Transcriptional regulation of multiciliate cell differentiation

描述（由申请人提供）：在许多器官系统中，投射数百根跳动纤毛的细胞（称为多纤毛细胞）产生沿着沿着腔表面运输生物材料的有力流体流。多纤毛细胞分布在呼吸道、生殖道和脑室中，它们产生的血流对人类健康有重要意义。尽管它们很重要，但这些细胞在不同上皮中形成的发育机制仍然未知。具体来说，多纤毛细胞分化可能是在转录密码的控制下，这是这种细胞类型形成所需的，但对这种密码的性质知之甚少。为了解决这个问题，拟议的实验集中在一个新发现的基因，称为Multicilin。Multicilin在初步实验中基于其在X.在胚胎中表达，但也在形成多纤毛细胞的其他器官中表达。在功能测试中，Multicilin是多纤毛细胞形成所必需的，并且当在胚胎的其他区域中错误表达时，更显着地将诱导异位多纤毛细胞的形成。Multicilin编码一个小蛋白，具有两个功能所需的结构域：一个中央卷曲螺旋结构域，类似于细胞周期调节因子Geminin中发现的结构域，以及转录活性所需的第二个C末端结构域。因此，所提出的实验将确定Multicilin是否通过调节细胞周期进程和激活多纤毛细胞分化所需的基因表达来促进多纤毛细胞的形成。此外，为了诱导多纤毛细胞分化，Multicilin促进锚数百纤毛所需的基体的大规模组装。通过促进多纤毛细胞特有的中心粒组装的新途径，Multicilin可以被利用来深入了解这个鲜为人知的过程。因此，Multicilin的分析结果将提供有关允许上皮祖细胞转变为多纤毛细胞的转录和细胞生物学事件的新信息。这些信息可能会加速设计从诱导干细胞或胚胎干细胞产生多纤毛细胞的方法，以及在通过转分化再生期间促进从其他细胞类型形成多纤毛细胞的方法的进展。 公共卫生相关性：多纤毛细胞通过在脑、肺和生殖道中产生流体流动而在人类健康中发挥重要作用，但对胚胎发育期间介导这些细胞形成的机制知之甚少。为了研究这些机制，拟议的研究将集中在一个新的基因，称为Multicilin，这是必要的和足够的，以促进多纤毛细胞的形成。分析Multicilin功能将有助于诊断和治疗影响纤毛上皮细胞的人类疾病，例如在原发性纤毛运动障碍和Kartegener综合征期间发生的纤毛缺陷。

DESCRIPTION (provided by applicant): In many organ systems, cells projecting hundreds of beating cilia, called multiciliate cells, produce a vigorous fluid flow that transports biological materials along luminal surfaces. Multiciliate cells populate the respiratory and reproductive tracts, and the ventricles of the brain, and the flow they produce has significant implications for human health. Despite their importance, the developmental mechanisms that underlie the formation of these cells in diverse epithelia are still unknown. Specifically, multiciliate cell differentiation is likely to be under the control of a transcriptional code that is required for this cell type to form, but little is known about the nature of this code. To address this issue, the proposed experiments focus on a newly discovered gene, called Multicilin. Multicilin was identified in preliminary experiments based on its highly restricted expression in multiciliate cells in X. laevis embryos, but is also expressed in other organs that form multiciliate cells. In functional tests, Multicilin is required for multiciliate cells to form, and more remarkably will induce the formation of ectopic multiciliate cells when misexpressed in other regions of the embryo. Multicilin encodes a small protein with two domains required for function: a central coiled-coil domain similar to the one found in the cell cycle regulator, Geminin, and a second C-terminal domain required for transcriptional activity. Thus, the proposed experiments will determine whether Multicilin promotes the formation of multiciliate cells by both modulating cell cycle progression and by activating gene expression required for multiciliate cell differentiation. In addition, in order to induce multiciliate cell differentiation, Multicilin promotes the large-scale assembly of basal bodies required to anchor hundreds of cilia. By promoting novel pathways of centriole assembly that are unique to multiciliate cells, Multicilin can be exploited to gain insight into this poorly understood process. Thus, the results from the analysis of Multicilin will provide new information about the transcriptional and cell biological events that allow epithelial progenitors to turn into multiciliate cells. This information will likely speed progress in devising approaches to generate multiciliate cells from stem cells, either induced or embryonic, and for promoting the formation of multiciliate cells from other cell types during regeneration via transdifferentiation. PUBLIC HEALTH RELEVANCE: Multiciliate cells play important roles in human health by generating fluid flow in the brain, lung and reproductive tract, but the mechanisms that mediate the formation of these cells during embryogenesis are poorly understood. To study these mechanisms, the proposed research will focus on a new gene, called Multicilin, which is both necessary and sufficient to promote multiciliate cell formation. Analyzing Multicilin function will aid in the diagnosis and treatment of human disease that affect ciliated epithelia, such as the ciliary defects that occurs during primary ciliary dyskinesia and Kartegener's syndrome.