Astaxanthin Inhibits Endothelial Progenitor Cell Apoptosis Induced by Oxidative Stress via Mitochondria-targeted Protective Mechanism / 医药导报

ABSTRACT

Objective To investigate the effect of astaxanthin( ASX)on endothelial progenitor cells( EPCs)injury induced by oxidative stress in vitro and to explore its underlying mechanism. Methods Cultured EPCs isolated from peripheral blood were randomly divided into 5 groupsnormal control,model group[ tert-butyl hydroperoxide( tBHP)100μmol·L-1 ],and ASX+tBHPgroups(thecellswerepreconditionedwithASX0.1,1.0,and10.0nmol·L-1,respectively).Thecellviabilitywas measured by MTT method. The level of reactive oxygen species( ROS)was determined by DCFH-DA method. The changes of mitochondrial membrane potential( MMP)and apoptosis ratio were detected by JC-1 method and DAPI method,respectively. caspase-3 activity changes of EPCs were detected. Results The cell viability of EPCs was improved with the increasing concentration of ASX. Compared with the model group[(48. 5±4. 3)%],0. 1,1. 0,10. 0 nmol·L-1 ASX significantly increased the cell viabilities[(57. 6±8. 2)%,(77. 6±7. 5)%,and(85. 3±6. 1)%,P﹤0. 05]. The results of DAPI staining revealed that ASX pretreatment could significantly reduce the apoptotic rate of EPCs. The apoptotic rate of the model group was( 27. 8 ± 3. 2)%,while that of ASX+tBHP groups was[(20. 4±2. 9)%,(14. 9±1. 7)%,and(7. 8±0. 7)%,P﹤0. 05],respectively. The data from caspase-3 activity assay indicated that ASX precondition could also remarkably decrease the caspase-3 activity for EPCs. The caspase-3 activity of the model group was(0. 345±0. 018),while that of the ASX+tBHP group were[(0. 291± 0. 013),(0. 209±0. 004),and(0. 169±0. 013),P﹤0. 05],respectively. In addition,treatment with tBHP resulted in an increase of DCF fluorescence,while ASX precondition could decrease the DCF fluorescence,which suggested the accumulation of intercellular ROS for EPCs. Injury of michondrial membrane resulted in the loss of mitochondrial membrane potential( MMP). The MMP detected by JC-1 method revealed that compared with model group,pretreatment of ASX inversed the reduction of MMP. Conclusion Astaxanthin inhibits endothelial progenitor cell apoptosis induced by oxidative stress through inhibiting ROS production,improving the mitochondrial function and down-regulating caspase-3 activity.