Publications by authors named "Marie Joncquel-Chevalier Curt"

22 Publications

  • Page 1 of 1

Very High Plasma Homocysteine without Malnutrition or Inherited Disorder.

Clin Chem 2020 Nov;66(11):1468-1469

CHU Lille, Service d'Hormonologie, Métabolisme, Nutrition et Oncologie, Lille, France.

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http://dx.doi.org/10.1093/clinchem/hvaa070DOI Listing
November 2020

Plasma BCAA Changes in Patients With NAFLD Are Sex Dependent.

J Clin Endocrinol Metab 2020 07;105(7)

University of Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, Lille, France.

Context: Plasma branched chain amino acid (BCAA) concentrations correlate positively with body mass index (BMI), measures of insulin resistance (IR), and severity of nonalcoholic fatty liver disease (NAFLD). Moreover, plasma BCAA concentrations also differ between the sexes, which display different susceptibilities to cardio-metabolic diseases.

Objective: Assess whether plasma BCAA concentrations associate with NAFLD severity independently of BMI, IR, and sex.

Patients: Patients visiting the obesity clinic of the Antwerp University Hospital were consecutively recruited from 2006 to 2014.

Design And Setting: A cross-sectional study cohort of 112 obese patients (59 women and 53 men) was divided into 4 groups according to NAFLD severity. Groups were matched for sex, age, BMI, homeostatic model assessment of IR, and hemoglobin A1c.

Main Outcome Measures: Fasting plasma BCAA concentrations were measured by tandem mass spectrometry using the aTRAQ™ method.

Results: In the study cohort, a modest positive correlation was observed between plasma BCAA concentrations and NAFLD severity, as well as a strong effect of sex on plasma BCAA levels. Subgroup analysis by sex revealed that while plasma BCAA concentrations increased with severity of NAFLD in women, they tended to decrease in men. Additionally, only women displayed significantly increased plasma BCAAs with increasing fibrosis.

Conclusion: Plasma BCAA concentrations display sex-dimorphic changes with increasing severity of NAFLD, independently of BMI, IR, and age. Additionally, plasma BCAA are associated with significant fibrosis in women, but not in men. These results highlight the importance of a careful consideration of sex as a major confounding factor in cross-sectional studies of NAFLD.
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http://dx.doi.org/10.1210/clinem/dgaa175DOI Listing
July 2020

Abnormal Ketone Bodies in a 22-Month-Old Boy Presenting with Recurrent Vomiting and Metabolic Acidosis.

Clin Chem 2019 11;65(11):1460-1462

CHU Lille, Centre de Biologie Pathologie Génétique, UF Métabolisme Général et Maladies Rares, F-59000 Lille, France;

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http://dx.doi.org/10.1373/clinchem.2019.306712DOI Listing
November 2019

The Case | Pseudorenal failure with metabolic acidosis in a 34-year-old woman.

Kidney Int 2019 08;96(2):527-528

Service de Néphrologie et Transplantation, Hôpital Huriez, Centre Hospitalier Universitaire de Lille, Lille, France.

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http://dx.doi.org/10.1016/j.kint.2019.02.025DOI Listing
August 2019

Glucose metabolism and NRF2 coordinate the antioxidant response in melanoma resistant to MAPK inhibitors.

Cell Death Dis 2018 02 27;9(3):325. Epub 2018 Feb 27.

Univ. Lille, INSERM, UMR-S1172, Jean Pierre Aubert Research Centre, 59045, Lille, France.

Targeted therapies as BRAF and MEK inhibitor combination have been approved as first-line treatment for BRAF-mutant melanoma. However, disease progression occurs in most of the patients within few months of therapy. Metabolic adaptations have been described in the context of acquired resistance to BRAF inhibitors (BRAFi). BRAFi-resistant melanomas are characterized by an increase of mitochondrial oxidative phosphorylation and are more prone to cell death induced by mitochondrial-targeting drugs. BRAFi-resistant melanomas also exhibit an enhancement of oxidative stress due to mitochondrial oxygen consumption increase. To understand the mechanisms responsible for survival of BRAFi-resistant melanoma cells in the context of oxidative stress, we have established a preclinical murine model that accurately recapitulates in vivo the acquisition of resistance to MAPK inhibitors including several BRAF or MEK inhibitors alone and in combination. Using mice model and melanoma cell lines generated from mice tumors, we have confirmed that the acquisition of resistance is associated with an increase in mitochondrial oxidative phosphorylation as well as the importance of glutamine metabolism. Moreover, we have demonstrated that BRAFi-resistant melanoma can adapt mitochondrial metabolism to support glucose-derived glutamate synthesis leading to increase in glutathione content. Besides, BRAFi-resistant melanoma exhibits a strong activation of NRF-2 pathway leading to increase in the pentose phosphate pathway, which is involved in the regeneration of reduced glutathione, and to increase in xCT expression, a component of the xc-amino acid transporter essential for the uptake of cystine required for intracellular glutathione synthesis. All these metabolic modifications sustain glutathione level and contribute to the intracellular redox balance to allow survival of BRAFi-resistant melanoma cells.
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http://dx.doi.org/10.1038/s41419-018-0340-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5832419PMC
February 2018

Fluxomic assay-assisted diagnosis orientation in a cohort of 11 patients with myopathic form of CPT2 deficiency.

