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Xiong J, Wang L, Feng Z, Hang S, Yu J, Feng Y, Lu H, Jiang Y. Halofantrine Hydrochloride Acts as an Antioxidant Ability Inhibitor That Enhances Oxidative Stress Damage to Candida albicans. Antioxidants (Basel) 2024; 13:223. [PMID: 38397821 PMCID: PMC10886025 DOI: 10.3390/antiox13020223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/25/2024] [Accepted: 02/06/2024] [Indexed: 02/25/2024] Open
Abstract
Candida albicans, a prominent opportunistic pathogenic fungus in the human population, possesses the capacity to induce life-threatening invasive candidiasis in individuals with compromised immune systems despite the existence of antifungal medications. When faced with macrophages or neutrophils, C. albicans demonstrates its capability to endure oxidative stress through the utilization of antioxidant enzymes. Therefore, the enhancement of oxidative stress in innate immune cells against C. albicans presents a promising therapeutic approach for the treatment of invasive candidiasis. In this study, we conducted a comprehensive analysis of a library of drugs approved by the Food and Drug Administration (FDA). We discovered that halofantrine hydrochloride (HAL) can augment the antifungal properties of oxidative damage agents (plumbagin, menadione, and H2O2) by suppressing the response of C. albicans to reactive oxygen species (ROS). Furthermore, our investigation revealed that the inhibitory mechanism of HAL on the oxidative response is dependent on Cap1. In addition, the antifungal activity of HAL has been observed in the Galleria mellonella infection model. These findings provide evidence that targeting the oxidative stress response of C. albicans and augmenting the fungicidal capacity of oxidative damage agents hold promise as effective antifungal strategies.
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Affiliation(s)
| | | | | | | | | | | | - Hui Lu
- Department of Pharmacy, Shanghai Tenth People’s Hospital, School of Medicine, Tongji University, Shanghai 200072, China
| | - Yuanying Jiang
- Department of Pharmacy, Shanghai Tenth People’s Hospital, School of Medicine, Tongji University, Shanghai 200072, China
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2
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Fusco-Almeida AM, de Matos Silva S, dos Santos KS, de Lima Gualque MW, Vaso CO, Carvalho AR, Medina-Alarcón KP, Pires ACMDS, Belizario JA, de Souza Fernandes L, Moroz A, Martinez LR, Ruiz OH, González Á, Mendes-Giannini MJS. Alternative Non-Mammalian Animal and Cellular Methods for the Study of Host-Fungal Interactions. J Fungi (Basel) 2023; 9:943. [PMID: 37755051 PMCID: PMC10533014 DOI: 10.3390/jof9090943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 08/28/2023] [Accepted: 08/30/2023] [Indexed: 09/28/2023] Open
Abstract
In the study of fungal pathogenesis, alternative methods have gained prominence due to recent global legislation restricting the use of mammalian animals in research. The principle of the 3 Rs (replacement, reduction, and refinement) is integrated into regulations and guidelines governing animal experimentation in nearly all countries. This principle advocates substituting vertebrate animals with other invertebrate organisms, embryos, microorganisms, or cell cultures. This review addresses host-fungus interactions by employing three-dimensional (3D) cultures, which offer more faithful replication of the in vivo environment, and by utilizing alternative animal models to replace traditional mammals. Among these alternative models, species like Caenorhabditis elegans and Danio rerio share approximately 75% of their genes with humans. Furthermore, models such as Galleria mellonella and Tenebrio molitor demonstrate similarities in their innate immune systems as well as anatomical and physiological barriers, resembling those found in mammalian organisms.
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Affiliation(s)
- Ana Marisa Fusco-Almeida
- Department of Clinical Analysis, School of Pharmaceutical Science, Universidade Estadual Paulista (UNESP), Araraquara 14800-903, SP, Brazil; (A.M.F.-A.); (S.d.M.S.); (K.S.d.S.); (M.W.d.L.G.); (C.O.V.); (A.R.C.); (K.P.M.-A.); (A.C.M.d.S.P.); (J.A.B.); (L.d.S.F.); (A.M.)
| | - Samanta de Matos Silva
- Department of Clinical Analysis, School of Pharmaceutical Science, Universidade Estadual Paulista (UNESP), Araraquara 14800-903, SP, Brazil; (A.M.F.-A.); (S.d.M.S.); (K.S.d.S.); (M.W.d.L.G.); (C.O.V.); (A.R.C.); (K.P.M.-A.); (A.C.M.d.S.P.); (J.A.B.); (L.d.S.F.); (A.M.)
- Basic and Applied Microbiology Group (MICROBA), School of Microbiology, Universidad de Antioquia, Medellin 050010, Colombia; (O.H.R.); (Á.G.)
| | - Kelvin Sousa dos Santos
- Department of Clinical Analysis, School of Pharmaceutical Science, Universidade Estadual Paulista (UNESP), Araraquara 14800-903, SP, Brazil; (A.M.F.-A.); (S.d.M.S.); (K.S.d.S.); (M.W.d.L.G.); (C.O.V.); (A.R.C.); (K.P.M.-A.); (A.C.M.d.S.P.); (J.A.B.); (L.d.S.F.); (A.M.)
| | - Marcos William de Lima Gualque
- Department of Clinical Analysis, School of Pharmaceutical Science, Universidade Estadual Paulista (UNESP), Araraquara 14800-903, SP, Brazil; (A.M.F.-A.); (S.d.M.S.); (K.S.d.S.); (M.W.d.L.G.); (C.O.V.); (A.R.C.); (K.P.M.-A.); (A.C.M.d.S.P.); (J.A.B.); (L.d.S.F.); (A.M.)
| | - Carolina Orlando Vaso
- Department of Clinical Analysis, School of Pharmaceutical Science, Universidade Estadual Paulista (UNESP), Araraquara 14800-903, SP, Brazil; (A.M.F.-A.); (S.d.M.S.); (K.S.d.S.); (M.W.d.L.G.); (C.O.V.); (A.R.C.); (K.P.M.-A.); (A.C.M.d.S.P.); (J.A.B.); (L.d.S.F.); (A.M.)
| | - Angélica Romão Carvalho
- Department of Clinical Analysis, School of Pharmaceutical Science, Universidade Estadual Paulista (UNESP), Araraquara 14800-903, SP, Brazil; (A.M.F.-A.); (S.d.M.S.); (K.S.d.S.); (M.W.d.L.G.); (C.O.V.); (A.R.C.); (K.P.M.-A.); (A.C.M.d.S.P.); (J.A.B.); (L.d.S.F.); (A.M.)
| | - Kaila Petrolina Medina-Alarcón
- Department of Clinical Analysis, School of Pharmaceutical Science, Universidade Estadual Paulista (UNESP), Araraquara 14800-903, SP, Brazil; (A.M.F.-A.); (S.d.M.S.); (K.S.d.S.); (M.W.d.L.G.); (C.O.V.); (A.R.C.); (K.P.M.-A.); (A.C.M.d.S.P.); (J.A.B.); (L.d.S.F.); (A.M.)
| | - Ana Carolina Moreira da Silva Pires
- Department of Clinical Analysis, School of Pharmaceutical Science, Universidade Estadual Paulista (UNESP), Araraquara 14800-903, SP, Brazil; (A.M.F.-A.); (S.d.M.S.); (K.S.d.S.); (M.W.d.L.G.); (C.O.V.); (A.R.C.); (K.P.M.-A.); (A.C.M.d.S.P.); (J.A.B.); (L.d.S.F.); (A.M.)
| | - Jenyffie Araújo Belizario
- Department of Clinical Analysis, School of Pharmaceutical Science, Universidade Estadual Paulista (UNESP), Araraquara 14800-903, SP, Brazil; (A.M.F.-A.); (S.d.M.S.); (K.S.d.S.); (M.W.d.L.G.); (C.O.V.); (A.R.C.); (K.P.M.-A.); (A.C.M.d.S.P.); (J.A.B.); (L.d.S.F.); (A.M.)
| | - Lígia de Souza Fernandes
- Department of Clinical Analysis, School of Pharmaceutical Science, Universidade Estadual Paulista (UNESP), Araraquara 14800-903, SP, Brazil; (A.M.F.-A.); (S.d.M.S.); (K.S.d.S.); (M.W.d.L.G.); (C.O.V.); (A.R.C.); (K.P.M.-A.); (A.C.M.d.S.P.); (J.A.B.); (L.d.S.F.); (A.M.)
| | - Andrei Moroz
- Department of Clinical Analysis, School of Pharmaceutical Science, Universidade Estadual Paulista (UNESP), Araraquara 14800-903, SP, Brazil; (A.M.F.-A.); (S.d.M.S.); (K.S.d.S.); (M.W.d.L.G.); (C.O.V.); (A.R.C.); (K.P.M.-A.); (A.C.M.d.S.P.); (J.A.B.); (L.d.S.F.); (A.M.)
| | - Luis R. Martinez
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL 32610, USA;
- Emerging Pathogens Institute, University of Florida, Gainesville, FL 32610, USA
- Center for Immunology and Transplantation, University of Florida, Gainesville, FL 32610, USA
- Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL 32610, USA
| | - Orville Hernandez Ruiz
- Basic and Applied Microbiology Group (MICROBA), School of Microbiology, Universidad de Antioquia, Medellin 050010, Colombia; (O.H.R.); (Á.G.)
