Division of Comprehensive Dentistry, Tohoku University Dental Hospital, Sendai, Japan.
J Periodontal Res. 2010 Jun;45(3):309-16. doi: 10.1111/j.1600-0765.2009.01237.x. Epub 2009 Nov 9.
MMP-2 can degrade type IV collagen and MMP-14 can activate pro MMP-2. The present study was undertaken to examine the expression of MMP-2 and MMP-14 with respect to interaction between the cells of the epithelial rests of Malassez and fibroblasts from human periodontal ligament.
Explants of human periodontal ligament tissues produced outgrowths containing both putative epithelial rests of Malassez cells and human periodontal ligament fibroblasts after incubation in a modified serum-free medium. The distribution and expression of MMP-2 and MMP-14 were analysed using immunohistochemistry, in situ hybridization and RT-PCR analysis. The conditioned media and cell extracts were collected for western blot analysis for MMP-2.
Putative epithelial rests of Malassez cells at the interface between the cells of the epithelial rests of Malassez and fibroblasts expressed MMP-2 and MMP-14 strongly. However, in situ hybridization analysis revealed that human periodontal ligament fibroblasts expressed MMP-2 mRNA while putative epithelial rests of Malassez cells expressed MMP-14 mRNA at the interface. The RT-PCR analysis showed that the expression of MMP-2 mRNA was significantly higher when putative epithelial rests of Malassez cells and human periodontal ligament fibroblasts were cultured together than when cultured alone. Western blot analysis showed that the active form of MMP-2 was detected at higher levels in the conditioned medium of the co-cultured cells.
These findings indicate that putative epithelial rests of Malassez cells stimulate the production of MMP-2 in human periodontal ligament fibroblasts. Up-regulated proMMP-2 bound by MMP-14 expressed in epithelial rests of Malassez cells can degrade matrix molecules, such as type IV collagen, in the basal membrane between putative epithelial rests of Malassez cells and human periodontal ligament fibroblasts.
MMP-2 可降解 IV 型胶原，MMP-14 可激活 pro MMP-2。本研究旨在观察上皮根鞘细胞与牙周膜成纤维细胞之间相互作用时 MMP-2 和 MMP-14 的表达。
在改良的无血清培养基中孵育牙周膜组织的组织外植体后，产生包含上皮根鞘细胞和人牙周膜成纤维细胞的突起。使用免疫组织化学、原位杂交和 RT-PCR 分析来分析 MMP-2 和 MMP-14 的分布和表达。收集条件培养基和细胞提取物进行 MMP-2 的 Western blot 分析。
上皮根鞘细胞与成纤维细胞界面处的上皮根鞘细胞表达 MMP-2 和 MMP-14。然而，原位杂交分析显示，人牙周膜成纤维细胞表达 MMP-2 mRNA，而上皮根鞘细胞表达 MMP-14 mRNA。RT-PCR 分析显示，当上皮根鞘细胞和人牙周膜成纤维细胞共培养时，MMP-2 mRNA 的表达显著高于单独培养时。Western blot 分析显示，共培养细胞的条件培养基中检测到 MMP-2 的活性形式水平更高。
这些发现表明上皮根鞘细胞刺激人牙周膜成纤维细胞产生 MMP-2。表达在上皮根鞘细胞中的上调的 proMMP-2 与 MMP-14 结合，可以降解上皮根鞘细胞和人牙周膜成纤维细胞之间基膜中的基质分子，如 IV 型胶原。
