DNA Damage and Neurodegeneration in Cockayne Syndrome

科凯恩综合征中的 DNA 损伤和神经变性

• 批准号: 7252003
• 负责人: JAMES E CLEAVER
• 金额: $ 33.62万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7252003
• 关键词: Age of Onset; Amyotrophic Lateral Sclerosis; Animals; Apoptosis; B-Lymphocytes; Binding; Binding Proteins; Birth; CDKN1A gene; Cell Cycle; Cell Cycle Checkpoint; Cell Death; Cells; Cessation of life; Childhood; Chronic; Cockayne Syndrome; Collagen; DNA Damage; DNA Polymerase II; DNA Repair; DNA biosynthesis; Defect; Development; Disease; ERCC2 gene; ERCC3 gene; ERCC5 gene; ERCC6 gene; Event; Excision; Exhibits; Fibroblasts; Figs - dietary; Galium; Gene Proteins; Genes; Genetic Transcription; Genome; Genomics; Human; Immunohistochemistry; Injury; Knockout Mice; Knowledge; Malignant Neoplasms; Modeling; Mouse Strains; Mus; Mutation; Nerve Degeneration; Neurodegenerative Disorders; Neurologic; Neurons; Nucleotide Excision Repair; Oxygen; Parkinson Disease; Pathology; Pathway interactions; Patients; Predictive Value; Predisposition; Proliferating; Proteins; Purkinje Cells; RNA; Range; Research Personnel; Rest; Role; Role playing therapy; Severities; Site; Symptoms; Syndrome; Testing; Therapeutic; Therapeutic Intervention; Tissues; Transcription-Coupled Repair; Transcriptional Regulation; Trichothiodystrophy; XPA gene; Xeroderma Pigmentosum; cancer risk; carcinogenesis; cell type; gene repair; helicase; human disease; improved; mouse model; neurodegenerative phenotype; nuclease; oncoprotein p21; oxidative DNA damage; progenitor; programs; progressive neurodegeneration; relating to nervous system; repaired; ubiquitin ligase; ultraviolet damage

DESCRIPTION (provided by applicant): Cockayne syndrome (CS) is a progressive childhood neurodegenerative disorder associated with a DNA repair defect. Two genes, CSA and CSB, are specifically involved in the CS disorder. These genes are involved in nucleotide excision repair (NER) of ultraviolet damage (UV) in transcriptionally active genes (transcription coupled repair, TCP). Cs-a and Cs-b mice have much milder neurological symptoms than human patients, but a greater risk for cancer that is not usually evident in humans. We have found that crossing Cs-b mice with Xp-c mice, that are defective in NER of nontranscribed regions of the genome, increases the severity and reduces the age of onset of neurodegeneration in animals that are homozygous or heterozygous in both genes but without necessarily compromising UV sensitivity. This has resulted in mouse strains that reflect the range of severity of human CS patients and can be used as models of neurodegeneration that we will compare in detail with the human syndrome. Not all the symptoms of CS patients are however easily related to repair deficiencies, so we hypothesize that there are additional pathways relevant to the disease particularly those that are downstream consequences of a common defect in ubiquitin ligase associated with the CSA and CSB gene products. We have found that the CSB defect results in altered expression of cell cycle and anti-angiogenic genes and proteins, and more programmed cell death that are relevant to the impaired development and progressive neurodegeneration. We therefore propose that, in Aim I, we will determine whether the mouse Cs-b x Xp-c crosses recapitulate the pathology of the human disease. We will determine the specific sites of programmed cell death and whether Purkinje cell loss is a primary event or due to loss of progenitor or associated cell types. We will determine whether neurodegeneration is consistent with premature cell cycle entry and apoptosis from chronic oxidative injury. In Aim II, we will examine global and transcription coupled repair in human CS cells and mouse fibroblasts from our mouse strains and differentiation-associated repair in mouse cells of neuronal origin following damage from reactive oxygen, to identify the contributions of these repair genes to neurodegeneration. In Aim III we will determine the roles played by protein targets of CS-dependent ubiquitylation that we have identified, especially those whose over-expression may have pathological consequences. We will emphasize those targets previously identified, such as p21 and collagen 15a1, for their roles in development and neurodegeneration. Successful conclusion of these studies will expand our knowledge of mechanisms of neurodegeneration and lay groundwork for development of therapeutic approaches for CS patients.

描述（由申请人提供）：科凯恩综合征（CS）是一种与 DNA 修复缺陷相关的进行性儿童神经退行性疾病。 CSA 和 CSB 这两个基因专门与 CS 疾病有关。这些基因参与转录活性基因中紫外线损伤 (UV) 的核苷酸切除修复 (NER)（转录偶联修复，TCP）。 Cs-a 和 Cs-b 小鼠的神经系统症状比人类患者轻得多，但患癌症的风险更大，而这在人类中通常不明显。我们发现，将 Cs-b 小鼠与基因组非转录区域 NER 有缺陷的 Xp-c 小鼠杂交，可以增加两个基因纯合或杂合的动物神经变性的严重程度并降低发病年龄，但不一定会损害紫外线敏感性。这产生了反映人类CS患者严重程度范围的小鼠品系，并且可以用作神经变性模型，我们将与人类综合征进行详细比较。然而，并非 CS 患者的所有症状都容易与修复缺陷相关，因此我们假设存在与该疾病相关的其他途径，特别是那些与 CSA 和 CSB 基因产物相关的泛素连接酶常见缺陷的下游后果。我们发现，CSB 缺陷会导致细胞周期和抗血管生成基因和蛋白质表达的改变，以及更多与发育受损和进行性神经变性相关的程序性细胞死亡。因此，我们建议，在目标 I 中，我们将确定小鼠 Cs-b x Xp-c 杂交是否能概括人类疾病的病理学。我们将确定程序性细胞死亡的具体位点，以及浦肯野细胞丢失是否是主要事件，还是由于祖细胞或相关细胞类型的丢失所致。我们将确定神经退行性变是否与细胞周期过早进入和慢性氧化损伤引起的细胞凋亡一致。在目标 II 中，我们将检查人类 CS 细胞和小鼠品系的小鼠成纤维细胞中的全局修复和转录偶联修复，以及活性氧损伤后神经元来源的小鼠细胞中的分化相关修复，以确定这些修复基因对神经退行性变的贡献。在目标 III 中，我们将确定我们已确定的 CS 依赖性泛素化蛋白靶点所起的作用，特别是那些过度表达可能产生病理后果的蛋白靶点。我们将强调先前确定的那些靶标，例如 p21 和胶原蛋白 15a1，因为它们在发育和神经退行性变中的作用。这些研究的成功完成将扩大我们对神经变性机制的了解，并为 CS 患者治疗方法的开发奠定基础。