scholarly journals Role of the Nrf2-ARE Pathway in Liver Diseases

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Sang Mi Shin ◽  
Ji Hye Yang ◽  
Sung Hwan Ki

The liver is a central organ that performs a wide range of functions such as detoxification and metabolic homeostasis. Since it is a metabolically active organ, liver is particularly susceptible to oxidative stress. It is well documented that liver diseases including hepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma are highly associated with antioxidant capacity. NF-E2-related factor-2 (Nrf2) is an essential transcription factor that regulates an array of detoxifying and antioxidant defense genes expression in the liver. It is activated in response to electrophiles and induces its target genes by binding to the antioxidant response element (ARE). Therefore, the roles of the Nrf2-ARE pathway in liver diseases have been extensively investigated. Studies from several animal models suggest that the Nrf2-ARE pathway collectively exhibits diverse biological functions against viral hepatitis, alcoholic and nonalcoholic liver disease, fibrosis, and cancer via target gene expression. In this review, we will discuss the role of the Nrf2-ARE pathway in liver pathophysiology and the potential application of Nrf2 as a therapeutic target to prevent and treat liver diseases.

2018 ◽  
Vol 17 (5) ◽  
pp. 325-337 ◽  
Author(s):  
Hojjat Borna ◽  
Kasim Assadoulahei ◽  
Gholamhossein Riazi ◽  
Asghar Beigi Harchegani ◽  
Alireza Shahriary

Background & Objective: Neurodegenrative diseases are among the most widespread lifethreatening disorders around the world in elderly ages. The common feature of a group of neurodegenerative disorders, called tauopathies, is an accumulation of microtubule associated protein tau inside the neurons. The exact mechanism underlying tauopathies is not well-understood but several factors such as traumatic brain injuries and genetics are considered as potential risk factors. Although tau protein is well-known for its key role in stabilizing and organization of axonal microtubule network, it bears a broad range of functions including DNA protection and participation in signaling pathways. Moreover, the flexible unfolded structure of tau facilitates modification of tau by a wide range of intracellular enzymes which in turn broadens tau function and interaction spectrum. The distinctive properties of tau protein concomitant with the crucial role of tau interaction partners in the progression of neurodegeneration suggest tau and its binding partners as potential drug targets for the treatment of neurodegenerative diseases. Conclusion: This review aims to give a detailed description of structure, functions and interactions of tau protein in order to provide insight into potential therapeutic targets for treatment of tauopathies.


2021 ◽  
Vol 22 (5) ◽  
pp. 2754
Author(s):  
Naila Qayyum ◽  
Muhammad Haseeb ◽  
Moon Suk Kim ◽  
Sangdun Choi

Thioredoxin-interacting protein (TXNIP), widely known as thioredoxin-binding protein 2 (TBP2), is a major binding mediator in the thioredoxin (TXN) antioxidant system, which involves a reduction-oxidation (redox) signaling complex and is pivotal for the pathophysiology of some diseases. TXNIP increases reactive oxygen species production and oxidative stress and thereby contributes to apoptosis. Recent studies indicate an evolving role of TXNIP in the pathogenesis of complex diseases such as metabolic disorders, neurological disorders, and inflammatory illnesses. In addition, TXNIP has gained significant attention due to its wide range of functions in energy metabolism, insulin sensitivity, improved insulin secretion, and also in the regulation of glucose and tumor suppressor activities in various cancers. This review aims to highlight the roles of TXNIP in the field of diabetology, neurodegenerative diseases, and inflammation. TXNIP is found to be a promising novel therapeutic target in the current review, not only in the aforementioned diseases but also in prolonged microvascular and macrovascular diseases. Therefore, TXNIP inhibitors hold promise for preventing the growing incidence of complications in relevant diseases.


2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Daisuke Kase ◽  
Keiji Imoto

Hyperpolarization-activated and cyclic nucleotide-gated (HCN) channels were first reported in heart cells and are recently known to be involved in a variety of neural functions in healthy and diseased brains. HCN channels generate inward currents when the membrane potential is hyperpolarized. Voltage dependence of HCN channels is regulated by intracellular signaling cascades, which contain cyclic AMP, PIP2, and TRIP8b. In addition, voltage-gated potassium channels have a strong influence on HCN channel activity. Because of these funny features, HCN channel currents, previously called funny currents, can have a wide range of functions that are determined by a delicate balance of modulatory factors. These multifaceted features also make it difficult to predict and elucidate the functional role of HCN channels in actual neurons. In this paper, we focus on the impacts of HCN channels on neural activity. The functions of HCN channels reported previously will be summarized, and their mechanisms will be explained by using numerical simulation of simplified model neurons.


2018 ◽  
Vol 9 (10) ◽  
pp. 5198-5208 ◽  
Author(s):  
Hanjie Yu ◽  
Yaogang Zhong ◽  
Zhiwei Zhang ◽  
Xiawei Liu ◽  
Kun Zhang ◽  
...  

The bovine milk proteins have a wide range of functions, but the role of the attached glycans in their biological functions has not been fully understood yet.


