骨细胞的功能：生物学研究和机理探讨

骨细胞（osteocyte）是在矿化骨基质内名副其实的骨的细胞（bonecell）。通过细胞突触，骨细胞彼此相连，很可能也与骨髓中某些细胞相接，从而形成三维细胞网络。从骨的超微结构看，骨细胞处于很理想的位置，可以担当骨生理的重要调节因子。然而，由于骨细胞处于矿化骨基质深层，对其功能了解甚少。但随着新技术方法的应用，就有可能对这种成骨细胞系中的终末分化细胞进行深入研究，人们也由此对骨细胞的兴趣大增。骨细胞被认为是骨的机械应力感受器，它有可能参与骨重建。骨细胞能分泌具有调节成骨细胞功能的硬骨素（sclerostin）。一种能降低肾脏磷回吸收的激素——调磷因子FGF23也主要源白骨细胞。随着我们对骨细胞了解的深入，清楚显示，骨细胞不仅能影响局部骨转换活性，而且对全身矿物质的体内平衡也有多种功能。因此，对骨细胞的研究，可以为代谢性骨病的治疗探索新的途径。

Osteocyte Function: Biology and Mechanisms

Osteocytes are actual bone cells inside mineralized bone matrix. They are connected to each other and perhaps also to some other cells in the bone marrow by cellular protrusions to form a three-dimensional cellular net-work. From the point of view of bone microstructure, osteocytes are ideally located for being important regulators of bone physiology. However, due to their location deep in mineralized bone matrix, the function of osteoyctes is poorly under- stood. Interest in osteocytes is rapidly increasing, since new methods and technologies give new possibilities to study this terminally differentiated cell of the osteogenic cell lineage. Osteocytes are considered to be bone mechanosensors and could thus regulate bone remodeling. It was also been shown that osteocytes secret sclerostin, which regulates osteoblast func- tion. Osteocytes are main source of FGF23, which is a hormone that regulates kidney function by decreasing phosphate uptake. As our understanding of osteocytes increases, it has become clear that osteocytes not only influence local bone turnover activity, but also has more far reaching functions in whole body mineral homeostasis. The research of osteocytes will open up new possibilities for novel treatment of metabolic bone diseases.