Retinal Progenitors for Vision Rescue

描述（由申请人提供）：视锥细胞是视网膜相关黄斑变性中丢失的主要细胞类别。旨在取代丢失的视锥细胞的疗法将需要这些独特细胞的丰富来源。因此，明确需要鉴定将更丰富的多能细胞类型引导至视锥谱系所需的分子机制。我们制定了一个独特的方法来解决这个问题。我们的研究结果表明，小鼠胚胎干细胞，首先转化为原始外胚层，可以被定向培养成视锥细胞的命运。在体外锥形成需要同时抑制BMP和激活FGF信号，分别。在神经诱导过程中，这两种信号通路调节SMAD 1/5/8核转位（BMP）和降解（FGF），从而将外胚层细胞导向神经命运。在本申请中，我们概述了旨在确定这些信号通路及其下游组件如何通过调节经典和非经典BMP信号以及FGF信号产生视锥光感受器命运的实验。我们的假设是，调制SMAD 1/5/8的稳定性是必要的锥形成。先前的研究已经清楚地表明，视杆祖细胞移植到宿主视网膜的发育阶段对于细胞的成功分化和整合至关重要。我们的初步数据表明，锥细胞特异性蛋白质和基因的光转导级联已经在我们的细胞中表达。表征它们的分子，形态和生理特性将有助于我们确定这些在体外产生的锥体的相对年龄。我们的研究很好地符合国家眼睛和视力研究计划的目标（http：www.nei.nih.gov/strategicplanning/ np_strab.asp），其中包括“确定干细胞如何在视觉系统的发育中分化，以及它们如何用于理解视觉系统中细胞类型特异性身份的分子逻辑。“该项目将确定有助于视锥细胞生成的分子机制，并成为未来研究的基础，重点关注这些细胞取代因视网膜损伤和变性而丢失的视锥细胞的能力。

DESCRIPTION (provided by applicant): Cone photoreceptors are the primarily cell class lost in Age-Related Macular Degeneration. Therapies designed to replace lost cones will require a rich source of these unique cells. Consequently, there is a clear need to identify the molecular mechanisms required to direct more plentiful pluripotent cells types to a cone lineage. We have developed a unique approach to addressing this problem. Our results demonstrate that mouse embryonic stem cells, first converted to primitive ectoderm, can be directed to a cone cell fate in culture. In vitro cone formation requires simultaneous repression of BMP and activation of FGF signaling, respectively. During neural induction, these two signaling pathways regulate SMAD1/5/8 nuclear translocation (BMP) and degradation (FGF), which directs ectodermal cells to a neural fate. In this application, we outline experiments designed to identify how these signaling pathways and their downstream components generate cone photoreceptor fate, by regulating both canonical and non-canonical BMP signaling as well as FGF signaling. Our hypothesis is that modulation of SMAD1/5/8 stability is required for cone formation. Previous studies have clearly demonstrated the developmental stage at which rod progenitors are transplanted to the host retina is critical for successful differentiation and integration of the cells. Our preliminary data demonstrates cone specific proteins and genes of the phototransduction cascade are already expressed in our cells. Characterizing their molecular, morphological and physiological properties will help us to determine the relative age of these in vitro-generated cones. Our research fits well into the National Plan for Eye and Vision Research objectives (http://www.nei.nih.gov/strategicplanning/ np_strab.asp), which include "determine(ing) how stem cells differentiate in the development of the visual system and how they can be used to understand the molecular logic of cell-type- specific identity in the visual system." This project will identify molecular mechanisms that contribute to cone cell generation and form the basis of future studies focusing on the ability of these cells to replace cones lost to retinal damage and degeneration.