Schallreuter K U, Witkop C J
Department of Dermatology, University of Hamburg, Federal Republic of Germany.
J Invest Dermatol. 1988 Mar;90(3):372-7. doi: 10.1111/1523-1747.ep12456424.
Recent studies indicate that membrane-associated thioredoxin reductase (TR) is a possible regulator of melanin biosynthesis via the inhibition of tyrosinase by reduced thioredoxin. In normal individuals, the levels of TR activity in skin correlate linearly to the Fitzpatrick classification of skin type, being lowest in type I skin and highest in skin type VI. In this study, TR was measured in 3-mm skin biopsies in Hermansky-Pudlak syndrome (HPS) patients and their relatives. Forty-five individuals from seven Puerto Rican kindreds were tested, including 12 homozygotes, nine obligate heterozygotes, and 24 unclassified individuals. In addition, seven separate nonkindred HPS patients were tested. With one exception, TR activity was markedly decreased in 18 homozygotes. TR activity was decreased in eight obligate heterozygotes and in 12 unclassified kindred members, whereas 10 subjects had normal TR activity when compared to the expected activity of their skin type. Four individuals were excluded from the analysis because of inadequate controls for their age group or immunosuppressive treatment for kidney transplant. The results indicate that decreased TR activity assayed in 3-mm skin punch biopsies is a useful method for detecting carriers of the HPS gene.
近期研究表明，膜相关硫氧还蛋白还原酶（TR）可能是黑色素生物合成的调节因子，它通过还原型硫氧还蛋白抑制酪氨酸酶来实现这一调节作用。在正常个体中，皮肤中TR活性水平与菲茨帕特里克皮肤分型呈线性相关，在I型皮肤中最低，在VI型皮肤中最高。在本研究中，对赫尔曼斯基-普德拉克综合征（HPS）患者及其亲属的3毫米皮肤活检样本进行了TR检测。对来自7个波多黎各家族的45人进行了检测，包括12名纯合子、9名肯定杂合子和24名未分型个体。此外，还检测了7名无亲缘关系的独立HPS患者。除1例例外，18名纯合子的TR活性显著降低。8名肯定杂合子和12名未分型家族成员的TR活性降低，而与他们皮肤类型的预期活性相比，有10名受试者的TR活性正常。有4人因年龄组对照不足或接受肾移植免疫抑制治疗而被排除在分析之外。结果表明，在3毫米皮肤打孔活检中检测到的TR活性降低是检测HPS基因携带者的一种有用方法。
