title: Contractile protein expression is upregulated by reactive oxygen species in aorta of Goto-Kakizaki rat.
abstract: Although it is known that blood vessels undergo remodeling in type 2 diabetes (T2D), the signaling pathways that underlie the structural and functional changes seen in diabetic arteries remain unclear. Our objective was to determine whether the remodeling in type 2 diabetic Goto-Kakizaki (GK) rats is evoked by elevated reactive oxygen species (ROS). Our results show that aortas from GK rats produced greater force (P < 0.05) in response to stimulation with KCl and U46619 than aortas from Wistar rats. Associated with these changes, aortic expression of contractile proteins (measured as an index of remodeling) and the microRNA (miR-145), which act to upregulate transcription of contractile protein genes, was twofold higher (P < 0.05) in GK than Wistar (age-matched control) rats, and there was a corresponding increase in ROS and decrease in nitric oxide signaling. Oral administration of the antioxidant Tempol (1 mmol/l) to Wistar and GK rats reduced (P < 0.05) myocardin and calponin expression. Tempol (1 mmol/l) decreased expression of miR-145 in Wistar and GK rat aorta. To elucidate the mechanism through which ROS increases miR-145, we measured their levels in freshly isolated aorta and cultured aortic smooth muscle cells incubated for 12 h in the presence of H2O2 (300 μmol/l). H2O2 increased expression of miR-145, and there were corresponding nuclear increases in myocardin, a miR-145 target protein. Intriguingly, H2O2-induced expression of miR-145 was decreased by U0126 (10 μmol/l), a MEK1/2 inhibitor, and myocardin was decreased by anti-miR-145 (50 nmol/l) and U0126 (10 μmol/l). Our novel findings demonstrate that ROS evokes vascular wall remodeling and dysfunction by enhancing expression of contractile proteins in T2D.
authors.affiliation: Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, Alabama;
authors.forename: Sukrutha
authors.initials: S
authors.lastname: Chettimada
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Ata
authors.forename: Dhwajbahadur K
authors.initials: DK
authors.lastname: Rawat
authors.forename: Salil
authors.initials: S
authors.lastname: Gulati
authors.forename: Andrea G
authors.initials: AG
authors.lastname: Kahn
authors.forename: John G
authors.initials: JG
authors.lastname: Edwards
authors.forename: Sachin A
authors.initials: SA
authors.lastname: Gupte
mesh_terms: D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000378:metabolism* / Q000473:pathology; D002070:Butadienes / Q000494:pharmacology; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D003497:Cyclic N-Oxides / Q000494:pharmacology; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism / Q000473:pathology; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism; D009218:Myosins / Q000235:genetics / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D009570:Nitriles / Q000494:pharmacology; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011189:Potassium Chloride / Q000494:pharmacology; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013113:Spin Labels; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D015854:Up-Regulation; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D000096985:Calponins; D000099251:Myocardin
chemical_list: D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D002070:Butadienes; D002135:Calcium-Binding Proteins; D003497:Cyclic N-Oxides; D035683:MicroRNAs; D008840:Microfilament Proteins; D009218:Myosins; D009569:Nitric Oxide; D009570:Nitriles; D009687:Nuclear Proteins; D011189:Potassium Chloride; D047428:Protein Kinase Inhibitors; D017382:Reactive Oxygen Species; D013113:Spin Labels; D015534:Trans-Activators; D014662:Vasoconstrictor Agents; D000096985:Calponins; D000099251:Myocardin; C542511:MIRN145 microRNA, rat; C113580:U 0126; C001803:tempol
keywords: aortic smooth muscle cell line; hydrogen peroxide; microRNA; smooth muscle phenotype; superoxide; type 2 diabetes; vascular smooth muscle