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Rodrigues TB, Cunha RL, Barci PEP, Santos-Neto ÁJ, Lanças FM. Analysis of human biological samples using porous graphitic carbon columns and liquid chromatography-mass spectrometry: a review. Anal Bioanal Chem 2024; 416:5233-5253. [PMID: 39158631 DOI: 10.1007/s00216-024-05458-8] [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: 06/03/2024] [Revised: 07/18/2024] [Accepted: 07/23/2024] [Indexed: 08/20/2024]
Abstract
Liquid chromatography-mass spectrometry (LC-MS) has emerged as a powerful analytical technique for analyzing complex biological samples. Among various chromatographic stationary phases, porous graphitic carbon (PGC) columns have attracted significant attention due to their unique properties-such as the ability to separate both polar and non-polar compounds and their stability through all pH ranges and to high temperatures-besides the compatibility with LC-MS. This review discusses the applicability of PGC for SPE and separation in LC-MS-based analyses of human biological samples, highlighting the diverse applications of PGC-LC-MS in analyzing endogenous metabolites, pharmaceuticals, and biomarkers, such as glycans, proteins, oligosaccharides, sugar phosphates, and nucleotides. Additionally, the fundamental principles underlying PGC column chemistry and its advantages, challenges, and advances in method development are explored. This comprehensive review aims to provide researchers and practitioners with a valuable resource for understanding the capabilities and limitations of PGC columns in LC-MS-based analysis of human biological samples, thereby facilitating advancements in analytical methodologies and biomedical research.
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Affiliation(s)
- Taís Betoni Rodrigues
- Laboratory of Chromatography (CROMA), São Carlos Institute of Chemistry, University of São Paulo (USP), São Carlos, São Paulo, 13560-970, Brazil.
| | - Ricardo Leal Cunha
- Forensic Toxicology Laboratory, Scientific Police, São Cristóvão, Sergipe, 49100-000, Brazil
| | - Paulo Emílio Pereira Barci
- Laboratory of Chromatography (CROMA), São Carlos Institute of Chemistry, University of São Paulo (USP), São Carlos, São Paulo, 13560-970, Brazil
| | - Álvaro José Santos-Neto
- Laboratory of Chromatography (CROMA), São Carlos Institute of Chemistry, University of São Paulo (USP), São Carlos, São Paulo, 13560-970, Brazil
| | - Fernando Mauro Lanças
- Laboratory of Chromatography (CROMA), São Carlos Institute of Chemistry, University of São Paulo (USP), São Carlos, São Paulo, 13560-970, Brazil
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2
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Yang FM, Shen L, Fan DD, Chen KH, Lee J. DMGV Is a Rheostat of T Cell Survival and a Potential Therapeutic for Inflammatory Diseases and Cancers. Front Immunol 2022; 13:918241. [PMID: 35990633 PMCID: PMC9389583 DOI: 10.3389/fimmu.2022.918241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 06/13/2022] [Indexed: 11/13/2022] Open
Abstract
Activated effector T cells (Teff) and/or compromised regulatory T cells (Treg) underlie many chronic inflammatory diseases. We discovered a novel pathway to regulate survival and expansion of Teff without compromising Treg survival and a potential therapeutic to treat these diseases. We found dimethylguanidino valeric acid (DMGV) as a rheostat for Teff survival: while cell-intrinsic DMGV generated by Alanine-Glyoxylate Aminotransferase 2 (AGXT2) is essential for survival and expansion by inducing mitochondrial ROS and regulation of glycolysis, an excessive (or exogenous) DMGV level inhibits activated Teff survival, thereby the AGXT2-DMGV-ROS axis functioning as a switch to turn on and off Teff expansion. DMGV-induced ROS is essential for glycolysis in Teff, and paradoxically DMGV induces ROS only when glycolysis is active. Mechanistically, DMGV rapidly activates mitochondrial calcium uniporter (MCU), causing a surge in mitochondrial Ca2+ without provoking calcium influx to the cytosol. The mitochondrial Ca2+ surge in turn triggers the mitochondrial Na+/Ca2+ exchanger (NCLX) and the subsequent mitochondrial Na+ import induces ROS by uncoupling the Coenzyme Q cycle in Complex III of the electron transport chain. In preclinical studies, DMGV administration significantly diminished the number of inflammatory T cells, effectively suppressing chronic inflammation in mouse models of colitis and rheumatoid arthritis. DMGV also suppressed expansion of cancer cells in vitro and in a mouse T cell leukemic model by the same mechanism. Our data provide a new pathway regulating T cell survival and a novel mode to treat autoimmune diseases and cancers.
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Affiliation(s)
- Fengyuan Mandy Yang
- School of Basic Medical Sciences, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, and the State Key Laboratory of Respiratory Diseases, Guangzhou Medical University, Guangzhou, China
| | - Liya Shen
- School of Basic Medical Sciences, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, and the State Key Laboratory of Respiratory Diseases, Guangzhou Medical University, Guangzhou, China
| | - Dengxia Denise Fan
- School of Basic Medical Sciences, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, and the State Key Laboratory of Respiratory Diseases, Guangzhou Medical University, Guangzhou, China
| | - Kuan-Hung Chen
- Department of Orthopedics, The 1st Affiliated Hospital of Sun Yat-sen University, Guangdong, China
| | - Jongdae Lee
- School of Basic Medical Sciences, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, and the State Key Laboratory of Respiratory Diseases, Guangzhou Medical University, Guangzhou, China
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3
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Overexpression of alanine-glyoxylate aminotransferase 2 protects from asymmetric dimethylarginine-induced endothelial dysfunction and aortic remodeling. Sci Rep 2022; 12:9381. [PMID: 35672381 PMCID: PMC9174227 DOI: 10.1038/s41598-022-13169-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 05/20/2022] [Indexed: 12/03/2022] Open
Abstract
Elevated plasma concentrations of asymmetric dimethylarginine (ADMA) are associated with an increased risk of mortality and adverse cardiovascular outcomes. ADMA can be metabolized by dimethylarginine dimethylaminohydrolases (DDAHs) and by alanine-glyoxylate aminotransferase 2 (AGXT2). Deletion of DDAH1 in mice leads to elevation of ADMA in plasma and increase in blood pressure, while overexpression of human DDAH1 is associated with a lower plasma ADMA concentration and protective cardiovascular effects. The possible role of alternative metabolism of ADMA by AGXT2 remains to be elucidated. The goal of the current study was to test the hypothesis that transgenic overexpression of AGXT2 leads to lowering of plasma levels of ADMA and protection from vascular damage in the setting of DDAH1 deficiency. We generated transgenic mice (TG) with ubiquitous overexpression of AGXT2. qPCR and Western Blot confirmed the expression of the transgene. Systemic ADMA levels were decreased by 15% in TG mice. In comparison with wild type animals plasma levels of asymmetric dimethylguanidino valeric acid (ADGV), the AGXT2 associated metabolite of ADMA, were six times higher. We crossed AGXT2 TG mice with DDAH1 knockout mice and observed that upregulation of AGXT2 lowers plasma ADMA and pulse pressure and protects the mice from endothelial dysfunction and adverse aortic remodeling. Upregulation of AGXT2 led to lowering of ADMA levels and protection from ADMA-induced vascular damage in the setting of DDAH1 deficiency. This is especially important, because all the efforts to develop pharmacological ADMA-lowering interventions by means of upregulation of DDAHs have been unsuccessful.
