Regulation of cell reprogramming by matrix stiffness

通过基质硬度调节细胞重编程

• 批准号: 10281141
• 负责人: Song Li
• 金额: $ 32.48万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-20 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10281141
• 关键词: Actins; Biocompatible Materials; Biological; Biology; Biophysical Process; Biophysics; Cardiac Myocytes; Cell Nucleus; Cell physiology; Cells; Cues; Cytoskeleton; Data; Development; Disease model; Distant; Drug Screening; Epigenetic Process; Extracellular Matrix; F-Actin; Fibroblasts; Focal Adhesions; G Actin; Gene Expression; Gene Targeting; Genes; Genomics; Histone Acetylation; Mediating; Microfilaments; Modification; Neurons; Nuclear; Nuclear Translocation; Phenotype; Play; Process; Regenerative Medicine; Regulation; Role; Site; Somatic Cell; Surface; Testing; Tissue Engineering; Transgenes; Work; base; cell type; cellular engineering; cofilin; depolymerization; design; drug discovery; epigenomics; experience; histone acetyltransferase; induced pluripotent stem cell; live cell imaging; migration; multidisciplinary; novel; novel strategies; nucleocytoplasmic transport; transcription factor; transcriptomics

Project Summary Cell reprogramming represents a major advancement in biology, and has wide applications in regenerative medicine, disease modeling and drug screening. During cell reprogramming, cells experience epigenetic changes that result in a cell phenotype switch. However, whether and how biophysical factors regulate cell reprogramming through epigenetic modifications are not well understood. We have found that biophysical factors, specifically extracellular matrix (ECM) stiffness, has profound effects on epigenetic state and the conversion of fibroblasts into induced neuronal (iN) cells, with the highest efficiency at an intermediate ECM stiffness, which is regulated by focal adhesions and the cytoskeleton. In addition, we have discovered that actin assembly and transport into nucleus plays an important role in epigenetic modulation. Based on our preliminary data, we hypothesize that (1) biophysical cues such as ECM stiffness regulates FAs, actin assembly/disassembly, nuclear transport of actin, and thus, HAT activity to modulate the epigenetic state and cell reprogramming process and (2) an intermediate level of stiffness is optimal for epigenetic remodeling and cell reprogramming. To test our hypothesis, we propose three Specific Aims: (1) Investigate how matrix stiffness regulates iN reprogramming through FAs and actin cytoskeleton, (2) Elucidate how matrix stiffness modulates HAT and the epigenetic state to turn on neuronal genes during iN reprogramming, and (3) Determine the role of actin nuclear transport in matrix stiffness- modulation of HAT and epigenetic state during iN reprogramming. We have assembled a multidisciplinary team with expertise on mechanobiology, cell engineering, high throughput genomic and epigenomic analysis, and live cell imaging to work together and investigate the underlying biophysical and biological mechanisms. Our proposed studies will be one of the first to elucidate how ECM stiffness regulates transcriptomic and epigenetic changes for cell reprogramming, and how ECM stiffness modulates focal adhesions and the cytoskeleton for cell reprogramming. Findings from this project will unravel new mechanisms of cell fate determination, which will have wide applications in cell and tissue engineering, disease modeling and drug discovery, and provide a rational basis for the optimization and development of novel biomaterials for somatic cell reprogramming.

项目概要 细胞重编程代表了生物学的重大进步，在以下领域具有广泛的应用 再生医学、疾病建模和药物筛选。在细胞重编程过程中，细胞经历 表观遗传变化导致细胞表型转换。然而，生物物理因素是否以及如何 通过表观遗传修饰调节细胞重编程尚不清楚。我们发现 生物物理因素，特别是细胞外基质 (ECM) 硬度，对表观遗传具有深远影响 状态以及将成纤维细胞转化为诱导神经元 (iN) 细胞，效率最高 中等 ECM 硬度，由粘着斑和细胞骨架调节。此外，我们 发现肌动蛋白组装和转运到细胞核中在表观遗传中起着重要作用 调制。根据我们的初步数据，我们假设 (1) 生物物理线索，例如 ECM 硬度调节 FA、肌动蛋白组装/分解、肌动蛋白核运输，从而调节 HAT 活性 调节表观遗传状态和细胞重编程过程，(2) 中等硬度 最适合表观遗传重塑和细胞重编程。为了检验我们的假设，我们提出了三个 具体目标：(1) 研究基质硬度如何通过 FA 和肌动蛋白调节 iN 重编程 细胞骨架，(2) 阐明基质刚度如何调节 HAT 和表观遗传状态以开启神经元 iN 重编程期间的基因，以及（3）确定肌动蛋白核运输在基质刚度中的作用- iN 重编程过程中 HAT 和表观遗传状态的调节。我们汇集了多学科 团队拥有机械生物学、细胞工程、高通量基因组和表观基因组方面的专业知识 分析和活细胞成像一起工作并研究潜在的生物物理和生物学 机制。我们提出的研究将是第一个阐明 ECM 刚度如何调节的研究之一 细胞重编程的转录组和表观遗传变化，以及 ECM 硬度如何调节局部 细胞重编程的粘附和细胞骨架。该项目的研究结果将揭示新的 细胞命运决定机制，将在细胞和组织工程中具有广泛的应用， 疾病建模和药物发现，为疾病的优化和开发提供合理依据 用于体细胞重编程的新型生物材料。