IBCN   20355
INSTITUTO DE BIOLOGIA CELULAR Y NEUROCIENCIA "PROFESOR EDUARDO DE ROBERTIS"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Evidences of ischemic tolerance induced by a model of sleep apnea by intermittent hypoxia
Autor/es:
AVILÉS-REYES RX; ANGELO MF; UNSAIN N; VILLARREAL A; BARKER PA; RAMOS AJ
Reunión:
Congreso; Joint Meeting of the Argentine Society for Neurosciences (SAN), and the Argentine Workshop in Neuroscience (TAN).; 2010
Institución organizadora:
Argentine Society for Neurosciences (SAN), and the Argentine Workshop in Neuroscience (TAN).
Resumen:
Sleep apnea (SA) patients show reduced mortality after an ischemic stroke. This clinical observation probably evidences an ischemic tolerance phenomenon. To test this hypothesis, we exposed adult rats or mice (wild type, XIAP-/- or NF-kB reporter) to an experimental model of SA by intermittent hypoxia (IH) by cycling oxygen level (6 min 21% + 6 min 10%; 3 days; 8 h/day), during the sleep phase (Hx group). Control animals were exposed to room air (Nx). A subgroup of animals was subjected to a focal brain ischemia and sacrificed 3 or 7 days post lesion (dpl) (Nx+I or Hx+I). Our results showed that Heat Shock Proteins (HSP) mRNAs were significantly increased in hippocampus of Hx animals. Apoptosis Inhibitor Proteins (c-IAP, XIAP) showed an increase in Hx animals. The activity of NF-êB was increased in Hx animals as shown by the NF-êB reporter transgenic mice and increased levels of IkB. Reduced number of altered neurons with atypical NeuN staining in the ischemic penumbra were observed in Hx+I compared with Nx+I group. Fluoro Jade B staining also showed less number of degenerating neurons in the Hx+I wt animals. XIAP -/- mice lost the protection to a subsequent ischemia induced by Hx exposure. We conclude that IH induces partial protection to a following ischemia, probably involving HSPs and NF-kB target genes specifically XIAP. Grants: CONICET PIP 1728, IBRO RHF; PICT 2008-1590