title: Role of a fetal defence mechanism against oxidative stress in the aetiology of preeclampsia.
abstract: OBJECTIVE
  Increasing evidence suggests that oxidative stress may play a key role in the aetiology of preeclampsia (PE). The aim of this study was to elucidate the placental defence mechanisms employed against oxidative stress and, in particular, the specific role of nuclear factor erythroid 2-related factor 2 (Nrf2).
  
  
  RESULTS
  Expression of Nrf2 in third-trimester placental tissue was compared in preeclamptic and normal gestation-matched controls. PE was associated with increased Nrf2 activity within cytotrophoblastic nuclei. Nrf2 expression was restricted to proliferative and early post-proliferative cytotrophoblast only. Syncytiotrophoblast was immunonegative for Nrf2 in both controls and preeclamptic placentas.
  
  
  CONCLUSIONS
  Nrf2 is exclusively active within cytotrophoblast, strongly suggesting that these cells are the origin of Nrf2-dependent gene products. Syncytiotrophoblast is transcriptionally inactive; therefore in times of oxidative stress essential cytoprotective enzymes must be derived from the cytotrophoblast. Excessive cytotrophoblastic turnover causes disproportionate release of toxic placental factors, manifesting as PE and endangering maternal health. Increased cytotrophoblastic proliferation/fusion could thus be interpreted as a fetal defence mechanism, initiated in response to the requirements of vulnerable syncytiotrophoblast. We therefore propose a direct relationship between fetal defence against oxidative stress and consequent placental toxicity as part of the aetiology of this complex maternal disease.
authors.affiliation: Department of Anatomy and Cell Biology, RWTH Aachen University, Aachen, Germany. cwruck@ukaachen.de
authors.forename: Christoph Jan
authors.initials: CJ
authors.lastname: Wruck
authors.forename: Berthold
authors.initials: B
authors.lastname: Huppertz
authors.forename: Patrick
authors.initials: P
authors.lastname: Bose
authors.forename: Lars-Ove
authors.initials: LO
authors.lastname: Brandenburg
authors.forename: Thomas
authors.initials: T
authors.lastname: Pufe
authors.forename: Mamed
authors.initials: M
authors.lastname: Kadyrov
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D049109:Cell Proliferation; D003674:Defense Mechanisms; D005260:Female; D005333:Fetus / Q000378:metabolism / Q000503:physiopathology*; D006801:Humans; D051267:NF-E2-Related Factor 2 / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology*; D010920:Placenta / Q000378:metabolism; D011225:Pre-Eclampsia / Q000209:etiology* / Q000378:metabolism / Q000503:physiopathology*; D011247:Pregnancy; D011263:Pregnancy Trimester, Third / Q000502:physiology; D014327:Trophoblasts / Q000166:cytology / Q000378:metabolism
chemical_list: D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human