Repression of osteoblast maturation by ERRα accounts for bone loss induced by estrogen deficiency

PLoS One. 2013;8(1):e54837. doi: 10.1371/journal.pone.0054837. Epub 2013 Jan 24.

Abstract

ERRα is an orphan member of the nuclear receptor family, the complete inactivation of which confers resistance to bone loss induced by ageing and estrogen withdrawal to female mice in correlation with increased bone formation in vivo. Furthermore ERRα negatively regulates the commitment of mesenchymal cells to the osteoblast lineage ex vivo as well as later steps of osteoblast maturation. We searched to determine whether the activities of ERRα on osteoblast maturation are responsible for one or both types of in vivo induced bone loss. To this end we have generated conditional knock out mice in which the receptor is normally present during early osteoblast differentiation but inactivated upon osteoblast maturation. Bone ageing in these animals was similar to that observed for control animals. In contrast conditional ERRαKO mice were completely resistant to bone loss induced by ovariectomy. We conclude that the late (maturation), but not early (commitment), negative effects of ERRα on the osteoblast lineage contribute to the reduced bone mineral density observed upon estrogen deficiency.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Lineage
  • Estrogen Receptor alpha / genetics
  • Estrogen Receptor alpha / physiology*
  • Estrogens / deficiency*
  • Male
  • Mice
  • Mice, Knockout
  • Mice, Transgenic
  • Osteoblasts / cytology*
  • Osteoporosis / pathology
  • Osteoporosis / physiopathology*
  • Rabbits

Substances

  • Estrogen Receptor alpha
  • Estrogens

Grant support

This work was supported by Agence Nationale de la Recherche (grant ANR-GENOPAT-012), Ligue contre le Cancer (comité Rhône) and Association pour la Recherche sur le Cancer. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.