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International audience; The input into the QIVIVE and Physiologically-Based kinetic and dynamic models of drug metabolising enzymes performance and their inter-individual differences significantly improve the modelling performance, supporting the development and integration of alternative approaches to animal testing. Bayesian meta-analyses allow generating and integrating statistical distributions with human in vitro metabolism data for quantitative in vitro-in vivo extrapolation. Such data are lacking on glutathione-S-transferases (GSTs). This paper reports for the first time results on the human variability of GST activities in healthy individuals, their tissue localisation and the frequencies of their major polymorphic variants by means of extensive literature search, data collection, data base creation and meta-analysis. A limited number of papers focussed on in vivo GST inter-individual differences in humans. Ex-vivo total GST activity without discriminating amongst isozymes is generally reported, resulting in a high inter-individual variability. The highest levels of cytosolic GSTs in humans are measured in the kidney, liver, adrenal glands and blood. The frequencies of GST polymorphisms for cytosolic isozymes in populations of different geographical ancestry were also presented. Bayesian meta-analyses to derive GST-related uncertainty factors provided uncertain estimates, due to the limited database. Considering the relevance of GST activities and their pivotal role in cellular adaptive response mechanisms to chemical stressors, further studies are needed to identify GST probe substrates for specific isozymes and quantify inter-individual differences.

Highlights • Chlorpromazine, an FDA-approved drug, inhibits clathrin-mediated endocytosis • CPZ acts as an antiviral against SARS-CoV-1 and MERS-CoV • We evidenced antiviral activity of CPZ against SARS-CoV-2 in monkey and human cells • Because of CPZ high distribution in lungs, CPZ IC50 may translate in clinical routine • CPZ brain distribution could be of high interest for neurological forms of COVID-19, Introduction Urgent action is needed to fight the ongoing COVID-19 pandemic by reducing the number of infected people along with the infection contagiousness and severity. Chlorpromazine (CPZ), the prototype of typical antipsychotics from the phenothiazine group, is known to inhibit clathrin-mediated endocytosis and acts as an antiviral, in particular against SARS-CoV-1 and MERS-CoV. The aim of this in vitro study was to test CPZ against a SARS-CoV-2 isolate in monkey and human cells. Material and methods Monkey VeroE6 cells and human alveolar basal epithelial A549-ACE2 cells were infected with SARS-CoV-2 in presence of different concentrations of CPZ. Supernatants were harvested at day 2 and analysed by RT-qPCR for the presence of SARS-CoV-2 RNA. Cell viability was assessed on non-infected cells. Results We evidenced an antiviral activity of CPZ against SARS-CoV-2 in monkey VeroE6 cells with an IC50 of 8.2 µM, a CC50 of 13.5µM and a SI of 1.65. In human A549-ACE2 cells, CPZ was also associated with an anti-SARS-CoV-2 activity, with an IC50 of 11.3 µM, a CC50 of 23.1 µM and a SI of 2.04. Discussion Even though the measured SI are low, such IC50 measured in vitro may translate to CPZ dosage used in clinical routine because of CPZ high biodistribution in lungs and in saliva. Also, CPZ brain distribution could be of high interest for treating or preventing the neurological and psychiatric forms of COVID-19. Conclusions These preclinical findings support clinical investigation of the repurposing of CPZ, a largely used drug with mild side effects, in COVID-19 treatment.

International audience; Despite the high incidence of inner ear disorders, there are still no dedicated medications on the market. Drugs are currently administered by the intratympanic route, the safest way to maximize drug concentration in the inner ear. Nevertheless, therapeutic doses are ensured for only a few minutes/hours using drug solutions or suspensions. The passage through the middle ear barrier strongly depends on drug physicochemical characteristics. For the past 15 years, drug encapsulation into nanocarriers has been developed to overcome this drawback. Nanocarriers are well known to sustain drug release and protect it from degradation. In this review, in vivo studies are detailed concerning nanocarrier biodistribution, their pathway mechanisms in the inner ear and the resulting drug pharmacokinetics. Key parameters influencing nanocarrier biodistribution are identified and discussed: nanocarrier size, concentration, surface composition and shape. Recent advanced strategies that combine nanocarriers with hydrogels, specific tissue targeting or modification of the round window permeability (cell-penetrating peptide, magnetic delivery) are explored. Most of the nanocarriers appear to be safe for the inner ear and provide a significant efficacy over classic formulations in animal models. However, many challenges remain to be overcome for future clinical applications.

International audience; The 2016 Zika virus (ZIKV) outbreak in the Americas has been characterized by an increased association frequency of fetal neuropathological abnormalities. To have a comprehensive and accurate knowledge of key elements of the clinically observed neurologic dysfunctions in Zika-infected babies, ZIKV transmission from mother to fetus needs to be deeply studied. Thus, it is important to determine the role of both virus-targeted cells and tissues within the mother-fetus interface. Cellular tropism and mechanisms of ZIKV transmission from mother to the fetus during early pregnancy still remain unknown on many aspects. To improve the characterization of the maternal-fetal ZIKV transmission, we have set up an ex vivo model using an organ culture approach with a light-invasive sampling from the first trimester of pregnancy samples. Thus, here we provide evidence that circulating epidemic ZIKV strains from Latin America widely target and destroy reproductive tissues, including the decidua basalis, fetal placenta, and umbilical cord. In addition, we show that ZIKV is able to differentially replicate in a large range of both maternal and fetal cells, including decidual fibroblasts and macrophages, fetal trophoblast and Hofbauer cells, as well as umbilical cord mesenchymal stem cells. This primary and broad ZIKV cellular tropism and the resulting abundant cytopathic-induced tissue effects during the first trimester of pregnancy show the upstream path of clinically observed congenital damages.

FOLFIRINOX regimen is commonly used in colorectal and more recently pancreatic cancer. However, FOLFIRINOX induces significant and dose-limiting toxic effects leading to empirical dose reduction and sometimes treatment discontinuation. Model-based FOLFIRINOX regimen optimization might help improving patients’ outcome. As a first step, the current review aims at bringing together all published population pharmacokinetics models for FOLFIRINOX anticancer drugs. A literature search was conducted in the PubMed database from inception to February 2018, using the following terms: population pharmacokinetic(s), irinotecan, oxaliplatin, fluorouracil, FOLFIRI, FOLFOX, FOLFIRINOX. Only articles displaying nonlinear mixed effect models were included. Study description, pharmacokinetic parameter values and influential covariates are reported. For each model, the typical pharmacokinetic profile was simulated for the standard FOLFIRINOX protocol. The FOLFIRINOX compounds have been studied only separately so far. A total of six articles were retained for 5-fluorouracil, 6 for oxaliplatin and 5 for irinotecan (also including metabolites). Either one- or two-compartment models have been described for 5-fluorouracil, while two- or three-compartment models were reported for oxaliplatin and irinotecan pharmacokinetics. Non-linear elimination was sometimes reported for 5-fluorouracil. Sex and body size were found as influential covariates for all molecules in some publications. Despite some differences in model structures and parameter values, the simulated profiles and subsequent exposure were consistent between studies. The current review allows for a global understanding of FOLFIRINOX pharmacokinetics, and will provide a basis for further development of pharmacokinetics–pharmacodynamics–toxicity models for model-driven FOLFIRINOX protocol optimization to reach the best benefit-to-risk ratio.

Dendrimers are nanosized, arborescent polymers of which size and structure are perfectly controlled. This is one reason why they are widely used for biomedical purposes. Previously, we showed that a phosphorus-based dendrimer capped with anionic azabisphosphonate groups (so-called ABP dendrimer) has immuno-modulatory and anti-inflammatory properties towards human immune cells in vitro. Thereafter, we have shown that the ABP dendrimer has a promising therapeutic efficacy to treat models of chronic inflammatory disorders. On the way to clinical translation, the biodistribution and the safety of this drug-candidate has to be thoroughly assessed. In this article, we present preliminary non-clinical data regarding biodistribution, hematological safety, genotoxicity, maximal tolerated doses, and early cardiac safety of the ABP dendrimer. One of the genotoxicity assays reveals a potential mutagen effect of the item at a concentration above 200 &micro, M, i.e., up to 100 times the active dose in vitro on human immune cells. However, as the results obtained for all the other assays show that the ABP dendrimer has promising biodistribution and safety profiles, there is no red flag raised to hamper the regulatory pre-clinical development of the ABP dendrimer.

