scholarly journals Postpartum corticosterone and fluoxetine shift the tryptophan-kynurenine pathway in dams

2021 ◽  
Author(s):  
Wansu Qiu ◽  
Kimberly A. Go ◽  
Yvonne Lamers ◽  
Liisa A. M. Galea
Keyword(s):  
Selective Serotonin Reuptake Inhibitors ◽  
De Novo ◽  
Kynurenine Pathway ◽  
Xanthurenic Acid ◽  
Plasma Tryptophan ◽  
Limited Efficacy ◽  
Metabolite Concentrations ◽  
Antidepressant Efficacy ◽  
Enzyme Cofactors ◽  
Hydroxyanthranilic Acid

AbstractPerinatal depression (PND) affects 15% of mothers. Selective serotonin reuptake inhibitors (SSRIs) are currently the first-line of treatment for PND, but are not always efficacious. Previously, we found significant reductions in plasma tryptophan concentrations and higher hippocampal proinflammatory cytokine, IL-1β levels, due to maternal SSRI treatment. Both inflammation and tryptophan-kynurenine metabolic pathway (TKP) are associated with SSRI efficacy in individuals with major depressive disorder (MDD). TKP is divided into neuroprotective and neurotoxic pathways. Higher metabolite concentrations of the neurotoxic pathway are associated with depression onset and implicated in SSRI efficacy. Metabolites in TKP were investigated in a rodent model of de novo postpartum depression (PPD) given treatment with the SSRI, fluoxetine (FLX). Dams were administered corticosterone (CORT) (40mg/kg, s.c.), and treated with the SSRI, fluoxetine (FLX) (10mg/kg, s.c.), during the postpartum for 22 days after parturition. Plasma TKP metabolite concentrations were quantified on the last day of treatment. Maternal postpartum CORT increased neurotoxic metabolites and co-enzyme/cofactors in dams (3-hydroxykynurenine, 3-hydroxyanthranilic acid, vitamin B2, flavin adenine dinucleotide). The combination of both CORT and FLX shifted the neuroprotective-to-neurotoxic ratio towards neurotoxicity. Postpartum FLX decreased plasma xanthurenic acid concentrations. Together, our data indicate higher neurotoxic TKP expression due to maternal postpartum CORT treatment, similar to clinical presentation of MDD. Moreover, maternal FLX treatment showed limited efficacy to influence TKP metabolites, which may correspond to its limited efficacy to treat depressive-like endophenotypes. Overall suggesting changes in TKP may be used as a biomarker of de novo PPD and antidepressant efficacy and targeting this pathway may serve as a potential therapeutic target.

scholarly journals Combined Fluoxetine and Metformin Treatment Potentiates Antidepressant Efficacy Increasing IGF2 Expression in the Dorsal Hippocampus

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Silvia Poggini ◽  
Maria Teresa Golia ◽  
Silvia Alboni ◽  
Giampaolo Milior ◽  
Livio Pepè Sciarria ◽  
...  
Keyword(s):  
Mouse Model ◽  
Selective Serotonin Reuptake Inhibitors ◽  
Dorsal Hippocampus ◽  
Combined Treatment ◽  
Antidepressant Drugs ◽  
Long Term Potentiation ◽  
Living Environment ◽  
Metformin Treatment ◽  
Limited Efficacy ◽  
Antidepressant Efficacy

