Molecular profile of cranial motor neurons

描述（由申请人提供）：我们主要对运动神经元对肌萎缩性侧索硬化症（ALS）的特异性易感性感兴趣。肌萎缩侧索硬化症导致运动神经元的选择性变性，尽管导致肌萎缩侧索硬化症的因素也存在于其他通常对肌萎缩侧索硬化症有抵抗力的中枢神经系统神经元中。即使在运动神经元中，也存在不同程度的ALS易感性。例如，脑干的颅神经核i、IV和VI对ALS的抵抗力相对较强，而面神经核运动神经元则不可避免地屈服于变性。由于ALS中只有部分神经元退化，我们假设运动神经元的特定特征可能赋予易感性。识别和表征减少或增强运动神经元变性易感性的独特分子对于理解和最终治疗运动神经元疾病至关重要。沿着这些思路，了解特定运动神经元组的基因和蛋白质表达谱对于理解它们对运动神经元疾病影响的易感性至关重要。因此，我们建议在ALS小鼠模型正常小鼠和Cu/Zn超氧化物歧化酶（SOD1）突变小鼠中，采用微阵列和实时PCR方法进行基因谱分析，以鉴定颅运动神经元中独特表达的基因。这样的研究将使我们了解运动神经元的分子结构和功能，也将为研究运动神经元疾病的基因表达改变建立一个筛选系统。本研究的具体目的概述如下。

DESCRIPTION (provided by applicant): We are interested primarily in the specific susceptibility of motor neurons to Amyotrophic Lateral Sclerosis (ALS). ALS results in selective degeneration of motor neurons despite that factors contributing to ALS are also present in other CNS neurons that are generally resistant to ALS. Even among motor neurons there are differing degrees of susceptibility to ALS. For example, cranial nerve nuclei Ill, IV, and VI in the brainstem are relatively resistant to ALS, while facial nucleus motor neurons inevitably succumb to degeneration. Since only subsets of neurons degenerate in ALS, we hypothesize that there may be specific features of motor neurons that confer susceptibility. Identification and characterization of unique molecules that either diminish or enhance a motor neuron's vulnerability to degeneration are critical to understanding and eventually treating motor neuron diseases. Along these lines, knowledge of the gene and protein expression profiles of a specific motor neuron group is critical to understanding their susceptibility to the effects of motor neuron disease. Therefore, we propose to identify genes uniquely expressed in cranial motor neurons by gene profiling using microarray and real-time PCR methods in normal and Cu/Zn superoxide dismutase (SOD1) mutant mice, a mouse model of ALS. Such a study will allow us to understand the molecular architecture and function specific to motor neurons and also will establish a screening system for studying gene expression alterations in motor neuron diseases. The Specific Aims of this study are outlined below. Specific Aim 1. To identify motor neuron-specific gene expression by gene profiling. We will undertake cell sorting and laser capture microdissection to isolate mRNAs expressed in motor neurons of cranial motor nuclei. The genes expressed specifically in motor neurons will be identified and compared in normal and SOD1 mutant mice by DNA microarray and real-time PCR. Specific Aim 2. To define differential expression of motor neuron-specific genes in cranial motor nuclei of normal and SOD1 mutant mice. We will determine by in situ hybridization the expression patterns of motor neuron-specific genes in cranial motor nuclei identified in Specific Aim 1. Differential expression levels of these genes will be further quantified by real-time PCR.