KERATINOCYTE GALVANOTAXIS AND WOUND HEALING

皮肤创面角质形成细胞迁移的再上皮化 从伤口边缘作为伤口的重要和必要组成部分 治愈。这一建议提出了内生性的总体假设 受伤皮肤产生的电场提供了早期提示 角质形成细胞定向迁移。这项建议是建立在调查人员的 先前发现的阴极定向迁移(趋电性) 电场中的角质形成细胞与哺乳动物测量的电场相当 皮肤上的伤口。将要检验的假设是，一个电场 受体糖蛋白的侧向电泳法检测结果 细胞膜的平面，启动不对称信号事件 最终导致细胞定向迁移。不对称钙 据推测，内流是这一信号通路的一部分。 这项研究的总体目标是确定人的机制 角质形成细胞趋化。具体目标将调查1)可能 质膜靶向EGF受体、尿激酶型PA受体和 整合素，2)钙内流的调节3)下游信号通路 途径4)角质形成细胞分化对趋化电流的影响 适用于趋电的最佳电场参数。对于这些研究，3 将利用角质形成细胞迁移的模型，每个模型提供一个 明显的优势。1)单个细胞迁移的实时图像分析 提供量化细胞速度、净转运和 细胞传播的方向性。2)受伤的单层迁移可提供 角质形成细胞如何在损伤的连续薄片边缘移动的数据， 类似于正常的表皮。3)受伤的“皮肤替代物”，或复合材料 成纤维细胞与胶原凝胶复合的培养体系 利用分层培养的角质形成细胞，提供了一个机会 在三维基质的背景下检查再上皮化 表皮角质形成细胞和真皮细胞之间的细胞“串音” 成纤维细胞。 电刺激角质形成细胞定向迁移最终可能 为促进伤口愈合提供了强大的治疗工具， 尤其是在慢性、不可愈合的伤口上。

Re-epithelialization of a skin wound by the migration of keratinocytes from the wound margin as an important and necessary component of wound healing. This proposal forwards the overall hypothesis that endogenous electric fields, generated by the wounded skin, provide an early cue for directed keratinocyte migration. The proposal builds on the investigators' previous finding of cathodally-directed migration (galvanotaxis) of keratinocytes in electric fields equivalent to those measured in mammalian skin wounds. The hypothesis that will be tested is that an electric field results in the lateral electrophoresis of receptor glycoproteins within the plane of the cell membrane, initiating asymmetrical signaling events which culminate in directed cellular migration. Asymmetrical calcium influx is hypothesized to be a part of this signaling pathway. The overall aim of the study is to define the mechanism of human keratinocyte galvanotaxis. Specific aims will investigate 1) possible plasma membrane targets the EGF receptor, the urokinase PA receptor, and integrins, 2) modulation of Ca 2+ influx 3) downstream signaling kinase pathways 4) effects of keratinocyte differentiation on galvanotaxis 5) the electric field parameters optimal for galvanotaxis. For these studies, 3 models of keratinocyte migration will be utilized, each offering a distinct advantage. 1) Real-time image analysis of migrating single cells provides the ability to quantitate cell velocity, net translocation and directedness of cell travel. 2) A wounded monolayer migration provides data on how keratinocytes move at the edge of wounded contiguous sheet, akin to normal epidermis. 3) A wounded "skin equivalent", or composite culture system with fibroblasts incorporated into collagen gel overlaid with a stratified cultured keratinocytes, provides an opportunity to examine re-epithelialization in the context of a 3-dimensional matrix and with cellular 'crosstalk' between epidermal keratinocyte and dermal fibroblast. Electrical stimulation of directed keratinocyte migration may ultimately provide a powerful therapeutic tool for enhancing wound healing, particularly in chronic, non-healing wounds.