模拟失重条件下成骨细胞核基质DNA拓扑异构酶Ⅱ β的改变

Changes of nuclear matrix and DNA Topoisomerase Ⅱ β in osteoblasts under simulated microgravity

目的研究模拟失重条件下DNA拓扑异构酶Ⅱβ蛋白表达与分布位置的改变,从而间接了解细胞核基质结构的改变。方法培养大鼠乳鼠颅骨原代成骨细胞并随机分为模拟失重组与对照组。以回转器建立细胞模拟失重模型,之后间接免疫荧光染色与Western blot法检测两组间细胞中DNA拓扑异构酶Ⅱβ的改变。结果与对照组相比,模拟失重组细胞DNA拓扑异构酶Ⅱβ免疫荧光强度降低且失去原有的均匀分布。Western blot检测发现,与对照组相比模拟失重组细胞DNA拓扑异构酶Ⅱβ表达显著降低(P<0.05)。结论模拟失重可导致成骨细胞DNA拓扑异构酶Ⅱβ表达降低且分布位置不均,提示模拟失重下细胞核基质结构发生改变。

Objective To investigate the position and expression changes of DNA TopoisomeraseⅡβ, and study the structure changes of nuclear matrix indirectly. Methods Rat calvarial osteoblasts were primarily cultured and randomly divided into simulated microgravity group and control group. After culturing in the condition of simulated microgravity created by clinostat rotation for 48 hours, the DNA TopoisomeraseⅡβ were tested by indirect immunofluorescence and western blot. Results Compared with control group, the DNA TopoisomeraseⅡβ fluorescence signal of microgravity group became weak and heterogeneous. Western blot showed that the expression of DNA Topoisomerase Ⅱβ in microgravity group were significantly lower than control group（P〈0.05）. Conclusion Simulated microgravity can decrease the expression and disorganize the distribution of the DNA Topoisomerase Ⅱ β, which suggests that the structure of nuclear matrix is changed in simulated microgravity.