International audience; All of the small number of studies conducted during the second half of last century to investigate the pharmacokinetics of polymyxins in animals used microbiological methods to quantify the compounds in biological fluids. Those methods generally lacked the accuracy and precision required for such investigations and, in the case of studies involving administration of colistin methanesulfonate (CMS), ongoing conversion to colistin during microbiological incubation of collected samples artifactually elevated the measured concentration of colistin. The pharmacokinetic studies reviewed in this chapter involved use of more accurate, precise and specific methods for the measurement of the relevant compounds in biological matrices. The studies have been conducted in a number of pre-clinical animal species following administration via various routes (e.g. intravenous, intrapulmonary), and have provided important insights into not only the global pharmacokinetics as viewed from plasma but also the tissue distribution and handling by key organs particularly the kidneys.

International audience; In the context of increasing liver diseases, no contrast agent is currently available in Europe and the United States to directly assess the liver function. Only neolactosylated human serum albumin is being clinically used in Asia. In order to perform preclinical studies in the context of liver diseases, we conceived a fluorescent lactosylated albumin for the quantification of liver functional cells (l-Cyal). Precise characterization was achieved in order to determine the amounts of lactose and Cyanine 5 (Cy5) coupled to the albumin. In addition, potential aggregation was characterized by asymmetrical flow field-flow fractionation hyphenated to multi-angle light scattering (AF4-MALS). The optimal functionalized albumin exhibited a mass greater than 87 kDa which corresponds to the addition of 34 lactose moieties per protein and 1-2 Cy5 labels. Also, no significant formation of aggregates could be identified due to the modification of the native albumin. In healthy mice, the accumulation of l-Cyal in the liver and its selectivity for hepatocyte cells were shown by optical imaging and flow cytometry. Administration of l-Cyal to mice bearing liver metastases showed a reduced signal in the liver related to a decrease in the number of hepatocytes. The l-Cyal bioimaging contrast agent could be particularly useful for assessing the state of liver related diseases.

International audience; Intranasal drug delivery is emerging as a reliable and promising pathway to deliver a wide range of therapeutic agents including small and large molecules, peptides and proteins, genes to the central nervous system for the treatment of brain diseases such as Alzheimer's disease, Parkinson's disease, depression, migraine, schizophrenia, and glioma. This presents noninvasive entry into the brain via direct nose-to-brain and/or indirect nose-to-blood-to-brain routes. Several nanocarrier-based strategies have been developed to transport therapeutic agents to the brain including nanoparticles, liposomes, and exosomes following intranasal delivery. However, the multiple barriers in nose-to-brain route - including rapid mucociliary clearance in the nasal cavity, enzyme degradation, and the blood-brain barrier (BBB) - pose serious challenges to brain-targeted drug delivery. Hence, very limited translation from the laboratory to the clinic has been achieved. The present review highlights the surface modification of nanocarriers with different strategies devoted to facilitate nose-to-brain delivery: prolonging retention time in the nasal cavity, improving penetration ability, and promoting brain targeting with ligands. Additionally, in vitro blood-brain barrier models, influencing an efficient study on intranasal delivery of therapeutics into the brain through indirect nose-to-blood-to-brain pathway, is discussed.

International audience; At the dawn of the renaissance of bacteriophage therapy, the full acceptation of bacteriophages as anti-bacterial agents requires the determination of their basic pharmacokinetic parameters. Such data, known for all conventional drugs used in human and veterinary medicine, allow optimizing dose regimens, efficacy, and help to limit toxicity. Here, we describe basic methods to experimentally obtain pharmacokinetic data and give also examples of data calculation to determine key parameters related to the biodistribution and elimination of bacteriophages in vivo.

SUMMARYHigh-throughput sequencing technologies now allow for rapid cost-effective surveys of multiple pathogens in many host species including rodents, but it is currently unclear if the organ chosen for screening influences the number and identity of bacteria detected. We used 16S rRNA amplicon sequencing to identify bacterial pathogens in the heart, liver, lungs, kidneys and spleen of 13 water voles (Arvicola terrestris) collected in Franche-Comté, France. We asked if bacterial pathogen assemblages within organs are similar and if all five organs are necessary to detect all of the bacteria present in an individual animal. We identified 24 bacteria representing 17 genera; average bacterial richness for each organ ranged from 1·5 ± 0·4 (mean ± standard error) to 2·5 ± 0·4 bacteria/organ and did not differ significantly between organs. The average bacterial richness when organ assemblages were pooled within animals was 4·7 ± 0·6 bacteria/animal; Operational Taxonomic Unit accumulation analysis indicates that all five organs are required to obtain this. Organ type influences bacterial assemblage composition in a systematic way (PERMANOVA, 999 permutations, pseudo-F4,51 = 1·37, P = 0·001). Our results demonstrate that the number of organs sampled influences the ability to detect bacterial pathogens, which can inform sampling decisions in public health and wildlife ecology.

International audience; Current preclinical dosimetric models often fail to take account of the complex nature of absorbed dose distribution typical of in vitro clonogenic experiments in targeted radionuclide therapy. For this reason, clonogenic survival is often expressed as a function of added activity rather than the absorbed dose delivered to cells/cell nuclei. We designed a multi-cellular dosimetry model that takes into account the realistic distributions of cells in the Petri dish, for the establishment of survival curves as a function of the absorbed dose. General-purpose software tools were used for the generation of realistic, randomised 3D cell culture geometries based on experimentally determined parameters (cell size, cell density, cluster density, average cluster size, cell cumulated activity). A mixture of Monte Carlo and analytical approaches was implemented in order to achieve as accurate as possible results while reducing calculation time. The model was here applied to clonogenic survival experiments carried out to compare the efficacy of Betalutin®, a novel 177Lu-labelled antibody radionuclide conjugate for the treatment of non-Hodgkin lymphoma, to that of 177Lu-labelled CD20-specific (rituximab) and non-specific antibodies (Erbitux) on lymphocyte B cells. The 3D cellular model developed allowed a better understanding of the radiative and non-radiative processes associated with cellular death. Our approach is generic and can also be applied to other radiopharmaceuticals and cell distributions.

Peptides have gained renewed interest as candidate therapeutics. However, to bring them to a broader clinical use, challenges such as the rational optimization of their pharmacological properties remain. Peptide scanning techniques offer a systematic framework to gain information on the functional role of individual amino acids of a peptide. Due to progress in mastering new chemical synthesis routes targeting amino acid backbone, they are currently diversified. Structure-activity relationship (SAR) analyses such as alanine- or enantioneric- scanning can now be supplemented by N-substitution, lactam cyclisation- or aza-amino scanning procedures addressing not only SAR considerations but also the peptide pharmacological properties.This review highlights the different scanning techniques currently available and illustrates how they can impact drug discovery.Progress in peptide scanning techniques opens new perspectives for peptide drug development. It comes with the promise of a paradigm change in peptide drug design in which peptide drugs will be closer to the parent peptides. However, scanning still remains assimilable to a trial and error strategy that could benefit from being combined with specific in silico approaches that start reaching maturity.

