Exosomal cytokine profile on lipopolysaccharide-induced acute lung injury in mice

Acute lung injury (ALI) is a severe inflammatory condition marked by alveolar damage and cytokine dysregulation. Exosomes, as carriers of bioactive molecules, regulate immune responses through intercellular communication. However, the cytokine profile of serum-derived exosomes during ALI remains unclear, and their functional role in modulating inflammation is poorly defined. A murine model of ALI was established via intraperitoneal injection of lipopolysaccharide (LPS, 10 mg/kg), and samples were collected at 2 h and 8 h post-injection. Lung injury severity was assessed using hematoxylin and eosin staining and lung W/D weight ratio. Serum-derived exosomes were isolated using the ExoQuick precipitation method and characterized by transmission electron microscopy and western blotting. Cytokine and chemokine profiles were quantified using a 32-plex Luminex xMAP assay. Exosome-mediated immune modulation was evaluated through a scratch migration assay in RAW264.7 macrophages. LPS treatment led to increased pulmonary edema and histopathological damage, which were more pronounced at 8 h. A total of 14 cytokines in the serum, including IL-6, TNF-α, and MCP-1, were significantly elevated at either 2-8 h compared to the control group. However, chemokines such as IP-10, G-CSF, and MIP-1β were markedly upregulated in serum-derived exosomes from ALI mice. Functional assays demonstrated that exosomes from ALI mice significantly enhanced the migratory capacity of RAW264.7 macrophages. This study demonstrates that serum-derived exosomes from ALI mice are enriched in specific chemokines and promote macrophage migration in vitro. These findings suggest that exosomes may participate in inflammatory cell recruitment during ALI and hold potential as biomarkers or modulators in the inflammatory response.