目的　探讨流体剪切应力对大鼠骨髓间充质干细胞（rat bone marrow-derived mesenchymal 　stem cells，rMSCs）中膜型基质金属蛋白酶1（Membrane type-1 matrix metalloproteinase, MT1-MMP）基因表达的影响，为阐明应力诱导rMSCs分化的分子机制提供一些实验依据。　方法　应用平行平板流动腔系统，给rMSCs施加不同大小和不同加载时间的层流剪切应力，用real-time PCR检测MT1-MMP基因mRNA的表达水平。　结果　5, 15, 30 dynes/cm2剪切应力均能刺激rMSCs的MT1-MMP mRNA表达，且其作用呈时间依赖和强度依赖。p38抑制剂（SB202190）可以明显抑制这种作用, 而PI3K抑制剂（wortmannin）却增强了这种效果。　结论　流体剪切应力可诱导rMSCs的MT1-MMP基因表达，其表达量与刺激时间和剪切应力的强度密切相关，这种作用可能通过p38MAPK和PI3K/Akt信号通路。

Objective　To investigate the effect of laminar shear stress on the expression of membrane type-1 matrix metalloproteinase（MT1-MMP）in rat bone marrow-derived mesenchymal stem cells (rMSCs). Methods　rMSCs were isolated from SD rat lower extremities and loaded by laminar shear stress with the parallel-plate flow chamber system, then the expression of MT1-MMP mRNA of rMSCs was examined by real-time PCR.　Results　Shear stress with different magnitude of 5, 15, 30 dynes/cm2 all induced MT1-MMP mRNA expression, especially high shear stress, 30 dynes/cm2, which was time-dependent. The expression of MT1-MMP mRNA was inhibited by SB202190, an inhibitor of p38, but enhanced by wortmannin, an inhibitor of PI3K/Akt.　Conclusion　Shear stress can activate the expression of MT1-MMP. The amount of MT1-MMP expression is closely related to stimulating time and the strengths of shear stress, and p38MAPK and PI3K/Akt signal pathway may play a critical role during the process.