scholarly journals Yersinia pseudotuberculosis mntH functions in intracellular manganese accumulation, which is essential for virulence and survival in cells expressing functional Nramp1

Microbiology ◽  
2011 ◽  
Vol 157 (4) ◽  
pp. 1115-1122 ◽  
Author(s):  
Olivia L. Champion ◽  
Andrey Karlyshev ◽  
Ian A. M. Cooper ◽  
Donna C. Ford ◽  
Brendan W. Wren ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Respiratory Burst ◽  
Yersinia Pseudotuberculosis ◽  
Galleria Mellonella ◽  
Bacterial Pathogens ◽  
Reactive Oxygen ◽  
Intracellular Survival ◽  
Null Mutation ◽  
Oxygen Species ◽  
Survival And Growth

Manganese has an important yet undefined role in the virulence of many bacterial pathogens. In this study we confirm that a null mutation in Yersinia pseudotuberculosis mntH reduces intracellular manganese accumulation. An mntH mutant was susceptible to killing by reactive oxygen species when grown under manganese-limited conditions. The mntH mutant was defective in survival and growth in macrophages expressing functional Nramp1, but in macrophages deficient in Nramp the bacteria were able to survive and replicate. In Galleria mellonella, the mntH mutant was attenuated. Taken together, these data suggest a role for manganese in Y. pseudotuberculosis during macrophage intracellular survival, protecting the bacteria from the antimicrobial products released during the respiratory burst.

scholarly journals The Arabidopsis RboHB Encoded by At1g09090 Is Important for Resistance against Nematodes

2020 ◽  
Vol 21 (15) ◽  
pp. 5556 ◽  
Author(s):  
Abdalmenem I. M. Hawamda ◽  
Adil Zahoor ◽  
Amjad Abbas ◽  
Muhammad Amjad Ali ◽  
Holger Bohlmann
Keyword(s):  
Reactive Oxygen Species ◽  
Respiratory Burst ◽  
Reactive Oxygen ◽  
Heterodera Schachtii ◽  
Oxygen Species ◽  
Cyst Nematodes ◽  
Feeding Site ◽  
Plant Life ◽  
Respiratory Burst Oxidase ◽  
Respiratory Burst Oxidase Homologue

Reactive oxygen species are a byproduct of aerobic metabolic processes but are also produced by plants in defense against pathogens. In addition, they can function as signaling molecules that control various aspects of plant life, ranging from developmental processes to responses to abiotic and biotic stimuli. In plants, reactive oxygen species can be produced by respiratory burst oxidase homologues. Arabidopsis contains 10 genes for respiratory burst oxidase homologues that are involved in different aspects of plant life. Plant pathogenic cyst nematodes such as Heterodera schachtii induce a syncytium in the roots of host plants that becomes a feeding site which supplies nutrients throughout the life of the nematode. In line with this function, the transcriptome of the syncytium shows drastic changes. One of the genes that is most strongly downregulated in syncytia codes for respiratory burst oxidase homologue B. This gene is root-specific and we confirm here the downregulation in nematode feeding sites with a promoter::GUS (β-glucuronidase) line. Overexpression of this gene resulted in enhanced resistance against nematodes but also against leaf-infecting pathogens. Thus, respiratory burst oxidase homologue B has a role in resistance. The function of this gene is in contrast to respiratory burst oxidase homologues D and F, which have been found to be needed for full susceptibility of Arabidopsis to H. schachtii. However, our bioinformatic analysis did not find differences between these proteins that could account for the opposed function in the interaction with nematodes.

Effects of raspberry fruit extracts and ellagic acid on respiratory burst in murine macrophages

2014 ◽  
Vol 5 (6) ◽  
pp. 1167-1174 ◽  
Author(s):  
Lina Raudone ◽  
Ramune Bobinaite ◽  
Valdimaras Janulis ◽  
Pranas Viskelis ◽  
Sonata Trumbeckaite
Keyword(s):  
Reactive Oxygen Species ◽  
Respiratory Burst ◽  
Ellagic Acid ◽  
Reactive Oxygen Species Production ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Murine Macrophages ◽  
Fruit Extracts ◽  
Species Production

The main finding of our study is that raspberry extracts and ellagic acid inhibit reactive oxygen species production in PMA stimulated macrophages.

scholarly journals Alteration of Neutrophil Reactive Oxygen Species Production by Extracts of Devil’s Claw (Harpagophytum)

