1
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Facchini N, Wernli L, Rieken M, Bonkat G, Wirz D, Braissant O. Again and Again-Survival of Candida albicans in Urine Containing Antifungals. Pharmaceutics 2024; 16:605. [PMID: 38794267 PMCID: PMC11124869 DOI: 10.3390/pharmaceutics16050605] [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: 03/22/2024] [Revised: 04/25/2024] [Accepted: 04/26/2024] [Indexed: 05/26/2024] Open
Abstract
BACKGROUND Relapse of Candida albicans urinary tract infection (UTI) is frequent despite appropriate treatment, as commonly used antifungals such fluconazole and flucytosine are only fungistatics. To improve treatment of Candida UTI and decrease relapses, understanding the long-term metabolic activity and survival of C. albicans in urine containing antifungals at minimal inhibitory concentration (MIC) is needed. METHODS we monitored the survival, metabolic activity and consumption of glucose and proteins by C. albicans using conventional methods and isothermal microcalorimetry (IMC). We also investigated the influence of dead Candida cells on the growth of their living counterparts. RESULTS For 33 days, weak activity was observed in samples containing antifungals in which C. albicans growth rate was reduced by 48%, 60% and 88%, and the lag increased to 172 h, 168 h and 6 h for amphotericin, flucytosine and fluconazole, respectively. The metabolic activity peaks corresponded to the plate counts but were delayed compared to the exhaustion of resources. The presence of dead cells promoted growth in artificial urine, increasing growth rate and reducing lag in similar proportions. CONCLUSIONS Even with antifungal treatment, C. albicans relapses are possible. The low metabolic activity of surviving cells leading to regrowth and chlamydospore formation possibly supported by autophagy are likely important factors in relapses.
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Affiliation(s)
- Nevio Facchini
- Department of Biomedical Engineering, University of Basel, Hegenheimermattweg 167B/C, 4123 Allschwil, Switzerland; (N.F.)
- Faculty of Medicine, University of Basel, Klingelbergstrasse 61, 4056 Basel, Switzerland
| | - Lukas Wernli
- Department of Biomedical Engineering, University of Basel, Hegenheimermattweg 167B/C, 4123 Allschwil, Switzerland; (N.F.)
- Department of Urology, Kantonsspital Baselland, Rheinstrasse 26, 4410 Liestal, Switzerland
| | - Malte Rieken
- Faculty of Medicine, University of Basel, Klingelbergstrasse 61, 4056 Basel, Switzerland
- alta uro AG, Centralbahnplatz 6, 4051 Basel, Switzerland
| | - Gernot Bonkat
- Faculty of Medicine, University of Basel, Klingelbergstrasse 61, 4056 Basel, Switzerland
- alta uro AG, Centralbahnplatz 6, 4051 Basel, Switzerland
| | - Dieter Wirz
- Department of Biomedical Engineering, University of Basel, Hegenheimermattweg 167B/C, 4123 Allschwil, Switzerland; (N.F.)
| | - Olivier Braissant
- Department of Biomedical Engineering, University of Basel, Hegenheimermattweg 167B/C, 4123 Allschwil, Switzerland; (N.F.)
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2
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Du J, Dong Y, Zhao H, Peng L, Wang Y, Yu Q, Li M. Transcriptional regulation of autophagy, cell wall stress response and pathogenicity by Pho23 in C. albicans. FEBS J 2023; 290:855-871. [PMID: 36152022 DOI: 10.1111/febs.16636] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 09/02/2022] [Accepted: 09/20/2022] [Indexed: 02/04/2023]
Abstract
The modification of chromatin by histone deacetylases (HDACs) has critical roles in transcriptional regulation. In this study, we identified the Rpd3 HDAC complex component Pho23 in Candida albicans and explored its role in the transcriptional regulation of physiological processes. PHO23 deletion increased autophagic activity and upregulated the transcription of ATG genes. Moreover, the deletion of PHO23 severely impaired cell wall stress resistance and reduced the cell wall integrity (CWI) pathway in response to cell wall stress. Furthermore, the pho23Δ/Δ mutant had partial defects in hyphal development and protease secretion, which were associated with the downregulation of genes involved in hyphal development (e.g. HWP1, ALS3 and ECE1) and genes encoding secreted aspartic proteases (e.g. SAP4, SAP5, SAP6 and SAP9). In addition, the deletion of PHO23 strongly attenuated systemic infection and kidney fungal burden in mice, demonstrating that Pho23 is required for the virulence of C. albicans. Together, our results revealed that Pho23 regulates many key physiological processes in C. albicans at the transcriptional level. These data also shed light on the potential for exploiting Rpd3 HDAC complex-related proteins as antifungal targets.
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Affiliation(s)
- Jiawen Du
- Department of Microbiology, College of Life Sciences, Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | - Yixuan Dong
- Department of Microbiology, College of Life Sciences, Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | - He Zhao
- Department of Microbiology, College of Life Sciences, Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | - Liping Peng
- Department of Microbiology, College of Life Sciences, Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | - Yao Wang
- Department of Microbiology, College of Life Sciences, Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | - Qilin Yu
- Department of Microbiology, College of Life Sciences, Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | - Mingchun Li
- Department of Microbiology, College of Life Sciences, Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
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3
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Pereira de Sa N, Del Poeta M. Sterylglucosides in Fungi. J Fungi (Basel) 2022; 8:1130. [PMID: 36354897 PMCID: PMC9698648 DOI: 10.3390/jof8111130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/24/2022] [Accepted: 10/24/2022] [Indexed: 11/16/2022] Open
Abstract
Sterylglucosides (SGs) are sterol conjugates widely distributed in nature. Although their universal presence in all living organisms suggests the importance of this kind of glycolipids, they are yet poorly understood. The glycosylation of sterols confers a more hydrophilic character, modifying biophysical properties of cell membranes and altering immunogenicity of the cells. In fungi, SGs regulate different cell pathways to help overcome oxygen and pH challenges, as well as help to accomplish cell recycling and other membrane functions. At the same time, the level of these lipids is highly controlled, especially in wild-type fungi. In addition, modulating SGs metabolism is becoming a novel tool for vaccine and antifungal development. In the present review, we bring together multiple observations to emphasize the underestimated importance of SGs for fungal cell functions.
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Affiliation(s)
- Nivea Pereira de Sa
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Maurizio Del Poeta
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, NY 11794, USA
- Institute of Chemical Biology and Drug Discovery (ICB&DD), Stony Brook, NY 11794, USA
- Division of Infectious Diseases, School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
- Veterans Administration Medical Center, Northport, NY 11768, USA
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4
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Wang Y, Liu X, Xu Y, Gu Y, Zhang X, Zhang M, Wen W, Lee YW, Shi J, Mohamed SR, Goda AA, Wu H, Gao X, Gu Q. The autophagy-related proteins FvAtg4 and FvAtg8 are involved in virulence and fumonisin biosynthesis in Fusarium verticillioides. Virulence 2022; 13:764-780. [PMID: 35443859 PMCID: PMC9067522 DOI: 10.1080/21505594.2022.2066611] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Autophagy is the main intracellular degradation system by which cytoplasmic materials are transported to and degraded in the vacuole/lysosome of eukaryotic cells, and it also controls cellular differentiation and virulence in a variety of filamentous fungi. However, the contribution of the autophagic pathway to fungal development and pathogenicity in the important maize pathogen and mycotoxigenic fungus Fusarium verticillioides is still unknown. In this study, we characterized two autophagy-related proteins, FvAtg4 and FvAtg8. The F. verticillioides deletion mutants ΔFvAtg4 and ΔFvAtg8 were impaired in autophagosome formation, aerial hyphal formation, sexual growth, lipid turnover, pigmentation and fungal virulence. Interestingly, ΔFvAtg4 and ΔFvAtg8 were defective in fumonisin B1 (FB1) synthesis, which may have resulted from decreased intracellular levels of alanine in the mutants. Our results indicate that FvAtg4 and FvAtg8 contribute to F. verticillioides pathogenicity by regulating the autophagic pathway to control lipid turnover, fumonisin biosynthesis, and pigmentation during its infectious cycle.
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Affiliation(s)
- Yuejie Wang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University/Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Education, Nanjing, Jiangsu, China
| | - Xin Liu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Key Laboratory for Agro-product Safety Risk Evaluation (Nanjing), Ministry of Agriculture and Rural Affairs/Collaborative Innovation Center for Modern Grain Circulation and Safety/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu, China.,School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Yujiao Xu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University/Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Education, Nanjing, Jiangsu, China
| | - Yiying Gu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University/Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Education, Nanjing, Jiangsu, China
| | - Xinyue Zhang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University/Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Education, Nanjing, Jiangsu, China
| | - Mengxuan Zhang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University/Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Education, Nanjing, Jiangsu, China
| | - Wen Wen
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University/Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Education, Nanjing, Jiangsu, China
| | - Yin-Won Lee
- School of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Jianrong Shi
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Key Laboratory for Agro-product Safety Risk Evaluation (Nanjing), Ministry of Agriculture and Rural Affairs/Collaborative Innovation Center for Modern Grain Circulation and Safety/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu, China.,School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Sherif Ramzy Mohamed
- Food Toxicology and Contaminants Department, National Research Centre, Giza, Egypt
| | - Amira A Goda
- Food Toxicology and Contaminants Department, National Research Centre, Giza, Egypt
| | - Huijun Wu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University/Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Education, Nanjing, Jiangsu, China
| | - Xuewen Gao
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University/Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Education, Nanjing, Jiangsu, China
| | - Qin Gu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University/Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Education, Nanjing, Jiangsu, China
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5
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Peña-Oyarzún D, San Martin C, Hernández-Cáceres MP, Lavandero S, Morselli E, Budini M, Burgos PV, Criollo A. Autophagy in aging-related oral diseases. Front Endocrinol (Lausanne) 2022; 13:903836. [PMID: 35992149 PMCID: PMC9390882 DOI: 10.3389/fendo.2022.903836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 07/13/2022] [Indexed: 11/17/2022] Open
Abstract
Autophagy is an intracellular degradation mechanism that allows recycling of organelles and macromolecules. Autophagic function increases metabolite availability modulating metabolic pathways, differentiation and cell survival. The oral environment is composed of several structures, including mineralized and soft tissues, which are formed by complex interactions between epithelial and mesenchymal cells. With aging, increased prevalence of oral diseases such as periodontitis, oral cancer and periapical lesions are observed in humans. These aging-related oral diseases are chronic conditions that alter the epithelial-mesenchymal homeostasis, disrupting the oral tissue architecture affecting the quality of life of the patients. Given that autophagy levels are reduced with age, the purpose of this review is to discuss the link between autophagy and age-related oral diseases.
