Adaptive Calcified Matrix Response of Dental Pulp to Bacterial Invasion Is Associated with Establishment of a Network of Glial Fibrillary Acidic Protein+/Glutamine Synthetase+ Cells
Adaptive Calcified Matrix Response of Dental Pulp to Bacterial Invasion Is Associated with Establishment of a Network of Glial Fibrillary Acidic Protein+/Glutamine Synthetase+ Cells
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DOI：
10.2353/ajpath.2010.100073
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发表时间：
2010-10-01
影响因子：
6
通讯作者：
Hunter, Neil
中科院分区：
文献类型：
--
作者：
Farahani, Ramin M.;Nguyen, Ky-Anh;Hunter, Neil
我们报告的证据，牙髓的解剖和功能的变化，通过牙本质的细菌入侵，平行反应神经嵴衍生的感觉组织报告的有害刺激。制备树脂包埋的龋坏成人磨牙的切片进行免疫组织化学、原位杂交、超微结构分析和显微切割以提取mRNA用于定量分析。在成牙本质细胞邻近的龋齿细菌入侵的前沿，编码牙本质板蛋白的基因的表达水平比健康牙齿的成牙本质细胞高16倍，随着距离该网站的龋损逐渐减少。与此相反，成牙本质细胞的牙本质基质蛋白-1基因表达完全抑制在龋齿相对于健康牙齿。这些基因表达的变化与沉积的反应性牙本质的梯度相关，其显示出高度修饰的结构。在龋坏牙中，表达谷氨酰胺合成酶（GS）的成牙本质细胞间牙本质涎蛋白（+）细胞显示胶质细胞酸性蛋白（GFAP）表达上调。这些细胞延伸出与成牙本质细胞相关的突起。此外，连接蛋白43仅在龋牙中建立了相邻GFAP（+）/GS（+）细胞之间的连接。这些发现表明牙髓对侵蚀性龋的适应性反应，包括与成牙本质细胞间GFAP（+）/GS（+）网络相关的改性钙化牙本质基质的沉积。GFAP（+）/GS（+）细胞网络可能通过谷氨酸的分泌调节成牙本质细胞的反应。(Am J Pathol 2010，177：1901-1914; DOI：10.2353/ajpath.2010.100073）
We report evidence for anatomical and functional changes of dental pulp in response to bacterial invasion through dentin that parallel responses to noxious stimuli reported in neural crest-derived sensory tissues. Sections of resin-embedded carious adult molar teeth were prepared for immunohistochemistry, in situ hybridization, ultrastructural analysis, and microdissection to extract mRNA for quantitative analyses. In odontoblasts adjacent to the leading edge of bacterial invasion in carious teeth, expression levels of the gene encoding dentin slab-protein were 16-fold greater than in odontoblasts of healthy teeth, reducing progressively with distance from this site of the carious lesion. In contrast, gene expression for dentin matrix protein-1 by odontoblasts was completely suppressed in carious teeth relative to healthy teeth. These changes in gene expression were related to a gradient of deposited reactionary dentin that displayed a highly modified structure. In carious teeth, interodontoblastic dentin sialo-protein(+) cells expressing glutamine synthetase (GS) showed up-regulation of glial fibrillary acidic protein (GFAP). These cells extended processes that associated with odontoblasts. Furthermore, connexin 43 established a linkage between adjacent GFAP(+)/GS(+) cells in carious teeth only. These findings indicate an adaptive pulpal response to encroaching caries that includes the deposition of modified, calcified, dentin matrix associated with networks of GFAP(+)/GS(+) interodontoblastic cells. A regulatory role for the networks of GFAP(+)/GS(+) cells is proposed, mediated by the secretion of glutamate to modulate odontoblastic response. (Am J Pathol 2010, 177:1901-1914; DOI: 10.2353/ajpath.2010.100073)