Hypoxia-induced cell death and activation of pro- and anti-apoptotic proteins in developing chick optic lobe.
Exposure of the CNS to hypoxia is associated with cell death. Our aim was to establish a temporal correlation between cellular and molecular alterations induced by an acute hypoxia evaluated at different post-hypoxia (p-h) times and at two stages of chick optic lobe development: embryonic days (ED) 12 and 18. TUNEL assays at ED12 disclosed a significant increase (300%) in pyknotic cells at 6 h p-h, while at ED18 no morphological changes were observed in hypoxic versus controls. At ED12 there was a significant increase (48%) in Bcl-2 levels at the end of the hypoxic treatment, followed by a significant increase of active caspase-9 (49%) and active caspase-3 (58%) at 30 and 60 min p-h, respectively, while at ED18 no significant changes were observed. These findings indicate that prenatal hypoxia produces an equilibrated imbalance in both pro- and anti-apoptotic proteins that culminates in a process of cell death, present at earlier stages of development.
Vacotto
Marina
M
Facultad de Medicina, Instituto de Biología Celular y Neurociencias, Prof. E. De Robertis, Universidad de Buenos Aires, Paraguay 2155, 1121 Buenos Aires, Argentina.
Paz
Dante
D
de Plazas
Sara Fiszer
SF
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism*; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D002642:Chick Embryo; D000860:Hypoxia; D020287:In Situ Nick-End Labeling; D009899:Optic Lobe, Nonmammalian / Q000166:cytology / Q000254:growth & development*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism
D051017:Apoptosis Regulatory Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D053148:Caspase 3; D053453:Caspase 9