scholarly journals Mitochondrially targeted fluorescent redox sensors

2017 ◽  
Vol 7 (2) ◽  
pp. 20160105 ◽  
Author(s):  
Kylie Yang ◽  
Jacek L. Kolanowski ◽  
Elizabeth J. New
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Redox Reactions ◽  
Chemical Biology ◽  
Fluorescent Protein ◽  
Oxygen Species ◽  
Mitochondrial Localization ◽  
Physiological Processes ◽  
Lipophilic Cation ◽  
Redox Sensors

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.

scholarly journals Intracellular Sources of ROS/H2O2 in Health and Neurodegeneration: Spotlight on Endoplasmic Reticulum

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 233
Author(s):  
Tasuku Konno ◽  
Eduardo Pinho Melo ◽  
Joseph E. Chambers ◽  
Edward Avezov
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Endoplasmic Reticulum ◽  
Neurodegenerative Diseases ◽  
Antioxidative Enzymes ◽  
Redox Reactions ◽  
Ros Production ◽  
Oxygen Species ◽  
Specific Target

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.

Investigating mitochondrial radical production using targeted probes

2004 ◽  
Vol 32 (6) ◽  
pp. 1011-1014 ◽  
Author(s):  
M.P. Murphy
Keyword(s):  
Reactive Oxygen Species ◽  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Oxygen Species ◽  
Mitochondrial Localization ◽  
Spin Traps ◽  
Active Moiety ◽  
Radical Production ◽  
Lipophilic Cation

A range of mitochondria-targeted probe molecules that comprise a lipophilic cation covalently attached to an active moiety have been developed. The lipophilic cation causes the accumulation of these molecules into mitochondria, driven by the mitochondrial membrane potential. To date, we have targeted antioxidants, spin traps, thiol reagents and DNA-alkylating compounds to mitochondria. The selective mitochondrial localization of these compounds enables us to investigate several aspects of the production of reactive oxygen species by mitochondria.

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

2021 ◽  
Author(s):  
Elizabeth Anotonovna Karnaukh ◽  
Ksenia B Bravaya
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Cytochrome C ◽  
Redox Potential ◽  
Redox Reactions ◽  
Cytochrome C Peroxidase ◽  
Biological Processes ◽  
Oxygen Species ◽  
Heme Cofactor ◽  
Excess Reactive Oxygen Species

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...

Functional comparison of Deinococcus radiodurans Dps proteins suggests distinct in vivo roles

2012 ◽  
Vol 447 (3) ◽  
pp. 381-391 ◽  
Author(s):  
Brian J. Reon ◽  
Khoa H. Nguyen ◽  
Gargi Bhattacharyya ◽  
Anne Grove
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Signal Peptide ◽  
Stress Responses ◽  
Cellular Localization ◽  
Fluorescent Protein ◽  
Deinococcus Radiodurans ◽  
Reactive Oxygen ◽  
Oxygen Species

Deinococcus radiodurans exhibits extreme resistance to DNA damage and is one of only few bacteria that encode two Dps (DNA protection during starvation) proteins. Dps-1 was shown previously to bind DNA with high affinity and to localize to the D. radiodurans nucleoid. A unique feature of Dps-2 is its predicted signal peptide. In the present paper, we report that Dps-2 assembly into a dodecamer requires the C-terminal extension and, whereas Dps-2 binds DNA with low affinity, it protects against degradation by reactive oxygen species. Consistent with a role for Dps-2 in oxidative stress responses, the Dps-2 promoter is up-regulated by oxidative stress, whereas the Dps-1 promoter is not. Although DAPI (4′,6-diamidino-2-phenylindole) staining of Escherichia coli nucleoids shows that Dps-1 can compact genomic DNA, such nucleoid condensation is absent from cells expressing Dps-2. A fusion of EGFP (enhanced green fluorescent protein) to the Dps-2 signal peptide results in green fluorescence at the perimeter of D. radiodurans cells. The differential response of the Dps-1 and Dps-2 promoters to oxidative stress, the distinct cellular localization of the proteins and the differential ability of Dps-1 and Dps-2 to attenuate hydroxyl radical production suggest distinct functional roles; whereas Dps-1 may function in DNA metabolism, Dps-2 may protect against exogenously derived reactive oxygen species.

