Choroid Plexus Multi-Sensory Cilia Regulate Production of Cerebrospinal Fluid

纤毛是以微管为基础的细胞突起，具有多种生物学功能，包括液体 运动、细胞运动、环境感知和信号转导。传统上， 大多数纤毛是根据纤毛超微结构、生物功能和纤毛的不同而分类的。 运动性，主要有初生纤毛和游动纤毛。初级纤毛的功能是 独立的感觉中枢，将细胞外刺激转化为细胞内信号通路，以及 活动的纤毛表现出协调的拍打，以产生定向的流体运动。脉络膜 神经丛上皮细胞含有调节脑脊液产生的多感觉性纤毛 (脑脊液)以支持神经元发育和生理。使用串联传输电子 显微镜和聚焦离子束扫描电子显微镜(FIB-SEM)，我们的初步 结果表明，脉络丛的多感觉纤毛代表了一种不同类型的纤毛， 表现出独特的超微结构特征，同时类似于初级纤毛和运动性纤毛的特征 纤毛。脉络丛纤毛发生缺陷导致脑积水，至少部分原因是脑脊液 生产过剩。脉络丛纤毛可能在Shh信号转导中发挥重要作用，如FoxJ1 在外植体培养中，缺陷性脉络丛纤毛不再对Shh处理有反应。我们发现 Shh信号和AQP1表达之间的功能联系。因此，我们假设 脉络丛纤毛是一种独特的多感官类型，它介导Shh信号调节脑脊液 生产，至少部分是通过调节水通道和离子转运体的表达。 在这里，使用先进的成像技术，小鼠遗传学，成像 研究，细胞生物学和分子生物学，我们建议研究纤毛的超微结构， 脉络丛多感觉性纤毛的发生机制及生物学功能。第一, 利用电子显微镜、FIB-SEM和超分辨率成像，我们将表征 脉络丛纤毛的超微结构及其在不同发育阶段的发育动力学 发育阶段。其次，我们将利用小鼠遗传学和基因组学研究来识别 并对脉络丛纤毛的纤毛发生机制进行了研究。最后，我们将阐明 动态脉络丛纤毛介导Shh信号转导的分子机制 调节脑脊液的产生。综上所述，拟议的研究将在结构和功能上 在脉络丛中定义了一种新型的多感觉性纤毛，并将对 调节脑脊液产生的分子基础。

Cilia are microtubule-based cellular protrusions with diverse biological functions, including fluid movement, cellular locomotion, environmental sensing, and signal transduction. Traditionally, most cilia are classified based on differences in ciliary ultrastructure, biological function, and ciliary motility, with primary cilia and motile cilia as the major categories. The primary cilia functions as solitary sensory hubs to transduce extracellular stimuli into intracellular signaling pathways, and the motile cilia exhibited coordinated beating to generate directional fluid movement. Choroid plexus epithelial cells contain multi-sensory cilia that regulate the production of cerebrospinal fluid (CSF) to support neuronal development and physiology. Using serial transmission electron microscopy (TEM) and focus ion beam scanning electron microcopy (FIB-SEM), our preliminary results suggest that the multi-sensory cilia of choroid plexus represent a distinct type of cilia, exhibiting unique ultrastructural features, while resembling aspects of both primary cilia and motile cilia. Defective ciliogenesis in choroid plexus causes hydrocephalus, at least in part, due to CSF overproduction. Choroid plexus cilia are likely to play an important role in Shh signaling, as FoxJ1 deficient choroid plexus cilia no longer respond to Shh treatment in explant culture. We discovered a functional connection between Shh signaling and Aqp1 expression. Hence, we hypothesize that choroid plexus cilia are a unique type of multi-sensory that mediate Shh signaling to regulate CSF production, at least in part, by regulating the expression of water channels and ion transporters. Here, using a combined approach of advanced imaging techniques, mouse genetics, imaging studies, cell biology and molecular biology, we propose to study the ciliary ultrastructures, ciliogenesis mechanisms and biological functions of the multi-sensory cilia of choroid plexus. First, using electron microscopy, FIB-SEM and super-resolution imaging, we will characterized the ultrastructure of choroid plexus cilia, and define their developmental dynamics at different developmental stages. Second, we will employ mouse genetics and genomics studies to identify and characterize the ciliogenesis machineries of choroid plexus cilia. Finally, we will elucidate the molecular mechanisms through which dynamic choroid plexus cilia mediate the Shh signaling to regulate CSF production. Taken together, the proposed studies will structurally and functionally define a new type of multi-sensory cilia in choroid plexus, and will generate important insights on the molecular basis for the regulation of CSF production.