Preconditioning and re-programming of stem cells for cardiac repair

描述（由申请人提供）：使用具有生肌和血管生成潜能的干细胞或细胞因子诱导的骨髓细胞（BMC）动员至损伤部位的心脏细胞疗法已显示出前景。类似地，缺血预处理和药物预处理具有心脏保护作用。这些治疗方法已被采用，以促进新生心肌再生和逆转心肌梗死（MI）后的有害血流动力学效应。为了达到这些效果，本研究涉及骨髓基质细胞与骨骼肌成肌细胞（SkMs）一起移植，这将主要作为治疗基因的载体。我们的主要假设是，移植前细胞的预处理和重编程将提高它们的存活率，植入和心脏修复的功效。我们研究的主要目的是：目的-1）预处理供体细胞以提高移植后的存活率。我们认为，预处理模拟物处理细胞可能通过刺激细胞存活信号增强其对缺血的耐受性。预处理的（PC）细胞也将表现出旁分泌效应，这将提高宿主心肌细胞在梗死心脏中的存活率。目的-2）心肌内递送过表达SDF-11的非病毒转染的SkM沿着用于BMC动员的瞬时细胞因子疗法以改善心脏功能。我们假设心脏中升高的SDF-11水平将吸引循环中的CXCR 4 + BMCs，在细胞因子治疗后，CXCR 4 + BMCs从BM的流出将明显增加，以参与缺血心脏中血管肌生成的修复过程。目的-3：在移植前激活供体SkMs中的细胞保护调节通路。考虑到Akt和Bcl-2在血管生成素-1（Ang-1）/Tie-2信号通路下游的细胞存活和血管生成中的关键作用，我们假设共过表达Ang-1和Akt或Bcl-2的SkMs的移植将增加细胞存活、增强血管生成和改善心脏功能。目的-4将集中在体外重编程供体细胞定向分化，通过与心肌细胞共培养，以采用移植后的心脏表型。共培养的细胞移植后具有更好的植入和转分化能力。总之，我们的预处理和移植前供体细胞重编程的联合治疗方法有望在缺血损伤心肌的治疗中获得更好的预后。

DESCRIPTION (provided by applicant): Heart cell therapy using stem cells with myogenic and angiogenic potential or cytokine induced mobilization of bone marrow cells (BMCs) to the site of injury has shown promise. Similarly, ischemic and pharmacological preconditioning has cardioprotective effects. These therapeutic modalities have been adopted to promote de novo myocardial regeneration and reversal of deleterious hemodynamic effects after myocardial infarction (MI). In order to achieve these effects the present study involves transplantation of BMCs together with skeletal myoblasts (SkMs) which will serve mainly as carries of therapeutic genes. Our main hypothesis is that preconditioning and re-programming of cells prior to transplantation would enhance their survival, engraftment and efficacy for cardiac repair. The main aims of our study are; Aim-1) Preconditioning of donor cells for their enhanced survival after transplantation. We posit that treatment of cells by preconditioning mimetics may enhance their tolerance to ischemia via stimulation of cell survival signaling. The preconditioned (PC) cells will also exhibit paracrine effects which will give enhanced host myocyte survival in the infarcted heart. Aim-2) Intramyocardial delivery of non-virally transfected SkMs overexpressing SDF-11 along with transient cytokine therapy for BMCs mobilization for improved heart function. We hypothesized that the elevated SDF-11 levels in the heart will attract circulating CXCR4+ BMCs, egress of which from BM will be distinctly increased after cytokine therapy, to participate in the repair process by angiomyogenesis in the ischemic heart. Aim-3: To activate cytoprotective regulatory pathways in donor SkMs before transplantation. Considering a critical role for Akt and Bcl-2 in cell survival and angiogenesis downstream of angiopoietin-1 (Ang-1)/Tie-2 signaling pathway, we hypothesize that transplantation of SkMs co-overexpressing Ang-1 and Akt or Bcl-2 will give increased cell survival, enhanced angiogenesis, and improved cardiac function. Aim-4 will focus on in vitro re-programming of donor cells for directed differentiation via co-culture with cardiomyocytes to adopt cardiac phenotype after transplantation. The co-culture derived cells will show better engraftment and transdifferentiation after transplantation. Put together, our combined therapeutic approach for preconditioning and re-programming of donor cells before transplantation is expected to give better prognosis in the treatment of ischemically injured myocardium.