1
|
Dai X, Lv C, Sun J, Li S. A facile synthesis of isotope labeled acylcarnitines. J Labelled Comp Radiopharm 2021; 64:217-224. [PMID: 33480078 DOI: 10.1002/jlcr.3904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 01/16/2021] [Accepted: 01/19/2021] [Indexed: 11/10/2022]
Abstract
Acylcarnitines are a big family of small molecule metabolites with various acyl groups attached to the hydroxyl moiety of l-carnitine. They are good indicators of multiple metabolic disorders. For instance, the newborn screening panel uses flow injection tandem mass spectrometry to analyze more than 30 different acylcarnitines and amino acids extracted from dried blood spots. A facile approach has been developed for the synthesis of isotope labeled acylcarnitines whose mass shift over their unlabeled counterparts can be any number in the range of 3 to 12 Da. This strategy makes it more convenient to provide authentic internal standards for acylcarnitines profiling analyses, thereby expanding their clinical applications.
Collapse
Affiliation(s)
- Xiaojun Dai
- Department of Public Security Administration, Nanjing Forest Police College, Nanjing, China
| | - Chao Lv
- Department of Research and Development, Nanjing Apollomics Biotech, Inc., Nanjing, China
| | - Jianguo Sun
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Shuwei Li
- Department of Research and Development, Nanjing Apollomics Biotech, Inc., Nanjing, China
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| |
Collapse
|
2
|
Wang Y, Christopher BA, Wilson KA, Muoio D, McGarrah RW, Brunengraber H, Zhang GF. Propionate-induced changes in cardiac metabolism, notably CoA trapping, are not altered by l-carnitine. Am J Physiol Endocrinol Metab 2018; 315:E622-E633. [PMID: 30016154 PMCID: PMC6230704 DOI: 10.1152/ajpendo.00081.2018] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
High concentrations of propionate and its metabolites are found in several diseases that are often associated with the development of cardiac dysfunction, such as obesity, diabetes, propionic acidemia, and methylmalonic acidemia. In the present work, we employed a stable isotope-based metabolic flux approach to understand propionate-mediated perturbation of cardiac energy metabolism. Propionate led to accumulation of propionyl-CoA (increased by ~101-fold) and methylmalonyl-CoA (increased by 36-fold). This accumulation caused significant mitochondrial CoA trapping and inhibited fatty acid oxidation. The reduced energy contribution from fatty acid oxidation was associated with increased glucose oxidation. The enhanced anaplerosis of propionate and CoA trapping altered the pool sizes of tricarboxylic acid cycle (TCA) metabolites. In addition to being an anaplerotic substrate, the accumulation of proprionate-derived malate increased the recycling of malate to pyruvate and acetyl-CoA, which can enter the TCA for energy production. Supplementation of 3 mM l-carnitine did not relieve CoA trapping and did not reverse the propionate-mediated fuel switch. This is due to new findings that the heart appears to lack the specific enzyme catalyzing the conversion of short-chain (C3 and C4) dicarboxylyl-CoAs to dicarboxylylcarnitines. The discovery of this work warrants further investigation on the relevance of dicarboxylylcarnitines, especially C3 and C4 dicarboxylylcarnitines, in cardiac conditions such as heart failure.