- Cellular and Molecular Biology Group University of Antioquia, Corporation for Biological Research, Medellin 050010, Colombia
| | - Ángel González
- Basic and Applied Microbiology Group (MICROBA), School of Microbiology, Universidad de Antioquia, Medellin 050010, Colombia; (O.H.R.); (Á.G.)
| | - Maria José Soares Mendes-Giannini
- Department of Clinical Analysis, School of Pharmaceutical Science, Universidade Estadual Paulista (UNESP), Araraquara 14800-903, SP, Brazil; (A.M.F.-A.); (S.d.M.S.); (K.S.d.S.); (M.W.d.L.G.); (C.O.V.); (A.R.C.); (K.P.M.-A.); (A.C.M.d.S.P.); (J.A.B.); (L.d.S.F.); (A.M.)
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Chen ZH, Li J, Zhao XX, Yang XH, Li J, Zou B, Zang WB, Ma RX, Wang YF, Yao Y. Saikogenin F From Bupleurum smithii Ameliorates Learning and Memory Impairment via Antiinflammation Effect in an Alzheimer’s Disease Mouse Model. Nat Prod Commun 2022. [DOI: 10.1177/1934578x221111029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disease associated with aging. Bupleurum smithii Wolff. is a Chinese folk medicine used to reduce fever and inflammation. Regarding the key role of neuroinflammation in AD pathogenesis, it was speculated that B. smithii may be the source of compounds that treat AD through anti-inflammatory effects. This study aimed to investigate the effects of saikogenin F, a natural active ingredient from B. smithii, on cognition impairment and neuroinflammation in AD mice induced by amyloid β (Aβ). The AD mice model was established by intracerebroventricular (i.c.v.) injection of Aβ, and different doses of saikogenin F (10, 20, and 40 mg/kg) were intragastrically administrated once daily. Results of behavioral experiments, including the novel object recognition (NOR) test, Y-maze test, and Morris water maze (MWZ) test, showed that saikogenin F could ameliorate Aβ-induced cognition impairment in AD mice. Enzyme linked immunosorbent assay (ELISA) results showed that tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and reactive oxygen species (ROS) levels in hippocampal tissue increased after Aβ injection, while saikogenin F could significantly reduce the concentrations of these inflammatory factors. Western blotting results revealed that the Aβ-induced reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits protein expression in mice hippocampus was remarkably downregulated by saikogenin F. Results of Iba-1 immunohistochemical staining showed that saikogenin F could effectively inhibit Aβ-induced activation of microglia in vivo. These results suggested that saikogenin F could relieve Aβ-induced cognitive impairment via inhibiting neuroinflammation and microglial activation. These effects may be achieved by inhibiting the expression of the NADPH oxidase subunits gp91phox and p47phox.
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Affiliation(s)
- Ze-Hui Chen
- School of Pharmacy, Ningxia Medical University, Yinchuan, China
| | - Juan Li
- School of Pharmacy, Ningxia Medical University, Yinchuan, China
- Ningxia Engineering and Technology Research Center for Modernization of Characteristic Chinese Medicine, and Key Laboratory of Ningxia Ethnomedicine Modernization, Ministry of Education, Ningxia Medical University, Yinchuan, China
| | - Xun-Xia Zhao
- School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, China
| | - Xin-He Yang
- School of Pharmacy, Ningxia Medical University, Yinchuan, China
| | - Jia Li
- School of Pharmacy, Ningxia Medical University, Yinchuan, China
| | - Bin Zou
- School of Pharmacy, Ningxia Medical University, Yinchuan, China
| | - Wei-Biao Zang
- School of Pharmacy, Ningxia Medical University, Yinchuan, China
| | - Rui-Xia Ma
- School of Pharmacy, Ningxia Medical University, Yinchuan, China
| | - Ye-Feng Wang
- School of Public Health and Management, Ningxia Medical University, Yinchuan, China
| | - Yao Yao
- School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, China
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4
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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: 24] [Impact Index Per Article: 12.0] [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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5
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Host defense mechanisms induce genome instability leading to rapid evolution in an opportunistic fungal pathogen. Infect Immun 2021; 90:e0032821. [PMID: 34898249 DOI: 10.1128/iai.00328-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The ability to generate genetic variation facilitates rapid adaptation in stressful environments. The opportunistic fungal pathogen Candida albicans frequently undergoes large-scale genomic changes, including aneuploidy and loss-of heterozygosity (LOH), following exposure to host environments. However, the specific host factors inducing C. albicans genome instability remain largely unknown. Here, we leveraged the genetic tractability of nematode hosts to investigate whether innate immune components, including antimicrobial peptides (AMPs) and reactive oxygen species (ROS), induced host-associated C. albicans genome instability. C. albicans associated with immunocompetent hosts carried multiple large-scale genomic changes including LOH, whole chromosome, and segmental aneuploidies. In contrast, C. albicans associated with immunocompromised hosts deficient in AMPs or ROS production had reduced LOH frequencies and fewer, if any, additional genomic changes. To evaluate if extensive host-induced genomic changes had long-term consequences for C. albicans adaptation, we experimentally evolved C. albicans in either immunocompetent or immunocompromised hosts and selected for increased virulence. C. albicans evolved in immunocompetent hosts rapidly increased virulence, but not in immunocompromised hosts. Taken together, this work suggests that host-produced ROS and AMPs induces genotypic plasticity in C. albicans which facilitates rapid evolution.
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Ahamefule CS, Ezeuduji BC, Ogbonna JC, Moneke AN, Ike AC, Jin C, Wang B, Fang W. Caenorhabditis elegans as an Infection Model for Pathogenic Mold and Dimorphic Fungi: Applications and Challenges. Front Cell Infect Microbiol 2021; 11:751947. [PMID: 34722339 PMCID: PMC8554291 DOI: 10.3389/fcimb.2021.751947] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 09/28/2021] [Indexed: 11/13/2022] Open
Abstract
The threat burden from pathogenic fungi is universal and increasing with alarming high mortality and morbidity rates from invasive fungal infections. Understanding the virulence factors of these fungi, screening effective antifungal agents and exploring appropriate treatment approaches in in vivo modeling organisms are vital research projects for controlling mycoses. Caenorhabditis elegans has been proven to be a valuable tool in studies of most clinically relevant dimorphic fungi, helping to identify a number of virulence factors and immune-regulators and screen effective antifungal agents without cytotoxic effects. However, little has been achieved and reported with regard to pathogenic filamentous fungi (molds) in the nematode model. In this review, we have summarized the enormous breakthrough of applying a C. elegans infection model for dimorphic fungi studies and the very few reports for filamentous fungi. We have also identified and discussed the challenges in C. elegans-mold modeling applications as well as the possible approaches to conquer these challenges from our practical knowledge in C. elegans-Aspergillus fumigatus model.
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Affiliation(s)
- Chukwuemeka Samson Ahamefule
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, China.,College of Life Science and Technology, Guangxi University, Nanning, China.,Department of Microbiology, University of Nigeria, Nsukka, Nigeria
| | | | - James C Ogbonna
- Department of Microbiology, University of Nigeria, Nsukka, Nigeria
| | - Anene N Moneke
- Department of Microbiology, University of Nigeria, Nsukka, Nigeria
| | - Anthony C Ike
- Department of Microbiology, University of Nigeria, Nsukka, Nigeria
| | - Cheng Jin
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, China.,College of Life Science and Technology, Guangxi University, Nanning, China
| | - Bin Wang
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, China.,State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning, China
| | - Wenxia Fang
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, China.,State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning, China
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Chen F, Yang D, Cheng XY, Yang H, Yang XH, Liu HT, Wang R, Zheng P, Yao Y, Li J. Astragaloside IV Ameliorates Cognitive Impairment and Neuroinflammation in an Oligomeric Aβ Induced Alzheimer's Disease Mouse Model via Inhibition of Microglial Activation and NADPH Oxidase Expression. Biol Pharm Bull 2021; 44:1688-1696. [PMID: 34433707 DOI: 10.1248/bpb.b21-00381] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Microglial activation and neuroinflammation induced by amyloid β (Aβ) play pivotal roles in Alzheimer's disease (AD) pathogenesis. Astragaloside IV (AS-IV) is one of the major active compounds of the traditional Chinese medicine Astmgali Radix. It has been reported that AS-IV could protect against Aβ-induced neuroinflammation and cognitive impairment, but the underlying mechanisms need to be further clarified. In this study, the therapeutic effects of AS-IV were investigated in an oligomeric Aβ (oAβ) induced AD mice model. The effects of AS-IV on microglial activation, neuronal damage and reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase expression were further studied. Different doses of AS-IV were administered intragastrically once a day after intracerebroventricularly oAβ injection. Results of behavioral experiments including novel object recognition (NOR) test and Morris water maze (MWM) test revealed that AS-IV administration could significantly ameliorate oAβ-induced cognitive impairment in a dose dependent manner. Enzyme linked immunosorbent assay (ELISA) results showed that increased levels of reactive oxygen species (ROS), tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β) and IL-6 in hippocampal tissues induced by oAβ injection were remarkably inhibited after AS-IV treatment. OAβ induced microglial activation and neuronal damage was significantly suppressed in AS-IV-treated mice brain, observed in immunohistochemistry results. Furthermore, oAβ upregulated protein expression of NADPH oxidase subunits gp91phox, p47phox, p22phox and p67phox were remarkably reduced by AS-IV in Western blotting assay. These results revealed that AS-IV could ameliorate oAβ-induced cognitive impairment, neuroinflammation and neuronal damage, which were possibly mediated by inhibition of microglial activation and down-regulation of NADPH oxidase protein expression. Our findings provide new insights of AS-IV for the treatment of neuroinflammation related diseases such as AD.
