Expression of pigment epithelium-derived factor in experimental choroidal neovascularization.
OBJECTIVE
To investigate the expression of pigment epithelium-derived factor (PEDF) in the rat laser-injury model of choroidal neovascularization (CNV).


METHODS
Retinas were immunostained for PEDF at different times (1, 2, and 3 weeks) after laser injury. Levels of PEDF protein in the vitreous at 1, 3, 7, 14, and 28 days after laser injury were also assayed by Western blot.


RESULTS
Protein levels of PEDF in the vitreous were increased during the first 7 days after CNV induction. Immunostaining for PEDF was observed throughout normal nonlasered control retinas, sham-lasered retinas, and areas remote to laser lesions, which were generally more intense in the outer nuclear layer (ONL) and less intense in the internal nuclear layer (INL). Decreased expression of PEDF was observed in flanking areas adjacent to the injury site and was confined mainly to the ONL. In the injury sites, immunostaining within the ONL was either absent or decreased for up to 3 weeks after laser injury (the duration of the study). Preadsorption of the anti-PEDF antibody with the immunizing peptide blocked specific labeling in the retina.


CONCLUSIONS
These results demonstrate an inverse correlation of expression of PEDF and formation of CNV in the experimental model and suggest that decreased expression of PEDF plays a permissive role in the formation of CNV. PEDF analogues may be a reasonable treatment strategy for CNV.
Renno
Reem Z
RZ
Angiogenesis Laboratory, Retina Research Institute, Massachusetts Eye and Ear Infirmary, 245 Charles Street, Boston, MA 02114, USA.
Youssri
Ayman I
AI
Michaud
Norman
N
Gragoudas
Evangelos S
ES
Miller
Joan W
JW
D000818:Animals; D015153:Blotting, Western; D002829:Choroid / Q000098:blood supply / Q000601:surgery; D020256:Choroidal Neovascularization / Q000378:metabolism* / Q000473:pathology; D005136:Eye Proteins / Q000378:metabolism*; D005451:Fluorescein Angiography; D007124:Immunoenzyme Techniques; D053685:Laser Therapy; D008297:Male; D023421:Models, Animal; D009414:Nerve Growth Factors; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D011914:Rats, Inbred BN; D015843:Serpins / Q000378:metabolism*; D014822:Vitreous Body / Q000378:metabolism; D000099174:Pigment Epithelium-Derived Factor
D005136:Eye Proteins; D009414:Nerve Growth Factors; D011506:Proteins; D015843:Serpins; D000099174:Pigment Epithelium-Derived Factor