低强度脉冲超声刺激对人类牙周膜细胞BMP-2表达效应的研究

目的：探讨一定强度的LIPUS对H-PDLCs进行辐照后,细胞内BMP-2的表达变化,对LIPUS诱导牙周成骨效应进行初步评估。方法：体外培养H-PDLCs,LIPUS（90mW/cm2,20min/天）连续处理1周,分别于处理1、3、5、7天后收集标本,同期培养的未接受任何处理的H-PDLCs为对照组。实时定量PCR检测各时间点细胞内BMP-2基因表达变化,2^（-△△CT）法分析基因相对表达变化量,对△CT值组间差异进行方差分析。结果：实时定量PCR显示LIPUS处理后H-PDLCs内BMP-2表达逐渐增强,于第3天达高峰,第5天逐渐减弱,但表达仍高于同期未处理组,到第7天下降到接近同期未处理组水平。尤其是,LIPUS处理3天后较同期对照组BMP-2基因表达增加6.07倍;5天后较同期对照组BMP-2基因表达增加2.30倍,△CT值组间均具有统计学差异（P〈0.05）。结论：本研究发现LIPUS处理可有效诱导H-PDLCs的BMP-2表达增强,随时间变化呈现一定的规律性。这表明LIPUS具有潜在的促进H-PDLCs成骨分化效应。

Effects of Low Intensity Pulsed Ultrasound on the expression of BMP-2 in human periodontal ligament cells

Objective To investigate the expression of BMP-2 in human periodontal ligament cells（H-PDLCs） after a certain intensity of Low Intensity Pulsed Ultrasound（LIPUS）,and to evaluate the osteogenic effect of LIPUS on the periodontium.Methods H-PDLCs were cultured in vitro,and stimulated with LIPUS（90 mW/cm2,20min/day） for one week.The samples were collected on the first day,third day,fifth day,and seventh day after the role of LIPUS.The H-PDLCs were cultured in the same conditions but without LIPUS management as control group.The expression of BMP-2 in H-PDLCs at each time point were detected by Real-time PCR,and the relative gene expression were analyzed by the method of 2^（-△△CT）.Statistical analysis was performed by analysis of variance（ANOVA）.Results Expression of BMP-2 increased in LIPUS treatment group,reach the peak on day 3,then decreased on day 5,and then dropped to the original level on day 7.Analysis showed that the expression of BMP-2 gene expression increased to 6.07 times on the third day after the role of low Intensity Pulsed Ultrasound,and the expression of BMP-2 gene expression increased to 2.30 times on the fifth day.The differences of △CT between two groups were statistically significant（P0.05）.Conclusion This study demonstrates that LIPUS could induce the expression of BMP-2,showing a certain degree of regularity over time.It indicates that LIPUS can promote osteogenic differentiation of H-PDLCs.