Abstract
Abstract: :
Purpose:Pigment epithelium–derived factor (PEDF) is a protein shown to have a neuroprotective activity. PEDF is also called EPC–1, reflecting its up–regulation during cell cycle arrest (G0) in young but not in senescent cells in vitro. The aim of this study was to determine the levels of PEDF in eyes with neuroretinal dystrophic diseases and also to determine whether the level of PEDF is altered with age. Methods: A total of 168 eyes of 132 individuals who underwent cataract surgery was studied. The primary diagnosis was cataract alone in the controls (148 eyes of 118 patients, age ranged 50 to 88 years, 71.7 ± 0.8 years, mean ± SE). In the experimental group, there were 5 eyes of 3 patients with retinitis pigmentosa (67.8 ± 7.4 years), 9 eyes of 7 patients with advanced glaucoma (68.5 ± 3.6 years), and 6 eyes of 4 patients with chorioretinal atrophy associated with high myopia (69.7 ± 2.6 years). Aqueous humor was obtained during cataract surgery, and the PEDF concentration was measured by enzyme–linked immunosorbent assay (ELISA). Results: The mean level of PEDF was 0.86 ± 0.04 µg/ml (mean ± SE) in eyes with cataract alone and without any other eye diseases. The PEDF levels decreased significantly with increasing age (Pearson's product moment correlation coefficient, r = – 0.26, P =0.006). The mean PEDF level in the men (0.76 ± 0.06 µg/ml, 53 eyes, 71.5±2.0 years) was significantly lower than that in women (0.91±0.04 µg/ml, 99 eyes, 70.2±1.1 years, P =0.03). The PEDF levels in eyes with retinitis pigmentosa (0.24 ± 0.04 µg/ml, P = 0.0004), advanced glaucoma (0.46 ± 0.08 µg/ml, P = 0.003), and chorioretinal atrophy with high myopia (0.53 ± 0.02 µg/ml, P = 0.038) were significantly lower than that in eyes with cataract alone. Conclusions: The negative correlation of PEDF level and age should be considered in age–related eye diseases especially those associated with angiogenesis. The lower levels of PEDF in eyes with neuroretinal dystrophy may be related to the loss of the retinal ganglion cells and/or RPE cells that synthesize PEDF.
Keywords: growth factors/growth factor receptors • neuroprotection • retinal pigment epithelium