增龄后成骨细胞和破骨细胞的生物学特性

骨质疏松或增龄性骨丢失与老年人成骨细胞和破骨细胞的功能特点密切相关。尽管高龄人群成骨细胞骨形成作用和破骨细胞骨吸收作用对骨骼的影响都逐渐下降,但表现出不同的特点。(1)骨形成功能持续降低,主要表现为:成骨细胞分裂增生能力降低、基质合成减少、对钙调激素的敏感性降低。这些变化与骨髓中前体细胞的快速减少有关,使高龄人群骨骼中成骨细胞群由于缺乏新生细胞的不断补充而功能退化。(2)骨吸收功能短暂激活,主要表现为:破骨细胞数量一度增加,而其泌酸和蛋白酶功能基本得以保持。(3)成骨细胞调节能力降低,主要表现为成骨细胞中RANKL和OPC表达失偶联。破骨细胞激活的机制和破骨细胞二次活跃产生不同骨平衡的意义值得探讨。作为建议,我们提倡在基础领域重视骨髓微环境中前体细胞分化增殖的研究。

Osteoblasts and Osteoclasts Changes with Age

Osteoporosis or age-related bone loss was related the cell number and its activity of osteoblasts and osteoclasts.Although their influences on bone were declined with age,they changed with different pattems in the aged as follows:1.The continuing decrease of osteoblast function,including the reduced growth capacity,the decreased matrix forming ability,the weak response to hormones or cytokines and the lower differentiation from BMSCs.Without renewal from progenitor,the osteoblasts in old person was more senescent.2.The transient activation of os- teoclast,showed by the temporary increase of cell number and mostly maintenance of its resorption ability.3.The defect of the control ability of osteoblasts,maiuly showed by the uncoupling of RANKL and OPG expression in the aged.We would further discuss that,what caused the tran- sient active of osteoclasts and why the two similarly activation of osteoclasts made different results.As a recommendation,we should make more at- tention on precursors differentiation in bone marrow.