Department of General Practice, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, No.19, Xiuhua Road, Haikou, 570311, Hainan Province, People's Republic of China.
Key Laboratory of Emergency and Trauma, Ministry of Education, Key Laboratory of Hainan Trauma and Disaster Rescue, The First Affiliated Hospital of Hainan Medical University, College of Emergency and Trauma, Hainan Medical University, Haikou, 571199, Hainan Province, People's Republic of China.
Mol Cell Biochem. 2023 Apr;478(4):743-754. doi: 10.1007/s11010-022-04521-1. Epub 2022 Sep 8.
Acute lung injury (ALI) caused by sepsis is characterized by a destructive high inflammatory response in lungs, which is the ultimate cause of high mortality to patients diagnosed with sepsis. The objective of the present study is to explore the effect and related mechanisms of circEXOC5 on pyroptosis in septic ALI. Sepsis ALI mouse model was induced and established by CLP induction and sepsis MPVEC cell model by LPS. HE staining was used to detect lung tissue pathological changes. ELISA, flow cytometry, and Western blot were utilized to evaluate the release of inflammatory cytokines and cell pyroptosis, and RIP was applied to verify the binding relationship between EZH2 and circEXOC5 or Nrf2. Finally, the interaction between CircEXOC5 and EZH2, H3k27me3, and Nrf2 promoter regions was clarified using ChIP. CircEXOC5 levels were notably ascended in the lung tissues of septic ALI mice. And silencing circEXOC5 inhibited cell pyroptosis and the release of inflammatory cytokines in MPVEC stimulated by LPS. In addition, RIP and ChIP indicated that Nrf2 expression in MPVECs cells could be inhibited by circEXOC5 via recruiting EZH2. In addition, ML385 (a specific inhibitor of Nrf2) reversed the efficacy of Knockdown of circEXOC5 on the Inhibition of pyroptosis and inflammation of MPVEC cells stimulated by LPS. These results indicated that CircEXOC5 could promote cell pyroptosis through epigenetic inhibition of Nrf2 in septic ALI.
脓毒症引起的急性肺损伤 (ALI) 的特征是肺部破坏性的高炎症反应，这是导致脓毒症患者死亡率高的最终原因。本研究旨在探讨 circEXOC5 对脓毒症 ALI 细胞焦亡的作用及相关机制。通过 CLP 诱导建立脓毒症 ALI 小鼠模型，通过 LPS 诱导建立脓毒症 MPVEC 细胞模型。HE 染色检测肺组织病理变化。ELISA、流式细胞术和 Western blot 用于评估炎症细胞因子的释放和细胞焦亡，RIP 用于验证 EZH2 和 circEXOC5 或 Nrf2 之间的结合关系。最后，利用 ChIP 阐明 CircEXOC5 与 EZH2、H3k27me3 和 Nrf2 启动子区域的相互作用。脓毒症 ALI 小鼠肺组织中 circEXOC5 水平明显升高。沉默 circEXOC5 抑制 LPS 刺激的 MPVEC 细胞焦亡和炎症细胞因子的释放。此外，RIP 和 ChIP 表明 circEXOC5 可通过募集 EZH2 抑制 MPVEC 细胞中 Nrf2 的表达。此外，ML385（Nrf2 的特异性抑制剂）逆转了 Knockdown of circEXOC5 对 LPS 刺激的 MPVEC 细胞焦亡和炎症抑制的作用。这些结果表明 CircEXOC5 可通过表观遗传抑制 Nrf2 促进脓毒症 ALI 中的细胞焦亡。
