title: A DIGE approach for the assessment of rat soleus muscle changes during unloading: effect of acetyl-L-carnitine supplementation.
abstract: 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.
authors.affiliation: Department of Sciences and Biomedical Technologies, University of Milan, Segrate (MI), Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Moriggi
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Cassano
authors.forename: Michele
authors.initials: M
authors.lastname: Vasso
authors.forename: Daniele
authors.initials: D
authors.lastname: Capitanio
authors.forename: Chiara
authors.initials: C
authors.lastname: Fania
authors.forename: Clara
authors.initials: C
authors.lastname: Musicco
authors.forename: Vito
authors.initials: V
authors.lastname: Pesce
authors.forename: Maria Nicola
authors.initials: MN
authors.lastname: Gadaleta
authors.forename: Cecilia
authors.initials: C
authors.lastname: Gelfi
mesh_terms: 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
chemical_list: D009124:Muscle Proteins; D000108:Acetylcarnitine; D018995:Myosin Heavy Chains