La Flèche – Château des Carmes

L’ancienne forteresse de La Flèche, transformée en couvent dès le xviie s. par les religieuses des Carmes, est aujourd’hui occupée par les services municipaux de la ville. Le projet de construction d’un nouvel hôtel de ville, à l’arrière des anciens bâtiments conventuels, a entraîné l’intervention du Service régional de l’archéologie. Grâce au financement de la Ville, un diagnostic archéologique et une étude historique ont été effectués sur le château lui-même, d’autre part, une étude documen..

Nantes – Château des Ducs de Bretagne

Une campagne de fouilles archéologiques a été menée au château des Ducs de Bretagne de Nantes, dans la tour des Jacobins. Parallèlement aux travaux de terrain, une étude d’archives a été réalisée. À l’origine, cette recherche devait concerner le secteur fouillé, cependant elle s’est rapidement étendue à l’ensemble du château. Un inventaire des documents d’archives existants a été entrepris. Les fonds analysés en priorité, ont été ceux qui étaient susceptibles de correspondre au secteur étudié..

Oudon – Le Château

Dans le cadre d’un programme de restauration intérieure de la tour d’Oudon, le Service régional de l’archéologie a été consulté afin de mieux connaître l’histoire du château. Plutôt que d’entreprendre une campagne de fouilles qui n’était pas indispensable, il a été proposé de faire une recherche historique et de réaliser une exposition au rez-de-chaussée de l’édifice devant permettre aux visiteurs de mieux connaître son histoire. Bien que les sources d’archives n’avaient pas la richesse escom..

Oudon (Loire-Atlantique). Le château

Rouaud-Rouaze Isabelle. Oudon (Loire-Atlantique). Le château. In: Archéologie médiévale, tome 23, 1993. p. 439

Oudon (Loire-Atlantique). Le château

Rouaud-Rouaze Isabelle. Oudon (Loire-Atlantique). Le château. In: Archéologie médiévale, tome 23, 1993. p. 439

The ACE2 Receptor for Coronavirus Entry Is Localized at Apical Cell—Cell Junctions of Epithelial Cells

Transmembrane proteins of adherens and tight junctions are known targets for viruses and bacterial toxins. The coronavirus receptor ACE2 has been localized at the apical surface of epithelial cells, but it is not clear whether ACE2 is localized at apical Cell—Cell junctions and whether it associates with junctional proteins. Here we explored the expression and localization of ACE2 and its association with transmembrane and tight junction proteins in epithelial tissues and cultured cells by data mining, immunoblotting, immunofluorescence microscopy, and co-immunoprecipitation experiments. ACE2 mRNA is abundant in epithelial tissues, where its expression correlates with the expression of the tight junction proteins cingulin and occludin. In cultured epithelial cells ACE2 mRNA is upregulated upon differentiation and ACE2 protein is widely expressed and co-immunoprecipitates with the transmembrane proteins ADAM17 and CD9. We show by immunofluorescence microscopy that ACE2 colocalizes with ADAM17 and CD9 and the tight junction protein cingulin at apical junctions of intestinal (Caco-2), mammary (Eph4) and kidney (mCCD) epithelial cells. These observations identify ACE2, ADAM17 and CD9 as new epithelial junctional transmembrane proteins and suggest that the cytokine-enhanced endocytic internalization of junction-associated protein complexes comprising ACE2 may promote coronavirus entry

Optimization of cytotoxic activity of Nocardia sp culture broths using a design of experiments

International audienceIn the context of research for new cytotoxic compounds, obtaining bioactive molecules from renewable sources remain a big challenge. Microorganisms and more specifically Actinobacteria from original sources are well known for their biotechnological potential and are hotspots for the discovery of new bioactive compounds. The strain DP94 studied here had shown an interesting cytotoxic activity of its culture broth (HaCaT IC50 = 8.0 ± 1.5 μg/mL; B16 IC50 = 4.6 ± 1.8 μg/mL), which could not been explained by the compounds isolated in a previous work. The increase of the cytotoxic activity of extracts was investigated, based on a Taguchi L9 orthogonal array design, after DP94 culture in TY medium using two different vessels (bioreactor or Erlenmeyer flasks). Various culture parameters such as temperature, pH and inoculum ratio (%) were studied. For experiments conducted in a bioreactor, stirring speed was included as an additional parameter. Significant differences in the cytotoxic activities of different extracts on B16 melanoma cancer cell lines, highlighted the influence of culture temperature on the production of cytotoxic compound(s) using a bioreactor. A culture in Erlenmeyer flasks was also performed and afforded an increase of the production of the active compounds. The best conditions for the highest cytotoxicity (IC50 on B16 6 ± 0.5 μg/mL) and the highest yield (202.0 mg/L) were identified as pH 6, temperature 37°C and 5% inoculum

