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Applied and Environmental Microbiology Feb 2022It has been demonstrated that quorum sensing (QS) is widely employed by bacterial cells to coordinately regulate various group behaviors. Diffusible signal factor... (Review)
Review
It has been demonstrated that quorum sensing (QS) is widely employed by bacterial cells to coordinately regulate various group behaviors. Diffusible signal factor (DSF)-type signals have emerged as a growing family of conserved cell-cell communication signals. In addition to the DSF signal initially identified in Xanthomonas campestris pv. campestris, iffusible ignal actor (BDSF) (-2-dodecenoic acid) has been recognized as a conserved DSF-type signal with specific characteristics in both signal perception and transduction from DSF signals. Here, we review the history and current progress of the research on this type of signal, especially focusing on its biosynthesis, signaling pathways, and biological functions. We also discuss and explore the huge potential of targeting this kind of QS system as a new therapeutic strategy to control bacterial infections and diseases.
Topics: Bacterial Proteins; Burkholderia; Burkholderia cenocepacia; Fatty Acids, Monounsaturated; Gene Expression Regulation, Bacterial; Quorum Sensing; Suppressor Factors, Immunologic
PubMed: 34985987
DOI: 10.1128/aem.02342-21 -
Nutrition & Metabolism Jun 2023Non-alcoholic steatohepatitis (NASH) is a major contributor to liver cirrhosis and hepatocellular carcinoma. There remains no effective pharmacological therapy. The...
BACKGROUND
Non-alcoholic steatohepatitis (NASH) is a major contributor to liver cirrhosis and hepatocellular carcinoma. There remains no effective pharmacological therapy. The hepatic lipid metabolism and fatty acid β-oxidation are regulated by Perilipin5 (Plin5). However, it is yet unknown how Plin5 affects NASH and the molecular process.
METHODS
High-fat, high-cholesterol and high-fructose (HFHC) diets were used to mimic the progression of NASH in wild type (WT) mice and Plin5 knockout (Plin5 KO) mice. The degree of ferroptosis was measured by detecting the expression of key genes of ferroptosis and the level of lipid peroxide. The degree of NASH was judged by observing the morphology of the liver, detecting the expression of inflammation and fibrosis related genes of liver damage. Plin5 was overexpressed in the liver of mice by tail vein injection of adenovirus, and the process of NASH was simulated by methionine choline deficiency (MCD) diet. The occurrence of ferroptosis and NASH was detected by the same detection method. Targeted lipidomics sequencing was used to detect the difference in free fatty acid expression in the WT Plin5 KO group. Finally, it was verified in cell experiments to further study the effect of free fatty acids on ferroptosis of hepatocytes.
RESULTS
In various NASH models, hepatic Plin5 was dramatically reduced. Plin5 knockout (KO) worsened NASH-associated characteristics in mice given a high-fat/high-cholesterol (HFHC) diet, such as lipid accumulation, inflammation and hepatic fibrosis. It has been shown that ferroptosis is involved in NASH progression. We revealed that Plin5 KO in mice aggravated the degree of ferroptosis in NASH models. Conversely, overexpression of Plin5 significantly alleviated ferroptosis and further ameliorated progression of MCD-induced NASH. Analysis of livers obtained from HFHC diet-fed mice by targeted lipidomics revealed that 11-Dodecenoic acid was significantly decreased in Plin5 KO mice. Addition of 11-Dodecenoia acid to Plin5 knockdown hepatocytes effectively prevented ferroptosis.
CONCLUSION
Our study demonstrates that Plin5 protects against NASH progression by increasing 11-Dodecenoic acid level and further inhibiting ferroptosis, suggesting that Plin5 has therapeutic potential as a target for the management of NASH.
