融合蛋白PTD-SOD对豚鼠UVB损伤的预防效应

The preventing effects of recombinant protein PTD-SOD on guinea pigs damaged by Ultraviolet B

本研究建立了体外豚鼠皮肤一次性中波紫外(UVB)损伤和多次性UVB损伤模型,以超氧化物歧化酶(SOD)为对照,探讨两种融合了蛋白转导域的超氧化物歧化酶(PTD-SOD)PTD-SOD1和PTD-SOD2对豚鼠UVB损伤的预防效应,动物实验利用数码相机拍摄豚鼠背部相关区域皮肤的颜色变化,再利用PHOTOSHOP软件通过测量a*值,分析产生红斑程度来衡量辐射损伤的程度。结果表明,对于一次性辐射损伤,SOD基本没有预防效果,两种PTD-SOD均有较好的预防效果,PTD-SOD2的预防效果优于PTD-SOD1,两种蛋白的剂量与其保护效果均呈钟形曲线关系。其最佳给药时间均为辐射前0.5 h,使用量为2000 U,超过则保护效果减弱。对于多次性辐射损伤,也是SOD基本没有预防效果,两种PTD-SOD均有较好的预防效果,而PTD-SOD2的预防效果优于PTD-SOD1;皮肤切片结果也表明,两种PTD-SOD都能有效减轻豚鼠皮肤表皮层因多次性UVB辐射引起的肿胀。

The oxidized damage models of the skins of guinea pigs caused by single dose and repeating UVB radiation were established. The preventive effects of recombinant protein PTD-SOD1 and PTD-SOD2 compared with wide-type SOD on the oxidized damage of ultraviolet B radiation were then studied. The color change of the skins of the back of guinea pigs were recorded with a digital camera and analyzed with Photoshop software. The degree of erythema was evaluated by measuring the a^＊ value which indicated the amount of redness in the skin. An increment of a^＊ values indicates the development of erythema. It has been proved that compared with wide-type SOD, both PTD-SOD1 and PTD-SOD2 can well prevent the damage of the skin of guinea pigs by single dose UVB radiation and PTD-SOD2 is the better one. The bell-shaped dose-response curves can be seen when the oxidized damage of guinea pigs is caused by single dose ultraviolet B radiation and protected by exogenous PTD-SOD. The two PTD-SOD proteins are effective in prevention of cutaneous damage caused by UVB irradiation when the guinea pigs are administered 2000 U proteins 0.5 h before irradiation, beyond which protection is lost and injury is even exacerbated. The PTD-SOD proteins have been proved to have a far better protective effect than that of wild-type SOD on repeating ultraviolet B radiation too. The results are confirmed by the histomophological analysis of the guinea pigs skin.