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Affiliation(s)
- Fei Chen
- School of Pharmacy, Ningxia Engineering and Technology Research Center for Modernization of Traditional Chinese Medicine, and Key Laboratory of Traditional Chinese Medicine Modernization, Ministry of Education, Ningxia Medical University
| | - Dan Yang
- School of Pharmacy, Ningxia Engineering and Technology Research Center for Modernization of Traditional Chinese Medicine, and Key Laboratory of Traditional Chinese Medicine Modernization, Ministry of Education, Ningxia Medical University
| | - Xiao-Yu Cheng
- Department of Neurology and Suzhou Clinical Research Center of Neurological Disease, the Second Affiliated Hospital, Soochow University
| | - Hui Yang
- Research Center of Medical Science and Technology, Ningxia Medical University
| | - Xin-He Yang
- School of Pharmacy, Ningxia Engineering and Technology Research Center for Modernization of Traditional Chinese Medicine, and Key Laboratory of Traditional Chinese Medicine Modernization, Ministry of Education, Ningxia Medical University
| | - He-Tao Liu
- School of Basic Medical Sciences, Ningxia Medical University
| | - Rui Wang
- School of Pharmacy, Ningxia Engineering and Technology Research Center for Modernization of Traditional Chinese Medicine, and Key Laboratory of Traditional Chinese Medicine Modernization, Ministry of Education, Ningxia Medical University
| | - Ping Zheng
- School of Pharmacy, Ningxia Engineering and Technology Research Center for Modernization of Traditional Chinese Medicine, and Key Laboratory of Traditional Chinese Medicine Modernization, Ministry of Education, Ningxia Medical University
| | - Yao Yao
- School of Basic Medical Sciences, Ningxia Medical University
| | - Juan Li
- School of Pharmacy, Ningxia Engineering and Technology Research Center for Modernization of Traditional Chinese Medicine, and Key Laboratory of Traditional Chinese Medicine Modernization, Ministry of Education, Ningxia Medical University
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8
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d'Enfert C, Kaune AK, Alaban LR, Chakraborty S, Cole N, Delavy M, Kosmala D, Marsaux B, Fróis-Martins R, Morelli M, Rosati D, Valentine M, Xie Z, Emritloll Y, Warn PA, Bequet F, Bougnoux ME, Bornes S, Gresnigt MS, Hube B, Jacobsen ID, Legrand M, Leibundgut-Landmann S, Manichanh C, Munro CA, Netea MG, Queiroz K, Roget K, Thomas V, Thoral C, Van den Abbeele P, Walker AW, Brown AJP. The impact of the Fungus-Host-Microbiota interplay upon Candida albicans infections: current knowledge and new perspectives. FEMS Microbiol Rev 2021; 45:fuaa060. [PMID: 33232448 PMCID: PMC8100220 DOI: 10.1093/femsre/fuaa060] [Citation(s) in RCA: 126] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 11/18/2020] [Indexed: 12/11/2022] Open
Abstract
Candida albicans is a major fungal pathogen of humans. It exists as a commensal in the oral cavity, gut or genital tract of most individuals, constrained by the local microbiota, epithelial barriers and immune defences. Their perturbation can lead to fungal outgrowth and the development of mucosal infections such as oropharyngeal or vulvovaginal candidiasis, and patients with compromised immunity are susceptible to life-threatening systemic infections. The importance of the interplay between fungus, host and microbiota in driving the transition from C. albicans commensalism to pathogenicity is widely appreciated. However, the complexity of these interactions, and the significant impact of fungal, host and microbiota variability upon disease severity and outcome, are less well understood. Therefore, we summarise the features of the fungus that promote infection, and how genetic variation between clinical isolates influences pathogenicity. We discuss antifungal immunity, how this differs between mucosae, and how individual variation influences a person's susceptibility to infection. Also, we describe factors that influence the composition of gut, oral and vaginal microbiotas, and how these affect fungal colonisation and antifungal immunity. We argue that a detailed understanding of these variables, which underlie fungal-host-microbiota interactions, will present opportunities for directed antifungal therapies that benefit vulnerable patients.
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Affiliation(s)
- Christophe d'Enfert
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC 2019 INRA, 25, rue du Docteur Roux, 75015 Paris, France
| | - Ann-Kristin Kaune
- Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, Ashgrove Road West, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Leovigildo-Rey Alaban
- BIOASTER Microbiology Technology Institute, 40 avenue Tony Garnier, 69007 Lyon, France
- Université de Paris, Sorbonne Paris Cité, 25, rue du Docteur Roux, 75015 Paris, France
| | - Sayoni Chakraborty
- Microbial Immunology Research Group, Emmy Noether Junior Research Group Adaptive Pathogenicity Strategies, and the Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Beutenbergstraße 11a, 07745 Jena, Germany
- Institute of Microbiology, Friedrich Schiller University, Neugasse 25, 07743 Jena, Germany
| | - Nathaniel Cole
- Gut Microbiology Group, Rowett Institute, University of Aberdeen, Ashgrove Road West, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Margot Delavy
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC 2019 INRA, 25, rue du Docteur Roux, 75015 Paris, France
- Université de Paris, Sorbonne Paris Cité, 25, rue du Docteur Roux, 75015 Paris, France
| | - Daria Kosmala
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC 2019 INRA, 25, rue du Docteur Roux, 75015 Paris, France
- Université de Paris, Sorbonne Paris Cité, 25, rue du Docteur Roux, 75015 Paris, France
| | - Benoît Marsaux
- ProDigest BV, Technologiepark 94, B-9052 Gent, Belgium
- Center for Microbial Ecology and Technology (CMET), Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Coupure Links, 9000 Ghent, Belgium
| | - Ricardo Fróis-Martins
- Immunology Section, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 266a, Zurich 8057, Switzerland
- Institute of Experimental Immunology, University of Zurich, Winterthurerstrasse 190, Zürich 8057, Switzerland
| | - Moran Morelli
- Mimetas, Biopartner Building 2, J.H. Oortweg 19, 2333 CH Leiden, The Netherlands
| | - Diletta Rosati
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands
| | - Marisa Valentine
- Microbial Immunology Research Group, Emmy Noether Junior Research Group Adaptive Pathogenicity Strategies, and the Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Beutenbergstraße 11a, 07745 Jena, Germany
| | - Zixuan Xie
- Gut Microbiome Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Passeig Vall d'Hebron 119–129, 08035 Barcelona, Spain
| | - Yoan Emritloll
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC 2019 INRA, 25, rue du Docteur Roux, 75015 Paris, France
| | - Peter A Warn
- Magic Bullet Consulting, Biddlecombe House, Ugbrook, Chudleigh Devon, TQ130AD, UK
| | - Frédéric Bequet
- BIOASTER Microbiology Technology Institute, 40 avenue Tony Garnier, 69007 Lyon, France
| | - Marie-Elisabeth Bougnoux
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC 2019 INRA, 25, rue du Docteur Roux, 75015 Paris, France
| | - Stephanie Bornes
- Université Clermont Auvergne, INRAE, VetAgro Sup, UMRF0545, 20 Côte de Reyne, 15000 Aurillac, France
| | - Mark S Gresnigt
- Microbial Immunology Research Group, Emmy Noether Junior Research Group Adaptive Pathogenicity Strategies, and the Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Beutenbergstraße 11a, 07745 Jena, Germany
| | - Bernhard Hube
- Microbial Immunology Research Group, Emmy Noether Junior Research Group Adaptive Pathogenicity Strategies, and the Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Beutenbergstraße 11a, 07745 Jena, Germany
| | - Ilse D Jacobsen
- Microbial Immunology Research Group, Emmy Noether Junior Research Group Adaptive Pathogenicity Strategies, and the Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Beutenbergstraße 11a, 07745 Jena, Germany
| | - Mélanie Legrand
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC 2019 INRA, 25, rue du Docteur Roux, 75015 Paris, France
| | - Salomé Leibundgut-Landmann
- Immunology Section, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 266a, Zurich 8057, Switzerland
- Institute of Experimental Immunology, University of Zurich, Winterthurerstrasse 190, Zürich 8057, Switzerland
| | - Chaysavanh Manichanh
- Gut Microbiome Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Passeig Vall d'Hebron 119–129, 08035 Barcelona, Spain
| | - Carol A Munro
- Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, Ashgrove Road West, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Mihai G Netea
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands
| | - Karla Queiroz
- Mimetas, Biopartner Building 2, J.H. Oortweg 19, 2333 CH Leiden, The Netherlands
| | - Karine Roget
- NEXBIOME Therapeutics, 22 allée Alan Turing, 63000 Clermont-Ferrand, France
| | - Vincent Thomas
- BIOASTER Microbiology Technology Institute, 40 avenue Tony Garnier, 69007 Lyon, France
| | - Claudia Thoral
- NEXBIOME Therapeutics, 22 allée Alan Turing, 63000 Clermont-Ferrand, France
| | | | - Alan W Walker
- Gut Microbiology Group, Rowett Institute, University of Aberdeen, Ashgrove Road West, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Alistair J P Brown
- MRC Centre for Medical Mycology, Department of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK
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9
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Rosiana S, Zhang L, Kim GH, Revtovich AV, Uthayakumar D, Sukumaran A, Geddes-McAlister J, Kirienko NV, Shapiro RS. Comprehensive genetic analysis of adhesin proteins and their role in virulence of Candida albicans. Genetics 2021; 217:iyab003. [PMID: 33724419 PMCID: PMC8045720 DOI: 10.1093/genetics/iyab003] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 12/31/2020] [Indexed: 12/14/2022] Open
Abstract
Candida albicans is a microbial fungus that exists as a commensal member of the human microbiome and an opportunistic pathogen. Cell surface-associated adhesin proteins play a crucial role in C. albicans' ability to undergo cellular morphogenesis, develop robust biofilms, colonize, and cause infection in a host. However, a comprehensive analysis of the role and relationships between these adhesins has not been explored. We previously established a CRISPR-based platform for efficient generation of single- and double-gene deletions in C. albicans, which was used to construct a library of 144 mutants, comprising 12 unique adhesin genes deleted singly, and every possible combination of double deletions. Here, we exploit this adhesin mutant library to explore the role of adhesin proteins in C. albicans virulence. We perform a comprehensive, high-throughput screen of this library, using Caenorhabditis elegans as a simplified model host system, which identified mutants critical for virulence and significant genetic interactions. We perform follow-up analysis to assess the ability of high- and low-virulence strains to undergo cellular morphogenesis and form biofilms in vitro, as well as to colonize the C. elegans host. We further perform genetic interaction analysis to identify novel significant negative genetic interactions between adhesin mutants, whereby combinatorial perturbation of these genes significantly impairs virulence, more than expected based on virulence of the single mutant constituent strains. Together, this study yields important new insight into the role of adhesins, singly and in combinations, in mediating diverse facets of virulence of this critical fungal pathogen.
