Objective To construct mesenchymal stem cells(MSCs) of Dualstable expression of angiotensin Ⅱ type 2 receptor(AT2R) gene medicated by tetracycline regulatable system. 〖WTFZ〗Methods Rat MSCs were transfected twice successively with tetracycline induced regulatable system by DOTAP liposomal transfection reagent.The luciferase protein activity was detected in different cell clones by luminometer and the expression of AT2R mRNA was evaluated by reverse transcription polymerase chain reaction (RT-PCR) respectively. According to the expression levels regulated by do

xycycline in different cell clones

the MSC line was filted with high induction and low background.The expression of AT2R in MSCs was evaluated in different concentration of doxycycline(0－10

4

ng/ml) and time after transfection(0－8 weeks) by western blot.  Results The expression rate of AT2R in double stable MSCs was increasing significantly by addition of doxycycline in a concentration-dependent manner by western blot

and the high expression was detected at 48 h after induced by doxycycline and could keep up over 8 weeks.  Conclusion The well established double stable MSC lines make the AT2R gene under the active control of doxycycline and can be used as a good model to study the biological effect of AT2R .