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Hernando-Ortiz A, Eraso E, Jauregizar N, de Groot PW, Quindós G, Mateo E. Efficacy of the combination of amphotericin B and echinocandins against Candida auris in vitro and in the Caenorhabditis elegans host model. Microbiol Spectr 2024; 12:e0208623. [PMID: 38018978 PMCID: PMC10783041 DOI: 10.1128/spectrum.02086-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 10/27/2023] [Indexed: 11/30/2023] Open
Abstract
IMPORTANCE Multidrug resistance is a rising problem among non-Candida albicans species, such as Candida auris. This therapeutic problem has been very important during the COVID-19 pandemic. The World Health Organization has included C. auris in its global priority list of health-threatening fungi, to study this emerging multidrug-resistant species and to develop effective alternative therapies. In the present study, the synergistic effect of the combination of amphotericin B and echinocandins has been demonstrated against blood isolates of C. auris. Different susceptibility responses were also observed between aggregative and non-aggregative phenotypes. The antifungal activity of these drug combinations against C. auris was also demonstrated in the Caenorhabditis elegans host model of candidiasis, confirming the suitability and usefulness of this model in the search for solutions to antimicrobial resistance.
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Affiliation(s)
- Ainara Hernando-Ortiz
- Department of Immunology, Microbiology and Parasitology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Elena Eraso
- Department of Immunology, Microbiology and Parasitology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Nerea Jauregizar
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Piet W.J. de Groot
- Regional Center for Biomedical Research, University of Castilla-La Mancha, Albacete, Spain
| | - Guillermo Quindós
- Department of Immunology, Microbiology and Parasitology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Estibaliz Mateo
- Department of Immunology, Microbiology and Parasitology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Bilbao, Spain
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Agirrezabala Z, Guruceaga X, Martin-Vicente A, Otamendi A, Fagoaga A, Fortwendel JR, Espeso EA, Etxebeste O. Identification and functional characterization of the putative members of the CTDK-1 kinase complex as regulators of growth and development in Aspergillus nidulans and Aspergillus fumigatus. mBio 2023; 14:e0245223. [PMID: 37943062 PMCID: PMC10746219 DOI: 10.1128/mbio.02452-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 10/03/2023] [Indexed: 11/10/2023] Open
Abstract
Asexual spores are the main vehicle used by fungi to disperse to new niches. The Eurotiomycete Aspergillus nidulans is the main reference for the study of the genetic/molecular control of asexual development. In this species, Flb proteins control the expression of the master gene brlA, and thus, loss-of-function mutations in flb (upstream developmental activation [UDA]) genes block brlA transcription and, consequently, the production of conidiophores, the structures bearing asexual spores known as conidia. However, the aconidial phenotype of specific flb mutants, such as that of the ΔflbB strain, is reverted under salt-stress conditions. Previously, we generated a collection of second-site mutants of ΔflbB unable to conidiate on culture medium supplemented with NaH2PO4 (0.65 M). Here, we identified a Gly347Stop mutation within flpA as responsible for the FLIP57 phenotype and characterized the role of the putative cyclin FlpA and the remaining putative components of the C-terminal domain kinase-1 (CTDK-1) complex in A. nidulans and Aspergillus fumigatus. FlpA, Stk47, and FlpB are necessary (i) for timely germination, (ii) in the transition from metulae to phialides (the cells generating conidia) during conidiophore development, and (iii) for the development of sexual structures (cleistothecia) in A. nidulans. The three proteins are nuclear, and the nucleoplasmic localization of Stk47 depends on the activity of FlpA, which correlates with the retention of Stk47 by FlpA in pull-down assays. Overall, this work links the putative CTDK-1 complex of aspergilli with growth and developmental control. Identification of a mutation in flpA as inhibitor of conidiation in A. nidulans and functional characterization of FlpA, Stk47 and FlpB as putative members of the C-terminal domain kinase complex CTDK-1 in A. nidulans and A. fumigatus.IMPORTANCEAspergillus fumigatus has been included by the World Health Organization in the priority list of fungal pathogens because (i) it causes 90% of invasive aspergillosis cases, with a high mortality rate, and (ii) infections are becoming increasingly resistant to azole antifungals. A. nidulans is an opportunistic pathogen and a saprotroph which has served during the last 80 years as a reference system for filamentous fungi. Here, we characterized the role in morphogenesis and development of the putative transcriptional cyclin/kinase complex CTDK-1 in both aspergilli. The null mutants of the corresponding genes showed delayed germination, aberrant conidiophore development, and inhibition of cleistothecia production. While in higher eukaryotes this complex is formed only by a cyclin and a kinase, the fungal complex would incorporate a fungal-specific third component, FlpB, which would enable the interaction between the kinase (Stk47) and the cyclin (FlpA) and may be used as a target for antifungals.
