Fritsche A, Mathis G A, Althaus F R
Institut für Pharmakologie und Biochemie der Veterinärmedizinischen Fakultät, Universität Zürich.
Schweiz Arch Tierheilkd. 1991;133(6):277-83.
Biotin deficiency in animals causes pathological changes of the skin and its appendages including, for example, exfoliative dermatitis, depigmentation, and alopecia. The hooves of biotin-deficient swine are weak, brittle, and often necrotic. These changes disappear after dietary biotin supplementation. Biotin supplementation also noticeably improves the hoof quality of horses, cattle and swine having no apparent biotin deficiency. In order to elucidate the molecular basis of these effects, the influence of biotin on cytokeratin expression in a keratinocyte cell line (Ha-CaT) was investigated using electrophoretic and immunological techniques. Pharmacological biotin concentrations of 1 microM, and 100 microM in the culture medium caused a specific increase in cytokeratins, which are normally induced upon terminal differentiation of epidermal cells in vivo. The expression of cytokeratins occurring in stratified epithelia independent of differentiation were not affected. These findings show that biotin directly stimulates the differentiation of epidermal cells. Such a molecular mechanism revealed in cell culture could provide an explanation for the therapeutic effects of pharmacological doses of biotin on hoof quality in farm animals.
动物体内生物素缺乏会导致皮肤及其附属器出现病理变化，例如剥脱性皮炎、色素脱失和脱发。生物素缺乏的猪的蹄子脆弱、易碎，且常出现坏死。补充饮食中的生物素后，这些变化会消失。补充生物素还能显著改善没有明显生物素缺乏的马、牛和猪的蹄质量。为了阐明这些作用的分子基础，利用电泳和免疫技术研究了生物素对角质形成细胞系（Ha-CaT）中细胞角蛋白表达的影响。培养基中1微摩尔和100微摩尔的药理生物素浓度导致细胞角蛋白特异性增加，这些细胞角蛋白通常在体内表皮细胞终末分化时被诱导产生。分层上皮中出现的与分化无关的细胞角蛋白表达不受影响。这些发现表明，生物素直接刺激表皮细胞的分化。在细胞培养中揭示的这种分子机制可以解释药理剂量的生物素对农场动物蹄质量的治疗作用。
