Overexpression of UHRF1 protects human lens epithelial cell apoptosis induced by oxidative stress through regulating ROS/Rb/p16INK4A signaling pathway

Objective This study aims to investigate a role of UHRF1 in modulating anti-oxidative stress and anti-apoptosis in lens epithelial cells (LECs), and elucidate its potential mechanisms. Methods Real-time quantitative PCR was performed to detect the expression level of UHRF1 in cataract patients both in vivo and vitro. HLEC-3 cell viability was test using CCK-8 activity kit by adding H2O2(100 μm, 12 h)to lens epithelial cells The changes of oxidative stress-induced apoptosis-related proteinsBax, Bcl-2, PCNA, Rb and p16INK4A in HLEC-3 transfected with UHRF1 were detected by Western Blotting. The Caspase-3 activity Kit was used to detect the changes of caspase-3 activity in HLEC-3 cells induced by oxidative stress (100 μm, 12 h) after overexpressing UHRF1 for 48h. Results The expression of UHRF1 was significantly down-regulated in cataract patients both in vitro and vivo(P=0.032). Levels of ROS and MDA were enhanced in H2O2 group compared with control group, while SOD and GSH-Px were markedly reduced. However, overexpression of UHRF1 significantly decreased exprerssions of ROS and MDA and increased the activities of SOD and GSH-Px. Overexpression of UHRF1 can significantly reversed the decrease in HLEC-3 cell activity induced by H2O2. After overexpressing UHRF1 for 36 h and then treat with H2O2 100 μmol/L for 12 hours, the results of Western blot showed that the protein level of Bax and PCNA in UHRF1 group was significantly higher than that in the control group, while the expression of Bcl-2 was significantly reduced. Caspase-3 activity was also higher in the experimental group than that in the H2O2 group after overexpressing UHRF1(P=0.021). The expression of Rb (P=0.041) and p16INK4A(P=0.038) was up-regulated by H2O2 in the experimental group than that in the control. Conclusion UHRF1 protects HLECs against oxidative stress-induced apoptosis via the inhibition of the ROS/Rb/p16INK4A pathway. UHRF1 could potentially become a biomarker for preventing ocular aging and cataract in the future. Key words: ROS/Rb/p16INK4A; Lens epithelial cells; Cataract; UHRF1