Department of Anesthesiology and Intensive Care, Changhai Hospital, The Naval Medical University, 168 Changhai Road, Yangpu District, Shanghai, 200433, People's Republic of China.
Med Microbiol Immunol. 2023 Oct;212(5):369-379. doi: 10.1007/s00430-023-00778-5. Epub 2023 Sep 1.
Sepsis is a severe syndrome caused by the imbalance of the host response to infection, accompanied by multiple organ damage, especially acute lung injury. SET Domain-Containing 2 (SETD2) is a methyltransferase catalyzing H3 lysine 36 trimethylation (H3K36me3) that regulates multiple biological processes. This study focused on explicating the action of SETD2 on macrophage function in sepsis and the precise mechanism involved. Enzyme-linked immunosorbent assay, real-time quantitative polymerase chain reaction (RT-qPCR), and Western blotting were used to determine expression. Luciferase reporter assay and chromatin immunoprecipitation assay were conducted to detect the binding of SETD2 or H3K36me3 with the hypoxia-inducible factor 1, alpha subunit (Hif1a) gene. A sepsis-induced acute lung injury model was constructed via cecal ligation and puncture (CLP). SETD2 was decreased in RAW 264.7 cells stimulated by lipopolysaccharide (LPS). Besides, SETD2 suppressed M1 macrophage polarization and glycolysis caused by LPS. HIF-1α was enhanced in RAW 264.7 cells stimulated by LPS and inversely related to SETD2 expression. In addition, SETD2-catalyzed H3K36me3 bound to the Hif1a gene to modulate HIF-1α expression. Furthermore, Hif1a silencing suppressed Setd2 silencing-induced M1 macrophage polarization and glycolysis in RAW 264.7 cells. Moreover, overexpression of Setd2 inhibited CLP-induced lung injury and M1 macrophage polarization in mice. SETD2 suppressed M1 macrophage polarization and glycolysis via regulating HIF-1α through catalyzing H3K36me3 in sepsis.
脓毒症是一种由宿主对感染的反应失衡引起的严重综合征，伴有多器官损伤，特别是急性肺损伤。SET 结构域包含蛋白 2（SETD2）是一种甲基转移酶，催化 H3 赖氨酸 36 三甲基化（H3K36me3），调节多种生物学过程。本研究旨在阐明 SETD2 在脓毒症中对巨噬细胞功能的作用及其具体机制。酶联免疫吸附试验、实时定量聚合酶链反应（RT-qPCR）和 Western blot 用于确定表达。荧光素酶报告基因检测和染色质免疫沉淀检测用于检测 SETD2 或 H3K36me3 与缺氧诱导因子 1，α亚基（Hif1a）基因的结合。通过盲肠结扎和穿刺（CLP）构建脓毒症诱导的急性肺损伤模型。脂多糖（LPS）刺激 RAW 264.7 细胞时，SETD2 减少。此外，SETD2 抑制 LPS 引起的 M1 巨噬细胞极化和糖酵解。LPS 刺激 RAW 264.7 细胞时 HIF-1α 增强，与 SETD2 表达呈负相关。此外，SETD2 催化的 H3K36me3 与 Hif1a 基因结合，调节 HIF-1α 的表达。此外，沉默 Hif1a 抑制了 RAW 264.7 细胞中 Setd2 沉默诱导的 M1 巨噬细胞极化和糖酵解。此外，过表达 Setd2 抑制了 CLP 诱导的小鼠肺损伤和 M1 巨噬细胞极化。SETD2 通过在脓毒症中催化 H3K36me3 调节 HIF-1α 来抑制 M1 巨噬细胞极化和糖酵解。