An increasing number of studies show that selective serotonin reuptake inhibitors (SSRIs) exert their therapeutic action, at least in part, by amplifying the influence of the living environment on mood. As a consequence, when administered in a favorable environment, SSRIs lead to a reduction of symptoms, but in stressful conditions, they show limited efficacy. Therefore, novel therapeutic approaches able to neutralize the influence of the stressful environment on treatment are needed. The aim of our study was to test whether, in a mouse model of depression, the combined administration of SSRI fluoxetine and metformin, a drug able to improve the metabolic profile, counteracts the limited efficacy of fluoxetine alone when administered in stressful conditions. Indeed, metabolic alterations are associated to both the onset of major depression and the antidepressant efficacy. To this goal, adult C57BL/6 male mice were exposed to stress for 6 weeks; the first two weeks was aimed at generating a mouse model of depression. During the remaining 4 weeks, mice received one of the following treatments: vehicle, fluoxetine, metformin, or a combination of fluoxetine and metformin. We measured liking- and wanting-type anhedonia as behavioral phenotypes of depression and assessed the expression levels of selected genes involved in major depressive disorder and antidepressant response in the dorsal and ventral hippocampus, which are differently involved in the depressive symptomatology. The combined treatment was more effective than fluoxetine alone in ameliorating the depressive phenotype after one week of treatment. This was associated to an increase in IGF2 mRNA expression and enhanced long-term potentiation, specifically in the dorsal hippocampus, at the end of treatment. Overall, the present results show that, when administered in stressful conditions, the combined fluoxetine and metformin treatment may represent a more effective approach than fluoxetine alone in a short term. Finally, our findings highlight the relevance of polypharmacological strategy as effective interventions to increase the efficacy of the antidepressant drugs currently available.

scholarly journals Assessment of the Human Kynurenine Pathway: Comparisons and Clinical Implications of Ethnic and Gender Differences in Plasma Tryptophan, Kynurenine Metabolites, and Enzyme Expressions at Baseline and after Acute Tryptophan Loading and Depletion

2016 ◽  
Vol 9 ◽  
pp. IJTR.S38189 ◽  
Author(s):  
Abdulla A.-B. Badawy ◽  
Donald M. Dougherty
Keyword(s):  
Gender Differences ◽  
African American ◽  
African American Women ◽  
Kynurenine Pathway ◽  
Plasma Tryptophan ◽  
Acid Ratio ◽  
Health And Disease ◽  
Hydroxyanthranilic Acid ◽  
And Gender ◽  
Rate Limiting

Tryptophan (Trp) metabolism via the kynurenine pathway (KP) was assessed in normal healthy US volunteers at baseline and after acute Trp depletion (ATD) and acute Trp loading (ATL) using amino acid formulations. The hepatic KP accounts for ~90% of overall Trp degradation. Liver Trp 2,3-dioxygenase (TDO) contributes ~70% toward Trp oxidation, with the remainder achieved by subsequent rate-limiting enzymes in the KP. TDO is not influenced by a 1.15 g Trp load, but is maximally activated by a 5.15 g dose. We recommend a 30 mg/kg dose for future ATL studies. ATD activates TDO and enhances the Trp flux down the KP via its leucine component. Higher plasma free [Trp] and lower total [Trp] are observed in women, with no gender differences in kynurenines. Kynurenic acid is lower in female Caucasians, which may explain their lower incidence of schizophrenia. African-American and Hispanic women have a lower TDO and Trp oxidation relative to free Trp than the corresponding men. African-American women have a potentially higher 3-hydroxyanthranilic acid/anthranilic acid ratio, which may protect them against osteoporosis. Future studies of the KP in relation to health and disease should focus on gender and ethnic differences.

scholarly journals Vitamins B2and B6as determinants of kynurenines and related markers of interferon-γ-mediated immune activation in the community-based Hordaland Health Study

2014 ◽  
Vol 112 (7) ◽  
pp. 1065-1072 ◽  
Author(s):  
Despoina Theofylaktopoulou ◽  
Arve Ulvik ◽  
Øivind Midttun ◽  
Per Magne Ueland ◽  
Stein Emil Vollset ◽  
...  
Keyword(s):  
Immune Activation ◽  
Plasma Concentrations ◽  
Correlation Coefficients ◽  
Interferon Γ ◽  
Kynurenine Pathway ◽  
Additive Models ◽  
B Vitamins ◽  
Health Study ◽  
Xanthurenic Acid ◽  
Hydroxyanthranilic Acid

