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Nature Jan 2023Animals display substantial inter-species variation in the rate of embryonic development despite a broad conservation of the overall sequence of developmental events.... (Comparative Study)
Comparative Study
Animals display substantial inter-species variation in the rate of embryonic development despite a broad conservation of the overall sequence of developmental events. Differences in biochemical reaction rates, including the rates of protein production and degradation, are thought to be responsible for species-specific rates of development. However, the cause of differential biochemical reaction rates between species remains unknown. Here, using pluripotent stem cells, we have established an in vitro system that recapitulates the twofold difference in developmental rate between mouse and human embryos. This system provides a quantitative measure of developmental speed as revealed by the period of the segmentation clock, a molecular oscillator associated with the rhythmic production of vertebral precursors. Using this system, we show that mass-specific metabolic rates scale with the developmental rate and are therefore higher in mouse cells than in human cells. Reducing these metabolic rates by inhibiting the electron transport chain slowed down the segmentation clock by impairing the cellular NAD/NADH redox balance and, further downstream, lowering the global rate of protein synthesis. Conversely, increasing the NAD/NADH ratio in human cells by overexpression of the Lactobacillus brevis NADH oxidase LbNOX increased the translation rate and accelerated the segmentation clock. These findings represent a starting point for the manipulation of developmental rate, with multiple translational applications including accelerating the differentiation of human pluripotent stem cells for disease modelling and cell-based therapies.
Topics: Animals; Humans; Mice; Cell Differentiation; Embryonic Development; NAD; Oxidation-Reduction; Pluripotent Stem Cells; Species Specificity; In Vitro Techniques; Electron Transport; Biological Clocks; Time Factors; Embryo, Mammalian; Levilactobacillus brevis
PubMed: 36599986
DOI: 10.1038/s41586-022-05574-4 -
Nature Sep 2020The mitochondrial electron transport chain (ETC) is necessary for tumour growth and its inhibition has demonstrated anti-tumour efficacy in combination with targeted...
The mitochondrial electron transport chain (ETC) is necessary for tumour growth and its inhibition has demonstrated anti-tumour efficacy in combination with targeted therapies. Furthermore, human brain and lung tumours display robust glucose oxidation by mitochondria. However, it is unclear why a functional ETC is necessary for tumour growth in vivo. ETC function is coupled to the generation of ATP-that is, oxidative phosphorylation and the production of metabolites by the tricarboxylic acid (TCA) cycle. Mitochondrial complexes I and II donate electrons to ubiquinone, resulting in the generation of ubiquinol and the regeneration of the NAD+ and FAD cofactors, and complex III oxidizes ubiquinol back to ubiquinone, which also serves as an electron acceptor for dihydroorotate dehydrogenase (DHODH)-an enzyme necessary for de novo pyrimidine synthesis. Here we show impaired tumour growth in cancer cells that lack mitochondrial complex III. This phenotype was rescued by ectopic expression of Ciona intestinalis alternative oxidase (AOX), which also oxidizes ubiquinol to ubiquinone. Loss of mitochondrial complex I, II or DHODH diminished the tumour growth of AOX-expressing cancer cells deficient in mitochondrial complex III, which highlights the necessity of ubiquinone as an electron acceptor for tumour growth. Cancer cells that lack mitochondrial complex III but can regenerate NAD+ by expression of the NADH oxidase from Lactobacillus brevis (LbNOX) targeted to the mitochondria or cytosol were still unable to grow tumours. This suggests that regeneration of NAD+ is not sufficient to drive tumour growth in vivo. Collectively, our findings indicate that tumour growth requires the ETC to oxidize ubiquinol, which is essential to drive the oxidative TCA cycle and DHODH activity.
