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Hefny ZA, Ji B, Elsemman IE, Nielsen J, Van Dijck P. Transcriptomic meta-analysis to identify potential antifungal targets in Candida albicans. BMC Microbiol 2024; 24:66. [PMID: 38413885 PMCID: PMC10898158 DOI: 10.1186/s12866-024-03213-8] [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: 09/29/2023] [Accepted: 02/06/2024] [Indexed: 02/29/2024] Open
Abstract
BACKGROUND Candida albicans is a fungal pathogen causing human infections. Here we investigated differential gene expression patterns and functional enrichment in C. albicans strains grown under different conditions. METHODS A systematic GEO database search identified 239 "Candida albicans" datasets, of which 14 were selected after rigorous criteria application. Retrieval of raw sequencing data from the ENA database was accompanied by essential metadata extraction from dataset descriptions and original articles. Pre-processing via the tailored nf-core pipeline for C. albicans involved alignment, gene/transcript quantification, and diverse quality control measures. Quality assessment via PCA and DESeq2 identified significant genes (FDR < = 0.05, log2-fold change > = 1 or <= -1), while topGO conducted GO term enrichment analysis. Exclusions were made based on data quality and strain relevance, resulting in the selection of seven datasets from the SC5314 strain background for in-depth investigation. RESULTS The meta-analysis of seven selected studies unveiled a substantial number of genes exhibiting significant up-regulation (24,689) and down-regulation (18,074). These differentially expressed genes were further categorized into 2,497 significantly up-regulated and 2,573 significantly down-regulated Gene Ontology (GO) IDs. GO term enrichment analysis clustered these terms into distinct groups, providing insights into the functional implications. Three target gene lists were compiled based on previous studies, focusing on central metabolism, ion homeostasis, and pathogenicity. Frequency analysis revealed genes with higher occurrence within the identified GO clusters, suggesting their potential as antifungal targets. Notably, the genes TPS2, TPS1, RIM21, PRA1, SAP4, and SAP6 exhibited higher frequencies within the clusters. Through frequency analysis within the GO clusters, several key genes emerged as potential targets for antifungal therapies. These include RSP5, GLC7, SOD2, SOD5, SOD1, SOD6, SOD4, SOD3, and RIM101 which exhibited higher occurrence within the identified clusters. CONCLUSION This comprehensive study significantly advances our understanding of the dynamic nature of gene expression in C. albicans. The identification of genes with enhanced potential as antifungal drug targets underpins their value for future interventions. The highlighted genes, including TPS2, TPS1, RIM21, PRA1, SAP4, SAP6, RSP5, GLC7, SOD2, SOD5, SOD1, SOD6, SOD4, SOD3, and RIM101, hold promise for the development of targeted antifungal therapies.
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Affiliation(s)
- Zeinab Abdelmoghis Hefny
- Laboratory of Molecular Cell Biology, Department of Biology, Katholieke Universiteit Leuven, Kasteelpark Arenberg 31, Leuven, B-3001, Belgium
| | - Boyang Ji
- BioInnovation Institute, Ole Maaløes Vej 3, Copenhagen, DK2200, Denmark
| | - Ibrahim E Elsemman
- Department of Information Systems, Faculty of Computers and Information, Assiut University, Assiut, 2071515, Egypt
| | - Jens Nielsen
- BioInnovation Institute, Ole Maaløes Vej 3, Copenhagen, DK2200, Denmark.
- Department of Life Sciences, Chalmers University of Technology, Kemivägen 10, SE41296, Gothenburg, SE41296, Sweden.
| | - Patrick Van Dijck
- Laboratory of Molecular Cell Biology, Department of Biology, Katholieke Universiteit Leuven, Kasteelpark Arenberg 31, Leuven, B-3001, Belgium.
