Neurotrophin regulation of mRNA localization and translation in axons.

描述（由申请人提供）：神经营养素在整个生命过程中支持神经元的生存能力起着至关重要的作用。这一作用要求神经营养物质促进细胞体的健康，以及成熟神经元特有的广泛的树突和轴突的健康。最近的研究表明，促进轴突活力的机制与调节细胞体存活的机制只有部分重叠。本研究的重点是神经营养因子对轴突活力的调控，以及Bcl2家族成员Bcl-w在这一过程中的作用。发起人实验室的研究表明，Bcl-w mRNA和蛋白在背根神经节（DRG）感觉神经元的轴突中高水平表达，Bcl-w的缺失导致体内轴突的选择性变性。此外，Bcl-w的表达受神经营养因子刺激，特别是神经营养因子对轴突的刺激调节。综上所述，这些数据表明Bcl-w是一种特殊的轴突存活因子，介导神经营养因子对轴突生存能力的影响。本研究计划提出的两个目标建立在发起人先前的研究基础上，并将直接测试神经营养因子如何调节轴突中的Bcl-w mRNA和蛋白质，以了解维持轴突健康的机制。目的1：验证3'UTR对于bcl-w mRNA靶向轴突至关重要的假设。为此，将测试bcl- w3 ' 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轴突bcl-w局部翻译的假说。为了做到这一点，将使用一种新颖的方法，该方法比目前研究轴突翻译的技术提供了几个优势。在初步研究中，我已经证明了这种方法在DRG神经元和区隔培养中的有效应用。轴突中Bcl-w的局部合成可能是神经营养物质对轴突生存和维持的持续作用的一种机制。这项工作将加深我们对神经营养因子如何促进不同细胞区室的生存和健康以及轴突在整个生命中维持的机制的理解。了解神经营养因子调节轴突活力的机制对于理解轴突变性的机制和寻找神经变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.