摘要
目的评价脂质体介导的内皮抑素(ES)基因转移抑制缺氧诱导的小鼠视网膜新生血管的效果。探讨基因转移抑制视网膜新生血管的可行性。方法制备阳离子脂质体及PCDNA3ES复合物。选1周龄C57Bl/6N小鼠置于氧浓度为(75±2)%的氧箱中5d。回到正常环境中诱导视网膜新生血管模型。在小鼠离开氧箱的当日,向ES注射组鼠玻璃体腔注射2μl脂质体PCDNA3ES复合物;载体对照组注射等量脂质体空白载体复合物;空白对照组小鼠注射等量PBS。采用ES抗体免疫组化方法检测ES蛋白在视网膜的表达;回到正常环境中后5d,采用荧光标记的右旋糖酐血管灌注下视网膜铺片方法观察视网膜新生血管的分布;组织学切片观察比较突破视网膜内界膜的血管内皮细胞数量;透射电镜观察ES转移对视网膜超微结构的影响。结果免疫组化检查发现ES注射组小鼠玻璃体腔注射ES后24h开始有ES表达,主要位于视网膜神经纤维层细胞中,维持至少2周仍见表达;视网膜铺片观察可见空白对照组在无灌注区边缘均可见新生血管芽及荧光渗漏。ES注射组见新生血管芽明显减少;组织学检查ES注射组较其他两组突破视网膜内界膜的细胞数量减少,差异有统计学意义;ES转移后电镜下视网膜各层超微结构未见明显改变。结论采用玻璃体腔注射方法行脂质体介导的内皮抑素基因转移可以一定程度抑制缺氧诱导的小鼠视网膜新生血管生长,对视网膜无明显的毒副作用。应进一步优化转移条件以提高治疗效果。
Objective To evaluate the effect of liposome mediated plasmids encoding endostatin （ES） injected into the vitreous to inhibit experimental retinal neovascularization. Methods Cationic liposome mediated ES expression plasmid PCDNA3-ES was constructed. One-week-old C57Bl/6N mice were exposed to （75 ± 2） % oxygen for 5 days, then returned to the room air to induce retinal neovascularization. Cationic liposome mediated ES complex （2μl） was injected into the vitreous in the treatment group. PBS 2μl or liposome with carrier DNA complex were injected in the control group. The ES protein expression in the retina was tested with immunohistological methods at 1, 3, 7 and 14 days after injection. Retinal neovascularization was evaluated by angiography with injection of fluorescein dextran and quantification of neovascular proliferative retinopathy after 5 days in room air. To examine the toxicity of the liposome and plasmid PCDNA3-ES complex, the histological changes in the retina were examined by light and electron microscopy. Results ES protein was expressed in the retina 24 hours after injection. Most of them presented in the retinal ganglion layer. This could last for 2 weeks at least. Retina of the PBS-injected eyes of retinal neovascular animal model showed prominent neovascular tuft and fluorescein leakage. Fewer neovascular tufts could be seen after ES injection. Retinal neovascularization in the eyes injected with ES plasmids complex was reduced as compared with the control group. No side effect on the retina was observed by light and electron microscopy. Conclusions Liposome mediated plasmids encoding ES can be transferred to retinal cells by vitreous injection and can suppress retinal neovascularization, no side or toxic effects are presented in the retina. Further studies should be done to improve the treatment results.
出处
《中华眼科杂志》
CAS
CSCD
北大核心
2006年第2期111-115,共5页
Chinese Journal of Ophthalmology
基金
山东省医学科学院科研基金资助项目(021114)
