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Samodelov SL, Gai Z, De Luca F, Haldimann K, Hobbie SN, Müller D, Kullak-Ublick GA, Visentin M. L-carnitine co-administration prevents colistin-induced mitochondrial permeability transition and reduces the risk of acute kidney injury in mice. Sci Rep 2024; 14:16444. [PMID: 39013979 PMCID: PMC11252255 DOI: 10.1038/s41598-024-67171-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 07/09/2024] [Indexed: 07/18/2024] Open
Abstract
Colistin is a polymyxin antibiotic currently experiencing renewed clinical interest due to its efficacy in the treatment of multidrug resistant (MDR) bacterial infections. The frequent onset of acute dose-dependent kidney injury, with the potential of leading to long-term renal damage, has limited its use and hampered adequate dosing regimens, increasing the risk of suboptimal plasma concentrations during treatment. The mechanism of colistin-induced renal toxicity has been postulated to stem from mitochondrial damage, yet there is no direct evidence of colistin acting as a mitochondrial toxin. The aim of this study was to evaluate whether colistin can directly induce mitochondrial toxicity and, if so, uncover the underlying molecular mechanism. We found that colistin leads to a rapid permeability transition of mitochondria isolated from mouse kidney that was fully prevented by co-incubation of the mitochondria with desensitizers of the mitochondrial transition pore cyclosporin A or L-carnitine. The protective effect of L-carnitine was confirmed in experiments in primary cultured mouse tubular cells. Consistently, the relative risk of colistin-induced kidney damage, calculated based on histological analysis as well as by the early marker of tubular kidney injury, Kim-1, was halved under co-administration with L-carnitine in vivo. Notably, L-carnitine neither affected the pharmacokinetics of colistin nor its antimicrobial activity against relevant bacterial strains. In conclusion, colistin targets the mitochondria and induces permeability transition thereof. L-carnitine prevents colistin-induced permeability transition in vitro. Moreover, L-carnitine co-administration confers partial nephroprotection in mice treated with colistin, without interfering with its pharmacokinetics and antibacterial activity.
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Affiliation(s)
- Sophia L Samodelov
- Department of Clinical Pharmacology and Toxicology, University Hospital Zürich, University of Zürich, 8006, Zürich, Switzerland
| | - Zhibo Gai
- Department of Clinical Pharmacology and Toxicology, University Hospital Zürich, University of Zürich, 8006, Zürich, Switzerland
- Experimental Center, Shandong University of Traditional Chinese Medicine, Jinan, 250355, China
| | - Francesca De Luca
- Department of Clinical Pharmacology and Toxicology, University Hospital Zürich, University of Zürich, 8006, Zürich, Switzerland
| | - Klara Haldimann
- Institute of Medical Microbiology, University of Zürich, 8006, Zürich, Switzerland
| | - Sven N Hobbie
- Institute of Medical Microbiology, University of Zürich, 8006, Zürich, Switzerland
| | - Daniel Müller
- Institute of Clinical Chemistry, University Hospital Zürich, University of Zürich, 8006, Zürich, Switzerland
- Laboratory Medicine, University of Basel, 4056, Basel, Switzerland
| | - Gerd A Kullak-Ublick
- Department of Clinical Pharmacology and Toxicology, University Hospital Zürich, University of Zürich, 8006, Zürich, Switzerland
- Mechanistic Safety, Patient Safety & Pharmacovigilance, Clinical Development and Medical Affairs, Novartis Pharma, 4056, Basel, Switzerland
| | - Michele Visentin
- Department of Clinical Pharmacology and Toxicology, University Hospital Zürich, University of Zürich, 8006, Zürich, Switzerland.