Vitamins B2and B6are cofactors in the kynurenine pathway. Many of the kynurenines are neuroactive compounds with immunomodulatory effects. In the present study, we aimed to investigate plasma concentrations of vitamins B2and B6as determinants of kynurenines and two markers of interferon-γ-mediated immune activation (kynurenine:tryptophan ratio (KTR) and neopterin). We measured the concentrations of vitamins B2and B6vitamers, neopterin, tryptophan and six kynurenines (i.e. kynurenine, anthranilic acid, kynurenic acid, 3-hydroxykynurenine, 3-hydroxyanthranilic acid and xanthurenic acid) in plasma from 7051 individuals. Dietary intake of vitamins B2and B6was assessed using a validated FFQ. Associations were investigated using partial Spearman's correlations, generalised additive models, and segmented or multiple linear regression. The B2vitamer, riboflavin, was positively associated with 3-hydroxyanthranilic acid and xanthurenic acid, with correlation coefficients, as obtained by segmented regression, of 0·20 (95 % CI 0·16, 0·23) and 0·24 (95 % CI 0·19, 0·28), at riboflavin concentrations below the median value (13·0 nmol/l). The vitamin B6vitamer, pyridoxal 5′-phosphate (PLP), was positively associated with most kynurenines at PLP concentrations < 39·3–47·0 nmol/l, and inversely associated with 3-hydroxykynurenine with the association being more prominent at PLP concentrations < 18·9 nmol/l. Riboflavin and PLP were associated with xanthurenic acid only at relatively low, but normal concentrations of both vitamers. Lastly, PLP was negatively correlated with neopterin and KTR. These results demonstrate the significant and complex determination of kynurenine metabolism by vitamin status. Future studies on B-vitamins and kynurenines in relation to chronic diseases should therefore integrate data on relevant biomarkers related to B-vitamins status and tryptophan metabolism.

scholarly journals Postpartum fluoxetine increases maternal hippocampal IL-1β and decreased plasma tryptophan: clues for efficacy

2020 ◽  
Author(s):  
Wansu Qiu ◽  
Paula Duarte-Guterman ◽  
Rand S. Eid ◽  
Kimberly A. Go ◽  
Yvonne Lamers ◽  
...  
Keyword(s):  
Postpartum Depression ◽  
Postpartum Period ◽  
Selective Serotonin Reuptake Inhibitors ◽  
Perinatal Depression ◽  
De Novo ◽  
List Type ◽  
Preclinical Research ◽  
Plasma Tryptophan ◽  
Tnf Α ◽  
Ifn Γ

ABSTRACTPerinatal depression (PND) affects approximately 15% of women, and de novo postpartum depression affects approximately 40% of PND cases. Selective serotonin reuptake inhibitors (SSRIs) are a common class of antidepressants prescribed to treat PND. However, the safety and efficacy of SSRIs have been questioned in both clinical and preclinical research. Here, using a preclinical rodent model of postpartum depression, we aim to better understand neuroinflammatory cytokines and tryptophan mechanisms that may be related to SSRIs efficacy. Rodent dams were treated with high corticosterone (CORT; 40mg/kg, s.c.) for 21 days in the postpartum period to simulate depressive-like behaviors in the late postpartum period. Concurrently, a subset of dams was treated with the SSRI, fluoxetine (FLX; 10mg/kg, s.c.), in the postpartum period. We showed, consistent with previous studies, that although maternal FLX treatment prevented CORT-induced disturbances in maternal care behavior during the early postpartum, it failed to prevent the expression of CORT-induced depressive-like behavior in the late postpartum. Furthermore, FLX treatment, regardless of CORT treatment, increased maternal hippocampal IL-1β and decreased maternal plasma tryptophan levels, plasma tryptophan, 4’-pyridoxic acid, and pyridoxal concentrations. Maternal CORT treatment reduced maternal hippocampal TNF-α and IFN-γ levels. Our work suggests that the limited efficacy of FLX in the late postpartum may be associated with elevated levels of the proinflammatory cytokine IL-1β in the maternal hippocampus, decreased plasma tryptophan concentration, and changes in vitamin B6 dependent tryptophan-kynurenine pathway. These findings suggest novel pathways for improving SSRI efficacy in alleviating perinatal depression.HIGHLIGHTSPostpartum fluoxetine (FLX) increased interleukin-1β levels in hippocampusPostpartum corticosterone (CORT) decreased TNF-α and IFN-γ in the hippocampusPostpartum FLX did not prevent CORT-induced depressive-like behaviorPostpartum FLX prevented CORT-induced changes in maternal behaviorPostpartum FLX decreased plasma tryptophan, 4’-pyridoxic acid, and pyridoxal levels

scholarly journals Tryptophan Metabolism in Rat Liver after Administration of Tryptophan, Kynurenine Metabolites, and Kynureninase Inhibitors

