Helping neurons to compensate for proteotoxic stress and maintain function over time (neuronal compensation) has therapeutic potential in aging and neurodegenerative disease. The stress response ...factor FOXO3 is neuroprotective in models of Huntington's disease (HD), Parkinson's disease and motor-neuron diseases. Neuroprotective compounds acting in a FOXO-dependent manner could thus constitute bona fide drugs for promoting neuronal compensation. However, whether FOXO-dependent neuroprotection is a common feature of several compound families remains unknown. Using drug screening in C. elegans nematodes with neuronal expression of human exon-1 huntingtin (128Q), we found that 3ß-Methoxy-Pregnenolone (MAP4343), 17ß-oestradiol (17ßE2) and 12 flavonoids including isoquercitrin promote neuronal function in 128Q nematodes. MAP4343, 17ßE2 and isoquercitrin also promote stress resistance in mutant Htt striatal cells derived from knock-in HD mice. Interestingly, daf-16/FOXO is required for MAP4343, 17ßE2 and isoquercitrin to sustain neuronal function in 128Q nematodes. This similarly applies to the GSK3 inhibitor lithium chloride (LiCl) and, as previously described, to resveratrol and the AMPK activator metformin. Daf-16/FOXO and the targets engaged by these compounds define a sub-network enriched for stress-response and neuronally-active pathways. Collectively, these data highlights the dependence on a daf-16/FOXO-interaction network as a common feature of several compound families for prolonging neuronal function in HD.
Class E vacuolar protein‐sorting (Vps) proteins were first described in yeast as being involved in receptor‐mediated endocytosis and multivesicular body formation. Inactivation by RNA interference of ...the class E VPS genes of the nematode Caenorhabditis elegans revealed heterogeneous phenotypes. We have further characterized the role of the essential gene Cevps‐27, ortholog of human hepatocyte growth factor‐regulated tyrosine kinase substrate, during the development of C. elegans. Use of green fluorescent protein fusion constructs and antibody staining revealed that Cevps‐27 localizes to endosomal membranes. It is widely expressed but enriched in epithelial cells. Cevps‐27 mutants presented enlarged endosomal structures and an accumulation of autophagic vesicles as revealed by electron microscopy and the analysis of the autophagic marker LGG‐1. Cevps‐27 animals arrested at L2‐L3 molt with an inability to degrade their old cuticle. This molting phenotype was more severe when Cevps‐27 worms were grown on suboptimal concentrations of cholesterol. Furthermore, defective endocytic trafficking of the low‐density lipoprotein receptor‐related protein 1 (LRP‐1) was also observed in Cevps‐27 mutants. These results indicate that CeVPS‐27 is required for endosomal and autophagic pathways in C. elegans and plays a crucial role in the control of molting through LRP‐1 internalization and cholesterol traffic.
AQP3 is a water and glycerol channel present on human erythrocytes and in various tissues. By protein and molecular biology
analysis, two unrelated probands who developed alloantibodies to the high ...frequency antigen GIL were found to be AQP3-deficient.
The defect is caused by homozygous mutation affecting the 5â² donor splice site of intron 5 of the AQP3 gene. This mutation causes the skipping of exon 5 and generates a frameshift and premature stop codon. Functional studies
by 90° light scattering using a stopped-flow spectrometer revealed the absence of facilitated glycerol transport across red
cell membranes from the probands, but the water and urea transports were normal. Expression studies into COS-7 cells followed
by flow cytometry analysis showed that only cells transfected with AQP3 cDNA strongly reacted with anti-GIL antibodies. These
findings represent the first reported cases of AQP3 deficiency in humans and provide the molecular basis of a new blood group
system, GIL, encoded by the AQP3 protein.
