机械牵张对人成骨细胞ALP活性及I型胶原表达的影响

EFFECTS OF MECHANICAL STRAIN ON ALP ACTIVITY AND COLLAGEN I EXPRESSION IN HUMAN OSTEOBLASTS

目的 观察机械张力对成骨细胞碱性磷酸酶 (ALP)活性和I型胶原基因表达的影响。方法 通过Flexercell细胞体外拉伸力学装置对人成骨细胞MG 6 3进行牵张加载实验 ,用生化方法和RT PCR反应检测细胞受张力刺激 6、12、2 4和 4 8h后的ALP活性和I型胶原mRNA的表达变化。结果 机械张力能明显增强MG 6 3细胞的ALP活性。I型胶原mRNA的表达在张力作用后 6～ 12h减弱 ,2 4h后表达升高 ,4 8h最高。结论 机械张力不仅能促进成骨细胞ALP的分泌活性 ,而且还能对成骨细胞胶原合成产生影响。

Objective To study the changes in ALP activity and collagen I expression in osteoblasts after mechanical strain stimulation. Methods MG 63 human osteoblasts were cultured, and exposed to mechanical strain using Flexercell Stretching Unit with different stimulation times. ALP activity and collagen I mRNA expression were detected by assay kit and RT PCR reaction. Results ALP activity was increased significantly after mechanical stimulation. The expression of collagen I was decreased in the period of 6 to 12 h, but increased during 24 to 48 h in strained cells. Conclusion This study suggest that mechanical strain may not only increased the ALP activity, but also alter the mRNA expression of collagen I in human osteoblasts.