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Affiliation(s)
- Sierra Rosiana
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON NIG 2W1, Canada
| | - Liyang Zhang
- Department of BioSciences, Rice University, Houston, TX 77005, USA
| | - Grace H Kim
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON NIG 2W1, Canada
| | | | - Deeva Uthayakumar
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON NIG 2W1, Canada
| | - Arjun Sukumaran
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON NIG 2W1, Canada
| | | | | | - Rebecca S Shapiro
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON NIG 2W1, Canada
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10
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Feistel DJ, Elmostafa R, Hickman MA. Virulence phenotypes result from interactions between pathogen ploidy and genetic background. Ecol Evol 2020; 10:9326-9338. [PMID: 32953064 PMCID: PMC7487253 DOI: 10.1002/ece3.6619] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 07/02/2020] [Accepted: 07/06/2020] [Indexed: 12/25/2022] Open
Abstract
Studying fungal virulence is often challenging and frequently depends on many contexts, including host immune status and pathogen genetic background. However, the role of ploidy has often been overlooked when studying virulence in eukaryotic pathogens. Since fungal pathogens, including the human opportunistic pathogen Candida albicans, can display extensive ploidy variation, assessing how ploidy impacts virulence has important clinical relevance. As an opportunistic pathogen, C. albicans causes nonlethal, superficial infections in healthy individuals, but life-threatening bloodstream infections in individuals with compromised immune function. Here, we determined how both ploidy and genetic background of C. albicans impacts virulence phenotypes in healthy and immunocompromised nematode hosts by characterizing virulence phenotypes in four near-isogenic diploid and tetraploid pairs of strains, which included both laboratory and clinical genetic backgrounds. We found that C. albicans infections decreased host survival and negatively impacted host reproduction, and we leveraged these two measures to survey both lethal and nonlethal virulence phenotypes across the multiple C. albicans strains. In this study, we found that regardless of pathogen ploidy or genetic background, immunocompromised hosts were susceptible to fungal infection compared to healthy hosts. Furthermore, for each host context, we found a significant interaction between C. albicans genetic background and ploidy on virulence phenotypes, but no global differences between diploid and tetraploid pathogens were observed.
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11
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A Novel Virulence Phenotype Rapidly Assesses Candida Fungal Pathogenesis in Healthy and Immunocompromised Caenorhabditis elegans Hosts. mSphere 2019; 4:4/2/e00697-18. [PMID: 30971447 PMCID: PMC6458437 DOI: 10.1128/msphere.00697-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Opportunistic pathogens are commensals capable of causing disease and are serious threats to human health. It is critical to understand the mechanisms and host contexts under which opportunistic pathogens become virulent. In this work, we present a novel assay to quickly and quantitatively measure pathogen virulence in healthy and immunocompromised nematode hosts. We found that Candida species, one of the most prominent fungal opportunistic pathogens of humans, decrease host fitness by reducing survival and impacting host reproduction. Most importantly, by measuring virulence in hosts that have intact or compromised immune function, we can reveal the pathogenic potential of opportunistic fungal pathogens. The yeast Candida albicans is an opportunistic pathogen of humans, meaning that despite commensal interactions with its host, it can transition to a harmful pathogen. While C. albicans is the predominant species isolated in the human gastrointestinal mycobiome and is implicated in fungal infection, infections due to non-albicans Candida species are rapidly rising. Studying the factors that contribute to virulence is often challenging and frequently depends on many contexts, including host immune status and pathogen genetic background. Here, we utilize the nematode Caenorhabditis elegans as a perspicuous and efficient model host system to study fungal infections of Candida pathogens. We find that, in addition to reducing lifetime host survival, exposure to C. albicans results in delayed reproduction, which significantly reduced lineage growth over multiple generations. Furthermore, we assessed fungal pathogen virulence in C. elegans hosts compromised for innate immune function and detected increased early mortality, reduced brood sizes, and delayed reproduction relative to infected healthy hosts. Importantly, by assessing virulence in both healthy and immunocompromised host backgrounds, we reveal the pathogen potential in non-albicans Candida species. Taken together, we present a novel lineage growth assay to measure reduction in host fitness associated with fungal infection and demonstrate significant interactions between pathogen and host immune function that contribute to virulence. IMPORTANCE Opportunistic pathogens are commensals capable of causing disease and are serious threats to human health. It is critical to understand the mechanisms and host contexts under which opportunistic pathogens become virulent. In this work, we present a novel assay to quickly and quantitatively measure pathogen virulence in healthy and immunocompromised nematode hosts. We found that Candida species, one of the most prominent fungal opportunistic pathogens of humans, decrease host fitness by reducing survival and impacting host reproduction. Most importantly, by measuring virulence in hosts that have intact or compromised immune function, we can reveal the pathogenic potential of opportunistic fungal pathogens.
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12
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Genetically Compromising Phospholipid Metabolism Limits Candida albicans' Virulence. Mycopathologia 2019; 184:213-226. [PMID: 30693413 DOI: 10.1007/s11046-019-00320-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 01/19/2019] [Indexed: 01/06/2023]
Abstract
Perturbing ergosterol synthesis has been previously shown to reduce the virulence of Candida albicans. We tested the hypothesis that further altering cell membrane composition by limiting phospholipid synthesis or remodeling will have the same effect. To model partial inhibition, C. albicans strains independently harboring heterozygous deletion of four genes that encode for enzymes that mediate phospholipid synthesis or modification were generated. Quantitative PCR determined that heterozygous deletion routinely caused a nearly 50% reduction in the respective gene's transcript abundance. Compensatory increased transcript abundance was only found with the deletion of LRO1, a homolog of phospholipid diacylglycerol acyltransferases. Virulence of the mutants was assayed in a Caenorhabditis elegans host model. Even modestly reduced expression of LRO1, phosphatidylserine synthase (CHO1), and lysophospholipid acyltransferase (LPT1) significantly reduced virulence by 23-38%. Reintroducing a second functional allele, respectively, to all three mutants restored virulence. Heterozygous deletion of SLC1, a homolog of 1-acylglycerol-3-phosphate O-acyltransferases, did not significantly reduce virulence. Electrospray ionization tandem mass spectrometry analysis of phospholipid composition followed by principal component analysis identified comprehensive changes in the LRO1 and CHO1 deletion heterozygotes. Strikingly (p < 0.001), univariate comparisons found that both deletion heterozygotes had 20% more phosphatidylinositol, 75% less lysophosphatidylcholine, and 35% less lysophosphatidylethanolamine compared to wild type. Heterozygous deletion of LPT1 also significantly increased phosphatidylinositol abundance. No growth phenotype, including filamentation, was affected by any mutation. Together, these data predict that even partial pharmacological inhibition of Lro1p, Cho1p, and Lpt1p will limit C. albicans virulence through altering phospholipid composition.
