Abstract: Objective To investigate the effect of Elafin in cytoplasm on epidermal growth factor(EGF)-induced mucin(MUC)5AC production and the mechamism of it. Methods After cultivating 16HBE cells in vitro, the constructed pEGFP-N1-Elafin eukaryotic expression vector was transfected into the 16HBE cells by LipofectamineTM2000,and 16HBE cells transfected the vector without Elafin gene as control group. The cells were then incubated with exogenous EGF.The mucin(MUC)5AC mRNA level was analyzed by RT-PCR,the MUC5AC protein production was assayed by ELISA,the NF-κB activity in nuclear was detected by immunofluorescence and laser scanning confocal microscope,the SUMO-1-p-IκBα production was assayed by co-immunoprecipitation(CO-IP) and Western blot. Results The MUC5AC mRNA level,the MUC5AC protein production(0.36±0.09) and the NF-κB activity of the experimental group were all significantly lower than those of the empty vector group(MUC5AC production of the later is 0.55±0.07),but the SUMO-1-p-IκBα production was significantly higher than that of the latter(all P﹤0.01). Conclusions Elafin prevents NF–κB activation via an effect on p-IκBα sumoylation,thus reducing epidermal growth factor-induced mucin5AC production.

Key words: Elafin, Nucleat factor-κb, Small ubiquitin-like modifier -1, Sumoylation, Mucin5AC