1
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Zheng D, Zhang X, Ding J, Yue D, Yang F, Li Y. Mechanisms and regulation of iron uptake and the role of iron in pathogenesis of Candida albicans. Crit Rev Microbiol 2025:1-18. [PMID: 40411301 DOI: 10.1080/1040841x.2025.2510256] [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: 11/17/2024] [Revised: 03/25/2025] [Accepted: 05/19/2025] [Indexed: 05/26/2025]
Abstract
Candida albicans is a primary pathogen implicated in invasive fungal infections. Through its intricate iron uptake and regulatory systems, C. albicans adeptly adapts to various iron-rich environments, circumventing the growth and virulence restrictions imposed by the host's nutritional immunity and intensifying infection severity. This fungus activates the Sef1-Sfu1-Hap43 iron homeostasis regulatory circuit via iron bioavailability sensors (iron-sulfur cluster assembly system). This activation precisely regulates multiple iron uptake pathways, including the high-affinity iron reduction system, heme-iron uptake pathway, and siderophore uptake system, as well as genes involved in iron utilization and storage, thus ensuring effective iron acquisition and maintaining iron homeostasis across diverse environmental conditions and developmental stages. Conversely, disruptions in iron metabolism markedly diminish C. albicans's pathogenic potential by impairing mitochondrial function, suppressing hyphal formation, limiting fungal colonization, and reversing antifungal drug resistance. This review presents a comprehensive analysis of the mechanisms governing iron uptake and regulation in C. albicans and examines the consequences of impaired iron homeostasis on mitochondrial function, hyphal formation, infection progression, and drug resistance. Our goal is to provide a theoretical framework to better understand the pathogenesis of C. albicans and to support the development of targeted therapeutic strategies against this resilient pathogen.
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Affiliation(s)
- Dongming Zheng
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Department of Nuclear Medicine, Ya'an People's Hospital, Ya'an, China
| | - Xiaoli Zhang
- Department of Cardiovascular Medicine, Ya'an Second People's Hospital, Ya'an, China
| | - Junping Ding
- Department of Cardiovascular Medicine, Ya'an Second People's Hospital, Ya'an, China
| | - Daifan Yue
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Fuzhou Yang
- Department of Nuclear Medicine, Ya'an People's Hospital, Ya'an, China
| | - Yan Li
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu, China
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2
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Zeise KD, Erb-Downward JR, Huffnagle GB. Transcriptomic insights into Candida albicans adaptation to an anaerobic environment. Microbiol Spectr 2025:e0302424. [PMID: 40401963 DOI: 10.1128/spectrum.03024-24] [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: 12/02/2024] [Accepted: 04/10/2025] [Indexed: 05/23/2025] Open
Abstract
Candida albicans is a clinically significant fungal pathogen capable of adapting to diverse host environments, including steep oxygen gradients ranging from ~21% oxygen to anaerobic. The ability to withstand varied oxygen levels is paramount to establishing colonization and persisting in host niches, and oxygen deprivation can also augment antifungal resistance. In this study, we used RNA sequencing to compare the global transcriptomic profiles of two strains of C. albicans (SC5314 and CHN1) grown purely anaerobically to those grown aerobically. In C. albicans SC5314, we observed a strong induction of the alternative oxidase AOX2 and several genes encoding subunits of mitochondrial enzyme complexes I, II, and V, signifying a shift to alternative respiration. Consistent with the diminished ATP production from this process, there was a significant downregulation of genes associated with growth and metabolism, including histones and ribosomal proteins, as well as chitinases and other genes involved in cell wall remodeling. Interestingly, the anaerobic C. albicans cultures had decreased expression of candidalysin (ECE1) and other virulence factors, contrasting with other studies reporting enhanced pathogenicity under oxygen deprivation. There were a greater number of significantly upregulated genes in C. albicans CHN1 compared to SC5314; however, most of the top 50 upregulated genes under anaerobic conditions were consistent between the two strains. The predominant difference in down-regulated genes between the two strains could be mapped to differences in hyphal transformation under aerobic conditions. Overall, our study provides a window into the molecular mechanisms of C. albicans adaptation between aerobic to anaerobic environments.IMPORTANCECandida albicans is a leading cause of fungal infections in humans, posing significant clinical challenges due to its remarkable adaptability and increasing antifungal resistance. Anaerobic environments can promote antifungal resistance, necessitating a deeper understanding of how C. albicans adapts to anoxia. While much research has been done to identify mechanisms underlying adaptation to hypoxia (i.e., low oxygen), this is the first study evaluating the global transcriptomic response of C. albicans to anoxia (no oxygen). Here, we uncover key transcriptomic changes that enable C. albicans to survive in the absence of oxygen, which are distinct from those identified under hypoxic conditions. Our research addresses a gap in current knowledge that may be exploited for combatting antifungal resistance.