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Ibe C, Munro CA. Fungal Cell Wall Proteins and Signaling Pathways Form a Cytoprotective Network to Combat Stresses. J Fungi (Basel) 2021; 7:jof7090739. [PMID: 34575777 PMCID: PMC8466366 DOI: 10.3390/jof7090739] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/01/2021] [Accepted: 09/04/2021] [Indexed: 12/13/2022] Open
Abstract
Candida species are part of the normal flora of humans, but once the immune system of the host is impaired and they escape from commensal niches, they shift from commensal to pathogen causing candidiasis. Candida albicans remains the primary cause of candidiasis, accounting for about 60% of the global candidiasis burden. The cell wall of C. albicans and related fungal pathogens forms the interface with the host, gives fungal cells their shape, and also provides protection against stresses. The cell wall is a dynamic organelle with great adaptive flexibility that allows remodeling, morphogenesis, and changes in its components in response to the environment. It is mainly composed of the inner polysaccharide rich layer (chitin, and β-glucan) and the outer protein coat (mannoproteins). The highly glycosylated protein coat mediates interactions between C. albicans cells and their environment, including reprograming of wall architecture in response to several conditions, such as carbon source, pH, high temperature, and morphogenesis. The mannoproteins are also associated with C. albicans adherence, drug resistance, and virulence. Vitally, the mannoproteins contribute to cell wall construction and especially cell wall remodeling when cells encounter physical and chemical stresses. This review describes the interconnected cell wall integrity (CWI) and stress-activated pathways (e.g., Hog1, Cek1, and Mkc1 mediated pathways) that regulates cell wall remodeling and the expression of some of the mannoproteins in C. albicans and other species. The mannoproteins of the surface coat is of great importance to pathogen survival, growth, and virulence, thus understanding their structure and function as well as regulatory mechanisms can pave the way for better management of candidiasis.
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Affiliation(s)
- Chibuike Ibe
- Department of Microbiology, Faculty of Biological Sciences, Abia State University, Uturu 441107, Nigeria
- Correspondence:
| | - Carol A. Munro
- Aberdeen Fungal Group, Institute of Medical Sciences, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen AB24 3FX, UK;
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Wagner AS, Hancock TJ, Lumsdaine SW, Kauffman SJ, Mangrum MM, Phillips EK, Sparer TE, Reynolds TB. Activation of Cph1 causes ß(1,3)-glucan unmasking in Candida albicans and attenuates virulence in mice in a neutrophil-dependent manner. PLoS Pathog 2021; 17:e1009839. [PMID: 34432857 PMCID: PMC8423308 DOI: 10.1371/journal.ppat.1009839] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 09/07/2021] [Accepted: 07/26/2021] [Indexed: 12/26/2022] Open
Abstract
Masking the immunogenic cell wall epitope ß(1,3)-glucan under an outer layer of mannosylated glycoproteins is an important virulence factor deployed by Candida albicans during infection. Consequently, increased ß(1,3)-glucan exposure (unmasking) reveals C. albicans to the host's immune system and attenuates its virulence. We have previously shown that activation of the Cek1 MAPK pathway via expression of a hyperactive allele of an upstream kinase (STE11ΔN467) induced unmasking. It also increased survival of mice in a murine disseminated candidiasis model and attenuated kidney fungal burden by ≥33 fold. In this communication, we utilized cyclophosphamide-induced immunosuppression to test if the clearance of the unmasked STE11ΔN467 mutant was dependent on the host immune system. Suppression of the immune response by cyclophosphamide reduced the attenuation in fungal burden caused by the STE11ΔN467 allele. Moreover, specific depletion of neutrophils via 1A8 antibody treatment also reduced STE11ΔN467-dependent fungal burden attenuation, but to a lesser extent than cyclophosphamide, demonstrating an important role for neutrophils in mediating fungal clearance of unmasked STE11ΔN467 cells. In an effort to understand the mechanism by which Ste11ΔN467 causes unmasking, transcriptomics were used to reveal that several components in the Cek1 MAPK pathway were upregulated, including the transcription factor CPH1 and the cell wall sensor DFI1. In this report we show that a cph1ΔΔ mutation restored ß(1,3)-glucan exposure to wild-type levels in the STE11ΔN467 strain, confirming that Cph1 is the transcription factor mediating Ste11ΔN467-induced unmasking. Furthermore, Cph1 is shown to induce a positive feedback loop that increases Cek1 activation. In addition, full unmasking by STE11ΔN467 is dependent on the upstream cell wall sensor DFI1. However, while deletion of DFI1 significantly reduced Ste11ΔN467-induced unmasking, it did not impact activation of the downstream kinase Cek1. Thus, it appears that once stimulated by Ste11ΔN467, Dfi1 activates a parallel signaling pathway that is involved in Ste11ΔN467-induced unmasking.
