Ratiometric Fluorescent Silicon Quantum Dots–Ce6 Complex Probe for the Live Cell Imaging of Highly Reactive Oxygen Species

2017 ◽  
Vol 9 (3) ◽  
pp. 2052-2058 ◽  
Author(s):  
Qianqian Zhao ◽  
Ren Zhang ◽  
Daixin Ye ◽  
Song Zhang ◽  
Hui Chen ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Quantum Dots ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Reactive Oxygen ◽  
Live Cell ◽  
Oxygen Species ◽  
Silicon Quantum Dots

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 Glycerol–water mediated centrifuge controlled green synthesis of oleic acid capped PbS quantum dots for live cell imaging

RSC Advances ◽  
2017 ◽  
Vol 7 (64) ◽  
pp. 40664-40668 ◽  
Author(s):  
M. Vijaya Bharathi ◽  
Kaustab Ghosh ◽  
Priyankar Paira
Keyword(s):  
Quantum Dots ◽  
Oleic Acid ◽  
Green Synthesis ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Live Cell ◽  
Glycerol Water ◽  
Pbs Quantum Dots

Glycerol–water mediated green synthesis of PbS quantum dots (QDs) is introduced utilizing distinctive precipitation strategies for bioimaging application.

scholarly journals Live Cell Imaging: 3-Dimensional Tracking of Non-blinking ‘Giant’ Quantum Dots in Live Cells (Adv. Funct. Mater. 30/2014)

2014 ◽  
Vol 24 (30) ◽  
pp. 4795-4795 ◽  
Author(s):  
Aaron M. Keller ◽  
Yagnaseni Ghosh ◽  
Matthew S. DeVore ◽  
Mary E. Phipps ◽  
Michael H. Stewart ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Live Cell ◽  
Live Cells ◽  
3 Dimensional

THE ROLES OF PHOTOLUMINESCENT QUANTUM DOTS IN GENERATION OR DETECTION OF REACTIVE OXYGEN SPECIES: CULPRITS OR DETECTIVES?

COSMOS ◽  
2010 ◽  
Vol 06 (02) ◽  
pp. 149-158
Author(s):  
SUHUA WANG ◽  
DEJIAN HUANG
Keyword(s):  
Reactive Oxygen Species ◽  
Quantum Dots ◽  
Organic Dyes ◽  
Resonance Energy Transfer ◽  
Reactive Oxygen ◽  
Resonance Energy ◽  
Oxygen Species ◽  
Positive Side ◽  
Biological Importance ◽  
Organic Sensitizers

In this review, we systematically analyzed the complicated interrelationship between photoluminescent quantum dots (QDs) and reactive oxygen species of biological importance. QDs, when photoexcited, generate reactive oxygen species (ROS), which are partially blamed for the cytotoxicity of QDs. On the positive side, the ability of generating ROS by QDs are exploited in photodynamic therapy using QDs alone or in combination with QD-surface bound organic sensitizers via resonance energy transfer from QDs to the organic dyes. Lastly, depending on the chemical composition and the functionalization of the QDs, ROS are known to quench or switch-on the QD photoluminescence. The selectivity and sensitivity toward specific ROS can be achieved through judicious chemical modification of QD surface coating layers by taking into account the reactivity difference among different ROS. The flexible QD surface functionalization opens up the unprecedented possibility of designer-made nanoprobes for sensing and quantifying ROS of biological importance.

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