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Nestor L, De Bundel D, Vander Heyden Y, Smolders I, Van Eeckhaut A. Unravelling the brain metabolome: A review of liquid chromatography - mass spectrometry strategies for extracellular brain metabolomics. J Chromatogr A 2023; 1712:464479. [PMID: 37952387 DOI: 10.1016/j.chroma.2023.464479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 10/27/2023] [Accepted: 10/29/2023] [Indexed: 11/14/2023]
Abstract
The analysis of the brain extracellular metabolome is of interest for numerous subdomains within neuroscience. Not only does it provide information about normal physiological functions, it is even more of interest for biomarker discovery and target discovery in disease. The extracellular analysis of the brain is particularly interesting as it provides information about the release of mediators in the brain extracellular fluid to look at cellular signaling and metabolic pathways through the release, diffusion and re-uptake of neurochemicals. In vivo samples are obtained through microdialysis, cerebral open-flow microperfusion or solid-phase microextraction. The analytes of potential interest are typically low in concentration and can have a wide range of physicochemical properties. Liquid chromatography coupled to mass spectrometry has proven its usefulness in brain metabolomics. It allows sensitive and specific analysis of low sample volumes, obtained through different approaches. Several strategies for the analysis of the extracellular fluid have been proposed. The most widely used approaches apply sample derivatization, specific stationary phases and/or hydrophilic interaction liquid chromatography. Miniaturization of these methods allows an even higher sensitivity. The development of chiral metabolomics is indispensable, as it allows to compare the enantiomeric ratio of compounds and provides even more challenges. Some limitations continue to exist for the previously developed methods and the development of new, more sensitive methods remains needed. This review provides an overview of the methods developed for sampling and liquid chromatography-mass spectrometry analysis of the extracellular metabolome.
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Affiliation(s)
- Liam Nestor
- Research group Experimental Pharmacology (EFAR), Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels, Belgium
| | - Dimitri De Bundel
- Research group Experimental Pharmacology (EFAR), Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels, Belgium
| | - Yvan Vander Heyden
- Department of Analytical Chemistry, Applied Chemometrics and Molecular Modelling (FABI), Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels, Belgium
| | - Ilse Smolders
- Research group Experimental Pharmacology (EFAR), Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels, Belgium
| | - Ann Van Eeckhaut
- Research group Experimental Pharmacology (EFAR), Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels, Belgium.
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Liu D, Lin Z, Jia C. NeuroCNN_GNB: an ensemble model to predict neuropeptides based on a convolution neural network and Gaussian naive Bayes. Front Genet 2023; 14:1226905. [PMID: 37576553 PMCID: PMC10414792 DOI: 10.3389/fgene.2023.1226905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 06/30/2023] [Indexed: 08/15/2023] Open
Abstract
Neuropeptides contain more chemical information than other classical neurotransmitters and have multiple receptor recognition sites. These characteristics allow neuropeptides to have a correspondingly higher selectivity for nerve receptors and fewer side effects. Traditional experimental methods, such as mass spectrometry and liquid chromatography technology, still need the support of a complete neuropeptide precursor database and the basic characteristics of neuropeptides. Incomplete neuropeptide precursor and information databases will lead to false-positives or reduce the sensitivity of recognition. In recent years, studies have proven that machine learning methods can rapidly and effectively predict neuropeptides. In this work, we have made a systematic attempt to create an ensemble tool based on four convolution neural network models. These baseline models were separately trained on one-hot encoding, AAIndex, G-gap dipeptide encoding and word2vec and integrated using Gaussian Naive Bayes (NB) to construct our predictor designated NeuroCNN_GNB. Both 5-fold cross-validation tests using benchmark datasets and independent tests showed that NeuroCNN_GNB outperformed other state-of-the-art methods. Furthermore, this novel framework provides essential interpretations that aid the understanding of model success by leveraging the powerful Shapley Additive exPlanation (SHAP) algorithm, thereby highlighting the most important features relevant for predicting neuropeptides.
