Genes Expression And Methylation Analysis Of Nrf2/ARE Signal Pathway In Zebrafish Under H₂O₂ And Dem

The Nrf2/ARE signal pathway is the important defense response system in most organisms.It plays an important role in anti-inflammatory,immune,anti-tumor and other areas.Recent studies have shown that the Nrf2/ARE signal pathway is regulated with many mechanisms.Methylation of the promoter region can also regulate the Nrf2/ARE signal pathway related genes.But the study on the methylation of the whole Nrf2/ARE signal pathway is rarely reported in different conditions.To research whether the Nrf2/ARE signal pathway related genes in zebrafish are regulated by DNA methylation under H₂O₂ ? DEM,we analyzed the expression of the Nrf2/ARE signal pathway related genes with the real-time quantitative PCR.The results showed that the Nrf2/ARE signal pathway is activated and the expression of downstream antioxidant target genes increase under H₂O₂ ? DEM.It also showed that the Nrf2/ARE signal pathway is effective to protect the organisms.Most genes have CpG islands in the promoter region.The result showed that the CpG islands of keap1 b promoter region is low methylated and nrf2 a and mafg2 are complete hypomethylation.It also found the CpG islands of nrf2 b and mafk promoter region are complete hypermethylation under H₂O₂? DEM.At last,the degree of maft methylation decreased significantly under H₂O₂ treatment in 8 hpf and 120 hpf,but the degree of maft methylation decreased significantly under DEM treatment only in 8hpf.In conclusion,the regulatory mechanism of the Nrf2/ARE signal pathway is different in different conditions.maft can regulate its expression by reducing methylation levels in early embryonic and juvenile stages when it is stimulated with H₂O₂ treatment,and thus increase the expression of downstream antioxidant target genes.