1
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Zhang FY, Lian N, Li M. Macrophage pyroptosis induced by Candida albicans. Pathog Dis 2024; 82:ftae003. [PMID: 38499444 PMCID: PMC11162155 DOI: 10.1093/femspd/ftae003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 10/21/2023] [Accepted: 03/15/2024] [Indexed: 03/20/2024] Open
Abstract
Candida albicans (C. albicans) is a prevalent opportunistic pathogen that causes mucocutaneous and systemic infections, particularly in immunocompromised individuals. Macrophages play a crucial role in eliminating C. albicans in local and bloodstream contexts, while also regulating antifungal immune responses. However, C. albicans can induce macrophage lysis through pyroptosis, a type of regulated cell death. This process can enable C. albicans to escape from immune cells and trigger the release of IL-1β and IL-18, which can impact both the host and the pathogen. Nevertheless, the mechanisms by which C. albicans triggers pyroptosis in macrophages and the key factors involved in this process remain unclear. In this review, we will explore various factors that may influence or trigger pyroptosis in macrophages induced by C. albicans, such as hypha, ergosterol, cell wall remodeling, and other virulence factors. We will also examine the possible immune response following macrophage pyroptosis.
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Affiliation(s)
- Feng-yuan Zhang
- Hospital for Skin Diseases, Institute of Dermatology,Chinese Academy of Medical Sciences & Peking Union Medical College, 12th. JiangWangmiao street, Nanjing, 210042, China
| | - Ni Lian
- Hospital for Skin Diseases, Institute of Dermatology,Chinese Academy of Medical Sciences & Peking Union Medical College, 12th. JiangWangmiao street, Nanjing, 210042, China
| | - Min Li
- Hospital for Skin Diseases, Institute of Dermatology,Chinese Academy of Medical Sciences & Peking Union Medical College, 12th. JiangWangmiao street, Nanjing, 210042, China
- Center for Global Health, School of Public Health, Nanjing Medical University, 101st. LongMian Avenue, Nanjing, 211166, China
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2
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Weerasinghe H, Simm C, Djajawi TM, Tedja I, Lo TL, Simpson DS, Shasha D, Mizrahi N, Olivier FAB, Speir M, Lawlor KE, Ben-Ami R, Traven A. Candida auris uses metabolic strategies to escape and kill macrophages while avoiding robust activation of the NLRP3 inflammasome response. Cell Rep 2023; 42:112522. [PMID: 37204928 DOI: 10.1016/j.celrep.2023.112522] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 03/28/2023] [Accepted: 05/01/2023] [Indexed: 05/21/2023] Open
Abstract
Metabolic adaptations regulate the response of macrophages to infection. The contributions of metabolism to macrophage interactions with the emerging fungal pathogen Candida auris are poorly understood. Here, we show that C. auris-infected macrophages undergo immunometabolic reprogramming and increase glycolysis but fail to activate a strong interleukin (IL)-1β cytokine response or curb C. auris growth. Further analysis shows that C. auris relies on its own metabolic capacity to escape from macrophages and proliferate in vivo. Furthermore, C. auris kills macrophages by triggering host metabolic stress through glucose starvation. However, despite causing macrophage cell death, C. auris does not trigger robust activation of the NLRP3 inflammasome. Consequently, inflammasome-dependent responses remain low throughout infection. Collectively, our findings show that C. auris uses metabolic regulation to eliminate macrophages while remaining immunologically silent to ensure its own survival. Thus, our data suggest that host and pathogen metabolism could represent therapeutic targets for C. auris infections.
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Affiliation(s)
- Harshini Weerasinghe
- Infection Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; Centre to Impact AMR, Monash University, Clayton, VIC 3800, Australia
| | - Claudia Simm
- Infection Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; Centre to Impact AMR, Monash University, Clayton, VIC 3800, Australia
| | - Tirta Mario Djajawi
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC 3168, Australia; Department of Molecular and Translational Science, Monash University, Clayton, VIC 3168, Australia
| | - Irma Tedja
- Infection Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; Centre to Impact AMR, Monash University, Clayton, VIC 3800, Australia
| | - Tricia L Lo
- Infection Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; Centre to Impact AMR, Monash University, Clayton, VIC 3800, Australia
| | - Daniel S Simpson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; The Department of Medical Biology, University of Melbourne, Parkville, VIC 3010, Australia
| | - David Shasha
- Infectious Diseases Unit, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel; Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Naama Mizrahi
- Infectious Diseases Unit, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel
| | - Françios A B Olivier
- Infection Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; Centre to Impact AMR, Monash University, Clayton, VIC 3800, Australia; The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia
| | - Mary Speir
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC 3168, Australia; Department of Molecular and Translational Science, Monash University, Clayton, VIC 3168, Australia
| | - Kate E Lawlor
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC 3168, Australia; Department of Molecular and Translational Science, Monash University, Clayton, VIC 3168, Australia
| | - Ronen Ben-Ami
- Infectious Diseases Unit, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel; Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ana Traven
- Infection Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; Centre to Impact AMR, Monash University, Clayton, VIC 3800, Australia.
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3
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Okamoto M, Nakano K, Takahashi-Nakaguchi A, Sasamoto K, Yamaguchi M, Teixeira MC, Chibana H. In Candida glabrata, ERMES Component GEM1 Controls Mitochondrial Morphology, mtROS, and Drug Efflux Pump Expression, Resulting in Azole Susceptibility. J Fungi (Basel) 2023; 9:jof9020240. [PMID: 36836353 PMCID: PMC9965728 DOI: 10.3390/jof9020240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 02/05/2023] [Accepted: 02/08/2023] [Indexed: 02/16/2023] Open
Abstract
Mitochondrial dysfunction or morphological abnormalities in human pathogenic fungi are known to contribute to azole resistance; however, the underlying molecular mechanisms are unknown. In this study, we investigated the link between mitochondrial morphology and azole resistance in Candida glabrata, which is the second most common cause of human candidiasis worldwide. The ER-mitochondrial encounter structure (ERMES) complex is thought to play an important role in the mitochondrial dynamics necessary for mitochondria to maintain their function. Of the five components of the ERMES complex, deletion of GEM1 increased azole resistance. Gem1 is a GTPase that regulates the ERMES complex activity. Point mutations in GEM1 GTPase domains were sufficient to confer azole resistance. The cells lacking GEM1 displayed abnormalities in mitochondrial morphology, increased mtROS levels, and increased expression of azole drug efflux pumps encoded by CDR1 and CDR2. Interestingly, treatment with N-acetylcysteine (NAC), an antioxidant, reduced ROS production and the expression of CDR1 in Δgem1 cells. Altogether, the absence of Gem1 activity caused an increase in mitochondrial ROS concentration, leading to Pdr1-dependent upregulation of the drug efflux pump Cdr1, resulting in azole resistance.
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Affiliation(s)
- Michiyo Okamoto
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
| | - Keiko Nakano
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
| | | | - Kaname Sasamoto
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
| | - Masashi Yamaguchi
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
| | - Miguel Cacho Teixeira
- iBB—Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
| | - Hiroji Chibana
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
- Correspondence:
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4
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Olivier FAB, Hilsenstein V, Weerasinghe H, Weir A, Hughes S, Crawford S, Vince JE, Hickey MJ, Traven A. The escape of Candida albicans from macrophages is enabled by the fungal toxin candidalysin and two host cell death pathways. Cell Rep 2022; 40:111374. [PMID: 36130496 DOI: 10.1016/j.celrep.2022.111374] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 06/15/2022] [Accepted: 08/26/2022] [Indexed: 11/25/2022] Open
Abstract
The egress of Candida hyphae from macrophages facilitates immune evasion, but it also alerts macrophages to infection and triggers inflammation. To better define the mechanisms, here we develop an imaging assay to directly and dynamically quantify hyphal escape and correlate it to macrophage responses. The assay reveals that Candida escapes by using two pore-forming proteins to permeabilize macrophage membranes: the fungal toxin candidalysin and Nlrp3 inflammasome-activated Gasdermin D. Candidalysin plays a major role in escape, with Nlrp3 and Gasdermin D-dependent and -independent contributions. The inactivation of Nlrp3 does not reduce hyphal escape, and we identify ETosis via macrophage extracellular trap formation as an additional pathway facilitating hyphal escape. Suppressing hyphal escape does not reduce fungal loads, but it does reduce inflammatory activation. Our findings explain how Candida escapes from macrophages by using three strategies: permeabilizing macrophage membranes via candidalysin and engaging two host cell death pathways, Gasdermin D-mediated pyroptosis and ETosis.
