Development of Müller-Like Cells After Subretinal Transplantation of Feline Red Fluorescent Retinal Progenitors in Abyssinian Cat Hereditary Retinal Degeneration

Abstract

Purpose: : To determine if feline red fluorescent retinal progenitor cells (RPCs) survive transplantation, integrate, and develop into retinal cell types in feline retinal dystrophy.

Methods: : RPCs from neural retinas of embryonic day 45 RFP-transgenic cats were passaged 3 times in DMEM/F12, N2 supplement, GlutaMax, 20ng/ml EGF and 20ng/ml bFGF. Aseptic vitreo-retinal surgery was performed on six 6-17 months-old cats with early stage rod-cone degeneration and 100 µl of donor cells (500,000-750,000) injected subretinally in one eye. Post-op examination included ophthalmoscopy, bilateral full-field ERG, and immunohistochemistry using anti-red fluorescent protein (ARFP), anti-rod opsin, anti-vimentin, anti-ezrin and peanut agglutinin. Four of the cats were euthanized at 6 (n=1), 15 (n=2) and 63 (n=1) days post-op. Posterior eyecups were fixed in 4% paraformaldehyde in Sorensen’s buffer.

Results: : No ERG changes were observed 15-63 days post-op. RFP+ donor profiles were observed within the subretinal space, along the retinotomy, within all cellular layers of the neural retina, and the RPE. Integrated donor cells included examples with striking Müller glial morphology and others suggestive of neuronal cell types. IHC showed co-localization of ARFP together with vimentin and, to lesser extent, anti-rod opsin.

Conclusions: : Feline retinal progenitor cells survive following subretinal transplantation, migrate within the dystrophic feline retina and develop into profiles with features characteristic of the local cellular populations, including Müller glia.

Keywords: retinal degenerations: hereditary • transplantation • retinal glia