scholarly journals Mechanisms of PEDF-mediated protection against reactive oxygen species damage in diabetic retinopathy and neuropathy

2014 ◽  
Vol 222 (3) ◽  
pp. R129-R139 ◽  
Author(s):  
Mina Elahy ◽  
Swati Baindur-Hudson ◽  
Vinicius F Cruzat ◽  
Philip Newsholme ◽  
Crispin R Dass
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Diabetic Retinopathy ◽  
Neuroprotective Effect ◽  
Pigment Epithelium ◽  
Protective Role ◽  
Oxygen Species ◽  
Physiological Processes ◽  
Pigment Epithelium Derived Factor

Pigment epithelium-derived factor (PEDF) is a pluripotent glycoprotein belonging to the serpin family. PEDF can stimulate several physiological processes such as angiogenesis, cell proliferation, and survival. Oxidative stress plays an important role in the occurrence of diabetic retinopathy (DR), which is the major cause of blindness in young diabetic adults. PEDF plays a protective role in DR and there is accumulating evidence of the neuroprotective effect of PEDF. In this paper, we review the role of PEDF and the mechanisms involved in its antioxidative, anti-inflammatory, and neuroprotective properties.

scholarly journals Activation of an AP1-Like Transcription Factor of the Maize Pathogen Cochliobolus heterostrophus in Response to Oxidative Stress and Plant Signals

2005 ◽  
Vol 4 (2) ◽  
pp. 443-454 ◽  
Author(s):  
Sophie Lev ◽  
Ruthi Hadar ◽  
Paolo Amedeo ◽  
Scott E. Baker ◽  
O. C. Yoder ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Transcription Factor ◽  
Oxidative Burst ◽  
Fluorescent Protein ◽  
Leaf Surface ◽  
Reactive Oxygen ◽  
Cochliobolus Heterostrophus ◽  
Oxygen Species ◽  
Plant Signals

ABSTRACT Redox sensing is a ubiquitous mechanism regulating cellular activity. Fungal pathogens face reactive oxygen species produced by the host plant's oxidative burst in addition to endogenous reactive oxygen species produced during aerobic metabolism. An array of preformed and induced detoxifying enzymes, including superoxide dismutase, catalases, and peroxidases, could allow fungi to infect plants despite the oxidative burst. We isolated a gene (CHAP1) encoding a redox-regulated transcription factor in Cochliobolus heterostrophus, a fungal pathogen of maize. CHAP1 is a bZIP protein that possesses two cysteine-rich domains structurally and functionally related to Saccharomyces cerevisiae YAP1. Deletion of CHAP1 in C. heterostrophus resulted in decreased resistance to oxidative stress caused by hydrogen peroxide and menadione, but the virulence of chap1 mutants was unaffected. Upon activation by oxidizing agents or plant signals, a green fluorescent protein (GFP)-CHAP1 fusion protein became localized in the nucleus. Expression of genes encoding antioxidant proteins was induced in the wild type but not in chap1 mutants. Activation of CHAP1 occurred from the earliest stage of plant infection, in conidial germ tubes on the leaf surface, and persisted during infection. Late in the course of infection, after extensive necrotic lesions were formed, GFP-CHAP1 redistributed to the cytosol in hyphae growing on the leaf surface. Localization of CHAP1 to the nucleus may, through changes in the redox state of the cell, provide a mechanism linking extracellular cues to transcriptional regulation during the plant-pathogen interaction.

Clinical aspects of reactive oxygen and nitrogen species

2004 ◽  
Vol 71 ◽  
pp. 121-133 ◽  
Author(s):  
Ascan Warnholtz ◽  
Maria Wendt ◽  
Michael August ◽  
Thomas Münzel
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Risk Factor ◽  
Endothelial Dysfunction ◽  
Vascular Tissue ◽  
Rapid Development ◽  
Reactive Oxygen ◽  
Clinical Aspects ◽  
No Production ◽  
Oxygen Species

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.

