A promotive effect for halofuginone on membrane repair and synaptotagmin-7 levels in muscle cells of dysferlin-null mice

Hila Barzilai-Tutsch, Melissa Dewulf, Christophe Lamaze, Gillian Butler Browne, Mark Pines, Orna Halevy

Research output: Contribution to journalArticleResearchpeer-review

6 Citations (Scopus)

Abstract

In the absence of dysferlin, skeletal muscle cells fail to reseal properly after injury, resulting in slow progress of the dysferlinopathy muscular dystrophy (MD). Halofuginone, a leading agent in preventing fibrosis in MDs, was tested for its effects on membrane resealing post-injury. A hypo-osmotic shock assay on myotubes derived from wild-type (Wt) and dysferlin-null (dysf -/- ) mice revealed that pre-treatment with halofuginone reduces the percentage of membrane-ruptured myotubes only in dysf -/- myotubes. In laser-induced injury of isolated myofibers, halofuginone decreased the amount of FM1-43 at the injury site of dysf -/- myofibers while having no effect on Wt myofibers. These results implicate halofuginone in ameliorating muscle-cell membrane integrity in dysf -/- mice. Halofuginone increased lysosome scattering across the cytosol of dysf -/- primary myoblasts, in a protein kinase/extracellular signal-regulated protein kinase and phosphoinositide 3 kinase/Akt-dependent manner, in agreement with an elevation in lysosomal exocytotic activity in these cells. A spatial- and age-dependent synaptotagmin-7 (Syt-7) expression pattern was shown in dysf -/- versus Wt mice, suggesting that these pattern alterations are related to the disease progress and that sytnaptotagmin-7 may be compensating for the lack of dysferlin at least with regard to membrane resealing post-injury. While halofuginone did not affect patch-repair-complex key proteins, it further enhanced Syt-7 levels and its spread across the cytosol in dysf -/- myofibers and muscle tissue, and increased its colocalization with lysosomes. Together, the data imply a novel role for halofuginone in membrane-resealing events with Syt-7 possibly taking part in these events.

Original languageEnglish
Pages (from-to)2817-2829
Number of pages13
JournalHuman Molecular Genetics
Volume27
Issue number16
DOIs
Publication statusPublished - 15 Aug 2018
Externally publishedYes

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