Acylcarnitines Research Articles

Profiling of lipidomics before and after antipsychotic treatment in first-episode psychosis.

Alterations in complex lipids may be involved in pathophysiology of schizophrenia spectrum disorders. Previously, we demonstrated importance of detecting lipid metabolism dysregulation by acylcarnitine (ACs) profile analysis in patients with first-episode psychosis (FEP). The aim of this study was to adopt lipidomics to identify serum glycerophospholipids (GPLs) and sphingomyelins (SMs) for describing FEP status before and after 7-month antipsychotic treatment. Using mass spectrometry and liquid chromatography technique, we profiled 105 individual lipids [14 lysophosphatidylcholines (LysoPCs), 76 phosphatidylcholines (PCs) and 15 SMs] in serum samples from 53 antipsychotic-naïve FEP patients, 44 of them were studied longitudinally and from 37 control subjects (CSs). Among the identified and quantified metabolites one LysoPC was elevated, and contrary the levels of 16 PCs as well as the level of one SM were significantly (p ≤ 0.0005) reduced in antipsychotic-naïve FEP patients compared to CSs. Comparison of serum lipids profiles of FEP patients before and after 7-month antipsychotic treatment revealed that 11 GPLs (2 LysoPCs, 9 PCs), and 2 SMs were found to be significantly changed (p ≤ 0.0005) in which GPLs were up-regulated, and SMs were down-regulated. However, no significant differences were noted when treated patient's serum lipid profiles were compared with CSs. Our findings suggest that complex lipid profile abnormalities are specifically associated with FEP and these discrepancies reflect two different disease-related pathways. Our findings provide insight into lipidomic information that may be used for monitoring FEP status and impact of the treatment in the early stage of the schizophrenia spectrum disorder.

Metabolomic analyses reveal lipid abnormalities and hepatic dysfunction in non-human primate model for Yersinia pestis

IntroductionPneumonic plague is caused by the aerosolized form of Yersinia pestis and is a highly virulent infection with complex clinical consequences, and without treatment, the fatality rate approaches 100%. The exact mechanisms of disease progression are unclear, with limited work done using metabolite profiling to study disease progression.ObjectiveThe aim of this pilot study was to profile the plasma metabolomics in an animal model of Y. pestis infection.MethodsIn this study, African Green monkeys were challenged with the highly virulent, aerosolized Y. pestis strain CO92, and untargeted metabolomics profiling of plasma was performed using liquid and gas chromatography with mass spectrometry.ResultsAt early time points post-exposure, we found significant increases in polyunsaturated, long chain fatty acid metabolites with p values ranging from as low as 0.000001 (ratio = 1.94) for the metabolite eicosapentaenoate to 0.04 (ratio = 1.36) for the metabolite adrenate when compared to time-matched controls. Multiple acyl carnitines metabolites were increased at earlier time points and could be a result of fatty acid oxidation defects with p values ranging from as low as 0.00001 (ratio = 2.95) for the metabolite octanoylcarnitine to 0.04 (ratio = 1.33) for metabolite deoxycarnitine when compared to time-matched controls. Dicarboxylic acids are important metabolic products of fatty acids oxidation, and when compared to time matched controls, were higher at earlier time points where metabolite tetradecanedioate has a ratio of 4.09 with significant p value of 0.000002 and adipate with a ratio of 1.12 and p value of 0.004. The metabolites from lysolipids (with significant p values ranging from 0.00006 for 1-oleoylglycerophosphoethanolamine to 0.04 for 1-stearoylglycerophosphoethanolamine and a ratio of 0.47 and 0.78, respectively) and bile acid metabolism (with significant p values ranging from 0.02 for cholate to 0.04 for deoxycholate and a ratio of 0.39 and 0.66, respectively) pathways were significantly lower compared to their time-matched controls during the entire course of infection. Metabolite levels from amino acid pathways were disrupted, and a few from the leucine, isoleucine and valine pathway were significantly higher (p values ranging from 0.002 to 0.04 and ratios ranging from 1.3 to 1.5, respectively), whereas metabolites from the urea cycle, arginine and proline pathways were significantly lower (p values ranging from 0.00008 to 0.02 and ratios ranging from 0.5 to 0.7, respectively) during the course of infection.ConclusionsThe involvement of several lipid pathways post-infection suggested activation of pathways linked to inflammation and oxidative stress. Metabolite data further showed increased energy demand, and multiple metabolites indicated potential hepatic dysfunction. Integration of blood metabolomics and transcriptomics data identified linoleate as a core metabolite with cross-talk with multiple genes from various time points. Collectively, the data from this study provided new insights into the mechanisms of Y. pestis pathogenesis that may aid in development of therapeutics.