Danshensu Rescues Ischemia/Reperfusion Caused Human Hepatocyte Death

2018 ◽  
Vol 17 (2) ◽  
pp. 117-121
Author(s):  
Sun Maw-Sheng ◽  
Liang Chun-Ya ◽  
Hsieh Po-Chun ◽  
Kuo Chan-Yen
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Caspase 3 ◽  
Ischemia Reperfusion ◽  
Oxygen Species ◽  
Good Strategy ◽  
Ros Accumulation ◽  
Dichlorofluorescin Diacetate ◽  
Hepatocyte Damage ◽  
Hepatocyte Death

Apoptosis of hepatocyte, under ischemia/reperfusion (IR) conditions, has been identified as an essential process in the progression of liver transplantation. Under these conditions, mitochondria can become a threat to the cell because of their capacity to generate reactive oxygen species (ROS). Additionally, ROS overproduction may induce inflammation. As ROS accumulation appears to cause hepatocyte damage or death, there has been considerable interest in identifying the candidate natural products involved and in developing strategies to reduce oxidative stress. In this study, we use Danshensu as a candidate product to speculate whether has the protective effect on apoptotic hepatocyte upon IR. To speculate the apoptotic phenomena was reversed by Danshensu, we detected the p53, cleaved-caspase 3 expression by western blotting, as well as caspase-3 activity. Additionally, we analyzed the ROS levels by 2′,7′-dichlorofluorescin diacetate (DCF-DA) staining. We also detected the cell viability by WST-1. Results showed that Danshensu alleviated hypoxia-caused cell apoptosis via ROS overproduction. We suggested that Danshensu is a good strategy for treating hepatocyte damage upon IR.

scholarly journals 4-Hydroxychalcone Induces Cell Death via Oxidative Stress in MYCN-Amplified Human Neuroblastoma Cells

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Amnah M. Alshangiti ◽  
Eszter Tuboly ◽  
Shane V. Hegarty ◽  
Cathal M. McCarthy ◽  
Aideen M. Sullivan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Cell Death ◽  
Cytotoxic Effect ◽  
Neuroblastoma Cells ◽  
Reactive Oxygen ◽  
Prognostic Indicator ◽  
Oxygen Species ◽  
Human Neuroblastoma Cells ◽  
Human Neuroblastoma

Neuroblastoma is an embryonal malignancy that arises from cells of sympathoadrenal lineage during the development of the nervous system. It is the most common pediatric extracranial solid tumor and is responsible for 15% of childhood deaths from cancer. Fifty percent of cases are diagnosed as high-risk metastatic disease with a low overall 5-year survival rate. More than half of patients experience disease recurrence that can be refractory to treatment. Amplification of the MYCN gene is an important prognostic indicator that is associated with rapid disease progression and a poor prognosis, highlighting the need for new therapeutic approaches. In recent years, there has been an increasing focus on identifying anticancer properties of naturally occurring chalcones, which are secondary metabolites with variable phenolic structures. Here, we report that 4-hydroxychalcone is a potent cytotoxin for MYCN-amplified IMR-32 and SK-N-BE (2) neuroblastoma cells, when compared to non-MYCN-amplified SH-SY5Y neuroblastoma cells and to the non-neuroblastoma human embryonic kidney cell line, HEK293t. Moreover, 4-hydroxychalcone treatment significantly decreased cellular levels of the antioxidant glutathione and increased cellular reactive oxygen species. In addition, 4-hydroxychalcone treatment led to impairments in mitochondrial respiratory function, compared to controls. In support of this, the cytotoxic effect of 4-hydroxychalcone was prevented by co-treatment with either the antioxidant N-acetyl-L-cysteine, a pharmacological inhibitor of oxidative stress-induced cell death (IM-54) or the mitochondrial reactive oxygen species scavenger, Mito-TEMPO. When combined with the anticancer drugs cisplatin or doxorubicin, 4-hydroxychalcone led to greater reductions in cell viability than was induced by either anti-cancer agent alone. In summary, this study identifies a cytotoxic effect of 4-hydroxychalcone in MYCN-amplified human neuroblastoma cells, which rationalizes its further study in the development of new therapies for pediatric neuroblastoma.

Sign in / Sign up

Export Citation Format

Share Document