8-氧代鸟嘌呤DNA糖基化酶在顺铂诱导的急性肾损伤中的作用和机制

The mechanism of 8⁃oxoguanine DNA glycosylase in Cisplatin⁃induced acute kidney injury

目的:探讨在顺铂诱导的急性肾损伤(AKI)中8-氧代鸟嘌呤DNA糖基化酶(OGG1)的作用及机制。方法:48只8~10周龄C57BL/6雄性小鼠构建动物模型。24只分为4组,每组6只,分别经腹注射顺铂干预0 h、24 h、48 h和72 h。剩余小鼠也随机分为4组,即生理盐水对照组、顺铂组、OGG1抑制剂组(Th5487组)和顺铂+Th5487组。分别在腹腔注射生理盐水或顺铂和Th5487。留取血液测定肌酐、尿素氮,取肾组织进行病理分析,检测肾组织8-氧代鸟嘌呤含量和超氧化物歧化酶活力,RT-qPCR测定mRNA水平,Western Blot验证OGG1和炎症蛋白表达情况。利用顺铂诱导小鼠肾小管上皮细胞建立体外模型,检测线粒体膜电位改变、活性氧生成情况和蛋白表达变化。结果:在顺铂诱导的AKI模型中,OGG1表达上调,环鸟苷酸-腺苷酸合成酶-干扰素基因刺激因子(cGAS-STING)信号轴及炎症反应激活;Th5487可抑制顺铂诱导的组织损伤、cGAS-STING信号轴的激活及炎性反应;在体外,Th5487可减少顺铂诱导的细胞中ROS含量升高及线粒体膜去极化。结论:在顺铂诱导的AKI过程中,OGG1可通过cGAS-STING信号促进肾脏损伤及炎症反应。

Objective:To investigate the role and mechanism of 8⁃oxoguanine DNA glycosylase(OGG1)in cisplatin⁃induced acute kidney injury(AKI).Methodology:Forty⁃eight C57BL/6 male mice aged 8-10 weeks were used to establish an in vivo animal model.Twenty⁃four mice were divided into four groups with 6 mice in each group.Cisplatin was injected intraperitoneally for 0h,24 h,48 h and 72 h,respectively.The remaining mice were also randomly divided into four groups:saline control group,cisplatin group,saline and Th5487 group,cisplatin and Th5487 group.Saline or cisplatin and Th5487 were injected intraperitoneally.Blood was taken to determine creatinine and urea nitrogen,and renal tissue was taken for pathological analysis.8⁃oxoguanine(8⁃oxoG)content and superoxide dismutase(SOD)activity were detected.The expression of OGG1 and inflammatory protein was verified by Western blot,and the level of mRNA was measured by RT⁃qPCR.The in vitro cell model of mouse renal tubular epithelial cells induced by cisplatin was established,and the changes of mitochondrial membrane potential(MMP),the production of reactive oxygen species(ROS)and the protein expression were detected.Results:In AKI induced by cisplatin,the expression of OGG1 was up⁃regulated,cGAS⁃STING signal and inflammation were activated,and OGG1 inhibitor Th5487 could alleviate the tissue injury and inhibit the activation of cGAS⁃STING signal and inflammation induced by cisplatin.In vitro,after cisplatin treatment in renal tubular epithelium,the MMP and ROS concentration increased significantly,and Th5487 could reduce the ROS content and mitochondrial membrane depolarization induced by cisplatin.Conclusion:In the process of cisplatin⁃induced AKI,OGG1 can promote renal injury and inflammation through cGAS⁃STING signal.