Using human vascular endothelial cells(ECV304)as the target,we studied the effect ofcaveolin(CAV)-1 in the course of insulin-stimulated expression of plasminogen activator inhibitor(PAl)-1.The appropriate single-stranded oligonucleotides representing the RNAi CAV- 1 gene were analyzed by Ambionsoftware.After annealing to generate double-stranded oligonucleotides(ds oligo),it was cloned into thepENTR/U6 entry vector containing RNA polymerase Ⅲ expression element by T4 DNA ligase.The shorthairpin(shRNA)sequences transferred from the pENTR/U6 entry were cloned into the pLenti6/BLOCK-iT-DEST vector with an LR recombination reaction.After identification by sequencing,we successfully con-structed the CAV-1 RNAi lentiviral expression system using Gateway technology.Silencing efficiency wasassayed by real-time reverse transcription-polymerase chain reaction,immunofluorescence staining and Westernblotting.ECV304 cells were cultured in the medium containing different concentrations of insulin(1×10~(-9)to1×10~(-7)M)with the CAV-1 gene silenced or not.The expression level and subcellular localization of PAI-1 andCAV-1 were compared using reverse transcription-polymerase chain reaction,immunofluorescence stainingand Western blot assay.The results showed that the potent inhibition of CAV-1 expression could reach 85%,and it was specific to the CAV-1-derived shRNA,not the S 100A13-derived shRNA.There was no dramaticdifference in PAI-1 expression between the RNAi~+ and RNAi~- ECV304 cells incubated with physiologicalinsulin,but PAI-1 protein did accumulate under the cell membrane.As the concentration of insulin increased,the expression of PAI-1 was up-regulated,whereas the expression of CAV-1 attenuated.Furthermore,PAI-1 clearly augmented after CAV-1 knockdown.These results indicated that hyperinsulinism could promotePAI-1 expression by inhibiting CAV-1,and stabilizing or up-regulating CAV-1 expression in endothelial cellsmight reduce complications of the great vessels and capillary vessels in diabetes. Using human vascular endothelial cells (ECV304) as the target, we studied the effect of conserved of CAV-1 in the course of insulin-stimulated expression of plasminogen activator inhibitor (PAI) -1. The appropriate single-stranded oligonucleotides representing the RNAi CAV - 1 gene was analyzed by Ambionsoftware. After annealing to generate double-stranded oligonucleotides (ds oligo), it was cloned into the pENTR / U6 entry vector containing RNA polymerase III expression element by T4 DNA ligase.The shorthairpin (shRNA) sequences transferred from the pENTR / U6 entry were cloned into the pLenti6 / BLOCK-iT-DEST vector with an LR recombination reaction. After identification by sequencing, we successfully con-structed the CAV-1 RNAi lentiviral expression system using Gateway technology .ilencing efficiency wasassayed by real- time reverse transcription-polymerase chain reaction, immunofluorescence staining and Western blotting. ECV304 cells were cultured in the medium containing different concentrations of insulin ( 1 × 10 -9 to 1 × 10 -7 M) with the CAV-1 gene silenced or not.The expression level and subcellular localization of PAI-1 andCAV-1 were compared using reverse transcription-polymerase chain reaction , immunofluorescence staining and Western blot assay. These results showed that the potent inhibition of CAV-1 expression could reach 85%, and it was specific to the CAV-1-derived shRNA, not the S 100A13-derived shRNA. There was no dramatic difference in in PAI-1 expression between the RNAi ~ + and RNAi ~ - ECV304 cells incubated with physiologicalinsulin, but PAI-1 protein did accumulate under the cell membrane. As concentration of insulin increased, the expression of PAI-1 was up-regulated, but PAI- The expression of CAV-1 attenuated. Focus MoI, PAI-1 clearly augmented after CAV-1 knockdown.These results indicated that hyperinsulinism could promotePAI-1 expression by inhibiting CAV-1, and stabilizing or up-regulating CAV-1 expression in endothelial cells reduce complications of the great vessels and capil lary vessels in diabetes.