Evaluation of ABCG2 and p63 expression in canine cornea and cultivated corneal epithelial cells.
OBJECTIVE
To examine the expressions of ABCG2 and p63 in canine corneal epithelia and to evaluate their significance in corneal regeneration.


METHODS
Canine corneal and limbal epithelial cells were obtained from five healthy beagle dogs. We analyzed the morphological properties of cultivated limbal and corneal epithelial cells. We compared the expressions of ABCG2 and p63 in the limbus and central cornea by immunohistochemistry and real-time quantitative PCR. We analyzed the expression of these markers in cultivated cells by immunocytochemistry and real-time quantitative PCR.


RESULTS
The limbal epithelial cells were smaller and proliferated more rapidly than the corneal epithelial cells in primary cultures. The corneal cells failed to be subcultured, whereas the limbal cells could be subcultured with increasing cell size. ABCG2 was localized in the basal layer of the limbal epithelium, and p63 was widely detected in the entire corneal epithelia. ABCG2 expression was significantly higher, and p63 was slightly higher in the limbus compared with the central cornea. ABCG2 was detected only in limbal cells in primary culture, not in corneal cells or passaged limbal cells. p63 was detected in both limbal and corneal cells and decreased gradually in the limbal cells with the cell passages.


CONCLUSIONS
ABCG2 was localized in canine limbal epithelial cells, and p63 was widely expressed in canine corneal epithelia. ABCG2 and p63 could prove to be useful markers in dogs for putative corneal epithelial stem cells and for corneal epithelial cell proliferation, respectively.
Laboratory of Veterinary Surgery, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
Maresuke
M
Morita
Naoki
N
Fujita
Ayaka
A
Takahashi
Eun Ryel
ER
Nam
Sho
S
Yui
Cheng Shu
CS
Chung
Naoya
N
Kawahara
Hsing Yi
HY
Lin
Keiko
K
Tsuzuki
Takayuki
T
Nakagawa
Ryohei
R
Nishimura
D018528:ATP-Binding Cassette Transporters / Q000032:analysis* / Q000096:biosynthesis; D000818:Animals; D002478:Cells, Cultured; D003315:Cornea / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D004285:Dogs; D019573:Epithelium, Corneal / Q000737:chemistry* / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D016850:Limbus Corneae / Q000737:chemistry / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D018613:Microscopy, Confocal / Q000662:veterinary; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D025521:Tumor Suppressor Proteins / Q000032:analysis* / Q000096:biosynthesis
D018528:ATP-Binding Cassette Transporters; D025521:Tumor Suppressor Proteins
ABCG2; canine corneal epithelium; corneal epithelial stem cells; dog; limbus; p63