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Xie W, Dhinojwala A, Gianneschi NC, Shawkey MD. Interactions of Melanin with Electromagnetic Radiation: From Fundamentals to Applications. Chem Rev 2024; 124:7165-7213. [PMID: 38758918 DOI: 10.1021/acs.chemrev.3c00858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/19/2024]
Abstract
Melanin, especially integumentary melanin, interacts in numerous ways with electromagnetic radiation, leading to a set of critical functions, including radiation protection, UV-protection, pigmentary and structural color productions, and thermoregulation. By harnessing these functions, melanin and melanin-like materials can be widely applied to diverse applications with extraordinary performance. Here we provide a unified overview of the melanin family (all melanin and melanin-like materials) and their interactions with the complete electromagnetic radiation spectrum (X-ray, Gamma-ray, UV, visible, near-infrared), which until now has been absent from the literature and is needed to establish a solid fundamental base to facilitate their future investigation and development. We begin by discussing the chemistries and morphologies of both natural and artificial melanin, then the fundamentals of melanin-radiation interactions, and finally the exciting new developments in high-performance melanin-based functional materials that exploit these interactions. This Review provides both a comprehensive overview and a discussion of future perspectives for each subfield of melanin that will help direct the future development of melanin from both fundamental and applied perspectives.
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Affiliation(s)
- Wanjie Xie
- Department of Biology, Evolution and Optics of Nanostructure Group, University of Ghent, Gent 9000, Belgium
| | - Ali Dhinojwala
- School of Polymer Science and Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Nathan C Gianneschi
- Department of Chemistry, Department of Materials Science and Engineering, Department of Biomedical Engineering, Simpson-Querrey Institute, Chemistry of Life Processes Institute, Lurie Cancer Center, and International Institute of Nanotechnology, Northwestern University, Evanston, Illinois 60208, United States
| | - Matthew D Shawkey
- Department of Biology, Evolution and Optics of Nanostructure Group, University of Ghent, Gent 9000, Belgium
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Shree A, Pal S, Verma PK. Structural diversification of fungal cell wall in response to the stress signaling and remodeling during fungal pathogenesis. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2024; 30:733-747. [PMID: 38846457 PMCID: PMC11150350 DOI: 10.1007/s12298-024-01453-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 04/18/2024] [Accepted: 04/20/2024] [Indexed: 06/09/2024]
Abstract
Fungi are one of the most diverse organisms found in our surroundings. The heterotrophic lifestyle of fungi and the ever-changing external environmental factors pose numerous challenges for their survival. Despite all adversities, fungi continuously develop new survival strategies to secure nutrition and space from their host. During host-pathogen interaction, filamentous phytopathogens in particular, effectively infect their hosts by maintaining polarised growth at the tips of hyphae. The fungal cell wall, being the prime component of host contact, plays a crucial role in fortifying the intracellular environment against the harsh external environment. Structurally, the fungal cell wall is a highly dynamic yet rigid component, responsible for maintaining cellular morphology. Filamentous pathogens actively maintain their dynamic cell wall to compensate rapid growth on the host. Additionally, they secrete effectors to dampen the sophisticated mechanisms of plant defense and initiate various downstream signaling cascades to repair the damage inflicted by the host. Thus, the fungal cell wall serves as a key modulator of fungal pathogenicity. The fungal cell wall with their associated signaling mechanisms emerge as intriguing targets for host immunity. This review comprehensively examines and summarizes the multifaceted findings of various research groups regarding the dynamics of the cell wall in filamentous fungal pathogens during host invasion.
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Affiliation(s)
- Ankita Shree
- Plant Immunity Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
| | - Surabhi Pal
- Plant Immunity Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
| | - Praveen Kumar Verma
- Plant Immunity Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
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Bikmurzin R, Maršalka A, Kalėdienė L. Solid-State 13C Nuclear Magnetic Resonance Study of Soluble and Insoluble β-Glucans Extracted from Candida lusitaniae. Molecules 2023; 28:8066. [PMID: 38138557 PMCID: PMC10745363 DOI: 10.3390/molecules28248066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
β-glucans are widely known for their biological activities. However, the choice of extraction method can significantly influence their structural characteristics, thereby potentially impacting their biological functions. In this paper, three fractions of β-glucans were obtained from Candida lusitaniae yeast via alkali and hot-water extraction methods and were analyzed using solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Solid-state NMR spectroscopy was used as a nondestructive technique that preserves the structure of the analyzed molecules. The results suggest that differences in the β-glucan structure are affected by the choice of extraction method. The main difference occurred in the 82-92 ppm region with signal presence suggesting that β-glucans have a linear structure when hot-water-extracted, which is absent in alkali-extracted fractions resulting in the acquisition of β-glucans with an ordered, possibly helical structure. A hot-water extracted water-insoluble (HWN) fraction consists of linear β-1,3-glucans with other signals indicating the presence of β-1,6-linked side chains, chitin and small amounts of α-glucan impurities. For those that are alkali-extracted, alkali-insoluble (AN) and water-soluble (AWS) fractions are structurally similar and consist of an ordered β-1,3-glucan structure with β-1,6-linked side chains and a significant amount of α-glucan and chitin in both fractions.
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Affiliation(s)
- Ruslan Bikmurzin
- Department of Microbiology and Biotechnology, Institute of Biosciences, Life Sciences Center, Vilnius University, Saulėtekio Ave. 7, LT-10257 Vilnius, Lithuania
- Department of Medical Technology and Dietetics, Faculty of Health Care, Vilniaus Kolegija/Higher Education Institution, Didlaukio Str. 45, LT-08303 Vilnius, Lithuania
| | - Arūnas Maršalka
- Institute of Chemical Physics, Faculty of Physics, Vilnius University, Saulėtekio Ave. 3, LT-10257 Vilnius, Lithuania;
| | - Lilija Kalėdienė
- Nature Research Centre, Akademijos Str. 2, LT-08412 Vilnius, Lithuania
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Duan L, Wang L, Chen W, He Z, Zhou E, Zhu Y. Deficiency of ChPks and ChThr1 Inhibited DHN-Melanin Biosynthesis, Disrupted Cell Wall Integrity and Attenuated Pathogenicity in Colletotrichum higginsianum. Int J Mol Sci 2023; 24:15890. [PMID: 37958874 PMCID: PMC10650501 DOI: 10.3390/ijms242115890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 10/24/2023] [Accepted: 10/31/2023] [Indexed: 11/15/2023] Open
Abstract
Colletotrichum higginsianum is a major pathogen causing anthracnose in Chinese flowering cabbage (Brassica parachinensis), posing a significant threat to the Chinese flowering cabbage industry. The conidia of C. higginsianum germinate and form melanized infection structures called appressoria, which enable penetration of the host plant's epidermal cells. However, the molecular mechanism underlying melanin biosynthesis in C. higginsianum remains poorly understood. In this study, we identified two enzymes related to DHN-melanin biosynthesis in C. higginsianum: ChPks and ChThr1. Our results demonstrate that the expression levels of genes ChPKS and ChTHR1 were significantly up-regulated during hyphal and appressorial melanization processes. Furthermore, knockout of the gene ChPKS resulted in a blocked DHN-melanin biosynthetic pathway in hyphae and appressoria, leading to increased sensitivity of the ChpksΔ mutant to cell-wall-interfering agents as well as decreased turgor pressure and pathogenicity. It should be noted that although the Chthr1Δ mutant still exhibited melanin accumulation in colonies and appressoria, its sensitivity to cell-wall-interfering agents and turgor pressure decreased compared to wild-type strains; however, complete loss of pathogenicity was not observed. In conclusion, our results indicate that DHN-melanin plays an essential role in both pathogenicity and cell wall integrity in C. higginsianum. Specifically, ChPks is crucial for DHN-melanin biosynthesis while deficiency of ChThr1 does not completely blocked melanin production.
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Affiliation(s)
| | | | | | | | - Erxun Zhou
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China; (L.D.); (L.W.); (W.C.); (Z.H.)
| | - Yiming Zhu
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China; (L.D.); (L.W.); (W.C.); (Z.H.)
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Li H, Sheng RC, Zhang CN, Wang LC, Li M, Wang YH, Qiao YH, Klosterman SJ, Chen JY, Kong ZQ, Subbarao KV, Chen FM, Zhang DD. Two zinc finger proteins, VdZFP1 and VdZFP2, interact with VdCmr1 to promote melanized microsclerotia development and stress tolerance in Verticillium dahliae. BMC Biol 2023; 21:237. [PMID: 37904147 PMCID: PMC10617112 DOI: 10.1186/s12915-023-01697-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 09/08/2023] [Indexed: 11/01/2023] Open
Abstract
BACKGROUND Melanin plays important roles in morphological development, survival, host-pathogen interactions and in the virulence of phytopathogenic fungi. In Verticillum dahliae, increases in melanin are recognized as markers of maturation of microsclerotia which ensures the long-term survival and stress tolerance, while decreases in melanin are correlated with increased hyphal growth in the host. The conserved upstream components of the VdCmr1-regulated pathway controlling melanin production in V. dahliae have been extensively identified, but the direct activators of this pathway are still unclear. RESULTS We identified two genes encoding conserved C2H2-type zinc finger proteins VdZFP1 and VdZFP2 adjacent to VdPKS9, a gene encoding a negative regulator of both melanin biosynthesis and microsclerotia formation in V. dahliae. Both VdZFP1 and VdZFP2 were induced during microsclerotia development and were involved in melanin deposition. Their localization changed from cytoplasmic to nuclear in response to osmotic pressure. VdZFP1 and VdZFP2 act as modulators of microsclerotia melanization in V. dahliae, as confirmed by melanin biosynthesis inhibition and supplementation with the melanin pathway intermediate scytalone in albino strains. The results indicate that VdZFP1 and VdZFP2 participate in melanin biosynthesis by positively regulating VdCmr1. Based on the results obtained with yeast one- and two-hybrid (Y1H and Y2H) and bimolecular fluorescence complementation (BiFC) systems, we determined the melanin biosynthesis relies on the direct interactions among VdZFP1, VdZFP2 and VdCmr1, and these interactions occur on the cell walls of microsclerotia. Additionally, VdZFP1 and/or VdZFP2 mutants displayed increased sensitivity to stress factors rather than alterations in pathogenicity, reflecting the importance of melanin in stress tolerance of V. dahliae. CONCLUSIONS Our results revealed that VdZFP1 and VdZFP2 positively regulate VdCmr1 to promote melanin deposition during microsclerotia development, providing novel insight into the regulation of melanin biosynthesis in V. dahliae.
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Affiliation(s)
- Huan Li
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Ruo-Cheng Sheng
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Chen-Ning Zhang
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Li-Chao Wang
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Min Li
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Ya-Hong Wang
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Yu-Hang Qiao
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Steven J Klosterman
- United States Department of Agriculture, Agricultural Research Service, Salinas, CA, USA
| | - Jie-Yin Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
- Western Agricultural Research Center, Chinese Academy of Agricultural Sciences, Changji, 831100, China
| | - Zhi-Qiang Kong
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
- Western Agricultural Research Center, Chinese Academy of Agricultural Sciences, Changji, 831100, China
| | - Krishna V Subbarao
- Department of Plant Pathology, University of California, Davis, c/o United States Agricultural Research Station,, Salinas, CA, USA.
| | - Feng-Mao Chen
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China.
| | - Dan-Dan Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
- Western Agricultural Research Center, Chinese Academy of Agricultural Sciences, Changji, 831100, China.