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4
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Bonnitcha P, Sullivan D, Fitzpatrick M, Ireland A, Nguyen VL, Koay YC, O'Sullivan J. Design and validation of an LC-MS/MS method for simultaneous quantification of asymmetric dimethylguanidino valeric acid, asymmetric dimethylarginine and symmetric dimethylarginine in human plasma. Pathology 2022; 54:591-598. [DOI: 10.1016/j.pathol.2022.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 01/11/2022] [Accepted: 01/20/2022] [Indexed: 10/18/2022]
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5
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Kopaliani I, Jarzebska N, Billoff S, Kolouschek A, Martens-Lobenhoffer J, Bornstein SR, Bode-Böger SM, Ragavan VN, Weiss N, Mangoni AA, Deussen A, Rodionov RN. Overexpression of dimethylarginine dimethylaminohydrolase 1 protects from angiotensin II-induced cardiac hypertrophy and vascular remodeling. Am J Physiol Heart Circ Physiol 2021; 321:H825-H838. [PMID: 34533401 DOI: 10.1152/ajpheart.00064.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 09/01/2021] [Indexed: 11/22/2022]
Abstract
Cardiovascular complications are the leading cause of death, and elevated levels of asymmetric dimethyarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, are implicated in their pathophysiology. We investigated the role of dimethylarginine dimethylaminohydrolase 1 (DDAH1), an enzyme hydrolyzing ADMA, in prevention of cardiovascular remodeling during hypertension. We hypothesized that the animals overexpressing DDAH1 will be protected from angiotensin II (ANG II)-induced end organ damage. Angiotensin II (ANG II) was infused in two doses: 0.75 and 1.5 mg/kg/day in DDAH1 transgenic mice (DDAH1 TG) and wild-type (WT) littermates for 2 or 4 wk. Echocardiography was performed in the first and fourth weeks of the infusion, systolic blood pressure (SBP) was measured weekly, and cardiac hypertrophy and vascular remodeling was assessed by histology. Increase in SBP after 1 wk of ANG II infusion was not different between the groups, whereas TG mice had lower SBP at later time points. TG mice were protected from cardiovascular remodeling after 2 wk of ANG II infusion in the high dose and after 4 wk in the moderate dose. TG mice had higher left ventricular lumen-to-wall ratio, lower cardiomyocyte cross-sectional area, and less interstitial fibrosis compared with WT controls. In aorta, TG mice had less adventitial fibrosis, lower medial thickness with preserved elastin content, lower counts of inflammatory cells, lower levels of active matrix metalloproteinase-2, and showed better endothelium-dependent relaxation. We demonstrated that overexpression of DDAH1 protects from ANG II-induced cardiovascular remodeling and progression of hypertension by preserving endothelial function and limiting inflammation.NEW & NOTEWORTHY We showed that overexpression of dimethylarginine dimethylaminohydrolase 1 (DDAH1) protects from angiotensin II-induced cardiovascular damage, progression of hypertension, and adverse vascular remodeling in vivo. This protective effect is associated with decreased levels of asymmetric dimethylarginine, preservation of endothelial function, inhibition of cardiovascular inflammation, and lower activity of matrix metalloproteinase-2. Our findings are highly clinically relevant, because they suggest that upregulation of DDAH1 might be a promising therapeutic approach against angiotensin II-induced end organ damage.