2016 ◽  
Vol 9 ◽  
pp. IJTR.S38190 ◽  
Author(s):  
Abdulla A.-B. Badawy ◽  
Samina Bano
Keyword(s):  
Rat Liver ◽  
Immune Activation ◽  
Kynurenic Acid ◽  
Chronic Administration ◽  
Kynurenine Pathway ◽  
Tryptophan Metabolism ◽  
Disease States ◽  
Metabolite Concentrations ◽  
Hydroxyanthranilic Acid ◽  
Stimulation Of

Rat liver tryptophan (Trp), kynurenine pathway metabolites, and enzymes deduced from product/substrate ratios were assessed following acute and/or chronic administration of kynurenic acid (KA), 3-hydroxykynurenine (3-HK), 3-hydroxyanthranilic acid (3-HAA), Trp, and the kynureninase inhibitors benserazide (BSZ) and carbidopa (CBD). KA activated Trp 2,3-dioxygenase (TDO), possibly by increasing liver 3-HAA, but inhibited kynurenine aminotransferase (KAT) and kynureninase activities with 3-HK as substrate. 3-HK inhibited kynureninase activity from 3-HK. 3-HAA stimulated TDO, but inhibited kynureninase activity from K and 3-HK. Trp (50 mg/kg) increased kynurenine metabolite concentrations and KAT from K, and exerted a temporary stimulation of TDO. The kynureninase inhibitors BSZ and CBD also inhibited KAT, but stimulated TDO. BSZ abolished or strongly inhibited the Trp-induced increases in liver Trp and kynurenine metabolites. The potential effects of these changes in conditions of immune activation, schizophrenia, and other disease states are discussed.

scholarly journals Targeting kynurenine metabolism to reduce inflammation and enhance stress response during aging

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 686-687
Author(s):  
George Sutphin ◽  
Hope Dang ◽  
Luis Espejo ◽  
Raul Castro-Portuguez ◽  
Bradford Hull ◽  
...  
Keyword(s):  
Stress Response ◽  
De Novo ◽  
Preliminary Evidence ◽  
Kynurenine Pathway ◽  
Cellular Stress Response ◽  
C Elegans ◽  
Extended Lifespan ◽  
Kynurenine Metabolism ◽  
Hydroxyanthranilic Acid ◽  
The Impact

Abstract Aberrant kynurenine pathway metabolism is increasingly linked to aging and age-associated disease. Kynurenine metabolic activity increases with age and becomes dysregulated during various forms of age-associated pathology in humans. By manipulating one or more kynurenine pathway enzymes and metabolites, we have extended lifespan up to 40% in Caenorhabditis elegans. In particular, elevating physiological levels of the kynurenine pathway metabolite 3-hydroxyanthranilic acid (3HAA) by directly supplementing 3HAA or inhibiting the enzyme 3HAA dioxygenase (HAAO) extends C. elegans lifespan by ~30%. 3HAA delivered chronically in chow similarly extends lifespan in aged C57BL/6 mice. In ongoing work, we are investigating the mechanisms underlying the benefits of multiple kynurenine pathway interventions using tools in C. elegans, mice, and human cell culture. We have preliminary evidence for activation of broad-spectrum cellular stress response, enhanced immune function, and reduced inflammation. Among other roles, the kynurenine pathway is the sole metabolic route for de novo synthesis of nicotinamide adenine dinucleotide (NAD+) from tryptophan in Eukaryotic cells. We are examining the regulatory interaction between kynurenine metabolism and the two NAD+ recycling pathways, Salvage and Preiss-Handler, both as potential mechanistic mediators and as possible parallel targets for combined interventions with synergistic benefits in aging. We are further evaluating the impact of these interventions in several models of specific age-associated diseases, including sepsis, chronic inflammation, stroke, Alzheimer’s disease, and cancer. Finally, we are developing pharmaceutical strategies to replicate key genetic and metabolic interventions within the kynurenine pathway that can be readily translated into clinical applications.

