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Liu F, Zeng M, Zhou X, Huang F, Song Z. Aspergillus fumigatus escape mechanisms from its harsh survival environments. Appl Microbiol Biotechnol 2024; 108:53. [PMID: 38175242 DOI: 10.1007/s00253-023-12952-z] [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: 08/15/2023] [Revised: 10/09/2023] [Accepted: 10/19/2023] [Indexed: 01/05/2024]
Abstract
Aspergillus fumigatus is a ubiquitous pathogenic mold and causes several diseases, including mycotoxicosis, allergic reactions, and systemic diseases (invasive aspergillosis), with high mortality rates. In its ecological niche, the fungus has evolved and mastered many reply strategies to resist and survive against negative threats, including harsh environmental stress and deficiency of essential nutrients from natural environments, immunity responses and drug treatments in host, and competition from symbiotic microorganisms. Hence, treating A. fumigatus infection is a growing challenge. In this review, we summarized A. fumigatus reply strategies and escape mechanisms and clarified the main competitive or symbiotic relationships between A. fumigatus, viruses, bacteria, or fungi in host microecology. Additionally, we discussed the contemporary drug repertoire used to treat A. fumigatus and the latest evidence of potential resistance mechanisms. This review provides valuable knowledge which will stimulate further investigations and clinical applications for treating and preventing A. fumigatus infections. KEY POINTS: • Harsh living environment was a great challenge for A. fumigatus survival. • A. fumigatus has evolved multiple strategies to escape host immune responses. • A. fumigatus withstands antifungal drugs via intrinsic escape mechanisms.
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Affiliation(s)
- Fangyan Liu
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, 646000, People's Republic of China
| | - Meng Zeng
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, 646000, People's Republic of China
- Department of Clinical Laboratory, Yongchuan Hospital of Chongqing Medical University, Chongqing, 402160, People's Republic of China
| | - Xue Zhou
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, 646000, People's Republic of China
| | - Fujiao Huang
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, 646000, People's Republic of China
| | - Zhangyong Song
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, 646000, People's Republic of China.
- Molecular Biotechnology Platform, Public Center of Experimental Technology, Southwest Medical University, Luzhou, 646000, People's Republic of China.
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2
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Garstka K, Potoczniak G, Kozłowski H, Rowińska-Żyrek M. Aspergillus fumigatus ZrfC Zn(II) transporter scavengers zincophore-bound Zn(II). Dalton Trans 2024; 53:2848-2858. [PMID: 38231010 DOI: 10.1039/d3dt04083f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
Aspergillus fumigatus is an opportunistic pathogen that is able to invade and grow in the lungs of immunosuppressed patients and cause invasive pulmonary aspergillosis. The concentration of free Zn(II) in living tissues is much lower than that required for optimal fungal growth; thus, to obtain Zn(II) from the host, Aspergillus fumigatus uses highly specified Zn(II) transporters: ZrfA, ZrfB and ZrfC. The ZrfC transporter plays the main role in Zn(II) acquisition from the host in neutral and mildly alkaline environment via interacting with the secreted Aspf2 zincophore. Understanding the Aspf2-ZrfC interactions is therefore necessary for explaining the process of Zn(II) acquisition by Aspergillus fumigatus, and identifying Zn(II) binding sites in its transporter and describing the thermodynamics of such binding are the fundamental steps to achieve this goal. We focus on two probable ZrfC Zn(II) binding sites and show that the Ac-MNCHFHAGVEHCIGAGESESGSSQ-NH2 region binds Zn(II) with higher affinity than the Ac-TGCHSHGS-NH2 one and that this binding is much stronger than the binding of Zn(II) to the Aspf2 zincophore, allowing efficient Zn(II) transport from the Aspf2 zincophore to the ZrfC transporter. The same ZrfC fragments also able to bind Ni(II), another metal ion essential for fungi that could also compete with Zn(II) binding, with comparable affinity.
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Affiliation(s)
- Kinga Garstka
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland.
| | - Gabriela Potoczniak
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland.
| | - Henryk Kozłowski
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland.
- Institute of Health Sciences, University of Opole, Katowicka 68 St., 45-060 Opole, Poland
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3
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Nji QN, Babalola OO, Mwanza M. Soil Aspergillus Species, Pathogenicity and Control Perspectives. J Fungi (Basel) 2023; 9:766. [PMID: 37504754 PMCID: PMC10381279 DOI: 10.3390/jof9070766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 07/05/2023] [Accepted: 07/18/2023] [Indexed: 07/29/2023] Open
Abstract
Five Aspergillus sections have members that are established agricultural pests and producers of different metabolites, threatening global food safety. Most of these pathogenic Aspergillus species have been isolated from almost all major biomes. The soil remains the primary habitat for most of these cryptic fungi. This review explored some of the ecological attributes that have contributed immensely to the success of the pathogenicity of some members of the genus Aspergillus over time. Hence, the virulence factors of the genus Aspergillus, their ecology and others were reviewed. Furthermore, some biological control techniques were recommended. Pathogenic effects of Aspergillus species are entirely accidental; therefore, the virulence evolution prediction model in such species becomes a challenge, unlike their obligate parasite counterparts. In all, differences in virulence among organisms involved both conserved and species-specific genetic factors. If the impacts of climate change continue, new cryptic Aspergillus species will emerge and mycotoxin contamination risks will increase in all ecosystems, as these species can metabolically adjust to nutritional and biophysical challenges. As most of their gene clusters are silent, fungi continue to be a source of underexplored bioactive compounds. The World Soil Charter recognizes the relevance of soil biodiversity in supporting healthy soil functions. The question of how a balance may be struck between supporting healthy soil biodiversity and the control of toxic fungi species in the field to ensure food security is therefore pertinent. Numerous advanced strategies and biocontrol methods so far remain the most environmentally sustainable solution to the control of toxigenic fungi in the field.
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Affiliation(s)
- Queenta Ngum Nji
- Food Security and Safety Focus Area, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho 2735, South Africa
| | - Olubukola Oluranti Babalola
- Food Security and Safety Focus Area, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho 2735, South Africa
| | - Mulunda Mwanza
- Food Security and Safety Focus Area, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho 2735, South Africa
- Department of Animal Health, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho 2735, South Africa
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4
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Global Molecular Response of Paracoccidioides brasiliensis to Zinc Deprivation: Analyses at Transcript, Protein and MicroRNA Levels. J Fungi (Basel) 2023; 9:jof9030281. [PMID: 36983449 PMCID: PMC10056003 DOI: 10.3390/jof9030281] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/06/2023] [Accepted: 02/14/2023] [Indexed: 02/25/2023] Open
Abstract
Zinc is one of the main micronutrients for all organisms. One of the defense mechanisms used by the host includes the sequestration of metals used in fungal metabolism, such as iron and zinc. There are several mechanisms that maintain the balance in the intracellular zinc supply. MicroRNAs are effector molecules of responses between the pathogen and host, favoring or preventing infection in many microorganisms. Fungi of the Paracoccidioides genus are thermodimorphic and the etiological agents of paracoccidioidomycosis (PCM). In the current pandemic scenario world mycosis studies continue to be highly important since a significant number of patients with COVID-19 developed systemic mycoses, co-infections that complicated their clinical condition. The objective was to identify transcriptomic and proteomic adaptations in Paracoccidioides brasiliensis during zinc deprivation. Nineteen microRNAs were identified, three of which were differentially regulated. Target genes regulated by those microRNAs are elements of zinc homeostasis such as ZRT1, ZRT3 and COT1 transporters. Transcription factors that have zinc in their structure are also targets of those miRNAs. Transcriptional and proteomic data suggest that P. brasiliensis undergoes metabolic remodeling to survive zinc deprivation and that miRNAs may be part of the regulatory process.
