Bone formation, for example during bone remodelling or fracture repair, requires mature osteoblasts to deposit bone with remarkable spatial precision. As osteoblast precursors derive either from circulation or resident stem cell pools, they and their progeny are required to migrate within the three‐dimensional bone space and to navigate to their destination, i.e. to the site of bone formation. An understanding of this process is emerging based on in vitro and in vivo studies of several vertebrate species. Receptors on the osteoblast surface mediate cell adhesion and polarization, which induces osteoblast migration. Osteoblast migration is then facilitated along gradients of chemoattractants. The latter are secreted or released proteolytically by several cell types interacting with osteoblasts, including osteoclasts and vascular endothelial cells. The positions of these cellular sources of chemoattractants in relation to the position of the osteoblasts provide the migrating osteoblasts with tracks to their destination, and osteoblasts possess the means to follow a track marked by multiple chemoattractant gradients. In addition to chemotactic cues, osteoblasts sense other classes of signals and utilize them as landmarks for navigation. The composition of the osseous surface guides adhesion and hence migration efficiency and can also provide steering through haptotaxis. Further, it is likely that signals received from surface interactions modulate chemotaxis. Besides the nature of the surface, mechanical signals such as fluid flow may also serve as navigation signals for osteoblasts. Alterations in osteoblast migration and navigation might play a role in metabolic bone diseases such as osteoporosis.

中文翻译：

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脊椎动物骨骼中的成骨细胞迁移

骨形成，例如在骨重塑或骨折修复期间，需要成熟的成骨细胞以显着的空间精度沉积骨。由于成骨细胞前体来源于循环或常驻干细胞池，它们及其后代需要在三维骨空间内迁移并导航到目的地，即骨形成部位。基于对几种脊椎动物物种的体外和体内研究，对这一过程的理解正在浮现。成骨细胞表面的受体介导细胞粘附和极化，从而诱导成骨细胞迁移。然后沿着化学引诱物的梯度促进成骨细胞迁移。后者由与成骨细胞相互作用的几种细胞类型以蛋白水解方式分泌或释放，包括破骨细胞和血管内皮细胞。这些化学引诱物的细胞来源相对于成骨细胞的位置的位置为迁移的成骨细胞提供了到达目的地的轨迹，并且成骨细胞拥有遵循由多个化学引诱物梯度标记的轨迹的手段。除了趋化线索外，成骨细胞还能感知其他类别的信号并将它们用作导航的地标。骨表面的组成引导粘附，从而引导迁移效率，并且还可以通过趋触性提供转向。此外，从表面相互作用接收到的信号可能会调节趋化性。除了表面的性质，流体流动等机械信号也可以作为成骨细胞的导航信号。