The KCa3.1 blocker TRAM-34 reduces infarction and neurological deficit in a rat model of ischemia/reperfusion stroke

Yi-Je Chen, Girija Raman, Silke Bodendiek, Martha E O'Donnell, Heike Wulff

Research output: Contribution to journalArticle

62 Citations (Scopus)

Abstract

Microglia and brain infiltrating macrophages significantly contribute to the secondary inflammatory damage in the wake of ischemic stroke. Here, we investigated whether inhibition of KCa3.1 (IKCa1/KCNN4), a calcium-activated K + channel that is involved in microglia and macrophage activation and expression of which increases on microglia in the infarcted area, has beneficial effects in a rat model of ischemic stroke. Using an HPLC/MS assay, we first confirmed that our small molecule KCa3.1 blocker TRAM-34 effectively penetrates into the brain and achieves micromolar plasma and brain concentrations after intraperitoneal injection. Then, we subjected male Wistar rats to 90 minutes of middle cerebral artery occlusion (MCAO) and administered either vehicle or TRAM-34 (10 or 40 mg/kg intraperitoneally twice daily) for 7 days starting 12 hours after reperfusion. Both compound doses reduced infarct area by B50% as determined by hematoxylin &eosin staining on day 7 and the higher dose also significantly improved neurological deficit. We further observed a significant reduction in ED1 +-activated microglia and TUNEL-positive neurons as well as increases in NeuN + neurons in the infarcted hemisphere. Our findings suggest that KCa3.1 blockade constitutes an attractive approach for the treatment of ischemic stroke because it is still effective when initiated 12 hours after the insult.

Original languageEnglish (US)
Pages (from-to)2363-2374
Number of pages12
JournalJournal of Cerebral Blood Flow and Metabolism
Volume31
Issue number12
DOIs
StatePublished - Dec 2011

Fingerprint

Microglia
Infarction
Reperfusion
Ischemia
Stroke
Brain
Neurons
Calcium-Activated Potassium Channels
Macrophage Activation
Middle Cerebral Artery Infarction
In Situ Nick-End Labeling
Hematoxylin
Eosine Yellowish-(YS)
Intraperitoneal Injections
Wistar Rats
Macrophages
High Pressure Liquid Chromatography
Staining and Labeling
TRAM 34
Therapeutics

Keywords

  • inflammation
  • KCa3.1
  • MCAO
  • microglia potassium channels
  • middle cerebral artery occlusion with reperfusion
  • TRAM-34

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Clinical Neurology
  • Neurology

Cite this

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title = "The KCa3.1 blocker TRAM-34 reduces infarction and neurological deficit in a rat model of ischemia/reperfusion stroke",
abstract = "Microglia and brain infiltrating macrophages significantly contribute to the secondary inflammatory damage in the wake of ischemic stroke. Here, we investigated whether inhibition of KCa3.1 (IKCa1/KCNN4), a calcium-activated K + channel that is involved in microglia and macrophage activation and expression of which increases on microglia in the infarcted area, has beneficial effects in a rat model of ischemic stroke. Using an HPLC/MS assay, we first confirmed that our small molecule KCa3.1 blocker TRAM-34 effectively penetrates into the brain and achieves micromolar plasma and brain concentrations after intraperitoneal injection. Then, we subjected male Wistar rats to 90 minutes of middle cerebral artery occlusion (MCAO) and administered either vehicle or TRAM-34 (10 or 40 mg/kg intraperitoneally twice daily) for 7 days starting 12 hours after reperfusion. Both compound doses reduced infarct area by B50{\%} as determined by hematoxylin &eosin staining on day 7 and the higher dose also significantly improved neurological deficit. We further observed a significant reduction in ED1 +-activated microglia and TUNEL-positive neurons as well as increases in NeuN + neurons in the infarcted hemisphere. Our findings suggest that KCa3.1 blockade constitutes an attractive approach for the treatment of ischemic stroke because it is still effective when initiated 12 hours after the insult.",
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T1 - The KCa3.1 blocker TRAM-34 reduces infarction and neurological deficit in a rat model of ischemia/reperfusion stroke

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AU - Bodendiek, Silke

AU - O'Donnell, Martha E

AU - Wulff, Heike

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