7-Dehydrocholesterol-derived oxysterols in SLOS: role and therapy

7-脱氢胆固醇衍生的氧甾醇在 SLOS 中的作用和治疗

• 批准号: 8352944
• 负责人: Libin Xu
• 金额: $ 10.73万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-10 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8352944
• 关键词: 7-dehydrocholesterol; 7-dehydrocholesterol reductase; 7-ketocholesterol; AY9944; Affect; Alzheimer' s Disease; Animal Model; Antioxidants; Astrocytes; Autistic Disorder; Behavior; Bile Acid Biosynthesis Pathway; Bile Acids; Biocompatible Materials; Biological; Biological Assay; Biological Process; Biology; Blood; Brain; CYP7A1 gene; Cell Line; Cell model; Cells; Cellular biology; Cerebrotendinous Xanthomatosis; Charge; Chemical Structure; Chemicals; Child; Cholesterol; Cholesterol 7-alpha-Monooxygenase; Cholesterol Homeostasis; Chondrodysplasia Punctata; Collaborations; Combined Modality Therapy; Complementary therapies; Congenital Abnormality; Consultations; Defect; Development; Developmental Disabilities; Diagnostic Procedure; Disease; Effectiveness; Ensure; Environment; Enzymes; Fibroblasts; Free Radicals; Functional disorder; Gene Expression; Genes; Goals; High Pressure Liquid Chromatography; Human; Huntington Disease; Inborn Genetic Diseases; Individual; Institutes; Institution; Intellectual functioning disability; Ions; Knowledge; Laboratories; Lead; Light; Link; Lip structure; Lipid Peroxidation; Lipids; Liquid substance; Liver; Mass Spectrum Analysis; Mental Retardation; Mentors; Metabolic Diseases; Methodology; Mission; Modeling; Molecular; Molecular Biology; Mus; Mutation; National Institute of Child Health and Human Development; Neurologic; Neurons; Neurosciences; Outcome; Oxidoreductase; Parkinson Disease; Pathway interactions; Patients; Phase; Phenotype; Problem behavior; Process; Rattus; Relative (related person); Research; Resources; Rodent Model; Role; Sampling; Smith-Lemli-Opitz Syndrome; Solutions; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Supplementation; Techniques; Testing; Therapeutic; Therapeutic Intervention; Time; Tissues; Training; Universities; base; career; career development; cell growth; cholesterol biosynthesis; conventional therapy; cytotoxic; data acquisition; human disease; in vivo; inhibitor/antagonist; innovation; ion mobility; lipid biosynthesis; lipid metabolism; millisecond; nervous system development; nervous system disorder; neuron development; novel; novel therapeutic intervention; oxidation; skills; translational approach; two-dimensional; ward

DESCRIPTION (provided by applicant): The candidate. My postdoctoral research centered on rate and mechanism of lipid peroxidation as it is closely associated with a number of human neurological disorders, such as Alzheimer's, Parkinson's, Huntington's disease, etc. With my discovery that 7-dehydrocholesterol (7-DHC) is the most readily oxidizable lipid molecule known to date, my research focus shifted to Smith-Lemli-Opitz syndrome (SLOS) as markedly elevated levels of 7-DHC (along with decreased levels of cholesterol) were observed in tissues and fluids of SLOS patients. Twenty novel oxysterols were subsequently discovered as products of oxidation of 7-DHC in solution, in cell and in vivo. 7-DHC oxysterols formed in solution were found to be cytotoxic and induce deleterious gene expression changes in cells. My short-term objective during the K99 phase (Specific Aim 1) is to study the biological actions of the in vivo-formed 7-DHC oxysterols on gene expression and lipid profiles (lipidomes) in cellular models of SLOS while receiving training in cell and molecular biology in neuroscience and the cutting-edge ion mobility-mass spectrometry (IM-MS). My objective for the R00 phase (Specific Aims 2 and 3) is to expand the same set of studies to animal models of SLOS building on my existing and newly acquired skill sets. My long-term career goal is to apply my knowledge in chemical structure, reactivity, mechanism, synthesis, and analysis to understanding lipid-related biological processes and developing translational approaches to- ward