Miyake K, Ciletti N, Liao S, Rosenfield R L
Department of Pediatrics, Ben May Institute, University of Chicago, Pritzker School of Medicine, Illinois.
J Invest Dermatol. 1994 Nov;103(5):721-5. doi: 10.1111/1523-1747.ep12398601.
As in other sebaceous glands, preputial gland sebocytes are stimulated to proliferate and produce lipid by androgen. As a necessary step in understanding the role of androgen in sebaceous gland growth and development, we have undertaken studies to determine the relationship between androgen receptor gene expression and sebocyte differentiation. Sebocytes throughout the preputial gland, with the exception of some basal sebocytes, stain intensely for androgen receptor. Quantitative assessment of androgen receptor mRNA by RNase protection assay confirms that androgen receptor mRNA abundance is similar in sebaceous and prostate epithelial cells, but is tenfold less in epidermal cells. When sebocytes were separated according to their state of differentiation by gradient density centrifugation, sebocytes in the 1.080 density fraction contrasted with the more buoyant fractions in that they immunostained weakly for androgen receptors. The 1.080 fraction consists of approximately 50% immature (undifferentiated and early differentiated) sebocytes, whereas more mature sebocytes predominate in the other fractions. Androgen receptor mRNA quantity was found by RNase protection assay to be half as great in the 1.080 density fraction as in the fractions in which more mature sebocytes predominate. In primary monolayer culture androgen receptor mRNA content was significantly higher in sebaceous epithelial cells than in epidermal cells and similar to that in the 1.080 fraction of freshly dispersed sebocytes. These results suggest that there is little if any androgen receptor gene expression in undifferentiated preputial sebocytes and that androgen receptor gene expression increases as sebocytes begin to differentiate. Because androgen receptor expression seems to approach its maximum as sebocytes attain mid-differentiation, the stage at which sebocytes switch from a proliferative mode to commence their specialized holocrine function, androgen is postulated to play a direct role in regulating these aspects of sebocyte development.
与其他皮脂腺一样，雄激素刺激包皮腺的皮脂腺细胞增殖并产生脂质。作为了解雄激素在皮脂腺生长和发育中作用的必要步骤，我们开展了研究以确定雄激素受体基因表达与皮脂腺细胞分化之间的关系。除了一些基底皮脂腺细胞外，整个包皮腺中的皮脂腺细胞雄激素受体染色均呈强阳性。通过核糖核酸酶保护试验对雄激素受体mRNA进行定量评估证实，皮脂腺和前列腺上皮细胞中雄激素受体mRNA丰度相似，但表皮细胞中的丰度要低10倍。当通过梯度密度离心根据皮脂腺细胞的分化状态进行分离时，密度为1.080的部分中的皮脂腺细胞与浮力更大的部分形成对比，前者对雄激素受体的免疫染色较弱。密度为1.080的部分约由50%的未成熟（未分化和早期分化）皮脂腺细胞组成，而其他部分中成熟皮脂腺细胞占主导。通过核糖核酸酶保护试验发现，密度为1.080的部分中雄激素受体mRNA的量是成熟皮脂腺细胞占主导部分的一半。在原代单层培养中，皮脂腺上皮细胞中雄激素受体mRNA含量显著高于表皮细胞，且与新鲜分散的皮脂腺细胞密度为1.080的部分中的含量相似。这些结果表明，未分化的包皮皮脂腺细胞中几乎没有雄激素受体基因表达，并且随着皮脂腺细胞开始分化，雄激素受体基因表达增加。由于当皮脂腺细胞达到分化中期时雄激素受体表达似乎接近最大值，而此时皮脂腺细胞从增殖模式转变为开始其特有的全质分泌功能，因此推测雄激素在调节皮脂腺细胞发育的这些方面起直接作用。
