DNMT1 and Hyperglycemia: However, a significantly increased cytoplasmic translocation of Dnmt3a, but not Dnmt1 or Dnmt3b, was shown under hyperglycaemia (Supplementary Figure S1B, Figures 2B and 2C), suggesting that the nuclear import of Dnmt3a, which is required for Dnmt3a to methylate DNA, is the key factor that control high glucose-induced reduction in CTGF methylation.