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Seo H, Kang S, Lee D, Yun CW. Regulation of pseurotin A biosynthesis by GliZ and zinc in Aspergillus fumigatus. Sci Rep 2023; 13:2431. [PMID: 36765124 PMCID: PMC9918513 DOI: 10.1038/s41598-023-29753-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 02/09/2023] [Indexed: 02/12/2023] Open
Abstract
Recently, we reported that zinc regulates gliotoxin biosynthesis via ZafA, which is a zinc-responsive transcriptional activator. From an HPLC analysis of culture media of Aspergillus fumigatus, we found a trend of decreasing gliotoxin production but increasing pseurotin A and fumagillin production in proportion to the zinc concentration. The expression of the genes involved in pseurotin A biosynthesis was upregulated under high zinc concentrations. Furthermore, upregulated expression of pseurotin A biosynthetic genes and higher production of pseurotin A were observed in the zafA deletion strain. Interestingly, the deletion of gliZ, a transcriptional activator of gliotoxin biosynthesis genes, resulted in upregulated expression of pseurotin A biosynthetic genes and increased production of pseurotin A. We detected upregulation of fumR expression in the gliZ and zafA deletion mutants. The overexpression of gliZ observed in the zafA deletion mutant resulted in the failure of the mutant to increase pseurotin A production, which is a phenotype of the zafA deletion mutant. These results suggest that ZafA sequentially regulates pseurotin A biosynthesis through GliZ. Finally, we found through a murine virulence test that the gliZ and fumR double-deletion mutants showed a delayed death rate compared with the single-deletion mutants of either gliZ or fumR. Taken together, these results suggested that the biosynthesis of gliotoxin and pseurotin A are regulated in opposite ways by zinc utilization and that each secondary metabolite is synthesized when the synthesis of another secondary metabolite fails to protect it against the defense system of the host.
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Affiliation(s)
- Hyewon Seo
- School of Life Sciences and Biotechnology, Korea University, Anam-Dong, Sungbuk-Gu, Seoul, Republic of Korea
| | - Suzie Kang
- School of Life Sciences and Biotechnology, Korea University, Anam-Dong, Sungbuk-Gu, Seoul, Republic of Korea
| | - Dongho Lee
- Department of Plant Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Cheol-Won Yun
- School of Life Sciences and Biotechnology, Korea University, Anam-Dong, Sungbuk-Gu, Seoul, Republic of Korea.
- NeuroEsgel Co., Anam-Dong, Sungbuk-Gu, Seoul, Republic of Korea.
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6
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Fungal Zinc Homeostasis and Its Potential as an Antifungal Target: A Focus on the Human Pathogen Aspergillus fumigatus. Microorganisms 2022; 10:microorganisms10122469. [PMID: 36557722 PMCID: PMC9785309 DOI: 10.3390/microorganisms10122469] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/09/2022] [Accepted: 12/10/2022] [Indexed: 12/15/2022] Open
Abstract
Aspergillus fumigatus is an opportunistic airborne fungus that causes severe invasive aspergillosis in immunocompromised patients. Zinc is an essential micronutrient for the growth of A. fumigatus and even for all microorganisms. An increasing number of studies have reported that fungal zinc acquisition ability plays a key role in fungal survival in hosts with an extremely zinc-limited microenvironment. The ability to fight scarcity and excess of zinc are tightly related to fungal virulence and may be used as new potential targets. Because the regulation of zinc homeostasis is important, a thorough understanding of the functional genes involved in the regulatory network for zinc homeostasis is required for fungal pathogens. The current mini-review summarized potential zinc homeostasis regulators in A. fumigatus and classified these regulators according to localization and function, which were identified or predicted based on A. fumigatus or deduced from homologs in model yeasts. Future perspectives for zinc homeostasis regulators as potential antifungal targets to treat invasive aspergillosis are also discussed.
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7
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Ortiz SC, Pennington K, Thomson DD, Bertuzzi M. Novel Insights into Aspergillus fumigatus Pathogenesis and Host Response from State-of-the-Art Imaging of Host-Pathogen Interactions during Infection. J Fungi (Basel) 2022; 8:264. [PMID: 35330266 PMCID: PMC8954776 DOI: 10.3390/jof8030264] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 02/21/2022] [Accepted: 03/01/2022] [Indexed: 12/03/2022] Open
Abstract
Aspergillus fumigatus spores initiate more than 3,000,000 chronic and 300,000 invasive diseases annually, worldwide. Depending on the immune status of the host, inhalation of these spores can lead to a broad spectrum of disease, including invasive aspergillosis, which carries a 50% mortality rate overall; however, this mortality rate increases substantially if the infection is caused by azole-resistant strains or diagnosis is delayed or missed. Increasing resistance to existing antifungal treatments is becoming a major concern; for example, resistance to azoles (the first-line available oral drug against Aspergillus species) has risen by 40% since 2006. Despite high morbidity and mortality, the lack of an in-depth understanding of A. fumigatus pathogenesis and host response has hampered the development of novel therapeutic strategies for the clinical management of fungal infections. Recent advances in sample preparation, infection models and imaging techniques applied in vivo have addressed important gaps in fungal research, whilst questioning existing paradigms. This review highlights the successes and further potential of these recent technologies in understanding the host-pathogen interactions that lead to aspergillosis.
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Affiliation(s)
- Sébastien C Ortiz
- Manchester Academic Health Science Centre, Core Technology Facility, Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Grafton Street, Manchester M13 9NT, UK
| | - Katie Pennington
- Manchester Academic Health Science Centre, Core Technology Facility, Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Grafton Street, Manchester M13 9NT, UK
| | - Darren D Thomson
- Medical Research Council Centre for Medical Mycology, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK
| | - Margherita Bertuzzi
- Manchester Academic Health Science Centre, Core Technology Facility, Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Grafton Street, Manchester M13 9NT, UK
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8
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The putative role of zinc homeostasis in grain formation by Madurella mycetomatis during mycetoma infection. FUNGAL BIOL REV 2022. [DOI: 10.1016/j.fbr.2021.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Han LT, Wu YJ, Liu TB. The F-Box Protein Fbp1 Regulates Virulence of Cryptococcus neoformans Through the Putative Zinc-Binding Protein Zbp1. Front Cell Infect Microbiol 2022; 11:794661. [PMID: 35024357 PMCID: PMC8744115 DOI: 10.3389/fcimb.2021.794661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 12/06/2021] [Indexed: 11/13/2022] Open
Abstract
The ubiquitin-proteasome system (UPS) is the major protein turnover mechanism that plays an important role in regulating various cellular functions. F-box proteins are the key proteins of the UPS, responsible for the specific recognition and ubiquitination of downstream targets. Our previous studies showed that the F-box protein Fbp1 plays an essential role in the virulence of C. neoformans. However, the molecular mechanism of Fbp1 regulating the virulence of C. neoformans is still unclear. In this study, we analyzed the potential Fbp1 substrates using an iTRAQ-based proteomic approach and identified the zinc-binding protein Zbp1 as a substrate of Fbp1. Protein interaction and stability assays showed that Zbp1 interacts with Fbp1 and is a downstream target of Fbp1. Ubiquitination analysis in vivo showed that the ubiquitination of Zbp1 is dependent on Fbp1 in C. neoformans. Subcellular localization analysis revealed that the Zbp1 protein was localized in the nucleus of C. neoformans cells. In addition, both deletion and overexpression of the ZBP1 gene led to the reduced capsule size, while overexpression has a more significant impact on capsule size reduction. Fungal virulence assays showed that although the zbp1Δ mutants are virulent, virulence was significantly attenuated in the ZBP1 overexpression strains. Fungal load assay showed that the fungal burdens recovered from the mouse lungs decreased gradually after infection, while no yeast cells were recovered from the brains and spleens of the mice infected by ZBP1 overexpression strains. Thus, our results revealed a new determinant of fungal virulence involving the post-translational regulation of a zinc-binding protein.
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Affiliation(s)
- Lian-Tao Han
- State Key Laboratory of Silkworm Genomic Biology, Southwest University, Chongqing, China.,Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
| | - Yu-Juan Wu
- State Key Laboratory of Silkworm Genomic Biology, Southwest University, Chongqing, China.,Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
| | - Tong-Bao Liu
- State Key Laboratory of Silkworm Genomic Biology, Southwest University, Chongqing, China.,Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China.,Medical Research Institute, Southwest University, Chongqing, China
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10
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Fear-of-intimacy-mediated zinc transport controls fat body cell dissociation through modulating Mmp activity in Drosophila. Cell Death Dis 2021; 12:874. [PMID: 34564691 PMCID: PMC8464599 DOI: 10.1038/s41419-021-04147-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 08/17/2021] [Accepted: 09/08/2021] [Indexed: 12/20/2022]
Abstract
Matrix metalloproteinases (Mmps) are pivotal extracellular proteinases that have been implicated in tumour invasion and metastasis. Drosophila fat body is important for energy storage and utilization, as well as biosynthetic and metabolic activities. The fat body undergoes remodelling during metamorphosis which is characterized by the dissociation of the fat body into individual cells. Mmps play important roles in the regulation of fat body cell dissociation. Here we show that a zinc transporter fear-of-intimacy (foi) is necessary for the cell dissociation of fat body in Drosophila. The progression of fat body cell dissociation was delayed by fat body-specific foi knockdown while it was accelerated by foi overexpression (OE). In essence, these phenotypes are closely associated with intracellular zinc homeostasis, which can be modulated by dietary zinc intervention or genetic modulation of other zinc transporters. Further study indicated that Mmp1 and Mmp2 levels could be transcriptionally regulated by zinc in vivo. Consistently, the retarded fat body cell dissociation caused by Mmp1 or Mmp2 RNAi could be regulated by modulating the expression of foi. Further, by using Drosophila models of malignant tumour RafGOFscrib−/− and RasV12lgl−/−, we showed that the tumour growth, invasion and migration could be markedly inhibited by foi knockdown. These findings demonstrate a close connection between zinc levels and cell dissociation in vivo, and also suggest that manipulation of zinc levels may provide a novel therapeutic strategy for cancer.
