title: Angiotensin II elevates nitric oxide synthase 3 expression and nitric oxide production via a mitogen-activated protein kinase cascade in ovine fetoplacental artery endothelial cells.
abstract: Normal pregnancy is associated with high angiotensin II (ANG II) concentrations in the maternal and fetal circulation. These high levels of ANG II may promote production vasodilators such as nitric oxide (NO). ANG II receptors are expressed in ovine fetoplacental artery endothelial (OFPAE) cells and mediate ANG II-stimulated OFPAE cell proliferation. Herein, we tested whether ANG II stimulated NO synthase 3 (NOS3, also known as eNOS) expression and total NO (NO(x)) production via activation of mitogen-activated protein kinase 3/1 (MAPK3/1, also known as ERK1/2) in OFPAE cells. ANG II elevated (P < 0.05) eNOS protein, but not mRNA levels with a maximum effect at 10 nM. ANG II also dose dependently increased (P < 0.05) NO(x) production with a maximal effect at doses of 1-100 nM. Activation of ERK1/2 by ANG II was determined by immunocytochemistry and Western blot analysis. ANG II rapidly induced positive staining for phosphorylated ERK1/2, appearing in cytosol after 1-5 min of ANG II treatment, accumulating in nuclei after 10 min, and disappearing at 15 min. ANG II increased (P < 0.05) phosphorylated ERK1/2 protein levels. Activation of ERK1/2 was confirmed by an immunocomplex kinase assay using ELK1 as a substrate. PD98059 significantly inhibited ANG II-induced ERK1/2 activation, and the ANG II-elevated eNOS protein levels but only partially reduced ANG II-increased NO(x) production. Thus, in OFPAE cells, the ANG II increased NO(x) production is associated with elevated eNOS protein expression, which is mediated at least in part via activation of the mitogen-activated protein kinase kinase1 and kinase2 (MAP2K1 and MAP2K2, known also as MEK1/2)/ERK1/2 cascade. Together with our previous observation that ANG II stimulates OFPAE cell proliferation, these data suggest that ANG II is a key regulator for both vasodilation and angiogenesis in the ovine fetoplacenta.
authors.affiliation: Department of Obstetrics and Gynecology, Perinatal Research Laboratories, University of Wisconsin, Madison, Wisconsin 53715, USA. jzheng@wisc.edu
authors.forename: Jing
authors.initials: J
authors.lastname: Zheng
authors.forename: YunXia
authors.initials: Y
authors.lastname: Wen
authors.forename: Dong-Bao
authors.initials: DB
authors.lastname: Chen
authors.forename: Ian M
authors.initials: IM
authors.lastname: Bird
authors.forename: Ronald R
authors.initials: RR
authors.lastname: Magness
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology* / Q000502:physiology; D000818:Animals; D001158:Arteries / Q000166:cytology / Q000187:drug effects; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005333:Fetus / Q000098:blood supply; D005419:Flavonoids / Q000494:pharmacology; D048369:MAP Kinase Kinase 1 / Q000187:drug effects / Q000378:metabolism; D048370:MAP Kinase Kinase 2 / Q000187:drug effects / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D019950:Mitogen-Activated Protein Kinase 1 / Q000187:drug effects / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III; D010920:Placenta / Q000166:cytology* / Q000187:drug effects; D011247:Pregnancy; D034561:Sheep, Domestic
chemical_list: D004791:Enzyme Inhibitors; D005419:Flavonoids; D000804:Angiotensin II; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; C482129:Map2k2 protein, mouse; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one