Abstract: Objective Observe effections of TIMP-3 on proliferation, migration and apoptosis of rabbit vascular smooth muscle cells（VSMC）transfected by recombinant plasmid vectors mediated by cationic liposome and then discuss the TIMP-3 gene therapy on in-stent restenosis（ISR）. Methods Divide VSMC into three groups as normal control group, empty plasmid group and recombinant group,and then do transfection separately.First, at time of 24hours, 48hours and 72hours , calculate cells ,quantify MMP-2 and analyse TIMP-3 mRNA. Second, measure cell apoptosis rate after 48hours. Third, establish a migration model ,then calculate migrated cells after 48hours. Resuls There were no difference between normal control group and empty plasmid group in cells grow, MMP-2’s content , TIMP-3 mRNA expression and apoptosis rate,cells migration rate.While recombinant group had obvious difference compared with the other two,P<0.05. Conclusions It is testified TIMP-3 can strongly inhibit proliferation or migration of VSMC in vitro, but promote apoptosis on the other hand. Cationic liposome is a safe medium which can provide broad application in TIMP-3 gene therapy on ISR.

Key words: TIMP-3, vascular smooth muscle cells, cationic liposome, gene transfection, in-stent restenosis