at the molecular and cellular level will be further integrated into a therapeutic paradigm, and translated to the organ and organism level for safe cell-based regenerative therapy of myocardial infarction.