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

• 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
• 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' 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

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）：组织工程领域目前面临的最重要的挑战之一是刺激和/或维持工程组织中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工程化功能组织至关重要。人工功能性唾液分泌唾液腺构建体将大大提高患有唾液功能减退的患者的生活质量，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起着重要作用，但关于调节细胞分化的微环境的具体特征知之甚少。工程支架通常不能模拟微环境，事实上，用于组织工程的最有效的支架是来自活组织的脱细胞支架。由于组织工程的目标是能够合成性能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性（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确定间充质干细胞分化程度中的重要性;然而，弹性在上皮组织分化调节中的意义尚未研究。化学信号，包括生长调节因子和结合位点，已经得到了更广泛的研究，但化学信号和弹性之间的关系在很大程度上仍然未知。本研究的主要目的是明确基质弹性和细胞结合位点密度在调节下颌下腺腺泡细胞分化中的作用。我们将使用细胞系和胚胎原代细胞，以解决这一目标，使用新的可调PEG水凝胶支架。我们假设，腺泡细胞分化需要一个顺应性的细胞外基质具有最佳的细胞结合位点，这是在非典型基板刚性破坏。为了解决这一假设，我们建议在三个具体目标中使用可调聚乙二醇（PEG）基水凝胶：目标1。开发具有不同弹性的PEG基水凝胶，其中包含不同水平的结合位点。目标二。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作用。目标3。使用双层光刻法来创建用于原代细胞的微孔支架。缩略语：AFM，原子力显微镜; Col IV，IV型胶原; 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，聚合酶链反应; PEG-DMA，PEG-丙烯酸二甲酯; PEG-TMA，PEG-丙烯酸三甲酯; OMMA，甲基丙烯酸环氧乙烷-2-基甲酯; POMO，2-（（丙-2-炔氧基）甲基）环氧乙烷; SMG，下颌下腺;经上皮电阻，TER