Metabolomics in chronic kidney disease

Chronic kidney disease (CKD) represents a major challenge to public healthcare. Traditional clinical biomarkers of renal function (blood urea nitrogen and serum creatinine) are not sensitive or specific enough and only increase significantly after the presence of substantial CKD. Therefore, more sensitive biomarkers of CKD are needed. CKD-specific biomarkers at an early disease stage and early diagnosis of specific renal diseases would enable improved therapeutic treatment and reduced the personal and financial burdens. The goal of metabolomics is to identify non-targeted, global small-molecule metabolite profiles of complex samples, such as biofluids and tissues. This method offers the potential for a holistic approach to clinical medicine, as well as improvements in disease diagnoses and the understanding of pathological mechanisms. This review article presents an overview of the recent developments in the field of metabolomics, followed by an in-depth discussion of its application to the study of CKD (primary, chronic glomerulonephritis such as IgA nephropathy; secondary, chronic renal injury such as diabetic nephropathy; chronic renal failure including end-stage kidney disease with and without undergoing replacement therapies, etc), including metabolomic analytical technologies, chemometrics, and metabolomics in experimental and clinical research. We describe the current status of the identification of metabolic biomarkers in CKD. Several markers have been confirmed across multiple studies to detect CKD earlier than traditional clinical chemical and histopathological methods. The application of metabolomics in CKD studies provides researchers the opportunity to gain new insights into metabolic profiling and pathophysiological mechanisms. Particular challenges in the field are presented and placed within the context of future applications of metabolomic approaches to the studies of CKD.

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.

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/MS(E)

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-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-based metabonomic applications for discovering biomarkers of diseases in clinical chemistry

OBJECTIVES

Metabonomics is a powerful and promising analytic tool that allows assessment of global low-molecular-weight metabolites in biological systems. It has a great potential for identifying useful biomarkers for early diagnosis, prognosis and assessment of therapeutic interventions in clinical practice. The aim of this review is to provide a brief summary of the recent advances in UPLC-based metabonomic approach for biomarker discovery in a variety of diseases, and to discuss their significance in clinical chemistry.

DESIGN AND METHODS

All the available information on UPLC-based metabonomic applications for discovering biomarkers of diseases were collected via a library and electronic search (using Web of Science, Pubmed, ScienceDirect, Springer, Google Scholar, etc.).

RESULTS

Metabonomics has been used in clinical chemistry to identify and evaluate potential biomarkers and therapeutic targets in various diseases affecting the liver (hepatocarcinoma and liver cirrhosis), lung (lung cancer and pneumonia), gastrointestinal tract (colorectal cancer) and urogenital tract (prostate cancer, ovarian cancer and chronic kidney disease), as well as metabolic diseases (diabetes) and neuropsychiatric disorders (Alzheimer's disease and schizophrenia), etc.

CONCLUSIONS

The information provided highlights the potential value of determination of endogenous low-molecular-weight metabolites and the advantages and potential drawbacks of the application of UPLC-based metabonomics in clinical setting.

UPLC-MS(E) 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.

Lipidomics: Novel insight into the biochemical mechanism of lipid metabolism and dysregulation-associated disease

The application of lipidomics, after genomics, proteomics and metabolomics, offered largely opportunities to illuminate the entire spectrum of lipidome based on a quantitative or semi-quantitative level in a biological system. When combined with advances in proteomics and metabolomics high-throughput platforms, lipidomics provided the opportunity for analyzing the unique roles of specific lipids in complex cellular processes. Abnormal lipid metabolism was demonstrated to be greatly implicated in many human lifestyle-related diseases. In this review, we focused on lipidomic applications in brain injury disease, cancer, metabolic disease, cardiovascular disease, respiratory disease and infectious disease to discover disease biomarkers and illustrate biochemical metabolic pathways. We also discussed the analytical techniques, future perspectives and potential problems of lipidomic applications. The application of lipidomics in disease biomarker discovery provides the opportunity for gaining novel insights into biochemical mechanism.

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 spectrometry(Elevated 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.

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.

Traditional uses, phytochemistry, pharmacology, pharmacokinetics and quality control of Polyporus umbellatus (Pers.) Fries: a review

ETHNOPHARMACOLOGICAL RELEVANCE

Polyporus umbellatus (Pers.) Fries (Polyporaceae, Zhuling ) has been commonly used in medicine for a wide range of ailments related to the edema, scanty urine, vaginal discharge, urinary dysfunction, as well as jaundice and diarrhea.

