Erythromycin inhibits transcriptional activation of NF-kappaB, but not NFAT, through calcineurin-independent signaling in T cells.
The molecular mechanism of the anti-inflammatory effect of erythromycin (EM) was investigated at the level of transcriptional regulation of cytokine gene expression in T cells. EM (>10(-6) M) significantly inhibited interleukin-8 (IL-8) expression but not IL-2 expression from T cells induced with 20 ng of phorbol 12-myristate 13-acetate (PMA) per ml plus 2 microM calcium ionophore (P-I). In electrophoretic mobility shift assays EM at 10(-7) to 10(-5) M concentrations inhibited nuclear factor kappa B (NF-kappaB) DNA-binding activities induced by P-I. Reporter gene assays also showed that EM (10(-5) M) inhibited IL-8 NF-kappaB transcription by 37%. The inhibitory effects of EM on transcriptional activation of IL-2 and DNA-binding activity of nuclear factor of activated T cells (NFAT) were not seen in T cells. On the other hand, FK506, which is also a macrolide derivative, inhibited transcriptional activation of both NF-kappaB and NFAT more strongly than EM did. The mechanism of EM inhibition of transactivation of NF-kappaB was further investigated in transiently transfected T cells that express calcineurin A and B subunits. Expression of calcineurin did not render transactivation of NF-kappaB in T cells more resistant to EM, while the inhibitory effect of FK506 on transactivation of NF-kappaB was attenuated. These findings indicate that EM is capable of inhibiting expression of the IL-8 gene in T cells through transcriptional inhibition and that this inhibition is mediated through a non-calcineurin-dependent signaling event in T lymphocytes.
Aoki
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Y
Division of Pulmonary and Critical Care Medicine, Stanford University Medical Center, Stanford, California 94305, USA. aokiy3@smsnet.saga-med.ac.jp
Kao
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PN
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D019703:Calcineurin / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics*; D015536:Down-Regulation / Q000187:drug effects; D004917:Erythromycin / Q000494:pharmacology*; D017930:Genes, Reporter / Q000235:genetics; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology; D019169:Jurkat Cells; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics*; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D015398:Signal Transduction / Q000187:drug effects*; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D016559:Tacrolimus / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics*; D015533:Transcriptional Activation / Q000187:drug effects*; D014162:Transfection / Q000235:genetics
D000900:Anti-Bacterial Agents; D004268:DNA-Binding Proteins; D007166:Immunosuppressive Agents; D016328:NF-kappa B; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D014157:Transcription Factors; D004917:Erythromycin; D008156:Luciferases; D019703:Calcineurin; D016559:Tacrolimus