The role of the bHLH transcription factor NeuroD in regulating photoreceptor rege

描述（由申请人提供）：光感受器退行性疾病导致人类永久性视力丧失。恢复人类视力的再生疗法的发展将需要在目前对干细胞再生机制的理解上取得实质性进展。我们研究的长期目标是了解控制视网膜中基于干细胞的神经元再生的分子机制，以斑马鱼为模型生物。实现这一目标的下一步，以及本研究的总体目标，是辨别NeuroD在光感受器再生中的作用。这一目标将通过测试NeuroD是控制光感受器再生的信号通路中的关键分子这一中心假设来实现。这一假设将通过实现两个具体目标来验证。Specific Aim 1将测试以下假设：1)光感受器祖细胞在光感受器再生过程中退出细胞周期需要NeuroD； 2)光感受器再生所必需的下游基因介导了NeuroD的功能。这将通过比较正常视网膜和神经性缺陷视网膜再生中的光感受器再生、细胞增殖和下游基因表达来完成。Specific Aim 2将验证在光感受器再生过程中，NeuroD介导典型Wnt信号在光感受器祖细胞中的功能的特定假设。这将通过比较神经d的表达和典型Wnt效应物(？-catenin)，并确定典型Wnt信号操纵对神经d表达的影响。这项研究将为理解调节脊椎动物光感受器再生的途径提供重要的一步，并将有助于我们了解神经系统中调节干细胞再生的因素。这一贡献将为旨在治疗人类视网膜疾病的再生疗法的发展提供关键信息。

DESCRIPTION (provided by applicant): Photoreceptor degenerative diseases lead to permanent vision loss in humans. The development of regenerative therapies that restore vision in humans will require substantial advances to the current understanding of mechanisms of stem cell-based regeneration. The long-term goal of our research is to understand the molecular mechanisms that govern stem cell-based neuronal regeneration in the retina, using zebrafish as a model organism. A next step in achieving this goal, and the overall objective of the present research, is to discern the role of NeuroD in photoreceptor regeneration. This objective will be accomplished by testing the central hypothesis that NeuroD is a key molecule in signaling pathways that control photoreceptor regeneration. This hypothesis will be tested by accomplishing 2 specific aims. Specific Aim 1 will test the specific hypotheses that 1) NeuroD is required for photoreceptor progenitors to exit the cell cycle during photoreceptor regeneration and 2) NeuroD function is mediated via downstream genes that are essential for photoreceptor regeneration. This will be accomplished by comparing photoreceptor regeneration, cell proliferation, and expression of downstream genes in regenerating retinas between normal and NeuroD-deficient retinas. Specific Aim 2 will test the specific hypothesis that NeuroD mediates the function of canonical Wnt signaling in photoreceptor progenitors during photoreceptor regeneration. This will be accomplished by comparing neuroD expression and localization of the canonical Wnt effector (?-catenin), and determining the effects of canonical Wnt signaling manipulation on neuroD expression. This research will provide a significant and important step toward understanding pathways regulating photoreceptor regeneration in vertebrates, and will contribute to our fundamental knowledge of factors regulating stem cell-based regeneration in the nervous system. This contribution will provide critical information applicable to the development of regenerative therapies aimed at treating human retinal disease.