In Vivo Imaging of Retinal Oxidative Stress Using a Reactive Oxygen Species–Activated Fluorescent Probe

Oxidative stress mediated by reactive oxygen species (ROS) is linked to degenerative conditions in humans and damage to an array of cellular components. However, it is unclear which molecular target(s) may be the primary “Achilles’ heel” of organisms, accounting for the inhibitory action of ROS. Rli1p (ABCE1) is an essential and highly conserved protein of eukaryotes and archaea that requires notoriously ROS-labile cofactors (Fe-S clusters) for its functions in protein synthesis. In this study, we tested the hypothesis that ROS toxicity is caused by Rli1p dysfunction. In addition to being essential, Rli1p activity (in nuclear ribosomal-subunit export) was shown to be impaired by mild oxidative stress in yeast. Furthermore, prooxidant resistance was decreased by RLI1 repression and increased by RLI1 overexpression. This Rlip1 dependency was abolished during anaerobicity and accentuated in cells expressing a FeS cluster–defective Rli1p construct. The protein's FeS clusters appeared ROS labile during in vitro incubations, but less so in vivo. Instead, it was primarily55FeS-cluster supply to Rli1p that was defective in prooxidant-exposed cells. The data indicate that, owing to its essential nature but dependency on ROS-labile FeS clusters, Rli1p function is a primary target of ROS action. Such insight could help inform new approaches for combating oxidative stress–related disease.

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Protein-L-isoaspartate O-methyltransferase is required for in vivo control of oxidative damage in red blood cells

Haematologica ◽

10.3324/haematol.2020.266676 ◽

2020 ◽

pp. 0-0

Author(s):

Angelo D’Alessandro ◽

Ariel Hay ◽

Monika Dzieciatkowska ◽

Benjamin C. Brown ◽

Evan J Morrison ◽

...

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Oxidative Damage ◽

Red Blood Cells ◽

Blood Cells ◽

Reactive Oxygen ◽

Metabolic Reprogramming ◽

Oxygen Species ◽

Common Amino Acid

Red blood cells have the special challenge of a large amount of reactive oxygen species (from their substantial iron load and Fenton reactions) combined with the inability to synthesize new gene products. Considerable progress has been made in elucidating the multiple pathways by which red blood cells neutralize reactive oxygen species via NADPH driven redox reactions. However, far less is known about how red blood cells repair the inevitable damage that does occur when reactive oxygen species break through anti-oxidant defenses. When structural and functional proteins become oxidized, the only remedy available to red blood cells is direct repair of the damaged molecules, as red blood cells cannot synthesize new proteins. Amongst the most common amino acid targets of oxidative damage is the conversion of asparagine and aspartate side chains into a succinimidyl group through deamidation or dehydration, respectively. Red blood cells express an L-Isoaspartyl methyltransferase (PIMT, gene name PCMT1) that can convert succinimidyl groups back to an aspartate. Herein, we report that deletion of PCMT1 significantly alters red blood cell metabolism in a healthy state, but does not impair the circulatory lifespan of red blood cells. Through a combination of genetic ablation, bone marrow transplantation and oxidant stimulation with phenylhydrazine in vivo or blood storage ex vivo, we use omics approaches to show that, when animals are exposed to oxidative stress, red blood cells from PCMT1 knockout undergo significant metabolic reprogramming and increased hemolysis. This is the first report of an essential role of PCMT1 for normal RBC circulation during oxidative stress.

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Inhibition of NOX1 mitigates blood pressure increases in elastin insufficiency

Function ◽

10.1093/function/zqab015 ◽

2021 ◽

Author(s):

Angela Troia ◽

Russell H Knutsen ◽

Carmen M Halabi ◽

Daniela Malide ◽

Zu Xi Yu ◽

...

