SIRT1 通过降低NF-kB p65 表达减轻 异烟肼致人肝细胞损伤的研究

SIRT1 protects human liver cells from Isoniazid-induced injury by decreasing expression of NF-kB p65

摘要:

目的 探讨沉默信息调节因子1（SIRT1）在异烟肼致人肝细胞损伤中的作用。方法 培养人正常 肝细胞HL-7702，实验分为6 组：空白对照组、异烟肼组、异烟肼+SIRT1 激动剂组、SIRT1 激动剂对照组、 异烟肼+SIRT1 抑制剂组、SIRT1 抑制剂对照组。取各组细胞上清液测定丙氨酸转氨酶（ALT）、天门冬氨 酸转氨酶（AST）含量；实时荧光定量聚合酶链反应（qRT-PCR）检测肝细胞SIRT1、NF-kB p65 mRNA 表达水平；酶联免疫吸附法（ELISA）检测SIRT1、核转录因子kB（NF-kB p65）、白细胞介素6（IL-6）、 肿瘤坏死因子α（TNF-α）蛋白表达水平。结果 与空白对照组比较，异烟肼组细胞SIRT1 的mRNA 和 蛋白表达下降（P <0.05），其下游靶基因NF-kB p65 的mRNA 和蛋白表达升高（P <0.05），炎症因子IL-6、 TNF-α 蛋白表达水平升高（P <0.05）。加入SIRT1 激动剂可减轻异烟肼引起的炎症反应，加入SIRT1 抑制 剂可使NF-kB p65、IL-6、TNF-α 表达水平进一步升高从而加重细胞的炎症损伤。结论 异烟肼诱导肝细 胞损伤过程中，降低SIRT1 水平，增加炎症因子的表达。SIRT1 的激活可以通过降低NF-kB p65 表达进而减 轻肝细胞损伤的发生。

Abstract:

Objective To investigate the effect of silent information regulator 1 (SIRT1) on liver injury induced by Isoniazid (INH) in human normal liver cells HL-7702. Methods HL-7702 cells were cultured in RPMI 1640 supplemented with 10% FBS and divided into 6 groups including a control group, an INH group, an INH+SRT1720 group, a SRT1720 group, an INH+EX527 group and an EX527 group. The content of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in cell supernatant was determined. The expressions of SIRT1 and nuclear factor kappa B p65 (NF-kB p65) mRNAs were analyzed by qRT-PCR. The concentrations of SIRT1 and NF-kB p65 proteins, interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) were detected by ELISA. Results Compared with the control group, the expressions of SIRT1 at mRNA and protein levels were decreased (P < 0.05), the expression levels of NF-kB p65 mRNA and protein were significantly increased (P < 0.05), and the secretion of IL-6 and TNF-α also increased (P < 0.05) in the INH group. Adding SRT1720 could relieve the inflammatory reaction caused by INH. However, the expression levels of NF-kB p65, IL-6 and TNF-α were significantly enhanced by a SIRT1 inhibitor EX527. Conclusions Isoniazid can bring out the liver injury, decrease the level of SIRT1 and increase the levels of inflammatory factors. The activation of SIRT1 can inhibit the expressions of NF-kB p65 and inflammatory factors, then reduce the occurrence of hepatocyte injury.