Dynamic Hydrogels for Probing Hepatic Stellate Cell Behavior During Fibrosis

用于探测纤维化过程中肝星状细胞行为的动态水凝胶

• 批准号: 9104153
• 负责人: Steven Caliari
• 金额: $ 1.15万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2016-08-24
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9104153
• 关键词: Apoptosis; Biocompatible Materials; Biological Models; Cell Culture Techniques; Cell Differentiation process; Cells; Cessation of life; Chronic; Collagen; Collagen Type I; Cues; Deposition; Development; Disease; Disease model; Disease regression; Down-Regulation; Extracellular Matrix; Extracellular Matrix Proteins; Faculty; Fibroblasts; Fibrosis; Gel; Gene Expression; Genes; Glial Fibrillary Acidic Protein; Goals; Health; Heat shock proteins; Heavy Drinking; Hepatic; Hepatic Stellate Cell; Hepatitis; Hepatocyte; Hyaluronic Acid; Hydrogels; Hydrolysis; Injury; Kidney; Laboratories; Lipids; Liver; Liver Fibrosis; Liver diseases; Lung; Maintenance; Malignant Neoplasms; Matrix Metalloproteinases; Mechanics; Mediating; Methods; Modeling; Myofibroblast; Natural regeneration; Nature; Organ; Pancreas; Pathology; Pennsylvania; Pericytes; Phenotype; Process; Production; Property; Research; Research Training; Retinoids; Rodent Model; Role; Scientist; Smooth Muscle Actin Staining Method; Source; System; Therapeutic Intervention; Time; Tissues; Transforming Growth Factors; Triad Acrylic Resin; Universities; Visible Radiation; Vitamin A; Werdnig-Hoffmann Disease; Work; Wound Healing; base; biophysical properties; career; cell behavior; collaborative environment; combat; crosslink; cytokine; experience; fibrogenesis; improved; in vitro Model; in vivo; meetings; member; polyacrylamide; receptor; response; response to injury; targeted treatment; therapeutic target; therapy development; tissue culture; tool; tumor growth

DESCRIPTION (provided by applicant): The differentiation of pericytes and fibroblasts to fibrogenic myofibroblasts is a common response to injury in many tissues, including the pancreas, lung, kidney, and liver. However, the persistence of myofibroblasts leads to excessive extracellular matrix (ECM) deposition and contraction, resulting in fibrosis and loss of organ function. Liver fibrosis is a serious health problem occurring in response to chronic insults, including hepatitis and excessive alcohol consumption. Hepatic stellate cells (HSCs) comprise ~ 15% of total resident liver cells and are also the primary source of hepatic myofibroblasts during fibrosis. With over 1.7 million deaths attributed to liver disease annually, extensive research is underway to better understand fibrosis progression and HSC myofibroblastic differentiation. Notably, there is growing appreciation for the role of local mechanical properties in regulating HSC activation, which is the focus of the proposed project. I propose that improved understanding of the microenvironmental cues that regulate HSC differentiation is critical to the development of therapies to combat liver fibrosis, and that biomaterials with controlled biophysical properties can be used as model systems to better probe the role of local mechanics on HSC behavior. Although initial studies in the Burdick and Wells laboratories have illustrated the influence of static material mechanics on HSC differentiation, there is still a gret need for dynamic material systems to mimic the evolving properties of native tissues. Therefore, the general objective of this proposal is to develop mechanically dynamic material systems based on hyaluronic acid (HA) to model HSC phenotypic changes during the progression and regression of fibrosis. The Burdick lab has a wealth of experience in developing tunable HA biomaterials and the Wells lab has expertise in liver mechanobiology and rodent models of liver fibrosis; thus, I am ideally suited to undertake the work proposed here. In Aim 1 I will develop hydrogels that stiffen over time to model the progression of fibrosis using secondary radical crosslinking that introduces additional crosslinks into an already formed hydrogel. I hypothesize that the rate of stiffening will determine the ultimate degree of myofibroblast differentiation and fibrogenesis, with more gradual stiffening leading to intermediate phenotypes. In Aim 2 I will develop hydrogels that soften over time via hydrolysis of crosslinks to model regression of fibrosis. I hypothesize that softening materials will yield HSCs with an intermediate phenotype similar to that observed in vivo during fibrosis regression and that the rate of softening will determine the ultimate phenotype. Together, the dynamic substrates developed here will be useful as streamlined models of other disease states in the wound healing-fibrosis-cancer triad and as ex vivo tools to identify potential targets for therapeutic intervention. Together, the proposed research and training plans in addition to the strong collaborative environment at the University of Pennsylvania will guide my development as a scientist and help me meet my career goal of becoming an independent faculty member.

描述（由申请人提供）：周细胞和成纤维细胞与纤维纤维成肌纤维细胞的分化是许多组织中损伤的常见反应，包括胰腺，肺，肾脏，肾脏和肝脏。然而，肌纤维细胞的持久性导致细胞外基质（ECM）沉积和收缩过多，导致器官功能的纤维化和丧失。肝纤维化是响应慢性损伤（包括肝炎和过度饮酒）而引起的严重健康问题。肝星细胞（HSC）占常驻肝细胞的约15％，也是纤维化过程中肝成肌纤维细胞的主要来源。每年归因于肝病的170万人死亡，正在进行广泛的研究，以更好地了解纤维化进展和HSC肌纤维细胞分化。值得注意的是，人们对局部机械性能在调节HSC激活中的作用越来越多，这是拟议项目的重点。我建议，对调节HSC分化的微环境线索的了解对打击肝纤维化的疗法的发展至关重要，并且具有控制生物物理特性的生物材料可以用作模型系统，以更好地探测局部力学对HSC行为的作用。尽管对Burdick和Wells实验室的初步研究说明了静态材料力学对HSC分化的影响，但仍需要动态材料系统模仿天然组织的发展特性。因此，该提案的一般目标是开发基于透明质酸（HA）的机械动态材料系统，以模拟HSC表型在纤维化的进展和回归期间的模型。 Burdick Lab在开发可调的HA生物材料方面具有丰富的经验，Wells Lab具有肝纤维化的肝脏机械生物学和啮齿动物模型的专业知识。因此，我非常适合在此处进行提出的工作。在AIM 1中，我将开发随着时间的推移加强的水凝胶，以使用次级自由基交联对纤维化的进展进行建模，从而将附加的交联引入已经形成的水凝胶中。我假设加强速率将决定肌纤维细胞分化的最终程度和 纤维发生，逐渐加强导致中间表型。在AIM 2中，我将开发通过交联的水解来模拟纤维化回归的水解凝胶。我假设软化材料将产生与纤维化回归期间体内观察到的中间表型的HSC，并且软化速率将决定最终表型。总之，此处开发的动态底物将有用，可作为伤口愈合纤维化结构症中其他疾病状态的简化模型，以及作为识别治疗干预措施的潜在靶标的外体工具。除了宾夕法尼亚大学的强大协作环境外，拟议的研究和培训计划共同指导我作为科学家的发展，并帮助我实现成为独立教师的职业目标。