Keratins as components of the enamel organic matrix.
Keratins as components of the enamel organic matrix.
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DOI：
10.1016/j.matbio.2015.12.007
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发表时间：
2016-05
期刊：
影响因子：
--
通讯作者：
Morasso MI
中科院分区：
文献类型：
--
作者：
Duverger O;Beniash E;Morasso MI
牙釉质是人体内最坚硬的组织，虽然它一开始是富含蛋白质的组织，但当牙齿在口腔中长出时，只剩下一小部分蛋白质。虽然这种有机基质占牙釉质重量的比例不到1%，但它在提高韧性和抗化学攻击的弹性方面起着至关重要的作用。尽管对牙釉质基质的第一次研究始于19世纪，但对其确切的组成和功能机制仍然知之甚少。有人提出角蛋白或类似角蛋白的原始上皮成分存在于成熟的牙釉质中，但由于其有机基质的极端不溶性，角蛋白的存在从未得到明确的证实。我们最近在成釉细胞（牙釉质分泌细胞）中发现了一些毛发角蛋白的表达，并证明了它们与成熟牙釉质的结合。上皮性毛发角蛋白KRT75的突变会导致一种叫做假性毛囊炎的皮肤病。这种突变的携带者具有改变的牙釉质结构和机械性能。重要的是，这些人的龋齿患病率要高得多。据我们所知，这是第一个显示基因蛋白质编码区突变与龋齿发病率增加之间直接联系的研究。在本文中，我们提出的证据，在过去的150年中积累的牙釉质角蛋白样物质的概述。此外，我们提出了KTR75在牙釉质中的潜在作用机制，并强调了KRT75突变与龋齿之间联系的临床意义。最后，我们讨论了角蛋白在牙釉质修复中的潜在应用。
Dental enamel is a hardest tissue in the human body, and although it starts as a tissue rich in proteins, by the time of eruption of the tooth in the oral cavity only a small fraction of the protein remains. While this organic matrix of enamel represents less than 1% by weight it plays essential roles in improving both toughness and resilience to chemical attacks. Despite the fact that the first studies of the enamel matrix began in the 19th century its exact composition and mechanisms of its function remain poorly understood. It was proposed that keratin or a keratin-like primitive epithelial component exists in mature enamel, however due to the extreme insolubility of its organic matrix the presence of keratins there was never clearly established. We have recently identified expression of a number of hair keratins in ameloblasts, the enamel secreting cells, and demonstrated their incorporation into mature enamel. Mutation in epithelial hair keratin KRT75 leads to a skin condition called pseudofollicularis barbae. Carriers of this mutation have an altered enamel structure and mechanical properties. Importantly, these individuals have a much higher prevalence of caries. To the best of our knowledge, this is the first study showing a direct link between a mutation in a protein-coding region of a gene and increased caries rates. In this paper we present an overview of the evidence of keratin-like material in enamel that has accumulated over the last 150 years. Furthermore, we propose potential mechanisms of action of KTR75 in enamel and highlight the clinical implications of the link between mutations in KRT75 and caries. Finally, we discuss the potential use of keratins for enamel repair.