DNA-PK promotes the survival of young neurons in the embryonic mouse retina.

Enrique J de La Rosa (1) , Jimena Baleriola (1) , Teresa Suárez (1)

1 Department of Cellular and Molecular Medicine

Programmed cell death is a crucial process in neural development that affects mature neurons and glial cells, as well as proliferating precursors and recently born neurons at earlier stages. However, the regulation of the early phase of neural cell death and its function remain relatively poorly understood. In mouse models defective in homologous recombination (HR) or non-homologous end-joining (NHEJ), which are both DNA double-strand break (DSB) repair pathways, there is massive cell death during neural development, even leading to embryonic lethality. These observations suggest that natural DSBs occur frequently in the developing nervous system. Here we have found that several components of DSB repair pathways are activated in the developing mouse retina at stages that coincide with the onset of neurogenesis. In short-term organotypic retinal cultures, we confirmed that the repair pathways can be modulated pharmacologically. Indeed, inhibiting DNA-PKcs, which is involved in NHEJ, with NU7026 increased caspase-dependent cell death and selectively reduced the neuron population. This observation concurs with an increase in the number of apoptotic neurons found after NU7026 treatment, as also observed in the embryonic scid mouse retina, a mutant that lacks DNA-PKcs activity. Therefore, our results implicate the generation of DSB and DNA-PK-mediated repair in neurogenesis in the developing retina.

Mots clés: DNA; damage; apoptosis; neurogenesis; retina

Enrique J de La Rosa, Jimena Baleriola, Teresa Suárez. DNA-PK promotes the survival of young neurons in the embryonic mouse retina.. Cell Death and Differentiation, 2010, ⟨10.1038/cdd.2010.46⟩. ⟨hal-00533511⟩