Secretome of EMSCs neutralizes LPS-induced acute lung injury via aerosol administration

Ectodermal mesenchymal stem cells (EMSCs) are cells harvested from the stem cell niche (nasal mucosa) with high therapeutic potential. To the best of our knowledge, however, the anti-inflammatory properties of these neural crest-derived EMSCs have been rarely reported. The present study aimed to explore the effects of aerosolized EMSC-Secretome (EMSC-Sec) and clarify underlying mechanisms in treating acute lung injury (ALI). EMSCs were isolated by adherent method and identified by immunofluorescence staining. EMSC-Sec was collected and evaluated using western blotting, BCA and ELISA tests. Then, mouse lung epithelial cells (MLE-12) were used to mimic inflammatory stimulation with lipopolysaccharide (LPS). After developing an ALI model through intraperitoneal injection of LPS, mice were treated with an EMSC-Sec spray. The lung in each group underwent an observation and measurement to preliminarily assess the extent of damage. H&E staining, immunohistochemical staining, immunofluorescence and western-blotting were utilized to further access the impacts of EMSC-Sec. The results showed that EMSC-Sec had great anti-inflammatory potential and was highly successful in vitro and in vivo. EMSC-Sec mitigated LPS-induced ALI with low inflammatory cell inflation and mild damage. EMSC-Sec could regulate inflammation via the NF-κB(p50/p65)/NLRP3 pathway. Overall, the present study demonstrated that EMSC-Sec regulated inflammation, hoping to provide a novel strategy for ALI treatment.