lncRNA SNHG1调控铁死亡减轻HIV-1 gp120 V3环所致小胶质细胞炎症的分子机制研究

Molecular mechanism of lncRNA SNHG1 regulating ferroptosis and at⁃tenuating inflammation of microglia induced by HIV-1 gp120 V3 loop

目的:探究长链非编码RNA(lncRNA)SNHG1调控铁死亡改善HIV-1 gp120 V3环致CHME-5人源小胶质细胞炎症的分子机制。方法:体外培养CHME-5人源小胶质细胞,设立空白组、随机肽段组、HIV-1 gp120V3环组(HIV-1 gp120组)、HIV-1 gp120+shCon组、HIV-1 gp120+SNHG1 sh2组、HIV-1 gp120+SNHG1 sh2+ferrostatin-1(Fer-1;铁死亡抑制剂)组和HIV-1 gp120+SNHG1 sh2+EX527(Sirt1抑制剂)组。随机肽段和gp120 V3环分别处理正常CHME-5细胞24 h;抑制剂预处理SNHG1 sh2细胞2 h后,gp120 V3环处理24 h。ELISA法检测细胞上清中炎症因子水平;Western blot法检测铁死亡相关蛋白[溶质载体家族7成员11(SLC7A11)和谷胱甘肽过氧化物酶4(GPX4)]、Sirt1和p53蛋白表达水平;酶标仪检测细胞内亚铁离子(Fe^(2+))和丙二醛(MDA)含量。结果:(1)ELISA结果显示:较空白组,HIV-1 gp120组炎症因子肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)和IL-1β表达水平显著提高(P<0.05);较HIV-1 gp120组,HIV-1 gp120+SNHG1 sh2组炎症因子表达水平显著降低(P<0.05);较HIV-1 gp120+SNHG1 sh2组,HIV-1 gp120+SNHG1 sh2+Fer-1组炎症因子表达水平显著降低(P<0.05),HIV-1 gp120+SNHG1 sh2+EX527组炎症因子表达水平显著升高(P<0.01)。(2)Western blot结果显示:较空白组,HIV-1 gp120组铁死亡相关蛋白SLC7A11和GPX4表达水平显著下调(P<0.01);较HIV-1 gp120组,HIV-1 gp120+SNHG1 sh2组SLC7A11和GPX4表达水平显著上调(P<0.01);较HIV-1 gp120+SNHG1 sh2组,HIV-1 gp120+SNHG1 sh2+Fer-1组SLC7A11和GPX4表达水平明显上调(P<0.05),HIV-1 gp120+SNHG1 sh2+EX527组SLC7A11和GPX4表达水平显著下调(P<0.01),p53表达水平显著上调(P<0.05)。(3)较空白组,HIV-1 gp120组Fe^(2+)和MDA含量显著提高(P<0.05);较HIV-1 HIV-1 gp120组,HIV-1 gp120+SNHG1 sh2组Fe^(2+)和MDA含量显著降低(P<0.01);较HIV-1 gp120+SNHG1 sh2组,HIV-1gp120+SNHG1 sh2+Fer-1组Fe^(2+)和MDA含量显著降低(P<0.05),HIV-1 gp120+SNHG1 sh2+EX527组Fe^(2+)和MDA含量显著提高(P<0.05)。结论:敲减SNHG1可减轻HIV-1 gp120 V3环介导的小胶质细胞炎症反应,其机制可能是通过Sirt1/p53信号通路调控铁死亡相关信号分子实现的。

AIM:To investigate the molecular mechanism of long noncoding RNA(lncRNA)SNHG1 in regu-lating ferroptosis to alleviate inflammation in CHME-5 human microglia induced by HIV-1 gp120 V3 loop.METHODS:CHME-5 human microglia were cultured in vitro,and were divided into 7 groups:blank group,random peptide group,gp120 V3 loop group(HIV-1 gp120 group),HIV-1 gp120+shCon group,HIV-1 gp120+SNHG1 sh2 group,HIV-1 gp120+SNHG1 sh2+ferrostatin-1(Fer-1;ferroptosis inhibitor)group,and HIV-1 gp120+SNHG1 sh2+EX527(Sirt1 in-hibitor)group.Normal CHME-5 cells were treated with random peptide or gp120 V3 loop for 24 h.After pretreatment of SNHG1 sh2 cells with inhibitors for 2 h,the cells were then treated with gp120 V3 loop for 24 h.The levels of inflammato-ry cytokines in the cell supernatants were detected by ELISA.Western blot was used to detect the protein expression levels of solute carrier family 7 member 11(SLC7A11),glutathione peroxidase 4(GPX4),Sirt1 and p53.Microplate reader was used to detect the levels of intracellular ferrous ion(Fe^(2+))and malondialdehyde(MDA).RESULTS:(1)The results of ELISA showed that the expression levels of tumor necrosis factor-α(TNF-α),interleukin-6(IL-6)and IL-1βin HIV-1 gp120 group were significantly higher than those in blank group(P<0.05).Compared with HIV-1 gp120 group,the ex-pression levels of inflammatory cytokines in HIV-1 gp120+SNHG1 sh2 group were significantly decreased(P<0.05).Compared with HIV-1 gp120+SNHG1 sh2 group,the expression levels of inflammatory factors in HIV-1 gp120+SNHG1 sh2+Fer-1 were significantly decreased(P<0.05),but those in HIV-1 gp120+SNHG1 sh2+EX527 group were significant-ly increased(P<0.01).(2)The results of Western blot showed that compared with blank group,the expression levels of ferroptosis-related proteins SLC7A11 and GPX4 in HIV-1 gp120 group were significantly down-regulated(P<0.01).Com-pared with HIV-1 gp120 group,the expression levels of SLC7A11 and GPX4 in HIV-1 gp120+SNHG1 sh2 group were sig-nificantly up-regulated(P<0.01).Compared with HIV-1 gp120+SNHG1 sh2 group,the expression levels of SLC7A11 and GPX4 in HIV-1 gp120+SNHG1 sh2+Fer-1 group were significantly up-regulated(P<0.05),but the expression levels of SLC7A11 and GPX4 in HIV-1 gp120+SNHG1 sh2+EX527 group were significantly down-regulated(P<0.01),and the expression level of p53 was significantly up-regulated(P<0.05).(3)Compared with blank group,the levels of Fe^(2+)and MDA in HIV-1 gp120 group were significantly increased(P<0.05).Compared with HIV-1 gp120 group,the levels of Fe^(2+)and MDA in HIV-1 gp120+SNHG1 sh2 group were significantly decreased(P<0.01).Compared with HIV-1 gp120+SNHG1 sh2 group,Fe^(2+)and MDA in HIV-1 gp120+SNHG1 sh2+Fer-1 group were significantly decreased(P<0.05),but those in HIV-1 gp120+SNHG1 sh2+EX527 group was significantly increased(P<0.05).CONCLUSION:Knockdown of SNHG1 can attenuate the inflammation in microglia induced by HIV-1 gp120 V3 loop,which may be achieved by regulating ferrop-tosis-related signaling molecules through the Sirt1/p53 signaling pathway.