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Affiliation(s)
- Irakli Kopaliani
- Department of Physiology, Medical Faculty, Dresden University of Technology, Dresden, Germany
| | - Natalia Jarzebska
- University Center for Vascular Medicine, Dresden University of Technology, Dresden, Germany
- Department of Anesthesiology and Critical Care Medicine, University Hospital Dresden, Dresden University of Technology, Dresden, Germany
- Department of Internal Medicine III, University Hospital Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
| | - Silke Billoff
- University Center for Vascular Medicine, Dresden University of Technology, Dresden, Germany
| | - Anne Kolouschek
- University Center for Vascular Medicine, Dresden University of Technology, Dresden, Germany
| | | | - Stefan R Bornstein
- University Clinic and Polyclinic III, Dresden University of Technology, Dresden, Germany
| | - Stefanie M Bode-Böger
- Institute of Clinical Pharmacology, Otto-von-Guericke University, Magdeburg, Germany
| | - Vinitha N Ragavan
- University Center for Vascular Medicine, Dresden University of Technology, Dresden, Germany
- Department of Clinical Pharmacology, College of Medicine and Public Health, Flinders University and Flinders Medical Centre, Adelaide, South Australia, Australia
| | - Norbert Weiss
- University Center for Vascular Medicine, Dresden University of Technology, Dresden, Germany
- University Clinic and Polyclinic III, Dresden University of Technology, Dresden, Germany
| | - Arduino A Mangoni
- Department of Clinical Pharmacology, College of Medicine and Public Health, Flinders University and Flinders Medical Centre, Adelaide, South Australia, Australia
| | - Andreas Deussen
- Department of Physiology, Medical Faculty, Dresden University of Technology, Dresden, Germany
| | - Roman N Rodionov
- University Center for Vascular Medicine, Dresden University of Technology, Dresden, Germany
- University Clinic and Polyclinic III, Dresden University of Technology, Dresden, Germany
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6
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Barton M, Cardillo C. Exercise is medicine: key to cardiovascular disease and diabetes prevention. Cardiovasc Res 2021; 117:360-363. [PMID: 32702117 DOI: 10.1093/cvr/cvaa226] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Affiliation(s)
- Matthias Barton
- University of Zürich, Molecular Internal Medicine, Y44 G22, Winterthurerstrasse 190, 8057 Zürich, Switzerland.,Andreas Grüntzig Foundation, Zürich, Switzerland
| | - Carmine Cardillo
- Internal Medicine, Policlinico A. Gemelli IRCCS, Università Cattolica del Sacro Cuore, Largo Vito 1, 00168 Roma, Italy.,Internal Medicine, Università Cattolica del Sacro Cuore, Largo Vito 1, 00168 Roma, Italy
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7
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Bollenbach A, Huneau JF, Mariotti F, Tsikas D. Asymmetric and Symmetric Protein Arginine Dimethylation: Concept and Postprandial Effects of High-Fat Protein Meals in Healthy Overweight Men. Nutrients 2019; 11:nu11071463. [PMID: 31252632 PMCID: PMC6683311 DOI: 10.3390/nu11071463] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 06/17/2019] [Accepted: 06/24/2019] [Indexed: 02/07/2023] Open
Abstract
Asymmetric and symmetric dimethylarginine (ADMA and SDMA, respectively) are risk factors for the cardiovascular and renal systems. There is a paucity of data in humans regarding variations of protein L-arginine (Arg) methylation leading to ADMA and SDMA. In this study, we introduced and used Arg dimethylation indices based on the creatinine-corrected urinary excretion of SDMA and ADMA, and its major metabolite dimethylamine (DMA). The main objective of the present study was to assess whether, and to which extent, a high-fat protein meal (HFM), a classical allostatic load eliciting various adverse effects, may contribute to Arg dimethylation in proteins in humans. Reliable gas chromatography-mass spectrometry methods were used to measure the concentration of ADMA, DMA, SDMA, and creatinine in spot urine samples collected before (0 h), and after (2, 4, 6 h) three HFM sessions in 10 healthy overweight individuals. At baseline, urinary ADMA, DMA, and SDMA excretion correlated positively with circulating TNF-α and IL-6. Arg dimethylation indices did not change postprandially. Our study shows that three HFMs do not contribute to Arg dimethylation in proteins. The proposed indices should be useful to determine extent and status of the whole-body Arg dimethylation in proteins in humans under various conditions.
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Affiliation(s)
- Alexander Bollenbach
- Institute of Toxicology, Core Unit Proteomics, Hannover Medical School, 30623 Hannover, Germany
| | | | - François Mariotti
- UMR PNCA, AgroParisTech, INRA, Université Paris-Saclay, 75005 Paris, France
| | - Dimitrios Tsikas
- Institute of Toxicology, Core Unit Proteomics, Hannover Medical School, 30623 Hannover, Germany.
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8
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Said MY, Douwes RM, van Londen M, Minović I, Frenay AR, de Borst MH, van den Berg E, Heiner-Fokkema MR, Kayacelebi AA, Bollenbach A, van Goor H, Navis G, Tsikas D, Bakker SJL. Effect of renal function on homeostasis of asymmetric dimethylarginine (ADMA): studies in donors and recipients of renal transplants. Amino Acids 2019; 51:565-575. [DOI: 10.1007/s00726-018-02693-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 12/22/2018] [Indexed: 11/29/2022]
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9
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L-Homoarginine and its AGXT2-metabolite GOCA in chronic kidney disease as markers for clinical status and prognosis. Amino Acids 2018; 50:1347-1356. [PMID: 29982953 DOI: 10.1007/s00726-018-2610-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 06/27/2018] [Indexed: 02/07/2023]
Abstract
Plasma concentrations of L-homoarginine (hArg) are an emerging marker for clinical status and prognosis in renal and cardiovascular disease. Lowered hArg concentrations are associated with higher risk for these conditions, although a clear pathophysiological explanation for this association has not been established. Baseline plasma samples of patients with different stages of chronic kidney disease (CKD) (n = 527) were obtained from the CARE FOR HOMe study and were analyzed for hArg and, for the first time, its metabolite 6-guanidino-2-oxocaproic acid (GOCA) by isotope dilution LC-MS/MS methods. GOCA is converted from hArg by the enzyme alanine:glyoxylate aminotransferase 2 (AGXT2), which is also in the focus of current cardiovascular research. hArg levels ranged from 0.20-4.01 µmol/L with a median of 1.42 µmol/L, whereas GOCA levels were 0.08-25.82 nmol/L with a median of 1.45 nmol/L. hArg levels in the highest tertile (≥ 1.71 µmol/L) were associated with significantly lower risk for reaching the renal (hazard ratio 0.369, 95% confidence interval 0.028-0.655) or cardiovascular (HR 0.458, CI 0.295-0.712) endpoints in univariate Cox regression analysis. Inversely, GOCA levels in the highest tertile (≥ 2.13 nmol/L) were associated with increased renal (HR 3.807, CI 1.963-7.381) and cardiovascular (HR 1.611, CI 1.041-2.495) risk. A decreased ratio between hArg and GOCA predicted even more pronounced the risks for renal (HR 0.178, CI 0.087-0.363) and cardiovascular (HR 0.447, CI 0.281-0.709) events. However, adjustment for the confounders eGFR and albuminuria attenuated these findings. A pathophysiological role of an increased activity of AGXT2 in CKD should be evaluated in future clinical studies.
