23 results on '"Boursier-Neyret C"'
Search Results
2. P.009 The peripheral serotonin pathway in major depression before and after antidepressant treatment: a case-control prospective study
- Author
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Colle, R., primary, Masson, P., additional, Verstuyft, C., additional, Feve, B., additional, Werner, E., additional, Boursier-Neyret, C., additional, Walther, B., additional, David J, D., additional, Boniface, B., additional, Falissard, B., additional, Chanson, P., additional, Corruble, E., additional, and Becquemont, L., additional
- Published
- 2019
- Full Text
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3. Determination of sulbutiamine and its disulfide derivatives in human plasma by HPLC using on-line post-column reactors and fluorimetric detection
- Author
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Gelé, P., Boursier-Neyret, C., Lesourd, M., and Sauveur, C.
- Published
- 1993
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4. Le métabolome plasmatique humain : valeurs de référence chez 800 volontaires sains ; impact du cholestérol, du genre et de l’âge
- Author
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Trabado, S., primary, Al-Salameh, A., additional, Croixmarie, V., additional, Masson, P., additional, Corruble, E., additional, Feve, B., additional, Colle, R., additional, Ripoll, L., additional, Walther, B., additional, Boursier-Neyret, C., additional, Werner, E., additional, Becquemont, L., additional, and Chanson, P., additional
- Published
- 2016
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5. Approche métabolomique pour identifier des biomarqueurs lipidiques chez la souris db/db
- Author
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Boursier-Neyret, C., primary, Croixmarie, M.V., additional, and Walther, M.B., additional
- Published
- 2012
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6. Determination of S 12024 enantiomers in human plasma by liquid chromatography after chiral pre-column derivatization
- Author
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Boursier-Neyret, C., primary, Baune, A., additional, Klippert, P., additional, Castagne, I., additional, and Sauveur, C., additional
- Published
- 1993
- Full Text
- View/download PDF
7. Simultaneous determination of ivabradine and its metabolites in human plasma by liquid chromatography-tandem mass spectrometry
- Author
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Francois-Bouchard, M., Simonin, G., Bossant, M. J., and Boursier-Neyret, C.
- Published
- 2000
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8. Determination of melatonin in biological fluids in the presence of the melatonin agonist S 20098: comparison of immunological techniques and GC-MS methods
- Author
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Simonin, G., Bru, L., Lelievre, E., Jeanniot, J.-P., Bromet, N., Walther, B., and Boursier-Neyret, C.
- Published
- 1999
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9. Peripheral tryptophan, serotonin, kynurenine, and their metabolites in major depression: A case-control study.
- Author
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Colle R, Masson P, Verstuyft C, Fève B, Werner E, Boursier-Neyret C, Walther B, David DJ, Boniface B, Falissard B, Chanson P, Corruble E, and Becquemont L
- Subjects
- 3-Hydroxyanthranilic Acid metabolism, Adult, Case-Control Studies, Cohort Studies, Female, Humans, Male, Middle Aged, Niacinamide blood, Picolinic Acids blood, Xanthurenates blood, Depressive Disorder, Major blood, Kynurenine blood, Serotonin blood, Tryptophan blood
- Abstract
Aim: Tryptophan is the sole precursor of both peripherally and centrally produced serotonin and kynurenine. In depressed patients, tryptophan, serotonin, kynurenine, and their metabolite levels remain unclear. Therefore, peripheral tryptophan and metabolites of serotonin and kynurenine were investigated extensively in 173 patients suffering from a current major depressive episode (MDE) and compared to 214 healthy controls (HC)., Methods: Fasting plasma levels of 11 peripheral metabolites were quantified: tryptophan, serotonin pathway (serotonin, its precursor 5-hydroxytryptophan and its metabolite 5-hydroxyindoleacetic acid), and kynurenine pathway (kynurenine and six of its metabolites: anthranilic acid, kynurenic acid, nicotinamide, picolinic acid, xanthurenic acid, and 3-hydroxyanthranilic acid)., Results: Sixty (34.7%) patients were antidepressant-drug free. Tryptophan levels did not differ between MDE patients and HC. Serotonin and its precursor (5-hydroxytryptophan) levels were lower in MDE patients than in HC, whereas, its metabolite (5-hydroxyindoleacetic acid) levels were within the standard range. Kynurenine and four of its metabolites (kynurenic acid, nicotinamide, picolinic acid, and xanthurenic acid) were lower in MDE patients., Conclusion: Whilst the results of this study demonstrate an association between the metabolites studied and depression, conclusions about causality cannot be made. This study uses the largest ever sample of MDE patients, with an extensive assessment of peripheral tryptophan metabolism in plasma. These findings provide new insights into the peripheral signature of MDE. The reasons for these changes should be further investigated. These results might suggest new antidepressant therapeutic strategies., (© 2019 The Authors. Psychiatry and Clinical Neurosciences © 2019 Japanese Society of Psychiatry and Neurology.)
