JNK-AP-1 pathway involved in interleukin-1beta-induced calcitonin gene-related peptide secretion in human type II alveolar epithelial cells.
In a previous study, we found that calcitonin gene-related peptide (CGRP) could be induced by proinflammatory factor IL-1beta in A549 human type II alveolar (AEII) epithelial cells. We investigated the mechanism of IL-1beta-induced CGRP secretion and found that the PKC-p38 MAPK-NF-kappaB pathway was involved. In the present study, we found that IL-1beta stimulation induced c-Jun N-terminal kinase (JNK) activity within 15min in A549 cells. In investigating whether JNK was involved in IL-1beta-induced CGRP secretion, the JNK II inhibitor SP600125 was used and it significantly attenuated IL-1beta-induced CGRP secretion and c-Jun activity, which was elevated after IL-1beta stimulation from mRNA to protein level. EMSA results showed the activation of activator protein 1 (AP-1) after 2-h IL-1beta stimulation, and the JNK II inhibitor blocked c-Jun and AP-1 activity. Bioinformatic analysis showed five predicted AP-1 binding sites on the promoter of beta-CGRP; deletion analysis identified an AP-1 consensus site at -643bp relative to the initiation site, which mediates the beta-CGRP gene transcription in response to IL-1beta. These data suggest that besides the PKC-p38 MAPK-NF-kappaB pathway, the JNK-AP-1 pathway is involved in IL-1beta-induced CGRP secretion in A549 human type II alveolar epithelial cells, and a 643-bp site upstream of the transcription start site on the promoter of beta-CGRP is the AP-1 response element.
Li
Wenjing
W
Department of Physiology and Pathophysiology, School of Basic Medical Sciences; Reference Laboratory of Education Ministry on Molecular Cardiology, Health Science Center, Peking University, Beijing 100083, PR China.
Zheng
Shuai
S
Tang
Chaoshu
C
Zhu
Yi
Y
Wang
Xian
X
D015740:Calcitonin Gene-Related Peptide / Q000032:analysis / Q000378:metabolism*; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000187:drug effects*; D006801:Humans; D053583:Interleukin-1beta / Q000494:pharmacology*; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism*; D011650:Pulmonary Alveoli / Q000166:cytology*; D011863:Radioimmunoassay; D018808:Transcription Factor AP-1 / Q000378:metabolism*
D053583:Interleukin-1beta; D018808:Transcription Factor AP-1; D048031:JNK Mitogen-Activated Protein Kinases; D015740:Calcitonin Gene-Related Peptide