title: Counter regulatory effects of PKCbetaII and PKCdelta on coronary endothelial permeability.
abstract: OBJECTIVE
  The aim of this study was to examine the endothelial distribution and activity of selected PKC isoforms in coronary vessels with respect to their functional impact on endothelial permeability under the experimental conditions relevant to diabetes.
  
  
  RESULTS
  En face immunohistochemistry demonstrated a significant increase of PKC(betaII) and decrease of PKCdelta expression in coronary arterial endothelium of Zucker diabetic rats. To test whether changes in PKC expression alter endothelial barrier properties, we measured the transcellular electric resistance in human coronary microvascular endothelial monolayers and found that either PKC(betaII) overexpression or PKCdelta inhibition disrupted the cell-cell adhesive barrier. Three-dimensional fluorescence microscopy revealed that hyperpermeability was caused by altered PKC activity in association with distinct translocation of PKC(betaII) to the cell-cell junction and PKCdelta localization to the cytosol. Further analyses in fractionated endothelial lysates confirmed the differential redistribution of these isozymes. Additionally, FRET analysis of PKC subcellular dynamics demonstrated a high PKC(betaII) activity at the cell surface and junction, whereas PKCdelta activity is concentrated in intracellular membrane organelles.
  
  
  CONCLUSIONS
  Taken together, these data suggest that PKC(betaII) and PKCdelta counter-regulate coronary endothelial barrier properties by targeting distinctive subcellular sites. Imbalanced PKC(betaII)/PKCdelta expression and activity may contribute to endothelial hyperpermeability and coronary dysfunction in diabetes.
authors.affiliation: Department of Surgery, University of California Davis School of Medicine, 4625 2nd Avenue, Room 3006, Sacramento, CA 95817, USA.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Gaudreault
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Perrin
authors.forename: Mingzang
authors.initials: M
authors.lastname: Guo
authors.forename: Chase P
authors.initials: CP
authors.lastname: Clanton
authors.forename: Mack H
authors.initials: MH
authors.lastname: Wu
authors.forename: Sarah Y
authors.initials: SY
authors.lastname: Yuan
mesh_terms: D000818:Animals; D002199:Capillary Permeability / Q000502:physiology*; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000502:physiology*; D003920:Diabetes Mellitus / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology*; D006801:Humans; D008297:Male; D011493:Protein Kinase C / Q000502:physiology*; D064546:Protein Kinase C beta; D051745:Protein Kinase C-delta / Q000502:physiology*; D051381:Rats; D011924:Rats, Zucker
chemical_list: D011493:Protein Kinase C; D064546:Protein Kinase C beta; D051745:Protein Kinase C-delta