Cardiac manifestations of inherited metabolic disease linked to cellular vitamin B12 uptake: Study in murine model of invalidation of Mtr gene in the heart

Heart failure is one of the most common causes of death in the Western societies and its incidence is increasing in the non developing countries. Deficiency in methyl donors (folates and vitamin B12) during gestation and lactation causes a foetal programming effect with cardiomyopathy related to decreased synthesis of methionine by methionine synthase (MTR). Methionine is the precursor for S-adenosyl methionine (SAM) the universal methyl donor for epigenomic regulations. Mutation in MTR gene causes cardiac decompensation in the new-borns by unknown mechanisms. The objective of our study is to investigate the metabolic and functional consequences of long-term inhibition of synthesis of methionine and SAM in mice model of conditional knock out of Mtr gene in the heart (MTR KO). Deletion of the Mtr gene in C57BL/6 mice was achieved by Cre/Lox system. Systolic Blood Pressure (SBP) in conscious mice was measured by tail-cuff system. left-ventricular (LV) function, cardiac morphology and tissue perfusion were assessed by MiniPET and Echocardiography. RT-qPCR was used for gene expression analysis while proteomic study on total heart proteins was achieved by LC-MS/MS. Systolic hypertension, a significant decrease in LV ejection fraction percentage and increase in LV mass was observed in MTR KO mice as compared to the control. Moreover, RT-qPCR confirmed an upregulated expression of the hallmarks of heart failure: natriuretic peptides (ANP and BNP) in MTR KO mice. Metabolic and biochemical studies in heart tissue showed significant decrease in SAM/SAH, cardiac fibrosis, elevated plasma acyl carnitine levels and different mitochondrial protein expression in MTR KO mice. Our results suggest that methionine synthase dysfunction induces hypertension, cardiac hypertrophy, fibrosis, ventricular dysfunction and dysregulated energy metabolism in the heart.

231 Urinary metabotyping around parturition indicates consistent metabolite signatures that can be used for monitoring and diagnosing of subclinical mastitis in dairy cows.

The objective of this study was to identify urinary metabolite signatures that can be used for monitoring and diagnosing of subclinical mastitis in Holstein dairy cows. Six multiparous pregnant Holstein cows with subclinical mastitis (SCM) and 20 healthy controls (CON) were selected out of 100 cows in the study. DI/LC-MS/MS-based urinary analyses were conducted on samples collected at -8, -4, SCM diagnosis, and at +4 and +8 wks around the expected day of calving. Data indicated that 14 amino acids and derivatives were found in the urine with Gln and SDMA consistently increased (P<0.005) in the urine of SCM cows. Out of 39 acylcarnitines (ACs) quantified C12:DC, C14, and C18:2, were higher (P<0.05) in SCM at all time points (P<0.05). Seventeen ACs at -8 wks, 10 at -4 wks, 23 at disease wk, 8 at +4 wks, and 12 at +8 wks were higher (P<0.05) in the urine of SCM cows. Most of the alterations regarding lysophosphatidylcholines (LPCs) were found at -8 and -4 wks prepartum with 6 and 4 LPCs species lowered at -8 and -4 wks, respectively (P<0.05). Multiple sphingomyelin (SM) species prior to calving (3 at -8 wks and 8 at -4 wks) and 2 at disease week were lowered in SCM cows (P<0.05). A total of 74 phosphatidylcholines (PCs) were measured in the urine. A total of 12, 12, 10, 9, and 9 species of PC aa and 7, 15, 15, 3, and 3 species of PC ae were altered during weeks -8, -4, Disease wk, +4, + 8 wks around calving. Overall, multiple metabolite species related to amino acids, ACs, LPCs, and PCs metabolism were identified as altered in the urine of periparturient dairy cows. Some of the most important metabolites might be used as biomarkers to screen cows for SCM.

Yield of laboratory testing in pediatric ketogenic diet patients: Critical assessment of abnormal results and impact on clinical care

