scholarly journals Reading patterns of proteome damage by glycation, oxidation and nitration: quantitation by stable isotopic dilution analysis LC-MS/MS

2020 ◽  
Vol 64 (1) ◽  
pp. 169-183 ◽  
Author(s):  
Naila Rabbani ◽  
Paul J. Thornalley

Abstract Liquid chromatography-tandem mass spectrometry (LC-MS/MS) provides a high sensitivity, high specificity multiplexed method for concurrent detection of adducts formed by protein glycation, oxidation and nitration, also called AGEomics. Combined with stable isotopic dilution analysis, it provides for robust quantitation of protein glycation, oxidation and nitration adduct analytes. It is the reference method for such measurements. LC-MS/MS has been used to measure glycated, oxidized and nitrated amino acids – also called glycation, oxidation and nitration free adducts, with a concurrent quantitation of the amino acid metabolome in physiological fluids. Similar adduct residues in proteins may be quantitated with prior exhaustive enzymatic hydrolysis. It has also been applied to quantitation of other post-translation modifications, such as citrullination and formation of Nε-(γ-glutamyl)lysine crosslink by transglutaminases. Application to cellular and extracellular proteins gives estimates of the steady-state levels of protein modification by glycation, oxidation and nitration, and measurement of the accumulation of glycation, oxidation and nitration adducts in cell culture medium and urinary excretion gives an indication of flux of adduct formation. Measurement of glycation, oxidation and nitration free adducts in plasma and urine provides for estimates of renal clearance of free adducts. Diagnostic potential in clinical studies has been enhanced by the combination of estimates of multiple adducts in optimized diagnostic algorithms by machine learning. Recent applications have been in early-stage detection of metabolic, vascular and renal disease, and arthritis, metabolic control and risk of developing vascular complication in diabetes, and a blood test for autism.

Talanta ◽  
1963 ◽  
Vol 10 (4) ◽  
pp. 375-381 ◽  
Author(s):  
Jiří Starý ◽  
Jaromír Ru̇žička ◽  
Milan Salamon

2021 ◽  
Vol 11 ◽  
Author(s):  
Haiming Huang ◽  
Jialin Du ◽  
Bo Jin ◽  
Lu Pang ◽  
Nan Duan ◽  
...  

BackgroundThe recent discovery of miRNAs and lncRNAs in urine exosomes has emerged as promising diagnostic biomarkers for bladder cancer (BCa). However, mRNAs as the direct products of transcription has not been well evaluated in exosomes as biomarkers for BCa diagnosis. The purpose of this study was to identify tumor progression-related mRNAs and lncRNAs in urine exosomes that could be used for detection of BCa.MethodsRNA-sequencing was performed to identify tumor progression-related biomarkers in three matched superficial tumor and deep infiltrating tumor regions of muscle-invasive bladder cancer (MIBC) specimens, differently expressed mRNAs and lncRNAs were validated in TCGA dataset (n = 391) in the discovery stage. Then candidate RNAs were chosen for evaluation in urine exosomes of a training cohort (10 BCa and 10 healthy controls) and a validation cohort (80 BCa and 80 healthy controls) using RT-qPCR. The diagnostic potential of the candidates were evaluated by receiver operating characteristic (ROC) curves.ResultsRNA sequencing revealed 8 mRNAs and 32 lncRNAs that were significantly upregulated in deep infiltrating tumor region. After validation in TCGA database, 10 markedly dysregulated RNAs were selected for further investigation in urine exosomes, of which five (mRNAs: KLHDC7B, CASP14, and PRSS1; lncRNAs: MIR205HG and GAS5) were verified to be significantly dysregulated. The combination of the five RNAs had the highest AUC to disguising the BCa (0.924, 95% CI, 0.875–0.974) or early stage BCa patients (0.910, 95% CI, 0.850 to 0.971) from HCs. The expression levels of these five RNAs were correlated with tumor stage, grade, and hematuria degrees.ConclusionsThese findings highlight the potential of urine exosomal mRNAs and lncRNAs profiling in the early diagnosis and provide new insights into the molecular mechanisms involved in BCa.