Mol Genet Metab 2018 04 12;123(4):441-448. Epub 2018 Feb 12.

Department of Biochemistry and Molecular Biology, Laboratory of Endocrinology, Metabolism-Nutrition, Oncology, Biology Pathology Center, CHRU Lille, 59037 Lille, France; Univ. Lille, RADEME - Maladies RAres du Développement et du Métabolisme: du phénotype au génotype et à la Fonction, Lille, EA 7364, France; Inserm, Lille, France. Electronic address:

Carnitine palmitoyltransferase type 2 (CPT2) deficiency, a mitochondrial fatty acid oxidation disorder (MFAOD), is a cause of myopathy in its late clinical presentation. As for other MFAODs, its diagnosis may be evocated when blood acylcarnitine profile is abnormal. However, a lack of abnormalities or specificity in this profile is not exclusive of CPT2 deficiency. Our retrospective study reports clinical and biological data in a cohort of 11 patients with circulating acylcarnitine profile unconclusive enough for a specific diagnosis orientation. In these patients, CPT2 gene studies was prompted by prior fluxomic explorations of mitochondrial β-oxidation on intact whole blood cells incubated with pentadeuterated ([16-H, 15-H])-palmitate. Clinical indication for fluxomic explorations was at least one acute rhabdomyolysis episode complicated, in 5 of 11 patients, by acute renal failure. Major trigger of rhabdomyolysis was febrile infection. In all patients, fluxomic data indicated deficient CPT2 function showing normal deuterated palmitoylcarnitine (C16-Cn) formation rates associated with increased ratios between generated C16-Cn and downstream deuterated metabolites (Σ deuterated C2-Cn to C14-Cn). Subsequent gene studies showed in all patients pathogenic gene variants in either homozygous or compound heterozygous forms. Consistent with literature data, allelic frequency of the c.338C > T[p.Ser113Leu] mutation amounted to 68.2% in our cohort. Other missense mutations included c.149C > A[p.Pro50His] (9%), c.200C > G[p.Ala200Gly] (4.5%) and previously unreported c.1171A > G[p.ser391Gly] (4.5%) and c.1420G > C[p.Ala474Pro] (4.5%) mutations. Frameshift c.1666-1667delTT[p.Leu556val*16] mutation (9%) was observed in two patients unknown to be related.
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http://dx.doi.org/10.1016/j.ymgme.2018.02.005DOI Listing
April 2018

Functional assessment of creatine transporter in control and X-linked SLC6A8-deficient fibroblasts.

Mol Genet Metab 2018 04 16;123(4):463-471. Epub 2018 Feb 16.

Department of Biochemistry and Molecular Biology, Laboratory of Hormonology, Metabolism-Nutrition & Oncology (HMNO), Center of Biology and Pathology (CBP) Pierre-Marie Degand, CHRU, Lille, France; Inserm, Lille, France; Université de Lyon, INSERM U1060 CarMeN, Lyon, France.; Univ. Lille, RADEME - Maladies RAres du Développement et du Métabolisme : du phénotype au génotype et à la Fonction, Lille, EA 7364, France. Electronic address:

