Publications by authors named "Teodoro Bottiglieri"

145 Publications

Moderate Folic Acid Supplementation in Pregnant Mice Results in Altered Methyl Metabolism and in Sex-Specific Placental Transcription Changes.

Mol Nutr Food Res 2021 May 19:e2100197. Epub 2021 May 19.

Departments of Human Genetics and Pediatrics, McGill University Health Center (MUHC), McGill University, Montreal, Canada.

Scope: Many pregnant women have higher folic acid (FA) intake due to food fortification and increased vitamin use. It is reported that diets containing five-fold higher FA than recommended for mice (5xFASD) during pregnancy resulted in methylenetetrahydrofolate reductase (MTHFR) deficiency and altered choline/methyl metabolism, with neurobehavioral abnormalities in newborns. The goal is to determine whether these changes have their origins in the placenta during embryonic development.

Methods And Results: Female mice are fed control diet or 5xFASD for a month before mating and maintained on these diets until embryonic day 17.5. 5xFASD led to pseudo-MTHFR deficiency in maternal liver and altered choline/methyl metabolites in maternal plasma (increased methyltetrahydrofolate and decreased betaine). Methylation potential (S-adenosylmethionine:S-adenosylhomocysteine ratio) and glycerophosphocholine are decreased in placenta and embryonic liver. Folic acid supplemented diet results in sex-specific transcriptome profiles in placenta, with validation of dietary expression changes of 29 genes involved in angiogenesis, receptor biology or neurodevelopment, and altered methylation of the serotonin receptor 2A gene.

Conclusion: Moderate increases in folate intake during pregnancy result in placental metabolic and gene expression changes, particularly in angiogenesis, which may contribute to abnormal behavior in pups. These results are relevant for determining a safe upper limit for folate intake during pregnancy.
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http://dx.doi.org/10.1002/mnfr.202100197DOI Listing
May 2021

Analysis of differential neonatal lethality in cystathionine β-synthase deficient mouse models using metabolic profiling.

FASEB J 2021 Jun;35(6):e21629

Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, PA, USA.

Cystathionine beta-synthase (CBS) is a key enzyme of the trans-sulfuration pathway that converts homocysteine to cystathionine. Loss of CBS activity due to mutation results in CBS deficiency, an inborn error of metabolism characterized by extreme elevation of plasma total homocysteine (tHcy). C57BL6 mice containing either a homozygous null mutation in the cystathionine β-synthase (Cbs ) gene or an inactive human CBS protein (Tg-G307S Cbs ) are born in mendelian numbers, but the vast majority die between 18 and 21 days of age due to liver failure. However, adult Cbs null mice that express a hypomorphic allele of human CBS as a transgene (Tg-I278T Cbs ) show almost no neonatal lethality despite having serum tHcy levels similar to mice with no CBS activity. Here, we characterize liver and serum metabolites in neonatal Cbs , Tg-G307S Cbs , and Tg-I278T Cbs mice at 6, 10, and 17 days of age to understand this difference. In serum, we observe similar elevations in tHcy in both Tg-G307S Cbs and Tg-I278T Cbs compared to control animals, but methionine is much more severely elevated in Tg-G307S Cbs mice. Large scale metabolomic analysis of liver tissue confirms that both methionine and methionine-sulfoxide are significantly more elevated in Tg-G307S Cbs animals, along with significant differences in several other metabolites including hexoses, amino acids, other amines, lipids, and carboxylic acids. Our data are consistent with a model that the neonatal lethality observed in CBS-null mice is driven by excess methionine resulting in increased stress on a variety of related pathways including the urea cycle, TCA cycle, gluconeogenesis, and phosphatidylcholine biosynthesis.
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http://dx.doi.org/10.1096/fj.202100302RDOI Listing
June 2021

High Intakes of [6S]-5-Methyltetrahydrofolic Acid Compared with Folic Acid during Pregnancy Programs Central and Peripheral Mechanisms Favouring Increased Food Intake and Body Weight of Mature Female Offspring.

Nutrients 2021 Apr 27;13(5). Epub 2021 Apr 27.

Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada.

Supplementation with [6S]-5-methyltetrahydrofolic acid (MTHF) is recommended as an alternative to folic acid (FA) in prenatal supplements. This study compared equimolar gestational FA and MTHF diets on energy regulation of female offspring. Wistar rats were fed an AIN-93G diet with recommended (2 mg/kg diet) or 5-fold (5X) intakes of MTHF or FA. At weaning, female offspring were fed a 45% fat diet until 19 weeks. The 5X-MTHF offspring had higher body weight (>15%), food intake (8%), light-cycle energy expenditure, and lower activity compared to 5X-FA offspring ( 0.05). Both the 5X offspring had higher plasma levels of the anorectic hormone leptin at birth (60%) and at 19 weeks (40%), and lower liver weight and total liver lipids compared to the 1X offspring ( 0.05). Hypothalamic mRNA expression of leptin receptor () was lower, and of suppressor of cytokine signaling-3 () was higher in the 5X-MTHF offspring ( 0.05), suggesting central leptin dysregulation. In contrast, the 5X-FA offspring had higher expression of genes encoding for dopamine and GABA- neurotransmitter receptors ( 0.01), consistent with their phenotype and reduced food intake. When fed folate diets at the requirement level, no differences were found due to form in the offspring. We conclude that MTHF compared to FA consumed at high levels in the gestational diets program central and peripheral mechanisms to favour increased weight gain in the offspring. These pre-clinical findings caution against high gestational intakes of folates of either form and encourage clinical trials examining their long-term health effects when consumed during pregnancy.
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http://dx.doi.org/10.3390/nu13051477DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8146511PMC
April 2021

Increasing breast milk betaine modulates abundance in mammalian neonates and improves long-term metabolic health.

Sci Transl Med 2021 Mar;13(587)

Endocrinology Department, Institut de Recerca Sant Joan de Déu, 08950 Barcelona, Spain.

Accelerated postnatal growth is a potentially modifiable risk factor for future obesity. To study how specific breast milk components contribute to early growth and obesity risk, we quantified one-carbon metabolism-related metabolites in human breast milk and found an inverse association between milk betaine content and infant growth. This association was replicated in an independent and geographically distinct cohort. To determine the potential role of milk betaine in modulating offspring obesity risk, we performed maternal betaine supplementation experiments in mice. Higher betaine intake during lactation increased milk betaine content in dams and led to lower adiposity and improved glucose homeostasis throughout adulthood in mouse offspring. These effects were accompanied by a transient increase in spp. abundance in the gut during early life and a long-lasting increase in intestinal goblet cell number. The link between breast milk betaine and abundance in the gut was also observed in humans, as infants exposed to higher milk betaine content during breastfeeding showed higher fecal abundance. Furthermore, administration of to mouse pups during the lactation period partially replicated the effects of maternal breast milk betaine, including increased intestinal goblet cell number, lower adiposity, and improved glucose homeostasis during adulthood. These data demonstrate a link between breast milk betaine content and long-term metabolic health of offspring.
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http://dx.doi.org/10.1126/scitranslmed.abb0322DOI Listing
March 2021

Choline and Folic Acid in Diets Consumed during Pregnancy Interact to Program Food Intake and Metabolic Regulation of Male Wistar Rat Offspring.

