Nuclear factor E2-related factor 2 (NRF2) plays an important role in redox metabolism and antioxidant defense. Under normal conditions, NRF2 proteins are maintained at very low levels because of their ubiquitination and proteasomal degradation via binding to the kelch-like ECH associated protein 1 (KEAP1)-E3 ubiquitin ligase complex. However, oxidative and/or electrophilic stresses disrupt the KEAP1-NRF2 interaction, which leads to the accumulation and transactivation of NRF2. During recent decades, a growing body of evidence suggests that NRF2 is frequently activated in many types of cancer by multiple mechanisms, including the genetic mutations in the KEAP1-NRF2 pathway. This suggested that NRF2 inhibition is a promising strategy for cancer therapy. Recently, several NRF2 inhibitors have been reported with anti-tumor efficacy. Here, we review the mechanisms whereby NRF2 is dysregulated in cancer and its contribution to the tumor development and radiochemoresistance. In addition, among the NRF2 inhibitors reported so far, we summarize and discuss repurposed NRF2 inhibitors with their potential mechanisms and provide new insights to develop selective NRF2 inhibitors.
Metabolism ; NF-E2-Related Factor 2 ; Oxidation-Reduction ; Transcriptional Activation ; Ubiquitin ; Ubiquitination

Wound healing is one of the common pathophysiological processes in the body. How to improve the condition of wound healing to promote rapid wound healing has always been a hotspot in research. Oxidative stress is one of the important factors affecting wound healing. Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a classic antioxidant stress factor as well as a factor with great potential in facilitating wound healing. The activation of Nrf2 can regulate the downstream antioxidant stress elements and play roles of anti-apoptosis and cell homeostasis maintaining, which improves wound healing environment and promotes wound repair. This paper summarized the common agonists and inhibitors of Nrf2 and reviewed the roles of Nrf2 in promoting skin wound healing including diabetic ulcers, radiation injury, and ischemia-reperfusion injury, etc.
Antioxidants/pharmacology* ; NF-E2-Related Factor 2/metabolism* ; Oxidative Stress ; Wound Healing/physiology*

This study aims to investigate the detoxification effects of different processing methods on the cardiotoxicity induced by radix Tripterygium wilfordii, and preliminarily explore the detoxification mechanism via the nuclear factor E2-related factor 2(Nrf2)/heme oxygenase 1(HO-1) pathway. The raw and processed products [stir-fried product, product stir-fried with Lysimachiae Herba(JQC), product stir-fried with Phaseoli Radiati Semen(LD), product stir-fried with Paeoniae Radix Alba(BS), product stir-fried with Glycyrrhizae Radix et Rhizoma(GC), and product stir-fried with vinegar(CZ)] of radix T. wilfordii were administrated to mice by gavage at a dose of 2 g·kg~(-1)(based on crude drugs) for 28 days. Twenty-four hours after the last administration, we measured the serum biochemical indexes of mice to evaluate the detoxification effect. Furthermore, we determined the expression of key proteins of Nrf2/HO-1 pathway in mouse heart tissue by Western blot and some oxidation/antioxidation-related indexes by corresponding kits to explore the detoxification mechanism. The administration of the raw product elevated the levels of serum creatine kinase, lactate dehydrogenase, and malondialdehyde, a product of cardiac lipid peroxidation(P<0.01), down-regulated the protein levels of Nrf2 and HO-1(P<0.01), and reduced the levels of total superoxide dismutase, glutathione, glutathione peroxidase, and glutathione S-transferase(P<0.01). However, after the administration of the products stir-fried with JQC, LD, BS, GC, and CZ, the abnormalities of the above indexes induced by the raw product were recovered(P<0.05 or P<0.01). In particular, the product stir-fried with JQC showed the best performance. Taken all together, the cardiotoxicity induced by radix T. wilfordii could be attenuated by stir-frying with JQC, LD, BS, GC, and CZ, and the stir-frying with JQC showed the best detoxification effect. The mechanism might be associated with the cardiac antioxidant defense and oxidative damage mitigation mediated by the up-regulated Nrf2.
Animals ; Antioxidants/pharmacology* ; Cardiotoxicity ; Mice ; NF-E2-Related Factor 2/metabolism* ; Oxidative Stress ; Tripterygium

The imbalance of redox homeostasis is a major characteristic of aging and contributes to the pathogenesis of various aging-related diseases. As a regulatory hub of redox homeostasis, nuclear factor erythroid 2-related factor 2 (NRF2) can attenuate oxidative stress by activating the transcription of many antioxidant enzymes. China is the birthplace of traditional Chinese medicine (TCM) which has been wildly used as medicine for thousands of years. Recently, TCM as anti-aging medicine has attracted enormous attention. Focusing on the NRF2 signaling pathway, this paper summarizes the correlation between various anti-aging TCM and the NRF2 signaling, and discusses the common key mechanisms by which TCM slows the aging process by targeting the NRF2 signaling network.
Medicine, Chinese Traditional ; NF-E2-Related Factor 2/metabolism* ; Oxidative Stress ; Signal Transduction

