151
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Alonso L, Mendanha SA, Dorta ML, Alonso A. Analysis of the Interactions of Amphotericin B with the Leishmania Plasma Membrane Using EPR Spectroscopy. J Phys Chem B 2020; 124:10157-10165. [DOI: 10.1021/acs.jpcb.0c07721] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Lais Alonso
- Instituto Federal Goiano, Trindade 76300-000, Goiás, Brazil
- Instituto de Física, Universidade Federal de Goiás, Goiânia 74690-900, Goiás, Brazil
| | | | - Miriam Leandro Dorta
- Instituto de Patologia Tropical e Saúde Publica, Departamento de Imunologia e Patologia Geral, Universidade Federal de Goiás, Goiânia 74690-900, Goiás, Brazil
| | - Antonio Alonso
- Instituto de Física, Universidade Federal de Goiás, Goiânia 74690-900, Goiás, Brazil
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152
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Rivas A, Areal A, Mora P, Álvarez R, de Lera AR. Synthesis of Symmetrical and Nonsymmetrical Polyenes by Iterative and Bidirectional Palladium-Catalyzed Cross-Coupling Reactions. Chemistry 2020; 26:13543-13567. [PMID: 32267574 DOI: 10.1002/chem.202000624] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 04/08/2020] [Indexed: 11/06/2022]
Abstract
Bifunctional unsaturated reagents designed to undergo palladium-catalyzed cross-coupling reactions with complementary polyenyl connective fragments are highly useful for the undoubtedly challenging synthesis of polyenes. The current toolkit of building blocks for the bidirectional formation of Csp2 -Csp2 single bonds of polyenes includes homo-bisfunctionalized reagents with equal or unequal reactivity (due to steric and/or electronic factors), and hetero-bisfunctionalized counterparts containing either two different nucleophiles, two electrophiles or one of these functionalities and a latent nucleophile that can be unmasked when desired. The combination of these bifunctional linchpin reagents using tactics that modulate the reactivity of each terminus in order to achieve the required connection have streamlined the synthesis of polyenes of great complexity using (iterative) cross-coupling methods for Csp2 -Csp2 bond formation. Reaction conditions for the Pd-catalyzed cross-coupling reactions are mild and functional-group-tolerant, and therefore these protocols allow to construct the polyene structures using shorter unsaturated reactants with the desired geometries, since in general the products preserve the stereochemical information of the connected cross-coupling partners.
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Affiliation(s)
- Aurea Rivas
- Departamento de Química Orgánica, Facultade de Química, CINBIO and IIS Galicia Sur, Universidade de Vigo, 36310, Vigo, Spain
| | - Andrea Areal
- Departamento de Química Orgánica, Facultade de Química, CINBIO and IIS Galicia Sur, Universidade de Vigo, 36310, Vigo, Spain
| | - Paula Mora
- Departamento de Química Orgánica, Facultade de Química, CINBIO and IIS Galicia Sur, Universidade de Vigo, 36310, Vigo, Spain
| | - Rosana Álvarez
- Departamento de Química Orgánica, Facultade de Química, CINBIO and IIS Galicia Sur, Universidade de Vigo, 36310, Vigo, Spain
| | - Angel R de Lera
- Departamento de Química Orgánica, Facultade de Química, CINBIO and IIS Galicia Sur, Universidade de Vigo, 36310, Vigo, Spain
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153
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What do we know about the biology of the emerging fungal pathogen of humans Candida auris? Microbiol Res 2020; 242:126621. [PMID: 33096325 DOI: 10.1016/j.micres.2020.126621] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/25/2020] [Accepted: 10/04/2020] [Indexed: 02/07/2023]
Abstract
Candida auris is a worrisome fungal pathogen of humans which emerged merely about a decade ago. Ever since then the scientific community worked hard to understand clinically relevant traits, such as virulence factors, antifungal resistance mechanisms, and its ability to adhere to human skin and medical devices. Whole-genome sequencing of clinical isolates and epidemiological studies outlining the path of nosocomial outbreaks have been the focus of research into this pathogenic and multidrug-resistant yeast since its first description in 2009. More recently, work was started by several laboratories to explore the biology of C. auris. Here, we review the insights of studies characterizing the mechanisms underpinning antifungal drug resistance, biofilm formation, morphogenetic switching, cell aggregation, virulence, and pathogenicity of C. auris. We conclude that, although some progress has been made, there is still a long journey ahead of us, before we fully understand this novel pathogen. Critically important is the development of molecular tools for C. auris to make this fungus genetically tractable and traceable. This will allow an in-depth molecular dissection of the life cycle of C. auris, of its characteristics while interacting with the human host, and the mechanisms it employs to avoid being killed by antifungals and the immune system.
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154
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Chikina AS, Nadalin F, Maurin M, San-Roman M, Thomas-Bonafos T, Li XV, Lameiras S, Baulande S, Henri S, Malissen B, Lacerda Mariano L, Barbazan J, Blander JM, Iliev ID, Matic Vignjevic D, Lennon-Duménil AM. Macrophages Maintain Epithelium Integrity by Limiting Fungal Product Absorption. Cell 2020; 183:411-428.e16. [PMID: 32970988 PMCID: PMC7646275 DOI: 10.1016/j.cell.2020.08.048] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/27/2020] [Accepted: 08/26/2020] [Indexed: 12/14/2022]
Abstract
The colon is primarily responsible for absorbing fluids. It contains a large number of microorganisms including fungi, which are enriched in its distal segment. The colonic mucosa must therefore tightly regulate fluid influx to control absorption of fungal metabolites, which can be toxic to epithelial cells and lead to barrier dysfunction. How this is achieved remains unknown. Here, we describe a mechanism by which the innate immune system allows rapid quality check of absorbed fluids to avoid intoxication of colonocytes. This mechanism relies on a population of distal colon macrophages that are equipped with "balloon-like" protrusions (BLPs) inserted in the epithelium, which sample absorbed fluids. In the absence of macrophages or BLPs, epithelial cells keep absorbing fluids containing fungal products, leading to their death and subsequent loss of epithelial barrier integrity. These results reveal an unexpected and essential role of macrophages in the maintenance of colon-microbiota interactions in homeostasis. VIDEO ABSTRACT.
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Affiliation(s)
- Aleksandra S Chikina
- Institut Curie, PSL Research University, CNRS UMR 144, F-75005 Paris, France; Institut Curie, PSL Research University, INSERM U932, F-75005 Paris, France
| | - Francesca Nadalin
- Institut Curie, PSL Research University, INSERM U932, F-75005 Paris, France
| | - Mathieu Maurin
- Institut Curie, PSL Research University, INSERM U932, F-75005 Paris, France
| | - Mabel San-Roman
- Institut Curie, PSL Research University, INSERM U932, F-75005 Paris, France
| | | | - Xin V Li
- Gastroenterology and Hepatology Division, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, Cornell University, New York, NY 10021, USA; The Jill Roberts Institute for Research in Inflammatory Bowel Disease, Weill Cornell Medicine, Cornell University, New York, NY 10021, USA
| | - Sonia Lameiras
- Institut Curie, PSL Research University, Next Generation Sequencing Facility, F-75005 Paris, France
| | - Sylvain Baulande
- Institut Curie, PSL Research University, Next Generation Sequencing Facility, F-75005 Paris, France
| | - Sandrine Henri
- Centre d'Immunologie de Marseille-Luminy, Aix Marseille Université, INSERM, CNRS, 13288 Marseille, France
| | - Bernard Malissen
- Centre d'Immunologie de Marseille-Luminy, Aix Marseille Université, INSERM, CNRS, 13288 Marseille, France; Centre d'Immunophénomique, Aix Marseille Université, INSERM, CNRS, 13288 Marseille, France
| | | | - Jorge Barbazan
- Institut Curie, PSL Research University, CNRS UMR 144, F-75005 Paris, France
| | - J Magarian Blander
- The Jill Roberts Institute for Research in Inflammatory Bowel Disease, Weill Cornell Medicine, Cornell University, New York, NY 10021, USA
| | - Iliyan D Iliev
- Gastroenterology and Hepatology Division, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, Cornell University, New York, NY 10021, USA; The Jill Roberts Institute for Research in Inflammatory Bowel Disease, Weill Cornell Medicine, Cornell University, New York, NY 10021, USA
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155
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Mescola A, Ragazzini G, Alessandrini A. Daptomycin Strongly Affects the Phase Behavior of Model Lipid Bilayers. J Phys Chem B 2020; 124:8562-8571. [PMID: 32886515 DOI: 10.1021/acs.jpcb.0c06640] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Daptomycin (DAP) is a calcium-dependent cyclic lipopeptide with great affinity for negatively charged phospholipids bearing the phosphatidylglycerol (PG) headgroup and has been used since 2003 as a last resort antibiotic in the treatment of severe infections caused by Gram-positive bacteria. The first step of its mechanism of action involves the interaction with the bacterial membrane, which not only represents a physical barrier but also accommodates transmembrane proteins, such as receptors, transporters, and enzymes, whose activity is crucial for the survival of bacteria. This results in a less efficient development of resistance strategies by pathogens compared to common antibiotics that activate or inhibit biochemical pathways connected to specific target proteins. Although already on the market, the molecular mechanism of action of DAP is still a controversial subject of investigation and it is most likely the result of a combination of distinct effects. Understanding how DAP targets the membrane of pathogens could be of great help in finding its analogues that could better avoid the development of resistance. Here, exploiting fluorescence microscopy and atomic force microscopy (AFM), we demonstrated that DAP affects the thermodynamic behavior of lipid mixtures containing PG moieties. Regardless of whether the PG lipids are in the liquid or solid phase, DAP preferably interacts with this headgroup and is able to penetrate more deeply into the lipid bilayer in the regions where this headgroup is present. In particular, considering the results of an AFM/spectroscopy investigation, DAP appears to produce a stiffening effect of the domains where PG lipids are mainly in the fluid phase, whereas it causes fluidification of the domains where PG lipids are in the solid phase.
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Affiliation(s)
- Andrea Mescola
- CNR-Nanoscience Institute-S3, Via Campi 213/A, 41125 Modena, Italy
| | - Gregorio Ragazzini
- CNR-Nanoscience Institute-S3, Via Campi 213/A, 41125 Modena, Italy.,Department of Physics, Informatics and Mathematics, University of Modena and Reggio Emilia, Via Campi 213/A, 41125 Modena, Italy
| | - Andrea Alessandrini
- CNR-Nanoscience Institute-S3, Via Campi 213/A, 41125 Modena, Italy.,Department of Physics, Informatics and Mathematics, University of Modena and Reggio Emilia, Via Campi 213/A, 41125 Modena, Italy
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156
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Xue A, Robbins N, Cowen LE. Advances in fungal chemical genomics for the discovery of new antifungal agents. Ann N Y Acad Sci 2020; 1496:5-22. [PMID: 32860238 DOI: 10.1111/nyas.14484] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 08/09/2020] [Accepted: 08/13/2020] [Indexed: 12/15/2022]
Abstract
Invasive fungal infections have escalated from a rare curiosity to a major cause of human mortality around the globe. This is in part due to a scarcity in the number of antifungal drugs available to combat mycotic disease, making the discovery of novel bioactive compounds and determining their mode of action of utmost importance. The development and application of chemical genomic assays using the model yeast Saccharomyces cerevisiae has provided powerful methods to identify the mechanism of action of diverse molecules in a living cell. Furthermore, complementary assays are continually being developed in fungal pathogens, most notably Candida albicans and Cryptococcus neoformans, to elucidate compound mechanism of action directly in the pathogen of interest. Collectively, the suite of chemical genetic assays that have been developed in multiple fungal species enables the identification of candidate drug target genes, as well as genes involved in buffering drug target pathways, and genes involved in general cellular responses to small molecules. In this review, we examine current yeast chemical genomic assays and highlight how such resources provide powerful tools that can be utilized to bolster the antifungal pipeline.
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Affiliation(s)
- Alice Xue
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Nicole Robbins
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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157
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Current Antimycotics, New Prospects, and Future Approaches to Antifungal Therapy. Antibiotics (Basel) 2020; 9:antibiotics9080445. [PMID: 32722455 PMCID: PMC7460292 DOI: 10.3390/antibiotics9080445] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/22/2020] [Accepted: 07/23/2020] [Indexed: 12/11/2022] Open
Abstract
Fungal infections represent an increasing threat to a growing number of immune- and medically compromised patients. Fungi are eukaryotic organisms and, as such, there is a limited number of selective targets that can be exploited for antifungal drug development. This has also resulted in a very restricted number of antifungal drugs that are clinically available for the treatment of invasive fungal infections at the present time—polyenes, azoles, echinocandins, and flucytosine. Moreover, the utility of available antifungals is limited by toxicity, drug interactions and the emergence of resistance, which contribute to high morbidity and mortality rates. This review will present a brief summary on the landscape of current antifungals and those at different stages of clinical development. We will also briefly touch upon potential new targets and opportunities for novel antifungal strategies to combat the threat of fungal infections.
