Nogo expression in muscle correlates with amyotrophic lateral sclerosis severity

Abstract
Nogo, a protein inhibiting axonal regeneration, exhibits a characteristic isoform‐specific pattern of expression in skeletal muscle of transgenic mice and patients with amyotrophic lateral sclerosis. Here, the increased levels of Nogo‐A or Nogo‐B in muscle biopsies of 15 amyotrophic lateral sclerosis patients significantly correlated with the severity of clinical disability and with the degree of muscle fiber atrophy. Nogo‐A immunoreactivity was observed selectively in atrophic slow‐twitch type I fibers. These results suggest that Nogo expression in muscle is a marker of amyotrophic lateral sclerosis severity. Ann Neurol 2005;57:553–556