1
|
Kane A, Dinh H, Campbell L, Cain AK, Hibbs D, Carter D. Spectrum of activity and mechanisms of azole-bisphosphonate synergy in pathogenic Candida. Microbiol Spectr 2024; 12:e0012124. [PMID: 38695556 PMCID: PMC11237636 DOI: 10.1128/spectrum.00121-24] [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: 01/13/2024] [Accepted: 04/12/2024] [Indexed: 06/06/2024] Open
Abstract
Candidiasis places a significant burden on human health and can range from common superficial vulvovaginal and oral infections to invasive diseases with high mortality. The most common Candida species implicated in human disease is Candida albicans, but other species like Candida glabrata are emerging. The use of azole antifungals for treatment is limited by increasing rates of resistance. This study explores repositioning bisphosphonates, which are traditionally used for osteoporosis, as antifungal synergists that can improve and revitalize the use of azoles. Risedronate, alendronate, and zoledronate (ZOL) were tested against isolates from six different species of Candida, and ZOL produced moderate antifungal activity and strong synergy with azoles like fluconazole (FLC), particularly in C. glabrata. FLC:ZOL combinations had increased fungicidal and antibiofilm activity compared to either drug alone, and the combination prevented the development of antifungal resistance. Mechanistic investigations demonstrated that the synergy was mediated by the depletion of squalene, resulting in the inhibition of ergosterol biosynthesis and a compromised membrane structure. In C. glabrata, synergy compromised the function of membrane-bound multidrug transporters and caused an accumulation of reactive oxygen species, which may account for its acute sensitivity to FLC:ZOL. The efficacy of FLC:ZOL in vivo was confirmed in a Galleria mellonella infection model, where combinations improved the survival of larvae infected with C. albicans and C. glabrata to a greater extent than monotherapy with FLC or ZOL, and at reduced dosages. These findings demonstrate that bisphosphonates and azoles are a promising new combination therapy for the treatment of topical candidiasis. IMPORTANCE Candida is a common and often very serious opportunistic fungal pathogen. Invasive candidiasis is a prevalent cause of nosocomial infections with a high mortality rate, and mucocutaneous infections significantly impact the quality of life of millions of patients a year. These infections pose substantial clinical challenges, particularly as the currently available antifungal treatment options are limited in efficacy and often toxic. Azoles are a mainstay of antifungal therapy and work by targeting the biosynthesis of ergosterol. However, there are rising rates of acquired azole resistance in various Candida species, and some species are considered intrinsically resistant to most azoles. Our research demonstrates the promising therapeutic potential of synergistically enhancing azoles with non-toxic, FDA-approved bisphosphonates. Repurposing bisphosphonates as antifungal synergists can bypass much of the drug development pipeline and accelerate the translation of azole-bisphosphonate combination therapy.
Collapse
Affiliation(s)
- Aidan Kane
- School of Life and Environmental Sciences and the Sydney Institute for Infectious Diseases, The University of Sydney, Sydney, New South Wales, Australia
| | - Hue Dinh
- School of Natural Sciences, ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales, Australia
| | - Leona Campbell
- School of Life and Environmental Sciences and the Sydney Institute for Infectious Diseases, The University of Sydney, Sydney, New South Wales, Australia
| | - Amy K. Cain
- School of Natural Sciences, ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales, Australia
| | - David Hibbs
- School of Pharmacy, The University of Sydney, Sydney, New South Wales, Australia
| | - Dee Carter
- School of Life and Environmental Sciences and the Sydney Institute for Infectious Diseases, The University of Sydney, Sydney, New South Wales, Australia
| |
Collapse
|
2
|
Schrevens S, Sanglard D. A novel Candida glabrata doxycycline-inducible system for in vitro/in vivo use. FEMS Yeast Res 2022; 22:6680246. [PMID: 36047937 PMCID: PMC9508828 DOI: 10.1093/femsyr/foac046] [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] [Received: 07/04/2022] [Revised: 08/17/2022] [Accepted: 08/30/2022] [Indexed: 11/23/2022] Open
Abstract
Candida glabrata is an important pathogen causing superficial to invasive disease in human. Conditional expression systems are helpful in addressing the function of genes and especially when they can be applied to in vivo studies. Tetracycline-dependent regulation systems have been used in diverse fungi to turn-on (Tet-on) or turn-off (Tet-off) gene expression either in vitro but also in vivo in animal models. Up to now, only a Tet-off expression has been constructed for gene expression in C. glabrata. Here, we report a Tet-on gene expression system which can be used in vitro and in vivo in any C. glabrata genetic background. This system was used in a mice model of systemic infection to demonstrate that the general amino acid permease Gap1 is important for C. glabrata virulence.
Collapse
Affiliation(s)
- S Schrevens
- Institute of Microbiology, University of Lausanne and University Hospital, CH-1011 Lausanne, Switzerland
| | - D Sanglard
- Institute of Microbiology, University of Lausanne and University Hospital, CH-1011 Lausanne, Switzerland
| |
Collapse
|
3
|
Merdan O, Şişman AS, Aksoy SA, Kızıl S, Tüzemen NÜ, Yılmaz E, Ener B. Investigation of the Defective Growth Pattern and Multidrug Resistance in a Clinical Isolate of Candida glabrata Using Whole-Genome Sequencing and Computational Biology Applications. Microbiol Spectr 2022; 10:e0077622. [PMID: 35867406 PMCID: PMC9430859 DOI: 10.1128/spectrum.00776-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 06/16/2022] [Indexed: 11/20/2022] Open
Abstract
Candida glabrata is increasingly isolated from blood cultures, and multidrug-resistant isolates have important implications for therapy. This study describes a cholesterol-dependent clinical C. glabrata isolate (ML72254) that did not grow without blood (containing cholesterol) on routine mycological media and that showed azole and amphotericin B (AmB) resistance. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) and whole-genome sequencing (WGS) were used for species identification. A modified Etest method (Mueller-Hinton agar supplemented with 5% sheep blood) was used for antifungal susceptibility testing. WGS data were processed via the Galaxy platform, and the genomic variations of ML72254 were retrieved. A computational biology workflow utilizing web-based applications (PROVEAN, AlphaFold Colab, and Missense3D) was constructed to predict possible deleterious effects of these missense variations on protein functions. The predictive ability of this workflow was tested with previously reported missense variations in ergosterol synthesis genes of C. glabrata. ML72254 was identified as C. glabrata sensu stricto with MALDI-TOF, and WGS confirmed this identification. The MICs of fluconazole, voriconazole, and amphotericin B were >256, >32, and >32 μg/mL, respectively. A novel frameshift mutation in the ERG1 gene (Pro314fs) and many missense variations were detected in the ergosterol synthesis genes. None of the missense variations in the ML72254 ergosterol synthesis genes were deleterious, and the Pro314fs mutation was identified as the causative molecular change for a cholesterol-dependent and multidrug-resistant phenotype. This study verified that web-based computational biology solutions can be powerful tools for examining the possible impacts of missense mutations in C. glabrata. IMPORTANCE In this study, a cholesterol-dependent C. glabrata clinical isolate that confers azole and AmB resistance was investigated using artificial intelligence (AI) technologies and cloud computing applications. This is the first of the known cholesterol-dependent C. glabrata isolate to be found in Turkey. Cholesterol-dependent C. glabrata isolates are rarely isolated in clinical samples; they can easily be overlooked during routine laboratory procedures. Microbiologists therefore need to be alert when discrepancies occur between microscopic examination and growth on routine media. In addition, because these isolates confer antifungal resistance, patient management requires extra care.
Collapse
Affiliation(s)
- Osman Merdan
- Department of Medical Microbiology, Faculty of Medicine, Bursa Uludağ University, Bursa, Turkey
| | - Ayşe Sena Şişman
- Department of Clinical Microbiology and Infectious Diseases, Faculty of Medicine, Bursa Uludağ University, Bursa, Turkey
| | - Seçil Ak Aksoy
- İnegöl Vocational School, Bursa Uludağ University, Bursa, Turkey
| | - Samet Kızıl
- Department of Medical Microbiology, Faculty of Medicine, Bursa Uludağ University, Bursa, Turkey
| | - Nazmiye Ülkü Tüzemen
- Department of Medical Microbiology, Faculty of Medicine, Bursa Uludağ University, Bursa, Turkey
| | - Emel Yılmaz
- Department of Clinical Microbiology and Infectious Diseases, Faculty of Medicine, Bursa Uludağ University, Bursa, Turkey
| | - Beyza Ener
- Department of Medical Microbiology, Faculty of Medicine, Bursa Uludağ University, Bursa, Turkey
| |
Collapse
|
4
|
Malwal S, Shang N, Liu W, Li X, Zhang L, Chen CC, Guo RT, Oldfield E. A Structural and Bioinformatics Investigation of a Fungal Squalene Synthase and Comparisons with Other Membrane Proteins. ACS OMEGA 2022; 7:22601-22612. [PMID: 35811857 PMCID: PMC9260892 DOI: 10.1021/acsomega.2c01924] [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: 03/29/2022] [Accepted: 06/03/2022] [Indexed: 06/15/2023]
Abstract
There is interest in the development of drugs to treat fungal infections due to the increasing threat of drug resistance, and here, we report the first crystallographic structure of the catalytic domain of a fungal squalene synthase (SQS), Aspergillus flavus SQS (AfSQS), a potential drug target, together with a bioinformatics study of fungal, human, and protozoal SQSs. Our X-ray results show strong structural similarities between the catalytic domains in these proteins, but, remarkably, using bioinformatics, we find that there is also a large, highly polar helix in the fungal proteins that connects the catalytic and membrane-anchoring transmembrane domains. This polar helix is absent in squalene synthases from all other lifeforms. We show that the transmembrane domain in AfSQS and in other SQSs, stannin, and steryl sulfatase, have very similar properties (% polar residues, hydrophobicity, and hydrophobic moment) to those found in the "penultimate" C-terminal helical domain in squalene epoxidase, while the final C-terminal domain in squalene epoxidase is more polar and may be monotopic. We also propose structural models for full-length AfSQS based on the bioinformatics results as well as a deep learning program that indicate that the C-terminus region may also be membrane surface-associated. Taken together, our results are of general interest given the unique nature of the polar helical domain in fungi that may be involved in protein-protein interactions as well as being a future target for antifungals.
