The Redox Potential of a Heme Cofactor in Nitrosomonas europaea Cytochrome c Peroxidase: A Polarizable QM/MM Study

Author(s):  
Elizabeth Anotonovna Karnaukh ◽  
Ksenia B Bravaya

Redox reactions are crucial to biological processes that protect organisms against oxidative stress. Metalloenzymes, such as peroxidases which reduce excess reactive oxygen species into water, play a key role in...

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.


Nanoscale ◽  
2022 ◽  
Author(s):  
Yijun Yu ◽  
Sheng Zhao ◽  
Deao Gu ◽  
Bijun Zhu ◽  
Hanxiao Liu ◽  
...  

Periodontitis, an inflammatory disease of oxidative stress, occurs due to the excess reactive oxygen species (ROS) contributing to cell and tissue damage that in turn leads to alveolar bone resorption...


2018 ◽  
Vol 30 (1) ◽  
pp. 174
Author(s):  
Y.-J. Niu ◽  
N.-H. Kim ◽  
X.-S. Cui

C-Phycocyanin (CP) is a biliprotein enriched in blue-green algae that is known to possess antioxidant, anti-apoptosis, anti-inflammatory, and radical-scavenging properties in somatic cells. However, the protective effect of CP on porcine embryo developmental competence in vitro remains unclear. In the present study, we investigated the effect of CP on the development of porcine early embryos as well as its underlying mechanisms exposing them to H2O2 to induce oxidative stress. The levels of reactive oxygen species, mitochondrial membrane potential, apoptosis, DNA damage, and autophagy in the blastocysts were observed by staining with 2′,7′-dichlorodihydrofluorescein diacetate (H2DCF-DA), 5,5′,6,6’-tetrachloro-1,1′,3,3′-tetraethyl-imidacarbocyanine iodide (JC-1), terminal deoxynucleotidyl transferase-mediated 2′-deoxyuridine 5′-triphosphate (dUTP) nick-end labelling (TUNEL), anti-cytochrome c, and anti-γH2A.X (Ser139), respectively. Colocalization assay of mitochondria and cytochrome c of blastocysts were staining with MitoTracker Red CMXRos and anti-cytochrome c. All data were subjected to one-way ANOVA. Different concentrations of CP (1, 2, 5, 8, 10 µg mL−1) were added to porcine zygote medium 5 (PZM-5, l-glutamine concentration of PZM-3 was modified from 1 to 2 mM) during in vitro culture. The results showed that 5 µg mL−1 CP significantly increased blastocyst formation (62.5 ± 2.1 v. 52.7 ± 2.4; P < 0.05) and hatching rate (10.9 ± 1.9 v. 36.6 ± 5.2; P < 0.05) compared with controls. Blastocyst formation (53.1 ± 2.3 v. 40.1 ± 2.3; P < 0.05) and quality were significantly increased in the 50 µM H2O2 treatment group following 5 µg mL−1 CP addition. C-Phycocyanin prevented the H2O2-induced compromise of mitochondrial membrane potential, release of cytochrome c from the mitochondria, and generation of reactive oxygen species. Furthermore, apoptosis, DNA damage level, and autophagy in the blastocysts were attenuated by supplementation of CP in the H2O2-induced oxidative injury group compared with that in controls. These results suggest that CP has beneficial effects on the development of porcine parthenotes by attenuating mitochondrial dysfunction and oxidative stress.


2017 ◽  
Vol 7 (2) ◽  
pp. 20160105 ◽  
Author(s):  
Kylie Yang ◽  
Jacek L. Kolanowski ◽  
Elizabeth J. New

The balance of oxidants and antioxidants within the cell is crucial for maintaining health, and regulating physiological processes such as signalling. Consequently, imbalances between oxidants and antioxidants are now understood to lead to oxidative stress, a physiological feature that underlies many diseases. These processes have spurred the field of chemical biology to develop a plethora of sensors, both small-molecule and fluorescent protein-based, for the detection of specific oxidizing species and general redox balances within cells. The mitochondrion, in particular, is the site of many vital redox reactions. There is therefore a need to target redox sensors to this particular organelle. It has been well established that targeting mitochondria can be achieved by the use of a lipophilic cation-targeting group, or by utilizing natural peptidic mitochondrial localization sequences. Here, we review how these two approaches have been used by a number of researchers to develop mitochondrially localized fluorescent redox sensors that are already proving useful in providing insights into the roles of reactive oxygen species in the mitochondria.


