P2Y1 RECEPTORS MODULATE PROLIFERATIVE ACTIVITY DURING RETINAL REGENERATION

BEJARANO, CLAUDIO ALEJANDRO; LAMBERTI, MELISA L.; MEDRANO, MATÍAS PEDRO; FAILLACE, MARÍA PAULA

Fos de Iguazu

Congreso; PANAM - 1st PanAmerican Congress of Physiological Sciences; 2014

PANAM

During retinal regeneration, a population of Müller glia reenters the cell cycle, between 24-72h following injury to generate neuronal and glial progenitor cells (PC) that continue to proliferate, migrate and differentiate into different cell types. We study the78role of endogenous extracellular nucleotides (EN) and purinergic receptors P2Y1 (P2Y1R) in regulating the proliferation of Müller cells and PC after intravitreal injections of 12 μM ouabain (OUA) that causes cell death in all retinal layers of zebrafish. Two batches of fish were injected either with OUA (injury) or saline (SF, control) on day 0, then SF 1-3 days post-injury (dpi) and SF + BrdU (20μg/μl) 4-7 dpi. A third group was injected with OUA day 0, MRS2179 (P2Y1R antagonist) 1-3 dpi and MRS2179 + BrdU 4-7 dpi. Other groups were injected with OUA or SF on day 0, and then injected with BrdU 5h prior to euthanasia at 2 and 6 dpi. Double immunofluorescence was performed to detect BrdU- and P2Y1R-positive cells at 7 dpi. We detected and quantified the mRNA levels for purinergic receptors by standard and quantitative RT-PCR. Protein and mRNA levels of P2Y1R showed a significant increase in the proliferative phase post injury. Moreover, the spatial distribution of P2Y1R was modified. Furthermore, there was a significant decrease of proliferation in the injured retinas treated with MRS2179. Our results indicated that EN action on P2Y1R was critical for triggering and maintaining stem cell and PC proliferation for retinal regeneration.