- Published
- 2020
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10. Sphingolipid Metabolism Is Dysregulated at Transcriptomic and Metabolic Levels in the Spinal Cord of an Animal Model of Amyotrophic Lateral Sclerosis.
- Author
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Henriques A, Croixmarie V, Bouscary A, Mosbach A, Keime C, Boursier-Neyret C, Walter B, Spedding M, and Loeffler JP
- Abstract
Lipid metabolism is drastically dysregulated in amyotrophic lateral sclerosis and impacts prognosis of patients. Animal models recapitulate alterations in the energy metabolism, including hypermetabolism and severe loss of adipose tissue. To gain insight into the molecular mechanisms underlying disease progression in amyotrophic lateral sclerosis, we have performed RNA-sequencing and lipidomic profiling in spinal cord of symptomatic SOD1
G86R mice. Spinal transcriptome of SOD1G86R mice was characterized by differential expression of genes related to immune system, extracellular exosome, and lysosome. Hypothesis-driven identification of metabolites showed that lipids, including sphingomyelin(d18:0/26:1), ceramide(d18:1/22:0), and phosphatidylcholine(o-22:1/20:4) showed profound altered levels. A correlation between disease severity and gene expression or metabolite levels was found for sphingosine, ceramide(d18:1/26:0), Sgpp2, Sphk1 , and Ugt8a . Joint-analysis revealed a significant enrichment of glycosphingolipid metabolism in SOD1G86R mice, due to the down-regulation of ceramide, glucosylceramide, and lactosylceramide and the overexpression of genes involved in their recycling in the lysosome. A drug-gene interaction database was interrogated to identify potential drugs able to modulate the dysregulated genes from the signaling pathway. Our results suggest that complex lipids are pivotally changed during the first phase of motor symptoms in an animal model of amyotrophic lateral sclerosis.- Published
- 2018
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11. The human plasma-metabolome: Reference values in 800 French healthy volunteers; impact of cholesterol, gender and age.
- Author
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Trabado S, Al-Salameh A, Croixmarie V, Masson P, Corruble E, Fève B, Colle R, Ripoll L, Walther B, Boursier-Neyret C, Werner E, Becquemont L, and Chanson P
- Subjects
- Adolescent, Adult, Age Factors, Aged, Aged, 80 and over, Cross-Sectional Studies, Female, France, Healthy Volunteers, Humans, Male, Metabolomics methods, Middle Aged, Principal Component Analysis, Reference Values, Sex Characteristics, Young Adult, Biomarkers blood, Cholesterol metabolism, Metabolome
- Abstract
Metabolomic approaches are increasingly used to identify new disease biomarkers, yet normal values of many plasma metabolites remain poorly defined. The aim of this study was to define the "normal" metabolome in healthy volunteers. We included 800 French volunteers aged between 18 and 86, equally distributed according to sex, free of any medication and considered healthy on the basis of their medical history, clinical examination and standard laboratory tests. We quantified 185 plasma metabolites, including amino acids, biogenic amines, acylcarnitines, phosphatidylcholines, sphingomyelins and hexose, using tandem mass spectrometry with the Biocrates AbsoluteIDQ p180 kit. Principal components analysis was applied to identify the main factors responsible for metabolome variability and orthogonal projection to latent structures analysis was employed to confirm the observed patterns and identify pattern-related metabolites. We established a plasma metabolite reference dataset for 144/185 metabolites. Total blood cholesterol, gender and age were identified as the principal factors explaining metabolome variability. High total blood cholesterol levels were associated with higher plasma sphingomyelins and phosphatidylcholines concentrations. Compared to women, men had higher concentrations of creatinine, branched-chain amino acids and lysophosphatidylcholines, and lower concentrations of sphingomyelins and phosphatidylcholines. Elderly healthy subjects had higher sphingomyelins and phosphatidylcholines plasma levels than young subjects. We established reference human metabolome values in a large and well-defined population of French healthy volunteers. This study provides an essential baseline for defining the "normal" metabolome and its main sources of variation.
