A33-08 The Mechanism of Mac-BNIP3hi Mediating Mitophagy to Regulate Metabolic Stress in Abnormal Repair of Tracheal Injury

Objective Abnormal repair after tracheal injury is mainly manifested as airway granulation tissue proliferation and scar contracture, leading to airway stenosis and dyspnea, and even asphyxia death. The existing treatment effects are poor and may cause secondary injury, which is a clinical problem to be solved urgently. BNIP3 remodels macrophage metabolism by mediating mitophagy. The role of BNIP3 in tracheal injury repair has not been reported, and it may be an important target for the treatment of airway stenosis. This study aims to analyze the role of BNIP3-mediated mitophagy in the metabolic reprogramming of macrophages, reveal its dynamic changes in tracheal injury repair, and propose new ideas for targeting macrophage metabolism to promote airway regeneration. Methods The tracheal granulation tissue and normal tracheal tissue of patients with tracheal stenosis were collected, and single-cell transcriptome sequencing (scRNA-seq) was performed to analyze the regulatory characteristics of BNIP3 in macrophages. The expression and localization of BNIP3 and inflammatory markers IL1β, TNFα and IL6 were detected by immunofluorescence (IF), enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry (IHC). Metabolomics technology was used to find the downstream of BNIP3 regulation. Transmission electron microscopy and immunofluorescence confocal microscopy were used to observe autophagosomes and autophagic fluorescence flow. To observe the effect of glycolysis inhibitor on the repair of tracheal injury in animal models of different severity. Results BNIP3 expression in macrophages in the illness group was much higher than that in the control group (P < 0.05), according to scRNA-seq data, and this was significantly correlated with the inflammatory milieu in the airways. BNIP3 expression is positively linked with TNF-α, IL-1β, IL-6, and other inflammatory markers and is up-regulated in the sickness group of clinical and animal samples. In macrophages overexpressing BNIP3, mitophagy and glycolysis were elevated. After targeted delivery of glycolysis inhibitors, local inflammation was alleviated, granulation tissue was reduced, and airway stenosis was significantly improved in rats. Conclusion This study indicates that Mac-BNIP3hi drives the inflammatory load of macrophages through the mitophagy-glycolysis axis after tracheal injury, forming a vicious cycle of metabolism and immunity, leading to abnormal airway repair. The new strategy of targeting macrophage metabolic reprogramming can provide a new theoretical basis and therapeutic idea for the prevention and treatment of airway stenosis.