Injury-induced fetal reprogramming imparts multipotency and reparative properties to pericardial adipose stem cells.

BACKGROUND: Injury may induce a sequential activation of intrinsic reparative activity that supports the maintenance of tissue homeostasis. METHOD: In the present experiments, we investigated whether myocardial infarction (MI) was able to reinstate the expression of Wilms' tumor factor 1 (WT1) as a key hallmark of fetal reprograming in the pericardial adipose-derived stem cells (pADSC). We characterized the immunophenotypical markers, cardiac potential, and reparative activity of WT1-expressing pADSC (WT1(pos)) isolated MI Wistar rats with an intact pericardial sac in which cardiac transudate was accumulated, sampled, and analyzed. RESULTS: The WT1(pos) cells formed colony-like aggregates in culture that subsequently generated phase-bright cells that homogenously constituted WT1 expression (> 98%). The WT1(pos) cells shared identical surface markers with canonical pADSC, but enhanced transcripts for cardiogenesis (isl-1, gata-4, Sox2 and Tbx18) as well as cardiac commitment (endothelial: 28%; cardiomyogenic: 12.3%) in defined conditions. Remarkably, cardiac transplantation of WT1(pos) cells promoted regional angiogenesis and myogenesis which led to significant functional amelioration of the infarcted hearts. Furthermore, we demonstrated that WT1(pos) cells uniquely secreted hepatocyte growth factor (HGF) as a key antiapoptotic factor that promotes cardiac repair. CONCLUSION: Injury-associated fetal reprogramming in pADSC facilitates cardiac differentiation and promotes the reparative activity by enhancing HGF production. As such, injury-"conditioned" pADSC may represent a useful autologous cell donor from infarcted patients for cell-based therapy.