【摘要】 目的:探讨中波紫外线(UVB)增强血管内皮生长因子(VEGF)分泌的信号途径。方法:采用流式细胞仪检测表皮生长因子受体(EGFR)和磷酸化EGFR表达。ELISA检测上清液中VEGF水平。结果:UVB照射后15min可以检测到磷酸化EGFR表达,30min时达最高峰,1h开始下降,2～8h降至基础水平,而EGFR表达量不变。UVB(30mJ/cm2)分别照射EGFR+/-、EGFR+/+和EGFR-/-小鼠胚胎成纤维细胞(MEF),结果显示EGFR+/+MEF组VEGF分泌明显高于EGFR+/-MEF组和EGFR-/-MEF组,U-VB对EGFR-/-MEF的VEGF分泌促进作用不明显。EGFR磷酸化酶抑制因子PD153035可明显抑制VEGF分泌,1μmol/L有抑制作用,5μmol/L抑制作用增强。磷脂酰肌醇3激酶(PI3K)高度选择性抑制剂LY294002及不可逆抑制剂wortmannin均可明显抑制VEGF分泌。结论:紫外线通过EGFR-PI3K-蛋白激酶(AKT)途径增强VEGF分泌。更多还原

【Abstract】 Objective: To explore pathway of UV-induced VEGF secretion of mouse embryonic fibroblast (MEF). Methods: Flow cytometry was used to detect the expression of total EGFR receptor and tyrosine-phosphorylated EGFR respectively. The VEGF concentration was determined by ELISA. Results: EGFR phosphorylation was detectable within 15 minutes after UV exposure. It peaked at 30 minutes, EGFR phosphorylation decreased to near basal levels between 2 and 8 hours after UV exposure. The EGFR-/- MEF was not capable of increasing VEGF expression following UVB irradiation. In contrast, EGFR+/+ MEF was strongly enhanced VEGF expression after UVB irradiation. PD153035, a selective inhibitor of EGFR tyrosine kinase activity, also inhibited the induction of VEGF protein expression in UVB-treated cells in a dose-dependent manner. LY294002 and wortmannin both inhibited the induction of VEGF protein expression in UVB-treated cells in a dose-dependent manner. Conclusion: UV stimulates the expression of VEGF by the way of EGFR-PI3K-AKT.更多还原