scholarly journals Multimodal Label-Free Imaging to Assess Compositional and Morphological Changes in Cells During Immune Activation

2019 ◽  
pp. 141-146
Author(s):  
Nicholas Isaac Smith
Keyword(s):  
Immune Activation ◽  
Morphological Changes ◽  
Label Free ◽  
In Cells

scholarly journals Methods and applications of label-free cell-based systems

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Joachim Wiest
Keyword(s):  
Environmental Monitoring ◽  
Morphological Changes ◽  
Free Cell ◽  
Living Cells ◽  
Label Free ◽  
Controlled System ◽  
Chip Technology ◽  
Cell Monitoring ◽  
A Cell ◽  
On Chip

Label-free monitoring of living cells is used in various applications such as drug development, toxicology, regenerative medicine or environmental monitoring. The most prominent methods for monitoring the extracellular acidification, oxygen consumption, electrophysiological activity and morphological changes of living cells are described. Furthermore, the intelligent mobile lab (IMOLA) – a computer controlled system integrating cell monitoring and automated cell cultivation – is described as an example of a cell-based system for microphysiometry. Results from experiments in the field of environmental monitoring using algae are presented. An outlook toward the development of an organ-on-chip technology is given.

scholarly journals Systematic Enzyme Mapping of Cellular Metabolism by Phasor-Analyzed Label-Free NAD(P)H Fluorescence Lifetime Imaging

2019 ◽  
Vol 20 (22) ◽  
pp. 5565 ◽  
Author(s):  
Leben ◽  
Köhler ◽  
Radbruch ◽  
Hauser ◽  
Niesner
Keyword(s):  
Fluorescence Lifetime ◽  
Metabolic Activity ◽  
Cellular Metabolism ◽  
Fluorescence Lifetime Imaging ◽  
Label Free ◽  
Analysis Framework ◽  
Cell Nuclei ◽  
Lifetime Imaging ◽  
Subcellular Resolution ◽  
In Cells

In the past years, cellular metabolism of the immune system experienced a revival, as it has become clear that it is not merely responsible for the cellular energy supply, but also impacts on many signaling pathways and, thus, on diverse cellular functions. Label-free fluorescence lifetime imaging of the ubiquitous coenzymes NADH and NADPH (NAD(P)H-FLIM) makes it possible to monitor cellular metabolism in living cells and tissues and has already been applied to study metabolic changes both under physiologic and pathologic conditions. However, due to the complex distribution of NAD(P)H-dependent enzymes in cells, whose distribution continuously changes over time, a thorough interpretation of NAD(P)H-FLIM results, in particular, resolving the contribution of various enzymes to the overall metabolic activity, remains challenging. We developed a systematic framework based on angle similarities of the phase vectors and their length to analyze NAD(P)H-FLIM data of cells and tissues based on a generally valid reference system of highly abundant NAD(P)H-dependent enzymes in cells. By using our analysis framework, we retrieve information not only about the overall metabolic activity, i.e., the fraction of free to enzyme-bound NAD(P)H, but also identified the enzymes predominantly active within the sample at a certain time point with subcellular resolution. We verified the performance of the approach by applying NAD(P)H-FLIM on a stromal-like cell line and identified a different group of enzymes that were active in the cell nuclei as compared to the cytoplasm. As the systematic phasor-based analysis framework of label-free NAD(P)H-FLIM can be applied both in vitro and in vivo, it retains the unique power to enable dynamic enzyme-based metabolic investigations, at subcellular resolution, in genuine environments.