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Affiliation(s)
- Françios A B Olivier
- Infection Program, Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800 VIC, Australia; Centre to Impact AMR, Monash University, Clayton, VIC 3800, Australia
| | | | - Harshini Weerasinghe
- Infection Program, Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800 VIC, Australia; Centre to Impact AMR, Monash University, Clayton, VIC 3800, Australia
| | - Ashley Weir
- The Walter and Eliza Hall Institute of Medical Research, University of Melbourne, Parkville, VIC 3052, Australia; The Department of Medical Biology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Sebastian Hughes
- The Walter and Eliza Hall Institute of Medical Research, University of Melbourne, Parkville, VIC 3052, Australia; The Department of Medical Biology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Simon Crawford
- Monash Ramaciotti Centre for Cryo-Electron Microscopy, Monash University, Clayton, VIC 3800, Australia
| | - James E Vince
- The Walter and Eliza Hall Institute of Medical Research, University of Melbourne, Parkville, VIC 3052, Australia; The Department of Medical Biology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Michael J Hickey
- Monash Centre for Inflammatory Diseases, Monash University Department of Medicine, Monash Medical Centre, Clayton, VIC 3168, Australia
| | - Ana Traven
- Infection Program, Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800 VIC, Australia; Centre to Impact AMR, Monash University, Clayton, VIC 3800, Australia.
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5
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Challagundla N, Saha B, Agrawal-Rajput R. Insights into inflammasome regulation: cellular, molecular, and pathogenic control of inflammasome activation. Immunol Res 2022; 70:578-606. [PMID: 35610534 DOI: 10.1007/s12026-022-09286-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 05/04/2022] [Indexed: 02/07/2023]
Abstract
Maintenance of immune homeostasis is an intricate process wherein inflammasomes play a pivotal role by contributing to innate and adaptive immune responses. Inflammasomes are ensembles of adaptor proteins that can trigger a signal following innate sensing of pathogens or non-pathogens eventuating in the inductions of IL-1β and IL-18. These inflammatory cytokines substantially influence the antigen-presenting cell's costimulatory functions and T helper cell differentiation, contributing to adaptive immunity. As acute and chronic disease conditions may accompany parallel tissue damage, we analyze the critical role of extracellular factors such as cytokines, amyloids, cholesterol crystals, etc., intracellular metabolites, and signaling molecules regulating inflammasome activation/inhibition. We develop an operative framework for inflammasome function and regulation by host cell factors and pathogens. While inflammasomes influence the innate and adaptive immune components' interplay modulating the anti-pathogen adaptive immune response, pathogens may target inflammasome inhibition as a survival strategy. As trapped between health and diseases, inflammasomes serve as promising therapeutic targets and their modus operandi serves as a scientific rationale for devising better therapeutic strategies.
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Affiliation(s)
- Naveen Challagundla
- Immunology lab, Indian Institute of Advanced Research, Gandhinagar, Gujarat, 382007, India
| | - Bhaskar Saha
- National Centre for Cell Science, Lab-5, Ganeshkhind, Pune, Maharashtra, 411007, India
| | - Reena Agrawal-Rajput
- Immunology lab, Indian Institute of Advanced Research, Gandhinagar, Gujarat, 382007, India.
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6
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Simm C, Weerasinghe H, Thomas DR, Harrison PF, Newton HJ, Beilharz TH, Traven A. Disruption of Iron Homeostasis and Mitochondrial Metabolism Are Promising Targets to Inhibit Candida auris. Microbiol Spectr 2022; 10:e0010022. [PMID: 35412372 PMCID: PMC9045333 DOI: 10.1128/spectrum.00100-22] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 03/21/2022] [Indexed: 11/20/2022] Open
Abstract
Fungal infections are a global threat, but treatments are limited due to a paucity in antifungal drug targets and the emergence of drug-resistant fungi such as Candida auris. Metabolic adaptations enable microbial growth in nutrient-scarce host niches, and they further control immune responses to pathogens, thereby offering opportunities for therapeutic targeting. Because it is a relatively new pathogen, little is known about the metabolic requirements for C. auris growth and its adaptations to counter host defenses. Here, we establish that triggering metabolic dysfunction is a promising strategy against C. auris. Treatment with pyrvinium pamoate (PP) induced metabolic reprogramming and mitochondrial dysfunction evident in disrupted mitochondrial morphology and reduced tricarboxylic acid (TCA) cycle enzyme activity. PP also induced changes consistent with disrupted iron homeostasis. Nutrient supplementation experiments support the proposition that PP-induced metabolic dysfunction is driven by disrupted iron homeostasis, which compromises carbon and lipid metabolism and mitochondria. PP inhibited C. auris replication in macrophages, which is a relevant host niche for this yeast pathogen. We propose that PP causes a multipronged metabolic hit to C. auris: it restricts the micronutrient iron to potentiate nutritional immunity imposed by immune cells, and it further causes metabolic dysfunction that compromises the utilization of macronutrients, thereby curbing the metabolic plasticity needed for growth in host environments. Our study offers a new avenue for therapeutic development against drug-resistant C. auris, shows how complex metabolic dysfunction can be caused by a single compound triggering antifungal inhibition, and provides insights into the metabolic needs of C. auris in immune cell environments. IMPORTANCE Over the last decade, Candida auris has emerged as a human pathogen around the world causing life-threatening infections with wide-spread antifungal drug resistance, including pandrug resistance in some cases. In this study, we addressed the mechanism of action of the antiparasitic drug pyrvinium pamoate against C. auris and show how metabolism could be inhibited to curb C. auris proliferation. We show that pyrvinium pamoate triggers sweeping metabolic and mitochondrial changes and disrupts iron homeostasis. PP-induced metabolic dysfunction compromises the utilization of both micro- and macronutrients by C. auris and reduces its growth in vitro and in immune phagocytes. Our findings provide insights into the metabolic requirements for C. auris growth and define the mechanisms of action of pyrvinium pamoate against C. auris, demonstrating how this compound works by inhibiting the metabolic flexibility of the pathogen. As such, our study characterizes credible avenues for new antifungal approaches against C. auris.
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Affiliation(s)
- Claudia Simm
- Infection Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Victoria, Australia
- Centre to Impact AMR, Monash University, Victoria, Australia
| | - Harshini Weerasinghe
- Infection Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Victoria, Australia
- Centre to Impact AMR, Monash University, Victoria, Australia
| | - David R. Thomas
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | | | - Hayley J. Newton
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Traude H. Beilharz
- Development and Stem Cells Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Victoria, Australia
| | - Ana Traven
- Infection Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Victoria, Australia
- Centre to Impact AMR, Monash University, Victoria, Australia
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7
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Liang G, Zhang M, Xu W, Wang X, Zheng H, Mei H, Liu W. Characterization of mitogenomes from four Mucorales species and insights into pathogenicity. Mycoses 2021; 65:45-56. [PMID: 34570921 DOI: 10.1111/myc.13374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 09/14/2021] [Accepted: 09/16/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND Mucorales, as one major order of Zygomycetes fungi, can infect human beings and cause serious consequence. We have noticed the pathogenicity of Mucorales is closely related to energy metabolism, while mitochondria play the role of energy factories in almost all biological activities. METHODS Virulence of M irregularis, M hiemalis, L corymbifera and R arrhizus were verified in Galleria mellonella larvae, as well as mitochondrial gene copies analysed with RT-qPCR. Mitogenomes of the four Mucorales species were sequenced based on illumina NovaSeq technology to study their characteristic features and functional regions. RESULTS Variant virulence of M irregularis, M hiemalis, L corymbifera and R arrhizu were verified by clinical retrospective data and our G mellonella infection models, also copies of mitochondrial genes indicated the significant associations with pathogenicity. A total of 274.18 clean reads were generated to be assembled; the complete mitogenomes of the four Mucorales species were obtained with totally different length. After the genomes annotated and compared, M irregularis was found more similar with M hiemalis than those of L corymbifera and R arrhizus, especially the small (rrns) and large (rrnl) subunits of mitochondrial ribosomal RNA (rRNA) genes. The GC content, ncRNAs and the distribution of the SNPs and InDels were also compared, and the GC content rate of fungi seems to be related to the fungal thermal adaptability. In addition, linear mitogenomes of these four Mucorales showed diverse arrangements of orf genes and directionality of some conserved gene elements. CONCLUSION This study uncovered the pathogenicity variances among the four Mucorales species and the relationship between their mitogenomic features and clinical pathogenicity. Further studies like spatial structure of mitochondrial genomes and the comprehensive analysis of transcription regulation are needed.