AIM OF THE REVIEW

The present paper reviewed the traditional uses, propagation, phytochemistry, pharmacology, pharmacokinetics and quality control of Polyporus umbellatus.

MATERIALS AND METHODS

All the available information on Polyporus umbellatus was collected via a library and electronic search (using Web of Science, Pubmed, ScienceDirect, Splinker, Google Scholar, etc.).

RESULTS

Phytochemical studies showed the presence of many valuable secondary metabolites such as steroids, polysaccharides, anthraquinones and nucleosides. Crude extracts and isolated compounds showed a wide spectrum of pharmacological activities including diuretic, nephroprotective, anti-cancer, immuno-enhancing, hepatoprotective, anti-inflammatory and antioxidative activities. The pharmacokinetic studies demonstrated that the ergosterol and ergone had a high distribution and absorption in the plasma and the two main components of Polyporus umbellatus were mainly excreted by faeces. The determination of multiple chemical components was successfully applied to the quality control of Polyporus umbellatus.

CONCLUSIONS

Modern phytochemical, pharmacological and metabonomic investigations showed that the crude extracts and isolated compounds from Polyporus umbellatus possess many kinds of biological functions, especially in the diuretic activities and the treatment of kidney diseases as well as anti-cancer, immuno-enhancing and hepatoprotective activities. The pathways of the distribution, absorption, metabolism and excretion of main steroidal compounds were clarified by pharmacokinetic studies. Most of the pharmacological studies were conducted using crude and poorly characterized extracts of Polyporus umbellatus in animals especially in case of diuretic activities and the treatment of kidney diseases. Thus, more bioactive components especially diuretic compounds should be identified using bioactivity-guided isolation strategies and the possible mechanism of action as well as potential synergistic or antagonistic effects of multi-component mixtures derived from Polyporus umbellatus need to be evaluated integrating pharmacological, pharmacokinetic, bioavailability-centered and physiological approaches. In addition, more experiments including in vitro, in vivo and clinical studies should be encouraged to identify any side effects or toxicity. These achievements will further expand the existing therapeutic potential of Polyporus umbellatus and provide a beneficial support to its future further clinical use in modern medicine.

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-Q-TOF/HSMS/MS(E)-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.

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

Chronic renal failure (CRF) is a major challenge for the public healthcare problem. A novel UPLC Q-TOF/MS method with MS(E) 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, MS(E) 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.

Urinary metabonomic study of the surface layer of Poria cocos as an effective treatment for chronic renal injury in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Poria cocos Wolf (Polyporaceae) is a well-known medicinal fungus. The epidermis of the sclerotia ("Fu-Ling-Pi" in Chinese) is used as a diuretic and traditionally used for promoting urination and reduce edema.

AIM OF THE STUDY

Traditional Chinese medicines (TCM) treat many diseases through multi-components, multi-ways and multi-targets. However, the molecular mechanisms of TCM are not yet well understood. In the present work, ultra performance liquid chromatography-based metabonomics analysis was applied to investigate the urinary metabolite profiling of the renoprotective effect of FLP on adenine-induced chronic kidney disease (CKD) rat model and involved possible mechanism.

MATERIAL AND METHODS

A metabonomic approach based on ultra performance liquid chromatography coupled with quadrupole time-of-flight high-sensitivity mass spectrometry and a novel mass spectrometry(Elevated Energy) data collection technique was developed. The resulting dataset was analyzed by principal component analysis and partial least squares discriminant analysis. The identification of all potential biomarkers was performed using reference standard by comparing their mass spectra, MS(E) fragments information, isotopic pattern and MassLynx i-FIT algorithm.

RESULTS

By partial least squares-discriminate analysis, 15 biomarkers in rat urine were identified and 11 of them were related to the pathway of adenine metabolism and amino acid metabolism. Among these biomarkers, eight biomarkers like adenine, L-acetylcarnitine, 8-hydroxyadenine, hypoxanthine, creatine, methionine, phytosphingosine and phenylalanine were reversed to the control level in FLP-treated group and six biomarkers like 2,8-dihydroxyadenine, indole-3-carboxylic acid, 3-methyldioxyindole, ethyl-N2-acetyl-L-argininate, 3-O-methyldopa and xanthurenic acid were reversed to high control group by FLP, which indicates that the urinary metabolic pattern significantly changed after FLP treatment.