J Nutr 2021 Apr;151(4):857-865

Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada.

Background: North American women consume high folic acid (FA), but most are not meeting the adequate intakes for choline. High-FA gestational diets induce an obesogenic phenotype in rat offspring. It is unclear if imbalances between FA and other methyl-nutrients (i.e., choline) account for these effects.

Objective: This study investigated the interaction of choline and FA in gestational diets on food intake, body weight, one-carbon metabolism, and hypothalamic gene expression in male Wistar rat offspring.

Methods: Pregnant Wistar rats were fed an AIN-93G diet with recommended choline and FA [RCRF; 1-fold, control] or high (5-fold) FA with choline at 0.5-fold [low choline and high folic acid (LCHF)], 1-fold [recommended choline and high folic acid (RCHF)], or 2.5-fold [high choline and high folic acid (HCHF)]. Male offspring were weaned to an RCRF diet for 20 wk. Food intake, weight gain, plasma energy-regulatory hormones, brain and plasma one-carbon metabolites, and RNA sequencing (RNA-seq) in pup hypothalamuses were assessed.

Results: Adult offspring from LCHF and RCHF, but not HCHF, gestational diets had 10% higher food intake and weight gain than controls (P < 0.01). HCHF newborn pups had lower plasma insulin and leptin compared with LCHF and RCHF pups (P < 0.05), respectively. Pup brain choline (P < 0.05) and betaine (P < 0.01) were 22-33% higher in HCHF pups compared with LCHF pups; methionine was ∼23% lower after all high FA diets compared with RCRF (P < 0.01). LCHF adult offspring had lower brain choline (P < 0.05) than all groups and lower plasma 5-methyltetrahydrofolate (P < 0.05) than RCRF and RCHF groups. HCHF adult offspring had lower plasma cystathionine (P < 0.05) than LCHF adult offspring and lower homocysteine (P < 0.01) than RCHF and RCRF adult offspring. RNA-seq identified 144 differentially expressed genes in the hypothalamus of HCHF newborns compared with controls.

Conclusions: Increased choline in gestational diets modified the programming effects of high FA on long-term food intake regulation, plasma energy-regulatory hormones, one-carbon metabolism, and hypothalamic gene expression in male Wistar rat offspring, emphasizing a need for more attention to the choline and FA balance in maternal diets.
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http://dx.doi.org/10.1093/jn/nxaa419DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8030718PMC
April 2021

Preferential accumulation of the active S-(+) isomer in murine retina highlights novel mechanisms of vigabatrin-associated retinal toxicity.

Epilepsy Res 2021 Feb 29;170:106536. Epub 2020 Dec 29.

Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA, USA. Electronic address:

((S)-(+)/(R)-(-)) vigabatrin (Sabril; γ-vinyl GABA), an antiepileptic irreversibly inactivating GABA-transaminase, was administered to male C57Bl6 J mice via continuous infusion (0, 40, 80 mg/kg/d) for 12 days. Our study design pooled retina, eye (minus retina), whole brain and plasma from n = 24 animals for each dose to provide n = 8 triplicates per treatment group. Hypothesizing that (S)-(+) VGB (active isomer) would preferentially accumulate in retina, we determined VGB isomers, comprehensive amino acids, and pharmacokinetic parameters. In brain, eye and plasma, the ((S)-(+)/(R)-(-)) ratio varied from 0.73 to 1.29 and 13.3 in retina, accompanied by a partition coefficient (tissue/plasma, ((S)-(+);(R)-(-))) of 5.8;0.34, 0.63;0.49, and 0.51;0.34 in retina, eye and brain, respectively. Racemic VGB (nmol/g; plasma, nmol/mL, range of means for dose) content was: retina, 25-36; eye (minus retina), 4.8-8.0; brain, 3.1-6.8 and plasma, 8.7-14.9. GABA tissue content (nmol/g) was 1246-3335, 18-64 and 2615-3200 as a function of VGB dose for retina, eye (minus retina) and brain, respectively. The retinal glial cell toxin 2-aminoadipic acid also increased with VGB dose (76-96 nmol/g). Partitioning of active (S)-(+) VGB to retina suggests the involvement of a stereospecific transporter, the identification of which could reveal new therapeutic paradigms that might mitigate VGB's well-known retinal toxicity and expand its clinical utility.
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http://dx.doi.org/10.1016/j.eplepsyres.2020.106536DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7897276PMC
February 2021

[6]-5-Methyltetrahydrofolic Acid and Folic Acid Pregnancy Diets Differentially Program Metabolic Phenotype and Hypothalamic Gene Expression of Wistar Rat Dams Post-Birth.

Nutrients 2020 Dec 25;13(1). Epub 2020 Dec 25.

Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada.

[6]-5-methyltetrahydrofolic acid (MTHF) is a proposed replacement for folic acid (FA) in diets and prenatal supplements. This study compared the effects of these two forms on maternal metabolism and hypothalamic gene expression. Pregnant Wistar rats received an AIN-93G diet with recommended FA (1X, 2 mg/kg, control), 5X-FA or equimolar levels of MTHF. During lactation they received the control diet and then a high fat diet for 19-weeks post-weaning. Body weight, adiposity, food intake, energy expenditure, plasma hormones, folate, and 1-carbon metabolites were measured. RNA-sequencing of the hypothalamus was conducted at parturition. Weight-loss from weaning to 1-week post-weaning was less in dams fed either form of the 5X vs. 1X folate diets, but final weight-gain was higher in 5X-MTHF vs. 5X-FA dams. Both doses of the MTHF diets led to 8% higher food intake and associated with lower plasma leptin at parturition, but higher leptin at 19-weeks and insulin resistance at 1-week post-weaning. RNA-sequencing revealed 279 differentially expressed genes in the hypothalamus in 5X-MTHF vs. 5X-FA dams. These findings indicate that MTHF and FA differ in their programing effects on maternal phenotype, and a potential adverse role of either form when given at the higher doses.
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http://dx.doi.org/10.3390/nu13010048DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7823556PMC
December 2020

Cellular and molecular outcomes of glutamine supplementation in the brain of succinic semialdehyde dehydrogenase-deficient mice.

JIMD Rep 2020 Nov 15;56(1):58-69. Epub 2020 Aug 15.

Department of Pharmacotherapy College of Pharmacy and Pharmaceutical Sciences, Washington State University Spokane Washington USA.