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Affiliation(s)
- Daniel Peña-Oyarzún
- Physiology Department, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- Interdisciplinary Center for Research in Territorial Health of the Aconcagua Valley (CIISTe Aconcagua), School of Medicine, Faculty of Medicine, San Felipe Campus, Universidad de Valparaíso, San Felipe, Chile
- Instituto de Investigación en Ciencias Odontológicas (ICOD), Facultad de Odontología, Universidad de Chile, Santiago, Chile
| | - Carla San Martin
- Interdisciplinary Center for Research in Territorial Health of the Aconcagua Valley (CIISTe Aconcagua), School of Medicine, Faculty of Medicine, San Felipe Campus, Universidad de Valparaíso, San Felipe, Chile
| | - María Paz Hernández-Cáceres
- Instituto de Investigación en Ciencias Odontológicas (ICOD), Facultad de Odontología, Universidad de Chile, Santiago, Chile
| | - Sergio Lavandero
- Advanced Center for Chronic Diseases (ACCDiS), Facultad de Ciencias Químicas y Farmacéuticas & Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
- Cardiology Division, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Eugenia Morselli
- Department of Basic Sciences, Faculty of Medicine and Sciences, Universidad San Sebastián, Santiago de Chile, Chile
- Autophagy Research Center, Universidad de Chile, Santiago de Chile, Chile
| | - Mauricio Budini
- Instituto de Investigación en Ciencias Odontológicas (ICOD), Facultad de Odontología, Universidad de Chile, Santiago, Chile
- Autophagy Research Center, Universidad de Chile, Santiago de Chile, Chile
| | - Patricia V. Burgos
- Autophagy Research Center, Universidad de Chile, Santiago de Chile, Chile
- Centro de Biología Celular y Biomedicina (CEBICEM), Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile
- Centro de Envejecimiento y Regeneración (CARE-UC), Facultad de Ciencias Biológicas, Pontificia Universidad Católica, Santiago, Chile
- Centro Ciencia & Vida, Fundación Ciencia & Vida, Santiago, Chile
| | - Alfredo Criollo
- Instituto de Investigación en Ciencias Odontológicas (ICOD), Facultad de Odontología, Universidad de Chile, Santiago, Chile
- Advanced Center for Chronic Diseases (ACCDiS), Facultad de Ciencias Químicas y Farmacéuticas & Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Autophagy Research Center, Universidad de Chile, Santiago de Chile, Chile
- *Correspondence: Alfredo Criollo,
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6
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Interactions of Both Pathogenic and Nonpathogenic CUG Clade Candida Species with Macrophages Share a Conserved Transcriptional Landscape. mBio 2021; 12:e0331721. [PMID: 34903044 PMCID: PMC8669484 DOI: 10.1128/mbio.03317-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Candida species are a leading cause of opportunistic, hospital-associated bloodstream infections with high mortality rates, typically in immunocompromised patients. Several species, including Candida albicans, the most prevalent cause of infection, belong to the monophyletic CUG clade of yeasts. Innate immune cells such as macrophages are crucial for controlling infection, and C. albicans responds to phagocytosis by a coordinated induction of pathways involved in catabolism of nonglucose carbon sources, termed alternative carbon metabolism, which together are essential for virulence. However, the interactions of other CUG clade species with macrophages have not been characterized. Here, we analyzed transcriptional responses to macrophage phagocytosis by six Candida species across a range of virulence and clinical importance. We define a core induced response common to pathogenic and nonpathogenic species alike, heavily weighted to alternative carbon metabolism. One prominent pathogen, Candida parapsilosis, showed species-specific expansion of phagocytosis-responsive genes, particularly metabolite transporters. C. albicans and Candida tropicalis, the other prominent pathogens, also had species-specific responses, but these were largely comprised of functionally uncharacterized genes. Transcriptional analysis of macrophages also demonstrated highly correlated proinflammatory transcriptional responses to different Candida species that were largely independent of fungal viability, suggesting that this response is driven by recognition of conserved cell wall components. This study significantly broadens our understanding of host interactions in CUG clade species, demonstrating that although metabolic plasticity is crucial for virulence in Candida, it alone is not sufficient to confer pathogenicity. Instead, we identify sets of mostly uncharacterized genes that may explain the evolution of pathogenicity.
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7
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Mao X, Yang L, Yu D, Ma T, Ma C, Wang J, Yu Q, Li M. The Vacuole and Mitochondria Patch (vCLAMP) Protein Vam6 is Crucial for Autophagy in Candida albicans. Mycopathologia 2021; 186:477-486. [PMID: 34057669 DOI: 10.1007/s11046-021-00565-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 05/24/2021] [Indexed: 11/24/2022]
Abstract
Vacuole and mitochondria patches (vCLAMPs) are involved in the stress resistance of yeast, but their exact role in autophagy remains so far unclear. This study, for the first time, investigated the role of the vCLAMP core protein Vam6 in autophagy of Candida albicans. The experiments demonstrated that the deletion of VAM6 led to a growth defect under nitrogen starvation. Also, western blotting revealed that the vam6Δ/Δ mutant attenuated degradation of Atg8 (an autophagy indicator), Lap41 (an indicator of the cytoplasm to vacuole targeting pathway), and Csp37 (a mitophagy indicator). Moreover, the activity of carboxypeptidase Y and the levels of the vacuolar phospholipase Atg15 were significantly decreased in the mutant, which confirmed the defect of autophagy caused by deletion of VAM6. Overall, these results revealed that Vam6 is essential in maintaining the autophagic process under nitrogen starvation, and this provided new insights into the correlation between vCLAMPs and autophagy.
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Affiliation(s)
- Xiaolong Mao
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of LifeSciences, Nankai University, No. 94, Weijin Road, Tianjin, 300071, China
| | - Li Yang
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of LifeSciences, Nankai University, No. 94, Weijin Road, Tianjin, 300071, China
| | - Dixiong Yu
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of LifeSciences, Nankai University, No. 94, Weijin Road, Tianjin, 300071, China
| | - Tianyu Ma
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of LifeSciences, Nankai University, No. 94, Weijin Road, Tianjin, 300071, China
| | - Congcong Ma
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of LifeSciences, Nankai University, No. 94, Weijin Road, Tianjin, 300071, China
| | - Jiazhen Wang
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of LifeSciences, Nankai University, No. 94, Weijin Road, Tianjin, 300071, China
| | - Qilin Yu
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of LifeSciences, Nankai University, No. 94, Weijin Road, Tianjin, 300071, China
| | - Mingchun Li
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of LifeSciences, Nankai University, No. 94, Weijin Road, Tianjin, 300071, China.
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8
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Staniszewska M. Virulence Factors in Candida species. Curr Protein Pept Sci 2021; 21:313-323. [PMID: 31544690 DOI: 10.2174/1389203720666190722152415] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 06/06/2019] [Accepted: 07/14/2019] [Indexed: 02/08/2023]
Abstract
Fungal diseases are severe and have very high morbidity as well as up to 60% mortality for patients diagnosed with invasive fungal infection. In this review, in vitro and in vivo studies provided us with the insight into the role of Candida virulence factors that mediate their success as pathogens, such as: membrane and cell wall (CW) barriers, dimorphism, biofilm formation, signal transduction pathway, proteins related to stress tolerance, hydrolytic enzymes (e.g. proteases, lipases, haemolysins), and toxin production. The review characterized the virulence of clinically important C. albicans, C. parapsilosis, C. tropicalis, C. glabrata and C. krusei. Due to the white-opaque transition in the mating-type locus MTL-homozygous cells, C. albicans demonstrates an advantage over other less related species of Candida as a human commensal and pathogen. It was reviewed that Candida ergosterol biosynthesis genes play a role in cellular stress and are essential for Candida pathogenesis both in invasive and superficial infections. Hydrolases associated with CW are involved in the host-pathogen interactions. Adhesins are crucial in colonization and biofilm formation, an important virulence factor for candidiasis. Calcineurin is involved in membrane and CW stress as well as virulence. The hyphae-specific toxin, named candidalysin, invades mucosal cells facilitating fungal invasion into deeper tissues. Expression of this protein promotes resistance to neutrophil killing in candidiasis. The virulence factors provide immunostimulatory factors, activating dendric cells and promoting T cell infiltration and activation. Targeting virulence factors, can reduce the risk of resistance development in Candida infections.
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Affiliation(s)
- Monika Staniszewska
- Faculty of Chemistry, Warsaw University of Technology, 00-664 Warsaw, Poland
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9
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Jiang ST, Chang AN, Han LT, Guo JS, Li YH, Liu TB. Autophagy Regulates Fungal Virulence and Sexual Reproduction in Cryptococcus neoformans. Front Cell Dev Biol 2020; 8:374. [PMID: 32528953 PMCID: PMC7262457 DOI: 10.3389/fcell.2020.00374] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 04/27/2020] [Indexed: 01/12/2023] Open
Abstract
Autophagy (macroautophagy) is an evolutionarily conserved degradation pathway involved in bulk degradation of cytoplasmic organelles, old protein, and other macromolecules and nutrient recycling during starvation. Extensive studies on functions of autophagy-related genes have revealed that autophagy plays a role in cell differentiation and pathogenesis of pathogenic fungi. In this study, we identified and characterized 14 core autophagy machinery genes (ATGs) in C. neoformans. To understand the function of autophagy in virulence and fungal development in C. neoformans, we knocked out the 14 ATGs in both α and a mating type strain backgrounds in C. neoformans, respectively, by using biolistic transformation and in vivo homologous recombination. Fungal virulence assay showed that virulence of each atgΔ mutants was attenuated in a murine inhalation systemic-infection model, although virulence factor production was not dramatically impaired in vitro. Fungal mating assays showed that all the 14 ATGs are essential for fungal sexual reproduction as basidiospore production was blocked in bilateral mating between each atgΔ mutants. Fungal nuclei development assay showed that nuclei in the bilateral mating of each atgΔ mutants failed to undergo meiosis after fusion, indicating autophagy is essential for regulating meiosis during mating. Overall, our study showed that autophagy is essential for fungal virulence and sexual reproduction in C. neoformans, which likely represents a conserved novel virulence and sexual reproduction control mechanism that involves the autophagy-mediated proteolysis pathway.
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Affiliation(s)
- Su-Ting Jiang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.,Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
| | - An-Ni Chang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Lian-Tao Han
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.,Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
| | - Jie-Shu Guo
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.,Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
| | - Yuan-Hong Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.,Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
| | - Tong-Bao Liu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.,Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
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10
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Zhao X, Feng W, Zhu X, Li C, Ma X, Li X, Zhu X, Wei D. Conserved Autophagy Pathway Contributes to Stress Tolerance and Virulence and Differentially Controls Autophagic Flux Upon Nutrient Starvation in Cryptococcus neoformans. Front Microbiol 2019; 10:2690. [PMID: 32038502 PMCID: PMC6988817 DOI: 10.3389/fmicb.2019.02690] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 11/06/2019] [Indexed: 12/14/2022] Open
Abstract
Autophagy is mainly a catabolic process, which is used to cope with nutrient deficiency and various stress conditions. Human environment often imposes various stresses on Cryptococcus neoformans, a major fungal pathogen of immunocompromised individuals; therefore, autophagic response of C. neoformans to these stresses often determines its survival in the host. However, a systematic study on how autophagy related (ATG) genes influence on autophagic flux, virulence, stress response and pathogenicity of C. neoformans is lacking. In this study, 22 ATG-deficient strains were constructed to investigate their roles in virulence, pathogenesis, stress response, starvation tolerance and autophagic flux in C. neoformans. Our results showed that Atg6 and Atg14-03 significantly affect the growth of C. neoformans at 37°C and laccase production. Additionally, atg2Δ and atg6Δ strains were sensitive to oxidative stress caused by hydrogen peroxide. Approximately half of the atgΔ strains displayed higher sensitivity to 1.5 M NaCl and remarkably lower virulence in the Galleria mellonella model than the wild type. Autophagic flux in C. neoformans was dependent on the Atg1-Atg13, Atg5-Atg12-Atg16, and Atg2-Atg18 complexes and Atg11. Cleavage of the green fluorescent protein (GFP) from Atg8 was difficult to detect in these autophagy defective mutants; however, it was detected in the atg3Δ, atg4Δ, atg6Δ and atg14Δ strains. Additionally, no homologs of Saccharomyces cerevisiae ATG10 were detected in C. neoformans. Our results indicate that these ATG genes contribute differentially to carbon and nitrogen starvation tolerance in C. neoformans compared with S. cerevisiae. Overall, this study advances our knowledge of the specific roles of ATG genes in C. neoformans.
