Molecular mechanism of lncRNA SNHG1 regulating ferroptosis and at-tenuating inflammation of microglia induced by HIV-1 gp120 V3 loop
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(Fe2+)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-1β in 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 Fe2+and MDA in HIV-1 gp120 group were significantly increased(P<0.05).Compared with HIV-1 gp120 group,the levels of Fe2+and MDA in HIV-1 gp120+SNHG1 sh2 group were significantly decreased(P<0.01).Compared with HIV-1 gp120+SNHG1 sh2 group,Fe2+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.