scholarly journals Mas-Mediated Antioxidant Effects Restore the Functionality of Angiotensin Converting Enzyme 2-Angiotensin-(1–7)-MasAxis in Diabetic Rat Carotid

2014 ◽  
Vol 2014 ◽  
pp. 1-20 ◽  
Author(s):  
Larissa Pernomian ◽  
Mayara Santos Gomes ◽  
Carolina Baraldi Araujo Restini ◽  
Ana Maria de Oliveira
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Type I Diabetes ◽  
Reactive Oxygen ◽  
Diabetic Rats ◽  
Diabetic Rat ◽  
Type I ◽  
Oxygen Species ◽  
Antioxidant Effects ◽  
Carotid Flow

We hypothesized that endothelial AT1-activated NAD(P)H oxidase-driven generation of reactive oxygen species during type I-diabetes impairs carotid ACE2-angiotensin-(1–7)-Masaxis functionality, which accounts for the impaired carotid flow in diabetic rats. We also hypothesized that angiotensin-(1–7) chronic treatment of diabetic rats restores carotid ACE2-angiotensin-(1–7)-Masaxis functionality and carotid flow. Relaxant curves for angiotensin II or angiotensin-(1–7) were obtained in carotid from streptozotocin-induced diabetic rats. Superoxide or hydrogen peroxide levels were measured by flow cytometry in carotid endothelial cells. Carotid flow was also determined. We found that endothelial AT1-activated NAD(P)H oxidase-driven generation of superoxide and hydrogen peroxide in diabetic rat carotid impairs ACE2-angiotensin-(1–7)-Masaxis functionality, which reduces carotid flow. In this mechanism, hydrogen peroxide derived from superoxide dismutation inhibits ACE2 activity in generating angiotensin-(1–7) seemingly by activatingICl,SWELL, while superoxide inhibits the nitrergicMas-mediated vasorelaxation evoked by angiotensin-(1–7). Angiotensin-(1–7) treatment of diabetic rats restored carotid ACE2-angiotensin-(1–7)-Masaxis functionality by triggering a positive feedback played by endothelialMasreceptors, that blunts endothelial AT1-activated NAD(P)H oxidase-driven generation of reactive oxygen species.Mas-mediated antioxidant effects also restored diabetic rat carotid flow, pointing to the contribution of ACE2-angiotensin-(1–7)-Masaxis in maintaining carotid flow.

Hydrogen peroxide-responsive AIE probe for imaging-guided organelle targeting and photodynamic cancer cell ablation

2021 ◽  
Author(s):  
Qian Wu ◽  
Youmei Li ◽  
Ying Li ◽  
Dong Wang ◽  
Ben Zhong Tang
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Cancer Cell ◽  
Reactive Oxygen ◽  
Living Cells ◽  
Oxygen Species ◽  
Cell Ablation ◽  
Selective Monitoring ◽  
Organelle Targeting

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...

scholarly journals Upconversion-based nanosystems for fluorescence sensing of pH and H2O2

2021 ◽  
Author(s):  
Chunning Sun ◽  
Michael Gradzielski
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Excitation Energy ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Fluorescence Sensing ◽  
Living Organisms

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...

scholarly journals Novel Antioxidant Properties of Doxycycline

2018 ◽  
Vol 19 (12) ◽  
pp. 4078 ◽  
Author(s):  
Dahn Clemens ◽  
Michael Duryee ◽  
Cleofes Sarmiento ◽  
Andrew Chiou ◽  
Jacob McGowan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Chronic Inflammation ◽  
Antioxidant Properties ◽  
Antibacterial Properties ◽  
Reactive Oxygen ◽  
Protein Adducts ◽  
Oxygen Species ◽  
Free System

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.