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Affiliation(s)
- Andrew S. Wagner
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Trevor J. Hancock
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Stephen W. Lumsdaine
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Sarah J. Kauffman
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Mikayla M. Mangrum
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Elise K. Phillips
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Timothy E. Sparer
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Todd B. Reynolds
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
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Anticandidal agent for multiple targets: the next paradigm in the discovery of proficient therapeutics/overcoming drug resistance. Future Med Chem 2019; 11:2955-2974. [DOI: 10.4155/fmc-2018-0479] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Candida albicans is a prominent human fungal pathogen. Current treatments are suffering a massive gap due to emerging resistance against available antifungals. Therefore, there is an ardent need for novel antifungal candidates that essentially have more than one target, as most antifungal repertoires are single-target drugs. Exploration of multiple-drug targeting in antifungal therapeutics is still pending. An extensive literature survey was performed to categorize and comprehend relevant studies and the current therapeutic scenario that led researchers to preferentially consider multitarget drug-based Candida infection therapy. With this article, we identified and compiled a few potent antifungal compounds that are directed toward multiple virulent targets in C. albicans. Such compound(s) provide an optimistic platform of multiple targeting and could leave a substantial impact on the development of effective antifungals.
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Chen T, Wagner AS, Tams RN, Eyer JE, Kauffman SJ, Gann ER, Fernandez EJ, Reynolds TB. Lrg1 Regulates β (1,3)-Glucan Masking in Candida albicans through the Cek1 MAP Kinase Pathway. mBio 2019; 10:e01767-19. [PMID: 31530671 PMCID: PMC6751057 DOI: 10.1128/mbio.01767-19] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 08/15/2019] [Indexed: 12/28/2022] Open
Abstract
Candida albicans is among the most prevalent opportunistic human fungal pathogens. The ability to mask the immunogenic polysaccharide β (1,3)-glucan from immune detection via a layer of mannosylated proteins is a key virulence factor of C. albicans We previously reported that hyperactivation of the Cek1 mitogen-activated protein (MAP) kinase pathway promotes β (1,3)-glucan exposure. In this communication, we report a novel upstream regulator of Cek1 activation and characterize the impact of Cek1 activity on fungal virulence. Lrg1 encodes a GTPase-activating protein (GAP) that has been suggested to inhibit the GTPase Rho1. We found that disruption of LRG1 causes Cek1 hyperactivation and β (1,3)-glucan unmasking. However, when GTPase activation was measured for a panel of GTPases, the lrg1ΔΔ mutant exhibited increased activation of Cdc42 and Ras1 but not Rho1 or Rac1. Unmasking and Cek1 activation in the lrg1ΔΔ mutant can be blocked by inhibition of the Ste11 MAP kinase kinase kinase (MAPKKK), indicating that the lrg1ΔΔ mutant acts through the canonical Cek1 MAP kinase cascade. In order to determine how Cek1 hyperactivation specifically impacts virulence, a doxycycline-repressible hyperactive STE11ΔN467 allele was expressed in C. albicans In the absence of doxycycline, this allele overexpressed STE11ΔN467 , which induced production of proinflammatory tumor necrosis factor alpha (TNF-α) from murine macrophages. This in vitro phenotype correlates with decreased colonization and virulence in a mouse model of systemic infection. The mechanism by which Ste11ΔN467 causes unmasking was explored with RNA sequencing (RNA-Seq) analysis. Overexpression of Ste11ΔN467 caused upregulation of the Cph1 transcription factor and of a group of cell wall-modifying proteins which are predicted to impact cell wall architecture.IMPORTANCECandida albicans is an important source of systemic infections in humans. The ability to mask the immunogenic cell wall polymer β (1,3)-glucan from host immune surveillance contributes to fungal virulence. We previously reported that the hyperactivation of the Cek1 MAP kinase cascade promotes cell wall unmasking, thus increasing strain immunogenicity. In this study, we identified a novel regulator of the Cek1 pathway called Lrg1. Lrg1 is a predicted GTPase-activating protein (GAP) that represses Cek1 activity by downregulating the GTPase Cdc42 and its downstream MAPKKK, Ste11. Upregulation of Cek1 activity diminished fungal virulence in the mouse model of infection, and this correlates with increased cytokine responses from macrophages. We also analyzed the transcriptional profile determined during β (1,3)-glucan exposure driven by Cek1 hyperactivation. Our report provides a model where Cek1 hyperactivation causes β (1,3)-glucan exposure by upregulation of cell wall proteins and leads to more robust immune detection in vivo, promoting more effective clearance.
