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Wang G, Chen B, Zhang X, Du G, Han G, Liu J, Peng Y. The basic leucine zipper domain (bZIP) transcription factor BbYap1 promotes evasion of host humoral immunity and regulates lipid homeostasis contributing to fungal virulence in Beauveria bassiana. mSphere 2024; 9:e0035124. [PMID: 38926907 PMCID: PMC11288043 DOI: 10.1128/msphere.00351-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Accepted: 06/11/2024] [Indexed: 06/28/2024] Open
Abstract
Basic leucine zipper domain transcription factors (TFs), of which yeast activator protein (Yap) is a significant class, are crucial for the development of sclerotia, the stress response, vegetative growth, and spore adhesion. Nevertheless, nothing is known about how Yap TFs contribute to the pathogenicity of entomopathogenic fungus. In this work, Beauveria bassiana was used to identify and knock out the yeast gene BbYap1, which is similar to Yap. The BbYap1 gene deletion has an impact on lipid homeostasis of B. bassiana; oleic acid, for example, dropped by 95.69%. The BbYap1 mutant exhibited much less virulence and vegetative development in comparison to the wild strain, while demonstrating a greater sensitivity to chemical stress. It is noteworthy that the physiological abnormalities brought on by BbYap1 deletion were largely repaired by the addition of exogenous oleic acid, as seen by the notable increase in insect survival in the blood cavity injection group. Following infection with the BbYap1 mutant, the host exhibits a considerable down-regulation of the expression of β-1,3-glucan recognition protein, gallerimycin, gloverin, and moricin-like protein genes. Likewise, the introduction of exogenous oleic acid markedly increased the host's expression of the aforementioned genes. In summary, BbYap1 regulates cellular enzyme lipid homeostasis and fungal virulence by eluding host humoral defense, which contributes to fungal chemical stress and vegetative development. IMPORTANCE Entomopathogenic fungi (EPF) offer an effective and eco-friendly alternative to curb insect populations in biocontrol strategy. When EPF enter the hemolymph of their host, they encounter a variety of stress reactions, such as immunological and oxidative stress. Basic leucine zipper domain transcription factors, of which yeast activator protein (Yap) is a significant class, have diverse biological functions related to metabolism, development, reproduction, conidiation, stress responses, and pathogenicity. This study demonstrates that BbYap1 of Beauveria bassiana regulates cellular enzyme lipid homeostasis and fungal virulence by eluding host humoral defense, which contributes to fungal chemical stress and vegetative development. These findings offer fresh perspectives for comprehending molecular roles of YAP in EPF.
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Affiliation(s)
- Guang Wang
- Yunnan State Key Laboratory of Conservation and Utilization of Biological Resources, Yunnan Agricultural University, College of Plant Protection, Kunming, China
| | - Bin Chen
- Yunnan State Key Laboratory of Conservation and Utilization of Biological Resources, Yunnan Agricultural University, College of Plant Protection, Kunming, China
| | - Xu Zhang
- Yunnan State Key Laboratory of Conservation and Utilization of Biological Resources, Yunnan Agricultural University, College of Plant Protection, Kunming, China
| | - Guangzu Du
- Yunnan State Key Laboratory of Conservation and Utilization of Biological Resources, Yunnan Agricultural University, College of Plant Protection, Kunming, China
| | - Guangyu Han
- Yunnan State Key Laboratory of Conservation and Utilization of Biological Resources, Yunnan Agricultural University, College of Plant Protection, Kunming, China
| | - Jing Liu
- Yunnan Key Laboratory of Potato Biology, School of Life Science, Yunnan Normal University, Kunming, China
| | - Yuejin Peng
- Yunnan State Key Laboratory of Conservation and Utilization of Biological Resources, Yunnan Agricultural University, College of Plant Protection, Kunming, China
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Bákány B, Antal R, Szentesi P, Emri T, Leiter É, Csernoch L, Keller NP, Pócsi I, Dienes B. The bZIP-type transcription factors NapA and RsmA modulate the volumetric ratio and the relative superoxide ratio of mitochondria in Aspergillus nidulans. Biol Futur 2023; 74:337-346. [PMID: 37814124 DOI: 10.1007/s42977-023-00184-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 09/24/2023] [Indexed: 10/11/2023]
Abstract
Basic leucine zipper (bZIP) transcription factors are crucial components of differentiation, cellular homeostasis and the environmental stress defense of eukaryotes. In this work, we further studied the consequence of gene deletion and overexpression of two bZIP transcription factors, NapA and RsmA, on superoxide production, mitochondrial morphology and hyphal diameter of Aspergillus nidulans. We have found that reactive oxygen species production was influenced by both gene deletion and overexpression of napA under tert-butylhydroperoxide (tBOOH) elicited oxidative stress. Furthermore, gene expression of napA negatively correlated with mitochondrial volumetric ratio as well as sterigmatocystin production of A. nidulans. High rsmA expression was accompanied with elevated relative superoxide ratio in the second hyphal compartment. A negative correlation between the expression of rsmA and catalase enzyme activity or mitochondrial volumetric ratio was also confirmed by statistical analysis. Hyphal diameter was independent on either rsmA and napA expression as well as 0.2 mM tBOOH treatment.
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Affiliation(s)
- Bernadett Bákány
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- Doctoral School of Molecular Medicine, University of Debrecen, Debrecen, Hungary
- Institute of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Réka Antal
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Péter Szentesi
- Institute of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- ELRN-UD Cell Physiology Research Group, Debrecen, Hungary
| | - Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- ELRN-UD Fungal Stress Biology Research Group, Debrecen, Hungary
| | - Éva Leiter
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary.
- ELRN-UD Fungal Stress Biology Research Group, Debrecen, Hungary.
| | - László Csernoch
- Institute of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- ELRN-UD Cell Physiology Research Group, Debrecen, Hungary
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, USA
- Department of Plant Pathology, University of Wisconsin, Madison, USA
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- ELRN-UD Fungal Stress Biology Research Group, Debrecen, Hungary
| | - Beatrix Dienes
- Institute of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- ELRN-UD Cell Physiology Research Group, Debrecen, Hungary
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Hokken MWJ, Coolen JPM, Steenbreker H, Zoll J, Baltussen TJH, Verweij PE, Melchers WJG. The Transcriptome Response to Azole Compounds in Aspergillus fumigatus Shows Differential Gene Expression across Pathways Essential for Azole Resistance and Cell Survival. J Fungi (Basel) 2023; 9:807. [PMID: 37623579 PMCID: PMC10455693 DOI: 10.3390/jof9080807] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/19/2023] [Accepted: 07/27/2023] [Indexed: 08/26/2023] Open
Abstract
The opportunistic pathogen Aspergillus fumigatus is found on all continents and thrives in soil and agricultural environments. Its ability to readily adapt to novel environments and to produce billions of spores led to the spread of azole-resistant A. fumigatus across the globe, posing a threat to many immunocompromised patients, including critically ill patients with severe influenza or COVID-19. In our study, we sought to compare the adaptational response to azoles from A. fumigatus isolates that differ in azole susceptibility and genetic background. To gain more insight into how short-term adaptation to stressful azole compounds is managed through gene expression, we conducted an RNA-sequencing study on the response of A. fumigatus to itraconazole and the newest clinically approved azole, isavuconazole. We observed many similarities in ergosterol biosynthesis up-regulation across isolates, with the exception of the pan-azole-resistant isolate, which showed very little differential regulation in comparison to other isolates. Additionally, we found differential regulation of membrane efflux transporters, secondary metabolites, iron metabolism, and various stress response and cell signaling mechanisms.
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Affiliation(s)
- Margriet W. J. Hokken
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands (T.J.H.B.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6500 HB Nijmegen, The Netherlands
| | - Jordy P. M. Coolen
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands (T.J.H.B.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6500 HB Nijmegen, The Netherlands
| | - Hilbert Steenbreker
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands (T.J.H.B.)
| | - Jan Zoll
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands (T.J.H.B.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6500 HB Nijmegen, The Netherlands
| | - Tim J. H. Baltussen
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands (T.J.H.B.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6500 HB Nijmegen, The Netherlands
| | - Paul E. Verweij
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands (T.J.H.B.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6500 HB Nijmegen, The Netherlands
| | - Willem J. G. Melchers
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands (T.J.H.B.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6500 HB Nijmegen, The Netherlands
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Yaakoub H, Mina S, Calenda A, Bouchara JP, Papon N. Oxidative stress response pathways in fungi. Cell Mol Life Sci 2022; 79:333. [PMID: 35648225 PMCID: PMC11071803 DOI: 10.1007/s00018-022-04353-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 04/21/2022] [Accepted: 05/05/2022] [Indexed: 11/03/2022]
Abstract
Fungal response to any stress is intricate, specific, and multilayered, though it employs only a few evolutionarily conserved regulators. This comes with the assumption that one regulator operates more than one stress-specific response. Although the assumption holds true, the current understanding of molecular mechanisms that drive response specificity and adequacy remains rudimentary. Deciphering the response of fungi to oxidative stress may help fill those knowledge gaps since it is one of the most encountered stress types in any kind of fungal niche. Data have been accumulating on the roles of the HOG pathway and Yap1- and Skn7-related pathways in mounting distinct and robust responses in fungi upon exposure to oxidative stress. Herein, we review recent and most relevant studies reporting the contribution of each of these pathways in response to oxidative stress in pathogenic and opportunistic fungi after giving a paralleled overview in two divergent models, the budding and fission yeasts. With the concept of stress-specific response and the importance of reactive oxygen species in fungal development, we first present a preface on the expanding domain of redox biology and oxidative stress.
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Affiliation(s)
- Hajar Yaakoub
- Univ Angers, Univ Brest, IRF, SFR ICAT, 49000, Angers, France
| | - Sara Mina
- Department of Medical Laboratory Sciences, Faculty of Health Sciences, Beirut Arab University, Beirut, Lebanon
| | | | | | - Nicolas Papon
- Univ Angers, Univ Brest, IRF, SFR ICAT, 49000, Angers, France.
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The bZIP Ap1 transcription factor is a negative regulator of virulence attributes of the anthropophilic dermatophyte Trichophyton rubrum. CURRENT RESEARCH IN MICROBIAL SCIENCES 2022; 3:100132. [PMID: 35909615 PMCID: PMC9325736 DOI: 10.1016/j.crmicr.2022.100132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 04/02/2022] [Accepted: 04/08/2022] [Indexed: 11/24/2022] Open
Abstract
The ap1 gene negatively regulates virulence traits in Trichophyton rubrum. Ap1 regulates T. rubrum growth in keratin, playing a vital role in nail infection. Ap1 may contribute to the chronicity of onychomycosis.