human diseases involving abnormal lipid metabolism. The environment. My Mentoring Committee is composed of five outstanding mentors and collabora- tors/consultants with complimentary expertise in lipid peroxidation, neuroscience, mass spectrometry, lipidomics, SLOS, cholesterol metabolism, gene expression, etc. The training institution, Vanderbilt University, has rich intellectual and physical resources, including institutes such as Vanderbilt Institute of Chemical Biolo- gy (VICB) and Vanderbilt Kennedy Center that are closely related to the proposed research, a full line of core laboratories, and the designated Office of Career Development. VICB has a strong and collaborative group on lipid research, which is available for consultation and establishing new collaboration. Overall, the commitment from my Mentoring Committee and the institution, along with the rich academic environment at Vanderbilt, will ensure the successful implementation of my training plans and proposed research. The research. SLOS is an autosomal recessive metabolic disorder that is caused by an inborn error of cholesterol biosynthesis. SLOS manifests a broad spectrum of phenotypes including multiple congenital malformations, neurological defects, mental retardation, and behavior problems. Over 50% of the SLOS children display autism-like behavior. Conventional therapy of SLOS is cholesterol supplementation, but the outcomes are inconsistent and controversial. Studies that focus on 7-DHC-derived metabolites are lacking, which is the gap that the proposed research is expected to fill. The central hypothesis of this project is that 7-DHC-derived oxysterols are key causal agents in the underlying molecular and pathophysiological mechanisms of SLOS. In Specific Aims 1 and 2, gene expression will be assayed by qPCR and lipidomes will be analyzed by IM-MS in cell and/or animal models of SLOS to examine the biological activities of 7-DHC oxysterols. IM-MS is a rapid two-dimensional separation technique that resolves biomolecular ions on the basis of mobility drift time and mass-to-charge ratio within micro to milliseconds. Application of the IM-MS technique in lipidomic studies is innovative because this methodology requires minimum amount of biological materials and is efficient in sample processing and data acquisition. Specific Aim 3 focuses on developing therapeutic interventions of SLOS through the inhibition of the formation of 7-DHC oxysterols. As both free radical and enzymatic oxidation con- tribute to the formation of 7-DHC oxysterols in vivo, approaches to inhibit both pathways will be explored in a rat model of SLOS. Oxysterol levels, gene expression, and lipidome will be assayed to evaluate the effectiveness of these therapies. The proposed research is expected to contribute to the elucidation of the roles of 7-DHC-derived oxysterols in the pathophysiology of SLOS, ultimately lead to a rapid and thorough diagnostic method by examining blood lipidomes of SLOS patients with IM-MS and lay the groundwork for a combination therapy through inhibiting the formation of 7-DHC oxysterol while supplementing cholesterol. The knowledge on gene expression and lipidome and the therapeutic approaches generated from this study are expected to have significant impact on other diseases that are related to abnormal cholesterol biosynthesis or metabolism, such as X-linked dominant chondrodysplasia punctata (CDPX2), cerebrotendinous xanthomatosis (CTX), and autism. PUBLIC HEALTH RELEVANCE: The proposed research is expected to enrich our understanding of the roles of 7-dehydrocholesterol-derived oxysterols in the pathophysiology of Smith-Lemli-Opitz syndrome (SLOS) - a cholesterol biosynthesis disorder that affects nervous system development, and develop therapeutic approaches through the inhibition of the formation of these oxysterols. This project relates to the mission of NICHD toward understanding intellectual and developmental disabilities, particularly disorders of metabolism that affect brain function and development.

