Vision defects associated with loss of C-Vps function

与 C-Vps 功能丧失相关的视力缺陷

• 批准号: 9904696
• 负责人: Ryan Thummel
• 金额: $ 38.5万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9904696
• 关键词: Activities of Daily Living; Affect; Alleles; Animals; Autophagocytosis; Autophagosome; Axonal Transport; Blindness; Brain; C-terminal; Cell Culture Techniques; Cell Death; Cell physiology; Cells; Cessation of life; Child; Coculture Techniques; Complex; Cortical Blindness; Cues; Data; Defect; Deletion Mutation; Diagnostic; Disease; Endosomes; Exhibits; Failure; Family; Genes; Genetic; Genetic Diseases; Genetic Models; Genetic Predisposition to Disease; Genotype; Germ-Line Mutation; Goals; Human; Impaired cognition; Impairment; In Vitro; Individual; Intellectual functioning disability; Investigation; Lead; Leukoencephalopathy; Link; Lysosomes; Magnetic Resonance Imaging; Mammalian Cell; Mediating; Membrane; Metabolism; Modeling; Molecular; Mosaicism; Motor; Muscle hypotonia; Mutation; Myelin; Myelin Proteins; Nerve Degeneration; Neuraxis; Neurologic; Neurons; Neurophysiology - biologic function; Oligodendroglia; Optic Atrophy; Optic Nerve; Organelles; Outcome; Parents; Pathology; Pathway interactions; Patients; Phenotype; Physiological; Platelet Transfusion; Positioning Attribute; Process; Proteins; Public Health; Reporting; Research; Retina; Role; Structure of retinal pigment epithelium; Syndrome; System; Techniques; Tertiary Protein Structure; Testing; Tissues; Transgenic Organisms; Transplantation; Vision; Visual; Visual system structure; White Matter Disease; Yeasts; Zebrafish; cognitive development; disease diagnosis; embryo stage 2; follower of religion Jewish; human disease; in vivo; insight; leukodystrophy; mitochondrial metabolism; motor deficit; mutant; myelination; neuron loss; neuronal survival; novel; oligodendrocyte myelination; patient screening; peroxisome; protein degradation; protein transport; retinal apoptosis; sensory system; therapeutic target; trafficking; visual tracking; white matter

ABSTRACT Leukodystrophies (LD) and genetic Leukoencephalopathies (gLE) are genetic disorders affecting the white matter (myelin) in the central nervous system. LDs and gLEs progressively affect the motor and sensory systems, including the visual systems. Parents of affected children first note visual problems as a gradual loss in the ability of their child/children to track visual cues. Vision slowly worsens over subsequent years, likely due to the loss of myelin in the optic nerve and brain, termed cortical blindness. An MRI is typically diagnostic for myelination defects, but a clear diagnosis of disease-specific LDs and gLEs remains a challenge, and the majority of LDs and gLEs have an unknown genetic origin. We recently identified a mutation in VPS11 as a causative allele in the gLE phenotypes observed in five individuals from three unrelated Ashkenazi Jewish (AJ) families. Our analysis indicates a carrier rate of 1:250 AJ individuals. VPS11 functions in a complex of four C- VPS proteins, which are conserved from yeast to humans, and control critical cellular processes in the endolysosomal and autophagy pathways. These processes are only beginning to be investigated at the molecular level, mainly in yeast. Indeed, prior to our recent report, there were no known human mutations of any of the C-VPS proteins. However, we previously characterized a zebrafish vps11 mutant and have recently discovered that it shares many of the phenotypes of the human mutant, including defects in endolysosomal and autophagy pathways, myelination defects in the CNS, loss of retinal and CNS neurons, and motor defects. This proposal aims to take advantage of the zebrafish model to characterize the pathology underlying the vision loss associated with loss of C-Vps function. Aim 1 will further characterize the vision and motor defects associated with loss of Vps11 function in our zebrafish model and characterize the gLE phenotypes associated with loss of other C-Vps proteins. Aim 2 will analyze the intercellular consequences of the specific VPS11 mutation that underlies the gLE phenotypes and screen for compounds that will rescue the autophagy flux defects associated with this disease. Aim 3 utilizes a mammalian cell culture model to co-culture oligodendrocytes and neurons to test the role of VPS11 in myelin formation, which is the first investigation of VPS11 function in oligodendrocytes in any species. By combining mammalian in vitro techniques with the power of the zebrafish mutant model, the successful completion of these aims will significantly advance our long-term goal of elucidating the mechanism that underlies VPS11-mediated vision loss.

摘要 脑白质营养不良（LD）和遗传性脑白质病（gLE）是影响白色 中枢神经系统中的物质（髓磷脂）。LD和gLE逐渐影响运动和感觉 包括视觉系统。受影响儿童的父母首先注意到视力问题是逐渐丧失的 孩子追踪视觉线索的能力。在随后的几年里，视力缓慢下降，可能是由于 视神经和大脑中髓鞘的缺失，称为皮质盲。MRI通常用于诊断 髓鞘形成缺陷，但疾病特异性LD和gLE的明确诊断仍然是一个挑战， 大多数LD和gLE具有未知的遗传起源。我们最近在VPS 11中发现了一种突变， 在来自三个无关的德系犹太人（AJ）的五个个体中观察到gLE表型中的致病等位基因 家庭我们的分析表明携带率为1：250 AJ个体。VPS 11在四个C- VPS蛋白，从酵母到人类都是保守的，控制着细胞中的关键细胞过程。 内溶酶体和自噬途径。这些过程只是开始被调查， 分子水平，主要是在酵母中。事实上，在我们最近的报告之前，没有已知的人类突变， 任何C-VPS蛋白然而，我们先前描述了斑马鱼vps 11突变体的特征， 发现它具有人类突变体的许多表型，包括内溶酶体缺陷， 和自噬途径、CNS中的髓鞘形成缺陷、视网膜和CNS神经元的损失以及运动缺陷。 该提案旨在利用斑马鱼模型来表征潜在的病理学， 与C-Vps功能丧失相关的视力丧失。目标1将进一步描述视力和运动缺陷 与我们的斑马鱼模型中Vps 11功能丧失相关，并表征相关的gLE表型 其他C-Vps蛋白的缺失。目的2将分析特定VPS 11的细胞间后果 突变的基础gLE表型和筛选化合物，将拯救自噬通量 与这种疾病有关的缺陷。目的3利用哺乳动物细胞培养模型进行共培养 少突胶质细胞和神经元，以测试VPS 11在髓鞘形成中的作用，这是首次研究 VPS 11在任何物种的少突胶质细胞中发挥作用。通过将哺乳动物体外技术与 斑马鱼突变模型的力量，这些目标的成功完成将大大推进我们的研究。 长期目标是阐明VPS 11介导的视力丧失的机制。