牵张力作用下人牙髓细胞HIF-1α和VEGF的表达

Expression of HIF-1α and VEGF in human dental pulp cells under mechanical stretch

目的:研究牵张力作用下人牙髓细胞HIF-1α和VEGF基因的表达变化,探讨HIF-1α和VEGF与正畸牙髓组织维持内环境稳定的关系。方法:通过细胞牵张应力加载系统,对细胞施加频率为1.0 Hz、大小为15%形变率的牵张应力,分别加力6 h、12 h、24 h、48 h和72 h。实时定量PCR检测不同时间点HIF-1α和VEGF mRNA的表达变化。采用SPSS12.0软件包对数据进行统计学分析。结果:未加力前,HIF-1αmRNA表达极其微弱;加力6 h时,表达开始升高(P<0.05);持续增加至24 h时,表达最显著(P<0.05);加力48 h时,表达缓慢下降(P<0.01);至加力72 h时,表达下降至未加力前(P>0.05)。未加力前,VEGF mRNA表达微弱,加力6 h表达开始升高,但无显著差异(P>0.05);加力12 h时,VEGF mRNA表达开始明显增强(P<0.05),持续增加至72 h加力结束时(P<0.05)。结论:牵张力可诱导人牙髓细胞HIF-1α和VEGF mRNA的表达变化,两者可能在维持正畸受力后牙髓内环境稳定中发挥重要作用。

PURPOSE： To examine the expression of HIF-1α and VEGF after application of mechanical stretch on human dental pulp cells（HDPCs）,and to investigate the role of them in maintaining homeostasis of dental pulp during orthodontic movement.METHODS： HDPCs were subjected to 15% elongation by 1.0 Hz stretching frequency for 6,12, 24,48 and 72 h.The expression of HIF-1α and VEGF mRNA was measured by real-time polymerase chain reaction（PCR）.SPSS12.0 software package was applied for statistical analysis.RESULTS： At the initial time point,HIF-1α mRNA had a weak expression.The mRNA level of HIF-1α increased gradually and then decreased towards its prepressure levels.The mRNA level of VEGF was upregulated in a time-dependent manner.CONCLUSIONS： The mRNA expression of HIF-1α and VEGF was enhanced by mechanical stress in HDPCs,which indicates that HIF-1α and VEGF may play an important role in retaining homeostasis of dental pulp during orthodontic movement.