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Affiliation(s)
- Tian Chen
- Department of Microbiology, The University of Tennessee, Knoxville, Tennessee, USA
| | - Andrew S Wagner
- Department of Microbiology, The University of Tennessee, Knoxville, Tennessee, USA
| | - Robert N Tams
- Department of Microbiology, The University of Tennessee, Knoxville, Tennessee, USA
| | - James E Eyer
- Department of Biochemistry & Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, USA
| | - Sarah J Kauffman
- Department of Microbiology, The University of Tennessee, Knoxville, Tennessee, USA
| | - Eric R Gann
- Department of Microbiology, The University of Tennessee, Knoxville, Tennessee, USA
| | - Elias J Fernandez
- Department of Biochemistry & Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, USA
| | - Todd B Reynolds
- Department of Microbiology, The University of Tennessee, Knoxville, Tennessee, USA
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Jha A, Vimal A, Bakht A, Kumar A. Inhibitors of CPH1-MAP Kinase Pathway: Ascertaining Potential Ligands as Multi-Target Drug Candidate in Candida albicans. Int J Pept Res Ther 2018. [DOI: 10.1007/s10989-018-9747-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Ali A, Jadhav A, Jangid P, Patil R, Shelar A, Karuppayil SM. The human muscarinic acetylcholine receptor antagonist, Dicyclomine targets signal transduction genes and inhibits the virulence factors in the human pathogen, Candida albicans. J Antibiot (Tokyo) 2018; 71:456-466. [PMID: 29348527 DOI: 10.1038/s41429-017-0013-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 11/20/2017] [Accepted: 11/28/2017] [Indexed: 11/09/2022]
Abstract
Dicyclomine is a human muscarinic acetylcholine receptor antagonist used for the treatment of abdominal cramps. We are reporting here that dicyclomine can inhibit the in vitro growth and virulence factors of the human pathogen Candida albicans very effectively. Dicyclomine inhibited adhesion, early biofilm, mature biofilm, and planktonic growth. Yeast to hyphal form transition of C. albicans in various inducer media such as serum, proline, glucose, and N-acetylglucosamine was inhibited. Dicyclomine also could kill C. albicans cells within 15 min of exposure. Dicyclomine appears to inhibit the yeast to hyphal conversion by affecting signal transduction pathway. The expression of selected genes associated with yeast to hyphal form transition in serum in presence of dicyclomine was studied using real-time polymerase chain reaction (RtPCR). The RtPCR analysis showed that dicyclomine targets both cAMP pathway as well as MAPK cascade. Eight genes were upregulated. Out of these, three major upregulated genes were Bcy1, Tup1, and Mig1. Dicyclomine downregulated Ume6, Ece1, and Pde2 genes which are involved in cAMP signaling pathway and also downregulated the DNA binding protein gene, Rfg1. Dicyclomine significantly upregulated the master negative regulator of hyphal formation, Tup1. Based on this study we suggest that the muscarinic acetylcholine receptor antagonist, dicyclomine could be repositioned as a potential anti-Candida albicans as well as anti-virulence agent.
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Affiliation(s)
- Awad Ali
- School of Life Sciences (DST-FIST&UGC-SAP Sponsored), SR TM University (NAAC Accredited with "A" grade), Nanded,, 431606, Maharashtra, India
| | - Ashwini Jadhav
- School of Life Sciences (DST-FIST&UGC-SAP Sponsored), SR TM University (NAAC Accredited with "A" grade), Nanded,, 431606, Maharashtra, India
| | - Priyanka Jangid
- School of Life Sciences (DST-FIST&UGC-SAP Sponsored), SR TM University (NAAC Accredited with "A" grade), Nanded,, 431606, Maharashtra, India
| | - Rajendra Patil
- School of Life Sciences (DST-FIST&UGC-SAP Sponsored), SR TM University (NAAC Accredited with "A" grade), Nanded,, 431606, Maharashtra, India
| | - Amruta Shelar
- School of Life Sciences (DST-FIST&UGC-SAP Sponsored), SR TM University (NAAC Accredited with "A" grade), Nanded,, 431606, Maharashtra, India
| | - Sankunny Mohan Karuppayil
- School of Life Sciences (DST-FIST&UGC-SAP Sponsored), SR TM University (NAAC Accredited with "A" grade), Nanded,, 431606, Maharashtra, India.
