The Effect Of Bombesin Receptor Activated Protein On Mucous Hypersecretion Induced By Lipopolysaccharide In Human Airway Epithelial Cells

Objective:To investigate the effect of bombesin receptor activated protein(BRAP)on lipopolysaccharide(LPS)-induced mucous hypersecretion in airway and mechanism.Methods:After cultivating HBE16 cells in vitro,the constructed p-EGFP-N1-BRAP eukaryotic vector was transfected into the cells,with empty plasmid as a vector control.At the same time in order to LPS as a stimulus and reactive oxygen species(ROS)scavenger DMTU and extracellular signal-regulated protein kinase(ERK)specific inhibitor U0126 for the intervention factors.Ten groups were conducted: the control group,the LPS group,the LPS plus pEGFP-N1-BRAP group,the LPS plus p EGFP-N1 group,the DMTU plus LPS group,the DMTU plus LPS plus p EGFP-N1-BRAP group,the DMTU plus LPS plus pEGFP-N1 group,U0126 plus LPS group,the U0126 plus LPS plus pEGFP-N1-BRAP group,the U0126 plus LPS plus pEGFP-N1 group.The cell vitality was detected by MTT.Levels of MUC5 AC mRNA and protein expression were respectively measured by RT-PCR and ELISA.The expression of BRAP,p-ERK,p-p38 MAPK and p-I? B? protein were measured by western blotting.The content of ROS was evaluated.The expression of MUC5 AC protein in 16 HBE cells was detected by confocal laser scanning microscopy.Results:(1)Compared with control group,the levels of MUC5 AC mRNA and protein expression were significantly increased in LPS stimulated group.The content of ROS production,the expression of IL-1? and IL-6,and the expression of p-ERK,p-p38 MAPK and p-I?B? protein were enhanced by LPS stimulation.(2)The up-regulation of BRAP by pEGFP-N1-BRAP caused a significant decrease in the increased levels of MUC5 AC expression.And the level of ROS and inflammation factor(IL-1? and IL-6)were remarkably reduced.Meanwhile,there was a significant decrease in the expression of p-ERK and p-I? B? induced by LPS.(3)In U0126 plus LPS plus pEGFP-N1-BRAP group,the expression of MUC5 AC,and the expression of p-ERK and p-I? B? were significantly decreased when compared with U0126 plus LPS group and U0126 plus LPS plus pEGFP-N1 group.(4)In DMTU plus LPS plus p EGFP-N1-BRAP group,the expression of MUC5 AC,ROS production,and the expression of p-ERK and p-I? B? were significantly decreased when compared with DMTU plus LPS group and DMTU plus LPS plus pEGFP-N1 group.Conclusions:BRAP overexpression could attenuate LPS-induced mucin5 AC hypersecretion via inhibiting ROS/ERK/ NF-? B signaling pathway.