Creatine transporter is currently the focus of renewed interest with emerging roles in brain neurotransmission and physiology, and the bioenergetics of cancer metastases. We here report on amendments of a standard creatine uptake assay which might help clinical chemistry laboratories to extend their current range of measurements of creatine and metabolites in body fluids to functional enzyme explorations. In this respect, short incubation times and the use of a stable-isotope-labeled substrate (D-creatine) preceded by a creatine wash-out step from cultured fibroblast cells by removal of fetal bovine serum (rich in creatine) from the incubation medium are recommended. Together, these measures decreased, by a first order of magnitude, creatine concentrations in the incubation medium at the start of creatine-uptake studies and allowed to functionally discriminate between 4 hemizygous male and 4 heterozygous female patients with X-linked SLC6A8 deficiency, and between this cohort of eight patients and controls. The functional assay corroborated genetic diagnosis of SLC6A8 deficiency. Gene anomalies in our small cohort included splicing site (c.912G > A [p.Ile260_Gln304del], c.778-2A > G and c.1495 + 2 T > G), substitution (c.407C > T) [p.Ala136Val] and deletion (c.635_636delAG [p.Glu212Valfs*84] and c.1324delC [p.Gln442Lysfs*21]) variants with reduced creatine transporter function validating their pathogenicity, including that of a previously unreported c.1324delC variant. The present assay adaptations provide an easy, reliable and discriminative manner for exploring creatine transporter activity and disease variations. It might apply to drug testing or other evaluations in the genetic and metabolic horizons covered by the emerging functions of creatine and its transporter, in a way, however, requiring and completed by additional studies on female patients and blood-brain barrier permeability properties of selected compounds. As a whole, the proposed assay of creatine transporter positively adds to currently existing measurements of this transporter activity, and determining on a large scale the extent of its exact suitability to detect female patients should condition in the future its transfer in clinical practice.
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http://dx.doi.org/10.1016/j.ymgme.2018.02.010DOI Listing
April 2018

Association Between Low Plasma Level of Citrulline Before Allogeneic Hematopoietic Cell Transplantation and Severe Gastrointestinal Graft vs Host Disease.

Clin Gastroenterol Hepatol 2018 06 16;16(6):908-917.e2. Epub 2017 Dec 16.

University of Lille, Inserm, CHU Lille, U995 - LIRIC - Lille Inflammation Research International Center, Lille, France; University of Lille, CHU Lille, Department of Nutrition, Lille, France. Electronic address:

Background & Aims: The gastrointestinal form of acute graft vs host disease increases morbidity and mortality following allogeneic hematopoietic cell transplantation. Plasma levels of citrulline, a non-proteinogenic amino acid, indicate functional enterocyte mass. We measured citrulline in patients before allogeneic hematopoietic cell transplantation and investigated its association with incidence and severity of gastrointestinal graft vs host disease.

Methods: We performed a retrospective study with 191 patients (69 women, 122 men; median age of 52 years) who underwent allogeneic hematopoietic cell transplantation for hematological malignancies at a tertiary center of France from January 2013 through April 2015. Levels of citrulline in plasma samples collected 30 days before graft infusion were measured by high performance liquid chromatography with tandem mass spectrometry. We assigned patients to groups with a high level of citrulline (>26 μmol/L) or low level of citrulline (≤26 μmol/L). The primary outcomes were difference between groups in incidence of stage 2-4 gastrointestinal graft vs host disease, death without hematological disease relapse (non-relapse mortality), relapse of the hematological disease, and overall survival through 2 years after transplantation.

Results: Ninety-six patients (50%) developed acute graft vs host disease and 37 (19%) developed a gastrointestinal form. Among patients with gastrointestinal involvement, 33 patients (89%) had stage 2-4 gastrointestinal graft vs host disease. In univariable analysis, low level of citrulline associated with higher cumulative incidence of stage 2-4 gastrointestinal graft vs host disease, non-relapse mortality, and shorter overall survival. In multivariable analysis, low level of citrulline was the only risk factor independently associated with stage 2-4 gastrointestinal graft vs host disease (hazard ratio, 3.06; 95% CI, 1.37-6.85; P = .007); it also associated with increased non-relapse mortality (hazard ratio, 2.29; 95% CI, 1.24-4.22; P = .008).

Conclusions: In a retrospective study with 191 patients, we associated a low plasma level of citrulline before allogeneic hematopoietic cell transplantation with a higher risk for stage 2-4 gastrointestinal graft vs host disease and non-relapse mortality. This marker might be used to manage patients before allogeneic hematopoietic cell transplantation.
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http://dx.doi.org/10.1016/j.cgh.2017.12.024DOI Listing
June 2018

Fluxomic evidence for impaired contribution of short-chain acyl-CoA dehydrogenase to mitochondrial palmitate β-oxidation in symptomatic patients with ACADS gene susceptibility variants.

Clin Chim Acta 2017 Aug 19;471:101-106. Epub 2017 May 19.

Department of Biochemistry and Molecular Biology, Laboratory of Hormonology, Metabolism-Nutrition & Oncology (HMNO), Center of Biology and Pathology (CBP) Pierre-Marie Degand, CHRU Lille, France; Univ. Lille, EA 7364 - RADEME - Maladies RAres du Développement et du Métabolisme: du phénotype au génotype et à la Fonction, Lille, France; Inserm, Lille, France. Electronic address:

Background: Despite ACADS (acyl-CoA dehydrogenase, short-chain) gene susceptibility variants (c.511C>T and c.625G>A) are considered to be non-pathogenic, encoded proteins are known to exhibit altered kinetics. Whether or not, they might affect overall fatty acid β-oxidation still remains, however, unclear.

