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Scientific Reports May 2024Recently, Lactobacillus johnsonii N6.2-derived extracellular vesicles (EVs) were shown to reduce apoptosis in human beta cell lines and stimulate insulin secretion in...
Recently, Lactobacillus johnsonii N6.2-derived extracellular vesicles (EVs) were shown to reduce apoptosis in human beta cell lines and stimulate insulin secretion in human islets. Our goal was to identify a physiologically relevant environmental condition that induces a hypervesiculation phenotype in L. johnsonii N6.2 and to evaluate if transcriptional changes are involved in this process. Culturing this strain in the presence of 0.2% bovine bile, which mimics a stressor encountered by the bacterium in the small intestine, resulted in approximately a 100-fold increase in EVs relative to cells grown in media without bile. Whole transcriptome analysis of cells grown with bile revealed upregulation of several peptidoglycan hydrolases as well as several genes involved in fatty acid utilization. These results suggest that the hypervesiculation phenotype may be the result of increased cell wall turnover combined with increased accumulation of phospholipids, in agreement with our previous proteomic and lipidomics results. Additionally, EVs isolated from L. johnsonii N6.2 grown in presence of bile maintained their immunomodulatory properties in host-derived βlox5 pancreatic and THP-1 macrophage cell lines. Our findings suggest that in L. johnsonii N6.2 vesiculogenesis is significantly impacted by the expression of cell wall modifying enzymes and proteins utilized for exogenous fatty acid uptake that are regulated at the transcriptional level. Furthermore, this data suggests that vesiculogenesis could be stimulated in vivo using small molecules thereby maximizing the beneficial interactions between bacteria and their hosts.
Topics: Extracellular Vesicles; Humans; Lactobacillus johnsonii; Bile; Animals; Cell Line; Cattle; THP-1 Cells; Cell Wall; Gene Expression Profiling
PubMed: 38806562
DOI: 10.1038/s41598-024-62843-0 -
Journal of Agricultural and Food... Jun 2024Tolerance to bile stress is a crucial property for lactic acid bacteria (LAB) to survive in the gastrointestinal tract and exert their beneficial effects. Whey powder...
Tolerance to bile stress is a crucial property for lactic acid bacteria (LAB) to survive in the gastrointestinal tract and exert their beneficial effects. Whey powder enriched with milk fat globule membrane proteins (M-WPI) as a functional component is protective for strains under stress conditions. The current study investigated the key mechanisms of action involved in () CGMCC 23701 survival in the presence of bile and the protective mechanism of M-WPI. According to proteomic analysis (proteomics), there could be several reasons for the greater protective effect of M-WPI. These include promoting the synthesis of fatty acids and peptidoglycans to repair the structure of the cell surface, regulating the metabolism of carbohydrates and amino acids to release energy and produce a range of precursors, enabling the expression of the repair system to repair damaged DNA, and promoting the expression of proteins associated with the multidrug efflux pump, which facilitates the exocytosis of intracellular bile salts. This study helps us to better understand the changes in proteome of CGMCC 23701 under bile salt stress and M-WPI protection, which will provide a new method for the protection and development of functional LAB.
Topics: Lactobacillus plantarum; Lipid Droplets; Proteomics; Glycolipids; Bile Acids and Salts; Bacterial Proteins; Glycoproteins; Membrane Proteins; Stress, Physiological; Animals; Membrane Glycoproteins
PubMed: 38805674
DOI: 10.1021/acs.jafc.4c01747 -
Journal of Bioscience and Bioengineering May 2024Shewanella vesiculosa HM13, a psychrotrophic gram-negative bacterium isolated from the intestinal contents of horse mackerel, produces abundant extracellular membrane...
Enhancing extracellular membrane vesicle productivity of Shewanella vesiculosa HM13, a prospective host for vesiculation-mediated protein secretion, by weakening outer membrane-peptidoglycan linkage.