Collapse
Affiliation(s)
- Yingxue Wang
- Department of Endocrinology and Metabolism, The First Affiliated Hospital, Jinan University , Guangzhou , China
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University , Durham, North Carolina
| | - Bridgette A Christopher
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University , Durham, North Carolina
- Department of Medicine, Duke University , Durham, North Carolina
| | - Kirkland A Wilson
- Department of Nutrition, Case Western Reserve University , Cleveland, Ohio
| | - Deborah Muoio
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University , Durham, North Carolina
- Department of Medicine, Duke University , Durham, North Carolina
| | - Robert W McGarrah
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University , Durham, North Carolina
- Department of Medicine, Duke University , Durham, North Carolina
| | - Henri Brunengraber
- Department of Nutrition, Case Western Reserve University , Cleveland, Ohio
| | - Guo-Fang Zhang
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University , Durham, North Carolina
- Department of Medicine, Duke University , Durham, North Carolina
| |
Collapse
|
3
|
Minkler PE, Stoll MSK, Ingalls ST, Hoppel CL. Selective, Accurate, and Precise Quantitation of Glutarylcarnitine in Human Urine from a Patient with Glutaric Acidemia Type I. J Appl Lab Med 2017; 2:335-344. [DOI: 10.1373/jalm.2017.024281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 08/09/2017] [Indexed: 11/06/2022]
Abstract
Abstract
Background
Although correctly used in expanded newborn screening programs to identify patients with possible diseases, flow-injection tandem mass spectrometry (MS/MS) acylcarnitine “profiles” are inadequate for standard clinical uses owing to their limited quantitative accuracy and lack of selectivity. We report the application of our selective, accurate, and precise method for quantification of acylcarnitines, applied to urine glutarylcarnitine from a patient with glutaric acidemia type I (GAI).
Methods
A previously validated acylcarnitine ultra-HPLC-MS/MS method was used, with a focus on analysis of glutarylcarnitine. Calibrants and samples were isolated by solid-phase extraction and derivatized with pentafluorophenacyl trifluoromethanesulfonate. Acylcarnitine pentafluorophenacyl esters were eluted in 14-min chromatograms. Standardized calibrants and a 13-point, 200-fold concentration range calibration curve were used for accurate quantification of glutarylcarnitine. Quality control samples validated method accuracy and long-term analytic stability.
Results
Quantification of glutarylcarnitine in urine from a patient with GAI is reported. Long-term analytical stability of the method over a 5-year period is shown.
Conclusions
Our method for acylcarnitine quantification is shown to be selective, accurate, and precise; thus, we recommend it for confirmatory testing and monitoring of plasma and urine samples from patients with GAI.
Collapse
Affiliation(s)
- Paul E Minkler
- Center for Mitochondrial Diseases, Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Maria S K Stoll
- Center for Mitochondrial Diseases, Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Stephen T Ingalls
- Center for Mitochondrial Diseases, Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Charles L Hoppel
- Center for Mitochondrial Diseases, Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH
| |
Collapse
|
4
|
Minkler PE, Stoll MSK, Ingalls ST, Hoppel CL. Selective and accurate C5 acylcarnitine quantitation by UHPLC-MS/MS: Distinguishing true isovaleric acidemia from pivalate derived interference. J Chromatogr B Analyt Technol Biomed Life Sci 2017; 1061-1062:128-133. [PMID: 28734160 DOI: 10.1016/j.jchromb.2017.07.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 06/22/2017] [Accepted: 07/09/2017] [Indexed: 10/19/2022]
Abstract
Tandem MS acylcarnitine "profiles" are extremely valuable. Although used appropriately in newborn screening programs to identify patients with possible diseases, their inadequate quantitative accuracy and lack of selectivity is problematic for confirmatory testing. In this report, we show the application of our validated, selective, accurate, precise, and robust UHPLC-MS/MS method for quantitation of acylcarnitines, specifically to C5 acylcarnitines: pivaloyl-, 2-methylbutyryl-, isovaleryl-, and valerylcarnitine. Standardized calibrants were used to generate 13-point, 200-fold concentration range calibration curves. Samples were isolated by solid-phase extraction and derivatized with pentafluorophenacyl trifluoromethanesulfonate. Acylcarnitine pentafluorophenacyl esters were eluted in 14min chromatograms. Data demonstrating quantitative stability and method robustness over a five year time period are shown and these results validate the method's accuracy and robustness. Urine from patients with isovaleric acidemia (with the disease marker isovalerylcarnitine) and with pivaloylcarnitine present are shown. These results demonstrate the method's ability to distinguish true isovaleric acidemia from pivalate derived interference. Our method for acylcarnitine quantitation is shown to be accurate, precise, and robust for selective quantitation of isovalerylcarnitine, and thus is recommended for confirmatory testing of suspected isovaleric acidemia patients.
