The function of Thymosin beta 10 and 4 in the tooth development

本研究研究了Tb4同源物胸腺素β 10 （Tb10）在小鼠下第一磨牙发育过程中的表达模式和功能。Tb10主要在牙间充质细胞和牙上皮细胞中原位表达，Tb4在牙上皮细胞中表达。Tb10-siRNA在E11.0下颌骨的抑制实验显示，Tb10-siRNA对牙胚的生长有明显的抑制作用。tb10 - sirna处理下颌骨中ki67阳性细胞数量明显减少。tb10 - sirna处理的培养小鼠牙髓和上皮细胞的细胞增殖活性也明显受到抑制。这些结果表明，牙胚发育阻滞可能是由细胞增殖活性降低引起的。Tb10在牙胚发育过程中不同阶段的时空表达模式表明其在牙胚发育过程中具有多种功能。

This study presents the expression pattern and functions of thymosin beta 10 (Tb10), a Tb4 homologue during the development of mouse lower first molars. An in situ signal of Tb10 was detected mainly in dental mesenchymal cells as well as in dental epithelial cells, while Tb4 was expressed in dental epithelial cells. An inhibition assay using Tb10-siRNA in E11.0 mandibles showed significant growth inhibition in the tooth germ. The number of Ki67-positive cells significantly decreased in the Tb10-siRNA-treated mandibles. The cellular proliferative activity was also significantly suppressed in Tb10-siRNA-treated cultured mouse dental pulpal and epithelial cells. These results indicate that developmental arrest of the tooth germ might be caused by a reduction in cell proliferative activity. The stage-specific temporal and spatial expression pattern of Tb10 in the developing tooth germ is indicative of multiple functions in the tooth development.