Up-regulation of interleukin-4 production via NF-AT/AP-1 activation in T cells by biochanin A, a phytoestrogen and its metabolites.
Phytoestrogens are naturally occurring compounds derived from plants. Although phytoestrogens exhibit many biological functions including estrogen agonist/antagonist properties, the effect on allergic responses remains unclear. In this study, we investigated whether biochanin A, a phytoestrogen and its metabolites, genistein, p-ethylphenol and phenolic acid, affect production of IL-4, a pro-inflammatory cytokine closely associated with allergic immune responses, in primary CD4(+) T cells and EL4 T lymphoma cells. Biochanin A, genistein and p-ethylphenol significantly enhanced IL-4 production from both CD4(+) T cells and EL4 cells in a dose-dependent manner, while phenolic acid did not. Biochanin A, genistein and p-ethylphenol also enhanced IL-4 gene promoter activity in EL4 cells transiently transfected with IL-4 promoter constructs, but this effect was impaired in EL4 cells transfected with an IL-4 promoter construct deleted of a P4 site carrying NF-AT and AP-1 binding sites. In addition, biochanin A, genistein and p-ethylphenol increased both NF-AT and AP-1 DNA binding activities, indicating that they might enhance IL-4 production via NF-AT/AP-1 activation. Furthermore, biochanin A, genistein and p-ethylphenol increased p38 MAPK phosphorylation and PKC activity, while they did not affect ERK phosphorylation. The enhanced NF-AT DNA binding activities were suppressed by inhibitors for PI3-K and PKC, but not by p38 MAPK inhibitors. In contrast, the enhanced AP-1 DNA binding activities and p38 MAPK phosphorylation were significantly suppressed by specific inhibitors for PKC and p38 MAPK, but not by PI3-K inhibitors. These results demonstrate, for the first time, that biochanin A, genistein and p-ethylphenol enhance IL-4 production in activated T cells by two independent pathways, PI3-K/PKC/NF-AT and PKC/p38 MAPK/AP-1.
Park
Jin
J
School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea.
Chung
Su Wol
SW
Kim
Seung Hyun
SH
Kim
Tae Sung
TS
D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D045744:Cell Line, Tumor; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019833:Genistein / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D015847:Interleukin-4 / Q000235:genetics / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000187:drug effects* / Q000276:immunology; D008223:Lymphoma / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D050778:NFATC Transcription Factors / Q000235:genetics / Q000378:metabolism*; D010636:Phenols / Q000494:pharmacology; D010766:Phosphorylation; D048789:Phytoestrogens / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D015854:Up-Regulation; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D050778:NFATC Transcription Factors; D010636:Phenols; D048789:Phytoestrogens; D012333:RNA, Messenger; D018808:Transcription Factor AP-1; D015847:Interleukin-4; D004247:DNA; C042291:4-ethylphenol; D019833:Genistein; D048051:p38 Mitogen-Activated Protein Kinases; C004541:biochanin A