Genomewide comprehensive analysis reveals critical cooperation between Smad and c-Fos in RANKL-induced osteoclastogenesis

J Bone Miner Res. 2015 May;30(5):869-77. doi: 10.1002/jbmr.2418.

Abstract

We have previously reported that transforming growth factor β (TGF-β) plays an essential role in receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis. However, the detailed underlying molecular mechanisms still remain unclear. Formaldehyde-assisted isolation of regulatory elements (FAIRE) and chromatin immunoprecipitation (ChIP) followed by sequencing (FAIRE-seq and ChIP-seq) analyses indicated the cooperation of Smad2/3 with c-Fos during osteoclastogenesis. Biochemical analysis and immunocytochemical analysis revealed that physical interaction between Smad2/3 and c-Fos is required for their nuclear translocation. The gene expression of nuclear factor of activated T-cells, cytoplasmic 1 (Nfatc1), a key regulator of osteoclastogenesis, was regulated by RANKL and TGF-β, and c-Fos binding to open chromatin sites was suppressed by inhibition of TGF-β signaling by SB431542. Conversely, Smad2/3 binding to Nfatc1 was impaired by c-Fos deficiency. These results suggest that TGF-β regulates RANKL-induced osteoclastogenesis through reciprocal cooperation between Smad2/3 and c-Fos.

Keywords: CELL/TISSUE SIGNALING; CYTOKINES; MOLECULAR PATHWAYS; OSTEOCLAST; TRANSCRIPTION FACTORS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chromatin / metabolism
  • Genome*
  • Humans
  • Male
  • Mice
  • NFATC Transcription Factors / genetics
  • NFATC Transcription Factors / metabolism
  • Osteoclasts / cytology*
  • Osteoclasts / drug effects
  • Osteoclasts / metabolism
  • Osteogenesis / drug effects*
  • Protein Binding / drug effects
  • Proto-Oncogene Proteins c-fos / metabolism*
  • RANK Ligand / pharmacology*
  • Smad Proteins / metabolism*
  • Transforming Growth Factor beta

Substances

  • Chromatin
  • NFATC Transcription Factors
  • Nfatc1 protein, mouse
  • Proto-Oncogene Proteins c-fos
  • RANK Ligand
  • Smad Proteins
  • Transforming Growth Factor beta