RESUMO
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 (TNX1) 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 TXN1 and peroxiredoxin 1 (Prdx1) were significantly higher in mice receiving maternal and continued choline with or without PCA treatment compared to untreated mice. A WGBS comparison of human WD liver and tx-j mouse liver demonstrated a significant overlap of differentially methylated genes associated with ATP7B deficiency. Further, eight genes in the thioredoxin (TXN) pathway were differentially methylated in human WD liver samples. In summary, Atp7b deficiency and choline supplementation have a genome-wide impact, including on TXN system-related genes, in tx-j mice. These findings could explain the variability of WD phenotype and suggest new complementary treatment options for WD.
Assuntos
ATPases Transportadoras de Cobre/genética , Epigênese Genética/genética , Degeneração Hepatolenticular/genética , Peroxirredoxinas/genética , Tiorredoxinas/genética , Animais , Quelantes/administração & dosagem , Colina/administração & dosagem , Cobre/administração & dosagem , Metilação de DNA/genética , Modelos Animais de Doenças , Epigênese Genética/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Degeneração Hepatolenticular/tratamento farmacológico , Degeneração Hepatolenticular/patologia , Humanos , Fígado/efeitos dos fármacos , Fígado/patologia , Herança Materna , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Penicilamina/administração & dosagem , Gravidez , Transdução de Sinais/efeitos dos fármacos , Sequenciamento Completo do GenomaRESUMO
Augmented maternal care during the first postnatal week promotes life-long stress resilience and improved memory compared with the outcome of routine rearing conditions. Recent evidence suggests that this programming commences with altered synaptic connectivity of stress sensitive hypothalamic neurons. However, the epigenomic basis of the long-lived consequences is not well understood. Here, we employed whole-genome bisulfite sequencing (WGBS), RNA-sequencing (RNA-seq), and a multiplex microRNA (miRNA) assay to examine the effects of augmented maternal care on DNA cytosine methylation, gene expression, and miRNA expression. A total of 9,439 differentially methylated regions (DMRs) associated with augmented maternal care were identified in male offspring hypothalamus, as well as a modest but significant decrease in global DNA methylation. Differentially methylated and expressed genes were enriched for functions in neurotransmission, neurodevelopment, protein synthesis, and oxidative phosphorylation, as well as known stress response genes. Twenty prioritized genes were identified as highly relevant to the stress resiliency phenotype. This combined unbiased approach enabled the discovery of novel genes and gene pathways that advance our understanding of the epigenomic mechanisms underlying the effects of maternal care on the developing brain.
Assuntos
Metilação de DNA/genética , Desenvolvimento Embrionário/genética , Epigenômica , Hipotálamo/crescimento & desenvolvimento , Animais , Ilhas de CpG/genética , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento/genética , Humanos , Hipotálamo/metabolismo , Masculino , MicroRNAs/genética , Relações Mãe-Filho , Plasticidade Neuronal/genética , Ratos , Análise de Sequência de DNA , Análise de Sequência de RNA , Estresse Psicológico/genética , Sequenciamento Completo do GenomaRESUMO
Rhythmic oscillations of physiological processes depend on integrating the circadian clock and diurnal environment. DNA methylation is epigenetically responsive to daily rhythms, as a subset of CpG dinucleotides in brain exhibit diurnal rhythmic methylation. Here, we show a major genetic effect on rhythmic methylation in a mouse Snord116 deletion model of the imprinted disorder Prader-Willi syndrome (PWS). More than 23,000 diurnally rhythmic CpGs are identified in wild-type cortex, with nearly all lost or phase-shifted in PWS. Circadian dysregulation of a second imprinted Snord cluster at the Temple/Kagami-Ogata syndrome locus is observed at the level of methylation, transcription, and chromatin, providing mechanistic evidence of cross-talk. Genes identified by diurnal epigenetic changes in PWS mice overlapped rhythmic and PWS-specific genes in human brain and are enriched for PWS-relevant phenotypes and pathways. These results support the proposed evolutionary relationship between imprinting and sleep, and suggest possible chronotherapy in the treatment of PWS and related disorders.