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11
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Earl Kang S, Celia BN, Bensasson D, Momany M. Sporulation environment drives phenotypic variation in the pathogen Aspergillus fumigatus. G3 (BETHESDA, MD.) 2021; 11:jkab208. [PMID: 34849823 PMCID: PMC8496221 DOI: 10.1093/g3journal/jkab208] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 06/11/2021] [Indexed: 01/10/2023]
Abstract
Aspergillus fumigatus causes more than 300,000 life-threatening infections annually and is widespread across varied environments with a single colony producing thousands of conidia, genetically identical dormant spores. Conidia are easily wind-dispersed to new environments where they can germinate and, if inhaled by susceptible hosts, cause disease. Using high-throughput single-cell analysis via flow cytometry we analyzed conidia produced and germinated in nine environmentally and medically relevant conditions (complete medium, minimal medium, high temperature, excess copper, excess iron, limited iron, excess salt, excess reactive oxygen species, and limited zinc). We found that germination phenotypes vary among genetically identical individuals, that the environment of spore production determines the size of spores and the degree of germination heterogeneity, and that the environment of spore production impacts virulence in a Galleria mellonella host.
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Affiliation(s)
- S Earl Kang
- Fungal Biology Group & Plant Biology Department, University of Georgia, Athens, GA 30602, USA
| | - Brandi N Celia
- Fungal Biology Group & Plant Biology Department, University of Georgia, Athens, GA 30602, USA
| | - Douda Bensasson
- Institute of Bioinformatics & Plant Biology Department, University of Georgia, Athens, GA 30602, USA
| | - Michelle Momany
- Fungal Biology Group & Plant Biology Department, University of Georgia, Athens, GA 30602, USA
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12
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Nitrogen, Iron and Zinc Acquisition: Key Nutrients to Aspergillus fumigatus Virulence. J Fungi (Basel) 2021; 7:jof7070518. [PMID: 34203370 PMCID: PMC8303583 DOI: 10.3390/jof7070518] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/24/2021] [Accepted: 06/24/2021] [Indexed: 12/31/2022] Open
Abstract
Aspergillus fumigatus is a ubiquitous soil decomposer and an opportunistic pathogen that is characterized by its large metabolic machinery for acquiring nutrients from media. Lately, an ever-increasing number of genes involved in fungal nutrition has been associated with its virulence. Of these, nitrogen, iron, and zinc metabolism-related genes are particularly noteworthy, since 78% of them have a direct implication in virulence. In this review, we describe the sensing, uptake and regulation process of the acquisition of these nutrients, the connections between pathways and the virulence-implicated genes. Nevertheless, only 40% of the genes mentioned in this review have been assayed for roles in virulence, leaving a wide field of knowledge that remains uncertain and might offer new therapeutic and diagnostic targets.
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13
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Johns LE, Goldman GH, Ries LN, Brown NA. Nutrient sensing and acquisition in fungi: mechanisms promoting pathogenesis in plant and human hosts. FUNGAL BIOL REV 2021. [DOI: 10.1016/j.fbr.2021.01.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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14
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Tamez-Castrellón AK, Romeo O, García-Carnero LC, Lozoya-Pérez NE, Mora-Montes HM. Virulence Factors in Sporothrix schenckii, One of the Causative Agents of Sporotrichosis. Curr Protein Pept Sci 2021; 21:295-312. [PMID: 31589121 DOI: 10.2174/1389203720666191007103004] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 08/02/2019] [Accepted: 08/08/2019] [Indexed: 11/22/2022]
Abstract
Sporothrix schenckii is one of the etiological agents of sporotrichosis, a fungal infection distributed worldwide. Both, the causative organism and the disease have currently received limited attention by the medical mycology community, most likely because of the low mortality rates associated with it. Nonetheless, morbidity is high in endemic regions and the versatility of S. schenckii to cause zoonosis and sapronosis has attracted attention. Thus far, virulence factors associated with this organism are poorly described. Here, comparing the S. schenckii genome sequence with other medically relevant fungi, genes involved in morphological change, cell wall synthesis, immune evasion, thermotolerance, adhesion, biofilm formation, melanin production, nutrient uptake, response to stress, extracellular vesicle formation, and toxin production are predicted and discussed as putative virulence factors in S. schenckii.
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Affiliation(s)
- Alma K Tamez-Castrellón
- Departamento de Biología, División de Ciencias Naturales y Exactas, Campus Guanajuato, Universidad de Guanajuato, Noria Alta s/n, col. Noria Alta, C.P. 36050, Guanajuato, Gto., Mexico
| | - Orazio Romeo
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Laura C García-Carnero
- Departamento de Biología, División de Ciencias Naturales y Exactas, Campus Guanajuato, Universidad de Guanajuato, Noria Alta s/n, col. Noria Alta, C.P. 36050, Guanajuato, Gto., Mexico
| | - Nancy E Lozoya-Pérez
- Departamento de Biología, División de Ciencias Naturales y Exactas, Campus Guanajuato, Universidad de Guanajuato, Noria Alta s/n, col. Noria Alta, C.P. 36050, Guanajuato, Gto., Mexico
| | - Héctor M Mora-Montes
- Departamento de Biología, División de Ciencias Naturales y Exactas, Campus Guanajuato, Universidad de Guanajuato, Noria Alta s/n, col. Noria Alta, C.P. 36050, Guanajuato, Gto., Mexico
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15
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Assunção LDP, Moraes D, Soares LW, Silva-Bailão MG, de Siqueira JG, Baeza LC, Báo SN, Soares CMDA, Bailão AM. Insights Into Histoplasma capsulatum Behavior on Zinc Deprivation. Front Cell Infect Microbiol 2020; 10:573097. [PMID: 33330123 PMCID: PMC7734293 DOI: 10.3389/fcimb.2020.573097] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 10/21/2020] [Indexed: 11/13/2022] Open
Abstract
Histoplasma capsulatum is a thermodimorphic fungus that causes histoplasmosis, a mycosis of global incidence. The disease is prevalent in temperate and tropical regions such as North America, South America, Europe, and Asia. It is known that during infection macrophages restrict Zn availability to H. capsulatum as a microbicidal mechanism. In this way the present work aimed to study the response of H. capsulatum to zinc deprivation. In silico analyses showed that H. capsulatum has eight genes related to zinc homeostasis ranging from transcription factors to CDF and ZIP family transporters. The transcriptional levels of ZAP1, ZRT1, and ZRT2 were induced under zinc-limiting conditions. The decrease in Zn availability increases fungicidal macrophage activity. Proteomics analysis during zinc deprivation at 24 and 48 h showed 265 proteins differentially expressed at 24 h and 68 at 48 h. Proteins related to energy production pathways, oxidative stress, and cell wall remodeling were regulated. The data also suggested that low metal availability increases the chitin and glycan content in fungal cell wall that results in smoother cell surface. Metal restriction also induces oxidative stress triggered, at least in part, by reduction in pyridoxin synthesis.