Collapse
Affiliation(s)
- Satish
R. Malwal
- Department
of Chemistry, University of Illinois at
Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Na Shang
- Industrial
Enzymes National Engineering Laboratory, Tianjin Institute of Industrial Biotechnology, Chinese Academy of
Sciences, Tianjin 300308, China
| | - Weidong Liu
- Industrial
Enzymes National Engineering Laboratory, Tianjin Institute of Industrial Biotechnology, Chinese Academy of
Sciences, Tianjin 300308, China
| | - Xian Li
- State
Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative
Innovation Center for Green Transformation of Bio-resources, Hubei
Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Lilan Zhang
- State
Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative
Innovation Center for Green Transformation of Bio-resources, Hubei
Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Chun-Chi Chen
- State
Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative
Innovation Center for Green Transformation of Bio-resources, Hubei
Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Rey-Ting Guo
- State
Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative
Innovation Center for Green Transformation of Bio-resources, Hubei
Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Eric Oldfield
- Department
of Chemistry, University of Illinois at
Urbana-Champaign, Urbana, Illinois 61801, United States
| |
Collapse
|
5
|
Shantal CJN, Juan CC, Lizbeth BUS, Carlos HGJ, Estela GPB. Candida glabrata is a successful pathogen: an artist manipulating the immune response. Microbiol Res 2022; 260:127038. [DOI: 10.1016/j.micres.2022.127038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 04/02/2022] [Accepted: 04/07/2022] [Indexed: 02/07/2023]
|
6
|
Abstract
Pathogenic fungi have several mechanisms of resistance to antifungal drugs, driven by the genetic plasticity and versatility of their homeostatic responses to stressful environmental cues. We critically review the molecular mechanisms of resistance and cellular adaptations of pathogenic fungi in response to antifungals and discuss the factors contributing to such resistance. We offer suggestions for the translational and clinical research agenda of this rapidly evolving and medically important field. A better understanding of antifungal resistance should assist in developing better detection tools and inform optimal strategies for preventing and treating refractory mycoses in the future.
Collapse
Affiliation(s)
- Ronen Ben-Ami
- Infectious Diseases Department, Sackler School of Medicine, Tel Aviv University, Tel Aviv Sourasky Medical Center, 6 Weizmann, Tel Aviv 64239, Israel
| | - Dimitrios P Kontoyiannis
- Infectious Diseases, University of Texas M D Anderson Cancer Center, 1515 Holcombe, Houston, TX 77030, USA.
| |
Collapse
|
7
|
Demin KA, Refeld AG, Bogdanova AA, Prazdnova EV, Popov IV, Kutsevalova OY, Ermakov AM, Bren AB, Rudoy DV, Chistyakov VA, Weeks R, Chikindas ML. Mechanisms of Candida Resistance to Antimycotics and Promising Ways to Overcome It: The Role of Probiotics. Probiotics Antimicrob Proteins 2021; 13:926-948. [PMID: 33738706 DOI: 10.1007/s12602-021-09776-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2021] [Indexed: 12/12/2022]
Abstract
Pathogenic Candida and infections caused by those species are now considered as a serious threat to public health. The treatment of candidiasis is significantly complicated by the increasing resistance of pathogenic strains to current treatments and the stagnant development of new antimycotic drugs. Many species, such as Candida auris, have a wide range of resistance mechanisms. Among the currently used synthetic and semi-synthetic antifungal drugs, the most effective are azoles, echinocandins, polyenes, nucleotide analogs, and their combinations. However, the use of probiotic microorganisms and/or the compounds they produce is quite promising, although underestimated by modern pharmacology, to control the spread of pathogenic Candida species.
Collapse
Affiliation(s)
- Konstantin A Demin
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
| | - Aleksandr G Refeld
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
| | - Anna A Bogdanova
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
| | - Evgenya V Prazdnova
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
| | - Igor V Popov
- Center for Agrobiotechnology, Don State Technical University, Rostov-on-Don, Russia
| | | | - Alexey M Ermakov
- Center for Agrobiotechnology, Don State Technical University, Rostov-on-Don, Russia
| | - Anzhelica B Bren
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia.,Center for Agrobiotechnology, Don State Technical University, Rostov-on-Don, Russia
| | - Dmitry V Rudoy
- Center for Agrobiotechnology, Don State Technical University, Rostov-on-Don, Russia
| | - Vladimir A Chistyakov
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
| | - Richard Weeks
- Health Promoting Naturals Laboratory, School of Environmental and Biological Sciences, Rutgers State University, New Brunswick, NJ, USA
| | - Michael L Chikindas
- Center for Agrobiotechnology, Don State Technical University, Rostov-on-Don, Russia. .,Health Promoting Naturals Laboratory, School of Environmental and Biological Sciences, Rutgers State University, New Brunswick, NJ, USA. .,I.M. Sechenov First Moscow State Medical University, Moscow, Russia.
| |
Collapse
|
8
|
Mamouei Z, Singh S, Lemire B, Gu Y, Alqarihi A, Nabeela S, Li D, Ibrahim A, Uppuluri P. An evolutionarily diverged mitochondrial protein controls biofilm growth and virulence in Candida albicans. PLoS Biol 2021; 19:e3000957. [PMID: 33720927 PMCID: PMC8007014 DOI: 10.1371/journal.pbio.3000957] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 03/29/2021] [Accepted: 01/29/2021] [Indexed: 11/19/2022] Open
Abstract
A forward genetic screening approach identified orf19.2500 as a gene controlling Candida albicans biofilm dispersal and biofilm detachment. Three-dimensional (3D) protein modeling and bioinformatics revealed that orf19.2500 is a conserved mitochondrial protein, structurally similar to, but functionally diverged from, the squalene/phytoene synthases family. The C. albicans orf19.2500 is distinguished by 3 evolutionarily acquired stretches of amino acid inserts, absent from all other eukaryotes except a small number of ascomycete fungi. Biochemical assays showed that orf19.2500 is required for the assembly and activity of the NADH ubiquinone oxidoreductase Complex I (CI) of the respiratory electron transport chain (ETC) and was thereby named NDU1. NDU1 is essential for respiration and growth on alternative carbon sources, important for immune evasion, required for virulence in a mouse model of hematogenously disseminated candidiasis, and for potentiating resistance to antifungal drugs. Our study is the first report on a protein that sets the Candida-like fungi phylogenetically apart from all other eukaryotes, based solely on evolutionary "gain" of new amino acid inserts that are also the functional hub of the protein.
Collapse
Affiliation(s)
- Zeinab Mamouei
- David Geffen School of Medicine, University of California (UCLA), Los Angeles, California, United States of America
| | - Shakti Singh
- Division of Infectious Disease, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, United States of America
| | - Bernard Lemire
- Department of Biochemistry, University of Alberta, Alberta, Canada
| | - Yiyou Gu
- Division of Infectious Disease, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, United States of America
| | - Abdullah Alqarihi
- Division of Infectious Disease, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, United States of America
| | - Sunna Nabeela
- Division of Infectious Disease, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, United States of America
| | - Dongmei Li
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC, United States of America
| | - Ashraf Ibrahim
- David Geffen School of Medicine, University of California (UCLA), Los Angeles, California, United States of America
- Division of Infectious Disease, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, United States of America
| | - Priya Uppuluri
- David Geffen School of Medicine, University of California (UCLA), Los Angeles, California, United States of America
- Division of Infectious Disease, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, United States of America
- * E-mail:
| |
Collapse
|
9
|
Alves R, Kastora SL, Gomes-Gonçalves A, Azevedo N, Rodrigues CF, Silva S, Demuyser L, Van Dijck P, Casal M, Brown AJP, Henriques M, Paiva S. Transcriptional responses of Candida glabrata biofilm cells to fluconazole are modulated by the carbon source. NPJ Biofilms Microbiomes 2020; 6:4. [PMID: 31993211 PMCID: PMC6978337 DOI: 10.1038/s41522-020-0114-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 12/20/2019] [Indexed: 12/21/2022] Open
Abstract
Candida glabrata is an important human fungal pathogen known to trigger serious infections in immune-compromised individuals. Its ability to form biofilms, which exhibit high tolerance to antifungal treatments, has been considered as an important virulence factor. However, the mechanisms involving antifungal resistance in biofilms and the impact of host niche environments on these processes are still poorly defined. In this study, we performed a whole-transcriptome analysis of C. glabrata biofilm cells exposed to different environmental conditions and constraints in order to identify the molecular pathways involved in fluconazole resistance and understand how acidic pH niches, associated with the presence of acetic acid, are able to modulate these responses. We show that fluconazole treatment induces gene expression reprogramming in a carbon source and pH-dependent manner. This is particularly relevant for a set of genes involved in DNA replication, ergosterol, and ubiquinone biosynthesis. We also provide additional evidence that the loss of mitochondrial function is associated with fluconazole resistance, independently of the growth condition. Lastly, we propose that C. glabrata Mge1, a cochaperone involved in iron metabolism and protein import into the mitochondria, is a key regulator of fluconazole susceptibility during carbon and pH adaptation by reducing the metabolic flux towards toxic sterol formation. These new findings suggest that different host microenvironments influence directly the physiology of C. glabrata, with implications on how this pathogen responds to antifungal treatment. Our analyses identify several pathways that can be targeted and will potentially prove to be useful for developing new antifungals to treat biofilm-based infections.
Collapse
Grants
- MR/M026663/1 Medical Research Council
- MR/N006364/1 Medical Research Council
- MR/N006364/2 Medical Research Council
- This study was supported by the Portuguese National Funding Agency for Science, Research and Technology FCT (grant PTDC/BIAMIC/5184/2014). RA received FCT PhD fellowship (PD/BD/113813/2015). The authors gratefully acknowledge Edinburgh Genomics for RNA-Seq library preparation and sequencing. The work on CBMA was supported by the strategic program UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569). The work on CEB was supported by PEst-OE/EQB/LA0023/2013, from FCT, “BioHealth - Biotechnology and Bioengineering approaches to improve health quality", Ref. NORTE-07-0124-FEDER-000027, co-funded by the Programa Operacional Regional do Norte (ON.2 – O Novo Norte), QREN, FEDER and the project “Consolidating Research Expertize and Resources on Cellular and Molecular Biotechnology at CEB/IBB”, Ref. FCOMP-01-0124-FEDER-027462. The work in Aberdeen was also supported by the European Research Council through the advanced grant “STRIFE” (C-2009-AdG-249793), by the UK Medical Research Council (MR/M026663/1) and by the Medical Research Council Center for Medical Mycology and the University of Aberdeen (MR/N006364/1). The work at KU Leuven was supported by the Federation of European Biochemical Societies (FEBS) through a short-term fellowship awarded to RA and by the Fund for Scientific Research Flanders (FWO; WO.009.16N).
