类表皮生长因子域7与动脉粥样硬化斑块内血管生成关系

目的 研究类表皮生长因子域7( Egfl7)在动脉粥样硬化斑块内的表达水平和小分子干扰RNA(siRNA)对内皮细胞株血管生长因子表达的影响. 方法 利用免疫组化和免疫荧光染色检测人髂动脉和小鼠无名动脉粥样硬化斑块内Egfl7的表达水平；并利用以Egfl7为靶标的siRNA,通过脂质体将siRNA转入人脐静脉内皮细胞株(HUVEC),以未转染siRNA细胞和转染无关siRNA细胞为对照,在干扰后0h,12 h,24 h,48 h,反转录聚合酶链反应(PT-PCR)检测Egfl7、血管内皮生长因子(VEGF)、血小板衍生生长因子A、B(PDGF-A、PDGF-B) mRNA水平的改变,免疫印迹法检测Egfl7、VEGF、PDGF、血管细胞黏附分子(VCAM)及细胞间黏附分子(ICAM)蛋白表达水平的变化.结果 人髂动脉和小鼠无名动脉粥样硬化斑块内Egfl7表达水平上调；HUVEC内Egfl7在siRNA干扰后0h、12 h、24 h、48 h时mRNA表达分别为(0.31±0.05)、(0.14±0.02)、(0.09±0.01)、(0.02±0.01),蛋白表达为(0.93±0.08)、(0.71±0.11)、(0.39±0.09)、(0.07±0.01).Egfl7、VEGF、PDGF-A、PDGF-B mRNA及其蛋白表达水平随干扰时间延长均下降或抑制,与siRNA干扰0h比较差异有统计学意义(均P＜0.05). 结论 动脉粥样硬化斑块内Egfl7表达水平提高；siRNA抑制HUVEC Egfl7表达水平的同时,其他血管生长因子和黏附分子表达水平亦下降.

Relationship between epidermal growth factor-like domain 7 and angiogenesis in atherosclerotic plaques

Objective To evaluate the expression of epidermal growth factor-like domain 7 (Egfl7) in atherosclerotic plaques and effects of its small interference RNA (siRNA) on angiogenesis gene expression in human endothelial cell line (HUVEC). Methods Egfl7 expression in atherosclerotic plaques were detected in human iliac artery and mouse arteriae using immunohistochemistry and immunofluorescence stainings.The siRNA targeting Egfl7 was transfected into HUVEC by lipofectamine with non-transfected cells and unconcerned siRNA as controls.At 0 h,12 h,24 h and 48 h after intervention,the levels of mRNA and protein of Egf17,vascular endothelial growth factor(VEGF),platelet derived growth factor-A (PDGF-A),platelet derived growth factor-B (PDGF-B),vascular cell adhesion molecule(VCAM) and intercellular adhesion molecule (ICAM)were measured by RT-PCR and Western blotting,respectively. Results The expressions of Egfl7 in human iliac artery and mouse arteriae were increased.The expressions of Egfl7 in HUVEC at the levels of mRNA were[(0.14±0.02),(0.09±0.01),(0.02±0.01)]and the levels of protein[(0.71±0.11),(0.39±0.09),(0.07±0.01)]at 12 h,24 h and 48 h after siRNA intervention,respectively,which were decreased as compared with 0 h intervention [(0.31 ±0.05) and (0.93±0.08) ].Other genes such as VEGF,PDGF-A and PDGF-B were reduced or silenced at the levels of protein and mRNA in HUVEC with siRNA longer interventions(all P＜0.05). Conclusions The expression of Egfl7 in atherosclerotic plaques is increased.The siRNA inhibiting Egfl7 gene expression results in silence of other factors involved in angiogenesis.