Cerebrospinal fluid, serum and plasma protein oxidation in Alzheimer's disease.
OBJECTIVE
Many studies have shown differences in carbonylation and nitration of individual proteins in brain and body fluids of Alzheimer's disease (AD) patients. Therefore, we wanted to examine whether total levels of these oxidative stress markers of proteins were altered in AD.


METHODS
Total levels of carbonyls and nitrotyrosine in cerebrospinal fluid, serum and plasma were measured in 22 AD patients and 18 age-matched controls using commercially available enzyme immunoassay kits.


RESULTS
Protein carbonylation in cerebrospinal fluid did not differ between AD patients and controls but was decreased in APOE epsilon4 carriers as compared with non-carriers. Serum but not plasma levels of carbonyls tended to be decreased in AD patients as compared with aged controls. Nitrotyrosine concentrations did not differ between the groups. Surrogate cerebrospinal fluid markers for AD, beta-amyloid (1-42) and tau, correlated with blood carbonyl and nitrotyrosine levels.


CONCLUSIONS
According to these preliminary data, changes in oxidative metabolism related to the pathogenesis of AD cannot be detected as increased cerebrospinal fluid, serum or plasma protein carbonylation or nitration.
Department of Neurology, Clinical Research Centre/Mediteknia, University of Kuopio and Kuopio University Hospital, Finland. minna.korolainen@uku.fi
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MA
Korolainen
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Pirttilä
D000544:Alzheimer Disease / Q000097:blood* / Q000134:cerebrospinal fluid*; D016564:Amyloid beta-Protein Precursor / Q000097:blood / Q000134:cerebrospinal fluid; D001798:Blood Proteins / Q000378:metabolism*; D002556:Cerebrospinal Fluid Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009603:Nitroso Compounds; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D050050:Protein Carbonylation; D012016:Reference Values; D014443:Tyrosine / Q000031:analogs & derivatives / Q000097:blood / Q000134:cerebrospinal fluid
D016564:Amyloid beta-Protein Precursor; D001798:Blood Proteins; D002556:Cerebrospinal Fluid Proteins; D009603:Nitroso Compounds; C002744:3-nitrotyrosine; D014443:Tyrosine