Objectives: To retrospectively assess the incidence of high beta hydroxybutyrate, low bicarbonate (BIC), high acyl carnitine, low selenium, low magnesium, low zinc, low phosphorus, in a cohort of supplemented patients treated with the ketogenic diet (KD) for medically intractable epilepsy. To analyze effect of age, duration of exposure to KD, type of KD, and route of KD intake on lab abnormalities. To analyze the incidence of clinically actionable results, resulting in medical interventions based on abnormal results and to analyze costs of testing.Methods: Retrospective chart review and statistical analysis. Association between abnormal values (binary) and categorical variables was tested with Chi-square/Fisher’s exact test. Associations between abnormal values (binary) and continuous variables were analyzed with logistic regression. Statistical analyses were performed in SAS 9.4.Results: We included 91 patients with average duration on diet of 46.73 months (IQR 18.8–75.5 months). Most patients were on the classic KD (81 KD- 59% on 4:1 ratio, 10 modified Atkins diet). 74% were orally fed and 70% completed lab visits to the 12-month mark. There was no significant association between abnormal laboratory parameters and duration of exposure, type of diet, route of administration. Younger children were more likely to have low BIC, high acyl carnitine. Older children were more likely to have low phosphorus. Less than 15% of patients reported clinical changes to suggest dietary deficiency in vitamins/ minerals and in < 11% of cases was an actionable laboratory parameter found.Significance: Our study is the first to document the real-life incidence of selected tests being abnormal when following consensus guidelines on lab testing. Elimination of tests with low yield will result in cost savings of up to $USD 185 per visit. Low phosphorus is frequently found in patients on KD.

An Integrated Understanding of the Molecular Mechanisms of How Adipose Tissue Metabolism Affects Long-term Body Weight Maintenance.

Lifestyle-based weight loss interventions frequently demonstrate long-term inefficiency and weight regain. Identification of underlying mechanisms and predictors to identify subjects who will benefit from lifestyle-based weight loss strategies is urgently required. We analyzed 143 adults of the randomized Maintain trial (Maintain-Adults) after intended weight loss to identify mechanisms contributing to the regulation of body weight maintenance. Unbiased RNA sequencing of adipose and skeletal muscle biopsies revealed fatty acid metabolism as a key pathway modified by weight loss. Variability of key enzymes of this pathway, estimates of substrate oxidation, and specific serum acylcarnitine (AC) species, representing a systemic snapshot of in vivo substrate flux, predicted body weight maintenance (defined as continuous or dichotomized [< or ≥3% weight regain] variable) 18 months after intended weight loss in the entire cohort. Key results were confirmed in a similar randomized controlled trial in 137 children and adolescents (Maintain-Children), which investigated the same paradigm in a pediatric cohort. These data suggest that adaption of lipid utilization in response to negative energy balance contributes to subsequent weight maintenance. Particularly a functional role for circulating ACs, which have been suggested to reflect intracellular substrate utilization, as mediators between peripheral energy stores and control of long-term energy homeostasis was indicated.

Screening and SLC22A5 gene mutations of the patients with primary carnitine deficiency

Objective To investigate the clinical features and SLC22A5 gene mutation types in patients with primary carnitine deficiency(PCD). Methods The free carnitine(C0) and acylcarnitine levels in the blood of 210 908 neonates from newborn screening program and 576 children with suspected clinical inherited metabolic diseases were measured by using liquid chromatography tandem mass spectrometry method during September 2015 to December 2017, after that the SLC22A5 gene mutations were analyzed in the children with low C0 level and the diagnosis was made.The clinical characteristics, laboratory findings, genotypes, treatment and prognosis were retrospectively analyzed in patients.Paired sample t test was used to compare the biochemical indexes of patients before and after the treatments. Results Ten children were diagnosed with PCD(9 cases from newborn screening program, 1 case from clinical patients), and 7 children were diagnosed with maternal carnitine deficiency.After treatment with oral Levocarnitine, the free carnitine and acylcarnitine of the patients returned to the normal levels.The clinical symptoms disappeared in 1 patient out of clinical patients, and the other 16 patients from newborn screening program were asymptomatic and showed normal growth and development.Seventeen patients got genetic analysis, and 10 types of mutations were found, including c. 1400C>G, c.1462C>T, c.797C>T, c.95A>G, c.92C>T, c.1093A>C, c.761G>A, c.865C>T, c.428C>T, c.1195C>T, among which two of them (c.1093A>C and c. 92C>T) were novel mutations.The most common mutation of SLC22A5 gene was c. 1400C>G. Conclusions Liquid chromatography tandem mass spectrometry technology is sufficient to screen newborns and maternal carnitine deficiency, and the c. 1400C>G mutation is found at the highest frequency in Xuzhou area.If patients receive early treatment, they may have a good prognosis. Key words: Primary carnitine deficiency; Tandem mass spectrometry; Free carnitine; SLC22A5 gene

Three siblings with neuronal ceroid lipofuscinosis type 7 and 2 novel mutations in their MFSD8 gene

