A retinal pigment epithelial cell-derived growth factor(s)
J. A. Bryan 3rd and P. A. Campochiaro
Proliferation of retinal pigment epithelial (RPE) cells, fibroblasts, and
glial cells has been implicated in the pathogenesis of proliferative
vitreoretinopathy. In this study, we demonstrate that RPE cells in culture
produce a factor(s) that stimulates the growth of each of these cell types.
After 48 hours of incubation with RPE-conditioned media, cell number is
increased over that of controls by 110% for RPE cells, 105% for astrocytes,
and 360% for corneal fibroblasts. Thymidine incorporation demonstrates that
this increase is due to a stimulation of DNA synthesis. Preliminary
characterization of the RPE growth-promoting activity demonstrates that it
is heat stable, stable to extremes of pH, nondialyzable, and partially
trypsin sensitive. These data suggest that RPE cells in culture produce a
growth factor(s) targeted primarily at fibroblasts, but that can also
stimulate their own growth and that of astrocytes.
