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Kazmirchuk TDD, Burnside DJ, Wang J, Jagadeesan SK, Al-Gafari M, Silva E, Potter T, Bradbury-Jost C, Ramessur NB, Ellis B, Takallou S, Hajikarimlou M, Moteshareie H, Said KB, Samanfar B, Fletcher E, Golshani A. Cymoxanil disrupts RNA synthesis through inhibiting the activity of dihydrofolate reductase. Sci Rep 2024; 14:11695. [PMID: 38778133 PMCID: PMC11111663 DOI: 10.1038/s41598-024-62563-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Accepted: 05/18/2024] [Indexed: 05/25/2024] Open
Abstract
The agricultural fungicide cymoxanil (CMX) is commonly used in the treatment of plant pathogens, such as Phytophthora infestans. Although the use of CMX is widespread throughout the agricultural industry and internationally, the exact mechanism of action behind this fungicide remains unclear. Therefore, we sought to elucidate the biocidal mechanism underlying CMX. This was accomplished by first performing a large-scale chemical-genomic screen comprising the 4000 haploid non-essential gene deletion array of the yeast Saccharomyces cerevisiae. We found that gene families related to de novo purine biosynthesis and ribonucleoside synthesis were enriched in the presence of CMX. These results were confirmed through additional spot-test and colony counting assays. We next examined whether CMX affects RNA biosynthesis. Using qRT-PCR and expression assays, we found that CMX appears to target RNA biosynthesis possibly through the yeast dihydrofolate reductase (DHFR) enzyme Dfr1. To determine whether DHFR is a target of CMX, we performed an in-silico molecular docking assay between CMX and yeast, human, and P. infestans DHFR. The results suggest that CMX directly interacts with the active site of all tested forms of DHFR using conserved residues. Using an in vitro DHFR activity assay we observed that CMX inhibits DHFR activity in a dose-dependent relationship.
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Affiliation(s)
| | - Daniel J Burnside
- Department of Biology and the Ottawa Institute of Systems Biology (OISB), Carleton University, Ottawa, K1S 5B6, Canada
| | - Jiashu Wang
- Department of Biology and the Ottawa Institute of Systems Biology (OISB), Carleton University, Ottawa, K1S 5B6, Canada
| | - Sasi Kumar Jagadeesan
- Department of Biology and the Ottawa Institute of Systems Biology (OISB), Carleton University, Ottawa, K1S 5B6, Canada
| | - Mustafa Al-Gafari
- Department of Biology and the Ottawa Institute of Systems Biology (OISB), Carleton University, Ottawa, K1S 5B6, Canada
| | - Eshan Silva
- Department of Biology and the Ottawa Institute of Systems Biology (OISB), Carleton University, Ottawa, K1S 5B6, Canada
| | - Taylor Potter
- Department of Biology and the Ottawa Institute of Systems Biology (OISB), Carleton University, Ottawa, K1S 5B6, Canada
| | - Calvin Bradbury-Jost
- Department of Biology and the Ottawa Institute of Systems Biology (OISB), Carleton University, Ottawa, K1S 5B6, Canada
| | - Nishka Beersing Ramessur
- Department of Biology and the Ottawa Institute of Systems Biology (OISB), Carleton University, Ottawa, K1S 5B6, Canada
| | - Brittany Ellis
- Department of Biology and the Ottawa Institute of Systems Biology (OISB), Carleton University, Ottawa, K1S 5B6, Canada
| | - Sarah Takallou
- Department of Biology and the Ottawa Institute of Systems Biology (OISB), Carleton University, Ottawa, K1S 5B6, Canada
| | - Maryam Hajikarimlou
- Department of Biology and the Ottawa Institute of Systems Biology (OISB), Carleton University, Ottawa, K1S 5B6, Canada
| | - Houman Moteshareie
- Department of Biology and the Ottawa Institute of Systems Biology (OISB), Carleton University, Ottawa, K1S 5B6, Canada
| | - Kamaleldin B Said
- Department of Pathology and Microbiology, University of Hail, 55476, Hail, Saudi Arabia
| | - Bahram Samanfar
- Department of Biology and the Ottawa Institute of Systems Biology (OISB), Carleton University, Ottawa, K1S 5B6, Canada
- Agriculture and Agri-Food Canada, Ottawa, K1A 0C6, Canada
| | - Eugene Fletcher
- Department of Biology and the Ottawa Institute of Systems Biology (OISB), Carleton University, Ottawa, K1S 5B6, Canada
| | - Ashkan Golshani
- Department of Biology and the Ottawa Institute of Systems Biology (OISB), Carleton University, Ottawa, K1S 5B6, Canada.
