中文摘要：

目的：探讨体外负压培养对骨髓间充质干细胞（bone marrow derived stroma cells,BMSCs）成骨活性的影响。方法：取第3代BMSCs分为实验组和对照组,实验组进行间歇性负压培养,设置压力为17kPa,每次30min,每日4次,干预2周;对照组于普通CO2培养箱中常规培养。倒置显微镜下观察细胞形态,检测ALP活性,免疫组织化学检测Ⅰ型胶原的表达,RT-PCR检测2周后以及终止负压后1、2、3d骨保护素（osteoprotegerin,OPG）mRNA和骨保护素配体（osteoprotegerin ligand,OPGL）mRNA表达水平。结果：诱导2周后,BMSCs呈现出显著的成骨细胞特性,与对照组比较,ALP活性显著增加,Ⅰ型胶原表达阳性,实验组细胞OPG mRNA表达水平显著提高,OPGL mRNA表达水平显著降低,且差异均有统计学意义（P〈0.05）。负压终止后3d,两组细胞OPG mRNA和OPGL mRNA表达水平差异无统计学意义（P〉0.05）。结论：体外负压培养可以提高BMSCs成骨活性。

英文摘要：

Objective：To investigate effects of intermittent negative pressure on osteogenesis in human bone marrow-derived stroma cells（BMSCs） cultured in vitro.Methods：The third passage cells were divided into negative pressure treatment group and control group.The cells in the treatment group were induced by negative pressure intermittently（pressure：17 kPa,30min per time,and four times of each day）.The cells in the control group were cultured in conventional condition.The osteogenesis of BMSCs was examined by phase-contrast microscopy.The alkaline phosphatase（ALP） activities were determined.The expression of collagen type I was detected by immunohistochemistry method.The mRNA expressions of osteoprotegerin （OPG） and osteoprotegerin ligand （OPGL） in BMSCs were analyzed by real-time polymerase chain reaction （PCR）.Results：BMSCs showed a typical appearance of osteoblast after 2 weeks of induction by intermittent negative pressure.The activity of ALP increased significantly,and the expression of collagen type I was positive.In the treatment group,the mRNA expression of OPG increased significantly （P0.05） and the mRNA expression of OPGL decreased significantly （P0.05） after 2 weeks,compared with the control.However,3 days after the exposure to 2-week negative pressure,these were no significantly different from that of the control group（P0.05）.Conclusion：Intermittent negative pressure could promote osteogenesis in BMSCs in vitro.