RESUMEN
Morphinone (MO) is an electrophilic metabolite of morphine that covalently binds to protein thiols via its α,ß-unsaturated carbonyl group, resulting in toxicity in vitro and in vivo. Our previous studies identified a variety of redox signaling pathways that are activated during electrophilic stress. Here, we examined in vitro activation of a signaling pathway involving Kelch-like ECH-associated protein 1 (Keap1) and nuclear factor erythroid 2-related factor 2 (Nrf2) in response to MO. Exposure of HepG2 cells to MO caused covalent modification of Keap1 thiols (evaluated using biotin-PEAC5-maleimide labeling) and nuclear translocation of Nrf2, thereby up-regulating downstream genes encoding ATP binding cassette subfamily C member 2, solute carrier family 7 member 11, glutamate-cysteine ligase catalytic subunit, glutamate-cysteine ligase modifier subunit, glutathione S-transferase alpha 1, and heme oxygenase 1. However, dihydromorphinone, a metabolite of morphine lacking the reactive C7-C8 double bond, had little effect on Nrf2 activation. These results suggest that covalent modification is crucial in the Keap1/Nrf2 pathway activation and that this pathway is a redox signaling-associated adaptive response to MO metabolism.
Asunto(s)
Glutamato-Cisteína Ligasa , Factor 2 Relacionado con NF-E2 , Glutamato-Cisteína Ligasa/genética , Glutamato-Cisteína Ligasa/metabolismo , Proteína 1 Asociada A ECH Tipo Kelch/genética , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Morfina/farmacología , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Compuestos de Sulfhidrilo , Humanos , Células Hep G2RESUMEN
Several indole derivatives have been disclosed by our research groups that have been collaborating for nearly 25 years. The results of our investigations led to a variety of molecules binding selectively to different pharmacological targets, specifically the type A γ-aminobutyric acid (GABAA) chloride channel, the translocator protein (TSPO), the murine double minute 2 (MDM2) protein, the A2B adenosine receptor (A2B AR) and the Kelch-like ECH-associated protein 1 (Keap1). Herein, we describe how these works were conceived and carried out thanks to the versatility of indole nucleus to be exploited in the design and synthesis of drug-like molecules.
Asunto(s)
Diazepam/análogos & derivados , Diseño de Fármacos , Moduladores del GABA/síntesis química , Indoles/síntesis química , Receptores de GABA-A/metabolismo , Animales , Diazepam/farmacología , Moduladores del GABA/farmacología , Humanos , Indoles/farmacología , Proteína 1 Asociada A ECH Tipo Kelch/agonistas , Proteína 1 Asociada A ECH Tipo Kelch/antagonistas & inhibidores , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Ligandos , Ratones , Unión Proteica , Proteínas Proto-Oncogénicas c-mdm2/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-mdm2/química , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Receptor de Adenosina A2B/química , Receptor de Adenosina A2B/metabolismo , Receptores de GABA/química , Receptores de GABA/metabolismo , Receptores de GABA-A/química , Relación Estructura-ActividadRESUMEN
BACKGROUND: Nuclear factor erythroid 2-related factor 2 (Nrf2) is involved in cell proliferation by promotion of metabolic activity. It is also the major regulator of antioxidants and has a pivotal role in tumor cell proliferation and resistance to chemotherapy. Accordingly, we investigated the role of Nrf2 in renal cell carcinoma (RCC). METHODS: In 50 patients who had metastatic RCC and received cytoreductive nephrectomy, we performed Nrf2 gene mutation analysis using targeted next-generation sequencing, as well as investigating a specific single nucleotide polymorphism (SNP; rs6721961) in the Nrf2 promoter region and Nrf2 protein expression. RESULTS: Targeted next-generation sequencing revealed that five tumors had SNPs of Nrf2 associated with amino acid sequence variation, while 11 tumors had SNPs of Kelch-like ECH-associated protein 1 gene, 35 had SNPs of von Hippel-Lindau gene, and none had SNPs of fumarate hydratase gene. The three genotypes of rs6721961 showed the following frequencies: 60% for C/C, 34% for C/A, and 6% for A/A. Nrf2 mutation and the C/A or A/A genotypes were significantly associated with increased Nrf2 protein expression (p = 0.0184 and p = 0.0005, respectively). When the primary tumor showed Nrf2 gene mutation, the C/A or A/A genotype, or elevated Nrf2 protein expression, the response of metastases to vascular endothelial growth factor-targeting therapy was significantly worse (p = 0.0142, p = 0.0018, and p < 0.0001, respectively), and overall survival was significantly reduced (p = 0.0343, p = 0.0421, and p < 0.0001, respectively). Elevated Nrf2 protein expression was also associated with shorter survival according to multivariate Cox proportional analysis. CONCLUSION: These findings suggest an associated between progression of RCC and Nrf2 signaling.
