机械应力条件下表皮干细胞的动力学变化

目的 观察皮肤软组织扩张术后表皮干细胞的变化,探讨应力作用下细胞的动力学改变及皮肤软组织扩张术的力学机制. 方法 标本取自行头部扩张术Ⅱ期手术患者.根据所取标本位置将试验分为:(1)扩张器中心组,所取头皮距扩张器中心约3 cm;(2)扩张器侧壁组,所取头皮位于扩张皮肤的侧壁;(3)对照组,未扩张的头皮.各组标本行HE染色,光学显微镜下观察其组织结构;免疫组织化学染色后在倒置相差显微镜下观察细胞角蛋白19(CK19)阳性细胞的分化与分布特征. 结果 HE染色可见两试验组表皮层凹凸不平,皱褶明显,表皮层相对增厚、层次增多,分布密集;免疫组织化学染色后两试验组在基底层之外可见复层现象及少量的成团或散在分布的CK19阳性细胞,邻近有"镂空"结构形成.而对照组未见上述现象. 结论机械扩张后表皮干细胞在分裂增殖的同时,出现异位分布并伴有"镂空"结构,其现象可能与表皮基底层细胞的动力学改变有关.

Preliminary investigation on the dynamic change in epidermal stem cells under mechanical stress in vivo

OBJECTIVE: To observe the distribution of epidermal stem cell (ESC) after soft tissue expansion, and to explore dynamic change in ESC under mechanical stress and kinetic mechanism of skin expansion. METHODS: Skin samples were collected from patients after expansion of the scalp. They were divided into three groups: A group (scalp harvested 3 cm away from the center of dilator), B group (scalp tissues at the edge of dilator), and control group (scalp without dilatation). The tissue structures were observed with optical microscope with HE staining. The distribution and differentiation characteristics of cell keratin 19 (CK19) positive cells were observed with inverted phase contrast microscope after immunohistochemistry staining. RESULTS: HE staining showed that the epidermis was thickened and distributed densely with uneven, rugged and increased layers in A, B groups. With immunohistochemistry staining, CK19 positive cells appeared in multilayers in basal membrane, a few of them were in cluster or dispersed , with" hollowing" structure formation. These phenomena were not seen in control group. CONCLUSION: ESC can proliferate with abnormal distribution and "hollowing" structure formation after mechanical dilatation, which may be related to dynamic changes in basal layer cells.