Liao Weitang, Fu Zongjie, Zou Yanfang, Wen Dan, Ma Hongkun, Zhou Fangfang, Chen Yongxi, Zhang Mingjun, Zhang Wen
Department of Nephrology, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
Research center for experimental medicine of Ruijin Hospital, Shanghai, China.
Exp Cell Res. 2017 Nov 15;360(2):292-302. doi: 10.1016/j.yexcr.2017.09.019. Epub 2017 Sep 18.
Oxidative stress was predominantly involved in the pathogenesis of acute kidney injury (AKI). Recent studies had reported the protective role of specific microRNAs (miRNAs) against oxidative stress. Hence, we investigated the levels of miR140-5p and its functional role in the pathogenesis of Cisplatin induced AKI. A mice Cisplatin induced-AKI model was established. We found that miR-140-5p expression was markedly increased in mice kidney. Bioinformatics analysis revealed nuclear factor erythroid 2-related factor (Nrf2) was a potential target of miR-140-5p, We demonstrated that miR-140-5p did not affect Kelch-like ECH-associated protein 1 (Keap1) level but directly targeted the 3'-UTR of Nrf2 mRNA and played a positive role in the regulation of Nrf2 expression which was confirmed by luciferase activity assay and western blot. What was more, consistent with miR140-5p expression, the mRNA and protein levels of Nrf2, as well as antioxidant response element (ARE)-driven genes Heme Oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase l (NQO1) were significantly increased in mice kidney tissues. In vitro study, Enforced expression of miR-140-5p in HK2 cells significantly attenuated oxidative stress by decreasing ROS level and increasing the expression of manganese superoxide dismutase (MnSOD). Simultaneously, miR-140-5p decreased lactate dehydrogenase (LDH) leakage and improved cell vitality in HK2 cells under Cisplatin-induced oxidative stress. However, HK2 cells transfected with a siRNA targeting Nrf2 abrogated the protective effects of miR-140-5p against oxidative stress. These results indicated that miR-140-5p might exert its anti-oxidative stress function via targeting Nrf2. Our findings showed the novel transcriptional role of miR140-5p in the expression of Nrf2 and miR-140-5p protected against Cisplatin induced oxidative stress by activating Nrf2-dependent antioxidant pathway, providing a potentially therapeutic target in acute kidney injury.
氧化应激在急性肾损伤（AKI）的发病机制中起主要作用。最近的研究报道了特定微小RNA（miRNA）对氧化应激的保护作用。因此，我们研究了miR140 - 5p的水平及其在顺铂诱导的AKI发病机制中的功能作用。建立了小鼠顺铂诱导的AKI模型。我们发现miR - 140 - 5p在小鼠肾脏中的表达显著增加。生物信息学分析显示核因子红细胞2相关因子（Nrf2）是miR - 140 - 5p的潜在靶点，我们证明miR - 140 - 5p不影响 Kelch样ECH相关蛋白1（Keap1）的水平，但直接靶向Nrf2 mRNA的3'-UTR，并在Nrf2表达的调节中发挥积极作用，这通过荧光素酶活性测定和蛋白质印迹得到证实。此外，与miR140 - 5p的表达一致，Nrf2的mRNA和蛋白质水平以及抗氧化反应元件（ARE）驱动的基因血红素加氧酶-1（HO - 1）和NAD（P）H：醌氧化还原酶1（NQO1）在小鼠肾脏组织中显著增加。在体外研究中，HK2细胞中miR - 140 - 5p的过表达通过降低活性氧水平和增加锰超氧化物歧化酶（MnSOD）的表达显著减轻氧化应激。同时，在顺铂诱导的氧化应激下，miR - 140 - 5p降低了HK2细胞中乳酸脱氢酶（LDH）的泄漏并提高了细胞活力。然而，用靶向Nrf2的小干扰RNA转染HK2细胞消除了miR - 140 - 5p对氧化应激的保护作用。这些结果表明miR - 140 - 5p可能通过靶向Nrf2发挥其抗氧化应激功能。我们的研究结果显示了miR140 - 5p在Nrf2表达中的新转录作用，并且miR - 140 - 5p通过激活Nrf2依赖性抗氧化途径保护免受顺铂诱导的氧化应激，为急性肾损伤提供了一个潜在的治疗靶点。
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