Asunto(s)
Carcinoma de Células Renales/cirugía , Neoplasias Renales/cirugía , Mutación , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Polimorfismo de Nucleótido Simple , Carcinoma de Células Renales/genética , Carcinoma de Células Renales/metabolismo , Procedimientos Quirúrgicos de Citorreducción , Femenino , Regulación Neoplásica de la Expresión Génica , Genotipo , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Neoplasias Renales/genética , Neoplasias Renales/metabolismo , Masculino , Regiones Promotoras Genéticas , Estudios Retrospectivos , Análisis de Secuencia de ADN , Transducción de Señal , Análisis de Supervivencia , Resultado del Tratamiento , Regulación hacia ArribaRESUMEN
In this study, we cloned the full-length cDNA of the Kelch-like ECH-associated protein 1 (Keap1) from the scallops Chlamys farreri (C. farreri). Sequences alignment and phylogenetic analysis showed that CfKeap1 was highly specific in the scallops, and the amino acid sequence identity value is closer to that in zebrafish Keap1b and Nothobranchius furzeri Keap1b than Keap1a. The highest transcription level of CfKeap1 expression was detected in the digestive glands. The gene expressions of CfKeap1, NF-E2-related nuclear factor 2 (Nrf2), Superoxide Dismutase (SOD), Catalase (CAT) and Glutathione Peroxidase (GPx) in digestive glands were evaluated by quantitative real-time PCR (qRT-PCR) after being exposed to benzo(a)pyrene (BaP) (0.25, 1and 4⯵g/L) for 15 days, which indicated that the activation of Nrf2 and Keap1 expression can be significantly induced under BaP exposure. RNA interference (RNAi) experiments were conducted to examine the expression profiles of CfKeap1, Nrf2, antioxidant genes (Cu/Zn-SOD, CAT and GPx), mitogen-activated protein kinase (MAPKs) and protein kinase C (PKC) signaling pathways key genes in digestive glands and gills when exposed to BaP. Results showed that the mRNA level of CfKeap1 was significantly decreased by 60.69% and59.485%. The changes of CfKeap1 and Nrf2 suggested that the enhancement of Keap1 expression stimulating Nrf2 degradation. Furthermore, the expression of antioxidant genes were consistent with the Nrf2 gene, which suggesting that Nrf2-Keap1 signaling pathway is required for the induction of antioxidant genes. Besides, the changes of PKC, c-Jun N-terminal kinase (JNK) and p38 genes expression suggested that PKC and MAPKs signaling pathways played a synergistic role with Nrf2-Keap1 signaling pathway in the anti-oxidative defense system of bivalve molluscs. In conclusion, these data demonstrated that Keap1 can sense nucleophilic or oxidative stress factors to regulate the Nrf2 signaling pathway together with Cul3-based E3 Ubiquitin Ligase (E3), and the Nrf2-Keap1 signaling pathway played an important role in modulating gene expression of antioxidant enzymes in bivalve mollusks.
