Lack or excess of amino acid methionine can impact liver cells, new research reveals

A new study has found that a diet supplemented with or deficient in methionine impacts the expression of genes associated with level cell fat metabolism as well as genes that modify chromatin.

The study, published in the journal, Food and Chemical Toxicology, was the fourth paper published by the Nutrigenomics Research Group at the University of São Paulo’s Ribeirão Preto School of Pharmaceutical Sciences (FCFRP-USP) in Brazil. This study was in collaboration with the National Center for Toxicological Research, a branch of the United States Food and Drug Administration (FDA).

According to the study, researchers investigated how methionine influences DNA methylation, a biochemical process involving addition of a methyl radical to the DNA molecule. This is an epigenetic change, which  can be repeated in cell division and be transmitted to descendants, although they are not the same as alterations in the DNA sequence (genotype). To investigate the epigenetic mechanisms involved in alterations to liver cells, the researchers fed mice a methionine-deficient or methionine-supplemented diet and then extracted cells from their livers for molecular analysis. 

The findings contribute to a better understanding of the action of compounds present in diet on gene regulation, according to the study, including the impact of diet on microRNAs.

“We observed that diets with inadequate levels of methionine, especially those deficient in the amino acid, can cause dysregulation of several microRNAs that play a significant role in liver homeostasis,” said Lusânia Maria Greggi Antunes, PhD corresponding author of the article and coordinator of the Nutrigenomics Group at FCFRP-USP.