Project description:It has been proposed that endogenously formed N-nitroso compounds (NOCs) are partly responsible for the link between red meat consumption and colorectal cancer (CRC) risk. As nitrite has been indicated as one of the critical factors in the formation of endogenous NOCs, it is of high importance to replace or reduce the nitrite levels in meat. Therefore, the PHYTOME project was initiated (Phytochemicals to reduce nitrite in meat products; www.phytome.eu), an EU funded research project aiming to develop innovative meat products in which the food additive sodium nitrite (E251) has been replaced by natural compounds originating from fruits and vegetables. A human dietary intervention study was conducted in which healthy subjects consumed 300 grams of meat for two weeks, in subsequent order: normal processed red meat, white meat, and red processed meat with standard or reduced levels of nitrite and added phytochemicals. Consumption of standard-nitrite PHYTOME meat products leads to a significant reduction in Apparent Total N-nitroso Compounds (ATNC) levels in faecal water, a surrogate marker of endogenously formed NOCs, as compared to the consumption of conventional processed red meat products. A reduction of nitrite in the PHYTOME meat lowered these levels even further. In addition, DNA strand breaks induced in ex-vivo faecal water exposed Caco-2 cells and O6-methyl-guanine adducts levels in colonic DNA were significantly higher after consumption of normal processed red meat as compared to white meat intake. PHYTOME meat intake resulted in reduced levels of these genotoxic markers, however, these were not statistically significant. Whole genome gene expression analyses in colonic tissue identified differentially expressed genes and genes associated with ATNC, which are related to molecular pathways which may explain cancer risk initiation after intake of processed red meat and cancer risk prevention after intake of the PHYTOME meat. Together these results indicate that addition of natural extracts to conventional processed red meat products results in reduced endogenous formation of NOCs, and may therefore contribute to a reduced risk of CRC, which is mechanistically supported by gene expression analyses.
Project description:Livestock farming and conventional meat production pose significant environmental, health, and animal welfare challenges. In seeking sustainable alternative solutions, cultivated meat technology typically utilizes differentiation of myogenic progenitor cells (MPCs) into muscle cells for in vitro meat production. However, understanding the molecular determinants governing MPC differentiation into muscle cells, and the potential enhancement of this process through modulation of signaling pathways, remains limited. Herein, we characterized the molecular landscape associated with bovine MPC differentiation in vitro by employing multiomics, and explored its augmentation by small molecules, together leading to identification of media that enhanced myogenic differentiation compared with conventional methods in both 2D cultures and tissue‐engineered 3D skeletal muscle constructs. Through bulk and single‐cell transcriptomics and proteomics, we compared conventional and enhanced differentiation media, demonstrating that the enhanced media gave rise to unique progenitor‐like cell populations, while simultaneously promoting differentiation into myocytes and contractile myotubes expressing a wide array of myogenic markers that more closely resemble bovine muscle cells in vivo. The improved method for promoting myogenic differentiation in 2D and 3D formats, together with the corresponding molecular roadmap, may prove valuable for cultivated meat applications.
Project description:The inappropriate use of antibiotics is a severe public health problem worldwide, contributing to the emergence of multidrug-resistant (MDR) bacteria. To explore the possible impacts of the inappropriate use of antibiotics on the immune system, we use Klebsiella pneumoniae (K. pneumoniae) infection as an example and show that imipenem increases the mortality of mice infected by MDR K. pneumoniae. Further studies demonstrate that imipenem enhances the secretion of outer membrane vesicles (OMVs) with significantly elevated presentation of GroEL, which promotes the phagocytosis of OMVs by macrophages that depends on the interaction between GroEL and its receptor LOX-1. OMVs cause the pyroptosis of macrophages and the release of proinflammatory cytokines, which contribute to exacerbated inflammatory responses. We propose that the inappropriate use of antibiotics in the cases of infection by MDR bacteria such as K. pneumoniae might cause damaging inflammatory responses, which underlines the pernicious effects of inappropriate use of antibiotic.
Project description:This study elucidates the whole proteome changes in the MDR isolates of K. penumoniae, A. baumannii, E. coli, and P. aeruginiosa in the presence of Ampicillin, Kanamycin, and Nalidixic acid. Label-free SWATH-MS is used for protein quantitation of antibiotics treated and untreated samples.
