Regulatory mechanism of activator protein-1 on the expression of MUC5AC induced by cigarette smoke extract.
10.3969/j.issn.1672-7347.2010.11.006
- Author:
Hongmei YU
1
;
Xiangdong ZHOU
Author Information
1. Department of Respiratory Medicine, Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China.
- Publication Type:Journal Article
- MeSH:
Bronchi;
cytology;
Cells, Cultured;
Epithelial Cells;
cytology;
metabolism;
Humans;
Mucin 5AC;
genetics;
metabolism;
Smoke;
adverse effects;
Smoking;
adverse effects;
Tobacco;
chemistry;
Transcription Factor AP-1;
pharmacology
- From:
Journal of Central South University(Medical Sciences)
2010;35(11):1150-1155
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE:To investigate the mechanism of activator protein-1 (AP-1) on cigarette smoke-induced airway mucous hypersecretion and to explore the possible signal transduction pathway that activates AP-1.
METHODS:The airway epithelial cell line (BEAS-2B) was cultured in vivo and treated with cigarette smoke extract (CSE). The DNA binding activity of AP-1 was blocked by the transfection of c-Jun dominant negative mutant TAM67 into the cells. SP600125 and PD98059 were used to block the activation of c-Jun terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) respectively. MUC5AC protein was detected by enzyme-linked immunosorbent assay, MUC5AC mRNA level was analyzed by RT-PCR, while the protein contents of p-JNK, p-ERK and p-P38 were detected by Western blot, and the DNA binding activity of AP-1 was determined by electrophoretic mobility shift assay.
RESULTS:The MUC5AC protein production and mRNA expression in the CSE group were significantly higher than those in the control group, and the DNA binding activity of AP-1 was also higher than that in the control group (P<0.01). The protein contents of p-ERK and p-JNK in the CSE group were higher than those in the control group (P<0.01), but the p-P38 level was not significantly different from that in the control group (P>0.05). After the transfection of TAM67 into the cells, the expression levels of MUC5AC protein and mRNA and the binding activity of AP-1 decreased significantly (P<0.01). The DNA binding activity of AP-1 and the expression levels of MUC5AC protein and mRNA were lower in the SP600125 group and in the PD98059 group than those in the CSE group (P<0.05).
CONCLUSION:After being activated by JNK and ERK which are phosphorylated by cigarette smoke, AP-1 binds to its DNA binding elements on the promoter of MUC5AC gene and up-regulates the MUC5AC expression at the transcriptional level.
