Engineering Mesenchymal Stem Cells for More Rapid Wound Healing

1066585 Dawson知识专长：皮肤损伤导致伤口愈合过程激活，这是一系列复杂的事件，包括炎症、肉芽组织产生、上皮再生和瘢痕组织形成。生长因子在介导伤口愈合阶段中是必不可少的，伤口愈合从表皮损伤到瘢痕组织形成持续进行。当伤口愈合过程在慢性炎症状态下停滞时，老年患者和患有慢性疾病的患者发展为慢性伤口。与慢性伤口形成相关的两个因素是：（1）生长因子的产生受损和（2）血管生成减少。基于细胞的疗法，包括成纤维细胞和间充质干细胞（MSC），以前曾被用于促进更快的伤口愈合;然而，这些疗法的有效性受到伤口床中细胞迁移和植入不良的限制。拟议的研究将集中在伤口床中MSC迁移的优化。假设在整个伤口床中散布的迁移MSC将有助于肉芽组织的形成，这将使伤口收缩以更快地闭合伤口。改善的MSC迁移也可以改善生长因子的时空活性，因为它们将从散布在整个伤口组织中的MSC分泌。血小板分泌的可溶性蛋白，如PDGF和TGF-？你好，介导骨髓来源的细胞向伤口组织的迁移;然而，关于这些蛋白质对MSC的微观机械性质的影响知之甚少。使用定量实时显微镜技术，包括粒子跟踪微流变学和时间推移荧光显微镜，PDGF，TGF-？你好，和/或缺氧对细胞内流变学、细胞骨架组织和与细胞粘附分子的相互作用的影响。体外transwell迁移研究将用于测量所选刺激对MSC迁移的影响。这些技术将一起用于确定迁移MSC的机械和粘附特性。优化的MSC，发现具有与增加的迁移相关的机械性能，将在体内测试伤口床中的迁移。然后，MSC将被基因工程化以表达血管内皮生长因子，这将用于促进更快速的血管生成。这些研究将产生关于血小板分泌的可溶性蛋白对MSC的机械和粘附特性的影响的基本信息。这些信息将用于开发基于MSC的伤口愈合疗法。

1066585DawsonIntellectual Merit: Injury to the skin results in the activation of the wound healing process, a complex series of events that includes inflammation, production of granulation tissue, re-epithelialization, and scar tissue formation. Growth factors are essential in mediating the stages of wound healing, which proceed continuously from the time of epidermal damage to scar tissue formation. Elderly patients and patients suffering from chronic illness develop chronic wounds when the wound healing process is arrested in a state of chronic inflammation. Two of the factors that have been associated with the formation of chronic wounds are: (1) impaired production of growth factors and (2) reduced angiogensis. Cell-based therapies, including fibroblasts and mesenchymal stem cells (MSCs), have previously been used to promote more rapid wound healing; however, the effectiveness of these therapies was limited by poor cell migration and engraftment in the wound bed. The proposed studies will focus on the optimization of MSC migration in the wound bed. It is hypothesized that migrating MSCs that disseminate throughout the wound bed will contribute to the formation of granulation tissue, which will constrict the wound for more rapid wound closure. Improved MSC migration may also improve the spatio-temporal activity of the growth factors since they will be secreted from MSCs disseminated throughout the wound tissue. Platelet-secreted soluble proteins, such as PDGF and TGF-?Ò?¡, mediate the migration of bone marrow derived cells to wound tissues; however, little is known about the effects of these proteins on the microscopic mechanical properties of MSCs. Using quantitative real-time microscopy techniques, including particle tracking microrheology and time-lapsed fluorescent microscopy, the effects of PDGF, TGF-?Ò?¡, and/or hypoxia on intracellular rheology, cytoskeletal organization, and interaction with cell adhesion molecules will be monitored. In vitro transwell migration studies will be used to measure the effects of selected stimuli on MSC migration. Together these techniques will be used to determine the mechanical and adhesive properties of migratory MSCs. Optimized MSCs, found to possess the mechanical properties associated with increased migration, will be tested in vivo for migration in the wound bed. MSCs will then be genetically engineered to express vascular endothelial growth factor, which will be used to promote more rapid angiogenesis. The proposed studies will generate fundamental information about the effects of platelet secreted soluble proteins on the mechanical and adhesive properties of MSCs. This information will be utilized in the development of MSC-based therapies for wound healing.