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Kim JS, Bahn YS. Protein Kinase A Controls the Melanization of Candida auris through the Alteration of Cell Wall Components. Antioxidants (Basel) 2023; 12:1702. [PMID: 37760005 PMCID: PMC10525270 DOI: 10.3390/antiox12091702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/23/2023] [Accepted: 08/28/2023] [Indexed: 09/29/2023] Open
Abstract
Candida auris, a multidrug-resistant fungal pathogen, significantly threatens global public health. Recent studies have identified melanin production, a key virulence factor in many pathogenic fungi that protects against external threats like reactive oxygen species, in C. auris. However, the melanin regulation mechanism remains elusive. This study explores the role of the Ras/cAMP/PKA signaling pathway in C. auris melanization. It reveals that the catalytic subunits Tpk1 and Tpk2 of protein kinase A (PKA) are essential, whereas Ras1, Gpr1, Gpa2, and Cyr1 are not. Under melanin-promoting conditions, the tpk1Δ tpk2Δ strain formed melanin granules in the supernatant akin to the wild-type strain but failed to adhere them properly to the cell wall. This discrepancy is likely due to a decreased expression of chitin-synthesis-related genes. Our findings also show that Tpk1 primarily drives melanization, with Tpk2 having a lesser impact. To corroborate this, we found that C. auris must deploy Tpk1-dependent melanin deposition as a defensive mechanism against antioxidant exposure. Moreover, we confirmed that deletion mutants of multicopper oxidase and ferroxidase genes, previously assumed to influence C. auris melanization, do not directly contribute to the process. Overall, this study sheds light on the role of PKA in C. auris melanization and enhances our understanding of the pathogenicity mechanisms of this emerging fungal pathogen.
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Affiliation(s)
| | - Yong-Sun Bahn
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Republic of Korea;
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Daminova AG, Rassabina AE, Khabibrakhmanova VR, Beckett RP, Minibayeva FV. Topography of UV-Melanized Thalli of Lobaria pulmonaria (L.) Hoffm. PLANTS (BASEL, SWITZERLAND) 2023; 12:2627. [PMID: 37514242 PMCID: PMC10383456 DOI: 10.3390/plants12142627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/04/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023]
Abstract
Lichens are unique extremophilic organisms due to their phenomenal resistance to adverse environmental factors, including ultraviolet (UV) irradiation. Melanization plays a special role in the protection of lichens from UV-B stress. In the present study, we analyzed the binding of melanins with the components of cell walls of the mycobiont of the upper cortex in the melanized lichen thalli Lobaria pulmonaria. Using scanning electron and atomic force microscopy, the morphological and nanomechanical characteristics of the melanized layer of mycobiont cells were visualized. Melanization of lichen thalli led to the smoothing of the surface relief and thickening of mycobiont cell walls, as well as the reduction in adhesion properties of the lichen thallus. Treatment of thalli with hydrolytic enzymes, especially chitinase and lichenase, enhanced the yield of melanin from melanized thalli and promoted the release of carbohydrates, while treatment with pectinase increased the release of carbohydrates and phenols. Our results suggest that melanin can firmly bind with hyphal cell wall carbohydrates, particularly chitin and 1,4-β-glucans, strengthening the melanized upper cortex of lichen thalli, and thereby it can contribute to lichen survival under UV stress.
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Affiliation(s)
- Amina G Daminova
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, 2/31, Lobachevsky Str., Kazan 420111, Russia
| | - Anna E Rassabina
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, 2/31, Lobachevsky Str., Kazan 420111, Russia
| | - Venera R Khabibrakhmanova
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, 2/31, Lobachevsky Str., Kazan 420111, Russia
| | - Richard P Beckett
- School of Life Sciences, University of KwaZulu-Natal, PBag X01, Scottsville 3209, South Africa
| | - Farida V Minibayeva
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, 2/31, Lobachevsky Str., Kazan 420111, Russia
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Smith DFQ, Mudrak NJ, Zamith-Miranda D, Honorato L, Nimrichter L, Chrissian C, Smith B, Gerfen G, Stark RE, Nosanchuk JD, Casadevall A. Melanization of Candida auris Is Associated with Alteration of Extracellular pH. J Fungi (Basel) 2022; 8:1068. [PMID: 36294632 PMCID: PMC9604884 DOI: 10.3390/jof8101068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 10/05/2022] [Accepted: 10/07/2022] [Indexed: 11/29/2022] Open
Abstract
Candida auris is a recently emerged global fungal pathogen, which causes life-threatening infections, often in healthcare settings. C. auris infections are worrisome because the fungus is often resistant to multiple antifungal drug classes. Furthermore, C. auris forms durable and difficult to remove biofilms. Due to the relatively recent, resilient, and resistant nature of C. auris, we investigated whether it produces the common fungal virulence factor melanin. Melanin is a black-brown pigment typically produced following enzymatic oxidation of aromatic precursors, which promotes fungal virulence through oxidative stress resistance, mammalian immune response evasion, and antifungal peptide and pharmaceutical inactivation. We found that certain strains of C. auris oxidized L-DOPA and catecholamines into melanin. Melanization occurred extracellularly in a process mediated by alkalinization of the extracellular environment, resulting in granule-like structures that adhere to the fungus' external surface. C. auris had relatively high cell surface hydrophobicity, but there was no correlation between hydrophobicity and melanization. Melanin protected the fungus from oxidative damage, but we did not observe a protective role during infection of macrophages or Galleria mellonella larvae. In summary, C. auris alkalinizes the extracellular medium, which promotes the non-enzymatic oxidation of L-DOPA to melanin that attaches to its surface, thus illustrating a novel mechanism for fungal melanization.
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Affiliation(s)
- Daniel F. Q. Smith
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Nathan J. Mudrak
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
- Krieger School of Arts & Science, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Daniel Zamith-Miranda
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
| | - Leandro Honorato
- Laboratório de Glicobiologia de Eucariotos, Departamento de Microbiologia Geral, Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, Brazil
| | - Leonardo Nimrichter
- Laboratório de Glicobiologia de Eucariotos, Departamento de Microbiologia Geral, Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, Brazil
| | - Christine Chrissian
- Department of Chemistry and Biochemistry, City College of New York and CUNY Institute for Macromolecular Assemblies, The City University of New York, New York, NY 10031, USA
| | - Barbara Smith
- Institute for Basic Biomedical Sciences Microscope Facility, The Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Gary Gerfen
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
| | - Ruth E. Stark
- Department of Chemistry and Biochemistry, City College of New York and CUNY Institute for Macromolecular Assemblies, The City University of New York, New York, NY 10031, USA
| | - Joshua D. Nosanchuk
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
| | - Arturo Casadevall
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
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Pereira JAL, de Moraes LS, de Sena CBC, do Nascimento JLM, Rodrigues APD, da Silva SHM, Silva EO. Inhibition of Melanization by Kojic Acid Promotes Cell Wall Disruption of the Human Pathogenic Fungus Fonsecaea sp. Pathogens 2022; 11:pathogens11080925. [PMID: 36015045 PMCID: PMC9414132 DOI: 10.3390/pathogens11080925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/05/2022] [Accepted: 08/11/2022] [Indexed: 11/16/2022] Open
Abstract
Chromoblastomycosis (CBM) is a chronic human subcutaneous mycosis caused by various aetiologic agents. CBM does not have an established treatment but may be managed using antifungal agents, surgical removal of the lesions, or cryotherapy. Kojic acid (KA), a known tyrosinase inhibitor with a variety of biological actions, including fungistatic action against the fungus Cryptococcus neoformans, mediated by inhibiting melanin production, seems to be an alternative to improve the treatment of CBM. The aim of the present study was to analyze the action of KA against the pathogenic fungus Fonsecaea sp., an aetiological agent of CBM. The fungal culture was incubated with KA, and the amount of melanin was assessed, followed by cytochemical detection. Subsequently, the samples were analyzed by light microscopy, transmission and scanning electron microscopy. Culture analysis revealed that 100 g/mL KA significantly decreased the melanization of the fungus and the exocytosis of melanin into the culture supernatant. Additionally, KA induced less growth of biofilm formation and intense disruption of the cell wall, and decreased the number of melanin-containing vesicles in the culture supernatant. Finally, KA inhibited fungal filamentation in culture and the subsequent phagocytosis process. Thus, KA may be a promising substance to help in the treatment of CBM.
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Affiliation(s)
- Jorge Augusto Leão Pereira
- Laboratory of Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil
| | - Lienne Silveira de Moraes
- Laboratory of Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil
- National Institute of Science and Technology in Structural Biology and Bioimaging, Rio de Janeiro 21040-900, RJ, Brazil
- Pharmaceutical Sciences Post Graduation Program, Health and Biological Sciences Department, Federal University of Amapa (UNIFAP), Macapá 68903-329, AP, Brazil
| | - Chubert Bernardo Castro de Sena
- Laboratory of Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil
- National Institute of Science and Technology in Neuroimmunomodulation (INCT—NIM), Rio de Janeiro 21040-900, RJ, Brazil
| | - José Luiz Martins do Nascimento
- Pharmaceutical Sciences Post Graduation Program, Health and Biological Sciences Department, Federal University of Amapa (UNIFAP), Macapá 68903-329, AP, Brazil
- National Institute of Science and Technology in Neuroimmunomodulation (INCT—NIM), Rio de Janeiro 21040-900, RJ, Brazil
- Laboratory of Molecular and Cellular Neurochemistry, Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil
| | - Ana Paula D. Rodrigues
- National Institute of Science and Technology in Structural Biology and Bioimaging, Rio de Janeiro 21040-900, RJ, Brazil
- Laboratory of Electron Microscopy, Evandro Chagas Institute, Ministry of Health, Belém 66093-020, PA, Brazil
| | - Silvia Helena Marques da Silva
- Laboratory of Superficial and Systemic Mycoses, Evandro Chagas Institute, Department of Mycology and Bacteriology, Ministry of Health, Ananindeua 67030-000, PA, Brazil
| | - Edilene O. Silva
- Laboratory of Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil
- National Institute of Science and Technology in Structural Biology and Bioimaging, Rio de Janeiro 21040-900, RJ, Brazil
- Correspondence: ; Tel.: +055-9132-0175-46
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10
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Li Z, Heng H, Qin Q, Chen L, Wang Y, Zhou Z. Physicochemical properties, molecular structure, antioxidant activity, and biological function of extracellular melanin from Ascosphaera apis. J Zhejiang Univ Sci B 2022; 23:365-381. [PMID: 35557038 DOI: 10.1631/jzus.b2100718] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Ascosphaera apis spores containing a dark-colored pigment infect honeybee larvae, resulting in a large-scale collapse of the bee colony due to chalkbrood disease. However, little is known about the pigment or whether it plays a role in bee infection caused by A. apis. In this study, the pigment was isolated by alkali extraction, acid hydrolysis, and repeated precipitation. Ultraviolet (UV) analysis revealed that the pigment had a color value of 273, a maximum absorption peak at 195 nm, and a high alkaline solubility (7.67%) and acid precipitability. Further chemical structure analysis of the pigment, including elemental composition, Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, mass spectrometry, and nuclear magnetic resonance (NMR), proved that it was a eumelanin with a typical indole structure. The molecular formula of melanin is C10H6O4N2, and its molecular weight is 409 Da. Melanin has hydroxyl, carboxyl, amino, and phenolic groups that can potentially chelate to metal ions. Antioxidant function analyses showed that A. apis melanin had a high scavenging activity against superoxide, hydroxyl, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals, and a high reducing ability to Fe3+. Indirect immunofluorescence assay (IFA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses showed that A. apis melanin was located on the spore wall. The spore wall localization, antioxidant activity, and metal ion chelating properties of fungal melanin have been suggested to contribute to spore pathogenicity. However, further infection experiments showed that melanin-deficient spores did not reduce the mortality of bee larvae, indicating that melanin does not increase the virulence of A. apis spores. This study is the first report on melanin produced by A. apis, providing an important background reference for further study on its role in A. apis.
