Purchase this article with an account.
J. Gong, M. A. Fields, J. Tosi, J. Kong, S. H. Tsang, H. Cai, L. V. Del Priore; Subretinal Murine Stem Cell Transplantation in the PDE6beta-Related Mouse Model of Retinitis Pigmentosa. Invest. Ophthalmol. Vis. Sci. 2010;51(13):5256.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Stem cell transplantation is a promising therapeutic approach for the replacement of degenerated retina in patients with age-related macular degeneration (AMD), retinitis pigmentosa (RP) and other disorders. We have shown previously in vitro that a combination of growth factors and Wnt pathway inhibitors can induce both mouse embryonic and mouse neural stem cell to differentiate along RPE or retinal progenitor lines. Here we studied the role of the Wnt signaling pathway after neural stem cells were transplanted into the PDE6beta-related mouse model of RP.
Neuroectodermal stem cells (NE-4C, one-cell derived) expressing a reporter gene for green fluorescent protein (GFP) (ATCC) were also demonstrated to express the transcription factor PAX6 and neural progenitor marker β-tubulin III in retinoid acid treated medium. These cells were injected into the sub retinal space of postnatal day 5 Pde6b (H620Q) homozygous mouse RP model. Electroretinograms (ERGs) from both eyes were monitored to examine the rescue function of the injected cells at 2 months, when the ERG typically shows diminished rod responses in the untreated control eyes. Whole mount retina and histology study was done to examine the injected stem cells at different time points, and the Wnt signaling pathway was studied in mouse retina during rod photoreceptor degeneration.
After 2 weeks of transplantation, whole mount retina and cross sections of retina showed the presence of injected cells between the retinal pigment epithelium (RPE) and photoreceptor layers; some of the transplanted cells demonstrated a neuronal phenotype. Wnt signaling was activated in the retina of the injected eye. Wnt signaling antibodies was localized to the RPE in the uninjected eye; in the injected eye Wnt was also expressed in the photoreceptor layer. Glial fibrillary acidic protein (GFAP) immune-positive Muller cells were also observed in the injected eyes. There was no significant effect of the transplant on the ERG after retinal transplantation.
Transplanted cells demonstrating a neuronal phenotype were visible 2 weeks after transplantation in this murine model of retinal degeneration, but there was no significant change in the ERG after subretinal stem cell transplants. Transplantation does induce expression of Wnt signaling proteins in the photoreceptors, suggesting a possible trophic effect of the transplant on this layer. Additional studies are needed to improve the efficacy of stem cell transplants in these animal models.
This PDF is available to Subscribers Only