Function of math5 in Retinal Development

描述(由申请人提供)：本提案的长期目标 是为了了解脊椎动物视网膜发育的分子机制 寻找调控视网膜神经元正常分化的基因。 在小鼠中，math5和brn-3b在发育早期的视网膜中表达。 分别从胚胎第11天和11.5天(E11和E11.5)开始。他们的 视网膜的时空表达模式与糖尿病视网膜病变的发病相关 视网膜神经节细胞(RGC)分化，提示它们在 视网膜节细胞的分化。以前的研究已经证明，有针对性的 小鼠BRN-3b基因缺失导致轴突形成失败 视网膜发育早期视网膜节细胞程序性死亡。目标人群 Math5的突变导致缺乏一大组RGC并取消 RGC特异性表达BRN-3b在视网膜发育中的作用该表达式和 突变研究表明，Math5是神经原基因 视网膜节细胞的发育及视网膜前体细胞中math5的表达 决定了视网膜神经节细胞的命运。此外，BRN-3b的缺失 在math5-空视网膜中的表达表明BRN-3b是下游 RGC发育过程中math5调控通路的效应基因。三 为了准确地定义math5在视网膜中的作用，提出了具体的目标 Math5与BRN-3b基因的发育及亲缘关系的建立：(1)小鼠 将建立细胞系以激活LacZ报告基因的稳定表达 在表达math5的细胞中，以及这些细胞的命运 在整个发展过程中。特别地，math5突变对RGC的影响 分化、迁移、程序性细胞死亡或转化为非RGC 命运将会被评估。(2)math5转换视网膜的能力 将通过在视网膜祖细胞中表达math5来测试向RGC分化的祖细胞 体内或视网膜外植体培养中的细胞。(3)监管关系 Brn-3b和math5之间的关系将使用math5和brn-3b突变体进行分析 小鼠和常规启动子分析方法。获取的信息来自 这些研究将极大地促进我们对 正常视网膜发育和视网膜中的转录因子 退行性疾病。这些研究的结果可以为 设计治疗方法以维持视网膜细胞的活性并 再生视网膜神经元。

DESCRIPTION (provided by applicant): The long-term objective of this proposal is to understand the molecular mechanisms of vertebrate retinal development and to identify the genes regulating the normal differentiation of retinal neurons. In mice, math5 and brn-3b are expressed early in the developing retinas starting at embryonic day 11 and 11.5 (E11 and E 11.5), respectively. Their temporal and spatial expression pattern in retina correlates with the onset of retinal ganglion cell (RGC) differentiation, suggesting their roles in the differentiation of RGCs. Previous studies have demonstrated that targeted deletion of brn-3b in mice causes the failure of axon formation and the programmed cell death of RGCs in early retinal development. The targeted mutation of math5 results in the absence of a large set of RGCs and abolishes the RGC-specific expression of brn-3b in developing retina. The expression and mutation studies have suggested that math 5 is the proneural gene for the development of RGCs and expression of math5 in the retinal progenitor cells defines the retinal ganglion cell fate. In addition, the absence of brn-3b expression in math5-null retinas suggests that brn-3b is the downstream effector gene of the math5 regulatory pathway in RGC development. Three specific aims are proposed to precisely define the role of math5 in retinal development and to establish relationship between math5 and brn-3b: (1) Mouse lines will be created to activate the stable expression of lacZ reporter gene in math5-expressing cells and the fates of these cells will be analyzed throughout development. Specifically, the effect of math5 mutation on RGC differentiation, migration, programmed cell death or converting to non-RGC fates will be assessed. (2) The ability of math5 to convert the retinal progenitors into RGCs will be tested by expressing math5 in retinal progenitor cells in vivo or in retina explant cultures. (3) The regulatory relationship between brn-3b and math5 will be analyzed using the math5 and brn-3b mutant mice and conventional promoter analysis approaches. Information obtained from these studies will significantly advance our understanding of the roles of transcriptional factors in normal retinal development and in retinal degenerative diseases. Results of these studies could provide the foundation of designing therapeutic approaches to maintain retinal cell viability and to regenerate retinal neurons.