Melanin Protects Paracoccidioides brasiliensis from the Effects of Antimicrobial Photodynamic Inhibition and Antifungal Drugs

ABSTRACTParacoccidioidomycosis (PCM) is a public health concern in Latin America and South America that when not correctly treated can lead to patient death. In this study, the influence of melanin produced byParacoccidioidesspp. on the effects of treatment with antimicrobial photodynamic inhibition (aPI) and antifungal drugs was evaluated. aPI was performed using toluidine blue (TBO) as a photosensitizer and a 630-nm light-emitting diode (LED) light. The antifungals tested were itraconazole and amphotericin B. We evaluated the effects of each approach, aPI or antifungals, against nonmelanized and melanized yeast cells by performing susceptibility tests and by quantifying oxidative and nitrosative bursts during the experiments. aPI reduced nonmelanized cells by 3.0 log units and melanized cells by 1.3 log units. The results showed that melanization protects the fungal cell, probably by acting as a scavenger of nitric oxide and reactive oxygen species, but not of peroxynitrite. Melanin also increased the MICs of itraconazole and amphotericin B, and the drugs were fungicidal for nonmelanized and fungistatic for melanized yeast cells. Our study shows that melanin production byParacoccidioidesyeast cells serves a protective function during aPI and treatment with itraconazole and amphotericin B. The results suggest that melanin binds to the drugs, changing their antifungal activities, and also acts as a scavenger of reactive oxygen species and nitric oxide, but not of peroxynitrite, indicating that peroxynitrite is the main radical that is responsible for fungal death after aPI.

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Induction of Mitochondrial Reactive Oxygen Species Production by Itraconazole, Terbinafine, and Amphotericin B as a Mode of Action against Aspergillus fumigatus

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00978-17 ◽

2017 ◽

Vol 61 (11) ◽

Cited By ~ 23

Author(s):

Elena Shekhova ◽

Olaf Kniemeyer ◽

Axel A. Brakhage

Keyword(s):

Reactive Oxygen Species ◽

Lipid Peroxidation ◽

Aspergillus Fumigatus ◽

Amphotericin B ◽

Complex I ◽

Reactive Oxygen ◽

Antifungal Compounds ◽

Ros Production ◽

Oxygen Species ◽

Content Type

ABSTRACT Drug resistance in fungal pathogens is of incredible importance to global health, yet the mechanisms of drug action remain only loosely defined. Antifungal compounds have been shown to trigger the intracellular accumulation of reactive oxygen species (ROS) in human-pathogenic yeasts, but the source of those ROS remained unknown. In the present study, we examined the role of endogenous ROS for the antifungal activity of the three different antifungal substances itraconazole, terbinafine, and amphotericin B, which all target the fungal cell membrane. All three antifungals had an impact on fungal redox homeostasis by causing increased intracellular ROS production. Interestingly, the elevated ROS levels induced by antifungals were abolished by inhibition of the mitochondrial respiratory complex I with rotenone. Further, evaluation of lipid peroxidation using the thiobarbituric acid assay revealed that rotenone pretreatment decreased ROS-induced lipid peroxidation during incubation of Aspergillus fumigatus with itraconazole and terbinafine. By applying the mitochondrion-specific lipid peroxidation probe MitoPerOx, we also confirmed that ROS are induced in mitochondria and subsequently cause significant oxidation of mitochondrial membrane in the presence of terbinafine and amphotericin B. To summarize, our study suggests that the induction of ROS production contributes to the ability of antifungal compounds to inhibit fungal growth. Moreover, mitochondrial complex I is the main source of deleterious ROS production in A. fumigatus challenged with antifungal compounds.

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The Production of Reactive Oxygen Species Is a Universal Action Mechanism of Amphotericin B against Pathogenic Yeasts and Contributes to the Fungicidal Effect of This Drug

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.03570-14 ◽

2014 ◽

Vol 58 (11) ◽

pp. 6627-6638 ◽

Cited By ~ 83

Author(s):

Ana Cecilia Mesa-Arango ◽

Nuria Trevijano-Contador ◽

Elvira Román ◽

Ruth Sánchez-Fresneda ◽

Celia Casas ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Amphotericin B ◽

