scholarly journals Rotenone Enhances the Antifungal Properties of Staurosporine

2010 ◽  
Vol 9 (6) ◽  
pp. 906-914 ◽  
Author(s):  
Ana Castro ◽  
Catarina Lemos ◽  
Artur Falcão ◽  
Andreia S. Fernandes ◽  
N. Louise Glass ◽  
...  
Keyword(s):  
Cell Death ◽  
Antifungal Activity ◽  
Complex I ◽  
Specific Inhibitor ◽  
Fungal Growth ◽  
Chain Complex ◽  
Glutathione Depletion ◽  
Oxygen Species ◽  
Content Type ◽  
The Common

ABSTRACT We studied staurosporine-induced cell death in the filamentous fungus Neurospora crassa. The generation of reactive oxygen species during the process appears to be an important signaling event, since addition of the antioxidant glutathione prevents the effects of staurosporine on fungal growth. Selected mutants with mutations in respiratory chain complex I are extremely sensitive to the drug, stressing the involvement of complex I in programmed cell death. Following this finding, we determined that the complex I-specific inhibitor rotenone used in combination with staurosporine results in a synergistic and specific antifungal activity, likely through a concerted action on intracellular glutathione depletion. Paradoxically, the synergistic antifungal activity of rotenone and staurosporine is observed in N. crassa complex I mutants and in Saccharomyces cerevisiae, which lacks complex I. In addition, it is not observed when other complex I inhibitors are used instead of rotenone. These results indicate that the rotenone effect is independent of complex I inhibition. The combination of rotenone and staurosporine is effective against N. crassa as well as against the common pathogens Aspergillus fumigatus and Candida albicans, pointing to its usefulness as an antifungal agent.

scholarly journals Dimethyl Sulfoxide Protects Escherichia coli from Rapid Antimicrobial-Mediated Killing

2016 ◽  
Vol 60 (8) ◽  
pp. 5054-5058 ◽  
Author(s):  
Hongfei Mi ◽  
Dai Wang ◽  
Yunxin Xue ◽  
Zhi Zhang ◽  
Jianjun Niu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Reactive Oxygen Species ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Dimethyl Sulfoxide ◽  
Oxygen Species ◽  
Content Type ◽  
Antimicrobial Studies ◽  
Ros Accumulation ◽  
Short Time

ABSTRACTThe contribution of reactive oxygen species (ROS) to antimicrobial lethality was examined by treatingEscherichia coliwith dimethyl sulfoxide (DMSO), an antioxidant solvent frequently used in antimicrobial studies. DMSO inhibited killing by ampicillin, kanamycin, and two quinolones and had little effect on MICs. DMSO-mediated protection correlated with decreased ROS accumulation and provided evidence for ROS-mediated programmed cell death. These data support the contribution of ROS to antimicrobial lethality and suggest caution when using DMSO-dissolved antimicrobials for short-time killing assays.

scholarly journals Streptococcus oralis Induces Lysosomal Impairment of Macrophages via Bacterial Hydrogen Peroxide

2016 ◽  
Vol 84 (7) ◽  
pp. 2042-2050 ◽  
Author(s):  
Nobuo Okahashi ◽  
Masanobu Nakata ◽  
Hirotaka Kuwata ◽  
Shigetada Kawabata
Keyword(s):  
Hydrogen Peroxide ◽  
Cell Death ◽  
Cathepsin B ◽  
Opportunistic Infections ◽  
Specific Inhibitor ◽  
Fluorescent Labeling ◽  
Dependent Manner ◽  
Content Type ◽  
Acridine Orange Staining ◽  
Streptococcus Oralis

Streptococcus oralis, an oral commensal, belongs to the mitis group of streptococci and occasionally causes opportunistic infections, such as bacterial endocarditis and bacteremia. Recently, we found that the hydrogen peroxide (H2O2) produced byS. oralisis sufficient to kill human monocytes and epithelial cells, implying that streptococcal H2O2is a cytotoxin. In the present study, we investigated whether streptococcal H2O2impacts lysosomes, organelles of the intracellular digestive system, in relation to cell death.S. oralisinfection induced the death of RAW 264 macrophages in an H2O2-dependent manner, which was exemplified by the fact that exogenous H2O2also induced cell death. Infection with either a mutant lackingspxB, which encodes pyruvate oxidase responsible for H2O2production, orStreptococcus mutans, which does not produce H2O2, showed less cytotoxicity. Visualization of lysosomes with LysoTracker revealed lysosome deacidification after infection withS. oralisor exposure to H2O2, which was corroborated by acridine orange staining. Similarly, fluorescent labeling of lysosome-associated membrane protein-1 gradually disappeared during infection withS. oralisor exposure to H2O2. The deacidification and the following induction of cell death were inhibited by chelating iron in lysosomes. Moreover, fluorescent staining of cathepsin B indicated lysosomal destruction. However, treatment of infected cells with a specific inhibitor of cathepsin B had negligible effects on cell death; instead, it suppressed the detachment of dead cells from the culture plates. These results suggest that streptococcal H2O2induces cell death with lysosomal destruction and then the released lysosomal cathepsins contribute to the detachment of the dead cells.

