An activated protein C analog with reduced anticoagulant activity extends the therapeutic window of tissue plasminogen activator for ischemic stroke in rodents

Stroke. 2012 Sep;43(9):2444-9. doi: 10.1161/STROKEAHA.112.658997. Epub 2012 Jul 17.


Background and purpose: Tissue plasminogen activator (tPA) is the only approved therapy for acute ischemic stroke. However, tPA has a brief therapeutic window. Its side effects include intracerebral bleeding and neurotoxicity. Therefore, a combination therapy with tPA and agents that can extend the therapeutic window of tPA and/or counteract its side effects are warranted. Here, we studied whether 3K3A-APC, a neuroprotective analog of activated protein C with reduced anticoagulant activity, can enhance the therapeutic effects of tPA in models of ischemic stroke in rodents.

Methods: Human recombinant tPA (10 mg/kg), alone or in combination with human recombinant 3K3A-APC (2 mg/kg), was administered intravenously 4 hours after proximal or distal transient middle cerebral artery occlusion in mice and embolic stroke in rats. The 3K3A-APC was additionally administered for 3 to 4 consecutive days after stroke. The neuropathological and neurological analyses were performed at 1 to 7 days after stroke.

Results: In all models, tPA alone had no effects on the infarct volume or behavior (ie, neurological score, foot-fault, forelimb asymmetry, adhesive removal) compared with vehicle. The tPA and 3K3A-APC combination therapy reduced the infarct volume 24 hours and 7 days after proximal or distal transient middle cerebral artery occlusion in mice and 7 days after embolic stroke in rats by 65%, 63%, and 52%, respectively, significantly (P<0.05) improved behavior and eliminated tPA-induced intracerebral microhemorrhages.

Conclusions: The 3K3A-APC extends the therapeutic window of tPA for ischemic stroke in rodents. Therefore, this combination therapy also should be considered for treating stroke in humans.

Publication types

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

MeSH terms

  • Animals
  • Anticoagulants / therapeutic use*
  • Brain / pathology
  • Brain Ischemia / drug therapy*
  • Cerebral Hemorrhage / drug therapy
  • Cerebral Hemorrhage / pathology
  • Fibrinolytic Agents / adverse effects
  • Fibrinolytic Agents / therapeutic use*
  • Hemoglobins / metabolism
  • Infarction, Middle Cerebral Artery / drug therapy
  • Infarction, Middle Cerebral Artery / pathology
  • Intracranial Embolism / drug therapy
  • Intracranial Embolism / pathology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Neurologic Examination
  • Protein C / analogs & derivatives*
  • Protein C / therapeutic use*
  • Rats
  • Rats, Wistar
  • Stroke / drug therapy*
  • Tissue Plasminogen Activator / administration & dosage
  • Tissue Plasminogen Activator / therapeutic use*


  • Anticoagulants
  • Fibrinolytic Agents
  • Hemoglobins
  • Protein C
  • Tissue Plasminogen Activator