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Cullen PJ, Edgerton M. Unmasking fungal pathogens by studying MAPK-dependent cell wall regulation in Candida albicans. Virulence 2016; 7:502-5. [PMID: 27088569 DOI: 10.1080/21505594.2016.1177695] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Paul J Cullen
- a Department of Biological Sciences , State University of New York at Buffalo , Buffalo , NY , USA
| | - Mira Edgerton
- b Department of Oral Biology , State University of New York at Buffalo , Buffalo , NY , USA
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Maiti P, Ghorai P, Ghosh S, Kamthan M, Tyagi RK, Datta A. Mapping of functional domains and characterization of the transcription factor Cph1 that mediate morphogenesis in Candida albicans. Fungal Genet Biol 2015; 83:45-57. [PMID: 26291891 DOI: 10.1016/j.fgb.2015.08.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 08/09/2015] [Accepted: 08/15/2015] [Indexed: 11/26/2022]
Abstract
Cph1, a transcription factor of the Mitogen Activated Protein (MAP) kinase pathway, regulates morphogenesis in human fungal pathogen Candida albicans. Here, by following a systemic deletion approach, we have identified functional domains and motifs of Cph1 that are involved in transcription factor activity and cellular morphogenesis. We found that the N-terminal homeodomain is essential for the DNA binding activity; however, C-terminal domain and polyglutamine motif (PQ) are indispensable for the transcriptional activation function. Complementation analysis of the cph1Δ null mutant using various deletion derivatives revealed functional significance of the N- and C-terminal domains and PQ motif in filamentation process, chlamydospore formation and sensitivity to the cell wall interfering compounds. Genome-wide identification of the Cph1 binding site and quantitative RT-PCR transcript analysis in cph1Δ null mutant revealed that a number of genes which are associated with the filamentous growth, maintaining cell wall organization and mitochondrial function, and the genes of the pH response pathway are the transcriptional targets of Cph1. The data also suggest that Cph1 may function as a positive or negative regulator depending on the morphological state and physiological conditions. Moreover, differential expression of the upstream MAP kinase pathway genes in wild type and cph1Δ null mutant indicated the existence of a feedback regulation.
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Affiliation(s)
- Protiti Maiti
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India; National Institute of Plant Genome Research, New Delhi 110067, India
| | - Priyanka Ghorai
- National Institute of Plant Genome Research, New Delhi 110067, India
| | - Sumit Ghosh
- National Institute of Plant Genome Research, New Delhi 110067, India
| | - Mohan Kamthan
- National Institute of Plant Genome Research, New Delhi 110067, India
| | - Rakesh Kumar Tyagi
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India.
| | - Asis Datta
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India; National Institute of Plant Genome Research, New Delhi 110067, India.
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Xu H, Nobile CJ, Dongari-Bagtzoglou A. Glucanase induces filamentation of the fungal pathogen Candida albicans. PLoS One 2013; 8:e63736. [PMID: 23737947 PMCID: PMC3667860 DOI: 10.1371/journal.pone.0063736] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 04/05/2013] [Indexed: 11/18/2022] Open
Abstract
Candida albicans is the most common human fungal pathogen. Many organisms, including C. albicans, secrete glucanases under different environmental conditions. Here, we report a novel role for beta-1, 3- glucanase in inducing Candida albicans to form filaments at 22°C and enhancing filamentation at 37°C in nutrient-rich medium. Quorum sensing, the efg1-signaling and cek1 MAP kinase pathways are involved in this process. Our data suggest that the natural antifungal agent beta–glucanase may support morphologic transformation of Candida albicans at a wide range of ambient temperatures.
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Affiliation(s)
- Hongbin Xu
- Department of Oral Health and Diagnostic Sciences, University of Connecticut Health Center, Farmington, Connecticut, USA.