CONCLUSIONS

Our study indicates that FLP treatment can ameliorate CKD by intervening in some dominating metabolic pathways, such as adenine metabolism and amino acid metabolism. The metabonomic results not only supplied a systematic view of the development and progression of CKD and mechanism studies of FLP but also provided the theoretical basis for the prevention or treatment of CKD.

Bioactivity-directed isolation, identification of diuretic compounds from Polyporus umbellatus

AIM OF THE STUDY

Polyporus umbellatus is a fungus used as a diuretic medicine. The objective of this study was to isolate and elucidate the diuretic constituents of n-hexane, ethyl acetate, n-butanol and water extracts of Polyporus umbellatus and to evaluate their diuretic activity.

MATERIALS AND METHODS

The n-hexane, ethyl acetate, n-butanol and water extracts of Polyporus umbellatus were tested by diuretic experiment of normal rats in metabolic cage. The n-hexane extract and n-butanol extract were prepared separately by the bioassay-guided approach. Three isolated compounds doses (5, 10 and 20 mg/kg BW) were orally administered to normal rats. Water excretion rate, pH and content of Na(+), K(+) and Cl(-) were measured in the urine of saline-loaded rats.

RESULTS

n-Hexane extract (P<0.05), n-butanol extract (P<0.05) and three isolated compounds (ergosta-4,6,8(14),22-tetraen-3-one, ergosterol and d-mannitol) displayed diuretic activity.

CONCLUSIONS

The ergosta-4,6,8(14),22-tetraen-3-one was the strongest diuretic constituent in the three compounds. Ergosterol and D-mannitol were found to be also responsible for duiretic effects in Polyporus umbellatus for the first time. Data show that 20 mg/kg dose of the ergosterol for urine out put became significantly higher than in the control rats, but the ratio of Na(+)/K(+) almost unaltered in the three doses. The highest dose of the D-mannitol was significant and increased the cumulative urine output. Regarding the electrolyte excretion, data show that the doses 10 and 20 mg/kg produce significant increase for excretion of Na(+) and Cl(-). The present results provide a quantitative basis explaining application of Polyporus umbellatus as a diuretic medicine. The result proved that its diuretic effects were also due to the contribution of multi-components in clinical application.

Diuretic activity of the ethanol and aqueous extracts of the surface layer of Poria cocos in rat

ETHNOPHARMACOLOGICAL RELEVANCE

Poria cocos Wolf (Polyporaceae) is a well-known traditional East-Asian medicinal fungus. the epidermis ("Fu-Ling-Pi" in Chinese) of the sclerotia is used as a diuretic. This study was conducted to evaluate of ethanol extract (EE) and aqueous extract (AE) of the diuretic activity of Fu-Ling-Pi in saline-loaded rats.

MATERIAL AND METHODS

The EE and AE were orally administered to rats. Urinary excretion rate, pH and electrolyte excretion were measured in the urine of saline-loaded rats.

RESULTS

Urinary excretion rates were significantly increased by the EE. The three doses of AE only produced a slight increase urinary output. The EE had little or no effect on K(+) excretion, but did indeed induce a notable excretion of Na(+), that was in agreement with the urinary excretion. The three doses of AE produced an increase Na(+) and K(+) excretion, but did not arrive at statistical significance.

CONCLUSIONS

The present study confirmed that the not aqueous but ethanol extracts of the epidermis of Poria cocos presents a remarkable diuretic effect.

Ergosta-4,6,8(14),22-tetraen-3-one induces G2/M cell cycle arrest and apoptosis in human hepatocellular carcinoma HepG2 cells

BACKGROUND

Mushrooms have been used in Asia as traditional foods and medicines for a long time. Ergosta-4,6,8(14),22-tetraen-3-one (ergone) is one of the well-known bioactive steroids, which exists widely in various medicinal fungi such as Polyporus umbellatus, Russula cyanoxantha, and Cordyceps sinensis. Ergone has been demonstrated to possess cytotoxic activity. However, the molecular mechanisms by which ergone exerts its cytotoxic activity are currently unknown.

