3alfa;-Hydroxy-6-19-oxidopregn-4-ene-20-one (NS1) confers neuroprotection against hypoxia in organotypic cultures of hippocampus and cerebral cortex

KRUSE, M.S.; REY, M.; VELEIRO, A.S.; BURTON, G.; COIRINI, H.

Panamá

Workshop; International Conference of Drug Discovery for Brain Disorders: Neurochemical complexes and drug targets; 2011

In vivo studies have revealed that hypoxia induced long term neuronal and glial changes. Here we studied the effects of  allopregnanolone (Allo) or its synthetic analogue, the steroid 6-19 oxo-pregnene (Ns1), on organotypic cultures from cerebral cortex and hippocampus submitted to hypoxia.  We first study the integrity of the 160 and 200 kDa neurofilament isoforms (NF-160, NF-200) after hypoxia by immunoblot. 1 h hypoxia significantly decreased cortical NF-160 (42.3% p<0.005) and hippocampal NF-200 (31.3% p<0.05). NF-160 had an slight non-significant decreased in hippocampus (18.2%) while there were no changes in cortical NF-200 by hypoxia. To evaluate the neuroprotection properties of Allo or Ns1, the cultures were treated with these steroids 24 h prior to hypoxia and during the time of hypoxic insult. In cortex, Allo (5 mM) slightly attenuated NF-160 decreased induced by hypoxia, while Ns1 (5 mM) completly reverted NF-160 decreased (p<0.05). In hippocampus both Allo and Ns1 attenuated the NF-200 hypoxic decreased but the effect was not significant. The astroglial reaction (GFAP) was also evaluated in these cultures. 1h hypoxia increased GFAP signal (hippocampus, 193%; neocortex, 306% p<0.01). 24-h pretreatment with Allo or Ns1 (5 mM) showed to be neuroprotective as there were a significant decrease of the GFAP signal compared to control cultures exposed to hypoxia. These results suggest that Allo and Ns1 could prevent or attenuate neuronal damage triggered by hypoxia and make them suitable candidates for future therapeutic applications (UBACYT M012 y PICT727).