Pigment epithelium-derived factor in cataractous aqueous humor and lens epithelial cells.
OBJECTIVE
To study the characteristics of PEDF in cataractous aqueous humor and its expression in human lens epithelium.


METHODS
The PEDF concentration in the aqueous humor was measured by enzyme-linked immunosorbent assay in senile (130 cases) and congenital (18 cases) cataract patients who underwent cataract phacoemulsification extraction surgery. Anterior lens capsular specimens were obtained from these patients to count lens epithelial cells (LEC) density. The Lens Opacities Classification System III was used to classify the senile cataracts as cortical, nuclear, posterior subcapsular and mixed types of opacity, and quantitative analysis of the nuclear opacities was performed by Pentacam Scheimpflug imaging system. Anterior lens capsular specimens from another senile (10 cases) and congenital (10 cases) cataract were collected for immunofluorescence with polyclonal antibodies specific to human pigment epithelium-derived factor (PEDF).


RESULTS
The mean aqueous level of PEDF was (178.9 +/- 87.5) ng/ml, and there was negative linear correlation of PEDF level and age (r = 0.811, P < 0.001) . In senile cases, the aqueous PEDF concentration decreased with increasing nuclear opacities (r = 0.447, P < 0.01), and the mean PEDF level in nuclear cataract was significantly lower than that in posterior subcapsular opacity (P < 0.01). PEDF immunostaining was detected in LEC of all capsular specimens.


CONCLUSIONS
The PEDF level in human aqueous humor is related to age, types of cataracts and lens opacity. PEDF also express in human LEC. The study results suggest PEDF may regulate and/or protect LEC by paracrine and autocrine, and lack of PEDF may play a role in cataractogenesis.
Liu
Tian
T
Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, PR China. fifaspring@yahoo.com.cn
Liu
Yizhi
Y
Wu
Mingxing
M
D000368:Aged; D000369:Aged, 80 and over; D001082:Aqueous Humor / Q000378:metabolism*; D002386:Cataract / Q000378:metabolism* / Q000473:pathology; D004847:Epithelial Cells / Q000378:metabolism*; D005136:Eye Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D007908:Lens, Crystalline / Q000166:cytology*; D008297:Male; D008875:Middle Aged; D009414:Nerve Growth Factors / Q000378:metabolism*; D018918:Phacoemulsification; D015843:Serpins / Q000378:metabolism*; D000099174:Pigment Epithelium-Derived Factor
D005136:Eye Proteins; D009414:Nerve Growth Factors; D015843:Serpins; D000099174:Pigment Epithelium-Derived Factor