Preconditioning and re-programming of stem cells for cardiac repair

描述(申请人提供)：心脏细胞疗法，使用具有肌肉和血管生成潜力的干细胞或细胞因子诱导的骨髓细胞(BMC)动员到损伤部位已显示出希望。同样，缺血和药物预适应也具有心脏保护作用。这些治疗方法已被用于促进心肌梗死(MI)后的新生心肌再生和逆转有害的血流动力学效应。为了达到这些效果，本研究涉及将骨髓基质细胞与骨骼肌母细胞(Skms)一起移植，后者将主要作为治疗性基因的载体。我们的主要假设是，细胞在移植前的预适应和重新编程将提高它们的存活率、植入率和心脏修复的有效性。我们研究的主要目的是：1)对供体细胞进行预适应，以提高其移植后的存活率。我们推测，模拟预适应处理细胞可能通过刺激细胞生存信号来增强其对缺血的耐受性。预适应(PC)细胞也将表现出旁分泌效应，这将提高心肌梗死后宿主心肌细胞的存活率。目的-2)非病毒转染法高表达SDF-11的骨髓基质细胞心肌内注射，结合一过性细胞因子治疗动员骨髓细胞以改善心功能。我们推测，心脏中SDF-11水平的升高将吸引循环中的CXCR4+BMC参与缺血心脏的修复过程，细胞因子治疗后，循环中的CXCR4+BMC从骨髓中排出的数量将明显增加。目的-3：在供体干细胞移植前激活细胞保护调节通路。考虑到Akt和Bcl2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，我们推测共过表达Ang-1和Akt或Bcl-2的干细胞移植将增加细胞存活，增强血管生成，改善心功能。AIM-4将致力于供体细胞的体外重新编程，通过与心肌细胞共培养定向分化，以适应移植后的心脏表型。共培养的来源细胞将在移植后表现出更好的植入和转分化。综上所述，我们在移植前对供者细胞进行预适应和重新编程的联合治疗方法有望在治疗缺血损伤的心肌方面提供更好的预后。

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.