title: Activation of PAR-1/NADPH oxidase/ROS signaling pathways is crucial for the thrombin-induced sFlt-1 production in extravillous trophoblasts: possible involvement in the pathogenesis of preeclampsia.
abstract: OBJECTIVE
  Preeclampsia was characterized by excessive thrombin generation in placentas and previous researches showed that thrombin could enhance soluble Fms-like tyrosine kinase 1 (sFlt-1) expression in first trimester trophoblasts. However, the detailed mechanism for the sFlt-1 over-production induced by thrombin was largely unknown. The purpose of this study was to explore the possible signaling pathway of thrombin-induced sFlt-1 production in extravillous trophoblasts (EVT).
  
  
  METHODS
  An EVT cell line (HRT-8/SVneo) was treated with various concentrations of thrombin. The mRNA expression and protein secretion of sFlt-1 in EVT were detected with real-time polymerase chain reaction and ELISA, respectively. The levels of intracellular reactive oxygen species (ROS) production were determined by DCFH-DA.
  
  
  RESULTS
  Exposure of EVT to thrombin induced increased intracellular ROS generation and overexpression of sFlt-1 at both mRNA and protein levels in a dose dependent manner. Short interfering RNA (siRNA) directed against PAR-1 or apocynin (an inhibitor of NADPH oxidase) could decrease the intracellular ROS generation and subsequently suppressed the production of sFlt-1 at mRNA and protein levels.
  
  
  CONCLUSIONS
  Our results suggested that thrombin increased sFlt-1 production in EVT via the PAR-1 /NADPH oxidase /ROS signaling pathway. This also highlights the PAR-1 / NADPH oxidase / ROS pathway might be a potential therapeutic target for the prevention of preeclampsia in the future.
authors.affiliation: Division of Obstetrics and Gynecology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Qi-Tao
authors.initials: QT
authors.lastname: Huang
authors.forename: Jian-Hong
authors.initials: JH
authors.lastname: Chen
authors.forename: Li-Lin
authors.initials: LL
authors.lastname: Hang
authors.forename: Shi-San
authors.initials: SS
authors.lastname: Liu
authors.forename: Mei
authors.initials: M
authors.lastname: Zhong
mesh_terms: D000098:Acetophenones / Q000494:pharmacology; D002460:Cell Line; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011225:Pre-Eclampsia / Q000378:metabolism / Q000473:pathology; D011247:Pregnancy; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D044463:Receptor, PAR-1 / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D013917:Thrombin / Q000494:pharmacology*; D014327:Trophoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000235:genetics / Q000378:metabolism*; D010975:Platelet Aggregation Inhibitors
chemical_list: D000098:Acetophenones; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D044463:Receptor, PAR-1; C056165:acetovanillone; D019255:NADPH Oxidases; C501162:FLT1 protein, human; D040281:Vascular Endothelial Growth Factor Receptor-1; D013917:Thrombin; D010975:Platelet Aggregation Inhibitors