Experimental Transplantation of Corneal Epithelium-like Cells Induced by Pax6 Gene Transfection of Mouse Embryonic Stem Cells

Department of Ophthalmology, St Marianna University School of Medicine, Kawasaki, Kanagawa, Japan.
Cornea (Impact Factor: 2.04). 01/2008; 26(10):1220-7. DOI: 10.1097/ICO.0b013e31814fa814
Source: PubMed


Corneal epithelial stem cells are deficient in cases of limbal disorders, leading to conjunctival epithelial ingrowth, vascularization, and eventually visual disturbance. We introduced the eye development-associated transcription factor pax6 to embryonic stem (ES) cells and tested whether pax6-transfected cells resembling purified corneal epithelial cells were applicable as a cell source for corneal transplantation.
pax6 cDNA with green fluorescence protein was electrotransfected to ES cells and the cells were cultured with G418 for 14 days. They were characterized by reverse transcription-polymerase chain reaction and immunohistochemistry. The cells were transplanted onto experimentally damaged mouse corneas. Histologic reconstitution of the corneal epithelium was assessed.
pax6-transfected cells formed a monolayer of epithelium-like cells in vitro. They expressed cytokeratin12, a specific keratin of corneal epithelial cells, E-cadherin, and CD44, which are important adhesion molecules of corneal epithelial cells on the cell membrane. They accumulated to make a colony that gave a staining pattern of reticular configuration for cytokeratin 12, E-cadherin, and CD44. When the cells were transplanted onto damaged cornea, they have been kept alive on the cornea.
The purified corneal epithelium-like cells derived from ES cells transfected with pax6 gene adapted to the injured cornea and were kept alive on it. These results suggested application of ES cell-derived corneal epithelial cells for treating corneal injuries.

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    • "We have shown that k12 expression is accompanied by upregulation of pax6 expression during transdifferentiation. Overexpression of pax6 in bulge cells switched on k12 expression. A similar result is that pax6- transfected embryonic stem cells expressed k12 and differentiated into corneal epithelial-like cells (Ueno et al., 2007), suggesting that pax6 is necessary for k12 promoter n. Wnt signaling pathway is essential not only for embryogenesis , but also for stem cell differentiation in a range of epithelia. "
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