Allopregnanolone effects on astrogliosis induced by hypoxia in organotypic cultures of striatum, hippocampus, and neocortex.
Perinatal asphyxia occurs in approximately 0.3% full-term newborn babies, and this percentage has not decreased despite medical advances. There are now evidences indicating that neurosteroids are important in neurodevelopment showing neuroprotective effects. We studied the potential protective effect of allopregnanolone (Allo) in vitro using organotypic cultures from neocortex, striatum, and hippocampus. Immunocytochemistry and confocal microscopy showed an increase of the glial fibrillary acidic protein (GFAP) signal in the studied brain areas after hypoxia. Western blot studies supported these results (hippocampus, 193%; neocortex, 306%; and striatum, 231%). Twenty-four-hour pretreatment with Allo showed different effects at the brain areas studied. In the hippocampus and the neocortex, 24-h pretreatment with Allo 5x10(-6) M showed to be neuroprotective as there was a significant decrease of the GFAP signal compared to control cultures exposed to hypoxia. Pretreatment with 5x10(-8) M Allo attenuated the astrogliosis response in the hippocampus and the neocortex in a nonsignificant way. Allo pretreatment at all doses did not show to affect the astrogliosis triggered by hypoxia in the striatum. Cell survival was analyzed by measuring LDH. After 1 h of hypoxia, all cultures showed a nonsignificant increase of LDH, which was greater after 24 h of hypoxia (hippocampus, 180%; striatum-cortex co-cultures, 140%). LDH levels have no changes by Allo pretreatment before hypoxia.


CONCLUSIONS
24 h pretreatment with 5x10(-6) M of Allo does not change neuronal viability but it prevents astrogliosis induced by hypoxia in the hippocampus and the neocortex.
Laboratorio de Neurobiología, Instituto de Biología y Medicina Experimental-CONICET, V. de Obligado 2490, (C1428ADN) Ciudad Autónoma de Buenos Aires, Argentina.
María Sol
MS
Kruse
Mariana
M
Rey
Joaquín
J
Barutta
Héctor
H
Coirini
D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000187:drug effects* / Q000378:metabolism; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D019610:Cytoprotection / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis / Q000378:metabolism; D005911:Gliosis / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D002534:Hypoxia, Brain / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D007770:L-Lactate Dehydrogenase / Q000187:drug effects / Q000378:metabolism; D019579:Neocortex / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D009410:Nerve Degeneration / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology; D018696:Neuroprotective Agents / Q000494:pharmacology* / Q000627:therapeutic use; D009924:Organ Culture Techniques; D011280:Pregnanolone / Q000494:pharmacology* / Q000627:therapeutic use; D016548:Prosencephalon / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley
D015415:Biomarkers; D005904:Glial Fibrillary Acidic Protein; D018696:Neuroprotective Agents; D011280:Pregnanolone; D007770:L-Lactate Dehydrogenase