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Targeting Virulence Factors of Candida albicans with Natural Products. Foods 2022; 11:foods11192951. [PMID: 36230026 PMCID: PMC9562657 DOI: 10.3390/foods11192951] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 09/11/2022] [Accepted: 09/16/2022] [Indexed: 11/17/2022] Open
Abstract
Natural products derived from natural resources, including nutritional functional food, play an important role in human health. In recent years, the study of anti-fungal and other properties of agri-foods and derived functional compounds has been a hot research topic. Candida albicans is a parasitic fungus that thrives on human mucosal surfaces, which are colonized through opportunistic infection. It is the most prevalent cause of invasive fungal infection in immunocompromised individuals, resulting in a wide variety of clinical symptoms. Moreover, the efficacy of classical therapeutic medications such as fluconazole is often limited by the development of resistance. There is an ongoing need for the development of novel and effective antifungal therapy and medications. Infection of C. albicans is influenced by a great quantity of virulence factors, like adhesion, invasion-promoting enzymes, mycelial growth, and phenotypic change, and among others. Furthermore, various natural products especially from food sources that target C. albicans virulence factors have been researched, providing promising prospects for C. albicans prevention and treatment. In this review, we discuss the virulence factors of C. albicans and how functional foods and derived functional compounds affect them. Our hope is that this review will stimulate additional thoughts and suggestions regarding nutritional functional food and therapeutic development for patients afflicted with C. albicans.
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Silva LC, Correia AF, Gomes JVD, Romão W, Motta LC, Fagg CW, Magalhães PO, Silveira D, Fonseca-Bazzo YM. Lycorine Alkaloid and Crinum americanum L. (Amaryllidaceae) Extracts Display Antifungal Activity on Clinically Relevant Candida Species. Molecules 2022; 27:molecules27092976. [PMID: 35566325 PMCID: PMC9100883 DOI: 10.3390/molecules27092976] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/03/2022] [Accepted: 05/04/2022] [Indexed: 11/16/2022] Open
Abstract
Candida species are the main fungal agents causing infectious conditions in hospital patients. The development of new drugs with antifungal potential, increased efficacy, and reduced toxicity is essential to face the challenge of fungal resistance to standard treatments. The aim of this study is to evaluate the in vitro antifungal effects of two crude extracts of Crinum americanum L., a rich alkaloid fraction and lycorine alkaloid, on the Candida species. As such, we used a disk diffusion susceptibility test, determined the minimum inhibitory concentration (MIC), and characterized the components of the extracts using Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (ESI FT-ICR MS). The extracts were found to have antifungal activity against various Candida species. The chemical characterization of the extracts indicated the presence of alkaloids such as lycorine and crinine. The Amaryllidaceae family has a promising antifungal potential. Furthermore, it was found that the alkaloid lycorine directly contributes to the effects that were observed for the extracts and fraction of C. americanum.
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Affiliation(s)
- Lorene Coelho Silva
- Department of Pharmacy, Health Sciences School, University of Brasília (UnB), Campus Darcy Ribeiro, Asa Norte, Brasilia 70910-900, Brazil; (L.C.S.); (J.V.D.G.); (P.O.M.); (D.S.)
- Central Laboratory of the Federal District (LACEN-DF), Lotes O e P, Sgan 601, Asa Norte, Brasília 70830-010, Brazil;
| | - Amabel Fernandes Correia
- Central Laboratory of the Federal District (LACEN-DF), Lotes O e P, Sgan 601, Asa Norte, Brasília 70830-010, Brazil;
| | - João Victor Dutra Gomes
- Department of Pharmacy, Health Sciences School, University of Brasília (UnB), Campus Darcy Ribeiro, Asa Norte, Brasilia 70910-900, Brazil; (L.C.S.); (J.V.D.G.); (P.O.M.); (D.S.)
| | - Wanderson Romão
- Federal Institute of Espíırito Santo, Vila Velha 29106-010, Brazil;
- Petroleomic and Forensic Laboratory, Department of Chemistry, Federal University of Espírito Santo, Vitória 29075-910, Brazil;
| | - Larissa Campos Motta
- Petroleomic and Forensic Laboratory, Department of Chemistry, Federal University of Espírito Santo, Vitória 29075-910, Brazil;
| | - Christopher William Fagg
- Department of Botany, Institute of Biological Science, School of Pharmacy, Faculty of Ceilândia, University of Brasília, Brasilia 70910-900, Brazil;
| | - Pérola Oliveira Magalhães
- Department of Pharmacy, Health Sciences School, University of Brasília (UnB), Campus Darcy Ribeiro, Asa Norte, Brasilia 70910-900, Brazil; (L.C.S.); (J.V.D.G.); (P.O.M.); (D.S.)
| | - Dâmaris Silveira
- Department of Pharmacy, Health Sciences School, University of Brasília (UnB), Campus Darcy Ribeiro, Asa Norte, Brasilia 70910-900, Brazil; (L.C.S.); (J.V.D.G.); (P.O.M.); (D.S.)
| | - Yris Maria Fonseca-Bazzo
- Department of Pharmacy, Health Sciences School, University of Brasília (UnB), Campus Darcy Ribeiro, Asa Norte, Brasilia 70910-900, Brazil; (L.C.S.); (J.V.D.G.); (P.O.M.); (D.S.)
- Correspondence:
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Khona DK, Roy S, Ghatak S, Huang K, Jagdale G, Baker LA, Sen CK. Ketoconazole resistant Candida albicans is sensitive to a wireless electroceutical wound care dressing. Bioelectrochemistry 2021; 142:107921. [PMID: 34419917 PMCID: PMC8788813 DOI: 10.1016/j.bioelechem.2021.107921] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 07/27/2021] [Accepted: 07/31/2021] [Indexed: 01/22/2023]
Abstract
Wireless electroceutical dressing (WED) fabric kills bacteria and disrupts bacterial biofilm. This work tested, comparing with standard of care topical antibiotic ketoconazole, whether the weak electric field generated by WED is effective to manage infection caused by ketoconazole-resistant yeast Candida albicans. WED inhibited Candida albicans biofilm formation and planktonic growth. Unlike ketoconazole, WED inhibited yeast to hyphal transition and downregulated EAP1 curbing cell attachment. In response to WED-dependent down-regulation of biofilm-forming BRG1 and ROB1, BCR1 expression was markedly induced in what seems to be a futile compensatory response. WED induced NRG1 and TUP1, negative regulators of filamentation; it down-regulated EFG1, a positive regulator of hyphal pathway. Consistent with the anti-hyphal properties of WED, the expression of ALS3 and HWP1 were diminished. Ketoconazole failed to reproduce the effects of WED on NRG1, TUP1 and EFG1. WED blunted efflux pump activity; this effect was in direct contrast to that of ketoconazole. WED exposure compromised cellular metabolism. In the presence of ketoconazole, the effect was synergistic. Unlike ketoconazole, WED caused membrane depolarization, changes in cell wall composition and loss of membrane integrity. This work presents first evidence that weak electric field is useful in managing pathogens which are otherwise known to be antibiotic resistant.
