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Kim B, Nguyen MV, Park J, Kim YS, Han JW, Lee JY, Jeon J, Son H, Choi GJ, Kim H. Edeine B 1 produced by Brevibacillus brevis reduces the virulence of a plant pathogenic fungus by inhibiting mitochondrial respiration. mBio 2024:e0135124. [PMID: 38860787 DOI: 10.1128/mbio.01351-24] [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: 05/03/2024] [Accepted: 05/06/2024] [Indexed: 06/12/2024] Open
Abstract
Plant pathogenic fungi cause serious diseases, which result in the loss of crop yields and reduce the quality of crops worldwide. To counteract the escalating risks of chemical fungicides, interest in biological control agents to manage plant diseases has significantly increased. In this study, we comprehensively screened microbial culture filtrates using a yeast screening system to find microbes exhibiting respiratory inhibition activity. Consequently, we found a soil-borne microbe Brevibacillus brevis HK544 strain exhibiting a respiration inhibitory activity and identified edeine B1 (EB1) from the culture filtrate of HK544 as the active compound of the respiration inhibition activity. Furthermore, against a plant pathogenic fungus Fusarium graminearum, our results showed that EB1 has effects on multiple aspects of respiration with the downregulation of most of the mitochondrial-related genes based on transcriptome analysis, differential EB1-sensitivity from targeted mutagenesis, and the synergistic effects of EB1 with electron transport chain complex inhibitors. With the promising plant disease control efficacy of B. brevis HK544 producing EB1, our results suggest that B. brevis HK544 has potential as a biocontrol agent for Fusarium head blight.IMPORTANCEAs a necrotrophic fungus, Fusarium graminearum is a highly destructive pathogen causing severe diseases in cereal crops and mycotoxin contamination in grains. Although chemical control is considered the primary approach to control plant disease caused by F. graminearum, fungicide-resistant strains have been detected in the field after long-term continuous application of fungicides. Moreover, applying chemical fungicides that trigger mycotoxin biosynthesis is a great concern for many researchers. Biocontrol of Fusarium head blight (FHB) by biological control agents (BCAs) represents an alternative approach and could be used as part of the integrated management of FHB and mycotoxin production. The most extensive studies on bacterial BCAs-fungal communications in agroecosystems have focused on antibiosis. Although many BCAs in agricultural ecology have already been used for fungal disease control, the molecular mechanisms of antibiotics produced by BCAs remain to be elucidated. Here, we found a potential BCA (Brevibacillus brevis HK544) with a strong antifungal activity based on the respiration inhibition activity with its active compound edeine B1 (EB1). Furthermore, our results showed that EB1 secreted by HK544 suppresses the expression of the mitochondria-related genes of F. graminearum, subsequently suppressing fungal development and the virulence of F. graminearum. In addition, EB1 exhibited a synergism with complex I inhibitors such as rotenone and fenazaquin. Our work extends our understanding of how B. brevis HK544 exhibits antifungal activity and suggests that the B. brevis HK544 strain could be a valuable source for developing new crop protectants to control F. graminearum.
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Affiliation(s)
- Bomin Kim
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon, South Korea
- Department of Medicinal Chemistry and Pharmacology, University of Science and Technology, Daejeon, South Korea
| | - Minh Van Nguyen
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon, South Korea
- Department of Medicinal Chemistry and Pharmacology, University of Science and Technology, Daejeon, South Korea
| | - Jiyeun Park
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Yeong Seok Kim
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon, South Korea
- Department of Medicinal Chemistry and Pharmacology, University of Science and Technology, Daejeon, South Korea
| | - Jae Woo Han
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon, South Korea
| | - Joo-Youn Lee
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology, Daejeon, South Korea
| | - Junhyun Jeon
- Department of Biotechnology, Yeungnam University, Gyeongsan, South Korea
| | - Hokyoung Son
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Gyung Ja Choi
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon, South Korea
- Department of Medicinal Chemistry and Pharmacology, University of Science and Technology, Daejeon, South Korea
| | - Hun Kim
- Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon, South Korea
- Department of Medicinal Chemistry and Pharmacology, University of Science and Technology, Daejeon, South Korea
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2
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Hang S, Lu H, Jiang Y. Marine-Derived Metabolites Act as Promising Antifungal Agents. Mar Drugs 2024; 22:180. [PMID: 38667797 PMCID: PMC11051449 DOI: 10.3390/md22040180] [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: 03/20/2024] [Revised: 04/11/2024] [Accepted: 04/13/2024] [Indexed: 04/28/2024] Open
Abstract
The incidence of invasive fungal diseases (IFDs) is on the rise globally, particularly among immunocompromised patients, leading to significant morbidity and mortality. Current clinical antifungal agents, such as polyenes, azoles, and echinocandins, face increasing resistance from pathogenic fungi. Therefore, there is a pressing need for the development of novel antifungal drugs. Marine-derived secondary metabolites represent valuable resources that are characterized by varied chemical structures and pharmacological activities. While numerous compounds exhibiting promising antifungal activity have been identified, a comprehensive review elucidating their specific underlying mechanisms remains lacking. In this review, we have compiled a summary of antifungal compounds derived from marine organisms, highlighting their diverse mechanisms of action targeting various fungal cellular components, including the cell wall, cell membrane, mitochondria, chromosomes, drug efflux pumps, and several biological processes, including vesicular trafficking and the growth of hyphae and biofilms. This review is helpful for the subsequent development of antifungal drugs due to its summary of the antifungal mechanisms of secondary metabolites from marine organisms.
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Affiliation(s)
| | - Hui Lu
- Department of Pharmacy, Shanghai Tenth People’s Hospital, School of Medicine, Tongji University, 200092 Shanghai, China
| | - Yuanying Jiang
- Department of Pharmacy, Shanghai Tenth People’s Hospital, School of Medicine, Tongji University, 200092 Shanghai, China
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3
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Edrich ESM, Duvenage L, Gourlay CW. Alternative Oxidase - Aid or obstacle to combat the rise of fungal pathogens? BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2024; 1865:149031. [PMID: 38195037 DOI: 10.1016/j.bbabio.2024.149031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 11/16/2023] [Accepted: 01/03/2024] [Indexed: 01/11/2024]
Abstract
Fungal pathogens present a growing threat to both humans and global health security alike. Increasing evidence of antifungal resistance in fungal populations that infect both humans and plant species has increased reliance on combination therapies and shown the need for new antifungal therapeutic targets to be investigated. Here, we review the roles of mitochondria and fungal respiration in pathogenesis and discuss the role of the Alternative Oxidase enzyme (Aox) in both human fungal pathogens and phytopathogens. Increasing evidence exists for Aox within mechanisms that underpin fungal virulence. Aox also plays important roles in adaptability that may prove useful within dual targeted fungal-specific therapeutic approaches. As improved fungal specific mitochondrial and Aox inhibitors are under development we may see this as an emerging target for future approaches to tackling the growing challenge of fungal infection.
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Affiliation(s)
| | - Lucian Duvenage
- CMM AFRICA Medical Mycology Research Unit, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Campbell W Gourlay
- Kent Fungal Group, School of Biosciences, University of Kent, Kent CT2 9HY, UK.
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4
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Li J, Yang S, Wu Y, Wang R, Liu Y, Liu J, Ye Z, Tang R, Whiteway M, Lv Q, Yan L. Alternative Oxidase: From Molecule and Function to Future Inhibitors. ACS OMEGA 2024; 9:12478-12499. [PMID: 38524433 PMCID: PMC10955580 DOI: 10.1021/acsomega.3c09339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 01/31/2024] [Accepted: 02/07/2024] [Indexed: 03/26/2024]
Abstract
In the respiratory chain of the majority of aerobic organisms, the enzyme alternative oxidase (AOX) functions as the terminal oxidase and has important roles in maintaining metabolic and signaling homeostasis in mitochondria. AOX endows the respiratory system with flexibility in the coupling among the carbon metabolism pathway, electron transport chain (ETC) activity, and ATP turnover. AOX allows electrons to bypass the main cytochrome pathway to restrict the generation of reactive oxygen species (ROS). The inhibition of AOX leads to oxidative damage and contributes to the loss of adaptability and viability in some pathogenic organisms. Although AOXs have recently been identified in several organisms, crystal structures and major functions still need to be explored. Recent work on the trypanosome alternative oxidase has provided a crystal structure of an AOX protein, which contributes to the structure-activity relationship of the inhibitors of AOX. Here, we review the current knowledge on the development, structure, and properties of AOXs, as well as their roles and mechanisms in plants, animals, algae, protists, fungi, and bacteria, with a special emphasis on the development of AOX inhibitors, which will improve the understanding of respiratory regulation in many organisms and provide references for subsequent studies of AOX-targeted inhibitors.
