The Effect Of Selenium On Oxidative Damage, Apoptosis And Ultrastructure Of Human Thyrocyte Culture In Vitro

Objective To investigate the influence of selenium(Se) on oxidative damage, apoptosis and ultrastructure of human thyrocyte induced by H₂O₂ culture in vitro.Methods The human thyroid epithelium cells(TEC) from para-adenoma normal tissues of patients with thyroid adenoma were cultured.Added different concentration H₂O₂ (0-800μmol/L) into thyrocyte of monolayer culture after with or without Se(10^-7mmol/L).The thyrocyte viability was detected using MTT stain.Flow cytometry detected apoptosis rates of thyrocyte. The activity of GSH-Px and content of MDA were detemined. And the thyrocyte ultramicrostructure of each group were observed.Results When the thyrocyte exposed to H₂O₂ for 24 hours,the cell viability declined,and cell apoptosis rates increased, the GSH-Px activity declined,and MDA content increased,with a relation of dose-effect response on the rang of 100-800μmol/L. Under the TEM, simply selenium intervention group thyrocytes ultrastructure similar to the normal control group.When H₂O₂ concentration was 100-200μmol/L,TEM showed that thyrocytes showed damaging changes.When H₂O₂ concentration was 400-800μmol/L, TEM showed that thyrocytes showed apoptosis even death. Adding Se(10^-7mmol/L) into cell culture could effectively increase viability and reduce the thyrocyte apoptosis caused by H₂O₂.Compared to the simple H₂O₂ intervention group the GSH-Px activity declined,and MDA content increased. Selenium pre-intervention in each group can be seen cell ultrastructure injury lessen significantly.Conclusions H₂O₂ can inhibit the proliferation and induce oxidative damage even apoptosis of the TEC. Selenium could protect thyroid follicular epithelial cell against oxidative damage caused by H₂O₂.Selenium could protect thyroid follicular epithelial cell against oxidative damage and apoptosis caused by H₂O₂.Selenium may be that role by increasing cell GSH-Px activity and to reduce the content of MDA antagonistic the oxidative stress ways to achieve.