Antiarrhythmic drug amiodarone displays antifungal activity, induces irregular calcium response and intracellular acidification of Aspergillus niger – Amiodarone targets calcium and pH homeostasis of A. niger

Bagar, Tanja; Benčina, Mojca

doi:10.1016/j.fgb.2012.07.007

Cited by 16 publications

(18 citation statements)

References 50 publications

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“…The ratios of two fluorescence parameters (i.e., F 405-nm and F 488-nm ) were calculated for every cell by dividing the emission signals. To correlate ratios with pH, we generated a calibration curve that links fluorescence intensity ratios to pH, as described previously (13,22), with minor modifications. The reader is referred to the in situ calibration section.…”

Section: Methodsmentioning

confidence: 99%

“…For flow cytometry, the cells were diluted in medium (2 ml) in which yeasts had been cultivated (referred to as "spent medium" hereafter); the medium was used to obtain a density suitable for analysis (400 cells s Ϫ1 at low speed). The fluorescence intensities after excitation at 405 and 476 nm (488 nm for flow cytometry) were recorded and converted to pH values using equations 1 and 2 (13,22):…”

Section: Methodsmentioning

confidence: 99%

“…For each set of experiments, calibration was performed, as described by Bagar et al (13,22), with minor modifications. The H4307 yeast strain was grown in modified synthetic complete medium (28) without methionine (SC-Met), and the H3909 yeast strain was grown in synthetic complete medium (28) without leucine and uracil (SC-Leu-Ura) with 20 g of glucose liter…”

Section: Methodsmentioning

confidence: 99%

“…Although spectroscopy rapidly records the average pH i of a population, it provides insufficient single-cell information. To obtain spatial distribution and a detailed mapping of the pH in single cells, researchers have used pHluorin in combination with fluorescence microscopy (12,13,17,18,21,22). Despite the advantages of this approach, analyzing the images of individual cells is laborious and time-consuming even with the aid of software programs (23).…”

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confidence: 99%

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Noninvasive High-Throughput Single-Cell Analysis of the Intracellular pH of Saccharomyces cerevisiae by Ratiometric Flow Cytometry

Valkonen

Mojžita

Penttilä

et al. 2013

Appl Environ Microbiol

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The ability of cells to maintain pH homeostasis in response to environmental changes has elicited interest in basic and applied research and has prompted the development of methods for intracellular pH measurements. Many traditional methods provide information at population level and thus the average values of the studied cell physiological phenomena, excluding the fact that cell cultures are very heterogeneous. Single-cell analysis, on the other hand, offers more detailed insight into population variability, thereby facilitating a considerably deeper understanding of cell physiology. Although microscopy methods can address this issue, they suffer from limitations in terms of the small number of individual cells that can be studied and complicated image processing. We developed a noninvasive high-throughput method that employs flow cytometry to analyze large populations of cells that express pHluorin, a genetically encoded ratiometric fluorescent probe that is sensitive to pH. The method described here enables measurement of the intracellular pH of single cells with high sensitivity and speed, which is a clear improvement compared to previously published methods that either require pretreatment of the cells, measure cell populations, or require complex data analysis. The ratios of fluorescence intensities, which correlate to the intracellular pH, are independent of the expression levels of the pH probe, making the use of transiently or extrachromosomally expressed probes possible. We conducted an experiment on the kinetics of the pH homeostasis of Saccharomyces cerevisiae cultures grown to a stationary phase after ethanol or glucose addition and after exposure to weak acid stress and glucose pulse. Minor populations with pH homeostasis behaving differently upon treatments were identified.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

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Noninvasive High-Throughput Single-Cell Analysis of the Intracellular pH of Saccharomyces cerevisiae by Ratiometric Flow Cytometry

