Figure 3
Hypoxic preconditioning represses p53 and up-regulates DNA methyltransferases via the PI3K/Akt pathway.
(a) Representative Western blots of p53, DNMT1, DNMT3α and DNMT3β protein expression in CPCs. β-Actin was used as a loading control. p53 expression was markedly reduced by HP. DNMT1 and DNMT3β expression levels were significantly up-regulated by HP. DNMT3α expression was unchanged in all 6 groups. (b) q-PCR analysis of the mRNA expression of p53, DNMT1 and DNMT3β. Relative gene expression levels were calculated via normalization to GAPDH. HP reduced the mRNA level of p53 and up-regulated DNMT1 and DNMT3β. Data were obtained from three independent experiments under the same experimental conditions and are expressed as the mean ± SD. *P < 0.05 vs. H0 + 24 h. **P < 0.01 vs. H0+24 h. #P < 0.05 vs. H6+24 h. ##P < 0.01 vs. H6+24 h. H0, normoxia. H0+24 h, normoxia + oxygen–serum deprivation for 24 hours. H0+IGF+24 h, normoxia with IGF-1 + oxygen–serum deprivation for 24 hours. H6, HP for 6 hours. H6+24 h, HP for 6 hours + oxygen–serum deprivation for 24 hours. H6+LY+24 h, HP for 6 hours with LY294002 + oxygen–serum deprivation for 24 hours. NS, not significant.