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Kabir MA, Hussain MA, Ahmad Z. Candida albicans: A Model Organism for Studying Fungal Pathogens. ISRN MICROBIOLOGY 2012; 2012:538694. [PMID: 23762753 PMCID: PMC3671685 DOI: 10.5402/2012/538694] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Accepted: 08/30/2012] [Indexed: 01/12/2023]
Abstract
Candida albicans is an opportunistic human fungal pathogen that causes candidiasis. As healthcare has been improved worldwide, the number of immunocompromised patients has been increased to a greater extent and they are highly susceptible to various pathogenic microbes and C. albicans has been prominent among the fungal pathogens. The complete genome sequence of this pathogen is now available and has been extremely useful for the identification of repertoire of genes present in this pathogen. The major challenge is now to assign the functions to these genes of which 13% are specific to C. albicans. Due to its close relationship with yeast Saccharomyces cerevisiae, an edge over other fungal pathogens because most of the technologies can be directly transferred to C. albicans from S. cerevisiae and it is amenable to mutation, gene disruption, and transformation. The last two decades have witnessed enormous amount of research activities on this pathogen that leads to the understanding of host-parasite interaction, infections, and disease propagation. Clearly, C. albicans has emerged as a model organism for studying fungal pathogens along with other two fungi Aspergillus fumigatus and Cryptococcus neoformans. Understanding its complete life style of C. albicans will undoubtedly be useful for developing potential antifungal drugs and tackling Candida infections. This will also shed light on the functioning of other fungal pathogens.
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Affiliation(s)
- M Anaul Kabir
- Molecular Genetics Laboratory, School of Biotechnology, National Institute of Technology Calicut, Calicut 673601, Kerala, India
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Chauvel M, Nesseir A, Cabral V, Znaidi S, Goyard S, Bachellier-Bassi S, Firon A, Legrand M, Diogo D, Naulleau C, Rossignol T, d’Enfert C. A versatile overexpression strategy in the pathogenic yeast Candida albicans: identification of regulators of morphogenesis and fitness. PLoS One 2012; 7:e45912. [PMID: 23049891 PMCID: PMC3457969 DOI: 10.1371/journal.pone.0045912] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 08/23/2012] [Indexed: 12/31/2022] Open
Abstract
Candida albicans is the most frequently encountered human fungal pathogen, causing both superficial infections and life-threatening systemic diseases. Functional genomic studies performed in this organism have mainly used knock-out mutants and extensive collections of overexpression mutants are still lacking. Here, we report the development of a first generation C. albicans ORFeome, the improvement of overexpression systems and the construction of two new libraries of C. albicans strains overexpressing genes for components of signaling networks, in particular protein kinases, protein phosphatases and transcription factors. As a proof of concept, we screened these collections for genes whose overexpression impacts morphogenesis or growth rates in C. albicans. Our screens identified genes previously described for their role in these biological processes, demonstrating the functionality of our strategy, as well as genes that have not been previously associated to these processes. This article emphasizes the potential of systematic overexpression strategies to improve our knowledge of regulatory networks in C. albicans. The C. albicans plasmid and strain collections described here are available at the Fungal Genetics Stock Center. Their extension to a genome-wide scale will represent important resources for the C. albicans community.
