Epigenetic modifications of tumor necrosis factor-alpha in joint cartilage tissue from osteoarthritis patients - CONSORT

BACKGROUND: Osteoarthritis (OA) remains one of the most common osteopathy for centuries, which can be attributed to multiple risk factors including mechanical and biochemical ones. More and more studies verified that inflammatory cytokines play important roles in the progression of OA, such as tumor necrosis factor-alpha (TNF-α). In this study, we aimed to investigate the relationship between epigenetic manifestations of TNF-? and the pathogenesis of OA. METHODS: Totally, 37 OA patients’ cartilage was collected through the knee joint and 13 samples of articular cartilage as healthy control was collected through traumatic amputation. Real-time PCR, Western blot and ELISA analysis were performed to observe the expression of target genes and proteins in collected samples. RESULTS: Compared with the healthy control group, TNF-? was over-expressing in cartilage which was collected from OA patients. DNA hypomethylation, histone hyperacetylation and histone methylation were observed in the TNF-? promoter in OA compared with normal patients, and we also studied series of enzymes associated with epigenetics. The results showed that by increasing DNA methylation and decreasing histone acetylation in the TNF-? promoter, and TNF-? over-expression in OA cartilage was suppressed, histone methylation has no significant correlation with OA. CONCLUSION: In conclusion, the changes of epigenetic status regulate TNF-α expression in the cells, which are pivotal to the OA disease process. These results may give us a better understanding of OA and may provide new therapeutic options.