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Mbaki Muzila ◽  
Kimmo Rumpunen ◽  
Helen Wright ◽  
Helen Roberts ◽  
Melissa Grant ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Respiratory Burst ◽  
Dna Analysis ◽  
Reactive Oxygen ◽  
Human Neutrophils ◽  
Putative Hybrid ◽  
Oxygen Species ◽  
New Variety ◽  
Devil’S Claw ◽  
Anti Inflammatory

Harpagophytum, Devil’s Claw, is a genus of tuberiferous xerophytic plants native to southern Africa. Some of the taxa are appreciated for their medicinal effects and have been traditionally used to relieve symptoms of inflammation. The objectives of this pilot study were to investigate the antioxidant capacity and the content of total phenols, verbascoside, isoverbascoside, and selected iridoids, as well as to investigate the capacity of variousHarpagophytumtaxa in suppressing respiratory burst in terms of reactive oxygen species produced by human neutrophils challenged with phorbol myristate acetate (PMA), opsonisedStaphylococcus aureus,andFusobacterium nucleatum.Harpagophytumplants were classified into different taxa according to morphology, and DNA analysis was used to confirm the classification. A putative new variety ofH. procumbensshowed the highest degree of antioxidative capacity. Using PMA, threeHarpagophytumtaxa showed anti-inflammatory effects with regard to the PBS control. A putative hybrid betweenH. procumbensandH. zeyheriin contrast showed proinflammatory effect on the response of neutrophils toF. nucleatumin comparison with treatment with vehicle control.Harpagophytumtaxa were biochemically very variable and the response in suppressing respiratory burst differed. Further studies with larger number of subjects are needed to corroborate anti-inflammatory effects of different taxa ofHarpagophytum.

Surfactant protein A modulates release of reactive oxygen species from alveolar macrophages

1994 ◽  
Vol 267 (6) ◽  
pp. L660-L666 ◽  
Author(s):  
S. Weissbach ◽  
A. Neuendank ◽  
M. Pettersson ◽  
T. Schaberg ◽  
U. Pison
Keyword(s):  
Reactive Oxygen Species ◽  
Respiratory Burst ◽  
Protein A ◽  
Reactive Oxygen ◽  
Surfactant Protein ◽  
Oxygen Radical ◽  
Surfactant Protein A ◽  
Oxygen Species ◽  
Coated Surfaces

The production and release of reactive oxygen species (the respiratory burst) is a common metabolic pathway linked to several macrophage-related reactions. The most abundant surfactant protein A (SP-A) binds to alveolar macrophages (AM) through a specific surface receptor with high affinity. Because such binding might initiate or modulate the respiratory burst, we wanted to know whether and how SP-A affects the oxygen radical release from AM. To answer these questions, we measured the release of reactive oxygen species from rat AM under various in vitro conditions using enhanced chemiluminescence systems. We prepared SP-A from pulmonary surfactant isolated either from silica-treated rats or adult dogs. Resident AM were harvested from pathogen-free Wistar rats by lung lavage. Adhered and nonadhered AM were assessed on protein-free or protein-coated surfaces of 96-well microtiter plates. On protein-free surfaces, the sole addition of SP-A failed to induce measurable oxygen radical release from 2 x 10(5) adhered or nonadhered AM, while zymosan opsonized with SP-A induced a marked increase over control. On protein-coated surfaces, AM respond differently depending on the coated protein: on SP-A-coated surfaces, a dose-dependent enhancement of oxygen radical release with a mean effective concentration of approximately 1.15 micrograms/ml was found. No such enhancement was seen on plates coated with similar amounts of either human fibronectin or collagen, and the enhancement with serum albumin was not dose related. Our data demonstrate that SP-A only enhances oxygen radical release from AM if SP-A is fixed to zymosan or the surface of the reaction vial in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Fis Is Essential for Yersinia pseudotuberculosis Virulence and Protects against Reactive Oxygen Species Produced by Phagocytic Cells during Infection

2016 ◽  
Vol 12 (9) ◽  
pp. e1005898 ◽  
Author(s):  
Erin R. Green ◽  
Stacie Clark ◽  
Gregory T. Crimmins ◽  
Matthias Mack ◽  
Carol A. Kumamoto ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Yersinia Pseudotuberculosis ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Phagocytic Cells
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