Publications by authors named "Emeline Chu-Van"

8 Publications

  • Page 1 of 1

Mitochondrial metabolism supports resistance to IDH mutant inhibitors in acute myeloid leukemia.

J Exp Med 2021 May;218(5)

Centre de Recherches en Cancérologie de Toulouse, Université de Toulouse, Institut National de la Santé et de la Recherché Médicale, Centre National de la Recherche Scientifique, Toulouse, France.

Mutations in IDH induce epigenetic and transcriptional reprogramming, differentiation bias, and susceptibility to mitochondrial inhibitors in cancer cells. Here, we first show that cell lines, PDXs, and patients with acute myeloid leukemia (AML) harboring an IDH mutation displayed an enhanced mitochondrial oxidative metabolism. Along with an increase in TCA cycle intermediates, this AML-specific metabolic behavior mechanistically occurred through the increase in electron transport chain complex I activity, mitochondrial respiration, and methylation-driven CEBPα-induced fatty acid β-oxidation of IDH1 mutant cells. While IDH1 mutant inhibitor reduced 2-HG oncometabolite and CEBPα methylation, it failed to reverse FAO and OxPHOS. These mitochondrial activities were maintained through the inhibition of Akt and enhanced activation of peroxisome proliferator-activated receptor-γ coactivator-1 PGC1α upon IDH1 mutant inhibitor. Accordingly, OxPHOS inhibitors improved anti-AML efficacy of IDH mutant inhibitors in vivo. This work provides a scientific rationale for combinatory mitochondrial-targeted therapies to treat IDH mutant AML patients, especially those unresponsive to or relapsing from IDH mutant inhibitors.
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http://dx.doi.org/10.1084/jem.20200924DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7995203PMC
May 2021

The effect of acute moderate-intensity exercise on the serum and fecal metabolomes and the gut microbiota of cross-country endurance athletes.

Sci Rep 2021 Feb 11;11(1):3558. Epub 2021 Feb 11.

MAS Microbiota Research Group, Faculty of Biomedical Sciences, Universidad Europea de Madrid, 28670, Villaviciosa de Odón, Madrid, Spain.

Physical exercise can produce changes in the microbiota, conferring health benefits through mechanisms that are not fully understood. We sought to determine the changes driven by exercise on the gut microbiota and on the serum and fecal metabolome using 16S rRNA gene analysis and untargeted metabolomics. A total of 85 serum and 12 fecal metabolites and six bacterial taxa (Romboutsia, Escherichia coli TOP498, Ruminococcaceae UCG-005, Blautia, Ruminiclostridium 9 and Clostridium phoceensis) were modified following a controlled acute exercise session. Among the bacterial taxa, Ruminiclostridium 9 was the most influenced by fecal and serum metabolites, as revealed by linear multivariate regression analysis. Exercise significantly increased the fecal ammonia content. Functional analysis revealed that alanine, aspartate and glutamate metabolism and the arginine and aminoacyl-tRNA biosynthesis pathways were the most relevant modified pathways in serum, whereas the phenylalanine, tyrosine and tryptophan biosynthesis pathway was the most relevant pathway modified in feces. Correlation analysis between fecal and serum metabolites suggested an exchange of metabolites between both compartments. Thus, the performance of a single exercise bout in cross-country non-professional athletes produces significant changes in the microbiota and in the serum and fecal metabolome, which may have health implications.
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http://dx.doi.org/10.1038/s41598-021-82947-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7878499PMC
February 2021

Effect of gut microbiota on depressive-like behaviors in mice is mediated by the endocannabinoid system.

Nat Commun 2020 12 11;11(1):6363. Epub 2020 Dec 11.

Perception and Memory Unit, CNRS UMR3571, Institut Pasteur, Paris, France.

Depression is the leading cause of disability worldwide. Recent observations have revealed an association between mood disorders and alterations of the intestinal microbiota. Here, using unpredictable chronic mild stress (UCMS) as a mouse model of depression, we show that UCMS mice display phenotypic alterations, which could be transferred from UCMS donors to naïve recipient mice by fecal microbiota transplantation. The cellular and behavioral alterations observed in recipient mice were accompanied by a decrease in the endocannabinoid (eCB) signaling due to lower peripheral levels of fatty acid precursors of eCB ligands. The adverse effects of UCMS-transferred microbiota were alleviated by selectively enhancing the central eCB or by complementation with a strain of the Lactobacilli genus. Our findings provide a mechanistic scenario for how chronic stress, diet and gut microbiota generate a pathological feed-forward loop that contributes to despair behavior via the central eCB system.
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http://dx.doi.org/10.1038/s41467-020-19931-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7732982PMC
December 2020

L-Serine dietary supplementation is associated with clinical improvement of loss-of-function -related pediatric encephalopathy.

