Gene Transfer and NMR Studies in Alpha-Mannosidosis Brain

α-甘露糖苷沉积症脑中的基因转移和核磁共振研究

• 批准号: 8068082
• 负责人: JOHN H WOLFE
• 金额: $ 9.96万
• 依托单位: CHILDREN'S HOSP OF PHILADELPHIA
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-06-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8068082
• 关键词: Affect; Aftercare; Age; Animals; Area; Biological Assay; Brain; Brain Diseases; Cells; Cellular Morphology; Child; Clinical; Clinical Trials; Complementary DNA; Development; Diffusion weighted imaging; Disease; Distal; Early treatment; Enzymes; Felis catus; Gene Delivery; Gene Expression; Gene Proteins; Gene Transfer; Genes; Grant; Gray unit of radiation dose; Histology; Human; Image; Inborn Genetic Diseases; Individual; Inherited; Injection of therapeutic agent; Lesion; Life; Ligands; Longitudinal Studies; Lysosomal Storage Diseases; Magnetic Resonance; Magnetic Resonance Imaging; Maps; Measures; Mediating; Mental Retardation; Messenger RNA; Methods; Modality; Modeling; Molecular Biology; Monitor; Mutation; Nature; Neurologic; Neurology; Normal Statistical Distribution; Nuclear Magnetic Resonance; Operative Surgical Procedures; Pathology; Pathway interactions; Physiological; Positron-Emission Tomography; Protons; Reporter Genes; Resolution; Rodent; Route; Serotyping; Site; Spectrum Analysis; Syndrome; Testing; Time; Tissues; Treatment Efficacy; Work; alpha Mannosidase B; alpha-Mannosidosis; brain cell; brain volume; cell type; clinically relevant; enzyme deficiency; gene therapy; gray matter; improved; neurogenetics; neurophysiology; public health relevance; research study; restoration; therapeutic gene; vector; white matter

DESCRIPTION (provided by applicant): Lysosomal storage diseases (LSDs) are a large group of inherited enzyme deficiencies that produce fatal degenerative syndromes in children, with most having severe brain disease manifest as mental retardation. Neurogenetic diseases have lesions throughout the brain, thus it is thought that global correction will be needed. Vector mediated transfer of a normal cDNA of the gene can correct defective cells, but current vectors mediate relatively limited gene delivery in the brain. Nevertheless, CNS gene therapy may work in most LSDs because the enzyme is secreted from genetically corrected cells and taken up by neighboring cells; and the enzyme may be transported via axonal pathways to distal sites. To study approaches to gene therapy in a brain that is significantly larger than a rodent brain, we will use a cat model of human alpha- mannosidosis (AMD), caused by a mutation in the lysosomal alpha-mannosidase (LAMAN) gene. In the current grant period we found: 1) An AAV1 serotype vector increased the amount of total gene transfer and it expanded transduction to both white and gray matter areas. 2) A single surgical procedure injecting the vector into several tracks spaced around the brain produced enough normal LAMAN to reverse large areas of storage lesions. Clinically, the treated AMD cats showed promising improvements in the neurological syndrome, but not complete resolution. 3) Several magnetic resonance (MR) modalities were evaluated to non-invasively monitor disease pathology in the living animal brain. Magnetization transfer imaging (MTI) showed that significant improvements in the white matter could be measured in AMD cat brains treated by gene therapy. Diffusion-weighted imaging (Dw-MRI) and spectroscopy (1H-MRS) were able to detect disease in the gray matter areas, where most of the storage is seen. 4) Pathology studies demonstrated significant restoration of normal brain cell morphology in treated cats, in both gray and white matter, but some regions of uncorrected disease remained. To improve on these advances, we propose in the continuation grant to: 1) Evaluate a method to monitor vector gene expression in the living brain by PET. 2) Investigate alternate vector delivery approaches to achieve more complete correction of the CNS. 3) Study the ability of Dw-MRI and 1H-MRS to measure changes in the gray matter after treatment, using a 3T clinical magnet. 4) Study long-term correction (>1 year), the effects of starting treatment earlier in life, and evaluate functional correlates of disease correction in neuro-physiological studies. Together, these experiments in a mammalian brain that is significantly larger than a rodent brain provide a robust translational model to study the potential of AAV-mediated gene therapy to correct the global brain lesions in neurogenetic LSDs. The translational nature of these studies involves a team of experts from several fields, including neurology, MRI and PET imaging, gene vector development, molecular biology, neurophysiology, and pathology. PUBLIC HEALTH RELEVANCE: The lysosomal storage diseases are a large group of inherited disorders that have severe disease in the brain. We are studying gene therapy methods to correct the brain disease. The proposed studies are directed towards improving gene and protein delivery sufficiently to make them feasible for human clinical trials.

描述（由申请人提供）：溶酶体储存疾病（LSD）是一大批遗传性酶缺陷，在儿童中产生致命的退化综合症，其中大多数患有严重的脑部疾病表现为智力低下。神经遗传疾病在整个大脑中都有病变，因此人们认为需要全球校正。载体介导的基因正常cDNA的转移可以纠正缺陷细胞，但是电流矢量介导了大脑中相对有限的基因递送。然而，中枢神经系统基因疗法在大多数LSD中可能起作用，因为该酶是从遗传校正细胞中分泌的并被相邻细胞吸收的。酶可以通过轴突途径传输到远端位点。为了研究明显大于啮齿动物大脑的大脑中基因疗法的方法，我们将使用由溶酶体α-甘露糖苷酶（Laman）基因突变引起的人α-甘露糖苷（AMD）的CAT模型。在当前的赠款期内，我们发现：1）AAV1血清型载体增加了基因转移的数量，并扩大了转导向白色和灰质区域。 2）将矢量注入围绕大脑间隔的几个轨道的单个外科手术，产生了足够的正常拉曼，以逆转大面积的储存病变。在临床上，经过治疗的AMD猫在神经系统综合征中表现出有希望的改善，但不能完全分辨。 3）评估了几种磁共振（MR）方式，以非侵入性监测活动物大脑中的疾病病理。磁化转移成像（MTI）表明，在通过基因治疗治疗的AMD猫大脑中可以测量白质的显着改善。扩散加权成像（DW-MRI）和光谱法（1H-MR）能够在看到大部分存储的灰质区域中检测疾病。 4）病理研究表明，在灰质和白质中，治疗猫中正常脑细胞形态的显着恢复，但未经矫正疾病的某些区域仍然存在。为了改善这些进步，我们建议在持续授权中提出：1）评估一种通过PET监测活体大脑中向量基因表达的方法。 2）研究替代矢量输送方法，以实现对中枢神经系统的更完整校正。 3）研究使用3T临床磁铁，研究DW-MRI和1H-MR治疗后灰质变化的能力。 4）研究长期校正（> 1年），即早期开始治疗的影响，并评估神经生理学研究中疾病校正的功能相关性。总之，在哺乳动物大脑中明显大于啮齿动物大脑的这些实验提供了一个可靠的翻译模型，以研究AAV介导的基因疗法的潜力，以纠正神经遗传LSDS中的全球脑损伤。这些研究的翻译性质涉及来自多个领域的专家团队，包括神经病学，MRI和PET成像，基因载体发展，分子生物学，神经生理学和病理学。 公共卫生相关性：溶酶体储存疾病是大脑中患有严重疾病的大量遗传性疾病。我们正在研究纠正脑疾病的基因治疗方法。拟议的研究旨在充分改善基因和蛋白质递送，使其适用于人类临床试验。