scholarly journals Unbiased automated quantitation of ROS signals in live retinal neurons of Drosophila using Fiji/ImageJ

BioTechniques ◽  
2021 ◽  
Author(s):  
Prajakta Deshpande ◽  
Neha Gogia ◽  
Anuradha Venkatakrishnan Chimata ◽  
Amit Singh
Keyword(s):  
Signal To Noise Ratio ◽  
Tissue Imaging ◽  
Oxygen Species ◽  
Proof Of Concept ◽  
Retinal Neurons ◽  
Eye Model ◽  
Cellular Processes ◽  
Live Tissue ◽  
Model Of Alzheimer’S Disease ◽  
Quantitation Method

Numerous imaging modules are utilized to study changes that occur during cellular processes. Besides qualitative (immunohistochemical) or semiquantitative (Western blot) approaches, direct quantitation method(s) for detecting and analyzing signal intensities for disease(s) biomarkers are lacking. Thus, there is a need to develop method(s) to quantitate specific signals and eliminate noise during live tissue imaging. An increase in reactive oxygen species (ROS) such as superoxide (O2•-) radicals results in oxidative damage of biomolecules, which leads to oxidative stress. This can be detected by dihydroethidium staining in live tissue(s), which does not rely on fixation and helps prevent stress on tissues. However, the signal-to-noise ratio is reduced in live tissue staining. We employ the Drosophila eye model of Alzheimer's disease as a proof of concept to quantitate ROS in live tissue by adapting an unbiased method. The method presented here has a potential application for other live tissue fluorescent images.

scholarly journals Experimental demonstration of spectral domain computational ghost imaging

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Piotr Ryczkowski ◽  
Caroline G. Amiot ◽  
John M. Dudley ◽  
Goëry Genty
Keyword(s):  
Signal To Noise Ratio ◽  
Michelson Interferometer ◽  
Spectral Domain ◽  
Proof Of Concept ◽  
Ghost Imaging ◽  
Spectral Measurements ◽  
Spectral Filter ◽  
Wavelength Division ◽  
Spectral Encoding ◽  
Light Effects

AbstractWe demonstrate computational spectral-domain ghost imaging by encoding complementary Fourier patterns directly onto the spectrum of a superluminescent laser diode using a programmable spectral filter. Spectral encoding before the object enables uniform spectral illumination across the beam profile, removing the need for light collection optics and yielding increased signal-to-noise ratio. In addition, the use of complementary Fourier patterns allows reduction of deleterious of parasitic light effects. As a proof-of-concept, we measure the wavelength-dependent transmission of a Michelson interferometer and a wavelength-division multiplexer. Our results open new perspectives for remote broadband spectral measurements.

scholarly journals Interphotoreceptor coupling: an evolutionary perspective

2021 ◽  
Author(s):  
Lorenzo Cangiano ◽  
Sabrina Asteriti
Keyword(s):  
Visual Information ◽  
Signal To Noise Ratio ◽  
Electrical Coupling ◽  
Physiological Role ◽  
Cellular Processes ◽  
Contact Points ◽  
Highly Sensitive ◽  
The Many ◽  
The Impact

AbstractIn the vertebrate retina, signals generated by cones of different spectral preference and by highly sensitive rod photoreceptors interact at various levels to extract salient visual information. The first opportunity for such interaction is offered by electrical coupling of the photoreceptors themselves, which is mediated by gap junctions located at the contact points of specialised cellular processes: synaptic terminals, telodendria and radial fins. Here, we examine the evolutionary pressures for and against interphotoreceptor coupling, which are likely to have shaped how coupling is deployed in different species. The impact of coupling on signal to noise ratio, spatial acuity, contrast sensitivity, absolute and increment threshold, retinal signal flow and colour discrimination is discussed while emphasising available data from a variety of vertebrate models spanning from lampreys to primates. We highlight the many gaps in our knowledge, persisting discrepancies in the literature, as well as some major unanswered questions on the actual extent and physiological role of cone-cone, rod-cone and rod-rod communication. Lastly, we point toward limited but intriguing evidence suggestive of the ancestral form of coupling among ciliary photoreceptors.

scholarly journals Tunable control of antibody immobilization using electric field