Sci Signal 2019 06 18;12(586). Epub 2019 Jun 18.

Bellvitge Biomedical Research Institute (IDIBELL)-Unit of Neuropharmacology and Pain, University of Barcelona, Barcelona 08908, Spain.

Autosomal dominant mutations in are associated with severe encephalopathy, but little is known about the pathophysiological outcomes and any potential therapeutic interventions. Genetic studies have described the association between de novo mutations of genes encoding the subunits of the -methyl-d-aspartate receptor (NMDAR) and severe neurological conditions. Here, we evaluated a missense mutation in , causing a proline-to-threonine switch (P553T) in the GluN2B subunit of NMDAR, which was found in a 5-year-old patient with Rett-like syndrome with severe encephalopathy. Structural molecular modeling predicted a reduced pore size of the mutant GluN2B-containing NMDARs. Electrophysiological recordings in a HEK-293T cell line expressing the mutated subunit confirmed this prediction and showed an associated reduced glutamate affinity. Moreover, GluN2B(P553T)-expressing primary murine hippocampal neurons showed decreased spine density, concomitant with reduced NMDA-evoked currents and impaired NMDAR-dependent insertion of the AMPA receptor subunit GluA1 at stimulated synapses. Furthermore, the naturally occurring coagonist d-serine restored function to GluN2B(P553T)-containing NMDARs. l-Serine dietary supplementation of the patient was hence initiated, resulting in the increased abundance of d-serine in the plasma and brain. The patient has shown notable improvements in motor and cognitive performance and communication after 11 and 17 months of l-serine dietary supplementation. Our data suggest that l-serine supplementation might ameliorate -related severe encephalopathy and other neurological conditions caused by glutamatergic signaling deficiency.
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http://dx.doi.org/10.1126/scisignal.aaw0936DOI Listing
June 2019

Orchestration of Tryptophan-Kynurenine Pathway, Acute Decompensation, and Acute-on-Chronic Liver Failure in Cirrhosis.

Hepatology 2019 04 19;69(4):1686-1701. Epub 2019 Mar 19.

European Foundation for the Study of Chronic Liver Failure Consortium and Grifols Chair, Barcelona, Spain.

Systemic inflammation (SI) is involved in the pathogenesis of acute decompensation (AD) and acute-on-chronic liver failure (ACLF) in cirrhosis. In other diseases, SI activates tryptophan (Trp) degradation through the kynurenine pathway (KP), giving rise to metabolites that contribute to multiorgan/system damage and immunosuppression. In the current study, we aimed to characterize the KP in patients with cirrhosis, in whom this pathway is poorly known. The serum levels of Trp, key KP metabolites (kynurenine and kynurenic and quinolinic acids), and cytokines (SI markers) were measured at enrollment in 40 healthy subjects, 39 patients with compensated cirrhosis, 342 with AD (no ACLF) and 180 with ACLF, and repeated in 258 patients during the 28-day follow-up. Urine KP metabolites were measured in 50 patients with ACLF. Serum KP activity was normal in compensated cirrhosis, increased in AD and further increased in ACLF, in parallel with SI; it was remarkably higher in ACLF with kidney failure than in ACLF without kidney failure in the absence of differences in urine KP activity and fractional excretion of KP metabolites. The short-term course of AD and ACLF (worsening, improvement, stable) correlated closely with follow-up changes in serum KP activity. Among patients with AD at enrollment, those with the highest baseline KP activity developed ACLF during follow-up. Among patients who had ACLF at enrollment, those with immune suppression and the highest KP activity, both at baseline, developed nosocomial infections during follow-up. Finally, higher baseline KP activity independently predicted mortality in patients with AD and ACLF. Conclusion: Features of KP activation appear in patients with AD, culminate in patients with ACLF, and may be involved in the pathogenesis of ACLF, clinical course, and mortality.
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http://dx.doi.org/10.1002/hep.30363DOI Listing
April 2019

Inhibition of Lysosome Membrane Recycling Causes Accumulation of Gangliosides that Contribute to Neurodegeneration.