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Affiliation(s)
- Xueru Zhao
- National Key Program of Microbiology and Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Weijia Feng
- National Key Program of Microbiology and Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Xiangyang Zhu
- National Key Program of Microbiology and Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Chenxi Li
- Beijing Key Laboratory of Genetic Engineering Drug and Biotechnology, Institute of Biochemistry and Molecular Biology, School of Life Sciences, Beijing Normal University, Beijing, China
| | - Xiaoyu Ma
- Beijing Key Laboratory of Genetic Engineering Drug and Biotechnology, Institute of Biochemistry and Molecular Biology, School of Life Sciences, Beijing Normal University, Beijing, China
| | - Xin Li
- National Key Program of Microbiology and Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Xudong Zhu
- Beijing Key Laboratory of Genetic Engineering Drug and Biotechnology, Institute of Biochemistry and Molecular Biology, School of Life Sciences, Beijing Normal University, Beijing, China
| | - Dongsheng Wei
- National Key Program of Microbiology and Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
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11
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Zeitz MA, Tanveer Z, Openshaw AT, Schmidt M. Genetic Regulators and Physiological Significance of Glycogen Storage in Candida albicans. J Fungi (Basel) 2019; 5:jof5040102. [PMID: 31671578 PMCID: PMC6958490 DOI: 10.3390/jof5040102] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/22/2019] [Accepted: 10/26/2019] [Indexed: 01/31/2023] Open
Abstract
The dimorphic human fungal pathogen C. albicans has broad metabolic flexibility that allows it to adapt to the nutrient conditions in different host habitats. C. albicans builds large carbohydrate stores (glycogen) at the end of exponential growth and begins consumption of stored carbohydrates when nutrients become limiting. The expression of genes required for the successful transition between host environments, including the factors controlling glycogen content, is controlled by protein kinase A signaling through the transcription factor Efg1. In addition to the inability to transition to hyphal growth, C. albicans efg1 mutants have low glycogen content and reduced long-term survival, suggesting that carbohydrate storage is required for viability during prolonged culture. To test this assumption, we constructed a glycogen-deficient C. albicans mutant and assessed its viability during extended culture. Pathways and additional genetic factors controlling C. albicans glycogen synthesis were identified through the screening of mutant libraries for strains with low glycogen content. Finally, a part of the Efg1-regulon was screened for mutants with a shortened long-term survival phenotype. We found that glycogen deficiency does not affect long-term survival, growth, metabolic flexibility or morphology of C. albicans. We conclude that glycogen is not an important contributor to C. albicans fitness.
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Affiliation(s)
- Marcus A Zeitz
- Department of Biochemistry and Nutrition, College of Osteopathic Medicine, Des Moines University, 3200 Grand Avenue, Des Moines, IA 50312, USA.
| | - Zainab Tanveer
- Department of Biochemistry and Nutrition, College of Osteopathic Medicine, Des Moines University, 3200 Grand Avenue, Des Moines, IA 50312, USA.
| | - Anatole T Openshaw
- Department of Biochemistry and Nutrition, College of Osteopathic Medicine, Des Moines University, 3200 Grand Avenue, Des Moines, IA 50312, USA.
| | - Martin Schmidt
- Department of Biochemistry and Nutrition, College of Osteopathic Medicine, Des Moines University, 3200 Grand Avenue, Des Moines, IA 50312, USA.
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12
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Xu F, Cao S, Wang C, Wang K, Wei Y, Shao X, Wang H. Antimicrobial activity of flavonoids from Sedum aizoon L. against Aeromonas in culture medium and in frozen pork. Food Sci Nutr 2019; 7:3224-3232. [PMID: 31660136 PMCID: PMC6804768 DOI: 10.1002/fsn3.1178] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 06/18/2019] [Accepted: 06/22/2019] [Indexed: 11/17/2022] Open
Abstract
The chemical composition and antimicrobial activity of flavonoids from Sedum aizoon L. against Aeromonas in vitro were investigated, and the effect of flavonoid treatment on the quality of fresh pork during frozen storage for 6 months was also explored. The results showed that kaempferol, quercetin dihydrate, and catechin were the most predominant flavonoids from S. aizoon L. Flavonoids exhibited antibacterial activity to Aeromonas in vitro, which caused membrane damage, disruption of the bacterial surface, and internal ultrastructure, and resulted in the leakage of reducing sugars and proteins. Meanwhile, flavonoid treatment retarded the microbial growth and deteriorates of pork characteristics, including pH value, total volatile basic nitrogen (TVB-N), texture, and sensory evaluation during frozen storage, thereby prolonged the shelf life. Their results suggested that flavonoids from S. aizoon L. offer a promising choice for food safety and preservation.
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Affiliation(s)
- Feng Xu
- State Key Laboratory for Quality and Safety of Agro‐products, Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical SciencesNingbo UniversityNingboChina
| | - Shifeng Cao
- College of Biological and Environmental Sciences, Key Laboratory of Fruits and Vegetables Postharvest and Processing Technology Research of Zhejiang ProvinceZhejiang Wanli UniversityNingboChina
| | - Chunxing Wang
- State Key Laboratory for Quality and Safety of Agro‐products, Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical SciencesNingbo UniversityNingboChina
| | - Kaikai Wang
- State Key Laboratory for Quality and Safety of Agro‐products, Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical SciencesNingbo UniversityNingboChina
| | - Yingying Wei
- State Key Laboratory for Quality and Safety of Agro‐products, Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical SciencesNingbo UniversityNingboChina
| | - Xingfeng Shao
- State Key Laboratory for Quality and Safety of Agro‐products, Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical SciencesNingbo UniversityNingboChina
| | - Hongfei Wang
- State Key Laboratory for Quality and Safety of Agro‐products, Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical SciencesNingbo UniversityNingboChina
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13
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Yu Q, Ma T, Ma C, Zhang B, Li M. Multifunction of the ER P-Type Calcium Pump Spf1 During Hyphal Development in Candida albicans. Mycopathologia 2019; 184:573-583. [PMID: 31473908 DOI: 10.1007/s11046-019-00372-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Accepted: 08/14/2019] [Indexed: 11/25/2022]
Abstract
Candida albicans is one of the most important fungal pathogens. Hyphal development is required for the virulence of this pathogen. Our previous study has revealed that Spf1, an ER P-type calcium pump, plays an important role in hyphal development. However, the detailed mechanisms by which this protein functions in this process remain to be investigated. In this study, we found that loss of Spf1 led to decreased growth biomass under the hypha-inducing condition, suggesting a role of this protein in maintaining hyphal growth rate. Actin staining further revealed that the spf1Δ/Δ mutant showed attenuated tip-localization of actin patches and the defect in transport of both the chitin synthase Chs3 and the hypha-related factor Hwp1, implying that Spf1 functions in polarized growth of the hyphae by regulating actin organization and consequent polarized transport of morphogenesis-associated factors. Moreover, deletion of SPF1 led to abnormal vacuolar morphology under the hypha-inducing condition, which may also contribute to the defect of hyphal development in the spf1Δ/Δ mutant. This study revealed the pleiotropic role of Spf1-regulated calcium homeostasis in controlling hyphal development in C. albicans.
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Affiliation(s)
- Qilin Yu
- Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, Ministry of Education, College of Life Science, Nankai University, Tianjin, 300071, People's Republic of China
| | - Tianyu Ma
- Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, Ministry of Education, College of Life Science, Nankai University, Tianjin, 300071, People's Republic of China
| | - Congcong Ma
- Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, Ministry of Education, College of Life Science, Nankai University, Tianjin, 300071, People's Republic of China
| | - Biao Zhang
- Tianjin University of Chinese Traditional Medicine, Tianjin, People's Republic of China
| | - Mingchun Li
- Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, Ministry of Education, College of Life Science, Nankai University, Tianjin, 300071, People's Republic of China.
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14
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Cui L, Zhao H, Yin Y, Liang C, Mao X, Liu Y, Yu Q, Li M. Function of Atg11 in non-selective autophagy and selective autophagy of Candida albicans. Biochem Biophys Res Commun 2019; 516:1152-1158. [PMID: 31284951 DOI: 10.1016/j.bbrc.2019.06.148] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 06/27/2019] [Indexed: 12/14/2022]
Abstract
Candida albicans is an important opportunistic pathogenic fungus in the human body. It is a common microbe inhabiting on the mucosa surfaces of healthy individuals, but may cause infections when the host immune system is weak. Autophagy is a "self-eating" process in eukaryotes, which can recover and utilize damaged organelles and misfolded proteins. Here we investigated the role of the autophagy-related protein Atg11 in C. albicans. Deletion of ATG11 led to the defect in growth under the nitrogen starvation condition. Western blotting and GFP localization further revealed that the transport and degradation of Atg8 was blocked in the atg11Δ/Δ mutant under both the nitrogen starvation and hypha-inducing conditions. Moreover, degradation of both Lap41 (the indicator of the cytoplasm-to-vacuole pathway) and Csp37 (the indicator of mitophagy) was also thoroughly suppressed in this mutant under nitrogen starvation. These results indicated that Atg11 plays an essential role in both non-selective and selective autophagy in C. albicans.
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Affiliation(s)
- Lifang Cui
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, China
| | - He Zhao
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, China
| | - Yujun Yin
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, China
| | - Chao Liang
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, China
| | - Xiaolong Mao
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, China
| | - Yingzheng Liu
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, China
| | - Qilin Yu
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, China
| | - Mingchun Li
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, China.
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15
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Liu ZH, Xia XJ, Zhang Y, Zhong Y, Sang B, Li QP, Wang M, Lv WW, Zhi HL, Wang XD, Guan CP, Shen H. Favus of Scrotum Due to Trichophyton rubrum in Immunocompetent Patients: A Clinical, Mycological and Ultrastructural Study. Mycopathologia 2019; 184:433-439. [PMID: 30976954 DOI: 10.1007/s11046-019-00337-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 04/06/2019] [Indexed: 11/25/2022]
Abstract
PURPOSE To characterize the clinical and mycological features of favus of scrotum due to Trichophyton rubrum. METHODS A single-site prospective study was carried out in an outpatient dermatology clinic. Microscopic examination and fungal culture were done using skin scrapings. Scales on the scrotum were stained with PAS and visualized by microscopy, including in vivo reflectance confocal microscopy (RCM). Two strains were analyzed by RAPD typing. Scutular lesions were fixed for scanning electron microscopy (SEM) and transmission electron microscopy (TEM). RESULTS Cultures of the scale from the scrotum and/or groin in all patients showed a growth of T. rubrum. T. rubrum strains from scrotum and groins in one patient were demonstrated as the same strain by RAPD typing. The average age of patients was 34.1 ± 12.78 years. The mean course was 8.2 ± 5.07 days. All the patients received only topical treatment for 2 weeks without recurrence. Direct smear, calcofluor-white staining and in vivo RCM study of the scrotal favus in patients showed a massive number of septate branching hyphae, while fewer septate hyphae in scales in the groin. Abundant hyphae were found only in the outer layer of the stratum corneum of the scrotum under SEM and TEM with intact bilateral cell walls, and normal nucleus, liposomes and reticulum. Few distorted hyphae structures, cell wall degeneration, degenerated cytoplasm and the autophagy phenomenon could be seen in scales from groin under TEM. CONCLUSIONS Scrotal favus due to T. rubrum is still a true infection, which most often occurred in immunocompetent patients.
