title: Toll-like receptor-3 stimulation upregulates sFLT-1 production by trophoblast cells.
abstract: BACKGROUND
  Preeclampsia is characterized by a systemic inflammatory response involving cytokines, chemokines, and anti-angiogenic factors such as sFLT-1. In many other inflammatory diseases related responses are triggered by toll-like receptor (TLR) stimulation. Therefore, we tested the hypothesis that TLR stimulation of a trophoblast cell line induces inflammatory mediator production and, in particular, production of the preeclampsia-related anti-angiogenic factor sFLT-1.
  
  
  METHODS
  We stimulated human first trimester extravillous trophoblast cells (HTR-8/SV neo cell line) with a variety of TLR ligands and measured downstream NF-kappaB and IRF signaling, inflammatory mediator (RANTES), and sFLT-1 mRNA expression and protein production.
  
  
  RESULTS
  Of all TLR ligands, we found that TLR3 ligation with polyI:C resulted in the biggest response with 5.6-fold increased signaling via NF-kappaB and 5.8-fold increased signaling via IRF. RANTES mRNA expression increased 2900 fold and protein production increased 1600 fold in response to TLR3 ligation. sFLT-1 mRNA expression increased 1.7-fold and protein production increased 3.1-fold in response to TLR3 ligation. Inhibitors of the NF-kappaB and IRF signaling pathway decreased TLR3 ligation-induced sFLT-1 protein production by 31.8% and 24.9%, respectively.
  
  
  CONCLUSIONS
  We conclude that trophoblast cells respond to TLR3 ligation by signaling through both NF-kappaB and IRF pathways resulting in expression of inflammatory mediators and, in particular, the preeclampsia-related anti-angiogenic factor sFLT-1.
authors.affiliation: Critical Care Research Laboratories, Heart+Lung Institute, University of British Columbia, Vancouver V6Z 1Y6, Canada.
authors.forename: E
authors.initials: E
authors.lastname: Nakada
authors.forename: K R
authors.initials: KR
authors.lastname: Walley
authors.forename: T
authors.initials: T
authors.lastname: Nakada
authors.forename: Y
authors.initials: Y
authors.lastname: Hu
authors.forename: P
authors.initials: P
authors.lastname: von Dadelszen
authors.forename: J H
authors.initials: JH
authors.lastname: Boyd
mesh_terms: D000704:Analysis of Variance; D002460:Cell Line; D018946:Chemokine CCL5 / Q000235:genetics / Q000378:metabolism; D017077:Culture Media, Conditioned / Q000737:chemistry; D042783:Endothelial Cells / Q000378:metabolism; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D050835:Interferon Regulatory Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008024:Ligands; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D011225:Pre-Eclampsia / Q000378:metabolism; D011247:Pregnancy; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D051196:Toll-Like Receptor 3 / Q000378:metabolism*; D051193:Toll-Like Receptors / Q000378:metabolism; D014162:Transfection; D014327:Trophoblasts / Q000378:metabolism*; D015854:Up-Regulation; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D018946:Chemokine CCL5; D017077:Culture Media, Conditioned; D018836:Inflammation Mediators; D050835:Interferon Regulatory Factors; D015850:Interleukin-6; D008024:Ligands; D016328:NF-kappa B; D012333:RNA, Messenger; D051196:Toll-Like Receptor 3; D051193:Toll-Like Receptors; C501162:FLT1 protein, human; D040281:Vascular Endothelial Growth Factor Receptor-1