Succinic semialdehyde dehydrogenase deficiency (SSADHD) manifests with low levels of glutamine in the brain, suggesting that central glutamine deficiency contributes to pathogenesis. Recently, we attempted to rescue the disease phenotype of mice, a murine model of SSADHD with dietary glutamine supplementation. No clinical rescue and no central glutamine improvement were observed. Here, we report the results of follow-up studies of the cellular and molecular basis of the resistance of the brain to glutamine supplementation. We first determined if the expression of genes involved in glutamine metabolism was impacted by glutamine feeding. We then searched for changes of brain histology in response to glutamine supplementation, with a focus on astrocytes, known regulators of glutamine synthesis in the brain. Glutamine supplementation significantly modified the expression of glutaminase () (0.6-fold down), glutamine synthetase () (1.5-fold up), and glutamine transporters (solute carrier family 7, member 5 [], 2.5-fold up; , 0.6-fold down). The number of GLUL-labeled cells was greater in the glutamine-supplemented group than in controls ( < .05). Reactive astrogliosis, a hallmark of brain inflammation in SSADHD, was confirmed. We observed a 2-fold stronger astrocyte staining in mutants than in wild-type controls (optical density/cell were 1.8 ± 0.08 in and 0.99 ± 0.06 in ; < .0001), and a 3-fold higher expression of and . However, glutamine supplementation did not improve the histological and molecular signature of astrogliosis. Thus, glutamine supplementation impacts genes implicated in central glutamine homeostasis without improving reactive astrogliosis. The mechanisms underlying glutamine deficiency and its contribution to SSADHD pathogenesis remain unknown and should be the focus of future investigations.
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http://dx.doi.org/10.1002/jmd2.12151DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7653255PMC
November 2020

Novel biomarkers and age-related metabolite correlations in plasma and dried blood spots from patients with succinic semialdehyde dehydrogenase deficiency.

Orphanet J Rare Dis 2020 09 23;15(1):261. Epub 2020 Sep 23.

Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences Building Room 210C, Washington State University, 412 E. Spokane Falls Boulevard, Spokane, WA, 99202-2131, USA.

Background: Previous work has identified age-related negative correlations for γ-hydroxybutyric acid (GHB) and γ-aminobutyric acid (GABA) in plasma of patients with succinic semialdehyde dehydrogenase deficiency (SSADHD). Using plasma and dried blood spots (DBS) collected in an ongoing natural history study, we tested the hypothesis that other biomarkers would follow a similar age-related negative correlation as seen for GHB/GABA. Samples (mixed sex) included: patients (n = 21 unique samples, 1-39.5 yrs) and parallel controls (n = 9 unique samples, 8.4-34.8 yrs). Archival control data (DBS only; n = 171, 0.5-39.9 yrs) was also included.

Results: Metabolites assessed included amino acids (plasma, DBS) and acylcarnitines, creatine, creatinine, and guanidinoacetate (DBS only). Age-related negative correlations for glycine (plasma, DBS) and sarcosine (N-methylglycine, plasma) were detected, accompanied by elevated proline and decreased levels of succinylacetone, argininosuccinate, formaminoglutamate, and creatinine. Significantly low acylcarnitines were detected in patients across all chain lengths (short-, medium- and long-chain). Significant age-dependent positive correlations for selected acylcarnitines (C6-, C12DC(dicarboxylic)-, C16-, C16:1-, C18:1-, C18:2OH-carnitines) were detected in patients and absent in controls. Receiver operating characteristic (ROC) curves for all binary comparisons revealed argininosuccinate and succinylacetone to be the most discriminating biomarkers (area > 0.92).

Conclusions: Age-dependent acylcarnitine correlations may represent metabolic compensation responsive to age-related changes in GHB and GABA. Our study highlights novel biomarkers in SSADHD and expands the metabolic pathophysiology of this rare disorder of GABA metabolism.
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http://dx.doi.org/10.1186/s13023-020-01522-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7510106PMC
September 2020

Relationship of Cerebrospinal Fluid Vitamin B12 Status Markers With Parkinson's Disease Progression.

Mov Disord 2020 08 14;35(8):1466-1471. Epub 2020 May 14.

Department of Pathology and Laboratory Medicine, UC Davis, Sacramento, California, USA.

Background: Using blood specimens from untreated early Parkinson's disease (PD) patients from the DATATOP trial, we found that subjects in the low serum vitamin B12 tertile experienced greater annualized change in ambulatory capacity score, whereas those with moderately elevated (>15 μmol/L) total homocysteine had greater annualized declines in the Mini-Mental State Exam.

Methods: In this this study we sought to determine whether levels of cerebrospinal fluid (CSF) B12 markers were also associated with progression of PD.

Results: The annualized change in the UPDRS "walking" item, a component of the ambulatory capacity score, was worse in the low B12 tertile. No association with change in the Mini-Mental State Exam was seen for those 7% with the highest baseline CSF total homocysteine.

Conclusions: In these untreated early-PD subjects, low CSF B12 predicted greater worsening of the UPDRS "walking" item, whereas CSF total homocysteine was not associated with progression of cognitive impairment. These findings extend and partially support our findings in serum. © 2020 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
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http://dx.doi.org/10.1002/mds.28073DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7496300PMC
August 2020

Impact of the MTHFR C677T polymorphism on one-carbon metabolites: Evidence from a randomised trial of riboflavin supplementation.

Biochimie 2020 Jun 21;173:91-99. Epub 2020 Apr 21.

Nutrition Innovation Centre for Food and Health (NICHE), Ulster University, Cromore Rd, Coleraine, BT52 1SA, Northern Ireland, UK. Electronic address:

Homozygosity for the C677T polymorphism in MTHFR (TT genotype) is associated with a 24-87% increased risk of hypertension. Blood pressure (BP) lowering was previously reported in adults with the TT genotype, in response to supplementation with the MTHFR cofactor, riboflavin. Whether the BP phenotype associated with the polymorphism is related to perturbed one-carbon metabolism is unknown. This study investigated one-carbon metabolites and their responsiveness to riboflavin in adults with the TT genotype. Plasma samples from adults (n 115) screened for the MTHFR genotype, who previously participated in RCTs to lower BP, were analysed for methionine, S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), betaine, choline and cystathionine by liquid chromatography tandem mass spectrometry (LC-MS/MS). The one-carbon metabolite response to riboflavin (1.6 mg/d; n 24) or placebo (n 23) for 16 weeks in adults with the TT genotype was also investigated. Plasma SAM (74.7 ± 21.0 vs 85.2 ± 22.6 nmol/L, P = 0.013) and SAM:SAH ratio (1.66 ± 0.55 vs 1.85 ± 0.51, P = 0.043) were lower and plasma homocysteine was higher (P = 0.043) in TT, compared to CC individuals. In response to riboflavin, SAM (P = 0.008) and cystathionine (P = 0.045) concentrations increased, with no responses in other one-carbon metabolites observed. These findings confirm perturbed one-carbon metabolism in individuals with the MTHFR 677TT genotype, and for the first time demonstrate that SAM, and cystathionine, increase in response to riboflavin supplementation in this genotype group. The genotype-specific, one-carbon metabolite responses to riboflavin intervention observed could offer some insight into the role of this gene-nutrient interaction in blood pressure.
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http://dx.doi.org/10.1016/j.biochi.2020.04.004DOI Listing
June 2020

Correction to: Post-mortem tissue analyses in a patient with succinic semialdehyde dehydrogenase deficiency (SSADHD). I. Metabolomic outcomes.

