Scientists at the University of Minnesota have succeeded in almost completely regenerating skeletal muscle in a mouse model of muscular dystrophy, using genetically unmodified mouse pluripotent stem cells (PSCs) collected from an unexpected source. Sunny Sun-Kin Chan, Ph.D., Michael Kyba, Ph.D., and colleagues, isolated skeletal muscle stem cells from PSC-derived teratomas—a benign tumor that can produce cells of any type—which they transplanted into damaged tibialis anterior (TA) muscle tissue in the experimental mice.

They found that even small numbers of cells readily engrafted, regenerated up to 80% of the skeletal muscle volume, and significantly improved muscle strength and resistance to fatigue. In fact, the transplanted teratoma-derived muscle stem cells were found to exhibit a far greater regenerative potential than muscle stem cells generated in the lab from genetically modified pluripotent stem cells. The transplants also generated a source of new muscle stem cells to maintain the reconstructed muscle …