1
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Liang X, Pacuła-Miszewska AJ, Vartak R, Prajapati M, Zheng H, Zhao C, Mao G, Patel K, Fedosova NU, Ścianowski J, Billack B. N-3-Methylbutyl-benzisoselenazol-3(2H)-one Exerts Antifungal Activity In Vitro and in a Mouse Model of Vulvovaginal Candidiasis. Curr Issues Mol Biol 2024; 46:2480-2496. [PMID: 38534773 DOI: 10.3390/cimb46030157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 03/04/2024] [Accepted: 03/04/2024] [Indexed: 03/28/2024] Open
Abstract
In the present work, we evaluated the antifungal activities of two novel ebselen analogs, N-allyl-benzisoselenazol-3(2H)-one (N-allyl-bs) and N-3-methylbutylbenzisoselenazol-3(2H)-one (N-3mb-bs). Colorimetric and turbidity assays were performed to determine the minimum inhibitory concentration (MIC) of these compounds in S1 (fluconazole-sensitive) and S2 (fluconazole-resistant) strains of C. albicans. N-3mb-bs was more active than the N-allyl-bs compound. It is noteworthy that the concentration of N-3mb-bs observed to inhibit fungal growth by 50% (18.2 µM) was similar to the concentration observed to inhibit the activity of the yeast plasma membrane H+-ATPase (Pma1p) by 50% (19.6 µM). We next implemented a mouse model of vulvovaginal candidiasis (VVC) using the S1 strain and examined the mouse and yeast proteins present in the vaginal lavage fluid using proteomics. The yeast proteins detected were predominately glycolytic enzymes or virulence factors associated with C. albicans while the mouse proteins present in the lavage fluid included eosinophil peroxidase, desmocollin-1, and gasdermin-A. We then utilized the N-3mb-bs compound (12.5 mg/kg) in the mouse VVC model and observed that it significantly reduced the vaginal fungal burden, histopathological changes in vagina tissue, and expression of myeloperoxidase (MPO). All in all, the present work has identified a potentially promising drug candidate for VVC treatment.
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Affiliation(s)
- Xiuyi Liang
- Department of Pharmaceutical Sciences, St. John's University, Queens, NY 11439, USA
| | | | - Richa Vartak
- Department of Pharmaceutical Sciences, St. John's University, Queens, NY 11439, USA
| | - Milankumar Prajapati
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI 02912, USA
| | - Haiyan Zheng
- Center for Advanced Biotechnology and Medicine, Piscataway, NJ 08854, USA
| | - Caifeng Zhao
- Center for Advanced Biotechnology and Medicine, Piscataway, NJ 08854, USA
| | - Ganming Mao
- Department of Pharmaceutical Sciences, St. John's University, Queens, NY 11439, USA
| | - Ketankumar Patel
- Department of Pharmaceutical Sciences, St. John's University, Queens, NY 11439, USA
| | | | - Jacek Ścianowski
- Faculty of Chemistry, Nicolaus Copernicus University, 87-100 Toruń, Poland
| | - Blase Billack
- Department of Pharmaceutical Sciences, St. John's University, Queens, NY 11439, USA
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2
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Elgammal Y, Salama EA, Seleem MN. Saquinavir potentiates itraconazole's antifungal activity against multidrug-resistant Candida auris in vitro andin vivo. Med Mycol 2023; 61:myad081. [PMID: 37558393 DOI: 10.1093/mmy/myad081] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 07/20/2023] [Accepted: 08/08/2023] [Indexed: 08/11/2023] Open
Abstract
Candida species are highly opportunistic yeasts that are responsible for serious invasive fungal infections among immunocompromised patients worldwide. Due to the increase in drug resistance and incidence of infections, there is an urgent need to develop new antifungals and to identify co-drugs that can sensitize drug-resistant Candida to antifungals. The objective of this study was to assess the effect of saquinavir on the activity of azole antifungals against C. auris. The in vitro interaction of saquinavir and three azole antifungals (itraconazole, voriconazole, and fluconazole) was evaluated against a panel of C. auris isolates. The itraconazole/saquinavir combination exhibited a synergistic (SYN) relationship against all C. auris isolates tested with the fractional inhibitory concentration index ranging from 0.03 to 0.27. Moreover, a time-kill kinetics assay revealed that saquinavir restored the itraconazole's fungistatic activity against C. auris. Furthermore, saquinavir restored itraconazole's antifungal activity against other clinically important Candida species. The mechanistic investigation indicated that saquinavir significantly inhibited efflux pumps, glucose utilization, and ATP synthesis in Candida. Finally, a murine model of C. auris infection was used to evaluate the efficacy of the itraconazole/saquinavir combination in the presence of ritonavir (as a pharmacokinetic enhancer). The combination significantly reduced the fungal burden in the kidneys by 0.93-log10 colony-forming units (88%) compared to itraconazole alone. This study identified that saquinavir exhibits a potent SYN relationship in combination with itraconazole against Candida species, which warrants further consideration.
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Affiliation(s)
- Yehia Elgammal
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
- Center for One Health Research, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Ehab A Salama
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
- Center for One Health Research, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Mohamed N Seleem
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
- Center for One Health Research, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
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3
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Choy HL, Gaylord EA, Doering TL. Ergosterol distribution controls surface structure formation and fungal pathogenicity. mBio 2023; 14:e0135323. [PMID: 37409809 PMCID: PMC10470819 DOI: 10.1128/mbio.01353-23] [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: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 07/07/2023] Open
Abstract
Ergosterol, the major sterol in fungal membranes, is critical for defining membrane fluidity and regulating cellular processes. Although ergosterol synthesis has been well defined in model yeast, little is known about sterol organization in the context of fungal pathogenesis. We identified a retrograde sterol transporter, Ysp2, in the opportunistic fungal pathogen Cryptococcus neoformans. We found that the lack of Ysp2 under host-mimicking conditions leads to abnormal accumulation of ergosterol at the plasma membrane, invagination of the plasma membrane, and malformation of the cell wall, which can be functionally rescued by inhibiting ergosterol synthesis with the antifungal drug fluconazole. We also observed that cells lacking Ysp2 mislocalize the cell surface protein Pma1 and have abnormally thin and permeable capsules. As a result of perturbed ergosterol distribution and its consequences, ysp2∆ cells cannot survive in physiologically relevant environments such as host phagocytes and are dramatically attenuated in virulence. These findings expand our knowledge of cryptococcal biology and underscore the importance of sterol homeostasis in fungal pathogenesis. IMPORTANCE Cryptococcus neoformans is an opportunistic fungal pathogen that kills over 100,000 people worldwide each year. Only three drugs are available to treat cryptococcosis, and these are variously limited by toxicity, availability, cost, and resistance. Ergosterol is the most abundant sterol in fungi and a key component in modulating membrane behavior. Two of the drugs used for cryptococcal infection, amphotericin B and fluconazole, target this lipid and its synthesis, highlighting its importance as a therapeutic target. We discovered a cryptococcal ergosterol transporter, Ysp2, and demonstrated its key roles in multiple aspects of cryptococcal biology and pathogenesis. These studies demonstrate the role of ergosterol homeostasis in C. neoformans virulence, deepen our understanding of a pathway with proven therapeutic importance, and open a new area of study.
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Affiliation(s)
- Hau Lam Choy
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Elizabeth A. Gaylord
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Tamara L. Doering
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
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4
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Hoque E, Tran P, Jacobo U, Bergfeld N, Acharya S, Shamshina JL, Reid TW, Abidi N. Antimicrobial Coatings for Medical Textiles via Reactive Organo-Selenium Compounds. Molecules 2023; 28:6381. [PMID: 37687210 PMCID: PMC10490204 DOI: 10.3390/molecules28176381] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/24/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023] Open
Abstract
Bleached and cationized cotton fabrics were chemically modified with reactive organoselenium compounds through the nucleophilic aromatic substitution (SNAr) reaction, which allowed for organo-selenium attachment onto the surface of cotton fabrics via covalent bonds and, in the case of the cationized cotton fabric, additional ionic interactions. The resulting textiles exhibited potent bactericidal activity against S. aureus (99.99% reduction), although only moderate activity was observed against E. coli. Fabrics treated with reactive organo-selenium compounds also exhibited fungicidal activities against C. albicans, and much higher antifungal activity was observed when organo-selenium compounds were applied to the cationized cotton in comparison to the bleached cotton. The treatment was found to be durable against rigorous washing conditions (non-ionic detergent/100 °C). This paper is the first report on a novel approach integrating the reaction of cotton fabrics with an organo-selenium antimicrobial agent. This approach is attractive because it provides a method for imparting antimicrobial properties to cotton fabrics which does not disrupt the traditional production processes of a textile mill.
