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BACKGROUND/OBJECTIVES: To evaluate the short-term digestive tolerance and glycaemic response of several associations of maltitol and short-chain fructo-oligosaccharides (scFOS) used to replace sugars (for example, dextrose) in foods. SUBJECTS/METHODS: Thirty-six healthy subjects aged 18-60 years were recruited for the study and 32 completed it. The subjects consumed six different mixtures of dextrose, maltitol and scFOS added in a chocolate dairy dessert at a dosage of 35 g. The test days were separated by 2-week washout periods. The subjects reported the intensity of four individual gastrointestinal (GI) symptoms, number of bowel movements and stool frequency for the 48 h following consumption of the dessert. A subgroup of 18 subjects also provided blood samples 2 h after intake to evaluate the postprandial glycaemic and insulinaemic responses. RESULTS: The composite score calculated from the intensity of flatulence, borborygmi, bloating and discomfort was significantly higher (P < 0.0001) for all the desserts containing maltitol and/or scFOS than for the control dessert containing dextrose, but remains at the level of mild effects. The number of bowel movements was also slightly increased (P = 0.0006) and the stools were softer (P = 0.0045) for the first 24 h but not after (P =0.1373 and 0.5420, respectively). Blood glycaemic and insulinaemic responses were lower for all the sugar-free recipes containing maltitol and scFOS in comparison to the control one (P < 0.0001). CONCLUSIONS: This study has shown that maltitol and scFOS can be used jointly when formulating sugar-free foods with the benefit to lower postprandial glycaemic response with only a small and transient increase in non-serious GI symptoms. European Journal of Clinical Nutrition (2014) 68, 575-580; doi: 10.1038/ejcn.2014.30; published online 19 March 2014, INTRODUCTION Maltitol belongs to polyol family that are sugar-free sweeteners also called 'sugar alcohols', widely used in various foods either as sweetening agents in sugar-free foods or energy-reduced foods or [...]

Genetic variability and relationships among six native French cattle breeds (Abondance, Tarentaise, Villard de Lans, Montbeliarde, Limousin, and Charolais) and one foreign breed (Holstein) were investigated using 23 microsatellite markers. These breeds were also compared with four Swiss breeds genotyped in a previously published study. Interestingly, the French alpine breeds have smaller population sizes but showed higher genetic variability than the larger Holstein breed. Neighbor-joining trees and PCA (principal components analysis) showed that alpine breeds tend to cluster together. Abondance and Tarentaise breeds were closely related, whereas the Holstein was highly differentiated from all breeds analyzed. Two different assignment tests for determining the breed of origin of individuals were compared: 'direct' and 'exclusion-simulation' approaches. The exclusion-simulation significance test correctly assigns fewer individuals than the direct approach but provides a confidence level (e.g., P < 0.01) for each individual being assigned. Accurate assignment with high statistical confidence is required for animal traceability. Unfortunately, the accuracy of assignment greatly decreases as the threshold level of confidence of assignment increases (e.g., from P < 0.05 to P < 0.001). Assignment accuracy also greatly declines as the level of population differentiation decreases below the level often found between related breeds (e.g., [F.sub.ST] < 0.1). Key Words: Genetic Variation

Abstract HIV viruses encode a set of accessory proteins, which are important determinants of virulence due to their ability to manipulate the host cell physiology for the benefit of the virus. Although these viral proteins are dispensable for viral growth in many in vitro cell culture systems, they influence the efficiency of viral replication in certain cell types. Macrophages are early targets of HIV infection which play a major role in viral dissemination and persistence in the organism. This review focuses on two HIV accessory proteins whose functions might be more specifically related to macrophage infection: Vpr, which is conserved across primate lentiviruses including HIV-1 and HIV-2, and Vpx, a protein genetically related to Vpr, which is unique to HIV-2 and a subset of simian lentiviruses. Recent studies suggest that both Vpr and Vpx exploit the host ubiquitination machinery in order to inactivate specific cellular proteins. We review here why it remains difficult to decipher the role of Vpr in macrophage infection by HIV-1 and how recent data underscore the ability of Vpx to antagonize a restriction factor which counteracts synthesis of viral DNA in monocytic cells.

