骨质疏松症成骨细胞生物学特征的体外研究

In vitro study on biological characteristic changes in osteoblasts from patients with osteoporosis

目的 建立成人和骨质疏松症成骨细胞培养方法;体外探讨骨质疏松成骨细胞特征性表型的变化。方法 取年轻人和骨质疏松患者,采用骨碎片培养和酶消化技术,分离、培养成骨细胞,体外观察细胞生长和转化状况,并用生物化学、放射免疫和RT-PCR技术检测成骨细胞表型。 结果骨碎片培养和多阶段酶消化相结合,可获得数量多、纯度高的成骨细胞;体外培养条件下,生长中、晚期的骨质疏松症成骨细胞可向成纤维细胞样细胞形态转化,骨钙索、碱性磷酸酶和Ⅰ型胶原的分泌功能部分丧失,并表达非特异性Ⅲ型胶原,而呈现成纤维细胞样变。结论 骨质疏松成骨细胞可发生退变,并有可能是骨质疏松症发生骨基质成分不足、骨基质钙化不完全、骨组织结构改建不良的重要因素之一。

Objective To study whether intrinsic abnormality in osteoblast function contributes to the decreased bone formation in osteoporosis. Methods Cancellous bone fragments of femoral head obtained from 6 patients with osteoporosis. After joint replacement were used as experimental specimen and those from 4 young patients with dysplasia of hip joint after joint replacement and 2 normal young men dead in traffic accident served as controls. These cancellous bone fragments were cultured and digested with trypsin to isolate and purify osteoblasts, which were then cultured and subjected to inverted phase-contrast microcopy. After the osteoblasts were cultured for three weeks, the markers for osteogenic features were investigated by biochemistry, histochemistry, radioimmuno-assay and RT-PCR. Results The method of culture combined with digestion could obtain numerous and pure osteoblasts from cancellous bone fragments. Compared with special phenotype of osteoblasts, the osteoblasts from patients with osteoporosis presented fibroblast-like appearance, the cell differentiation markers (alkaline phosphatase, collagen type Ⅰ and osteocalcin) were lost partly and expressed non-specific type Ⅲ collagen. Conclusion Abnormal function and degeneration of osteoblasts may play an important role in the pathogenesis of osteoporosis.