Extracellular Scaffold Elasticity and Binding Sites in Acinar Differentiation

腺泡分化中的细胞外支架弹性和结合位点

基本信息

批准号：
8385517
负责人：
MELINDA LARSEN
金额：
$ 18.24万
依托单位：
STATE UNIVERSITY OF NEW YORK AT ALBANY
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-12-01 至 2014-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8385517
关键词：
Abbreviations Acinar Cell Address Affect Alanine Artificial Organs Atomic Force Microscopy Basement membrane Binding Binding Sites Biological Assay Biopolymers Cell Density Cell Differentiation process Cell Line Cell-Matrix Junction Cells Characteristics Chemicals Chemistry Collagen Type IV Complex Data Detection Differentiation Antigens Elasticity Embryo Engineering Environment Epithelial Epithelial Cells Ethylene Glycols Ethylene Oxide Extracellular Matrix Future Gel Generations Goals Green Fluorescent Proteins Growth Human Hydrogels Implant In Vitro Isoleucine Knowledge Life Lysine Maintenance Mammary gland Mechanics Mesenchymal Stem Cells Methacrylates Morphogenesis Mus Natural regeneration Organ Patients Play Polyethylene Glycols Polymerase Chain Reaction Property Quality of life Rattus Regulation Resistance Role Saliva Salivary Salivary Glands Series Signal Transduction Site Sjogren&apos s Syndrome Stem cells Symptoms Testing Tissue Differentiation Tissue Engineering Tissues Valine Work Xerostomia base blastomere structure crosslink density design ethylene glycol extracellular immunocytochemistry in vivo lithography man matrigel novel salivary acinar cell sarcoma scaffold stem stem cell differentiation success

项目摘要

DESCRIPTION (provided by applicant): One of the most significant challenges currently facing the field of tissue engineering is the ability to stimulate and/or maintain epithelial cell differentiation in engineered tissues. Since epithelial cell secretory function is crucial to organ function, understanding the mechanisms regulating and maintaining cellular differentiation is critical to regenerating or engineering functional tissues. A man-made functional saliva-secreting salivary gland construct would greatly increase the quality of life for patients suffering from salivary hypofunction, but such engineered tissues have yet to be generated, and in vitro salivary acinar differentiation remains difficult to sustain. The cellular microenvironment plays a significant role in cell differentiation, and yet little is known regarding the specific characteristics of the microenvironment that regulate cell differentiation. Engineered scaffolds often fail to mimic the microenvironment and, in fact, the most effective scaffolds for tissue engineering are decellularized scaffolds derived from live tissue. Since the goal of tissue engineering is to be able to synthesize scaffolds that out-perform decellularized natural scaffolds, it is necessary to understand how the essential characteristics of the natural extracellular matrix (chemical, mechanical/elastic, and topological properties) affect cell differentiation. Recent studies have identified the importance of elasticity of the microenvironment in determining the extent of differentiation of mesenchymal stem cells; however, the significance of elasticity in regulation of epithelial tissue differentiation has not been investigated. Chemical signals, including growth regulatory factors and binding sites, have been much more extensively studied, but the relationship between chemical signals and elasticity remains largely unknown. The overall aim of this project is to define the function of substrate elasticity and cell binding site density in regulating submandibular salivary gland (SMG) acinar cell differentiation. We will use cell lines and embryonic primary cells to address this aim using novel tunable PEG hydrogel scaffolds. We hypothesize that acinar cell differentiation requires a compliant extracellular matrix having optimal cell binding sites which is disrupted at atypical substrate rigidities. To address this hypothesis, we propose to use tunable polyethylene-glycol (PEG)-based hydrogels in three specific aims: Aim 1. Develop PEG-based hydrogels of varied elasticity containing different levels of binding sites. Aim 2. Identify the contributions of elasticity and cell organization in modulating acinar cell differentiation using the hydrogel scaffolds. Aim 3. Use bilayer lithography to create microwell scaffolds for use with primary cells. Abbreviations: AFM, atomic force microscopy; Col IV, collagen type IV; ECM, extracellular matrix; GFP, green fluorescent protein; IKVAV, Isoleucine-Lysine-Valine-Alanine-Valine; PEG, poly(ethylene glycol); PCR, polymerase chain reaction; PEG-DMA, PEG-dimethylacrylate; PEG-TMA, PEG-trimethylacrylate; OMMA, oxiran-2-ylmethyl methacrylate; POMO, 2-((prop-2-ynyloxy)methyl)oxirane; SMG, submandibular salivary gland; transepithelial resistance, TER

描述（由申请人提供）：目前组织工程领域面临的最重大挑战之一是在工程组织中刺激和/或维持上皮细胞分化的能力。由于上皮细胞分泌功能对器官功能至关重要，因此了解调节和维持细胞分化的机制对于再生或改造功能组织至关重要。人造的功能性唾液分泌唾液腺结构将大大提高患有唾液功能减退症的患者的生活质量，但这种工程组织尚未产生，并且体外唾液腺泡分化仍然难以维持。细胞微环境在细胞分化中发挥着重要作用，但人们对调节细胞分化的微环境的具体特征知之甚少。工程支架通常无法模拟微环境，事实上，组织工程最有效的支架是源自活组织的脱细胞支架。由于组织工程的目标是能够合成优于脱细胞天然支架的支架，因此有必要了解天然细胞外基质的基本特征（化学、机械/弹性和拓扑特性）如何影响细胞分化。最近的研究已经确定了微环境的弹性在决定间充质干细胞分化程度方面的重要性；然而，弹性在调节上皮组织分化中的重要性尚未得到研究。化学信号，包括生长调节因子和结合位点，已得到更广泛的研究，但化学信号与弹性之间的关系仍然很大程度上未知。该项目的总体目标是确定基质弹性和细胞结合位点密度在调节下颌下唾液腺（SMG）腺泡细胞分化中的功能。我们将利用细胞系和胚胎原代细胞，通过新型可调谐 PEG 水凝胶支架来实现这一目标。我们假设腺泡细胞分化需要具有最佳细胞结合位点的顺应性细胞外基质，该基质在非典型基质刚性下会被破坏。为了解决这一假设，我们建议使用可调节的聚乙二醇（PEG）基水凝胶来实现三个具体目标：目标 1. 开发包含不同水平结合位点的不同弹性的基于 PEG 的水凝胶。目标 2. 确定弹性和细胞组织在使用水凝胶支架调节腺泡细胞分化中的贡献。目标 3. 使用双层光刻技术创建用于原代细胞的微孔支架。缩写：AFM，原子力显微镜； Col IV，IV 型胶原蛋白； ECM，细胞外基质； GFP，绿色荧光蛋白； IKVAV，异亮氨酸-赖氨酸-缬氨酸-丙氨酸-缬氨酸； PEG，聚乙二醇； PCR、聚合酶链式反应； PEG-DMA、PEG-二甲基丙烯酸酯； PEG-TMA、PEG-三甲基丙烯酸酯； OMMA，环氧乙烷-2-基甲基丙烯酸甲酯； POMO，2-((丙-2-炔氧基)甲基)环氧乙烷； SMG，颌下唾液腺；跨上皮电阻