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Affiliation(s)
- Jiye Li
- School
of Pharmacy, Naval Medical University, Shanghai 200433, China
- Institute
of Medicinal Biotechnology, Chinese Academy
of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Shiyun Yang
- School
of Pharmacy, Naval Medical University, Shanghai 200433, China
| | - Yujie Wu
- School
of Pharmacy, Naval Medical University, Shanghai 200433, China
| | - Ruina Wang
- School
of Pharmacy, Naval Medical University, Shanghai 200433, China
| | - Yu Liu
- School
of Pharmacy, Naval Medical University, Shanghai 200433, China
| | - Jiacun Liu
- School
of Pharmacy, Naval Medical University, Shanghai 200433, China
| | - Zi Ye
- School
of Pharmacy, Naval Medical University, Shanghai 200433, China
| | - Renjie Tang
- Beijing
South Medical District of Chinese PLA General Hospital, Beijing 100072, China
| | - Malcolm Whiteway
- Department
of Biology, Concordia University, Montreal, H4B 1R6 Quebec, Canada
| | - Quanzhen Lv
- School
of Pharmacy, Naval Medical University, Shanghai 200433, China
- Basic
Medicine Innovation Center for Fungal Infectious Diseases, (Naval Medical University), Ministry of Education, Shanghai 200433, China
- Key
Laboratory of Biosafety Defense (Naval Medical University), Ministry
of Education, Shanghai 200433, China
- Shanghai
Key Laboratory of Medical Biodefense, Shanghai 200433, China
| | - Lan Yan
- School
of Pharmacy, Naval Medical University, Shanghai 200433, China
- Basic
Medicine Innovation Center for Fungal Infectious Diseases, (Naval Medical University), Ministry of Education, Shanghai 200433, China
- Key
Laboratory of Biosafety Defense (Naval Medical University), Ministry
of Education, Shanghai 200433, China
- Shanghai
Key Laboratory of Medical Biodefense, Shanghai 200433, China
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5
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Valderrama V, Sánchez P, Delso M, Díaz-Dosque M, Escobar A, Budini M, Catalán M, Vivar R, López-Muñoz R, Jara JA, Molina-Berríos A. Gallic acid triphenylphosphonium derivatives TPP+-C10 and TPP+-C12 inhibit mitochondrial function in Candida albicans exerting antifungal and antibiofilm effects. J Appl Microbiol 2024; 135:lxad316. [PMID: 38148145 DOI: 10.1093/jambio/lxad316] [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: 05/22/2023] [Revised: 11/20/2023] [Accepted: 12/25/2023] [Indexed: 12/28/2023]
Abstract
AIMS To evaluate the antifungal and antibiofilm activity of gallic acid derivatives TPP+-C10 and TPP+-C12 and their effects on mitochondrial function on two Candida albicans reference strains (ATCC 90029 and ATCC 10231). METHODS AND RESULTS First, we determined minimal inhibitory concentration (MIC) using a microdilution assay. Both compounds exerted antifungal effects, and their MICs ranged from 3.9 to 13 µM, with no statistically significant differences between them (P > 0.05, t-test). These concentrations served as references for following assays. Subsequently, we measured oxygen consumption with a Clark electrode. Our observations revealed that both drugs inhibited oxygen consumption in both strains with TPP+-C12 exerting a more pronounced inhibitory effect. We then employed flow cytometry with TMRE as a probe to assess mitochondrial membrane potential. For each strain assayed, the compounds induced a decay in transmembrane potential by 75%-90% compared to the control condition (P < 0.05, ANOVA). Then, we measured ATP levels using a commercial kit. TPP+-C12 showed a 50% decrease of ATP content (P < 0.05 ANOVA), while TPP+-C10 exhibited a less pronounced effect. Finally, we assessed the antibiofilm effect using the MTT reduction assay. Both compounds were effective, but TPP+-C12 displayed a greater potency, requiring a lower concentration to inhibit 50% of biofilms viability (P < 0.05, t-test). CONCLUSIONS Derivatives of gallic acid linked to a TPP+ group exert antifungal and antibiofilm activity through impairment of mitochondrial function in C. albicans.
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Affiliation(s)
- Victoria Valderrama
- Laboratory of Applied Pharmacology for the Development of Anticancer and Antifungal Drugs, Institute for Research in Dental Sciences (ICOD), Faculty of Dentistry, University of Chile, Santiago, 8380544, Chile
| | - Paula Sánchez
- Laboratory of Applied Pharmacology for the Development of Anticancer and Antifungal Drugs, Institute for Research in Dental Sciences (ICOD), Faculty of Dentistry, University of Chile, Santiago, 8380544, Chile
| | - Macarena Delso
- Laboratory of Applied Pharmacology for the Development of Anticancer and Antifungal Drugs, Institute for Research in Dental Sciences (ICOD), Faculty of Dentistry, University of Chile, Santiago, 8380544, Chile
| | - Mario Díaz-Dosque
- Laboratory of Applied Pharmacology for the Development of Anticancer and Antifungal Drugs, Institute for Research in Dental Sciences (ICOD), Faculty of Dentistry, University of Chile, Santiago, 8380544, Chile
- Laboratory of Nanobiomaterials, Institute for Research in Dental Sciences (ICOD), Faculty of Dentistry, University of Chile, Santiago, 8380544, Chile
| | - Alejandro Escobar
- Laboratory of Cellular Biology, Institute for Research in Dental Sciences (ICOD), Faculty of Dentistry, University of Chile, Santiago, 8380544, Chile
| | - Mauricio Budini
- Cellular and Molecular Pathology Laboratory, Institute for Research in Dental Sciences (ICOD), Faculty of Dentistry, University of Chile, Santiago, 8380544, Chile
| | - Mabel Catalán
- Clinical and Molecular Pharmacology Program, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, University of Chile, Santiago, 8380453, Chile
| | - Raúl Vivar
- Clinical and Molecular Pharmacology Program, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, University of Chile, Santiago, 8380453, Chile
| | - Rodrigo López-Muñoz
- Instituto de Farmacología y Morfofisiología, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, 5110566, Chile
| | - José A Jara
- Laboratory of Applied Pharmacology for the Development of Anticancer and Antifungal Drugs, Institute for Research in Dental Sciences (ICOD), Faculty of Dentistry, University of Chile, Santiago, 8380544, Chile
| | - Alfredo Molina-Berríos
- Laboratory of Applied Pharmacology for the Development of Anticancer and Antifungal Drugs, Institute for Research in Dental Sciences (ICOD), Faculty of Dentistry, University of Chile, Santiago, 8380544, Chile
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6
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Silao FGS, Jiang T, Bereczky-Veress B, Kühbacher A, Ryman K, Uwamohoro N, Jenull S, Nogueira F, Ward M, Lion T, Urban CF, Rupp S, Kuchler K, Chen C, Peuckert C, Ljungdahl PO. Proline catabolism is a key factor facilitating Candida albicans pathogenicity. PLoS Pathog 2023; 19:e1011677. [PMID: 37917600 PMCID: PMC10621835 DOI: 10.1371/journal.ppat.1011677] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 09/11/2023] [Indexed: 11/04/2023] Open
Abstract
Candida albicans, the primary etiology of human mycoses, is well-adapted to catabolize proline to obtain energy to initiate morphological switching (yeast to hyphal) and for growth. We report that put1-/- and put2-/- strains, carrying defective Proline UTilization genes, display remarkable proline sensitivity with put2-/- mutants being hypersensitive due to the accumulation of the toxic intermediate pyrroline-5-carboxylate (P5C), which inhibits mitochondrial respiration. The put1-/- and put2-/- mutations attenuate virulence in Drosophila and murine candidemia models and decrease survival in human neutrophils and whole blood. Using intravital 2-photon microscopy and label-free non-linear imaging, we visualized the initial stages of C. albicans cells infecting a kidney in real-time, directly deep in the tissue of a living mouse, and observed morphological switching of wildtype but not of put2-/- cells. Multiple members of the Candida species complex, including C. auris, are capable of using proline as a sole energy source. Our results indicate that a tailored proline metabolic network tuned to the mammalian host environment is a key feature of opportunistic fungal pathogens.
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Affiliation(s)
- Fitz Gerald S. Silao
- Department of Molecular Biosciences, The Wenner-Gren Institute, Science for Life Laboratory, Stockholm University, Solna, Sweden
| | - Tong Jiang
- Shanghai Institute of Immunity and Infection, Chinese Academy of Sciences, Shanghai, China
| | - Biborka Bereczky-Veress
- Intravital Microscopy Facility, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Andreas Kühbacher
- Department of Molecular Biotechnology, Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Stuttgart, Germany
| | - Kicki Ryman
- Department of Molecular Biosciences, The Wenner-Gren Institute, Science for Life Laboratory, Stockholm University, Solna, Sweden
| | - Nathalie Uwamohoro
- Clinical Microbiology and Umeå Centre for Microbial Research (UCMR), Umeå University Umeå, Sweden
| | - Sabrina Jenull
- Medical University of Vienna, Max F. Perutz Laboratories GmbH, Department of Medical Biochemistry, Vienna, Austria
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Filomena Nogueira
- Medical University of Vienna, Max F. Perutz Laboratories GmbH, Department of Medical Biochemistry, Vienna, Austria
- St. Anna Kinderkrebsforschung e.V., Children’s Cancer Research Institute, Vienna, Austria
| | - Meliza Ward
- Department of Molecular Biosciences, The Wenner-Gren Institute, Science for Life Laboratory, Stockholm University, Solna, Sweden
| | - Thomas Lion
- St. Anna Kinderkrebsforschung e.V., Children’s Cancer Research Institute, Vienna, Austria
| | - Constantin F. Urban
- Clinical Microbiology and Umeå Centre for Microbial Research (UCMR), Umeå University Umeå, Sweden
| | - Steffen Rupp
- Department of Molecular Biotechnology, Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Stuttgart, Germany
| | - Karl Kuchler
- Medical University of Vienna, Max F. Perutz Laboratories GmbH, Department of Medical Biochemistry, Vienna, Austria
| | - Changbin Chen
- Shanghai Institute of Immunity and Infection, Chinese Academy of Sciences, Shanghai, China
| | - Christiane Peuckert
- Intravital Microscopy Facility, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Per O. Ljungdahl
- Department of Molecular Biosciences, The Wenner-Gren Institute, Science for Life Laboratory, Stockholm University, Solna, Sweden
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7
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Liu Z, Basso P, Hossain S, Liston SD, Robbins N, Whitesell L, Noble SM, Cowen LE. Multifactor transcriptional control of alternative oxidase induction integrates diverse environmental inputs to enable fungal virulence. Nat Commun 2023; 14:4528. [PMID: 37500616 PMCID: PMC10374912 DOI: 10.1038/s41467-023-40209-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 07/17/2023] [Indexed: 07/29/2023] Open
Abstract
Metabolic flexibility enables fungi to invade challenging host environments. In Candida albicans, a common cause of life-threatening infections in humans, an important contributor to flexibility is alternative oxidase (Aox) activity. Dramatic induction of this activity occurs under respiratory-stress conditions, which impair the classical electron transport chain (ETC). Here, we show that deletion of the inducible AOX2 gene cripples C. albicans virulence in mice by increasing immune recognition. To investigate further, we examined transcriptional regulation of AOX2 in molecular detail under host-relevant, ETC-inhibitory conditions. We found that multiple transcription factors, including Rtg1/Rtg3, Cwt1/Zcf11, and Zcf2, bind and regulate the AOX2 promoter, conferring thousand-fold levels of inducibility to AOX2 in response to distinct environmental stressors. Further dissection of this complex promoter revealed how integration of stimuli ranging from reactive species of oxygen, nitrogen, and sulfur to reduced copper availability is achieved at the transcriptional level to regulate AOX2 induction and enable pathogenesis.
