Éditeur(s) : HAL CCSD Kasetsart University
Résumé : http://www.ceropath.org/references/rodent_protocols_book
Technical book
"Protocols for field and laboratory rodent studies" present the best practices for the studies of rodents and rodent-borne pathogens and parasites from the field to the laboratory. It aims at covering the different steps of rodent studies: 1) Trapping, 2) Dissection and preparation of tissue samples for pathogens screening, 3) Identification of species, 4) Isolation of helminths, 5) Preparing rodent specimens for collections. This book gathers accurate recommendations and techniques, based on those generally accepted in the literature and adapted from the experience of the different authors during rodent surveys and laboratory work. Its presentation is designed to work in the fields with a clear and colorful organization of each chapter, with: inserts providing definitions and recommendations, protocols detailed step by step, and an emphasis on illustrations with several photographs. This book is a publication generated by the CERoPath project (Community Ecology of Rodents and their Pathogens in a changing environment, www.ceropath.org) funded by the French Ministry of Research from 2008 to 2011.
http://hal.ird.fr/ird-00714514

ird-00714514
http://hal.ird.fr/ird-00714514
http://hal.ird.fr/ird-00714514/document
IRD : fdi:010056183

Éditeur(s) : HAL CCSD American Society of Tropical Medicine and Hygiene
Résumé : International audience
We investigated infection of rodents and shrews by Leptospira spp. in two localities of Cambodia (Veal Renh, Kaev Seima) and in four types of habitat (forests, non-flooded lands, lowland rain-fed paddy fields, houses) during the wet and the dry seasons. Habitat preference was common, and rodent and shrew species were found only in houses or in rain-fed paddy fields or in forests. Among 649 small mammals trapped belonging to 12 rodent species and 1 shrew species, 71 of 642 animals tested were carriers of Leptospira according to the 16S ribosomal RNA marker used. Rodent infection was higher in low-slope locations, corresponding to rain-fed paddy fields, especially in the rainy season and in Kaev Seima. Rodents (Rattus exulans) and shrews (Suncus murinus) inhabiting households showed significantly low levels of infections, whereas rodents living in and near to forests (shrubby wasteland, orchards) showed high levels of infection.
American Journal of Tropical Medicine and Hygiene

pasteur-00808144
https://hal-riip.archives-ouvertes.fr/pasteur-00808144
DOI : 10.4269/ajtmh.2012.11-0349
PUBMED : 22665613

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
While the effects of deforestation and habitat fragmentation on parasite prevalence or richness are well investigated, host-parasite networks are still understudied despite their importance in understanding the mechanisms of these major disturbances. Because fragmentation may negatively impact species occupancy, abundance and co-occurrence, we predict a link between spatiotemporal changes in habitat and the architecture of host-parasite networks. For this, we used an extensive data set on 16 rodent species and 29 helminth species from seven localities of South-East Asia. We analysed the effects of rapid deforestation on connectance and modularity of helminth-parasite networks. We estimated both the degree of fragmentation and the rate of deforestation through the development of land uses and their changes through the last 20 to 30years in order to take into account the dynamics of habitat fragmentation in our statistical analyses. We found that rapid fragmentation does not affect helminth species richness per se but impacts host-parasite interactions as the rodent-helminth network becomes less connected and more modular. Our results suggest that parasite sharing among host species may become more difficult to maintain with the increase of habitat disturbance.
ISSN: 0021-8790

hal-01355307
https://hal.archives-ouvertes.fr/hal-01355307
DOI : 10.1111/1365-2656.12368
IRD : fdi:010064927

Éditeur(s) : HAL CCSD Humana Press
Résumé : International audience
The sodium-proton exchanger 1 (NHE-1) is a membrane transporter that exchanges Na(+) for H(+) ion across the membrane of eukaryotic cells. It is cooperatively activated by intracellular protons, and this allosteric regulation is modulated by the biophysical properties of the plasma membrane and related lipid environment. Consequently, NHE-1 is a mechanosensitive transporter that responds to osmotic pressure, and changes in membrane composition. The purpose of this study was to develop the relationship between membrane surface tension, and the allosteric balance of a mechanosensitive transporter such as NHE-1. In eukaryotes, the asymmetric composition of membrane leaflets results in a difference in surface tensions that is involved in the creation of a reservoir of intracellular vesicles and membrane buds contributing to buffer mechanical constraints. Therefore, we took this phenomenon into account in this study and developed a set of relations between the mean surface tension, membrane asymmetry, fluid phase endocytosis and the allosteric equilibrium constant of the transporter. We then used the experimental data published on the effects of osmotic pressure and membrane modification on the NHE-1 allosteric constant to fit these equations. We show here that NHE-1 mechanosensitivity is more based on its high sensitivity towards the asymmetry between the bilayer leaflets compared to mean global membrane tension. This compliance to membrane asymmetry is physiologically relevant as with their slower transport rates than ion channels, transporters cannot respond as high pressure-high conductance fast-gating emergency valves.
ISSN: 1085-9195

