抑制干扰素诱导蛋白16表达减少人主动脉外膜成纤维细胞凋亡

Inhibition of Interferon-inducible Protein 16 Expression Reduces the Apoptosis in Human Aortic Adventitial Fibroblasts

目的:研究干扰素诱导蛋白16(IFI16)表达抑制后对人主动脉外膜成纤维细胞(HAAFs)凋亡的影响。方法:应用IFI16基因小干扰RNA(siRNA)转染HAAFs使IFI16基因沉默(IFI16-siRNA组),以非特异性siRNA转染作为其转染阴性对照组(Con-siRNA组),未经处理的HAAFs作为未干预阴性对照组(Neg组)。应用流式细胞仪检测细胞周期及凋亡,实时定量逆转录-聚合酶链反应(Realtime qRT-PCR)检测细胞中IFI16 mRNA表达变化,蛋白免疫印迹(Western blotting)检测IFI16、抑癌因子(p53)、细胞周期依赖性蛋白激酶抑制因子p21^(WAF)(p21)、B细胞淋巴瘤-2(Bcl-2)相关X蛋白(Bax)及Bcl-2蛋白表达。结果:IFI16-siRNA组与Con-siRNA组、Neg组相比,细胞凋亡率[(3.33±0.41)%vs(7.42±1.51)%(、6.49±1.10)%,P<0.05]与G_0/G_1期细胞比例[(56.64±4.77)%vs(69.67±3.54)%、(68.29±4.14)%,P<0.05]减少;而S期细胞比例[(25.23±5.19)%vs(13.76±2.07)%、(14.04±3.00)%,P<0.05]增加;伴随着IFI16mRNA表达减少(P<0.05),以及IFI16-siRNA组IFI16、p53、p21、Bax蛋白表达量减少(P<0.05);同时Bcl-2蛋白表达量增加(P<0.05)。结论:抑制IFI16表达可减少HAAFs细胞凋亡,促进细胞周期G_1/S转换,其机制部分与抑制p53/p21信号通路及调控Bax/Bcl-2表达有关。

Objective： To study the impact of interferon-inducible protein 16 （IFI16） inhibition on apoptosis of human aortic adventitial fibroblasts （HAAFs）. Methods： Our research included 3 grouPs： （1） IFI16-siRNA group, specific small interference RNAs （siRNAs） of IFI16 were transfected into HAAFs in vitro to make IFI16 gene silence, （2） Con-siRNA group, non-specific siRNAs were transfected into HAAFs as negative control and （3）Untreated HAAFs group, blank control. HAAFs cell cycle and apoptosis rate were examined by flow cytometry, IFI16 mRNA expression was measured by real time qRT-PCR, protein expressions oflFI16, p53, p21, Bax and Bcl-2 were detected by Western blot analysis. Results： Compared with Con-siRNA group and Untreated HAAFs group, IFI16-siRNA group showed decreased apoptosis rate of HAAFs （3.33±0.41） % vs （7.42±1.51） % and （6.49±1.10） %, P〈0.05, reduced ratio of G0/Glphase cells （56.64 ± 4.77 ） % vs （69.67±3.54） % and （68.29±4.14） %, P〈0.05, while increased ratio of S phase cells （25.23±5.19） % vs （13.76±2.07） % and （14.04±3.00） %, P〈0.05. Meanwhile, IFI16-siRNA group presented down-regulated IFI16 mRNA and protein expressions, decreased protein levels of p53, p21, Bax and increased protein level of Bcl-2, all P〈0.05. Conclusion： Inhibited IFI16 expression could decrease HAAFs apoptosis, promote cell cycle transition from G1 to S phase which might be related to the suppression of p53/p21 signaling pathway and regulation of Bax/Bcl-2 expression.