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Hao M, Qin Y, Li Y, Tang Y, Ma Z, Tan J, Jin L, Wang F, Gong X. Metabolome subtyping reveals multi-omics characteristics and biological heterogeneity in major psychiatric disorders. Psychiatry Res 2023; 330:115605. [PMID: 38006718 DOI: 10.1016/j.psychres.2023.115605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 11/02/2023] [Accepted: 11/10/2023] [Indexed: 11/27/2023]
Abstract
Growing evidence suggests that major psychiatric disorders (MPDs) share common etiologies and pathological processes. However, the diagnosis is currently based on descriptive symptoms, which ignores the underlying pathogenesis and hinders the development of clinical treatments. This highlights the urgency of characterizing molecular biomarkers and establishing objective diagnoses of MPDs. Here, we collected untargeted metabolomics, proteomics and DNA methylation data of 327 patients with MPDs, 131 individuals with genetic high risk and 146 healthy controls to explore the multi-omics characteristics of MPDs. First, differential metabolites (DMs) were identified and we classified MPD patients into 3 subtypes based on DMs. The subtypes showed distinct metabolomics, proteomics and DNA methylation signatures. Specifically, one subtype showed dysregulation of complement and coagulation proteins, while the DNA methylation showed abnormalities in chemical synapses and autophagy. Integrative analysis in metabolic pathways identified the important roles of the citrate cycle, sphingolipid metabolism and amino acid metabolism. Finally, we constructed prediction models based on the metabolites and proteomics that successfully captured the risks of MPD patients. Our study established molecular subtypes of MPDs and elucidated their biological heterogeneity through a multi-omics investigation. These results facilitate the understanding of pathological mechanisms and promote the diagnosis and prevention of MPDs.
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Affiliation(s)
- Meng Hao
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China; Zhangjiang Fudan International Innovation Center, Fudan Zhangjiang Institute, Obstetrics and Gynecology Hospital, Human Phenome Institute, Fudan University, China
| | - Yue Qin
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China; Zhangjiang Fudan International Innovation Center, Fudan Zhangjiang Institute, Obstetrics and Gynecology Hospital, Human Phenome Institute, Fudan University, China
| | - Yi Li
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China; Zhangjiang Fudan International Innovation Center, Fudan Zhangjiang Institute, Obstetrics and Gynecology Hospital, Human Phenome Institute, Fudan University, China; International Human Phenome Institutes, Shanghai, China
| | - Yanqing Tang
- Department of Psychiatry, The First Affiliated Hospital of China Medical University, Shenyang, China
| | - Zehan Ma
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Jingze Tan
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Li Jin
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China; Zhangjiang Fudan International Innovation Center, Fudan Zhangjiang Institute, Obstetrics and Gynecology Hospital, Human Phenome Institute, Fudan University, China; International Human Phenome Institutes, Shanghai, China
| | - Fei Wang
- Early Intervention Unit, Department of Psychiatry, Affiliated Nanjing Brain Hospital, Nanjing Medical University, Nanjing, China; Functional Brain Imaging Institute of Nanjing Medical University, Nanjing, China.
| | - Xiaohong Gong
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China.
