title: Adiponectin/T-cadherin and apelin/APJ expression in human arteries and periadventitial fat: implication of local adipokine signaling in atherosclerosis?
abstract: BACKGROUND
  Adipose tissue is considered an endocrine organ, producing bioactive peptides, called adipokines. Adipokines produced by periadventitial fat have been implicated in the pathogenesis of vascular disease, including atherosclerosis. Adiponectin has established antiatherogenic actions, while the role of T-cadherin as an adiponectin receptor is not fully elucidated. The apelinergic system, consisting of apelin and its APJ receptor, is a mediator of various cardiovascular functions and may also be involved in the atherosclerotic process. We investigated the protein expression of adiponectin, T-cadherin, apelin and APJ in human aortas, coronary vessels, and the respective periadventitial adipose tissue and correlated their expression with the presence of atherosclerosis and clinical parameters.
  
  
  METHODS
  Immunohistochemistry for adiponectin, T-cadherin, apelin, and APJ was performed on human aortic and coronary artery samples including the periadventitial adipose tissue. Aortic and coronary atherosclerotic lesions were assessed using the american heart association (AHA) classification.
  
  
  RESULTS
  Adiponectin immunostaining, of varied intensity, was detected only in adipocytes, while T-cadherin was localized to vascular smooth muscle cells (VSMCs) and endothelial cells. Apelin immunostaining was detected in adipocytes, VSMCs, endothelial cells, and foam cells in atherosclerotic lesions, while APJ was found in VSMCs and endothelia. Periadventitial adiponectin and VSMC T-cadherin expression were negatively correlated with atherosclerosis in both sites, as was VSMC apelin expression. Several other - depot specific - associations were observed.
  
  
  CONCLUSIONS
  Our results suggest a possible role for T-cadherin as a mediator of antiatherogenic adiponectin actions, while they support the putative antiatherogenic profile for apelin and its APJ receptor in human arteries. Further research is absolutely necessary to confirm these notions.
  
  
  CONCLUSIONS
  Periadventitial adipose tissue adipokines are implicated in vascular physiology and pathology. Adiponectin/T-cadherin and apelin/APJ immunoreactivity is detected in human aortas and coronary arteries. Adiponectin/T-cadherin and apelin/APJ expression patterns were found to be inversely associated with human aortic and coronary atherosclerosis.
authors.affiliation: Department of Anatomy, School of Medicine, University of Patras, 26500, Rio, Patras, Greece. Electronic address: christos.kst@gmail.com.
authors.forename: Christos G
authors.initials: CG
authors.lastname: Kostopoulos
authors.affiliation: Department of Anatomy, School of Medicine, University of Patras, 26500, Rio, Patras, Greece.
authors.forename: Sofia G
authors.initials: SG
authors.lastname: Spiroglou
authors.affiliation: Department of Anatomy, School of Medicine, University of Patras, 26500, Rio, Patras, Greece.
authors.forename: John N
authors.initials: JN
authors.lastname: Varakis
authors.affiliation: Department of Cardiac Surgery, University Hospital of Ioannina, School of Medicine, University of Ioannina, 45500, Ioannina, Greece.
authors.forename: Efstratios
authors.initials: E
authors.lastname: Apostolakis
authors.affiliation: Department of Anatomy, School of Medicine, University of Patras, 26500, Rio, Patras, Greece.
authors.forename: Helen H
authors.initials: HH
authors.lastname: Papadaki
mesh_terms: D052242:Adiponectin / Q000032:analysis*; D000273:Adipose Tissue / Q000737:chemistry* / Q000473:pathology; D000293:Adolescent; D000328:Adult; D063194:Adventitia / Q000737:chemistry* / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D001012:Aorta, Abdominal / Q000737:chemistry* / Q000473:pathology; D001018:Aortic Diseases / Q000378:metabolism* / Q000473:pathology; D000073861:Apelin; D050197:Atherosclerosis / Q000378:metabolism* / Q000473:pathology; D001344:Autopsy; D015415:Biomarkers / Q000032:analysis; D015820:Cadherins / Q000032:analysis*; D003324:Coronary Artery Disease / Q000378:metabolism* / Q000473:pathology; D003331:Coronary Vessels / Q000737:chemistry* / Q000473:pathology; D042783:Endothelial Cells / Q000737:chemistry / Q000473:pathology; D005260:Female; D005487:Foam Cells / Q000737:chemistry / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D032389:Myocytes, Smooth Muscle / Q000737:chemistry / Q000473:pathology; D058226:Plaque, Atherosclerotic; D011379:Prognosis; D015398:Signal Transduction; D055815:Young Adult
chemical_list: C499918:ADIPOQ protein, human; C115436:APLN protein, human; D052242:Adiponectin; D000073861:Apelin; D015415:Biomarkers; D015820:Cadherins; C099972:H-cadherin; D036341:Intercellular Signaling Peptides and Proteins
keywords: APJ; Adiponectin; Apelin; Atherosclerosis; Periadventitial adipose tissue; T-cadherin