Oxysterols in SLOS Neurodevelopment: Pathological Role and Therapy

氧甾醇在 SLOS 神经发育中的作用：病理作用和治疗

基本信息

批准号：
9363788
负责人：
Libin Xu
金额：
$ 38.98万
依托单位：
UNIVERSITY OF WASHINGTON
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-07-25 至 2022-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9363788
关键词：
7-dehydrocholesterol Affect Agonist Alkynes Animal Model Antioxidants Autistic Disorder Binding Proteins Biological Blood Blood - brain barrier anatomy Brain Brain Mass Cell model Cells Cerebrotendinous Xanthomatosis Chemistry Child Cholesterol Cholesterol Homeostasis Clinical Clinical Trials Congenital Abnormality Defect Development Diagnosis Disease Effectiveness Embryo Erinaceidae Fibroblasts Free Radicals Gene Expression Genes Goals Homeostasis Human Image Immunohistochemistry Inborn Genetic Diseases Individual Intellectual functioning disability K-Series Research Career Programs Knock-out Knockout Mice Knowledge Lead Lipids Liquid substance Mass Spectrum Analysis Mendelian disorder Methodology Mission Molecular Mus Mutation National Institute of Child Health and Human Development Neurodevelopmental Disorder Neurologic Neurons Outcome Oxidoreductase Pathogenesis Pathologic Pathway interactions Patients Permeability Phenotype Plasma Process Proteins Research Resolution Role Sampling Severities Simvastatin Smith-Lemli-Opitz Syndrome Spatial Distribution Specimen Sterols Supplementation Techniques Testing Tissues Work analog autistic behaviour base cholesterol biosynthesis conventional therapy cytotoxicity in vivo induced pluripotent stem cell ion mobility knock-down knockout animal mouse model nerve stem cell nervous system disorder neurodevelopment neurogenesis novel novel therapeutic intervention novel therapeutics oxidation premature relating to nervous system small molecule smoothened signaling pathway therapy development

项目摘要

Smith-Lemli-Opitz syndrome (SLOS) is a neurodevelopmental disorder that is caused by the most common inborn error of cholesterol biosynthesis at the step of 3β-hydroxysterol-Δ7-reductase (DHCR7). This defect leads to decreased levels of cholesterol and accumulation of its precursor, 7-dehydrocholesterol (7-DHC), in affected individuals. SLOS phenotype manifests as multiple congenital malformations, neurological defects, and autistic behavior. Conventional therapy for SLOS is supplementation of cholesterol, with or without simvas- tatin, but these approaches do not improve neurological defects in patients. Recent findings suggested oxida- tive metabolites of 7-DHC, oxysterols, are important contributors to the pathogenesis of SLOS, but the patho- logical roles of these oxysterols in SLOS neurodevelopment have not been systematically studied, which is the gap that this project is expected to fill. The central hypothesis is that 7-DHC-derived oxysterols are causative factors for neurodevelopmental defects in SLOS. The long-term goals of this project are to elucidate the con- sequences of disrupted cholesterol homeostasis during neurodevelopment and to develop therapies that can ameliorate the neurological defects. In Aim 1, mechanisms of action of 7-DHC-derived oxysterols in neurogen- esis will be elucidated using neural progenitor cells (NPCs) derived from WT and Dhcr7-knock out (KO) mice and from WT and SLOS human induced pluripotent stem cells (iPSCs). The effects of Dhcr7 KO on neurogen- esis will be compared with the effects of 7-DHC oxysterols. Protein targets of 7-DHC oxysterols will be pulled down using synthetic tagged analogs of these oxysterols. In Aim 2, consequences of 7-DHC oxysterols on neural development will be determined in vivo using WT and Dhcr7-KO mouse models. The effects of Dhcr7 KO and those of oxysterols on neurogenesis in vivo will be compared using immunohistochemistry. Temporal and spatial distribution of sterols, oxysterols, and other lipids in both WT and Dhcr7-KO brains will be analyzed by mass spectrometry (MS) techniques, such as high-resolution ion mobility-MS and imaging MS. In Aim 3, effectiveness of blood-brain-barrier-permeable small molecules against neurological defects in SLOS will be evaluated using animal models and NPCs derived from SLOS iPSCs. The hypothesis here is that neurological defects in SLOS can be ameliorated by inhibiting the formation of 7-DHC-derived oxysterols with antioxidants and/or counteracting their effects using agonists of Hedgehog (Hh) signaling pathway because some 7-DHC oxysterols antagonize Hh signaling. In addition, sterols, oxysterols, and other lipids in blood and fibroblast samples of SLOS patients from an ongoing antioxidant clinical trial will be characterized, aiming to identify bi- omarkers for assessing SLOS severity and therapy effectiveness. This project represents a new angle to understand the molecular mechanisms underlying the neurogenesis defects in SLOS and develop therapies for SLOS by targeting 7-DHC-derived oxysterols. The knowledge obtained from this project is expected to benefit other diseases associated with abnormal cholesterol biosynthesis or metabolism.

