NIDCR Individual Predoctoral Dental Scientist Fellowship

描述（由申请人提供）：伤口愈合是一个复杂的生物学过程，需要多种细胞类型和动态细胞外基质（ECM）微环境在四个连续阶段的协调：止血、炎症、增殖和重塑。虽然伤口愈合的止血、炎症和一定程度上的增殖阶段已经得到了很好的研究，但对重塑阶段的调控却很少受到关注。在重塑阶段，血管生成过程是完整的，抗血管生成机制在去除不必要的血管中起关键作用。血管退化与ECM重塑同时发生，这是一个重组和加强基质成分以获得机械强度的过程。在大多数伤口中，伤口愈合的最终结果是瘢痕形成，因为ECM从未完全恢复正常结构。我们的长期目标是了解调节伤口消退和疤痕形成的因素。我们实验室的初步研究表明，色素上皮衍生因子（PEDF）是一个重要的内源性因子，在重塑伤口中调节血管退化。最近的研究表明，PEDF也可能与内皮细胞（EC）以外的细胞类型（包括成纤维细胞）有显著的相互作用。此外，PEDF的作用可能受到其与ECM分子（如胶原I、胶原III和肝素）结合的影响。目前的建议将探讨PEDF影响伤口血管系统和疤痕形成的机制。该建议的中心假设是PEDF通过各种ECM结合伙伴在愈合过程中调节血管消退和疤痕形成。本研究的具体目的是：1)确定PEDF对创面血管生成和瘢痕形成的影响；2)分析PEDF受体在创面中的分布；3)研究PEDF与其ECM结合伙伴在创面中的具体功能相互作用。目的1将涉及PEDF-/-小鼠伤口愈合的体内研究，以确定PEDF作为抗血管生成和ECM重塑因子的功能。在Aim 2中，免疫组织化学和间接免疫荧光研究将定位已知的PEDF受体到参与伤口愈合的主要细胞类型。目标3将涉及利用ECM-PEDF复合物的功能获得研究。这些研究将确定ECM结合PEDF对伤口愈合结果的协同作用，包括血管生长和消退、ECM成熟、疤痕形成和伤口断裂强度。这些实验将为研究调节皮肤伤口愈合重塑阶段的机制提供洞见，并可能为组织再生、纤维化和癌症提供未来的治疗选择。

DESCRIPTION (provided by applicant): Wound healing is a complex biological process that requires coordination among multiple cell types and the dynamic extracellular matrix (ECM) microenvironment in four sequential phases: hemostasis, inflammation, proliferation, and remodeling. Although the hemostatic, inflammatory, and to some extent the proliferative phases of wound healing have been well studied, the regulation of the remodeling phase has received less attention. In the remodeling phase, the angiogenic process is complete and anti-angiogenic mechanisms play a key role in removing unnecessary vessels. Vessel regression occurs simultaneously with ECM remodeling, a process that reorganizes and reinforces matrix components to achieve mechanical strength. In most wounds, the end result of wound healing is scar formation, as the ECM never fully returns to normal architecture. Our long term goal is to understand the factors that regulate wound resolution and scar formation. Preliminary studies in our lab demonstrate that pigment epithelium-derived factor (PEDF) is an important endogenous factor that regulates vascular regression in remodeling wounds. Recent studies suggest that PEDF may also have significant interactions with cell types other than endothelial cells (EC), including fibroblasts. Moreover, the effect of PEDF may be influenced by its binding to ECM molecules such as collagen I, collagen III, and heparin. The current proposal will explore the mechanisms by which PEDF influences wound vasculature and scar formation. The central hypothesis of this proposal is that PEDF works through various ECM binding partners to both regulate vessel regression and scar formation during healing. The specific aims of this study are 1) to determine the influence of PEDF on wound angiogenesis and scar formation, 2) to analyze the distribution of PEDF receptors in the wound, and 3) to investigate the specific functional interactions between PEDF and its ECM binding partners in wounds. Aim 1 will involve in vivo studies of wound healing in PEDF-/- mice to determine PEDF's function as an anti-angiogenic and ECM remodeling factor. In Aim 2, immunohistochemical and indirect immunofluorescence studies will localize known PEDF receptors to major cell types that are involved in wound healing. Aim 3 will involve gain-of-function studies utilizing ECM-PEDF complexes. These studies will determine the synergistic effect of ECM bound PEDF on wound healing outcomes, including blood vessel growth and regression, ECM maturation, scar formation, and wound breaking strength. These experiments will provide insight into the mechanisms that regulate the remodeling phase of dermal wound healing, and may suggest future therapeutic options for tissue regeneration, fibrosis and cancer.