The detection of tumours in an early phase of tumour development in combination with the knowledge of expression of tumour markers such as epidermal growth factor receptor (EGFR) is an important prerequisite for clinical decisions. In this study we applied the anti-EGFR nanobody (99m)Tc-D10 for visualizing small tumour lesions with volumes below 100 mm(3) by targeting EGFR in orthotopic human mammary MDA-MB-468 and MDA-MB-231 and subcutaneous human epidermoid A431 carcinoma mouse models. Use of nanobody (99m)Tc-D10 of a size as small as 15.5 kDa enables detection of tumours by single photon emission computed tomography (SPECT) imaging already 45 min post intravenous administration with high tumour uptake (>3% ID/g) in small MDA-MB-468 and A431 tumours, with tumour volumes of 52.5 mm(3) ± 21.2 and 26.6 mm(3) ± 16.7, respectively. Fast blood clearance with a serum half-life of 4.9 min resulted in high in vivo contrast and ex vivo tumour to blood and tissue ratios. In contrast, no accumulation of (99m)Tc-D10 in MDA-MB-231 tumours characterized by a very low expression of EGFR was observed. Here we present specific and high contrast in vivo visualization of small human tumours overexpressing EGFR by preclinical multi-pinhole SPECT shortly after administration of anti-EGFR nanobody (99m)Tc-D10. Open-Access Publikationsfunds 2016 peerReviewed

International audience; The LIM-homeodomain transcription factor Tailup/Islet1 (Tup) is a key component of cardiogenesis in Drosophila and vertebrates. We report here an additional major role for Drosophila Tup in specifying dorsal muscles. Tup is expressed in the four dorsal muscle progenitors (PCs) and tup-null embryos display a severely disorganized dorsal musculature, including a transformation of the dorsal DA2 into dorsolateral DA3 muscle. This transformation is reciprocal to the DA3 to DA2 transformation observed in collier (col) mutants. The DA2 PC, which gives rise to the DA2 muscle and to an adult muscle precursor, is selected from a cluster of myoblasts transiently expressing both Tinman (Tin) and Col. The activation of tup by Tin in the DA2 PC is required to repress col transcription and establish DA2 identity. The transient, partial overlap between Tin and Col expression provides a window of opportunity to distinguish between DA2 and DA3 muscle identities. The function of Tup in the DA2 PC illustrates how single cell precision can be reached in cell specification when temporal dynamics are combined with positional information. The contributions of Tin, Tup and Col to patterning Drosophila dorsal muscles bring novel parallels with chordate pharyngeal muscle development.

International audience; Dyes like CR are able to inhibit the aggregation of Aβ fibrils. Thus, a screening of a series of dyes including ABBB (1) was performed. Its main component 2 tested in an in vitro assay (i.e., ThT assay) showed good potency at inhibiting fibrils association. Congeners 4-9 have been designed and synthesized as inhibitors of Aβ aggregation. A number of these newly synthesized compounds have been found to be active in the ThT assay with IC(50) of 1-57.4 μM. The most potent compound of this series, 4k, showed micromolar activity in this test. Another potent derivative 4q (IC(50) = 5.6 μM) rapidly crossed the blood-brain barrier, achieving whole brain concentrations higher than in plasma. So 4q could be developed to find novel potent antiaggregating βA agents useful in Alzheimer disease as well as other neurological diseases characterized by deposits of amyloid aggregates.

10, 5 figures, 3 tables, 1 suppl figure and 1 suppl table; International audience; Industrial pollution due to heavy metals such as mercury is a major concern for the environment and public health. Mercury, in particular methylmercury (MeHg), primarily affects brain development and neuronal activity, resulting in neurotoxic effects. Because chemokines can modulate brain functions and are involved in neuroinflammatory and neurodegenerative diseases, we tested the possibility that the neurotoxic effect of MeHg may interfere with the chemokine CCL2. We have used an original protocol in young mice using a MeHg-contaminated fish-based diet for 3 months relevant to human MeHg contamination. We observed that MeHg induced in the mice cortex a decrease in CCL2 concentrations, neuronal cell death, and microglial activation. Knock-out (KO) CCL2 mice fed with a vegetal control food already presented a decrease in cortical neuronal cell density in comparison with wild-type animals under similar diet conditions, suggesting that the presence of CCL2 is required for normal neuronal survival. Moreover, KO CCL2 mice showed a pronounced neuronal cell death in response to MeHg. Using in vitro experiments on pure rat cortical neurons in culture, we observed by blockade of the CCL2/CCR2 neurotransmission an increased neuronal cell death in response to MeHg neurotoxicity. Furthermore, we showed that sod genes are upregulated in brain of wild-type mice fed with MeHg in contrast to KO CCL2 mice and that CCL2 can blunt in vitro the decrease in glutathione levels induced by MeHg. These original findings demonstrate that CCL2 may act as a neuroprotective alarm system in brain deficits due to MeHg intoxication.

Purpose To assess the systematic errors in liver methylene fraction (LMF) resulting from fat–fat interference effects with dual- and triple-echo gradient-recalled-echo Dual/Triple GRE) sequences and to test the robustness of these sequences after iron overloading. Materials and Methods Forty type-2 diabetic patients underwent LMF measurement by 3.0T 1H magnetic resonance spectroscopy (corrected for T1 and T2 decays) as the reference standard and liver fat fraction (%Fat) measurement by four Dual/Triple GRE sequences with 20° and 60° flip angle (α), corrected for T1 recovery. The same four sequences were repeated in eight patients after ferumoxide injection. Corrections for systematic errors were determined from the linear regressions (spectroscopy LMF values over Dual/Triple GRE %Fat values). Robustness was tested using Wilcoxon's signed-rank test. Results Fat–fat interference effects produced a ∼10% relative systematic error and T2* decay produced a 1.9%–4.2% absolute systematic error in LMF. When comparing before and after ferumoxide, dual-echo imaging with α = 20° and α = 60°, even when corrected, showed absolute differences of 7.23% [2.81%–10.25%] (P = 0.0117) and 5.65% [1.89%–8.216.8%] (P = 0.0117), respectively; compared to only 1.17% [0.08%–2.83%] (P = 0.0251) and 1.15% [0.37%–2.73%] (P = 0.2626) with triple-echo imaging and α = 20° and α = 60°, respectively. Conclusion Triple-echo imaging with α = 60° corrected for both T1 recovery and fat–fat interference effects is robust after superparamagnetic iron oxide (SPIO) administration and can reliably quantify LMF. J. Magn. Reson. Imaging 2011;33:119–127. © 2010 Wiley-Liss, Inc.

This study investigates the effect of various dietary saturated fatty acid (SFA) profiles on plasma lipid parameters and tissue fatty acid composition in rats. The experiment was designed to monitor polyunsaturated fatty acids (PUFA) levels, while examining different amounts and types of SFA. Four isocaloric diets were prepared, containing 10-11 mol% of fatty acids (FA) as linoleic acid (LNA) and 2.5 mol% as α-linolenic acid (ALA), leading to an identical and well-balanced LNA/ALA ratio. The initial rapeseed oil/corn oil mixture providing ALA and LNA was enriched with olive oil to prepare the olive oil diet. The butterfat diet was supplemented with butterfat, containing short-chain SFA (C4:0-C10:0, 17 mol% of FA), lauric acid (C12:0, 3.2 mol%), myristic acid (C14:0, 10.5 mol%) and palmitic acid (C16:0, 14.5 mol%). The saturates diet was supplemented with trilaurin, trimyristin and tripalmitin to obtain the same level of lauric, myristic and palmitic acids as the butterfat diet, without the short-chain SFA. The trimyristin diet was enriched with trimyristin only. The results showed that the butterfat diet contributed to specific effects, compared to the olive oil diet and the saturates and trimyristin diets: a decrease in plasma total, LDL- and HDL-cholesterol, higher tissue storage of ALA and LNA, and a higher level of (n-3) highly unsaturated fatty acids in some tissues. This study supports the hypothesis that in diets with identical well-balanced LNA/ALA ratios, short chain SFA may decrease circulating cholesterol and increase tissue polyunsaturated fatty acid content in the rat.

This study was supported in part by the program of intellectual property management from the Canadian Institutes of Health Research, Ottawa, and by PulmoScience Inc., Montreal, Canada.; International audience; UNLABELLED: No test currently exists for molecular imaging of pulmonary arterial hypertension (PAH). Adrenomedullin is a vasodilator peptide predominantly cleared by pulmonary endothelial receptors. We developed a linear adrenomedullin derivative radiolabeled with (99m)Tc ((99m)Tc-AM-L) for imaging of pulmonary circulation and tested its capacity to detect anomalies of pulmonary circulation caused by PAH. METHODS: PAH was induced by monocrotaline in rats and compared with controls. After 5 wk, (99m)Tc-AM-L was injected intravenously. Plasma kinetics were measured, lung activity was determined in vivo after 30 min using a nuclear camera, and lung activity was determined ex vivo in explanted lungs. Expression of adrenomedullin receptors was measured in lung homogenates. RESULTS: The plasma levels of (99m)Tc-AM-L significantly increased in PAH by approximately 2-fold. Uptake by the lungs was homogeneous but greatly reduced in PAH by about 70%. In vivo retention was 14% +/- 1% (mean +/- SD) of the injected dose in controls and 4% +/- 1% in PAH (P < 0.0001). A similar reduction was measured ex vivo (6.0 +/- 1.6 percentage injected dose per gram [%ID/g] vs. 0.95 +/- 0.21 %ID/g, P < 0.0001). The expression of the heterodimeric component of the adrenomedullin receptor, receptor activity modifying protein 2, was also greatly reduced in PAH lungs (P < 0.001). Interestingly, right ventricular uptake of (99m)Tc-AM-L was increased by PAH (P = 0.02) and correlated with the degree of right ventricular hypertrophy (r = 0.83, P = 0.001). CONCLUSION: Pulmonary uptake of (99m)Tc-AM-L is greatly reduced in monocrotaline-induced PAH. This novel molecular imaging agent may be useful in the diagnosis and follow-up of pulmonary vascular disorders.