Methods: De novo biosynthesis of acylcarnitines by whole blood samples incubated with deuterated palmitate (16-H,15-H-palmitate) is suitable as a fluxomic exploration to distinguish between normal and disrupted β-oxidation, abnormal profiles and ratios of acylcarnitines with different chain-lengths being indicative of the site for enzymatic blockade. Determinations in 301 control subjects of ratios between deuterated butyrylcarnitine and sum of deuterated C2 to C14 acylcarnitines served here as reference values to state specifically functional SCAD impairment in patients addressed for clinical and/or biological suspicion of a β-oxidation disorder.

Results: Functional SCAD impairment was found in 39 patients. The 27 patients accepting subsequent gene studies were all positive for ACADS mutations. Twenty-six of 27 patients were positive for c.625G>A variant. Twenty-three of 27 patients harbored susceptibility variants as sole ACADS alterations (18 homozygous and 3 heterozygous for c.625G>A, 2 compound heterozygous for c.625G>A/c.511C>T).

Conclusion: Our present fluxomic assessment of SCAD suggests a link between ACADS susceptibility variants and abnormal β-oxidation consistent with known altered kinetics of these variants.
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http://dx.doi.org/10.1016/j.cca.2017.05.026DOI Listing
August 2017

A fast method for high resolution oxymetry study of skeletal muscle mitochondrial respiratory chain complexes.

Anal Biochem 2017 07 26;528:57-62. Epub 2017 Apr 26.

Department of Biochemistry and Molecular Biology, Laboratory of Hormonology, Metabolism-Nutrition & Oncology (HMNO), Center of Biology and Pathology (CBP) Pierre-Marie Degand, CHRU Lille, France; Univ. Lille, EA 7364 - RADEME - Maladies RAres du Développement et du Métabolisme: du phénotype au génotype et à la Fonction, Lille, France; Inserm, Lille, France. Electronic address:

High resolution oxymetry study (HROS) of skeletal muscle usually requires 90-120 min preparative phase (dissection, permeabilization and washing). This work reports on the suitability of a rapid muscle preparation which by-passes this long preparation. For a few seconds only, muscle biopsy from pigs is submitted to gentle homogenization at 8000 rotations per minute using an ultra-dispersor apparatus. Subsequent HROS is performed using FCCP instead of ADP, compounds crossing and not plasma membrane, respectively. This simplified procedure compares favorably with classical (permeabilized fibers) HROS in terms of respiratory chain complex activities. Mitochondria from cells undergoing ultradispersion were functionally preserved as attested by relative inefficacy of added cytochrome C (not crossing intact mitochondrial outer membrane) to stimulate mitochondrial respiration. Responsiveness of respiration to ADP (in the absence of FCCP) suggested that these intact mitochondria were outside cells disrupted by ultradispersion or within cells permeated by this procedure.
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http://dx.doi.org/10.1016/j.ab.2017.04.015DOI Listing
July 2017

Citrulline and Monocyte-Derived Macrophage Reactivity before Conditioning Predict Acute Graft-versus-Host Disease.

Biol Blood Marrow Transplant 2017 Jun 2;23(6):913-921. Epub 2017 Mar 2.

LIRIC UMR 995 Inserm, University of Lille, Lille, France; Department of Nutrition, CHU Lille, Lille, France. Electronic address:

During conditioning, intestinal damage induces microbial translocation which primes macrophage reactivity and leads to donor-derived T cell stimulation. Little is known about the role of intestinal health and macrophage reactivity before conditioning in the development of acute graft-versus-host disease (aGVHD) in patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT). We assessed (1) citrulline, a surrogate marker of functional enterocyte mass and (2) circulating monocyte-derived macrophage reactivity, before allo-HCT. Forty-seven consecutive patients were prospectively included. Citrulline levels from blood samples withdrawn 30 days before transplantation were assessed using liquid chromatography combined with mass spectrometry. Monocyte-derived macrophages were isolated and incubated with 5 pathogen-associated molecular patterns: lipopolysaccharide, PamCSK4, flagellin, muramyl dipeptide, and curdlan. Multiplex fluorescent immunoassay on culture supernatant assessed levels of TNF-α, IL-1β, IL-6, and IL-10 in each condition. Citrulline and cytokine levels were analyzed relatively to aGVHD onset within 100 days after transplantation. Citrulline levels were lower in the aGVHD group (n = 20) than in the no-aGVHD group (n = 27) (P = .005). Conversely, IL-6 and IL-10 were greater in aGVHD group, especially after curdlan stimulation (P = .005 and P = .012). Citrulline levels ≤20 µmol/L, IL-6 ≥ 332 pg/mL, and IL-10 ≥ 90 pg/mL were associated with aGVHD development (log-rank test, P = .002, P = .041, and P < .0001, respectively). In multivariate analysis, IL-10 ≥ 90 pg/mL, myeloablative conditioning, and citrulline ≤20 µmol/L remained independent factors of aGVHD development (hazard ratio [HR],  8.18, P = .0003; HR, 4.28, P = .006; and HR, 4.43, P = .01, respectively). Preconditioning citrulline and monocyte-derived macrophage reactivity are objective surrogate markers suitable to identify patients at risk of developing aGVHD. This work highlights the influence of preconditioning status in aGVHD development.
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http://dx.doi.org/10.1016/j.bbmt.2017.03.005DOI Listing
June 2017

