The Effect of UVB on the NF-kB and AP-1 Activity in Cultured Human Keratinocytes and Fibroblasts / 대한피부과학회지

ABSTRACT

BACKGROUND: Ultraviolet B(UVB) light, which can cause severe damage like induction and promotion of cancer, cutaneous inflammation and immunosuppression, represents one of the most important environmental impacts for humans. Keratinocytes are natural target cells of UVB in humans. NF-kB plays a role in the cell of the immune system, where it controls the expression of various cytokines and the major histocompatibility complex gene. OBJECTIVE: The purpose of this study was to examine the effect of UVB on the NF-kB and AP-1 activity in cultured human keratinocytes and fibroblasts. METHODS: Keratinocyte and fibroblast cultures were produced with DMEM medium. Cells were irradiated for 100J/m, 200J/m, 300 J/m. and Nuclear proteins were extracted. AP-1 and NF-kB activities were measured by the gel shift mobility assay. RESULTS: Gel shift mobility assay. 1. The NFkB activity was increased upon UVB in a dose dependent manner in the keratinocyte. 2. Enhanced levels of AP-1 binding activity in the radiated extracts frorn human skin keratinocytes were detected. 3. The levels of GRE (glucocorticoid responsive element) binding activity were similar in both radiated and unradiated extracts from fibroblasts and keratinocytes. CONCLUSIONS: The activities of NF-aB and AP-1 are increased following stimulation of a cell with UVB irradiation. Therefore, UV induced skin tumors, abnormal cell proliferation, cutaneous inflammation and immunosuppression, may be due to these transcriptional factors.