title: Oxidized phosphatidylcholines suggest oxidative stress in patients with medium-chain acyl-CoA dehydrogenase deficiency.
abstract: Inborn errors of metabolism encompass a large group of diseases caused by enzyme deficiencies and are therefore amenable to metabolomics investigations. Medium chain acyl-CoA dehydrogenase deficiency (MCADD) is a defect in β-oxidation of fatty acids, and is one of the most well understood disorders. We report here the use of liquid chromatography-mass spectrometry (LC-MS) based untargeted metabolomics and targeted flow injection analysis-tandem mass spectrometry (FIA-TMS) that lead to discovery of novel compounds of oxidative stress. Dry blood spots of controls (n=25) and patient samples (n=25) were extracted by methanol/water (1/1, v/v) and these supernatants were analyzed by LC-MS method with detection by an Orbitrap Elite MS. Data were processed by XCMS and CAMERA followed by dimension reduction methods. Patients were clearly distinguished from controls in PCA. S-plot derived from OPLS-DA indicated that medium-chain acylcarnitines (octanoyl, decenoyl and decanoyl carnitines) as well as three phosphatidylcholines (PC(16:0,9:0(COOH))), PC(18:0,5:0(COOH)) and PC(16:0,8:0(COOH)) were important metabolites for differentiation between patients and healthy controls. In order to biologically validate these discriminatory molecules as indicators for oxidative stress, a second cohort of individuals were analyzed, including MCADD (n=25) and control (n=250) samples. These were measured by a modified newborn screening method using FIA-TMS (API 4000) in MRM mode. Calculated p-values for PC(16:0,9:0(COOH)), PC(18:0,5:0(COOH)) and PC(16:0,8:0(COOH)) were 1.927×10(-14), 2.391×10(-15) and 3.354×10(-15) respectively. These elevated oxidized phospholipids indeed show an increased presence of oxidative stress in MCADD patients as one of the pathophysiological mechanisms of the disease.
authors.affiliation: Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University and University Hospital in Olomouc, Hnevotínská 5, Olomouc 775 15, Czech Republic.
authors.forename: Lukáš
authors.initials: L
authors.lastname: Najdekr
authors.affiliation: Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University and University Hospital in Olomouc, Hnevotínská 5, Olomouc 775 15, Czech Republic.
authors.forename: Alžběta
authors.initials: A
authors.lastname: Gardlo
authors.affiliation: Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University and University Hospital in Olomouc, Hnevotínská 5, Olomouc 775 15, Czech Republic.
authors.forename: Lucie
authors.initials: L
authors.lastname: Mádrová
authors.affiliation: Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University and University Hospital in Olomouc, Hnevotínská 5, Olomouc 775 15, Czech Republic; Department of Clinical Biochemistry, University Hospital in Olomouc, I.P. Pavlova 6, 775 20 Olomouc, Czech Republic.
authors.forename: David
authors.initials: D
authors.lastname: Friedecký
authors.affiliation: Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University and University Hospital in Olomouc, Hnevotínská 5, Olomouc 775 15, Czech Republic; Department of Clinical Biochemistry, University Hospital in Olomouc, I.P. Pavlova 6, 775 20 Olomouc, Czech Republic.
authors.forename: Hana
authors.initials: H
authors.lastname: Janečková
authors.affiliation: School of Chemistry, Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.
authors.forename: Elon S
authors.initials: ES
authors.lastname: Correa
authors.affiliation: School of Chemistry, Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.
authors.forename: Royston
authors.initials: R
authors.lastname: Goodacre
authors.affiliation: Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University and University Hospital in Olomouc, Hnevotínská 5, Olomouc 775 15, Czech Republic; Department of Clinical Biochemistry, University Hospital in Olomouc, I.P. Pavlova 6, 775 20 Olomouc, Czech Republic. Electronic address: tomasadam@gmail.com.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Adam
mesh_terms: D042964:Acyl-CoA Dehydrogenase / Q000097:blood / Q000172:deficiency*; D015415:Biomarkers / Q000097:blood*; D016022:Case-Control Studies; D006801:Humans; D007231:Infant, Newborn; D008052:Lipid Metabolism, Inborn Errors / Q000097:blood* / Q000473:pathology*; D055442:Metabolome; D015997:Neonatal Screening; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010713:Phosphatidylcholines / Q000737:chemistry*; D010865:Pilot Projects; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D015415:Biomarkers; D010713:Phosphatidylcholines; D042964:Acyl-CoA Dehydrogenase
keywords: Beta-oxidation; Inherited metabolic disorders; Medium chain acyl-CoA dehydrogenase deficiency; Oxidative stress; Phosphatidylcholines; Untargeted metabolomics