A Dual-Emission Fluorescent Nanocomplex of Gold-Cluster-Decorated Silica Particles for Live Cell Imaging of Highly Reactive Oxygen Species

2013 ◽  
Vol 135 (31) ◽  
pp. 11595-11602 ◽  
Author(s):  
Tingting Chen ◽  
Yihui Hu ◽  
Yao Cen ◽  
Xia Chu ◽  
Yi Lu
Keyword(s):  
Reactive Oxygen Species ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Gold Cluster ◽  
Reactive Oxygen ◽  
Silica Particles ◽  
Live Cell ◽  
Oxygen Species ◽  
Dual Emission

scholarly journals Reactive oxygen species rescue lysosome coalescence during PIKfyve inhibition

2019 ◽  
Author(s):  
Golam T. Saffi ◽  
Evan Tang ◽  
Aaron Fountain ◽  
Roberto J. Botelho
Keyword(s):  
Reactive Oxygen Species ◽  
Oxidative Phosphorylation ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Phosphoinositide Kinase ◽  
Photo Damage ◽  
Endosomal Pathway ◽  
Mode Of Production

AbstractLysosomes are terminal, degradative organelles of the endosomal pathway that undergo repeated fusion-fission cycles with themselves and other organelles like endosomes, phagosomes, and autophagosomes. Lysosome number, size and degradative flux depends on the equilibrium between fusion and fission rates. Thus, conditions that favour fusion over fission will reduce lysosome numbers while enlarging remaining lysosomes. Conversely, conditions that favour fission over fusion will cause lysosome fragmentation and increase their numbers. PIKfyve is a phosphoinositide kinase that generates phosphatidylinositol-3,5-bisphosphate to modulate several lysosomal functions. PIKfyve inhibition causes a dramatic increase in lysosome size and reduction in lysosome number, consistent with lysosome coalescence. This is thought to proceed through reduced lysosome reformation and/or fission after fusion with endosomes or other lysosomes. Previously, we observed that photo-damage during live-cell imaging prevented lysosome coalescence during acute PIKfyve inhibition. Thus, we postulated that lysosome fusion and/or fission dynamics are affected by reactive oxygen species (ROS). Here, we show that ROS generated by four independent mechanisms all arrested lysosome coalescence during PIKfyve inhibition and accelerated lysosome fragmentation during PIKfyve re-activation. However, depending on the ROS species and/or mode of production, lysosome dynamics were affected distinctly. H2O2 impaired lysosome motility and reduced lysosome fusion with phagosomes, suggesting that H2O2 prevents lysosome coalescence in PIKfyve-impaired cells by reducing lysosome fusogenecity. In comparison, inhibitors of oxidative phosphorylation, glutathione, and thioredoxin that produce superoxide, did not impair lysosome motility but instead promoted clearance of actin puncta on lysosomes formed during PIKfyve inhibition. Additionally, actin depolymerizing agents prevented lysosome coalescence during PIKfyve inhibition. Thus, we discovered that ROS can generally prevent lysosome coalescence during PIKfyve inhibition using distinct mechanisms.

scholarly journals Reactive oxygen species prevent lysosome coalescence during PIKfyve inhibition

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259313
Author(s):  
Golam T. Saffi ◽  
Evan Tang ◽  
Sami Mamand ◽  
Subothan Inpanathan ◽  
Aaron Fountain ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Thiol Groups ◽  
Phosphoinositide Kinase ◽  
Photo Damage ◽  
Endosomal Pathway ◽  
Mode Of Production

