Roles of the X-linked Intellectual Disability gene ZDHHC9 in White Matter formation

X连锁智力障碍基因ZDHHC9在白质形成中的作用

基本信息

批准号：
10354435
负责人：
Gareth Thomas
金额：
$ 42.02万
依托单位：
TEMPLE UNIV OF THE COMMONWEALTH
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-20 至 2024-02-29
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10354435
关键词：
Acyltransferase Address Adult Affect Axon Brain Diseases Cells Cellular Structures Cerebral Palsy Code Cognitive deficits Corpus Callosum Development Electrons Enzymes Epilepsy Event Genes Genetic Golgi Apparatus Human Image Impairment Intellectual functioning disability Knockout Mice Link Lipids Maintenance Mediating Methods Microscopic Mining Modeling Molecular Morphology Mutation Myelin Myelin Basic Proteins Myelin Proteins Myelin Sheath Nervous System Trauma Nervous system structure Neuraxis Neurodevelopmental Deficit Neurodevelopmental Disorder Neurons Oligodendroglia Palmitates Patients Phenotype Process Prosencephalon Protein Isoforms Proteins Reporting Resources Role Seizures Techniques Time Viral Work X-linked intellectual disability base cell type dysmyelination experimental study in vivo insight knock-down loss of function loss of function mutation mutant myelination neuron loss oligodendrocyte lineage oligodendrocyte precursor palmitoylation precursor cell protein expression small hairpin RNA transcriptome sequencing white matter

项目摘要

Abstract: The myelin sheaths that wrap around axons in the Central Nervous System (CNS) are damaged or formed incorrectly in many developmental brain disorders. We thus sought to better understand the control of myelination and how it may be impaired in such conditions. Essentially all of the major myelin proteins are covalently modified with the lipid palmitate, a process that is often critical for correct protein subcellular localization and function, but how myelin protein palmitoylation is controlled is unknown. We were therefore struck by findings that the X-linked Intellectual Disability (XLID) gene ZDHHC9 codes for a specific palmitoyl acyltransferase enzyme that is highly expressed in oligodendrocytes (OLs), the myelinating cells of the CNS. Importantly, human patients with ZDHHC9 loss-of-function mutations and Zdhhc9 knockout (KO) mice display cognitive deficits and have markedly reduced forebrain white matter volume, suggesting a key role for ZDHHC9 in OL formation and/or function. Our own studies revealed that Zdhhc9 KO mice have impaired corpus callosal myelination without loss of neuronal axons and that Zdhhc9 knockdown cell-autonomously impairs OL maturation after differentiation from Oligodendrocyte Precursor Cells (OPCs) in culture. These striking phenotypes may account for the intellectual disability and/or epileptic seizures seen in human patients with ZDHHC9 mutations. In this project we will more precisely define links between Zdhhc9 mutation and myelination impairments. In Aim 1, we will combine well-established Electron Microscopic (EM) and immunostaining analyses with a genetic fate-mapping strategy to comprehensively define how Zdhhc9 loss impacts OL distribution and axonal myelination in vivo. In Aim 2 we will more precisely determine how cell- autonomous Zdhhc9 loss affects OL differentiation and morphological elaboration. In each Aim we will compare the ability of wild type (wt) and XLID mutant forms of ZDHHC9 to rescue the observed phenotypes. These studies will provide new insights regarding not just the impact of Zdhhc9 loss, but also palmitoylation- dependent control of myelination, a process first reported decades ago but about which almost nothing is known. Insights from this work could thus be invaluable to those studying a range of brain disorders marked by White Matter Impairments.

抽象的：中枢神经系统 (CNS) 中包裹轴突的髓鞘受损或形成在许多发育性脑部疾病中都是错误的。因此，我们试图更好地理解控制髓鞘形成以及在这种情况下髓鞘形成如何受到损害。基本上所有主要的髓磷脂蛋白都是用脂质棕榈酸酯进行共价修饰，这一过程对于正确的蛋白质亚细胞通常至关重要定位和功能，但如何控制髓磷脂蛋白棕榈酰化尚不清楚。我们因此 X 连锁智力障碍 (XLID) 基因 ZDHHC9 编码特定的棕榈酰基这一发现令人震惊酰基转移酶在少突胶质细胞 (OL)（中枢神经系统的髓鞘形成细胞）中高度表达。重要的是，携带 ZDHHC9 功能丧失突变的人类患者和 ZdhHC9 敲除 (KO) 小鼠表现出认知缺陷，并显着减少前脑白质体积，这表明 ZDHHC9 在 OL 形成和/或功能中的作用。我们自己的研究表明，Zdhhc9 KO 小鼠的功能受损胼胝体髓鞘形成，不损失神经元轴突，并且 Zdhhc9 细胞自主敲低在培养物中从少突胶质细胞前体细胞 (OPC) 分化后，会损害 OL 的成熟。这些引人注目的表型可能是人类患者出现智力障碍和/或癫痫发作的原因具有 ZDHHC9 突变。在这个项目中，我们将更精确地定义 Zdhhc9 突变和髓鞘形成障碍。在目标 1 中，我们将结合成熟的电子显微镜 (EM) 和使用遗传命运图谱策略进行免疫染色分析，以全面定义 Zdhhc9 丢失的方式影响体内 OL 分布和轴突髓鞘形成。在目标 2 中，我们将更精确地确定细胞如何自主 Zdhhc9 丢失影响 OL 分化和形态学阐述。在每个目标中，我们将比较 ZDHHC9 的野生型 (wt) 和 XLID 突变体形式拯救观察到的表型的能力。这些研究不仅将提供关于 Zdhhc9 丢失的影响的新见解，还包括棕榈酰化的影响—— 髓鞘形成的依赖性控制，这一过程在几十年前首次报道，但几乎没有任何报道已知。因此，这项工作的见解对于那些研究一系列脑部疾病的人来说是无价的。白质损伤。