TY - JOUR
T1 - Nitration of the Striatal Na,K-ATPase α3 Isoform Occurs in Normal Brain Development but Is Not Increased during Hypoxia-Ischemia in Newborn Piglets
AU - Golden, W. Christopher
AU - Brambrink, Ansgar M.
AU - Traystman, Richard J.
AU - Shaffner, Donald H.
AU - Martin, Lee J.
N1 - Funding Information:
The authors are grateful for the technical support of Mrs. Antionette Price and Mr. Frank Barksdale. This work was supported by grants from the National Institutes of Health, NS 34100 (L. J. M.) and NS 20020 (R. J. T.), and the Department of Defense, U.S. Army Medical Research and Materiel Command Contract DAMD17-99-1-9553 (L. J. M.).
PY - 2003/12
Y1 - 2003/12
N2 - Neonatal hypoxia-ischemia (HI) can result in significant sensorimotor abnormalities, including movement and posture disorders. These neurological impairments are believed to result from basal ganglia (striatum) damage, but the exact cause of this injury is not known. One mechanism involved in brain injury after HI is the generation of reactive oxygen species, which damage cellular macromolecules. We tested the hypothesis that inactivation of plasma membrane enzyme Na,K-ATPase during striatal neurodegeneration after HI emerges with peroxynitrite attack on the enzyme. In vitro, reaction of peroxynitrite (100-500 μM) with purified Na,K-ATPase produced nitration of the α (catalytic) and β (transport) subunits, as quantified by immunoblots of the reaction products for nitrotyrosine. To evaluate for peroxynitrite damage to Na,K-ATPase in vivo, striatal plasma membrane fractions from 1-week-old piglets subjected to asphyxic cardiac arrest and recovery were also studied by immunoprecipitation. During the progression of striatal neurodegeneration and loss of enzyme function 3-24 h after arrest, nitration of the α 3 (neuronal) isoform of Na,K-ATPase was not increased relative to sham control. Suprisingly, however, nitration of this α isoform occurs during normal brain development and peaks at 2 weeks of age. We conclude that Na,K-ATPase is a target of peroxynitrite, but that this mechanism is not responsible for enzyme inactivation after HI. Protein nitration may serve as marker of other normal, noninjurious cell processes in the developing brain.
AB - Neonatal hypoxia-ischemia (HI) can result in significant sensorimotor abnormalities, including movement and posture disorders. These neurological impairments are believed to result from basal ganglia (striatum) damage, but the exact cause of this injury is not known. One mechanism involved in brain injury after HI is the generation of reactive oxygen species, which damage cellular macromolecules. We tested the hypothesis that inactivation of plasma membrane enzyme Na,K-ATPase during striatal neurodegeneration after HI emerges with peroxynitrite attack on the enzyme. In vitro, reaction of peroxynitrite (100-500 μM) with purified Na,K-ATPase produced nitration of the α (catalytic) and β (transport) subunits, as quantified by immunoblots of the reaction products for nitrotyrosine. To evaluate for peroxynitrite damage to Na,K-ATPase in vivo, striatal plasma membrane fractions from 1-week-old piglets subjected to asphyxic cardiac arrest and recovery were also studied by immunoprecipitation. During the progression of striatal neurodegeneration and loss of enzyme function 3-24 h after arrest, nitration of the α 3 (neuronal) isoform of Na,K-ATPase was not increased relative to sham control. Suprisingly, however, nitration of this α isoform occurs during normal brain development and peaks at 2 weeks of age. We conclude that Na,K-ATPase is a target of peroxynitrite, but that this mechanism is not responsible for enzyme inactivation after HI. Protein nitration may serve as marker of other normal, noninjurious cell processes in the developing brain.
KW - Cell death
KW - Newborn brain damage
KW - Protein nitration
KW - Reactive oxygen species
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U2 - 10.1023/A:1026132110850
DO - 10.1023/A:1026132110850
M3 - Article
C2 - 14649731
AN - SCOPUS:0344392780
SN - 0364-3190
VL - 28
SP - 1883
EP - 1889
JO - Neurochemical Research
JF - Neurochemical Research
IS - 12
ER -