Abstract
Purpose: :
Ephrin ligands and their Eph receptors, the largest known subfamily of tyrosine kinases, are key regulators of vascular development and of the neuronal system. Furthermore, these molecules are involved in tumor growth, cell adhesion and cell trafficking. Recently, we have shown that ephrin ligands A1-A5 are constitutionally expressed in normal corneas particularly on epithelial cells and that their expression was increased on vascular endothelial cells of new vessels in the stroma and on fibroblasts in scar tissue.1 The aim of the present study was to investigate and to compare the expression of Eph receptors A1-A8 and B1-B6 in normal, vascularized and inflamed human corneas with scar tissue.
Methods: :
30 inflamed and vascularized corneal buttons and 7 non inflamed corneas were obtained during penetrating keratoplasty in patients with various corneal diseases. Immunohistochemistry was performed using the streptavidin-biotin-peroxidase method and highly specific antibodies against Eph receptors A1-A8 and B1-B6.
Results: :
In the present study we could show that Eph receptors like their ephrin ligands are strongly expressed on epithelial cells in normal corneas. In inflamed and vascularized human corneas Eph receptor expression was also found on vascular endothelial cells and on keratocytes/fibroblasts in scar tissue.
Conclusions: :
Althouhg the role of Eph receptors and their ligands in the corneal epithelium remains to be determined the expression of these receptors on vascular endothelial cells of newly formed vessels in the stroma strongly suggests that these molecules may be involved both in VEGF (Eph receptors A) and basic fibroblast growth factor ( Eph receptors B) mediated angiogenesis.1 Philipp WE, Speicher LE. Expression of ephrins in normal and inflamed human corneas. ARVO abstracts:1700;2007
Keywords: cornea: basic science • neovascularization • immunohistochemistry