Purchase this article with an account.
B Zhao, J Cai, ME Boulton; Regulation of Placenta Growth Factor Expression in Retinal Cells . Invest. Ophthalmol. Vis. Sci. 2002;43(13):1288.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose:We have previously reported the expression of placenta growth factor in proliferative diabetic retinopathy (PDR). The aim of this study was to identify factors which regulate the expression of PlGF by retinal cells in vitro. Methods:Confluent culture of bovine retinal microvascular endothelial cells, bovine pericytes and human RPE cells were exposed to 10ng/ml VEGF, 100ng/ml VEGF, 5mM glucose, 15mM glucose and 25mM glucose and incubated for 24 hours at 37oC. Total RNA was isolated, reverse transcription and polymerse chain reaction (RT-PCR) were performed. For detection of PlGF protein, the confluent cells were incubated under the above conditions for 24 hours in serum-free culture media. The media were collected and western blotting for PlGF was performed following immunoprecipition. Results:Endothelial cells consistently expressed PlGF at both the gene and protein level in culture medium without additions. 100ng/ml VEGF and 15mM glucose both up-regulated expression. Pericytes expression of PlGF was very low level and did not appear to be affected by either VEGF or glucose. There was no expression of PlGF mRNA or protein in human RPE under the experimental conditions employed. To elucidate the mechanism for glucose and VEGF up-regulation of PlGF expression in endothelial cells, VEGFR-1 and VEGFR-2 were blocked using neutralizing antibodies immediately prior to addition of 100ng/ml and 15mM glucose. VEGF and glucose stimulation was diminished after blocking the VEGFR-2 but not VEGFR-1. Conclusion:Changes in VEGF and glucose levels during the progression of PDR may explain the up-regulation of PlGF during active pre-retinal neovascularization. The affect appears to be regulated via VEGFR-2.
This PDF is available to Subscribers Only