Quantification of Modified Tyrosines in Healthy and Diabetic Human Urine using Liquid Chromatography/Tandem Mass Spectrometry

Kato, Yoji; Dozaki, Natsuko; Nakamura, Toshiyuki; Kitamoto, Noritoshi; Yoshida, Akihiro; Naito, Michitaka; Kitamura, Masayasu; Osawa, Toshihiko

doi:10.3164/jcbn.08-185

Cited by 53 publications

(67 citation statements)

References 64 publications

(74 reference statements)

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“…The levels of the measured concentrations of the markers correspond to ranges identified in previously published data, which were measured on the different groups of healthy, non-pregnant subjects (11,12,16,25,26). The concentrations of the markers vary between studies.…”

Section: Discussionmentioning

confidence: 99%

“…The concentrations of the markers vary between studies. These studies in healthy non-pregnant women reported that the urinary HEL levels were between 1.58±0.23 and 2.3±1.2 µmol/mol Cr (11,12,16), PRL levels were 21.6±10.6 µmol/mol Cr (11), DiY levels were between 8.8±0.6 and 10.1±0.4 µmol/mol Cr (16,25) and NY levels were between 0.46±0.49 and 1.4±0.4 µmol/mol Cr (16,26).…”

Section: Discussionmentioning

confidence: 99%

“…LC-MS/MS analysis was conducted using an API-3000 electrospray ionisation/quadrupole tandem mass spectrometer (Applied Biosystems; Thermo Fisher Scientific, Inc., Foster City, CA, USA). HEL, PRL and NY were not detectable in their intact form and were therefore butylated (n-butanol/HCl) prior to the analysis, as previously described (11,16). Chromatography was performed using a Develosil C30-UG-5 (2x150 mm) column for HEL and PRL, an ODS-HG-3 (2x50 mm) column for DiY and an ODS-SR-5 (2x150 mm) for NY (all columns from Nomura Chemical Co., Seto, Japan), using an Agilent 1100 high-performance liquid chromatography system (Agilent Technologies, Inc., Santa Clara, CA, USA).…”

Section: Methodsmentioning

confidence: 99%

“…Prior to the analysis, urine samples were defrosted and centrifuged at 877 x g for 10 min at 4˚C to remove all insoluble particles, and the supernatant was collected. The concentration of urinary PRL, HEL, NY and DiY was measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS), using a multiple reaction monitoring technique with stable-isotope dilution, as previously described (11,16). LC-MS/MS analysis was conducted using an API-3000 electrospray ionisation/quadrupole tandem mass spectrometer (Applied Biosystems; Thermo Fisher Scientific, Inc., Foster City, CA, USA).…”

Section: Methodsmentioning

confidence: 99%

“…The nitration of tyrosine in proteins by peroxynitrite, which is a strong oxidising agent generated during the reaction of nitric oxide and the superoxide anion, generates 3-nitrotyrosine (NY). NY is a promising biomarker for protein tyrosine nitration in vivo, and elevated levels of NY have been detected in the urine of diabetic patients (16). An additional stable and potential marker of protein oxidation is dityrosine (DiY), the formation of which is initiated with a tyrosyl radical and concludes with the intermolecular cross-linkage of two tyrosine-containing proteins (17,18).…”

Section: Introductionmentioning

confidence: 99%

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Lipid-lysine adducts and modified tyrosines as markers of oxidative stress in the second trimester of pregnancy and their association with infant characteristics

Rejc

Kato

Karas-Kuzelicki

et al. 2016

Experimental and Therapeutic Medicine

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Abstract. Pregnancy is a physiological state accompanied by excessive levels of oxidative stress (OS), due to the increased demand and utilisation of oxygen. There is increasing evidence that maternally augmented OS exerts an adverse effect on pregnancy outcome. The aim of the present prospective study was to determine the association between the urinary concentration of relatively novel OS markers measured in the second trimester of pregnancy and the infant characteristics at birth. The maternal levels of urinary hexanoyl-lysine (HEL), propanoyl-lysine (PRL), dityrosine (DiY) and 3-nitrotyrosine (NY) were evaluated in generally healthy pregnant subjects to determine their association with birth weight, gestation at delivery and Apgar score. The observed levels of the markers were in agreement with those measured in healthy non-pregnant subjects in a previous study. A positive correlation was detected between HEL and PRL, as well as between HEL and DiY. Although the absence of a correlation between NY and the other markers has been previously noted in a non-pregnant population, a positive correlation in the pair PRL-NY (r=0.367; P<0.001) was observed in the present study. Maternal cigarette smoking was associated with increased urinary PRL levels (P=0.034). The most notable observation in the present study was that high levels of PRL and NY were associated with low Apgar scores at 1 and 5 min after birth (OR, 1.098 and 2.084 for PRL and NY, respectively; P<0.05). However, poor predictive accuracy was shown. For NY, the following results were obtained: Area under the curve (AUC), 0.818; sensitivity, 100%; specificity, 57%; positive predictive value (PPV), 11.54%; and negative predictive value (NPV), 100%.For PLR the values were as follows: AUC, 0.802; sensitivity, 100%; specificity, 62.6%; PPV, 13.05%; and NPV, 100%. DiY was negatively associated with preterm birth risk (OR=0.703; P=0.028). In conclusion, the results of the present study indicated the presence of OS in the second trimester of pregnancy, which was detected with damage to lipids and proteins and associated with an adverse Apgar score; however, the selected urinary markers exhibited poor positive predictive efficacy.

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