Thrombin mutant W215A/E217A treatment improves neurological outcome and reduces cerebral infarct size in a mouse model of ischemic stroke

Stroke. 2011 Jun;42(6):1736-41. doi: 10.1161/STROKEAHA.110.603811. Epub 2011 Apr 21.


Background and purpose: Treatment of ischemic stroke by activation of endogenous plasminogen using tissue plasminogen activator is limited by bleeding side effects. In mice, treatment of experimental ischemic stroke with activated protein C improves outcomes; however, activated protein C also has bleeding side effects. In contrast, activation of endogenous protein C using thrombin mutant W215A/E217A (WE) is antithrombotic without hemostasis impairment in primates. Therefore, we investigated the outcome of WE-treated experimental ischemic stroke in mice.

Methods: The middle cerebral artery was occluded with a filament for 60 minutes to induce ischemic stroke. Vehicle, recombinant WE, or tissue plasminogen activator was administered during middle cerebral artery occlusion or 2 hours after middle cerebral artery occlusion. Neurological performance was scored daily. Intracranial bleeding and cerebral infarct size, defined by 2,3,5-triphenyltetrazolium chloride exclusion, were determined on autopsy. Hemostasis was evaluated using tail bleeding tests.

Results: WE improved neurological performance scores, increased laser Doppler flowmetry-monitored post-middle cerebral artery occlusion reperfusion of the parietal cortex, and reduced 2,3,5-triphenyltetrazolium chloride-defined cerebral infarct size versus vehicle controls. However, unlike tissue plasminogen activator, WE did not increase tail bleeding or intracranial hemorrhage.

Conclusions: WE treatment is neuroprotective without hemostasis impairment in experimental acute ischemic stroke in mice and thus may provide an alternative to tissue plasminogen activator for stroke treatment.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anticoagulants / therapeutic use*
  • Brain Ischemia* / drug therapy
  • Brain Ischemia* / pathology
  • Cerebral Infarction / drug therapy*
  • Cerebral Infarction / pathology*
  • Cerebral Infarction / physiopathology
  • Disease Models, Animal
  • Hemostasis
  • Humans
  • Infarction, Middle Cerebral Artery / drug therapy
  • Laser-Doppler Flowmetry
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mutation
  • Stroke* / drug therapy
  • Stroke* / pathology
  • Thrombin / genetics*
  • Thrombin / therapeutic use*
  • Tissue Plasminogen Activator / therapeutic use
  • Treatment Outcome


  • Anticoagulants
  • Thrombin
  • Tissue Plasminogen Activator