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Affiliation(s)
- Di Liu
- Information Science and Technology College, Dalian Maritime University, Dalian, China
| | - Zhengkui Lin
- Information Science and Technology College, Dalian Maritime University, Dalian, China
| | - Cangzhi Jia
- School of Science, Dalian Maritime University, Dalian, China
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3
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Lei X, Huang T, Wu X, Mangelings D, Van Eeckhaut A, Bongaerts J, Terryn H, Vander Heyden Y. Fabrication of a molecularly imprinted monolithic column via the epitope approach for the selective capillary microextraction of neuropeptides in human plasma. Talanta 2022; 243:123397. [DOI: 10.1016/j.talanta.2022.123397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 03/15/2022] [Accepted: 03/17/2022] [Indexed: 10/18/2022]
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Buchberger AR, DeLaney K, Liu Y, Vu NQ, Helfenbein K, Li L. Mass Spectrometric Profiling of Neuropeptides in Callinectes sapidus during Hypoxia Stress. ACS Chem Neurosci 2020; 11:3097-3106. [PMID: 32840999 DOI: 10.1021/acschemneuro.0c00439] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Oxygen (O2) is a critical component of life; without proper O2 levels, cells are unable to respire, meaning glucose cannot be utilized. Thus, hypoxia (low O2 levels) is a well-documented stressor, especially in aquatic environments. Neuropeptides are a major class of regulators for stress-induced responses; however, their global expression changes during stress are not well characterized due to the natural complexity of the nervous system. Beyond being a neurological model organism, crustaceans are regularly exposed to hypoxia, making them a relevant system for this study. Several neuropeptide families, including orcokinins, RFamides, and allatostatin A-types, show dynamic dysregulation due to hypoxic stress. In particular, the brain showed the most dynamic changes with a survival mechanism "switching" (i.e., significant increase to decrease) of neuropeptide content between moderate and severe hypoxia (e.g., NFDEDRSGFA, FDAFTTGFGHS, NRNFLRFamide, and APSGFLGMRamide). Globally, neuropeptides in different tissues appeared to exhibit unique expression patterns at the various severities of hypoxia, including LSSSNSPSSTPL and NFDEIDRSSFGF. Overall, this study provides clear evidence for the benefits of globally analyzing biomolecules and that neuropeptides play a critical role in how crustaceans adapt due to hypoxic stress.
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Affiliation(s)
- Amanda R. Buchberger
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53705, United States
| | - Kellen DeLaney
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53705, United States
| | - Yang Liu
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53705, United States
| | - Nhu Q. Vu
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53705, United States
| | - Kylie Helfenbein
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53705, United States
| | - Lingjun Li
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53705, United States
- School of Pharmacy, University of Wisconsin-Madison, 5125 Rennebohm Hall, 777 Highland Drive, Madison, Wisconsin 53706, United States
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Assessing mixtures of supercharging agents to increase the abundance of a specific charge state of Neuromedin U. Talanta 2019; 198:206-214. [PMID: 30876551 DOI: 10.1016/j.talanta.2019.01.098] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 01/28/2019] [Accepted: 01/29/2019] [Indexed: 11/24/2022]
Abstract
With increasing evidence of the important role of peptides in pathophysiological processes, a trend towards the development of highly sensitive bioanalytical methods is ongoing. Inherent to the electrospray ionization process of peptides and proteins is the production of multiple charge states which may hamper proper and sensitive method development. Supercharging agents allow modifying the maximal charge state and the corresponding distribution of charges, thereby potentially increasing the number of ions reaching the detector in selected reaction monitoring mode. In this study, the use of mixtures of charge state modifying additives, i.e. m-nitrobenzylalcohol (mNBA), sulfolane and dimethyl sulfoxide (DMSO), to specifically increase the abundance of one charge state of interest has been investigated. Screening experiments were performed to define an experimental domain, which was then further investigated via a response surface design to predict the optimal combination and concentration of superchargers. Using a combination of mNBA and DMSO (0.008% and 0.5% m/v respectively), we were able to increase the abundance of the +4 charge state of the investigated peptide neuromedin U from 64% to 87%. Unfortunately, charge state coalescence did not result in repeatable sensitivity improvements in this case study. However, it remains an attractive approach during method development of peptide bioanalytical methods, as coalescence to a particular intermediate charge state is difficult to obtain by using only one supercharging agent.