描述（由申请人提供）：候选人。我的博士后研究集中在脂质过氧化的速率和机制，因为它与许多人类神经系统疾病密切相关，如阿尔茨海默氏症，帕金森氏症，亨廷顿氏病等。随着我发现7-脱氢胆固醇（7-DHC）是迄今为止已知的最容易氧化的脂质分子，我的研究重点转移到Smith-Lemli-Opitz综合征（SLOS），因为在SLOS患者的组织和体液中观察到7-DHC水平显著升高（沿着胆固醇水平降低）。随后发现了20种新的氧化甾醇作为7-DHC在溶液、细胞和体内的氧化产物。7-发现在溶液中形成的DHC氧固醇具有细胞毒性，并诱导细胞中有害的基因表达变化。我在K99阶段的短期目标（具体目标1）是研究体内形成的7-DHC氧固醇对SLOS细胞模型中基因表达和脂质谱（脂质体）的生物学作用，同时接受神经科学细胞和分子生物学以及尖端离子迁移率质谱（IM-MS）的培训。我的R 00阶段（具体目标2和3）目标是基于我现有和新获得的技能，将同一组研究扩展到SLOS动物模型。我的长期职业目标是应用我在化学结构，反应性，机制，合成和分析方面的知识来理解脂质相关的生物学。 过程和发展的翻译方法，以病房人类疾病涉及异常脂质代谢。 环境保护我的导师委员会由五位优秀的导师和合作者/顾问组成，他们在脂质过氧化、神经科学、质谱、脂质组学、SLOS、胆固醇代谢、基因表达等方面具有互补的专业知识。培训机构范德比尔特大学拥有丰富的智力和体力资源，包括范德比尔特化学生物学研究所（VICB）和范德比尔特肯尼迪中心等与拟开展研究密切相关的研究所，全线核心实验室，以及指定的职业发展办公室。维也纳国际化学品理事会在脂质研究方面有一个强大的协作小组，可供咨询和建立新的合作。总的来说，我的导师委员会和机构的承诺，沿着在范德比尔特丰富的学术环境，将确保我的培训计划和拟议的研究的成功实施。 研究SLOS是一种常染色体隐性遗传的代谢性疾病，由胆固醇生物合成的先天性错误引起。SLOS表现出广泛的表型，包括多种先天性畸形、神经缺陷、精神发育迟滞和行为问题。超过50%的SLOS儿童表现出自闭症样行为。SLOS的常规治疗是补充胆固醇，但结果不一致且存在争议。缺乏关注7-DHC衍生代谢物的研究，这是拟议研究有望填补的差距。该项目的中心假设是7-DHC衍生的氧固醇是SLOS的潜在分子和病理生理机制中的关键致病因子。在特定目的1和2中，将通过qPCR测定基因表达，并通过IM-MS分析SLOS细胞和/或动物模型中的脂质体，以检查7-DHC氧固醇的生物活性。IM-MS是一种快速的二维分离技术，其基于迁移率漂移时间和质荷比在微米至毫秒内解析生物分子离子。IM-MS技术在脂质组学研究中的应用是创新的，因为这种方法需要最少量的生物材料，并且在样品处理和数据采集方面是有效的。具体目标3侧重于通过抑制7-DHC氧化固醇的形成来开发SLOS的治疗干预。由于自由基和酶促氧化均有助于体内7-DHC氧固醇的形成，因此将在SLOS大鼠模型中探索抑制这两种途径的方法。将测定氧固醇水平、基因表达和脂质组以评价这些疗法的有效性。 该研究将有助于阐明7-DHC衍生的氧化固醇在SLOS病理生理学中的作用，最终通过检查患有IM-MS的SLOS患者的血脂组来实现快速和彻底的诊断方法，并为通过抑制7-DHC氧化固醇的形成同时补充胆固醇的联合治疗奠定基础。从这项研究中产生的关于基因表达和脂质组的知识以及治疗方法预计将对与异常胆固醇生物合成或代谢相关的其他疾病产生重大影响，例如X连锁显性点状软骨发育不良（CDPX 2），腱性黄瘤病（CTX）和自闭症。 公共卫生相关性：拟议的研究预计将丰富我们对7-脱氢胆固醇衍生的氧固醇在Smith-Lemli-Opitz综合征（SLOS）病理生理学中的作用的理解-一种影响神经系统发育的胆固醇生物合成障碍，并通过抑制这些氧固醇的形成来开发治疗方法。该项目与NICHD的使命有关，目的是了解智力和发育残疾，特别是影响大脑功能和发育的代谢紊乱。