【摘要】 目的探讨生理范围内的流动切应力作用于骨髓间充质干细胞(MSCs)后,其定向内皮诱导所得细胞的组织纤溶酶原激活物(t-PA)信使核糖核酸(mRNA)表达水平的变化。方法体外培养大鼠MSCs,将其制作为细胞爬片,待其培养至80%融合后,取其中26张爬片放入流室中,施加5dyn/cm2的切应力3h,再定向内皮诱导10d后,取出其中13张(组),另13张(组)继续培养3~4 d后,按1∶3的比例传代。同时设定向内皮诱导前后均不施加切应力的MSCs为对照组(n=13)。用荧光实时定量逆转录-聚合酶链反应(RT-PCR)检测3组的t-PA mRNA表达水平。结果大鼠MSCs定向内皮诱导7d后,具有典型内皮细胞形态。组和组的t-PA mRNA表达水平与对照组比较明显升高(P<0.05),组虽较组稍降低(P>0.05),但仍明显高于对照组(P<0.05)。结论流动切应力对MSCs体外诱导所得内皮细胞具有保护作用,并可随着细胞的传代而得以保持。这一结果将为动脉粥样硬化疾病的治疗和心血管组织工程种子细胞的选择提供新的理论依据。更多还原

【Abstract】 Objective To investigate the messenger ribonucleic acid(mRNA) expression level of tissue-type plasminogen activator(t-PA) in endothelial cells derived from adult mesenchymal stem cells(MSCs) after fluid shear stress loading which is within the physiological range.Methods After culturing in vitro,bone marrow MSCs of SD rats were seeded on slides.When it come to 80% confluence,26 slides were exposed to 5dyn/cm2 fluid shear stress for 3h in a flow chamber,and then induced to endothelial cells.Among them,13 slides constituted group Ⅰ,and the rest 13 slides set up group Ⅱ,which would be cultured for 3-4d further and passaged in 1∶3.At the same time,control group was set up,which including the cells never exposed to fluid shear stress before the endothelial differentiation.Fluid shear stress were exerting to cells in a specially made flow chamber.The expression level of t-PA mRNA of all groups were measured by real-time fluorescent quantitation reverse transcription-polymerase chain reaction(RT-PCR).Results After endothelial differentiation for 7 days,the SD rats bone marrow MSCs acquired typical endothelial cell appearance.The t-PA mRNA expression level of group Ⅰ and group Ⅱ have an obviously enhance compared with control group(P<0.05).The t-PA mRNA expression level of group Ⅱ step down a little(P>0.05),but it is still significantly higher than that of control group(P<0.05).Conclusion Fluid shear stress could provide a protective action on the endothelial cells induced from MSCs in vitro,and the effect maintains with the cells passages.This formulates a theoretical foundation to the therapeutics of atherosclerosis and selection of seed cells in vascular tissue engineering.更多还原