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Van Wanseele Y, Maes K, Lanckmans K, Van Schoors J, Smolders I, Van Eeckhaut A. Surface and Solvent Dependent Adsorption of Three Neuromedin-Like Peptides in Glass and Plastic Syringes. Chromatographia 2017. [DOI: 10.1007/s10337-017-3397-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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7
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Van Wanseele Y, Viaene J, Van den Borre L, Dewachter K, Vander Heyden Y, Smolders I, Van Eeckhaut A. LC-method development for the quantification of neuromedin-like peptides. Emphasis on column choice and mobile phase composition. J Pharm Biomed Anal 2017; 137:104-112. [DOI: 10.1016/j.jpba.2017.01.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/05/2017] [Accepted: 01/06/2017] [Indexed: 01/17/2023]
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Challenges for the in vivo quantification of brain neuropeptides using microdialysis sampling and LC-MS. Bioanalysis 2016; 8:1965-85. [PMID: 27554986 DOI: 10.4155/bio-2016-0119] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In recent years, neuropeptides and their receptors have received an increased interest in neuropharmacological research. Although these molecules are considered relatively small compared with proteins, their in vivo quantification using microdialysis is more challenging than for small molecules. Low microdialysis recoveries, aspecific adsorption and the presence of various multiply charged precursor ions during ESI-MS/MS detection hampers the in vivo quantification of these low abundant biomolecules. Every step in the workflow, from sampling until analysis, has to be optimized to enable the sensitive analysis of these compounds in microdialysates.
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Van Schoors J, Viaene J, Van Wanseele Y, Smolders I, Dejaegher B, Vander Heyden Y, Van Eeckhaut A. An improved microbore UHPLC method with electrochemical detection for the simultaneous determination of low monoamine levels in in vivo brain microdialysis samples. J Pharm Biomed Anal 2016; 127:136-46. [DOI: 10.1016/j.jpba.2016.01.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 12/19/2015] [Accepted: 01/07/2016] [Indexed: 12/26/2022]
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Wagner L, Björkqvist M, Lundh SH, Wolf R, Börgel A, Schlenzig D, Ludwig HH, Rahfeld JU, Leavitt B, Demuth HU, Petersén Å, von Hörsten S. Neuropeptide Y (NPY) in cerebrospinal fluid from patients with Huntington's Disease: increased NPY levels and differential degradation of the NPY1-30
fragment. J Neurochem 2016; 137:820-37. [DOI: 10.1111/jnc.13624] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 03/17/2016] [Accepted: 03/20/2016] [Indexed: 12/31/2022]
Affiliation(s)
- Leona Wagner
- Deutschsprachige Selbsthilfegruppe für Alkaptonurie (DSAKU) e.V.; Stuttgart Germany
- Probiodrug AG; Halle (Saale) Germany
- Department of Experimental Therapy; Franz-Penzoldt-Center; Friedrich-Alexander-University Erlangen-Nürnberg; Erlangen Germany
| | - Maria Björkqvist
- Brain Disease Biomarker Unit; Department of Experimental Medical Science; Wallenberg Neuroscience Centre; Lund University; Lund Sweden
| | - Sofia Hult Lundh
- Translational Neuroendocrine Research Unit; Lund University; Lund Sweden
| | - Raik Wolf
- Probiodrug AG; Halle (Saale) Germany
- Center for Clinical Chemistry, Microbiology and Transfusion; Klinikum St. Georg GmbH; Leipzig Germany
| | - Arne Börgel
- Probiodrug AG; Halle (Saale) Germany
- Institute of Molecular Biology (IMB); Johannes Gutenberg-University Mainz; Mainz Germany
| | - Dagmar Schlenzig
- Department of Drug Design and Target Validation; Fraunhofer-Institute for Cell Therapy and Immunology; Halle (Saale) Germany
| | | | - Jens-Ulrich Rahfeld
- Department of Drug Design and Target Validation; Fraunhofer-Institute for Cell Therapy and Immunology; Halle (Saale) Germany
| | - Blair Leavitt
- The Centre for Molecular Medicine and Therapeutics Child and Family Research Institute; BC Children's Hospital; The University of British Columbia; Vancouver British Columbia
| | - Hans-Ulrich Demuth