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De la Rosa MVG, Patel D, McCann MR, Stringer KA, Rosania GR. Database screening as a strategy to identify endogenous candidate metabolites to probe and assess mitochondrial drug toxicity. Sci Rep 2023; 13:22013. [PMID: 38086883 PMCID: PMC10716408 DOI: 10.1038/s41598-023-49443-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 12/08/2023] [Indexed: 12/18/2023] Open
Abstract
Adverse drug reactions (ADRs) are considered an inherent risk of medication use, and some ADRs have been associated with off-target drug interactions with mitochondria. Metabolites that reflect mitochondrial function may help identify patients at risk of mitochondrial toxicity. We employed a database strategy to identify candidate mitochondrial metabolites that could be clinically useful to identify individuals at increased risk of mitochondrial-related ADRs. This led to L-carnitine being identified as the candidate mitochondrial metabolite. L-carnitine, its acetylated metabolite, acetylcarnitine and other acylcarnitines are mitochondrial biomarkers used to detect inborn errors of metabolism. We hypothesized that changes in L-carnitine disposition, induced by a "challenge test" of intravenous L-carnitine, could identify mitochondrial-related ADRs by provoking variation in L-carnitine and/or acetylcarnitine blood levels. To test this hypothesis, we induced mitochondrial drug toxicity with clofazimine (CFZ) in a mouse model. Following CFZ treatment, mice received an L-carnitine "challenge test". CFZ-induced changes in weight were consistent with previous work and reflect CFZ-induced catabolism. L-carnitine induced differences in whole blood acetylcarnitine concentrations in a manner that was dependent on CFZ treatment. This supports the usefulness of a database strategy for the discovery of candidate metabolite biomarkers of drug toxicity and substantiates the potential of the L-carnitine "challenge test" as a "probe" to identify drug-related toxicological manifestations.
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Affiliation(s)
- Mery Vet George De la Rosa
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48104, USA
| | - Dipali Patel
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48104, USA
| | - Marc R McCann
- The NMR Metabolomics Laboratory, Department of Clinical Pharmacy, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Kathleen A Stringer
- The NMR Metabolomics Laboratory, Department of Clinical Pharmacy, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, School of Medicine, University of Michigan, Ann Arbor, MI, 48109, USA
- Weil Institute for Critical Care Research and Innovation, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Gus R Rosania
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48104, USA.
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3
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Abrahamsen RK, Lund AM, Rasmussen J. Patients with primary carnitine deficiency treated with L-carnitine are alive and doing well-A 10-year follow-up in the Faroe Islands. JIMD Rep 2023; 64:453-459. [PMID: 37927485 PMCID: PMC10623095 DOI: 10.1002/jmd2.12383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 07/11/2023] [Indexed: 11/07/2023] Open
Abstract
Primary carnitine deficiency (PCD) can be lethal. Carnitine is essential for the transfer of long-chain fatty acids across the inner mitochondrial membrane for β-oxidation. The reported prevalence of PCD in the Faroe Islands of 1:300 is the highest in the world. The Faroese PCD patient cohort has been closely monitored and we now report results from a 10-year follow-up study of 139 PCD patients. Four patients have died of natural causes since diagnosis. There were no signs of cardiac complications related to PCD. 70.5% reported an effect of L-carnitine treatment. 33.7% reported current symptoms with fatigue and low stamina being the most common. 65.1% had experienced side effects during L-carnitine treatment. Most common side effects were fish odor, abdominal pain, and diarrhea. The overall mean L-carnitine dosage was 66.3 mg/kg/day. Free p-carnitine was similar between male and female patients on L-carnitine-18.6 and 18.8 μmol/L, respectively. L-carnitine supplementation seems to be a safe and effective treatment when suffering from PCD. PCD patients in the Faroe Islands are alive and doing well more than 10 years after diagnosis.
