Abstract:Objective To investigate the role of necroptosis in endometriosis and the mechanism of interaction of high mobility group box-1 (HMGB1) protein and receptor interacting protein 3 (RIP3). Methods A total of 64 patients who underwent hysterectomy at the Affiliated Hospital of Xuzhou Medical University from April 2018 to April 2019 were enrolled.Forty-three patients with EMT diagnosed by gynecological laparoscopic surgery and postoperative pathology were divided into observation group 1 (stage Ⅰ,Ⅱ,22 cases) and observation group 2 (stage Ⅲ,Ⅳ,21 cases);5 cases of non-EMT endometrial proliferation in the late stage of menstrual cycle were taken as the normal group,and 16 in the late secretory stage of menstrual cycle were the necrosis group.Immunofluorescence staining and Western blot were used to detect the expression levels of programmed cell necrosis-related protein——RIP3 and phosphorylated mixed lineage kinase-domain like protein (p-MLKL) in endometrial tissue of the four groups.The serum HMGB1 content was detected by ELISA.Western blot was used to detect the expression levels of HMGB1;co-immunoprecipitation method was used to verify the mutual binding of RIP3 protein and HMGB1 protein. Results The relative expression level of p-MLKL and RIP3 protein in the endometrial tissues of observation group 1 and 2 were significantly lower than those in necrosis group (P<0.05,P<0.01).The level of HMGB1 in the cytoplasm of the observation group 1,2 and the necrotic group were significantly increased compared with the normal group (P<0.05,P<0.01).The level of HMGB1 in the serum of observation group 1 and 2 were significantly increased compared with the normal group (P<0.05,P<0.01),but the level of HMGB1 in the serum of the necrotic group did not increase significantly.Compared with the normal group,the binding level of RIP3 and HMGB1 was significantly increased in the necrotic group,while the binding degree of RIP3 and HMGB1 was lower in the observation group 2. Conclusions The level of programmed cell necrosis related proteins in the endometrium of EMT patients are decreased,and the increased release of extracellular HMGB1 is related to the decrease of the binding level of RIP3-HMGB1.The interaction between RIP3 and HMGB1 may be involved in the negative regulation of EMT.