Skin Regeneration with Stem Cells and Scaffolds

说明（由申请人提供）：在受损皮肤中，再生与填充和表面修复不同。瘢痕愈合是由于真皮结构的错误、旺盛的重建和缺乏附属物的表皮的形成。这项由多名研究者提出的最重要的假设是，耳部伤口再生的MRL/MpJ小鼠在伤口愈合过程中表达有利于再生的蛋白质。这一概念得到了我们最近发表的工作和我们目前的发现的支持，即MRL伤口蛋白质组与其他小鼠品系有明显的差异。我们已经发表的证据表明，骨髓是伤口成纤维细胞的丰富来源，来自MRL小鼠的间充质干细胞（MSC）促进愈合，部分原因是由于升高的sFRP-1。第一个目标是使用一种新颖、精确的自由电子激光手术方法，确定MRL内再生和非再生伤口之间以及不同菌株之间的关键蛋白质组学差异。分析将用最先进的高分辨率蛋白质组学技术完成，并通过免疫组织化学进行验证。第二个目标是确定几种干细胞群体的迁移和分化如何受到已知和新发现的再生特异性因子的影响，这种新型微流控装置可以产生复杂的二维浓度梯度。进一步的验证将使用新的伤口室。第三个目标是建立一个基于新型聚氨酯化学的支架，提供一个三维环境，在控制条件下，可以释放招募干细胞或促进干细胞活性的因素，以驱动皮肤的再生反应，通常通过疤痕愈合。该项目将先测试已知的候选项目，然后再测试新发现的候选项目。再生的关键标准将是结缔组织结构的恢复，包括功能性弹性纤维的形成和毛囊形成的开始。该合资企业的转化成果将是鉴定促进再生的分子，利用骨髓来源的细胞促进再生，开发用于研究细胞行为的新设备，以及生产用于招募、分化和递送促进全功能修复的形态原的生物活性支架。这将通过在组织分析，蛋白质组学，干细胞生物学，微流体学和聚合物化学方面具有专业知识的经验丰富的研究人员团队的合作来完成。公共卫生相关性：伤口和烧伤经常留下疤痕，不能再生皮肤的原始结构。某些品系的老鼠在身体某些部位的皮肤愈合得更好，部分原因可能是它们的循环干细胞或它们被招募到伤口的方式不同。这是一项研究，旨在识别正常愈合和再生之间的细胞信号，看看它们如何影响干细胞的行为，并设计一种临时的合成支架，可以传递这些再生信号，以恢复皮肤的结构和功能。

DESCRIPTION (provided by applicant): In damaged skin, regeneration is not the same as filling and resurfacing. Healing by scarring results from the faulty, exuberant reconstruction of the dermal architecture and the formation of an epidermis lacking appendages. The overriding hypothesis of this multi-investigator proposal is that the MRL/MpJ mouse, in which ear wounds regenerate, expresses proteins during wound healing that favor regeneration. This concept is bolstered by our recently published work and our current findings that the MRL wound proteome has distinct differences from other mouse strains. We have published evidence that the bone marrow is a rich source of wound fibroblasts, and mesenchymal stem cells (MSC) from the MRL mouse enhance healing due in part to elevated sFRP-1. The first goal is to identify the key proteomic differences between regenerating and non-regenerating wounds within the MRL and between strains, using a novel, precise surgical method with the free-electron laser. Analysis will be accomplished with state of the art, high-resolution proteomic techniques and verified by immunohistochemistry. The second goal is to determine how the migration and differentiation of several stem cell populations is affected by known and newly-identified, regeneration-specific factors in a novel, microfluidic device that can generate complex, two-dimensional concentration gradients. Further validation will use novel wound chambers. The third goal is to build a scaffold, based on a novel polyurethane chemistry, to provide a three-dimensional environment into which factors that recruit stem cells or promote stem cell activity can be released, under controlled conditions, to drive a regenerative response in skin that normally heals by scarring. The project will test known candidates and then those newly identified. The key criteria for regeneration will be restoration of connective tissue architecture, including the formation of functional elastic fibers and the initiation of hair follicle formation. The translational outcome of this joint venture will be the identification of regeneration-promoting molecules, the use of bone marrow-derived cells to promote regeneration, the development of a new device for studying cell behavior, and the production of a bioactive scaffold for recruitment, differentiation, and delivery of morphogens that promote fully functional repair. This will be accomplished by the collaboration of a seasoned team of investigators with expertise in tissue analysis, proteomics, stem cell biology, microfluidics, and polymer chemistry. PUBLIC HEALTH RELEVANCE: Wounds and burns frequently scar and fail to regenerate the original architecture of the skin. Certain strains of mice heal skin much better in some regions of their body, and part of this may be due to differences in their circulating stem cells or the way they are recruited to the wound. This is a study to identify the cell signals that differ between normal healing and regeneration, to see how they affect the behavior of stem cells, and to devise a temporary, synthetic scaffold that can deliver these regenerative signals to restore skin structure and function.