Lysosomal Membrane Permeabilization Induces Cell Death in a Mitochondrion-dependent Fashion

A number of diseases are due to lysosomal destabilization, which results in damaging cell loss. To investigate the mechanisms of lysosomal cell death, we characterized the cytotoxic action of two widely used quinolone antibiotics: ciprofloxacin (CPX) or norfloxacin (NFX). CPX or NFX plus UV light (NFX*) induce lysosomal membrane permeabilization (LMP), as detected by the release of cathepsins from lysosomes. Inhibition of the lysosomal accumulation of CPX or NFX suppresses their capacity to induce LMP and to kill cells. CPX- or NFX-triggered LMP results in caspase-independent cell death, with hallmarks of apoptosis such as chromatin condensation and phosphatidylserine exposure on the plasma membrane. LMP triggers mitochondrial membrane permeabilization (MMP), as detected by the release of cytochrome c. Both CPX and NFX* cause Bax and Bak to adopt their apoptotic conformation and to insert into mitochondrial membranes. Bax−/− Bak−/− double knockout cells fail to undergo MMP and cell death in response to CPX- or NFX-induced LMP. The single knockout of Bax or Bak (but not Bid) or the transfection-enforced expression of mitochondrion-targeted (but not endoplasmic reticulum–targeted) Bcl-2 conferred protection against CPX (but not NFX*)-induced MMP and death. Altogether, our data indicate that mitochondria are indispensable for cell death initiated by lysosomal destabilization

Unexpected Modulation of Recall B and T Cell Responses after Immunization with Rotavirus-like Particles in the Presence of LT-R192G

LT-R192G, a mutant of the thermolabile enterotoxin of E. coli, is a potent adjuvant of immunization. Immune responses are generally analyzed at the end of protocols including at least 2 administrations, but rarely after a prime. To investigate this point, we compared B and T cell responses in mice after one and two intrarectal immunizations with 2/6 rotavirus-like particles (2/6-VLP) and LT-R192G. After a boost, we found, an unexpected lower B cell expansion measured by flow cytometry, despite a secondary antibody response. We then analyzed CD4+CD25+Foxp3+ regulatory T cells (Tregs) and CD4+CD25+Foxp3− helper T cells after in vitro (re)stimulation of mesenteric lymph node cells with the antigen (2/6-VLP), the adjuvant (LT-R192G) or both. 2/6-VLP did not activate CD4+CD25+Foxp3− nor Foxp3+ T cells from non-immunized and 2/6-VLP immunized mice, whereas they did activate both subsets from mice immunized with 2/6-VLP in the presence of adjuvant. LT-R192G dramatically decreased CD4+CD25+Foxp3+ T cells from non-immunized and 2/6-VLP immunized mice but not from mice immunized with 2/6-VLP and adjuvant. Moreover, in this case, LT-R192G increased Foxp3 expression on CD4+CD25+Foxp3+ cells, suggesting specific Treg activation during the recall. Finally, when both 2/6-VLP and LT-R192G were used for restimulation, LT-R192G clearly suppressed both 2/6-VLP-specific CD4+CD25+Foxp3− and Foxp3+ T cells. All together, these results suggest that LT-R192G exerts different effects on CD4+CD25+Foxp3+ T cells, depending on a first or a second contact. The unexpected immunomodulation observed during the recall should be considered in designing vaccination protocols

Prosthetic overhang is the most effective way to prevent scapular conflict in a reverse total shoulder prosthesis