Objective The neuronal ceroid lipofuscinosis (CLN) are a group of severe lysosomal storage diseases.The patients present with clinically and genetically heterogeneous neurodegenerative disorders.This study aims to investigate the clinical characteristics and the gene mutations of a rare Chinese family with 3 siblings affected by CLN7. Methods The proband, a 5-year-old girl, visited us because of intermittently seizures and mental retardation for 2 years and a half in December, 2015.Clinical investigation, brain magnetic resonance imaging(MRI), biochemical and the gene analysis were performed for the etiological study. Results The proband had seizures at the age of 2 and a half years, with the progressive motor deterioration, speech disturbance, mental regression and vision loss.Her brain MRI showed diffusive cerebral atrophy.The blood aminoacids, acylcarnitine and urine organic acid profiles were normal.Lysosomal palmitoyl protein thioesterase and tripeptidyl peptidase activities of peripheral leukocytes were normal.A compound heterozygous mutation of c. 1351-1G>A and c. 300T>G was detected on her MFSD8 gene, supporting the diagnosis of CLN7.Both of the 2 mutations were novel.Each of her parents carried one of the mutations.Two brothers of the proband had similar clinical process.Her elder brother died at the age of 7 due to severe encephalopathy of unknown etiology.The younger brother showed dyskinesia from the age of 2 years and seizures from the age of 4 years.A compound heterozygous mutation on MFSD8 gene, c.1351-1G>A and c. 300T>G, was found from the younger brother, as same as the proband. Conclusions CLN7 is a rare disorder of CLN.In this study, the diagnosis of the 3 siblings with similar clinical process were much delayed.Gene analysis was key for the diagnosis.Two novel mutations were found on MFSD8 of the family.There is still no effective treatment for neurol ceroid lipofuscinosis.The prognosis is poor.Based on the mutation diagnosis, prenatal diagnosis for the next sibling is possible to the prevention of the disease. Key words: Neuronal ceroid lipofuscinosis; Neurodegenerative disorders; Lysosomal storage diseases; MFSD8 gene

Acylcarnitine profiles in serum and muscle of dairy cows receiving conjugated linoleic acids or a control fat supplement during early lactation

Acylcarnitines (ACC) are formed when fatty acid (FA)-coenzyme A enters the mitochondria for β-oxidation and the tricarboxylic acid cycle through the carnitine shuttle. Concentrations of ACC may vary depending on the metabolic conditions, but can accumulate when rates of β-oxidation exceed those of tricarboxylic acid. This study aimed to characterize muscle and blood serum acylcarnitine profiles, to determine the mRNA abundance of muscle carnitine acyltransferases, and to test whether dietary supplementation (from d 1 in milk) with conjugated linoleic acids (CLA; 100 g/d; each 12% of trans-10,cis-12 and cis-9,trans-11 CLA; n = 11) altered these compared with control fat-supplemented cows (CTR; n = 10). Blood samples and biopsies from the semitendinosus musclewere collected on d -21, 1, 21, and 70 relative to parturition. Serum and muscle ACC profiles were quantified using a targeted metabolomics approach. The CLA supplement did not affect the variables examined. The serum concentration of free carnitine decreased with the onset of lactation. The concentrations of acetylcarnitine, hydroxybutyrylcarnitine, and the sum of short-chain ACC in serum were greater from d -21 to 21 than thereafter. The serum concentrations of long-chain ACC tetradecenoylcarnitine (C14:1) and octadecenoylcarnitine (C18:1) concentrations were greater on d 1 and 21 compared with d -21. Muscle carnitine remained unchanged, whereas short- and medium-chain ACC, including propenoylcarnitine (C3:1), hydroxybutyrylcarnitine, hydroxyhexanoylcarnitine, hexenoylcarnitine (C6:1), and pimelylcarnitine were increased on d 21 compared with d -21 and decreased thereafter. In muscle, the concentrations of long-chain ACC (from C14 to C18) were elevated on d 1. The mRNA abundance of carnitine palmitoyltransferase 1, muscle isoform (CPT1B) increased 2.8-fold from d -21 to 1, followed by a decline to nearly prepartum values by d 70, whereas that of CPT2 did not change over time. The majority of serum and muscle short- and long-chain ACC were positively correlated with the FA concentrations in serum, whereas serum carnitine and C5 were negatively correlated with FA. Time-related changes in the serum and muscle ACC profiles were demonstrated that were not affected by the CLA supplement at the dosage used in the present study. The elevated concentrations of long-chain ACC species in muscle and of serum acetylcarnitine around parturition point to incomplete FA oxidation were likely due to insufficient metabolic adaptation in response to the load of FA around parturition.

Metabolomics identifies increases in the acylcarnitine profiles in the plasma of overweight subjects in response to mild weight loss: a randomized, controlled design study.