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Affiliation(s)
- Guanzhao Liang
- Department of Medical Mycology, Institute of Dermatology, Chinese Academy of Medical Science and Peking Union Medical College, Nanjing, China.,CAMS Collection Center of Pathogen Microorganisms-D (CAMS-CCPM-D), Nanjing, China.,Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, China
| | - Meijie Zhang
- Department of Medical Mycology, Institute of Dermatology, Chinese Academy of Medical Science and Peking Union Medical College, Nanjing, China.,CAMS Collection Center of Pathogen Microorganisms-D (CAMS-CCPM-D), Nanjing, China.,Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, China
| | - Wenqi Xu
- Department of Medical Mycology, Institute of Dermatology, Chinese Academy of Medical Science and Peking Union Medical College, Nanjing, China.,CAMS Collection Center of Pathogen Microorganisms-D (CAMS-CCPM-D), Nanjing, China.,Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, China
| | - Xiaowen Wang
- Shanghai BIOZERON Biotechnology Co., Ltd., Shanghai, China
| | - Hailin Zheng
- Department of Medical Mycology, Institute of Dermatology, Chinese Academy of Medical Science and Peking Union Medical College, Nanjing, China.,CAMS Collection Center of Pathogen Microorganisms-D (CAMS-CCPM-D), Nanjing, China.,Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, China
| | - Huan Mei
- Department of Medical Mycology, Institute of Dermatology, Chinese Academy of Medical Science and Peking Union Medical College, Nanjing, China.,CAMS Collection Center of Pathogen Microorganisms-D (CAMS-CCPM-D), Nanjing, China.,Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, China
| | - Weida Liu
- Department of Medical Mycology, Institute of Dermatology, Chinese Academy of Medical Science and Peking Union Medical College, Nanjing, China.,CAMS Collection Center of Pathogen Microorganisms-D (CAMS-CCPM-D), Nanjing, China.,Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, China.,Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
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8
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Black B, Lee C, Horianopoulos LC, Jung WH, Kronstad JW. Respiring to infect: Emerging links between mitochondria, the electron transport chain, and fungal pathogenesis. PLoS Pathog 2021; 17:e1009661. [PMID: 34237096 PMCID: PMC8266039 DOI: 10.1371/journal.ppat.1009661] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- Braydon Black
- Michael Smith Laboratories, Department of Microbiology & Immunology, University of British Columbia, Vancouver, Canada
| | - Christopher Lee
- Michael Smith Laboratories, Department of Microbiology & Immunology, University of British Columbia, Vancouver, Canada
| | - Linda C. Horianopoulos
- Michael Smith Laboratories, Department of Microbiology & Immunology, University of British Columbia, Vancouver, Canada
| | - Won Hee Jung
- Department of Systems Biotechnology, Chung-Ang University, Anseong, Republic of Korea
| | - James W. Kronstad
- Michael Smith Laboratories, Department of Microbiology & Immunology, University of British Columbia, Vancouver, Canada
- * E-mail:
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9
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Corcoran SE, Halai R, Cooper MA. Pharmacological Inhibition of the Nod-Like Receptor Family Pyrin Domain Containing 3 Inflammasome with MCC950. Pharmacol Rev 2021; 73:968-1000. [PMID: 34117094 DOI: 10.1124/pharmrev.120.000171] [Citation(s) in RCA: 91] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Activation of the Nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome drives release of the proinflammatory cytokines interleukin (IL)-1β and IL-18 and induces pyroptosis (lytic cell death). These events drive chronic inflammation, and as such, NLRP3 has been implicated in a large number of human diseases. These range from autoimmune conditions, the simplest of which is NLRP3 gain-of-function mutations leading to an orphan disease, cryopyrin-associated period syndrome, to large disease burden indications, such as atherosclerosis, heart failure, stroke, neurodegeneration, asthma, ulcerative colitis, and arthritis. The potential clinical utility of NLRP3 inhibitors is substantiated by an expanding list of indications in which NLRP3 activation has been shown to play a detrimental role. Studies of pharmacological inhibition of NLRP3 in nonclinical models of disease using MCC950 in combination with human genetics, epigenetics, and analyses of the efficacy of biologic inhibitors of IL-1β, such as anakinra and canakinumab, can help to prioritize clinical trials of NLRP3-directed therapeutics. Although MCC950 shows excellent (nanomolar) potency and high target selectivity, its pharmacokinetic and toxicokinetic properties limited its therapeutic development in the clinic. Several improved, next-generation inhibitors are now in clinical trials. Hence the body of research in a plethora of conditions reviewed herein may inform analysis of the potential translational value of NLRP3 inhibition in diseases with significant unmet medical need. SIGNIFICANCE STATEMENT: The nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is one of the most widely studied and best validated biological targets in innate immunity. Activation of NLRP3 can be inhibited with MCC950, resulting in efficacy in more than 100 nonclinical models of inflammatory diseases. As several next-generation NLRP3 inhibitors are entering proof-of-concept clinical trials in 2020, a review of the pharmacology of MCC950 is timely and significant.
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Affiliation(s)
- Sarah E Corcoran
- Trinity College Dublin, Dublin, Ireland (S.E.C.); Inflazome, D6 Grain House, Mill Court, Great Shelford, Cambridge, United Kingdom (R.H., M.A.C.); and Institute for Molecular Bioscience, University of Queensland, Queensland, Australia (M.A.C.)
| | - Reena Halai
- Trinity College Dublin, Dublin, Ireland (S.E.C.); Inflazome, D6 Grain House, Mill Court, Great Shelford, Cambridge, United Kingdom (R.H., M.A.C.); and Institute for Molecular Bioscience, University of Queensland, Queensland, Australia (M.A.C.)
| | - Matthew A Cooper
- Trinity College Dublin, Dublin, Ireland (S.E.C.); Inflazome, D6 Grain House, Mill Court, Great Shelford, Cambridge, United Kingdom (R.H., M.A.C.); and Institute for Molecular Bioscience, University of Queensland, Queensland, Australia (M.A.C.)
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10
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Santos HJ, Nozaki T. Interorganellar communication and membrane contact sites in protozoan parasites. Parasitol Int 2021; 83:102372. [PMID: 33933652 DOI: 10.1016/j.parint.2021.102372] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 04/21/2021] [Accepted: 04/27/2021] [Indexed: 12/29/2022]
Abstract
A key characteristic of eukaryotic cells is the presence of organelles with discrete boundaries and functions. Such subcellular compartmentalization into organelles necessitates platforms for communication and material exchange between each other which often involves vesicular trafficking and associated processes. Another way is via the close apposition between organellar membranes, called membrane contact sites (MCSs). Apart from lipid transfer, MCSs have been implicated to mediate in various cellular processes including ion transport, apoptosis, and organelle dynamics. In mammalian and yeast cells, contact sites have been reported between the membranes of the following: the endoplasmic reticulum (ER) and the plasma membrane (PM), ER and the Golgi apparatus, ER and endosomes (i.e., vacuoles, lysosomes), ER and lipid droplets (LD), the mitochondria and vacuoles, the nucleus and vacuoles, and the mitochondria and lipid droplets, whereas knowledge of MCSs in non-model organisms such as protozoan parasites is extremely limited. Growing evidence suggests that MCSs play more general and conserved roles in cell physiology. In this mini review, we summarize and discuss representative MCSs in divergent parasitic protozoa, and highlight the universality, diversity, and the contribution of MCSs to parasitism.
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Affiliation(s)
- Herbert J Santos
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
| | - Tomoyoshi Nozaki
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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11
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Hodgins-Davis A, O'Meara TR. Systems biology of host-Candida interactions: understanding how we shape each other. Curr Opin Microbiol 2020; 58:1-7. [PMID: 32485592 PMCID: PMC7704567 DOI: 10.1016/j.mib.2020.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/21/2020] [Accepted: 04/23/2020] [Indexed: 11/24/2022]
Abstract
Candida albicans is both a member of the human mucosal microbiota and a common agent of invasive fungal disease. Systems biology approaches allow for analysis of the interactions between this fungus and its mammalian host. Framing these studies by considering how C. albicans and its host construct the niche the other occupies provides insight into how these interactions shape the ecosystems, behavior, and evolution of each organism. Here, we discuss recent work on multiscale systems biology approaches for examining C. albicans in relation to the host ecosystem to identify the emergent properties of the interactions and new variables that can be targeted for development of therapeutic strategies.
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Affiliation(s)
- Andrea Hodgins-Davis
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Teresa R O'Meara
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.
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12
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The RSC (Remodels the Structure of Chromatin) complex of Candida albicans shows compositional divergence with distinct roles in regulating pathogenic traits. PLoS Genet 2020; 16:e1009071. [PMID: 33151931 PMCID: PMC7671503 DOI: 10.1371/journal.pgen.1009071] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 11/17/2020] [Accepted: 08/24/2020] [Indexed: 01/08/2023] Open
Abstract
Regulation of gene expression programs is crucial for the survival of microbial pathogens in host environments and for their ability to cause disease. Here we investigated the epigenetic regulator RSC (Remodels the Structure of Chromatin) in the most prevalent human fungal pathogen Candida albicans. Biochemical analysis showed that CaRSC comprises 13 subunits and contains two novel non-essential members, which we named Nri1 and Nri2 (Novel RSC Interactors) that are exclusive to the CTG clade of Saccharomycotina. Genetic analysis showed distinct essentiality of C. albicans RSC subunits compared to model fungal species suggesting functional and structural divergence of RSC functions in this fungal pathogen. Transcriptomic and proteomic profiling of a conditional mutant of the essential catalytic subunit gene STH1 demonstrated global roles of RSC in C. albicans biology, with the majority of growth-related processes affected, as well as mis-regulation of genes involved in morphotype switching, host-pathogen interaction and adaptive fitness. We further assessed the functions of non-essential CaRSC subunits, showing that the novel subunit Nri1 and the bromodomain subunit Rsc4 play roles in filamentation and stress responses; and also interacted at the genetic level to regulate cell viability. Consistent with these roles, Rsc4 is required for full virulence of C. albicans in the murine model of systemic infection. Taken together, our data builds the first comprehensive study of the composition and roles of RSC in C. albicans, showing both conserved and distinct features compared to model fungal systems. The study illuminates how C. albicans uses RSC-dependent transcriptional regulation to respond to environmental signals and drive survival fitness and virulence in mammals.