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Affiliation(s)
- Zhi Li
- College of Life Sciences, Chongqing Normal University, Chongqing 401331, China. .,Chongqing Key Laboratory of Vector Insects, Chongqing 401331, China. .,Chongqing Key Laboratory of Animal Biology, Chongqing 401331, China.
| | - Hui Heng
- College of Life Sciences, Chongqing Normal University, Chongqing 401331, China
| | - Qiqian Qin
- College of Life Sciences, Chongqing Normal University, Chongqing 401331, China
| | - Lanchun Chen
- College of Life Sciences, Chongqing Normal University, Chongqing 401331, China
| | - Yuedi Wang
- College of Life Sciences, Chongqing Normal University, Chongqing 401331, China
| | - Zeyang Zhou
- College of Life Sciences, Chongqing Normal University, Chongqing 401331, China.,Chongqing Key Laboratory of Microsporidia Infection and Control, Chongqing 400715, China.,The State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
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11
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Milne G, Walker LA. High-Pressure Freezing and Transmission Electron Microscopy to Visualize the Ultrastructure of the C. auris Cell Wall. Methods Mol Biol 2022; 2517:189-201. [PMID: 35674955 DOI: 10.1007/978-1-0716-2417-3_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Transmission electron microscopy (TEM) is the main technique used to study the ultrastructure of biological samples. Chemical fixation was considered the main method for preserving samples for TEM; however, it is a relatively slow method of fixation and can result in morphological alterations. Cryofixation using high-pressure freezing (HPF) overcomes the limitations of chemical fixation by preserving samples instantly. Here, we describe our HPF methods optimized for visualizing Candida auris at the ultrastructural level.
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Affiliation(s)
- Gillian Milne
- Institute of Medical Sciences (IMS), School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, UK
| | - Louise A Walker
- Institute of Medical Sciences (IMS), School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, UK.
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12
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Solid-state NMR analysis of unlabeled fungal cell walls from Aspergillus and Candida species. J Struct Biol X 2022; 6:100070. [PMID: 35899175 PMCID: PMC9310124 DOI: 10.1016/j.yjsbx.2022.100070] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 07/10/2022] [Accepted: 07/15/2022] [Indexed: 11/21/2022] Open
Abstract
An NMR investigation strategy with atomic resolution for unlabeled fungal cell walls. Conserved carbohydrate core revealed in conidia and mycelia of Aspergillus fumigatus. Confirmation of the structural function of α-glucans in A. fumigatus. Carbohydrate fingerprints preserved in liquid and solid cultures of Candida albicans.
Fungal infections cause high mortality in immunocompromised individuals, which has emerged as a significant threat to human health. The efforts devoted to the development of antifungal agents targeting the cell wall polysaccharides have been hindered by our incomplete picture of the assembly and remodeling of fungal cell walls. High-resolution solid-state nuclear magnetic resonance (ss NMR) studies have substantially revised our understanding of the polymorphic structure of polysaccharides and the nanoscale organization of cell walls in Aspergillus fumigatus and multiple other fungi. However, this approach requires 13C/15N-enrichment of the sample being studied, severely restricting its application. Here we employ the dynamic nuclear polarization (DNP) technique to compare the unlabeled cell wall materials of A. fumigatus and C. albicans prepared using both liquid and solid media. For each fungus, we have identified a highly conserved carbohydrate core for the cell walls of conidia and mycelia, and from liquid and solid cultures. Using samples prepared in different media, the recently identified function of α-glucan, which packs with chitin to form the mechanical centers, has been confirmed through conventional ss NMR measurements of polymer dynamics. These timely efforts not only validate the structural principles recently discovered for A. fumigatus cell walls in different morphological stages, but also open up the possibility of extending the current investigation to other fungal materials and cellular systems that are challenging to label.
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13
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Huang H, Zhang X, Zhang Y, Yi G, Xie J, Viljoen A, Wang W, Mostert D, Fu G, Peng C, Xiang D, Li C, Liu S. FocECM33, a GPI-anchored protein, regulates vegetative growth and virulence in Fusarium oxysporum f. sp. cubense tropical race 4. Fungal Biol 2022; 126:213-223. [DOI: 10.1016/j.funbio.2021.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 09/21/2021] [Accepted: 12/24/2021] [Indexed: 11/04/2022]
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14
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Dai B, Xu Y, Wu H, Chen J. Rim101-upregulated Fets contribute to dark pigment formation in gray cells of Candida albicans. Acta Biochim Biophys Sin (Shanghai) 2021; 53:1723-1730. [PMID: 34599586 DOI: 10.1093/abbs/gmab142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Indexed: 11/15/2022] Open
Abstract
Candida albicans has long been known to switch between white and opaque phases; however, a third cell type, referred to as the 'gray' phenotype, was recently characterized. The three phenotypes have different colonial morphologies, with white cells forming white-colored colonies and opaque and gray cells forming dark-colored colonies. We previously showed that Wor1-upregulated ferroxidases (Fets) function as pigment multicopper oxidases that regulate the production of dark-pigmented melanin in opaque cells. In this study, we demonstrated that Fets also contributed to dark pigment formation in gray colonies but in a Wor1-independent manner. Deletion of both WOR1 and EFG1 locked cells in the gray phenotype in some rich media. However, the efg1/efg1 wor1/wor1 mutant could switch between white and gray in minimal media depending on the ambient pH. Specifically, mutant cells exhibited the white phenotype at pH 4.5 but switched to gray at pH 7.5. Consistent with phenotype switching, Fets expressions and melanin production were also regulated by ambient pH. Ectopic expression of the Rim101-405 allele in the mutant enabled the pH restriction to be bypassed and promoted gray cell formation in acidic media. Our data suggest that Rim101-upregulated Fets contribute to dark pigment formation in the gray cells.
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Affiliation(s)
- Baodi Dai
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
| | - Yinxing Xu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
| | - Hongyu Wu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
| | - Jiangye Chen
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
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15
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Choi KY. Bioprocess of Microbial Melanin Production and Isolation. Front Bioeng Biotechnol 2021; 9:765110. [PMID: 34869277 PMCID: PMC8637283 DOI: 10.3389/fbioe.2021.765110] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 10/28/2021] [Indexed: 12/17/2022] Open
Abstract
Melanin is one of the most abundant pigments found in the biosphere. Owing to its high biocompatibility and diverse biological activities, it has been widely applied as a functional biomaterial in the cosmetic, pharmaceutical, biopolymer, and environmental fields. In this study, the production of melanin was comprehensively reviewed concerning bioconversion and isolation processes. First, several melanogenic microbes, including fungi and bacteria, were summarized. Melanin production was classified by host and melanin type and was analyzed by titers in g/L in addition to reaction conditions, including pH and temperature. The production was further interpreted using a space-time yields chart, which showed two distinct classifications in productivity, and reaction conditions were analyzed using a pH-temperature-titer chart. Next, the extraction process was summarized by crude and pure melanin preparation procedures, and the extraction yields were highlighted. Finally, the recent applications of melanin were briefly summarized, and prospects for further application and development in industrial applications were suggested.
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Affiliation(s)
- Kwon-Young Choi
- Department of Environmental Engineering, College of Engineering, Ajou University, Suwon, South Korea.,Department of Environmental and Safety Engineering, College of Engineering, Ajou University, Suwon, South Korea
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16
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Figueiredo ABC, Fonseca FL, Kuczera D, Conte FDP, Arissawa M, Rodrigues ML. Monoclonal Antibodies against Cell Wall Chitooligomers as Accessory Tools for the Control of Cryptococcosis. Antimicrob Agents Chemother 2021; 65:e0118121. [PMID: 34570650 PMCID: PMC8597760 DOI: 10.1128/aac.01181-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 09/21/2021] [Indexed: 11/20/2022] Open
Abstract
Therapeutic strategies against systemic mycoses can involve antifungal resistance and significant toxicity. Thus, novel therapeutic approaches to fight fungal infections are urgent. Monoclonal antibodies (MAbs) are promising tools to fight systemic mycoses. In this study, MAbs of the IgM isotype were developed against chitin oligomers. Chitooligomers derive from chitin, an essential component of the fungal cell wall and a promising therapeutic target, as it is not synthesized by humans or animals. Surface plasmon resonance (SPR) assays and cell-binding tests showed that the MAbs recognizing chitooligomers have high affinity and specificity for the chitin derivatives. In vitro tests showed that the chitooligomer MAbs increased the fungicidal capacity of amphotericin B against Cryptococcus neoformans. The chitooligomer-binding MAbs interfered with two essential properties related to cryptococcal pathogenesis: biofilm formation and melanin production. In a murine model of C. neoformans infection, the combined administration of the chitooligomer-binding MAb and subinhibitory doses of amphotericin B promoted disease control. The data obtained in this study support the hypothesis that chitooligomer antibodies have great potential as accessory tools in the control of cryptococcosis.
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Affiliation(s)
| | - Fernanda L. Fonseca
- Centro de Desenvolvimento Tecnológico em Saúde, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Diogo Kuczera
- Instituto Carlos Chagas, Fundação Oswaldo Cruz, Curitiba, Brazil
| | - Fernando de Paiva Conte
- Projeto Implantação Planta Piloto, Bio-Manguinhos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Marcia Arissawa
- Vice Diretoria de Desenvolvimento Técnologico, Bio-Manguinhos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Marcio L. Rodrigues
- Instituto Carlos Chagas, Fundação Oswaldo Cruz, Curitiba, Brazil
- Instituto de Microbiologia Paulo de Góes da Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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17
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Fernandes C, Mota M, Barros L, Dias MI, Ferreira ICFR, Piedade AP, Casadevall A, Gonçalves T. Pyomelanin Synthesis in Alternaria alternata Inhibits DHN-Melanin Synthesis and Decreases Cell Wall Chitin Content and Thickness. Front Microbiol 2021; 12:691433. [PMID: 34512569 PMCID: PMC8430343 DOI: 10.3389/fmicb.2021.691433] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 07/26/2021] [Indexed: 12/15/2022] Open
Abstract
The genus Alternaria includes several of fungi that are darkly pigmented by DHN-melanin. These are pathogenic to plants but are also associated with human respiratory allergic diseases and with serious infections in immunocompromised individuals. The present work focuses on the alterations of the composition and structure of the hyphal cell wall of Alternaria alternata occuring under the catabolism of L-tyrosine and L-phenylalanine when cultured in minimal salt medium (MM). Under these growing conditions, we observed the released of a brown pigment into the culture medium. FTIR analysis demonstrates that the produced pigment is chemically identical to the pigment released when the fungus is grown in MM with homogentisate acid (HGA), the intermediate of pyomelanin, confirming that this pigment is pyomelanin. In contrast to other fungi that also synthesize pyomelanin under tyrosine metabolism, A. alternata inhibits DHN-melanin cell wall accumulation when pyomelanin is produced, and this is associated with reduced chitin cell wall content. When A. alternata is grown in MM containing L-phenylalanine, a L-tyrosine percursor, pyomelanin is synthesized but only at trace concentrations and A. alternata mycelia display an albino-like phenotype since DHN-melanin accumulation is inhibited. CmrA, the transcription regulator for the genes coding for the DHN-melanin pathway, is involved in the down-regulation of DHN-melanin synthesis when pyomelanin is being synthetized, since the CMRA gene and genes of the enzymes involved in DHN-melanin synthesis pathway showed a decreased expression. Other amino acids do not trigger pyomelanin synthesis and DHN-melanin accumulation in the cell wall is not affected. Transmission and scanning electron microscopy show that the cell wall structure and surface decorations are altered in L-tyrosine- and L-phenylalanine-grown fungi, depending on the pigment produced. In summary, growth in presence of L-tyrosine and L-phenylalanine leads to pigmentation and cell wall changes, which could be relevant to infection conditions where these amino acids are expected to be available.