International audience; The present study was initiated to gain some information about the tissue distribution of transient receptor potential proteins of C-type (TRPC), a family of voltage-independent cation channels, at the beginning of neurogenesis in the telencephalon of embryonic mice. The mRNAs of all known TRPCs (TRPC1-TRPC7) could be found in the cortex at E13. TRPC1, TRPC3 and TRPC5 were the main isoforms, whereas the mRNAs for TRPC2, TRPC4, TRPC6 and TRPC7 were less abundant. The distribution throughout the cortical wall of TRPC1, TRPC3 and TRPC6 was studied by means of immuno-histochemistry. The data collected pointed to a heterogeneous expression of the channels. Three groups were identified. The first one comprises TRPC1, specifically found in the preplate but only in some post-mitotic neurons. It was mainly observed in a subset of cells distinct from the Cajal-Retzius cells. The second group is composed of TRPC3. It was found in non-neuronal cells and also in dividing (5-bromo-2'-deoxyuridine-positive) cells, indicating that TRPC3 is present in precursor cells. The third group contains TRPC6 detected in neuronal and in dividing non-neuronal cells. Double immunostaining experiments showed that TRPC3-positive cells also express TRPC6. Collectively, this report highlights a specific TRPC expression pattern in the immature cortical wall.

International audience; Although zinc is an essential trace element involved in many physiological functions, toxicological data concerning acute exposure are scarce. The aim of our study was to determine the maximal iterative dose of zinc that can be administrated in rats without any adverse effect. Saline (control group) or zinc gluconate at 1, 2 or 4 mg/kg were intraperitoneally injected in animals daily during 7 days. The tolerance of zinc treatments was evaluated by the observation of clinical symptoms, haematological parameters and biochemistry, in relation to the zinc and copper levels in blood, liver, pancreas and faeces. We found no serious adverse effect within 1 week in rats injected intraperitoneally with 1 or 2 mg/kg/day of zinc gluconate, which tends to indicate that those doses could be useful in future therapeutic research. In contrast, the therapeutic treatment of adult rats with repeated intraperitoneal injections of a 4 mg/kg/day zinc dose should be cancelled, due to the occurrence of clinical adverse effects within a few days, as intraperitoneal local intolerance or major growth underdevelopment.

International audience; Mammalian sialidase Neu4, ubiquitously expressed in human tissues, is located in the lysosomal and mitochondrial lumen and has broad substrate specificity against sialylated glycoconjugates. To investigate whether Neu4 is involved in ganglioside catabolism, we transfected beta-hexosaminidase-deficient neuroglia cells from a Tay-Sachs patient with a Neu4-expressing plasmid and demonstrated the correction of storage due to the clearance of accumulated GM2 ganglioside. To further clarify the biological role of Neu4, we have generated a stable loss-of-function phenotype in cultured HeLa cells and in mice with targeted disruption of the Neu4 gene. The silenced HeLa cells showed reduced activity against gangliosides and had large heterogeneous lysosomes containing lamellar structures. Neu4(-/-) mice were viable, fertile and lacked gross morphological abnormalities, but showed a marked vacuolization and lysosomal storage in lung and spleen cells. Lysosomal storage bodies were also present in cultured macrophages preloaded with gangliosides. Thin-layer chromatography showed increased relative level of GD1a ganglioside and a markedly decreased level of GM1 ganglioside in brain of Neu4(-/-) mice suggesting that Neu4 may be important for desialylation of brain gangliosides and consistent with the in situ hybridization data. Increased levels of cholesterol, ceramide and polyunsaturated fatty acids were also detected in the lungs and spleen of Neu4(-/-) mice by high-resolution NMR spectroscopy. Together, our data suggest that Neu4 is a functional component of the ganglioside-metabolizing system, contributing to the postnatal development of the brain and other vital organs.

This work aimed at building a population pharmacokinetic (PK) model for lamivudine (LMV), stavudine (STV) and zidovudine (ZDV), estimating their inter and intraindividual PK variability and investigating the influence of different covariates. Population PK of LMV, STV and ZDV was separately evaluated from plasma concentrations obtained in 54, 39 and 27 HIV1-infected patients, respectively, enrolled in the COPHAR1-ANRS102 trial. The primary objective of this trial was to study the pharmacokinetics of indinavir (IDV) and nelfinavir (NFV) in treated patients with a sustained virological response. Concentrations of nucleoside analogs (NA) were measured in plasma as a secondary objective. A one-compartment model with first-order elimination was used, with zero-order absorption for LMV and first-order absorption for STV and ZDV. Mean parameters [interpatient variability in coefficient of variation (CV%)] of LMV, STV and ZDV were: oral volume of distribution (V/F) 145 l (52%), 24 l (81%) and 248 l (80%), oral clearance (Cl/F) 32 l/h, 16 l/h (74%) and 124 l/h (51%), respectively. For LMV, absorption duration (T a ) was 1.46 h (64%). For STV and ZDV, k a was 0.46 h−1 and 2.9 h−1, respectively. We found a systematic effect of combination with NFV vs. IDV. We found that intrapatient variability was greater than interpatient variability (except for STV) and greater than 55% for the three drugs. This trial enabled the estimation of the population PK parameters of three NA in patients with a sustained virological response, and the median curves could be used as references for concentration-controlled strategies. We observed, as for the protease inhibitors, a great variability of PK parameters.

Periodic paralysis, cardiac arrhythmia and bone features are the hallmark of Andersen's syndrome (AS), a rare disorder caused by mutations in the KCNJ2 gene that encodes for the inward rectifier K(+)-channel Kir2.1. Rest following strenuous physical activity, carbohydrate ingestion, emotional stress and exposure to cold are the precipitating triggers. Most of the mutations act in a dominant-negative fashion, either through a trafficking dysfunction or through Kir2.1-phosphatidyl inositol bisphosphate binding defect. We have identified two families that were diagnosed with periodic paralysis and cardiac abnormalities, but only discrete development features. The proband in one of the two families reported having his symptoms occurring twice within the day following corticosteroids ingestion, and alleviated after stopping the corticosteroid treatment. Electromyographic evaluations pointed out to a typical hypokalemic periodic paralysis pattern. Molecular screening of the KCNJ2 gene identified two mutations leading to C54F and T305P substitutions in the Kir2.1 protein. Functional expression in mammalian cells revealed a loss-of-function of the mutated channels and a dominant-negative effect when both mutants and wild-type channels are present in the same cell. However, channel trafficking and assembly are not affected. Substitutions at these residues may interfere with phosphatidyl inositol bisphosphate binding to Kir2.1 channels. Sensitivity of our patients to multiple corticosteroid administrations shows that care must be taken in the use of such treatments in AS patients. Taken together, our data suggest the inclusion of the KCNJ2 gene in the molecular screening of patients with periodic paralysis, even when the classical AS dysmorphic features are not present.