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W Figueira L, de Oliveira JR, Netto AA, S Zamarioli LD, Marcucci MC, Camargo SE, de Oliveira LD. Curcuma longa L. helps macrophages to control opportunistic micro-organisms during host-microbe interactions. Future Microbiol 2020; 15:1237-1248. [PMID: 33026878 DOI: 10.2217/fmb-2019-0297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: Plant products have been evaluated to control opportunistic micro-organisms, as well as fortify immune system cells. Thus, Curcuma longa L. (turmeric) extract was evaluated in interactions of murine macrophages (RAW 264.7) with Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans, in order to establish cooperation with defense cells. Materials & methods: Effects of minimal inhibitory concentrations (MIC) of the plant extract were analyzed on phagocytosis, cell viability of RAW 264.7 and production of inflammation-related molecules (IL-1β, TNF-α, IL-10 and NO). Results: The plant extract was cytocompatible and promoted significant reductions of micro-organisms, and synthesis of inflammation-related molecules, during interactions. Conclusion: C. longa L. extract showed significant antimicrobial response and cooperation with macrophages, by fighting bacteria and yeasts during host-microbe interactions.
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Affiliation(s)
- Leandro W Figueira
- Department of Biosciences & Oral Diagnosis, São Paulo State University (UNESP), Institute of Science & Technology, Av. Engenheiro Francisco José Longo, 777, São José dos Campos, SP 2245-000, Brazil
| | - Jonatas R de Oliveira
- Department of Biosciences & Oral Diagnosis, São Paulo State University (UNESP), Institute of Science & Technology, Av. Engenheiro Francisco José Longo, 777, São José dos Campos, SP 2245-000, Brazil.,School of Medicine, Anhembi Morumbi University, Av. Dep. Benedito Matarazzo, 4050, São José dos Campos, SP 12230-002, Brazil
| | - Amandio Al Netto
- Anhanguera University, Av. Raimundo Pereira de Magalhães, 3305. São Paulo, SP 05145-200, Brazil
| | - Lucas Dos S Zamarioli
- Department of Mode of Drug Action, Federal University of São Paulo (UNIFESP), Institute of Pharmacology & Molecular Biology, Rua Três de Maio, 100 São Paulo, SP 04044-020, Brazil
| | - Maria C Marcucci
- Anhanguera University, Av. Raimundo Pereira de Magalhães, 3305. São Paulo, SP 05145-200, Brazil
| | - Samira Ea Camargo
- Department of Restorative Dental Sciences, College of Dentistry, University of Florida, 1395 Center Drive, Gainesville, FL 32610, USA
| | - Luciane D de Oliveira
- Department of Biosciences & Oral Diagnosis, São Paulo State University (UNESP), Institute of Science & Technology, Av. Engenheiro Francisco José Longo, 777, São José dos Campos, SP 2245-000, Brazil
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14
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Protection of MCC950 against Alzheimer's disease via inhibiting neuronal pyroptosis in SAMP8 mice. Exp Brain Res 2020; 238:2603-2614. [DOI: 10.1007/s00221-020-05916-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 08/31/2020] [Indexed: 12/13/2022]
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15
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Tucey TM, Verma J, Olivier FAB, Lo TL, Robertson AAB, Naderer T, Traven A. Metabolic competition between host and pathogen dictates inflammasome responses to fungal infection. PLoS Pathog 2020; 16:e1008695. [PMID: 32750090 PMCID: PMC7433900 DOI: 10.1371/journal.ppat.1008695] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 08/18/2020] [Accepted: 06/07/2020] [Indexed: 12/11/2022] Open
Abstract
The NLRP3 inflammasome has emerged as a central immune regulator that senses virulence factors expressed by microbial pathogens for triggering inflammation. Inflammation can be harmful and therefore this response must be tightly controlled. The mechanisms by which immune cells, such as macrophages, discriminate benign from pathogenic microbes to control the NLRP3 inflammasome remain poorly defined. Here we used live cell imaging coupled with a compendium of diverse clinical isolates to define how macrophages respond and activate NLRP3 when faced with the human yeast commensal and pathogen Candida albicans. We show that metabolic competition by C. albicans, rather than virulence traits such as hyphal formation, activates NLRP3 in macrophages. Inflammasome activation is triggered by glucose starvation in macrophages, which occurs when fungal load increases sufficiently to outcompete macrophages for glucose. Consistently, reducing Candida’s ability to compete for glucose and increasing glucose availability for macrophages tames inflammatory responses. We define the mechanistic requirements for glucose starvation-dependent inflammasome activation by Candida and show that it leads to inflammatory cytokine production, but it does not trigger pyroptotic macrophage death. Pyroptosis occurs only with some Candida isolates and only under specific experimental conditions, whereas inflammasome activation by glucose starvation is broadly relevant. In conclusion, macrophages use their metabolic status, specifically glucose metabolism, to sense fungal metabolic activity and activate NLRP3 when microbial load increases. Therefore, a major consequence of Candida-induced glucose starvation in macrophages is activation of inflammatory responses, with implications for understanding how metabolism modulates inflammation in fungal infections. Activation of the immune regulator NLRP3 inflammasome by microbial pathogens has been shown to play both protective and destructive roles in infection, underscoring the importance of tight control over NLRP3-driven inflammation to ensure host health. A key microbe recognised by NLRP3 is the human yeast commensal and pathogen Candida albicans, which is responsible for mucosal and invasive infections. We demonstrate that innate immune cells sense their metabolic status to trigger NLRP3 activation only when microbial numbers have reached dangerous levels. This regulation is a consequence of metabolic competition between C. albicans and macrophages for an essential nutrient–glucose. The NLRP3 inflammasome is activated when increased fungal load in the infection microenvironment drives down glucose levels, thereby causing glucose starvation in macrophages. Restoring glucose homeostasis in macrophages reduced NLRP3 activation and production of the proinflammatory cytokine IL-1β, suggesting that metabolism regulates NLRP3 inflammasome activity in fungal infections.
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Affiliation(s)
- Timothy M. Tucey
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Jiyoti Verma
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Françios A. B. Olivier
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Tricia L. Lo
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Avril A. B. Robertson
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Australia
| | - Thomas Naderer
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Ana Traven
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- * E-mail:
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König A, Hube B, Kasper L. The Dual Function of the Fungal Toxin Candidalysin during Candida albicans-Macrophage Interaction and Virulence. Toxins (Basel) 2020; 12:toxins12080469. [PMID: 32722029 PMCID: PMC7471981 DOI: 10.3390/toxins12080469] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/16/2020] [Accepted: 07/19/2020] [Indexed: 12/12/2022] Open
Abstract
The dimorphic fungus Candida albicans is both a harmless commensal organism on mucosal surfaces and an opportunistic pathogen. Under certain predisposing conditions, the fungus can overgrow the mucosal microbiome and cause both superficial and life-threatening systemic infections after gaining access to the bloodstream. As the first line of defense of the innate immune response, infecting C. albicans cells face macrophages, which mediate the clearance of invading fungi by intracellular killing. However, the fungus has evolved sophisticated strategies to counteract macrophage antimicrobial activities and thus evade immune surveillance. The cytolytic peptide toxin, candidalysin, contributes to this fungal defense machinery by damaging immune cell membranes, providing an escape route from the hostile phagosome environment. Nevertheless, candidalysin also induces NLRP3 inflammasome activation, leading to an increased host-protective pro-inflammatory response in mononuclear phagocytes. Therefore, candidalysin facilitates immune evasion by acting as a classical virulence factor but also contributes to an antifungal immune response, serving as an avirulence factor. In this review, we discuss the role of candidalysin during C. albicans infections, focusing on its implications during C. albicans-macrophage interactions.
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Affiliation(s)
- Annika König
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology–Hans Knoell Institute, 07745 Jena, Germany;
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology–Hans Knoell Institute, 07745 Jena, Germany;
- Center for Sepsis Control and Care, University Hospital Jena, 07747 Jena, Germany
- Institute of Microbiology, Friedrich Schiller University, 07743 Jena, Germany
- Correspondence: (B.H.); (L.K.)
| | - Lydia Kasper
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology–Hans Knoell Institute, 07745 Jena, Germany;
- Correspondence: (B.H.); (L.K.)