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Affiliation(s)
- Chantal Fernandes
- CNC—Center for Neuroscience and Cell Biology of Coimbra, Coimbra, Portugal
| | - Marta Mota
- CNC—Center for Neuroscience and Cell Biology of Coimbra, Coimbra, Portugal
- FMUC—Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Lillian Barros
- Mountain Research Center (CIMO), Polytechnic Institute of Bragança, Bragança, Portugal
- Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Polytechnic Institute of Bragança, Bragança, Portugal
| | - Maria Inês Dias
- Mountain Research Center (CIMO), Polytechnic Institute of Bragança, Bragança, Portugal
- Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Polytechnic Institute of Bragança, Bragança, Portugal
| | - Isabel C. F. R. Ferreira
- Mountain Research Center (CIMO), Polytechnic Institute of Bragança, Bragança, Portugal
- Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Polytechnic Institute of Bragança, Bragança, Portugal
| | - Ana P. Piedade
- Centre for Mechanical Engineering, Materials and Processes, Department of Mechanical Engineering, University of Coimbra, Coimbra, Portugal
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - Teresa Gonçalves
- CNC—Center for Neuroscience and Cell Biology of Coimbra, Coimbra, Portugal
- FMUC—Faculty of Medicine, University of Coimbra, Coimbra, Portugal
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18
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Freitas DF, da Rocha IM, Vieira-da-Motta O, de Paula Santos C. The Role of Melanin in the Biology and Ecology of Nematophagous Fungi. J Chem Ecol 2021; 47:597-613. [PMID: 34232439 DOI: 10.1007/s10886-021-01282-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 05/03/2021] [Accepted: 05/13/2021] [Indexed: 11/24/2022]
Abstract
Melanin is a heteropolymer formed by the polymerization of phenolic and indolic compounds. It occurs in organisms across all biological kingdoms and has a range different of functions, thus indicating its important evolutionary role. The presence of melanin offers several protective advantages, including against ultraviolet radiation, traumatic damage, oxidative stress, extreme temperatures, and pressure. For many species of fungi, melanin also participates directly in the process of virulence and pathogenicity. These organisms can synthesize melanin in two main ways: using a substrate of endogenous origin, involving 1,8-dihydroxynaphthalene (DHN); alternatively, in an exogenous manner with the addition of L-3, 4-dihydroxyphenylalanine (L-DOPA or levodopa). As melanin is an amorphous and complex substance, its study requires expensive and inaccessible technologies and analyses are often difficult to perform with conventional biochemical techniques. As such, details about its chemical structure are not yet fully understood, particularly for nematophagous fungi that remain poorly studied. Thus, this review presents an overview of the different types of melanin, with an emphasis on fungi, and discusses the role of melanin in the biology and ecology of nematophagous fungi.
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Affiliation(s)
- Deivid França Freitas
- Laboratory of Cellular and Tissue Biology-LBCT, State University of the North Fluminense Darcy Ribeiro-UENF, Av. Alberto Lamego, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, Cep. 28013‑600, Brazil
| | - Izabelli Martins da Rocha
- Laboratory of Cellular and Tissue Biology-LBCT, State University of the North Fluminense Darcy Ribeiro-UENF, Av. Alberto Lamego, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, Cep. 28013‑600, Brazil
| | - Olney Vieira-da-Motta
- Animal Health Laboratory - Infectious Contagious Diseases Sector, State University of North Fluminense Darcy Ribeiro-UENF, Av. Alberto Lamego, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, Cep. 28013‑600, Brazil
| | - Clóvis de Paula Santos
- Laboratory of Cellular and Tissue Biology-LBCT, State University of the North Fluminense Darcy Ribeiro-UENF, Av. Alberto Lamego, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, Cep. 28013‑600, Brazil.
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19
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Almeida-Paes R, Figueiredo-Carvalho MH, da Silva LB, Gerfen G, S Araújo GRD, Frases S, Zancopé-Oliveira RM, Nosanchuk JD. Candida glabrata produces a melanin-like pigment that protects against stress conditions encountered during parasitism. Future Microbiol 2021; 16:509-520. [PMID: 33960816 DOI: 10.2217/fmb-2020-0228] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: Melanin has been linked to pathogenesis in several fungi. They often produce melanin-like pigments in the presence of L-dihydroxyphenylalanine (L-DOPA), but this is poorly studied in Candida glabrata. Methods & materials: C. glabrata was grown in minimal medium with or without L-DOPA supplementation and submitted to a chemical treatment with denaturant and hot acid. Results: C. glabrata turned black when grown in the presence of L-DOPA, whereas cells grown without L-DOPA supplementation remained white. Biophysical properties demonstrated that the pigment was melanin. Melanized C. glabrata cells were effectively protected from azoles and amphotericin B, incubation at 42°C and macrophage killing. Conclusion: In the presence of L-DOPA, C. glabrata produces melanin, increases antifungal resistance and enhances host survival.
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Affiliation(s)
- Rodrigo Almeida-Paes
- Laboratório de Micologia, Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil.,Departments of Medicine (Division of Infectious Diseases) & Microbiology & Immunology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Maria Hg Figueiredo-Carvalho
- Laboratório de Micologia, Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
| | - Leandro Br da Silva
- Departments of Medicine (Division of Infectious Diseases) & Microbiology & Immunology, Albert Einstein College of Medicine, Bronx, NY, USA.,Instituto de Ciências Biomédicas, Departamento de Microbiologia, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Gary Gerfen
- Department of Biophysics, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Glauber R de S Araújo
- Laboratório de Biofísica de Fungos, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Susana Frases
- Laboratório de Biofísica de Fungos, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Rosely M Zancopé-Oliveira
- Laboratório de Micologia, Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
| | - Joshua D Nosanchuk
- Departments of Medicine (Division of Infectious Diseases) & Microbiology & Immunology, Albert Einstein College of Medicine, Bronx, NY, USA
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20
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Liu S, Youngchim S, Zamith-Miranda D, Nosanchuk JD. Fungal Melanin and the Mammalian Immune System. J Fungi (Basel) 2021; 7:jof7040264. [PMID: 33807336 PMCID: PMC8066723 DOI: 10.3390/jof7040264] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/25/2021] [Accepted: 03/26/2021] [Indexed: 02/06/2023] Open
Abstract
Melanins are ubiquitous complex polymers that are commonly known in humans to cause pigmentation of our skin. Melanins are also present in bacteria, fungi, and helminths. In this review, we will describe the diverse interactions of fungal melanin with the mammalian immune system. We will particularly focus on Cryptococcus neoformans and also discuss other major melanotic pathogenic fungi. Melanin interacts with the immune system through diverse pathways, reducing the effectiveness of phagocytic cells, binding effector molecules and antifungals, and modifying complement and antibody responses.
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Affiliation(s)
- Sichen Liu
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (S.L.); (D.Z.-M.)
| | - Sirida Youngchim
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand;
| | - Daniel Zamith-Miranda
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (S.L.); (D.Z.-M.)
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Joshua D. Nosanchuk
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (S.L.); (D.Z.-M.)
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Correspondence:
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21
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Dai B, Xu Y, Gao N, Chen J. Wor1-regulated ferroxidases contribute to pigment formation in opaque cells of Candida albicans. FEBS Open Bio 2021; 11:598-621. [PMID: 33350590 PMCID: PMC7931227 DOI: 10.1002/2211-5463.13070] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/14/2020] [Accepted: 12/19/2020] [Indexed: 12/25/2022] Open
Abstract
Candida albicans is a harmless commensal resident in the human gut and a prevalent opportunistic pathogen. A key part of its commensalism and pathogenesis is its ability to switch between different morphological forms, including white‐to‐opaque switching. The Wor1 protein was previously identified as a master regulator of white‐to‐opaque switching in mating type locus (MTL) homozygous cells. The mechanisms by which the dark color of the opaque colonies is controlled and the pimpled surface of opaque cells is formed remain unknown. Candida albicans produces melanin pigment in vitro and during infection. However, the molecular mechanism underlying the regulation of melanin production is unclear. In this study, we demonstrated that ferroxidases (Fets) function as pigment multicopper oxidases and regulate the production of dark‐pigmented melanin in opaque cells. The FET genes presented distinct regulation patterns in response to different extracellular stimuli. In YPD (1% yeast extract, 2% peptone and 2% dextrose)‐rich medium, four of the five FET genes were up‐regulated by Wor1, especially at the human body temperature of 37 °C. In minimal medium with low ammonium concentrations, all five FET genes were up‐regulated by Wor1. However, at high ammonium concentrations, some FET genes were down‐regulated by Wor1. Wor1‐up‐regulated Fets contributed to dark pigment formation in opaque colonies, but not to the elongated shape of these opaque cells. Increased melanin externalization was associated with the pimpled surface of the opaque cells. Melanized C. albicans cells were more resistant to fungal clearance. Deletion of the five FET genes completely blocked melanin production in opaque cells and resulted in the generation of white elongated ‘opaque’ cells. In addition, the up‐regulated Fets are important for defense against oxidant attacks. The functional diversity of Fets may reflect the multiple strategies of C. albicans to rapidly adapt to diverse host niches.
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Affiliation(s)
- Baodi Dai
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Yinxing Xu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Ning Gao
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Jiangye Chen
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
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22
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“Feast-Fit-Fist-Feat”: Overview of Free-living Amoeba Interactions with Fungi and Virulence as a Foundation for Success in Battle. CURRENT TROPICAL MEDICINE REPORTS 2021. [DOI: 10.1007/s40475-020-00220-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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23
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García-Carnero LC, Martínez-Álvarez JA, Salazar-García LM, Lozoya-Pérez NE, González-Hernández SE, Tamez-Castrellón AK. Recognition of Fungal Components by the Host Immune System. Curr Protein Pept Sci 2021; 21:245-264. [PMID: 31889486 DOI: 10.2174/1389203721666191231105546] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 08/08/2019] [Accepted: 10/15/2019] [Indexed: 11/22/2022]
Abstract
By being the first point of contact of the fungus with the host, the cell wall plays an important role in the pathogenesis, having many molecules that participate as antigens that are recognized by immune cells, and also that help the fungus to establish infection. The main molecules reported to trigger an immune response are chitin, glucans, oligosaccharides, proteins, melanin, phospholipids, and others, being present in the principal pathogenic fungi with clinical importance worldwide, such as Histoplasma capsulatum, Paracoccidioides brasiliensis, Aspergillus fumigatus, Candida albicans, Cryptococcus neoformans, Blastomyces dermatitidis, and Sporothrix schenckii. Knowledge and understanding of how the immune system recognizes and responds to fungal antigens are relevant for the future research and development of new diagnostic tools and treatments for the control of mycosis caused by these fungi.
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Affiliation(s)
- Laura C García-Carnero
- Department of Biology, Exact and Natural Sciences Division, Universidad de Guanajuato, Guanajuato, Mexico
| | - José A Martínez-Álvarez
- Department of Biology, Exact and Natural Sciences Division, Universidad de Guanajuato, Guanajuato, Mexico
| | - Luis M Salazar-García
- Department of Biology, Exact and Natural Sciences Division, Universidad de Guanajuato, Guanajuato, Mexico
| | - Nancy E Lozoya-Pérez
- Department of Biology, Exact and Natural Sciences Division, Universidad de Guanajuato, Guanajuato, Mexico
| | | | - Alma K Tamez-Castrellón
- Department of Biology, Exact and Natural Sciences Division, Universidad de Guanajuato, Guanajuato, Mexico
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24
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Lin L, Xu J. Fungal Pigments and Their Roles Associated with Human Health. J Fungi (Basel) 2020; 6:E280. [PMID: 33198121 PMCID: PMC7711509 DOI: 10.3390/jof6040280] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/08/2020] [Accepted: 11/09/2020] [Indexed: 12/19/2022] Open
Abstract
Fungi can produce myriad secondary metabolites, including pigments. Some of these pigments play a positive role in human welfare while others are detrimental. This paper reviews the types and biosynthesis of fungal pigments, their relevance to human health, including their interactions with host immunity, and recent progresses in their structure-activity relationships. Fungal pigments are grouped into carotenoids, melanin, polyketides, and azaphilones, etc. These pigments are phylogenetically broadly distributed. While the biosynthetic pathways for some fungal pigments are known, the majority remain to be elucidated. Understanding the genes and metabolic pathways involved in fungal pigment synthesis is essential to genetically manipulate the production of both the types and quantities of specific pigments. A variety of fungal pigments have shown wide-spectrum biological activities, including promising pharmacophores/lead molecules to be developed into health-promoting drugs to treat cancers, cardiovascular disorders, infectious diseases, Alzheimer's diseases, and so on. In addition, the mechanistic elucidation of the interaction of fungal pigments with the host immune system provides valuable clues for fighting fungal infections. The great potential of fungal pigments have opened the avenues for academia and industries ranging from fundamental biology to pharmaceutical development, shedding light on our endeavors for disease prevention and treatment.