- Published
- 2017
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12. Amyotrophic lateral sclerosis and denervation alter sphingolipids and up-regulate glucosylceramide synthase.
- Author
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Henriques A, Croixmarie V, Priestman DA, Rosenbohm A, Dirrig-Grosch S, D'Ambra E, Huebecker M, Hussain G, Boursier-Neyret C, Echaniz-Laguna A, Ludolph AC, Platt FM, Walther B, Spedding M, Loeffler JP, and Gonzalez De Aguilar JL
- Subjects
- Amyotrophic Lateral Sclerosis genetics, Animals, Blotting, Western, Chromatography, High Pressure Liquid, Electromyography, Glucosyltransferases genetics, Humans, Male, Mice, Retrospective Studies, Reverse Transcriptase Polymerase Chain Reaction, Amyotrophic Lateral Sclerosis metabolism, Glucosyltransferases metabolism, Sphingolipids metabolism
- Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal adult-onset disease characterized by upper and lower motor neuron degeneration, muscle wasting and paralysis. Growing evidence suggests a link between changes in lipid metabolism and ALS. Here, we used UPLC/TOF-MS to survey the lipidome in SOD1(G86R) mice, a model of ALS. Significant changes in lipid expression were evident in spinal cord and skeletal muscle before overt neuropathology. In silico analysis also revealed appreciable changes in sphingolipids including ceramides and glucosylceramides (GlcCer). HPLC analysis showed increased amounts of GlcCer and downstream glycosphingolipids (GSLs) in SOD1(G86R) muscle compared with wild-type littermates. Glucosylceramide synthase (GCS), the enzyme responsible for GlcCer biosynthesis, was up-regulated in muscle of SOD1(G86R) mice and ALS patients, and in muscle of wild-type mice after surgically induced denervation. Conversely, inhibition of GCS in wild-type mice, following transient peripheral nerve injury, reversed the overexpression of genes in muscle involved in oxidative metabolism and delayed motor recovery. GCS inhibition in SOD1(G86R) mice also affected the expression of metabolic genes and induced a loss of muscle strength and morphological deterioration of the motor endplates. These findings suggest that GSLs may play a critical role in ALS muscle pathology and could lead to the identification of new therapeutic targets., (© The Author 2015. Published by Oxford University Press.)
- Published
- 2015
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13. Ultra performance liquid chromatography - mass spectrometry studies of formalin-induced alterations of human brain lipidome.
