机械拉伸对成骨细胞增殖及IGF-1 mRNA表达的影响

应用体外周期性机械拉伸装置对大鼠成骨细胞施加拉伸刺激。研究了应变15％,频率20次／min的拉伸刺激下不同加载时间对成骨细胞增殖及IGF-1 mRNA表达的影响。发现在受载12 h时,细胞相对增殖指数最大,随受载时间的增加而逐渐趋向于1,同时IGF-1 mRNA表达显著增加。说明成骨细胞对周期性机械拉伸刺激的响应,可能是通过增强成骨细胞IGF-1的自分泌作用来发挥其促增殖的生物学效应。并且受载的成骨细胞经过自身调控后,逐渐适应于新的力学环境,保持一种新的平衡状态。

Effects of Mechanical Strain on the Proliferation and Expression of IGF-1 mRNA in Rat Osteoblasts

With the use of a cyclic strain unit, the proliferation and gene expression of IGF-1 in the rat osteoblasts that underwent mechanical strain were studied. The cells were subjected to 15% elongation at frequency 20 cycles/min for different loading time. Under the action of different loading time, the relative proliferation index of the rat osteoblasts was the biggest of all when loading time was 12h; during the course, the expression of IGF-1 mRNA increased significantly, and then gradually tended toward 1 with the increase of the loading time. These results demonstrate that osteoblasts respond to the mechanical forces which may regulate the activities of osteoblasts indirectly by promoting the autocrine effect of IGF-1. Loaded osteoblasts can adjust and adapt themselves to new mechanical stimulation, and hence maintain a new state of equilibrium.