Multipotent retinal progenitors express developmental markers, differentiate into retinal neurons, and preserve light-mediated behavior

Purpose. To use progenitor cells isolated from the neural retina for transplantation studies in mice with retinal degeneration. Methods. Retinal progenitor cells from postnatal day 1 green fluorescent protein-transgenic mice were isolated and characterized. These cells can be expanded greatly in culture and express markers characteristic of neural progenitor cells and/or retinal development. Results. After they were grafted to the degenerating retina of mature mice, a subset of the retinal progenitor cells developed into mature neurons, including presumptive photoreceptors expressing recoverin, rhodopsin, or cone opsin. In rho(-/-) hosts, there was rescue of cells in the outer nuclear layer (ONL), along with widespread integration of donor cells into the inner retina, and recipient mice showed improved light-mediated behavior compared with control animals. Conclusions. These findings have implications for the treatment of retinal degeneration, in which neuronal replacement and photoreceptor rescue are major therapeutic goals.