title: Suppression of IL-2 and IL-4 gene expression by nodularin through the reduced NF-AT binding activity.
abstract: Nodularin is a cyclic peptide produced by cyanobacteria. In the present study, the inhibitory effect of nodularin on T lymphocyte functions was demonstrated. Direct addition of nodularin to B6C3F1 mouse splenocyte cultures produced a concentration-dependent inhibition of the lymphoproliferative response to concanavalin A stimulation. Nodularin inhibited PMA plus ionomycin (Io)-induced IL-2 mRNA expression in murine splenocytes and thymocytes as determined by quantitative/competitive RT-PCR. To further characterize the mechanism for the transcriptional regulation of IL-2, the binding activity of transcription factors, NF-AT, AP-1, NF-kappaB, and Oct, was evaluated by electrophoretic mobility shift assays in mouse splenocytes. Nodularin reduced the NF-AT binding activity in PMA/Io-induced splenocytes, but no significant effect was observed on AP-1, NF-kappaB, or Oct binding activity. Nodularin also inhibited IL-4 mRNA expression in PMA/Io-stimulated murine splenocytes. These results suggest that T lymphocyte is a possible cellular target of nodularin, and the inhibitory effect of nodularin on T-cell specific transcription factor NF-AT induces T-cell dysfunction, which leads to a diminution in IL-2 and IL-4 gene transcription.
authors.affiliation: Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Yusung-Gu, Taejon, South Korea.
authors.forename: S S
authors.initials: SS
authors.lastname: Yea
authors.forename: H M
authors.initials: HM
authors.lastname: Kim
authors.forename: Y J
authors.initials: YJ
authors.lastname: Jeon
authors.forename: H M
authors.initials: HM
authors.lastname: Oh
authors.forename: H G
authors.initials: HG
authors.lastname: Jeong
authors.forename: K H
authors.initials: KH
authors.lastname: Yang
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology*; D001667:Binding, Competitive / Q000187:drug effects; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D051863:Host Cell Factor C1; D007376:Interleukin-2 / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D015847:Interleukin-4 / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D015759:Ionomycin / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D050811:Octamer Transcription Factor-1; D010456:Peptides, Cyclic / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013950:Thymus Gland / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D001427:Bacterial Toxins; D004268:DNA-Binding Proteins; C497693:Hcfc1 protein, mouse; D051863:Host Cell Factor C1; D007376:Interleukin-2; D016328:NF-kappa B; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D050811:Octamer Transcription Factor-1; D010456:Peptides, Cyclic; C494166:Pou2f1 protein, mouse; D012333:RNA, Messenger; D018808:Transcription Factor AP-1; D014157:Transcription Factors; C063998:nodularin; D003208:Concanavalin A; D015847:Interleukin-4; D015759:Ionomycin; D013755:Tetradecanoylphorbol Acetate