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10
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O'Sullivan JF, Morningstar JE, Yang Q, Zheng B, Gao Y, Jeanfavre S, Scott J, Fernandez C, Zheng H, O'Connor S, Cohen P, Vasan RS, Long MT, Wilson JG, Melander O, Wang TJ, Fox C, Peterson RT, Clish CB, Corey KE, Gerszten RE. Dimethylguanidino valeric acid is a marker of liver fat and predicts diabetes. J Clin Invest 2017; 127:4394-4402. [PMID: 29083323 DOI: 10.1172/jci95995] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 09/21/2017] [Indexed: 01/11/2023] Open
Abstract
Unbiased, "nontargeted" metabolite profiling techniques hold considerable promise for biomarker and pathway discovery, in spite of the lack of successful applications to human disease. By integrating nontargeted metabolomics, genetics, and detailed human phenotyping, we identified dimethylguanidino valeric acid (DMGV) as an independent biomarker of CT-defined nonalcoholic fatty liver disease (NAFLD) in the offspring cohort of the Framingham Heart Study (FHS) participants. We verified the relationship between DMGV and early hepatic pathology. Specifically, plasma DMGV levels were correlated with biopsy-proven nonalcoholic steatohepatitis (NASH) in a hospital cohort of individuals undergoing gastric bypass surgery, and DMGV levels fell in parallel with improvements in post-procedure cardiometabolic parameters. Further, baseline DMGV levels independently predicted future diabetes up to 12 years before disease onset in 3 distinct human cohorts. Finally, we provide all metabolite peak data consisting of known and unidentified peaks, genetics, and key metabolic parameters as a publicly available resource for investigations in cardiometabolic diseases.
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Affiliation(s)
- John F O'Sullivan
- Cardiovascular Research Center, Division of Cardiology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Charles Perkins Centre and Heart Research Institute, The University of Sydney, Sydney, Australia
| | - Jordan E Morningstar
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Qiong Yang
- Framingham Heart Study of the National Heart, Lung, and Blood Institute and Boston University School of Medicine, Framingham, Massachusetts, USA.,Biostatistics Department, Boston University School of Public Health, Boston, Massachusetts, USA
| | - Baohui Zheng
- Cardiovascular Research Center, Division of Cardiology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Yan Gao
- University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Sarah Jeanfavre
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Justin Scott
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | | | - Hui Zheng
- Biostatistics Department, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Sean O'Connor
- The Rockefeller University, Laboratory of Molecular Metabolism, New York, New York, USA
| | - Paul Cohen
- The Rockefeller University, Laboratory of Molecular Metabolism, New York, New York, USA
| | - Ramachandran S Vasan
- Framingham Heart Study of the National Heart, Lung, and Blood Institute and Boston University School of Medicine, Framingham, Massachusetts, USA.,Cardiology Division, Boston Medical Center, and
| | - Michelle T Long
- Gastroenterology Division, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts, USA
| | - James G Wilson
- University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Olle Melander
- Department of Clinical Sciences, Lund University, Malmö, Sweden.,Center of Emergency Medicine, Skåne University Hospital, Malmö, Sweden
| | - Thomas J Wang
- Cardiology Division, Vanderbilt University, Nashville, Tennessee, USA
| | - Caroline Fox
- Framingham Heart Study of the National Heart, Lung, and Blood Institute and Boston University School of Medicine, Framingham, Massachusetts, USA
| | - Randall T Peterson
- Cardiovascular Research Center, Division of Cardiology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Clary B Clish
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Kathleen E Corey
- Gastroenterology Division, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Robert E Gerszten
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.,Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
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11
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Asymmetric Dimethylarginine and Hepatic Encephalopathy: Cause, Effect or Association? Neurochem Res 2016; 42:750-761. [PMID: 27885576 PMCID: PMC5357500 DOI: 10.1007/s11064-016-2111-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 09/07/2016] [Accepted: 11/15/2016] [Indexed: 12/11/2022]
Abstract
The methylated derivative of l-arginine, asymmetric dimethylarginine (ADMA) is synthesized in different mammalian tissues including the brain. ADMA acts as an endogenous, nonselective, competitive inhibitor of all three isoforms of nitric oxide synthase (NOS) and may limit l-arginine supply from the plasma to the enzyme via reducing its transport by cationic amino acid transporters. Hepatic encephalopathy (HE) is a relatively frequently diagnosed complex neuropsychiatric syndrome associated with acute or chronic liver failure, characterized by symptoms linked with impaired brain function leading to neurological disabilities. The l-arginine—nitric oxide (NO) pathway is crucially involved in the pathomechanism of HE via modulating important cerebral processes that are thought to contribute to the major HE symptoms. Specifically, activation of this pathway in acute HE leads to an increase in NO production and free radical formation, thus, contributing to astrocytic swelling and cerebral edema. Moreover, the NO-cGMP pathway seems to be involved in cerebral blood flow (CBF) regulation, altered in HE. For this reason, depressed NO-cGMP signaling accompanying chronic HE and ensuing cGMP deficit contributes to the cognitive and motor failure. However, it should be remembered that ADMA, a relatively little known element limiting NO synthesis in HE, may also influence the NO-cGMP pathway regulation. In this review, we will discuss the contribution of ADMA to the regulation of the NO-cGMP pathway in the brain, correlation of ADMA level with CBF and cognitive alterations observed during HE progression in patients and/or animal models of HE.
