M2 macrophage-derived small extracellular vesicles carrying canagliflozin attenuate experimental asthma

Asthma is a chronic inflammatory disorder characterized by immune dysregulation and structural remodeling of the airways, and current therapies remain insufficient, particularly for patients with refractory asthma. Emerging evidence highlights the importance of immunomodulation and local pulmonary administration in improving therapeutic outcomes. Hence, we developed M2 macrophage-derived small extracellular vesicles (M2-sEVs) carrying canagliflozin (CANA) for asthma.

M2-sEVs were isolated and loaded with CANA via ultrasonication to generate CANA-M2-sEVs. The vesicles were characterized by transmission electron microscopy, dynamic light scattering, zeta potential measurement, and sEV-associated marker analysis. Cellular uptake was evaluated using fluorescence imaging. Therapeutic efficacy was assessed in an ovalbumin (OVA)-induced murine asthma model through histological analysis, cytokine profiling, and gene expression assays. The involvement of the PI3K/AKT signaling pathway was investigated using western blotting and pharmacological modulation.

CANA-M2-sEVs retained vesicular morphology and showed nanoscale size distribution with mildly negative surface charge. CANA-M2-sEVs showed efficient, time-dependent cellular uptake in vitro and exerted therapeutic effects following pulmonary administration in vivo. In vivo, CANA-M2-sEVs significantly alleviated airway inflammation, reduced eosinophilic infiltration, and suppressed Th2-associated cytokine production. Moreover, airway remodeling features, including goblet cell metaplasia and collagen deposition, were markedly attenuated. Mechanistically, CANA-M2-sEVs effectively inhibited PI3K and AKT phosphorylation, while pharmacological activation of this pathway partially reversed their anti-inflammatory effects, supporting the involvement of this pathway.

This study suggests that CANA-associated M2-sEVs exert anti-inflammatory and anti-remodeling effects in experimental asthma, partly associated with suppression of PI3K/AKT signaling.