Abstract
Purpose: :
Compare the distribution of corneal epithelial progenitor cell markers in the limbal region of wild-type (Pax6+/+) and Small-eye (Pax6+/SeyNeu) mice.
Methods: :
Eyes from 12-13 week old wild-type (WT) and Small-eye (Sey) mice were fixed, embedded and sectioned (paraffin: 4µm, cryosectioning: 10µm). Sections were single- or double-labeled, with antibodies to p63, ABCG2, Pax6, bmi1, vimentin, N-cadherin, connexin 43, or cytokeratin 3+12. Sections were evaluated by microscopy based on staining characteristics and the location of labeled cells.
Results: :
In both WT and Sey mice, cells in the limbal epithelium, beginning at the corneoscleral junction, expressed several progenitor markers, including ABCG2, p63 and Pax6. In WT mice, this group of cells was organized in a limbal aggregation approximately 10 cells long and 2-3 cell layers thick. In Sey mice, cells were comparatively less organized and more broadly distributed. In the WT peripheral corneal epithelium, one layer of basal cells expressed p63 and Pax6. In the Sey mouse, more than one layer expressed p63 and Pax6.
Conclusions: :
Sey eyes show an abnormal labeling pattern for corneal epithelial progenitor cell markers but do not show a lack of these markers. This suggests that Sey mice may have stem cells but they may lack a well circumscribed niche that is found in the limbal region of WT mouse eyes.
Keywords: cornea: epithelium • immunohistochemistry