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158
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Rasheed M, Battu A, Kaur R. Host-pathogen interaction in Candida glabrata infection: current knowledge and implications for antifungal therapy. Expert Rev Anti Infect Ther 2020; 18:1093-1103. [PMID: 32668993 DOI: 10.1080/14787210.2020.1792773] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
INTRODUCTION The opportunistic fungal pathogen Candida glabrata poses a clinical challenge in the successful treatment of invasive Candida infections, owing to its low inherent susceptibility toward azole antifungals and the recent acquisition of coresistance toward azole and echinocandin drugs. Compared to other prevalent Candida bloodstream pathogens, C. glabrata neither exhibits secreted proteolytic activity nor invokes a strong immune response in a variety of host cells and is less virulent. It also does not form true hyphae, and the success of C. glabrata, therefore, as a prevalent human fungal pathogen, appears to be built upon a distinct set of virulence attributes. AREAS COVERED The focus of this review is to outline, in brief, the interaction of C. glabrata with the host, deduced from the knowledge gained from different in vitro, ex vivo, and in vivo model systems. In addition, we briefly discuss the current antifungals, antifungal resistance mechanisms, and the development of new antifungal therapies, along with the available information on the host response. EXPERT OPINION A detailed understanding of stresses, selection pressures and differential immune responses in the presence and absence of antifungals that C. glabrata encounters in varied niches of the host, is required to design effective antifungal therapy.
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Affiliation(s)
- Mubashshir Rasheed
- Laboratory of Fungal Pathogenesis, Centre for DNA Fingerprinting and Diagnostics , Hyderabad, India
| | - Anamika Battu
- Laboratory of Fungal Pathogenesis, Centre for DNA Fingerprinting and Diagnostics , Hyderabad, India.,Graduate Studies, Manipal Academy of Higher Education , Manipal, India
| | - Rupinder Kaur
- Laboratory of Fungal Pathogenesis, Centre for DNA Fingerprinting and Diagnostics , Hyderabad, India
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159
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Adler-Moore J, Lewis RE, Brüggemann RJM, Rijnders BJA, Groll AH, Walsh TJ. Preclinical Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Antifungal Activity of Liposomal Amphotericin B. Clin Infect Dis 2020; 68:S244-S259. [PMID: 31222254 PMCID: PMC6495008 DOI: 10.1093/cid/ciz064] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The improved safety profile and antifungal efficacy of liposomal amphotericin B (LAmB) compared to conventional amphotericin B deoxycholate (DAmB) is due to several factors including, its chemical composition, rigorous manufacturing standards, and ability to target and transit through the fungal cell wall. Numerous preclinical studies have shown that LAmB administered intravenously distributes to tissues frequently infected by fungi at levels above the minimum inhibitory concentration (MIC) for many fungi. These concentrations can be maintained from one day to a few weeks, depending upon the tissue. Tissue accumulation is dose-dependent with drug clearance occurring most rapidly from the brain and slowest from the liver and spleen. LAmB localizes in lung epithelial lining fluid, within liver and splenic macrophages and in kidney distal tubules. LAmB has been used successfully in therapeutic and prophylactic animal models to treat many different fungal pathogens, significantly increasing survival and reducing tissue fungal burden.
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Affiliation(s)
- Jill Adler-Moore
- Department of Biological Sciences, California State Polytechnic University, Pomona
| | - Russell E Lewis
- Unit of Infectious Diseases, Policlinico Sant'Orsola-Malpighi, Department of Medical Sciences and Surgery, University of Bologna, Italy
| | - Roger J M Brüggemann
- Department of Pharmacy, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Bart J A Rijnders
- Department of Internal Medicine, Section of Infectious Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Andreas H Groll
- Infectious Disease Research Program, Department of Pediatric Hematology and Oncology and Center for Bone Marrow Transplantation, University Children's Hospital Muenster, Germany
| | - Thomas J Walsh
- Departments of Medicine, Pediatrics, and Microbiology & Immunology, Weill Cornell Medicine of Cornell University, New York, New York
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160
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Antimicrobial and Antifungal Activity of Rare Substituted 1,2,3-Thiaselenazoles and Corresponding Matched Pair 1,2,3-Dithiazoles. Antibiotics (Basel) 2020; 9:antibiotics9070369. [PMID: 32630252 PMCID: PMC7400446 DOI: 10.3390/antibiotics9070369] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 06/23/2020] [Accepted: 06/26/2020] [Indexed: 12/22/2022] Open
Abstract
We report our investigations into the underlying differences between 1,2,3-dithiazole and their ultra-rare counterpart, 1,2,3-thiaselenazole. This rare 1,2,3-thiaselenazole chemotype was afforded by sulfur extrusion and selenium insertion into the preconstructed 1,2,3-dithiazoles. We built a library of matched paired compounds to compare and contrast the two ring systems. This led to the development of both narrow and broad-spectrum antimicrobial compounds with sub-micro molar potency, limited to no toxicity and a further understanding of the transition state electronics through molecular simulations. We also identified the potent 4,5,6-trichlorocyclopenta[d][1,2,3]thiaselenazole 11a, for use against Candida albicans, Cryptococcus neoformans var. grubii, Staphylococcus aureus and Acinetobacter baumannii, all of which have limited clinical treatment options. The 1,2,3-thiaselenazole represents a new class of potential compounds for the treatment of a host of multi-resistant hospital derived infections.
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161
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Proper regulation of inositolphosphorylceramide levels is required for acquirement of low pH resistance in budding yeast. Sci Rep 2020; 10:10792. [PMID: 32612142 PMCID: PMC7329899 DOI: 10.1038/s41598-020-67734-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 06/12/2020] [Indexed: 02/04/2023] Open
Abstract
All organisms have stress response systems to protect themselves from various environmental stresses, and regulation of membrane lipids is thought to play an important role in acquirement of stress tolerance. Complex sphingolipids in the yeast Saccharomyces cerevisiae are classified into three types based on differences in the structure of the polar head group, and the compositions and quantities of complex sphingolipids in biomembranes are tightly regulated. In this study, we found that the accumulation of inositol phosphorylceramides (IPCs) due to a defect of mannosylinositol phosphorylceramide biosynthesis (sur1∆ csh1∆), i.e., disruption of the balance of the composition of complex sphingolipids, causes hypersensitivity to low pH conditions (pH 4.0–2.5). Furthermore, screening of suppressor mutations that confer low pH resistance to sur1∆ csh1∆ cells revealed that a change in ergosterol homeostasis at plasma membranes can rescue the hypersensitivity, suggesting the functional relationship between complex sphingolipids and ergosterol under low pH conditions. Under low pH conditions, wild-type yeast cells exhibited decreases in IPC levels, and forced enhancement of the biosynthesis of IPCs causes low pH hypersensitivity. Thus, it was suggested that the accumulation of IPCs is detrimental to yeast under low pH conditions, and downregulation of IPC levels is one of the adaptation mechanisms for low pH conditions.
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162
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Tan X, Baugh K, Bulman ZP, Wenzler E. Review of the Current Management of Urinary Tract Infections due to Fluconazole-Resistant and Non-Albicans Candida Species. CURRENT FUNGAL INFECTION REPORTS 2020. [DOI: 10.1007/s12281-020-00388-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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163
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Silva LN, Oliveira SSC, Magalhães LB, Andrade Neto VV, Torres-Santos EC, Carvalho MDC, Pereira MD, Branquinha MH, Santos ALS. Unmasking the Amphotericin B Resistance Mechanisms in Candida haemulonii Species Complex. ACS Infect Dis 2020; 6:1273-1282. [PMID: 32239912 DOI: 10.1021/acsinfecdis.0c00117] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The polyene amphotericin B (AMB) exerts a powerful and broad antifungal activity. AMB acts by (i) binding to ergosterol, leading to pore formation at the fungal plasma membrane with subsequent ion leakage, and (ii) inducing the intracellular accumulation of reactive oxygen species (ROS). Herein, we have deciphered the AMB resistance mechanisms in clinical isolates of Candida haemulonii complex (C. haemulonii, C. duobushaemulonii, C. haemulonii var. vulnera) in comparison to other clinically relevant non-albicans Candida species. Membrane gas chromatography-mass spectrometry analysis revealed that the vast majority of sterols were composed of ergosterol pathway intermediates, evidencing the absence of AMB target. Supporting this data, C. haemulonii species complex demonstrated poor membrane permeability after AMB treatment. Regarding the oxidative burst, AMB induced the formation of ROS in all species tested; however, this phenomenon was slightly seen in C. haemulonii complex isolates. Our results indicated that these isolates displayed altered respiratory status, as revealed by their poor growth in nonfermented carbon sources, low consumption of oxygen, and derisive mitochondrial membrane potential. The use of specific inhibitors of mitochondrial respiratory chain (complex I-IV) revealed no effects on the yeast growth, highlighting the metabolic shift to fermentative pathway in C. haemulonii strains. Also, C. haemulonii complex proved to be highly resistant to oxidative burst agents, which can be correlated with a high activity of antioxidant enzymes. Our data demonstrated primary evidence suggesting that ergosterol content, mitochondrial function, and fungal redox homeostasis are involved in AMB fungicidal effects and might explain the resistance presented in this multidrug-resistant, emergent, and opportunistic fungal complex.
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Affiliation(s)
- Laura N. Silva
- Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Bloco E - Subsolo sala 05, Rio de Janeiro 21941-902, Brazil
| | - Simone S. C. Oliveira
- Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Bloco E - Subsolo sala 05, Rio de Janeiro 21941-902, Brazil
| | - Lucas B. Magalhães
- Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Bloco E - Subsolo sala 05, Rio de Janeiro 21941-902, Brazil
| | - Valter V. Andrade Neto
- Laboratório de Bioquímica de Tripanosomatídeos, Instituto Oswaldo Cruz, Av. Brasil, 4365 - Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, Brazil
| | - Eduardo C. Torres-Santos
- Laboratório de Bioquímica de Tripanosomatídeos, Instituto Oswaldo Cruz, Av. Brasil, 4365 - Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, Brazil
| | - Mariana D. C. Carvalho
- Laboratório de Citotoxicidade e Genotoxicidade, Instituto de Química, Centro de Tecnologia, Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos, 149 - Bloco A, 5° Andar, Rio de Janeiro 21941-909, Brazil
| | - Marcos D. Pereira
- Laboratório de Citotoxicidade e Genotoxicidade, Instituto de Química, Centro de Tecnologia, Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos, 149 - Bloco A, 5° Andar, Rio de Janeiro 21941-909, Brazil
| | - Marta H. Branquinha
- Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Bloco E - Subsolo sala 05, Rio de Janeiro 21941-902, Brazil
| | - André L. S. Santos
- Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Bloco E - Subsolo sala 05, Rio de Janeiro 21941-902, Brazil
- Programa de Pós-Graduação em Bioquímica, Instituto de Química, Centro de Tecnologia, Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos, 149 - Bloco A, 5° Andar, Rio de Janeiro 21941-909, Brazil
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164
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Wambaugh MA, Denham ST, Ayala M, Brammer B, Stonhill MA, Brown JC. Synergistic and antagonistic drug interactions in the treatment of systemic fungal infections. eLife 2020; 9:54160. [PMID: 32367801 PMCID: PMC7200157 DOI: 10.7554/elife.54160] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 03/31/2020] [Indexed: 12/11/2022] Open
Abstract
Invasive fungal infections cause 1.6 million deaths annually, primarily in immunocompromised individuals. Mortality rates are as high as 90% due to limited treatments. The azole class antifungal, fluconazole, is widely available and has multi-species activity but only inhibits growth instead of killing fungal cells, necessitating long treatments. To improve treatment, we used our novel high-throughput method, the overlap2 method (O2M) to identify drugs that interact with fluconazole, either increasing or decreasing efficacy. We identified 40 molecules that act synergistically (amplify activity) and 19 molecules that act antagonistically (decrease efficacy) when combined with fluconazole. We found that critical frontline beta-lactam antibiotics antagonize fluconazole activity. A promising fluconazole-synergizing anticholinergic drug, dicyclomine, increases fungal cell permeability and inhibits nutrient intake when combined with fluconazole. In vivo, this combination doubled the time-to-endpoint of mice with Cryptococcus neoformans meningitis. Thus, our ability to rapidly identify synergistic and antagonistic drug interactions can potentially alter the patient outcomes. Individuals with weakened immune systems – such as recipients of organ transplants – can fall prey to illnesses caused by fungi that are harmless to most people. These infections are difficult to manage because few treatments exist to fight fungi, and many have severe side effects. Antifungal drugs usually slow the growth of fungi cells rather than kill them, which means that patients must remain under treatment for a long time, or even for life. One way to boost efficiency and combat resistant infections is to combine antifungal treatments with drugs that work in complementary ways: the drugs strengthen each other’s actions, and together they can potentially kill the fungus rather than slow its progression. However, not all drug combinations are helpful. In fact, certain drugs may interact in ways that make treatment less effective. This is particularly concerning because people with weakened immune systems often take many types of medications. Here, Wambaugh et al. harnessed a new high-throughput system to screen how 2,000 drugs (many of which already approved to treat other conditions) affected the efficiency of a common antifungal called fluconazole. This highlighted 19 drugs that made fluconazole less effective, some being antibiotics routinely used to treat patients with weakened immune systems. On the other hand, 40 drugs boosted the efficiency of fluconazole, including dicyclomine, a compound currently used to treat inflammatory bowel syndrome. In fact, pairing dicyclomine and fluconazole more than doubled the survival rate of mice with severe fungal infections. The combined treatment could target many species of harmful fungi, even those that had become resistant to fluconazole alone. The results by Wambaugh et al. point towards better treatments for individuals with serious fungal infections. Drugs already in circulation for other conditions could be used to boost the efficiency of fluconazole, while antibiotics that do not decrease the efficiency of this medication should be selected to treat at-risk patients.
