Novel Probes for Studying Treatment of CNS-based Lysosomal Storage Diseases

用于研究基于中枢神经系统的溶酶体贮积病治疗的新型探针

• 批准号: 8481819
• 负责人: Scott D Larsen
• 金额: $ 64.18万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-01 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8481819
• 关键词: ABCB1 gene; Acute; Amines; Animal Model; Area; Attenuated; Biological Assay; Blood - brain barrier anatomy; Brain; Catabolism; Cells; Ceramide glucosyltransferase; Chronic; Cognitive; Development; Disease; Disease model; Dose; Drug Kinetics; Enzymes; G(M2) Ganglioside; Gangliosides; Gangliosidosis GM1; Gene Mutation; Glucosylceramides; Glycosphingolipids; Goals; Hemoglobin; In Vitro; Investigation; Kidney; Lead; Liver; Liver Microsomes; Longitudinal Studies; Lysosomal Storage Diseases; Lysosomes; Measurable; Measures; Medical; Metabolic; Metabolic Clearance Rate; Metabolism; Miglustat; Mission; Modeling; Motor; Mus; National Institute of Neurological Disorders and Stroke; Neutral Glycosphingolipids; Non-Neuronopathic Gaucher Disease; Outcome; P-Glycoprotein; Patients; Penetrance; Peripheral; Permeability; Phase II Clinical Trials; Phase III Clinical Trials; Plasma; Property; Proteins; Recombinant Proteins; Reporting; Rodent; Site; Sphingolipids; Spleen; Structure; Symptoms; Tartrates; Therapeutic; Thrombocytopenia; Time; Wild Type Mouse; Work; alkalinity; analog; base; clinical efficacy; design; effective therapy; enzyme replacement therapy; glycosphingolipidoses; imiglucerase; improved; in vitro Assay; in vivo; inhibitor/antagonist; innovation; lysosomal proteins; mouse model; nervous system disorder; novel; novel therapeutic intervention; pharmacophore; physical property; public health relevance; response; small molecule; treatment strategy

DESCRIPTION (provided by applicant): Lysosomal storage diseases (LSDs) result from genetic mutations in one of 42 different lysosomal proteins, 12 of which are involved in the enzymatic catabolism or degradation of sphingolipids and glycosphingolipids (GSLs). Although fully two-thirds of all LSDs have some CNS involvement that can result in progressive cognitive and motor decline, there are currently no effective therapies. There are, however, two effective approaches to treating LSDs in the periphery. The first is enzyme replacement therapy (ERT), in which the defective enzyme is supplemented with recombinant protein that has been terminally modified to be taken up into the lysosome. The second approach entails inhibition of GSL synthesis with small molecules (substrate reduction therapy or SRT), and this strategy has been clinically proven to be effective for the treatment of Gaucher type 1 disease. To date SRT has focused on inhibition of glucosylceramide (GlcCer) synthase, which catalyzes the first step in GSL synthesis. The only approved agent, miglustat, is a weak inhibitor which has limited efficacy only against Gaucher type 1 and possesses some off-target effects. A much more potent and selective inhibitor, eliglustat tartrate, is currently in phase 3 clinical trials for Gacher type 1 with reported efficacy superior to that of the ERT agent, imiglucerase. Unfortunately, eliglustat tartrate does not penetrate the CNS, so holds no promise for treating CNS-based LSDs. We recently demonstrated that a structural analog of eliglustat (CCG-203586), designed to be more CNS-permeable, was able to effect measurable reductions in GlcCer levels in the brains of mice. However, based on its close structural relationship to eliglustat, which is known to be rapidly metabolized in mice, it is unlikely that CCG-203586 will be an optimal probe for studying chronic inhibition of GSL synthesis in murine models of CNS-based LSDs. The overarching goal of this work will be to determine if SRT is an effective approach to ameliorating the symptoms of LSDs of the CNS. Our approach will be to: 1) optimize the CCG-203586 lead structure for metabolic stability and CNS-permeability without sacrificing potency, 2) evaluate the best new analogs for their degree of penetrance into the CNS of mice, and 3) select optimal probes for long-term studies in mouse models of the CNS-based LSDs: Sandhoff and Tay-Sachs. Our proposal is innovative in its use of physical property-based design to reduce recognition by efflux transporters (e.g. MDR1) at the blood brain barrier, and by the use of dual cell-based assays for GlcCer synthase inhibition that simultaneously measure both activity and recognition by MDR1. This work will be significant in allowing, for the first time, investigation o the effects of chronic inhibition of GlcCer synthase in the CNS on GSL dynamics and on development and progression of symptoms in animal models of CNS-based LSDs. Finally, the ultimate impact of our work will be progress toward the first therapy for an unmet medical need, viz. CNS-based glycosphingolipidoses.

描述(申请人提供)：溶酶体储存疾病(LSD)是由42种不同的溶酶体蛋白中的一种的基因突变引起的，其中12种涉及鞘磷脂和糖鞘脂(GSLS)的酶分解代谢或降解。尽管足足有三分之二的LSD患者与中枢神经系统有关，可能会导致进行性认知和运动能力下降，但目前还没有有效的治疗方法。然而，有两种有效的方法来治疗外围国家的LSD。第一种是酶替代疗法(ERT)，在这种疗法中，缺陷的酶被末端修饰的重组蛋白补充到溶酶体中。第二种方法需要用小分子抑制GSL的合成(底物减少疗法或SRT)，这一策略已被临床证明对治疗Gaucher 1型疾病有效。到目前为止，SRT一直专注于抑制葡萄糖神经酰胺合成酶(GlcCer)，该酶催化GSL合成的第一步。唯一被批准的药物是米卢斯特，是一种弱抑制剂，仅对Gaucher 1型有效，并具有一些非靶点作用。一种更有效和更具选择性的抑制剂，酒石酸立格列酯，目前正处于治疗Gacher 1型的3期临床试验中，据报道，其疗效优于ERT试剂imigucerase。不幸的是，酒石酸立格列他不能穿透中枢神经系统，因此没有希望治疗基于中枢神经系统的LSD。我们最近证明了一种结构类似的利格卢斯特(CCG-203586)，旨在提高中枢神经系统的渗透性，能够显著降低小鼠大脑中的GlcCer水平。然而，基于其与已知在小鼠体内快速代谢的伊立卢斯特的密切结构关系，CCG-203586不太可能成为研究中枢神经系统LSD小鼠模型中GSL合成的慢性抑制的最佳探针。这项工作的首要目标将是确定SRT是否是改善中枢神经系统LSD症状的有效方法。我们的方法将是：1)在不牺牲效力的情况下优化CCG-203586导线的代谢稳定性和中枢神经系统通透性，2)评估最佳的新类似物对小鼠中枢神经系统的穿透程度，3)选择最佳探针用于中枢神经系统LSD小鼠模型的长期研究：Sandhoff和Tay-Sachs。我们的方案是创新的，它使用基于物理特性的设计来减少外流转运体(例如MDR1)在血脑屏障上的识别，并使用基于双细胞的GlcCer合成酶抑制检测方法，同时测量MDR1的活性和识别。这项工作将有助于首次研究中枢神经系统GlcCer合成酶的慢性抑制对GSL动力学的影响，以及对中枢神经系统LSD动物模型中症状的发生和发展的影响。最后，我们工作的最终影响将是朝着未得到满足的医疗需求的第一种疗法取得进展，即。以中枢神经系统为基础的神经鞘糖脂。