Asunto(s)
Benzo(a)pireno/efectos adversos , Regulación de la Expresión Génica/inmunología , Inmunidad Innata/genética , Proteína 1 Asociada A ECH Tipo Kelch/genética , Proteína 1 Asociada A ECH Tipo Kelch/inmunología , Pectinidae/efectos de los fármacos , Contaminantes Químicos del Agua/efectos adversos , Secuencia de Aminoácidos , Animales , Perfilación de la Expresión Génica , Proteína 1 Asociada A ECH Tipo Kelch/química , Factor 2 Relacionado con NF-E2/química , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/inmunología , Pectinidae/genética , Pectinidae/inmunología , Filogenia , Alineación de Secuencia , Transducción de SeñalRESUMEN
BACKGROUND: Semi-synthetic oleanane triterpenoid antioxidant inflammation modulators (tpAIMs) are small molecules that interact with KEAP1 cysteine residue 151 (C151) and activate NRF2. Exploration of the structure-activity relationship between the tpAIMs and KEAP1 is limited by the predominantly hydrocarbon nature of the oleanane triterpenoid pentacyclic ring structure. Therefore, we used novel, chemically-tractable, synthetic antioxidant inflammation modulators (sAIMs) to probe the stereoselectivity of the ligand-protein interaction. METHODS: We measured several parameters of NRF2 activation to assess the potency of sAIM enantiomers with natural (tpAIM-like) 4(S),5(S),10(R) or unnatural 4(R),5(R),10(S) configurations. Additionally, we determined the crystal structure of the KEAP1 BTB domain in complex with two different sAIMs. RESULTS: We found that the potencies of sAIM enantiomers in the natural configuration were similar to those of the tpAIM, RTA 405. Strikingly, sAIM enantiomers in the unnatural configuration were 10- to 40-fold less potent than their natural counterparts. Crystallographic studies of sAIMs in complex with the KEAP1 BTB domain demonstrated that these ligands form a covalent bond with C151 and revealed the presence of additional hydrogen bonds, Van der Waals interactions, and pi-stacking interactions. CONCLUSIONS: Although KEAP1 C151 is required for NRF2 activation by tpAIMs and sAIMs, interactions with other KEAP1 residues are critical for the stereospecific recognition and potency of these ligands. GENERAL SIGNIFICANCE: This work demonstrates that reversible cyanoenone Michael acceptors, such as the tpAIMs and sAIMs, can be specifically tuned to regulate redox sensitive cysteine residues on key signaling molecules, an approach with significant promise for innovative drug development.
Asunto(s)
Antioxidantes/farmacología , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Ácido Oleanólico/química , Relación Estructura-Actividad Cuantitativa , Bibliotecas de Moléculas Pequeñas/farmacología , Animales , Antioxidantes/química , Sitios de Unión , Células HEK293 , Humanos , Proteína 1 Asociada A ECH Tipo Kelch/química , Ratones , Simulación del Acoplamiento Molecular , Factor 2 Relacionado con NF-E2/química , Bibliotecas de Moléculas Pequeñas/químicaRESUMEN
The multifunctional regulator nuclear factor erythroid 2-related factor (Nrf2) is considered not only as a cytoprotective factor regulating the expression of genes coding for anti-oxidant, anti-inflammatory and detoxifying proteins, but it is also a powerful modulator of species longevity. The vertebrate Nrf2 belongs to Cap 'n' Collar (Cnc) bZIP family of transcription factors and shares a high homology with SKN-1 from Caenorhabditis elegans or CncC found in Drosophila melanogaster. The major characteristics of Nrf2 are to some extent mimicked by Nrf2-dependent genes and their proteins including heme oxygenase-1 (HO-1), which besides removing toxic heme, produces biliverdin, iron ions and carbon monoxide. HO-1 and their products exert beneficial effects through the protection against oxidative injury, regulation of apoptosis, modulation of inflammation as well as contribution to angiogenesis. On the other hand, the disturbances in the proper HO-1 level are associated with the pathogenesis of some age-dependent disorders, including neurodegeneration, cancer or macular degeneration. This review summarizes our knowledge about Nrf2 and HO-1 across different phyla suggesting their conservative role as stress-protective and anti-aging factors.
