Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
ISSN: 1754-6834

hal-01592860
http://hal.upmc.fr/hal-01592860
http://hal.upmc.fr/hal-01592860/document
http://hal.upmc.fr/hal-01592860/file/s13068-017-0897-7.pdf

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 Elsevier
Résumé : International audience
The mycotoxin enniatin B (EnnB) is predominantly produced by species of the Fusarium genera, and often found in grain. The cytotoxic effect of EnnB has been suggested to be related to its ability to form ionophores in cell membranes. The present study examines the effects of EnnB on cell death, differentiation, proliferation and pro-inflammatory responses in the murine monocyte-macrophage cell line RAW 264.7. Exposure to EnnB for 24 h caused an accumulation of cells in the G0/G1-phase with a corresponding decrease in cyclin D1. This cell cycle-arrest was possibly also linked to the reduced cellular ability to capture and internalize receptors as illustrated by the lipid marker ganglioside GM1. EnnB also increased the number of apoptotic, early apoptotic and necrotic cells, as well as cells with elongated spindle-like morphology. The Neutral Red assay indicated that EnnB induced lysosomal damage; supported by transmission electron microscopy (TEM) showing accumulation of lipids inside the lysosomes forming lamellar structures/myelin bodies. Enhanced levels of activated caspase-1 were observed after EnnB exposure and the caspase-1 specific inhibitor ZYVAD-FMK reduced EnnB-induced apoptosis. Moreover, EnnB increased the release of interleukin-1 beta (IL-1β) in cells primed with lipopolysaccharide (LPS), and this response was reduced by both ZYVAD-FMK and the cathepsin B inhibitor CA-074Me. In conclusion, EnnB was found to induce cell cycle arrest, cell death and inflammation. Caspase-1 appeared to be involved in the apoptosis and release of IL-1β and possibly activation of the inflammasome through lysosomal damage and leakage of cathepsin B.
ISSN: 0041-008X

inserm-00871698
http://www.hal.inserm.fr/inserm-00871698
DOI : 10.1016/j.taap.2012.03.014
PUBMED : 22483798