Department of Orthodontics and Craniofacial Developmental Biology, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan.
Cells Tissues Organs. 2012;196(5):411-9. doi: 10.1159/000335912. Epub 2012 May 30.
Amelogenins are the major constituent of developing extracellular enamel matrix proteins and are understood to have an exclusively epithelial origin. Recent studies have demonstrated that amelogenins can be detected in other tissues, including bone marrow mesenchymal stem cells (MSCs), but the role of amelogenins in MSCs remains unclear. The purpose of this study was to examine the effect of recombinant human full-length amelogenin (rh174) on the osteogenic differentiation of cultured human MSCs. MSCs isolated from human bone marrow were cultured in osteoblastic differentiation medium with 0, 10 or 100 ng/ml rh174. The mRNA levels of bone markers were examined by real-time PCR analysis. Alkaline phosphatase (ALP) activity and calcium concentration were determined. Mineralization was evaluated by alizarin red staining. The mRNA levels of ALP, type I collagen, osteopontin and bone sialoprotein in the MSCs treated with rh174 became significantly higher than those in non-treated controls. Treatment of MSCs with rh174 also enhanced ALP activity and calcium concentration, resulting in enhanced mineralization, as denoted by high intensity of alizarin red staining. In conclusion, the present study showed that rh174 enhances the mineralization accompanied by the upregulation of bone markers in human bone marrow MSCs during osteogenic differentiation, suggesting a certain role of amelogenin in the modulation of osteogenic differentiation of MSCs.
釉原蛋白是发育中细胞外釉基质蛋白的主要成分，被认为具有纯上皮来源。最近的研究表明，釉原蛋白可以在其他组织中检测到，包括骨髓间充质干细胞（MSCs），但釉原蛋白在 MSCs 中的作用尚不清楚。本研究旨在探讨重组人全长釉原蛋白（rh174）对培养的人 MSCs 成骨分化的影响。从人骨髓中分离的 MSCs 在成骨分化培养基中培养，加入 0、10 或 100ng/ml rh174。通过实时 PCR 分析检测骨标志物的 mRNA 水平。测定碱性磷酸酶（ALP）活性和钙浓度。通过茜素红染色评估矿化。rh174 处理的 MSCs 中 ALP、I 型胶原、骨桥蛋白和骨唾液蛋白的 mRNA 水平明显高于未处理对照组。rh174 处理还增强了 MSCs 的 ALP 活性和钙浓度，导致矿化增强，茜素红染色强度高。总之，本研究表明 rh174 增强了人骨髓 MSCs 成骨分化过程中的矿化，并上调了骨标志物的表达，提示釉原蛋白在调节 MSCs 成骨分化中具有一定作用。