Keyword(s):

Oxidative Stress ◽

Blood Pressure ◽

Reactive Oxygen Species ◽

Systolic Blood Pressure ◽

Blood Pressure Response ◽

Reactive Oxygen ◽

Vascular Wall ◽

Vascular Stiffness ◽

Oxygen Species

Abstract Elastin insufficiency leads to the cardiovascular hallmarks of the contiguous gene deletion disorder, Williams-Beuren syndrome, including hypertension and vascular stiffness. Previous studies showed that Williams-Beuren syndrome deletions that extended to include the NCF1 gene were associated with lower blood pressure and reduced vascular stiffness. NCF1 encodes for p47phox, the regulatory component of the NOX1 NADPH oxidase complex, that generates reactive oxygen species in the vascular wall. Dihydroethidium and 8-hydroxyguanosine staining of mouse aortas confirmed that Eln heterozygotes (Eln+/-) had greater reactive oxygen species (ROS) levels than wild types (Eln+/+), a finding that was negated in vessels cultured without hemodynamic stressors. To analyze the Nox effect on elastin insufficiency, we utilized both genetic and chemical manipulations. Both Ncf1 haploinsufficiency (Ncf1+/-) and Nox1 insufficiency (Nox1-/y) decreased oxidative stress and systolic blood pressure in Eln+/- without modifying vascular structure. Chronic treatment with apocynin, a p47phox inhibitor, lowered systolic blood pressure in Eln+/-, but had no impact on Eln+/+ controls. In vivo dosing with phenylephrine produced an augmented blood pressure response in Eln+/- relative to Eln+/+, and genetic modifications or drug-based interventions that lower Nox1 expression reduce the hypercontractile response to phenylephrine in Eln+/- mice to Eln+/+ levels. These results indicate that the mechanical and structural differences caused by elastin insufficiency leading to oscillatory flow can perpetuate oxidative stress conditions which are linked to hypertension, and that by lowering the Nox1-mediated capacity for vascular ROS production, blood pressure differences can be normalized.

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In Vivo Quantification of Reactive Oxygen Species Demonstrates High Levels of Oxidative Stress in Base Excision Repair-Deficient Caenorhabditis Elegans: Implications for Associative Metabolic Phenotypes

10.15760/honors.10 ◽

2013 ◽

Author(s):

Travis Hase

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Caenorhabditis Elegans ◽

Base Excision Repair ◽

Excision Repair ◽

Reactive Oxygen ◽

Oxygen Species ◽

Metabolic Phenotypes ◽

Base Excision

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Elesclomol-induced increase of mitochondrial reactive oxygen species impairs glioblastoma stem-like cell survival and tumor growth

Journal of Experimental & Clinical Cancer Research ◽

10.1186/s13046-021-02031-4 ◽

2021 ◽

Vol 40 (1) ◽

Author(s):

Mariachiara Buccarelli ◽

Quintino Giorgio D’Alessandris ◽

Paola Matarrese ◽

Cristiana Mollinari ◽

Michele Signore ◽

...

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Cell Death ◽

Molecular Mechanisms ◽

Reactive Oxygen ◽

Strong Increase ◽

Oxygen Species ◽

Mitochondrial Reactive Oxygen Species

Abstract Background Glioblastoma (GBM) is the most common and aggressive primary malignant brain tumor in adults, characterized by a poor prognosis mainly due to recurrence and therapeutic resistance. It has been widely demonstrated that glioblastoma stem-like cells (GSCs), a subpopulation of tumor cells endowed with stem-like properties is responsible for tumor maintenance and progression. Moreover, it has been demonstrated that GSCs contribute to GBM-associated neovascularization processes, through different mechanisms including the transdifferentiation into GSC-derived endothelial cells (GdECs). Methods In order to identify druggable cancer-related pathways in GBM, we assessed the effect of a selection of 349 compounds on both GSCs and GdECs and we selected elesclomol (STA-4783) as the most effective agent in inducing cell death on both GSC and GdEC lines tested. Results Elesclomol has been already described to be a potent oxidative stress inducer. In depth investigation of the molecular mechanisms underlying GSC and GdEC response to elesclomol, confirmed that this compound induces a strong increase in mitochondrial reactive oxygen species (ROS) in both GSCs and GdECs ultimately leading to a non-apoptotic copper-dependent cell death. Moreover, combined in vitro treatment with elesclomol and the alkylating agent temozolomide (TMZ) enhanced the cytotoxicity compared to TMZ alone. Finally, we used our experimental model of mouse brain xenografts to test the combination of elesclomol and TMZ and confirmed their efficacy in vivo. Conclusions Our results support further evaluation of therapeutics targeting oxidative stress such as elesclomol with the aim of satisfying the high unmet medical need in the management of GBM.

