The Expression Of Mitochondrial Fission/Fusion Genes In RPE Cells Under Oxidative Stress

ObjectiveTo assess the expression of mitochondrial fission genes(Fis1,Dnmp1,MTP18)and fusion genes(Mnf1,Mnf2)in different concentrations of hydrogen peroxide(H2O2)under the oxidative damage in ARPE-19 cells.MethodsThe obtained ARPE-19 cells were divided into the normal control group and the oxidative damage groups treated by different concentrations of H2O2.The oxidative damage groups were treated by H2O2 at the concentrations of 75,150 and 200 μmol/L respectively for 24 h.MTT assay was applied for cell viability.The cell morphology change was observed by phase contrast microscope.The mitochondrial morphology change was recorded by transmission electron microscope.The m RNA levels of mitochondrial fission genes(Fis1,Dnmp1,MTP18)and fusion genes(Mnf1,Mnf2)were measured by RT-PCR and Real-time PCR.ResultWith the increased concentration of H2O2,ARPE-19 cells were shrinking aggravatingly and cell death increased.The mitochondrial structures were destroyed with membranes and cristae.RT-PCR results showed the decreased expression of Fis1 gene,compared with the normal control group in different H2O2 treatment(P < 0.05).There were no significant differences in different concentration of H2O2 groups.The expression of fission genes MTP18,Dnmp1 and fusion genes Mnf1,Mnf2 showed no significant change.Real-time PCR results demonstrated that the expression of Fis1 gene decreased with different concentrations of H2O2 treatment,whereas the expression of Mfn2 gene increased in the treatment of 200 μM H2O2.There were no significant differences of other genes expression.ConclusionThe abnormal expression of mitochondrial fission gene Fis1 and fusion gene Mfn2 caused mitochondrial dysfunction in ARPE-19 cells,indicating the imbalance of mitochondrial dynamics,which might participate for these cell death in oxidative stress environment.