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12
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Burdin DV, Kolobov AA, Brocker C, Soshnev AA, Samusik N, Demyanov AV, Brilloff S, Jarzebska N, Martens-Lobenhoffer J, Mieth M, Maas R, Bornstein SR, Bode-Böger SM, Gonzalez F, Weiss N, Rodionov RN. Diabetes-linked transcription factor HNF4α regulates metabolism of endogenous methylarginines and β-aminoisobutyric acid by controlling expression of alanine-glyoxylate aminotransferase 2. Sci Rep 2016; 6:35503. [PMID: 27752141 PMCID: PMC5067591 DOI: 10.1038/srep35503] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 09/30/2016] [Indexed: 02/07/2023] Open
Abstract
Elevated levels of circulating asymmetric and symmetric dimethylarginines (ADMA and SDMA) predict and potentially contribute to end organ damage in cardiovascular diseases. Alanine-glyoxylate aminotransferase 2 (AGXT2) regulates systemic levels of ADMA and SDMA, and also of beta-aminoisobutyric acid (BAIB)-a modulator of lipid metabolism. We identified a putative binding site for hepatic nuclear factor 4 α (HNF4α) in AGXT2 promoter sequence. In a luciferase reporter assay we found a 75% decrease in activity of Agxt2 core promoter after disruption of the HNF4α binding site. Direct binding of HNF4α to Agxt2 promoter was confirmed by chromatin immunoprecipitation assay. siRNA-mediated knockdown of Hnf4a led to an almost 50% reduction in Agxt2 mRNA levels in Hepa 1–6 cells. Liver-specific Hnf4a knockout mice exhibited a 90% decrease in liver Agxt2 expression and activity, and elevated plasma levels of ADMA, SDMA and BAIB, compared to wild-type littermates. Thus we identified HNF4α as a major regulator of Agxt2 expression. Considering a strong association between human HNF4A polymorphisms and increased risk of type 2 diabetes our current findings suggest that downregulation of AGXT2 and subsequent impairment in metabolism of dimethylarginines and BAIB caused by HNF4α deficiency might contribute to development of cardiovascular complications in diabetic patients.
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Affiliation(s)
- Dmitry V Burdin
- Department of Physiology, Saint Petersburg State University, 199034 Saint Petersburg, Russia
| | - Alexey A Kolobov
- Department of Biochemistry, Saint Petersburg State University, 199034 Saint Petersburg, Russia
| | - Chad Brocker
- National Cancer Institute, NIH, Bethesda, MD, 20892, USA
| | | | - Nikolay Samusik
- Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Anton V Demyanov
- Institute of Highly Pure Biopreparations, 197110 Saint Petersburg, Russia
| | - Silke Brilloff
- University Center for Vascular Medicine, Technische Universität Dresden, 01307 Dresden, Germany
| | - Natalia Jarzebska
- University Center for Vascular Medicine, Technische Universität Dresden, 01307 Dresden, Germany
| | | | - Maren Mieth
- Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Renke Maas
- Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Stefan R Bornstein
- Department of Internal Medicine III, University Hospital Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany
| | - Stefanie M Bode-Böger
- Institute of Clinical Pharmacology, Otto-von-Guericke University, 39120 Magdeburg, Germany
| | - Frank Gonzalez
- National Cancer Institute, NIH, Bethesda, MD, 20892, USA
| | - Norbert Weiss
- University Center for Vascular Medicine, Technische Universität Dresden, 01307 Dresden, Germany
| | - Roman N Rodionov
- University Center for Vascular Medicine, Technische Universität Dresden, 01307 Dresden, Germany
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13
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A Novel Pathway for Metabolism of the Cardiovascular Risk Factor Homoarginine by alanine:glyoxylate aminotransferase 2. Sci Rep 2016; 6:35277. [PMID: 27752063 PMCID: PMC5082758 DOI: 10.1038/srep35277] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 09/23/2016] [Indexed: 01/06/2023] Open
Abstract
Low plasma concentrations of L-homoarginine are associated with an increased risk of cardiovascular events, while homoarginine supplementation is protective in animal models of metabolic syndrome and stroke. Catabolism of homoarginine is still poorly understood. Based on the recent findings from a Genome Wide Association Study we hypothesized that homoarginine can be metabolized by alanine:glyoxylate aminotransferase 2 (AGXT2). We purified human AGXT2 from tissues of AGXT2 transgenic mice and demonstrated its ability to metabolize homoarginine to 6-guanidino-2-oxocaproic acid (GOCA). After incubation of HepG2 cells overexpressing AGXT2 with isotope-labeled homoarginine-d4 we were able to detect labeled GOCA in the medium. We injected wild type mice with labeled homoarginine and detected labeled GOCA in the plasma. We found that AGXT2 knockout (KO) mice have higher homoarginine and lower GOCA plasma levels as compared to wild type mice, while the reverse was true for AGXT2 transgenic (Tg) mice. In summary, we experimentally proved the presence of a new pathway of homoarginine catabolism – its transamination by AGXT2 with formation of GOCA and demonstrated that endogenous AGXT2 is required for maintenance of homoarginine levels in mice. Our findings may lead to development of novel therapeutic approaches for cardiovascular pathologies associated with homoarginine deficiency.
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Amino acid N-acetylation: Metabolic elimination of symmetric dimethylarginine as symmetric Nα-acetyldimethylarginine, determined in human plasma and urine by LC–MS/MS. J Chromatogr B Analyt Technol Biomed Life Sci 2015; 975:59-64. [DOI: 10.1016/j.jchromb.2014.11.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 11/10/2014] [Accepted: 11/11/2014] [Indexed: 12/29/2022]
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Popolo A, Adesso S, Pinto A, Autore G, Marzocco S. L-Arginine and its metabolites in kidney and cardiovascular disease. Amino Acids 2014; 46:2271-86. [PMID: 25161088 DOI: 10.1007/s00726-014-1825-9] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 08/13/2014] [Indexed: 12/19/2022]
Abstract
L-Arginine is a semi essential amino acid synthesised from glutamine, glutamate and proline via the intestinal-renal axis in humans and most mammals. L-Arginine degradation occurs via multiple pathways initiated by arginase, nitric-oxide synthase, Arg: glycine amidinotransferase, and Arg decarboxylase. These pathways produce nitric oxide, polyamines, proline, glutamate, creatine and agmatine with each having enormous biological importance. Several disease are associated to an L-arginine impaired levels and/or to its metabolites: in particular various L-arginine metabolites may participate in pathogenesis of kidney and cardiovascular disease. L-Arginine and its metabolites may constitute both a marker of pathology progression both the rationale for manipulating L-arginine metabolism as a strategy to ameliorate these disease. A large number of studies have been performed in experimental models of kidney disease with sometimes conflicting results, which underlie the complexity of Arg metabolism and our incomplete knowledge of all the mechanisms involved. Moreover several lines of evidence demonstrate the role of L-arg metabolites in cardiovascular disease and that L-arg administration role in reversing endothelial dysfunction, which is the leading cause of cardiovascular diseases, such as hypertension and atherosclerosis. This review will discuss the implication of the mains L-arginine metabolites and L-arginine-derived guanidine compounds in kidney and cardiovascular disease considering the more recent literature in the field.
