کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2831278 | 1570733 | 2012 | 7 صفحه PDF | دانلود رایگان |
Atopic dermatitis (AD), a chronic, pruritic, inflammatory skin disease, is histopathologically characterized by epidermal hyperplasia and infiltration of T cells, mast cells, and eosinophils. Clinical study and basic research have established that IL-4 plays an important role in the pathogenesis of AD. In this report, using HaCat cells, we show that CCL26, a chemokine for eosinophils, is up-regulated by IL-4 at both the mRNA and protein levels. IL-4 also enhances CCL26 promoter activity. Serial 5′ deletion of the promoter and mutagenesis study reveal that the proximal Stat site is the key response element for IL-4 regulation of CCL26. Although IL-4 increases phosphorylation of both Stat3 and Stat6, it only activates Stat6 as shown by dominant negative studies. In addition, we found that IL-4 induces Stat6 nuclear translocation and stimulates phosphorylation of Jak1 and Jak2 but not Tyk2. IL-4 up-regulation of CCL26 can be suppressed by Jak inhibitors in a dose-dependent manner. Taken together, results of this investigation reveal that IL-4 signals through the Jak1, 2/Stat6 pathway in keratinocytes to stimulate CCL26 expression and this may provide an explanation for the pathogenesis of AD.
► We described the detailed signal pathway for IL-4 regulation of CCL26 in keratinocytes.
► The IL-4 response element was identified in the CCL26 promoter.
► With both Stat3 and Stat6 phosphorylated by IL-4, only Stat6 is functionally active.
► Both Jak1 and Jak2 are involved in the IL-4 up-regulation of CCL26.
Journal: Molecular Immunology - Volume 50, Issues 1–2, February 2012, Pages 91–97