Laboratoire Of Toxicologie Biologique

Paris, France

Laboratoire Of Toxicologie Biologique

Paris, France
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Panchal M.,Laboratoire Of Neuropathologie Escourolle | Panchal M.,French Institute of Health and Medical Research | Gaudin M.,University of Paris Descartes | Lazar A.N.,Laboratoire Of Neuropathologie Escourolle | And 14 more authors.
Neurobiology of Disease | Year: 2014

The senile plaque is a hallmark lesion of Alzheimer disease (AD). We compared, without a priori, the lipidome of the senile plaques and of the adjacent plaque-free neuropil. The analysis by liquid chromatography coupled with electrospray ionization mass spectrometry revealed that laser microdissected senile plaques were enriched in saturated ceramides Cer(d18:1/18:0) and Cer(d18:1/20:0) by 33 and 78% respectively with respect to the surrounding neuropil. This accumulation of ceramides was not explained by their affinity for Aβ deposits: no interaction between ceramide-liposomes and Aβ fibrils was observed in vitro by surface plasmon resonance and fluorescent ceramide-liposomes showed no affinity for the senile plaques in AD brain tissue. Accumulation of ceramides could be, at least partially, the result of a local production by acid and neutral sphingomyelinases that we found to be present in the corona of the senile plaques. © 2014 Elsevier Inc.

Martin D.,French National Institute for Agricultural Research | Charpilienne A.,French National Institute for Agricultural Research | Parent A.,CNRS Natural Product Chemistry Institute | Boussac A.,CNRS Institute of Pharmacology and Structural Biology | And 3 more authors.
FASEB Journal | Year: 2013

During rotavirus infection, replication and packaging of the viral genome occur in viral factories, termed viroplasms. The viral nonstructural protein NSP5 is a major building block of viroplasms; it recruits the viral polymerase VP1, the core protein VP2, and the ATPase NSP2 inside the viroplasm to form the viral replication complex. Here we report that NSP5 is a unique viral metalloprotein that coordinates a [2Fe-2S] iron-sulfur cluster as demonstrated by the metal and labile sulfide contents, UV-visible light absorption, and electron paramagnetic resonance. Point mutations in NSP5 allowed us to identify C171 and C174, arranged in a CX2C motif, as essential residues for cluster coordination. When coexpressed with NSP2, an NSP5 mutant devoid of the iron-sulfur cluster still forms viroplasm-like structures. The cluster is therefore neither involved in the interaction with NSP2 nor in the formation of viroplasm-like structures and thus presumably in viroplasm formation. Finally, we show using microscale thermophoresis that the iron-sulfur cluster modulates the affinity of NSP5 for single-stranded RNA. Because the cluster is near the binding sites of both the polymerase VP1 and the ATPase NSP2, we anticipate that this cluster is crucial for NSP5 functions, in either packaging or replication of the viral genome. © FASEB.

Chtchigrovsky M.,CNRS Natural Product Chemistry Institute | Eloy L.,CNRS Natural Product Chemistry Institute | Jullien H.,CNRS Natural Product Chemistry Institute | Saker L.,University of Paris Descartes | And 6 more authors.
Journal of Medicinal Chemistry | Year: 2013

A series of bimetallic [(NHC)PtX2]2(diamine) complexes have been prepared as a new chemotype for potential anticancer agents. These complexes display an uncommon set of structural features as far as they combine two bifunctional, trans-configured platinum centers. They display cytotoxic activities in the micromolar range on many cancerous cell lines and do not cross-react with cisplatin in A2780/DDP cell lines. They bind slowly to double-stranded DNAs, giving monoadducts as the major products. Pathways for cellular toxicity have been investigated for both mono- and bimetallic trans-(NHC)PtX2(amine) complexes. It has been highlighted that, unlike cisplatin, these complexes do not induce cell cycle arrest. They trigger apoptosis in A2780 cells by a pathway involving translocation of apoptosis-inducing factor and caspase 12 to the nucleus. Moreover, bimetallic complexes may induce necrosis. © 2013 American Chemical Society.