Effect of Nicotinamide Administration on the Tryptophan-Nicotinamide Pathway in Humans

2007 ◽  
Vol 77 (4) ◽  
pp. 255-262 ◽  
Author(s):  
Fukuwatari ◽  
Shibata
Keyword(s):  
Urinary Excretion ◽  
Young Women ◽  
Quinolinic Acid ◽  
Kynurenic Acid ◽  
De Novo ◽  
Conversion Ratio ◽  
Xanthurenic Acid ◽  
Dependent Manner ◽  
Hydroxyanthranilic Acid ◽  
Dose Dependent

The vitamin nicotinamide is synthesized in the liver from tryptophan, and distributed to non-hepatic tissues. Although it is generally accepted that 60 mg tryptophan is equivalent to 1 mg nicotinamide in humans, the conversion ratio of tryptophan to nicotinamide is changeable. To determine if de novo nicotinamide synthesis from tryptophan is influenced by nicotinamide intake itself, six young women consumed controlled diets containing 30.4 or 24.8 mg niacin-equivalent nicotinamide supplements with 0, 89, 310, or 562 μmol/day (0, 10.9, 37.8, or 68.6 mg/day, respectively), and urinary excretion of intermediates and metabolites of the tryptophan-nicotinamide pathway were measured. Urinary excretion of nicotinamide metabolites increased linearly in a dose-dependent manner. None of the intermediates, including anthranilic acid, kynurenic acid, xanthurenic acid, 3-hydroxyanthranilic acid, and quinolinic acid, changed at all, even when up to 562 μmol/day nicotinamide was given. That is, exogenous nicotinamide did not affect de novo nicotinamide synthesis. Therefore, when niacin equivalent is calculated, the intake of nicotinamide itself need not be considered as a factor that changes the tryptophan-nicotinamide conversion ratio.

scholarly journals An enzymatic activation of formaldehyde for nucleotide methylation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Charles Bou-Nader ◽  
Frederick W. Stull ◽  
Ludovic Pecqueur ◽  
Philippe Simon ◽  
Vincent Guérineau ◽  
...  
Keyword(s):  
Amino Acids ◽  
Thymidylate Synthase ◽  
Active Site ◽  
De Novo ◽  
Crystallographic Structure ◽  
De Novo Synthesis ◽  
Active Site Residues ◽  
Enzymatic Activation ◽  
Enzyme Cofactors ◽  
Unique Ability

AbstractFolate enzyme cofactors and their derivatives have the unique ability to provide a single carbon unit at different oxidation levels for the de novo synthesis of amino-acids, purines, or thymidylate, an essential DNA nucleotide. How these cofactors mediate methylene transfer is not fully settled yet, particularly with regard to how the methylene is transferred to the methylene acceptor. Here, we uncovered that the bacterial thymidylate synthase ThyX, which relies on both folate and flavin for activity, can also use a formaldehyde-shunt to directly synthesize thymidylate. Combining biochemical, spectroscopic and anaerobic crystallographic analyses, we showed that formaldehyde reacts with the reduced flavin coenzyme to form a carbinolamine intermediate used by ThyX for dUMP methylation. The crystallographic structure of this intermediate reveals how ThyX activates formaldehyde and uses it, with the assistance of active site residues, to methylate dUMP. Our results reveal that carbinolamine species promote methylene transfer and suggest that the use of a CH2O-shunt may be relevant in several other important folate-dependent reactions.

scholarly journals Intravenous administration of LPS activates the kynurenine pathway in healthy male human subjects: a prospective placebo-controlled cross-over trial

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Vincent Millischer ◽  
Matthias Heinzl ◽  
Anthi Faka ◽  
Michael Resl ◽  
Ada Trepci ◽  
...  
Keyword(s):  
Human Subjects ◽  
Picolinic Acid ◽  
Plasma Concentrations ◽  
Experimental Studies ◽  
Placebo Treatment ◽  
Kynurenine Pathway ◽  
Healthy Male ◽  
Systemic Injection ◽  
Plasma Tryptophan ◽  
Endotoxemia Model

