p190RhoGAPs, the <i>ARHGAP35</i>- and <i>ARHGAP5</i>-Encoded Proteins, in Health and Disease

Small guanosine triphosphatases (GTPases) gathered in the Rat sarcoma (Ras) superfamily represent a large family of proteins involved in several key cellular mechanisms. Within the Ras superfamily, the Ras homolog (Rho) family is specialized in the regulation of actin cytoskeleton-based mechanisms. These proteins switch between an active and an inactive state, resulting in subsequent inhibiting or activating downstream signals, leading finally to regulation of actin-based processes. The On/Off status of Rho GTPases implicates two subsets of regulators: GEFs (guanine nucleotide exchange factors), which favor the active GTP (guanosine triphosphate) status of the GTPase and GAPs (GTPase activating proteins), which inhibit the GTPase by enhancing the GTP hydrolysis. In humans, the 20 identified Rho GTPases are regulated by over 70 GAP proteins suggesting a complex, but well-defined, spatio-temporal implication of these GAPs. Among the quite large number of RhoGAPs, we focus on p190RhoGAP, which is known as the main negative regulator of RhoA, but not exclusively. Two isoforms, p190A and p190B, are encoded by ARHGAP35 and ARHGAP5 genes, respectively. We describe here the function of each of these isoforms in physiological processes and sum up findings on their role in pathological conditions such as neurological disorders and cancers

Endocom: a wireless endoprosthesis dedicated to the follow-up of abdominal aortic aneurysms

International audienc

Écriture, récit, trouble(s) de soi

Une histoire du « soi » est-elle possible ? Des écrits personnels de tous ordres, livres de raison, diaires et journaux intimes, cahiers personnels, mémoires, correspondances, permettent ici d’interroger les manières, hétérogènes et singulières, par lesquelles l’individu passe au « je » dans l’écriture, fait l’expérience de soi face à un tiers lecteur, déploie une réflexivité critique envers lui-même et envers les autres. Afin d’analyser les liens des pratiques d’écriture à la construction de soi, ce sont les situations de « troubles de soi » comme incohérence, difficulté d’être soi, opacité de soi à soi - et aux autres - que cet ouvrage prend pour objet. Se construit ainsi, dans l’approche diachronique de plusieurs études de cas, l’historicité des figures d’un soi sommé de se légitimer, de se justifier, de se reconnaître, de maintenir par l’écriture son « identité narrative », dans des contextes toujours singuliers

ENDOCOM: Implantable wireless pressure sensor for the follow-up of abdominal aortic aneurysm stented

International audienceAn abdominal aortic aneurysm (AAA) is a dilatation of the aorta at the abdominal level, the rupture of which is a life threatening complication with an 80% mortality rate. Even though those devices keep improving, the failure rate of the endovascular treatment is due to persisting pressure into the excluded aneurysmal sac. Since 2005, several integrated sensors have been designed for the follow-up of the AAA treated by a stent. Solutions are based on the use of a single sensor. Thrombus in the excluded AAA can modify the field of pressure when leaks appeared and a network of sensors should be used. We present in this paper the ENDOCOM project that aims to design an implantable pressure sensor that can be used in a network configuration. To validate the new materials, we developed a framework composed of in vitro experiments and in vivo tests on large animal model. Numerical modeling has been investigated from the experimental data to determine the optimal position of sensor. Some results of those different parts are shown in this paper

RFID implantable pressure sensor for the follow-up of abdominal aortic aneurysm stented

International audienceAn abdominal aortic aneurysm (AAA) is a dilatation of the aorta at the abdominal level, the rupture of which is a life threatening complication with an 80% mortality rate. Even though those devices keep improving, the failure rate of the endovascular treatment is due to persisting pressure into the excluded aneurysmal sac. Since 2005, several integrated sensors have been designed for the follow-up of the AAA treated by a stent. Solutions are based on the use of a single sensor. Thrombus in the excluded AAA can modify the field of pressure when leaks appeared and a network of sensors should be used. We present in this paper the ENDOCOM project that aims to design an implantable pressure sensor that can be used in a network configuration. To validate the new materials, we developed a framework composed of in vitro experiments and in vivo tests on large animal model. Numerical modeling has been investigated from the experimental data to determine the optimal position of sensor. Some results of those different parts are shown in this paper

Vietnam : Histoire et perspectives contemporaines

Moussons consacre un numéro double au Việt Nam : depuis les deux dernières décennies, ce champ particulier des sciences sociales que sont les études vietnamiennes a connu à travers le monde et en France en particulier un renouvellement considérable. Il était donc largement temps non pas d’en dresser un bilan, la vague n’ayant pas encore fini de déferler, mais, simplement, de tenter de présenter un panorama de ce renouveau en construction

Distinct roles of the C2A and the C2B domain of the vesicular Ca2+ sensor synaptotagmin 9 in endocrine β-cells

Synaptotagmins form a family of calcium-sensor proteins implicated in exocytosis, and these vesicular transmembrane proteins are endowed with two cytosolic calcium-binding C2 domains, C2A and C2B. Whereas the isoforms syt1 and syt2 have been studied in detail, less is known about syt9, the calcium sensor involved in endocrine secretion such as insulin release from large dense core vesicles in pancreatic β-cells. Using cell-based assays to closely mimic physiological conditions, we observed SNARE (soluble N-ethylmaleimide-sensitive fusion protein-attachment protein receptor)-independent translocation of syt9C2AB to the plasma membrane at calcium levels corresponding to endocrine exocytosis, followed by internalization to endosomes. The use of point mutants and truncations revealed that initial translocation required only the C2A domain, whereas the C2B domain ensured partial pre-binding of syt9C2AB to the membrane and post-stimulatory localization to endosomes. In contrast with the known properties of neuronal and neuroendocrine syt1 or syt2, the C2B domain of syt9 did not undergo calcium-dependent membrane binding despite a high degree of structural homology as observed through molecular modelling. The present study demonstrates distinct intracellular properties of syt9 with different roles for each C2 domain in endocrine cells