Study on the signaling mechanisms underlying synergistic induction of MUCSAC mucin by nontypeable Haemophilus in fluenzae and epidermal growth factor
- VernacularTitle:表皮生长因子协同上调不分型流感嗜血杆菌诱导的MUC5AC表达及其信号通路
- Author:
Yuxian HUANG
;
Wenhong ZHANG
;
Xinhua WENG
- Publication Type:Journal Article
- Keywords:
Haemophilus influenzae;
Epidermal growth factor;
MUC5AC;
Mitogen-activated protein kinases;
Signal transduction;
Mucins;
Gene-expression
- From:
Chinese Journal of Infectious Diseases
2008;26(5):263-267
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the signaling mechanisms underlying synergistic induction of MUC5AC mucin by nontypeable Haemophilus influenzae(NTHi)and epidermal growth factor (EGF).Methods The expression of MUC5AC was measured by real-time quantitative polymerase chain reaction(PCR)and Luciferase assay.Western blot was performed to examine the synergistic induction of phosphorylation of P38,extracellular signal-regulated kinase(ERK)and P21-activated kinase(PAK)4 or the effect of dominant negative mutant of PAK4 on the synerglstic induction of phosphorvlation of P38 mitogen-activated protein kinase(P38MAPK)and ERK in HM3 cells treated with NTHi and EGF.Luciferase asgay was also performed to examine the effect of P38,ERK inhibitors or dominant negative mutants of P38MAPK and ERK on synergistic enhancement of NTHi-induced MUC5AC up-regulation by EGF at transcriptional level.Real-time quantitative PCR was performed to examine the effect of PAK4 siRNA on synergistic induction of NTHi-induced MUC5AC up-regulation by EGF.ResuIts NTHi induced MUC5AC mucin expression at both mRNA and transcriptional levels.Synergistic induction of phosFIhorylation of P38MAPK,ERK and PAK4 were observed in HM3 cells treated with NTHi and EGF.Either SB203580,a specific inhibitor for P38MAPK or PD98059,a specific inhibitor for ERK inhibited synergistic induction of MUC5AC at transcription level.Furthmore, overexpressing dominant negative mutant of P38MAPK and ERK also inhibited synergistic induction of MUC5AC at transcription level. PAK4 siRNA inhibited the synergistic induction of MUC5AC by NTHi and EGF. Overexpressing dominant negative mutant of PAK4 also reduccd synergistic induction of phosphorylation of P38 and ERK. Conclusion Synergistic induction of MUC5AC mucin by NTHi is up-regulated by EGF via PAK4-dependent P38MAPK and ERK pathways.
