频率对拉伸应变诱导成骨细胞凋亡的影响

发布时间：2018-12-15 01:01

【摘要】：目的考察频率对拉伸应变诱导成骨细胞凋亡的影响。方法采用Flexcell力学加载系统对小鼠前成骨细胞MC3T3-E1施加1%双轴拉伸应变刺激,频率分别为1、2、3、4、5 Hz,每天加载1 h,间歇性拉伸8 d;通过测定乳酸脱氢酶(LDH)活性检测细胞死亡率;采用Annexin V-FITC/PI流式细胞术观察细胞凋亡情况;实时PCR检测细胞凋亡标志基因caspase-3、-9以及Bcl-2、Bax基因水平;Western blotting检测caspase-3、-9蛋白表达。结果不同加载频率对成骨细胞LDH活性无影响;不同频率下流式细胞术总体凋亡率无显著性差异,但是2 Hz频率可诱导成骨细胞早期凋亡。2 Hz拉伸应变可明显上调caspase-3、-9基因和蛋白表达,上调Bax/Bcl2蛋白比值。结论 1%双轴拉伸应变刺激下1~5 Hz频率不能引起成骨细胞凋亡和死亡,但2 Hz频率可诱导成骨细胞早期凋亡,且通过上调Bax/Bcl-2表达实现的。
[Abstract]:Objective to investigate the effect of frequency on the apoptosis of osteoblasts induced by tensile strain. Methods Flexcell mechanical loading system was used to induce 1% biaxial tensile strain on mouse preosteoblast MC3T3-E1. The frequency of the strain was 1h / d for 1 h / d and 4 Hz, / d for intermittent stretching. The cell death rate was detected by measuring the activity of lactate dehydrogenase (LDH), the apoptosis was observed by Annexin V-FITC/PI flow cytometry, and the levels of caspase-3,-9 and Bcl-2,Bax genes were detected by real-time PCR. The expression of caspase-3,-9 protein was detected by Western blotting. Results the LDH activity of osteoblasts was not affected by different loading frequency. There was no significant difference in the overall apoptosis rate of osteoblasts by flow cytometry at different frequencies, but 2 Hz frequency could induce early apoptosis of osteoblasts, 2 Hz stretch strain could obviously up-regulate the expression of caspase-3,-9 gene and protein, and up-regulate the ratio of Bax/Bcl2 protein. Conclusion 1% biaxial tensile strain can not induce apoptosis and death of osteoblasts at 1 Hz frequency, but 2 Hz frequency can induce early apoptosis of osteoblasts, which can be achieved by upregulating the expression of Bax/Bcl-2.
【作者单位】：武警后勤学院;武警陕西总队铜川支队卫生队;
【基金】：国家自然科学基金项目(11302262)
【分类号】：R82

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