Creatine biosynthesis and transport in health and disease.

Biochimie 2015 Dec 2;119:146-65. Epub 2015 Nov 2.

Biochemistry and Molecular Biology, Hormonology-Metabolism-Nutrition & Oncology (HMNO), Center of Biology & Pathology (CBP) Pierre-Marie Degand, CHRU Lille, 59037 Lille, France; RADEME Research Team for Rare Metabolic and Developmental Diseases, EA 7364, Université Lille 2, Lille, France; Inserm, Lille, France. Electronic address:

Creatine is physiologically provided equally by diet and by endogenous synthesis from arginine and glycine with successive involvements of arginine glycine amidinotransferase [AGAT] and guanidinoacetate methyl transferase [GAMT]. A specific plasma membrane transporter, creatine transporter [CRTR] (SLC6A8), further enables cells to incorporate creatine and through uptake of its precursor, guanidinoacetate, also directly contributes to creatine biosynthesis. Breakthrough in the role of creatine has arisen from studies on creatine deficiency disorders. Primary creatine disorders are inherited as autosomal recessive (mutations affecting GATM [for glycine-amidinotransferase, mitochondrial]) and GAMT genes) or X-linked (SLC6A8 gene) traits. They have highlighted the role of creatine in brain functions altered in patients (global developmental delay, intellectual disability, behavioral disorders). Creatine modulates GABAergic and glutamatergic cerebral pathways, presynaptic CRTR (SLC6A8) ensuring re-uptake of synaptic creatine. Secondary creatine disorders, addressing other genes, have stressed the extraordinary imbrication of creatine metabolism with many other cellular pathways. This high dependence on multiple pathways supports creatine as a cellular sensor, to cell methylation and energy status. Creatine biosynthesis consumes 40% of methyl groups produced as S-adenosylmethionine, and creatine uptake is controlled by AMP activated protein kinase, a ubiquitous sensor of energy depletion. Today, creatine is considered as a potential sensor of cell methylation and energy status, a neurotransmitter influencing key (GABAergic and glutamatergic) CNS neurotransmission, therapeutic agent with anaplerotic properties (towards creatine kinases [creatine-creatine phosphate cycle] and creatine neurotransmission), energetic and antioxidant compound (benefits in degenerative diseases through protection against energy depletion and oxidant species) with osmolyte behavior (retention of water by muscle). This review encompasses all these aspects by providing an illustrated metabolic account for brain and body creatine in health and disease, an algorithm to diagnose metabolic and gene bases of primary and secondary creatine deficiencies, and a metabolic exploration by (1)H-MRS assessment of cerebral creatine levels and response to therapeutic measures.
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http://dx.doi.org/10.1016/j.biochi.2015.10.022DOI Listing
December 2015

Alteration or adaptation, the two roads for human gastric mucin glycosylation infected by Helicobacter pylori.

Glycobiology 2015 Jun 16;25(6):617-31. Epub 2015 Jan 16.

Univ Lille Nord de France, Lille F-59000, France USTL, UGSF, IFR 147, Villeneuve d'Ascq F-59650, France CNRS, UMR 8576, Villeneuve d'Ascq F-59650, France

