Morimoto Y, Kawahara K-I, Tancharoen S, Kikuchi K, Matsuyama T, Hashiguchi T, Izumi Y, Maruyama I
Department of Periodontology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan.
J Periodontal Res. 2008 Feb;43(1):76-83. doi: 10.1111/j.1600-0765.2007.00996.x. Epub 2007 Dec 6.
High-mobility-group box 1 functions as a late-phase inflammatory mediator. It can be released extracellularly by macrophages and necrotic cells through lipopolysaccharide and tumor necrosis factor-alpha. The objective of this study was to clarify the source of high-mobility-group box 1 in chronic periodontitis tissues and tumor necrosis factor-alpha-stimulated gingival epithelial cells, and subsequently elucidate its inducible inflammatory pathway.
Chronic periodontitis and healthy gingival sections were stained for high-mobility-group box 1 by immunohistochemistry and immunofluorescence. The amounts of high-mobility-group box 1 released into the gingival crevicular fluid and supernatants from gingival epithelial cells stimulated by tumor necrosis factor-alpha were examined by western blot. The phosphorylation of mitogen-activated protein kinases (MAPKs) in gingival epithelial cells was also examined.
High-mobility-group box 1 was detected in the cytoplasm and nucleus of gingival epithelial cells with periodontitis. Western blotting revealed a significant increase in high-mobility-group box 1 expression in the gingival crevicular fluid from periodontitis patients. High-mobility-group box 1 production in gingival epithelial cells was increased following stimulation with tumor necrosis factor-alpha. The molecular dialogue between tumor necrosis factor-alpha and gingival epithelial cells involved modulation of the activities of p38MAPK, Jun N-terminal kinase and p44/42. Interestingly, only phosphorylation of p38MAPK contributed to more than half of the signaling initiated by tumor necrosis factor-alpha-elicited high-mobility-group box 1 release.
High-mobility-group box 1 is continuously released from the gingival epithelial cells modulated by tumor necrosis factor-alpha. These findings imply that high-mobility-group box 1 expression and possibly p38MAPK constitute important features in periodontitis.
高迁移率族蛋白B1作为一种晚期炎症介质发挥作用。它可由巨噬细胞和坏死细胞通过脂多糖和肿瘤坏死因子-α在细胞外释放。本研究的目的是明确慢性牙周炎组织和肿瘤坏死因子-α刺激的牙龈上皮细胞中高迁移率族蛋白B1的来源，随后阐明其诱导性炎症途径。
采用免疫组织化学和免疫荧光法对慢性牙周炎和健康牙龈切片进行高迁移率族蛋白B1染色。通过蛋白质印迹法检测肿瘤坏死因子-α刺激后释放到龈沟液中的高迁移率族蛋白B1量以及牙龈上皮细胞培养上清液中的高迁移率族蛋白B1量。同时检测牙龈上皮细胞中丝裂原活化蛋白激酶（MAPKs）的磷酸化情况。
在牙周炎患者的牙龈上皮细胞胞质和细胞核中检测到高迁移率族蛋白B1。蛋白质印迹法显示牙周炎患者龈沟液中高迁移率族蛋白B1表达显著增加。肿瘤坏死因子-α刺激后牙龈上皮细胞中高迁移率族蛋白B1的产生增加。肿瘤坏死因子-α与牙龈上皮细胞之间的分子对话涉及p38丝裂原活化蛋白激酶、应激活化蛋白激酶和p44/42活性的调节。有趣的是，p38丝裂原活化蛋白激酶的磷酸化对肿瘤坏死因子-α诱导的高迁移率族蛋白B1释放所引发的信号传导贡献超过一半。
高迁移率族蛋白B1由肿瘤坏死因子-α调节的牙龈上皮细胞持续释放。这些发现提示高迁移率族蛋白B1的表达以及可能的p38丝裂原活化蛋白激酶构成了牙周炎的重要特征。
