There is emerging evidence suggesting that oxidative stress and DNA methylation can alter miRNA expression. However, little is known on the mechanism of miR‐17‐5p expression changes in paraquat (PQ)‐induced nerve cell damage. In the present study, neuro‐2a cells were pretreated with antioxidant N‐acetylcysteine (NAC) or DNA methylation inhibitor decitabine (DAC), then exposed to different concentrations of PQ, while the expression levels of miR‐17‐5p were detected by qRT‐PCR. Here, it is showed that PQ downregulated the expression of miR‐17‐5p dose‐dependently in neuro‐2a cells. The DNA methylation level was upregulated after PQ exposure, while downregulated with the pretreatment of NAC in the above content, detected by 5‐mC immunofluorescence technique. The interaction effect of NAC and PQ in alternating DNA methylation level was further confirmed by flow cytometry. NAC and DAC individually had an interaction effect in PQ‐induced nerve cell damage. After using NAC, PQ‐induced ROS elevation and DNA methylation are reduced, thereby preventing the proapoptotic effect of miR‐17‐5p. Above all, PQ can induce DNA methylation variations through ROS production, leading to the downregulation of miR‐17‐5p expression in PQ‐induced nerve cell damage.

中文翻译：

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百草枯诱导的神经细胞损伤中活性氧通过DNA甲基化调节miR-17-5p的表达

有新的证据表明氧化应激和 DNA 甲基化可以改变 miRNA 的表达。然而，对百草枯（PQ）诱导的神经细胞损伤中 miR-17-5p 表达变化的机制知之甚少。在本研究中，用抗氧化剂 N-乙酰半胱氨酸 (NAC) 或 DNA 甲基化抑制剂地西他滨 (DAC) 预处理神经 2a 细胞，然后暴露于不同浓度的 PQ，同时通过 qRT 检测 miR-17-5p 的表达水平-聚合酶链反应。在这里，表明 PQ 剂量依赖性地下调神经 2a 细胞中 miR-17-5p 的表达。通过5-mC免疫荧光技术检测，PQ暴露后DNA甲基化水平上调，而上述内容中NAC预处理后DNA甲基化水平下调。流式细胞术进一步证实了 NAC 和 PQ 在交替 DNA 甲基化水平中的相互作用。NAC 和 DAC 分别在 PQ 诱导的神经细胞损伤中具有交互作用。使用 NAC 后，PQ 诱导的 ROS 升高和 DNA 甲基化减少，从而阻止了 miR-17-5p 的促凋亡作用。最重要的是，PQ 可以通过 ROS 产生诱导 DNA 甲基化变异，导致 PQ 诱导的神经细胞损伤中 miR-17-5p 表达的下调。