【摘要】 目的:研究人牙周膜细胞在离心力作用下转录活化因子4(ATF4)mRNA和蛋白的表达变化。方法:组织块法培养人牙周膜细胞,对其施加10、30、60、90、120和240min离心力(167g)。半定量RT-PCR及Western印迹检测ATF4mRNA和蛋白在不同加力时间点的表达变化。采用SPSS11.5统计软件包,对数据进行单因素方差分析。结果:正常人牙周膜细胞有ATF4mRNA表达,但几乎没有ATF4蛋白表达;加力10min,mRNA及蛋白表达均增强(P>0.05);加力30min,mRNA表达达到高峰(P<0.01);加力60min,蛋白表达达到高峰(P<0.01);加力90min,mRNA及蛋白表达下降,但仍高于加力前水平(P<0.01);加力120min,mRNA及蛋白均恢复到未加力水平(P>0.05)。结论:离心力可诱导人牙周膜细胞ATF4mRNA及蛋白表达短暂性升高;ATF4参与了正畸力作用下的力学信号转导过程。更多还原

【Abstract】 PURPOSE: This study was designed to examine the changes of mRNA and protein levels of activating transcription factor-4 after centrifugal force stimulation in cultured human periodontal ligament (PDL)cells. METHODS: Human PDL cells were cultured by sequential digestio, and then stimulated by centrifugal force (167g) for 10, 30, 60, 90, 120 and 240 minutes. The changes of mRNA and protein levels of ATF4 were analyzed by semi-quantitative RT-PCR and Western blotting. The data was analyzed with SPSS11.5 software package for ANOVA. RESULTS: Unstimulated human PDL cells exhibit an ATF4 mRNA expression, but very low level of protein; Immediately 10 minutes after force application, the mRNA and protein levels of ATF4 increased(P>0.05); at 30-minute,the mRNA level increased significantly to a peak level(P<0.01), at 60-minute, the protein level increased significantly to a peak level(P<0.01); at 90-minute, mRNA and protein levels decreased, but still higher than the control(P<0.01); after 120 minutes, mRNA and protein levels decreased to control levels(P>0.05). CONCLUSION: Centrifugal force stimulates ATF4 gene expression within a narrow time frame: a temporary increase of ATF4 expression and a fast downregulation back to its preloading level. This study demonstrates that ATF4 may play a critical role in orthodontic alveolar bone remodeling.更多还原