scholarly journals Identification of Nrf2-responsive microRNA networks as putative mediators of myocardial reductive stress

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Justin M. Quiles ◽  
Mark E. Pepin ◽  
Sini Sunny ◽  
Sandeep B. Shelar ◽  
Anil K. Challa ◽  
...  
Keyword(s):  
Antioxidant Response ◽  
Transcriptional Dysregulation ◽  
Reductive Stress ◽  
Cardiac Pathophysiology ◽  
Mechanistic Investigation ◽  
Antioxidant Response Elements ◽  
Microrna Networks ◽  
Post Transcriptional Regulation ◽  
The Relationship ◽  
Sustained Activation

AbstractAlthough recent advances in the treatment of acute coronary heart disease have reduced mortality rates, few therapeutic strategies exist to mitigate the progressive loss of cardiac function that manifests as heart failure. Nuclear factor, erythroid 2 like 2 (Nfe2l2, Nrf2) is a transcriptional regulator that is known to confer transient myocardial cytoprotection following acute ischemic insult; however, its sustained activation paradoxically causes a reductive environment characterized by excessive antioxidant activity. We previously identified a subset of 16 microRNAs (miRNA) significantly diminished in Nrf2-ablated (Nrf2−/−) mouse hearts, leading to the hypothesis that increasing levels of Nrf2 activation augments miRNA induction and post-transcriptional dysregulation. Here, we report the identification of distinct miRNA signatures (i.e. “reductomiRs”) associated with Nrf2 overexpression in a cardiac-specific and constitutively active Nrf2 transgenic (caNrf2-Tg) mice expressing low (TgL) and high (TgH) levels. We also found several Nrf2 dose-responsive miRNAs harboring proximal antioxidant response elements (AREs), implicating these “reductomiRs” as putative meditators of Nrf2-dependent post-transcriptional regulation. Analysis of mRNA-sequencing identified a complex network of miRNAs and effector mRNAs encoding known pathological hallmarks of cardiac stress-response. Altogether, these data support Nrf2 as a putative regulator of cardiac miRNA expression and provide novel candidates for future mechanistic investigation to understand the relationship between myocardial reductive stress and cardiac pathophysiology.

scholarly journals Sustained Activation of Nuclear Erythroid 2-Related Factor 2/Antioxidant Response Element Signaling Promotes Reductive Stress in the Human Mutant Protein Aggregation Cardiomyopathy in Mice

2011 ◽  
Vol 14 (6) ◽  
pp. 957-971 ◽  
Author(s):  
Namakkal Soorappan Rajasekaran ◽  
Saradhadevi Varadharaj ◽  
Gayatri D. Khanderao ◽  
Christopher J. Davidson ◽  
Sankaranarayanan Kannan ◽  
...  
Keyword(s):  
Protein Aggregation ◽  
Antioxidant Response ◽  
Mutant Protein ◽  
Related Factor ◽  
Antioxidant Response Element ◽  
Response Element ◽  
Reductive Stress ◽  
Sustained Activation

ZFARED: A Database of the Antioxidant Response Elements in Zebrafish

2020 ◽  
Vol 15 (5) ◽  
pp. 415-419
Author(s):  
Azhwar Raghunath ◽  
Raju Nagarajan ◽  
Ekambaram Perumal
Keyword(s):  
Target Genes ◽  
Antioxidant Response ◽  
Zebrafish Genome ◽  
Promoter Regions ◽  
Protein Coding ◽  
Response Elements ◽  
Toxic Agents ◽  
Upstream Promoter ◽  
Its Gene ◽  
Antioxidant Response Elements