Collapse
Affiliation(s)
- Paul E Minkler
- Center for Mitochondrial Diseases, Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Maria S K Stoll
- Center for Mitochondrial Diseases, Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Stephen T Ingalls
- Center for Mitochondrial Diseases, Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Charles L Hoppel
- Center for Mitochondrial Diseases, Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA; Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
| |
Collapse
|
5
|
Minkler PE, Stoll MSK, Ingalls ST, Kerner J, Hoppel CL. Quantitative acylcarnitine determination by UHPLC-MS/MS--Going beyond tandem MS acylcarnitine "profiles". Mol Genet Metab 2015; 116:231-41. [PMID: 26458767 PMCID: PMC5009370 DOI: 10.1016/j.ymgme.2015.10.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 10/06/2015] [Accepted: 10/07/2015] [Indexed: 01/22/2023]
Abstract
Tandem MS "profiling" of acylcarnitines and amino acids was conceived as a first-tier screening method, and its application to expanded newborn screening has been enormously successful. However, unlike amino acid screening (which uses amino acid analysis as its second-tier validation of screening results), acylcarnitine "profiling" also assumed the role of second-tier validation, due to the lack of a generally accepted second-tier acylcarnitine determination method. In this report, we present results from the application of our validated UHPLC-MS/MS second-tier method for the quantification of total carnitine, free carnitine, butyrobetaine, and acylcarnitines to patient samples with known diagnoses: malonic acidemia, short-chain acyl-CoA dehydrogenase deficiency (SCADD) or isobutyryl-CoA dehydrogenase deficiency (IBD), 3-methyl-crotonyl carboxylase deficiency (3-MCC) or ß-ketothiolase deficiency (BKT), and methylmalonic acidemia (MMA). We demonstrate the assay's ability to separate constitutional isomers and diastereomeric acylcarnitines and generate values with a high level of accuracy and precision. These capabilities are unavailable when using tandem MS "profiles". We also show examples of research interest, where separation of acylcarnitine species and accurate and precise acylcarnitine quantification is necessary.
Collapse
MESH Headings
- Acetyl-CoA C-Acyltransferase/blood
- Acetyl-CoA C-Acyltransferase/cerebrospinal fluid
- Acetyl-CoA C-Acyltransferase/deficiency
- Acetyl-CoA C-Acyltransferase/urine
- Acyl-CoA Dehydrogenase/blood
- Acyl-CoA Dehydrogenase/cerebrospinal fluid
- Acyl-CoA Dehydrogenase/deficiency
- Acyl-CoA Dehydrogenase/urine
- Amino Acid Metabolism, Inborn Errors/blood
- Amino Acid Metabolism, Inborn Errors/cerebrospinal fluid
- Amino Acid Metabolism, Inborn Errors/diagnosis
- Amino Acid Metabolism, Inborn Errors/urine
- Betaine/analogs & derivatives
- Betaine/blood
- Betaine/cerebrospinal fluid
- Betaine/urine
- Carbon-Carbon Ligases/blood
- Carbon-Carbon Ligases/cerebrospinal fluid
- Carbon-Carbon Ligases/deficiency
- Carbon-Carbon Ligases/urine
- Carnitine/analogs & derivatives
- Carnitine/blood
- Carnitine/cerebrospinal fluid
- Carnitine/urine
- Chromatography, High Pressure Liquid/methods
- Chromatography, High Pressure Liquid/standards
- Female
- Humans
- Infant, Newborn
- Isomerism
- Lipid Metabolism, Inborn Errors/blood
- Lipid Metabolism, Inborn Errors/cerebrospinal fluid
- Lipid Metabolism, Inborn Errors/diagnosis
- Lipid Metabolism, Inborn Errors/urine
- Male
- Neonatal Screening
- Reproducibility of Results
- Sensitivity and Specificity
- Tandem Mass Spectrometry/standards
- Urea Cycle Disorders, Inborn/blood
- Urea Cycle Disorders, Inborn/cerebrospinal fluid
- Urea Cycle Disorders, Inborn/diagnosis
- Urea Cycle Disorders, Inborn/urine
Collapse
Affiliation(s)
- Paul E Minkler
- Center for Mitochondrial Diseases, Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Maria S K Stoll
