Photosensitized Damage Inflicted on Plasma Membranes of Live Cells by An Extracellular Generator of Singlet Oxygen-A Linear Dependence of A Lethal Dose on Light Intensity

2014 ◽  
Vol 90 (3) ◽  
pp. 709-715 ◽  
Author(s):  
Mirosław Zarębski ◽  
Magdalena Kordon ◽  
Jurek W. Dobrucki
Keyword(s):  
Light Intensity ◽  
Singlet Oxygen ◽  
Linear Dependence ◽  
Plasma Membranes ◽  
Lethal Dose ◽  
Live Cells

Modulation of emission and singlet oxygen photosensitisation in live cells utilising bioorthogonal phosphorogenic probes and protein tag technology

2020 ◽  
Vol 56 (45) ◽  
pp. 6074-6077 ◽  
Author(s):  
Peter Kam-Keung Leung ◽  
Kenneth Kam-Wing Lo
Keyword(s):  
Singlet Oxygen ◽  
Live Cells ◽  
Protein Tag ◽  
Single Oxygen

We developed a strategy to exploit the bioorthogonal reactivity and phosphorogenic property of iridium(iii) polypyridine nitrone complexes and SNAP-tag protein for the modulation of emission and single oxygen photosensitisation in live cells.

Hybrids of a 9-anthracenyl moiety and fluorescein as chemodosimeters for the detection of singlet oxygen in live cells

2019 ◽  
Vol 17 (46) ◽  
pp. 9883-9891 ◽  
Author(s):  
Serghei Chercheja ◽  
Steffen Daum ◽  
Hong-Gui Xu ◽  
Frank Beierlein ◽  
Andriy Mokhir
Keyword(s):  
Singlet Oxygen ◽  
Live Cells ◽  
Highly Efficient

A highly efficient fluorogenic chemodosimeter for the detection of singlet oxygen was developed.

Imaging plasma membrane phase behaviour in live cells using a thiophene-based molecular rotor

2016 ◽  
Vol 52 (90) ◽  
pp. 13269-13272 ◽  
Author(s):  
Michael R. Dent ◽  
Ismael López-Duarte ◽  
Callum J. Dickson ◽  
Phoom Chairatana ◽  
Harry L. Anderson ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Lipid Bilayers ◽  
Plasma Membranes ◽  
Live Cell ◽  
Phase Behaviour ◽  
Live Cells ◽  
Molecular Rotor ◽  
Membrane Phase ◽  
Artificial Lipid Bilayers ◽  
Cell Plasma

A thiophene-based molecular rotor was used to probe ordering and viscosity within artificial lipid bilayers and live cell plasma membranes.

Reaction of Hypochlorous Acid with Hydrogen Peroxide and tert-Butyl Hydroperoxide. 1H NMR Spectroscopy and Chemiluminescence Analyses

1996 ◽  
Vol 51 (5-6) ◽  
pp. 386-394 ◽  
Author(s):  
Jürgen Arnhold ◽  
Oleg M. Panasenko ◽  
Jürgen Schiller ◽  
Klaus Arnold ◽  
Yurij A. Vladimirov ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Light Intensity ◽  
Singlet Oxygen ◽  
Hypochlorous Acid ◽  
Red Light ◽  
Butyl Hydroperoxide ◽  
Reactant Concentration ◽  
Tert Butyl ◽  
Tert Butyl Hydroperoxide ◽  
Butyl Peroxide

Abstract In contrast to the well-known reaction of hypochlorous acid with hydrogen peroxide, no singlet oxygen is formed as the result of reaction between hypochlorous acid and tert -butyl hydroperoxide. The reaction with hydrogen peroxide yielded a quadratic dependence of light intensity on reactant concentration, a drastic enhancement of luminescence yield using D2O as solvent and only an emission of red light, that are typical characteristics of emission result­ing from two molecules of delta singlet oxygen. Other chemiluminescence properties were observed using tert-butyl hydroperoxide. There was a linear dependence of light intensity on reactant concentration using rm-butyl hydroperoxide in excess with a decline of emission at higher concentrations. 1H-NMR spectroscopic analysis revealed di-tert-butyl peroxide, tert -butanol and also tert-butyl hypochlorite, acetone and acetate as products of the reaction between hypochlorous acid and tert -butyl hydroperoxide. The formation of di-tert-butyl peroxide is only possible assuming a tert-butyloxy radical as primary intermediate product of this reaction. Our results demonstrate that alkoxy radicals derived from organic hydroperoxides can participate in lipid peroxidation induced by hypochlorous acid. On the other hand, singlet oxygen did not influence the yield of peroxidation products. Changing H2O for D2O in suspension of egg yolk phosphaditylcholine no differences in accumulation of thiobarbituric acid reactive products were observed.