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Affiliation(s)
- Karen D Zeise
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, USA
- Mary H. Weiser Food Allergy Center, University of Michigan, Ann Arbor, Michigan, USA
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - John R Erb-Downward
- Mary H. Weiser Food Allergy Center, University of Michigan, Ann Arbor, Michigan, USA
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
- Division of Pulmonary and Critical Care Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Gary B Huffnagle
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, USA
- Mary H. Weiser Food Allergy Center, University of Michigan, Ann Arbor, Michigan, USA
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
- Division of Pulmonary and Critical Care Medicine, University of Michigan, Ann Arbor, Michigan, USA
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3
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Arekar T, Katikaneni D, Kasem S, Desai D, Acharya T, Cole A, Khodayari N, Vaulont S, Hube B, Nemeth E, Drakesmith A, Lionakis MS, Mehrad B, Scindia Y. Essential role of hepcidin in host resistance to disseminated candidiasis. Cell Rep 2025; 44:115649. [PMID: 40333187 DOI: 10.1016/j.celrep.2025.115649] [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: 10/14/2024] [Revised: 02/20/2025] [Accepted: 04/11/2025] [Indexed: 05/09/2025] Open
Abstract
Candida albicans is a leading cause of life-threatening invasive infection despite antifungal therapy. Patients with chronic liver disease are at increased risk of candidemia, but the mechanisms underlying this susceptibility are incompletely defined. One consequence of chronic liver disease is an attenuated ability to produce hepcidin and maintain organismal control of iron homeostasis. To address the biology underlying this critical clinical problem, we demonstrate the mechanistic link between hepcidin insufficiency and candida infection using genetic and inducible hepcidin knockout mice. Hepcidin deficiency led to unrestrained fungal growth and increased transition to the invasive hypha morphology with exposed 1,3-β-glucan, which exacerbated kidney injury, independent of the fungal pore-forming toxin candidalysin in immunocompetent mice. Of translational relevance, the therapeutic administration of PR-73, a hepcidin mimetic, improved the outcome of infection. Thus, we identify hepcidin deficiency as a host susceptibility factor against C. albicans and hepcidin mimetics as a potential intervention.
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Affiliation(s)
- Tanmay Arekar
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, FL, USA
| | - Divya Katikaneni
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, FL, USA
| | - Sadat Kasem
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, FL, USA
| | - Dhruv Desai
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, FL, USA
| | - Thrisha Acharya
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, FL, USA
| | - Augustina Cole
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, FL, USA
| | - Nazli Khodayari
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, FL, USA
| | - Sophie Vaulont
- Université Paris Cité, CNRS, INSERM, Institut Cochin, Paris, France
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Elizabeta Nemeth
- Center for Iron Disorders, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Alexander Drakesmith
- MRC Translational Immune Discovery Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Michail S Lionakis
- Fungal Pathogenesis Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health, Bethesda, MD, USA
| | - Borna Mehrad
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, FL, USA
| | - Yogesh Scindia
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, FL, USA; Center for Integrated Cardiovascular and Metabolic Disease, University of Florida, Gainesville, FL, USA.
