Palosaari H, Wahlgren J, Larmas M, Rönkä H, Sorsa T, Salo T, Tjäderhane L
Institute of Dentistry, University of Oulu, Finland.
J Dent Res. 2000 Jan;79(1):77-84. doi: 10.1177/00220345000790011401.
Recent findings show that matrix metalloproteinase-8 (MMP-8) is expressed, in addition to neutrophils, by human chondrocytes, cultured fibroblasts, and endothelial cells. We investigated the expression of MMP-8 in other human mesenchyme-derived cells, odontoblasts, and pulp tissue. Odontoblasts and pulp tissue were collected from extracted human teeth for MMP-8 mRNA analysis with reverse-transcription/polymerase chain-reaction (RT-PCR) and Southern blot. The expression, localization, and secretion of MMP-8 protein were studied with Western blot, immunohistochemistry, and immunofluorometric assay. The effect of TGF-beta1 (10 ng/mL) on the expression, secretion, and concentration of secreted MMP-8 was studied by odontoblast and pulp tissue culture methods (Tjäderhane et al., 1998a). RT-PCR demonstrated MMP-8 mRNA expression in native and cultured odontoblasts and pulp tissue and cultured pulp fibroblasts, with a 522-bp transcript comparable with that of bone marrow cells. The specificity of PCR was confirmed with Southern blot. Western blot with MMP-8-specific antibody detected 65- and 50-kDa proteins in native samples, representing latent and active forms of mesenchymal-type MMP-8, and in the conditioned odontoblast culture media, 50-kDa protein was observed. TGF-beta down-regulated the MMP-8 mRNA and concentration of secreted protein in both cultures. Immunohistochemical staining detected MMP-8 in odontoblasts. These findings indicate that mesenchyme-derived cells of the dentin-pulp complex express, synthesize, and activate MMP-8, which may, in concert with odontoblast-derived gelatinases, participate in organization of dentin organic matrix prior to mineralization.
最近的研究结果表明，除中性粒细胞外，人软骨细胞、培养的成纤维细胞和内皮细胞也表达基质金属蛋白酶8（MMP-8）。我们研究了MMP-8在其他人间充质来源细胞、成牙本质细胞和牙髓组织中的表达。从拔除的人牙齿中收集成牙本质细胞和牙髓组织，用于通过逆转录/聚合酶链反应（RT-PCR）和Southern印迹法进行MMP-8 mRNA分析。通过蛋白质印迹法、免疫组织化学和免疫荧光测定法研究MMP-8蛋白的表达、定位和分泌。通过成牙本质细胞和牙髓组织培养方法（Tjäderhane等人，1998a）研究了转化生长因子-β1（10 ng/mL）对分泌的MMP-8的表达、分泌和浓度的影响。RT-PCR显示天然和培养的成牙本质细胞、牙髓组织以及培养的牙髓成纤维细胞中有MMP-8 mRNA表达，其522 bp的转录本与骨髓细胞的相当。通过Southern印迹法证实了PCR的特异性。用MMP-8特异性抗体进行的蛋白质印迹法在天然样品中检测到65 kDa和50 kDa的蛋白，分别代表间充质型MMP-8的潜伏形式和活性形式，在成牙本质细胞条件培养基中观察到50 kDa的蛋白。转化生长因子-β在两种培养物中均下调MMP-8 mRNA和分泌蛋白的浓度。免疫组织化学染色在成牙本质细胞中检测到MMP-8。这些发现表明，牙本质-牙髓复合体的间充质来源细胞表达、合成并激活MMP-8，其可能与成牙本质细胞来源的明胶酶协同作用，参与矿化前牙本质有机基质的组织形成。