Smith-Lemli-Opitz 综合征 (SLOS) 是一种神经发育障碍，由最常见的 3β-羟基甾醇-Δ7-还原酶（DHCR7）步骤中胆固醇生物合成的先天性错误。导致胆固醇水平降低及其前体 7-脱氢胆固醇 (7-DHC) 的积累受影响的个体表现为多种先天畸形、神经缺陷、 SLOS 的传统疗法是补充胆固醇，有或没有 simvas-。 tatin，但这些方法并不能改善患者的神经缺陷。最近的研究结果表明，氧化- 7-DHC 的活性代谢物氧甾醇是 SLOS 发病机制的重要贡献者，但其发病机制这些氧甾醇在 SLOS 神经发育中的逻辑作用尚未得到系统研究，这是该项目有望填补这一空白，其核心假设是 7-DHC 衍生的氧化甾醇是致病原因。 SLOS 神经发育缺陷的因素该项目的长期目标是阐明神经发育过程中胆固醇稳态被破坏的序列，并开发可以改善神经缺陷在目标 1 中，7-DHC 衍生的氧甾醇在神经原中的作用机制- 将使用来自 WT 和 Dhcr7 敲除 (KO) 小鼠的神经祖细胞 (NPC) 阐明 esis 以及来自 WT 和 SLOS 人类诱导多能干细胞 (iPSC) 的 Dhcr7 KO 对神经原的影响。 esis 将与 7-DHC 氧化甾醇的效果进行比较。 7-DHC 氧化甾醇的蛋白质目标将被拉出。在目标 2 中，使用这些氧甾醇的合成标记类似物来降低 7-DHC 氧甾醇的影响。将使用 WT 和 Dhcr7-KO 小鼠模型在体内测定 Dhcr7 的影响。将使用免疫组织化学比较 KO 和氧甾醇对体内神经发生的影响。将分析 WT 和 Dhcr7-KO 大脑中甾醇、氧甾醇和其他脂质的空间分布通过质谱 (MS) 技术，例如高分辨率离子淌度 MS 和成像 MS 在 Aim 3 中，血脑屏障可渗透小分子对 SLOS 神经缺陷的有效性将是使用源自 SLOS iPSC 的动物模型和 NPC 进行评估。此处的假设是神经学。通过使用抗氧化剂抑制 7-DHC 衍生的氧甾醇的形成，可以改善 SLOS 的缺陷和/或使用 Hedgehog (Hh) 信号通路激动剂抵消其影响，因为某些 7-DHC 氧甾醇拮抗Hh信号此外，血液和成纤维细胞中的甾醇、氧甾醇和其他脂质。来自正在进行的抗氧化临床试验的 SLOS 患者样本将被表征，旨在识别双该项目代表了评估 SLOS 严重程度和治疗效果的新角度。了解 SLOS 神经发生缺陷的分子机制并开发治疗方法通过针对 7-DHC 衍生的氧甾醇进行 SLOS 预计将从该项目中获得的知识受益。与胆固醇生物合成或代谢异常相关的其他疾病。