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Affiliation(s)
- Ze-Hu Liu
- Department of Dermatology, Affiliated Third Hospital of Hangzhou, Anhui Medical University, West Lake Rd 38, Hanghzou, 310009, People's Republic of China.
| | - Xiu-Jiao Xia
- Department of Dermatology, Affiliated Third Hospital of Hangzhou, Anhui Medical University, West Lake Rd 38, Hanghzou, 310009, People's Republic of China
| | - Yong Zhang
- Department of Dermatology, Affiliated Third Hospital of Hangzhou, Anhui Medical University, West Lake Rd 38, Hanghzou, 310009, People's Republic of China
| | - Yan Zhong
- Department of Dermatology, Affiliated Third Hospital of Hangzhou, Anhui Medical University, West Lake Rd 38, Hanghzou, 310009, People's Republic of China
| | - Bo Sang
- Department of Dermatology, Affiliated Third Hospital of Hangzhou, Anhui Medical University, West Lake Rd 38, Hanghzou, 310009, People's Republic of China
| | - Qiu-Ping Li
- Department of Dermatology, Affiliated Third Hospital of Hangzhou, Anhui Medical University, West Lake Rd 38, Hanghzou, 310009, People's Republic of China
| | - Mei Wang
- Department of Dermatology, Affiliated Third Hospital of Hangzhou, Anhui Medical University, West Lake Rd 38, Hanghzou, 310009, People's Republic of China
| | - Wen-Wen Lv
- Department of Dermatology, Affiliated Third Hospital of Hangzhou, Anhui Medical University, West Lake Rd 38, Hanghzou, 310009, People's Republic of China
| | - Hui-Lin Zhi
- Department of Dermatology, Affiliated Third Hospital of Hangzhou, Anhui Medical University, West Lake Rd 38, Hanghzou, 310009, People's Republic of China
| | - Xiang-Dong Wang
- Department of Dermatology, Affiliated Third Hospital of Hangzhou, Anhui Medical University, West Lake Rd 38, Hanghzou, 310009, People's Republic of China
| | - Cui-Ping Guan
- Department of Dermatology, Affiliated Third Hospital of Hangzhou, Anhui Medical University, West Lake Rd 38, Hanghzou, 310009, People's Republic of China
| | - Hong Shen
- Department of Dermatology, Affiliated Third Hospital of Hangzhou, Anhui Medical University, West Lake Rd 38, Hanghzou, 310009, People's Republic of China
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16
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Cortez-Sánchez JL, Cortés-Acosta E, Cueto-Hernández VM, Reyes-Maldonado E, Hernández-Rodríguez C, Villa-Tanaca L, Ibarra JA. Activity and expression of Candida glabrata vacuolar proteases in autophagy-like conditions. FEMS Yeast Res 2019; 18:4828329. [PMID: 29385574 DOI: 10.1093/femsyr/foy006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 01/26/2018] [Indexed: 11/13/2022] Open
Abstract
Candida glabrata is an emerging opportunistic pathogen that has intrinsic resistance to azoles. During infection or while living as a commensal, it encounters nutritional stresses such as deficiency of carbon or nitrogen sources. Herein, we investigate the expression and activity of PrA, Ape1, Ape3 and CpY vacuolar proteases during these stressful nutrimental conditions. Our findings demonstrate a differential activity profile depending on the addition or lack of carbon, nitrogen or both. Of the four proteases tested, PrA and Ape3 showed a higher activity in the absence of nitrogen. Steady-state RNA levels for all the proteases were also differentially expressed although not always correlated with its activity, suggesting multiple levels of regulation. Microscopy observations of C. glabrata cells subjected to the different conditions showed an increase in the vacuolar volume. Moreover, the presence of ATG8-PE and an increased expression of ATG8 were observed in the yeast under the tested conditions suggesting that C. glabrata is in autophagy stage. Taken together, our results showed that PrA, Ape1, Ape3 and CpY have varying activities and expression depending on whether nitrogen or carbon is added to the media, and that these vacuolar proteases might have a role in the autophagy process.
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Affiliation(s)
- J Luis Cortez-Sánchez
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Delegación Miguel Hidalgo, Ciudad de México CP 11340, México
| | - Elías Cortés-Acosta
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Delegación Miguel Hidalgo, Ciudad de México CP 11340, México
| | - V Mónica Cueto-Hernández
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Delegación Miguel Hidalgo, Ciudad de México CP 11340, México
| | - Elba Reyes-Maldonado
- Departamento de Morfología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Delegación Miguel Hidalgo, Ciudad de México CP 11340, México
| | - César Hernández-Rodríguez
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Delegación Miguel Hidalgo, Ciudad de México CP 11340, México
| | - Lourdes Villa-Tanaca
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Delegación Miguel Hidalgo, Ciudad de México CP 11340, México
| | - J Antonio Ibarra
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Delegación Miguel Hidalgo, Ciudad de México CP 11340, México
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17
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ATG Genes Influence the Virulence of Cryptococcus neoformans through Contributions beyond Core Autophagy Functions. Infect Immun 2018; 86:IAI.00069-18. [PMID: 29986893 DOI: 10.1128/iai.00069-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 07/03/2018] [Indexed: 12/31/2022] Open
Abstract
The process of autophagy is conserved among all eukaryotes from yeast to humans and is mainly responsible for bulk degradation of cellular contents and nutrient recycling during starvation. Autophagy has been suggested to play a role in the pathogenesis of the opportunistic human fungal pathogen Cryptococcus neoformans, potentially through a contribution to the export of virulence factors. In this study, we showed that deletion of each of the ATG1, ATG7, ATG8, and ATG9 genes in C. neoformans leads to autophagy-related phenotypes, including impaired amino acid homeostasis under nitrogen starvation. In addition, the atgΔ mutants were hypersensitive to inhibition of the ubiquitin-proteasome system, a finding consistent with a role in amino acid homeostasis. Although each atgΔ mutant was not markedly impaired in virulence factor production in vitro, we found that all four ATG genes contribute to C. neoformans virulence in a murine inhalation model of cryptococcosis. Interestingly, these mutants displayed significant differences in their ability to promote disease development. A more detailed investigation of virulence for the atg1Δ and atg8Δ mutants revealed that both strains stimulated an exaggerated host immune response, which, in turn, contributed to disease severity. Overall, our results suggest that different ATG genes are involved in nonautophagic functions and contribute to C. neoformans virulence beyond their core functions in autophagy.
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18
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Zheng H, Miao P, Lin X, Li L, Wu C, Chen X, Abubakar YS, Norvienyeku J, Li G, Zhou J, Wang Z, Zheng W. Small GTPase Rab7-mediated FgAtg9 trafficking is essential for autophagy-dependent development and pathogenicity in Fusarium graminearum. PLoS Genet 2018; 14:e1007546. [PMID: 30044782 PMCID: PMC6078321 DOI: 10.1371/journal.pgen.1007546] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 08/06/2018] [Accepted: 07/06/2018] [Indexed: 12/19/2022] Open
Abstract
Fusarium graminearum is a fungal pathogen that causes Fusarium head blight (FHB) in wheat and barley. Autophagy is a highly conserved vacuolar degradation pathway essential for cellular homeostasis in which Atg9 serves as a multispanning membrane protein important for generating membranes for the formation of phagophore assembly site. However, the mechanism of autophagy or autophagosome formation in phytopathogens awaits further clarifications. In this study, we identified and characterized the Atg9 homolog (FgAtg9) in F. graminearum by live cell imaging, biochemical and genetic analyses. We find that GFP-FgAtg9 localizes to late endosomes and trans-Golgi network under both nutrient-rich and nitrogen starvation conditions and also show its dynamic actin-dependent trafficking in the cell. Further targeted gene deletion of FgATG9 demonstrates that it is important for growth, aerial hyphae development, and pathogenicity in F. graminearum. Furthermore, the deletion mutant (ΔFgatg9) shows severe defects in autophagy and lipid metabolism in response to carbon starvation. Interestingly, small GTPase FgRab7 is found to be required for the dynamic trafficking of FgAtg9, and co-immunoprecipitation (Co-IP) assays show that FgAtg9 associates with FgRab7 in vivo. Finally, heterologous complementation assay shows that Atg9 is functionally conserved in F. graminearum and Magnaporthe oryzae. Taken together, we conclude that FgAtg9 is essential for autophagy-dependent development and pathogenicity of F. graminearum, which may be regulated by the small GTPase FgRab7.
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Affiliation(s)
- Huawei Zheng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian University Key Laboratory for Plant-Microbe Interaction, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Pengfei Miao
- Fujian University Key Laboratory for Plant-Microbe Interaction, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xiaolian Lin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Lingping Li
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Congxian Wu
- Fujian University Key Laboratory for Plant-Microbe Interaction, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xiaomin Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yakubu Saddeeq Abubakar
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Justice Norvienyeku
- Fujian University Key Laboratory for Plant-Microbe Interaction, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Guangpu Li
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, United States of America
| | - Jie Zhou
- Fujian University Key Laboratory for Plant-Microbe Interaction, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Zonghua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian University Key Laboratory for Plant-Microbe Interaction, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Institute of Oceanography, Minjiang University, Fuzhou, China
| | - Wenhui Zheng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
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19
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Sprenger M, Kasper L, Hensel M, Hube B. Metabolic adaptation of intracellular bacteria and fungi to macrophages. Int J Med Microbiol 2017; 308:215-227. [PMID: 29150190 DOI: 10.1016/j.ijmm.2017.11.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 09/21/2017] [Accepted: 11/05/2017] [Indexed: 02/07/2023] Open
Abstract
The mature phagosome of macrophages is a hostile environment for the vast majority of phagocytosed microbes. In addition to active destruction of the engulfed microbes by antimicrobial compounds, restriction of essential nutrients in the phagosomal compartment contributes to microbial growth inhibition and killing. However, some pathogenic microorganisms have not only developed various strategies to efficiently withstand or counteract antimicrobial activities, but also to acquire nutrients within macrophages for intracellular replication. Successful intracellular pathogens are able to utilize host-derived amino acids, carbohydrates and lipids as well as trace metals and vitamins during intracellular growth. This requires sophisticated strategies such as phagosome modification or escape, efficient nutrient transporters and metabolic adaptation. In this review, we discuss the metabolic adaptation of facultative intracellular bacteria and fungi to the intracellular lifestyle inside macrophages.
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Affiliation(s)
- Marcel Sprenger
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knoell-Institute, Jena, Germany
| | - Lydia Kasper
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knoell-Institute, Jena, Germany
| | - Michael Hensel
- Division of Microbiology, University Osnabrück, Osnabrück, Germany
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knoell-Institute, Jena, Germany; Friedrich Schiller University, Jena, Germany; Center for Sepsis Control and Care, University Hospital, Jena, Germany.
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20
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Zhang K, Jia C, Yu Q, Xiao C, Dong Y, Zhang M, Zhang D, Zhao Q, Zhang B, Li M. Contribution of VMA5 to vacuolar function, stress response, ion homeostasis and autophagy in Candida albicans. Future Microbiol 2017; 12:1147-1166. [PMID: 28879785 DOI: 10.2217/fmb-2017-0029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
AIM V-ATPase is a conservative multi-subunit enzyme in eukaryotes and modulates several cellular responses. This study aimed to illustrate the roles of Vma5 in vacuolar function, oxidative stress response, calcium homeostasis, autophagy and virulence. MATERIALS & METHODS The vma5Δ/Δ mutant was obtained using PCR-mediated homologous recombination. The functions of Vma5 were investigated by a series of biochemical and systemic infection methods. RESULTS Disruption of VMA5 led to growth inhibition, vacuolar dysfunction, disturbance of calcium homeostasis and inhibition of calcium-related oxidative stress response. Furthermore, its deletion caused defects in autophagy completion and hyphal development, and resulted in attenuated Candida albicans virulence. CONCLUSION Our findings provide new insights into V-ATPase functions in C. albicans, and reveal a potential candidate for development of antifungal drugs.