METHODS

In the present study, ergone possessed a remarkable anti-proliferative activity toward human hepatocellular carcinoma HepG2 cells. We assayed the cell cycle by flow cytometry using PI staining; investigated the exposure of phosphatidylserine at the outer layer of the cytoplasmic membrane by the FITC-annexin V/PI staining; observed the nuclear fragmentation by Hoechst 33258 staining and studied the protein expression of Bax, Bcl-2, p-53, procaspase-3, -8, -9, PARP and cleaved PARP by Western blotting analysis.

RESULTS

Cells treated with ergone showed typical markers of apoptosis: G2/M cell cycle arrest, chromatin condensation, nuclear fragmentation, and phosphatidylserine exposure. Furthermore, PARP-cleavage; activation of caspase-3, -8, -9; up-regulation of Bax and down-regulation of Bcl-2 were observed in HepG2 cells treated with ergone, which show that both the intrinsic and extrinsic apoptotic pathways are involved in ergone-induced apoptosis in HepG2 cells. Ergosta-4,6,8(14),22-tetraen-3-one induces G2/M cell cycle arrest and apoptosis in HepG2 cells in a caspase-dependent manner.

GENERAL SIGNIFICANCE

In this study, we reported for the first time that ergone-induced apoptosis through activating the caspase. These results would be useful for the further utilization of many medicinal fungi in cancer treatment.

Lipidomics applications for disease biomarker discovery in mammal models

Lipidomics is a lipid-targeted metabolomics approach focusing on comprehensive analysis of all lipids with which they interact in biology systems. Recent technological advances in MS and chromatography have greatly enhanced the developments and applications of metabolic profiling of diverse lipids in complex biological samples. Lipidomics will not only provide insights into the specific functions of lipid species in health and disease, but will also identify potential biomarkers for establishing preventive or therapeutic programs for human disease. In this review, recent applications of lipidomics to understand animal models of disease such as metabolic syndromes, neurodegenerative diseases, cancer and infectious diseases are considered. We also discuss the lipidomics for the future perspectives and their potential problems.

Renal metabolic profiling of early renal injury and renoprotective effects of Poria cocos epidermis using UPLC Q-TOF/HSMS/MSE

Poria cocos epidermis is one of ancient traditional Chinese medicines (TCMs), which is usually used for the treatment of chronic kidney disease (CKD) for thousands of years in China. A metabonomic approach based on ultra performance liquid chromatography coupled with quadrupole time-of-flight high-sensitivity mass spectrometry (UPLC Q-TOF/HSMS) and a mass spectrometry(Elevated Energy) (MS(E)) data collection technique was developed to obtained a systematic view of the development and progression of CKD and biochemistry mechanism of therapeutic effects of P. cocos epidermis (Fu-Ling-Pi, FLP). By partial least squares-discriminate analysis, 19 metabolites were identified as potential biomarkers of CKD. Among the 19 biomarkers, 10 biomarkers including eicosapentaenoic acid, docosahexaenoic acid, lysoPC(20:4), lysoPC(18:2), lysoPC(15:0), lysoPE(20:0/0:0), indoxyl sulfate, hippuric acid, p-cresol sulfate and allantoin were reversed to the control level in FLP-treated groups. The study indicates that FLP treatment can ameliorate CKD by intervening in some dominating metabolic pathways, such as fatty acid metabolism, phospholipid metabolism, purine metabolism and tryptophan metabolism. This work was for the first time to investigate the FLP therapeutic effect based on metabonomics technology, which is a potentially powerful tool to study the TCMs.

Ergosta-4,6,8(14),22-tetraen-3-one isolated from Polyporus umbellatus prevents early renal injury in aristolochic acid-induced nephropathy rats

OBJECTIVES

Aristolochic acid (AA) nephropathy, first reported as Chinese herbs nephropathy, is a rapidly progressive tubulointerstitial nephropathy that results in severe anemia, interstitial fibrosis and end-stage renal disease. Tubulointerstitial injury was studied in a rat model of AA nephropathy to determine whether ergosta-4,6,8(14),22-tetraen-3-one (ergone) treatment prevents early renal injury in rats with aristolochic acid I-induced nephropathy.

METHODS

Early renal injury via renal interstitial fibrosis was induced in rats by administration of aristolochic acid I (AAI) solution intragastrically for 8 weeks. Ninety-six rats were randomly divided into four groups (n = 24/group): (1) control (2) AAI (3) AAI + ergone (10 mg/kg) and (4) AAI + ergone (20 mg/kg). Blood and urine samples were collected and rat were sacrificed for histological assessment of the kidneys on at the end of weeks 2, 4, 6 and 8.

