Effects Of Rosiglitazone On The Expression Of Gap Junction Protein 43 And Caveolin-1 In Human Coronary Artery Endothelial Cells Induced By Lipopolysaccharide

Objective:To evaluate the role of the peroxisome proliferator-activated receptor-gamma agonist rosiglitazone(RSG)in lipopolysaccharide(LPS)-mediated expression of connexin 43 and caveolin-1inHuman coronary artery endothelial cells(HCAEC).Methods:Human coronary artery endothelial cellswere exposed to different concentrations of lipopolysaccharide(0.01 mg/L,0.1 mg/L,1 mg/L,10mg/L)and peroxisome proliferator-activated receptor-gamma agonistrosiglitazone(1,10,50,100 ?mol/L)for 24 hours,at the same time,a blank control group was established,and the effect of different concentrations of drugs on cell viability was tested by MTT assay and the optimal drugconcentration for this study was selected.HCAEC were randomly divided into four groups: blank control group,LPS group(0.1 mg/L),RSG group(10 ?mol/L)and LPS+RSG group(10 ?mol/L RSG pretreatment for 1 hour and LPS combined for 24 hours).The levels of protein or mRNA of lipopolysaccharide-mediated expression of connexin 43 and caveolin-1 in Human coronary artery endothelial cells were evaluated with Western blot and real-time reverse transcription polymerase chain reaction.Results:(1)MTT assay showed that the effects of four groups of lipopolysaccharide and rosiglitazone on cell viability showed that when LPS concentration was ?1 mg/L(0.287±0.06),cell viability was lower than that of the control group(0.59±0.13)(P<0.05).With the increase of LPS concentration,the inhibition of HCAEC activity was enhanced,and the LPS concentration was below 0.1 mg/L(0.487±0.09),which had no inhibitory effect on cell viability(P>0.05).When the concentration of RSG was ?50?mol/L(0.252±0.011),the activity of HCAEC was lower than that of the control group(0.310±0.014)(P<0.05).Similarly,the inhibition of HCAEC activity was enhanced with the increase of RSG concentration.When the concentration of RSG was below10?mol/L(0.297±0.011),there was no effect on cell viability(P>0.05).(2)Western blot results showed that the protein levels of Cx43(0.57±0.024)and Cav-1(2.91±0.15)in the lipopolysaccharide group were significantly higher than the protein levels of Cx43(0.45±0.015)and Cav-1(2.04±0.14)in the control group and the Cx43(0.40±0.013)and Cav-1(1.91±0.16)in the rosiglitazone group(P<0.01).Compared with the lipopolysaccharide group,the proteinlevels of Cx43(0.32±0.025)and Cav-1(1.90±0.18)in the rosiglitazone pretreatment for 1 hour and lipopolysaccharide combined for 24 hours were significantly lower(P<0.01).(3)According to RT-PCR results,the mRNA levels of Cx43(1.69±0.02)and Cav-1(1.82±0.05)in the lipopolysaccharide group were significantly higher than themRNA levels of Cx43(1.00±0.04)and Cav-1(1.00±0.02)in the control group and the Cx43(0.93±0.02)and Cav-1(0.94±0.02)in the rosiglitazone group(P<0.01).Compared with the lipopolysaccharide group,the mRNA levels of Cx43(0.91±0.01)and Cav-1(0.92±0.03)in the rosiglitazone pretreatment for 1 hour and lipopolysaccharide combined for 24 hours were significantly lower(P<0.01).Conclusion:Lipopolysaccharide mediates the up-regulation of Cx43 and Cav-1 and exerts inflammatory effects,causing endothelial cell damage and promoting the formation of atherosclerosis.PPAR? agonist rosiglitazone can inhibit the increase of lipopolysaccharide-mediated expression of connexin 43 and caveolin-1 in Human coronary artery endothelial cells,and reduce the damage of coronary endothelial cells,thereby exerting anti-atherosclerosis effect.