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Affiliation(s)
- Morgan A Wambaugh
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, United States
| | - Steven T Denham
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, United States
| | - Magali Ayala
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, United States
| | - Brianna Brammer
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, United States
| | - Miekan A Stonhill
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, United States
| | - Jessica Cs Brown
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, United States
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165
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Kong Y, Wang Q, Cao F, Zhang X, Fang Z, Shi P, Wang H, Shen Y, Huang Z. BSC2 enhances cell resistance to AmB by inhibiting oxidative damage in Saccharomyces cerevisiae. Free Radic Res 2020; 54:231-243. [DOI: 10.1080/10715762.2020.1751151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Yingying Kong
- Key Lab of Science & Technology of Eco-textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, China
| | - Qiao Wang
- Key Lab of Science & Technology of Eco-textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, China
- Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Beijing, People’s Republic of China
| | - Fangqi Cao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Xiaoyu Zhang
- Key Lab of Science & Technology of Eco-textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, China
| | - Zhijia Fang
- Key Lab of Science & Technology of Eco-textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, China
| | - Ping Shi
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Handong Wang
- Qinghai Key Laboratory of Qinghai-Tibet Plateau Biological Resources, Northwest Institute of Plateau Biology, The Chinese Academy of Sciences, Xining, China
| | - Yuhu Shen
- Qinghai Key Laboratory of Qinghai-Tibet Plateau Biological Resources, Northwest Institute of Plateau Biology, The Chinese Academy of Sciences, Xining, China
| | - Zhiwei Huang
- Key Lab of Science & Technology of Eco-textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, China
- Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Beijing, People’s Republic of China
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166
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Galdiero E, de Alteriis E, De Natale A, D'Alterio A, Siciliano A, Guida M, Lombardi L, Falanga A, Galdiero S. Eradication of Candida albicans persister cell biofilm by the membranotropic peptide gH625. Sci Rep 2020; 10:5780. [PMID: 32238858 PMCID: PMC7113253 DOI: 10.1038/s41598-020-62746-w] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 03/09/2020] [Indexed: 01/05/2023] Open
Abstract
Biofilm formation poses an important clinical trouble due to resistance to antimicrobial agents; therefore, there is an urgent demand for new antibiofilm strategies that focus on the use of alternative compounds also in combination with conventional drugs. Drug-tolerant persisters are present in Candida albicans biofilms and are detected following treatment with high doses of amphotericin B. In this study, persisters were found in biofilms treated with amphotericin B of two clinical isolate strains, and were capable to form a new biofilm in situ. We investigated the possibility of eradicating persister-derived biofilms from these two Candida albicans strains, using the peptide gH625 analogue (gH625-M). Confocal microscopy studies allowed us to characterize the persister-derived biofilm and understand the mechanism of interaction of gH625-M with the biofilm. These findings confirm that persisters may be responsible for Candida biofilm survival, and prove that gH625-M was very effective in eradicating persister-derived biofilms both alone and in combination with conventional antifungals, mainly strengthening the antibiofilm activity of fluconazole and 5-flucytosine. Our strategy advances our insights into the development of effective antibiofilm therapeutic approaches.
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Affiliation(s)
- Emilia Galdiero
- Department of Biology, University of Naples "Federico II", via Cinthia, 80100, Naples, Italy
| | - Elisabetta de Alteriis
- Department of Biology, University of Naples "Federico II", via Cinthia, 80100, Naples, Italy
| | - Antonino De Natale
- Department of Biology, University of Naples "Federico II", via Cinthia, 80100, Naples, Italy
| | - Angela D'Alterio
- Department of Biology, University of Naples "Federico II", via Cinthia, 80100, Naples, Italy
| | - Antonietta Siciliano
- Department of Biology, University of Naples "Federico II", via Cinthia, 80100, Naples, Italy
| | - Marco Guida
- Department of Biology, University of Naples "Federico II", via Cinthia, 80100, Naples, Italy
| | - Lucia Lombardi
- Department of Pharmacy, University of Naples "Federico II", Via Mezzocannone 16, 80134, Naples, Italy
| | - Annarita Falanga
- Department of Agricultural Science, University of Naples Federico II, Via Università 100, 80055, Portici, Naples, Italy
| | - Stefania Galdiero
- Department of Pharmacy, University of Naples "Federico II", Via Mezzocannone 16, 80134, Naples, Italy.
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167
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Fukuda TTH, Cassilly CD, Gerdt JP, Henke MT, Helfrich EJN, Mevers E. Research Tales from the Clardy Laboratory: Function-Driven Natural Product Discovery. JOURNAL OF NATURAL PRODUCTS 2020; 83:744-755. [PMID: 32105475 DOI: 10.1021/acs.jnatprod.9b01086] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Over the past 70 years, the search for small molecules from nature has transformed biomedical research: natural products are the basis for half of all pharmaceuticals; the quest for total synthesis of natural products fueled development of methodologies for organic synthesis; and their biosynthesis presented unprecedented biochemical transformations, expanding our chemo-enzymatic toolkit. Initially, the discovery of small molecules was driven by bioactivity-guided fractionation. However, this approach yielded the frequent rediscovery of already known metabolites. As a result, focus shifted to identifying novel scaffolds through either structure-first methods or genome mining, relegating function as a secondary concern. Over the past two decades, the laboratory of Jon Clardy has taken an alternative route and focused on an ecology-driven, function-first approach in pursuit of uncovering bacterial small molecules with biological activity. In this review, we highlight several examples that showcase this ecology-first approach. Though the highlighted systems are diverse, unifying themes are (1) to understand how microbes interact with their host or environment, (2) to gain insights into the environmental roles of microbial metabolites, and (3) to explore pharmaceutical potential from these ecologically relevant metabolites.
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Affiliation(s)
- Taise T H Fukuda
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, United States
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Avenida do Café, s/n, 14040-903, Ribeirão Preto, SP, Brazil
| | - Chelsi D Cassilly
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Joseph P Gerdt
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Matthew T Henke
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Eric J N Helfrich
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Emily Mevers
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, United States
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168
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Bacillomycin D effectively controls growth of Malassezia globosa by disrupting the cell membrane. Appl Microbiol Biotechnol 2020; 104:3529-3540. [PMID: 32103313 DOI: 10.1007/s00253-020-10462-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 02/05/2020] [Accepted: 02/12/2020] [Indexed: 10/24/2022]
Abstract
Malassezia globosa is an opportunistic pathogen that causes various skin disorders, which disturbs people's life all the time, and conventional drugs are not completely satisfactory. Bacillomycin D (BD), an antifungal lipopeptide, could inhibit various fungi growth. However, the reports about its effect on M. globosa were not found yet. In this study, we showed that BD and BD-C16 (fatty acid chain had sixteen carbon atoms) completely inhibited growth of M. globosa at concentration of 64 μg/ml in 15 h, which was confirmed with the observation of irregular morphological change of M. globosa treated with BD. Significantly, the study on the working mechanism showed that BD induced cell death by changing cell membrane permeability and thus promoting the release of cellular contents, which may be mediated by the interaction between BD and ergosterol from membrane. Further study showed that BD reduced the overall content of cellular sterol, and interestingly, the expression of some genes involved in membrane and ergosterol synthesis were significantly upregulated, which was likely to be a feedback regulation. Besides, we found that BD had additive and synergistic effects with ketoconazole and amphotericin B, respectively, on inhibition of M. globosa, suggesting that combination use of BD with other commercial drugs could be a promising strategy to relieve skin disorders caused by M. globosa. KEY POINTS: • BD could efficiently inhibit the growth of M. globosa. • BD increases cell membrane permeability and thus promotes the release of cellular contents. • BD has additive or synergistic effect with other antifungal drugs.
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169
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Nimtrakul P, Tiyaboonchai W, Lamlertthon S. Amphotericin B Loaded Nanostructured Lipid Carriers for Parenteral Delivery: Characterization, Antifungal and In vitro Toxicity Assessment. Curr Drug Deliv 2020; 16:645-653. [PMID: 31362675 DOI: 10.2174/1567201816666190729145223] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 04/06/2019] [Accepted: 07/08/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND Amphotericin B (AmB) is important for the treatment of systemic fungal infections. Nowadays, only intravenous administration (IV) of AmB has been available due to its low aqueous solubility. Two forms of AmB are available. The first is Fungizone®, a mixture of AmB and sodium deoxcycholate that produces severe nephrotoxicity. The second are lipid-based formulations that reduce nephrotoxicity, but they are costly and require higher dose than Fungizone®. Thus, a cheaper delivery system with reduced AmB toxicity is required. OBJECTIVE To develop and characterize AmB loaded-nanostructured lipid carriers (AmB-loaded NLCs) for IV administration to reduce AmB toxicity. METHODS AmB-loaded NLCs with different solid lipids were prepared by the high-pressure homogenization technique. Their physicochemical properties and the drug release profile were examined. The molecular structure of AmB, antifungal and hemolysis activities of developed AmB-loaded NLCs were also evaluated. RESULTS AmB-loaded NLCs ~110 to ~140 nm in diameter were successfully produced with a zeta potential of ~-19 mV and entrapment efficiency of ~75%. In vitro release showed fast release characteristics. AmB-loaded NLCs could reduce the AmB molecular aggregation as evident from the absorbance ratio of the first to the fourth peak showing a partial aggregation of AmB. This result suggested that AmB-loaded NLCs could offer less nephrotoxicity compared to Fungizone®. In vitro antifungal activity of AmB-loaded NLCs showed a minimum inhibitory concentration of 0.25 µgmL-1. CONCLUSION AmB-loaded NLCs present high potential carriers for effective IV treatment with prolonged circulation time and reduced toxicity.
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Affiliation(s)
- Pataranapa Nimtrakul
- Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok 6500, Thailand
| | - Waree Tiyaboonchai
- Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok 6500, Thailand
| | - Supaporn Lamlertthon
- Centre of excellence in Fungal Research and Department of Microbiology and Parasitology, Faculty of Medical Science, Naresuan University, Phitsanulok 6500, Thailand
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170
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Nishimura S, Matsumori N. Chemical diversity and mode of action of natural products targeting lipids in the eukaryotic cell membrane. Nat Prod Rep 2020; 37:677-702. [PMID: 32022056 DOI: 10.1039/c9np00059c] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Covering: up to 2019Nature furnishes bioactive compounds (natural products) with complex chemical structures, yet with simple, sophisticated molecular mechanisms. When natural products exhibit their activities in cells or bodies, they first have to bind or react with a target molecule in/on the cell. The cell membrane is a major target for bioactive compounds. Recently, our understanding of the molecular mechanism of interactions between natural products and membrane lipids progressed with the aid of newly-developed analytical methods. New technology reconnects old compounds with membrane lipids, while new membrane-targeting molecules are being discovered through the screening for antimicrobial potential of natural products. This review article focuses on natural products that bind to eukaryotic membrane lipids, and includes clinically important molecules and key research tools. The chemical diversity of membrane-targeting natural products and the molecular basis of lipid recognition are described. The history of how their mechanism was unveiled, and how these natural products are used in research are also mentioned.
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Affiliation(s)
- Shinichi Nishimura
- Department of Biotechnology, Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo 113-8657, Japan.
