Positive association of pigment epithelium-derived factor with total antioxidant capacity in the vitreous fluid of patients with proliferative diabetic retinopathy
- Masahiko Yokoi2,
- Sho-ichi Yamagishi3,
- Akari Saito1,
- Yumiko Yoshida3,
- Takanori Matsui3,
- Wataru Saito1,
- Shigeki Hirose1,
- Kazuhiro Ohgami1,
- Manabu Kase1,2,
- Shigeaki Ohno1
- 1Department of Ophthalmology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
- 2Department of Ophthalmology, Teine-Keijinkai Hospital, Sapporo, Japan
- 3Division of Cardiovascular Medicine, Department of Medicine, Kurume University School of Medicine, Kurume, Japan
- Correspondence to: Dr M Yokoi Department of Ophthalmology, Teine-Keijinkai Hospital, Sapporo 006-8555, Japan;
- Accepted 1 January 2007
- Published Online First 14 February 2007
Background: Pigment epithelium-derived factor (PEDF), a glycoprotein with potent neuronal differentiating activity, was recently found to inhibit advanced glycation end product (AGE)-induced retinal hyperpermeability and angiogenesis through its antioxidative properties, suggesting that it may exert beneficial effects on diabetic retinopathy by acting as an endogenous antioxidant. However, the inter-relationship between PEDF and total antioxidant capacity in the eye remains to be elucidated.
Aims: To determine vitreous PEDF and total antioxidant levels in patients with proliferative diabetic retinopathy (PDR), and to investigate the relationship between them.
Methods: Vitreous levels of PEDF and total antioxidant capacity were measured by an ELISA in 39 eyes of 36 patients with diabetes and PDR and in 29 eyes of 29 controls without diabetes.
Results: Vitreous levels of total antioxidant capacity were significantly lower in patients with diabetes and PDR than in controls (mean (SD) 0.16 (0.05) vs 0.24 (0.09) mmol/l, respectively, p<0.001). PEDF levels correlated positively with total antioxidant status in the vitreous of patients with PDR (r = 0.37, p<0.05) and in controls (r = 0.41, p<0.05). Further, vitreous levels of PEDF in patients with PDR without vitreous haemorrhage (VH(−)) were significantly (p<0.05) decreased, compared with those in the controls or in patients with PDR with vitreous haemorrhage (VH(+); PDR VH(−), 4.5 (1.1) μg/ml; control, 7.4 (4.1) μg/ml; PDR VH(+) 8.5 (3.6) μg/ml).
Conclusion: This study demonstrates that PEDF levels are associated with total antioxidant capacity of vitreous fluid in humans, and suggests that PEDF may act as an endogenous antioxidant in the eye and could play a protective role against PDR.
- AGE, advanced glycation end product
- PEDF, pigment epithelium-derived factor
- PDR, proliferative diabetic retinopathy
- VEGF, vascular endothelial growth factor
Competing interests: None declared.
Published Online First 14 February 2007