Introduction RNA interference is efficient in in vitro studies, and appears as a therapeutic tool of major clinical interest. Nevertheless, the clinical utilisation of siRNAs is restrained by the poor availability of biodistribution data on this new class of pharmaceutics. This study aimed at defining the biodistribution and pharmacokinetics properties of an siRNA directed to the Casein Kinase-2 beta (CK2β) subunit, a potential target in cancer therapy. Methods Four CK2β siRNAs were chemically modified on each extremity of sense or anti-sense strand and radioiodinated. The biodistribution of each entity was analysed in glioblastoma-bearing mice using nuclear imaging and compared to a control GFP siRNA. Results The labelling process was associated with preservation of interference activity, except when applied to the 5 ' antisense terminus. Radioactivity was predominantly observed in organs of the excretory system after intravenous administration: liver, kidneys and bladder. Tumor/Contralateral muscle ratio showed significant differences depending on the labelling site. Activity associated with CK2β 5 ' s was quite constant over 2hours, while CK2β 3 ' as activity decreased by 40% in tumor. Finally, synchrotron X-ray analysis showed that CK2β 3 ' s is more abundant in tumor than in liver, brain or muscle, and uniformly distributed between intra- and extracellular compartments. Conclusions In this study, we highlighted the large influence of siRNAs radiolabelling position on their biodistribution and pharmacokinetic profiles, and proposed a systematic approach for the imaging of all siRNAs of clinical interest.

In the cuttlefish, Sepia officinalis, the ovary appears to be one of the main sources of regulatory peptides involved in the successive steps of egg-laying. Following the identification of the SepCRP-1, which is a peptide extracted from ovary and involved in egg capsule secretion, investigations were focused on the identification of related peptides. Seven related-Sepia Capsule Releasing Peptides (R-SepCRPs) were identified by means of mass spectrometry and characterized using MS/MS spectra and/or Edman degradation. Finally, primary structures were verified by the comparison of MS/MS spectra from endogenic and synthetic peptides. This new ovarian peptide family exhibits a conserved SLXKD tag involved in the biological activity. LC-MS/MS screening clearly demonstrates that R-SepCRPs are restricted to the female genital tract. Expressed during vitellogenesis, they are released by vitellogenic follicles and full-grown oocytes (FGO) in the genital coelom. Biological activities suggest that R-SepCRPs would be responsible for the storage of FGO before mating and would take part in the mechanical secretion of egg capsule products, as previously described for SepCRP-1.

International audience; Rat quiescin/sulphydryl oxidase (rQSOX) introduces disulphide bridges into peptides and proteins with the reduction of molecular oxygen to hydrogen peroxide. Its occurrence has been previously highlighted in a wide range of organs by reverse transcription-polymerase chain reaction (RT-PCR) and Northern blot analyses, methods that have provided information concerning its expression in whole organs but that do not reveal the cell types expressing this enzyme. In this report, in addition to RT-PCR and Western blot experiments, the cell-specific localization of rQSOX has been investigated in a wide range of male and female adult rat tissues by using in situ hybridization and immunohistochemistry. Labelling was detected in most organs and systems including the immune, endocrine and reproductive systems, the respiratory, digestive and urinary tracts and the skin. No labelling was observed in the heart, blood vessel endothelium, liver or smooth and skeletal muscles. rQSOX expression was mainly localized in epithelial cells specialized in secretion, strengthening the hypothesis that QSOX enzymes play an important role in the mechanism of secretion, notably in the folding of secreted proteins. The intracellular patterns of immunolabelling indicate that the protein usually follows the secretory pathway, which is in accordance with its secreted nature and its presumed involvement in the elaboration of the extracellular matrix. In seminiferous tubules, where a high level of expression was noticed, QSOX might play an important physiological role in sperm function and serve as a marker for the diagnosis of male infertility.

International audience; With the aim of finding important mediators of muscle atrophy, we cloned SMHS1, a novel gene that was found to be upregulated in rat soleus muscle atrophied by restriction of activity. The SMHS1 amino acid sequence shares 65% similarity with RTP801-which is a cellular stress response protein regulated by HIF-1-but SMHS1 expression was demonstrated to be independent of HIF-1. SMHS1 was found to be mainly expressed in skeletal muscle, and comparisons of its expression in atrophied versus hypertrophied muscles and in oxidative versus glycolytic muscles suggested that SMHS1 contributes to the muscle energy metabolism phenotypes.

International audience; Scorpion stings represent a medical problem in numerous countries. The scorpion Androctonus australis hector produces three alpha toxins (Aah I to III), which are responsible for most of the lethality in mammals. These toxins act on sodium channel and do not cross-react immunologically. We used RIA and ELISA to measure the concentrations of these three toxins in plasma, urine and different organs after i.v. and s.c. injections of water extracts of venoms in rabbits or mice. In both animals, the toxins rapidly appeared in plasma after s.c. injection as it was previously described for the whole venom. However, the toxins disappeared from the blood more quickly than did other main components of the venom. Thus, serotherapy must be initiated immediately to prevent the toxin from reaching its target. We also detected the toxins in urine, kidneys, heart and lungs, but not in the brain. However, the concentration of Aah II was always lower than that of Aah I. Analysis of five samples of venom collected in different areas of southern Tunisia showed that a large polymorphism exists for the three toxins. This is yet another difficulty for serotherapy as there is no cross-antigenicity between them.

International audience; Contrast-enhanced radiotherapy is an innovative treatment that combines the selective accumulation of heavy elements in tumors with stereotactic irradiations using medium energy X-rays. The radiation dose enhancement depends on the absolute amount of iodine reached in the tumor and its time course. Quantitative, postinfusion iodine biodistribution and associated brain perfusion parameters were studied in human brain metastasis as key parameters for treatment feasibility and quality. Twelve patients received an intravenous bolus of iodinated contrast agent (CA) (40 mL, 4 mL/s), followed by a steady-state infusion (160 mL, 0.5 mL/s) to ensure stable intratumoral amounts of iodine during the treatment. Absolute iodine concentrations and quantitative perfusion maps were derived from 40 multislice dynamic computed tomography (CT) images of the brain. The postinfusion mean intratumoral iodine concentration (over 30 minutes) reached 1.94 ± 0.12 mg/mL. Reasonable correlations were obtained between these concentrations and the permeability surface area product and the cerebral blood volume. To our knowledge, this is the first quantitative study of CA biodistribution versus time in brain metastasis. The study shows that suitable and stable amounts of iodine can be reached for contrast-enhanced radiotherapy. Moreover, the associated perfusion measurements provide useful information for the patient recruitment and management processes.

International audience; The cDNA sequence and expression profile of a novel human gene, encoding a new member of the immunoglobulin superfamily, is reported. The gene is localized in the pericentromeric region of human X chromosome between the markers DXS1213 and DXS1194. Abundant expression of transcripts was detected in several human fetal tissues, whereas among adult tissues lung and placenta express highest levels of Z39Ig mRNA.

International audience; We have recently discovered a new class of potassium channels with two pore-forming domains and four membrane-spanning domains. When heterologously expressed, these channels produce time- and voltage-independent currents that classify them as background or leak channels. TWIK (for tandem of P domains in a weak inwardly rectifying K+ channel) was the first member of this family to be cloned. Here, we describe the genomic organization of TWIK in the mouse. The coding sequence as well as the untranslated sequences are contained in three exons. The twik gene (or KCNK1) has been mapped to chromosome 8, consistent with its localization to 1q42-43 in human. The twik gene is expressed in virtually all mouse tissues. It is most abundantly expressed in brain and moderately in other organs such as kidney. The level of expression is increased in brain and kidney from neonate to adult animals, but the TWIK message is also detected during embryogenesis, as early as day 7 post conception.

International audience; Contrast-enhanced radiotherapy is an innovative treatment that combines the selective accumulation of heavy elements in tumors with stereotactic irradiations using medium energy X-rays. The radiation dose enhancement depends on the absolute amount of iodine reached in the tumor and its time course. Quantitative, postinfusion iodine biodistribution and associated brain perfusion parameters were studied in human brain metastasis as key parameters for treatment feasibility and quality. Twelve patients received an intravenous bolus of iodinated contrast agent (CA) (40 mL, 4 mL/s), followed by a steady-state infusion (160 mL, 0.5 mL/s) to ensure stable intratumoral amounts of iodine during the treatment. Absolute iodine concentrations and quantitative perfusion maps were derived from 40 multislice dynamic computed tomography (CT) images of the brain. The postinfusion mean intratumoral iodine concentration (over 30 minutes) reached 1.94 ± 0.12 mg/mL. Reasonable correlations were obtained between these concentrations and the permeability surface area product and the cerebral blood volume. To our knowledge, this is the first quantitative study of CA biodistribution versus time in brain metastasis. The study shows that suitable and stable amounts of iodine can be reached for contrast-enhanced radiotherapy. Moreover, the associated perfusion measurements provide useful information for the patient recruitment and management processes.