Metab Brain Dis 2020 06;35(5):849-850

Department of Pharmacotherapy, Health Sciences Building Room, 210C, College of Pharmacy and Pharmaceutical Sciences, Washington State University, 412 E. Spokane Falls Boulevard, Spokane, WA, 99202-2131, USA.

Upon publication, it was noted that five of the on-line supplementary figures had incorrect figure: figure legend associations. These were supplementary Figs. 6, 7, 14, 15, and 23.
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http://dx.doi.org/10.1007/s11011-020-00569-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7228844PMC
June 2020

Post-mortem tissue analyses in a patient with succinic semialdehyde dehydrogenase deficiency (SSADHD). I. Metabolomic outcomes.

Metab Brain Dis 2020 04 14;35(4):601-614. Epub 2020 Mar 14.

Department of Pharmacotherapy, Health Sciences Building Room 210C, College of Pharmacy and Pharmaceutical Sciences, Washington State University, 412 E. Spokane Falls Boulevard, Spokane, WA, 99202-2131, USA.

Metabolomic characterization of post-mortem tissues (frontal and parietal cortices, pons, cerebellum, hippocampus, cerebral cortex, liver and kidney) derived from a 37 y.o. male patient with succinic semialdehyde dehydrogenase deficiency (SSADHD) was performed in conjunction with four parallel series of control tissues. Amino acids, acylcarnitines, guanidino- species (guanidinoacetic acid, creatine, creatinine) and GABA-related intermediates were quantified using UPLC and mass spectrometric methods that included isotopically labeled internal standards. Amino acid analyses revealed significant elevation of aspartic acid and depletion of glutamine in patient tissues. Evidence for disruption of short-chain fatty acid metabolism, manifest as altered C4OH, C5, C5:1, C5DC (dicarboxylic) and C12OH carnitines, was observed. Creatine and guanidinoacetic acids were decreased and elevated, respectively. GABA-associated metabolites (total GABA, γ-hydroxybutyric acid, succinic semialdehyde, 4-guanidinobutyrate, 4,5-dihydroxyhexanoic acid and homocarnosine) were significantly increased in patient tissues, including liver and kidney. The data support disruption of fat, creatine and amino acid metabolism as a component of the pathophysiology of SSADHD, and underscore the observation that metabolites measured in patient physiological fluids provide an unreliable reflection of brain metabolism.
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http://dx.doi.org/10.1007/s11011-020-00550-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7180121PMC
April 2020

Betaine restores epigenetic control and supports neuronal mitochondria in the cuprizone mouse model of multiple sclerosis.

Epigenetics 2020 08 9;15(8):871-886. Epub 2020 Mar 9.

Department of Biological Sciences, School of Biomedical Sciences, Kent State University , Kent, OH, USA.

Methionine metabolism is dysregulated in multiple sclerosis (MS). The methyl donor betaine is depleted in the MS brain where it is linked to changes in levels of histone H3 trimethylated on lysine 4 (H3K4me3) and mitochondrial impairment. We investigated the effects of replacing this depleted betaine in the cuprizone mouse model of MS. Supplementation with betaine restored epigenetic control and alleviated neurological disability in cuprizone mice. Betaine increased the methylation potential (SAM/SAH ratio), levels of H3K4me3, enhanced neuronal respiration, and prevented axonal damage. We show that the methyl donor betaine and the betaine homocysteine methyltransferase (BHMT) enzyme can act in the nucleus to repair epigenetic control and activate neuroprotective transcriptional programmes. ChIP-seq data suggest that BHMT acts on chromatin to increase the SAM/SAH ratio and histone methyltransferase activity locally to increase H3K4me3 and activate gene expression that supports neuronal energetics. These data suggest that the methyl donor betaine may provide neuroprotection in MS where mitochondrial impairment damages axons and causes disability.
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http://dx.doi.org/10.1080/15592294.2020.1735075DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7518703PMC
August 2020

Altered Brain Metabolome Is Associated with Memory Impairment in the rTg4510 Mouse Model of Tauopathy.

Metabolites 2020 Feb 14;10(2). Epub 2020 Feb 14.

Center of Metabolomics, Institute of Metabolic Disease, Baylor Scott & White Research Institute, Dallas, TX 75226, USA.

Alzheimer's disease (AD) is characterized, amongst other features, by the pathologic accumulation of abnormally phosphorylated tau filaments in neurons that lead to neurofibrillary tangles. However, the molecular mechanisms by which the abnormal processing of tau leads to neurodegeneration and cognitive impairment remain unknown. Metabolomic techniques can comprehensively assess disturbances in metabolic pathways that reflect changes downstream from genomic, transcriptomic and proteomic systems. In the present study, we undertook a targeted metabolomic approach to determine a total of 187 prenominated metabolites in brain cortex tissue from wild type and rTg4510 animals (a mice model of tauopathy), in order to establish the association of metabolic pathways with cognitive impairment. This targeted metabolomic approach revealed significant differences in metabolite concentrations of transgenic mice. Brain glutamine, serotonin and sphingomyelin C18:0 were found to be predictors of memory impairment. These findings provide informative data for future research on AD, since some of them agree with pathological alterations observed in diseased humans.
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http://dx.doi.org/10.3390/metabo10020069DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7074477PMC
February 2020

Memantine Protects From Exacerbation of Ischemic Stroke and Blood Brain Barrier Disruption in Mild But Not Severe Hyperhomocysteinemia.

J Am Heart Assoc 2020 02 13;9(4):e013368. Epub 2020 Feb 13.

Department of Internal Medicine University of Iowa Carver College of Medicine Iowa City IA.