BackgroundUsing metabolomics technique to analyze the response to a dietary intervention generates valuable information concerning the effects of the prescribed diet on metabolic regulation. To determine whether low calorie diet (LCD)-induced weight reduction causes changes in plasma metabolites and metabolic characteristics.MethodsOverweight subjects consumed a LCD (n = 47) or a weight maintenance diet (control, n = 50) in a randomized, controlled design study with a 12-week clinical intervention period. Plasma samples were analyzed using an UPLC-LTQ-Orbitrap MS.ResultsThe 12-week LCD intervention resulted in significant mild weight loss, with an 8.3% and 10.6% reduction observed in the visceral fat area (VFA) at the level of the lumbar vertebrae L1 and L4, respectively. The LCD group showed a significant increase in the mean change of serum free fatty acids compared to the control group. In the LCD group, we observed a significant increase in the acylcarnitine (AC) levels, including hexanoylcarnitine, L-octanoylcarnitine, 9-decenoylcarnitine, trans-2-dodecenoylcanitine, dodecanoylcarnitine, 3,5-tetradecadiencarnitine, cis-5-tetradecenoylcarnitine, 9,12-hexadecadienoylcarnitine, and 9-hexadecenoylcarnitne at the 12-week follow-up assessment. When the plasma metabolite changes from baseline were compared between the control and LCD groups, the LCD group showed significant increases in hexanoylcarnitine, L-octanoylcarnitine, trans-2-dodecenoylcanitine, and 3,5-tetradecadiencarnitine than the control group. Additionally, the changes in these ACs in the LCD group strongly negatively correlated with the changes in the VFA at L1 and/or L4.ConclusionMild weight loss from 12-week calorie restriction increased the plasma levels of medium- and long-chain ACs. These changes were coupled with a decrease in VFA and an increase in free fatty acids.Trial registrationNCT03135132; April 26, 2017.

The Carnitine Shuttle Pathway is Altered in Patients With Neovascular Age-Related Macular Degeneration.

PurposeTo identify metabolites and metabolic pathways altered in neovascular age-related macular degeneration (NVAMD).MethodsWe performed metabolomics analysis using high-resolution C18 liquid chromatography-mass spectrometry on plasma samples from 100 NVAMD patients and 192 controls. Data for mass/charge ratio ranging from 85 to 850 were captured, and metabolic features were extracted using xMSanalyzer. Nested feature selection was used to identify metabolites that discriminated between NVAMD patients and controls. Pathway analysis was performed with Mummichog 2.0. Hierarchical clustering was used to examine the relationship between the discriminating metabolites and NVAMD patients and controls.ResultsOf the 10,917 metabolic features analyzed, a set of 159 was identified that distinguished NVAMD patients from controls (area under the curve of 0.83). Of these features, 39 were annotated with confidence and included multiple carnitine metabolites. Pathway analysis revealed that the carnitine shuttle pathway was significantly altered in NVAMD patients (P = 0.0001). Tandem mass spectrometry confirmed the molecular identity of five carnitine shuttle pathway acylcarnitine intermediates that were increased in NVAMD patients. Hierarchical cluster analysis revealed that 51% of the NVAMD patients had similar metabolic profiles, whereas the remaining 49% displayed greater variability in their metabolic profiles.ConclusionsMultiple long-chain acylcarnitines that are part of the carnitine shuttle pathway were significantly increased in NVAMD patients compared to controls, suggesting that fatty acid metabolism may be involved in NVAMD pathophysiology. Cluster analysis suggested that clinically indistinguishable NVAMD patients can be separated into distinct subgroups based on metabolic profiles.

Abstract P167: Altered Gut Microbiome Contributes to Metabolite Biomarkers in Patients With Pulmonary Hypertension

Objectives: Pulmonary arterial hypertension (PAH) is a cardiopulmonary disease without effective cure. The objective of this study is to test the hypothesis that PAH patients have a distinct gut microbiome composition acting as a driving force for the increased PAH metabolic biomarkers, acyl carnitines and urate. Methods: Fecal samples from 18 type 1 PAH patients (mean pulmonary arterial pressure [mPAP] 57.4±16.7 mmHg) and 13 reference subjects in Brazil were collected for comparison of microbiome using shotgun metagenomics. Plasma samples from 33 type I PAH patients (mPAP 51.7± 13.5 mmHg) and 19 reference subjects in the USA were used for untargeted metabolomic analysis. Results: More than 80 bacterial taxa were differentially enriched in the microbiomes of the PAH cohort. Random forest machine-learning algorithm predicted PAH patients with 82.4% accuracy from their gut microbiome composition. The most increased taxa in the PAH microbiome were trimethylamine (TMA) producing bacteria like Collinsella (P=0.0037). The PAH metabolome also showed increases of gut microbiome-derived short chain acyl carnitines like isubutyrylcarnitine (P=0.010) and valerylcarnitine (P=0.030), which are the precursors of TMA. In addition, increased urate (P=0.0004) and allantoin (P=0.027) in PAH plasma correlated with significantly increased enzymes producing urate in the PAH microbiome (purine metabolism (P=0.017) and xanthine oxidase (P&lt;0.05)). Conclusion: These findings suggest that the random forest modeling of the gut microbiome composition can be used for prediction of PAH and that the unique gut microbiome of PAH influences acyl carnitines and urate metabolism to contribute to pathophysiology.