Label-free imaging of semiconducting and metallic carbon nanotubes in cells and mice using transient absorption microscopy

2011 ◽  
Vol 7 (1) ◽  
pp. 56-61 ◽  
Author(s):  
Ling Tong ◽  
Yuxiang Liu ◽  
Bridget D. Dolash ◽  
Yookyung Jung ◽  
Mikhail N. Slipchenko ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Transient Absorption ◽  
Label Free ◽  
In Cells

Label-free monitoring of apoptosis by surface plasmon resonance detection of morphological changes

APOPTOSIS ◽  
2012 ◽  
Vol 17 (8) ◽  
pp. 916-925 ◽  
Author(s):  
Jean-Sébastien Maltais ◽  
Jean-Bernard Denault ◽  
Louis Gendron ◽  
Michel Grandbois
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Morphological Changes ◽  
Label Free ◽  
Resonance Detection

scholarly journals Whole-Cell Multiparameter Assay for Ricin and Abrin Activity-Based Digital Holographic Microscopy

Toxins ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 174 ◽  
Author(s):  
Efi Makdasi ◽  
Orly Laskar ◽  
Elad Milrot ◽  
Ofir Schuster ◽  
Shlomo Shmaya ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Morphological Changes ◽  
Annexin V ◽  
Time Lapse ◽  
Digital Holographic Microscopy ◽  
Optical Parameters ◽  
Label Free ◽  
Calculated Volume ◽  
Apoptosis Assay ◽  
Holographic Microscopy

Ricin and abrin are ribosome-inactivating proteins leading to inhibition of protein synthesis and cell death. These toxins are considered some of the most potent and lethal toxins against which there is no available antidote. Digital holographic microscopy (DHM) is a time-lapse, label-free, and noninvasive imaging technique that can provide phase information on morphological features of cells. In this study, we employed DHM to evaluate the morphological changes of cell lines during ricin and abrin intoxication. We showed that the effect of these toxins is characterized by a decrease in cell confluence and changes in morphological parameters such as cell area, perimeter, irregularity, and roughness. In addition, changes in optical parameters such as phase-shift, optical thickness, and effective-calculated volume were observed. These effects were completely inhibited by specific neutralizing antibodies. An enhanced intoxication effect was observed for preadherent compared to adherent cells, as was detected in early morphology changes and confirmed by annexin V/propidium iodide (PI) apoptosis assay. Detection of the dynamic changes in cell morphology at initial stages of cell intoxication by DHM emphasizes the highly sensitive and rapid nature of this method, allowing the early detection of active toxins.

scholarly journals Quantifying the Rate, Degree, and Heterogeneity of Morphological Change during an Epithelial to Mesenchymal Transition Using Digital Holographic Cytometry

2020 ◽  
Vol 10 (14) ◽  
pp. 4726
Author(s):  
Sofia Kamlund ◽  
Birgit Janicke ◽  
Kersti Alm ◽  
Robert L. Judson-Torres ◽  
Stina Oredsson
Keyword(s):  
Cell Line ◽  
Morphological Change ◽  
Efficient Method ◽  
Mammalian Cells ◽  
Epithelial To Mesenchymal Transition ◽  
Morphological Changes ◽  
Cell Populations ◽  
Label Free ◽  
Mesenchymal Transition ◽  
Quantitative Changes

Cells in complex organisms can transition between epithelial and mesenchymal phenotypes during both normal and malignant physiological events. These two phenotypes are not binary, but rather describe a spectrum of cell states along an axis. Mammalian cells can undergo dynamic and heterogenous bidirectional interconversions along the epithelial–mesenchymal phenotypic (EMP) spectrum, and such transitions are marked by morphological change. Here, we exploit digital holographic cytometry (DHC) to develop a tractable method for monitoring the degree, kinetics, and heterogeneity of epithelial and mesenchymal phenotypes in adherent mammalian cell populations. First, we demonstrate that the epithelial and mesenchymal states of the same cell line present distinct DHC-derived morphological features. Second, we identify quantitative changes in these features that occur hours after induction of the epithelial to mesenchymal transition (EMT). We apply this approach to achieve label-free tracking of the degree and the rate of EMP transitions. We conclude that DHC is an efficient method to investigate morphological changes during transitions between epithelial and mesenchymal states.