scholarly journals Mitochondrial dynamics and their intracellular traffic in porcine oocytes

Zygote ◽  
2015 ◽  
Vol 24 (4) ◽  
pp. 517-528 ◽  
Author(s):  
T. Yamochi ◽  
S. Hashimoto ◽  
A. Amo ◽  
H. Goto ◽  
M. Yamanaka ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Plasma Membranes ◽  
Mitochondrial Dynamics ◽  
Germinal Vesicle ◽  
Laser Scanning Confocal Microscopy ◽  
Energy Utilization ◽  
Meiotic Maturation ◽  
Live Cells ◽  
Germinal Vesicle Breakdown ◽  
Intracellular Traffic

SummaryMeiotic maturation of oocytes requires a variety of ATP-dependent reactions, such as germinal vesicle breakdown, spindle formation, and rearrangement of plasma membrane structure, which is required for fertilization. Mitochondria are accordingly expected be localized to subcellular sites of energy utilization. Although microtubule-dependent cellular traffic for mitochondria has been studied extensively in cultured neuronal (and some other somatic) cells, the molecular mechanism of their dynamics in mammalian oocytes at different stages of maturation remains obscure. The present work describes dynamic aspects of mitochondria in porcine oocytes at the germinal vesicle stage. After incubation of oocytes with MitoTracker Orange followed by centrifugation, mitochondria-enriched ooplasm was obtained using a glass needle and transferred into a recipient oocyte. The intracellular distribution of the fluorescent mitochondria was then observed over time using a laser scanning confocal microscopy equipped with an incubator. Kinetic analysis revealed that fluorescent mitochondria moved from central to subcortical areas of oocytes and were dispersed along plasma membranes. Such movement of mitochondria was inhibited by either cytochalasin B or cytochalasin D but not by colcemid, suggesting the involvement of microfilaments. This method of visualizing mitochondrial dynamics in live cells permits study of the pathophysiology of cytoskeleton-dependent intracellular traffic of mitochondria and associated energy metabolism during meiotic maturation of oocytes.

scholarly journals AN AUTOMATIC METHOD FOR VIABILITY ASSAY OF CULTURED CELLS

1970 ◽  
Vol 18 (8) ◽  
pp. 581-589 ◽  
Author(s):  
REGINA O'BRIEN ◽  
PHYLLIS GOTTLIEB-ROSENKRANTZ
Keyword(s):  
Light Intensity ◽  
Trypan Blue ◽  
Cultured Cells ◽  
Fluorescein Diacetate ◽  
Live Cells ◽  
Cell Populations ◽  
Automatic Method ◽  
Viability Assay ◽  
Pass Through

An automatic method for viability assay of a population of cells is described. Cell populations are stained with trypan blue (for dead cells) and fluorescein diacetate (for live cells). A rapid cell spectrophotometer measures changes in light intensity which occur when individual cells pass through the photometric field. Tallies of the number of decreases (absorption and scatter by dead cells) and the number of increases (fluorescence by live cells) in light intensity are recorded and viability percentages are calculated. These automatically determined viability percentages are compared with viability percentages determined by visual counting and classifying of cells from the same populations.

scholarly journals Coexisting Domains in the Plasma Membranes of Live Cells Characterized by Spin-Label ESR Spectroscopy