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Affiliation(s)
- Z. Agirrezabala
- Laboratory of Biology, Department of Applied Chemistry, Faculty of Chemistry, University of the Basque Country, UPV/EHU, San Sebastian, Spain
| | - X. Guruceaga
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - A. Martin-Vicente
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - A. Otamendi
- Laboratory of Biology, Department of Applied Chemistry, Faculty of Chemistry, University of the Basque Country, UPV/EHU, San Sebastian, Spain
| | - A. Fagoaga
- Laboratory of Biology, Department of Applied Chemistry, Faculty of Chemistry, University of the Basque Country, UPV/EHU, San Sebastian, Spain
| | - J. R. Fortwendel
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - E. A. Espeso
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas (CSIC), Madrid, Spain
| | - O. Etxebeste
- Laboratory of Biology, Department of Applied Chemistry, Faculty of Chemistry, University of the Basque Country, UPV/EHU, San Sebastian, Spain
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Le Gratiet KL, Anderson CK, Puente N, Grandes P, Copas C, Nahirney PC, Delaney KR, Nashmi R. Differential Subcellular Distribution and Release Dynamics of Cotransmitted Cholinergic and GABAergic Synaptic Inputs Modify Dopaminergic Neuronal Excitability. J Neurosci 2022; 42:8670-8693. [PMID: 36195440 PMCID: PMC9671585 DOI: 10.1523/jneurosci.2514-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 08/31/2022] [Accepted: 09/02/2022] [Indexed: 11/21/2022] Open
Abstract
We identified three types of monosynaptic cholinergic inputs spatially arranged onto medial substantia nigra dopaminergic neurons in male and female mice: cotransmitted acetylcholine (ACh)/GABA, GABA-only, and ACh only. There was a predominant GABA-only conductance along lateral dendrites and soma-centered ACh/GABA cotransmission. In response to repeated stimulation, the GABA conductance found on lateral dendrites decremented less than the proximally located GABA conductance, and was more effective at inhibiting action potentials. While soma-localized ACh/GABA cotransmission showed depression of the GABA component with repeated stimulation, ACh-mediated nicotinic responses were largely maintained. We investigated whether this differential change in inhibitory/excitatory inputs leads to altered neuronal excitability. We found that a depolarizing current or glutamate preceded by cotransmitted ACh/GABA was more effective in eliciting an action potential compared with current, glutamate, or ACh/GABA alone. This enhanced excitability was abolished with nicotinic receptor inhibitors, and modulated by T- and L-type calcium channels, thus establishing that activity of multiple classes of ion channels integrates to shape neuronal excitability.SIGNIFICANCE STATEMENT Our laboratory has previously discovered a population of substantia nigra dopaminegic neurons (DA) that receive cotransmitted ACh and GABA. This study used subcellular optogenetic stimulation of cholinergic presynaptic terminals to map the functional ACh and GABA synaptic inputs across the somatodendritic extent of substantia nigra DA neurons. We determined spatially clustered GABA-only inputs on the lateral dendrites while cotransmitted ACh and GABA clustered close to the soma. We have shown that the action of GABA and ACh in cotransmission spatially clustered near the soma play a critical role in enhancing glutamate-mediated neuronal excitability through the activation of T- and L-type voltage-gated calcium channels.