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4
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Ware A, Johnston W, Delaney C, Butcher MC, Ramage G, Price L, Butcher J, Kean R. Dry Surface Biofilm Formation by Candida auris Facilitates Persistence and Tolerance to Sodium Hypochlorite. APMIS 2025; 133:e70022. [PMID: 40194790 PMCID: PMC11975465 DOI: 10.1111/apm.70022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2025] [Revised: 03/19/2025] [Accepted: 03/23/2025] [Indexed: 04/09/2025]
Abstract
Candida auris is an enigmatic fungal pathogen, recently elevated as a critical priority group pathogen by the World Health Organisation, linked with its ability to cause outbreaks within nosocomial care units, facilitated through environmental persistence. We investigated the susceptibility of phenotypically distinct C. auris isolates to sodium hypochlorite (NaOCl), and evaluated the role of biofilms in surviving disinfection using a dry-surface biofilm (DSB) model and transcriptomic profiling. Planktonic cells were tested for susceptibility to NaOCl, with biofilm formation using the 12-day DSB model, assessed using viable counts, biomass assays and microscopy. Disinfection efficacy was assessed using clinical protocols of 500-1,000 ppm for 1-5 min. RNA sequencing was performed on untreated DSBs in comparison to planktonic cells. Isolates were found to be susceptible planktonically, but grew NaOCl-tolerant biofilms, with only 2-4 log10 reductions in viable cells observed at highest concentrations. Transcriptomics identified DSB upregulation of ABC transporters and iron acquisition pathways relative to planktonic cells. Our findings optimized a DSB protocol in which C. auris can mediate tolerance to NaOCl disinfection, suggesting a lifestyle through which this problematic yeast can environmentally persist. Mechanistically, it has been shown for the first time that upregulation of small-molecule and iron transport pathways are potential facilitators of environmental survival.
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Affiliation(s)
- Alicia Ware
- Department of Biological and Biomedical SciencesGlasgow Caledonian UniversityGlasgowUK
- Safeguarding Health Through Infection Prevention Research Group, Research Centre for Health (ReaCH)Glasgow Caledonian UniversityGlasgowUK
| | - William Johnston
- Department of Biological and Biomedical SciencesGlasgow Caledonian UniversityGlasgowUK
- Safeguarding Health Through Infection Prevention Research Group, Research Centre for Health (ReaCH)Glasgow Caledonian UniversityGlasgowUK
| | | | - Mark C. Butcher
- Safeguarding Health Through Infection Prevention Research Group, Research Centre for Health (ReaCH)Glasgow Caledonian UniversityGlasgowUK
| | - Gordon Ramage
- Safeguarding Health Through Infection Prevention Research Group, Research Centre for Health (ReaCH)Glasgow Caledonian UniversityGlasgowUK
| | - Lesley Price
- Safeguarding Health Through Infection Prevention Research Group, Research Centre for Health (ReaCH)Glasgow Caledonian UniversityGlasgowUK
| | - John Butcher
- Department of Biological and Biomedical SciencesGlasgow Caledonian UniversityGlasgowUK
- Safeguarding Health Through Infection Prevention Research Group, Research Centre for Health (ReaCH)Glasgow Caledonian UniversityGlasgowUK
| | - Ryan Kean
- Department of Biological and Biomedical SciencesGlasgow Caledonian UniversityGlasgowUK
- Safeguarding Health Through Infection Prevention Research Group, Research Centre for Health (ReaCH)Glasgow Caledonian UniversityGlasgowUK
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5
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Yue D, Zheng D, Yang L, Bai Y, Song Z, Li D, Yu X, Li Y. Berberine disrupts the high-affinity iron transport system to reverse the fluconazole-resistance in Candida albicans. Microb Pathog 2025; 200:107370. [PMID: 39929396 DOI: 10.1016/j.micpath.2025.107370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2024] [Revised: 01/31/2025] [Accepted: 02/07/2025] [Indexed: 02/14/2025]
Abstract
Invasive fungal infection is usually caused by Candida albicans infection, which has a high incidence rate and mortality in critically ill patients. New drugs are needed to combat this pathogen since the limited treatment options currently available and increasing resistance to existing drugs. Berberine (BBR) is an active compound in Coptis chinensis, Phellodendron chinense and Radix berberidis, which is clinically used to treat inflammatory bowel disease, but its inhibitory effect on drug-resistant fungi has not been clarified. In this study, based on the evidence of BBR inhibiting the expression of azole-resistance genes, reducing cell adhesion and disrupting biofilm formation, transcriptome analysis revealed that the disruption of iron acquisition pathway may be the core link in BBR inhibiting drug-resistant fungi. Combined with the subsequent experimental results, including the reduction of intracellular ferrous ion content, the weakening of iron reductase activity and the overall downregulation of the coding gene of the high-affinity iron reduction system, it is speculated that the fungal growth defect under BBR treatment is the result of the interruption of the high-affinity iron acquisition pathway. Ftr1 plays a central role in the drug targeting of this transport system. Meanwhile, due to the iron deficiency within the cell, the biological function of mitochondria is impaired, ultimately leading to fungal death. This study not only reflects the application value of BBR in the clinical treatment of fungal infections, but also provides a potential strategy to address the current drug-resistance dilemma.
