Sequential activation of constitutive and inducible nitric oxide synthase (NOS) in rat cerebellar granule neurons by Pseudomonas fluorescens and invasive behaviour of the bacteria

Mezghani-Abdelmoula, Sana; Khemiri, Arbia; Lesouhaitier, Olivier; Chevalier, Sylvie; Orange, Nicole; Cazin, L.; Feuilloley, Marc

doi:10.1016/j.micres.2004.08.003

Cited by 11 publications

(11 citation statements)

References 22 publications

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“…Pseudomonas fluorescens is also characterised by a high and unexpected toxicity (George et al, 1999;Chapalain et al, 2008) and the virulence factors expressed by some strains may be particularly harmful in the CNS . In agreement with these observations, we have recently shown that P. fluorescens internalizes in granular neurons and induces morphological changes suggesting the induction of an apoptotic mechanism in nerve cells (Picot et al, 2001;Mezghani-Abdelmoula et al, 2004). Apoptosis involves major changes in the permeability of the plasma membrane of eukaryotic cells (Arabski et al, 2008).…”

Section: Introductionsupporting

confidence: 80%

“…This period correspond to a time at which we have maximum adherent bacteria on granule neurons as we have shown in previous studies (Mezghani-Abdelmoula et al, 2004). The resting membrane potential of neurons exhibiting adherent bacteria was significantly less negative than in control neurons, -46.0 ± 4.7 mV and -63.7 ± 2 mV respectively (n = 9, P < 0.001) (Fig.…”

Section: Effects Of Pseudomonas Fluorescens and Its Lps On The Restinsupporting

confidence: 74%

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Pseudomonas fluorescens alter whole-voltage-activated currents of cultured rat cerebellar granule neurons

et al. 2009

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-In the present study the effect of infection on the resting membrane potential and whole-voltage-activated currents of neurons was determined using Pseudomonas fluorescens and lipopolysaccharide (LPS) extracted from the same species. Electrophysiological studies were performed on cerebellar granule neurons using the whole cell configuration of the patch clamp technique. The resting potential of cells (-63.7 ± 2 mV) was significantly less negative (-46.0 ± 4.7 mV) in cells showing adherent bacteria (10 6 CFU/ml). In addition, the whole-voltage currents triggered by voltage pulses were markedly reduced in neurons incubated with P. fluorescens (mean 58%). Treatment with LPS (200 ng/ml) extracted from P. fluorescens provoke also a significant depolarisation of the membrane of the granule neurons and a severely alteration of whole-voltage currents. Analysis of the current-voltage relationships of the peak currents revealed the implication of potassium channels in the response of the cells to P. fluorescens and its LPS. The present report provides the first data on the effect of a living bacterium on the membrane electrical activity of neurons and comforts the recent observations of the high cytotoxic potential of P. fluorescens.

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Section: Introductionsupporting

confidence: 80%

Section: Effects Of Pseudomonas Fluorescens and Its Lps On The Restinsupporting

confidence: 74%

Pseudomonas fluorescens alter whole-voltage-activated currents of cultured rat cerebellar granule neurons

et al. 2009

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“…LDH is a stable eukaryotic enzyme considered as a marker of necrosis or non-specific cell death, whereas nitrite ions can be employed as markers of apoptosis, since they are generated by the spontaneous conversion of nitric oxide (NO) during eukaryotic cells apoptosis [25,33]. Whereas the release of LDH from glial cells exposed to GABA-treated bacteria was increased, the concentration of NO was significantly decreased.…”

Section: Discussionmentioning

confidence: 99%

“…The binding index of bacteria on biological (cell) surfaces was determined using the gentamicin exclusion test [33]. Glial cells were exposed to bacteria (10 6 CFU·mL −1 ) in culture medium without antibiotics and antimycotics for 4 h. At the end of the incubation period, cultures were rinsed 3 times with fresh medium to remove unattached bacteria.…”

Section: Methodsmentioning

confidence: 99%

Effect of GABA, a Bacterial Metabolite, on Pseudomonas fluorescens Surface Properties and Cytotoxicity

