ABSTRACT
<p><b>OBJECTIVE</b>In oder to treat periodontitis by using tissue engineering and gene engineering technology, the article established an transient expression system of bone marrow stromal cells (BMSC) modified by osteoprotegerin (OPG) gene and detected its expression using eukaryotic secreted expression pSecTag2/B-OPG plasmid.</p><p><b>METHODS</b>By solation and culture of BMSC in vitro, the identified recombined plasmid was transiently transfected into BMSC by Lipofectamine 2000 and OPG expression in BMSC was determined by RT-PCR and Western blot in 6 weeks.</p><p><b>RESULTS</b>The fragments of the recombinant plasmid digested with Hind III, EcoR I and BamH I and examined by 10 g/L agarose electrophoresis, were consistent with predicted size. The sequence of OPG was identical to the sequence provided by GeneBank [gi:33878056]. OPG transcribing in BMSC was confirmed by RT-PCR and OPG sustainable expressing in BMSC was detected by Western blot in 39 days.</p><p><b>CONCLUSION</b>The transiently expression system of BMSC modified by OPG gene was successfully established.</p>