title: R59949, a diacylglycerol kinase inhibitor, inhibits inducible nitric oxide production through decreasing transplasmalemmal L-arginine uptake in vascular smooth muscle cells.
abstract: Although diacylglycerol kinase (DGK) is known to be expressed in vascular smooth muscle cell, its functional significance remains to be clarified. We hypothesized that DGK is involved in the pathway of cytokine-induced nitric oxide (NO) production in vascular smooth muscle cells. The purpose of this study was to investigate the effects of R59949, a diacylglycerol kinase inhibitor, on inducible nitric oxide production in vascular smooth muscle cell. Cultured rat aortic smooth muscle cells (RASMCs) were used to elucidate the effects of R59949 on basal and interleukin-1β (IL-1β)-induced NO production. The effects of R59949 on protein and mRNA expression of induced nitric oxide synthase (iNOS) and on transplasmalemmal L-arginine uptake were also evaluated using RASMCs. Treatment of RASMCs with R59949 (10 μM) inhibited IL-1β (10 ng/ml)-induced NO production but not basal NO production. Neither protein nor mRNA expression level of iNOS after stimulation with IL-1β was significantly affected by R59949. Estimated enzymatic activities of iNOS in RASMCs were comparable in the absence and presence of R59949. Stimulation of RASMCs with IL-1β caused a marked increase in transplasmalemmal L-arginine uptake into RASMCs. L-Arginine uptake in the presence of IL-1β was markedly inhibited by R59949, while basal L-arginine uptake was not significantly affected by R59949. Both IL-1β-induced NO production and L-arginine uptake were abolished in the presence of cycloheximide (1 μM). The results indicate that R59949 inhibits inducible NO production through decreasing transplasmalemmal L-arginine uptake. DGK is suggested to be involved in cytokine-stimulated L-arginine transport and regulate its intracellular concentration in vascular smooth muscle cell.
authors.affiliation: Department of Environmental and Preventive Medicine, Hyogo College of Medicine, Mukogawa-cho 1-1, Nishinomiya, Hyogo, 663-8501, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Shimomura
authors.affiliation: Department of Anatomy and Cell Biology, Yamagata University Faculty of Medicine, Iida-nishi 2-2-2, Yamagata, 990-9585, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Nakano
authors.affiliation: Department of Anatomy and Cell Biology, Yamagata University Faculty of Medicine, Iida-nishi 2-2-2, Yamagata, 990-9585, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Goto
authors.affiliation: Department of Environmental and Preventive Medicine, Hyogo College of Medicine, Mukogawa-cho 1-1, Nishinomiya, Hyogo, 663-8501, Japan. wakabaya@hyo-med.ac.jp.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Wakabayashi
mesh_terms: D000818:Animals; D001120:Arginine / Q000378:metabolism*; D001692:Biological Transport; D002462:Cell Membrane / Q000187:drug effects* / Q000201:enzymology; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D019852:Diacylglycerol Kinase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D053583:Interleukin-1beta / Q000494:pharmacology; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000201:enzymology; D032389:Myocytes, Smooth Muscle / Q000187:drug effects* / Q000201:enzymology; D009569:Nitric Oxide / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism*; D010880:Piperidines / Q000494:pharmacology*; D052999:Quinazolinones / Q000494:pharmacology*; D017208:Rats, Wistar
chemical_list: D004791:Enzyme Inhibitors; D053583:Interleukin-1beta; D010880:Piperidines; D052999:Quinazolinones; C058544:R 59949; D009569:Nitric Oxide; D001120:Arginine; D003513:Cycloheximide; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D019852:Diacylglycerol Kinase
keywords: Amino acid transporter; Diacylglycerol kinase; L-Arginine; Nitric oxide; Protein kinase C; iNOS