环缩酚肽抑制视网膜表达VEGF及PECAM基因和血管增生

Inhibition of Gene Expression of VEGF, PECAM and Neovascularization of Retina by Cyclic Heptadepsipeptide

【目的】观察两种环缩酚肽衍生物(Hep-A和Hep-B)对氧诱导的小鼠视网膜表达血管内皮生长因子(VEGF)和细胞黏附分子(PECAM；ICAM-1；VCAM-1)基因的影响及血管增生的变化。【方法】建立氧诱导的血管增殖性视网膜病变模型，12d开始给小鼠皮下注安慰剂(第1组，n=7)、Hep-A 10 mg／kg(第2组，n=6)或者Hep-B 10 mg／kg(第3组，n=6)，每天两次。5d后取出左侧眼，分离视网膜并抽提RNA，用荧光定量PCR测出上述基因含量，并分别求出每个靶基因与标准基因S16含量的比率；右眼经心脏荧光素灌注后取眼球做视网膜平铺片，用图像分析软件定量计算视网膜新生血管的面积。【结果】视网膜中VEGF／S16的mRNA比率为：第1组(0.554±0.050)，第2组(0.355±0.037)，第3组(0.287±0.051)；PECAM／S16为：第1组(2.050±0.249)，第2组(1.228±0.153)，第3组(1.027±0.210)。经ANOVA分析，第2组和第3组分别与第1组比较，视网膜中VEGF基因表达分别减少36％和48.2％(P=0.001)；PECAM基因表达分别减少40.1％(P＜0.05)和49.9％(P＜0.01)；而VCAM-1和ICAM-1表达无明显差异。视网膜平片检测视网膜新生血管面积：第1组为(1.06±0.03)mm^2／眼，第2组为(0.17±0.01)mm^2／眼，第3组为(0.11±0.01)mm^2／眼；经ANOVA分析，第2组和第3组分别与第1组比较，视网膜新生血管的面积明显减少(P＜0.001)。【结论】两种环缩酚肽衍生物均抑制氧诱导的小鼠视网膜表达VEGF和PECAM基因，并抑制其形成视网膜新生血管。

[Objective] To investigate the effects of two novel fungus-derived cyclic heptadepsipeptide （Hep-A and Hep-B） on retinal gene expression of vascular endothelial growth factor （VEGF） and cellular adhesion molecules （PECAM, ICAM-1, and VCAM-1） and neovascularization in a mice model of oxygen-induced ischemic retinopathy. [Methods] To set up the ischemic retinopathy mice model. At 12 d the mice were put back in room air and treated with subcutaneous injection of vehicle （Group 1, n=7） 10 mg/kg Hep-A （Group 2, n=6）, 10 mg/kg Hep-B （Group 3, n=6）, or twice a day. Five days later the left eyes were nucleated, the retina was dissected and the RNA was extracted immediately then to perform the real time RT-PCR. The cDNA ratio of each above target gene/S16 （housekeeping gene） was calculated. After nucleated the left eye, the mouse was perfused with fiuorescein-dextran and the right eye was nucleated and the retinal fiat-mount was made. The areas of the retinal neovascularization was tested under microscopy and recorded by a vadio camera and frame grabber, and then quantitated by Image-Pro Plus sofeware. The data were analyzed by ANOVA software.[Results] The retinal VEGF/S16 cDNA ratios were： Group 1 （0.554±0.050）, Group 2 （0.355±0.037）, Group 3 （0.287±0.051）. The PECAM/s16 ratios were： Group 1 （2.050±0.249）, Group 2 （1.228±0.153）, Group 3 （1.027±0.210）. Compared to vehicle-treated mice, VEGF mRNA expression decreased 36% and 48.2% （P=-0.001）, PECAM mRNA expression decreased 40.1% （P〈 0.05） and 49.9% （P〈 0.01） respectively in the retina of mice treated with Hep-A or Hep-B. ICAM-land VCAM-1 gene expression did not change. The retinal neovascularization areas were： Group 1 （1.06±0.03）mm^2/eye, Group 2 （0.17±0.01）mm^2/eye, Group 3 （0.11±0.01）mm^2/ eye. The area of retinal neovascularization in Hep-A or Hep-B treated nuce was significantly reduced （P〈 0.001） compared to vehicle-treated mice.[Conclusion] The analogs of cyclic heptadepsipeptide potently inhibit VEGF, PECAM gene expression and retinal neovasctdarization in oxygen-induced ischenfic retinopathy mice.