ABSTRACT Background Helicobacter pylori infection‐associated gastric adenocarcinoma is influenced by various factors, including the digestive microbiota. Lactic acid bacteria role in digestive ...carcinogenesis has been discussed, and some Lactobacillaceae family species have been shown to act against H. pylori ‐induced inflammation and colonization. However, their effects on H. pylori ‐related carcinogenesis have not yet been studied. Lactobacillaceae family effects on the epithelial‐to‐mesenchymal transition (EMT), emergence of cells with cancer stem cell (CSC) properties and the pro‐inflammatory response of gastric epithelial cells to H. pylori infection were investigated. Materials and Methods A co‐culture model of AGS gastric epithelial cells infected with a carcinogenic strain of H. pylori associated with 18 different probiotic strains candidates were used. Different EMT indicators and CSC properties were studied, including quantification of the mesenchymal phenotype, tumorsphere formation, EMT marker expression, and tight junction evaluation with immunofluorescence microscopy. The effect of the strains on the pro‐inflammatory response to H. pylori was also evaluated by quantifying interleukin‐8 (IL‐8) production using ELISA. Results Among the strains tested, Lactobacillus gasseri BIO6369 and Lacticaseibacillus rhamnosus BIO5326 induced a 30.6% and 38.4% reduction in the mesenchymal phenotype, respectively, caused a significant decrease in Snail and Zeb1 EMT marker expression and prevented the loss of tight junctions induced by H. pylori infection. A separate co‐culture with a Boyden chamber maintained the effects induced by the two strains. H. pylori ‐induced IL‐8 production was also significantly reduced in the presence of L. gasseri BIO6369 and L. rhamnosus BIO5326. Conclusion Lactobacillus gasseri BIO6369 and L. rhamnosus BIO5326 strains decreased epithelial‐to‐mesenchymal transition and inflammation induced by H. pylori infection, suggesting that these species may have a protective effect against H. pylori ‐induced gastric carcinogenesis.
The Kidd (JK) blood group locus encodes the urea transporter hUT-B1, which is expressed on human red blood cells and other tissues. The common JK*A/JK*B blood group polymorphism is caused by a single ...nucleotide transition G838A changing Asp-280 to Asn-280 on the polypeptide, and transfection of erythroleukemic K562 cells with hUT-B1 cDNAs carrying either the G838 or the A838 nucleotide substitutions resulted in the isolation of stable clones that expressed the Jka or Jkb antigens, respectively, thus providing the first direct demonstration that the hUT-B1 gene encodes the Kidd blood group antigens. In addition, immunochemical analysis of red blood cells demonstrated that hUT-B1 also exhibits ABO determinants attached to the single N-linked sugar chain at Asn-211. Moreover, immunoadsorption studies, using inside-out and right-side-out red cell membrane vesicles as competing antigen, demonstrated that the C- and N-terminal ends of hUT-B1 are oriented intracellularly. Mutagenesis and functional studies by expression in Xenopus oocytes revealed that both cysteines Cys-25 and Cys-30 (but not alone) are essential for plasma membrane addressing. Conversely, the transport function was not affected by the JK*A/JK*Bpolymorphism, C-terminal deletion (residues 360–389), or mutation of the extracellular N-glycosylation consensus site and remains poorly para-chloromercuribenzene sulfonate (pCMBS)-sensitive. However, transport studies by stopped flow light scattering using Jk-K562 transfectants demonstrated that the hUT-B1-mediated urea transport is pCMBS-sensitive in an erythroid context, as reported previously for the transporter of human red blood cells. Mutagenesis analysis also indicated that Cys-151 and Cys-236, at least alone, are not involved in pCMBS inhibition. Altogether, these antigenic, topologic, and functional properties might have implications into the physiology of hUT-B1 and other members of the urea transporter family.