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Affiliation(s)
- Rannvá K. Abrahamsen
- Gastro Unit, Medical DivisionCopenhagen University Hospital‐Amager and HvidovreHvidovreDenmark
- Department of Internal MedicineNational HospitalTórshavnFaroe Islands
| | - Allan M. Lund
- Department of Pediatrics and Clinical Genetics, Centre for Inherited Metabolic DiseasesCopenhagen University Hospital, RigshospitaletCopenhagenDenmark
| | - Jan Rasmussen
- Department of Internal MedicineNational HospitalTórshavnFaroe Islands
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4
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Hsu J, Fatuzzo N, Weng N, Michno W, Dong W, Kienle M, Dai Y, Pasca A, Abu-Remaileh M, Rasgon N, Bigio B, Nasca C, Khosla C. Carnitine octanoyltransferase is important for the assimilation of exogenous acetyl-L-carnitine into acetyl-CoA in mammalian cells. J Biol Chem 2023; 299:102848. [PMID: 36587768 PMCID: PMC9898754 DOI: 10.1016/j.jbc.2022.102848] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 12/20/2022] [Accepted: 12/23/2022] [Indexed: 12/31/2022] Open
Abstract
In eukaryotes, carnitine is best known for its ability to shuttle esterified fatty acids across mitochondrial membranes for β-oxidation. It also returns to the cytoplasm, in the form of acetyl-L-carnitine (LAC), some of the resulting acetyl groups for posttranslational protein modification and lipid biosynthesis. While dietary LAC supplementation has been clinically investigated, its effects on cellular metabolism are not well understood. To explain how exogenous LAC influences mammalian cell metabolism, we synthesized isotope-labeled forms of LAC and its analogs. In cultures of glucose-limited U87MG glioma cells, exogenous LAC contributed more robustly to intracellular acetyl-CoA pools than did β-hydroxybutyrate, the predominant circulating ketone body in mammals. The fact that most LAC-derived acetyl-CoA is cytosolic is evident from strong labeling of fatty acids in U87MG cells by exogenous 13C2-acetyl-L-carnitine. We found that the addition of d3-acetyl-L-carnitine increases the supply of acetyl-CoA for cytosolic posttranslational modifications due to its strong kinetic isotope effect on acetyl-CoA carboxylase, the first committed step in fatty acid biosynthesis. Surprisingly, whereas cytosolic carnitine acetyltransferase is believed to catalyze acetyl group transfer from LAC to coenzyme A, CRAT-/- U87MG cells were unimpaired in their ability to assimilate exogenous LAC into acetyl-CoA. We identified carnitine octanoyltransferase as the key enzyme in this process, implicating a role for peroxisomes in efficient LAC utilization. Our work has opened the door to further biochemical investigations of a new pathway for supplying acetyl-CoA to certain glucose-starved cells.
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Affiliation(s)
- Jake Hsu
- Department of Chemical Engineering, Stanford University, Stanford, California, USA
| | - Nina Fatuzzo
- Department of Chemistry, Stanford University, Stanford, California, USA
| | - Nielson Weng
- Department of Chemistry, Stanford University, Stanford, California, USA
| | - Wojciech Michno
- Division of Neonatology, Department of Pediatrics, Stanford University, Stanford, California, USA
| | - Wentao Dong
- Department of Chemical Engineering, Stanford University, Stanford, California, USA; Department of Genetics, Stanford University, Stanford, California, USA
| | - Maryline Kienle
- Department of Chemistry, Stanford University, Stanford, California, USA
| | - Yuqin Dai
- Sarafan ChEM-H, Stanford, California, USA
| | - Anca Pasca
- Division of Neonatology, Department of Pediatrics, Stanford University, Stanford, California, USA
| | - Monther Abu-Remaileh
- Department of Chemical Engineering, Stanford University, Stanford, California, USA; Department of Genetics, Stanford University, Stanford, California, USA; Sarafan ChEM-H, Stanford, California, USA
| | - Natalie Rasgon
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, California, USA
| | - Benedetta Bigio
- Department of Psychiatry, Grossman School of Medicine, New York University, New York, New York, USA
| | - Carla Nasca
- Department of Psychiatry, Grossman School of Medicine, New York University, New York, New York, USA; Department of Neuroscience and Physiology, New York University Neuroscience Institute, Grossman School of Medicine, New York University, New York, New York, USA; Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology, The Rockefeller University, New York, New York, USA
| | - Chaitan Khosla
- Department of Chemical Engineering, Stanford University, Stanford, California, USA; Department of Chemistry, Stanford University, Stanford, California, USA; Sarafan ChEM-H, Stanford, California, USA.