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Affiliation(s)
- Leandro do Prado Assunção
- Molecular Biology and Biochemistry Laboratory, Institute of Biological Sciences II, Federal University of Goias (UFG), Goiania, Brazil
| | - Dayane Moraes
- Molecular Biology and Biochemistry Laboratory, Institute of Biological Sciences II, Federal University of Goias (UFG), Goiania, Brazil
| | - Lucas Weba Soares
- Molecular Biology and Biochemistry Laboratory, Institute of Biological Sciences II, Federal University of Goias (UFG), Goiania, Brazil
| | - Mirelle Garcia Silva-Bailão
- Molecular Biology and Biochemistry Laboratory, Institute of Biological Sciences II, Federal University of Goias (UFG), Goiania, Brazil
| | - Janaina Gomes de Siqueira
- Molecular Biology and Biochemistry Laboratory, Institute of Biological Sciences II, Federal University of Goias (UFG), Goiania, Brazil
| | - Lilian Cristiane Baeza
- Laboratory of Experimental Microbiology, State University of Western Paraná (Unioeste), Cascavel, Brazil
| | - Sônia Nair Báo
- Microscopy and Microanalysis Laboratory, Institute of Biological Sciences, Brasília University (UnB), Brasilia, Brazil
| | - Célia Maria de Almeida Soares
- Molecular Biology and Biochemistry Laboratory, Institute of Biological Sciences II, Federal University of Goias (UFG), Goiania, Brazil
| | - Alexandre Melo Bailão
- Molecular Biology and Biochemistry Laboratory, Institute of Biological Sciences II, Federal University of Goias (UFG), Goiania, Brazil
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16
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Soares LW, Bailão AM, Soares CMDA, Bailão MGS. Zinc at the Host-Fungus Interface: How to Uptake the Metal? J Fungi (Basel) 2020; 6:jof6040305. [PMID: 33233335 PMCID: PMC7711662 DOI: 10.3390/jof6040305] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 11/11/2020] [Accepted: 11/12/2020] [Indexed: 12/31/2022] Open
Abstract
Zinc is an essential nutrient for all living organisms. However, firm regulation must be maintained since micronutrients also can be toxic in high concentrations. This notion is reinforced when we look at mechanisms deployed by our immune system, such as the use of chelators or membrane transporters that capture zinc, when threatened with pathogens, like fungi. Pathogenic fungi, on the other hand, also make use of a variety of transporters and specialized zinc captors to survive these changes. In this review, we sought to explain the mechanisms, grounded in experimental analysis and described to date, utilized by pathogenic fungi to maintain optimal zinc levels.
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17
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Kang S, Seo H, Moon HS, Kwon JH, Park YS, Yun CW. The Role of Zinc in Copper Homeostasis of Aspergillus fumigatus. Int J Mol Sci 2020; 21:ijms21207665. [PMID: 33081273 PMCID: PMC7593903 DOI: 10.3390/ijms21207665] [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: 09/15/2020] [Revised: 10/14/2020] [Accepted: 10/14/2020] [Indexed: 11/16/2022] Open
Abstract
Copper is an essential metal ion that performs many physiological functions in living organisms. Deletion of Afmac1, which is a copper-responsive transcriptional activator in A. fumigatus, results in a growth defect on aspergillus minimal medium (AMM). Interestingly, we found that zinc starvation suppressed the growth defect of the Δafmac1 strain on AMM. In addition, the growth defect of the Δafmac1 strain was recovered by copper supplementation or introduction of the CtrC gene into the Δafmac1 strain. However, chelation of copper by addition of BCS to AMM failed to recover the growth defect of the Δafmac1 strain. Through Northern blot analysis, we found that zinc starvation upregulated CtrC and CtrA2, which encode membrane copper transporters. Interestingly, we found that the conserved ZafA binding motif 5'-CAA(G)GGT-3' was present in the upstream region of CtrC and CtrA2 and that mutation of the binding motif led to failure of ZafA binding to the upstream region of CtrC and upregulation of CtrC expression under zinc starvation. Furthermore, the binding activity of ZafA to the upstream region of CtrC was inversely proportional to the zinc concentration, and copper inhibited the binding of ZafA to the upstream region of CtrC under a low zinc concentration. Taken together, these results suggest that ZafA upregulates copper metabolism by binding to the ZafA binding motif in the CtrC promoter region under low zinc concentration, thus regulating copper homeostasis. Furthermore, we found that copper and zinc interact in cells to maintain metal homeostasis.
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Affiliation(s)
| | | | | | | | | | - Cheol-Won Yun
- Correspondence: ; Tel.: +82-2-3290-3456; Fax: +82-2-927-9028
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18
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Gonçalves LNC, Costa-Orlandi CB, Bila NM, Vaso CO, Da Silva RAM, Mendes-Giannini MJS, Taylor ML, Fusco-Almeida AM. Biofilm Formation by Histoplasma capsulatum in Different Culture Media and Oxygen Atmospheres. Front Microbiol 2020; 11:1455. [PMID: 32754126 PMCID: PMC7365857 DOI: 10.3389/fmicb.2020.01455] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 06/04/2020] [Indexed: 12/13/2022] Open
Abstract
Histoplasma capsulatum is a dimorphic fungus that causes an important systemic mycosis called histoplasmosis. It is an infectious disease with high prevalence and morbidity that affects the general population. Recently, the ability of these fungi to form biofilms, a phenotype that can induce resistance and enhance virulence, has been described. Despite some efforts, data regarding the impact of nutrients and culture media that affect the H. capsulatum biofilm development in vitro are not yet available. This work aimed to study H. capsulatum biofilms, by checking the influence of different culture media and oxygen atmospheres in the development of these communities. The biofilm formation by two strains (EH-315 and G186A) was characterized under different culture media: [Brain and Heart Infusion (BHI), Roswell Park Memorial Institute (RPMI) with 2% glucose, Dulbecco’s Modified Eagle’s Medium (DMEM) supplemented with 10% fetal bovine serum and nutrient medium HAM-F12 (HAM-F12) supplemented with glucose (18.2 g/L), glutamic acid (1 g/L), HEPES (6 g/L) and L-cysteine (8.4 mg/L)] and oxygen atmospheres (aerobiosis and microaerophilia), using the XTT reduction assay to quantify metabolic activities, crystal violet staining for biomass, safranin staining for the quantification of polysaccharide material and scanning electron microscopy (SEM) for the observation of topographies. Results indicated that although all culture mediums have stimulated the maturation of the communities, HAM-F12 provided the best development of biomass and polysaccharide material when compared to others. Regarding the oxygen atmospheres, both stimulated an excellent development of the communities, however in low oxygen conditions an exuberant amount of extracellular matrix was observed when compared to biofilms formed in aerobiosis, mainly in the HAM-F12 media. SEM images showed yeasts embedded by an extracellular matrix in several points, corroborating the colorimetric assays. However, biofilms formed in BHI, RPMI, and DMEM significantly induced yeast to hyphae reversal, requiring further investigation. The results obtained so far contribute to in vitro study of biofilms formed by these fungi and show that nutrition promoted by different media modifies the development of these communities. These data represent advances in the field of biofilms and contribute to future studies that can prove the role of these communities in the fungi-host interaction.
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Affiliation(s)
| | - Caroline Barcelos Costa-Orlandi
- School of Pharmaceutical Sciences, Department of Clinical Analysis, Universidade Estadual Paulista (UNESP), Araraquara, Brazil
| | - Níura Madalena Bila
- School of Pharmaceutical Sciences, Department of Clinical Analysis, Universidade Estadual Paulista (UNESP), Araraquara, Brazil.,School of Veterinary, Department of Para Clinic, Universidade Eduardo Mondlane, Maputo, Mozambique
| | - Carolina Orlando Vaso
- School of Pharmaceutical Sciences, Department of Clinical Analysis, Universidade Estadual Paulista (UNESP), Araraquara, Brazil
| | | | | | - Maria Lucia Taylor
- School of Medicine, Department of Microbiology and Parasitology, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Ana Marisa Fusco-Almeida
- School of Pharmaceutical Sciences, Department of Clinical Analysis, Universidade Estadual Paulista (UNESP), Araraquara, Brazil
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19
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Identification and characterization of the ZRT, IRT-like protein (ZIP) family genes reveal their involvement in growth and kojic acid production in Aspergillus oryzae. ACTA ACUST UNITED AC 2019; 46:1769-1780. [DOI: 10.1007/s10295-019-02236-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 09/11/2019] [Indexed: 12/31/2022]
Abstract
Abstract
The ZRT, IRT-like protein (ZIP) family exists in many species and plays an important role in many biological processes, but little is known about ZIP genes in Aspergillus oryzae. Here, 10 ZIP genes in A. oryzae were identified and these were classified into four groups based on phylogenetic analysis. The structures of these AoZip genes were determined, which indicated a great divergence of AoZip members from different groups. Synteny analysis revealed that AoZip7, AoZip8, and AoZip10 are conserved among Aspergillus species. We also found that the promoter regions of AoZip2, AoZip7, AoZip8, and AoZip10 contain multiple conserved response elements. Expression analysis revealed that AoZips exhibited different expression patterns in response to different metal treatments. Moreover, overexpression and RNA-interference (RNAi) of AoZip2 led to a decrease in mycelium growth diameter and inhibited conidia formation. AoZip2 overexpression and RNAi strains showed distinct sensitivity to severely Zn/Mn-depleted stress. In addition, kojic acid production was markedly lower in AoZip2 overexpression and RNAi strains than in the control strains, and the expression of kojA, kojR, and kojT was down-regulated in AoZip2 overexpression and RNAi strains. This study provides new insights into our understanding of ZIP genes and lays a foundation for further investigation of their roles in Aspergillus oryzae.
