Objective To investigate the mechanism by which lectin-like oxidized low density lipoprotein receptor-1(LOX-1)regulates hyperglycemic-induced myocardial fibroblast(CFs)fibrosis through the glycogen synthase kinase-3β(GSK-3β)/signal transducer and activator of transcription 3(STAT3)pathway.Methods CFs were isolated,cultured and identified.LOX-1 RNAi lentiviral vector was constructed and infected CFs.The experimental groups were as follows:Normal control(NC)group,High glucose(HG)group,LV-LOX-1,LV-Con group,Hypertonic(HPG)group.After LV-LOX-1 and LV-Con were infected with CFs,adding 25 mmol/L glucose to culture CFs for 24 h,they were denoted as HG+LV-LOX-1 group and HG+LV-Con group.Cells in HG+LV-LOX-1 group and HG+LV-Con group were treated with 10 μ mol/L SB216763 and 10 μ mol/L STATTIC for 24 h,respectively,and then they were recorded as HG+LV-LOX-1+SB216763 group,HG+LV-Con+SB216763 group,HG+LV-LOX-1+STATTIC group and HG+LV-Con+STATTIC group.CCK-8 was used to detect the activity of CFs,and the expression levels of mRAN and protein of LOX-1,collagen type I(COL-I),thioredoxin 5(TXNDC5),GSK-3β,STAT3,p-GSK-3β and p-STAT3 were detected by qRT-PCR and Western blot.Results CFs infected with LOX-1 RNAi lentiviral vector were obtained,which showed green under fluorescence microscopy.Compared with HG and HG+LV-Con groups,the mRNA expressions of LOX-1,COL-I and TXNDC5 were decreased in HG+LV-LOX-1 group(P<0.05).Compared with HG+LV-LOX-1 group,mRNA expressions of COL-I and TXNDC5 were decreased in HG+LV-LOX-1+SB216763 and HG+LV-LOX-1+STATTIC groups(P<0.05).Compared with HG and HG+LV-Con groups,p-GSK-3β protein expression was increased in HG+LV-LOX-1 group(P<0.05),while LOX-1,p-STAT3,COL-I,TXNDC5 protein expression was decreased in HG+LV-LOX-1 group(P<0.05).Compared with HG+LV-LOX-1 group,p-GSK-3β protein expression was increased in HG+LV-LOX-1+SB216763 group(P<0.05),while the protein expressions of p-STAT3,COL-I and TXNDC5 were decreased in HG+LV-LOX-1+SB216763 and HG+LV-LOX-1+STATTIC groups(P<0.05).Conclusion LOX-1,GSK-3β,STAT3,TXNDC5,and COL-I are involved in high glucose induced CFs fibrosis.LOX-1 promotes the expression of TXNDC5 and COL-I through GSK-3β/STAT3 pathway,and inhibition of LOX-1 can inhibit high glucose induced CFs fibrosis.