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Affiliation(s)
- Kai Zhang
- Department of Microbiology, Key Laboratory of Molecular Microbiology & Technology, College of Life Sciences, Nankai University, Ministry of Education, Tianjin 300071, China
| | - Chang Jia
- Department of Microbiology, Key Laboratory of Molecular Microbiology & Technology, College of Life Sciences, Nankai University, Ministry of Education, Tianjin 300071, China
| | - Qilin Yu
- Department of Microbiology, Key Laboratory of Molecular Microbiology & Technology, College of Life Sciences, Nankai University, Ministry of Education, Tianjin 300071, China
| | - Chenpeng Xiao
- Department of Microbiology, Key Laboratory of Molecular Microbiology & Technology, College of Life Sciences, Nankai University, Ministry of Education, Tianjin 300071, China
| | - Yijie Dong
- Department of Microbiology, Key Laboratory of Molecular Microbiology & Technology, College of Life Sciences, Nankai University, Ministry of Education, Tianjin 300071, China.,The State Key Laboratory for Biology of Plant Disease & Insect Pests, Institute of Plant protection, Chinese Academy of Agricultural Sciences, Beijing 100871, China
| | - Meng Zhang
- Department of Microbiology, Key Laboratory of Molecular Microbiology & Technology, College of Life Sciences, Nankai University, Ministry of Education, Tianjin 300071, China
| | - Dan Zhang
- Department of Microbiology, Key Laboratory of Molecular Microbiology & Technology, College of Life Sciences, Nankai University, Ministry of Education, Tianjin 300071, China
| | - Qiang Zhao
- Department of Zoology & Developmental Biology, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Biao Zhang
- College of Language & Culture, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China
| | - Mingchun Li
- Department of Microbiology, Key Laboratory of Molecular Microbiology & Technology, College of Life Sciences, Nankai University, Ministry of Education, Tianjin 300071, China
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Gontijo FDA, de Melo AT, Pascon RC, Fernandes L, Paes HC, Alspaugh JA, Vallim MA. The role of Aspartyl aminopeptidase (Ape4) in Cryptococcus neoformans virulence and authophagy. PLoS One 2017; 12:e0177461. [PMID: 28542452 PMCID: PMC5444613 DOI: 10.1371/journal.pone.0177461] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Accepted: 04/27/2017] [Indexed: 12/19/2022] Open
Abstract
In order to survive and cause disease, microbial pathogens must be able to proliferate at the temperature of their infected host. We identified novel microbial features associated with thermotolerance in the opportunistic fungal pathogen Cryptococcus neoformans using a random insertional mutagenesis strategy, screening for mutants with defective growth at 37°C. Among several thermosensitive mutants, we identified one bearing a disruption in a gene predicted to encode the Ape4 aspartyl aminopeptidase protein. Ape4 metalloproteases in other fungi, including Saccharomyces cerevisiae, are activated by nitrogen starvation, and they are required for autophagy and the cytoplasm-to-vacuole targeting (Cvt) pathway. However, none have been previously associated with altered growth at elevated temperatures. We demonstrated that the C. neoformans ape4 mutant does not grow at 37°C, and it also has defects in the expression of important virulence factors such as phospholipase production and capsule formation. C. neoformans Ape4 activity was required for this facultative intracellular pathogen to survive within macrophages, as well as for virulence in an animal model of cryptococcal infection. Similar to S. cerevisiae Ape4, the C. neoformans GFP-Ape4 fusion protein co-localized with intracytoplasmic vesicles during nitrogen depletion. APE4 expression was also induced by the combination of nutrient and thermal stress. Together these results suggest that autophagy is an important cellular process for this microbial pathogen to survive within the environment of the infected host.
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Affiliation(s)
| | | | - Renata C. Pascon
- Universidade Federal de São Paulo, Departamento de Ciências Biológicas, Diadema, SP, Brazil
| | - Larissa Fernandes
- Universidade de Brasília, Faculdade de Ceilândia, Ceilândia, DF, Brazil
| | - Hugo Costa Paes
- Universidade de Brasília, Faculdade de Medicina, Brasília, DF, Brazil
| | - J. Andrew Alspaugh
- Duke University School of Medicine, Department of Medicine, Durham, NC, United States of America
| | - Marcelo A. Vallim
- Universidade Federal de São Paulo, Departamento de Ciências Biológicas, Diadema, SP, Brazil
- * E-mail:
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Affiliation(s)
- Pedro Miramón
- Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center, Houston, Texas, United States of America
| | - Michael C. Lorenz
- Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center, Houston, Texas, United States of America
- * E-mail:
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Endosomal Trafficking Defects Can Induce Calcium-Dependent Azole Tolerance in Candida albicans. Antimicrob Agents Chemother 2016; 60:7170-7177. [PMID: 27645241 DOI: 10.1128/aac.01034-16] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 09/11/2016] [Indexed: 01/16/2023] Open
Abstract
The azole antifungals arrest fungal growth through inhibition of ergosterol biosynthesis. We recently reported that a Candida albicans vps21Δ/Δ mutant, deficient in membrane trafficking through the late endosome/prevacuolar compartment (PVC), continues to grow in the presence of the azoles despite the depletion of cellular ergosterol. Here, we report that the vps21Δ/Δ mutant exhibits less plasma membrane damage upon azole treatment than the wild type, as measured by the release of a cytoplasmic luciferase reporter into the culture supernatant. Our results also reveal that the vps21Δ/Δ mutant has abnormal levels of intracellular Ca2+ and, in the presence of fluconazole, enhanced expression of a calcineurin-responsive RTA2-GFP reporter. Furthermore, the azole tolerance phenotype of the vps21Δ/Δ mutant is dependent upon both extracellular calcium levels and calcineurin activity. These findings underscore the importance of endosomal trafficking in determining the cellular consequences of azole treatment and indicate that this may occur through modulation of calcium- and calcineurin-dependent responses.
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Abstract
Macroautophagy/autophagy is a conserved lysosomal degradation process essential for cell physiology and human health. By regulating apoptosis, inflammation, pathogen clearance, immune response and other cellular processes, autophagy acts as a modulator of pathogenesis and is a potential therapeutic target in diverse diseases. With regard to oral disease, autophagy can be problematic either when it is activated or impaired, because this process is involved in diverse functions, depending on the specific disease and its level of progression. In particular, activated autophagy functions as a cytoprotective mechanism under environmental stress conditions, which regulates tumor growth and mediates resistance to anticancer treatment in established tumors. During infections and inflammation, activated autophagy selectively delivers microbial antigens to the immune systems, and is therefore connected to the elimination of intracellular pathogens. Impaired autophagy contributes to oxidative stress, genomic instability, chronic tissue damage, inflammation and tumorigenesis, and is involved in aberrant bacterial clearance and immune priming. Hence, substantial progress in the study of autophagy provides new insights into the pathogenesis of oral diseases. This review outlines the mechanisms of autophagy, and highlights the emerging roles of this process in oral cancer, periapical lesions, periodontal diseases, and oral candidiasis.
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Affiliation(s)
- Ya-Qin Tan
- a The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education , School and Hospital of Stomatology, Wuhan University , Wuhan , Hubei , China
| | - Jing Zhang
- a The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education , School and Hospital of Stomatology, Wuhan University , Wuhan , Hubei , China.,b Department of Oral Medicine , School and Hospital of Stomatology, Wuhan University , Wuhan , Hubei , China
| | - Gang Zhou
- a The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education , School and Hospital of Stomatology, Wuhan University , Wuhan , Hubei , China.,b Department of Oral Medicine , School and Hospital of Stomatology, Wuhan University , Wuhan , Hubei , China
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Miramón P, Lorenz MC. The SPS amino acid sensor mediates nutrient acquisition and immune evasion in Candida albicans. Cell Microbiol 2016; 18:1611-1624. [PMID: 27060451 DOI: 10.1111/cmi.12600] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 02/12/2016] [Accepted: 03/30/2016] [Indexed: 01/20/2023]
Abstract
Candida albicans is well adapted to its host and is able to sense and respond to the nutrients available within. We have shown that C. albicans avidly utilizes amino acids as a carbon source, which allows this opportunistic pathogen to neutralize acidic environments, including the macrophage phagosome. The transcription factor Stp2 is a key regulator of this phenomenon, and we sought to understand the mechanism of activation of Stp2, focusing on the SPS sensor system previously characterized for its role in nitrogen acquisition. We generated deletion mutants of the three components, SSY1, PTR3 and SSY5 and demonstrated that these strains utilize amino acids poorly as carbon source, cannot neutralize the medium in response to these nutrients, and have reduced ammonia release. Exogenous amino acids rapidly induce proteolytic processing of Stp2 and nuclear translocation in an SPS-dependent manner. A truncated version of Stp2, lacking the amino terminal nuclear exclusion domain, could suppress the growth and pH neutralization defects of the SPS mutants. We showed that the SPS system is required for normal resistance of C. albicans to macrophages and that mutants defective in this system reside in more acidic phagosomes compared with wild type cells; however, a more equivocal contribution was observed in the murine model of disseminated candidiasis. Taken together, these results indicate that the SPS system is activated under carbon starvation conditions resembling host environments, regulating Stp2 functions necessary for amino acid catabolism and normal interactions with innate immune cells.
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Affiliation(s)
- Pedro Miramón
- Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center, Houston, TX 77030, USA
| | - Michael C Lorenz
- Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center, Houston, TX 77030, USA.
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Corral-Ramos C, Roca MG, Di Pietro A, Roncero MIG, Ruiz-Roldán C. Autophagy contributes to regulation of nuclear dynamics during vegetative growth and hyphal fusion in Fusarium oxysporum. Autophagy 2015; 11:131-44. [PMID: 25560310 DOI: 10.4161/15548627.2014.994413] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
In the fungal pathogen Fusarium oxysporum, vegetative hyphal fusion triggers nuclear mitotic division in the invading hypha followed by migration of a nucleus into the receptor hypha and degradation of the resident nucleus. Here we examined the role of autophagy in fusion-induced nuclear degradation. A search of the F. oxysporum genome database for autophagy pathway components identified putative orthologs of 16 core autophagy-related (ATG) genes in yeast, including the ubiquitin-like protein Atg8, which is required for the formation of autophagosomal membranes. F. oxysporum Foatg8Δ mutants were generated in a strain harboring H1-cherry fluorescent protein (ChFP)-labeled nuclei to facilitate analysis of nuclear dynamics. The Foatg8Δ mutants did not show MDC-positive staining in contrast to the wild type and the FoATG8-complemented (cFoATG8) strain, suggesting that FoAtg8 is required for autophagy in F. oxysporum. The Foatg8Δ strains displayed reduced rates of hyphal growth, conidiation, and fusion, and were significantly attenuated in virulence on tomato plants and in the nonvertebrate animal host Galleria mellonella. In contrast to wild-type hyphae, which are almost exclusively composed of uninucleated hyphal compartments, the hyphae of the Foatg8Δ mutants contained a significant fraction of hyphal compartments with 2 or more nuclei. The increase in the number of nuclei per hyphal compartment was particularly evident after hyphal fusion events. Time-lapse microscopy analyses revealed abnormal mitotic patterns during vegetative growth in the Foatg8Δ mutants. Our results suggest that autophagy mediates nuclear degradation after hyphal fusion and has a general function in the control of nuclear distribution in F. oxysporum.
