Divergent effects of dithiocarbamates on AP-1-containing and AP-1-less NFAT sites.
Changes in the redox status of cells affect NF-kappaB and activator protein (AP)-1 nuclear expression and activity. In particular, antioxidants decrease NF-kappaB and increase AP-1 transcriptional activity, thereby regulating gene expression. In T cells, low concentrations of antioxidants enhance IL-2 and inhibit IL-4 expression. Since NFAT binding sites play an essential role in regulating IL-2 and IL-4 gene transcription, we studied the effects of dithiocarbamates, using the pyrrolidine derivative of dithiocarbamate (PDTC), on the activity of the distinct AP-1-containing IL-2 NFAT and AP-1-less IL-4 NFAT enhancers elements. Consistent with the presence of AP-1 proteins within the IL-2 NFAT complex, PDTC strongly enhanced phorbol 12-myristate 13-acetate/phytohemagglutinin-induced NFAT binding to the IL-2 NFAT enhancer and transcriptional activity of a reporter plasmid driven by this NFAT enhancer. In contrast, the activity of the IL-4 NFp enhancer, which does not bind AP-1, was abolished by PDTC treatment. In the Jurkat T cell line treated with PDTC, co-expression of the Ca2+/calmodulin-dependent phosphatase, calcineurin, completely restored the IL-4 NFp enhancer activity. Our data indicate that calcineurin-mediated NFAT activity is a target for antioxidants and provides new insights into the molecular mechanisms controlling differential cytokine gene expression.
Saccani
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S
Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy.
Saccani
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A
Varesio
L
L
Ghosh
P
P
Young
H A
HA
Sica
A
A
D000975:Antioxidants / Q000494:pharmacology*; D019703:Calcineurin / Q000494:pharmacology; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004742:Enhancer Elements, Genetic; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D019169:Jurkat Cells; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D011759:Pyrrolidines / Q000494:pharmacology*; D013859:Thiocarbamates / Q000494:pharmacology*; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects
D000975:Antioxidants; D004268:DNA-Binding Proteins; D007376:Interleukin-2; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D011759:Pyrrolidines; D013859:Thiocarbamates; D018808:Transcription Factor AP-1; D014157:Transcription Factors; D015847:Interleukin-4; D004247:DNA; D019703:Calcineurin; C032519:pyrrolidine