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Affiliation(s)
- Ada Popolo
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II 132, 84084, Fisciano, SA, Italy
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Rodionov RN, Martens-Lobenhoffer J, Brilloff S, Hohenstein B, Jarzebska N, Jabs N, Kittel A, Maas R, Weiss N, Bode-Böger SM. Role of alanine:glyoxylate aminotransferase 2 in metabolism of asymmetric dimethylarginine in the settings of asymmetric dimethylarginine overload and bilateral nephrectomy. Nephrol Dial Transplant 2014; 29:2035-42. [PMID: 25002409 DOI: 10.1093/ndt/gfu236] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Asymmetric and symmetric dimethylarginines (ADMA and SDMA) predict complications and mortality in cardiovascular and renal diseases. Alanine:glyoxylate aminotransferase 2 (AGXT2) can metabolize both ADMA and SDMA; however, this metabolic pathway is still poorly understood. The goal of our study was to test the hypothesis that AGXT2 is compensatory upregulated in the settings of ADMA overload and bilateral nephrectomy. METHODS ADMA was infused for 3 days using osmotic minipumps in mice. Half of the mice underwent bilateral nephrectomy 24 h before the end of the infusion. RESULTS Infusion of ADMA caused a 3- to 4-fold increase in plasma and urine ADMA levels and a 2- to 3-fold increase in plasma and urine levels of the ADMA-specific metabolite of AGXT2 α-keto-δ-(N,N-dimethylguanidino)valeric acid (DMGV). Bilateral nephrectomy led to an ∼4-fold increase of plasma SDMA levels, but did not change plasma ADMA levels. Interestingly, plasma levels of DMGV were elevated 32-fold in the mice, which underwent bilateral nephrectomy. Neither bilateral nephrectomy nor ADMA infusion caused upregulation of AGXT2 expression or activity. CONCLUSIONS Our data demonstrate that short-term elevation of systemic levels of ADMA leads to a dramatic increase of DMGV formation without upregulation of AGXT2 expression or activity, which suggests that AGXT2-mediated pathway of ADMA metabolism is not saturated under normal conditions and may play a major role in the maintenance of ADMA homeostasis in the setting of local or systemic elevation of ADMA levels.
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Affiliation(s)
- Roman N Rodionov
- University Center for Vascular Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | | | - Silke Brilloff
- University Center for Vascular Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Bernd Hohenstein
- Division of Nephrology, Department of Internal Medicine III, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Natalia Jarzebska
- Department of Internal Medicine III, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Normund Jabs
- University Center for Vascular Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Anja Kittel
- Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Renke Maas
- Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Norbert Weiss
- University Center for Vascular Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Stefanie M Bode-Böger
- Institute of Clinical Pharmacology, Otto-von-Guericke University, Magdeburg, Germany
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Abe M, Ochi S, Mori Y, Yamazaki K, Ishimaru T, Yoshino Y, Fukuhara R, Tanimukai S, Matsuda S, Ueno SI. Distribution of D-3-aminoisobutyrate-pyruvate aminotransferase in the rat brain. BMC Neurosci 2014; 15:53. [PMID: 24766736 PMCID: PMC4030283 DOI: 10.1186/1471-2202-15-53] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 04/04/2014] [Indexed: 11/10/2022] Open
Abstract
Background D-3-aminoisobutyrate, an intermediary product of thymine, is converted to 2-methyl-3-oxopropanoate using pyruvate as an amino acceptor by D-3-aminoisobutyrate-pyruvate aminotransferase (D-AIB AT; EC 2.6.1.40). A large amount of D-AIB AT is distributed in the kidney and liver; however, small amounts are found in the brain. Recently, D-AIB AT was reported to metabolize asymmetric dimethylarginine (ADMA) in vivo and was suggested to be an important enzyme for nitric oxide metabolism because ADMA is a competitive inhibitor for nitric oxide synthase. In this study, we examined the distribution of D-AIB AT in the rat brain further to understand its role. We measured D-AIB AT mRNA and protein expression using quantitative RT-PCR and Western blotting, and monitored its distribution using immunohistochemical staining. Results D-AIB AT was distributed throughout the brain, with high expression in the cortex and hippocampus. Immunohistochemical staining revealed that D-AIB AT was highly expressed in the retrosplenial cortex and in hippocampal neurons. Conclusion Our results suggest that D-AIB AT is distributed in the examined- just the regions and may play an important role there.
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Affiliation(s)
- Masao Abe
- Department of Neuropsychiatry, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan.
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Martens-Lobenhoffer J, Rodionov RN, Bode-Böger SM. Determination of asymmetric Nα-acetyldimethylarginine in humans: a phase II metabolite of asymmetric dimethylarginine. Anal Biochem 2014; 452:25-30. [PMID: 24560726 DOI: 10.1016/j.ab.2014.02.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 01/28/2014] [Accepted: 02/11/2014] [Indexed: 11/25/2022]
Abstract
Asymmetric dimethylarginine (ADMA) is produced by protein methylation, a common mechanism of posttranslational protein modification. Elevated levels of ADMA lead to impaired endothelial nitric oxide production and subsequently to a range of cardiovascular and other diseases related to decreased nitric oxide production. Knowledge of the elimination pathways of ADMA and the possibility of influencing them is therefore of major clinical interest. One of these pathways is the N-acetylation and subsequent renal elimination of ADMA in the form of asymmetric Nα-acetyldimethylarginine (Ac-ADMA). In this work, we describe the first method to quantitatively determine Ac-ADMA in human plasma and urine. Ac-ADMA was separated by HPLC on a porous graphitic carbon column and selectively analyzed by tandem mass spectrometry. Ac-ADMA and the internal standard D7-Ac-ADMA were synthesized in-house. Precision and accuracy of the method were better than 5% in plasma and urine quality control samples. First results obtained with this method in samples of healthy volunteers showed plasma levels of 0.643±0.454 nmol/L and urine levels of 152.7±76.7 nmol/L or 13.0±8.9 nmol/mmol creatinine. The method is a suitable tool for investigating this currently mostly neglected ADMA elimination pathway.