scholarly journals Label-free photoacoustic microscopy of cytochrome c in cells

2012 ◽  
Author(s):  
Chi Zhang ◽  
Yu Zhang ◽  
Da-Kang Yao ◽  
Younan Xia ◽  
Lihong V. Wang
Keyword(s):  
Cytochrome C ◽  
Photoacoustic Microscopy ◽  
Label Free ◽  
In Cells

Catechol cytotoxicity in vitro: Induction of glioblastoma cell death by apoptosis

2010 ◽  
Vol 29 (3) ◽  
pp. 199-212 ◽  
Author(s):  
DM de Oliveira ◽  
BPS Pitanga ◽  
MS Grangeiro ◽  
RMF Lima ◽  
MFD Costa ◽  
...  
Keyword(s):  
Cell Death ◽  
Morphological Changes ◽  
Public Health Problem ◽  
Annexin V ◽  
Toxic Effects ◽  
Cytotoxic Effects ◽  
The Central Nervous System ◽  
Hematopoietic Toxicity ◽  
In Cells

The exposure to benzene is a public health problem. Although the most well-known effect of benzene is hematopoietic toxicity, there is little information about the benzene and its metabolites effects on the central nervous system (CNS). This study examined the toxic effects of 1,2-dihydroxybenzene (catechol), a benzene metabolite, to human glioblastoma GL-15 cells. GL-15 cell cultures were used as a model to provide more information about the toxic effects of aromatic compounds to the CNS. Catechol induced time- and concentration-dependent cytotoxic effects. Morphological changes, such as the retraction of the cytoplasm and chromatin clumping, were seen in cells exposed to 200 μM catechol for 48 hours. In cells exposed to 600 μM catechol for 48 hours, 78.0% of them presented condensed nuclei, and the Comet assay showed DNA damage. The percentage of cells labeled with annexin V (apoptotic cells) was greater in the group exposed to catechol (20.7%) than in control cells (0.4%). Exposure to catechol at concentrations greater than 100 μM enhanced Bax levels, and a decrease in Bcl-2 level was observed after the exposure to 600 μM catechol for 48 hours. Furthermore, catechol depleted reduced glutathione. Hence, catechol induced cell death mainly by apoptosis.

scholarly journals Local redox conditions in cells imaged via non-fluorescent transient states of NAD(P)H

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Johan Tornmalm ◽  
Elin Sandberg ◽  
Mihailo Rabasovic ◽  
Jerker Widengren
Keyword(s):  
Laser Scanning ◽  
Redox Conditions ◽  
Metabolic Imaging ◽  
Live Cells ◽  
State Transitions ◽  
Fluorescence Lifetime Imaging ◽  
Label Free ◽  
Dark State ◽  
Photon Excitation ◽  
In Cells

Abstract The autofluorescent coenzyme nicotinamide adenine dinucleotide (NADH) and its phosphorylated form (NADPH) are major determinants of cellular redox balance. Both their fluorescence intensities and lifetimes are extensively used as label-free readouts in cellular metabolic imaging studies. Here, we introduce fluorescence blinking of NAD(P)H, as an additional, orthogonal readout in such studies. Blinking of fluorophores and their underlying dark state transitions are specifically sensitive to redox conditions and oxygenation, parameters of particular relevance in cellular metabolic studies. We show that such dark state transitions in NAD(P)H can be quantified via the average fluorescence intensity recorded upon modulated one-photon excitation, so-called transient state (TRAST) monitoring. Thereby, transitions in NAD(P)H, previously only accessible from elaborate spectroscopic cuvette measurements, can be imaged at subcellular resolution in live cells. We then demonstrate that these transitions can be imaged with a standard laser-scanning confocal microscope and two-photon excitation, in parallel with regular fluorescence lifetime imaging (FLIM). TRAST imaging of NAD(P)H was found to provide additional, orthogonal information to FLIM and allows altered oxidative environments in cells treated with a mitochondrial un-coupler or cyanide to be clearly distinguished. We propose TRAST imaging as a straightforward and widely applicable modality, extending the range of information obtainable from cellular metabolic imaging of NAD(P)H fluorescence.

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