Abstract
Abstract: :
Purpose: We have previously reported that triamcinolone acetonide (TA) modulates permeability and intercellular adhesion molecule-1 (ICAM-1) expression of the ECV304 epithelial cell line (1). In the present study, we have used immunocytochemistry and flow cytometry to investigate the effects of TA on the expression of VEGF receptors Flk-1 and Flt-1 in resting and cytokine stimulated human choroidal endothelial cells (HCEC) Methods: HCEC were isolated from post-mortem human eyes, stimulated with INF-gamma, TNF-alpha, phorbol 12-myristate 13-acetate (PMA), and/or treated with TA. The expression of Flk-1 and Flt-1 on HCEC was visualised by immunocytochemistry, and quantified by flow cytometry. Results: HCEC constitutively express Flk-1 and Flt-1 receptors in vitro, TNF-alpha and PMA upregulated both Flk-1 and Flt-1 expression on HCEC whilst INF-gamma produced insignificant effects, determined by both flow cytometry and immunocytochemistry observations. TA treatment produced a significant decrease of PMA-induced Flt-1 expression. Conclusion: HCEC primary isolates represent a useful model for the study of cytokine influences on human vascular cells. Flk-1 and Flt-1 receptors are constitutively expressed on HCEC which may be subject to modulation by proinflammatory cytokines in vitro and in vivo. The suppression of VEGF receptor expression on HCEC by TA indicates that glucocorticoids have the capacity to inhibit vascular permeability and proliferation. References: 1. Penfold PL, Wen L, Madigan MC, Gillies MC, King, NJC & Provis JM. Clin Exp Immunol, 2000 121:458-465.