Elucidation of molecular mechanisms of amyotrophic lateral sclerosis

本研究旨在阐明肌萎缩性侧索硬化症（ALS）神经退行性变的分子机制，并进一步制定ALS的治疗策略。该项目的重点是1。家族性ALS患者Cu/Zn SOD基因突变分析；2 .突变体Cu/Zn SOD蛋白构象变化分析；为家族性肌萎缩侧索硬化症创建转基因小鼠。在33个家族性ALS家族中，我们发现了SOD1基因的7个突变，包括3个新突变（Ala4Thr， Cys111Tyr和Glu133Stop）。通过突变体Cu/Zn SOD蛋白在COS细胞中的瞬时表达，我们在SDS-PAGE分析中发现突变体Cu/Zn SOD蛋白具有聚集形成和迁移改变的特性，支持突变体蛋白具有构象变化。我们已经建立了携带Ala4Thr和Ile113Thr的转基因小鼠系，其中Ile113Thr小鼠出现了后腿肌肉无力。基于本项目的研究成果，将进一步研究Cu/Zn SOD蛋白突变引起神经退行性变的分子机制。

This research was aimed to elucidate molecular mechanisms of neurodegeneration in amyotrophic lateral sclerosis (ALS), and, furthermore, to develop therapeutic strategies for ALS. The project focused on 1. detailed mutational analysis of Cu/Zn SOD gene in familial ALS, 2. analysis of conformational changes of mutant Cu/Zn SOD proteins, and 3. creation of transgenic mice for familial ALS. Among 33 families with familial ALS, we have identified 7 mutations in the SOD1 gene including 3 novel ones (Ala4Thr, Cys111Tyr and Glu133Stop). By transient expression of mutant Cu/Zn SOD proteins in COS cells, we have found that the mutant Cu/Zn SOD proteins possesses properties for aggregate formation and altered mobility on SDS-PAGE analysis, supporting that the mutant proteins have conformations changes. We have established transgenic mouse lines carrying Ala4Thr and Ile113Thr, of which Ile113Thr mice have developed muscular weakness in the hindlegs. Based on the accomplishments obtained through this project, molecular mechanisms of neurodegeneration caused by mutant Cu/Zn SOD proteins will further be investigated.