胰高血糖素类肽-1缓释珠对大鼠视网膜神经节细胞的保护作用

目的探讨玻璃体内植入胰高血糖素类肽-1（GLP-1）缓释珠对大鼠视网膜神经节细胞的保护作用。设计实验研究。研究对象SPF级Sprague-Dawley（SD）雄性大鼠25只。方法将25只大鼠随机分为2组，实验组13只，对照组12只。实验组大鼠右眼玻璃体内植入4个GLP-1缓释珠，对照组右眼玻璃体内注入4μl复方氯化钠。GLP-1缓释珠直径600μm，内含3000个整合了GLP-1基因的人骨髓间充质干细胞，外被致密的藻酸盐外膜，以确保GLP-1产物可顺利释放而不引起免疫排斥。玻璃体内注射均在右眼视神经夹伤后立即进行。视神经夹伤后第23天用3％荧光金从双侧上丘做逆行标记，第28天取双眼球标本做视网膜铺片并在荧光显微镜下拍摄照片，采用人工双盲法进行视网膜神经节细胞计数。主要指标视网膜神经节细胞密度以及视网膜神经节细胞存活率。结果视网膜神经节细胞密度实验组与对照组分别为（2113±474）／mm2和（1734±424）／mm2，两组之间的差异有统计学意义（t=2．111，P=-0．046）。视网膜神经节细胞存活率实验组与对照组分别为（74±18）％和（57±16）％，两组之间的差异有统计学意义（t=-2．451，P=-0．022）。结论GLP-1缓释珠玻璃体内植入后对视神经夹伤大鼠视网膜神经节细胞具有保护作用，可以提高视网膜神经节细胞存活率。

Neuroprotective effect of intravitreal glucagon-like peptide-1 production in the optic nerve crush model

Objective To examine a potentially neuroprotective effect of glucagon-like peptide-1 （GLP-1） produced locally in the eye by intraocular cell-based therapy in the optic nerve crush model. Design Experimental study. Participants 25 Spragne-Dawley rats. Methods Twenty-five Spragne-Dawley rats were divided into a study group of 13 animals receiving 4 beads （diameter： 600μm） containing 3000 ceils which were genetically encoded to produce GLP-1 and which were encoated by a highly connected hyaluronic acid layer; and a control group of 12 animals receiving an intraperitoneal saline injection. The beads implantation and the saline injection were performed immediately after the optic nerve crush was carried out. For each animal, the right optic nerve was crushed for 60 seconds by a microclip with 40g power. At day 23 after the optic nerve crush, the retinal ganglion cells were retrogradely labeled by injecting 3% fluorogold into both sides of the superior colliculus of the brain. At 4 weeks after the optic nerve crush, the animals were sacrificed. Photographs taken from retinal fiat mounts were assessed for counting the retinal ganglion cells. Main Outcome Measures Density and survival rate of the retinal ganglion cells. Results The retinal ganglion cell density of the right eyes with an optic nerve crush was higher in the study group （2113±474 cells/mm2） than that in the control group （1734±424 cells/mm2）, the difference be- tween the two groups was statistically significance （t=-2.111, P=0.046）. Correspondingly, the survival rate （ratio of retinal ganglion cell density in the right eye divided by cell density in the left eye） was statistically significantly （t=-2.451, P=0.022） higher in the study group than that in the control group （74±18% versus 57±16%）. Conclusion Glucagon-like peptide-1 produced locally by intraocular cell-based therapy is associated with a higher survival rate of retinal ganglion cells after an experimental and standardized optic nerve crush in rats.