Year 5

We have developed a protocol devoid of genetic manipulations to derived progenitor cells with myogenic differentiation potential from human embryonic stem cells (hESCs). These hESC-derived cells underwent myogenic differentiation in vitro both in the presence and absence of serum in culture medium. When transplanted in vivo into an injured muscle, these pre-myogenically committed cells were viable in tibialis anterior muscles 14 days post-implantation. A manuscript describing these results have been published (Hwang Y, Suk S,Lin S, Tierney M, Du B, Seo T, Mitchell A, Sacco A, Varghese S. Directed in vitro myogenesis of human embryonic stem cells and their in vivo engraftment. PLoS One, 8, e72023 (2013). We have further modified the culture conditions to improve myogenic differentiation. When transplanted into injured muscles of immune-deficient NOD/SCID mice, a significant portion of fraction of the transplanted cells were found to be engrafted. Additionally, we observed localization of a large number of transplanted cells in the centers of muscle fibers indicating the contribution of the transplanted cells towards the muscle regeneration. Additionally, we also observed contribution of the transplanted donor cells towards the satellite compartment. The high proliferative capacity of hESCs along with their ability to differentiate into functional skeletal myogenic progenitor cells and engraft in vivo without teratoma formation highlights their potential therapeutic applications to ameliorate skeletal muscle defects and injuries.