In Duchenne muscular dystrophy, increased muscle fragility appears to be the cause of muscle stem cell depletion, which leads to muscle wasting and thus muscle weakness. Chronic voluntary exercise can reduce some of the susceptibility to contraction-induced muscle damage, that is muscle fragility.
In this paper, a French team involving researchers from the institute studied the effect of overexpression of the Prox1 gene (Prospero-related homeobox factor 1) on fragility in chronically exercised mdx mice, knowing that Prox1 favours slower type fibres in healthy mice and slower fibres are less fragile in mdx muscles.
The results show that while Prox1 overexpression increases the beneficial effect of chronic exercise on muscle fragility in mdx mice, it also reduces absolute maximal strength. The authors conclude that the potential clinical benefit of Prox1 overexpression in exercised dystrophic muscle therefore merits further study.
