OBJECTIVE Based on fibroblast activation protein(FAP)gene promoter as the response element,to develop a new dual luciferase reporting system for the screening of drugs related to myocardial fibrosis.METHODS The promoter fragment of mouse FAP gene was synthesized in vitro and cloned into plasmid psiCHECK2 to replace HSV-TK promoter,and then a new recombinant plasmid psiCHECK2-FAP was obtained.After the recombinant plasmid psiCHECK2-FAP was digested by restriction endonucliase Hind Ⅲ,the product digested was identified by agar-gel electrophoresis and sequencing.After psiCHECK2-FAP was transient transfected into mouse cardiac fibroblasts(MCFs),and continued cultured for 24 h,and MCFs were treated with Ransforming growth factor β1(TGF-β1,5 μg·L-1)or angiotensinⅡ(Ang Ⅱ,1 μmol·L-1)or palmitic acid(PA,100 μmol·L-1)for 0,12,24,48 h,respectively,the double luciferase reporter gene assay was used to detect luciferase activity;After psiCHECK2-FAP was transient transfected into MCFs,the cells were pretreated with Dapa(1 μmol·L-1)for 1 h,and supplemented with TGF-β1(5 μg·L-1)or AngⅡ(1 μmol·L-1)or PA(100 μmol·L-1),continued treatment for 24 h,the double luciferase reporter gene assay was used to detect luciferase activity,and the expression of collagenⅠand collagen Ⅲ protein was detected with Western blotting.RESULTS The recombinant plasmid psiCHECK2-FAP was digested into two fragments by Hind Ⅲ with the expected strip size,and the sequencing results were completely consistent with the theoretical sequence;Compared with control group,the collagenⅠand collagen Ⅲ protein expression were significantly increased by TGF-β1 or Ang Ⅱ or PA in MCFs(P<0.05,P<0.01).However,compared with TGF-β1 or Ang Ⅱ or PA group,the intervention of Dapa significantly alleviated the promoter activity of FAP gene and the expression of collagenⅠand collagen Ⅲ protein(P<0.05,P<0.01);Compared with control group,luciferase activity was significantly increased by TGF-β1 or Ang Ⅱ or PA(P<0.05,P<0.01),reaching the peak at 24 h.Compared with TGF-β1 or AngⅡ or PA group,the intervention of Dapa significantly decreased luciferase activity(P<0.05,P<0.01).CONCLUSSION Based on the promoter of FAP gene as the response element,a noval dual luciferase reporter gene system was established and showed a good sensitivity to the promyocardial fibrosis factor in MCFs,which can provide strategies for the development of antimyocar-dial fibrosis drugs.