inserm-00871709
http://www.hal.inserm.fr/inserm-00871709
http://www.hal.inserm.fr/inserm-00871709/document
http://www.hal.inserm.fr/inserm-00871709/file/art_3A10.1007_2Fs12013-012-9340-7.pdf
DOI : 10.1007/s12013-012-9340-7

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
Androgen signaling, via the androgen receptor (AR), is crucial in mediating prostate cancer (PCa) initiation and progression. Identifying new downstream effectors of the androgens/AR pathway will allow a better understanding of these mechanisms and could reveal novel biomarkers and/or therapeutic agents to improve the rate of patient survival. We compared the microRNA expression profiles in androgen-sensitive LNCaP cells stimulated or not with 1 nM R1881 by performing a high-throughput reverse transcriptase-quantitative PCR and found that miR-135a was upregulated. After androgen stimulation, we showed that AR directly activates the transcription of miR-135a2 gene by binding to an androgen response element in the promoter region. Our findings identify miR-135a as a novel effector in androgens/AR signaling. Using xenograft experiments in chick embryos and adult male mice, we showed that miR-135a overexpression decreases in vivo invasion abilities of prostate PC-3 cells. Through in vitro wound-healing migration and invasion assays, we demonstrated that this effect is mediated through downregulating ROCK1 and ROCK2 expression, two genes that we characterized as miR-135a direct target genes. In human surgical samples from prostatectomy, we observed that miR-135a expression was lower in tumoral compared with paired adjacent normal tissues, mainly in tumors classified with a high Gleason score (⩾8). Moreover, miR-135a expression is lower in invasive tumors, showing extraprostatic extension, as compared with intraprostatic localized tumors. In tumor relative to normal glands, we also showed a more frequently higher ROCK1 protein expression determined using a semi-quantitative immunohistochemistry analysis. Therefore, in tumor cells, the lower miR-135a expression could lead to a higher ROCK1 protein expression, which could explain their invasion abilities. The highlighted relationship between miR-135a expression level and the degree of disease aggressiveness suggests that miR-135a may be considered as a prognostic marker in human PCa.Oncogene advance online publication, 28 July 2014; doi:10.1038/onc.2014.222.
ISSN: 0950-9232

hal-01063902
https://hal.archives-ouvertes.fr/hal-01063902
https://hal.archives-ouvertes.fr/hal-01063902/file/Androgen-regulated%20microRNA-135a.pdf
DOI : 10.1038/onc.2014.222
PUBMED : 25065599

Éditeur(s) : HAL CCSD
Résumé : Staphylococcus aureus can cause a wide range of infections in humans and warm-blooded animals. The epithelial surface is the principal site of staphylococcal infection. The goal of this work was to investigate the cytopathic effect of S. aureus and its ability to affect host cell cycle. Cultures of human cervix cancer HeLa and mammary gland bovine MAC-T epithelial cells were used to study in vitro the effects of S. aureus strains from human or ruminant origins. Using microscopic examination, we found that S. aureus induced an enlargement of the host cells and we observed that S. aureus slowed down cell proliferation. Similar effect was observed on both human and bovine cells using the human or the ruminant strains. Microscopic analysis of DAPI-stained cells revealed huge decrease of mitotic indexes in infected HeLa and Mac-T cells, synchronized by Double Thymidine Block. Flow cytometry analysis showed that S. aureus induces G2/M phase delay in synchronous HeLa cells. Western blot analysis revealed that the G2/M phase delay was associated with an accumulation of inactive phosphorylated cyclin-dependent kinase Cdk1/cdc2, a key inducer of mitosis entry, and dephosphorylation of core histone H3, an important component of the epigenetic landscape. Altogether, these results suggest that the delay in G2/M phase transition of the infected epithelial cells may be one of the mechanisms employed by S. aureus to survive and to propagate inside the host. Further investigations are ongoing to fully understand the mechanisms associated to this type of S. aureushost cell interactions.
journées des Microbiologistes de l' INRA 2012
L'Isle sur la Sorgue, France