- Federation of European Biochemical Societies (FEBS)
- Strategic program UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569)
- European Research Council through the advanced grant “STRIFE” (C-2009-AdG-249793), UK Medical Research Council (MR/M026663/1) and Medical Research Council Center for Medical Mycology and the University of Aberdeen (MR/N006364/1
Collapse
Affiliation(s)
- Rosana Alves
- Center of Molecular and Environmental Biology, Department of Biology, University of Minho, Braga, Portugal
| | - Stavroula L. Kastora
- Aberdeen Fungal Group, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen, UK
| | - Alexandra Gomes-Gonçalves
- Center of Molecular and Environmental Biology, Department of Biology, University of Minho, Braga, Portugal
| | - Nuno Azevedo
- LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, Center for Biological Engineering, University of Minho, Braga, Portugal
| | - Célia F. Rodrigues
- LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, Center for Biological Engineering, University of Minho, Braga, Portugal
- LEPABE, Department of Chemical Engineering, University of Porto, Porto, Portugal
| | - Sónia Silva
- LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, Center for Biological Engineering, University of Minho, Braga, Portugal
| | - Liesbeth Demuyser
- VIB-KU Leuven Center for Microbiology, Flanders, Belgium
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven, Belgium
| | - Patrick Van Dijck
- VIB-KU Leuven Center for Microbiology, Flanders, Belgium
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven, Belgium
| | - Margarida Casal
- Center of Molecular and Environmental Biology, Department of Biology, University of Minho, Braga, Portugal
| | - Alistair J. P. Brown
- Aberdeen Fungal Group, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen, UK
- MRC Center for Medical Mycology, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, UK
| | - Mariana Henriques
- LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, Center for Biological Engineering, University of Minho, Braga, Portugal
| | - Sandra Paiva
- Center of Molecular and Environmental Biology, Department of Biology, University of Minho, Braga, Portugal
| |
Collapse
|
10
|
Rizzo J, Stanchev LD, da Silva VK, Nimrichter L, Pomorski TG, Rodrigues ML. Role of lipid transporters in fungal physiology and pathogenicity. Comput Struct Biotechnol J 2019; 17:1278-1289. [PMID: 31921394 PMCID: PMC6944739 DOI: 10.1016/j.csbj.2019.09.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 08/20/2019] [Accepted: 09/02/2019] [Indexed: 02/08/2023] Open
Abstract
The fungal cell wall and membrane are the most common targets of antifungal agents, but the potential of membrane lipid organization in regulating drug-target interactions has yet to be investigated. Energy-dependent lipid transporters have been recently associated with virulence and drug resistance in many pathogenic fungi. To illustrate this view, we discuss (i) the structural and biological aspects of ATP-driven lipid transporters, comprising P-type ATPases and ATP-binding cassette transporters, (ii) the role of these transporters in fungal physiology and virulence, and (iii) the potential of lipid transporters as targets for the development of novel antifungals. These recent observations indicate that the lipid-trafficking machinery in fungi is a promising target for studies on physiology, pathogenesis and drug development.
Collapse
Affiliation(s)
- Juliana Rizzo
- Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Lyubomir Dimitrov Stanchev
- Department of Molecular Biochemistry, Ruhr University Bochum, Faculty of Chemistry and Biochemistry, 44780 Bochum, Germany
- Department of Plant Biology and Biotechnology, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C,Denmark
| | - Vanessa K.A. da Silva
- Programa de Pós-Graduação em Biologia Parasitária do Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil
| | - Leonardo Nimrichter
- Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Thomas Günther Pomorski
- Department of Molecular Biochemistry, Ruhr University Bochum, Faculty of Chemistry and Biochemistry, 44780 Bochum, Germany
- Department of Plant Biology and Biotechnology, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C,Denmark
| | - Marcio L. Rodrigues
- Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (Fiocruz), Curitiba, Brazil
| |
Collapse
|
11
|
Heterologous Expression of Full-Length Lanosterol 14α-Demethylases of Prominent Fungal Pathogens Candida albicans and Candida glabrata Provides Tools for Antifungal Discovery. Antimicrob Agents Chemother 2018; 62:AAC.01131-18. [PMID: 30126959 DOI: 10.1128/aac.01131-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 08/08/2018] [Indexed: 12/20/2022] Open
Abstract
Targeting lanosterol 14α-demethylase (LDM) with azole drugs provides prophylaxis and treatments for superficial and disseminated fungal infections, but cure rates are modest for immunocompromised patients and individuals with comorbidities. The efficacy of azole drugs has also been reduced due to the emergence of drug-resistant fungal pathogens. We have addressed these problems by expressing in Saccharomyces cerevisiae functional, hexahistidine-tagged, full-length Candida albicans LDM (CaLDM6×His) and Candida glabrata LDM (CgLDM6×His) for drug discovery purposes and determining their X-ray crystal structures. Compared with S. cerevisiae overexpressing LDM6×His (ScLDM6×His), the reduced susceptibility of CgLDM6×His to all azole drugs tested correlated with its level of overexpression. In contrast, the reduced susceptibility to short-tailed (fluconazole and voriconazole) but not medium-tailed (VT-1161) or long-tailed azoles (itraconazole and posaconazole) indicates CaLDM6×His works best when coexpressed with its cognate NADPH-cytochrome P450 reductase (CaNcp1A) rather than the host reductase (ScNcp1). Overexpression of LDM or Ncp1 modified the ergosterol content of yeast and affected growth inhibition by the polyene antibiotic amphotericin B. Affinity-purified recombinant Candida LDMs bind carbon monoxide and show tight type II binding of a range of azole drugs, including itraconazole, posaconazole, fluconazole, and voriconazole. This study provides a practical basis for the phenotype-, biochemistry-, and structure-directed discovery of novel antifungals that target LDMs of fungal pathogens.
Collapse
|
12
|
Hirai K, Inukai T, Nakayama H. Promising Therapies for Fungal Infection Based on the Study to Elucidate Mechanisms to Cope with Stress in Candida Species [Translated Article]. Med Mycol J 2017. [PMID: 28566663 DOI: 10.3314/mmj.17.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In recent years, the incidence of fungal infections has been increasing, particularly among patients with immune systems compromised by human immunodeficiency virus infection, organ transplantation, and/or chemotherapy for cancer. Current therapies for treating systemic fungal infection have limited effectiveness and have created problems of adverse reactions and drug resistance. These issues therefore motivate us to develop novel antifungals. Elucidation of stress response mechanisms and virulence factors in pathogenic fungi is required in developing an effective antifungal strategy. There are actually numerous studies concerning various stress responses in several important fungal pathogens. Among these responses, we focused on stress response for iron starvation to identify potential targets for novel antifungals because iron starvation occurs in blood, where pathogenic fungi often infect. Here we show recent progress of studies on iron homeostasis in Candida species, especially focusing on Candida glabrata, and propose novel antifungal targets.
Collapse
Affiliation(s)
- Kazuyuki Hirai
- Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science
| | - Tatsuya Inukai
- Department of Chemotherapy and Mycoses, National Institute of Infectious Diseases.,Diseases Division of Pathology, Immunology and Microbiology, Graduate School of Medicine, The University of Tokyo
| | - Hironobu Nakayama
- Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science
| |
Collapse
|
13
|
Zhou P, Fu J, Hua H, Liu X. In vitro inhibitory activities of magnolol against Candida spp. Drug Des Devel Ther 2017; 11:2653-2661. [PMID: 28919715 PMCID: PMC5593404 DOI: 10.2147/dddt.s146529] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Candida spp. cause various infections involving the skin, mucosa, deep tissues, and even life-threatening candidemia. They are regarded as an important pathogen of nosocomial bloodstream infection, with a high mortality rate. As a result of prolonged exposure to azoles, the therapeutic failure associated with azoles resistance has become a serious challenge in clinical situations. Therefore, novel, alternative antifungals are required urgently. In the present study, the CLSI M-27A broth microdilution method and the 2,3-Bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction assay were used to evaluate the antifungal effects of magnolol against various standard Candida strains in planktonic mode and biofilm formation, respectively. The antifungal activity of magnolol was demonstrated in planktonic C. albicans and non-albicans Candida species, especially fluconazole-resistant Candida krusei, with the minimum inhibitory concentrations ranging from 10 to 40 μg/mL. The BMIC90 (minimum concentration with 90% Candida biofilm inhibited) values of magnolol ranged from 20 to 160 μg/mL, whereas the BMIC90 values of fluconazole were more than 128 μg/mL. As an alternative and broad-spectrum antifungal agent, magnolol might be of benefit to the treatment of refractory Candida infection.
Collapse
Affiliation(s)
- Peiru Zhou
- Department of Oral Medicine, Peking University School and Hospital of Stomatology
| | - Jingya Fu
- Department of Stomatology, Peking University International Hospital, Beijing, People's Republic of China
| | - Hong Hua
- Department of Oral Medicine, Peking University School and Hospital of Stomatology
| | - Xiaosong Liu
- Department of Oral Medicine, Peking University School and Hospital of Stomatology
| |
Collapse
|
14
|
Joshua IM, Höfken T. From Lipid Homeostasis to Differentiation: Old and New Functions of the Zinc Cluster Proteins Ecm22, Upc2, Sut1 and Sut2. Int J Mol Sci 2017; 18:ijms18040772. [PMID: 28379181 PMCID: PMC5412356 DOI: 10.3390/ijms18040772] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 03/27/2017] [Accepted: 03/31/2017] [Indexed: 12/27/2022] Open
Abstract
Zinc cluster proteins are a large family of transcriptional regulators with a wide range of biological functions. The zinc cluster proteins Ecm22, Upc2, Sut1 and Sut2 have initially been identified as regulators of sterol import in the budding yeast Saccharomyces cerevisiae. These proteins also control adaptations to anaerobic growth, sterol biosynthesis as well as filamentation and mating. Orthologs of these zinc cluster proteins have been identified in several species of Candida. Upc2 plays a critical role in antifungal resistance in these important human fungal pathogens. Upc2 is therefore an interesting potential target for novel antifungals. In this review we discuss the functions, mode of actions and regulation of Ecm22, Upc2, Sut1 and Sut2 in budding yeast and Candida.
Collapse
Affiliation(s)
| | - Thomas Höfken
- Division of Biosciences, Brunel University London, Uxbridge UB8 3PH, UK.
| |
Collapse
|
15
|
Whaley SG, Berkow EL, Rybak JM, Nishimoto AT, Barker KS, Rogers PD. Azole Antifungal Resistance in Candida albicans and Emerging Non- albicans Candida Species. Front Microbiol 2017; 7:2173. [PMID: 28127295 PMCID: PMC5226953 DOI: 10.3389/fmicb.2016.02173] [Citation(s) in RCA: 410] [Impact Index Per Article: 58.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 12/28/2016] [Indexed: 12/15/2022] Open
Abstract
Within the limited antifungal armamentarium, the azole antifungals are the most frequent class used to treat Candida infections. Azole antifungals such as fluconazole are often preferred treatment for many Candida infections as they are inexpensive, exhibit limited toxicity, and are available for oral administration. There is, however, extensive documentation of intrinsic and developed resistance to azole antifungals among several Candida species. As the frequency of azole resistant Candida isolates in the clinical setting increases, it is essential to elucidate the mechanisms of such resistance in order to both preserve and improve upon the azole class of antifungals for the treatment of Candida infections. This review examines azole resistance in infections caused by C. albicans as well as the emerging non-albicans Candida species C. parapsilosis, C. tropicalis, C. krusei, and C. glabrata and in particular, describes the current understanding of molecular basis of azole resistance in these fungal species.