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Affiliation(s)
- Zhongle Liu
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Pauline Basso
- UCSF Department of Microbiology & Immunology, San Francisco, CA, USA
| | - Saif Hossain
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Sean D Liston
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Nicole Robbins
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Luke Whitesell
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Suzanne M Noble
- UCSF Department of Microbiology & Immunology, San Francisco, CA, USA.
- UCSF Department of Medicine, Division of Infectious Diseases, San Francisco, CA, USA.
| | - Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.
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8
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Alaoufi S, Friskop A, Simsek S. Effect of Field-applied Fungicides on Claviceps purpurea Sclerotia and Associated Toxins in Wheat. J Food Prot 2023; 86:100046. [PMID: 36916553 DOI: 10.1016/j.jfp.2023.100046] [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: 11/19/2022] [Revised: 01/09/2023] [Accepted: 01/18/2023] [Indexed: 01/26/2023]
Abstract
Claviceps purpurea (Fr.) Tul is the causal organism for ergot impacting grass hosts, including wheat. The pathogen produces ergot alkaloids (EAs) during the development of mature sclerotia leading to potential wheat quality discounts or rejection at the point of sale. Cultural practices are recommended for the management of ergot in wheat, but there is limited information pertaining to the use of in-season fungicides to help reduce ergot. The objective of this research was to evaluate the efficacy of four fungicides (prothioconazole + metconazole, pydiflumetofen + propiconazole, azoxystrobin + propiconazole, and fluxapyroxad + pyraclostrobin) on sclerotia characteristics, and EAs associated with C. purpurea. A field experiment was established using a male-sterile hard red spring line with fungicide applications occurring at complete full head emergence (Feekes Growth Stage 10.5). Individual plots were harvested and cleaned, and ergot sclerotia were collected. Physical characteristics and toxin production were examined. Fungicides had a significant (p < .05) impact on total ergot body weight (EBW), with all fungicides having lower EBW than the nontreated control. The fungicide premixture of pydiflumetofen + propiconazole had the lowest EBW among all treatments. Fluxapyroxad + pyraclostrobin had the lowest levels of EAs among fungicides. Results suggest that fungicide premixtures can potentially reduce EBW and influence EA production in wheat.
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Affiliation(s)
- Shatha Alaoufi
- Department of Childhood and Family Studies- College of science and Arts, Qassim University, Ar Rass 58892, Saudi Arabia; Department of Agriculture and Applied Science, North Dakota State University, Fargo, ND 58108, USA.
| | - Andrew Friskop
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108, USA
| | - Senay Simsek
- Department of Agriculture and Applied Science, North Dakota State University, Fargo, ND 58108, USA; Department of Food Science and Whistler Center for Carbohydrate Research, Purdue University, West Lafayette, IN 47907, USA.
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9
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Zeng L, Huang Y, Tan J, Peng J, Hu N, Liu Q, Cao Y, Zhang Y, Chen J, Huang X. QCR7 affects the virulence of Candida albicans and the uptake of multiple carbon sources present in different host niches. Front Cell Infect Microbiol 2023; 13:1136698. [PMID: 36923588 PMCID: PMC10009220 DOI: 10.3389/fcimb.2023.1136698] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 02/09/2023] [Indexed: 03/02/2023] Open
Abstract
Background Candida albicans is a commensal yeast that may cause life-threatening infections. Studies have shown that the cytochrome b-c1 complex subunit 7 gene (QCR7) of C. albicans encodes a protein that forms a component of the mitochondrial electron transport chain complex III, making it an important target for studying the virulence of this yeast. However, to the best of our knowledge, the functions of QCR7 have not yet been characterized. Methods A QCR7 knockout strain was constructed using SN152, and BALb/c mice were used as model animals to determine the role of QCR7 in the virulence of C. albicans. Subsequently, the effects of QCR7 on mitochondrial functions and use of carbon sources were investigated. Next, its mutant biofilm formation and hyphal growth maintenance were compared with those of the wild type. Furthermore, the transcriptome of the qcr7Δ/Δ mutant was compared with that of the WT strain to explore pathogenic mechanisms. Results Defective QCR7 reduced recruitment of inflammatory cells and attenuated the virulence of C. albicans infection in vivo. Furthermore, the mutant influenced the use of multiple alternative carbon sources that exist in several host niches (GlcNAc, lactic acid, and amino acid, etc.). Moreover, it led to mitochondrial dysfunction. Furthermore, the QCR7 knockout strain showed defects in biofilm formation or the maintenance of filamentous growth. The overexpression of cell-surface-associated genes (HWP1, YWP1, XOG1, and SAP6) can restore defective virulence phenotypes and the carbon-source utilization of qcr7Δ/Δ. Conclusion This study provides new insights into the mitochondria-based metabolism of C. albicans, accounting for its virulence and the use of variable carbon sources that promote C. albicans to colonize host niches.
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Affiliation(s)
- Lingbing Zeng
- The First Affiliated Hospital of Nanchang University, School of Public Health, Jiangxi Medical College, Nanchang University, Nanchang, China
- Department of Medical Microbiology, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Yongcheng Huang
- School of Public Health, Jiangxi Medical College, Nanchang University, Nanchang, China
- Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, China
| | - Junjun Tan
- Department of Medical Microbiology, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Jun Peng
- Department of Medical Microbiology, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Niya Hu
- The First Affiliated Hospital of Nanchang University, School of Public Health, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Qiong Liu
- Department of Medical Microbiology, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - YanLi Cao
- Department of Medical Microbiology, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Yuping Zhang
- Department of Medical Microbiology, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Junzhu Chen
- Department of Medical Microbiology, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Xiaotian Huang
- The First Affiliated Hospital of Nanchang University, School of Public Health, Jiangxi Medical College, Nanchang University, Nanchang, China
- Department of Medical Microbiology, Jiangxi Medical College, Nanchang University, Nanchang, China
- School of Public Health, Jiangxi Medical College, Nanchang University, Nanchang, China
- Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, China
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10
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Lv Q, Yan L, Wang J, Feng J, Gao L, Qiu L, Chao W, Qin YL, Jiang Y. Combined Transcriptome and Metabolome Analysis Reveals That the Potent Antifungal Pyrylium Salt Inhibits Mitochondrial Complex I in Candida albicans. Microbiol Spectr 2023; 11:e0320922. [PMID: 36790175 PMCID: PMC10100848 DOI: 10.1128/spectrum.03209-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 01/06/2023] [Indexed: 02/16/2023] Open
Abstract
Based on the structural modification of SM21, xy12, a new pyrylium salt derivative with enhanced antifungal activities, was synthesized. The MICs (MIC90) of xy12 against Candida albicans ranged from 0.125 to 0.25 μg/mL, about 2-fold lower than those of SM21. In addition, xy12 inhibited hypha and biofilm formation in C. albicans in a dose-dependent manner. A total of 3,454 differentially expressed genes and 260 differential metabolites were identified in the xy12-treated C. albicans by RNA-seq and non-targeted metabolomics. By integrating KEGG pathway enrichment analysis, we found that inhibition of oxidative phosphorylation was the important antifungal mechanism of action of xy12. Electron transport through mitochondrial respiratory complexes I to IV is the common process of oxidative phosphorylation. Compared with the sensitivity of the wild-type SC5314 to xy12, decreased sensitivities in mitochondrial complex I (CI)-deficient mutants and increased sensitivities in mitochondrial complex III- and IV-deficient mutants suggested that the antifungal effects of xy12 were dependent on CI. Consistently, xy12 exhibited antagonism with rotenone, an inhibitor of CI, and significantly inhibited the expression and activity of CI. Meanwhile, the phenotypes in the xy12-treated C. albicans were similar to those in the CI-deficient mutants, such as decreased ATP production, reduced mitochondrial membrane potential, loss of mitochondrial DNA, inability to utilize nonfermentative carbon sources, and decreased cell wall N-linked mannoproteins. Collectively, our results revealed that the pyrylium salt xy12 could constrain oxidative phosphorylation by inhibiting mitochondrial complex I in C. albicans, providing a novel lead compound for the development of mitochondria-targeted antifungal drugs. IMPORTANCE The development of new antifungal drugs is critical for solving the problem of antifungal resistance and expanding the limited variety of clinical antifungal drugs. Based on the modification of the pyrylium salt SM21, a new lead compound, xy12, was synthesized which was effective against Candida species both in vitro and in vivo. In this study, conjoined analysis of the transcriptome and metabolome elucidated the antifungal mechanism of action of xy12, which inhibited the activity of mitochondrial complex I in C. albicans. Targeting fungi-specific mitochondrial complex proteins has been reported as a promising antifungal strategy. Our study provided a new lead compound for targeting C. albicans mitochondrial complex I, which could be beneficial for discovering novel antifungal drugs.
