Inducible Site-specific Expression of Mutant SOD1

描述(申请人提供)：肌萎缩侧索硬化症(ALS)是一种以运动神经元(MN)选择性丧失为特征的神经退行性疾病。大约10%的ALS病例是家族性ALS(称为FALS)，大约25%的FALS病例是由铜/锌超氧化物歧化酶1型(SOD1)突变引起的。有令人信服的证据表明，突变的(MT)SOD杀死MN是因为毒性而不是歧化酶活性的缺陷。然而，这种毒性的基础仍然不清楚，这种毁灭性致命疾病的有效治疗也是如此。令人惊讶的是，尽管携带MTSOD及其内源性启动子作为转基因的小鼠会患上MN病(MND)，但限制MTSOD在神经元或星形胶质细胞中的表达并不能诱发MND。在这项建议中，我们假设MTSOD需要在MN的胚胎生命早期表达才能导致ALS表型。为了验证这一假设，我们将产生一只转基因小鼠，从胚胎早期开始，在MN(和一些中间神经元)中选择性地表达MTSOD。MTSOD表达将是可诱导的，因此我们也将能够确定必须发生多早表达以及该表达必须持续多长时间才能杀死MN。此外，这些小鼠还将在MN中表达荧光素酶报告基因，这样小鼠就可以为分离的带有标记MN的脊髓细胞培养提供来源，用于筛选治疗ALS的有效药物。

DESCRIPTION (provided by applicant): Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the selective loss of motor neurons (MN). Approximately 10% of ALS cases are familial (known as FALS), and approximately 25% of FALS cases are caused by mutations in Cu/Zn superoxide dismutase type 1 (SOD1). There is convincing evidence that mutant (MT) SOD kills MN because of toxicity rather than a deficiency in dismutase activity. However, the basis for this toxicity remains unclear as does effective treatment for this devastating fatal disease. Surprisingly, although mice that carry MTSOD with its endogenous promoter as a transgene develop MN disease (MND), a restricted expression of MTSOD in neurons or astrocytes fails to induce MND. In this proposal, we hypothesize that MTSOD requires expression early in embryonic life in MN in order to cause an ALS phenotype. In order to test this hypothesis, we will generate a transgenic mouse that selectively expresses MTSOD in MN (and some interneurons) starting early in embryonic life. The MTSOD expression will be inducible so that we will also be able to determine how early expression must occur and how long this expression has to last in order to kill MN. In addition, these mice will also express a luciferase reporter gene in MN, so that the mice can provide a source for dissociated spinal cord cell cultures with tagged MN for use in screens for effective drugs in ALS.