Effects of chondroitin sulfate on cultured human retinal pigment epithelial cells

We investigated the effects of chondroitin sulfate on growth, morphology and ultrastructure of retinal pigment epithelial (RPE) cells in culture. When added to the medium, chondroitin sulfate reduced cell density in RPE cultures in a dose-dependent manner. Compared with the controls, the treated cells appeared to be larger and more granular. Electron microscopic examinations revealed accumulations of membrane-bound whorls. In addition, phagocytic activity in the treated cells was notably increased and the level of acid lipase was elevated. These data suggest that increased levels of chondroitin sulfate can induce alterations in both metabolism and activities of RPE cells.