Metabolomic identification of potential phospholipid biomarkers for chronic glomerulonephritis by using high performance liquid chromatography-mass spectrometry

Plasma phospholipids metabolic profile of chronic glomerulonephritis was investigated using high performance liquid chromatography/mass spectrometry (LC/MS) and principal component analysis. The plasma samples of 18 patients with chronic glomerulonephritis, 17 patients with chronic renal failure (CRF) without renal replacement therapy and 18 healthy persons were collected and analyzed. It was found that combination of the LC/MS technique with PCA can be successfully applied to phospholipid profile analysis. The results showed that primary chronic glomerulonephritis and CRF had phospholipids metabolic abnormality. Nineteen phospholipid species were identified as possible biomarkers in plasma samples of chronic glomerulonephritis and chronic renal failure. Moreover, the identification of the molecular structure of the potential phospholipid markers was obtained by ESI-MS/MS experiment. It suggests that phospholipids can be used as potential biomarkers on the progress of primary chronic glomerulonephritis.     

Changes in serological biomarkers of liver function and connective tissue turnover in chronic hepatitis B during lamivudine therapy

Abstract

Assessment of hepatic damage associated with chronic hepatitis B (CHB) currently relies on measurement of serum transaminases and assessment of hepatic histology. It was determined serum hepatic function tests and the liver fibrosis biomarkers type IV collagen (CIV), amino-terminal propeptide of type I procollagen (PINP), amino-terminal propeptide of type III procollagen (PIIINP) and carboxy-terminal telopeptide of type I collagen (ICTP) were of value in monitoring the effect of lamivudine therapy for CHB. Thirty-nine patients received orally 100?mg lamivudine daily for 48 weeks. Blood samples were obtained at baseline, 24 and 48 weeks. At the end of the treatment period, the patients were then divided into four groups according to the pattern of HBs and HBe antigens. At baseline, alanine aminotransferase, aspartate aminotransferase, PIIINP and the PINP/ICTP ratio and at 24 weeks alanine aminotransferase, aspartate aminotransferase and the PINP/ICTP ratio had lower values in the complete response compared with complete failure groups. Using receiver-operated curve analysis, only the PINP/ICTP ratio at baseline (area under the curve 0.806) and ALT and the PINP/ICTP ratio at 24?weeks (areas under the curve 0.803 and 0.776, respectively) had significant diagnostic ability in detecting responders. In conclusion, the PINP/ITCP ratio is sensitive and specific in detecting responders to treatment.     

Changes in serological biomarkers of liver function and connective tissue turnover in chronic hepatitis B during lamivudine therapy

Assessment of hepatic damage associated with chronic hepatitis B (CHB) currently relies on measurement of serum transaminases and assessment of hepatic histology. It was determined serum hepatic function tests and the liver fibrosis biomarkers type IV collagen (CIV), amino-terminal propeptide of type I procollagen (PINP), amino-terminal propeptide of type III procollagen (PIIINP) and carboxy-terminal telopeptide of type I collagen (ICTP) were of value in monitoring the effect of lamivudine therapy for CHB. Thirty-nine patients received orally 100 mg lamivudine daily for 48 weeks. Blood samples were obtained at baseline, 24 and 48 weeks. At the end of the treatment period, the patients were then divided into four groups according to the pattern of HBs and HBe antigens. At baseline, alanine aminotransferase, aspartate aminotransferase, PIIINP and the PINP/ICTP ratio and at 24 weeks alanine aminotransferase, aspartate aminotransferase and the PINP/ICTP ratio had lower values in the complete response compared with complete failure groups. Using receiver-operated curve analysis, only the PINP/ICTP ratio at baseline (area under the curve 0.806) and ALT and the PINP/ICTP ratio at 24 weeks (areas under the curve 0.803 and 0.776, respectively) had significant diagnostic ability in detecting responders. In conclusion, the PINP/ITCP ratio is sensitive and specific in detecting responders to treatment.     

Serum metabonomics study of chronic renal failure by ultra performance liquid chromatography coupled with Q-TOF mass spectrometry

A metabonomics technique based on ultra-performance liquid chromatography (UPLC) coupled with Q-TOF mass spectrometry was employed to investigate the sera from 32 patients with chronic renal failure (CRF) without renal replacement therapy and 30 healthy volunteers in order to find potential disease biomarkers and reveal its pathophysiological changes. After data acquisition Waters MarkerLynx software was used to report retention time and m/z pairs for each metabolite peak, these data were exported to an excel table, then handled by using multivariate analysis and the statistical analysis in the SIMCA-P and the SPSS softwares to obtain potential biomarkers which were further identified by MS/MS. Seven potential biomarkers, creatinine, tryptophan, phenylalanine, kynurenine and three lysophosphatidylcholines, were identified. The results suggest that CRF can lead to the increase of reservation of creatinine in the body, and the abnormal metabolism of the two essential amino acids and lysophosphatidylcholines. It has indicated that metabonomics will be a powerful tool in the clinic research.     

