ARS | Publication request: Exploring RPE as a source of photoreceptors: assessing cellular differentiation in vivo

Submitted to: Investigative Opthalmology and Visual Science
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 2006
Publication Date: May 5, 2006
Citation: Liang, L., Zhang, H., Wang, S. 2006. Exploring RPE as a source of photoreceptors: assessing cellular differentiation in vivo [abstract]. Association for Investigative Opthalmology and Visual Science. E-abstract 5541.

Technical Abstract: To evaluate neuroD–induced RPE transdifferentiation into photoreceptor cells in the subretinal space, RPE cells were dissociated, cultured, and guided to transdifferentiate by infecting them with retrovirus RCAS–neuroD, or RCAS–GFP as a control. The cells were then harvested and microinjected into the subretinal space of day 6–7 chick embryos. Line 72 chickens lack cellular receptors for RCAS(A) virus. Thus viral spreading into host cells cannot occur. We found that injected cells from the control RPE culture (infected with RCAS–GFP) integrated into the host RPE tissue when present in a small number. At places where a large number of injected cells were present, multi–layers of RPE–like tissues were formed. The RPE–like tissues comprised of injected and host cells. None of the cells from the control culture expressed visinin or other photoreceptor–specific genes. Compared with the control, fewer cells from the RPE cultures infected with RCAS–neuroD partook in the formation of multi–layered, RPE–like structures. Most of the RCAS–neuroD infected cells remained un–pigmented. A large number of them were Visinin+, and the Visinin+ cells aligned along the newly formed RPE–like structure. Injected cells also expressed red opsin, rhodopsin, RXR , or synaptic protein PSD–95. A small number of cells displayed outer segment–like structures decorated by antibodies to red opsin. Our results indicate that those transdifferentiating cells were intrinsically capable of developing a highly ordered structure. Thus, RPE could potentially serve as a source of photoreceptors cells when guided by an appropriate gene.