- Department of Drug Design and Target Validation; Fraunhofer-Institute for Cell Therapy and Immunology; Halle (Saale) Germany
| | - Åsa Petersén
- Translational Neuroendocrine Research Unit; Lund University; Lund Sweden
| | - Stephan von Hörsten
- Department of Experimental Therapy; Franz-Penzoldt-Center; Friedrich-Alexander-University Erlangen-Nürnberg; Erlangen Germany
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Van Schoors J, Maes K, Van Wanseele Y, Broeckhoven K, Van Eeckhaut A. Miniaturized ultra-high performance liquid chromatography coupled to electrochemical detection: Investigation of system performance for neurochemical analysis. J Chromatogr A 2016; 1427:69-78. [DOI: 10.1016/j.chroma.2015.11.076] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 11/19/2015] [Accepted: 11/24/2015] [Indexed: 01/03/2023]
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12
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An ultrasensitive nano UHPLC-ESI-MS/MS method for the quantification of three neuromedin-like peptides in microdialysates. Bioanalysis 2015; 7:605-19. [PMID: 25826142 DOI: 10.4155/bio.14.269] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
AIM An ultrasensitive nano UHPLC-ESI-MS/MS method is developed to simultaneously monitor three low-concentration neuromedin-like peptides in microdialysates. RESULTS Peptide preconcentration and sample desalting is performed online on a trap column. A shallow gradient slope at 300 nl/min on the analytical column maintained at 35°C, followed by two saw-tooth column wash cycles, results in the highest sensitivity and the lowest carryover. The validated method allows the accurate and precise quantification of 0.5 pM neurotensin and neuromedin N (2.5 amol on column), and of 3.0 pM neuromedin B (15.0 amol on column) in in vivo microdialysates without the use of internal standards. CONCLUSION The assay is an important tool for elucidating the role of these neuromedin-like peptides in the pathophysiology of neurological disorders.
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Li H, Li D. Preparation of a pipette tip-based molecularly imprinted solid-phase microextraction monolith by epitope approach and its application for determination of enkephalins in human cerebrospinal fluid. J Pharm Biomed Anal 2015; 115:330-8. [DOI: 10.1016/j.jpba.2015.07.033] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 06/25/2015] [Accepted: 07/22/2015] [Indexed: 12/11/2022]
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Van Schoors J, Lens C, Maes K, Michotte Y, Smolders I, Van Eeckhaut A. Reassessment of the antioxidative mixture for the challenging electrochemical determination of dopamine, noradrenaline and serotonin in microdialysis samples. J Chromatogr B Analyt Technol Biomed Life Sci 2015; 998-999:63-71. [DOI: 10.1016/j.jchromb.2015.06.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 05/18/2015] [Accepted: 06/12/2015] [Indexed: 10/23/2022]
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15
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Buchberger A, Yu Q, Li L. Advances in Mass Spectrometric Tools for Probing Neuropeptides. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2015; 8:485-509. [PMID: 26070718 PMCID: PMC6314846 DOI: 10.1146/annurev-anchem-071114-040210] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Neuropeptides are important mediators in the functionality of the brain and other neurological organs. Because neuropeptides exist in a wide range of concentrations, appropriate characterization methods are needed to provide dynamic, chemical, and spatial information. Mass spectrometry and compatible tools have been a popular choice in analyzing neuropeptides. There have been several advances and challenges, both of which are the focus of this review. Discussions range from sample collection to bioinformatic tools, although avenues such as quantitation and imaging are included. Further development of the presented methods for neuropeptidomic mass spectrometric analysis is inevitable, which will lead to a further understanding of the complex interplay of neuropeptides and other signaling molecules in the nervous system.
