Ahmed M Abu El-Asrar1, Luc Missotten, Karel Geboes. 1. Department of Ophthalmology, King Abdulaziz University Hospital, Airport Road, PO Box 245, Riyadh 11411, Saudi Arabia. abuasrar@ksu.edu.sa
Abstract
AIMS: To investigate the expression of the hypoxia-inducible factor-1alpha (HIF-1alpha) and the protein products of its target genes vascular endothelial growth factor (VEGF), erythropoietin (Epo) and angiopoietins (Angs), and the antiangiogenic pigment epithelium-derived factor (PEDF) in proliferative diabetic retinopathy (PDR) epiretinal membranes. METHODS: Sixteen membranes were studied by immunohistochemical techniques. RESULTS: Vascular endothelial cells expressed HIF-1alpha, Ang-2 and VEGF in 15 (93.75%), 6 (37.5%) and 9 (56.25%) membranes, respectively. There was no immunoreactivity for Epo, Ang-1 and PEDF. There were significant correlations between the number of blood vessels expressing the panendothelial marker CD34 and the numbers of blood vessels expressing HIF-1alpha (r = 0.554; p = 0.026), Ang-2 (r = 0.830; p<0.001) and VEGF (r = 0.743; p = 0.001). The numbers of blood vessels expressing Ang-2 and VEGF in active membranes were higher than that in inactive membranes (p = 0.015 and 0.028, respectively). CONCLUSIONS: HIF-1alpha, Ang-2 and VEGF may play an important role in the pathogenesis of PDR. The findings suggest an adverse angiogenic milieu in PDR epiretinal membranes favouring aberrant neovascularisation and endothelial abnormalities.
AIMS: To investigate the expression of the hypoxia-inducible factor-1alpha (HIF-1alpha) and the protein products of its target genes vascular endothelial growth factor (VEGF), erythropoietin (Epo) and angiopoietins (Angs), and the antiangiogenic pigment epithelium-derived factor (PEDF) in proliferative diabetic retinopathy (PDR) epiretinal membranes. METHODS: Sixteen membranes were studied by immunohistochemical techniques. RESULTS: Vascular endothelial cells expressed HIF-1alpha, Ang-2 and VEGF in 15 (93.75%), 6 (37.5%) and 9 (56.25%) membranes, respectively. There was no immunoreactivity for Epo, Ang-1 and PEDF. There were significant correlations between the number of blood vessels expressing the panendothelial marker CD34 and the numbers of blood vessels expressing HIF-1alpha (r = 0.554; p = 0.026), Ang-2 (r = 0.830; p<0.001) and VEGF (r = 0.743; p = 0.001). The numbers of blood vessels expressing Ang-2 and VEGF in active membranes were higher than that in inactive membranes (p = 0.015 and 0.028, respectively). CONCLUSIONS:HIF-1alpha, Ang-2 and VEGF may play an important role in the pathogenesis of PDR. The findings suggest an adverse angiogenic milieu in PDR epiretinal membranes favouring aberrant neovascularisation and endothelial abnormalities.
Authors: Ahmed M Abu El-Asrar; Mohd Imtiaz Nawaz; Dustan Kangave; Mohammed Mairaj Siddiquei; Karel Geboes Journal: J Diabetes Res Date: 2013-03-10 Impact factor: 4.011