Mechanical regulation of transcription in dental epithelial stem cells through cell packing and tissue forces

通过细胞堆积和组织力对牙上皮干细胞转录的机械调节

• 批准号: 10533335
• 负责人: Jimmy Kuang-Hsien Hu
• 金额: $ 36.09万
• 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: 2022-04-01 至 2027-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10533335
• 关键词: 3-Dimensional; Ablation; Address; Adult; Affect; Alleles; Architecture; Atomic Force Microscopy; Biochemical; Biological Models; Biomechanics; Biomedical Engineering; Cell Density; Cell Differentiation process; Cell Maintenance; Cell Nucleus; Cell Shape; Cell physiology; Cells; Chromatin; Chromatin Structure; Chronic; Clinical; Community Medicine; Data; Dental; Devices; Epigenetic Process; Epithelium; Exhibits; Future; Gene Expression; Genetic Transcription; Geometry; Goals; Heterochromatin; Homeobox Genes; Human; Image; In Situ; Incisor; Knowledge; Lamin Type A; Lasers; Life Style; Magnetism; Maps; Measures; Mechanics; Mediating; Medicine; Membrane Proteins; Microscopy; Microtubules; Molecular; Mus; Nuclear; Nuclear Envelope; Nuclear Import; Nuclear Pore; Nuclear Protein; Oils; Organ; Pattern; Phenotype; Polycomb; Process; Proteins; Public Health; Regenerative Medicine; Regulation; Repression; Research Personnel; Role; Shapes; Signal Transduction; Stress; System; Testing; Time; Tissues; Tooth Loss; Tooth regeneration; Tooth structure; Transcriptional Regulation; Weight-Bearing state; Work; adult stem cell; cofactor; differential expression; epithelial stem cell; experimental study; force sensor; gene repression; in vivo; injury and repair; interest; loss of function; mechanical force; mechanical signal; mouse genetics; mouse model; novel; physical property; progenitor; protein expression; regeneration potential; regenerative therapy; response; stem cell biology; stem cell fate; stem cell function; stem cell model; stem cell niche; stem cell proliferation; stem cell therapy; stem cells; theories

Project Summary Effective utilization of somatic stem cells to repair injured tissues or to bioengineer organs is an important goal in regenerative medicine. However, clinically-proven application of stem cells in therapies remains limited in medicine today. The translational hurdles are in large part due to our lack of ability to precisely control stem cell proliferation and differentiation, which is critical for safe and effective clinical use. To overcome this challenge, we must first deepen our knowledge of normal stem cell regulation in organs. In addition to biochemical signals, tissue mechanical forces exerted by cell pulling and pushing can in theory serve as a signaling mechanism to regulate gene expression and various cellular processes in adult stem cells. However, the modulation and influence of these force signals within a 3D tissue are dramatically understudied, leaving open questions around how stem cells sense and interpret forces. We and others have demonstrated the mouse incisor as a powerful model system to study adult epithelial stem cells and we have previously shown that the transcription co-factor Yes-associated protein (YAP) and chromatin repression are important for regulating incisor epithelial stem cells. Our initial studies indicate that both mechanical deformation of cells and the cell geometry associated with dense packing can influence the expression of YAP and repressive chromatin marks in the incisor stem cell niche. The mouse incisor thus provides a valuable in vivo platform to study how cellular organizations coordinate mechanical signals to control stem cell functions via YAP and chromatin. In this application, we propose to test the hypothesis that dense cell packing modulates the effect of tissue forces on nuclear deformations, which in turn regulate YAP nuclear entry and H3K27me3-mediated transcriptional repression in the dental epithelial stem cells. To test this: Aim 1 will characterize the force patterns, magnitude, and nuclear stiffness in wild type incisors, specifically in the densely packed dental epithelial stem cells and the more loosely packed transit amplifying cells. Aim 2 will study how changes in the cell geometry and packing affect tissue force patterns, nuclear deformations, YAP localization, and chromatin states. We will perform mechanical rescue experiments to test the role of forces. Aim 3 will address the functional role of lamin A in regulating nuclear stiffness and heterochromatin formation in the dental epithelial stem cells, as well as its scaling response to cell packing. Together, these studies will deliver a mechanistic understanding of how tissue forces control dental stem cells and yield findings that will be of general interest to both dental researchers and to the stem cell and regenerative medicine communities.

项目概要 有效利用成体干细胞修复受损组织或对器官进行生物工程是一个重要目标 在再生医学中。然而，经临床证明的干细胞在治疗中的应用仍然有限 今天医学。翻译障碍很大程度上是由于我们缺乏精确控制干细胞的能力 增殖和分化，这对于安全有效的临床使用至关重要。为了克服这一挑战， 我们首先必须加深对器官正常干细胞调节的认识。除了生化信号外， 细胞拉动和推动所施加的组织机械力理论上可以作为一种信号机制 调节成体干细胞的基因表达和各种细胞过程。然而，调制和 这些力信号在 3D 组织内的影响尚未得到充分研究，留下了一些悬而未决的问题 干细胞如何感知和解释力。我们和其他人已经证明小鼠门牙是一种强大的 研究成体上皮干细胞的模型系统，我们之前已经证明转录辅助因子 Yes相关蛋白（YAP）和染色质抑制对于调节切牙上皮干细胞很重要。 我们的初步研究表明细胞的机械变形和与致密相关的细胞几何形状 堆积可以影响切牙干细胞微环境中 YAP 和抑制性染色质标记的表达。这 因此，小鼠门牙提供了一个有价值的体内平台来研究细胞组织如何协调机械 通过 YAP 和染色质控制干细胞功能的信号。在此应用中，我们建议检验假设 密集的细胞堆积调节组织力对核变形的影响，进而调节 YAP 牙上皮干细胞中的核进入和 H3K27me3 介导的转录抑制。要测试这一点： 目标 1 将表征野生型门牙的力模式、大小和核刚度，特别是在 密集的牙上皮干细胞和更松散的传输放大细胞。 目标 2 将研究细胞几何形状和堆积的变化如何影响组织力模式、核变形、 YAP 定位和染色质状态。我们将进行机械救援实验来检验力量的作用。 目标 3 将解决核纤层蛋白 A 在调节核硬度和异染色质形成中的功能作用 牙上皮干细胞，以及其对细胞堆积的缩放反应。 总之，这些研究将提供对组织力如何控制牙科干细胞的机制理解 并得出牙科研究人员以及干细胞和再生细胞普遍感兴趣的发现 医学社区。