Loss of the ataxia-telangiectasia gene product causes oxidative damage in target organs.
Ataxia-telangiectasia (A-T) is characterized by a markedly increased sensitivity to ionizing radiation, increased incidence of cancer, and neurodegeneration, especially of the cerebellar Purkinje cells. Ionizing radiation oxidizes macromolecules and causes tissue damage through the generation of reactive oxygen species (ROS). We therefore hypothesized that A-T is due to oxidative damage resulting from loss of function of the A-T gene product. To assess this hypothesis, we employed an animal model of A-T, the mouse with a disrupted Atm gene. We show that organs which develop pathologic changes in the Atm-deficient mice are targets of oxidative damage, and that cerebellar Purkinje cells are particularly affected. These observations provide a mechanistic basis for the A-T phenotype and lay a rational foundation for therapeutic intervention.
Barlow
C
C
Laboratory of Genetic Disease Research, National Human Genome Research Institute, Bethesda, MD 20892, USA. barlow@salk.edu
Dennery
P A
PA
Shigenaga
M K
MK
Smith
M A
MA
Morrow
J D
JD
Roberts
L J
LJ
Wynshaw-Boris
A
A
Levine
R L
RL
D000818:Animals; D001260:Ataxia Telangiectasia / Q000473:pathology*; D064007:Ataxia Telangiectasia Mutated Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism; D051547:Heme Oxygenase-1; D007527:Isoenzymes / Q000378:metabolism; D050356:Lipid Metabolism; D008565:Membrane Proteins; D051379:Mice; D018345:Mice, Knockout; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D017346:Protein Serine-Threonine Kinases; D011506:Proteins / Q000378:metabolism / Q000502:physiology*; D011689:Purkinje Cells / Q000473:pathology; D025521:Tumor Suppressor Proteins
D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D007527:Isoenzymes; D008565:Membrane Proteins; D011506:Proteins; D025521:Tumor Suppressor Proteins; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; C496542:Hmox1 protein, mouse; C105245:heme oxygenase-2; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C576325:Atm protein, mouse; D017346:Protein Serine-Threonine Kinases