The role of IFN-γ in regulating Nfkbiz expression in epidermal keratinocytes

Nfkbiz is an inhibitor of nuclear factor KB (IkB) protein localized to the nucleus. We previously found that Nfkbiz gene-disrupted mice showed atopic dermatitis-like lesion, implying the important role of Nfkbiz in skin homeostasis. The purpose of this study was to examine the effect of interferon (IFN)-gamma on Nfkbiz expression in keratinocytes. IFN-gamma induced Nfkbiz expression at a comparable level to IL-1. Promoter analysis revealed that interferon-stimulated response element (ISRE) located in the Nfkbiz promoter region is important for responding to the stimulation. Interestingly, IFN-gamma and IL-1 displayed synergism in terms of inducing Nfkbiz expression. By using selective inhibitors, we found that Janus activated kinase (JAK) 1 and nuclear factor (NF)-kB are important for Nfkbiz expression after IFN-gamma stimulation and for synergism between IFN-gamma and ILL These findings indicate a possible important role of Nfkbiz in modulating the progression of inflammatory diseases in which IFN-gamma and IL-1 are abundant.