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17
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Wang Q, Verma J, Vidan N, Wang Y, Tucey TM, Lo TL, Harrison PF, See M, Swaminathan A, Kuchler K, Tscherner M, Song J, Powell DR, Sopta M, Beilharz TH, Traven A. The YEATS Domain Histone Crotonylation Readers Control Virulence-Related Biology of a Major Human Pathogen. Cell Rep 2020; 31:107528. [PMID: 32320659 DOI: 10.1016/j.celrep.2020.107528] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 01/31/2020] [Accepted: 03/27/2020] [Indexed: 12/13/2022] Open
Abstract
Identification of multiple histone acylations diversifies transcriptional control by metabolism, but their functions are incompletely defined. Here we report evidence of histone crotonylation in the human fungal pathogen Candida albicans. We define the enzymes that regulate crotonylation and show its dynamic control by environmental signals: carbon sources, the short-chain fatty acids butyrate and crotonate, and cell wall stress. Crotonate regulates stress-responsive transcription and rescues C. albicans from cell wall stress, indicating broad impact on cell biology. The YEATS domain crotonylation readers Taf14 and Yaf9 are required for C. albicans virulence, and Taf14 controls gene expression, stress resistance, and invasive growth via its chromatin reader function. Blocking the Taf14 C terminus with a tag reduced virulence, suggesting that inhibiting Taf14 interactions with chromatin regulators impairs function. Our findings shed light on the regulation of histone crotonylation and the functions of the YEATS proteins in eukaryotic pathogen biology and fungal infections.
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Affiliation(s)
- Qi Wang
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800 VIC, Australia
| | - Jiyoti Verma
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800 VIC, Australia
| | - Nikolina Vidan
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800 VIC, Australia; Department of Molecular Biology, Rudjer Boskovic Institute, Bijenicka 54, 10000 Zagreb, Croatia
| | - Yanan Wang
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800 VIC, Australia
| | - Timothy M Tucey
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800 VIC, Australia
| | - Tricia L Lo
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800 VIC, Australia
| | - Paul F Harrison
- Bioinformatics Platform, Monash University, Clayton 3800 VIC, Australia
| | - Michael See
- Bioinformatics Platform, Monash University, Clayton 3800 VIC, Australia
| | - Angavai Swaminathan
- Development and Stem Cells Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800 VIC, Australia
| | - Karl Kuchler
- Medical University of Vienna, Center for Medical Biochemistry, Max Perutz Labs, Campus Vienna Biocenter, Dr. Bohr-Gasse 9/2, Vienna, Austria
| | - Michael Tscherner
- Medical University of Vienna, Center for Medical Biochemistry, Max Perutz Labs, Campus Vienna Biocenter, Dr. Bohr-Gasse 9/2, Vienna, Austria
| | - Jiangning Song
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800 VIC, Australia
| | - David R Powell
- Bioinformatics Platform, Monash University, Clayton 3800 VIC, Australia
| | - Mary Sopta
- Department of Molecular Biology, Rudjer Boskovic Institute, Bijenicka 54, 10000 Zagreb, Croatia
| | - Traude H Beilharz
- Development and Stem Cells Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800 VIC, Australia
| | - Ana Traven
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800 VIC, Australia.
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18
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Kundu D, Pasrija R. The ERMES (Endoplasmic Reticulum and Mitochondria Encounter Structures) mediated functions in fungi. Mitochondrion 2020; 52:89-99. [PMID: 32105794 DOI: 10.1016/j.mito.2020.02.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Revised: 12/21/2019] [Accepted: 02/21/2020] [Indexed: 01/01/2023]
Abstract
Cellular organelles are membrane-bound and provide a microenvironment for specific functions. A mitochondrion is a double membranous and dynamic organelle that undergoes numerous fusion/fission events, which depends on various cellular factors. However, it is still dependent on other organelles and requires both communications as well as the movement of physical metabolites between them. Mitochondria interact with different organelles counting lipid droplets (LD), peroxisomes, vacuoles, endoplasmic reticulum (ER) and plasma membrane (PM), etc. Apart from them, mitochondria maintain multiple interactions with ER including ERMES (Endoplasmic Reticulum and Mitochondria encounter structures). ERMES is actually a multi-protein complex, and imperative in the maintenance of mitochondrial morphology and its functions. Its disruption also compromises phospholipid exchange, drug resistance and pathogenicity. This assembly is reportedly unique to fungal systems and proposed as a target for development of new antifungal. In the light of separate reports across diverse fungal systems, we have summarised the information about its distribution and effect on mitochondrial fitness.
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Affiliation(s)
- Deepika Kundu
- Department of Biochemistry, Maharshi Dayanand University, Rohtak, Haryana, India
| | - Ritu Pasrija
- Department of Biochemistry, Maharshi Dayanand University, Rohtak, Haryana, India.
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Koch B, Barugahare AA, Lo TL, Huang C, Schittenhelm RB, Powell DR, Beilharz TH, Traven A. A Metabolic Checkpoint for the Yeast-to-Hyphae Developmental Switch Regulated by Endogenous Nitric Oxide Signaling. Cell Rep 2019; 25:2244-2258.e7. [PMID: 30463019 DOI: 10.1016/j.celrep.2018.10.080] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 07/31/2018] [Accepted: 10/22/2018] [Indexed: 12/13/2022] Open
Abstract
The yeast Candida albicans colonizes several sites in the human body and responds to metabolic signals in commensal and pathogenic states. The yeast-to-hyphae transition correlates with virulence, but how metabolic status is integrated with this transition is incompletely understood. We used the putative mitochondrial fission inhibitor mdivi-1 to probe the crosstalk between hyphal signaling and metabolism. Mdivi-1 repressed C. albicans hyphal morphogenesis, but the mechanism was independent of its presumed target, the mitochondrial fission GTPase Dnm1. Instead, mdivi-1 triggered extensive metabolic reprogramming, consistent with metabolic stress, and reduced endogenous nitric oxide (NO) levels. Limiting endogenous NO stabilized the transcriptional repressor Nrg1 and inhibited the yeast-to-hyphae transition. We establish a role for endogenous NO signaling in C. albicans hyphal morphogenesis and suggest that NO regulates a metabolic checkpoint for hyphal growth. Furthermore, identifying NO signaling as an mdivi-1 target could inform its therapeutic applications in human diseases.
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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 3800, Australia
| | - Adele A Barugahare
- Bioinformatics Platform, Monash University, Clayton, VIC 3800, Australia
| | - Tricia L Lo
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - Cheng Huang
- Biomedical Proteomics Facility and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - Ralf B Schittenhelm
- Biomedical Proteomics Facility and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - David R Powell
- Bioinformatics Platform, Monash University, Clayton, VIC 3800, Australia
| | - Traude H Beilharz
- Development and Stem Cells Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - Ana Traven
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia.
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20
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Cairns TC, Feurstein C, Zheng X, Zhang LH, Zheng P, Sun J, Meyer V. Functional exploration of co-expression networks identifies a nexus for modulating protein and citric acid titres in Aspergillus niger submerged culture. Fungal Biol Biotechnol 2019; 6:18. [PMID: 31728200 PMCID: PMC6842248 DOI: 10.1186/s40694-019-0081-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 10/21/2019] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Filamentous fungal cell factories are used to produce numerous proteins, enzymes, and organic acids. Protein secretion and filamentous growth are tightly coupled at the hyphal tip. Additionally, both these processes require ATP and amino acid precursors derived from the citric acid cycle. Despite this interconnection of organic acid production and protein secretion/filamentous growth, few studies in fungi have identified genes which may concomitantly impact all three processes. RESULTS We applied a novel screen of a global co-expression network in the cell factory Aspergillus niger to identify candidate genes which may concomitantly impact macromorphology, and protein/organic acid fermentation. This identified genes predicted to encode the Golgi localized ArfA GTPase activating protein (GAP, AgeB), and ArfA guanine nucleotide exchange factors (GEFs SecG and GeaB) to be co-expressed with citric acid cycle genes. Consequently, we used CRISPR-based genome editing to place the titratable Tet-on expression system upstream of ageB, secG, and geaB in A. niger. Functional analysis revealed that ageB and geaB are essential whereas secG was dispensable for early filamentous growth. Next, gene expression was titrated during submerged cultivations under conditions for either protein or organic acid production. ArfA regulators played varied and culture-dependent roles on pellet formation. Notably, ageB or geaB expression levels had major impacts on protein secretion, whereas secG was dispensable. In contrast, reduced expression of each predicted ArfA regulator resulted in an absence of citric acid in growth media. Finally, titrated expression of either GEFs resulted in an increase in oxaloacetic acid concentrations in supernatants. CONCLUSION Our data suggest that the Golgi may play an underappreciated role in modulating organic acid titres during industrial applications, and that this is SecG, GeaB and AgeB dependent in A. niger. These data may lead to novel avenues for strain optimization in filamentous fungi for improved protein and organic acid titres.
