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Pires ACMDS, Carvalho AR, Vaso CO, Mendes-Giannini MJS, Singulani JDL, Fusco-Almeida AM. Influence of Zinc on Histoplasma capsulatum Planktonic and Biofilm Cells. J Fungi (Basel) 2024; 10:361. [PMID: 38786716 PMCID: PMC11122510 DOI: 10.3390/jof10050361] [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: 09/04/2023] [Revised: 10/03/2023] [Accepted: 10/09/2023] [Indexed: 05/25/2024] Open
Abstract
Histoplasma capsulatum causes a fungal respiratory disease. Some studies suggest that the fungus requires zinc to consolidate the infection. This study aimed to investigate the influence of zinc and the metal chelator TPEN on the growth of Histoplasma in planktonic and biofilm forms. The results showed that zinc increased the metabolic activity, cell density, and cell viability of planktonic growth. Similarly, there was an increase in biofilm metabolic activity but no increase in biomass or extracellular matrix production. N'-N,N,N,N-tetrakis-2-pyridylmethylethane-1,2 diamine (TPEN) dramatically reduced the same parameters in the planktonic form and resulted in a decrease in metabolic activity, biomass, and extracellular matrix production for the biofilm form. Therefore, the unprecedented observations in this study highlight the importance of zinc ions for the growth, development, and proliferation of H. capsulatum cells and provide new insights into the role of metal ions for biofilm formation in the dimorphic fungus Histoplasma, which could be a potential therapeutic strategy.
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Affiliation(s)
- Ana Carolina Moreira da Silva Pires
- Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara 14800-903, SP, Brazil; (A.R.C.); (C.O.V.); (M.J.S.M.-G.); (J.d.L.S.)
| | - Angélica Romão Carvalho
- Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara 14800-903, SP, Brazil; (A.R.C.); (C.O.V.); (M.J.S.M.-G.); (J.d.L.S.)
| | - Carolina Orlando Vaso
- Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara 14800-903, SP, Brazil; (A.R.C.); (C.O.V.); (M.J.S.M.-G.); (J.d.L.S.)
| | - Maria José Soares Mendes-Giannini
- Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara 14800-903, SP, Brazil; (A.R.C.); (C.O.V.); (M.J.S.M.-G.); (J.d.L.S.)
| | - Junya de Lacorte Singulani
- Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara 14800-903, SP, Brazil; (A.R.C.); (C.O.V.); (M.J.S.M.-G.); (J.d.L.S.)
- Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
| | - Ana Marisa Fusco-Almeida
- Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara 14800-903, SP, Brazil; (A.R.C.); (C.O.V.); (M.J.S.M.-G.); (J.d.L.S.)
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Aoki K, Yamamoto K, Ohkuma M, Sugita T, Tanaka N, Takashima M. Hyphal Growth in Trichosporon asahii Is Accelerated by the Addition of Magnesium. Microbiol Spectr 2023; 11:e0424222. [PMID: 37102973 PMCID: PMC10269644 DOI: 10.1128/spectrum.04242-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 04/10/2023] [Indexed: 04/28/2023] Open
Abstract
Fungal dimorphism involves two morphologies: a unicellular yeast cell and a multicellular hyphal form. Invasion of hyphae into human cells causes severe opportunistic infections. The transition between yeast and hyphal forms is associated with the virulence of fungi; however, the mechanism is poorly understood. Therefore, we aimed to identify factors that induce hyphal growth of Trichosporon asahii, a dimorphic basidiomycete that causes trichosporonosis. T. asahii showed poor growth and formed small cells containing large lipid droplets and fragmented mitochondria when cultivated for 16 h in a nutrient-deficient liquid medium. However, these phenotypes were suppressed via the addition of yeast nitrogen base. When T. asahii cells were cultivated in the presence of different compounds present in the yeast nitrogen base, we found that magnesium sulfate was a key factor for inducing cell elongation, and its addition dramatically restored hyphal growth in T. asahii. In T. asahii hyphae, vacuoles were enlarged, the size of lipid droplets was decreased, and mitochondria were distributed throughout the cell cytoplasm and adjacent to the cell walls. Additionally, hyphal growth was disrupted due to treatment with an actin inhibitor. The actin inhibitor latrunculin A disrupted the mitochondrial distribution even in hyphal cells. Furthermore, magnesium sulfate treatment accelerated hyphal growth in T. asahii for 72 h when the cells were cultivated in a nutrient-deficient liquid medium. Collectively, our results suggest that an increase in magnesium levels triggers the transition from the yeast to hyphal form in T. asahii. These findings will support studies on the pathogenesis of fungi and aid in developing treatments. IMPORTANCE Understanding the mechanism underlying fungal dimorphism is crucial to discern its invasion into human cells. Invasion is caused by the hyphal form rather than the yeast form; therefore, it is important to understand the mechanism of transition from the yeast to hyphal form. To study the transition mechanism, we utilized Trichosporon asahii, a dimorphic basidiomycete that causes severe trichosporonosis since there are fewer studies on T. asahii than on ascomycetes. This study suggests that an increase in Mg2+, the most abundant mineral in living cells, triggers growth of filamentous hyphae and increases the distribution of mitochondria throughout the cell cytoplasm and adjacent to the cell walls in T. asahii. Understanding the mechanism of hyphal growth triggered by Mg2+ increase will provide a model system to explore fungal pathogenicity in the future.