International audience; Calcium/calmodulin-dependent protein kinase II (CaMKII) is a key kinase that transduces Ca²⁺ signals into downstream effects acting on a range of cellular processes in nervous system and muscular tissues. In insects, different CaMKII isoforms have been reported in Drosophila melanogaster, Apis florae, Bombus terrestris, and Bombus impatiens but little is known on the organization and tissue-specific expression of these isoforms with the exception of Drosophila. The present study reports the cloning of five CaMKII splice variants issued from a single gene and their tissue-specific expression in the cockroach Periplaneta americana. Each CaMKII isoform shared 82-90% identity with Drosophila CaMKII isoforms and accordingly were named PaCaMKII-A, PaCaMKII-B,PaCaMKII-C,PaCaMKII-D, and PaCaMKII-E. PaCaMKII-A and PaCaMKII-D isoforms are ubiquitously expressed in all tissues, but some such as PaCaMKII-B andPaCaMKII-C are preferentially expressed in the nerve cord and muscle. In addition, using single-cell reverse transcriptase-polymerase chain reaction (RT-PCR), we found a tissue-specific expression of PaCaMKII-E in the dorsal unpaired median neurons. Alternative splicing of PaCaMKII transcripts is likely a common mechanism in insects to control the pattern of isoform expression in the different tissues.

International audience; Nicorandil is an original vasodilatator used to control angina by decreasing cardiac preload and afterload. Since 1997, many reports of single or multiple nicorandil-induced ulcerations have been published. To date, eight cases of nicorandil-induced fistula into adjacent organs have been described. The pathogeneses of nicorandil-induced ulceration and fistula into adjacent organs are not yet elucidated. The two main hepatic biotransformation pathways of nicorandil are denitration and reduction of the alkyl chain leading to nicotinamide and niconitic acid which merge into the endogenous pool of nicotinamide adenine dinucleotide/phosphate. This merging which is known as saturable, may contribute to a slow and abnormal distribution of nicotinamide and nicotinic acid out of the endogenous pool. Under these special conditions, providing these two molecules in situ, nicotinic acid associated with nicotinamide may ulcerate rather recent or maintained trauma. Ulcers and fistulae induced by nicorandil heal after withdrawal. Surgical intervention is unnecessary and inappropriate as it is ineffective and exacerbates morbidity. All practitioners should be correctly informed about these serious but preventable nicorandil side effects, which mostly occur in the elderly and fragile population. In the absence of corrective measures, withdrawal of this original and active drug should be considered.

International audience; The kinetics of in vivo regulation of mitochondrial respiration by ADP was studied in rat heart, slow-twitch skeletal muscle (soleus) and fast-twitch skeletal muscle (gastrocnemius, plantaris, quadriceps and tibialis anterior) by means of saponin-skinned fibres. Mitochondrial respiratory parameters were determined in the absence and presence of creatine (20 mM), and the effect of proteolytic enzymes (trypsin, chymotrypsin or elastase) on these parameters was investigated in detail. The results of these experiments confirm the observation of Veksler et al. [Veksler, V.I., Kuznetsov, A. V., Anflous, K., Mateo, P., van Deursen, J., Wieringa, B. & Ventura-Clapier, R. (1995) J. Biol. Chem. 270, 19921-19929], who studied muscle fibres from normal and transgenic mice, that the kinetics of respiration regulation in muscle cells is tissue specific. We found that in rat cardiac and soleus muscle fibres the apparent K(m) for respiration regulation was 300-400 microM and decreased to 50-80 microM in the presence of creatine. In contrast, in skinned fibres from gastrocnemius, plantaris, tibialis anterior and quadriceps muscles, this value was initially very low, 10-20 microM, i.e. the same as that is in isolated muscle mitochondria, and the effect of creatine was not observable under these experimental conditions. Treatment of the fibres with trypsin, chymotrypsin or elastase (0.125 micrograms/ml) for 15 min decreased the apparent K(m) for ADP in cardiac and soleus muscle fibres to 40-98 microM without significant alteration of Vmax or the intactness of outer mitochondrial membrane, as assessed by the cytochrome c test. In fibres from gastrocnemius, trypsin increased the apparent K(m) for ADP transiently. The effects of trypsin and chymotrypsin were studied in detail and found to be concentration dependent and time dependent. The effects were characterised by saturation phenomenon with respect to the proteolytic enzyme concentration, saturation being observed above 1 microM enzyme. These results are taken to show that in cardiac and slow-twitch skeletal muscle, the permeability of the outer mitochondrial membrane to adenine nucleotides is low and controlled by a cytoplasmic protein that is sensitive to trypsin and chymotrypsin. This protein may participate in feedback signal transduction by a mechanism of vectorial-ligand conduction. This protein factor is not expressed in fast-twitch skeletal muscle, in which cellular mechanism of regulation of respiration is probably very different from that of slow-twitch muscles.

International audience; Quantitative in situ hybridization revealed that following the induction of hippocampal long-term potentiation (LTP) in the dentate gyrus of freely moving rats, specific increases in the expression of the NR2B subunit of the N-methyl-D-aspartate (NMDA) receptor and mGluR1c, a short splice variant of the metabotropic glutamate receptors that are linked intracellularly to phospholipase C (PLC) and protein kinase C (PKC), were seen in the postsynaptic dentate granule cells. There were no changes in the expression of NR2A; NR2C and NR2D NMDA receptor subunits; or mGluR1a, mGluR1b, mGluR5a, and mGluR5b PLC-associated metabotropic receptors. The elevations in NR2B and mGluR1c mRNA were delayed, occurring days after LTP induction. NR2B expression was enhanced significantly by 48 hr after LTP but was starting to decrease toward basal levels by 96 hr. The transient increase in the expression of NR2B mirrored the increase in the expression of PKC-sensitive isoforms of the NR1 subunits of the NMDA receptor we observed previously (Thomas et al. 1994a). The increase in mGluR1c expression was more persistent, showing a significant increase 96 hr after LTP. This study demonstrates that not only are there changes in the expression of individual glutamate receptor subunits but the increases in their expression occur days after the induction of LTP and may reflect so-called late-onset genes that may be important for the maintenance of LTP.

Uptake1 and uptake2 transporters are involved in the extracellular clearance of biogenic amine neurotransmitters at synaptic clefts. We looked for them at the blood–brain barrier (BBB) and blood–retina barriers (BRB), where they could be involved in regulating the neurotransmitter concentration and modulate/terminate receptor-mediated effects within the neurovascular unit (NVU). Uptake2 (Oct1-3/Slc22a1-3, Pmat/Slc29a4) and Mate1/Slc47a1 transporters are also involved in the transport of xenobiotics. We used in situ carotid perfusion of prototypic substrates like [3H]-1-methyl-4-phenylpyridinium ([3H]-MPP+), [3H]-histamine, [3H]-serotonin, and [3H]-dopamine, changes in ionic composition and genetic deletion of Oct1-3 carriers to detect uptake1 and uptake2 at the BBB and BRB. We showed that uptake1 and uptake2 are involved in the transport of [3H]-dopamine and [3H]-MPP+ at the blood luminal BRB, but not at the BBB. These functional studies, together with quantitative RT-PCR and confocal imaging, suggest that the mouse BBB lacks uptake1 (Net/Slc6a2, Dat/Slc6a3, Sert/Slc6a4), uptake2, and Mate1 on both the luminal and abluminal sides. However, we found evidence for functional Net and Oct1 transporters at the luminal BRB. These heterogeneous transport properties of the brain and retina NVUs suggest that the BBB helps protect the brain against biogenic amine neurotransmitters in the plasma while the BRB has more of a metabolic/endocrine role.

