1
|
Hefny ZA, Ji B, Elsemman IE, Nielsen J, Van Dijck P. Transcriptomic meta-analysis to identify potential antifungal targets in Candida albicans. BMC Microbiol 2024; 24:66. [PMID: 38413885 PMCID: PMC10898158 DOI: 10.1186/s12866-024-03213-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 02/06/2024] [Indexed: 02/29/2024] Open
Abstract
BACKGROUND Candida albicans is a fungal pathogen causing human infections. Here we investigated differential gene expression patterns and functional enrichment in C. albicans strains grown under different conditions. METHODS A systematic GEO database search identified 239 "Candida albicans" datasets, of which 14 were selected after rigorous criteria application. Retrieval of raw sequencing data from the ENA database was accompanied by essential metadata extraction from dataset descriptions and original articles. Pre-processing via the tailored nf-core pipeline for C. albicans involved alignment, gene/transcript quantification, and diverse quality control measures. Quality assessment via PCA and DESeq2 identified significant genes (FDR < = 0.05, log2-fold change > = 1 or <= -1), while topGO conducted GO term enrichment analysis. Exclusions were made based on data quality and strain relevance, resulting in the selection of seven datasets from the SC5314 strain background for in-depth investigation. RESULTS The meta-analysis of seven selected studies unveiled a substantial number of genes exhibiting significant up-regulation (24,689) and down-regulation (18,074). These differentially expressed genes were further categorized into 2,497 significantly up-regulated and 2,573 significantly down-regulated Gene Ontology (GO) IDs. GO term enrichment analysis clustered these terms into distinct groups, providing insights into the functional implications. Three target gene lists were compiled based on previous studies, focusing on central metabolism, ion homeostasis, and pathogenicity. Frequency analysis revealed genes with higher occurrence within the identified GO clusters, suggesting their potential as antifungal targets. Notably, the genes TPS2, TPS1, RIM21, PRA1, SAP4, and SAP6 exhibited higher frequencies within the clusters. Through frequency analysis within the GO clusters, several key genes emerged as potential targets for antifungal therapies. These include RSP5, GLC7, SOD2, SOD5, SOD1, SOD6, SOD4, SOD3, and RIM101 which exhibited higher occurrence within the identified clusters. CONCLUSION This comprehensive study significantly advances our understanding of the dynamic nature of gene expression in C. albicans. The identification of genes with enhanced potential as antifungal drug targets underpins their value for future interventions. The highlighted genes, including TPS2, TPS1, RIM21, PRA1, SAP4, SAP6, RSP5, GLC7, SOD2, SOD5, SOD1, SOD6, SOD4, SOD3, and RIM101, hold promise for the development of targeted antifungal therapies.
Collapse
Affiliation(s)
- Zeinab Abdelmoghis Hefny
- Laboratory of Molecular Cell Biology, Department of Biology, Katholieke Universiteit Leuven, Kasteelpark Arenberg 31, Leuven, B-3001, Belgium
| | - Boyang Ji
- BioInnovation Institute, Ole Maaløes Vej 3, Copenhagen, DK2200, Denmark
| | - Ibrahim E Elsemman
- Department of Information Systems, Faculty of Computers and Information, Assiut University, Assiut, 2071515, Egypt
| | - Jens Nielsen
- BioInnovation Institute, Ole Maaløes Vej 3, Copenhagen, DK2200, Denmark.
- Department of Life Sciences, Chalmers University of Technology, Kemivägen 10, SE41296, Gothenburg, SE41296, Sweden.
| | - Patrick Van Dijck
- Laboratory of Molecular Cell Biology, Department of Biology, Katholieke Universiteit Leuven, Kasteelpark Arenberg 31, Leuven, B-3001, Belgium.
| |
Collapse
|
2
|
Yang Y, Xie P, Li Y, Bi Y, Prusky DB. Updating Insights into the Regulatory Mechanisms of Calcineurin-Activated Transcription Factor Crz1 in Pathogenic Fungi. J Fungi (Basel) 2022; 8:jof8101082. [PMID: 36294647 PMCID: PMC9604740 DOI: 10.3390/jof8101082] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 10/06/2022] [Accepted: 10/10/2022] [Indexed: 11/05/2022] Open
Abstract
Ca2+, as a second messenger in cells, enables organisms to adapt to different environmental stresses by rapidly sensing and responding to external stimuli. In recent years, the Ca2+ mediated calcium signaling pathway has been studied systematically in various mammals and fungi, indicating that the pathway is conserved among organisms. The pathway consists mainly of complex Ca2+ channel proteins, calcium pumps, Ca2+ transporters and many related proteins. Crz1, a transcription factor downstream of the calcium signaling pathway, participates in regulating cell survival, ion homeostasis, infection structure development, cell wall integrity and virulence. This review briefly summarizes the Ca2+ mediated calcium signaling pathway and regulatory roles in plant pathogenic fungi. Based on discussing the structure and localization of transcription factor Crz1, we focus on the regulatory role of Crz1 on growth and development, stress response, pathogenicity of pathogenic fungi and its regulatory mechanisms. Furthermore, we explore the cross-talk between Crz1 and other signaling pathways. Combined with the important role and pathogenic mechanism of Crz1 in fungi, the new strategies in which Crz1 may be used as a target to explore disease control in practice are also discussed.
Collapse
Affiliation(s)
- Yangyang Yang
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, China
| | - Pengdong Xie
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, China
| | - Yongcai Li
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, China
- Correspondence:
| | - Yang Bi
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, China
| | - Dov B. Prusky
- Department of Postharvest Science, Agricultural Research Organization, Volcani Center, Rishon LeZion 7505101, Israel
| |
Collapse
|
3
|
Squizani ED, Reuwsaat JC, Motta H, Tavanti A, Kmetzsch L. Calcium: a central player in Cryptococcus biology. FUNGAL BIOL REV 2021. [DOI: 10.1016/j.fbr.2021.03.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
4
|
Li W, Shrivastava M, Lu H, Jiang Y. Calcium-calcineurin signaling pathway in Candida albicans: A potential drug target. Microbiol Res 2021; 249:126786. [PMID: 33989979 DOI: 10.1016/j.micres.2021.126786] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 04/27/2021] [Accepted: 05/03/2021] [Indexed: 12/26/2022]
Abstract
Increased morbidity and mortality of candidiasis are a notable threat to the immunocompromised patients. At present, the types of drugs available to treat C. albicans infection are relatively limited. Moreover, the emergence of antifungal drug resistance of C. albicans makes the treatment of C. albicans infection more difficult. The calcium-calcineurin signaling pathway plays a crucial role in the survival and pathogenicity of C. albicans and may act as a potential target against C. albicans. In this review, we summarized functions of the calcium-calcineurin signaling pathway in several biological processes, compared the differences of this signaling pathway between C. albicans and humans, and described anti-C. albicans activity of inhibitors of this signaling pathway. We believe that targeting the calcium-calcineurin signaling pathway is a promising strategy to cope with C. albicans infection.