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Affiliation(s)
- Quanzhen Lv
- School of Pharmacy, Naval Medical University, Shanghai, People’s Republic of China
| | - Lan Yan
- School of Pharmacy, Naval Medical University, Shanghai, People’s Republic of China
| | - Jinxin Wang
- School of Pharmacy, Naval Medical University, Shanghai, People’s Republic of China
| | - Jia Feng
- Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China
| | - Lu Gao
- Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China
| | - Lijuan Qiu
- School of Pharmacy, Naval Medical University, Shanghai, People’s Republic of China
| | - Wen Chao
- School of Pharmacy, Naval Medical University, Shanghai, People’s Republic of China
| | - Yu-Lin Qin
- Fudan University Minhang Hospital, Shanghai, People’s Republic of China
| | - Yuanying Jiang
- School of Pharmacy, Naval Medical University, Shanghai, People’s Republic of China
- Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China
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11
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Nishida Y, Yanagisawa S, Morita R, Shigematsu H, Shinzawa-Itoh K, Yuki H, Ogasawara S, Shimuta K, Iwamoto T, Nakabayashi C, Matsumura W, Kato H, Gopalasingam C, Nagao T, Qaqorh T, Takahashi Y, Yamazaki S, Kamiya K, Harada R, Mizuno N, Takahashi H, Akeda Y, Ohnishi M, Ishii Y, Kumasaka T, Murata T, Muramoto K, Tosha T, Shiro Y, Honma T, Shigeta Y, Kubo M, Takashima S, Shintani Y. Identifying antibiotics based on structural differences in the conserved allostery from mitochondrial heme-copper oxidases. Nat Commun 2022; 13:7591. [PMID: 36481732 PMCID: PMC9731990 DOI: 10.1038/s41467-022-34771-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 11/07/2022] [Indexed: 12/13/2022] Open
Abstract
Antimicrobial resistance (AMR) is a global health problem. Despite the enormous efforts made in the last decade, threats from some species, including drug-resistant Neisseria gonorrhoeae, continue to rise and would become untreatable. The development of antibiotics with a different mechanism of action is seriously required. Here, we identified an allosteric inhibitory site buried inside eukaryotic mitochondrial heme-copper oxidases (HCOs), the essential respiratory enzymes for life. The steric conformation around the binding pocket of HCOs is highly conserved among bacteria and eukaryotes, yet the latter has an extra helix. This structural difference in the conserved allostery enabled us to rationally identify bacterial HCO-specific inhibitors: an antibiotic compound against ceftriaxone-resistant Neisseria gonorrhoeae. Molecular dynamics combined with resonance Raman spectroscopy and stopped-flow spectroscopy revealed an allosteric obstruction in the substrate accessing channel as a mechanism of inhibition. Our approach opens fresh avenues in modulating protein functions and broadens our options to overcome AMR.
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Affiliation(s)
- Yuya Nishida
- grid.410796.d0000 0004 0378 8307Department of Molecular Pharmacology, National Cerebral and Cardiovascular Center, Suita, Osaka Japan ,grid.136593.b0000 0004 0373 3971Department of Medical Biochemistry, Osaka University Graduate School of Frontier Biological Science, Suita, Osaka Japan
| | - Sachiko Yanagisawa
- grid.266453.00000 0001 0724 9317Graduate School of Science, University of Hyogo, Hyogo, Japan
| | - Rikuri Morita
- grid.20515.330000 0001 2369 4728Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki Japan
| | - Hideki Shigematsu
- grid.472717.0RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo Japan ,grid.410592.b0000 0001 2170 091XPresent Address: Structural Biology Division, Japan Synchrotron Radiation Research Institute, SPring-8; Sayo, Hyogo, Japan
| | - Kyoko Shinzawa-Itoh
- grid.266453.00000 0001 0724 9317Graduate School of Science, University of Hyogo, Hyogo, Japan
| | - Hitomi Yuki
- grid.508743.dRIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa Japan
| | - Satoshi Ogasawara
- grid.136304.30000 0004 0370 1101Department of Chemistry, Graduate School of Science, Chiba University, Inage, Chiba Japan
| | - Ken Shimuta
- grid.410795.e0000 0001 2220 1880Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan ,grid.410795.e0000 0001 2220 1880Antimicrobial Resistance Research Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takashi Iwamoto
- grid.136593.b0000 0004 0373 3971Department of Medical Biochemistry, Osaka University Graduate School of Frontier Biological Science, Suita, Osaka Japan
| | - Chisa Nakabayashi
- grid.410796.d0000 0004 0378 8307Department of Molecular Pharmacology, National Cerebral and Cardiovascular Center, Suita, Osaka Japan ,grid.136593.b0000 0004 0373 3971Department of Medical Biochemistry, Osaka University Graduate School of Frontier Biological Science, Suita, Osaka Japan
| | - Waka Matsumura
- grid.266453.00000 0001 0724 9317Graduate School of Science, University of Hyogo, Hyogo, Japan
| | - Hisakazu Kato
- grid.136593.b0000 0004 0373 3971Department of Medical Biochemistry, Osaka University Graduate School of Frontier Biological Science, Suita, Osaka Japan
| | | | - Takemasa Nagao
- grid.410796.d0000 0004 0378 8307Department of Molecular Pharmacology, National Cerebral and Cardiovascular Center, Suita, Osaka Japan
| | - Tasneem Qaqorh
- grid.410796.d0000 0004 0378 8307Department of Molecular Pharmacology, National Cerebral and Cardiovascular Center, Suita, Osaka Japan ,grid.136593.b0000 0004 0373 3971Department of Medical Biochemistry, Osaka University Graduate School of Frontier Biological Science, Suita, Osaka Japan
| | - Yusuke Takahashi
- grid.410796.d0000 0004 0378 8307Department of Molecular Pharmacology, National Cerebral and Cardiovascular Center, Suita, Osaka Japan
| | - Satoru Yamazaki
- grid.410796.d0000 0004 0378 8307Department of Molecular Pharmacology, National Cerebral and Cardiovascular Center, Suita, Osaka Japan
| | - Katsumasa Kamiya
- grid.419709.20000 0004 0371 3508Center for Basic Education Integrated Learning, Kanagawa Institute of Technology, Atsugi, Kanagawa Japan
| | - Ryuhei Harada
- grid.20515.330000 0001 2369 4728Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki Japan
| | - Nobuhiro Mizuno
- grid.410592.b0000 0001 2170 091XProtein Crystal Analysis Division, Japan Synchrotron Radiation Research Institute, SPring-8, Sayo, Hyogo Japan
| | - Hideyuki Takahashi
- grid.410795.e0000 0001 2220 1880Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yukihiro Akeda
- grid.410795.e0000 0001 2220 1880Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Makoto Ohnishi
- grid.410795.e0000 0001 2220 1880Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yoshikazu Ishii
- grid.265050.40000 0000 9290 9879Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo, Japan
| | - Takashi Kumasaka
- grid.410592.b0000 0001 2170 091XProtein Crystal Analysis Division, Japan Synchrotron Radiation Research Institute, SPring-8, Sayo, Hyogo Japan
| | - Takeshi Murata
- grid.136304.30000 0004 0370 1101Department of Chemistry, Graduate School of Science, Chiba University, Inage, Chiba Japan
| | - Kazumasa Muramoto
- grid.266453.00000 0001 0724 9317Graduate School of Science, University of Hyogo, Hyogo, Japan
| | - Takehiko Tosha
- grid.472717.0RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo Japan
| | - Yoshitsugu Shiro
- grid.266453.00000 0001 0724 9317Graduate School of Science, University of Hyogo, Hyogo, Japan
| | - Teruki Honma
- grid.508743.dRIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa Japan
| | - Yasuteru Shigeta
- grid.20515.330000 0001 2369 4728Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki Japan
| | - Minoru Kubo
- grid.266453.00000 0001 0724 9317Graduate School of Science, University of Hyogo, Hyogo, Japan
| | - Seiji Takashima
- grid.136593.b0000 0004 0373 3971Department of Medical Biochemistry, Osaka University Graduate School of Frontier Biological Science, Suita, Osaka Japan
| | - Yasunori Shintani
- grid.410796.d0000 0004 0378 8307Department of Molecular Pharmacology, National Cerebral and Cardiovascular Center, Suita, Osaka Japan ,grid.136593.b0000 0004 0373 3971Department of Medical Biochemistry, Osaka University Graduate School of Frontier Biological Science, Suita, Osaka Japan
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12
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Transcriptomics and Phenotyping Define Genetic Signatures Associated with Echinocandin Resistance in Candida auris. mBio 2022; 13:e0079922. [PMID: 35968956 PMCID: PMC9426441 DOI: 10.1128/mbio.00799-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Candida auris emerged as a human fungal pathogen only during the past decade. Remarkably, C. auris displays high degrees of genomic diversity and phenotypic plasticity, with four major clades causing hospital outbreaks with high mortality and morbidity rates. C. auris can show clinical resistance to all classes of antifungal drugs, including echinocandins that are usually recommended as first-line therapies for invasive candidiasis. Here, we exploit transcriptomics coupled with phenotypic profiling to characterize a set of clinical C. auris isolates displaying pronounced echinocandin resistance (ECN-R). A hot spot mutation in the echinocandin FKS1 target gene is present in all resistant isolates. Moreover, ECN-R strains share a core signature set of 362 genes differentially expressed in ECN-R isolates. Among others, mitochondrial gene expression and genes affecting cell wall function appear to be the most prominent, with the latter correlating well with enhanced adhesive traits, increased cell wall mannan content, and altered sensitivity to cell wall stress of ECN-R isolates. Moreover, ECN-R phenotypic signatures were also linked to pathogen recognition and interaction with immune cells. Hence, transcriptomics paired with phenotyping is a suitable tool to predict resistance and fitness traits as well as treatment outcomes in pathogen populations with complex phenotypic diversity. IMPORTANCE The surge in antimicrobial drug resistance in some bacterial and fungal pathogens constitutes a significant challenge to health care facilities. The emerging human fungal pathogen Candida auris has been particularly concerning, as isolates can display pan-antifungal resistance traits against all drugs, including echinocandins. However, the mechanisms underlying this phenotypic diversity remain poorly understood. We identify transcriptomic signatures in C. auris isolates resistant to otherwise fungicidal echinocandins. We identify a set of differentially expressed genes shared by resistant strains compared to unrelated susceptible isolates. Moreover, phenotyping demonstrates that resistant strains show distinct behaviors, with implications for host-pathogen interactions. Hence, this work provides a solid basis to identify the mechanistic links between antifungal multidrug resistance and fitness costs that affect the interaction of C. auris with host immune defenses.
