L'époque contemporaine : à la recherche d'une civilisation nouvelle /

Inde

Migrations, Famille et Vieillissement en Martinique

L’enquête « Migrations, Famille et Vieillissement », conçue par une équipe de chercheurs de/associés à l’Ined (Institut national d’études démographiques), est la première enquête Ménage de grande ampleur spécifiquement dédiée aux départements et régions d’outre-mer (Drom). Elle analyse et mesure les mutations sociodémographiques à l’œuvre dans chacun d’entre eux (Marie, 2011). Outre les thématiques centrales que sont les migrations, le vieillissement, la famille et leurs transformations, elle aborde une série de thèmes « secondaires » tout aussi essentiels à la connaissance de ces territoires et à l’examen de leurs spécificités (pratiques linguistiques et religieuses, discriminations, état de santé, etc.). Cette enquête combine représentativité territoriale et comparabilité nationale, voire internationale. Son ambition est également politique : elle a été pensée comme un instrument d’aide à l’élaboration et à la mise en œuvre locale de politiques sociales et sanitaires adaptées. Forte des enseignements des premières éditions conduites en 2009-2010 en Martinique, Guadeloupe, Guyane et La Réunion, puis à Mayotte en 2015-2016 (Marie et al., 2017), cette enquête a été reconduite en 2020-2021 (MFV-2) dans les quatre Drom « historiques » : Guadeloupe, Martinique, Guyane et La Réunion. Le questionnaire réactualisé vise à approfondir la connaissance des dynamiques à l’œuvre dans chacun de ces territoires et des changements qui s’y sont opérés ces dix dernières années, avec l’ambition d’en donner une vision prospective

The European renaissance since 1945

This volume is the logical outgrowth of the previous book Toward a Science of Translating wich explored some of the basic factors constituting a scientific a approach to translationviii,186 p.: ill.; 21 c

Elastic fibers and elastin receptor complex: Neuraminidase-1 takes the center stage

International audienceExtracellular matrix (ECM) has for a long time being considered as a simple architectural support for cells. It is now clear that ECM presents a fundamental influence on cells driving their phenotype and fate. This complex network is highly specialized and the different classes of macromolecules that comprise the ECM determine its biological functions. For instance, collagens are responsible for the tensile strength of tissues, proteoglycans and glycosaminoglycans are essential for hydration and resistance to compression, and glycoproteins such as laminins facilitate cell attachment. The largest structures of the ECM are the elastic fibers found in abundance in tissues suffering high mechanical constraints such as skin, lungs or arteries. These structures present a very complex composition whose core is composed of elastin surrounded by a microfibrils mantle. Elastogenesis is a tightly regulated process involving the sialidase activity of the Neuraminidase-1 (Neu-1) sub-unit of the Elastin Receptor Complex. Interestingly, Neu-1 subunit also serves as a sensor of elastin degradation via its ability to transmit elastin-derived peptides signaling. Finally, reports showing that neuraminidase activity is able to regulate TGF-β activation raises questions about a possible role for Neu-1 in elastic fibers remodeling. In this mini review, we develop the concept of the regulation of the whole life of elastic fibers through an original scope, the key role of Neu-1 sialidase enzymatic activity

Neuraminidase-1: A Sialidase Involved in the Development of Cancers and Metabolic Diseases

Sialidases or neuraminidases (NEU) are glycosidases which cleave terminal sialic acid residues from glycoproteins, glycolipids and oligosaccharides. Four types of mammalian sialidases, which are encoded by different genes, have been described with distinct substrate specificity and subcellular localization: NEU-1, NEU-2, NEU-3 and NEU-4. Among them, NEU-1 regulates many membrane receptors through desialylation which results in either the activation or inhibition of these receptors. At the plasma membrane, NEU-1 also associates with the elastin-binding protein and the carboxypeptidase protective protein/cathepsin A to form the elastin receptor complex. The activation of NEU-1 is required for elastogenesis and signal transduction through this receptor, and this is responsible for the biological effects that are mediated by the elastin-derived peptides (EDP) on obesity, insulin resistance and non-alcoholic fatty liver diseases. Furthermore, NEU-1 expression is upregulated in hepatocellular cancer at the mRNA and protein levels in patients, and this sialidase regulates the hepatocellular cancer cells’ proliferation and migration. The implication of NEU-1 in other cancer types has also been shown notably in the development of pancreatic carcinoma and breast cancer. Altogether, these data indicate that NEU-1 plays a key role not only in metabolic disorders, but also in the development of several cancers which make NEU-1 a pharmacological target of high potential in these physiopathological contexts

Uncoupling of Elastin Complex Receptor during In Vitro Aging Is Related to Modifications in Its Intrinsic Sialidase Activity and the Subsequent Lactosylceramide Production

International audienceDegradation of elastin leads to the production of elastin-derived peptides (EDP), which exhibit several biological effects, such as cell proliferation or protease secretion. Binding of EDP on the elastin receptor complex (ERC) triggers lactosylceramide (LacCer) production and ERK1/2 activation following ERC Neu-1 subunit activation. The ability for ERC to transduce signals is lost during aging, but the mechanism involved is still unknown. In this study, we characterized an in vitro model of aging by subculturing human dermal fibroblasts. This model was used to understand the loss of EDP biological activities during aging. Our results show that ERC uncoupling does not rely on Neu-1 or PPCA mRNA or protein level changes. Furthermore, we observe that the membrane targeting of these subunits is not affected with aging. However, we evidence that Neu-1 activity and LacCer production are altered. Basal Neu-1 catalytic activity is strongly increased in aged cells. Consequently, EDP fail to promote Neu-1 catalytic activity and LacCer production in these cells. In conclusion, we propose, for the first time, an explanation for ERC uncoupling based on the age-related alterations of Neu-1 activity and LacCer production that may explain the loss of EDP-mediated effects occurring during aging

Role of elastin peptides and elastin receptor complex in metabolic and cardiovascular diseases

International audienc

Revealing the elasticity of an individual aortic fiber during ageing at nanoscale by in situ atomic force microscopy †

International audienceArterial stiffness is a complex process affecting the aortic tree that significantly contributes to cardiovascular diseases (systolic hypertension, coronary artery disease, heart failure or stroke). This process involves a large extracellular matrix remodeling mainly associated with elastin content decrease and collagen content increase. Additionally, various chemical modifications that accumulate with ageing have been shown to affect long-lived assemblies, such as elastic fibers, that could affect their elasticity. To precisely characterize the fiber changes and the evolution of its elasticity with ageing, high resolution and multimodal techniques are needed for precise insight into the behavior of a single fiber and its surrounding medium. In this study, the latest developments in atomic force microscopy and the related nanomechanical modes are used to investigate the evolution and in a near-physiological environment, the morphology and elasticity of aorta cross sections obtained from mice of different ages with an unprecedented resolution. In correlation with more classical approaches such as pulse wave velocity and fluorescence imaging, we demonstrate that the relative Young's moduli of elastic fibers, as well as those of the surrounding areas, significantly increase with ageing. This nanoscale characterization presents a new view on the stiffness process, showing that, besides the elastin and collagen content changes, elasticity is impaired at the molecular level, allowing a deeper understanding of the ageing process. Such nanomechanical AFM measurements of mouse tissue could easily be applied to studies of diseases in which elastic fibers suffer pathologies such as atherosclerosis and diabetes, where the precise quantification of fiber elasticity could better follow the fiber remodeling and predict plaque rupture. † Electronic supplementary information (ESI) available. Se