Background: Antioxidant Response Elements (ARE) play a key role in the expression of Nrf2 target genes by regulating the Keap1-Nrf2-ARE pathway, which offers protection against toxic agents and oxidative stress-induced diseases. Objective: To develop a database of putative AREs for all the genes in the zebrafish genome. This database will be helpful for researchers to investigate Nrf2 regulatory mechanisms in detail. Methods: To facilitate researchers functionally characterize zebrafish AREs, we have developed a database of AREs, Zebrafish Antioxidant Response Element Database (ZFARED), for all the protein-coding genes including antioxidant and mitochondrial genes in the zebrafish genome. The front end of the database was developed using HTML, JavaScript, and CSS and tested in different browsers. The back end of the database was developed using Perl scripts and Perl-CGI and Perl- DBI modules. Results: ZFARED is the first database on the AREs in zebrafish, which facilitates fast and efficient searching of AREs. AREs were identified using the in-house developed Perl algorithms and the database was developed using HTML, JavaScript, and Perl-CGI scripts. From this database, researchers can access the AREs based on chromosome number (1 to 25 and M for mitochondria), strand (positive or negative), ARE pattern and keywords. Users can also specify the size of the upstream/promoter regions (5 to 30 kb) from transcription start site to access the AREs located in those specific regions. Conclusion: ZFARED will be useful in the investigation of the Keap1-Nrf2-ARE pathway and its gene regulation. ZFARED is freely available at http://zfared.buc.edu.in/.

Swelling, reductive stress, and cell death during chemical hypoxia in hepatocytes

1989 ◽  
Vol 257 (2) ◽  
pp. C347-C354 ◽  
Author(s):  
G. J. Gores ◽  
C. E. Flarsheim ◽  
T. L. Dawson ◽  
A. L. Nieminen ◽  
B. Herman ◽  
...  
Keyword(s):  
Cell Injury ◽  
Rat Hepatocytes ◽  
Iodoacetic Acid ◽  
Cell Killing ◽  
Cell Swelling ◽  
Reductive Stress ◽  
Chemical Hypoxia ◽  
Hydroperoxide Formation ◽  
Bleb Formation ◽  
The Relationship

In rat hepatocytes, we examined the relationship between cell volume, bleb formation, and loss of cell viability during chemical hypoxia with KCN plus iodoacetic acid. In hypotonic media (150-200 mosmol/kgH2O), cells swelled to a greater extent during chemical hypoxia than in isotonic media, but rates of cell killing were identical. Sucrose (300 mM) added to isotonic media prevented early cell swelling but actually accelerated cell killing. In contrast, mannitol (300 mM) improved cell survival but did not prevent cell swelling. Bleb formation occurred regardless of buffer tonicity. The antioxidants desferrioxamine and cyanidanol but not superoxide dismutase +/- catalase delayed lethal cell injury. Cell killing was greater during aerobic compared with anaerobic chemical hypoxia. Hydroperoxide formation was measured using a dichlorofluorescin assay and was accelerated during aerobic but not anaerobic chemical hypoxia. The results indicate that cell swelling is not the driving force for bleb formation or lethal cell injury. We conclude that “reductive stress” caused by respiratory inhibition favors formation of toxic oxygen species and may contribute to lethal cell injury during intermittent or incomplete oxygen deprivation.

scholarly journals Nrf2 Is an Attractive Therapeutic Target for Retinal Diseases

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yasuhiro Nakagami
Keyword(s):  
Oxidative Stress ◽  
Neuronal Degeneration ◽  
Antioxidant Response ◽  
Related Factor ◽  
Retinal Diseases ◽  
Age Related ◽  
Nrf2 Signaling Pathway ◽  
Genes Encoding ◽  
Antioxidant Response Elements ◽  
Nrf2 Activator

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a redox-sensitive transcription factor that binds to antioxidant response elements located in the promoter region of genes encoding many antioxidant enzymes and phase II detoxifying enzymes. Activation of Nrf2 functions is one of the critical defensive mechanisms against oxidative stress in many species. The retina is constantly exposed to reactive oxygen species, and oxidative stress is a major contributor to age-related macular diseases. Moreover, the resulting inflammation and neuronal degeneration are also related to other retinal diseases. The well-known Nrf2 activators, bardoxolone methyl and its derivatives, have been the subject of a number of clinical trials, including those aimed at treating chronic kidney disease, pulmonary arterial hypertension, and mitochondrial myopathies. Recent studies suggest that Nrf2 activation protects the retina from retinal diseases. In particular, this is supported by the finding that Nrf2 knockout mice display age-related retinal degeneration. Moreover, the concept has been validated by the efficacy of Nrf2 activators in a number of retinal pathological models. We have also recently succeeded in generating a novel Nrf2 activator, RS9, using a biotransformation technique. This review discusses current links between retinal diseases and Nrf2 and the possibility of treating retinal diseases by activating the Nrf2 signaling pathway.