Shewanella vesiculosa HM13, a psychrotrophic gram-negative bacterium isolated from the intestinal contents of horse mackerel, produces abundant extracellular membrane vesicles (EMVs) by budding the outer membrane. The EMVs of this bacterium carry a single major cargo protein, P49, of unknown function, which may be useful as a carrier for the secretory production of heterologous proteins as cargoes of EMVs. In this study, to increase the utility of S. vesiculosa HM13 as a host for EMV-mediated protein production, we improved its EMV productivity by weakening the linkage between the outer membrane and underlying peptidoglycan layer. In gram-negative bacteria, the outer membrane is connected to peptidoglycans predominantly through Braun's lipoprotein (Lpp), and the formation of this linkage is catalyzed by an l,d-transpeptidase (Ldt). We constructed gene-disrupted mutants of Lpp and Ldt and assessed their EMV productivity. The EMVs of the lpp- and ldt-disrupted mutants grown at 18 °C were evaluated using nanoparticle tracking analysis, and their morphologies were observed using transmission electron microscopy. As a result, an approximately 2.5-fold increase in EMV production was achieved, whereas the morphology of the EMVs of these mutants remained almost identical to that of the parent strain. In accordance with the increase in EMV production, the mutants secreted approximately 2-fold higher amounts of P49 than the parent strain into the culture broth as the EMV cargo. These findings will contribute to the development of an EMV-based secretory production system for heterologous proteins using S. vesiculosa HM13 as a host.
PubMed: 38796341
DOI: 10.1016/j.jbiosc.2024.05.005 -
International Journal of Antimicrobial... May 2024The emergence of multidrug-resistant pathogens has outpaced the development of new antibiotics, leading to renewed interest in endolysins. Endolysins have been...
The emergence of multidrug-resistant pathogens has outpaced the development of new antibiotics, leading to renewed interest in endolysins. Endolysins have been investigated as novel biocontrol agents for Gram-positive bacteria. However, their efficacy against Gram-negative species is limited by the barrier presented by their outer membrane, which prevents endolysin access to the peptidoglycan substrate. Here, we used the translocation domain of botulinum neurotoxin to deliver endolysin across the outer membrane of Gram-negative bacteria. The translocation domain selectively interacts with and penetrates membranes composed of anionic lipids, which have been used in nature to deliver various proteins into animal cells. In addition to the botulinum neurotoxin translocation domain, we have fused bacteriophage-derived receptor binding protein to endolysins. This allows the attached protein to efficiently bind to a broad spectrum of Gram-negative bacteria. By attaching these target-binding and translocation machineries to endolysins, we aimed to develop an engineered endolysin with broad-spectrum targeting and enhanced antibacterial activity against Gram-negative species. To validate our strategy, we designed engineered endolysins using two well-known endolysins, T5 and LysPA26, and tested them against 23 strains from six species of Gram-negative bacteria, confirming that our machinery can act broadly. In particular, we observed a 2.32 log reduction in 30 min with only 0.5 µM against an Acinetobacter baumannii isolate. We also used the SpyTag/SpyCatcher system to easily attach target-binding proteins, thereby improving its target-binding ability. Overall, our newly developed endolysin engineering strategy may be a promising approach to control multidrug-resistant Gram-negative bacterial strains.
PubMed: 38795926
DOI: 10.1016/j.ijantimicag.2024.107216 -
Journal of Cosmetic Dermatology May 2024Acne vulgaris, a common chronic dermatological condition worldwide, is associated with inflammatory response and Cutibacterium acnes. Individuals with acne vulgaris and...
BACKGROUND
Acne vulgaris, a common chronic dermatological condition worldwide, is associated with inflammatory response and Cutibacterium acnes. Individuals with acne vulgaris and sensitive skin have limited suitable treatments due to the skin irritation and side effects exhibited by current hydroxy acidic medications.
AIMS
This study aimed to evaluate the synergistic effects of Guaiacum officinale (GO) and Rhodomyrtus Tomentosa (RT) extracts for treating acne vulgaris on sensitive skin by inhibiting inflammation.