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Affiliation(s)
- Ejajul Hoque
- Fiber and Biopolymer Research Institute, Department of Plant and Soil Science, Texas Tech University, Lubbock, TX 79409, USA
| | - Phat Tran
- Department of Microbiology and Immunology, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Unique Jacobo
- Department of Microbiology and Immunology, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | | | - Sanjit Acharya
- Fiber and Biopolymer Research Institute, Department of Plant and Soil Science, Texas Tech University, Lubbock, TX 79409, USA
| | - Julia L. Shamshina
- Fiber and Biopolymer Research Institute, Department of Plant and Soil Science, Texas Tech University, Lubbock, TX 79409, USA
| | - Ted W. Reid
- Ophthalmology and Visual Sciences, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Noureddine Abidi
- Fiber and Biopolymer Research Institute, Department of Plant and Soil Science, Texas Tech University, Lubbock, TX 79409, USA
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5
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Choy HL, Gaylord EA, Doering TL. Ergosterol distribution controls surface structure formation and fungal pathogenicity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.17.528979. [PMID: 36824733 PMCID: PMC9949117 DOI: 10.1101/2023.02.17.528979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Ergosterol, the major sterol in fungal membranes, is critical for defining membrane fluidity and regulating cellular processes. Although ergosterol synthesis has been well defined in model yeast, little is known about sterol organization in the context of fungal pathogenesis. We identified a retrograde sterol transporter, Ysp2, in the opportunistic fungal pathogen Cryptococcus neoformans . We found that the lack of Ysp2 under host-mimicking conditions leads to abnormal accumulation of ergosterol at the plasma membrane, invagination of the plasma membrane, and malformation of the cell wall, which can be functionally rescued by inhibiting ergosterol synthesis with the antifungal drug fluconazole. We also observed that cells lacking Ysp2 mislocalize the cell surface protein Pma1 and have thinner and more permeable capsules. As a result of perturbed ergosterol distribution and its consequences, ysp2 Î" cells cannot survive in physiologically-rele-vant environments such as host phagocytes and are dramatically attenuated in virulence. These findings expand our knowledge of cryptococcal biology and underscore the importance of sterol homeostasis in fungal pathogenesis. IMPORTANCE Cryptococcus neoformans is an opportunistic fungal pathogen that kills over 100,000 people worldwide each year. Only three drugs are available to treat cryptococcosis, and these are variously limited by toxicity, availability, cost, and resistance. Ergosterol is the most abundant sterol in fungi and a key component in modulating membrane behavior. Two of the drugs used for cryptococcal infection, amphotericin B and fluconazole, target this lipid and its synthesis, highlighting its importance as a therapeutic target. We discovered a cryptococcal ergosterol transporter, Ysp2, and demonstrated its key roles in multiple aspects of cryptococcal biology and pathogenesis. These studies demonstrate the role of ergosterol homeostasis in C. neoformans virulence, deepen our understanding of a pathway with proven therapeutic importance, and open a new area of study.
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Affiliation(s)
- Hau Lam Choy
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Elizabeth A. Gaylord
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Tamara L. Doering
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
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6
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Tung TT, Nielsen J. Drug Discovery and Development on Pma1, Where Are We Now? A Critical Review from 1995 to 2022. ChemMedChem 2022; 17:e202200356. [PMID: 36094750 DOI: 10.1002/cmdc.202200356] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/31/2022] [Indexed: 11/09/2022]
Abstract
Plasma membrane H+ -ATPase (Pma1) is an enzyme uniquely found in plants and fungi. The enzyme controls the nutrient uptake of plants and fungi via an electrochemical gradient processes, which is essential for their survival. Inhibiting Pma1, therefore, constitutes an alternative antifungal target void of toxicity to humans. From a medicinal chemistry point of view, this review provides a first summary of the recent drug design, synthesis, evaluation, and discovery of molecules targeting Pma1 for 25 years from 1995 to 2022.
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Affiliation(s)
- Truong-Thanh Tung
- Faculty of Pharmacy, PHENIKAA University, Hanoi, 12116, Vietnam.,PHENIKAA Institute for Advanced Study (PIAS), PHENIKAA University, Hanoi, 12116, Vietnam
| | - John Nielsen
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100, Copenhagen Ø, Denmark
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7
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Menon S, Vartak R, Patel K, Billack B. Evaluation of the antifungal activity of an ebselen-loaded nanoemulsion in a mouse model of vulvovaginal candidiasis. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2021; 37:102428. [PMID: 34217850 DOI: 10.1016/j.nano.2021.102428] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 04/01/2021] [Accepted: 05/03/2021] [Indexed: 12/20/2022]
Abstract
Vulvovaginal candidiasis (VVC), caused by Candida albicans, is a common infection in women affecting their quality of life. Standard antifungal drugs (e.g., fluconazole, itraconazole) are typically fungistatic or rendered ineffective due to drug resistance indicating an urgent need to build an arsenal of novel antifungal agents. To surmount this issue, we tested the hypothesis that the organoselenium compound ebselen (EB) possesses antifungal efficacy in a mouse model of VVC. EB is a poorly water-soluble drug and DMSO as a vehicle has the potential to exhibit cytotoxic effects when administered in vivo. EB loaded self-nanoemulsifying preconcentrate (EB-SNEP) was developed, characterized in vitro, and tested in a mouse model of VVC. In vivo studies carried out with EB-SNEP (12.5 mg/kg) showed a remarkable decrease in infection by ~562-fold compared to control (infected, untreated animals). Taken together, EB nanoemulsion proved to be an effective and promising antifungal agent.
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Affiliation(s)
- Suvidha Menon
- Department of Pharmaceutical Sciences, St. John's University, Queens, Jamaica, NY, USA
| | - Richa Vartak
- Department of Pharmaceutical Sciences, St. John's University, Queens, Jamaica, NY, USA
| | - Ketankumar Patel
- Department of Pharmaceutical Sciences, St. John's University, Queens, Jamaica, NY, USA.
| | - Blase Billack
- Department of Pharmaceutical Sciences, St. John's University, Queens, Jamaica, NY, USA.
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8
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Song J, Liu X, Li R. Sphingolipids: Regulators of azole drug resistance and fungal pathogenicity. Mol Microbiol 2020; 114:891-905. [PMID: 32767804 DOI: 10.1111/mmi.14586] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 07/29/2020] [Accepted: 08/02/2020] [Indexed: 12/14/2022]
Abstract
In recent years, the role of sphingolipids in pathogenic fungi, in terms of pathogenicity and resistance to azole drugs, has been a rapidly growing field. This review describes evidence about the roles of sphingolipids in azole resistance and fungal virulence. Sphingolipids can serve as signaling molecules that contribute to azole resistance through modulation of the expression of drug efflux pumps. They also contribute to azole resistance by participating in various microbial pathways such as the unfolded protein response (UPR), pH-responsive Rim pathway, and pleiotropic drug resistance (PDR) pathway. In addition, sphingolipid signaling and eisosomes also coordinately regulate sphingolipid biosynthesis in response to azole-induced membrane stress. Sphingolipids are important for fungal virulence, playing roles during growth in hosts under stressful conditions, maintenance of cell wall integrity, biofilm formation, and production of various virulence factors. Finally, we discuss the possibility of exploiting fungal sphingolipids for the development of new therapeutic strategies to treat infections caused by pathogenic fungi.
