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: 10543459
• 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/10543459
• 关键词: Achievement; Actins; Actomyosin; Adsorption; Apical; Biomechanics; Cell physiology; Cell surface; Cells; Cellular biology; Cornea; Cytokeratin filaments; Cytoskeleton; Data; Dissection; Dryness; Endowment; Epithelial Cells; Epithelium; Future; Image; Infection; Intercellular Junctions; Intermediate Filaments; Length; Modeling; Molecular; Morphogenesis; Morphology; Mucous Membrane; Mucous body substance; Myosin ATPase; Oral cavity; Pattern; Periodicals; Process; Proteins; Research; Role; Skin; Structure; Study models; Surface; Surface Tension; Tissues; Work; Zebrafish; experimental study; genetic regulatory protein; novel; protein crosslink; 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.

项目概要 基于肌动蛋白的突起赋予细胞多种形式。粘膜上皮表面细胞 角膜和口腔等组织通常会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端表面上。微脊帮助这些细胞保留粘液，从而 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 已知微脊形态发生。由于微脊形态不同于那些更好的 研究了突起，研究它们可以揭示突起形态发生的基本新原理。 近年来，Sagasti 实验室建立了斑马鱼幼虫皮肤细胞作为研究微脊的模型 形态发生。该模型能够实现强大的分子操作和形态发生的实时成像。 Sagasti 实验室的初步研究揭示了几项新发现，包括：1）微脊的解剖 形态发生分为四个分子上可分离的步骤，2）发现顶端肌球蛋白收缩 皮质调节表面张力以允许微脊形成，3) Plakin 细胞接头的鉴定 微脊长度的主要调节因子，4）发现角蛋白丝是微脊的组成部分 其稳定性和伸长率所需的微脊（中间丝直接的第一个例子 有助于突出形态发生），以及 5）发现皮质肌球蛋白微丝协调 一种不寻常的微脊裂变/融合重排过程，有助于形成规则的、周期性的 细胞表面的微脊排列。总的来说，这些发现对于如何 皮质肌球蛋白、细胞接头和中间丝有助于突起形态发生。 基于这些成就和新的初步数据，Sagasti 实验室将在未来开发两条产品线： 研究。首先，由于皮质收缩性创造了微脊的生物力学条件 形态发生，他们将研究交联蛋白质和细胞连接如何在时间和空间上进行调整 皮质收缩促进微脊的形成和图案化。由于皮质收缩性控制着许多 细胞过程中，这些实验将揭示与细胞生物学具有广泛相关性的调节机制。 其次，由于 Plakin 细胞接头是微脊起始和伸长的中央调节因子，因此它们将 研究 Plakins 的结构如何与其在微脊形态发生中的功能作用相关，并使用 Plakin 蛋白作为识别细胞骨架支架新调控成分的手柄，从而产生 微脊突起。