不同浓度地塞米松对成骨样细胞OS-732细胞凋亡和细胞周期的影响

Effect of Dexamethasone at Different Concentrations on OS-732 Cell Apoptosis and Cell Cycle

【目的】通过不同浓度地塞米松(DMX)体外培养成骨样细胞OS-732,观察糖皮质激素对其凋亡和细胞周期的影响。【方法】选择细胞密度为1×105/mL且贴壁生长良好的OS-732细胞,设不同浓度给药组(即DMX1、DMX2、DMX3组,分别加入浓度为10-7、10-8、10-9mmol/L的DMX与RPMI-1640培养)和空白对照组(仅加入RPMI-1640培养),于24h和48h两个时间点检测细胞各项DNA含量及细胞周期。【结果】在24h时间点,DMX1组G2/M期DNA含量显著增加(P<0.01);DMX2组各期与空白对照组比较,差异无显著性意义(P>0.05);DMX3组G0/G1期DNA含量显著减少(P<0.05)。空白对照组和各给药组均出现了凋亡峰,DMX1组细胞凋亡率显著下降(P<0.05),DMX3组细胞凋亡率显著上升(P<0.01)。在48h时间点,DMX1组G2/M期DNA含量显著增加(P<0.05),细胞凋亡率显著下降(P<0.05);DMX2组和DMX3组细胞凋亡率显著上升(P<0.01),S期DNA含量显著减少(P<0.01)。【结论】糖皮质激素使用的时间和量对成骨样细胞的作用不同,小剂量糖皮质激素(生理需要量)对成骨样细胞的增殖具有促进作用,高剂量糖皮质激素(超过生理需要量)对成骨样细胞的增殖和分化具有抑制作用。

Objective To observe the effect of glucocorticoid on osteoblast-like cell apoptosis and the cell cycle. Methods Osteoblast-like cells OS-732 at the density of 1 × 10^5/mL were cultured in vitro with dexamethasone （DMX） at the concentrations of 10^-7, 10^-8 and 10^-9 mmol/L. The apoptosis of OS-732 was detected by flow cytometry after the culturing for 24 and 48 hours, and then DNA content was detected and the cell cycle was analysed. Results At the time point of the 24^th hour, DNA content at G2/M phase of OS-732 cell cycle was increased obviously in DMX1 （10^-7 mmol/L） group （P 〈 0.01 ）. No significant difference of DNA content at different cell cycle phases was found between DMX2 （ 10^-8 mmoL/L） group and the control group. The DNA content was decreased at G0/G1 phase in DMX3 （10^-9 mmoL/L） group （P 〈 0.05）. There presented apoptotic peak in the blank control group and DMX groups, and the apoptotic rate was decreased obviously in DMX1 group （P 〈0. 05） and increased in DMX3 group （P 〈0. 01 ）. At the time point of the 48^th hour, DNA content at G2/M phase of OS-732 cell cycle was increased obviously in DMX1 group （ P 〈 0.05 ）, the apoptotic rate decreased in DMX1 group （ P 〈 0. 05 ） and increased in DMX2 and DMX3 groups （ P 〈 0. 01 ）, DNA content at S phase was reduced in DMX2 and DMX3 groups （P 〈0.01 ）. Conclusion DMX at different medication time and in different dosages can result in different effects on osteoblast-like cells. Small-dosage of glucocorticoid （at the amount of meeting physiological demand ） can promote the proliferation of osteoblast-like cells, and high-dosage of glucocorticoid （over the amount of physiological demand ） can inhibit the proliferation and differentiation of osteoblast-like cells.