正弦波电磁场对鼠骨骺干细胞分化的生物学影响

目的 研究50Hz正弦波电磁场对大鼠骨骺干细胞分化的生物学影响。方法 取生长良好的第4代骨骺干细胞，随机分为实验组和对照组，实验组采用50Hz正弦波电磁场间断刺激。分别绘制2组细胞生长曲线，MTT法测定细胞增殖活性，流式细胞仪检测细胞凋亡情况，Western Blot法检测细胞甲状旁腺激素相关蛋白（PTHrp）的表达，并进行定量分析。结果 曝磁早期细胞增殖活性的改变不明显，正弦波电磁场刺激4d和6d能明显促进细胞的增殖，2组OD值比较，差异有统计学意义（P〈0.05）。与对照组比较，实验组骨骺干细胞的早期凋亡率、晚期凋亡率和总凋亡率均明显降低（P〈0．05）．PTHrp蛋白的表达增强。结论 适当参数的工频正弦波电磁场能促进骨骺干细胞PTHrp蛋白的表达，从而调节其增殖能力，增强分化稳定性，抑制细胞凋亡。

The biological effects of sinusoidal electromagnetic fields on proliferation and differentiation of precartilaginous stem cells in rats

Objective To study the biological effects of sinusoidal electromagnetic fields ( EMFs) on proliferation and differentiation of precartilaginous stem cells (PSCs) in rats in vitro. Methods The rodent PSCs were isolated and cultured in vitro. The fourth passage PSCs were randomly divided into an experiment group and a control group, and stimulated with sinusoidal EMFs under the same conditions. Cell proliferation was measured at different time points by using of MTT, and the growth curve was obtained. The apoptosis was analyzed by the use of flow cytometer and the expression of parathyroid hormone-related peptide(PTHrp) was detected with Western Blot. Results The cellular differentiation was inhibited with sinusoidal EMFs of 50 Hz frequency and 1mT intensity, while cell proliferation was promoted at 4 d after stimulation (P<0.05). Compared with those in the control group, the early and total rates of apoptosis in experiment group were obviously decreased, but the expression of PTHrp protein was significantly increased. Conclusion Sinusoidal EMFs might regulate proliferation and differentiation, enhance the stability of PSCs and inhibit apoptosis by mediating the expression of PTHrp protein.