MiR-574-5p alleviates sepsis-induced acute lung injury by regulating TRAF6/NF-κB pathway

Purpose: To investigate the protective effect of miR-574-5p pretreatment against acute lung injury (ALI) induced by sepsis. Methods: A male C57BL/6 mouse model of sepsis-induced ALI was established by cecal ligation and puncture (CLP) and treated with miR-574-5p agomir (intravenous injection, 80 mg/kg per day, 3 days). After that, blood and lung samples were obtained for histopathological observation. Myeloperoxidase (MPO) activity, inflammatory cell infiltration, and cytokine expression were analyzed. The target gene of miR-574-5p was predicted using TargetScan prediction, and verified by luciferase assay and western blot. Results: In sepsis-induced ALI mice model, downregulation of miR-574-5p was observed. Pretreatment of miR-574-5p significantly alleviated ALI by suppressing histological damage, and reducing MPO activity and inflammatory cell infiltration, as well as decreasing cytokine expression. The underlying mechanism was that miR-574-5p targeted TNF receptor associated factor 6 (TRAF6) and suppressed the downstream NF-kappa B pathway. Moreover, TRAF6 overexpression reversed the effects of miR-574-5p on ALI. Conclusion: MiR-574-5p pretreatment suppresses inflammatory responses, thus reducing lung injury induced by sepsis in mice, partly via the regulation of TRAF6 and NF-kappa B pathway. Therefore, this approach can potentially be used for the clinical management of ALI in humans