38 The observed changes in hepatocellular morphology with increased hepatocyte and nuclear diameter, and nuclear to hepatocyte diameter ratios that persisted with treatment, are novel, and
differ from previously reported data in the LEC rat where they responded to Cu chelation therapy.23 Nuclear and cellular hepatocyte enlargement, which in general are associated with chronic hepatitis with hepatocyte enzymatic activation,39 selleckchem is well known in humans with WD1, 40 and in animal models of this condition3, 23 but the response to Cu chelation treatment has not been consistently described.41 Prior studies on the effects of betaine included its down-regulation of selected ethanol-induced ER stress-related genes Grp78 and Srebp1c in mice,42 that Ppara promoter methylation in offspring was affected by maternal dietary betaine in rats,43 and that the Cpt1A promoter is hypermethylated
in human embryonic stem cells.44 Although both PCA and betaine treatments were associated with increased https://www.selleckchem.com/products/bay80-6946.html global DNA methylation in our study, betaine treatment achieved significant down-regulation of selected ER stress and fatty acid oxidation related transcripts only in control mice, i.e., specifically in the absence of inflammation and Cu accumulation. Increased methylation of promoter CpG islands has been correlated with gene silencing, and may be occurring in our control mice with normally saturated levels of DNA methylation following betaine treatment. In contrast, gene body and intergenic methylation were unsaturated in the global hypomethylated state that we observed in the tx-j mouse livers, so increasing the availability of methyl groups can be predicted to target nonpromoter methylation sites associated with increased gene expression levels.45 Of note, the directions and magnitude of changes in proteins levels for the studied genes were generally similar to those in transcript levels. It is possible that the observed
differences between messenger RNA (mRNA) and protein levels of several of the studied genes could be attributed to Dehydratase posttranslational modifications. In summary, WD appears to be a condition associated with increased demand for methyl groups due to both increased levels of the methylation inhibitor SAH, which is based on the inhibitory effect of Cu on SAHH as shown by its activation after PCA chelation, and also due to chronic inflammatory status (Supporting Fig.). Our results demonstrate reduced SAHH levels in a mouse model of WD that is characterized by Cu accumulation and hepatic inflammation in the early phases of liver damage. The consequent elevation of liver SAH as a result of SAHH inhibition, and the concomitant inflammation, were associated with down-regulation of Dnmt3b and global DNA hypomethylation.