中文摘要：

目的 研究小干扰RNA（siRNA）沉默肽酰基精氨酸脱亚胺酶4（PADI4）基因在滑膜成纤维细胞（FLS）凋亡调控中的作用,为进一步研究PADI4在RA发病机制中的作用奠定基础.方法 设计并合成2对针对PADI4基因编码区的干扰核苷酸链,通过脂质体介导将siRNA转入RA-FLS细胞中,作用48 h后收集FLS细胞,抽提RNA逆转为cDNA,并提取FLS细胞蛋白质,通过荧光定量PCR、蛋白印迹技术,确定siRNA成功干扰PADI4表达后,比较siRNA实验组FLS细胞和对照组FLS细胞凋亡率,细胞周期调控蛋白CyclinB1和P21的表达量.收集细胞培养液,ELISA法测定IL-1β.所有数据采用配对t检验进行分析.结果 所设计的针对PADI4的siRNA成功干扰PADI4在FLS中的表达,空白对照组（si-NC）中PADI4 mRNA水平为1.00±0.20,si-944和si-1225干扰组分别为0.38±0.20（t=9.607,P＜0.01）和0.39±0.23 （t=8.394,P＜0.01）;FLS中与对照组细胞凋亡率（1.6±0.3）％相比,si-944和si-1225干扰组分别为（5.4±0.6）％（t=-19.223,P＜0.01）,（6.1±0.6）％（t=-24.229,P＜0.01）,细胞凋亡明显增加.siRNA转染组细胞周期蛋白CyclinB1表达下降,P21表达上升.与对照组IL-1β水平（23.9±0.7） ng/ml相比较,si-944和si-1225干扰组IL-1β分泌增多[分别为（26.8±0.7） ng/ml,（27.7±0.7） ng/ml;t=-10.747,-10.967,P均＜0.01）.结论 PADI4在FLS细胞凋亡中起着重要的调控作用,可能在RA的发病中起着一定的作用.

英文摘要：

Objective To evaluate the effects of small interfering RNA （siRNA） against peptidylarginine deiminase 4 （PADI4） gene on apoptosis of fibroblast-like synoviocytes （FLS） from synovium of rheumatoid arthritis （RA）.Methods The siRNA targeting PADI4 was constructed and transfected into FLS cells in RA via LipofectamineTM 2000.The expression level of PDAI4 mRNA was detected by using real-time quantitative polymerase chain reaction （real-time PCR）.The protein expression of PADI4,CyclinB1 and P21 was detected by Western blotting.The apoptosis of FLS cells in RA was examined by flow cytometry.The levels of IL-1β were detected by ELISA.T-test was used for statistical analysis.Results siRNA-PADI4 efficiently down-regulated the PADI4 expression compared with control group,1.00±0.20 vs 0.38±0.20 （t=9.607,P〈0.01）,0.39±0.23（t=8.394,P〈0.01）.FCM analysis showed that the percentage of apoptosis cells in PADI4 siRNA group in FLS was （5.4±0.6）% （t=-19.223,P〈0.01） and （6.1±0.6）% respectively （t=-24.229,P〈0.01）,which was significantly higher than that in the control group in FLS （1.6±0.3）%.The expression of CyclinB1 protein was decreased,and P21 increased.The concentrations of IL-1β in culture medium of the transfected group were （26.8±0.7） ng/ml （t=-10.747,P〈0.01） and （27.7±0.7） ng/ml （t=-10.967,P〈0.01）,higher than the control group [（23.9±0.7） ng/ml].Conclusion After being transfected with PADI4 siRNA,the apoptosis of FLS cells in RA is increased.Our results have demonstrated the potential role of CyclinB1 and P21 in PADI4 signaling.