Neuronal NOS is dislocated during muscle atrophy in amyotrophic lateral sclerosis.
Previously, we demonstrated that neuronal nitric oxide synthase (nNOS) is activated and promotes muscle atrophy in skeletal muscle during tail suspension, a model of unloading and denervation. Here, we examined patients with amyotrophic lateral sclerosis (ALS) and mutant (H46R) SOD1 transgenic (Tg) mice model using immunohistochemistry, Western blotting and real time PCR. We found cytoplasmic nNOS staining of angulated muscle fibers in patients with ALS. We also examined mutant SOD1 Tg mice and found cytoplasmic nNOS staining even before the onset of clinical muscle atrophy. In the Tg mice, nNOS was largely extracted with 100 mM NaCl and barely detected in the pellet fraction, suggesting fragile anchoring of nNOS to the sarcolemma. We also showed an elevated expression of atrogin-1, key molecules in muscle atrophy at the end stage. A common nNOS dislocation/atrogin-1/muscle atrophy pathway among tail suspension, denervation and ALS is suggested. nNOS modulation therapy may be beneficial in several types of muscle atrophy.
Suzuki
Naoki
N
Department of Neurology, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan. naoki@em.neurol.med.tohoku.ac.jp
Mizuno
Hideki
H
Warita
Hitoshi
H
Takeda
Shin'ichi
S
Itoyama
Yasuto
Y
Aoki
Masashi
M
D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000201:enzymology* / Q000378:metabolism; D000818:Animals; D003593:Cytoplasm / Q000201:enzymology / Q000378:metabolism; D004195:Disease Models, Animal; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D008875:Middle Aged; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000201:enzymology* / Q000378:metabolism; D009133:Muscular Atrophy / Q000201:enzymology* / Q000378:metabolism; D052248:Nitric Oxide Synthase Type I / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D044843:SKP Cullin F-Box Protein Ligases / Q000378:metabolism; D012508:Sarcolemma / Q000201:enzymology / Q000378:metabolism; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D000072105:Superoxide Dismutase-1; D000070584:Tripartite Motif Proteins; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism
D009124:Muscle Proteins; D012333:RNA, Messenger; C000606290:SOD1 protein, human; D000070584:Tripartite Motif Proteins; C496320:NOS1 protein, human; D052248:Nitric Oxide Synthase Type I; C496321:Nos1 protein, mouse; C000606291:Sod1 protein, mouse; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; C486691:Fbxo32 protein, mouse; D044843:SKP Cullin F-Box Protein Ligases; C499084:Trim63 protein, mouse; D044767:Ubiquitin-Protein Ligases