中文摘要：

目的 探讨中波紫外线（UVB）辐射对表皮角质形成细胞核因子κB（NF—κB）转录活性的影响。方法 正常人表皮角质形成细胞取自健康儿童包皮，并培养于37℃、5％CO2的培养箱中；以20、60和120mJ／cm^2UVB辐射培养细胞；分别提取UVB辐射0、2、24和48h后角质形成细胞的全细胞蛋白、核蛋白和胞浆蛋白；免疫印迹方法检测分析全细胞蛋白和核蛋白的NF—κB／p65以及胞浆蛋白NF—κB抑制物（IκB—a）的动态变化：电泳迁移率变更分析（EMSA）方法检测分析NF—κB的转录活性。结果 UVB辐射可湿著促进角质形成细胞总蛋白和核蛋白中NF—κB的蛋白表达（P〈0．05），且表达量与辐射剂量成正比，UVB辐射后2h即可有NF—κB的蛋白表达水平的升高，24h后达高峰并持续高水平表达至48h；不同剂量UVB辐射角质形成细胞后的不同时间，均可促进NF—κB转录活性；UVB辐射可显著抑制角质形成细胞胞浆IκB—a蛋白的表达（P〈0．05）。结论 UVB辐射可显著促进角质形成细胞NF—κB的转录活性。

英文摘要：

Objective To study the effect of ultraviolet B （ UVB ） irradiation on the transcriptional activity of nuclear factor KB （ NF-κB ） in human epidermal keratinocytes. Methods Normal human epidermal keratinocytes were isolated from healthy children foreskin and cultured at 37℃ in 5% CO2. Cultured keratinocytes were irradiated with UVB at the dose of 20, 60 and 120 mJ/cm^2, respectively. The whole cell, nuclear and cytoplasmic protein of keratinocytes was extracted at 0, 2, 24, and 48 hours after the irradiation. The whole cell and nuclear NF-κB/p65 protein as well as cytoplasmic NF-κB Inhibitor （ IκB-a ） protein were detected by Western blotting. The transcriptional activity of NF-κB was analyzed by electrophoretic mobility shift assay （ EMSA ）. Resttlts UVB irradiation significantly increased （ P 〈 0.05 ） the protein expression of NF-κB in both the whole cell and the nucleus of keratinocytes in a dose-dependent manner; the increase began at 2 h, peaked at 24 h, and maintained with high expression until 48 h after the irradiation. The transcriptional activity of NF-KB was improved at different time points after UVB irradiation of different doses, while the expression of IκB-a was significantly decreased （ P 〈 0.05 ） by the irradiation. Conclusion UVB irradiation can improve the transcriptional activity of keratinocytes, likely by the degradation of IκB-a.