Xu L X, Kukita T, Yu H, Nakano Y, Koga T
Department of Preventive Dentistry, Faculty of Dentistry, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Calcif Tissue Int. 1998 Oct;63(4):351-6. doi: 10.1007/s002239900539.
Interleukin-1 (IL-1) can exert its pleiotropic effects on nearly every tissue by binding to its cognate receptor. Two types of IL-1 receptors have been identified. A large number of cell types have been shown to possess IL-1 receptors in vitro and in vivo, but few studies have addressed the question of expression in dental tissues in vivo. Using in situ hybridization in normal newborn, young and adult mice, we have examined the cellular distribution of both types of IL-1 receptors in dental tissues. In the ameloblast layer of incisors and molars, the mRNA for the type I IL-1 receptor (IL-1RI) and the type II IL-1 receptor (IL-1RII) was detected at the presecretory stage. The expression level markedly increased and remained during amelogenesis at the secretory stage. At the maturation stage, however, the transcripts for both IL-1RI and -II mRNA disappeared. Expression of IL-1RI and -II mRNA was also observed in odontoblasts after crown morphogenesis had been completed, and continued in these cells during dentinogenesis. No transcripts were detected in stratum intermedium cells and other cells in dental follicle, stellate reticulum, dental papilla, or pulp. Additionally, both types of IL-1R mRNA were also detected in osteoclasts on surfaces of alveolar bone. These results demonstrated for the first time that enamel-secreting ameloblasts and dentine-secreting odontoblasts express IL-1RI and -II mRNA, suggesting that IL-1 plays a regulatory role in the function of ameloblasts and odontoblasts during tooth development of mice.
白细胞介素-1（IL-1）可通过与其同源受体结合，对几乎每个组织发挥其多效性作用。已鉴定出两种类型的IL-1受体。大量细胞类型已在体外和体内被证明具有IL-1受体，但很少有研究探讨其在体内牙组织中的表达问题。我们利用原位杂交技术，对正常新生、幼年和成年小鼠牙组织中两种类型IL-1受体的细胞分布进行了研究。在切牙和磨牙的成釉细胞层，在分泌前期可检测到I型IL-1受体（IL-1RI）和II型IL-1受体（IL-1RII）的mRNA。在分泌期的釉质形成过程中，表达水平显著升高并持续存在。然而，在成熟阶段，IL-1RI和-II mRNA的转录本均消失。在牙冠形态发生完成后的成牙本质细胞中也观察到IL-1RI和-II mRNA的表达，并在牙本质形成过程中在这些细胞中持续存在。在中间层细胞以及牙囊、星网状层、牙乳头或牙髓中的其他细胞中未检测到转录本。此外，在牙槽骨表面的破骨细胞中也检测到了两种类型的IL-1R mRNA。这些结果首次证明，分泌釉质的成釉细胞和分泌牙本质的成牙本质细胞表达IL-1RI和-II mRNA，表明IL-1在小鼠牙齿发育过程中对成釉细胞和成牙本质细胞的功能发挥调节作用。
