中文摘要：

目的：探讨低氧诱导因子（HIF）1α在紫外线诱导血管内皮细胞生长因子（VEGF）分泌中的调节作用。方法：体外培养人永生化角质形成细胞株（HaCaT），用不同剂量的UVB辐射，在照射后不同时间收集细胞，采用ELISA方法检测上清中VEGF蛋白含量。利用Lentivectors慢病毒系统建立针对HIF1α基因HaCaT（RNAi）稳转细胞株。30mJ／cm2UVB照射siRNAHIF1α稳定HaCaT细胞组和正常HaCaT细胞组，24h上清检测VEGF的蛋白表达。结果：UVB可增强VEGF表达．并呈剂量依赖性和时间依赖性。与正常HaCaT细胞组比，siRNAHIF1α稳定HaCaT细胞组VEGF的蛋白表达量明显降低。结论：siR—NAHIF1α可以抑制UVB诱导HIF1α目的基因的表达。

英文摘要：

Objective： To determine the role of HIF1 in UV-induced expression of its target genes vascular endothelial growth factor （VEGF）. Methods： HaCaT cells were irradiated with UVB. ELISA was performed to detect VEGF protein level at different time points after treatments. HaCaT and HaCaT（HIF1 RNAi） cells （70% confluence） were starved by replacing the medium with 0.1% FBS DMEM and culturing for 24 h. The cells were irradiated with UVB（30 mJ/cm^2） and subsequently cultured for 24 h. The VEGF expressions were detected. HaCaT （HIF1 RNAi） cells were strongly attenuate VEGF levels after UVB irradiation（P 〈 0.05） when compared with HaCaT cells. Results： Compared with control groups, UVB was able to induce VEGF protein expression in a dose and time dependent manner in HaCaT cells （P 〈 0.05）. HIF1 RNAi can attenuate VEGF levels after UVB irradiation（P 〈 0.05）. Conclusion： UVB can enhance the expression of VEGF. HIF1 can attenuate VEGF levels after UVB irradiation.