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Affiliation(s)
- Dolly K Khona
- Indiana Center for Regenerative Medicine & Engineering, Indiana University Health Comprehensive Wound Center, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | - Sashwati Roy
- Indiana Center for Regenerative Medicine & Engineering, Indiana University Health Comprehensive Wound Center, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | - Subhadip Ghatak
- Indiana Center for Regenerative Medicine & Engineering, Indiana University Health Comprehensive Wound Center, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | - Kaixiang Huang
- Department of Chemistry, Indiana University, Bloomington, IN 47405, United States
| | - Gargi Jagdale
- Department of Chemistry, Indiana University, Bloomington, IN 47405, United States
| | - Lane A Baker
- Department of Chemistry, Indiana University, Bloomington, IN 47405, United States
| | - Chandan K Sen
- Indiana Center for Regenerative Medicine & Engineering, Indiana University Health Comprehensive Wound Center, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, United States.
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Inhibition of Distinct Proline- or N-Acetylglucosamine-Induced Hyphal Formation Pathways by Proline Analogs in Candida albicans. BIOMED RESEARCH INTERNATIONAL 2020; 2020:7245782. [PMID: 33274221 PMCID: PMC7695494 DOI: 10.1155/2020/7245782] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 10/23/2020] [Accepted: 10/29/2020] [Indexed: 11/22/2022]
Abstract
Candida albicans undergoes a yeast-to-hyphal transition that has been recognized as a virulence property as well as a turning point leading to biofilm formation associated with candidiasis. It is known that yeast-to-hyphal transition is induced under complex environmental conditions including temperature (above 35°C), pH (greater than 6.5), CO2, N-acetylglucosamine (GlcNAc), amino acids, RPMI-1640 synthetic culture medium, and blood serum. To identify the hyphal induction factor in the RPMI-1640 medium, we examined each component of RPMI-1640 and established a simple hyphal induction condition, that is, incubation in L-proline solution at 37°C. Incubation in GlcNAc solution alone, which is not contained in RPMI-1640, without any other materials was also identified as another simple hyphal induction condition. To inhibit hyphal formation, proline and GlcNAc analogs were examined. Among the proline analogs used, L-azetidine-2-carboxylic acid (AZC) inhibited hyphal induction under both induction conditions, but L-4-thiazolidinecarboxylic acid (T4C) specifically inhibited proline-induced hyphal formation only, while α-N-methyl-L-proline (mPro) selectively inhibited GlcNAc-induced hyphal formation. Hyphal formation in fetal bovine serum was also inhibited by AZC or T4C together with mPro without affecting the proliferation of yeast form. These results indicate that these proline analogs are ideal inhibitors of yeast-to-hyphal transition in C. albicans.
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Nair JJ, van Staden J. Insight to the antifungal properties of Amaryllidaceae constituents. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2020; 73:152753. [PMID: 30773353 DOI: 10.1016/j.phymed.2018.11.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 11/08/2018] [Accepted: 11/11/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND Fungal pathogenesis continues to be a burden to healthcare structures in both developed and developing nations. The gradual and irreversible loss of efficacies of existing antifungal medicines as well as the emergence of drug-resistant strains have contributed largely to this scenario. There is therefore a pressing need for new drugs from diverse structural backgrounds with improved potencies and novel modes of action to fortify or replace contemporary antifungal schedules. AIM Alkaloids of the plant family Amaryllidaceae exhibit good growth inhibitory activities against several fungal pathogens. This review focuses on the mechanistic aspects of these antifungal activities. It achieves this by highlighting the molecular targets as well as structural features of Amaryllidaceae constituents which serve to enhance such action. METHODS During the information gathering stage extensive use was made of the three database platforms; Google Scholar, SciFinder and Scopus. In most instances articles were accessed directly from journals licensed to the University of KwaZulu-Natal. In the absence of such proprietary agreements the respective corresponding authors were approached directly for copies of papers. RESULTS Although several classes of molecules from the Amaryllidaceae have been probed for their antifungal effects, it is the key constituents lycorine and narciclasine which have together afforded the most profound mechanistic insights. These may be summarized as follows: (i) effects on the fungal cell wall and cell membrane; (ii) effects on morphology such as budding and hyphal growth; (iii) effects on fungal organelles such as ribosomes; (iv) effects on macromolecules such as DNA, RNA and proteins and; (v) identification of the active sites for these constituents. CONCLUSION The key feature in the antifungal effects of Amaryllidaceae alkaloids is the inhibition of protein synthesis. This involved the inhibition of peptide bond formation by binding to yeast ribosomes via the 60S subunit. Related effects involved the inhibition of both DNA and RNA synthesis. These adverse effects were reflected morphologically on both the fungal cell wall and cell membrane. Such observations should prove useful in the chemotherapeutic arena should efforts shift towards the development of a clinical candidate.
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Affiliation(s)
- Jerald J Nair
- Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa
| | - Johannes van Staden
- Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa.