Background: Colorectal cancer (CRC) risk is strongly affected by dietary habits with red and processed meat increasing risk, and foods rich in dietary fibres considered protective. Dietary habits also shape gut microbiota, but the role of the combination between diet, the gut microbiota, and the metabolite profile on CRC risk is still missing an unequivocal characterisation., Methods: To investigate how gut microbiota affects diet-associated CRC risk, we fed Apc-mutated PIRC rats and azoxymethane (AOM)-induced rats the following diets: a high-risk red/processed meat-based diet (MBD), a normalised risk diet (MBD with α-tocopherol, MBDT), a low-risk pesco-vegetarian diet (PVD), and control diet. We then conducted faecal microbiota transplantation (FMT) from PIRC rats to germ-free rats treated with AOM and fed a standard diet for 3 months. We analysed multiple tumour markers and assessed the variations in the faecal microbiota using 16S rRNA gene sequencing together with targeted- and untargeted-metabolomics analyses., Results: In both animal models, the PVD group exhibited significantly lower colon tumorigenesis than the MBD ones, consistent with various CRC biomarkers. Faecal microbiota and its metabolites also revealed significant diet-dependent profiles. Intriguingly, when faeces from PIRC rats fed these diets were transplanted into germ-free rats, those transplanted with MBD faeces developed a higher number of preneoplastic lesions together with distinctive diet-related bacterial and metabolic profiles. PVD determines a selection of nine taxonomic markers mainly belonging to Lachnospiraceae and Prevotellaceae families exclusively associated with at least two different animal models, and within these, four taxonomic markers were shared across all the three animal models. An inverse correlation between nonconjugated bile acids and bacterial genera mainly belonging to the Lachnospiraceae and Prevotellaceae families (representative of the PVD group) was present, suggesting a potential mechanism of action for the protective effect of these genera against CRC., Conclusions: These results highlight the protective effects of PVD while reaffirming the carcinogenic properties of MBD diets. In germ-free rats, FMT induced changes reminiscent of dietary effects, including heightened preneoplastic lesions in MBD rats and the transmission of specific diet-related bacterial and metabolic profiles. Importantly, to the best of our knowledge, this is the first study showing that diet-associated cancer risk can be transferred with faeces, establishing gut microbiota as a determinant of diet-associated CRC risk. Therefore, this study marks the pioneering demonstration of faecal transfer as a means of conveying diet-related cancer risk, firmly establishing the gut microbiota as a pivotal factor in diet-associated CRC susceptibility. Video Abstract., (© 2024. The Author(s).)

Metagenome analyses of the human microbiome suggest that horizontal gene transfer (HGT) is frequent in these rich and complex microbial communities. However, so far, only a few HGT studies have been conducted in vivo . In this work, three different systems mimicking the physiological conditions encountered in the human digestive tract were tested, including (i) the TNO gastro-Intestinal tract Model 1 (TIM-1) system (for the upper part of the intestine), (ii) the ARtificial COLon (ARCOL) system (to mimic the colon), and (iii) a mouse model. To increase the likelihood of transfer by conjugation of the integrative and conjugative element studied in the artificial digestive systems, bacteria were entrapped in alginate, agar, and chitosan beads before being placed in the different gut compartments. The number of transconjugants detected decreased, while the complexity of the ecosystem increased (many clones in TIM-1 but only one clone in ARCOL). No clone was obtained in a natural digestive environment (germfree mouse model). In the human gut, the richness and diversity of the bacterial community would offer more opportunities for HGT events to occur. In addition, several factors (SOS-inducing agents, microbiota-derived factors) that potentially increase in vivo HGT efficiency were not tested here. Even if HGT events are rare, expansion of the transconjugant clones can happen if ecological success is fostered by selecting conditions or by events that destabilize the microbial community. IMPORTANCE The human gut microbiota plays a key role in maintaining normal host physiology and health, but its homeostasis is fragile. During their transit in the gastrointestinal tract, bacteria conveyed by food can exchange genes with resident bacteria. New traits acquired by HGT (e.g., new catabolic properties, bacteriocins, antibiotic resistance) can impact the gut microbial composition and metabolic potential. We showed here that TIM-1, a system mimicking the upper digestive tract, is a useful tool to evaluate HGT events in conditions closer to the physiological ones. Another important fact pointed out in this work is that Enterococcus faecalis is a good candidate for foreign gene acquisition. Due to its high ability to colonize the gut and acquire mobile genetic elements, this commensal bacterium could serve as an intermediate for HGT in the human gut., Competing Interests: The authors declare no conflict of interest.

