A DIGE approach for the assessment of rat soleus muscle changes during unloading: effect of acetyl-L-carnitine supplementation.
After hind limb suspension, a remodeling of postural muscle phenotype is observed. This remodeling results in a shift of muscle profile from slow-oxidative to fast-glycolytic. These metabolic changes and fiber type shift increase muscle fatigability. Acetyl-L-carnitine (ALCAR) influences the skeletal muscle phenotype of soleus muscle suggesting a positive role of dietary supplementation of ALCAR during unloading. In the present study, we applied a 2-D DIGE, mass spectrometry and biochemical assays, to assess qualitative and quantitative differences in the proteome of rat slow-twitch soleus muscle subjected to disuse. Meanwhile, the effects of ALCAR administration on muscle proteomic profile in both unloading and normal-loading conditions were evaluated. The results indicate a modulation of troponin I and tropomyosin complex to regulate fiber type transition. Associated, or induced, metabolic changes with an increment of glycolytic enzymes and a decreased capacity of fat oxidation are observed. These metabolic changes appear to be counteracted by ALCAR treatment, which restores the mitochondrial mass and decreases the glycolytic enzyme expression, suggesting a normalization of the metabolic shift observed in unloaded animals. This normalization is accompanied by a maintenance of body weight and seems to prevent a switch of fiber type.
Moriggi
Manuela
M
Department of Sciences and Biomedical Technologies, University of Milan, Segrate (MI), Italy.
Cassano
Pierluigi
P
Vasso
Michele
M
Capitanio
Daniele
D
Fania
Chiara
C
Musicco
Clara
C
Pesce
Vito
V
Gadaleta
Maria Nicola
MN
Gelfi
Cecilia
C
D000108:Acetylcarnitine / Q000494:pharmacology*; D000818:Animals; D015180:Electrophoresis, Gel, Two-Dimensional; D019417:Hindlimb Suspension / Q000502:physiology*; D008297:Male; D008931:Mitochondria, Muscle / Q000187:drug effects; D009124:Muscle Proteins / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000187:drug effects / Q000502:physiology*; D018995:Myosin Heavy Chains / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D009124:Muscle Proteins; D000108:Acetylcarnitine; D018995:Myosin Heavy Chains