Double-Responsive Macrophage-Derived Exosomes Alleviate Acute Lung Injury.

Acute lung injury (ALI) is one of the complications of sepsis, and macrophages play an important role in ALI. The aim of this research was to investigate the effects of epidermal growth factor receptor (EGFR) monoclonal antibody-modified chemokine (C-X-C motif) ligand 8 (CXCL8) overexpression of macrophage (CXCL8@M)-derived exosomes miR-126a-3p (EGFR@CXCL8@exo-miR-126a-3p) on sepsis ALI. CXCL8@M was obtained via macrophage infection of CXCL8 plasmid, and CXCL8-M-exo was obtained via an exosome extraction kit. In addition, hsa-miR-126-3p agomir [a specially chemically modified microRNA (miRNA) mimic, named miR-126-3p] was loaded in CXCL8@M-exo to form CXCR8@exo-miR-126a-3p via electroporation technology. Further, EGFR@CXCR8@exo-miR-126a-3p was obtained via EGFR monoclonal antibody-modified CXCR8@exo-miR-126a-3p. Lipopolysaccharide (LPS)-induced ALI models were used to evaluate the role and mechanism of EGFR@CXCR8@exo-miR-126a-3p on ALI. Single-cell sequencing and miRNA chip results showed that miR-126a-3p was mainly expressed in pulmonary macrophages and markedly decreased, while single-cell sequencing and immunofluorescence results showed that EGFR was expressed and significantly elevated in macrophages in ALI mice. miR-126a-3p and EGFR siRNA significantly inhibited polarization of M1 macrophage. The imaging results of small animals showed that EGFR@CXCL8-exo-miR-126a-3p has obvious macrophage targeting. The results showed that EGFR@CXCR8@exo-miR-126a-3p significantly inhibited M1 macrophage and increased Treg cells to exert anti-inflammatory effects. The mechanism of EGFR@CXCR8@exo-miR-126a-3p on ALI is mainly via inhibition of PIK3R2/NLRP3 signaling pathway and ferroptosis. This study provided a new treatment method for ALI.