Bacterial colonization in the gut plays a pivotal role in neonatal necrotizing enterocolitis (NEC) development, but the relationship between bacteria and NEC remains unclear. In this study, we aimed to elucidate whether bacterial butyrate end-fermentation metabolites participate in the development of NEC lesions and confirm the enteropathogenicity of Clostridium butyricum and Clostridium neonatale in NEC. First, we produced C.butyricum and C.neonatale strains impaired in butyrate production by genetically inactivating the hbd gene encoding β-hydroxybutyryl-CoA dehydrogenase that produces end-fermentation metabolites. Second, we evaluated the enteropathogenicty of the hbd-knockout strains in a gnotobiotic quail model of NEC. The analyses showed that animals harboring these strains had significantly fewer and less intense intestinal lesions than those harboring the respective wild-type strains. In the absence of specific biological markers of NEC, the data provide original and new mechanistic insights into the disease pathophysiology, a necessary step for developing potential novel therapies.

Background: Succinate is produced by both human cells and by gut bacteria and couples metabolism to inflammation as an extracellular signaling transducer. Circulating succinate is elevated in patients with obesity and type 2 diabetes and is linked to numerous complications, yet no studies have specifically addressed the contribution of gut microbiota to systemic succinate or explored the consequences of reducing intestinal succinate levels in this setting., Results: Using germ-free and microbiota-depleted mouse models, we show that the gut microbiota is a significant source of circulating succinate, which is elevated in obesity. We also show in vivo that therapeutic treatments with selected bacteria diminish the levels of circulating succinate in obese mice. Specifically, we demonstrate that Odoribacter laneus is a promising probiotic based on its ability to deplete succinate and improve glucose tolerance and the inflammatory profile in two independent models of obesity (db/db mice and diet-induced obese mice). Mechanistically, this is partly mediated by the succinate receptor 1. Supporting these preclinical findings, we demonstrate an inverse correlation between plasma and fecal levels of succinate in a cohort of patients with severe obesity. We also show that plasma succinate, which is associated with several components of metabolic syndrome including waist circumference, triglycerides, and uric acid, among others, is a primary determinant of insulin sensitivity evaluated by the euglycemic-hyperinsulinemic clamp., Conclusions: Overall, our work uncovers O. laneus as a promising next-generation probiotic to deplete succinate and improve glucose tolerance and obesity-related inflammation. Video Abstract., (© 2022. The Author(s).)

Infections of the central nervous system are among the most serious infections 1,2 , but the mechanisms by which pathogens access the brain remain poorly understood. The model microorganism Listeria monocytogenes (Lm) is a major foodborne pathogen that causes neurolisteriosis, one of the deadliest infections of the central nervous system 3,4 . Although immunosuppression is a well-established host risk factor for neurolisteriosis 3,5 , little is known about the bacterial factors that underlie the neuroinvasion of Lm. Here we develop a clinically relevant experimental model of neurolisteriosis, using hypervirulent neuroinvasive strains 6 inoculated in a humanized mouse model of infection 7 , and we show that the bacterial surface protein InlB protects infected monocytes from Fas-mediated cell death by CD8 + T cells in a manner that depends on c-Met, PI3 kinase and FLIP. This blockade of specific anti-Lm cellular immune killing lengthens the lifespan of infected monocytes, and thereby favours the transfer of Lm from infected monocytes to the brain. The intracellular niche that is created by InlB-mediated cell-autonomous immune resistance also promotes Lm faecal shedding, which accounts for the selection of InlB as a core virulence gene of Lm. We have uncovered a specific mechanism by which a bacterial pathogen confers an increased lifespan to the cells it infects by rendering them resistant to cell-mediated immunity. This promotes the persistence of Lm within the host, its dissemination to the central nervous system and its transmission., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Listeriolysin S (LLS) is a thiazole/oxazole-modified microcin (TOMM) produced by hypervirulent clones of Listeria monocytogenes LLS targets specific gram-positive bacteria and modulates the host intestinal microbiota composition. To characterize the mechanism of LLS transfer to target bacteria and its bactericidal function, we first investigated its subcellular distribution in LLS-producer bacteria. Using subcellular fractionation assays, transmission electron microscopy, and single-molecule superresolution microscopy, we identified that LLS remains associated with the bacterial cell membrane and cytoplasm and is not secreted to the bacterial extracellular space. Only living LLS-producer bacteria (and not purified LLS-positive bacterial membranes) display bactericidal activity. Applying transwell coculture systems and microfluidic-coupled microscopy, we determined that LLS requires direct contact between LLS-producer and -target bacteria in order to display bactericidal activity, and thus behaves as a contact-dependent bacteriocin. Contact-dependent exposure to LLS leads to permeabilization/depolarization of the target bacterial cell membrane and adenosine triphosphate (ATP) release. Additionally, we show that lipoteichoic acids (LTAs) can interact with LLS and that LTA decorations influence bacterial susceptibility to LLS. Overall, our results suggest that LLS is a TOMM that displays a contact-dependent inhibition mechanism., Competing Interests: The authors declare no competing interest., (Copyright © 2021 the Author(s). Published by PNAS.)

