Effects of A549-derived exosome on tight junction protein and cytoskeleton remodeling in lung epithelial cells BEAS-2B / 医学研究生学报

ABSTRACT

Objective A large number of studies have shown that the exosome is closely related to the occurrence and devel -opment of tumor cells , but the specific mechanism is still unknown .The study was to investigate the effects of A 549-derived exosome on tight junction protein and cytoskeleton remodeling in normal lung epithelial BEAS-2B cells. Methods A549-derived exosome were isolated by ultracentrifugation , the morphology of which was observed by transmission electron microscope .Western blot analysis was used to examine the surface markers of CD 9 and CD63.Immunofluorescence assay, western blot assay and qPCR assay were applied to detect the effects of exosome on tight junction protein ZO-1 and occludin mRNA expression in BEAS-2B cell.Phalloidin-FITC staining experiment was used to detect the effects of exosome on the cytoskeleton remodeling of BEAS-2B cells.The invasiveness of A549 to BEAS-2B was detected by Transwell invasion test . Results Typical vesicles were observed under electron microscope and exosome markers CD 9 and CD63 expression were detected.The expression levels of ZO-1, occludin pro-tain (P<0.05) and mRNA (P<0.01) were decreased in exosome-treated BEAS-2B cells, and the cytoskeleton remodelled .Transwell invasion test showed that the number of A 549 cells passing through the microporous membrane (22±4) after exosome treatment BEAS-2B was significantly higher than that of the control group (10.6±4.5) (P<0.05). Conclusion A549-derived exosome can promote the cytoskeleton remodeling of BEAS-2B cells by down-regulating the expression of ZO-1 and occludin in BEAS-2B cells, aiming to de-stroy the barrier of BEAS-2B cell to tumor cell A549.