Receptor-mediated transport of lysosomal enzymes

受体介导的溶酶体酶转运

• 批准号: 7889723
• 负责人: WILLIAM S SLY
• 金额: $ 36.88万
• 依托单位: SAINT LOUIS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-06-01 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7889723
• 关键词: Address; Adrenergic Receptor; Adult; Beta-glucuronidase; Biochemical; Biological; Blood - brain barrier anatomy; Brain; Capillary Endothelial Cell; Cell Surface Receptors; Cell surface; Cells; Disease; Endocytosis; Enzymes; Epinephrine; Event; Exocytosis; Goals; Histocytochemistry; Histopathology; IGF Type 2 Receptor; Immunoelectron Microscopy; Knock-out; L-Iduronidase; Laboratories; Lysosomal Storage Diseases; Lysosomes; Measures; Mediating; Membrane; Modeling; Molecular Genetics; Mucopolysaccharidosis I; Mucopolysaccharidosis I H; Mucopolysaccharidosis Type VII mouse; Mucopolysaccharidosis VII; Mus; Neuraxis; Neurons; Phosphorylation; Plasma; Receptor Mediated Signal Transduction; Research; Resistance; Route; Site; Technology; Transferrin; Transferrin Receptor; Transgenic Mice; Up-Regulation; enzyme model; enzyme replacement therapy; luminal membrane; macrophage; mannose 6 phosphate; metaperiodate; mouse model; neonate; novel; novel therapeutic intervention; public health relevance; receptor; transcytosis; uptake

DESCRIPTION (provided by applicant): Delivery of enzyme across the blood-brain barrier to correct neuronal storage represents a major unmet need since nearly 90% of lysosomal storage diseases involve the central nervous system and conventional enzyme replacement therapy does not correct storage in the brain. The broad goal of this research is to continue studies of newly discovered routes of transport of lysosomal enzymes to brain and their relevance to correcting neuronal storage by enzyme replacement therapy. We will use 2- glucuronidase and 1-iduronidase as model enzymes and murine mucopolysaccharidosis type VII (MPS VII; Sly disease) and MPS I (Hurler disease) as model lysosomal storage diseases. We seek to capitalize on recent breakthroughs addressing correction of neuronal storage, including: 1) The discovery that mannose 6-phosphate (M6P) mediated transcytosis (endocytosis at the luminal membrane followed rapidly by exocytosis at the abluminal membrane without going through the lysosome) can be upregulated pharmacologically in adult mouse brain to allow transport of enzyme across the blood-brain barrier comparable to that seen in the neonate; 2) The discovery of a novel route for chemically modified enzyme to correct neuronal storage when maintained at a high circulating level in plasma over a sustained period; and, 3) The findings that resistant sites not accessible to native enzyme can be targeted successfully using chimeric enzymes that target other cell surface receptors. We have four Specific Aims: 1) Determine the mechanism and significance of pharmacological upregulation of M6P receptor mediated transcytosis of lysosomal enzymes across the blood-brain barrier. 2) Determine the mechanism, efficacy, and generality of neuronal correction by periodate (PerT) modified enzyme. 3) Determine the efficacy of transferrin-iduronidase and transferrin-2-glucuronidase chimeric enzymes in crossing the BBB and correcting neuronal storage in murine MPS I and MPS VII mouse models. We will use a variety of biochemical, cell biological, immunological, and molecular genetic approaches and take advantage of novel mouse models of MPS VII produced in our laboratory by transgenic and mouse knockout technologies. We combine histochemistry, histopathology, and immunoelectron microscopy to measure enzyme delivery to brain and other resistant sites of storage. The answers sought have fundamental significance and should provide information leading to novel therapeutic approaches to enzyme replacement for lysosomal and other storage diseases involving the central nervous system. PUBLIC HEALTH RELEVANCE: We seek to address a major unmet need in lysosomal disease research: delivering enzyme to brain to correct neuronal storage, which occurs in 90% of these diseases. We will use a variety of biochemical, cell biological, immunological, and molecular genetic approaches and take advantage of novel mouse models of MPS VII produced in our laboratory by transgenic and mouse knockout technologies. The answers sought have fundamental significance and should provide information leading to novel therapeutic approaches to enzyme replacement for lysosomal and other storage diseases involving the central nervous system.

描述（由申请人提供）：通过血脑屏障输送酶以纠正神经元储存是一个未满足的主要需求，因为近 90% 的溶酶体储存疾病涉及中枢神经系统，而传统的酶替代疗法不能纠正大脑中的储存。这项研究的总体目标是继续研究新发现的溶酶体酶向大脑的转运途径及其与通过酶替代疗法纠正神经元储存的相关性。我们将使用 2-葡萄糖醛酸酶和 1-艾杜糖醛酸酶作为模型酶，并使用鼠粘多糖贮积症 VII 型（MPS VII；Sly 病）和 MPS I（Hurler 病）作为模型溶酶体贮积病。我们寻求利用最近在纠正神经元储存方面的突破，包括：1）发现6-磷酸甘露糖（M6P）介导的转胞吞作用（管腔膜上的胞吞作用，随后迅速在管腔膜上的胞吐作用，而不通过溶酶体）可以在成年小鼠大脑中药理学上调，以允许酶穿过血脑屏障的运输 与新生儿的情况相当； 2) 发现化学修饰酶在血浆中持续保持高循环水平时纠正神经元储存的新途径； 3) 研究发现，使用靶向其他细胞表面受体的嵌合酶可以成功靶向天然酶无法到达的抗性位点。我们有四个具体目标：1) 确定 M6P 受体介导的溶酶体酶跨血脑屏障转胞吞作用的药理学上调机制和意义。 2) 确定高碘酸盐（PerT）修饰酶神经元校正的机制、功效和普遍性。 3) 确定转铁蛋白-艾杜糖醛酸酶和转铁蛋白-2-葡萄糖醛酸酶嵌合酶在穿过 BBB 和纠正小鼠 MPS I 和 MPS VII 小鼠模型中神经元储存中的功效。我们将使用各种生化、细胞生物学、免疫学和分子遗传学方法，并利用我们实验室通过转基因和小鼠敲除技术生产的新型 MPS VII 小鼠模型。我们结合组织化学、组织病理学和免疫电子显微镜来测量酶向大脑和其他抗性储存位点的输送。寻求的答案具有根本意义，应该提供信息，从而为涉及中枢神经系统的溶酶体和其他贮积病的酶替代疗法提供新的治疗方法。 公共健康相关性：我们寻求解决溶酶体疾病研究中未满足的主要需求：将酶输送到大脑以纠正神经元储存，这种情况发生在 90% 的此类疾病中。我们将使用各种生化、细胞生物学、免疫学和分子遗传学方法，并利用我们实验室通过转基因和小鼠敲除技术生产的新型 MPS VII 小鼠模型。寻求的答案具有根本意义，应该提供信息，从而为涉及中枢神经系统的溶酶体和其他贮积病的酶替代疗法提供新的治疗方法。