Interaction with surrounding normal epithelial cells influences signalling pathways and behaviour of Src-transformed cells

At the initial stage of carcinogenesis, transformation occurs in a single cell within an epithelial sheet. However, it remains unknown what happens at the boundary between normal and transformed cells. Using Madin-Darby canine kidney (MDCK) cells transformed with temperature-sensitive v-Src, we have examined the interface between normal and Src-transformed epithelial cells. We show that Src-transformed cells are apically extruded when surrounded by normal cells, but not when Src cells alone are cultured, suggesting that apical extrusion occurs in a cell-context-dependent manner. We also observe apical extrusion of Src-transformed cells in the enveloping layer of zebrafish gastrula embryos. When Src-transformed MDCK cells are surrounded by normal MDCK cells, myosin-II and focal adhesion kinase (FAK) are activated in Src cells, which further activate downstream mitogen-activated protein kinase (MAPK). Importantly, activation of these signalling pathways depends on the presence of surrounding normal cells and plays a crucial role in apical extrusion of Src cells. Collectively, these results indicate that interaction with surrounding normal epithelial cells influences the signalling pathways and behaviour of Src-transformed cells

Utilisation de l'homéopathie chez le cheval pour le traitement des maladies digestives, locomotrices et respiratoires

MONTPELLIER-BU Pharmacie (341722105) / SudocSudocFranceF

Ubiquitylation et déubiquitylation au cours de l'endocytose chez Saccharomyces cerevisiae

PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

Itinéraires croisés et relations entre éleveurs et salariés dans les Alpes du Nord

National audienceWe analyse the substitution of family workforce by wage workers in livestock farming systems from the Northern Alps, by crossing their life paths and confronting their experience of wage labour. We show how wage labour is used to secure the farm and the career path of wage workers. This securizing goes through the learning and conditioning of the function of employer for the farmers and the physical condition of farm labour for the wage workers.La main-d'oeuvre salariée non familiale occupe une part croissante dans l'activité des exploitations. Les auteurs montrent que cette période de salariat constitue une des trajectoires possibles de professionnalisation de futurs agriculteurs et qu'il s'agit ici d'une solution transitoire, vers le statut de chef d'exploitation, vers la retraite ou une activité non agricole plutôt qu'un métier pour la vie. Cette solution transitoire ressort aussi du côté des exploitants

Hépatocarcinome: Pourquoi fermenter quand on peut respirer ?

WOS:000455202200018International audiencePour la troisième année, dans le cadre du module d’enseignement « Physiopathologie de la signalisation » proposé par l’université Paris-sud, les étudiants du Master « Biologie Santé » de l’université Paris-Saclay se sont confrontés à l’écriture scientifique. Ils ont sélectionné 8 articles scientifiques récents dans le domaine de la signalisation cellulaire présentant des résultats originaux, via des approches expérimentales variées, sur des thèmes allant des relations hôte-pathogène aux innovations thérapeutiques, en passant par la signalisation hépatique et le métabolisme. Après un travail préparatoire réalisé avec l’équipe pédagogique, les étudiants, organisés en binômes, ont ensuite rédigé, guidés par des chercheurs, une Nouvelle soulignant les résultats majeurs et l’originalité de l’article étudié. Ils ont beaucoup apprécié cette initiation à l’écriture d’articles scientifiques et, comme vous pourrez le lire, se sont investis dans ce travail avec enthousiasme ! Une de ces Nouvelles est publiée dans ce numéro, les autres le seront dans les prochains numéros de m/s

Rôle des parties prenantes dans la gouvernance de la filière de gestion des déchets des équipements électriques et électroniques

International audienc

Rôle des parties prenantes dans la gouvernance de la filière de gestion des déchets des équipements électriques et électroniques

International audienc

Rôle des parties prenantes dans la gouvernance de la filière de gestion des déchets des équipements électriques et électroniques

International audienc

Liens entre salariat et activité agricole : itinéraires professionnels de salariés d'élevage

