Pterygial Derived Fibroblasts Express Functionally Active Histamine and Epidermal Growth Factor Receptors

• Published in: Experimental eye research 2002-02, Vol.74 (2), p.237-244
• Main Authors: Maini, Raj, Collison, David J., Maidment, Jill M., Davies, Peter D., Wormstone, I.Michael
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; calcium; Calcium - analysis; Calcium - metabolism; Cell receptors; Cell structures and functions; Cells, Cultured; EGF; Epidermal Growth Factor - pharmacology; ERK; fibroblasts; Fibroblasts - chemistry; Fundamental and applied biological sciences. Psychology; histamine; Histamine - pharmacology; Hormone receptors. Growth factor receptors. Cytokine receptors. Prostaglandin receptors; human; Humans; Immunohistochemistry; internalization; Intracellular Fluid - chemistry; Mitogen-Activated Protein Kinase 1 - analysis; Molecular and cellular biology; pterygia; Pterygium - metabolism; Receptor, Epidermal Growth Factor - analysis; receptors; Receptors, Histamine - analysis
• ISSN: 0014-4835; 1096-0007
• DOI: 10.1006/exer.2001.1116

Pterygia are characterised by a fleshy outgrowth of altered conjuctival tissue over the cornea and are most common in tropical regions. Pterygial fibroblasts are characteristically distinct from normal conjunctival fibroblasts, and therefore the aim of this study was to determine the presence and functional significance of histamine and epidermal growth factor (EGF) receptors in these cells. Pterygial specimens were cultured in vitro and cellular outgrowths were phenotypically characterised as fibroblasts using vimentin and cytokeratin staining. Intracellular calcium mobilization was used to characterise the functional activity of histamine receptors on these cells. Maximal response was obtained with 100μM histamine. However, lower concentrations of histamine also caused mobilization of calcium that were totally abolished by pre-incubation with H1 but not H2 or H3 receptor antagonists. EGF receptor was diffusely expressed over the cell surfaces. EGF stimulated receptor internalization, ERK protein phosphorylation and intracellular calcium mobilization. Therefore, fibroblasts derived from human pterygia express functionally active histamine and epidermal growth factor receptors. Controlled modification of either the receptors or the appropriate ligands could have beneficial effects in pterygia treatment.