Decrease of Tau hyperphosphorylation by 17β estradiol requires sphingosine kinase in a glutamate toxicity model

Neurochem Res. 2009 Dec;34(12):2206-14. doi: 10.1007/s11064-009-0017-6.

Abstract

Several studies have linked estrogens with sphingosine kinase (SphK) activity, enzyme responsible of sphingosine-1-phosphate synthesis (S-1P), however their possible interaction in the nervous system is not documented yet. In the present study, we developed a glutamate toxicity model in SH-SY5Y cells to evaluate the possible effect of the inhibition of SphK activity on the protective capability of 17β-estradiol (E2). Glutamate induced cytoskeletal actin changes associated to cytotoxic stress, significant increase of apoptotic-like nuclear fragmentation, Tau hyperphosphorylation and increase of p25/p35 cleavage. These effects were prevented by E2 pre-treatment during 24 h. Although the inhibition of SphK did not block this protective effect, significantly increased Tau hyperphosphorylation by glutamate, in a way that was not reverted by E2. Our results suggest that the decrease of glutamate-induced Tau hyperphosphorylation by 17β-estradiol requires SphK.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / drug effects
  • Apoptosis / drug effects
  • Cell Line, Tumor
  • DNA Fragmentation / drug effects
  • Estradiol / pharmacology*
  • Glutamic Acid / toxicity*
  • Humans
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • Neuroblastoma / metabolism
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphorylation / drug effects
  • Phosphotransferases (Alcohol Group Acceptor) / antagonists & inhibitors
  • Phosphotransferases (Alcohol Group Acceptor) / physiology*
  • Proto-Oncogene Proteins c-akt / metabolism
  • tau Proteins / metabolism*

Substances

  • Actins
  • tau Proteins
  • Glutamic Acid
  • Estradiol
  • Phosphatidylinositol 3-Kinases
  • Phosphotransferases (Alcohol Group Acceptor)
  • sphingosine kinase
  • Proto-Oncogene Proteins c-akt
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3