Trichophyton rubrum is a fungus that causes chronic skin and nail infections in healthy individuals and immunocompromised patients. During infection, T. rubrum invades host cutaneous tissues by adapting to the acidic pH and the innate immune response of the host. Several genes are upregulated during the growth of T. rubrum in substrates found in human tissue, including the ap1 gene, which codes for the transcription factor Ap1. Here, we generated a null mutant strain by deleting the T. rubrum ap1 gene and performed a functional analysis of this gene. Our results showed that the Δap1mutant increased its growth in nail fragments and co-cultures with keratinocytes compared to the wild type. Furthermore, the mutant displayed hyperpigmentation, thickening of the conidia cell wall, increased conidia susceptibility to calcofluor-white compared to the wild type, and loss of control of the keratinolytic activity. Although the ap1 gene was upregulated during exposure to the antifungal drugs amphotericin B, nystatin, and terbinafine, its deletion did not alter the fungal susceptibility to these drugs, revealing the role of the ap1 gene in the physiological response to the stress caused by these drugs, but not in their resistance. Moreover, ap1 was also involved in the oxidative stress response caused by menadione, but not paraquat or hydrogen peroxide. These findings indicate that the ap1 gene plays a role in the negative control of virulence-related attributes and may contribute to the chronicity of nail infection caused by T. rubrum.
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de Castro PA, Colabardini AC, Moraes M, Horta MAC, Knowles SL, Raja HA, Oberlies NH, Koyama Y, Ogawa M, Gomi K, Steenwyk JL, Rokas A, Gonçales RA, Duarte-Oliveira C, Carvalho A, Ries LNA, Goldman GH. Regulation of gliotoxin biosynthesis and protection in Aspergillus species. PLoS Genet 2022; 18:e1009965. [PMID: 35041649 PMCID: PMC8797188 DOI: 10.1371/journal.pgen.1009965] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/28/2022] [Accepted: 01/04/2022] [Indexed: 02/07/2023] Open
Abstract
Aspergillus fumigatus causes a range of human and animal diseases collectively known as aspergillosis. A. fumigatus possesses and expresses a range of genetic determinants of virulence, which facilitate colonisation and disease progression, including the secretion of mycotoxins. Gliotoxin (GT) is the best studied A. fumigatus mycotoxin with a wide range of known toxic effects that impair human immune cell function. GT is also highly toxic to A. fumigatus and this fungus has evolved self-protection mechanisms that include (i) the GT efflux pump GliA, (ii) the GT neutralising enzyme GliT, and (iii) the negative regulation of GT biosynthesis by the bis-thiomethyltransferase GtmA. The transcription factor (TF) RglT is the main regulator of GliT and this GT protection mechanism also occurs in the non-GT producing fungus A. nidulans. However, the A. nidulans genome does not encode GtmA and GliA. This work aimed at analysing the transcriptional response to exogenous GT in A. fumigatus and A. nidulans, two distantly related Aspergillus species, and to identify additional components required for GT protection. RNA-sequencing shows a highly different transcriptional response to exogenous GT with the RglT-dependent regulon also significantly differing between A. fumigatus and A. nidulans. However, we were able to observe homologs whose expression pattern was similar in both species (43 RglT-independent and 11 RglT-dependent). Based on this approach, we identified a novel RglT-dependent methyltranferase, MtrA, involved in GT protection. Taking into consideration the occurrence of RglT-independent modulated genes, we screened an A. fumigatus deletion library of 484 transcription factors (TFs) for sensitivity to GT and identified 15 TFs important for GT self-protection. Of these, the TF KojR, which is essential for kojic acid biosynthesis in Aspergillus oryzae, was also essential for virulence and GT biosynthesis in A. fumigatus, and for GT protection in A. fumigatus, A. nidulans, and A. oryzae. KojR regulates rglT, gliT, gliJ expression and sulfur metabolism in Aspergillus species. Together, this study identified conserved components required for GT protection in Aspergillus species. A. fumigatus secretes mycotoxins that are essential for its virulence and pathogenicity. Gliotoxin (GT) is a sulfur-containing mycotoxin, which is known to impair several aspects of the human immune response. GT is also toxic to different fungal species, which have evolved several GT protection strategies. To further decipher these responses, we used transcriptional profiling aiming to compare the response to GT in the GT producer A. fumigatus and the GT non-producer A. nidulans. This analysis allowed us to identify additional genes with a potential role in GT protection. We also identified 15 transcription factors (TFs) encoded in the A. fumigatus genome that are important for conferring resistance to exogenous gliotoxin. One of these TFs, KojR, which is essential for A. oryzae kojic acid production, is also important for virulence in A. fumigatus and GT protection in A. fumigatus, A. nidulans and A. oryzae. KojR regulates the expression of genes important for gliotoxin biosynthesis and protection, and sulfur metabolism. Together, this work identified conserved components required for gliotoxin protection in Aspergillus species.
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Affiliation(s)
- Patrícia Alves de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Ana Cristina Colabardini
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Maísa Moraes
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | | | - Sonja L. Knowles
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina United States of America
| | - Huzefa A. Raja
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina United States of America
| | - Nicholas H. Oberlies
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina United States of America
| | - Yasuji Koyama
- Noda Institute for Scientific Research, 338 Noda, Chiba, Japan
| | - Masahiro Ogawa
- Noda Institute for Scientific Research, 338 Noda, Chiba, Japan
| | - Katsuya Gomi
- Department of Bioindustrial Informatics and Genomics, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Jacob L. Steenwyk
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Relber A. Gonçales
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B’s—PT Government Associate Laboratory, Guimarães/Braga, Portugal
| | - Cláudio Duarte-Oliveira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B’s—PT Government Associate Laboratory, Guimarães/Braga, Portugal
| | - Agostinho Carvalho
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B’s—PT Government Associate Laboratory, Guimarães/Braga, Portugal
| | - Laure N. A. Ries
- MRC Centre for Medical Mycology at the University of Exeter, Geoffrey Pope Building, Exeter, United Kingdom
- * E-mail: (LNAR); (GHG)
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
- * E-mail: (LNAR); (GHG)
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The OxrA Protein of Aspergillus fumigatus Is Required for the Oxidative Stress Response and Fungal Pathogenesis. Appl Environ Microbiol 2021; 87:e0112021. [PMID: 34524893 DOI: 10.1128/aem.01120-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An efficient reactive oxygen species (ROS) detoxification system is vital for the survival of the pathogenic fungus Aspergillus fumigatus within the host high-ROS environment of the host. Therefore, identifying and targeting factors essential for oxidative stress response is one approach to developing novel treatments for fungal infections. The oxidation resistance 1 (Oxr1) protein is essential for protection against oxidative stress in mammals, but its functions in pathogenic fungi remain unknown. The present study aimed to characterize the role of an Oxr1 homolog in A. fumigatus. The results indicated that the OxrA protein plays an important role in oxidative stress resistance by regulating the catalase function in A. fumigatus, and overexpression of catalase can rescue the phenotype associated with OxrA deficiency. Importantly, the deficiency of oxrA decreased the virulence of A. fumigatus and altered the host immune response. Using the Aspergillus-induced lung infection model, we demonstrated that the ΔoxrA mutant strain induced less tissue damage along with decreased levels of lactate dehydrogenase (LDH) and albumin release. Additionally, the ΔoxrA mutant caused inflammation at a lower degree, along with a markedly reduced influx of neutrophils to the lungs and a decreased secretion of cytokine usually associated with recruitment of neutrophils in mice. These results characterize the role of OxrA in A. fumigatus as a core regulator of oxidative stress resistance and fungal pathogenesis. IMPORTANCE Knowledge of ROS detoxification in fungal pathogens is useful in the design of new antifungal drugs and could aid in the study of oxidative stress resistance mechanisms. In this study, we demonstrate that OxrA protein localizes to the mitochondria and functions to protect against oxidative damage. We demonstrate that OxrA contributes to oxidative stress resistance by regulating catalase function, and overexpression of catalase (CatA or CatB) can rescue the phenotype that is associated with OxrA deficiency. Remarkably, a loss of OxrA attenuated the fungal virulence in a mouse model of invasive pulmonary aspergillosis and altered the host immune response. Therefore, our finding indicates that inhibition of OxrA might be an effective approach for alleviating A. fumigatus infection. The present study is, to the best of our knowledge, a pioneer in reporting the vital role of Oxr1 protein in pathogenic fungi.
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Bákány B, Yin WB, Dienes B, Nagy T, Leiter É, Emri T, Keller NP, Pócsi I. Study on the bZIP-Type Transcription Factors NapA and RsmA in the Regulation of Intracellular Reactive Species Levels and Sterigmatocystin Production of Aspergillus nidulans. Int J Mol Sci 2021; 22:11577. [PMID: 34769008 PMCID: PMC8583795 DOI: 10.3390/ijms222111577] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/20/2021] [Accepted: 10/22/2021] [Indexed: 11/16/2022] Open
Abstract
Basic leucine zipper (bZIP) transcription factors play a crucial role in the environmental stress response of eukaryotes. In this work, we studied the effect of gene manipulations, including both deletions and overexpressions, of two selected bZIP transcription factors, NapA and RsmA, in the oxidative stress response and sterigmatocystin production of Aspergillus nidulans. We found that NapA was important in the oxidative stress response by negatively regulating intracellular reactive species production and positively regulating catalase activities, whereas RsmA slightly negatively regulated catalase activities. Concerning sterigmatocystin production, the highest concentration was measured in the ΔrsmAΔnapA double deletion mutant, but elevated sterigmatocystin production was also found in the OErsmA OEnapA strain. Our results indicate that NapA influences sterigmatocystin production via regulating reactive species level whereas RsmA modulates toxin production independently of the redox regulation of the cells.
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Affiliation(s)
- Bernadett Bákány
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary; (B.B.); (T.E.); (I.P.)
- Doctoral School of Molecular Medicine, University of Debrecen, H-4010 Debrecen, Hungary
- Institute of Physiology, Faculty of Medicine, University of Debrecen, H-4010 Debrecen, Hungary;
| | - Wen-Bing Yin
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China;
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA;
| | - Beatrix Dienes
- Institute of Physiology, Faculty of Medicine, University of Debrecen, H-4010 Debrecen, Hungary;
| | - Tibor Nagy
- Department of Applied Chemistry, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary;
| | - Éva Leiter
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary; (B.B.); (T.E.); (I.P.)
| | - Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary; (B.B.); (T.E.); (I.P.)
