Amano Satoshi
Shiseido Research Center, Yokohama, Japan.
J Investig Dermatol Symp Proc. 2009 Aug;14(1):2-7. doi: 10.1038/jidsymp.2009.5.
Aging of sun-exposed skin is accelerated by three major environmental factors: UV radiation, dryness, and oxidation. UV radiation exposure is the most influential factor in skin aging (so-called photoaging). To find ways to protect against damage caused by UV exposure and to delay photoaging, we studied internal changes of sun-exposed skin compared with those of sun-protected skin. We found that the basement membrane (BM) at the dermal-epidermal junction (DEJ) of sun-exposed skin becomes damaged and multilayered and partly disrupted compared with that of sun-protected skin. BM plays important roles in maintaining a healthy epidermis and dermis, and repeated damage destabilizes the skin, accelerating the aging process. Matrix metalloproteinases (MMPs) and urinary plasminogen activator are increased in UV-irradiated skin. MMPs are detected in the cornified layer in sun-exposed skin, but not in sun-protected skin. Using skin-equivalent models, we found that MMPs and plasmin cause BM damage and that the reconstruction of BM is enhanced by inhibiting these proteinases, as well as by increasing the synthesis of BM components. Enhancement of BM repair mechanisms may be a useful strategy in retarding photoaging.Journal of Investigative Dermatology Symposium Proceedings (2009) 14, 2-7; doi:10.1038/jidsymp.2009.5.
紫外线辐射、干燥和氧化。紫外线辐射暴露是皮肤老化（即所谓的光老化）中最具影响力的因素。为了找到预防紫外线暴露造成损伤并延缓光老化的方法，我们研究了暴露于阳光下的皮肤与受到防晒保护的皮肤的内部变化。我们发现，与受到防晒保护的皮肤相比，暴露于阳光下的皮肤在真皮-表皮交界处（DEJ）的基底膜（BM）会受损、形成多层且部分遭到破坏。基底膜在维持健康的表皮和真皮方面发挥着重要作用，反复受损会使皮肤不稳定，加速老化过程。基质金属蛋白酶（MMPs）和尿纤溶酶原激活剂在紫外线照射的皮肤中会增加。在暴露于阳光下的皮肤的角质层中可检测到基质金属蛋白酶，而在受到防晒保护的皮肤中则检测不到。使用皮肤等效模型，我们发现基质金属蛋白酶和纤溶酶会导致基底膜损伤，并且通过抑制这些蛋白酶以及增加基底膜成分的合成可增强基底膜的重建。增强基底膜修复机制可能是延缓光老化的一种有效策略。《皮肤病学研究杂志研讨会论文集》（2009年）14卷，第2 - 7页；doi:10.1038/jidsymp.2009.5
