张应力作用下小鼠脂肪间充质干细胞骨向分化过程中成骨相关微小RNA表达模式

Osteogenesis-related microRNA expression pattern analysis during osteogenic differentiation of murine adipose-derived mesenchymal stem cells under tensile stress

目的探讨张应力下小鼠脂肪间充质干细胞(ADSCs)骨向分化中成骨相关微小RNA(miRNA)的表达模式。方法将第3代小鼠ADSCs分为实验组和对照组,实验组应用四点弯曲加力仪对ADSCs进行加力,对照组不加力;采用实时定量聚合酶链反应检测成骨细胞转录因子2(Runx2)、碱性磷酸酶(ALP)、骨钙素(OCN)及Ⅰ型胶原蛋白(Col1)mRNA在不同时间点的表达;采用基因芯片技术筛选成骨相关miRNA,并检测其在加力进程中的相对表达强度。结果实验组成骨相关基因mRNA水平相对较高;共筛选出5个上调、6个下调的miRNA;张应力刺激的第3天所有miRNA即出现差异性变化,多数miRNA在加力过程中呈持续上调或下调趋势,在第5天时差异性最显著。结论张应力可促进ADSCs骨向分化,成骨相关的miRNA在这一过程中起重要作用。

Objective To investigate the osteogenesis-related microRNA(miRNA)expression pattern during osteogenic differentiation of murine adipose-derived mesenchymal stem cells(ADSCs)under tensile stress.Methods ADSCs of the third generation of mice were divided into two groups,the experiment and the control group.The experiment group cells were subjected to a cyclic uniaxial tensile strain generated by a four-point bending apparatus,while the control group cells were without tension treatment.QRT-PCR(quantitative real-time PCR)was used to detect the expression of OCN(Osteocalcin),ALP(alkaline phosphatase),Col1(type I collagen)and Runx2(runt-related transcription factor 2)mRNA at different time points.Microarray was used to screen osteogenesis-related miRNA,and the relative expression intensity of miRNAs was detected during the application of tension.Results The mRNA levels of osteogenic genes in the experimental group were relatively high.Five up-regulated and 6 down-regulated miRNAs were screened out.On the third day of tensile stress stimulation,all miRNAs showed different changes,and most miRNAs showed a continuous up-regulation or down-regulation trend in the process of augmentation,with the most significant difference on the fifth day.Conclusion Tensile stress can induce the osteogenic differentiation of the ADSCs,which may be attributed to the osteogenesis-related miRNA.