Effects of hypoxia on stress proteins in the piglet brain at birth.
Newborn piglets were submitted to normobaric hypoxia (5% O2, 95% N2) for either 1 or 4 h. The effects of hypoxia on the neonatal brain were characterized through a time-course analysis of levels of various proteins such as heat shock proteins (HSP27, 70, and 90), hypoxia inducible factor-1alpha (HIF-1alpha), neuronal nitric oxide synthase (nNOS), hemeoxygenase-2 (HO-2), and caspase-3. The expression of these proteins was determined at different stages of recovery up to 72 h in cerebellum, cortex, and hippocampus by Western blot analysis in hypoxic maintained animals that were made hypoxic at either 20 or 37 degrees C. In all regions of the brain, HIF-1alpha and HSP27 expression were strongly increased until 22 h of recovery. No significant changes were observed for HSP70, HSP90, and HO-2. A small elevation of expression of nNOS was observed at early stages in the cerebellum and the cortex with no change in the hippocampus. Expression of caspase 3 was strongly increased in the cortex 24 and 48 h after hypoxia but unchanged in the hippocampus. These results are presented in terms of the porcine model of nonischemic hypoxia and its delayed neuronal effects on the cerebral outcome. Because of their recently established biochemical and functional interactions, the expression of the main HSPs, HIF-1alpha, nNOS, and caspase-3 after hypoxia are delineated.
Chiral
Magali
M
Sciences et Productions Animales, Agrocampus, 65, rue de Saint-Brieuc, CS 84215, 35042 Rennes Cedex, France.
Grongnet
Jean-François
JF
Plumier
Jean-Christophe
JC
David
Jean Claude
JC
D000818:Animals; D000831:Animals, Newborn; D001831:Body Temperature; D001921:Brain / Q000378:metabolism*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002531:Cerebellum / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism; D051547:Heme Oxygenase-1; D006624:Hippocampus / Q000378:metabolism; D002534:Hypoxia, Brain / Q000378:metabolism*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D019001:Nitric Oxide Synthase / Q000378:metabolism; D010100:Oxygen / Q000097:blood; D034421:Sus scrofa; D014157:Transcription Factors / Q000378:metabolism
D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D014157:Transcription Factors; D019001:Nitric Oxide Synthase; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; C105245:heme oxygenase-2; D053148:Caspase 3; D020169:Caspases; D010100:Oxygen