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Argüelles JC, Sánchez-Fresneda R, Argüelles A, Solano F. Natural Substances as Valuable Alternative for Improving Conventional Antifungal Chemotherapy: Lights and Shadows. J Fungi (Basel) 2024; 10:334. [PMID: 38786689 PMCID: PMC11122340 DOI: 10.3390/jof10050334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 05/01/2024] [Accepted: 05/02/2024] [Indexed: 05/25/2024] Open
Abstract
Fungi are eukaryotic organisms with relatively few pathogenic members dangerous for humans, usually acting as opportunistic infections. In the last decades, several life-threatening fungal infections have risen mostly associated with the worldwide extension of chronic diseases and immunosuppression. The available antifungal therapies cannot combat this challenge because the arsenal of compounds is scarce and displays low selective action, significant adverse effects, and increasing resistance. A growing isolation of outbreaks triggered by fungal species formerly considered innocuous is being recorded. From ancient times, natural substances harvested from plants have been applied to folk medicine and some of them recently emerged as promising antifungals. The most used are briefly revised herein. Combinations of chemotherapeutic drugs with natural products to obtain more efficient and gentle treatments are also revised. Nevertheless, considerable research work is still necessary before their clinical use can be generally accepted. Many natural products have a highly complex chemical composition, with the active principles still partially unknown. Here, we survey the field underlying lights and shadows of both groups. More studies involving clinical strains are necessary, but we illustrate this matter by discussing the potential clinical applications of combined carnosic acid plus propolis formulations.
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Affiliation(s)
- Juan Carlos Argüelles
- Área de Microbiología, Facultad Biología, University Murcia, Campus Espinardo, 30100 Murcia, Spain; (J.C.A.); (R.S.-F.); (A.A.)
| | - Ruth Sánchez-Fresneda
- Área de Microbiología, Facultad Biología, University Murcia, Campus Espinardo, 30100 Murcia, Spain; (J.C.A.); (R.S.-F.); (A.A.)
| | - Alejandra Argüelles
- Área de Microbiología, Facultad Biología, University Murcia, Campus Espinardo, 30100 Murcia, Spain; (J.C.A.); (R.S.-F.); (A.A.)
| | - Francisco Solano
- Departamento Bioquímica, Biología Molecular B & Inmunología, Facultad Medicina, University Murcia, Campus El Palmar, 30112 Murcia, Spain
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Parsons JL, Cameron SI, Harris CS, Smith ML. Echinacea biotechnology: advances, commercialization and future considerations. PHARMACEUTICAL BIOLOGY 2018; 56:485-494. [PMID: 30303034 PMCID: PMC6179083 DOI: 10.1080/13880209.2018.1501583] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 06/20/2018] [Accepted: 07/14/2018] [Indexed: 05/06/2023]
Abstract
CONTEXT Plants of the genus Echinacea (Asteraceae) are among the most popular herbal supplements on the market today. Recent studies indicate there are potential new applications and emerging markets for this natural health product (NHP). OBJECTIVE This review aims to synthesize recent developments in Echinacea biotechnology and to identify promising applications for these advances in the industry. METHODS A comprehensive survey of peer-reviewed publications was carried out, focusing on Echinacea biotechnology and impacts on phytochemistry. This article primarily covers research findings since 2007 and builds on earlier reviews on the biotechnology of Echinacea. RESULTS Bioreactors, genetic engineering and controlled biotic or abiotic elicitation have the potential to significantly improve the yield, consistency and overall quality of Echinacea products. Using these technologies, a variety of new applications for Echinacea can be realized, such as the use of seed oil and antimicrobial and immune boosting feed additives for livestock. CONCLUSIONS New applications can take advantage of the well-established popularity of Echinacea as a NHP. Echinacea presents a myriad of potential health benefits, including anti-inflammatory, anxiolytic and antibiotic activities that have yet to be fully translated into new applications. The distinct chemistry and bioactivity of different Echinacea species and organs, moreover, can lead to interesting and diverse commercial opportunities.
