Autoinducer-2 Triggers the Oxidative Stress Response in Mycobacterium avium, Leading to Biofilm Formation

ABSTRACT Mycobacterium avium is an environmental organism and opportunistic pathogen with inherent resistance to drugs, environmental stresses, and the host immune response. To adapt to these disparate conditions, M. avium must control its transcriptional response to environmental cues. M. avium forms biofilms in various environmental settings, including drinking water pipes and potable water reservoirs. In this study, we investigated the role of the universal signaling molecule autoinducer-2 (AI-2) in biofilm formation by M. avium. The addition of the compound to planktonic M. avium cultures resulted in increased biofilm formation. Microarray and reverse transcriptase PCR studies revealed an upregulation of the oxidative stress response upon addition of AI-2. This suggests that the response to AI-2 might be related to oxidative stress, rather than quorum sensing. Consistent with this model, addition of hydrogen peroxide, a known stimulus of the oxidative stress response, to M. avium cultures resulted in elevated biofilm formation. These results suggest that AI-2 does not act as a quorum-sensing signal in M. avium. Instead, biofilm formation is triggered by environmental stresses of biotic and abiotic origins and AI-2 may exert effects on that level.

Download Full-text

Ankrd2 in Mechanotransduction and Oxidative Stress Response in Skeletal Muscle: New Cues for the Pathogenesis of Muscular Laminopathies

Oxidative Medicine and Cellular Longevity ◽

10.1155/2019/7318796 ◽

2019 ◽

Vol 2019 ◽

pp. 1-15 ◽

Cited By ~ 6

Author(s):

Vittoria Cenni ◽

Snezana Kojic ◽

Cristina Capanni ◽

Georgine Faulkner ◽

Giovanna Lattanzi

Keyword(s):

Oxidative Stress ◽

Skeletal Muscle ◽

Stress Response ◽

Muscular Dystrophy ◽

Transcriptional Response ◽

Oxidative Stress Response ◽

Ankyrin Repeat ◽

Lamin A ◽

Cellular Reactive Oxygen Species ◽

Cardiac Muscles

Ankrd2 (ankyrin repeats containing domain 2) or Arpp (ankyrin repeat, PEST sequence, and proline-rich region) is a member of the muscle ankyrin repeat protein family. Ankrd2 is mostly expressed in skeletal muscle, where it plays an intriguing role in the transcriptional response to stress induced by mechanical stimulation as well as by cellular reactive oxygen species. Our studies in myoblasts from Emery-Dreifuss muscular dystrophy 2, a LMNA-linked disease affecting skeletal and cardiac muscles, demonstrated that Ankrd2 is a lamin A-binding protein and that mutated lamins found in Emery-Dreifuss muscular dystrophy change the dynamics of Ankrd2 nuclear import, thus affecting oxidative stress response. In this review, besides describing the latest advances related to Ankrd2 studies, including novel discoveries on Ankrd2 isoform-specific functions, we report the main findings on the relationship of Ankrd2 with A-type lamins and discuss known and potential mechanisms involving defective Ankrd2-lamin A interplay in the pathogenesis of muscular laminopathies.

Download Full-text

FurA contributes to the oxidative stress response regulation of Mycobacterium avium ssp. paratuberculosis

Frontiers in Microbiology ◽

10.3389/fmicb.2015.00016 ◽

2015 ◽

Vol 6 ◽

Cited By ~ 9

Author(s):

Elke Eckelt ◽

Thorsten MeiÃŸner ◽

Jochen Meens ◽

Kristin Laarmann ◽

Andreas Nerlich ◽

...

Keyword(s):

Oxidative Stress ◽

Stress Response ◽

Mycobacterium Avium ◽

Oxidative Stress Response

Download Full-text

Candida albicans quorum-sensing molecule farnesol modulates staphyloxanthin production and activates the thiol-based oxidative-stress response in Staphylococcus aureus

Virulence ◽

10.1080/21505594.2019.1635418 ◽

2019 ◽

Vol 10 (1) ◽

pp. 625-642 ◽

Cited By ~ 10

Author(s):

Taissa Vila ◽

Eric F. Kong ◽

Ahmed Ibrahim ◽

Kurt Piepenbrink ◽

Amol C. Shetty ◽

...

Keyword(s):

Oxidative Stress ◽

Staphylococcus Aureus ◽

Candida Albicans ◽

Stress Response ◽

Quorum Sensing ◽

Oxidative Stress Response ◽

Quorum Sensing Molecule

Download Full-text

Transcriptional Response of Leptospira interrogans to Iron Limitation and Characterization of a PerR Homolog

Infection and Immunity ◽

10.1128/iai.00435-10 ◽

2010 ◽

Vol 78 (11) ◽

pp. 4850-4859 ◽

Cited By ~ 54

Author(s):

Miranda Lo ◽

Gerald L. Murray ◽

Chen Ai Khoo ◽

David A. Haake ◽

Richard L. Zuerner ◽

...

