Regulation of neurotrophin expression in the periphery

外周神经营养蛋白表达的调节

• 批准号: 6899040
• 负责人: LORI G ISAACSON
• 金额: $ 21.3万
• 依托单位: MIAMI UNIVERSITY OXFORD
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6899040
• 关键词: antibody; enzyme linked immunosorbent assay; ganglions; gene expression; genetic regulation; innervation; laboratory rat; messenger RNA; nerve growth factors; neurons; neurophysiology; neuroregulation; polymerase chain reaction; sympathetic nervous system; western blottings

DESCRIPTION (provided by applicant): The underlying hypothesis of the present study is that the survival of peripheral neurons is regulated by the neurotrophins nerve growth factor (NGF) and neurotrophin-3 (NT-3). The mechanisms regulating the expression of these neurotrophins are poorly understood. The processing of the NGF gene product results in preproneurotrophin which, following proteolytic cleavage, results in the mature form of NGF. Yet, using Western blot analysis, we observed very little mature NGF form in peripheral neurons or target tissues. In fact, the majority of neurotrophic protein expressed in these tissues (superior cervical ganglion, trigeminal ganglion and peripheral targets) was proNGF along with large molecular weight NGF precursors, with each tissue exhibiting a characteristic NGF expression pattern. NT-3 appears to undergo similar processing though it is not well studied. One goal of the current project is to use NGF and NT-3 Western analysis to correlate tissue-specific NGF and NT-3 expression patterns with protein detection obtained using ELISA and to determine any influences of a two week in vivo intracerebroventricular infusion of NGF. Also, using real time RT-PCR, we detect NGF and NT-3 transcripts in peripheral ganglia, both of which are influenced by exogenous NGF and neuronal activity. The primary objectives of this study are to: 1) Investigate NGF protein and mRNA expression in sympathetic and sensory ganglia and peripheral target tissues and determine any effects of in vivo exogenous NGF; 2) Determine the effects of exogenous NGF on NT-3 protein and mRNA expression in peripheral ganglia and targets; 3) Delineate the role of neuronal activity in NGF and NT-3 expression in peripheral tissues; and 4) Examine the regulatory influences of sympathetic innervation on neurotrophin expression in peripheral targets. The results of this project will contribute to our understanding of the complex mechanisms regulating neurotrophin expression, and thus neuronal survival, and will help to determine the factors responsible for the neuronal death that occurs in aging and disease.

描述（由申请人提供）：本研究的基本假设是外周神经元的存活受神经营养因子神经生长因子（NGF）和神经营养因子-3（NT-3）的调节。调节这些神经营养因子表达的机制知之甚少。NGF基因产物的加工产生前原神经营养因子，其在蛋白水解裂解后产生成熟形式的NGF。然而，使用Western印迹分析，我们观察到在外周神经元或靶组织中很少有成熟的NGF形式。事实上，在这些组织（上级颈神经节、三叉神经节和外周靶）中表达的大多数神经营养蛋白是proNGF沿着大分子量NGF前体，每个组织表现出特征性的NGF表达模式。NT-3似乎经历了类似的加工过程，尽管它没有得到很好的研究。本项目的一个目标是使用NGF和NT-3 Western分析，将组织特异性NGF和NT-3表达模式与使用ELISA获得的蛋白质检测相关联，并确定两周的脑室内NGF体内输注的任何影响。此外，我们还利用真实的时间RT-PCR检测了周围神经节中的NGF和NT-3转录本，这两种转录本都受到外源性NGF和神经元活动的影响。本研究的主要目的是：1）研究交感神经节、感觉神经节和外周靶组织中NGF蛋白和mRNA的表达，并确定体内外源性NGF的任何影响; 2）确定外源性NGF对外周神经节和靶组织中NT-3蛋白和mRNA表达的影响; 3）阐明神经元活动在外周组织中NGF和NT-3表达中的作用;（4）研究交感神经支配对外周靶点神经营养因子表达的调节作用。该项目的结果将有助于我们理解调节神经营养因子表达的复杂机制，从而促进神经元存活，并有助于确定衰老和疾病中发生的神经元死亡的因素。