MOLECULAR MECHANISMS UNDERLYING OPTIC NERVE REGENERATION

描述(逐字摘自申请者摘要)：长期目标 这项研究计划是为了阐明神经的分子机制。 生长和再生。人们普遍认为，大脑和大脑中的神经元 哺乳动物的视网膜不能再生神经纤维，这是一个很大的 治疗视网膜退行性疾病和损伤的挑战。 最近的数据表明，视网膜神经节细胞(RGC)是 它们伸展神经纤维的能力受到内在的调节，而且 原癌基因Bcl2是支持神经发生机制的关键调控因子 伸长率。Bcl2的这种促生长活性似乎并不是 其广为人知的抗凋亡功能的后果。中心问题 以下是Bcl2促进视网膜再生的机制 神经纤维。长期以来，人们已经认识到神经分化对 神经生长。现在已经很明显的是，Bcl2的过表达抑制了 分化信号的功能，P53介导的转录激活， 终末分化标志物在神经元中的表达。因此，它是 假设Bcl2可能是p53-p21WAF1途径的抑制因子 抑制神经末梢分化，从而维持 视网膜节细胞生长神经纤维。使用基因工程小鼠模型以及 新的视网膜顶盖共培养，这项研究计划旨在阐明 Bcl2可能支持视神经再生的功能通路(S)。 我们的目标是：(1)研究Bcl2是否抑制终末 通过测定RGC标志物和RGC标记物的水平和时间来分化RGC 分化相关蛋白在野生型和Bcl2视网膜中的表达 突变小鼠；(2)检测Bcl2是否支持神经再生 抑制分化信号，p53-p21WAF1通路。这里, 通过比较来评估Bcl2和P53之间的功能相互作用 P53的转录活性、亚细胞定位和磷酸化 在野生型、Bcl2突变和Bcl2/P53双突变小鼠中； 确定Bcl-2是否作用于共同的细胞通路以支持神经 通过比较Bclx分泌的视网膜节细胞的能力， 和Bcl-2转基因小鼠存活并再生神经纤维。给定 Bcl-2在神经元存活和神经再生中的功能重要性 这些研究应该为开发 神经保护性药物与多种疾病的治疗策略 由于细胞死亡和神经生长失调，包括青光眼和黄斑 退化。

DESCRIPTION (Verbatim from applicant's abstract): The long-term objective of this research plan is to elucidate the molecular mechanisms underlying nerve growth and regeneration. It is generally believed that neurons in the brain and retina of mammals are unable to regenerate nerve fibers, which presents a great challenge for the treatment of retinal degenerative disorders and damage. Recent data have established that retinal ganglion cells (RGCs) are intrinsically regulated in their ability to extend nerve fibers, and that the proto-oncogene Bcl-2 is a key regulator supporting the mechanism for nerve elongation. This growth-stimulating activity of Bcl-2 does not seem to be a consequence of its well-known anti-apoptotic function. The central question here is the mechanisms by which Bcl-2 promotes the regeneration of retinal nerve fibers. It has long been recognized that neural differentiation impacts nerve growth. It is now evident that overexpression of Bcl-2 suppresses the function of a differentiation signal, p53-mediated transcriptional activation, and expression of terminal differentiation markers in neurons. Therefore, it is hypothesized that Bcl-2 may function as a repressor of the p53-p21WAF1 pathway inhibiting neural terminal differentiation and thus, maintaining the ability of RGCs to grow nerve fibers. Using genetically-engineered mouse models as well as novel retinotectal co-cultures, this research plan is aimed at elucidating functional pathway(s) through which Bcl-2 may support optic nerve regeneration. Our goals are: (1) to investigate whether Bcl-2 inhibits the terminal differentiation of RGCs by determining levels and timing of RGC markers and differentiation-related protein expression in retinas of wild type and Bcl-2 mutant mice; (2) to test whether Bcl-2 supports nerve regeneration via suppression of the differentiation signal, p53-p21WAF1 pathway. Here, functional interactions between Bcl-2 and p53 will be assessed by comparing transcriptional activity, subcellular localization, and phosphorylation of p53 in wild type, Bcl-2 mutant, and Bcl-2/p53 double mutant mice; and (3) to determine whether Bcl-2 acts on a common cellular pathway to support nerve regeneration and neuronal survival by comparing the ability of RGCs from Bcl-x, and Bcl-2 transgenic mice to survive and regenerate nerve fibers. Given the functional importance of Bcl-2 in neuronal survival and nerve regeneration, these studies should provide valuable information for the development of neuroprotective drugs and therapeutic strategies for numerous diseases mediated by dysregulated cell death and nerve growth, including glaucoma and macular degeneration.