- Center for Mitochondrial Diseases, Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Stephen T Ingalls
- Center for Mitochondrial Diseases, Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Janos Kerner
- Center for Mitochondrial Diseases, Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Charles L Hoppel
- Center for Mitochondrial Diseases, Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA; Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
| |
Collapse
|
6
|
Kraus WE, Muoio DM, Stevens R, Craig D, Bain JR, Grass E, Haynes C, Kwee L, Qin X, Slentz DH, Krupp D, Muehlbauer M, Hauser ER, Gregory SG, Newgard CB, Shah SH. Metabolomic Quantitative Trait Loci (mQTL) Mapping Implicates the Ubiquitin Proteasome System in Cardiovascular Disease Pathogenesis. PLoS Genet 2015; 11:e1005553. [PMID: 26540294 PMCID: PMC4634848 DOI: 10.1371/journal.pgen.1005553] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 09/04/2015] [Indexed: 12/15/2022] Open
Abstract
Levels of certain circulating short-chain dicarboxylacylcarnitine (SCDA), long-chain dicarboxylacylcarnitine (LCDA) and medium chain acylcarnitine (MCA) metabolites are heritable and predict cardiovascular disease (CVD) events. Little is known about the biological pathways that influence levels of most of these metabolites. Here, we analyzed genetics, epigenetics, and transcriptomics with metabolomics in samples from a large CVD cohort to identify novel genetic markers for CVD and to better understand the role of metabolites in CVD pathogenesis. Using genomewide association in the CATHGEN cohort (N = 1490), we observed associations of several metabolites with genetic loci. Our strongest findings were for SCDA metabolite levels with variants in genes that regulate components of endoplasmic reticulum (ER) stress (USP3, HERC1, STIM1, SEL1L, FBXO25, SUGT1) These findings were validated in a second cohort of CATHGEN subjects (N = 2022, combined p = 8.4x10-6–2.3x10-10). Importantly, variants in these genes independently predicted CVD events. Association of genomewide methylation profiles with SCDA metabolites identified two ER stress genes as differentially methylated (BRSK2 and HOOK2). Expression quantitative trait loci (eQTL) pathway analyses driven by gene variants and SCDA metabolites corroborated perturbations in ER stress and highlighted the ubiquitin proteasome system (UPS) arm. Moreover, culture of human kidney cells in the presence of levels of fatty acids found in individuals with cardiometabolic disease, induced accumulation of SCDA metabolites in parallel with increases in the ER stress marker BiP. Thus, our integrative strategy implicates the UPS arm of the ER stress pathway in CVD pathogenesis, and identifies novel genetic loci associated with CVD event risk. Cardiovascular disease is a strongly heritable trait. Despite application of the latest genomic technologies, the genetic architecture of disease risk remains poorly defined, and mechanisms underlying this susceptibility are incompletely understood. In this study, we performed genome-wide mapping of heart disease-related metabolites measured in the blood as the genetic traits of interest (instead of the disease itself), in a large cohort of 3512 patients at risk of heart disease from the CATHGEN study. Our goal was to discover new cardiovascular disease genes and thereby mechanisms of disease pathogenesis by understanding the genes that regulate levels of these metabolites. These analyses identified novel genetic variants associated with metabolite levels and with cardiovascular disease itself. Importantly, by utilizing an unbiased systems-based approach integrating genetics, gene expression, epigenetics and metabolomics, we uncovered a novel pathway of heart disease pathogenesis, that of endoplasmic reticulum (ER) stress, represented by elevated levels of circulating short-chain dicarboxylacylcarnitine (SCDA) metabolites.
