title: Glyceryl trinitrate inhibits hypoxia-induced release of soluble fms-like tyrosine kinase-1 and endoglin from placental tissues.
abstract: Preeclampsia is associated with increased circulating levels of proinflammatory molecules, such as soluble fms-like tyrosine kinase 1 (sFlt-1) and soluble endoglin (sEng). On release by an inadequately perfused placenta into the maternal circulation, these molecules cause systemic endothelial dysfunction and the associated hypertension and proteinuria that characterize preeclampsia. We previously showed that glyceryl trinitrate (GTN) inhibits hypoxia/reoxygenation-induced apoptosis in the syncytiotrophoblast of term chorionic villi explants. Herein, we demonstrate that GTN inhibits the release of sFlt-1 and sEng from term chorionic villi explants exposed to hypoxia. Although transcript levels and secretion of sFlt-1 and sEng increased in explants exposed to hypoxia, low concentrations of GTN significantly inhibited the hypoxia-induced expression of these molecules at the mRNA and protein levels. Treatment of explants with GTN also prevented the hypoxia-induced accumulation of hypoxia-inducible factor-1α, a key mediator of cellular adaptations to hypoxia. Furthermore, knockdown of hypoxia-inducible factor-1α inhibited the hypoxia-induced secretion of sFlt-1 and sEng. This study provides evidence that hypoxia induces the release of sFlt-1 and sEng in the placenta via a mechanism that is inhibited by low concentrations of GTN. Our findings indicate that GTN may have potential applications in the treatment and/or prevention of preeclampsia.
authors.affiliation: Department of Anatomy and Cell Biology, Queen's University, Kingston, Ontario, Canada.
authors.forename: Ivraym B
authors.initials: IB
authors.lastname: Barsoum
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Renaud
authors.forename: Charles H
authors.initials: CH
authors.lastname: Graham
mesh_terms: D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism*; D002824:Chorionic Villi / Q000187:drug effects / Q000378:metabolism; D000071063:Endoglin; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D055785:Gene Knockdown Techniques; D006801:Humans; D000860:Hypoxia / Q000473:pathology*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000172:deficiency; D005996:Nitroglycerin / Q000494:pharmacology*; D010920:Placenta / Q000187:drug effects* / Q000378:metabolism*; D011247:Pregnancy; D021381:Protein Transport / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000235:genetics / Q000378:metabolism*
chemical_list: D015703:Antigens, CD; C064206:ENG protein, human; D000071063:Endoglin; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; C501162:FLT1 protein, human; D040281:Vascular Endothelial Growth Factor Receptor-1; D005996:Nitroglycerin