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: 8257739
• 负责人: MELINDA LARSEN
• 金额: $ 22.8万
• 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 2013-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8257739
• 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 PUBLIC HEALTH RELEVANCE: This project will identify the necessary elastic and cell binding characteristics of a cellular scaffold to promote acinar differentiation. These results will provide a framework for future identification of other factors that influence acinar generation in a future proposal. These studies will eventually make possible the engineering of an artificial scaffold to alleviate symptoms in patients suffering from Sjogren's syndrome and other causes of salivary hypofunction, or dry mouth.

描述（由申请人提供）：当前面临组织工程领域的最重大挑战之一是刺激和/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于器官功能至关重要，因此了解调节和维持细胞分化的机制对于再生或工程功能组织至关重要。人造功能性的唾液腺分泌唾液腺结构将大大提高患有唾液功能低下的患者的生活质量，但是尚未产生这种工程组织，并且在体外唾液毒素分化仍然难以维持。细胞微环境在细胞分化中起着重要的作用，但在调节细胞分化的微环境的特定特征方面，知之甚少。工程脚手架通常无法模仿微环境，实际上，组织工程的最有效的脚手架是源自活组织的脱细胞脚手架。由于组织工程的目标是能够合成超过脱细胞的脚手架的支架，因此有必要了解自然细胞外基质（化学，机械/弹性和拓扑特性）的基本特征如何影响细胞的分化。最近的研究确定了微环境在确定间质干细胞分化程度上的弹性。但是，尚未研究弹性在上皮组织分化调节中的重要性。化学信号（包括生长调节因素和结合位点）已经进行了更广泛的研究，但是化学信号与弹性之间的关系仍然很大程度上未知。该项目的总体目的是定义底物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。我们将使用细胞系和胚胎原代细胞使用新型可调PEG水凝胶支架来解决这一目标。我们假设腺泡细胞分化需要一个具有最佳细胞结合位点的符合符合的细胞外基质，该基质在非典型的底物刚度处被破坏。为了解决这一假设，我们建议在三个特定的目的中使用可调节的聚乙烯 - 基准（PEG）水凝胶：AIM 1。开发基于PEG的水凝胶，具有不同含量的弹性，其中包含不同水平的结合位点。目标2。确定使用水凝胶支架调节腺泡细胞分化的弹性和细胞组织的贡献。 AIM 3。使用双层光刻来创建微孔支架，以与主细胞一起使用。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 - 丙氨酸 - 丙氨酸 - 谷氨酸； PEG，聚乙二醇）； PCR，聚合酶链反应； PEG-DMA，钉二甲基丙烯酸酯； PEG-TMA，PEG-三甲基丙烯酸酯； OMMA，氧二 - 甲基甲基丙烯酸酯； Pomo，2-（（Prop-2-ynyloxy）甲基）Oxirane； SMG，下颌下唾液腺； ternepithepithial抗性，ter 公共卫生相关性：该项目将确定细胞支架的必要弹性和细胞结合特性，以促进腺泡分化。这些结果将为未来影响未来建议中影响腺泡产生的其他因素提供一个框架。这些研究最终将使人工脚手架的工程可能减轻患有Sjogren综合征的患者的症状和其他唾液功能低下或口干的原因。