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA;
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706, USA
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary; (B.B.); (T.E.); (I.P.)
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Ross BS, Lofgren LA, Ashare A, Stajich JE, Cramer RA. Aspergillus fumigatus In-Host HOG Pathway Mutation for Cystic Fibrosis Lung Microenvironment Persistence. mBio 2021; 12:e0215321. [PMID: 34465017 PMCID: PMC8406193 DOI: 10.1128/mbio.02153-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 07/26/2021] [Indexed: 11/24/2022] Open
Abstract
The prevalence of Aspergillus fumigatus colonization in individuals with cystic fibrosis (CF) and subsequent fungal persistence in the lung is increasingly recognized. However, there is no consensus for clinical management of A. fumigatus in CF individuals, due largely to uncertainty surrounding A. fumigatus CF pathogenesis and virulence mechanisms. To address this gap in knowledge, a longitudinal series of A. fumigatus isolates from an individual with CF were collected over 4.5 years. Isolate genotypes were defined with whole-genome sequencing that revealed both transitory and persistent A. fumigatus in the lung. Persistent lineage isolates grew most readily in a low-oxygen culture environment, and conidia were more sensitive to oxidative stress-inducing conditions than those from nonpersistent isolates. Closely related persistent isolates harbored a unique allele of the high-osmolarity glycerol (HOG) pathway mitogen-activated protein kinase kinase, Pbs2 (pbs2C2). Data suggest this novel pbs2C2 allele arose in vivo and is necessary for the fungal response to osmotic stress in a low-oxygen environment through hyperactivation of the HOG (SakA) signaling pathway. Hyperactivation of the HOG pathway through pbs2C2 comes at the cost of decreased conidial stress resistance in the presence of atmospheric oxygen levels. These novel findings shed light on pathoadaptive mechanisms of A. fumigatus in CF, lay the foundation for identifying persistent A. fumigatus isolates that may require antifungal therapy, and highlight considerations for successful culture of persistent Aspergillus CF isolates. IMPORTANCE Aspergillus fumigatus infection causes a spectrum of clinical manifestations. For individuals with cystic fibrosis (CF), allergic bronchopulmonary aspergillosis (ABPA) is an established complication, but there is a growing appreciation for A. fumigatus airway persistence in CF disease progression. There currently is little consensus for clinical management of A. fumigatus long-term culture positivity in CF. A better understanding of A. fumigatus pathogenesis mechanisms in CF is expected to yield insights into when antifungal therapies are warranted. Here, a 4.5-year longitudinal collection of A. fumigatus isolates from a patient with CF identified a persistent lineage that harbors a unique allele of the Pbs2 mitogen-activated protein kinase kinase (MAPKK) necessary for unique CF-relevant stress phenotypes. Importantly for A. fumigatus CF patient diagnostics, this allele provides increased fitness under CF lung-like conditions at a cost of reduced in vitro growth under standard laboratory conditions. These data illustrate a molecular mechanism for A. fumigatus CF lung persistence with implications for diagnostics and antifungal therapy.
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Affiliation(s)
- Brandon S. Ross
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Lotus A. Lofgren
- Department of Microbiology and Plant Pathology, Institute for Integrative Genome Biology, University of California Riverside, Riverside, California, USA
| | - Alix Ashare
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
- Department of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Jason E. Stajich
- Department of Microbiology and Plant Pathology, Institute for Integrative Genome Biology, University of California Riverside, Riverside, California, USA
| | - Robert A. Cramer
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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The Copper Chaperone CcsA, Coupled with Superoxide Dismutase SodA, Mediates the Oxidative Stress Response in Aspergillus fumigatus. Appl Environ Microbiol 2021; 87:e0101321. [PMID: 34160279 DOI: 10.1128/aem.01013-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Superoxide dismutases (SODs) are important metalloenzymes that protect fungal pathogens against the toxic effects of reactive oxygen species (ROS) generated by host defense mechanisms during the infection process. The activation of Cu/Zn-SOD1 is found to be dependent on copper chaperone for SOD1 (Ccs1). However, the role of the Ccs1 ortholog in the human pathogen Aspergillus fumigatus and how these SODs coordinate to mediate oxidative stress response remain elusive. Here, we demonstrated that A. fumigatus CcsA, a Saccharomyces cerevisiae Ccs1 ortholog, is required for cells in response to oxidative response and the activation of Sod1. Deletion of ccsA resulted in increased ROS accumulation and enhanced sensitivity to oxidative stress due to the loss of SodA activity. Molecular characterization of CcsA revealed that the conserved CXC motif is required not only for the physical interaction with SodA but also for the oxidative stress adaption. Notably, addition of Mn2+ or overexpression of cytoplasmic Mn-SodC could rescue the defects of the ccsA or sodA deletion mutant, indicating the important role of Mn2+ and Mn-SodC in ROS detoxification; however, deletion of the CcsA-SodA complex could not affect A. fumigatus virulence. Collectively, our findings demonstrate that CcsA functions as a Cu/Zn-Sod1 chaperone that participates in the adaptation to oxidative stress in A. fumigatus and provide a better understanding of the CcsA-SodA complex-mediated oxidative stress response in filamentous fungi. IMPORTANCE Reactive oxygen species (ROS) produced by phagocytes have been reported to participate in the killing of fungal pathogens. Superoxide dismutases (SODs) are considered to be the first line of defense against superoxide anions. Characterizing the regulatory mechanisms of SOD activation is important for understanding how fungi adapt to oxidative stress in hosts. Our findings demonstrated that CcsA functions as a SodA chaperone in A. fumigatus and that the conserved CXC motif within CcsA is required for its interaction with SodA and the CcsA-SodA-mediated oxidative response. These data may provide new insights into how fungal pathogens adapt to oxidative stress via the CcsA-SodA complex.
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11
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Abd El-Rahman GI, Behairy A, Elseddawy NM, Batiha GES, Hozzein WN, Khodeer DM, M. Abd-Elhakim Y. Saussurea lappa Ethanolic Extract Attenuates Triamcinolone Acetonide-Induced Pulmonary and Splenic Tissue Damage in Rats via Modulation of Oxidative Stress, Inflammation, and Apoptosis. Antioxidants (Basel) 2020; 9:antiox9050396. [PMID: 32397156 PMCID: PMC7278611 DOI: 10.3390/antiox9050396] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/26/2020] [Accepted: 04/27/2020] [Indexed: 12/12/2022] Open
Abstract
Background: In this era, worldwide interest has been directed towards using natural antioxidants to guard against drug side effects. Saussurea lappa is a famous medicinal plant with many biologically active compounds. Triamcinolone acetonide (TA) is an extensively used glucocorticoid. Hence, this study explored, for the first time, the possible beneficial effects of S. lappa ethanolic extract on TA-induced oxidative damage in the lung and spleen of rats. Methods: Five experimental groups were used: control group, S. lappa-treated group (600 mg/kg/day, orally), TA-treated group (40 mg/kg/twice/week I/P), S. lappa + TA co-treated group, and S. lappa/TA prophylactic group. Results: TA exposure significantly induced leukocytosis and neutrophilia. In addition, TA significantly reduced the levels of C-reactive protein, interleukin-12, tumor necrosis factor α, and immunoglobulins. Lung Caspase-3 overexpression and splenic CD8+ downregulation were also noted in the TA group. TA treatment significantly increased malondialdehyde concentration but reduced superoxide dismutase and glutathione peroxidase activities. S. lappa counteracted the TA oxidative and apoptotic effects. The best results were recorded in the prophylactic group. Conclusions:S. lappa has a remarkable protective effect via its anti-inflammatory, anti-apoptotic, and antioxidant capacity. Thus, it could be a candidate as a natural antioxidant to face glucocorticoid’s harmful side effects.
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Affiliation(s)
- Ghada I. Abd El-Rahman
- Department of Clinical Pathology, Faculty of Veterinary medicine, Zagazig University, Zagazig 44519, Egypt;
| | - Amany Behairy
- Department of Physiology, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44519, Egypt;
| | - Nora M. Elseddawy
- Department of Pathology, Faculty of Veterinary medicine, Zagazig University, Zagazig 44519 Egypt;
| | - Gaber El-Saber Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Damanhour 22511, AlBeheira, Egypt;
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-13, Inada-cho, Obihiro, Hokkaido 080-8555, Japan
| | - Wael N. Hozzein
- Bioproducts Research Chair, Zoology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia;
- Botany and Microbiology Department, Faculty of Science, Beni-Suef University, Beni-Suef 62511, Egypt
| | - Dina M. Khodeer
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt;
| | - Yasmina M. Abd-Elhakim
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44519, Egypt
- Correspondence:
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The bZIP Transcription Factor AflRsmA Regulates Aflatoxin B 1 Biosynthesis, Oxidative Stress Response and Sclerotium Formation in Aspergillus flavus. Toxins (Basel) 2020; 12:toxins12040271. [PMID: 32340099 PMCID: PMC7232220 DOI: 10.3390/toxins12040271] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/04/2020] [Accepted: 04/17/2020] [Indexed: 12/29/2022] Open
Abstract
Fungal secondary metabolites play important roles not only in fungal ecology but also in humans living as beneficial medicine or harmful toxins. In filamentous fungi, bZIP-type transcription factors (TFs) are associated with the proteins involved in oxidative stress response and secondary metabolism. In this study, a connection between a bZIP TF and oxidative stress induction of secondary metabolism is uncovered in an opportunistic pathogen Aspergillus flavus, which produces carcinogenic and mutagenic aflatoxins. The bZIP transcription factor AflRsmA was identified by a homology research of A. flavus genome with the bZIP protein RsmA, involved in secondary metabolites production in Aspergillusnidulans. The AflrsmA deletion strain (ΔAflrsmA) displayed less sensitivity to the oxidative reagents tert-Butyl hydroperoxide (tBOOH) in comparison with wild type (WT) and AflrsmA overexpression strain (AflrsmAOE), while AflrsmAOE strain increased sensitivity to the oxidative reagents menadione sodium bisulfite (MSB) compared to WT and ΔAflrsmA strains. Without oxidative treatment, aflatoxin B1 (AFB1) production of ΔAflrsmA strains was consistent with that of WT, but AflrsmAOE strain produced more AFB1 than WT; tBOOH and MSB treatment decreased AFB1 production of ΔAflrsmA compared to WT. Besides, relative to WT, ΔAflrsmA strain decreased sclerotia, while AflrsmAOE strain increased sclerotia. The decrease of AFB1 by ΔAflrsmA but increase of AFB1 by AflrsmAOE was on corn. Our results suggest that AFB1 biosynthesis is regulated by AflRsmA by oxidative stress pathways and provide insights into a possible function of AflRsmA in mediating AFB1 biosynthesis response host defense in pathogen A. flavus.
