中文摘要：

目的观察骨形成蛋白（bone morphogenetic protein，BMP）7重组腺病毒对大鼠骨髓间充质干细胞（mesenchymal stem cell，MSC）骨向分化的影响。方法构建重组腺病毒载体pAd-BMP-7，测定其滴度。应用pAd-BMP-7和空白载体pAdTrack—CMV分别转染MSC，检测外源基因转染效率，并应用RT-PCR、免疫细胞化学手段检测BMP-7的表达。将MSC分为3组，A组：转染pAd-BMP-7；B组：转染pAdTrack-CMV；C组：转染pAdTrack-CMV＋骨向分化液。观察其矿化结节形成，评价3组细胞骨向分化情况。结果重组腺病毒pad-BMP-7的滴度可达2．0×10^15 pfu／L；外源基因的转染效率为99％，表达时间持续5—7周，3周内表达水平较高。RT-PCR和免疫细胞化学检测证实了BMP-7在MSC中的有效表达。病毒转染后，A组和C组细胞均有矿化结节形成，其中A组矿化结节数目显著多于C组（P〈0．01）；B组无矿化结节形成。结论BMP-7重组腺病毒可有效转染大鼠骨髓MSC，并促进其骨向分化，转染的BMP-7得到了有效表达。

英文摘要：

Objective To study the effect of recombinant pAd-BMP-7 on osteogenic differentiation of rat bone marrow mesenchymal stem cells （ MSC ）. Methods Recombinant pAd-bone morphogenetic protein（ BMP）7 was constructed and the titer of recombinant adenovirus was determined, pAd-BMP-7 and pAdTrack-CMV were used to transfect rat MSC. Transfection efficiency was measured by fluorescent microscope and BMP-7 expression was detected by RT-PCR and immunocytochemical analysis. The MSC were then randomly divided into 3 groups： group A received pAd-BMP-7 transfection, group B was transfected with pAdTrack-CMV, and group C received pAdTrack-CMV transfection plus bone supplements. Osteogenic differentiation of MSC was evaluated by examination of mineralization nodes formation. Results The titer of pAd-BMP-7 reached about 2. 0 × 10^15 pfu/L and transfection efficiency of exogenous gene was nearly 99% at day 2. The expression of exogenous gene sustained about 5 to 7 weeks, with a higher level during first 3 weeks. After transfection, transcription of BMP-7 and expression of BMP-7 protein were also verified in MSC. Compared with the negative results in group B, mineralization nodes were formed in both group A and group C. However, group A showed better formation of mineralization nodes than group C （P 〈 0.01）. Conclusions The results of this study indicated that recombinant pAd-BMP-7 can successfully transfect rat MSC and accelerate their osteogenic differentiation. The technique explored in this study provides a unique and valuable gene engineering approach for reconstruction of cranlofacial bone defects.