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Key Words
- Atg, autophagy-related
- BLAST, basic local alignment search tool
- CFW, calcofluor white
- ChFP, cherry fluorescent protein
- DIC, differential interference contrast
- Fusarium oxysporum
- GFP, green fluorescent protein
- HygR, hygromycin resistant
- MDC, monodansylcadaverine
- ORF, open reading frame
- PCR, polymerase chain reaction
- PDA, potato dextrose agar
- PDB, potato dextrose broth
- PMSF, phenylmethylsulfonyl fluoride
- SM, synthetic medium
- WT, wild-type
- autophagy
- filamentous fungi
- gDNA, genomic DNA
- hyphal fusion
- nuclear dynamics
- virulence
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Affiliation(s)
- Cristina Corral-Ramos
- a Departamento de Genética; Universidad de Córdoba; Campus de Excelencia Agroalimentario ; Córdoba , Spain
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Dong Y, Yu Q, Chen Y, Xu N, Zhao Q, Jia C, Zhang B, Zhang K, Zhang B, Xing L, Li M. The Ccz1 mediates the autophagic clearance of damaged mitochondria in response to oxidative stress in Candida albicans. Int J Biochem Cell Biol 2015; 69:41-51. [PMID: 26471407 DOI: 10.1016/j.biocel.2015.10.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 08/28/2015] [Accepted: 10/07/2015] [Indexed: 10/25/2022]
Abstract
Autophagy plays a critical role in response to numerous cellular stresses, such as nutrient deprivation, hypoxia, starvation and organelle damage. The disruption of autophagy pathway affects multiple aspects of cellular stress response. Here we for the first time identified Ccz1 as an essential component for autophagy in Candida albicans. Our experiments demonstrated that loss of CCZ1 gene led to vacuolar fragmentation and disruption of the autophagy pathway. Our results also suggested that Ccz1 functioned in oxidative stress. In the ccz1Δ/Δ mutant, the levels of reactive oxidative species (ROS) sharply increased under H2O2 treatment. Further studies demonstrated that breakdown of the autophagic clearance pathway led to the accumulation of oxidative stress-damaged mitochondria, and consequently elevated cellular ROS levels in the ccz1Δ/Δ mutant. Furthermore, deletion of CCZ1 led to a significant defect in filamentous development at both 30°C and 37°C. The disruption of CCZ1 gene led to decreased capacity of macrophage killing and increased sensitivity to the macrophages. In addition, the ccz1Δ/Δ mutant exhibited attenuated virulence and decreased fungal burdens in the mouse systemic infection model, indicating that CCZ1 might provide a promising target for antifungal drugs development. In summary, our findings provide new insights into the understanding of autophagy-related gene in C. albicans.
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Affiliation(s)
- Yijie Dong
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, PR China.
| | - Qilin Yu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, PR China.
| | - Yulu Chen
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, PR China.
| | - Ning Xu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, PR China.
| | - Qiang Zhao
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, PR China.
| | - Chang Jia
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, PR China.
| | - Bing Zhang
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, PR China.
| | - Kai Zhang
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, PR China.
| | - Biao Zhang
- Tianjin University of Traditional Chinese Medicine, Tianjin, PR China.
| | - Laijun Xing
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, PR China.
| | - Mingchun Li
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, PR China.
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Sepúlveda-González ME, Parra-Ortega B, Betancourt-Cervantes Y, Hernández-Rodríguez C, Xicohtencatl-Cortes J, Villa-Tanaca L. Vacuolar proteases from Candida glabrata: Acid aspartic protease PrA, neutral serine protease PrB and serine carboxypeptidase CpY. The nitrogen source influences their level of expression. Rev Iberoam Micol 2015; 33:26-33. [PMID: 26422323 DOI: 10.1016/j.riam.2014.10.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 08/25/2014] [Accepted: 10/17/2014] [Indexed: 10/23/2022] Open
Abstract
BACKGROUND The Saccharomyces cerevisiae vacuole is actively involved in the mechanism of autophagy and is important in homeostasis, degradation, turnover, detoxification and protection under stressful conditions. In contrast, vacuolar proteases have not been fully studied in phylogenetically related Candida glabrata. AIMS The present paper is the first report on proteolytic activity in the C. glabrata vacuole. METHODS Biochemical studies in C. glabrata have highlighted the presence of different kinds of intracellular proteolytic activity: acid aspartyl proteinase (PrA) acts on substrates such as albumin and denatured acid hemoglobin, neutral serine protease (PrB) on collagen-type hide powder azure, and serine carboxypeptidase (CpY) on N-benzoyl-tyr-pNA. RESULTS Our results showed a subcellular fraction with highly specific enzymatic activity for these three proteases, which allowed to confirm its vacuolar location. Expression analyses were performed in the genes CgPEP4 (CgAPR1), CgPRB1 and CgCPY1 (CgPRC), coding for vacuolar aspartic protease A, neutral protease B and carboxypeptidase Y, respectively. The results show a differential regulation of protease expression depending on the nitrogen source. CONCLUSIONS The proteases encoded by genes CgPEP4, CgPRB1 and CgCPY1 from C. glabrata could participate in the process of autophagy and survival of this opportunistic pathogen.
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Affiliation(s)
- M Eugenia Sepúlveda-González
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional, Delegación Miguel Hidalgo, México, D.F., Mexico; Laboratorio de Investigación en Bacteriología Intestinal, Unidad de Hemato-Oncología e Investigación, Hospital Infantil de México Federico Gómez, Delegación Cuauhtémoc, México, D.F., Mexico
| | - Berenice Parra-Ortega
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional, Delegación Miguel Hidalgo, México, D.F., Mexico
| | - Yuliana Betancourt-Cervantes
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional, Delegación Miguel Hidalgo, México, D.F., Mexico
| | - César Hernández-Rodríguez
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional, Delegación Miguel Hidalgo, México, D.F., Mexico
| | - Juan Xicohtencatl-Cortes
- Laboratorio de Investigación en Bacteriología Intestinal, Unidad de Hemato-Oncología e Investigación, Hospital Infantil de México Federico Gómez, Delegación Cuauhtémoc, México, D.F., Mexico.
| | - Lourdes Villa-Tanaca
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional, Delegación Miguel Hidalgo, México, D.F., Mexico.
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29
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Yu Q, Jia C, Dong Y, Zhang B, Xiao C, Chen Y, Wang Y, Li X, Wang L, Zhang B, Li M. Candida albicans autophagy, no longer a bystander: Its role in tolerance to ER stress-related antifungal drugs. Fungal Genet Biol 2015; 81:238-49. [DOI: 10.1016/j.fgb.2015.02.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Revised: 02/12/2015] [Accepted: 02/15/2015] [Indexed: 10/24/2022]
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30
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Antibacterial mechanism and activities of black pepper chloroform extract. Journal of Food Science and Technology 2015; 52:8196-203. [PMID: 26604394 DOI: 10.1007/s13197-015-1914-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 05/28/2015] [Accepted: 06/05/2015] [Indexed: 10/23/2022]
Abstract
Black pepper extracts reportedly inhibit food spoilage and food pathogenic bacteria. This study explored the antimicrobial activity of black pepper chloroform extract (BPCE) against Escherichia coli and Staphylococcus aureus. The antibacterial mechanism of BPCE was elucidated by analyzing the cell morphology, respiratory metabolism, pyruvic acid content, and ATP levels of the target bacteria. Scanning electron micrographs showed that the bacterial cells were destroyed and that plasmolysis was induced. BPCE inhibited the tricarboxylic acid pathway of the bacteria. The extract significantly increased pyruvic acid concentration in bacterial solutions and reduced ATP level in bacterial cells. BPCE destroyed the permeability of the cell membrane, which consequently caused metabolic dysfunction, inhibited energy synthesis, and triggered cell death.
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31
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Trafficking through the late endosome significantly impacts Candida albicans tolerance of the azole antifungals. Antimicrob Agents Chemother 2015; 59:2410-20. [PMID: 25666149 DOI: 10.1128/aac.04239-14] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The azole antifungals block ergosterol biosynthesis by inhibiting lanosterol demethylase (Erg11p). The resulting depletion of cellular ergosterol and the accumulation of "toxic" sterol intermediates are both thought to compromise plasma membrane function. However, the effects of ergosterol depletion upon the function of intracellular membranes and organelles are not well described. The purpose of this study was to characterize the effects of azole treatment upon the integrity of the Candida albicans vacuole and to determine whether, in turn, vacuolar trafficking influences azole susceptibility. Profound fragmentation of the C. albicans vacuole can be observed as an early consequence of azole treatment, and it precedes significant growth inhibition. In addition, a C. albicans vps21Δ/Δ mutant, blocked in membrane trafficking through the late endosomal prevacuolar compartment (PVC), is able to grow significantly more than the wild type in the presence of several azole antifungals under standard susceptibility testing conditions. Furthermore, the vps21Δ/Δ mutant is able to grow despite the depletion of cellular ergosterol. This phenotype resembles an exaggerated form of "trailing growth" that has been described for some clinical isolates. In contrast, the vps21Δ/Δ mutant is hypersensitive to drugs that block alternate steps in ergosterol biosynthesis. On the basis of these results, we propose that endosomal trafficking defects may lead to the cellular "redistribution" of the sterol intermediates that accumulate following inhibition of ergosterol biosynthesis. Furthermore, the destination of these intermediates, or the precise cellular compartments in which they accumulate, may be an important determinant of their toxicity and thus ultimately antifungal efficacy.
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32
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Yu Q, Zhang B, Yang B, Chen J, Wang H, Jia C, Ding X, Xu N, Dong Y, Zhang B, Xing L, Li M. Interaction among the vacuole, the mitochondria, and the oxidative stress response is governed by the transient receptor potential channel in Candida albicans. Free Radic Biol Med 2014; 77:152-67. [PMID: 25308698 DOI: 10.1016/j.freeradbiomed.2014.09.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Revised: 09/01/2014] [Accepted: 09/04/2014] [Indexed: 12/22/2022]
Abstract
Candida albicans is one of the most important opportunistic pathogens, causing both mucosal candidiasis and life-threatening systemic infections. To survive in the host immune defense system, this pathogen uses an elaborate signaling network to recognize and respond to oxidative stress, which is essential for its pathogenicity. However, the exact mechanisms that this fungus employs to integrate the oxidative stress response (OSR) with functions of various organelles remain uncharacterized. Our previous work implicated a connection between the calcium signaling system and the OSR. In this study, we find that the vacuolar transient receptor potential (TRP) channel Yvc1, one of the calcium signaling members, plays a critical role in cell tolerance to oxidative stress. We further provide evidence that this channel is required not only for activation of Cap1-related transcription of OSR genes but also for maintaining the stability of both the mitochondria and the vacuole in a potassium- and calcium-dependent manner. Element assays reveal that this TRP channel affects calcium influx and potassium transport from the vacuole to the mitochondria. Therefore, the TRP channel governs the novel interaction among the OSR, the vacuole, and the mitochondria by mediating ion transport in this pathogen under oxidative stress.
