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Evaluating Cell Death Signaling by Immunofluorescence in a Rat Model of Ischemic Stroke
11:32

Evaluating Cell Death Signaling by Immunofluorescence in a Rat Model of Ischemic Stroke

Published on: January 3, 2025

Death-associated protein kinase is activated by dephosphorylation in response to cerebral ischemia

Mehrdad Shamloo1, Liza Soriano, Tadeusz Wieloch

  • 1AGY Therapeutics, Inc., South San Francisco, California 94080, USA. mshamloo@agyinc.com

The Journal of Biological Chemistry
|October 6, 2005
PubMed

Insights

Death-associated protein kinase (DAPK) activation, through dephosphorylation and proteolysis, contributes to ischemic neuronal death. Inhibiting DAPK demonstrates neuroprotective effects in stroke models.

Area of Science:

  • Neuroscience
  • Molecular Biology
  • Biochemistry

Background:

  • Death-associated protein kinase (DAPK) is a serine/threonine kinase implicated in neuronal cell death.
  • Calcium calmodulin-dependent regulation of DAPK suggests a role in cellular stress responses.

Purpose of the Study:

  • To elucidate the role and activation mechanisms of DAPK in ischemic neuronal injury.
  • To investigate the therapeutic potential of DAPK inhibition in stroke models.

Main Methods:

  • In situ hybridization to assess DAPK mRNA expression in ischemic brain.
  • In vitro studies using primary cortical neurons subjected to oxygen-glucose deprivation or NMDA toxicity.
  • Pharmacological inhibition of calcineurin and NMDA receptors.
  • Assessment of DAPK dephosphorylation and proteolytic processing.
  • Evaluation of a selective DAPK inhibitor in in vitro and in vivo ischemic models.

Main Results:

  • DAPK mRNA is upregulated after global ischemia but downregulated after focal ischemia.
  • DAPK is rapidly dephosphorylated and activated in ischemic conditions, both in vivo and in vitro.
  • NMDA receptor activation and calcineurin are involved in DAPK dephosphorylation.
  • DAPK undergoes cathepsin-mediated proteolysis post-ischemia.
  • Selective DAPK inhibition confers neuroprotection against ischemic injury.

Conclusions:

  • DAPK activation, via NMDA receptor-mediated calcium influx and calcineurin, plays a critical role in ischemic neuronal death.
  • DAPK is a promising therapeutic target for stroke treatment.

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