Valkonen

Mojžita

Penttilä

et al. 2013

Appl Environ Microbiol

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“…Another study showed enhanced growth sensitivity of ⌬mid1 and ⌬cch1 mutants to AMD over that of the wild type, also revealing discrepancies between the effects of this drug on Mid1 and Cch1 protein functions (59). Recently, researchers also studied the influence of AMD on calcium and pH homeostasis in Aspergillus niger by using aequorin as a reporter (60). They showed that a characteristic calcium signature and elevated cytosolic calcium concentrations are accompanied by intracellular acidification after AMD treatment and that deletion of the calcium P-type ATPases, PmrA and PmcA, resulted in mutants hypersensitive to AMD.…”

Section: Discussionmentioning

confidence: 99%

Cch1 and Mid1 Are Functionally Required for Vegetative Growth under Low-Calcium Conditions in the Phytopathogenic Ascomycete Botrytis cinerea

Harren

Tudzynski

2013

Eukaryot Cell

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In the filamentous phytopathogen Botrytis cinerea, the Ca 2؉ /calcineurin signaling cascade has been shown to play an important role in fungal growth, differentiation, and virulence. This study deals with the functional characterization of two components of this pathway, the putative calcium channel proteins Cch1 and Mid1. The cch1 and mid1 genes were deleted, and single and double knockout mutants were analyzed during different stages of the fungal life cycle. Our data indicate that Cch1 and Mid1 are functionally required for vegetative growth under conditions of low extracellular calcium, since the growth of both deletion mutants is strongly impaired when they are exposed to the Ca 2؉ -chelating agents EGTA and 1,2-bis(o-aminophenoxy)ethane-N,N,N=,N=-tetraacetic acid (BAPTA). The impact of external Ca 2؉ was investigated by supplementing with CaCl 2 and the ionophore A23187, both of which resulted in elevated growth for all mutants. However, deletion of either gene had no impact on germination, sporulation, hyphal morphology, or virulence. By use of the aequorin reporter system to measure intracellular calcium levels, no differences between the mutant strains and the wild type were obtained. Localization studies revealed a subcellular distribution of the Mid1-green fluorescent protein (GFP) fusion protein in network-like filaments, probably the endoplasmic reticulum (ER) membranes, indicating that Mid1 is not a plasma membrane-located calcium channel in B. cinerea.

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Drug repurposing strategies in the development of potential antifungal agents

Zhang

Liu

Zeng

et al. 2021

Appl Microbiol Biotechnol

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The morbidity and mortality caused by invasive fungal infections are increasing across the globe due to developments in transplant surgery, the use of immunosuppressive agents, and the emergence of drug-resistant fungal strains, which has led to a challenge in terms of treatment due to the limitations of three classes of drugs. Hence, it is imperative to establish effective strategies to identify and design new antifungal drugs. Drug repurposing is a potential way of expanding the application of existing drugs. Recently, various existing drugs have been shown to be useful in the prevention and treatment of invasive fungi. In this review, we summarize the currently used antifungal agents. In addition, the most up-to-date information on the effectiveness of existing drugs with antifungal activity is discussed. Moreover, the antifungal mechanisms of existing drugs are highlighted. These data will provide valuable knowledge to stimulate further investigation and clinical application in this field. Key points • Conventional antifungal agents have limitations due to the occurrence of drug-resistant strains. • Non-antifungal drugs act as antifungal agents in various ways toward different targets. • Non-antifungal drugs with antifungal activity are demonstrated as effective antifungal strategies.

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Antiarrhythmic drug amiodarone displays antifungal activity, induces irregular calcium response and intracellular acidification of Aspergillus niger – Amiodarone targets calcium and pH homeostasis of A. niger

Cited by 16 publications

References 50 publications

Noninvasive High-Throughput Single-Cell Analysis of the Intracellular pH of Saccharomyces cerevisiae by Ratiometric Flow Cytometry

Noninvasive High-Throughput Single-Cell Analysis of the Intracellular pH of Saccharomyces cerevisiae by Ratiometric Flow Cytometry

Cch1 and Mid1 Are Functionally Required for Vegetative Growth under Low-Calcium Conditions in the Phytopathogenic Ascomycete Botrytis cinerea

Drug repurposing strategies in the development of potential antifungal agents

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