miRNA-142-3p对肺泡巨噬细胞炎症过程的负向调控及其机制

目的 探索miRNA-142-3p（miR-142-3p）对脂多糖（LPS）诱导的大鼠肺泡巨噬细胞炎症反应的负向调控作用及其可能机制。方法 用100 ng/mL LPS诱导肺泡巨噬细胞NR8383，实时定量PCR（qPCR）和蛋白质印迹法分别检测诱导后0、6、24、48 h时细胞中miR-142-3p和高迁移率族蛋白（HMGB1）的表达。细胞体外转染miR-142-3p拟似物（miR-142-3p mimic），qPCR检测转染后细胞中miR-142-3p及炎症因子[肿瘤坏死因子α（TNF-α）、白介素（IL）-6、IL-1β和巨噬细胞炎症蛋白2β（MIP-2β）]的表达，蛋白质印迹法检测细胞中HMGB1的表达，酶联免疫吸附（ELISA）法检测细胞培养液中HMGB1的含量。结果 LPS诱导NR8383细胞后，细胞中miR-142-3p在48 h时表达最高，HMGB1在24 h时最高，与0 h时相比差异均有统计学意义（P<0.05）。过表达miR-142-3p后，NR8383细胞中miR-142-3p的表达升高（P<0.05），HMGB1 mRNA和蛋白及TNF-α、IL-6、IL-1β和MIP-2β mRNA的表达均降低（P<0.05）。结论 miR-142-3p能介导LPS诱导的NR8383细胞的炎症反应过程，该效应可能是通过负向调控HMGB1的表达来实现的。
Objective To explore the effect and the regulatory mechanism of miRNA-142-3p (miR-142-3p) in rat alveolar macrophage inflammatory response stimulated with lipopolysaccharide (LPS). Methods The rat alveolar macrophages NR8383 were stimulated with 100 ng/mL LPS, and the mRNA and protein expressions of miR-142-3p and high-mobility group box 1 (HMGB1) were determined by qPCR and Western blotting analysis after stimulating for 0, 6, 24 and 48 h. We then transfected the macrophage with miR-142-3p mimic in vitro and used qPCR to measure the mRNA expressions of miR-142-3p, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-1β and macrophage inflammatory protein 2β (MIP-2β). Western blotting analysis was used to measure the protein expression of HMGB1, and ELISA was used to observe the concentration of HMGB1 in cell culture fluid. Results The highest expression of miR-142-3p was found in NR8383 cells when stimulated with LPS for 48 h and the highest concentration of HMGB1 was noticed at 24 h stimulation, and they were significantly different from those at 0 h (P<0.05). After overexpression of miR-142-3p, the expression of miR-142-3p was significantly increased (P<0.05), and the expressions of HMGB1 protein and mRNA of HMGB1, TNF-α, IL-6, IL-1β and MIP-2β were significantly decreased (P<0.05). Conclusion miR-142-3p can mediate the NR8383 cell inflammatory response induced by LPS, which may be caused by negative regulation of HMGB1 expression