Does collagen trigger the recruitment of osteoblasts into vacated bone resorption lacunae during bone remodeling?
Does collagen trigger the recruitment of osteoblasts into vacated bone resorption lacunae during bone remodeling?
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DOI：
10.1016/j.bone.2014.07.012
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发表时间：
2014-10-01
期刊：
影响因子：
4.1
通讯作者：
Delaisse, Jean-Marie
中科院分区：
文献类型：
--
作者：
Abdelgawad, Mohamed Essameldin;Soe, Kent;Delaisse, Jean-Marie
骨重建过程中的成骨细胞募集对于重建被破骨细胞吸收的骨是必需的。这种募集被认为是由破骨细胞产物触发的，因此可能在重建周期的早期开始。已知几种具有成骨细胞募集潜力的破骨细胞产品。在这里，我们提请注意的成骨细胞招聘潜力的胶原蛋白，是新鲜脱矿的破骨细胞我们的证据是基于观察成人松质骨，结合体外试验。首先，新侵蚀的表面，成骨细胞必须招募显示存在非降解的脱矿胶原蛋白和密切的细胞-胶原蛋白相互作用，如电子显微镜所示，而表面结合的胶原蛋白强烈吸引成骨细胞谱系细胞在跨膜迁移测定。与其他细胞外基质分子相比，胶原蛋白的活性上级，仅与纤维连接蛋白相当。接下来，大多数新募集的成骨细胞谱系细胞紧邻破骨细胞，显示uPARAP/Endo 180，一种内吞胶原蛋白受体，据报道参与各种细胞类型中的胶原蛋白内化和细胞迁移，据报道其失活导致骨形成缺乏和骨骼畸形。在本研究中，针对该受体的抗体抑制成骨细胞系细胞中的胶原内化，并在一定程度上降低它们在跨膜迁移测定中向表面结合的胶原的迁移。这些互补的观察结果导致了一个模型，其中破骨细胞脱矿的胶原蛋白将周围的骨祖细胞吸引到侵蚀的表面上，并且内吞胶原蛋白受体uPARAP/Endo 180可能与其他胶原蛋白受体一起促成了这种迁移。这个模型符合最近的知识骨祖细胞的位置紧挨着成人松质骨的重塑网站。(C)2014作者爱思唯尔公司出版这是CC BY-NC-ND许可下的开放获取文章（http：//creativecommons.org/licenses/by-nc-nd/3.0/）。
Osteoblast recruitment during bone remodeling is obligatory to re-construct the bone resorbed by the osteoclast This recruitment is believed to be triggered by osteoclast products and is therefore likely to start early during the remodeling cycle. Several osteoclast products with osteoblast recruitment potential are already known. Here we draw the attention on the osteoblast recruitment potential of the collagen that is freshly demineralized by the osteoclast Our evidence is based on observations on adult human cancellous bone, combined with in vitro assays. First, freshly eroded surfaces where osteoblasts have to be recruited show the presence of non-degraded demineralized collagen and close cell-collagen interactions, as revealed by electron microscopy, while surface-bound collagen strongly attracts osteoblast lineage cells in a transmembrane migration assay. Compared with other extracellular matrix molecules, collagen's potency was superior and only equaled by fibronectin. Next, the majority of the newly recruited osteoblast lineage cells positioned immediately next to the osteoclasts exhibit uPARAP/Endo180, an endocytic collagen receptor reported to be involved in collagen internalization and cell migration in various cell types, and whose inactivation is reported to lead to lack of bone formation and skeletal deformities. In the present study, an antibody directed against this receptor inhibits collagen internalization in osteoblast lineage cells and decreases to some extent their migration to surface-bound collagen in the transmembrane migration assay. These complementary observations lead to a model where collagen demineralized by osteoclasts attracts surrounding osteoprogenitors onto eroded surfaces, and where the endocytic collagen receptor uPARAP/Endo180 contributes to this migration, probably together with other collagen receptors. This model fits recent knowledge on the position of osteoprogenitor cells immediately next to remodeling sites in adult human cancellous bone. (C) 2014 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).