Peroxynitrite inhibits the expression of G(i)alpha protein and adenylyl cyclase signaling in vascular smooth muscle cells.
We previously showed that S-nitroso-N-acetylpenicillamine, a nitric oxide donor, decreased the levels and functions of G(i)alpha proteins by formation of peroxynitrite (ONOO(-)) in vascular smooth muscle cells (VSMC). The present studies were undertaken to investigate whether ONOO(-) can modulate the expression of G(i)alpha protein and associated adenylyl cyclase signaling in VSMC. Treatment of A-10 and aortic VSMC with ONOO(-) for 24 h decreased the expression of G(i)alpha-2 and G(i)alpha-3, but not G(s)alpha, protein in a concentration-dependent manner; expression was restored toward control levels by (111)Mn-tetralis(benzoic acid porphyrin) and uric acid, but not by 1H[1,2,4]oxadiazole[4,3-a]quinoxaline-1-one (ODQ) and KT-5823. cGMP levels were increased by approximately 50% and 150% by 0.1 and 0.5 mM ONOO(-), respectively, and attenuated toward control levels by ODQ. In addition, 0.5 mM ONOO(-) attenuated the inhibition of adenylyl cyclase by ANG II and C-type atrial natriuretic peptide (C-ANP(4-23)), as well as the inhibition of forskolin-stimulated adenylyl cyclase activity by GTPgammaS, whereas, the G(s)-mediated stimulations were augmented. In addition, 0.5 mM ONOO(-) decreased phosphorylation of ERK1/2 and p38 MAP kinase and enhanced JNK phosphorylation but did not affect AKT1/3 phosphorylation. These results suggest that ONOO(-) decreased the expression of G(i) proteins and associated functions in VSMC through a cGMP-independent mechanism and may involve the MAP kinase signaling pathway.
Bassil
Marcel
M
Department of Physiology, Faculty of Medicine, University of Montreal, CP 6128, Succ. Centreville, Montreal, Quebec, Canada.
Li
Yuan
Y
Anand-Srivastava
Madhu B
MB
D000067956:Adenylyl Cyclase Inhibitors; D000818:Animals; D001013:Aorta, Thoracic / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D015153:Blotting, Western; D002227:Carbazoles / Q000494:pharmacology; D002478:Cells, Cultured; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000037:antagonists & inhibitors* / Q000096:biosynthesis*; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000096:biosynthesis / Q000502:physiology; D007211:Indoles / Q000494:pharmacology; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects / Q000502:physiology; D009126:Muscle Relaxation / Q000187:drug effects / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000502:physiology*; D010069:Oxadiazoles / Q000494:pharmacology; D030421:Peroxynitrous Acid / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D044140:Receptor, Angiotensin, Type 1 / Q000096:biosynthesis; D017461:Receptors, Atrial Natriuretic Factor / Q000096:biosynthesis; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*
C095284:1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one; D000067956:Adenylyl Cyclase Inhibitors; D002227:Carbazoles; D007211:Indoles; D010069:Oxadiazoles; D011810:Quinoxalines; D044140:Receptor, Angiotensin, Type 1; C073601:KT 5823; D030421:Peroxynitrous Acid; D020928:Mitogen-Activated Protein Kinases; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D019205:GTP-Binding Protein alpha Subunits, Gs; D017461:Receptors, Atrial Natriuretic Factor; C073616:atrial natriuretic factor receptor C