title: Compare the effect of eicosapentaenoic acid and oxidized low-density lipoprotein on the expression of CD36 and peroxisome proliferator-activated receptor gamma.
abstract: BACKGROUND
  There is evidence that CD36 promotes foam cell formation through internalizing oxidized LDL (ox-LDL) into macrophages; therefore, it plays a key role in pathogenesis of atherosclerosis. In addition, CD36 expression seems to be mediated by nuclear receptor peroxisome proliferator-activated receptor gamma (PPAR-γ). The aim of the present study was to evaluate and compare the effect of PPAR-γ ligands, eicosapentaenoic acid (EPA) as an anti-atherogenic factor and ox-LDL as an atherogenic factor on CD36 expression. Mechanism of PPAR- γ action and its ligands in CD36 expression were also investigated.
  
  
  METHODS
  Raw 264.7 macrophage cell line was treated with ox-LDL (100 and 150 μg protein/LDL) and EPA (100 and 200 μM) for 24 and 48 hours in absence or presence of PPAR-γ inhibitor, T0070907. Quantitative real-time PCR and Western-blotting were used for analysis of gene and protein expression, respectively.
  
  
  RESULTS
  Raw 264.7 exposures to ox-LDL and EPA resulted in increased expression of CD36 mRNA and protein; however, mRNA and PPAR-γ protein were not up-regulated significantly. Pre-incubation of cells with T0070907 led to decreased expression of CD36 when treated with ox-LDL and EPA.
  
  
  CONCLUSIONS
  It was confirmed that both EPA and ox-LDL increased CD36 expression but not PPAR-γ, and also co-treatment with PPAR-γ inhibitor decreased CD36 expression. We concluded that up-regulation of CD36 depends on PPAR-γ activation and is not related to increased expression of PPAR-γ. Induction of CD36 by EPA showed that CD36 suppression is not the means by which ω-3 fatty acids (EPA) provide protection against formation of atherosclerotic plaque.
authors.affiliation: Dept. of Clinical Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Babaahmadi Rezaei
authors.forename: Mahmood
authors.initials: M
authors.lastname: Doosti
authors.forename: Mahdi
authors.initials: M
authors.lastname: Aminian
authors.forename: Parisa
authors.initials: P
authors.lastname: Shabani
mesh_terms: D000818:Animals; D001549:Benzamides / Q000494:pharmacology; D018955:CD36 Antigens / Q000235:genetics* / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D015118:Eicosapentaenoic Acid / Q000494:pharmacology*; D006801:Humans; D008077:Lipoproteins, LDL / Q000494:pharmacology*; D051379:Mice; D047495:PPAR gamma / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics
chemical_list: D001549:Benzamides; D018955:CD36 Antigens; D008077:Lipoproteins, LDL; D047495:PPAR gamma; D011725:Pyridines; D012333:RNA, Messenger; C458508:T 0070907; C099252:oxidized low density lipoprotein; D015118:Eicosapentaenoic Acid