Asunto(s)
Evolución Molecular , Hemo-Oxigenasa 1/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Estrés Oxidativo , Animales , Hemo-Oxigenasa 1/genética , Humanos , Longevidad , MicroARNs/metabolismo , Factor 2 Relacionado con NF-E2/genética , Complejo de la Endopetidasa Proteasomal/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Represoras/metabolismoRESUMEN
This study was performed to investigate the antioxidant activities of Nymphaea nouchali flower (NNF) extract and the underlying mechanism using RAW 264.7 cells. The presence of gallic acid, catechin, epicatechin, epigallocatechin, epicatechin gallate, caffeic acid, quercetin, and apigenin in the NNF was confirmed by high-performance liquid chromatography (HPLC). The extract had a very potent capacity to scavenge numerous free radicals. NNF extract was also able to prevent DNA damage and quench cellular reactive oxygen species (ROS) generation induced by tert-Butyl hydroperoxide (t-BHP) with no signs of toxicity. The NNF extract was able to augment the expression of both primary and phase II detoxifying enzyme, resulting in combat the oxidative stress. This is accomplished by phosphorylation of mitogen-activated protein kinase (MAP kinase) (p38 kinase and extracellular signal-regulated kinase (ERK)) followed by enhancing the nuclear translocation of the nuclear factor erythroid 2-related factor 2 (Nrf2). This attenuates cellular ROS generation and confers protection from cell death. Altogether, the results of current study revealed that Nymphaea nouchali flower could be a source of natural phytochemicals that could lead to the development of new therapeutic agents for preventing oxidative stress associated diseases and attenuating disease progression.
Asunto(s)
Antioxidantes/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Hemo-Oxigenasa 1/genética , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Nymphaea/química , Estrés Oxidativo/efectos de los fármacos , Extractos Vegetales/farmacología , Animales , Antioxidantes/química , Muerte Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Cromatografía Líquida de Alta Presión , Daño del ADN/efectos de los fármacos , Depuradores de Radicales Libres/farmacología , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Hemo-Oxigenasa 1/metabolismo , Humanos , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Ratones , Oxidación-Reducción/efectos de los fármacos , Fosforilación , Extractos Vegetales/química , terc-Butilhidroperóxido/farmacologíaRESUMEN
Therapeutic efficacy of cisplatin-based chemotherapy for advanced-stage urothelial carcinoma (UC) is limited by drug resistance. The nuclear factor (erythroid-derived 2)-like 2 (NRF2) pathway is a major regulator of cytoprotective responses. We investigated its involvement in cisplatin resistance in long-term cisplatin treated UC cell lines (LTTs). Expression of NRF2 pathway components and targets was evaluated by qRT-PCR and western blotting in LTT sublines from four different parental cells. NRF2 transcriptional activity was determined by reporter assays and total glutathione (GSH) was quantified enzymatically. Effects of siRNA-mediated NRF2 knockdown on chemosensitivity were analysed by viability assays, γH2AX immunofluorescence, and flow cytometry. Increased expression of NRF2, its positive regulator p62/SQSTM1, and elevated NRF2 activity was observed in 3/4 LTTs, which correlated with KEAP1 expression. Expression of cytoprotective enzymes and GSH concentration were upregulated in some LTTs. NRF2 knockdown resulted in downregulation of cytoprotective enzymes and resensitised 3/4 LTTs towards cisplatin as demonstrated by reduced IC50 values, increased γH2AX foci formation, and elevated number of apoptotic cells. In conclusion, while LTT lines displayed diversity in NRF2 activation, NRF2 signalling contributed to cisplatin resistance in LTT lines, albeit in diverse ways. Accordingly, inhibition of NRF2 can be used to resensitise UC cells to cisplatin, but responses in patients may likewise be variable.
