NURR1 Gene Mutations in Parkinson's Disease

帕金森病中的 NURR1 基因突变

• 批准号: 6879217
• 负责人: WEIDONG LE
• 金额: $ 28.6万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-01 至 2007-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6879217
• 关键词: Parkinson' s disease; SDS polyacrylamide gel electrophoresis; cell line; clinical research; dopamine; family genetics; gene expression; gene mutation; genetic screening; genetic susceptibility; genotype; human genetic material tag; human tissue; molecular cloning; molecular pathology; neurons; phenotype; polymerase chain reaction; site directed mutagenesis; transfection

DESCRIPTION (provided by applicant): The search for genes that cause or contribute to Parkinson's disease (PD) has intensified since the discovery of alpha-synuclein gene and parkin gene mutations linked to patients with familial Parkinson's disease. NURR1 {the human homolog of roden nurr1), a member of the nuclear receptor super family, may be relevant to the disease since the gene is essential for induction and maintenance of nigra dopaminergic (DAergic) adenotype and heterozygous nurr1 knock-out mice display many features of parkinsonism with aging. To investigate if NURR1 is a susceptibility gene in Parkinson's disease we have performed a case-control study in over 200 PD patients. We have identified two novel variants in NURR1 gene (-291T deletion and -245T ->G substitution) in 10 of 107 proband familial Parkinson's disease (fPD), but not in sporadic PD (sPD, n=94) and age-and race-matched normal controls (NC, n=221). In pedigree analysis of the ten fPD families we have found that all PD patients but none of the non-PD family members have the NURR1 gene variations. A linkage study using 5 haplotype markers in 4 available fPD families suggested that at least two distinct haplotyes exist in these fPD families. Furthermore, we have constructed full-length human NURR1 gene encoding the two variants and demonstrated that the variant genes reduced NURR1 gene expression by >85% when transfected in human embryonic kidney cells HEK293 or in human neuroblastoma cells SH-5YSY. In addition, rate-limited DA synthesis enzyme tyrosine hydroxylase mRNA was significantly low in the SH-5YSY cells transfected with two variant genes. These data suggest that the variants in the NURR1 gene might be PD-related mutations. We, therefore, hypothesize that diminished expression of the NURR1 gene (loss of function), induced by the mutations in the gene, predisposing to DAergic neuron dysfunction, may represents a potentially important risk factor for Parkinson's disease. To test this hypothesis, we propose to study the relationship between the genotype of the mutations and the phenotype of the disease, and to investigate the underlying mechanisms. First (Aim 1), we will assay for the mutations, genotypes, and phenotypes in the first-degree members of all 10 fPD patients with the identified NURR1 mutations to determine the haplotype linkage, relationship between genotype and phenotype. Second (Aim 2), we will investigate if the mutations in NURR1 gene are specific for Parkinson's disease by analyzing the gene mutations in a total of 400 NC, 300 sPD, and 120 non-PD neurological disorders. Finally (Aim 3), we will determine the mechanisms by which the mutant genes alter NURR1 expression and DAergic neuronal dysfunction. The proposed experiments, which will take approximately four years for completion, will be conducted in parallel with a pilot study to generate a mouse model carrying the NURR1 mutations. The outcomes of the proposed study will improve our understanding of the role of NURR1 gene in the pathogenesis of Parkinson's disease, and may lead to potential therapeutic interventions, as well as means for diagnosing individuals having an increased risk of developing the disease.

描述（由申请人提供）：自从发现与家族性帕金森病患者相关的α-突触核蛋白基因和parkin基因突变以来，对导致或促成帕金森病（PD）的基因的搜索已经加强。 NURR1（啮齿类动物 nurr1 的人类同源物）是核受体超家族的成员，可能与该疾病有关，因为该基因对于诱导和维持黑质多巴胺能 (DAergic) 腺型至关重要，并且杂合 nurr1 敲除小鼠表现出许多症状。帕金森病随年龄增长的特征。为了调查 NURR1 是否是帕金森病的易感基因，我们对 200 多名帕金森病患者进行了病例对照研究。我们在 107 名先证者家族性帕金森病 (fPD) 中的 10 名中发现了 NURR1 基因的两个新变异（-291T 缺失和 -245T ->G 取代），但在散发性帕金森病 (sPD，n=94) 和年龄和种族中没有发现。 -匹配的正常对照（NC，n=221）。在对 10 个 fPD 家族的谱系分析中，我们发现所有 PD 患者但非 PD 家族成员均不具有 NURR1 基因变异。使用 4 个可用 fPD 家族中的 5 个单倍型标记进行的连锁研究表明，这些 fPD 家族中至少存在两种​​不同的单倍型。此外，我们构建了编码这两种变体的全长人NURR1基因，并证明当转染人胚肾细胞HEK293或人神经母细胞瘤细胞SH-5YSY时，变体基因使NURR1基因表达降低>85%。此外，在转染两种变异基因的SH-5YSY细胞中，限速DA合成酶酪氨酸羟化酶mRNA显着降低。这些数据表明 NURR1 基因的变异可能是 PD 相关突变。因此，我们推测，由基因突变引起的 NURR1 基因表达减少（功能丧失）容易导致 DAergic 神经元功能障碍，可能是帕金森病的潜在重要危险因素。为了检验这一假设，我们建议研究突变基因型与疾病表型之间的关系，并研究其潜在机制。首先（目标 1），我们将检测所有 10 名具有已确定的 NURR1 突变的 fPD 患者的一级成员的突变、基因型和表型，以确定单倍型连锁以及基因型和表型之间的关系。其次（目标 2），我们将通过分析总共 400 种 NC、300 种 sPD 和 120 种非 PD 神经系统疾病的基因突变来研究 NURR1 基因突变是否对帕金森病具有特异性。最后（目标 3），我们将确定突变基因改变 NURR1 表达和 DAergic 神经元功能障碍的机制。拟议的实验大约需要四年时间才能完成，将与生成携带 NURR1 突变的小鼠模型的试点研究同时进行。这项研究的结果将提高我们对 NURR1 基因在帕金森病发病机制中的作用的理解，并可能导致潜在的治疗干预措施，以及诊断患有该疾病的风险增加的个体的方法。