Impaired fibrinolysis and traumatic brain injury in mice

J Neurotrauma. 2006 Jun;23(6):976-84. doi: 10.1089/neu.2006.23.976.

Abstract

Traumatic brain injury (TBI) has been associated with intravascular coagulation, which may be a result of thromboplastin released following brain injury. Clots thus formed are lysed by plasmin, which is activated by tissue-type and urokinase-type plasminogen activators (uPA). To evaluate the association between traumatic intravascular coagulation and post-traumatic outcome, uPA knockout (uPA-/-) transgenic mice (n=12) or wild-type littermates (WT; n=12) were anesthetized and subjected to controlled cortical impact (CCI) brain injury. A second group of uPA-/- (n=12) and WT mice (n=12) were subjected to sham injury. Motor function was assessed over 2 weeks using the composite neuroscore test and cognition (learning) was assessed with the Morris Water Maze (MWM) at 2 weeks post-injury, whereupon the animals were sacrificed for cortical lesion volume analysis. Motor function was significantly worse in the brain-injured uPA-/- mice when compared to brain-injured WT mice at 48 h (p<0.05) and one week post-injury (p<0.05). These differences resolved by 2 weeks post-injury. There was no significant difference in post-injury cognitive function between uPA-/- mice and WT mice. However, at 2 weeks post-injury, the brain-injured uPA-/- had a significantly larger volume of cortical tissue loss than their WT counterparts (p<0.05). These results demonstrate that the absence of uPA in mice aggravates acute motor deficit and exacerbates cortical tissue loss following CCI brain injury, and suggests a neuroprotective role of the fibrinolytic process following TBI.

Publication types

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

MeSH terms

  • Animals
  • Brain Injuries / pathology*
  • Brain Injuries / psychology
  • Cognition / physiology
  • Female
  • Fibrinolysis / physiology*
  • Functional Laterality / physiology
  • Immunohistochemistry
  • Intracranial Thrombosis / pathology
  • Male
  • Maze Learning / physiology
  • Mice
  • Mice, Knockout
  • Mice, Transgenic
  • Urokinase-Type Plasminogen Activator / genetics

Substances

  • Urokinase-Type Plasminogen Activator