Genetic modifications of Mecr reveal a role for mitochondrial 2-enoyl-CoA/ACP reductase in placental development in mice

Hum Mol Genet. 2017 Jun 1;26(11):2104-2117. doi: 10.1093/hmg/ddx105.

Abstract

Mitochondrial fatty acid synthesis (mtFAS) is an underappreciated but highly conserved metabolic process, indispensable for mitochondrial respiration. It was recently reported that dysfunction of mtFAS causes childhood onset of dystonia and optic atrophy in humans (MEPAN). To study the role of mtFAS in mammals, we generated three different mouse lines with modifications of the Mecr gene, encoding mitochondrial enoyl-CoA/ACP reductase (Mecr). A knock-out-first type mutation, relying on insertion of a strong transcriptional terminator between the first two exons of Mecr, displayed embryonic lethality over a broad window of time and due to a variety of causes. Complete removal of exon 2 or replacing endogenous Mecr by its functional prokaryotic analogue fabI (Mecrtm(fabI)) led to more consistent lethality phenotypes and revealed a hypoplastic placenta. Analyses of several mitochondrial parameters indicate that mitochondrial capacity for aerobic metabolism is reduced upon disrupting mtFAS function. Further analysis of the synthetic Mecrtm(fabI) models disclosed defects in development of placental trophoblasts consistent with disturbed peroxisome proliferator-activated receptor signalling. We conclude that disrupted mtFAS leads to deficiency in mitochondrial respiration, which lies at the root of the observed pantropic effects on embryonic and placental development in these mouse models.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Enoyl-(Acyl-Carrier-Protein) Reductase (NADH) / genetics*
  • Enoyl-(Acyl-Carrier-Protein) Reductase (NADH) / metabolism*
  • Fatty Acid Desaturases / metabolism
  • Fatty Acids / metabolism
  • Female
  • Mice
  • Mice, Knockout
  • Mitochondria / metabolism
  • Oxidoreductases / metabolism
  • Oxidoreductases Acting on CH-CH Group Donors / genetics*
  • Oxidoreductases Acting on CH-CH Group Donors / metabolism*
  • Placenta
  • Placentation / genetics
  • Placentation / physiology
  • Pregnancy

Substances

  • Fatty Acids
  • Oxidoreductases
  • Fatty Acid Desaturases
  • Oxidoreductases Acting on CH-CH Group Donors
  • trans-2-enoyl-CoA reductase (NADPH)
  • Enoyl-(Acyl-Carrier-Protein) Reductase (NADH)