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Affiliation(s)
- Qilin Yu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin 300071, People's Republic of China
| | - Bing Zhang
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin 300071, People's Republic of China
| | - Baopeng Yang
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin 300071, People's Republic of China
| | - Jiatong Chen
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin 300071, People's Republic of China
| | - Hui Wang
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin 300071, People's Republic of China; Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, China
| | - Chang Jia
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin 300071, People's Republic of China
| | - Xiaohui Ding
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin 300071, People's Republic of China
| | - Ning Xu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin 300071, People's Republic of China
| | - Yijie Dong
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin 300071, People's Republic of China
| | - Biao Zhang
- Tianjin Traditional Chinese Medicine University, Tianjin 300193, People's Republic of China
| | - Laijun Xing
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin 300071, People's Republic of China
| | - Mingchun Li
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin 300071, People's Republic of China.
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33
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Rai MN, Sharma V, Balusu S, Kaur R. An essential role for phosphatidylinositol 3-kinase in the inhibition of phagosomal maturation, intracellular survival and virulence inCandida glabrata. Cell Microbiol 2014; 17:269-87. [DOI: 10.1111/cmi.12364] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 08/29/2014] [Accepted: 09/10/2014] [Indexed: 02/03/2023]
Affiliation(s)
- Maruti Nandan Rai
- Laboratory of Fungal Pathogenesis; Centre for DNA Fingerprinting and Diagnostics; Hyderabad Telangana India
| | - Vandana Sharma
- Laboratory of Fungal Pathogenesis; Centre for DNA Fingerprinting and Diagnostics; Hyderabad Telangana India
| | - Sriram Balusu
- Laboratory of Fungal Pathogenesis; Centre for DNA Fingerprinting and Diagnostics; Hyderabad Telangana India
| | - Rupinder Kaur
- Laboratory of Fungal Pathogenesis; Centre for DNA Fingerprinting and Diagnostics; Hyderabad Telangana India
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Abstract
Fungal pathogens must assimilate local nutrients to establish an infection in their mammalian host. We focus on carbon, nitrogen, and micronutrient assimilation mechanisms, discussing how these influence host-fungus interactions during infection. We highlight several emerging trends based on the available data. First, the perturbation of carbon, nitrogen, or micronutrient assimilation attenuates fungal pathogenicity. Second, the contrasting evolutionary pressures exerted on facultative versus obligatory pathogens have led to contemporary pathogenic fungal species that display differing degrees of metabolic flexibility. The evolutionarily ancient metabolic pathways are conserved in most fungal pathogen, but interesting gaps exist in some species (e.g., Candida glabrata). Third, metabolic flexibility is generally essential for fungal pathogenicity, and in particular, for the adaptation to contrasting host microenvironments such as the gastrointestinal tract, mucosal surfaces, bloodstream, and internal organs. Fourth, this metabolic flexibility relies on complex regulatory networks, some of which are conserved across lineages, whereas others have undergone significant evolutionary rewiring. Fifth, metabolic adaptation affects fungal susceptibility to antifungal drugs and also presents exciting opportunities for the development of novel therapies.
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Affiliation(s)
- Iuliana V Ene
- Aberdeen Fungal Group, School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, United Kingdom
| | - Sascha Brunke
- Department of Microbial Pathogenicity Mechanisms, Hans Knoell Institute, 07745 Jena, Germany
| | - Alistair J P Brown
- Aberdeen Fungal Group, School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, United Kingdom
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Hans Knoell Institute, 07745 Jena, Germany Friedrich Schiller University, 07743 Jena, Germany Center for Sepsis Control and Care, Universitätsklinikum Jena, 07747 Jena, Germany
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35
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The contribution of Candida albicans vacuolar ATPase subunit V₁B, encoded by VMA2, to stress response, autophagy, and virulence is independent of environmental pH. EUKARYOTIC CELL 2014; 13:1207-21. [PMID: 25038082 DOI: 10.1128/ec.00135-14] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Candida albicans vacuoles are central to many critical biological processes, including filamentation and in vivo virulence. The V-ATPase proton pump is a multisubunit complex responsible for organellar acidification and is essential for vacuolar biogenesis and function. To study the function of the V₁B subunit of C. albicans V-ATPase, we constructed a tetracycline-regulatable VMA2 mutant, tetR-VMA2. Inhibition of VMA2 expression resulted in the inability to grow at alkaline pH and altered resistance to calcium, cold temperature, antifungal drugs, and growth on nonfermentable carbon sources. Furthermore, V-ATPase was unable to fully assemble at the vacuolar membrane and was impaired in proton transport and ATPase-specific activity. VMA2 repression led to vacuolar alkalinization in addition to abnormal vacuolar morphology and biogenesis. Key virulence-related traits, including filamentation and secretion of degradative enzymes, were markedly inhibited. These results are consistent with previous studies of C. albicans V-ATPase; however, differential contributions of the V-ATPase Vo and V₁ subunits to filamentation and secretion are observed. We also make the novel observation that inhibition of C. albicans V-ATPase results in increased susceptibility to osmotic stress. Notably, V-ATPase inhibition under conditions of nitrogen starvation results in defects in autophagy. Lastly, we show the first evidence that V-ATPase contributes to virulence in an acidic in vivo system by demonstrating that the tetR-VMA2 mutant is avirulent in a Caenorhabditis elegans infection model. This study illustrates the fundamental requirement of V-ATPase for numerous key virulence-related traits in C. albicans and demonstrates that the contribution of V-ATPase to virulence is independent of host pH.
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Bauerová V, Hájek M, Pichová I, Hrušková-Heidingsfeldová O. Intracellular aspartic proteinase Apr1p of Candida albicans is required for morphological transition under nitrogen-limited conditions but not for macrophage killing. Folia Microbiol (Praha) 2014; 59:485-93. [DOI: 10.1007/s12223-014-0324-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 05/13/2014] [Indexed: 02/04/2023]
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Ramachandra S, Linde J, Brock M, Guthke R, Hube B, Brunke S. Regulatory networks controlling nitrogen sensing and uptake in Candida albicans. PLoS One 2014; 9:e92734. [PMID: 24651113 PMCID: PMC3961412 DOI: 10.1371/journal.pone.0092734] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 02/24/2014] [Indexed: 12/22/2022] Open
Abstract
Nitrogen is one of the key nutrients for microbial growth. During infection, pathogenic fungi like C. albicans need to acquire nitrogen from a broad range of different and changing sources inside the host. Detecting the available nitrogen sources and adjusting the expression of genes for their uptake and degradation is therefore crucial for survival and growth as well as for establishing an infection. Here, we analyzed the transcriptional response of C. albicans to nitrogen starvation and feeding with the infection-relevant nitrogen sources arginine and bovine serum albumin (BSA), representing amino acids and proteins, respectively. The response to nitrogen starvation was marked by an immediate repression of protein synthesis and an up-regulation of general amino acid permeases, as well as an up-regulation of autophagal processes in its later stages. Feeding with arginine led to a fast reduction in expression of general permeases for amino acids and to resumption of protein synthesis. The response to BSA feeding was generally slower, and was additionally characterized by an up-regulation of oligopeptide transporter genes. From time-series data, we inferred network interaction models for genes relevant in nitrogen detection and uptake. Each individual network was found to be largely specific for the experimental condition (starvation or feeding with arginine or BSA). In addition, we detected several novel connections between regulator and effector genes, with putative roles in nitrogen uptake. We conclude that C. albicans adopts a particular nitrogen response network, defined by sets of specific gene-gene connections for each environmental condition. All together, they form a grid of possible gene regulatory networks, increasing the transcriptional flexibility of C. albicans.
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Affiliation(s)
- Shruthi Ramachandra
- Department of Microbial Biochemistry and Physiology, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute, Jena, Germany
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute, Jena, Germany
| | - Jörg Linde
- Department of Systems Biology & Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute, Jena, Germany
| | - Matthias Brock
- Department of Microbial Biochemistry and Physiology, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute, Jena, Germany
- Friedrich Schiller University, Jena, Germany
| | - Reinhard Guthke
- Department of Systems Biology & Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute, Jena, Germany
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute, Jena, Germany
- Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
- Friedrich Schiller University, Jena, Germany
| | - Sascha Brunke
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute, Jena, Germany
- Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
- * E-mail:
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A novel role of the vacuolar calcium channel Yvc1 in stress response, morphogenesis and pathogenicity of Candida albicans. Int J Med Microbiol 2013; 304:339-50. [PMID: 24368068 DOI: 10.1016/j.ijmm.2013.11.022] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2013] [Revised: 11/13/2013] [Accepted: 11/30/2013] [Indexed: 11/23/2022] Open
Abstract
C. albicans is a common opportunistic pathogen, causing both superficial and life-threatening systemic infections. Calcium signaling is an intriguing aspect in its physiology, attributing to the roles in stress response and morphogenesis. Until recently, little was known about the mechanisms by which the calcium signaling-associated elements affect its pathogenicity. In this study, we found that Yvc1, a member of the transient receptor potential (TRP) family, localized on the vacuolar membrane. The yvc1Δ/Δ mutant displayed decreased ability of stress response, morphogenesis and attenuated virulence. The Spitzenkörper required for polarized growth were not detected in the hyphal tip of this mutant, suggesting a key role of Yvc1 in hyphal polarized growth and re-orientation to host signals. This study demonstrates, for the first time, that the putative vacuolar calcium channel Yvc1 plays an important role in C. albicans infection and survival in host tissues, which is associated with its pleiotropic effects in several fungal physiological processes, including stress response, morphogenesis, and polarized growth.
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Thriving within the host: Candida spp. interactions with phagocytic cells. Med Microbiol Immunol 2013; 202:183-95. [DOI: 10.1007/s00430-013-0288-z] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Accepted: 01/10/2013] [Indexed: 01/04/2023]
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Brunke S, Hube B. Two unlike cousins: Candida albicans and C. glabrata infection strategies. Cell Microbiol 2013; 15:701-8. [PMID: 23253282 PMCID: PMC3654559 DOI: 10.1111/cmi.12091] [Citation(s) in RCA: 162] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 10/25/2012] [Accepted: 10/29/2012] [Indexed: 12/28/2022]
Abstract
Candida albicans and C. glabrata are the two most common pathogenic yeasts of humans, yet they are phylogenetically, genetically and phenotypically very different. In this review, we compare and contrast the strategies of C. albicans and C. glabrata to attach to and invade into the host, obtain nutrients and evade the host immune response. Although their strategies share some basic concepts, they differ greatly in their outcome. While C. albicans follows an aggressive strategy to subvert the host response and to obtain nutrients for its survival, C. glabrata seems to have evolved a strategy which is based on stealth, evasion and persistence, without causing severe damage in murine models. However, both fungi are successful as commensals and as pathogens of humans. Understanding these strategies will help in finding novel ways to fight Candida, and fungal infections in general.
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Affiliation(s)
- Sascha Brunke
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knoell Institute Jena (HKI), Beutenbergstrasse 11a, 07745 Jena, Germany
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Liu XH, Gao HM, Xu F, Lu JP, Devenish RJ, Lin FC. Autophagy vitalizes the pathogenicity of pathogenic fungi. Autophagy 2012; 8:1415-25. [PMID: 22935638 DOI: 10.4161/auto.21274] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Plant pathogenic fungi utilize a series of complex infection structures, in particular the appressorium, to gain entry to and colonize plant tissue. As a consequence of the accumulation of huge quantities of glycerol in the cell the appressorium generates immense intracellular turgor pressure allowing the penetration peg of the appressorium to penetrate the leaf cuticle. Autophagic processes are ubiquitous in eukaryotic cells and facilitate the bulk degradation of macromolecules and organelles. The study of autophagic processes has been extended from the model yeast Saccharomyces cerevisiae to pathogenic fungi such as the rice blast fungus Magnaporthe oryzae. Significantly, null mutants for the expression of M. oryzae autophagy gene homologs lose their pathogenicity for infection of host plants. Clarification of the functions and network of interactions between the proteins expressed by M. oryzae autophagy genes will lead to a better understanding of the role of autophagy in fungal pathogenesis and help in the development of new strategies for disease control.