PubMed | CNRS Natural Product Chemistry Institute, French Institute of Health and Medical Research, University of Paris Descartes and Laboratoire Of Toxicologie Biologique
Type: Journal Article | Journal: Bioconjugate chemistry | Year: 2016

G-quadruplex structures (G4) are promising anticancerous targets. A great number of small molecules targeting these structures have already been identified through biophysical methods. In cellulo, some of them are able to target either telomeric DNA and/or some sequences involved in oncogene promotors, both resulting in cancer cell death. However, only a few of them are able to bind to these structures G4 irreversibly. Here we combine within the same molecule the G4-binding agent PDC (pyridodicarboxamide) with a N-heterocyclic carbene-platinum complex NHC-Pt already identified for its antitumor properties. The resulting conjugate platinum complex NHC-Pt-PDC stabilizes strongly G-quadruplex structures in vitro, with affinity slightly affected as compared to PDC. In addition, we show that the new conjugate binds preferentially and irreversibly the quadruplex form of the human telomeric sequence with a profile in a way different from that of NHC-Pt thereby indicating that the platination reaction is oriented by stacking of the PDC moiety onto the G4-structure. In cellulo, NHC-Pt-PDC induces a significant loss of TRF2 from telomeres that is considerably more important than the effect of its two components alone, PDC and NHC-Pt, respectively.

Trocello J.-M.,Center National Of Reference Pour La Maladie Of Wilson | El Balkhi S.,Center National Of Reference Pour La Maladie Of Wilson | El Balkhi S.,Laboratoire Of Toxicologie Biologique | Woimant F.,Center National Of Reference Pour La Maladie Of Wilson | And 4 more authors.
Movement Disorders | Year: 2014

Background: Family screening is a main step for the diagnosis in Wilson disease. This study was undertaken to evaluate the value of relative exchangeable copper for family screening. Methods: Data from family screening were collected from the French National Center of Reference for Wilson disease. Subjects who were first- or second-degree relatives of the index case underwent clinical examination and biological parameters. Results: Of 127 subjects examined, copper abnormalities or low ceruloplasminemia were detected in 21 subjects, corresponding to 5 patients with Wilson disease, 14 heterozygous ATP7B carriers and 2 subjects with no ATP7B mutations. Relative exchangeable copper determination significantly discriminates heterozygous ATP7B carriers and subjects with no ATP7B mutations from WD patients with a cutoff of 15%. Conclusions: Exchangeable copper appears to be a promising tool for family screening in Wilson disease. © 2013 International Parkinson and Movement Disorder Society.

PubMed | Service dHematologie Senior, Laboratoire Of Toxicologie Biologique, French Institute of Health and Medical Research, Service de Biologie Cellulaire AP HP Hopital Saint Louis and University Paris Diderot
Type: Journal Article | Journal: Leukemia | Year: 2015

We recently identified that the MEK/ERK1/2 pathway synergized with retinoic acid (RA) to restore both transcriptional activity and RA-induced differentiation in RA-resistant acute promyelocytic leukemia (APL) cells. To target the MEK/ERK pathway, we identified glycogen synthase kinase-3 (GSK-3) inhibitors including lithium chloride (LiCl) as activators of this pathway in APL cells. Using NB4 (RA-sensitive) and UF-1 (RA-resistant) APL cell lines, we observed that LiCl as well as synthetic GSK-3 inhibitors decreased proliferation, induced apoptosis and restored, in RA-resistant cells, the expression of RA target genes and the RA-induced differentiation. Inhibition of the MEK/ERK1/2 pathway abolished these effects. These results were corroborated in primary APL patient cells and translated in vivo using an APL preclinical mouse model in which LiCl given alone was as efficient as RA in increasing survival of leukemic mice compared with untreated mice. When LiCl was combined with RA, we observed a significant survival advantage compared with mice treated by RA alone. In this work, we demonstrate that LiCl, a well-tolerated agent in humans, has antileukemic activity in APL and that it has the potential to restore RA-induced transcriptional activation and differentiation in RA-resistant APL cells in an MEK/ERK-dependent manner.

Menet M.-C.,University of Paris Descartes | Fonsart J.,University Paris Diderot | Fonsart J.,Laboratoire Of Pharmacologie | Herve F.,University of Paris Descartes | And 4 more authors.
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2010

