Expression of PRDM10 in arthritic synovial derived tissues

Abstract

We previously reported the expression of PRDM10 in skeletal cartilage during mouse embryonic development. In this study, we examined PRDM10 expression in blood, synovial fluid and synovium from patients with rheumatoid arthritis (RA) or osteoarthritis (OA). PRDM10 mRNA was detected in all peripheral blood and RA synovial fluid, as well as in normal blood. We also performed immunohistochemistry with human synovium tissues. Compared to other PR/SET proteins including PRDM14, PRDM12, and SUV39H1, PRDM10 expression was conspicuous in cells of the synovial lining layer, subintimal layer, and perivascular layer in RA and OA synovium. Immunostaining using cultured fibroblast like synoviocytes detected PRDM10 mainly in the nucleus, with a small amount detected in the cytoplasm. Transforming growth factor-beta (TGF-beta) treatment decreased PRDM10 expression in OA-derived FLS cells, whereas polyinosinic:polycytidylic acid or lipopolysaccharide treatment did not produce a distinct change of PRDM10 expression, PRDM10 expression was reversed by the smad inhibitor SB431542. Given that PRDM10 is highly expressed in human synovial tissues and is transcriptionally regulated by TGF-beta, we suggest that PRDM10 might be involved in the pathogenesis of arthritis.