microRNA-214-3p在周期性张应变诱导内皮祖细胞分化和增殖中的作用

目的探讨microRNA-214-3p(miR-214-3p)在周期性张应变诱导内皮祖细胞(endothelial progenitor cells, EPCs)分化和增殖中的作用。方法采用FX-5000T细胞周期性张应变加载装置对EPCs施加生理水平的周期性张应变(5%幅度、1.25 Hz频率),加载时间24 h。应用miRNAs芯片筛选周期性张应变调控下差异表达的miRNAs,并挑选miR-214-3p进行深入研究。实时荧光定量PCR方法检测EPCs内平滑肌细胞(vascular smooth muscle cells, VSMCs)相标志分子的表达,BrdU结合酶联免疫吸附ELISA法检测EPCs增殖功能。之后,使用miR-214-3p抑制剂抑制miR-214-3p的表达,检测EPC内VSMC相标志分子表达及EPCs增殖。结果周期性张应变显著抑制miR-214-3p表达,并抑制EPCs向VSMC相分化,同时显著促进EPCs增殖。在静态条件下,使用miR-214-3p抑制剂干扰miR-214-3p的表达,miR-214-3p水平下降同样会抑制EPCs向VSMC相分化,并且诱导EPCs增殖能力显著上升。结论生理水平的周期性张应变能够抑制EPCs内miR-214-3p表达,从而抑制EPCs向VSMC相分化,并且促进EPCs增殖。研究结果为血管损伤的治疗提供新的治疗靶点。

The Role of MicroRNA-214-3p in Differentiation and Proliferation of Endothelial Progenitor Cells in Response to Cyclic Stretch

Objective To investigate the role of microRNA-214-3p (miR-214-3p) in differentiation and proliferation of endothelial progenitor cells (EPCs) induced by cyclic stretch. Methods EPCs were exposed to cyclic stretch at physiological level (with the magnitude of 5%, at a constant frequency of 1.25 Hz) for 24 h by FX-5000T Strain Unit. miRNAs array was performed to identify the expression profiling of miRNAs. Real-time PCR was used to examine the expression levels of miRs. The expression of vascular smooth muscle cells (VSMCs) markers in EPCs was detected by real-time PCR. EPC proliferation was detected by BrdU ELISA assay. After EPCs were transfected with miR-214-3p inhibitor (IN) to knockdown expression of miR-214-3p, the level of VSMC markers expression and EPC proliferation was detected. Results Cyclic stretch significantly decreased miR-214-3p expression, depressed EPC differentiation toward VSMCs, and increased EPCs proliferation. Similarly, transfection with the miR-214-3p inhibitor led to the decreased expression of VSMC markers under static station. Meanwhile, miR-214-3p down-regulation promoted EPC proliferation significantly. Conclusions Physiological cyclic stretch could down-regulate the expression of miR-214-3p in EPCs, depress EPC differentiation towards VSMC and promote EPC proliferation eventually. Therefore, the research findings provide a potential therapeutic strategy for treating vessel injuries.