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：
10392413
负责人：
Rocco George Gogliotti
金额：
$ 35.31万
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/10392413
关键词：
Acute Address Adverse effects Affect Agonist Alleles Alzheimer&apos s Disease Amygdaloid structure Apnea Autopsy Brain Brain Stem CHRM1 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 Mosaicism 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 TimeLine 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 mouse model neuropsychiatric disorder neurotransmission noradrenergic novel patient subsets positive allosteric modulator pre-clinical precision medicine preclinical development premature programs receptor receptor expression receptor function respiratory response small molecule social therapeutic target 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.

抽象的神经发育障碍RETT综合征（RTT）中MECP2的致病性质已闻名将近20年；但是，目前尚无可行的干预策略。导致缺乏的一个因素治疗选择是临床前发育过程中对雄性MECP2-/Y基因敲除小鼠的依赖，尽管 RTT几乎完全影响女性，这些女性是X连锁MECP2等位基因（MECP2 +/-）的镶嵌性的事实。此外，RTT患者很少有突变导致MECP2蛋白的损失，而不是错过或截断突变，使关键功能域造使肌电差。为了解决构造有效性的失败，我们从9个RTT患者尸检的小脑和运动皮层样品进行了RNA测序确定可能从转化相关性开始的潜在可药物目标。这种方法使我们专注于毒蕈碱乙酰胆碱受体（MACHR），其中5个亚型中有4个显着破坏表达。特别有趣的是MACHR1（CHRM1，M1）亚型，长期以来一直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尸检的皮质样品，以确认降低CHRM1表达是一种强大而高度的人类RTT病理生理学的渗透方面。然后，我们确定了M1阳性的给药变构调节器（PAM），VU0453595（VU595），显着改善了社会和呼吸道（APNEA） MECP2 +/-小鼠中的表型。在AIM 1中，我们建议通过测试M1的影响来扩展这些初步数据使用结构上不同的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尸检表达数据由MECP2突变归纳，然后观察到签名表达模式，不仅对于M1，而且对于实际上而言测试的所有临床前靶基因。由于基因表达的变化通常是目标选择的基本原理，并且在受体功能正常的情况下，神经传递的调节会增加不利影响，这些发现对RTT中的精确药物的需求具有重要意义。在 AIM 2，我们将使用带有常见RTT突变（T158M，R168X，R255X和R306C）的小鼠来确定是否可以使用表达模式来预测M1 PAM功效。我们将把这些实验与 RTT尸检样品的转录本和蛋白质组学分析，以量化全局基因表达模式 RTT患者亚群的髓质。最后，在我们现有的数据集中，我们考虑VU595对 apneas是一个显着的发现，这既是因为呼吸功能障碍都可以预测RTT和因为apneas代表了高度可翻译的结果度量。在AIM 3中，我们建议机械机械地通过与全身耦合和体内循环耦合，剖析M1在RTT呼吸表型中的作用 MECP2敲入小鼠中的伏安法实验，以确定M1 PAM的作用机理以及定义M1在RTT子群中的呼吸回路中的何处以及如何在呼吸道中发挥作用。