2015 ◽  
Vol 112 (7) ◽  
pp. 1995-1999 ◽  
Author(s):  
Sam Emaminejad ◽  
Mehdi Javanmard ◽  
Chaitanya Gupta ◽  
Shuai Chang ◽  
Ronald W. Davis ◽  
...  
Keyword(s):  
Solid State ◽  
Electric Field ◽  
Signal To Noise Ratio ◽  
Physical Adsorption ◽  
Antibody Immobilization ◽  
Proof Of Concept ◽  
Force Microscopy ◽  
Atomic Force ◽  
Sensing Platforms ◽  
Glass Surfaces

The controlled immobilization of proteins on solid-state surfaces can play an important role in enhancing the sensitivity of both affinity-based biosensors and probe-free sensing platforms. Typical methods of controlling the orientation of probe proteins on a sensor surface involve surface chemistry-based techniques. Here, we present a method of tunably controlling the immobilization of proteins on a solid-state surface using electric field. We study the ability to orient molecules by immobilizing IgG molecules in microchannels while applying lateral fields. We use atomic force microscopy to both qualitatively and quantitatively study the orientation of antibodies on glass surfaces. We apply this ability for controlled orientation to enhance the performance of affinity-based assays. As a proof of concept, we use fluorescence detection to indirectly verify the modulation of the orientation of proteins bound to the surface. We studied the interaction of fluorescently tagged anti-IgG with surface immobilized IgG controlled by electric field. Our study demonstrates that the use of electric field can result in more than 100% enhancement in signal-to-noise ratio compared with normal physical adsorption.

scholarly journals High-rate altimetry in SNR-based GNSS-R: Proof-of-concept of a synthetic vertical array

2021 ◽  
Author(s):  
Mauricio Kenji Yamawaki ◽  
Felipe Geremia-Nievinski ◽  
João Francisco Monico
Keyword(s):  
Sea Level ◽  
Signal To Noise Ratio ◽  
Satellite System ◽  
High Rate ◽  
Proof Of Concept ◽  
Radio Waves ◽  
Vertical Array ◽  
Remote Sensing Technique ◽  
Single Antenna ◽  
Global Navigation Satellite

Global Navigation Satellite System Reflectometry (GNSS-R) has emerged as a promising remote sensing technique for coastal sea level monitoring. The GNSS-R based on signal-to-noise ratio (SNR) observations employs a single antenna and a conventional receiver. It performs best for low elevation satellites, where direct and reflected radio waves are very similar in polarization and direction of arrival. One of the disadvantages of SNR-based GNSS-R for sea level altimetry is its low temporal resolution, which is of the order of one hour for each independent satellite pass. Here we present a proof-of-concept based on a synthetic vertical array. It exploits the mechanical movement of a single antenna at high rate (about 1 Hz). SNR observations can then be fit to a known modulation, of the order of the antenna sweeping rate. We demonstrate that centimetric altimetry precision can be achieved in a 5-minute session. [©2021 IEEE]

A new water-soluble two-photon fluorescent probe for detection of trace benzoyl peroxide in wheat flour and in living cell and tissue imaging

2019 ◽  
Vol 43 (7) ◽  
pp. 3169-3173 ◽  
Author(s):  
Haiyuan Ding ◽  
Gangqiang Yuan ◽  
Liyi Zhou
Keyword(s):  
Reactive Oxygen Species ◽  
Human Health ◽  
Fluorescent Probe ◽  
Benzoyl Peroxide ◽  
Small Molecule ◽  
Living Cell ◽  
Water Soluble ◽  
Tissue Imaging ◽  
Oxygen Species ◽  
Two Photon

Benzoyl peroxide (BPO), a member of small-molecule reactive oxygen species (ROS), has attracted considerable attention because of its impact on human health and industrial importance.

A possible biochemical link between NADPH oxidase (Nox) 1 redox-signalling and ERp72

2008 ◽  
Vol 416 (1) ◽  
pp. 55-63 ◽  
Author(s):  
Wei Chen ◽  
Wei Hao Shang ◽  
Yoshifumi Adachi ◽  
Kunitaka Hirose ◽  
David M. Ferrari ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Glutathione Transferase ◽  
Mutational Analysis ◽  
Reductase Activity ◽  
Signalling Pathways ◽  
Oxygen Species ◽  
Cellular Processes ◽  
Nadph Oxidase 1 ◽  
Endoplasmic Reticulum Protein ◽  
Cellular Context