Topics: Animals; Cell Line, Tumor; Cell Proliferation; Ciona intestinalis; Citric Acid Cycle; Cytosol; Dihydroorotate Dehydrogenase; Electron Transport; Electron Transport Complex I; Electron Transport Complex II; Electron Transport Complex III; Humans; Levilactobacillus brevis; Male; Mice; Mitochondria; Mitochondrial Proteins; Multienzyme Complexes; NAD; NADH, NADPH Oxidoreductases; Neoplasms; Oxidative Phosphorylation; Oxidoreductases; Oxidoreductases Acting on CH-CH Group Donors; Plant Proteins; Ubiquinone
PubMed: 32641834
DOI: 10.1038/s41586-020-2475-6 -
Journal of Applied Microbiology Aug 2012To assess the ability of human intestinally derived strains of Lactobacillus and Bifidobacterium to produce γ-aminobutyric acid (GABA).
AIMS
To assess the ability of human intestinally derived strains of Lactobacillus and Bifidobacterium to produce γ-aminobutyric acid (GABA).
METHODS AND RESULTS
Strains of Lactobacillus and Bifidobacterium were grown in medium containing monosodium glutamate (MSG). Growth of the bacteria and conversion of MSG to GABA were measured. Of 91 intestinally derived bacteria assessed, one Lactobacillus strain and four strains of Bifidobacterium produced GABA. Lactobacillus brevis DPC6108 was the most efficient of the strains tested, converting up to 90% [corrected] of MSG to GABA. The ability of the cultured intestinal strains to produce GABA was investigated using a simple pH-controlled anaerobic faeces-based fermentation, supplemented with 30 mg ml⁻¹ MSG. The addition of Lact. brevis DPC6108 to a faeces-based fermentation significantly increased the GABA concentration (P < 0·001), supporting the notion that this biosynthesis could occur in vivo.
CONCLUSIONS
The production of GABA by bifidobacteria exhibited considerable interspecies variation. Lactobacillus brevis and Bifidobacterium dentium were the most efficient GABA producers among the range of strains tested. The addition of Lact. brevis DPC6108 to the culturable gut microbiota increased the GABA concentration in fermented faecal slurry at physiological pH.
SIGNIFICANCE AND IMPACT OF THE STUDY
Identification of optimal MSG conversion to GABA by particular cultured elements of the commensal intestinal microbiota and the demonstration that this can occur under simulated in vivo conditions offer new prospects for microbiota modulation to promote health.
Topics: Bifidobacterium; Culture Media; Feces; Fermentation; Humans; Hydrogen-Ion Concentration; Intestines; Levilactobacillus brevis; Sodium Glutamate; gamma-Aminobutyric Acid
PubMed: 22612585
DOI: 10.1111/j.1365-2672.2012.05344.x -
Science (New York, N.Y.) Apr 2016A decline in electron transport chain (ETC) activity is associated with many human diseases. Although diminished mitochondrial adenosine triphosphate production is...
A decline in electron transport chain (ETC) activity is associated with many human diseases. Although diminished mitochondrial adenosine triphosphate production is recognized as a source of pathology, the contribution of the associated reduction in the ratio of the amount of oxidized nicotinamide adenine dinucleotide (NAD(+)) to that of its reduced form (NADH) is less clear. We used a water-forming NADH oxidase from Lactobacillus brevis (LbNOX) as a genetic tool for inducing a compartment-specific increase of the NAD(+)/NADH ratio in human cells. We used LbNOX to demonstrate the dependence of key metabolic fluxes, gluconeogenesis, and signaling on the cytosolic or mitochondrial NAD(+)/NADH ratios. Expression of LbNOX in the cytosol or mitochondria ameliorated proliferative and metabolic defects caused by an impaired ETC. The results underscore the role of reductive stress in mitochondrial pathogenesis and demonstrate the utility of targeted LbNOX for direct, compartment-specific manipulation of redox state.
Topics: Catalysis; Cytosol; Electron Transport; Electron Transport Chain Complex Proteins; Genetic Complementation Test; Gluconeogenesis; HeLa Cells; Humans; Levilactobacillus brevis; Mitochondria; Mitochondrial Diseases; Multienzyme Complexes; NAD; NADH, NADPH Oxidoreductases; Oxidation-Reduction
PubMed: 27124460
DOI: 10.1126/science.aad4017 -
Journal of Microbiology and... Jan 2022This study aims to determine the antibiofilm effect of cell-free supernatant (CFS) of strains against strains. To study the antibiofilm mechanism against strains,...
