Osteoclast-Associated Receptor (OSCAR) Distribution in the Synovial Tissues of Patients with Active RA and TNF-α and RANKL Regulation of Expression by Osteoclasts In Vitro

Anak A.S.S.K. Dharmapatni, Kent Algate, Roxanne Coleman, Michelle Lorimer, Melissa Cantley, Malcolm D. Smith, Mihir D. Wechalekar, Tania N. Crotti

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Osteoclast-associated receptor (OSCAR) is a co-stimulatory receptor in osteoclastogenesis. Synovial tissues from active rheumatoid arthritis (RA) patients express higher levels of OSCAR compared with osteoarthritic and normal patients; however, the comparison of OSCAR levels in different regions of active RA synovium has not been reported. The regulation of OSCAR by TNF-α and receptor activator of NF kappa β ligand (RANKL) in pre-osteoclasts/osteoclasts in vitro is unclear. OSCAR and tartrate-resistant acid phosphatase (TRAP) expression levels did not differ between the cartilage pannus junction (CPJ) and non-CPJ regions in active RA. We demonstrate a similar pattern of OSCAR expression in the CPJ and non-CPJ synovial tissue from patients with active RA. OSCAR was associated with mononuclear cells in both the lining and sub-lining and endothelial cells (von Willebrand factor positive). Pre-osteoclasts (TRAP-positive cells) were present in the lining and sub-lining of both regions. OSCAR messenger RNA (mRNA) expression and release by pre-oscteoclasts/osteoclasts was modulated by RANKL with/without TNF-α in vitro. Osteoclast resorption on dentine slices was significantly greater with TNF-α pre-treatment and RANKL (10 ng/ml) than RANKL 10 or 50 ng/ml alone or RANKL 10 ng/ml with TNF-α given from day 3 post-RANKL. The lower levels of OSCAR mRNA expression corresponded with high osteoclast activity levels.

Original languageEnglish
Pages (from-to)1566-1575
Number of pages10
JournalInflammation
Volume40
Issue number5
DOIs
Publication statusPublished - 1 Oct 2017

Keywords

  • OSCAR
  • cartilage pannus junction
  • osteoclast
  • rheumatoid arthritis

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

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