论文部分内容阅读
研究50 Hz不同强度正弦交变电磁场(SEMFs)对体外培养大鼠骨髓间充质干细胞(rBMSCs)增殖与成骨性分化的影响,筛选出最佳磁场强度参数。采用贴壁筛选法培养原代rBMSCs,每天在频率为50 Hz,强度分别为0、1.4、1.6、1.8、2.0、2.2 mT的磁场环境中处理30 min。MTT法检测细胞增殖情况;于处理后的第3、6、9、12 d分别测定细胞碱性磷酸酶活性、钙盐沉积量、钙化结节数以及Ⅰ型胶原表达量,并比较各组间差异;于处理后6、12、24、48 h分别提取细胞总RNA,用RT Real-Time PCR法检测成骨性分化相关基因Osterix和IGF-1表达情况。实验结果显示电磁场干预组的细胞增殖率均低于对照组;但1.4~2.2 mT区间的磁场具有促成骨效应,以1.8 mT促进rBMSCs的成骨性分化更明显,表现在该组的碱性磷酸酶活性、钙盐沉积量、钙化结节数、Ⅰ型胶原表达量以及成骨性分化基因的表达量最高,亦显著高于对照组(P<0.05)。由此可以认为频率为50 Hz、强度范围在1.4~2.2 mT内的SEMFs抑制rBMSCs的增殖;但促进其成骨性分化,以1.8 mT效果最为明显。
The effects of 50 Hz sinusoidal alternating electromagnetic fields (SEMFs) of different intensities on the proliferation and osteogenic differentiation of cultured rat bone marrow mesenchymal stem cells (rBMSCs) were studied. The optimal magnetic field strength parameters were screened out. The primary rBMSCs were cultured by adherence screening method and treated for 30 min every day in the magnetic field with frequency of 50 Hz and intensities of 0, 1.4, 1.6, 1.8, 2.0 and 2.2 mT. The cell proliferation was detected by MTT assay. The alkaline phosphatase activity, calcium deposition, calcified nodules and collagen type Ⅰ expression were measured on the 3rd, 6th, 9th and 12th day after treatment. The total RNA was extracted at 6, 12, 24 and 48 h after treatment, and the expression of osteogenic differentiation-related genes Osterix and IGF-1 were detected by RT Real-Time PCR. The experimental results showed that the cell proliferation rate in the electromagnetic field intervention group was lower than that in the control group; however, the magnetic field in the range of 1.4-2.2 mT contributed to the osteogenesis effect. The promotion of osteogenic differentiation of rBMSCs at 1.8 mT was more obvious, Enzyme activity, calcium deposition, calcified nodules, collagen type I expression and osteogenic differentiation gene expression were also significantly higher than those in the control group (P <0.05). Thus, SEMFs with a frequency of 50 Hz and an intensity range of 1.4-2.2 mT could be considered to inhibit the proliferation of rBMSCs; however, the promotion of their osteogenic differentiation was most pronounced at 1.8 mT.