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Xia JL, Wu CG, Ren A, Hu YR, Wang SL, Han XF, Shi L, Zhu J, Zhao MW. Putrescine regulates nitric oxide accumulation in Ganoderma lucidum partly by influencing cellular glutamine levels under heat stress. Microbiol Res 2020; 239:126521. [PMID: 32575021 DOI: 10.1016/j.micres.2020.126521] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/27/2020] [Accepted: 05/30/2020] [Indexed: 11/28/2022]
Abstract
When fungi are subjected to abiotic stresses, the polyamines (PAs) level alter significantly. Here, we reveal that the polyamine putrescine (Put) could play an important role in alleviating heat stress(HS)-induced accumulation of nitric oxide (NO). Ornithine decarboxylase (ODC)-silenced mutants that were defective in Put biosynthesis exhibited significantly lower NO levels than the wild type (WT) when subjected to HS. With addition of 5 mM exogenous Put, the ODC-silenced mutant endogenous Put obviously increased under HS. At the same time, the contents of NO in the ODC-silenced mutants recovered to approximately WT levels after the administration of exogenous Put. However, the elevated NO content in the ODC-silenced mutants disappeared when exogenous Put and carboxy-PTIO (PTIO is a specific scavenger of NO) were added. Intriguingly, the content of glutamine (Gln) was significantly increased in the ODC-silenced strains. When exogenous Put was added to the WT, the Gln content was significantly decreased. The appearance of a high level of Gln was accompanied by nitrate reductase (NR) activity reduction. Further studies showed that Put influenced ganoderic acids (GAs) biosynthesis by regulating NO content, possibly through NR, under HS. Our work reported that Put regulates HS-induced NO accumulation by changing the cellular Gln level in filamentous fungi. IMPORTANCE: In our present work, it was HS as an ubiquitous environmental stress that affects the important pharmacological secondary metabolite (GAs) content in G. lucidum. Afterwards, we began to explore the network formed between multiple substances to jointly reduce the massive accumulation of GAs content caused by HS. We firstly focused on Put, a substance that enhances resistance to multiple stresses. Further, we discovered an influence on Put could changing the NO content, which has been shown to decrease the accumulation of GAs via HS. Then, we also found the change of NO content may be due to Put level that would affect intracellular Gln content. It has never been reported. And ultimately, it is Put related network that could reduce HS-inducing secondary metabolite mess in fungi.
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Affiliation(s)
- Jia-le Xia
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095 Jiangsu, People's Republic of China
| | - Chen-Gao Wu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095 Jiangsu, People's Republic of China
| | - Ang Ren
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095 Jiangsu, People's Republic of China
| | - Yan-Ru Hu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095 Jiangsu, People's Republic of China
| | - Sheng-Li Wang
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095 Jiangsu, People's Republic of China
| | - Xiao-Fei Han
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095 Jiangsu, People's Republic of China
| | - Liang Shi
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095 Jiangsu, People's Republic of China
| | - Jing Zhu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095 Jiangsu, People's Republic of China
| | - Ming-Wen Zhao
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095 Jiangsu, People's Republic of China.
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Abstract
Candida albicans has remained the main etiological agent of candidiasis, challenges clinicians with high mortality and morbidity. The emergence of resistance to antifungal drugs, toxicity and lower efficacy have all contributed to an urgent need to develop alternative drugs aiming at novel targets in C. albicans. Targeting the production of virulence factors, which are essential processes for infectious agents, represents an attractive substitute for the development of newer anti-infectives. The present review highlights the recent developments made in the understanding of the pathogenicity of C. albicans. Production of hydrolytic enzymes, morphogenesis and biofilm formation, along with their molecular and metabolic regulation in Candida are discussed with regard to the development of novel antipathogenic drugs against candidiasis. Over the last decade, candidiasis has remained a major problematic disease worldwide. In spite of the existence of many antifungal drugs, the treatment of such diseases has still remained unsuccessful due to drug inefficacy. Therefore, there is a need to discover antifungals with different modes of action, such as antipathogenic drugs against Candida albicans. Here, we describe how various types of virulence factors such as proteinase, phospholipase, hemolysin, adhesion, morphogenesis and biofilm formation, could be targeted to develop novel therapeutics. We can inhibit production of these virulence factors by controlling their molecular/metabolic regulation.
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Abstract
G-protein-coupled receptors (GPCRs) are the largest family of transmembrane receptors in fungi. These receptors have an important role in the transduction of extracellular signals into intracellular sites in response to diverse stimuli. They enable fungi to coordinate cell function and metabolism, thereby promoting their survival and propagation, and sense certain fundamentally conserved elements, such as nutrients, pheromones, and stress, for adaptation to their niches, environmental stresses, and host environment, causing disease and pathogen virulence. This chapter highlights the role of GPCRs in fungi in coordinating cell function and metabolism. Fungal cells sense the molecular interactions between extracellular signals. Their respective sensory systems are described here in detail.
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Affiliation(s)
- Abd El-Latif Hesham
- Department of Genetics Faculty of Agriculture, Beni-Suef University, Beni-Suef, Egypt
| | | | | | | | - Vijai Kumar Gupta
- AgroBioSciences and Chemical & Biochemical Sciences Department, University Mohammed VI Polytechnic (UM6P), Benguerir, Morocco
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Goffena J, Toenjes KA, Butler DK. Inhibition of yeast-to-filamentous growth transitions in Candida albicans by a small molecule inducer of mammalian apoptosis. Yeast 2017; 35:291-298. [PMID: 29048745 DOI: 10.1002/yea.3287] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 09/14/2017] [Accepted: 09/23/2017] [Indexed: 01/09/2023] Open
Abstract
The opportunistic fungal pathogen of humans Candida albicans is able to grow in different morphological forms such as round or oval yeasts and filamentous hyphae and pseudohyphae. Morphogenesis, the ability to switch between the yeast and filamentous growth forms, is important for adapting to new microenvironments in the human host and for pathogenesis. The molecular pathways governing morphogenesis are complex and incompletely understood. Previously, we identified several small organic molecules that specifically inhibit the initiation of hyphal growth in C. albicans without affecting cell viability or budded growth. One molecule from that screen is known to induce apoptosis in mammalian cells. In this study, we have screened additional inducers of mammalian apoptosis and identified BH3I-1, as well as several structural derivatives of BH3I-1, that act as specific inhibitors of morphogenesis under a variety of environmental conditions. Chemical epistasis experiments suggest that BH3I-1 acts downstream of the hypha-specific gene regulators Rfg1, Nrg1 and Ume6.
