Nitrotyrosine in plasma of celiac disease patients as detected by a new sandwich ELISA

Steege, J. C. A. Ter; Koster-Kamphuis, Linda; Straaten, E. A. Van; Forget, Patricia; Buurman, W.A.

doi:10.1016/s0891-5849(98)00184-1

Cited by 128 publications

(92 citation statements)

References 36 publications

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“…By contrast, Frost et al 4 have measured by GC/MS a NO 2 Tyr concentration of 64 nmol/L and a mean 3-nitrotyrosine:tyrosine ratio of Ϸ35ϫ1:10 6 in plasma of healthy humans. These values are 23 and 35 times higher than those measured by us, 9,10 respectively, and even 2 times higher than those found by Kamisaki et al 5 Immunohistochemical methods and ELISA 7,8 are frequently used to detect 3-nitrotyrosine. However, the highly divergent values reported for plasma 3-nitrotyrosine ranging between not detectable 7 and 120 nmol/L, 8 strongly suggest that these semiquantitative methods are suffering from serious methodological problems.…”

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confidence: 53%

Methodological Considerations on the Detection of 3-Nitrotyrosine in the Cardiovascular System

Tsikas

Schwedhelm

Frölich

2002

Circulation Research

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Reactive nitrogen species (RNS; eg, • NO,• NO 2 , ONOO Ϫ , NO 2 Cl) react preferably with tyrosine (Tyr) and protein-associated tyrosine (TyrProt) to form 3-nitrotyrosine, ie NO 2 Tyr and NO 2 TyrProt, respectively. 1 Therefore, detection of NO 2 Tyr and/or NO 2 TyrProt provides evidence for generation of RNS rather than specifically peroxynitrite (ONOO Ϫ ). 1 Besides this difficulty, Tarpey and Fridovich 2 have recently discussed, in an article published in Circulation Research, the problematic measurement of NO 2 Tyr and NO 2 TyrProt, giving special attention to artifactual formation of NO 2 Tyr and NO 2 TyrProt by acidification of biological samples. This methodological pitfall is very important and well-recognized, 3-10 but it is not the sole methodological problem in 3-nitrotyrosine detection. Tarpey and Fridovich 2 restricted their discussion exclusively to artifactual formation of 3-nitrotyrosine referring to Yi et al 3 and Frost et al,4 whose methods, however, are either not sufficiently sensitive to detect basal NO 2 Tyr plasma levels 3 or yield overestimated values for NO 2 Tyr and NO 2 TyrProt. 4 The discussion on this subject is incomplete and leaves out other serious problems and solutions. We would like to discuss critically these issues and to evaluate the most relevant techniques 3-10 that are presently available to determine levels of NO 2 Tyr and NO 2 TyrProt, which include MS-based methods, ie LC/MS/MS, 3 GC/MS, 4 and GC/MS/MS, 9,10 HPLC, 5,6 and ELISA. 7,8 Acidification. Acidification of Tyr-and TyrProt-containing biological samples convincingly and inevitably results in the artifactual formation of NO 2 Tyr and NO 2 TyrProt. 2-9 Avoidance of acidic conditions prevents artifactual formation of 3-nitrotyrosine. [3][4][5][6]9 Regarding NO 2 TyrProt, this means that plasma proteins must be hydrolyzed enzymatically under nonacidic conditions. 6,10 Especially in MS-based methods, in which artifactual formation of NO 2 Tyr from the necessary derivatization may occur, 3,4,9 separation of NO 2 Tyr from Tyr is absolutely required and can be easily achieved by HPLC. 9 Protein denaturation. When measuring plasma NO 2 Tyr, its release from denaturing NO 2 TyrProt must be avoided by gentle blood drawing, immediate generation of plasma and plasma ultrafiltrate under mild nonacidic conditions (eg, 2°C to 4°C), 9,10 and immediate analysis of the plasma ultrafiltrate. Plasma samples stored at Ϫ80°C should be thawed once only. 9 Interferences in GC/MS. Unlike GC/MS/MS, we 9 have convincingly demonstrated that GC/MS does not possess the necessary specificity to selectively measure plasma NO 2 Tyr and have identified coeluting, NO 2 Tyr-unrelated interfering compounds as a further source for overestimated levels of NO 2 Tyr. Insufficient specificity of GC/MS was confirmed by measuring NO 2 Tyr in 12 older subjects (51Ϯ10 years) whose mean plasma NO 2 Tyr was determined to be 4.5 nmol/L by GC/MS, but only 1.2 nmol/L by GC/MS/MS.Basal plasma levels of NO2Tyr and NO2TyrProt. By means of GC/MS/MS (limit of quantitat...

