Epigenetic changes of the thioredoxin system in the tx-j mouse model and in patients with Wilson disease
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ABSTRACT: Wilson disease (WD) is caused by mutations in the copper transporter ATP7B, leading to copper accumulation in the liver and brain. Excess copper inhibits S-adenosyl-L-homocysteine hydrolase, leading to variable WD phenotypes from widespread alterations in DNA methylation and gene expression. Previously, we demonstrated that maternal choline supplementation in the Jackson toxic milk (tx-j) mouse model of WD corrected higher thioredoxin 1 transcript levels in fetal liver. Here, we investigated the effect of maternal choline supplementation on genome-wide DNA methylation patterns in tx-j fetal liver by whole-genome bisulfite sequencing (WGBS). Tx-j Atp7b genotype-dependent differences in DNA methylation were corrected by choline for genes including, but not exclusive to, oxidative stress pathways. To examine phenotypic effects of postnatal choline supplementation, tx-j mice were randomized to one of six treatment groups: with or without maternal and/or continued choline supplementation, and with or without copper chelation with penicillamine (PCA) treatment. Hepatic transcript levels of thioredoxin 1 and peroxiredoxin 1 were significantly higher in mice receiving maternal and continued choline with or without PCA treatment compared to untreated mice. A comparison of WGBS of human WD liver compared to tx-j mouse liver demonstrated a significant overlap of differentially-methylated genes associated with ATP7B deficiency. Further, eight genes in the thioredoxin pathway were differentially methylated in human WD liver samples. In summary, Atp7b deficiency and choline supplementation have a genome-wide impact, including on thioredoxin system-related genes, in tx-j mice. These findings could explain the variability of WD phenotype and suggest new complementary treatment options for WD.
ORGANISM(S): Mus musculus
PROVIDER: GSE117592 | GEO | 2018/07/25
REPOSITORIES: GEO
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