MOLECULAR CONTROL OF RETINAL STEM CELL DEVELOPMENT

视网膜干细胞发育的分子控制

• 批准号: 2605218
• 负责人: Peter H Mathers
• 金额: $ 9.61万
• 依托单位: WEST VIRGINIA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-03-01 至 2003-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2605218
• 关键词: cell differentiation; cell line; cell proliferation; congenital eye disorder; developmental genetics; early embryonic stage; embryonic stem cell; gene expression; gene mutation; gene targeting; homeobox genes; human genetic material tag; in situ hybridization; laboratory mouse; mammalian embryology; microphthalmos; optic tract; polymerase chain reaction; regulatory gene; retina; retinal pigment epithelium

Commitment of cells to form a retina occurs during early embryogenesis as the neural plate is regionalized into specific domains. Once specified to become retina, the precursor cells proliferate as stem cells until signaled to stop dividing and differentiate. Retinal stem cells are multipotent, giving rise to all of the cells of the pigmented and neural retina, and are capable of participating in retinal regeneration in lower vertebrates. We have chosen to study genes likely to control retinal stem cell fate in an effort to determine the molecular mechanisms that control the establishment and proliferation of the retina. Several homeobox-containing trasncriptional regulatory genes are important for the proper formation of the eye during embryonic development, including Pax6, Chx10 and Lhx2. A new family of retinal homeobox genes, Rx, is expressed in a spatial and temporal pattern consistent with a role in retinal stem cell specification and proliferation. The function of the Rx gene is crucial for proper eye formation, as overexpression causes hyperproliferation of the neural retina and retinal pigment epithelium, and targeted deletion of the Rx gene in the mouse eliminates optic vesicle formation and results in the birth of eyeless mouse pups. Our proposed studies are aimed at identifying the mechanisms by which Rx regulates early mammalian eye development. We have designed three strategies in different experimental systems to study the role of Rx during retinal formation, proliferation and differentiation. Using gene expression studies in mice carrying different ocular mutations, we will investigate whether Rx is necessary for the initial specification of retinal cell fate. An analysis of later Rx function during retinal stem cell proliferation and differentiation will be performed using molecular techniques in primary mouse retinal cultures and human retinoblastoma cells. Finally, we propose to screen DNA samples from anophthalmic patients for mutations in the human Rx gene. These experiments will elucidate the role of the Rx homeobox gene in human eye development. The proposed studies have important implications for our basic understanding of ocular organogenesis, and may contribute to medical treatment strategies for retinoblastoma, retinal degeneration and anophthalmia.

细胞形成视网膜的过程发生在早期胚胎发生过程中 因为神经板被划分为特定的区域。 一次 指定成为视网膜，前体细胞增殖为干细胞 细胞直到收到停止分裂和分化的信号。 视网膜干 细胞是多能的，可产生所有有色素的细胞 和神经视网膜，并且能够参与视网膜 低等脊椎动物的再生。 我们选择研究基因 控制视网膜干细胞的命运，以确定 控制建立和增殖的分子机制 视网膜的。 几个含有同源盒的转录调控基因是 对于胚胎时期眼睛的正确形成很重要 开发，包括 Pax6、Chx10 和 Lhx2。 视网膜新家族 同源盒基因 Rx 以空间和时间模式表达 与视网膜干细胞规范中的作用一致并且 增殖。 Rx 基因的功能对于正常视力至关重要 形成，因为过度表达会导致神经细胞过度增殖 视网膜和视网膜色素上皮，以及 Rx 的定向删除 小鼠体内的基因消除了视神经泡的形成并导致 无眼小老鼠的诞生。 我们提出的研究旨在 确定 Rx 调节早期哺乳动物眼睛的机制 发展。 我们在不同的实验系统中设计了三种策略 研究 Rx 在视网膜形成、增殖和发育过程中的作用 差异化。 在小鼠身上进行基因表达研究 不同的眼部突变，我们将研究是否需要 Rx 用于视网膜细胞命运的初步规范。 分析 视网膜干细胞增殖过程中的后期 Rx 功能 将使用分子技术在初级中进行分化 小鼠视网膜培养物和人视网膜母细胞瘤细胞。最后，我们 提议对无眼患者的 DNA 样本进行突变筛查 存在于人类 Rx 基因中。这些实验将阐明 Rx 同源盒基因在人眼发育中的作用。 拟议的研究有 对于我们对眼部的基本理解具有重要意义 器官发生，并可能有助于医疗策略 视网膜母细胞瘤、视网膜变性和无眼症。