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Affiliation(s)
- Xiao-Hong Liu
- State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou, China
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Klionsky DJ. Look people, "Atg" is an abbreviation for "autophagy-related." That's it. Autophagy 2012; 8:1281-2. [PMID: 22889836 DOI: 10.4161/auto.21812] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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Song Q, Kumar A. An Overview of Autophagy and Yeast Pseudohyphal Growth: Integration of Signaling Pathways during Nitrogen Stress. Cells 2012; 1:263-83. [PMID: 24710476 PMCID: PMC3901118 DOI: 10.3390/cells1030263] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 06/14/2012] [Accepted: 06/19/2012] [Indexed: 11/24/2022] Open
Abstract
The budding yeast Saccharomyces cerevisiae responds to nutritional stress through the regulated activities of signaling pathways mediating autophagy and other conserved cellular processes. Autophagy has been studied intensely in yeast, where over 30 autophagy-related genes have been identified with defined roles enabling the formation of autophagic vesicles and their subsequent trafficking to the central yeast vacuole. Much less, however, is known regarding the regulatory mechanisms through which autophagy is integrated with other yeast stress responses. Nitrogen limitation initiates autophagy and pseudohyphal growth in yeast, the latter being a fascinating stress response characterized by the formation of multicellular chains or filaments of elongated cells. An increasing body of evidence suggests an interrelationship between processes responsive to nitrogen stress with cAMP-dependent PKA and the TOR kinase complex acting as key regulators of autophagy, pseudohyphal growth, and endocytosis. In this review, we will summarize our current understanding of the regulatory events controlling these processes. In particular, we explore the interplay between autophagy, polarized pseudohyphal growth, and to a lesser extent endocytosis, and posit that the integrated response of these processes in yeast is a critical point for further laboratory experimentation as a model of cellular responses to nitrogen limitation throughout the Eukaryota.
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Affiliation(s)
- Qingxuan Song
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Anuj Kumar
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA.
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Macrophage autophagy in immunity to Cryptococcus neoformans and Candida albicans. Infect Immun 2012; 80:3065-76. [PMID: 22710871 DOI: 10.1128/iai.00358-12] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Autophagy is used by eukaryotes in bulk cellular material recycling and in immunity to intracellular pathogens. We evaluated the role of macrophage autophagy in the response to Cryptococcus neoformans and Candida albicans, two important opportunistic fungal pathogens. The autophagosome marker LC3 (microtubule-associated protein 1 light chain 3 alpha) was present in most macrophage vacuoles containing C. albicans. In contrast, LC3 was found in only a few vacuoles containing C. neoformans previously opsonized with antibody but never after complement-mediated phagocytosis. Disruption of host autophagy in vitro by RNA interference against ATG5 (autophagy-related 5) decreased the phagocytosis of C. albicans and the fungistatic activity of J774.16 macrophage-like cells against both fungi, independent of the opsonin used. ATG5-knockout bone marrow-derived macrophages (BMMs) also had decreased fungistatic activity against C. neoformans when activated. In contrast, nonactivated ATG5-knockout BMMs actually restricted C. neoformans growth more efficiently, suggesting that macrophage autophagy plays different roles against C. neoformans, depending on the macrophage type and activation. Interference with autophagy in J774.16 cells also decreased nonlytic exocytosis of C. neoformans, increased interleukin-6 secretion, and decreased gamma interferon-induced protein 10 secretion. Mice with a conditionally knocked out ATG5 gene in myeloid cells showed increased susceptibility to intravenous C. albicans infection. In contrast, these mice manifested no increased susceptibility to C. neoformans, as measured by survival, but had fewer alternatively activated macrophages and less inflammation in the lungs after intratracheal infection than control mice. These results demonstrate the complex roles of macrophage autophagy in restricting intracellular parasitism by fungi and reveal connections with nonlytic exocytosis, humoral immunity, and cytokine signaling.
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45
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Multifunction of autophagy-related genes in filamentous fungi. Microbiol Res 2012; 167:339-45. [DOI: 10.1016/j.micres.2012.01.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 01/11/2012] [Accepted: 01/16/2012] [Indexed: 12/19/2022]
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46
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Zelante T, Iannitti RG, De Luca A, Arroyo J, Blanco N, Servillo G, Sanglard D, Reichard U, Palmer GE, Latgè JP, Puccetti P, Romani L. Sensing of mammalian IL-17A regulates fungal adaptation and virulence. Nat Commun 2012; 3:683. [PMID: 22353714 DOI: 10.1038/ncomms1685] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 01/13/2012] [Indexed: 12/19/2022] Open
Abstract
Infections by opportunistic fungi have traditionally been viewed as the gross result of a pathogenic automatism, which makes a weakened host more vulnerable to microbial insults. However, fungal sensing of a host's immune environment might render this process more elaborate than previously appreciated. Here we show that interleukin (IL)-17A binds fungal cells, thus tackling both sides of the host-pathogen interaction in experimental settings of host colonization and/or chronic infection. Global transcriptional profiling reveals that IL-17A induces artificial nutrient starvation conditions in Candida albicans, resulting in a downregulation of the target of rapamycin signalling pathway and in an increase in autophagic responses and intracellular cAMP. The augmented adhesion and filamentous growth, also observed with Aspergillus fumigatus, eventually translates into enhanced biofilm formation and resistance to local antifungal defenses. This might exemplify a mechanism whereby fungi have evolved a means of sensing host immunity to ensure their own persistence in an immunologically dynamic environment.
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Affiliation(s)
- Teresa Zelante
- Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia 06122, Italy
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Palmer GE. Vacuolar trafficking and Candida albicans pathogenesis. Commun Integr Biol 2011; 4:240-2. [PMID: 21655451 DOI: 10.4161/cib.4.2.14717] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Accepted: 01/04/2011] [Indexed: 11/19/2022] Open
Abstract
The vacuole is likely to play a variety of roles in supporting host colonization and infection by pathogenic species of fungi. In the human pathogen Candida albicans, the vacuole undergoes dynamic morphological shifts during the production of the tissue invasive hyphal form, and this organelle is required for virulence. Recent efforts in my lab have focused on defining which vacuolar trafficking pathways are required for C. albicans hyphal growth and pathogenesis. Our results indicate that there are several distinct trafficking routes between the Golgi apparatus and vacuole. However, there is a large degree of functional overlap between each with respect to their roles in hyphal growth and virulence. Herein we consider these results and propose that during hyphal growth, specific trafficking routes maybe less important than the aggregate vacuolar trafficking capacity.
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Affiliation(s)
- Glen E Palmer
- Department of Oral and Craniofacial Biology; LSUHSC School of Dentistry; New Orleans, LA USA
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48
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Chen SCA, Lewis RE, Kontoyiannis DP. Direct effects of non-antifungal agents used in cancer chemotherapy and organ transplantation on the development and virulence of Candida and Aspergillus species. Virulence 2011; 2:280-95. [PMID: 21701255 PMCID: PMC3173675 DOI: 10.4161/viru.2.4.16764] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Revised: 06/01/2011] [Accepted: 06/03/2011] [Indexed: 11/19/2022] Open
Abstract
Conventional antineoplastic, novel immunosuppressive agents and antibiotics used in cancer treatment can directly affect the growth, development and virulence of Candida and Aspergillus species. Cytotoxic and cisplatin compounds have anti-Candida activity and may be synergistic with antifungal drugs; they also inhibit Candida and Aspergillus filamentation/conidation and effect increased virulence in vitro. Glucocorticoids enhance Candida adherence to epithelial cells, germination in serum and in vitro secretion of phospholipases and proteases, as well as growth of A. fumigatus. Calcineurin and target of rapamycin inhibitors perturb Candida and Aspergillus morphogenesis, stress responses and survival in serum, reduce azole tolerance in Candida, but yield conflicting in vivo data. Inhibition of candidal heat shock protein 90 and candidal-specific histone deacetylase represent feasible therapeutic approaches for candidiasis. Tyrosine kinase inhibitors inhibit fungal cell entry into epithelial cells and phagocytosis. Quinolone and other antibiotics may augment activity of azole and polyene agents. The correlation of in vitro effects with clinically meaningful in vivo systems is warranted.
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Affiliation(s)
- Sharon C-A Chen
- Centre for Infectious Diseases and Microbiology, Westmead Hospital, University of Sydney, Westmead, NSW Australia
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Bartoszewska M, Kiel JAKW. The role of macroautophagy in development of filamentous fungi. Antioxid Redox Signal 2011; 14:2271-87. [PMID: 20712412 DOI: 10.1089/ars.2010.3528] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Autophagy (macroautophagy) is a bulk degradative pathway by which cytoplasmic components are delivered to the vacuole for recycling. This process is conserved from yeast to human, where it is implicated in cancer and neurodegenerative diseases. During the last decade, many ATG genes involved in autophagy have been identified, initially in Saccharomyces cerevisiae. This review summarizes the knowledge on the molecular mechanisms of autophagy using yeast as model system. Although many of the core components involved in autophagy are conserved from yeast to human, there are, nevertheless, significant differences between these organisms, for example, during autophagy initiation. Autophagy also plays an essential role in filamentous fungi especially during differentiation. Remarkably, in these species autophagy may reflect features of both yeast and mammals. This is exemplified by the finding that filamentous fungi lack the S. cerevisiae clade-specific Atg31 protein, but contain Atg101, which is absent in this clade. A reappraisal of genome data further suggests that, similar to yeast and mammals, filamentous fungi probably also contain two distinct phosphatidylinositol 3-kinase complexes. This review also summarizes the state of knowledge on the role of autophagy in filamentous fungi during differentiation, such as pathogenic development, programmed cell death during heteroincompatibility, and spore formation.
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Affiliation(s)
- Magdalena Bartoszewska
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Haren, The Netherlands
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50
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Chaieb K, Kouidhi B, Zmantar T, Mahdouani K, Bakhrouf A. Starvation survival of Candida albicans in various water microcosms. J Basic Microbiol 2011; 51:357-63. [PMID: 21656797 DOI: 10.1002/jobm.201000298] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Accepted: 12/13/2010] [Indexed: 11/09/2022]
Abstract
Candida is a major Human pathogen causing a variety of infections and can survive for extended period of time in aquatic environment including marine and fresh water. In this study we compared a colorimetric XTT assay to colony forming units (CFU) count to evaluate the survival potential of Candida albicans incubated in water microcosms. Our results showed that cells maintain cultivability within a long period followed by a decline in cultivability and a drop of plate counts to less than 20 cell ml(-1) after 150 days in tap water, 190 days in rain water and 200 days in seawater. In addition we noted that 10% of cells viability was reached after 150 days in seawater, 180 days in rain water and 210 days in tap water. Molecular method confirms the persistence of C. albicans cells in water during long time starvation period.
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Affiliation(s)
- Kamel Chaieb
- Laboratoire d'Analyses, Traitement et Valorisation des Polluants de l'Environnement et des Produits, Faculté de Pharmacie, Université de Monastir, Rue Avicenne 5000, Monastir, Tunisia.
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