Redox-Sensitive Transcription Factor NRF2 Enhances Trophoblast Differentiation via Induction of miR-1246 and Aromatase

Endocrinology. 2018 May 1;159(5):2022-2033. doi: 10.1210/en.2017-03024.

Abstract

Dysregulation of human trophoblast invasion and differentiation with placental hypoxia can result in preeclampsia, a hypertensive disorder of pregnancy. Herein, we characterized the role and regulation of miR-1246, which is markedly induced during human syncytiotrophoblast differentiation. miR-1246 targets GSK3β and AXIN2, inhibitors of WNT/β-catenin signaling, which is crucial for placental development, and is predicted to target JARID2, which promotes silencing of developmentally regulated genes. Human cytotrophoblasts cultured in 20% O2 spontaneously differentiate to syncytiotrophoblast with induction of hCYP191A/aromatase, a marker of differentiation. miR-1246 was induced >150-fold during syncytiotrophoblast differentiation in 20% O2, whereas targets-GSK3β, AXIN2, and JARID2-were significantly decreased. However, when cytotrophoblasts were cultured in 2% O2, miR-1246 and aromatase induction were prevented. miR-1246 was significantly decreased in placentas of women with severe preeclampsia, whereas AXIN2, GSK3β, and JARID2 were increased, compared with normotensive subjects. To identify factors that regulate miR-1246, we investigated the redox-regulated transcription factor NRF2, which has predicted binding sites in the miR-1246 promoter. Intriguingly, NRF2 messenger RNA was upregulated during syncytiotrophoblast differentiation and significantly reduced by hypoxia and in preeclamptic placentas. Moreover, NRF2 knockdown in cytotrophoblasts inhibited induction of miR-1246 and hCYP19A1, as well as transcription factors C/EBPβ and PPARγ, which are implicated in placental differentiation. Using chromatin immunoprecipitation-quantitative polymerase chain reaction, we found that binding of endogenous NRF2 to the miR-1246 and hCYP191A promoters increased during syncytiotrophoblast differentiation. Thus, NRF2 promotes syncytiotrophoblast differentiation by inducing C/EBPβ, PPARγ, hCYP19A1, and miR-1246, which targets WNT inhibitors and JARID2 and is dysregulated in preeclampsia.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aromatase / genetics
  • Axin Protein / metabolism
  • CCAAT-Enhancer-Binding Protein-beta / metabolism
  • Cell Differentiation / genetics*
  • Chromatin Immunoprecipitation
  • Female
  • Gene Knockdown Techniques
  • Glycogen Synthase Kinase 3 beta / metabolism
  • Humans
  • Hypoxia / genetics
  • Hypoxia / metabolism
  • MicroRNAs / genetics*
  • NF-E2-Related Factor 2 / metabolism*
  • Oxidation-Reduction
  • PPAR gamma / metabolism
  • Placenta / cytology
  • Placenta / metabolism*
  • Polycomb Repressive Complex 2 / metabolism
  • Polymerase Chain Reaction
  • Pre-Eclampsia / genetics*
  • Pregnancy
  • Trophoblasts / cytology
  • Trophoblasts / metabolism*
  • Wnt Signaling Pathway

Substances

  • AXIN2 protein, human
  • Axin Protein
  • CCAAT-Enhancer-Binding Protein-beta
  • CEBPB protein, human
  • JARID2 protein, human
  • MIRN1246 microRNA, human
  • MicroRNAs
  • NF-E2-Related Factor 2
  • NFE2L2 protein, human
  • PPAR gamma
  • Aromatase
  • CYP19A1 protein, human
  • Polycomb Repressive Complex 2
  • GSK3B protein, human
  • Glycogen Synthase Kinase 3 beta