JNK-dependent NFATc1 pathway positively regulates IL-13 gene expression induced by (-)-epigallocatechin-3-gallate in human basophilic KU812 cells.
(-)-Epigallocatechin-3-gallate (EGCG) has been reported to possess a wide range of biological and pharmacological properties. In this study, we investigated the effects of EGCG on IL-13 gene expression in human basophilic KU812 cells. The IL-13 mRNA expression level was dose-dependently increased by treatment with EGCG (5-20 microM) for 1 h and additional incubation in a medium for 23 h. EGCG significantly increased the intracellular peroxide level as detected by the peroxide-sensitive probe 2',7'-dichlorodihydrofluorescein diacetate. A pharmacological experiment using catalase and a structure-activity relationship study revealed that the exogenously produced H(2)O(2) significantly, but partially, contributed to the IL-13 expression as well as the intracellular oxidative status. Furthermore, EGCG at the concentration required for IL-13 up-regulation activated c-Jun NH(2)-terminal kinase (JNK), but not extracellular signal-regulated protein kinase or p38 mitogen-activated protein kinase in KU812 cells. Transfection of a JNK-specific siRNA as well as treatment with a JNK-specific inhibitor, SP600125, significantly reduced the EGCG-induced IL-13 mRNA expression, by 47.1 and 44.6%, respectively. In addition, we observed the nuclear translocation, mRNA up-regulation, and activation of DNA binding with the IL-13 promoter of nuclear factor of activated T cells (NFATc1) in the EGCG-treated cells. These data provide biological evidence that EGCG induces IL-13 mRNA expression via the JNK-dependent NFATc1 pathway in KU812 cells.
Wu
Haitao
H
Department of Biofunctional Chemistry, Division of Bioscience, Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan.
Qi
Hang
H
Iwasaki
Dai
D
Zhu
Beiwei
B
Shimoishi
Yasuaki
Y
Murata
Yoshiyuki
Y
Nakamura
Yoshimasa
Y
D000873:Anthracenes / Q000494:pharmacology; D001491:Basophils / Q000187:drug effects* / Q000378:metabolism; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D018793:Interleukin-13 / Q000096:biosynthesis / Q000235:genetics*; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D050778:NFATC Transcription Factors / Q000378:metabolism*; D010545:Peroxides / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013329:Structure-Activity Relationship; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics
D000873:Anthracenes; D018793:Interleukin-13; D050778:NFATC Transcription Factors; C494003:NFATC1 protein, human; D010545:Peroxides; D012333:RNA, Messenger; C432165:pyrazolanthrone; D002392:Catechin; D006861:Hydrogen Peroxide; C045651:epigallocatechin gallate; D048031:JNK Mitogen-Activated Protein Kinases