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Affiliation(s)
- Murielle Chauvel
- Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France
- INRA, USC2019, Paris, France
| | - Audrey Nesseir
- Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France
- INRA, USC2019, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Cellule Pasteur, Paris, France
| | - Vitor Cabral
- Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France
- INRA, USC2019, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Cellule Pasteur, Paris, France
| | - Sadri Znaidi
- Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France
- INRA, USC2019, Paris, France
| | - Sophie Goyard
- Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France
- INRA, USC2019, Paris, France
| | - Sophie Bachellier-Bassi
- Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France
- INRA, USC2019, Paris, France
| | - Arnaud Firon
- Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France
- INRA, USC2019, Paris, France
| | - Mélanie Legrand
- Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France
- INRA, USC2019, Paris, France
| | - Dorothée Diogo
- Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France
- INRA, USC2019, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Cellule Pasteur, Paris, France
| | - Claire Naulleau
- Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France
- INRA, USC2019, Paris, France
| | - Tristan Rossignol
- Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France
- INRA, USC2019, Paris, France
| | - Christophe d’Enfert
- Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France
- INRA, USC2019, Paris, France
- * E-mail:
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Shapiro RS, Robbins N, Cowen LE. Regulatory circuitry governing fungal development, drug resistance, and disease. Microbiol Mol Biol Rev 2011; 75:213-67. [PMID: 21646428 PMCID: PMC3122626 DOI: 10.1128/mmbr.00045-10] [Citation(s) in RCA: 384] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Pathogenic fungi have become a leading cause of human mortality due to the increasing frequency of fungal infections in immunocompromised populations and the limited armamentarium of clinically useful antifungal drugs. Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus are the leading causes of opportunistic fungal infections. In these diverse pathogenic fungi, complex signal transduction cascades are critical for sensing environmental changes and mediating appropriate cellular responses. For C. albicans, several environmental cues regulate a morphogenetic switch from yeast to filamentous growth, a reversible transition important for virulence. Many of the signaling cascades regulating morphogenesis are also required for cells to adapt and survive the cellular stresses imposed by antifungal drugs. Many of these signaling networks are conserved in C. neoformans and A. fumigatus, which undergo distinct morphogenetic programs during specific phases of their life cycles. Furthermore, the key mechanisms of fungal drug resistance, including alterations of the drug target, overexpression of drug efflux transporters, and alteration of cellular stress responses, are conserved between these species. This review focuses on the circuitry regulating fungal morphogenesis and drug resistance and the impact of these pathways on virulence. Although the three human-pathogenic fungi highlighted in this review are those most frequently encountered in the clinic, they represent a minute fraction of fungal diversity. Exploration of the conservation and divergence of core signal transduction pathways across C. albicans, C. neoformans, and A. fumigatus provides a foundation for the study of a broader diversity of pathogenic fungi and a platform for the development of new therapeutic strategies for fungal disease.
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Affiliation(s)
| | | | - Leah E. Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
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Song W, Wang H, Chen J. Candida albicans Sfl2, a temperature-induced transcriptional regulator, is required for virulence in a murine gastrointestinal infection model. FEMS Yeast Res 2011; 11:209-22. [PMID: 21205158 DOI: 10.1111/j.1567-1364.2010.00710.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Many transcriptional regulators play roles in morphogenesis of the human pathogen Candida albicans. Recently, Sfl2, a sequence homolog of C. albicans Sfl1, has been shown to be required for hyphal development. In this report, we show that, like Sfl1, Sfl2 could complement the phenotypes of the Saccharomyces cerevisiae sfl1 mutant, and green fluorescent protein-tagged Sfl2 localized in the nuclei of both yeast and hyphal cells in C. albicans, reflecting its role as a transcriptional regulator. In C. albicans, SFL2 expression was induced at a high growth temperature (37 °C) at both transcriptional and translational levels. The deletion of SFL2 impaired filamentation at a high temperature, whereas the overexpression of SFL2 promoted filamentous growth at a low temperature. Sfl2-activated hyphal development needs the existence of Efg1 and Flo8 under aerobic conditions. Thus, in contrast to Sfl1, which represses filamentation, Sfl2 acts as an activator of filamentous growth in C. albicans. Functional analysis of chimeric Sfl proteins demonstrated that the opposite actions of C. albicans Sfl1 and Sfl2 were mainly mediated by their heat shock factor domains. Furthermore, the deletion of SFL2 attenuated virulence in a mouse model of gastrointestinal colonization and dissemination, indicating that Sfl2 is important for virulence in the gastrointestinal model of candidiasis. Our results provide new insights into Sfl2 functions in C. albicans morphogenesis and pathogenesis.