Asunto(s)
Cisplatino/farmacología , Citoprotección/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , Factor 2 Relacionado con NF-E2/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias de la Vejiga Urinaria/metabolismo , Urotelio/metabolismo , Línea Celular Tumoral , Humanos , Neoplasias de la Vejiga Urinaria/patología , Urotelio/patologíaRESUMEN
p70 ribosomal S6 kinase 1 (S6K1) is an important serine/threonine kinase and downstream target of the mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway. PF-4708671 is a specific inhibitor of S6K1, and prevents S6K1-mediated phosphorylation of the S6 protein. PF-4708671 treatment often leads to apoptotic cell death. However, the protective mechanism against PF-4708671-induced cell death has not been elucidated. The nuclear factor erythroid 2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) pathway is essential for protecting cells against oxidative stress. p62, an adaptor protein in the autophagic process, enhances Nrf2 activation through the impairment of Keap1 activity. In this study, we showed that PF-4708671 induces autophagic Keap1 degradation-mediated Nrf2 activation in p62-dependent manner. Furthermore, p62-dependent Nrf2 activation plays a crucial role in protecting cells from PF-4708671-mediated apoptosis.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas del Citoesqueleto/metabolismo , Proteínas de Choque Térmico/metabolismo , Imidazoles/farmacología , Factor 2 Relacionado con NF-E2/metabolismo , Piperazinas/farmacología , Proteínas Quinasas S6 Ribosómicas 90-kDa/antagonistas & inhibidores , Proteínas Adaptadoras Transductoras de Señales/deficiencia , Proteínas Adaptadoras Transductoras de Señales/genética , Animales , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Autofagia/efectos de los fármacos , Autofagia/fisiología , Células Cultivadas , Proteínas del Citoesqueleto/genética , Células HeLa , Proteínas de Choque Térmico/deficiencia , Proteínas de Choque Térmico/genética , Humanos , Proteína 1 Asociada A ECH Tipo Kelch , Ratones , Inhibidores de Proteínas Quinasas/farmacología , Proteolisis/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Proteína Sequestosoma-1 , Transducción de Señal/efectos de los fármacosRESUMEN
Accumulating evidence suggests that dysregulation of the Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor E2-related factor 2 (Nrf2) pathway resulting in constitutively active Nrf2 and increased expression of cytoprotective Nrf2 target genes, has a pivotal role in cancer. Cancer cells are able to hijack the Keap1-Nrf2 system via multiple mechanisms leading to enhanced chemo- and radio-resistance and proliferation via metabolic reprogramming as well as inhibition of apoptosis. In this mini-review, we will describe the mechanisms leading to increased Nrf2 activity in cancer with a focus on the information achieved from large-scale multi-omics projects across various cancer types.
Asunto(s)
Regulación Neoplásica de la Expresión Génica , Péptidos y Proteínas de Señalización Intracelular/genética , Factor 2 Relacionado con NF-E2/genética , Neoplasias/genética , Apoptosis , Proliferación Celular , Resistencia a Antineoplásicos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de la radiación , Genómica , Humanos , Proteína 1 Asociada A ECH Tipo Kelch , Tolerancia a RadiaciónRESUMEN
Beyond specific limits of exposure, chemical entities can provoke deleterious effects in mammalian cells via direct interaction with critical macromolecules or by stimulating the accumulation of reactive oxygen species (ROS). In particular, these chemical and oxidative stresses can underpin adverse reactions to therapeutic drugs, which pose an unnecessary burden in the clinic and pharmaceutical industry. Novel pre-clinical testing strategies are required to identify, at an earlier stage in the development pathway, chemicals and drugs that are likely to provoke toxicity in humans. Mammalian cells can adapt to chemical and oxidative stress via the action of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2), which up-regulates the expression of numerous cell defence genes and has been shown to protect against a variety of chemical toxicities. Here, we provide a brief overview of the Nrf2 pathway and summarize novel experimental models that can be used to monitor changes in Nrf2 pathway activity and thus understand the functional consequences of such perturbations in the context of chemical and drug toxicity. We also provide an outlook on the potential value of monitoring Nrf2 activity for improving the pre-clinical identification of chemicals and drugs with toxic liability in humans.
Asunto(s)
Sustancias Macromoleculares/toxicidad , Factor 2 Relacionado con NF-E2/metabolismo , Estrés Oxidativo , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Especies Reactivas de Oxígeno/metabolismo , Transducción de SeñalRESUMEN
Cancer cells adapt their metabolism to their increased needs for energy and substrates for protein, lipid and nucleic acid synthesis. Nuclear erythroid factor 2-like 2 (Nrf2) pathway is usually activated in cancers and has been suggested to promote cancer cell survival mainly by inducing a large battery of cytoprotective genes. This mini review focuses on metabolic pathways, beyond cytoprotection, which can be directly or indirectly regulated by Nrf2 in cancer cells to affect their survival. The pentose phosphate pathway (PPP) is enhanced by Nrf2 in cancers and aids their growth. PPP has also been found to be up-regulated in non-cancer tissues and other pathways, such as de novo lipogenesis, have been found to be repressed after activation of the Nrf2 pathway. The importance of these Nrf2-regulated metabolic pathways in cancer compared with non-cancer state remains to be determined. Last but not least, the importance of context about Nrf2 and cancer is highlighted as the Nrf2 pathway may be activated in cancers but its pharmacological activators are useful in chemoprevention.