scholarly journals Characterization of Antifungal Activity and Nail Penetration of ME1111, a New Antifungal Agent for Topical Treatment of Onychomycosis

2015 ◽  
Vol 60 (2) ◽  
pp. 1035-1039 ◽  
Author(s):  
Yuji Tabata ◽  
Naomi Takei-Masuda ◽  
Natsuki Kubota ◽  
Sho Takahata ◽  
Makoto Ohyama ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Antifungal Agent ◽  
Fungal Growth ◽  
Trichophyton Mentagrophytes ◽  
Dependent Manner ◽  
Content Type ◽  
Etiologic Agents ◽  
Prevalent Disease ◽  
Penetration Ability

ABSTRACTFungal nail infection (onychomycosis) is a prevalent disease in many areas of the world, with a high incidence approaching 23%. Available antifungals to treat the disease suffer from a number of disadvantages, necessitating the discovery of new efficacious and safe antifungals. Here, we evaluate thein vitroantifungal activity and nail penetration ability of ME1111, a novel antifungal agent, along with comparator drugs, including ciclopirox, amorolfine, terbinafine, and itraconazole. ME1111 showed potent antifungal activity againstTrichophyton rubrumandTrichophyton mentagrophytes(the major etiologic agents of onychomycosis) strains isolated in Japan and reference fungal strains with an MIC range of 0.12 to 0.5 mg/liter and an MIC50and MIC90of 0.5 mg/liter for both. Importantly, none of the tested isolates showed an elevated ME1111 MIC. Moreover, the antifungal activity of ME1111 was minimally affected by 5% wool keratin powder in comparison to the other antifungals tested. The ME1111 solution was able to penetrate human nails and inhibit fungal growth in a dose-dependent manner according to the TurChub assay. In contrast, 8% ciclopirox and 5% amorolfine nail lacquers showed no activity under the same conditions. ME1111 demonstrated approximately 60-fold-greater selectivity in inhibition ofTrichophyton spp. than of human cell lines. Our findings demonstrate that ME1111 possesses potent antidermatophyte activity, maintains this activity in the presence of keratin, and possesses excellent human nail permeability. These results suggest that ME1111 is a promising topical medication for the treatment of onychomycosis and therefore warrants further clinical evaluation.

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

2017 ◽  
Vol 61 (11) ◽  
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.

scholarly journals Sirtuin 3 Downregulation in Mycobacterium tuberculosis-Infected Macrophages Reprograms Mitochondrial Metabolism and Promotes Cell Death

mBio ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lorissa J. Smulan ◽  
Nuria Martinez ◽  
Michael C. Kiritsy ◽  
Chido Kativhu ◽  
Kelly Cavallo ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Mycobacterium Tuberculosis ◽  
Mitochondrial Metabolism ◽  
Metabolic Reprogramming ◽  
Oxygen Species ◽  
Bacterial Burden ◽  
Sirtuin 3 ◽  
Content Type ◽  
Important Regulator

ABSTRACT Mycobacterium tuberculosis induces metabolic reprogramming in macrophages like the Warburg effect. This enhances antimicrobial performance at the expense of increased inflammation, which may promote a pathogen-permissive host environment. Since the NAD+-dependent protein deacetylase Sirtuin 3 (SIRT3) is an important regulator of mitochondrial metabolism and cellular redox homeostasis, we hypothesized that SIRT3 modulation mediates M. tuberculosis-induced metabolic reprogramming. Infection of immortalized and primary murine macrophages resulted in reduced levels of SIRT3 mRNA and protein and perturbation of SIRT3-regulated enzymes in the tricarboxylic acid cycle, electron transport chain, and glycolytic pathway. These changes were associated with increased reactive oxygen species and reduced antioxidant scavenging, thereby triggering mitochondrial stress and macrophage cell death. Relevance to tuberculosis disease in vivo was indicated by greater bacterial burden and immune pathology in M. tuberculosis-infected Sirt3−/− mice. CD11b+ lung leukocytes isolated from infected Sirt3−/− mice showed decreased levels of enzymes involved in central mitochondrial metabolic pathways, along with increased reactive oxygen species. Bacterial burden was also greater in lungs of LysMcreSirt3L2/L2 mice, demonstrating the importance of macrophage-specific SIRT3 after infection. These results support the model of SIRT3 as a major upstream regulatory factor, leading to metabolic reprogramming in macrophages by M. tuberculosis. IMPORTANCE Tuberculosis, the disease caused by the bacterium M. tuberculosis, remains one of the top 10 causes of death worldwide. Macrophages, the first cells to encounter M. tuberculosis and critical for defense against infection, are hijacked by M. tuberculosis as a protected growth niche. M. tuberculosis-infected macrophages undergo metabolic reprogramming where key mitochondrial pathways are modulated, but the mechanisms driving this metabolic shift is unknown. Our study demonstrates that M. tuberculosis downregulates Sirtuin 3 (SIRT3), an important regulator of mitochondrial metabolism, leading to SIRT3-dependent transcriptional downregulation of mitochondrial metabolic proteins, which is followed by oxidative stress and macrophage necrosis. This study identifies SIRT3 modulation as a key event in M. tuberculosis-induced metabolic reprograming in macrophages that defend against tuberculosis.

