Intracerebral hemorrhage-induced neuronal death

Neurosurgery. 2001 Apr;48(4):875-82; discussion 882-3. doi: 10.1097/00006123-200104000-00037.

Abstract

Objective: The mechanisms underlying neural injury in intracerebral hemorrhage (ICH) remain uncertain. The present two-part study investigated cell death in the region of ICH and its association with caspase-3 activation.

Methods: ICH was produced in adult rats by injection of 100 microl of autologous blood or saline into the right basal ganglia. The animals' brains were removed at 6 hours or at 1, 3, 7, or 14 days after hemorrhage. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin in situ nick end-labeling (TUNEL) was used to detect deoxyribonucleic acid (DNA) fragmentation. TUNEL-positive cells were quantified. Caspase-3 activation was measured by Western blotting and immunohistochemistry. Double labeling was used to compare TUNEL with caspase-3 distribution and to identify the cell types affected. TUNEL-positive cells were also quantified at 6 hours, 1 day, and 3 days after injection of 5 U of thrombin into the right basal ganglion.

Results: At 6 hours, TUNEL-positive cells appeared in the ICH model (but not in the saline control brains) and were present for more than 2 weeks after ICH, peaking at 3 days. Western blot analysis revealed that the increase in immunoreactivity for the activated caspase-3 precedes that of DNA fragmentation, peaking at 1 day after ICH and declining thereafter. Immunohistochemistry analysis showed nucleus translocation of caspase-3 after ICH. Double-labeling studies demonstrated that both neurons and astrocytes surrounding the clot were TUNEL-positive. In addition, TUNEL and caspase-3 were colocalized in the same cells. Intracerebral thrombin injection elicited DNA fragmentation similar to that observed after the injection of blood.

Conclusion: Double-strand breaks in genomic DNA and induction of caspase-3 were demonstrated adjacent to parenchymal hematoma in the animals' brains. These results provide evidence that cell loss after ICH is associated with activation of caspase-3.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Basal Ganglia / pathology
  • Basal Ganglia Hemorrhage / pathology
  • Brain / pathology
  • Caspase 3
  • Caspases / metabolism
  • Cell Death / physiology*
  • Cerebral Hemorrhage / pathology*
  • DNA Damage
  • Enzyme Activation
  • In Situ Nick-End Labeling
  • Male
  • Rats
  • Rats, Sprague-Dawley
  • Thrombin / toxicity

Substances

  • Thrombin
  • Casp3 protein, rat
  • Caspase 3
  • Caspases