Lysosomes are terminal, degradative organelles of the endosomal pathway that undergo repeated fusion-fission cycles with themselves, endosomes, phagosomes, and autophagosomes. Lysosome number and size depends on balanced fusion and fission rates. Thus, conditions that favour fusion over fission can reduce lysosome numbers while enlarging their size. Conversely, favouring fission over fusion may cause lysosome fragmentation and increase their numbers. PIKfyve is a phosphoinositide kinase that generates phosphatidylinositol-3,5-bisphosphate to modulate lysosomal functions. PIKfyve inhibition causes an increase in lysosome size and reduction in lysosome number, consistent with lysosome coalescence. This is thought to proceed through reduced lysosome reformation and/or fission after fusion with endosomes or other lysosomes. Previously, we observed that photo-damage during live-cell imaging prevented lysosome coalescence during PIKfyve inhibition. Thus, we postulated that lysosome fusion and/or fission dynamics are affected by reactive oxygen species (ROS). Here, we show that ROS generated by various independent mechanisms all impaired lysosome coalescence during PIKfyve inhibition and promoted lysosome fragmentation during PIKfyve re-activation. However, depending on the ROS species or mode of production, lysosome dynamics were affected distinctly. H2O2 impaired lysosome motility and reduced lysosome fusion with phagosomes, suggesting that H2O2 reduces lysosome fusogenecity. In comparison, inhibitors of oxidative phosphorylation, thiol groups, glutathione, or thioredoxin, did not impair lysosome motility but instead promoted clearance of actin puncta on lysosomes formed during PIKfyve inhibition. Additionally, actin depolymerizing agents prevented lysosome coalescence during PIKfyve inhibition. Thus, we discovered that ROS can generally prevent lysosome coalescence during PIKfyve inhibition using distinct mechanisms depending on the type of ROS.

scholarly journals 3D imaging of ZnO NP distribution and ROS accumulation in MCF-7 cells and quantification of retention dynamics using laser scanning confocal microscopy

2020 ◽  
Author(s):  
Aishee Dey ◽  
Gare Suman ◽  
Sarpras Swain ◽  
Proma Bhattacharya ◽  
Vaibhav Dhyani ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Live Cell Imaging ◽  
Laser Scanning ◽  
Cell Imaging ◽  
Time Lapse ◽  
Confocal Microscope ◽  
Oxygen Species ◽  
Laser Scanning Confocal Microscope ◽  
Time Lapse Microscopy ◽  
Mcf 7

Abstract Generally, investigations on nanomedicine involve conventional imaging techniques for obtaining static images on nanoparticle internalization at a single time point where various phases can be overlooked. In contrast, 3D live-cell imaging can be used for obtaining cellular retention of drugs at various phases, and cells can be followed for days. This article demonstrates the application of time-lapse microscopy in the investigation of Poly-L-lysine coated ZnO nanoparticle dynamics. In this work, a laser scanning confocal microscope has been employed to quantify the dynamics of internalization particles and reactive oxygen species generation (ROS) using volumetric imaging. Firstly, we show that simultaneous spatial mapping of nanoparticle uptake in MCF-7 cells and ROS in a single cell can be used to identify the interdependence between the accumulation of particles and ROS generation. Secondly, monitoring of ROS formation and cytotoxicity using the same imaging platform offers an advantage over monitoring these parameters using various instruments. Finally, the ability of the fluorescent particles in inducing a significant reduction in cell viability suggests its potential to be used as a therapeutic agent. The proposed framework opens up a new avenue of research for investigating mechanistic aspects of ZnO particle adsorption in vitro through long term imaging. Keywords: Fluorescent ZnO particle, Time-lapse microscopy, 3D Live-cell imaging, laser scanning confocal microscope, Reactive oxygen species

Fabrication of Nontoxic Dye-Embedded Silica Particles for Live Cell Imaging Purposes

2013 ◽  
Vol 3 (2) ◽  
pp. 132-136 ◽  
Author(s):  
Timur Sh. Atabaev ◽  
Gulnoza Urmanova ◽  
Muhammad Ajmal ◽  
Nguyen Hoa Hong
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Silica Particles ◽  
Live Cell

Fabrication of multifunctional monometallic nanohybrids for reactive oxygen species-mediated cell apoptosis and enhanced fluorescence cell imaging

2018 ◽  
Vol 6 (8) ◽  
pp. 1187-1194 ◽  
Author(s):  
Shengqiang Hu ◽  
Baoyu Ye ◽  
Hailin Tang ◽  
Fan Wu ◽  
Xinyao Yi ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Apoptosis ◽  
Cell Imaging ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Enhanced Fluorescence

Multifunctional monometallic nanohybrids were fabricated for ROS-mediated cell apoptosis and enhanced fluorescence cell imaging.

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