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Anti-Inflammatory and Reactive Oxygen Species Suppression through Aspirin Pretreatment to Treat Hyperoxia-Induced Acute Lung Injury in NF-κB–Luciferase Inducible Transgenic Mice

Antioxidants ◽

10.3390/antiox9050429 ◽

2020 ◽

Vol 9 (5) ◽

pp. 429 ◽

Cited By ~ 2

Author(s):

Chuan-Mu Chen ◽

Yu-Tang Tung ◽

Chi-Hsuan Wei ◽

Po-Ying Lee ◽

Wei Chen

Keyword(s):

Reactive Oxygen Species ◽

Acute Lung Injury ◽

Lung Injury ◽

Transgenic Mice ◽

In Vivo Imaging ◽

Reactive Oxygen ◽

Luciferase Expression ◽

Oxygen Species ◽

Anti Inflammatory

Acute lung injury (ALI), a common cause of morbidity and mortality in intensive care units, results from either direct intra-alveolar injury or indirect injury following systemic inflammation and oxidative stress. Adequate tissue oxygenation often requires additional supplemental oxygen. However, hyperoxia causes lung injury and pathological changes. Notably, preclinical data suggest that aspirin modulates numerous platelet-mediated processes involved in ALI development and resolution. Our previous study suggested that prehospital aspirin use reduced the risk of ALI in critically ill patients. This research uses an in vivo imaging system (IVIS) to investigate the mechanisms of aspirin’s anti-inflammatory and antioxidant effects on hyperoxia-induced ALI in nuclear factor κB (NF-κB)–luciferase transgenic mice. To define mechanisms through which NF-κB causes disease, we developed transgenic mice that express luciferase under the control of NF-κB, enabling real-time in vivo imaging of NF-κB activity in intact animals. An NF-κB-dependent bioluminescent signal was used in transgenic mice carrying the luciferase genes to monitor the anti-inflammatory effects of aspirin. These results demonstrated that pretreatment with aspirin reduced luciferase expression, indicating that aspirin reduces NF-κB activation. In addition, aspirin reduced reactive oxygen species expression, the number of macrophages, neutrophil infiltration and lung edema compared with treatment with only hyperoxia treatment. In addition, we demonstrated that pretreatment with aspirin significantly reduced the protein levels of phosphorylated protein kinase B, NF-κB and tumor necrosis factor α in NF-κB–luciferase+/+ transgenic mice. Thus, the effects of aspirin on the anti-inflammatory response and reactive oxygen species suppressive are hypothesized to occur through the NF-κB signaling pathway. This study demonstrated that aspirin exerts a protective effect for hyperoxia-induced lung injury and thus is currently the drug conventionally used for hyperoxia-induced lung injury.

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Mechanism of Oxidative Stress in Neurodegeneration

Oxidative Medicine and Cellular Longevity ◽

10.1155/2012/428010 ◽

2012 ◽

Vol 2012 ◽

pp. 1-11 ◽

Cited By ~ 384

Author(s):

Sonia Gandhi ◽

Andrey Y. Abramov

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Free Radicals ◽

Neurodegenerative Disease ◽

Reactive Oxygen ◽

Biological Tissues ◽

Antioxidant Systems ◽

Oxygen Species

Biological tissues require oxygen to meet their energetic demands. However, the consumption of oxygen also results in the generation of free radicals that may have damaging effects on cells. The brain is particularly vulnerable to the effects of reactive oxygen species due to its high demand for oxygen, and its abundance of highly peroxidisable substrates. Oxidative stress is caused by an imbalance in the redox state of the cell, either by overproduction of reactive oxygen species, or by dysfunction of the antioxidant systems. Oxidative stress has been detected in a range of neurodegenerative disease, and emerging evidence from in vitro and in vivo disease models suggests that oxidative stress may play a role in disease pathogenesis. However, the promise of antioxidants as novel therapies for neurodegenerative diseases has not been borne out in clinical studies. In this review, we critically assess the hypothesis that oxidative stress is a crucial player in common neurodegenerative disease and discuss the source of free radicals in such diseases. Furthermore, we examine the issues surrounding the failure to translate this hypothesis into an effective clinical treatment.

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