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Affiliation(s)
- Jessica L. Parsons
- Ottawa-Carleton Institute of Biology, Ottawa, ON, Canada
- Department of Biology, Carleton University, Ottawa, ON, Canada
| | - Stewart I. Cameron
- Wood Science and Technology Centre, Hugh John Flemming Forestry Centre, Fredericton, NB, Canada
| | - Cory S. Harris
- Ottawa-Carleton Institute of Biology, Ottawa, ON, Canada
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - Myron L. Smith
- Ottawa-Carleton Institute of Biology, Ottawa, ON, Canada
- Department of Biology, Carleton University, Ottawa, ON, Canada
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4
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Galván Márquez I, Ghiyasvand M, Massarsky A, Babu M, Samanfar B, Omidi K, Moon TW, Smith ML, Golshani A. Zinc oxide and silver nanoparticles toxicity in the baker's yeast, Saccharomyces cerevisiae. PLoS One 2018; 13:e0193111. [PMID: 29554091 PMCID: PMC5858749 DOI: 10.1371/journal.pone.0193111] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 02/05/2018] [Indexed: 12/18/2022] Open
Abstract
Engineered nanomaterials (ENMs) are increasingly incorporated into a variety of commercial applications and consumer products; however, ENMs may possess cytotoxic properties due to their small size. This study assessed the effects of two commonly used ENMs, zinc oxide nanoparticles (ZnONPs) and silver nanoparticles (AgNPs), in the model eukaryote Saccharomyces cerevisiae. A collection of ≈4600 S. cerevisiae deletion mutant strains was used to deduce the genes, whose absence makes S. cerevisiae more prone to the cytotoxic effects of ZnONPs or AgNPs. We demonstrate that S. cerevisiae strains that lack genes involved in transmembrane and membrane transport, cellular ion homeostasis, and cell wall organization or biogenesis exhibited the highest sensitivity to ZnONPs. In contrast, strains that lack genes involved in transcription and RNA processing, cellular respiration, and endocytosis and vesicular transport exhibited the highest sensitivity to AgNPs. Secondary assays confirmed that ZnONPs affected cell wall function and integrity, whereas AgNPs exposure decreased transcription, reduced endocytosis, and led to a dysfunctional electron transport system. This study supports the use of S. cerevisiae Gene Deletion Array as an effective high-throughput technique to determine cellular targets of ENM toxicity.
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Affiliation(s)
- Imelda Galván Márquez
- Department of Biology and Ottawa Institute of Systems Biology, Carleton University, Ottawa, Ontario, Canada
| | - Mergan Ghiyasvand
- Department of Biology and Ottawa Institute of Systems Biology, Carleton University, Ottawa, Ontario, Canada
| | - Andrey Massarsky
- Department of Biology, Centre for Advanced Research in Environmental Genomics and the Collaborative Program in Chemical and Environmental Toxicology, University of Ottawa, Ottawa, Ontario, Canada
| | - Mohan Babu
- Department of Biochemistry, University of Regina, Regina, Saskatchewan, Canada
| | - Bahram Samanfar
- Department of Biology and Ottawa Institute of Systems Biology, Carleton University, Ottawa, Ontario, Canada
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre (ORDC), Ottawa, Ontario, Canada
| | - Katayoun Omidi
- Department of Biology and Ottawa Institute of Systems Biology, Carleton University, Ottawa, Ontario, Canada
| | - Thomas W. Moon
- Department of Biology, Centre for Advanced Research in Environmental Genomics and the Collaborative Program in Chemical and Environmental Toxicology, University of Ottawa, Ottawa, Ontario, Canada
| | - Myron L. Smith
- Department of Biology and Ottawa Institute of Systems Biology, Carleton University, Ottawa, Ontario, Canada
- * E-mail: (MLS); (AG)
| | - Ashkan Golshani
- Department of Biology and Ottawa Institute of Systems Biology, Carleton University, Ottawa, Ontario, Canada
- * E-mail: (MLS); (AG)
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The modulatory influence of some Echinacea-based remedies on antibody production and cellular immunity in mice. Cent Eur J Immunol 2016; 41:12-8. [PMID: 27095917 PMCID: PMC4829818 DOI: 10.5114/ceji.2016.58813] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 12/29/2015] [Indexed: 11/17/2022] Open
Abstract
Echinacea purpurea-containing remedies are herbal medicines used in respiratory tract infections and several inflammatory conditions as enhancers of non-specific and modulators of specific cellular immunity. They also exert anti-inflammatory, anti-viral, and anti-microbial activity. The aim of the present study was to compare the in vivo influence of orally administered three Echinacea purpurea-based remedies (IMMUNAL drops, ECHINACEA FORTE drops, IMMUNAL FORTE tablets) on some parameters of cellular and humoral immunity in mice.
