Busch C, Siegenthaler G, Vahlquist A, Nordlinder H, Sundelin J, Saksena P, Eriksson U
Department of Pathology, University Hospital, Uppsala, Sweden.
J Invest Dermatol. 1992 Dec;99(6):795-802. doi: 10.1111/1523-1747.ep12614757.
Retinoids have important roles in growth and differentiation of epidermal cells. We have analyzed the expression of two intracellular retinoid-binding proteins, the cellular retinol-binding protein type I and the cellular retinoic acid-binding protein type I, during normal and abnormal epidermal differentiation. Both proteins were found to be expressed in normal epidermis with increasing expression from basal layer towards superficial layers. In psoriatic lesions, a hyperproliferative condition of the skin, the epidermal expression of cellular retinol-binding protein I was induced, whereas expression of cellular retinoic acid-binding protein I was sharply down-regulated. This and other features of psoriatic lesions indicate that down-regulation of cellular retinoic acid-binding protein I expression might cause aberrant retinoid-regulated gene expression in skin. In basal and squamous cell carcinomas, cellular retinoic acid-binding protein I expression was down-regulated, whereas cellular retinol-binding protein I was expressed. Apart from epidermal cells, a mesenchymal, dendritic cell-type, strongly expressing cellular retinoic acid-binding protein I, was identified in the dermis. In several hyperproliferative conditions of the skin, including psoriasis, and squamous and basal cell carcinomas, this cell type was abundant. These results have implications for the role of retinoids in normal and abnormal epidermal differentiation and suggest that part of the phenotype of psoriasis is due to inappropriate metabolism of retinoic acid in skin.
维甲酸在表皮细胞的生长和分化中起着重要作用。我们分析了两种细胞内维甲酸结合蛋白，即I型细胞视黄醇结合蛋白和I型细胞视黄酸结合蛋白，在正常和异常表皮分化过程中的表达情况。发现这两种蛋白在正常表皮中均有表达，且从基底层到表层表达逐渐增加。在银屑病皮损中，一种皮肤增殖过度的情况，I型细胞视黄醇结合蛋白的表皮表达被诱导，而I型细胞视黄酸结合蛋白的表达则急剧下调。银屑病皮损的这一特征及其他特征表明，I型细胞视黄酸结合蛋白表达的下调可能导致皮肤中维甲酸调节的基因表达异常。在基底细胞癌和鳞状细胞癌中，I型细胞视黄酸结合蛋白的表达下调，而I型细胞视黄醇结合蛋白有表达。除了表皮细胞外，在真皮中还鉴定出一种间充质树突状细胞类型，其强烈表达I型细胞视黄酸结合蛋白。在包括银屑病、鳞状细胞癌和基底细胞癌在内的几种皮肤增殖过度的情况下，这种细胞类型数量丰富。这些结果对维甲酸在正常和异常表皮分化中的作用具有启示意义，并表明银屑病的部分表型是由于皮肤中视黄酸代谢不当所致。