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Affiliation(s)
- Timothy C. Cairns
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
| | - Claudia Feurstein
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
- Institute of Biotechnology, Chair of Applied and Molecular Microbiology, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Xiaomei Zheng
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Li Hui Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457 China
| | - Ping Zheng
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Jibin Sun
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Vera Meyer
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
- Institute of Biotechnology, Chair of Applied and Molecular Microbiology, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
- University of Chinese Academy of Sciences, Beijing, 100049 China
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Abstract
Candida albicans is an opportunistic fungal pathogen of major clinical concern. The virulence of this pathogen is intimately intertwined with its metabolism. Mitochondria, which have a central metabolic role, have undergone many lineage-specific adaptations in association with their eukaryotic host. A screen for lineage-specific genes identified seven such genes specific to the CTG clade of fungi, of which C. albicans is a member. Each is required for respiratory growth and is integral to expression of complex I, III, or IV of the electron transport chain. Two genes, NUO3 and NUO4, encode supernumerary subunits of complex I, whereas NUE1 and NUE2 have nonstructural roles in expression of complex I. Similarly, the other three genes have nonstructural roles in expression of complex III (QCE1) or complex IV (COE1 and COE2). In addition to these novel additions, an alternative functional assignment was found for the mitochondrial protein encoded by MNE1 MNE1 was required for complex I expression in C. albicans, whereas the distantly related Saccharomyces cerevisiae ortholog participates in expression of complex III. Phenotypic analysis of deletion mutants showed that fermentative metabolism is unable to support optimal growth rates or yields of C. albicans However, yeast-hypha morphogenesis, an important virulence attribute, did not require respiratory metabolism under hypoxic conditions. The inability to respire also resulted in hypersensitivity to the antifungal fluconazole and in attenuated virulence in a Galleria mellonella infection model. The results show that lineage-specific adaptations have occurred in C. albicans mitochondria and highlight the significance of respiratory metabolism in the pathobiology of C. albicans IMPORTANCE Candida albicans is an opportunistic fungal pathogen of major clinical concern. The virulence of this pathogen is intimately intertwined with its metabolic behavior, and mitochondria have a central role in that metabolism. Mitochondria have undergone many evolutionary changes, which include lineage-specific adaptations in association with their eukaryotic host. Seven lineage-specific genes required for electron transport chain function were identified in the CTG clade of fungi, of which C. albicans is a member. Additionally, examination of several highly diverged orthologs encoding mitochondrial proteins demonstrated functional reassignment for one of these. Deficits imparted by deletion of these genes revealed the critical role of respiration in virulence attributes of the fungus and highlight important evolutionary adaptations in C. albicans metabolism.
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Koch B, Traven A. Mitochondrial Control of Fungal Cell Walls: Models and Relevance in Fungal Pathogens. Curr Top Microbiol Immunol 2019; 425:277-296. [PMID: 31807895 DOI: 10.1007/82_2019_183] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Proper structure and function of the fungal cell wall are controlled by metabolic processes, as well as an interplay between a range of cellular organelles. Somewhat surprisingly, mitochondrial function has been shown to be important for proper cell wall biogenesis and integrity. Mitochondria also play a role in the susceptibility of fungi to cell wall-targeting drugs. This is true in a range of fungal species, including important human fungal pathogens. The biochemical mechanisms that explain the roles of mitochondria in cell wall biology have remained elusive, but studies to date strongly support the idea that mitochondrial control over cellular lipid homeostasis is at the core of these processes. Excitingly, recent evidence suggests that the mitochondria-lipid linkages drive resistance to the echinocandin drug caspofungin, a clinically important therapeutic that targets cell wall biosynthesis. Here, we review the state of affairs in mitochondria-fungal cell wall research and propose models that could be tested in future studies. Elucidating the mechanisms that drive fungal cell wall integrity through mitochondrial functions holds promise for developing new strategies to combat fungal infections, including the possibility to potentiate the effects of antifungal drugs and curb drug resistance.
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Affiliation(s)
- Barbara Koch
- Infection and Immunity Program, Department of Biochemistry and Molecular Biology, Monash University, Clayton, 3800, VIC, Australia.,Protein, Science and Engineering, Callaghan Innovation, Christchurch, 8140, New Zealand
| | - Ana Traven
- Infection and Immunity Program, Department of Biochemistry and Molecular Biology, Monash University, Clayton, 3800, VIC, Australia.
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23
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Kasper L, König A, Koenig PA, Gresnigt MS, Westman J, Drummond RA, Lionakis MS, Groß O, Ruland J, Naglik JR, Hube B. The fungal peptide toxin Candidalysin activates the NLRP3 inflammasome and causes cytolysis in mononuclear phagocytes. Nat Commun 2018; 9:4260. [PMID: 30323213 PMCID: PMC6189146 DOI: 10.1038/s41467-018-06607-1] [Citation(s) in RCA: 167] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 09/13/2018] [Indexed: 01/03/2023] Open
Abstract
Clearance of invading microbes requires phagocytes of the innate immune system. However, successful pathogens have evolved sophisticated strategies to evade immune killing. The opportunistic human fungal pathogen Candida albicans is efficiently phagocytosed by macrophages, but causes inflammasome activation, host cytolysis, and escapes after hypha formation. Previous studies suggest that macrophage lysis by C. albicans results from early inflammasome-dependent cell death (pyroptosis), late damage due to glucose depletion and membrane piercing by growing hyphae. Here we show that Candidalysin, a cytolytic peptide toxin encoded by the hypha-associated gene ECE1, is both a central trigger for NLRP3 inflammasome-dependent caspase-1 activation via potassium efflux and a key driver of inflammasome-independent cytolysis of macrophages and dendritic cells upon infection with C. albicans. This suggests that Candidalysin-induced cell damage is a third mechanism of C. albicans-mediated mononuclear phagocyte cell death in addition to damage caused by pyroptosis and the growth of glucose-consuming hyphae.
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Affiliation(s)
- Lydia Kasper
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knoell Institute, Beutenbergstrasse 11a, Jena, 07745, Germany
| | - Annika König
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knoell Institute, Beutenbergstrasse 11a, Jena, 07745, Germany
| | - Paul-Albert Koenig
- Institute of Clinical Chemistry and Pathobiochemistry, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Ismaninger Str. 22, München, 81675, Germany
| | - Mark S Gresnigt
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knoell Institute, Beutenbergstrasse 11a, Jena, 07745, Germany
| | - Johannes Westman
- Program in Cell Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1×8, Canada
| | - Rebecca A Drummond
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fungal Pathogenesis Section, Laboratory of Clinical Immunology & Microbiology, 9000 Rockville Pike, Bldg 10 / Rm 11C102, Bethesda, MD, 20892, USA.,Institute of Immunology and Immunotherapy, Institute of Microbiology and Infection, University of Birmingham, Birmingham, B15 2TT, UK
| | - Michail S Lionakis
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fungal Pathogenesis Section, Laboratory of Clinical Immunology & Microbiology, 9000 Rockville Pike, Bldg 10 / Rm 11C102, Bethesda, MD, 20892, USA
| | - Olaf Groß
- Institute of Neuropathology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Breisacher Straße 64, Freiburg, 79106, Germany
| | - Jürgen Ruland
- Institute of Clinical Chemistry and Pathobiochemistry, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Ismaninger Str. 22, München, 81675, Germany.,TranslaTUM, Center for Translational Cancer Research, Technische Universität München, München, 81675, Germany.,German Cancer Consortium (DKTK), Heidelberg, 69120, Germany.,German Center for Infection Research (DZIF), Munich, 81675, Germany
| | - Julian R Naglik
- Mucosal and Salivary Biology Division, King's College London Dental Institute, London, SE1 1UL, UK
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knoell Institute, Beutenbergstrasse 11a, Jena, 07745, Germany. .,Friedrich Schiller University, Fürstengraben 1, Jena, 07743, Germany.
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24
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High-Throughput Screening Identifies Genes Required for Candida albicans Induction of Macrophage Pyroptosis. mBio 2018; 9:mBio.01581-18. [PMID: 30131363 PMCID: PMC6106084 DOI: 10.1128/mbio.01581-18] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The innate immune system is the first line of defense against invasive fungal infections. As a consequence, many successful fungal pathogens have evolved elegant strategies to interact with host immune cells. For example, Candida albicans undergoes a morphogenetic switch coupled to cell wall remodeling upon phagocytosis by macrophages and then induces macrophage pyroptosis, an inflammatory cell death program. To elucidate the genetic circuitry through which C. albicans orchestrates this host response, we performed the first large-scale analysis of C. albicans interactions with mammalian immune cells. We identified 98 C. albicans genes that enable macrophage pyroptosis without influencing fungal cell morphology in the macrophage, including specific determinants of cell wall biogenesis and the Hog1 signaling cascade. Using these mutated genes, we discovered that defects in the activation of pyroptosis affect immune cell recruitment during infection. Examining host circuitry required for pyroptosis in response to C. albicans infection, we discovered that inflammasome priming and activation can be decoupled. Finally, we observed that apoptosis-associated speck-like protein containing a CARD (ASC) oligomerization can occur prior to phagolysosomal rupture by C. albicans hyphae, demonstrating that phagolysosomal rupture is not the inflammasome activating signal. Taking the data together, this work defines genes that enable fungal cell wall remodeling and activation of macrophage pyroptosis independently of effects on morphogenesis and identifies macrophage signaling components that are required for pyroptosis in response to C. albicans infection. Candida albicans is a natural member of the human mucosal microbiota that can also cause superficial infections and life-threatening systemic infections, both of which are characterized by inflammation. Host defense relies mainly on the ingestion and destruction of C. albicans by innate immune cells, such as macrophages and neutrophils. Although some C. albicans cells are killed by macrophages, most undergo a morphological change and escape by inducing macrophage pyroptosis. Here, we investigated the C. albicans genes and host factors that promote macrophage pyroptosis in response to intracellular fungi. This work provides a foundation for understanding how host immune cells interact with C. albicans and may lead to effective strategies to modulate inflammation induced by fungal infections.
