Wnt3a Promotes the Proliferation of Endogeneous Progenitor–Like Cells in the Adult Mammalian Retina

Abstract

Abstract: : Purpose: Previously we reported that some Muller glial cells of adult mammalian retina were stimulated to proliferate in response to a toxic injury and produce retinal neuronal cells. However these newly produced neurons were limited in number. The purpose of this study is to determine whether Wnt3a, which has been reported to regulate neuronal stem cells, influence the proliferation and differentiation of Muller glia after retinal damage. Methods: The retinal explants were isolated from adult DA rat eyes. Wnt3a and BrdU were added in the medium every day. After 4 days of culture, the explants were subjected to immunohistochemistry with anti–BrdU and retinal cell markers. Results: The number of BrdU–positive cells in the INL increased significantly in the presence of Wnt3a. Many of them expressed Glutamine–Synthetase, suggesting that Wnt3a promoted the proliferation of Muller glial cells. When the medium was replaced with the one without Wnt3a for further 7 days, some BrdU–positive cells expressed Rhodopsin. Conclusions:Wnt3a, a putative stem cell stimulation factor in the retina, promoted the proliferation of Müller glial cells. Wnt3a may expand the possibility of retinal regeneration.

Keywords: retina • regeneration • Muller cells