Proteomic analysis of dentin-enamel junction and adjacent protein-containing enamel matrix layer of healthy human molar teeth
Proteomic analysis of dentin-enamel junction and adjacent protein-containing enamel matrix layer of healthy human molar teeth
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DOI：
10.1111/eos.12594
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发表时间：
2019-04-01
影响因子：
1.9
通讯作者：
Miksik, Ivan
中科院分区：
文献类型：
--
作者：
Jagr, Michal;Ergang, Peter;Miksik, Ivan
牙本质-牙釉质交界处是两种不同矿化结构--牙釉质和牙本质--的交界处。富含蛋白质的DEJ与成熟牙齿的内釉质区一起，显示出比大块相牙釉质更高的断裂韧性和裂纹扩展阻力。然而，由于缺乏DEJ和邻近的牙釉质有机基质(EOM)的组成信息，对这一行为的解释一直受到阻碍。我们研究了健康人磨牙DEJ和EOM的蛋白质组，并将它们与同一牙齿的牙本质和釉质蛋白质组进行了比较。用激光捕获显微切割技术从牙齿切片上切下这些组织，提取蛋白质，用胰酶裂解，然后用液相色谱-串联质谱仪分析这些组织的蛋白质组图谱。本研究鉴定了DEJ和EOM中的46种蛋白质。已鉴定的蛋白质具有多种功能，包括与钙离子结合、形成细胞外基质、形成细胞骨架、结合细胞骨架蛋白、细胞黏附和运输。胶原蛋白是最主要的蛋白质。组织特异性蛋白，如成釉蛋白和成釉蛋白也被检测到。我们的发现揭示了DEJ和EOM的蛋白质组学的新见解，这是一种显然难以分析的高度矿化的组织。
The dentin-enamel junction (DEJ) is the border where two different mineralized structures - enamel and dentin - meet. The protein-rich DEJ, together with the inner enamel region of mature teeth, is known to exhibit higher fracture toughness and crack growth resistance than bulk phase enamel. However, an explanation for this behavior has been hampered by the lack of compositional information for the DEJ and the adjacent enamel organic matrix (EOM). We studied proteomes of the DEJ and EOM of healthy human molars and compared them with dentin and enamel proteomes from the same teeth. These tissues were cut out of tooth sections by laser capture microdissection, proteins were extracted and cleaved by trypsin, then processed by liquid chromatography coupled to tandem mass spectrometry to analyze the proteome profiles of these tissues. This study identified 46 proteins in DEJ and EOM. The proteins identified have a variety of functions, including calcium ion-binding, formation of extracellular matrix, formation of cytoskeleton, cytoskeletal protein binding, cell adhesion, and transport. Collagens were identified as the most dominant proteins. Tissue-specific proteins, such as ameloblastin and amelogenin, were also detected. Our findings reveal new insight into proteomics of DEJ and EOM, highly mineralized tissues that are obviously difficult to analyze.