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Affiliation(s)
- Amanda Buchberger
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706-1322;
| | - Qing Yu
- School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705-2222;
| | - Lingjun Li
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706-1322;
- School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705-2222;
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Ji X, Li D, Li H. Preparation and application of a novel molecularly imprinted solid-phase microextraction monolith for selective enrichment of cholecystokinin neuropeptides in human cerebrospinal fluid. Biomed Chromatogr 2015; 29:1280-9. [DOI: 10.1002/bmc.3418] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 11/15/2014] [Accepted: 11/28/2014] [Indexed: 11/10/2022]
Affiliation(s)
- Xiang Ji
- College of Chemistry and Molecular Sciences; Wuhan University; Wuhan 430072 China
| | - Dan Li
- College of Chemistry and Molecular Sciences; Wuhan University; Wuhan 430072 China
| | - Hua Li
- College of Chemistry and Molecular Sciences; Wuhan University; Wuhan 430072 China
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17
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Quantification of endogenous metabolites by the postcolumn infused-internal standard method combined with matrix normalization factor in liquid chromatography–electrospray ionization tandem mass spectrometry. J Chromatogr A 2015; 1375:62-8. [DOI: 10.1016/j.chroma.2014.11.073] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 11/03/2014] [Accepted: 11/27/2014] [Indexed: 11/19/2022]
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18
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Improved sensitivity of the nano ultra-high performance liquid chromatography-tandem mass spectrometric analysis of low-concentrated neuropeptides by reducing aspecific adsorption and optimizing the injection solvent. J Chromatogr A 2014; 1360:217-28. [DOI: 10.1016/j.chroma.2014.07.086] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 07/15/2014] [Accepted: 07/27/2014] [Indexed: 11/18/2022]
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Maes K, Smolders I, Michotte Y, Van Eeckhaut A. Strategies to reduce aspecific adsorption of peptides and proteins in liquid chromatography-mass spectrometry based bioanalyses: an overview. J Chromatogr A 2014; 1358:1-13. [PMID: 25022477 DOI: 10.1016/j.chroma.2014.06.072] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 06/11/2014] [Accepted: 06/22/2014] [Indexed: 12/20/2022]
Abstract
In the drug-discovery setting, the development of new peptide and protein-based biopharmaceuticals attracts increased attention from the pharmaceutical industry and consequently demands the development of high-throughput LC-MS methods. Regulatory guidelines require bioanalytical methods to be validated not only in terms of linearity, sensitivity, accuracy, precision, selectivity and stability, but also in terms of carryover. Carryover results from the aspecific adsorption of analyte(s) to parts of the analytical system and thus introduces bias in both identification and quantification assays. Moreover, nonspecific binding occurs at the surface of materials used during sample preparation, such as pipette tips, sample tubes and LC-vials. Hence, linearity, sensitivity and repeatability of the analyses are negatively affected. Due to the great diversity in physicochemical properties of biomolecules, there is no general approach available to minimize adsorption phenomena. Therefore, we aim to present different strategies which can be generically applied to reduce nonspecific binding of peptides and proteins. In the first part of this review, a systematic approach is proposed to guide the reader through the different solvents which can be used to dissolve the analyte of interest. Indeed, proper solubilization is one of the most important factors for a successful analysis. In addition, alternative approaches are described to improve analyte recovery from the sample vial. The second part focuses on strategies to efficiently reduce adsorption at components of the autosampler, column and mass spectrometer. Thereby carryover is reduced while maintaining a sufficiently wide dynamic range of the assay.
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Affiliation(s)
- Katrien Maes
- Department of Pharmaceutical Chemistry and Drug Analysis, Center for Neurosciences (C4N), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium
| | - Ilse Smolders
- Department of Pharmaceutical Chemistry and Drug Analysis, Center for Neurosciences (C4N), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium
| | - Yvette Michotte
- Department of Pharmaceutical Chemistry and Drug Analysis, Center for Neurosciences (C4N), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium
| | - Ann Van Eeckhaut
- Department of Pharmaceutical Chemistry and Drug Analysis, Center for Neurosciences (C4N), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium.