Keyword(s):

Oxidative Stress ◽

Stress Response ◽

Iron Homeostasis ◽

Storage Proteins ◽

Iron Acquisition ◽

Bacterial Species ◽

Transcriptional Response ◽

Oxidative Stress Response ◽

Wild Type ◽

In The Wild

ABSTRACT Leptospirosis is a globally significant zoonosis caused by Leptospira spp. Iron is essential for growth of most bacterial species. Since iron availability is low in the host, pathogens have evolved complex iron acquisition mechanisms to survive and establish infection. In many bacteria, expression of iron uptake and storage proteins is regulated by Fur. L. interrogans encodes four predicted Fur homologs; we have constructed a mutation in one of these, la1857. We conducted microarray analysis to identify iron-responsive genes and to study the effects of la1857 mutation on gene expression. Under iron-limiting conditions, 43 genes were upregulated and 49 genes were downregulated in the wild type. Genes encoding proteins with predicted involvement in inorganic ion transport and metabolism (including TonB-dependent proteins and outer membrane transport proteins) were overrepresented in the upregulated list, while 54% of differentially expressed genes had no known function. There were 16 upregulated genes of unknown function which are absent from the saprophyte L. biflexa and which therefore may encode virulence-associated factors. Expression of iron-responsive genes was not significantly affected by mutagenesis of la1857, indicating that LA1857 is not a global regulator of iron homeostasis. Upregulation of heme biosynthetic genes and a putative catalase in the mutant suggested that LA1857 is more similar to PerR, a regulator of the oxidative stress response. Indeed, the la1857 mutant was more resistant to peroxide stress than the wild type. Our results provide insights into the role of iron in leptospiral metabolism and regulation of the oxidative stress response, including genes likely to be important for virulence.

Download Full-text

The bZIP Transcription Factor AflRsmA Regulates Aflatoxin B1 Biosynthesis, Oxidative Stress Response and Sclerotium Formation in Aspergillus flavus

Toxins ◽

10.3390/toxins12040271 ◽

2020 ◽

Vol 12 (4) ◽

pp. 271

Author(s):

Xiuna Wang ◽

Wenjie Zha ◽

Linlin Liang ◽

Opemipo Esther Fasoyin ◽

Lihan Wu ◽

...

Keyword(s):

Oxidative Stress ◽

Transcription Factor ◽

Stress Response ◽

Secondary Metabolites ◽

Secondary Metabolism ◽

Aspergillus Flavus ◽

Aflatoxin B1 ◽

Opportunistic Pathogen ◽

Oxidative Stress Response ◽

Bzip Transcription Factor

Fungal secondary metabolites play important roles not only in fungal ecology but also in humans living as beneficial medicine or harmful toxins. In filamentous fungi, bZIP-type transcription factors (TFs) are associated with the proteins involved in oxidative stress response and secondary metabolism. In this study, a connection between a bZIP TF and oxidative stress induction of secondary metabolism is uncovered in an opportunistic pathogen Aspergillus flavus, which produces carcinogenic and mutagenic aflatoxins. The bZIP transcription factor AflRsmA was identified by a homology research of A. flavus genome with the bZIP protein RsmA, involved in secondary metabolites production in Aspergillus nidulans. The AflrsmA deletion strain (ΔAflrsmA) displayed less sensitivity to the oxidative reagents tert-Butyl hydroperoxide (tBOOH) in comparison with wild type (WT) and AflrsmA overexpression strain (AflrsmAOE), while AflrsmAOE strain increased sensitivity to the oxidative reagents menadione sodium bisulfite (MSB) compared to WT and ΔAflrsmA strains. Without oxidative treatment, aflatoxin B1 (AFB1) production of ΔAflrsmA strains was consistent with that of WT, but AflrsmAOE strain produced more AFB1 than WT; tBOOH and MSB treatment decreased AFB1 production of ΔAflrsmA compared to WT. Besides, relative to WT, ΔAflrsmA strain decreased sclerotia, while AflrsmAOE strain increased sclerotia. The decrease of AFB1 by ΔAflrsmA but increase of AFB1 by AflrsmAOE was on corn. Our results suggest that AFB1 biosynthesis is regulated by AflRsmA by oxidative stress pathways and provide insights into a possible function of AflRsmA in mediating AFB1 biosynthesis response host defense in pathogen A. flavus.

Download Full-text

Deletion of the fungus specific protein phosphatase Z1 exaggerates the oxidative stress response in Candida albicans

BMC Genomics ◽

10.1186/s12864-019-6252-6 ◽

2019 ◽

Vol 20 (1) ◽

Cited By ~ 1

Author(s):

Krisztina Szabó ◽

Ágnes Jakab ◽

Szilárd Póliska ◽

Katalin Petrényi ◽

Katalin Kovács ◽

...