Collapse
Affiliation(s)
- Wanqian Li
- Department of Pharmacology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | | | - Hui Lu
- Department of Pharmacology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
| | - Yuanying Jiang
- Department of Pharmacology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
| |
Collapse
|
5
|
Aequorin as a Useful Calcium-Sensing Reporter in Candida albicans. J Fungi (Basel) 2021; 7:jof7040319. [PMID: 33924126 PMCID: PMC8074299 DOI: 10.3390/jof7040319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 04/14/2021] [Accepted: 04/19/2021] [Indexed: 11/17/2022] Open
Abstract
In Candida albicans, calcium ions (Ca2+) regulate the activity of several signaling pathways, especially the calcineurin signaling pathway. Ca2+ homeostasis is also important for cell polarization, hyphal extension, and plays a role in contact sensing. It is therefore important to obtain accurate tools with which Ca2+ homeostasis can be addressed in this fungal pathogen. Aequorin from Aequorea victoria has been used in eukaryotic cells for detecting intracellular Ca2+. A codon-adapted aequorin Ca2+-sensing expression system was therefore designed for probing cytosolic Ca2+ flux in C. albicans. The availability of a novel water-soluble formulation of coelenterazine, which is required as a co-factor, made it possible to measure bioluminescence as a readout of intracellular Ca2+ levels in C. albicans. Alkaline stress resulted in an immediate influx of Ca2+ from the extracellular medium. This increase was exacerbated in a mutant lacking the vacuolar Ca2+ transporter VCX1, thus confirming its role in Ca2+ homeostasis. Using mutants in components of a principal Ca2+ channel (MID1, CCH1), the alkaline-dependent Ca2+ spike was greatly reduced, thus highlighting the crucial role of this channel complex in Ca2+ uptake and homeostasis. Exposure to the antiarrhythmic drug amiodarone, known to perturb Ca2+ trafficking, resulted in increased cytoplasmic Ca2+ within seconds that was abrogated by the chelation of Ca2+ in the external medium. Ca2+ import was also dependent on the Cch1/Mid1 Ca2+ channel in amiodarone-exposed cells. In conclusion, the aequorin Ca2+ sensing reporter developed here is an adequate tool with which Ca2+ homeostasis can be investigated in C. albicans.
Collapse
|
6
|
Cation Transporters of Candida albicans-New Targets to Fight Candidiasis? Biomolecules 2021; 11:biom11040584. [PMID: 33923411 PMCID: PMC8073359 DOI: 10.3390/biom11040584] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 04/14/2021] [Indexed: 02/07/2023] Open
Abstract
Candidiasis is the wide-spread fungal infection caused by numerous strains of yeast, with the prevalence of Candida albicans. The current treatment of candidiasis is becoming rather ineffective and costly owing to the emergence of resistant strains; hence, the exploration of new possible drug targets is necessary. The most promising route is the development of novel antibiotics targeting this pathogen. In this review, we summarize such candidates found in C. albicans and those involved in the transport of (metal) cations, as the latter are essential for numerous processes within the cell; hence, disruption of their fluxes can be fatal for C. albicans.
Collapse
|
7
|
Lange M, Peiter E. Calcium Transport Proteins in Fungi: The Phylogenetic Diversity of Their Relevance for Growth, Virulence, and Stress Resistance. Front Microbiol 2020; 10:3100. [PMID: 32047484 PMCID: PMC6997533 DOI: 10.3389/fmicb.2019.03100] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 12/20/2019] [Indexed: 12/26/2022] Open
Abstract
The key players of calcium (Ca2+) homeostasis and Ca2+ signal generation, which are Ca2+ channels, Ca2+/H+ antiporters, and Ca2+-ATPases, are present in all fungi. Their coordinated action maintains a low Ca2+ baseline, allows a fast increase in free Ca2+ concentration upon a stimulus, and terminates this Ca2+ elevation by an exponential decrease – hence forming a Ca2+ signal. In this respect, the Ca2+ signaling machinery is conserved in different fungi. However, does the similarity of the genetic inventory that shapes the Ca2+ peak imply that if “you’ve seen one, you’ve seen them all” in terms of physiological relevance? Individual studies have focused mostly on a single species, and mechanisms elucidated in few model organisms are usually extrapolated to other species. This mini-review focuses on the physiological relevance of the machinery that maintains Ca2+ homeostasis for growth, virulence, and stress responses. It reveals common and divergent functions of homologous proteins in different fungal species. In conclusion, for the physiological role of these Ca2+ transport proteins, “seen one,” in many cases, does not mean: “seen them all.”