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Quarta D, Smolders I. Rewarding, reinforcing and incentive salient events involve orexigenic hypothalamic neuropeptides regulating mesolimbic dopaminergic neurotransmission. Eur J Pharm Sci 2014; 57:2-10. [DOI: 10.1016/j.ejps.2014.01.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 01/19/2014] [Indexed: 12/22/2022]
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Abstract
Currently, chromatography (GC but more commonly HPLC) is the analytical method of choice for several hormones, either because the immunoassays suffer from extensive crossreactivity or because chromatography permits simultaneous measurements of hormones. However, sometimes the conventional detection systems with HPLC methods do not meet desired specificity. With the increase of robust and affordable LC–MS/MS systems, the next step forward in specificity was taken. LC–MS/MS is rapidly being incorporated in the endocrine laboratories. To be useful in the clinical diagnostic practice, it is of utmost importance that methods are both analytically and clinically vaidated, as until now, the majority of applications of LC–MS/MS in the clinical laboratories are ‘home-made’ methods, therefore special case must be taken. This review aims to focus on Clinical and Laboratory Standards Institute or comparable validated LC–MS/MS methods for targeted hormone analysis used for diagnostic purposes in human samples, published in the last 5 years.
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Ion-pair ultra-high performance liquid chromatographic analysis of monoamines: Peak-splitting at high flow rates. J Chromatogr A 2013; 1321:73-9. [DOI: 10.1016/j.chroma.2013.10.070] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 10/21/2013] [Accepted: 10/22/2013] [Indexed: 11/22/2022]
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23
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Kennedy RT. Emerging trends in in vivo neurochemical monitoring by microdialysis. Curr Opin Chem Biol 2013; 17:860-7. [PMID: 23856056 DOI: 10.1016/j.cbpa.2013.06.012] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 06/11/2013] [Indexed: 12/31/2022]
Abstract
Mapping chemical dynamics in the brain of live subjects is a challenging but highly rewarding goal because it allows neurotransmitter fluctuations to be related to behavior, drug effects, and disease states. A popular method for such measurements is microdialysis sampling coupled to analytical measurements. This method has become well-established for monitoring low molecular weight neurotransmitters, metabolites, and drugs, especially in pharmacological and pharmacokinetic studies. Recent technological developments which improve the temporal and spatial resolution of the methods will enable it to be used for studying behavior and small brain nuclei. Better assays allow monitoring more neurotransmitters simultaneously. Extension to analysis of aggregating proteins like amyloid β is proving extremely useful for uncovering the roles of these molecules and how they contribute to neurodegenerative diseases.
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Affiliation(s)
- Robert T Kennedy
- Departments of Chemistry and Pharmacology, University of Michigan, Ann Arbor, MI, United States.
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24
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Xi L, Jin Y, Parker EA, Josh P, Jones A, Wijffels G, Colgrave ML. Challenges in mass spectrometry-based quantification of bioactive peptides: a case study exploring the neuropeptide Y family. Biopolymers 2013. [PMID: 23193600 DOI: 10.1002/bip.22109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The study of biologically active peptides is critical to the understanding of physiological pathways, especially those involved in the development of disease. Historically, the measurement of biologically active endogenous peptides has been undertaken by radioimmunoassay, a highly sensitive and robust technique that permits the detection of physiological concentrations in different biofluid and tissue extracts. Over recent years, a range of mass spectrometric approaches have been applied to peptide quantification with limited degrees of success. Neuropeptide Y (NPY), peptide YY (PYY), and pancreatic polypeptide (PP) belong to the NPY family exhibiting regulatory effects on appetite and feeding behavior. The physiological significance of these peptides depends on their molecular forms and in vivo concentrations systemically and at local sites within tissues. In this report, we describe an approach for quantification of individual peptides within mixtures using high-performance liquid chromatography electrospray ionization tandem mass spectrometry analysis of the NPY family peptides. Aspects of quantification including sample preparation, the use of matrix-matched calibration curves, and internal standards will be discussed. This method for the simultaneous determination of NPY, PYY, and PP was accurate and reproducible but lacks the sensitivity required for measurement of their endogenous concentration in plasma. The advantages of mass spectrometric quantification will be discussed alongside the current obstacles and challenges.
