微振动环境调控小鼠骨髓间充质干细胞的早期力学适应性及成骨分化

Early stage mechanical adaptability and osteogenic differentiation of mouse bone marrow derived mesenchymal stem cell under micro-vibration stimulation environment

本研究考察微振动刺激(MVS)对小鼠骨髓来源间充质干细胞(M-BMSCs)的早期力学适应性及成骨分化的调控作用。在体外给予M-BMSCs微振动刺激,检测细胞增殖及碱性磷酸酶(ALP)表达,荧光染色观察细胞凋亡与细胞骨架,流式检测细胞凋亡,通过RT-PCR检测早期成骨相关基因runt相关转录因子2(Runx2)、Ⅰ型胶原(Col-Ⅰ)、ALP表达,Western blotting检测细胞外调节蛋白激酶1/2(ERK1/2)磷酸水平。研究结果显示,微振动刺激诱导了细胞早期凋亡(受力1天后),但周期性受力3天后细胞的凋亡现象明显减少,而细胞的增殖活性并未受到明显影响;同时,微振动刺激促进了细胞骨架F-actin蛋白、ALP合成和ERK1/2的磷酸化,并上调了Runx2、Col-Ⅰ、ALP的基因表达。研究结果表明微振动刺激能对M-BMSCs的细胞活性和结构产生早期适应性改变与调节,从而促进了细胞的早期成骨分化。

This study investigated the early mechanical adaptability and osteogenic differentiation of mouse bone marrow mesenchymal stem cells(M-BMSCs)under micro-vibration stimulation(MVS).M-BMSCs were stimulated by MVS in vitro,cell proliferation,alkaline phosphatase(ALP)activity assay,and cytoskeleton were measured,and cell apoptosis was observed by flow cytometry.Early osteoblast-associated genes,runt-related transcription factor 2(Runx2),CollagenⅠ(Col-Ⅰ)and ALP,were observed by RT-PCR and the activation of extracellular regulated protein kinases 1/2(ERK1/2)was determined by Western blotting.The results showed that MVS had no significant effect on the proliferation of M-BMSCs.The early apoptosis was induced by mechanical stimulation(for one day),but the apoptosis was decreased after cyclic stimulation for 3 days.At the same time,MVS significantly accelerated the expression of F-actin protein in cytoskeleton,the synthesis of ALP and the ERK1/2 pathway,also up-regulated the expressions of Runx2,Col-Ⅰand ALP genes.This study indicates that MVS could regulate cellular activity,alter early adaptive structure and finally promote the early osteogenic differentiation of M-BMSCs.