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Affiliation(s)
- Jinxing Song
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province and School of Life Science, Jiangsu Normal University, Xuzhou, PR China
| | - Xiao Liu
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province and School of Life Science, Jiangsu Normal University, Xuzhou, PR China
| | - Rongpeng Li
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province and School of Life Science, Jiangsu Normal University, Xuzhou, PR China
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9
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Tang L, Mo J, Guo T, Huang S, Li Q, Ning P, Hsiang T. In vitro antifungal activity of dimethyl trisulfide against Colletotrichum gloeosporioides from mango. World J Microbiol Biotechnol 2019; 36:4. [PMID: 31832786 DOI: 10.1007/s11274-019-2781-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 12/01/2019] [Indexed: 02/02/2023]
Abstract
Colletotrichum gloeosporioides, one of the main agents of mango anthracnose, causes latent infections in unripe mango, and leads to huge economic losses during storage and transport. Dimethyl trisulfide (DMTS), one of the main volatile compounds produced by some microorganisms or plants, has shown antifungal activity against some phytopathogens in previous studies, but its effects on C. gloeosporioides and mechanisms of action have not been well characterized. In fumigation trials of conidia and mycelia of C. gloeosporioides for 2, 4, 6, 8, or 10 h, at a concentration of 100 μL/L of air space in vitro, DMTS caused serious damage to the integrity of plasma membranes, which significantly reduced the survival rate of spores, and resulted in abnormal hyphal morphology. Moreover, DMTS caused deterioration of subcellular structures of conidia and mycelia, such as cell walls, plasma membranes, Golgi bodies, and mitochondria, and contributed to leakage of protoplasm, thus promoting vacuole formation. In addition, to better understand the molecular mechanisms of the antifungal activity, the global gene expression profiles of isolate C. gloeosporioides TD3 treated in vitro with DMTS at a concentration of 100 μL/L of air for 0 h (Control), 1 h, or 3 h were investigated by RNA sequencing (RNA-seq), and over 62 Gb clean reads were generated from nine samples. Similar expressional patterns for nine differentially expressed genes (DEGs) in both RNA-seq and qRT-PCR assays showed the reliability of the RNA-seq data. In comparison to the non-treated control groups, we found DMTS suppressed expression of β-1, 3-D-glucan, chitin, sterol biosynthesis-related genes, and membrane protein-related genes. These genes related to the formation of fungal cell walls and plasma membranes might be associated with the toxicity of DMTS against C. gloeosporioides. This is the first study demonstrating antifungal activity of DMTS against C. gloeosporioides on mango by direct damage of conidia and hyphae, thus providing a novel tool for postharvest control of mango anthracnose.
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Affiliation(s)
- Lihua Tang
- Institute of Plant Protection, Guangxi Academy of Agricultural Sciences, Nanning, 530007, Guangxi, China.,The Key Lab for Biology of Crop Diseases and Insect Pests of Guangxi, Nanning, 530007, Guangxi, China
| | - Jianyou Mo
- Institute of Plant Protection, Guangxi Academy of Agricultural Sciences, Nanning, 530007, Guangxi, China.,The Key Lab for Biology of Crop Diseases and Insect Pests of Guangxi, Nanning, 530007, Guangxi, China
| | - Tangxun Guo
- Institute of Plant Protection, Guangxi Academy of Agricultural Sciences, Nanning, 530007, Guangxi, China.,The Key Lab for Biology of Crop Diseases and Insect Pests of Guangxi, Nanning, 530007, Guangxi, China
| | - Suiping Huang
- Institute of Plant Protection, Guangxi Academy of Agricultural Sciences, Nanning, 530007, Guangxi, China.,The Key Lab for Biology of Crop Diseases and Insect Pests of Guangxi, Nanning, 530007, Guangxi, China
| | - Qili Li
- Institute of Plant Protection, Guangxi Academy of Agricultural Sciences, Nanning, 530007, Guangxi, China. .,The Key Lab for Biology of Crop Diseases and Insect Pests of Guangxi, Nanning, 530007, Guangxi, China.
| | - Ping Ning
- Guangxi Agricultural Vocational College, Nanning, 530007, Guangxi, China
| | - Tom Hsiang
- School of Environmental Sciences, University of Guelph, Guelph, ON, N1G 2W1, Canada
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10
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Rossato L, Loreto ES, Venturini TP, Azevedo MI, Al‐Hatmi AMS, Santurio JM, Alves SH. In vitro combination between antifungals and diphenyl diselenide against
Cryptococcus
species. Mycoses 2019; 62:508-512. [DOI: 10.1111/myc.12905] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 01/30/2019] [Accepted: 01/31/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Luana Rossato
- Postgraduate Program in Pharmaceutical SciencesHealth Sciences CentreFederal University of Santa Maria (UFSM) Santa Maria Rio Grande do Sul Brazil
| | - Erico S. Loreto
- Postgraduate Program in Pharmaceutical SciencesHealth Sciences CentreFederal University of Santa Maria (UFSM) Santa Maria Rio Grande do Sul Brazil
- Faculty of Health SciencesSobresp Santa Maria Rio Grande do Sul Brazil
| | - Tarcieli P. Venturini
- Postgraduate Program in Pharmaceutical SciencesHealth Sciences CentreFederal University of Santa Maria (UFSM) Santa Maria Rio Grande do Sul Brazil
| | - Maria Isabel Azevedo
- Department of Preventive Veterinary MedicineFederal University of Minas Gerais (UFMG) Belo Horizonte Minas Gerais Brazil
| | - Abdullah M. S. Al‐Hatmi
- Westerdijk Fungal Biodiversity Institute Utrecht The Netherlands
- Ministry of HealthDirectorate General of Health Services Ibri Oman
- Centre of Expertise in MycologyRadboud University Medical Centre/Canisius Wilhelmina Hospital Nijmegen The Netherlands
| | - Janio M. Santurio
- Postgraduate Program in PharmacologyHealth Sciences CentreFederal University of Santa Maria (UFSM) Santa Maria Rio Grande do Sul Brazil
| | - Sydney H. Alves
- Postgraduate Program in Pharmaceutical SciencesHealth Sciences CentreFederal University of Santa Maria (UFSM) Santa Maria Rio Grande do Sul Brazil
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11
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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.
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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
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12
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Munshi MA, Gardin JM, Singh A, Luberto C, Rieger R, Bouklas T, Fries BC, Del Poeta M. The Role of Ceramide Synthases in the Pathogenicity of Cryptococcus neoformans. Cell Rep 2018; 22:1392-1400. [PMID: 29425496 PMCID: PMC5839121 DOI: 10.1016/j.celrep.2018.01.035] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 12/02/2017] [Accepted: 01/11/2018] [Indexed: 11/22/2022] Open
Abstract
Cryptococcus neoformans (C. neoformans) is estimated to cause about 220,000 new cases every year in patients with AIDS, despite advances in antifungal treatments. C. neoformans possesses a remarkable ability to disseminate through an immunocompromised host, making treatment difficult. Here, we examine the mechanism of survival of C. neoformans under varying host conditions and find a role for ceramide synthase in C. neoformans virulence. This study also provides a detailed lipidomics resource for the fungal lipid research community in addition to discovering a potential target for antifungal therapy.
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Affiliation(s)
- Mansa A Munshi
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794, USA
| | | | - Ashutosh Singh
- Department of Biochemistry, University of Lucknow, Lucknow, Uttar Pradesh 226007, India
| | - Chiara Luberto
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY 11794, USA
| | - Robert Rieger
- Proteomics Center, Stony Brook University, Stony Brook, NY 11794, USA
| | - Tejas Bouklas
- Department of Biomedical Sciences, School of Health Professions and Nursing, Long Island University, Brookville, NY 11548, USA
| | - Bettina C Fries
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794, USA; Division of Infectious Diseases, School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
| | - Maurizio Del Poeta
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794, USA; Division of Infectious Diseases, School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA; Veterans Administration Medical Center, Northport, NY 11768, USA.
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Orie NN, Warren AR, Basaric J, Lau-Cam C, Piętka-Ottlik M, Młochowski J, Billack B. In vitroassessment of the growth and plasma membrane H+-ATPase inhibitory activity of ebselen and structurally related selenium- and sulfur-containing compounds inCandida albicans. J Biochem Mol Toxicol 2017; 31. [DOI: 10.1002/jbt.21892] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 12/06/2016] [Accepted: 12/16/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Natalie N. Orie
- Department of Pharmaceutical Sciences; St. John's University; Jamaica NY USA
| | - Andrew R. Warren
- Department of Pharmaceutical Sciences; St. John's University; Jamaica NY USA
| | - Jovana Basaric
- Department of Pharmaceutical Sciences; St. John's University; Jamaica NY USA
| | - Cesar Lau-Cam
- Department of Pharmaceutical Sciences; St. John's University; Jamaica NY USA
| | - Magdalena Piętka-Ottlik
- Division of Organic and Pharmaceutical Technology, Faculty of Chemistry; Wrocław University of Technology; Wrocław Poland
| | - Jacek Młochowski
- Department of Organic Chemistry, Faculty of Chemistry; Wrocław University of Technology; Wrocław Poland
| | - Blase Billack
- Department of Pharmaceutical Sciences; St. John's University; Jamaica NY USA
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The Celecoxib Derivative AR-12 Has Broad-Spectrum Antifungal Activity In Vitro and Improves the Activity of Fluconazole in a Murine Model of Cryptococcosis. Antimicrob Agents Chemother 2016; 60:7115-7127. [PMID: 27645246 DOI: 10.1128/aac.01061-16] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 09/04/2016] [Indexed: 12/24/2022] Open
Abstract
Only one new class of antifungal drugs has been introduced into clinical practice in the last 30 years, and thus the identification of small molecules with novel mechanisms of action is an important goal of current anti-infective research. Here, we describe the characterization of the spectrum of in vitro activity and in vivo activity of AR-12, a celecoxib derivative which has been tested in a phase I clinical trial as an anticancer agent. AR-12 inhibits fungal acetyl coenzyme A (acetyl-CoA) synthetase in vitro and is fungicidal at concentrations similar to those achieved in human plasma. AR-12 has a broad spectrum of activity, including activity against yeasts (e.g., Candida albicans, non-albicans Candida spp., Cryptococcus neoformans), molds (e.g., Fusarium, Mucor), and dimorphic fungi (Blastomyces, Histoplasma, and Coccidioides) with MICs of 2 to 4 μg/ml. AR-12 is also active against azole- and echinocandin-resistant Candida isolates, and subinhibitory AR-12 concentrations increase the susceptibility of fluconazole- and echinocandin-resistant Candida isolates. Finally, AR-12 also increases the activity of fluconazole in a murine model of cryptococcosis. Taken together, these data indicate that AR-12 represents a promising class of small molecules with broad-spectrum antifungal activity.