- Author
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Gaudin M, Panchal M, Ayciriex S, Werner E, Brunelle A, Touboul D, Boursier-Neyret C, Auzeil N, Walther B, Duyckaerts C, and Laprévote O
- Subjects
- Cryopreservation, Humans, Principal Component Analysis, Tissue Fixation, Brain Chemistry drug effects, Chromatography, High Pressure Liquid methods, Formaldehyde chemistry, Lipids analysis, Mass Spectrometry methods
- Abstract
The development of 'omics' sciences offers new opportunities for the study of neurodegenerative diseases but increases at the same time the sample demand on brain banks that collect and store valuable human post-mortem tissue. Our study aims to evaluate in lipidomics the potential of formalin-fixed tissue compared with the cryopreservation method, considered as the gold standard for biochemical research. Two complementary liquid chromatography/mass spectrometry analytical platforms were used on the basis of hybrid quadrupole time-of-flight and triple quadrupole mass spectrometers. Untargeted fingerprinting, semitargeted profiling of specific lipid classes and targeted monitoring of lipid species were performed in formalin-fixed and cryopreserved samples to provide detailed information at the molecular level on the formalin-induced alterations of the brain tissue. In vitro incubations of lipid standards were also performed to further describe the degradation processes induced by formaldehyde. Phospholipid compounds were found to be extensively hydrolysed, whilst the sphingolipid ones were preserved. N-methylation and N-formylation of amine-containing phospholipids have also been evidenced. These findings show that the potential detrimental effect of formalin on the analytes of interest must be taken into account when analysing formalin-fixed samples., (Copyright © 2014 John Wiley & Sons, Ltd.)
- Published
- 2014
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14. Optimized preprocessing of ultra-performance liquid chromatography/mass spectrometry urinary metabolic profiles for improved information recovery.
- Author
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Veselkov KA, Vingara LK, Masson P, Robinette SL, Want E, Li JV, Barton RH, Boursier-Neyret C, Walther B, Ebbels TM, Pelczer I, Holmes E, Lindon JC, and Nicholson JK
- Subjects
- Animals, Female, Male, Principal Component Analysis, Rats, Rats, Wistar, Chromatography, High Pressure Liquid methods, Metabolome, Spectrometry, Mass, Electrospray Ionization methods
- Abstract
Ultra-performance liquid chromatography coupled to mass spectrometry (UPLC/MS) has been used increasingly for measuring changes of low molecular weight metabolites in biofluids/tissues in response to biological challenges such as drug toxicity and disease processes. Typically samples show high variability in concentration, and the derived metabolic profiles have a heteroscedastic noise structure characterized by increasing variance as a function of increased signal intensity. These sources of experimental and instrumental noise substantially complicate information recovery when statistical tools are used. We apply and compare several preprocessing procedures and introduce a statistical error model to account for these bioanalytical complexities. In particular, the use of total intensity, median fold change, locally weighted scatter plot smoothing, and quantile normalizations to reduce extraneous variance induced by sample dilution were compared. We demonstrate that the UPLC/MS peak intensities of urine samples should respond linearly to variable sample dilution across the intensity range. While all four studied normalization methods performed reasonably well in reducing dilution-induced variation of urine samples in the absence of biological variation, the median fold change normalization is least compromised by the biologically relevant changes in mixture components and is thus preferable. Additionally, the application of a subsequent log-based transformation was successful in stabilizing the variance with respect to peak intensity, confirming the predominant influence of multiplicative noise in peak intensities from UPLC/MS-derived metabolic profile data sets. We demonstrate that variance-stabilizing transformation and normalization are critical preprocessing steps that can benefit greatly metabolic information recovery from such data sets when widely applied chemometric methods are used.
- Published
- 2011
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15. Beta-glucuronidase from Helix pomatia origin is not suitable for diosmetin analysis.
- Author
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Werner E, Boursier-Neyret C, and Walther B
- Subjects
- Animals, Humans, Flavonoids blood, Glucuronidase metabolism, Helix, Snails enzymology
- Published
- 2010
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16. Coordinate Transcriptomic and Metabolomic Effects of the Insulin Sensitizer Rosiglitazone on Fundamental Metabolic Pathways in Liver, Soleus Muscle, and Adipose Tissue in Diabetic db/db Mice.