The consumption of psychostimulant amphetamine-like drugs has increased significantly in recent years. Some MDMA metabolites are probably involved in the neurotoxicity and neurodegeneration caused by prolonged use rather than MDMA itself. We recently developed a method to analyze MDMA and its five main metabolites in rat plasma [7]. We have now fully validated this method to the quantification of these drugs in rat urine. We extracted MDMA and its metabolites with Oasis WCX cartridges, separated them on a Nucleodur C18 analytical column and quantified them by ion-trap mass spectrometry. Linearity was excellent: 12.5-1250ng/mL urine for HMA, HMMA, MDA and MDMA, 25-2500ng/mL for HHMA, and 150-7500ng/mL for HHA (r 2>0.993 for all analytes). The lower limits of quantification were 12.5ng/mL urine for MDMA, MDA, HMA and HMMA, 25ng/mL for HHMA and 150ng/mL for HHA. Reproducibility was good (intra-assay precision=1.7-6.1%; inter-assay precision=0.6-5.7%), as was accuracy (intra-assay deviation=0.1-4.8%; inter-assay deviation=0.7-7.9%). Average recoveries were around 85.0%, except for HHMA (66.2%) and HHA (53.0%) (CV<8.3%). We also checked the stability of stock solutions and the internal standards after freeze-thawing and in the autosampler. Lastly, we measured the MDMA, MDA, HHMA, HHA, HMMA and HMA in urine samples taken over 24h from rats given subcutaneous MDMA. © 2010 Elsevier B.V.

Bourgogne E.,Laboratoire Of Toxicologie Biologique | Bourgogne E.,University of Paris Descartes | Wagner M.,Thionville
Annales de Biologie Clinique | Year: 2015

The quantitative analysis of compounds of clinical interest of low molecular weight (<1000 Da) in biological fluids is currently in most cases performed by liquid chromatography-mass spectrometry (LC-MS). Analysis of these compounds in biological fluids (plasma, urine, saliva, hair...) is a difficult task requiring a sample preparation. Sample preparation is a crucial part of chemical/biological analysis and in a sense is considered the bottleneck of the whole analytical process. The main objectives of sample preparation are the removal of potential interferences, analyte preconcentration, and converting (if needed) the analyte into a more suitable form for detection or separation. Without chromatographic separation, endogenous compounds, co-eluted products may affect a quantitative method in mass spectrometry performance. This work focuses on three distinct parts. First, quantitative bioanalysis will be defined, different matrices and sample preparation techniques currently used in bioanalysis by mass spectrometry of/for small molecules of clinical interest in biological fluids. In a second step the goals of sample preparation will be described. Finally, in a third step, sample preparation strategies will be made either directly ("dilute and shoot") or after precipitation.

PubMed | Laboratoire Of Biochimie, University of Paris Descartes, Laboratoire Of Toxicologie Biologique and Reanimation Medicale Toxicologique
Type: | Journal: Journal of pharmaceutical and biomedical analysis | Year: 2014

A rapid, sensitive and specific method using liquid chromatography coupled to tandem mass spectrometry was developed for the simultaneous quantification of hydroxychloroquine (HCQ) and its three major metabolites in human whole blood. The assay, using a sample volume of 100L, was linear in a dynamic 25-2000ng/mL range (R(2)>0.99) for all four compounds and suitable for the determination of elevated HCQ concentrations up to 20,000ng/mL, after appropriate sample dilution. Inter- and intra-assay precisions were <18.2% and accuracies were between 84% and 113% for any analyte. No matrix effects were observed. The assay was successfully applied to a blood sample obtained from one poisoned patient following a massive HCQ self-ingestion resulting in an estimated concentration of 19,500ng/mL on hospital admission. In this patient, HCQ metabolites were identified and quantified at 1123, 465 and 91ng/mL for monodesethylhydroxychloroquine, desethylchloroquine and bisdesethylchloroquine, respectively. Further investigations are still required to assess the usefulness of the simultaneous measurement of blood concentrations of HCQ and its three active metabolites for monitoring HCQ treatment and managing HCQ poisoning.

PubMed | French Institute of Health and Medical Research and Laboratoire Of Toxicologie Biologique
Type: Journal Article | Journal: PloS one | Year: 2015

It is well known that several metals, such as lead, mercury, cadmium, and vanadium, can mimic the effects of estrogens (metallo-estrogens). Nevertheless, there are only a few studies that have assessed the effects of toxic metals on the female genital tract and, in particular, endometrial tissue. In this context, we measured the concentrations of several trace elements in human endometrial tissue samples from individuals with hyperplasia or adenocarcinoma and in normal tissues. Hyperplasic endometrial tissue has a 4-fold higher concentration of mercury than normal tissue. Mercury can affect both the AhR and ROS signaling pathways. Thus, we investigated the possible toxic effects of mercury by in vitro studies. We found that mercury increases oxidative stress (increased HO1 and NQO1 mRNA levels) and alters the cytoskeleton in the human endometrial Ishikawa cell line and to a lesser extent, in the less-differentiated human endometrial Hec-1b cells. The results might help to explain a potential link between this metal and the occurrence of endometrial hyperplasia.

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