Exported 18-kDa isoform of fibroblast growth factor-2 is a critical determinant of bone mass in mice

Liping Xiao, Peng Liu, Xiaofeng Li, Thomas C Doetschman, J. Douglas Coffin, Hicham Drissi, Marja M. Hurley

Research output: Contribution to journalArticle

42 Scopus citations

Abstract

The role of the 18-kDa isoform of fibroblast growth factor-2 (FGF2) in the maintenance of bone mass was examined in Col3.6-18-kDa FGF2-IRES-GFPsaph transgenic (18-kDa TgFGF2) mice in which a 3.6-kb fragment of the type I collagen 5′-regulatory region (Col3.6) drives the expression of only the 18-kDa isoform of FGF2 with green fluorescent protein-sapphire (GFPsaph). Vector only transgenic mice (Col3.6-IRESGFPsaph, VTg) were also developed as a control, and mice specifically deficient in 18-kDa FGF2 (FGF2lmw-/-) were also examined. Bone mineral density, femoral bone volume, trabecular thickness, and cortical bone area and thickness were significantly increased in 18-kDa TgFGF2 mice compared with VTg. Bone marrow cultures (BMSC) from 18-kDa TgFGF2 mice produced more mineralized nodules than VTg. Increased bone formation was associated with reduced expression of the Wnt antagonist secreted frizzled receptor 1 (sFRP-1). In contrast to 18-kDa TgFGF2 mice, FGF2lmw-/- mice have significantly reduced bone mineral density and fewer mineralized nodules, coincident with increased expression of sFRP-1 in bones and BMSC. Moreover, silencing of sFRP-1 in BMSC from FGF2lmw-/- mice reversed the decrease in β-catenin and Runx2 mRNA. Assay of Wnt/β-catenin- mediated transcription showed increased and decreased TCF-luciferase activity in BMSC from 18-kDa TgFGF2 and FGF2lmw-/- mice, respectively. Collectively, these results demonstrate that the 18-kDa FGF2 isoform is a critical determinant of bone mass in mice by modulation of the Wnt signaling pathway.

Original languageEnglish (US)
Pages (from-to)3170-3182
Number of pages13
JournalJournal of Biological Chemistry
Volume284
Issue number5
DOIs
Publication statusPublished - Jan 30 2009

    Fingerprint

ASJC Scopus subject areas

  • Biochemistry
  • Cell Biology
  • Molecular Biology

Cite this