- Author
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Le Bouter S, Rodriguez M, Guigal-Stephan N, Courtade-Gaïani S, Xuereb L, de Montrion C, Croixmarie V, Umbdenstock T, Boursier-Neyret C, Lonchampt M, Brun M, Dacquet C, Ktorza A, Lockhart BP, and Galizzi JP
- Abstract
Rosiglitazone (RSG), developed for the treatment of type 2 diabetes mellitus, is known to have potent effects on carbohydrate and lipid metabolism leading to the improvement of insulin sensitivity in target tissues. To further assess the capacity of RSG to normalize gene expression in insulin-sensitive tissues, we compared groups of 18-day-treated db/db mice with increasing oral doses of RSG (10, 30, and 100 mg/kg/d) with untreated non-diabetic littermates (db/+). For this aim, transcriptional changes were measured in liver, inguinal adipose tissue (IAT) and soleus muscle using microarrays and real-time PCR. In parallel, targeted metabolomic assessment of lipids (triglycerides (TGs) and free fatty acids (FFAs)) in plasma and tissues was performed by UPLC-MS methods. Multivariate analyses revealed a relationship between the differential gene expressions in liver and liver trioleate content and between blood glucose levels and a combination of differentially expressed genes measured in liver, IAT, and muscle. In summary, we have integrated gene expression and targeted metabolomic data to present a comprehensive overview of RSG-induced changes in a diabetes mouse model and improved the molecular understanding of how RSG ameliorates diabetes through its effect on the major insulin-sensitive tissues.
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- 2010
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17. Metabonomic studies on human hepatocyte in primary culture.
- Author
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Croixmarie V, Umbdenstock T, Cloarec O, Moreau A, Pascussi JM, Parmentier Y, Boursier-Neyret C, and Walther B
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- Cells, Cultured, Constitutive Androstane Receptor, Hepatocytes cytology, Hepatocytes metabolism, Humans, Mass Spectrometry methods, Models, Biological, Oximes metabolism, Phenobarbital metabolism, Pregnane X Receptor, Rifampin metabolism, Thiazoles metabolism, Hepatocytes drug effects, Metabolomics methods, Oximes pharmacology, Phenobarbital pharmacology, Receptors, Cytoplasmic and Nuclear metabolism, Receptors, Steroid metabolism, Rifampin pharmacology, Thiazoles pharmacology
- Abstract
Mechanisms involved in induction processes have been investigated using fresh human hepatocytes in culture as a cellular model and using mass spectrometry-based metabonomics as a global investigation tool. Sample preparation to data analysis have been detailed in an approach enabling to separate drug-induced (endogenous metabolites) and drug-related (drug metabolites) biomarkers for reference inducers. Rifampicin, a nuclear pregnane X receptor (PXR) ligand; CITCO, a nuclear constitutive androstane receptor (CAR) ligand; and phenobarbital, which activates both CAR and PXR, have been used. Specific intra-cellular metabolites have been isolated for rifampicin and CITCO as potential endogenous biomarkers of their respective induction mechanism. A mixture of these two types of biomarkers modified in the same way after treatment with either rifampicin or CITCO on the one hand and with phenobarbital on the other hand has been found.
- Published
- 2010
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18. Integrated comparison of drug-related and drug-induced ultra performance liquid chromatography/mass spectrometry metabonomic profiles using human hepatocyte cultures.
- Author
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Croixmarie V, Umbdenstock T, Cloarec O, Moreau A, Pascussi JM, Boursier-Neyret C, and Walther B
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- Biomarkers analysis, Constitutive Androstane Receptor, Excitatory Amino Acid Antagonists pharmacology, Hepatocytes cytology, Hepatocytes metabolism, Humans, Nucleic Acid Synthesis Inhibitors pharmacology, Chromatography, Liquid, Hepatocytes drug effects, Mass Spectrometry, Metabolomics, Oximes pharmacology, Phenobarbital pharmacology, Rifampin pharmacology, Thiazoles pharmacology
- Abstract
