Conclusions
Thus, 3F-iPS bioengineered without c-MYC achieve highest stringency criteria for bona fide cardiogenesis enabling reprogrammed fibroblasts to yield de novo heart tissue compatible with native counterpart throughout embryological development and into adulthood.
Objective
Here, we determined from embryo to adult the cardiogenic proficiency of iPS programmed without c-MYC, a cardiogenicity-associated transcription factor.
Results
Transgenic expression of 3 human stemness factors SOX2, OCT4, and KLF4 here reset murine fibroblasts to the pluripotent ground state. Transduction without c-MYC reversed cellular ultrastructure into a primitive archetype and induced stem cell markers generating 3-germ layers, all qualifiers of acquired pluripotency. Three-factor induced iPS (3F-iPS) clones reproducibly demonstrated cardiac differentiation properties characterized by vigorous beating activity of embryoid bodies and robust expression of cardiac Mef2c, alpha-actinin, connexin43, MLC2a, and troponin I. In vitro isolated iPS-derived cardiomyocytes demonstrated functional excitation-contraction coupling. Chimerism with 3F-iPS derived by morula-stage diploid aggregation was sustained during prenatal heart organogenesis and contributed in vivo to normal cardiac structure and overall performance in adult tumor-free offspring. Conclusions: Thus, 3F-iPS bioengineered without c-MYC achieve highest stringency criteria for bona fide cardiogenesis enabling reprogrammed fibroblasts to yield de novo heart tissue compatible with native counterpart throughout embryological development and into adulthood.