Thesleff I, Vaahtokari A, Partanen A M
Department of Pedodontics and Orthodontics, University of Helsinki, Finland.
Int J Dev Biol. 1995 Feb;39(1):35-50.
Vertebrate organs develop from epithelial and mesenchymal tissues, and during their early development they share common morphological features. These include condensation of the mesenchymal cells and thickening, folding or branching of epithelial sheets. Sequential and reciprocal interactions between the epithelial and mesenchymal tissues play central roles in regulation of the morphogenesis of all organs. During recent years increasing amounts of molecular data have accumulated from studies describing developmental changes in expression patterns of molecules, as well as from functional in vitro studies and from the generation of transgenic mice. In this review article, we discuss common features in the molecular regulation that appear to be shared by the developing tooth and other organs. Several growth factors have been shown to act as inductive signals mediating epithelial-mesenchymal interactions in different organs. The early signals are proposed to regulate the expression of master regulatory genes, such as transcription factors. In early tooth germ, bone morphogenetic proteins BMP-2 and BMP-4 regulate expression of the homeobox containing genes Msx-1 and Msx-2. These may specify early patterning of organs through regulation of molecules at the cell surface and the extracellular matrix, such as syndecan-1 and tenascin. Changes in cell adhesion and matrix remodelling, particularly in the organ-specific mesenchyme and in basement membrane contribute to formation of mesenchymal cell condensations and to epithelial morphogenesis. Several growth factors and their receptors, particularly in the TGF beta-, FGF- and EGF- families, have been implicated in formation of mesenchymal condensates and in epithelial morphogenesis of many organs, including the tooth. It is apparent that molecules which regulate morphogenesis in different organs are potential candidate genes for congenital malformation syndromes in which several organs are affected.
脊椎动物的器官由上皮组织和间充质组织发育而来，在其早期发育过程中，它们具有共同的形态学特征。这些特征包括间充质细胞的凝聚以及上皮细胞层的增厚、折叠或分支。上皮组织和间充质组织之间的顺序性和相互作用在所有器官形态发生的调节中起着核心作用。近年来，越来越多的分子数据积累自描述分子表达模式发育变化的研究，以及体外功能研究和转基因小鼠的产生。在这篇综述文章中，我们讨论了发育中的牙齿和其他器官似乎共有的分子调节共同特征。几种生长因子已被证明作为诱导信号介导不同器官中的上皮 - 间充质相互作用。早期信号被认为调节主控调节基因的表达，如转录因子。在早期牙胚中，骨形态发生蛋白BMP - 2和BMP - 4调节含同源框基因Msx - 1和Msx - 2的表达。这些基因可能通过调节细胞表面和细胞外基质中的分子，如syndecan - 1和腱生蛋白，来指定器官的早期模式。细胞黏附的变化和基质重塑，特别是在器官特异性间充质和基底膜中的变化，有助于间充质细胞凝聚的形成和上皮形态发生。几种生长因子及其受体，特别是TGFβ、FGF和EGF家族中的成员，已被证明与包括牙齿在内的许多器官的间充质凝聚形成和上皮形态发生有关。显然，调节不同器官形态发生的分子是多种器官受影响的先天性畸形综合征的潜在候选基因。