Efecto del nivel de complementación con Metionina-Colina en vacas Holstein durante el periodo de transición sobre las concentraciones hepáticas de triglicéridos, colina y carnitina

Con el objetivo de evaluar el potencial lipotrópico de metionina-colina en vacas lecheras durante el periodo de transición, dosis de 20 g/d de una Fuente Comercial Protegida de la Degradación Ruminal (FCPDR) de metionina, y sus combinaciones con una FCPDR de colina en dosis de 60 y 120 g/d fueron suministradas a vacas entre el día 260 de gestación y el día 20 posparto. Estas pastoreaban kikuyo (Cenchrus clamdestinum) y recibieron un complemento alimenticio. El día 270 de gestación y a los días 10 y 20 posparto se cuantificaron las concentraciones plasmáticas de Ácidos Grasos No Esterificados (AGNES), β-Hidroxibutirato (BHB) y Triglicéridos (TG), así como las concentraciones hepáticas de triacilglicéridos, de colina, carnitina total, carnitina libre y acil carnitina. Durante el preparto se presentaron los valores significativamente más altos (p &lt; 0.05) de TG plasmáticos y los valores significativamente más bajos (p &lt; 0.05) de AGNES y BHB. Las concentraciones hepáticas de TG, de colina y de las diferentes formas de carnitina no difirieron significativamente entre periodos de muestreo y no se vieron afectadas por la suplementación con metionina-colina. Las concentraciones plasmáticas de BHB aumentaron significativamente (p &lt; 0.05) con la suplementación conjunta con metionina y colina, sugiriendo un aumento en la oxidación de ácidos grasos. Se concluye que con concentraciones bajas de AGNES, la metionina y colina no son nutrientes limitantes para la exportación de TG desde el hígado a la sangre. Bajo esta condición no se observó lipidosis hepática y como consecuencia la suplementación con metionina-colina no ocasionó efectos significativos sobre las concentraciones hepáticas de TG.

CblC Type Methylmalonic Aciduria with a Novel Homozygous Mutation: A Case Report

Background CombinedMethylmalonic Aciduria (MMA), and homocystinuria CblC type is the most common inborn error of cobalamin metabolism with 77 mutations identified till date in the MMACHC gene. The disease has early and late presentations with varied clinical features. Case report A pair of preterm monochorionic twins was born to non-consanguineous parents with history of 2 previous infant deaths with suspected MMA. The twins became symptomatic in second week with severe neutropenia, thrombocytopenia, progressive encephalopathy and eczema without anemia, metabolic acidosis or hyperammonemia. Investigation revealed elevated plasma Complement 3 (C3) acyl carnitine and very high MMA levels in urine. Genetic testing revealed a novel large deletion mutation in chromosome 1 which comprised of the whole MMACHC gene confirming the diagnosis of CblC type of MMA. The mutation was homozygous despite parents being unrelated and was identified in both parents later. Both twins responded transiently to treatment with hydroxycobalamin. Conclusion Large deletion in the MMACHC genewhich was identified in a homozygous state in our twins is previously unreported. The phenotypic features are described.

The metabolic fate of fenclozic acid in chimeric mice with a humanized liver

The metabolic fate of the human hepatotoxin fenclozic acid ([2-(4-chlorophenyl)-1,3-thiazol-4-yl]acetic acid) (Myalex) was studied in normal and bile-cannulated chimeric mice with a humanized liver, following oral administration of 10 mg/kg. This in vivo animal model was investigated to assess its utility to study “human” metabolism of fenclozic acid, and in particular to explore the formation of electrophilic reactive metabolites (RMs), potentially unique to humans. Metabolism was extensive, particularly involving the carboxylic acid-containing side chain. Metabolism resulted in the formation of a large number of metabolites and involved biotransformation via both oxidative and conjugative routes. The oxidative metabolites detected included a variety of hydroxylations as well as cysteinyl-, N-acetylcysteinyl-, and cysteinylglycine metabolites. The latter resulted from the formation of glutathione adducts/conjugates providing evidence for the production of RMs. The production of other classes of RMs included acyl-glucuronides, and the biosynthesis of acyl carnitine, taurine, glutamine, and glycine conjugates via potentially reactive acyl-CoA intermediates was also demonstrated. A number of unique “human” metabolites, e.g., those providing evidence for side-chain extension, were detected in the plasma and excreta of the chimeric liver-humanized mice that were not previously characterised in, e.g., the excreta of rat and C57BL/6 mice. The different pattern of metabolism seen in these chimeric mice with a humanized liver compared to the conventional rodents may offer clues to the factors that contributed to the drug-induced liver injury seen in humans.

