Max Planck Institute of Colloids and Interfaces, Department of Biomaterials, Potsdam, Germany.
J Struct Biol. 2011 Feb;173(2):303-11. doi: 10.1016/j.jsb.2010.11.014. Epub 2010 Nov 23.
Bone is a dynamic tissue that is continually undergoing a process of remodeling - an effect due to the interplay between bone resorption by osteoclasts and bone formation by osteoblasts. When new bone is deposited, some of the osteoblasts are embedded in the mineralizing collagen matrix and differentiate to osteocytes, forming a dense network throughout the whole bone tissue. Here, we investigate the extent to which the organization of the osteocyte network controls the collagen matrix arrangement found in various bone tissues. Several tissue types from equine, ovine and murine bone have been examined using confocal laser scanning microscopy as well as polarized light microscopy and back-scattered electron imaging. From comparing the spatial arrangements of unorganized and organized bone, we propose that the formation of a highly oriented collagen matrix requires an alignment of osteoblasts whereby a substrate layer provides a surface such that osteoblasts can align and, collectively, build new matrix. Without such a substrate, osteoblasts act isolated and only form matrices without long range order. Hence, we conclude that osteoblasts synthesize and utilize scaffold-like primary tissue as a guide for the deposition of highly ordered and mechanically competent bone tissue by a collective action of many cells.
骨骼是一种不断进行重塑的动态组织——这种效应是由于破骨细胞的骨吸收和成骨细胞的骨形成之间的相互作用所致。当新骨沉积时，一些成骨细胞嵌入矿化的胶原基质中并分化为骨细胞，在整个骨组织中形成密集的网络。在这里，我们研究了骨细胞网络的组织在多大程度上控制着各种骨组织中发现的胶原基质排列。使用共聚焦激光扫描显微镜以及偏光显微镜和背散射电子成像检查了来自马、羊和鼠骨的几种组织类型。通过比较无组织和有组织骨的空间排列，我们提出形成高度取向的胶原基质需要成骨细胞的对齐，其中基底层提供表面，使得成骨细胞可以对齐并共同构建新的基质。没有这样的基底，成骨细胞的作用是孤立的，只能形成没有长程有序的基质。因此，我们得出结论，成骨细胞合成和利用支架样原组织作为许多细胞集体作用的指导，用于沉积高度有序和机械上有能力的骨组织。