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20
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Vicentefranqueira R, Leal F, Marín L, Sánchez CI, Calera JA. The interplay between zinc and iron homeostasis in
Aspergillus fumigatus
under zinc‐replete conditions relies on the iron‐mediated regulation of alternative transcription units of
zafA
and the basal amount of the ZafA zinc‐responsiveness transcription factor. Environ Microbiol 2019; 21:2787-2808. [DOI: 10.1111/1462-2920.14618] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 04/03/2019] [Indexed: 12/27/2022]
Affiliation(s)
- Rocío Vicentefranqueira
- Instituto de Biología Funcional y Genómica (IBFG‐CSIC)Universidad de Salamanca Salamanca Spain
| | - Fernando Leal
- Instituto de Biología Funcional y Genómica (IBFG‐CSIC)Universidad de Salamanca Salamanca Spain
- Departamento de Microbiología y GenéticaUniversidad de Salamanca Salamanca Spain
| | - Laura Marín
- Instituto de Biología Funcional y Genómica (IBFG‐CSIC)Universidad de Salamanca Salamanca Spain
| | - Clara Inés Sánchez
- Instituto de Biología Funcional y Genómica (IBFG‐CSIC)Universidad de Salamanca Salamanca Spain
| | - José Antonio Calera
- Instituto de Biología Funcional y Genómica (IBFG‐CSIC)Universidad de Salamanca Salamanca Spain
- Departamento de Microbiología y GenéticaUniversidad de Salamanca Salamanca Spain
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21
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The Transcription Factor ZafA Regulates the Homeostatic and Adaptive Response to Zinc Starvation in Aspergillus fumigatus. Genes (Basel) 2018; 9:genes9070318. [PMID: 29949939 PMCID: PMC6070888 DOI: 10.3390/genes9070318] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 06/20/2018] [Accepted: 06/20/2018] [Indexed: 12/20/2022] Open
Abstract
One of the most important features that enables Aspergillus fumigatus to grow within a susceptible individual and to cause disease is its ability to obtain Zn2+ ions from the extremely zinc-limited environment provided by host tissues. Zinc uptake from this source in A. fumigatus relies on ZIP transporters encoded by the zrfA, zrfB and zrfC genes. The expression of these genes is tightly regulated by the ZafA transcription factor that regulates zinc homeostasis and is essential for A. fumigatus virulence. We combined the use of microarrays, Electrophoretic Mobility Shift Assays (EMSA) analyses, DNase I footprinting assays and in silico tools to better understand the regulation of the homeostatic and adaptive response of A. fumigatus to zinc starvation. We found that under zinc-limiting conditions, ZafA functions mainly as a transcriptional activator through binding to a zinc response sequence located in the regulatory regions of its target genes, although it could also function as a repressor of a limited number of genes. In addition to genes involved in the homeostatic response to zinc deficiency, ZafA also influenced, either directly or indirectly, the expression of many other genes. It is remarkable that the expression of many genes involved in iron uptake and ergosterol biosynthesis is strongly reduced under zinc starvation, even though only the expression of some of these genes appeared to be influenced directly or indirectly by ZafA. In addition, it appears to exist in A. fumigatus a zinc/iron cross-homeostatic network to allow the adaptation of the fungus to grow in media containing unbalanced Zn:Fe ratios. The adaptive response to oxidative stress typically linked to zinc starvation was also mediated by ZafA, as was the strong induction of genes involved in gliotoxin biosynthesis and self-protection against endogenous gliotoxin. This study has expanded our knowledge about the regulatory and metabolic changes displayed by A. fumigatus in response to zinc starvation and has helped us to pinpoint new ZafA target genes that could be important for fungal pathogens to survive and grow within host tissues and, hence, for virulence.
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22
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Garcia Silva-Bailão M, Lobato Potenciano da Silva K, Raniere Borges dos Anjos L, de Sousa Lima P, de Melo Teixeira M, Maria de Almeida Soares C, Melo Bailão A. Mechanisms of copper and zinc homeostasis in pathogenic black fungi. Fungal Biol 2018; 122:526-537. [DOI: 10.1016/j.funbio.2017.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 12/01/2017] [Accepted: 12/04/2017] [Indexed: 02/08/2023]
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23
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Kurucz V, Krüger T, Antal K, Dietl AM, Haas H, Pócsi I, Kniemeyer O, Emri T. Additional oxidative stress reroutes the global response of Aspergillus fumigatus to iron depletion. BMC Genomics 2018; 19:357. [PMID: 29747589 PMCID: PMC5946477 DOI: 10.1186/s12864-018-4730-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 04/26/2018] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Aspergillus fumigatus has to cope with a combination of several stress types while colonizing the human body. A functional interplay between these different stress responses can increase the chances of survival for this opportunistic human pathogen during the invasion of its host. In this study, we shed light on how the H2O2-induced oxidative stress response depends on the iron available to this filamentous fungus, using transcriptomic analysis, proteomic profiles, and growth assays. RESULTS The applied H2O2 treatment, which induced only a negligible stress response in iron-replete cultures, deleteriously affected the fungus under iron deprivation. The majority of stress-induced changes in gene and protein expression was not predictable from data coming from individual stress exposure and was only characteristic for the combination of oxidative stress plus iron deprivation. Our experimental data suggest that the physiological effects of combined stresses and the survival of the fungus highly depend on fragile balances between economization of iron and production of essential iron-containing proteins. One observed strategy was the overproduction of iron-independent antioxidant proteins to combat oxidative stress during iron deprivation, e.g. the upregulation of superoxide dismutase Sod1, the thioredoxin reductase Trr1, and the thioredoxin orthologue Afu5g11320. On the other hand, oxidative stress induction overruled iron deprivation-mediated repression of several genes. In agreement with the gene expression data, growth studies underlined that in A. fumigatus iron deprivation aggravates oxidative stress susceptibility. CONCLUSIONS Our data demonstrate that studying stress responses under separate single stress conditions is not sufficient to understand how A. fumigatus adapts in a complex and hostile habitat like the human body. The combinatorial stress of iron depletion and hydrogen peroxide caused clear non-additive effects upon the stress response of A. fumigatus. Our data further supported the view that the ability of A. fumigatus to cause diseases in humans strongly depends on its fitness attributes and less on specific virulence factors. In summary, A. fumigatus is able to mount and coordinate complex and efficient responses to combined stresses like iron deprivation plus H2O2-induced oxidative stress, which are exploited by immune cells to kill fungal pathogens.
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Affiliation(s)
- Vivien Kurucz
- Department of Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, Debrecen, H-4032 Hungary
| | - Thomas Krüger
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), 07745 Jena, Germany
| | - Károly Antal
- Department of Zoology, Faculty of Sciences, Eszterházy Károly University, Eszterházy tér 1, Eger, H-3300 Hungary
| | - Anna-Maria Dietl
- Division of Molecular Biology, Biocenter, Medical University of Innsbruck, A6020 Innsbruck, Austria
| | - Hubertus Haas
- Division of Molecular Biology, Biocenter, Medical University of Innsbruck, A6020 Innsbruck, Austria
| | - István Pócsi
- Department of Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, Debrecen, H-4032 Hungary
| | - Olaf Kniemeyer
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), 07745 Jena, Germany
| | - Tamás Emri
- Department of Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, Debrecen, H-4032 Hungary
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24
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Lehtovirta-Morley LE, Alsarraf M, Wilson D. Pan-Domain Analysis of ZIP Zinc Transporters. Int J Mol Sci 2017; 18:E2631. [PMID: 29211002 PMCID: PMC5751234 DOI: 10.3390/ijms18122631] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 12/01/2017] [Accepted: 12/01/2017] [Indexed: 12/13/2022] Open
Abstract
The ZIP (Zrt/Irt-like protein) family of zinc transporters is found in all three domains of life. However, little is known about the phylogenetic relationship amongst ZIP transporters, their distribution, or their origin. Here we employed phylogenetic analysis to explore the evolution of ZIP transporters, with a focus on the major human fungal pathogen, Candida albicans. Pan-domain analysis of bacterial, archaeal, fungal, and human proteins revealed a complex relationship amongst the ZIP family members. Here we report (i) a eukaryote-wide group of cellular zinc importers, (ii) a fungal-specific group of zinc importers having genetic association with the fungal zincophore, and, (iii) a pan-kingdom supercluster made up of two distinct subgroups with orthologues in bacterial, archaeal, and eukaryotic phyla.
