Bernstein E F, Fisher L W, Li K, LeBaron R G, Tan E M, Uitto J
Department of Dermatology, Jefferson Medical College, Philadelphia, Pennsylvania, USA.
Lab Invest. 1995 Jun;72(6):662-9.
Chronic sun exposure induces numerous changes in exposed skin; the most striking histopathologic change is the massive accumulation of material with the staining characteristics of elastin, termed solar elastosis, in the superficial dermis. Previous studies have identified elastic fibers within areas of solar elastosis, as well as a decrease in collagen content. Recently, the large chondroitin sulfate (CS) proteoglycan, versican, has been identified in the dermis in association with elastic fibers, and the smaller CS proteoglycan, decorin, has been shown to codistribute with collagen fibers. Thus, changes in expression of these CS proteoglycans might be expected in photoaging and may help to explain the clinical alterations of chronically sun-exposed skin.
Immunohistochemical staining and confocal laser scanning microscopy for versican and decorin was performed on paired tissue samples from photoaged and non-sun-exposed skin taken from the same individuals. To investigate versican and decorin mRNA expression, Northern analysis was performed on paired fibroblast cultures derived from tissue explants of photoaged and non-sun-exposed skin.
Immunohistochemical staining and confocal laser scanning microscopy revealed a massive accumulation of versican localized to the abnormally large fibers comprising solar elastosis in the superficial and mid-dermis of photoaged specimens. Decorin staining was greatly decreased within the area of solar elastosis. Similarly, changes in mRNA were measured from fibroblast cultures, with a significant increase in versican mRNA in cultures derived from photoaged skin, whereas decorin mRNA levels were significantly decreased in photoaged skin.
This study provides further evidence for the close association of versican with elastic fibers and decorin with collagen fibers, even in the situation of abnormal fiber deposition occurring in photodamaged skin. In addition, changes in versican and decorin immunostaining are accompanied by similar alterations in gene expression.
长期日晒会使暴露在外的皮肤发生诸多变化；最显著的组织病理学变化是在浅表真皮中大量积聚具有弹性蛋白染色特征的物质，即日光性弹力纤维变性。以往研究已在日光性弹力纤维变性区域鉴定出弹性纤维，同时胶原含量减少。最近，已在真皮中鉴定出与弹性纤维相关的大分子硫酸软骨素（CS）蛋白聚糖多功能蛋白聚糖，并且已证明较小的CS蛋白聚糖核心蛋白聚糖与胶原纤维共分布。因此，这些CS蛋白聚糖的表达变化可能会出现在光老化过程中，并可能有助于解释长期日晒皮肤的临床改变。
对取自同一受试者的光老化皮肤和非日晒皮肤的配对组织样本进行多功能蛋白聚糖和核心蛋白聚糖的免疫组织化学染色及共聚焦激光扫描显微镜检查。为了研究多功能蛋白聚糖和核心蛋白聚糖的mRNA表达，对取自光老化皮肤和非日晒皮肤组织外植体的配对成纤维细胞培养物进行Northern分析。
免疫组织化学染色及共聚焦激光扫描显微镜检查显示，在光老化标本的浅表和中部真皮中，多功能蛋白聚糖大量积聚于构成日光性弹力纤维变性的异常粗大纤维中。在日光性弹力纤维变性区域，核心蛋白聚糖染色显著减少。同样，从成纤维细胞培养物中检测到mRNA变化，光老化皮肤来源的培养物中多功能蛋白聚糖mRNA显著增加，而光老化皮肤中核心蛋白聚糖mRNA水平显著降低。
本研究进一步证明，即使在光损伤皮肤中出现异常纤维沉积的情况下，多功能蛋白聚糖仍与弹性纤维密切相关，核心蛋白聚糖与胶原纤维密切相关。此外，多功能蛋白聚糖和核心蛋白聚糖免疫染色的变化伴随着基因表达的类似改变。