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Affiliation(s)
- Joy Goffena
- Department of Biological and Physical Sciences, Montana State University - Billings, Billings, Montana, 59101, USA
| | - Kurt A Toenjes
- Department of Biological and Physical Sciences, Montana State University - Billings, Billings, Montana, 59101, USA
| | - David K Butler
- Department of Biological and Physical Sciences, Montana State University - Billings, Billings, Montana, 59101, USA
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Bar-Yosef H, Vivanco Gonzalez N, Ben-Aroya S, Kron SJ, Kornitzer D. Chemical inhibitors of Candida albicans hyphal morphogenesis target endocytosis. Sci Rep 2017; 7:5692. [PMID: 28720834 PMCID: PMC5515890 DOI: 10.1038/s41598-017-05741-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 06/01/2017] [Indexed: 01/12/2023] Open
Abstract
Candida albicans is an opportunistic pathogen, typically found as a benign commensal yeast living on skin and mucosa, but poised to invade injured tissue to cause local infections. In debilitated and immunocompromised individuals, C. albicans may spread to cause life-threatening systemic infections. Upon contact with serum and at body temperature, C. albicans performs a regulated switch to filamentous morphology, characterized by emergence of a germ tube from the yeast cell followed by mold-like growth of branching hyphae. The ability to switch between growth morphologies is an important virulence factor of C. albicans. To identify compounds able to inhibit hyphal morphogenesis, we screened libraries of existing drugs for inhibition of the hyphal switch under stringent conditions. Several compounds that specifically inhibited hyphal morphogenesis were identified. Chemogenomic analysis suggested an interaction with the endocytic pathway, which was confirmed by direct measurement of fluid-phase endocytosis in the presence of these compounds. These results suggest that the activity of the endocytic pathway, which is known to be particularly important for hyphal growth, represents an effective target for hyphae-inhibiting drugs.
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Affiliation(s)
- Hagit Bar-Yosef
- Department of Molecular Microbiology, B. Rappaport Faculty of Medicine, Technion - I.I.T. and the Rappaport Institute for Research in the Medical Sciences, Haifa, 31096, Israel
| | - Nora Vivanco Gonzalez
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, 60637, USA
| | - Shay Ben-Aroya
- Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Stephen J Kron
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, 60637, USA.
| | - Daniel Kornitzer
- Department of Molecular Microbiology, B. Rappaport Faculty of Medicine, Technion - I.I.T. and the Rappaport Institute for Research in the Medical Sciences, Haifa, 31096, Israel.
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Kurakado S, Kurogane R, Sugita T. 17β-Estradiol inhibits estrogen binding protein-mediated hypha formation in Candida albicans. Microb Pathog 2017; 109:151-155. [PMID: 28552809 DOI: 10.1016/j.micpath.2017.05.038] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 05/03/2017] [Accepted: 05/24/2017] [Indexed: 11/25/2022]
Abstract
Candida albicans is one of the most prevalent and clinically important fungal pathogens. The ability to change form depending on environmental stress is an important microbial virulence factor. A survey of compounds that inhibit this morphological change identified various steroids, including 17β-estradiol. Interestingly, C. albicans has proteins capable of binding to steroids, including estrogen binding protein (Ebp1). Estrogens regulate cell differentiation and proliferation in humans through estrogen receptor proteins. To determine whether EBP1 regulates a virulence factor, we investigated the effect of 17β-estradiol on the morphological transition of C. albicans using an ebp1 deletion mutant. Treatment with 10 μg/mL of 17β-estradiol inhibited hypha formation, whereas its effect on the ebp1 deletion mutant was decreased compared to that on the wild-type and revertant strains. These data suggest a new pathway for the yeast-to-hypha transition via EBP1 in C. albicans.
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Affiliation(s)
- Sanae Kurakado
- Department of Microbiology, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, 204-8588, Japan.
| | - Rie Kurogane
- Department of Microbiology, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, 204-8588, Japan
| | - Takashi Sugita
- Department of Microbiology, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, 204-8588, Japan
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Kurakado S, Takatori K, Sugita T. Minocycline Inhibits Candida albicans Budded-to-Hyphal-Form Transition and Biofilm Formation. Jpn J Infect Dis 2017; 70:490-494. [PMID: 28367877 DOI: 10.7883/yoken.jjid.2016.369] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Candida albicans frequently causes bloodstream infections; its budded-to-hyphalform transition (BHT) and biofilm formation are major contributors to virulence. During an analysis of antibacterial compounds that inhibit C. albicans BHT, we found that the tetracycline derivative minocycline inhibited BHT and subsequent biofilm formation. Minocycline decreased expression of hypha-specific genes HWP1 and ECE1, and adhesion factor gene ALS3 of C. albicans. In addition, minocycline decreased cell surface hydrophobicity and the extracellular β-glucan level in biofilms. Minocycline has been widely used for catheter antibiotic lock therapy to prevent bacterial infection; this compound may also be prophylactically effective against Candida infection.
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Affiliation(s)
- Sanae Kurakado
- Department of Microbiology, Meiji Pharmaceutical University
| | - Kazuhiko Takatori
- Department of Pharmaceutical Molecular Design, Meiji Pharmaceutical University
| | - Takashi Sugita
- Department of Microbiology, Meiji Pharmaceutical University
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13
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Abstract
The high incidence and mortality of invasive fungal infections and serious drug resistance have become a global public health issue. The ability of fungal cells to form biofilms is an important reason for the emergence of severe resistance to most clinically available antifungal agents. Targeting fungal biofilm formation by small molecules represents a promising new strategy for the development of novel antifungal agents. This perspective will provide a comprehensive review of fungal biofilm inhibitors. In particular, discovery strategies, chemical structures, antibiofilm/antifungal activities, and structure-activity relationship studies will be discussed. Development of inhibitors to treat biofilm-related resistant fungal infections is a new yet clinically unexploited paradigm, and there is still a long way to go to clinical application. Better understanding of fungal biofilms in combination with systematic drug discovery efforts will pave the way for potential clinical applications.
