Abstract
Purpose: :
Neurotrophic keratopathy (NK) remains difficult to treat. It can cause corneal epithelial defects, stromal thinning and perforation suggesting a role of corneal nerves in maintaining the corneal homeostasis. The purpose of this study was to investigate the effect of corneal denervation on corneolimbal progenitor cells.
Methods: :
NK was induced in mice by electro-coagulation of the trigeminal nerve and absence of corneal nerves was assessed by beta-III tubulin immunostaining. Real-time polymerase chain reaction was performed to quantify expression of corneal progenitor cell markers. ATP-binding cassette subfamily G member 2 (ABCG2), p63, hairy enhancer of split 1 (Hes1), Keratin 15 was assessed in denervated mice and controls by immunofluorescence microscopic studies. In addition, colony-forming efficiency (CFE) assay was performed to assess corneal progenitor cell function.
Results: :
ABCG2, p63, Hes1 expression detected with immunostaining was decreased in denervated corneas after 7days compared to those in the normal corneas. Similarly, mRNA expression levels for ABCG2, p63, Hes1, N-cadherin and Keratin 15 were significantly decreased in denervated corneas. In addition, we found a significant reduction (~50%) in CFE of progenitor cells harvested from denervated eyes compared to normal eyes.
Conclusions: :
Our results suggest that corneal progenitor cells are significantly reduced in number and function in our animal model of corneal denervation. Our data provide novel evidence for the critical role of innervation in maintaining corneal epithelial cells and/or the stem cell niche.
Keywords: cornea: epithelium • innervation: sensation • proliferation