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13
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Ma M, Muhammad S, Duan J, Bai L, Li H. Impairment of Respiratory Chain Function and Involvement of Alternative Respiratory Pathway in Mitochondria of Potato Tubers Infected by Pectobacteriumcarotovorum subsp. carotovorum. Foods 2022; 11:foods11111574. [PMID: 35681324 PMCID: PMC9180382 DOI: 10.3390/foods11111574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/19/2022] [Accepted: 05/20/2022] [Indexed: 02/04/2023] Open
Abstract
The significance of alternative respiratory pathway (AOXs) during the interaction between soft rot bacteria (Pectobacterium carotovorum subsp. carotovorum, (Pcc.)) and potato tubers is well-defined. However, the role of the AOXs in impaired mitochondrial respiratory chain function during the Pcc. infection is yet to be studied. In this study, the results show that with the aggravation of infection of Pcc., the capacity for alternative respiration in mitochondria of potato tubers increased gradually. The mitochondrial membrane potential increased more significantly after infection with Pcc. when the AOXs in potato tubers was partially blocked using salicylhydroxamic acid (SHAM) beforehand. In addition, the activity of complex III decreased more drastically while the activity of complex IV increased more significantly in the partial absence of the AOXs in the mitochondria. Furthermore, the mitochondrial endogenous respiration, mitochondrial respiratory state 3 and respiratory control rate (RCR) decreased more significantly and the value of RCR reached around 1.0 with the aggravation of infection of Pcc. in the partially absence of AOXs in the mitochondria.
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Affiliation(s)
| | | | | | | | - Hongyu Li
- Correspondence: ; Tel.: +86-931-891-2560
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14
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Selective Metal Chelation by a Thiosemicarbazone Derivative Interferes with Mitochondrial Respiration and Ribosome Biogenesis in Candida albicans. Microbiol Spectr 2022; 10:e0195121. [PMID: 35412374 PMCID: PMC9241695 DOI: 10.1128/spectrum.01951-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Metal chelation is generally considered as a promising antifungal approach but its specific mechanisms are unclear. Here, we identify 13 thiosemicarbazone derivatives that exert broad-spectrum antifungal activity with potency comparable or superior to that of fluconazole in vitro by screening a small compound library comprising 89 thiosemicarbazone derivatives as iron chelators. Among the hits, 19ak exhibits minimal cytotoxicity and potent activity against either azole-sensitive or azole-resistant fungal pathogens. Mechanism investigations reveal that 19ak inhibits mitochondrial respiration mainly by retarding mitochondrial respiratory chain complex I activity through iron chelation, and further reduces mitochondrial membrane potential and ATP synthesis in Candida albicans. In addition, 19ak inhibits fungal ribosome biogenesis mainly by disrupting intracellular zinc homeostasis. 19ak also stimulates the activities of antioxidant enzymes and decreases reactive oxygen species formation in C. albicans, resulting in an increase in detrimental intracellular reductive stress. However, 19ak has minor effects on mammalian cells in depleting intracellular iron and zinc. Moreover, 19ak exhibits low capacity to induce drug resistance and in vivo efficacy in a Galleria mellonella infection model. These findings uncover retarded fungal mitochondrial respiration and ribosome biogenesis as downstream effects of disruption of iron and zinc homeostasis in C. albicans and provide a basis for the thiosemicarbazone 19ak in antifungal application. IMPORTANCE The increasing incidence of fungal infections and resistance to existing antifungals call for the development of broad-spectrum antifungals with novel mechanisms of action. In this study, we demonstrate that a thiosemicarbazone derivative 19ak selectively inhibits mitochondrial respiration mainly by retarding mitochondrial respiratory chain complex I activity through iron chelation and inhibits ribosome biogenesis mainly by disrupting intracellular zinc homeostasis in C. albicans. In addition, 19ak exhibits low capacity to induce fungal resistance, minimal cytotoxicity, and in vivo antifungal efficacy. This study provides the basis of thiosemicarbazone derivative 19ak as a metal chelator for the treatment of fungal infections.
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15
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Targeting the ATP synthase in bacterial and fungal pathogens – beyond Mycobacterium tuberculosis. J Glob Antimicrob Resist 2022; 29:29-41. [DOI: 10.1016/j.jgar.2022.01.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 01/24/2022] [Accepted: 01/30/2022] [Indexed: 11/23/2022] Open
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16
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Jin X, Zhang M, Lu J, Duan X, Chen J, Liu Y, Chang W, Lou H. Hinokitiol chelates intracellular iron to retard fungal growth by disturbing mitochondrial respiration. J Adv Res 2022; 34:65-77. [PMID: 35024181 PMCID: PMC8655124 DOI: 10.1016/j.jare.2021.06.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 06/01/2021] [Accepted: 06/15/2021] [Indexed: 12/30/2022] Open
Abstract
Introduction The increasing morbidity of fungal infections and the prevalence of drug resistance highlighted the discovery of novel antifungal agents and investigation of their modes of action. Iron chelators have been used to treat superficial fungal infections or potentiate the efficacy of certain antifungal drugs. Hinokitiol exhibits potent antifungal activity and iron-chelating ability. However, their relationships have not been established. Objectives This study aims to explore the selectivity of hinokitiol against fungal cells and mammalian cells and determine the role of iron-chelating for the antifungal activity of hinokitiol. Methods Iron probe FeRhonox-1 was used to determine intracellular Fe2+ content. 5-Cyano-2,3-ditolyl tetrazolium chloride probe and Cell Counting Kit-8 were used to detect the mitochondrial respiratory activities. Quantitative real-time PCR and rescue experiments were performed to determine the effect of iron on the antifungal activity of hinokitiol. The effects of hinokitiol on fungal mitochondria were further evaluated using reactive oxygen species probes and several commercial Assay Kits. The ability of hinokitiol to induce resistance in Candida species was carried out using a serial passage method. The in vivo therapeutic effect of hinokitiol was evaluated using Galleria mellonella as an infectious model. Results Hinokitiol was effective against a panel of Candida strains with multiple azole-resistant mechanisms and persistently inhibited Candida albicans growth. Mechanism investigations revealed that hinokitiol chelated fungal intracellular iron and inhibited the respiration of fungal cells but had minor effects on mammalian cells. Hinokitiol further inhibited the activities of mitochondrial respiratory chain complexes I and II and reduced mitochondrial membrane potential, thereby decreasing intracellular ATP synthesis and increasing detrimental intracellular reductive stress. Moreover, hinokitiol exhibited low potential for inducing resistance in several Candida species and greatly improved the survival of Candida-infected Galleria mellonella. Conclusions These findings suggested the potential application of hinokitiol as an iron chelator to treat fungal infections.
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Affiliation(s)
- Xueyang Jin
- Department of Natural Product Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Ming Zhang
- Institute of Medical Science, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Jinghui Lu
- Department of Natural Product Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Ximeng Duan
- Department of Natural Product Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Jinyao Chen
- Department of Natural Product Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Yue Liu
- Department of Natural Product Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Wenqiang Chang
- Department of Natural Product Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Hongxiang Lou
- Department of Natural Product Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
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17
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Takács-Vellai K, Farkas Z, Ősz F, Stewart GW. Model systems in SDHx-related pheochromocytoma/paraganglioma. Cancer Metastasis Rev 2021; 40:1177-1201. [PMID: 34957538 PMCID: PMC8825606 DOI: 10.1007/s10555-021-10009-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 12/04/2021] [Indexed: 11/17/2022]
Abstract
Pheochromocytoma (PHEO) and paraganglioma (PGL) (together PPGL) are tumors with poor outcomes that arise from neuroendocrine cells in the adrenal gland, and sympathetic and parasympathetic ganglia outside the adrenal gland, respectively. Many follow germline mutations in genes coding for subunits of succinate dehydrogenase (SDH), a tetrameric enzyme in the tricarboxylic acid (TCA) cycle that both converts succinate to fumarate and participates in electron transport. Germline SDH subunit B (SDHB) mutations have a high metastatic potential. Herein, we review the spectrum of model organisms that have contributed hugely to our understanding of SDH dysfunction. In Saccharomyces cerevisiae (yeast), succinate accumulation inhibits alpha-ketoglutarate-dependent dioxygenase enzymes leading to DNA demethylation. In the worm Caenorhabditis elegans, mutated SDH creates developmental abnormalities, metabolic rewiring, an energy deficit and oxygen hypersensitivity (the latter is also found in Drosophila melanogaster). In the zebrafish Danio rerio, sdhb mutants display a shorter lifespan with defective energy metabolism. Recently, SDHB-deficient pheochromocytoma has been cultivated in xenografts and has generated cell lines, which can be traced back to a heterozygous SDHB-deficient rat. We propose that a combination of such models can be efficiently and effectively used in both pathophysiological studies and drug-screening projects in order to find novel strategies in PPGL treatment.
