title: Adiponectin levels and expression of adiponectin receptors in isolated monocytes from overweight patients with coronary artery disease.
abstract: BACKGROUND
  Adiponectin has insulin-sensitizing and anti-atherosclerotic effects, partly mediated through its action on monocytes. We aimed to determine adiponectin levels and expression of its receptors (AdipoR1 and AdipoR2) in peripheral monocytes from overweight and obese patients with coronary artery disease (CAD).
  
  
  METHODS
  Fifty-five overweight/obese patients, suspected for CAD, underwent coronary angiography: 31 were classified as CAD patients (stenosis ≥ 50% in at least one main vessel) and 24 as nonCAD. Quantitative RT-PCR and flow cytometry were used for determining mRNA and protein surface expression of adiponectin receptors in peripheral monocytes. A high sensitivity multiplex assay (xMAP technology) was used for the determination of plasma adiponectin and interleukin-10 (IL-10) secreted levels.
  
  
  RESULTS
  Plasma adiponectin levels were decreased in CAD compared to nonCAD patients (10.9 ± 3.1 vs. 13.8 ± 5.8 μg/ml respectively, p = 0.033). In multivariable analysis, Matsuda index was the sole independent determinant of adiponectin levels. AdipoR1 and AdipoR2 protein levels were decreased in monocytes from CAD compared to nonCAD patients (59.5 ± 24.9 vs. 80 ± 46 and 70.7 ± 39 vs. 95.6 ± 47.8 Mean Fluorescence Intensity Arbitrary Units respectively, p < 0.05). No significant differences were observed concerning the mRNA levels of the adiponectin receptors between CAD and nonCAD patients. AdipoR2 protein levels were positively correlated with plasma adiponectin and Matsuda index (r = 0.36 and 0.31 respectively, p < 0.05 for both). Furthermore, basal as well as adiponectin-induced IL-10 release was reduced in monocyte-derived macrophages from CAD compared to nonCAD subjects.
  
  
  CONCLUSIONS
  Overweight patients with CAD compared to those without CAD, had decreased plasma adiponectin levels, as well as decreased surface expression of adiponectin receptors in peripheral monocytes. This fact together with the reduced adiponectin-induced IL-10 secretion from CAD macrophages could explain to a certain extent, an impaired atheroprotective action of adiponectin.
authors.affiliation: Hellenic National Center for the Research, Prevention and Treatment of Diabetes Mellitus and its Complications (HNDC), Athens, Greece.
authors.forename: Anastasios
authors.initials: A
authors.lastname: Kollias
authors.forename: Panayoula C
authors.initials: PC
authors.lastname: Tsiotra
authors.forename: Ignatios
authors.initials: I
authors.lastname: Ikonomidis
authors.forename: Eirini
authors.initials: E
authors.lastname: Maratou
authors.forename: Panayota
authors.initials: P
authors.lastname: Mitrou
authors.forename: Erifyli
authors.initials: E
authors.lastname: Kyriazi
authors.forename: Eleni
authors.initials: E
authors.lastname: Boutati
authors.forename: John
authors.initials: J
authors.lastname: Lekakis
authors.forename: Theofanis
authors.initials: T
authors.lastname: Economopoulos
authors.forename: Dimitrios T
authors.initials: DT
authors.lastname: Kremastinos
authors.forename: George
authors.initials: G
authors.lastname: Dimitriadis
authors.forename: Sotirios A
authors.initials: SA
authors.lastname: Raptis
mesh_terms: D052242:Adiponectin / Q000097:blood; D000368:Aged; D016022:Case-Control Studies; D002478:Cells, Cultured; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000097:blood* / Q000150:complications / Q000000981:diagnostic imaging; D005260:Female; D005434:Flow Cytometry; D006115:Greece; D006801:Humans; D007118:Immunoassay; D016753:Interleukin-10 / Q000097:blood; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000378:metabolism*; D050177:Overweight / Q000097:blood* / Q000150:complications; D012333:RNA, Messenger / Q000097:blood; D054419:Receptors, Adiponectin / Q000097:blood* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012720:Severity of Illness Index
chemical_list: C499918:ADIPOQ protein, human; C475418:ADIPOR1 protein, human; C475420:ADIPOR2 protein, human; D052242:Adiponectin; C508609:IL10 protein, human; D012333:RNA, Messenger; D054419:Receptors, Adiponectin; D016753:Interleukin-10