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5
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Verbeeten KC, Lamhonwah AM, Bulman D, Faghfoury H, Chakraborty P, Tein I, Geraghty MT. Carnitine uptake defect due to a 5'UTR mutation in a pedigree with false positives and false negatives on Newborn screening. Mol Genet Metab 2020; 129:213-218. [PMID: 31864849 DOI: 10.1016/j.ymgme.2019.12.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 10/23/2019] [Accepted: 12/08/2019] [Indexed: 11/22/2022]
Abstract
Carnitine Uptake Defect (CUD) is an autosomal recessive disorder due to mutations in the SLC22A5 gene. Classically patients present in infancy with profound muscle weakness and cardiomyopathy with characteristic EKG findings. Later presentations include recurrent hypoketotic hypoglycemia, proximal limb girdle myopathy,and/or recurrent muscle pain. Newborn screening detects most of these clinical variants but in addition has identified maternal CUD often in asymptomatic women. We describe a family ascertained through 3 newborn screening (NBS) positive infants found to be unaffected themselves but in whom the mothers (sisters) were affected. There were also two affected children born to an affected male and his heterozygous wife who were false negatives on NBS but had increased fractional excretion of free carnitine in the urine. Analysis on a Next Generation Sequencing panel specifically designed to fully cover newborn screening disease targets showed a homozygous change in the five probands (SLC22A5; NM_003060:c.-149G > A; p.?). The mutation segregates with the CUD within the family. It is in the 5' UTR and has a frequency within the gnomAd database of 0.001198. Plasma carnitine was decreased and fractional excretion of free carnitine was increased in all affected individuals. Functional carnitine uptake studies in cultured skin fibroblasts of one proband showed carnitine uptake at the 5 μM concentration to be 6% of controls. Relative expression of OCTN2 mRNA to beta-actin mRNA by qRT-PCR was increased in a proband relative to controls by a factor of 465-fold. Western blotting revealed a 120 kDa protein band, as well as a weaker 240 kDa band in the proband, the significance of which is unknown at this time.
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Affiliation(s)
| | - Anne-Marie Lamhonwah
- University of Toronto, Toronto, ON, Canada; Dept. of Pediatrics, Laboratory Medicine and Pathobiology, University of Toronto, Canada; Genetics and Genome Biology Program, Hospital for Sick Children, University of Toronto, Canada
| | - Dennis Bulman
- University of Ottawa, Ottawa, ON, Canada; Newborn Screening Ontario, Canada; Children's Hospital of Eastern Ontario, Canada
| | | | - P Chakraborty
- University of Ottawa, Ottawa, ON, Canada; Newborn Screening Ontario, Canada; Children's Hospital of Eastern Ontario, Canada
| | - Ingrid Tein
- University of Toronto, Toronto, ON, Canada; Dept. of Pediatrics, Laboratory Medicine and Pathobiology, University of Toronto, Canada; Genetics and Genome Biology Program, Hospital for Sick Children, University of Toronto, Canada
| | - Michael T Geraghty
- University of Ottawa, Ottawa, ON, Canada; Newborn Screening Ontario, Canada; Children's Hospital of Eastern Ontario, Canada.