Reactive Oxygen ◽

Mitochondrial Respiratory Chain ◽

Oxygen Species ◽

Action Mechanism ◽

Pathogenic Yeast ◽

Content Type ◽

Fungicidal Effect ◽

Killing Action

ABSTRACTAmphotericin B (AMB) is an antifungal drug that binds to ergosterol and forms pores at the cell membrane, causing the loss of ions. In addition, AMB induces the accumulation of reactive oxygen species (ROS), and although these molecules have multiple deleterious effects on fungal cells, their specific role in the action mechanism of AMB remains unknown. In this work, we studied the role of ROS in the action mechanism of AMB. We determined the intracellular induction of ROS in 44 isolates of different pathogenic yeast species (Candida albicans,Candida parapsilosis,Candida glabrata,Candida tropicalis,Candida krusei,Cryptococcus neoformans, andCryptococcus gattii). We also characterized the production of ROS in AMB-resistant isolates. We found that AMB induces the formation of ROS in all the species tested. The inhibition of the mitochondrial respiratory chain by rotenone blocked the induction of ROS by AMB and provided protection from the killing action of the antifungal. Moreover, this phenomenon was absent in strains that displayed resistance to AMB. These strains showed an alteration in the respiration rate and mitochondrial membrane potential and also had higher catalase activity than that of the AMB-susceptible strains. Consistently, AMB failed to induce protein carbonylation in the resistant strains. Our data demonstrate that the production of ROS by AMB is a universal and important action mechanism that is correlated with the fungicidal effect and might explain the low rate of resistance to the molecule. Finally, these data provide an opportunity to design new strategies to improve the efficacy of this antifungal.

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Chlamydia muridarum Infection of Macrophages Elicits Bactericidal Nitric Oxide Production via Reactive Oxygen Species and Cathepsin B

Infection and Immunity ◽

10.1128/iai.00382-15 ◽

2015 ◽

Vol 83 (8) ◽

pp. 3164-3175 ◽

Cited By ~ 24

Author(s):

Krithika Rajaram ◽

David E. Nelson

Keyword(s):

Nitric Oxide ◽

Reactive Oxygen Species ◽

Cathepsin B ◽

Defense Mechanisms ◽

Reactive Oxygen ◽

Host Protein ◽

Radical Scavenger ◽

Oxygen Species ◽

Content Type ◽

Chlamydia Muridarum

The ability of certain species ofChlamydiato inhibit the biogenesis of phagolysosomes permits their survival and replication within macrophages. The survival of macrophage-adapted chlamydiae correlates with the multiplicity of infection (MOI), and optimal chlamydial growth occurs in macrophages infected at an MOI of ≤1. In this study, we examined the replicative capacity ofChlamydia muridarumin the RAW 264.7 murine macrophage cell line at different MOIs.C. muridarumproductively infected these macrophages at low MOIs but yielded few viable elementary bodies (EBs) when macrophages were infected at a moderate (10) or high (100) MOI. While high MOIs caused cytotoxicity and irreversible host cell death, macrophages infected at a moderate MOI did not show signs of cytotoxicity until late in the infectious cycle. Inhibition of host protein synthesis rescuedC. muridarumin macrophages infected at a moderate MOI, implying that chlamydial growth was blocked by activated defense mechanisms. Conditioned medium from these macrophages was antichlamydial and contained elevated levels of interleukin 1β (IL-1β), IL-6, IL-10, and beta interferon (IFN-β). Macrophage activation depended on Toll-like receptor 2 (TLR2) signaling, and cytokine production required live, transcriptionally active chlamydiae. A hydroxyl radical scavenger and inhibitors of inducible nitric oxide synthase (iNOS) and cathepsin B also reversed chlamydial killing. High levels of reactive oxygen species (ROS) led to an increase in cathepsin B activity, and pharmacological inhibition of ROS and cathepsin B reduced iNOS expression. Our data demonstrate that MOI-dependent TLR2 activation of macrophages results in iNOS induction via a novel ROS- and cathepsin-dependent mechanism to facilitateC. muridarumclearance.

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Faculty Opinions recommendation of Sources of vascular nitric oxide and reactive oxygen species and their regulation

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.734520172.793578224 ◽

2020 ◽

Author(s):

Paschalis-Thomas Doulias

Keyword(s):

Nitric Oxide ◽

Reactive Oxygen Species ◽

Reactive Oxygen ◽

Oxygen Species

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The Role of Reactive Oxygen Species, Kinases, Hydrogen Sulfide, and Nitric Oxide in the Regulation of Autophagy and Their Impact on Ischemia and Reperfusion Injury in the Heart

Current Cardiology Reviews ◽

10.2174/1573403x16666201014142446 ◽

2020 ◽

Vol 16 ◽

Author(s):

Andrey Krylatov ◽

Leonid Maslov ◽

Sergey Y. Tsibulnikov ◽

Nikita Voronkov ◽

Alla Boshchenko ◽

...

Keyword(s):

Nitric Oxide ◽

Reactive Oxygen Species ◽

Hydrogen Sulfide ◽

Ischemia Reperfusion ◽

Reactive Oxygen ◽

Ischemia And Reperfusion ◽

Oxygen Species ◽

Ischemia And Reperfusion Injury ◽

Adaptive Process

: There is considerable evidence in the heart that autophagy in cardiomyocytes is activated by hypoxia/reoxygenation (H/R) or in hearts by ischemia/reperfusion (I/R). Depending upon the experimental model and duration of ischemia, increases in autophagy in this setting maybe beneficial (cardioprotective) or deleterious (exacerbate I/R injury). Aside from the conundrum as to whether or not autophagy is an adaptive process, it is clearly regulated by a number of diverse molecules including reactive oxygen species (ROS), various kinases, hydrogen sulfide (H2S) and nitric oxide (NO). The purpose this review is to address briefly the controversy regarding the role of autophagy in this setting and to examine a variety of disparate molecules that are involved in its regulation.

