Müller cell reactivity is attenuated by Stem/progenitor cell therapy in Light Induced Retinal Degeneration.

JUAN J. LÓPEZ-COSTA ; CESAR F. LOIDL; MANUEL REY-FUNES; DANIELA CONTARTESE,; ESTER MARÍA LÓPEZ; MANUEL SOLIÑO; MARIANA BAREIRO

Congreso; NEUROGLIA 2017; 2017

Müller cell reactivity is a component of the retinal response to phototoxicity which was observed in Light induced retinal degeneration (LIRD). Müller cells are important glial cells of the retina which participate in local inflammatory response and also participate in photoreceptor survival by producing neurotrophic factors. The use of Stem/progenitor Cells (SC) in degenerative diseases has become a potential therapeutic strategy. In the retina, SC are localized in Ciliary Muscle Zone (CMZ) but they are unable to regenerate retinal cells in mammalians. The aim of the present work was to isolate and reproduce retinal SCs in neurospheres (NS) and to intravitreally inject the eyes of light induced degenerated retinas to study their effect on Müller cell gliosis.Retinal stem cells were isolated from the CMZ of neonatal rat retinas. Cells were mechanically dissociated and were cultured in a NS promoting medium containing: DMEN-F12, B27, penicillin/streptomycin, bFGF and EGF. NS were immunostained with Nestin antibody (Sigma) in order to demonstrate the presence of undifferentiated SCs.Sprague Dawley rats were submitted to continuous illumination (12000 lux) for 1, 2, 5 or 7 days. Then rats were intravitreally injected in one eye with 5ul of 5x105 SC. Contralateral eyes were injected with vehicle as control. After one week eyes were processed by immunocytochemistry using a GFAP primary antibody (DAKO). GFAP immunoreactive areas were quantified. Data were analysed using Student´s t test. Stem cell treated retinas showed a trend of decrease in GFAP immunoreactivity at all the studied timepoints. Our results suggest that Müller cell reactivity is reduced by intravitreal injection of SCs. We postulate that SC could secrete trophic factors with beneficial anti-inflammatory properties. The inhibition of Intermediate filament expression may provide a permissive environment for the integration of retinal implants. In addition, the study of Müller cell reactivity could be used as a marker of tissue improvement.