Collapse
Affiliation(s)
- Mario Lange
- Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Faculty of Natural Sciences III, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany
| | - Edgar Peiter
- Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Faculty of Natural Sciences III, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany
| |
Collapse
|
8
|
Mid1 affects ion transport, cell wall integrity, and host penetration of the entomopathogenic fungus Metarhizium acridum. Appl Microbiol Biotechnol 2019; 103:1801-1810. [PMID: 30617534 DOI: 10.1007/s00253-018-09589-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 12/10/2018] [Accepted: 12/14/2018] [Indexed: 01/01/2023]
Abstract
Calcium signaling plays important roles in stress tolerance and virulence in fungi. Mid1, an accessory protein of Cch1 calcium channel, has been discussed in baker's yeast and some filamentous fungi. However, functions of the Mid1 gene in entomopathogenic fungi are not clear. In this study, the Mid1 gene was functionally characterized by deleting it in the entomopathogenic fungus Metarhizium acridum. The growth of the ΔMaMid1 mutant was similar as the wild type on normal growth medium, but inhibited by exogenous Ca2+, Fe2+, Mg2+, Mn2+, Li+, and calcium chelator ethylene glycol tetraacetic acid (EGTA). Cation transportation-related genes were upregulated and intracellular calcium concentration was decreased in ΔMaMid1. Deletion of the MaMid1 gene impaired the tolerance to cell wall-disrupting agents but had no impact on heat or ultraviolet irradiation tolerance compared with the wild type. Bioassays showed that ΔMaMid1 had decreased virulence, with defects in the ability to penetrate the host cuticle. Compared with the wild type, appressorium formation on locust wings and fungal growth in the insect hemocoel were significantly decreased in the ΔMaMid1 mutant in a bioassay through topical inoculation. The phenotypes of ΔMaMid1 were fully restored in a complementation strain. Taken together, our study demonstrates that the MaMid1 affects intracellular ion homeostasis and contributes to virulence by affecting the initial penetration process in M. acridum.
Collapse
|
9
|
Li Y, Sun L, Lu C, Gong Y, Li M, Sun S. Promising Antifungal Targets Against Candida albicans Based on Ion Homeostasis. Front Cell Infect Microbiol 2018; 8:286. [PMID: 30234023 PMCID: PMC6131588 DOI: 10.3389/fcimb.2018.00286] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 07/27/2018] [Indexed: 11/13/2022] Open
Abstract
In recent decades, invasive fungal infections have been increasing significantly, contributing to high incidences and mortality in immunosuppressed patients. Candida albicans (C. albicans) is the most prevalent opportunistic fungal pathogen in humans that can cause severe and often fatal bloodstream infections. Current antifungal agents have several limitations, including that only a small number of classes of antifungals are available, certain of which have severe toxicity and high cost. Moreover, the emergence of drug resistance is a new limitation to successful patient outcomes. Therefore, the development of antifungals with novel targets is an essential strategy for the efficient management of C. albicans infections. It is widely recognized that ion homeostasis is crucial for all living cells. Many studies have identified that ion-signaling and transduction networks are central to fungal survival by regulating gene expression, morphological transition, host invasion, stress response, and drug resistance. Dysregulation of ion homeostasis rapidly mediates cell death, forming the mechanistic basis of a growing number of compounds that elicit antifungal activity. Most of the potent antifungals have been widely used in the clinic, and certain of them have low toxicity, meaning that they may be expected to be used as antifungal drugs in the future. Hence, we briefly summarize the homeostasis regulation of several important ions, potential antifungal targets based on these ion-signaling networks, and antifungal compounds based on the disruption of ion homeostasis. This summary will help in designing effective drugs and identifying new targets for combating fungal diseases.
Collapse
Affiliation(s)
- Yiman Li
- School of Pharmaceutical Sciences, Shandong University, Jinan, China
| | - Licui Sun
- Department of Pharmacy, Feicheng Mining Central Hospital, Feicheng, China
| | - Chunyan Lu
- Department of Pharmacy, Qianfoshan Hospital Affiliated to Shandong University, Jinan, China
| | - Ying Gong
- School of Pharmaceutical Sciences, Shandong University, Jinan, China
| | - Min Li
- Department of Pharmacy, Qianfoshan Hospital Affiliated to Shandong University, Jinan, China
| | - Shujuan Sun
- Department of Pharmacy, Qianfoshan Hospital Affiliated to Shandong University, Jinan, China
| |
Collapse
|
10
|
Kim HS, Kim JE, Son H, Frailey D, Cirino R, Lee YW, Duncan R, Czymmek KJ, Kang S. Roles of three Fusarium graminearum membrane Ca 2+ channels in the formation of Ca 2+ signatures, growth, development, pathogenicity and mycotoxin production. Fungal Genet Biol 2017; 111:30-46. [PMID: 29175365 DOI: 10.1016/j.fgb.2017.11.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 11/11/2017] [Accepted: 11/15/2017] [Indexed: 02/06/2023]
Abstract
Similar to animals and plants, external stimuli cause dynamic spatial and temporal changes of cytoplasmic Ca2+ in fungi. Such changes are referred as the Ca2+ signature and control cellular responses by modulating the activity or location of diverse Ca2+-binding proteins (CBPs) and also indirectly affecting proteins that interact with CBPs. To understand the mechanism underpinning Ca2+ signaling, therefore, characterization of how Ca2+ moves to and from the cytoplasm to create Ca2+ signatures under different conditions is fundamental. Three genes encoding plasma membrane Ca2+ channels in a Fusarium graminearum strain that expresses a fluorescent protein-based Ca2+ indicator in the cytoplasm were mutagenized to investigate their roles in the generation of Ca2+ signatures under different growth conditions and genetic backgrounds. The genes disrupted include CCH1 and MID1, which encode a high affinity Ca2+ uptake system, and FIG1, encoding a low affinity Ca2+ channel. Resulting mutants were also analyzed for growth, development, pathogenicity and mycotoxin production to determine how loss of each of the genes alters these traits. To investigate whether individual genes influence the function and expression of other genes, phenotypes and Ca2+ signatures of their double and triple mutants, as well as their expression patterns, were analyzed.
