流体剪切应力对模拟失重条件下MG-63成骨样细胞Cbfα1表达的影响

Influence of Fluid Shear Stress on Expression of Cbfα1 in MG-63 Cells Cultured under Simulated Microgravity Condition

目的观察模拟失重条件下培养的人骨肉瘤MG-153成骨样细胞受流体剪切应力（FSS）作用后核心结合因子α1（Cbfα1）表达的改变，初步探讨失重情况下骨质减少的可能机制。方法MG-153成骨样细胞传代于25ml培养瓶中，培养24h后细胞被随机分为模拟失重组和1G组（每组又下设立FSS作用组和无FSS作用组）。48h后，将细胞置于流室系统中进行刺激实验。FSS强度设为0．5Pa，作用时间分别为15、30和60min。其后提取细胞总RNA，进行反转录PCR，检测细胞内Cbfα1 mRNA的表达，并计算与内参照GAPDHmRNA的比值。同时提取细胞总蛋白，Western Blotting检测Cbfα1蛋白的表达。结果和无FSS作用组相比，FSS作用组的Cbfel的表达在30min和60min均显著增强，且在一定的时间范围内（15～60min）Cbfα1的表达水平随着作用时间的延长而增加。和1G组相比。模拟失重组的Cbfα1表达水平降低，在30min、60min时有显著的统计学意义。结论FSS可以促进MG-63成骨样细胞内Cbfα1的表达，模拟失重可显著抑制FSS对MG-63成骨样细胞内Cbfα1表达的诱导作用。

Objective To clarify the effect of flow shear stress （FSS） on the expression of core binding factor α1 （Cbfα1） in human osteosarcoma MG-63 cells cultured in simulated microgravity environments and the mechanism of osteopenia induced by weightlessness. Methods MG-63 cells were divided into two groups （1 G group and simulated microgravity group） after cultured for 24 h. One group of cells were rotated 48 h to simulate weightlessness environment while the other group of cells were kept at l G as control. Then the cells were treated with 0.5 Pa FSS in a flow chamber for 15, 30, 60 rain, respectively. Total RNA in the cells was isolated. RT-PCR analysis were made to examine the gene expression of Cbfα1. Each value was normalized against that of glyceraldehydes phosphate dehydrogenase （GAPDH）. Moreover, the protein expression of Cbfα1 was detected by Western blotting. Results Compared with control group, Cbfα1 expression increased remarkably from 30 rain to 60 rain with the treatment of FSS （P〈0.01 ）. Compared with 1 G group, the expression of Cbfα1 was down-regulated in simulated microgravity group. The differences were significant at 30 and 60 min. Conclusion FSS can significantly increase the expression of Cbfα1 in MG- 63 cells. The inducing effect of FSS on the expression of Cbfα1 is affected by the simulated microgravity environment.