Background Hyperhomocysteinemia is a risk factor for ischemic stroke; however, a targeted treatment strategy is lacking partly because of limited understanding of the causal role of homocysteine in cerebrovascular pathogenesis. Methods and Results In a genetic model of cystathionine beta synthase (CBS) deficiency, we tested the hypothesis that elevation in plasma total homocysteine exacerbates cerebrovascular injury and that memantine, a N-methyl-D-aspartate receptor antagonist, is protective. Mild or severe elevation in plasma total homocysteine was observed in (6.1±0.3 μmol/L) or (309±18 μmol/L) mice versus (3.1±0.6 μmol/L) mice. Surprisingly, and mice exhibited similar increases in cerebral infarct size following middle cerebral artery ischemia/reperfusion injury, despite the much higher total homocysteine levels in mice. Likewise, disruption of the blood brain barrier was observed in both and mice. Administration of the N-methyl-D-aspartate receptor antagonist memantine protected but not mice from cerebral infarction and blood brain barrier disruption. Our data suggest that the differential effect of memantine in versus mice may be related to changes in expression of N-methyl-D-aspartate receptor subunits. , but not mice had increased expression of NR2B subunit, which is known to be relatively insensitive to homocysteine. Conclusions These data provide experimental evidence that even a mild increase in plasma total homocysteine can exacerbate cerebrovascular injury and suggest that N-methyl-D-aspartate receptor antagonism may represent a strategy to prevent reperfusion injury after acute ischemic stroke in patients with mild hyperhomocysteinemia.
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http://dx.doi.org/10.1161/JAHA.119.013368DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7070222PMC
February 2020

One-carbon metabolism supplementation improves outcome after stroke in aged male MTHFR-deficient mice.

Neurobiol Dis 2019 12 13;132:104613. Epub 2019 Sep 13.

Department of Neuroscience, Carleton University, Ottawa, ON, Canada.

The prevalence of stroke increases with age and the ability to absorb all nutrients from our diets decreases with age. Nutrition is a modifiable risk factor for stroke, which is a leading cause of death and disability in world-wide. Deficiencies in one‑carbon metabolism, including in methyltetrahydrofolate reductase (MTHFR), have been linked to increased risk of stroke. The Mthfr mice mouse model mimic the phenotype of the MTHFR677C➔T polymorphism, such as elevated levels of homocystine. Using this mouse model, the aim of this study was to investigate the impact of dietary supplementation with 5-methylTHF, vitamin B12, and choline after ischemic stroke. Male Mthfr and wildtype littermate control mice were aged (~1.5-year-old) and were placed on control diet (CD) 4-weeks prior to sensorimotor cortex damage using photothrombosis (PT), a model for ischemic stroke. Post-operatively, one group of Mthfr and wildtype littermate mice were placed on 5-methylTHF, vitamin B12, and choline supplemented diet (SD). Four weeks after PT and SD motor function was assessed using the accelerating rotarod, forepaw asymmetry, and ladder beam walking tasks. Total homocysteine and cysteine levels were measured in blood. Brain tissue was processed to assess lesion volume and investigate biochemical and molecular changes. After PT and SD, Mthfr mice were able to stay on the accelerating rotarod longer and used their impaired forepaw to explore more when compared to CD animals. Furthermore, total homocysteine levels in plasma and lesion volume were reduced in Mthfr and Mthfr SD mice. Within the damage site, there were reduced levels of apoptotic cell death and increased neuroprotective cellular response in the brains of SD treated Mthfr mice. This study reveals a critical role for one‑carbon supplementation, with 5-methylTHF, vitamin B12, and choline, in supporting improvement after ischemic stroke damage.
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http://dx.doi.org/10.1016/j.nbd.2019.104613DOI Listing
December 2019

Gamma-Hydroxybutyrate content in dried bloodspots facilitates newborn detection of succinic semialdehyde dehydrogenase deficiency.

Mol Genet Metab 2019 Sep - Oct;128(1-2):109-112. Epub 2019 Jul 18.

Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA, United States of America. Electronic address:

Increased gamma-hydroxybutyric acid in urine and blood are metabolic hallmarks of succinic semialdehyde dehydrogenase deficiency, a defect of 4-aminobutyric acid metabolism. Here, we examined the hypothesis that succinic semialdehyde dehydrogenase deficiency could be identified via measurement of gamma-hydroxybutyric acid in newborn and post-newborn dried bloodspots. Quantitation of gamma-hydroxybutyric acid using liquid chromatography-tandem mass spectrometry in twelve archival newborn patient dried bloodspots was 360 ± 57 μM (mean, standard error; range 111-767), all values exceeding the previously established cutoff for newborn detection of 78 μΜ established from 2831 dried bloodspots derived from newborns, neonates and children. Gamma-hydroxybutyric acid in post-newborn dried bloodspots (n = 19; ages 0.8-38 years) was 191 ± 65 μM (mean, standard error; range 20-1218), exceeding the aforementioned GHB cutoff for patients approximately 10 years of age or younger. Further, gamma-hydroxybutyric acid in post-newborn dried bloodspots displayed a significant (p < .0001) inverse correlation with age. This preliminary study suggests that succinic semialdehyde dehydrogenase deficiency may be identified in newborn and post-newborn dried bloodspots via quantitation of gamma-hydroxybutyric acid, while forming the platform for more extensive studies in affected and unaffected dried bloodspots.
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http://dx.doi.org/10.1016/j.ymgme.2019.07.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6961708PMC
April 2020

Betaine attenuates pathology by stimulating lipid oxidation in liver and regulating phospholipid metabolism in brain of methionine-choline-deficient rats.

FASEB J 2019 08 23;33(8):9334-9349. Epub 2019 May 23.

The Institute of Biochemistry Food and Nutrition Science, The Robert H. Smith Faculty of Agriculture Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.

Methyl-donor deficiency is a risk factor for neurodegenerative diseases. Dietary deficiency of the methyl-donors methionine and choline [methionine-choline-deficient (MCD) diet] is a well-established model of nonalcoholic steatohepatitis (NASH), yet brain metabolism has not been studied in this model. We hypothesized that supplemental betaine would protect both the liver and brain in this model and that any benefit to the brain would be due to improved liver metabolism because betaine is a methyl-donor in liver methylation but is not metabolically active in the brain. We fed male Sprague-Dawley rats a control diet, MCD diet, or betaine-supplemented MCD (MCD+B) diet for 8 wk and collected blood and tissue. As expected, betaine prevented MCD diet-induced NASH. However, contrary to our prediction, it did not appear to do so by stimulating methylation; the MCD+B diet worsened hyperhomocysteinemia and depressed liver methylation potential 8-fold compared with the MCD diet. Instead, it significantly increased the expression of genes involved in β-oxidation: fibroblast growth factor 21 and peroxisome proliferator-activated receptor α. In contrast to that of the liver, brain methylation potential was unaffected by diet. Nevertheless, several phospholipid (PL) subclasses involved in stabilizing brain membranes were decreased by the MCD diet, and these improved modestly with betaine. The protective effect of betaine is likely due to the stimulation of β-oxidation in liver and the effects on PL metabolism in brain.-Abu Ahmad, N., Raizman, M., Weizmann, N., Wasek, B., Arning, E., Bottiglieri, T., Tirosh, O., Troen, A. M. Betaine attenuates pathology by stimulating lipid oxidation in liver and regulating phospholipid metabolism in brain of methionine-choline-deficient rats.
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http://dx.doi.org/10.1096/fj.201802683RDOI Listing
August 2019

Alteration of lipid metabolism in chronic kidney disease, the role of novel antihyperlipidemic agents, and future directions.

