DMD Human iPSC-derived skeletal muscle cells recapitulate selective calcium dysregulation pathways

Summary This study investigates the functional characteristics of induced pluripotent stem cell-derived muscle cells (hiPSC-skMCs) from Duchenne muscular dystrophy (DMD) patients, focusing on their regulation of intracellular calcium concentration. DMD, a progressive muscle degenerative disease, arises from mutations in the dystrophin gene and is characterized by elevated intracellular calcium levels, exacerbating disease progression. This work highlights that DMD hiPSC-skMCs demonstrate unique calcium signatures with increased intracellular calcium compared to healthy counterparts. These cells also exhibit both heightened calcium response when stimulated by electrical fields or acetylcholine and more pronounced constitutive calcium entries. While RNAseq data from these cells reaffirmed known dysregulation mechanisms seen in other dystrophin-deficient models, certain pathways like purinergic or store-operated calcium entries did not show disruption in this DMD model. This discrepancy suggests that not all mechanisms observed in animal models may be equally relevant in human cases, pointing towards specific molecular targets that could be more effective for DMD treatment strategies.