Duchenne muscular dystrophy (DMD) is still an untreatable lethal X-linked disorder affecting1 in 3500 male births. It is caused by the absence of muscle dystrophin due to mutations in the dystrophin gene. The potential regenerative capacity as well as immune privileged properties of mesenchymal Stem Cells (MSC) has been under investigation for many years in an attempt to treat DMD. One of the questions to be addressed is whether stem cells from distinct sources have comparable clinical efficacy when injected in murine or canine muscular dystrophy animal models. Many studies comparing different stem cells from various sources have been reported but these cells were obtained from different donors and thus with different genetic backgrounds. Here, the authors investigated whether human pericytes obtained from 4 different tissues (muscle, adipose tissue, fallopian tube and endometrium) from the same donor have a similar clinical impact when injected in double mutant Utrn tm1Ked Dmd mdx /J mice, a clinically relevant model for DMD. After a weekly regimen of intraperitoneal injections of 106 cells per 8 weeks, they evaluated the motor ability as well as the life span of the treated mice, compared to controls. The results demonstrated that only adipose tissue derived pericytes are able to significantly increase the life span (39 days on average) of affected mice. Microarray analysis showed an inhibition of the interferon pathway by adipose derived pericytes. These data suggest that the clinical benefit associated with intraperitoneal injections of these adult stem cells is related to immune modulation rather than tissue regeneration.