Background: Curcuminoids from turmeric rhizome have significant health benefits but low bioavailability., Objectives: To assess the pharmacokinetics of a novel natural turmeric dried colloidal suspension compared with 4 other turmeric formulations (including a standardized extract) at their respective recommended dosages., Methods: Thirty healthy men and women (18 to 45 y old) were enrolled in a randomized, open-labeled, crossover trial, and sequentially consumed single oral doses of standard turmeric extract (1500 mg), liquid micellar preparation (1000 mg), piperine-curcuminoid combination (1515 mg), phytosome formulation (1000 mg), or the dried colloidal suspension (300 mg). Eleven blood samples were obtained over 24 h, plasma was extracted with or without deconjugation with β-glucuronidase or sulfatase, and ultra-high-pressure liquid chromatography/tandem MS was used to quantify the 3 parent curcuminoids and 12 metabolites. Classical pharmacokinetics parameters were derived., Results: The total AUC values of unconjugated curcuminoids were highly variable within participants, with no significant differences between formulations. However, the AUC values for total curcuminoids (including all metabolites) showed significant product effects. Indeed, the micellar preparation delivered higher levels of total curcuminoids than any other formulation (8540 ng·h/mL), reaching significance when compared with the dried colloidal suspension and standard extract (6520 and 5080 ng·h/mL, respectively). After dose normalization, both micellar and dried colloidal formulations showed significantly higher AUC levels than the standard extract (respectively 136 and 72.9, compared with 3.7 ng·h/mL/mg). Total curcuminoid absorption levels were also significantly higher for the dried colloidal suspension when compared with either piperine or phytosome formulations. Interestingly, no significant differences were observed between the piperine-curcuminoid combination and the standard extract. No serious adverse events were reported., Conclusions: The administration of a low dose of the novel natural dried colloidal suspension provided high unconjugated and conjugated curcuminoid absorption, with significant beneficial differences when compared with the high dose of standard extract.This trial was registered at clinicaltrials.gov as NCT03621865., (© The Author(s) 2021. Published by Oxford University Press on behalf of the American Society for Nutrition.)

Cells infected with pathogens can contribute to clearing infections by releasing signals that instruct neighbouring cells to mount a pro-inflammatory cytokine response, or by other mechanisms that reduce bystander cells' susceptibility to infection. Here, we show the opposite effect: epithelial cells infected with Salmonella Typhimurium secrete host factors that facilitate the infection of bystander cells. We find that the endoplasmic reticulum stress response is activated in both infected and bystander cells, and this leads to activation of JNK pathway, downregulation of transcription factor E2F1, and consequent reprogramming of microRNA expression in a time-dependent manner. These changes are not elicited by infection with other bacterial pathogens, such as Shigella flexneri or Listeria monocytogenes. Remarkably, the protein HMGB1 present in the secretome of Salmonella-infected cells is responsible for the activation of the IRE1 branch of the endoplasmic reticulum stress response in non-infected, neighbouring cells. Furthermore, E2F1 downregulation and the associated microRNA alterations promote Salmonella replication within infected cells and prime bystander cells for more efficient infection.

Listeria monocytogenes (Lm) is a foodborne bacterial pathogen that causes listeriosis, a severe infection that manifests as bacteremia and meningo-encephalitis mostly in immunocompromised individuals, and maternal-fetal infection. A critical pathogenic determinant of Lm relies on its ability to actively cross the intestinal barrier, disseminate systemically and cross the blood-brain and placental barriers. Here we illustrate how Lm both evades innate immunity, favoring its dissemination in host tissues, and triggers innate immune defenses that participate to its control., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

