Department of Respiratory Medicine, China-Japan Union Hospital of Jilin University, Changchun, 130033, People's Republic of China.
Department of Infections, China-Japan Union Hospital of Jilin University, Changchun, 130033, People's Republic of China.
J Mol Med (Berl). 2020 Jun;98(6):907-921. doi: 10.1007/s00109-020-01910-1. Epub 2020 May 22.
Acute lung injury (ALI) is often associated with inflammation. Increasing evidence has identified the role for ubiquitin-specific protease 7 (USP7) in activating the expression of inflammatory factors in macrophages. The present study evaluated whether USP7 also mediates histone acetyltransferase Tat-interactive protein 60 (Tip60) in the development of ALI inflammation. An ALI mouse model was induced by intratracheal lipopolysaccharide (LPS) administration. Next, lung myeloperoxidase (MPO) activity and the ratio of dry weight/wet weight of lung were examined to evaluate tissue damage. In addition, RAW 264.7 cells were treated with LPS to induce an in vitro LPS-induced inflammatory cell model. ELISA was performed to measure expression of IL-1β, TNF-α, IL-6, and IL-8 in cells and tissues. TUNEL was used to detect LPS-induced cell apoptosis. Furthermore, the interaction between USP7 and Tip60 was identified by IP, Western blot analysis, and cycloheximide (CHX) treatment. The enrichment of Tip60 and H3K27ac in the promoter region of IL-6 and IL-8 was assessed by ChIP. USP7 was highly expressed in LPS-endotoxin-induced ALI mouse models and silencing of USP7 delayed the progression of ALI in mice. Silencing of USP7 protected RAW 264.7 cells against LPS-induced inflammation and apoptosis by downregulating IL-1β, TNF-α, IL-6, and IL-8. USP7 enhanced Tip60 protein stability, and Tip60 increased the enrichment of H3K27ac on IL-6 and IL-8 promoter region and activated NF-κB p65 to increase IL-6 and IL-8 expression. These findings reveal a new post-transcriptional role for USP7 in inflammation by stabilizing Tip60 and increasing the release of the pro-inflammatory cytokines, and implicate USP7 inhibitors as potential therapeutic agents for ALI. KEY MESSAGES: USP7 expresses highly in an acute lung injury (ALI) mouse models. Silencing of USP7 inhibits inflammation and cell apoptosis in ALI mouse. USP7 stabilizes Tip60 to boost the release of IL-6 and IL-8. Tip60 increases IL-6 and IL-8 expression by acetylating NF-κB p65. Silencing of USP7 alleviates ALI by repressing NF-κB p65 and Tip60.
急性肺损伤 (ALI) 常伴有炎症。越来越多的证据表明，泛素特异性蛋白酶 7 (USP7) 在激活巨噬细胞中炎症因子的表达中起作用。本研究评估了 USP7 是否也介导组蛋白乙酰转移酶 Tat 相互作用蛋白 60 (Tip60) 在 ALI 炎症的发展中发挥作用。通过气管内给予脂多糖 (LPS) 诱导 ALI 小鼠模型。然后，检查肺髓过氧化物酶 (MPO) 活性和肺干湿重比，以评估组织损伤。此外，用 LPS 处理 RAW 264.7 细胞以诱导体外 LPS 诱导的炎症细胞模型。通过 ELISA 测定细胞和组织中 IL-1β、TNF-α、IL-6 和 IL-8 的表达。用 TUNEL 检测 LPS 诱导的细胞凋亡。此外，通过免疫沉淀 (IP)、Western blot 分析和环己酰亚胺 (CHX) 处理鉴定 USP7 和 Tip60 之间的相互作用。通过 ChIP 评估 IL-6 和 IL-8 启动子区域中 Tip60 和 H3K27ac 的富集。USP7 在 LPS-内毒素诱导的 ALI 小鼠模型中高表达，USP7 的沉默延迟了小鼠 ALI 的进展。USP7 的沉默通过下调 IL-1β、TNF-α、IL-6 和 IL-8 来保护 RAW 264.7 细胞免受 LPS 诱导的炎症和凋亡。USP7 增强了 Tip60 蛋白的稳定性，Tip60 增加了 IL-6 和 IL-8 启动子区域上 H3K27ac 的富集，并激活 NF-κB p65 增加 IL-6 和 IL-8 的表达。这些发现揭示了 USP7 通过稳定 Tip60 和增加促炎细胞因子的释放在炎症中发挥新的转录后作用，并暗示 USP7 抑制剂可能是 ALI 的潜在治疗药物。 关键信息：USP7 在急性肺损伤 (ALI) 小鼠模型中高表达。USP7 的沉默抑制 ALI 小鼠的炎症和细胞凋亡。USP7 稳定 Tip60 以促进 IL-6 和 IL-8 的释放。Tip60 通过乙酰化 NF-κB p65 增加 IL-6 和 IL-8 的表达。沉默 USP7 通过抑制 NF-κB p65 和 Tip60 来减轻 ALI。