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Dao TT, Sehgal P, Tung TT, Møller JV, Nielsen J, Palmgren M, Christensen SB, Fuglsang AT. Demethoxycurcumin Is A Potent Inhibitor of P-Type ATPases from Diverse Kingdoms of Life. PLoS One 2016; 11:e0163260. [PMID: 27644036 PMCID: PMC5028038 DOI: 10.1371/journal.pone.0163260] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 09/05/2016] [Indexed: 12/25/2022] Open
Abstract
P-type ATPases catalyze the active transport of cations and phospholipids across biological membranes. Members of this large family are involved in a range of fundamental cellular processes. To date, a substantial number of P-type ATPase inhibitors have been characterized, some of which are used as drugs. In this work a library of natural compounds was screened and we first identified curcuminoids as plasma membrane H+-ATPases inhibitors in plant and fungal cells. We also found that some of the commercial curcumins contain several curcuminoids. Three of these were purified and, among the curcuminoids, demethoxycurcumin was the most potent inhibitor of all tested P-type ATPases from fungal (Pma1p; H+-ATPase), plant (AHA2; H+-ATPase) and animal (SERCA; Ca2+-ATPase) cells. All three curcuminoids acted as non-competitive antagonist to ATP and hence may bind to a highly conserved allosteric site of these pumps. Future research on biological effects of commercial preparations of curcumin should consider the heterogeneity of the material.
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Affiliation(s)
- Trong Tuan Dao
- Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Pankaj Sehgal
- Department of Biomedicine, University of Aarhus, Aarhus, Denmark
| | - Truong Thanh Tung
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | | | - John Nielsen
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Michael Palmgren
- Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Anja Thoe Fuglsang
- Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
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Andrés MT, Acosta-Zaldívar M, Fierro JF. Antifungal Mechanism of Action of Lactoferrin: Identification of H+-ATPase (P3A-Type) as a New Apoptotic-Cell Membrane Receptor. Antimicrob Agents Chemother 2016; 60:4206-16. [PMID: 27139463 PMCID: PMC4914641 DOI: 10.1128/aac.03130-15] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 04/27/2016] [Indexed: 11/20/2022] Open
Abstract
Human lactoferrin (hLf) is a protein of the innate immune system which induces an apoptotic-like process in yeast. Determination of the susceptibility to lactoferrin of several yeast species under different metabolic conditions, respiratory activity, cytoplasmic ATP levels, and external medium acidification mediated by glucose assays suggested plasma membrane Pma1p (P3A-type ATPase) as the hLf molecular target. The inhibition of plasma membrane ATPase activity by hLf and the identification of Pma1p as the hLf-binding membrane protein confirmed the previous physiological evidence. Consistent with this, cytoplasmic ATP levels progressively increased in hLf-treated Candida albicans cells. However, oligomycin, a specific inhibitor of the mitochondrial F-type ATPase proton pump (mtATPase), abrogated the antifungal activity of hLf, indicating a crucial role for mtATPase in the apoptotic process. We suggest that lactoferrin targeted plasma membrane Pma1p H(+)-ATPase, perturbing the cytoplasmic ion homeostasis (i.e., cytoplasmic H(+) accumulation and subsequent K(+) efflux) and inducing a lethal mitochondrial dysfunction. This initial event involved a normal mitochondrial ATP synthase activity responsible for both the ATP increment and subsequent hypothetical mitochondrial proton flooding process. We conclude that human lactoferrin inhibited Pma1p H(+)-ATPase, inducing an apoptotic-like process in metabolically active yeast. Involvement of mitochondrial H(+)-ATPase (nonreverted) was essential for the progress of this programmed cell death in which the ionic homeostasis perturbation seems to precede classical nonionic apoptotic events.
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Affiliation(s)
- María T Andrés
- Laboratory of Oral Microbiology, School of Stomatology, Faculty of Medicine, University of Oviedo, Oviedo, Spain
| | - Maikel Acosta-Zaldívar
- Laboratory of Oral Microbiology, School of Stomatology, Faculty of Medicine, University of Oviedo, Oviedo, Spain Department of Functional Biology (Microbiology), Faculty of Medicine, University of Oviedo, Oviedo, Spain
| | - José F Fierro
- Laboratory of Oral Microbiology, School of Stomatology, Faculty of Medicine, University of Oviedo, Oviedo, Spain Department of Functional Biology (Microbiology), Faculty of Medicine, University of Oviedo, Oviedo, Spain
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17
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Venturini TP, Chassot F, Loreto ÉS, Keller JT, Azevedo MI, Zeni G, Santurio JM, Alves SH. Antifungal activities of diphenyl diselenide and ebselen alone and in combination with antifungal agents againstFusariumspp. Med Mycol 2016; 54:550-5. [DOI: 10.1093/mmy/myv120] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 12/18/2015] [Indexed: 01/17/2023] Open
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18
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Kongstad KT, Wubshet SG, Kjellerup L, Winther AML, Staerk D. Fungal plasma membrane H⁺-ATPase inhibitory activity of o-hydroxybenzylated flavanones and chalcones from Uvaria chamae P. Beauv. Fitoterapia 2015; 105:102-6. [PMID: 26102180 DOI: 10.1016/j.fitote.2015.06.013] [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: 05/07/2015] [Revised: 06/12/2015] [Accepted: 06/13/2015] [Indexed: 10/23/2022]
Abstract
In our ongoing efforts of finding natural fungicides to fight food and feed spoilage during production and storage, the antifungal potential of Ghanaian Uvaria chamae P. Beauv. was investigated, with emphasis on plant metabolites targeting the fungal plasma membrane (PM) H(+)-ATPase. Ethyl acetate extract of U. chamae was subjected to high-resolution fungal PM H(+)-ATPase inhibition screening followed by structural elucidation by high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance spectroscopy (HPLC-HRMS-SPE-NMR). This led to identification of a series of uncommon o-hydroxybenzylated flavanones and chalcones, i.e., chamanetin (8), isochamanetin (9), isouvaretin (10), uvaretin (11), dichamanetin (12), and diuvaretin (15). Preparative-scale isolation of the active metabolites allowed determination of IC50 values for inhibition of the PM H(+)-ATPase, and growth inhibition of Saccharomyces cerevisiae and Candida albicans. These revealed a strong correlation between o-hydroxybenzyl substituents and PM H(+)-ATPase activity, with dichamanetin being the most potent compound, but showing moderate activity in the fungal growth inhibition assays.