Helicobacter pylori infection-associated gastric adenocarcinoma is influenced by various factors, including the digestive microbiota. Lactic acid bacteria role in digestive carcinogenesis has been ...discussed, and some Lactobacillaceae family species have been shown to act against H. pylori-induced inflammation and colonization. However, their effects on H. pylori-related carcinogenesis have not yet been studied. Lactobacillaceae family effects on the epithelial-to-mesenchymal transition (EMT), emergence of cells with cancer stem cell (CSC) properties and the pro-inflammatory response of gastric epithelial cells to H. pylori infection were investigated.BACKGROUNDHelicobacter pylori infection-associated gastric adenocarcinoma is influenced by various factors, including the digestive microbiota. Lactic acid bacteria role in digestive carcinogenesis has been discussed, and some Lactobacillaceae family species have been shown to act against H. pylori-induced inflammation and colonization. However, their effects on H. pylori-related carcinogenesis have not yet been studied. Lactobacillaceae family effects on the epithelial-to-mesenchymal transition (EMT), emergence of cells with cancer stem cell (CSC) properties and the pro-inflammatory response of gastric epithelial cells to H. pylori infection were investigated.A co-culture model of AGS gastric epithelial cells infected with a carcinogenic strain of H. pylori associated with 18 different probiotic strains candidates were used. Different EMT indicators and CSC properties were studied, including quantification of the mesenchymal phenotype, tumorsphere formation, EMT marker expression, and tight junction evaluation with immunofluorescence microscopy. The effect of the strains on the pro-inflammatory response to H. pylori was also evaluated by quantifying interleukin-8 (IL-8) production using ELISA.MATERIALS AND METHODSA co-culture model of AGS gastric epithelial cells infected with a carcinogenic strain of H. pylori associated with 18 different probiotic strains candidates were used. Different EMT indicators and CSC properties were studied, including quantification of the mesenchymal phenotype, tumorsphere formation, EMT marker expression, and tight junction evaluation with immunofluorescence microscopy. The effect of the strains on the pro-inflammatory response to H. pylori was also evaluated by quantifying interleukin-8 (IL-8) production using ELISA.Among the strains tested, Lactobacillus gasseri BIO6369 and Lacticaseibacillus rhamnosus BIO5326 induced a 30.6% and 38.4% reduction in the mesenchymal phenotype, respectively, caused a significant decrease in Snail and Zeb1 EMT marker expression and prevented the loss of tight junctions induced by H. pylori infection. A separate co-culture with a Boyden chamber maintained the effects induced by the two strains. H. pylori-induced IL-8 production was also significantly reduced in the presence of L. gasseri BIO6369 and L. rhamnosus BIO5326.RESULTSAmong the strains tested, Lactobacillus gasseri BIO6369 and Lacticaseibacillus rhamnosus BIO5326 induced a 30.6% and 38.4% reduction in the mesenchymal phenotype, respectively, caused a significant decrease in Snail and Zeb1 EMT marker expression and prevented the loss of tight junctions induced by H. pylori infection. A separate co-culture with a Boyden chamber maintained the effects induced by the two strains. H. pylori-induced IL-8 production was also significantly reduced in the presence of L. gasseri BIO6369 and L. rhamnosus BIO5326.Lactobacillus gasseri BIO6369 and L. rhamnosus BIO5326 strains decreased epithelial-to-mesenchymal transition and inflammation induced by H. pylori infection, suggesting that these species may have a protective effect against H. pylori-induced gastric carcinogenesis.CONCLUSIONLactobacillus gasseri BIO6369 and L. rhamnosus BIO5326 strains decreased epithelial-to-mesenchymal transition and inflammation induced by H. pylori infection, suggesting that these species may have a protective effect against H. pylori-induced gastric carcinogenesis.
A facilitated diffusion for glycerol is present in human erythrocytes. Glycerol transporters identified to date belong to
the M ajor I ntrinsic P rotein (MIP) family of integral membrane proteins, ...and one of them, aquaporin-3 (AQP3), has been characterized in mammals.
Using an antibody raised against a peptide corresponding to the rat AQP3 carboxyl terminus, we examined the presence of AQP3
in normal and Colton-null (aquaporin-1 (AQP1)-deficient) human erythrocytes. Three immunoreactive bands were detected on immunoblots
of both normal and Colton-null red cells, very similar to the bands revealed in rat kidney, a material in which AQP3 has been
extensively studied. By immunofluorescence, anti-AQP3 antibodies stained the plasma membranes of both normal and Colton-null
erythrocytes. Glycerol transport was measured on intact erythrocytes by stopped-flow light scattering and on one-step pink
ghosts by a rapid filtration technique. Glycerol permeability values, similar in both cell types, suggest that AQP1 does not
represent the major path for glycerol movement across red blood cell membranes. Furthermore, pharmacological studies showed
that Colton-null red cells remain sensitive to water and glycerol flux inhibitors, supporting the idea that another proteinaceous
path, probably AQP3, mediates most of the glycerol movements across red cell membranes and represents part of the residual
water transport activity found in AQP1-deficient red cells.
