Spahr Axel, Lyngstadaas Staale P, Slaby Ivan, Pezeshki Gita
Department Of Conservative Dentistry and Periodontology, University of Ulm, Ulm, Germany.
Eur J Oral Sci. 2006 Dec;114(6):504-11. doi: 10.1111/j.1600-0722.2006.00403.x.
Based on previous results showing the expression of ameloblastin (Ambn; amelin) in the formation of mesenchymal dental hard tissues, we investigated its presence during bone development. Immunohistochemistry (IHC), in situ hybridization (ISH), and reverse transcription-polymerase chain reaction (RT-PCR) were used to investigate the expression of ameloblastin protein and mRNA during craniofacial development in rats. Tissue samples were collected on embryonic day 18 and from days 2-28 postnatally. IHC revealed the expression of ameloblastin during bone formation at embryonic and early postnatal stages with different patterns of expression in intramembranous and endochondral ossification. In intramembranous ossification, ameloblastin expression was detected in the superficial layer of the condensed vascularized primitive connective tissue and in the cellular layer covering the surface of the newly formed woven bone. In endochondral ossification, ameloblastin was expressed within the extracellular matrix of the cartilage templates and in the perichondrium. Between days 2 and 28 the expression decreased markedly, concordant with the maturation of the bone, and disappeared after completion of bone remodeling. The results obtained by IHC were confirmed by ISH and RT-PCR, showing the expression of ameloblastin mRNA during craniofacial bone formation. This study indicates the expression of the putative dental protein ameloblastin during craniofacial bone development in rats.
基于先前的研究结果显示成釉蛋白（Ambn；amelin）在间充质牙硬组织形成过程中的表达，我们研究了其在骨骼发育过程中的存在情况。采用免疫组织化学（IHC）、原位杂交（ISH）和逆转录聚合酶链反应（RT-PCR）来研究大鼠颅面发育过程中成釉蛋白的蛋白质和mRNA表达。在胚胎第18天以及出生后第2 - 28天收集组织样本。免疫组织化学显示在胚胎期和出生后早期骨骼形成过程中成釉蛋白有表达，在膜内成骨和软骨内成骨中表达模式不同。在膜内成骨中，在致密血管化原始结缔组织的表层以及覆盖新形成编织骨表面的细胞层中检测到成釉蛋白表达。在软骨内成骨中，成釉蛋白在软骨模板的细胞外基质和软骨膜中表达。在第2天至第28天之间，随着骨骼成熟表达明显下降，并在骨重塑完成后消失。免疫组织化学获得的结果通过原位杂交和逆转录聚合酶链反应得到证实，显示在颅面骨形成过程中有成釉蛋白mRNA的表达。本研究表明在大鼠颅面骨发育过程中假定的牙源性蛋白成釉蛋白有表达。