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2
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Li VL, He Y, Contrepois K, Liu H, Kim JT, Wiggenhorn AL, Tanzo JT, Tung ASH, Lyu X, Zushin PJH, Jansen RS, Michael B, Loh KY, Yang AC, Carl CS, Voldstedlund CT, Wei W, Terrell SM, Moeller BC, Arthur RM, Wallis GA, van de Wetering K, Stahl A, Kiens B, Richter EA, Banik SM, Snyder MP, Xu Y, Long JZ. An exercise-inducible metabolite that suppresses feeding and obesity. Nature 2022; 606:785-790. [PMID: 35705806 PMCID: PMC9767481 DOI: 10.1038/s41586-022-04828-5] [Citation(s) in RCA: 99] [Impact Index Per Article: 49.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 05/03/2022] [Indexed: 01/12/2023]
Abstract
Exercise confers protection against obesity, type 2 diabetes and other cardiometabolic diseases1-5. However, the molecular and cellular mechanisms that mediate the metabolic benefits of physical activity remain unclear6. Here we show that exercise stimulates the production of N-lactoyl-phenylalanine (Lac-Phe), a blood-borne signalling metabolite that suppresses feeding and obesity. The biosynthesis of Lac-Phe from lactate and phenylalanine occurs in CNDP2+ cells, including macrophages, monocytes and other immune and epithelial cells localized to diverse organs. In diet-induced obese mice, pharmacological-mediated increases in Lac-Phe reduces food intake without affecting movement or energy expenditure. Chronic administration of Lac-Phe decreases adiposity and body weight and improves glucose homeostasis. Conversely, genetic ablation of Lac-Phe biosynthesis in mice increases food intake and obesity following exercise training. Last, large activity-inducible increases in circulating Lac-Phe are also observed in humans and racehorses, establishing this metabolite as a molecular effector associated with physical activity across multiple activity modalities and mammalian species. These data define a conserved exercise-inducible metabolite that controls food intake and influences systemic energy balance.
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Affiliation(s)
- Veronica L Li
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Chemistry, Stanford University, Stanford, CA, USA
- Sarafan ChEM-H, Stanford University, Stanford, CA, USA
- Wu Tsai Human Performance Alliance, Stanford University, Stanford, CA, USA
| | - Yang He
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Kévin Contrepois
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cardiovascular Institute, Stanford University, Stanford, CA, USA
- Stanford Diabetes Research Center, Stanford University, Stanford, CA, USA
| | - Hailan Liu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Joon T Kim
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
- Sarafan ChEM-H, Stanford University, Stanford, CA, USA
| | - Amanda L Wiggenhorn
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Chemistry, Stanford University, Stanford, CA, USA
- Sarafan ChEM-H, Stanford University, Stanford, CA, USA
| | - Julia T Tanzo
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
- Sarafan ChEM-H, Stanford University, Stanford, CA, USA
| | - Alan Sheng-Hwa Tung
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
- Sarafan ChEM-H, Stanford University, Stanford, CA, USA
| | - Xuchao Lyu
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
- Sarafan ChEM-H, Stanford University, Stanford, CA, USA
- Wu Tsai Human Performance Alliance, Stanford University, Stanford, CA, USA
| | - Peter-James H Zushin
- Department of Nutrition and Toxicology, University of California Berkeley, Berkeley, CA, USA
| | - Robert S Jansen
- Netherlands Cancer Institute, Amsterdam, Netherlands
- Department of Microbiology, Radboud University, Nijmegen, Netherlands
| | - Basil Michael
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Kang Yong Loh
- Department of Chemistry, Stanford University, Stanford, CA, USA
- Sarafan ChEM-H, Stanford University, Stanford, CA, USA
| | - Andrew C Yang
- Department of Anatomy and the Bakar Aging Research Institute, University of California San Francisco, San Francisco, CA, USA
| | - Christian S Carl
- August Krogh Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Christian T Voldstedlund
- August Krogh Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Wei Wei
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
- Sarafan ChEM-H, Stanford University, Stanford, CA, USA
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Stephanie M Terrell
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
- Sarafan ChEM-H, Stanford University, Stanford, CA, USA
| | - Benjamin C Moeller
- Maddy Equine Analytical Chemistry Laboratory, California Animal Health and Food Safety Laboratory, School of Veterinary Medicine, University of California at Davis, Davis, CA, USA
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Rick M Arthur
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Gareth A Wallis
- School of Sport, Exercise, and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Koen van de Wetering
- Netherlands Cancer Institute, Amsterdam, Netherlands
- Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Andreas Stahl
- Department of Nutrition and Toxicology, University of California Berkeley, Berkeley, CA, USA
| | - Bente Kiens
- August Krogh Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Erik A Richter
- August Krogh Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Steven M Banik
- Department of Chemistry, Stanford University, Stanford, CA, USA
- Sarafan ChEM-H, Stanford University, Stanford, CA, USA
| | - Michael P Snyder
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cardiovascular Institute, Stanford University, Stanford, CA, USA
- Stanford Diabetes Research Center, Stanford University, Stanford, CA, USA
- Wu Tsai Human Performance Alliance, Stanford University, Stanford, CA, USA
| | - Yong Xu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA.
