Abstract: Objective To explore the expression of pyroptosis marker protein GSDMD-N and necroptosis marker protein p-MLKL in rheumatoid arthritis (RA) synovial tissues and potential significance. Methods The clinical data of the enrolled patients were recorded,including gender, age, erythrocyte sedimentation rate (ESR) and hypersensitive C-reactive protein (hsCRP). HE staining and microscopy were performed on RA and osteoarthritis (OA) synovium, Krenn score was used to evaluate the pathological synovitis. The synovial proteins of RA and OA were extracted.The expression of the related proteins of pyroptosis and necroptosis was detected by Western blot, and the correlation of GSDMD-N and p-MLKL with ESR, CRP and pathological synovitis were analyzed. Results Compared with OA,the expression level of GSDMD-N and p-MLKL in RA synovial tissues was significantly increased(P＜0.05), and was positively correlated with ESR and Krenn score(P＜0.05). GSDMD-N was also positively correlated with CRP level(P＜0.05). Conclusions Both pyroptosis and necroptosis in RA synovium show at positive correlation with disease activity and synovial inflammation, which might be involved in the process of RA synovitis and be potential targets for the treatment of RA.

Key words: rheumatoid arthritis, GSDMD-N, p-MLKL, pyroptosis, necroptosis