Bone remodeling
Bone remodeling
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DOI：
10.1196/annals.1365.035
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发表时间：
2006-01-01
期刊：
影响因子：
--
通讯作者：
Androulakis, Ioannis I.
中科院分区：
文献类型：
--
作者：
Hadjidakis, Dimitrios J.;Androulakis, Ioannis I.
骨骼是一个代谢活跃的器官，在整个生命过程中不断重塑。骨重建涉及通过破骨细胞去除矿化骨，随后通过成骨细胞形成骨基质，所述成骨细胞随后变成矿化的。重塑周期由三个连续的阶段组成：再吸收，在此期间破骨细胞消化旧骨;逆转，当单核细胞出现在骨表面时;和形成，当成骨细胞沉积新骨直到被再吸收的骨被完全取代。骨重建的作用是调整骨结构以适应不断变化的力学需求，并有助于修复骨基质中的微损伤，防止旧骨的积累。它在维持血浆钙稳态方面也起着重要作用。骨重建的调节是系统性的和局部的。主要的全身调节剂包括甲状旁腺激素（PTH）、钙三醇以及其他激素，如生长激素、糖皮质激素、甲状腺激素和性激素。诸如胰岛素样生长因子（IGFs）、胰高血糖素、肿瘤生长因子-β（TGF-β）、骨形态发生蛋白（BMP）和细胞因子等因子也参与其中。就骨重建的局部调节而言，最近已经鉴定了大量影响骨细胞功能的细胞因子和生长因子。此外，通过RANK/NF-κ B受体激活剂配体（RANKL）/骨保护素（OPG）系统，骨吸收和形成过程紧密耦合，允许骨形成波跟随每个骨吸收周期，从而保持骨骼完整性。
The skeleton is a metabolically active organ that undergoes continuous remodeling throughout life. Bone remodeling involves the removal of mineralized bone by osteoclasts followed by the formation of bone matrix through the osteoblasts that subsequently become mineralized. The remodeling cycle consists of three consecutive phases: resorption, during which osteoclasts digest old bone; reversal, when mononuclear cells appear on the bone surface; and formation, when osteoblasts lay down new bone until the resorbed bone is completely replaced. Bone remodeling serves to adjust bone architecture to meet changing mechanical needs and it helps to repair microdamages in bone matrix preventing the accumulation of old bone. It also plays an important role in maintaining plasma calcium homeostasis. The regulation of bone remodeling is both systemic and local. The major systemic regulators include parathyroid hormone (PTH), calcitriol, and other hormones such as growth hormone, glucocorticoids, thyroid hormones, and sex hormones. Factors such as insulin-like growth factors (IGFs), prostaglandins, tumor growth factor-beta (TGF-beta), bone morphogenetic proteins (BMP), and cytokines are involved as well. As far as local regulation of bone remodeling is concerned, a large number of cytokines and growth factors that affect bone cell functions have been recently identified. Furthermore, through the RANK/receptor activator of NF-kappa B ligand (RANKL)/osteoprotegerin (OPG) system the processes of bone resorption and formation are tightly coupled allowing a wave of bone formation to follow each cycle of bone resorption, thus maintaining skeletal integrity.