Proliferation and Differentiation Potential of Adipose‐Derived Stem Cells Isolated from Dystrophin and Utrophin Double Knockout mice

Abstract

Duchenne muscular dystrophy (DMD) is a genetic disease characterized by progressive weakening of the skeletal, cardiac, and diaphragmatic muscles. Recent evidence has emerged implicating adult stem cell dysfunction in DMD histophathogenesis. Using utrophin/dystrophin double knockout (dys−/−utro−/−, dKO) mice, a DMD model that better emulates the human phenotype of the disease in mice, we determine if adipose derived stem cells (ADSCs) from dKO mice are affected in their proliferation and differentiation capacities compared to C57BL (wt) ADSCs. ADSCs were isolated from subcutaneous fat tissue of 6 week old dKO and wt mice and flow analysis confirmed positive expressions of Sca‐1, CD34, CD44 and CD29. Cell proliferation assay using a Live Cell Imaging system showed that dKO‐ADSCs were more active in proliferation than wt‐ADSCs. dKO‐ADSCs showed increased adipogenic, osteogenic, and chondrogenic potentials compared to wt‐ADSCs in vitro. Additional experiments revealed that transplanted dKO‐ADSCs displayed increased proliferation and survival and formed/accumulated more adipocytes in dKO gastrocnemius muscle (GM) compared to that in wt GM. These results suggest that dystrophic muscle milieu affects the stem cell niche, impacting stem cell function to be more active in proliferation and adipogenesis and this may partially explain ectopic fat deposition in skeletal muscle seen in advanced cases of DMD.