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Affiliation(s)
- Lan Lin
- School of Life Science and Technology, Department of Bioengineering, Key Laboratory of Developmental Genes and Human Diseases (MOE), Southeast University, Nanjing 210096, Jiangsu, China;
- Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Jianping Xu
- Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada
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25
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Nitiu DS, Mallo AC, Saparrat MCN. Fungal melanins that deteriorate paper cultural heritage: An overview. Mycologia 2020; 112:859-870. [PMID: 32821020 DOI: 10.1080/00275514.2020.1788846] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Paper-based works of art and documents of cultural importance kept in museums and libraries can show notorious signs of deterioration, including foxing stains, caused by fungal colonization. Some of the main chromophore agents of fungal origin that deteriorate paper and therefore affect paper cultural heritage both aesthetically and structurally are the group of pigments called melanins. Thus, knowledge of the diversity and features of fungal melanins and of the melanization pathways of fungi growing on paper is key to removing these pigments from paper-based works of cultural importance. This review provides an approach about the current knowledge of melanins synthesized by paper-colonizing fungi, their localization in the fungal structures, and their role in the deterioration of paper. This knowledge might contribute to developing new, effective, and sustainable strategies of restoration and conservation of historical documents and works of art based on paper.
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Affiliation(s)
- Daniela S Nitiu
- Cátedra de Palinología, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, Calle 64 N° 3, CP 1900 , La Plata, Buenos Aires, Argentina.,Consejo Nacional de Ciencia y Tecnología (CONICET) , Argentina
| | - Andrea C Mallo
- Cátedra de Palinología, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, Calle 64 N° 3, CP 1900 , La Plata, Buenos Aires, Argentina.,Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC, PBA) , Argentina
| | - Mario C N Saparrat
- Consejo Nacional de Ciencia y Tecnología (CONICET) , Argentina.,Instituto de Fisiología Vegetal, Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata, Diag. 113 esq. 61, CP 1900 , La Plata, Buenos Aires, Argentina.,Instituto de Botánica Carlos Spegazzini, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, Calle 51 N° 477, CP 1900 , La Plata, Buenos Aires, Argentina.,Cátedra de Microbiología Agrícola, Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata , Av. 60, CP 1900, La Plata, Buenos Aires, Argentina
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26
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Walker LA, Munro CA. Caspofungin Induced Cell Wall Changes of Candida Species Influences Macrophage Interactions. Front Cell Infect Microbiol 2020; 10:164. [PMID: 32528900 PMCID: PMC7247809 DOI: 10.3389/fcimb.2020.00164] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 03/27/2020] [Indexed: 11/13/2022] Open
Abstract
Candida species are known to differ in their ability to cause infection and have been shown to display varied susceptibilities to antifungal drugs. Treatment with the echinocandin, caspofungin, leads to compensatory alterations in the fungal cell wall. This study was performed to compare the structure and composition of the cell walls of different Candida species alone and in response to caspofungin treatment, and to evaluate how changes at the fungal cell surface affects interactions with macrophages. We demonstrated that the length of the outer fibrillar layer varied between Candida species and that, in most cases, reduced fibril length correlated with increased exposure of β-1,3-glucan on the cell surface. Candida glabrata and Candida guilliermondii, which had naturally more β-1,3-glucan exposed on the cell surface, were phagocytosed significantly more efficiently by J774 macrophages. Treatment with caspofungin resulted in increased exposure of chitin and β-1,3-glucan on the surface of the majority of Candida species isolates that were tested, with the exception of C. glabrata and Candida parapsilosis isolates. This increase in exposure of the inner cell wall polysaccharides, in most cases, correlated with reduced uptake by macrophages and in turn, a decrease in production of TNFα. Here we show that differences in the exposure of cell wall carbohydrates and variations in the repertoire of covalently attached surface proteins of different Candida species contributes to their recognition by immune cells.
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Affiliation(s)
- Louise A Walker
- School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Carol A Munro
- School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
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27
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Full-repertoire comparison of the microscopic objects composing the human gut microbiome with sequenced and cultured communities. J Microbiol 2020; 58:377-386. [PMID: 32281049 DOI: 10.1007/s12275-020-9365-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 02/11/2020] [Accepted: 02/11/2020] [Indexed: 12/16/2022]
Abstract
The study of the human gut microbiome is essential in microbiology and infectious diseases as specific alterations in the gut microbiome might be associated with various pathologies, such as chronic inflammatory disease, intestinal infection and colorectal cancer. To identify such dysregulations, several strategies are being used to create a repertoire of the microorganisms composing the human gut microbiome. In this study, we used the "microscomics" approach, which consists of creating an ultrastructural repertoire of all the cell-like objects composing stool samples from healthy donors using transmission electron microscopy (TEM). We used TEM to screen ultrathin sections of 8 resin-embedded stool samples. After exploring hundreds of micrographs, we managed to elaborate ultrastructural categories based on morphological criteria or features. This approach explained many inconsistencies observed with other techniques, such as metagenomics and culturomics. We highlighted the value of our culture-independent approach by comparing our microscopic images to those of cultured bacteria and those reported in the literature. This study helped to detect "minimicrobes" Candidate Phyla Radiation (CPR) for the first time in human stool samples. This "microscomics" approach is non-exhaustive but complements already existing approaches and adds important data to the puzzle of the microbiota.
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28
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Yan D, Liu Y, Rong C, Song S, Zhao S, Qin L, Wang S, Gao Q. Characterization of brown film formed by Lentinula edodes. Fungal Biol 2020; 124:135-143. [DOI: 10.1016/j.funbio.2019.12.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 12/05/2019] [Accepted: 12/18/2019] [Indexed: 12/13/2022]
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29
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Chang PK, Cary JW, Lebar MD. Biosynthesis of conidial and sclerotial pigments in Aspergillus species. Appl Microbiol Biotechnol 2020; 104:2277-2286. [PMID: 31974722 DOI: 10.1007/s00253-020-10347-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/19/2019] [Accepted: 01/03/2020] [Indexed: 11/27/2022]
Abstract
Fungal pigments, which are classified as secondary metabolites, are polymerized products derived mostly from phenolic precursors with remarkable structural diversity. Pigments of conidia and sclerotia serve myriad functions. They provide tolerance against various environmental stresses such as ultraviolet light, oxidizing agents, and ionizing radiation. Some pigments even play a role in fungal pathogenesis. This review gathers available research and discusses current knowledge on the formation of conidial and sclerotial pigments in aspergilli. It examines organization of genes involved in pigment production, biosynthetic pathways, and biological functions and reevaluates some of the current dogma, especially with respect to the DHN-melanin pathway, on the production of these enigmatic polymers. A better understanding of the structure and biosynthesis of melanins and other pigments could facilitate strategies to mitigate fungal pathogenesis.
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Affiliation(s)
- Perng-Kuang Chang
- Agricultural Research Service, U. S. Department of Agriculture, Southern Regional Research Center, 1100 Robert E. Lee Boulevard, New Orleans, LA, 70124, USA.
| | - Jeffrey W Cary
- Agricultural Research Service, U. S. Department of Agriculture, Southern Regional Research Center, 1100 Robert E. Lee Boulevard, New Orleans, LA, 70124, USA.
| | - Matthew D Lebar
- Agricultural Research Service, U. S. Department of Agriculture, Southern Regional Research Center, 1100 Robert E. Lee Boulevard, New Orleans, LA, 70124, USA
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30
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Chrissian C, Camacho E, Fu MS, Prados-Rosales R, Chatterjee S, Cordero RJB, Lodge JK, Casadevall A, Stark RE. Melanin deposition in two Cryptococcus species depends on cell-wall composition and flexibility. J Biol Chem 2020; 295:1815-1828. [PMID: 31896575 DOI: 10.1074/jbc.ra119.011949] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 12/31/2019] [Indexed: 12/14/2022] Open
Abstract
Cryptococcus neoformans and Cryptococcus gattii are two species complexes in the large fungal genus Cryptococcus and are responsible for potentially lethal disseminated infections. These two complexes share several phenotypic traits, such as production of the protective compound melanin. In C. neoformans, the pigment associates with key cellular constituents that are essential for melanin deposition within the cell wall. Consequently, melanization is modulated by changes in cell-wall composition or ultrastructure. However, whether similar factors influence melanization in C. gattii is unknown. Herein, we used transmission EM, biochemical assays, and solid-state NMR spectroscopy of representative isolates and "leaky melanin" mutant strains from each species complex to examine the compositional and structural factors governing cell-wall pigment deposition in C. neoformans and C. gattii. The principal findings were the following. 1) C. gattii R265 had an exceptionally high chitosan content compared with C. neoformans H99; a rich chitosan composition promoted homogeneous melanin distribution throughout the cell wall but did not increase the propensity of pigment deposition. 2) Strains from both species manifesting the leaky melanin phenotype had reduced chitosan content, which was compensated for by the production of lipids and other nonpolysaccharide constituents that depended on the species or mutation. 3) Changes in the relative rigidity of cell-wall chitin were associated with aberrant pigment retention, implicating cell-wall flexibility as an independent variable in cryptococcal melanin assembly. Overall, our results indicate that cell-wall composition and molecular architecture are critical factors for the anchoring and arrangement of melanin pigments in both C. neoformans and C. gattii species complexes.
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Affiliation(s)
- Christine Chrissian
- Department of Chemistry and Biochemistry, City College of New York and CUNY Institute for Macromolecular Assemblies, New York, New York 10031; Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, New York 10016
| | - Emma Camacho
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205
| | - Man Shun Fu
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205
| | - Rafael Prados-Rosales
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Yeshiva University, Bronx, New York 10033; Department of Preventive Medicine and Public Health and Microbiology, Autonoma University of Madrid, 28049 Madrid, Spain
| | - Subhasish Chatterjee
- Department of Chemistry and Biochemistry, City College of New York and CUNY Institute for Macromolecular Assemblies, New York, New York 10031
| | - Radames J B Cordero
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205
| | - Jennifer K Lodge
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205
| | - Ruth E Stark
- Department of Chemistry and Biochemistry, City College of New York and CUNY Institute for Macromolecular Assemblies, New York, New York 10031; Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, New York 10016; Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, New York 10016.
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31
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Abstract
Melanins are dark green, brown, or black pigments that serve as antioxidant, reactive oxygen species (ROS) scavengers that protect fungal pathogens from radiation and host immune responses. Cryptococcus neoformans, the major etiological agent of fungal meningoencephalitis, also utilizes melanin as a key virulence factor. In this basidiomycete pathogen, melanin production is regulated by the cAMP and high-osmolarity glycerol response (HOG) pathways, and yet its complex signaling networks remain poorly described. In this study, we uncovered novel melanin synthesis regulatory networks consisting of core transcription factors (TFs), including Bzp4, Usv101, Hob1, and Mbs1, and core kinases Gsk3 and Kic1. These networks were identified through coupling systematic analyses of the expression and epistatic relationships of TF and kinase mutant libraries in the presence of diverse melanin substrates with transcriptome profiling of the core TF mutants. Thus, this report provides comprehensive insight into the melanin-regulating pathways in C. neoformans and other fungal pathogens. Melanin is an antioxidant polyphenol pigment required for the pathogenicity of many fungal pathogens, but comprehensive regulatory mechanisms remain unidentified. In this study, we systematically analyzed melanin-regulating signaling pathways in Cryptococcus neoformans and identified four melanin-regulating core transcription factors (TFs), Bzp4, Usv101, Mbs1, and Hob1, required for induction of the laccase gene (LAC1). Bzp4, Usv101, and Mbs1 independently regulate LAC1 induction, whereas Hob1 controls Bzp4 and Usv101 expression. Both Bzp4 and Usv101 are localized in the cytoplasm under nutrient-rich conditions (i.e., in the presence of yeast extract-peptone-dextrose [YPD] medium) but translocate into the nucleus upon nutrient starvation (i.e., in the presence of yeast nitrogen base [YNB] medium without glucose), and Mbs1 is constitutively localized in the nucleus. Notably, the cAMP pathway is not involved in regulation of the four TFs, but the high-osmolarity glycerol response (HOG) pathway negatively regulates induction of BZP4 and LAC1. Next, we searched for potential kinases upstream of the core TFs and identified nine core kinases; their deletion led to defective melanin production and LAC1 induction. Deletion of GSK3 or KIC1 abolished induction of LAC1 and BZP4 and perturbed nuclear translocation of Bzp4. Notably, Gsk3 also regulated expression of HOB1, USV101, and MBS1, indicating that it is a critical melanin-regulating kinase. Finally, an RNA sequencing-based transcriptome analysis of the wild-type strain and of bzp4Δ, usv101Δ, hob1Δ, and mbs1Δ strains under nutrient-rich and nutrient-starved conditions revealed that the melanin-regulating core TFs govern redundant and distinct classes of genes involved in a variety of biological processes.
