Cell junction and nuclear forces as mediators of epithelial cell homeostasis

上皮细胞排列在体腔内外，以单层存在于组织中， 多层细胞和三维管/导管结构。正常形成和体内平衡 上皮细胞对于组织和器官功能至关重要;上皮细胞的失调与上皮细胞的增殖有关。 屏障丧失（包括脓毒症）、伤口愈合缺陷以及癌症的发展和进展。强 细胞-细胞连接对上皮的完整性至关重要，包括细胞凝聚力、屏障功能和 抵抗机械应力的能力。连接缺失与上皮功能障碍有关，包括 炎症诱导的渗透性和上皮向间质转化（EMT）的增加。虽然 形成细胞-细胞粘附已被证明是细胞增殖、迁移和增殖的关键调节因子。 组织组织，很少有人知道细胞间连接力如何促成这些过程。此外，本发明还提供了一种方法， 细胞核，其通过LINC（核骨架的连接体， 细胞骨架）复合物也经历由肌动球蛋白收缩性和 在细胞-细胞接触和细胞-基质粘附上施加的外力。核力量已经被证明 调节细胞周期、核孔复合体和染色质。我的小组最近的工作也表明， LINC复合体是上皮细胞稳态的关键结构。这项建议审查了武力的作用， 细胞-细胞连接和细胞核中的蛋白质作为上皮稳态的介质。主要 这项R35 MIRA更新的研究目标是：1）研究机械力如何调节上皮细胞 稳态和形态发生，2）鉴定LINC复合物在上皮稳态中的作用， 间充质干细胞分化，以及3）研究细胞核核板层和核孔之间的力 复合物调节上皮生理学。提出的实验包括导管/腺体的体外模型， 上皮使用基于FRET的张力生物传感器直接测量穿过紧密连接、粘附 连接和桥粒，以及LINC复合物、核孔和核纤层。新的和 现有的技术方法将被用来调整这些结构，目的是识别 力的上游调节器和受力调节的下游过程。此外，在体内 小鼠模型将用于评估LINC复合物和桥粒在3D上皮组织中的作用 体内平衡这种对细胞粘附和核力的全面研究将大大推进 了解上皮细胞的稳态是如何调节的，这与伤口修复的过程有关， 炎症和上皮组织发育和组织，以及上皮疾病，包括 癌症纤维化和慢性炎症此外，从这项研究的结果有关的作用，部队 核板层和核孔复合体上的蛋白质的表达将与几乎所有的细胞类型和组织相关。

Epithelial cells, which line both the inside cavities and outside of the body, exist in tissues as monolayers, multilayers of cells, and three dimensional tube/duct structures. Proper formation and homeostasis of the epithelium is critical for tissue and organ function; dysregulation of the epithelium is associated with epithelial barrier loss (including sepsis), defective wound healing, and development and progression of cancer. Strong cell-cell junctions are critical to the integrity of the epithelium, including cell cohesion, barrier function, and ability to resist mechanical stress. Loss of junctions is associated with epithelial dysfunction including inflammatory-induced increases in permeability and epithelial to mesenchymal transition (EMT). Although formation cell-cell adhesions have been shown to be critical regulators of cell proliferation, migration, and tissue organization, very little is known how cell-cell junction forces contribute to these processes. In addition, the nucleus, which is physically connected to the cytoskeleton by the LINC (Linker of Nucleoskeleton and Cytoskeleton) complex also experiences mechanical force resulting from both actomyosin contractility and externally applied forces across cell-cell contacts and cell-matrix adhesions. Nuclear forces have been shown to regulate the cell cycle, nuclear pore complex, and chromatin. Recent work by my group has also shown that the LINC complex is a critical structure for epithelial homeostasis. This proposal examines the role of force across proteins in both cell-cell junctions and the nucleus as mediators of epithelial homeostasis. The major research goals of this R35 MIRA renewal are to 1) examine how mechanical forces regulate epithelial homeostasis and morphogenesis, 2) identify the role of the LINC complex in epithelial homeostasis and mesenchymal stem cell differentiation, and 3) investigate how forces across nuclear lamins and nuclear pore complexes regulate epithelial physiology. Proposed experiments include in vitro models of ductal/glandular epithelium using FRET-based tension biosensors to directly measure forces across tight junctions, adherens junctions, and desmosomes, as well as the LINC complex, nuclear pores, and the nuclear lamina. New and existing technical approaches will be used to modulate these structures, with the objective of identifying both the upstream regulators of force and the downstream processes regulated by force. Additionally, in vivo mouse models will be used to assess the role of the LINC complex and desmosomes in 3D epithelial tissue homeostasis. This comprehensive study of cell adhesion and nuclear forces will greatly advance the understanding of how epithelial homeostasis is regulated, which is relevant to the processes of wound repair, inflammation, and epithelial tissue development and organization, as well as epithelial diseases, including cancer, fibrosis, and chronic inflammation. Furthermore, results from this study concerning the role of forces on the nuclear lamina and nuclear pore complexes will be relevant to nearly all cell types and tissues.