Abstract
Asthma is the most common chronic disease and is characterized by airway remodeling and chronic inflammation. Increasingly, studies have found that the activation and M1 phenotypic transformation of macrophages play important roles in asthma progress, including airway remodeling. However, the reversal of M1 macrophages to the M2 phenotype has been shown to attenuate airway remodeling. Exosomes are nano-sized extracellular vesicles derived from endosomes; they play direct roles in governing physiological and pathological conditions by the intracellular transfer of bioactive cargo, such as proteins, enzymes, nucleic acids (microRNA [miRNA], mRNA, DNA), and metabolites. However, transfer mechanisms are unclear. To uncover potential therapeutic mechanisms, we constructed an ovalbumin-induced asthma mouse model and lipopolysaccharide-induced RAW264.7 macrophages cells. High-throughput sequencing showed that mmu_circ_0001359 was downregulated in asthmatic mice when compared with normal mice. Adipose-derived stem cell (ADSC)-exosome treatment suppressed inflammatory cytokine expression by the conversion of M1 macrophages to the M2 phenotype, under lipopolysaccharide-induced conditions. Exosomes from mmu_circ_0001359 overexpression in ADSCs increased therapeutic effects, in terms of cytokine expression, when compared with wild-type exosomes. Luciferase reporter assays confirmed that exosomes from mmu_circ_0001359-modified ADSCs attenuated airway remodeling by enhancing FoxO1 signaling-mediated M2-like macrophage activation, via sponging miR-183-5p. In conclusion, mmu_circ_0001359-enriched exosomes attenuated airway remodeling by promoting M2-like macrophages.