Circulation Research; co-auth.: B. Desvergne

Circ Res. 2010 Apr 8.

Induction of Cardiac Angptl4 by Dietary Fatty Acids Is Mediated by Peroxisome Proliferator-Activated Receptor {beta}/{delta} and Protects Against Fatty Acid-Induced Oxidative Stress.

Georgiadi A, Lichtenstein L, Degenhardt T, Boekschoten M, van Bilsen M, Desvergne B, Müller M, Kersten S.

Nutrition, Metabolism and Genomics Group, Division of Human Nutrition, Wageningen University. The Netherlands; Nutrigenomics Consortium, TI Food and Nutrition, Wageningen, The Netherlands; Department of Biochemistry, University of Kuopio, Finland; Department of Physiology, Maastricht University, The Netherlands; and Centre Intégrative Génomique, University of Lausanne, Switzerland.

Abstract

Rationale: Although dietary fatty acids are a major fuel for the heart, little is known about the direct effects of dietary fatty acids on gene regulation in the intact heart. Objective: To study the effect of dietary fatty acids on cardiac gene expression and explore the functional consequences. Methods and Results: Oral administration of synthetic triglycerides composed of one single fatty acid alters cardiac expression of numerous genes, many of which are involved in the oxidative stress response. The gene most significantly and consistently upregulated by dietary fatty acids encoded Angiopoietin-like protein (Angptl)4, a circulating inhibitor of lipoprotein lipase expressed by cardiomyocytes. Induction of Angptl4 by the fatty acid linolenic acid was specifically abolished in peroxisome proliferator-activated receptor (PPAR)beta/delta(-/-) and not PPARalpha(-/-) mice and was blunted on siRNA-mediated PPARbeta/delta knockdown in cultured cardiomyocytes. Consistent with these data, linolenic acid stimulated binding of PPARbeta/delta but not PPARalpha to the Angptl4 gene. Upregulation of Angptl4 resulted in decreased cardiac uptake of plasma triglyceride-derived fatty acids and decreased fatty acid-induced oxidative stress and lipid peroxidation. In contrast, Angptl4 deletion led to enhanced oxidative stress in the heart, both after an acute oral fat load and after prolonged high fat feeding. Conclusions: Stimulation of cardiac Angptl4 gene expression by dietary fatty acids and via PPARbeta/delta is part of a feedback mechanism aimed at protecting the heart against lipid overload and consequently fatty acid-induced oxidative stress.

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