title: Elevated glucose inhibits VEGF-A-mediated endocardial cushion formation: modulation by PECAM-1 and MMP-2.
abstract: Atrioventricular (AV) septal defects resulting from aberrant endocardial cushion (EC) formation are observed at increased rates in infants of diabetic mothers. EC formation occurs via an epithelial-mesenchymal transformation (EMT), involving transformation of endocardial cells into mesenchymal cells, migration, and invasion into extracellular matrix. Here, we report that elevated glucose inhibits EMT by reducing myocardial vascular endothelial growth factor A (VEGF-A). This effect is reversed with exogenous recombinant mouse VEGF-A165, whereas addition of soluble VEGF receptor-1 blocks EMT. We show that disruption of EMT is associated with persistence of platelet endothelial cell adhesion molecule-1 (PECAM-1) and decreased matrix metalloproteinase-2 (MMP-2) expression. These findings correlate with retention of a nontransformed endocardial sheet and lack of invasion. The MMP inhibitor GM6001 blocks invasion, whereas explants from PECAM-1 deficient mice exhibit MMP-2 induction and normal EMT in high glucose. PECAM-1-negative endothelial cells are highly motile and express more MMP-2 than do PECAM-1-positive endothelial cells. During EMT, loss of PECAM-1 similarly promotes single cell motility and MMP-2 expression. Our findings suggest that high glucose-induced inhibition of AV cushion morphogenesis results from decreased myocardial VEGF-A expression and is, in part, mediated by persistent endocardial cell PECAM-1 expression and failure to up-regulate MMP-2 expression.
authors.affiliation: Department of Pathology, Yale University School of Medicine, New Haven, CT 06520-8023, USA.
authors.forename: Josephine M
authors.initials: JM
authors.lastname: Enciso
authors.forename: Dita
authors.initials: D
authors.lastname: Gratzinger
authors.forename: Todd D
authors.initials: TD
authors.lastname: Camenisch
authors.forename: Sandra
authors.initials: S
authors.lastname: Canosa
authors.forename: Emese
authors.initials: E
authors.lastname: Pinter
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Madri
mesh_terms: D043925:Angiogenesis Inducing Agents / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002465:Cell Movement / Q000502:physiology; D048429:Cell Size; D002478:Cells, Cultured; D046508:Culture Techniques; D004151:Dipeptides / Q000378:metabolism; D004622:Embryo, Mammalian / Q000033:anatomy & histology / Q000502:physiology; D004694:Endocardial Cushion Defects; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006321:Heart / Q000196:embryology*; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D009024:Morphogenesis; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D011480:Protease Inhibitors / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000378:metabolism
chemical_list: D043925:Angiogenesis Inducing Agents; D004151:Dipeptides; C078131:N-(2(R)-2-(hydroxamidocarbonylmethyl)-4-methylpentanoyl)-L-tryptophan methylamide; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D011480:Protease Inhibitors; D011993:Recombinant Fusion Proteins; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; D040281:Vascular Endothelial Growth Factor Receptor-1; D020778:Matrix Metalloproteinase 2; D005947:Glucose