A precision medicine approach to Rett Syndrome

雷特综合症的精准医学方法

基本信息

批准号：
10613600
负责人：
Rocco George Gogliotti
金额：
$ 35.01万
依托单位：
LOYOLA UNIVERSITY CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-05-01 至 2025-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10613600
关键词：
Acute Address Adverse effects Affect Agonist Alleles Alzheimer&apos s Disease Amygdaloid structure Apnea Autopsy Brain Brain Stem CHRM1 gene CHRM4 gene Cell Nucleus Cerebellar Cortex Cessation of life Chemosensitization Chronic Clinical Clinical Trials Cognition Complement Coupling Data Data Set Desipramine Development Dose Failure Female Frequencies Functional disorder Gene Expression Gene Expression Profile Genes Genetic Goals Human Hyperventilation Hypoxia Impairment Intervention Knock-in Mouse Knockout Mice Link Location Mediating Methyl-CpG-Binding Protein 2 Missense Mutation Modeling Molecular Motor Motor Cortex Mus Muscarinic Acetylcholine Receptor Mutation Nature Neurodevelopmental Disorder Neurologic Dysfunctions Neurons Norepinephrine Outcome Outcome Measure Oxidative Stress Pathogenicity Pathway interactions Patients Pattern Periodicity Pharmacology Phase II Clinical Trials Phenotype Physiological Proteins Proteomics Reader Research Respiration Disorders Rett Syndrome Risk Risk Factors Role Safety Sampling Scanning Seizures Seminal Severities Severity of illness Signal Transduction Site Symptoms Synaptic plasticity Syndrome Temporal Lobe Testing Therapeutic Transcript Whole Body Plethysmography cell type cholinergic disabling symptom drug discovery druggable target experimental study genetic testing improved in vivo individual patient interest locus ceruleus structure male mosaic mouse model neuropsychiatric disorder neurotransmission noradrenergic novel patient subsets pharmacologic positive allosteric modulator pre-clinical precision medicine preclinical development premature programs receptor receptor expression receptor function respiratory response single nucleus RNA-sequencing small molecule social therapeutic target timeline transcriptome transcriptome sequencing virtual

项目摘要

ABSTRACT The pathogenic nature of MeCP2 in the neurodevelopmental disorder Rett syndrome (RTT) has been known for almost 20 years; however, there currently no viable intervention strategies. One contributing factor to the paucity of treatment options is the reliance on male Mecp2-/y knockout mice during preclinical development, despite the fact that RTT almost exclusively affects females, who are mosaic for the x-linked MECP2 allele (Mecp2+/-). Furthermore, RTT patients rarely have mutations that result in loss of MeCP2 protein, rather have missense or truncating mutations that render key functional domains hypomorphic. To address this failing in construct validity, we performed RNA-sequencing on cerebellar and motor cortex samples from 9 RTT patient autopsies to identifying potentially druggable targets which might begin from a place of translational relevance. This approach led us to focus on muscarinic acetylcholine receptors (mAChRs), where 4 of the 5 subtypes had significantly disrupted expression. Of particular interest was the mAChR1 (CHRM1, M1) subtype, which has long been considered a viable therapeutic target for neuropsychiatric diseases. Excitingly, we recently used 44 temporal cortex samples from RTT autopsies to confirm that decreased CHRM1 expression is a robust and highly penetrant aspect of RTT pathophysiology in humans. We then established that administration of an M1 positive allosteric modulator (PAM), VU0453595 (VU595), significantly improves social and respiratory (apnea) phenotypes in Mecp2+/- mice. In Aim 1, we propose to expand these preliminary data by testing the effects of M1 potentiation against a full battery of RTT-like phenotypes in mice, using structurally distinct M1 PAMs, acute and chronic dosing paradigms, and multiple modes of pharmacology. Interestingly, if RTT autopsy expression data is binned by MECP2 mutation, then signature expression patterns are observed, not only for M1 but for virtually all preclinical target genes tested. As changes in gene expression are often the rationale for target selection, and modulation of neurotransmission in contexts where receptor function is normal carries an increased risk for adverse effects, these findings have important implications regarding the need for precision medicine in RTT. In Aim 2, we will use mice carrying common RTT mutations (T158M, R168X, R255X, and R306C) to determine whether expression patterns can be used to predict M1 PAM efficacy. We will couple these experiment with transcript and proteomic analysis of RTT autopsy samples to quantify global gene expression patterns in the medulla of RTT patient sub-populations. Finally, of our existing data set, we consider the effect of VU595 on apneas to be a salient finding, both because respiratory dysfunction is predictive of early lethality in RTT and because apneas represent a highly translatable outcome measure. In Aim 3, we propose to mechanistically dissect the role of M1 in RTT respiratory phenotypes by coupling whole body plethysmography and in vivo cyclic voltammetry experiments in Mecp2 knock-in mice to determine the M1 PAM mechanism of action, as well as define where and how M1 functions in the respiratory circuit across RTT sub-populations.