Dagorn

Chapalain

Mijouin

et al. 2013

IJMS

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Different bacterial species and, particularly Pseudomonas fluorescens, can produce gamma-aminobutyric acid (GABA) and express GABA-binding proteins. In this study, we investigated the effect of GABA on the virulence and biofilm formation activity of different strains of P. fluorescens. Exposure of a psychotropic strain of P. fluorescens (MF37) to GABA (10−5 M) increased its necrotic-like activity on eukaryotic (glial) cells, but reduced its apoptotic effect. Conversely, muscimol and bicuculline, the selective agonist and antagonist of eukaryote GABAA receptors, respectively, were ineffective. P. fluorescens MF37 did not produce biosurfactants, and its caseinase, esterase, amylase, hemolytic activity or pyoverdine productions were unchanged. In contrast, the effect of GABA was associated to rearrangements of the lipopolysaccharide (LPS) structure, particularly in the lipid A region. The surface hydrophobicity of MF37 was marginally modified, and GABA reduced its biofilm formation activity on PVC, but not on glass, although the initial adhesion was increased. Five other P. fluorescens strains were studied, and only one, MFP05, a strain isolated from human skin, showed structural differences of biofilm maturation after exposure to GABA. These results reveal that GABA can regulate the LPS structure and cytotoxicity of P. fluorescens, but that this property is specific to some strains.

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“…Apoptosis was measured by the accumulation of nitrite ions (NO 2 Ϫ ) in the incubation medium; nitrite ions result from the spontaneous conversion of nitric oxide (NO) following the activation and induction of apoptosis-dependent NO synthase activities (23). The concentration of NO 2 Ϫ was determined by using a technique derived from the Griess colorimetric reaction.…”

Section: Methodsmentioning

confidence: 99%

Gliding Arc Discharge in the Potato PathogenErwinia carotovorasubsp.atroseptica: Mechanism of Lethal Action and Effect on Membrane-Associated Molecules

Moreau

Feuilloley

Véron

et al. 2007

Appl Environ Microbiol

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. This prototype also decreases the required duration of treatment by 50%. The study of the time course effect of the process on bacterial morphology suggests that glidarc induces major alterations of the bacterial membrane. We showed that glidarc causes the release of bacterial genomic DNA. By contrast, an apparent decrease in the level of extractible lipopolysaccharide was observed; however, no changes in the electrophoretic pattern and cytotoxic activity of the macromolecule were noted. Analysis of extractible proteins from the outer membrane of the bacteria revealed that glidarc discharge induces the release of these proteins from the lipid environment, but may also be responsible for protein dimerization and/or aggregation. This effect was not observed in secreted enzymatic proteins, such as pectate lyase. Analysis of the data supports the hypothesis that the plasma generated by glidarc discharge is acting essentially through oxidative mechanisms. Furthermore, these results indicate that, in addition to effectively destroying bacteria, glidarc discharge should be used to improve the extraction of bacterial molecules.Industrial guidelines prescribing the use of nonchemical techniques of decontamination have evolved to avoid traces of antibacterial agents in the final product; consequently, this has encouraged research into physical techniques that kill bacteria, such as advanced oxidation processes.Systems based on electric discharge, especially those that generate nonthermal plasma, appear to be very promising because of their low equipment and energy costs, their efficiency on diverse surfaces or media, and even their possible application to heatsensitive materials (25). Producing nonthermal plasma requires specific conditions. Plasmas can be classified according to their energy level and proportion of light (electrons) and heavy species (e.g., molecules, atoms, radicals, and ions). Thermal plasmas, usually formed at high pressure (Ն1 atm), are media in which the energies of the two species are similarly high. By contrast, the mean energy of the electrons at low pressure is much higher than that of the heavy species, and the resulting plasma is designated "cold plasma." There are intermediate conditions at atmospheric pressure which allow for the formation of the nonthermal plasmas. Among the various techniques able to generate nonthermal plasma, we decided to study gliding arc, or "glidarc," discharge. We chose glidarc particularly because of its high industrial potential and its efficiency for decontamination. This technique was previously used for treating Escherichia coli (35), Staphylococcus epidermidis (4), and various species of the potato pathogen, Erwinia (26). Glidarc has been shown to totally destroy Erwinia carotovora subsp. atroseptica, Erwinia chrysanthemi, and Erwinia carotovora subsp. carotovora cultures (26). Bacterial killing using glidarc was achieved directly in the liquid medium at room temperature and was not accompanied by the formation of viable but noncultivable forms. However, thi...

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Sequential activation of constitutive and inducible nitric oxide synthase (NOS) in rat cerebellar granule neurons by Pseudomonas fluorescens and invasive behaviour of the bacteria

Cited by 11 publications

References 22 publications

Pseudomonas fluorescens alter whole-voltage-activated currents of cultured rat cerebellar granule neurons

Pseudomonas fluorescens alter whole-voltage-activated currents of cultured rat cerebellar granule neurons

Effect of GABA, a Bacterial Metabolite, on Pseudomonas fluorescens Surface Properties and Cytotoxicity

Gliding Arc Discharge in the Potato PathogenErwinia carotovorasubsp.atroseptica: Mechanism of Lethal Action and Effect on Membrane-Associated Molecules

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