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13
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Elkabti AB, Issi L, Rao RP. Caenorhabditis elegans as a Model Host to Monitor the Candida Infection Processes. J Fungi (Basel) 2018; 4:E123. [PMID: 30405043 PMCID: PMC6309157 DOI: 10.3390/jof4040123] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 10/31/2018] [Accepted: 11/01/2018] [Indexed: 02/07/2023] Open
Abstract
C. elegans has several advantages as an experimental host for the study of infectious diseases. Worms are easily maintained and propagated on bacterial lawns. The worms can be frozen for long term storage and still maintain viability years later. Their short generation time and large brood size of thousands of worms grown on a single petri dish, makes it relatively easy to maintain at a low cost. The typical wild type adult worm grows to approximately 1.5 mm in length and are transparent, allowing for the identification of several internal organs using an affordable dissecting microscope. A large collection of loss of function mutant strains are readily available from the C. elegans genetic stock center, making targeted genetic studies in the nematode possible. Here we describe ways in which this facile model host has been used to study Candida albicans, an opportunistic fungal pathogen that poses a serious public health threat.
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Affiliation(s)
| | - Luca Issi
- Worcester Polytechnic Institute, Worcester, MA 01609, USA.
| | - Reeta P Rao
- Worcester Polytechnic Institute, Worcester, MA 01609, USA.
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14
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Redox Signaling of NADPH Oxidases Regulates Oxidative Stress Responses, Immunity and Aging. Antioxidants (Basel) 2018; 7:antiox7100130. [PMID: 30274229 PMCID: PMC6210377 DOI: 10.3390/antiox7100130] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Revised: 09/25/2018] [Accepted: 09/26/2018] [Indexed: 12/14/2022] Open
Abstract
An accumulating body of evidence suggests that transient or physiological reactive oxygen species (ROS) generated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidases act as a redox signal to re-establish homeostasis. The capacity to re-establish homeostasis progressively declines during aging but is maintained in long-lived animals to promote healthy aging. In the model organism Caenorhabditis elegans, ROS generated by dual oxidases (Duox) are important for extracellular matrix integrity, pathogen defense, oxidative stress resistance, and longevity. The Duox enzymatic activity is tightly regulated and under cellular control. Developmental molting cycles, pathogen infections, toxins, mitochondrial-derived ROS, drugs, and small GTPases (e.g., RHO-1) can activate Duox (BLI-3) to generate ROS, whereas NADPH oxidase inhibitors and negative regulators, such as MEMO-1, can inhibit Duox from generating ROS. Three mechanisms-of-action have been discovered for the Duox/BLI-3-generated ROS: (1) enzymatic activity to catalyze crosslinking of free tyrosine ethyl ester in collagen bundles to stabilize extracellular matrices, (2) high ROS bursts/levels to kill pathogens, and (3) redox signaling activating downstream kinase cascades to transcription factors orchestrating oxidative stress and immunity responses to re-establish homeostasis. Although Duox function at the cell surface is well established, recent genetic and biochemical data also suggests a novel role for Duoxs at the endoplasmic reticulum membrane to control redox signaling. Evidence underlying these mechanisms initiated by ROS from NADPH oxidases, and their relevance for human aging, are discussed in this review. Appropriately controlling NADPH oxidase activity for local and physiological redox signaling to maintain cellular homeostasis might be a therapeutic strategy to promote healthy aging.
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15
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Koch B, Tucey TM, Lo TL, Novakovic S, Boag P, Traven A. The Mitochondrial GTPase Gem1 Contributes to the Cell Wall Stress Response and Invasive Growth of Candida albicans. Front Microbiol 2017; 8:2555. [PMID: 29326680 PMCID: PMC5742345 DOI: 10.3389/fmicb.2017.02555] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 12/08/2017] [Indexed: 01/27/2023] Open
Abstract
The interactions of mitochondria with the endoplasmic reticulum (ER) are crucial for maintaining proper mitochondrial morphology, function and dynamics. This enables cells to utilize their mitochondria optimally for energy production and anabolism, and it further provides for metabolic control over developmental decisions. In fungi, a key mechanism by which ER and mitochondria interact is via a membrane tether, the protein complex ERMES (ER-Mitochondria Encounter Structure). In the model yeast Saccharomyces cerevisiae, the mitochondrial GTPase Gem1 interacts with ERMES, and it has been proposed to regulate its activity. Here we report on the first characterization of Gem1 in a human fungal pathogen. We show that in Candida albicans Gem1 has a dominant role in ensuring proper mitochondrial morphology, and our data is consistent with Gem1 working with ERMES in this role. Mitochondrial respiration and steady state cellular phospholipid homeostasis are not impacted by inactivation of GEM1 in C. albicans. There are two major virulence-related consequences of disrupting mitochondrial morphology by GEM1 inactivation: C. albicans becomes hypersusceptible to cell wall stress, and is unable to grow invasively. In the gem1Δ/Δ mutant, it is specifically the invasive capacity of hyphae that is compromised, not the ability to transition from yeast to hyphal morphology, and this phenotype is shared with ERMES mutants. As a consequence of the hyphal invasion defect, the gem1Δ/Δ mutant is drastically hypovirulent in the worm infection model. Activation of the mitogen activated protein (MAP) kinase Cek1 is reduced in the gem1Δ/Δ mutant, and this function could explain both the susceptibility to cell wall stress and lack of invasive growth. This result establishes a new, respiration-independent mechanism of mitochondrial control over stress signaling and hyphal functions in C. albicans. We propose that ER-mitochondria interactions and the ER-Mitochondria Organizing Network (ERMIONE) play important roles in adaptive responses in fungi, in particular cell surface-related mechanisms that drive invasive growth and stress responsive behaviors that support fungal pathogenicity.
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Affiliation(s)
- Barbara Koch
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Timothy M Tucey
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Tricia L Lo
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Stevan Novakovic
- Development and Stem Cells Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Peter Boag
- Development and Stem Cells Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Ana Traven
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
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16
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Issi L, Rioux M, Rao R. The Nematode Caenorhabditis Elegans - A Versatile In Vivo Model to Study Host-microbe Interactions. J Vis Exp 2017. [PMID: 29155731 DOI: 10.3791/56487] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
We demonstrate a method using Caenorhabditis elegans as a model host to study microbial interaction. Microbes are introduced via the diet making the intestine the primary location for disease. The nematode intestine structurally and functionally mimics mammalian intestines and is transparent making it amenable to microscopic study of colonization. Here we show that pathogens can cause disease and death. We are able to identify microbial mutants that show altered virulence. Its conserved innate response to biotic stresses makes C. elegans an excellent system to probe facets of host innate immune interactions. We show that hosts with mutations in the dual oxidase gene cannot produce reactive oxygen species and are unable to resist microbial insult. We further demonstrate the versatility of the presented survival assay by showing that it can be used to study the effects of inhibitors of microbial growth. This assay may also be used to discover fungal virulence factors as targets for the development of novel antifungal agents, as well as provide an opportunity to further uncover host-microbe interactions. The design of this assay lends itself well to high throughput whole-genome screens, while the ability to cryo-preserve worms for future use makes it a cost-effective and attractive whole animal model to study.
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Affiliation(s)
- Luca Issi
- Biology and Biotechnology, Worcester Polytechnic Institute
| | - Meredith Rioux
- Biology and Biotechnology, Worcester Polytechnic Institute
| | - Reeta Rao
- Biology and Biotechnology, Worcester Polytechnic Institute;
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17
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Brown AJP, Cowen LE, di Pietro A, Quinn J. Stress Adaptation. Microbiol Spectr 2017; 5:10.1128/microbiolspec.FUNK-0048-2016. [PMID: 28721857 PMCID: PMC5701650 DOI: 10.1128/microbiolspec.funk-0048-2016] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Indexed: 01/21/2023] Open
Abstract
Fungal species display an extraordinarily diverse range of lifestyles. Nevertheless, the survival of each species depends on its ability to sense and respond to changes in its natural environment. Environmental changes such as fluctuations in temperature, water balance or pH, or exposure to chemical insults such as reactive oxygen and nitrogen species exert stresses that perturb cellular homeostasis and cause molecular damage to the fungal cell. Consequently, fungi have evolved mechanisms to repair this damage, detoxify chemical insults, and restore cellular homeostasis. Most stresses are fundamental in nature, and consequently, there has been significant evolutionary conservation in the nature of the resultant responses across the fungal kingdom and beyond. For example, heat shock generally induces the synthesis of chaperones that promote protein refolding, antioxidants are generally synthesized in response to an oxidative stress, and osmolyte levels are generally increased following a hyperosmotic shock. In this article we summarize the current understanding of these and other stress responses as well as the signaling pathways that regulate them in the fungi. Model yeasts such as Saccharomyces cerevisiae are compared with filamentous fungi, as well as with pathogens of plants and humans. We also discuss current challenges associated with defining the dynamics of stress responses and with the elaboration of fungal stress adaptation under conditions that reflect natural environments in which fungal cells may be exposed to different types of stresses, either sequentially or simultaneously.