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confidence: 53%

Methodological Considerations on the Detection of 3-Nitrotyrosine in the Cardiovascular System

Tsikas

Schwedhelm

Frölich

2002

Circulation Research

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“…Most studies of tyrosine nitration [118] rely on immunological detection thanks to commercially available antinitrotyrosine mAb, whether in the ELISA format [119], in which case it is difficult to distinguish between free circulating 3-nitrotyrosine and protein-bound nitrotyrosine, or in Western blot format after 1-D or 2-DE [120][121][122]. Immunoprecipitation with antinitrotyrosine antibodies allowed Nikov et al [123] to map nitration sites of HSA by MS.…”

Section: Nitrotyrosinementioning

confidence: 99%

Oxidation of proteins: Basic principles and perspectives for blood proteomics

Barelli

Canellini

Thadikkaran

et al. 2008

Proteomics Clinical Apps

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Protein oxidation mechanisms result in a wide array of modifications, from backbone cleavage or protein crosslinking to more subtle modifications such as side chain oxidations. Protein oxidation occurs as part of normal regulatory processes, as a defence mechanism against oxidative stress, or as a deleterious processes when antioxidant defences are overcome. Because blood is continually exposed to reactive oxygen and nitrogen species, blood proteomics should inherently adopt redox proteomic strategies. In this review, we recall the biochemical basis of protein oxidation, review the proteomic methodologies applied to analyse redox modifications, and highlight some physiological and in vitro responses to oxidative stress of various blood components.

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“…NT measurement NT plasma concentration was assayed by enzyme-linked immunosorbent assay (ELISA), developed according to Ter Steege et al (17) and recently validated by our laboratory (12 (18). After adjusting the pH to 10 with 3 mol/l NaOH, the amount of NT present in the TNM-treated BSA solution was measured at 430 nm (18).…”

Section: Biochemical Measurementsmentioning

confidence: 99%

Role of Hyperglycemia in Nitrotyrosine Postprandial Generation

et al. 2002

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OBJECTIVE -Recently, much attention has been paid to the possibility that postprandial hyperglycemia may be a cardiovascular risk factor in diabetes. Oxidative stress has been involved in the pathogenesis of diabetic complications, and increased plasma levels of nitrotyrosine, a product of peroxynitrite action, have been found in the plasma of diabetic subjects. The aim of the present study was to evaluate whether postprandial hyperglycemia is accompanied by nitrotyrosine generation and, if so, to explore a possible direct role of hyperglycemia in such a phenomenon. RESEARCH DESIGN AND METHODS-A total of 23 type 2 diabetic patients and 15 matched normal healthy subjects were recruited for this study. Two different tests were performed in diabetic patients: a standard meal preceded by regular insulin (0.15 units/kg body wt) or insulin aspart (0.15 units/kg body wt) to achieve different levels of postprandial hyperglycemia. The meal test was also performed in healthy control subjects. At 0 min and 1, 2, 4, and 6 h after each meal, blood glucose, triglyceride, and nitrotyrosine levels were measured.RESULTS -Fasting nitrotyrosine was significantly increased in diabetic patients and was further increased during both meal tests in diabetic subjects but not normal subjects. As compared with regular insulin, aspart administration significantly reduced the area under the curve of both glycemia (P Ͻ 0.04) and nitrotyrosine (P Ͻ 0.03), whereas that of triglycerides was not significantly affected by the treatment.CONCLUSIONS -This study shows a direct correlation between postprandial hyperglycemia and the production of nitrotyrosine, a marker of oxidative stress, in patients with type 2 diabetes.

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Nitrotyrosine in plasma of celiac disease patients as detected by a new sandwich ELISA

Cited by 128 publications

References 36 publications

Methodological Considerations on the Detection of 3-Nitrotyrosine in the Cardiovascular System

Methodological Considerations on the Detection of 3-Nitrotyrosine in the Cardiovascular System

Oxidation of proteins: Basic principles and perspectives for blood proteomics

Role of Hyperglycemia in Nitrotyrosine Postprandial Generation

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