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6
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Rasmussen J, Dunø M, Lund AM, Steuerwald U, Hansen SH, Joensen HD, Køber L, Nielsen OW. Increased risk of sudden death in untreated primary carnitine deficiency. J Inherit Metab Dis 2020; 43:290-296. [PMID: 31373028 DOI: 10.1002/jimd.12158] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 07/17/2019] [Accepted: 07/29/2019] [Indexed: 12/22/2022]
Abstract
Primary carnitine deficiency (PCD) affects fatty acid oxidation and is associated with cardiomyopathy and cardiac arrhythmia, but the risk of sudden death in PCD is unknown. The Faroe Islands have a high prevalence of PCD, 1:300. This study systematically investigated a possible association between untreated PCD and sudden death in young Faroese subjects. We investigated all medico-legal cases of sudden death between 1979 and 2012 among subjects below the age of 45. Stored biomaterial was examined with molecular genetic analysis to reveal PCD. We compared the prevalence of PCD among sudden death cases with that of the background population (0.23%) to calculate the odds ratio (OR) for sudden death with PCD. Biomaterial was available and genetically analyzed from 53 of 65 sudden death cases (82%) in the Faroe Islands. Six (one male and five females) of the 53 cases were homozygous for the PCD related c.95A>G mutation-a prevalence of 11.3% (95% CI 5%-23%) and an OR of 54.3 (95% CI 21-138, P < .0001) for the association between sudden death and untreated PCD. Only 11 of the 53 sudden death cases were women-of whom five were homozygous for the c.95A>G mutation (45.5%) yielding an OR of 348.8 (95% CI 94-1287, P < .0001) for the association between sudden death and untreated PCD in females. This study showed a strong association between sudden death and untreated PCD, especially in females.
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Affiliation(s)
- Jan Rasmussen
- Department of Internal Medicine, National Hospital, Torshavn, Faroe Islands
- Department of Cardiology, Rigshospitalet University Hospital, Copenhagen, Denmark
| | - Morten Dunø
- Department of Clinical Genetics, Centre for Inherited metabolic Diseases, Copenhagen University Hospital, Copenhagen, Denmark
| | - Allan M Lund
- Department of Clinical Genetics, Centre for Inherited metabolic Diseases, Copenhagen University Hospital, Copenhagen, Denmark
| | - Ulrike Steuerwald
- Department of Occupational and Public Health, Faroese National Health System, Torshavn, Faroe Islands
| | - Steen-Holger Hansen
- Section of Forensic Pathology, Department of Forensic Medicine, University of Copenhagen, Copenhagen, Denmark
| | | | - Lars Køber
- Department of Cardiology, Rigshospitalet University Hospital, Copenhagen, Denmark
| | - Olav W Nielsen
- Department of Cardiology, Bispebjerg University Hospital, Copenhagen, Denmark
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7
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Wilson C, Knoll D, de Hora M, Kyle C, Glamuzina E, Webster D. The decision to discontinue screening for carnitine uptake disorder in New Zealand. J Inherit Metab Dis 2019; 42:86-92. [PMID: 30740730 DOI: 10.1002/jimd.12030] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
When screening for carnitine uptake disorder (CUD), the New Zealand (NZ) newborn screening (NBS) service identified infants as screen-positive if they had initial and repeat free carnitine (C0) levels of less than 5.0 μmol/L. Since 2006, the NBS service has identified two infants with biochemical and genetic features consistent with neonatal CUD and nine mothers with features consistent with maternal CUD. A review of the literature suggests that these nine women reflect less than half the true prevalence and that CUD is relatively common. However, the NZ results (two infants) suggest a very low sensitivity and positive predictive value of NBS. While patients presenting with significant disease due to CUD are well described, the majority of adults with CUD are asymptomatic. Nonetheless, treatment with high-dose oral L-carnitine is recommended. Compliance with oral L-carnitine is likely to be poor long term. This may represent a specific risk as treatment could repress the usual compensatory mechanisms seen in CUD, such that a sudden discontinuation of treatment may be dangerous. L-carnitine is metabolized to trimethylamine-N-oxide (TMAO) and treated patients have extremely high plasma TMAO levels. TMAO is an independent risk factor for atherosclerosis and, thus, caution should be exercised regarding long-term treatment with high-dose carnitine of asymptomatic patients who may have a biochemical profile without disease. Due to these concerns, the NZ Newborn Metabolic Screening Programme (NMSP) initiated a review via a series of advisory and governance committees and decided to discontinue screening for CUD.
