The effect of platelet-derived growth factor on phagocytosis of cultured human trabecular cells.

Platelet-derived growth factor (PDGF) enhanced the phagocytic activity of cultured human trabecular cells in a dose-dependent manner (5-40 ng ml-1). By transmission and scanning electron microscopy, microvilli on the cell surface were shown to make contact with latex particles. Subsequently the cell surface invaginated and engulfed them. By indirect immunofluorescence, actin was found to form stress fibers in PDGF-free cells. PDGF-treated cells were stained in thread-like patterns on the cell surface. In addition to this image, membrane ruffles and actin ribbons were also observed. These findings suggest that PDGF may serve to facilitate phagocytosis and migration of trabecular cells by modifying trabecular cell actin.