Fig. 8.

Upregulation of methylation by H₂O₂ treatment in a time-dependent manner. (A) Cell image before H₂O₂ treatment. (B) Cell image after 24 h of treatment with 200 μM H₂O₂. (C) CCK-8 assay revealed that the proliferation of LECs was significantly decreased after 24 h of treatment with 200 μM H₂O₂. n = 4 independent experiments. (D) The methylation levels of selected CpG units in the GSTP1 and TXNRD2 promoters (CpG units 21–25 of GSTP1; CpG units 34 of TXNRD2) increased in a time-dependent pattern under H₂O₂ treatment. (E) Under H₂O₂ treatment, the relative mRNA levels of GSTP1 and TXNRD2 gradually increased in the first six days and declined at day 8. The expression of DNMT1 remained stable until day 6, when it increased to about 2-fold relative to day 0. n = 3 independent experiments, mean ± SD, unpaired two-tailed Student's t-test, *P < 0.05, **P < 0.01, ***P < 0.001 (each sample was compared to day 0 when statistically analyzed).