Induction of ERK1/2 and histone H3 phosphorylation within the outer stripe of the outer medulla of the Eker rat by 2,3,5- Tris-(Glutathion-S-yl) hydroquinone

Jing Dong, Jeffrey I. Everitt, Serrine S. Lau, Terrence J. Monks

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

2,3,5-tris-(glutathion-S-yl)-h ydroquinone (TGHQ), a metabolite of hydroquinone (HQ), generates reactive oxygen species (ROS) in cultured renal epithelial cells and binds to tissue macromolecules within the rat kidney. The potential mechanisms by which TGHQ induces nephrotoxicity and nephrocarcinogenesis have been examined in cell culture models, but less is known concerning the molecular mechanisms of TGHQ-induced nephrotoxicity in vivo. In LLC-PK1 cells, TGHQ induces phosphorylation of both mitogen-activated protein kinase and histone H3, which likely promotes inappropriate chromatin condensation and mitotic catastrophe. Using the Eker (Tsc-2 mutant) rat as a model, we show by immunohistochemistry that TGHQ (7.5 μmol/kg) selectively induces ERK1/2 phosphorylation within the outer stripe of the outer medulla (OSOM) of the kidney. ERK1/2 phosphorylation is time-dependant, occurring as early as 1 h following treatment, and reaching maximal levels by 4 h. Subsequently, ERK1/2 phosphorylation returns to baseline levels by 24 h post treatment. ERK1/2 phosphorylation was confirmed by western blot analysis of OSOM tissue. Increases in histone H3 phosphorylation occurred subsequent to ERK1/2 phosphorylation (8 h), and reached a peak by 24 h, coincident with histological evidence of tissue necrosis. In contrast to studies in cell culture, neither JNK/SAPK nor p38 MAPK phosphorylation were significantly altered after TGHQ administration in vivo, as evidenced by western blot and immunohistochemical analyses. These data indicate that activation of the ERK1/2 pathway precedes overt cytotoxicity and that the signaling pathways activated by TGHQ in vivo and in vitro differ.

Original languageEnglish (US)
Pages (from-to)350-357
Number of pages8
JournalToxicological Sciences
Volume80
Issue number2
DOIs
StatePublished - Aug 2004
Externally publishedYes

Keywords

  • Eker rats
  • Histone H3
  • MAPK
  • ROS
  • TGHQ

ASJC Scopus subject areas

  • Toxicology

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