King I A, O'Brien T J, Buxton R S
Division of Eukaryotic Molecular Genetics, National Institute for Medical Research, London, U.K.
J Invest Dermatol. 1996 Oct;107(4):531-8. doi: 10.1111/1523-1747.ep12582790.
Desmosomal junctions contain two classes of desmosomal cadherin, the desmocollins and the desmogleins, each of which occurs as three distinct isoforms. To investigate the role of the "skin-type" desmosomal cadherins (desmocollin 1 and desmoglein 1) in the formation of keratinized epithelial structures, we have now cloned full-length mouse desmocollin 1 complementary deoxyribonucleic acid and examined the expression of desmocollin 1 and desmoglein 1 and messages during murine embryonic development by in situ hybridization. In the general body epidermis, desmocollin 1 and desmoglein 1 transcripts both showed considerable upregulation at 15.5 d, which is after the onset of stratification and before the start of keratinization. Before this the epidermis expressed low levels of desmocollin 1 message, although the desmoglein 1 signal was always stronger and more extensive. In the tongue, expression of desmocollin 1 message occurred several days after desmoglein 1 and coincided with the formation of the keratinizing filiform papillae. Desmoglein 1 message was also detected in epithelial tissues in which desmocollin 1 was absent, suggesting that expression of the two "skin-type" desmosomal cadherins was not tightly coupled during embryonic development. Human desmocollin 1 monoclonal antibodies that cross-reacted with mouse skin and tongue indicated that desmocollin 1 protein was first expressed in those outermost epithelial cells destined to form the keratinized layers of the stratum corneum or the papillae. The results suggest that expression of desmocollin 1 is closely associated with the keratinization of epithelial tissues during mouse development.
桥粒连接包含两类桥粒钙黏蛋白，即桥粒芯胶蛋白和桥粒芯糖蛋白，每一类都有三种不同的亚型。为了研究“皮肤型”桥粒钙黏蛋白（桥粒芯胶蛋白1和桥粒芯糖蛋白1）在角质化上皮结构形成中的作用，我们现已克隆出全长小鼠桥粒芯胶蛋白1互补脱氧核糖核酸，并通过原位杂交检测了小鼠胚胎发育过程中桥粒芯胶蛋白1和桥粒芯糖蛋白1及其信使核糖核酸的表达情况。在全身表皮中，桥粒芯胶蛋白1和桥粒芯糖蛋白1的转录本在胚胎发育第15.5天时均显著上调，此时分层已经开始且角质化尚未开始。在此之前，表皮中桥粒芯胶蛋白1信使核糖核酸的表达水平较低，尽管桥粒芯糖蛋白1的信号总是更强且分布更广。在舌部，桥粒芯胶蛋白1信使核糖核酸的表达比桥粒芯糖蛋白1晚几天出现，且与角质化丝状乳头的形成同时发生。在缺乏桥粒芯胶蛋白1的上皮组织中也检测到了桥粒芯糖蛋白1信使核糖核酸，这表明在胚胎发育过程中这两种“皮肤型”桥粒钙黏蛋白的表达并非紧密相关。与小鼠皮肤和舌部发生交叉反应的人桥粒芯胶蛋白1单克隆抗体表明，桥粒芯胶蛋白1蛋白首先在那些注定要形成角质层或乳头角质化层的最外层上皮细胞中表达。结果表明，在小鼠发育过程中，桥粒芯胶蛋白1的表达与上皮组织的角质化密切相关。
