MATRIX REGULATION OF GINGIVAL RE-EPITHELIZATION

为了保持口被的完整性 牙龈再上皮化。 在这个过程中，细胞的边缘， 伤口由新环境诱导附着、扩散、迁移， 最终通过创伤细胞外基质（ECM）侵入。 来自该实验室和其他实验室的大量数据表明， 一组ECM受体，整合素，在介导 细胞与ECM的相互作用。 该提案旨在调查 损伤后整合素受体的一个亚群 促进活化的角质形成细胞最初的向外迁移， 伤口基质 然后继续迁移，直到细胞接触 第二，相对的伤口边缘，此时运动受到限制， 一组整合素介导的信号限制运动并诱导形成 新的半桥粒和基底膜。 重建的过程- 上皮形成也可能受伤口细胞因子调节， 如TGF-β，并需要角质形成细胞来制造特定的蛋白酶， 包括纤溶酶原激活剂和金属蛋白酶。 拟议的研究将使用新鲜解离的模型系统， 培养的人牙龈角质形成细胞（HGK），人牙龈的外植体， 上皮和组织活检，以分析三个阶段 伤口愈合的影响：稳定的 附着，如半桥粒。 整合素受体的激活 HGK解离后立即使用功能和 用于表征HGK与配体相互作用的生物化学测定 伤口床 整合素合成、组装和表达的变化 时间之后还将进行脉冲追踪标记和流式细胞术， 新鲜分离和培养的基础HGK。 配体特异性 特异性HGK整联蛋白将通过细胞附着、亲和力 层析和受体结合测定。 的可能性 某些整联蛋白，特别是α 3 β 1和α 6 β 4， 将审查在促进和制止移徙方面的重要性。 也 有待研究的是细胞迁移受HGK调节的可能性 含有epiligrin/kalinin的ECM地毯的沉积;表达 在HGK激活期间和之后的特定蛋白酶， 创伤细胞因子TGF-β对整联蛋白谱的调节作用， 迁移反应、ECM沉积和蛋白酶表达。 这些研究将增加对生物多样性的动态过程的理解。 稳定上皮附着的活化、迁移和重组 发生在牙龈伤口愈合过程中 它们与 牙周炎进展过程中连接上皮的迁移， 以及牙周炎后连接上皮的愈合 手术治疗

Continued integrity of the oral integument requires that the wounded gingiva re-epithelialize. In this process, cells at the margin of a wound are induced by a new environment to attach, spread, migrate, and eventually invade through the wound extracellular matrix (ECM). Substantial data from this and other laboratories indicate that the major group of ECM receptors, the integrins, are critical in mediating interactions of cells with the ECM. This proposal seeks to investigate the hypothesis that after injury one subset of integrin receptors promotes the initial out-migration of activated keratinocytes on the wound matrix. Migration then proceeds until the cells contact the opposing wound margin, at which time movement is restricted, and a second set of integrin-mediated signals restricts movement and induces formation of new hemidesmosomes and basement membrane. The process of re- epithelization is also likely to be modulated by wound cytokines, such as TGF-beta, and requires keratinocytes to elaborate specific proteases, including plasminogen activators and metalloproteinases. The proposed studies will use model systems of freshly dissociated and cultured human gingival keratinocytes (HGK), explants of human gingival epithelium, and tissue biopsies of human gingiva to analyze three stages of wound healing: activation, migration and reformation of stable attachment such as hemidesmosomes. The activation of integrin receptors immediately after HGK dissociation will be assessed using functional and biochemical assays to characterize HGK interaction with ligands in the wound bed. Changes in integrin synthesis, assembly, and expression over time will also be followed by pulse-chase labeling and flow cytometry of freshly dissociated and cultured basal HGK. The ligand specificity of specific HGK integrins will be analyzed by cell attachment, affinity chromatography, and receptor-binding assays. The possibility that certain integrins, particularly alpha3beta1 and alpha6beta4, are important in promoting and then halting migration will be examined. Also to be studied are the possibility that cell migration is regulated by HGK deposition of an ECM carpet containing epiligrin/kalinin; the expression of specific proteases during and after HGK activation and the possible modulating effect of the wound cytokine TGF-beta on integrin profiles, migratory response, ECM deposition, and protease expression. These studies will increase understanding of the dynamic processes of activation, migration and reorganization of stable epithelial attachments that occur in gingival wound healing. They are highly relevant to the migration of junctional epithelium in the progression of periodontitis, as well as healing of the junctional epithelium after periodontal surgical therapy.