Nitric oxide synthase in muscular dystrophies: a re-evaluation.
Duchenne and Becker muscular dystrophies (DMD and BMD) are associated with decreased total nitric oxide (NO). However, mechanisms leading to NO deficiency with consequent muscle-cell degeneration remain unknown. To address this issue, we examined skeletal muscles of DMD and BMD patients for co-expression of NO synthase (NOS) with nitrotyrosine and transcription factor CREB, as well as with enzymes engaged in NO signaling. Employing immunocytochemical labeling, Western blotting and RT-PCR, we found that, in contrast to the most commonly accepted view, neuronal NOS was not restricted to the sarcolemma and that muscles of DMD and BMD patients retained all three NOS isoforms with an up-regulation of the inducible NOS isoform, CREB and nitrotyrosine. We suggest that enhanced nitrotyrosine immunostaining in muscle fibers as well as in the vasculature of DMD and BMD specimens reflects massive oxidative stress, resulting in withdrawal of NO from its regular physiological course via the scavenging actions of superoxides.
Buchwalow
Igor B
IB
Gerhard Domagk Institute of Pathology, University of Muenster, Domagkstr. 17, 48149, Muenster, Germany. buchwalo@uni-muenster.de
Minin
Evgeny A
EA
Müller
Frank-Ulrich
FU
Lewin
Geertje
G
Samoilova
Vera E
VE
Schmitz
Wilhelm
W
Wellner
Maren
M
Hasselblatt
Martin
M
Punkt
Karla
K
Müller-Werdan
Ursula
U
Demus
Uta
U
Slezak
Jan
J
Koehler
Gabriele
G
Boecker
Werner
W
D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000378:metabolism; D000328:Adult; D001119:Arginase / Q000378:metabolism; D015153:Blotting, Western; D002470:Cell Survival / Q000502:physiology; D002675:Child, Preschool; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000502:physiology; D005260:Female; D005455:Fluorescent Antibody Technique; D006162:Guanylate Cyclase / Q000378:metabolism; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000096:biosynthesis; D008297:Male; D018482:Muscle, Skeletal / Q000201:enzymology / Q000378:metabolism; D009136:Muscular Dystrophies / Q000201:enzymology*; D020388:Muscular Dystrophy, Duchenne / Q000201:enzymology; D009569:Nitric Oxide / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D018384:Oxidative Stress / Q000502:physiology; D012313:RNA / Q000096:biosynthesis / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology; D014443:Tyrosine / Q000031:analogs & derivatives / Q000494:pharmacology
D017362:Cyclic AMP Response Element-Binding Protein; D007527:Isoenzymes; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine; D012313:RNA; D019001:Nitric Oxide Synthase; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D001119:Arginase; D006162:Guanylate Cyclase