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Affiliation(s)
- Shanchao Wu
- School of Pharmacy, Second Military Medical University , 325 Guohe Road, Shanghai 200433, People's Republic of China
| | - Yan Wang
- School of Pharmacy, Second Military Medical University , 325 Guohe Road, Shanghai 200433, People's Republic of China
| | - Na Liu
- School of Pharmacy, Second Military Medical University , 325 Guohe Road, Shanghai 200433, People's Republic of China
| | - Guoqiang Dong
- School of Pharmacy, Second Military Medical University , 325 Guohe Road, Shanghai 200433, People's Republic of China
| | - Chunquan Sheng
- School of Pharmacy, Second Military Medical University , 325 Guohe Road, Shanghai 200433, People's Republic of China
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Vila T, Romo JA, Pierce CG, McHardy SF, Saville SP, Lopez-Ribot JL. Targeting Candida albicans filamentation for antifungal drug development. Virulence 2016; 8:150-158. [PMID: 27268130 DOI: 10.1080/21505594.2016.1197444] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Candida albicans remains the main etiological agent of candidiasis, as this otherwise normal commensal of humans is capable of causing active infection in immune- and medically-compromised patients. The high morbidity and mortality rates associated with candidiasis, coupled with the emergence of drug resistance demand the development of novel therapeutic strategies. However, there is a paucity of selective targets that can be exploited in the development of new antifungals. Contrary to conventional antibiotics that kill or curtail growth, specifically targeting virulence mechanisms represents an attractive option for antifungal drug development. In C. albicans, a growing body of research over the last few decades has provided important insights into its virulence factors and their contribution to the pathogenesis of candidiasis. Of these, filamentation is the one that has received the most attention and perhaps shows the most promise as a target for new anti-virulence strategies to combat C. albicans infections.
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Affiliation(s)
- Taissa Vila
- a Department of Biology and South Texas Center for Emerging Infectious Diseases , The University of Texas at San Antonio , San Antonio , TX , USA
| | - Jesus A Romo
- a Department of Biology and South Texas Center for Emerging Infectious Diseases , The University of Texas at San Antonio , San Antonio , TX , USA
| | - Christopher G Pierce
- b Department of Biology , University of the Incarnate Word , San Antonio , TX , USA
| | - Stanton F McHardy
- c Department of Chemistry and Center for Innovative Drug Discovery , The University of Texas at San Antonio , San Antonio , TX , USA
| | - Stephen P Saville
- a Department of Biology and South Texas Center for Emerging Infectious Diseases , The University of Texas at San Antonio , San Antonio , TX , USA
| | - José L Lopez-Ribot
- a Department of Biology and South Texas Center for Emerging Infectious Diseases , The University of Texas at San Antonio , San Antonio , TX , USA
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15
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LeClaire LL, Fortwendel JR. Differential Support of Aspergillus fumigatus Morphogenesis by Yeast and Human Actins. PLoS One 2015; 10:e0142535. [PMID: 26555617 PMCID: PMC4640809 DOI: 10.1371/journal.pone.0142535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 10/22/2015] [Indexed: 12/15/2022] Open
Abstract
The actin cytoskeleton is highly conserved among eukaryotes and is essential for cellular processes regulating growth and differentiation. In fungi, filamentous actin (F-actin) orchestrates hyphal tip structure and extension via organization of exocytic and endocytic processes at the hyphal tip. Although highly conserved, there are key differences among actins of fungal species as well as between mammalian and fungal actins. For example, the F-actin stabilizing molecules, phalloidin and jasplakinolide, bind to actin structures in yeast and human cells, whereas phalloidin does not bind actin structures of Aspergillus. These discrepancies suggest structural differences between Aspergillus actin filaments and those of human and yeast cells. Additionally, fungal actin kinetics are much faster than those of humans, displaying 5-fold faster nucleation and 40-fold faster nucleotide exchange rates. Limited published studies suggest that these faster actin kinetics are required for normal growth and morphogenesis of yeast cells. In the current work, we show that replacement of Aspergillus actin with yeast actin generates a morphologically normal strain, suggesting that Aspergillus actin kinetics are similar to those of yeast. In contrast to wild type A. fumigatus, F-actin in this strain binds phalloidin, and pharmacological stabilization of these actin structures with jasplakinolide inhibits germination and alters morphogenesis in a dose-dependent manner. We also show that human β-actin cannot support Aspergillus viability, even though the amino acid sequences of human and Aspergillus actins are 89.3% identical. Our findings show that minor differences in actin protein sequence account for loss of phalloidin and jasplakinolide sensitivity in Aspergillus species.
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Affiliation(s)
- Lawrence L. LeClaire
- Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, Alabama, United States of America
| | - Jarrod R. Fortwendel
- Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile, Alabama, United States of America
- * E-mail:
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16
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Naruzawa ES, Bernier L. Control of yeast-mycelium dimorphism in vitro in Dutch elm disease fungi by manipulation of specific external stimuli. Fungal Biol 2014; 118:872-84. [PMID: 25442291 DOI: 10.1016/j.funbio.2014.07.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 07/18/2014] [Accepted: 07/30/2014] [Indexed: 10/24/2022]
Abstract
Dutch elm disease (DED) fungi exhibit yeast-mycelium dimorphism both in planta and in vitro. However, previously published data on the transition between these two growth forms in vitro were mostly obtained from a single strain. We examined the effect of six factors on yeast-mycelium dimorphism in vitro in ten strains of Ophiostoma ulmi, Ophiostoma novo-ulmi and Ophiostoma himal-ulmi. Nitrogen sources, calcium, and yeast extract, altogether with inhibitors of phosphodiesterase (caffeine) and dioxygenases (propyl gallate and salicylic acid) were tested in defined culture media. Morphological response to manipulation of several of these factors varied according to the strain of Ophiostoma being analysed. Responses ranged from no statistical differences in morphological transitions to stimulation or reversion of yeast-mycelium dimorphism with the treatments that were tested. These results suggest that different mechanisms and pathways operate in the control of the yeast-mycelium transition in DED pathogens. Oxylipins could be involved in the yeast-to-mycelium transition, since the addition of a dioxygenase inhibitor, salicylic acid, reduced mycelium production in all strains that were tested.
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Affiliation(s)
- Erika Sayuri Naruzawa
- Centre d'Étude de la Forêt (CEF) and Institut de Biologie intégrative et des Systèmes (IBIS), Canada
| | - Louis Bernier
- Centre d'Étude de la Forêt (CEF) and Institut de Biologie intégrative et des Systèmes (IBIS), Canada.
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17
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Wong SSW, Samaranayake LP, Seneviratne CJ. In pursuit of the ideal antifungal agent for Candida infections: high-throughput screening of small molecules. Drug Discov Today 2014; 19:1721-1730. [PMID: 24952336 DOI: 10.1016/j.drudis.2014.06.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 05/23/2014] [Accepted: 06/12/2014] [Indexed: 01/22/2023]
Abstract
Candida infections have created a great burden on the public healthcare sector. The situation is worsened by recent epidemiological changes. Furthermore, the current arsenal of antifungal agents is limited and associated with undesirable drawbacks. Therefore, new antifungal agents that surpass the existing ones are urgently needed. High-throughput screening of small molecule libraries enables rapid hit identification and, possibly, increases hit rate. Moreover, the identified hits could be associated with unrecognized or multiple drug targets, which would provide novel insights into the biological processes of the pathogen. Hence, it is proposed that high-throughput screening of small molecules is particularly important in the pursuit of the ideal antifungal agents for Candida infections.
