The role of nuclear factor erythroid 2-related factor 2 (NRF2) in arsenic toxicity.

Arsenic, a naturally occurring toxic element, manifests in various chemical forms and is widespread in the environment. Exposure to arsenic is a well-established risk factor for an elevated incidence of various cancers and chronic diseases. The crux of arsenic-mediated toxicity lies in its ability to induce oxidative stress, characterized by an unsettling imbalance between oxidants and antioxidants, accompanied by the rampant generation of reactive oxygen species and free radicals. In response to this oxidative turmoil, cells deploy their defense mechanisms, prominently featuring the redox-sensitive transcription factor known as nuclear factor erythroid 2-related factor 2 (NRF2). NRF2 stands as a primary guardian against the oxidative harm wrought by arsenic. When oxidative stress activates NRF2, it orchestrates a symphony of downstream antioxidant genes, leading to the activation of pivotal antioxidant enzymes like glutathione-S-transferase, heme oxygenase-1, and NAD(P)H: quinone oxidoreductase 1. This comprehensive review embarks on the intricate and diverse ways by which various arsenicals influence the NRF2 antioxidant pathway and its downstream targets, shedding light on their roles in defending against arsenic exposure toxic effects. It offers valuable insights into targeting NRF2 as a strategy for safeguarding against or treating the harmful and carcinogenic consequences of arsenic exposure.

Identification and molecular mechanism of novel antioxidant peptide from fish sauce: A combined quantum chemistry and molecular simulation.

Fish sauce, derived from fermented fish, exhibits a notable antioxidant effect after a six-month fermentation process, and we propose that potential antioxidant peptides were present in the fish sauce. We isolated, purified, and identified potential bioactive antioxidant peptides by using fish sauce fermented for 6 months. Additionally, molecular simulation was employed to investigate the antioxidant action mechanism of these bioactive peptides. The molecular docking results revealed that FS4-1 (MHQLSKK), FS4-2 (VLDNSPER), FS4-3 (MNPPAASIK), FS6-1(VLKQAAAGR), and FS6-2 (SPDVSPRR), could dock with the Keap1 receptor. The primary force (Van der Waals' force and hydrogen bonds) and key sites (GLY509 and ALA510) of Keap1 binding to peptides were determined. The active center was located in the side chain of amino acid Met at positions C7H78 and C7H79. We here identified antioxidant peptides in fish sauce and revealed the antioxidant mechanism through molecular simulations.

NRF2 inhibitors: Recent progress, future design and therapeutic potential.

Nuclear factor erythroid 2-related factor 2 (NRF2) is a crucial transcription factor involved in oxidative stress response, which controls the expression of various cytoprotective genes. Recent research has indicated that constitutively activated NRF2 can enhance patients' resistance to chemotherapy drugs, resulting in unfavorable prognosis. Therefore, the development of NRF2 inhibitors has emerged as a promising approach for overcoming drug resistance in cancer treatment. However, there are limited reports and reviews focusing on NRF2 inhibitors. This review aims to provide a comprehensive analysis of the structure and regulation of the NRF2 signaling pathway, followed by a comprehensive review of reported NRF2 inhibitors. Moreover, the current design strategies and future prospects of NRF2 inhibitors will be discussed, aiming to establish a foundation for the development of more effective NRF2 inhibitors.

Endogenous electrophiles and peroxymonocarbonate can link tyrosine phosphorylation cascades with the cytosolic TXNRD1 selenoprotein and the KEAP1/NRF2 system.

Endogenously formed reactive molecules, such as lipid peroxides, 4-hydroxynonenal, methylglyoxal and other reactive oxygen species, can have major effects on cells. Accumulation of these molecules is counteracted by antioxidant enzymes, including the glutathione (GSH) and thioredoxin (Trx) systems, in turn regulated by the KEAP1/NRF2 system. Receptor tyrosine kinases (RTK) and their counteracting protein tyrosine phosphatases (PTP) are also modulated through redox regulation of PTP activities. The cytosolic selenoprotein thioredoxin reductase (TXNRD1) is particularly prone to attack at its easily accessible catalytic selenocysteine (Sec) residue by reactive electrophilic compounds. Therefore, we here discuss how endogenously formed electrophiles can modulate RTK/PTP signaling in a concentration- and time dependent manner by reactions either directly or indirectly linking TXNRD1 with the KEAP1/NRF2 system. Moreover, recent findings suggest that endogenous formation of peroxymonocarbonate can efficiently inhibit PTP activities and stimulate RTK signaling, seemingly bypassing PTP reduction as otherwise supported by the GSH/Trx systems.