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The Role of Melanin in Fungal Pathogenesis for Animal Hosts. Curr Top Microbiol Immunol 2019; 422:1-30. [PMID: 31278515 DOI: 10.1007/82_2019_173] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Melanins are a class of pigments that are ubiquitous throughout biology. They play incredibly diverse and important roles ranging from radiation protection to immune defense, camouflage, and virulence. Fungi have evolved to use melanin to be able to persist in the environment and within organisms. Fungal melanins are often located within the cell well and are able to neutralize reactive oxygen species and other radicals, defend against UV radiation, bind and sequester non-specific peptides and compounds, and produce a physical barrier that defends the cell. For this reason, melanized fungi are often well-suited to be human pathogens-melanin allows fungi to neutralize the microbicidal oxidative bursts of our innate immune system, bind and inactivate to antimicrobial peptides and enzymes, sequester antifungal pharmaceuticals, and create a shield to block immune recognition of the fungus. Due to the importance and pervasiveness of melanin in fungal virulence, mammalian immune systems have evolved antifungal strategies that involve directly detecting and binding to fungal melanins. Such strategies include the use of melanin-specific antibody responses and C-type lectins like the newly discovered melanin-specific MelLec receptor.
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33
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Camacho E, Vij R, Chrissian C, Prados-Rosales R, Gil D, O'Meally RN, Cordero RJB, Cole RN, McCaffery JM, Stark RE, Casadevall A. The structural unit of melanin in the cell wall of the fungal pathogen Cryptococcus neoformans. J Biol Chem 2019; 294:10471-10489. [PMID: 31118223 PMCID: PMC6615676 DOI: 10.1074/jbc.ra119.008684] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/19/2019] [Indexed: 11/06/2022] Open
Abstract
Melanins are synthesized macromolecules that are found in all biological kingdoms. These pigments have a myriad of roles that range from microbial virulence to key components of the innate immune response in invertebrates. Melanins also exhibit unique properties with potential applications in physics and material sciences, ranging from electrical batteries to novel therapeutics. In the fungi, melanins, such as eumelanins, are components of the cell wall that provide protection against biotic and abiotic elements. Elucidation of the smallest fungal cell wall-associated melanin unit that serves as a building block is critical to understand the architecture of these polymers, its interaction with surrounding components, and their functional versatility. In this study, we used isopycnic gradient sedimentation, NMR, EPR, high-resolution microscopy, and proteomics to analyze the melanin in the cell wall of the human pathogenic fungus Cryptococcus neoformans We observed that melanin is assembled into the cryptococcal cell wall in spherical structures ∼200 nm in diameter, termed melanin granules, which are in turn composed of nanospheres ∼30 nm in diameter, termed fungal melanosomes. We noted that melanin granules are closely associated with proteins that may play critical roles in the fungal melanogenesis and the supramolecular structure of this polymer. Using this structural information, we propose a model for C. neoformans' melanization that is similar to the process used in animal melanization and is consistent with the phylogenetic relatedness of the fungal and animal kingdoms.
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Affiliation(s)
- Emma Camacho
- From the Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, Maryland 21205
| | - Raghav Vij
- From the Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, Maryland 21205
| | - Christine Chrissian
- the Department of Chemistry and Biochemistry, City College of New York and CUNY Institute for Macromolecular Assemblies, New York, New York 10031, the City University of New York
- Ph.D. Programs in Biochemistry and
| | - Rafael Prados-Rosales
- the Department of Microbiology and Immunology, Albert Einstein College of Medicine, Yeshiva University, Bronx, New York 10461
- the CIC bioGUNE, 48160 Derio, Vizcaya, Spain
- the Department of Preventive Medicine and Public Health and Microbiology, Autonoma University of Madrid, 28049 Madrid, Spain
| | - David Gil
- the CIC bioGUNE, 48160 Derio, Vizcaya, Spain
| | - Robert N O'Meally
- the Johns Hopkins Mass Spectrometry and Proteomic Facility, The Johns Hopkins University, Baltimore, Maryland 21205, and
| | - Radames J B Cordero
- From the Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, Maryland 21205
| | - Robert N Cole
- the Johns Hopkins Mass Spectrometry and Proteomic Facility, The Johns Hopkins University, Baltimore, Maryland 21205, and
| | - J Michael McCaffery
- the Integrated Imaging Center, Department of Biology, Engineering in Oncology Center, and Institute for NanoBioTechnology, The Johns Hopkins University, Baltimore, Maryland 21218
| | - Ruth E Stark
- the Department of Chemistry and Biochemistry, City College of New York and CUNY Institute for Macromolecular Assemblies, New York, New York 10031, the City University of New York
- Ph.D. Programs in Biochemistry and
- Chemistry, New York, New York 10016
| | - Arturo Casadevall
- From the Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, Maryland 21205,
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John CN, Abrantes PMDS, Prusty BK, Ablashi DV, Africa CWJ. K21 Compound, a Potent Antifungal Agent: Implications for the Treatment of Fluconazole-Resistant HIV-Associated Candida Species. Front Microbiol 2019; 10:1021. [PMID: 31231313 PMCID: PMC6558409 DOI: 10.3389/fmicb.2019.01021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 04/24/2019] [Indexed: 11/13/2022] Open
Abstract
Background/Objectives: With mucocutaneous candidiasis being highly prevalent in HIV patients, the emergence of fluconazole-resistant Candida species forms a major challenge in treating and eradicating these infections. The objective of this study was to establish the antifungal activity of K21, a membrane-rupturing antimicrobial compound derived from a silica quaternary ammonium compound (SiQAC) with tetraethoxysilane (TEOS). Methods: The study sample included 81 Candida species of which 9 were type strains and 72 were clinical isolates. Minimum inhibitory concentrations, synergy, fractional inhibitory concentration index (FICI), and time kill assays were determined by broth microdilution. Electron microscopy (EM) was used to determine the qualitative changes brought about after treatment with K21. Results: K21 inhibited the growth of all fluconazole-resistant and susceptible Candida strains with only 2 h of exposure required to effectively kill 99.9% of the inoculum, and a definite synergistic effect was observed with a combination of K21 and fluconazole. EM demonstrated the presence of two forms of extracellular vesicles indicative of biofilm formation and cell lysis. Conclusion: The study established the efficacy of K21 as an antifungal agent and with fluconazole-resistant candidiasis on the increase, the development of K21 can provide a promising alternative to combat acquired drug resistance.
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Affiliation(s)
- Cathy N. John
- Maternal Endogenous Infections Studies (MEnIS) Research Laboratories, Department of Medical Biosciences, University of the Western Cape, Bellville, South Africa
| | - Pedro M. D. S. Abrantes
- Maternal Endogenous Infections Studies (MEnIS) Research Laboratories, Department of Medical Biosciences, University of the Western Cape, Bellville, South Africa
| | - Bhupesh K. Prusty
- Institute for Virology and Immunobiology, University of Wuerzburg, Wuerzburg, Germany
| | | | - Charlene W. J. Africa
- Maternal Endogenous Infections Studies (MEnIS) Research Laboratories, Department of Medical Biosciences, University of the Western Cape, Bellville, South Africa
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35
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Pacelli C, Bryan RA, Onofri S, Selbmann L, Zucconi L, Shuryak I, Dadachova E. Survival and redox activity of Friedmanniomyces endolithicus, an Antarctic endemic black meristematic fungus, after gamma rays exposure. Fungal Biol 2018; 122:1222-1227. [PMID: 30449360 DOI: 10.1016/j.funbio.2018.10.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 10/08/2018] [Accepted: 10/12/2018] [Indexed: 11/29/2022]
Abstract
Despite living organisms are not exposed to acute ionizing radiation under natural conditions, some exhibit a high radiation resistance. Understanding this phenomenon is important for assessing the impact of radiation-related accidents, occupational exposures and space missions. In this context, in this study we analyzed the effect of gamma rays on the Antarctic cryptoendolithic melanized fungus Friedmanniomyces endolithicus CCFEE 5208 and demonstrated its resistance to acute doses of gamma radiation (up to 400 Gy), accompanied by increase in metabolic activity.
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Affiliation(s)
- Claudia Pacelli
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy; Albert Einstein College of Medicine, Bronx, New York, USA
| | - Ruth A Bryan
- Albert Einstein College of Medicine, Bronx, New York, USA
| | - Silvano Onofri
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy.
| | - Laura Selbmann
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy; Italian National Antarctic Museum (MNA), Mycological Section, Genoa, Italy
| | - Laura Zucconi
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Igor Shuryak
- Center for Radiological Research, Columbia University, New York, USA
| | - Ekaterina Dadachova
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada
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36
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Perez-Dulzaides R, Camacho E, Cordero RJB, Casadevall A. Cell-wall dyes interfere with Cryptococcus neoformans melanin deposition. MICROBIOLOGY (READING, ENGLAND) 2018; 164:1012-1022. [PMID: 29939127 PMCID: PMC6152417 DOI: 10.1099/mic.0.000682] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Melanization is an intrinsic characteristic of many fungal species, but details of this process are poorly understood because melanins are notoriously difficult pigments to study. While studying the binding of cell-wall dyes, Eosin Y or Uvitex, to melanized and non-melanized Cryptococcus neoformans cells we noted that melanization leads to reduced fluorescence intensity, suggesting that melanin interfered with dye binding to the cell wall. The growth of C. neoformans in melanizing conditions with either of the cell-wall dyes resulted in an increase in supernatant-associated melanin, consistent with blockage of melanin attachment to the cell wall. This effect provided the opportunity to characterize melanin released into culture supernatants. Released melanin particles appeared mostly as networked structures having dimensions consistent with previously described extracellular vesicles. Hence, dye binding to the cell wall created conditions that resembled the 'leaky melanin' phenotype described for certain cell-wall mutants. In agreement with earlier studies on fungal melanins biosynthesis, our observations are supportive of a model whereby C. neoformans melanization proceeds by the attachment of melanin nanoparticles to the cell wall through chitin, chitosan, and various glucans.