PubMed: 37349836
DOI: 10.1186/s12986-023-00751-2 -
Microbiology Spectrum Oct 2021Asthma is a multifactorial disorder, and microbial dysbiosis enhances lung inflammation and asthma-related symptoms. Probiotics have shown anti-inflammatory effects and... (Randomized Controlled Trial)
Randomized Controlled Trial
Asthma is a multifactorial disorder, and microbial dysbiosis enhances lung inflammation and asthma-related symptoms. Probiotics have shown anti-inflammatory effects and could regulate the gut-lung axis. Thus, a 3-month randomized, double-blind, and placebo-controlled human trial was performed to investigate the adjunctive efficacy of probiotics in managing asthma. Fifty-five asthmatic patients were randomly assigned to a probiotic group ( = 29; received Bifidobacterium lactis Probio-M8 powder and Symbicort Turbuhaler) and a placebo group ( = 26; received placebo and Symbicort Turbuhaler), and all 55 subjects provided details of their clinical history and demographic data. However, only 31 patients donated a complete set of fecal and blood samples at all three time points for further analysis. Compared with those of the placebo group, co-administering Probio-M8 with Symbicort Turbuhaler significantly decreased the fractional exhaled nitric oxide level at day 30 (= 0.049) and improved the asthma control test score at the end of the intervention (= 0.023). More importantly, the level of alveolar nitric oxide concentration decreased significantly among the probiotic receivers at day 30 (= 0.038), and the symptom relief effect was even more obvious at day 90 (= 0.001). Probiotic co-administration increased the resilience of the gut microbiome, which was reflected by only minor fluctuations in the gut microbiome diversity (> 0.05, probiotic receivers; < 0.05, placebo receivers). Additionally, the probiotic receivers showed significantly changes in some species-level genome bins (SGBs), namely, increases in potentially beneficial species Bifidobacterium animalis, Bifidobacterium longum, and sp. CAG and decreases in Parabacteroides distasonis and (< 0.05). Compared with that of the placebo group, the gut metabolic potential of probiotic receivers exhibited increased levels of predicted microbial bioactive metabolites (linoleoyl ethanolamide, adrenergic acid, erythronic acid) and serum metabolites (5-dodecenoic acid, tryptophan, sphingomyelin) during/after intervention. Collectively, our results suggested that co-administering Probio-M8 synergized with conventional therapy to alleviate diseases associated with the gut-lung axis, like asthma, possibly via activating multiple anti-inflammatory pathways. The human gut microbiota has a potential effect on the pathogenesis of asthma and is closely related to the disease phenotype. Our trial has demonstrated that co-administering Probio-M8 synergized with conventional therapy to alleviate asthma symptoms. The findings of the present study provide new insights into the pathogenesis and treatment of asthma, mechanisms of novel therapeutic strategies, and application of probiotics-based therapy.
Topics: Adolescent; Adult; Aged; Anti-Asthmatic Agents; Anti-Inflammatory Agents; Asthma; Bifidobacterium animalis; Budesonide, Formoterol Fumarate Drug Combination; Double-Blind Method; Dysbiosis; Female; Gastrointestinal Microbiome; Humans; Lung; Male; Middle Aged; Nitric Oxide; Placebos; Probiotics; Young Adult
PubMed: 34612663
DOI: 10.1128/Spectrum.00859-21 -
Biomedical and Environmental Sciences :... Mar 2019To evaluate the synergy of the Burkholderia signaling molecule cis-2-dodecenoic acid (BDSF) and fluconazole (FLU) or itraconazole (ITRA) against two azole-resistant C....
OBJECTIVE
To evaluate the synergy of the Burkholderia signaling molecule cis-2-dodecenoic acid (BDSF) and fluconazole (FLU) or itraconazole (ITRA) against two azole-resistant C. albicans clinical isolates in vitro and in vivo.
METHODS
Minimum inhibitory concentrations (MICs) of antibiotics against two azole-resistant C. albicans were measured by the checkerboard technique, E-test, and time-kill assay. In vivo antifungal synergy testing was performed on mice. Analysis of the relative gene expression levels of the strains was conducted by quantitative reverse-transcription polymerase chain reaction (qRT-PCR).
RESULTS
BDSF showed highly synergistic effects in combination with FLU or ITRA with a fractional inhibitory concentration index of ⪕ 0.08. BDSF was not cytotoxic to normal human foreskin fibroblast cells at concentrations of up to 300 μg/mL. The qRT-PCR results showed that the combination of BDSF and FLU/ITRA significantly inhibits the expression of the efflux pump genes CDR1 and MDR1 via suppression of the transcription factors TAC1 and MRR1, respectively, when compared with FLU or ITRA alone. No dramatic difference in the mRNA expression levels of ERG1, ERG11, and UPC2 was found, which indicates that the drug combinations do not significantly interfere with UPC2-mediated ergosterol levels. In vivo experiments revealed that combination therapy can be an effective therapeutic approach to treat candidiasis.
CONCLUSION
The synergistic effects of BDSF and azoles may be useful as an alternative approach to control azole-resistant Candida infections.