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Affiliation(s)
| | - Zsolt Farkas
- Department of Biological Anthropology, Eötvös Loránd University, Budapest, Hungary
| | - Fanni Ősz
- Department of Biological Anthropology, Eötvös Loránd University, Budapest, Hungary
| | - Gordon W Stewart
- Division of Medicine, University College London, Gower Street, London, WC1E 6BT, UK
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18
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In Vitro Anti-Biofilm Activity of Hydrogen-Peroxide Generating Electrochemical Bandage Against Yeast Biofilms. Antimicrob Agents Chemother 2021; 66:e0179221. [PMID: 34930030 DOI: 10.1128/aac.01792-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Wound infections are caused by bacteria and/or fungi. The presence of fungal biofilms in wound beds presents a unique challenge, as fungal biofilms may be difficult to eradicate. The goal of this work was to assess the in vitro anti-biofilm activity of a H2O2-producing electrochemical bandage (e-bandage) against 15 yeast isolates representing commonly-encountered species. Time-dependent decreases in viable biofilm CFU counts of all isolates tested were observed, resulting in no visible colonies with 48 hours of exposure by plate culture. Fluorescence microscopic analysis showed extensive cell membrane damage of biofilm cells after e-bandage treatment. Reductions in intracellular ATP levels of yeast biofilm cells were recorded post e-bandage treatment. Our results suggest that exposure to H2O2-producing e-bandages reduce in vitro viable cell counts of yeast biofilms, making this a potential new topical treatment approach for fungal wound infections.
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19
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Liu T, Pyle AM. Discovery of highly reactive self-splicing group II introns within the mitochondrial genomes of human pathogenic fungi. Nucleic Acids Res 2021; 49:12422-12432. [PMID: 34850132 PMCID: PMC8643640 DOI: 10.1093/nar/gkab1077] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/27/2021] [Accepted: 10/20/2021] [Indexed: 11/25/2022] Open
Abstract
Fungal pathogens represent an expanding global health threat for which treatment options are limited. Self-splicing group II introns have emerged as promising drug targets, but their development has been limited by a lack of information on their distribution and architecture in pathogenic fungi. To meet this challenge, we developed a bioinformatic workflow for scanning sequence data to identify unique RNA structural signatures within group II introns. Using this approach, we discovered a set of ubiquitous introns within thermally dimorphic fungi (genera of Blastomyces, Coccidioides and Histoplasma). These introns are the most biochemically reactive group II introns ever reported, and they self-splice rapidly under near-physiological conditions without protein cofactors. Moreover, we demonstrated the small molecule targetability of these introns by showing that they can be inhibited by the FDA-approved drug mitoxantrone in vitro. Taken together, our results highlight the utility of structure-based informatic searches for identifying riboregulatory elements in pathogens, revealing a striking diversity of reactive self-splicing introns with great promise as antifungal drug targets.
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Affiliation(s)
- Tianshuo Liu
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, 06520, USA
| | - Anna M Pyle
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, 06520, USA.,Department of Chemistry, Yale University, New Haven, CT, 06520, USA.,Howard Hughes Medical Institute, Yale University, New Haven, CT, 06520, USA
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20
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The SPFH Protein Superfamily in Fungi: Impact on Mitochondrial Function and Implications in Virulence. Microorganisms 2021; 9:microorganisms9112287. [PMID: 34835412 PMCID: PMC8624314 DOI: 10.3390/microorganisms9112287] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/28/2021] [Accepted: 11/01/2021] [Indexed: 11/17/2022] Open
Abstract
Integral membrane proteins from the ancient SPFH (stomatin, prohibitin, flotillin, HflK/HflC) protein superfamily are found in nearly all living organisms. Mammalian SPFH proteins are primarily associated with mitochondrial functions but also coordinate key processes such as ion transport, signaling, and mechanosensation. In addition, SPFH proteins are required for virulence in parasites. While mitochondrial functions of SPFH proteins are conserved in fungi, recent evidence has uncovered additional roles for SPFH proteins in filamentation and stress signaling. Inhibitors that target SPFH proteins have been successfully used in cancer and inflammation treatment. Thus, SPFH proteins may serve as a potential target for novel antifungal drug development. This review article surveys SPFH function in various fungal species with a special focus on the most common human fungal pathogen, Candida albicans.
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Xu F, Copsey AC, Young L, Barsottini MRO, Albury MS, Moore AL. Comparison of the Kinetic Parameters of Alternative Oxidases From Trypanosoma brucei and Arabidopsis thaliana-A Tale of Two Cavities. FRONTIERS IN PLANT SCIENCE 2021; 12:744218. [PMID: 34745175 PMCID: PMC8569227 DOI: 10.3389/fpls.2021.744218] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 09/21/2021] [Indexed: 05/27/2023]
Abstract
The alternative oxidase (AOX) is widespread in plants, fungi, and some protozoa. While the general structure of the AOX remains consistent, its overall activity, sources of kinetic activation and their sensitivity to inhibitors varies between species. In this study, the recombinant Trypanosoma brucei AOX (rTAO) and Arabidopsis thaliana AOX1A (rAtAOX1A) were expressed in the Escherichia coli ΔhemA mutant FN102, and the kinetic parameters of purified AOXs were compared. Results showed that rTAO possessed the highest V max and K m for quinol-1, while much lower V max and K m were observed in the rAtAOX1A. The catalytic efficiency (k cat/K m) of rTAO was higher than that of rAtAOX1A. The rTAO also displayed a higher oxygen affinity compared to rAtAOX1A. It should be noted that rAtAOX1a was sensitive to α-keto acids while rTAO was not. Nevertheless, only pyruvate and glyoxylate can fully activate Arabidopsis AOX. In addition, rTAO and rAtAOX1A showed different sensitivity to AOX inhibitors, with ascofuranone (AF) being the best inhibitor against rTAO, while colletochlorin B (CB) appeared to be the most effective inhibitor against rAtAOX1A. Octylgallate (OG) and salicylhydroxamic acid (SHAM) are less effective than the other inhibitors against protist and plant AOX. A Caver analysis indicated that the rTAO and rAtAOX1A differ with respect to the mixture of polar residues lining the hydrophobic cavity, which may account for the observed difference in kinetic and inhibitor sensitivities. The data obtained in this study are not only beneficial for our understanding of the variation in the kinetics of AOX within protozoa and plants but also contribute to the guidance for the future development of phytopathogenic fungicides.
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Hossain S, Veri AO, Liu Z, Iyer KR, O’Meara TR, Robbins N, Cowen LE. Mitochondrial perturbation reduces susceptibility to xenobiotics through altered efflux in Candida albicans. Genetics 2021; 219:iyab095. [PMID: 34143207 PMCID: PMC8860387 DOI: 10.1093/genetics/iyab095] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 06/07/2021] [Indexed: 11/13/2022] Open
Abstract
Candida albicans is a leading human fungal pathogen, which can cause superficial infections or life-threatening systemic disease in immunocompromised individuals. The ability to transition between yeast and filamentous forms is a major virulence trait of C. albicans, and a key regulator of this morphogenetic transition is the molecular chaperone Hsp90. To explore the mechanisms governing C. albicans morphogenesis in response to Hsp90 inhibition, we performed a functional genomic screen using the gene replacement and conditional expression collection to identify mutants that are defective in filamentation in response to the Hsp90 inhibitor, geldanamycin. We found that transcriptional repression of genes involved in mitochondrial function blocked filamentous growth in response to the concentration of the Hsp90 inhibitor used in the screen, and this was attributable to increased resistance to the compound. Further exploration revealed that perturbation of mitochondrial function reduced susceptibility to two structurally distinct Hsp90 inhibitors, geldanamycin and radicicol, such that filamentous growth was restored in the mitochondrial mutants by increasing the compound concentration. Deletion of two representative mitochondrial genes, MSU1 and SHY1, enhanced cellular efflux and reduced susceptibility to diverse intracellularly acting compounds. Additionally, screening a C. albicans efflux pump gene deletion library implicated Yor1 in the efflux of geldanamycin and Cdr1, in the efflux of radicicol. Deletion of these transporter genes restored sensitivity to Hsp90 inhibitors in MSU1 and SHY1 homozygous deletion mutants, thereby enabling filamentation. Taken together, our findings suggest that mitochondrial dysregulation elevates cellular efflux and consequently reduces susceptibility to xenobiotics in C. albicans.
