EFFECT OF CYTOKINES AND PROSTAGLANDINS ON THE GROWTH OF CHICK RETINAL-PIGMENT EPITHELIAL-CELLS

The effect of cytokines and prostaglandins on the growth of chick retinal pigment epithelial (RPE) cells was studied in vitro. The growth of RPE cells was evaluated by [H-3]-thymidine uptake. Human recombinant interleukin-1 beta, interferon-beta and tumor necrosis factor-alpha stimulated the growth of RPE cells at 50-200 units/ml. Prostaglandins such as PGE(1), PGE(2) and PGF(2 alpha) suppressed RPE cell. growth at 10(-5 similar to -6) M. Indomethacin, an inhibitor of cyclooxygenase, did not affect the spontaneous RPE cell growth at 10(-7 similar to -9) M. However, 10(-7) M indomethacin enhanced RPE cell growth stimulated by cytokines synergistically. The addition of 10(-6) M PGF(2 alpha) suppressed the enhanced growth of RPE cells which was induced with cytokines and indomethacin. Furthermore, RPE cells stimulated with cytokines produced PGE(2). These results suggest that RPE cells produce prostaglandins which have a negative regulatory role in RPE cell growth.