Effects Of Oxidative Stress On Expression Of SMP30 In Human Lens Epithelial Cells

Purpose: This study is to investigate the effects of oxidative stress on expression of Senescence Marker Protein30(SMP30)in human lens epithelial cells(HLECs),lay a foundation for further study of its role in the development of lens epithelial cells and cataract.Methods: HLECs were treated with H2O2(0,100,200,300?M)over 24 h,to mimic an associate with acute oxidative stress model,observed the changes of cell morphological and using MTT analyzed cells state,the expressions of SMP30 were measured by Western blotting.HLECs were treated with H2O2(0,25,50,75,100,125,150?M)to mimic an associate with ageing model,observed the changes of cell morphological and using MTT,SA-?-Gal staining and cell cycle to analyzed cells state.The expression of SMP30 mRNA and protein were measured by q-PCR and Western blotting.Results: Showed that cell density decreased,morphological changed and viability of cells significant decreased after 24 h in H2O2 treated group,Cells were all crushed after exposure to 300?M.The viability of cells were decreased in treated group(p<0.05).We found that the expression of SMP30 in 100,200?M treated group were increased significantly compared with the controlgroup(p<0.05).After culture cells two weeks,there were no significant change of cell morphology between control group and 25?M H2O2 group.Cells exposure to 50 and 125?M H2O2 became enlarged and decreased in cell density,Cells were all crushed after exposure to 150?M.MTT show that with exposure to 25-50?M H2O2 the growth curve declined compared with control group.75?M H2O2 could inhibit the activities of cells and maintain basic metabolic activity barely.With 100-150?M H2O2,growth curve declined substantially.The percentage of SA-?-Gal positive cells increased dramatically in 75-150?M H2O2 treated group(>90%,p=0.00).50-100?M H2O2 could disrupt the normal cell cycle progress,arrested SRA01/04 in S and G2/M phase and increase PI value.We found that SMP30 mRNA was down-regulated in 25-100?M H2O2group(p<0.01),there was no significant change in 25 and 50?M H2O2 group on the protein level.(p=0.695,p=0.126),but down-regulated significantly in75-100?M H2O2 group.Conclusions: SMP30 was up-regulated in HLECs induced by H2O2 acute oxidative stress,in the early stage of senescence induced by H2O2 chronic oxidative stress,there was no significant change in SMP30 expression,but with the oxidative stress increased and senescence aggravated,SMP30down-regulated significantly in the senescent HLECs.SMP30 as an important factor involved the process of oxidative stress in HLECs may related to the ageing process in HLECs and the development of cataract.