Collapse
Affiliation(s)
- Hye-Seon Kim
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA; Delaware Biotechnology Institute, Newark, DE 19711, USA
| | - Jung-Eun Kim
- Department of Plant Pathology & Environmental Microbiology, Pennsylvania State University, University Park, PA 16802, USA
| | - Hokyoung Son
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Daniel Frailey
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Robert Cirino
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Yin-Won Lee
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Randall Duncan
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Kirk J Czymmek
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA; Delaware Biotechnology Institute, Newark, DE 19711, USA
| | - Seogchan Kang
- Department of Plant Pathology & Environmental Microbiology, Pennsylvania State University, University Park, PA 16802, USA.
| |
Collapse
|
11
|
Effects of Disruption of PMC1 in the tfp1∆/∆ Mutant on Calcium Homeostasis, Oxidative and Osmotic Stress Resistance in Candida albicans. Mycopathologia 2017; 183:315-327. [PMID: 29086141 DOI: 10.1007/s11046-017-0216-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 10/17/2017] [Indexed: 10/18/2022]
Abstract
The vacuolar-type H+-ATPase (V-ATPase) is essential for many cell processes. Our previous study has demonstrated that Tfp1 is a putative subunit of V-ATPase, loss of which causes disorders in calcium homeostasis and decreased resistance to oxidative stress. In this study, we found that further deletion of PMC1, a vacuolar calcium pump, in tfp1∆/∆ mutant led to more severe dysregulation of calcium homeostasis. Besides, the tfp1∆/∆pmc1∆/∆ mutant was more sensitive to H2O2 and had a higher ROS level. As is known, V-ATPase mutants are sensitive to NaCl, and PMC1 mutant is resistant against NaCl. However, the tfp1∆/∆pmc1∆/∆ mutant exhibited sensitivity to NaCl. Mechanism study demonstrated that their sensitivity was associated with reduced osmotic resistance caused by relatively low expression of GPD1. In addition, we first found that NaCl addition significantly declined ROS levels in tfp1∆/∆ and tfp1∆/∆pmc1∆/∆ mutants. In tfp1∆/∆ mutant, decreased ROS levels were relevant to enhanced antioxidant activities. However, in tfp1∆/∆pmc1∆/∆ mutant, reduced ROS resulted from decreased total calcium content, revealing that NaCl affected ROS levels in the two mutants through different mechanisms. Taken together, our data indicated that loss of both TFP1 and PMC1 further affected calcium homeostasis and other cellular processes in Candida albicans and provides a potential antifungal target.
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
Dong Y, Zhang D, Yu Q, Zhao Q, Xiao C, Zhang K, Jia C, Chen S, Zhang B, Zhang B, Li M. Loss of Ssq1 leads to mitochondrial dysfunction, activation of autophagy and cell cycle arrest due to iron overload triggered by mitochondrial iron-sulfur cluster assembly defects in Candida albicans. Int J Biochem Cell Biol 2017; 85:44-55. [PMID: 28163187 DOI: 10.1016/j.biocel.2017.01.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Revised: 12/30/2016] [Accepted: 01/29/2017] [Indexed: 01/10/2023]
Abstract
Iron-sulfur clusters perform essential functions in enzymatic catalysis and homeostatic regulation. Here we for the first time identified Ssq1 as an essential component for iron-sulfur cluster assembly in Candida albicans. Ssq1 played an important role in cell growth. Shutting off SSQ1 led to accumulation of intracellular iron, especially in mitochondria, and disorder of intracellular iron regulation. In tetO-SSQ1, iron overloading triggered the oxidative damage of mitochondrial function. Surprisingly, disruption of SSQ1 activated autophagic pathway. The mitochondrial dysfunction was further aggravated when CCZ1 (which is essential for autophagy) and SSQ1 was simultaneously deleted, suggesting that autophagy played a critical role in maintenance of mitochondrial function in tetO-SSQ1. In addition, double deletion of SSQ1 and CCZ1 further elevated cellular iron levels in comparison with tetO-SSQ1, indicating that autophagy participated in maintenance of iron homeostasis. Furthermore, we found that loss of SSQ1 led to increasing protein expression of Rnr1 and redistribution of Rnr2 from the nucleus to cytoplasm, and further resulted in cell cycle arrest. The results implied that cell cycle arrest was caused by activating the checkpoint pathway because of impairing the iron-sulfur cluster assembly in tetO-SSQ1. Shutting off SSQ1 led to a significant defect in filamentous development. Interestingly, the tetO-SSQ1ccz1Δ/Δ growth was inhibited on hyphae-inducing solid media. Both tetO-SSQ1 and tetO-SSQ1ccz1Δ/Δ exhibited extremely attenuated virulence, indicating that Ssq1 might provide a promising target for antifungal drugs development. In summary, our findings provide new insights into the understanding of iron-sulfur cluster assembly-related gene in C. albicans.
Collapse
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; The State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, PR China
| | - Dan Zhang
- 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
| | - Qiang Zhao
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, PR China
| | - Chenpeng Xiao
- 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
| | - Chang Jia
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, PR China
| | - Sijia Chen
- 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
| | - Biao Zhang
- Tianjin University of Traditional Chinese Medicine, 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.
