Graduate Institute of Medical Sciences, Department of Family Medicine, Taipei Municipal Wan Fang Hospital, College of Medicine, Taipei Medical University, Taipei, Taiwan.
Int J Exp Pathol. 2013 Jun;94(3):188-94. doi: 10.1111/iep.12019. Epub 2013 Feb 27.
Ageing dynamically disrupts the multilayered supporting components of the skin that are held together by cell adhesion molecules (CAMs). Skin specimens from 33 female Chinese patients undergoing lower blepharoplasty were divided into three age groups and examined by haematoxylin and eosin (H&E) staining, immunohistochemistry (IHC) and Elastica-van Gieson (EVG) stains, western blotting, surface electron microscopy (SEM) and biomechanical tension analysis. The SEM density (skin surface topology) showed a negative linear relationship with age. The triangular pattern of the skin surface in the younger group gradually broke down into quadrangular and irregular patterns in the older group. Collagens and elastic fibres in the dermis showed anisotropy and decreased density in the older groups compared with the younger group, especially in the papillary dermis. Anisotropy means that physical properties differ according to the direction of measurement. E-cadherin and integrin αv (whose functions are to bind epidermal and dermal elements respectively) increased and decreased, respectively, in the oldest group. Skin resilience decreased significantly in this group under repetitive stress. In conclusion, a loss of skin surface textures, integrin αv expressions, epidermal-dermal connections and dermal compactness led to the multilayered structure of the skin becoming separated. This in turn decreased resilience during ageing. These findings may therefore explain why aged skins cannot tolerate repetitive facial expressions, and why this action produces further dynamic wrinkles.
年龄增长会动态破坏皮肤的多层支撑成分,这些成分由细胞黏附分子(CAMs)连接。对 33 名接受下眼睑整形术的中国女性患者的皮肤标本进行研究,将其分为三组,通过苏木精和伊红(H&E)染色、免疫组织化学(IHC)和弹性纤维-van Gieson(EVG)染色、western blot、表面电子显微镜(SEM)和生物力学张力分析进行检测。SEM 密度(皮肤表面拓扑结构)与年龄呈负线性关系。年轻组的三角形皮肤表面模式逐渐在老年组中演变为四边形和不规则形状。与年轻组相比,老年组真皮中的胶原和弹性纤维表现出各向异性和密度降低,尤其是在乳头真皮中。各向异性是指物理性质随测量方向而变化。E-钙黏蛋白和整合素αv(其功能分别是连接表皮和真皮成分)在最年长组中分别增加和减少。在这个组中,皮肤弹性在重复压力下显著降低。总之,皮肤表面纹理、整合素αv 表达、表皮-真皮连接和真皮紧实度的丧失导致皮肤的多层结构分离。这反过来又降低了皮肤在衰老过程中的弹性。这些发现可以解释为什么老化的皮肤不能耐受重复的面部表情,以及为什么这种动作会产生更多的动态皱纹。