Epidermal growth factor, transforming growth factor alpha, transforming growth factor beta, acidic fibroblast growth factor, basic fibroblast growth factor, and interleukin-1 proteins in the cornea

Abstract

The purpose of this study was to determine whether epidermal growth factor (EGF), EGF receptor, transforming growth factor alpha (TGF-alpha), transforming growth factor beta (TGF-beta), acidic fibroblast growth factor (acidic-FGF), basic fibroblast growth factor (basic-FGF), and interleukin-1-alpha (IL-1-alpha) proteins were present in cultures of human corneal cells and/or in sections of human corneal tissue. Immunohistochemistry was performed on human corneal sections. Immunofluorescent cell staining was used to evaluate corneal epithelial, stromal fibroblast, and endothelial cells in primary culture. Basic-FGF production was evaluated in culture cells using immunoprecipitation. EGF, TGF-alpha, TGF-beta-1, and IL-1-alpha were detected by immunohistochemistry in cells in all three layers of the cornea. EGF receptor and acidic FGF were detected by immunohistochemistry in epithelial and endothelial cells, but not in stromal fibroblast cells. Differences in distribution of the growth factors were noted within individual layers of the cornea. EGF and basic-FGF proteins were detected in all three predominant cell types of the cornea using immunocytology. IL-1-alpha protein was detected by immunocytology in corneal epithelial and endothelial cells, but not stromal fibroblasts. Immunoprecipitation confirmed the production of basic-FGF in all three cell types. IL-1-alpha protein detection in the corneal stroma by immunohistology, but not by immunocytology in first passage stromal fibroblasts, suggests that IL-1-alpha may localize to the corneal stroma after production by corneal epithelial and/or endothelial cells.