MicroRNAs (miRNAs) are increasingly recognized for their role in infection by bacterial pathogens, although the effect of each individual miRNA remains largely unknown. Here, we used a comparative genome-wide microscopy-based functional screening approach to identify miRNAs controlling infection by two bacterial pathogens-Salmonella enterica serovar Typhimurium and Shigella flexneri. Despite the similarities between these pathogens, we found infections to be controlled by largely non-overlapping subsets of miRNAs, seemingly reflecting different requirements prompted by their distinct intracellular lifestyles. By characterizing a small subset of miRNAs chosen among the strongest inhibitors of Shigella infection, we discovered that miR-3668, miR-4732-5p and miR-6073 exert a selective effect on Shigella infection by impairing bacterial actin-based motility by downregulating N-WASP. Additionally, by identifying let-7i-3p miRNA as a strong inhibitor of Salmonella replication and performing in-depth analysis of its mechanisms of action, we showed that this miRNA specifically inhibits Salmonella infection via modulation of endolysosomal trafficking and the vacuolar environment by targeting the host RGS2 protein. These findings illustrate two paradigms underlying miRNA-mediated regulation of bacterial infection, acting as part of the host response to infection, or as part of bacterial strategies to modulate the host environment and favour pathogenesis.

MicroRNAs play an important role in the interplay between bacterial pathogens and host cells, participating as host defense mechanisms, as well as exploited by bacteria to subvert host cellular functions. Here, we show that microRNAs modulate infection by Shigella flexneri, a major causative agent of bacillary dysentery in humans. Specifically, we characterize the dual regulatory role of miR-29b-2-5p during infection, showing that this microRNA strongly favors Shigella infection by promoting both bacterial binding to host cells and intracellular replication. Using a combination of transcriptome analysis and targeted high-content RNAi screening, we identify UNC5C as a direct target of miR-29b-2-5p and show its pivotal role in the modulation of Shigella binding to host cells. MiR-29b-2-5p, through repression of UNC5C, strongly enhances filopodia formation thus increasing Shigella capture and promoting bacterial invasion. The increase of filopodia formation mediated by miR-29b-2-5p is dependent on RhoF and Cdc42 Rho-GTPases. Interestingly, the levels of miR-29b-2-5p, but not of other mature microRNAs from the same precursor, are decreased upon Shigella replication at late times post-infection, through degradation of the mature microRNA by the exonuclease PNPT1. While the relatively high basal levels of miR-29b-2-5p at the start of infection ensure efficient Shigella capture by host cell filopodia, dampening of miR-29b-2-5p levels later during infection may constitute a bacterial strategy to favor a balanced intracellular replication to avoid premature cell death and favor dissemination to neighboring cells, or alternatively, part of the host response to counteract Shigella infection. Overall, these findings reveal a previously unappreciated role of microRNAs, and in particular miR-29b-2-5p, in the interaction of Shigella with host cells.

Background: Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder characterized by recurrent abdominal pain and/or discomfort. Probiotics have been reported to benefit IBS symptoms but the level of benefit remains quite unclear., Objective: This study was designed to assess the benefit of Saccharomyces cerevisiae I-3856 on IBS symptoms., Methods: A randomized, double blind, placebo-controlled trial has been performed in 379 subjects with diagnosed IBS. Subjects were randomly supplemented with the probiotics (1000 mg) or placebo for 12 weeks. Questionnaires (gastrointestinal symptoms, stools, wellbeing, and quality of life) were completed. Primary endpoint was percentage of responders defined as having a 50% decrease in the weekly average "intestinal pain/discomfort score" for at least 4 out of the last 8 weeks of the study., Results: There was no overall benefit of S. cerevisiae I-3856 on IBS symptoms and wellbeing in the study population. Moreover, S. cerevisiae I-3856 was not statistically significant predictor of the responder status of the subjects (p > 0.05). Planned subgroup analyses showed significant effect in the IBS-C subjects: improvement of gastrointestinal symptoms was significantly higher in active group, compared to placebo, on abdominal pain/discomfort and bloating throughout the study and at the end of the supplementation., Conclusions: In this study, S. cerevisiae I-3856 at the dose of 1000 mg per day does not improve intestinal pain and discomfort in general IBS patients. However, it seems to have an effect in the subgroup with constipation which needs further studies to confirm (NCT01613456 in ClinicalTrials.gov registry).