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Affiliation(s)
- Daifan Yue
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Dongming Zheng
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China; Department of Nuclear Medicine, Ya'an People's Hospital, Ya'an, 625000, China
| | - Linlan Yang
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Yuxin Bai
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Zhen Song
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Dongmei Li
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Xiaoqin Yu
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.
| | - Yan Li
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.
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6
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Praetorius JP, Hitzler SUJ, Gresnigt MS, Figge MT. Image-based quantification of Candida albicans filamentation and hyphal length using the open-source visual programming language JIPipe. FEMS Yeast Res 2025; 25:foaf011. [PMID: 40082735 PMCID: PMC11963753 DOI: 10.1093/femsyr/foaf011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2024] [Revised: 02/28/2025] [Accepted: 03/12/2025] [Indexed: 03/16/2025] Open
Abstract
The formation of hyphae is one of the most crucial virulence traits the human pathogenic fungus Candida albicans possesses. The assessment of hyphal length in response to various stimuli, such as exposure to human serum, provides valuable insights into the adaptation strategies of C. albicans to the host environment. Despite the increasing high-throughput capacity live-cell imaging and data generation, the accurate analysis of hyphal growth has remained a laborious, error-prone, and subjective manual process. We developed an analysis pipeline utilizing the open-source visual programming language Java Image Processing Pipeline (JIPipe) to overcome the limitations associated with manual analysis of hyphal growth. By comparing our automated approach with manual analysis, we refined the strategies to achieve accurate differentiation between yeast cells and hyphae. The automated method enables length measurements of individual hyphae, facilitating a time-efficient, high-throughput, and user-friendly analysis. By utilizing this JIPipe analysis approach, we obtained insights into the filamentation behavior of two C. albicans strains when exposed to human serum albumin (HSA), the most abundant protein in human serum. Our findings indicate that despite the known role of HSA in stimulating fungal growth, it reduces filamentous growth. The implementation of our automated JIPipe analysis approach for hyphal growth represents a long-awaited and time-efficient solution to meet the demand of high-throughput data generation. This tool can benefit different research areas investigating the virulence aspects of C. albicans.
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Affiliation(s)
- Jan-Philipp Praetorius
- Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), 07745 Jena, Germany
| | - Sophia U J Hitzler
- Junior Research Group Adaptive Pathogenicity Strategies, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (Leibniz-HKI), 07745 Jena, Germany
| | - Mark S Gresnigt
- Junior Research Group Adaptive Pathogenicity Strategies, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (Leibniz-HKI), 07745 Jena, Germany
| | - Marc Thilo Figge
- Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), 07745 Jena, Germany
- Institute of Microbiology, Faculty of Biological Sciences, Friedrich Schiller University Jena, 07745 Jena, Germany
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7
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Patel NK, David MS, Yang S, Garg R, Zhao H, Cormack BP, Culotta VC. Converging Roles of the Metal Transporter SMF11 and the Ferric Reductase FRE1 in Iron Homeostasis of Candida albicans. Mol Microbiol 2024; 122:879-895. [PMID: 39529282 DOI: 10.1111/mmi.15326] [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: 07/22/2024] [Revised: 10/07/2024] [Accepted: 10/15/2024] [Indexed: 11/16/2024]
Abstract
Pathogenic fungi must appropriately sense the host availability of essential metals such as Fe. In Candida albicans and other yeasts, sensing of Fe involves mitochondrial Fe-S clusters. Yeast mutants for Fe-S cluster assembly sense Fe limitation even when Fe is abundant and hyperaccumulate Fe. We observe this same disrupted Fe sensing with C. albicans mutants of SMF11, a NRAMP transporter of divalent metals. Mutants of smf11 hyperaccumulate both Mn and Fe and the elevated Mn is secondary to Fe overload. As with Fe-S biogenesis mutants, smf11∆/∆ mutants show upregulation of ferric reductases that are normally repressed under high Fe, and Fe import is activated. However, unlike Fe-S biogenesis mutants, smf11∆/∆ mutants show no defects in mitochondrial Fe-S enzymes. Intriguingly, this exact condition of disrupted Fe sensing without inhibiting Fe-S clusters occurs with C. albicans fre1∆/∆ mutants encoding a ferric reductase. Mutants of fre1 and smf11 display similar perturbations in the cell wall, in filamentation and in the ROS burst of morphogenesis, a Fe-dependent process. As with FRE1, SMF11 is important for virulence in a mouse model for disseminated candidiasis. We propose a model in which FRE1 and SMF11 operate outside the mitochondrial Fe-S pathway to donate ferrous Fe for Fe sensing.
