The apoptosis of renal tubular epithelial cells (TECs) during ischemia/reperfusion (I/R) facilitates the progression of acute kidney injury (AKI). This study aimed to probe the role of long noncoding RNA maternally expressed 3 (MEG3) in I/R‐induced apoptosis of TECs. In this study, with CoCl₂ and hypoxia/reoxygenation treatments, cell models were established to mimic I/R using the human kidney tubular cell line HK‐2. In HK‐2 cells, expression of MEG3 detected using quantitative real‐time polymerase chain reaction (qRT‐PCR), was significantly upregulated after CoCl₂ treatment and hypoxia/reoxygenation treatment. The results of cell counting kit‐8 assay and flow cytometry suggested that knockdown of MEG3 significantly increased the viability of HK‐2 cells but inhibited its apoptosis, while overexpression of MEG3 exerted the reverse effects. Additionally, expression levels of interleukin 6 and tumor necrosis factor‐α in the medium were elevated after MEG3 was overexpressed in HK‐2 cells. Together with qRT‐PCR and Western blot analysis, a dual‐luciferase reporter gene assay was used to verify the interactions among MEG3, miR‐129‐5p, and HMGB1. The results demonstrated that in HK‐2 cells, miR‐129‐5p was a target of MEG3, and HMGB1 served as a target gene of miR‐129‐5p. Besides this, compared with the control group, the expression levels of MEG3 and HMGB1 in samples derived from AKI patients were remarkably upregulated, and the expression of miR‐129‐5p was downregulated. Therefore, taken together, we conclude that the overexpression of MEG3 induced by I/R promotes apoptosis of TECs via regulating the miR‐129‐5p/HMGB1 axis.

中文翻译：

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MEG3通过miR‐129‐5p / HMGB1轴加重缺氧/复氧诱导的肾小管上皮细胞凋亡

缺血/再灌注（I / R）期间肾小管上皮细胞（TECs）的凋亡促进了急性肾损伤（AKI）的发展。这项研究旨在探讨母体表达的长非编码RNA 3（MEG3）在I / R诱导的TECs凋亡中的作用。在这项研究中，通过CoCl ₂和缺氧/复氧治疗，使用人肾小管细胞株HK-2建立了模拟I / R的细胞模型。在HK-2细胞中，使用定量实时聚合酶链反应（qRT-PCR）检测到的MEG3的表达在CoCl ₂后显着上调治疗和缺氧/复氧治疗。细胞计数试剂盒-8分析和流式细胞仪的结果表明，敲低MEG3可以显着提高HK-2细胞的活力，但抑制其凋亡，而过表达MEG3则具有相反的作用。此外，在HK-2细胞中过表达MEG3后，培养基中白介素6和肿瘤坏死因子-α的表达水平升高。结合qRT-PCR和Western blot分析，使用双荧光素酶报告基因测定法来验证MEG3，miR-129-5p和HMGB1之间的相互作用。结果表明，在HK-2细胞中，miR-129-5p是MEG3的靶标，而HMGB1是miR-129-5p的靶标基因。除此之外，与对照组相比，AKI患者样本中MEG3和HMGB1的表达水平显着上调，而miR‐129-5p的表达则下调。因此，综上所述，我们得出的结论是I / R诱导的MEG3过表达通过调节miR‐129‐5p / HMGB1轴促进TECs的凋亡。