Expression of fibroblast activation proteins in corneal stromal neovascularization.
OBJECTIVE
To observe changes of the factors in corneal stroma during corneal neovascularization and to investigate the mechanism of corneal neovascularization.


METHODS
Forty-eight Wistar rats were used, including eight in the control group. Corneal neovascularization was induced by alkali burns in 40 rats. Frozen sections, which were cut across the corneal center, were prepared on days 1, 3, and 7 post-burn, respectively. Transforming growth factor-beta 1 (TGF-beta 1) was examined by immunohistochemistry, and fibroblast activation protein (FAP) and a-smooth muscle actin (a-SMA) were detected by double-labeling fluorescent immunohistochemistry. Blood vessel endothelium was identified for PECAM-1 (CD31). Expressions of FAP in the cornea with or without neovascularization were monitored with reverse transcription-polymerase chain reaction on days 3 and 7.


RESULTS
In the alkali-burned eyes, TGF-ss1 first expressed in the corneal stroma, and some stromal cells expressed a-SMA and FAP. The FAP(+) keratocytes were found around the CD31(+) endothelium of angiogenesis. FAP was expressed in the corneas with neovascularization, but not in those without neovascularization.


CONCLUSIONS
Factors in corneal stroma may change when corneal neovascularization occurs. The stromal keratocytes can express FAP(+) cells surrounding the endothelium of angiogenesis.
Wang
Ting
T
Qingdao University Medical College, Qingdao, China.
Shi
Weiyun
W
D000199:Actins / Q000378:metabolism*; D000818:Animals; D016510:Corneal Neovascularization / Q000378:metabolism* / Q000473:pathology; D003319:Corneal Stroma / Q000098:blood supply*; D004195:Disease Models, Animal; D010450:Endopeptidases; D004730:Endothelium, Vascular / Q000378:metabolism / Q000473:pathology; D005347:Fibroblasts / Q000378:metabolism*; D019084:Fluorescent Antibody Technique, Indirect; D018093:Gelatinases / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D053773:Transforming Growth Factor beta1 / Q000378:metabolism; D000099167:Fibroblast Activation Protein Alpha
D000199:Actins; D010450:Endopeptidases; D018093:Gelatinases; D008565:Membrane Proteins; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D012697:Serine Endopeptidases; D053773:Transforming Growth Factor beta1; D000099167:Fibroblast Activation Protein Alpha; C498862:Acta2 protein, rat