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Affiliation(s)
- Naisargi K Patel
- Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Marika S David
- Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Shuyi Yang
- Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Ritu Garg
- Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Hongyu Zhao
- Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Brendan P Cormack
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Valeria C Culotta
- Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
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8
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Arekar T, Katikaneni D, Kasem S, Desai D, Acharya T, Cole A, Khodayari N, Vaulont S, Hube B, Nemeth E, Drakesmith A, Lionakis MS, Mehrad B, Scindia Y. Essential role of Hepcidin in host resistance to disseminated candidiasis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.10.29.620511. [PMID: 39553949 PMCID: PMC11565830 DOI: 10.1101/2024.10.29.620511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2024]
Abstract
Candida albicans is a leading cause of life-threatening invasive infections with up to 40% mortality rates in hospitalized individuals despite antifungal therapy. Patients with chronic liver disease are at an increased risk of candidemia, but the mechanisms underlying this susceptibility are incompletely defined. One consequence of chronic liver disease is attenuated ability to produce hepcidin and maintain organismal control of iron homeostasis. To address the biology underlying this critical clinical problem, we demonstrate the mechanistic link between hepcidin insufficiency and candida infection using genetic and inducible hepcidin knockout mice. Hepcidin deficiency led to unrestrained fungal growth and increased transition to the invasive hypha morphology with exposed 1,3, β-glucan that exacerbated kidney injury, independent of the fungal pore-forming toxin candidalysin in immunocompetent mice. Of translational relevance, the therapeutic administration of PR-73, a hepcidin mimetic, improved the outcomes of infection. Thus, we identify hepcidin deficiency as a novel host susceptibility factor against C. albicans and hepcidin mimetics as a potential intervention.
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9
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Kumar D, Kumar A. Molecular Determinants Involved in Candida albicans Biofilm Formation and Regulation. Mol Biotechnol 2024; 66:1640-1659. [PMID: 37410258 DOI: 10.1007/s12033-023-00796-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 06/14/2023] [Indexed: 07/07/2023]
Abstract
Candida albicans is known for its pathogenicity, although it lives within the human body as a commensal member. The commensal nature of C. albicans is well controlled and regulated by the host's immune system as they live in the harmonized microenvironment. However, the development of certain unusual microhabitat conditions (change in pH, co-inhabiting microorganisms' population ratio, debilitated host-immune system) pokes this commensal fungus to transform into a pathogen in such a way that it starts to propagate very rapidly and tries to breach the epithelial barrier to enter the host's systemic circulations. In addition, Candida is infamous as a major nosocomial (hospital-acquired infection) agent because it enters the human body through venous catheters or medical prostheses. The hysterical mode of C. albicans growth builds its microcolony or biofilm, which is pathogenic for the host. Biofilms propose additional resistance mechanisms from host immunity or extracellular chemicals to aid their survival. Differential gene expressions and regulations within the biofilms cause altered morphology and metabolism. The genes associated with adhesiveness, hyphal/pseudo-hyphal growth, persister cell transformation, and biofilm formation by C. albicans are controlled by myriads of cell-signaling regulators. These genes' transcription is controlled by different molecular determinants like transcription factors and regulators. Therefore, this review has focused discussion on host-immune-sensing molecular determinants of Candida during biofilm formation, regulatory descriptors (secondary messengers, regulatory RNAs, transcription factors) of Candida involved in biofilm formation that could enable small-molecule drug discovery against these molecular determinants, and lead to disrupt the well-structured Candida biofilms effectively.
