Tunable Synthetic ECMs for Investigating Stellate Cell Activation and Migration

用于研究星状细胞激活和迁移的可调谐合成 ECM

• 批准号: 10396228
• 负责人: Matthew David Davidson
• 金额: $ 3.52万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10396228
• 关键词: 3-Dimensional; Address; Adhesions; Affect; Area; Behavior; Biocompatible Materials; Cause of Death; Cell Culture Techniques; Cell Differentiation process; Cell Separation; Cell physiology; Cells; Cellular biology; Characteristics; Chronic; Cicatrix; Cirrhosis; Communication; Deposition; Development; Distant; Elasticity; Environment; Etiology; Evolution; Extracellular Matrix; Fiber; Fibroblasts; Fibrosis; Gel; Glass; Health; Hepatic Stellate Cell; Hyaluronic Acid; Hydrogels; Impaired healing; In Vitro; Individual; Knowledge; Light; Lipids; Liver; Liver Fibrosis; Liver diseases; Mechanical Stimulation; Mechanics; Mediating; Mediator of activation protein; Monitor; Myofibroblast; Natural regeneration; Organ failure; Patients; Pattern; Phenotype; Physical environment; Play; Population; Positioning Attribute; Process; Property; Retinoids; Role; Site; Smooth Muscle Actin Staining Method; Stimulus; Surface; System; TGFB1 gene; Tissues; Training; Translating; Viral hepatitis; Work; base; career; cell motility; chemical reaction; chronic liver injury; crosslink; density; directional cell; experience; fiber cell; healing; imaging modality; in vivo; interest; liver injury; mechanical properties; migration; nanofiber; new therapeutic target; non-alcoholic fatty liver disease; precursor cell; recruit; response; stellate cell; transmission process

ABSTRACT Liver fibrosis is an abnormal healing response to chronic liver injury and predisposes patients to cirrhosis, which is a major cause of death worldwide. Although fibrosis has many etiologies, it only occurs after portal fibroblasts and or hepatic stellate cells (HSCs) differentiate into myofibroblasts, a process termed activation. HSCs are the major contributors to the myofibroblast population in fibrosis and chronic liver damage stimulates continuous HSC activation, tissue contraction and excessive extracellular matrix (ECM) deposition, resulting in fibrosis and organ failure. Thus, it is important to understand the factors that contribute to fibrosis progression and HSC myofibroblast differentiation, such as the physical microenvironment. To date, in vitro studies have shown that substrate elasticity is a critical mediator of myofibroblast differentiation, using hydrogels of varied mechanics. This is thought to mimic the changes in liver stiffness that occurs during fibrosis; however, cells in the liver reside in a fibrous 3D ECM, which may not be recapitulated with seeding atop smooth hydrogels. Importantly, fibrous materials may be manipulated by cells and have non-linear mechanics that enable long- range force transmission through fiber alignment. Thus, the objective of this proposal is to develop tunable synthetic fibrous materials based on hyaluronic acid that mimic the ECM of the liver to investigate how static and dynamic fiber mechanics influence HSC activation and migration. These proposed fibrous systems are unique from both natural ECMs that are difficult to tailor and from typically rigid synthetic fibers. The first Aim of this proposal will be the development of nanofiber cell culture substrates with a range of mechanical properties. It is hypothesized that stiffer nanofibers will limit cell fiber remodeling and activation, while softer nanofibers will permit fiber remodeling/recruitment and activation under the fibrogenic stimulus TGFb1. Aim 2 of this proposal will be the development of nanofibrous materials that can be locally stiffened around HSCs using light triggered chemical reactions to mimic the dynamic crosslinking of ECM that occurs during fibrosis. It is hypothesized that HSCs will migrate directionally based on local fiber mechanical properties. Together, the materials developed here will provide new platforms to study fibrosis and healing, inspire the development of new fibrosis therapies, and provide training within new materials and HSC biology to the applicant.

抽象的 肝纤维化是对慢性肝损伤的异常愈合反应，使患者容易患上肝硬化， 这是全世界死亡的一个主要原因。尽管纤维化有多种病因，但仅发生在门静脉后 成纤维细胞和/或肝星状细胞 (HSC) 分化为肌成纤维细胞，这一过程称为激活。 HSC 是肌成纤维细胞群纤维化的主要贡献者，慢性肝损伤刺激 持续的 HSC 激活、组织收缩和过度的细胞外基质 (ECM) 沉积，导致 纤维化和器官衰竭。因此，了解导致纤维化进展的因素很重要 和HSC肌成纤维细胞分化，如物理微环境。迄今为止，体外研究已 研究表明，基质弹性是肌成纤维细胞分化的关键介质，使用不同的水凝胶 机械师。这被认为模仿了纤维化过程中肝脏硬度的变化。然而，细胞中 肝脏位于纤维状 3D ECM 中，这可能无法通过在光滑水凝胶上播种来重现。 重要的是，纤维材料可以由细胞操纵，并具有非线性力学，可以实现长期 通过光纤对准​​进行范围力传输。因此，该提案的目标是开发可调谐的 基于透明质酸的合成纤维材料模拟肝脏的 ECM，以研究静态如何 动态纤维力学影响 HSC 的激活和迁移。这些提出的纤维系统是 不同于难以定制的天然 ECM 和典型的刚性合成纤维。第一个目标 该提案将开发具有一系列机械性能的纳米纤维细胞培养基质。 据推测，较硬的纳米纤维将限制细胞纤维的重塑和激活，而较软的纳米纤维将限制细胞纤维的重塑和激活。 允许纤维在纤维形成刺激 TGFb1 下重塑/募集和激活。本提案的目标 2 将开发纳米纤维材料，该材料可以使用光触发在 HSC 周围局部硬化 化学反应模拟纤维化过程中发生的 ECM 动态交联。假设 HSC 将根据局部纤维机械性能定向迁移。共同开发的材料 这里将提供研究纤维化和愈合的新平台，激发新纤维化疗法的开发， 并为申请人提供新材料和 HSC 生物学方面的培训。