The super-healing MRL strain promotes muscle growth in muscular dystrophy through a regenerative extracellular matrix

Joseph G. O'Brien, Alexander B. Willis, Ashlee M. Long, Jason Kwon, Ga Hyun Lee, Frank W. Li, Patrick G.T. Page, Andy H. Vo, Michele Hadhazy, Melissa J. Spencer, Rachelle H. Crosbie, Alexis R. Demonbreun*, Elizabeth M. McNally*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Scopus citations

Abstract

The Murphy Roths Large (MRL) mouse strain has "super-healing"properties that enhance recovery from injury. In mice, the DBA/2J strain intensifies many aspects of muscular dystrophy, so we evaluated the ability of the MRL strain to suppress muscular dystrophy in the Sgcg-null mouse model of limb girdle muscular dystrophy. A comparative analysis of Sgcg-null mice in the DBA/2J versus MRL strains showed greater myofiber regeneration, with reduced structural degradation of muscle in the MRL strain. Transcriptomic profiling of dystrophic muscle indicated strain-dependent expression of extracellular matrix (ECM) and TGF-β signaling genes. To investigate the MRL ECM, cellular components were removed from dystrophic muscle sections to generate decellularized myoscaffolds. Decellularized myoscaffolds from dystrophic mice in the protective MRL strain had significantly less deposition of collagen and matrix-bound TGF-β1 and TGF-β3 throughout the matrix. Dystrophic myoscaffolds from the MRL background, but not the DBA/2J background, were enriched in myokines like IGF-1 and IL-6. C2C12 myoblasts seeded onto decellularized matrices from Sgcg-/- MRL and Sgcg-/- DBA/2J muscles showed the MRL background induced greater myoblast differentiation compared with dystrophic DBA/2J myoscaffolds. Thus, the MRL background imparts its effect through a highly regenerative ECM, which is active even in muscular dystrophy.

Original languageEnglish (US)
Article numbere173246
JournalJCI Insight
Volume9
Issue number3
DOIs
StatePublished - 2024

Funding

This study was supported by NIH grants AR052646, NS047726, and HL061322, and Parent Project Muscular Dystrophy.

ASJC Scopus subject areas

  • General Medicine

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