Collapse
Affiliation(s)
- Sarah G Whaley
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center Memphis, TN, USA
| | - Elizabeth L Berkow
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center Memphis, TN, USA
| | - Jeffrey M Rybak
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center Memphis, TN, USA
| | - Andrew T Nishimoto
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center Memphis, TN, USA
| | - Katherine S Barker
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center Memphis, TN, USA
| | - P David Rogers
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science CenterMemphis, TN, USA; Center for Pediatric Pharmacokinetics and Therapeutics, University of Tennessee Health Science CenterMemphis, TN, USA
| |
Collapse
|
16
|
|
17
|
Hirai K, Inukai T, Nakayama H. Promising Therapies for Fungal Infection Based on the Study to Elucidate Mechanisms to Cope with Stress in <I>Candida</I> Species. Med Mycol J 2016; 57:J163-J170. [DOI: 10.3314/mmj.16.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Kazuyuki Hirai
- Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science
| | - Tatsuya Inukai
- Department of Chemotherapy and Mycoses, National Institute of Infectious Diseases
- Diseases Division of Pathology, Immunology and Microbiology, Graduate School of Medicine, The University of Tokyo
| | - Hironobu Nakayama
- Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science
| |
Collapse
|
18
|
Bastian FB, Chibucos MC, Gaudet P, Giglio M, Holliday GL, Huang H, Lewis SE, Niknejad A, Orchard S, Poux S, Skunca N, Robinson-Rechavi M. The Confidence Information Ontology: a step towards a standard for asserting confidence in annotations. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2015; 2015:bav043. [PMID: 25957950 PMCID: PMC4425939 DOI: 10.1093/database/bav043] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 04/15/2015] [Indexed: 02/01/2023]
Abstract
Biocuration has become a cornerstone for analyses in biology, and to meet needs, the amount of annotations has considerably grown in recent years. However, the reliability of these annotations varies; it has thus become necessary to be able to assess the confidence in annotations. Although several resources already provide confidence information about the annotations that they produce, a standard way of providing such information has yet to be defined. This lack of standardization undermines the propagation of knowledge across resources, as well as the credibility of results from high-throughput analyses. Seeded at a workshop during the Biocuration 2012 conference, a working group has been created to address this problem. We present here the elements that were identified as essential for assessing confidence in annotations, as well as a draft ontology—the Confidence Information Ontology—to illustrate how the problems identified could be addressed. We hope that this effort will provide a home for discussing this major issue among the biocuration community. Tracker URL:https://github.com/BgeeDB/confidence-information-ontology Ontology URL:https://raw.githubusercontent.com/BgeeDB/confidence-information-ontology/master/src/ontology/cio-simple.obo
Collapse
Affiliation(s)
- Frederic B Bastian
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland, Department of Microbiology and Immunology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, SIB Swiss Institute of Bioinformatics, 1 Rue Michel Servet, 1211 Geneva, Switzerland, Department of Medicine and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA, School of Information, University of South Florida, Tampa, FL, 33647, USA, Genomics Division, Lawrence Berkeley National Lab, 1 Cyclotron Rd., Berkeley, 94720 CA USA, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK, Swiss-Prot Group, SIB Swiss Institute of Bioinformatics, Centre Medical Universitaire, Geneva, Switzerland, ETH Zurich, Department of Computer Science, Universitätstr. 19, 8092 Zürich, Switzerland, SIB Swiss Institute of Bioinformatics, Universitätstr. 6, 8092 Zürich, Switzerland and University College London, Gower St, London WC1E 6BT, UK Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland, Department of Microbiology and Immunology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, SIB Swiss Institute of Bioinformatics, 1 Rue Michel Servet, 1211 Geneva, Switzerland, Department of Medicine and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA, School of Information, University of South Florida, Tampa, FL, 33647, USA, Genomics Division, Lawrence Berkeley Nat
| | - Marcus C Chibucos
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland, Department of Microbiology and Immunology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, SIB Swiss Institute of Bioinformatics, 1 Rue Michel Servet, 1211 Geneva, Switzerland, Department of Medicine and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA, School of Information, University of South Florida, Tampa, FL, 33647, USA, Genomics Division, Lawrence Berkeley National Lab, 1 Cyclotron Rd., Berkeley, 94720 CA USA, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK, Swiss-Prot Group, SIB Swiss Institute of Bioinformatics, Centre Medical Universitaire, Geneva, Switzerland, ETH Zurich, Department of Computer Science, Universitätstr. 19, 8092 Zürich, Switzerland, SIB Swiss Institute of Bioinformatics, Universitätstr. 6, 8092 Zürich, Switzerland and University College London, Gower St, London WC1E 6BT, UK
| | - Pascale Gaudet
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland, Department of Microbiology and Immunology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, SIB Swiss Institute of Bioinformatics, 1 Rue Michel Servet, 1211 Geneva, Switzerland, Department of Medicine and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA, School of Information, University of South Florida, Tampa, FL, 33647, USA, Genomics Division, Lawrence Berkeley National Lab, 1 Cyclotron Rd., Berkeley, 94720 CA USA, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK, Swiss-Prot Group, SIB Swiss Institute of Bioinformatics, Centre Medical Universitaire, Geneva, Switzerland, ETH Zurich, Department of Computer Science, Universitätstr. 19, 8092 Zürich, Switzerland, SIB Swiss Institute of Bioinformatics, Universitätstr. 6, 8092 Zürich, Switzerland and University College London, Gower St, London WC1E 6BT, UK
| | - Michelle Giglio
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland, Department of Microbiology and Immunology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, SIB Swiss Institute of Bioinformatics, 1 Rue Michel Servet, 1211 Geneva, Switzerland, Department of Medicine and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA, School of Information, University of South Florida, Tampa, FL, 33647, USA, Genomics Division, Lawrence Berkeley National Lab, 1 Cyclotron Rd., Berkeley, 94720 CA USA, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK, Swiss-Prot Group, SIB Swiss Institute of Bioinformatics, Centre Medical Universitaire, Geneva, Switzerland, ETH Zurich, Department of Computer Science, Universitätstr. 19, 8092 Zürich, Switzerland, SIB Swiss Institute of Bioinformatics, Universitätstr. 6, 8092 Zürich, Switzerland and University College London, Gower St, London WC1E 6BT, UK
| | - Gemma L Holliday
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland, Department of Microbiology and Immunology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, SIB Swiss Institute of Bioinformatics, 1 Rue Michel Servet, 1211 Geneva, Switzerland, Department of Medicine and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA, School of Information, University of South Florida, Tampa, FL, 33647, USA, Genomics Division, Lawrence Berkeley National Lab, 1 Cyclotron Rd., Berkeley, 94720 CA USA, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK, Swiss-Prot Group, SIB Swiss Institute of Bioinformatics, Centre Medical Universitaire, Geneva, Switzerland, ETH Zurich, Department of Computer Science, Universitätstr. 19, 8092 Zürich, Switzerland, SIB Swiss Institute of Bioinformatics, Universitätstr. 6, 8092 Zürich, Switzerland and University College London, Gower St, London WC1E 6BT, UK
| | - Hong Huang
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland, Department of Microbiology and Immunology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, SIB Swiss Institute of Bioinformatics, 1 Rue Michel Servet, 1211 Geneva, Switzerland, Department of Medicine and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA, School of Information, University of South Florida, Tampa, FL, 33647, USA, Genomics Division, Lawrence Berkeley National Lab, 1 Cyclotron Rd., Berkeley, 94720 CA USA, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK, Swiss-Prot Group, SIB Swiss Institute of Bioinformatics, Centre Medical Universitaire, Geneva, Switzerland, ETH Zurich, Department of Computer Science, Universitätstr. 19, 8092 Zürich, Switzerland, SIB Swiss Institute of Bioinformatics, Universitätstr. 6, 8092 Zürich, Switzerland and University College London, Gower St, London WC1E 6BT, UK
| | - Suzanna E Lewis
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland, Department of Microbiology and Immunology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, SIB Swiss Institute of Bioinformatics, 1 Rue Michel Servet, 1211 Geneva, Switzerland, Department of Medicine and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA, School of Information, University of South Florida, Tampa, FL, 33647, USA, Genomics Division, Lawrence Berkeley National Lab, 1 Cyclotron Rd., Berkeley, 94720 CA USA, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK, Swiss-Prot Group, SIB Swiss Institute of Bioinformatics, Centre Medical Universitaire, Geneva, Switzerland, ETH Zurich, Department of Computer Science, Universitätstr. 19, 8092 Zürich, Switzerland, SIB Swiss Institute of Bioinformatics, Universitätstr. 6, 8092 Zürich, Switzerland and University College London, Gower St, London WC1E 6BT, UK
| | - Anne Niknejad
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland, Department of Microbiology and Immunology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, SIB Swiss Institute of Bioinformatics, 1 Rue Michel Servet, 1211 Geneva, Switzerland, Department of Medicine and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA, School of Information, University of South Florida, Tampa, FL, 33647, USA, Genomics Division, Lawrence Berkeley National Lab, 1 Cyclotron Rd., Berkeley, 94720 CA USA, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK, Swiss-Prot Group, SIB Swiss Institute of Bioinformatics, Centre Medical Universitaire, Geneva, Switzerland, ETH Zurich, Department of Computer Science, Universitätstr. 19, 8092 Zürich, Switzerland, SIB Swiss Institute of Bioinformatics, Universitätstr. 6, 8092 Zürich, Switzerland and University College London, Gower St, London WC1E 6BT, UK Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland, Department of Microbiology and Immunology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, SIB Swiss Institute of Bioinformatics, 1 Rue Michel Servet, 1211 Geneva, Switzerland, Department of Medicine and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA, School of Information, University of South Florida, Tampa, FL, 33647, USA, Genomics Division, Lawrence Berkeley Nat
| | - Sandra Orchard
