Molecular Analysis of Retinal Ganglion Cell Death

描述(申请人提供)：青光眼是一种疾病，其特征是由于视网膜神经节细胞死亡而导致视野丧失。虽然眼压升高仍然是青光眼最明确的危险因素，但越来越明显的是，其他各种因素也可以导致神经节细胞丢失。药物或手术调节眼压可以使许多患者稳定下来，但对一些患者来说，仍有进行性的视力丧失。因此，迫切需要开发新的合理策略来减缓或防止青光眼中发生的神经元丢失。有大量证据表明，眼睛像中枢神经系统的其他区域一样，含有内源性神经营养/神经保护因子，这些因子的功能是限制细胞损伤。这项提议的基本前提是，可以利用这些神经保护机制来防止与青光眼等疾病相关的大部分细胞死亡。这项建议集中在一种神经保护分子CNTF上，这种因子已经被证明在包括视网膜在内的许多中枢神经系统区域具有强大的神经保护作用，是减缓神经节细胞丧失进展的主要候选者。在我们的初步数据中，我们提出了CNTF支持纯化的大鼠视网膜神经节细胞在低密度培养中存活的证据，以及它的下游效应因子STAT3阻止了视网膜神经节细胞在缺血再灌注损伤中的退化。我们现在提出一系列实验来测试CNTF是否可以防止RGC在毒性水平的谷氨酸存在的情况下死亡。在第一个目标中，我们将定义CNTF发挥其保护作用的途径。其次，我们将研究Muller胶质细胞是否可以对CNTF做出反应，并通过分泌额外的神经保护因子或一系列其他反应来为RGCs提供协同保护。最后，我们将测试CNTF激活的保护通路是否通过激活线粒体解偶联蛋白来减少线粒体产生的活性氧。 与公共卫生相关：青光眼是一种致盲疾病，全世界有超过6500万人受到影响。目前对导致视网膜细胞死亡和随后丧失视力的基本生化机制仍没有很好的了解。这项研究将确定其中一些生化途径。这项研究的结果将导致识别目标分子，为其设计新的治疗药物。

DESCRIPTION (provided by applicant): Glaucoma is a disease characterized by visual field loss as a result of the death of retinal ganglion cells. Although increased intraocular pressure remains the most clearly defined risk factor for glaucoma, it is becoming clear that a wide range of other factors can also lead to ganglion cell loss. Pharmacological or surgical regulation of intraocular pressure can stabilize many patients but for some there is still a progressive loss of vision. Thus, there is an urgent need to develop new rational strategies to slow or prevent neuronal loss occurring in glaucoma. There is abundant evidence that the eye, like other regions of the CNS, contains endogenous neurotrophic/neuroprotective factors that function to limit cell injury. It is the basic premise of this proposal that these neuroprotective mechanisms can be exploited to prevent much of the cell death associated with diseases such as glaucoma. This proposal focuses on one neuroprotective molecule, CNTF, a factor that has already been shown to have potent neuroprotective effects in a number of CNS regions including the retina and is a leading candidate for slowing the progression of ganglion cell loss. In our preliminary data we present evidence that CNTF supports the survival of purified rat RGCs in low density cultures and that its downstream effector STAT3 prevents RGCs from degenerating in ischemia- reperfusion injury. We now propose a series of experiments to test if RGCs can be prevented from dying in the presence of toxic levels of glutamate by CNTF. In a first aim we will define the pathways used by CNTF to exert its protective action. Second, we will examine whether Muller glia can respond to CNTF and provide synergistic protection to RGCs by the secretion of additional neuroprotective factors or a range of other responses. Finally we will test whether the protective pathways activated by CNTF lead to a reduction in reactive oxygen species generation by mitochondria through the activation of mitochondrial uncoupling proteins. PUBLIC HEALTH RELEVANCE: Glaucoma is a blinding disease that affects over 65 million people worldwide. There is still not a good understanding of the basic biochemical mechanisms which cause the death of retinal cells and subsequent loss of vision. This research will identify some of these biochemical pathways. The results of this research will lead to the identification of target molecules for which new therapeutic drugs can be designed.