title: Activation of eotaxin-3/CCLl26 gene expression in human dermal fibroblasts is mediated by STAT6.
abstract: Allergic inflammatory conditions such as asthma are characterized by an accumulation of eosinophils at sites of inflammation. Eotaxin-3/CCL26 is a member of the family of CC chemokines, which are known to be potent chemoattractants for eosinophils. This chemokine was shown to be up-regulated by IL-4 and IL-13 in endothelial cells. This study demonstrates that eotaxin-3 transcription and eotaxin-3 protein expression are stimulated by IL-4 and IL-13 in a time- and dose-dependent fashion in human dermal fibroblasts. In contrast to eotaxin-1/CCL11, TNF-alpha could not act as inducer on its own nor did it synergize with IL-4. The activities of eotaxin-3 promoter luciferase constructs were significantly increased by IL-4 and IL-13 in human dermal fibroblasts. This effect was mediated by a binding site for the transcription factor STAT6 in the eotaxin-3 promoter sequence. Mutations in the STAT6 binding site abrogated up-regulation of eotaxin-3 promoter activity. In STAT6-defective human embryonic kidney 293 cells, the wild-type luciferase construct, but not the STAT6 binding mutant, was inducible by IL-4 only upon cotransfection of STAT6 expression vector. In addition, eotaxin-3 protein was detectable in the supernatants of STAT6-transfected human embryonic kidney 293 cells upon IL-4 or IL-13 stimulation. In the same experiments, TNF-alpha induced activation of the monocyte chemoattractant protein-1/CCL2 gene was independent of STAT6 transfection. These results indicate that IL-4 and IL-13 activate eotaxin-3 gene expression in a STAT6-dependent fashion. Although both eotaxin-1 and -3 are regulated by this transcription factor, the response of the eotaxin-3 gene to TNF-alpha stimulation appears to be different.
authors.affiliation: Department of Allergic Diseases, Novartis Research Institute, Vienna, Austria.
authors.forename: J
authors.initials: J
authors.lastname: Hoeck
authors.forename: M
authors.initials: M
authors.lastname: Woisetschläger
mesh_terms: D001665:Binding Sites; D002478:Cells, Cultured / Q000378:metabolism; D054413:Chemokine CCL11; D018932:Chemokine CCL2 / Q000096:biosynthesis / Q000235:genetics; D000075906:Chemokine CCL26; D019742:Chemokines, CC / Q000096:biosynthesis* / Q000235:genetics; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D017930:Genes, Reporter; D006801:Humans; D018793:Interleukin-13 / Q000494:pharmacology; D015847:Interleukin-4 / Q000494:pharmacology; D007668:Kidney; D008156:Luciferases / Q000096:biosynthesis / Q000235:genetics; D009928:Organ Specificity; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000096:biosynthesis; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050800:STAT6 Transcription Factor; D012867:Skin / Q000166:cytology* / Q000378:metabolism; D018418:Th2 Cells / Q000276:immunology / Q000378:metabolism; D015534:Trans-Activators / Q000502:physiology*; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: C515456:CCL11 protein, human; C120429:CCL26 protein, human; D054413:Chemokine CCL11; D018932:Chemokine CCL2; D000075906:Chemokine CCL26; D019742:Chemokines, CC; D016207:Cytokines; D018793:Interleukin-13; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D050800:STAT6 Transcription Factor; C494101:STAT6 protein, human; D015534:Trans-Activators; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4; D008156:Luciferases