miR-34/449 miRNAs regulate ciliogenesis and cerebrospinal fluid production in choroid plexus

miR-34/449 miRNA 调节脉络丛纤毛发生和脑脊液产生

基本信息

批准号：
9350418
负责人：
Lin He
金额：
$ 23.55万
依托单位：
UNIVERSITY OF CALIFORNIA BERKELEY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-09-15 至 2018-08-31
项目状态：
已结题

项目摘要

Project summary The choroid plexus is a highly vascularized, secretory tissue that protrudes into the brain ventricles, whose primary function is to produce cerebrospinal fluid (CSF). CSF provides nutritional and metabolic support for brain development and mediates efficient waste removal. Choroid plexus consists of an apical monolayer of ciliated epithelial cells that surround a stromal core of capillaries and connective tissues. Choroid plexus epithelial cells (CPECs) each forms one to two dozen cilia, which are microtubule-based organelles that project from the apical membrane. Emerging evidence has suggested the importance of cilia in choroid plexus development and function, as a connection has been established between a defective ciliogenesis in choroid plexus and the excessive CSF production in mice. Our preliminary studies identified a highly redundant miRNA family, miR-34/449 miRNAs, as the key regulators for CPEC ciliogenesis. The miR-34/449 family comprises six evolutionarily conserved, homologous miRNAs that are highly enriched in the ciliated CPECs. miR-34/449-deficient mice are characterized by reduced brain ventricle size, aberrant CPEC morphology and impaired brain development, suggesting a reduced CSF production due to defective choroid plexus functions. Interestingly, the earliest defect we can detect in miR-34/449-deficient choroid plexus is the aberrant ciliogenesis in CPECs, characterized by a significant increase of the cilium number per cell and a greater length of the axonemes. Given the functional importance of CPEC cilia in negatively regulating CSF production, we hypothesize that the miR-34/449 deficiency leads to excessive CPEC ciliogenesis, which represses CSF production and impairs brain development. Here, we propose to functionally characterize miR-34/449 miRNAs in CPEC ciliogenesis and CSF production, and to elucidate the underlying cellular and molecular mechanisms. Using genetic mouse models, choroid plexus in vitro culture, cell biology and molecular biology approaches, we will characterize the cellular and molecular defects in miR-34/449-TKO choroid plexus, and investigate the functional connection between CPEC cilia and choroid plexus function. We will also identify the key miR-34/449 targets that mediate CPEC ciliogenesis and CSF production. Our studies will not only reveal a highly robust regulatory mechanism for CPEC ciliogenesis, but also provide important insights into the functional importance of CPEC cilia in choroid plexus function.

项目概要脉络丛是一种高度血管化的分泌组织，伸入大脑脑室，其主要功能是产生脑脊液（CSF）。 CSF提供为大脑发育提供营养和代谢支持，并介导有效的废物清除。脉络丛由围绕基质的顶端单层纤毛上皮细胞组成毛细血管和结缔组织的核心。脉络丛上皮细胞（CPEC）各自形成一到两打纤毛，它们是从顶端伸出的基于微管的细胞器膜。新的证据表明纤毛在脉络丛中的重要性发育和功能，因为有缺陷的纤毛发生之间已经建立了联系脉络丛和小鼠脑脊液过量产生。我们的初步研究确定了高度冗余的 miRNA 家族 miR-34/449 miRNA，作为 CPEC 纤毛发生的关键调节因子。 miR-34/449 家族包含 6 个进化上保守的同源 miRNA，它们是纤毛CPEC高度富集。 miR-34/449 缺陷小鼠的特点是减少脑室大小、异常的 CPEC 形态和大脑发育受损，表明由于脉络丛功能缺陷导致脑脊液产生减少。有趣的是，最早我们可以在 miR-34/449 缺陷的脉络丛中检测到的缺陷是 CPEC 中异常的纤毛发生，其特征是每个细胞的纤毛数量显着增加，并且纤毛长度更长轴丝。鉴于 CPEC 纤毛在负调节 CSF 产生中的功能重要性，我们假设 miR-34/449 缺陷导致 CPEC 纤毛发生过度，这抑制脑脊液的产生并损害大脑发育。在这里，我们建议从功能上表征 CPEC 纤毛发生和 CSF 产生中的 miR-34/449 miRNA，并阐明潜在的细胞和分子机制。使用遗传小鼠模型，脉络丛体外培养、细胞生物学和分子生物学方法，我们将表征细胞和 miR-34/449-TKO脉络丛的分子缺陷，并研究其功能连接 CPEC 纤毛和脉络丛功能之间的关系。我们还将确定关键的 miR-34/449 靶标介导 CPEC 纤毛发生和 CSF 产生。我们的研究不仅会揭示高度 CPEC 纤毛发生的强有力的监管机制，同时也提供了重要的见解 CPEC 纤毛在脉络丛功能中的功能重要性。