This study aims to determine the antibiofilm effect of cell-free supernatant (CFS) of strains against strains. To study the antibiofilm mechanism against strains, antibacterial effects, cell surface properties (auto-aggregation and cell surface hydrophobicity), exopolysaccharide (EPS) production, and morphological changes were examined. The antibiofilm effect of KCCM 202399 CFS as morphological changes were evaluated by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM), compared with the control treatment. Among the strains, KCCM 202399 showed the highest antibiofilm effect on KCTC 5458. The antibacterial effect of KCCM 202399 against KCTC 5458 was investigated using the deferred method (16.00 mm). The minimum inhibitory concentration of KCCM 202399 against KCTC 5458 was 25.00%. Compared with the control treatment, KCCM 202399 CFS inhibited the bacterial adhesion of KCTC 5458 by decreasing auto-aggregation, cell surface hydrophobicity, and EPS production (45.91%, 40.51%, and 67.44%, respectively). KCCM 202399 CFS inhibited and eradicated the KCTC 5458 biofilm. Therefore, these results suggest that KCCM 202399 CFS may be used to develop oral health in the probiotic industry.
Topics: Anti-Bacterial Agents; Bacterial Adhesion; Biofilms; Dental Caries; Fermented Foods; Levilactobacillus brevis; Microbial Sensitivity Tests; Probiotics; Republic of Korea; Streptococcus mutans
PubMed: 34675145
DOI: 10.4014/jmb.2109.09045 -
Viruses Apr 2019has been widely used in industry for fermentation purposes. However, it is also associated with the spoilage of foods and beverages, in particular, beer. There is an...
has been widely used in industry for fermentation purposes. However, it is also associated with the spoilage of foods and beverages, in particular, beer. There is an increasing demand for natural food preservation methods, and in this context, bacteriophages possess the potential to control such spoilage bacteria. Just a few studies on phages infecting have been performed to date and in the present study, we report the isolation and characterization of five virulent phages capable of infecting strains. The analysis reveals a high diversity among the isolates, with members belonging to both, the and families. One isolate, designated phage 3-521, possesses a genome of 140.8 kb, thus representing the largest phage genome sequenced to date. While the isolated phages do not propagate on beer-spoiling strains, phages showed activity against these strains, impairing the growth of some strains. The results highlight the potential of bacteriophage-based treatments as an effective approach to prevent bacterial spoilage of beer.
Topics: Bacteriophages; Beer; Fermentation; Food Microbiology; Genome, Viral; Genomics; Host Specificity; Levilactobacillus brevis; Phylogeny; Proteomics
PubMed: 31035495
DOI: 10.3390/v11050393 -
Oxidative Medicine and Cellular... 2021The purpose of this research is to explore the positive effects of and on the tissue damage and microbial community in mice challenged by Enterotoxigenic (ETEC)....
The purpose of this research is to explore the positive effects of and on the tissue damage and microbial community in mice challenged by Enterotoxigenic (ETEC). Twenty-four mice were divided into four groups randomly: the CON group, ETEC group, LP-ETEC group and LB-ETEC group. Our results demonstrated that, compared with the ETEC group, the LP-ETEC and LB-ETEC groups experienced less weight loss and morphological damage of the jejunum. We measured proinflammatory factors of colonic tissue and found that and inhibited the expression of proinflammatory factors such as IL-, TNF-, and IL-6 and promoted that of the tight junction protein such as claudin-1, occludin, and ZO-1. Additionally, and altered the impact of ETEC on the intestinal microbial community of mice, significantly increased the abundance of probiotics such as , and reduced that of pathogenic bacteria such as , , , and . Therefore, we believe that and can stabilize the intestinal microbiota and inhibit the growth of pathogenic bacteria, thus protecting mice from the gut inflammation induced by ETEC.