| |
Collapse
|
14
|
Liu P, Gong J, Ding X, Jiang Y, Chen G, Li B, Weng Q, Chen Q. The L-type Ca(2+) Channel Blocker Nifedipine Inhibits Mycelial Growth, Sporulation, and Virulence of Phytophthora capsici. Front Microbiol 2016; 7:1236. [PMID: 27540377 PMCID: PMC4972815 DOI: 10.3389/fmicb.2016.01236] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 07/25/2016] [Indexed: 11/19/2022] Open
Abstract
The oomycete vegetable pathogen Phytophthora capsici causes significant losses of important vegetable crops worldwide. Calcium and other plant nutrients have been used in disease management of oomycete pathogens. Calcium homeostasis and signaling is essential for numerous biological processes, and Ca(2+) channel blockers prevent excessive Ca(2+) influx into the fungal cell. However, it is not known whether voltage-gated Ca(2+) channel blockers improve control over oomycete pathogens. In the present study, we compared the inhibitory effects of CaCl2 and the extracellular Ca(2+) chelator EDTA on mycelial growth and found that calcium assimilation plays a key role in P. capsici mycelial growth. Next, we involved the voltage-gated Ca(2+) channel blockers verapamil (VP) and nifedipine (NFD) to analyze the effect of Ca(2+) channel blockers on mycelial growth and sporulation; the results suggested that NFD, but not VP, caused significant inhibition. Ion rescue in an NFD-induced inhibition assay suggested that NFD-induced inhibition is calcium-dependent. In addition, NFD increased P. capsici sensitivity to H2O2 in a calcium-dependent manner, and extracellular calcium rescued it. Furthermore, NFD inhibited the virulence and gene expression related to its pathogenicity. These results suggest that NFD inhibits mycelial growth, sporulation, and virulence of P. capsici.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Qiyong Weng
- Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Institute of Plant Protection, Fujian Academy of Agricultural SciencesFuzhou, China
| | - Qinghe Chen
- Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Institute of Plant Protection, Fujian Academy of Agricultural SciencesFuzhou, China
| |
Collapse
|
15
|
Ma F, Zhang Y, Wang Y, Wan Y, Miao Y, Ma T, Yu Q, Li M. Role of Aif1 in regulation of cell death under environmental stress in Candida albicans. Yeast 2016; 33:493-506. [PMID: 27121326 DOI: 10.1002/yea.3167] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 04/10/2016] [Accepted: 04/12/2016] [Indexed: 01/31/2023] Open
Abstract
Apoptosis-inducing factor (AIF) is a conserved flavoprotein localized in the mitochondria, inducing apoptosis after translocation into the nucleus. However, its role in the important fungal pathogen, Candida albicans, remains to be investigated. In this study, we find that the C. albicans AIF protein Aif1, similar to its homologues in other organisms, is localized at the mitochondria and translocated into the nucleus under apoptosis-inducing conditions. Moreover, deletion of AIF1 causes attenuated apoptosis in this pathogen under apoptosis-inducing conditions, such as the treatment of 2 mm H2 O2 , 10 mm acetic acid or 0.08 mg/l caspofungin, and its overexpression enhances this process. Interestingly, treatment with high levels of these agents leads to reversed sensitivity of aif1Δ/Δ and the overexpression strain AIF1ov. In addition, the virulence of C. albicans is not affected by deletion or overexpression of AIF1. Hence, C. albicans Aif1, as a mitochondria-localized protein, plays a dual role in the regulation of cell death under different concentrations of the stress-caused agents. Copyright © 2016 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Feiyang Ma
- Key Laboratory of Molecular Microbiology and Technology, College of Life Sciences, Nankai University, Tianjin, People's Republic of China
| | - Yueqi Zhang
- Key Laboratory of Molecular Microbiology and Technology, College of Life Sciences, Nankai University, Tianjin, People's Republic of China
| | - Yuzhou Wang
- Laboratory Animal Centre, College of Life Sciences, Nankai University, Tianjin, People's Republic of China
| | - Yajuan Wan
- College of Life Sciences, Nankai University, Tianjin, People's Republic of China
| | - Yunheng Miao
- Key Laboratory of Molecular Microbiology and Technology, College of Life Sciences, Nankai University, Tianjin, People's Republic of China
| | - Tianyu Ma
- Key Laboratory of Molecular Microbiology and Technology, College of Life Sciences, Nankai University, Tianjin, People's Republic of China
| | - Qilin Yu
- Key Laboratory of Molecular Microbiology and Technology, College of Life Sciences, Nankai University, Tianjin, People's Republic of China
| | - Mingchun Li
- Key Laboratory of Molecular Microbiology and Technology, College of Life Sciences, Nankai University, Tianjin, People's Republic of China
| |
Collapse
|
16
|
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.
Collapse
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.
| |
Collapse
|
17
|
The Cch1-Mid1 High-Affinity Calcium Channel Contributes to the Virulence of Cryptococcus neoformans by Mitigating Oxidative Stress. EUKARYOTIC CELL 2015; 14:1135-43. [PMID: 26385891 DOI: 10.1128/ec.00100-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 09/12/2015] [Indexed: 01/20/2023]
Abstract
Pathogenic fungi have developed mechanisms to cope with stresses imposed by hosts. For Cryptococcus spp., this implies active defense mechanisms that attenuate and ultimately overcome the onslaught of oxidative stresses in macrophages. Among cellular pathways within Cryptococcus neoformans' arsenal is the plasma membrane high-affinity Cch1-Mid1 calcium (Ca(2+)) channel (CMC). Here we show that CMC has an unexpectedly complex and disparate role in mitigating oxidative stress. Upon inhibiting the Ccp1-mediated oxidative response pathway with antimycin, strains of C. neoformans expressing only Mid1 displayed enhanced growth, but this was significantly attenuated upon H2O2 exposure in the absence of Mid1, suggesting a regulatory role for Mid1 acting through the Ccp1-mediated oxidative stress response. This notion is further supported by the interaction detected between Mid1 and Ccp1 (cytochrome c peroxidase). In contrast, Cch1 appears to have a more general role in promoting cryptococci survival during oxidative stress. A strain lacking Cch1 displayed a growth defect in the presence of H2O2 without BAPTA [(1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, cesium salt] or additional stressors such as antimycin. Consistent with a greater contribution of Cch1 to oxidative stress tolerance, an intracellular growth defect was observed for the cch1Δ strain in the macrophage cell line J774A.1. Interestingly, while the absence of either Mid1 or Cch1 significantly compromises the ability of C. neoformans to tolerate oxidative stress, the absence of both Mid1 and Cch1 has a negligible effect on C. neoformans growth during H2O2 stress, suggesting the existence of a compensatory mechanism that becomes active in the absence of CMC.
Collapse
|
18
|
Xu D, Cheng J, Cao C, Wang L, Jiang L. Genetic interactions between Rch1 and the high-affinity calcium influx system Cch1/Mid1/Ecm7 in the regulation of calcium homeostasis, drug tolerance, hyphal development and virulence in Candida albicans. FEMS Yeast Res 2015; 15:fov079. [PMID: 26323599 DOI: 10.1093/femsyr/fov079] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/17/2015] [Indexed: 12/13/2022] Open
Abstract
The high-affinity calcium influx system (HACS) consisted of CaCch1, CaMid1 and CaEcm7 controls calcium influx into the cell in response to environmental stimuli. The plasma membrane protein CaRch1 is a negative regulator of calcium influx in Candida albicans. In this study, we show that deletion of any of the HACS components suppresses the calcium hypersensitivity of, and the elevated activation level of calcium/calcineurin signaling in, C. albicans cells lacking CaRCH1. In contrast, CaRCH1 is epistatic to the HACS system in the tolerance of antifungal drugs. In addition, cells lacking CaRCH1 are sensitive to tunicamycin, show a delay in in vitro filamentation and an altered colony surface morphology, and are attenuated in virulence in a mouse systemic model. Cells lacking CaCCH1 and CaMID1, but not CaECM7, are sensitive to tunicamycin. Deletion of CaRCH1 increases the tunicamycin sensitivity of cells lacking CaECM7 or CaMID1, but not CaCCH1. Furthermore, deletion of CaRCH1 suppresses the defect in hyphal development due to the deletion of CaCCH1 or CaECM7, and increases the virulence of cells lacking any of the HACS components. Therefore, CaRch1 genetically interacts with the HACS components in different fashions for these functions.
