Abstract 19065: Circulating Cells Contribute to Post-infarction Myocardial Repair by Adopting Mature Cardiomyocyte and Endothelial Cell Fates

Objective: Whether bone marrow derived circulating cells engraft in ischemic myocardium and adopt non-hematopoietic fates remains controversial. Discordance may result from limitations of parabiosis models for fate tracking. Using a bone marrow chimera model, we hypothesized that circulating cells do, in fact, contribute to mature vessel formation and myocardial regeneration. Methods: Recipient C57BL/6 (n=16) or C57BL/6-GFP mice (n=13) were lethally irradiated (10 Gy) and transplanted with 5x106 whole bone marrow cells from C57BL/6-DsRed donors. Four weeks post transplant, animals underwent acute myocardial infarction (MI) by ligation of the left anterior descending artery. Hearts were explanted 3 weeks post MI and were examined histologically. Individual cells were sorted after Langendorff isolation with FACS (Fig 1A). Results: Bone marrow transplant reproducibly yielded >90% chimerism in peripheral blood and in the hematopoietic stem cell population. The majority of DsRed+ circulating cells adopted matu...