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Affiliation(s)
- Callum Wilson
- National Metabolic Service, Starship Children's Hospital, P.O. Box 92024, Auckland 1142, New Zealand
| | - Detlef Knoll
- Newborn Metabolic Screening Unit, Auckland City Hospital, Auckland, New Zealand
| | - Mark de Hora
- Newborn Metabolic Screening Programme, LabPlus, Auckland City Hospital, Auckland, New Zealand
| | - Campbell Kyle
- LabPlus, Auckland City Hospital, Auckland, New Zealand
| | - Emma Glamuzina
- National Metabolic Service, Starship Children's Hospital, P.O. Box 92024, Auckland 1142, New Zealand
| | - Dianne Webster
- Newborn Metabolic Screening Programme, LabPlus, Auckland City Hospital, Auckland, New Zealand
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8
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Zhou W, Li H, Huang T, Zhang Y, Wang C, Gu M. Biochemical, Molecular, and Clinical Characterization of Patients With Primary Carnitine Deficiency via Large-Scale Newborn Screening in Xuzhou Area. Front Pediatr 2019; 7:50. [PMID: 30863740 PMCID: PMC6399307 DOI: 10.3389/fped.2019.00050] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Accepted: 02/06/2019] [Indexed: 12/31/2022] Open
Abstract
Background: Primary carnitine deficiency (PCD) is attributed to a variation in the SLC22A5 (OCTN2) gene which encodes the key protein of the carnitine cycle, the OCTN2 carnitine transporter. PCD is typically identified in childhood by either hypoketotic hypoglycemia, or skeletal and cardiac myopathy. The aim of this study was to the clinical, biochemical, and molecular characteristics of PCD patients via newborn screening with tandem mass spectrometry (MS/MS). Methods: MS/MS was performed to screen newborns for inherited metabolic diseases. SLC22A5 gene mutations were detected in the individual and/or their family member by DNA mass array and next-generation sequencing (NGS). Results: Among the 236,368 newborns tested, ten exhibited PCD, and six others were diagnosed with low carnitine levels caused by their mothers, who had asymptomatic PCD. The incidence of PCD in the Xuzhou area is ~1:23,637. The mean initial free carnitine (C0) concentration of patients was 6.41 ± 2.01 μmol/L, and the follow-up screening concentration was 5.80 ± 1.29 μmol/L. After treatment, the concentration increased to 22.8 ± 4.13 μmol/L. Conclusion: This study demonstrates the important clinical value of combining MS/MS and NGS for the diagnosis of PCD and provides new insight into the diagnosis of PCD and maternal patients with PCD using C0 concentration and SLC22A5 mutations.