International audience; The aim of this study was to develop new Lipiodol formulations with increased viscosities to augment Lipiodol embolic effect and optimize efficiency of radiolabeled Lipiodol in hepatocarcinoma treatments. New Lipiodol formulations consist of Lipiodol mixtures with different stearic acid concentrations (0.8%, 1.3%, and 1.8%). These formulations were fully characterized in vitro (viscosity, rheologic profiles) and labeled with 99mTc. Their viscosities at 20°C are 54, 60, and 67cP respectively, versus 45cP for Lipiodol ultra-fluide. Second, their biodistribution profiles were studied in vivo, at 24 and 72 hours, in hepatoma-bearing rats, and compared to control group (99mTc-Lipiodol). Biodistribution at 24 hours show a Gaussian tumor uptake profile with a maximum obtained with 1.3% stearic acid, and a tumor uptake superior to control group (+67%) (p

International audience; Receptor-interacting protein 140 (RIP140) is a negative transcriptional coregulator of nuclear receptors such as estrogen, retinoic acid or glucocorticoid receptors. Recruitment of RIP140 results in an inhibition of target gene expression through different repressive domains interacting with histone deacetylases or C-terminal binding proteins. In this study, we analyzed the role of RIP140 activity in memory processes using RIP140-deficient transgenic mice. Although the RIP140 protein was clearly expressed in the brain (cortical and hippocampus areas), the morphological examination of RIP140(-/-) mouse brain failed to show grossly observable alterations. Using male 2-month-old RIP140(-/-) , RIP140(+/-) or RIP140(+/+) mice, we did not observe any significant differences in the open-field test, rotarod test and in terms of spontaneous alternation in the Y-maze. By contrast, RIP140(-/-) mice showed long-term memory deficits, with an absence of decrease in escape latencies when animals were tested using a fixed platform position procedure in the water maze and in the passive avoidance test. Noteworthy, RIP140(-/-) mice showed decreased swimming speed, suggesting swimming alterations that may in part account for the marked alterations measured in the water maze. Moreover, RIP140(+/-) and RIP140(-/-) mice showed a significant increase in immobility time in the forced swimming test as compared with wild-type animals. These observations showed that RIP140 gene depletion results in learning and memory deficits as well as stress response, bringing to light a major role for this transcriptional coregulator in the neurophysiological developmental mechanisms underlying cognitive functions.

International audience; Receptor-interacting protein 140 (RIP140) is a negative transcriptional coregulator of nuclear receptors such as estrogen, retinoic acid or glucocorticoid receptors. Recruitment of RIP140 results in an inhibition of target gene expression through different repressive domains interacting with histone deacetylases or C-terminal binding proteins. In this study, we analyzed the role of RIP140 activity in memory processes using RIP140-deficient transgenic mice. Although the RIP140 protein was clearly expressed in the brain (cortical and hippocampus areas), the morphological examination of RIP140(-/-) mouse brain failed to show grossly observable alterations. Using male 2-month-old RIP140(-/-) , RIP140(+/-) or RIP140(+/+) mice, we did not observe any significant differences in the open-field test, rotarod test and in terms of spontaneous alternation in the Y-maze. By contrast, RIP140(-/-) mice showed long-term memory deficits, with an absence of decrease in escape latencies when animals were tested using a fixed platform position procedure in the water maze and in the passive avoidance test. Noteworthy, RIP140(-/-) mice showed decreased swimming speed, suggesting swimming alterations that may in part account for the marked alterations measured in the water maze. Moreover, RIP140(+/-) and RIP140(-/-) mice showed a significant increase in immobility time in the forced swimming test as compared with wild-type animals. These observations showed that RIP140 gene depletion results in learning and memory deficits as well as stress response, bringing to light a major role for this transcriptional coregulator in the neurophysiological developmental mechanisms underlying cognitive functions.

31 pages; International audience; We analyzed the cellular distribution of the pancreatic inflammatory protein lithostathine and its receptor EXTL3 in the brain of the lemurian primate Microcebus murinus which develops amyloid deposits along with aging. In adult animals (2-4.5 years old), lithostathine and EXTL3 immunoreactivities were largely distributed in the whole brain, and more intensively in almost all cortical layers and hippocampal formation. Lithostathine was observed in the perikarya and neurites of cortical neurons but also in glial cells in the border of the ventricle and the corpus callosum. In healthy aged animals (8-13 years old), highest densities of lithostathine-containing cells were observed, mainly in occipital and parietal cortex. In aged animals with Aβ deposits, the increase in lithostathine immunoreactivity was lower as compared with aged animals. Noteworthy, lithostathine-immunopositive cells did almost never colocalize with Aβ plaques. In conclusion, lithostathine immunoreactivity in adult Microcebus murinus appeared ubiquitous and particularly in visual, sensorial, and cognitive brain areas. Immunoreactivity increased with aging and appeared markedly affected in neuropathological conditions. Its possible neuroprotection or neurodegeneration role in Alzheimer pathology deserves therefore to be investigated.

10, 5 figures, 3 tables, 1 suppl figure and 1 suppl table; International audience; Industrial pollution due to heavy metals such as mercury is a major concern for the environment and public health. Mercury, in particular methylmercury (MeHg), primarily affects brain development and neuronal activity, resulting in neurotoxic effects. Because chemokines can modulate brain functions and are involved in neuroinflammatory and neurodegenerative diseases, we tested the possibility that the neurotoxic effect of MeHg may interfere with the chemokine CCL2. We have used an original protocol in young mice using a MeHg-contaminated fish-based diet for 3 months relevant to human MeHg contamination. We observed that MeHg induced in the mice cortex a decrease in CCL2 concentrations, neuronal cell death, and microglial activation. Knock-out (KO) CCL2 mice fed with a vegetal control food already presented a decrease in cortical neuronal cell density in comparison with wild-type animals under similar diet conditions, suggesting that the presence of CCL2 is required for normal neuronal survival. Moreover, KO CCL2 mice showed a pronounced neuronal cell death in response to MeHg. Using in vitro experiments on pure rat cortical neurons in culture, we observed by blockade of the CCL2/CCR2 neurotransmission an increased neuronal cell death in response to MeHg neurotoxicity. Furthermore, we showed that sod genes are upregulated in brain of wild-type mice fed with MeHg in contrast to KO CCL2 mice and that CCL2 can blunt in vitro the decrease in glutathione levels induced by MeHg. These original findings demonstrate that CCL2 may act as a neuroprotective alarm system in brain deficits due to MeHg intoxication.

Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental disorders with a complex inheritance pattern. While many rare variants in synaptic proteins have been identified in patients with ASD, little is known about their effects at the synapse and their interactions with other genetic variations. Here, following the discovery of two de novo SHANK2 deletions by the Autism Genome Project, we identified a novel 421 kb de novo SHANK2 deletion in a patient with autism. We then sequenced SHANK2 in 455 patients with ASD and 431 controls and integrated these results with those reported by Berkel et al. 2010 (n = 396 patients and n = 659 controls). We observed a significant enrichment of variants affecting conserved amino acids in 29 of 851 (3.4%) patients and in 16 of 1,090 (1.5%) controls (P = 0.004, OR = 2.37, 95% CI = 1.23–4.70). In neuronal cell cultures, the variants identified in patients were associated with a reduced synaptic density at dendrites compared to the variants only detected in controls (P = 0.0013). Interestingly, the three patients with de novo SHANK2 deletions also carried inherited CNVs at 15q11–q13 previously associated with neuropsychiatric disorders. In two cases, the nicotinic receptor CHRNA7 was duplicated and in one case the synaptic translation repressor CYFIP1 was deleted. These results strengthen the role of synaptic gene dysfunction in ASD but also highlight the presence of putative modifier genes, which is in keeping with the “multiple hit model” for ASD. A better knowledge of these genetic interactions will be necessary to understand the complex inheritance pattern of ASD., Author Summary Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental disorders with a complex inheritance pattern. While mutations in several genes have been identified in patients with ASD, little is known about their effects on neuronal function and their interaction with other genetic variations. Using a combination of genetic and functional approaches, we identified novel SHANK2 mutations including a de novo loss of one copy of the SHANK2 gene in a patient with autism and several mutations observed in patients that reduced neuronal cell contacts in vitro. Further genomic analysis of three patients carrying de novo SHANK2 deletions identified additional rare genomic imbalances previously associated with neuropsychiatric disorders. Taken together, these results strengthen the role of synaptic gene dysfunction in ASD but also highlight the presence of putative modifier genes, which is in keeping with the “multiple hit model” for ASD. A better knowledge of these genetic interactions will be necessary to understand the complex inheritance pattern of ASD.

