title: all-trans-Retinoic acid increases nitric oxide synthesis by endothelial cells: a role for the induction of dimethylarginine dimethylaminohydrolase.
abstract: all-trans-Retinoic acid (atRA) has important effects on the developing and mature cardiovascular system. Nitric oxide (NO) production has been associated with the atRA-induced differentiation of neuronal cells, and we hypothesized that NO may also mediate certain actions of atRA in the cardiovascular system. We studied the effects of atRA on NO production by endothelial cells and determined whether regulation of enzymes responsible for metabolism of asymmetric dimethylarginine (ADMA) contributed to the effects seen. Murine endothelioma (sEnd.1) cells were incubated with or without atRA. Nitrite production was determined using the Griess reaction. The expression of NO synthase (NOS) and dimethylarginine dimethylaminohydrolase (DDAH) genes was determined by Northern blotting. A reporter gene assay was also used to study the effect of atRA on the DDAH II promoter. atRA significantly increased nitrite production by sEnd.1 cells despite no increase in eNOS expression. atRA also increased DDAH II gene expression and promoter activity and reduced the ratio of ADMA to symmetric dimethylarginine (SDMA) in culture medium. The DDAH inhibitor 4124W significantly reduced the induction of NO synthesis by atRA. The present study demonstrates that atRA increases NO synthesis in endothelial cells without increasing eNOS expression. atRA also increases the expression of DDAH II, the predominant DDAH isoform in endothelial cells. Our data suggests that the induction of NO synthesis by atRA may be facilitated by DDAH II. This pathway may help to explain some of the effects of atRA on the cardiovascular system.
authors.affiliation: Centre for Clinical Pharmacology, BHF Laboratories, University College London, United Kingdom.
authors.forename: Vinod
authors.initials: V
authors.lastname: Achan
authors.forename: Cam T L
authors.initials: CT
authors.lastname: Tran
authors.forename: Francesca
authors.initials: F
authors.lastname: Arrigoni
authors.forename: Guy St J
authors.initials: GS
authors.lastname: Whitley
authors.forename: James M
authors.initials: JM
authors.lastname: Leiper
authors.forename: Patrick
authors.initials: P
authors.lastname: Vallance
mesh_terms: D000581:Amidohydrolases / Q000235:genetics / Q000378:metabolism*; D001120:Arginine / Q000031:analogs & derivatives* / Q000378:metabolism* / Q000494:pharmacology; D015152:Blotting, Northern; D002460:Cell Line; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D004790:Enzyme Induction / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000378:metabolism / Q000494:pharmacology; D017930:Genes, Reporter; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III; D009573:Nitrites / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D014212:Tretinoin / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; D007527:Isoenzymes; D009573:Nitrites; D012333:RNA, Messenger; D009569:Nitric Oxide; D014212:Tretinoin; C018524:N,N-dimethylarginine; D001120:Arginine; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; D000581:Amidohydrolases; C059999:dimethylargininase