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Affiliation(s)
- Laura E Lehtovirta-Morley
- Aberdeen Fungal Group, Medical Research Council Centre for Medical Mycology, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK.
- School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
| | - Mohammad Alsarraf
- Aberdeen Fungal Group, Medical Research Council Centre for Medical Mycology, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK.
| | - Duncan Wilson
- Aberdeen Fungal Group, Medical Research Council Centre for Medical Mycology, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK.
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25
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Juvvadi PR. Balancing iron and calcium: Flavin carrier family proteins in Aspergillus fumigatus virulence. Virulence 2017; 8:621-624. [PMID: 27820672 PMCID: PMC5626335 DOI: 10.1080/21505594.2016.1257459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 10/31/2016] [Indexed: 10/20/2022] Open
Affiliation(s)
- Praveen R. Juvvadi
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University School of Medicine, Durham, NC, USA
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26
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Paulussen C, Hallsworth JE, Álvarez‐Pérez S, Nierman WC, Hamill PG, Blain D, Rediers H, Lievens B. Ecology of aspergillosis: insights into the pathogenic potency of Aspergillus fumigatus and some other Aspergillus species. Microb Biotechnol 2017; 10:296-322. [PMID: 27273822 PMCID: PMC5328810 DOI: 10.1111/1751-7915.12367] [Citation(s) in RCA: 179] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 04/08/2016] [Accepted: 04/18/2016] [Indexed: 01/26/2023] Open
Abstract
Fungi of the genus Aspergillus are widespread in the environment. Some Aspergillus species, most commonly Aspergillus fumigatus, may lead to a variety of allergic reactions and life-threatening systemic infections in humans. Invasive aspergillosis occurs primarily in patients with severe immunodeficiency, and has dramatically increased in recent years. There are several factors at play that contribute to aspergillosis, including both fungus and host-related factors such as strain virulence and host pulmonary structure/immune status, respectively. The environmental tenacity of Aspergilllus, its dominance in diverse microbial communities/habitats, and its ability to navigate the ecophysiological and biophysical challenges of host infection are attributable, in large part, to a robust stress-tolerance biology and exceptional capacity to generate cell-available energy. Aspects of its stress metabolism, ecology, interactions with diverse animal hosts, clinical presentations and treatment regimens have been well-studied over the past years. Here, we synthesize these findings in relation to the way in which some Aspergillus species have become successful opportunistic pathogens of human- and other animal hosts. We focus on the biophysical capabilities of Aspergillus pathogens, key aspects of their ecophysiology and the flexibility to undergo a sexual cycle or form cryptic species. Additionally, recent advances in diagnosis of the disease are discussed as well as implications in relation to questions that have yet to be resolved.
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Affiliation(s)
- Caroline Paulussen
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM)Department of Microbial and Molecular Systems (M2S)KU LeuvenCampus De NayerSint‐Katelijne‐WaverB‐2860Belgium
| | - John E. Hallsworth
- Institute for Global Food SecuritySchool of Biological SciencesMedical Biology CentreQueen's University BelfastBelfastBT9 7BLUK
| | - Sergio Álvarez‐Pérez
- Faculty of Veterinary MedicineDepartment of Animal HealthUniversidad Complutense de MadridMadridE‐28040Spain
| | | | - Philip G. Hamill
- Institute for Global Food SecuritySchool of Biological SciencesMedical Biology CentreQueen's University BelfastBelfastBT9 7BLUK
| | - David Blain
- Institute for Global Food SecuritySchool of Biological SciencesMedical Biology CentreQueen's University BelfastBelfastBT9 7BLUK
| | - Hans Rediers
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM)Department of Microbial and Molecular Systems (M2S)KU LeuvenCampus De NayerSint‐Katelijne‐WaverB‐2860Belgium
| | - Bart Lievens
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM)Department of Microbial and Molecular Systems (M2S)KU LeuvenCampus De NayerSint‐Katelijne‐WaverB‐2860Belgium
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27
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Bultman KM, Kowalski CH, Cramer RA. Aspergillus fumigatus virulence through the lens of transcription factors. Med Mycol 2016; 55:24-38. [PMID: 27816905 DOI: 10.1093/mmy/myw120] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 08/19/2016] [Accepted: 10/17/2016] [Indexed: 02/07/2023] Open
Abstract
Invasive aspergillosis (IA), most commonly caused by the filamentous fungus Aspergillus fumigatus, occurs in immune compromised individuals. The ability of A. fumigatus to proliferate in a multitude of environments is hypothesized to contribute to its pathogenicity and virulence. Transcription factors (TF) have long been recognized as critical proteins for fungal pathogenicity, as many are known to play important roles in the transcriptional regulation of pathways implicated in virulence. Such pathways include regulation of conidiation and development, adhesion, nutrient acquisition, adaptation to environmental stress, and interactions with the host immune system among others. In both murine and insect models of IA, TF loss of function in A. fumigatus results in cases of hyper- and hypovirulence as determined through host survival, fungal burden, and immune response analyses. Consequently, the study of specific TFs in A. fumigatus has revealed important insights into mechanisms of pathogenicity and virulence. Although in vitro studies have identified virulence-related functions of specific TFs, the full picture of their in vivo functions remain largely enigmatic and an exciting area of current research. Moreover, the vast majority of TFs remain to be characterized and studied in this important human pathogen. Here in this mini-review we provide an overview of selected TFs in A. fumigatus and their contribution to our understanding of this important human pathogen's pathogenicity and virulence.
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Affiliation(s)
- Katherine M Bultman
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Caitlin H Kowalski
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Robert A Cramer
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
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28
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Wątły J, Potocki S, Rowińska-Żyrek M. Zinc Homeostasis at the Bacteria/Host Interface-From Coordination Chemistry to Nutritional Immunity. Chemistry 2016; 22:15992-16010. [DOI: 10.1002/chem.201602376] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Indexed: 12/17/2022]
Affiliation(s)
- Joanna Wątły
- Faculty of Chemistry; University of Wroclaw; F. Joliot-Curie 14 50-383 Wroclaw Poland
| | - Sławomir Potocki
- Faculty of Chemistry; University of Wroclaw; F. Joliot-Curie 14 50-383 Wroclaw Poland
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29
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Croft CA, Culibrk L, Moore MM, Tebbutt SJ. Interactions of Aspergillus fumigatus Conidia with Airway Epithelial Cells: A Critical Review. Front Microbiol 2016; 7:472. [PMID: 27092126 PMCID: PMC4823921 DOI: 10.3389/fmicb.2016.00472] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 03/21/2016] [Indexed: 02/05/2023] Open
Abstract
Aspergillus fumigatus is an environmental filamentous fungus that also acts as an opportunistic pathogen able to cause a variety of symptoms, from an allergic response to a life-threatening disseminated fungal infection. The infectious agents are inhaled conidia whose first point of contact is most likely to be an airway epithelial cell (AEC). The interaction between epithelial cells and conidia is multifaceted and complex, and has implications for later steps in pathogenesis. Increasing evidence has demonstrated a key role for the airway epithelium in the response to respiratory pathogens, particularly at early stages of infection; therefore, elucidating the early stages of interaction of conidia with AECs is essential to understand the establishment of infection in cohorts of at-risk patients. Here, we present a comprehensive review of the early interactions between A. fumigatus and AECs, including bronchial and alveolar epithelial cells. We describe mechanisms of adhesion, internalization of conidia by AECs, the immune response of AECs, as well as the role of fungal virulence factors, and patterns of fungal gene expression characteristic of early infection. A clear understanding of the mechanisms involved in the early establishment of infection by A. fumigatus could point to novel targets for therapy and prophylaxis.
