Yamanaka Koji, Boillee Severine, Roberts Elizabeth A, Garcia Michael L, McAlonis-Downes Melissa, Mikse Oliver R, Cleveland Don W, Goldstein Lawrence S B
Ludwig Institute for Cancer Research and Department of Medicine and Neuroscience, University of California at San Diego, La Jolla, CA 92093, USA.
Proc Natl Acad Sci U S A. 2008 May 27;105(21):7594-9. doi: 10.1073/pnas.0802556105. Epub 2008 May 20.
Dominant mutations in ubiquitously expressed superoxide dismutase (SOD1) cause familial ALS by provoking premature death of adult motor neurons. To test whether mutant damage to cell types beyond motor neurons is required for the onset of motor neuron disease, we generated chimeric mice in which all motor neurons and oligodendrocytes expressed mutant SOD1 at a level sufficient to cause fatal, early-onset motor neuron disease when expressed ubiquitously, but did so in a cellular environment containing variable numbers of non-mutant, non-motor neurons. Despite high-level mutant expression within 100% of motor neurons and oligodendrocytes, in most of these chimeras, the presence of WT non-motor neurons substantially delayed onset of motor neuron degeneration, increasing disease-free life by 50%. Disease onset is therefore non-cell autonomous, and mutant SOD1 damage within cell types other than motor neurons and oligodendrocytes is a central contributor to initiation of motor neuron degeneration.
普遍表达的超氧化物歧化酶（SOD1）中的显性突变通过引发成年运动神经元过早死亡而导致家族性肌萎缩侧索硬化症（ALS）。为了测试运动神经元疾病的发病是否需要运动神经元以外的细胞类型受到突变损伤，我们构建了嵌合小鼠，其中所有运动神经元和少突胶质细胞均表达突变型SOD1，其表达水平足以在普遍表达时导致致命的早发性运动神经元疾病，但这种表达是在含有数量不等的非突变、非运动神经元的细胞环境中进行的。尽管100%的运动神经元和少突胶质细胞内都有高水平的突变表达，但在大多数这些嵌合小鼠中，野生型非运动神经元的存在显著延迟了运动神经元变性的发作，使无病生存期延长了50%。因此，疾病发作是非细胞自主性的，运动神经元和少突胶质细胞以外的细胞类型中的突变型SOD1损伤是运动神经元变性起始的主要促成因素。