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25
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Abstract
Various fungi and bacteria can colonize in the brain and produce physical alterations seen in Alzheimer’s disease (AD). Environmental and genetic factors affect the occurrence of fungal colonization, and how fungi can grow, enter the brain, and interact with the innate immune system. The essence of AD development is the defeat of the innate immune system, whether through vulnerable patient health status or treatment that suppresses inflammation by suppressing the innate immune system. External and mechanical factors that lead to inflammation are a door for pathogenic opportunity. Current research associates the presence of fungi in the etiology of AD and is shown in cerebral tissue at autopsy. From the time of the discovery of AD, much speculation exists for an infective cause. Identifying any AD disease organism is obscured by processes that can take place over years. Amyloid protein deposits are generally considered to be evidence of an intrinsic response to stress or imbalance, but instead amyloid may be evidence of the innate immune response which exists to destroy fungal colonization through structural interference and cytotoxicity. Fungi can remain ensconced for a long time in niches or inside cells, and it is the harboring of fungi that leads to repeated reinfection and slow wider colonization that eventually leads to a grave outcome. Although many fungi and bacteria are associated with AD affected tissues, discussion here focuses on Candida albicans as the archetype of human fungal pathology because of its wide proliferation as a commensal fungus, extensive published research, numerous fungal morphologies, and majority proliferation in AD tissues.
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Affiliation(s)
- Bodo Parady
- Children's Hospital Oakland Research Institute, Oakland, CA, USA.,Visiting Scholar, University of California, Berkeley, Berkeley CA, USA
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26
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A Genome-Wide Screen of Deletion Mutants in the Filamentous Saccharomyces cerevisiae Background Identifies Ergosterol as a Direct Trigger of Macrophage Pyroptosis. mBio 2018; 9:mBio.01204-18. [PMID: 30065091 PMCID: PMC6069111 DOI: 10.1128/mbio.01204-18] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Phagocytic cells such as macrophages play an important role in the host defense mechanisms mounted in response to the common human fungal pathogen Candida albicans. In vitro, C. albicans triggers macrophage NLRP3-Casp1/11-mediated pyroptosis, an inflammatory programmed cell death pathway. Here, we provide evidence that Casp1/11-dependent pyroptosis occurs in the kidney of infected mice during the early stages of infection. We have also used a genome-wide screen of nonessential Σ1278b Saccharomyces cerevisiae genes to identify genes required for yeast-triggered macrophage pyroptosis. The set of genes identified by this screen was enriched for those with functions in lipid and sterol homeostasis and trafficking. These observations led us to discover that cell surface localization and/or total levels of ergosterol correlate with the ability of S. cerevisiae, C. albicans, and Cryptococcus neoformans to trigger pyroptosis. Since the mammalian sterol cholesterol triggers NLRP3-mediated pyroptosis, we hypothesized that ergosterol may also do so. Consistent with that hypothesis, ergosterol-containing liposomes but not ergosterol-free liposomes induce pyroptosis. Cell wall mannoproteins directly bind ergosterol, and we found that Dan1, an ergosterol receptor mannoprotein, as well as specific mannosyltransferases, is required for pyroptosis, suggesting that cell wall-associated ergosterol may mediate the process. Taken together, these data indicate that ergosterol, like mammalian cholesterol, plays a direct role in yeast-mediated pyroptosis. Innate immune cells such as macrophages are key components of the host response to the human fungal pathogen Candida albicans. Macrophages undergo pyroptosis, an inflammatory, programmed cell death, in response to some species of pathogenic yeast. Prior to the work described in this report, yeast-triggered pyroptosis has been observed only in vitro; here, we show that pyroptosis occurs in the initial stages of murine kidney infection, suggesting that it plays an important role in the initial response of the innate immune system to invasive yeast infection. We also show that a key component of the fungal plasma membrane, ergosterol, directly triggers pyroptosis. Ergosterol is also present in the fungal cell wall, most likely associated with mannoproteins, and is increased in hyphal cells compared to yeast cells. Our data indicate that specific mannoproteins are required for pyroptosis. This is consistent with a potential mechanism whereby ergosterol present in the outer mannoprotein layer of the cell wall is accessible to the macrophage-mediated process. Taken together, our data provide the first evidence that ergosterol plays a direct role in the host-pathogen interactions of fungi.
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27
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Tucey TM, Verma J, Harrison PF, Snelgrove SL, Lo TL, Scherer AK, Barugahare AA, Powell DR, Wheeler RT, Hickey MJ, Beilharz TH, Naderer T, Traven A. Glucose Homeostasis Is Important for Immune Cell Viability during Candida Challenge and Host Survival of Systemic Fungal Infection. Cell Metab 2018; 27:988-1006.e7. [PMID: 29719235 PMCID: PMC6709535 DOI: 10.1016/j.cmet.2018.03.019] [Citation(s) in RCA: 137] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 12/18/2017] [Accepted: 03/26/2018] [Indexed: 12/20/2022]
Abstract
To fight infections, macrophages undergo a metabolic shift whereby increased glycolysis fuels antimicrobial inflammation and killing of pathogens. Here we demonstrate that the pathogen Candida albicans turns this metabolic reprogramming into an Achilles' heel for macrophages. During Candida-macrophage interactions intertwined metabolic shifts occur, with concomitant upregulation of glycolysis in both host and pathogen setting up glucose competition. Candida thrives on multiple carbon sources, but infected macrophages are metabolically trapped in glycolysis and depend on glucose for viability: Candida exploits this limitation by depleting glucose, triggering rapid macrophage death. Using pharmacological or genetic means to modulate glucose metabolism of host and/or pathogen, we show that Candida infection perturbs host glucose homeostasis in the murine candidemia model and demonstrate that glucose supplementation improves host outcomes. Our results support the importance of maintaining glucose homeostasis for immune cell survival during Candida challenge and for host survival in systemic infection.
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Affiliation(s)
- Timothy M Tucey
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800, VIC, Australia
| | - Jiyoti Verma
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800, VIC, Australia
| | - Paul F Harrison
- Bioinformatics Platform, Monash University, Clayton 3800, VIC, Australia
| | - Sarah L Snelgrove
- Centre for Inflammatory Diseases, Monash University Department of Medicine, Monash Medical Centre, Clayton 3168, VIC, Australia
| | - Tricia L Lo
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800, VIC, Australia
| | - Allison K Scherer
- Department of Molecular & Biomedical Sciences, University of Maine, Orono, ME, USA
| | - Adele A Barugahare
- Bioinformatics Platform, Monash University, Clayton 3800, VIC, Australia
| | - David R Powell
- Bioinformatics Platform, Monash University, Clayton 3800, VIC, Australia
| | - Robert T Wheeler
- Department of Molecular & Biomedical Sciences, University of Maine, Orono, ME, USA
| | - Michael J Hickey
- Centre for Inflammatory Diseases, Monash University Department of Medicine, Monash Medical Centre, Clayton 3168, VIC, Australia
| | - Traude H Beilharz
- Development and Stem Cells Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800, VIC, Australia
| | - Thomas Naderer
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800, VIC, Australia.
| | - Ana Traven
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800, VIC, Australia.
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28
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Abstract
Modulation of inflammasomes has tremendous therapeutic potential and is hotly pursued by industry and academia alike. Indeed a growing number of patents are emerging to protect the intellectual property in valuable compound classes. This chapter focusses specifically on the suite of small-molecule NLRP3 inflammasome inhibitors published, as specific modulation of other inflammasomes is not yet well established. Synthetic molecules, known drugs and natural product NLRP3 modulators will be detailed. Some of the molecular classes discussed have been extensively characterised through cell-based screening, pharmacokinetic profiling and therapeutic proof of concept animal models. However, many inhibitors lack rigorous studies and/or have multiple activities of which NLRP3 modulation is only one. While this is not intended as an exhaustive list, it should give an impression of the range of structures and strategies that are being used, alongside challenges encountered, in an effort to exploit the significant therapeutic benefits of targeting inflammasomes.
