Kim Ji-Hye, Lee Dong-Eun, Woo Gye-Hyeong, Cha Jeong-Heon, Bak Eun-Jung, Yoo Yun-Jung
Department of Oral Biology, Yonsei University College of Dentistry, Seoul, Republic of Korea.
BK21 PLUS Project, Yonsei University College of Dentistry.
J Periodontol. 2015 Aug;86(8):1005-11. doi: 10.1902/jop.2015.150083. Epub 2015 Apr 9.
Osteocytic sclerostin inhibits bone formation, and its expression is stimulated by tumor necrosis factor (TNF)-α. This study investigates sclerostin and TNF-α expression in rats with diabetes mellitus (DM) and periodontitis.
Rats were divided into control (C), periodontitis (P), and DM + periodontitis (DP) groups. After induction of DM by streptozotocin, periodontitis was induced by ligature. At day 0 (control) and at days 3 and 20 after induction of periodontitis, alveolar bone, osteoclasts, osteoid area, and TNF-α and sclerostin expression were evaluated.
The distance between the cemento-enamel junction and the alveolar bone crest of the DP group was longer than that of the P group at day 20 after induction of periodontitis, but the number of osteoclasts was not different. Osteoid area decreased in both the P and DP groups by day 3, but whereas sustained osteoid suppression was observed in the DP group at day 20, osteoid formation was increased in the P group. The number of sclerostin-positive osteocytes increased in both groups at day 3, but the increased number of sclerostin-positive osteocytes was maintained only in the DP group through day 20. The number of TNF-α-positive cells increased more in the DP group than in the P group.
Enhanced alveolar bone loss, suppressed bone formation, and prevalent TNF-α expression were characteristic of the DP group compared with the P group. Suppressed bone formation in the DP group was observed simultaneously with increased sclerostin and TNF-α expression. These results suggest that upregulated osteocytic sclerostin expression in periodontitis accompanied by DM may play a role in suppressed bone formation.
骨细胞性骨硬化蛋白抑制骨形成，其表达受肿瘤坏死因子（TNF）-α刺激。本研究调查糖尿病（DM）合并牙周炎大鼠中骨硬化蛋白和TNF-α的表达情况。
将大鼠分为对照组（C）、牙周炎组（P）和DM+牙周炎组（DP）。通过链脲佐菌素诱导DM后，采用结扎法诱导牙周炎。在第0天（对照组）以及诱导牙周炎后的第3天和第20天，评估牙槽骨、破骨细胞、类骨质面积以及TNF-α和骨硬化蛋白的表达。
诱导牙周炎后第20天，DP组牙骨质-釉质界与牙槽嵴顶之间的距离长于P组，但破骨细胞数量无差异。第3天时，P组和DP组的类骨质面积均减少，但到第20天时，DP组持续出现类骨质抑制，而P组类骨质形成增加。第3天时，两组中骨硬化蛋白阳性骨细胞数量均增加，但到第20天时，仅DP组中骨硬化蛋白阳性骨细胞数量持续增加。DP组中TNF-α阳性细胞数量的增加幅度大于P组。
与P组相比，DP组的特征为牙槽骨吸收增强、骨形成受抑制以及TNF-α表达普遍。DP组骨形成受抑制的同时骨硬化蛋白和TNF-α表达增加。这些结果表明，DM伴发的牙周炎中骨细胞性骨硬化蛋白表达上调可能在骨形成受抑制中起作用。
