Glucose-mediated regulation of transforming growth factor-beta (TGF-beta) and TGF-beta receptors in human retinal endothelial cells

M M Pascal, J V Forrester, R M Knott

Research output: Contribution to journalArticle

Abstract

Purpose. Diabetic retinopathy is a micro-angiopathy affecting predominantly small vessels of the retina. Clinical trials have demonstrated a strong association between tight glucose control and a reduction in the incidence and the severity of diabetic retinopathy. Transforming growth factor beta (TGF-beta) is involved in the control of endothelial cell proliferation, adhesion, and deposition of extracellular matrix, thus TGF-beta may play a role in the control of endothelial cell proliferation seen in the disease. We wished to investigate the regulation of transforming growth factor beta and its receptors (type I and II) in human retinal endothelial cells exposed to a range of glucose concentrations.

Methods. Human retinal endothelial cells were isolated from donor eyes, cultured in vitro and exposed to a range of glucose concentrations (0-25 mmol/l). TGF-beta protein and mRNA levels were determined by ELISA and Northern analysis, respectively. The binding affinities and TGF-beta receptor numbers were defined using a binding assay.

Results. Northern hybridisation and ELISA showed that after 8 hours, the level of TGF-beta mRNA and protein was significantly higher at 15mmol/l compared to 5, 20 or 25mmol/l 1. Binding assays showed that for high glucose (25 mmol/l), human retinal endothelial cells express a population of TGF-beta receptors with higher affinity for its ligand than at 5 or 15 mmol/l.

Conclusions. These results demonstrate that glucose regulates TGF-beta mRNA and protein production and also TGF-beta receptor expression in human retinal endothelial cells. Thus, the glucose-mediated changes that occur in diabetic patients may expose human retinal endothelial cells to potential angiogenic factors which may influence disease progression.

Original languageEnglish
Pages (from-to)162-170
Number of pages9
JournalCurrent Eye Research
Volume19
Publication statusPublished - 1999

Keywords

  • glucose
  • transforming growth factor-beta (TGF-beta)
  • TGF-beta receptors
  • diabetic retinopathy
  • retinal endothelial cells
  • human
  • DIABETIC-RETINOPATHY
  • GENE-EXPRESSION
  • GROWTH-FACTOR-BETA-1
  • INHIBITION
  • TGF-BETA-1
  • PROLIFERATION
  • ANGIOGENESIS
  • MODULATION
  • PERICYTES
  • COLLAGEN

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