Biological Characterization of Cardiac Stem Cells

描述(申请人提供)：我们已经证明，来自终末期心力衰竭(ESHF)心脏的人心脏干细胞(HCSC)在改善梗死后左心功能方面明显优于年龄匹配的对照HCSC。这项应用的目标是表征ESHF来源的HCSC性能改善的分子机制，并优化它们的收获、分子表征和在临床相关的心肌梗死后心力衰竭模型中的应用。通过干细胞治疗对ESHF患者，特别是终末期心力衰竭儿童的左心功能的改善是巨大的 这很重要，因为心脏移植是唯一可行的选择，而且供应有限。尽管它们的临床I期结果令人鼓舞，但心脏球源细胞(CDCs)由包括c-kit+细胞在内的不同类型的细胞组成，仍然没有很好的特征1。我们的初步数据显示，从左心房分离的hCDC比从右心房分离的hCDC更好地改善缺血左心功能，但是否在所有其他心腔来源的hCDC中存在不同的功能活性仍不清楚。此外，由于我们记录了ESHF来源的CDCs中c-kit+细胞的数量显著增加，CDCs中c-kit+细胞的频率可能对功能的恢复至关重要。最后，ESHF来源的CDC分泌更高水平的血管生成细胞因子，这与梗死心肌血管生成增加和HIF-1a水平增加相关，但细胞因子分泌增加的机制尚不清楚。我们的假设是，ESHF来源的hCDCs改善心肌功能的作用依赖于hCDC来源的解剖部位以及c-kit+和HIF-1a的分子机制。这些研究将通过以下几个方面阐明hCDCs的生物学和功能：1)hCDCs之间的小室特异性差异，可能需要修改以获得更强大的心肌功能活动；2)c-kit+细胞频率对左心功能恢复的影响；以及3)HIF-1a作为ESHF来源的hCDCs心肌功能的主要细胞因子调节因子的作用。ESHF患者，特别是儿童，可能是基于hCDC的治疗的最大受益者。这项应用是第一项旨在确定ESHF来源的hCDCs的关键特性并以一种最终可能影响未来治疗干预的方式揭示其功能活动的新机制的研究。

DESCRIPTION (provided by applicant): We have demonstrated that human cardiac stem cells (hCSC) derived from end-stage heart failure (ESHF) hearts are markedly superior in improving post-infarct LV function in comparison to age-match control hCSC. The goal of this application is to characterize the molecular mechanisms underlying this improved performance of ESHF-derived hCSC and to optimize their harvest, molecular characterization and application in a clinically-relevant model of post-MI cardiac failure. Improvement of LV function in ESHF patients, particularly children with end- stage heart failure, via stem cell therapy is of enormous importance since heart transplantation is the only other viable option and in limited supply. Despite their encouraging clinical Phase I results, cardiosphere derived cells (CDCs), comprised of heterogeneous cell types, including c- kit+ cells, are still not well characterized1. Our preliminary data shows that ESHF-derived hCDCs isolated from the left atrium improve ischemic left ventricular function better than ESHF-derived hCDCs from the right atrium, but whether different functional activity is present in all other heart chamber-derived hCDCs is still unknown. Furthermore, since we document significantly higher numbers of c-kit+ cells within ESHF-derived CDCs, the frequency of the c-kit+ cells within CDCs may be critical to recovery of function. Finally, ESHF-derived CDCs secrete higher levels of angiogenic cytokines that correlates with increased angiogenesis in the infarcted myocardium and higher levels of HIF-1a, but the mechanism for the increased cytokine secretion is unclear. Our hypothesis is that the effect of ESHF-derived hCDCs in improving myocardial function is dependent on the anatomic site of hCDC origin and molecular mechanisms by c-kit+ and HIF- 1a. These studies will clarify the biology and function of hCDCs by determining: 1) chamber specific differences amongst hCDCs with the potential need to modify for a more powerful myocardial functional activity, 2) the effect of the frequency of c-kit+ cells on LV recovery, and lastly, 3) the role of HIF-1a as a master cytokine regulator of the myocardial function of ESHF- derived hCDCs. ESHF patients, particularly children, are potentially the most to benefit from hCDC based therapies. This application is the first study designed to determine critical characteristics of ESHF-derived hCDCs and to uncover new mechanisms of their functional activity in a manner that may eventually influence future therapeutic interventions.