Modulation of paraoxonase 1 and 3 expression after moderate exercise training in the rat

Rita Romani,Gianna Evelina De Medio,Simona Di Tullio,Rosa Lapalombella,Irene Pirisinu,Vittoria Margonato,Arsenio Veicsteinas,Marina Marini,Gabriella Rosi

doi:10.1194/jlr.m800493-jlr200

Abstract

Paraoxonases (PONs) are a small family of antioxidant enzymes whose antiatherogenic activity is well known. The aim of the present study was the evaluation of the effects of moderate aerobic training on their expression using a rat model. In order to discriminate between PON1 and PON3 enzymatic activity, we took advantage of some differences in their substrate preferences. PON1 and PON3 enzymatic activities and their protein levels were analyzed in plasma and in liver microsomes, and their mRNA levels in the liver. Exercise training did not affect PON1 expression or enzymatic activity but increased PON3 mRNA, protein levels, and enzymatic activity. Training also induced variations in plasma membrane composition, including an increase in polyunsaturated and a decrease in mono- and di-unsaturated fatty acids. On the other hand, acute exercise inhibited PON activities while increasing PON3 protein content in liver microsomes and reversing the relative composition in mono-, di-, and poly-unsaturated fatty acids, suggesting that physical stress, by altering membrane composition, may impair PON release from liver membranes. In conclusion, we documented, for the first time, the presence of PON3 in rat serum and, notably, found that the upregulation of PON3, rather than PON1, appears to be associated with physical training.

Highlights

Paraoxonases (PONs) are a small family of antioxidant enzymes whose antiatherogenic activity is well known
The aim of this study was to provide evidence that moderate aerobic physical exercise could be beneficial for organisms by modulation of PON expressions
While accumulating data that confirmed our hypothesis, we unexpectedly documented for the first time the presence of PON3 in rat plasma by finding that the upregulation of PON3 rather than PON1 appears to be associated with physical training

Summary

Introduction

Paraoxonases (PONs) are a small family of antioxidant enzymes whose antiatherogenic activity is well known. Acute exercise inhibited PON activities while increasing PON3 protein content in liver microsomes and reversing the relative composition in mono-, di-, and poly-unsaturated fatty acids, suggesting that physical stress, by altering membrane composition, may impair PON release from liver membranes. Regular physical activity has been identified as a protective factor against the occurrence and progression of coronary heart disease; it is associated with reduced blood pressure, maintenance of ideal body weight, improvement of lipid profile, and decrease in incidence of type II diabetes [1,2,3]. Evidence suggests that sustained physical activity has beneficial effects on lipoprotein metabolism, including a decrease in plasma triglyceride levels and an increase in HDL-cholesterol concentration, which bears antioxidant properties and protective effects in the prevention of coronary artery disease [4].

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