Protective Effects Of Trimetazidine In Retarding Selenite-induced Lens Opacification

?Objective?:To explore whether trimetazidine?TMZ?could retard the onset progress of lens opacification in vivo experiments with Sprague-Dawley?SD?suckling rats and rescue the oxidative stress of HLEB3 cells in vitro studies.?Materials and methods?:HLEB3 cells and SD rat pups were randomly divided into 4 groups respectively:group I,normal control group;group II,TMZ group;group III,selenite group;and group IV,TMZ+selenite group.Lens opacification induced by sodium selenite were executed using a subcutaneous injection of sodium selenite?20?mol/kg bodyweight?in suckling rats on postnatal day 10,while HLEB3 cells treated with 8?M sodium selenite for 24 hours was used to build the oxidative stress model in vitro.The anti-oxidant stress-related enzymes?activities of SOD,MDA,·OH and H₂O₂ levels?are often used to evaluate the effects of antioxidants on the selenite cataracts model during formation of lens opacification.CCK-8 assay kit,bisulfite DNA sequencing,flow cytometry,DNA fragmentation?DNA Ladder?,western blotting and intracellular ROS staining were used in this study to determine the cell apoptosis.?Results?:A total of 50%of the cells were apoptotic with 8?M of sodium selenite compared to group I while the apoptosis rate was reduced with TMZ treatment.Our study found that TMZ can retard the onset progress of lens opacification during in vivo experiments with Sprague-Dawley?SD?suckling rats and rescue the morphology of HLEB3 cells in vitro.Flow cytometry and DNA fragmentation assay showed that TMZ could prevent the cell apoptosis induced by sodium selenite.We further found that the apoptosis-associated Bcl-2 and Nrf2 were dramatically decreased while Bax and Keap1 were elevated in vivo and in vitro,based on Western blotting.In addition,bisulfate DNA sequencing revealed that the demethylation of CpGs in the promoter region of Keap1 was stimulated by sodium selenite,which could be inhibited by TMZ via resuming the expression level of Nrf2.?Conclusions?:Our findings reveals that functioned with Keap1-Nrf2/ARE signalling pathway,TMZ treatment enhanced antioxidant protection,augmented the antioxidant defence provided by enzymes,inhibited the DNA methylation in vivo and in vitro,improved the redox reaction and the anti-oxidative stress,and finally,delayed or prevented the development of lens opacification.TMZ would represent as a promising drug in the field of retarding the oxidative induced cloudiness formation of lens,which is of great significance for early prevention and treatment in cataracts disease.