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Affiliation(s)
- Kenneth T Kongstad
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
| | - Sileshi G Wubshet
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | | | | | - Dan Staerk
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
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Chu J, Li WF, Cheng W, Lu M, Zhou KH, Zhu HQ, Li FG, Zhou CZ. Comparative analyses of secreted proteins from the phytopathogenic fungus Verticillium dahliae in response to nitrogen starvation. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:437-48. [PMID: 25698221 DOI: 10.1016/j.bbapap.2015.02.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 02/06/2015] [Accepted: 02/09/2015] [Indexed: 01/04/2023]
Abstract
The soilborne fungus Verticillium dahliae is the major pathogen that causes the verticillium wilt disease of plants, which leads to huge economic loss worldwide. At the early stage of infection, growth of the pathogen is subject to the nutrition stress of limited nitrogen. To investigate the secreted pathogenic proteins that play indispensable roles during invasion at this stage, we compared the profiles of secreted proteins of V. dahliae under nitrogen starvation and normal conditions by using in-gel and in-solution digestion combined with liquid chromatography-nano-electrospray ionization tandem mass spectrometry (LC-nanoESI-MS). In total, we identified 212 proteins from the supernatant of liquid medium, including 109 putative secreted proteins. Comparative analysis indicated that the expression of 76 proteins was induced, whereas that of 9 proteins was suppressed under nitrogen starvation. Notably, 24 proteins are constitutively expressed. Further bioinformatic exploration enabled us to classify the stress-induced proteins into seven functional groups: cell wall degradation (10.5%), reactive oxygen species (ROS) scavenging and stress response (11.8%), lipid effectors (5.3%), protein metabolism (21.1%), carbohydrate metabolism (15.8%), electron-proton transport and energy metabolism (14.5%), and other (21.0%). In addition, most stress-suppressed proteins are involved in the cell-wall remodeling. Taken together, our analyses provide insights into the pathogenesis of V. dahliae and might give hints for the development of novel strategy against the verticillium wilt disease.
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Affiliation(s)
- Jun Chu
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China
| | - Wei-Fang Li
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China
| | - Wang Cheng
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China
| | - Mo Lu
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China
| | - Ke-Hai Zhou
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agriculture Sciences (CAAS), Anyang, Henan 455000, People's Republic of China
| | - He-Qin Zhu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agriculture Sciences (CAAS), Anyang, Henan 455000, People's Republic of China
| | - Fu-Guang Li
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agriculture Sciences (CAAS), Anyang, Henan 455000, People's Republic of China.
| | - Cong-Zhao Zhou
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China.
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20
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Farnoud AM, Mor V, Singh A, Del Poeta M. Inositol phosphosphingolipid phospholipase C1 regulates plasma membrane ATPase (Pma1) stability in Cryptococcus neoformans. FEBS Lett 2014; 588:3932-8. [PMID: 25240197 PMCID: PMC4254033 DOI: 10.1016/j.febslet.2014.09.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 09/03/2014] [Accepted: 09/06/2014] [Indexed: 11/24/2022]
Abstract
Cryptococcus neoformans is a facultative intracellular pathogen, which can replicate in the acidic environment inside phagolysosomes. Deletion of the enzyme inositol-phosphosphingolipid-phospholipase-C (Isc1) makes C. neoformans hypersensitive to acidic pH likely by inhibiting the function of the proton pump, plasma membrane ATPase (Pma1). In this work, we examined the role of Isc1 on Pma1 transport and oligomerization. Our studies showed that Isc1 deletion did not affect Pma1 synthesis or transport, but significantly inhibited Pma1 oligomerization. Interestingly, Pma1 oligomerization could be restored by supplementing the medium with phytoceramide. These results offer insight into the mechanism of intracellular survival of C. neoformans.
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Affiliation(s)
- Amir M Farnoud
- Department of Molecular Genetics and Microbiology, Stony Brook University, 145 Life Sciences Building, Stony Brook, NY 11794, USA
| | - Visesato Mor
- Department of Molecular Genetics and Microbiology, Stony Brook University, 145 Life Sciences Building, Stony Brook, NY 11794, USA
| | - Ashutosh Singh
- Department of Molecular Genetics and Microbiology, Stony Brook University, 145 Life Sciences Building, Stony Brook, NY 11794, USA
| | - Maurizio Del Poeta
- Department of Molecular Genetics and Microbiology, Stony Brook University, 145 Life Sciences Building, Stony Brook, NY 11794, USA.
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21
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Kongstad KT, Wubshet SG, Johannesen A, Kjellerup L, Winther AML, Jäger AK, Staerk D. High-resolution screening combined with HPLC-HRMS-SPE-NMR for identification of fungal plasma membrane H(+)-ATPase inhibitors from plants. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:5595-5602. [PMID: 24830509 DOI: 10.1021/jf501605z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Crude extracts of 33 plant species were assessed for fungal plasma membrane (PM) H(+)-ATPase inhibition. This led to identification of 18 extracts showing more than 95% inhibition at a concentration of 7.5 mg/mL and/or a concentration-dependent activity profile. These extracts were selected for semi-high-resolution fungal PM H(+)-ATPase inhibition screening, and, on the basis of these results, Haplocoelum foliolosum (Hiern) Bullock and Sauvagesia erecta L. were selected for investigation by high-resolution fungal PM H(+)-ATPase inhibition screening. Structural analysis performed by high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance spectroscopy (HPLC-HRMS-SPE-NMR) led to identification of chebulagic acid (1) and tellimagrandin II (2) from H. foliolosum. Preparative-scale isolation of the two metabolites allowed determination of IC50 values for PM H(+)-ATPase, and growth inhibition of Saccharomyces cerevisiae and Candida albicans. Chebulagic acid and tellimagrandin II are both potent inhibitors of the PM H(+)-ATPase with inhibitory effect on the growth of S. cerevisiae.
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Affiliation(s)
- Kenneth T Kongstad
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , Universitetsparken 2, DK-2100 Copenhagen, Denmark
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22
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Hayek SR, Lee SA, Parra KJ. Advances in targeting the vacuolar proton-translocating ATPase (V-ATPase) for anti-fungal therapy. Front Pharmacol 2014; 5:4. [PMID: 24478704 PMCID: PMC3902353 DOI: 10.3389/fphar.2014.00004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Accepted: 01/06/2014] [Indexed: 11/13/2022] Open
Abstract
Vacuolar proton-translocating ATPase (V-ATPase) is a membrane-bound, multi-subunit enzyme that uses the energy of ATP hydrolysis to pump protons across membranes. V-ATPase activity is critical for pH homeostasis and organelle acidification as well as for generation of the membrane potential that drives secondary transporters and cellular metabolism. V-ATPase is highly conserved across species and is best characterized in the model fungus Saccharomyces cerevisiae. However, recent studies in mammals have identified significant alterations from fungi, particularly in the isoform composition of the 14 subunits and in the regulation of complex disassembly. These differences could be exploited for selectivity between fungi and humans and highlight the potential for V-ATPase as an anti-fungal drug target. Candida albicans is a major human fungal pathogen and causes fatality in 35% of systemic infections, even with anti-fungal treatment. The pathogenicity of C. albicans correlates with environmental, vacuolar, and cytoplasmic pH regulation, and V-ATPase appears to play a fundamental role in each of these processes. Genetic loss of V-ATPase in pathogenic fungi leads to defective virulence, and a comprehensive picture of the mechanisms involved is emerging. Recent studies have explored the practical utility of V-ATPase as an anti-fungal drug target in C. albicans, including pharmacological inhibition, azole therapy, and targeting of downstream pathways. This overview will discuss these studies as well as hypothetical ways to target V-ATPase and novel high-throughput methods for use in future drug discovery screens.
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Affiliation(s)
- Summer R Hayek
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center Albuquerque, NM, USA
| | - Samuel A Lee
- Department of Internal Medicine, School of Medicine, University of New Mexico Health Sciences Center Albuquerque, NM, USA ; Section of Infectious Diseases, New Mexico Veterans Healthcare System Albuquerque, NM, USA
| | - Karlett J Parra
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center Albuquerque, NM, USA
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Ullah A, Lopes MI, Brul S, Smits GJ. Intracellular pH homeostasis in Candida glabrata in infection-associated conditions. Microbiology (Reading) 2013; 159:803-813. [DOI: 10.1099/mic.0.063610-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Affiliation(s)
- Azmat Ullah
- Department of Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, The Netherlands
| | - Maria Inês Lopes
- Department of Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, The Netherlands
| | - Stanley Brul
- Department of Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, The Netherlands
| | - Gertien J. Smits
- Department of Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, The Netherlands
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24
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Florio AR, Ferrari S, De Carolis E, Torelli R, Fadda G, Sanguinetti M, Sanglard D, Posteraro B. Genome-wide expression profiling of the response to short-term exposure to fluconazole in Cryptococcus neoformans serotype A. BMC Microbiol 2011; 11:97. [PMID: 21569340 PMCID: PMC3119188 DOI: 10.1186/1471-2180-11-97] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Accepted: 05/11/2011] [Indexed: 12/31/2022] Open
Abstract
Background Fluconazole (FLC), a triazole antifungal drug, is widely used for the maintenance therapy of cryptococcal meningoencephalitis, the most common opportunistic infection in AIDS patients. In this study, we examined changes in the gene expression profile of the C. neoformans reference strain H99 (serotype A) following FLC treatment in order to investigate the adaptive cellular responses to drug stress. Results Simultaneous analysis of over 6823 transcripts revealed that 476 genes were responsive to FLC. As expected up-regulation of genes involved in ergosterol biosynthesis was observed, including the azole target gene ERG11 and ERG13, ERG1, ERG7, ERG25, ERG2, ERG3 and ERG5. In addition, SRE1 which is a gene encoding a well-known regulator of sterol homeostasis in C. neoformans was up-regulated. Several other genes such as those involved in a variety of important cellular processes (i.e. lipid and fatty acid metabolism, cell wall maintenance, stress and virulence) were found to be up-regulated in response to FLC treatment. Conversely, expression of AFR1, the major transporter of azoles in C. neoformans, was not regulated by FLC. Conclusions Short-term exposure of C. neoformans to FLC resulted in a complex altered gene expression profile. Some of the observed changes could represent specific adaptive responses to the antifungal agent in this pathogenic yeast.