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171
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Sokolov SS, Vorobeva MA, Smirnova AI, Smirnova EA, Trushina NI, Galkina KV, Severin FF, Knorre DA. LAM Genes Contribute to Environmental Stress Tolerance but Sensibilize Yeast Cells to Azoles. Front Microbiol 2020; 11:38. [PMID: 32047490 PMCID: PMC6997477 DOI: 10.3389/fmicb.2020.00038] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 01/09/2020] [Indexed: 11/25/2022] Open
Abstract
Lam proteins transport sterols between the membranes of different cellular compartments. In Saccharomyces cerevisiae, the LAM gene family consists of three pairs of paralogs. Because the function of paralogous genes can be redundant, the phenotypes of only a small number of LAM gene deletions have been reported; thus, the role of these genes in yeast physiology is still unclear. Here, we surveyed the phenotypes of double and quadruple deletants of paralogous LAM2(YSP2)/LAM4 and LAM1(YSP1)/LAM3(SIP3) genes that encode proteins localized in the junctions of the plasma membrane and endoplasmic reticulum. The quadruple deletant showed increased sterol content and a strong decrease in ethanol, heat shock and high osmolarity resistance. Surprisingly, the quadruple deletant and LAM2/LAM4 double deletion strain showed increased tolerance to the azole antifungals clotrimazole and miconazole. This effect was not associated with an increased rate of ABC-transporter substrate efflux. Possibly, increased sterol pool in the LAM deletion strains postpones the effect of azoles on cell growth. Alternatively, LAM deletions might alleviate the toxic effect of sterols as Lam proteins can transport toxic sterol biosynthesis intermediates into membrane compartments that are sensitive to these compounds. Our findings reveal novel biological roles of LAM genes in stress tolerance and suggest that mutations in these genes may confer upregulation of a mechanism that provides resistance to azole antifungals in pathogenic fungi.
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Affiliation(s)
- Svyatoslav S Sokolov
- Department of Molecular Energetics of Microorganisms, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Margarita A Vorobeva
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Alexandra I Smirnova
- Department of Molecular Energetics of Microorganisms, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.,Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Ekaterina A Smirnova
- Department of Molecular Energetics of Microorganisms, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Nataliya I Trushina
- Department of Molecular Energetics of Microorganisms, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.,Department of Neurobiology, University of Osnabrück, Osnabrück, Germany
| | - Kseniia V Galkina
- Department of Molecular Energetics of Microorganisms, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.,Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Fedor F Severin
- Department of Molecular Energetics of Microorganisms, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Dmitry A Knorre
- Department of Molecular Energetics of Microorganisms, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.,Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, Russia
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172
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Oxadiazolylthiazoles as novel and selective antifungal agents. Eur J Med Chem 2020; 189:112046. [PMID: 31962263 DOI: 10.1016/j.ejmech.2020.112046] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Revised: 12/20/2019] [Accepted: 01/06/2020] [Indexed: 12/12/2022]
Abstract
Studying the structure-activity relationships (SAR) of oxadiazolylthiazole antibiotics unexpectedly led us to identify ethylenediamine- and propylenediamine-analogs as potential antimycotic novel lead structures. Replacement of the ethylenediamine moiety for the lead compound 7 with cis-diaminocyclohexyl group (compound 18) significantly enhanced the antifungal activity. In addition to the high safety margin of 18 against mammalian cells, it showed highly selective broad-spectrum activity against fungal cells without inhibiting the human normal microbiota. The antifungal activity of 18 was investigated against 20 drug-resistant clinically important fungi, including Candida species, Cryptococcus, and Aspergillus fumigatus strains. In addition to the low MIC values that mostly ranged between 0.125 and 2.0 μg/mL, compound 18 outperformed fluconazole in disrupting mature Candida biofilm.
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173
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Caplan T, Lorente-Macías Á, Stogios PJ, Evdokimova E, Hyde S, Wellington MA, Liston S, Iyer KR, Puumala E, Shekhar-Guturja T, Robbins N, Savchenko A, Krysan DJ, Whitesell L, Zuercher WJ, Cowen LE. Overcoming Fungal Echinocandin Resistance through Inhibition of the Non-essential Stress Kinase Yck2. Cell Chem Biol 2020; 27:269-282.e5. [PMID: 31924499 DOI: 10.1016/j.chembiol.2019.12.008] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 11/20/2019] [Accepted: 12/17/2019] [Indexed: 01/12/2023]
Abstract
New strategies are urgently needed to counter the threat to human health posed by drug-resistant fungi. To explore an as-yet unexploited target space for antifungals, we screened a library of protein kinase inhibitors for the ability to reverse resistance of the most common human fungal pathogen, Candida albicans, to caspofungin, a widely used antifungal. This screen identified multiple 2,3-aryl-pyrazolopyridine scaffold compounds capable of restoring caspofungin sensitivity. Using chemical genomic, biochemical, and structural approaches, we established the target for our most potent compound as Yck2, a casein kinase 1 family member. Combination of this compound with caspofungin eradicated drug-resistant C. albicans infection while sparing co-cultured human cells. In mice, genetic depletion of YCK2 caused an ∼3-log10 decline in fungal burden in a model of systemic caspofungin-resistant C. albicans infection. Structural insights and our tool compound's profile in culture support targeting the Yck2 kinase function as a broadly active antifungal strategy.
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Affiliation(s)
- Tavia Caplan
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Álvaro Lorente-Macías
- Structural Genomics Consortium, Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Medicinal & Organic Chemistry and Excellence Research Unit of "Chemistry Applied to Biomedicine and the Environment", Faculty of Pharmacy, University of Granada, Campus de Cartuja s/n, 18071 Granada, Spain
| | - Peter J Stogios
- Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5G 1M1, Canada; Center for Structural Genomics of Infectious Diseases (CSGID), Toronto, ON, M5G 1M1, Canada
| | - Elena Evdokimova
- Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5G 1M1, Canada; Center for Structural Genomics of Infectious Diseases (CSGID), Toronto, ON, M5G 1M1, Canada
| | - Sabrina Hyde
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Melanie A Wellington
- Departments of Pediatrics and Microbiology/Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Sean Liston
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Kali R Iyer
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Emily Puumala
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Tanvi Shekhar-Guturja
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Nicole Robbins
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Alexei Savchenko
- Center for Structural Genomics of Infectious Diseases (CSGID), Toronto, ON, M5G 1M1, Canada; Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Damian J Krysan
- Departments of Pediatrics and Microbiology/Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Luke Whitesell
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - William J Zuercher
- Structural Genomics Consortium, Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada.
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174
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Johnston EJ, Moses T, Rosser SJ. The wide-ranging phenotypes of ergosterol biosynthesis mutants, and implications for microbial cell factories. Yeast 2020; 37:27-44. [PMID: 31800968 DOI: 10.1002/yea.3452] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 11/06/2019] [Accepted: 12/02/2019] [Indexed: 01/09/2023] Open
Abstract
Yeast strains have been used extensively as robust microbial cell factories for the production of bulk and fine chemicals, including biofuels (bioethanol), complex pharmaceuticals (antimalarial drug artemisinin and opioid pain killers), flavours, and fragrances (vanillin, nootkatone, and resveratrol). In many cases, it is of benefit to suppress or modify ergosterol biosynthesis during strain engineering, for example, to increase thermotolerance or to increase metabolic flux through an alternate pathway. However, the impact of modifying ergosterol biosynthesis on engineered strains is discussed sparsely in literature, and little attention has been paid to the implications of these modifications on the general health and well-being of yeast. Importantly, yeast with modified sterol content exhibit a wide range of phenotypes, including altered organization and dynamics of plasma membrane, altered susceptibility to chemical treatment, increased tolerance to high temperatures, and reduced tolerance to other stresses such as high ethanol, salt, and solute concentrations. Here, we review the wide-ranging phenotypes of viable Saccharomyces cerevisiae strains with altered sterol content and discuss the implications of these for yeast as microbial cell factories.
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Affiliation(s)
- Emily J Johnston
- School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Tessa Moses
- School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Susan J Rosser
- School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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175
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Ansar SM, Mudalige T. Characterization of doxorubicin liposomal formulations for size-based distribution of drug and excipients using asymmetric-flow field-flow fractionation (AF4) and liquid chromatography-mass spectrometry (LC-MS). Int J Pharm 2020; 574:118906. [DOI: 10.1016/j.ijpharm.2019.118906] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 10/13/2019] [Accepted: 11/24/2019] [Indexed: 01/09/2023]
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176
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Faustino C, Pinheiro L. Lipid Systems for the Delivery of Amphotericin B in Antifungal Therapy. Pharmaceutics 2020; 12:pharmaceutics12010029. [PMID: 31906268 PMCID: PMC7023008 DOI: 10.3390/pharmaceutics12010029] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/17/2019] [Accepted: 12/19/2019] [Indexed: 12/31/2022] Open
Abstract
Amphotericin B (AmB), a broad-spectrum polyene antibiotic in the clinic for more than fifty years, remains the gold standard in the treatment of life-threatening invasive fungal infections and visceral leishmaniasis. Due to its poor water solubility and membrane permeability, AmB is conventionally formulated with deoxycholate as a micellar suspension for intravenous administration, but severe infusion-related side effects and nephrotoxicity hamper its therapeutic potential. Lipid-based formulations, such as liposomal AmB, have been developed which significantly reduce the toxic side effects of the drug. However, their high cost and the need for parenteral administration limit their widespread use. Therefore, delivery systems that can retain or even enhance antimicrobial efficacy while simultaneously reducing AmB adverse events are an active area of research. Among those, lipid systems have been extensively investigated due to the high affinity of AmB for binding lipids. The development of a safe and cost-effective oral formulation able to improve drug accessibility would be a major breakthrough, and several lipid systems for the oral delivery of AmB are currently under development. This review summarizes recent advances in lipid-based systems for targeted delivery of AmB focusing on non-parenteral nanoparticulate formulations mainly investigated over the last five years and highlighting those that are currently in clinical trials.
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Affiliation(s)
| | - Lídia Pinheiro
- Correspondence: ; Tel.: +351-21-7946-400; Fax: +351-21-7946-470
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177
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Low ZJ, Xiong J, Xie Y, Ma GL, Saw H, Thi Tran H, Wong SL, Pang LM, Fong J, Lu P, Hu JF, Yang L, Miao Y, Liang ZX. Discovery, biosynthesis and antifungal mechanism of the polyene-polyol meijiemycin. Chem Commun (Camb) 2019; 56:822-825. [PMID: 31848534 DOI: 10.1039/c9cc08908j] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Produced by a newly isolated Streptomycetes strain, meijiemycin is a gigantic linear polyene-polyol that exhibits structural features not seen in other members of the polyene-polyol family. We propose a biosynthetic mechanism and demonstrate that meijiemycin inhibits hyphal growth by inducing the aggregation of ergosterol and restructuring of the fungal plasma membrane.
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Affiliation(s)
- Zhen Jie Low
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
| | - Juan Xiong
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore. and School of Pharmacy, Fudan University, Shanghai, China
| | - Ying Xie
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
| | - Guang-Lei Ma
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
| | - Howard Saw
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
| | - Hoa Thi Tran
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
| | - Soo Lin Wong
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
| | - Li Mei Pang
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
| | - July Fong
- The Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, 637551, Singapore
| | - Peng Lu
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
| | - Jin-Feng Hu
- School of Pharmacy, Fudan University, Shanghai, China
| | - Liang Yang
- School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Yansong Miao
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
| | - Zhao-Xun Liang
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore. and The Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, 637551, Singapore
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178
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Abstract
Aspergillus fumigatus is a saprotrophic fungus; its primary habitat is the soil. In its ecological niche, the fungus has learned how to adapt and proliferate in hostile environments. This capacity has helped the fungus to resist and survive against human host defenses and, further, to be responsible for one of the most devastating lung infections in terms of morbidity and mortality. In this review, we will provide (i) a description of the biological cycle of A. fumigatus; (ii) a historical perspective of the spectrum of aspergillus disease and the current epidemiological status of these infections; (iii) an analysis of the modes of immune response against Aspergillus in immunocompetent and immunocompromised patients; (iv) an understanding of the pathways responsible for fungal virulence and their host molecular targets, with a specific focus on the cell wall; (v) the current status of the diagnosis of different clinical syndromes; and (vi) an overview of the available antifungal armamentarium and the therapeutic strategies in the clinical context. In addition, the emergence of new concepts, such as nutritional immunity and the integration and rewiring of multiple fungal metabolic activities occurring during lung invasion, has helped us to redefine the opportunistic pathogenesis of A. fumigatus.
