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 language | English |
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Pages (from-to) | 162-170 |
Number of pages | 9 |
Journal | Current Eye Research |
Volume | 19 |
Publication status | Published - 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