Molecular Biological Study on Mechanism of Neuronal Cell Death and Establishment of New Therapy in Glaucoma

细胞死亡被认为是由谷氨酸刺激视网膜神经节细胞和内核层细胞上的n -甲基-d-天冬氨酸（NMDA）受体引起的。利用敲除小鼠来阐明NMDA受体NR2A和NR2B亚基的作用。采用野生型和NR2A和NR2B亚基敲除小鼠。眼压升高至120mmHg诱导短暂性视网膜缺血。在野生型小鼠中，14天后视网膜神经节细胞全部消失。内核层细胞数量减少。内丛状层厚度减小。相比之下，在NR2A亚基敲除小鼠中，视网膜似乎是正常的，没有受到损伤。而NR2B亚基敲除小鼠也表现出相同的趋势。这些结果提示该亚基可能在缺血再灌注引起的视网膜细胞死亡中起直接作用。定量测定实验性高眼压模型大鼠视网膜内脑源性神经营养因子（BDNF）水平。为了诱导单侧IOP升高，我们使用了Ueda等人（1998）开发的模型。同伴的眼睛作为对照。眼压测定采用气压计。在IOP高于22 mmHg持续1、2、4和12周后，分别从实验眼和对照眼中取出视网膜作为样本。采用酶联免疫吸附法定量BDNF蛋白水平。在IOP升高1、2、4和12周后，与对照组相比，高血压眼的视网膜BDNF水平分别为277%、102%、59%和24%。本研究阐明了实验性高眼压模型大鼠视网膜中BDNF水平的显著改变。

Cell death has been thought to be induced by glutamate that stimulates the N-methyl-d-aspatate (NMDA) receptor present on retinal ganglion cells and on cells in the inner nuclear layer. Knock out mice were used to elucidate the role of the NR2A and NR2B subunit of the NMDA receptor. Wild type and NR2A and NR2B subunit knock out mice were used. Transient retinal ischemia was induced by raising intraocular pressure (IOP) to 120mmHg. In the Wild type mice, all the retinal ganglion cells were lost after 14 days. The number of cells in the inner nuclear layer was decreased. The thickness of the inner plexiform layer was reduced. By contrast, the retina appeared to be normal, unaffected by the insult in the NR2A subunit knockout mice. While the NR2B subunit knock out mice also showed the same tendency. These results suggest that the subunit may have a direct role in the retinal cell death induced by ischemia-reperfusion.We quantifies the level of brain-derived neurotrophic factor (BDNF) in the retina of experimental ocular hypertension model rat. To induce unilateral IOP elevation, we used a model developed by Ueda et al. (1998). Fellow eyes were served as control. IOP was measured by pneumatonometer. After the duration of IOP elevation above 22 mmHg for 1, 2, 4 and 12 weeks, retinas were dissected out from both experimental and control eyes and used as samples. To quantify BDNF protein level, we used enzyme-linked immunosorbant assay. Retinal BDNF levels of hypertensive eye compared to control after 1, 2, 4 and 12 weeks of IOP elevation were 277%, 102%, 59% and 24%, respectively. This study clarifies that BDNF levels were dramatically altered in the retina of experimental ocular hypertension model rat.