Methods An average and a "worst case scenario" shape in A-P view in a 2-D computer model of a scapula was created, using data from 200 "normal" scapulae, so that the position of the glenoid and humeral component could be changed as well as design features such as depth of the polyethylene insert, the size of glenosphere, the position of the center of rotation, and downward glenoid inclination. The model calculated the maximum adduction (notch angle) in the scapular plane when the cup of the humeral component was in conflict with the scapula. Results A change in humeral neck shaft inclination from 155 degrees to 145 degrees gave a 10 degrees gain in notch angle. A change in cup depth from 8 mm to 5 mm gave a gain of 12 degrees. With no inferior prosthetic overhang, a lateralization of the center of rotation from 0 mm to 5 mm gained 16 degrees. With an inferior overhang of only 1 mm, no effect of lateralizing the center of rotation was noted. Downward glenoid inclination of 0 boolean OR to 10 boolean OR gained 10 degrees. A change in glenosphere radius from 18 mm to 21 mm gained 31 degrees due to the inferior overhang created by the increase in glenosphere. A prosthetic overhang to the bone from 0 mm to 5 mm gained 39 degrees. Interpretation Of all 6 solutions tested, the prosthetic overhang created the biggest gain in notch angle and this should be considered when designing the reverse arthroplasty and defining optimal surgical technique

The αGal Epitope of the Histo-Blood Group Antigen Family Is a Ligand for Bovine Norovirus Newbury2 Expected to Prevent Cross-Species Transmission

Among Caliciviridae, the norovirus genus encompasses enteric viruses that infect humans as well as several animal species, causing gastroenteritis. Porcine strains are classified together with human strains within genogroup II, whilst bovine norovirus strains represent genogroup III. Various GI and GII human strains bind to carbohydrates of the histo-blood group family which may be shared among mammalian species. Genetic relatedness of human and animal strains as well as the presence of potentially shared ligands raises the possibility of norovirus cross-species transmission. In the present study, we identified a carbohydrate ligand for the prototype bovine norovirus strain Bo/Newbury2/76/UK (NB2). Attachment of virus-like particles (VLPs) of the NB2 strain to bovine gut tissue sections showed a complete match with the staining by reagents recognizing the Galα1,3 motif. Alpha-galactosidase treatment confirmed involvement of a terminal alpha-linked galactose. Specific binding of VLPs to the αGal epitope (Galα3Galβ4GlcNAcβ-R) was observed. The binding of Galα3GalαOMe to rNB2 VLPs was characterized at atomic resolution employing saturation transfer difference (STD) NMR experiments. Transfection of human cells with an α1,3galactosyltransferase cDNA allowed binding of NB2 VLPs, whilst inversely, attachment to porcine vascular endothelial cells was lost when the cells originated from an α1,3galactosyltransferase KO animal. The αGal epitope is expressed in all mammalian species with the exception of the Hominidaea family due to the inactivation of the α1,3galactosyltransferase gene (GGTA1). Accordingly, the NB2 carbohydrate ligand is absent from human tissues. Although expressed on porcine vascular endothelial cells, we observed that unlike in cows, it is not present on gut epithelial cells, suggesting that neither man nor pig could be infected by the NB2 bovine strain

Les matériaux de construction dans l'architecture médiévale à Thouars (Deux-Sèvres)

Poncet Didier. Les matériaux de construction dans l'architecture médiévale à Thouars (Deux-Sèvres). In: La pierre dans la ville antique et médiévale. Actes du colloque d’Argentomagus Tours : Fédération pour l'édition de la Revue archéologique du Centre de la France, 2000. pp. 179-182. (Supplément à la Revue archéologique du centre de la France, 18

Les matériaux de construction dans l'architecture médiévale à Thouars (Deux-Sèvres)

Poncet Didier. Les matériaux de construction dans l'architecture médiévale à Thouars (Deux-Sèvres). In: La pierre dans la ville antique et médiévale. Actes du colloque d’Argentomagus Tours : Fédération pour l'édition de la Revue archéologique du Centre de la France, 2000. pp. 179-182. (Supplément à la Revue archéologique du centre de la France, 18

Rumen digestion and intestinal nutrient flows in sheep consuming pea seeds: the effect of extrusion or chestnut tannin addition