Gut microbiota is implicated in the control of host physiology by releasing bioactive actors that could exert a direct or indirect effect on tissue. A dysfunction of the gut microbiota to tissue axis ...could participate in the development of pathological states such as obesity and diabetes. The aim of this study was to identify the metabolic effect of
(known as
) BIO7251 (
BIO7251) isolated from Corsican clementine orange. Body weight gain, adiposity, glucose tolerance, glucose absorption and food intake were measured in mice fed a high-fat diet in response to a preventive oral administration of
BIO7251. This strain of bacteria exerts a beneficial effect on body weight gain by decreasing the subcutaneous adipose tissue mass. The treatment with
BIO7251 decreases glucose absorption and food intake in obese/diabetic mice.
BIO7251 could be tested as new probiotic strain that could manage body weight during obesity.
Biochemical and biophysical studies have shown that the strictly water-permeable aquaporins have a tetrameric structure, whereas results concerning the oligomeric state of GlpF, the glycerol ...facilitator of Escherichia coli, are dependent upon the analytical technique used. Here, we analyzed the oligomerization of the AQP3 aquaglyceroporin, which presents a mixed selectivity for water, glycerol, and urea. At first, based on transcript detection by reverse transcription-PCR from human erythroid tissues and membrane expression detected by flow cytometry analysis, we demonstrated that AQP3 is expressed on human and rat but not on mouse red blood cells. Then, the quaternary structure of AQP3 was determined using as models human red blood cell membranes, which carry both AQP1 and AQP3, and two heterologous expression systems:Xenopus laevis oocyte, for density and size estimation of aquaporins, and Saccharomyces cerevisiae yeast, which expressed a non-glycosylated form of AQP3. By velocity sedimentation in sucrose gradient after non-denaturing detergent solubilization, AQP3 was essentially found as mono- and dimeric species in conditions under which AQP1 preserved its tetrameric structure. Freeze-fracture studies on oocyte plasma membranes gave a size of AQP3 particles in favor of a dimeric or trimeric structure. Finally, by cross-linking experiments with red blood cell membranes, AQP3 is visible as different oligomeric structures, including a tetrameric one.
Helping neurons to compensate for proteotoxic stress and maintain function over time (neuronal compensation) has therapeutic potential in aging and neurodegenerative disease. The stress response ...factor FOXO3 is neuroprotective in models of Huntington’s disease (HD), Parkinson’s disease and motor-neuron diseases. Neuroprotective compounds acting in a FOXO-dependent manner could thus constitute bona fide drugs for promoting neuronal compensation. However, whether FOXO-dependent neuroprotection is a common feature of several compound families remains unknown. Using drug screening in C. elegans nematodes with neuronal expression of human exon-1 huntingtin (128Q), we found that 3ß-Methoxy-Pregnenolone (MAP4343), 17ß-oestradiol (17ßE2) and 12 flavonoids including isoquercitrin promote neuronal function in 128Q nematodes. MAP4343, 17ßE2 and isoquercitrin also promote stress resistance in mutant Htt striatal cells derived from knock-in HD mice. Interestingly, daf-16/FOXO is required for MAP4343, 17ßE2 and isoquercitrin to sustain neuronal function in 128Q nematodes. This similarly applies to the GSK3 inhibitor lithium chloride (LiCl) and, as previously described, to resveratrol and the AMPK activator metformin. Daf-16/FOXO and the targets engaged by these compounds define a sub-network enriched for stress-response and neuronally-active pathways. Collectively, these data highlights the dependence on a daf-16/FOXO-interaction network as a common feature of several compound families for prolonging neuronal function in HD.
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