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Affiliation(s)
- Sarah S W Wong
- Faculty of Dentistry, University of Hong Kong, Hong Kong
| | | | - Chaminda J Seneviratne
- Faculty of Dentistry, University of Hong Kong, Hong Kong; Oral Sciences, Faculty of Dentistry, National University of Singapore, Singapore.
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18
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Inhibition of Candida albicans virulence factors by novel levofloxacin derivatives. Appl Microbiol Biotechnol 2014; 98:6775-85. [DOI: 10.1007/s00253-014-5719-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Revised: 03/06/2014] [Accepted: 03/22/2014] [Indexed: 12/11/2022]
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19
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Wong SSW, Kao RYT, Yuen KY, Wang Y, Yang D, Samaranayake LP, Seneviratne CJ. In vitro and in vivo activity of a novel antifungal small molecule against Candida infections. PLoS One 2014; 9:e85836. [PMID: 24465737 PMCID: PMC3899067 DOI: 10.1371/journal.pone.0085836] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 12/02/2013] [Indexed: 12/01/2022] Open
Abstract
Candida is the most common fungal pathogen of humans worldwide and has become a major clinical problem because of the growing number of immunocompromised patients, who are susceptible to infection. Moreover, the number of available antifungals is limited, and antifungal-resistant Candida strains are emerging. New and effective antifungals are therefore urgently needed. Here, we discovered a small molecule with activity against Candida spp. both in vitro and in vivo. We screened a library of 50,240 small molecules for inhibitors of yeast-to-hypha transition, a major virulence attribute of Candida albicans. This screening identified 20 active compounds. Further examination of the in vitro antifungal and anti-biofilm properties of these compounds, using a range of Candida spp., led to the discovery of SM21, a highly potent antifungal molecule (minimum inhibitory concentration (MIC) 0.2 – 1.6 µg/ml). In vitro, SM21 was toxic to fungi but not to various human cell lines or bacterial species and was active against Candida isolates that are resistant to existing antifungal agents. Moreover, SM21 was relatively more effective against biofilms of Candida spp. than the current antifungal agents. In vivo, SM21 prevented the death of mice in a systemic candidiasis model and was also more effective than the common antifungal nystatin at reducing the extent of tongue lesions in a mouse model of oral candidiasis. Propidium iodide uptake assay showed that SM21 affected the integrity of the cell membrane. Taken together, our results indicate that SM21 has the potential to be developed as a novel antifungal agent for clinical use.
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Affiliation(s)
| | - Richard Yi Tsun Kao
- Department of Microbiology, University of Hong Kong, Hong Kong
- * E-mail: (CJS); (RYTK)
| | - Kwok Yong Yuen
- Department of Microbiology, University of Hong Kong, Hong Kong
| | - Yu Wang
- Department of Pharmacology & Pharmacy, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong
| | - Dan Yang
- Department of Chemistry, Faculty of Science, University of Hong Kong, Hong Kong
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20
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You J, Du L, King JB, Hall BE, Cichewicz RH. Small-molecule suppressors of Candida albicans biofilm formation synergistically enhance the antifungal activity of amphotericin B against clinical Candida isolates. ACS Chem Biol 2013; 8:840-8. [PMID: 23387427 DOI: 10.1021/cb400009f] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A new class of fungal biofilm inhibitors represented by shearinines D (3) and E (4) were obtained from a Penicillium sp. isolate. The inhibitory activities of 3 and 4 were characterized using a new imaging flow-cytometer technique, which enabled the rapid phenotypic analysis of Candida albicans cell types (budding yeast cells, germ tube cells, pseudohyphae, and hyphae) in biofilm populations. The results were confirmed by experimental data obtained from three-dimensional confocal laser scanning microscopy and 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assays. These data indicate that 3 and 4 inhibited C. albicans biofilm formation by blocking the outgrowth of hyphae at a relatively late stage of biofilm development (IC50 = 8.5 and 7.6 μM, respectively). However, 3 and 4 demonstrated comparatively weak activity at disrupting existing biofilms. Compounds 3 and 4 also exhibited synergistic activities with amphotericin B against C. albicans and other clinical Candida isolates by enhancing the potency of amphotericin B up to 8-fold against cells in both developing and established biofilms. These data suggest that the Candida biofilm disruption and amphotericin B potentiating effects of 3 and 4 could be mediated through multiple biological targets. The shearinines are good tools for testing the potential advantages of using adjunctive therapies in combination with antifungals.
