Glutamate-induced increases in transglutaminase activity in primary cultures of astroglial cells

Brain Res. 2003 Jul 18;978(1-2):24-30. doi: 10.1016/s0006-8993(03)02725-2.


Glutamate exposure of astroglial cells caused ligand-gated channel receptor activation, associated with excitotoxic cell response. We investigated the effects of 24 h glutamate exposure on transglutaminase in astrocytes primary cultures at 7, 14, and 21 days in vitro (DIV). Increases in enzyme activity were observed as a function of cell differentiation stage in glutamate-treated cultures. These effects were significantly reduced when GYKI 52466, an AMPA/KA receptors inhibitor, was added to the culture medium prior to incubation with glutamate. Microscopy observation on transglutaminase-mediated, fluorescent dansylcadaverine incorporation in living cells was consistent with these results. Western blotting analysis with monoclonal antibody showed that glutamate also up-regulated tissue transglutaminase expression, which reached the highest values in 14 DIV cultures. Confocal laser scanning microscopy analysis of immunostained astroglial cells showed a mainly cytoplasmic localisation of the enzyme both in control and treated cultures; nevertheless, counterstaining with the nuclear dye acridine orange demonstrated the presence of tissue transglutaminase also into the nucleus of glutamate-exposed and 21 DIV cells. The increases in enzyme expression and localisation in the nucleus of glutamate-treated astroglial cells may be part of biochemical alterations induced by excitotoxic stimulus.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Animals, Newborn
  • Anti-Anxiety Agents / pharmacology
  • Astrocytes / drug effects*
  • Astrocytes / metabolism
  • Benzodiazepines*
  • Blotting, Western / methods
  • Cadaverine / analogs & derivatives*
  • Cadaverine / metabolism
  • Cells, Cultured
  • Dose-Response Relationship, Drug
  • Drug Interactions
  • Excitatory Amino Acid Agents / pharmacology*
  • Excitatory Amino Acid Antagonists / pharmacology
  • Glutamate-Ammonia Ligase / analysis
  • Glutamic Acid / pharmacology*
  • Immunohistochemistry / methods
  • Microscopy, Confocal / methods
  • Rats
  • Rats, Wistar
  • Time Factors
  • Transglutaminases / analysis
  • Transglutaminases / metabolism*


  • Anti-Anxiety Agents
  • Excitatory Amino Acid Agents
  • Excitatory Amino Acid Antagonists
  • GYKI 52466
  • Benzodiazepines
  • Glutamic Acid
  • Transglutaminases
  • Glutamate-Ammonia Ligase
  • monodansylcadaverine
  • Cadaverine