Morphological and immunohistochemical characteristics of the equine corneal epithelium.
Abstract: The morphology of the corneal epithelium in two age groups of horses is described. Distribution patterns of proliferation-, differentiation-, stem cell-associated markers and cell junction proteins were assessed. Methods: Corneal samples from 12 horses (six foals and six adult horses) were analyzed after H&E staining and immunohistochemistry using the following antibodies: E-cadherin, β-catenin, Connexin 43 (Cx43), tight junction protein 1 (TJP1), cytokeratin (CK) 14, CK 19, CK 3, CK 10, vimentin, Ki67, p63, nerve growth factor (NGF), ABCG2, and epithelial growth factor receptor. Semiquantitative analysis of crypt, limbal, peripheral, and central zone was performed. Semithin and ultrathin sections were used for ultrastructural evaluation of the epithelium. Results: The height of the epithelium varied between age groups and crypts were consistently present. In the peripheral and central epithelium, three types of basal cells resembling a pseudostratified epithelium were characterized. Potential stem cell markers (CK 14, p63, NGF, and ABCG2) were present in all zones with decreasing frequency toward the center. Cornea-specific differentiation marker CK 3 was not expressed in the most basal cell layer of the limbal epithelium. E-cadherin, β-catenin, and Cx43 revealed a similar apico-lateral signal pattern throughout the entire epithelium; only TJP1 was additionally seen at the basal surface. Conclusions: This study presents a systematic semiquantitative evaluation of the equine corneal epithelium, showing the presence of crypts as potential stem cell niche with CK 14, p63, NGF, and ABCG2 as relevant markers for cells with regenerative capacity. The pseudostratified arrangement of the basal layer was a unique finding.
© 2019 The Authors. Veterinary Ophthalmology published by Wiley Periodicals, Inc. on behalf of American College of Veterinary Ophthalmologists.
Publication Date: 2019-02-14 PubMed ID: 30767359PubMed Central: PMC6900071DOI: 10.1111/vop.12651Google Scholar: Lookup
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- Journal Article
Summary
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The research features an in-depth study examining the morphology and immunohistochemical properties of the corneal epithelium in horses of varying age groups. The research also explores the potential presence of stem cell markers and their distribution within the corneal epithelium.
Research Methodology
- Corneal samples were taken from 12 horses, split equitably between foals and adult horses.
- These samples were analyzed after Hematoxylin and Eosin (H&E) staining, a popular staining method in histology, and subjected to immunohistochemistry.
- The immunohistochemistry tests involved the use of a variety of antibodies including E-cadherin, β-catenin, Connexin 43 (Cx43), tight junction protein 1 (TJP1), several cytokeratins, vimentin, Ki67, p63, nerve growth factor (NGF), ABCG2, and epithelial growth factor receptor.
- A semiquantitative analysis of different zones of the cornea including the crypt, limbal, peripheral, and central zones was conducted.
- Semithin and ultrathin sections of the cornea samples were used for ultrastructural evaluation of the epithelium.
Key Findings
- There were differences in the height of the epithelium between the two age groups studied. Additionally, all horses’ cornea samples consistently presented crypts.
- The peripheral and central epithelium exhibited three types of basal cells, suggesting a pseudostratified epithelium.
- Stem cell markers including CK 14, p63, NGF, and ABCG2 were found in all zones, with fewer found towards the center of the cornea.
- The differentiation marker CK 3, specific to corneas, was not observed in the basal cell layer of the limbal epithelium. Meanwhile, E-cadherin, β-catenin, and Cx43 showcased a similar pattern of apico-lateral signals across the epithelium, with TJP1 also seen at the basal surface.
Conclusions and Implications
- The findings from this study provide a systematic and semiquantitative evaluation of the corneal epithelium in horses. The discovery of crypts suggests potential niches for stem cells within the corneal epithelium.
- The presence of CK 14, p63, NGF, and ABCG2 markers indicate cells with possible regenerative capacity. The unique pseudostratified arrangement of the basal layer was a noteworthy find.
- The results of this study add substantive data to our understanding of the equine corneal epithelium and may open new paths for future research regarding stem cell therapies and corneal diseases in horses.
Cite This Article
APA
Kammergruber E, Rahn C, Nell B, Gabner S, Egerbacher M.
(2019).
Morphological and immunohistochemical characteristics of the equine corneal epithelium.
Vet Ophthalmol, 22(6), 778-790.
https://doi.org/10.1111/vop.12651 Publication
Researcher Affiliations
- Histology and Embryology, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria.
- Histology and Embryology, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria.
- Department of Companion Animals and Horses, University of Veterinary Medicine, Vienna, Austria.
- Histology and Embryology, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria.
- Histology and Embryology, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria.
MeSH Terms
- Aging
- Animals
- Antibodies / immunology
- Epithelial Cells / physiology
- Epithelium, Corneal / anatomy & histology
- Epithelium, Corneal / chemistry
- Epithelium, Corneal / cytology
- Gene Expression Regulation / physiology
- Horses / anatomy & histology
- Immunohistochemistry / veterinary
- Stem Cells / physiology
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Citations
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