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Affiliation(s)
- Saif Hossain
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S, Canada
| | - Amanda O Veri
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S, Canada
| | - Zhongle Liu
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S, Canada
| | - Kali R Iyer
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S, Canada
| | - Teresa R O’Meara
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Nicole Robbins
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S, Canada
| | - Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S, Canada
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Discovery of Fungus-Specific Targets and Inhibitors Using Chemical Phenotyping of Pathogenic Spore Germination. mBio 2021; 12:e0167221. [PMID: 34311572 PMCID: PMC8406298 DOI: 10.1128/mbio.01672-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
There is a critical need for new antifungal drugs; however, the lack of available fungus-specific targets is a major hurdle in the development of antifungal therapeutics. Spore germination is a differentiation process absent in humans that could harbor uncharacterized fungus-specific targets. To capitalize on this possibility, we developed novel phenotypic assays to identify and characterize inhibitors of spore germination of the human fungal pathogen Cryptococcus. Using these assays, we carried out a high-throughput screen of ∼75,000 drug-like small molecules and identified and characterized 191 novel inhibitors of spore germination, many of which also inhibited yeast replication and demonstrated low cytotoxicity against mammalian cells. Using an automated, microscopy-based, quantitative germination assay (QGA), we discovered that germinating spore populations can exhibit unique phenotypes in response to chemical inhibitors. Through the characterization of these spore population dynamics in the presence of the newly identified inhibitors, we classified 6 distinct phenotypes based on differences in germination synchronicity, germination rates, and overall population behavior. Similar chemical phenotypes were induced by inhibitors that targeted the same cellular function or had shared substructures. Leveraging these features, we used QGAs to identify outliers among compounds that fell into similar structural groups and thus refined relevant structural moieties, facilitating target identification. This approach led to the identification of complex II of the electron transport chain as the putative target of a promising structural cluster of germination inhibitory compounds. These inhibitors showed high potency against Cryptococcus spore germination while maintaining low cytotoxicity against mammalian cells, making them prime candidates for development into novel antifungal therapeutics.
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Black B, Lee C, Horianopoulos LC, Jung WH, Kronstad JW. Respiring to infect: Emerging links between mitochondria, the electron transport chain, and fungal pathogenesis. PLoS Pathog 2021; 17:e1009661. [PMID: 34237096 PMCID: PMC8266039 DOI: 10.1371/journal.ppat.1009661] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- Braydon Black
- Michael Smith Laboratories, Department of Microbiology & Immunology, University of British Columbia, Vancouver, Canada
| | - Christopher Lee
- Michael Smith Laboratories, Department of Microbiology & Immunology, University of British Columbia, Vancouver, Canada
| | - Linda C. Horianopoulos
- Michael Smith Laboratories, Department of Microbiology & Immunology, University of British Columbia, Vancouver, Canada
| | - Won Hee Jung
- Department of Systems Biotechnology, Chung-Ang University, Anseong, Republic of Korea
| | - James W. Kronstad
- Michael Smith Laboratories, Department of Microbiology & Immunology, University of British Columbia, Vancouver, Canada
- * E-mail:
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Chang CK, Kao MC, Lan CY. Antimicrobial Activity of the Peptide LfcinB15 against Candida albicans. J Fungi (Basel) 2021; 7:jof7070519. [PMID: 34209722 PMCID: PMC8306953 DOI: 10.3390/jof7070519] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/24/2021] [Accepted: 06/25/2021] [Indexed: 02/07/2023] Open
Abstract
Lactoferricin (Lfcin) is an amphipathic, cationic peptide derived from proteolytic cleavage of the N-lobe of lactoferrin (Lf). Lfcin and its derivatives possess broad-spectrum antibacterial and antifungal activities. However, unlike their antibacterial functions, the modes of action of Lfcin and its derivatives against pathogenic fungi are less well understood. In this study, the mechanisms of LfcinB15, a derivative of bovine Lfcin, against Candida albicans were, therefore, extensively investigated. LfcinB15 exhibited inhibitory activity against planktonic cells, biofilm cells, and clinical isolates of C. albicans and non-albicans Candida species. We further demonstrated that LfcinB15 is localized on the cell surface and vacuoles of C. albicans cells. Moreover, LfcinB15 uses several different methods to kill C. albicans, including disturbing the cell membrane, inducing reactive oxygen species (ROS) generation, and causing mitochondrial dysfunction. Finally, the Hog1 and Mkc1 mitogen-activated protein kinases were both activated in C. albicans cells in response to LfcinB15. These findings help us to obtain more insight into the complex mechanisms used by LfcinB15 and other Lfcin-derived peptides to fight fungal pathogens.
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Affiliation(s)
- Che-Kang Chang
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 30013, Taiwan;
| | - Mou-Chieh Kao
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Life Science, National Tsing Hua University, Hsinchu 30013, Taiwan
- Correspondence: (M.-C.K.); ; (C.-Y.L.); Tel.: +886-3-5742473 (M.-C.K.); +886-3-5742472 (C.-Y.L.)
| | - Chung-Yu Lan
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 30013, Taiwan;
- Department of Life Science, National Tsing Hua University, Hsinchu 30013, Taiwan
- Correspondence: (M.-C.K.); ; (C.-Y.L.); Tel.: +886-3-5742473 (M.-C.K.); +886-3-5742472 (C.-Y.L.)
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Amobonye A, Bhagwat P, Ranjith D, Mohanlall V, Pillai S. Characterisation, pathogenicity and hydrolytic enzyme profiling of selected Fusarium species and their inhibition by novel coumarins. Arch Microbiol 2021; 203:3495-3508. [PMID: 33912984 DOI: 10.1007/s00203-021-02335-1] [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: 01/17/2021] [Revised: 04/12/2021] [Accepted: 04/13/2021] [Indexed: 11/30/2022]
Abstract
Three Fusarium species isolated locally were characterised by the amplification of their rDNA ITS region, host specificity, and hydrolytic enzyme production. The strains were identified as Fusarium pseudoanthophilum, which is being reported for the first time in South Africa, as well as F. foetens and F. fujikuroi. All the three strains were capable of infecting vegetables such as tomatoes, bell and cayenne peppers, belonging to the Solanaceae family. The Fusarium strains also showed significant production of cell wall degrading enzymes in vitro, such as amylase, cellulase, xylanase, and polygalacturonase, thus highlighting the possibilities of these enzymes as pathogenic factors. Subsequently, the strains were discovered to be susceptible to three halogenated coumarins. The most effective of the tested coumarins, 6-bromo3-2,2-dibromoacetyl-2H-chromen-2-one, showed MIC values of 0.125, 0.0625 and 0.125 mg/ml against F. foetens, F. pseudoanthophilum and F. fujikuroi, respectively. The antifungal potentials of the halogenated coumarins were confirmed in silico through PASS analysis, toxicity prediction and docking studies. Findings from this study demonstrate the use of these coumarins as potential control agents against the Fusarium species and other pathogenic fungi in general.
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Affiliation(s)
- Ayodeji Amobonye
- Department of Biotechnology and Food Science, Faculty of Applied Sciences, Durban University of Technology, P.O. BOX 1334, Durban, 4000, South Africa
| | - Prashant Bhagwat
- Department of Biotechnology and Food Science, Faculty of Applied Sciences, Durban University of Technology, P.O. BOX 1334, Durban, 4000, South Africa
| | - Divona Ranjith
- Department of Biotechnology and Food Science, Faculty of Applied Sciences, Durban University of Technology, P.O. BOX 1334, Durban, 4000, South Africa
| | - Viresh Mohanlall
- Department of Biotechnology and Food Science, Faculty of Applied Sciences, Durban University of Technology, P.O. BOX 1334, Durban, 4000, South Africa
| | - Santhosh Pillai
- Department of Biotechnology and Food Science, Faculty of Applied Sciences, Durban University of Technology, P.O. BOX 1334, Durban, 4000, South Africa.
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Ke CL, Liao YT, Lin CH. MSS2 maintains mitochondrial function and is required for chitosan resistance, invasive growth, biofilm formation and virulence in Candida albicans. Virulence 2021; 12:281-297. [PMID: 33427576 PMCID: PMC7808435 DOI: 10.1080/21505594.2020.1870082] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Candida albicans is the most prevalent fungal pathogen in humans, particularly in immunocompromised patients. In this study, by screening a C. albicans mutant library, we first identified that the MSS2 gene, an ortholog of Saccharomyces cerevisiae MSS2 required for mitochondrial respiration, mediates chitosan resistance. Upon treatment with 0.2% chitosan, the growth of mss2Δ strains was strikingly impaired, and MSS2 expression was significantly repressed by chitosan. Furthermore, mss2Δ strains exhibited slow growth on medium supplemented with glycerol as the sole carbon source. Similar to the chitosan-treated wild-type strain, the mss2Δ strain exhibited a significantly impaired ATP production ability. These data suggest that an antifungal mechanism of chitosan against C. albicans acts by inhibiting MSS2 gene expression, leading to repression of mitochondrial function. Normal respiratory function is suggested to be required for fungal virulence. Interestingly, the mss2Δ mutant strains exhibited significantly impaired invasive ability in vitro and ex vivo but retained normal hyphal development ability in liquid medium. Furthermore, the MSS2 deletion strains could not form robust biofilms and exhibited significantly reduced virulence. Collectively, these results demonstrated that the antifungal effect of chitosan against C. albicans is mediated via inhibition of mitochondrial biogenesis. These data may provide another strategy for antifungal drug development via inhibition of fungal mitochondria.
