The role of lipoprotein-associated enzyme paraoxonase 1 and its polymorphisms in the pathogenesis of endothelial dysfunction and somatic complications in patients with alcoholism: review

Abstract

A review of recent data on the role of the multifunctional enzyme, associated with high density lipoproteins – paraoxonase 1 (PON1) in maintaining healthy endothelial function by detoxifying both oxidized low density lipoproteins and homocysteine thiolactone. The additional contribution to the protection of the endothelium against damage makes organophosphatase activity of PON1 involved in the detoxification products of tobacco smoke. The reduction of antioxidant activity of PON1 promotes the differentiation of monocytes into macrophages and the development of inflammation. The reduction of thiolactonase activity of PON1 is accompanied by a decrease of methionine re-synthesis from homocysteine causing DNA- hypomethylation and alteratioin of the expression patterns of pro- and anti-atherogenic genes. Global hypomethylation of the genome is regarded as one of the three most important mechanisms of the increased risk of somatic complications of alcoholism. The accumulation of homocysteine thiolactone serving agonist of glutamate receptors and antagonist of dopamine receptors is a prerequisite to increased alcohol abuse. Clinical observations focusing on gene polymorphisms of PON indicate that three different genotypes of polymorphism PON1Q192R have unequal degrees atheroprotective properties.