DALLAS-Embryonic stem cells (ESCs) have been touted as a potential therapeutic for a number of debilitating diseases, including muscular dystrophy. Treating muscular dystrophies with ESCs has focused on using the stem cells to produce a key structural protein of muscle cells called dystrophin, which is under expressed due to genetic mutations in sufferers of the disease. Until now, this approach has been hampered by the inability to get ESCs to form muscle cells at significant levels for treatment.

 

That may be changing, according to a new paper published last week on the online edition of Nature Medicine. In the paper, Rita Perlingeiro and colleagues at the University of Texas Southwest Medical Center demonstrate a new way to manipulate ESCs that overcome this hurdle and show functional recovery in mouse models of Duchenne muscular dystrophy (DMD) after injection of human ESCs.

 

In the study, Perlingeiro, et al, focused on the transcription factor Pax3 which orchestrates muscle development in the embryo. Through genetic manipulations of ESCs, the researchers were able to overcome the hurdle of human ESCs grown in a culture dish not being exposed to the embryonic environmental milieu that includes muscle differentiation, by directly expressing Pax3. This manipulation allows a muscle progenitor cell population to arise in quantities sufficient for use therapeutically in mice. The researchers delivered the cells through the circulation, as opposed to intramuscular injection, thus targeting more muscle locations with the results showing significantly improved muscle function.

 

The use of these progenitor cells also did not result in tumor formation, another stumbling block to using ESCs therapeutically.

 

The researchers point out that genetic manipulation of the human ESCs disallows this technique to be used in the clinic at the moment, but their works does suggest other ways of inducing Pax3 expression in human ESCs without the need of genetically modifying the cells.