title: Transgenic myocardial overexpression of prokineticin receptor-2 (GPR73b) induces hypertrophy and capillary vessel leakage.
abstract: OBJECTIVE
  Prokineticins are small secreted bioactive molecules. They exert their biological activity by binding to two G protein-coupled receptors. Previously, we have shown that the overexpression of prokineticin receptor-1 (PKR1) in transgenic (TG) mouse hearts induced neovascularization. Since PKR1 and PKR2 are 85% identical and expressed in cardiovascular tissues, we hypothesized that PKR2 may also contribute to cardiomyocyte growth and vascularization.
  
  
  RESULTS
  We have generated TG mice overexpressing PKR2 in cardiomyocytes. TG mice exhibit increased hypertrophic gene expression and heart-to-body weight ratio accompanied by an increased length of cardiomyocytes at the age of 12 weeks. Increased left ventricular end-systolic and diastolic diameters without cardiac dysfunction at the age of 24 weeks indicate that TG mice have an eccentric hypertrophy with compensated cardiac function. Quantitative morphological analysis showed that TG hearts have a normal microvessel density and number of branch points. However, they exhibit increased abnormal endothelial cell shape and ultrastructure, changed cellular distribution of a tight junction protein zona occludens-1 (ZO-1), and vascular leakage in heart without a rise of angiogenic factor levels at early and late age. The application of media conditioned by H9c2 cardioblast cells overexpressing PKR2 significantly induced impaired ZO-1 localization in H5V endothelial cells, mimicking the TG model.
  
  
  CONCLUSIONS
  These findings provide the first genetic evidence that cardiomyocyte PKR2 signalling leads to eccentric hypertrophy in an autocrine regulation and impaired endothelial integrity in a paracrine regulation without inducing angiogenesis. These TG mice may provide a new genetic model for heart diseases.
authors.affiliation: CNRS/ULP, UMR 7175-LC1, Ecole Supérieure de Biotechnologie de Strasbourg, Bld. Sébastien Brandt BP. 10413, F-67412 Illkirch, France.
authors.forename: Kyoji
authors.initials: K
authors.lastname: Urayama
authors.forename: Deniz B
authors.initials: DB
authors.lastname: Dedeoglu
authors.forename: Célia
authors.initials: C
authors.lastname: Guilini
authors.forename: Stefan
authors.initials: S
authors.lastname: Frantz
authors.forename: Georg
authors.initials: G
authors.lastname: Ertl
authors.forename: Nadia
authors.initials: N
authors.lastname: Messaddeq
authors.forename: Canan G
authors.initials: CG
authors.lastname: Nebigil
mesh_terms: D000818:Animals; D001160:Arterioles / Q000473:pathology / Q000503:physiopathology; D001794:Blood Pressure / Q000502:physiology; D019559:Capillary Leak Syndrome / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D006332:Cardiomegaly / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D002463:Cell Membrane Permeability / Q000502:physiology; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000473:pathology / Q000503:physiopathology; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000473:pathology / Q000503:physiopathology; D006339:Heart Rate / Q000502:physiology; D051379:Mice; D008822:Mice, Transgenic; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D032383:Myocytes, Cardiac / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology
chemical_list: C525016:PKR2 protein, mouse; D043562:Receptors, G-Protein-Coupled