2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Chitra Basu ◽  
Runa Sur

Hydrogen peroxide (H2O2) mediated oxidative stress leading to hepatocyte apoptosis plays a pivotal role in the pathophysiology of several chronic liver diseases. This study demonstrates that S-allyl cysteine (SAC) renders cytoprotective effects on H2O2 induced oxidative damage and apoptosis in HepG2 cells. Cell viability assay showed that SAC protected HepG2 cells from H2O2 induced cytotoxicity. Further, SAC treatment dose dependently inhibited H2O2 induced apoptosis via decreasing the Bax/Bcl-2 ratio, restoring mitochondrial membrane potential (∆Ψm), inhibiting mitochondrial cytochrome c release, and inhibiting proteolytic cleavage of caspase-3. SAC protected cells from H2O2 induced oxidative damage by inhibiting reactive oxygen species accumulation and lipid peroxidation. The mechanism underlying the antiapoptotic and antioxidative role of SAC is the induction of the heme oxygenase-1 (HO-1) gene in an NF-E2-related factor-2 (Nrf-2) and Akt dependent manner. Specifically SAC was found to induce the phosphorylation of Akt and enhance the nuclear localization of Nrf-2 in cells. Our results were further confirmed by specific HO-1 gene knockdown studies which clearly demonstrated that HO-1 induction indeed played a key role in SAC mediated inhibition of apoptosis and ROS production in HepG2 cells, thus suggesting a hepatoprotective role of SAC in combating oxidative stress mediated liver diseases.


2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Yi Zou ◽  
Jun Wang ◽  
Jian Peng ◽  
Hongkui Wei

Oregano essential oil (OEO) has long been used to improve the health of animals, particularly their intestinal health. The health benefits of OEO are generally attributed to antioxidative actions, but the mechanisms remain unclear. Here, we investigate the antioxidative effects of OEO and their underlying molecular mechanisms in porcine small intestinal epithelial (IPEC-J2) cells. We found that OEO treatment prior to hydrogen peroxide (H2O2) exposure increased cell viability and prevented lactate dehydrogenase (LDH) release into the medium. H2O2-induced reactive oxygen species (ROS) and malondialdehyde (MDA) were remarkably suppressed by OEO. OEO dose-dependently increased mRNA and protein levels of the nuclear factor-erythroid 2-related factor-2 (Nrf2) target genes Cu/Zn-superoxide dismutase (SOD1) and g-glutamylcysteine ligase (GCLC, GLCM), as well as intracellular concentrations of SOD1 and glutathione. OEO also increased intranuclear expression of Nrf2 and the activity of an antioxidant response element reporter plasmid in IPEC-J2 cells. The OEO-induced expression of Nrf2-regulated genes and increased SOD1 and glutathione concentrations in IPEC-J2 cells were reduced by Nrf2 small interfering (si) RNAs, counteracting the protective effects of OEO against oxidative stress in IPEC-J2 cells. Our results suggest that OEO protects against H2O2-induced IPEC-J2 cell damage by inducing Nrf2 and related antioxidant enzymes.


2021 ◽  
Vol 22 (13) ◽  
pp. 7152
Author(s):  
Yaqi Hao ◽  
Xiumei Zong ◽  
Pan Ren ◽  
Yuqi Qian ◽  
Aigen Fu

The basic helix-loop-helix (bHLH) transcription factor family is one of the largest transcription factor gene families in Arabidopsis thaliana, and contains a bHLH motif that is highly conserved throughout eukaryotic organisms. Members of this family have two conserved motifs, a basic DNA binding region and a helix-loop-helix (HLH) region. These proteins containing bHLH domain usually act as homo- or heterodimers to regulate the expression of their target genes, which are involved in many physiological processes and have a broad range of functions in biosynthesis, metabolism and transduction of plant hormones. Although there are a number of articles on different aspects to provide detailed information on this family in plants, an overall summary is not available. In this review, we summarize various aspects of related studies that provide an overview of insights into the pleiotropic regulatory roles of these transcription factors in plant growth and development, stress response, biochemical functions and the web of signaling networks. We then provide an overview of the functional profile of the bHLH family and the regulatory mechanisms of other proteins.


2007 ◽  
Vol 27 (17) ◽  
pp. 6195-6208 ◽  
Author(s):  
Min Kyung Cho ◽  
Won Dong Kim ◽  
Sung Hwan Ki ◽  
Jong-Ik Hwang ◽  
Sangdun Choi ◽  
...  

ABSTRACT Gα12 and Gα13 function as molecular regulators responding to extracellular stimuli. NF-E2-related factor 2 (Nrf2) is involved in a protective adaptive response to oxidative stress. This study investigated the regulation of Nrf2 by Gα12 and Gα13. A deficiency of Gα12, but not of Gα13, enhanced Nrf2 activity and target gene transactivation in embryo fibroblasts. In mice, Gα12 knockout activated Nrf2 and thereby facilitated heme catabolism to bilirubin and its glucuronosyl conjugations. An oligonucleotide microarray demonstrated the transactivation of Nrf2 target genes by Gα12 gene knockout. Gα12 deficiency reduced Jun N-terminal protein kinase (JNK)-dependent Nrf2 ubiquitination required for proteasomal degradation, and so did Gα13 deficiency. The absence of Gα12, but not of Gα13, increased protein kinase C δ (PKC δ) activation and the PKC δ-mediated serine phosphorylation of Nrf2. Gα13 gene knockout or knockdown abrogated the Nrf2 phosphorylation induced by Gα12 deficiency, suggesting that relief from Gα12 repression leads to the Gα13-mediated activation of Nrf2. Constitutive activation of Gα13 promoted Nrf2 activity and target gene induction via Rho-mediated PKC δ activation, corroborating positive regulation by Gα13. In summary, Gα12 and Gα13 transmit a JNK-dependent signal for Nrf2 ubiquitination, whereas Gα13 regulates Rho-PKC δ-mediated Nrf2 phosphorylation, which is negatively balanced by Gα12.


2017 ◽  
Vol 312 (2) ◽  
pp. L155-L162 ◽  
Author(s):  
Hailin Zhao ◽  
Shiori Eguchi ◽  
Azeem Alam ◽  
Daqing Ma

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.


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