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Affiliation(s)
- Jean-Paul Latgé
- School of Medicine, University of Crete, Heraklion, Crete, Greece
| | - Georgios Chamilos
- School of Medicine, University of Crete, Heraklion, Crete, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, Heraklion, Crete, Greece
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179
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Yamamoto T, Umegawa Y, Tsuchikawa H, Hanashima S, Matsumori N, Funahashi K, Seo S, Shinoda W, Murata M. The Amphotericin B-Ergosterol Complex Spans a Lipid Bilayer as a Single-Length Assembly. Biochemistry 2019; 58:5188-5196. [PMID: 31793296 DOI: 10.1021/acs.biochem.9b00835] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Amphotericin B (AmB) is a polyene macrolide antibiotic clinically used as an antifungal drug. Its preferential complexation with ergosterol (Erg), the major sterol of fungal membranes, leads to the formation of a barrel-stave-like ion channel across a lipid bilayer. To gain a better understanding of the mechanism of action, the mode of lipid bilayer spanning provides essential information. However, because of the lack of methodologies to observe it directly, it has not been revealed for the Erg-containing channel assembly for many years. In this study, we disclosed that the AmB-Erg complex spans a lipid bilayer with a single-molecule length, using solid-state nuclear magnetic resonance (NMR) experiments. Paramagnetic relaxation enhancement by Mn2+ residing near the surface of lipid bilayers induced the depth-dependent decay of 13C NMR signals for individual carbon atoms of AmB. We found that both terminal segments, the 41-COOH group and C38-C40 methyl groups, come close to the lipid bilayer surfaces, suggesting that the AmB-Erg complex spans a palmitoyloleoylphosphatidylcholine (POPC) bilayer with a single-molecule length. Molecular dynamics simulation experiments further confirmed the stabilization of the AmB-Erg complex as a single-length spanning complex. These results provide experimental evidence of the single-length complex incorporated in the membrane by making thinner a POPC-Erg bilayer that mimics fungal membranes.
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Affiliation(s)
- Tomoya Yamamoto
- Department of Chemistry, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan.,Project Research Center for Fundamental Sciences, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan
| | - Yuichi Umegawa
- Department of Chemistry, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan.,Project Research Center for Fundamental Sciences, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan
| | - Hiroshi Tsuchikawa
- Department of Chemistry, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan
| | - Shinya Hanashima
- Department of Chemistry, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan
| | - Nobuaki Matsumori
- Department of Chemistry, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan.,Department of Chemistry, Graduate School of Science , Kyushu University , Fukuoka 819-0395 , Japan
| | - Kosuke Funahashi
- Department of Materials Chemistry , Nagoya University , Nagoya 464-8603 , Japan
| | - Sangjae Seo
- Department of Materials Chemistry , Nagoya University , Nagoya 464-8603 , Japan
| | - Wataru Shinoda
- Department of Materials Chemistry , Nagoya University , Nagoya 464-8603 , Japan
| | - Michio Murata
- Department of Chemistry, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan
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180
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Banshoya K, Kaneo Y, Tanaka T, Yamamoto S, Maeda H. Synthesis and evaluation of styrene-maleic acid copolymer conjugated amphotericin B. Int J Pharm 2019; 572:118719. [DOI: 10.1016/j.ijpharm.2019.118719] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 09/03/2019] [Accepted: 09/19/2019] [Indexed: 11/30/2022]
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181
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Wu A, Grela E, Wójtowicz K, Filipczak N, Hamon Y, Luchowski R, Grudziński W, Raducka-Jaszul O, Gagoś M, Szczepaniak A, Chimini G, Gruszecki WI, Trombik T. ABCA1 transporter reduces amphotericin B cytotoxicity in mammalian cells. Cell Mol Life Sci 2019; 76:4979-4994. [PMID: 31134303 PMCID: PMC6881254 DOI: 10.1007/s00018-019-03154-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 05/07/2019] [Accepted: 05/16/2019] [Indexed: 01/20/2023]
Abstract
Amphotericin B (AmB) belongs to a group of polyene antibiotics commonly used in the treatment of systemic mycotic infections. A widely accepted mechanism of action of AmB is based on the formation of an oligomeric pore structure within the plasma membrane (PM) by interaction with membrane sterols. Although AmB binds preferentially to ergosterol, it can also bind to cholesterol in the mammalian PM and cause severe cellular toxicity. The lipid content and its lateral organization at the cell PM appear to be significant for AmB binding. Several ATP-binding cassette (ABC) transporters, including ABCA1, play a crucial role in lipid translocation, cholesterol redistribution and efflux. Here, we demonstrate that cells expressing ABCA1 are more resistant to AmB treatment, while cells lacking ABCA1 expression or expressing non-active ABCA1MM mutant display increased sensitivity. Further, a FLIM analysis of AmB-treated cells reveals a fraction of the antibiotic molecules, characterized by relatively high fluorescence lifetimes (> 6 ns), involved in formation of bulk cholesterol-AmB structures at the surface of ABCA1-expressing cells. Finally, lowering the cellular cholesterol content abolishes resistance of ABCA1-expressing cells to AmB. Therefore, we propose that ABCA1-mediated cholesterol efflux from cells induces formation of bulk cholesterol-AmB structures at the cell surface, preventing AmB cytotoxicity.
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Affiliation(s)
- A Wu
- Faculty of Biotechnology, University of Wroclaw, 50-383, Wrocław, Poland
| | - E Grela
- Department of Biophysics, Institute of Physics, Maria Curie-Sklodowska University, 20-031, Lublin, Poland
| | - K Wójtowicz
- Faculty of Biotechnology, University of Wroclaw, 50-383, Wrocław, Poland
| | - N Filipczak
- Faculty of Biotechnology, University of Wroclaw, 50-383, Wrocław, Poland
| | - Y Hamon
- Aix Marseille University, CNRS, INSERM, CIML, Marseille, France
| | - R Luchowski
- Department of Biophysics, Institute of Physics, Maria Curie-Sklodowska University, 20-031, Lublin, Poland
| | - W Grudziński
- Department of Biophysics, Institute of Physics, Maria Curie-Sklodowska University, 20-031, Lublin, Poland
| | - O Raducka-Jaszul
- Faculty of Biotechnology, University of Wroclaw, 50-383, Wrocław, Poland
| | - M Gagoś
- Department of Cell Biology, Maria Curie-Skłodowska University, 20-033, Lublin, Poland
| | - A Szczepaniak
- Faculty of Biotechnology, University of Wroclaw, 50-383, Wrocław, Poland
| | - G Chimini
- Aix Marseille University, CNRS, INSERM, CIML, Marseille, France
| | - W I Gruszecki
- Department of Biophysics, Institute of Physics, Maria Curie-Sklodowska University, 20-031, Lublin, Poland
| | - T Trombik
- Faculty of Biotechnology, University of Wroclaw, 50-383, Wrocław, Poland.
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182
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Modes of the antibiotic activity of amphotericin B against Candida albicans. Sci Rep 2019; 9:17029. [PMID: 31745151 PMCID: PMC6864243 DOI: 10.1038/s41598-019-53517-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 10/28/2019] [Indexed: 02/07/2023] Open
Abstract
Amphotericin B is an antibiotic used as the “gold standard” in the treatment of life-threatening fungal infections. Several molecular mechanisms have been proposed to explain exceptionally high effectiveness of amphotericin B in combating fungi. In the present work, we apply fluorescence lifetime imaging microscopy to track, step by step, modes of the toxic activity of amphotericin B towards a clinical strain of Candida albicans. The images recorded reveal that the antibiotic binds to cells in the form of the small aggregates characterized by a relatively short fluorescence lifetime (0.2 ns). Amphotericin B binds preferentially to the cell walls of mature cells but also to the plasma membranes of the daughter cells at the budding stage. The images recorded with the application of a scanning electron microscopy show that the antibiotic interferes with the formation of functional cell walls of such young cells. The results of imaging reveal the formation of the amphotericin B-rich extramembranous structures and also binding of the drug molecules into the cell membranes and penetration into the cells. These two modes of action of amphotericin B are observed in the time scale of minutes.
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183
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Sugiyama R, Nakatani T, Nishimura S, Takenaka K, Ozaki T, Asamizu S, Onaka H, Kakeya H. Chemical Interactions of Cryptic Actinomycete Metabolite 5‐Alkyl‐1,2,3,4‐tetrahydroquinolines through Aggregate Formation. Angew Chem Int Ed Engl 2019; 58:13486-13491. [DOI: 10.1002/anie.201905970] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Indexed: 12/19/2022]
Affiliation(s)
- Ryosuke Sugiyama
- Department of System Chemotherapy and Molecular SciencesDivision of Bioinformatics and Chemical GenomicsGraduate School of Pharmaceutical SciencesKyoto University, Sakyo-ku Kyoto 606-8501 Japan
- Present address: Department of PharmacyNational University of Singapore 18 Science Drive 4 Singapore 117543 Singapore
| | - Takahiro Nakatani
- Department of System Chemotherapy and Molecular SciencesDivision of Bioinformatics and Chemical GenomicsGraduate School of Pharmaceutical SciencesKyoto University, Sakyo-ku Kyoto 606-8501 Japan
| | - Shinichi Nishimura
- Department of System Chemotherapy and Molecular SciencesDivision of Bioinformatics and Chemical GenomicsGraduate School of Pharmaceutical SciencesKyoto University, Sakyo-ku Kyoto 606-8501 Japan
- Department of BiotechnologyGraduate School of Agricultural and Life SciencesThe University of Tokyo Bunkyo-ku Tokyo 113-8657 Japan
- Collaborative Research Institute for Innovative MicrobiologyThe University of Tokyo 1-1-1 Yayoi, Bunkyo-ku Tokyo 113-8657 Japan
| | - Kei Takenaka
- Department of System Chemotherapy and Molecular SciencesDivision of Bioinformatics and Chemical GenomicsGraduate School of Pharmaceutical SciencesKyoto University, Sakyo-ku Kyoto 606-8501 Japan
| | - Taro Ozaki
- Department of BiotechnologyGraduate School of Agricultural and Life SciencesThe University of Tokyo Bunkyo-ku Tokyo 113-8657 Japan
- Present address: Department of ChemistryFaculty of ScienceHokkaido University Sapporo 060-0810 Hokkaido Japan
| | - Shumpei Asamizu
- Department of BiotechnologyGraduate School of Agricultural and Life SciencesThe University of Tokyo Bunkyo-ku Tokyo 113-8657 Japan
- Collaborative Research Institute for Innovative MicrobiologyThe University of Tokyo 1-1-1 Yayoi, Bunkyo-ku Tokyo 113-8657 Japan
| | - Hiroyasu Onaka
- Department of BiotechnologyGraduate School of Agricultural and Life SciencesThe University of Tokyo Bunkyo-ku Tokyo 113-8657 Japan
- Collaborative Research Institute for Innovative MicrobiologyThe University of Tokyo 1-1-1 Yayoi, Bunkyo-ku Tokyo 113-8657 Japan
| | - Hideaki Kakeya
- Department of System Chemotherapy and Molecular SciencesDivision of Bioinformatics and Chemical GenomicsGraduate School of Pharmaceutical SciencesKyoto University, Sakyo-ku Kyoto 606-8501 Japan
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184
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A Novel Role of Fungal Type I Myosin in Regulating Membrane Properties and Its Association with d-Amino Acid Utilization in Cryptococcus gattii. mBio 2019; 10:mBio.01867-19. [PMID: 31455652 PMCID: PMC6712397 DOI: 10.1128/mbio.01867-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Cryptococcus gattii, one of the etiological agents of cryptococcosis, can be distinguished from its sister species Cryptococcus neoformans by growth on d-amino acids. C. gattiiMYO5 affected the growth of C. gattii on d-amino acids. The myo5Δ cells accumulated high levels of various substrates from outside the cells, and excessively accumulated d-amino acids appeared to have caused toxicity in the myo5Δ cells. We provide evidence on the alteration of membrane properties in the myo5Δ mutants. Additionally, alteration in the myo5Δ membrane permeability causing higher substrate accumulation is associated with the changes in the sterol distribution. Furthermore, myosin-I in three other yeasts also manifested a similar role in substrate accumulation. Thus, while fungal myosin-I may function as a classical myosin-I, it has hitherto unknown additional roles in regulating membrane permeability. Since deletion of fungal myosin-I causes significantly elevated susceptibility to multiple antifungal drugs, it could serve as an effective target for augmentation of fungal therapy. We found a novel role of Myo5, a type I myosin (myosin-I), and its fortuitous association with d-amino acid utilization in Cryptococcus gattii. Myo5 colocalized with actin cortical patches and was required for endocytosis. Interestingly, the myo5Δ mutant accumulated high levels of d-proline and d-alanine which caused toxicity in C. gattii cells. The myo5Δ mutant also accumulated a large set of substrates, such as membrane-permeant as well as non-membrane-permeant dyes, l-proline, l-alanine, and flucytosine intracellularly. Furthermore, the efflux rate of fluorescein was significantly increased in the myo5Δ mutant. Importantly, the endocytic defect of the myo5Δ mutant did not affect the localization of the proline permease and flucytosine transporter. These data indicate that the substrate accumulation phenotype is not solely due to a defect in endocytosis, but the membrane properties may have been altered in the myo5Δ mutant. Consistent with this, the sterol staining pattern of the myo5Δ mutant was different from that of the wild type, and the mutant was hypersensitive to amphotericin B. It appears that the changes in sterol distribution may have caused altered membrane permeability in the myo5Δ mutant, allowing increased accumulation of substrate. Moreover, myosin-I mutants generated in several other yeast species displayed a similar substrate accumulation phenotype. Thus, fungal type I myosin appears to play an important role in regulating membrane permeability. Although the substrate accumulation phenotype was detected in strains with mutations in the genes involved in actin nucleation, the phenotype was not shared in all endocytic mutants, indicating a complicated relationship between substrate accumulation and endocytosis.