To investigate the protective effect and the potential mechanism of leonurine(Leo) against erastin-induced ferroptosis in human renal tubular epithelial cells(HK-2 cells), an in vitro erastin-induced ferroptosis model was constructed to detect the cell viability as well as the expressions of ferroptosis-related indexes and signaling pathway-related proteins. HK-2 cells were cultured in vitro, and the effects of Leo on the viability of HK-2 cells at 10, 20, 40, 60, 80 and 100 μmol·L~(-1) were examined by CCK-8 assay to determine the safe dose range of Leo administration. A ferroptosis cell model was induced by erastin, a common ferroptosis inducer, and the appropriate concentrations were screened. CCK-8 assay was used to detect the effects of Leo(20, 40, 80 μmol·L~(-1)) and positive drug ferrostatin-1(Fer-1, 1, 2 μmol·L~(-1)) on the viability of ferroptosis model cells, and the changes of cell morphology were observed by phase contrast microscopy. Then, the optimal concentration of Leo was obtained by Western blot for nuclear factor erythroid 2-related factor 2(Nrf2) activation, and transmission electron microscope was further used to detect the characteristic microscopic morphological changes during ferroptosis. Flow cytometry was performed to detect reactive oxygen species(ROS), and the level of glutathione(GSH) was measured using a GSH assay kit. The expressions of glutathione peroxidase 4(GPX4), p62, and heme oxygenase 1(HO-1) in each group were quantified by Western blot. RESULTS:: showed that Leo had no side effects on the viability of normal HK-2 cells in the concentration range of 10-100 μmol·L~(-1). The viability of HK-2 cells decreased as the concentration of erastin increased, and 5 μmol·L~(-1) erastin significantly induced ferroptosis in the cells. Compared with the model group, Leo dose-dependently increased cell via-bility and improved cell morphology, and 80 μmol·L~(-1) Leo promoted the translocation of Nrf2 from the cytoplasm to the nucleus. Further studies revealed that Leo remarkably alleviated the characteristic microstructural damage of ferroptosis cells caused by erastin, inhibited the release of intracellular ROS, elevated GSH and GPX4, promoted the nuclear translocation of Nrf2, and significantly upregulated the expression of p62 and HO-1 proteins. In conclusion, Leo exerted a protective effect on erastin-induced ferroptosis in HK-2 cells, which might be associated with its anti-oxidative stress by activating p62/Nrf2/HO-1 signaling pathway.
Humans ; Ferroptosis ; Reactive Oxygen Species/metabolism* ; NF-E2-Related Factor 2/metabolism* ; Sincalide/pharmacology* ; Signal Transduction ; Epithelial Cells/metabolism* ; Glutathione

The nuclear factor erythroid 2 related factor 2 (Nrf2) is a key protein of endogenous antioxidant defense systems in the body. In response to oxidative stress, Nrf2 translocates to nucleus and binds to antioxidant response elements (ARE), regulating the expression of a large amounts of antioxidant genes and maintaining a proper redox balance. The pathological processes of neurodegenerative diseases are associated with generation of reactive oxygen species, which cause oxidative stress. Oxidative stress plays a cardinal role in the onset and progression of neurodegenerative diseases. Nrf2-inducer compounds can reduce oxidant stress and have shown therapeutic efficacy in many neurodegenerative disease models. How to activate the Nrf2 signaling pathway effectively has been received much attention. Here we provided an overview of specific mechanism of Nrf2-ARE pathway and the protective effects of Nrf2 in different neurodegenerative diseases, and summarized the Nrf2 activators recently in preclinical study.
Antioxidants ; physiology ; Humans ; NF-E2-Related Factor 2 ; physiology ; Neurodegenerative Diseases ; metabolism ; Oxidative Stress ; Reactive Oxygen Species ; metabolism ; Signal Transduction