Asunto(s)
Péptidos y Proteínas de Señalización Intracelular/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Neoplasias/metabolismo , Vía de Pentosa Fosfato , Proliferación Celular , Supervivencia Celular , Regulación Neoplásica de la Expresión Génica , Humanos , Proteína 1 Asociada A ECH Tipo Kelch , Transducción de SeñalRESUMEN
The transcription factor nuclear factor erythroid-2-related factor 2 (Nrf2) up-regulates the expression of a range of cytoprotective enzymes with antioxidant response elements in their promoter regions and thus can protect cells against oxidative damage. Increasing Nrf2 activity has been proposed as a therapeutic intervention in a range of chronic neurodegenerative conditions and cancer chemoprevention. One of the main mechanisms by which Nrf2 is negatively regulated involves an interaction with the ubiquitination facilitator protein, Kelch-like ECH-associated protein 1 (Keap1) that facilitates degradation of Nrf2. Inhibition of this process underlies the mode of action of a broad group of compounds that increase Nrf2 activity. A number of natural products, including the isothiocyanate sulforaphane, up-regulate Nrf2 by interacting with Keap1 in a covalent manner to stall its activity. Recently, a number of peptide and small molecule inhibitors of the protein-protein interaction (PPI) between Keap1 and Nrf2 have been described. These classes of compound have contrasting modes of action at the molecular level and there is emerging evidence that their biological activities have similarities and differences. This review describes the various classes of PPI inhibitor that have been described in the literature and the biological evaluations that have been performed.
Asunto(s)
Péptidos y Proteínas de Señalización Intracelular/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Péptidos/farmacología , Bibliotecas de Moléculas Pequeñas/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Péptidos y Proteínas de Señalización Intracelular/química , Proteína 1 Asociada A ECH Tipo Kelch , Factor 2 Relacionado con NF-E2/química , Oxidación-Reducción , Unión Proteica/efectos de los fármacos , Transducción de Señal/efectos de los fármacosRESUMEN
The transcription factor nuclear factor-erythroid 2 p45-related factor 2 (Nrf2, with gene called NFE2L2) is a master regulator of the antioxidant response. In the last decade, interest has intensified in this research area as its importance in several physiological and pathological processes has become widely recognized; these include redox signalling and redox homoeostasis, drug metabolism and disposition, intermediary metabolism, cellular adaptation to stress, chemoprevention and chemoresistance, toxicity, inflammation, neurodegeneration, lipogenesis and aging. Regulation of Nrf2 is complex and although much attention has focussed on its repression by Kelch-like ECH-associated protein-1 (Keap1), recently it has become increasingly apparent that it is also controlled by cross-talk with other signalling pathways including the glycogen synthase kinase-3 (GSK-3)-ß-transducin repeat-containing protein (ß-TrCP) axis, ERAD (endoplasmic reticulum-associated degradation)-associated E3 ubiquitin-protein ligase (Hrd1, also called synoviolin), nuclear factor-kappa B (NF-κB), Notch and AMP kinase. Due to its beneficial role in several diseases, Nrf2 has become a major therapeutic target, with novel natural, synthetic and targeted small molecules currently under investigation to modulate the pathway and in clinical trials.
Asunto(s)
Péptidos y Proteínas de Señalización Intracelular/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Animales , Congresos como Asunto , Homeostasis , Humanos , Proteína 1 Asociada A ECH Tipo Kelch , Oxidación-Reducción , Transducción de SeñalRESUMEN
The nuclear erythroid 2-like 2 transcription factor (NRF2), is a major regulator of cellular redox balance. Although NRF2 activation is generally regarded as beneficial to human health, recent studies have identified that sustained NRF2 activation is over-represented in many cancers. This raises the question regarding the role of NRF2 activation in the development and progression of those cancers. This review focuses on the mechanisms and the effects of NRF2 activation in two hereditary cancer predisposition syndromes: hereditary leiomyomatosis and renal cell cancer (HLRCC) and hereditary tyrosinemia type 1 (HT1). Because the cancer initiating mutations in these hereditary syndromes are well defined, they offer a unique opportunity to explore the roles of NRF2 activation in the early stages of carcinogenesis. Over the years, a variety of approaches have been utilized to study the biology of HLRCC and HT1. In HLRCC, in vitro studies have demonstrated the importance of NRF2 activation in sustaining cancer cell proliferation. In the mouse model of HT1 however, NRF2 activation seems to protect cells from malignant transformation. In both HT1 and HLRCC, NRF2 activation promotes the clearance of electrophilic metabolites, enabling cells to survive cancer-initiating mutations. Biological insights gained from the hereditary syndromes' studies may shed light on to the roles of NRF2 activation in sporadic tumours.