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Affiliation(s)
| | - Roman N Rodionov
- University Center for Vascular Medicine, University Hospital Carl Gustav Carus, Technical University, Dresden, Germany
| | - Stefanie M Bode-Böger
- Institute of Clinical Pharmacology, Otto-von-Guericke University, 39120 Magdeburg, Germany
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Schepers E, Speer T, Bode-Böger SM, Fliser D, Kielstein JT. Dimethylarginines ADMA and SDMA: the real water-soluble small toxins? Semin Nephrol 2014; 34:97-105. [PMID: 24780466 DOI: 10.1016/j.semnephrol.2014.02.003] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Uremia occurs if the kidney loses the ability to eliminate toxic compounds at a sufficient rate into the urine. In 1970, N-N, N-G- and N-G,N׳-G-dimethyl-arginine (asymmetric dimethylarginine [ADMA] and symmetric dimethylarginine) were isolated from human urine. It was anticipated that both substances might be important in the pathophysiology and for the diagnosis of various pathologic states. It took 22 years, however, before this idea materialized when it was found that ADMA, which is increased in hemodialysis patients, inhibits the synthesis of the endothelial-derived relaxing factor, identified as nitric oxide. ADMA correlates with traditional and nontraditional cardiovascular risk factors and is a strong predictor of cardiovascular events and death in both patients with chronic kidney disease and in the general population. It also seems to mediate adverse cardiovascular effects of drugs such as proton pump inhibitors. To date, we have no specific pharmacologic therapy at hand to neutralize the deleterious effects of ADMA, curbing the enthusiasm for this marker and mediator of cardiovascular disease.
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Affiliation(s)
| | - Timo Speer
- Department of Internal Medicine IV, Renal and Hypertensive Disease, Saarland University, Medical Centre, Homburg/Saar, Germany
| | - Stefanie M Bode-Böger
- Institute of Clinical Pharmacology, Otto von-Guericke University, Magdeburg, Germany
| | - Danilo Fliser
- Department of Internal Medicine IV, Renal and Hypertensive Disease, Saarland University, Medical Centre, Homburg/Saar, Germany
| | - Jan T Kielstein
- Department of Nephrology and Hypertension, Medical School Hannover, Germany.
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Martens-Lobenhoffer J, Bode-Böger SM. Mass spectrometric quantification of L-arginine and its pathway related substances in biofluids: the road to maturity. J Chromatogr B Analyt Technol Biomed Life Sci 2013; 964:89-102. [PMID: 24210895 DOI: 10.1016/j.jchromb.2013.10.030] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 10/17/2013] [Accepted: 10/19/2013] [Indexed: 11/18/2022]
Abstract
The amino acid L-arginine together with its metabolites and related substances is in the center of many biologically important pathways, especially the urea cycle and the nitric oxide (NO) synthesis. Therefore, the concentrations of these substances in various biological fluids are of great interest as predictive markers for health and disease. Yet, they provide major analytical difficulties as they are very polar in nature and therefore not easily to be separated on standard reversed phase HPLC stationary phases. Furthermore, as endogenous substances, no analyte-free matrix is available, a fact that results in complicated calibration procedures. This review evaluates the analytical literature for the determination of L-arginine, symmetric dimethylarginine, asymmetric dimethylarginine, monomethylarginine, L-citrulline, L-ornithine, L-homoarginine, agmatine and dimethylguanidinovaleric acid in biological fluids. Papers are discussed, which were published since 2007 and describe methods applying capillary electrophoresis (CE), gas chromatography (GC), reversed phase HPLC or polar phase HPLC, coupled to mass spectrometric quantification. Nowadays, many carefully developed and validated methods for L-arginine and its related substances are available to the scientific community. The use of stable isotope labeled internal standards enables high precision and accuracy in mass spectrometry-based quantitative analysis.
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Affiliation(s)
| | - Stefanie M Bode-Böger
- Institute of Clinical Pharmacology, Otto-von-Guericke University, Magdeburg, Germany
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Seppälä I, Kleber ME, Lyytikäinen LP, Hernesniemi JA, Mäkelä KM, Oksala N, Laaksonen R, Pilz S, Tomaschitz A, Silbernagel G, Boehm BO, Grammer TB, Koskinen T, Juonala M, Hutri-Kähönen N, Alfthan G, Viikari JSA, Kähonen M, Raitakari OT, März W, Meinitzer A, Lehtimäki T. Genome-wide association study on dimethylarginines reveals novel AGXT2 variants associated with heart rate variability but not with overall mortality. Eur Heart J 2013; 35:524-31. [PMID: 24159190 DOI: 10.1093/eurheartj/eht447] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
AIMS The purpose of this study was to identify novel genetic variants influencing circulating asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) levels and to evaluate whether they have a prognostic value on cardiovascular mortality. METHODS AND RESULTS We conducted a genome-wide association study on the methylarginine traits and investigated the predictive value of the new discovered variants on mortality. Our meta-analyses replicated the previously known locus for ADMA levels in DDAH1 (rs997251; P = 1.4 × 10(-40)), identified two non-synomyous polymorphisms for SDMA levels in AGXT2 (rs37369; P = 1.4 × 10(-40) and rs16899974; P = 1.5 × 10(-38)) and one in SLC25A45 (rs34400381; P = 2.5 × 10(-10)). We also fine-mapped the AGXT2 locus for further independent association signals. The two non-synonymous AGXT2 variants independently associated with SDMA levels were also significantly related with short-term heart rate variability (HRV) indices in young adults. The major allele (C) of the novel non-synonymous rs16899974 (V498L) variant associated with decreased SDMA levels and an increase in the ratio between the low- and high-frequency spectral components of HRV (P = 0.00047). Furthermore, the SDMA decreasing allele (G) of the non-synomyous SLC25A45 (R285C) variant was associated with a lower resting mean heart rate during the HRV measurements (P = 0.0046), but not with the HRV indices. None of the studied genome-wide significant variants had any major effect on cardiovascular or total mortality in patients referred for coronary angiography. CONCLUSIONS AGXT2 has an important role in SDMA metabolism in humans. AGXT2 may additionally have an unanticipated role in the autonomic nervous system regulation of cardiac function.