hal-01209365
https://hal.archives-ouvertes.fr/hal-01209365
PRODINRA : 174569

Éditeur(s) : HAL CCSD Landes Bioscience
Résumé : International audience
In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
Autophagy

hal-00735751
https://hal.archives-ouvertes.fr/hal-00735751
PUBMED : 22966490

Éditeur(s) : HAL CCSD American Society for Microbiology
Résumé : International audience
: We investigated the in vitro effects of four alkyl-galactofuranoside derivatives, i.e. octyl-β-D-galactofuranoside (1), 6-amino-β-D-galactofuranoside (2), 6-N-acetamido-β-D-galactofuranoside (3), and 6-azido-β-D-galactofuranoside (4) on Leishmania donovani. Their mechanism of action was explored using electron paramagnetic resonance spectroscopy (EPR) and nuclear magnetic resonance (NMR), and ultrastructural alterations by transmission electron microscopy (TEM). Compound 1 showed the most promising effects by inhibiting promastigote growth at IC50 8.96 ± 2.5 μM. All compounds exhibit low toxicity towards human macrophages. Compound 1 had a higher selectivity index than the comparative molecule used, i.e. miltefosine (159.7 versus 37.9, respectively). EPR showed that compound 1 significantly reduced membrane fluidity, compared to control promastigotes and to compound 3. The furanose ring was shown to support this effect since the isomer galactopyranose had no effect on parasite membrane fluidity or growth. NMR showed a direct interaction of all compounds (1>2>3>4) with the promastigote membrane, as well as with octyl-galactopyranose and octanol, providing evidence that the n-octyl chain was primarily involved in the anchoring with the parasite membrane, followed by the putative crucial role of furanose ring in the anti-leishmanial activity. A morphologic analysis of compound 1-treated promastigotes by TEM revealed profound alterations on parasite membrane and organelles, but not with compound 3. Quantification of annexinV binding by flow cytometry confirmed that compound 1 induced apoptosis in >90% promastigotes. The effect of compound 1 was also assessed on intra-macrophagic amastigotes, and showed a reduction in amastigote growth associated with an increase of ROS production, thus validating its promising effect.
ISSN: 0066-4804

hal-00941772
https://hal.archives-ouvertes.fr/hal-00941772
PUBMED : 24468785
DOI : 10.1128/AAC.01350-13

Éditeur(s) : HAL CCSD
Résumé : International audience
Background Orodental diseases include several clinically and genetically heterogeneous disorders that can present in isolation or as part of a genetic syndrome. Due to the vast number of genes implicated in these disorders, establishing a molecular diagnosis can be challenging. We aimed to develop a targeted next-generation sequencing (NGS) assay to diagnose mutations and potentially identify novel genes mutated in this group of disorders. Methods We designed an NGS gene panel that targets 585 known and candidate genes in orodental disease. We screened a cohort of 101 unrelated patients without a molecular diagnosis referred to the Reference Centre for Oro-Dental Manifestations of Rare Diseases, Strasbourg, France, for a variety of orodental disorders including isolated and syndromic amelogenesis imperfecta (AI), isolated and syndromic selective tooth agenesis (STHAG), isolated and syndromic dentinogenesis imperfecta, isolated dentin dysplasia, otodental dysplasia and primary failure of tooth eruption. Results We discovered 21 novel pathogenic variants and identified the causative mutation in 39 unrelated patients in known genes (overall diagnostic rate: 39%). Among the largest subcohorts of patients with isolated AI (50 unrelated patients) and isolated STHAG (21 unrelated patients), we had a definitive diagnosis in 14 (27%) and 15 cases (71%), respectively. Surprisingly, COL17A1 mutations accounted for the majority of autosomal-dominant AI cases. Conclusions We have developed a novel targeted NGS assay for the efficient molecular diagnosis of a wide variety of orodental diseases. Furthermore, our panel will contribute to better understanding the contribution of these genes to orodental disease. Trial registration numbers NCT01746121 and NCT02397824
Journal of Medical Genetics

hal-01272929
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01272929
DOI : 10.1136/jmedgenet-2015-103302
PUBMED : 26502894

