A mitochondrial-targeting iridium(III) complex for H2O2-responsive and oxidative stress amplified two-photon photodynamic therapy

2021 ◽  
Author(s):  
Xinxing Liao ◽  
shen jinchao ◽  
Weijun Wu ◽  
Shi Kuang ◽  
Mingwei Lin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Photodynamic Therapy ◽  
Reactive Oxygen ◽  
Tumour Cells ◽  
Oxygen Species ◽  
Mitochondrial Targeting ◽  
Cancer Treatments ◽  
Two Photon ◽  
And Oxidative Stress

High amounts of gluthathione in tumour cells are able to decrease the effectivness of cancer treatments by capturing the therapeutically necessary reactive oxygen species during the photodynamic therapy (PDT) process....

scholarly journals Advanced Glycation End Products and Oxidative Stress in a Hyperglycaemic Environment

2021 ◽  
Author(s):  
Akio Nakamura ◽  
Ritsuko Kawahrada
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Advanced Glycation End Products ◽  
Reactive Oxygen ◽  
Protein Glycation ◽  
Oxygen Species ◽  
Advanced Glycation ◽  
Glycation End Products ◽  
End Products ◽  
And Oxidative Stress

Protein glycation is the random, nonenzymatic reaction of sugar and protein induced by diabetes and ageing; this process is quite different from glycosylation mediated by the enzymatic reactions catalysed by glycosyltransferases. Schiff bases form advanced glycation end products (AGEs) via intermediates, such as Amadori compounds. Although these AGEs form various molecular species, only a few of their structures have been determined. AGEs bind to different AGE receptors on the cell membrane and transmit signals to the cell. Signal transduction via the receptor of AGEs produces reactive oxygen species in cells, and oxidative stress is responsible for the onset of diabetic complications. This chapter introduces the molecular mechanisms of disease onset due to oxidative stress, including reactive oxygen species, caused by AGEs generated by protein glycation in a hyperglycaemic environment.

Underlying mechanisms of reactive oxygen species and oxidative stress photoinduced by graphene and its surface-functionalized derivatives

2020 ◽  
Vol 7 (3) ◽  
pp. 782-792 ◽  
Author(s):  
Hongye Yao ◽  
Yang Huang ◽  
Xuan Li ◽  
Xuehua Li ◽  
Hongbin Xie ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Functional Groups ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Underlying Mechanisms ◽  
Transformation Processes ◽  
And Oxidative Stress

Graphene can be modified by different functional groups through various transformation processes in the environment.

scholarly journals Redox Regulation and Oxidative Stress: The Particular Case of the Stallion Spermatozoa

Antioxidants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 567 ◽  
Author(s):  
Fernando J. Peña ◽  
Cristian O’Flaherty ◽  
José M. Ortiz Rodríguez ◽  
Francisco E. Martín Cano ◽  
Gemma L. Gaitskell-Phillips ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Redox Regulation ◽  
Redox Homeostasis ◽  
Reactive Oxygen ◽  
Mitochondrial Activity ◽  
Oxygen Species ◽  
Redox Biology ◽  
Major Interest ◽  
And Oxidative Stress

Redox regulation and oxidative stress have become areas of major interest in spermatology. Alteration of redox homeostasis is recognized as a significant cause of male factor infertility and is behind the damage that spermatozoa experience after freezing and thawing or conservation in a liquid state. While for a long time, oxidative stress was just considered an overproduction of reactive oxygen species, nowadays it is considered as a consequence of redox deregulation. Many essential aspects of spermatozoa functionality are redox regulated, with reversible oxidation of thiols in cysteine residues of key proteins acting as an “on–off” switch controlling sperm function. However, if deregulation occurs, these residues may experience irreversible oxidation and oxidative stress, leading to malfunction and ultimately death of the spermatozoa. Stallion spermatozoa are “professional producers” of reactive oxygen species due to their intense mitochondrial activity, and thus sophisticated systems to control redox homeostasis are also characteristic of the spermatozoa in the horse. As a result, and combined with the fact that embryos can easily be collected in this species, horses are a good model for the study of redox biology in the spermatozoa and its impact on the embryo.

scholarly journals Arginine Biosynthesis Modulates Pyoverdine Production and Release in Pseudomonas putida as Part of the Mechanism of Adaptation to Oxidative Stress