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6
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Kim HR, Oh SK, Lim W, Lee HK, Moon BI, Seoh JY. Immune Enhancing Effects of Echinacea purpurea Root Extract by Reducing Regulatory T Cell Number and Function. Nat Prod Commun 2014. [DOI: 10.1177/1934578x1400900422] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Echinacea purpurea preparations (EPs) have been traditionally used for the treatment of various infections and also for wound healing. Accumulating evidence suggests their immunostimulatory effects. Regulatory T cells (Tregs) are known to play a key role in immune regulation in vivo. However, there have been no reports so far on the effects of EP on the frequency or function of Tregs in vivo. Therefore, in the present study, we investigated the quantitative and functional changes in Tregs by in vivo administration with EP. The frequencies of CD4+FoxP3+ and CD4+CD25+ Tregs in the spleens of BALB/c mice administered with EP for 3 weeks were investigated by flow cytometry. The suppressive function of CD4+CD25+ Tregs in association with the proliferative activity of CD4+CD25- effector T cells (Teffs) and the feeder function of CD4- antigen-presenting cells (APCs) were analyzed by carboxyfluorescein succinimidyl ester-dilution assay. The results showed a lowered frequency of CD4+FoxP3+ and CD4+CD25+ Tregs and attenuated suppressive function of CD4+CD25+ Tregs, while the feeder function of APCs was enhanced in the EP-administered mice. On the other hand, the proliferative activity of Teffs was not significantly different in the EP-administered mice. The results suggest that decreased number and function of Tregs, in association with the enhanced feeder function of APCs, may contribute to the enhancement of immune function by EP.
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Affiliation(s)
- Hyung-Ran Kim
- Department of Microbiology, Graduate School of Medicine, Seoul 158-710, Korea
| | - Sei-Kwan Oh
- Molecular Medicine, Graduate School of Medicine, Seoul 158-710, Korea
| | - Woosung Lim
- Surgery, Ewha Womans University Graduate School of Medicine, Seoul 158-710, Korea
| | - Hyeon Kook Lee
- Surgery, Ewha Womans University Graduate School of Medicine, Seoul 158-710, Korea
| | - Byung-In Moon
- Surgery, Ewha Womans University Graduate School of Medicine, Seoul 158-710, Korea
| | - Ju-Young Seoh
- Department of Microbiology, Graduate School of Medicine, Seoul 158-710, Korea
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Cruz I, Cheetham JJ, Arnason JT, Yack JE, Smith ML. Alkamides from Echinacea disrupt the fungal cell wall-membrane complex. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2014; 21:435-442. [PMID: 24252333 DOI: 10.1016/j.phymed.2013.10.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 08/15/2013] [Accepted: 10/17/2013] [Indexed: 06/02/2023]
Abstract
We tested the hypothesis that alkamides from Echinacea exert antifungal activity by disrupting the fungal cell wall/membrane complex. Saccharomyces cerevisiae cells were treated separately with each of seven synthetic alkamides found in Echinacea extracts. The resulting cell wall damage and cell viability were assessed by fluorescence microscopy after mild sonication. Membrane disrupting properties of test compounds were studied using liposomes encapsulating carboxyfluorescein. Negative controls included hygromycin and nourseothricin (aminoglycosides that inhibit protein synthesis), and the positive control used was caspofungin (an echinocandin that disrupts fungal cell walls). The results show that yeast cells exposed to sub-inhibitory concentrations of each of the seven alkamides and Echinacea extract exhibit increased frequencies of cell wall damage and death that were comparable to caspofungin and significantly greater than negative controls. Consistent with effects of cell wall damaging agents, the growth inhibition by three representative alkamides tested and caspofungin, but not hygromycin B, were partially reversed in sorbitol protection assays. Membrane disruption assays showed that the Echinacea extract and alkamides have pronounced membrane disruption activity, in contrast to caspofungin and other controls that all had little effect on membrane stability. A Quantitative Structure-Activity Relationship (QSAR) analysis was performed to study the effect of structural substituents on the antifungal activity of the alkamides. Among the set studied, diynoic alkamides showed the greatest antifungal and cell wall disruption activities while an opposite trend was observed in the membrane disruption assay where the dienoic group was more effective. We propose that alkamides found in Echinacea act synergistically to disrupt the fungal cell wall/membrane complex, an excellent target for specific inhibition of fungal pathogens. Structure-function relationships provide opportunities for synthesis of alkamide analogs with improved antifungal activities.