Vitamin D receptor alleviates lipid peroxidation in diabetic nephropathy by regulating ACLY/Nrf2/Keap1 pathway.

The membrane lipid damage caused by reactive oxygen species(ROS) and various peroxides, namely lipid peroxidation, plays an important role in the progression of diabetic nephropathy (DN).We previously reported that vitamin D receptor(VDR) plays an active role in DN mice by modulating autophagy disorders. However, it is unclear whether the ATP-citrate lyase (ACLY)/NF-E2-related factor-2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1) pathway is associated with the reduction of lipid peroxidation by VDR in the DN model. We found that in the DN mouse model, VDR knockout significantly aggravated mitochondrial morphological damage caused by DN, increased the expression of ACLY, promoted the accumulation of ROS, lipid peroxidation products Malondialdehyde(MDA) and 4-hydroxy-2-nonenal (4-HNE),consumed the Nrf2/Keap1 system, thus increasing lipid peroxidation. However, the overexpression of VDR and intervention with the VDR agonist paricalcitol (Pari) can reduce the above damage. On the other hand, cellular experiments have shown that Pari can significantly reduce the elevated expression of ACLY and ROS induced by advanced glycation end products (AGE). However, ACLY overexpression partially eliminated the positive effects of the VDR agonist. Next, we verified the transcriptional regulation of ACLY by VDR through chromatin immunoprecipitation (ChIP)-qPCR and dual luciferase experiments. Moreover, in AGE models, knockdown of ACLY decreased lipid peroxidation and ROS production, while intervention with Nrf2 inhibitor ML385 partially weakened the protective effect of ACLY downregulation. In summary, VDR negatively regulates the expression of ACLY through transcription, thereby affecting the state of Nrf2/Keap1 system and regulating lipid peroxidation, thereby inhibiting kidney injury induced by DN.

Circ_001653 alleviates sepsis associated-acute kidney injury by recruiting BUD13 to regulate KEAP1/NRF2/HO-1 signaling pathway.

BACKGROUND: The kidney is exceptionally vulnerable during sepsis, often resulting in sepsis-associated acute kidney injury (SA-AKI), a condition that not only escalates morbidity but also significantly raises sepsis-related mortality rates. Circular RNA circ_001653 has been previously reported to be upregulated in the serum of SA-AKI patients, while the role and underlying mechanism of circ_001653 in SA-AKI remains unknown. In this study, we aimed to explore the functional role and the molecular mechanism of circ_001653 in the pathogenesis of SA-AKI. METHODS: LPS-stimulated HK-2 cells and ligation and perforation of cecum (CLP)-induced rats were used as in vitro and in vivo models of SA-AKI. The target gene expression levels were measured using qRT-PCR and western blot. Renal function (BUN, sCr, uNGAL, and uKIM-1), and renal pathological changes were detected in septic mice. TUNEL and EdU assays were conducted to measure apoptosis and proliferation rates in vitro. DCFH-DA staining was used to detect ROS levels in vitro and in vivo. Oxidative stress markers (SOD, GSH-Px, MDA, and SOD), and inflammation markers (IL-1ß, IL-6, and TNF-α) were determined using commercial kits both in vitro and in vivo. Additionally, gain-and-loss-of-function assays and mechanistic experiments were conducted to explore the regulatory role of circ_001653 in SA-AKI pathogenesis. RESULTS: Data showed that circ_001653 expression was high in LPS-stimulated HK-2 cells and CLP-induced rat renal tissue and was mainly localized in the cytoplasm. Notably, circ_001653 silencing alleviated SA-AKI by reducing apoptosis and alleviating oxidative stress and inflammation in HK-2 cells and renal tissue of rats. Mechanistically, it was found that circ_001653 alleviated SA-AKI by recruiting BUD13 to activate the KEAP1/Nrf2/HO-1 signaling pathway. CONCLUSIONS: To summarize, our study is the first to reveal elevated expression of circ_001653 in sepsis-associated AKI, and its downregulation effectively attenuates AKI by reducing apoptosis, inflammation, and oxidative stress. Mechanistically, circ_001653 exerts its effects by recruiting BUD13 to activate the KEAP1/Nrf2/HO-1 signaling pathway. These findings suggest circ_001653 as a potential therapeutic target for the drug development of sepsis-associated AKI.

