Effects of 5-Aza-CdR on interleukin-1β, transforming growth factor -β and nitric oxide synthase expression in human chondrocyte

Abstract

Objective To investigate the effects of 5-Aza-CdR (methylation transferase inhibitor) on gene expression levels of interleukin-1β (IL-1β), transforming growth factor-β (TGF-β) and nitric oxide synthase (NOS) in chondrocytes. Methods Chondrocytes from patients with osteoarthritis (OA) (n=22), rheumatoid arthritis (RA) (n=3) or trauma without rheumatic diseases (n=10) were collected and cultured. The mRNA expression levels of IL-1β, TGF-β and NOS were detected by real-time polymerase chain reaction (RT-PCR). Chondrocytes in trauma group were treated with 5-Aza-CdR(10 μmol/L) for 72 h, and the mRNA and protein expression levels of IL-1β, TGF-β and NOS were detected by RT-PCR and ELISA, respectively. Results The mRNA expression levels of IL-1β, TGF-β and NOS were increased in OA and RA group as compared with trauma group (P<0.05), while they had no differences between OA and RA groups. After treated with 5-Aza-CdR, the mRNA and protein expression levels of IL-1β, TGF-β and NOS in chondrocytes rised in trauma group as compared with pretreatment (all P<0.05). Conclusions The mRNA expression levels of IL-1β, TGF-β and NOS in chondroytes are higher in OA and RA patients. 5-Aza-CdR could increase the mRNA and protein expression levels of IL-1β, TGF-β and NOS by inducing relative gene methylation, which suggests demethylation might play a role in OA pathogenesis by influncing the inflammatory signal pathway or cell apoptosis. Key words: Osteoarthris; Methylation; Chondrocytes