ApoA-I Mimetic Peptide D-4F Alleviates Contrast Mediainduced Oxidative Injuries In Endothelial Cells Via AMPK/PKC Pathway

Objective:The purpose of this study was to further investigate the molecular mechanisms of apolipoprotein A-I mimetic peptide,D-4F,on the oxidative injuries of endothelial cells induced by contrast media.Methods:Primary human umbilical vein endothelial cells(HUVECs)were isolated and cultured in vitro.The activation of PKCbeta II,NF-kappaB(P65),NOX(P47)and eNOS uncoupling triggered by contrast media(iodixanol)were detected by western blot.The expression of NOX2/4 induced by contrast media were also dectected.The release of reactive oxygen species(ROS)in endothelial cells was detected by reactive oxygen species probe.We further tested whether apolipoprotein A-I mimetic peptide,D-4F,could alleviate the activation of PKCbeta II,NF-kappaB(P65),NOX(P47)and eNOS uncoupling triggered by contrast media,and whether AMPK inhibitor,Compound-C,could decrease the protective effects of D-4F on these pathway activation and ROS release.SD rats were divided into Control,Contrast media group,Contrast media+D-4F group,respectively.Then,the contrast agent was injected into the tail vein in contrast media group and contrast media+D-4F group.All rats were killed and the carotid artery was separated after 24 hours.Immunohistochemistry confirmed the effect of contrast media on vascular endothelial injury and adhesion molecule expression.Results:The contrast agent furtherly activated P65,NOX and eNOS uncoupling through PKC activation,thereby causing the production and release of reactive oxygen species,leading to the occurrence of cellular inflammation and apoptosis.Whereas D-4F can furtherly inhibit the activation of PKC by inducing phosphorylation of AMPK protein,thereby exerting the protective function of endothelial cells.The protective effect was obviously weakened after adding AMPK inhibitor.Under high magnification,we observed that the degree of carotid endothelium injury and adhesion moleculer expression in the contrast agent group were significantly higher than those in the D4F pre-protective group.Conclusion:Apolipoprotein A-I mimetic peptide D-4F inhibited PKC and its downstream molecular expression,ROS release by activating AMPK,antagonizing contrast-induced apoptosis and inflammatory response of HUVECs.