Collapse
Affiliation(s)
- William E. Kraus
- Division of Cardiology, Department of Medicine, Duke University, Durham, North Carolina, United States of America
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
| | - Deborah M. Muoio
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
- Division of Endocrinology, Department of Medicine, Duke University, Durham, North Carolina, United States of America
| | - Robert Stevens
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
| | - Damian Craig
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
| | - James R. Bain
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
| | - Elizabeth Grass
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
| | - Carol Haynes
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
| | - Lydia Kwee
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
| | - Xuejun Qin
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
| | - Dorothy H. Slentz
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
| | - Deidre Krupp
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
| | - Michael Muehlbauer
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
| | - Elizabeth R. Hauser
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
- Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina, United States of America
| | - Simon G. Gregory
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
| | - Christopher B. Newgard
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
| | - Svati H. Shah
- Division of Cardiology, Department of Medicine, Duke University, Durham, North Carolina, United States of America
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
- * E-mail:
| |
Collapse
|
7
|
Minkler PE, Stoll MSK, Ingalls ST, Kerner J, Hoppel CL. Validated method for the quantification of free and total carnitine, butyrobetaine, and acylcarnitines in biological samples. Anal Chem 2015; 87:8994-9001. [PMID: 26270397 DOI: 10.1021/acs.analchem.5b02198] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A validated quantitative method for the determination of free and total carnitine, butyrobetaine, and acylcarnitines is presented. The versatile method has four components: (1) isolation using strong cation-exchange solid-phase extraction, (2) derivatization with pentafluorophenacyl trifluoromethanesulfonate, (3) sequential ion-exchange/reversed-phase (ultra) high-performance liquid chromatography [(U)HPLC] using a strong cation-exchange trap in series with a fused-core HPLC column, and (4) detection with electrospray ionization multiple reaction monitoring (MRM) mass spectrometry (MS). Standardized carnitine along with 65 synthesized, standardized acylcarnitines (including short-chain, medium-chain, long-chain, dicarboxylic, hydroxylated, and unsaturated acyl moieties) were used to construct multiple-point calibration curves, resulting in accurate and precise quantification. Separation of the 65 acylcarnitines was accomplished in a single chromatogram in as little as 14 min. Validation studies were performed showing a high level of accuracy, precision, and reproducibility. The method provides capabilities unavailable by tandem MS procedures, making it an ideal approach for confirmation of newborn screening results and for clinical and basic research projects, including treatment protocol studies, acylcarnitine biomarker studies, and metabolite studies using plasma, urine, tissue, or other sample matrixes.
Collapse
Affiliation(s)
- Paul E Minkler
- Center for Mitochondrial Diseases, †Department of Pharmacology and ‡Department of Medicine, Case Western Reserve University School of Medicine , Cleveland, Ohio 44106, United States
| | - Maria S K Stoll
- Center for Mitochondrial Diseases, †Department of Pharmacology and ‡Department of Medicine, Case Western Reserve University School of Medicine , Cleveland, Ohio 44106, United States
| | - Stephen T Ingalls
