Glycosaminoglycan synthesis by cultured human retinal pigmented epithelium from normal postmortem donors and a postmortem donor with retinitis pigmentosa.

Cultured human retinal pigmented epithelium (RPE) synthesized and secreted glycosaminoglycans (GAGs) with the characteristics of chondroitin sulfate, dermatan sulfate, and hyaluronic acid from radioactive precursors. Cells subcultured for up to 18 passages from normal RPE and from the RPE of a patient with X-linked retinitis pigmentosa synthesized and secreted the same types and proportions of GAGs as primary cultures of normal RPE. Extracts of native human interphotoreceptor matrix contained hyaluronic acid and chondroitin sulfate but little or no dermatan sulfate, and the chondroitin sulfate differed in electrophoretic mobility and enzyme susceptibility from the chondroitin sulfates secreted by cultured RPE. Cultured human choroidal cells and cultured human skin fibroblasts secreted a much higher proportion of hyaluronic acid than cultured RPE. This study demonstrates that the profile of GAGs synthesized from radioactive precursors and secreted by cultured human RPE is a specific and stable characteristic of these cells that is retained even after extensive proliferation in vitro.