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Affiliation(s)
- Ilkka Seppälä
- Department of Clinical Chemistry, Fimlab Laboratories, Tampere University School of Medicine, Finn-Medi 2, 3rd floor, PO Box 2000, Tampere FI-33521, Finland
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In vivo evidence that Agxt2 can regulate plasma levels of dimethylarginines in mice. Biochem Biophys Res Commun 2013; 430:84-9. [DOI: 10.1016/j.bbrc.2012.11.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 11/06/2012] [Indexed: 02/07/2023]
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Martens-Lobenhoffer J, Rodionov RN, Bode-Böger SM. Probing AGXT2 enzyme activity in mouse tissue by applying stable isotope-labeled asymmetric dimethyl arginine as substrate. JOURNAL OF MASS SPECTROMETRY : JMS 2012; 47:1594-1600. [PMID: 23280748 DOI: 10.1002/jms.3125] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 10/12/2012] [Accepted: 10/16/2012] [Indexed: 06/01/2023]
Abstract
Asymmetric dimethylarginine (ADMA) is a metabolite of the amino acid L-arginine. It competitively inhibits the enzymatic production of the cell-signaling substance nitric oxide. Therefore, increased levels of ADMA are associated with a range of cardiovascular and other diseases. ADMA is biologically eliminated by direct renal excretion and hydrolysis by the enzyme DDAH. Recently, a further elimination pathway via the transamination by the enzyme AGXT2 to α-keto-δ-(N(G),N(G)-dimethylguanidino)valeric acid (DMGV) has come into the focus of biological research. In this work, we describe an assay for the AGXT2 activity in mouse liver and kidney tissue. It is based on the transformation of isotope-labeled ADMA-d(6) to DMGV-d(6). The quantification of the DMGV-d(6) produced by this reaction in tissue homogenate samples was accomplished by chromatographic separation on a porous graphitic carbon column and tandem mass spectrometric detection. DMGV-d(6) with the deuterium labels in different molecular positions was used as internal standard. The overall production rates of DMGV-d(6) in mice were 195.37 pmol/min/mg total protein in liver and 85.21 pmol/min/mg total protein in kidney tissue, with coefficients of variation of 6.31% and 11.25%, respectively. This method can be applied as a tool for the characterization of the ADMA elimination by the AGXT2 pathway.
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Affiliation(s)
- Jens Martens-Lobenhoffer
- Institute of Clinical Pharmacology, Otto-von-Guericke University, Leipziger Str. 44, 39120, Magdeburg, Germany.
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Chen XM, Hu CP, Li YJ, Jiang JL. Cardiovascular risk in autoimmune disorders: role of asymmetric dimethylarginine. Eur J Pharmacol 2012; 696:5-11. [PMID: 23026371 DOI: 10.1016/j.ejphar.2012.09.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 09/04/2012] [Accepted: 09/17/2012] [Indexed: 02/08/2023]
Abstract
Mounting evidence indicates that cardiovascular events are a main cause of excessive mortality of autoimmune disorders like type I diabetes mellitus and rheumatic diseases. Inflammation and endothelial dysfunction, independent predictors to cardiovascular disease, are hallmarks of autoimmunity. Asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, can cause or contribute to the inflammatory syndrome and endothelial dysfunction. Recently, elevated ADMA levels have been demonstrated in many autoimmune diseases, suggesting that ADMA might play an important role for the associated manifestations of cardiovascular disease. In the review, we discuss the role of ADMA in the excessive cardiovascular morbidity and mortality associated with autoimmune diseases.
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Affiliation(s)
- Xu-Meng Chen
- Department of Pharmacology, School of Pharmaceutical Sciences, Central South University, Xiang-Ya Road #110, Changsha 410078, China
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Caplin B, Wang Z, Slaviero A, Tomlinson J, Dowsett L, Delahaye M, Salama A, Wheeler DC, Leiper J. Alanine-glyoxylate aminotransferase-2 metabolizes endogenous methylarginines, regulates NO, and controls blood pressure. Arterioscler Thromb Vasc Biol 2012; 32:2892-900. [PMID: 23023372 DOI: 10.1161/atvbaha.112.254078] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
OBJECTIVE Asymmetric dimethylarginine is an endogenous inhibitor of NO synthesis that may mediate cardiovascular disease. Alanine-glyoxylate aminotransferase-2 (AGXT2) has been proposed to degrade asymmetric dimethylarginine. We investigated the significance of AGXT2 in methylarginine metabolism in vivo and examined the effect of this enzyme on blood pressure. METHODS AND RESULTS In isolated mouse kidney mitochondria, we show asymmetric dimethylarginine deamination under physiological conditions. We demonstrate increased asymmetric dimethylarginine, reduced NO, and hypertension in an AGXT2 knockout mouse. We provide evidence for a role of AGXT2 in methylarginine metabolism in humans by demonstrating an inverse relationship between renal (allograft) gene expression and circulating substrate levels and an association between expression and urinary concentrations of the product. Finally, we examined data from a meta-analysis of blood pressure genome-wide association studies. No genome-wide significance was observed, but taking a hypothesis-driven approach, there was a suggestive association between the T allele at rs37369 (which causes a valine-isoleucine substitution and altered levels of AGXT2 substrate) and a modest increase in diastolic blood pressure (P=0.0052). CONCLUSIONS Although the effect of variation at rs37369 needs further study, these findings suggest that AGXT2 is an important regulator of methylarginines and represents a novel mechanism through which the kidney regulates blood pressure.
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Affiliation(s)
- Ben Caplin
- Nitric Oxide Signalling Group, Medical Research Council Clinical Sciences Center, Imperial College London, London, United Kingdom.
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