The urinary organic acids profile in single large-scale mitochondrial DNA deletion disorders.

Single large-scale mitochondrial DNA deletions disorders are classified into three main phenotypes with frequent clinical overlap: Pearson marrow-pancreas syndrome (PMS), Kearns-Sayre syndrome (KSS) and chronic progressive external ophtalmoplegia (PEO). So far, only few anecdotal studies have reported on the urinary organic acids profile in this disease class. In this single-center retrospective study, we performed quantitative evaluation of urinary organic acids in a series of 15 pediatric patients, 7 with PMS and 8 with KSS. PMS patients showed an organic acids profile almost constantly altered, whereas KSS patients frequently presented with normal profiles. Lactate, 3-hydroxybutyrate, 3-hydroxyisobutyrate, fumarate, pyruvate, 2-hydroxybutyrate, 2-ethyl-3-hydroxypropionate, and 3-methylglutaconate represented the most frequent metabolites observed in PMS urine. We also found novel metabolites, 3-methylglutarate, tiglylglycine and 2-methyl-2,3-dihydroxybutyrate, so far never reported in this disease. Interestingly, patients with a disease onset as PMS evolving overtime into KSS phenotype, presented persistent and more pronounced alterations of organic acid signature than in patients with a pure KSS phenotype. Our study shows that the quantitative analysis of urinary organic acid profile represents a helpful tool for the diagnosis of PMS and for the differential diagnosis with other inherited diseases causing abnormal organic acidurias.

Preliminary Study on J-Resolved NMR Method Usability for Toxic Kidney's Injury Assessment.

BACKGROUND: Nowadays, the Nuclear Magnetic Resonance (NMR) techniques are tested for metabolomic urine profile in order to detect early damage of kidney. OBJECTIVES: The purpose of this investigation was the initial assessment of two-dimensional J-resolved NMR urine spectra analysis usability for early kidney injuries detection. The amino acids (AA) and acids profile change after the exposure to nephrotoxic agent (the cisplatin infusion) was examined. MATERIAL AND METHODS: The material was the urine of patients with non-small-cell lung cancer, treated with cisplatin in Pulmonology and Lung Cancers Clinic in Wroclaw. The urine of healthy volunteers was also examined. The identification of metabolites in urine was based on two-dimensional JRES signals in spectra, described in Human Metabolites Database (HMD). The molar concentration of metabolites was calculated from the volume under the signals. The analysis was focused on amino acids and organic acids (lactid acid and pyruvic acid) profiles. RESULTS: Any specific amino acids were identified after cisplatin infusion in comparison to the state before infusion. However, the differences in concentration were observed over 2-fold increase in valine, isoleucine and leucine, over 3-fold in alanine. Also, the concentration of pyruvic and lactic acids increased significantly (p≤0.05, p≤0.01). CONCLUSIONS: There were no specific amino acids identified in response to the infusion of cisplatin; however, some changes in the concentrations of amino acids and other small molecules were found. The analysis of two-dimensional JRES spectra showed an increase of alanine, leucine, isoleucine and valine concentration after the application of cisplatin. It seems that it is worth developing the JRES method based on special computer program.

Determination of α-ketoglutaric and pyruvic acids in urine as potential biomarkers for diabetic II and liver cancer.

BACKGROUND: A simple and sensitive hollow fiber-liquid phase microextraction with in situ derivatization method was developed for the determination of α-ketoglutaric (α-KG) and pyruvic acids (PA) in small-volume urine samples. 2,4,6-trichloro phenyl hydrazine was used as derivatization agent. RESULTS: Under the optimum extraction conditions, enrichment factors of 742 and 400 for α-KG and PA, respectively, were achieved. Calibration curves were linear over the range 1 to 1000 ng/ml (r(2) ≥ 0.998). Detection and quantitation limits were 0.03 and 0.02, and 0.10 and 0.05 ng/ml for α-KG and PA, respectively. CONCLUSION: The concentrations in diabetic II and liver cancer samples were significantly lower than those from healthy people, showing their potential as biomarkers for these diseases.

Detection of urinary metabolomics before and after Pringle maneuver-induced liver ischemia and reperfusion injury in rats using gas chromatography-mass spectrometry.

BACKGROUND: Metabolomics studies can quantitatively detect the dynamic metabolic response of living systems. OBJECTIVE: To detect urinary metabolomics after hepatic ischemia/reperfusion (I/R) injury induced by the Pringle maneuver using gas chromatography-mass spectrometry (GC-MS). METHODS: Male Sprague-Dawley rats (N = 80) were randomly divided into 4 groups (n = 20/group): sham operation, day 1, day 3, and day 5. Rats in the day 1, day 3, and day 5 groups underwent the Pringle maneuver. Serum alanine transaminase (ALT) and total bilirubin (TBIL) were measured, and hematoxylin and eosin (HE) staining of the liver tissue was performed. GC-MS was used to detect urinary metabolomics. RESULTS: Compared with the sham group, the serum ALT and TBIL levels at day 1 were significantly elevated (P < 0.01) and then decreased and reached close to normal levels at day 5. GC-MS detected 7 metabolites which had similar changes as those of liver tissue revealed by histological examination. Significant differences in lactic acid, pyruvic acid, alanine, serine, and glycerol-3-phosphate were found among the groups (P < 0.001). Principle component analysis showed that 7 metabolites distinguished the day 1 and day 3 groups from the sham group. CONCLUSIONS: Noninvasive urinary metabolomic analysis is a potential means for the early detection and diagnosis of hepatic I/R injury.

1H-nuclear magnetic resonance spectroscopy-based metabolic assessment in a rat model of obesity induced by a high-fat diet.

Obesity, whose prevalence is increasing rapidly worldwide, is recognized as a risk factor for diabetes, cardiovascular disease, liver disease, and renal disease. To investigate metabolic changes in the urine of a rat model of obesity induced by a high-fat diet (HFD), rats were divided into the following four groups based on the diet type and degree of weight gain: normal-diet (ND) low gainers, ND high gainers, HFD low gainers, and HFD high gainers. Biochemical analyses of visceral fat-pad weight, plasma, and liver tissues were performed. The (1)H-nuclear magnetic resonance ((1)H-NMR) spectra of urine were analyzed using multivariate statistical analysis to identify the separation of the groups. It was observed that the metabolic profile of urine obtained by (1)H-NMR-spectroscopy-based metabolomic analysis differed between ND low gainers and ND high gainers even though these animals consumed the same normal diet. Several key metabolites in urine, such as betaine, taurine, acetone/acetoacetate, phenylacetylglycine, pyruvate, lactate, and citrate contributed to the classification of these two groups. The metabolic profile of urine also differed between ND low gainers and HFD high gainers, which consumed the different diet and showed a different weight gain. This study has identified features of urine metabolites in various groups and demonstrated the reliability of an NMR-based metabolomics approach to investigate the effects of the diet and the physical constitution on obesity.