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Affiliation(s)
- Ada Rita Florio
- Istituto di Microbiologia, Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168 Rome, Italy
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25
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Hood JR, Burton DM, Wilkinson JM, Cavanagh HMA. The effect of Leptospermum petersonii essential oil on Candida albicans and Aspergillus fumigatus. Med Mycol 2011; 48:922-31. [PMID: 20446888 DOI: 10.3109/13693781003774697] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A variety of assays were utilized to determine the effects of Leptospermum petersonii essential oil on both Candida albicans and Aspergillus fumigatus. Hyphal morphology, susceptibility of spheroplasts and uptake of propidium iodide following exposure to the oil suggest that the mode of action of L. petersonii essential oil is through direct disturbance of the fungal cell membrane. Data also confirms that the volatile component of the oil is highly antifungal, independent of direct contact between the liquid oil and the fungal membrane. The degree of inhibition was greater when fungi were directly exposed to oil volatiles compared to pre-inoculation exposure of oil volatiles into the agar. It is likely that the essential oil volatiles are acting both directly and indirectly on the fungi to produce growth inhibition.
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Affiliation(s)
- J R Hood
- Surveillance Branch, Office of Health Protection, Department of Health and Ageing, Canberra, Australia
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26
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Regulation of Saccharomyces cerevisiae Plasma membrane H(+)-ATPase (Pma1) by Dextrose and Hsp30 during Exposure to Thermal Stress. Indian J Microbiol 2011; 51:153-8. [PMID: 22654157 DOI: 10.1007/s12088-011-0137-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Accepted: 10/22/2010] [Indexed: 12/30/2022] Open
Abstract
Pma1p is an essential plasma membrane H(+)-pump in Saccharomyces cerevisiae that pumps out H(+) at the expense of cellular ATP. Its activity is induced by glucose at 30°C and is inhibited by Hsp30 during exposure to heat shock conditions. To further investigate the regulation of Pma1 function by glucose and Hsp30 during exposure to thermal stress, we estimated Pma1 activity, its protein levels and ser-phosphorylation status in membrane fractions isolated from BY4741 and hsp30Δ cells grown in dextrose and sorbitol at 30°C, and following exposure at 40°C for 30 min. Our results demonstrate that Pma1 activity and protein levels were reduced in Hsp30(+) cells following exposure to thermal stress in dextrose media. The above was not observed in hsp30Δ cells wherein Pma1 activity did not decrease following exposure to similar conditions. Although Pma1p levels decreased in heat-shocked hsp30Δ cells, it was lower compared to that observed in Hsp30(+) cells. Total ser-phosphorylation of Pma1 also showed a decrease following exposure to heat shock condition in dextrose media in both BY4741 and hsp30Δ cells. Its levels were also reduced in BY4741 cells upon heat shock treatment in sorbitol unlike that observed in hsp30Δ cells wherein it was increased. Taken together the above indicate that heat shock induced reduction in Pma1 activity and protein levels in dextrose media required Hsp30. To examine functional interactions between dextrose utilization, Hsp30 and the regulation of various aspects of Pma1, we determined if dextrose regulated other functions attributed to Hsp30. Results demonstrate that the deletion of HSP30 rendered cells dependent on dextrose utilization for survival during exposure to lethal heat stress. Our study has hence been able to establish a functional relationship between glucose utilization, Hsp30 function and the regulation of Pma1 activity. Finally, since the deletion of HSP30 renders Pma1p levels and its activity unresponsive to thermal stress in dextrose media, we concluded that Hsp30 is necessary to maintain Pma1 in a regulation competent conformation. Hsp30 may thus act as a chaperone in the S. cerevisiae plasma membrane.
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27
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Ebselen is a potent non-competitive inhibitor of extracellular nucleoside diphosphokinase. Purinergic Signal 2010; 6:383-91. [PMID: 21437009 DOI: 10.1007/s11302-010-9203-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Accepted: 10/18/2010] [Indexed: 12/12/2022] Open
Abstract
Nucleoside di- and triphosphates and adenosine regulate several components of the mucocilairy clearance process (MCC) that protects the lung against infections, via activation of epithelial purinergic receptors. However, assessing the contribution of individual nucleotides to MCC functions remains difficult due to the complexity of the mechanisms of nucleotide release and metabolism. Enzymatic activities involved in the metabolism of extracellular nucleotides include ecto-ATPases and secreted nucleoside diphosphokinase (NDPK) and adenyl kinase, but potent and selective inhibitors of these activities are sparse. In the present study, we discovered that ebselen markedly reduced NDPK activity while having negligible effect on ecto-ATPase and adenyl kinase activities. Addition of radiotracer [γ(32)P]ATP to human bronchial epithelial (HBE) cells resulted in rapid and robust accumulation of [(32)P]-inorganic phosphate ((32)Pi). Inclusion of UDP in the incubation medium resulted in conversion of [γ(32)P]ATP to [(32)P]UTP, while inclusion of AMP resulted in conversion of [γ(32)P]ATP to [(32)P]ADP. Ebselen markedly reduced [(32)P]UTP formation but displayed negligible effect on (32)Pi or [(32)P]ADP accumulations. Incubation of HBE cells with unlabeled UTP and ADP resulted in robust ebselen-sensitive formation of ATP (IC(50) = 6.9 ± 2 μM). This NDPK activity was largely recovered in HBE cell secretions and supernatants from lung epithelial A549 cells. Kinetic analysis of NDPK activity indicated that ebselen reduced the V(max) of the reaction (K(i) = 7.6 ± 3 μM), having negligible effect on K(M) values. Our study demonstrates that ebselen is a potent non-competitive inhibitor of extracellular NDPK.
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Hu L, Lu S, Yang F, Feng J, Liu Z, Xu H, He H. Synthesis of 2-Phosphono Alkyl 1,2-Benzisoselenazol-3(2H)-ones. PHOSPHORUS SULFUR 2010. [DOI: 10.1080/10426500214892] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Liming Hu
- a Central China Normal University , Wuhan, China
- b Wuhan University , Wuhan, China
| | - Shengmei Lu
- a Central China Normal University , Wuhan, China
| | | | - Juhong Feng
- a Central China Normal University , Wuhan, China
| | - Zhaojie Liu
- a Central China Normal University , Wuhan, China
| | | | - Hongwu He
- a Central China Normal University , Wuhan, China
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Abstract
Opportunistic pathogens have become of increasing medical importance over the last decade due to the AIDS pandemic. Not only is cryptococcosis the fourth-most-common fatal infectious disease in sub-Saharan Africa, but also Cryptococcus is an emerging pathogen of immunocompetent individuals. The interaction between Cryptococcus and the host's immune system is a major determinant for the outcome of disease. Despite initial infection in early childhood with Cryptococcus neoformans and frequent exposure to C. neoformans within the environment, immunocompetent individuals are generally able to contain the fungus or maintain the yeast in a latent state. However, immune deficiencies lead to disseminating infections that are uniformly fatal without rapid clinical intervention. This review will discuss the innate and adaptive immune responses to Cryptococcus and cryptococcal strategies to evade the host's defense mechanisms. It will also address the importance of these strategies in pathogenesis and the potential of immunotherapy in cryptococcosis treatment.