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Mendoza-Martínez AE, Cano-Domínguez N, Aguirre J. Yap1 homologs mediate more than the redox regulation of the antioxidant response in filamentous fungi. Fungal Biol 2019; 124:253-262. [PMID: 32389287 DOI: 10.1016/j.funbio.2019.04.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 04/02/2019] [Accepted: 04/03/2019] [Indexed: 10/27/2022]
Abstract
The regulation of gene expression in response to increased levels of reactive oxygen species (ROS) is a ubiquitous response in aerobic organisms. However, different organisms use different strategies to perceive and respond to high ROS levels. Yeast Yap1 is a paradigmatic example of a specific mechanism used by eukaryotic cells to link ROS sensing and gene regulation. The activation of this transcription factor by H2O2 is mediated by peroxiredoxins, which are widespread enzymes that use cysteine thiols to sense ROS, as well as to catalyze the reduction of peroxides to water. In filamentous fungi, Yap1 homologs and peroxiredoxins also are major regulators of the antioxidant response. However, Yap1 homologs are involved in a wider array of processes by regulating genes involved in nutrient assimilation, secondary metabolism, virulence and development. Such novel functions illustrate the divergent roles of ROS and other oxidizing compounds as important regulatory signaling molecules.
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Affiliation(s)
- Ariann E Mendoza-Martínez
- Departamento de Biología Celular y del Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, 04510 Ciudad de México, Mexico
| | - Nallely Cano-Domínguez
- Departamento de Biología Celular y del Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, 04510 Ciudad de México, Mexico
| | - Jesús Aguirre
- Departamento de Biología Celular y del Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, 04510 Ciudad de México, Mexico.
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14
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Simaan H, Lev S, Horwitz BA. Oxidant-Sensing Pathways in the Responses of Fungal Pathogens to Chemical Stress Signals. Front Microbiol 2019; 10:567. [PMID: 30941117 PMCID: PMC6433817 DOI: 10.3389/fmicb.2019.00567] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 03/05/2019] [Indexed: 12/04/2022] Open
Abstract
Host defenses expose fungal pathogens to oxidants and antimicrobial chemicals. The fungal cell employs conserved eukaryotic signaling pathways and dedicated transcription factors to program its response to these stresses. The oxidant-sensitive transcription factor of yeast, YAP1, and its orthologs in filamentous fungi, are central to tolerance to oxidative stress. The C-terminal domain of YAP1 contains cysteine residues that, under oxidizing conditions, form an intramolecular disulfide bridge locking the molecule in a conformation where the nuclear export sequence is masked. YAP1 accumulates in the nucleus, promoting transcription of genes that provide the cell with the ability to counteract oxidative stress. Chemicals including xenobiotics and plant signals can also promote YAP1 nuclearization in yeast and filamentous fungi. This could happen via direct or indirect oxidative stress, or by a different biochemical pathway. Plant phenolics are known antioxidants, yet they have been shown to elicit cellular responses that would usually be triggered to counter oxidant stress. Here we will discuss the evidence that YAP1 and MAPK pathways respond to phenolic compounds. Following this and other examples, we explore here how oxidative-stress sensing networks of fungi might have evolved to detect chemical stressors. Furthermore, we draw functional parallels between fungal YAP1 and mammalian Keap1-Nrf2 signaling systems.
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Affiliation(s)
- Hiba Simaan
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Sophie Lev
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Westmead, NSW, Australia
| | - Benjamin A Horwitz
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel
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15
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Abstract
Aspergillus fumigatus is the major filamentous fungal pathogen in humans. Infections associated with A. fumigatus are often treated with azole drugs, but resistance to these antifungal agents is increasing. Mortality from aspergillosis associated with azole-resistant fungi is extremely high. Previous work has identified transcriptional control of the azole drug target-encoding gene cyp51A as an important contributor to resistance in A. fumigatus. Here, we demonstrate that the transcription factor AtrR binds to a region in the cyp51A promoter that is associated with alleles of this gene conferring clinically important azole resistance. Using high-throughput genomic technologies, we also uncover a large suite of target genes controlled by AtrR. These data indicate that AtrR coordinately regulates many different processes involved in drug resistance, metabolism, and virulence. Our new understanding of AtrR function provides important new insight into the pathogenesis of A. fumigatus. Aspergillosis associated with azole-resistant Aspergillus fumigatus has a mortality rate that can approach 90% in certain patient populations. The best-understood avenue for azole resistance involves changes in the cyp51A gene that encodes the target of azole drugs, lanosterol α-14 demethylase. The most common azole resistance allele currently described is a linked change corresponding to a change in the coding sequence of cyp51A and a duplication of a 34-bp region in the promoter leading to a tandem repeat (TR). Our previous studies identified a positively acting transcription factor called AtrR that binds to the promoter of cyp51A as well as that of an important membrane transporter protein gene called abcG1. In this work, we characterize two different mutant alleles of atrR, either an overproducing or an epitope-tagged form, causing constitutive activation of this factor. Using an epitope-tagged allele of atrR for chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-seq), the genomic binding sites for AtrR were determined. Close to 900 genes were found to have an AtrR response element (ATRE) in their promoter regions. Transcriptome evaluation by RNA sequencing (RNA-seq) indicated that both alleles led to elevated transcription of a subset of target genes. An electrophoretic mobility shift assay and DNase I protection mapping localized the ATREs in both the abcG1 and cyp51A promoters. The ATRE in cyp51A was located within the 34-bp repeat element. Virulence in a murine model was compromised when AtrR was either deleted or overproduced, indicating that the proper dosage of this factor is key for pathogenesis.
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16
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Ukai Y, Kuroiwa M, Kurihara N, Naruse H, Homma T, Maki H, Naito A. Contributions of yap1 Mutation and Subsequent atrF Upregulation to Voriconazole Resistance in Aspergillus flavus. Antimicrob Agents Chemother 2018; 62:AAC.01216-18. [PMID: 30126960 PMCID: PMC6201102 DOI: 10.1128/aac.01216-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 08/08/2018] [Indexed: 01/16/2023] Open
Abstract
Aspergillus flavus is the second most significant pathogenic cause of invasive aspergillosis; however, its emergence risks and mechanisms of voriconazole (VRC) resistance have not yet been elucidated in detail. Here, we demonstrate that repeated exposure of A. flavus to subinhibitory concentrations of VRC in vitro causes the emergence of a VRC-resistant mutant with a novel resistance mechanism. The VRC-resistant mutant shows a MIC of 16 μg/ml for VRC and of 0.5 μg/ml for itraconazole (ITC). Whole-genome sequencing analysis showed that the mutant possesses a point mutation in yap1, which encodes a bZIP transcription factor working as the master regulator of the oxidative stress response, but no mutations in the cyp51 genes. This point mutation in yap1 caused alteration of Leu558 to Trp (Yap1Leu558Trp) in the putative nuclear export sequence in the carboxy-terminal cysteine-rich domain of Yap1. This Yap1Leu558Trp substitution was confirmed as being responsible for the VRC-resistant phenotype, but not for that of ITC, by the revertant to Yap1wild type with homologous gene replacement. Furthermore, Yap1Leu558Trp caused marked upregulation of the atrF ATP-binding cassette transporter, and the deletion of atrF restored susceptibility to VRC in A. flavus These findings provide new insights into VRC resistance mechanisms via a transcriptional factor mutation that is independent of the cyp51 gene mutation in A. flavus.
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Affiliation(s)
- Yuuta Ukai
- Drug Discovery & Disease Research Laboratory, Shionogi and Co., Ltd., Toyonaka, Osaka, Japan
| | - Miho Kuroiwa
- Drug Discovery & Disease Research Laboratory, Shionogi and Co., Ltd., Toyonaka, Osaka, Japan
| | - Naoko Kurihara
- Drug Discovery & Disease Research Laboratory, Shionogi and Co., Ltd., Toyonaka, Osaka, Japan
| | - Hiroki Naruse
- Drug Discovery & Disease Research Laboratory, Shionogi and Co., Ltd., Toyonaka, Osaka, Japan
| | - Tomoyuki Homma
- Drug Discovery & Disease Research Laboratory, Shionogi and Co., Ltd., Toyonaka, Osaka, Japan
| | - Hideki Maki
- Drug Discovery & Disease Research Laboratory, Shionogi and Co., Ltd., Toyonaka, Osaka, Japan
| | - Akira Naito
- Drug Discovery & Disease Research Laboratory, Shionogi and Co., Ltd., Toyonaka, Osaka, Japan
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17
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Qiao J, Song Y, Ling Z, Liu X, Fang H. ram1 gene, encoding a subunit of farnesyltransferase, contributes to growth, antifungal susceptibility to amphotericin B of Aspergillus fumigatus. Med Mycol 2018; 55:883-889. [PMID: 28159997 DOI: 10.1093/mmy/myx002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Accepted: 01/05/2017] [Indexed: 11/15/2022] Open
Abstract
Farnesylation, which is catalyzed by farnesyltransferase, is an important posttranslational process. The function of farnesyltransferase has been previously explored in Cryptococcus neoformans and Candida albicans. Aspergillus fumigatus is an important human opportunistic fungal pathogen in immunocompromised patients. Here we discover the role of the ram1 gene, encoding the β-subunit of farnesyltransferase in A. fumigatus, in the fungal growth and antifungal susceptibility. In this study the ram1 gene was disrupted using A. tumefaciens-mediated transformation. The morphology and radial growth of Δram1 were observed. Assays of disk diffusion and broth microdilution were used to determine the susceptibility of Δram1 mutant to commonly clinical used antifungals and the farnesyltransferase inhibitor manumycin A. Deletion of ram1 resulted in a reduced radial growth of A. fumigatus but did not affect the microscopic morphology. Δram1 showed increased susceptibility to the antifungal amphotericin B; however, its susceptibility to azoles and caspofungin was the same to that to the parental strain. Our data indicate that farnesyltransferase is a potential target for design new antifungal agents.