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185
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Van Haute D, Jiang W, Mudalige T. Evaluation of size-based distribution of drug and excipient in amphotericin B liposomal formulation. Int J Pharm 2019; 569:118603. [PMID: 31401296 DOI: 10.1016/j.ijpharm.2019.118603] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 07/10/2019] [Accepted: 08/05/2019] [Indexed: 12/15/2022]
Abstract
Conventional quantitation of drug content in the liposome formulation involves the breakdown of bulk liposomes, which ignores details on the distribution of the active pharmaceutical ingredient (API) and excipients in liposomes of different sizes. The objective of this study is to develop an analytical method which can separate the liposomes into different sizes and obtain information of the drug and excipient distribution in the different sized liposomes. We developed an asymmetric flow field-flow fractionation (AF4) method for size-based separation of AmBisome, an amphotericin B liposomal formulation, and a high-performance liquid chromatography ultraviolet-visible and charged aerosol detection (HPLC-UV-CAD) method for simultaneous quantitation of the API (Amphotericin B) and the lipid excipients [1,2-Distearoyl-sn-glycero-3-phosphoglycerol (DSPG), hydrogenated soy phosphatidylcholine (HSPC), and cholesterol]. The measured drug content in the bulk liposome formulation was consistent with the drug product labeling. Liposomes were separated using AF4 into eleven size fractions and the liposomes particles sizes of each fraction were measured with nanoparticle tracking analysis. The drug to total lipid ratios in fractionated liposomes increased from 0.1 to 0.45 when the liposome size increased from 75 nm to 124 nm, while the lipid composition remained constant throughout the fractioned size range (cholesterol:DSPG, 0.7 and HSPC:DSPG, 0.3). These study results suggest that, for liposomal formulations of Amphotericin B in liposomes, the drug to lipid ratio increases with the size of the liposomes. This new analytical method provided a more in-depth characterization of liposomes, i.e., determining drug and excipient distributions in different sizes of liposomes, in a more efficient manner with more specific size-based composition information.
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Affiliation(s)
- Desiree Van Haute
- Arkansas Laboratory, Office of Regulatory Science, Office of Regulatory Affairs, US Food and Drug Administration, Jefferson, AR 72079, United States
| | - Wenlei Jiang
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD 20993, United States.
| | - Thilak Mudalige
- Arkansas Laboratory, Office of Regulatory Science, Office of Regulatory Affairs, US Food and Drug Administration, Jefferson, AR 72079, United States.
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186
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Sugiyama R, Nakatani T, Nishimura S, Takenaka K, Ozaki T, Asamizu S, Onaka H, Kakeya H. Chemical Interactions of Cryptic Actinomycete Metabolite 5‐Alkyl‐1,2,3,4‐tetrahydroquinolines through Aggregate Formation. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201905970] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ryosuke Sugiyama
- Department of System Chemotherapy and Molecular SciencesDivision of Bioinformatics and Chemical GenomicsGraduate School of Pharmaceutical SciencesKyoto University, Sakyo-ku Kyoto 606-8501 Japan
- Present address: Department of PharmacyNational University of Singapore 18 Science Drive 4 Singapore 117543 Singapore
| | - Takahiro Nakatani
- Department of System Chemotherapy and Molecular SciencesDivision of Bioinformatics and Chemical GenomicsGraduate School of Pharmaceutical SciencesKyoto University, Sakyo-ku Kyoto 606-8501 Japan
| | - Shinichi Nishimura
- Department of System Chemotherapy and Molecular SciencesDivision of Bioinformatics and Chemical GenomicsGraduate School of Pharmaceutical SciencesKyoto University, Sakyo-ku Kyoto 606-8501 Japan
- Department of BiotechnologyGraduate School of Agricultural and Life SciencesThe University of Tokyo Bunkyo-ku Tokyo 113-8657 Japan
- Collaborative Research Institute for Innovative MicrobiologyThe University of Tokyo 1-1-1 Yayoi, Bunkyo-ku Tokyo 113-8657 Japan
| | - Kei Takenaka
- Department of System Chemotherapy and Molecular SciencesDivision of Bioinformatics and Chemical GenomicsGraduate School of Pharmaceutical SciencesKyoto University, Sakyo-ku Kyoto 606-8501 Japan
| | - Taro Ozaki
- Department of BiotechnologyGraduate School of Agricultural and Life SciencesThe University of Tokyo Bunkyo-ku Tokyo 113-8657 Japan
- Present address: Department of ChemistryFaculty of ScienceHokkaido University Sapporo 060-0810 Hokkaido Japan
| | - Shumpei Asamizu
- Department of BiotechnologyGraduate School of Agricultural and Life SciencesThe University of Tokyo Bunkyo-ku Tokyo 113-8657 Japan
- Collaborative Research Institute for Innovative MicrobiologyThe University of Tokyo 1-1-1 Yayoi, Bunkyo-ku Tokyo 113-8657 Japan
| | - Hiroyasu Onaka
- Department of BiotechnologyGraduate School of Agricultural and Life SciencesThe University of Tokyo Bunkyo-ku Tokyo 113-8657 Japan
- Collaborative Research Institute for Innovative MicrobiologyThe University of Tokyo 1-1-1 Yayoi, Bunkyo-ku Tokyo 113-8657 Japan
| | - Hideaki Kakeya
- Department of System Chemotherapy and Molecular SciencesDivision of Bioinformatics and Chemical GenomicsGraduate School of Pharmaceutical SciencesKyoto University, Sakyo-ku Kyoto 606-8501 Japan
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187
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Alfatah M, Wong JH, Kong KW, Utama F, Hoon S, Arumugam P. Chemical-genetic interaction landscape of mono-(2-ethylhexyl)-phthalate using chemogenomic profiling in yeast. CHEMOSPHERE 2019; 228:219-231. [PMID: 31029968 DOI: 10.1016/j.chemosphere.2019.04.100] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 03/07/2019] [Accepted: 04/13/2019] [Indexed: 06/09/2023]
Abstract
Integration of chemical-genetic interaction data with biological functions provides a mechanistic understanding of how toxic compounds affect cells. Mono-(2-ethylhexyl)-phthalate (MEHP) is an active metabolite of di-(2-ethylhexyl)-phthalate (DEHP), a commonly used plasticizer. MEHP adversely affects human health causing hepatotoxicity and reproductive toxicity. How MEHP affects cellular physiology is not fully understood. We utilized a genome-wide competitive fitness-based assay called 'chemogenomic profiling' to determine the genetic interaction map of MEHP in Saccharomyces cerevisiae. Gene Ontology enrichment analysis of 218 genes that provide resistance to MEHP indicated that MEHP affects seven cellular processes namely: (1) cellular amino acid biosynthetic process, (2) sterol biosynthetic process, (3) cellular transport, (4) transcriptional and translational regulation, (5) protein glycosylation, (6) cytokinesis and cell morphogenesis and (7) ionic homeostasis. We show that MEHP protects yeast cells from membrane perturbing agents such as amphotericin B, dihydrosphingosine and phytosphingosine. Moreover, we also demonstrate that MEHP compromises the integrity of the yeast plasma membrane and cell wall. Our work provides a basis for further investigation of MEHP toxicity in humans.
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Affiliation(s)
- Mohammad Alfatah
- Bioinformatics Institute, 30 Biopolis Street, #07-01, Matrix, Singapore 138671, Singapore.
| | - Jin Huei Wong
- Bioinformatics Institute, 30 Biopolis Street, #07-01, Matrix, Singapore 138671, Singapore
| | - Kiat Whye Kong
- Molecular Engineering Laboratory, 61 Biopolis Drive, #03-12 Proteos, Singapore 13867, Singapore
| | - Felix Utama
- School of Chemical and Life Sciences, Singapore Polytechnic, 500 Dover Road, Singapore 139651, Singapore
| | - Shawn Hoon
- Molecular Engineering Laboratory, 61 Biopolis Drive, #03-12 Proteos, Singapore 13867, Singapore
| | - Prakash Arumugam
- Bioinformatics Institute, 30 Biopolis Street, #07-01, Matrix, Singapore 138671, Singapore.
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188
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Prasad R, Nair R, Banerjee A. Multidrug transporters of Candida species in clinical azole resistance. Fungal Genet Biol 2019; 132:103252. [PMID: 31302289 DOI: 10.1016/j.fgb.2019.103252] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/07/2019] [Accepted: 07/08/2019] [Indexed: 11/30/2022]
Abstract
Over-expression of the human P-glycoprotein (P-gp) in tumor cells is a classic example of an ABC protein serving as a hindrance to effective chemotherapy. The existence of proteins homologous to P-gp in organisms encompassing the entire living kingdom highlights extrusion of drugs as a general mechanism of multidrug resistance. Infections caused by opportunistic human fungal pathogens such as Candida species are very common and has intensified in recent years. The typical hosts, who possess suppressed immune systems due to conditions such as HIV and transplantation surgery etc., are prone to fungal infections. Prolonged chemotherapy induces fungal cells to eventually develop tolerance to most of the antifungals currently in clinical use. Amongst other prominent mechanisms of antifungal resistance such as manipulation of the drug target, rapid efflux achieved through overexpression of multidrug transporters has emerged as a major resistance mechanism for azoles. Herein, the azole-resistant clinical isolates of Candida species utilize a few select efflux pump proteins belonging to the ABC and MFS superfamilies, to deter the toxic accumulation of therapeutic azoles and thus, facilitating cell survival. In this article, we summarize and discuss the clinically relevant mechanisms of azole resistance in Candida albicans and non-albicans Candida (NAC) species, specifically highlighting the role of multidrug efflux proteins in the phenomenon.
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Affiliation(s)
- Rajendra Prasad
- Amity Institute of Integrative Science and Health and Amity Institute of Biotechnology, Amity University Haryana, Gurgaon, Haryana, India.
| | - Remya Nair
- Amity Institute of Integrative Science and Health and Amity Institute of Biotechnology, Amity University Haryana, Gurgaon, Haryana, India
| | - Atanu Banerjee
- Amity Institute of Integrative Science and Health and Amity Institute of Biotechnology, Amity University Haryana, Gurgaon, Haryana, India.
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189
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Valentine M, Benadé E, Mouton M, Khan W, Botha A. Binary interactions between the yeast Candida albicans and two gut-associated Bacteroides species. Microb Pathog 2019; 135:103619. [PMID: 31291601 DOI: 10.1016/j.micpath.2019.103619] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 05/11/2019] [Accepted: 07/06/2019] [Indexed: 01/15/2023]
Abstract
The yeast Candida albicans forms part of the natural gut microbiota of healthy human individuals and its interactions with other microbial symbionts can impact host well-being. We therefore studied binary interactions between potentially pathogenic representatives of the gut-associated bacterial genus Bacteroides and C. albicans using anaerobic bacteria/yeast co-cultures prepared with a quarter-strength brain heart infusion (¼ BHI; 9.25 g/l) broth. We found that, except for minor changes observed in the cell numbers of one out of four C. albicans strains tested, yeast growth was largely unaffected by the presence of the bacteria. In contrast, growth of Bacteroides fragilis NCTC 9343 and Bacteroides vulgatus ATCC 8482 was significantly enhanced in the presence of C. albicans. Supplementation of Bacteroides monocultures with dead Candida albicans CAB 392 cells, containing intact outer cell wall mannan layers, resulted in increased bacterial concentrations. Subsequent culturing of the Bacteroides strains in a liquid minimal medium supplemented with candidal mannan demonstrated that B. vulgatus ATCC 8482, unlike B. fragilis NCTC 9343, utilized the mannan. Furthermore, by reducing the initial oxygen levels in monocultures prepared with ¼ BHI broth, bacterial numbers were significantly enhanced compared to in monocultures prepared with ¼ BHI broth not supplemented with the reducing agent l-cysteine hydrochloride. This suggests that C. albicans can stimulate Bacteroides growth via aerobic respiration and/or antioxidant production. The cell-free supernatant of 24-h-old C. albicans CAB 392 monocultures was also found to increase Bacteroides growth and chloramphenicol sensitivity.
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Affiliation(s)
- Marisa Valentine
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Eliska Benadé
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Marnel Mouton
- Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa
| | - Wesaal Khan
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Alfred Botha
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa.