Different treatments aimed at reducing rumen degradability of pea protein were evaluated by in situ and in vivo measurements of rumen and intestine digestion of proteins. Four fistulated sheep were used. Pea seed provided 50% of dietary crude protein (CP) and was used raw (RP), with chestnut tannin (RPT2, 20 g$\cdot$kg$^{-1}$ of pea CP; RPT3, 30 g$\cdot$kg$^{-1}$ of pea CP), and extruded (EP). Rumen in situ degradability of pea protein was decreased by extrusion (83.3% vs. 90.8%) but was not affected by tannin addition. In vivo tannin addition did not affect the organic matter (OM) and N apparent digestibility, at the level of the rumen, the intestine or the whole tract. Extrusion decreased the apparent digestion of OM in the rumen but increased it in the small intestine. Total tract OM digestibility was not affected. Duodenal flow of non-ammonia N (NAN) increased by 27% between the RP and EP diet. This increase was mainly related to an increase in non-microbial N flow. Small intestine NAN apparent digestibility was not affected by extrusion and the amount of NAN apparently digested in the small intestine increased by 23% between the RP and EP diet. A slight decrease in total tract N digestibility was observed with extrusion. The efficiency of microbial protein synthesis was increased by extrusion. Small intestine apparent digestion of amino acids was greater for EP than for RP, but the profile of apparently absorbed amino acids was not affected. This study showed that low doses of tannins (up to 30 g$\cdot$kg$^{-1}$ of pea CP, 15 g$\cdot$kg$^{-1}$ of dietary CP) were inefficient in decreasing protein rumen degradability, however, the extrusion treatment largely increased the nitrogenous value of the pea seeds.Dégradation ruminale et digestion intestinale de la graine de pois : effets de l'extrusion ou d'un ajout de tannins de châtaignier. L'effet de différents traitements visant à diminuer la dégradabilité ruminale des protéines du pois a été évalué par des mesures in situ et in vivo de la digestion ruminale et intestinale. Quatre moutons fistulés ont été utilisés. La graine de pois constituait 50 % de la matière azotée totale (MAT) de la ration. Le pois a été distribué cru (RP), avec des tannins de châtaignier (RPT2, 2 % de la MAT du pois ; RPT3, 3 % de la MAT du pois) ou extrudé. La dégradabilité théorique du pois a diminué sous l'effet du traitement d'extrusion (83,3 % vs. 90,8 %), mais n'a pas été affectée par l'ajout de tannins. In vivo, l'addition de tannin n'a eu aucun effet sur les paramètres de la digestion de la matière organique (MO) et de l'N. L'extrusion a diminué la digestion apparente de la MO dans le rumen, mais celle-ci a augmenté dans l'intestin grêle. Ainsi la digestibilité de la MO dans l'ensemble du tube digestif n'a pas été modifiée. Le flux duodénal de NAN a augmenté de 27 % entre les régimes RP et EP. Cette augmentation s'explique essentiellement par une augmentation du flux de NAN non-microbien. La digestibilité intestinale apparente n'a pas été modifiée par l'extrusion et la quantité de NAN apparemment digérée dans l'intestin grêle a augmenté de 23 % entre les régimes RP et EP. Une légère diminution de la digestibilité totale de l'N a été observée avec le traitement d'extrusion. L'efficacité de la synthèse de protéines microbiennes a été supérieure avec le régime EP. La quantité d'acides aminés apparemment digérée dans l'intestin grêle a été plus élevée avec le régime EP qu'avec le régime RP, mais le profil des acides aminés apparemment absorbés n'a pas été modifié. Cette étude montre que des faibles doses de tannins (jusqu'à 3 % de la MAT du pois, ou 1,5 % de la MAT de la ration) sont inefficaces pour diminuer la dégradabilité ruminale de la graine de pois, par contre l'extrusion peut largement améliorer la valeur azotée de ce protéagineux

Partitioning of nitrogen net fluxes across the portal-drained viscera in sheep: effect of dietary protein rumen degradability

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