Co-transplantation of mesenchymal bone-marrow cells increases persistence of murine iPS-derived cardiomyocytes at 24h after intramyocardial injection into healthy syngeneic hearts

摘要

Objectives: Cardiac cell replacement therapy is a promising the rapy to improve cardiac function in heart failure, a major cause of morbidity and mortality in the world. In contrast to clinically intensively tested bone-marrow cells, embryonic or induced pluripotent stem cell can be differentiated into functional cardiomyocytes (ES-CM or iPS-CM) which after transplantation can integrate into host myocardium and thereby replace lost myocardium. Since engraftment and persistence of transplanted ES-CM and iPS-CM was found to be very limited, we tried to increase it in this study by co-transplantation of non-cardiomyocytes with iPS-CM. Methods: ES-CM and iPS-CM were derived and highly purifed from transgenic male murine embryonic or induced pluripotent stem cells using an antibiotic resistance under the control of a cardiac specific promoter. 300,000 ES-CM or iPS-CM with or without admixture of 300,000 000 syngeneic male murine mesenchymal stem cells (MSC) or syngeneic male murine embryonic fibroblasts (MEF) were intramyocardially injected into healthy hearts of syngeneic female mice. Hearts were explanted after 24h, DNA was isolated and the number of transplanted cells was determined using quantitative real-time PCR with transgene specific primers. For every surgery day, 1 additional aliquot was mixed with an explanted heart ex-vivo and served as control and known dilutions of transgene positive in transgene negative DNA were included to derive a calibration curve