Exosomes Produced By Cold-stimulated Bronchial Epithelial Cells Promote Expression Of Airway Remodeling-related Factors In Lung Fibroblasts

Objective The study aims to verify human bronchial epithelial cells(BEAS-2B)were able to secrete exosomes and explore the effects of exosomes induced by cold-stimulated human bronchial epithelial cells(BEAS-2B)on the expression of airway remodeling-related factors in human embryonic lung fibroblasts(HLF1).Methods In this study,exosomes were identified by transmission electron microscope(TEM)and Western blot analysis after extracted from BEAS-2B cells’ supernatant.The extracted exosomes were incubated with HLF1 cells.And according to the different exosomes,HLF1 cells were divided into the blank control group(conventional culture),the normal control group(exosomes secreted by BEAS-2B cells without intervention)and the cold stimulation group(exosomes produced by BEAS-2B cells incubated with cold temperature).The expression of fibroblast growth factors-2(FGF-2),tumor necrosis factor-alpha(TNF-α)and matrix metalloprotein-9(MMP-9)mRNA and protein were detected by Realtime-PCR and Western blot.Results The results showed that the exosomes secreted by BEAS-2B cells were round or oval structure with diameter less than 100 nm,and expressed the exosomal markers CD9,TSG101 and ALIX.The mRNA and protein expression of FGF-2,TNF-α and MMP-9 in cold stimulation group were significantly higher than those in blank control group and normal control group(all p<0.05).Conclusion This study shows that BEAS-2B cells can release exosomes.The exosomes released by BEAS-2B cells after cold stimulation can carry and transmit biological signals and induce HLF1 cells to produce airway remodeling-related factors.