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Affiliation(s)
- Li Xi
- College of Veterinary Medicine, Northwest A&F University, Xi'an 712100, China
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25
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Schmerberg CM, Li L. Mass spectrometric detection of neuropeptides using affinity-enhanced microdialysis with antibody-coated magnetic nanoparticles. Anal Chem 2013; 85:915-22. [PMID: 23249250 DOI: 10.1021/ac302403e] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Microdialysis (MD) is a useful sampling tool for many applications due to its ability to permit sampling from an animal concurrent with normal activity. MD is of particular importance in the field of neuroscience, in which it is used to sample neurotransmitters (NTs) while the animal is behaving in order to correlate dynamic changes in NTs with behavior. One important class of signaling molecules, the neuropeptides (NPs), however, presented significant challenges when studied with MD, due to the low relative recovery (RR) of NPs by this technique. Affinity-enhanced microdialysis (AE-MD) has previously been used to improve recovery of NPs and similar molecules. For AE-MD, an affinity agent (AA), such as an antibody-coated particle or free antibody, is added to the liquid perfusing the MD probe. This AA provides an additional mass transport driving force for analyte to pass through the dialysis membrane and thus increases the RR. In this work, a variety of AAs have been investigated for AE-MD of NPs in vitro and in vivo, including particles with C18 surface functionality and antibody-coated particles. Antibody-coated magnetic nanoparticles (AbMnP) provided the best RR enhancement in vitro, with statistically significant (p < 0.05) enhancements for 4 out of 6 NP standards tested, and RR increases up to 41-fold. These particles were then used for in vivo MD in the Jonah crab, Cancer borealis, during a feeding study, with mass spectrometric (MS) detection. 31 NPs were detected in a 30 min collection sample, compared to 17 when no AA was used. The use of AbMnP also increased the temporal resolution from 4 to 18 h in previous studies to just 30 min in this study. The levels of NPs detected were also sufficient for reliable quantitation with the MS system in use, permitting quantitative analysis of the concentration changes for 7 identified NPs on a 30 min time course during feeding.
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Affiliation(s)
- Claire M Schmerberg
- School of Pharmacy, University of Wisconsin, 777 Highland Avenue, Madison, Wisconsin 53705, USA
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Souchelnytskyi S. INDIVIDUALIZATION OF CANCER TREATMENT: CONTRIBUTION OF OMICS TECHNOLOGIES TO CANCER DIAGNOSTIC. BIOTECHNOLOGIA ACTA 2013. [DOI: 10.15407/biotech6.04.105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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27
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28
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Sun L, Li H, Willson K, Breidinger S, Rizk ML, Wenning L, Woolf EJ. Ultrasensitive Liquid Chromatography–Tandem Mass Spectrometric Methodologies for Quantification of Five HIV-1 Integrase Inhibitors in Plasma for a Microdose Clinical Trial. Anal Chem 2012; 84:8614-21. [PMID: 23030780 DOI: 10.1021/ac301581h] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Li Sun
- Merck Research Laboratories,
West Point, Pennsylvania, 19486, United States
| | - Hankun Li
- Merck Research Laboratories,
West Point, Pennsylvania, 19486, United States
| | - Kenneth Willson
- Merck Research Laboratories,
West Point, Pennsylvania, 19486, United States
| | - Sheila Breidinger
- Merck Research Laboratories,
West Point, Pennsylvania, 19486, United States
| | - Matthew L. Rizk
- Merck Research Laboratories,
West Point, Pennsylvania, 19486, United States
| | - Larissa Wenning
- Merck Research Laboratories,
West Point, Pennsylvania, 19486, United States
| | - Eric J. Woolf
- Merck Research Laboratories,
West Point, Pennsylvania, 19486, United States
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29