Background: Bacillus probiotics health benefits have been until now quite poorly studied in the elderly population. This study aimed to assess the effects of Bacillus subtilis CU1 consumption on immune stimulation and resistance to common infectious disease (CID) episodes in healthy free-living seniors., Results: One hundred subjects aged 60-74 were included in this randomized, double-blind, placebo-controlled, parallel-arms study. Subjects consumed either the placebo or the probiotic (2.10(9) B. subtilis CU1 spores daily) by short periodical courses of 10 days intermittently, alternating 18-day course of break. This scheme was repeated 4 times during the study. Symptoms of gastrointestinal and upper/lower respiratory tract infections were recorded daily by the subjects throughout the study (4 months). Blood, saliva and stool samples were collected in a predefined subset of the first forty-four subjects enrolled in the study. B. subtilis CU1 supplementation did not statistically significantly decrease the mean number of days of reported CID symptoms over the 4-month of study (probiotic group: 5.1 (7.0) d, placebo group: 6.6 (7.3) d, P = 0.2015). However, in the subset of forty-four randomized subjects providing biological samples, we showed that consumption of B. subtilis CU1 significantly increased fecal and salivary secretory IgA concentrations compared to the placebo. A post-hoc analysis on this subset showed a decreased frequency of respiratory infections in the probiotc group compared to the placebo group., Conclusion: Taken together, our study provides evidence that B. subtilis CU1 supplementation during the winter period may be a safe effective way to stimulate immune responses in elderly subjects.

Scope: Silicon (Si) is an abundant element on earth. It is found naturally in water in the form of orthosilicic acid (OSA), however this form is not stable under certain conditions such as in highly concentrated and non-neutral pH solutions, which lead to its polymerization and reduced bioavailability. This study aimed to assess the bioavailability of Si from OSA stabilized by vanillin (OSA-VC)., Methods and Results: This was a single-center, double-blind, cross-over randomized controlled trial. Fourteen healthy subjects were recruited and consumed either OSA-VC or a placebo on two separate occasions. Blood and urine samples were collected during 6 h following ingestion and analyzed to determine Si absorption and excretion. Plasma Si area under the curve (0-6 h) was significantly higher after OSA-VC ingestion compared to placebo ingestion (p = 0.0002). Significantly higher urinary Si excretion was also reported over the 6-h period after OSA-VC ingestion compared to placebo (p<0.0001). Approximately 21% of ingested Si was excreted in urine during this period., Conclusion: Although many studies have investigated the metabolism and bioavailability of Si supplemented in foods or as a food ingredient, this was the first to investigate and demonstrate the digestibility of OSA administered in a complex form with vanillin., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

MicroRNAs (miRNAs) are small non-coding RNAs with a central role in the post-transcriptional control of gene expression, that have been implicated in a wide-range of biological processes. Regulation of miRNA expression is increasingly recognized as a crucial part of the host response to infection by bacterial pathogens, as well as a novel molecular strategy exploited by bacteria to manipulate host cell pathways. Here, we review the current knowledge of bacterial pathogens that modulate host miRNA expression, focusing on mammalian host cells, and the implications of miRNA regulation on the outcome of infection. The emerging role of commensal bacteria, as part of the gut microbiota, on host miRNA expression in the presence or absence of bacterial pathogens is also discussed., (Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)

Increasing evidence suggests an important role for miRNAs in the molecular interplay between bacterial pathogens and host cells. Here we perform a fluorescence microscopy-based screen using a library of miRNA mimics and demonstrate that miRNAs modulate Salmonella infection. Several members of the miR-15 miRNA family were among the 17 miRNAs that more efficiently inhibit Salmonella infection. We discovered that these miRNAs are downregulated during Salmonella infection, through the inhibition of the transcription factor E2F1. Analysis of miR-15 family targets revealed that derepression of cyclin D1 and the consequent promotion of G1/S transition are crucial for Salmonella intracellular proliferation. In addition, Salmonella induces G2/M cell cycle arrest in infected cells, further promoting its replication. Overall, these findings uncover a mechanism whereby Salmonella renders host cells more susceptible to infection by controlling cell cycle progression through the active modulation of host cell miRNAs.