Helicobacter pylori is a Gram-negative bacterium that colonizes the mucus niche of the gastric mucosa and infects more than half of the world's human population. Chronic infection may cause gastritis, duodenal ulcer, intestinal metaplasia or gastric cancer. In the stomach, H. pylori interacts with O-glycans of gastric mucins but the mechanism by which the bacteria succeed in altering the mucosa remains mainly unknown. To better understand the physiopathology of the infection, inhibitory adhesion assays were performed with various O-glycans expressed by human gastric mucins, and topographic expression of gastric mucins MUC5AC and MUC6 was analyzed for healthy uninfected individuals, for infected asymptomatic individuals and for patients infected by H. pylori and having the incomplete type of intestinal metaplasia. The glycosylation of the gastric mucosa of asymptomatic individuals infected by H. pylori was determined and compared with the glycosylation pattern found for patients with the incomplete type of intestinal metaplasia. Results show that H. pylori manages to modulate host's glycosylation during the course of infection in order to create a favorable niche, whereas asymptomatic infected individuals seem to counteract further steps of infection development by adapting their mucus glycosylation.
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http://dx.doi.org/10.1093/glycob/cwv004DOI Listing
June 2015

Valproate adverse effects on creatine metabolism and transport in a patient under drug therapy.

Iran J Neurol 2014 Apr;13(2):108-9

Department of Biology, School of Medicine, Laboratory of Biochemistry, Rabta Hospital, Jebbari, 1007 Tunis, Tunisia.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4187329PMC
April 2014

The lacdiNAc-specific adhesin LabA mediates adhesion of Helicobacter pylori to human gastric mucosa.

J Infect Dis 2014 Oct 21;210(8):1286-95. Epub 2014 Apr 21.

Univ Lille Nord de France USTL, UGSF, IFR 147 CNRS, UMR 8576.

Adhesion of Helicobacter pylori to the gastric mucosa is a necessary prerequisite for the pathogenesis of H. pylori-related diseases. In this study, we investigated the GalNAcβ1-4GlcNAc motif (also known as N,N'-diacetyllactosediamine [lacdiNAc]) carried by MUC5AC gastric mucins as the target for bacterial binding to the human gastric mucosa. The expression of LacdiNAc carried by gastric mucins was correlated with H. pylori localization, and all strains tested adhered significantly to this motif. Proteomic analysis and mutant construction allowed the identification of a yet uncharacterized bacterial adhesin, LabA, which specifically recognizes lacdiNAc. These findings unravel a target of adhesion for H. pylori in addition to moieties recognized by the well-characterized adhesins BabA and SabA. Localization of the LabA target, restricted to the gastric mucosa, suggests a plausible explanation for the tissue tropism of these bacteria. These results pave the way for the development of alternative strategies against H. pylori infection, using adherence inhibitors.
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http://dx.doi.org/10.1093/infdis/jiu239DOI Listing
October 2014

Creatine and guanidinoacetate reference values in a French population.

Mol Genet Metab 2013 Nov 16;110(3):263-7. Epub 2013 Sep 16.

Département de Biochimie et Biologie Moléculaire, Laboratoire d'Hormonologie, Metabolisme-Nutrition & Oncologie (HMNO) - Centre de Biologie et Pathologie (CBP) Pierre-Marie Degand, CHRU Lille, 59037 Lille, France.

Creatine and guanidinoacetate are biomarkers of creatine metabolism. Their assays in body fluids may be used for detecting patients with primary creatine deficiency disorders (PCDD), a class of inherited diseases. Their laboratory values in blood and urine may vary with age, requiring that reference normal values are given within the age range. Despite the long known role of creatine for muscle physiology, muscle signs are not necessarily the major complaint expressed by PCDD patients. These disorders drastically affect brain function inducing, in patients, intellectual disability, autistic behavior and other neurological signs (delays in speech and language, epilepsy, ataxia, dystonia and choreoathetosis), being a common feature the drop in brain creatine content. For this reason, screening of PCDD patients has been repeatedly carried out in populations with neurological signs. This report is aimed at providing reference laboratory values and related age ranges found for a large scale population of patients with neurological signs (more than 6 thousand patients) previously serving as a background population for screening French patients with PCDD. These reference laboratory values and age ranges compare rather favorably with literature values for healthy populations. Some differences are also observed, and female participants are discriminated from male participants as regards to urine but not blood values including creatine on creatinine ratio and guanidinoacetate on creatinine ratio values. Such gender differences were previously observed in healthy populations; they might be explained by literature differential effects of testosterone and estrogen in adolescents and adults, and by estrogen effects in prepubertal age on SLC6A8 function. Finally, though they were acquired on a population with neurological signs, the present data might reasonably serve as reference laboratory values in any future medical study exploring abnormalities of creatine metabolism and transport.
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http://dx.doi.org/10.1016/j.ymgme.2013.09.005DOI Listing
November 2013

Virulent Shigella flexneri affects secretion, expression, and glycosylation of gel-forming mucins in mucus-producing cells.

Infect Immun 2013 Oct 22;81(10):3632-43. Epub 2013 Jul 22.

Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, Paris, France.

