Cultured neurons expressing phosphorylated tau are more resistant to apoptosis induced by NMDA or serum deprivation.
Apoptosis is a programmed cell death that occurs during the development of the nervous system and in neurodegenerative disorders. Tau protein is a cytoskeletal component that promotes microtubule polymerization and stabilization. Apoptosis was induced in primary neuronal cultures by a prolonged exposure (16 h) to the NMDA (N-methyl-D-aspartate 20 microM) or by serum deprivation. The percentages of apoptotic neurons expressing phosphorylated tau (AT8) immunoreactivity are comparable in control and NMDA-exposed cultures (7.5 +/- 1.9 and 6.9 +/- 1.9%, respectively). At the opposite, the percentage of apoptotic neurons expressing de-phosphorylated tau (tau 1) immunolabelings is dramatically increased in NMDA-treated cultures (X 2.3 of controls). Similar results were also observed 48 h after serum deprivation. These results demonstrate in vitro that under these conditions, resistant and sensitive cortical neurons to apoptosis can be partly differentiated according to their phosphorylated tau immunoreactivities.
Lesort
M
M
Neurobiology and Cellular Pathology Unit (CNRS 1485), Department of Histology and Cell Biology, Faculty of Medicine, Limoges, France.
Blanchard
C
C
Yardin
C
C
Esclaire
F
F
Hugon
J
J
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000502:physiology*; D016895:Culture Media, Serum-Free; D004622:Embryo, Mammalian; D007700:Kinetics; D016202:N-Methylaspartate / Q000494:pharmacology*; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D010766:Phosphorylation; D051381:Rats; D013997:Time Factors; D016875:tau Proteins / Q000096:biosynthesis*
D016895:Culture Media, Serum-Free; D016875:tau Proteins; D016202:N-Methylaspartate