2006 ◽  
Vol 90 (12) ◽  
pp. 4452-4465 ◽  
Author(s):  
Musti J. Swamy ◽  
Laura Ciani ◽  
Mingtao Ge ◽  
Andrew K. Smith ◽  
David Holowka ◽  
...  
Keyword(s):  
Spin Label ◽  
Esr Spectroscopy ◽  
Plasma Membranes ◽  
Live Cells

scholarly journals Aquaporin-4 Dynamics in Orthogonal Arrays in Live Cells Visualized by Quantum Dot Single Particle Tracking

2008 ◽  
Vol 19 (8) ◽  
pp. 3369-3378 ◽  
Author(s):  
Jonathan M. Crane ◽  
Alfred N. Van Hoek ◽  
William R. Skach ◽  
A. S. Verkman
Keyword(s):  
Plasma Membranes ◽  
Freeze Fracture ◽  
Orthogonal Arrays ◽  
Cell Types ◽  
Single Particle Tracking ◽  
Aquaporin 4 ◽  
Live Cells ◽  
Restoring Force ◽  
Orthogonal Arrays Of Particles ◽  
Freeze Fracture Electron Microscopy

Freeze-fracture electron microscopy (FFEM) indicates that aquaporin-4 (AQP4) water channels can assemble in cell plasma membranes in orthogonal arrays of particles (OAPs). We investigated the determinants and dynamics of AQP4 assembly in OAPs by tracking single AQP4 molecules labeled with quantum dots at an engineered external epitope. In several transfected cell types, including primary astrocyte cultures, the long N-terminal “M1” form of AQP4 diffused freely, with diffusion coefficient ∼5 × 10−10 cm2/s, covering ∼5 μm in 5 min. The short N-terminal “M23” form of AQP4, which by FFEM was found to form OAPs, was relatively immobile, moving only ∼0.4 μm in 5 min. Actin modulation by latrunculin or jasplakinolide did not affect AQP4-M23 diffusion, but deletion of its C-terminal postsynaptic density 95/disc-large/zona occludens (PDZ) binding domain increased its range by approximately twofold over minutes. Biophysical analysis of short-range AQP4-M23 diffusion within OAPs indicated a spring-like potential, with a restoring force of ∼6.5 pN/μm. These and additional experiments indicated that 1) AQP4-M1 and AQP4-M23 isoforms do not coassociate in OAPs; 2) OAPs can be imaged directly by total internal reflection fluorescence microscopy; and 3) OAPs are relatively fixed, noninterconvertible assemblies that do not require cytoskeletal or PDZ-mediated interactions for formation. Our measurements are the first to visualize OAPs in live cells.

scholarly journals Imaging FCS Delineates Subtle Heterogeneity in Plasma Membranes of Resting Mast Cells

2019 ◽  
Author(s):  
Nirmalya Bag ◽  
David A. Holowka ◽  
Barbara A. Baird
Keyword(s):  
Plasma Membrane ◽  
Steady State ◽  
Mast Cells ◽  
Actin Polymerization ◽  
Plasma Membranes ◽  
Correlation Spectroscopy ◽  
Live Cells ◽  
Resting Cells ◽  
Functional Protein ◽  
Diffusion Properties

ABSTRACTA myriad of transient, nanoscopic lipid- and protein-based interactions confer a steady-state organization of plasma membrane in resting cells that is poised to orchestrate assembly of key signaling components upon reception of an extracellular stimulus. Although difficult to observe directly in live cells, these subtle interactions can be discerned by their impact on the diffusion of membrane constituents. Herein, we quantified the diffusion properties of a panel of structurally distinct lipid-anchored and transmembrane (TM) probes in RBL mast cells by multiplexed Imaging Fluorescence Correlation Spectroscopy. We developed a statistical analysis of data combined from many pixels over multiple cells to characterize differences as small as 10% in diffusion coefficients, which reflect differences in underlying interactions. We found that the distinctive diffusion properties of lipid-anchored probes can be explained by their dynamic partitioning into ordered proteo-lipid nanodomains, which encompass a major fraction of the membrane and whose physical properties are influenced by actin polymerization. Effects on diffusion by functional protein modules in both lipid-anchored and TM probes reflect additional complexity in steady-state membrane organization. The contrast we observe between different probes diffusing through the same membrane milieu represent the dynamic resting steady-state, which serves as a baseline for monitoring plasma membrane remodeling that occurs upon stimulation.

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