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Mabrouk OS, Kennedy RT. Simultaneous oxytocin and arg-vasopressin measurements in microdialysates using capillary liquid chromatography-mass spectrometry. J Neurosci Methods 2012; 209:127-33. [PMID: 22710285 DOI: 10.1016/j.jneumeth.2012.06.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 06/06/2012] [Accepted: 06/06/2012] [Indexed: 11/19/2022]
Abstract
Oxytocin (OXT) and arg-vasopressin (AVP) are nonapeptides with many important functions both peripherally and centrally. Intracerebral microdialysis has helped characterize their importance in regulating complex social and emotional processes. Radioiummunoassay is the most commonly used analytical method used for OXT and AVP measurements in microdialysates. These measurements have several well-known issues including single peptide per assay limit, possible cross-reactivity between structurally related peptides, and laborious sample preparation with radioactive materials. Here we demonstrate the use of capillary LC-MS(3) for measuring OXT and AVP simultaneously in dialysates at a 10 min sampling frequency. Microdialysate samples required no preparation and instrumentation was commercially available. Microdialysis probes made with polyacrylonitrile membranes were suitable for high level recovery of the peptides in vitro and in vivo. Responses were linear from 1 to 100 pM. Matrix effect was assessed by standard addition experiments and by comparing signal intensities of OXT and AVP standards made in aCSF or dialysate. It was determined that the online washing step used on this setup was adequate for removing contaminants which interfere with electrospray ionization efficiency. In vivo, both peptides were stimulated by high K(+) (75 mM) aCSF perfusion in the paraventricular nucleus (PVN). Also, a systemic injection of high Na(+) (2M) caused a rapid and transient increase in PVN OXT while AVP increased only after 1.5h. Our findings suggest that capillary LC-MS(3) is a straightforward method for monitoring OXT and AVP simultaneously from complex samples such as dialysates.
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Affiliation(s)
- Omar S Mabrouk
- Department of Chemistry and Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
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Heywood W, Wang D, Madgett TE, Avent ND, Eaton S, Chitty LS, Mills K. The development of a peptide SRM-based tandem mass spectrometry assay for prenatal screening of Down syndrome. J Proteomics 2012; 75:3248-57. [PMID: 22543281 DOI: 10.1016/j.jprot.2012.03.037] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Revised: 03/05/2012] [Accepted: 03/22/2012] [Indexed: 01/16/2023]
Abstract
Two new biomarkers, serum amyloid-P (SAP) and plasma C1-inhibitor protein are elevated in the maternal circulation of mothers carrying Down syndrome foetuses. Much emphasis of late\ has been put on the lack of translational tests being developed following the identification of new biomarkers. We have created a single-reaction-monitoring (SRM) tandem mass spectrometry-based assay for the quantitation of these biomarkers and compared these results with an in-house developed immunofluorescence-based technique (IF). This MS-based assay is a rapid 5 min test and a simple "one pot reaction," requiring only 5μl of plasma. To evaluate the potential of SRM-based quantitation in a clinical setting, SAP and C1-inhibitor were quantitated in 38 normal and Down syndrome affected pregnancies. Plasma SAP levels in the Down's group were significantly raised at 10-14 weeks (p<0.0015) and 14-20 weeks (p<0.0001). Plasma C1-inhibitor levels were also observed significantly elevated in the Down's group (10-14 weeks, p<0.0193, 14-20 weeks, p<0.0001). Analysis using the IF technique did not show any significant elevation of plasma SAP levels or C1-inhibitor levels. This rapid and sensitive assay demonstrates the potential of multiplexed tandem MS-based quantitation of proteins in chemical pathology labs and in a more cost-effective, accurate manner than conventionally used antibody methods.
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Affiliation(s)
- Wendy Heywood
- Clinical and Molecular Genetics Unit, Institute of Child Health, University College London, UK
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