中波紫外线照射对人原代角质形成细胞XPA和ERCC1蛋白表达的影响以及EGCG的干预作用

Effects of UVB irradiation on protein expressions of XPA and ERCC1 in human primary keratinocytes and intervention of EGCG

目的:研究中波紫外线(UVB)照射对人原代角质形成细胞(KC)的着色性干皮病A组蛋白(XPA)和切除修复互补交叉蛋白1(ERCC1)蛋白表达的影响以及没食子儿茶素没食子酸酯(EGCG)的干预作用。方法:以一定剂量UVB照射人原代角质形成细胞,在UVB辐射前后加入EGCG干预处理细胞,用Westernblot方法检测照射后不同时间点的XPA和ERCC1蛋白的表达水平;同时检测不同剂量UVB照射后以及EGCG干预的同一时点XPA和ERCC1蛋白的表达水平。结果:30mJ/cm2的UVB照射后人原代角质形成细胞的XPA和ERCC1蛋白表达逐渐增加,4h达到峰值,后逐渐恢复至UVB照射后24h接近正常值;不同剂量UVB照射4h后,XPA和ERCC1蛋白表达随UVB剂量增大而增加。EGCG可下调UVB诱导的XPA和ERCC1蛋白表达。结论:人原代KC中XPA和ERCC1蛋白表达与UVB辐射存在一定的时间和剂量关系,EGCG可在一定程度上下调上述蛋白表达。

Objective To investigate the effects of UVB irradiation and intervention of EGCG on protein expression levels of XPA （xeroderma pigmentosum group A） and ERCC1 （Excision Repair Cross Complementing）in human primary keratinocytes, Methods Human primary KC were irradiated with various doses of UVB and treated with EGCG . Western blot assay was used to measure protein expression levels of XPA and ERCC1 at different time spots. Results Protein expression levels of XPA and ERCC1 after UVB irradiation gradually increased and reached the peak at the 4 hours. And the protein level deceased to normal level at 24 hours. Inhibitory effect of EGCG against UVB radiationinduced XPA and ERCC1 expression can be observed. Conclusion Protein expression of XPA and ERCC1 induced by UVB irradiation were time-dependent and dosage-dependent in human primary KC. EGCG can inhibit the changes of XPA and ERCC1 expression and have photo-protective effect.