Rui-Chao Lin

Urinary metabonomics study on biochemical changes in an experimental model of chronic renal failure by adenine based on UPLC Q-TOF/MS

BACKGROUND Chronic renal failure (CRF) is a serious clinical symptom, occurring as the end result of all kinds of chronic kidney disease and its pathophysiological mechanism is not yet well understood. We investigated the metabolic profiling of urine samples from CRF model rats to find potential disease biomarkers and research pathology of CRF. METHODS An animal model of CRF was produced by adenine. Metabolic profiling of the urine was performed by using ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC Q-TOF/MS). 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(E) fragments information obtained from UPLC Q-TOF/MS analysis. RESULTS 12 metabolites in urine were identified as potential biomarkers. Adenine-induced CRF rats were characterized by the increase of phytosphingosine, adrenosterone, tryptophan, 2,8-dihydroxyadenine, creatinine, and dihydrosphingosine together with the decrease of N-acetylleucine, 3-O-methyldopa, ethyl-N2-acetyl-L-argininate, dopamine, phenylalanine and kynurenic acid in urine. The altered metabolites demonstrated perturbations of amino acids metabolism, phospholipids metabolism and creatinine metabolism in CRF rats. CONCLUSION This work shows that metabonomics method is a valuable tool in CRF mechanism study and assists in clinical diagnosis of CRF.

Intrarenal Metabolomic Investigation of Chronic Kidney Disease and its TGF-β1 Mechanism in Induced-adenine Rats using UPLC Q-TOF/HSMS/MSE

Chronic kidney disease (CKD) is becoming a worldwide public health problem. In this study, a kidney metabonomics method based on the ultra performance liquid chromatography/high-sensitivity mass spectrometry with MS(E) data collection technique was undertaken to explore the excretion pattern of low molecular mass metabolites in rat model of adenine-induced chronic renal failure (CRF). Coupled with blood biochemistry and kidney histopathology results, the significant difference in metabolic profiling between the adenine-induced CRF group and the control group by using pattern recognition analysis indicated that changes in global tissue metabolites were occurred. Some significantly changed metabolites like fatty acids, p-cresol sulfate, and indoxyl sulfate have been identified. The results showed that the most important CRF-related metabolites were polyunsaturated fatty acids, indoxyl sulfate, and p-cresyl sulfate. Indoxyl sulfate and p-cresyl sulfate (uremic toxins) were significantly increased in CRF rats. Indoxyl sulfate and p-cresyl sulfate stimulate progressive tubulointerstitial fibrosis by increasing the expression of transforming growth factor-β1 (TGF-β1). These biochemical changes in tissue metabolites are related to the perturbations of fatty acid metabolism and amino metabolism, which may be helpful to further understand the TGF-β1 mechanisms of tubulointerstitial fibrosis. This work shows that the metabonomics method is a valuable tool for studying the essence of CKD.

Ultra performance liquid chromatography-based metabonomic study of therapeutic effect of the surface layer of Poria cocos on adenine-induced chronic kidney disease provides new insight into anti-fibrosis mechanism.

The surface layer of Poria cocos (Fu-Ling-Pi, FLP) is commonly used in traditional Chinese medicine and its diuretic effect was confirmed in rat. Ultra performance liquid chromatography/quadrupole time-of-flight high-sensitivity mass spectrometry and a novel mass spectrometryElevated Energy data collection technique was employed to investigate metabonomic characteristics of chronic kidney disease (CKD) induced from adenine excess and the protective effects of FLP. Multiple metabolites are detected in the CKD and are correlated with progressive renal injury. Among these biomarkers, lysoPC(18∶0), tetracosahexaenoic acid, lysoPC(18∶2), creatinine, lysoPC (16∶0) and lysoPE(22∶0/0∶0) in the FLP-treated group were completely reversed to levels in the control group which lacked CKD. Combined with biochemistry and histopathology results, the changes in serum metabolites indicate that the perturbations of phospholipids metabolism, energy metabolism and amino acid metabolism are related to adenine-induced CKD and to the interventions of FLP on all the three metabolic pathways. FLP may regulate the metabolism of these biomarkers, especially their efficient utilization within the context of CKD. Furthermore, these biomarkers might serve as characteristics to explain the mechanisms of FLP.

Effect of ergosta-4,6,8(14),22-tetraen-3-one (ergone) on adenine-induced chronic renal failure rat: a serum metabonomic study based on ultra performance liquid chromatography/high-sensitivity mass spectrometry coupled with MassLynx i-FIT algorithm.

BACKGROUND Ergosta-4,6,8(14),22-tetraen-3-one (ergone) has been proven to prevent the progression of renal injury and the subsequent renal fibrosis. We investigated the therapeutic effects and mechanism of ergone on a chronic renal failure model of rats induced by adenine. METHODS A serum metabonomic method based on the UPLC Q-TOF/MS was undertaken to explore the excretion pattern of low molecular mass metabolites. RESULTS Coupled with blood biochemistry and kidney histopathology results, the significant difference in metabolic profiling between adenine-induced chronic renal failure group and the ergone treated group by using pattern recognition analysis indicated that changes in global serum metabolites occurred. Some significantly changed metabolites like lysophosphatidylcholines, adenine, dopamine, creatinine, aspartic acid and phenylalanine have been found and identified. These biochemical changes in serum metabolites are related to the perturbations of amino acid metabolism and lecithin metabolism, which may be helpful to further understand the chronic renal failure and therapeutic mechanisms of ergone. CONCLUSION The work shows that the metabonomic method is a valuable tool for studying the essence of chronic kidney disease and therapeutic effect mechanism of preclinical or clinical drug.