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland, Department of Microbiology and Immunology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, SIB Swiss Institute of Bioinformatics, 1 Rue Michel Servet, 1211 Geneva, Switzerland, Department of Medicine and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA, School of Information, University of South Florida, Tampa, FL, 33647, USA, Genomics Division, Lawrence Berkeley National Lab, 1 Cyclotron Rd., Berkeley, 94720 CA USA, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK, Swiss-Prot Group, SIB Swiss Institute of Bioinformatics, Centre Medical Universitaire, Geneva, Switzerland, ETH Zurich, Department of Computer Science, Universitätstr. 19, 8092 Zürich, Switzerland, SIB Swiss Institute of Bioinformatics, Universitätstr. 6, 8092 Zürich, Switzerland and University College London, Gower St, London WC1E 6BT, UK
| | - Sylvain Poux
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland, Department of Microbiology and Immunology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, SIB Swiss Institute of Bioinformatics, 1 Rue Michel Servet, 1211 Geneva, Switzerland, Department of Medicine and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA, School of Information, University of South Florida, Tampa, FL, 33647, USA, Genomics Division, Lawrence Berkeley National Lab, 1 Cyclotron Rd., Berkeley, 94720 CA USA, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK, Swiss-Prot Group, SIB Swiss Institute of Bioinformatics, Centre Medical Universitaire, Geneva, Switzerland, ETH Zurich, Department of Computer Science, Universitätstr. 19, 8092 Zürich, Switzerland, SIB Swiss Institute of Bioinformatics, Universitätstr. 6, 8092 Zürich, Switzerland and University College London, Gower St, London WC1E 6BT, UK
| | - Nives Skunca
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland, Department of Microbiology and Immunology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, SIB Swiss Institute of Bioinformatics, 1 Rue Michel Servet, 1211 Geneva, Switzerland, Department of Medicine and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA, School of Information, University of South Florida, Tampa, FL, 33647, USA, Genomics Division, Lawrence Berkeley National Lab, 1 Cyclotron Rd., Berkeley, 94720 CA USA, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK, Swiss-Prot Group, SIB Swiss Institute of Bioinformatics, Centre Medical Universitaire, Geneva, Switzerland, ETH Zurich, Department of Computer Science, Universitätstr. 19, 8092 Zürich, Switzerland, SIB Swiss Institute of Bioinformatics, Universitätstr. 6, 8092 Zürich, Switzerland and University College London, Gower St, London WC1E 6BT, UK Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland, Department of Microbiology and Immunology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, SIB Swiss Institute of Bioinformatics, 1 Rue Michel Servet, 1211 Geneva, Switzerland, Department of Medicine and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA, School of Information, University of South Florida, Tampa, FL, 33647, USA, Genomics Division, Lawrence Berkeley Nat
| | - Marc Robinson-Rechavi
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland, Department of Microbiology and Immunology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, SIB Swiss Institute of Bioinformatics, 1 Rue Michel Servet, 1211 Geneva, Switzerland, Department of Medicine and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA, School of Information, University of South Florida, Tampa, FL, 33647, USA, Genomics Division, Lawrence Berkeley National Lab, 1 Cyclotron Rd., Berkeley, 94720 CA USA, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK, Swiss-Prot Group, SIB Swiss Institute of Bioinformatics, Centre Medical Universitaire, Geneva, Switzerland, ETH Zurich, Department of Computer Science, Universitätstr. 19, 8092 Zürich, Switzerland, SIB Swiss Institute of Bioinformatics, Universitätstr. 6, 8092 Zürich, Switzerland and University College London, Gower St, London WC1E 6BT, UK Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland, SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland, Department of Microbiology and Immunology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, SIB Swiss Institute of Bioinformatics, 1 Rue Michel Servet, 1211 Geneva, Switzerland, Department of Medicine and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore MD, USA, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA, School of Information, University of South Florida, Tampa, FL, 33647, USA, Genomics Division, Lawrence Berkeley Nat
| |
Collapse
|
19
|
Inukai T, Nagi M, Morita A, Tanabe K, Aoyama T, Miyazaki Y, Bard M, Nakayama H. The mannoprotein TIR3 (CAGL0C03872g) is required for sterol uptake in Candida glabrata. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:141-51. [PMID: 25463012 DOI: 10.1016/j.bbalip.2014.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 10/30/2014] [Accepted: 11/04/2014] [Indexed: 11/19/2022]
Abstract
Sterol uptake in the pathogenic fungus, Candida glabrata, occurs via the sterol transporter, CgAus1p. Azole inhibition of sterol biosynthesis can under certain circumstances be reversed by adding exogenously sterol. Here we demonstrate that the CgTIR3 (CAGL0C03872g) gene product is also required for sterol uptake, since Cgtir3Δ strains fail to take up sterol both aerobically and under hypoxic conditions. Western analysis using an HA-tagged TIR3 strain showed that CgTir3p localizes to the cell wall, and its expression is induced by serum. Semi-quantitative reverse transcriptase-PCR also showed that two transcription regulatory genes, CgUPC2A and CgUPC2B, control CgTIR3 as well as CgAUS1 gene expression. Interestingly, complementation studies using Cgtir3Δ showed that ScDAN1, a mannoprotein required for sterol uptake in Saccharomyces cerevisiae, could not complement the C. glabrata TIR3 function. Furthermore, sterol analyses, in which both the CgAUS1 and CgTIR3 genes were constitutively expressed, resulted in aerobic sterol uptake although the amount of uptake was considerably less than that of cells cultured aerobically with serum. These results suggest that additional factors other than CgAUS1 and CgTIR3 are required for sterol uptake in C. glabrata.
Collapse
Affiliation(s)
- Tatsuya Inukai
- Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Japan; Department of Chemotherapy and Mycoses, National Institute of Infectious Diseases, Japan; Division of Pathology, Immunology and Microbiology, Graduate School of Medicine, The University of Tokyo, Japan
| | - Minoru Nagi
- Department of Chemotherapy and Mycoses, National Institute of Infectious Diseases, Japan
| | - Akihiro Morita
- Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Japan
| | - Koichi Tanabe
- Department of Chemotherapy and Mycoses, National Institute of Infectious Diseases, Japan
| | - Toshihiro Aoyama
- Department of Electronic and Information Engineering, Suzuka National College of Technology, Japan
| | - Yoshitsugu Miyazaki
- Department of Chemotherapy and Mycoses, National Institute of Infectious Diseases, Japan
| | - Martin Bard
- Department of Biology, Indiana University-Purdue University Indianapolis, USA
| | - Hironobu Nakayama
- Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Japan.
| |
Collapse
|
20
|
Lee PY, Yong VC, Rosli R, Gam LH, Chong PP. Cloning, expression and purification of squalene synthase from Candida tropicalis in Pichia pastoris. Protein Expr Purif 2014; 94:15-21. [DOI: 10.1016/j.pep.2013.10.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 10/17/2013] [Accepted: 10/19/2013] [Indexed: 10/26/2022]
|
21
|
Antifungal agents commonly used in the superficial and mucosal candidiasis treatment: mode of action and resistance development. Postepy Dermatol Alergol 2013; 30:293-301. [PMID: 24353489 PMCID: PMC3858657 DOI: 10.5114/pdia.2013.38358] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Revised: 04/16/2013] [Accepted: 06/23/2013] [Indexed: 12/02/2022] Open
Abstract
Recent progress in medical sciences and therapy resulted in an increased number of immunocompromised individuals. Candida albicans is the leading opportunistic fungal pathogen causing infections in humans, ranging from superficial mucosal lesions to disseminated or bloodstream candidiasis. Superficial candidiasis not always presents a risk to the life of the infected host, however it significantly lowers the quality of life. Superficial Candida infections are difficult to treat and their frequency of occurrence is currently rising. To implement successful treatment doctors should be up to date with better understanding of C. albicans resistance mechanisms. Despite high frequency of Candida infections there is a limited number of antimycotics available for therapy. This review focuses on current understanding of the mode of action and resistance mechanisms to conventional and emerging antifungal agents for treatment of superficial and mucosal candidiasis.
Collapse
|
22
|
Systems-level antimicrobial drug and drug synergy discovery. Nat Chem Biol 2013; 9:222-31. [PMID: 23508188 DOI: 10.1038/nchembio.1205] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 02/07/2013] [Indexed: 01/01/2023]
Abstract
Here, we review the 'target-centric' genomic strategy to antimicrobial discovery and share our perspective on identification, validation and prioritization of potential antimicrobial drug targets in the context of emerging chemical biology, genomics and phenotypic screening strategies. We propose that coupling the dual processes of antimicrobial small-molecule screening and target identification in a whole-cell context is essential to empirically annotate 'druggable' targets and advance early stage antimicrobial discovery. We also advocate a systems-level approach to annotating synthetic-lethal genetic interactions comprehensively within yeast and bacteria models. The resulting genetic interaction networks provide a landscape to rationally predict and exploit drug synergy between cognate inhibitors. We posit that synergistic combination agents provide an important and largely unexploited strategy to 'repurpose' existing chemical space and simultaneously address issues of potency, spectrum, toxicity and drug resistance in early stages of antimicrobial drug discovery.
Collapse
|
23
|
Nagi M, Tanabe K, Ueno K, Nakayama H, Aoyama T, Chibana H, Yamagoe S, Umeyama T, Oura T, Ohno H, Kajiwara S, Miyazaki Y. The Candida glabrata sterol scavenging mechanism, mediated by the ATP-binding cassette transporter Aus1p, is regulated by iron limitation. Mol Microbiol 2013; 88:371-81. [PMID: 23448689 DOI: 10.1111/mmi.12189] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/19/2013] [Indexed: 11/26/2022]
Abstract
During disseminated infection by the opportunistic pathogen Candida glabrata, uptake of sterols such as serum cholesterol may play a significant role during pathogenesis. The ATP-binding cassette transporter Aus1p is thought to function as a sterol importer and in this study, we show that uptake of exogenous sterols occurred under anaerobic conditions in wild-type cells of C. glabrata but not in AUS1-deleted mutant (aus1Δ) cells. In aerobic cultures, growth inhibition by fluconazole was prevented in the presence of serum, and AUS1 expression was upregulated. Uptake of sterol by azole treated cells required the presence of serum, and sterol alone did not reverse FLC inhibition of growth. However, if iron availability in the growth medium was limited by addition of the iron chelators ferrozine or apo-transferrin, growth of wild-type cells, but not aus1Δ cells, was rescued. In a mouse model of disseminated infection, the C. glabrata aus1Δ strain caused a significantly decreased kidney fungal burden than the wild-type strain or a strain in which AUS1 was restored. We conclude that sterol uptake in C. glabrata can occur in iron poor environment of host tissues and thus may contribute to C. glabrata pathogenesis.
