The functional roles of constitutively active calcineurin in delayed neuronal death after brain ischemia

Norifumi Shioda, Kohji Fukunaga

Research output: Contribution to journalReview articlepeer-review

7 Citations (Scopus)

Abstract

Excessive Ca2+ elevation resulting from activation of NMDA and other Ca2+ channels is thought to play a pivotal role in pathologic events following brain ischemia. The Ca2+ elevation directly triggers necrotic or apoptotic cell death through activation of Ca2+/ calmodulin (CaM)-dependent enzymes, including calcineurin (CaN). CaN, a Ca 2+/CaM-dependent serine/threonine protein phosphatase, partly mediates apoptosis associated with neuronal death. In a mouse middle cerebral artery occlusion (MCAO) model, calpain, a Ca2+-dependent cysteine protease, converted CaN to the constitutively active form of 48 kDa in vivo. The calpain-induced CaN activation mediated delayed neuronal death through translocation of nuclear factor of activated T-cells (NFAT) and FKHR, a forkhead box class O family member (FOXO) into neuronal nuclei after brain ischemia. The FKHR activation occurred through decreased Akt activity with concomitant dephosphorylation by constitutively active CaN. Thereafter, FKHR formed a complex with CaN and in turn translocated into nuclei after brain ischemia. After nuclear translocation of NFAT and FKHR, the transcription factors stimulated expression of Fas-ligand by binding to its promoter regions. Taken together, constitutively active CaN mediates delayed neuronal death through Fas-ligand expression via up regulation of both NFAT and FKHR transcriptional activity in brain ischemia.

Original languageEnglish
Pages (from-to)13-20
Number of pages8
JournalYakugaku Zasshi
Volume131
Issue number1
DOIs
Publication statusPublished - 2011 Jan

Keywords

  • Brain ischemia
  • Calcineurin
  • Calpain
  • Fas-ligand

ASJC Scopus subject areas

  • Pharmacology
  • Pharmaceutical Science

Fingerprint Dive into the research topics of 'The functional roles of constitutively active calcineurin in delayed neuronal death after brain ischemia'. Together they form a unique fingerprint.

Cite this