Asunto(s)
Leiomiomatosis/genética , Factor 2 Relacionado con NF-E2/genética , Neoplasias Cutáneas/genética , Tirosinemias/genética , Neoplasias Uterinas/genética , Proliferación Celular , Regulación de la Expresión Génica , Humanos , Mutación , Síndromes Neoplásicos HereditariosRESUMEN
Nrf2 (nuclear factor erytheroid-derived-2-like 2) transcriptional programmes are activated by a variety of cellular stress conditions to maintain cellular homoeostasis. Under non-stress conditions, Nrf2 is under tight regulation by the ubiquitin proteasome system (UPS). Detailed mechanistic investigations have shown the Kelch-like ECH-associated protein 1 (Keap1)-cullin3 (Cul3)-ring-box1 (Rbx1) E3-ligase to be the primary Nrf2 regulatory system. Recently, both beta-transducin repeat-containing E3 ubiquitin protein ligase (ß-TrCP) and E3 ubiquitin-protein ligase synoviolin (Hrd1) have been identified as novel E3 ubiquitin ligases that negatively regulate Nrf2 through Keap1-independent mechanisms. In addition to UPS-mediated regulation of Nrf2, investigations have revealed a cross-talk between Nrf2 and the autophagic pathway resulting in activation of Nrf2 in a non-canonical manner. In addition to regulation at the protein level, Nrf2 was recently shown to be regulated at the transcriptional level by oncogenic K-rat sarcoma (Ras). A consequence of these differential regulatory mechanisms is the dual role of Nrf2 in cancer: the canonical, protective role and the non-canonical 'dark-side' of Nrf2. Based on the protective role of Nrf2, a vast effort has been dedicated towards identifying novel chemical inducers of Nrf2 for the purpose of chemoprevention. On the other hand, upon malignant transformation, some cancer cells have a constitutively high level of Nrf2 offering a growth advantage, as well as rendering cancer cells resistant to chemotherapeutics. This discovery has led to a new paradigm in cancer treatment; the initially counterintuitive use of Nrf2 inhibitors as adjuvants in chemotherapy. Herein, we will discuss the mechanisms of Nrf2 regulation and how this detailed molecular understanding can be leveraged to develop Nrf2 modulators to prevent diseases, mitigate disease progression or overcome chemoresistance.
Asunto(s)
Regulación Neoplásica de la Expresión Génica , Factor 2 Relacionado con NF-E2/genética , Neoplasias/genética , Animales , Autofagia , Resistencia a Antineoplásicos , Humanos , Factor 2 Relacionado con NF-E2/metabolismo , Neoplasias/metabolismo , Oxidación-Reducción , Proteínas Proto-Oncogénicas p21(ras)/metabolismoRESUMEN
In most tissues, cells are exposed to frequent changes in levels of oxidative stress and inflammation. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and nuclear factor-κB (NF-κB) are the two key transcription factors that regulate cellular responses to oxidative stress and inflammation respectively. Pharmacological and genetic studies suggest that there is functional cross-talk between these two important pathways. The absence of Nrf2 can exacerbate NF-κB activity leading to increased cytokine production, whereas NF-κB can modulate Nrf2 transcription and activity, having both positive and negative effects on the target gene expression. This review focuses on the potentially complex molecular mechanisms that link the Nrf2 and NF-κB pathways and the importance of designing more effective therapeutic strategies to prevent or treat a broad range of neurological disorders.