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Affiliation(s)
- Carys A Croft
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver BC, Canada
| | - Luka Culibrk
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver BC, Canada
| | - Margo M Moore
- Department of Biological Sciences, Simon Fraser University, Burnaby BC, Canada
| | - Scott J Tebbutt
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, VancouverBC, Canada; Prevention of Organ Failure Centre of Excellence, VancouverBC, Canada; Department of Medicine, Division of Respiratory Medicine, University of British Columbia, VancouverBC, Canada
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30
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Abstract
The mammalian immune system has evolved sophisticated mechanisms to withhold essential micronutrients from invading pathogens. These processes, collectively known as nutritional immunity serve to limit microbial proliferation and bolster killing of the invader. Successful pathogens, therefore, have developed strategies to counteract nutritional immunity and acquire essential micronutrients in the restrictive environment of the infected host. Here I take advantage of the now large number of sequenced fungal genomes to explore the zinc acquisition strategies of human fungal pathogens and reflect on the evolutionary context of these uptake pathways.
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Affiliation(s)
- Duncan Wilson
- Aberdeen Fungal Group, School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.
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31
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Dietl AM, Amich J, Leal S, Beckmann N, Binder U, Beilhack A, Pearlman E, Haas H. Histidine biosynthesis plays a crucial role in metal homeostasis and virulence of Aspergillus fumigatus. Virulence 2016; 7:465-76. [PMID: 26854126 PMCID: PMC4871644 DOI: 10.1080/21505594.2016.1146848] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Aspergillus fumigatus is the most prevalent airborne fungal pathogen causing invasive fungal infections in immunosuppressed individuals. The histidine biosynthetic pathway is found in bacteria, archaebacteria, lower eukaryotes, and plants, but is absent in mammals. Here we demonstrate that deletion of the gene encoding imidazoleglycerol-phosphate dehydratase (HisB) in A. fumigatus causes (i) histidine auxotrophy, (ii) decreased resistance to both starvation and excess of various heavy metals, including iron, copper and zinc, which play a pivotal role in antimicrobial host defense, (iii) attenuation of pathogenicity in 4 virulence models: murine pulmonary infection, murine systemic infection, murine corneal infection, and wax moth larvae. In agreement with the in vivo importance of histidine biosynthesis, the HisB inhibitor 3-amino-1,2,4-triazole reduced the virulence of the A. fumigatus wild type and histidine supplementation partially rescued virulence of the histidine-auxotrophic mutant in the wax moth model. Taken together, this study reveals limited histidine availability in diverse A. fumigatus host niches, a crucial role for histidine in metal homeostasis, and the histidine biosynthetic pathway as being an attractive target for development of novel antifungal therapy approaches.
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Affiliation(s)
- Anna-Maria Dietl
- a Division of Molecular Biology, Biocenter, Medical University of Innsbruck , Innsbruck , Austria
| | - Jorge Amich
- b IZKF Forschergruppe für Experimentelle Stammzelltransplantation, Medizinische Klinik und Poliklinik II & Universitäts-Kinderklinik , Würzburg , Germany
| | - Sixto Leal
- c Department of Ophthalmology and Visual Sciences , Case Western Reserve University , Cleveland , OH , USA
| | - Nicola Beckmann
- a Division of Molecular Biology, Biocenter, Medical University of Innsbruck , Innsbruck , Austria
| | - Ulrike Binder
- d Division of Hygiene & Medical Microbiology, Medical University of Innsbruck , Innsbruck , Austria
| | - Andreas Beilhack
- b IZKF Forschergruppe für Experimentelle Stammzelltransplantation, Medizinische Klinik und Poliklinik II & Universitäts-Kinderklinik , Würzburg , Germany
| | - Eric Pearlman
- c Department of Ophthalmology and Visual Sciences , Case Western Reserve University , Cleveland , OH , USA
| | - Hubertus Haas
- a Division of Molecular Biology, Biocenter, Medical University of Innsbruck , Innsbruck , Austria
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Cunden LS, Gaillard A, Nolan EM. Calcium Ions Tune the Zinc-Sequestering Properties and Antimicrobial Activity of Human S100A12. Chem Sci 2016; 7:1338-1348. [PMID: 26913170 PMCID: PMC4762610 DOI: 10.1039/c5sc03655k] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Accepted: 10/26/2015] [Indexed: 12/15/2022] Open
Abstract
Human S100A12 is a host-defense protein expressed and released by neutrophils that contributes to innate immunity. Apo S100A12 is a 21-kDa antiparallel homodimer that harbors two Ca(II)-binding EF-hand domains per subunit and exhibits two His3Asp motifs for chelating transition metal ions at the homodimer interface. In this work, we present results from metal-binding studies and microbiology assays designed to ascertain whether Ca(II) ions modulate the Zn(II)-binding properties of S100A12 and further evaluate the antimicrobial properties of this protein. Our metal depletion studies reveal that Ca(II) ions enhance the ability of S100A12 to sequester Zn(II) from microbial growth media. We report that human S100A12 has antifungal activity against Candida albicans, C. krusei, C. glabrata and C. tropicalis, all of which cause human disease. This antifungal activity is Ca(II)-dependent and requires the His3Asp metal-binding sites. We expand upon prior studies of the antibacterial activity of S100A12 and report Ca(II)-dependent and strain-selective behavior. S100A12 exhibited in vitro growth inhibitory activity against Listeria monocytogenes. In contrast, S100A12 had negligible effect on the growth of Escherichia coli K-12 and Pseudomonas aeruginosa PAO1. Loss of functional ZnuABC, a high-affinity Zn(II) import system, increased the susceptibility of E. coli and P. aeruginosa to S100A12, indicating that S100A12 deprives these mutant strains of Zn(II). To evaluate the Zn(II)-binding sites of S100A12 in solution, we present studies using Co(II) as a spectroscopic probe and chromophoric small-molecule chelators in Zn(II) competition titrations. We confirm that S100A12 binds Zn(II) with a 2:1 stoichiometry, and our data indicate sub-nanomolar affinity binding. Taken together, these data support a model whereby S100A12 uses Ca(II) ions to tune its Zn(II)-chelating properties and antimicrobial activity.
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Affiliation(s)
- Lisa S. Cunden
- Department of Chemistry , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , MA 02139 , USA . ; Fax: +1-617-324-0505 ; Tel: +1-617-452-2495
| | - Aleth Gaillard
- Department of Chemistry , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , MA 02139 , USA . ; Fax: +1-617-324-0505 ; Tel: +1-617-452-2495
| | - Elizabeth M. Nolan
- Department of Chemistry , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , MA 02139 , USA . ; Fax: +1-617-324-0505 ; Tel: +1-617-452-2495
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33
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Clark HL, Jhingran A, Sun Y, Vareechon C, de Jesus Carrion S, Skaar EP, Chazin WJ, Calera JA, Hohl TM, Pearlman E. Zinc and Manganese Chelation by Neutrophil S100A8/A9 (Calprotectin) Limits Extracellular Aspergillus fumigatus Hyphal Growth and Corneal Infection. THE JOURNAL OF IMMUNOLOGY 2015; 196:336-44. [PMID: 26582948 DOI: 10.4049/jimmunol.1502037] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 10/19/2015] [Indexed: 01/09/2023]
Abstract
Calprotectin, a heterodimer of S100A8 and S100A9, is an abundant neutrophil protein that possesses antimicrobial activity primarily because of its ability to chelate zinc and manganese. In the current study, we showed that neutrophils from calprotectin-deficient S100A9(-/-) mice have an impaired ability to inhibit Aspergillus fumigatus hyphal growth in vitro and in infected corneas in a murine model of fungal keratitis; however, the ability to inhibit hyphal growth was restored in S100A9(-/-) mice by injecting recombinant calprotectin. Furthermore, using recombinant calprotectin with mutations in either the Zn and Mn binding sites or the Mn binding site alone, we show that both zinc and manganese binding are necessary for calprotectin's antihyphal activity. In contrast to hyphae, we found no role for neutrophil calprotectin in uptake or killing of intracellular A. fumigatus conidia either in vitro or in a murine model of pulmonary aspergillosis. We also found that an A. fumigatus ∆zafA mutant, which demonstrates deficient zinc transport, exhibits impaired growth in infected corneas and following incubation with neutrophils or calprotectin in vitro as compared with wild-type. Collectively, these studies demonstrate a novel stage-specific susceptibility of A. fumigatus to zinc and manganese chelation by neutrophil-derived calprotectin.