METHODS
The phytochemical constituents and antioxidant activity of GO and RT extracts were determined in vitro. The anti-inflammatory effects were investigated in peptidoglycan (PGN)-induced HaCaT cells. Further, a 28-day clinical trial was conducted involving 30 subjects with both sensitive skin and acne to evaluate the efficacy and subjects' satisfaction.
RESULTS
Total phenolics and flavonoids were detected in GO and RT extracts, the IC values for DPPH radical scavenging were 6.15 wt% and 0.76 wt%, respectively. The combination of GO and RT extracts at a 1:1 (v/v) ratio significantly decreased the expression of TLR-2 and TLR-4, as well as the secretion of IL-1α, IL-8, and TNF-α in PGN-induced HaCaT cells, by 2.30-7.93 times compared to GO extract alone (p < 0.05). Moreover, the cream containing 5 wt% the combination significantly improved facial acne and redness (p < 0.05). The number of comedones decreased by 50.00% and papules by 30.65% after 28 days of application. No adverse events were reported and 96.67% of the subjects were satisfied with the treatment.
CONCLUSION
The efficacy of the GO and RT extracts in synergistically suppressing inflammation, improving acne vulgaris, and reducing redness. The study offers an effective and non-irritant treatment for acne vulgaris in individuals with sensitive skin.
PubMed: 38790116
DOI: 10.1111/jocd.16394 -
Probiotics and Antimicrobial Proteins May 2024Commensal-derived peptidoglycan (PG) or lipoteichoic acid (LTA) can improve the growth, immunity, and intestinal health of fish, but it is not clear whether the two...
Commensal Bacillus pumilus SE5-Derived Peptidoglycan and Lipoteichoic Acid Showed Synergistic Effects in Improving Growth, Immunity, and Intestinal Health of Grouper (Epinephelus coioides).
Commensal-derived peptidoglycan (PG) or lipoteichoic acid (LTA) can improve the growth, immunity, and intestinal health of fish, but it is not clear whether the two components have synergistic effects. To clarify this, grouper (Epinephelus coioides) was fed basal diet (CG) or diets containing 1.0 × 10 CFU/g heat-inactivated SE5 (HIB), PG (21.30 mg/kg), LTA (6.70 mg/kg), mixture (PL1) of PG (10.65 mg/kg) and LTA (3.35 mg/kg), and mixture (PL2) of PG (21.30 mg/kg) and LTA (6.70 mg/kg). Improved growth performance and feed utilization were observed in groups PG, LTA, PL1, and PL2, and the optimum growth performance was recorded in group PL1. Furthermore, improved serum alkaline phosphatase (AKP) activity and immunoglobulin M (IgM) and complement C3 (C3) contents were observed in all treatments, and the AKP activity in group PL1 was significantly superior to that of groups PG and LTA. Although PG and LTA alone or in combination exert comparable effects on intestinal microbiota and physical structure, obviously enhanced intestinal protease activity was observed in group PL1. The combined efficacy of PL1 could further potentiate the immune response by modulating the nucleotide-binding oligomerization domain-containing protein 2 (NOD2) and upregulating the expression of antimicrobial peptides (epinecidin-1, hepcidin-1, and β-defensin) as well as IgM. At the same time, group PL1 could further mitigate intestinal inflammation by downregulating pro-inflammatory cytokines and upregulating anti-inflammatory cytokines. In conclusion, probiotic B. pumilus SE5-derived PG and LTA mixture (10.65 mg/kg PG and 3.35 mg/kg LTA) exhibits better potential for improving the growth performance, intestinal health, and immune function compared to another mixture (21.30 mg/kg PG and 6.70 mg/kg LTA) and PG or LTA alone in grouper.
PubMed: 38789900
DOI: 10.1007/s12602-024-10291-7 -
The Journal of Physical Chemistry. B Jun 2024The cell envelope of Gram-negative bacteria is composed of an outer membrane (OM) and an inner membrane (IM) and a peptidoglycan cell wall (CW) between them. Combined...