Topics: Animals; Claudin-1; Disease Models, Animal; Enterotoxigenic Escherichia coli; Escherichia coli Infections; Gastrointestinal Microbiome; Interleukin-1beta; Jejunum; Levilactobacillus brevis; Lactobacillus plantarum; Mice; Mice, Inbred ICR; Probiotics; Tumor Necrosis Factor-alpha
PubMed: 34594475
DOI: 10.1155/2021/6867962 -
Frontiers in Immunology 2023Type 2 diabetes (T2DM) clinically exhibits a higher incidence of hepatocellular carcinoma (HCC), contributing to a lousy prognosis in patients harboring both diseases....
Type 2 diabetes (T2DM) clinically exhibits a higher incidence of hepatocellular carcinoma (HCC), contributing to a lousy prognosis in patients harboring both diseases. Microflora-based therapy draws attention with low side effects. Accumulating evidence shows that can improve blood glucose and body weight of the T2DM mice model and reduce several cancer incidences. However, the therapeutic effect of in affecting the prognosis of T2DM+HCC remains unknown. In this study, we aim to explore this question an established T2DM+HCC mice model. We observed a significant alleviation after the probiotic intervention. improves blood glucose and insulin resistance and ameliorates Mechanically. Combined with a multi-omics approach including 16SrDNA, GC-MS, and RNA-seq, we identified distinct intestinal microflora composition and metabolites after intervention. Furthermore, we found that delayed disease progression by regulating MMP9 and NOTCH 1 signaling pathways, potentially through gut microflora and BA interaction. This study indicates that may improve the prognosis of T2DM + HCC, providing novel therapeutic opportunities targeting intestinal flora for patients with T2DM+HCC.
Topics: Mice; Animals; Levilactobacillus brevis; Diabetes Mellitus, Type 2; Gastrointestinal Microbiome; Carcinoma, Hepatocellular; Bile Acids and Salts; Blood Glucose; Liver Neoplasms; Disease Models, Animal
PubMed: 37234174
DOI: 10.3389/fimmu.2023.1179014 -
Frontiers in Microbiology 2019is a lactic acid bacterium that is known as a food and beverage spoilage organism, and more specifically as a beer-spoiler. Phages of have been described, but very...
is a lactic acid bacterium that is known as a food and beverage spoilage organism, and more specifically as a beer-spoiler. Phages of have been described, but very limited data is available regarding temperate phages of . Temperate phages may exert benefits to the host, while they may also be employed to combat beer spoilage. The current study reports on the incidence of prophage sequences present in nineteen distinct genomes. Prophage induction was evaluated using mitomycin C exposure followed by genome targeted-PCR, electron microscopy and structural proteome analysis. The morphological and genome sequence analyses revealed significant diversity among prophages, which appear to be dominated by members of the phage family. Based on this analysis, we propose a classification of phages into five groups.
PubMed: 31681247
DOI: 10.3389/fmicb.2019.02396 -
Antioxidants (Basel, Switzerland) Sep 2021The development of convenient and accessible health-functional foods has become an area of increased interest in recent years. Probiotics, ginseng, and yogurts have been...
The development of convenient and accessible health-functional foods has become an area of increased interest in recent years. Probiotics, ginseng, and yogurts have been recognized as representative nutraceutical products. To improve the functionality of yogurts, co-fermentation was performed during yogurt preparation. Four kinds of yogurt were prepared using a combination of probiotic B7 and hydroponic ginseng based on plain yogurt. The fundamental characteristics of yogurts, including pH, titratable acidity, microbial counts, color, and physicochemical properties, were determined. To assess functionality, four different antioxidant assays and real-time PCR analysis using RAW 264.7 cells were performed. Finally, sensory evaluation was conducted to evaluate customer preference. Hydroponic ginseng supplementation influenced pH, solid content, lightness, and yellowness. However, probiotic supplementation did not affect most factors except pH. In functionality analysis, the yogurt co-fermented with probiotics and ginseng showed the highest antioxidant activity and gene expression levels of the immune-related factors TNF-α and iNOS in RAW 264.7 cells. Although ginseng supplementation received poor acceptance because of its color and flavor, these attempts were considered beneficial despite the risk. Overall, co-fermentation within a short yogurt preparation time presented the potential for improvement of functionality. These findings suggest a range of feasibility for the development of attractive nutraceutical products.
PubMed: 34573079
DOI: 10.3390/antiox10091447