Haas D W, Holick M F
Department of Medicine, Boston University Medical Center, Boston, Massachusetts 02118, USA.
Calcif Tissue Int. 1996 Sep;59(3):200-6. doi: 10.1007/s002239900109.
Osteonectin provided a spatial and temporal marker for proliferating and differentiating chondrocytes, and during the chondroid matrix formation. The goal of this investigation was to examine early cellular and molecular regulation of mandibular growth. Unloading was induced by anterior functional mastication. The proliferative activity measured by tritiated thymidine incorporation increased 8. 3-fold at 24 hours compared with the corresponding control group. Mandibular unloading for 24 hours increased osteonectin mRNA expression 60% in the condyle over the corresponding control group. Microscopic inspection of the condyle demonstrated osteonectin immunostaining of proliferating, early hypertrophic chondrocytes, and the chondroid matrix across the sagittal section in an anterior-posterior direction. An increasing gradient intensity from a medial-superior to posterior direction was produced with treatment in direct contrast to the control group. The posterior chondroid matrix immunostaining increased 11.7-fold (P = 0.038) after 24 hours treatment over a corresponding control group. Unloading of the mouse mandible caused an increased cellular proliferation, a coincident increase of osteonectin mRNA, and a subsequent increased secretion of the osteonectin protein in the chondroid matrix formation.
骨连接蛋白为增殖和分化的软骨细胞以及类软骨基质形成过程提供了一个时空标记。本研究的目的是探讨下颌生长的早期细胞和分子调控。通过前伸功能性咀嚼诱导卸载。与相应对照组相比，在24小时时，通过掺入氚标记胸腺嘧啶核苷测量的增殖活性增加了8.3倍。下颌卸载24小时，与相应对照组相比，髁突中骨连接蛋白mRNA表达增加了60%。对髁突的显微镜检查显示，在矢状切面的前后方向上，增殖的早期肥大软骨细胞和类软骨基质有骨连接蛋白免疫染色。与对照组形成直接对比，处理后从内侧上方向后方产生了一个递增的梯度强度。处理24小时后，与相应对照组相比，后类软骨基质免疫染色增加了11.7倍（P = 0.038）。小鼠下颌的卸载导致细胞增殖增加、骨连接蛋白mRNA同步增加以及随后在类软骨基质形成中骨连接蛋白分泌增加。