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Affiliation(s)
- Cai-Ling Ke
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University , Taipei, Taiwan
| | - Yu-Ting Liao
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University , Taipei, Taiwan
| | - Ching-Hsuan Lin
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University , Taipei, Taiwan
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Moreno C, Santos RM, Burns R, Zhang WC. Succinate Dehydrogenase and Ribonucleic Acid Networks in Cancer and Other Diseases. Cancers (Basel) 2020; 12:cancers12113237. [PMID: 33153035 PMCID: PMC7693138 DOI: 10.3390/cancers12113237] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/24/2020] [Accepted: 10/30/2020] [Indexed: 02/07/2023] Open
Abstract
Simple Summary Although the dysfunction of the succinate dehydrogenase complex in mitochondria leads to cancer and other diseases due to aberrant metabolic reactions and signaling pathways, it is not well known how the succinate dehydrogenase complex is regulated. Our review highlights that non-coding ribonucleic acids (RNAs), RNA editing enzymes, and RNA modifying enzymes regulate expressions and functions of the succinate dehydrogenase complex. This research will provide new strategies for treating succinate dehydrogenase-relevant diseases in a clinic. Abstract Succinate dehydrogenase (SDH) complex connects both the tricarboxylic acid (TCA) cycle and the electron transport chain (ETC) in the mitochondria. However, SDH mutation or dysfunction-induced succinate accumulation results in multiple cancers and non-cancer diseases. The mechanistic studies show that succinate activates hypoxia response and other signal pathways via binding to 2-oxoglutarate-dependent oxygenases and succinate receptors. Recently, the increasing knowledge of ribonucleic acid (RNA) networks, including non-coding RNAs, RNA editors, and RNA modifiers has expanded our understanding of the interplay between SDH and RNA networks in cancer and other diseases. Here, we summarize recent discoveries in the RNA networks and their connections to SDH. Additionally, we discuss current therapeutics targeting SDH in both pre-clinical and clinical trials. Thus, we propose a new model of SDH–RNA network interaction and bring promising RNA therapeutics against SDH-relevant cancer and other diseases.
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Song J, Zhou J, Zhang L, Li R. Mitochondria-Mediated Azole Drug Resistance and Fungal Pathogenicity: Opportunities for Therapeutic Development. Microorganisms 2020; 8:E1574. [PMID: 33066090 PMCID: PMC7600254 DOI: 10.3390/microorganisms8101574] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/09/2020] [Accepted: 10/09/2020] [Indexed: 12/16/2022] Open
Abstract
In recent years, the role of mitochondria in pathogenic fungi in terms of azole resistance and fungal pathogenicity has been a rapidly developing field. In this review, we describe the molecular mechanisms by which mitochondria are involved in regulating azole resistance and fungal pathogenicity. Mitochondrial function is involved in the regulation of drug efflux pumps at the transcriptional and posttranslational levels. On the one hand, defects in mitochondrial function can serve as the signal leading to activation of calcium signaling and the pleiotropic drug resistance pathway and, therefore, can globally upregulate the expression of drug efflux pump genes, leading to azole drug resistance. On the other hand, mitochondria also contribute to azole resistance through modulation of drug efflux pump localization and activity. Mitochondria further contribute to azole resistance through participating in iron homeostasis and lipid biosynthesis. Additionally, mitochondrial dynamics play an important role in azole resistance. Meanwhile, mitochondrial morphology is important for fungal virulence, playing roles in growth in stressful conditions in a host. Furthermore, there is a close link between mitochondrial respiration and fungal virulence, and mitochondrial respiration plays an important role in morphogenetic transition, hypoxia adaptation, and cell wall biosynthesis. Finally, we discuss the possibility for targeting mitochondrial factors for the development of antifungal therapies.
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Affiliation(s)
- Jinxing Song
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province and School of Life Science, Jiangsu Normal University, Xuzhou, Jiangsu 221116, China;
- Shandong Provincial Key Laboratory of Infection and Immunity, Jinan 250012, China;
| | - Jingwen Zhou
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province and School of Life Science, Jiangsu Normal University, Xuzhou, Jiangsu 221116, China;
| | - Lei Zhang
- Shandong Provincial Key Laboratory of Infection and Immunity, Jinan 250012, China;
| | - Rongpeng Li
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province and School of Life Science, Jiangsu Normal University, Xuzhou, Jiangsu 221116, China;
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Inhibition of Respiration of Candida albicans by Small Molecules Increases Phagocytosis Efficacy by Macrophages. mSphere 2020; 5:5/2/e00016-20. [PMID: 32295866 PMCID: PMC7160677 DOI: 10.1128/msphere.00016-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Candida albicans adapts to various conditions in different body niches by regulating gene expression, protein synthesis, and metabolic pathways. These adaptive reactions not only allow survival but also influence the interaction with host cells, which is governed by the composition and structure of the fungal cell wall. Numerous studies had shown linkages between mitochondrial functionality, cell wall integrity and structure, and pathogenicity. Thus, we decided to inhibit single complexes of the respiratory chain of C. albicans and to analyze the resultant interaction with macrophages via their phagocytic activity. Remarkably, inhibition of the fungal bc1 complex by antimycin A increased phagocytosis, which correlated with an increased accessibility of β-glucans. To contribute to mechanistic insights, we performed metabolic studies, which highlighted significant changes in the abundance of constituents of the plasma membrane. Collectively, our results reinforce the strong linkage between fungal energy metabolism and other components of fungal physiology, which also determine the vulnerability to immune defense reactions.IMPORTANCE The yeast Candida albicans is one of the major fungal human pathogens, for which new therapeutic approaches are required. We aimed at enhancements of the phagocytosis efficacy of macrophages by targeting the cell wall structure of C. albicans, as the coverage of the β-glucan layer by mannans is one of the immune escape mechanisms of the fungus. We unambiguously show that inhibition of the fungal bc1 complex correlates with increased accessibilities of β-glucans and improved phagocytosis efficiency. Metabolic studies proved not only the known direct effects on reactive oxygen species (ROS) production and fermentative pathways but also the clear downregulation of the ergosterol pathway and upregulation of unsaturated fatty acids. The changed composition of the plasma membrane could also influence the interaction with the overlying cell wall. Thus, our work highlights the far-reaching relevance of energy metabolism, indirectly also for host-pathogen interactions, without affecting viability.
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Pellon A, Sadeghi Nasab SD, Moyes DL. New Insights in Candida albicans Innate Immunity at the Mucosa: Toxins, Epithelium, Metabolism, and Beyond. Front Cell Infect Microbiol 2020; 10:81. [PMID: 32195196 PMCID: PMC7062647 DOI: 10.3389/fcimb.2020.00081] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 02/18/2020] [Indexed: 12/16/2022] Open
Abstract
The mucosal surfaces of the human body are challenged by millions of microbes on a daily basis. Co-evolution with these microbes has led to the development of plastic mechanisms in both host and microorganisms that regulate the balance between preserving beneficial microbes and clearing pathogens. Candida albicans is a fungal pathobiont present in most healthy individuals that, under certain circumstances, can become pathogenic and cause everything from mild mucosal infections to life-threatening systemic diseases. As an essential part of the innate immunity in mucosae, epithelial cells elaborate complex immune responses that discriminate between commensal and pathogenic microbes, including C. albicans. Recently, several significant advances have been made identifying new pieces in the puzzle of host-microbe interactions. This review will summarize these advances in the context of our current knowledge of anti-Candida mucosal immunity, and their impact on epithelial immune responses to this fungal pathogen.
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Affiliation(s)
- Aize Pellon
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, United Kingdom
| | - Shervin Dokht Sadeghi Nasab
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, United Kingdom
| | - David L Moyes
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, United Kingdom
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Costa-de-Oliveira S, Rodrigues AG. Candida albicans Antifungal Resistance and Tolerance in Bloodstream Infections: The Triad Yeast-Host-Antifungal. Microorganisms 2020; 8:microorganisms8020154. [PMID: 31979032 PMCID: PMC7074842 DOI: 10.3390/microorganisms8020154] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 01/10/2020] [Accepted: 01/16/2020] [Indexed: 01/08/2023] Open
Abstract
Candida albicans represents the most frequent isolated yeast from bloodstream infections. Despite the remarkable progress in diagnostic and therapeutic approaches, these infections continue to be a critical challenge in intensive care units worldwide. The economic cost of bloodstream fungal infections and its associated mortality, especially in debilitated patients, remains unacceptably high. Candida albicans is a highly adaptable microorganism, being able to develop resistance following prolonged exposure to antifungals. Formation of biofilms, which diminish the accessibility of the antifungal, selection of spontaneous mutations that increase expression or decreased susceptibility of the target, altered chromosome abnormalities, overexpression of multidrug efflux pumps and the ability to escape host immune defenses are some of the factors that can contribute to antifungal tolerance and resistance. The knowledge of the antifungal resistance mechanisms can allow the design of alternative therapeutically options in order to modulate or revert the resistance. We have focused this review on the main factors that are involved in antifungal resistance and tolerance in patients with C. albicans bloodstream infections.
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Affiliation(s)
- Sofia Costa-de-Oliveira
- Division of Microbiology, Department of Pathology, Faculty of Medicine, University of Porto, Al. Hernâni Monteiro, 4200-319 Porto, Portugal;
- Center for Research in Health Technologies and Information Systems (CINTESIS), R. Dr. Plácido da Costa, 4200-450 Porto, Portugal
- Correspondence: ; Tel.: +351-220-426-870
| | - Acácio G. Rodrigues
- Division of Microbiology, Department of Pathology, Faculty of Medicine, University of Porto, Al. Hernâni Monteiro, 4200-319 Porto, Portugal;
- Center for Research in Health Technologies and Information Systems (CINTESIS), R. Dr. Plácido da Costa, 4200-450 Porto, Portugal
- Burn Unit, São João Hospital Center, Al. Hernâni Monteiro, 4200-319 Porto, Portugal
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