Emerging evidence indicates that Nox (NADPH oxidase) 1-generated ROS (reactive oxygen species) play critical regulatory roles in various cellular processes, yet little is known of direct targets for the oxidase. In the present study we show that one of the proteins selectively oxidized in response to Nox1-generated ROS was ERp72 (endoplasmic reticulum protein 72 kDa) with TRX (thioredoxin) homology domains. Oxidation of ERp72 by Nox1 resulted in an inhibition of its reductase activity. EGF treatment of cells stimulated the Nox1 activity and the activated Nox1 subsequently mediated EGF-induced suppression of the ERp72 reductase activity. Co-immunoprecipitation, GST (glutathione transferase) pulldown assays and mutational analysis, indicated that Nox1 associates with ERp72, which involves its N-terminus encompassing a Ca2+-binding site and the first TRX-like motif. Furthermore, confocal microscopy showed co-localization between Nox1 and ERp72 at the plasma membrane. These results suggest that Nox1 functionally associates with ERp72, regulating redox-sensitive signalling pathways in a cellular context.

Article Commentary: Regulation of Protein Function by Residue Oxidation

2010 ◽  
Vol 3 ◽  
pp. PRI.S3327 ◽  
Author(s):  
Xing-Hai Zhang
Keyword(s):  
Protein Function ◽  
Regulatory Mechanism ◽  
Cellular Metabolism ◽  
Life Forms ◽  
Biological Macromolecules ◽  
Oxygen Species ◽  
Cellular Processes ◽  
Methionine Residues ◽  
Living Organisms ◽  
Face Generation

A majority of extant life forms require O2 to survive and thrive. Oxidation is inevitably one of the most active cellular processes and one constant challenge that living organisms must face. Generation of oxidants including reactive oxygen species is a natural consequence of cellular metabolism of all biological systems during normal life cycle under different environments. These oxidants oxidize many biological macromolecules such as proteins and affect their functions. Oxidation of specific amino acids in proteins may cause damage to protein structure and impair function, or may also activate protein activities and promote cellular metabolism. As an example, the reversible oxidation of cysteine and methionine residues has a profound impact on protein function and cellular process. A recent study that examines the effect of Met oxidation on Ser phosphorylation in a mitochondrial enzyme, pyruvate dehydrogenase, provides another demonstration that protein oxidation is an important regulatory mechanism for organisms to deal with developmental and environmental challenges throughout life processes.

scholarly journals Antioxidant and food additive BHA prevents TNF cytotoxicity by acting as a direct RIPK1 inhibitor

2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Tom Delanghe ◽  
Jon Huyghe ◽  
Seungheon Lee ◽  
Dario Priem ◽  
Samya Van Coillie ◽  
...  
Keyword(s):  
Antioxidant Properties ◽  
In Silico Analysis ◽  
Oxygen Species ◽  
Ros Scavenging ◽  
Cellular Processes ◽  
Silico Analysis ◽  
Surprising Finding ◽  
Necrosis Factor ◽  
In Cells

AbstractButylate hydroxyanisole (BHA) is a synthetic phenol that is widely utilized as a preservative by the food and cosmetic industries. The antioxidant properties of BHA are also frequently used by scientists to claim the implication of reactive oxygen species (ROS) in various cellular processes, including cell death. We report on the surprising finding that BHA functions as a direct inhibitor of RIPK1, a major signaling hub downstream of several immune receptors. Our in silico analysis predicts binding of 3-BHA, but not 2-BHA, to RIPK1 in an inactive DLG-out/Glu-out conformation, similar to the binding of the type III inhibitor Nec-1s to RIPK1. This predicted superior inhibitory capacity of 3-BHA over 2-BHA was confirmed in cells and using in vitro kinase assays. We demonstrate that the reported protective effect of BHA against tumor necrosis factor (TNF)-induced necroptotic death does not originate from ROS scavenging but instead from direct RIPK1 enzymatic inhibition, a finding that most probably extends to other reported effects of BHA. Accordingly, we show that BHA not only protects cells against RIPK1-mediated necroptosis but also against RIPK1 kinase-dependent apoptosis. We found that BHA treatment completely inhibits basal and induced RIPK1 enzymatic activity in cells, monitored at the level of TNFR1 complex I under apoptotic conditions or in the cytosol under necroptosis. Finally, we show that oral administration of BHA protects mice from RIPK1 kinase-dependent lethality caused by TNF injection, a model of systemic inflammatory response syndrome. In conclusion, our results demonstrate that BHA can no longer be used as a strict antioxidant and that new functions of RIPK1 may emerge from previously reported effects of BHA.

Sign in / Sign up

Export Citation Format

Share Document