10, 5 figures, 3 tables, 1 suppl figure and 1 suppl table; International audience; Industrial pollution due to heavy metals such as mercury is a major concern for the environment and public health. Mercury, in particular methylmercury (MeHg), primarily affects brain development and neuronal activity, resulting in neurotoxic effects. Because chemokines can modulate brain functions and are involved in neuroinflammatory and neurodegenerative diseases, we tested the possibility that the neurotoxic effect of MeHg may interfere with the chemokine CCL2. We have used an original protocol in young mice using a MeHg-contaminated fish-based diet for 3 months relevant to human MeHg contamination. We observed that MeHg induced in the mice cortex a decrease in CCL2 concentrations, neuronal cell death, and microglial activation. Knock-out (KO) CCL2 mice fed with a vegetal control food already presented a decrease in cortical neuronal cell density in comparison with wild-type animals under similar diet conditions, suggesting that the presence of CCL2 is required for normal neuronal survival. Moreover, KO CCL2 mice showed a pronounced neuronal cell death in response to MeHg. Using in vitro experiments on pure rat cortical neurons in culture, we observed by blockade of the CCL2/CCR2 neurotransmission an increased neuronal cell death in response to MeHg neurotoxicity. Furthermore, we showed that sod genes are upregulated in brain of wild-type mice fed with MeHg in contrast to KO CCL2 mice and that CCL2 can blunt in vitro the decrease in glutathione levels induced by MeHg. These original findings demonstrate that CCL2 may act as a neuroprotective alarm system in brain deficits due to MeHg intoxication.

International audience; Secretoneurin, a 33-34 amino acid neuropeptide derived from the proteolytic processing of the secretogranin-II precursor protein, is reasonably well conserved in evolution. Goldfish secretoneurin shares >75% similarity overall with other vertebrate secretoneurin sequences. The secretoneurin peptide has numerous functions that include neuroinflammation, neurotransmitter release, and neuroendocrine regulation. A detailed description of the central distribution of secretoneurin immunoreactivity is only known for the rat. Using our polyclonal antibody against the central, conserved core of the secretoneurin peptide we studied the distribution of secretoneurin-like immunoreactivity in the goldfish brain. Secretoneurin immunoreactivity was found in the olfactory bulb, entopeduncular nucleus, preoptic nucleus, lateral part of the lateral tuberal nucleus, posterior periventricular nucleus, nucleus of the posterior recess, the nucleus of the saccus vasculosus, and nucleus isthmi. Secretoneurin-immunoreactive fibers were found in the dorsal part of the dorsal telencephalon, ventral and lateral parts of the ventral telencephalon, periventricular preoptic nucleus, pituitary, and the ventrocaudal aspect of the nucleus of the lateral recess. The most conspicuous secretoneurin immunoreactivity was found in the magnocellular and parvocellular cells of the preoptic nucleus that project to the pituitary. Double-labeling studies indicated coexpression with isotocin, the fish homolog of mammalian oxytocin. Clear colabeling for secretoneurin and isotocin in fibers terminating in the neurointermediate lobe suggests that secretoneurin maybe coreleased with isotocin. Previous work indicates that secretoneurin stimulates the release of luteinizing hormone from the goldfish anterior pituitary. Our findings further support a reproductive role for secretoneurin and related peptides, given the importance of oxytocin family peptides in reproductive behavior in vertebrates.

In mice and other mammals, spermatogenesis is maintained by spermatogonial stem cells (SSCs), a cell population belonging to undifferentiated type A spermatogonia. In the accepted model of SSC self-renewal, Asingle (As) spermatogonia are the stem cells, whereas paired (Apaired (Apr)) and chained (Aaligned (Aal)) undifferentiated spermatogonia are committed to differentiation. This model has been recently challenged by evidence that As and chained (Apr and Aal), undifferentiated spermatogonia are heterogeneous in terms of gene expression and function. The expression profile of several markers, such as GFRA1 (the GDNF co-receptor), is heterogeneous among As, Apr and Aal spermatogonia. In this study, we have analysed and quantified the distribution of GFRA1-expressing cells within the different stages of the seminiferous epithelial cycle. We show that in all stages, GFRA1+ chained spermatogonia (Apr to Aal) are more numerous than GFRA1+ As spermatogonia. Numbers of chained GFRA1+ spermatogonia are sharply reduced in stages VII–VIII when Aal differentiate into A1 spermatogonia. GFRA1 expression is regulated by GDNF and in cultures of isolated seminiferous tubules, we found that GDNF expression and secretion by Sertoli cells is stage-dependent, being maximal in stages II–VI and decreasing thereafter. Using qRT-PCR analysis, we found that GDNF regulates the expression of genes such asTex14, Sohlh1andKit(c-Kit) known to be involved in spermatogonial differentiation. Expression ofKitwas upregulated by GDNF in a stage-specific manner. Our data indicate that GDNF, besides its crucial role in the self-renewal of stem cells also functions in the differentiation of chained undifferentiated spermatogonia.

International audience; Docosahexaenoic acid (DHA), upon incorporation into tumor tissue, has the potential to sensitize tumors to the effects of chemotherapy or radiation therapy. Although DHA has usually been supplied to tumor tissue in the diet, appropriate dietary conditions required to obtain optimal tumor levels have not been established. Hence, we studied mammary tumor tissue responses in rats fed various durations and doses of DHA. Rats fed a palm oil enriched diet (diet 0) were switched to diets providing either 0.8 g DHA/day (diet 1) or 1.5 g DHA/day (diet 2). Tumor tissue fatty acid composition was analysed at baseline (diet 0), at weeks 1, 4 and 9 during diet 1 and at week 4 during diet 2. Dietary DHA supplementation differentially increased DHA within phospholipids (PL) and triacylglycerol (TAG) fractions in tumors. DHA level equilibrated between 2 and 4 weeks in PL while DHA increase was more progressive in TAG and did not reach a steady state. A higher dose of DHA further increased DHA content in tumor PL and TAG (P = 0.018 and P < 0.001, respectively). DHA concentration in plasma PL was positively correlated with DHA in tumor PL (r = 0.72; P = 0.0003) and TAG (r = 0.64; P = 0.003). We conclude that dietary DHA supplementation enhances tumor content of DHA in a time- and dose-dependent manner, and that the DHA level in plasma PL could be used as a proxy for tumor DHA. These findings have implications for dietary DHA supplementations in cancer patients.

Background: To date, breast cancer epidemiologic studies have relied on blood or tissue specimens sampled at the time of diagnosis or a few years prior to assess lifetime exposure to polychlorinated biphenyls (PCB). In this study, we evaluated whether such PCB measurements are indicative of early-life levels by reconstructing lifetime toxicokinetic profiles for women included in the CECILE case–control study, using a physiologically based pharmacokinetic (PBPK) model. Methods: We simulated lifetime toxicokinetic profiles of PCB-153 for 2,134 French women by incorporating information on body weight history, height, pregnancies, and breast-feeding in the PBPK model. Oral dose was calculated by considering measured blood PCB-153 and the temporal trend of environmental contamination. Area under the concentration versus time curve (AUC) for each decade of life and maximum blood concentration (Cmax) were compiled and compared with measured levels, using Pearson partial correlation analyses adjusting for age at diagnosis. Results: When considering all individuals, simulated AUCs correlated with measured PCBs, with coefficients ranging from 0.735 to 0.981. The weakest correlations were obtained with AUCs for the first decades of life. Stratified analyses suggested that breast-feeding reduces the reliability of late-life blood levels in representing lifetime exposure. Conclusion: Results of this study suggest that PCB levels measured at the time of diagnosis do not fully represent early-life exposures. Impact: PBPK-derived estimates of early-life levels circumvent the limitations of current approaches in assessing PCB lifetime exposure and may be used to address hypothesized windows of breast vulnerability (e.g., puberty) in this population. Cancer Epidemiol Biomarkers Prev; 20(2); 281–6. ©2010 AACR.