Alterations in plasma acylcarnitine and amino acid profiles may indicate poor nutrition during the suckling period due to maternal intake of an unbalanced diet and may predict later metabolic dysfunction.

Plasma profiles of acylcarnitines (ACs) and amino acids (AAs) may have interest as potential biomarkers. Here we analyzed plasma AC and AA profiles in 2 rat models with different metabolic programming outcomes: offspring of dams fed a cafeteria diet during lactation (O-CAF, with a thin-outside-fat-inside phenotype) and the offspring of dams with diet-induced obesity subjected to dietary normalization before gestation [offspring of postcafeteria dams (O-PCaf), nonaltered phenotype]. The purpose was to identify early variables that might indicate a propensity for a dysmetabolic state. O-CAF rats presented higher circulating levels of most of the lipid-derived ACs and higher hepatic expression of genes related to fatty acid oxidation ( Ppara and Cpt1a) than controls [offspring of control dams (O-C)]. They also exhibited an altered plasma AA profile. These differences were not observed in O-PCaf animals. A partial least squares-discriminant analysis score plot of the metabolomics data showed a clear separation between O-CAF and O-C animals. The long-chain ACs (C18, C18:1, C18:2, C16:1, and C16DC) and the AAs glycine, alanine, isoleucine, serine, and proline are the variables mainly influencing this separation. In summary, we have identified a cluster of ACs and AAs whose alterations may indicate poor nutrition during lactation due to maternal unbalanced diet intake and predict the later dysmetabolic phenotype observed in the offspring.-Pomar, C. A., Kuda, O., Kopecky, J., Rombaldova, M., Castro, H., Picó, C., Sánchez, J., Palou, A. Alterations in plasma acylcarnitine and amino acid profiles may indicate poor nutrition during the suckling period due to maternal intake of an unbalanced diet and may predict later metabolic dysfunction.

Improving Mitochondrial Function Improves the Plasma Metabolite Profile in Experimental Heart Failure

Background We recently reported a strong association of plasma metabolite profile with survival in patients with heart failure and reduced ejection fraction (HFrEF). Mitochondrial function is perturbed in HFrEF, but whether plasma metabolite levels are linked to mitochondrial dysfunction is unknown. Elamipretide, a 4 amino acid peptide, normalizes mitochondrial energy production and thus provides a tool to test the association of mitochondrial function with the plasma metabolome in HFrEF. Methods Dogs (n=14) underwent intracoronary micro-embolization to induce HFrEF (pre-treatment EF 35%) and then were randomized 1:1 to elamipretide or placebo for 3 months. Targeted plasma metabolomic profiling was performed to quantitate 8 organic acids (OA), 23 amino acids (AA), and up to 59 acylcarnitines (AC) at pre-treatment and end of study. The association of changes in metabolite levels with treatment were tested using the Wilcoxon rank sum test on the principal components (PC) of each of the three metabolite classes. We also tested the correlation of metabolite levels with mitochondrial maximal rate of ATP synthesis in HF dog myocardium. We then attempted to confirm associations of interest in a human HFrEF cohort (n=1060) using bivariate Cox models. Result There was no association of plasma AA or AC changes with elamipretide treatment. However, there was a near-significant association of the first PC of OA changes (p=0.073), with treatment leading to lower plasma levels of OA compared to placebo (Figure). The OA also trended towards inverse relationship to maximal rate of ATP synthesis in dogs (correlation coef -0.09 to -0.67, mean -0.29), pyruvate having the strongest association (Coef =-0.67, p=0.012). In humans with HFrEF, directionally congruent and statistically significant associations with mortality risk were seen for 6 of these 8 OA (Table). Conclusion In dogs with HFrEF improving mitochondrial function using elamipretide resulted in favorable changes in plasma metabolites, specifically OA, which were risk-associated in human HFrEF. Our data suggest that mitochondrial dysfunction is the mechanism linking these plasma metabolomic abnormalities with worse survival in HFrEF.