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Billack B, Piętka-Ottlik M, Santoro M, Nicholson S, Młochowski J, Lau-Cam C. Evaluation of the antifungal and plasma membrane H+-ATPase inhibitory action of ebselen and two ebselen analogs in S. cerevisiae cultures. J Enzyme Inhib Med Chem 2010; 25:312-7. [DOI: 10.3109/14756360903179419] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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A putative P-type ATPase, Apt1, is involved in stress tolerance and virulence in Cryptococcus neoformans. EUKARYOTIC CELL 2009; 9:74-83. [PMID: 19949048 DOI: 10.1128/ec.00289-09] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The export of virulence factors, such as the capsule polysaccharide, to the cell surface is a critical aspect of the pathogenicity of Cryptococcus neoformans. A view of capsule export via exocytosis and extracellular vesicles is emerging, but the molecular mechanisms underlying virulence factor transport pathways remain to be established. In this study, we characterized the APT1 gene, which encodes a predicted integral membrane P-type ATPase belonging to the type IV, Drs2 family of aminophospholipid translocases (flippases) (APTs). APTs maintain the phospholipid asymmetry that is critical in membrane fusion events for trafficking and in establishing cell polarity. Deletion of the APT1 gene resulted in phenotypes consistent with similar roles in C. neoformans. These included altered actin distribution, increased sensitivity to stress conditions (oxidative and nitrosative stress) and to trafficking inhibitors, such as brefeldin A and monensin, a reduction in exported acid phosphatase activity, and hypersensitivity to the antifungal drugs amphotericin B, fluconazole, and cinnamycin. However, there was no difference in growth, capsule size, or melanin production between the wild type and the apt1 mutant strains at either 30 degrees C or 37 degrees C. Despite the absence of an influence on these major virulence factors, Apt1 was required for survival during interactions with macrophages, and apt1 mutants exhibited attenuated virulence in a mouse inhalation model of cryptococcosis. Therefore, Apt1 contributes to virulence and the stress response in C. neoformans through apparent functions in membrane fusion and trafficking that do not influence the deposition of major virulence factors, such as capsule and melanin, outside the cell.
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Billack B, Santoro M, Lau-Cam C. Growth Inhibitory Action of Ebselen on Fluconazole-Resistant Candida albicans: Role of the Plasma Membrane H+-ATPase. Microb Drug Resist 2009; 15:77-83. [DOI: 10.1089/mdr.2009.0872] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Blase Billack
- Department of Pharmaceutical Sciences, College of Pharmacy and Allied Health Professions, St. John's University, Jamaica, New York
| | - Michelle Santoro
- Department of Pharmaceutical Sciences, College of Pharmacy and Allied Health Professions, St. John's University, Jamaica, New York
| | - Cesar Lau-Cam
- Department of Pharmaceutical Sciences, College of Pharmacy and Allied Health Professions, St. John's University, Jamaica, New York
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Garcia J, Shea J, Alvarez-Vasquez F, Qureshi A, Luberto C, Voit EO, Del Poeta M. Mathematical modeling of pathogenicity of Cryptococcus neoformans. Mol Syst Biol 2008; 4:183. [PMID: 18414484 PMCID: PMC2387229 DOI: 10.1038/msb.2008.17] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2007] [Accepted: 02/20/2008] [Indexed: 01/06/2023] Open
Abstract
Cryptococcus neoformans (Cn) is the most common cause of fungal meningitis worldwide. In infected patients, growth of the fungus can occur within the phagolysosome of phagocytic cells, especially in non-activated macrophages of immunocompromised subjects. Since this environment is characteristically acidic, Cn must adapt to low pH to survive and efficiently cause disease. In the present work, we designed, tested, and experimentally validated a theoretical model of the sphingolipid biochemical pathway in Cn under acidic conditions. Simulations of metabolic fluxes and enzyme deletions or downregulation led to predictions that show good agreement with experimental results generated post hoc and reconcile intuitively puzzling results. This study demonstrates how biochemical modeling can yield testable predictions and aid our understanding of fungal pathogenesis through the design and computational simulation of hypothetical experiments.
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Affiliation(s)
- Jacqueline Garcia
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
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Chan G, Hardej D, Santoro M, Lau-Cam C, Billack B. Evaluation of the antimicrobial activity of ebselen: Role of the yeast plasma membrane H+-ATPase. J Biochem Mol Toxicol 2007; 21:252-64. [PMID: 17912695 DOI: 10.1002/jbt.20189] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one) is a selenium-containing antioxidant demonstrating anti-inflammatory and cytoprotective properties in mammalian cells and cytotoxicity in lower organisms. The mechanism underlying the antimicrobial activity of ebselen remains unclear. It has recently been proposed that, in lower organisms like yeast, the plasma membrane H+-ATPase (Pma1p) could serve as a potential target for this synthetic organoselenium compound. Using yeast and bacteria, the present study found ebselen to inhibit microbial growth in a concentration- and time-dependent manner, and yeast and Gram-positive bacteria to be more sensitive to this action (IC50 approximately 2-5 microM) than Gram-negative bacteria (IC50 < 80 microM). Washout experiments and scanning electron microscopic analysis revealed ebselen to possess fungicidal activity. In addition, ebselen was found to inhibit medium acidification by PMA1-proficient haploid yeast in a concentration-dependent manner. Additional studies comparing PMA1 (+/-) and PMA1 (+/+) diploid yeast cells revealed the mutant to be more sensitive to treatment with ebselen than the wild type. Ebselen also inhibited the ATPase activity of Pma1p from S. cerevisiae in a concentration-dependent manner. The interaction of ebselen with the sulfhydryl-containing compounds L-cysteine and reduced glutathione resulted in the complete and partial prevention, respectively, of the inhibition of Pma1p ATPase activity by ebselen. Taken together, these results suggest that the fungicidal action of ebselen is due, at least in part, to interference with both the proton-translocating function and the ATPase activity of the plasma membrane H+-ATPase.
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Affiliation(s)
- Grace Chan
- Department of Pharmaceutical Sciences, College of Pharmacy and Allied Health Professions, St. John's University, Jamaica, NY 11439, USA
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Shea JM, Kechichian TB, Luberto C, Del Poeta M. The cryptococcal enzyme inositol phosphosphingolipid-phospholipase C confers resistance to the antifungal effects of macrophages and promotes fungal dissemination to the central nervous system. Infect Immun 2006; 74:5977-88. [PMID: 16988277 PMCID: PMC1594881 DOI: 10.1128/iai.00768-06] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In recent years, sphingolipids have emerged as critical molecules in the regulation of microbial pathogenesis. In fungi, the synthesis of complex sphingolipids is important for the regulation of pathogenicity, but the role of sphingolipid degradation in fungal virulence is not known. Here, we isolated and characterized the inositol phosphosphingolipid-phospholipase C1 (ISC1) gene from the fungal pathogen Cryptococcus neoformans and showed that it encodes an enzyme that metabolizes fungal inositol sphingolipids. Isc1 protects C. neoformans from acidic, oxidative, and nitrosative stresses, which are encountered by the fungus in the phagolysosomes of activated macrophages, through a Pma1-dependent mechanism(s). In an immunocompetent mouse model, the C. neoformans Deltaisc1 mutant strain is almost exclusively found extracellularly and in a hyperencapsulated form, and its dissemination to the brain is remarkably reduced compared to that of control strains. Interestingly, the dissemination of the C. neoformans Deltaisc1 strain to the brain is promptly restored in these mice when alveolar macrophages are pharmacologically depleted or when infecting an immunodeficient mouse in which macrophages are not efficiently activated. These studies suggest that Isc1 plays a key role in protecting C. neoformans from the intracellular environment of macrophages, whose activation is important for preventing fungal dissemination of the Deltaisc1 strain to the central nervous system and the development of meningoencephalitis.
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Affiliation(s)
- John M Shea
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, 173 Ashley Avenue, BSB 503, Charleston, SC 29425, USA
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Abstract
Comparative analyses of fungal genomes and molecular research on genes associated with fungal viability and virulence has led to the identification of many putative targets for novel antifungal agents. So far the rational approach to antifungal discovery, in which compounds are optimized against an individual target then progressed to efficacy against intact fungi and ultimately to infected humans has delivered no new agents. However, the approach continues to hold promise for the future. This review critically assesses the molecular target-based approach to antifungal discovery, outlines problems and pitfalls inherent in the genomics and target discovery strategies and describes the status of heavily investigated examples of target-based research.
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Affiliation(s)
- Frank C Odds
- Aberdeen Fungal Group, Institute of Medical Sciences, Department of Molecular and Cell Biology, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, Scotland, UK.
