Wnt/beta-catenin signaling is a component of osteoblastic bone cell early responses to load-bearing and requires estrogen receptor alpha

Victoria J Armstrong, Mariusz Muzylak, Andrew Sunters, Gul Zaman, Leanne K Saxon, Joanna S Price, Lance E Lanyon

Research output: Contribution to journalArticle (Academic Journal)

216 Citations (Scopus)

Abstract

The Wnt/beta-catenin pathway has been implicated in bone cell response to their mechanical environment. This response is the origin of the mechanism by which bone cells adjust bone architecture to maintain bone strength. Osteoporosis is the most widespread failure of this mechanism. The degree of osteoporotic bone loss in men and women is related to bio-available estrogen. Here we report that in osteoblastic ROS 17/2.8 cells and primary osteoblast cultures, a single short period of dynamic mechanical strain, as well as the glycogen synthase kinase-3beta (GSK-3beta) inhibitor LiCl, increased nuclear accumulation of activated beta-catenin and stimulated TCF/LEF reporter activity. This effect was blocked by the estrogen receptor (ER) modulators ICI 182,780 and tamoxifen and was absent in primary osteoblast cultures from mice lacking ERalpha. Microarray expression data for 25,000 genes from total RNA extracted from tibiae of wild-type mice within 24 h of being loaded in vivo showed differential gene regulation between loaded and contralateral non-loaded bones of 10 genes established to be involved in the Wnt pathway. Only 2 genes were involved in loaded tibiae from mice lacking ERalpha (ERalpha(-/-)). Together these data suggest that Wnt/beta-catenin signaling contributes to bone cell early responses to mechanical strain and that its effectiveness requires ERalpha. Reduced effectiveness of bone cell responses to bone loading, associated with estrogen-related decline in ERalpha, may contribute to the failure to maintain structurally appropriate bone mass in osteoporosis in both men and women.
Original languageEnglish
Pages (from-to)20715-27
Number of pages13
JournalJournal of Biological Chemistry
Volume282
Issue number28
DOIs
Publication statusPublished - 13 Jul 2007

Keywords

  • Animals
  • Cell Line
  • Female
  • Gene Expression Profiling
  • Gene Expression Regulation
  • Humans
  • Male
  • Mice
  • Mice, Knockout
  • Oligonucleotide Array Sequence Analysis
  • Osteoblasts
  • Osteoporosis
  • Receptors, Estrogen
  • Signal Transduction
  • Tibia
  • Weight-Bearing
  • Wnt Proteins
  • beta Catenin

Fingerprint Dive into the research topics of 'Wnt/beta-catenin signaling is a component of osteoblastic bone cell early responses to load-bearing and requires estrogen receptor alpha'. Together they form a unique fingerprint.

  • Cite this