| | - Jonathan Z Long
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA.
- Sarafan ChEM-H, Stanford University, Stanford, CA, USA.
- Stanford Cardiovascular Institute, Stanford University, Stanford, CA, USA.
- Stanford Diabetes Research Center, Stanford University, Stanford, CA, USA.
- Wu Tsai Human Performance Alliance, Stanford University, Stanford, CA, USA.
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Sharma R, Reinstadler B, Engelstad K, Skinner OS, Stackowitz E, Haller RG, Clish CB, Pierce K, Walker MA, Fryer R, Oglesbee D, Mao X, Shungu DC, Khatri A, Hirano M, De Vivo DC, Mootha VK. Circulating markers of NADH-reductive stress correlate with mitochondrial disease severity. J Clin Invest 2021; 131:136055. [PMID: 33463549 DOI: 10.1172/jci136055] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 11/18/2020] [Indexed: 12/16/2022] Open
Abstract
Mitochondrial disorders represent a large collection of rare syndromes that are difficult to manage both because we do not fully understand biochemical pathogenesis and because we currently lack facile markers of severity. The m.3243A>G variant is the most common heteroplasmic mitochondrial DNA mutation and underlies a spectrum of diseases, notably mitochondrial encephalomyopathy lactic acidosis and stroke-like episodes (MELAS). To identify robust circulating markers of m.3243A>G disease, we first performed discovery proteomics, targeted metabolomics, and untargeted metabolomics on plasma from a deeply phenotyped cohort (102 patients, 32 controls). In a validation phase, we measured concentrations of prioritized metabolites in an independent cohort using distinct methods. We validated 20 analytes (1 protein, 19 metabolites) that distinguish patients with MELAS from controls. The collection includes classic (lactate, alanine) and more recently identified (GDF-15, α-hydroxybutyrate) mitochondrial markers. By mining untargeted mass-spectra we uncovered 3 less well-studied metabolite families: N-lactoyl-amino acids, β-hydroxy acylcarnitines, and β-hydroxy fatty acids. Many of these 20 analytes correlate strongly with established measures of severity, including Karnofsky status, and mechanistically, nearly all markers are attributable to an elevated NADH/NAD+ ratio, or NADH-reductive stress. Our work defines a panel of organelle function tests related to NADH-reductive stress that should enable classification and monitoring of mitochondrial disease.