Abstract Background Administration of lipopolysaccharide (LPS) from Gram-negative bacteria, also known as the human endotoxemia model, is a standardized and safe model of human inflammation. Experimental studies have revealed that peripheral administration of LPS leads to induction of the kynurenine pathway followed by depressive-like behavior and cognitive dysfunction in animals. The aim of the present study is to investigate how acute intravenous LPS administration affects the kynurenine pathway in healthy male human subjects. Methods The present study is a prospective, single-blinded, randomized, placebo-controlled cross-over study to investigate the effects of intravenously administered LPS (Escherichia coli O113, 2 ng/kg) on tryptophan and kynurenine metabolites over 48 h and their association with interleukin-6 (IL-6) and C-reactive protein (CRP). The study included 10 healthy, non-smoking men (18–40 years) free from medication. Statistical differences in tryptophan and kynurenine metabolites as well as associations with IL-6 and CRP in LPS and placebo treated subjects were assessed with linear mixed-effects models. Results Systemic injection of LPS was associated with significantly lower concentrations of plasma tryptophan and kynurenine after 4 h, as well as higher concentrations of quinolinic acid (QUIN) after 48 h compared to the placebo injection. No differences were found in kynurenic acid (KYNA) or picolinic acid plasma concentrations between LPS or placebo treatment. The KYNA/kynurenine ratio peaked at 6 h post LPS injection while QUIN/kynurenine maintained significantly higher from 3 h post LPS injection until 24 h. The kynurenine/tryptophan ratio was higher at 24 h and 48 h post LPS treatment. Finally, we report an association between the kynurenine/tryptophan ratio and CRP. Conclusions Our findings strongly support the concept that an inflammatory challenge with LPS induces the kynurenine pathway in humans, activating both the neurotoxic (QUIN) and neuroprotective (KYNA) branch of the kynurenine pathway. Trial registration This study is based on a study registered at ClinicalTrials.gov, NCT03392701. Registered 21 December 2017.

scholarly journals Inhibition of Kynurenine Metabolism and Its Effect in Mitochondrial Function in Hepatocellular Carcinoma

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 124-125
Author(s):  
Raul Castro-Portuguez ◽  
Samuel Freitas ◽  
George Sutphin
Keyword(s):  
Hepatocellular Carcinoma ◽  
Mitochondrial Function ◽  
De Novo ◽  
Principal Component ◽  
Kynurenine Pathway ◽  
The Cancer Genome Atlas ◽  
Wilcoxon Test ◽  
Nad Synthesis ◽  
Significant Difference ◽  
Kynurenine Metabolism

Abstract Hepatocellular carcinoma (HCC) is the most prevalent cancer in the liver. The majority of ingested tryptophan is processed in the liver through the kynurenine pathway, the endpoint of which is de novo NAD+ biosynthesis. Dysregulation of tryptophan-kynurenine metabolism and NAD+ synthesis may promote mitochondrial malfunction, tumor reprogramming, and carcinogenesis. Using a publicly available gene expression dataset from liver hepatocellular carcinoma (LIHC) samples available through The Cancer Genome Atlas (TCGA; n = 371), we employed Principal Component Analysis (PCA), hierarchical clustering, gene-pattern expression profiling, and survival analysis to cluster patients and determine overall survival. Our analysis of genes encoding kynurenine pathway enzymes determined that patients with high QPRT expression had a poor prognosis with decreased median survival, with no effect on the maximum survival. There is a significant difference in the survival between patients with high QPRT expression relative to patients with high HAAO/AFMID expression (HR = 1.2, [95% CI 0.5-1.8] P = 0.0181, Gehan-Breslow-Wilcoxon Test). Patients with high QPRT expression have higher survival rates compared with low QPRT expression (HR = 1.4, [95% CI 0.9-2.2] P = 0.0344, Gehan-Breslow-Wilcoxon Test). To test the consequences of kynurenine-pathway inhibition in mitochondrial function and morphology we use 4-Cl-3HAA, an irreversible HAAO inhibitor, and observed a small increase in mitochondrial fragmentation in HepG2 cells after 24 hours of treatment. We conclude that kynurenine metabolism may be useful as a biomarker to predict patient prognosis among HCC patients. In ongoing work, we are testing QPRT inhibitors in cell culture as a potential adjuvant for chemotherapies.

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