Hepatic methionine metabolism may play an essential role in regulating methylation status and liver injury in Wilson's disease (WD) through the inhibition of S-adenosylhomocysteine hydrolase (SAHH) by copper (Cu) and the consequent accumulation of S-adenosylhomocysteine (SAH). We studied the transcript levels of selected genes related to liver injury, levels of SAHH, SAH, DNA methyltransferases genes (
Dnmt1, Dnmt3a, Dnmt3b
), and global DNA methylation in the tx-j mouse (tx-j), an animal model of WD. Findings were compared to those in control C3H mice, and in response to Cu chelation by penicillamine (PCA) and dietary supplementation of the methyl donor betaine to modulate inflammatory and methylation status. Transcript levels of selected genes related to endoplasmic reticulum stress, lipid synthesis, and fatty acid oxidation were down-regulated at baseline in tx-j mice, further down-regulated in response to PCA, and showed little to no response to betaine. Hepatic
Sahh
transcript and protein levels were reduced in tx-j mice with consequent increase of SAH levels. Hepatic Cu accumulation was associated with inflammation, as indicated by histopathology and elevated serum alanine aminotransferase (ALT) and liver tumor necrosis factor alpha (
Tnf
-α) levels.
Dnmt3b
was down-regulated in tx-j mice together with global DNA hypomethylation. PCA treatment of tx-j mice reduced
Tnf
-α and ALT levels, betaine treatment increased S-adenosylmethionine and up-regulated
Dnmt3b
levels, and both treatments restored global DNA methylation levels. Conclusion: Reduced hepatic
Sahh
expression was associated with increased liver SAH levels in the tx-j model of WD, with consequent global DNA hypomethylation. Increased global DNA methylation was achieved by reducing inflammation by Cu chelation or by providing methyl groups. We propose that increased SAH levels and inflammation affect widespread epigenetic regulation of gene expression in WD.
Background: Metabolic syndrome affects 1 in 3 U.S. adults. The primary target of treatment of patients with metabolic syndrome is therapeutic lifestyle change. Numerous animal trials have reported positive effects of Aloe vera in in vivo models of diabetes, but there is a paucity of controlled clinical trials in patients with prediabetes. Thus, the objective of this pilot study was to examine the effect of aloe compared to placebo on fasting blood glucose, lipid profile, and oxidative stress in subjects with prediabetes/metabolic syndrome. Methods: This was a double-blind, placebo-controlled Institutional Review Board (IRB)–approved pilot study of two aloe products (UP780 and AC952) in patients with prediabetes over an 8-week period. A total of 45 subjects with impaired fasting glucose or impaired glucose tolerance and having two other features of metabolic syndrome were recruited (n=15/group). Parameters of glycemia [fasting glucose, insulin, homeostasis model assessment (HOMA), glycosylated hemoglobin (HbA1c), fructosamine, and oral glucose tolerance test (OGTT)] and oxidative stress (urinary F2-isoprostanes) were measured along with lipid profile and high-sensitivity C-reactive protein (hsCRP) levels before and after supplementation. Results: There were no significant baseline differences between groups. Compared to placebo, only the AC952 Aloe vera inner leaf gel powder resulted in significant reduction in total and low-density lipoprotein cholesterol (LDL-C) levels, glucose, and fructosamine. In the UP780 Aloe vera inner leaf gel powder standardized with 2% aloesin group, there were significant reductions in HbA1c, fructosamine, fasting glucose, insulin, and HOMA. Only the UP780 aloe group had a significant reduction in the F2-isoprostanes compared to placebo. Conclusions: Standardized aloe preparations offer an attractive adjunctive strategy to revert the impaired fasting glucose and impaired glucose tolerance observed in conditions of prediabetes/metabolic syndrome.