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Affiliation(s)
- Rohit Sharma
- Howard Hughes Medical Institute, Department of Molecular Biology, and.,Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA.,Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, USA.,Broad Institute, Cambridge, Massachusetts, USA
| | - Bryn Reinstadler
- Howard Hughes Medical Institute, Department of Molecular Biology, and.,Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA.,Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, USA.,Broad Institute, Cambridge, Massachusetts, USA
| | - Kristin Engelstad
- Department of Neurology, Columbia University Irving Medical Center, New York, New York, USA
| | - Owen S Skinner
- Howard Hughes Medical Institute, Department of Molecular Biology, and.,Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA.,Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, USA.,Broad Institute, Cambridge, Massachusetts, USA
| | - Erin Stackowitz
- Department of Neurology, Columbia University Irving Medical Center, New York, New York, USA
| | - Ronald G Haller
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Institute for Exercise and Environmental Medicine of Texas Health Presbyterian Hospital, Dallas, Texas, USA
| | | | | | - Melissa A Walker
- Howard Hughes Medical Institute, Department of Molecular Biology, and.,Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA.,Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, USA.,Broad Institute, Cambridge, Massachusetts, USA.,Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Robert Fryer
- Department of Neurology, Columbia University Irving Medical Center, New York, New York, USA
| | - Devin Oglesbee
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Xiangling Mao
- Department of Radiology, Weill Cornell Medicine, New York, New York, USA
| | - Dikoma C Shungu
- Department of Radiology, Weill Cornell Medicine, New York, New York, USA
| | - Ashok Khatri
- Endocrine Division and Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Michio Hirano
- Department of Neurology, Columbia University Irving Medical Center, New York, New York, USA
| | - Darryl C De Vivo
- Department of Neurology, Columbia University Irving Medical Center, New York, New York, USA
| | - Vamsi K Mootha
- Howard Hughes Medical Institute, Department of Molecular Biology, and.,Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA.,Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, USA.,Broad Institute, Cambridge, Massachusetts, USA
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Hunt H, Fraser K, Cave NJ, Gartrell BD, Petersen J, Roe WD. Untargeted metabolic profiling of dogs with a suspected toxic mitochondrial myopathy using liquid chromatography-mass spectrometry. Toxicon 2019; 166:46-55. [PMID: 31102596 DOI: 10.1016/j.toxicon.2019.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 04/22/2019] [Accepted: 05/11/2019] [Indexed: 10/26/2022]
Abstract
'Go Slow myopathy' (GSM) is a suspected toxic myopathy in dogs that primarily occurs in the North Island of New Zealand, and affected dogs usually have a history of consuming meat, offal or bones from wild pigs (including previously frozen and/or cooked meat). Previous epidemiological and pathological studies on GSM have demonstrated that changes in mitochondrial structure and function are most likely caused by an environmental toxin that dogs are exposed to through the ingestion of wild pig. The disease has clinical, histological and biochemical similarities to poisoning in people and animals from the plant Ageratina altissima (white snakeroot). Aqueous and lipid extracts were prepared from liver samples of 24 clinically normal dogs and 15 dogs with GSM for untargeted liquid chromatography-mass spectrometry. Group-wise comparisons of mass spectral data revealed 38 features that were significantly different (FDR<0.05) between normal dogs and those with GSM in aqueous extracts, and 316 significantly different features in lipid extracts. No definitive cause of the myopathy was identified, but alkaloids derived from several plant species were among the possible identities of features that were more abundant in liver samples from affected dogs compared to normal dogs. Mass spectral data also revealed that dogs with GSM have reduced hepatic phospholipid and sphingolipid concentrations relative to normal dogs. In addition, affected dogs had changes in the abundance of kynurenic acid, various dicarboxylic acids and N-acetylated branch chain amino acids, suggestive of mitochondrial dysfunction.
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Affiliation(s)
- H Hunt
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - K Fraser
- Food Nutrition and Health Team, Food and Bio-Based Products Group, AgResearch Grasslands Research Centre, Palmerston North, New Zealand
| | - N J Cave
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - B D Gartrell
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - J Petersen
- Norvet Services Ltd., Okaihau, New Zealand
| | - W D Roe
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
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5
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N-lactoyl-amino acids are ubiquitous metabolites that originate from CNDP2-mediated reverse proteolysis of lactate and amino acids. Proc Natl Acad Sci U S A 2015; 112:6601-6. [PMID: 25964343 DOI: 10.1073/pnas.1424638112] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Despite technological advances in metabolomics, large parts of the human metabolome are still unexplored. In an untargeted metabolomics screen aiming to identify substrates of the orphan transporter ATP-binding cassette subfamily C member 5 (ABCC5), we identified a class of mammalian metabolites, N-lactoyl-amino acids. Using parallel protein fractionation in conjunction with shotgun proteomics on fractions containing N-lactoyl-Phe-forming activity, we unexpectedly found that a protease, cytosolic nonspecific dipeptidase 2 (CNDP2), catalyzes their formation. N-lactoyl-amino acids are ubiquitous pseudodipeptides of lactic acid and amino acids that are rapidly formed by reverse proteolysis, a process previously considered to be negligible in vivo. The plasma levels of these metabolites strongly correlate with plasma levels of lactate and amino acid, as shown by increased levels after physical exercise and in patients with phenylketonuria who suffer from elevated Phe levels. Our approach to identify unknown metabolites and their biosynthesis has general applicability in the further exploration of the human metabolome.