- Center for Mitochondrial Diseases, †Department of Pharmacology and ‡Department of Medicine, Case Western Reserve University School of Medicine , Cleveland, Ohio 44106, United States
| | - Janos Kerner
- Center for Mitochondrial Diseases, †Department of Pharmacology and ‡Department of Medicine, Case Western Reserve University School of Medicine , Cleveland, Ohio 44106, United States
| | - Charles L Hoppel
- Center for Mitochondrial Diseases, †Department of Pharmacology and ‡Department of Medicine, Case Western Reserve University School of Medicine , Cleveland, Ohio 44106, United States
| |
Collapse
|
8
|
Peng M, Fang X, Huang Y, Cai Y, Liang C, Lin R, Liu L. Separation and identification of underivatized plasma acylcarnitine isomers using liquid chromatography-tandem mass spectrometry for the differential diagnosis of organic acidemias and fatty acid oxidation defects. J Chromatogr A 2013; 1319:97-106. [PMID: 24169039 DOI: 10.1016/j.chroma.2013.10.036] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2013] [Revised: 10/06/2013] [Accepted: 10/10/2013] [Indexed: 10/26/2022]
Abstract
A simple HPLC-MS/MS method has been established to separate and identify underivatized acylcarnitine isomers. Human plasma samples were deproteinized and concentrated. Acylcarnitines were separated on a reverse phase column and detected with triple quadrupole linear ion trap mass spectrometry. Deuterium-labeled internal standards were used for quantitation. To identify acylcarnitines without pure standards, information-dependent acquisition linking to enhanced product ion scan mode was used. 112 acylcarnitines, including stereoisomers, were found in samples of patients. Dicarboxylic acylcarnitines, such as methylmalonylcarnitine and glutarylcarnitine, were detected with high sensitivity. Three stereoisomers of (R,S)2-methyl-3-hydroxy butyrylcarnitine were detected in samples of patients with β-ketothiolase deficiency. Validation results revealed excellent precision and accuracy of the method. In general the within- and between-run coefficients of variation (CV%) were less than 15%, and recoveries were in the range of 92.7-117.5%. In addition, the reference intervals of acylcarnitines for children aged 3-day to13-year old were established. Using the new method and reference intervals, we have correctly diagnosed 49 patients with fatty acid oxidation defects or organic acidemias in 176 high-risk patients.
Collapse
Affiliation(s)
- Minzhi Peng
- The Laboratory of Endocrinology and Metabolism, Guangzhou Women and Children's Medical Center, 9 Jinsui Road, Guangzhou, China
| | | | | | | | | | | | | |
Collapse
|
9
|
Peng M, Liu L, Jiang M, Liang C, Zhao X, Cai Y, Sheng H, Ou Z, Luo H. Measurement of free carnitine and acylcarnitines in plasma by HILIC-ESI-MS/MS without derivatization. J Chromatogr B Analyt Technol Biomed Life Sci 2013; 932:12-8. [PMID: 23816563 DOI: 10.1016/j.jchromb.2013.05.028] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 05/22/2013] [Accepted: 05/25/2013] [Indexed: 12/30/2022]
Abstract
Measurement of carnitine and acylcarnitines in plasma is important in diagnosis of fatty acid β-oxidation disorders and organic acidemia. The usual method uses flow injection tandem mass spectrometry (FIA-MS/MS), which has limitations. A rapid and more accurate method was developed to be used for high-risk screening and diagnosis. Carnitine and acylcarnitines were separated by hydrophilic interaction liquid chromatography (HILIC) without derivatization and detected with a QTRAP MS/MS System. Total analysis time was 9.0min. The imprecision of within- and between-run were less than 6% and 17%, respectively. Recoveries were in the range of 85-110% at three concentrations. Some acylcarnitine isomers could be separated, such as dicarboxylic and hydroxyl acylcarnitines. The method could also separate interferent to avoid false positive results. 216 normal samples and 116 patient samples were detected with the validated method, and 49 patients were identified with fatty acid oxidation disorders or organic acidemias.
