Cardiovascular pharmacology Resveratrol mediates anti-atherogenic effects on cholesterol flux in human macrophages and endothelium via PPARg and adenosine Iryna Voloshyna n , Ofek Hai, Michael J. Littlefield, Steven Carsons, Allison B. Reiss Winthrop Research Institute, Department of Medicine, Winthrop University Hospital, 222 Station Plaza, North, Suite 511B, Mineola, NY 11501, USA article info Article history: Received 19 April 2012 Received in revised form 15 August 2012 Accepted 27 August 2012 Available online 4 October 2012 Keywords: Atherosclerosis Anti-atherogenic function Adenosin 2A receptor PPAR-g Resveratrol Reverse cholesterol transport Scavenger receptor abstract Resveratrol is a bioactive molecule used in dietary supplements and herbal medicines and consumed worldwide. Known cardioprotective and anti-inflammatory properties of resveratrol have spurred investigation of the mechanisms involved. The present study explored potential atheroprotective actions of resveratrol on cholesterol metabolism in cells of the arterial wall, including human macrophages and arterial endothelium. Using QRT-PCR and Western blotting techniques, we measured expression of the proteins involved in reverse cholesterol transport (ABCA1, ABCG1 and SR-B1) and the scavenger receptors responsible for uptake of modified cholesterol (CD36, SR-A1 and LOX-1). We analyzed the effect of resveratrol on apoA-1-and HDL-mediated cholesterol efflux in human THP-1 macrophages. The effect of resveratrol on oxLDL internalization and foam cell formation were evaluated using confocal and light microscopy. Our data indicate that resveratrol regulates expression of major proteins involved in cholesterol transport, promotes apoA-1 and HDL-mediated efflux, downregulates oxLDL uptake and diminishes foam cell formation. Mechanistically, resveratrol effects were dependent upon PPAR-g and adenosine 2A receptor pathways. For the first time we demonstrate that resveratrol regulates expression of the cholesterol metabolizing enzyme cytochrome P450 27-hydroxylase, providing efficient cholesterol elimination via formation of oxysterols. This study establishes that resveratrol attenuates lipid accumulation in cultured human macrophages via effects on cholesterol transport. Further in vivo studies are needed to determine whether resveratrol may be an additional resource available to reduce lipid deposition and atherosclerosis in humans. Published by Elsevier B.V. 1. Introduction Over the last decade, the search for natural compounds with the ability to prevent cholesterol accumulation in macrophages has been a main focus for many investigators. Several lines of evidence suggest that resveratrol (3,5,4 0 -trihydroxystilbene), a plant-derived polyphe- nol and phytoalexin, exhibits cardioprotective and anti-inflammatory properties (Fan et al., 2008; Palmieri et al., 2011; Prasad, 2010; Zhu et al., 2011). Current study explores its potential atheroprotective impact on cholesterol efflux and influx in cells of the arterial wall, including macrophages and arterial endothelium. The balanced flow of cholesterol into and out of the macrophage is necessary to avoid lipid overload, and ultimately, atheroma development (Tabas, 2002). Cholesterol efflux from cells of the arterial wall to extracellular acceptors involves the ATP binding cassette transporters (ABC) A1 and G1 (Voloshyna and Reiss, 2011). ABCA1 promotes the transfer of cholesterol and phospholipids to lipid-poor apolipoprotein (apo) A-1 (Oram et al., 2001; Rust et al., 1999) contributing to the formation of high-density lipopro- teins (HDL) in the liver. ABCG1 is critically involved in regulation of lipid-trafficking mechanisms in macrophages and participates in net efflux of cellular free cholesterol (FC) and phospholipid to lipid-free HDL (Wang et al., 2004). Expressions of ABCA1, ABCG1 and apolipoprotein E (apoE) are mediated through the nuclear receptors, liver X receptor (LXR) a and peroxisome-proliferator-activated receptor (PPAR) g (Chawla et al., 2001; Ricote et al., 2004). Scavenger receptor class B type I (SR-BI)-mediated cholesterol efflux occurs as a bidirectional flux to phospholipid-containing acceptors (HDL and lipidated apolipoproteins), which depends on the gradient of FC (Yancey et al., 2003). Synthesis of 27-hydroxycholesterol by the mitochondrial cyto- chrome P450 27-hydroxylase (CYP27A1) in arterial endothelium and macrophages provides a pathway for elimination of intracel- lular cholesterol. 27-hydroxycholesterol has statin-like proper- ties, potently inhibiting HMG CoA reductase, suppressing smooth muscle cell proliferation and diminishing macrophage foam cell formation (Babiker et al., 1997; Reiss et al., 2000). An increase in 27-hydroxylase expression promotes cholesterol elimination both directly (by catabolism of cholesterol) and indirectly (by modula- tion of ABCA1 and apoE expression). Contents lists available at SciVerse ScienceDirect journal homepage: www.elsevier.com/locate/ejphar European Journal of Pharmacology 0014-2999/$ - see front matter Published by Elsevier B.V. http://dx.doi.org/10.1016/j.ejphar.2012.08.024 n Corresponding author. Tel. þ1 516 663 4664; fax. þ1 516 663 4710. E-mail address: IVoloshyna@Winthrop.org (I. Voloshyna). European Journal of Pharmacology 698 (2013) 299–309