Receptor-mediated transport of lysosomal enzymes

受体介导的溶酶体酶转运

• 批准号: 8245761
• 负责人: WILLIAM S SLY
• 金额: $ 36.51万
• 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/8245761
• 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）：由于近90%的溶酶体储存疾病涉及中枢神经系统，传统的酶替代疗法不能纠正大脑中的储存，因此通过血脑屏障输送酶来纠正神经元储存是一个主要的未满足的需求。本研究的广泛目标是继续研究新发现的溶酶体酶到大脑的运输途径及其与酶替代疗法纠正神经元储存的相关性。我们将以2-葡萄糖醛酸酶和1-糖醛酸酶作为模型酶，以小鼠粘多糖病VII型（MPS VII； Sly病）和MPS I （Hurler病）作为模型溶酶体贮积病。我们试图利用最近在纠正神经元储存方面的突破，包括：1)发现甘露糖6-磷酸（M6P）介导的胞吞作用（在腔膜上的胞吞作用，随后在腔膜上迅速胞出，而不经过溶酶体）可以在成年小鼠大脑中进行药理学上调，以允许酶通过血脑屏障运输，这与在新生儿中看到的情况相当；2)发现了化学修饰酶的新途径，当在血浆中持续保持高循环水平时，可以纠正神经元储存；3)利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耐药位点。我们有四个具体目的：1)确定M6P受体介导的溶酶体酶跨血脑屏障胞吞作用的药理学上调机制和意义。2)确定高碘酸盐（PerT）修饰酶对神经元校正的机制、功效和普遍性。3)测定转铁蛋白-依糖醛酸酶和转铁蛋白-2-葡萄糖醛酸酶嵌合酶在小鼠MPS I型和MPS VII型小鼠模型中穿越血脑屏障和纠正神经元储存的作用。我们将使用多种生化、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基因敲除技术生产的MPS VII的新型小鼠模型。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对大脑和其他耐药储存部位的递送。所寻求的答案具有根本意义，并应提供信息，导致新的治疗方法，酶替代溶酶体和其他储存疾病涉及中枢神经系统。