A novel Mtd splice isoform is responsible for trophoblast cell death in pre-eclampsia

Cell Death Differ. 2005 May;12(5):441-52. doi: 10.1038/sj.cdd.4401593.

Abstract

Pre-eclampsia is a serious disorder of human pregnancy, characterized by decreased utero-placental perfusion and increased trophoblast cell death. Presently, the mechanisms regulating trophoblast cell death in pre-eclampsia are not fully elucidated. Herein, we have identified a novel Mtd/Bok splice isoform (Mtd-P) resulting from exon-II skipping. Mtd-P expression was unique to early-onset severe pre-eclamptic placentae as assessed by quantitative real-time-PCR and immunoblotting. Mtd-P overexpression in cell lines (BeWo: cytotrophoblast-derived; and CHO: ovary-derived) resulted in increased apoptotic cell death as assessed by caspase-3 cleavage, internucleosomal DNA laddering and mitochondrial depolarization. Moreover, Mtd-P expression increased under conditions of low oxygenation/oxidative stress in human villous explants. Antisense knockdown of Mtd under conditions of oxidative stress resulted in decreased caspase-3 cleavage. We conclude that under conditions of reduced oxygenation/oxidative stress, Mtd-P causes trophoblast cell death in pre-eclampsia and hence may contribute to the molecular events leading to the clinical manifestations of this disease.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alternative Splicing*
  • Amino Acid Sequence
  • Cell Death*
  • Female
  • Humans
  • Membrane Potentials
  • Mitochondria / physiology
  • Models, Biological
  • Molecular Sequence Data
  • Oxidative Stress
  • Placenta / cytology
  • Pre-Eclampsia / metabolism
  • Pre-Eclampsia / pathology*
  • Pregnancy
  • Pregnancy Trimester, First
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • Proto-Oncogene Proteins c-bcl-2
  • Trophoblasts / pathology*

Substances

  • BOK protein, human
  • Protein Isoforms
  • Proto-Oncogene Proteins c-bcl-2