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Affiliation(s)
- Ricardo Perez-Dulzaides
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Emma Camacho
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Radames J. B. Cordero
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA,*Correspondence: Arturo Casadevall,
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Szilágyi M, Anton F, Pócsi I, Emri T. Autolytic enzymes are responsible for increased melanization of carbon stressed Aspergillus nidulans cultures. J Basic Microbiol 2018; 58:440-447. [PMID: 29266292 DOI: 10.1002/jobm.201700545] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 11/21/2017] [Accepted: 11/30/2017] [Indexed: 11/11/2022]
Abstract
Melanization of carbon stressed Aspergillus nidulans cultures were studied. Melanin production showed strong positive correlation with the activity of the secreted chitinase and ß-1,3-glucanase. Deletion of either chiB encoding an autolytic endochitinase or engA encoding an autolytic ß-1,3-endoglucanase, or both, almost completely prevented melanization of carbon stressed cultures. In contrast, addition of Trichoderma lyticase to cultures induced melanin production. Synthetic melanin could efficiently inhibit the purified ChiB chitinase activity. It could also efficiently decrease the intensity of hyphal fragmentation and pellet disorganization in Trichoderma lyticase treated cultures. Glyphosate, an inhibitor of L-3,4-dihydroxyphenylalanine-type melanin synthesis, could prevent melanization of carbon-starved cultures and enhanced pellet disorganization, while pyroquilon, a 1,8-dihydroxynaphthalene-type melanin synthesis inhibitor, enhanced melanization, and prevented pellet disorganization. We concluded that cell wall stress induced by autolytic cell wall hydrolases was responsible for melanization of carbon-starved cultures. The produced melanin can shield the living cells but may not inhibit the degradation and reutilization of cell wall materials of dead hyphae. Controlling the activity of autolytic hydrolase production can be an efficient approach to prevent unwanted melanization in the fermentation industry, while applying melanin synthesis inhibitors can decrease the resistance of pathogenic fungi against the chitinases produced by the host organism.
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Affiliation(s)
- Melinda Szilágyi
- Faculty of Science and Technology, Department of Biotechnology and Microbiology, University of Debrecen, Debrecen, Hungary
| | - Fruzsina Anton
- Faculty of Science and Technology, Department of Biotechnology and Microbiology, University of Debrecen, Debrecen, Hungary
| | - István Pócsi
- Faculty of Science and Technology, Department of Biotechnology and Microbiology, University of Debrecen, Debrecen, Hungary
| | - Tamás Emri
- Faculty of Science and Technology, Department of Biotechnology and Microbiology, University of Debrecen, Debrecen, Hungary
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Walker L, Sood P, Lenardon MD, Milne G, Olson J, Jensen G, Wolf J, Casadevall A, Adler-Moore J, Gow NAR. The Viscoelastic Properties of the Fungal Cell Wall Allow Traffic of AmBisome as Intact Liposome Vesicles. mBio 2018; 9:e02383-17. [PMID: 29437927 PMCID: PMC5801470 DOI: 10.1128/mbio.02383-17] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 01/08/2018] [Indexed: 01/25/2023] Open
Abstract
The fungal cell wall is a critically important structure that represents a permeability barrier and protective shield. We probed Candida albicans and Cryptococcus neoformans with liposomes containing amphotericin B (AmBisome), with or without 15-nm colloidal gold particles. The liposomes have a diameter of 60 to 80 nm, and yet their mode of action requires them to penetrate the fungal cell wall to deliver amphotericin B to the cell membrane, where it binds to ergosterol. Surprisingly, using cryofixation techniques with electron microscopy, we observed that the liposomes remained intact during transit through the cell wall of both yeast species, even though the predicted porosity of the cell wall (pore size, ~5.8 nm) is theoretically too small to allow these liposomes to pass through intact. C. albicans mutants with altered cell wall thickness and composition were similar in both their in vitro AmBisome susceptibility and the ability of liposomes to penetrate the cell wall. AmBisome exposed to ergosterol-deficient C. albicans failed to penetrate beyond the mannoprotein-rich outer cell wall layer. Melanization of C. neoformans and the absence of amphotericin B in the liposomes were also associated with a significant reduction in liposome penetration. Therefore, AmBisome can reach cell membranes intact, implying that fungal cell wall viscoelastic properties are permissive to vesicular structures. The fact that AmBisome can transit through chemically diverse cell wall matrices when these liposomes are larger than the theoretical cell wall porosity suggests that the wall is capable of rapid remodeling, which may also be the mechanism for release of extracellular vesicles.IMPORTANCE AmBisome is a broad-spectrum fungicidal antifungal agent in which the hydrophobic polyene antibiotic amphotericin B is packaged within a 60- to 80-nm liposome. The mode of action involves perturbation of the fungal cell membrane by selectively binding to ergosterol, thereby disrupting membrane function. We report that the AmBisome liposome transits through the cell walls of both Candida albicans and Cryptococcus neoformans intact, despite the fact that the liposome is larger than the theoretical cell wall porosity. This implies that the cell wall has deformable, viscoelastic properties that are permissive to transwall vesicular traffic. These observations help explain the low toxicity of AmBisome, which can deliver its payload directly to the cell membrane without unloading the polyene in the cell wall. In addition, these findings suggest that extracellular vesicles may also be able to pass through the cell wall to deliver soluble and membrane-bound effectors and other molecules to the extracellular space.
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Affiliation(s)
- Louise Walker
- Aberdeen Fungal Group, Institute of Medical Sciences, Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
| | - Prashant Sood
- Aberdeen Fungal Group, Institute of Medical Sciences, Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
| | - Megan D Lenardon
- Aberdeen Fungal Group, Institute of Medical Sciences, Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Gillian Milne
- Aberdeen Fungal Group, Institute of Medical Sciences, Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
| | - Jon Olson
- Gilead Sciences Inc., San Dimas, California, USA
| | | | - Julie Wolf
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Arturo Casadevall
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | | | - Neil A R Gow
- Aberdeen Fungal Group, Institute of Medical Sciences, Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
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Camacho E, Chrissian C, Cordero RJB, Liporagi-Lopes L, Stark RE, Casadevall A. N-acetylglucosamine affects Cryptococcus neoformans cell-wall composition and melanin architecture. MICROBIOLOGY-SGM 2017; 163:1540-1556. [PMID: 29043954 DOI: 10.1099/mic.0.000552] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Cryptococcus neoformans is an environmental fungus that belongs to the phylum Basidiomycetes and is a major pathogen in immunocompromised patients. The ability of C. neoformans to produce melanin pigments represents its second most important virulence factor, after the presence of a polysaccharide capsule. Both the capsule and melanin are closely associated with the fungal cell wall, a complex structure that is essential for maintaining cell morphology and viability under conditions of stress. The amino sugar N-acetylglucosamine (GlcNAc) is a key constituent of the cell-wall chitin and is used for both N-linked glycosylation and GPI anchor synthesis. Recent studies have suggested additional roles for GlcNAc as an activator and mediator of cellular signalling in fungal and plant cells. Furthermore, chitin and chitosan polysaccharides interact with melanin pigments in the cell wall and have been found to be essential for melanization. Despite the importance of melanin, its molecular structure remains unresolved; however, we previously obtained critical insights using advanced nuclear magnetic resonance (NMR) and imaging techniques. In this study, we investigated the effect of GlcNAc supplementation on cryptococcal cell-wall composition and melanization. C. neoformans was able to metabolize GlcNAc as a sole source of carbon and nitrogen, indicating a capacity to use a component of a highly abundant polymer in the biospherenutritionally. C. neoformans cells grown with GlcNAc manifested changes in the chitosan cell-wall content, cell-wall thickness and capsule size. Supplementing cultures with isotopically 15N-labelled GlcNAc demonstrated that the exogenous monomer serves as a building block for chitin/chitosan and is incorporated into the cell wall. The altered chitin-to-chitosan ratio had no negative effects on the mother-daughter cell separation; growth with GlcNAc affected the fungal cell-wall scaffold, resulting in increased melanin deposition and assembly. In summary, GlcNAc supplementation had pleiotropic effects on cell-wall and melanin architectures, and thus established its capacity to perturb these structures, a property that could prove useful for metabolic tracking studies.
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Affiliation(s)
- Emma Camacho
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Christine Chrissian
- PhD Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, USA.,Department of Chemistry and Biochemistry and CUNY Institute for Macromolecular Assemblies, The City College of New York, New York, NY, USA
| | - Radames J B Cordero
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Livia Liporagi-Lopes
- Faculdade de Farmácia, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Ruth E Stark
- PhD Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, USA.,Department of Chemistry and Biochemistry and CUNY Institute for Macromolecular Assemblies, The City College of New York, New York, NY, USA.,PhD Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, USA
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
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Abstract
The molecular composition of the cell wall is critical for the biology and ecology of each fungal species. Fungal walls are composed of matrix components that are embedded and linked to scaffolds of fibrous load-bearing polysaccharides. Most of the major cell wall components of fungal pathogens are not represented in humans, other mammals, or plants, and therefore the immune systems of animals and plants have evolved to recognize many of the conserved elements of fungal walls. For similar reasons the enzymes that assemble fungal cell wall components are excellent targets for antifungal chemotherapies and fungicides. However, for fungal pathogens, the cell wall is often disguised since key signature molecules for immune recognition are sometimes masked by immunologically inert molecules. Cell wall damage leads to the activation of sophisticated fail-safe mechanisms that shore up and repair walls to avoid catastrophic breaching of the integrity of the surface. The frontiers of research on fungal cell walls are moving from a descriptive phase defining the underlying genes and component parts of fungal walls to more dynamic analyses of how the various components are assembled, cross-linked, and modified in response to environmental signals. This review therefore discusses recent advances in research investigating the composition, synthesis, and regulation of cell walls and how the cell wall is targeted by immune recognition systems and the design of antifungal diagnostics and therapeutics.
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Hernández-Chávez MJ, Pérez-García LA, Niño-Vega GA, Mora-Montes HM. Fungal Strategies to Evade the Host Immune Recognition. J Fungi (Basel) 2017; 3:jof3040051. [PMID: 29371567 PMCID: PMC5753153 DOI: 10.3390/jof3040051] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 09/18/2017] [Accepted: 09/19/2017] [Indexed: 12/23/2022] Open
Abstract
The recognition of fungal cells by the host immune system is key during the establishment of a protective anti-fungal response. Even though the immune system has evolved a vast number of processes to control these organisms, they have developed strategies to fight back, avoiding the proper recognition by immune components and thus interfering with the host protective mechanisms. Therefore, the strategies to evade the immune system are as important as the virulence factors and attributes that damage the host tissues and cells. Here, we performed a thorough revision of the main fungal tactics to escape from the host immunosurveillance processes. These include the composition and organization of the cell wall, the fungal capsule, the formation of titan cells, biofilms, and asteroid bodies; the ability to undergo dimorphism; and the escape from nutritional immunity, extracellular traps, phagocytosis, and the action of humoral immune effectors.
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Affiliation(s)
- Marco J Hernández-Chávez
- Departamento de Biología, División de Ciencias Naturales y Exactas, Campus Guanajuato, Universidad de Guanajuato, Noria Alta s/n, col. Noria Alta, C.P., Guanajuato Gto. 36050, México.
| | - Luis A Pérez-García
- Unidad Académica Multidisciplinaria Zona Huasteca, Universidad Autónoma de San Luis Potosí, Romualdo del Campo 501, Fracc. Rafael Curiel, C.P., Cd. Valle SLP. 79060, México.
| | - Gustavo A Niño-Vega
- Departamento de Biología, División de Ciencias Naturales y Exactas, Campus Guanajuato, Universidad de Guanajuato, Noria Alta s/n, col. Noria Alta, C.P., Guanajuato Gto. 36050, México.
| | - Héctor M Mora-Montes
- Departamento de Biología, División de Ciencias Naturales y Exactas, Campus Guanajuato, Universidad de Guanajuato, Noria Alta s/n, col. Noria Alta, C.P., Guanajuato Gto. 36050, México.
