Fas/S1P1 crosstalk via NF-κB activation in osteoclasts controls subchondral bone remodeling in murine TMJ arthritis

Islamy Rahma Hutami, Takashi Izawa, Akiko Mino-Oka, Takehiro Shinohara, Hiroki Mori, Akihiko Iwasa, Eiji Tanaka

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Enhanced turnover of subchondral trabecular bone is a hallmark of rheumatoid arthritis (RA) and it results from an imbalance between bone resorption and bone formation activities. To investigate the formation and activation of osteoclasts which mediate bone resorption, a Fas-deficient MRL/lpr mouse model which spontaneously develops autoimmune arthritis and exhibits decreased bone mass was studied. Various assays were performed on subchondral trabecular bone of the temporomandibular joint (TMJ) from MRL/lpr mice and MRL+/+ mice. Initially, greater osteoclast production was observed in vitro from bone marrow macrophages obtained from MRL/lpr mice due to enhanced phosphorylation of NF-κB, as well as Akt and MAPK, to receptor activator of nuclear factor-κB ligand (RANKL). Expression of sphingosine 1-phosphate receptor 1 (S1P1) was also significantly upregulated in the condylar cartilage. S1P1 was found to be required for S1P-induced migration of osteoclast precursor cells and downstream signaling via Rac1. When SN50, a synthetic NF-κB-inhibitory peptide, was applied to the MRL/lpr mice, subchondral trabecular bone loss was reduced and both production of osteoclastogenesis markers and sphingosine kinase (Sphk) 1/S1P1 signaling were reduced. Thus, the present results suggest that Fas/S1P1 signaling via activation of NF-κB in osteoclast precursor cells is a key factor in the pathogenesis of RA in the TMJ.

Original languageEnglish
Pages (from-to)1274-1281
Number of pages8
JournalBiochemical and Biophysical Research Communications
Volume490
Issue number4
DOIs
Publication statusPublished - Sep 2 2017
Externally publishedYes

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Keywords

  • Fas
  • Osteoclast
  • S1P
  • SN50
  • Temporomandibular joint

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

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