Collapse
Affiliation(s)
- Minoru Nagi
- Department of Chemotherapy and Mycoses, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Comparison of sterol import under aerobic and anaerobic conditions in three fungal species, Candida albicans, Candida glabrata, and Saccharomyces cerevisiae. EUKARYOTIC CELL 2013; 12:725-38. [PMID: 23475705 DOI: 10.1128/ec.00345-12] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Sterol import has been characterized under various conditions in three distinct fungal species, the model organism Saccharomyces cerevisiae and two human fungal pathogens Candida glabrata and Candida albicans, employing cholesterol, the sterol of higher eukaryotes, as well as its fungal equivalent, ergosterol. Import was confirmed by the detection of esterified cholesterol within the cells. Comparing the three fungal species, we observe sterol import under three different conditions. First, as previously well characterized, we observe sterol import under low oxygen levels in S. cerevisiae and C. glabrata, which is dependent on the transcription factor Upc2 and/or its orthologs or paralogs. Second, we observe sterol import under aerobic conditions exclusively in the two pathogenic fungi C. glabrata and C. albicans. Uptake emerges during post-exponential-growth phases, is independent of the characterized Upc2-pathway and is slower compared to the anaerobic uptake in S. cerevisiae and C. glabrata. Third, we observe under normoxic conditions in C. glabrata that Upc2-dependent sterol import can be induced in the presence of fetal bovine serum together with fluconazole. In summary, C. glabrata imports sterols both in aerobic and anaerobic conditions, and the limited aerobic uptake can be further stimulated by the presence of serum together with fluconazole. S. cerevisiae imports sterols only in anaerobic conditions, demonstrating aerobic sterol exclusion. Finally, C. albicans imports sterols exclusively aerobically in post-exponential-growth phases, independent of Upc2. For the first time, we provide direct evidence of sterol import into the human fungal pathogen C. albicans, which until now was believed to be incapable of active sterol import.
Collapse
|
25
|
Xu N, Liu L, Zou W, Liu J, Hua Q, Chen J. Reconstruction and analysis of the genome-scale metabolic network of Candida glabrata. ACTA ACUST UNITED AC 2013; 9:205-16. [DOI: 10.1039/c2mb25311a] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
26
|
Azole resistance by loss of function of the sterol Δ⁵,⁶-desaturase gene (ERG3) in Candida albicans does not necessarily decrease virulence. Antimicrob Agents Chemother 2012; 56:1960-8. [PMID: 22252807 DOI: 10.1128/aac.05720-11] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The inactivation of ERG3, a gene encoding sterol Δ⁵,⁶-desaturase (essential for ergosterol biosynthesis), is a known mechanism of in vitro resistance to azole antifungal drugs in the human pathogen Candida albicans. ERG3 inactivation typically results in loss of filamentation and attenuated virulence in animal models of disseminated candidiasis. In this work, we identified a C. albicans clinical isolate (VSY2) with high-level resistance to azole drugs in vitro and an absence of ergosterol but normal filamentation. Sequencing of ERG3 in VSY2 revealed a double base deletion leading to a premature stop codon and thus a nonfunctional enzyme. The reversion of the double base deletion in the mutant allele (erg3-1) restored ergosterol biosynthesis and full fluconazole susceptibility in VSY2, confirming that ERG3 inactivation was the mechanism of azole resistance. Additionally, the replacement of both ERG3 alleles by erg3-1 in the wild-type strain SC5314 led to the absence of ergosterol and to fluconazole resistance without affecting filamentation. In a mouse model of disseminated candidiasis, the clinical ERG3 mutant VSY2 produced kidney fungal burdens and mouse survival comparable to those obtained with the wild-type control. Interestingly, while VSY2 was resistant to fluconazole both in vitro and in vivo, the ERG3-derived mutant of SC5314 was resistant only in vitro and was less virulent than the wild type. This suggests that VSY2 compensated for the in vivo fitness defect of ERG3 inactivation by a still unknown mechanism(s). Taken together, our results provide evidence that contrary to previous reports inactivation of ERG3 does not necessarily affect filamentation and virulence.
Collapse
|
27
|
Nakayama H, Ueno K, Uno J, Nagi M, Tanabe K, Aoyama T, Chibana H, Bard M. Growth defects resulting from inhibiting ERG20 and RAM2 in Candida glabrata. FEMS Microbiol Lett 2011; 317:27-33. [PMID: 21204938 DOI: 10.1111/j.1574-6968.2010.02205.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Farnesyl pyrophosphate (FPP) is utilized for many cellular processes, including the production of dolichols, ubiquinone (CoQ), sterols, farnesylated heme A and prenylated proteins. This lipid synthesized by FPP synthetase (ERG20) becomes attached to target proteins by the prenyltransferases, CDC43/RAM2 and RAM1/RAM2 complexes after the formation of the C15 and C20 units, respectively. Defects in protein prenylation as a result of inhibiting these enzyme complexes lead to pleiotropic effects in all eukaryotes. In this study, using Candida glabrata conditional mutants, the importance of the ERG20 and RAM2 genes for growth using both in vivo and in vitro assays was assessed by placing the RAM2 and ERG20 genes under the control of a regulatable promoter. Repression of RAM2 gene expression revealed growth defects under both conditions. However, repression of ERG20 gene expression did not impair fungal growth in a mouse host, but did result in growth defects on laboratory media. Thus, FPP synthase is not required for survival in an infected mouse, but the RAM2-encoded prenyltransferase was critical for growth under both conditions. This study strongly suggests that inhibitors of prenyltransferase may be promising antifungals.
Collapse
Affiliation(s)
- Hironobu Nakayama
- Faculty of Pharmaceutical Science, Suzuka University of Medical Science, Suzuka, Mie, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Tscherner M, Schwarzmüller T, Kuchler K. Pathogenesis and Antifungal Drug Resistance of the Human Fungal Pathogen Candida glabrata. Pharmaceuticals (Basel) 2011. [PMCID: PMC4052548 DOI: 10.3390/ph4010169] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Candida glabrata is a major opportunistic human fungal pathogen causing superficial as well as systemic infections in immunocompromised individuals and several other patient cohorts. C. glabrata represents the second most prevalent cause of candidemia and a better understanding of its virulence and drug resistance mechanisms is thus of high medical relevance. In contrast to the diploid dimorphic pathogen C. albicans, whose ability to undergo filamentation is considered a major virulence trait, C. glabrata has a haploid genome and lacks the ability to switch to filamentous growth. A major impediment for the clinical therapy of C. glabrata infections is its high intrinsic resistance to several antifungal drugs, especially azoles. Further, the development of antifungal resistance, particularly during prolonged and prophylactic therapies is diminishing efficacies of therapeutic interventions. In addition, C. glabrata harbors a large repertoire of adhesins involved in the adherence to host epithelia. Interestingly, genome plasticity, phenotypic switching or the remarkable ability to persist and survive inside host immune cells further contribute to the pathogenicity of C. glabrata. In this comprehensive review, we want to emphasize and discuss the mechanisms underlying virulence and drug resistance of C. glabrata, and discuss its ability to escape from the host immune surveillance or persist inside host cells.
Collapse
Affiliation(s)
| | | | - Karl Kuchler
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +43-1-4277-61807; Fax: +43-1-4277-9618
| |
Collapse
|
29
|
Pathway analysis of Candida albicans survival and virulence determinants in a murine infection model. Proc Natl Acad Sci U S A 2010; 107:22044-9. [PMID: 21135205 DOI: 10.1073/pnas.1009845107] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
One potentially rich source of possible targets for antifungal therapy are those Candida albicans genes deemed essential for growth under the standard culture (i.e., in vitro) conditions; however, these genes are largely unexplored as drug targets because essential genes are not experimentally amenable to conventional gene deletion and virulence studies. Using tetracycline-regulatable promoter-based conditional mutants, we investigated a murine model of candidiasis in which repressing essential genes in the host was achieved. By adding doxycycline to the drinking water starting 3 days prior to (dox - 3D) or 2 days post (dox + 2D) infection, the phenotypic consequences of temporal gene inactivation were assessed by monitoring animal survival and fungal burden in prophylaxis and acute infection settings. Of 177 selected conditional shut-off strains tested, the virulence of 102 was blocked under both repressing conditions, suggesting that the corresponding genes are essential for growth and survival in a murine host across early and established infection periods. Among these genes were those previously identified as antifungal drug targets (i.e., FKS1, ERG1, and ERG11), verifying that this methodology can be used to validate potential new targets. We also identify genes either conditionally essential or dispensable for in vitro growth but required for survival and virulence, including those in late stage ergosterol synthesis, or early steps in fatty acid or riboflavin biosynthesis. This study evaluates the role of essential genes with respect to pathogen virulence in a large-scale, systems biology context, and provides a general method for gene target validation and for uncovering unexpected antimicrobial targets.
Collapse
|
30
|
Niimi M. Characterization of the Multi-drug Efflux Systems of Pathogenic Fungi Using Functional Hyperexpression in Saccharomyces cerevisiae. ACTA ACUST UNITED AC 2010; 51:79-86. [DOI: 10.3314/jjmm.51.79] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
31
|
Miyakawa Y, Hara T, Iimura Y. Establishment of a screening system for essential genes from the pathogenic yeastCandida glabrata: identification of a putativeTEM1homologue. Lett Appl Microbiol 2009; 49:317-23. [DOI: 10.1111/j.1472-765x.2009.02661.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
32
|
Cannon RD, Lamping E, Holmes AR, Niimi K, Baret PV, Keniya MV, Tanabe K, Niimi M, Goffeau A, Monk BC. Efflux-mediated antifungal drug resistance. Clin Microbiol Rev 2009; 22:291-321, Table of Contents. [PMID: 19366916 PMCID: PMC2668233 DOI: 10.1128/cmr.00051-08] [Citation(s) in RCA: 385] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fungi cause serious infections in the immunocompromised and debilitated, and the incidence of invasive mycoses has increased significantly over the last 3 decades. Slow diagnosis and the relatively few classes of antifungal drugs result in high attributable mortality for systemic fungal infections. Azole antifungals are commonly used for fungal infections, but azole resistance can be a problem for some patient groups. High-level, clinically significant azole resistance usually involves overexpression of plasma membrane efflux pumps belonging to the ATP-binding cassette (ABC) or the major facilitator superfamily class of transporters. The heterologous expression of efflux pumps in model systems, such Saccharomyces cerevisiae, has enabled the functional analysis of efflux pumps from a variety of fungi. Phylogenetic analysis of the ABC pleiotropic drug resistance family has provided a new view of the evolution of this important class of efflux pumps. There are several ways in which the clinical significance of efflux-mediated antifungal drug resistance can be mitigated. Alternative antifungal drugs, such as the echinocandins, that are not efflux pump substrates provide one option. Potential therapeutic approaches that could overcome azole resistance include targeting efflux pump transcriptional regulators and fungal stress response pathways, blockade of energy supply, and direct inhibition of efflux pumps.
