title: Exogenous nitric oxide stimulates cell proliferation via activation of a mitogen-activated protein kinase pathway in ovine fetoplacental artery endothelial cells.
abstract: Sodium nitroprusside (SNP), a nitric oxide (NO) donor and a nitrovasodilator drug used for patients with hypertensive crisis, has been shown to promote angiogenesis. However, direct evidence showing the involvement of NO in the SNP-induced angiogenesis is not available. Accordingly, we assessed whether NO generated from SNP-stimulated ovine fetoplacental artery endothelial (OFPAE) cell proliferation via activation of mitogen-activated protein kinase 3/1 (MAPK3/1, also termed ERK1/2). We observed that SNP dose dependently stimulated (P < 0.05) cell proliferation with a maximal effect at 1 microM and that SNP rapidly (<or=15 min) phosphorylated (P < 0.05) MAPK3/1 but not v-akt murine thymoma viral oncogene homolog 1 (AKT1). Treatment of cells with SNP caused a rapid increase in NO levels in media. These increased NO levels were inhibited (P < 0.05) by 2-phenyl-4,4,5,5 tetramethylimidazoline-1-oxyl 3-oxide (PTIO), a NO scavenger. The SNP-induced cell proliferation and MAPK3/1 phosphorylation were attenuated (P < 0.05) by both PTIO and PD98059, a specific mitogen-activated protein kinase kinase 1 and 2 (MAP2K1/2, also termed MEK1/2) inhibitor. Using a semiquantitative RT-PCR analysis, we also showed that up to 12 h of treatment, SNP and N(G)-monomethyl-L-arginine (L-NMMA, a NOS inhibitor) did not alter mRNA expression of VEGF, FGF2, and their major receptors in OFPAE cells. The SNP's stimulatory effects on OFPAE cell proliferation and MAPK3/1 activation were confirmed in a human placental artery endothelial (HPAE) cell line. These data indicate that exogenous NO generated from SNP is able to stimulate fetoplacental artery endothelial cell proliferation at least partly via activation of the MAP2K1/2/MAPK3/1 cascade. These data also suggest that SNP could potentially be used to modulate placental angiogenesis.
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: Jason L
authors.initials: JL
authors.lastname: Austin
authors.forename: Dong-bao
authors.initials: DB
authors.lastname: Chen
mesh_terms: D000818:Animals; D001158:Arteries / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000187:drug effects / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; 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 / Q000187:drug effects / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism / Q000494:pharmacology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D021041:Placental Circulation; D011247:Pregnancy; D051057:Proto-Oncogene Proteins c-akt / Q000187:drug effects / Q000378:metabolism; D040262:Receptors, Vascular Endothelial Growth Factor / Q000187:drug effects / Q000235:genetics; D012756:Sheep; D042461:Vascular Endothelial Growth Factor A / Q000187:drug effects / Q000235:genetics
chemical_list: D020030:Nitric Oxide Donors; D042461:Vascular Endothelial Growth Factor A; D016222:Fibroblast Growth Factor 2; D009599:Nitroprusside; D009569:Nitric Oxide; D040262:Receptors, Vascular Endothelial Growth Factor; D051057:Proto-Oncogene Proteins c-akt; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3