Sequential expression of an amelin gene in mesenchymal and epithelial cells during odontogenesis in rats
Sequential expression of an amelin gene in mesenchymal and epithelial cells during odontogenesis in rats
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DOI：
10.1111/j.1600-0722.1998.tb02193.x
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发表时间：
1998-01-01
影响因子：
1.9
通讯作者：
Slaby, I
中科院分区：
文献类型：
--
作者：
Fong, CD;Cerny, R;Slaby, I
最近已经描述了编码釉基质蛋白amelin-1、amelin-2和成釉蛋白的新型mRNA异构体。我们应用详细的免疫组织化学以及非放射性原位杂交分析，以遵循amelin-1在发育中的大鼠切牙和磨牙的表达。我们构建了一个表达载体，在大肠杆菌中过量生产重组amelin并制备了抗体。除了先前报道的成釉细胞中釉蛋白mRNA的表达模式，釉蛋白的信息也检测到牙髓间充质细胞，包括前成牙本质细胞和年轻的成牙本质细胞。这些细胞中的信号持续到套牙本质沉积变得明显。amelin-1在前成牙本质细胞和成釉细胞中的免疫定位基本上遵循mRNA表达的模式。最强烈的染色被发现在釉基质分泌成釉细胞附近。局灶性积累的免疫反应物质被发现在牙本质釉质交界处的成熟阶段。此外，使用5 '-RACE（cDNA末端快速扩增），我们可以确认只有amelin-1和成釉蛋白的信息在总RNA池从大鼠磨牙，并得出结论，amelin-2是一个截短形式的成釉蛋白。釉蛋白在间充质和上皮细胞中的顺序表达表明它在早期牙齿发育过程中的细胞分化中起作用。
Novel mRNA isoforms encoding the enamel matrix proteins amelin-1, amelin-2 and ameloblastin have been recently described. We have applied detailed immunohistochemical as well as non-radioactive in situ hybridization analyses to follow amelin-1 expression in developing rat incisors and molars. We constructed an expression vector, overproduced recombinant amelin in Escherichia coli and prepared an antibody. In addition to the previously reported amelin mRNA expression patterns in ameloblasts, the amelin message was also detected in pulpal mesenchymal cells including preodontoblasts and young odontoblasts. The signal in these cells persisted until deposition of mantle dentin became evident. The immunolocalization of amelin-1 in preodontoblasts and ameloblasts essentially followed the pattern of mRNA expression. The most intense staining was found in the enamel matrix adjacent to secretory ameloblasts. Focal accumulations of immunoreactive material were found at the dentinoenamel junction during the maturation stage. Also, using 5'-RACE (Rapid Amplification of cDNA Ends) we could confirm only amelin-1 and ameloblastin messages in the total RNA pool from rat molars and conclude that amelin-2 is a truncated form of ameloblastin. The sequential expression of amelin in mesenchymal and epithelial cells suggests it plays a role in cell differentiation during early tooth development.