Positive association of pigment epithelium-derived factor with total antioxidant capacity in the vitreous fluid of patients with proliferative diabetic retinopathy.
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.


OBJECTIVE
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) microg/ml; control, 7.4 (4.1) microg/ml; PDR VH(+) 8.5 (3.6) microg/ml).


CONCLUSIONS
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.
Yokoi
Masahiko
M
Department of Ophthalmology, Hokkaido University Graduate School of Medicine, Sapporo, Japan. zoyokoi.tdr@keijinkai.or.jp
Yamagishi
Sho-ichi
S
Saito
Akari
A
Yoshida
Yumiko
Y
Matsui
Takanori
T
Saito
Wataru
W
Hirose
Shigeki
S
Ohgami
Kazuhiro
K
Kase
Manabu
M
Ohno
Shigeaki
S
D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000032:analysis*; D003930:Diabetic Retinopathy / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005136:Eye Proteins / Q000032:analysis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009414:Nerve Growth Factors / Q000032:analysis*; D010084:Oxidation-Reduction; D015843:Serpins / Q000032:analysis*; D014822:Vitreous Body / Q000737:chemistry*; D000099174:Pigment Epithelium-Derived Factor
D000975:Antioxidants; D005136:Eye Proteins; D009414:Nerve Growth Factors; D015843:Serpins; D000099174:Pigment Epithelium-Derived Factor