UPLC–MSE application in disease biomarker discovery: The discoveries in proteomics to metabolomics

In the last decade, proteomics and metabolomics have contributed substantially to our understanding of different diseases. Proteomics and metabolomics aims to comprehensively identify proteins and metabolites to gain insight into the cellular signaling pathways underlying disease and to discover novel biomarkers for screening, early detection and diagnosis, as well as for determining prognoses and predicting responses to specific treatments. For comprehensive analysis of cellular proteins and metabolites, analytical methods of wider dynamic range higher resolution and good sensitivity are required. Ultra performance liquid chromatography-mass spectrometry(Elevated Energy) (UPLC-MS(E)) is currently one of the most versatile techniques. UPLC-MS(E) is an established technology in proteomics studies and is now expanding into metabolite research. MS(E) was used for simultaneous acquisition of precursor ion information and fragment ion data at low and high collision energy in one analytical run, providing similar information to conventional MS(2). In this review, UPLC-MS(E) application in proteomics and metabolomics was highlighted to assess protein and metabolite changes in different diseases, including cancer, neuropsychiatric pharmacology studies from clinical trials and animal models. In addition, the future prospects for complete proteomics and metabolomics are discussed.

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.

Application of faecal metabonomics on an experimental model of tubulointerstitial fibrosis by ultra performance liquid chromatography/high-sensitivity mass spectrometry with MSE data collection technique

Chronic renal failure (CRF) is a major challenge for the public healthcare problem. A novel UPLC Q-TOF/MS method with MSE data collection mode was developed as a very effective biochemical analytical tool for precise identification of important biomarkers in the adenine-induced CRF rats. Nine endogenous metabolites were identified by using metabonomic method combined with multivariate data analysis, the accurate mass, isotopic pattern, MSE fragments information and MassLynx i-FIT algorithm. The identified metabolites indicated the perturbations of bile acid and phospholipid metabolism are related to CRF rats. This work shows that metabonomics method is a valuable tool in CRF mechanism study.

Ultra-performance liquid chromatography–mass spectrometry as a sensitive and powerful technology in lipidomic applications

Lipidomics, the comprehensive illumination of lipid-based information in biology systems, involves in identifying lipids and profiling lipids and lipid-derived mediators. The development of lipidomics enables the characterization of lipid species and detailed lipid profiling in body fluid, tissue or cell, and allows for a wider understanding of the biological roles of lipid networks. Lipidomic research has been greatly facilitated by recent advances in ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) and involved in lipid extraction, lipid identification and data analysis supporting applications from qualitative and quantitative assessment of multiple lipid species. UPLC technique, different mass spectrometry technique, lipid extraction and data analysis in lipidomics are reviewed. Afterwards, examples are provided on the use of UPLC-MS for finding lipid biomarkers in disease, drug, food, nutrition and plant fields. We also discuss the UPLC-MS-based lipidomics for the future perspectives and their potential problems.

UPLC-Q-TOF/HSMS/MSE-based metabonomics for adenine-induced changes in metabolic profiles of rat faeces and intervention effects of ergosta-4,6,8(14),22-tetraen-3-one

Ergosta-4,6,8(14),22-tetraen-3-one (ergone), isolated from the medicinal fungus Polyporus umbellatus, has been proven to prevent the progression of renal injury and the subsequent renal fibrosis. Ultra performance liquid chromatography coupled with quadrupole time-of-flight high-sensitivity mass spectrometry and a novel mass spectrometry(Elevated Energy) (MS(E)) data collection technique was employed to investigate metabonomic characters of chronic renal failure (CRF) induced adenine and the protective effects of ergosta-4,6,8(14),22-tetraen-3-one (ergone). Coupled with blood biochemistry and kidney histopathology results, the significant difference in metabolic profiling between adenine-induced CRF group and ergone-treated CRF group by using pattern recognition analysis indicated that changes in global faecal metabolites were occurred. Seven endogenous metabolites were identified by using metabonomic method combined with multivariate data analysis, the accurate mass, isotopic pattern, MS(E) fragments information and MassLynx i-FIT algorithm. These biochemical changes in faecal metabolites are related to the perturbations of bile acid metabolism and phospholipid metabolism, which may be helpful to further understand the CRF and therapeutic mechanisms of ergone. This research proved that MS(E) can simultaneous acquire precursor ion information and fragment ion data at high and low collision energy in one analytical run, which facilitated the fast structural characterization of metabolites.

Metabolomics analysis reveals the association between lipid abnormalities and oxidative stress, inflammation, fibrosis, and Nrf2 dysfunction in aristolochic acid-induced nephropathy

Alternative medicines are commonly used for the disease prevention and treatment worldwide. Aristolochic acid (AAI) nephropathy (AAN) is a common and rapidly progressive interstitial nephropathy caused by ingestion of Aristolochia herbal medications. Available data on pathophysiology and molecular mechanisms of AAN are limited and were explored here. SD rats were randomized to AAN and control groups. AAN group was treated with AAI by oral gavage for 12 weeks and observed for additional 12 weeks. Kidneys were processed for histological evaluation, Western blotting, and metabolomics analyses using UPLC-QTOF/HDMS. The concentrations of two phosphatidylcholines, two diglycerides and two acyl-carnitines were significantly altered in AAI treated rats at week 4 when renal function and histology were unchanged. Data obtained on weeks 8 to 24 revealed progressive tubulointerstitial fibrosis, inflammation, renal dysfunction, activation of NF-κB, TGF-β, and oxidative pathways, impaired Nrf2 system, and profound changes in lipid metabolites including numerous PC, lysoPC, PE, lysoPE, ceramides and triglycerides. In conclusion, exposure to AAI results in dynamic changes in kidney tissue fatty acid, phospholipid, and glycerolipid metabolisms prior to and after the onset of detectable changes in renal function or histology. These findings point to participation of altered tissue lipid metabolism in the pathogenesis of AAN.