Methylglyoxal induces tau hyperphosphorylation via promoting AGEs formation

Neuromolecular Med. 2012 Dec;14(4):338-48. doi: 10.1007/s12017-012-8191-0. Epub 2012 Jul 14.

Abstract

The hyperphosphorylated tau is a major protein component of neurofibrillary tangle, which is one of hallmarks of Alzheimer's disease (AD). While the level of methylglyoxal (MG) is significantly increased in the AD brains, the role of MG in tau phosphorylation is still not reported. Here, we found that MG could induce tau hyperphosphorylation at multiple AD-related sites in neuroblastoma 2a cells under maintaining normal cell viability. MG treatment increased the level of advanced glycation end products (AGEs) and the receptor of AGEs (RAGE). Glycogen synthesis kinase-3β (GSK-3β) and p38 MAPK were activated, whereas the level and activity of JNK, Erk1/2, cdk5, and PP2A were not altered after MG treatment. Simultaneous inhibition of GSK-3β or p38 attenuated the MG-induced tau hyperphosphorylation. Aminoguanidine, a blocker of AGEs formation, could effectively reverse the MG-induced tau hyperphosphorylation. These data suggest that MG induces AD-like tau hyperphosphorylation through AGEs formation involving RAGE up-regulation and GSK-3β activation and p38 activation is also partially involved in MG-induced tau hyperphosphorylation. Thus, targeting MG may be a promising therapeutic strategy to prevent AD-like tau hyperphosphorylation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alzheimer Disease / metabolism
  • Animals
  • Cell Line, Tumor / drug effects
  • Cell Line, Tumor / metabolism
  • Enzyme Activation / drug effects
  • Glycation End Products, Advanced / antagonists & inhibitors
  • Glycation End Products, Advanced / metabolism*
  • Glycogen Synthase Kinase 3 / antagonists & inhibitors
  • Glycogen Synthase Kinase 3 / metabolism
  • Glycogen Synthase Kinase 3 beta
  • Guanidines / pharmacology
  • Mice
  • Neuroblastoma / pathology
  • Phosphorylation / drug effects
  • Protein Kinases / metabolism
  • Protein Processing, Post-Translational / drug effects
  • Pyruvaldehyde / pharmacology*
  • Receptor for Advanced Glycation End Products
  • Receptors, Immunologic / biosynthesis
  • Receptors, Immunologic / genetics
  • Up-Regulation / drug effects
  • p38 Mitogen-Activated Protein Kinases / antagonists & inhibitors
  • p38 Mitogen-Activated Protein Kinases / metabolism
  • tau Proteins / metabolism*

Substances

  • Glycation End Products, Advanced
  • Guanidines
  • Mapt protein, mouse
  • Receptor for Advanced Glycation End Products
  • Receptors, Immunologic
  • tau Proteins
  • Pyruvaldehyde
  • Protein Kinases
  • Glycogen Synthase Kinase 3 beta
  • Gsk3b protein, mouse
  • p38 Mitogen-Activated Protein Kinases
  • Glycogen Synthase Kinase 3
  • pimagedine