Multi-modal analysis of satellite cells reveals early impairments at pre-contractile stages of myogenesis in Duchenne muscular dystrophy
Recent studies on the role of myogenic satellite cells (SC) in Duchenne muscular dystrophy (DMD) documented altered division capacities and impaired regeneration potential of SC in DMD patients and animal models. It remains unknown however, if SC-intrinsic effects trigger these deficiencies at pre-contractile stages of myogenesis rather than resulting from the pathologic environment. Addressing this, we isolated SC from muscle biopsies of a porcine DMD model for characterization. Traction force microscopy (TFM) revealed that DMD SC produce a significantly higher strain energy than wild-type cells (WT; 0.136 ± 0.016 µJ vs. 0.057 ± 0.008 µJ). By RNA-seq, we identified 1,390 differentially expressed genes and proteomics measurements detected 1,261 proteins with altered abundance in DMD vs. WT. Dysregulated pathways uncovered by Gene Ontology (GO) enrichment analysis included sarcomere organization, focal adhesion, and response to hypoxia. We integrated the data using multi-omics factor analysis (MOFA) and identified five factors accounting for the variance with an overall higher contribution of the transcriptomic (61.95 %) than the proteomic data (54.02 %). Our findings suggest SC impairments to result from their own genetic abnormality rather than environmental influences and the observed biological changes are independent and not reactive to the pathological surrounding of DMD muscle. Overall design: Gene expression analysis of RNA-seq data of myogenic SC derived from a translational porcine model for DMD compared to their healthy WT counterpart. Cells were harvested for sequencing during proliferation (PROL) and after differentiation into multinucleated myotubes (DIFF)