Associations between transforming growth factor beta 1 RNA expression and epithelial-mesenchymal interactions during tooth morphogenesis.
Associations between transforming growth factor beta 1 RNA expression and epithelial-mesenchymal interactions during tooth morphogenesis.
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发表时间：
1991-11
期刊：
影响因子：
4.6
通讯作者：
A. Vaahtokari;S. Vainio;I. Thesleff
中科院分区：
文献类型：
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作者：
A. Vaahtokari;S. Vainio;I. Thesleff
我们利用原位杂交和实验性组织重组研究了转化生长因子β -1 (tgf - β 1) RNA在小鼠牙齿发育过程中的表达。序列切片分析显示，胚期（13天）牙上皮中出现tgf - β 1 RNA的局部表达。在过渡到牙帽期之前，上皮芽中tgf - β 1 RNA的表达迅速增加，并扩展到牙凝聚间质。在帽期（胚胎14天和15天），在形态活跃的牙上皮颈袢中有tgf - β 1 RNA的强烈表达。在胚胎早期（16天和17天），tgf - β 1 RNA在内釉质上皮中表达，随后几乎消失（18天胚胎）。出生后，tgf - β 1转录物在这些细胞分化成成釉细胞时短暂出现（1天小鼠）。这些转录本在成釉细胞分泌后（4 d小鼠）丢失，但在无釉质区成釉细胞中继续表达。在成釉细胞分化时，在上皮层中间细胞中也检测到tgf - β 1 RNA的瞬时表达。在间充质中，tgf - β 1 RNA在钟期未被检测到，直到它出现在分化的成牙细胞（18天胚胎）中。分泌性成牙细胞在包括门牙根成牙细胞在内的所有研究阶段都继续表达tgf - β 1 RNA。对溴脱氧尿苷（BrdU）掺入分布的分析表明，tgf - β 1 RNA的表达与牙齿芽和牙盖阶段的细胞增殖有明显的相关性，而在牙齿发育的后期没有相关性。芽期（13天胚胎）牙组织和非牙组织的组织重组实验表明，牙上皮与牙间质一起培养时表达tgf - β 1 RNA。当牙上皮与非牙颌间质结合时，tgf - β 1转录本不表达。然而，tgf - β 1 RNA在牙间质培养的口腔上皮中表达，而在正常发育的口腔上皮中未见tgf - β 1转录本的表达。因此，tgf - β 1 RNA的表达似乎受到上皮-间质相互作用的调节。
We have studied the expression of transforming growth factor beta-1 (TGF-beta 1) RNA during mouse tooth development, using in situ hybridization and experimental tissue recombinations. Analysis of the serial sections revealed the appearance of local expression of TGF-beta 1 RNA in the dental epithelium at bud-staged teeth (13-day embryos). Just before transition to the cap stage, TGF-beta 1 RNA expression rapidly increased in the epithelial bud, and it also extended to the condensed dental mesenchyme. At cap stage (14- and 15-day embryos), there was an intense expression of TGF-beta 1 RNA in the morphologically active cervical loops of the dental epithelium. During early bell stage (16- and 17-day embryos), TGF-beta 1 RNA expression was detected in the inner enamel epithelium where it subsequently almost disappeared (18-day embryos). After birth TGF-beta 1 transcripts transiently appeared in these cells when they were differentiating into ameloblasts (1-day mice). The transcripts were lost from the ameloblasts when they became secretory (4-day mice), but the expression continued in ameloblasts in enamel-free areas. Transient expression of TGF-beta 1 RNA was also detected in epithelial stratum intermedium cells at the time of ameloblast differentiation. In the mesenchyme, TGF-beta 1 RNA was not detected during bell stage until it appeared in differentiated odontoblasts (18-day embryos). The secretory odontoblasts continued to express TGF-beta 1 RNA at all stages studied including the odontoblasts of incisor roots. Analysis of the distribution of bromodeoxyuridine (BrdU) incorporation indicated apparent correlations between TGF-beta 1 RNA expression and cell proliferation at the bud and cap stages but not at later stages of tooth development. Tissue recombination experiments of bud-staged (13-day embryos) dental and non-dental tissues showed that tooth epithelium, when cultured together with tooth mesenchyme, expressed TGF-beta 1 RNA. When the tooth epithelium was combined with non-dental jaw mesenchyme, TGF-beta 1 transcripts were not expressed. However, TGF-beta 1 RNA expression was seen in oral epithelium cultured with dental mesenchyme, while no expression of TGF-beta 1 transcripts was seen in the oral epithelium during normal development. Thus, TGF-beta 1 RNA expression seems to be regulated by epithelial-mesenchymal interactions.