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Affiliation(s)
- Dushyant Kumar
- Department of Biotechnology, National Institute of Technology, Raipur, Chhattisgarh, 492010, India
| | - Awanish Kumar
- Department of Biotechnology, National Institute of Technology, Raipur, Chhattisgarh, 492010, India.
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10
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Zheng D, Yue D, Shen J, Li D, Song Z, Huang Y, Yong J, Li Y. Berberine inhibits Candida albicans growth by disrupting mitochondrial function through the reduction of iron absorption. J Appl Microbiol 2023; 134:lxad276. [PMID: 37994672 DOI: 10.1093/jambio/lxad276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 11/04/2023] [Accepted: 11/21/2023] [Indexed: 11/24/2023]
Abstract
AIMS This study aimed to investigate whether berberine (BBR) can inhibit the iron reduction mechanism of Candida albicans, lowering the iron uptake of the yeast and perhaps having antimicrobial effects. METHODS AND RESULTS We determined that BBR may cause extensive transcriptional remodeling in C. albicans and that iron permease Ftr1 played a crucial role in this process through eukaryotic transcriptome sequencing. Mechanistic research showed that BBR might selectively inhibit the iron reduction pathway to lower the uptake of exogenous iron ions, inhibiting C. albicans from growing and metabolizing. Subsequent research revealed that BBR caused significant mitochondrial dysfunction, which triggered the process of mitochondrial autophagy. Moreover, we discovered that C. albicans redox homeostasis, susceptibility to antifungal drugs, and hyphal growth are all impacted by the suppression of this mechanism by BBR. CONCLUSIONS The iron reduction mechanism in C. albicans is disrupted by BBR, which disrupts mitochondrial function and inhibits fungal growth. These findings highlight the potential promise of BBR in antifungal applications.
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Affiliation(s)
- Dongming Zheng
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Sichuan 611137, China
| | - Daifan Yue
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Sichuan 611137, China
| | - Jinyang Shen
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Sichuan 611137, China
| | - Dongmei Li
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Sichuan 611137, China
| | - Zhen Song
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Sichuan 611137, China
| | - Yifu Huang
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Sichuan 611137, China
| | - Jiangyan Yong
- Hospital of Chengdu University of Traditional Chinese Medicine, Sichuan 610075, China
| | - Yan Li
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Sichuan 611137, China
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11
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van Wijlick L, Znaidi S, Hernández-Cervantes A, Basso V, Bachellier-Bassi S, d’Enfert C. Functional Portrait of Irf1 (Orf19.217), a Regulator of Morphogenesis and Iron Homeostasis in Candida albicans. Front Cell Infect Microbiol 2022; 12:960884. [PMID: 36004328 PMCID: PMC9393397 DOI: 10.3389/fcimb.2022.960884] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 07/18/2022] [Indexed: 11/17/2022] Open
Abstract
The alternate growth of Candida albicans between a unicellular yeast form and a multicellular hyphal form is crucial for its ability to cause disease. Interestingly, both morphological forms support distinct functions during proliferation in the human host. We previously identified ORF19.217 (C2_08890W_A), encoding a zinc-finger transcription factor of the C2H2 family, in a systematic screen of genes whose overexpression contributes to C. albicans' morphological changes. Conditional overexpression of ORF19.217 with the strong tetracycline-inducible promoter (P TET ) resulted in a hyperfilamentous phenotype. We examined growth of the orf19.217 knockout-mutant in different hypha-inducing conditions and found that the mutant still formed hyphae under standard hypha-inducing conditions. To further investigate the function of Orf19.217 in C. albicans, we combined genome-wide expression (RNA-Seq) and location (ChIP-Seq) analyses. We found that Orf19.217 is involved in regulatory processes comprising hyphal morphogenesis and iron acquisition. Comparative analysis with existing C. albicans hyphal transcriptomes indicates that Orf19.217-mediated filamentation is distinct from a true hyphal program. Further, the orf19.217 knockout-mutant did not show increased sensitivity to iron deprivation, but ORF19.217 overexpression was able to rescue the growth of a hap5-mutant, defective in a subunit of the CCAAT-complex, which is essential for iron acquisition. This suggested that Orf19.217 is involved in regulation of iron acquisition genes during iron deprivation and acts in a parallel pathway to the established CCAAT-complex. Interestingly, the orf19.217-mutant turned out to be defective in its ability to form filaments under iron-deficiency. Taken together our findings propose that the transcription factor Orf19.217 stimulates expression of the hyphal regulators EFG1 and BRG1 to promote filamentous growth under iron deprivation conditions, allowing the fungus to escape these iron-depleted conditions. The transcription factor therefore appears to be particularly important for adaptation of C. albicans to diverse environmental conditions in the human host. In regard to the newly identified functions, we have given the regulator the name Irf1, Iron-dependent Regulator of Filamentation.
