EGF and TGF-alpha stimulate retinal neuroepithelial cell proliferation in vitro.

Peptide growth factors have been shown to have diverse effects on cells of the CNS, such as promoting neuronal survival, neurite outgrowth, and several other aspects of neuronal differentiation. In addition, some of these factors have been shown to be mitogenic for particular classes of glial cells within the brain and optic nerve, and recently two peptide growth factors, fibroblast growth factor and nerve growth factor, have been shown to have mitogenic activity on the CNS neuronal progenitors. We now report that two members of another peptide growth factor, epidermal growth factor and transforming growth factor-alpha, are mitogenic for retinal neuroepithelial cells in primary cultures and provide evidence for the presence of both of these factors in normal developing rat retina.