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Affiliation(s)
- Alistair J P Brown
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, United Kingdom
| | - Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Antonio di Pietro
- Departamento de Genética, Universidad de Córdoba, Campus de Rabanales, Edificio Gregor Mendel C5, 14071 Córdoba, Spain
| | - Janet Quinn
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
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18
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Miranda-Vizuete A, Veal EA. Caenorhabditis elegans as a model for understanding ROS function in physiology and disease. Redox Biol 2016; 11:708-714. [PMID: 28193593 PMCID: PMC5304259 DOI: 10.1016/j.redox.2016.12.020] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 12/19/2016] [Indexed: 01/05/2023] Open
Abstract
ROS (reactive oxygen species) are potentially damaging by-products of aerobic metabolism which, unchecked, can have detrimental effects on cell function. However, it is now widely accepted that, at physiological levels, certain ROS play important roles in cell signaling, acting as second messengers to regulate cell choices that contribute to the development, adaptation and survival of plants and animals. Despite important recent advances in the biochemical tools available to study redox-signaling, the molecular mechanisms underlying most of these responses remain poorly understood, particularly in multicellular organisms. As we will review here, C. elegans has emerged as a powerful animal model to elucidate these and other aspects of redox biology.
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Affiliation(s)
- Antonio Miranda-Vizuete
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41013 Sevilla, Spain.
| | - Elizabeth A Veal
- Institute for Cell and Molecular Biosciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK; Institute for Ageing, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
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19
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Zinc Cluster Transcription Factors Alter Virulence in Candida albicans. Genetics 2016; 205:559-576. [PMID: 27932543 DOI: 10.1534/genetics.116.195024] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 11/16/2016] [Indexed: 11/18/2022] Open
Abstract
Almost all humans are colonized with Candida albicans However, in immunocompromised individuals, this benign commensal organism becomes a serious, life-threatening pathogen. Here, we describe and analyze the regulatory networks that modulate innate responses in the host niches. We identified Zcf15 and Zcf29, two Zinc Cluster transcription Factors (ZCF) that are required for C. albicans virulence. Previous sequence analysis of clinical C. albicans isolates from immunocompromised patients indicates that both ZCF genes diverged during clonal evolution. Using in vivo animal models, ex vivo cell culture methods, and in vitro sensitivity assays, we demonstrate that knockout mutants of both ZCF15 and ZCF29 are hypersensitive to reactive oxygen species (ROS), suggesting they help neutralize the host-derived ROS produced by phagocytes, as well as establish a sustained infection in vivo Transcriptomic analysis of mutants under resting conditions where cells were not experiencing oxidative stress revealed a large network that control macro and micronutrient homeostasis, which likely contributes to overall pathogen fitness in host niches. Under oxidative stress, both transcription factors regulate a separate set of genes involved in detoxification of ROS and down-regulating ribosome biogenesis. ChIP-seq analysis, which reveals vastly different binding partners for each transcription factor (TF) before and after oxidative stress, further confirms these results. Furthermore, the absence of a dominant binding motif likely facilitates their mobility, and supports the notion that they represent a recent expansion of the ZCF family in the pathogenic Candida species. Our analyses provide a framework for understanding new aspects of the interface between C. albicans and host defense response, and extends our understanding of how complex cell behaviors are linked to the evolution of TFs.
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21
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The Candida albicans fimbrin Sac6 regulates oxidative stress response (OSR) and morphogenesis at the transcriptional level. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:2255-66. [DOI: 10.1016/j.bbamcr.2016.06.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 05/27/2016] [Accepted: 06/02/2016] [Indexed: 12/30/2022]
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22
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Mechanisms Underlying the Delayed Activation of the Cap1 Transcription Factor in Candida albicans following Combinatorial Oxidative and Cationic Stress Important for Phagocytic Potency. mBio 2016; 7:e00331. [PMID: 27025253 PMCID: PMC4817257 DOI: 10.1128/mbio.00331-16] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Following phagocytosis, microbes are exposed to an array of antimicrobial weapons that include reactive oxygen species (ROS) and cationic fluxes. This is significant as combinations of oxidative and cationic stresses are much more potent than the corresponding single stresses, triggering the synergistic killing of the fungal pathogen Candida albicans by “stress pathway interference.” Previously we demonstrated that combinatorial oxidative plus cationic stress triggers a dramatic increase in intracellular ROS levels compared to oxidative stress alone. Here we show that activation of Cap1, the major regulator of antioxidant gene expression in C. albicans, is significantly delayed in response to combinatorial stress treatments and to high levels of H2O2. Cap1 is normally oxidized in response to H2O2; this masks the nuclear export sequence, resulting in the rapid nuclear accumulation of Cap1 and the induction of Cap1-dependent genes. Here we demonstrate that following exposure of cells to combinatorial stress or to high levels of H2O2, Cap1 becomes trapped in a partially oxidized form, Cap1OX-1. Notably, Cap1-dependent gene expression is not induced when Cap1 is in this partially oxidized form. However, while Cap1OX-1 readily accumulates in the nucleus and binds to target genes following high-H2O2 stress, the nuclear accumulation of Cap1OX-1 following combinatorial H2O2 and NaCl stress is delayed due to a cationic stress-enhanced interaction with the Crm1 nuclear export factor. These findings define novel mechanisms that delay activation of the Cap1 transcription factor, thus preventing the rapid activation of the stress responses vital for the survival of C. albicans within the host. Combinatorial stress-mediated synergistic killing represents a new unchartered area in the field of stress signaling. This phenomenon contrasts starkly with “stress cross-protection,” where exposure to one stress protects against subsequent exposure to a different stress. Previously we demonstrated that the pathogen Candida albicans is acutely sensitive to combinations of cationic and oxidative stresses, because the induction of H2O2-responsive genes is blocked in the presence of cationic stress. We reveal that this is due to novel mechanisms that delay activation of the Cap1 AP-1-like transcription factor, the major regulator of the H2O2-induced regulon. Cap1 becomes trapped in a partially oxidized form following simultaneous exposure to oxidative and cationic stresses. In addition, cationic stress promotes the interaction of Cap1 with the Crm1 nuclear export factor, thus inhibiting its nuclear accumulation. These mechanisms probably explain the potency of neutrophils, which employ multiple stresses to kill fungal pathogens.
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Gruber J, Chen CB, Fong S, Ng LF, Teo E, Halliwell B. Caenorhabditis elegans: What We Can and Cannot Learn from Aging Worms. Antioxid Redox Signal 2015; 23:256-79. [PMID: 25544992 DOI: 10.1089/ars.2014.6210] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
SIGNIFICANCE The nematode Caenorhabditis elegans is a widely used model organism for research into aging. However, nematodes diverged from other animals between 600 and 1300 million years ago. Beyond the intuitive impression that some aspects of aging appear to be universal, is there evidence that insights into the aging process of nematodes may be applicable to humans? RECENT ADVANCES There have been a number of results in nematodes that appear to contradict long-held beliefs about mechanisms and causes of aging. For example, ablation of several key antioxidant systems has often failed to result in lifespan shortening in C. elegans. CRITICAL ISSUES While it is clear that some central signaling pathways controlling lifespan are broadly conserved across large evolutionary distances, it is less clear to what extent downstream molecular mechanisms of aging are conserved. In this review we discuss the biology of C. elegans and mammals in the context of aging and age-dependent diseases. We consider evidence from studies that attempt to investigate basic, possibly conserved mechanisms of aging especially in the context of the free radical theory of aging. Practical points, such as the need for blinding of lifespan studies and for appropriate biomarkers, are also considered. FUTURE DIRECTIONS As data on the aging process(es) in different organisms increase, it is becoming increasingly clear that there are both conserved (public) and private aspects to aging. It is important to explore the dividing lines between these two aspects and to be aware of the large gray areas in-between.
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Affiliation(s)
- Jan Gruber
- 1 Department of Biochemistry, National University of Singapore , Singapore, Singapore .,2 Yale-NUS College , Singapore, Singapore
| | - Ce-Belle Chen
- 3 Department of Physics, National University of Singapore , Singapore, Singapore
| | - Sheng Fong
- 4 Duke-NUS Graduate Medical School , Singapore, Singapore
| | - Li Fang Ng
- 1 Department of Biochemistry, National University of Singapore , Singapore, Singapore
| | - Emelyne Teo
- 1 Department of Biochemistry, National University of Singapore , Singapore, Singapore
| | - Barry Halliwell
- 1 Department of Biochemistry, National University of Singapore , Singapore, Singapore
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Tillmann AT, Strijbis K, Cameron G, Radmaneshfar E, Thiel M, Munro CA, MacCallum DM, Distel B, Gow NAR, Brown AJP. Contribution of Fdh3 and Glr1 to Glutathione Redox State, Stress Adaptation and Virulence in Candida albicans. PLoS One 2015; 10:e0126940. [PMID: 26039593 PMCID: PMC4454436 DOI: 10.1371/journal.pone.0126940] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 04/09/2015] [Indexed: 01/04/2023] Open
Abstract
The major fungal pathogen of humans, Candida albicans, is exposed to reactive nitrogen and oxygen species following phagocytosis by host immune cells. In response to these toxins, this fungus activates potent anti-stress responses that include scavenging of reactive nitrosative and oxidative species via the glutathione system. Here we examine the differential roles of two glutathione recycling enzymes in redox homeostasis, stress adaptation and virulence in C. albicans: glutathione reductase (Glr1) and the S-nitrosoglutathione reductase (GSNOR), Fdh3. We show that the NADPH-dependent Glr1 recycles GSSG to GSH, is induced in response to oxidative stress and is required for resistance to macrophage killing. GLR1 deletion increases the sensitivity of C. albicans cells to H2O2, but not to formaldehyde or NO. In contrast, Fdh3 detoxifies GSNO to GSSG and NH3, and FDH3 inactivation delays NO adaptation and increases NO sensitivity. C. albicans fdh3⎔ cells are also sensitive to formaldehyde, suggesting that Fdh3 also contributes to formaldehyde detoxification. FDH3 is induced in response to nitrosative, oxidative and formaldehyde stress, and fdh3Δ cells are more sensitive to killing by macrophages. Both Glr1 and Fdh3 contribute to virulence in the Galleria mellonella and mouse models of systemic infection. We conclude that Glr1 and Fdh3 play differential roles during the adaptation of C. albicans cells to oxidative, nitrosative and formaldehyde stress, and hence during the colonisation of the host. Our findings emphasise the importance of the glutathione system and the maintenance of intracellular redox homeostasis in this major pathogen.