DNA damage protection, antioxidant and free-radical scavenging activities of Myriophyllum alterniflorum DC (Haloragaceae) vegetative parts

International audienceDNA damage induced by free radicals is associated with mutation-based health impairment and cancers. The protective effect of five different extracts from an aquatic macrophyte, the alternate watermilfoil Myriophyllum alterniflorum DC (Haloragaceae), is investigated on the DNA disruption mediated by hydroxyl (HO*) and hydroperoxyl (HOO*) radicals, and their antioxidant activity on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals and O2*-. Indeed, M. alterniflorum is supposed to be a good candidate for DNA protection as this species was recently used in ecological surveys as a bioindicator of water quality because of its ability to cope with and to reflect the heavy-metal pollution through variations of antioxidant contents. Moreover, preliminary results indicated higher levels of scavengers specialized in reactive oxygen species reduction, than common medicinal plants. Acetone and ethanol extracts from vegetative parts limit significantly the oxidative damage of plasmid DNA induced by Fenton-reaction reactive oxygen species. The radical antioxidant activities of acetone and aqueous extracts are higher than those of other solvents: [DPPH] IC50 = 2.4 ± 0.2 mg.ml-1 and [O2*-] AI50 = 220.0 ± 14.1 μg.ml-1, respectively. Protection towards free radicals is correlated with high contents of antioxidant compounds in acetone extracts [phenol compounds: 21.00 ± 0.69 mg gallic acid.g-1 DW (dry weight)] and aqueous extracts (flavonoids: 125.48 ± 1.26 mg rutin.g-1 DW). Myriophyllum alterniflorum can be regarded as a promising natural-product source of antigenotoxics and antioxidants and could be envisaged for therapeutic purposes

The PLEKHA7-PDZD11 complex regulates the localization of the calcium pump PMCA and calcium handling in cultured cells

The Plasma Membrane Calcium ATPase (PMCA) extrudes calcium from the cytosol to the extracellular space to terminate calcium-dependent signaling. Although the distribution of PMCA is crucial for its function in calcium homeostasis and signaling, the molecular mechanisms that regulate the localization of PMCA isoforms are not well understood. PLEKHA7 is a junctional protein implicated by genetic studies in hypertension and the regulation of calcium handling. PLEKHA7 recruits the small adaptor protein PDZD11 to adherens junctions, and together they control the trafficking and localization of plasma membrane-associated proteins, including the Menkes copper ATPase. Since PDZD11 binds to the C-terminal domain of b-isoforms of PMCA, PDZD11 and its interactor PLEKHA7 could control the localization and activity of PMCA. Here we test this hypothesis using cultured cell model systems. We showed using immunofluorescence microscopy and a surface biotinylation assay show that KO of either PLEKHA7 or PDZD11 in mouse kidney collecting duct (mCCD) epithelial cells resulted in increased accumulation of endogenous PMCA at lateral cell-cell contacts and PDZ-dependent ectopic apical localization of exogenous PMCA4x/b isoform. In HeLa cells, co-expression of PDZD11 reduced membrane accumulation of overexpressed PMCAx/b and analysis of cytosolic calcium transients showed an effect of PDZD11 on the amplitude of the calcium peaks induced by the expression of PMCA4x/b, but not PMCA4x/a, which lacks the PDZ-binding motif. Moreover, KO of PDZD11 in either endothelial (bEnd.3) or epithelial (mCCD) cells increased the rate of calcium extrusion. Collectively, these results suggest that the PLEKHA7-PDZD11 complex modulates calcium homeostasis by regulating the localization of PMCA