Topics: Antifungal Agents; Burkholderia cenocepacia; Candida albicans; Candidiasis; Drug Resistance, Fungal; Fatty Acids, Monounsaturated; Fluconazole; Humans; Microbial Sensitivity Tests; Triazoles
PubMed: 30987694
DOI: 10.3967/bes2019.027 -
Blocking of Candida albicans biofilm formation by cis-2-dodecenoic acid and trans-2-dodecenoic acid.Journal of Medical Microbiology Nov 2011Candida is an important opportunistic human fungal pathogen. Infections caused by Candida albicans are related to the formation of a biofilm. The biofilm enhances the...
Candida is an important opportunistic human fungal pathogen. Infections caused by Candida albicans are related to the formation of a biofilm. The biofilm enhances the resistance of the C. albicans defence system, increases its resistance to antifungal drugs and induces increased drug tolerance, making clinical care more challenging. The in vitro activity of cis-2-dodecenoic acid (BDSF; a diffusible signal factor from Burkholderia cenocepacia) and trans-2-dodecenoic acid (trans-BDSF) against C. albicans growth, germ-tube germination and biofilm formation was estimated by absorbance measurements and microscopic assessments. C. albicans biofilms were prepared using a static microtitre plate model. Quantitative analysis of biofilm formation was performed using a 2,3-bis(2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide reduction assay to evaluate the effect of different concentrations of BDSF and trans-BDSF at different stages of biofilm formation. Reductions in biofilm structure and formation were visualized by inverted microscopy. Real-time RT-PCR was employed to estimate the mRNA expression levels of the hyphae-specific genes HWP1 and ALS3. It was found that 30 µM of either BDSF or trans-BDSF reduced germ-tube formation by approximately 70 % without inhibiting yeast growth. Yeast growth was strongly repressed by the exogenous addition of 300 µM BDSF and trans-BDSF at 0 and 1 h after cell attachment, with biofilm formation being reduced by approximately 90 and 60 %, respectively. BDSF and trans-BDSF were more effective against biofilm formation than farnesol and the diffusible signal factor cis-11-methyl-2-dodecenoic acid. None of the four drugs was able to destroy pre-formed biofilms. Real-time RT-PCR analysis showed that HWP1 was downregulated by approximately 90 % and ALS3 was downregulated by 70-80 % by 60 µM BDSF and trans-BDSF, implying that BDSF and trans-BDSF block C. albicans biofilm formation by interfering with the morphological switch. These results suggest that BDSF and trans-BDSF are potentially useful therapeutic agents worthy of further study.
Topics: Biofilms; Candida albicans; Candidiasis; Down-Regulation; Fatty Acids, Monounsaturated; Fungal Proteins; Humans; Hyphae; Membrane Glycoproteins; Microscopy, Fluorescence; Microscopy, Phase-Contrast; RNA, Messenger; Reverse Transcriptase Polymerase Chain Reaction; Stereoisomerism
PubMed: 21778264
DOI: 10.1099/jmm.0.029058-0 -
Biomedical and Environmental Sciences :... Nov 2018To evaluate the efficacy of cis-2-dodecenoic acid (BDSF) in the treatment and prevention of vaginal candidiasis in vivo.
OBJECTIVE
To evaluate the efficacy of cis-2-dodecenoic acid (BDSF) in the treatment and prevention of vaginal candidiasis in vivo.
METHODS
The activities of different concentrations of BDSF against the virulence factors of Candida albicans (C. albicans) were determined in vitro. An experimental mouse model of Candida vaginitis was treated with 250 μmol/L BDSF. Treatment efficiency was evaluated in accordance with vaginal fungal burden and inflammation symptoms.
RESULTS
In vitro experiments indicated that BDSF attenuated the adhesion and damage of C. albicans to epithelial cells by decreasing phospholipase secretion and blocking filament formation. Treatment with 30 μmol/L BDSF reduced the adhesion and damage of C. albicans to epithelial cells by 36.9% and 42.3%, respectively. Treatment with 200 μmol/L BDSF completely inhibited phospholipase activity. In vivo mouse experiments demonstrated that BDSF could effectively eliminate vaginal infection and relieve inflammatory symptoms. Four days of treatment with 250 μmol/L BDSF reduced vaginal fungal loads by 6-fold and depressed inflammation. Moreover, BDSF treatment decreased the expression levels of the inflammatory chemokine-associated genes MCP-1 and IGFBP3 by 2.5- and 2-fold, respectively.
CONCLUSION
BDSF is a novel alternative drug that can efficiently control vaginal candidiasis by inhibiting the virulence factors of C. albicans.