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Affiliation(s)
- Keita Aoki
- Laboratory of Yeast Systematics, Tokyo NODAI Research Institute, Tokyo University of Agriculture, Setagaya, Tokyo, Japan
| | - Kosuke Yamamoto
- Department of Molecular Microbiology, Faculty of Life Sciences, Tokyo University of Agriculture, Setagaya, Tokyo, Japan
| | - Moriya Ohkuma
- Japan Collection of Microorganisms, RIKEN BioResource Research Center, Tsukuba, Ibaraki, Japan
| | - Takashi Sugita
- Department of Microbiology, Meiji Pharmaceutical University, Kiyose, Tokyo, Japan
| | - Naoto Tanaka
- Department of Molecular Microbiology, Faculty of Life Sciences, Tokyo University of Agriculture, Setagaya, Tokyo, Japan
| | - Masako Takashima
- Laboratory of Yeast Systematics, Tokyo NODAI Research Institute, Tokyo University of Agriculture, Setagaya, Tokyo, Japan
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Kurakado S, Matsumoto Y, Yamada T, Shimizu K, Wakasa S, Sugita T. Tacrolimus inhibits stress responses and hyphal formation via the calcineurin signaling pathway in Trichosporon asahii. Microbiol Immunol 2023; 67:49-57. [PMID: 36398783 DOI: 10.1111/1348-0421.13039] [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: 08/05/2022] [Revised: 10/09/2022] [Accepted: 11/07/2022] [Indexed: 11/19/2022]
Abstract
The pathogenic fungus Trichosporon asahii causes fatal deep-seated mycosis in immunocompromised patients. Calcineurin, which is widely conserved in eukaryotes, regulates cell growth and various stress responses in fungi. Tacrolimus (FK506), a calcineurin inhibitor, induces sensitivity to compounds that cause stress on the cell membrane and cell wall integrity. In this study, we demonstrated that FK506 affects stress responses and hyphal formation in T. asahii. In silico structural analysis revealed that amino acid residues in the binding site of the calcineurin-FKBP12 complex that interact with FK506 are conserved in T. asahii. The growth of T. asahii was delayed by FK506 in the presence of SDS or Congo red but not in the presence of calcium chloride. FK506 also inhibited hyphal formation in T. asahii. A mutant deficient of the cnb gene, which encodes the regulatory subunit B of calcineurin, exhibited stress sensitivities on exposure to SDS and Congo red and reduced the hyphal forming ability of T. asahii. In the cnb-deficient mutant, FK506 did not increase the stress sensitivity or reduce hyphal forming ability. These results suggest that FK506 affects stress responses and hyphal formation in T. asahii via the calcineurin signaling pathway.