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Affiliation(s)
- Anna T Tillmann
- Aberdeen Fungal Group, School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Karin Strijbis
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Gary Cameron
- Division of Applied Medicine, Mass Spectrometry Section, University of Aberdeen, Aberdeen, United Kingdom
| | - Elahe Radmaneshfar
- Institute for Complex Systems and Mathematical Biology, SUPA, University of Aberdeen, Aberdeen, United Kingdom
| | - Marco Thiel
- Institute for Complex Systems and Mathematical Biology, SUPA, University of Aberdeen, Aberdeen, United Kingdom
| | - Carol A Munro
- Aberdeen Fungal Group, School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Donna M MacCallum
- Aberdeen Fungal Group, School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Ben Distel
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Neil A R Gow
- Aberdeen Fungal Group, School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Alistair J P Brown
- Aberdeen Fungal Group, School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
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Oxidative stress responses in the human fungal pathogen, Candida albicans. Biomolecules 2015; 5:142-65. [PMID: 25723552 PMCID: PMC4384116 DOI: 10.3390/biom5010142] [Citation(s) in RCA: 166] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 02/11/2015] [Accepted: 02/12/2015] [Indexed: 02/07/2023] Open
Abstract
Candida albicans is a major fungal pathogen of humans, causing approximately 400,000 life-threatening systemic infections world-wide each year in severely immunocompromised patients. An important fungicidal mechanism employed by innate immune cells involves the generation of toxic reactive oxygen species (ROS), such as superoxide and hydrogen peroxide. Consequently, there is much interest in the strategies employed by C. albicans to evade the oxidative killing by macrophages and neutrophils. Our understanding of how C. albicans senses and responds to ROS has significantly increased in recent years. Key findings include the observations that hydrogen peroxide triggers the filamentation of this polymorphic fungus and that a superoxide dismutase enzyme with a novel mode of action is expressed at the cell surface of C. albicans. Furthermore, recent studies have indicated that combinations of the chemical stresses generated by phagocytes can actively prevent C. albicans oxidative stress responses through a mechanism termed the stress pathway interference. In this review, we present an up-date of our current understanding of the role and regulation of oxidative stress responses in this important human fungal pathogen.
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Ford CB, Funt JM, Abbey D, Issi L, Guiducci C, Martinez DA, Delorey T, Li BY, White TC, Cuomo C, Rao RP, Berman J, Thompson DA, Regev A. The evolution of drug resistance in clinical isolates of Candida albicans. eLife 2015; 4:e00662. [PMID: 25646566 PMCID: PMC4383195 DOI: 10.7554/elife.00662] [Citation(s) in RCA: 189] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 12/18/2014] [Indexed: 12/31/2022] Open
Abstract
Candida albicans is both a member of the healthy human microbiome
and a major pathogen in immunocompromised individuals. Infections are typically
treated with azole inhibitors of ergosterol biosynthesis often leading to drug
resistance. Studies in clinical isolates have implicated multiple mechanisms in
resistance, but have focused on large-scale aberrations or candidate genes, and do
not comprehensively chart the genetic basis of adaptation. Here, we leveraged
next-generation sequencing to analyze 43 isolates from 11 oral candidiasis patients.
We detected newly selected mutations, including single-nucleotide polymorphisms
(SNPs), copy-number variations and loss-of-heterozygosity (LOH) events. LOH events
were commonly associated with acquired resistance, and SNPs in 240 genes may be
related to host adaptation. Conversely, most aneuploidies were transient and did not
correlate with drug resistance. Our analysis also shows that isolates also varied in
adherence, filamentation, and virulence. Our work reveals new molecular mechanisms
underlying the evolution of drug resistance and host adaptation. DOI:http://dx.doi.org/10.7554/eLife.00662.001 Nearly all humans are infected with the fungus Candida albicans. In
most people, the infection does not produce any symptoms because their immune system
is able to counteract the fungus' attempts to spread around the body. However, if the
balance between fungal attack and body defence fails, the fungus is able to spread,
which can lead to serious disease that is fatal in 42% of cases. How does C. albicans outcompete the body's defences to cause
disease? This is a pertinent question because the most effective antifungal
medicines—including the drug fluconazole—do not kill the fungus; they
only stop it from growing. This gives the fungus time to develop resistance to the
drug by becoming able to quickly replace the fungal proteins the drug destroys, or to
efficiently remove the drug from its cells. In this study, Ford et al. studied the changes that occur in the DNA of C.
albicans over time in patients who are being treated with fluconazole.
Ford et al. took 43 samples of C. albicans from 11 patients with
weakened immune systems. The experiments show that the fungus samples collected early
on were more sensitive to the drug than the samples collected later. In most cases, the genetic data suggest that the infections begin with a single
fungal cell; the cells in the later samples are its offspring. Despite this, there is
a lot of genetic variation between samples from the same patient, which indicates
that the fungus is under pressure to become more resistant to the drug. There were
240 genes—including those that can alter the surface on the fungus cells to
make it better at evading the host immune system—in which small changes
occurred over time in three or more patients. Laboratory tests revealed that many of
these genes are likely important for the fungus to survive in an animal host in the
presence of the drug. C. albicans cells usually have two genetically distinct copies of
every gene. Ford et al. found that for some genes—including some that make
surface components or are involved in expelling drugs from cells—the loss of
genetic information from one copy, so that both copies become identical, is linked to
resistance to fluconazole. However, the gain of whole or partial
chromosomes—which contain large numbers of genes—is not linked to
resistance, but may provide additional genetic material for generating diversity in
the yeast population that may help the cells to evolve resistance in the future. These experiments have identified many new candidate genes that are important for
drug resistance and evading the host immune system, and which could be used to guide
the development of new therapeutics to treat these life-threatening infections. DOI:http://dx.doi.org/10.7554/eLife.00662.002
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Affiliation(s)
- Christopher B Ford
- Department of Biology, Broad Institute of MIT and Harvard, Cambridge, United States
| | - Jason M Funt
- Department of Biology, Broad Institute of MIT and Harvard, Cambridge, United States
| | - Darren Abbey
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, United States
| | - Luca Issi
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, United States
| | | | | | - Toni Delorey
- Broad Institute of MIT and Harvard, Cambridge, United States
| | - Bi Yu Li
- Broad Institute of MIT and Harvard, Cambridge, United States
| | - Theodore C White
- School of Biological Sciences, University of Missouri at Kansas City, Kansas City, United States
| | - Christina Cuomo
- Broad Institute of MIT and Harvard, Cambridge, United States
| | - Reeta P Rao
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, United States
| | - Judith Berman
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, United States
| | - Dawn A Thompson
- Broad Institute of MIT and Harvard, Cambridge, United States
| | - Aviv Regev
- Department of Biology, Broad Institute of MIT and Harvard, Cambridge, United States
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Cryptococcus neoformans Yap1 is required for normal fluconazole and oxidative stress resistance. Fungal Genet Biol 2014; 74:1-9. [PMID: 25445311 DOI: 10.1016/j.fgb.2014.10.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Revised: 10/07/2014] [Accepted: 10/27/2014] [Indexed: 11/20/2022]
Abstract
Cryptococcus neoformans is a pathogen that is the most common cause of fungal meningitis. As with most fungal pathogens, the most prevalent clinical antifungal used to treat Cryptococcosis is orally administered fluconazole. Resistance to this antifungal is an increasing concern in treatment of fungal disease in general. Our knowledge of the specific determinants involved in fluconazole resistance in Cryptococcus is limited. Here we report the identification of an important genetic determinant of fluconazole resistance in C. neoformans that encodes a basic region-leucine zipper transcription factor homologous to Saccharomyces cerevisiae Yap1. Expression of a codon-optimized form of the Cn YAP1 cDNA in S. cerevisiae complemented defects caused by loss of the endogenous S. cerevisiae YAP1 gene and activated transcription from a reporter gene construct. Mutant strains of C. neoformans lacking YAP1 were hypersensitive to a range of oxidative stress agents but importantly also to fluconazole. Loss of Yap1 homologues from other fungal pathogens like Candida albicans or Aspergillus fumigatus was previously found to cause oxidant hypersensitivity but had no detectable effect on fluconazole resistance. Our data provide evidence for a unique biological role of Yap1 in wild-type fluconazole resistance in C. neoformans.