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190
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Butassi E, Svetaz LA, Zhou S, Wolfender JL, Cortés JCG, Ribas JC, Díaz C, Palacio JPD, Vicente F, Zacchino SA. The antifungal activity and mechanisms of action of quantified extracts from berries, leaves and roots of Phytolacca tetramera. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2019; 60:152884. [PMID: 30922815 DOI: 10.1016/j.phymed.2019.152884] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 02/25/2019] [Accepted: 03/09/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Phytolacca tetramera is an endemic plant from Argentina that is currently at serious risk because its environment is subjected to a high anthropic impact. A previous study has shown that berry extracts obtained from this plant display antifungal activity against multiple human-pathogenic fungi when tested with a non-standardized method. Further evidences of the antifungal properties of other parts of the plant and studies of mechanism of antifungal action of the antifungal chemically characterized extracts are required. PURPOSE This study aimed to gain further evidence of the antifungal activity of P. tetramera berry, leaf and root extracts in order to find the most active extract to be developed as an Herbal Medicinal Antifungal Product. The medicinal usefulness of P. tetramera extracts as antifungal agents will serve as an important support to create concience and carry out actions tending to the preservation of this threatened species and its environment. MATERIALS AND METHODS Chemical analysis of all P. tetramera extracts, including quantitation of selected markers, was performed through UHPLC-ESI-MS/MS and UPLC-ESI-MS techniques according to the European Medicines Agency (EMA). The antifungal activity of the quantified extracts was tested with the standardized CLSI microbroth dilution method against Candida spp. Antifungal mechanisms of the most active extract were studied by examination of morphological changes by phase-contrast and fluorescence microscopies and both, cellular and enzymatic assays targeting either the fungal membrane or the cell wall. RESULTS The antifungal activity of twelve P. tetramera extracts was tested against Candida albicans and Candida glabrata. The dichloromethane extract from berries (PtDEb) showed the best activity. Phytolaccagenin (PhytG) and phytolaccoside B (PhytB) were selected as the main active markers for the antifungal P. tetramera extracts. The quantitation of these active markers in all extracts showed that PtDEb possessed the highest amount of PhytG and PhytB. Finally, studies on the mechanism of antifungal action showed that the most active PtDEb extract produces morphological changes compatible with a damage of the cell wall and/or the plasma membrane. Cellular and enzymatic assays showed that PtDEb would not damage the fungal cell wall by itself, but would alter the plasma membrane. In agreement, PtDEb was found to bind to ergosterol, the main sterol of the fungal plasma membrane. CONCLUSION Studies of the anti-Candida activity of P. tetramera extracts led to the selection of PtDEb as the most suitable extract, confirming the antifungal properties of the threatened species P. tetramera. The new data give a valuable reason for the definitive protection of this sp. and its natural environment thus allowing further studies for the future development of an Herbal Medicinal Antifungal Product.
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Affiliation(s)
- Estefanía Butassi
- Área Farmacognosia, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Suipacha 531, 2000 Rosario, Argentina
| | - Laura A Svetaz
- Área Farmacognosia, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Suipacha 531, 2000 Rosario, Argentina
| | - Shuaizhen Zhou
- Natural Products Chemistry Department, & State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, China; School of Pharmaceutical Sciences, EPGL, University of Geneva, University of Lausanne, CMU-Rue Michel-Servet 1, CH-1206 Geneva 4, Switzerland
| | - Jean-Luc Wolfender
- School of Pharmaceutical Sciences, EPGL, University of Geneva, University of Lausanne, CMU-Rue Michel-Servet 1, CH-1206 Geneva 4, Switzerland
| | - Juan C G Cortés
- Instituto de Biología Funcional y Genómica y Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, 37007 Salamanca, Spain
| | - Juan C Ribas
- Instituto de Biología Funcional y Genómica y Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, 37007 Salamanca, Spain
| | - Caridad Díaz
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Parque Tecnológico de Ciencias de la Salud, Avda. del Conocimiento 34, E-18016 Granada, Spain
| | - José Pérez-Del Palacio
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Parque Tecnológico de Ciencias de la Salud, Avda. del Conocimiento 34, E-18016 Granada, Spain
| | - Francisca Vicente
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Parque Tecnológico de Ciencias de la Salud, Avda. del Conocimiento 34, E-18016 Granada, Spain
| | - Susana A Zacchino
- Área Farmacognosia, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Suipacha 531, 2000 Rosario, Argentina.
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191
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Vahedi Shahandashti R, Lass-Flörl C. Antifungal resistance in Aspergillus terreus: A current scenario. Fungal Genet Biol 2019; 131:103247. [PMID: 31247322 DOI: 10.1016/j.fgb.2019.103247] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 06/20/2019] [Indexed: 12/31/2022]
Abstract
Invasive aspergillosis caused by intrinsically resistant non-fumigatus Aspergillus species displays a poor outcome in immunocompromised patients. The polyene antifungal amphotericin B (AmB) remains to be "gold standard" in the treatment of invasive fungal infections. Aspergillus terreus is innately resistant to AmB, in vivo and in vitro. Till now, the exact mode of action in polyene resistance is not well understood. This review highlights the underlying molecular basis of AmB resistance in A. terreus, displaying data obtained from AmB susceptible A. terreus and AmB resistant A. terreus strains. The effect of AmB on main cellular and molecular functions such as fungal respiration and stress response pathways will be discussed in detail and resistance mechanisms will be highlighted. The fungal stress response machinery seems to be a major player in the onset of AmB resistance in A. terreus.
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Affiliation(s)
| | - Cornelia Lass-Flörl
- Division of Hygiene and Medical Microbiology, Medical University Innsbruck, Innsbruck, Austria.
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192
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Genomewide Elucidation of Drug Resistance Mechanisms for Systemically Used Antifungal Drugs Amphotericin B, Caspofungin, and Voriconazole in the Budding Yeast. Antimicrob Agents Chemother 2019; 63:AAC.02268-18. [PMID: 31209012 DOI: 10.1128/aac.02268-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 06/03/2019] [Indexed: 12/16/2022] Open
Abstract
There are only a few antifungal drugs used systemically in treatment, and invasive fungal infections that are resistant to these drugs are an emerging problem in health care. In this study, we performed a high-copy-number genomic DNA (gDNA) library screening to find and characterize genes that reduce susceptibility to amphotericin B, caspofungin, and voriconazole in Saccharomyces cerevisiae We identified the PDR16 and PMP3 genes for amphotericin B, the RMD9 and SWH1 genes for caspofungin, and the MRS3 and TRI1 genes for voriconazole. The deletion mutants for PDR16 and PMP3 were drug susceptible, but the other mutants had no apparent susceptibility. Quantitative-PCR analyses suggested that the corresponding drugs upregulated expression of the PDR16, PMP3, SWH1, and MRS3 genes. To further characterize these genes, we also profiled the global expression patterns of the cells after treatment with the antifungals and determined the genes and paths that were up- or downregulated. We also cloned Candida albicans homologs of the PDR16, PMP3, MRS3, and TRI1 genes and expressed them in S. cerevisiae Heterologous expression of Candida homologs also provided reduced drug susceptibility to the budding yeast cells. Our analyses suggest the involvement of new genes in antifungal drug resistance.
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193
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Lu Y, Zhou Z, Mo L, Guo Q, Peng X, Hu T, Zhou X, Ren B, Xu X. Fluphenazine antagonizes with fluconazole but synergizes with amphotericin B in the treatment of candidiasis. Appl Microbiol Biotechnol 2019; 103:6701-6709. [PMID: 31201451 DOI: 10.1007/s00253-019-09960-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/23/2019] [Accepted: 06/01/2019] [Indexed: 02/05/2023]
Abstract
Candida albicans causes a high mortality rate in immunocompromised individuals, but the increased drug resistance challenges the current antifungal therapeutics. Fluphenazine (FPZ), a commonly used antipsychotic medication, can induce the expression of drug efflux pumps in C. albicans and, thus, may interfere with the therapeutic efficacy of antifungals, such as fluconazole (FLC) and amphotericin B (AmB). Here, we investigated the combined effects of FLC/FPZ and AmB/FPZ against C. albicans in vitro and in a systemic candidiasis mouse model. The antifungal activity of FLC was significantly reduced when supplemented with FPZ. The inhibitory effects of FLC on the expression of the Candida virulence-related genes ALS3 and HWP1 were antagonized by FPZ. However, FPZ enhanced the susceptibility of C. albicans to AmB and further downregulated the expression of ALS3 and HWP1 in a synergistic manner with AmB. FPZ also enhanced the gene expression of ERG11, a key gene of the ergosterol biosynthesis pathway that has been associated with the activities of both FLC and AmB. In our mammalian infection model, mice treated with FLC/FPZ showed notably poor living status and increased fungal burden in their kidneys and brains compared with those treated with FLC alone. Conversely, the combined application of AmB/FPZ significantly improved the survival rate, attenuated the weight loss and reduced the organ fungal burdens of the infected mice. These data suggest that FPZ antagonized the therapeutic efficacy of FLC but enhanced the antifungal activity of AmB in the treatment of candidiasis.
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Affiliation(s)
- Yangyu Lu
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, No.14, 3rd Section of Ren Min Nan Rd., Chengdu, 610041, Sichuan, China.,Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Zhiyan Zhou
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, No.14, 3rd Section of Ren Min Nan Rd., Chengdu, 610041, Sichuan, China.,Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Longyi Mo
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, No.14, 3rd Section of Ren Min Nan Rd., Chengdu, 610041, Sichuan, China
| | - Qiang Guo
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, No.14, 3rd Section of Ren Min Nan Rd., Chengdu, 610041, Sichuan, China
| | - Xian Peng
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, No.14, 3rd Section of Ren Min Nan Rd., Chengdu, 610041, Sichuan, China
| | - Tao Hu
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, No.14, 3rd Section of Ren Min Nan Rd., Chengdu, 610041, Sichuan, China.,Department of Preventive Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Xuedong Zhou
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, No.14, 3rd Section of Ren Min Nan Rd., Chengdu, 610041, Sichuan, China.,Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Biao Ren
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, No.14, 3rd Section of Ren Min Nan Rd., Chengdu, 610041, Sichuan, China.
| | - Xin Xu
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, No.14, 3rd Section of Ren Min Nan Rd., Chengdu, 610041, Sichuan, China. .,Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.
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194
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Lee MT, Hung WC, Huang HW. Rhombohedral trap for studying molecular oligomerization in membranes: application to daptomycin. SOFT MATTER 2019; 15:4326-4333. [PMID: 31070654 PMCID: PMC6541503 DOI: 10.1039/c9sm00323a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A persistent problem in the studies of membrane-active peptides, including antimicrobial peptides and pathogenic amyloidal peptides, is the lack of methods for investigating their molecular configurations in membranes. These peptides spontaneously bind to membranes from solutions, and often form oligomers that induce changes of membrane permeability. For antimicrobials, such actions appear to relate to the antimicrobial mechanisms, but for amyloidal peptides, the oligomerization has been linked to neurodegenerative diseases. In many cases, no further understanding of such oligomerization has been achieved due to the lack of structural information. In this article, we will demonstrate a method of trapping such peptide oligomers in a rhombohedral (R) phase of lipid so that the oligomers can be subjected to 3D diffraction analysis. The conditions for forming the R phase and the electron density distribution in the rhombohedral unit cell provide information about peptide-lipid interactions and the molecular size of the trapped oligomer. Such information cannot be obtained from membranes in the planar configuration. For illustration, we apply this method to daptomycin, an FDA-approved antibiotic that attacks membranes containing phosphatidylglycerol, in the presence of calcium ions. We have successfully used the brominated phosphatidylglycerol to perform bromine-atom anomalous diffraction in the rhombohedral phase containing daptomycin and calcium ions. The preliminary results apparently exhibit diffraction data related to daptomycin oligomers. We believe that this method will also be applicable to the difficult problems related to amyloidal peptides, such as amyloid beta of Alzheimer's disease.
