Fate of migrating epidermal cells during the wound healing using the injured-epithelia specific gene recombination.

对皮肤组织的损伤会引起急性修复反应，目的是恢复上皮的连续性，这是正常皮肤屏障功能所必需的。伤口边缘的表皮角质形成细胞被用于伤口部位的再上皮化。然而，与单层上皮相比，复层上皮再上皮化的机制并不容易理解。虽然角质形成细胞在伤口边缘以层状薄片的形式迁移，但在这一重要过程中，祖细胞和分化角质形成细胞的相对贡献和最终命运尚不清楚。在本研究中，我们使用转基因技术来诱导伤口特异性基因重组。我们制备了两种类型的转基因，以引入损伤的表皮特异性基因修饰和诱导损伤的基底层以上角质形成细胞的特异性基因标记。一种目的是在人角蛋白6启动子作用下与受损的角质形成细胞特异性地表达cre重组酶，另一种是利用GFP和半乳糖苷酶双标记蛋白进行基因标记，我们用双转基因小鼠追踪在伤口边缘激活的基底上皮细胞的迁移。通过这项转基因工作，我们可以得出一个长期的问题，即基底层以上的角质形成细胞是否能够恢复有丝分裂特性并迁移到溃疡表面。创面边缘的基底层以上角质形成细胞可以迁移到溃疡表面，但即使在再上皮化后也无法恢复有丝分裂活性。

Injury to the skin tissue elicits an acute repair response aimed at restoring the epithelial continuity, which is essential to a normal skin barrier function. Epidermal keratinocytes at the wound edge are recruited for the re-epithelialization of the wound site. However, the mechanism of the re-epithelialization of the stratified epithelia is not easily understood compared with that of the simple epithelia. While the migration of keratinocytes occurs in the form of a stratified sheet at the wound edge, the relative contribution and ultimate fate of progenitor and differentiating keratinocytes during this vital process remains unclear. In this study, we used the transgenic technology to induce the wound specific gene recombination. We prepared two types of transgenes to introduce the injured epidermis specific gene modification and to induce the injured-suprabasal keratinocytes specific gene marking. One construct aimed to express the cre recombinase with the injured keratinocytes specific manner under the human keratin 6 promoter, and the other one was used for gene marking using the double marker proteins, GFP and galactosidase, We used the double transgenic mice to trace the migration of the suprabasal keratinocytes activated at the wound edge. By this transgenic work we could conclude the long term question, whether the suprabasal keratinocytes could recover the mitogenic property and migrate into the ulcerative surface or not. The suprabasal keratinocytes at the wound edge are possible to migrate into the ulcerative surfaces but never recover the mitotic activity even after the re-epithelialization.