Li Chen, Liu Jianhua, Zhang Changhong, Cao Liang, Zou Fang, Zhang Zhihua
Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Hebei North University, Zhangjiakou, 075000, Hebei Province, PR China.
Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Hebei North University, Zhangjiakou, 075000, Hebei Province, PR China.
Pulm Pharmacol Ther. 2023 Dec;83:102249. doi: 10.1016/j.pupt.2023.102249. Epub 2023 Aug 28.
Acute lung injury (ALI) is a common complication of sepsis. Dihydroquercetin (DHQ) has been found to attenuate lipopolysaccharide (LPS)-induced inflammation. However, the effect of DHQ on LPS-challenged ALI remains unclear.
Pulmonary HE and TUNEL staining and lung wet/dry ratio were detected in LPS-treated Balb/c mice. IL-1β, IL-6 and TNF-α levels were determined utilizing ELISA assay. RAW264.7 cell apoptosis and macrophage markers (CD86, CD206) were tested using flow cytometry. TC-1 viability was analyzed by MTT assay. Western blot measured protein expression of macrophage markers. Interactions of miR-132-3p, IRF4 and FBXW7 were explored utilizing ChIP, RNA pull-down and dual luciferase reporter assays.
DHQ alleviated histopathological change, pulmonary edema and apoptosis in LPS-treated mice. DHQ affected LPS-induced M2 macrophage polarization and TC-1 cell injury-related indicators, such as decreased cell activity, decreased LDH levels, and increased apoptosis. LPS inhibited IRF4 and miR-132-3p expression, activated Notch pathway and increased FBXW7 level, which were overturned by DHQ. IRF4 transcriptionally activated miR-132-3p expression. FBXW7 was a downstream target of miR-132-3p.
DHQ alleviated LPS-induced lung injury through promoting macrophage M2 polarization via IRF4/miR-132-3p/FBXW7 axis, which provides a new therapeutic strategy for ALI.
急性肺损伤（ALI）是脓毒症的常见并发症。已发现二氢槲皮素（DHQ）可减轻脂多糖（LPS）诱导的炎症。然而，DHQ对LPS诱导的ALI的影响仍不清楚。
检测LPS处理的Balb/c小鼠的肺组织苏木精-伊红（HE）染色、TUNEL染色及肺湿/干比。采用酶联免疫吸附测定（ELISA）法测定白细胞介素-1β（IL-1β）、白细胞介素-6（IL-6）和肿瘤坏死因子-α（TNF-α）水平。使用流式细胞术检测RAW264.7细胞凋亡及巨噬细胞标志物（CD86、CD206）。通过MTT法分析TC-1细胞活力。蛋白质印迹法检测巨噬细胞标志物的蛋白表达。利用染色质免疫沉淀（ChIP）、RNA下拉和双荧光素酶报告基因测定法探究微小RNA-132-3p（miR-132-3p）、干扰素调节因子4（IRF4）和F-box和WD重复结构域蛋白7（FBXW7）之间的相互作用。
DHQ减轻了LPS处理小鼠的组织病理学变化、肺水肿和细胞凋亡。DHQ影响LPS诱导的M2巨噬细胞极化及TC-1细胞损伤相关指标，如细胞活性降低、乳酸脱氢酶（LDH）水平降低和细胞凋亡增加。LPS抑制IRF4和miR-132-3p表达，激活Notch信号通路并增加FBXW7水平，而DHQ可逆转这些变化。IRF4转录激活miR-132-3p表达。FBXW7是miR-132-3p的下游靶点。
DHQ通过IRF4/miR-132-3p/FBXW7轴促进巨噬细胞M2极化，减轻LPS诱导的肺损伤，为ALI提供了一种新的治疗策略。