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Affiliation(s)
- I Cruz
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
| | - J J Cheetham
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
| | - J T Arnason
- Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, Ontario K1N 6N5, Canada
| | - J E Yack
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
| | - M L Smith
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada.
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8
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Darvishi E, Omidi M, Bushehri AAS, Golshani A, Smith ML. The antifungal eugenol perturbs dual aromatic and branched-chain amino acid permeases in the cytoplasmic membrane of yeast. PLoS One 2013; 8:e76028. [PMID: 24204588 PMCID: PMC3799837 DOI: 10.1371/journal.pone.0076028] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 08/23/2013] [Indexed: 12/13/2022] Open
Abstract
Eugenol is an aromatic component of clove oil that has therapeutic potential as an antifungal drug, although its mode of action and precise cellular target(s) remain ambiguous. To address this knowledge gap, a chemical-genetic profile analysis of eugenol was done using ∼4700 haploid Saccharomyces cerevisiae gene deletion mutants to reveal 21 deletion mutants with the greatest degree of susceptibility. Cellular roles of deleted genes in the most susceptible mutants indicate that the main targets for eugenol include pathways involved in biosynthesis and transport of aromatic and branched-chain amino acids. Follow-up analyses showed inhibitory effects of eugenol on amino acid permeases in the yeast cytoplasmic membrane. Furthermore, phenotypic suppression analysis revealed that eugenol interferes with two permeases, Tat1p and Gap1p, which are both involved in dual transport of aromatic and branched-chain amino acids through the yeast cytoplasmic membrane. Perturbation of cytoplasmic permeases represents a novel antifungal target and may explain previous observations that exposure to eugenol results in leakage of cell contents. Eugenol exposure may also contribute to amino acid starvation and thus holds promise as an anticancer therapeutic drug. Finally, this study provides further evidence of the usefulness of the yeast Gene Deletion Array approach in uncovering the mode of action of natural health products.