Collapse
Affiliation(s)
- Minzhi Peng
- The Laboratory of Endocrinology and Metabolism, Guangzhou Women and Children's Medical Center, No. 9 Jinsui Road, Guangzhou, China
| | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Baseline metabolomic profiles predict cardiovascular events in patients at risk for coronary artery disease. Am Heart J 2012; 163:844-850.e1. [PMID: 22607863 DOI: 10.1016/j.ahj.2012.02.005] [Citation(s) in RCA: 243] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 02/08/2012] [Indexed: 11/24/2022]
Abstract
BACKGROUND Cardiovascular risk models remain incomplete. Small-molecule metabolites may reflect underlying disease and, as such, serve as novel biomarkers of cardiovascular risk. METHODS We studied 2,023 consecutive patients undergoing cardiac catheterization. Mass spectrometry profiling of 69 metabolites and lipid assessments were performed in fasting plasma. Principal component analysis reduced metabolites to a smaller number of uncorrelated factors. Independent relationships between factors and time-to-clinical events were assessed using Cox modeling. Clinical and metabolomic models were compared using log-likelihood and reclassification analyses. RESULTS At median follow-up of 3.1 years, there were 232 deaths and 294 death/myocardial infarction (MI) events. Five of 13 metabolite factors were independently associated with mortality: factor 1 (medium-chain acylcarnitines: hazard ratio [HR] 1.12 [95% CI, 1.04-1.21], P = .005), factor 2 (short-chain dicarboxylacylcarnitines: HR 1.17 [1.05-1.31], P = .005), factor 3 (long-chain dicarboxylacylcarnitines: HR 1.14 [1.05-1.25], P = .002); factor 6 (branched-chain amino acids: HR 0.86 [0.75-0.99], P = .03), and factor 12 (fatty acids: HR 1.19 [1.06-1.35], P = .004). Three factors independently predicted death/MI: factor 2 (HR 1.11 [1.01-1.23], P = .04), factor 3 (HR 1.13 [1.04-1.22], P = .005), and factor 12 (HR 1.18 [1.05-1.32], P = .004). For mortality, 27% of intermediate-risk patients were correctly reclassified (net reclassification improvement 8.8%, integrated discrimination index 0.017); for death/MI model, 11% were correctly reclassified (net reclassification improvement 3.9%, integrated discrimination index 0.012). CONCLUSIONS Metabolic profiles predict cardiovascular events independently of standard predictors.
Collapse
|
11
|
Metabolic profiles predict adverse events after coronary artery bypass grafting. J Thorac Cardiovasc Surg 2012; 143:873-8. [PMID: 22306227 DOI: 10.1016/j.jtcvs.2011.09.070] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Revised: 08/18/2011] [Accepted: 09/15/2011] [Indexed: 11/21/2022]
Abstract
OBJECTIVE Clinical models incompletely predict the outcomes after coronary artery bypass grafting. Novel molecular technologies can identify biomarkers to improve risk stratification. We examined whether metabolic profiles can predict adverse events in patients undergoing coronary artery bypass grafting. METHODS The study population comprised 478 subjects from the CATHGEN biorepository of patients referred for cardiac catheterization who underwent coronary artery bypass grafting after enrollment. Targeted mass spectrometry-based profiling of 69 metabolites was performed in frozen, fasting plasma samples collected before surgery. Principal components analysis and Cox proportional hazards regression modeling were used to assess the relation between the metabolite factor levels and a composite outcome of postcoronary artery bypass grafting myocardial infarction, the need for percutaneous coronary intervention, repeat coronary artery bypass grafting, and death. RESULTS During a mean follow-up period of 4.3 ± 2.4 years, 126 subjects (26.4%) experienced an adverse event. Three principal components analysis-derived factors were significantly associated with an adverse outcome on univariate analysis: short-chain dicarboxylacylcarnitines (factor 2, P = .001); ketone-related metabolites (factor 5, P = .02); and short-chain acylcarnitines (factor 6, P = .004). These 3 factors remained independently predictive of an adverse outcome after multivariate adjustment: factor 2 (adjusted hazard ratio, 1.23; 95% confidence interval, 1.10-1.38; P < .001), factor 5 (odds ratio, 1.17; 95% confidence interval, 1.01-1.37; P = .04), and factor 6 (odds ratio, 1.14; 95% confidence interval, 1.02-1.27; P = .03). CONCLUSIONS Metabolic profiles are independently associated with adverse outcomes after coronary artery bypass grafting. These profiles might represent novel biomarkers of risk that can augment existing tools for risk stratification of coronary artery bypass grafting patients and might elucidate novel biochemical pathways that mediate risk.
