Tsukahara K, Takema Y, Moriwaki S, Tsuji N, Suzuki Y, Fujimura T, Imokawa G
Biological Science Laboratories, Kao Corporation, Akabane, Ichikai, Haga, Tochigi, Japan.
J Invest Dermatol. 2001 Sep;117(3):671-7. doi: 10.1046/j.0022-202x.2001.01450.x.
We previously reported that wrinkle formation in the skin following long-term ultraviolet B irradiation is accompanied by decreases in skin elasticity and the curling of elastic fibers in the dermis. We further showed that wrinkles could be repaired by treatment with retinoic acid and that this was concomitant with the recovery of skin elasticity ascribed to the repair of damaged elastic fibers. Those studies suggested that decreasing the tortuosity of dermal elastic fibers is an important factor involved in inhibiting or repairing wrinkle formation. Therefore, it is of particular interest to determine whether the inhibition of elastase activity in vivo would prevent the damage of dermal elastic fibers and might abolish wrinkle formation associated with the loss of skin elasticity. Because the major elastase in the skin under noninflammatory conditions is skin fibroblast elastase, we used a specific inhibitor of that enzyme to assess its biologic role in wrinkle formation. The hind limb skins of Sprague-Dawley rats were irradiated with ultraviolet B at a suberythemal dose three times a week for 6 wk. During that period, 0.1-10.0 mM N-phenetylphosphonyl-leucyl-tryptophane, an inhibitor of skin fibroblast elastase, was applied topically five times a week. N-phenetylphosphonyl-leucyl-tryptophane application at concentrations of 0.1-1.0 mM abolished wrinkle formation in a concentration-dependent manner, with a peak for inhibition at 1.0 mM. This inhibition was accompanied by a continued low tortuosity of dermal elastic fibers and a maintenance of skin elasticity. Measurement of elastase activity after 6 wk of ultraviolet B irradiation demonstrated that whereas phosphoramidon-sensitive elastase activity was significantly enhanced in the ultraviolet B-exposed skin, there was no significant increase in that activity in the ultraviolet B-exposed, N-phenetylphosphonyl-leucyl-tryptophane-treated skin. These findings suggest that skin fibroblast elastase plays an essential part in the degeneration and/or tortuosity of elastic fibers induced by cumulative ultraviolet B irradiation.
我们之前报道过，长期紫外线B照射后皮肤中皱纹的形成伴随着皮肤弹性的降低以及真皮中弹性纤维的卷曲。我们进一步表明，用视黄酸治疗可以修复皱纹，并且这与受损弹性纤维修复导致的皮肤弹性恢复同时发生。这些研究表明，降低真皮弹性纤维的曲折度是抑制或修复皱纹形成的一个重要因素。因此，确定体内弹性蛋白酶活性的抑制是否会预防真皮弹性纤维的损伤并可能消除与皮肤弹性丧失相关的皱纹形成特别有意义。因为在非炎症条件下皮肤中的主要弹性蛋白酶是皮肤成纤维细胞弹性蛋白酶，我们使用该酶的特异性抑制剂来评估其在皱纹形成中的生物学作用。将Sprague-Dawley大鼠的后肢皮肤每周用亚红斑剂量的紫外线B照射三次，持续6周。在此期间，每周局部应用0.1 - 10.0 mM的N-苯乙基亚膦酰基-亮氨酰-色氨酸（一种皮肤成纤维细胞弹性蛋白酶抑制剂）五次。以0.1 - 1.0 mM浓度应用N-苯乙基亚膦酰基-亮氨酰-色氨酸以浓度依赖性方式消除了皱纹形成，在1.0 mM时抑制作用达到峰值。这种抑制伴随着真皮弹性纤维持续的低曲折度和皮肤弹性的维持。紫外线B照射六周后弹性蛋白酶活性的测量表明，虽然在紫外线B照射的皮肤中对磷酰胺敏感的弹性蛋白酶活性显著增强，但在紫外线B照射并用N-苯乙基亚膦酰基-亮氨酰-色氨酸处理的皮肤中该活性没有显著增加。这些发现表明，皮肤成纤维细胞弹性蛋白酶在累积紫外线B照射诱导的弹性纤维变性和/或曲折中起重要作用。
