Wang W-H, Li L-F, Zhang B-X, Lu X-Y
Department of Dermatology, Peking University Third Hospital, 49 North Garden Road, Haidian District, Beijing 100083, China.
Clin Exp Dermatol. 2004 Jan;29(1):57-61. doi: 10.1111/j.1365-2230.2004.01424.x.
Events that induce expression of the metallothionein (MT) gene, such as injection of cadmium chloride, cold stress or topical application of 1,25-dihydroxyvitamin D3, can deplete the number of ultraviolet (UV) B-induced sunburn cells (SBC) in mouse skin in vivo. MT-null mouse skin explants exhibit reduced tolerance to UVB injury in vitro. However, the in vivo response of MT-null mice to UVB injury has not been investigated. In the present study, we investigated the role of the MT gene on UVB injury in vivo. MT-null mice that are deficient in MT-I and MT-II genes were studied and compared with homozygous wild-type mice. Mouse dorsal skin was irradiated with 0.05, 0.70 and 1.40 J/cm2 UVB. The thickness of the dorsal skin was measured with a spring micrometer before and 24 h after UVB irradiation. In addition, SBC were counted 24 h after UVB irradiation. No significant difference was found in the change of skin thickness between MT-null mice and control mice irradiated with low-dose UVB (0.05 J/cm2) (Student's t-test, t = 1.519, P = 0.167). At higher doses (0.70 and 1.40 J/cm2), the skin of MT-null mice became much thicker than that of control mice (Student's t-test, t = 6.576, P < 0.01 and t = 3.142, P = 0.007, respectively). More SBC were detected in MT-null mice skin irradiated with the highest dose of UVB (1.40 J/cm2) (Student's t-test, t = 4.258, P < 0.01). These results suggest that the MT gene in mice has a photoprotective role in vivo.
诱导金属硫蛋白（MT）基因表达的事件，如注射氯化镉、冷应激或局部应用1,25 - 二羟基维生素D3，可在体内减少小鼠皮肤中紫外线（UV）B诱导的晒伤细胞（SBC）数量。MT基因敲除小鼠的皮肤外植体在体外对UVB损伤的耐受性降低。然而，MT基因敲除小鼠对UVB损伤的体内反应尚未得到研究。在本研究中，我们调查了MT基因在体内UVB损伤中的作用。研究了缺乏MT - I和MT - II基因的MT基因敲除小鼠，并与纯合野生型小鼠进行比较。用0.05、0.70和1.40 J/cm2的UVB照射小鼠背部皮肤。在UVB照射前和照射后24小时用弹簧测微计测量背部皮肤厚度。此外，在UVB照射后24小时对SBC进行计数。在用低剂量UVB（0.05 J/cm2）照射的MT基因敲除小鼠和对照小鼠之间，未发现皮肤厚度变化有显著差异（学生t检验，t = 1.519，P = 0.167）。在较高剂量（0.70和1.40 J/cm2）下，MT基因敲除小鼠的皮肤比对照小鼠厚得多（学生t检验，分别为t = 6.576，P < 0.01和t = 3.142，P = 0.007）。在用最高剂量UVB（1.40 J/cm2）照射的MT基因敲除小鼠皮肤中检测到更多的SBC（学生t检验，t = 4.258，P < 0.01）。这些结果表明，小鼠中的MT基因在体内具有光保护作用。
