siRNA沉默锌指蛋白A20基因促进人类风湿关节炎成纤维细胞样滑膜细胞焦亡

Zinc finger protein A20-targeting siRNA promotes pyroptosis of human rheumatoid arthritis fibroblast-like synoviocytes

目的探讨小干扰RNA(siRNA)沉默锌指蛋白A20基因对人类风湿关节炎(RA)成纤维细胞样滑膜细胞(HFLS-RA)焦亡的调节作用。方法培养人HFLS-RA细胞系(MH7A细胞),通过RNA干扰技术靶向敲降人类A20基因,合成siRNA-A20,用脂质体法将siRNA-A20(沉默组)和siRNA-NC(阴性对照组)转染MH7A细胞。RT-qPCR检测细胞中NLRP3和Caspase-1 mRNA的表达;Western blot法检测细胞中NLRP3和Caspase-1蛋白表达;ELISA法检测细胞培养液中IL-1β和IL-18的水平;透射电子显微镜(TEM)检测细胞焦亡。结果siRNA-A20组MH7A细胞中NLRP3和Caspase-1 mRNA和蛋白表达水平与对照组相比均显著增高(P<0.01);siRNA-A20组细胞培养上清液中IL-1β、IL-18浓度与对照组相比均显著增高(P<0.01)。与对照组相比,siRNA-A20组部分细胞肿胀和破裂,细胞膜的完整性也丧失,细胞内出现大面积水肿区,细胞核局部核膜凹陷模糊,异染色质固缩增加,分布不均匀并在核膜周围聚集。结论通过siRNA沉默A20表达后可促进HFLS-RA中NLRP3/Caspase-1介导细胞焦亡,为探讨RA临床治疗新方案提供了实验依据。

Objective To investigate the regulatory effect of small interfering RNA(siRNA)silencing zinc finger protein A20 on pyroptosis of rheumatoid arthritis(RA)fibroblast-like synoviocytes(HFLS-RA).Methods Human FLS-RA cell line MH7A cells were cultivated,A20 siRNA silencing group was synthesized for knocking down the human A20 gene,and then specific A20 gene siRNA and siRNA-NC(negative control)were transfected into MH7A cells using liposome method.RT-qPCR was applied to detect the expression of NLRP3 and Caspase-1 mRNA in cells.The protein expression of NLRP3 and Caspase-1 was detected by Western blot,and IL-1βand IL-18 in cell culture medium were detected by ELISA method.Transmission electron microscopy(TEM)was used to detect pyroptosis.Results After A20 knockdown,the mRNA and expression of NLRP3 and Caspase-1 in MH7A cells in the siRNA-A20 group were significantly increased as compared with the siRNA-NC group(P<0.01).The concentration of IL-1βand IL-18 in the cell culture supernatant of the siRNA-A20 group was significantly increased compared with the siRNA-NC group(P<0.01).Compared with the siRNA-NC group,some cells in the siRNA-A20 group showed swollen and ruptured.The integrity of the cell membrane was also lost,and a large area of edema was present in the cell.In addition,a blurred depression of the local nuclear membrane was noted,while an increase in heterochromatin pyknosis was accompanied by their uneven distribution as well as their aggregation around the nuclear membrane.Conclusions Silencing of A20 gene with siRNA might promote NLRP3/Caspase-1 mediated pyroptosis in HFLS-RA,which lays an experimental foundation for new clinical treatment methods of RA.