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Affiliation(s)
- Jianjun Qiao
- Department of Dermatology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Yan Song
- Kidney Disease Center, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Zongxin Ling
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Xia Liu
- Department of Intensive Care Unit, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Hong Fang
- Department of Dermatology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
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Bakti F, Sasse C, Heinekamp T, Pócsi I, Braus GH. Heavy Metal-Induced Expression of PcaA Provides Cadmium Tolerance to Aspergillus fumigatus and Supports Its Virulence in the Galleria mellonella Model. Front Microbiol 2018; 9:744. [PMID: 29706948 PMCID: PMC5909057 DOI: 10.3389/fmicb.2018.00744] [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: 12/14/2017] [Accepted: 03/29/2018] [Indexed: 11/23/2022] Open
Abstract
Most of the metal transporters in Aspergillus fumigatus are yet uncharacterized. Their role in fungal metabolism and virulence remains unclear. This paper describes the novel PIB-type cation ATPase PcaA, which links metal homeostasis and heavy metal tolerance in the opportunistic human pathogen A. fumigatus. The protein possesses conserved ATPase motif and shares 51% amino acid sequence identity with the Saccharomyces cerevisiae cadmium exporter Pca1p. A pcaA deletion, an overexpression and a gfp-pcaA complementation strain of A. fumigatus were constructed and their heavy metal susceptibilities were studied. The pcaA knock out strain showed drastically decreased cadmium tolerance, however, its growth was not affected by the exposure to high concentrations of copper, iron, zinc, or silver ions. Although the lack of PcaA had no effect on copper adaption, we demonstrated that not only cadmium but also copper ions are able to induce the transcription of pcaA in A. fumigatus wild type Af293. Similarly, cadmium and copper ions could induce the copper exporting ATPase crpA. These data imply a general response on the transcriptomic level to heavy metals in A. fumigatus through the induction of detoxification systems. Confocal microscopy of the gfp-pcaA complementation strain expressing functional GFP-PcaA supports the predicted membrane localization of PcaA. The GFP-PcaA fusion protein is located in the plasma membrane of A. fumigatus in the presence of cadmium ions. Virulence assays support a function of PcaA for virulence of A. fumigatus in the Galleria mellonella wax moth larvae model, which might be linked to the elimination of reactive oxygen species.
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Affiliation(s)
- Fruzsina Bakti
- Institute for Microbiology and Genetics, Department of Molecular Microbiology and Genetics, Goettingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany.,Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Christoph Sasse
- Institute for Microbiology and Genetics, Department of Molecular Microbiology and Genetics, Goettingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Thorsten Heinekamp
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Jena, Germany
| | - István Pócsi
- Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Gerhard H Braus
- Institute for Microbiology and Genetics, Department of Molecular Microbiology and Genetics, Goettingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany
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Jia X, Zhang X, Hu Y, Hu M, Tian S, Han X, Sun Y, Han L. Role of actin depolymerizing factor cofilin in Aspergillus fumigatus oxidative stress response and pathogenesis. Curr Genet 2017; 64:619-634. [PMID: 29170805 DOI: 10.1007/s00294-017-0777-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 10/28/2017] [Accepted: 10/31/2017] [Indexed: 12/13/2022]
Abstract
Aspergillus fumigatus is a major fungal pathogen that is responsible for approximately 90% of human aspergillosis. Cofilin is an actin depolymerizing factor that plays crucial roles in multiple cellular functions in many organisms. However, the functions of cofilin in A. fumigatus are still unknown. In this study, we constructed an A. fumigatus strain overexpressing cofilin (cofilin OE). The cofilin OE strain displayed a slightly different growth phenotype, significantly increased resistance against H2O2 and diamide, and increased activation of the high osmolarity glycerol pathway compared to the wild-type strain (WT). The cofilin OE strain internalized more efficiently into lung epithelial A549 cells, and induced increased transcription of inflammatory factors (MCP-1, TNF-α and IL-8) compared to WT. Cofilin overexpression also resulted in increased polysaccharides including β-1, 3-glucan and chitin, and increased transcription of genes related to oxidative stress responses and polysaccharide synthesis in A. fumigatus. However, the cofilin OE strain exhibited similar virulence to the wild-type strain in murine and Galleria mellonella infection models. These results demonstrated for the first time that cofilin, a regulator of actin cytoskeleton dynamics, might play a critical role in the regulation of oxidative stress responses and cell wall polysaccharide synthesis in A. fumigatus.
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Affiliation(s)
- Xiaodong Jia
- Institute for Disease Control and Prevention of PLA, Academy of Military Medical Sciences, 20# Dongda Str., 100071, Beijing, China
| | - Xi Zhang
- Institute for Disease Control and Prevention of PLA, Academy of Military Medical Sciences, 20# Dongda Str., 100071, Beijing, China
| | - Yingsong Hu
- Institute for Disease Control and Prevention of PLA, Academy of Military Medical Sciences, 20# Dongda Str., 100071, Beijing, China
| | - Mandong Hu
- Institute for Disease Control and Prevention of PLA, Academy of Military Medical Sciences, 20# Dongda Str., 100071, Beijing, China
| | - Shuguang Tian
- Institute for Disease Control and Prevention of PLA, Academy of Military Medical Sciences, 20# Dongda Str., 100071, Beijing, China
| | - Xuelin Han
- Institute for Disease Control and Prevention of PLA, Academy of Military Medical Sciences, 20# Dongda Str., 100071, Beijing, China
| | - Yansong Sun
- Institute for Disease Control and Prevention of PLA, Academy of Military Medical Sciences, 20# Dongda Str., 100071, Beijing, China.
| | - Li Han
- Institute for Disease Control and Prevention of PLA, Academy of Military Medical Sciences, 20# Dongda Str., 100071, Beijing, China.
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Desoubeaux G, Cray C. Rodent Models of Invasive Aspergillosis due to Aspergillus fumigatus: Still a Long Path toward Standardization. Front Microbiol 2017; 8:841. [PMID: 28559881 PMCID: PMC5432554 DOI: 10.3389/fmicb.2017.00841] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 04/24/2017] [Indexed: 01/09/2023] Open
Abstract
Invasive aspergillosis has been studied in laboratory by the means of plethora of distinct animal models. They were developed to address pathophysiology, therapy, diagnosis, or miscellaneous other concerns associated. However, there are great discrepancies regarding all the experimental variables of animal models, and a thorough focus on them is needed. This systematic review completed a comprehensive bibliographic analysis specifically-based on the technical features of rodent models infected with Aspergillus fumigatus. Out the 800 articles reviewed, it was shown that mice remained the preferred model (85.8% of the referenced reports), above rats (10.8%), and guinea pigs (3.8%). Three quarters of the models involved immunocompromised status, mainly by steroids (44.4%) and/or alkylating drugs (42.9%), but only 27.7% were reported to receive antibiotic prophylaxis to prevent from bacterial infection. Injection of spores (30.0%) and inhalation/deposition into respiratory airways (66.9%) were the most used routes for experimental inoculation. Overall, more than 230 distinct A. fumigatus strains were used in models. Of all the published studies, 18.4% did not mention usage of any diagnostic tool, like histopathology or mycological culture, to control correct implementation of the disease and to measure outcome. In light of these findings, a consensus discussion should be engaged to establish a minimum standardization, although this may not be consistently suitable for addressing all the specific aspects of invasive aspergillosis.
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Affiliation(s)
- Guillaume Desoubeaux
- Division of Comparative Pathology, Department of Pathology and Laboratory Medicine, Miller School of Medicine, University of MiamiMiami, FL, USA.,Service de Parasitologie-Mycologie-Médecine tropicale, Centre Hospitalier Universitaire de ToursTours, France.,Centre d'Etude des Pathologies Respiratoires (CEPR) Institut National de la Santé et de la Recherche Médicale U1100/Équipe 3, Université François-RabelaisTours, France
| | - Carolyn Cray
- Division of Comparative Pathology, Department of Pathology and Laboratory Medicine, Miller School of Medicine, University of MiamiMiami, FL, USA
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Mendoza-Martínez AE, Lara-Rojas F, Sánchez O, Aguirre J. NapA Mediates a Redox Regulation of the Antioxidant Response, Carbon Utilization and Development in Aspergillus nidulans. Front Microbiol 2017; 8:516. [PMID: 28424666 PMCID: PMC5371717 DOI: 10.3389/fmicb.2017.00516] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 03/13/2017] [Indexed: 01/27/2023] Open
Abstract
The redox-regulated transcription factors (TFs) of the bZIP AP1 family, such as yeast Yap1 and fission yeast Pap1, are activated by peroxiredoxin proteins (Prxs) to regulate the antioxidant response. Previously, Aspergillus nidulans mutants lacking the Yap1 ortholog NapA have been characterized as sensitive to H2O2 and menadione. Here we study NapA roles in relation to TFs SrrA and AtfA, also involved in oxidant detoxification, showing that these TFs play different roles in oxidative stress resistance, catalase gene regulation and development, during A. nidulans life cycle. We also uncover novel NapA roles in repression of sexual development, normal conidiation, conidial mRNA accumulation, and carbon utilization. The phenotypic characterization of ΔgpxA, ΔtpxA, and ΔtpxB single, double and triple peroxiredoxin mutants in wild type or ΔnapA backgrounds shows that none of these Prxs is required for NapA function in H2O2 and menadione resistance. However, these Prxs participate in a minor NapA-independent H2O2 resistance pathway and NapA and TpxA appear to regulate conidiation along the same route. Using transcriptomic analysis we show that during conidial development NapA-dependent gene expression pattern is different from canonical oxidative stress patterns. In the course of conidiation, NapA is required for regulation of at least 214 genes, including ethanol utilization genes alcR, alcA and aldA, and large sets of genes encoding proteins involved in transcriptional regulation, drug detoxification, carbohydrate utilization and secondary metabolism, comprising multiple oxidoreductases, membrane transporters and hydrolases. In agreement with this, ΔnapA mutants fail to grow or grow very poorly in ethanol, arabinose or fructose as sole carbon sources. Moreover, we show that NapA nuclear localization is induced not only by oxidative stress but also by growth in ethanol and by carbon starvation. Together with our previous work, these results show that SakA-AtfA, SrrA and NapA oxidative stress-sensing pathways regulate essential aspects of spore physiology (i.e., cell cycle arrest, dormancy, drug production and detoxification, and carbohydrate utilization).
