Role of Muller glial cells in the generation of neuroblasts and photoreceptor-like cells. Apoptosis prevention by sphingosine 1 phosphate

SIMÓN M. VICTORIA; DE GENARO PABLO; ABRAHAN CAROLINA; DE LOS SANTOS, BEATRIZ; ROTSTEIN, NORA; POLITI, LUIS

Huerta Grande

Otro; I Reunión Conjunta de Neurociencias (IRCN); 2009

Soc Argentina de Investigación en Neurociencias (SAN) y Taller Argentino de Neurociencias (TAN)

Müller glial cells (MGC) are stem cells in the vertebrate retina and might be used to replace neurons lost in neurodegenerative diseases. We have shown that rat retina progenitor round cells (PRC) in co-culture with MGC preserve their proliferative state, can be re-seeded and can then adopt a photoreceptor (PHR) fate in secondary co-cultures. Here we analyzed whether MGC preserved proliferative PRC in successive passages, and then induced these PRC to differentiation as mature PHRs. Flow cytometry analyses established that about 5% of total round cells (RC) in secondary co-cultures were PRC, which showed stem cell markers, such as 5-bromo-2-deoxyuridine uptake and Pax6 expression, even after four passages. MGC induced PRC in secondary co-cultures to differentiate as PHRs: RC expressed Tuj1 (an early neuronal marker) and Western blot analysis revealed acetylated tubulin (an axon marker) levels augmented with time in vitro. PHR-like cells expressed Crx (an early PHR marker), opsin and peripherin (a disc structural protein) and responded to light by diminishing their intracellular cGMP levels, evidencing they had an active phototransduction pathway. Our results suggest that MGC maintain and/or generate proliferative PRC and later instruct them to differentiate into functional PHRs.