Purpose: To determine the effect of 4 weeks of supplementation, then, withdrawal of a dietary supplement (DS) containing red yeast rice extract, policosanol and artichoke leaf extract at twice the recommended daily dose (6 tablets, 6-TAB) compared to the usual dose (3-TAB) or to a placebo (PLA), on blood lipid profiles and safety biomarkers., Methods: Forty-five healthy subjects (15 per group), with untreated hypercholesterolaemia, were included in this randomised, double-blind, placebo-controlled clinical trial., Results: After 4 weeks of supplementation, LDL-C was significantly lower in 6-TAB (-0.21 g/l; 95 % CI -0.38 to -0.03 g/l; p = 0.0217) and 3-TAB (-0.25 g/l; 95 % CI -0.42 to -0.07 g/l; p = 0.0071) compared to PLA, although no difference in LDL-cholesterol was observed between the two groups, while no effect was seen on triacylglycerol and HDL-cholesterol. Four weeks after the end of supplementation, no difference in LDL-C was seen between the PLA group and the DS-treated groups. The muscle breakdown biomarkers, as well as biomarkers of liver and renal function, were altered by neither dose of the DS. Acute application of the DS on permeabilised skeletal muscle fibres of rats did not induce deleterious effects on mitochondrial function., Conclusions: Supplementation with twice the recommended dose of the DS was effective in reducing LDL-cholesterol and appeared safe, but according to the present results, no additional benefit could be achieved compared to the recommended dose.

Objective: To investigate the effect of a natural cholesterol-lowering supplement (NCLS) containing red yeast rice, policosanols and artichoke leaf extracts on blood lipid concentrations as well as on safety parameters when given over 16 weeks in 100 volunteers with untreated moderate hypercholesterolemia, in a randomized, double-blind, placebo-controlled trial., Results: Reduction of primary outcome low-density lipoprotein cholesterol [-0.22 g/L (95% confidence interval, CI: -0.31 to -0.12) corresponding to -14.3% from baseline (95% CI: -21.5 to -7.2) compared to placebo], as well as total cholesterol, apolipoprotein B100 and apolipoprotein B100/apolipoprotein A-I ratio, were observed after 16 weeks of supplementation with NCLS. These effects were already observed at Week 4 and 10 of supplementation. No significant changes were observed in high-density lipoprotein, triacylglycerol, creatine kinase, lactate dehydrogenase and coenzyme Q10 levels, as well as in markers of liver and renal function., Conclusions: The NCLS was effective in reducing low-density lipoprotein cholesterol and apolipoprotein B100 in subjects with moderate hypercholesterolemia, without modifying safety parameters.

The Vpr protein from type 1 and type 2 Human Immunodeficiency Viruses (HIV-1 and HIV-2) is thought to inactivate several host proteins through the hijacking of the DCAF1 adaptor of the Cul4A ubiquitin ligase. Here, we identified two transcriptional regulators, ZIP and sZIP, as Vpr-binding proteins degraded in the presence of Vpr. ZIP and sZIP have been shown to act through the recruitment of the NuRD chromatin remodeling complex. Strikingly, chromatin is the only cellular fraction where Vpr is present together with Cul4A ubiquitin ligase subunits. Components of the NuRD complex and exogenous ZIP and sZIP were also associated with this fraction. Several lines of evidence indicate that Vpr induces ZIP and sZIP degradation by hijacking DCAF1: (i) Vpr induced a drastic decrease of exogenously expressed ZIP and sZIP in a dose-dependent manner, (ii) this decrease relied on the proteasome activity, (iii) ZIP or sZIP degradation was impaired in the presence of a DCAF1-binding deficient Vpr mutant or when DCAF1 expression was silenced. Vpr-mediated ZIP and sZIP degradation did not correlate with the growth-related Vpr activities, namely G2 arrest and G2 arrest-independent cytotoxicity. Nonetheless, infection with HIV-1 viruses expressing Vpr led to the degradation of the two proteins. Altogether our results highlight the existence of two host transcription factors inactivated by Vpr. The role of Vpr-mediated ZIP and sZIP degradation in the HIV-1 replication cycle remains to be deciphered.

SAMHD1 restricts the infection of dendritic and other myeloid cells by human immunodeficiency virus type 1 (HIV-1), but in lentiviruses of the simian immunodeficiency virus of sooty mangabey (SIVsm)-HIV-2 lineage, SAMHD1 is counteracted by the virion-packaged accessory protein Vpx. Here we found that SAMHD1 restricted infection by hydrolyzing intracellular deoxynucleoside triphosphates (dNTPs), lowering their concentrations to below those required for the synthesis of the viral DNA by reverse transcriptase (RT). SAMHD1-mediated restriction was alleviated by the addition of exogenous deoxynucleosides. An HIV-1 with a mutant RT with low affinity for dNTPs was particularly sensitive to SAMHD1-mediated restriction. Vpx prevented the SAMHD1-mediated decrease in dNTP concentration and induced the degradation of human and rhesus macaque SAMHD1 but had no effect on mouse SAMHD1. Nucleotide-pool depletion could be a general mechanism for protecting cells from infectious agents that replicate through a DNA intermediate.