Collapse
Affiliation(s)
- Dayong Xu
- The National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China College of Life Sciences, Huaibei Normal University, Huaibei 235000, Anhui, China
| | - Jianqing Cheng
- School of Medicine, Jiangnan University, Wuxi 214122, China
| | - Chunlei Cao
- The National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Litong Wang
- The National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Linghuo Jiang
- The National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| |
Collapse
|
19
|
Wang Y, Wang J, Cheng J, Xu D, Jiang L. Genetic interactions between the Golgi Ca2+/H+ exchanger Gdt1 and the plasma membrane calcium channel Cch1/Mid1 in the regulation of calcium homeostasis, stress response and virulence in Candida albicans. FEMS Yeast Res 2015. [PMID: 26208803 DOI: 10.1093/femsyr/fov069] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The Golgi-localized Saccharomyces cerevisiae ScGdt1 is a member of the cation/Ca(2+) exchanger superfamily. We show here that Candida albicans CaGdt1 is the functional homolog of ScGdt1 in calcium sensitivity, and shows genetic interactions with CaCch1 or CaMid1 in response to ER stresses. In addition, similar to ScCCH1 and ScMID1, deletion of either CaCCH1 or CaMID1 leads to a growth sensitivity of cells to cold stress, which can be suppressed by deletion of CaGDT1. Furthermore, deletion of CaCCH1 leads to a severe delay in filamentation of C. albicans cells, and this defect is abolished by deletion of CaGDT1. In contrast, CaGDT1 does not show genetic interaction with CaMID1 in filamentation. Interestingly, C. albicans cells lacking both CaMID1 and CaGDT1 exhibit an intermediate virulence between C. albicans cells lacking CaCCH1 (non-virulent) and C. albicans cells lacking CaGDT1 (partially virulent), while C. albicans cells lacking both CaCCH1 and CaGDT1 are not virulent in a mouse model of systemic candidiasis. Therefore, CaGdt1 genetically interacts with the plasma membrane calcium channel, CaCch1/CaMid1, in the response of C. albicans cells to cold and ER stresses and antifungal drug challenge as well as in filamentation and virulence.
Collapse
Affiliation(s)
- Yanan Wang
- The National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Junjun Wang
- The National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Jianqing Cheng
- School of Medicine, Jiangnan University, Wuxi 214122, China
| | - Dayong Xu
- The National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Linghuo Jiang
- The National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| |
Collapse
|
20
|
Potential Targets for Antifungal Drug Discovery Based on Growth and Virulence in Candida albicans. Antimicrob Agents Chemother 2015. [PMID: 26195510 DOI: 10.1128/aac.00726-15] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fungal infections, especially infections caused by Candida albicans, remain a challenging problem in clinical settings. Despite the development of more-effective antifungal drugs, their application is limited for various reasons. Thus, alternative treatments with drugs aimed at novel targets in C. albicans are needed. Knowledge of growth and virulence in fungal cells is essential not only to understand their pathogenic mechanisms but also to identify potential antifungal targets. This article reviews the current knowledge of the mechanisms of growth and virulence in C. albicans and examines potential targets for the development of new antifungal drugs.
Collapse
|
21
|
Abstract
Only few Candida species, e.g., Candida albicans, Candida glabrata, Candida dubliniensis, and Candida parapsilosis, are successful colonizers of a human host. Under certain circumstances these species can cause infections ranging from superficial to life-threatening disseminated candidiasis. The success of C. albicans, the most prevalent and best studied Candida species, as both commensal and human pathogen depends on its genetic, biochemical, and morphological flexibility which facilitates adaptation to a wide range of host niches. In addition, formation of biofilms provides additional protection from adverse environmental conditions. Furthermore, in many host niches Candida cells coexist with members of the human microbiome. The resulting fungal-bacterial interactions have a major influence on the success of C. albicans as commensal and also influence disease development and outcome. In this chapter, we review the current knowledge of important survival strategies of Candida spp., focusing on fundamental fitness and virulence traits of C. albicans.
Collapse
Affiliation(s)
- Melanie Polke
- Research Group Microbial Immunology, Hans-Knoell-Institute, Jena, Germany; Department Microbial Pathogenicity Mechanisms, Hans-Knoell-Institute, Jena, Germany
| | - Bernhard Hube
- Department Microbial Pathogenicity Mechanisms, Hans-Knoell-Institute, Jena, Germany; Friedrich-Schiller-University, Jena, Germany; Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany
| | - Ilse D Jacobsen
- Research Group Microbial Immunology, Hans-Knoell-Institute, Jena, Germany; Friedrich-Schiller-University, Jena, Germany
| |
Collapse
|
22
|
Components of the calcium-calcineurin signaling pathway in fungal cells and their potential as antifungal targets. EUKARYOTIC CELL 2015; 14:324-34. [PMID: 25636321 DOI: 10.1128/ec.00271-14] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
In recent years, the emergence of fungal resistance has become frequent, partly due to the widespread clinical use of fluconazole, which is minimally toxic and effective in the prevention and treatment of Candida albicans infections. The limited selection of antifungal drugs for clinical fungal infection therapy has prompted us to search for new antifungal drug targets. Calcium, which acts as the second messenger in both mammals and fungi, plays a direct role in controlling the expression patterns of its signaling systems and has important roles in cell survival. In addition, calcium and some of the components, mainly calcineurin, in the fungal calcium signaling pathway mediate fungal resistance to antifungal drugs. Therefore, an overview of the components of the fungal calcium-calcineurin signaling network and their potential roles as antifungal targets is urgently needed. The calcium-calcineurin signaling pathway consists of various channels, transporters, pumps, and other proteins or enzymes. Many transcriptional profiles have indicated that mutant strains that lack some of these components are sensitized to fluconazole or other antifungal drugs. In addition, many researchers have identified efficient compounds that exhibit antifungal activity by themselves or in combination with antifungal drugs by targeting some of the components in the fungal calcium-calcineurin signaling pathway. This targeting disrupts Ca(2+) homeostasis, which suggests that this pathway contains potential targets for the development of new antifungal drugs.