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Affiliation(s)
- Ariann E Mendoza-Martínez
- Departamento de Biología Celular y del Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de MéxicoCoyoacán, Mexico
| | - Fernando Lara-Rojas
- Departamento de Biología Celular y del Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de MéxicoCoyoacán, Mexico
| | - Olivia Sánchez
- Departamento de Biología Celular y del Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de MéxicoCoyoacán, Mexico
| | - Jesús Aguirre
- Departamento de Biología Celular y del Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de MéxicoCoyoacán, Mexico
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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: 28] [Impact Index Per Article: 3.5] [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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Aspergillus fumigatus MADS-Box Transcription Factor rlmA Is Required for Regulation of the Cell Wall Integrity and Virulence. G3-GENES GENOMES GENETICS 2016; 6:2983-3002. [PMID: 27473315 PMCID: PMC5015955 DOI: 10.1534/g3.116.031112] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The Cell Wall Integrity (CWI) pathway is the primary signaling cascade that controls the de novo synthesis of the fungal cell wall, and in Saccharomyces cerevisiae this event is highly dependent on the RLM1 transcription factor. Here, we investigated the function of RlmA in the fungal pathogen Aspergillus fumigatus. We show that the ΔrlmA strain exhibits an altered cell wall organization in addition to defects related to vegetative growth and tolerance to cell wall-perturbing agents. A genetic analysis indicated that rlmA is positioned downstream of the pkcA and mpkA genes in the CWI pathway. As a consequence, rlmA loss-of-function leads to the altered expression of genes encoding cell wall-related proteins. RlmA positively regulates the phosphorylation of MpkA and is induced at both protein and transcriptional levels during cell wall stress. The rlmA was also involved in tolerance to oxidative damage and transcriptional regulation of genes related to oxidative stress adaptation. Moreover, the ΔrlmA strain had attenuated virulence in a neutropenic murine model of invasive pulmonary aspergillosis. Our results suggest that RlmA functions as a transcription factor in the A. fumigatus CWI pathway, acting downstream of PkcA-MpkA signaling and contributing to the virulence of this fungus.
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Meneau I, Coste AT, Sanglard D. Identification ofAspergillus fumigatusmultidrug transporter genes and their potential involvement in antifungal resistance. Med Mycol 2016; 54:616-27. [DOI: 10.1093/mmy/myw005] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 01/13/2016] [Indexed: 01/11/2023] Open
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25
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Wang X, Wu F, Liu L, Liu X, Che Y, Keller NP, Guo L, Yin WB. The bZIP transcription factor PfZipA regulates secondary metabolism and oxidative stress response in the plant endophytic fungus Pestalotiopsis fici. Fungal Genet Biol 2015; 81:221-8. [DOI: 10.1016/j.fgb.2015.03.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 03/29/2015] [Accepted: 03/30/2015] [Indexed: 12/27/2022]
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26
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Brandon M, Howard B, Lawrence C, Laubenbacher R. Iron acquisition and oxidative stress response in aspergillus fumigatus. BMC SYSTEMS BIOLOGY 2015; 9:19. [PMID: 25908096 PMCID: PMC4418068 DOI: 10.1186/s12918-015-0163-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 03/31/2015] [Indexed: 01/08/2023]
Abstract
BACKGROUND Aspergillus fumigatus is a ubiquitous airborne fungal pathogen that presents a life-threatening health risk to individuals with weakened immune systems. A. fumigatus pathogenicity depends on its ability to acquire iron from the host and to resist host-generated oxidative stress. Gaining a deeper understanding of the molecular mechanisms governing A. fumigatus iron acquisition and oxidative stress response may ultimately help to improve the diagnosis and treatment of invasive aspergillus infections. RESULTS This study follows a systems biology approach to investigate how adaptive behaviors emerge from molecular interactions underlying A. fumigatus iron regulation and oxidative stress response. We construct a Boolean network model from known interactions and simulate how changes in environmental iron and superoxide levels affect network dynamics. We propose rules for linking long term model behavior to qualitative estimates of cell growth and cell death. These rules are used to predict phenotypes of gene deletion strains. The model is validated on the basis of its ability to reproduce literature data not used in model generation. CONCLUSIONS The model reproduces gene expression patterns in experimental time course data when A. fumigatus is switched from a low iron to a high iron environment. In addition, the model is able to accurately represent the phenotypes of many knockout strains under varying iron and superoxide conditions. Model simulations support the hypothesis that intracellular iron regulates A. fumigatus transcription factors, SreA and HapX, by a post-translational, rather than transcriptional, mechanism. Finally, the model predicts that blocking siderophore-mediated iron uptake reduces resistance to oxidative stress. This indicates that combined targeting of siderophore-mediated iron uptake and the oxidative stress response network may act synergistically to increase fungal cell killing.
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Affiliation(s)
- Madison Brandon
- Center for Cell Analysis and Modeling, University of Connecticut Health Center, 400 Farmington Ave, Farmington, 06030, USA. .,Center for Quantitative Medicine, University of Connecticut Health Center, Farmington, 06030, USA.
| | - Brad Howard
- Department of Biological Sciences, Virginia Tech, 1405 Perry Street, Blacksburg, 24061, USA. .,Virginia Bioinformatics Institute, Virginia Tech, 1015 Life Science Circle, Blacksburg, 24061, US.
| | - Christopher Lawrence
- Department of Biological Sciences, Virginia Tech, 1405 Perry Street, Blacksburg, 24061, USA. .,Virginia Bioinformatics Institute, Virginia Tech, 1015 Life Science Circle, Blacksburg, 24061, US.
| | - Reinhard Laubenbacher
- Center for Quantitative Medicine, University of Connecticut Health Center, Farmington, 06030, USA. .,The Jackson Laboratory for Genomic Medicine, 10 Discovery Drive, Farmington, 06030, USA. .,Department of Cell Biology, University of Connecticut Health Center, 263 Farmington Ave, Farmington, 06030, USA.
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Peroxide sensing and signaling in the Sporothrix schenckii complex: an in silico analysis to uncover putative mechanisms regulating the Hog1 and AP-1 like signaling pathways. Med Mycol 2014; 53:51-9. [DOI: 10.1093/mmy/myu069] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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28
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Whole-genome comparison of Aspergillus fumigatus strains serially isolated from patients with aspergillosis. J Clin Microbiol 2014; 52:4202-9. [PMID: 25232160 DOI: 10.1128/jcm.01105-14] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The emergence of azole-resistant strains of Aspergillus fumigatus during treatment for aspergillosis occurs by a mutation selection process. Understanding how antifungal resistance mechanisms evolve in the host environment during infection is of great clinical importance and biological interest. Here, we used next-generation sequencing (NGS) to identify mutations that arose during infection by A. fumigatus strains sequentially isolated from two patients, one with invasive pulmonary aspergillosis (IPA) (five isolations) and the other with aspergilloma (three isolations). The serial isolates had identical microsatellite types, but their growth rates and conidia production levels were dissimilar. A whole-genome comparison showed that three of the five isolates from the IPA patient carried a mutation, while 22 mutations, including six nonsynonymous ones, were found among three isolates from the aspergilloma patient. One aspergilloma isolate carried the cyp51A mutation P216L, which is reported to confer azole resistance, and it displayed an MIC indicating resistance to itraconazole. This isolate harbored five other nonsynonymous mutations, some of which were found in the afyap1 and aldA genes. We further identified a large deletion in the aspergilloma isolate in a region containing 11 genes. This finding suggested the possibility that genomic deletions can occur during chronic infection with A. fumigatus. Overall, our results revealed dynamic alterations that occur in the A. fumigatus genome within its host during infection and treatment.
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29
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Muszkieta L, Carrion SDJ, Robinet P, Beau R, Elbim C, Pearlman E, Latgé JP. The protein phosphatase PhzA of A. fumigatus is involved in oxidative stress tolerance and fungal virulence. Fungal Genet Biol 2014; 66:79-85. [PMID: 24614084 DOI: 10.1016/j.fgb.2014.02.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 02/14/2014] [Accepted: 02/26/2014] [Indexed: 12/25/2022]
Abstract
Protein phosphatases Z that are unique to the fungal kingdom have been associated to resistance to high salt concentration, cell wall integrity, cell cycle regulation, and oxidative stress in fungi. In Aspergillus fumigatus, it was shown that PHZA is under the control of the transcription factor Skn7 and is only involved in the control of the oxidative stress. Accordingly, the ΔphzA mutant showed a defect in virulence in an experimental model of corneal infection in immunocompetent animals and that the impact on susceptibility to cell wall drugs is only secondary.
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Affiliation(s)
- Laetitia Muszkieta
- Unité des Aspergillus, Institut Pasteur, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France.
| | - Steven de Jesus Carrion
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Pauline Robinet
- Université Pierre et Marie Curie-Paris 6, INSERM UMR-S 945, Immunité et Infection, Hôpital Pitié Salpêtrière, Paris, France
| | - Rémi Beau
- Unité des Aspergillus, Institut Pasteur, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Carole Elbim
- Université Pierre et Marie Curie-Paris 6, INSERM UMR-S 945, Immunité et Infection, Hôpital Pitié Salpêtrière, Paris, France
| | - Eric Pearlman
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Jean-Paul Latgé
- Unité des Aspergillus, Institut Pasteur, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France
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30
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Redox regulation of an AP-1-like transcription factor, YapA, in the fungal symbiont Epichloe festucae. EUKARYOTIC CELL 2013; 12:1335-48. [PMID: 23893078 DOI: 10.1128/ec.00129-13] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
One of the central regulators of oxidative stress in Saccharomyces cerevisiae is Yap1, a bZIP transcription factor of the AP-1 family. In unstressed cells, Yap1 is reduced and cytoplasmic, but in response to oxidative stress, it becomes oxidized and accumulates in the nucleus. To date, there have been no reports on the role of AP-1-like transcription factors in symbiotic fungi. An ortholog of Yap1, named YapA, was identified in the genome of the grass symbiont Epichloë festucae and shown to complement an S. cerevisiae Δyap1 mutant. Hyphae of the E. festucae ΔyapA strain were sensitive to menadione and diamide but resistant to H2O2, KO2, and tert-butyl hydroperoxide (t-BOOH). In contrast, conidia of the ΔyapA strain were very sensitive to H2O2 and failed to germinate. Using a PcatA-eGFP degron-tagged reporter, YapA was shown to be required for expression of a spore-specific catalase gene, catA. Although YapA-EGFP localized to the nucleus in response to host reactive oxygen species during seedling infection, there was no difference in whole-plant and cellular phenotypes of plants infected with the ΔyapA strain compared to the wild-type strain. Homologs of the S. cerevisiae and Schizosaccharomyces pombe redox-sensing proteins (Gpx3 and Tpx1, respectively) did not act as redox sensors for YapA in E. festucae. In response to oxidative stress, YapA-EGFP localized to the nuclei of E. festucae ΔgpxC, ΔtpxA, and ΔgpxC ΔtpxA cells to the same degree as that in wild-type cells. These results show that E. festucae has a robust system for countering oxidative stress in culture and in planta but that Gpx3- or Tpx1-like thiol peroxidases are dispensable for activation of YapA.