Vpr, a small HIV auxiliary protein, hijacks the CUL4 ubiquitin ligase through DCAF1 to inactivate an unknown cellular target, leading to cell cycle arrest at the G(2) phase and cell death. Here we first sought to delineate the Vpr determinants involved in the binding to DCAF1 and to the target. On the one hand, the three α-helices of Vpr are necessary and sufficient for binding to DCAF1; on the other hand, nonlinear determinants in Vpr are required for binding to the target, as shown by using protein chimeras. We also underscore that a SRIG motif conserved in the C-terminal tail of Vpr proteins from HIV-1/SIVcpz and HIV-2/SIVsmm lineages is critical for G(2) arrest. Our results suggest that this motif may be predictive of the ability of Vpr proteins from other SIV lineages to mediate G(2) arrest. We took advantage of the characterization of a subset of G(2) arrest-defective, but DCAF1 binding-proficient mutants, to investigate whether Vpr interferes with cell viability independently of its ability to induce G(2) arrest. These mutants inhibited cell colony formation in HeLa cells and are cytotoxic in lymphocytes, unmasking a G(2) arrest-independent cytopathic effect of Vpr. Furthermore these mutants do not block cell cycle progression at the G(1) or S phases but trigger apoptosis through caspase 3. Disruption of DCAF1 binding restored efficiency of colony formation. However, DCAF1 binding per se is not sufficient to confer cytopathicity. These data support a model in which Vpr recruits DCAF1 to induce the degradation of two host proteins independently required for proper cell growth.

HIV viruses encode a set of accessory proteins, which are important determinants of virulence due to their ability to manipulate the host cell physiology for the benefit of the virus. Although these viral proteins are dispensable for viral growth in many in vitro cell culture systems, they influence the efficiency of viral replication in certain cell types. Macrophages are early targets of HIV infection which play a major role in viral dissemination and persistence in the organism. This review focuses on two HIV accessory proteins whose functions might be more specifically related to macrophage infection: Vpr, which is conserved across primate lentiviruses including HIV-1 and HIV-2, and Vpx, a protein genetically related to Vpr, which is unique to HIV-2 and a subset of simian lentiviruses. Recent studies suggest that both Vpr and Vpx exploit the host ubiquitination machinery in order to inactivate specific cellular proteins. We review here why it remains difficult to decipher the role of Vpr in macrophage infection by HIV-1 and how recent data underscore the ability of Vpx to antagonize a restriction factor which counteracts synthesis of viral DNA in monocytic cells.

The need for accurate and reliable methods for animal species identification has steadily increased during past decades, particularly with the recent food scares and the overall crisis of biodiversity primarily resulting from the huge ongoing illegal traffic of endangered species. A relatively new biotechnological field, known as species molecular identification, based on the amplification and analysis of DNA, offers promising solutions. Indeed, despite the fact that retrieval and analysis of DNA in processed products is a real challenge, numerous technically consistent methods are now available and allow the detection of animal species in almost any organic substrate. However, this field is currently facing a turning point and should rely more on knowledge primarily from three fundamental fields--paleogenetics, molecular evolution and systematics.

This study was carried out in the French county of Nièvre after the establishment of a new state funded grant for elderly people called the Autonomy Adapted Allocation. The study looks at the medical evaluations conducted in the homes of elderly people aged 60 and over who have submitted a request for this new grant (a total of 2388 requests were received). The study points to a high level of dependence within the target population of those who are "susceptible to dementia". It also demonstrated that the current scale used for identifying those who are susceptible to dementia is insufficient for its purpose in this case, and unfortunately it lacks the ability to include a portion of the population who should be considered as recipients of these funds. This gap corroborates the difficulty in fully appreciating and understanding the functional repercussions of dementia.

A new polymerase chain reaction (PCR)-based method was developed to detect cows milk in goat cheese. This method is based on mitochondrial DNA (mtDNA) control region sequence variations. DNA extractions from 150 mg of cheese were carried out using a spin column-based method. Subsequent PCR amplifications of DNA were performed with cow specific primers, demonstrating the ability to detect cows' milk in a variety of cheeses. This simple approach provides high quality DNA, and is shown to be very sensitive, with a detection limit of less than 0.1% of cows' milk. Analysis of an agarose gel digital image allows a rough estimation of the percentage of cows' milk used in adulteration.