Division of Molecular Signaling and Biochemistry, Department of Biosciences, Center for Oral Biological Research, Kyushu Dental College, Fukuoka, Japan.
J Dent Res. 2011 Jul;90(7):912-7. doi: 10.1177/0022034511407335. Epub 2011 Apr 29.
Mineral trioxide aggregate (MTA), a commonly used endodontic repair material, is useful for both basic and clinical research, and the effect of MTA on osteoblast differentiation has been well-defined. However, the effects of MTA on osteoclastic bone resorption are not fully understood. Hence, the aim of this study is to examine the effect of MTA solution in the regulation of osteoclast bone-resorbing activity using osteoclasts formed in co-cultures of primary osteoblasts and bone marrow cells. MTA solution dose-dependently reduced the total area of pits formed by osteoclasts. The reduction of resorption induced by 20% MTA treatment was due to inhibition of osteoclastic bone-resorbing activity and had no effect on osteoclast number. A 20% MTA solution disrupted actin ring formation, a marker of osteoclastic bone resorption, by reducing phosphorylation and kinase activity of c-Src, and mRNA expressions of cathepsin K and mmp-9. A high concentration of MTA solution (50%) induced apoptosis of osteoclasts by increasing the expression of Bim, a member of the BH3-only (Bcl-2 homology) family of pro-apoptotic proteins. Taken together, our results suggest that MTA is a useful retrofilling material for several clinical situations because it both stimulates osteoblast differentiation and inhibits bone resorption.
矿化三氧化物凝聚体（MTA）是一种常用的牙髓修复材料，广泛应用于基础和临床研究，其对成骨细胞分化的影响已得到明确。然而，MTA 对破骨细胞骨吸收的影响尚未完全阐明。因此，本研究旨在通过原代成骨细胞和骨髓细胞共培养形成的破骨细胞来研究 MTA 溶液对破骨细胞骨吸收活性的调节作用。MTA 溶液呈剂量依赖性地减少破骨细胞形成的陷窝总面积。20% MTA 处理引起的吸收减少是由于抑制了破骨细胞的骨吸收活性，而对破骨细胞数量没有影响。20%的 MTA 溶液通过降低 c-Src 的磷酸化和激酶活性以及组织蛋白酶 K 和 MMP-9 的 mRNA 表达，破坏破骨细胞的肌动蛋白环形成，这是破骨细胞骨吸收的标志。高浓度的 MTA 溶液（50%）通过增加 Bim（BH3 仅结构域家族促凋亡蛋白）的表达诱导破骨细胞凋亡。总之，我们的研究结果表明，MTA 是一种有用的根管倒充填材料，因为它既能刺激成骨细胞分化，又能抑制骨吸收。
