-
PloS One 2020In this study, we were challenging to identify characteristic compounds in breast cancer cell lines. GC analysis of extracts from the culture media of breast cancer cell...
In this study, we were challenging to identify characteristic compounds in breast cancer cell lines. GC analysis of extracts from the culture media of breast cancer cell lines (MCF-7, SK-BR-3, and YMB-1) using a solid-phase Porapak Q extraction revealed that two compounds of moderate volatility, 1-hexadecanol and 5-(Z)-dodecenoic acid, were detected with markedly higher amount than those in the medium of fibroblast cell line (KMST-6). Furthermore, LC-TOF/MS analysis of the extracts clarified that in addition to the above two fatty acids, the amounts of five unsaturated fatty acids [decenoic acid (C10:1), decadienoic acid (C10:2), 5-(Z)-dodecenoic acid (C12:1), 5-(Z)-tetradecenoic acid (C14:1), and tetradecadienoic acid (C14:2)] in MCF-7 medium were higher than those in medium of KMST-6. Interestingly, H2O2-oxidation of 5-(Z)-dodecenoic acid and 5-(Z)-tetradecenoic acid produced volatile aldehydes that were reported as specific volatiles in breath from various cancer patients, such as heptanal, octanal, nonanal, decanal, 2-(E)-nonenal, and 2-(E)-octenal. Thus, we concluded that these identified compounds over-produced in breast cancer cells in this study could serve as potential precursors producing reported cancer-specific volatiles.
Topics: Breast Neoplasms; Fatty Acids; Female; Gas Chromatography-Mass Spectrometry; Humans; Oxidation-Reduction; Solid Phase Microextraction; Tumor Cells, Cultured; Volatile Organic Compounds
PubMed: 32598404
DOI: 10.1371/journal.pone.0235442 -
Microorganisms Jan 2020-2-dodecenoic acid (i.e., Diffusible Signal Factor, BDSF), a signaling molecule produced by but not by , can prevent hyphal formation. The mechanism by which BDSF...
-2-dodecenoic acid (i.e., Diffusible Signal Factor, BDSF), a signaling molecule produced by but not by , can prevent hyphal formation. The mechanism by which BDSF controls the morphological switch of is still unknown. To address this issue, we used the cDNA microarray method to investigate the differential expression of genes in in the presence and absence of BDSF. The microarray result indicated that 305 genes were significantly different in the expression level. This included the downregulation of 75 genes and the upregulation of 230 genes. Based on the microarray data, a mutant library was screened to search for genes, once mutated, conferred insensitivity to BDSF. The results showed that the repressors (Ubi4 and Sfl1 proteins) and the activator (Sfl2 protein) of filamentous growth are involved in the BDSF regulation of hyphal morphogenesis. Ubi4, an ubiquitin polypeptide that participates in ubiquitin-mediated protein turnover, is the protein required for the degradation of Sfl2. Sfl1 and Sfl2 proteins antagonistically control morphogenesis. In the hyphal induction condition, the amount of Ubi4 and Sfl1 protein increased rapidly with the exogenous addition of BDSF. As a result, the protein level of the activator of filamentous growth, Sfl2, decreased correspondingly, thereby facilitating the cells to remain in the yeast form.
PubMed: 31947778
DOI: 10.3390/microorganisms8010075 -
Microbiological Research Nov 2019The in vitro inhibition of quorum sensing signal, xanthan gum secretion, biofilm formation in different Xanthomonas pathovars and biological control of bacterial blight...
The in vitro inhibition of quorum sensing signal, xanthan gum secretion, biofilm formation in different Xanthomonas pathovars and biological control of bacterial blight of rice by the two bioactive extrolites produced by Pseudomonas aeruginosa strain CGK-KS-1 were explored. These extrolites were extracted from Diaion HP-20 resin with methanol and purified by preparative-thin layer chromatography. Further, spectroscopic structural elucidation revealed the tentative identity of these extrolites to be (R,3E,5E,9Z,11E)-13-((3S,5R)-5-acetyl-2,6-dimethylheptan-3-yl)-10-hydroxy-4-methyl-1,8-diazabicyclo[9.3.1]pentadeca-3,5,9,11(15),13-pentaen-2-one and (R,3E,5E,8E,11E)-13-((3S,5R)-5-acetyl-2,6-dimethylheptan-3-yl)-4-methyl-1,8-diazabicyclo[9.3.1]pentadeca-3,5,8,11(15),13-pentaene-2,10-dione, named as Chumacin-1 and Chumacin-2, respectively. Antimicrobial assay showed Chumacin-1 and Chumacin-2 exhibited a strong in vitro growth inhibition against various Xanthomonas pathovars. Quorum sensing overlay assay using a reporter strain Chromobacterium violaceum strain CV026 showed that Chumacin-1 and Chumacin-2 inhibited quorum sensing signaling. The mechanistic studies revealed that these extrolites inhibited the production of quorum sensing signaling factor, cis-11-methyl-2-dodecenoic acid; suppressed the xanthan gum secretion and also inhibited the biofilms formed by various Xanthomonas pathovars. Both Chumacin-1 and Chumacin-2 showed ROS generation in the test Xanthomonas strains, resulting in in vitro cell membrane damage was revealed through CSLM and FE-SEM micrographs. Further, greenhouse experiments using Samba Mashuri (BPT-5204) revealed that seed treatment with Chumacin-1 and Chumacin-2 along with foliar spray groups showed up to ˜80% reduction in bacterial blight disease in rice. To the best of our knowledge, this is the first report on new quorum sensing inhibitors, Chumacin-1 and Chumacin-2 produced by Pseudomonas aeruginosa strain CGK-KS-1 exhibiting DSF inhibition activity in Xanthomonas oryzae pv. oryzae.
