title: Potential role of lipin-1 in exercise-induced mitochondrial biogenesis.
abstract: Endurance exercise induces mitochondrial biogenesis in skeletal muscle. It has been shown that lipin-1 acts as a transcriptional coactivator in liver, and stimulates gene expression of mitochondrial enzymes. We hypothesized that lipin-1 might be involved in exercise-induced mitochondrial biogenesis in skeletal muscle. The present investigation first demonstrated that lipin-1 mRNA in rat triceps muscle was increased by approximately 2-fold after an acute bout of endurance swimming exercise. Second, ectopic expression of lipin-1 in L6 myotube increased carnitine palmitoyltransferase-1 and delta-aminolevulinate synthase gene expression. Finally, lipin-1 mRNA expression in rat triceps muscle was significantly elevated at 6h after subcutaneous injections of 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) or clenbuterol, which are 5'-AMP-activated protein kinase (AMPK) and beta2-adrenergic receptor (beta2-AR) activators, respectively. These results may suggest that enhanced expression of lipin-1 is involved in exercise-induced mitochondrial enzyme adaptations, possibly through AMPK- and beta2-AR-related mechanisms.
authors.affiliation: Graduate School of Sport Sciences, Waseda University, 135-1, Horinouchi, Tokorozawa, Saitama, 359-1165, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Higashida
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Higuchi
authors.forename: Shin
authors.initials: S
authors.lastname: Terada
mesh_terms: D000624:5-Aminolevulinate Synthetase / Q000235:genetics; D000091162:AMP-Activated Protein Kinase Kinases; D058667:Adrenergic beta-3 Receptor Agonists; D000620:Aminoimidazole Carboxamide / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D002334:Carnitine O-Palmitoyltransferase / Q000235:genetics; D002976:Clenbuterol / Q000494:pharmacology; D004837:Epinephrine / Q000097:blood; D015870:Gene Expression; D008297:Male; D008931:Mitochondria, Muscle / Q000201:enzymology*; D018485:Muscle Fibers, Skeletal / Q000378:metabolism / Q000648:ultrastructure; D018482:Muscle, Skeletal / Q000187:drug effects / Q000201:enzymology* / Q000648:ultrastructure; D009638:Norepinephrine / Q000097:blood; D009687:Nuclear Proteins / Q000235:genetics / Q000502:physiology*; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D010805:Physical Conditioning, Animal; D010807:Physical Endurance / Q000235:genetics; D011494:Protein Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012265:Ribonucleotides / Q000494:pharmacology; D013550:Swimming; D014157:Transcription Factors / Q000096:biosynthesis
chemical_list: D058667:Adrenergic beta-3 Receptor Agonists; C530902:Lpin1 protein, rat; D009687:Nuclear Proteins; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; C501429:Ppargc1a protein, rat; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012265:Ribonucleotides; D014157:Transcription Factors; D000620:Aminoimidazole Carboxamide; D002334:Carnitine O-Palmitoyltransferase; D000624:5-Aminolevulinate Synthetase; D011494:Protein Kinases; D000091162:AMP-Activated Protein Kinase Kinases; C031143:AICA ribonucleotide; D009638:Norepinephrine; D002976:Clenbuterol; D004837:Epinephrine