KEY FINDINGS

AAI caused progressive elevation of blood urea nitrogen, creatinine, potassium, sodium, chlorine, proteinuria and urinary N-acetyl-β-D-glucosaminidase (NAG). Ergone suppressed elevation of blood urea, nitrogen, creatinine, proteinuria and urinary NAG to some degree, but the AAI-ergone-treated group did not differ from AAI-treated group for body weight, serum potassium, sodium and chlorine. The progress of the lesions in the kidney after AAI administration was also observed by histopathological examinations, but kidneys from rats of AAI-ergone-treated group displayed fewer lesions.

CONCLUSIONS

Ergone treatment conferred protection against early renal injury in a rat model of AA nephropathy. Early administration of ergone may prevent the progression of renal injury and the subsequent renal fibrosis in AA nephropathy.

A pharmaco-metabonomic study on chronic kidney disease and therapeutic effect of ergone by UPLC-QTOF/HDMS

Chronic kidney disease (CKD) is an important public health problem. Ergone has been proved to prevent the progression of CKD. UPLC-QTOF/HDMS was employed for metabolic profiling of adenine-induced CKD and to investigate the nephroprotective effects of ergone. Pharmacology parameters including blood biochemistry, histopathological evaluation and Western blot analysis were performed concurrently. The UPLC-MS data were analyzed by partial least squares-discriminate analysis, correlation analysis, heatmap analysis and mapped to KEGG pathways. Blood and serum biochemistry were observed to be significantly different in the CKD group than in the control group. In conjunction with biochemistry, histopathology and protein expression results, identified metabolites indicated perturbations in fatty acid metabolism, purine metabolism and amino acid metabolism as changes associated with adenine-induced CKD and the interventions of ergone. Upregulated expression of TGF-β1, ED-1, CTGF, bFGF and collagen I was observed in the CKD group. However, downregulated expression of these proteins was observed after oral administration of ergone. These results suggest that expression changes in these proteins had implications for fatty acid metabolism, purine metabolism and amino acid metabolism in the development of CKD and that ergone treatment could delay the development of CKD by normalizing or blocking abnormal changes in biomarker metabolites and protein expression in the CKD group.

Urinary metabolomics and biomarkers of aristolochic acid nephrotoxicity by UPLC-QTOF/HDMS

BACKGROUND

Drug-induced nephrotoxicity was one of the most important health problems, with increasing morbidity and mortality. Urinary metabolomics based on ultra performance liquid chromatography coupled with quadrupole time-of-flight high-definition mass spectrometry was applied to aristolochic acid (AA) nephrotoxicity rats to characterize the excretion pathways of endogenous metabolites.

RESULTS

Compared with the control rats, serum creatinine, serum blood urea nitrogen and urine protein levels were significantly increased in AA nephrotoxicity rats. Metabolomics showed that metabolites including citrate, aconitate, fumarate, glucose, creatinine, p-cresyl sulfate, indoxyl sulfate, hippuric acid, phenylacetylglycine, kynurenic acid, indole-3-carboxylic acid, spermine, uric acid, allantoin, cholic acid and taurine were identified in AA nephrotoxicity rats.

CONCLUSION

The identified metabolites suggested that AA nephrotoxicity rats occurred perturbations in Krebs cycle, gut microflora metabolism, amino acid metabolism, purine metabolism and bile acid biosynthesis.

Cytotoxic steroids from Polyporus umbellatus

The steroids ergone (1), (22E, 24R)-ergosta-7,22-dien-3β-ol (2), 5α,8α-epidioxy-(22E,24R) -ergosta-6,22-dien-3β-ol (3), ergosta-6,22-dien-3β,5α,6β-triol (4), and polyporusterone B (5) were isolated from Polyporus umbellatus by bioassay-guided approach. They showed potent anticancer activity against HepG2 cells. Ergone displayed remarkable anticancer activity against HepG2, Hep-2, and Hela cancer cells, of which HepG2 cells were the most sensitive. Furthermore, the cytotoxic effects of ergone on normal human cells (HUVEC) were smaller than on cancer cells. The results showed that ergone had more selective cytotoxic activity against cancer cells than against normal cells.