Mascareignes et Seychelles, archipels créoles de l’océan Indien

Mascareignes et Seychelles, deux archipels de l’océan Indien occidental, étaient désertes quand elles ont été colonisées par la France au début des Temps modernes et structurées par un système de plantation. Celui-ci repose sur la production de denrées tropicales pour la métropole sur de grands domaines mis en valeur par une main-d’œuvre esclave ou engagiste d’origines malgache, africaine et indienne. Il détermine une société pluriethnique très inégalitaire dominée par la « plantocratie blanche » peu nombreuse. Il secrète une culture créole, enrichie des apports des grandes civilisations. À partir de 1815, Maurice et les Seychelles intègrent l’Empire colonial britannique. La Réunion et Maurice deviennent des « îles à sucre ». À l’esclavage succède l’engagisme, le coolie trade. L’immigration indienne, importante à La Réunion, est massive à Maurice qui devient une « Inde d’outre-mer ». La décolonisation et la recherche du développement empruntent des voies différentes. Tandis que Maurice et les Seychelles accèdent à l’indépendance, La Réunion devient département français. Les Seychelles optent pour une voie de développement socialiste inspirée de Cuba, Maurice pour l’économie libérale et La Réunion pour une convergence socio-économique avec la France. Il en résulte la constitution d’entités bien différenciées. Les Seychelles, micro-État créole et maritime, se veulent les défenseurs de l’environnement, base de leur économie fondée sur le tourisme et la pêche. Maurice a diversifié son économie sucrière par l’industrie, le tourisme, les services, notamment financiers off shore. La Réunion fait partie des pays développés. La coopération régionale doit resserrer davantage les liens entre ces îles proches par la géographie que l’histoire a séparées et donner corps à l’Indiaocéanie.Mascarene Islands and Seychelles, two archipelagoes in the western Indian Ocean, were desert islands when they were colonized by France at the beginning of Modern Times and structured by a system of plantation. It was based on the production of tropical foodstuffs for the metropolis on large domains developed by slavery and indentured labourers of Malagasy, African and Indian origins. It determined a very unegalitarian multiethnic society dominated by the non numerous “white plantocracy”. It gave birth to a Creole culture, enriched by the contributions of several civilizations. From 1815 onwards, Mauritius and Seychelles integrated the British colonial Empire. Reunion island and Mauritius became “sugar islands”. To the slavery succeeded the indentured labour, the “coolie trade” The Indian immigration, important in Reunion island, was massive in Mauritius which became an “overseas India”. The decolonization and the research for development took different ways. While Mauritius and Seychelles reached their independence, Reunion island became a French “departement”. Seychelles chose the way to a socialist development inspired by Cuba, Mauritius to the free market economy and Reunion to a socio-economic convergence with France. Resulted from it the constitution of widly-differentiated entities. Seychelles, a small maritime State, aimed at being the defenders of the environment; the basis of their economy was established on tourism and fishing. Mauritius diversified its sugar economy developing its industry, tourism, services, in particular offshore finance. Reunion became a part of developed countries. Regional cooperation will have to develop the links woven by these neighbouring islands separated by geography and history and to give body to India-oceania

Endogenous Plasma Peptide Detection and Identification in the Rat by a Combination of Fractionation Methods and Mass Spectrometry

Mass spectrometry-based analyses are essential tools in the field of biomarker research. However, detection and characterization of plasma low abundance and/or low molecular weight peptides is challenged by the presence of highly abundant proteins, salts and lipids. Numerous strategies have already been tested to reduce the complexity of plasma samples. The aim of this study was to enrich the low molecular weight fraction of rat plasma. To this end, we developed and compared simple protocols based on membrane filtration, solid phase extraction, and a combination of both. As assessed by UV absorbance, an albumin depletion >99% was obtained. The multistep fractionation strategy (including reverse phase HPLC) allowed detection, in a reproducible manner (CV < 30%–35%), of more than 450 peaks below 3000 Da by MALDI-TOF/MS. A MALDI-TOF/MS-determined LOD as low as 1 fmol/μL was obtained, thus allowing nanoLC-Chip/MS/MS identification of spiked peptides representing ~10−6% of total proteins, by weight. Signal peptide recovery ranged between 5%–100% according to the spiked peptide considered. Tens of peptide sequence tags from endogenous plasma peptides were also obtained and high confidence identifications of low abundance fibrinopeptide A and B are reported here to show the efficiency of the protocol. It is concluded that the fractionation protocol presented would be of particular interest for future differential (high throughput) analyses of the plasma low molecular weight fraction

Cardiomyocyte Protection by Hibernating Brown Bear Serum: Toward the Identification of New Protective Molecules Against Myocardial Infarction

