Enhanced Myocardial Repair with CardioClusters and CardioChimeras

描述(由申请人提供)：心脏的再生能力是通过多种不同的干细胞类型调节的，这是正在进行的密集研究的主题。在过去的十年中，心脏前体细胞(CPC)、间充质干细胞(MSCs)和内皮祖细胞(EPC)的分离和鉴定为干细胞重建受损心脏和推进临床治疗提供了实质性的见解。临床试验已经证明了自体和异体CPC和MSC对人类患者的有效性和安全性，但在改善心功能和减少瘢痕组织方面仍然有限，远远低于恢复正常功能所需的水平。这一建议通过两种新的方法来改善心肌修复，从而克服了这些基于细胞的局限性：1)心脏集群体，一个由CPC、MSCs和EPC组成的三维微环境；2)心脏嵌合体，两个干细胞群体之间的细胞融合产物。这一建议的创新之处在于创建了心脏集合体和心脏嵌合体，能够利用来自单个患者的多个人类干细胞的有益属性，提供临床相关的翻译策略。这项提议的短期目标将决定心脏嵌合体和心脏集群中干细胞的增殖、生长、存活和承诺潜力的增强，这是为改进基于细胞的治疗而优化的。实现这项提议的既定目标将产生心脏群簇和心脏嵌合体的构建和全面特征。具体目标是：1)与心球、单细胞或组合细胞群体相比，心簇表现出更强的增殖、存活和心脏承诺；2)心脏嵌合体相对于非融合细胞群体表现出更好的生长、存活、旁分泌因子的分泌和心脏承诺的特征；3)心簇以及心脏嵌合体在心肌内注射后比心球或单细胞/多细胞悬液更好地恢复心肌结构和功能。这些研究的意义在于创造新的基于细胞的策略，以改善目前的细胞治疗，以减轻缺血性疾病。总的来说，这项提案中的研究将为有选择地适应干细胞行为的干预性方法铺平道路，并合并在人类心脏中发现的干细胞群体的有益属性，以预防心肌病损伤后的心力衰竭。

DESCRIPTION (provided by applicant): Regenerative capacity of the heart is mediated through multiple distinct populations of stem cell types that are the subject of ongoing intense study. In the past decade, isolation and characterization of cardiac progenitor cells (CPCs), mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs) has provided substantial insight to the capabilities of stem cells to rebuild the damaged heart and advance clinical therapy. Clinical trials have proven the efficacy and safety of autologous and allogeneic CPC and MSC delivery to human patients, yet improvements in cardiac function and reduction in scar tissue remain modest and far below that needed for restoration of normal functional output. This proposal overcomes these current cell- based limitations with two novel methods for improving myocardial repair: 1) CardioClusters, a three- dimensional microenvironment consisting of CPCs, MSCs and EPCs, and 2) CardioChimeras, the product of cellular fusion between two stem cell populations. The innovation of this proposal is the creation of CardioClusters and CardioChimeras with the ability to capitalize upon beneficial attributes of multiple human stem cells from a single patient providing a clinically relevant translational strategy. The short-term goal of this proposal will determine the enhanced proliferation, growth, survival and commitment potential of CardioChimeras and stem cells in CardioClusters, which are optimized for improving cell-based therapy. Accomplishing the stated aims of this proposal will yield the construction and comprehensive characterization of CardioClusters and CardioChimeras. Specific Aims are: 1) CardioClusters exhibit enhanced proliferation, survival and cardiac commitment relative to cardiospheres, single or combinatorial cell populations, 2) CardioChimeras display improved characteristics of growth, survival, secretion of paracrine factors and cardiac commitment relative to non-fused cell populations and 3) CardioClusters as well as CardioChimeras restore myocardial structure and function after intramyocardial injection better than cardiospheres or single / multiple cell suspensions. The significance of these studies is to create novel cell-based strategies engineered to improve current cellular therapy to mitigate ischemic disease. Collectively, studies in this proposal will pave the way for interventional approaches to selectively adapt stem cell behavior and merge beneficial attributes of stem cell populations found within the human heart for prevention of heart failure after cardiomyopathic injury.