The biochemical variations induced in human primary hepatocyte cultures by reference activators of xenoreceptor CAR (NR1I3) and PXR (NR1I2), i.e., rifampicin, phenobarbital, and 6-(4-chlorophenyl)imidazo[2,1-b] [1,3]thiazole-5-carbaldehyde O-3,4-dichlorobenzyl) oxime (CITCO), were investigated using a global metabonomics approach. Cultured human hepatocytes were treated with the three drugs before analysis of intracellular and extracellular media by ultra performance liquid chromatography/time-of-flight-mass spectrometry (UPLC/TOF-MS) technique, in order to list endogenous compounds potentially related to a PXR or CAR induction mechanism and to identify drug metabolites related to each treatment. The emphasis was put on the quality of the analytical data (dilution/filtration strategy before data processing) and on the appropriate pattern recognition techniques. In cellular media, the most significant variations seen in the data are not related to the treatments but to the source of hepatocytes, illustrating the importance of the genetic and/or environmental background in human liver experiments. However when applying classical multivariate statistical approaches (principal component analysis (PCA) and orthogonal partial least squares (O-PLS)), the statistical weight due to drug metabolites, present only in the treated groups, hinders the interpretation because of their predominance compared to most of the changes seen in endogenous metabolites. A new statistical approach, called shared and unique structure (SUS) plot, enabling the comparison of different treatments having the same control has been applied, allowing separation of clearly exogenous variables (drug metabolites) from endogenous biomarkers. Endogenous variables (either up- or down-regulated) have been attributed specifically to the impact of rifampicin (PXR ligand), CITCO (CAR ligand), and phenobarbital (CAR and PXR activator) on the biological regulation pathways of the hepatocytes. This global approach coupled to a statistical pretreatment of the data, enabling the separate capture of both drug related and drug induced biomarkers, represents a powerful technique for future mechanistic studies using cellular tools.
- Published
- 2009
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19. Differential regulation of sinusoidal and canalicular hepatic drug transporter expression by xenobiotics activating drug-sensing receptors in primary human hepatocytes.
- Author
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Jigorel E, Le Vee M, Boursier-Neyret C, Parmentier Y, and Fardel O
- Subjects
- ATP Binding Cassette Transporter, Subfamily B, Member 1 genetics, ATP Binding Cassette Transporter, Subfamily G, Member 2, Adult, Constitutive Androstane Receptor, Hepatocytes cytology, Hepatocytes metabolism, Humans, Membrane Transport Proteins genetics, Multidrug Resistance-Associated Protein 2, Multidrug Resistance-Associated Proteins genetics, NF-E2-Related Factor 2 genetics, Neoplasm Proteins genetics, Phenobarbital pharmacology, Polychlorinated Dibenzodioxins pharmacology, Pregnane X Receptor, Pyrazines pharmacology, RNA, Messenger genetics, RNA, Messenger metabolism, Receptors, Aryl Hydrocarbon drug effects, Receptors, Aryl Hydrocarbon metabolism, Receptors, Cytoplasmic and Nuclear genetics, Receptors, Steroid genetics, Reverse Transcriptase Polymerase Chain Reaction methods, Rifampin pharmacology, Symporters genetics, Thiones, Thiophenes, Transcription Factors genetics, ATP-Binding Cassette Transporters genetics, Gene Expression Regulation drug effects, Hepatocytes drug effects, Receptors, Drug genetics, Xenobiotics pharmacology
- Abstract
Sinusoidal and canalicular hepatic drug transporters constitute key factors involved in drug elimination from liver. Regulation of their expression via activation of xenosensors, such as aryl hydrocarbon receptor (AhR), constitutive androstane receptor (CAR), pregnane X receptor (PXR), and nuclear factor E2-related factor 2 (Nrf2), remains incompletely characterized. The present study was therefore designed to carefully analyze expression of major drug transporters in primary human hepatocytes exposed to dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD) (an AhR activator), rifampicin (RIF) (a PXR activator), phenobarbital (PB) (a CAR activator), and oltipraz (OPZ) (a Nrf2 activator), using mainly reverse transcription-real time polymerase chain reaction assays. With a threshold corresponding to a 1.5-fold factor change in mRNA levels, observed in at least three of seven independent human hepatocyte cultures, efflux transporters such as MDR1, MRP2 and BCRP were up-regulated by PB, RIF, and OPZ, whereas MRP3 was induced by OPZ and RIF. MDR1 and BCRP expression was also increased by TCDD- and RIF-augmented mRNA levels of the influx transporter OATP-C. Bile acid transporters, i.e., bile salt export pump and Na(+)-taurocholate cotransporting polypeptide, and the sinusoidal transporter, OAT2, were down-regulated by all the tested chemicals. Influx transporters such as OCT1, OATP-B, and OATP8 were repressed by PB and TCDD. PB also decreased MRP6 expression, whereas mRNA levels of OCT1 and OATP8 were down-regulated by RIF and OPZ, respectively. Taken together, these data establish a complex pattern of transporter regulation by xenobiotics in human hepatocytes, in addition to interindividual variability in responsiveness. This may deserve further attention with respect to drug-drug interactions and adverse effects of hepatic drugs.