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RsmA regulates Aspergillus fumigatus gliotoxin cluster metabolites including cyclo(L-Phe-L-Ser), a potential new diagnostic marker for invasive aspergillosis. PLoS One 2013; 8:e62591. [PMID: 23671611 PMCID: PMC3646020 DOI: 10.1371/journal.pone.0062591] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 03/26/2013] [Indexed: 11/19/2022] Open
Abstract
Dimeric basic leucine zipper (bZIP) proteins are conserved transcriptional enhancers found in all eukaryotes. A recently reported and novel function for bZIPs is association of these proteins with secondary metabolite production in filamentous fungi. In particular a Yap-like bZIP termed RsmA (restorer of secondary metabolism A) was identified in Aspergillus nidulans that positively regulates the carcinogen sterigmatocystin. To assess for conserved function for RsmA, we examined a role of this protein in secondary metabolism in the pathogen A. fumigatus. RsmA was found to positively regulate gliotoxin where overexpression (OE) of rsmA led to 2–100 fold increases of twelve gli cluster metabolites in culture medium including the newly identified gli metabolite cyclo(L-Phe-L-Ser). Lungs from both wild type and OErsmA infected mice contained gliotoxin (2.3 fold higher in OErsmA treatment) as well as the gliotoxin precursor cyclo(L-Phe-L-Ser) (3.2 fold higher in OErsmA treatment). The data here presents a conserved role for RsmA in secondary metabolite cluster activation and suggests cyclo(L-Phe-L-Ser) may serve as an alternative marker for diagnosis of invasive aspergillosis.
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Amich J, Krappmann S. Deciphering metabolic traits of the fungal pathogen Aspergillus fumigatus: redundancy vs. essentiality. Front Microbiol 2012; 3:414. [PMID: 23264772 PMCID: PMC3525513 DOI: 10.3389/fmicb.2012.00414] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 11/15/2012] [Indexed: 11/13/2022] Open
Abstract
Incidence rates of infections caused by environmental opportunistic fungi have risen over recent decades. Aspergillus species have emerged as serious threat for the immunecompromised, and detailed knowledge about virulence-determining traits is crucial for drug target identification. As a prime saprobe, A. fumigatus has evolved to efficiently adapt to various stresses and to sustain nutritional supply by osmotrophy, which is characterized by extracellular substrate digestion followed by efficient uptake of breakdown products that are then fed into the fungal primary metabolism. These intrinsic metabolic features are believed to be related with its virulence ability. The plethora of genes that encode underlying effectors has hampered their in-depth analysis with respect to pathogenesis. Recent developments in Aspergillus molecular biology allow conditional gene expression or comprehensive targeting of gene families to cope with redundancy. Furthermore, identification of essential genes that are intrinsically connected to virulence opens accurate perspectives for novel targets in antifungal therapy.
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Affiliation(s)
- Jorge Amich
- Research Center for Infectious Diseases, Julius-Maximilians-Universität Würzburg Würzburg, Germany
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33
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Yin WB, Reinke AW, Szilágyi M, Emri T, Chiang YM, Keating AE, Pócsi I, Wang CCC, Keller NP. bZIP transcription factors affecting secondary metabolism, sexual development and stress responses in Aspergillus nidulans. MICROBIOLOGY-SGM 2012; 159:77-88. [PMID: 23154967 DOI: 10.1099/mic.0.063370-0] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The eukaryotic basic leucine zipper (bZIP) transcription factors play critical roles in the organismal response to the environment. Recently, a novel YAP-like bZIP, restorer of secondary metabolism A (RsmA), was found in a suppressor screen of an Aspergillus nidulans secondary metabolism (SM) mutant in which overexpression of rsmA was found to partially remediate loss of SM in Velvet Complex mutants. The Velvet Complex is a conserved fungal transcriptional heteromer that couples SM with sexual development in fungi. Here we characterized and contrasted SM in mutants of RsmA and four other A. nidulans bZIP proteins (NapA, ZipA, ZipB and ZipC) with predicted DNA binding motifs similar to RsmA. Only two overexpression mutants exhibited both SM and sexual abnormalities that were noteworthy: OE : : rsmA resulted in a 100-fold increase in sterigmatocystin and a near loss of meiotic spore production. OE : : napA displayed decreased production of sterigmatocystin, emericellin, asperthecin, shamixanthone and epishamixanthone, coupled with a shift from sexual to asexual development. Quantification of bZIP homodimer and heterodimer formation using fluorescence resonance energy transfer (FRET) suggested that these proteins preferentially self-associate.
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Affiliation(s)
- Wen-Bing Yin
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, WI, USA
| | - Aaron W Reinke
- Department of Biology, Massachusetts Institute of Technology, MA, USA
| | - Melinda Szilágyi
- Department of Microbial Biotechnology and Cell Biology, University of Debrecen, Hungary
| | - Tamás Emri
- Department of Microbial Biotechnology and Cell Biology, University of Debrecen, Hungary
| | - Yi-Ming Chiang
- Department of Pharmacology and Pharmaceutical Sciences, Department of Chemistry, University of Southern California, CA, USA
| | - Amy E Keating
- Department of Biology, Massachusetts Institute of Technology, MA, USA
| | - István Pócsi
- Department of Microbial Biotechnology and Cell Biology, University of Debrecen, Hungary
| | - Clay C C Wang
- Department of Pharmacology and Pharmaceutical Sciences, Department of Chemistry, University of Southern California, CA, USA
| | - Nancy P Keller
- Department of Bacteriology, University of Wisconsin-Madison, WI, USA.,Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, WI, USA
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Leal SM, Vareechon C, Cowden S, Cobb BA, Latgé JP, Momany M, Pearlman E. Fungal antioxidant pathways promote survival against neutrophils during infection. J Clin Invest 2012; 122:2482-98. [PMID: 22706306 DOI: 10.1172/jci63239] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 05/09/2012] [Indexed: 01/15/2023] Open
Abstract
Filamentous fungi are a common cause of blindness and visual impairment worldwide. Using both murine model systems and in vitro human neutrophils, we found that NADPH oxidase produced by neutrophils was essential to control the growth of Aspergillus and Fusarium fungi in the cornea. We demonstrated that neutrophil oxidant production and antifungal activity are dependent on CD18, but not on the β-glucan receptor dectin-1. We used mutant A. fumigatus strains to show that the reactive oxygen species-sensing transcription factor Yap1, superoxide dismutases, and the Yap1-regulated thioredoxin antioxidant pathway are each required for protection against neutrophil-mediated oxidation of hyphae as well as optimal survival of fungal hyphae in vivo. We also demonstrated that thioredoxin inhibition using the anticancer drug PX-12 increased the sensitivity of fungal hyphae to both H2O2- and neutrophil-mediated killing in vitro. Additionally, topical application of PX-12 significantly enhanced neutrophil-mediated fungal killing in infected mouse corneas. Cumulatively, our data reveal critical host oxidative and fungal anti-oxidative mediators that regulate hyphal survival during infection. Further, these findings also indicate that targeting fungal anti-oxidative defenses via PX-12 may represent an efficacious strategy for treating fungal infections.
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Affiliation(s)
- Sixto M Leal
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
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35
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Carberry S, Molloy E, Hammel S, O’Keeffe G, Jones GW, Kavanagh K, Doyle S. Gliotoxin effects on fungal growth: Mechanisms and exploitation. Fungal Genet Biol 2012; 49:302-12. [DOI: 10.1016/j.fgb.2012.02.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 02/09/2012] [Accepted: 02/10/2012] [Indexed: 10/28/2022]
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36
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Grahl N, Dinamarco TM, Willger SD, Goldman GH, Cramer RA. Aspergillus fumigatus mitochondrial electron transport chain mediates oxidative stress homeostasis, hypoxia responses and fungal pathogenesis. Mol Microbiol 2012; 84:383-99. [PMID: 22443190 DOI: 10.1111/j.1365-2958.2012.08034.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
We previously observed that hypoxia is an important component of host microenvironments during pulmonary fungal infections. However, mechanisms of fungal growth in these in vivo hypoxic conditions are poorly understood. Here, we report that mitochondrial respiration is active in hypoxia (1% oxygen) and critical for fungal pathogenesis. We generated Aspergillus fumigatus alternative oxidase (aoxA) and cytochrome C (cycA) null mutants and assessed their ability to tolerate hypoxia, macrophage killing and virulence. In contrast to ΔaoxA, ΔcycA was found to be significantly impaired in conidia germination, growth in normoxia and hypoxia, and displayed attenuated virulence. Intriguingly, loss of cycA results in increased levels of AoxA activity, which results in increased resistance to oxidative stress, macrophage killing and long-term persistence in murine lungs. Thus, our results demonstrate a previously unidentified role for fungal mitochondrial respiration in the pathogenesis of aspergillosis, and lay the foundation for future research into its role in hypoxia signalling and adaptation.
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Affiliation(s)
- Nora Grahl
- Department of Immunology and Infectious Diseases, Montana State University, Bozeman, MT, USA
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Yin W, Amaike S, Wohlbach DJ, Gasch AP, Chiang YM, Wang CC, Bok J, Rohlfs M, Keller NP. An Aspergillus nidulans bZIP response pathway hardwired for defensive secondary metabolism operates through aflR. Mol Microbiol 2012; 83:1024-34. [PMID: 22283524 PMCID: PMC3288630 DOI: 10.1111/j.1365-2958.2012.07986.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The eukaryotic bZIP transcription factors are critical players in organismal response to environmental challenges. In fungi, the production of secondary metabolites (SMs) is hypothesized as one of the responses to environmental insults, e.g. attack by fungivorous insects, yet little data to support this hypothesis exists. Here we establish a mechanism of bZIP regulation of SMs through RsmA, a recently discovered YAP-like bZIP protein. RsmA greatly increases SM production by binding to two sites in the Aspergillus nidulans AflR promoter region, a C6 transcription factor known for activating production of the carcinogenic and anti-predation SM, sterigmatocystin. Deletion of aflR in an overexpression rsmA (OE:rsmA) background not only eliminates sterigmatocystin production but also significantly reduces asperthecin synthesis. Furthermore, the fungivore, Folsomia candida, exhibited a distinct preference for feeding on wild type rather than an OE:rsmA strain. RsmA may thus have a critical function in mediating direct chemical resistance against predation. Taken together, these results suggest RsmA represents a bZIP pathway hardwired for defensive SM production.
