Subcellular localization patterns of transglutaminase 2 in astrocytes and neurons are differentially altered by hypoxia

Neuroreport. 2017 Dec 13;28(18):1208-1214. doi: 10.1097/WNR.0000000000000895.

Abstract

The multifunctional protein transglutaminase 2 (TG2) has been widely implicated as a modulator of cellular viability. Specifically, TG2 expression is beneficial to neuronal survival following an ischemic injury, whereas the opposite is true in astrocytes. Furthermore, its role in mediating cell death and survival processes has been suggested to be dependent on its subcellular localization. Therefore, the aim of this study was to examine the subcellular localization patterns of neuronal and astrocytic TG2 in ischemia-relevant conditions. We found that nuclear levels of TG2 were significantly increased in neurons, but reduced in astrocytes, in response to hypoxia. In addition, there were no changes in extracellular TG2 in astrocytes exposed to hypoxia. Thus, these findings demonstrate a difference in the subcellular localization pattern of TG2 in neurons and astrocytes in ischemia-relevant conditions and provide further avenues for investigation into the role of TG2 in mediating cellular viability.

MeSH terms

  • Animals
  • Animals, Newborn
  • Astrocytes / ultrastructure*
  • Biotinylation
  • Cell Nucleus / enzymology
  • Cells, Cultured
  • Cerebral Cortex
  • Culture Media, Serum-Free
  • Cytosol / enzymology
  • Female
  • GTP-Binding Proteins / metabolism*
  • Hypoxia / pathology*
  • Hypoxia / physiopathology
  • Mice
  • Neurons / ultrastructure*
  • Pregnancy
  • Protein Glutamine gamma Glutamyltransferase 2
  • Rats
  • Rats, Sprague-Dawley
  • Subcellular Fractions / enzymology*
  • Transglutaminases / metabolism*

Substances

  • Culture Media, Serum-Free
  • Tgm2 protein, rat
  • Protein Glutamine gamma Glutamyltransferase 2
  • Transglutaminases
  • GTP-Binding Proteins