【摘要】 【目的】为了分析Dll4、VEGFR-1、VEGFR-2在视网膜新生血管中的表达,探讨Notch1-Dll4信号通路在氧诱导视网膜病小鼠新生血管形成中的作用。【方法】选用鼠龄7 d的C57BL/6J新生鼠30只,分成实验组和对照组。实验组15只,在氧浓度为(75±2)%的密闭容器中生长5 d,回到室内正常空气中;对照组15只,在室内正常空气中生长。两组各取产后7 d(7 d post-partum,p7)、p12、p17新生鼠5只,摘除眼球,取视网膜提取RNA,以RT-PCR方法检测Dll4、VEGFR-1、VEGFR-2在视网膜中m RNA的表达。【结果】RT-PCR结果显示,在p7和p12时间点时,两组间VEGFR-1表达差异无统计学意义(P>0.05);在p17时间点时,两组间VEGFR-1表达差异有统计学意义(P<0.05),实验组表达量低于对照组;VEGFR-2在各时间位点两组间表达差异无统计学意义(P>0.05);在p7时间点时,两组间Dll4表达差异无统计学意义(P>0.05);在p12和p17时间点时,两组间Dll4表达差异有统计学意义(P<0.05,P<0.05),实验组表达量低于对照组;实验组不同时间点VEGFR-1、Dll4的表达,随着时间的延长而下降(P<0.05,P<0.05);VEGFR-2的表达,随着时间的延长而升高(P<0.05);对照组不同时间点的VEGFR-2表达随着时间延长而增加(P<0.05),而VEGFR-1和Dll4的表达均不随时间变化而变化(P>0.05,P>0.05);Dll4的表达与VEGFR-1的表达呈正相关关系,相关系数r=0.905,P<0.001;而Dll4与VEGFR-2、VEGFR-1与VEGFR-2之间不存在相关关系。【结论】Notch1-Dll4信号通路可能参与了VEGF调控视网膜新生血管生成的过程,Dll4在氧诱导视网膜病小鼠新生血管的形成中表达受到抑制,对VEGF未能进行有效负反馈调控;VEGFR-1的表达受到抑制,且与Dll4表达存在正相关关系;VEGFR-2可能不是视网膜新生血管形成过程中VEGF表达的主要受体。更多还原

【Abstract】 【Objective】 To investigate the role that Notch1-Dll4 signal pathway played in the oxygen-induced retinal neovascularization of mice by analyzing the expression of Dll4, VEGFR-1, and VEGFR-2 in retinal neovascularization. 【Methods】Thirty 7-day-old C57 BL / 6J mice were divided into oxygen-induced retinopathy group and control group. In oxygen-induced retinopathy group, 30 mice were exposed to(75 ± 2) % oxygen for 5 days and then back to room air. In control group, 15 mice were raised in room air. Five mice were taken from each group at p7(7 d post-partum), p12, and p17, respectively, and then used the retinas to extract RNA. m RNA expression of Dll4, VEGFR-1 and VEGFR-2 was detected in retinas by RT-PCR. 【Results】 There was no statistically significant differences in VEGFR-1 expression between these two groups in p7 and p12(P > 0.05). VEGFR-1expression of oxygen-induced retinopathy group was lower than the control group(P < 0.05). There was no statistically significant differences in VEGFR-2 expression between these two groups in each timing(P > 0.05). Dll4 expression between the two groups wasnearly the same in p7(P > 0.05), and the expression of oxygen-induced retinopathy group became lower in p12 and p17(P < 0.05,P < 0.05). As time went on, the expression of VEGFR-1 and Dll4 decreased in each timing(P < 0.05, P < 0.05), and that of VEGFR-2 increased(P < 0.05) in oxygen-induced retinopathy group. In control group, the expression of VEGFR-1 and Dll4 protein did not change a lot from p7 to p17(P > 0.05, P > 0.05), and that of VEGFR-2 increased(P < 0.05). It showed positive correlation between Dll4 and VEGFR-1,r = 0.905, P <0.001. There was no correlativity between Dll4 and VEGFR-2, or between VEGFR-1and VEGFR-2. 【Conclusion】 Notch1- Dll4 signaling pathway may be involved in the regulation of VEGF in the process of retinal angiogenesis. The expression of Dll4 was inhibited in oxygen-induced retinopathy mice during the formation of neovascularization, so it failed to show negative feedback regulation to VEGF. The expression of VEGFR-1 was inhibited in oxygen-induced retinopathy mice and has a positive correlation with Dll4. EGFR-2 may not be the main receptor that VEGF expressed in retinal angiogenesis process.更多还原