Cell & Stem Cell Research

Duchenne-muscular-dystrophy (DMD) is the commonest muscular-dystrophy caused by the absence of dystrophin. Stem-celltherapy in DMD is one of the more promising-approaches for treatment. Multipotent-stem-cells residing in the hair-folliclepapilla are highly-plastic and are reprogrammable to bone, cartilage, haematopoietic and muscle. Dermal-papilla-cells (DPC) from the hair-follicles of mouse-whisker-pad were microdissected and cultured. We showed that DPC undergo myogenic-differentiation when co-cultured with different types of myoblasts including normal and dystrophic human-myoblasts. Lamin A/C staining was used to distinguish DPC and myoblast-derived myonuclei inside myotubes. DPC incorporated into myotubes and up-regulated the muscle-marker myogenin in co-culture with human-myoblasts, suggesting that DPC fully underwent myogenic-differentiation in these co-cultures. DPC incorporation-efficiency was low in all co-cultures and differed significantly between various types of myoblast; however, no significant difference was observed between normal and dystrophic human-myoblasts. These encouraging-findings suggested that the altered properties of dystrophic-myoblasts did not compromise the myogenic-differentiation of DPC in-vitro,supporting their in-vivo application and possible therapeutic-potential. The in-vitro effects of galectin-1, reversine and activation of the Shh signaling-pathway via. recombinant Shh and purmorphamine, on DPC myogenic-differentiation was also evaluated. None of the treatments increased myogenin-expression in DPC; but, triggering Shh-signaling produced a dose-dependent-pattern, whereby lower-levels of signaling promoted myogenic-differentiation while higher-levels inhibited it. Activating Shh-signaling upstream of Smo via. purmorphamine, induced a biphasic differentiative-response; however, the application of rShh hindered the differentiation of both cell types. Thus, murine-DPC are a readily-accessible-source of stem-cells that can undergo myogenic-differentiation in-vitro. We aim to improve their differentiation-efficacy to make them suitable-candidates for therapeutic-applications in muscle-wastingdisorders.