牵引力介导MC3T3-E1细胞microRNA的差异表达

Differential expression of microRNA in MC3T3-E1 cells mediated by mechanical strain

目的探讨周期性牵引力作用下小鼠成骨前体细胞microRNA的表达谱,寻找与TGF-β信号通路相关的差异microRNA。方法体外培养MC3T3-E1细胞。以正常培养细胞为对照,应力加载组细胞加载12%拉伸应变力3 h,利用microRNA基因芯片技术初步筛选出牵张应力作用下MC3T3-E1细胞差异表达的microRNA,然后采用实时荧光定量PCR技术对与TGF-β信号通路相关的差异表达microRNAs进行验证,生物信息学预测可能受其调控的靶基因。结果与对照组相比,应力加载组有41个microRNAs表达差异(P值均小于0.05且差异倍数均大于1.5倍),其中20个表达上调,21个表达下调。实时荧光定量PCR结果显示:相比于对照组,应力加载组中miR-132-3p的表达水平升高,与芯片结果一致且存在统计学差异(P<0.05)。经软件分析,miR-132-3p的靶基因可能为Smad2。结论周期性牵引力作用下成骨细胞microRNA表达谱发生改变,这些差异表达的microRNAs可能通过影响TGF-β信号通路或其相关信号分子来影响成骨细胞的生物学功能。

Objective To investigate the profile of microRNA expression in mouse pre-osteoblast cell under cyclic stretch and to find the differences in microRNA which are related to TGF-β signaling pathway. Methods MC3T3-E1 cells were cultured in vitro. Normal cells were considered as controls and loading group cells loaded with 12% elongation for 3 hours, the differential expressed microRNA of MC3T3-E1 cell under mechanical strain conditions was screened by microRNA Microarray Technology, and then the Quantitative Re- al-time PCR was used to verify the differences associated with TGF-β signaling pathway, and bioinformatics was used to predict the tar- get genes that may be regulated by it. Results Compared with the control group, 41 differentially expressed microRNAs were filtered in loading group, in which 20 were up-regulated and 21 were down-regulated（ P values were less than 0.05 and the difference multiples were more than 1.5 times）. The Quantitative Real-time PCR results showed that compared to the normal culture group, the expression level of miR-132-3p increased in loading group, consistent with the microarray results and there was significant difference （P〈0.05）. After software analysis, miR-132-3p target gene may be Smad2. Conclusion The expression profile of microRNA in osteoblast is sig- nificantly affected by cyclic stretch stress, these differences may influence the biological function of osteoblast by TGF-β signaling path- way or its related signal molecules.