Recapitulation of the salivary gland niche ex vivo for stem cell-based therpies

项目摘要 唾液是保护口腔健康的重要防御机制。唾液腺功能减退 导致不受控制的严重口腔疾病，导致生活质量严重受损。SGS 高度分化，一旦被治疗破坏， 疾病（如放射治疗或自身免疫性干燥综合征）。因此发展 保护或再生SGs分泌功能的策略对于成功的 管理这些病人。细胞外基质（ECM）是一种独特的细胞外基质的主要成分。 微环境或“生态位”，指导和维持细胞在体内的分化功能 目前，基于干细胞的再生疗法存在两个主要障碍：1）有限的细胞毒性。 多能干细胞的可用性和2）选择性控制分化的困难 将多能干细胞转化为所需的细胞谱系。我们的研究小组开发了一种新型ECM- 用于从骨扩增多能间充质干细胞（MSC）的基于细胞培养的系统 骨髓和3D丝素蛋白支架（SFS）用于离体建立SG生态位。所以我们 建议测试的假设，唾液腺特异性ECM（SG-ECM），建立在自然的三维 SFS是一种能够指导MSC增殖和分化为功能性SG的仿生生态位 祖细胞在具体目标1中，我们将优化用于生产SG的支架特性。 原代SG上皮细胞对SFS的ECM。在具体目标2中，我们将确定 最佳SG-ECM包被的SFS引导MSC分化为SG细胞谱系。具体目标3中， 将在SG损伤的体内模型中评价在特定目标2中产生的细胞的功效 由于辐射。 该提案的新奇包括（1）测试我们的新细胞培养技术，以获得足够的细胞培养物。 来自人骨髓的多能MSC的数量，以修复或再生SG功能;（2）测试 一种天然的3D支架材料，并优化其性能，以支持SG再生和组织 （3）检测SG衍生的ECM包被的支架在指导MSC分化中的作用 SG细胞谱系和功能性SG单位，以及（4）组建多学科团队进行研究 基于干细胞的SG疗法。这项研究的成功可能会导致新的治疗策略， SG功能障碍的临床管理。

Project Summary Saliva is an important defense mechanism for protecting oral health. Salivary gland (SG) hypofunction results in uncontrolled and severe oral diseases that lead to severely compromised quality of life. SGs are highly differentiated and have little regenerative capacity once they are destroyed by therapy or disease (e.g. radiation therapy or autoimmune Sjögren’s syndrome). Therefore, the development of strategies for preserving or regenerating the secretory function of SGs is essential for successful management of these patients. The extracellular matrix (ECM) is a major component of the unique microenvironment or “niche” that directs and maintains the differentiated functions of cells in vivo Presently, there are two main obstacles to stem cell-based regenerative therapies: 1) the limited availability of multi-potent stem cells and 2) the difficulty of selectively controlling the differentiation multi-potent stem cells into the desired cell lineage. Our research group has developed a novel ECM- based cell culture system for expanding multipotent mesenchymal stem cells (MSCs) from bone marrow and 3D silk fibroin scaffolds (SFS) for establishing the SG niche ex vivo. Therefore, we propose to test the hypothesis that salivary gland specific ECM (SG-ECM), established on a natural 3D SFS, is a biomimetic niche capable of directing MSC proliferation and differentiation into functional SG progenitor cells. In Specific Aim 1, we will optimize scaffold characteristics for the production of SG- ECM on the SFS by primary SG epithelial cells. In Specific Aim 2, we will determine whether the optimal SG-ECM coated SFS directs MSC differentiation into the SG cell lineage. In Specific Aim 3, the efficacy of the cells, produced in Specific Aim 2, will be evaluated in an in vivo model of SG damage due to irradiation. The novelty of this proposal includes (1) testing our novel cell culture technology to obtain sufficient numbers of multipotent MSCs from human bone marrow to repair or regenerate SG function; (2) testing a natural 3D scaffold material and optimizing its properties for supporting SG regeneration and tissue engineering; (3) examining the role of SG-derived ECM coated scaffolds in directing MSC differentiation to the SG cell lineage and functional SG units, and (4) assembling a multidisciplinary team to study stem-cell based SG therapy. The success of this study may lead to new therapeutic strategies for clinical management of SG dysfunction.