Simvastatin reduces venous stenosis formation in a murine hemodialysis vascular access model

Kidney Int. 2013 Aug;84(2):338-52. doi: 10.1038/ki.2013.112. Epub 2013 May 1.

Abstract

Venous neointimal hyperplasia (VNH) is responsible for hemodialysis vascular access malfunction. Here we tested whether VNH formation occurs, in part, due to vascular endothelial growth factor-A (VEGF-A) and matrix metalloproteinase (MMP)-9 gene expression causing adventitial fibroblast transdifferentiation to myofibroblasts (α-SMA-positive cells). These cells have increased proliferative and migratory capacity leading to VNH formation. Simvastatin was used to decrease VEGF-A and MMP-9 gene expression in our murine arteriovenous fistula model created by connecting the right carotid artery to the ipsilateral jugular vein. Compared to fistulae of vehicle-treated mice, the fistulae of simvastatin-treated mice had the expected decrease in VEGF-A and MMP-9 but also showed a significant reduction in MMP-2 expression with a significant decrease in VNH and a significant increase in the mean lumen vessel area. There was an increase in terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining, and decreases in α-SMA density, cell proliferation, and HIF-1α and hypoxyprobe staining. This latter result prompted us to determine the effect of simvastatin on fibroblasts subjected to hypoxia in vitro. Simvastatin-treated fibroblasts had a significant decrease in myofibroblast production along with decreased cellular proliferation, migration, and MMP-9 activity but increased caspase 3 activity suggesting increased apoptosis. Thus, simvastatin results in a significant reduction in VNH, with increase in mean lumen vessel area by decreasing VEGF-A/MMP-9 pathway activity.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Actins / metabolism
  • Animals
  • Apoptosis / drug effects
  • Arteriovenous Shunt, Surgical / adverse effects*
  • Carotid Arteries / surgery
  • Caspase 3 / metabolism
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Cell Transdifferentiation / drug effects
  • Constriction, Pathologic
  • Disease Models, Animal
  • Graft Occlusion, Vascular / etiology
  • Graft Occlusion, Vascular / genetics
  • Graft Occlusion, Vascular / metabolism
  • Graft Occlusion, Vascular / pathology
  • Graft Occlusion, Vascular / prevention & control*
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors / pharmacology*
  • Hyperplasia
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism
  • Jugular Veins / drug effects*
  • Jugular Veins / metabolism
  • Jugular Veins / pathology
  • Jugular Veins / surgery
  • Male
  • Matrix Metalloproteinase 2 / metabolism
  • Matrix Metalloproteinase 9 / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Myofibroblasts / drug effects
  • Myofibroblasts / metabolism
  • NIH 3T3 Cells
  • Neointima
  • Renal Dialysis*
  • Signal Transduction / drug effects
  • Simvastatin / pharmacology*
  • Time Factors
  • Vascular Endothelial Growth Factor A / metabolism

Substances

  • Actins
  • Hif1a protein, mouse
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Vascular Endothelial Growth Factor A
  • alpha-smooth muscle actin, mouse
  • vascular endothelial growth factor A, mouse
  • Simvastatin
  • Casp3 protein, mouse
  • Caspase 3
  • Matrix Metalloproteinase 2
  • Mmp2 protein, mouse
  • Matrix Metalloproteinase 9
  • Mmp9 protein, mouse