Vascular endothelial growth factor-C, a potential paracrine regulator of glomerular permeability, increases glomerular endothelial cell monolayer integrity and intracellular calcium

Am J Pathol. 2008 Oct;173(4):938-48. doi: 10.2353/ajpath.2008.070416. Epub 2008 Sep 4.

Abstract

We have previously reported expression of vascular endothelial growth factor (VEGF)-A and -C in glomerular podocytes and actions of VEGF-A on glomerular endothelial cells (GEnC) that express VEGF receptor-2 (VEGFR-2). Here we define VEGFR-3 expression in GEnC and investigate the effects of the ligand VEGF-C. Renal cortex and cultured GEnC were examined by microscopy, and both cell and glomerular lysates were assessed by Western blotting. VEGF-C effects on trans-endothelial electrical resistance and albumin flux across GEnC monolayers were measured. The effects of VEGF-C156S, a VEGFR-3-specific agonist, and VEGF-A were also studied. VEGF-C effects on intracellular calcium ([Ca2+]i) were measured using a fluorescence technique, receptor phosphorylation was examined by immunoprecipitation assays, and phosphorylation of myosin light chain-2 and VE-cadherin was assessed by blotting with phospho-specific antibodies. GEnC expressed VEGFR-3 in tissue sections and culture, and VEGF-C increased trans-endothelial electrical resistance in a dose-dependent manner with a maximal effect at 120 minutes of 6.8 Omega whereas VEGF-C156S had no effect. VEGF-C reduced labeled albumin flux by 32.8%. VEGF-C and VEGF-A increased [Ca2+]i by 15% and 39%, respectively. VEGF-C phosphorylated VEGFR-2 but not VEGFR-3, myosin light chain-2, or VE-cadherin. VEGF-C increased GEnC monolayer integrity and increased [Ca2+]i, which may be related to VEGF-C-S particular receptor binding and phosphorylation induction characteristics. These observations suggest that podocytes direct GEnC behavior through both VEGF-C and VEGF-A.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, CD / metabolism
  • Cadherins / metabolism
  • Calcium / metabolism*
  • Calcium Signaling / drug effects
  • Cardiac Myosins / metabolism
  • Cell Line
  • Electric Impedance
  • Endothelial Cells / cytology
  • Endothelial Cells / drug effects
  • Endothelial Cells / metabolism*
  • Endothelial Cells / ultrastructure
  • Fluorescein-5-isothiocyanate / metabolism
  • Humans
  • Intracellular Space / drug effects
  • Intracellular Space / metabolism*
  • Kidney Glomerulus / cytology*
  • Kidney Glomerulus / physiology*
  • Kidney Glomerulus / ultrastructure
  • Mutant Proteins / pharmacology
  • Myosin Light Chains / metabolism
  • Paracrine Communication / drug effects*
  • Permeability / drug effects
  • Phosphorylation / drug effects
  • Time Factors
  • Vascular Endothelial Growth Factor A / pharmacology
  • Vascular Endothelial Growth Factor C / pharmacology*
  • Vascular Endothelial Growth Factor Receptor-2 / metabolism
  • Vascular Endothelial Growth Factor Receptor-3 / metabolism
  • Vascular Endothelial Growth Factor Receptor-3 / ultrastructure

Substances

  • Antigens, CD
  • Cadherins
  • Mutant Proteins
  • Myosin Light Chains
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factor C
  • cadherin 5
  • myosin light chain 2
  • Vascular Endothelial Growth Factor Receptor-2
  • Vascular Endothelial Growth Factor Receptor-3
  • Cardiac Myosins
  • Fluorescein-5-isothiocyanate
  • Calcium