Project description:The acquisition of multi-drug resistance (MDR) determinants jeopardizes treatment of bacterial infections with antibiotics. The tripartite efflux pump AcrAB-NodT confers adaptive MDR in the non-pathogenic α-proteobacterium Caulobacter crescentus via transcriptional induction by first-generation quinolone antibiotics. We discovered that overexpression of AcrAB-NodT by mutation or exogenous inducers confers resistance to cephalosporin and penicillin (β-lactam) antibiotics. Combining two-step mutagenesis-sequencing (Mut-Seq) and cephalosporin-resistant point mutants, we dissected how TipR targets a common operator of divergent tipR and acrAB-nodT promoter in adaptive and/or potentiated AcrAB-NodT-directed efflux. Chemical screening identified compounds that either interfere with DNA-binding by TipR or induce its ClpXP-dependent proteolytic turnover. We found that long-term induction of AcrAB-NodT disfigures the envelope and that homeostatic control by TipR includes co-induction of the DnaJ-like co-chaperone DjlA, to boost pump assembly and/or capacity in anticipation of envelope stress. Thus, the adaptive MDR regulatory circuitry reconciles drug efflux with co-chaperone function for trans-envelope assemblies and maintenance.
Project description:The acquisition of multi-drug resistance (MDR) determinants jeopardizes treatment of bacterial infections with antibiotics. The tripartite efflux pump AcrAB-NodT confers adaptive MDR in the non-pathogenic α-proteobacterium Caulobacter crescentus via transcriptional induction by first-generation quinolone antibiotics. We discovered that overexpression of AcrAB-NodT by mutation or exogenous inducers confers resistance to cephalosporin and penicillin (β-lactam) antibiotics. Combining two-step mutagenesis-sequencing (Mut-Seq) and cephalosporin-resistant point mutants, we dissected how TipR targets a common operator of divergent tipR and acrAB-nodT promoter in adaptive and/or potentiated AcrAB-NodT-directed efflux. Chemical screening identified compounds that either interfere with DNA-binding by TipR or induce its ClpXP-dependent proteolytic turnover. We found that long-term induction of AcrAB-NodT disfigures the envelope and that homeostatic control by TipR includes co-induction of the DnaJ-like co-chaperone DjlA, to boost pump assembly and/or capacity in anticipation of envelope stress. Thus, the adaptive MDR regulatory circuitry reconciles drug efflux with co-chaperone function for trans-envelope assemblies and maintenance.
Project description:The acquisition of multi-drug resistance (MDR) determinants jeopardizes treatment of bacterial infections with antibiotics. The tripartite efflux pump AcrAB-NodT confers adaptive MDR in the non-pathogenic α-proteobacterium Caulobacter crescentus via transcriptional induction by first-generation quinolone antibiotics. We discovered that overexpression of AcrAB-NodT by mutation or exogenous inducers confers resistance to cephalosporin and penicillin (β-lactam) antibiotics. Combining two-step mutagenesis-sequencing (Mut-Seq) and cephalosporin-resistant point mutants, we dissected how TipR targets a common operator of divergent tipR and acrAB-nodT promoter in adaptive and/or potentiated AcrAB-NodT-directed efflux. Chemical screening identified compounds that either interfere with DNA-binding by TipR or induce its ClpXP-dependent proteolytic turnover. We found that long-term induction of AcrAB-NodT disfigures the envelope and that homeostatic control by TipR includes co-induction of the DnaJ-like co-chaperone DjlA, to boost pump assembly and/or capacity in anticipation of envelope stress. Thus, the adaptive MDR regulatory circuitry reconciles drug efflux with co-chaperone function for trans-envelope assemblies and maintenance.
Project description:The present work aimed to compare the transcriptome of three major ethanol-producer Saccharomyces cerevisiae strains in Brazil when fermenting sugarcane juice for fuel ethanol production. This was motivated by the reports presenting physiological and genomics differences among them, and by the attempt to identify genes that could be related to their fermentation capacity and adaptation for different industrial processes.