CNTF PROMOTES NEURONAL SURVIVAL AND AXONAL SPROUTING

这个子项目是许多利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 一般的神经营养因子和特别是睫状神经营养因子（CNTF）继续被认为是用于治疗各种急性和慢性神经变性病症的有吸引力的治疗剂，所述病症包括创伤性脑损伤、帕金森氏病和亨廷顿病以及肌萎缩性侧索硬化。 然而，尽管CNTF具有潜在的临床重要性，但关于其在成人脑中的表达或其体内作用的机制知之甚少。 我实验室的长期目标是更好地了解神经营养因子和相关细胞因子促进受损CNS中神经元存活和过程生长的机制。 我们的中心假设是，CNTF作为一个神经元的存活因子和发芽因子的大细胞神经分泌神经元在体内通过激活特定的信号转导通路。 为了支持这一假设，我们已经证明，轴突切断术的结果在CNTF的表达显着增加在轴突切断视上核和对侧发芽视上核。 此外，我们有初步的数据显示信号转导和转录激活因子（STAT）蛋白的激活响应轴突切断术和以下直接输注大鼠重组CNTF（rrCNTF）在视上核体内。 鉴于这些观察结果，拟议研究的目的是：1）确定参与大细胞对损伤和外源性rrCNTF反应的特定信号传导途径及其在促进神经元存活和过程生长中的作用; 2）定义体内长期给予rrCNTF诱导的细胞反应;和3）确定用外源性rrCNTF刺激大细胞神经元是否将克服神经元发芽功效的成熟性下降，并确定降低的CNTF或STAT活性是否有助于这种下降。 追求这些目标将部分实现使用慢性输液的生长因子，免疫细胞化学，Western印迹分析，定量RT-PCR，原位杂交，电泳迁移率变化测定和器官型文化。 阐明CNTF通过直接与神经元相互作用或间接通过胶质细胞活化介导神经元存活和轴突发芽的机制，将为我们理解神经营养因子介导的神经修复活性在整个CNS中的控制提供重要进展。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Neurotrophic factors in general and ciliary neurotrophic factor (CNTF) in particular continue to be considered attractive therapeutic agents for the treatment of a variety of acute and chronic neurodegenerative conditions including traumatic brain injury, Parkinson's and Huntington's disease and amytrophic lateral sclerosis. However, despite the potential clinical importance of CNTF, little is known regarding its expression in adult brain or the mechanisms of its actions in vivo. The long term goal of my laboratory is to gain a greater understanding of the mechanisms by which neurotrophins and related cytokines promote neuronal survival and process outgrowth in the damaged CNS. Our central hypothesis is that CNTF acts as both a neuronal survival factor and sprouting factor for magnocellular neurosecretory neurons in vivo through activation of specific signal transduction pathways. In support of this hypothesis, we have demonstrated that axotomy results in a significant increase in CNTF expression in both the axotomized supraoptic nucleus and in the contralateral sprouting supraoptic nucleus. Furthermore, we have preliminary data which shows activation of Signal Transducer and Activator of Transcription (STAT) proteins in response to axotomy and following direct infusion of rat recombinant CNTF (rrCNTF) in the supraoptic nucleus in vivo. In light of these observations, the objectives of the proposed studies are to: 1) Determine the specific signal transduction pathways involved in the magnocellular response to injury and to exogenous rrCNTF and their role in the promotion of neuronal survival and process outgrowth; 2) Define the cellular responses induced by chronically administered rrCNTF in vivo; and 3) Determine if stimulation of magnocellular neurons with exogenous rrCNTF will overcome the maturational decline in neuronal sprouting efficacy and determine if reduced CNTF or STAT activity contributes to this decline. Pursuit of these objectives will be accomplished in part using chronic infusion of growth factors, immunocytochemistry, Western blot analysis, quantitative RT-PCR, in situ hybridization, electrophoretic mobility shift assays and organotypic cultures. Eludicating the mechanisms by which CNTF mediates neuronal survival and axonal sprouting either through direct interactions on neurons or indirectly through glial activation will provide a significant advancement in our understanding of how neurotrophin-mediated neurorestorative activities are controlled throughout the CNS.