Drug Research ◽  
2019 ◽  
Vol 69 (10) ◽  
pp. 523-527
Author(s):  
Fatemeh Samiei ◽  
Hanieh Sajjadi ◽  
Akram Jamshidzadeh ◽  
Enayatollah Seydi ◽  
Jalal Pourahmad

AbstractRivaroxaban as a small molecule is able to directly and reversibly inhibit the factor Xa. This study was designed to figure out the evaluation effect of rivaroxaban on mitochondria obtained from rat kidneys. We isolated mitochondria from rat kidneys using gradient centrifugation. Then, the toxicity parameters including succinate dehydrogenase (SDH) activity, reactive oxygen species (ROS) formation, mitochondrial swelling, mitochondrial membrane potential (MMP) collapse and cytochrome c release were measured in kidneys mitochondria following the exposure to rivaroxaban. The results showed that rivaroxaban (1.4 and 2.8 mM) raised the reactive oxygen species (ROS) generation, swelling in the mitochondria, collapse in the mitochondrial membrane potential (MMP) and cytochrome c release in the mitochondria isolated from kidneys. While, rivaroxaban at a higher concentration of 5.6 mM showed the opposite effect compared to other lower concentrations. The results indicate that rivaroxaban may have antioxidant effects at high concentrations. The results suggest that rivaroxaban (5.6 mM) has protective effects against oxidative stress and mitochondrial toxicity.


2016 ◽  
Vol 9 (3) ◽  
pp. 113-116 ◽  
Author(s):  
Kate Duhig ◽  
Lucy C Chappell ◽  
Andrew H Shennan

Oxidative stress is implicated in the pathophysiology of many reproductive complications including infertility, miscarriage, pre-eclampsia, fetal growth restriction and preterm labour. The presence of excess reactive oxygen species can lead to cellular damage of deoxyribonucleic acids, lipids and proteins. Antioxidants protect cells from peroxidation reactions, limiting cellular damage and helping to maintain cellular membrane integrity. There is overwhelming evidence for oxidative stress causing harm in reproduction. However, there is sparse evidence that supplementation with commonly used antioxidants (mostly vitamins C and E) makes any difference in overcoming oxidative stress or reversing disease processes. There may be potential for antioxidant therapy to ameliorate or prevent disease, but this requires a thorough understanding of the mechanism of action and specificity of currently used antioxidants.


2004 ◽  
Vol 71 ◽  
pp. 121-133 ◽  
Author(s):  
Ascan Warnholtz ◽  
Maria Wendt ◽  
Michael August ◽  
Thomas Münzel

Endothelial dysfunction in the setting of cardiovascular risk factors, such as hypercholesterolaemia, hypertension, diabetes mellitus and chronic smoking, as well as in the setting of heart failure, has been shown to be at least partly dependent on the production of reactive oxygen species in endothelial and/or smooth muscle cells and the adventitia, and the subsequent decrease in vascular bioavailability of NO. Superoxide-producing enzymes involved in increased oxidative stress within vascular tissue include NAD(P)H-oxidase, xanthine oxidase and endothelial nitric oxide synthase in an uncoupled state. Recent studies indicate that endothelial dysfunction of peripheral and coronary resistance and conductance vessels represents a strong and independent risk factor for future cardiovascular events. Ways to reduce endothelial dysfunction include risk-factor modification and treatment with substances that have been shown to reduce oxidative stress and, simultaneously, to stimulate endothelial NO production, such as inhibitors of angiotensin-converting enzyme or the statins. In contrast, in conditions where increased production of reactive oxygen species, such as superoxide, in vascular tissue is established, treatment with NO, e.g. via administration of nitroglycerin, results in a rapid development of endothelial dysfunction, which may worsen the prognosis in patients with established coronary artery disease.


Sign in / Sign up

Export Citation Format

Share Document