Topics: Animals; Candida albicans; Candidiasis, Vulvovaginal; Chemokine CCL2; Disease Models, Animal; Fatty Acids, Monounsaturated; Female; Fungal Proteins; Humans; Insulin-Like Growth Factor Binding Protein 3; Mice; Virulence; Virulence Factors
PubMed: 30558702
DOI: 10.3967/bes2018.109 -
Plant Physiology Mar 197912-Oxo-trans-10-dodecenoic acid (trans-10-ODA) is an oxidation product of polyunsaturated fatty acids in plant tissues. The structural similarity of trans-10-ODA and...
12-Oxo-trans-10-dodecenoic acid (trans-10-ODA) is an oxidation product of polyunsaturated fatty acids in plant tissues. The structural similarity of trans-10-ODA and traumatic acid, a compound considered to be a wound hormone, suggested that trans-10-ODA might be a precursor of traumatic acid. Both trans-10-ODA and traumatic acid were active in the Wehnelt bean assay. The results were more consistent with trans-10-ODA than with traumatic acid. Cucumber (Cucumis sativus L. var. National Pickling) hypocotyls also showed a growth increase following treatment with trans-10-ODA, which suggested that trans-10-ODA has a more general influence on plant development than previously ascribed to traumatic acid.Runner beans (Phaseolus vulgaris L. var. Kentucky Wonder) were analyzed for the presence of endogenous trans-10-ODA and traumatic acid. These are the beans from which traumatic acid was originally isolated in 1939. They contained trans-10-ODA but no traumatic acid. Young beans were a better source of trans-10-ODA than older beans and an increase in the esterified form of trans-10-ODA with age may have been due to a conversion of the free acid to the esterified form. The amount of endogenous trans-10-ODA increased when bean pod tissue was sliced and wounded. Rapid stirring and the presence of oxygen increased autooxidation of trans-10-ODA to traumatic acid in runner beans, which indicated that the compound identified as traumatic acid is formed by autooxidation of trans-10-ODA and that trans-10-ODA is a natural compound with growth-regulating properties.Enzyme extracts of runner beans synthesized trans-10-ODA from linoleic acid. No enzymic synthesis of traumatic acid was observed even when cofactors were added to the reaction mixture. This confirmed the conclusion that traumatic acid is formed by autooxidation of trans-10-ODA.
PubMed: 16660762
DOI: 10.1104/pp.63.3.536 -
Proceedings of the National Academy of... Dec 2017Quorum sensing (QS) signals are used by bacteria to regulate biological functions in response to cell population densities. Cyclic diguanosine monophosphate (c-di-GMP)...
Quorum sensing (QS) signals are used by bacteria to regulate biological functions in response to cell population densities. Cyclic diguanosine monophosphate (c-di-GMP) regulates cell functions in response to diverse environmental chemical and physical signals that bacteria perceive. In , the QS signal receptor RpfR degrades intracellular c-di-GMP when it senses the QS signal -2-dodecenoic acid, also called diffusible signal factor (BDSF), as a proxy for high cell density. However, it was unclear how this resulted in control of BDSF-regulated phenotypes. Here, we found that RpfR forms a complex with a regulator named GtrR (BCAL1536) to enhance its binding to target gene promoters under circumstances where the BDSF signal binds to RpfR to stimulate its c-di-GMP phosphodiesterase activity. In the absence of BDSF, c-di-GMP binds to the RpfR-GtrR complex and inhibits its ability to control gene expression. Mutations in and had overlapping effects on both the transcriptome and BDSF-regulated phenotypes, including motility, biofilm formation, and virulence. These results show that RpfR is a QS signal receptor that also functions as a c-di-GMP sensor. This protein thus allows to integrate information about its physical and chemical surroundings as well as its population density to control diverse biological functions including virulence. This type of QS system appears to be widely distributed in beta and gamma proteobacteria.
Topics: Animals; Bacterial Load; Bacterial Proteins; Biofilms; Burkholderia Infections; Burkholderia cenocepacia; Cyclic GMP; Fatty Acids, Monounsaturated; Gene Expression Regulation, Bacterial; Mice; Mutation; Phenotype; Quorum Sensing; Signal Transduction; Virulence
PubMed: 29158389
DOI: 10.1073/pnas.1709048114 -
Applied and Environmental Microbiology Apr 2019Quorum sensing (QS) signals are widely used by bacterial pathogens to control biological functions and virulence in response to changes in cell population densities....
