"A Walk of Art". Promenade muséale pour la collection de la Tate (Londres, GB)

Au Royaume-Uni depuis 2001, l’accès au musée est gratuit, mais population se rendant dans les institutions s’est très peu diversifiée. De plus, les expositions temporaires sont quant à elles tarifées, et souvent chères. Le but de A Walk of Art est de mettre en place un espace muséal, qui attirerait un public large et varié. Pour ce faire, plusieurs programmes sont mis en lien, tous accessibles gratuitement : des surfaces d’expositions, des vues cadrées sur divers points de la ville, un belvédère, ainsi qu’une scène pour des spectacles divertissants. Ces différents programmes s’organisent comme une promenade sur une rampe continue montant vers le belvédère qui en est le couronnement conclusif. Les œuvres d’art exposées appartiennent aux collections de la Tate, institution emblématique londonienne, qui viendrait montrer dans ce nouvel espace les pièces de ses réserves qu’elle pourrait ainsi valoriser. Ceci permet de varier les expositions au fil des saisons et de mettre en lumière des travaux méconnus. La rampe, en béton brut, rappelle une promenade extérieure ; elle est fermée à l’aide de grands vitrages, variant de la transparence à l’opacité, permettent de moduler les ambiances le long du parcours. Aménagée au point culminant de la rampe, une plate-forme extérieure avec gradins permet l’organisation de manifestations festives qui peuvent diversifier les publics fréquentant cet espace muséal

Signal transduction in primary human t lymphocytes in altered gravity during parabolic flight and clinostat experiments

BACKGROUND/AIMS: Several limiting factors for human health and performance in microgravity have been clearly identified arising from the immune system, and substantial research activities are required in order to provide the basic information for appropriate integrated risk management. The gravity-sensitive nature of cells of the immune system renders them an ideal biological model in search for general gravity-sensitive mechanisms and to understand how the architecture and function of human cells is related to the gravitational force and therefore adapted to life on Earth. METHODS: We investigated the influence of altered gravity in parabolic flight and 2D clinostat experiments on key proteins of activation and signaling in primary T lymphocytes. We quantified components of the signaling cascade 1.) in non-activated T lymphocytes to assess the "basal status" of the cascade and 2.) in the process of activation to assess the signal transduction. RESULTS: We found a rapid decrease of CD3 and IL-2R surface expression and reduced p-LAT after 20 seconds of altered gravity in non-activated primary T lymphocytes during parabolic flight. Furthermore, we observed decreased CD3 surface expression, reduced ZAP-70 abundance and increased histone H3-acetylation in activated T lymphocytes after 5 minutes of clinorotation and a transient downregulation of CD3 and stable downregulation of IL-2R during 60 minutes of clinorotation. CONCLUSION: CD3 and IL-2R are downregulated in primary T lymphocytes in altered gravity. We assume that a gravity condition around 1g is required for the expression of key surface receptors and appropriate regulation of signal molecules in T lymphocytes

Identification of reference genes in human myelomonocytic cells for gene expression studies in altered gravity

Gene expression studies are indispensable for investigation and elucidation of molecular mechanisms. For the process of normalization, reference genes ("housekeeping genes") are essential to verify gene expression analysis. Thus, it is assumed that these reference genes demonstrate similar expression levels over all experimental conditions. However, common recommendations about reference genes were established during 1 g conditions and therefore their applicability in studies with altered gravity has not been demonstrated yet. The microarray technology is frequently used to generate expression profiles under defined conditions and to determine the relative difference in expression levels between two or more different states. In our study, we searched for potential reference genes with stable expression during different gravitational conditions (microgravity, normogravity, and hypergravity) which are additionally not altered in different hardware systems. We were able to identify eight genes (ALB, B4GALT6, GAPDH, HMBS, YWHAZ, ABCA5, ABCA9, and ABCC1) which demonstrated no altered gene expression levels in all tested conditions and therefore represent good candidates for the standardization of gene expression studies in altered gravity

Microsatellite analysis indicates an absence of population structure among Hippoglossus hippoglossus in the north-west Atlantic

To explore the population structure of Atlantic halibut Hippoglossus hippoglossus, 160 fish from four locations in the north-west Atlantic (Bay of Fundy, Scotian Shelf, Gulf of St Lawrence and Iceland) were examined for evidence of population structure using 18 microsatellite markers. Pair-wise FST and a model-based cluster analysis revealed no significant differentiation between samples, although uncertainties surrounding Atlantic halibut reproductive behaviour made it difficult to ascertain that only a single breeding population had been sampled at each locationPeer reviewed: YesNRC publication: Ye

Regulation of ICAM-1 in cells of the monocyte/macrophage system in microgravity

Cells of the immune system are highly sensitive to altered gravity, and the monocyte as well as the macrophage function is proven to be impaired under microgravity conditions. In our study, we investigated the surface expression of ICAM-1 protein and expression of ICAM-1 mRNA in cells of the monocyte/macrophage system in microgravity during clinostat, parabolic flight, sounding rocket, and orbital experiments. In murine BV-2 microglial cells, we detected a downregulation of ICAM-1 expression in clinorotation experiments and a rapid and reversible downregulation in the microgravity phase of parabolic flight experiments. In contrast, ICAM-1 expression increased in macrophage-like differentiated human U937 cells during the microgravity phase of parabolic flights and in long-term microgravity provided by a 2D clinostat or during the orbital SIMBOX/Shenzhou-8 mission. In nondifferentiated U937 cells, no effect of microgravity on ICAM-1 expression could be observed during parabolic flight experiments. We conclude that disturbed immune function in microgravity could be a consequence of ICAM-1 modulation in the monocyte/macrophage system, which in turn could have a strong impact on the interaction with T lymphocytes and cell migration. Thus, ICAM-1 can be considered as a rapid-reacting and sustained gravity-regulated molecule in mammalian cells

Severe disruption of the cytoskeleton and immunologically relevant surface molecules in a human macrophageal cell line in microgravity — Results of an in vitro experiment on board of the Shenzhou-8 space mission

During spaceflight the immune system is one of the most affected systems of the human body. During the SIMBOX (Science in Microgravity Box) mission on Shenzhou-8, we investigated microgravity-associated long-term alterations in macrophageal cells, the most important effector cells of the immune system. We analyzed the effect of long-term microgravity on the cytoskeleton and immunologically relevant surface molecules. Human U937 cells were differentiated into a macrophageal phenotype and exposed to microgravity or 1g on a reference centrifuge on-orbit for 5 days. After on-orbit fixation, the samples were analyzed with immunocytochemical staining and confocal microscopy after landing. The unmanned Shenzhou-8 spacecraft was launched on board a Long March 2F (CZ-2F) rocket from the Jiuquan Satellite Launch Center (JSLC) and landed after a 17-day-mission. We found a severely disturbed actin cytoskeleton, disorganized tubulin and distinctly reduced expression of CD18, CD36 and MHC-II after the 5 days in microgravity. The disturbed cytoskeleton, the loss of surface receptors for bacteria recognition, the activation of T lymphocytes, the loss of an important scavenger receptor and of antigen-presenting molecules could represent a dysfunctional macrophage phenotype. This phenotype in microgravity would be not capable of migrating or recognizing and attacking pathogens, and it would no longer activate the specific immune system, which could be investigated in functional assays. Obviously, the results have to be interpreted with caution as the model system has some limitations and due to numerous technical and biological restrictions (e.g. 23 °C and no CO2 supply during in-flight incubation). All parameter were carefully pre-tested on ground. Therefore, the experiment could be adapted to the experimental conditions available on Shenzhou-8