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Raman NM, Ramasamy S. Genetic validation and spectroscopic detailing of DHN-melanin extracted from an environmental fungus. Biochem Biophys Rep 2017; 12:98-107. [PMID: 28955797 PMCID: PMC5613234 DOI: 10.1016/j.bbrep.2017.08.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 07/27/2017] [Accepted: 08/17/2017] [Indexed: 11/30/2022] Open
Abstract
Accurate characterization of melanin using analytical methodologies has proved to be difficult due to its heterogeneity, insolubility in wide pH and broad range of solvents. The present study was undertaken to characterize melanin extracted from an environmental Aspergillus fumigatus AFGRD105 by studying its genes, chemical properties and spectral data. A gene based approach to confirm the type of melanin carried out indicated the extracted melanin to be of the dihydroxynaphthalene type. On comparison with synthetic melanin, UV–Vis and IR spectra of the extracted melanin revealed characteristic peaks that can be further used for confirmation of DHN-melanin extracted from any source. Solid state 13C NMR spectroscopy established the presence of the hydroxyl-naphthalene moiety and validated the results obtained by genetic analysis. The correct assignment of the observed spectral frequency characteristic of functional groups can be further adapted in future works that deal with binding capacities and biomolecule systems involving melanin. DNA was extracted by a standardised protocol that can be adapted for environmental and clinically isolated fungi. The presence of genes was used to identify the type of melanin. Physico chemical characterization of the melanin extracted was performed. UV–Vis and IR spectra were used to confirm the type of melanin. Further, the chemical moieties were substantiated using 13C solid state NMR spectroscopy.
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Affiliation(s)
- Nitya Meenakshi Raman
- Department of Biotechnology, Dr. G. R. Damodaran College of Science, Bharathiar University, Coimbatore 641014, India
| | - Suganthi Ramasamy
- Department of Biotechnology, Dr. G. R. Damodaran College of Science, Bharathiar University, Coimbatore 641014, India
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Zhang P, Wang X, Fan A, Zheng Y, Liu X, Wang S, Zou H, Oakley BR, Keller NP, Yin WB. A cryptic pigment biosynthetic pathway uncovered by heterologous expression is essential for conidial development inPestalotiopsis fici. Mol Microbiol 2017; 105:469-483. [DOI: 10.1111/mmi.13711] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/15/2017] [Indexed: 01/15/2023]
Affiliation(s)
- Peng Zhang
- State Key Laboratory of Mycology; Institute of Microbiology, Chinese Academy of Sciences; Beijing People's Republic of China
- College of Life Science, University of Chinese Academy of Sciences; Beijing People's Republic of China
| | - Xiuna Wang
- State Key Laboratory of Mycology; Institute of Microbiology, Chinese Academy of Sciences; Beijing People's Republic of China
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences; Fujian Agriculture and Forestry University; Fuzhou People's Republic of China
| | - Aili Fan
- State Key Laboratory of Mycology; Institute of Microbiology, Chinese Academy of Sciences; Beijing People's Republic of China
| | - Yanjing Zheng
- Zhejiang Provincial (Wenzhou) Key Lab for Water Environment and Marine Biological Resources Protection, College of Life and Environmental Science; Wenzhou University; Wenzhou People's Republic of China
| | - Xingzhong Liu
- State Key Laboratory of Mycology; Institute of Microbiology, Chinese Academy of Sciences; Beijing People's Republic of China
| | - Shihua Wang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences; Fujian Agriculture and Forestry University; Fuzhou People's Republic of China
| | - Huixi Zou
- Zhejiang Provincial (Wenzhou) Key Lab for Water Environment and Marine Biological Resources Protection, College of Life and Environmental Science; Wenzhou University; Wenzhou People's Republic of China
| | - Berl R. Oakley
- Department of Molecular Biosciences; University of Kansas; Lawrence KS USA
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology; University of Wisconsin-Madison; Madison Wisconsin, WI USA
| | - Wen-Bing Yin
- State Key Laboratory of Mycology; Institute of Microbiology, Chinese Academy of Sciences; Beijing People's Republic of China
- College of Life Science, University of Chinese Academy of Sciences; Beijing People's Republic of China
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Camacho E, Niño-Vega GA. Paracoccidioides Spp.: Virulence Factors and Immune-Evasion Strategies. Mediators Inflamm 2017; 2017:5313691. [PMID: 28553014 PMCID: PMC5434249 DOI: 10.1155/2017/5313691] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 02/01/2017] [Accepted: 02/21/2017] [Indexed: 12/21/2022] Open
Abstract
Paracoccidioides spp. are dimorphic fungal pathogens responsible for one of the most relevant systemic mycoses in Latin America, paracoccidioidomycosis (PCM). Their exact ecological niche remains unknown; however, they have been isolated from soil samples and armadillos (Dasypus novemcinctus), which have been proposed as animal reservoir for these fungi. Human infection occurs by inhalation of conidia or mycelia fragments and is mostly associated with immunocompetent hosts inhabiting and/or working in endemic rural areas. In this review focusing on the pathogen perspective, we will discuss some of the microbial attributes and molecular mechanisms that enable Paracoccidioides spp. to tolerate, adapt, and ultimately avoid the host immune response, establishing infection.
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Affiliation(s)
- Emma Camacho
- Department of Molecular Microbiology and Immunobiology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Gustavo A. Niño-Vega
- Departamento de Biología, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Guanajuato, GTO, Mexico
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Gomes-Junior RA, da Silva RS, de Lima RG, Vannier-Santos MA. Antifungal mechanism of [RuIII(NH3)4catechol]+ complex on fluconazole-resistant Candida tropicalis. FEMS Microbiol Lett 2017; 364:3586774. [PMID: 28402525 DOI: 10.1093/femsle/fnx073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 04/10/2017] [Indexed: 12/25/2022] Open
Abstract
Candidiasis, a major opportunistic mycosis caused by Candida sp., may comprise life-threatening systemic infections. The incidence of non-albicans species is rising, particularly in South America and they are frequently drug resistant, causing unresponsive cases. Thus, novel antimycotic agents are required. Here we tested the antifungal activity of [RuIII(NH3)4catechol]+ complex (RuCat), approaching possible action mechanisms on fluconazole-resistant Candida tropicalis. RuCat significantly (P < 0.05) inhibited the growth and viability of C. tropicalis dose-dependently (IC50 20.3 μM). Cytotoxicity of RuCat upon murine splenocytes was lower (Selectivity Index = 16). Scanning electron microscopy analysis showed pseudohyphae formation, yeast aggregation and surface damage. RuCat-treated samples investigated by transmission electron microscopy showed melanin granule trafficking to cell surfaces and extracellular milieu. Surface-adherent membrane fragments and extracellular debris were also observed. RuCat treatment produced intense H2DCFDA labeling, indicating reactive oxygen species (ROS) production which caused increased lipoperoxidation. ROS are involved in the fungicidal effect as N-acetyl-L-cysteine completely restored cell viability. Calcofluor White chitin staining suggests that 70 or 140 μM RuCat treatment for 2 h affected cell-wall structure. PI labeling indicated necrotic cell death. The present data indicate that RuCat triggers ROS production, lipoperoxidation and cell surface damage, culminating in selective necrotic death of drug-resistant C. tropicalis.
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Affiliation(s)
| | - Roberto Santana da Silva
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café s/n, 14040-903, Ribeirão Preto, SP, Brazil
| | - Renata Galvão de Lima
- Faculdade de Ciências Integradas do Pontal, Universidade Federal de Uberlândia, Rua Vinte, 1600, Tupã, Ituiutaba, MG, Brazil
| | - Marcos A Vannier-Santos
- Gonçalo Moniz Institute, Oswaldo Cruz Foundation (FIOCRUZ), Salvador, CEP 40295-00, BA, Brazil
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Abstract
The molecular composition of the cell wall is critical for the biology and ecology of each fungal species. Fungal walls are composed of matrix components that are embedded and linked to scaffolds of fibrous load-bearing polysaccharides. Most of the major cell wall components of fungal pathogens are not represented in humans, other mammals, or plants, and therefore the immune systems of animals and plants have evolved to recognize many of the conserved elements of fungal walls. For similar reasons the enzymes that assemble fungal cell wall components are excellent targets for antifungal chemotherapies and fungicides. However, for fungal pathogens, the cell wall is often disguised since key signature molecules for immune recognition are sometimes masked by immunologically inert molecules. Cell wall damage leads to the activation of sophisticated fail-safe mechanisms that shore up and repair walls to avoid catastrophic breaching of the integrity of the surface. The frontiers of research on fungal cell walls are moving from a descriptive phase defining the underlying genes and component parts of fungal walls to more dynamic analyses of how the various components are assembled, cross-linked, and modified in response to environmental signals. This review therefore discusses recent advances in research investigating the composition, synthesis, and regulation of cell walls and how the cell wall is targeted by immune recognition systems and the design of antifungal diagnostics and therapeutics.
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Affiliation(s)
- Neil A R Gow
- Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB252ZD, United Kingdom
| | | | - Carol A Munro
- Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB252ZD, United Kingdom
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Abstract
ABSTRACT
Melanin pigments are found in many diverse fungal species, where they serve a variety of functions that promote fitness and cell survival. Melanotic fungi inhabit some of the most extreme habitats on earth such as the damaged nuclear reactor at Chernobyl and the highlands of Antarctica, both of which are high-radiation environments. Melanotic fungi migrate toward radioactive sources, which appear to enhance their growth. This phenomenon, combined with the known capacities of melanin to absorb a broad spectrum of electromagnetic radiation and transduce this radiation into other forms of energy, raises the possibility that melanin also functions in harvesting such energy for biological usage. The ability of melanotic fungi to harness electromagnetic radiation for physiological processes has enormous implications for biological energy flows in the biosphere and for exobiology, since it provides new mechanisms for survival in extraterrestrial conditions. Whereas some features of the way melanin-related energy transduction works can be discerned by linking various observations and circumstantial data, the mechanistic details remain to be discovered.
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Abstract
Melanins are ancient biological pigments found in all kingdoms of life. In fungi, their role in microbial pathogenesis is well established; however, these complex biomolecules also confer upon fungal microorganisms the faculty to tolerate extreme environments such as the Earth's poles, the International Space Station and places contaminated by toxic metals and ionizing radiation. A remarkable property of melanin is its capacity to interact with a wide range of electromagnetic radiation frequencies, functioning as a protecting and energy harvesting pigment. Other roles of fungal melanin include scavenging of free radical, thermo-tolerance, metal ion sequestration, cell development, and mechanical-chemical cellular strength. In this review, we explore the various functions ascribed to this biological pigment in fungi and its remarkable physicochemical properties.
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Affiliation(s)
- Radames JB Cordero
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
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Almeida-Paes R, Borba-Santos LP, Rozental S, Marco S, Zancopé-Oliveira RM, da Cunha MML. Melanin biosynthesis in pathogenic species of Sporothrix. FUNGAL BIOL REV 2017. [DOI: 10.1016/j.fbr.2016.09.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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50
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Hirota K, Yumoto H, Sapaar B, Matsuo T, Ichikawa T, Miyake Y. Pathogenic factors in Candida biofilm-related infectious diseases. J Appl Microbiol 2016; 122:321-330. [PMID: 27770500 DOI: 10.1111/jam.13330] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 10/11/2016] [Accepted: 10/15/2016] [Indexed: 01/07/2023]
Abstract
Candida albicans is a commonly found member of the human microflora and is a major human opportunistic fungal pathogen. A perturbation of the microbiome can lead to infectious diseases caused by various micro-organisms, including C. albicans. Moreover, the interactions between C. albicans and bacteria are considered to play critical roles in human health. The major biological feature of C. albicans, which impacts human health, resides in its ability to form biofilms. In particular, the extracellular matrix (ECM) of Candida biofilm plays a multifaceted role and therefore may be considered as a highly attractive target to combat biofilm-related infectious diseases. In addition, extracellular DNA (eDNA) also plays a crucial role in Candida biofilm formation and its structural integrity and induces the morphological transition from yeast to the hyphal growth form during C. albicans biofilm development. This review focuses on pathogenic factors such as eDNA in Candida biofilm formation and its ECM production and provides meaningful information for future studies to develop a novel strategy to battle infectious diseases elicited by Candida-formed biofilm.
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Affiliation(s)
- K Hirota
- Department of Oral Microbiology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - H Yumoto
- Department of Conservative Dentistry, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - B Sapaar
- Department of Oral and Maxillofacial Prosthodontics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - T Matsuo
- Department of Conservative Dentistry, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - T Ichikawa
- Department of Oral and Maxillofacial Prosthodontics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Y Miyake
- Department of Oral Microbiology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
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