Rev Cardiovasc Med 2018 Sep;19(3):77-88

Department of Internal Medicine, Baylor University Medical Center Roberts Hospitals, Suite H-102 3500 Gaston Ave, Dallas, TX 75246 USA.

The role of anti-hyperlipidemic therapy remains of key importance in the treatment of atherosclerotic disease. Moreover, given an already exaggerated predisposition for vascular disease at baseline, there is a preponderance of data that show management of hyperlipidemia is especially important in patients with chronic kidney disease. This is a concise, up-to-date review of lipid physiology, alterations in lipid concentrations with progressive renal failure, and currently available and emerging hyperlipidemic treatment options. Specifically, the roles of these therapies in patients with chronic kidney disease are reviewed.
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http://dx.doi.org/10.31083/j.rcm.2018.03.908DOI Listing
September 2018

Maternal glutamine supplementation in murine succinic semialdehyde dehydrogenase deficiency, a disorder of γ-aminobutyric acid metabolism.

J Inherit Metab Dis 2019 09 29;42(5):1030-1039. Epub 2019 May 29.

Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington.

Murine succinic semialdehyde dehydrogenase deficiency (SSADHD) manifests with high concentrations of γ-aminobutyric acid (GABA) and γ-hydroxybutyrate (GHB) and low glutamine in the brain. To understand the pathogenic contribution of central glutamine deficiency, we exposed aldh5a1 (SSADHD) mice and their genetic controls (aldh5a1 ) to either a 4% (w/w) glutamine-containing diet or a glutamine-free diet from conception until postnatal day 30. Endpoints included brain, liver and blood amino acids, brain GHB, ataxia scores, and open field testing. Glutamine supplementation did not improve aldh5a1 brain glutamine deficiency nor brain GABA and GHB. It decreased brain glutamate but did not change the ratio of excitatory (glutamate) to inhibitory (GABA) neurotransmitters. In contrast, glutamine supplementation significantly increased brain arginine (30% for aldh5a1 and 18% for aldh5a1 mice), and leucine (12% and 18%). Glutamine deficiency was confirmed in the liver. The test diet increased hepatic glutamate in both genotypes, decreased glutamine in aldh5a1 but not in aldh5a1 , but had no effect on GABA. Dried bloodspot analyses showed significantly elevated GABA in mutants (approximately 800% above controls) and decreased glutamate (approximately 25%), but no glutamine difference with controls. Glutamine supplementation did not impact blood GABA but significantly increased glutamine and glutamate in both genotypes indicating systemic exposure to dietary glutamine. Ataxia and pronounced hyperactivity were observed in aldh5a1 mice but remained unchanged by the diet intervention. The study suggests that glutamine supplementation improves peripheral but not central glutamine deficiency in experimental SSADHD. Future studies are needed to fully understand the pathogenic role of brain glutamine deficiency in SSADHD.
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http://dx.doi.org/10.1002/jimd.12107DOI Listing
September 2019

Rett syndrome (MECP2) and succinic semialdehyde dehydrogenase (ALDH5A1) deficiency in a developmentally delayed female.

Mol Genet Genomic Med 2019 05 4;7(5):e629. Epub 2019 Mar 4.

Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington.

Background: We present a patient with Rett syndrome (RTT; MECP2) and autosomal-recessive succinic semialdehyde dehydrogenase deficiency (SSADHD; ALDH5A1 (aldehyde dehydrogenase 5a1 = SSADH), in whom the current phenotype exhibits features of SSADHD (hypotonia, global developmental delay) and RTT (hand stereotypies, gait anomalies).

Methods: γ-Hydroxybutyric acid (GHB) was quantified by UPLC-tandem mass spectrometry, while mutation analysis followed standard methodology of whole-exome sequencing.

Results: The biochemical hallmark of SSADHD, GHB was increased in the proband's dried bloodspot (DBS; 673 µM; previous SSADHD DBSs (n = 7), range 124-4851 µM); control range (n = 2,831), 0-78 µM. The proband was compound heterozygous for pathogenic ALDH5A1 mutations (p.(Asn418IlefsTer39); maternal; p.(Gly409Asp); paternal) and a de novo RTT nonsense mutation in MECP2 (p.Arg255*).

Conclusion: The major inhibitory neurotransmitter, γ-aminobutyric acid (GABA), is increased in SSADHD but normal in RTT, although there are likely regional changes in GABA receptor distribution. GABAergic anomalies occur in both disorders, each featuring an autism spectrum phenotype. What effect the SSADHD biochemical anomalies (elevated GABA, GHB) might play in the neurodevelopmental/epileptic phenotype of our patient is currently unknown.
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http://dx.doi.org/10.1002/mgg3.629DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6503008PMC
May 2019

Metabolomic analyses of vigabatrin (VGB)-treated mice: GABA-transaminase inhibition significantly alters amino acid profiles in murine neural and non-neural tissues.

Neurochem Int 2019 05 26;125:151-162. Epub 2019 Feb 26.

Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA, USA. Electronic address:

The anticonvulsant vigabatrin (VGB; Sabril) irreversibly inhibits GABA transaminase to increase neural GABA, yet its mechanism of retinal toxicity remains unclear. VGB is suggested to alter several amino acids, including homocarnosine, β-alanine, ornithine, glycine, taurine, and 2-aminoadipic acid (AADA), the latter a homologue of glutamic acid. Here, we evaluate the effect of VGB on amino acid concentrations in mice, employing a continuous VGB infusion (subcutaneously implanted osmotic minipumps), dose-escalation paradigm (35-140 mg/kg/d, 12 days), and amino acid quantitation in eye, visual and prefrontal cortex, total brain, liver and plasma. We hypothesized that continuous VGB dosing would reveal numerous hitherto undescribed amino acid disturbances. Consistent amino acid elevations across tissues included GABA, β-alanine, carnosine, ornithine and AADA, as well as neuroactive aspartic and glutamic acids, serine and glycine. Maximal increase of AADA in eye occurred at 35 mg/kg/d (41 ± 2 nmol/g (n = 21, vehicle) to 60 ± 8.5 (n = 8)), and at 70 mg/kg/d for brain (97 ± 6 (n = 21) to 145 ± 6 (n = 6)), visual cortex (128 ± 6 to 215 ± 19) and prefrontal cortex (124 ± 11 to 200 ± 13; mean ± SEM; p < 0.05), the first demonstration of tissue AADA accumulation with VGB in mammal. VGB effects on basic amino acids, including guanidino-species, suggested the capacity of VGB to alter urea cycle function and nitrogen disposal. The known toxicity of AADA in retinal glial cells highlights new avenues for assessing VGB retinal toxicity and other off-target effects.
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http://dx.doi.org/10.1016/j.neuint.2019.02.015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6414070PMC
May 2019

Can targeted metabolomics predict depression recovery? Results from the CO-MED trial.

Transl Psychiatry 2019 01 16;9(1):11. Epub 2019 Jan 16.