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Affiliation(s)
- Avril A B Robertson
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia.
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29
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Verma S, Shakya VPS, Idnurm A. Exploring and exploiting the connection between mitochondria and the virulence of human pathogenic fungi. Virulence 2018; 9:426-446. [PMID: 29261004 PMCID: PMC5955198 DOI: 10.1080/21505594.2017.1414133] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 12/04/2017] [Accepted: 12/04/2017] [Indexed: 12/17/2022] Open
Abstract
Mitochondria are best known for their role in the production of ATP; however, recent research implicates other mitochondrial functions in the virulence of human pathogenic fungi. Inhibitors of mitochondrial succinate dehydrogenase or the electron transport chain are successfully used to combat plant pathogenic fungi, but similar inhibition of mitochondrial functions has not been pursued for applications in medical mycology. Advances in understanding mitochondrial function relevant to human pathogenic fungi are in four major directions: 1) the role of mitochondrial morphology in virulence, 2) mitochondrial genetics, with a focus on mitochondrial DNA recombination and mitochondrial inheritance 3) the role of mitochondria in drug resistance, and 4) the interaction of mitochondria with other organelles. Collectively, despite the similarities in mitochondrial functions between fungi and animals, this organelle is currently an under-explored potential target to treat medical mycoses. Future research could define and then exploit those mitochondrial components best suited as drug targets.
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Affiliation(s)
- Surbhi Verma
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Viplendra P. S. Shakya
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Alexander Idnurm
- School of BioSciences, University of Melbourne, Parkville, VIC, Australia
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30
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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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31
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Court DA, Khetoo S, Shuvo SR, Reitmeier SD, Hausner G. In silico analysis of coevolution among ERMES proteins, Pex11, and Lam6. Can J Microbiol 2017; 63:984-997. [PMID: 28985476 DOI: 10.1139/cjm-2017-0460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In eukaryotic cells, communication and dynamic interactions among different organelles are important for maintaining cellular homeostasis. The endoplasmic reticulum (ER) mitochondria encounter structure (ERMES) complex establishes membrane contact sites between ER and mitochondria and is essential for phospholipid transport, protein import, and mitochondrial dynamics and inheritance. In this work, in silico analyses were used to probe the intramolecular interactions in ERMES proteins and the interactions that support the ERMES complex. Based on mutual information (MI), sites of intramolecular coevolution are predicted in the core proteins Mmm1, Mdm10, Mdm12, Mdm34, the peroxisomal protein Pex11, and cytoplasmic Lam6; these sites are linked to structural features of the proteins. Intermolecular coevolution is predicted among the synaptotagmin-like mitochondrial lipid-binding protein (SMP) domains of Mmm1, Mdm12, and Mdm34. Segments of Pex11 and Lam6 also share MI with the SMP domains of Mmm1 and Mdm12 and with the N terminus of Mdm34, implicating Mdm34 as part of a hub for interactions between ERMES and other complexes. In contrast, evidence of limited intermolecular coevolution involving the outer membrane protein Mdm10 was detected only with Mmm1 and Pex11. The results support models for the organization of these interacting proteins and suggest roles for Pex11 and Lam6 in regulating complex formation.
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Affiliation(s)
- Deborah A Court
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.,Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Shivani Khetoo
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.,Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Sabbir R Shuvo
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.,Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Shayne D Reitmeier
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.,Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Georg Hausner
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.,Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
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32
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A mitochondrial proteomics view of complex I deficiency in Candida albicans. Mitochondrion 2017; 38:48-57. [PMID: 28801230 DOI: 10.1016/j.mito.2017.08.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 08/01/2017] [Accepted: 08/07/2017] [Indexed: 12/28/2022]
Abstract
Proteomic analyses were carried out on isolated mitochondrial samples of C. albicans from gene-deleted mutants (nuo1Δ, nuo2Δ and goa1Δ) as well as the parental strain in order to better understand the contribution of these three fungal-specific mitochondrial ETC complex I (CI) subunits to cellular activities. Herein, we identify 2333 putative proteins from four strains, in which a total of 663 proteins (28.5%) are putatively located in mitochondria. Comparison of protein abundances between mutants and the parental strain reveal 146 differentially-expressed proteins, of which 78 are decreased and 68 are increased in at least one mutant. The common changes across the three mutants include the down-regulation of nuclear-encoded CI subunit proteins as well as phospholipid, ergosterol and cell wall mannan synthesis, and up-regulated proteins in CIV and the alternative oxidase (AOX2). As for gene-specific functions, we find that NUO1 participates in nucleotide synthesis and ribosomal biogenesis; NUO2 is involved in vesicle trafficking; and GOA1 appears to regulate membrane transporter proteins, ROS removal, and substrates trafficking between peroxisomes and mitochondria. The proteomic view of general as well as mutant-specific proteins further extends our understanding of the functional roles of non-mammalian CI-specific subunit proteins in cell processes. Particularly intriguing is the confirmation of a regulatory role for GOA1 on ETC function, a protein found almost exclusively in Candida species. SIGNIFICANCE Fungal mitochondria are critical for fungal pathogenesis. The absence of any of the three fungal specific CI subunits in mitochondria causes an avirulence phenotype of C. albicans in a murine model of invasive disease. As model yeast (Saccharomyces cerevisiae) lacks a CI and is rarely a pathogen of humans, C. albicans is a better choice for establishing a link between mitochondrial CI and pathogenesis. Apart from the general effects of CI mutants on respiration, previous phenotyping of these mutants were quite similar to each other or to CI conservative subunit. By comparison to transcriptional data, the proteomic data obtained in this study indicate that biosynthetic events in each mutant such as cell wall and cell membrane phospholipids and ergosterol are generally decreased in both transcriptomal and translational levels. However, in the case of mitochondrial function, glycolysis/gluconeogenesis, and ROS scavengers, often gene changes are opposite that of proteomic data in mutants. We hypothesize that the loss of energy production in mutants is compensated by increases in protein levels of glycolysis, gluconeogenesis, and anti-ROS scavengers that at least extend mutant survival.
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33
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Geißel B, Penka M, Neubauer M, Wagener J. The ER-mitochondria encounter structure contributes to hyphal growth, mitochondrial morphology and virulence of the pathogenic mold Aspergillus fumigatus. Int J Med Microbiol 2017; 307:37-43. [DOI: 10.1016/j.ijmm.2016.11.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 11/10/2016] [Accepted: 11/20/2016] [Indexed: 11/15/2022] Open
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34
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Marcos CM, de Oliveira HC, de Melo WDCMA, da Silva JDF, Assato PA, Scorzoni L, Rossi SA, de Paula E Silva ACA, Mendes-Giannini MJS, Fusco-Almeida AM. Anti-Immune Strategies of Pathogenic Fungi. Front Cell Infect Microbiol 2016; 6:142. [PMID: 27896220 PMCID: PMC5108756 DOI: 10.3389/fcimb.2016.00142] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 10/13/2016] [Indexed: 12/24/2022] Open
Abstract
Pathogenic fungi have developed many strategies to evade the host immune system. Multiple escape mechanisms appear to function together to inhibit attack by the various stages of both the adaptive and the innate immune response. Thus, after entering the host, such pathogens fight to overcome the immune system to allow their survival, colonization and spread to different sites of infection. Consequently, the establishment of a successful infectious process is closely related to the ability of the pathogen to modulate attack by the immune system. Most strategies employed to subvert or exploit the immune system are shared among different species of fungi. In this review, we summarize the main strategies employed for immune evasion by some of the major pathogenic fungi.
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Affiliation(s)
- Caroline M Marcos
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Faculdade de Ciências Farmacêuticas, Univ Estadual Paulista São Paulo, Brasil
| | - Haroldo C de Oliveira
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Faculdade de Ciências Farmacêuticas, Univ Estadual Paulista São Paulo, Brasil
| | - Wanessa de Cássia M Antunes de Melo
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Faculdade de Ciências Farmacêuticas, Univ Estadual Paulista São Paulo, Brasil
| | - Julhiany de Fátima da Silva
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Faculdade de Ciências Farmacêuticas, Univ Estadual Paulista São Paulo, Brasil
| | - Patrícia A Assato
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Faculdade de Ciências Farmacêuticas, Univ Estadual Paulista São Paulo, Brasil
| | - Liliana Scorzoni
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Faculdade de Ciências Farmacêuticas, Univ Estadual Paulista São Paulo, Brasil
| | - Suélen A Rossi
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Faculdade de Ciências Farmacêuticas, Univ Estadual Paulista São Paulo, Brasil
| | - Ana C A de Paula E Silva
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Faculdade de Ciências Farmacêuticas, Univ Estadual Paulista São Paulo, Brasil
| | - Maria J S Mendes-Giannini
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Faculdade de Ciências Farmacêuticas, Univ Estadual Paulista São Paulo, Brasil
| | - Ana M Fusco-Almeida
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Faculdade de Ciências Farmacêuticas, Univ Estadual Paulista São Paulo, Brasil
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