H19 Compromises Muscle Regeneration by Driving Satellite Cell Dysfunction and Persistent Inflammation

Background: Long non-coding RNA H19 is abundantly expressed in stem cells and has emerged as a key regulator of the balance between stem cell self-renewal and differentiation. Growing evidence highlights its involvement in multiple developmental and pathological contexts; however, its role in skeletal muscle regeneration remains largely unexplored. We hypothesized that aberrant H19 expression disrupts effective muscle repair by directly inhibiting satellite cell activation, proliferation, and myogenic differentiation. Methodology: Homozygous H19 imprinting control region (ICR) floxed male mice were crossed with heterozygous Pax7-CreER female mice to generate satellite cell–specific H19 overexpression (H19 OE) and control mice respectively. Skeletal muscle injury was induced in the tibialis anterior (TA) muscle, and tissue samples were collected at 3, 7, and 14 days post-injury (dpi). Western blotting, RT-qPCR, histological staining, and immunofluorescence were used to assess gene expression, protein abundance, and regenerative outcomes. Results: H19 OE impaired muscle regeneration by reducing key trophic and pro-myogenic factors, including Igf1, Wnt1, Wnt3a, and Wnt5a, as well as decreasing desmin protein, which suppressed satellite cell proliferation and myogenic activity. H19 OE profoundly dysregulated the inflammatory response during regeneration. At 7 days post-injury (dpi), H19 OE exhibited elevated levels of pro-inflammatory cytokines accompanied by a reduction in anti-inflammatory cytokines, suggesting a failure to properly resolve inflammation. This persistent inflammatory state is known to exacerbate fibrogenesis and further suppress satellite cell-mediated repair. Importantly, H19 OE also altered the dynamics of fibro-adipogenic progenitors (FAPs), key regulators of the muscle regenerative microenvironment. At 14 dpi, H19 OE muscles displayed increased accumulation of FAPs, which was attributed to reduced FAP apoptosis rather than enhanced proliferation. The prolonged survival and accumulation of FAPs likely contributed to sustained fibrosis and impaired resolution of the regenerative process. H19 OE promoted a pronounced fibrotic response within regenerating muscle. This was evidenced by increased expression of fibrogenic markers, including collagen type I (COL1A) and TCF4, along with enhanced activation of TGF-β signaling, a central driver of extracellular matrix deposition and fibroblast activation. These changes indicate a shift in the regenerative niche toward a pro-fibrotic microenvironment that is unfavorable for myofiber regeneration. Conclusions: Overall, these findings show that H19 impairs muscle regeneration by suppressing the myogenic activity of satellite cells and prolonging inflammation, thereby promoting fibrosis. These data suggest H19 as a potential therapeutic target for improving muscle repair. Funding sources: This research was funded by the National Institute of Child Health and Human Development through research grant R01HD067449. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.