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背景:认识增龄过程中成骨细胞和破骨细胞变化规律,特别是高龄人群成骨细胞和破骨细胞的生物学特点,对骨质疏松有效合理的防治具有十分重要的意义。目的:回顾关于成骨细胞和破骨细胞数量和活性增龄变化的实验及临床研究结果,明确增龄过程中成骨细胞和破骨细胞的变化规律和衰老特点。数据来源:1995/2003PubMed,2002/2004年万方数据库,本实验室研究结果。数据提取:PubMed16篇,万方数据库1篇,本实验室数据。主要观察指标:细胞数量、酶活性、基因表达水平。结果: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OPG表达失偶联。结论: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,作者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。
BACKGROUND: Understanding the changes of osteoblasts and osteoclasts during aging, especially the biological characteristics of osteoblasts and osteoclasts in elderly people, is of great significance for effective and reasonable prevention and treatment of osteoporosis. OBJECTIVE: To review the results of experiments and clinical studies on the changes of the number and activity of osteoblasts and osteoclasts, and to clarify the changing rules and aging characteristics of osteoblasts and osteoclasts during aging. Data source: 1995/2003 PubMed, Wanfang database of 2002/2004, the research results of our laboratory. Data extraction: PubMed16, Wanfang database 1, the laboratory data. MAIN OUTCOME MEASURES: Cell number, enzyme activity, gene expression level. Results: The effects of osteoblast formation and osteoclast resorption on bone in elderly population decreased gradually, but showed different characteristics. ① bone formation continued to decline, mainly as follows: osteoblast mitosis reduced ability to reduce matrix synthesis, decreased sensitivity to calmodulin. These changes are associated with a rapid reduction in precursor cells in the bone marrow, degenerating the population of osteoblastic cells in the elderly population due to a lack of newborn cells. ② transient activation of bone resorption, mainly as follows: the number of osteoclasts increased at once, and its acid secretion and protease function to be maintained. ③ osteoblast regulatory capacity decreased, mainly as osteoblasts in the expression of RANKL and OPG lost couple. CONCLUSION: The mechanism of osteoclast activation and the significance of osteoclast secondary activity to generate different bone balance are worth discussing. As a suggestion, the authors advocate the emphasis on the study of progenitor cell proliferation in bone marrow microenvironment in basic fields.