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Affiliation(s)
- Jianlan You
- Natural Products Discovery Group,
Institute for Natural Products Applications and Research Technologies,
Stephenson Life Sciences Research Center, 101 Stephenson Parkway, University of Oklahoma, Norman, Oklahoma, 73019-5251,
United States
| | - Lin Du
- Natural Products Discovery Group,
Institute for Natural Products Applications and Research Technologies,
Stephenson Life Sciences Research Center, 101 Stephenson Parkway, University of Oklahoma, Norman, Oklahoma, 73019-5251,
United States
| | - Jarrod B. King
- Natural Products Discovery Group,
Institute for Natural Products Applications and Research Technologies,
Stephenson Life Sciences Research Center, 101 Stephenson Parkway, University of Oklahoma, Norman, Oklahoma, 73019-5251,
United States
| | - Brian E. Hall
- EMD Millipore, 645 Elliott Avenue West, Suite 100,
Seattle Washington 98119, United
States
| | - Robert H. Cichewicz
- Natural Products Discovery Group,
Institute for Natural Products Applications and Research Technologies,
Stephenson Life Sciences Research Center, 101 Stephenson Parkway, University of Oklahoma, Norman, Oklahoma, 73019-5251,
United States
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21
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Tsang PWK, Bandara HMHN, Fong WP. Purpurin suppresses Candida albicans biofilm formation and hyphal development. PLoS One 2012; 7:e50866. [PMID: 23226409 PMCID: PMC3511323 DOI: 10.1371/journal.pone.0050866] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 10/29/2012] [Indexed: 12/30/2022] Open
Abstract
A striking and clinically relevant virulence trait of the human fungal pathogen Candida albicans is its ability to grow and switch reversibly among different morphological forms. Inhibition of yeast-to-hypha transition in C. albicans represents a new paradigm for antifungal intervention. We have previously demonstrated the novel antifungal activity of purpurin against Candida fungi. In this study, we extended our investigation by examining the in vitro effect of purpurin on C. albicans morphogenesis and biofilms. The susceptibility of C. albicans biofilms to purpurin was examined quantitatively by 2,3-bis(2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide reduction assay. Hyphal formation and biofilm ultrastructure were examined qualitatively by scanning electron microscopy (SEM). Quantitative reverse transcription-PCR (qRT-PCR) was used to evaluate the expression of hypha-specific genes and hyphal regulator in purpurin-treated fungal cells. The results showed that, at sub-lethal concentration (3 µg/ml), purpurin blocked the yeast-to-hypha transition under hypha-inducing conditions. Purpurin also inhibited C. albicans biofilm formation and reduced the metabolic activity of mature biofilms in a concentration-dependent manner. SEM images showed that purpurin-treated C. albicans biofilms were scanty and exclusively consisted of aggregates of blastospores. qRT-PCR analyses indicated that purpurin downregulated the expression of hypha-specific genes (ALS3, ECE1, HWP1, HYR1) and the hyphal regulator RAS1. The data strongly suggested that purpurin suppressed C. albicans morphogenesis and caused distorted biofilm formation. By virtue of the ability to block these two virulence traits in C. albicans, purpurin may represent a potential candidate that deserves further investigations in the development of antifungal strategies against this notorious human fungal pathogen in vivo.
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Affiliation(s)
- Paul Wai-Kei Tsang
- Oral BioSciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.
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22
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Macherla C, Sanchez DA, Ahmadi MS, Vellozzi EM, Friedman AJ, Nosanchuk JD, Martinez LR. Nitric oxide releasing nanoparticles for treatment of Candida albicans burn infections. Front Microbiol 2012; 3:193. [PMID: 22701111 PMCID: PMC3370663 DOI: 10.3389/fmicb.2012.00193] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Accepted: 05/11/2012] [Indexed: 11/15/2022] Open
Abstract
Candida albicans is a leading fungal cause of burn infections in hospital settings, and sepsis is one of the principle causes of death after a severe burn. The prevalence of invasive candidiasis in burn cases varies widely, but it accounts for 3–23% of severe infection with a mortality rate ranging from 14 to 70%. Therefore, it is imperative that we develop innovative therapeutics to which this fungus is unlikely to evolve resistance, thus curtailing the associated morbidity and mortality and ultimately improving our capacity to treat these infections. An inexpensive and stable nitric oxide (NO)-releasing nanoparticle (NO-np) platform has been recently developed. NO is known to have direct antifungal activity, modulate host immune responses and significantly regulate wound healing. In this study, we hypothesized that NO-np would be an effective therapy in the treatment of C. albicans burn infections. Using a murine burn model, NO-np demonstrated antifungal activity against C. albicans in vivo, most likely by arresting its growth and morphogenesis as demonstrated in vitro. NO-np demonstrated effective antimicrobial activity against yeast and filamentous forms of the fungus. Moreover, we showed that NO-np significantly accelerated the rate of wound healing in cutaneous burn infections when compared to controls. The histological evaluation of the affected tissue revealed that NO-np treatment modified leukocyte infiltration, minimized the fungal burden, and reduced collagen degradation, thus providing potential mechanisms for the therapeutics’ biological activity. Together, these data suggest that NO-np have the potential to serve as a novel topical antifungal which can be used for the treatment of cutaneous burn infections and wounds.
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Thevissen K, de Mello Tavares P, Xu D, Blankenship J, Vandenbosch D, Idkowiak-Baldys J, Govaert G, Bink A, Rozental S, de Groot PWJ, Davis TR, Kumamoto CA, Vargas G, Nimrichter L, Coenye T, Mitchell A, Roemer T, Hannun YA, Cammue BPA. The plant defensin RsAFP2 induces cell wall stress, septin mislocalization and accumulation of ceramides in Candida albicans. Mol Microbiol 2012; 84:166-80. [PMID: 22384976 DOI: 10.1111/j.1365-2958.2012.08017.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The antifungal plant defensin RsAFP2 isolated from radish interacts with fungal glucosylceramides and induces apoptosis in Candida albicans. To further unravel the mechanism of RsAFP2 antifungal action and tolerance mechanisms, we screened a library of 2868 heterozygous C. albicans deletion mutants and identified 30 RsAFP2-hypersensitive mutants. The most prominent group of RsAFP2 tolerance genes was involved in cell wall integrity and hyphal growth/septin ring formation. Consistent with these genetic data, we demonstrated that RsAFP2 interacts with the cell wall of C. albicans, which also contains glucosylceramides, and activates the cell wall integrity pathway. Moreover, we found that RsAFP2 induces mislocalization of septins and blocks the yeast-to-hypha transition in C. albicans. Increased ceramide levels have previously been shown to result in apoptosis and septin mislocalization. Therefore, ceramide levels in C. albicans membranes were analysed following RsAFP2 treatment and, as expected, increased accumulation of phytoC24-ceramides in membranes of RsAFP2-treated C. albicans cells was detected. This is the first report on the interaction of a plant defensin with glucosylceramides in the fungal cell wall, causing cell wall stress, and on the effects of a defensin on septin localization and ceramide accumulation.
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Affiliation(s)
- Karin Thevissen
- Centre of Microbial and Plant Genetics (CMPG), Katholieke Universiteit Leuven, 3001 Heverlee, Belgium.