- Published
- 2006
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20. Development of an in vitro rat intestine segmental perfusion model to investigate permeability and predict oral fraction absorbed.
- Author
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Castella ME, Reist M, Mayer JM, Turban JJ, Testa B, Boursier-Neyret C, Walther B, Delbos JM, and Carrupt PA
- Subjects
- Animals, Antipyrine metabolism, Dealkylation, In Vitro Techniques, Male, Models, Animal, Naproxen metabolism, Perfusion instrumentation, Permeability, Rats, Rats, Sprague-Dawley, Testosterone metabolism, Verapamil analogs & derivatives, Verapamil metabolism, Intestinal Absorption, Jejunum metabolism, Perfusion methods, Pharmaceutical Preparations metabolism
- Abstract
Purpose: The aims of the study are to develop and evaluate an in vitro rat intestine segmental perfusion model for the prediction of the oral fraction absorbed of compounds and to assess the ability of the model to study intestinal metabolism., Methods: The system consisted of a perfusion cell with a rat intestinal segment and three perfusion circulations (donor, receiver, and rinsing circulation). Lucifer yellow (LY) was applied as internal standard together with test compounds in the donor circulation. To validate the model, the permeability of eight noncongeneric passively absorbed drugs was determined. Intestinal N-demethylation of verapamil into norverapamil was followed in the donor and receiver circulations by high-performance liquid chromatography analysis., Results: The in vitro model allowed ranking of the tested compounds according to their in vivo absorption potential. The Spearman's correlation coefficient between the oral fraction absorbed in humans and the ratio of permeation coefficient of test compound to the permeation coefficient of LY within the same experiment was 0.98 (P < 0.01). Moreover, intestinal N-demethylation of verapamil, its permeation, and the permeation of its metabolite norverapamil could be assessed in parallel., Conclusions: Up to six permeation kinetics can be obtained per rat, and the method has shown to be a valuable tool to estimate human oral absorption.
- Published
- 2006
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21. Functional expression of sinusoidal drug transporters in primary human and rat hepatocytes.
- Author
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Jigorel E, Le Vee M, Boursier-Neyret C, Bertrand M, and Fardel O
- Subjects
- Adult, Animals, Calcium Channel Blockers pharmacology, Cells, Cultured, Gene Expression Regulation, Hepatocytes drug effects, Humans, Male, Membrane Transport Proteins genetics, Probenecid pharmacology, RNA, Messenger metabolism, Rats, Rats, Sprague-Dawley, Sodium pharmacology, Verapamil pharmacology, Hepatocytes metabolism, Membrane Transport Proteins metabolism
- Abstract
Primary hepatocyte cultures are considered as a useful in vitro system for pharmacological/toxicological studies. Although expression of drug-metabolizing enzymes and canalicular drug transporters has been well documented in this cellular model, less information is available about sinusoidal drug transporter activities. This has led us to investigate functional expression of the major sinusoidal transporters in primary human and rat hepatocytes. Using radiolabeled substrates and chemical transporter inhibitors, activities of organic cation transporter 1, organic anion-transporting polypeptides, organic anion transporter 2, and Na(+)-taurocholate cotransporter were detected in cultured human and rat hepatocytes. In parallel, mRNA expression of these transporters was demonstrated using reverse transcriptase-quantitative polymerase chain reaction assays. Functional expression of sinusoidal transport proteins markedly decreased with time in primary rat hepatocyte cultures; by contrast, it remained relatively constant in primary human hepatocytes all along the culture, illustrating the fact that liver-specific functions, including drug-detoxifying pathways, are usually better preserved in cultured human hepatocytes than in their rodent counterparts. Primary hepatocytes, especially human hepatocytes, thus exhibit a pattern of sinusoidal transporter expression close to that found in vivo, highlighting the interest of hepatocyte cultures for drug detoxification studies.
