title: N-myc downstream-regulated gene 1 (NDRG1) mediates pomegranate juice protection from apoptosis in hypoxic BeWo cells but not in primary human trophoblasts.
abstract: BACKGROUND
  N-Myc downstream-regulated gene 1 (NDRG1) expression is increased in placentas of human pregnancies with intrauterine growth restriction and in hypoxic cultured primary trophoblasts. We previously showed that elevated NDRG1 decreases trophoblast apoptosis induced by hypoxia. Separately, we found that pomegranate juice (PJ) decreases cell death induced by hypoxia in trophoblasts. Here, we test the hypothesis that PJ protects trophoblasts from hypoxia-induced apoptosis by modulating NDRG1 expression.
  
  
  METHODS
  Quantitative rtPCR was used to investigate the effects of PJ treatment on mRNA levels of 22 candidate genes involved in apoptosis, oxidative stress, and differentiation in trophoblasts. Western blotting and immunofluorescence were used to analyze NDRG1 protein levels. siRNA-mediated NDRG1 knockdown was used to investigate the role of NDRG1 in response to PJ in hypoxic BeWo choriocarcinoma cells and hypoxic cultured primary human trophoblasts.
  
  
  RESULTS
  The mRNA levels of eight genes were altered, with NDRG1 showing the largest response to PJ and thus, we pursued the role of NDRG1 here. PJ significantly increased NDRG1 protein expression in primary trophoblasts and in BeWo cells. Knockdown of NDRG1 in hypoxic BeWo cells in the presence of PJ yielded increased apoptosis. In contrast, knockdown of NDRG1 in hypoxic primary trophoblasts in the presence of PJ did not increase apoptosis.
  
  
  CONCLUSIONS
  We conclude that the PJ-mediated decrease in cell death in hypoxia is partially mediated by NDRG1 in BeWo cells but not in primary trophoblasts. The disparate effects of NDRG1 between BeWo cells and primary trophoblasts indicate caution is required when extrapolating from results obtained with cell lines to primary trophoblasts.
authors.affiliation: Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, USA. Electronic address: chenb@wudosis.wustl.edu.
authors.forename: B
authors.initials: B
authors.lastname: Chen
authors.affiliation: Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: P G
authors.initials: PG
authors.lastname: Zaveri
authors.affiliation: Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Longtine
authors.affiliation: Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Nelson
mesh_terms: D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D018797:Cell Cycle Proteins / Q000378:metabolism*; D015687:Cell Hypoxia / Q000187:drug effects*; D002460:Cell Line; D005260:Female; D000067030:Fruit and Vegetable Juices; D006801:Humans; D000860:Hypoxia / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D029561:Lythraceae; D018384:Oxidative Stress; D011247:Pregnancy; D014327:Trophoblasts / Q000187:drug effects* / Q000378:metabolism; D000099259:N-myc Downstream-Regulated Gene 1 Protein
chemical_list: D018797:Cell Cycle Proteins; D047908:Intracellular Signaling Peptides and Proteins; D000099259:N-myc Downstream-Regulated Gene 1 Protein
keywords: Apoptosis; BeWo; Hypoxia; NDRG1; Placenta; Pomegranate juice; Trophoblast