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Affiliation(s)
- Wei Zhou
- Xuzhou Maternity and Child Health Care Hospital, Xuzhou, China
| | - Huizhong Li
- Xuzhou Maternity and Child Health Care Hospital, Xuzhou, China
| | - Ting Huang
- Xuzhou Maternity and Child Health Care Hospital, Xuzhou, China
| | - Yan Zhang
- Xuzhou Maternity and Child Health Care Hospital, Xuzhou, China
| | - Chuanxia Wang
- Xuzhou Maternity and Child Health Care Hospital, Xuzhou, China
| | - Maosheng Gu
- Xuzhou Maternity and Child Health Care Hospital, Xuzhou, China
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9
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Madsen KL, Preisler N, Rasmussen J, Hedermann G, Olesen JH, Lund AM, Vissing J. L-Carnitine Improves Skeletal Muscle Fat Oxidation in Primary Carnitine Deficiency. J Clin Endocrinol Metab 2018; 103:4580-4588. [PMID: 30219858 DOI: 10.1210/jc.2018-00953] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 09/10/2018] [Indexed: 12/30/2022]
Abstract
CONTEXT Primary carnitine deficiency (PCD) is an inborn error of fatty acid metabolism. Patients with PCD are risk for sudden heart failure upon fasting or illness if they are not treated with daily l-carnitine. OBJECTIVE To investigate energy metabolism during exercise in patients with PCD with and without l-carnitine treatment. DESIGN Interventional study. SETTING Hospital exercise laboratories and department of cardiology. PARTICIPANTS Eight adults with PCD who were homozygous for the c.95A>G (p.N32S) mutation and 10 healthy age- and sex-matched controls. INTERVENTION Four-day pause in l-carnitine treatment. MAIN OUTCOME MEASURES Total fatty acid and palmitate oxidation rates during 1-hour submaximal cycle ergometer exercise assessed with stable isotope method (U13C-palmitate and 2H2-d-glucose) and indirect calorimetry with and without l-carnitine. RESULTS Total fatty acid oxidation rate was higher in patients with l-carnitine treatment during exercise than without treatment [12.3 (SD, 3.7) vs 8.5 (SD, 4.6) µmol × kg-1 × min-1; P = 0.008]. However, the fatty acid oxidation rate was still lower in patients treated with l-carnitine than in the healthy controls [29.5 (SD, 10.1) µmol × kg-1 × min-1; P < 0.001] and in the l-carnitine group without treatment it was less than one third of that in the healthy controls (P < 0.001). In line with this, the palmitate oxidation rates during exercise were lower in the no-treatment period [144 (SD, 66) µmol × kg-1 × min-1] than during treatment [204 (SD, 84) µmol × kg-1 × min-1; P = 0.004) . CONCLUSIONS The results indicate that patients with PCD have limited fat oxidation during exercise. l-Carnitine treatment in asymptomatic patients with PCD may not only prevent cardiac complications but also boost skeletal muscle fat metabolism during exercise.
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Affiliation(s)
- Karen Lindhardt Madsen
- Copenhagen Neuromuscular Center, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
| | - Nicolai Preisler
- Copenhagen Neuromuscular Center, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
| | - Jan Rasmussen
- Department of Internal Medicine, The National Hospital of the Faroe Islands, Tórshavn, Faroe Islands
| | - Gitte Hedermann
- Copenhagen Neuromuscular Center, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
| | - Jess Have Olesen
- Centre for Inherited Metabolic Diseases, Department of Clinical Genetics, Rigshospitalet, Copenhagen, Denmark
| | - Allan Meldgaard Lund
- Centre for Inherited Metabolic Diseases, Department of Clinical Genetics, Rigshospitalet, Copenhagen, Denmark
| | - John Vissing
- Copenhagen Neuromuscular Center, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
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10
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Rasmussen J, Hougaard DM, Sandhu N, Fjællegaard K, Petersen PR, Steuerwald U, Lund AM. Primary Carnitine Deficiency: Is Foetal Development Affected and Can Newborn Screening Be Improved? JIMD Rep 2017; 36:35-40. [PMID: 28105570 DOI: 10.1007/8904_2016_30] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 11/15/2016] [Accepted: 11/23/2016] [Indexed: 12/30/2022] Open
Abstract
UNLABELLED Primary carnitine deficiency (PCD) causes low levels of carnitine in patients potentially leading to metabolic and cardiac symptoms. Newborn screening for PCD is now routine in many countries by measuring carnitine levels in infants. In this study we report Apgar scores, length and weight in newborns with PCD and newborns born to mothers with PCD compared to controls. Furthermore we report how effective different screening algorithms have been to detect newborns with PCD in the Faroe Islands. RESULTS Newborns with PCD and newborns born to mothers with PCD did not differ with regard to Apgar scores, length and weight compared to controls. Newborns with PCD and newborns born to mothers with PCD had significantly lower levels of free carnitine (fC0) than controls. Screening algorithms focusing only on fC0 had a high rate of detection of newborns with PCD. Sample collection 4-9 days after birth seems to result in a higher detection rate than the current 2-3 days. CONCLUSION The clinical status at birth in infants with PCD and infants born to mothers with PCD does not differ compared to control infants. Screening algorithms for PCD should focus on fC0, and blood samples should be taken when the maternal influence on fC0 has diminished.