抽象的 MeCP2 在神经发育障碍 Rett 综合征 (RTT) 中的致病性已为人所知近20年；然而，目前尚无可行的干预策略。造成匮乏的因素之一治疗选择的一个主要因素是在临床前开发过程中对雄性 Mecp2-/y 敲除小鼠的依赖，尽管事实上，RTT 几乎只影响女性，她们是 X 连锁 MECP2 等位基因 (Mecp2+/-) 的镶嵌体。此外，RTT 患者很少有导致 MeCP2 蛋白丢失的突变，而是有错义或截断使关键功能域亚态的突变。为了解决构造有效性的问题，我们对来自 9 名 RTT 患者尸检的小脑和运动皮层样本进行了 RNA 测序，识别潜在的可药物靶点，这可能从具有转化相关性的地方开始。这种做法使我们关注毒蕈碱乙酰胆碱受体 (mAChR)，其中 5 种亚型中的 4 种具有显着的表达中断。特别令人感兴趣的是 mAChR1 (CHRM1, M1) 亚型，该亚型长期以来一直被认为是被认为是神经精神疾病的可行治疗靶点。令人兴奋的是，我们最近使用了 44 个时间来自 RTT 尸检的皮层样本，以确认 CHRM1 表达的降低是一种稳健且高度人类 RTT 病理生理学的渗透方面。然后我们建立了 M1 阳性的管理变构调节剂 (PAM)，VU0453595 (VU595)，显着改善社交和呼吸（呼吸暂停） Mecp2+/- 小鼠的表型。在目标 1 中，我们建议通过测试 M1 的效果来扩展这些初步数据使用结构不同的 M1 PAM、急性和慢性给药范例和多种药理学模式。有趣的是，如果RTT尸检表达数据通过 MECP2 突变进行分箱，然后观察到特征表达模式，不仅对于 M1，而且对于虚拟的测试了所有临床前靶基因。由于基因表达的变化通常是目标选择的理由，并且在受体功能正常的情况下调节神经传递会增加以下风险：不良反应，这些发现对于 RTT 中精准医疗的需求具有重要意义。在目标 2，我们将使用携带常见 RTT 突变（T158M、R168X、R255X 和 R306C）的小鼠来确定表达模式是否可用于预测 M1 PAM 功效。我们将把这些实验与对 RTT 尸检样本进行转录本和蛋白质组分析，以量化体内的全局基因表达模式 RTT 患者亚群的髓质。最后，在我们现有的数据集中，我们考虑了 VU595 对呼吸暂停是一个显着的发现，因为呼吸功能障碍可以预测 RTT 中的早期死亡，并且因为呼吸暂停代表了一种高度可转化的结果测量。在目标 3 中，我们建议机械地通过耦合全身体积描记法和体内循环来剖析 M1 在 RTT 呼吸表型中的作用在 Mecp2 敲入小鼠中进行伏安法实验以确定 M1 PAM 的作用机制，以及定义 M1 在 RTT 亚群呼吸回路中的作用位置和方式。