OXYSTEROL BIOMARKERS FOR NIEMANN-PICK C DISEASE

描述（由申请人提供）：尼曼-皮克C1型（NPC1）疾病是一种罕见的进行性神经退行性疾病，其特征是内脏和中枢神经系统中胆固醇和其他脂质积累。发展NPC1疾病治疗方法的一个障碍是缺乏易于量化的结果措施来评估临床试验中治疗的疗效。通过广泛的代谢组学研究，我们在NPC1受试者中发现了胆固醇氧化产物（“氧甾醇”）生物标志物，这些生物标志物反映了氧化应激和未酯化胆固醇储存的独特交集，这是NPC1疾病的生化标志。这一提议验证了一个高度创新的假设，即氧甾醇生物标志物与其他胆固醇稳态标志物可以作为评估疾病改善疗法（例如，2-羟丙基- -环糊精，HP- - cd）对中枢神经系统胆固醇代谢的影响和监测疾病进展的结果指标。24(S)-HC几乎只在中枢神经系统的大神经元中合成，CSF胆固醇酯（CE）为指导给药和监测药物反应提供了潜在的定量、非侵入性指标。同样，我们之前已经发现NPC1受试者脑脊液中胆固醇-3′，5′，6′-三醇（“三醇”）升高，这将为HP- 3′- cd对神经元内胆固醇储存的影响提供信息。这一假设将在脑室内（ICV） HP- - cd的NPC1动物模型（Aim 1）、参加自然史研究的NPC1人类受试者和NIH临床中心（Aim 2）的ICV HP- - cd一期试验（Aim 2）中进行检验。该提案还将探讨利用三醇检测的异常受试者操作特征（ROC）来开发新生儿筛查的可能性，以早期识别NPC1患者，从而干预症状前患者（目的3）。提出的新生儿NPC1疾病筛查是一项创新，将是第一个用于非酶溶酶体疾病的筛查，也是第一个用于先天性固醇代谢错误的筛查。虽然该项目的目标是开发一种适合在全州或地区范围内实施的NPC1疾病的原型新生儿筛查，但用于提取和检测氧化甾醇的串联质谱方法可以很容易地扩展到在其他固醇疾病（例如Smith-Lemli-Opitz综合征）中积累的代谢物，从而允许在单一筛查的背景下对几种遗传性疾病进行多重筛查。本提案中的研究非常重要，因为我们解决了NPC1疾病的关键未满足的治疗和诊断需求。

DESCRIPTION (provided by applicant): Niemann-Pick type C1 (NPC1) disease is a rare, progressive neurodegenerative disorder characterized by accumulation of cholesterol and other lipids in the viscera and central nervous system. A barrier to the development of treatments for NPC1 disease is the lack of readily quantifiable outcome measures to evaluate efficacy of therapy in clinical trials. Through broad-based metabolomic efforts, we have discovered in NPC1 subjects cholesterol oxidation product ("oxysterol") biomarkers that reflect the unique intersection of oxidative stress and unesterified cholesterol storage - the biochemical hallmark of NPC1 disease. This proposal tests the highly innovative hypothesis that oxysterol biomarkers, together with other cholesterol homeostatic markers, can serve as outcome measures to assess the effect of disease-modifying therapies (e.g., 2-hydroxypropyl-�-cyclodextrin, HP-�-CD) on cholesterol metabolism in the CNS and to monitor disease progression. 24(S)-HC, which is synthesized almost exclusively in large neurons in the CNS, and CSF cholesteryl esters (CE) offer potential quantitative, non-invasive metrics to guide dosing and to monitor drug response. Likewise, cholestane-3�, 5�, 6�-triol ("triol"), which we have previously shown to be elevated in the CSF of NPC1 subjects, will inform with respect to the effect of HP-�-CD on intraneuronal cholesterol storage. This hypothesis will be tested in NPC1 animal models administered intracerebroventricular (ICV) HP-�-CD (Aim 1), and in NPC1 human subjects enrolled in a natural history study and in a Phase 1 trial for ICV HP-�-CD at the NIH Clinical Center (Aim 2). The proposal will also explore the possibility that the exceptional receiver operating characteristics (ROC) of the triol assay can be harnessed to develop a newborn screen to identify NPC1 patients earlier and thus intervene in pre-symptomatic patients (Aim 3). The proposed newborn screen for NPC1 disease is innovative and would be the first for a non-enzymatic lysosomal disorder, as well as the first for an inborn error of sterol metabolism. While the goal of this project is to develop a prototype newborn screen for NPC1 disease suitable for implementation at the statewide or regional level, the tandem mass spectrometry methods developed for extraction and detection of the oxysterols could be readily extended to metabolites that accumulate in other sterol disorders (e.g., Smith-Lemli-Opitz Syndrome), thereby permitting multiplexed screening for several inherited disorders within the context of a single screen. The studies in this proposal are highly significant because we address the critical unmet therapeutic and diagnostic needs of NPC1 disease.