A Vinyl-Boronate Ester-Based Persulfide Donor Controllable by Hydrogen Peroxide, a Reactive Oxygen Species (ROS)

2018 ◽  
Vol 20 (24) ◽  
pp. 7916-7920 ◽  
Author(s):  
Prerona Bora ◽  
Preeti Chauhan ◽  
Suman Manna ◽  
Harinath Chakrapani
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Boronate Ester

A charge transfer assisted fluorescent probe for selective detection of hydrogen peroxide among different reactive oxygen species

2012 ◽  
Vol 48 (39) ◽  
pp. 4719 ◽  
Author(s):  
Manoj Kumar ◽  
Naresh Kumar ◽  
Vandana Bhalla ◽  
Parduman Raj Sharma ◽  
Yasrib Qurishi
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Charge Transfer ◽  
Fluorescent Probe ◽  
Reactive Oxygen ◽  
Selective Detection ◽  
Oxygen Species ◽  
A Charge

scholarly journals Caffeic Acid - Potential Antioxidant in Cultured Human Retinal Pigment Epithelial Cells

1970 ◽  
Vol 66 (2) ◽  
Author(s):  
Dumitriţa RUGINǍ ◽  
Adela PINTEA ◽  
Raluca PÂRLOG ◽  
Andreea VARGA
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Protective Effect ◽  
Caffeic Acid ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Antioxidant Defence ◽  
Rpe Cells ◽  
In Cells

Oxidative stress causes biological changes responsible for carcinogenesis and aging in human cells. The retinal pigmented epithelium is continuously exposed to oxidative stress. Therefore reactive oxygen species (ROS) and products of lipid peroxidation accumulate in RPE. Neutralization of ROS occurs in retina by the action of antioxidant defence systems. In the present study, the protective effect of caffeic acid (3,4-dihydroxy cinnamic acid), a dietary phenolic compound, has been examined in normal and in oxidative stress conditions (500 µM peroxide oxygen) in cultures human epithelial pigment retinal cells (Nowak, M. et al.). The cell viability, the antioxidant enzymes activity (CAT, GPx, SOD) and the level of intracellular reactive oxygen species (ROS) were determined. Exposure to l00 µM caffeic acid for 24 h induced cellular changes indicating the protective effect of caffeic acid in RPE cells. Caffeic acid did not show any cytotoxic effect at concentrations lower than 200 μM in culture medium. Treatment of RPE cells with caffeic acid causes an increase of catalase, glutathione peroxidase and superoxide dismutase activity, especially in cells treated with hydrogen peroxide. Caffeic acid causes a decrease of ROS level in cells treated with hydrogen peroxide. This study proved that caffeic acid or food that contain high levels of this phenolic acid may have beneficial effects in prevention of retinal diseases associated with oxidative stress by improving antioxidant defence systems.

scholarly journals Reactive oxygen species oxidize STING and suppress interferon production

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Lili Tao ◽  
Andrew Lemoff ◽  
Guoxun Wang ◽  
Christina Zarek ◽  
Alexandria Lowe ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Redox Regulation ◽  
Reactive Oxygen ◽  
Interferon Response ◽  
Cellular Respiration ◽  
Type I ◽  
Oxygen Species ◽  
Interferon Production ◽  
Dna Sensing ◽  
Cytoplasmic Dna

Reactive oxygen species (ROS) are by-products of cellular respiration that can promote oxidative stress and damage cellular proteins and lipids. One canonical role of ROS is to defend the cell against invading bacterial and viral pathogens. Curiously, some viruses, including herpesviruses, thrive despite the induction of ROS, suggesting that ROS are beneficial for the virus. However, the underlying mechanisms remain unclear. Here, we found that ROS impaired interferon response during murine herpesvirus infection and that the inhibition occurred downstream of cytoplasmic DNA sensing. We further demonstrated that ROS suppressed the type I interferon response by oxidizing Cysteine 147 on murine stimulator of interferon genes (STING), an ER-associated protein that mediates interferon response after cytoplasmic DNA sensing. This inhibited STING polymerization and activation of downstream signaling events. These data indicate that redox regulation of Cysteine 147 of mouse STING, which is equivalent to Cysteine 148 of human STING, controls interferon production. Together, our findings reveal that ROS orchestrates anti-viral immune responses, which can be exploited by viruses to evade cellular defenses.

Abscisic acid and hydrogen peroxide induce a novel maize group C MAP kinase gene, ZmMPK7, which is responsible for the removal of reactive oxygen species

Planta ◽  
2008 ◽  
Vol 229 (3) ◽  
pp. 485-495 ◽  
Author(s):  
Xiao-juan Zong ◽  
Da-peng Li ◽  
Ling-kun Gu ◽  
De-quan Li ◽  
Li-xia Liu ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Abscisic Acid ◽  
Map Kinase ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Kinase Gene
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