Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, Shanghai Respiratory Research Institute, Shanghai 200032, P.R. China.
Emergency Department, Zhongshan Hospital, Fudan University, Shanghai Respiratory Research Institute, Shanghai 200032, P.R. China.
Mol Med Rep. 2017 Oct;16(4):4964-4972. doi: 10.3892/mmr.2017.7184. Epub 2017 Aug 7.
Modulation of inflammation is a crucial component of the development of acute lung injury. A20, a ubiquitin editing enzyme, may regulate cellular inflammatory reactions, particularly those involving the signaling pathway of nuclear factor NF-κB (NF‑κB). The present study investigated the mechanism by which A20 downregulated NF‑κB and further contributed to macrophage polarization from the M1 to M2 phenotypes in lipopolysaccharide (LPS)‑induced lung injury. Sprague‑Dawley rats injected with LPS were used in the present study. Bronchoalveolar lavage fluid and lung tissue were collected from each experimental rat. A macrophage cell line was used to test the expression levels of A20. Tumor necrosis factor‑α (TNF‑α), interleukin‑1 beta (IL‑1β) and NF‑κB activities were assessed by ELISA and polymerase chain reaction. Macrophage phenotypes were assayed using fluorescence‑activated cell sorting. Elevated levels of TNF‑α, IL‑1β, NF‑κB and A20 were observed in the macrophages of rats treated with LPS. Furthermore, A20 overexpression inhibited NF‑κB DNA binding activity and increased macrophage polarization from the M1 to M2 phenotype in lung macrophages of the NR8383 cell line. It was concluded that the A20 protein in macrophages modulates lung injury induced by LPS. The overexpression of A20 in macrophages may be involved in modulating macrophage polarization. The mechanisms and molecular identification of macrophage polarization activation may provide a basis for the treatment of inflammation in lung injury.
炎症调节是急性肺损伤发展的关键组成部分。泛素编辑酶 A20 可能调节细胞炎症反应，特别是涉及核因子 NF-κB（NF-κB）信号通路的反应。本研究探讨了 A20 下调 NF-κB 的机制，并进一步促进了脂多糖（LPS）诱导的肺损伤中巨噬细胞从 M1 向 M2 表型的极化。本研究使用 LPS 注射的 Sprague-Dawley 大鼠。从每个实验大鼠收集支气管肺泡灌洗液和肺组织。使用巨噬细胞系来测试 A20 的表达水平。通过 ELISA 和聚合酶链反应评估肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）和 NF-κB 活性。使用荧光激活细胞分选测定巨噬细胞表型。用 LPS 处理的大鼠的巨噬细胞中观察到 TNF-α、IL-1β、NF-κB 和 A20 的水平升高。此外，A20 过表达抑制了 NF-κB DNA 结合活性，并增加了 NR8383 细胞系肺巨噬细胞中从 M1 向 M2 表型的极化。结论是巨噬细胞中的 A20 蛋白调节 LPS 诱导的肺损伤。巨噬细胞中 A20 的过表达可能参与调节巨噬细胞极化。巨噬细胞极化激活的机制和分子鉴定可为肺损伤中炎症的治疗提供依据。