Mucin glycoproteins are secreted in large amounts by the intestinal epithelium and constitute an efficient component of innate immune defenses to promote homeostasis and protect against enteric pathogens. In this study, our objective was to investigate how the bacterial enteropathogen Shigella flexneri, which causes bacillary dysentery, copes with the mucin defense barrier. We report that upon in vitro infection of mucin-producing polarized human intestinal epithelial cells, virulent S. flexneri manipulates the secretion of gel-forming mucins. This phenomenon, which is triggered only by virulent strains, results in accumulation of mucins at the cell apical surface, leading to the appearance of a gel-like structure that favors access of bacteria to the cell surface and the subsequent invasion process. We identify MUC5AC, a gel-forming mucin, as a component of this structure. Formation of this gel does not depend on modifications of electrolyte concentrations, induction of trefoil factor expression, endoplasmic reticulum stress, or response to unfolded proteins. In addition, transcriptional and biochemical analyses of infected cells reveal modulations of mucin gene expression and modifications of mucin glycosylation patterns, both of which are induced by virulent bacteria in a type III secretion system-dependent manner. Thus, S. flexneri has developed a dedicated strategy to alter the mucus barrier by targeting key elements of the gel-forming capacity of mucins: gene transcription, protein glycosylation, and secretion.
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http://dx.doi.org/10.1128/IAI.00551-13DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3811771PMC
October 2013

Bacteroides thetaiotaomicron and Faecalibacterium prausnitzii influence the production of mucus glycans and the development of goblet cells in the colonic epithelium of a gnotobiotic model rodent.

BMC Biol 2013 May 21;11:61. Epub 2013 May 21.

INRA, UMR 1319 MICALIS, AgroParisTech, Domaine de Vilvert, Jouy-en-Josas, France.

Background: The intestinal mucus layer plays a key role in the maintenance of host-microbiota homeostasis. To document the crosstalk between the host and microbiota, we used gnotobiotic models to study the influence of two major commensal bacteria, Bacteroides thetaiotaomicron and Faecalibacterium prausnitzii, on this intestinal mucus layer. B. thetaiotaomicron is known to use polysaccharides from mucus, but its effect on goblet cells has not been addressed so far. F. prausnitzii is of particular physiological importance because it can be considered as a sensor and a marker of human health. We determined whether B. thetaiotaomicron affected goblet cell differentiation, mucin synthesis and glycosylation in the colonic epithelium. We then investigated how F. prausnitzii influenced the colonic epithelial responses to B. thetaiotaomicron.

Results: B. thetaiotaomicron, an acetate producer, increased goblet cell differentiation, expression of mucus-related genes and the ratio of sialylated to sulfated mucins in mono-associated rats. B. thetaiotaomicron, therefore, stimulates the secretory lineage, favoring mucus production. When B. thetaiotaomicron was associated with F. prausnitzii, an acetate consumer and a butyrate producer, the effects on goblet cells and mucin glycosylation were diminished. F. prausnitzii, by attenuating the effects of B. thetaiotaomicron on mucus, may help the epithelium to maintain appropriate proportions of different cell types of the secretory lineage. Using a mucus-producing cell line, we showed that acetate up-regulated KLF4, a transcription factor involved in goblet cell differentiation.

Conclusions: B. thetaiotaomicron and F. prausnitzii, which are metabolically complementary, modulate, in vivo, the intestinal mucus barrier by modifying goblet cells and mucin glycosylation. Our study reveals the importance of the balance between two main commensal bacteria in maintaining colonic epithelial homeostasis via their respective effects on mucus.
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http://dx.doi.org/10.1186/1741-7007-11-61DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3673873PMC
May 2013

Screening for primary creatine deficiencies in French patients with unexplained neurological symptoms.

Orphanet J Rare Dis 2012 Dec 13;7:96. Epub 2012 Dec 13.

Hospices Civils de Lyon, Service Maladies Héréditaires du Métabolisme et Dépistage Néonatal, Groupement Hospitalier, Bron, France.

