Elucidating Effects of Fibrosis on Aged Stem Cells with Dynamic Biomaterials

用动态生物材料阐明纤维化对衰老干细胞的影响

• 批准号: 10740968
• 负责人: Christopher Matthew Madl
• 金额: $ 24.9万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-15 至 2025-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10740968
• 关键词: 3-Dimensional; Acute; Adhesives; Aging; Attention; Biochemical; Biochemistry; Biocompatible Materials; Bioinformatics; Biological Models; Biology of Aging; Biophysics; Cell Culture Techniques; Cells; Cessation of life; Characteristics; Chemistry; Chronic; Complex; Coupled; Cues; Data; Defect; Deposition; Development; Disease; Engineering; Engraftment; Environment; Exhibits; Extracellular Matrix; Extracellular Matrix Proteins; Faculty; Failure; Fibrosis; Fluorescence Resonance Energy Transfer; Functional disorder; Gel; Generations; Goals; Health; Heritability; Histology; Human; Hydrogels; Impairment; In Vitro; Individual; Inflammation; Life; Light; Machine Learning; Measurement; Measures; Mechanics; Mentors; Modeling; Molecular; Molecular Target; Mus; Muscle; Muscle function; Muscle satellite cell; Muscular Atrophy; Natural regeneration; Organ failure; Pathogenesis; Pathologic; Pharmaceutical Preparations; Phase; Physiological; Property; Protein Engineering; Reaction; Regenerative capacity; Rejuvenation; Research; Research Proposals; Role; Skeletal Muscle; Stromal Cells; Structure; System; Time; Tissue Model; Tissues; Traction; Training; Transgenic Mice; Transplantation; Writing; adult stem cell; aged; aging population; bioluminescence imaging; crosslink; force sensor; genetic approach; human model; improved; in vitro Model; in vivo; induced pluripotent stem cell; insight; intercellular communication; mechanical force; mechanical properties; mechanotransduction; medical schools; mouse model; muscle aging; new therapeutic target; novel; novel therapeutics; p38 Mitogen Activated Protein Kinase; programs; regeneration function; regeneration potential; repaired; response; rho GTP-Binding Proteins; single-cell RNA sequencing; small molecule inhibitor; stem cell function; stem cell niche; stem cell population; stem cells; three dimensional cell culture; three-dimensional modeling; tissue regeneration; tissue repair; transcriptomics; viscoelasticity; wound healing

PROJECT SUMMARY Despite the ubiquitous role of fibrosis in tissue dysfunction arising from aging and disease, no representative in vitro model of the fibrotic microenvironment exists. Fibrosis is characterized by excess extracellular matrix (ECM) deposition that stiffens the cellular microenvironment. Therefore, to model fibrosis in vitro, cell culture substrates that permit quantitative, dynamic tuning of matrix mechanics and composition are necessary. However, existing dynamic hydrogel culture platforms generally rely on chemistries that may be toxic to cells or that simultaneously change multiple parameters, making it difficult to assign causal relationships between altered matrix properties and cell fate changes. Fibrotic stiffening occurs in a wide range of tissues, including skeletal muscle. Along with increased fibrosis, the regenerative function of skeletal muscle decreases with aging. Muscle stem cells (MuSCs) are responsible for maintaining and repairing muscle throughout life and are known to be acutely mechanosensitive, losing their stem cell potential when cultured on stiff substrates. Thus, the stiffened, fibrotic microenvironment may contribute to the diminished regenerative capacity of aged MuSCs. The goal of this project is to develop an in vitro model of tissue fibrosis based on dynamic hydrogel biomaterials and to employ this model to identify molecular mechanisms of MuSC mechanosensing that are implicated in MuSC dysfunction in aging. The mentored phase of this proposal will provide advanced technical training in aging biology, transgenic mouse models, cellular traction force measurement, and machine learning approaches for bioinformatics. This training will enable an independent research program leveraging dynamic biomaterials to deconvolve the complex interactions of mechanical forces, matrix biochemistry, and cell-cell signaling that dictate the progression of aging and disease. Additional structured training in scientific writing, grantsmanship, and research management will facilitate the transition to independence, supported by a committee of faculty from the Stanford Schools of Medicine and Engineering. Aim 1 will optimize a synthetic hydrogel system that uses near-infrared light and bioorthogonal reactions to dynamically stiffen the gels, mimicking fibrosis. These hydrogels will be used to elucidate mechanisms of mechanosensing in MuSCs, using FRET-based force sensors and transgenic mouse models. Aim 2 will model muscle aging in vitro, using dynamically stiffening gels modified with ECM components characteristic of aging. Single cell RNA sequencing and machine learning bioinformatics approaches will identify unique mechanically regulated drivers of cell fate that reduce MuSC regenerative potential in aging. Aim 3 will develop novel materials for 3D cell culture with dynamic tuning of viscoelastic properties to establish the first human model of muscle “aging in a dish.” This project stands to identify new therapeutic targets to improve muscle function with aging and to develop engineered platforms to study numerous heritable diseases and aging in diverse tissues.

项目摘要 尽管纤维化在衰老和疾病引起的组织功能障碍中无处不在 存在代表纤维化微环境的体外模型。纤维化的特征是超过 细胞外基质（ECM）沉积，使细胞微环境僵硬。因此，模拟纤维化 体外，允许定量的，动态调整基质力学和组成的细胞培养底物是 必要的。但是，现有的动态水凝胶培养平台通常依赖于可能是 对细胞有毒或只是改变多个参数，因此很难分配因果关系 基质特性改变与细胞脂肪变化之间的关系。纤维化僵硬发生在广泛的范围内 组织，包括骨骼肌。随着纤维化的增加，骨骼肌的再生功能 随着衰老而减小。肌肉干细胞（MUSC）负责维持和修复肌肉 一生中，已知敏锐的机械敏感 僵硬的底物。这是僵硬的纤维化微环境可能导致再生的降低 老年MUSC的能力。该项目的目的是基于 动态水凝胶生物材料并采用该模型来鉴定MUSC的分子机制 MUSC功能障碍在衰老中暗示的机械感应。该提议的修订阶段将 提供老化生物学，转基因小鼠模型，细胞牵引力的高级技术训练 测量和生物信息学的机器学习方法。这项培训将使独立 利用动态生物材料的研究计划解除机械的复杂相互作用 决定衰老和疾病进展的力，基质生物化学和细胞信号传导。额外的 科学写作，授予技巧和研究管理方面的结构化培训将有助于过渡到 独立，得到斯坦福大学医学与工程学校的教师委员会的支持。 AIM 1将优化一种合成水凝胶系统，该系统使用近红外光和生物正交反应 动态加强凝胶，模仿纤维化。这些水凝胶将用于阐明 使用基于FRET的力传感器和转基因小鼠模型的MUSC中的机械感应。 AIM 2将建模 在体外肌肉衰老，使用用ECM成分进行动态加强凝胶的衰老特征。 单细胞RNA测序和机器学习生物信息学方法将机械识别独特 调节细胞命运的驱动因素，以减少MUSC衰老中的再生潜力。 AIM 3将发展小说 3D细胞培养的材料，具有粘弹性特性的动态调整，以建立第一个人类模型 肌肉“在盘子里老化”。该项目将确定新的治疗靶标，以改善肌肉功能 衰老并开发工程平台，以研究多样性组织中多种可遗传的疾病和衰老。