Department of Psychiatry, University of Texas Southwestern, Dallas, TX, 75390, USA.

Metabolomics is a developing and promising tool for exploring molecular pathways underlying symptoms of depression and predicting depression recovery. The AbsoluteIDQ™ p180 kit was used to investigate whether plasma metabolites (sphingomyelins, lysophosphatidylcholines, phosphatidylcholines, and acylcarnitines) from a subset of participants in the Combining Medications to Enhance Depression Outcomes (CO-MED) trial could act as predictors or biologic correlates of depression recovery. Participants in this trial were assigned to one of three pharmacological treatment arms: escitalopram monotherapy, bupropion-escitalopram combination, or venlafaxine-mirtazapine combination. Plasma was collected at baseline in 159 participants and again 12 weeks later at study exit in 83 of these participants. Metabolite concentrations were measured and combined with clinical and sociodemographic variables using the hierarchical lasso to simultaneously model whether specific metabolites are particularly informative of depressive recovery. Increased baseline concentrations of phosphatidylcholine C38:1 showed poorer outcome based on change in the Quick Inventory of Depressive Symptoms (QIDS). In contrast, an increased ratio of hydroxylated sphingomyelins relative to non-hydroxylated sphingomyelins at baseline and a change from baseline to exit suggested a better reduction of symptoms as measured by QIDS score. All metabolite-based models performed superior to models only using clinical and sociodemographic variables, suggesting that metabolomics may be a valuable tool for predicting antidepressant outcomes.
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http://dx.doi.org/10.1038/s41398-018-0349-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6341111PMC
January 2019

Targeted metabolomics to understand the association between arsenic metabolism and diabetes-related outcomes: Preliminary evidence from the Strong Heart Family Study.

Environ Res 2019 01 27;168:146-157. Epub 2018 Sep 27.

Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, NY, USA; Department of Environmental Health & Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA. Electronic address:

Background: Inorganic arsenic exposure is ubiquitous and both exposure and inter-individual differences in its metabolism have been associated with cardiometabolic risk. A more efficient arsenic metabolism profile (lower MMA%, higher DMA%) has been associated with reduced risk for arsenic-related health outcomes. This profile, however, has also been associated with increased risk for diabetes-related outcomes.

Objectives: The mechanism behind these conflicting associations is unclear; we hypothesized the one-carbon metabolism (OCM) pathway may play a role.

Methods: We evaluated the influence of OCM on the relationship between arsenic metabolism and diabetes-related outcomes (HOMA2-IR, waist circumference, fasting plasma glucose) using metabolomic data from an OCM-specific and P180 metabolite panel measured in plasma, arsenic metabolism measured in urine, and HOMA2-IR and FPG measured in fasting plasma. Samples were drawn from baseline visits (2001-2003) in 59 participants from the Strong Heart Family Study, a family-based cohort study of American Indians aged ≥14 years from Arizona, Oklahoma, and North/South Dakota.

Results: In unadjusted analyses, a 5% increase in DMA% was associated with higher HOMA2-IR (geometric mean ratio (GMR)= 1.13 (95% CI: 1.03, 1.25)) and waist circumference (mean difference=3.66 (0.95, 6.38). MMA% was significantly associated with lower HOMA2-IR and waist circumference. After adjustment for OCM-related metabolites (SAM, SAH, cysteine, glutamate, lysophosphatidylcholine 18.2, and three phosphatidlycholines), associations were attenuated and no longer significant.

Conclusions: These preliminary results indicate that the association of lower MMA% and higher DMA% with diabetes-related outcomes may be influenced by OCM status, either through confounding, reverse causality, or mediation.
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http://dx.doi.org/10.1016/j.envres.2018.09.034DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6298442PMC
January 2019

Neuropathology of vitamin B deficiency in the Cd320 mouse.

FASEB J 2019 02 10;33(2):2563-2573. Epub 2018 Oct 10.

Department of Medicine, and SUNY Downstate Medical Center, Brooklyn, New York, USA.

In humans, vitamin B deficiency causes peripheral and CNS manifestations. Loss of myelin in the peripheral nerves and the spinal cord (SC) contributes to peripheral neuropathy and motor deficits. The metabolic basis for the demyelination and brain disorder is unknown. The transcobalamin receptor-knockout mouse ( Cd320) develops cobalamin (Cbl) deficiency in the nervous system, with mild anemia. A decreased S-adenosylmethionine: S-adenosylhomocysteine ratio and increased methionine were seen in the brain with no significant changes in neurotransmitter metabolites. The structural pathology in the SC presented as loss of myelin in the axonal tracts with inflammation. The sciatic nerve (SN) showed increased nonuniform, internodal segments suggesting demyelination, and remyelination in progress. Consistent with these changes, the Cd320 mouse showed an increased latency to thermal nociception. Further, lower amplitude of compound action potential in the SN suggested that the functional capacity of the heavily myelinated axons were preferentially compromised, leading to loss of peripheral sensation. Although the metabolic basis for the demyelination and the structural and functional alterations of the nervous system in Cbl deficiency remain unresolved, the Cd320 mouse provides a unique model to investigate the pathologic consequences of vitamin B deficiency. -Arora, K., Sequeira, J. M., Alarcon, J. M., Wasek, B., Arning, E., Bottiglieri, T., Quadros, E. V. Neuropathology of vitamin B deficiency in the Cd320 mouse.
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http://dx.doi.org/10.1096/fj.201800754RRDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6338625PMC
February 2019

Drug-Penetration Gradients Associated with Acquired Drug Resistance in Patients with Tuberculosis.

Am J Respir Crit Care Med 2018 11;198(9):1208-1219

1 Center for Lung Infection and Immunity, Division of Pulmonology and University of Cape Town Lung Institute, Department of Medicine.

Rationale: Acquired resistance is an important driver of multidrug-resistant tuberculosis (TB), even with good treatment adherence. However, exactly what initiates the resistance and how it arises remain poorly understood.

Objectives: To identify the relationship between drug concentrations and drug susceptibility readouts (minimum inhibitory concentrations [MICs]) in the TB cavity.

Methods: We recruited patients with medically incurable TB who were undergoing therapeutic lung resection while on treatment with a cocktail of second-line anti-TB drugs. On the day of surgery, antibiotic concentrations were measured in the blood and at seven prespecified biopsy sites within each cavity. Mycobacterium tuberculosis was grown from each biopsy site, MICs of each drug identified, and whole-genome sequencing performed. Spearman correlation coefficients between drug concentration and MIC were calculated.

Measurements And Main Results: Fourteen patients treated for a median of 13 months (range, 5-31 mo) were recruited. MICs and drug resistance-associated single-nucleotide variants differed between the different geospatial locations within each cavity, and with pretreatment and serial sputum isolates, consistent with ongoing acquisition of resistance. However, pretreatment sputum MIC had an accuracy of only 49.48% in predicting cavitary MICs. There were large concentration-distance gradients for each antibiotic. The location-specific concentrations inversely correlated with MICs (P < 0.05) and therefore acquired resistance. Moreover, pharmacokinetic/pharmacodynamic exposures known to amplify drug-resistant subpopulations were encountered in all positions.

