The lncRNA nuclear enriched abundant transcript 1 (NEAT1) promotes sepsis-inflammatory responses and acute kidney injury (AKI), but little known about the underlying mechanisms. This study aims to investigate the roles of NEAT1 in regulating macrophage polarization and its potential for alleviating inflammatory responses during sepsis pathogenesis. Mouse RAW264.7 macrophages were treated with lipopolysaccharide (LPS) as a cellular inflammatory model. NEAT1 shRNA, miR-125a-5p mimics, and TRAF6-overexpressing vector were used to transfect RAW264.7 cells. NEAT1, miR-125a-5p, and mRNA levels of functional genes were detected by quantitative RT-PCR. Protein abundances were analyzed by western blotting. Macrophage polarization was evaluated by flow cytometry. The bindings of miR-125a-5p with NEAT1 or TRAF6 gene were validated by dual luciferase reporter assay. LPS treatment promoted NEAT1 and suppressed miR-125a-5p expression in mouse macrophage cells. NEAT1 silencing by shRNAs promoted macrophage M2 polarization under LPS treatment, which upregulated miR-125a-5p expression, repressed TRAF6 expression and TAK1 protein phosphorylation in macrophages. These cellular and molecular changes induced by NEAT1 shRNAs were abrogated by miR-125a-5p inhibitors. Moreover, miR-125a-5p mimics suppressed TRAF6 expression and TAK1 protein phosphorylation in LPS-treated macrophages, thus causing macrophage M2 polarization under LPS treatment. TRAF6 overexpression abrogated the miR-125a-5p mimics-induced macrophage M2 polarization. miR-125a-5p could directly bind to NEAT1 or TRAF6 gene in macrophages. lncRNA NEAT1 knockdown ameliorates LPS-induced inflammation by promoting macrophage M2 polarization via miR-125a-5p/TRAF6/TAK1 axis.

中文翻译：

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lncRNA NEAT1 的下调通过 miR-125a-5p/TRAF6/TAK1 轴促进巨噬细胞 M2 极化来改善 LPS 诱导的炎症反应。

lncRNA 核富集的丰富转录物 1 (NEAT1) 促进脓毒症炎症反应和急性肾损伤 (AKI)，但对其潜在机制知之甚少。本研究旨在探讨 NEAT1 在调节巨噬细胞极化中的作用及其在脓毒症发病过程中减轻炎症反应的潜力。用脂多糖 (LPS) 作为细胞炎症模型处理小鼠 RAW264.7 巨噬细胞。NEAT1 shRNA、miR-125a-5p 模拟物和 TRAF6 过表达载体用于转染 RAW264.7 细胞。通过定量RT-PCR检测功能基因的NEAT1、miR-125a-5p和mRNA水平。通过蛋白质印迹分析蛋白质丰度。通过流式细胞术评估巨噬细胞极化。通过双荧光素酶报告基因测定验证了 miR-125a-5p 与 NEAT1 或 TRAF6 基因的结合。LPS 处理促进 NEAT1 并抑制小鼠巨噬细胞中 miR-125a-5p 的表达。shRNA 的 NEAT1 沉默在 LPS 处理下促进巨噬细胞 M2 极化，从而上调 miR-125a-5p 表达，抑制巨噬细胞中 TRAF6 表达和 TAK1 蛋白磷酸化。这些由 NEAT1 shRNA 诱导的细胞和分子变化被 miR-125a-5p 抑制剂消除。此外，miR-125a-5p 模拟物抑制 LPS 处理的巨噬细胞中的 TRAF6 表达和 TAK1 蛋白磷酸化，从而在 LPS 处理下引起巨噬细胞 M2 极化。TRAF6 过表达消除了 miR-125a-5p 模拟物诱导的巨噬细胞 M2 极化。miR-125a-5p 可以直接与巨噬细胞中的 NEAT1 或 TRAF6 基因结合。