Cell Rep 2018 06;23(13):3813-3826

Sorbonne Université, F-75013 Paris, France; Inserm, U1127, F-75013 Paris, France; CNRS, UMR 7225, F-75013 Paris, France; Institut du Cerveau et de la Moelle Epinière (ICM), F-75013 Paris, France. Electronic address:

Lysosome membrane recycling occurs at the end of the autophagic pathway and requires proteins that are mostly encoded by genes mutated in neurodegenerative diseases. However, its implication in neuronal death is still unclear. Here, we show that spatacsin, which is required for lysosome recycling and whose loss of function leads to hereditary spastic paraplegia 11 (SPG11), promotes clearance of gangliosides from lysosomes in mouse and human SPG11 models. We demonstrate that spatacsin acts downstream of clathrin and recruits dynamin to allow lysosome membrane recycling and clearance of gangliosides from lysosomes. Gangliosides contributed to the accumulation of autophagy markers in lysosomes and to neuronal death. In contrast, decreasing ganglioside synthesis prevented neurodegeneration and improved motor phenotype in a SPG11 zebrafish model. Our work reveals how inhibition of lysosome membrane recycling leads to the deleterious accumulation of gangliosides, linking lysosome recycling to neurodegeneration.
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http://dx.doi.org/10.1016/j.celrep.2018.05.098DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6045775PMC
June 2018

Low-Protein Diet Induces IRE1α-Dependent Anticancer Immunosurveillance.

Cell Metab 2018 04;27(4):828-842.e7

Université Côte d'Azur, INSERM U1065, C3M, 151 route de St Antoine de Ginestière, BP 23194, 06204 Nice, France. Electronic address:

Dietary restriction (DR) was shown to impact on tumor growth with very variable effects depending on the cancer type. However, how DR limits cancer progression remains largely unknown. Here, we demonstrate that feeding mice a low-protein (Low PROT) isocaloric diet but not a low-carbohydrate (Low CHO) diet reduced tumor growth in three independent mouse cancer models. Surprisingly, this effect relies on anticancer immunosurveillance, as depleting CD8 T cells, antigen-presenting cells (APCs), or using immunodeficient mice prevented the beneficial effect of the diet. Mechanistically, we established that a Low PROT diet induces the unfolded protein response (UPR) in tumor cells through the activation of IRE1α and RIG1 signaling, thereby resulting in cytokine production and mounting an efficient anticancer immune response. Collectively, our data suggest that a Low PROT diet induces an IRE1α-dependent UPR in cancer cells, enhancing a CD8-mediated T cell response against tumors.
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http://dx.doi.org/10.1016/j.cmet.2018.02.009DOI Listing
April 2018

Detection of secondary biomarker of met-eGH as a strategy to screen for somatotropin misuse in horseracing.

Analyst 2008 Feb 21;133(2):270-6. Epub 2007 Dec 21.

LABERCA, Ecole Nationale Vétérinaire de Nantes, Nantes, France.

Since the Australian commercialisation of the recombinant equine growth hormone (reGH) in 1998 (EquiGen-5), Bresagen), this reGH, which differs only from eGH by an additional methionine at the N-terminal end (met-eGH), is worldwide suspected to be administered to racehorses as a doping agent. Indeed, the use of this biological drug is considered as a threat to horseracing since it acts both on growth, development or reproductive functions, and on the improvement of performances. In this work, we describe two reliable techniques based on surface plasmon resonance biosensor immunoassay (SPR-BIA) and solid-phase enzyme-linked immunosorbent assay (ELISA) as new, rapid and efficient long-term screening methods applicable to horseracing antidoping analysis. The ELISA and SPR-BIA tests were applied to octanoic acid purified IgGs from serum/plasma samples collected on two thoroughbreds treated with recombinant equine growth hormone for a period of two weeks. The first kinetic study of serum/plasma antibodies raised as a consequence of recombinant equine growth hormone administrations, which allows the detection from eight days up to 200 days after the beginning of the treatment, was performed. In order to trace the occurrence of anti-reGH antibodies in routine analysis and to monitor the animal level exposure to this forbidden molecule, a random population study was conducted on 233 post-race horses.
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http://dx.doi.org/10.1039/b713712eDOI Listing
February 2008