Conclusions: These data inform interventional strategies relevant to drug delivery, dosing, and diagnostics to prevent the development of acquired resistance. The role of high intracavitary penetration as a biomarker of antibiotic efficacy, when assessing new regimens, requires clarification.
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http://dx.doi.org/10.1164/rccm.201711-2333OCDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6221573PMC
November 2018

Methylenetetrahydrofolate Reductase Deficiency Deregulates Regional Brain Amyloid-β Protein Precursor Expression and Phosphorylation Levels.

J Alzheimers Dis 2018 ;64(1):223-237

School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia.

Deregulation of the amyloid-β protein precursor (AβPP) plays a critical role in the neurodegenerative cascade of Alzheimer's disease (AD). Significantly, common functional polymorphisms in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene are a risk factor for the development of late-onset AD. Reduced MTHFR activity is associated with alterations in folate and homocysteine metabolism. Here, we first show that in young MTHFR knockout mice, mild and severe MTHFR deficiency markedly increase cortical and hippocampal AβPP phosphorylation at the regulatory Thr668 site. However, the hippocampus is especially vulnerable to the effects of aging and mild MTHFR deficiency. Notably, the effects of severe MTHFR deficiency in young mice are recapitulated by prolonged dietary folate deficiency in old mice, which leads to regional brain accumulation of cystathionine due to impaired methylation of homocysteine. The incremental AβPP phosphorylation at Thr668 mediated by severe genetic-or diet-induced impairment of the folate cycle correlates with enhanced accumulation of demethylated protein phosphatase 2A (PP2A), and activation of glycogen synthase kinase-3β (GSK-3β). Lastly, we show that severe disturbances in folate metabolism can also affect AβPP expression levels in a brain region specific manner. Together our findings identify a novel link between genetic MTHFR deficiency, activation of GSK-3β, demethylation of PP2A, and enhanced phosphorylation of AβPP at Thr668, which is known to critically influence neuronal AβPP function and pathological amyloidogenic processing. Deregulation of AβPP provides a novel mechanism by which common human MTHFR polymorphisms may interact with dietary folate deficiency to alter neuronal homeostasis and increase the risk for sporadic AD.
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http://dx.doi.org/10.3233/JAD-180032DOI Listing
June 2019

The use of microwave irradiation for quantitative analysis of neurotransmitters in the mouse brain.

J Neurosci Methods 2018 09 23;307:188-193. Epub 2018 May 23.

Institute of Metabolic Disease, Baylor Scott and White Research Institute, Dallas, TX, United States.

Background: Assessing neurotransmitter metabolism in the brain is essential in studying the effects of drugs, dietary modification and characterizing transgenic mouse models of human neurodegenerative diseases. Regional brain concentrations of parent neurotransmitters and related metabolites are informative and provide a snap shot of the steady-state levels. The choice in method of sacrificing mice may differ from one laboratory to another, and the technique in removal of brain may have limitations depending on speed in which tissue can be dissected and frozen to prevent post-mortem changes.

New Methods: In order to better assess neurotransmitter metabolism in an effective and standardized manner we evaluated microwave irradiation as a method of sacrificing mice. Mice were sacrificed by CO asphyxiation followed by cervical dislocation or microwave irradiation at 4 Kw for 1.1 s. Brain tissue was harvested into five regions and stored at -80 °C until analysis by either LC-MS/MS for acetylcholine, choline and GABA, or HPLC-EC for dopamine, serotonin and norepinephrine and related metabolites.

Results: The results of our study showed considerable differences in the levels of neurotransmitters between the two methods of sacrifice. Overall, the concentrations of neurotransmitters were higher in mice sacrificed by microwave irradiation, except for GABA, which was lower.

Comparison With Existing Method(s): Previous microwave irradiation studies employed presently outdated equipment and neurotransmitter analysis methods, and were not as comprehensive.

Conclusions: The combination of microwave irradiation with LC-MS/MS and HPLC-EC detection allows accurate and sensitive measurement of several neurotransmitter systems in discrete mouse brain regions.
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http://dx.doi.org/10.1016/j.jneumeth.2018.05.016DOI Listing
September 2018

Low Dietary Folate Interacts with MTHFD1 Synthetase Deficiency in Mice, a Model for the R653Q Variant, to Increase Incidence of Developmental Delays and Defects.

J Nutr 2018 04;148(4):501-509

Departments of Human Genetics and Pediatrics, McGill University, and the Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.

Background: Suboptimal folate intake, a risk factor for birth defects, is common even in areas with folate fortification. A polymorphism in methylenetetrahydrofolate dehydrogenase 1 (MTHFD1), R653Q (MTHFD1 c.1958 G > A), has also been associated with increased birth defect risk, likely through reduced purine synthesis.

Objective: We aimed to determine if the interaction of MTHFD1 synthetase deficiency and low folate intake increases developmental abnormalities in a mouse model for MTHFD1 R653Q.

Methods: Female Mthfd1S+/+ and Mthfd1S+/- mice were fed control or low-folate diets (2 and 0.3 mg folic acid/kg diet, respectively) before mating and during pregnancy. Embryos and placentas were examined for anomalies at embryonic day 10.5. Maternal 1-carbon metabolites were measured in plasma and liver.

Results: Delays and defects doubled in litters of Mthfd1S+/- females fed low-folate diets compared to wild-type females fed either diet, or Mthfd1S+/- females fed control diets [P values (defects): diet 0.003, maternal genotype 0.012, diet × maternal genotype 0.014]. These adverse outcomes were associated with placental dysmorphology. Intrauterine growth restriction was increased by embryonic Mthfd1S+/- genotype, folate deficiency, and interaction of maternal Mthfd1S+/- genotype with folate deficiency (P values: embryonic genotype 0.045, diet 0.0081, diet × maternal genotype 0.0019). Despite a 50% increase in methylenetetrahydrofolate reductase expression in low-folate maternal liver (P diet = 0.0007), methyltetrahydrofolate concentration decreased 70% (P diet <0.0001) and homocysteine concentration doubled in plasma (P diet = 0.0001); S-adenosylmethionine decreased 40% and S-adenosylhomocysteine increased 20% in low-folate maternal liver (P diet = 0.002 and 0.0002, respectively).

Conclusions: MTHFD1 synthetase-deficient mice are more sensitive to low folate intake than wild-type mice during pregnancy. Reduced purine synthesis due to synthetase deficiency and altered methylation potential due to low folate may increase pregnancy complications. Further studies and individualized intake recommendations may be required for women homozygous for the MTHFD1 R653Q variant.
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http://dx.doi.org/10.1093/jn/nxy013DOI Listing
April 2018