HUMAN RETINAL CELL LINES--A MODEL FOR RETINAL DEVELOPMENT

人类正常视网膜发育和营养不良的机制是 尽管有一半以上的人认为， 每年失明的美国人被诊断出患有一些遗传性疾病， 缺损阐明正常视网膜发育中的事件可能使我们 了解营养不良的基础及其更好的管理。最 关于人类视网膜发育的现有信息来自于 鸟类和啮齿动物模型以及少数人类研究仅限于肿瘤细胞 线由于采样有限，目前无法进行长期研究 在原代培养物中的祖先和衰老。我们提出 这是一种替代策略，使我们能够进行长期研究。 本提案的目的是建立年龄限制的细胞系 通过SV-40 T从发育中的（4、8、12个月胎儿）人视网膜组织中 基因转染和阐明近视网膜发育中的事件， 同质细胞群。我们已经建立了视网膜细胞 线（Dutt等，1994，1996）。人们普遍认为视网膜细胞是多细胞的， 潜力，但这种能力依赖于年龄吗？我们提出的关键问题 问：a）决定细胞命运的因素是内在的吗？ B）是细胞和分子的 细胞命运特异性祖细胞微环境的变化 决定？我们建议测试细胞系产生的假设， 不同年龄段的人会受到发育的限制， 它们产生不同细胞组合的能力， 内源性信号（谱系）的变化，2）外源性信号的变化， 或3）改变祖细胞对信号的响应能力 （外源性和内源性线索之间的相互作用）。本研究采用 细胞和分子的方法，我们将确定谱系的作用， 与视网膜发育中的细胞外信号相比。我们建议 实现以下目标：1）建立年龄限制的细胞系， SV-40 T基因转染人发育中的视网膜。2)确定细胞 谱系在不同年龄的祖先中所起的作用 通过内源性信号。3)确定内源和外源的作用 信号以及它们如何在细胞命运决定中相互作用。

Mechanisms underlying normal human retinal development and dystrophies are still not fully understood, despite the fact that more than half of Americans who become blind each year are diagnosed with some genetic defect. Elucidation of events in normal retinal development may allow us to understand the basis of dystrophies and their better management. Most of the information available on human retinal development emanates from avian of rodent models and few human studies are limited to tumor cell lines. No long term studies are currently possible due to limited sampling of progenitors and senescence that ensues in primary cultures. We propose an alternative strategy that will enable us to perform long term studies. The objective of this proposal is to establish age-restricted cell lines from developing (4, 8, 12 months fetal) human retinal tissues by SV-40T gene transfection and elucidate events in nearly retinal development in homogenous cell populations. We have already established a retinal cell line (Dutt et al 1994, 1996). It is accepted that retinal cells are multi- potential but is this capacity age dependent? The key questions we propose to ask: a) are the factors that determine cell fate intrinsic to progenitors and change developmentally, b) are cellular and molecular changes in micro environment of progenitors specific for cell fate decisions? We propose to test the hypothesis that cell lines generated from different ages will be developmentally restricted and will vary in their ability to generate different combinations of cells either due to 1) changes in endogenous signals (lineages), 2) changes in exogenous signals, or 3) changed ability of the progenitors to respond to signals (interaction between exogenous and endogenous cues). In this study, using cellular and molecular approaches, we will determine the role of lineages versus extracellular signals in retinal development. We propose to accomplish the following aims: 1) Establish age restricted cell lines from human developing retina by SV-40T gene transfection. 2) Determine cell lineages in progenitors from different ages to determine the role played by endogenous signals. 3) Determine the role of endogenous and exogenous signals and how they interact in cell fate determination.