Neurotrophin regulation of mRNA localization and translation in axons.

描述(由申请人提供)：神经营养因子在支持神经元终生存活方面发挥着关键作用。这种作用需要神经营养因子促进细胞体的健康，以及成熟神经元特有的广泛树突和轴突的健康。最近的研究表明，促进轴突存活的机制与调节细胞体存活的机制只有部分重叠。拟议的工作集中在神经营养因子对轴突活性的调节，以及专门的Bcl2家族成员Bcl2-w在这一过程中的作用。赞助商实验室的工作表明，在背根节(DRG)感觉神经元的轴突中，Bcl-w的mRNA和蛋白高水平表达，并且在体内，Bcl-w的缺失导致轴突的选择性变性。此外，Bclw的表达受神经营养因子刺激，尤其是轴突的神经营养因子刺激的调节。综上所述，这些数据表明，Bclw是一种特殊的轴突存活因子，它介导了神经营养因子对轴突存活的影响。这项研究提案中提出的两个目标建立在发起人之前的研究基础上，并将直接测试神经营养因子如何调节轴突中的Bcl-w mRNA和蛋白，以了解维持轴突健康的机制。目的：验证3‘非编码区在bclw基因定位轴突中起关键作用的假说。为了做到这一点，将测试BCL-w 3‘UTR将报告序列定位到轴突的能力。目的2：验证神经营养因子调控bclw在轴突中局部翻译的假说。要做到这一点，将使用一种新的方法，这种方法比目前研究轴突翻译的技术有几个优点。在初步研究中，我已经证明了这种方法在DRG神经元和隔室培养中的有效使用。轴突局部合成的Bclw可能为神经营养因子对轴突存活和维持的持续作用提供了一种机制。这项工作将加深我们对神经营养因子如何促进不同细胞间隔的生存和健康以及轴突在整个生命中保持的机制的理解。了解神经营养因子调节轴突活性的机制对于了解轴突变性的机制和寻找神经退行性疾病的治疗靶点至关重要。

DESCRIPTION (provided by applicant): Neurotrophins play a critical role in supporting neuronal viability throughout life. This role requires that neurotrophins promote the health of cel bodies and also the health of extensive dendrites and axons characteristic of mature neurons. Recent studies have demonstrated that the mechanisms which promote axonal viability only partially overlap with those that regulate cell body survival. The proposed work focuses on neurotrophin regulation of axonal viability, and the role of the specialized Bcl2 family member Bcl-w in this process. Work from the sponsor's lab has demonstrated that Bcl-w mRNA and protein are expressed at high levels in axons of dorsal root ganglia (DRG) sensory neurons, and that loss of Bcl-w results in selective degeneration of axons in vivo. Furthermore, Bcl-w expression is regulated by neurotrophin stimulation, and in particular, by neurotrophin stimulation of the axons. Together, these data suggest that Bcl-w is a specialized axonal survival factor that mediates the effects of neurotrophins on axonal viability. The two aims presented in this research proposal build on previous studies from the sponsor, and will directly test how neurotrophins regulate Bcl-w mRNA and protein in axons, in order to understand mechanisms for maintaining axonal health. Aim1: To test the hypothesis that the 3'UTR is critical for targeting bcl-w mRNA to axons. To do this, the bcl-w 3'UTR will be tested for its abilty to localize a reporter sequence to axons. Aim 2: To test the hypothesis that neurotrophins regulate local translation of bcl-w in axons. To do so, a novel method which provides several advantages over current techniques of studying translation in axons will be used. In preliminary studies I have demonstrated effective use of this method in DRG neurons and compartmented cultures. Local synthesis of Bcl-w in axons may provide a mechanism for mediating the sustained effect of neurotrophins on axonal viability and maintenance. This work will develop our understanding of how neurotrophins promote survival and health of distinct cellular compartments and the mechanisms by which axons are maintained throughout life. Understanding the mechanisms by which neurotrophins regulate axonal viability are essential to understanding mechanisms of axonal degeneration and finding therapeutic targets for disorders of neurodegeneration.