Proteome analysis of the dystrophin-deficient MDX diaphragm reveals a drastic increase in the heat shock protein cvHSP.
Duchenne muscular dystrophy is the most commonly inherited neuromuscular disorder in humans. Although the primary genetic deficiency of dystrophin in X-linked muscular dystrophy is established, it is not well-known how pathophysiological events trigger the actual fibre degeneration. We have therefore performed a DIGE analysis of normal diaphragm muscle versus the severely affected x-linked muscular dystrophy (MDX) diaphragm, which represents an established animal model of dystrophinopathy. Out of 2398 detectable 2-D protein spots, 35 proteins showed a drastic differential expression pattern, with 21 proteins being decreased, including Fbxo11-protein, adenylate kinase, beta-haemoglobin and dihydrolipoamide dehydrogenase, and 14 proteins being increased, including cvHSP, aldehyde reductase, desmin, vimentin, chaperonin, cardiac and muscle myosin heavy chain. This suggests that lack of sarcolemmal integrity triggers a generally perturbed protein expression pattern in dystrophin-deficient fibres. However, the most significant finding was the dramatic increase in the small heat shock protein cvHSP, which was confirmed by 2-D immunoblotting. Confocal fluorescence microscopy revealed elevated levels of cvHSP in MDX fibres. An immunoblotting survey of other key heat shock proteins showed a differential expression pattern in MDX diaphragm. Stress response appears to be an important cellular mechanism in dystrophic muscle and may be exploitable as a new approach to counteract muscle degeneration.
Doran
Philip
P
Department of Biology, National University of Ireland, Maynooth, Co. Kildare, Ireland.
Martin
Geraldine
G
Dowling
Paul
P
Jockusch
Harald
H
Ohlendieck
Kay
K
D000818:Animals; D003964:Diaphragm / Q000378:metabolism; D016189:Dystrophin / Q000172:deficiency / Q000235:genetics*; D015180:Electrophoresis, Gel, Two-Dimensional; D006360:Heat-Shock Proteins / Q000096:biosynthesis*; D006801:Humans; D051379:Mice; D018101:Mice, Inbred mdx; D018485:Muscle Fibers, Skeletal / Q000378:metabolism; D009137:Muscular Dystrophy, Animal / Q000378:metabolism*; D020388:Muscular Dystrophy, Duchenne / Q000378:metabolism*; D020543:Proteome / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D016189:Dystrophin; D006360:Heat-Shock Proteins; D020543:Proteome