高糖及高糖波动对MG63细胞株氧化应激的影响

Effects of high glucose and high glucose fluctuation on oxidative stress by MG63 cells

目的研究波动性葡萄糖和恒定高葡萄糖对MG63细胞增殖、细胞周期及氧化应激的影响,探讨波动性葡萄糖造成糖尿病性骨质疏松症可能的发病机制。方法体外培养的人成骨肉瘤MG63细胞株,随机分为正常对照NG组(葡萄糖浓度为5.5mmol/L),恒定高葡萄糖HG组(含葡萄糖33.3mmol/L),波动性葡萄糖FG组(5.5/33.3mmol/L),共作用24h。MTT比色分析法测定细胞增殖,流式细胞仪检测细胞周期及凋亡率。取MG63细胞培养上清液,以黄嘌呤氧化酶法测定超氧化物歧化酶(SOD)活性,以硫代巴比妥酸为底物检测丙二醛(MDA)含量。结果 (1)高糖及高糖波动可抑制MG63细胞的增殖,与高糖组相比,高糖波动组的抑制效应更加明显。(2)高糖及高糖波动可阻滞MG63细胞周期,使G1期细胞比例增加,S期比例减少,诱导细胞凋亡。高糖波动组作用更加明显。(3)高糖作用下MG63细胞SOD活性降低(P<0.05),MDA水平升高(P<0.05),高糖波动组更加明显。结论波动性葡萄糖可加重高糖环境下MG63细胞的氧化应激状态,抑制成骨细胞增殖,阻滞其细胞周期,诱导细胞凋亡。此可能是糖尿病性骨质疏松症的一个重要的发病机制。

Objective To observe the effects of glucose and high glucose fluctuation on proliferation, cell cycle, apoptosis, and oxidative stress by MG63 ceils, and to study the role of non-physiological concentration of glucose in the pathogenesis of diabetic osteoporosis. Methods MG63 cells were incubated for 2dh in the presence of 5.5 mmol/L glucose （NG） , 33.3mmol/L glucose （HG） , and high glucose （5.5/33.3mmol/L） fluctuation （FG）, respectively. The proliferation of MG63 ceils was examined with MTT colorimetric analysis. The cell cycle and apoptotic rate of the cells were determined with flow cytometry. The activity of SOD in the supernatant was measured with xanthine oxidase method and the content of MDA was detected with thiobarbituric acid substrate. Results 1 ） Both high glucose and high glucose fluctuation inhibited MG63 cell proliferation, and the effect in high glucose fluctuation group was significantly higher than in high glucose group （ P 〈 0.05 ）. 2） Both high glucose and high glucose fluctuation blocked cell cycle, increased the percentage of G1 phase, decreased the percentage of S phase, and induced apoptosis. The effect in high glucose fluctuation group was obviously stronger than that in high glucose group （P 〈 0. 05）. 3 ） High glucose decreased the activity of SOD （P 〈 O. 05） and increased the content of MDA （P 〈 0. 05 ）. Compared with those in HG group, the activity of SOD decreased and the content of MDA increased significantly in high glucose fluctuation group. Conclusion High glucose fluctuation not only inhibits the proliferation but also blocks cell cycle, induces apoptosis, and aggravates oxidative stress in MG63 cells, which may be one of the key pathogenic factors in diabetic osteoporosis.