Abstract 218: Chemical Induced Reductive Stress Causes Cardiomyocyte Hypertrophy

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Sandeep B Shelar ◽  
Madhusudhanan Narasimhan ◽  
Gobinath Shanmugam ◽  
Neelu E Vargees ◽  
Ramasamy Sakthivel ◽  
...  
Keyword(s):  
Small Molecules ◽  
Cardiac Remodeling ◽  
Cell Types ◽  
Molecular Signature ◽  
Cardiomyocyte Hypertrophy ◽  
Reductive Stress ◽  
Vitro Model ◽  
C 50 ◽  
Sustained Activation

Background: Progressive accumulation of misfolded or unfolded proteins is a symbol of impaired proteostasis and proteotoxicity. Such a chronic proteotoxicity is amenable to cell types that are post mitotically matured with lack of further differentiation or proliferation. Our recent discovery using a mouse model of familial human cardiac disease displayed protuberant shift in the redox state towards reductive stress (RS) in association with accumulation of toxic protein aggregates. Further, sustained trans-activation of Nrf2/antioxidant signaling caused RS in the myopathy hearts. Accordingly, we hypothesized that whether profound activation of Nrf2/antioxidant signaling and subsequent RS may cause pathological remodeling in cardiomyocyte. The aim of this study was to investigate the effect of sustained pharmacological activation of Nrf2 on cardiac remodeling. Methods: HL1 cardiomyocytes were used as an in vitro model to study the RS-mediated cardiac remodeling. They were treated with 2-10 μM of potential Nrf2-inducers; sulforaphane (SF), di-methyl fumarate (DMF) and novel small molecules (C-38, C-50, C-63 and C-66) to establish RS by sustained activation of Nrf2/antioxidant signaling. Next, we investigated the implications of RS in cardiomyocyte remodeling by analyzing transcriptional and translational mechanisms using immunoblotting, qPCR, immunofluorescence, GSH and NADPH redox measurements in HL1 cells. Results: Dose dependent effects for individual small molecules including known Nrf2 inducers (SF and DMF) revealed distinct pro-reductive and reductive intracellular (i.e. reductive stress) environments. In fact, the obligatory activation of Nrf2 signaling was associated with significant upregulation of antioxidant enzymes and small molecular thiols including glutathione (GSH). Surprisingly, while pro-reductive condition in HL1 cells was subdued, the RS induced cardiomyocyte hypertrophy was evident from microscopic examination and molecular signature (increased expression of ANF and BNF) after 24-48 hrs of Nrf2 activation. Conclusion: In summary, the chemical induced sustained activation of Nrf2 leading to formation of reductive stress showed hypertrophic remodeling in HL1 cardiomyocytes.

scholarly journals Nestin regulates cellular redox homeostasis in lung cancer through the Keap1–Nrf2 feedback loop

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Jiancheng Wang ◽  
Qiying Lu ◽  
Jianye Cai ◽  
Yi Wang ◽  
Xiaofan Lai ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lung Cancer ◽  
Feedback Loop ◽  
Redox Homeostasis ◽  
Antioxidant Response ◽  
Cellular Redox ◽  
Anti Cancer ◽  
Oxidative Stress Status ◽  
Kelch Domain ◽  
Antioxidant Response Elements

