Analysis of intraretinal neuro-glial interaction in glaucoma

1.为探讨糖尿病对青光眼视神经病变的影响，采用链脲佐菌素（STZ）致糖尿病大鼠模型，通过巩膜外静脉烧灼法造成大鼠单侧眼慢性眼压升高。对在几个处死时间点解剖的平贴视网膜进行末端dUTP缺口末端标记（TUNEL）染色。视网膜内层TUNEL阳性细胞数在糖尿病视网膜行巩膜上静脉电灼组明显高于对照组。因此，糖尿病对青光眼诱导的大鼠神经细胞凋亡具有累加效应。2.为了确定促存活Akt通路在慢性高眼压大鼠视网膜中是否被激活，对大鼠上巩膜静脉曲张的大鼠视网膜进行了冰冻切片和全视网膜的荧光染色以及视网膜匀浆的免疫印迹。 ...更多信息 在烧灼术中。Akt磷酸化丝氨酸437特异性表达在视网膜神经节细胞在视网膜烧灼，但不是在对侧视网膜。视网膜电灼后磷酸化Akt相对于总Akt显著增加。因此，Akt激活可能抵消视网膜中增加的IOP应激。3.最后，为了测试在青光眼视网膜中胶质反应性是否改变，在与2中相同的实验性青光眼模型中进行胶质纤维酸性蛋白（GFAP）的免疫染色和免疫印迹。早在巩膜外静脉烧灼后3天，星形胶质细胞丢失，Muller细胞获得GFAP免疫反应性，随时间推移部分逆转，但持续长达6个月。GFAP分子的流动性和酸性也被烧灼改变。在1个月及之后的对侧视网膜中也发生了类似的观察结果。因此，巩膜上静脉烧灼不仅改变了大鼠同侧眼的神经胶质反应性，也改变了对侧眼的神经胶质反应性。少

1.In an attempt to elucidate the causal effect of diabetes on development of glaucomatous optic neuropathy, male Sprague-Dawley rats were made diabetic by streptozotocin injection, in which unilateral eyes were treated with episcleral vein cauterization to produce chronically elevated intraocular pressure (IOP). Terminal dUTP nick end-labeling (TUNEL) staining was performed on the flat-mount retina dissected at several time points of sacrifice. The number of TUNEL positive cells in the inner retina was significantly higher in diabetic retina with episcleral vein 'cauterization than in control retina with same operation. Thus, diabetes has an additive effect on neuronal apoptosis induced by glaucoma in rats.2.In order to identify whether the pro-survival Akt pathway is activated in retina with chronically elevated IOP, immunohistochmeistry in the crysosection and in the whole mount retina as well as immunoblotting with retinal homogenates were conducted for rat retina with episcleral ve … More in cauterization. Akt phorphorylated at Ser 437 was specifically expressed in the retinal ganglion cells in the retina with cauterization, but not in the contralateral retina. Phosphorylated relative to total Akt was significantly increased in retina with cauterization. Thus, Akt activation may counteract against increased IOP stress in retina.3.Finally, to test whether glial reactivity was altered in glaucomatous retina, immunostaining and immunoblotting for glial fibrially acidic protein (GFAP) was conducted in the same experimental glaucoma model as in 2. Astrocytes lost and Muller cells gained GFAP imunoreactivity as early as at 3 days after episcleral vein cauterization, which was partially reversed overtime but last up to 6 months. GFAP molecular mobility and acidity were also changed by the cauterization. Similar observations were also occurred in the contrallateral retina at 1 month and thereafter. Thus, epicsleral vein cauterization altered glial reactivity not only in the ipsilateral but also in the contralateral eyes in rats. Less