Collapse
Affiliation(s)
- Richard D Cannon
- Department of Oral Sciences, School of Dentistry, University of Otago, P.O. Box 647, Dunedin 9054, New Zealand.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Hu W, Sillaots S, Lemieux S, Davison J, Kauffman S, Breton A, Linteau A, Xin C, Bowman J, Becker J, Jiang B, Roemer T. Essential gene identification and drug target prioritization in Aspergillus fumigatus. PLoS Pathog 2007; 3:e24. [PMID: 17352532 PMCID: PMC1817658 DOI: 10.1371/journal.ppat.0030024] [Citation(s) in RCA: 197] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2006] [Accepted: 01/08/2007] [Indexed: 01/16/2023] Open
Abstract
Aspergillus fumigatus is the most prevalent airborne filamentous fungal pathogen in humans, causing severe and often fatal invasive infections in immunocompromised patients. Currently available antifungal drugs to treat invasive aspergillosis have limited modes of action, and few are safe and effective. To identify and prioritize antifungal drug targets, we have developed a conditional promoter replacement (CPR) strategy using the nitrogen-regulated A. fumigatus NiiA promoter (pNiiA). The gene essentiality for 35 A. fumigatus genes was directly demonstrated by this pNiiA-CPR strategy from a set of 54 genes representing broad biological functions whose orthologs are confirmed to be essential for growth in Candida albicans and Saccharomyces cerevisiae. Extending this approach, we show that the ERG11 gene family (ERG11A and ERG11B) is essential in A. fumigatus despite neither member being essential individually. In addition, we demonstrate the pNiiA-CPR strategy is suitable for in vivo phenotypic analyses, as a number of conditional mutants, including an ERG11 double mutant (erg11BΔ, pNiiA-ERG11A), failed to establish a terminal infection in an immunocompromised mouse model of systemic aspergillosis. Collectively, the pNiiA-CPR strategy enables a rapid and reliable means to directly identify, phenotypically characterize, and facilitate target-based whole cell assays to screen A. fumigatus essential genes for cognate antifungal inhibitors. Aspergillus fumigatus is an opportunistic filamentous fungal pathogen of emerging clinical significance. Although virulence factors are seen as potential drug targets, neither genetic analyses nor genomic comparisons have identified genuine virulence factors in A. fumigatus. Essential genes required for fungal growth and viability also serve as potential drug targets, yet few have been described in this pathogen. To begin to catalog essential genes in A. fumigatus, we devised a genetic strategy for creating conditional mutants by promoter replacement of target genes using a nitrogen-regulated promoter. Applying this genetic approach to A. fumigatus genes orthologous to known essential genes of the nonpathogenic yeast, Saccharomyces cerevisiae and Candida albicans, we demonstrate a robust enrichment for identifying essential genes conserved within this pathogen. We show that A. fumigatus conditional mutants can be evaluated according to their terminal phenotypes (e.g., conidial germination, growth, morphology, and cidal versus static consequences) and pathogenesis in a murine model of systemic aspergillosis to prioritize essential genes as novel drug targets suitable for developing broad-spectrum antifungal agents.
Collapse
MESH Headings
- Animals
- Antifungal Agents/therapeutic use
- Aspergillosis/microbiology
- Aspergillus fumigatus/genetics
- Aspergillus fumigatus/growth & development
- Aspergillus fumigatus/pathogenicity
- Cytochrome P-450 Enzyme System/genetics
- Cytochrome P-450 Enzyme System/metabolism
- DNA, Fungal/chemistry
- DNA, Fungal/genetics
- DNA, Fungal/isolation & purification
- Disease Models, Animal
- Drug Delivery Systems
- Gene Expression Regulation, Fungal
- Genes, Essential
- Genes, Fungal
- Male
- Mice
- Mice, Nude
- Molecular Sequence Data
- Nitrate Reductases/genetics
- Oxidoreductases/genetics
- Oxidoreductases/metabolism
- Phenotype
- Promoter Regions, Genetic
- RNA, Messenger/analysis
- Recombination, Genetic
- Sterol 14-Demethylase
- Transcription, Genetic
- Virulence/genetics
- Virulence/physiology
Collapse
Affiliation(s)
- Wenqi Hu
- Merck Frosst Center of Fungal Genetics, Montreal, Quebec, Canada
| | - Susan Sillaots
- Merck Frosst Center of Fungal Genetics, Montreal, Quebec, Canada
| | | | - John Davison
- Merck Frosst Center of Fungal Genetics, Montreal, Quebec, Canada
| | - Sarah Kauffman
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Anouk Breton
- Merck Frosst Center of Fungal Genetics, Montreal, Quebec, Canada
| | - Annie Linteau
- Merck Frosst Center of Fungal Genetics, Montreal, Quebec, Canada
| | - Chunlin Xin
- Merck Frosst Center of Fungal Genetics, Montreal, Quebec, Canada
| | - Joel Bowman
- Infectious Diseases, Merck Research Laboratories, Rahway, New Jersey, United States of America
| | - Jeff Becker
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Bo Jiang
- Merck Frosst Center of Fungal Genetics, Montreal, Quebec, Canada
| | - Terry Roemer
- Merck Frosst Center of Fungal Genetics, Montreal, Quebec, Canada
- * To whom correspondence should be addressed. E-mail:
| |
Collapse
|
34
|
Abstract
The yeasts, being favorite eukaryotic microorganisms used in food industry and biotechnologies for production of biomass and various substances, are also used as model organisms in genetic manipulation, molecular and biological research. In this respect, Saccharomyces cerevisiae is the best-known species but current situation in medicine and industry requires the use of other species. Here we summarize the basic taxonomic, morphological, physiological, genetic, etc. information about the pathogenic yeast Candida glabrata that is evolutionarily very closely related to baker's yeast.
Collapse
Affiliation(s)
- A Bialková
- Department of Microbiology and Virology, Faculty of Science, Comenius University, Bratislava, Slovakia
| | | |
Collapse
|
35
|
Tafforeau L, Le Blastier S, Bamps S, Dewez M, Vandenhaute J, Hermand D. Repression of ergosterol level during oxidative stress by fission yeast F-box protein Pof14 independently of SCF. EMBO J 2006; 25:4547-56. [PMID: 17016471 PMCID: PMC1589992 DOI: 10.1038/sj.emboj.7601329] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2006] [Accepted: 08/14/2006] [Indexed: 11/09/2022] Open
Abstract
We describe a new member of the F-box family, Pof14, which forms a canonical, F-box dependent SCF (Skp1, Cullin, F-box protein) ubiquitin ligase complex. The Pof14 protein has intrinsic instability that is abolished by inactivation of its Skp1 interaction motif (the F-box), Skp1 or the proteasome, indicating that Pof14 stability is controlled by an autocatalytic mechanism. Pof14 interacts with the squalene synthase Erg9, a key enzyme in ergosterol metabolism, in a membrane-bound complex that does not contain the core SCF components. pof14 transcription is induced by hydrogen peroxide and requires the Pap1 transcription factor and the Sty1 MAP kinase. Pof14 binds to and decreases Erg9 activity in vitro and a pof14 deletion strain quickly loses viability in the presence of hydrogen peroxide due to its inability to repress ergosterol synthesis. A pof14 mutant lacking the F-box and an skp1-3 ts mutant behave as wild type in the presence of oxidant showing that Pof14 function is independent of SCF. This indicates that modulation of ergosterol level plays a key role in adaptation to oxidative stress.
Collapse
Affiliation(s)
- Lionel Tafforeau
- Laboratoire de Génétique Moléculaire (GEMO), Unité de Recherche en Biologie Moléculaire (URBM), Facultés Universitaires Notre-Dame de la Paix, Namur, Belgium
| | - Sophie Le Blastier
- Laboratoire de Génétique Moléculaire (GEMO), Unité de Recherche en Biologie Moléculaire (URBM), Facultés Universitaires Notre-Dame de la Paix, Namur, Belgium
| | - Sophie Bamps
- Laboratoire de Génétique Moléculaire (GEMO), Unité de Recherche en Biologie Moléculaire (URBM), Facultés Universitaires Notre-Dame de la Paix, Namur, Belgium
| | - Monique Dewez
- Laboratoire de Génétique Moléculaire (GEMO), Unité de Recherche en Biologie Moléculaire (URBM), Facultés Universitaires Notre-Dame de la Paix, Namur, Belgium
| | - Jean Vandenhaute
- Laboratoire de Génétique Moléculaire (GEMO), Unité de Recherche en Biologie Moléculaire (URBM), Facultés Universitaires Notre-Dame de la Paix, Namur, Belgium
| | - Damien Hermand
- Laboratoire de Génétique Moléculaire (GEMO), Unité de Recherche en Biologie Moléculaire (URBM), Facultés Universitaires Notre-Dame de la Paix, Namur, Belgium
- Corresponding author. Laboratoire de Genetique Moleculaire, University of Namur, Facultes Universitaires Notre Dame de la Paix, 61 Rue de Bruxelles, B-5000 Namur, Belgium. Tel.: +32 81 724241; Fax: +32 81 724297; E-mail:
| |
Collapse
|
36
|
Bard M, Sturm AM, Pierson CA, Brown S, Rogers KM, Nabinger S, Eckstein J, Barbuch R, Lees ND, Howell SA, Hazen KC. Sterol uptake in Candida glabrata: rescue of sterol auxotrophic strains. Diagn Microbiol Infect Dis 2006; 52:285-93. [PMID: 15893902 DOI: 10.1016/j.diagmicrobio.2005.03.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2005] [Accepted: 03/01/2005] [Indexed: 11/23/2022]
Abstract
Candida glabrata is emerging as a more common and important human pathogen. It is less susceptible to azole antifungals than Candida albicans, thus, posing some unique treatment challenges. Previously undetected C. glabrata isolates were identified from clinical specimens by adding bile to the growth medium. Cholesterol was found to be the responsible ingredient in bile. Six bile-dependent isolates were characterized and were found to exhibit wild-type equivalent growth when provided human or bovine serum or free cholesterol. Sterol profiles of the 6 isolates and a C. glabrata matching wild-type strain not requiring cholesterol indicated that 2 were defective in squalene epoxidase (encoded by the ERG1 gene) activity, 3 were defective in lanosterol synthase (encoded by the ERG7 gene) activity, and the sixth was defective in heme biosynthesis. All 7 isolates produced profiles that contained cholesterol transported from the media. Because Saccharomyces cerevisiae mutants unable to synthesize heme will take up exogenous sterol under aerobic conditions, hem1 nulls of C. glabrata and C. albicans were generated and tested for growth on ergosterol media. Only the C. glabrata hem1 was able to grow indicating significant differences in exogenous sterol uptake between the 2 organisms. The ability of C. glabrata to replace ergosterol with host sterol may be responsible for its elevated azole resistance.
Collapse
Affiliation(s)
- Martin Bard
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Blankenship JR, Heitman J. Calcineurin is required for Candida albicans to survive calcium stress in serum. Infect Immun 2005; 73:5767-74. [PMID: 16113294 PMCID: PMC1231066 DOI: 10.1128/iai.73.9.5767-5774.2005] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Revised: 03/07/2005] [Accepted: 04/27/2005] [Indexed: 11/20/2022] Open
Abstract
The calcium-activated protein phosphatase calcineurin plays a critical role in the virulence of Candida albicans. Previous studies demonstrated that calcineurin is not required for the yeast-hypha dimorphic transition, host cell adherence, or host cell injury, which are all established virulence attributes of this organism. Calcineurin is, however, essential for survival in serum and disseminated infection. Here we identify the component of serum that is toxic to calcineurin mutant cells. Proteins, peptides, lipids, and other hydrophobic components were all excluded as essential toxic elements. Upon testing of small molecules present in serum, we discovered that calcineurin protects cells from stress caused by the endogenous levels of calcium ions present in serum. These studies illustrate how calcineurin functions in a calcium homeostatic pathway that enables a common human commensal to survive passage through the hostile environment of the bloodstream to establish deep-seated infections and cause disease.
