MARK4在甲基苯丙胺诱导急性肾损伤中的作用

Role of MARK4 in methamphetamine-induced acute kidney injury

目的:甲基苯丙胺(methamphetamine,METH)是一种非法的精神活性物质,可以损害身体的各个器官,其中泌尿系统是其毒性作用的重要靶标之一。本研究旨在探讨微管亲和调控激酶4(microtubule affinity regulating kinase 4,MARK4)在METH诱导急性肾损伤(acute kidney injury,AKI)中的作用。方法:选取10只健康成年雄性C57BL/6小鼠,随机分为对照组和METH组,每组5只。METH组腹腔注射METH(20 mg/kg,每天1次,连续3 d),对照组腹腔注射同等体积的生理盐水。末次注射24 h后处死小鼠,通过血清肌酐、血尿素氮和肾脏HE染色检测AKI模型是否建立成功;蛋白质组学技术筛选METH诱导AKI的肾脏组织与正常肾脏组织之间差异表达的蛋白质,并进行基因本体(gene ontology,GO)分析、京都基因与基因组百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)分析和生物信息学分析;蛋白质印迹法验证蛋白质组学数据的准确性,选择目标分子,检测小鼠肾脏中MARK4和cleaved caspase-3表达情况。进一步探讨MARK4在METH诱导AKI中的作用。首先在BUMPT细胞中建立METH毒性模型,筛选出合适的METH处理浓度和时间;使用抑制剂抑制MARK4的表达,检测METH处理后BUMPT细胞的活力以及cleaved caspase-3表达情况。结果:蛋白质组学分析共筛选出差异表达蛋白质17个,其中上调11个,下调6个(均P<0.05)。METH处理后小鼠肾脏中MARK4和cleaved caspase-3的表达水平升高(均P<0.05)。BUMPT细胞的活性随METH处理浓度升高而逐渐降低(均P<0.05),其中4 mmol/L的METH处理后BUMPT细胞活力下降至60%。与对照组相比,MARK4和cleaved caspase-3的表达水平随着METH处理浓度的升高和处理时间的延长而升高(均P<0.05),呈浓度和时间依赖性。抑制MARK4表达可以改善METH引起的BUMPT细胞活性下降情况,降低cleaved caspase-3表达,减少BUMPT细胞的细胞凋亡。结论:MARK4在METH诱导AKI小鼠模型中高表达,MARK4通过调控细胞凋亡来介导METH中毒所致AKI。

Objective:Methamphetamine(METH)is an illicit psychoactive substance that can damage various organs,with the urinary system being one of its significant targets.This study aims to explore the role of microtubule affinity-regulating kinase 4(MARK4)in METH-induced acute kidney injury(AKI).Methods:A total of 10 healthy adult male C57BL/6 mice were randomly divided into a control group and a METH group,5 mice in each group.The METH group was administered METH(20 mg/kg,intraperitoneally,once daily for 3 consecutive days),while the control group received an equal volume of physiological saline.The mice were executed 24 hours after the final injection,and the success of the AKI model was detected by blood serum creatinine,blood urea nitrogen,and renal HE staining.Proteins differentially expressed between kidney tissues with METH-induced AKI and normal kidney tissues were screened by proteomics techniques and subjected to gene ontology(GO),Kyoto Encyclopedia of Genes and Genomes(KEGG)and bioinformatics analysis.The accuracy of proteomic data was validated using Western blotting,and the expression levels of MARK4 and cleaved caspase-3 in mouse kidneys were measured.We further explored the role of MARK4 in METH-induced AKI.Firstly,a METH toxicity model was established in BUMPT cells to screen the appropriate concentration and time of METH treatment;the viability of BUMPT cells after METH treatment and the expression of cleaved caspase-3 were detected by interfering with MARK4 expression through inhibitors.Results:The proteomic analysis of kidney tissues from METH and control groups screened for a total of 17 differentially expressed proteins,of which 11 were up-regulated and 6 were down-regulated(all P<0.05).The expression levels of MARK4 and cleaved caspase-3 were elevated in the kidneys of METH-treated mice(both P<0.05).The activity of BUMPT cells gradually decreased with increasing METH treatment concentration(all P<0.05),where the viability of BUMPT cells decreased to about 60%after METH treatment at 4 mmol/L.Compared with the control group,expression levels of MARK4 and cleaved caspase-3 were increased with higher METH concentrations and longer exposure times in a concentration-and time-dependent manner(all P<0.05).Inhibition of MARK4 expression improved METH-induced decrease in BUMPT cell activity,down-regulated the expression of cleaved caspase-3,and decreased the apoptosis of BUMPT cells induced by METH.Conclusion:MARK4 is highly expressed in a mouse model of METH-induced AKI,and MARK4 mediates METH-induced AKI by regulating cell apoptosis.