Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University, Sendai, Japan.
Division of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Tohoku University, Sendai, Japan.
Front Endocrinol (Lausanne). 2023 May 24;14:1121727. doi: 10.3389/fendo.2023.1121727. eCollection 2023.
The skeleton is an organ of dual functionality; on the one hand, it provides protection and structural competence. On the other hand, it participates extensively in coordinating homeostasis globally given that it is a mineral and hormonal reservoir. Bone is the only tissue in the body that goes through strategically consistent bouts of bone resorption to ensure its integrity and organismal survival in a temporally and spatially coordinated process, known as bone remodeling. Bone remodeling is directly enacted by three skeletal cell types, osteoclasts, osteoblasts, and osteocytes; these cells represent the acting force in a basic multicellular unit and ensure bone health maintenance. The osteocyte is an excellent mechanosensory cell and has been positioned as the choreographer of bone remodeling. It is, therefore, not surprising that a holistic grasp of the osteocyte entity in the bone is warranted. This review discusses osteocytogenesis and associated molecular and morphological changes and describes the osteocytic lacunocanalicular network (LCN) and its organization. We highlight new knowledge obtained from transcriptomic analyses of osteocytes and discuss the regulatory role of osteocytes in promoting osteoclastogenesis with an emphasis on the case of osteoclastogenesis in anosteocytic bones. We arrive at the conclusion that osteocytes exhibit several redundant means through which osteoclast formation can be initiated. However, whether osteocytes are true "orchestrators of bone remodeling" cannot be verified from the animal models used to study osteocyte biology . Results from studying osteocyte biology using current animal models should come with the caveat that these models are not osteocyte-specific, and conclusions from these studies should be interpreted cautiously.
骨骼是一种具有双重功能的器官；一方面，它提供保护和结构能力。另一方面，由于它是矿物质和激素的储存库，因此它广泛参与协调全身的内稳态。骨骼是体内唯一一种经历有策略地一致的骨吸收以确保其完整性和机体生存的组织，这一过程称为骨重建。骨重建由三种骨骼细胞类型直接实施，即破骨细胞、成骨细胞和成骨细胞；这些细胞代表基本多细胞单位中的作用力量，并确保骨骼健康的维持。成骨细胞是一种出色的机械敏感细胞，已被定位为骨重建的编舞者。因此，全面掌握骨骼中的成骨细胞实体是必要的。这篇综述讨论了成骨细胞的发生及其相关的分子和形态变化，并描述了成骨细胞的骨陷窝-骨小管网络（LCN）及其组织。我们强调了从成骨细胞转录组分析中获得的新知识，并讨论了成骨细胞在促进破骨细胞生成中的调节作用，重点是在无成骨细胞骨骼中破骨细胞生成的情况。我们得出的结论是，成骨细胞表现出几种冗余的方式，可以启动破骨细胞的形成。然而，从用于研究成骨细胞生物学的动物模型中，无法验证成骨细胞是否是真正的“骨重建的编舞者”。使用当前动物模型研究成骨细胞生物学的结果应该带有警告，即这些模型不是特异性针对成骨细胞的，并且应该谨慎解释这些研究的结论。