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Affiliation(s)
| | | | - Nagore Puente
- Department of Neurosciences, Faculty of Medicine and Nursing, University of the Basque Country Universidad del Pais Vasco / Euskal Herriko Unibertsitatea, Leioa, Spain
- Achucarro Basque Center for Neuroscience, Science Park of the UPV/EHU, E-48940, Leioa, Spain
| | - Pedro Grandes
- Department of Neurosciences, Faculty of Medicine and Nursing, University of the Basque Country Universidad del Pais Vasco / Euskal Herriko Unibertsitatea, Leioa, Spain
- Achucarro Basque Center for Neuroscience, Science Park of the UPV/EHU, E-48940, Leioa, Spain
| | - Charlotte Copas
- Division of Medical Sciences
- Centre for Biomedical Research, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Patrick C Nahirney
- Division of Medical Sciences
- Centre for Biomedical Research, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Kerry R Delaney
- Department of Biology
- Centre for Biomedical Research, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Raad Nashmi
- Department of Biology
- Division of Medical Sciences
- Centre for Biomedical Research, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
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Linhardt D, Pawloff M, Woletz M, Hummer A, Tik M, Vasileiadi M, Ritter M, Lerma-Usabiaga G, Schmidt-Erfurth U, Windischberger C. Intrasession and Intersession Reproducibility of Artificial Scotoma pRF Mapping Results at Ultra-High Fields. eNeuro 2022; 9:ENEURO.0087-22.2022. [PMID: 36635900 PMCID: PMC9512620 DOI: 10.1523/eneuro.0087-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 06/29/2022] [Accepted: 08/23/2022] [Indexed: 02/02/2023] Open
Abstract
Functional magnetic resonance imaging (fMRI) combined with population receptive field (pRF) mapping allows for associating positions on the visual cortex to areas on the visual field. Apart from applications in healthy subjects, this method can also be used to examine dysfunctions in patients suffering from partial visual field losses. While such objective measurement of visual deficits (scotoma) is of great importance for, e.g., longitudinal studies addressing treatment effects, it requires a thorough assessment of accuracy and reproducibility of the results obtained. In this study, we quantified the reproducibility of pRF mapping results within and across sessions in case of central visual field loss in a group of 15 human subjects. We simulated scotoma by masking a central area of 2° radius from stimulation to establish ground-truth conditions. This study was performed on a 7T ultra-high field MRI scanner for increased sensitivity. We found excellent intrasession and intersession reproducibility for the pRF center position (Spearman correlation coefficients for x, y: >0.95; eccentricity: >0.87; polar angle: >0.98), but only modest reproducibility for pRF size (Spearman correlation coefficients around 0.4). We further examined the scotoma detection performance using an automated method based on a reference dataset acquired with full-field stimulation. For the 2° artificial scotoma, the group-averaged scotoma sizes were estimated at between 1.92° and 2.19° for different sessions. We conclude that pRF mapping of visual field losses yields robust, reproducible measures of retinal function and suggest the use of pRF mapping as an objective method for monitoring visual deficits during therapeutic interventions or disease progression.
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Affiliation(s)
- David Linhardt
- High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, 1090 Vienna, Austria
| | - Maximilian Pawloff
- Department of Ophthalmology, Medical University of Vienna, 1090 Vienna, Austria
| | - Michael Woletz
- High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, 1090 Vienna, Austria
| | - Allan Hummer
- High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, 1090 Vienna, Austria
| | - Martin Tik
- High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, 1090 Vienna, Austria
| | - Maria Vasileiadi
- High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, 1090 Vienna, Austria
| | - Markus Ritter
- Department of Ophthalmology, Medical University of Vienna, 1090 Vienna, Austria
| | - Garikoitz Lerma-Usabiaga
- BCBL, Basque Center on Cognition, Brain and Language, 20009 Donostia-San Sebastián, Gipuzkoa, Spain
| | | | - Christian Windischberger
- High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, 1090 Vienna, Austria
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