Keyword(s):

Oxidative Stress ◽

Candida Albicans ◽

Stress Response ◽

Protein Phosphatase ◽

Transcript Level ◽

Opportunistic Pathogen ◽

Sublethal Concentration ◽

Specific Protein ◽

Oxidative Stress Response ◽

Short Term Treatment

Abstract Background Candida albicans is an opportunistic pathogen which is responsible for widespread nosocomial infections. It encompasses a fungus specific serine/threonine protein phosphatase gene, CaPPZ1 that is involved in cation transport, cell wall integrity, oxidative stress response, morphological transition, and virulence according to the phenotypes of the cappz1 deletion mutant. Results We demonstrated that a short-term treatment with a sublethal concentration of tert-butyl hydroperoxide suppressed the growth of the fungal cells without affecting their viability, both in the cappz1 mutant and in the genetically matching QMY23 control strains. To reveal the gene expression changes behind the above observations we carried out a global transcriptome analysis. We used a pilot DNA microarray hybridization together with extensive RNA sequencing, and confirmed our results by quantitative RT-PCR. Novel functions of the CaPpz1 enzyme and oxidative stress mechanisms have been unraveled. The numbers of genes affected as well as the amplitudes of the transcript level changes indicated that the deletion of the phosphatase sensitized the response of C. albicans to oxidative stress conditions in important physiological functions like membrane transport, cell surface interactions, oxidation-reduction processes, translation and RNA metabolism. Conclusions We conclude that in the wild type C. albicans CaPPZ1 has a protective role against oxidative damage. We suggest that the specific inhibition of this phosphatase combined with mild oxidative treatment could be a feasible approach to topical antifungal therapy.

Download Full-text

Quorum Sensing Primes the Oxidative Stress Response in the Insect Endosymbiont, Sodalis glossinidius

PLoS ONE ◽

10.1371/journal.pone.0003541 ◽

2008 ◽

Vol 3 (10) ◽

pp. e3541 ◽

Cited By ~ 28

Author(s):

Mauricio H. Pontes ◽

Markus Babst ◽

Robert Lochhead ◽

Kelly Oakeson ◽

Kari Smith ◽

...

Keyword(s):

Oxidative Stress ◽

Stress Response ◽

Quorum Sensing ◽

Oxidative Stress Response ◽

Sodalis Glossinidius

Download Full-text

Candida albicans-Conditioned Medium Protects Yeast Cells from Oxidative Stress: a Possible Link between Quorum Sensing and Oxidative Stress Resistance

Eukaryotic Cell ◽

10.1128/ec.4.10.1654-1661.2005 ◽

2005 ◽

Vol 4 (10) ◽

pp. 1654-1661 ◽

Cited By ~ 91

Author(s):

Caroline Westwater ◽

Edward Balish ◽

David A. Schofield

Keyword(s):

Oxidative Stress ◽

Hydrogen Peroxide ◽

Candida Albicans ◽

Stress Response ◽

Quorum Sensing ◽

Conditioned Medium ◽

Oxidative Stress Response ◽

Yeast Cells ◽

Protective Response ◽

Quorum Sensing Molecule

ABSTRACT Candida albicans, the most frequent fungal pathogen of humans, encounters high levels of oxidants following ingestion by professional phagocytes and through contact with hydrogen peroxide-producing bacteria. In this study, we provide evidence that C. albicans is able to coordinately regulate the oxidative stress response at the global cell population level by releasing protective molecules into the surrounding medium. We demonstrate that conditioned medium, which is defined as a filter-sterilized supernatant from a C. albicans stationary-phase culture, is able to protect yeast cells from both hydrogen peroxide and superoxide anion-generating agents. Exponential-phase yeast cells preexposed to conditioned medium were able to survive levels of oxidative stress that would normally kill actively growing yeast cells. Heat treatment, digestion with proteinase K, pH adjustment, or the addition of the oxidant scavenger alpha-tocopherol did not alter the ability of conditioned medium to induce a protective response. Farnesol, a heat-stable quorum-sensing molecule (QSM) that is insensitive to proteolytic enzymes and is unaffected by pH extremes, is partly responsible for this protective response. In contrast, the QSM tyrosol did not alter the sensitivity of C. albicans cells to oxidants. Relative reverse transcription-PCR analysis indicates that Candida-conditioned growth medium induces the expression of CAT1, SOD1, SOD2, and SOD4, suggesting that protection may be mediated through the transcriptional regulation of antioxidant-encoding genes. Together, these data suggest a link between the quorum-sensing molecule farnesol and the oxidative stress response in C. albicans.

Download Full-text