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Plasmonic Enhancement of Nitric Oxide Generation

Nanoscale ◽

10.1039/d1nr02126e ◽

2021 ◽

Author(s):

Rachael Knoblauch ◽

Chris Geddes

Keyword(s):

Nitric Oxide ◽

Reactive Oxygen Species ◽

Reactive Nitrogen Species ◽

Reactive Oxygen ◽

Reactive Nitrogen ◽

Oxygen Species ◽

Nitrogen Species ◽

Plasmonic Enhancement ◽

Cancer Treatments

While the utility of reactive oxygen species in photodynamic therapies for both cancer treatments and antimicrobial applications has received much attention, the inherent potential of reactive nitrogen species (RNS) including...

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Reactive Oxygen Species-Dependent Nitric Oxide Production in Reciprocal Interactions of Glioma and Microglial Cells

Journal of Cellular Physiology ◽

10.1002/jcp.24659 ◽

2014 ◽

Vol 229 (12) ◽

pp. 2015-2026 ◽

Cited By ~ 21

Author(s):

Shing-Chuan Shen ◽

Ming-Shun Wu ◽

Hui-Yi Lin ◽

Liang-Yo Yang ◽

Yi-Hsuan Chen ◽

...

Keyword(s):

Nitric Oxide ◽

Reactive Oxygen Species ◽

Reactive Oxygen ◽

Microglial Cells ◽

Nitric Oxide Production ◽

Oxygen Species ◽

Reciprocal Interactions ◽

Oxide Production

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The role of oxidative/nitrosative stress in pathogenesis of paracetamol-induced toxic hepatitis

Medicinski pregled ◽

10.2298/mpns1012827r ◽

2010 ◽

Vol 63 (11-12) ◽

pp. 827-832 ◽

Cited By ~ 7

Author(s):

Tatjana Radosavljevic ◽

Dusan Mladenovic ◽

Danijela Vucevic ◽

Rada Jesic-Vukicevic

Keyword(s):

Oxidative Stress ◽

Nitric Oxide ◽

Reactive Oxygen Species ◽

Liver Injury ◽

Kupffer Cells ◽

Reactive Oxygen ◽

Oxygen Species ◽

Severe Liver ◽

Hepatocellular Necrosis

Introduction. Paracetamol is an effective analgesic/antipyretic drug when used at therapeutic doses. However, the overdose of paracetamol can cause severe liver injury and liver necrosis. The mechanism of paracetamol-induced liver injury is still not completely understood. Reactive metabolite formation, depletion of glutathione and alkylation of proteins are the triggers of inhibition of mitochondrial respiration, adenosine triphosphate depletion and mitochondrial oxidant stress leading to hepatocellular necrosis. Role of oxidative stress in paracetamol-induced liver injury. The importance of oxidative stress in paracetamol hepatotoxicity is controversial. Paracetamol induced liver injury cause the formation of reactive oxygen species. The potent sources of reactive oxygen are mitochondria, neutrophils, Kupffer cells and the enzyme xatnine oxidase. Free radicals lead to lipid peroxidation, enzymatic inactivation and protein oxidation. Role of mitochondria in paracetamol-induced oxidative stress. The production of mitochondrial reactive oxygen species is increased, and the glutathione content is decreased in paracetamol overdose. Oxidative stress in mitochondria leads to mito?chondrial dysfunction with adenosine triphosphate depletion, increase mitochondrial permeability transition, deoxyribonu?cleic acid fragmentation which contribute to the development of hepatocellular necrosis in the liver after paracetamol overdose. Role of Kupffer cells in paracetamol-induced liver injury. Paracetamol activates Kupffer cells, which then release numerous cytokines and signalling molecules, including nitric oxide and superoxide. Kupffer cells are important in peroxynitrite formation. On the other hand, the activated Kupffer cells release anti-inflammatory cytokines. Role of neutrophils in paracetamol-induced liver injury. Paracetamol-induced liver injury leads to the accumulation of neutrophils, which release lysosomal enzymes and generate superoxide anion radicals through the enzyme nicotinamide adenine dinucleotide phosphate oxidase. Hydrogen peroxide, which is influenced by the neutrophil-derived enzyme myeloperoxidase, generates hypochlorus acid as a potent oxidant. Role of peroxynitrite in paracetamol-induced oxidative stress. Superoxide can react with nitric oxide to form peroxynitrite, as a potent oxidant. Nitrotyrosine is formed by the reaction of tyrosine with peroxynitrite in paracetamol hepatotoxicity. Conclusion. Overdose of paracetamol may produce severe liver injury with hepatocellular necrosis. The most important mechanisms of cell injury are metabolic activation of paracetamol, glutathione depletion, alkylation of proteins, especially mitochondrial proteins, and formation of reactive oxygen/nitrogen species.

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