title: Sequential changes in the signal transduction responses of skeletal muscle following food deprivation.
abstract: Coping with reduced energy sources entails drastic morphological and functional changes in skeletal muscle, but the sequence of events required classification. We found that gastrocnemius muscle from food-deprived rats shows acute rises in peroxisome proliferator activated receptor (PPAR) gamma coactivator (PGC) -1alpha/PPAR delta nuclear protein and myosin heavy chain (MHC) Ib protein, while type I fibers accumulate and the muscle tissue appears redder. AMP levels, phosphorylation of both AMP-activated protein kinase (AMPK) and its downstream target acetyl coenzyme A carboxylase (ACC) are induced within 6 h. Rapidly increased MyoD mRNA levels are followed by an increase in uncoupling protein (UCP) 3 (UCP3) transcription. Increased serum fatty acid levels coincide with increases in mitochondrial UCP3 protein levels and fatty acid oxidation. Accompanying this is a decrease in AMPK phosphorylation, reversible upon nicotinic acid treatment, indicating that fatty acids may modulate this kinase's activity after the metabolic challenges posed by food deprivation.
authors.affiliation: Dipartimento di Scienze della Vita, Seconda Università degli Studi di Napoli, Via Vivaldi 43, 81100, Caserta, Italy.
authors.forename: Pieter
authors.initials: P
authors.lastname: de Lange
authors.forename: Paola
authors.initials: P
authors.lastname: Farina
authors.forename: Maria
authors.initials: M
authors.lastname: Moreno
authors.forename: Maurizio
authors.initials: M
authors.lastname: Ragni
authors.forename: Assunta
authors.initials: A
authors.lastname: Lombardi
authors.forename: Elena
authors.initials: E
authors.lastname: Silvestri
authors.forename: Lavinia
authors.initials: L
authors.lastname: Burrone
authors.forename: Antonia
authors.initials: A
authors.lastname: Lanni
authors.forename: Fernando
authors.initials: F
authors.lastname: Goglia
mesh_terms: D055372:AMP-Activated Protein Kinases; D000222:Adaptation, Physiological; D000249:Adenosine Monophosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D005508:Food Deprivation / Q000502:physiology*; D005786:Gene Expression Regulation; D008297:Male; D009097:Multienzyme Complexes / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism*; D017570:MyoD Protein / Q000378:metabolism; D018995:Myosin Heavy Chains / Q000378:metabolism; D047494:PPAR delta / Q000378:metabolism; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D009097:Multienzyme Complexes; D017570:MyoD Protein; D047494:PPAR delta; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; C501429:Ppargc1a protein, rat; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D014157:Transcription Factors; D000249:Adenosine Monophosphate; D000255:Adenosine Triphosphate; D017346:Protein Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases; D018995:Myosin Heavy Chains