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Affiliation(s)
- Emad Darvishi
- Department of Agronomy and Plant Breeding, University of Tehran, Karaj, Iran
- Biology Department, Carleton University, Ottawa, Ontario, Canada
| | - Mansoor Omidi
- Department of Agronomy and Plant Breeding, University of Tehran, Karaj, Iran
| | | | - Ashkan Golshani
- Biology Department, Carleton University, Ottawa, Ontario, Canada
- * E-mail: (AG); (MLS)
| | - Myron L. Smith
- Biology Department, Carleton University, Ottawa, Ontario, Canada
- * E-mail: (AG); (MLS)
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9
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Bento T, Torres L, Fialho M, Bononi V. Growth inhibition and antioxidative response of wood decay fungi exposed to plant extracts of Casearia
species. Lett Appl Microbiol 2013; 58:79-86. [DOI: 10.1111/lam.12159] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 08/28/2013] [Accepted: 09/09/2013] [Indexed: 11/26/2022]
Affiliation(s)
- T.S. Bento
- Instituto de Botânica de São Paulo; Núcleo de Pesquisa em Micologia; São Paulo Brazil
| | - L.M.B. Torres
- Instituto de Botânica de São Paulo; Núcleo de Pesquisa em Fisiologia e Bioquímica de Plantas; São Paulo Brazil
| | - M.B. Fialho
- Instituto de Botânica de São Paulo; Núcleo de Pesquisa em Fisiologia e Bioquímica de Plantas; São Paulo Brazil
| | - V.L.R. Bononi
- Instituto de Botânica de São Paulo; Núcleo de Pesquisa em Micologia; São Paulo Brazil
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10
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Cell wall perturbation sensitizes fungi to the antimalarial drug chloroquine. Antimicrob Agents Chemother 2013; 57:3889-96. [PMID: 23733464 DOI: 10.1128/aac.00478-13] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chloroquine (CQ) has been a mainstay of antimalarial drug treatment for several decades. Additional therapeutic actions of CQ have been described, including some reports of fungal inhibition. Here we investigated the action of CQ in fungi, including the yeast model Saccharomyces cerevisiae. A genomewide yeast deletion strain collection was screened against CQ, revealing that bck1Δ and slt2Δ mutants of the cell wall integrity pathway are CQ hypersensitive. This phenotype was rescued with sorbitol, consistent with cell wall involvement. The cell wall-targeting agent caffeine caused hypersensitivity to CQ, as did cell wall perturbation by sonication. The phenotypes were not caused by CQ-induced changes to cell wall components. Instead, CQ accumulated to higher levels in cells with perturbed cell walls: CQ uptake was 2- to 3-fold greater in bck1Δ and slt2Δ mutants than in wild-type yeast. CQ toxicity was synergistic with that of the major cell wall-targeting antifungal drug, caspofungin. The MIC of caspofungin against the yeast pathogen Candida albicans was decreased 2-fold by 250 μM CQ and up to 8-fold at higher CQ concentrations. Similar effects were seen in Candida glabrata and Aspergillus fumigatus. The results show that the cell wall is critical for CQ resistance in fungi and suggest that combination treatments with cell wall-targeting drugs could have potential for antifungal treatment.
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Galván Márquez I, Akuaku J, Cruz I, Cheetham J, Golshani A, Smith ML. Disruption of protein synthesis as antifungal mode of action by chitosan. Int J Food Microbiol 2013; 164:108-12. [DOI: 10.1016/j.ijfoodmicro.2013.03.025] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 03/17/2013] [Accepted: 03/29/2013] [Indexed: 10/27/2022]
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Axl2 integrates polarity establishment, maintenance, and environmental stress response in the filamentous fungus Ashbya gossypii. EUKARYOTIC CELL 2011; 10:1679-93. [PMID: 21984708 DOI: 10.1128/ec.05183-11] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
In budding yeast, new sites of polarity are chosen with each cell cycle and polarization is transient. In filamentous fungi, sites of polarity persist for extended periods of growth and new polarity sites can be established while existing sites are maintained. How the polarity establishment machinery functions in these distinct growth forms found in fungi is still not well understood. We have examined the function of Axl2, a transmembrane bud site selection protein discovered in Saccharomyces cerevisiae, in the filamentous fungus Ashbya gossypii. A. gossypii does not divide by budding and instead exhibits persistent highly polarized growth, and multiple axes of polarity coexist in one cell. A. gossypii axl2Δ (Agaxl2Δ) cells have wavy hyphae, bulbous tips, and a high frequency of branch initiations that fail to elongate, indicative of a polarity maintenance defect. Mutant colonies also have significantly lower radial growth and hyphal tip elongation speeds than wild-type colonies, and Agaxl2Δ hyphae have depolarized actin patches. Consistent with a function in polarity, AgAxl2 localizes to hyphal tips, branches, and septin rings. Unlike S. cerevisiae Axl2, AgAxl2 contains a Mid2 homology domain and may function to sense or respond to environmental stress. In support of this idea, hyphae lacking AgAxl2 also display hypersensitivity to heat, osmotic, and cell wall stresses. Axl2 serves to integrate polarity establishment, polarity maintenance, and environmental stress response for optimal polarized growth in A. gossypii.
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