title: ENaC mediates human extravillous trophblast cell line (HTR8/SVneo) invasion by regulating levels of matrix metalloproteinase 2 (MMP2).
abstract: BACKGROUND
  Placenta dysfunction is thought to be the major etiological factor related to preeclampsia. The epithelial sodium channel (ENaC) has been localized in the apical plasma membrane of epithelia, mediating the active reabsorption of sodium in kidney, and be involved in the regulation of blood pressure. In previous studies, we found that the reduced expression of ENaC on placenta in preeclampsia patients. The aim of this study was to determine the role of MMP2 in the ENaC-induced trophoblast cell invasion ability, which is closely related to the occurrence of preeclampsia.
  
  
  METHODS
  Here we checked whether pregnancy related hormones human chorionic gonadotropin (HCG), prolactin and aldosterone could affect ENaC expression in the first trimester extravillous trophoblast cell line (HTR8/SVneo) by RT-PCR and Western blot. Cell invasion was studied by matrigel invasion assay. Tube formation assay was used to investigate the interaction between trophoblast cells and endothelial cells. The effects of ENaC on MMP2 were further determined by RT-PCR, western blot and gelatin zymography.
  
  
  RESULTS
  We demonstrated that HCG, prolactin and aldosterone could up-regulate the expression of αENaC in protein levels. Trophoblast cell invasion ability is stimulated when αENaC was up-regulated by aldosterone, and inhibited when ENaC was down-regulated by amiloride and αENaC specific RNAi (SiENA/ENaC). The interaction between HTR8/SVneo cells and HUVEC cells was enhanced when treated with aldosterone and weakened when treated with amiloride and SiRNA/ENaC. Amiloride and SiRNA/ENaC could inhibit MMP2 expression and activity.
  
  
  CONCLUSIONS
  Aldosterone induced ENaC activity is important for trophoblast cells invasion. The results also indicate that ENaC could mediate trophoblast cells invasion ability through regulating expression and activity of matrix metalloproteinase-2 (MMP2).
authors.affiliation: Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu 610041, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu 610041, China.
authors.forename: G
authors.initials: G
authors.lastname: He
authors.affiliation: Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu 610041, China; Joint Laboratory of Reproductive Medicine, Key Laboratory of BirthDefects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu 610041, China. Electronic address: Xuwenming1973@163.com.
authors.forename: W
authors.initials: W
authors.lastname: Xu
authors.affiliation: Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu 610041, China. Electronic address: xinghuiliu@163.com.
authors.forename: X
authors.initials: X
authors.lastname: Liu
mesh_terms: D000450:Aldosterone / Q000378:metabolism; D002460:Cell Line; D006063:Chorionic Gonadotropin / Q000378:metabolism; D053503:Epithelial Sodium Channels / Q000378:metabolism*; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism; D034741:RNA, Small Interfering; D014327:Trophoblasts / Q000502:physiology*
chemical_list: D006063:Chorionic Gonadotropin; D053503:Epithelial Sodium Channels; D034741:RNA, Small Interfering; D000450:Aldosterone; D011388:Prolactin; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2
keywords: ENaC; Invasion; MMP2; Preeclampsia; Trophoblast cells