scholarly journals A tandem activity-based sensing and labeling strategy enables imaging of transcellular hydrogen peroxide signaling

2021 ◽  
Vol 118 (9) ◽  
pp. e2018513118
Author(s):  
Hidefumi Iwashita ◽  
Erika Castillo ◽  
Marco S. Messina ◽  
Raymond A. Swanson ◽  
Christopher J. Chang

Reactive oxygen species (ROS) like hydrogen peroxide (H2O2) are transient species that have broad actions in signaling and stress, but spatioanatomical understanding of their biology remains insufficient. Here, we report a tandem activity-based sensing and labeling strategy for H2O2 imaging that enables capture and permanent recording of localized H2O2 fluxes. Peroxy Green-1 Fluoromethyl (PG1-FM) is a diffusible small-molecule probe that senses H2O2 by a boronate oxidation reaction to trigger dual release and covalent labeling of a fluorescent product, thus preserving spatial information on local H2O2 changes. This unique reagent enables visualization of transcellular redox signaling in a microglia–neuron coculture cell model, where selective activation of microglia for ROS production increases H2O2 in nearby neurons. In addition to identifying ROS-mediated cell-to-cell communication, this work provides a starting point for the design of chemical probes that can achieve high spatial fidelity by combining activity-based sensing and labeling strategies.

2004 ◽  
Vol 96 (2) ◽  
pp. 793-801 ◽  
Author(s):  
Yong-Jin Lee ◽  
Il-Jun Kang ◽  
Rolf Bünger ◽  
Young-Hee Kang

We recently reported that pyruvate inhibited translocation and activation of p53 caused by DNA damage due to oxidant injury (Lee YJ, Kang IJ, Bünger R, and Kang YH. Microvasc Res 66: 91-101, 2003); this was associated with increased expression of apoptosis-related bcl-2 and decreased expression of bax gene. This study attempted to delineate possible regulatory sites and mechanisms of antiapoptotic pyruvate, focusing on reactive oxygen species-mediated signaling in a human umbilical vein endothelial cell model. We compared the effects of the cytosolic reductant l-lactate and malate-aspartate shuttle blocker aminooxyacetate, both of which increase cytosolic NADH, on the downstream signaling pathway. Hydrogen peroxide (0.5 mM H2O2) depleted intracellular total glutathione that was prevented by pyruvate but not by l-lactate or aminooxyacetate. Activation of caspase-3 and the cleavage of procaspase-6 and procaspase-7 were strongly inhibited by pyruvate but markedly enhanced by l-lactate and aminooxyacetate, implicating redox-related antiapoptotic mechanisms of pyruvate. Western blot analysis and immunochemical data revealed that H2O2-induced transactivation of nuclear factor-κB (NF-κB) was also inhibited by pyruvate but not by l-lactate or aminooxyacetate. In addition, H2O2 downregulated extracellular signal-regulated kinase (ERK1/2) and phosphorylated p38 mitogen-activated protein kinase (MAPK), effects that were fully reversed by pyruvate within 2 h. Collectively, these findings indicate that pyruvate can protect cellular glutathione, thus enhancing cellular antioxidant potential, and that enhanced antioxidant potential can desensitize NF-κB transactivation due to reactive oxygen species, suggesting possible metabolic redox relations to NF-κB. Furthermore, pyruvate blocked the p38 MAPK pathway and activated the ERK pathway in an apparently redox-sensitive manner, which may regulate expression of genes believed to prevent apoptosis and promote cell survival. Thus pyruvate may have therapeutic potential for reducing endothelial dysfunction and improving survival during oxidative stress.


Author(s):  
Qian Wu ◽  
Youmei Li ◽  
Ying Li ◽  
Dong Wang ◽  
Ben Zhong Tang

Hydrogen peroxide (H2O2), as one kind of key reactive oxygen species (ROS), is mainly produced endogenously primarily in the mitochondria. The selective monitoring of H2O2 in living cells is of...


Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 233
Author(s):  
Tasuku Konno ◽  
Eduardo Pinho Melo ◽  
Joseph E. Chambers ◽  
Edward Avezov

Reactive oxygen species (ROS) are produced continuously throughout the cell as products of various redox reactions. Yet these products function as important signal messengers, acting through oxidation of specific target factors. Whilst excess ROS production has the potential to induce oxidative stress, physiological roles of ROS are supported by a spatiotemporal equilibrium between ROS producers and scavengers such as antioxidative enzymes. In the endoplasmic reticulum (ER), hydrogen peroxide (H2O2), a non-radical ROS, is produced through the process of oxidative folding. Utilisation and dysregulation of H2O2, in particular that generated in the ER, affects not only cellular homeostasis but also the longevity of organisms. ROS dysregulation has been implicated in various pathologies including dementia and other neurodegenerative diseases, sanctioning a field of research that strives to better understand cell-intrinsic ROS production. Here we review the organelle-specific ROS-generating and consuming pathways, providing evidence that the ER is a major contributing source of potentially pathologic ROS.


2021 ◽  
Author(s):  
Chunning Sun ◽  
Michael Gradzielski

Hydrogen peroxide (H2O2), a key reactive oxygen species, plays an important role in living organisms, industrial and environmental fields. Here, a non-contact upconversion nanosystem based on the excitation energy attenuation...


1997 ◽  
Vol 6 (5-6) ◽  
pp. 369-374
Author(s):  
Y. Oyanagui

Anti-inflammatory actions of two anti-allergic drugs, alone or with dexamethasone (Dex) were examined in two models, because inflammation is claimed to be important for allergic events, especially for asthma. Cromoglycate and nedocromil were tested in ischaemic- and histamineinduced paw oedema models of mice. These antiallergic drugs (1–100 mg/kg, i.p.) failed to suppress these oedemata, but enhanced the suppressions by a low dose of dexamethasone (0.1 mg/kg, s.c.) at 3–8 h after Dex injection. The mode of effects by anti-allergic drugs resembled that of a natural antioxidant (α-tocopherol, β-carotene etc.), and was different from that of an immunosuppressant like FK506. The enhancing potencies of the two anti-allergic drugs were similar at 6 h after Dex in both oedemata, and were diminished by superoxide dismutase (SOD) or catalase (i.p.). Cycloheximide completely abolished suppressions. Nedocromil, but not cromoglycate, inhibits inflammatory events. Therefore, there are common unknown actions by which the two anti-allergics enhance suppression by Dex. A possible mechanism of this action was supposed to enhance the superoxide and/or hydrogen peroxide-dependent glucocorticoid receptor (GR) signalling in the target cells.


2018 ◽  
Vol 19 (12) ◽  
pp. 4078 ◽  
Author(s):  
Dahn Clemens ◽  
Michael Duryee ◽  
Cleofes Sarmiento ◽  
Andrew Chiou ◽  
Jacob McGowan ◽  
...  

Doxycycline (DOX), a derivative of tetracycline, is a broad-spectrum antibiotic that exhibits a number of therapeutic activities in addition to its antibacterial properties. For example, DOX has been used in the management of a number of diseases characterized by chronic inflammation. One potential mechanism by which DOX inhibits the progression of these diseases is by reducing oxidative stress, thereby inhibiting subsequent lipid peroxidation and inflammatory responses. Herein, we tested the hypothesis that DOX directly scavenges reactive oxygen species (ROS) and inhibits the formation of redox-mediated malondialdehyde-acetaldehyde (MAA) protein adducts. Using a cell-free system, we demonstrated that DOX scavenged reactive oxygen species (ROS) produced during the formation of MAA-adducts and inhibits the formation of MAA-protein adducts. To determine whether DOX scavenges specific ROS, we examined the ability of DOX to directly scavenge superoxide and hydrogen peroxide. Using electron paramagnetic resonance (EPR) spectroscopy, we found that DOX directly scavenged superoxide, but not hydrogen peroxide. Additionally, we found that DOX inhibits MAA-induced activation of Nrf2, a redox-sensitive transcription factor. Together, these findings demonstrate the under-recognized direct antioxidant property of DOX that may help to explain its therapeutic potential in the treatment of conditions characterized by chronic inflammation and increased oxidative stress.


2018 ◽  
Vol 20 (24) ◽  
pp. 7916-7920 ◽  
Author(s):  
Prerona Bora ◽  
Preeti Chauhan ◽  
Suman Manna ◽  
Harinath Chakrapani

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