Wage labour in farming is increasing and herbivorous livestock farming systems that were hither to family-based are increasingly resorting to it. Few studies have been carried out on wage labour in this type of systems. Yet it impacts both the operation and reproduction of livestock farms. The issue we address here is that of wage labour from the salaried employee’s point of view. We propose to characterize a diversity of individual paths that have led to wage labour. This study reveals a diversity of occupational status sequences, which can lead from a status of salaried employee to that of farmer. It thus reveals forms of relationships between wage labour and agricultural activity other than employment or the functions of a salaried employee on farmsLe salariat agricole se développe et les exploitations agricoles y ont de plus en plus recours, notamment dans des systèmes d’élevage herbivore traditionnellement familiaux. En élevage herbivore, peu de travaux s’y sont intéressés alors qu’il permet de repenser le fonctionnement des exploitations et d’assurer dans certains cas leur reproduction. Nous proposons ici de nous intéresser au salariat, du point de vue des salariés, et de caractériser une diversité d’itinéraires individuels menant au salariat agricole. Nos résultats permettent de révéler une diversité d’enchaînements de statuts professionnels dans l’exercice de l’élevage, qui peut conduire de salarié agricole à chef d’exploitation. Et par la même se dessinent des formes de liens entre activité agricole et salariat autres que l’emploi ou les fonctions affectées aux salariés dans les exploitation

Geological and biological diversity of seeps in the Sea of Marmara

The Sea of Marmara hosts part of the North Anatolian Fault as an active submarine strike-slip fault. This area has suffered numerous earthquakes and presents a major seismic risk. Although the Sea of Marmara has been studied for many years, the link between geological morphostructures, the nature of fluids and biological communities is still rarely described. During the Marsite cruise (November 2014), dives with Remotely Operated Vehicle (ROV) VICTOR 6000 focused on detailed seafloor explorations of four different areas: the Central and Western highs and the Tekirdağ and Çinarcik basins. Based on 130 h of in situ videos, high-resolution seafloor mapping of seeps was conducted, emphasizing their significant geological and biological diversity from one seeping site to another, from one basin/high to another. Gas bubbles (CH4, CO2), shimmering water (brine, marine and fresh water) and oil, escape from the seafloor into the water column with low to strong fluxes. Black patches of reduced sediments, authigenic carbonate crusts and chimneys compose the seep environments with various types of bacterial mats and chemosynthetic fauna. Several venting sites discovered during previous cruises are still active 7–12 years later. The seeps are mostly, but not only, focalized along the Main Marmara Fault (MMF), at the southern border of the Tekirdağ Basin and along the Western High. Fluid emission is also occurring at secondary faults and at their intersection with the MMF. Our study emphasizes the location of seeps at the foot of slopes, gully outlets and crossroads. Sedimentary features, such as mass wastings, stratigraphic discontinuities or canyons, also interact with fluid emissions. The observed fauna is dominated by Bathymodiolinae, Vesicomyidae, Lucinidae-like empty shells and tubiculous worms resembling Ampharetidae polychatea. Most of the symbiont-bearing taxa encountered and previously sampled in the Marmara Sea, are characterized by thiotrophic symbioses. Vesicomyids and Idas sp. mussels are present at gas seeps, but also in areas where crude oil escapes from the seafloor. Moreover, other taxa unusually encountered at cold seeps such as large-sized amphipod and vagile worms were observed in the Çinarcik Basin. Idas-like mussels were observed in the western part of the Sea of Marmara, in the Tekirdağ Basin and possibly on the Western High active seep sites. There, the sampled fluids had high methane content (reaching 65 μmol/l) but not as high as on the Central High (363 μmol/l) and Çinarcik Basin (228 μmol/l) where no mussels were observed in the video records. Bottom waters oxygen levels in the Sea of Marmara showed a west to east decreasing gradient (57–8.5 μmol/l). These oxygen conditions, which fall under the limit of Oxygen Minimum Zones (OMZ <20 μm/l) in the eastern part, may impact benthic fauna and explain the absence of symbiotrophic bivalves at cold seep sites of the Çinarcik Basin, whereas densely aggregated amphipods, likely more tolerant to oxygen stress were observed in the seepage area. Finally, no specific fauna was observed near the CO2-rich seep sites. First observations suggest that seep fauna composition in the Sea of Marmara does not seem to be strongly influenced by the nature (e.g., oil, gas bubbling, brines) of fluid venting through seeps. The seep environments are highly variable and characterized by distinctive geological morphostructures. They sustain typical Mediterranean cold seep fauna, but also unusual communities likely related to the interaction of seeps with hypoxic conditions