| Objective:As a kind of metabolic disease and characterized by chronic hyperglycemia,Diabetes has become one of the most challenging health issues of the 21 st century.Increased blood sugar for a long time,will cause great vessels,microvascular damage and threaten the heart,brain,kidney,peripheral nerve,eye,foot,etc.It is estimated that 75% of deaths in patients with diabetes is caused by cardiovascular disease.A growing number of studies show that in the formation and development of diabetes complications of cardiovascular system,inflammation and oxidative stress plays an important role.As everyone knows,high sugar can promote apoptosis of endothelial cells,and therefore the incidence of diabetes in patients with AS is much higher than non-diabetic patients.Inflammation and oxidative stress are now recognized as two important contributing factors to atherosclerosis(AS).NADPH oxidase-4(Nox4)-derived reactive oxygen species(ROS)and MAPK are playing crucial roles in these processes.This study established high glucose injury model of vascular endothelial cells,and injected different concentrations lipoic acid,which is a strong oxidant,to test whether LA can inhibit high glucose-induced inflammation and oxidative stress in human aortic endothelial cells(HAECs)and uncover some of the mechanisms underlying.Methods:HAECs were treated with different concentrations of LA(50,100,200 ?M),then stimulated with high glucose(30?M).GSH level was measured with colorimetric assaykit.Flow cytometry was performed to test the effect of LA on the intracellular ROS level caused by high glucose in HAECs.Western Blot analysis was employed to detect protein expression of Nox4,p22 phox,Caspase-3 and Bcl-2.Cytochrome C release from mitochondria and activation of NF-?B were also evaluated by Western blot analyses.Real-time RT-PCR was adopt to test mRNA expression of Nox4,p22 phox.Results:1.Compared with control group,high glucose significantly decreased GSH level(p< 0.01).After treated with LA,GSH level in HAECs was remarkably increased(p<0.01).2.Compared with control group,high glucose inreeased ROS over-generation(p< 0.01),Nox4 and p22 phox over-expression(p<0.01,p<0.01).LA inhibited the high glucose-activated ROS generation(p<0.01),as well as Nox4,p22 phox,Caspase-3expressions(p<0.01,p<0.01,p<0.01).3.Comperaed with control group,high alone increased I-?B degradation in cytosol and the tranclocation of P65 in the nucleus(p<0.01,p<0.01).On the contrary,LA abolished high glucose-induced I-?B degradation and the tranclocation of P65(p<0.01,p<0.01).4.After treated with high glucose,Bcl-2 expression was reduced and Caspase-3 expression was increased(p<0.01,p<0.01).On the contrary,LA abolished the reduction of Bcl-2 expression and inhibited Caspcase-3 expression in HAECs(p<0.01,p<0.01).5.Compared with control group,high glucose increased Cytochrome C release from mitochondria,but LA singnificantly decreased Cytochrome C release from mitochondria(p<0.05).LA attenuated high glucose-induced oxidative stress and inflammation through actions on Nox4/ROS and NF-?B pathways.Conclusion:LA inhibited high glucose induced ROS over generation in HAECs,inhibited Nox4 and p22phox over expressions.LA significantly decreased Caspase-3 expression and abolished Bcl-2 reduction in high glucose induced HAECs.At the same time,LA inhibited Cytochrome C release from mitochondria and NF-?B pathway transcriptionalactivity,therefore inhibited high glucose induced oxidative stress,inflammatory response as well as apoptosis in HAEC.We suggested that LA inhibited ROS over-generation throuth abolish Nox4 expression and LA inhibited oxidative stress and inflammatory response via affect NF-?B... |
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