Investigating role of maternal gut microbiome in microglia-neuron dynamics and development of somatosensory circuits

项目摘要 感觉加工障碍与神经发育障碍如自闭症谱系障碍有关 和智力残疾，每20名儿童中就有1名受到影响。越来越多的证据表明， 强烈影响神经发育障碍的发病机制，提示子宫内因素，如 母体肠道微生物群对胎儿大脑发育具有深远的影响。因此，理解角色 母体肠道微生物在神经回路和异常行为发育中的作用可以为以下方面提供见解： 神经发育障碍的潜在机制最近的研究阐明了 发生在妊娠期间，由此母体肠道微生物群的缺乏产生具有改变的胎儿发育的后代。 大脑基因表达、胎儿丘脑皮质轴突发育减少和触觉感觉行为异常 在以后的生活中。这项提案旨在探索母体肠道微生物群如何改变胎儿大脑发育。目标1 (K99)，母体肠道微生物组在产前小胶质细胞发育中的作用将由以下因素决定： 小胶质细胞基因表达的单细胞RNA测序、小胶质细胞形态学和体内微生物学成像 在小胶质细胞功能的体感行为期间清醒动物的成像。本提案的目标2（K99） 将采用从无特定病原体（SPF）的胚胎小胶质细胞中去除和新的“添加回”方法， 将具有正常肠道微生物群的大脑植入无菌母鼠后代的胚胎大脑中 (GF)或抗生素处理的（ABX），其耗尽母体肠道微生物组。这组实验将 解决小胶质细胞的因果作用，并测试产前小胶质细胞是否介导母体肠道微生物组的影响 对大脑发育的影响由于小胶质细胞激活与自闭症谱系中的行为缺陷有关， R00将利用K99阶段开发的技术来询问母亲是否患有精神分裂症， 肠道微生物群有助于小胶质细胞激活对胎儿大脑发育和后期生活的影响 行为。这些目标的成功完成可能会导致新的生物靶点的治疗 干预，同时也扩大了我们对中枢神经系统发育过程中微生物的理解 系统这些拟议的实验将为我提供新的方法学培训（单细胞RNA 测序和分析，以及清醒行为动物的体内成像）和概念（小胶质细胞生物学）， 作为一个独立研究实验室的基础，该实验室将研究母体肠道微生物， 神经免疫发育，并阐明细胞和分子机制， 神经发育障碍这项工作将在加州大学洛杉矶分校完成，那里的技术和 智力增长是不可胜数。我将定期参加与导师和合作者的会议， 实验设计反馈和职业建议。我将参加加州大学洛杉矶分校的研究报告撰写和研究研讨会， 同时也通过在科学会议上演讲来提高我的沟通技巧。在一起，这个职业 发展奖将帮助我建立和领导一个成功的神经发育生物学研究小组。

Project Summary Sensory processing disorder is associated with neurodevelopmental disorders such as autism spectrum disorder and intellectual disability, affecting 1 in 20 children. Increasing evidence reveal that the maternal environment strongly impacts the etiopathogenesis of neurodevelopmental disorders, suggesting in utero factors such as the maternal gut microbiota holds profound influence on fetal brain development. Therefore, understanding the role of maternal gut microbes in the development of neural circuits and abnormal behaviors can provide insights to the underlying mechanisms of neurodevelopmental disorders. Recent work has illuminated mechanisms that occur during gestation whereby the absence of the maternal gut microbiota yields offspring with altered fetal brain gene expression, reduced fetal thalamocortical axon development, and abnormal tactile sensory behavior in later life. This proposal aims to explore how maternal gut microbiota alters fetal brain development. In Aim 1 (K99), the role of the maternal gut microbiome in the development of prenatal microglia will be determined by single-cell RNA sequencing of microglia gene expression, CLARITY imaging of microglia morphology and in vivo imaging of awake animals during somatosensory behaviors for microglia function. Aim 2 of this proposal (K99) will employ a depletion and novel “add-back” approach of embryonic microglia from specific pathogen-free (SPF) brains, which have a normal gut microbiota, into embryonic brains of offspring from dams that are germ-free (GF) or antibiotic-treated (ABX), which are depleted of the maternal gut microbiome. This set of experiments will address the causal role of microglia and test whether prenatal microglia mediate maternal gut microbiome effects on brain development. Since microglial activation is implicated in behavioral deficits seen in autism spectrum disorder and schizophrenia, R00 will leverage techniques developed in the K99 phase to ask whether maternal gut microbiota contributes to the effects of microglial activation on fetal brain development and later life behaviors. The successful completion of these aims could lead to new biological targets for therapeutic intervention, while also expanding our understanding of microbes during development of the central nervous system. These proposed experiments will provide me with new training in methodologies (single cell RNA sequencing and analysis, and in vivo imaging of awake behaving animals) and concepts (microglial biology) to serve as the foundation of an independent research laboratory that will study maternal gut microbes and neuroimmune development, and elucidate the cellular and molecular mechanisms governing neurodevelopmental disorders. This work will be completed at UCLA, where the opportunities for technical and intellectual growth are innumerable. I will attend regular meetings with mentors and collaborators to receive feedback on experimental design and career advice. I will attend grant writing and research seminars at UCLA, while also improving my communication skills by presenting at scientific conferences. Together, this career development award will help me establish and lead a successful neurodevelopmental biology research group.