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Affiliation(s)
- Wenbing Yin
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, WI, United States
| | - Saori Amaike
- Department of Plant Pathology, University of Wisconsin-Madison, WI, United States
| | - Dana J. Wohlbach
- Department of Genetics, University of Wisconsin-Madison, WI, United States
| | - Audrey P. Gasch
- Department of Genetics, University of Wisconsin-Madison, WI, United States
| | - Yi-Ming Chiang
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, School of Pharmacy, CA, United States
| | - Clay C. Wang
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, School of Pharmacy, CA, United States
| | - JinWoo Bok
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, WI, United States
| | - Marko Rohlfs
- J.F Blumenbach Institute of Zoology and Anthropology, Georg August University Göttingen, Germany
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, WI, United States
- Department of Bacteriology, University of Wisconsin-Madison, WI, United States
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Disruption of the phospholipase D gene attenuates the virulence of Aspergillus fumigatus. Infect Immun 2011; 80:429-40. [PMID: 22083709 DOI: 10.1128/iai.05830-11] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Aspergillus fumigatus is the most prevalent airborne fungal pathogen that induces serious infections in immunocompromised patients. Phospholipases are key enzymes in pathogenic fungi that cleave host phospholipids, resulting in membrane destabilization and host cell penetration. However, knowledge of the impact of phospholipases on A. fumigatus virulence is rather limited. In this study, disruption of the pld gene encoding phospholipase D (PLD), an important member of the phospholipase protein family in A. fumigatus, was confirmed to significantly decrease both intracellular and extracellular PLD activity of A. fumigatus. The pld gene disruption did not alter conidial morphological characteristics, germination, growth, and biofilm formation but significantly suppressed the internalization of A. fumigatus into A549 epithelial cells without affecting conidial adhesion to epithelial cells. Importantly, the suppressed internalization was fully rescued in the presence of 100 μM phosphatidic acid, the PLD product. Indeed, complementation of pld restored the PLD activity and internalization capacity of A. fumigatus. Phagocytosis of A. fumigatus conidia by J774 macrophages was not affected by the absence of the pld gene. Pretreatment of conidia with 1-butanol and a specific PLD inhibitor decreased the internalization of A. fumigatus into A549 epithelial cells but had no effect on phagocytosis by J774 macrophages. Finally, loss of the pld gene attenuated the virulence of A. fumigatus in mice immunosuppressed with hydrocortisone acetate but not with cyclophosphamide. These data suggest that PLD of A. fumigatus regulates its internalization into lung epithelial cells and may represent an important virulence factor for A. fumigatus infection.
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Hartmann T, Sasse C, Schedler A, Hasenberg M, Gunzer M, Krappmann S. Shaping the fungal adaptome--stress responses of Aspergillus fumigatus. Int J Med Microbiol 2011; 301:408-16. [PMID: 21565548 DOI: 10.1016/j.ijmm.2011.04.008] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Aspergillus fumigatus as prime pathogen to cause aspergillosis has evolved as a saprophyte, but is also able to infect and colonise immunocompromised hosts. Based on the 'dual use' hypothesis of fungal pathogenicity, general characteristics have to be considered as unspecific virulence determinants, among them stress adaptation capacities. The susceptible, warm-blooded mammalian host represents a specific ecological niche that poses several kinds of stress conditions to the fungus during the course of infection. Detailed knowledge about the cellular pathways and adaptive traits that have evolved in A. fumigatus to counteract situations of stress and varying environmental conditions is crucial for the identification of novel and specific antifungal targets. Comprehensive profiling data accompanied by mutant analyses have shed light on such stressors, and nutritional deprivation, oxidative stress, hypoxia, elevated temperature, alkaline pH, extensive secretion, and, in particular during treatment with antifungals, cell membrane perturbations appear to represent the major hazards A. fumigatus has to cope with during infection. Further efforts employing innovative approaches and advanced technologies will have to be made to expand our knowledge about the scope of the A. fumigatus adaptome that is relevant for disease.
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Affiliation(s)
- Thomas Hartmann
- Research Center for Infectious Diseases, Julius-Maximilians-University Würzburg, Germany
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Roetzer A, Klopf E, Gratz N, Marcet-Houben M, Hiller E, Rupp S, Gabaldón T, Kovarik P, Schüller C. Regulation of Candida glabrata oxidative stress resistance is adapted to host environment. FEBS Lett 2010; 585:319-27. [PMID: 21156173 PMCID: PMC3022126 DOI: 10.1016/j.febslet.2010.12.006] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Revised: 12/04/2010] [Accepted: 12/07/2010] [Indexed: 01/07/2023]
Abstract
The human fungal pathogen Candida glabrata is related to Saccharomyces cerevisiae but has developed high resistance against reactive oxygen species. We find that induction of conserved genes encoding antioxidant functions is dependent on the transcription factors CgYap1 and CgSkn7 which cooperate for promoter recognition. Superoxide stress resistance of C. glabrata is provided by superoxide dismutase CgSod1, which is not dependent on CgYap1/Skn7. Only double mutants lacking both CgSod1 and CgYap1 were efficiently killed by primary mouse macrophages. Our results suggest that in C. glabrata the regulation of key genes providing stress protection is adopted to meet a host-pathogen situation.
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Affiliation(s)
- Andreas Roetzer
- Max F. Perutz Laboratories, University of Vienna, Department of Biochemistry, Vienna, Austria
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What makes Aspergillus fumigatus a successful pathogen? Genes and molecules involved in invasive aspergillosis. Rev Iberoam Micol 2010; 27:155-82. [PMID: 20974273 DOI: 10.1016/j.riam.2010.10.003] [Citation(s) in RCA: 267] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Revised: 10/06/2010] [Accepted: 10/07/2010] [Indexed: 11/21/2022] Open
Abstract
Aspergillus fumigatus is an opportunistic pathogen that causes 90% of invasive aspergillosis (IA) due to Aspergillus genus, with a 50-95% mortality rate. It has been postulated that certain virulence factors are characteristic of A. fumigatus, but the "non-classical" virulence factors seem to be highly variable. Overall, published studies have demonstrated that the virulence of this fungus is multifactorial, associated with its structure, its capacity for growth and adaptation to stress conditions, its mechanisms for evading the immune system and its ability to cause damage to the host. In this review we intend to give a general overview of the genes and molecules involved in the development of IA. The thermotolerance section focuses on five genes related with the capacity of the fungus to grow at temperatures above 30°C (thtA, cgrA, afpmt1, kre2/afmnt1, and hsp1/asp f 12). The following sections discuss molecules and genes related to interaction with the host and with the immune responses. These sections include β-glucan, α-glucan, chitin, galactomannan, galactomannoproteins (afmp1/asp f 17 and afmp2), hydrophobins (rodA/hyp1 and rodB), DHN-melanin, their respective synthases (fks1, rho1-4, ags1-3, chsA-G, och1-4, mnn9, van1, anp1, glfA, pksP/alb1, arp1, arp2, abr1, abr2, and ayg1), and modifying enzymes (gel1-7, bgt1, eng1, ecm33, afpigA, afpmt1-2, afpmt4, kre2/afmnt1, afmnt2-3, afcwh41 and pmi); several enzymes related to oxidative stress protection such as catalases (catA, cat1/catB, cat2/katG, catC, and catE), superoxide dismutases (sod1, sod2, sod3/asp f 6, and sod4), fatty acid oxygenases (ppoA-C), glutathione tranferases (gstA-E), and others (afyap1, skn7, and pes1); and efflux transporters (mdr1-4, atrF, abcA-E, and msfA-E). In addition, this review considers toxins and related genes, such as a diffusible toxic substance from conidia, gliotoxin (gliP and gliZ), mitogillin (res/mitF/asp f 1), hemolysin (aspHS), festuclavine and fumigaclavine A-C, fumitremorgin A-C, verruculogen, fumagillin, helvolic acid, aflatoxin B1 and G1, and laeA. Two sections cover genes and molecules related with nutrient uptake, signaling and metabolic regulations involved in virulence, including enzymes, such as serine proteases (alp/asp f 13, alp2, and asp f 18), metalloproteases (mep/asp f 5, mepB, and mep20), aspartic proteases (pep/asp f 10, pep2, and ctsD), dipeptidylpeptidases (dppIV and dppV), and phospholipases (plb1-3 and phospholipase C); siderophores and iron acquisition (sidA-G, sreA, ftrA, fetC, mirB-C, and amcA); zinc acquisition (zrfA-H, zafA, and pacC); amino acid biosynthesis, nitrogen uptake, and cross-pathways control (areA, rhbA, mcsA, lysF, cpcA/gcn4p, and cpcC/gcn2p); general biosynthetic pathway (pyrG, hcsA, and pabaA), trehalose biosynthesis (tpsA and tpsB), and other regulation pathways such as those of the MAP kinases (sakA/hogA, mpkA-C, ste7, pbs2, mkk2, steC/ste11, bck1, ssk2, and sho1), G-proteins (gpaA, sfaD, and cpgA), cAMP-PKA signaling (acyA, gpaB, pkaC1, and pkaR), His kinases (fos1 and tcsB), Ca(2+) signaling (calA/cnaA, crzA, gprC and gprD), and Ras family (rasA, rasB, and rhbA), and others (ace2, medA, and srbA). Finally, we also comment on the effect of A. fumigatus allergens (Asp f 1-Asp f 34) on IA. The data gathered generate a complex puzzle, the pieces representing virulence factors or the different activities of the fungus, and these need to be arranged to obtain a comprehensive vision of the virulence of A. fumigatus. The most recent gene expression studies using DNA-microarrays may be help us to understand this complex virulence, and to detect targets to develop rapid diagnostic methods and new antifungal agents.
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Truncated Afyap1 Attenuates Antifungal Susceptibility of Aspergillus fumigatus to Voriconazole and Confers Adaptation of the Fungus to Oxidative Stress. Mycopathologia 2010; 170:155-60. [DOI: 10.1007/s11046-010-9309-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Accepted: 03/21/2010] [Indexed: 11/25/2022]
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Lambou K, Lamarre C, Beau R, Dufour N, Latge JP. Functional analysis of the superoxide dismutase family inAspergillus fumigatus. Mol Microbiol 2010; 75:910-23. [DOI: 10.1111/j.1365-2958.2009.07024.x] [Citation(s) in RCA: 143] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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