权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Role of Norrin in synaptic biology during development, adulthood, and disease

Norrin 在发育、成年和疾病期间突触生物学中的作用

基本信息

批准号：
10593916
负责人：
Emily G Thompson
金额：
$ 1.66万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-03-07 至 2023-05-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10593916
关键词：
Acute Adult Affect Animals Astrocytes Behavioral Biology Blindness Blood Vessels Brain Brain Diseases Cells Central Nervous System Cerebral cortex Communication Complement Cytoskeleton Defect Development Developmental Process Disease Electrophysiology (science)Elements Environment Equilibrium Exhibits Failure Frequencies Functional disorder Genes Genetic Diseases Glutamates Goals Growth Heterogeneity Homeostasis Human Imaging Techniques Immunohistochemistry Impaired cognition In Vitro Intellectual functioning disability Knockout Mice Knowledge Length Ligands Link Maintenance Mediating Metabolic Microcephaly Molecular Biology Mus Mutation Myoclonus Neurodegenerative Disorders Neurodevelopmental Disorder Neurons Neurotransmitter Receptor Norrie&apos s disease Pathology Physiological Physiology Play Point Mutation Preparation Process Property Proteins Retina Role Seizures Signal Transduction Slice Synapses Therapeutic Time Tissues WNT Signaling Pathway cell type density experimental study humanized mouse in vivo in vivo imaging insight male molecular imaging mouse model multi-electrode arrays mutant neuron development novel patch clamp postnatal postnatal development postsynaptic presynaptic receptor receptor expression selective expression single-cell RNA sequencing synaptogenesis validation studies

项目摘要

PROJECT SUMMARY Neuronal synaptic connections are essential for executing the distinct tasks that are required for brain homeostasis and function. Disturbances to synaptic biology during development or in mature neuronal networks are a key hallmark of most neurodevelopmental disorders and neurodegenerative diseases, respectively. Thus, a better understanding of the mechanisms that govern the establishment and maintenance of synapses could provide new insights into the origins of these disorders and potential therapeutic opportunities. Extra-neuronal influences, whether via direct cellular contact or released proteins, have been demonstrated to be critical in governing synaptic physiology. Outside of the broad metabolic responsibilities that astrocytes fulfill in the brain during normal physiology, it is becoming increasingly clear that astrocytes are instrumental in modulating neuronal synaptic connections. Specifically, astrocytic interactions with neuronal synapses are increasingly implicated in 1) the establishment of proper synaptic connections and 2) dysfunctions that negatively impact synaptic biology. Our group was the first to document the involvement of alternative Wnt ligand, Norrin, in synaptic properties—a protein long associated with the X-linked genetic disorder Norrie Disease (ND). Namely, Norrin enhanced neuronal firing frequency and network connectivity in in vitro cultures and caused synaptic abnormalities in vivo in adult Norrin-null mice. However, the mechanistic basis of these findings remains unknown, as well as whether Norrin is important in synaptogenesis. Thus, the overall goal of this proposal is to define the role that Norrin plays in synaptic biology, including the establishment of these connections during development and maintenance in adulthood. Additionally, this study will be the first to use a humanized mouse model of ND to provide characterization of the inherent and synaptic properties of ND cortical neurons. These objectives will be pursued with murine models, including Norrin-null mice and human Norrin gene point mutation (V45E) mice. First, I will determine the physiological mechanism by which Norrin mediates enhanced neuronal firing frequency and connectivity using whole-cell patch clamp electrophysiology in in vitro and ex vivo preparations. Additionally, I will use molecular biology and imaging techniques to evaluate Norrin’s effect on synaptic neurotransmitter receptor expression. Secondly, I will investigate the involvement of Norrin in synaptogenesis by utilizing iDISCO, single-cell RNAseq, and RNAscope in the postnatal mouse brain. Using the V45E mice I will characterize the electrophysiological properties of cortical neurons in the mature ND brain. Lastly, utilizing high-content in vitro and in vivo imaging, real-time synaptic dynamics will be evaluated in conditions of functional and dysfunctional Norrin across the synaptogenesis period. This proposal will provide novel insights into Norrin-mediated synaptic modulation during development, normal physiology, and ND pathology. The fundamental understanding of this facet of synaptic biology will have broad implications for other neurodevelopmental and neurodegenerative diseases.

项目总结神经元突触连接是执行大脑所需的不同任务所必需的动态平衡和功能。发育期间或成熟神经元网络中对突触生物学的干扰分别是大多数神经发育障碍和神经退行性疾病的关键标志。因此，更好地了解支配突触建立和维持的机制可能会为这些疾病的起源和潜在的治疗机会提供新的见解。神经元外影响，无论是通过细胞直接接触还是通过释放的蛋白质，已被证明是关键的主宰突触生理学。除了星形胶质细胞在大脑中履行的广泛新陈代谢职责之外在正常生理过程中，星形胶质细胞参与调节的作用越来越明显。神经元突触连接。具体地说，星形细胞与神经元突触的相互作用越来越多。与1)建立适当的突触连接和2)产生负面影响的功能障碍有关突触生物学。我们的小组是第一个记录另一种Wnt配体Norrin参与突触特性-一种与X连锁遗传性疾病诺里病(ND)长期相关的蛋白质。也就是说，去甲肾上腺素增强体外培养神经元的放电频率和网络连通性并引起突触成年Norrin基因缺失小鼠体内的异常。然而，这些发现的机制基础仍然存在。未知，以及去甲肾上腺素是否在突触发生中起重要作用。因此，这项提案的总体目标是为了确定Norrin在突触生物学中所起的作用，包括这些联系的建立在成年期的发育和维持过程中。此外，这项研究将是第一次使用人源化ND小鼠模型提供ND固有和突触特性的特征皮质神经元。这些目标将通过包括Norrin零基因小鼠和人类在内的小鼠模型来实现 Norrin基因点突变(V45E)小鼠。首先，我将确定去甲肾上腺素的生理机制利用全细胞膜片钳电生理学调节增强的神经元放电频率和连接性在体外和体外制剂中。此外，我将使用分子生物学和成像技术来评估诺林对突触神经递质受体表达的影响。其次，我将调查利用iDISCO、单细胞RNAseq和RNAScope在出生后小鼠大脑中的突触发生中的去甲肾上腺素。利用V45E小鼠，我将表征成熟ND中皮质神经元的电生理特性大脑。最后，利用高含量的体外和体内成像，实时突触动力学将在在突触发生期间功能正常和功能失调的去甲肾上腺素的情况。这项提案将提供对Norrin在发育、正常生理和ND过程中介导的突触调节的新见解病理学。对突触生物学这一方面的基本理解将对其他神经发育和神经退行性疾病。