Collapse
|
23
|
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.
Collapse
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.
| |
Collapse
|
24
|
de Castro PA, Chiaratto J, Winkelströter LK, Bom VLP, Ramalho LNZ, Goldman MHS, Brown NA, Goldman GH. The involvement of the Mid1/Cch1/Yvc1 calcium channels in Aspergillus fumigatus virulence. PLoS One 2014; 9:e103957. [PMID: 25083783 PMCID: PMC4118995 DOI: 10.1371/journal.pone.0103957] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 07/03/2014] [Indexed: 11/30/2022] Open
Abstract
Aspergillus fumigatus is a major opportunistic pathogen and allergen of mammals. Calcium homeostasis and signaling is essential for numerous biological processes and also influences A. fumigatus pathogenicity. The presented study characterized the function of the A. fumigatus homologues of three Saccharomyces cerevisiae calcium channels, voltage-gated Cch1, stretch-activated Mid1 and vacuolar Yvc1. The A. fumigatus calcium channels cchA, midA and yvcA were regulated at transcriptional level by increased calcium levels. The YvcA::GFP fusion protein localized to the vacuoles. Both ΔcchA and ΔmidA mutant strains showed reduced radial growth rate in nutrient-poor minimal media. Interestingly, this growth defect in the ΔcchA strain was rescued by the exogenous addition of CaCl2. The ΔcchA, ΔmidA, and ΔcchA ΔmidA strains were also sensitive to the oxidative stress inducer, paraquat. Restriction of external Ca2+ through the addition of the Ca2+-chelator EGTA impacted upon the growth of the ΔcchA and ΔmidA strains. All the A. fumigatus ΔcchA, ΔmidA, and ΔyvcA strains demonstrated attenuated virulence in a neutropenic murine model of invasive pulmonary aspergillosis. Infection with the parental strain resulted in a 100% mortality rate at 15 days post-infection, while the mortality rate of the ΔcchA, ΔmidA, and ΔyvcA strains after 15 days post-infection was only 25%. Collectively, this investigation strongly indicates that CchA, MidA, and YvcA play a role in A. fumigatus calcium homeostasis and virulence.
Collapse
Affiliation(s)
- Patrícia Alves de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Jéssica Chiaratto
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Lizziane K. Winkelströter
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Vinícius Leite Pedro Bom
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | | | - Maria Helena S. Goldman
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Neil Andrew Brown
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
- National Laboratory of Science and Technology of Bioethanol (CTBE), Campinas, Brazil
- * E-mail:
| |
Collapse
|
25
|
Yu Q, Ding X, Zhang B, Xu N, Jia C, Mao J, Zhang B, Xing L, Li M. Inhibitory effect of verapamil on Candida albicans hyphal development, adhesion and gastrointestinal colonization. FEMS Yeast Res 2014; 14:633-41. [PMID: 24650198 DOI: 10.1111/1567-1364.12150] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 02/11/2014] [Accepted: 03/04/2014] [Indexed: 11/27/2022] Open
Abstract
Candida albicans morphogenesis and gastrointestinal colonization are closely associated with the pathogenicity of this pathogen. This study investigated the in vitro and in vivo effect of verapamil, a calcium channel blocker, on these processes. Exposure to ≥ 10 μg mL(-1) verapamil led to a significant decrease of C. albicans hyphal cells. The ability to adhere to a polystyrene surface and buccal epithelial cells was inhibited by exposure to ≥ 20 μg mL(-1) verapamil. Detection of the Hwp1-green fluorescent protein fusion protein showed that verapamil inhibited expression and transport of Hwp1, indicating its activity against both the regulation network of morphogenesis-associated proteins and the secretory pathway in C. albicans. Moreover, treatment with verapamil at 10 mg (kg day)(-1) led to a remarkable decrease in gastrointestinal-colonizing fungal cells. This study revealed the inhibitory effect of verapamil on C. albicans hyphal development, adhesion and gastrointestinal colonization, which is relevant to decreased expression and abnormal transport of the proteins required for morphogenesis. Therefore, verapamil may be taken into account when choosing an antifungal therapy against C. albicans colonization and infection.
Collapse
Affiliation(s)
- Qilin Yu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin, China
| | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Ding X, Yu Q, Zhang B, Xu N, Jia C, Dong Y, Chen Y, Xing L, Li M. The type II Ca2+/calmodulin-dependent protein kinases are involved in the regulation of cell wall integrity and oxidative stress response in Candida albicans. Biochem Biophys Res Commun 2014; 446:1073-8. [PMID: 24661877 DOI: 10.1016/j.bbrc.2014.03.059] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 03/15/2014] [Indexed: 11/24/2022]
Abstract
The type II Ca(2+)/calmodulin-dependent protein kinases (CaMKs) are thought to play a vital role in cellular regulation in mammalian cells. Two genes CMK1 and CMK2 in the Candida albicans genome encode homologues of mammalian CaMKs. In this work, we constructed the cmk1Δ/Δ, the cmk2Δ/Δ and the cmk1Δ/Δcmk2Δ/Δ mutants and found that CaMKs function in cell wall integrity (CWI) and cellular redox regulation. Loss of either CMK1 or CMK2, or both resulted in increased expression of CWI-related genes under Calcofluor white (CFW) treatment. Besides, CaMKs are essential for the maintenance of cellular redox balance. Disruption of either CMK1 or CMK2, or both not only led to a significant increase of intracellular ROS levels, but also led to a decrease of the mitochondrial membrane potential (MMP), suggesting the important roles that CaMKs play in the maintenance of the mitochondrial function.
