Re-epithelialization is a crucial process to reestablish the protective barrier upon wounding of the skin. Although this process is well described for wounds where the complete epidermis and dermis is damaged, little is known about the re-epithelialization strategy in more frequently occurring smaller scratch wounds in which structures such as the hair follicles and sweat glands stay intact. To study this, we established a scratch wound model to follow individual keratinocytes in all epidermal layers in the back skin of mice by intravital microscopy. We discover that keratinocytes adopt a re-epithelialization strategy that enables them to bypass immobile obstacles such as hair follicles. Wound-induced cell loss is replenished by proliferation in a distinct zone away from the wound and this proliferation does not affect overall migration pattern. Whereas suprabasal keratinocytes are rather passive, basal keratinocytes move as a sheet of independently migrating cells into the wound, thereby constantly changing their direct neighboring cells enabling them to bypass intact obstacles. This re-epithelialization strategy results in a fast re-establishment of the protective skin barrier upon wounding.

中文翻译：

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划伤引起的部分皮肤伤口通过独立迁移的角质形成细胞片重新上皮化。

再上皮化是在皮肤受伤时重建保护屏障的关键过程。尽管该过程在完整表皮和真皮受损的伤口中得到了很好的描述，但对于更频繁发生的较小划痕伤口中的再上皮化策略知之甚少，其中毛囊和汗腺等结构保持完整。为了研究这一点，我们建立了一个划痕模型，通过活体显微镜跟踪小鼠背部皮肤所有表皮层中的单个角质形成细胞。我们发现角质形成细胞采用再上皮化策略，使它们能够绕过毛囊等固定障碍。伤口诱导的细胞损失由远离伤口的不同区域的增殖补充，这种增殖不影响整体迁移模式。尽管基底上角质形成细胞相当被动，但基底角质形成细胞作为一片独立迁移的细胞移动到伤口中，从而不断改变它们的直接相邻细胞，使它们能够绕过完整的障碍物。这种再上皮化策略导致在受伤时快速重建保护性皮肤屏障。