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24
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Midkiff J, Borochoff-Porte N, White D, Johnson DI. Small molecule inhibitors of the Candida albicans budded-to-hyphal transition act through multiple signaling pathways. PLoS One 2011; 6:e25395. [PMID: 21966518 PMCID: PMC3180447 DOI: 10.1371/journal.pone.0025395] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Accepted: 09/02/2011] [Indexed: 01/08/2023] Open
Abstract
The ability of the pathogenic yeast Candida albicans to interconvert between budded and hyphal growth states, herein termed the budded-to-hyphal transition (BHT), is important for C. albicans development and virulence. The BHT is under the control of multiple cell signaling pathways that respond to external stimuli, including nutrient availability, high temperature, and pH. Previous studies identified 21 small molecules that could inhibit the C. albicans BHT in response to carbon limitation in Spider media. However, the studies herein show that the BHT inhibitors had varying efficacies in other hyphal-inducing media, reflecting their varying abilities to block signaling pathways associated with the different media. Chemical epistasis analyses suggest that most, but not all, of the BHT inhibitors were acting through either the Efg1 or Cph1 signaling pathways. Notably, the BHT inhibitor clozapine, a FDA-approved drug used to treat atypical schizophrenia by inhibiting G-protein-coupled dopamine receptors in the brain, and several of its functional analogs were shown to act at the level of the Gpr1 G-protein-coupled receptor. These studies are the first step in determining the target and mechanism of action of these BHT inhibitors, which may have therapeutic anti-fungal utility in the future.
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Affiliation(s)
- John Midkiff
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, United States of America
| | - Nathan Borochoff-Porte
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, United States of America
| | - Dylan White
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, United States of America
| | - Douglas I. Johnson
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, United States of America
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Grald A, Yargosz P, Case S, Shea K, Johnson DI. Small-molecule inhibitors of biofilm formation in laboratory and clinical isolates of Candida albicans. J Med Microbiol 2011; 61:109-114. [PMID: 21903824 DOI: 10.1099/jmm.0.034124-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Candida albicans cells have the ability to form biofilms on biotic and abiotic surfaces, such as indwelling medical devices. C. albicans cells can interconvert between budded and hyphal growth forms, herein termed the budded-to-hyphal transition (BHT), which is important for the formation of mature biofilms. Previous work identified 23 small organic molecules that could inhibit the BHT but did not affect C. albicans cell viability or budded cell growth. These BHT inhibitors were proposed to inhibit multiple signalling pathways regulating the BHT, many of which also regulate biofilm formation. However, only three of the BHT inhibitors, buhytrinA, ETYA and CGP-37157, were capable of inhibiting in vitro biofilm formation of wild-type laboratory C. albicans strains. When clinical C. albicans isolates were examined for their ability to form biofilms, only 11 of the 28 clinical isolates tested (39%) were capable of forming biofilms. Although buhytrinA, ETYA and CGP-37157 could inhibit the BHT of all 28 clinical isolates, they were only able to inhibit biofilm formation of a subset of these clinical isolates, with ETYA having 100% efficacy. These data indicate that the biofilm-forming capability of laboratory and clinical isolates of C. albicans, as well as the efficacy of BHT inhibitors against these different isolates, can differ dramatically. These differences between laboratory and clinical isolates should be an important aspect to consider when examining potentially new antifungal therapeutics.
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Affiliation(s)
- Ariel Grald
- Department of Microbiology and Molecular Genetics, University of Vermont, 202 Stafford Hall, 95 Carrigan Drive, Burlington, VT 05405, USA
| | - Philip Yargosz
- Department of Microbiology and Molecular Genetics, University of Vermont, 202 Stafford Hall, 95 Carrigan Drive, Burlington, VT 05405, USA
| | - Samantha Case
- Department of Microbiology and Molecular Genetics, University of Vermont, 202 Stafford Hall, 95 Carrigan Drive, Burlington, VT 05405, USA
| | - Katelyn Shea
- Department of Microbiology and Molecular Genetics, University of Vermont, 202 Stafford Hall, 95 Carrigan Drive, Burlington, VT 05405, USA
| | - Douglas I Johnson
- Department of Microbiology and Molecular Genetics, University of Vermont, 202 Stafford Hall, 95 Carrigan Drive, Burlington, VT 05405, USA
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26
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Modulation of morphogenesis in Candida albicans by various small molecules. EUKARYOTIC CELL 2011; 10:1004-12. [PMID: 21642508 DOI: 10.1128/ec.05030-11] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The pathogenic yeast Candida albicans, a member of the mucosal microbiota, is responsible for a large spectrum of infections, ranging from benign thrush and vulvovaginitis in both healthy and immunocompromised individuals to severe, life-threatening infections in immunocompromised patients. A striking feature of C. albicans is its ability to grow as budding yeast and as filamentous forms, including hyphae and pseudohyphae. The yeast-to-hypha transition contributes to the overall virulence of C. albicans and may even constitute a target for the development of antifungal drugs. Indeed, impairing morphogenesis in C. albicans has been shown to be a means to treat candidiasis. Additionally, a large number of small molecules such as farnesol, fatty acids, rapamycin, geldanamycin, histone deacetylase inhibitors, and cell cycle inhibitors have been reported to modulate the yeast-to-hypha transition in C. albicans. In this minireview, we take a look at molecules that modulate morphogenesis in this pathogenic yeast. When possible, we address experimental findings regarding their mechanisms of action and their therapeutic potential. We discuss whether or not modulating morphogenesis constitutes a strategy to treat Candida infections.
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Identification of LY83583 as a specific inhibitor of Candida albicans MPS1 protein kinase. Biochem Biophys Res Commun 2011; 409:418-23. [PMID: 21586273 DOI: 10.1016/j.bbrc.2011.05.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 05/02/2011] [Indexed: 11/22/2022]
Abstract
Candida albicans is the most common and virulent fungus causing candidiasis in various parts of the body and can be lethal to immunocompromised patients. All currently known antifungal therapies are drugs which cause serious side effects in the host. An inhibitor specific for fungus survival is an ideal therapeutic. C. albicans MPS1 (monopolar spindle 1) has been reported as a kinase essential to its survival. Because CaMps1p shares limited sequence homology with the human ortholog (hMps1p), we screened for a chemical inhibitor in anticipation of finding one with Candida specific cytotoxicity. In vitro screening using a recombinant catalytic domain of CaMps1p identified LY83583 (6-anilino-5,8-quinolinedione), known as a guanylate cyclase inhibitor, to be blocking CaMps1p kinase activity. In addition to its in vitro kinase inhibition, LY83583 reduced the growth rate of C. albicans. Finally, we compared the inhibitory activity on CaMps1p and hMps1p among inhibitors against those kinases. LY83583 showed specific inhibition for CaMps1p with no effect on hMps1p activity. Conversely, the CaMps1p activity was not affected by known hMps1p inhibitors. These findings suggest that CaMps1p may well be an ideal target molecule for antifungal therapy.
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28
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Current awareness on yeast. Yeast 2009. [DOI: 10.1002/yea.1627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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