Collapse
Affiliation(s)
- Xiaohui Ding
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin, PR China
| | - Qilin Yu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin, PR China
| | - Bing Zhang
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin, PR China
| | - Ning Xu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin, PR China
| | - Chang Jia
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin, PR China
| | - Yijie Dong
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin, PR China
| | - Yulu Chen
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin, PR China
| | - Laijun Xing
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin, PR China
| | - Mingchun Li
- Department of Microbiology, College of Life Science, Nankai University, Tianjin 300071, PR China..
| |
Collapse
|
27
|
Yu Q, Xiao C, Zhang K, Jia C, Ding X, Zhang B, Wang Y, Li M. The calcium channel blocker verapamil inhibits oxidative stress response in Candida albicans. Mycopathologia 2014; 177:167-77. [PMID: 24577794 DOI: 10.1007/s11046-014-9735-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Accepted: 02/19/2014] [Indexed: 10/25/2022]
Abstract
Candida albicans is a common opportunistic fungal pathogen, causing both superficial candidiasis and life-threatening systemic infections in immune-compromised individuals. Calcium signaling is responsible for this pathogen in responding to several stresses, such as antifungal drugs, alkaline pH and membrane-perturbing agents. Our recent study revealed that it is also involved in oxidative stress response. In this study, we investigated the effect of verapamil, an L-type voltage-gated calcium channel blocker, on oxidative stress response in this fungus. The addition of verapamil resulted in increased sensitivity to the oxidative agent H2O2, which is associated with a decrease of calcium fluctuation under the stress. Moreover, this agent caused enhanced oxidative stress, with increased levels of ROS and enhanced dysfunction of the mitochondria under the oxidative stress. Further investigations in SOD activity, GSH contents and expression of oxidative stress response-related genes indicated that the effect of verapamil is related to the repression of oxidative stress response. Our findings demonstrated that verapamil has an inhibitory effect on oxidative stress response, confirming the relationship between calcium signaling and oxidative stress in C. albicans. Therefore, calcium channels may be potential targets for therapy to enhance the efficacy of oxidative stress against C. albicans-related infections.
Collapse
Affiliation(s)
- Qilin Yu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, Nankai University, Tianjin, 300071, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Alber J, Jiang L, Geyer J. CaRch1p does not functionally interact with the high-affinity Ca(2+) influx system (HACS) of Candida albicans. Yeast 2013; 30:449-57. [PMID: 24123457 DOI: 10.1002/yea.2981] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 09/06/2013] [Accepted: 09/16/2013] [Indexed: 11/09/2022] Open
Abstract
The plasma membrane protein CaRch1p of Candida albicans, homologous to the human solute carrier protein SLC10A7, is involved in the regulation of calcium homeostasis. C. albicans cells lacking CaRCH1 are hypersensitive to high extracellular Ca(2+) concentrations and show increased tolerance to ketoconazole (KCZ). We assume a higher basal Ca(2+) influx in the rch1/rch1 mutant strain at low extracellular Ca(2+) concentrations, which is not detrimental to C. albicans cells but may be sufficient to activate calcineurin, finally resulting in an increased tolerance to KCZ. However, at 8 µg/ml KCZ plus 3 mm Ca(2+) the rch1/rch1 mutant and the wild-type strains showed identical growth. By further increasing the Ca(2+) concentration to 30 mm, this phenotype was completely reversed and the rch1/rch1 mutant strain became extremely sensitive to 8 µg/ml KCZ, probably due to synergistic toxic effects of Ca(2+) and KCZ under these conditions. Furthermore, we aimed to clarify whether CaRch1p interacts with the Cch1p component of the voltage-gated calcium influx channel Cch1p/Mid1p in C. albicans cells. As disruption of the two alleles of CCH1 in the rch1/rch1 mutant strain did not alter its hypersensitivity to high extracellular Ca(2+) , and as this phenotype was completely abolished by low amounts of Mg(2+) in the rch1/rch1 mutant as well as in the cch1/cch1 rch1/rch1 double mutant, we conclude that CaRch1p is a functional component of the low-affinity calcium uptake system (LACS) system and does not functionally interact with Cch1p.
Collapse
Affiliation(s)
- Joerg Alber
- Institute of Pharmacology and Toxicology, Justus Liebig University of Giessen, Germany
| | | | | |
Collapse
|
29
|
Ding X, Yu Q, Xu N, Wang Y, Cheng X, Qian K, Zhao Q, Zhang B, Xing L, Li M. Ecm7, a regulator of HACS, functions in calcium homeostasis maintenance, oxidative stress response and hyphal development in Candida albicans. Fungal Genet Biol 2013; 57:23-32. [PMID: 23769872 DOI: 10.1016/j.fgb.2013.05.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 05/04/2013] [Accepted: 05/09/2013] [Indexed: 10/26/2022]
Abstract
Calcium is a universal messenger that translates diverse environmental stresses and developmental cues into specific cellular and developmental responses. In yeast, Cch1 and Mid1 function as part of a high affinity Ca²⁺ influx system (HACS) that becomes activated rapidly in response to sudden stimuli. Here, we report that Ecm7, a regulator of HACS, plays important roles in calcium homeostasis maintenance, oxidative stress response and hyphal development in Candida albicans. Disruption of ECM7 led to increased sensitivity to calcium-depleted conditions. Flow cytometry analysis revealed that Ecm7 mediated Ca²⁺ influx under high pH shock. Cycloheximide chase experiments further showed that MID1 deletion significantly decreased the stability of Ecm7. We also provided evidences that ecm7Δ/Δ cells were hypersensitive to oxidative stress. ECM7 deletion induced the degradation of Cap1 when exposed to H₂O₂ treatment. Besides, the ecm7Δ/Δ mutant showed a defect in hyphal development, which was accompanied with the decreased expression of hyphal related gene HWP1. Though subsequent experiments revealed that the ecm7Δ/Δ mutant showed similar virulence to the wild-type strain, the ability of invasion and diffusion of the mutant in mouse kidneys decreased. Taken together, Ecm7 plays important roles in the adaptation and pathogenicity of C. albicans.
Collapse
Affiliation(s)
- Xiaohui Ding
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin, PR China
| | | | | | | | | | | | | | | | | | | |
Collapse
|