Cigarette smoke-induced exosomal miR-221-3p facilitates M1 macrophage polarization via the STAT3 pathway in chronic obstructive pulmonary disease

Aims: Chronic obstructive pulmonary disease (COPD) is marked by irreversible airflow limitations stemming from small airway constriction and lung emphysema. The advancement of COPD is greatly influenced by the M1 polarization of macrophages. The mechanisms governing macrophage polarization in inflammation conditions in COPD are not yet fully understood. Methods: To investigate the interplay between exosomes triggered by cigarette smoke and the polarization of macrophages, we utilized a combination of flow cytometry, quantitative real-time reverse transcription PCR, and western blot analysis. Results: Our research reveals that cigarette smoke (CS) exposure induces the secretion of exosomes from human bronchial epithelial cells, with exosomal miR-221-3p identified as a key player in modulating the polarization of M1 macrophages. The evidence indicates that cigarette smoke promotes exosome secretion in these cells, with exosomal miR-221-3p targeting SOCS3 and regulating the STAT3 signaling pathway to facilitate M1 macrophage polarization. Conclusions: This research delves into the molecular pathways through which miR-221-3p facilitates the polarization of M1 macrophages, presenting a groundbreaking approach for potential targeted therapy in COPD.