scholarly journals A novel live-cell imaging system reveals a reversible hydrostatic pressure impact on cell-cycle progression

2018 ◽  
Vol 131 (15) ◽  
pp. jcs212167 ◽  
Author(s):  
Holly R. Brooker ◽  
Irene A. Gyamfi ◽  
Agnieszka Wieckowska ◽  
Nicholas J. Brooks ◽  
Daniel P. Mulvihill ◽  
...  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sadaf Kalsum ◽  
Blanka Andersson ◽  
Jyotirmoy Das ◽  
Thomas Schön ◽  
Maria Lerm

Abstract Background Efficient high-throughput drug screening assays are necessary to enable the discovery of new anti-mycobacterial drugs. The purpose of our work was to develop and validate an assay based on live-cell imaging which can monitor the growth of two distinct phenotypes of Mycobacterium tuberculosis and to test their susceptibility to commonly used TB drugs. Results Both planktonic and cording phenotypes were successfully monitored as fluorescent objects using the live-cell imaging system IncuCyte S3, allowing collection of data describing distinct characteristics of aggregate size and growth. The quantification of changes in total area of aggregates was used to define IC50 and MIC values of selected TB drugs which revealed that the cording phenotype grew more rapidly and displayed a higher susceptibility to rifampicin. In checkerboard approach, testing pair-wise combinations of sub-inhibitory concentrations of drugs, rifampicin, linezolid and pretomanid demonstrated superior growth inhibition of cording phenotype. Conclusions Our results emphasize the efficiency of using automated live-cell imaging and its potential in high-throughput whole-cell screening to evaluate existing and search for novel antimycobacterial drugs.


2016 ◽  
Vol 124 (6) ◽  
pp. 1780-1787 ◽  
Author(s):  
Zhenjun Zhao ◽  
Michael S. Johnson ◽  
Biyi Chen ◽  
Michael Grace ◽  
Jaysree Ukath ◽  
...  

OBJECT Stereotactic radiosurgery (SRS) is an established intervention for brain arteriovenous malformations (AVMs). The processes of AVM vessel occlusion after SRS are poorly understood. To improve SRS efficacy, it is important to understand the cellular response of blood vessels to radiation. The molecular changes on the surface of AVM endothelial cells after irradiation may also be used for vascular targeting. This study investigates radiation-induced externalization of phosphatidylserine (PS) on endothelial cells using live-cell imaging. METHODS An immortalized cell line generated from mouse brain endothelium, bEnd.3 cells, was cultured and irradiated at different radiation doses using a linear accelerator. PS externalization in the cells was subsequently visualized using polarity-sensitive indicator of viability and apoptosis (pSIVA)-IANBD, a polarity-sensitive probe. Live-cell imaging was used to monitor PS externalization in real time. The effects of radiation on the cell cycle of bEnd.3 cells were also examined by flow cytometry. RESULTS Ionizing radiation effects are dose dependent. Reduction in the cell proliferation rate was observed after exposure to 5 Gy radiation, whereas higher radiation doses (15 Gy and 25 Gy) totally inhibited proliferation. In comparison with cells treated with sham radiation, the irradiated cells showed distinct pseudopodial elongation with little or no spreading of the cell body. The percentages of pSIVA-positive cells were significantly higher (p = 0.04) 24 hours after treatment in the cultures that received 25- and 15-Gy doses of radiation. This effect was sustained until the end of the experiment (3 days). Radiation at 5 Gy did not induce significant PS externalization compared with the sham-radiation controls at any time points (p > 0.15). Flow cytometric analysis data indicate that irradiation induced growth arrest of bEnd.3 cells, with cells accumulating in the G2 phase of the cell cycle. CONCLUSIONS Ionizing radiation causes remarkable cellular changes in endothelial cells. Significant PS externalization is induced by radiation at doses of 15 Gy or higher, concomitant with a block in the cell cycle. Radiation-induced markers/targets may have high discriminating power to be harnessed in vascular targeting for AVM treatment.


2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Yuki Takamatsu ◽  
Olga Dolnik ◽  
Takeshi Noda ◽  
Stephan Becker

Abstract Background Live-cell imaging is a powerful tool for visualization of the spatio-temporal dynamics of moving signals in living cells. Although this technique can be utilized to visualize nucleocapsid transport in Marburg virus (MARV)- or Ebola virus-infected cells, the experiments require biosafety level-4 (BSL-4) laboratories, which are restricted to trained and authorized individuals. Methods To overcome this limitation, we developed a live-cell imaging system to visualize MARV nucleocapsid-like structures using fluorescence-conjugated viral proteins, which can be conducted outside BSL-4 laboratories. Results Our experiments revealed that nucleocapsid-like structures have similar transport characteristics to those of nucleocapsids observed in MARV-infected cells, both of which are mediated by actin polymerization. Conclusions We developed a non-infectious live cell imaging system to visualize intracellular transport of MARV nucleocapsid-like structures. This system provides a safe platform to evaluate antiviral drugs that inhibit MARV nucleocapsid transport.


2016 ◽  
Vol 50 (11) ◽  
pp. 1214-1225 ◽  
Author(s):  
Saki Nakamura ◽  
Ayumi Nakanishi ◽  
Minami Takazawa ◽  
Shunsuke Okihiro ◽  
Shiro Urano ◽  
...  

2011 ◽  
Vol 44 (5) ◽  
pp. 819-827 ◽  
Author(s):  
Franck Gallardo ◽  
Nancy Laterreur ◽  
Emilio Cusanelli ◽  
Faissal Ouenzar ◽  
Emmanuelle Querido ◽  
...  

2020 ◽  
Author(s):  
Tien Minh Le ◽  
Naoki Morimoto ◽  
Nhung Thi My Ly ◽  
Toshihito Mitsui ◽  
Sharon Claudia Notodihardjo ◽  
...  

Abstract Background: Apoptosis was reported to take crucial role in mesenchymal stem cell (MSC)-mediated immunomodulation, in which apoptotic MSCs were shown to be superior compared to living MSCs. Furthermore, extracellular vesicles (Evs) derived from MSCs were revealed more specific advantages for patient safety such as lower propensity to trigger innate and adaptive immune responses. As a safety and simple operation, high hydrostatic pressure (HHP), a physical technique that uses only fluid pressure to inactivate cells or tissues, has been developed and applied in a lot of field of biosciences, including biotechnology, biomaterials, or tissue engineering. Methods: MSCs isolated from human bone marrow were suspended cultured in appropriate medium and subjected to pressurization at 50 MPa for 36 h. Then cells were collected and investigated apoptotic pathway by transmission electron microscopy (TEM), phosphatidylserine membrane translocations, cleaved caspase-3/7 and terminal deoxy-nucleotidyl transferase dUTP nick-end labeling (TUNEL) staining. Besides, viability assays and live cell imaging were also used for assessement of cell survival after pressurization. Results: We found that HHP at 50 MPa for ≥36 h completely induced MSC death by Live/Dead assay, live cell imaging and WST-8 assay up to 7 days after pressurization. The large amount of apoptotic MSCs death was found based on morphological changes in TEM, phosphatidylserine exposure, caspase activation and detection of DNA fragmentations via TUNEL staining. Conclusions: In the current study, our data revealed that HHP treatment was convenient processing which safety and effectively induced MSCs undergo apoptosis. Especially, by capable of manufacture expanding, this technique might provide numbers of manipulated products using for industrial cell-based therapies.


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