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Affiliation(s)
- Jan Rasmussen
- Department of Internal Medicine, National Hospital, FO-100, Torshavn, Faroe Islands.
| | - David M Hougaard
- Section of Neonatal Screening and Hormones, Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
| | - Noreen Sandhu
- Section of Neonatal Screening and Hormones, Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
| | - Katrine Fjællegaard
- Department of Internal Medicine, National Hospital, FO-100, Torshavn, Faroe Islands
| | - Poula R Petersen
- Department of Internal Medicine, National Hospital, FO-100, Torshavn, Faroe Islands
| | - Ulrike Steuerwald
- Department of Occupational and Public Health, National Hospital System, Torshavn, Faroe Islands.,Screening-Laboratories Hannover, Hannover, Germany
| | - Allan M Lund
- Centre for Inherited Metabolic Diseases, Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
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A Moderate Carnitine Deficiency Exacerbates Isoproterenol-Induced Myocardial Injury in Rats. Cardiovasc Drugs Ther 2016; 30:119-27. [DOI: 10.1007/s10557-016-6647-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Longo N, Frigeni M, Pasquali M. Carnitine transport and fatty acid oxidation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:2422-35. [PMID: 26828774 DOI: 10.1016/j.bbamcr.2016.01.023] [Citation(s) in RCA: 480] [Impact Index Per Article: 60.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 01/27/2016] [Accepted: 01/28/2016] [Indexed: 12/14/2022]
Abstract
Carnitine is essential for the transfer of long-chain fatty acids across the inner mitochondrial membrane for subsequent β-oxidation. It can be synthesized by the body or assumed with the diet from meat and dairy products. Defects in carnitine biosynthesis do not routinely result in low plasma carnitine levels. Carnitine is accumulated by the cells and retained by kidneys using OCTN2, a high affinity organic cation transporter specific for carnitine. Defects in the OCTN2 carnitine transporter results in autosomal recessive primary carnitine deficiency characterized by decreased intracellular carnitine accumulation, increased losses of carnitine in the urine, and low serum carnitine levels. Patients can present early in life with hypoketotic hypoglycemia and hepatic encephalopathy, or later in life with skeletal and cardiac myopathy or sudden death from cardiac arrhythmia, usually triggered by fasting or catabolic state. This disease responds to oral carnitine that, in pharmacological doses, enters cells using the amino acid transporter B(0,+). Primary carnitine deficiency can be suspected from the clinical presentation or identified by low levels of free carnitine (C0) in the newborn screening. Some adult patients have been diagnosed following the birth of an unaffected child with very low carnitine levels in the newborn screening. The diagnosis is confirmed by measuring low carnitine uptake in the patients' fibroblasts or by DNA sequencing of the SLC22A5 gene encoding the OCTN2 carnitine transporter. Some mutations are specific for certain ethnic backgrounds, but the majority are private and identified only in individual families. Although the genotype usually does not correlate with metabolic or cardiac involvement in primary carnitine deficiency, patients presenting as adults tend to have at least one missense mutation retaining residual activity. This article is part of a Special Issue entitled: Mitochondrial Channels edited by Pierre Sonveaux, Pierre Maechler and Jean-Claude Martinou.
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Affiliation(s)
- Nicola Longo
- Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA; Department of Pathology, University of Utah, and ARUP Laboratories, 500 Chipeta Way, Salt Lake City, UT, USA.
| | - Marta Frigeni
- Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Marzia Pasquali
- Department of Pathology, University of Utah, and ARUP Laboratories, 500 Chipeta Way, Salt Lake City, UT, USA
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