MicroRNA expression profile of fibro-adipogenic progenitors in Duchenne muscular dystrophy reveals dysregulation of adipogenesis-related microRNAs

<title>Abstract</title> <p> Background Duchenne muscular dystrophy (DMD) is characterized by progressive muscle degeneration and replacement of muscle fibers with fat and fibrotic tissue. Intramuscular fat deposition negatively impacts muscle function and regeneration. Fibro-adipogenic progenitors (FAPs) drive this fat deposition and fibrosis by differentiating into adipocytes and fibroblasts. Recent studies have highlighted the role of microRNAs (miRNAs) in regulating FAP fate in murine models, yet the miRNA landscape of FAPs from patients with DMD remains poorly understood. Results Using small RNA sequencing of FAPs isolated from patients with DMD and control individuals cultured under basal and adipogenic conditions, we identified eight miRNAs differentially expressed between DMD and control FAPs, as well as eight miRNAs altered during early adipogenic differentiation of DMD FAPs. Integration of small RNA and bulk RNA sequencing data enabled prediction of miRNA target genes and pathway enrichment analysis. Among the dysregulated miRNAs, <italic>hsa-miR-196a-5p</italic> was significantly downregulated in both FAPs and muscle biopsies from patients with DMD, highlighting its altered expression in dystrophic conditions <italic>in vivo</italic> . Transfection of DMD FAPs with miRNA mimics, followed by qRT-PCR analysis, showed that increased <italic>hsa-miR-196a-5p</italic> expression during adipogenic differentiation reduced the expression of key adipogenic regulators, including <italic>CEBPA, PPARG</italic> , and <italic>FABP4</italic> , and inhibited the homeobox genes <italic>HOXC8</italic> and <italic>HOXC9</italic> . Conclusion These findings reveal an altered miRNA profile of FAPs from patients with DMD and identify <italic>hsa-miR-196a-5p</italic> as a novel regulator of FAP adipogenic differentiation, potentially through HOX gene pathways. This work provides new insight into miRNA-mediated control of adipogenic differentiation of FAPs in DMD. </p>