title: Epicardial perivascular adipose-derived leptin exacerbates coronary endothelial dysfunction in metabolic syndrome via a protein kinase C-beta pathway.
abstract: OBJECTIVE
  Factors released by perivascular adipose tissue (PVAT) disrupt coronary endothelial function via phosphorylation of endothelial NO synthase by protein kinase C (PKC)-beta. However, our understanding of how PVAT potentially contributes to coronary disease as a complication of obesity/metabolic syndrome (MetS) remains limited. The current study investigated whether PVAT-derived leptin impairs coronary vascular function via PKC-beta in MetS.
  
  
  RESULTS
  Coronary arteries with and without PVAT were collected from lean or MetS Ossabaw miniature swine for isometric tension studies. Endothelial-dependent vasodilation to bradykinin was significantly reduced in MetS. PVAT did not affect bradykinin-mediated dilation in arteries from lean swine but significantly exacerbated endothelial dysfunction in arteries from MetS swine. PVAT-induced impairment was reversed by inhibition of either PKC-beta with ruboxistaurin (Eli Lilly and Company, Indianapolis, Ind) or leptin receptor signaling with a recombinant, pegylated leptin antagonist. Western blot and immunohistochemical analyses demonstrated increased PVAT-derived leptin and coronary leptin receptor density with MetS. Coronary PKC-beta activity was increased in both MetS arteries exposed to PVAT and lean arteries exposed to leptin. Finally, leptin-induced endothelial dysfunction was reversed by ruboxistaurin.
  
  
  CONCLUSIONS
  Increases in epicardial PVAT leptin exacerbate coronary endothelial dysfunction in MetS via a PKC-beta-dependent pathway. These findings implicate PVAT-derived leptin as a potential contributor to coronary atherogenesis in MetS.
authors.affiliation: Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Payne
authors.forename: Léna
authors.initials: L
authors.lastname: Borbouse
authors.forename: Sajel
authors.initials: S
authors.lastname: Kumar
authors.forename: Zachary
authors.initials: Z
authors.lastname: Neeb
authors.forename: Mouhamad
authors.initials: M
authors.lastname: Alloosh
authors.forename: Michael
authors.initials: M
authors.lastname: Sturek
authors.forename: Johnathan D
authors.initials: JD
authors.lastname: Tune
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D003331:Coronary Vessels / Q000187:drug effects / Q000201:enzymology* / Q000503:physiopathology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects / Q000201:enzymology* / Q000503:physiopathology; D005260:Female; D020738:Leptin / Q000378:metabolism*; D008297:Male; D024821:Metabolic Syndrome / Q000201:enzymology* / Q000503:physiopathology; D010496:Pericardium; D010641:Phenotype; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D064546:Protein Kinase C beta; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D054411:Receptors, Leptin / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013552:Swine; D013556:Swine, Miniature; D015854:Up-Regulation; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D020738:Leptin; D047428:Protein Kinase Inhibitors; D054411:Receptors, Leptin; D014665:Vasodilator Agents; D011493:Protein Kinase C; D064546:Protein Kinase C beta