argpyrimidine and Schizophrenia

Argpyrimidine (ARP) is an advanced glycation end product thought to be generated from a reaction between methylglyoxal and arginine residues in proteins. In this study, we observed marked accumulation of an approximately 56 kD protein, reactive to anti-ARP antibodies, in the red blood cells (RBCs) of some patients with refractory schizophrenia. This ARP-modified protein was purified from the blood of schizophrenic patients and identified as selenium binding protein 1 (SBP1) by LC-MS/MS. This is the first report of ARP-modified proteins accumulating in RBCs of patients with diseases involving carbonyl stress. We also observed high accumulation of ARP-modified SBP1 in the RBCs of patients with chronic kidney disease. Therefore, this modified protein may be a novel marker of carbonyl stress.

Topics: Biomarkers; Erythrocytes; Female; Humans; Japan; Male; Ornithine; Prevalence; Protein Carbonylation; Pyrimidines; Reproducibility of Results; Risk Assessment; Schizophrenia; Selenium-Binding Proteins; Sensitivity and Specificity

Although it's well known that protein carbonyl (PCO) and advanced glycation end-products (AGEs) levels are elevated in plasma from patients with renal dysfunction, we recently identified patients who had no renal dysfunction but possessed high levels of plasma pentosidine (PEN), which is an AGEs, and low vitamin B6 levels in serum. In this study, we investigated the status of carbonyl stress to characterize the subtype of schizophrenia. When plasma samples were subjected to Western blot analysis for various AGEs, clear differences were only observed with the anti-PEN antibody in the plasma from schizophrenic patients. Moreover, we determined the formation of protein carbonyl (PCO), a typical indicator of carbonyl stress, occurred prior to the accumulation of PEN in the plasma of schizophrenic patients. PCO levels in the plasma from schizophrenic patients were significantly higher than that from healthy subjects. Western blots analysis clearly showed that albumin and IgG were markedly carbonylated in the plasma of some patients. Thus, PCOs may be a novel marker of carbonyl stress-type schizophrenia in addition to albumin containing PEN structure.

Topics: Adult; Antibodies, Monoclonal; Arginine; Biomarkers; Blood Proteins; Case-Control Studies; Female; Glycation End Products, Advanced; Humans; Immunoglobulin G; Lysine; Male; Middle Aged; Ornithine; Protein Carbonylation; Pyrimidines; Schizophrenia; Serum Albumin; Vitamin B 6; Vitamin B 6 Deficiency