Mechanisms of microridge protrusion morphogenesis on mucosal epithelial cells

粘膜上皮细胞微嵴突起形态发生机制

• 批准号: 10330685
• 负责人: Alvaro Sagasti
• 金额: $ 38.18万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10330685
• 关键词: Achievement; Actins; Actomyosin; Apical; Biomechanics; Cell physiology; Cell surface; Cells; Cellular biology; Cornea; Cytokeratin filaments; Data; Dissection; Epithelial; Epithelial Cells; Future; Image; Infection; Intercellular Junctions; Intermediate Filaments; Length; Modeling; Molecular; Morphogenesis; Morphology; Mucous Membrane; Mucous body substance; Myosin ATPase; Oral cavity; Pattern; Periodicity; Process; Proteins; Research; Role; Skin; Structure; Study models; Surface; Surface Tension; Tissues; Work; Zebrafish; base; crosslink; experimental study; genetic regulatory protein; link protein; novel; scaffold

PROJECT SUMMARY Actin-based protrusions endow cells with a vast variety of forms. Cells on the surface of mucosal epithelial tissues, such as the cornea and mouth, often project elongated, wrinkle-like protrusions called microridges, which are arranged on apical surfaces in maze-like patterns. Microridges help these cells retain mucus, thus protecting vulnerable epithelial tissues from infection, abrasion and drying out. Until recently, almost nothing was known about microridge morphogenesis. Since microridge morphologies are distinct from those of better- studied protrusions, studying them could reveal fundamental new principles of protrusion morphogenesis. In recent years, the Sagasti lab established larval zebrafish skin cells as a model for studying microridge morphogenesis. This model enables powerful molecular manipulations and live imaging of morphogenesis. The Sagasti lab’s initial studies revealed several new discoveries, including: 1) The dissection of microridge morphogenesis into four molecularly separable steps, 2) the discovery that myosin contraction in the apical cortex regulates surface tension to permit microridge formation, 3) the identification of Plakin cytolinkers as master regulators of microridge length, 4) the discovery that keratin filaments are integral components of microridges required for their stability and elongation (the first example of intermediate filaments directly contributing to protrusion morphogenesis), and 5) the discovery that cortical myosin minifilaments orchestrate an unusual microridge fission/fusion rearrangement process that facilitates the formation of regular, periodic microridge arrangements on cell surfaces. Collectively, these discoveries have broad implications for how cortical myosin, cytolinkers, and intermediate filaments contribute to protrusion morphogenesis. Building on these achievements and new preliminary data, the Sagasti lab will pursue two future lines of research. First, since cortical contractility creates the biomechanical conditions enabling microridge morphogenesis, they will investigate how cross-linking proteins and cell junctions temporally and spatially tune cortical contractility to promote microridge formation and patterning. Since cortical contractility controls many cellular processes, these experiments will reveal regulatory mechanisms with wide relevance in cell biology. Second, since Plakin cytolinkers are central regulators of microridge initiation and elongation, they will investigate how the structure of Plakins relate to their functional roles in microridge morphogenesis, and use Plakin proteins as handles for identifying new regulatory components of the cytoskeletal scaffold that creates microridge protrusions.

项目总结 基于肌动蛋白的突起赋予细胞各种各样的形式。粘膜上皮表面的细胞 角膜和口腔等组织通常突出细长的皱纹状突起，称为微脊， 它们以迷宫状图案排列在顶面上。微脊帮助这些细胞保留粘液，因此 保护脆弱的上皮组织免受感染、磨损和干燥。直到最近，几乎什么都没有 是关于微脊形态发生的。由于微脊的形态不同于更好的- 研究突起，研究它们可以揭示突起形态发生的基本新原理。 近年来，萨加斯蒂实验室建立了斑马鱼幼体皮肤细胞作为研究微脊的模型。 形态发生。这个模型使得强大的分子操作和形态发生的实时成像成为可能。 Sagasti实验室的初步研究揭示了几个新的发现，包括：1)微脊的解剖 形态发生分成四个分子可分离的步骤，2)发现肌球蛋白在根尖收缩 皮质调节表面张力以允许微脊的形成，3)Plakin细胞连接物的鉴定为 掌握微脊长度的调节器，4)发现角蛋白细丝是 它们的稳定性和延伸性所需的微脊(第一个例子直接是中间纤维 有助于突起的形态发生)，以及5)发现皮质肌球蛋白微丝协调 一种不同寻常的微脊裂变/聚变重排过程，有助于形成规则的、周期性的 细胞表面的微脊排列。总而言之，这些发现对如何 皮质肌球蛋白、细胞连接蛋白和中间细丝有助于突起的形态发生。 在这些成就和新的初步数据的基础上，萨加斯蒂实验室将继续研究两条未来的路线 研究。首先，由于皮质的收缩能力创造了使微脊形成的生物力学条件 形态发生，他们将研究交联蛋白和细胞连接是如何在时间和空间上调节的 促进微脊形成和图案化的皮质收缩能力。由于皮质收缩能力控制着许多 这些实验将揭示在细胞生物学中具有广泛相关性的调控机制。 其次，由于Plakin细胞连接分子是微脊起始和延伸的中央调节因子，它们将 研究Plakins的结构如何与其在微脊形态发生中的功能作用有关，并使用 Plakin蛋白作为手柄，用于识别细胞骨架支架的新调节成分，该支架可产生 微脊突起。