Ischemic heart disease remains one of the leading causes of death worldwide. Despite intensive research on the treatment of acute myocardial infarction, no effective therapy has shown clinical success. Therefore, novel therapeutic strategies are required to protect the heart from reperfusion injury. Interestingly, despite physical inactivity during hibernation, brown bears (Ursus arctos) cope with cardiovascular physiological conditions that would be detrimental to humans. We hypothesized that bear serum might contain circulating factors that could provide protection against cell injury. In this study, we sought to determine whether addition of bear serum might improve cardiomyocyte survival following hypoxia-reoxygenation. Isolated mouse cardiomyocytes underwent 45 min of hypoxia followed by reoxygenation. At the onset of reoxygenation, cells received fetal bovine serum (FBS; positive control), summer (SBS) or winter bear serum (WBS), or adult serums of other species, as indicated. After 2 h of reoxygenation, propidium iodide staining was used to evaluate cell viability by flow cytometry. Whereas, 0.5% SBS tended to decrease reperfusion injury, 0.5% WBS significantly reduced cell death, averaging 74.04 +/- 7.06% vs. 79.20 +/- 6.53% in the FBS group. This cardioprotective effect was lost at 0.1%, became toxic above 5%, and was specific to the bear. Our results showed that bear serum exerts a therapeutic effect with an efficacy threshold, an optimal dose, and a toxic effect on cardiomyocyte viability after hypoxia-reoxygenation. Therefore, the bear serum may be a potential source for identifying new therapeutic molecules to fight against myocardial reperfusion injury and cell death in general

Hibernating brown bears are protected against atherogenic dyslipidemia

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Limited oxidative stress favors resistance to skeletal muscle atrophy in hibernating brown bears (Ursus Arctos)

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Lipidomics reveals seasonal shifts in a large-bodied hibernator, the brown bear

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Une suite logicielle pour la protéomique interfacée sur une grille de calcul. Utilisation d'algorithmes libres pour l'identification MS/MS, le séquençage de novo et l'annotation fonctionnelle.

International audienceUne suite logicielle pour la protéomique interfacée sur une grille de calcul. Utilisation d'algorithmes libres pour l'identification MS/MS, le séquençage de novo et l'annotation fonctionnelle

Specific shifts in the endocannabinoid system in hibernating brown bears

In small hibernators, global downregulation of the endocannabinoid system (ECS), which is involved in modulating neuronal signaling, feeding behavior, energy metabolism, and circannual rhythms, has been reported to possibly drive physiological adaptation to the hibernating state. In hibernating brown bears (Ursus arctos), we hypothesized that beyond an overall suppression of the ECS, seasonal shift in endocannabinoids compounds could be linked to bear's peculiar features that include hibernation without arousal episodes and capacity to react to external disturbance. We explored circulating lipids in serum and the ECS in plasma and metabolically active tissues in free-ranging subadult Scandinavian brown bears when both active and hibernating. In winter bear serum, in addition to a 2-fold increase in total fatty acid concentration, we found significant changes in relative proportions of circulating fatty acids, such as a 2-fold increase in docosahexaenoic acid C22:6 n-3 and a decrease in arachidonic acid C20:4 n-6. In adipose and muscle tissues of hibernating bears, we found significant lower concentrations of 2-arachidonoylglycerol (2-AG), a major ligand of cannabinoid receptors 1 (CB1) and 2 (CB2). Lower mRNA level for genes encoding CB1 and CB2 were also found in winter muscle and adipose tissue, respectively. The observed reduction in ECS tone may promote fatty acid mobilization from body fat stores, and favor carbohydrate metabolism in skeletal muscle of hibernating bears. Additionally, high circulating level of the endocannabinoid-like compound N-oleoylethanolamide (OEA) in winter could favor lipolysis and fatty acid oxidation in peripheral tissues. We also speculated on a role of OEA in the conservation of an anorexigenic signal and in the maintenance of torpor during hibernation, while sustaining the capacity of bears to sense stimuli from the environment

Lipidomics Reveals Seasonal Shifts in a Large-Bodied Hibernator, the Brown Bear

Prior to winter, heterotherms retain polyunsaturated fatty acids (“PUFA”), resulting in enhanced energy savings during hibernation, through deeper and longer torpor bouts. Hibernating bears exhibit a less dramatic reduction (2–5°C) in body temperature, but lower their metabolism to a degree close to that of small hibernators. We determined the lipid composition, via lipidomics, in skeletal muscle and white adipose tissues (“WAT”), to assess lipid retention, and in blood plasma, to reflect lipid trafficking, of winter hibernating and summer active wild Scandinavian brown bears (Ursus arctos). We found that the proportion of monounsaturated fatty acids in muscle of bears was significantly higher during winter. During hibernation, omega-3 PUFAs were retained in WAT and short-length fatty acids were released into the plasma. The analysis of individual lipid moieties indicated significant changes of specific fatty acids, which are in line with the observed seasonal shift in the major lipid categories and can be involved in specific regulations of metabolisms. These results strongly suggest that the shift in lipid composition is well conserved among hibernators, independent of body mass and of the animals’ body temperature

2D-electrophoresis and multiplex immunoassay proteomic analysis of different body fluids and cellular components reveal known and novel markers for extended fasting

Proteomic technologies applied for profiling human biofluids and blood cells are considered to reveal new biomarkers of exposure or provide insights into novel mechanisms of adaptation