Department of Medical BioSciences, Radboud University Medical Center, Geert Grooteplein Zuid 28, 6525GA Nijmegen, The Netherlands.
Department of Medical BioSciences, Radboud University Medical Center, Geert Grooteplein Zuid 28, 6525GA Nijmegen, The Netherlands; Electron Microscopy Center, Radboudumc Technology Center Microscopy, Radboud University Medical Center, Geert Grooteplein Noord 29, 6525EZ Nijmegen, The Netherlands.
J Struct Biol. 2024 Jun;216(2):108096. doi: 10.1016/j.jsb.2024.108096. Epub 2024 Apr 30.
The bone extracellular matrix consists of a highly organized collagen matrix that is mineralized with carbonated hydroxyapatite. Even though the structure and composition of bone have been studied extensively, the mechanisms underlying collagen matrix organization remain elusive. In this study, we used a 3D cell culture system in which osteogenic cells deposit and orient the collagen matrix that is subsequently mineralized. Using live fluorescence imaging combined with volume electron microscopy, we visualize the organization of the cells and collagen in the cell culture. We show that the osteogenically induced cells are organizing the collagen matrix during development. Based on the observation of tunnel-like structures surrounded by aligned collagen in the center of the culture, we propose that osteoblasts organize the deposited collagen during migration through the culture. Overall, we show that cell-matrix interactions are involved in collagen alignment during early-stage osteogenic differentiation and that the matrix is organized by the osteoblasts in the absence of osteoclast activity.
骨细胞外基质由高度有序的胶原基质组成，该基质矿化为碳酸羟基磷灰石。尽管骨的结构和组成已经得到了广泛的研究，但胶原基质组织的机制仍然难以捉摸。在这项研究中，我们使用了一种 3D 细胞培养系统，成骨细胞在该系统中沉积并定向胶原基质，随后该胶原基质矿化。我们使用活荧光成像结合体视电子显微镜，可视化细胞和细胞培养中胶原的组织。我们表明，成骨诱导细胞在发育过程中组织胶原基质。基于在培养物中心被排列胶原包围的隧道样结构的观察，我们提出成骨细胞在通过培养物迁移时组织沉积的胶原。总的来说，我们表明细胞-基质相互作用参与成骨分化早期的胶原排列，并且在没有破骨细胞活性的情况下，基质由成骨细胞组织。