1993 ◽  
Vol 84 (1) ◽  
pp. 87-93 ◽  
Author(s):  
Patricia R. Smith ◽  
Hanif H. Somani ◽  
Paul J. Thornalley ◽  
Jonathan Benn ◽  
Peter H. Sonksen

1. It has been suggested that 2-amino-6-(2-formyl-5-hydroxymethyl-pyrrol-l-yl)-hexanoic acid ('pyrraline') is formed as an advanced glycation end product in the Maillard reaction under physiological conditions. Antibodies were raised to caproyl-pyrraline linked to keyhole-limpet haemocyanin and were used to develop an e.l.i.s.a. and Western blotting system for the specific detection of pyrraline in samples in vivo and in vitro. 2. Human serum albumin was isolated from the serum samples of diabetic and non-diabetic subjects. Pyrraline was not detected (<1.2 pmol) in any of the samples, indicating that it was not a major advanced glycation end product in vivo. 3. BSA was incubated separately with D-glucose and a model fructosamine, N-(l-deoxy-D-fructos-l-yl)-hippuryl-lysine, under physiological conditions for 30 days. Aliquots removed from the incubations at 5 day intervals contained no detectable pyrraline, indicating that pyrraline was not an early-stage product of the Maillard reaction in vitro. 4. The model fructosamine, N>-(1-deoxy-D-fructos-l-yl)-hippuryl-lysine, was incubated at pH 7.4 and 37°C for 25 days during which it degraded to hippuryl-lysine and N>-carboxymethyl-hippuryl-lysine. Aliquots were removed at 5 day intervals and assayed for pyrraline. None was detected (<23 pmol/ml) in the course of the degradation of the fructosamine (400 nmol/ml degraded), indicating that pyrraline was not a major product of the degradation of fructosamine under physiological conditions in vitro. 5. We conclude that pyrraline is not a major intermediate or advanced glycation end product in the Maillard reaction under physiological conditions in vitro and in vivo. A previous report of immunoassay of pyrraline may have given positive results because of non-specific antibodies raised to impure hapten.


2016 ◽  
Vol 19 (4) ◽  
pp. 410-418 ◽  
Author(s):  
Sandra Felten ◽  
Kaspar Matiasek ◽  
Stefanie Gruendl ◽  
Laura Sangl ◽  
Gerhard Wess ◽  
...  

Objectives Feline coronaviruses (FCoVs) exist as two biotypes, feline enteric coronavirus and feline infectious peritonitis virus. Although feline infectious peritonitis (FIP) is a very common disease, the ante-mortem diagnosis of this disease still remains a challenge. Immunofluorescence staining of FCoV in macrophages in effusion has been considered as the reference standard for the diagnosis, but recently this method has been shown to have lower specificity than previously reported. In addition, this method is not widely available and requires the use of fluorescence microscopes. Therefore, it was the aim of this study to evaluate the diagnostic potential of an immunocytochemical (ICC) assay using body cavity effusion. Methods Effusion samples from 27 cats with immunohistochemically confirmed FIP and 29 cats with suspected FIP but a definitive diagnosis of another disease were examined. ICC specimens were evaluated with respect to positive immunostaining. In addition, effusion samples were stained with haematoxylin and eosin and evaluated cytologically. Results A diagnostic sensitivity of 85.2% was recorded for effusion specimens (95% confidence interval [CI] 66.3–95.8), while the diagnostic specificity was only 72.4% (95% CI 52.8–87.3). Conclusions and relevance Once the clinical disease of FIP develops in a cat, it always leads to death, and most of the cats are euthanased within a few days or weeks. As false-positive results might lead to euthanasia of cats suffering from potentially treatable diseases, the diagnostic specificity of a diagnostic tool is the most important factor in a fatal disease like FIP. Thus, the diagnostic utility of this test proved to be insufficient and positive ICC results should be interpreted with caution. Nevertheless, full-body necropsy could not be performed in 13/29 control cats. It is possible that these cats actually suffered from early-stage FIP and that this fact might have influenced the diagnostic specificity of the ICC. Based on the results of the present study, however, ICC of effusion samples currently cannot be recommended to confirm a suspicion of FIP.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Sahar Waris ◽  
Brigitte M. Winklhofer-Roob ◽  
Johannes M. Roob ◽  
Sebastian Fuchs ◽  
Harald Sourij ◽  
...  