Metabolite profiling of plasma in patients with ossification of the posterior longitudinal ligament

BackgroundMetabolomics is one of the “omics” technologies, and is a comprehensive analysis of small molecule metabolites which include amino acid, nucleotides, carbohydrates and fatty acid. The purpose of the present study was to compare the differences of metabolite profiling between patients with ossification of the posterior longitudinal ligament (OPLL) and control subjects. MethodsWe analyzed plasma metabolites in patients with cervical OPLL (n = 10) and in control subjects (n = 10). Ionic metabolites were analyzed using capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS) and lipophilic metabolites were analyzed using liquid chromatograph time-of-flight mass spectrometry (LC-TOFMS). ResultsA total of 259 metabolites (144 metabolites in CE-TOFMS and 115 metabolites in LC-TOFMS) were detected. Among the 259 metabolites, six metabolites, namely acylcarnitine (AC) (14:0), palmitoylcarnitine, AC (18:2), fatty acid (FA) (24:2), thyroxine, thiaproline were significantly larger in OPLL group, even in analyzes excluding patients with diabetes mellitus and hyperlipidemia. ConclusionsWe examined the metabolite profiling in patients with OPLL for the first time and detected six metabolites showing suggestive association with disease. These results of the present study could lead to new insights into clarifying the molecular pathomechanisms of OPLL.

Profiling of Lipidomics Before and After Antipsychotic Treatment in First-Episode Psychosis

Alterations in complex lipids may be involved in pathophysiology of schizophrenia spectrum disorders. In our previous study, we demonstrated importance of detecting lipid metabolism dysregulation by acylcarnitine (ACs) profile analysis in patients with first-episode psychosis (FEP). Here we adopt lipidomics to identify serum glycerophospholipids (GPLs), and sphingomyelins (SMs) for describing FEP status before and after 7 months antipsychotic treatment. Using mass spectrometry and liquid chromatography technique, we profiled 105 individual lipids [14 lysophosphatidylcholines (lysoPCs), 76 phosphatidylcholines (PCs), and 15 sphingomyelins (SMs)] in serum samples from 53 antipsychotic-naive FEP patients, 44 of them were studied longitudinally and from 37 control subjects (CSs). Among the identified and quantified metabolites one lysoPC was elevated, and contrary the levels of 16 PCs as well as the level of one SM were significantly (p≤0.0005) reduced in antipsychotic-naive FEP patients when compared to CSs. Comparison of serum lipids profiles of FEP patients before and after 7-month antipsychotic treatment revealed that 11 GPLs (2 Lyso-PCs, 9 PCs), and 2 SMs were found to be significantly changed (p≤0.0005) in which GPLs were up-regulated, and SMs were down-regulated. However, no significant differences were noted when treated patient's serum lipid profiles were compared with CSs. Our findings suggest that complex lipids profile abnormalities are specifically associated with FEP and these discrepancies reflect two different disease-related pathways. Our findings also provide insight into lipidomic information that may be used for monitoring FEP status and impact of the treatment in the early stage of the schizophrenia spectrum disorder. Funding Statement: This research was supported by the European Union through the European Regional Development Fund (Project No. 2014-2020.4.01.15-0012), and grants from the Estonian Research Foundation (IUT 20-41, IUT 20-42) Declaration of Interests: There are no relevant conflict of interest from any of the authors. Ethics Approval Statement: All subjects gave written informed consent in accordance with the Declaration of Helsinki. The protocol was approved by the Ethics Review Committee on Human Research of the University of Tartu (Estonia).

Study of acylcarnitine and amino acid profiles in hyperammonemia pediatric patients

Objective The aim of this study was to study amino acid and acylcarnitine profiles in Egyptian pediatric patients with hyperammonemia using high-performance liquid chromatography (HPLC). Background Hyperammonemia is a life-threatening problem during childhood that requires prompt intervention. Emerging metabolomics such as amino acid and acylcarnitine assay provide a powerful platform for discovering new biomarkers to improve early diagnosis. Patients and methods A total of 110 pediatric patients were enrolled in this study: 40 patients with hyperammonemia suspected as having an inborn error of metabolism, 20 hyperammonemia patients suspected as having hepatic disorders, and 50 apparently healthy children who served as the control group. Routine laboratory investigations were carried out for all participants (blood ammonia, liver function tests, kidney function tests, and arterial blood gas analysis). Amino acid and acylcarnitine profiles were measured quantitatively for all participants using HPLC. Results Fourteen metabolites were supposed to be ‘potential metabolite markers’ for differentiation between patients with hyperammonemia due to inborn error of metabolism and those with hyperammonemia due to hepatic causes. Seven of these metabolites were amino acids (Gly : Ala, Leu-Ile, Leu : Phe, Met : Phe, methionine, tyrosine, and valine), and seven were acylcarnitines (C3, C3 : C2, C5-DC, C10 : C1, C16-OH, C18, and C14-carnitines). Conclusion Acylcarnitine and amino acid profiles detected using HPLC could be potential noninvasive diagnostic biomarkers for differentiation of hyperammonemia cases.