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Affiliation(s)
- Wenji Song
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, SIBS, Chinese Academy of Sciences, Shanghai, China
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de Boer AD, de Groot PWJ, Weindl G, Schaller M, Riedel D, Diez-Orejas R, Klis FM, de Koster CG, Dekker HL, Gross U, Bader O, Weig M. The Candida albicans cell wall protein Rhd3/Pga29 is abundant in the yeast form and contributes to virulence. Yeast 2010; 27:611-24. [DOI: 10.1002/yea.1790] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Hogan DA, Sundstrom P. The Ras/cAMP/PKA signaling pathway and virulence in Candida albicans. Future Microbiol 2010; 4:1263-70. [PMID: 19995187 DOI: 10.2217/fmb.09.106] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Candidiasis is the most common cause of fungal infections, and the majority of these are caused by Candida albicans. The protean pathogenic potential of C. albicans includes the capacity to infect diverse mucosal and epidermal surfaces as well as to disseminate via the bloodstream to internal organs, potentially causing system failure in cases of severe immunosuppression. Many environmental niches in the host may be invaded by C. albicans through modulation of gene expression patterns while changing morphology between yeast and hyphal growth forms. The Ras/cAMP/PKA signaling pathway has attracted particular attention for its role in promoting hyphal growth and because of its importance in virulence. Here, we present an overview of the components of the pathway and their functions, how the pathway may be activated in human hosts and recent updates regarding the role of Ras/cAMP/PKA signaling in virulence.
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Affiliation(s)
- Deborah A Hogan
- Department of Microbiology & Immunology, Dartmouth Medical School, Hanover, NH 03755, USA.
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Arbour M, Epp E, Hogues H, Sellam A, Lacroix C, Rauceo J, Mitchell A, Whiteway M, Nantel A. Widespread occurrence of chromosomal aneuploidy following the routine production of Candida albicans mutants. FEMS Yeast Res 2009; 9:1070-7. [PMID: 19732157 PMCID: PMC2784216 DOI: 10.1111/j.1567-1364.2009.00563.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
It has come to our attention that approximately 35% of >100 published microarray datasets, where transcript levels were compared between two different strains, exhibit some form of chromosome-specific bias. While some of these arose from the use of strains whose aneuploidies were not known at the time, in a worrisome number of cases the recombinant strains have acquired additional aneuploidies that were not initially present in the parental strain. The aneuploidies often affected a different chromosome than the one harboring the insertion site. The affected strains originated from either CAI-4, RM1000, BWP17 or SN95 and were produced through a variety of strategies. These observations suggest that aneuploidies frequently occur during the production of recombinant strains and have an effect on global transcript profiles outside of the afflicted chromosome(s), thus raising the possibility of unintended phenotypic consequences. Thus, we propose that all Candida albicans mutants and strains should be tested for aneuploidy before being used in further studies. To this end, we describe a new rapid testing method, based on a multiplex quantitative PCR assay, that produces eight bands of distinct sizes from either the left or right arms of each C. albicans chromosome.
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Affiliation(s)
- Mélanie Arbour
- Biotechnology Research Institute, National Research Council of Canada, Montreal, QC, Canada H4P2R2
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Msb2 signaling mucin controls activation of Cek1 mitogen-activated protein kinase in Candida albicans. EUKARYOTIC CELL 2009; 8:1235-49. [PMID: 19542310 DOI: 10.1128/ec.00081-09] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have characterized the role that the Msb2 protein plays in the fungal pathogen Candida albicans by the use of mutants defective in the putative upstream components of the HOG pathway. Msb2, in cooperation with Sho1, controls the activation of the Cek1 mitogen-activated protein kinase under conditions that damage the cell wall, thus defining Msb2 as a signaling element of this pathway in the fungus. msb2 mutants display altered sensitivity to Congo red, caspofungin, zymolyase, or tunicamycin, indicating that this protein is involved in cell wall biogenesis. Msb2 (as well as Sho1 and Hst7) is involved in the transmission of the signal toward Cek1 mediated by the Cdc42 GTPase, as revealed by the use of activated alleles (Cdc42(G12V)) of this protein. msb2 mutants have a stronger defective invasion phenotype than sho1 mutants when tested on certain solid media that use mannitol or sucrose as a carbon source or under hypoxia. Interestingly, Msb2 contributes to growth under conditions of high osmolarity when both branches of the HOG pathway are altered, as triple ssk1 msb2 sho1 mutants (but not any single or double mutant) are osmosensitive. However, this phenomenon is independent of the presence of Hog1, as Hog1 phosphorylation, Hog1 translocation to the nucleus, and glycerol accumulation are not affected in this mutant following an osmotic shock. These results reveal essential functions in morphogenesis, invasion, cell wall biogenesis, and growth under conditions of high osmolarity for Msb2 in C. albicans and suggest the divergence and specialization of this signaling pathway in filamentous fungi.
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Current awareness on yeast. Yeast 2006. [DOI: 10.1002/yea.1617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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