Aim. The aim of this study was to assess the changes of markers of DNA damage by glycation and oxidation in patients with type 2 diabetes and the association with diabetic nephropathy.Methodology. DNA oxidation and glycation adducts were analysed in plasma and urine by stable isotopic dilution analysis liquid chromatography-tandem mass spectrometry. DNA markers analysed were as follows: the oxidation adduct 7,8-dihydro-8-oxo-2′-deoxyguanosine (8-OxodG) and glycation adducts of glyoxal and methylglyoxal—imidazopurinones GdG, MGdG, and N2-(1,R/S-carboxyethyl)deoxyguanosine (CEdG).Results. Plasma 8-OxodG and GdG were increased 2-fold and 6-fold, respectively, in patients with type 2 diabetes, with respect to healthy volunteers. Median urinary excretion rates of 8-OxodG, GdG, MGdG, and CEdG were increased 28-fold, 10-fold, 2-fold, and 2-fold, respectively, in patients with type 2 diabetes with respect to healthy controls. In patients with type 2 diabetes, nephropathy was associated with increased plasma 8-OxodG and increased urinary GdG and CEdG. In a multiple logistic regression model for diabetic nephropathy, diabetic nephropathy was linked to systolic blood pressure and urinary CEdG.Conclusion. DNA oxidative and glycation damage-derived nucleoside adducts are increased in plasma and urine of patients with type 2 diabetes and further increased in patients with diabetic nephropathy.


2021 ◽  
Vol 11 ◽  
Author(s):  
Vivek Kumar ◽  
Sameer Gupta ◽  
Amrita Chaurasia ◽  
Manisha Sachan

BackgroundEpithelial ovarian cancer (EOC) is one of the most lethal gynecological malignancies among women worldwide. Early diagnosis of EOC could help in ovarian cancer management. MicroRNAs, a class of small non-coding RNA molecules, are known to be involved in post-transcriptional regulation of ~60% of human genes. Aberrantly expressed miRNAs associated with disease progression are confined in lipid or lipoprotein and secreted as extracellular miRNA in body fluid such as plasma, serum, and urine. MiRNAs are stably present in the circulation and recently have gained an importance to serve as a minimally invasive biomarker for early detection of epithelial ovarian cancer.MethodsGenome-wide methylation pattern of six EOC and two normal ovarian tissue samples revealed differential methylation regions of miRNA gene promoter through MeDIP-NGS sequencing. Based on log2FC and p-value, three hypomethylated miRNAs (miR-205, miR-200c, and miR-141) known to have a potential role in ovarian cancer progression were selected for expression analysis through qRT-PCR. The expression of selected miRNAs was analyzed in 115 tissue (85 EOC, 30 normal) and 65 matched serum (51 EOC and 14 normal) samples.ResultsAll three miRNAs (miR-205, miR-200c, and miR-141) showed significantly higher expression in both tissue and serum cohorts when compared with normal controls (p &lt; 0.0001). The receiver operating characteristic curve analysis of miR-205, miR-200c, and miR-141 has area under the curve (AUC) values of 87.6 (p &lt; 0.0001), 78.2 (p &lt; 0.0001), and 86.0 (p &lt; 0.0001), respectively; in advance-stage serum samples, however, ROC has AUC values of 88.1 (p &lt; 0.0001), 78.9 (p &lt; 0.0001), and 86.7 (p &lt; 0.0001), respectively, in early-stage serum samples. The combined diagnostic potential of the three miRNAs in advance-stage serum samples and early-stage serum samples has AUC values of 95.9 (95% CI: 0.925–1.012; sensitivity = 96.6% and specificity = 80.0%) and 98.1 (95% CI: 0.941–1.021; sensitivity = 90.5% and specificity = 100%), respectively.ConclusionOur data correlate the epigenetic deregulation of the miRNA genes with their expression. In addition, the miRNA panel (miR-205 + miR-200c + miR-141) has a much higher AUC, sensitivity, and specificity to predict EOC at an early stage in both tissue and serum samples.


2020 ◽  
Vol 14 (2) ◽  
pp. 119-130
Author(s):  
Siqi Guo ◽  
Jing Kong ◽  
Danya Zhou ◽  
Minchao Lai ◽  
Yirun Chen ◽  
...  

Aim: We aimed to identify metabolic characteristics of early-stage heart failure (HF) and related biomarkers. Patients & methods: One hundred and forty-three patients with New York Heart Association class I–IV HF and 34 healthy controls were recruited. Serum metabolic characteristics of class I HF were analyzed and compared with those of class II–IV HF. Potential biomarkers of class I HF with normal N-terminal-pro-B-type natriuretic peptide (NT-proBNP) level were screened and validated in additional 72 subjects (46 class I patients and 26 controls). Results & conclusion: Eleven metabolites were found disturbed in class I HF, and five of which were also disturbed in class II–IV HF. Glutamine and tyrosine showed high value to identify class I HF with normal NT-proBNP level. The diagnostic potential of glutamine was partially confirmed in the validate set, holding a promise to detect early HF with normal NT-proBNP level.


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