Targeted Antioxidant, Catalase-SKL, Reduces Beta-Amyloid Toxicity in the Rat Brain

Brain Pathol. 2017 Jan;27(1):86-94. doi: 10.1111/bpa.12368. Epub 2016 Jun 13.

Abstract

Accumulation of beta-amyloid (Aβ) in the brain has been implicated as a major contributor to the cellular pathology and cognitive impairment observed in Alzheimer's disease. Beta-amyloid may exert its toxic effects by increasing reactive oxygen species and neuroinflammation in the brain. This study set out to investigate whether a genetically engineered derivative of the peroxisomal antioxidant enzyme catalase (CAT-SKL), is able to reduce the toxicity induced by intracerebroventricular injection of Aβ25-35 in the mature rat brain. Histopathological and immunohistochemical analyses were used to evaluate neuroinflammation, and neuronal loss. Spatial learning and reference memory was assessed using the Morris water maze. CAT-SKL treatment was able to reduce the pathology induced by Aβ25-35 toxicity by significantly decreasing microglia activation in the basal forebrain and thalamus, and reducing cholinergic loss in the basal forebrain. Aβ25-35 animals showed deficits in long-term reference memory in the Morris water maze, while Aβ25-35 animals treated with CAT-SKL did not demonstrate long-term memory impairments. This preclinical data provides support for the use of CAT-SKL in reducing neuroinflammation and long-term reference memory deficits induced by Aβ25-35.

Keywords: beta amyloid; catalase; neuroinflammation; oxidative stress.

MeSH terms

  • Amyloid beta-Peptides / toxicity*
  • Animals
  • Antioxidants / therapeutic use*
  • Brain / enzymology
  • Catalase / analysis
  • Cell Death
  • Drug Evaluation, Preclinical
  • Learning Disabilities / drug therapy
  • Learning Disabilities / prevention & control
  • Male
  • Maze Learning
  • Memory Disorders / drug therapy
  • Memory Disorders / prevention & control
  • Microglia / drug effects
  • Microglia / physiology
  • Nerve Tissue Proteins / analysis
  • Neurons / drug effects
  • Neurons / pathology
  • Neuroprotective Agents / therapeutic use*
  • Peptide Fragments / toxicity*
  • Prosencephalon / chemistry
  • Prosencephalon / drug effects
  • Prosencephalon / pathology
  • Random Allocation
  • Rats
  • Rats, Wistar
  • Spatial Learning / drug effects
  • Thalamus / chemistry
  • Thalamus / drug effects
  • Thalamus / pathology

Substances

  • Amyloid beta-Peptides
  • Antioxidants
  • Nerve Tissue Proteins
  • Neuroprotective Agents
  • Peptide Fragments
  • amyloid beta-protein (25-35)
  • Catalase
  • catalase-SKL, rat

Grants and funding