Tenascin-C expression in dystrophin-related muscular dystrophy.
The mdx mouse has a mutated dystrophin gene and is used as a model for the study of Duchenne muscular dystrophy (DMD). We investigated whether regenerating mdx skeletal muscle contains the extracellular matrix protein tenascin-C (TN-C), which is expressed in wound healing and nerve regeneration. Prior to the initiation of muscle degeneration, both normal and mdx mice displayed similar weak staining for TN-C in skeletal muscle, but by 3 weeks of age the mice differed substantially. TN-C was undetectable in normal muscle except at the myotendinous junction, while in dystrophic muscle, TN-C was prominent in degenerating/regenerating areas, but absent from undegenerated muscle. With increasing age, TN-C staining declined around stable regenerated mdx myofibers. TN-C was also observed in muscle from dogs with muscular dystrophy and in human boys with DMD. Therefore, in dystrophic muscle, TN-C expression may be stimulated by the degenerative process and remain upregulated unless the tissue undergoes successful regeneration.
Settles
D L
DL
Department of Cell Biology, Duke University, Durham, North Carolina 27710, USA.
Cihak
R A
RA
Erickson
H P
HP
D000818:Animals; D015153:Blotting, Western; D004285:Dogs; D016189:Dystrophin / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D009137:Muscular Dystrophy, Animal / Q000378:metabolism*; D009416:Nerve Regeneration; D019063:Tenascin / Q000032:analysis*; D014945:Wound Healing
D016189:Dystrophin; D019063:Tenascin