A recently discovered population of stem cells, dubbed mesangioblasts, can repair muscle tissue and improve motor ability in a mouse model of limb-girdle muscular dystrophy.

Credit: Reprinted with permission from AAAS

Sampaolesi et al. found that mesangioblasts injected into the mice, which were deficient in the α-sarcoglycan gene, restored expression of α-sarcoglycan and improved muscle fiber morphology several months after treatment. In the 10 July Science they also report that the treated animals were able to walk on a rotating wheel for longer than untreated animals, although not as long as healthy mice. The authors obtained similar results with α-sarcoglycan deficient mesangioblasts corrected with the α-sarcoglycan gene and expanded in culture (GFP-α-sarcoglycan shown here in treated area after 4 months, untreated, contralateral area in insert).

Mesangioblasts are a class of vessel-associated stem cells that can differentiate into most mesodermal tissues. In mice they are found in the fetus, and, at much lower frequency, in adults. The authors speculate that mesangioblasts might also hold promise for other types of dystrophies especially in combination with techniques of gene repair. Methods such as exon skipping, described by Lu et al. (pages 1009–1014) and Tidball and Spencer (pages 997–998) could potentially be used in culture to correct the primary defect in mesangioblasts prior to injection.