- Published
- 2005
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22. Localisation of drug permeability along the rat small intestine, using markers of the paracellular, transcellular and some transporter routes.
- Author
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Lacombe O, Woodley J, Solleux C, Delbos JM, Boursier-Neyret C, and Houin G
- Subjects
- Animals, Biological Transport physiology, Biomarkers analysis, In Vitro Techniques, Intestinal Absorption physiology, Intestinal Mucosa cytology, Intestine, Small chemistry, Pharmaceutical Preparations analysis, Rats, Staining and Labeling methods, Cell Membrane Permeability, Intestinal Mucosa metabolism, Intestine, Small cytology, Intestine, Small metabolism, Pharmaceutical Preparations metabolism
- Abstract
The small intestine is the major site of drug absorption. Some reports in the literature have evoked the concept of "absorption windows" in the small intestine: are there specific regions where drug absorption is significantly higher than others? To investigate this question, we used an everted gut sac method to study the permeability of drugs and markers every 3-4cm down the entire small intestine in rat. These markers were chosen to be representative of the mechanisms by which drugs cross the small intestinal mucosa: paracellular and transcellular passive diffusion, via influx transporters, and a drug (digoxin) that is effluxed from cells by P-glycoprotein (P-gp). The passive diffusion and influx transporter markers gave similar profiles with a plateau of permeability along the jejunum, and with the exception of L-Dopa, lower permeability in the ileum. Digoxin showed a linear decrease in the profile from the proximal jejunum to the ileum. Permeability in the duodenum was two to three times lower than the jejunum for all compounds. There were no narrow specific regions of high permeability and so the concept of discrete "absorption windows" along the small intestine as suggested from some pharmacokinetic studies may be related to other effects such as pH and/or solubility.
- Published
- 2004
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23. Production and characterization of polyclonal anti-S 20499 antibodies: influence of the hapten structure on stereospecificity.
- Author
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Got PA, Guillaumet G, Boursier-Neyret C, and Scherrmann JM
- Subjects
- Animals, Antibodies immunology, Chromatography, High Pressure Liquid, Cross Reactions, Magnetic Resonance Spectroscopy, Rabbits, Spectrophotometry, Infrared, Stereoisomerism, Anti-Anxiety Agents immunology, Antibodies chemistry, Antibody Formation, Haptens chemistry, Spiro Compounds immunology
- Abstract
Immunoassays were studied as an alternative to HPLC methods for the stereoselective determination of a chiral drug, S 20499, a new anxiolytic compound that is chemically related to buspirone. The production of highly stereospecific polyclonal antibodies was sought following the construction of appropriately optimized hapten-protein conjugates. This process involved the selection of the structure and the length of the spacer arm used to couple S 20499 to the carrier protein as well as deciding on the location of the coupling site with respect to the chiral center. Two haptens were prepared: one a derivative resembling the original structure of S 20499, with the effective addition of a carboxylic acid group, and a second with the effective addition of a butanoic acid moiety that is supposed to favor stereorecognition. Six stereospecific polyclonal antisera were obtained in rabbits with two groups of antibody families defined in terms of specificity. Both approaches gave high levels of stereospecificity (cross-reactivity towards the optical antipode of S 20499 ranged from 4.1% to < 0.1%). Although it did not decrease the mean apparent affinity constant, the longer spacer improved antibody specificity by decreasing cross-reactions towards dealkylated S 20499 derivatives. Hence, the addition of a four carbon atom bridge should be a valuable tool for increasing antibody stereospecificity with no drawbacks in terms of specificity and affinity. It was also shown that long immunization periods appear to have no effect on the stereospecificity of the antibodies obtained.
- Published
- 1997
- Full Text
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