Angiotensin II-induced vascular endothelial dysfunction through RhoA/Rho kinase/p38 mitogen-activated protein kinase/arginase pathway

• Published in: American Journal of Physiology: Cell Physiology Vol. 300; no. 5; p. C1181
• Main Authors: Shatanawi, Alia, Romero, Maritza J, Iddings, Jennifer A, Chandra, Surabhi, Umapathy, Nagavedi S, Verin, Alexander D, Caldwell, Ruth B, Caldwell, R William
• Format: Journal Article
• Language: English
• Published: United States 01-05-2011
• Subjects: 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine - analogs & derivatives; 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine - pharmacology; Amides - pharmacology; Angiotensin II - pharmacology; Angiotensin II - physiology; Angiotensin II Type 1 Receptor Blockers - pharmacology; Animals; Arginase - antagonists & inhibitors; Arginase - physiology; Boronic Acids - pharmacology; Cattle; Cell Line; Endothelial Cells; Endothelium, Vascular - drug effects; Endothelium, Vascular - enzymology; Endothelium, Vascular - physiopathology; Enzyme Inhibitors - pharmacology; GTP-Binding Protein alpha Subunits, G12-G13 - antagonists & inhibitors; GTP-Binding Protein alpha Subunits, Gq-G11 - antagonists & inhibitors; Imidazoles - pharmacology; Mice; p38 Mitogen-Activated Protein Kinases - antagonists & inhibitors; p38 Mitogen-Activated Protein Kinases - physiology; Phosphorylation; Pyridines - pharmacology; rho-Associated Kinases - antagonists & inhibitors; rho-Associated Kinases - physiology; RNA, Small Interfering - pharmacology; Signal Transduction - drug effects; Signal Transduction - physiology; Simvastatin - pharmacology
• ISSN: 1522-1563
• DOI: 10.1152/ajpcell.00328.2010

Enhanced vascular arginase activity impairs endothelium-dependent vasorelaxation by decreasing l-arginine availability to endothelial nitric oxide (NO) synthase, thereby reducing NO production. Elevated angiotensin II (ANG II) is a key component of endothelial dysfunction in many cardiovascular diseases and has been linked to elevated arginase activity. We determined signaling mechanisms by which ANG II increases endothelial arginase function. Results show that ANG II (0.1 μM, 24 h) elevates arginase activity and arginase I expression in bovine aortic endothelial cells (BAECs) and decreases NO production. These effects are prevented by the arginase inhibitor BEC (100 μM). Blockade of ANG II AT(1) receptors or transfection with small interfering RNA (siRNA) for Gα12 and Gα13 also prevents ANG II-induced elevation of arginase activity, but siRNA for Gαq does not. ANG II also elevates active RhoA levels and induces phosphorylation of p38 MAPK. Inhibitors of RhoA activation (simvastatin, 0.1 μM) or Rho kinase (ROCK) (Y-27632, 10 μM; H1152, 0.5 μM) block both ANG II-induced elevation of arginase activity and phosphorylation of p38 MAPK. Furthermore, pretreatment of BAECs with p38 inhibitor SB-202190 (2 μM) or transfection with p38 MAPK siRNA prevents ANG II-induced increased arginase activity/expression and maintains NO production. Additionally, inhibitors of p38 MAPK (SB-203580, 5 μg·kg(-1)·day(-1)) or arginase (ABH, 8 mg·kg(-1)·day(-1)) or arginase gene knockout in mice prevents ANG II-induced vascular endothelial dysfunction and associated enhancement of arginase. These results indicate that ANG II increases endothelial arginase activity/expression through Gα12/13 G proteins coupled to AT(1) receptors and subsequent activation of RhoA/ROCK/p38 MAPK pathways leading to endothelial dysfunction.