Astroglia-Mediated Pathogenic Mechanisms in Fragile X Syndrome (FXS)

星形胶质细胞介导的脆性 X 综合征 (FXS) 致病机制

• 批准号: 10671282
• 负责人: Yongjie Yang
• 金额: $ 47.73万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-15 至 2028-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10671282
• 关键词: 3' Untranslated Regions; Acceleration; Affect; Astrocytes; Attenuated; Behavioral; Binding; Binding Sites; Biochemical; Brain; Cells; Data; Development; Disease; Down-Regulation; Electrophysiology (science); FMR1; Fragile X Syndrome; Funding; Gene Expression; Gene Silencing; Genes; Genetic; Genetic Transcription; Human; Hyperactivity; Hypersensitivity; Image; Impaired cognition; In Vitro; Inherited; Injections; Intellectual functioning disability; Length; Mediating; Mediator; Messenger RNA; MicroRNAs; Microglia; Molecular; Morphology; Mus; Neurons; Nucleotides; Oligodendroglia; Outcome; Pathogenesis; Pathogenicity; Pathway interactions; Phenotype; Play; Proteome; RNA-Binding Proteins; Regulation; Role; Seizures; Sensory; Signal Transduction; Specific qualifier value; Synapses; Translational Regulation; Translations; Untranslated RNA; Up-Regulation; Virus; autistic; behavioral phenotyping; conditional knockout; in vivo; mRNA Transcript Degradation; mRNA Translation; memory acquisition; messenger ribonucleoprotein; mouse genetics; nerve stem cell; neurotransmission; postnatal; postnatal development; repetitive behavior; response; social; software development; synaptic function; synaptogenesis; transcriptome

Abstract Fragile X syndrome (FXS) is one of the most common inherited intellectual disabilities (ID) that is caused by transcriptional silencing of the Fmr1 gene and loss of its encoded fragile X messenger ribonucleoprotein (FMRP). FXS manifests with cognitive impairment, hyperactivity/seizure, sensory hypersensitivity, and several autistic features such as repetitive behaviors and social withdraw. FMRP has been shown to be primarily a RNA- binding protein that regulates translation of many mRNAs. In the mammalian CNS, astroglial cells play active and diverse roles in modulating synaptogenesis and synaptic functions, especially during postnatal development. How the loss of FMRP affects astroglial development and functions, especially underlying molecular mechanisms, just begin to be understood. MicroRNAs (miRs) are a class of noncoding RNAs with a mature length of 20-25 nucleotides that primarily bind to the 3’UTR of target mRNAs to significantly modulate gene expression by either inhibiting mRNA translation or inducing mRNA degradation. Biochemical and genetic evidence in neurons have implicated important roles of miR pathways in FMRP-mediated translational regulation. Additionally, miRs play key roles in the specification of neural progenitor cells and oligodendrocyte and microglia developmental maturation. Surprisingly, how miRs are involved in astroglial development especially postnatal molecular and morphological maturation is essentially unknown. This represents a significant obstacle to better understand astroglia-mediated pathogenic pathways in FXS. Based on our preliminary results and progress we made during previous funding period in understanding the role of astroglia in FXS pathogenesis, in this renewal, we propose the following aims: Aim 1: Determine the roles of miR-128-3p in regulating postnatal astroglial development; Aim 2: Determine the pathogenic roles of increased astroglial miR-128-3p in FXS. We have generated astroglial miR-128 conditional knock-out (Astro- miR-128 CKO) and astroglial miR-128/Fmr1 double conditional knock-out (Astro-miR-128/Fmr1 DCKO) mice and have generated a large amount of preliminary data to support our rationales and to demonstrate feasibility for proposed aims. We will employ mouse genetics, primary astroglial cultures, electrophysiology, virus injections, confocal and immunoEM imaging, and behavioral approaches to complete these aims. Outcomes from this project will begin to define specific miRs that regulate postnatal astroglial molecular and morphological maturation. In addition, the analysis of FXS-relevant synaptic and behavioral phenotypes on Astro-miR-128/Fmr1 DCKO mice will potentially provide a new astroglial target to modulate FXS disease development, thus will significantly advance our understanding about astroglial mechanisms in FXS pathogenesis.

抽象的 脆性 X 综合征 (FXS) 是最常见的遗传性智力障碍 (ID) 之一，由 通过 Fmr1 基因的转录沉默和其编码的脆弱 X 信使核糖核蛋白的丢失 （FMRP）。 FXS 表现为认知障碍、多动/癫痫、感觉过敏和多种 自闭症特征，例如重复行为和社交退缩。 FMRP已被证明主要是RNA- 调节许多 mRNA 翻译的结合蛋白。在哺乳动物的中枢神经系统中，星形胶质细胞发挥着活跃作用 在调节突触发生和突触功能中发挥多种作用，特别是在出生后发育过程中。 FMRP 的缺失如何影响星形胶质细胞的发育和功能，特别是潜在的分子 机制，才刚刚开始被理解。 MicroRNA (miR) 是一类具有成熟结构的非编码 RNA 长度为 20-25 个核苷酸，主要与目标 mRNA 的 3’UTR 结合，显着调节基因 通过抑制 mRNA 翻译或诱导 mRNA 降解来表达。生化和遗传 神经元中的证据表明 miR 通路在 FMRP 介导的翻译调节中发挥重要作用。 此外，miR 在神经祖细胞、少突胶质细胞和小胶质细胞的规范中发挥着关键作用 发育成熟。令人惊讶的是，miRs 如何参与星形胶质细胞的发育，尤其是出生后的发育 分子和形态的成熟基本上是未知的。这对更好地开展工作构成了重大障碍 了解星形胶质细胞介导的 FXS 致病途径。 根据我们的初步结果和我们在上一个资助期间取得的进展，了解 星形胶质细胞在 FXS 发病机制中的作用，在此更新中，我们提出以下目标： 目标 1：确定 miR-128-3p 在调节出生后星形胶质细胞发育中的作用；目标 2：确定致病作用 FXS 中星形胶质细胞 miR-128-3p 增加。我们已经生成了星形胶质细胞 miR-128 条件敲除（Astro- miR-128 CKO) 和星形胶质细胞 miR-128/Fmr1 双条件敲除 (Astro-miR-128/Fmr1 DCKO) 小鼠 并生成了大量的初步数据来支持我们的理由并证明可行性 为拟议的目标。我们将采用小鼠遗传学、原代星形胶质细胞培养、电生理学、病毒注射、 共聚焦和免疫EM成像，以及完成这些目标的行为方法。由此产生的结果 该项目将开始定义调节出生后星形胶质细胞分子和形态的特定 miR 成熟。此外，还对 Astro-miR-128/Fmr1 上 FXS 相关的突触和行为表型进行了分析 DCKO 小鼠可能会​​提供一个新的星形胶质细胞靶点来调节 FXS 疾病的发展，从而 显着增进了我们对 FXS 发病机制中星形胶质细胞机制的理解。