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Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , FN-kappa B/metabolismo , Enfermedades del Sistema Nervioso/metabolismo , Animales , Citocinas/metabolismo , Regulación de la Expresión Génica , Humanos , Enfermedades del Sistema Nervioso/tratamiento farmacológico , Enfermedades del Sistema Nervioso/genética , Estrés Oxidativo , Transducción de SeñalRESUMEN
Taurine is ubiquitously distributed in mammalian tissues, with the highest levels in the brain, heart, and leukocytes. Taurine reacts with hypochlorous acid (HOCl) to produce taurine chloramine (Tau-Cl) via the myeloperoxidase (MPO) system. In this study, we elucidated the antioxidative and protective effects of Tau-Cl in astrocytes. Tau-Cl increased the expression and nuclear translocation of nuclear factor E2-related factor (Nrf2) and the expression of Nrf2-regulated antioxidant genes, including heme oxygenase 1 (HO-1). Nrf2 activity is negatively regulated by Kelch-like ECH-associated protein 1 (Keap1). Tau-Cl decreased the level of the reduced thiol groups of Keap1, resulting in the disruption of the Keap1-Nrf2 complex. Consequently, Tau-Cl rescued the H2O2-induced cell death by enhancing HO-1 expression and suppressing reactive oxygen species. In conclusion, Tau-Cl confers protective effects in astrocytes by disrupting the Keap1-Nrf2 complex, thereby promoting Nrf2 translocation to the nucleus, wherein it binds to the antioxidant response element (ARE) and accelerates the transcription of antioxidant genes. Therefore, in astrocytes, the activation of the Keap1-Nrf2-ARE pathway by Tau-Cl may increase antioxidants and anti-inflammatory mediators as well as other cytoprotective proteins, conferring protection against brain infection and injury.
RESUMEN
One of the most important factors involved in the response to oxidative stress (OS) is the nuclear factor erythroid 2-related factor 2 (Nrf2), which regulates the expression of components such as antioxidative stress proteins and enzymes. Under normal conditions, Kelch-like ECH-associated protein 1 (Keap1) keeps Nrf2 in the cytoplasm, thus preventing its translocation to the nucleus and inhibiting its role. It has been established that Nrf2 has a dual function; on the one hand, it promotes angiogenesis and cancer cell metastasis while causing resistance to drugs and chemotherapy. On the other hand, Nrf2 increases expression and proliferation of glutathione to protect cells against OS. p53 is a tumour suppressor that activates the apoptosis pathway in aging and cancer cells in addition to stimulating the glutaminolysis and antioxidant pathways. Cancer cells use the antioxidant ability of p53 against OS. Therefore, in the present study, we discussed function of Nrf2 and p53 in breast cancer (BC) cells to elucidate their role in protection or destruction of cancer cells as well as their drug resistance or antioxidant properties.
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Antioxidantes , Neoplasias de la Mama , Humanos , Femenino , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Antioxidantes/metabolismo , Antioxidantes/farmacología , Proteína p53 Supresora de Tumor/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Estrés OxidativoRESUMEN
Itaconate is a metabolite produced to counteract and resolve pro-inflammatory responses when macrophages are challenged with intracellular or extracellular stimuli. In the present study, we have observed that dimethyl itaconate (DMI) inhibits melanogenesis in B16F10 cells. DMI inhibits microphthalmia-associated transcription factor (MITF) and downregulates the expression of MITF target genes, such as tyrosinase (TYR), tyrosinase-related protein 1 (TRP-1), and tyrosinase-related protein 2 (TRP-2). DMI also decreases the level of melanocortin 1 receptor (MC1R) and the production of α-melanocyte stimulating hormone (α-MSH), resulting in the inhibition of extracellular signal-regulated kinase 1/2 (ERK1/2) and MITF activities. The structure-activity relationship (SAR) study illustrates that the α,ß-unsaturated carbonyl moiety in DMI, a moiety required to target KELCH-like ECH-associated protein 1 (KEAP1) to activate NF-E2-related factor 2 (NRF2), is necessary to inhibit melanogenesis and knocking down Nrf2 attenuates the inhibition of melanogenesis by DMI. Together, our study reveals that the MC1R-ERK1/2-MITF axis regulated by the KEAP1-NRF2 pathway is the molecular target responsible for the inhibition of melanogenesis by DMI.