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: 10365340
• 负责人: Jimmy Kuang-Hsien Hu
• 金额: $ 36.11万
• 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/10365340
• 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; Epithelial; 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; Natural regeneration; 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; base; 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; 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.

项目摘要 有效利用体细胞修复受伤的组织或生物工具器官是重要的目标 在再生医学中。但是，干细胞在疗法中的临床经验化应用在疗法中仍然有限 今天的医学。翻译障碍在很大程度上是由于我们缺乏精确控制干细胞的能力 扩散和分化，这对于安全有效的临床使用至关重要。为了克服这个挑战， 我们必须首先加深对器官正常干细胞调节的了解。除了生化信号， 从理论上讲，由细胞拉和推动施加的组织机械力可以用作信号机制 调节成人干细胞中的基因表达和各种细胞过程。但是，调制和 这些力信号在3D组织中的影响大大研究了，在周围留下了开放的问题 干细胞如何感知和解释力。我们和其他人已经证明了鼠标门牙是一个强大的 研究成年上皮干细胞的模型系统，我们先前已经表明转录副因素 是相关的蛋白（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 包装可以影响切牙干细胞小众中YAP和抑制性染色质标记的表达。这 因此，鼠标门牙提供了一个有价值的体内平台，以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 致密的细胞堆积调节组织力对核变形的影响，进而调节YAP 核进入和H3K27ME3介导的牙皮上皮干细胞中的转录抑制。测试以下测试： AIM 1将表征野生型切牙中的力模式，大小和核刚度，特别是在 密集的牙齿上皮干细胞和更松散的传输扩增细胞。 AIM 2将研究细胞几何形状和填料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以测试力的作用。 AIM 3将解决层蛋白A在调节核刚度和异染色质形成中的功能作用 牙齿上皮干细胞及其对细胞填料的缩放反应。 总之，这些研究将对组织力如何控制牙科干细胞有一种机械理解 牙科研究人员和干细胞和再生的产量结果都将引起人们的普遍关注 医学界。