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Affiliation(s)
- Lasse van Wijlick
- Institut Pasteur, Université Paris Cité, INRAE USC2019, Unité Biologie et Pathogénicité Fongiques, Paris, France
| | - Sadri Znaidi
- Institut Pasteur, Université Paris Cité, INRAE USC2019, Unité Biologie et Pathogénicité Fongiques, Paris, France
- Institut Pasteur de Tunis, Laboratoire de Microbiologie Moléculaire, Vaccinologie et Développement Biotechnologique, Tunis-Belvédère, Tunisia
| | - Arturo Hernández-Cervantes
- Institut Pasteur, Université Paris Cité, INRAE USC2019, Unité Biologie et Pathogénicité Fongiques, Paris, France
| | - Virginia Basso
- Institut Pasteur, Université Paris Cité, INRAE USC2019, Unité Biologie et Pathogénicité Fongiques, Paris, France
| | - Sophie Bachellier-Bassi
- Institut Pasteur, Université Paris Cité, INRAE USC2019, Unité Biologie et Pathogénicité Fongiques, Paris, France
| | - Christophe d’Enfert
- Institut Pasteur, Université Paris Cité, INRAE USC2019, Unité Biologie et Pathogénicité Fongiques, Paris, France
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Abstract
Candida albicans filamentation, the ability to convert from oval yeast cells to elongated hyphal cells, is a key factor in its pathogenesis. Previous work has shown that the integral membrane protein Dfi1 is required for filamentation in cells grown in contact with a semisolid surface. Investigations into the downstream targets of the Dfi1 pathway revealed potential links to two transcription factors, Sef1 and Czf1. Sef1 regulates iron uptake and iron utilization genes under low-iron conditions, leading us to hypothesize that there exists a link between iron availability and contact-dependent invasive filamentation. In this study, we showed that Sef1 was not required for contact-dependent filamentation, but it was required for wild-type (WT) expression levels of a number of genes during growth under contact conditions. Czf1 is required for contact-dependent filamentation and for WT levels of expression of several genes. Constitutive expression and activation of either Sef1 or Czf1 individually in a dfi1 null strain resulted in a complete rescue of the dfi1 null filamentation defect. Because Sef1 is normally activated in low-iron environments, we embedded WT and dfi1 null cells in iron-free agar medium supplemented with various concentrations of ferrous ammonium sulfate (FAS). dfi1 null cells embedded in media with a low concentration of iron (20 μM FAS) showed increased filamentation in comparison to mutant cells embedded in higher concentrations of iron (50 to 500 μM). WT cells produced filamentous colonies in all concentrations. Together, the data indicate that Dfi1, Czf1, Sef1, and environmental iron regulate C. albicans contact-dependent filamentation. IMPORTANCECandida albicans is an opportunistic pathogen responsible for a larger proportion of candidiasis and candidemia cases than any other Candida species. The ability of C. albicans cells to invade and cause disease is linked to their ability to filament. Despite this, there are gaps in our knowledge of the environmental cues and intracellular signaling that triggers the switch from commensal organism to filamentous pathogen. In this study, we identified a link between contact-dependent filamentation and iron availability. Over the course of tissue invasion, C. albicans cells encounter a number of different iron microenvironments, from the iron-rich gut to iron-poor tissues. Increased expression of Sef1-dependent iron uptake genes as a result of contact-dependent signaling will promote the adaptation of C. albicans cells to a low-iron-availability environment.
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