scholarly journals Antioxidants Threaten Multikinase Inhibitor Efficacy against Liver Cancer by Blocking Mitochondrial Reactive Oxygen Species

Antioxidants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1336
Author(s):  
Blanca Cucarull ◽  
Anna Tutusaus ◽  
Tania Hernáez-Alsina ◽  
Pablo García de Frutos ◽  
María Reig ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Liver Cancer ◽  
Cell Lines ◽  
Reactive Oxygen ◽  
Chemotherapeutic Agents ◽  
Glutathione Depletion ◽  
Ros Production ◽  
Oxygen Species ◽  
Tumor Spheroids

Sorafenib and regorafenib, multikinase inhibitors (MKIs) used as standard chemotherapeutic agents for hepatocellular carcinoma (HCC), generate reactive oxygen species (ROS) during cancer treatment. Antioxidant supplements are becoming popular additions to our diet, particularly glutathione derivatives and mitochondrial-directed compounds. To address their possible interference during HCC chemotherapy, we analyzed the effect of common antioxidants using hepatoma cell lines and tumor spheroids. In liver cancer cell lines, sorafenib and regorafenib induced mitochondrial ROS production and potent cell death after glutathione depletion. In contrast, cabozantinib only exhibited oxidative cell death in specific HCC cell lines. After sorafenib and regorafenib administration, antioxidants such as glutathione methyl ester and the superoxide scavenger MnTBAP decreased cell death and ROS production, precluding the MKI activity against hepatoma cells. Interestingly, sorafenib-induced mitochondrial damage caused PINK/Parkin-dependent mitophagy stimulation, altered by increased ROS production. Finally, in sorafenib-treated tumor spheroids, while ROS induction reduced tumor growth, antioxidant treatments favored tumor development. In conclusion, the anti-tumor activity of specific MKIs, such as regorafenib and sorafenib, is altered by the cellular redox status, suggesting that uncontrolled antioxidant intake during HCC treatment should be avoided or only endorsed to diminish chemotherapy-induced side effects, always under medical scrutiny.

Reoxygenation after hypoxia and glucose depletion causes reactive oxygen species production by mitochondria in HUVEC

2004 ◽  
Vol 287 (5) ◽  
pp. R1037-R1043 ◽  
Author(s):  
S. Therade-Matharan ◽  
E. Laemmel ◽  
J. Duranteau ◽  
E. Vicaut
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Respiratory Chain ◽  
Reactive Oxygen ◽  
Chain Complex ◽  
Ros Production ◽  
Oxygen Species ◽  
Respiratory Chain Complex ◽  
Type Iii ◽  
Glucose Depletion

In hemorrhagic shock, local hypoxia is present and followed by reoxygenation during the therapeutic process. In endothelium, reactive oxygen species (ROS) have been identified as a cause of inflammatory reactions and tissular lesions in ischemic territory during reoxygenation. This study was designed to identify the enzymatic mechanisms of ROS formation during reoxygenation after hypoxia. Because severe shock, in vivo, can affect both O2 and nutriments, we combined hypoxia at a level close to that found in terminal vessels during shock, with glucose depletion, which induces a relevant additional stress. Human umbilical vein endothelial cells (HUVEC) underwent 2 h of hypoxia (Po2 ∼20 mmHg) without glucose and 1 h of reoxygenation (Po2 ∼120 mmHg) with glucose. ROS production was measured by the fluorescent marker 2′,7′-dichlorodihydrofluorescein diacetate, and cell death by propidium iodide. After 1 h of reoxygenation, fluorescence had risen by 143 ± 17%. Cell death was equal to 8.6 ± 2.4%. Antimycin A and stigmatellin, which inhibits the type III mitochondrial respiratory chain complex, reduced ROS production to values of 61 ± 10 and 59 ± 7%, respectively, but inhibitors of other chain complexes did not affect it. In addition, the increase in fluorescence was not affected by inhibition of NADPH oxidase, xanthine oxidase, NOS, cyclooxygenase, cytochrome P-450 monooxygenase, or monoamine oxidase. We did not observe any increase in cell death. These results show that, in HUVEC, mitochondria are responsible for ROS production after hypoxia and reoxygenation and suggest that a ROS release site is activated in the cytochrome b of the type III respiratory chain complex.

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