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Affiliation(s)
- Heather L Clark
- Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH 44106; Department of Ophthalmology, University of California, Irvine, Irvine, CA 92697; Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA 92697
| | - Anupam Jhingran
- Infectious Disease Service, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY 10065
| | - Yan Sun
- Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH 44106
| | - Chairut Vareechon
- Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH 44106
| | - Steven de Jesus Carrion
- Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH 44106
| | - Eric P Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232; Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN 37212
| | - Walter J Chazin
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232; Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, TN 37232; and
| | - José Antonio Calera
- Instituto de Biología Funcional y Genómica, Centro Mixto del Consejo Superior de Investigaciones Científicas y Universidad de Salamanca, 37002 Salamanca, Spain
| | - Tobias M Hohl
- Infectious Disease Service, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY 10065
| | - Eric Pearlman
- Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH 44106; Department of Ophthalmology, University of California, Irvine, Irvine, CA 92697; Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA 92697;
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Finnegan S, Percival SL. EDTA: An Antimicrobial and Antibiofilm Agent for Use in Wound Care. Adv Wound Care (New Rochelle) 2015; 4:415-421. [PMID: 26155384 DOI: 10.1089/wound.2014.0577] [Citation(s) in RCA: 139] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 09/10/2014] [Indexed: 11/12/2022] Open
Abstract
Significance: Methods employed for preventing and eliminating biofilms are limited in their efficacy on mature biofilms. Despite this a number of antibiofilm formulations and technologies incorporating ethylenediaminetetraacetic acid (EDTA) have demonstrated efficacy on in vitro biofilms. The aim of this article is to critically review EDTA, in particular tetrasodium EDTA (tEDTA), as a potential antimicrobial and antibiofilm agent, in its own right, for use in skin and wound care. EDTA's synergism with other antimicrobials and surfactants will also be discussed. Recent Advances: The use of EDTA as a potentiating and sensitizing agent is not a new concept. However, currently the application of EDTA, specifically tEDTA as a stand-alone antimicrobial and antibiofilm agent, and its synergistic combination with other antimicrobials to make a "multi-pronged" approach to biofilm control is being explored. Critical Issues: As pathogenic biofilms in the wound increase infection risk, tEDTA could be considered as a potential "stand-alone" antimicrobial/antibiofilm agent or in combination with other antimicrobials, for use in both the prevention and treatment of biofilms found within abiotic (the wound dressing) and biotic (wound bed) environments. The ability of EDTA to chelate and potentiate the cell walls of bacteria and destabilize biofilms by sequestering calcium, magnesium, zinc, and iron makes it a suitable agent for use in the management of biofilms. Future Direction: tEDTA's excellent inherent antimicrobial and antibiofilm activity and proven synergistic and permeating ability results in a very beneficial agent, which could be used for the development of future antibiofilm technologies.
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Affiliation(s)
- Simon Finnegan
- Department of Chemistry, University of Sheffield, Sheffield, United Kingdom
| | - Steven L. Percival
- Surface Science Research Centre, University of Liverpool, Liverpool, United Kingdom
- Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
- Scapa Healthcare, Manchester, United Kingdom
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35
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Schneider RDO, Diehl C, Dos Santos FM, Piffer AC, Garcia AWA, Kulmann MIR, Schrank A, Kmetzsch L, Vainstein MH, Staats CC. Effects of zinc transporters on Cryptococcus gattii virulence. Sci Rep 2015; 5:10104. [PMID: 25951314 PMCID: PMC4423424 DOI: 10.1038/srep10104] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 03/30/2015] [Indexed: 12/13/2022] Open
Abstract
Zinc is an essential nutrient for all living organisms because it is a co-factor of several important proteins. Furthermore, zinc may play an essential role in the infectiousness of microorganisms. Previously, we determined that functional zinc metabolism is associated with Cryptococcus gattii virulence. Here, we characterized the ZIP zinc transporters in this human pathogen. Transcriptional profiling revealed that zinc levels regulated the expression of the ZIP1, ZIP2 and ZIP3 genes, although only the C. gattii zinc transporter Zip1 was required for yeast growth under zinc-limiting conditions. To associate zinc uptake defects with virulence, the most studied cryptococcal virulence factors (i.e., capsule, melanin and growth at 37 °C) were assessed in ZIP mutant strains; however, no differences were detected in these classical virulence-associated traits among the mutant and WT strains. Interestingly, higher levels of reactive oxygen species were detected in the zip1Δ and in the zip1Δ zip2Δ double mutants. In line with these phenotypic alterations, the zip1Δ zip2Δ double mutant displayed attenuated virulence in a murine model of cryptococcosis. Together, these results indicate that adequate zinc uptake is necessary for cryptococcal fitness and virulence.
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Affiliation(s)
| | | | | | | | | | | | - Augusto Schrank
- Centro de Biotecnologia.,Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 43421, Caixa Postal 15005, Porto Alegre, RS 91501-970, Brazil
| | - Lívia Kmetzsch
- Centro de Biotecnologia.,Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 43421, Caixa Postal 15005, Porto Alegre, RS 91501-970, Brazil
| | - Marilene Henning Vainstein
- Centro de Biotecnologia.,Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 43421, Caixa Postal 15005, Porto Alegre, RS 91501-970, Brazil
| | - Charley C Staats
- Centro de Biotecnologia.,Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 43421, Caixa Postal 15005, Porto Alegre, RS 91501-970, Brazil
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Vicentefranqueira R, Amich J, Laskaris P, Ibrahim-Granet O, Latgé JP, Toledo H, Leal F, Calera JA. Targeting zinc homeostasis to combat Aspergillus fumigatus infections. Front Microbiol 2015; 6:160. [PMID: 25774155 PMCID: PMC4343018 DOI: 10.3389/fmicb.2015.00160] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 02/11/2015] [Indexed: 11/13/2022] Open
Abstract
Aspergillus fumigatus is able to invade and grow in the lungs of immunosuppressed individuals and causes invasive pulmonary aspergillosis. The concentration of free zinc in living tissues is much lower than that required for optimal fungal growth in vitro because most of it is tightly bound to proteins. To obtain efficiently zinc from a living host A. fumigatus uses the zinc transporters ZrfA, ZrfB, and ZrfC. The ZafA transcriptional regulator induces the expression of all these transporters and is essential for virulence. Thus, ZafA could be targeted therapeutically to inhibit fungal growth. The ZrfC transporter plays the major role in zinc acquisition from the host whereas ZrfA and ZrfB rather have a supplementary role to that of ZrfC. In addition, only ZrfC enables A. fumigatus to overcome the inhibitory effect of calprotectin, which is an antimicrobial Zn/Mn-chelating protein synthesized and released by neutrophils within the fungal abscesses of immunosuppressed non-leucopenic animals. Hence, fungal survival in these animals would be undermined upon blocking therapeutically the function of ZrfC. Therefore, both ZafA and ZrfC have emerged as promising targets for the discovery of new antifungals to treat Aspergillus infections.
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Affiliation(s)
- Rocío Vicentefranqueira
- Instituto de Biología Funcional y Genómica, Centro Mixto del Consejo Superior de Investigaciones Científicas y Universidad de Salamanca , Salamanca, Spain ; Departamento de Microbiología y Genética, Universidad de Salamanca , Salamanca, Spain
| | - Jorge Amich
- Instituto de Biología Funcional y Genómica, Centro Mixto del Consejo Superior de Investigaciones Científicas y Universidad de Salamanca , Salamanca, Spain ; Departamento de Microbiología y Genética, Universidad de Salamanca , Salamanca, Spain
| | - Paris Laskaris
- Unité de Recherche Cytokines and Inflammation, Institut Pasteur , Paris, France
| | | | - Jean P Latgé
- Unité des Aspergillus, Institut Pasteur , Paris, France
| | - Héctor Toledo
- Instituto de Biología Funcional y Genómica, Centro Mixto del Consejo Superior de Investigaciones Científicas y Universidad de Salamanca , Salamanca, Spain ; Departamento de Microbiología y Genética, Universidad de Salamanca , Salamanca, Spain
| | - Fernando Leal
- Instituto de Biología Funcional y Genómica, Centro Mixto del Consejo Superior de Investigaciones Científicas y Universidad de Salamanca , Salamanca, Spain ; Departamento de Microbiología y Genética, Universidad de Salamanca , Salamanca, Spain
| | - José A Calera
- Instituto de Biología Funcional y Genómica, Centro Mixto del Consejo Superior de Investigaciones Científicas y Universidad de Salamanca , Salamanca, Spain ; Departamento de Microbiología y Genética, Universidad de Salamanca , Salamanca, Spain
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