Nrf2 is the key transcription factor mainly for regulating oxidative homeostasis and cytoprotective responses against oxidative stress. Nrf2/Keap1 pathway is one of the most important cellular defense mechanisms against endogenous or exogenous oxidative stress. With its activation, a wide range of stress-related genes is transactivated to restore the cellular homeostasis. Recent studies revealed that the aberrant activation of Nrf2 is related to the malignant progression, chemotherapeutic drug resistance and poor prognosis. Nrf2 plays a crucial role in cancer malignancy and chemotherapeutic resistance by controlling the intracellular redox homeostasis through the activation of cytoprotective antioxidant genes. Nrf2 inhibitor containing many natural products has been deemed as a novel therapeutic strategy for human malignancies. This article reviews the progress of studies of the Nrf2/Keap1 pathway, and its biological impact in solid malignancies and molecular mechanisms for causing Nrf2 hyperactivation in cancer cells. In conclusion, we summarized the deve-lopment of Nrf2 inhibitors in recent years, in the expectation of providing reference for further drug development and clinical studies.
Humans ; Kelch-Like ECH-Associated Protein 1/metabolism* ; NF-E2-Related Factor 2/metabolism* ; Neoplasms/genetics* ; Oxidation-Reduction ; Oxidative Stress

OBJECTIVE: To investigate the changes and roles of reactive oxygen species (ROS) and nuclear factor erythroid 2-related factor 2 (Nrf2) related antioxidases during erythroid development. METHODS: Flow cytometry was used to detect the sensibility of peripheral red blood cells of wild-type mice to a strong oxidant hydrogen peroxide (H₂O₂). Erythroid cells from different developmental stages in bone marrow (BM) were obtained using fluorescence-activated cell sorter and the ROS levels were detected by flow cytometry. RT-qPCR was used to detect the changes of expression levels of Nrf2 and related antioxidases in erythroid cells from different developmental stages in BM. The ROS levels of the peripheral blood and BM nucleated erythrocytes in Nrf2 knockout mice were further examined. The expression level of Nrf2 in erythroid precursors isolated from 14.5 d embryonic liver of wild-type mice during differentiation and culture in vitro was detected. RESULTS: In the peripheral blood of wild-type mice, the ROS level of reticulocytes and mature erythrocytes treated with H₂O₂ increased about 4 times and 7 times, respectively (P<0.01). In BM erythrocytes, the ROS level gradually decreased as the cells matured (r=0.85), while the expression level of Nrf2 and its related anti-oxidative genes increased (r=0.99). The ROS levels in peripheral blood erythrocytes and BM nucleated erythrocytes of Nrf2 knockout mice were significantly increased compared with wild-type mice (P<0.01). The expression of Nrf2 increased during the early erythroid development after embryonic liver cell sorting (P<0.01). CONCLUSION The expression levels of Nrf2 and its related factors vary during erythropoiesis. Nrf2 at physiological level plays an important antioxidant role during the erythroid development.
Animals ; Mice ; Hydrogen Peroxide ; Mice, Knockout ; NF-E2-Related Factor 2/metabolism* ; Oxidative Stress ; Reactive Oxygen Species/metabolism*

The present study analyzed the correlations between curcumin(Cur), nuclear factor E2 related factor 2(NRF2)-dimethylarginine dimethylaminohydrolase(DDAH)-asymmetric dimethylarginine(ADMA)-nitric oxide(NO) pathway, and endothelial-mesenchymal transition(EndMT) based on SD rats with cardiac fibrosis, and explored the effect and mechanism of Cur in resisting cardiac fibrosis to provide an in-depth theoretical basis for its clinical application in the treatment of heart failure. The cardiac fibrosis model was induced by subcutaneous injection of isoprenaline(Iso) in rats. Thirty-two rats were randomly divided into a control group, a model group, a low-dose Cur group(100 mg·kg~(-1)·d~(-1)), and a high-dose Cur group(200 mg·kg~(-1)·d~(-1)), with eight in each group. After 21 days of treatment, cardiac function was detected by echocardiography, degree of cardiac fibrosis by Masson staining, expression of CD31 and α-SMA by pathological staining, expression of VE-cadherin, vimentin, NRF2, and DDAH by Western blot, and ADMA level by HPLC. Compared with the model group, the Cur groups showed alleviated cardiac fibrosis, accompanied by increased CD31 and VE-cadherin expression and decreased α-SMA and vimentin expression, indicating relieved EndMT. Additionally, DDAH and NRF2 levels were elevated and ADMA and NO expression declined. Cur improves cardiac fibrosis by inhibiting EndMT presumedly through the NRF2-DDAH-ADMA-NO pathway.
Amidohydrolases/metabolism* ; Animals ; Curcumin ; Fibrosis ; NF-E2-Related Factor 2/genetics* ; Nitric Oxide/metabolism* ; Rats ; Rats, Sprague-Dawley

Aging ; Animals ; Galactose ; Kidney/metabolism* ; NF-E2-Related Factor 2/metabolism* ; Oxidative Stress ; Rats ; Rats, Sprague-Dawley ; Xanthophylls