The cell envelope of Gram-negative bacteria is composed of an outer membrane (OM) and an inner membrane (IM) and a peptidoglycan cell wall (CW) between them. Combined with Braun's lipoprotein (Lpp), which connects the OM and the CW, and numerous membrane proteins that exist in both OM and IM, the cell envelope creates a mechanically stable environment that resists various physical and chemical perturbations to the cell, including turgor pressure caused by the solute concentration difference between the cytoplasm of the cell and the extracellular environment. Previous computational studies have explored how individual components (OM, IM, and CW) can resist turgor pressure although combinations of them have been less well studied. To that end, we constructed multiple OM-CW systems, including the Lpp connections with the CW under increasing degrees of strain. The results show that the OM can effectively resist the tension imposed by the CW, shrinking by only 3-5% in area even when the CW is stretched to 2.5× its relaxed area. The area expansion modulus of the system increases with increasing CW strain, although the OM remains a significant contributor to the envelope's mechanical stability. Additionally, we find that when the protein TolC is embedded in the OM, its stiffness increases.
Topics: Cell Wall; Peptidoglycan; Bacterial Outer Membrane Proteins; Bacterial Outer Membrane; Molecular Dynamics Simulation
PubMed: 38787347
DOI: 10.1021/acs.jpcb.3c08510 -
Marine Drugs May 2024The deep-sea bacterium CSC3.9 has significant inhibitory effects on agricultural pathogenic fungi and human pathogenic bacteria, especially , the notorious...
The deep-sea bacterium CSC3.9 has significant inhibitory effects on agricultural pathogenic fungi and human pathogenic bacteria, especially , the notorious multidrug-resistant pathogen affecting human public health. We demonstrate that the corresponding antibacterial agents against PAO1 are volatile organic compounds (VOCs, namely VOC-3.9). Our findings show that VOC-3.9 leads to the abnormal cell division of PAO1 by disordering the expression of several essential division proteins associated with septal peptidoglycan synthesis. VOC-3.9 hinders the biofilm formation process and promotes the biofilm dispersion process of PAO1 by affecting its quorum sensing systems. VOC-3.9 also weakens the iron uptake capability of PAO1, leading to reduced enzymatic activity associated with key metabolic processes, such as reactive oxygen species (ROS) scavenging. Overall, our study paves the way to developing antimicrobial compounds against drug-resistant bacteria by using volatile organic compounds.
Topics: Pseudomonas aeruginosa; Volatile Organic Compounds; Anti-Bacterial Agents; Biofilms; Quorum Sensing; Microbial Sensitivity Tests; Reactive Oxygen Species; Humans
PubMed: 38786624
DOI: 10.3390/md22050233 -
Antibiotics (Basel, Switzerland) May 2024Chlamydial infections and diseases caused by filarial nematodes are global health concerns. However, treatment presents challenges due to treatment failures potentially...
Chlamydial infections and diseases caused by filarial nematodes are global health concerns. However, treatment presents challenges due to treatment failures potentially caused by persisting and long regimens against filarial infections accompanied by low compliance. A new treatment strategy could be the targeting of the reduced peptidoglycan structures involved in cell division in the obligate intracellular bacteria and , the latter being obligate endosymbionts supporting filarial development, growth, and survival. Here, cell culture experiments with and showed that the nucleoside antibiotics muraymycin and carbacaprazamycin interfere with bacterial cell division and induce enlarged, aberrant cells resembling the penicillin-induced persistence phenotype in Enzymatic inhibition experiments with purified MraY revealed that muraymycin derivatives abolish the synthesis of the peptidoglycan precursor lipid I. Comparative in silico analyses of chlamydial and wolbachial MraY with the corresponding well-characterized enzyme in revealed a high degree of conservation, providing evidence for a similar mode of inhibition. Muraymycin D2 treatment eradicated persisting non-dividing cells from an established penicillin-induced persistent infection. This finding indicates that nucleoside antibiotics may have additional properties that can break bacterial persistence.
PubMed: 38786149
DOI: 10.3390/antibiotics13050421 -
Frontiers in Microbiology 2024
PubMed: 38784805
DOI: 10.3389/fmicb.2024.1329047