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Farrell EK, Merkler DJ. Biosynthesis, degradation and pharmacological importance of the fatty acid amides. Drug Discov Today 2008; 13:558-68. [PMID: 18598910 DOI: 10.1016/j.drudis.2008.02.006] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Revised: 01/29/2008] [Accepted: 02/18/2008] [Indexed: 01/08/2023]
Abstract
The identification of two biologically active fatty acid amides, N-arachidonoylethanolamine (anandamide) and oleamide, has generated a great deal of excitement and stimulated considerable research. However, anandamide and oleamide are merely the best-known and best-understood members of a much larger family of biologically occurring fatty acid amides. In this review, we will outline which fatty acid amides have been isolated from mammalian sources, detail what is known about how these molecules are made and degraded in vivo, and highlight their potential for the development of novel therapeutics.
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Affiliation(s)
- Emma K Farrell
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
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7
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Loots DT, Erasmus E, Mienie LJ. Identification of 19 new metabolites induced by abnormal amino acid conjugation in isovaleric acidemia. Clin Chem 2005; 51:1510-2. [PMID: 16040844 DOI: 10.1373/clinchem.2005.048421] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Du Toit Loots
- Department of Nutrition, School of Physiology, Nutrition and Consumers Science, North-West University, Potchefstroom, South Africa.
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8
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Schadewaldt P, Hammen HW, Ott AC, Wendel U. Renal clearance of branched-chain L-amino and 2-oxo acids in maple syrup urine disease. J Inherit Metab Dis 1999; 22:706-22. [PMID: 10472531 DOI: 10.1023/a:1005540016376] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In maple syrup urine disease (MSUD), branched-chain L-amino (BCAA) and 2-oxo acids (BCOA) accumulate in body fluids owing to an inherited deficiency of branched-chain 2-oxo acid dehydrogenase complex activity. In MSUD, little information is available on the significance of urinary disposal of branched-chain compounds. We examined the renal clearance of leucine, valine, isoleucine and alloisoleucine, and their corresponding 2-oxo acids 4-methyl-2-oxopentanoate (KIC), 3-methyl-2-oxobutanoate (KIV), (S)-(S-KMV), and (R)-3-methyl-2-oxopentanoate (R-KMV), using pairs of plasma and urine samples (n = 63) from 10 patients with classical MSUD. The fractional renal excretion of free BCAA was in the normal range (< 0.5%) and independent of the plasma concentrations. The excretion of bound (N-acylated) BCAA was normal and not significantly dependent on the BCAA plasma concentrations. The fractional renal excretion of BCOA was in the order KIC << KIV < R-KMV < or = S-KMV (range (%): KIC 0.1-25; KIV 0.14-21.3; S-KMV 0.26-24.6; R-KMV 0.1-35.9), significantly correlated with the KIC plasma concentrations, and generally higher than that of the related BCAA. The results show that the renal excretion of free BCAA as well as of the acylated derivatives is negligible. The renal excretion of BCOA, however, to some extent counteracts increases in BCAA concentrations and thus contributes to the lowering of total BCAA pools in MSUD.
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Affiliation(s)
- P Schadewaldt
- Diabetes-Forschungsinstitut an der Heinrich-Heine-Universität, Düsseldorf, Germany.
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