Neurogenesis at the mammalian retinal-ciliary margin

描述（由申请人提供）：本提案的长期目标是深入了解哺乳动物视网膜睫状缘的神经元生成潜力以及其中细胞的分子和细胞特性。这对受损视网膜中功能神经元的再生具有重要意义。该建议的重点是视网膜神经节细胞（RGC）形成能力的细胞在视网膜睫状缘。RGC在视觉功能中起重要作用。RGC的缺失导致人类的主要眼部疾病，包括青光眼、诺里病和其他视神经病变。干细胞给药，包括补充健康的视网膜干细胞和体内激活潜在的视网膜干细胞，提高了治疗这些疾病的希望。然而，从睫状缘分离的成体干细胞具有有限的分化潜能;它们不会产生RGCs和其他“早期”视网膜细胞类型。负调控哺乳动物视网膜睫状缘RGC形成的分子和细胞机制在很大程度上仍然未知。最近在小鼠基因工程和基因传递技术的进展提供了新的工具，探索视网膜睫状缘的属性。本申请将探讨视网膜睫状缘的分子和细胞特性。基于视网膜边缘的细胞可以保持其RGC形成能力一段潜伏期，但最终失去这种潜力的假设，提出了三个具体的目标：1）确定哺乳动物视网膜睫状体边缘可以保持多长时间形成新的神经元的潜力。2)确定如果产生新的神经元，是否可以产生RGC。3)确定是否RGCs，第一个出生的视网膜细胞类型，可以从成人睫状缘产生时，最小的细胞内在因素供应。本实验将利用先进的条件基因打靶技术和基因工程小鼠品系，探索RGC形成的分子机制。这些实验的结果将使我们能够确定在任何给定的时间睫状缘细胞的能力状态。本研究结果也将有助于进一步了解哺乳动物视网膜边缘的调控机制，并为设计细胞变性相关视网膜疾病的治疗方法提供信息。公共卫生相关性：拟议的项目研究哺乳动物视网膜边缘的细胞和分子特性。本研究的结果将为利用视网膜边缘细胞来修复病变或受损的视网膜提供有价值的信息。

DESCRIPTION (provided by applicant): The long term objective of this proposal is to gain insights into the neuron generation potential of the mammalian retinal-ciliary margin as well as the molecular and cellular properties of cells within. This has important implications for the regeneration of functional neurons in damaged retinas. The proposal focuses on the retinal ganglion cell (RGC) forming competency of cells at the retinal-ciliary margin. RGCs play an essential role in visual function. Abnormalities in RGCs lead to major eye diseases in humans including glaucoma, Norrie disease, and other optic neuropathies. Stem cell administration, including supplementary of healthy retinal stem cells and in vivo activation of potential retinal stem cells, raises the hope for treating these diseases. However, isolated adult stem cells from the ciliary margin have limited differentiation potential; they do not give rise to RGCs and other "early" retinal cell types. The molecular and cellular mechanism negatively regulating RGC formation at the mammalian retinal-ciliary margin remains largely unknown. Recent advances in mouse genetic engineering and gene delivery technologies have provided new tools for exploring properties of the retinal-ciliary margin. This application will explore the molecular and cellular properties of the retinal-ciliary margin. Based on the hypothesis that cells in the retinal margin can retain their RGC forming competency for a latent period of time but eventually lose such a potential, three specific aims are proposed: 1) Determine how long can the mammalian retinal-ciliary margin retain its potential of forming new neurons. 2) Determine whether RGCs can be produced if new neuron is generated. 3) Determine whether RGCs, the first born retinal cell type, can be produced from the adult ciliary margin when minimal cell-intrinsic factors are supplied. Proposed experiments will take advantage of the advanced conditional gene targeting strategy and genetic engineered mouse lines generated during our past studies in quest of molecular mechanism in RGC formation. Results of these experiments will allow us to determine the state of competency of the ciliary margin cells at any given time. The results will also shed light into the regulation mechanism at mammalian retinal margin and provide information for designing treatments to cell degeneration related retinal diseases. PUBLIC HEALTH RELEVANCE: The proposed project studies cellular and molecular properties in the mammalian retinal margin. The result of this study will provide valuable information on utilizing cells from the retinal margin to replenish diseased or damaged retina.