Systemic administration of HMG-CoA reductase inhibitor protects the blood-retinal barrier and ameliorates retinal inflammation in type 2 diabetes

Exp Eye Res. 2009 Jun 15;89(1):71-8. doi: 10.1016/j.exer.2009.02.013. Epub 2009 Feb 28.

Abstract

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) are frequently used lipid-lowering drugs in type 2 diabetes. Recent emerging evidence suggests that statins protect cardiovascular function via lipid-independent mechanisms. However, the potential role of statins in diabetic retinopathy in type 2 diabetes is largely unclear. In the present study we have investigated the effect of lovastatin on blood-retinal barrier and inflammatory status in the retina of db/db mice and in cultured retinal cells. Male C57BL/KsJ db/db mice were randomly chosen to receive gastric gavage of lovastatin (10mg/kg/day) or vehicle control for 6 weeks. Retinal vascular permeability, the tight junction and inflammation were determined. The results showed that db/db mice at the age of 19 weeks exhibited significantly increased retinal vascular leakage and decreased tight junction protein level in the retina. Moreover, the expression of pro-inflammatory factors, e.g. ICAM-1 and TNF-alpha, was drastically up-regulated in diabetic retina. Lovastatin treatment normalized all of these changes. In cultured bovine retinal capillary endothelial cells (RCECs) and human ARPE-19 cells, lovastatin attenuated the decrease of tight junction protein (occludin) and adherens junction protein (VE-cadherin) expression-induced by TNF-alpha, a major pro-inflammatory cytokine in diabetic retinopathy. Lovastatin also attenuated TNF-alpha expression in RCEC. Towards the mechanism, we showed that lovastatin ameliorated ICAM-1 expression-induced by hypoxia and TNF-alpha in both RCECs and ARPE-19 cells, in part through inhibition of NF-kappaB activation. Taken together, these findings indicate that lovastatin protects blood-retinal barrier in diabetic retinopathy, which is likely via its anti-inflammatory effects.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood-Retinal Barrier / drug effects*
  • Cells, Cultured
  • Diabetes Mellitus, Experimental / metabolism
  • Diabetes Mellitus, Experimental / physiopathology
  • Diabetes Mellitus, Type 2 / metabolism
  • Diabetes Mellitus, Type 2 / physiopathology*
  • Diabetic Retinopathy / metabolism
  • Diabetic Retinopathy / physiopathology
  • Diabetic Retinopathy / prevention & control*
  • Drug Evaluation, Preclinical / methods
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors / pharmacology*
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors / therapeutic use
  • Inflammation Mediators / metabolism
  • Intercellular Adhesion Molecule-1 / metabolism
  • Lipids / blood
  • Lovastatin / pharmacology*
  • Lovastatin / therapeutic use
  • Male
  • Mice
  • Mice, Inbred C57BL
  • NF-kappa B / metabolism
  • Retina / metabolism
  • Retinal Pigment Epithelium / drug effects
  • Tight Junctions / drug effects
  • Tumor Necrosis Factor-alpha / antagonists & inhibitors
  • Tumor Necrosis Factor-alpha / metabolism
  • Tumor Necrosis Factor-alpha / pharmacology

Substances

  • Hydroxymethylglutaryl-CoA Reductase Inhibitors
  • Inflammation Mediators
  • Lipids
  • NF-kappa B
  • Tumor Necrosis Factor-alpha
  • Intercellular Adhesion Molecule-1
  • Lovastatin