A population of patients with unexplained neurological symptoms from six major French university hospitals was screened over a 28-month period for primary creatine disorder (PCD). Urine guanidinoacetate (GAA) and creatine:creatinine ratios were measured in a cohort of 6,353 subjects to identify PCD patients and compile their clinical, 1H-MRS, biochemical and molecular data. Six GAMT [N-guanidinoacetatemethyltransferase (EC 2.1.1.2)] and 10 X-linked creatine transporter (SLC6A8) but no AGAT (GATM) [L-arginine/glycine amidinotransferase (EC 2.1.4.1)] deficient patients were identified in this manner. Three additional affected sibs were further identified after familial inquiry (1 brother with GAMT deficiency and 2 brothers with SLC6A8 deficiency in two different families). The prevalence of PCD in this population was 0.25% (0.09% and 0.16% for GAMT and SLC6A8 deficiencies, respectively). Seven new PCD-causing mutations were discovered (2 nonsense [c.577C > T and c.289C > T] and 1 splicing [c.391 + 15G > T] mutations for the GAMT gene and, 2 missense [c.1208C > A and c.926C > A], 1 frameshift [c.930delG] and 1 splicing [c.1393-1G > A] mutations for the SLC6A8 gene). No hot spot mutations were observed in these genes, as all the mutations were distributed throughout the entire gene sequences and were essentially patient/family specific. Approximately one fifth of the mutations of SLC6A8, but not GAMT, were attributed to neo-mutation, germinal or somatic mosaicism events. The only SLC6A8-deficient female patient in our series presented with the severe phenotype usually characterizing affected male patients, an observation in agreement with recent evidence that is in support of the fact that this X-linked disorder might be more frequent than expected in the female population with intellectual disability.
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http://dx.doi.org/10.1186/1750-1172-7-96DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3552865PMC
December 2012

Guanidinoacetate methyltransferase (GAMT) deficiency in two Tunisian siblings: clinical and biochemical features.

Clin Lab 2012 ;58(5-6):427-32

Laboratory of Biochemistry, Rabta Hospital, Jebbari, 1007 Tunis, Tunisia.

Background: Guanidinoacetate methyltransferase (GAMT) deficiency is a recently described disorder and few cases have been reported to date. As it is a treatable pathology, we seek to contribute to its better understanding, particularly to further elucidate its biochemical diagnosis for early treatment.

Methods: The patients, two brothers aged 13 years (P1) and 11 years (P2), have been explored for signs and symptoms suggestive of inborn errors of metabolism. The quantification of creatine (Cr), guanidinoacetate (GAA), and GAMT activity was performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Results: The two brothers presented a similar clinical picture: developmental delay, epilepsy, axial hypotonia, spastic tetraparesis, severe mental and language delay, and autistic behaviour. GAA concentrations were markedly increased in plasma and in urine [2796 and 3342 micromol/mmol creatinine (control range: 4 - 220 micromol/mmol creatinine)/14 and 29 micromol/L (control range: 0.35 - 1.8 micromol/L), respectively] while plasma and urine creatine concentrations were at the lower normal range limit. Activity of GAMT in lymphoblasts was extremely reduced (< 0.01 nmol/mg protein/hour) compared to healthy subjects. GAMT activity was found to be intermediary in patients' parents.

Conclusions: It appears that the clinical picture is heterogeneous but should be considered as potential signs of creatine metabolism disorders, however, the biochemical diagnosis is reliable as the enzyme activity is zero in most cases. To date, it is still too early to establish correlations between symptoms and biochemical profile. However, the identification of additional cases of GAMT deficiency should help elucidate such relationships and the progress of patients treated with creatine in conjunction with ornithine supplementation.
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July 2012

Almost all human gastric mucin O-glycans harbor blood group A, B or H antigens and are potential binding sites for Helicobacter pylori.

Glycobiology 2012 Sep 21;22(9):1193-206. Epub 2012 Apr 21.

Univ Lille Nord de France, F-59000 Lille, France.

Helicobacter pylori infects more than half of the world's population. Although most patients are asymptomatic, persistent infection may cause chronic gastritis and gastric cancer. Adhesion of the bacteria to the gastric mucosa is a necessary prerequisite for the pathogenesis of H. pylori-related diseases and is mediated by mucin O-glycans. In order to define which glycans may be implicated in the binding of the bacteria to the gastric mucosa in humans, we have characterized the exact pattern of glycosylation of gastric mucins. We have identified that the major component was always a core 2-based glycan carrying two blood group H antigens, whatever was the blood group of individuals. We have also demonstrated that around 80% of O-glycans carried blood group A, B or H antigens, suggesting that the variation of gastric mucin glycosylation between individuals is partly due to the blood group status. This study will help better understanding the role of O-glycans in the physiology and homeostasis of gastric mucosa. Overall, the results reported here give us the necessary background information to begin studies to determine whether individuals who express certain carbohydrate epitopes on specific mucins are predisposed to certain gastric diseases.
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http://dx.doi.org/10.1093/glycob/cws072DOI Listing
September 2012

Rise in brain GABA to further stress the metabolic link between valproate and creatine.

Mol Genet Metab 2011 Feb 14;102(2):232-4. Epub 2010 Oct 14.

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http://dx.doi.org/10.1016/j.ymgme.2010.10.006DOI Listing
February 2011