Topics: Anti-Infective Agents; Biofilms; Biological Control Agents; Chromobacterium; Microbial Sensitivity Tests; Molecular Docking Simulation; Oryza; Plant Diseases; Polysaccharides, Bacterial; Polystyrenes; Pseudomonas aeruginosa; Quorum Sensing; Signal Transduction; Xanthomonas
PubMed: 31422232
DOI: 10.1016/j.micres.2019.126301 -
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 -
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 -
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 -
Journal of Chemical Ecology Jan 2019Two heliozelid species, Antispila oinophylla van Nieukerken & Wagner and Holocacista rivillei (Stainton) severely infest Italian grapevines. The volatile pheromones from...
Two heliozelid species, Antispila oinophylla van Nieukerken & Wagner and Holocacista rivillei (Stainton) severely infest Italian grapevines. The volatile pheromones from calling females were collected by solid phase micro extraction (SPME) and analyzed by gas chromatography with electroantennographic detection (GC-EAD). Two compounds from A. oinophylla females eliciting electrophysiological activity from the conspecific male antenna were identified as (Z)-5-tetradecenal and (Z)-7-tetradecenal by coupled gas chromatography/mass spectrometry (GC/MS) analysis. SPME collections from H. rivillei produced no GC-EAD active compounds but analysis of fatty acyl moieties in the pheromone gland, demonstrated the presence of the putative pheromone biosynthetic precursors (Z)-5-dodecenoic acid and (Z)-7-tetradecenoic acid. Field trapping experiments in Italy confirmed that (Z)-5-tetradecenal and (Z)-7-tetradecenal are essential for the attraction of male A. oinophylla in a blend ratio of 15:100 respectively, whereas (Z)-5-dodecenal and (Z)-7-tetradecenal attract male H. rivillei in a blend ratio of 100:6.
Topics: Aldehydes; Animals; Female; Gas Chromatography-Mass Spectrometry; Lepidoptera; Male; Sex Attractants; Vitis
PubMed: 30547362
DOI: 10.1007/s10886-018-1036-z -
Environmental Science and Pollution... Sep 2018Pyrolysis of biodiesel at high temperatures may result in the formation of transient and stable free radicals immobilized on particulate emissions. Consequently, free...
Pyrolysis of biodiesel at high temperatures may result in the formation of transient and stable free radicals immobilized on particulate emissions. Consequently, free radicals adsorbed on particulates are believed to be precursors for health-related illnesses such as cancer, cardiac arrest, and oxidative stress. This study explores the nature of free radicals and particulate emissions generated when Croton megalocarpus biodiesel is pyrolyzed at 600 °C in an inert environment of flowing nitrogen at a residence time of 0.5 s at 1 atm. The surface morphology of thermal emissions were imaged using a field emission gun scanning electron microscope (FEG SEM) while the radical characteristics were investigated using an electron paramagnetic resonance spectrometer (EPR). A g-value of 2.0024 associated with a narrow ∆Hp-p of 3.65 G was determined. The decay rate constant for the radicals was low (1.86 × 10 s) while the half-life was long ≈ 431 days. The observed EPR characterization of Croton megalocarpus thermal particulates revealed the existence of free radicals typical of those found in coal. The low g-value and low decay rate constant suggests that the free radicals in particulates are possibly carbon-centered. The mechanistic channel for the formation of croton char from model biodiesel component (9-dodecenoic acid, methyl ester) has been proposed in this study.
Topics: Adsorption; Biofuels; Coal; Croton; Dust; Electron Spin Resonance Spectroscopy; Free Radicals; Half-Life; Particulate Matter; Vehicle Emissions
PubMed: 29926331
DOI: 10.1007/s11356-018-2546-5 -
A novel two-component system modulates quorum sensing and pathogenicity in Burkholderia cenocepacia.Molecular Microbiology Apr 2018Quorum sensing (QS) is widely utilized by bacterial pathogens to regulate biological functions and pathogenicity. Recent evidence has shown that QS is subject to...
Quorum sensing (QS) is widely utilized by bacterial pathogens to regulate biological functions and pathogenicity. Recent evidence has shown that QS is subject to regulatory cascades, especially two-component systems that often respond to environmental stimulation. At least two different types of QS systems regulate pathogenesis in Burkholderia cenocepacia. However, it remains unclear how this bacterial pathogen controls these QS systems. Here, we demonstrate a novel two-component system RqpSR (Regulating Quorum sensing and Pathogenicity), which plays an important role in modulating QS and pathogenesis in B. cenocepacia. We demonstrate strong protein-protein binding affinity between RqpS and RqpR. Mutations in rqpS and rqpR exerted overlapping effects on B. cenocepacia transcriptomes and phenotypes, including motility, biofilm formation and virulence. In trans expression of rqpR rescued the defective phenotypes in the rqpS mutant. RqpR controls target gene expression by direct binding to DNA promoters, including the cis-2-dodecenoic acid (BDSF) and N-acylhomoserine lactone (AHL) signal synthase gene promoters. These findings suggest that the RqpSR system strongly modulates physiology by forming a complicated hierarchy with QS systems. This type of two-component system appears to be widely distributed and coexists with the BDSF QS system in various bacterial species.
Topics: Amino Acid Sequence; Bacterial Proteins; Biofilms; Burkholderia cenocepacia; Cell Movement; Promoter Regions, Genetic; Protein Binding; Quorum Sensing; Sequence Deletion; Transcriptome; beta-Galactosidase
PubMed: 29363827
DOI: 10.1111/mmi.13915 -
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