Inducible Site-specific Expression of Mutant SOD1

描述（由申请人提供）：肌萎缩性侧索硬化症（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病例是家族性的（称为FALS），大约25%的FALS病例是由Cu/Zn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，突变体（MT） SOD杀死MN是因为毒性，而不是由于缺乏歧化酶活性。然而，这种毒性的基础仍不清楚，这种毁灭性致命疾病的有效治疗方法也不清楚。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发生MN疾病（MND），但MTSOD在神经元或星形胶质细胞中的限制性表达不能诱导MND。在这项提议中，我们假设MTSOD需要在胚胎生命早期在MN中表达以引起ALS表型。为了验证这一假设，我们将产生一种转基因小鼠，从胚胎早期开始在MN（和一些中间神经元）中选择性表达MTSOD。MTSOD的表达将是可诱导的，因此我们也将能够确定早期表达必须发生的时间以及这种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中表达一种荧光素酶报告基因，因此这些小鼠可以为带有标记MN的解离脊髓细胞培养提供来源，用于筛选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.