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Matsumoto A, Terashima I, Uesono Y. A rapid and simple spectroscopic method for the determination of yeast cell viability using methylene blue. Yeast 2022; 39:607-616. [PMID: 36305512 DOI: 10.1002/yea.3819] [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: 07/14/2022] [Revised: 10/24/2022] [Accepted: 10/26/2022] [Indexed: 01/28/2023] Open
Abstract
Determination of cell viability is important in various microbiological studies. The microscopic method, counting dead cells stained by methylene blue (MB), has often been used for the determination of viability, although it is not efficient for the measurement of a large number of samples. Alternatively, some spectroscopic methods have been proposed to avoid tedious cell counting. One of these proposed methods detects the decrease in MB absorbance in the supernatant of cell suspension, because dead cells incorporate MB more efficiently than viable cells. However, at present, this spectroscopic method is rarely used due to its low throughput. Therefore, we devised a small-scale, rapid and simple method by improving several points as follows. (1) The peak wavelength of MB absorbance, 665 nm, was used to detect MB efficiently at the microtube scale. (2) The composition of the MB solution was improved by adding trisodium citrate. (3) The reaction time was shortened. And (4) the concentration ranges of both MB and cells, with which absorbance is linearly related to cell viability, were determined. The improved method enabled us to evaluate the dose-dependent toxicities of alcohols, antifungal/antimalarial quinacrine, and UV-C irradiation. The results were compatible with those of conventional microscopic counting and colony formation. The method would be applicable to automated determination and to various organisms such as bacteria and filamentous fungi which are difficult to be counted microscopically.
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Affiliation(s)
- Atsushi Matsumoto
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Ichiro Terashima
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Yukifumi Uesono
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
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Matsumoto A, Adachi H, Terashima I, Uesono Y. Escaping from the Cutoff Paradox by Accumulating Long-Chain Alcohols in the Cell Membrane. J Med Chem 2022; 65:10471-10480. [PMID: 35857416 DOI: 10.1021/acs.jmedchem.2c00629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The mechanism for the cutoff, an activity cliff at which long-chain alcohols lose their biological effects, has not been elucidated. Highly hydrophobic oleyl alcohol (C18:1) exists as a mixture of monomers and aggregated droplets in water. C18:1 did not inhibit the yeast growth but inhibited the growth of the slime mold without a cell wall. C18:1 exhibited toxicity to the yeast protoplast, which was enhanced by polyethylene glycol, a fusogen. Therefore, direct interactions of C18:1 with the membrane are crucial for the toxicity. The cutoff alcohols, C14 and C16, also exhibited strong toxicity obeying the Meyer-Overton correlation, in intact yeast cells whose membrane growth was suppressed in water. Taken together, the cutoff is avoidable by securing sufficient accumulation of the wall-permeable monomers in the membrane, which supports the lipid theory. It would be important to distinguish the effective drug structure localizing in the membrane and deal with the amount in the membrane.
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Affiliation(s)
- Atsushi Matsumoto
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.,Department of Biology, Faculty of Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Hiroyuki Adachi
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.,Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Ichiro Terashima
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yukifumi Uesono
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Kiik H, Ramanayake S, Miura M, Tanaka Y, Melamed A, Bangham CRM. Time-course of host cell transcription during the HTLV-1 transcriptional burst. PLoS Pathog 2022; 18:e1010387. [PMID: 35576236 PMCID: PMC9135347 DOI: 10.1371/journal.ppat.1010387] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/26/2022] [Accepted: 04/22/2022] [Indexed: 12/30/2022] Open
Abstract
The human T-cell leukemia virus type 1 (HTLV-1) transactivator protein Tax has pleiotropic functions in the host cell affecting cell-cycle regulation, DNA damage response pathways and apoptosis. These actions of Tax have been implicated in the persistence and pathogenesis of HTLV-1-infected cells. It is now known that tax expression occurs in transcriptional bursts of the proviral plus-strand, but the effects of the burst on host transcription are not fully understood. We carried out RNA sequencing of two naturally-infected T-cell clones transduced with a Tax-responsive Timer protein, which undergoes a time-dependent shift in fluorescence emission, to study transcriptional changes during successive phases of the HTLV-1 plus-strand burst. We found that the transcriptional regulation of genes involved in the NF-κB pathway, cell-cycle regulation, DNA damage response and apoptosis inhibition were immediate effects accompanying the plus-strand burst, and are limited to the duration of the burst. The results distinguish between the immediate and delayed effects of HTLV-1 reactivation on host transcription, and between clone-specific effects and those observed in both clones. The major transcriptional changes in the infected host T-cells observed here, including NF-κB, are transient, suggesting that these pathways are not persistently activated at high levels in HTLV-1-infected cells. The two clones diverged strongly in their expression of genes regulating the cell cycle. Up-regulation of senescence markers was a delayed effect of the proviral plus-strand burst and the up-regulation of some pro-apoptotic genes outlasted the burst. We found that activation of the aryl hydrocarbon receptor (AhR) pathway enhanced and prolonged the proviral burst, but did not increase the rate of reactivation. Our results also suggest that sustained plus-strand expression is detrimental to the survival of infected cells.
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Affiliation(s)
- Helen Kiik
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Saumya Ramanayake
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Michi Miura
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Yuetsu Tanaka
- Department of Infectious Disease and Immunology, Okinawa-Asia Research Center of Medical Science, Faculty of Medicine, University of the Ryukyus, Nishihara, Okinawa, Japan
| | - Anat Melamed
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Charles R. M. Bangham
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom
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Kitagawa T, Matsumoto A, Terashima I, Uesono Y. Antimalarial Quinacrine and Chloroquine Lose Their Activity by Decreasing Cationic Amphiphilic Structure with a Slight Decrease in pH. J Med Chem 2021; 64:3885-3896. [PMID: 33775096 DOI: 10.1021/acs.jmedchem.0c02056] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Quinacrine (QC) and chloroquine (CQ) have antimicrobial and antiviral activities as well as antimalarial activity, although the mechanisms remain unknown. QC increased the antimicrobial activity against yeast exponentially with a pH-dependent increase in the cationic amphiphilic drug (CAD) structure. CAD-QC localized in the yeast membranes and induced glucose starvation by noncompetitively inhibiting glucose uptake as antipsychotic chlorpromazine (CPZ) did. An exponential increase in antimicrobial activity with pH-dependent CAD formation was also observed for CQ, indicating that the CAD structure is crucial for its pharmacological activity. A decrease in CAD structure with a slight decrease in pH from 7.4 greatly reduced their effects; namely, these drugs would inefficiently act on falciparum malaria and COVID-19 pneumonia patients with acidosis, resulting in resistance. The decrease in CAD structure at physiological pH was not observed for quinine, primaquine, or mefloquine. Therefore, restoring the normal blood pH or using pH-insensitive quinoline drugs might be effective for these infectious diseases with acidosis.
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Affiliation(s)
- Tomohisa Kitagawa
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Atsushi Matsumoto
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ichiro Terashima
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yukifumi Uesono
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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