Abstract Abnormal cancer antioxidant capacity is considered as a potential mechanism of tumor malignancy. Modulation of oxidative stress status is emerging as an anti-cancer treatment. Our previous studies have found that Nestin-knockdown cells were more sensitive to oxidative stress in non-small cell lung cancer (NSCLC). However, the molecular mechanism by which Nestin protects cells from oxidative damage remains unclear. Here, we identify a feedback loop between Nestin and Nrf2 maintaining the redox homeostasis. Mechanistically, the ESGE motif of Nestin interacts with the Kelch domain of Keap1 and competes with Nrf2 for Keap1 binding, leading to Nrf2 escaping from Keap1-mediated degradation, subsequently promoting antioxidant enzyme generation. Interestingly, we also map that the antioxidant response elements (AREs) in the Nestin promoter are responsible for its induction via Nrf2. Taken together, our results indicate that the Nestin–Keap1–Nrf2 axis regulates cellular redox homeostasis and confers oxidative stress resistance in NSCLC.

scholarly journals The role of nuclear factor-erythroid 2 related factor 2 (Nrf-2) in the protection against lung injury

2017 ◽  
Vol 312 (2) ◽  
pp. L155-L162 ◽  
Author(s):  
Hailin Zhao ◽  
Shiori Eguchi ◽  
Azeem Alam ◽  
Daqing Ma
Keyword(s):  
Lung Injury ◽  
Therapeutic Potential ◽  
Antioxidant Response ◽  
Protective Role ◽  
Chronic Obstructive ◽  
Related Factor ◽  
Nuclear Factor ◽  
Obstructive Pulmonary Disease ◽  
Antioxidant Response Elements

Nuclear factor-erythroid 2 related factor 2 (Nrf2) is a ubiquitous master transcription factor that upregulates antioxidant response elements (AREs)-mediated expression of antioxidant enzyme and cytoprotective proteins. Activation of Nrf2 has been shown to be protective against lung injury. In the lung, diverse stimuli including environmental oxidants, medicinal agents, and pathogens can activate Nrf2. Nrf2 translocates to the nucleus and binds to an ARE. Through transcriptional induction of ARE-bearing genes encoding antioxidant-detoxifying proteins, Nrf2 induces cellular rescue pathways against oxidative pulmonary injury, abnormal inflammatory and immune responses, and apoptosis. The Nrf2-antioxidant pathway has been shown to be important in the protection against various lung injuries including acute lung injury/acute respiratory distress syndrome and bronchopulmonary dysplasia, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, asthma, and allergy and was widely examined for new therapeutic targets. The present review explores the protective role of Nrf-2 against lung injury and the therapeutic potential in targeting Nrf-2.

scholarly journals Characterization of antioxidant properties and metabolite profile of Agave atrovirens extracts

2017 ◽  
Author(s):  
Victor Olvera-Garcia ◽  
Ana Belen Granado-Serrano ◽  
Mariona Jove ◽  
Anna Cassanye ◽  
Anaberta Cardador-Martinez ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
Crude Extract ◽  
Antioxidant Properties ◽  
Antioxidant Defense System ◽  
Metabolite Profile ◽  
Antioxidant Response ◽  
Nuclear Extracts ◽  
Antioxidant Response Elements ◽  
Cell Culture Assay ◽  
The One

Agave spp. is widely analyzed because several functional properties have been described. Some minor bioactive compounds such as polyphenols, saponins and Maillard compounds produced during extraction procedures have been reported to exert antioxidant properties. The objective of this study was to elucidate the antioxidant properties of three different Agave atrovirens extracts in a HepG2 cell culture assay. The three extracts analyzed mostly showed antioxidant properties with an increase in NRF2 content in nuclear extracts. However, a differential response was observed in the reduction of protein oxidative damage in the three extracts analyzed, the crude extract being the one that mainly induced a reduction in oxidative damage. Metabolomic analysis was performed to elucidate the potential molecules responsible for the antioxidant properties, where 2-amino-4-methylphenol could be the main candidate responsible for inducing the transcription of cellular antioxidant response elements. It could be concluded that crude extract of Agave atrovirens may increase the cellular antioxidant defense system, with a reduction in oxidative damage.

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