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Junior IC, Rodrigues ML, Alviano CS, Travassos LR, Meyer-Fernandes JR. Characterization of an ecto-ATPase activity in Cryptococcus neoformans. FEMS Yeast Res 2005; 5:899-907. [PMID: 15951247 DOI: 10.1016/j.femsyr.2005.04.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2005] [Revised: 04/05/2005] [Accepted: 04/18/2005] [Indexed: 11/18/2022] Open
Abstract
Cryptococcus neoformans is the causative agent of pulmonary cryptococcosis and cryptococcal meningoencephalitis, which are major clinical manifestations in immunosuppressed patients. In the present study, a surface ATPase (ecto-ATPase) was identified in C. neoformans yeast cells. Intact yeasts hydrolyzed adenosine-5'-triphosphate (ATP) at a rate of 29.36+/-3.36nmol Pi/hx10(8) cells. In the presence of 5 mM MgCl(2), this activity was enhanced around 70 times, and an apparent K(m) for Mg-ATP corresponding to 0.61mM was determined. Inhibitors of phosphatases, mitochondrial Mg(2+)-ATPases, V-ATPases, Na(+)-ATPases or P-ATPases had no effect on the cryptococcal ATPase, but extracellular impermeant compounds reduced enzyme activity in living cells. ATP was the best substrate for the cryptococcal ecto-enzyme, but it also efficiently hydrolyzed inosine 5'-triphosphate (ITP), cytidine 5'-triphosphate (CTP), guanosine 5'-triphosphate (GTP) and uridine-5'-triphosphate (UTP). In the presence of ATP, C. neoformans became less susceptible to the antifungal action of fluconazole. Our results are indicative of the occurrence of a C. neoformans ecto-ATPase that may have a role in fungal physiology.
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Affiliation(s)
- Itallo Collopy Junior
- Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, CCS, Bloco H, Cidade Universitária, Ilha do Fundão, 21541-590 Rio de Janeiro, RJ, Brazil
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Paderu P, Park S, Perlin DS. Caspofungin uptake is mediated by a high-affinity transporter in Candida albicans. Antimicrob Agents Chemother 2004; 48:3845-9. [PMID: 15388444 PMCID: PMC521903 DOI: 10.1128/aac.48.10.3845-3849.2004] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The uptake of the echinocandin drug caspofungin acetate in Candida albicans was evaluated at drug levels at or near the MIC for the organism. Maximal uptake was achieved in 10 min and was energy independent. A saturable transport system, consistent with a facilitated-diffusion carrier, was observed with the unlabeled drug competing with the labeled drug for uptake and efflux. More than 90% of the transported drug was observed in a single kinetic compartment that was available for efflux, indicating that the drug was free in the cytoplasm following uptake. Efflux was also energy independent but was sensitive to the presence of a fully loaded carrier on both faces of the bilayer. Overall, the data presented are consistent with the presence of a high-affinity facilitated-diffusion transporter that mediates caspofungin uptake and could be a potential source of transport-related reduced susceptibility.
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Affiliation(s)
- Padmaja Paderu
- Public Health Research Institute at the International Center for Public Health, 225 Warren St., Newark, NJ 07103, USA
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Abstract
The antifungal activity of synthetic, nonchemotherapeutic compounds, antineoplastic agents and antibacterial drugs, such as sulphonamides, has been known since the early 20th century (1932). In this context, the term "nonantifungal" is taken to include a variety of compounds that are employed in the management of pathological conditions of nonfungal infectious etiology but have been shown to exhibit broad-spectrum antifungal activity. In this review, the antifungal properties of compounds such as chlorpromazine, proton pump inhibitors, antiarrhythmic agents, cholesterol-lowering agents, antineoplastic and immunosuppressive agents, antiparasitic drugs and antibiotics are described. Since fungi are eukaryotic cells, they share many pathways with human cells, thus increasing the probability of antifungal activity of "nonfungal drugs". The potential of these drugs for treatment of fungal infections has been investigated sporadically using the drugs alone or in combination with "classic" antifungal agents. A review of the literature, supplemented with a number of more recent investigations, suggests that some of these compounds enhance the activity of conventional antifungal agents, eliminate natural resistance to specific antifungal drugs (reversal of resistance) or exhibit strong activity against certain fungal strains in vitro and in animal models. The role of these agents in the epidemiology and in the clinical manifestations of fungal infections and the potential of certain drugs for treatment of invasive fungal infections require further investigation.
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Affiliation(s)
- J Afeltra
- Department of Medical Microbiology, University Medical Center Nijmegen, PO Box 9101, 6500 HB Nijmegen, The Netherlands
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Vanden Bossche H, Engelen M, Rochette F. Antifungal agents of use in animal health--chemical, biochemical and pharmacological aspects. J Vet Pharmacol Ther 2003; 26:5-29. [PMID: 12603774 DOI: 10.1046/j.1365-2885.2003.00456.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A limited number of antifungal agents is licensed for use in animals, however, many of those available for the treatment of mycoses in humans are used by veterinary practitioners. This review includes chemical aspects, spectra of activity, mechanisms of action and resistance, adverse reactions and drug interactions of the antifungals in current use.
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Posteraro B, Sanguinetti M, Sanglard D, La Sorda M, Boccia S, Romano L, Morace G, Fadda G. Identification and characterization of a Cryptococcus neoformans ATP binding cassette (ABC) transporter-encoding gene, CnAFR1, involved in the resistance to fluconazole. Mol Microbiol 2003; 47:357-71. [PMID: 12519188 DOI: 10.1046/j.1365-2958.2003.03281.x] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Resistance to fluconazole is a possible event during prolonged suppressive drug therapy for cryptococ-cal meningitis, the most frequently encountered life-threatening manifestation of cryptococcosis. The knowledge of this resistance at the molecular level is important for management of cryptococcosis. In order to identify genes involved in azole resistance in Cryptococcus neoformans, a cDNA subtraction library technique was chosen as a strategy. First, a fluconazole-resistant mutant BPY22.17 was obtained from a susceptible clinical isolate BPY22 by in vitro exposure to the drug. Then, a subtractive hybridization procedure was used to compare gene expression between the obtained strains. We identified a cDNA overexpressed in the fluconazole-resistant strain BPY22.17 that was used as a probe to isolate the entire gene in a C. neoformans genomic library. Sequence analysis of this gene identified an ATP Binding Cassette (ABC) transporter-encoding gene called C. neoformans AntiFungal Resistance 1 (CnAFR1). Disruption of CnAFR1 gene in the resistant isolate (BPY22.17) resulted in an enhanced susceptibility of the knock-out mutant cnafr1 against fluconazole, whereas reintroduction of the gene in cnafr1 resulted in restoration of the resistance phenotype, thus confirming that CnAFR1 is involved in fluconazole resistance of C. neoformans. Our findings therefore reveal that an active drug efflux mechanism can be involved in the development of azole resistance in this important human pathogen.
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Affiliation(s)
- Brunella Posteraro
- Istituto Microbiologia, Università Cattolica del S. Cuore, L. go F. Vito, 1, 00168 Rome, Italy
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Burghoorn HP, Soteropoulos P, Paderu P, Kashiwazaki R, Perlin DS. Molecular evaluation of the plasma membrane proton pump from Aspergillus fumigatus. Antimicrob Agents Chemother 2002; 46:615-24. [PMID: 11850239 PMCID: PMC127506 DOI: 10.1128/aac.46.3.615-624.2002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The gene encoding the plasma membrane proton pump (H+ -ATPase) of Aspergillus fumigatus, PMA1, was characterized from A. fumigatus strain NIH 5233 and clinical isolate H11-20. An open reading frame of 3,109 nucleotides with two introns near the N terminus predicts a protein consisting of 989 amino acids with a molecular mass of approximately 108 kDa. The predicted A. fumigatus enzyme is 89 and 51% identical to H+ - ATPases of Aspergillus nidulans and Saccharomyces cerevisiae, respectively. The A. fumigatus PMA1 is a typical member of the P-type ATPase family that contains 10 predicted transmembrane segments and conserved sequence motifs TGES, CSDKTGT, MLTGD, and GDGVN within the catalytic region. The enzyme represents 2% of the total plasma membrane protein, and it is characteristically inhibited by orthovanadate, with a 50% inhibitory concentration of approximately 1.8 microM. H+ -ATPases from Aspergillus spp. contain a highly acidic insertion region of 60 amino acids between transmembrane segments 2 and 3, which was confirmed for the membrane-assembled enzyme with a peptide-derived antibody. An increasing A. fumigatus PMA1 copy number confers enhanced growth in low-pH medium, consistent with its role as a proton pump. These results provide support for the development of the A. fumigatus H+ -ATPase as a potential drug discovery target.
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