Serum metabonomics study of adenine-induced chronic renal failure in rats by ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry

An ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC Q-TOF MS) metabonomics approach was employed to study the serum metabolic profiling of adenine-induced chronic renal failure (CRF) rats. Acquired data were subjected to principal component analysis (PCA) for differentiating the CRF and the normal control groups. Potential biomarkers were screened by using S-plot and were identified by the accurate mass, isotopic pattern and MS/MS fragments information obtained from UPLC Q-TOF MS analysis. Significant differences in the serum level of creatinine, amino acids and LysoPCs were observed, indicating the perturbations of amino acid metabolism and phospholipid metabolism in adenine-induced CRF rats. This research proved that metabonomics is a promising tool for disease research.     

MSight: an image analysis software for liquid chromatography-mass spectrometry

Images obtained from high-throughput mass spectrometry (MS) contain information that remains hidden when looking at a single spectrum at a time. Image processing of liquid chromatography-MS datasets can be extremely useful for quality control, experimental monitoring and knowledge extraction. The importance of imaging in differential analysis of proteomic experiments has already been established through two-dimensional gels and can now be foreseen with MS images. We present MSight, a new software designed to construct and manipulate MS images, as well as to facilitate their analysis and comparison.     

Effect of a traditional Chinese medicine preparation Xindi soft capsule on rat model of acute blood stasis: a urinary metabonomics study based on liquid chromatography-mass spectrometry

Xindi soft capsule is a traditional Chinese medicine preparation which consists of sea buckthorn flavonoids and sea buckthorn berry oil. In this study, a urinary metabonomics method based on the ultra-performance liquid chromatography combined with quadrupole time-of-flight tandem mass spectrometry (UPLC Q-TOF MS) was used to evaluate the efficacy and study the mechanism of traditional Chinese medicine preparation to blood stasis. With pattern recognition analysis (principal component analysis and partial least squares-discriminate analysis) of urinary metabolites, a clear separation of acute blood stasis model group and healthy control group was achieved, the dose groups were located between acute blood stasis model group and healthy control group showing a tendency of recovering to healthy control group, high dose and middle dose were more effective than low dose. Some significantly changed metabolites like cholic acid, phenylalanine and kynurenic acid have been found and identified and used to explain the mechanism. The work shows that the metabonomics method is a valuable tool in the research mechanism of traditional Chinese medicine.     

Metabolic profiling by ultra-performance liquid chromatography-mass spectrometry and parallel factor analysis for the determination of disease biomarkers in Eucalyptus

In this article, we present and discuss an alternative for data analysis of the metabolic profiles of both healthy Eucalyptus globulus and those infected with the Mycosphaerella leaf disease. The crude extracts were analyzed by reversed-phase ultra performance liquid chromatography-mass spectrometry. In order to glean the most useful information from these complex measurements, parallel factor analysis (PARAFAC) was employed for pattern recognition. After PARAFAC modeling, inspection of the scores and loadings graph allowed distinction of the healthy from the infected E. globulus samples and determination of biomarkers related to the biotic stress. The assessment of the monoisotopic masses and the fragmentation patterns allowed the identification of these biomarkers. It is hoped that the proposed method can be used for the diagnosis of diseases in plants, as well as to provide additional insight into the plant’s defense mechanism. Potentially, this may demonstrate the advantages of employing high order chemometric techniques in metabolomic data analysis.     

Quantification of ACE inhibiting peptides in human plasma using high performance liquid chromatography-mass spectrometry

An HPLC-MRM-MS method was developed for the quantification of 17 small ACE inhibiting (ACEI) peptides in plasma samples collected from human volunteers after the consumption of a peptide-enriched drink. The assay shows the high selectivity and sensitivity necessary to monitor small changes in the levels of the ACEI peptides after consumption of drinks developed to effect lowering of the blood pressure. Four different sample preparation methods were tested and evaluated. The final sample preparation method selected is simple and effective and consists mainly of the removal of proteins by acidification and heating, followed by a large volume injection. Additional sample preparation steps such as solid phase extraction and liquid/liquid partitioning were studied. Although they resulted in cleaner extracts, losses of specific peptides such as SAP were frequently seen. The isotope labeled form of one of the peptides to be quantified, [U(13)C]IPP, was used as an internal standard. The limit of detection of the assay is below 0.01 ng ml(-1). The limit of quantification is between 0.05 and 0.2 ng ml(-1), which is approximately 10% of the expected peptide concentration in plasma based on a normal diet. The intra- and inter-day relative standard deviations for all peptides have shown to be below 25% and the method has an accuracy of better than 75%. The long-term stability is good. At least 200 samples could be analysed before the system had to be cleaned. The assay has been successfully applied to blood samples collected from volunteers during a human trial.