The Relationship Between Reduction Of Oxidative Stress Injury To Human Umbilical Vein Endothelial Cells By Propofol Preconditioning And The JNK Signaling Pathway

BackgroundOxidative stress can cause endothelial cells dysfunction and lead to inflammation and vascular diseases, which is caused by the pathogenic mechanism of mitochondrial dysfunction, cell damage and apoptosis. Mitogen-activated protein kinase (MAPK) plays an important role in the regulation of apoptosis after oxidative stress process. c-Jun N-terminal kinase (JNK), belonging to the MAPK family, regulates cell growth, differentiation, stress and death. The activation of JNK signaling is closely related to apoptosis pathways.Propofol is commonly used in clinical intravenous anesthesia, whose chemical structure is similar to endogenous oxygen free radical scavenger vitamin E, and it has antioxidant activity. Experiments have confirmed that propofol has scavenging reactive oxygen species (ROS) and anti-apoptotic effects. However, the role of JNK signaling pathway in the protective effects is still unknown. Therefore, the present study is to investigate the role of different concentrations of propofol pretreatment on human umbilical vein endothelial cells (HUVECs) oxidative stress injury, to evaluate its relationship with the c-Jun N-terminal kinase (JNK) signaling pathway.Part 1 Propofol prevent cell injury of H2O2-induced oxidative stress in human umbilical vein endothelial cellsObjective:To evaluate the protective effect of different concentrations of propofol preconditioning on oxidative stress injury in human umbilical vein endothelial cells(HUVECs).Methods:Cultured HUVECs in vitro were divided into eight groups as follows: control group (group C1), DMSO group (group C2), propofol group(group P), H2O2 group(group H), H2O2+1μmol/L propofol preconditioning group(P1+H group), H2O2+5μmol/L propofol preconditioning group(P5+H group), H2O2+25μmol/L propofol preconditioning group(P25+H group), H2O2+50μmol/L propofol preconditioning group(P50+H group). The cell viability was measured by CCK-8, the level of intracellular reactive oxygen species was quatified by fluorescence microscopy.Results:Compared with Cl group, the cell viability was significantly decreased, the intracellular ROS were increased in H group (P<0.05). However, the cell viability and ROS production were not significantly different from C2 group and P group compared with Clgroup(P>0.05). Compared with H group, the cell viability were significantly increased, the ROS production were decreased in P25+H group and P50+H group.(P<0.05).Conclusion:Propofol (25μmol/L and 50μmol/L) preconditioning can attenuates oxidative stress induced injury to HUVECs.Part 2 Effect of propofol on cell apoptosis and the JNK signaling pathway of H2O2-induced oxidative stress inhuman umbilical vein endothelial cellsObjective:To evaluate the role of c-Jun N-terminal kinase (JNK) signaling in the protective effect of propofol preconditioning against oxidative stress induced apoptosis in human umbilical vein endothelial cells(HUVECs).Methods:Cultured HUVECs were divided into eight groups as follows:control group (group Cl), DMSO group (group C2), propofol group(group P), H2O2 group(group H), H2O2+lumol/L propofol preconditioning group(P1+H group), H2O2+5μmol/L propofol preconditioning group(P5+H group), H2O2+25μmol/L propofol preconditioning group(P25+H group), H2O2+50μmol/L propofol preconditioning group(P50+H group). The cell apoptosis was assessed by flow cytometry, and the levels of JNK phosphorylation(p-JNK), caspase 3, Bcl-2 and Bax in HUVECs were determined by Western blot. The apoptotic rate and Bcl-2/Bax ratio were calculated.Results:Compared with C1 group, the apoptotic rate were increased, p-JNK,caspase-3 and Bax expression was up-regulated and Bcl-2 expression was down-regulated in H group (P<0.05). Compared with H group, caspase-3 protein expression and Bcl-2/Bax ratio were significantly increased, the apoptotic rate were decreased, and the p-JNK expression was increased in P5+H group, P25+H group and P50+H group.(P<0.05).Conclusion:Propofol (5μmol/L,25μmol/L and 50μmol/L) preconditioning can attenuates oxidative stress induced apoptosis to HUVECs with underlying possible mechanism may be related to the JNK signaling pathway inhibition.