目的探究模拟微重力效应对骨细胞Wnt/β-catenin信号通路活性的影响,以阐明微重力导致骨质丢失的发生机制。方法将骨细胞MLO-Y4分为两组:模拟微重力组和静置对照组。细胞旋转培养以模拟微重力效应,利用RT-PCR和Western blot法检测细胞Wnt/β-catenin信号通路相关组分的基因和蛋白表达水平。结果 RT-PCR结果显示,模拟微重力组的Cyclin D1和Lef-1 mRNA水平显著低于对照组(P<0.05),CX43和抑制剂SOST的mRNA水平显著高于对照组(P<0.05),而两组的Wnt3a、Lrp5和β-catenin的mRNA水平无显著性差异。Western blot结果显示,模拟微重力组的β-catenin和Cyclin D1的蛋白表达水平显著低于对照组(P<0.05),Lef-1和抑制剂SOST蛋白质的表达水平显著高于对照组(P<0.05),而两组Wnt3a、Lrp5/6和CX43的蛋白表达水平无显著性差异。结论模拟微重力效应下骨细胞中Wnt/β-catenin信号通路的活性有所下降。 Objective To investigate the effect of simulated microgravity on the activity of Wnt / β-catenin signaling in osteoblasts to elucidate the mechanism of microgravity induced bone loss. Methods The osteoblasts MLO-Y4 were divided into two groups: simulated microgravity group and static control group. The cells were cultured in vitro to simulate the effects of microgravity. The expression of Wnt / β-catenin signaling pathway related genes and proteins were detected by RT-PCR and Western blot. Results RT-PCR results showed that mRNA levels of Cyclin D1 and Lef-1 in simulated microgravity group were significantly lower than those in control group (P <0.05), CX43 and SOST mRNA levels were significantly higher than those in control group (P <0.05) There was no significant difference in mRNA levels of Wnt3a, Lrp5 and β-catenin between the two groups. Western blot results showed that the protein expression levels of β-catenin and Cyclin D1 in simulated microgravity group were significantly lower than those in control group (P <0.05), and the expression levels of Lef-1 and SOST protein were significantly higher than those in control group (P < 0.05). There was no significant difference in the protein expression levels of Wnt3a, Lrp5 / 6 and CX43 between the two groups. Conclusion The activity of Wnt / β-catenin signaling pathway in osteoblasts decreased with simulated microgravity.