Quorum sensing (QS) signals are widely used by bacterial pathogens to control biological functions and virulence in response to changes in cell population densities. employs a molecular mechanism in which the -2-dodecenoic acid (named iffusible ignal actor [BDSF]) QS system regulates -acyl homoserine lactone (AHL) signal production and virulence by modulating intracellular levels of cyclic diguanosine monophosphate (c-di-GMP). Thus, inhibition of BDSF signaling may offer a non-antibiotic-based therapeutic strategy against BDSF-regulated bacterial infections. In this study, we report the synthesis of small-molecule mimics of the BDSF signal and evaluate their ability to inhibit BDSF QS signaling in A novel structural analogue of BDSF, 14-Me-C (-14-methylpentadec-2-enoic acid), was observed to inhibit BDSF production and impair BDSF-regulated phenotypes in , including motility, biofilm formation, and virulence, while it did not inhibit the growth rate of this pathogen. 14-Me-C also reduced AHL signal production. Genetic and biochemical analyses showed that 14-Me-C inhibited the production of the BDSF and AHL signals by decreasing the expression of their synthase-encoding genes. Notably, 14-Me-C attenuated BDSF-regulated phenotypes in various species. These findings suggest that 14-Me-C could potentially be developed as a new therapeutic agent against pathogenic species by interfering with their QS signaling. is an important opportunistic pathogen which can cause life-threatening infections in susceptible individuals, particularly in cystic fibrosis and immunocompromised patients. It usually employs two types of quorum sensing (QS) systems, including the -2-dodecenoic acid (BDSF) system and -acyl homoserine lactone (AHL) system, to regulate virulence. In this study, we have designed and identified an unsaturated fatty acid compound (-14-methylpentadec-2-enoic acid [14-Me-C]) that is capable of interfering with QS signaling and virulence. We demonstrate that 14-Me-C reduced BDSF and AHL signal production in It also impaired QS-regulated phenotypes in various species. These results suggest that 14-Me-C could interfere with QS signaling in many species and might be developed as a new antibacterial agent.
Topics: Acyl-Butyrolactones; Bacterial Proteins; Biofilms; Burkholderia Infections; Burkholderia cenocepacia; Cyclic GMP; Fatty Acids, Monounsaturated; Gene Expression Regulation, Bacterial; Microbial Sensitivity Tests; Phenotype; Quorum Sensing; Signal Transduction; Virulence
PubMed: 30770405
DOI: 10.1128/AEM.00105-19 -
BMC Microbiology Oct 2013Cis-2-dodecenoic acid (BDSF) is well known for its important functions in intraspecies signaling in Burkholderia cenocepacia. Previous work has also established an...
BACKGROUND
Cis-2-dodecenoic acid (BDSF) is well known for its important functions in intraspecies signaling in Burkholderia cenocepacia. Previous work has also established an important role of BDSF in interspecies and inter-kingdom communications. It was identified that BDSF modulates virulence of Pseudomonas aeruginosa. However, how BDSF interferes with virulence of P. aeruginosa is still not clear.
RESULTS
We report here that BDSF mediates the cross-talk between B. cenocepacia and P. aeruginosa through interference with quorum sensing (QS) systems and type III secretion system (T3SS) of P. aeruginosa. Bioassay results revealed that exogenous addition of BDSF not only reduced the transcriptional expression of the regulator encoding gene of QS systems, i.e., lasR, pqsR, and rhlR, but also simultaneously decreased the production of QS signals including 3-oxo-C12-HSL, Pseudomonas quinolone signal (PQS) and C4-HSL, consequently resulting in the down-regulation of biofilm formation and virulence factor production of P. aeruginosa. Furthermore, BDSF and some of its derivatives are also capable of inhibiting T3SS of P. aeruginosa at a micromolar level. Treatment with BDSF obviously reduced the virulence of P. aeruginosa in both HeLa cell and zebrafish infection models.
CONCLUSIONS
These results depict that BDSF modulates virulence of P. aeruginosa through interference with QS systems and T3SS.
Topics: 4-Butyrolactone; Animals; Antibiosis; Bacterial Secretion Systems; Biofilms; Burkholderia cenocepacia; Disease Models, Animal; Epithelial Cells; Fatty Acids, Monounsaturated; Gene Expression Profiling; HeLa Cells; Homoserine; Humans; Pseudomonas Infections; Pseudomonas aeruginosa; Quinolones; Quorum Sensing; Signal Transduction; Virulence; Virulence Factors; Zebrafish
PubMed: 24134835
DOI: 10.1186/1471-2180-13-231