Thrombin stimulates human endothelial arginase enzymatic activity via RhoA/ROCK pathway: implications for atherosclerotic endothelial dysfunction
Details
Serval ID
serval:BIB_9EDC1ED4DD11
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Thrombin stimulates human endothelial arginase enzymatic activity via RhoA/ROCK pathway: implications for atherosclerotic endothelial dysfunction
Journal
Circulation
ISSN
1524-4539 (Electronic)
Publication state
Published
Issued date
12/2004
Volume
110
Number
24
Pages
3708-14
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Dec 14
Research Support, Non-U.S. Gov't --- Old month value: Dec 14
Abstract
BACKGROUND: Arginase competes with endothelial nitric oxide synthase (eNOS) for the substrate l-arginine and decreases NO production. This study investigated regulatory mechanisms of arginase activity in endothelial cells and its role in atherosclerosis. METHODS AND RESULTS: In human endothelial cells isolated from umbilical veins, thrombin concentration- and time-dependently stimulated arginase enzymatic activity, reaching a 1.9-fold increase (P<0.001) at 1 U/mL for 24 hours. The effect of thrombin was prevented by C3 exoenzyme or the HMG-CoA reductase inhibitor fluvastatin, which inhibit RhoA, or by the ROCK inhibitors Y-27632 and HA-1077. Adenoviral expression of constitutively active RhoA or ROCK mutants enhanced arginase activity (approximately 3-fold, P<0.001), and the effect of active RhoA mutant was inhibited by the ROCK inhibitors. Neither thrombin nor the active RhoA/ROCK mutants affected arginase II protein level, the only isozyme detectable in the cells. Moreover, a significantly higher arginase II activity (1.5-fold, not the protein level) and RhoA protein level (4-fold) were observed in atherosclerotic aortas of apoE-/- compared with wild-type mice. Interestingly, l-arginine (1 mmol/L), despite a significantly higher eNOS expression in aortas of apoE-/- mice, evoked a more pronounced contraction, which was reverted to a greater vasodilation by the arginase inhibitor l-norvaline (20 mmol/L) compared with the wild-type animals (n=5, P<0.001). CONCLUSIONS: Thrombin enhances arginase activity via RhoA/ROCK in human endothelial cells. Higher arginase enzymatic activity is involved in atherosclerotic endothelial dysfunction in apoE-/- mice. Targeting vascular arginase may represent a novel therapeutic possibility for atherosclerosis.
Keywords
Animals
Aorta, Thoracic/physiopathology
Apolipoproteins E/genetics
Arginase/*metabolism
Arteriosclerosis/*enzymology/physiopathology
Cells, Cultured
Endothelial Cells/enzymology
Endothelium, Vascular/*enzymology/physiopathology
Enzyme Activation
Humans
Intracellular Signaling Peptides and Proteins
Isoenzymes/metabolism
Male
Mice
Mice, Inbred C57BL
Mice, Knockout
Mutation
Nitric Oxide Synthase/biosynthesis
Nitric Oxide Synthase Type II
Nitric Oxide Synthase Type III
Protein-Serine-Threonine Kinases/antagonists &
inhibitors/genetics/*physiology
Signal Transduction
Thrombin/*physiology
Umbilical Veins/cytology
rhoA GTP-Binding Protein/antagonists & inhibitors/genetics/*physiology
Pubmed
Web of science
Open Access
Yes
Create date
17/01/2008 17:38
Last modification date
20/08/2019 16:05