Homocysteine thiolactone and N-homocysteinylated protein induce pro-atherogenic changes in gene expression in human vascular endothelial cells

Abstract

Genetic or nutritional deficiencies in homocysteine (Hcy) metabolism lead to hyperhomocysteinemia (HHcy) and cause endothelial dysfunction, a hallmark of atherosclerosis. In addition to Hcy, related metabolites accumulate in HHcy but their role in endothelial dysfunction is unknown. Here, we examine how Hcy-thiolactone, N-Hcy-protein, and Hcy affect gene expression and molecular pathways in human umbilical vein endothelial cells. We used microarray technology, real-time quantitative polymerase chain reaction, and bioinformatic analysis with PANTHER, DAVID, and Ingenuity Pathway Analysis (IPA) resources. We identified 47, 113, and 30 mRNAs regulated by N-Hcy-protein, Hcy-thiolactone, and Hcy, respectively, and found that each metabolite induced a unique pattern of gene expression. Top molecular pathways affected by Hcy-thiolactone were chromatin organization, one-carbon metabolism, and lipid-related processes [−log(P value) = 20–31]. Top pathways affected by N-Hcy-protein and Hcy were blood coagulation, sulfur amino acid metabolism, and lipid metabolism [−log(P value)] = 4–11; also affected by Hcy-thiolactone, [−log(P value) = 8–14]. Top disease related to Hcy-thiolactone, N-Hcy-protein, and Hcy was ‘atherosclerosis, coronary heart disease’ [−log(P value) = 9–16]. Top-scored biological networks affected by Hcy-thiolactone (score = 34–40) were cardiovascular disease and function; those affected by N-Hcy-protein (score = 24–35) were ‘small molecule biochemistry, neurological disease,’ and ‘cardiovascular system development and function’; and those affected by Hcy (score = 25–37) were ‘amino acid metabolism, lipid metabolism,’ ‘cellular movement, and cardiovascular and nervous system development and function.’ These results indicate that each Hcy metabolite uniquely modulates gene expression in pathways important for vascular homeostasis and identify new genes and pathways that are linked to HHcy-induced endothelial dysfunction and vascular disease.

The Molecular and Cellular Effect of Homocysteine Metabolism Imbalance on Human Health

“…Gurda et al [38] analyzed the changes in gene expression profiles induced by Hcy and its products using microarray technology, real-time quantitative PCR and bioinformatic analysis. They identified 47, 113, and 30 different mRNA regulated by N -homocysteinylated protein, Hcy-TL, and Hcy, respectively.…”

Oxymatrine Inhibits Homocysteine-Mediated Autophagy via MIF/mTOR Signaling in Human Umbilical Vein Endothelial Cells

“…Hcyis an important intermediate in one-carbon metabolism that involves the conversion of methionine to cysteine, and folate interconversions. Deficiencies in these pathways lead to the accumulation of Hcy and its metabolites in the blood, which causes endothelial dysfunction (endothelial cell injury and autophagy) [20-22]. …”

Hyperhomocysteinaemia in rats is associated with erectile dysfunction by impairing endothelial nitric oxide synthase activity

“…This is the most important synthetic path for glutathione, which can protect many ingredients of cells against oxidative damage. A number of studies have shown that HHCy has a wide range of biological effects, such as damaging vascular endothelial cells, activating platelets, and stimulating vascular smooth muscle cell proliferation1213. HHCy has been strongly correlated with vascular dysfunction.…”