Collapse
|
12
|
Johnson DW. An acid hydrolysis method for quantification of plasma free and total carnitine by flow injection tandem mass spectrometry. Clin Biochem 2010; 43:1362-7. [DOI: 10.1016/j.clinbiochem.2010.08.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 08/03/2010] [Accepted: 08/08/2010] [Indexed: 11/15/2022]
|
13
|
|
14
|
Addition of formic acid improves acetonitrile extraction of dicarboxylic acylcarnitines. Clin Chim Acta 2009; 404:169-70. [DOI: 10.1016/j.cca.2009.03.040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Revised: 02/27/2009] [Accepted: 03/18/2009] [Indexed: 11/18/2022]
|
15
|
Duranti G, Boenzi S, Rizzo C, Ravà L, Di Ciommo V, Carrozzo R, Meschini MC, Johnson DW, Dionisi-Vici C. Urine acylcarnitine analysis by ESI–MS/MS: A new tool for the diagnosis of peroxisomal biogenesis disorders. Clin Chim Acta 2008; 398:86-9. [DOI: 10.1016/j.cca.2008.08.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Revised: 08/06/2008] [Accepted: 08/21/2008] [Indexed: 10/21/2022]
|
16
|
Maeda Y, Ito T, Suzuki A, Kurono Y, Ueta A, Yokoi K, Sumi S, Togari H, Sugiyama N. Simultaneous quantification of acylcarnitine isomers containing dicarboxylic acylcarnitines in human serum and urine by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2007; 21:799-806. [PMID: 17279485 DOI: 10.1002/rcm.2905] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Tandem mass spectrometry (MS/MS) has become a prominent method for screening newborns for diseases such as organic acidemia and fatty acid oxidation defects, although current methods cannot separate acylcarnitine isomers. Accurate determination of dicarboxylic acylcarnitines such as methylmalonylcarnitine and glutarylcarnitine has not been carried out, because obtaining standards of these acylcarnitines is difficult. We attempted the individual determinations of acylcarnitines with isomers and dicarboxylic acylcarnitines by applying high-performance liquid chromatography (HPLC). Chromatographic separation was performed by gradient elution using a mixture of 0.08% aqueous ion-pairing agent and acetonitrile as the mobile phase. Mass transitions of m/z 161.8-->84.8 for carnitine and m/z 164.8-->84.8 for deuterated carnitine were monitored in positive ion electrospray ionization mode. One carnitine and 16 acylcarnitines were quantified. The limit of quantitation (LOQ) was 0.1 micromol/L for methylmalonylcarnitine and 0.05 micromol/L for the other acylcarnitines. Intra-day and inter-day coefficients of variance (CVs) were <8.3% and <8.8%, respectively, for all acylcarnitines in serum, and both were <9.2% in urine. Mean recoveries were >90% for all acylcarnitines. Human samples were quantified by this method. After addition of deuterated acylcarnitines as internal standards, acylcarnitines in serum or urine were extracted using a solid-phase extraction cartridge. In healthy adult individuals, isobutyryl-, 2-methylbutyryl- and isovalerylcarnitine were detected in serum and urine. Dicarboxylic acylcarnitines were detected in urine. High concentrations of methylmalonylcarnitine and propionylcarnitine were found in both the serum and the urine of a patient with methylmalonic acidemia. The described HPLC/MS/MS method could separate most acylcarnitine isomers and quantify them, potentially allowing detailed diagnoses and follow-up treatment for those diseases.
Collapse
Affiliation(s)
- Yasuhiro Maeda
- Laboratory of Hospital Pharmacy, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Abstract
Malonylcarnitine and glutarylcarnitine are important diagnostic metabolites in the screening of dried blood spots by tandem mass spectrometry. The stability of these compounds in spiked blood spots stored at room temperature was studied. Both showed biphasic curves. The malonylcarnitine concentration dropped to 61% in 38 days and averaged 51% +/- 5% for the next 81 days. Glutarylcarnitine dropped to 60% in 42 days and averaged 56% +/- 5% for the next 124 days.
Collapse
Affiliation(s)
- D W Johnson
- Department of Genetic Medicine, Women's and Children's Hospital, North Adelaide, South Australia 5006, Australia.
| | | |
Collapse
|