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28
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Enhanced therapeutic efficacy of lipophilic amphotericin B against Candida albicans with amphiphilic poly(N-isopropylacrylamide) nanogels. Macromol Res 2014. [DOI: 10.1007/s13233-014-2162-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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29
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Jiang C, Zhang S, Zhang Q, Tao Y, Wang C, Xu JR. FgSKN7 and FgATF1 have overlapping functions in ascosporogenesis, pathogenesis and stress responses in Fusarium graminearum. Environ Microbiol 2014; 17:1245-60. [PMID: 25040476 DOI: 10.1111/1462-2920.12561] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 06/28/2014] [Indexed: 11/30/2022]
Abstract
Fusarium head blight caused by Fusarium graminearum is one of the most destructive diseases of wheat and barley. Deoxynivalenol (DON) produced by the pathogen is an important mycotoxins and virulence factor. Because oxidative burst is a common defense response and reactive oxygen species (ROS) induces DON production, in this study, we characterized functional relationships of three stress-related transcription factor genes FgAP1, FgATF1 and FgSKN7. Although all of them played a role in tolerance to oxidative stress, deletion of FgAP1 or FgATF1 had no significant effect on DON production. In contrast, Fgskn7 mutants were reduced in DON production and defective in H2 O2 -induced TRI gene expression. The Fgap1 mutant had no detectable phenotype other than increased sensitivity to H2 O2 and Fgap1 Fgatf1 and Fgap1 Fgskn7 mutants lacked additional or more severe phenotypes than the single mutants. The Fgatf1, but not Fgskn7, mutant was significantly reduced in virulence and delayed in ascospore release. The Fgskn7 Fgatf1 double mutant had more severe defects in growth, conidiation and virulence than the Fgatf1 or Fgskn7 mutant. Instead of producing four-celled ascospores, it formed eight small, single-celled ascospores in each ascus. Therefore, FgSKN7 and FgATF1 must have overlapping functions in intracellular ROS signalling for growth, development and pathogenesis in F. graminearum.
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Affiliation(s)
- Cong Jiang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwestern A&F University, Yangling, Shaanxi, 712100, China; Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
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30
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Hogan D, Wheeler RT. The complex roles of NADPH oxidases in fungal infection. Cell Microbiol 2014; 16:1156-67. [PMID: 24905433 DOI: 10.1111/cmi.12320] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 05/27/2014] [Accepted: 05/29/2014] [Indexed: 12/21/2022]
Abstract
NADPH oxidases play key roles in immunity and inflammation that go beyond the production of microbicidal reactive oxygen species (ROS). The past decade has brought a new appreciation for the diversity of roles played by ROS in signalling associated with inflammation and immunity. NADPH oxidase activity affects disease outcome during infections by human pathogenic fungi, an important group of emerging and opportunistic pathogens that includes Candida, Aspergillus and Cryptococcus species. Here we review how alternative roles of NADPH oxidase activity impact fungal infection and how ROS signalling affects fungal physiology. Particular attention is paid to roles for NADPH oxidase in immune migration, immunoregulation in pulmonary infection, neutrophil extracellular trap formation, autophagy and inflammasome activity. These recent advances highlight the power and versatility of spatiotemporally controlled redox regulation in the context of infection, and point to a need to understand the molecular consequences of NADPH oxidase activity in the cell.
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Affiliation(s)
- Deborah Hogan
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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Harwood CG, Rao RP. Host pathogen relations: exploring animal models for fungal pathogens. Pathogens 2014; 3:549-62. [PMID: 25438011 PMCID: PMC4243428 DOI: 10.3390/pathogens3030549] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 06/18/2014] [Accepted: 06/23/2014] [Indexed: 01/21/2023] Open
Abstract
Pathogenic fungi cause superficial infections but pose a significant public health risk when infections spread to deeper tissues, such as the lung. Within the last three decades, fungi have been identified as the leading cause of nosocomial infections making them the focus of research. This review outlines the model systems such as the mouse, zebrafish larvae, flies, and nematodes, as well as ex vivo and in vitro systems available to study common fungal pathogens.
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Affiliation(s)
- Catherine G Harwood
- Biology and Biotechnology Department, Worcester Polytechnic University, Worcester, MA 01605, USA.
| | - Reeta P Rao
- Biology and Biotechnology Department, Worcester Polytechnic University, Worcester, MA 01605, USA.
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Jiménez-López C, Lorenz MC. Fungal immune evasion in a model host-pathogen interaction: Candida albicans versus macrophages. PLoS Pathog 2013; 9:e1003741. [PMID: 24278014 PMCID: PMC3836912 DOI: 10.1371/journal.ppat.1003741] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Claudia Jiménez-López
- Department of Microbiology and Molecular Genetics and the Graduate School of Biomedical Sciences, the University of Texas Health Science Center, Houston, Texas, United States of America
| | - Michael C. Lorenz
- Department of Microbiology and Molecular Genetics and the Graduate School of Biomedical Sciences, the University of Texas Health Science Center, Houston, Texas, United States of America
- * E-mail:
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NADPH oxidase-driven phagocyte recruitment controls Candida albicans filamentous growth and prevents mortality. PLoS Pathog 2013; 9:e1003634. [PMID: 24098114 PMCID: PMC3789746 DOI: 10.1371/journal.ppat.1003634] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 08/03/2013] [Indexed: 01/17/2023] Open
Abstract
Candida albicans is a human commensal and clinically important fungal pathogen that grows as both yeast and hyphal forms during human, mouse and zebrafish infection. Reactive oxygen species (ROS) produced by NADPH oxidases play diverse roles in immunity, including their long-appreciated function as microbicidal oxidants. Here we demonstrate a non-traditional mechanistic role of NADPH oxidase in promoting phagocyte chemotaxis and intracellular containment of fungi to limit filamentous growth. We exploit the transparent zebrafish model to show that failed NADPH oxidase-dependent phagocyte recruitment to C. albicans in the first four hours post-infection permits fungi to germinate extracellularly and kill the host. We combine chemical and genetic tools with high-resolution time-lapse microscopy to implicate both phagocyte oxidase and dual-specific oxidase in recruitment, suggesting that both myeloid and non-myeloid cells promote chemotaxis. We show that early non-invasive imaging provides a robust tool for prognosis, strongly connecting effective early immune response with survival. Finally, we demonstrate a new role of a key regulator of the yeast-to-hyphal switching program in phagocyte-mediated containment, suggesting that there are species-specific methods for modulation of NADPH oxidase-independent immune responses. These novel links between ROS-driven chemotaxis and fungal dimorphism expand our view of a key host defense mechanism and have important implications for pathogenesis. Over 45 years ago chronic granulomatous disease (CGD) was ascribed to a failure of neutrophils to mount a respiratory burst, and it is now known to result from primary genetic deficiencies in the phagocyte NADPH oxidase complex. Recent work suggests that reactive oxygen species produced by NADPH oxidases have other important functions as diverse as maturing hormones and promoting protein kinase signal transduction. Candida albicans is an opportunistic pathogen that preys on immunocompromised patients to cause lethal candidemia. We used the transparent zebrafish larva to describe a novel function of both phagocyte oxidase and dual-specific NADPH oxidase in directing phagocyte recruitment to C. albicans infection foci. We demonstrate that NADPH oxidase-dependent attraction of neutrophils and macrophages is instrumental in effective containment of yeast within phagocytes, which prevents the yeast-to-hyphal morphogenetic switch and limits mortality. Remarkably, when the fungal morphogenetic switch is prevented by mutation, NADPH oxidase activity is no longer required for effective fungal containment. Our study suggests that defects in CGD may extend beyond reduced microbial killing by superoxide to include impairment of chemotaxis, and provide a basis for exploring this alternative function in mammals.
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Chemical screening identifies filastatin, a small molecule inhibitor of Candida albicans adhesion, morphogenesis, and pathogenesis. Proc Natl Acad Sci U S A 2013; 110:13594-9. [PMID: 23904484 DOI: 10.1073/pnas.1305982110] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Infection by pathogenic fungi, such as Candida albicans, begins with adhesion to host cells or implanted medical devices followed by biofilm formation. By high-throughput phenotypic screening of small molecules, we identified compounds that inhibit adhesion of C. albicans to polystyrene. Our lead candidate compound also inhibits binding of C. albicans to cultured human epithelial cells, the yeast-to-hyphal morphological transition, induction of the hyphal-specific HWP1 promoter, biofilm formation on silicone elastomers, and pathogenesis in a nematode infection model as well as alters fungal morphology in a mouse mucosal infection assay. We term this compound filastatin based on its strong inhibition of filamentation, and we use chemical genetic experiments to show that it acts downstream of multiple signaling pathways. These studies show that high-throughput functional assays targeting fungal adhesion can provide chemical probes for study of multiple aspects of fungal pathogenesis.
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