Muscle stem cells in Duchenne muscular dystrophy exhibit molecular impairments and altered cell fate trajectories impacting regenerative capacity
Satellite cells are muscle-resident stem cells that maintain and repair muscle. Increasing evidence supports the contributing role of satellite cells in Duchenne muscular dystrophy (DMD), a lethal degenerative muscle disease caused by loss of dystrophin protein. We used single cell RNA-sequencing (scRNA-seq) to determine how dystrophin deficiency impacts satellite cell heterogeneity and function. scRNA-seq was performed in satellite cells from mdx and D2-mdx DMD mouse models. DMD satellite cells were enriched in myogenic progenitor clusters and a unique DMD enriched cluster. DMD satellite cells and myogenic progenitors exhibited distinct impairments, including cell death and senescence, respectively. Moreover, dystrophic satellite cells express an impaired myogenic differentiation gene signature and are stalled in their differentiation capacity. We found that inducing autophagy led to enhanced differentiation of dystrophic progenitors. Our findings provide insight into the molecular pathways that are dysregulated in DMD satellite cells and suggest molecular targets to enhance their regenerative capacity. Overall design: Satellite cells from DMD (mdx and D2-mdx) and their WT counterpart (B10 and DBA) mice were isolated by Fluorescence-activated cell sorting (FACS) (ITGA7+/VCAM+/Lin-) and subjected to single cell transcriptomic sequencing