The mdx mouse diaphragm reproduces the degenerative changes of Duchenne muscular dystrophy

HH Stedman, HL Sweeney, JB Shrager, HC Maguire… - Nature, 1991 - nature.com
HH Stedman, HL Sweeney, JB Shrager, HC Maguire, RA Panettieri, B Petrof, M Narusawa…
Nature, 1991nature.com
ALTHOUGH murine X-linked muscular dystrophy (mdx) and Duchenne muscular dystrophy
(DMD) are genetically homologous and both characterized by a complete absence of
dystrophin1, 2, the limb muscles of adult mdx mice suffer neither the detectable weakness
nor the progressive degeneration that are features of DMD3–8. Here we show that the mdx
mouse diaphragm exhibits a pattern of degeneration, fibrosis and severe functional deficit
comparable to that of DMD limb muscle, although adult mice show no overt respiratory …
Abstract
ALTHOUGH murine X-linked muscular dystrophy (mdx) and Duchenne muscular dystrophy (DMD) are genetically homologous and both characterized by a complete absence of dystrophin1,2, the limb muscles of adult mdx mice suffer neither the detectable weakness nor the progressive degeneration that are features of DMD3–8. Here we show that the mdx mouse diaphragm exhibits a pattern of degeneration, fibrosis and severe functional deficit comparable to that of DMD limb muscle, although adult mice show no overt respiratory impairment. Progressive functional changes include reductions in strength (to 13.5% of control by two years of age), elasticity, twitch speed and fibre length. The collagen density rises to at least seven times that of control diaphragm and ten times that of mdx hind-limb muscle. By 1.5 years of age, similar but less severe histological changes emerge in the accessory muscles of respiration. On the basis of these findings, we propose that dystrophin deficiency alters the threshold for work-induced injury. Our data provide a quantitative framework for studying the pathogenesis of dystrophy and extend the application of the mdx mouse as an animal model.
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