2019 ◽  
Vol 201 (22) ◽  
Author(s):  
Laura Barrientos-Moreno ◽  
María Antonia Molina-Henares ◽  
Marta Pastor-García ◽  
María Isabel Ramos-González ◽  
Manuel Espinosa-Urgel
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Amino Acid ◽  
Pseudomonas Putida ◽  
Reactive Oxygen ◽  
Full Detail ◽  
Oxygen Species ◽  
Arginine Biosynthesis ◽  
Content Type ◽  
And Oxidative Stress

ABSTRACT Iron is essential for most life forms. Under iron-limiting conditions, many bacteria produce and release siderophores—molecules with high affinity for iron—which are then transported into the cell in their iron-bound form, allowing incorporation of the metal into a wide range of cellular processes. However, free iron can also be a source of reactive oxygen species that cause DNA, protein, and lipid damage. Not surprisingly, iron capture is finely regulated and linked to oxidative-stress responses. Here, we provide evidence indicating that in the plant-beneficial bacterium Pseudomonas putida KT2440, the amino acid l-arginine is a metabolic connector between iron capture and oxidative stress. Mutants defective in arginine biosynthesis show reduced production and release of the siderophore pyoverdine and altered expression of certain pyoverdine-related genes, resulting in higher sensitivity to iron limitation. Although the amino acid is not part of the siderophore side chain, addition of exogenous l-arginine restores pyoverdine release in the mutants, and increased pyoverdine production is observed in the presence of polyamines (agmatine and spermidine), of which arginine is a precursor. Spermidine also has a protective role against hydrogen peroxide in P. putida, whereas defects in arginine and pyoverdine synthesis result in increased production of reactive oxygen species. IMPORTANCE The results of this study show a previously unidentified connection between arginine metabolism, siderophore turnover, and oxidative stress in Pseudomonas putida. Although the precise molecular mechanisms involved have yet to be characterized in full detail, our data are consistent with a model in which arginine biosynthesis and the derived pathway leading to polyamine production function as a homeostasis mechanism that helps maintain the balance between iron uptake and oxidative-stress response systems.

Reactive oxygen species generated by renal ischemia and reperfusion trigger protection against subsequent renal ischemia and reperfusion injury in mice

2010 ◽  
Vol 298 (1) ◽  
pp. F158-F166 ◽  
Author(s):  
Jinu Kim ◽  
Hee-Seong Jang ◽  
Kwon Moo Park
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Renal Ischemia ◽  
Ischemia And Reperfusion ◽  
Oxygen Species ◽  
Ischemia And Reperfusion Injury ◽  
A Cell ◽  
Copper Zinc ◽  
And Oxidative Stress

Ischemic preconditioning by a single event of ischemia and reperfusion (SIRPC) dramatically protects renal function against ischemia and reperfusion (I/R) induced several weeks later. We recently reported that reactive oxygen species (ROS) and oxidative stress were sustained in a kidney that had functionally recovered from I/R injury, thus suggesting an association between SIRPC and ROS and oxidative stress. However, the role of ROS in SIRPC remains to be clearly elucidated. To assess the involvement of ROS in SIRPC, mice were subjected to SIRPC (30 min of bilateral renal ischemia and 8 days of reperfusion) and then exposed to I/R injury. Thirty minutes of bilateral renal ischemia in the non-SIRPC mice resulted in a marked increase in plasma creatinine levels 4 and 24 h after reperfusion, which was not observed in the I/R in the SIRPC mice. SIRPC resulted in increases in the levels of kidney superoxide. Administrations of manganese(III) tetrakis(1-methyl-4-pyridyl) porphyrin [MnTMPyP; a cell-permeable superoxide dismutase (SOD) mimetic] and N-acetylcysteine (NAc; a ROS scavenger) to SIRPC mice blocked the SIRPC-induced increase in superoxide levels and removed ∼48–64% of the functional protection of the SIRPC kidney. Additionally, these administrations significantly inhibited I/R-induced increases in superoxide formation, hydrogen peroxide production, and lipid peroxidation, along with the inhibition of I/R-induced reductions in the expression and activity of manganese SOD, copper-zinc SOD, and catalase. Furthermore, administrations of MnTMPyP or NAc inhibited the SIRPC-induced increase in inducible nitric oxide synthase expression but did not inhibit the SIRPC-induced increases in heat shock protein-25 expression. In conclusion, the renoprotection afforded by SIRPC was triggered by ROS generated by SIRPC.

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