Collapse
Affiliation(s)
- Jill R Blankenship
- Department of Molecular Genetics and Microbiology, 322 CARL Building, Box 3546, Duke University Medical Center, Research Drive, Durham, NC 27710, USA
| | | |
Collapse
|
38
|
Tsai HF, Bard M, Izumikawa K, Krol AA, Sturm AM, Culbertson NT, Pierson CA, Bennett JE. Candida glabrata erg1 mutant with increased sensitivity to azoles and to low oxygen tension. Antimicrob Agents Chemother 2004; 48:2483-9. [PMID: 15215098 PMCID: PMC434157 DOI: 10.1128/aac.48.7.2483-2489.2004] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A Candida glabrata erg1 (Cgerg1) mutant, CgTn201S, was identified by transposon mutagenesis and by increased fluconazole susceptibility. CgERG1 encodes a 489-amino-acid protein which, on the basis of its homology with Saccharomyces cerevisiae ERG1, is a squalene epoxidase essential for ergosterol synthesis. Interruption following codon 475 of CgErg1p decreased the ergosterol content by 50%; caused accumulation of the squalene precursor; increased the levels of susceptibility to fluconazole, itraconazole, and terbinafine; increased the level of resistance to amphotericin B; increased the levels of rhodamine 6G and [(3)H]-fluconazole uptake; reduced the level of growth; and blocked growth under conditions of low oxygen tension. In addition, CgTn201S efficiently took up exogenous cholesterol from cholesterol-containing serum. Cholesterol constituted 34% of the extractable sterols in CgTn201S when it was grown aerobically on serum-containing medium. Under the same conditions, C. albicans contained only 0.1 to 1.2% cholesterol. Exogenous sterols also restored growth under conditions of low oxygen tension. Finally, complementation of the Cgerg1 mutation restored the levels of [(3)H]fluconazole uptake and drug susceptibility to wild-type levels.
Collapse
Affiliation(s)
- Huei-Fung Tsai
- Clinical Mycology Section, Laboratory of Clinical Investigation, National Institute of Allergy and Infectious Diseases, Clinical Center NIH, Bethesda, MD 20892, USA
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Berens C, Hillen W. Gene regulation by tetracyclines. Constraints of resistance regulation in bacteria shape TetR for application in eukaryotes. EUROPEAN JOURNAL OF BIOCHEMISTRY 2003; 270:3109-21. [PMID: 12869186 DOI: 10.1046/j.1432-1033.2003.03694.x] [Citation(s) in RCA: 184] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The Tet repressor protein (TetR) regulates transcription of a family of tetracycline (tc) resistance determinants in Gram-negative bacteria. The resistance protein TetA, a membrane-spanning H+-[tc.M]+ antiporter, must be sensitively regulated because its expression is harmful in the absence of tc, yet it has to be expressed before the drugs' concentration reaches cytoplasmic levels inhibitory for protein synthesis. Consequently, TetR shows highly specific tetO binding to reduce basal expression and high affinity to tc to ensure sensitive induction. Tc can cross biological membranes by diffusion enabling this inducer to penetrate the majority of cells. These regulatory and pharmacological properties are the basis for application of TetR to selectively control the expression of single genes in lower and higher eukaryotes. TetR can be used for that purpose in some organisms without further modifications. In mammals and in a large variety of other organisms, however, eukaryotic transcriptional activator or repressor domains are fused to TetR to turn it into an efficient regulator. Mechanistic understanding and the ability to engineer and screen for mutants with specific properties allow tailoring of the DNA recognition specificity, the response to inducer tc and the dimerization specificity of TetR-based eukaryotic regulators. This review provides an overview of the TetR properties as they evolved in bacteria, the functional modifications necessary to transform it into a convenient, specific and efficient regulator for use in eukaryotes and how the interplay between structure--function studies in bacteria and specific requirements of particular applications in eukaryotes have made it a versatile and highly adaptable regulatory system.
Collapse
Affiliation(s)
- Christian Berens
- Lehrstuhl für Mikrobiologie, Institut für Mikrobiologie, Biochemie und Genetik, Friedrich-Alexander Universität Erlangen-Nürnberg, Germany
| | | |
Collapse
|
40
|
Morales IJ, Vohra PK, Puri V, Kottom TJ, Limper AH, Thomas CF. Characterization of a lanosterol 14 alpha-demethylase from Pneumocystis carinii. Am J Respir Cell Mol Biol 2003; 29:232-8. [PMID: 12606318 DOI: 10.1165/rcmb.2003-0012oc] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Pneumocystis carinii (PC) causes severe pneumonia in immunocompromised patients. PC is intrinsically resistant to treatment with azole antifungal medications. The enzyme lanosterol 14 alpha-demethylase (Erg11) is the target for azole antifungals. We cloned PCERG11 and compared its sequence to Erg11 proteins present in azole-resistant organisms, and performed chromosomal and Northern blot analysis for PCERG11. Of 13 potential sites which could confer resistance to azoles, two were identical to azole-resistant Candida. By site-directed mutagenesis we changed these two sites in PCERG11 to those present in azole-sensitive Candida to generate PCERG11-SDM (E113D, T125K). We tested the susceptibility of ERG11 deletion strains of Saccharomyces cerevisiae (SC) expressing PCERG11, PCERG11-SDM, and wild-type SCERG11 to three azole antifungals: fluconazole, itraconazole, and voriconazole. PCERG11 required a 2.2-fold higher dose of voriconazole and 3.5-fold higher dose of fluconazole than SCERG11 for a 50% reduction in growth. No difference was observed in the sensitivity to itraconazole. PCERG11-SDM has increased sensitivity to fluconazole and voriconazole, but not itraconazole. We believe that the molecular structure of the lanosterol 14 alpha-demethylase encoded by PCERG11 confers inherent resistance to azole antifungals and plays an integral part in the overall resistance of this PC to azole therapy.
Collapse
Affiliation(s)
- Ian J Morales
- Thoracic Diseases Research Unit, Division of Pulmonary, Critical Care and Internal Medicine, Department of Medicine, Mayo Clinic and Foundation, Rochester, MN 55905, USA
| | | | | | | | | | | |
Collapse
|
41
|
Sanglard D, Ischer F, Parkinson T, Falconer D, Bille J. Candida albicans mutations in the ergosterol biosynthetic pathway and resistance to several antifungal agents. Antimicrob Agents Chemother 2003; 47:2404-12. [PMID: 12878497 PMCID: PMC166068 DOI: 10.1128/aac.47.8.2404-2412.2003] [Citation(s) in RCA: 271] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The role of sterol mutations in the resistance of Candida albicans to antifungal agents has not been thoroughly investigated. Previous work reported that clinical C. albicans strains resistant to both azole antifungals and amphotericin B were defective in ERG3, a gene encoding sterol Delta(5,6)-desaturase. It is also believed that a deletion of the lanosterol 14alpha-demethylase gene, ERG11, is possible only under aerobic conditions when ERG3 is not functional. We tested these hypotheses by creating mutants by targeted deletion of the ERG3 and ERG11 genes and subjecting those mutants to antifungal susceptibility testing and sterol analysis. The homozygous erg3/erg3 mutant created, DSY1751, was resistant to azole derivatives, as expected. This mutant was, however, slightly more susceptible to amphotericin B than the parent wild type. It was possible to generate erg11/erg11 mutants in the DSY1751 background but also, surprisingly, in the background of a wild-type isolate with functional ERG3 alleles under aerobic conditions. This mutant (DSY1769) was obtained by exposure of an ERG11/erg11 heterozygous strain in a medium containing 10 micro g of amphotericin B per ml. Amphotericin B-resistant strains were obtained only from ERG11/erg11 heterozygotes at a frequency of approximately 5 x 10(-5) to 7 x 10(-5), which was consistent with mitotic recombination between the first disrupted erg11 allele and the other remaining functional ERG11 allele. DSY1769 was also resistant to azole derivatives. The main sterol fraction in DSY1769 contained lanosterol and eburicol. These studies showed that erg11/erg11 mutants of a C. albicans strain harboring a defective erg11 allele can be obtained in vitro in the presence of amphotericin B. Amphotericin B-resistant strains could therefore be selected by similar mechanisms during antifungal therapy.
Collapse
|
42
|
Nakayama H, Nakayama N, Arisawa M, Aoki Y. In vitro and in vivo effects of 14alpha-demethylase (ERG11) depletion in Candida glabrata. Antimicrob Agents Chemother 2001; 45:3037-45. [PMID: 11600353 PMCID: PMC90779 DOI: 10.1128/aac.45.11.3037-3045.2001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2000] [Accepted: 08/14/2001] [Indexed: 11/20/2022] Open
Abstract
Sterol 14alpha-demethylase (ERG11) is the target enzyme of azole antifungals that are widely used for the treatment of fungal infections. Candida glabrata is known to be less susceptible to fluconazole than most Candida albicans strains, and the incidence of C. glabrata infection has been increasing mostly in conjunction with the use of azole antifungals. Recently, it has been reported that C. glabrata can rescue the defect of ergosterol biosynthesis by incorporating cholesterol from serum. To explore the effect of inactivating Erg11p in C. glabrata, we generated mutant strains in which the ERG11 gene was placed under the control of tetracycline-regulatable promoters. In these mutants, expression of the ERG11 gene can be repressed by doxycycline (DOX). All mutants showed a growth defect in the presence of DOX. The numbers of CFU of the mutants were lowered by only 1/10 with DOX treatment. In these mutants, accumulation of 4,14-dimethylzymosterol, which differs from an accumulated abnormal sterol detected in C. albicans and Saccharomyces cerevisiae treated with fluconazole, was observed by DOX treatment. Although such phenotypes were also observed in serum-containing media by DOX treatment, they were alleviated. Furthermore, the mutant could grow in DOX-treated mice without a severe reduction in the number of cells. Thus, depleting the expression of the ERG11 gene lowered the number of CFU by only 1/10 due to the accumulation of 4,14-demethylzymosterol in vitro, and it did not result in the defective growth of fungal cells in mice. These results suggested that Erg11p is not an ideal target molecule of antifungals for C. glabrata.
Collapse
Affiliation(s)
- H Nakayama
- Department of Mycology, Nippon Roche K. K. Research Center, Kamakura, Kanagawa 247-8530, Japan.
| | | | | | | |
Collapse
|
43
|
|