Éditeur(s) : HAL CCSD
Résumé : International audience
Background: Comparative analysis, which aims at investigating ecological and evolutionary patterns among species, may help at targeting reservoirs of zoonotic diseases particularly in countries presenting high biodiversity. Here, we developed a simple method to target rodent reservoirs using published studies screening microparasite infections. Methods: We compiled surveys of microparasites investigated in rodents trapped in Thailand. The data comprise a total of 17,358 rodents from 18 species that have been investigated for a total of 10 microparasites (viruses, bacteria and protozoans). We used residual variation of microparasite richness controlled for both rodent sample size and pathogens' screening effort to identify major rodent reservoirs and potential risky habitats. Results: Microparasite species richness was positively related to rodent sample size and pathogens' screening effort. The investigation of the residual variations of microparasite species richness showed that several rodent species harboured more pathogens than expected by the regression model. Similarly, higher pathogen richness than expected was observed in rodents living in non-flooded lands, forests and paddy fields. Conclusion: Our results suggest to target some rodent species that are not commonly investigated for pathogen screening or surveillance such as R. andamanensis or B. savilei, and that non-flooded lands and forests should be more taken into caution, whereas much surveys focused on paddy rice fields and households.
Infection Ecology and Epidemiology

ird-00714369
http://hal.ird.fr/ird-00714369
http://hal.ird.fr/ird-00714369v2/document
DOI : 10.3402/iee.v2iO.18637
IRD : fdi:010055557

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Plasma membrane is an early target of polycyclic aromatic hydrocarbons (PAH). We previously showed that the PAH prototype, benzo[a]pyrene (B[a]P), triggers apoptosis via DNA damage-induced p53 activation (genotoxic pathway) and via remodeling of the membrane cholesterol-rich microdomains called lipid rafts, leading to changes in pH homeostasis (non-genotoxic pathway). As omega-3 (n-3) fatty acids can affect membrane composition and function or hamper in vivo PAH genotoxicity, we hypothesized that addition of physiologically relevant levels of polyunsaturated n-3 fatty acids (PUFAs) might interfere with B[a]P-induced toxicity. The effects of two major PUFAs, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), were tested on B[a]P cytotoxicity in the liver epithelial cell line F258. Both PUFAs reduced B[a]P-induced apoptosis. Surprisingly, pre-treatment with DHA increased the formation of reactive B[a]P metabolites, resulting in higher levels of B[a]P-DNA adducts. EPA had no apparent effect on B[a]P metabolism or related DNA damage. EPA and DHA prevented B[a]P-induced apoptotic alkalinization by affecting Na(+)/H(+) exchanger 1 activity. Thus, the inhibitory effects of omega-3 fatty acids on B[a]P-induced apoptosis involve a non-genotoxic pathway associated with plasma membrane remodeling. Our results suggest that dietary omega-3 fatty acids may have marked effects on the biological consequences of PAH exposure.
ISSN: 0009-2797

hal-00950341
https://hal.archives-ouvertes.fr/hal-00950341
https://hal.archives-ouvertes.fr/hal-00950341/document
https://hal.archives-ouvertes.fr/hal-00950341/file/DENDELE_et_al_2013-unmarked.pdf
PUBMED : 24246761

Éditeur(s) : HAL CCSD
Résumé : International audience
Idiopathic pulmonary fibrosis (IPF) is the most frequent chronic idiopathic interstitial pneumonia in adults. The management of rare diseases in France has been organised by a national plan for rare diseases, which endorsed a network of expert centres for rare diseases throughout France. This article is an overview of the executive summary of the French guidelines for the management of IPF, an initiative that emanated from the French National Reference Centre and the Network of Regional Competence Centres for Rare Lung Diseases. This review aims at providing pulmonologists with a document that: 1) combines the current available evidence; 2) reviews practical modalities of diagnosis and management of IPF; and 3) is adapted to everyday medical practice. The French practical guidelines result from the combined efforts of a coordination committee, a writing committee and a multidisciplinary review panel, following recommendations from the Haute Autorité de Santé. All recommendations included in this article received at least 90% agreement by the reviewing panel. Herein, we summarise the main conclusions and practical recommendations of the French guidelines.
Eur Respir Rev

hal-01063982
https://hal.archives-ouvertes.fr/hal-01063982
DOI : 10.1183/09059180.00001814
PUBMED : 24881074