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Affiliation(s)
- Ming-Tao Lee
- National Synchrotron Radiation Research Center, Hsinchu, Taiwan
- Department of Physics, National Central University, Jhongli, Taiwan
| | - Wei-Chin Hung
- Department of Physics, R. O. C. Military Academy, Fengshan, Kaohsiung, Taiwan
| | - Huey W. Huang
- Department of Physics and Astronomy, Rice University, Houston TX, USA
- Corresponding address:
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195
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Role of Lipid Composition, Physicochemical Interactions, and Membrane Mechanics in the Molecular Actions of Microbial Cyclic Lipopeptides. J Membr Biol 2019; 252:131-157. [PMID: 31098678 DOI: 10.1007/s00232-019-00067-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 05/02/2019] [Indexed: 10/26/2022]
Abstract
Several experimental and theoretical studies have extensively investigated the effects of a large diversity of antimicrobial peptides (AMPs) on model lipid bilayers and living cells. Many of these peptides disturb cells by forming pores in the plasma membrane that eventually lead to the cell death. The complexity of these peptide-lipid interactions is mainly related to electrostatic, hydrophobic and topological issues of these counterparts. Diverse studies have shed some light on how AMPs act on lipid bilayers composed by different phospholipids, and how mechanical properties of membranes could affect the antimicrobial effects of such compounds. On the other hand, cyclic lipopeptides (cLPs), an important class of microbial secondary metabolites, have received comparatively less attention. Due to their amphipathic structures, cLPs exhibit interesting biological activities including interactions with biofilms, anti-bacterial, anti-fungal, antiviral, and anti-tumoral properties, which deserve more investigation. Understanding how physicochemical properties of lipid bilayers contribute and determining the antagonistic activity of these secondary metabolites over a broad spectrum of microbial pathogens could establish a framework to design and select effective strategies of biological control. This implies unravelling-at the biophysical level-the complex interactions established between cLPs and lipid bilayers. This review presents, in a systematic manner, the diversity of lipidated antibiotics produced by different microorganisms, with a critical analysis of the perturbing actions that have been reported in the literature for this specific set of membrane-active lipopeptides during their interactions with model membranes and in vivo. With an overview on the mechanical properties of lipid bilayers that can be experimentally determined, we also discuss which parameters are relevant in the understanding of those perturbation effects. Finally, we expose in brief, how this knowledge can help to design novel strategies to use these biosurfactants in the agronomic and pharmaceutical industries.
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196
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von Lilienfeld-Toal M, Wagener J, Einsele H, A. Cornely O, Kurzai O. Invasive Fungal Infection. DEUTSCHES ARZTEBLATT INTERNATIONAL 2019; 116:271-278. [PMID: 31159914 PMCID: PMC6549129 DOI: 10.3238/arztebl.2019.0271] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 06/29/2018] [Accepted: 02/14/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND The incidence of invasive fungal infection is approximately 6 cases per 100 000 persons per year. It is estimated that only half of such infections are detected during the patient's lifetime, making this one of the more common overlooked causes of death in intensive-care patients. The low detection rate is due in part to the complexity of the diagnostic work-up, in which the clinical, radiological, and microbiological findings must be considered. Fungi with resistance to antimycotic drugs have been found to be on the rise around the world. METHODS This review is based on pertinent publications retrieved from a selective search in PubMed, with special attention to guidelines on the diagnosis and treatment of invasive fungal infections caused by Candida spp., Aspergillus spp., Mucorales, and Fusarium spp. RESULTS The clinical risk factors for invasive fungal infection include, among others, congenital immune deficiency, protracted (>10 days) marked granulocytopenia (<0.5 x 109/L), allogeneic stem-cell transplantation, and treatment with immunosuppressive drugs or corticosteroids. High-risk groups include patients in intensive care and those with structural pulmonary disease and/or compli- cated influenza. The first line of treatment, supported by the findings of randomized clinical trials, consists of echinocandins for in- fections with Candida spp. (candidemia response rates: 75.6% for anidulafungin vs. 60.2% for fluconazole) and azole antimycotic drugs for infections with Aspergillus spp. (response rates: 52.8% for voriconazole vs. 31.6% for conventional amphotericin B). The recommended first-line treatment also depends on the local epidemiology. This challenge should be met by interdisciplinary collaboration. Therapeutic decision-making should also take account of the often severe undesired effects of antimycotic drugs (including impairment of hepatic and/or renal function) and the numerous interactions that some of them have with other drugs. CONCLUSION Invasive fungal infections are often overlooked in routine hospital care. They should be incorporated into antimicro- bial stewardship programs as an essential component. There is also a pressing need for the development of new classes of antimycotic drug.
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Affiliation(s)
- Marie von Lilienfeld-Toal
- National Reference Center for Invasive Fungal Infections, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Jena
- Clinic of Internal Medicine II, University Hospital Jena
| | - Johannes Wagener
- National Reference Center for Invasive Fungal Infections, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Jena
- Institute for Hygiene and Microbiology, University of Würzburg, Chair of Medical Microbiology and Mycology, Würzburg
| | - Hermann Einsele
- Department of Internal Medicine II, University Hospital of Würzburg
- InfectControl 2020, Jena/Würzburg
| | - Oliver A. Cornely
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Department I of Internal Medicine, at the University Hospital of Cologne, European Excellence Center for Medical Mycology (ECMM), DGerman Center for Infection Research(DZIF) Partner Site Bonn Köln, Cologne University
| | - Oliver Kurzai
- National Reference Center for Invasive Fungal Infections, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Jena
- Institute for Hygiene and Microbiology, University of Würzburg, Chair of Medical Microbiology and Mycology, Würzburg
- InfectControl 2020, Jena/Würzburg
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197
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Yamamoto T, Umegawa Y, Yamagami M, Suzuki T, Tsuchikawa H, Hanashima S, Matsumori N, Murata M. The Perpendicular Orientation of Amphotericin B Methyl Ester in Hydrated Lipid Bilayers Supports the Barrel-Stave Model. Biochemistry 2019; 58:2282-2291. [PMID: 30973009 DOI: 10.1021/acs.biochem.9b00180] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The clinically important antibiotic amphotericin B (AmB) is a membrane-active natural product that targets membrane sterol. The antimicrobial activity of AmB is generally attributed to its membrane permeabilization, which occurs when a pore is formed across a lipid bilayer. In this study, the molecular orientation of AmB was investigated using solid-state nuclear magnetic resonance (NMR) to better understand the mechanism of antifungal activity. The methyl ester of AmB (AME) labeled with NMR isotopes, d3-AME, and its fluorinated and/or 13C-labeled derivatives were prepared. All of the AmB derivatives showed similar membrane-disrupting activities and ultraviolet spectra in phospholipid liposomes, suggesting that their molecular assemblies in membranes closely mimic those of AmB. Solid-state 2H NMR measurements of d3-AME in a hydrated membrane showed that the mobility of AME molecules depends on concentration and temperature. At a 1:5:45 AME:Erg:dimyristoylphosphatidylcholine ratio, AME became sufficiently mobilized to observe the motional averaging of quadrupole coupling. On the basis of the rotational averaging effect of 19F chemical shift anisotropy, 2H quadrupolar splitting, and 13C-19F dipolar coupling of 14β-F-AMEs, we deduced that the molecular axis of AME is predominantly parallel to the normal of a lipid bilayer. This result supports the barrel-stave model as a molecular assembly of AmB in membranes.
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Affiliation(s)
- Tomoya Yamamoto
- Department of Chemistry, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan.,JST-ERATO Lipid Active Structure Project, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan
| | - Yuichi Umegawa
- Department of Chemistry, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan.,JST-ERATO Lipid Active Structure Project, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan.,Fundamental Science Research Center, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan
| | - Masaki Yamagami
- Department of Chemistry, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan
| | - Taiga Suzuki
- Department of Chemistry, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan
| | - Hiroshi Tsuchikawa
- Department of Chemistry, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan
| | - Shinya Hanashima
- Department of Chemistry, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan
| | - Nobuaki Matsumori
- Department of Chemistry, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan.,Department of Chemistry, Graduate School of Sciences , Kyushu University , Fukuoka 819-0395 , Japan
| | - Michio Murata
- Department of Chemistry, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan.,JST-ERATO Lipid Active Structure Project, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan.,Fundamental Science Research Center, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan
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198
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Thompson GR, Lewis JS, Nix DE, Patterson TF. Current Concepts and Future Directions in the Pharmacology and Treatment of Coccidioidomycosis. Med Mycol 2019; 57:S76-S84. [PMID: 30690601 DOI: 10.1093/mmy/myy029] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 04/19/2018] [Indexed: 12/19/2022] Open
Abstract
Coccidioidomycosis remains a significant clinical problem with substantial morbidity and mortality. The vast majority of infections are asymptomatic and the need for early primary therapy remains controversial. The use of triazole antifungals has improved tolerability of therapy but concerns about acute and long-term toxicities among available agents limit their use. In addition, recent findings of decreased in vitro fluconazole susceptibility to as many as 37% of Coccidioides spp. isolates raises concerns regarding optimal therapy for these infections as fluconazole is commonly used for therapy including central nervous system disease. Thus, new agents from novel antifungal classes are currently in preclinical and clinical development aimed at reducing toxicity and improving outcomes of these serious infections.
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Affiliation(s)
- George R Thompson
- Department of Medical Microbiology and Immunology, University of California, Davis; Davis, California, USA.,Department of Internal Medicine, Division of Infectious Diseases, University of California Davis Medical Center; Sacramento, California, USA
| | - James S Lewis
- Department of Pharmacy, Oregon Health & Science University Hospital and Clinics, Portland, Oregon, USA
| | - David E Nix
- Department of Pharmacy Practice and Science, College of Pharmacy, University of Arizona, Tucson, Arizona, USA
| | - Thomas F Patterson
- Division of Infectious Diseases, UT Health San Antonio, and the South Texas Veterans Health Care System; San Antonio, Texas, USA
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199
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Effect of amphotericin B and voriconazole on the outgrowth of conidia of Aspergillus fumigatus followed by time-lapse microscopy. AMB Express 2019; 9:43. [PMID: 30945013 PMCID: PMC6447639 DOI: 10.1186/s13568-019-0769-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 03/25/2019] [Indexed: 01/09/2023] Open
Abstract
Studies of morphological measurements from the outgrowth of cells to a network of hyphae have been extended from Candida albicans (Nagy et al. in Appl Microbiol Biotechnol 98(11):5185-5194. https://doi.org/10.1007/s00253-014-5696-5 , 2014) to invasive conidiospores of Aspergillus fumigatus upon treatment with antifungal agents. The understanding of mycelial processes is important to optimize industrial processes such as fermentation and contributes to the fight against pathogenic fungi. This brief study combines TLS with digital image analysis. The TLS system was adapted to get information related to the adherence and growth dynamics of filamentous fungi. This approach was used earlier to distinguish among subphases of bacterial and fungal infections of mammal cells by detecting Mycoplasma infection in cell cultures causing serious damages in cell cultures. We describe changes in adherence, germination of spores, and hyphal growth of A. fumigatus, taking place in the absence and presence of amphotericin B (AMB) and voriconazole (VRC). These growth parameters were measured by TLS in CO2 incubator under physiological Photomicrography by TLS and extended for a longer period of time up to several weeks combined with image analysis represents a comfortable and reliable means to characterize the growth dynamism of A. fumigatus. The most important observation of medical importance related to the pathomechanism of VRC was that it did not adhere to conidiospores, i.e. that it did not contribute to the attachment of spores to the growth surface, and did not prevent germination but delayed hypha protrusion and elongation. In contrast AMB adhered to conidia, inhibited germination, hypha elongation and branching. It was concluded that AMB was efficient against the therapy of growth but not against the prevention of fungal infection.
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200
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Borcik CG, Versteeg DB, Wylie BJ. An Inward-Rectifier Potassium Channel Coordinates the Properties of Biologically Derived Membranes. Biophys J 2019; 116:1701-1718. [PMID: 31010661 DOI: 10.1016/j.bpj.2019.03.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 03/20/2019] [Accepted: 03/25/2019] [Indexed: 12/13/2022] Open
Abstract
KirBac1.1 is a prokaryotic inward-rectifier K+ channel from Burkholderia pseudomallei. It shares the common inward-rectifier K+ channel fold with eukaryotic channels, including conserved lipid-binding pockets. Here, we show that KirBac1.1 changes the phase properties and dynamics of the surrounding bilayer. KirBac1.1 was reconstituted into vesicles composed of 13C-enriched biological lipids. Two-dimensional liquid-state and solid-state NMR experiments were used to assign lipid 1H and 13C chemical shifts as a function of lipid identity and conformational degrees of freedom. A solid-state NMR temperature series reveals that KirBac1.1 lowers the primary thermotropic phase transition of Escherichia coli lipid membranes while introducing both fluidity and internal lipid order into the fluid phases. In B. thailandensis liposomes, the bacteriohopanetetrol hopanoid, and potentially ornithine lipids, introduce a similar primary lipid-phase transition and liquid-ordered properties. Adding KirBac1.1 to B. thailandensis lipids increases B. thailandensis lipid fluidity while preserving internal lipid order. This synergistic effect of KirBac1.1 in bacteriohopanetetrol-rich membranes has implications for bilayer dynamic structure. If membrane proteins can anneal lipid translational degrees of freedom while preserving internal order, it could offer an explanation to the nature of liquid-ordered protein-lipid organization in vivo.
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Affiliation(s)
- Collin G Borcik
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas
| | - Derek B Versteeg
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas
| | - Benjamin J Wylie
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas.
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