Inhibition of phospholipase A2 increases tau phosphorylation at Ser214 in embryonic rat hippocampal neurons.
BACKGROUND
Arachidonic acid is released from cellular membranes by the action of phospholipase A(2) (PLA(2)) and is implicated in microtubule-associated protein Tau phosphorylation. Tau hyperphosphorylation affects its ability to stabilize microtubules.


OBJECTIVE
To determine the effect of PLA(2) inhibition on the phosphorylation state of Tau phosphoepitopes in primary cultures of hippocampal neurons.


METHODS
4 DIC neurons were incubated at different concentrations of methyl-arachidonylfluorophosphonate (MAFP), an irreversible inhibitor of cPLA(2) and iPLA(2). Changes on Tau phosphorylation were determined by Western blotting with a panel of anti-Tau antibodies (C-terminal, Ser199/202, Ser202/205, Ser396 and Ser214).


RESULTS
The Ser214 site was hyperphosphorylated upon MAFP treatment. Significant differences were observed with 10 microM (p=0.01), 50 microM (p=0.01) and 100 microM (p=0.05) of MAFP. Less-intense changes were found in other phosphoepitopes.


CONCLUSIONS
The present findings indicate that the phosphorylation of Ser214 is regulated by c- and/or iPLA(2), whereas other phosphoepitopes primarily regulated by GKS3b were not affected.
De-Paula
Vanessa J
VJ
Laboratory of Neuroscience LIM-27, Department and Institute of Psychiatry, Faculty of Medicine, University of Sao Paulo, Brazil.
Schaeffer
Evelin L
EL
Talib
Leda L
LL
Gattaz
Wagner F
WF
Forlenza
Orestes V
OV
D000818:Animals; D045163:Antibodies, Phospho-Specific; D001095:Arachidonic Acids / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000196:embryology* / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D063065:Organophosphonates / Q000494:pharmacology; D064801:Phospholipase A2 Inhibitors; D054512:Phospholipases A2, Calcium-Independent / Q000037:antagonists & inhibitors; D010766:Phosphorylation / Q000187:drug effects; D011499:Protein Processing, Post-Translational / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D012694:Serine / Q000378:metabolism*; D016875:tau Proteins / Q000378:metabolism*
D045163:Antibodies, Phospho-Specific; D001095:Arachidonic Acids; D004791:Enzyme Inhibitors; D063065:Organophosphonates; D064801:Phospholipase A2 Inhibitors; C104810:methyl arachidonylfluorophosphonate; D016875:tau Proteins; D012694:Serine; D054512:Phospholipases A2, Calcium-Independent