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Affiliation(s)
- Sanae Kurakado
- Department of Microbiology, Meiji Pharmaceutical University, Tokyo, Japan
| | - Yasuhiko Matsumoto
- Department of Microbiology, Meiji Pharmaceutical University, Tokyo, Japan
| | - Tsuyoshi Yamada
- Teikyo University Institute of Medical Mycology, Tokyo, Japan.,Asia International Institute of Infectious Disease Control, Teikyo University, Tokyo, Japan
| | - Kiminori Shimizu
- Department of Biological Science and Technology, Tokyo University of Science, Tokyo, Japan.,Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Shogo Wakasa
- Department of Microbiology, Meiji Pharmaceutical University, Tokyo, Japan
| | - Takashi Sugita
- Department of Microbiology, Meiji Pharmaceutical University, Tokyo, Japan
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Pereira LMG, Andrade ARCD, Portela FVM, Aguiar ALR, Silva BND, Moura SGB, Pergentino MLM, Rocha MFG, Sidrim JJDC, Castelo Branco DDSCM, Cordeiro RDA. Heterologous extracellular DNA facilitates the development of Trichosporon asahii and T. inkin biofilms and enhances their tolerance to antifungals. BIOFOULING 2022; 38:778-785. [PMID: 36210505 DOI: 10.1080/08927014.2022.2130788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 09/15/2022] [Accepted: 09/24/2022] [Indexed: 06/16/2023]
Abstract
Trichosporon asahii and T. inkin are emergent agents of deep-seated and disseminated infections in immunocompromised patients. The present study aimed to investigate the role of extracellular DNA (eDNA) and the enzyme deoxyribonuclease (DNase) on the structure of T. asahii and T. inkin biofilms, as well as to examine their effect on the susceptibility to antifungals. Biofilms reached maturity at 48 h; eDNA concentration in the supernatant increased over time (6 < 24 h < 48h). Exogenous eDNA increased biomass of Trichosporon biofilms at all stages of development, enhanced their tolerance to antifungals and improved their structural complexity. DNase reduced biomass, biovolume and thickness of Trichosporon biofilms, thereby rendering them more susceptibility to voriconazole. The results suggest the relevance of eDNA in the structure and antifungal susceptibility of Trichosporon biofilms and highlight the potential of DNase as adjuvant in biofilm control.
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Affiliation(s)
| | | | | | | | | | | | | | - Marcos Fábio Gadelha Rocha
- Department of Pathology and Legal Medicine, Federal University of Ceará, Fortaleza, Brazil
- School of Veterinary, State University of Ceará, Fortaleza, Brazil
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Selective Metal Chelation by a Thiosemicarbazone Derivative Interferes with Mitochondrial Respiration and Ribosome Biogenesis in Candida albicans. Microbiol Spectr 2022; 10:e0195121. [PMID: 35412374 PMCID: PMC9241695 DOI: 10.1128/spectrum.01951-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Metal chelation is generally considered as a promising antifungal approach but its specific mechanisms are unclear. Here, we identify 13 thiosemicarbazone derivatives that exert broad-spectrum antifungal activity with potency comparable or superior to that of fluconazole in vitro by screening a small compound library comprising 89 thiosemicarbazone derivatives as iron chelators. Among the hits, 19ak exhibits minimal cytotoxicity and potent activity against either azole-sensitive or azole-resistant fungal pathogens. Mechanism investigations reveal that 19ak inhibits mitochondrial respiration mainly by retarding mitochondrial respiratory chain complex I activity through iron chelation, and further reduces mitochondrial membrane potential and ATP synthesis in Candida albicans. In addition, 19ak inhibits fungal ribosome biogenesis mainly by disrupting intracellular zinc homeostasis. 19ak also stimulates the activities of antioxidant enzymes and decreases reactive oxygen species formation in C. albicans, resulting in an increase in detrimental intracellular reductive stress. However, 19ak has minor effects on mammalian cells in depleting intracellular iron and zinc. Moreover, 19ak exhibits low capacity to induce drug resistance and in vivo efficacy in a Galleria mellonella infection model. These findings uncover retarded fungal mitochondrial respiration and ribosome biogenesis as downstream effects of disruption of iron and zinc homeostasis in C. albicans and provide a basis for the thiosemicarbazone 19ak in antifungal application. IMPORTANCE The increasing incidence of fungal infections and resistance to existing antifungals call for the development of broad-spectrum antifungals with novel mechanisms of action. In this study, we demonstrate that a thiosemicarbazone derivative 19ak selectively inhibits mitochondrial respiration mainly by retarding mitochondrial respiratory chain complex I activity through iron chelation and inhibits ribosome biogenesis mainly by disrupting intracellular zinc homeostasis in C. albicans. In addition, 19ak exhibits low capacity to induce fungal resistance, minimal cytotoxicity, and in vivo antifungal efficacy. This study provides the basis of thiosemicarbazone derivative 19ak as a metal chelator for the treatment of fungal infections.
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