Thorac Cardiovasc Surg 2012; 60 - V138
DOI: 10.1055/s-0031-1297528

Co-Transplantation of iPS-derived cardiomyocytes and mesenchymal stem cells for the regeneration of infarcted myocardium

K Neef 1, F Drey 1, V Lenerz 2, T Saric 2, OJ Liakopoulos 1, C Stamm 3, T Wittwer 1, T Wahlers 1, YH Choi 1
  • 1Herzzentrum der Universität zu Köln, Klinik für Herz-, und Thoraxchirurgie, Köln, Germany
  • 2Universität zu Köln, Institut für Neurophysiologie, Köln, Germany
  • 3Deutsches Herzzentrum Berlin, Klinik für Herz-, und Thoraxchirurgie, Berlin, Germany

Introduction: Cardiomyocytes generated from induced pluripotent cells (iPS-CM) hold great promise as a sustainable and patient specific source of cells with potential for the regeneration of infarcted myocardium. The goal of this study was to analyze the efficacy of cell transplantation strategies using iPS-CM in combination with mesenchymal stem cells (MSC).

Methods: Directed in vitro differentiation was used to generate iPS-CM from a cardiac specific selectable iPS cell line. Purity and quality of iPS-CM were determined by flow cytometry and immunocytochemistry. Murine MSC were isolated from bone marrow and cell line specificity was confirmed by in vitro differentiation and flow cytometry. A murine animal model was generated by inducing cryo-infarctions and intra-myocardial transplantation of 5×105 iPS-CM, MSC or a combination of both. A clinical 3T MRI scanner was used for the assessment of functional cardiac parameters over the course of four weeks. Immunohistochemical analyses were performed to locate the transplanted cells and determine integration into the host tissue and functional maturation.

Results: iPS-CM were generated by mass culture using an α-MHC promoter specific selection marker, with an efficiency of >300%. The cellular identity of iPS-CM was confirmed by positive immunocytochemical stainings for α-actinin and cardiac troponin T. The presence of contaminating pluripotent cells after differentiation was ruled out by plating on mouse embryonic feeder cells. MSC were validated for expression of CD44 (64.1±4.1%) and Sca1 (98.1±0.9%) and in vitro adipogenic, chodrogenic and osteogenic differentiation potential. After cell transplantations into cryo-infarcted hearts left-ventricular ejection fraction (LVEF) were assessed by MRI and showed significant recovery after four weeks (sham: 43.5±4.7%; iPS: 52.5±4.9%; MSC: 45.0±6.2%; iPS+MSC: 52.3±6.0%; p<0.01). Immunohistochemical analyses for α-actinin and connexin 43 revealed functional integration and structural maturation of iPS-CM.

Conclusion: Intramyocardial co-transplantation of iPS-CM and MSC into infarcted hearts resulted in improved recovery of left ventricular function. In addition we could show efficient integration of iPS-CM into the infarct border zone, demonstrating the potential of combined transplantations of functional cardiac cells with supporting adult stem cells for regenerative therapies. This approach opens a completely new perspective for the regenerative therapy of the heart.