3D Interrelationship between Osteocyte Network and Forming Mineral during Human Bone Remodeling
3D Interrelationship between Osteocyte Network and Forming Mineral during Human Bone Remodeling
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DOI：
10.1002/adhm.202100113
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发表时间：
2021-05-08
影响因子：
10
通讯作者：
Fratzl, Peter
中科院分区：
文献类型：
--
作者：
Ayoubi, Mahdi;van Tol, Alexander F.;Fratzl, Peter
在骨重塑过程中，已知成骨细胞存款未矿化的胶原组织（类骨质），其矿化后一段时间的滞后。一些成骨细胞分化成骨细胞，在骨的腔隙小管网络（LCN）内形成细胞网络。为了更深入地了解骨细胞在类骨质矿化过程中的潜在作用，使用聚焦离子束扫描电子显微镜（FIB-SEM）在9个形成的人骨单位中对骨形成部位进行三维成像。与先前的观察结果一致，发现矿物质浓度从中央哈弗氏管向预先存在的矿化骨逐渐增加。最有趣的是，在一个比LCN小100倍的长度尺度上发现了一个类似的特征，由此矿物浓度从LCN增加，在小管周围留下一个几乎没有矿物的区域，其大小随着矿化的进行而减小。这表明LCN控制矿物形成，但不仅仅是通过矿化前体的扩散，这将导致LCN的矿物浓度持续下降。然而，观察结果与前体和抑制剂从LCN进入骨基质的共扩散和反应是一致的。
During bone remodeling, osteoblasts are known to deposit unmineralized collagenous tissue (osteoid), which mineralizes after some time lag. Some of the osteoblasts differentiate into osteocytes, forming a cell network within the lacunocanalicular network (LCN) of bone. To get more insight into the potential role of osteocytes in the mineralization process of osteoid, sites of bone formation are three-dimensionally imaged in nine forming human osteons using focused ion beam-scanning electron microscopy (FIB-SEM). In agreement with previous observations, the mineral concentration is found to gradually increase from the central Haversian canal toward pre-existing mineralized bone. Most interestingly, a similar feature is discovered on a length scale more than 100-times smaller, whereby mineral concentration increases from the LCN, leaving around the canaliculi a zone virtually free of mineral, the size of which decreases with progressing mineralization. This suggests that the LCN controls mineral formation but not just by diffusion of mineralization precursors, which would lead to a continuous decrease of mineral concentration from the LCN. The observation is, however, compatible with the codiffusion and reaction of precursors and inhibitors from the LCN into the bone matrix.