Investigation of Nrf2-Keap-1 pathway, Sestrin 2 and oxidative stress markers in serum of patients with placenta Accreata spectrum.

Placenta accreta spectrum (PAS) is an important disease group with risks such as maternal bleeding, hysterectomy, and death, which expresses the pathological adhesion of the placenta to the uterine myometrium, including placenta accreta, increta, and percreta, with an increased incidence with an increase in cesarean section rates. In this study, we aimed to investigate the Nuclear factor erythroid 2-related factor 2 (Nrf2)-Kelch-like ECH-related protein 1 (Keap1) pathway in these patients. Serum Sestrin 2, Nrf2, Keap1, glycogen synthase kinase 3ß (GSK-3ß), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activities and malondialdehyde-modified low-density lipoprotein (MDA-LDL) levels were performed by the Enzyme-Linked Immunosorbent Assay (ELISA) method. In the findings obtained, Nrf2, Keap1, GSK-3ß, MDA-LDL levels, SOD and GSH-Px activities were statistically significantly different in the patient group compared to the control group. While MDA-LDL values were found to be high in the patient group, Nrf2, Keap1, GSK-3ß levels, SOD and GSH-Px activities were significantly lower, except for Sestrin 2 values. In addition, when grouped according to the degree of invasion, Nrf2 levels were found to be lower and Keap1 levels higher. As a result, it was determined that the Nrf2-Keap1 pathway was disrupted in PAS patients, and the oxidant/antioxidant balance was impaired in the oxidant direction. The results show that Nrf2 and Keap1 parameters can be useful in determining the degree of placental invasion.

Nrf2 pathways in neuroprotection: Alleviating mitochondrial dysfunction and cognitive impairment in aging.

Mitochondrial dysfunction and cognitive impairment are widespread phenomena among the elderly, being crucial factors that contribute to neurodegenerative diseases. Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important regulator of cellular defense systems, including that against oxidative stress. As such, increased Nrf2 activity may serve as a strategy to avert mitochondrial dysfunction and cognitive decline. Scientific data on Nrf2-mediated neuroprotection was collected from PubMed, Google Scholar, and Science Direct, specifically addressing mitochondrial dysfunction and cognitive impairment in older people. Search terms included "Nrf2", "mitochondrial dysfunction," "cognitive impairment," and "neuroprotection." Studies focusing on in vitro and in vivo models and clinical investigations were included to review Nrf2's therapeutic potential comprehensively. The relative studies have demonstrated that increased Nrf2 activity could improve mitochondrial performance, decrease oxidative pressure, and mitigate cognitive impairment. To a large extent, this is achieved through the modulation of critical cellular signalling pathways such as the Keap1/Nrf2 pathway, mitochondrial biogenesis, and neuroinflammatory responses. The present review summarizes the recent progress in comprehending the molecular mechanisms regarding the neuroprotective benefits mediated by Nrf2 through its substantial role against mitochondrial dysfunction and cognitive impairment. This review also emphasizes Nrf2-target pathways and their contribution to cognitive function improvement and rescue from mitochondria-related abnormalities as treatment strategies for neurodegenerative diseases that often affect elderly individuals.

Inhibition of ubiquitin-specific protease 7 ameliorates ferroptosis-mediated myocardial infarction by contrasting oxidative stress: An in vitro and in vivo analysis.

BACKGROUND: Our prior research determined that USP7 exacerbates myocardial injury. Additionally, existing studies indicate a strong connection between USP7 and ferroptosis. However, the influence of USP7 on ferroptosis-mediated myocardial infarction (MI) remains unclear. Given these findings, we are particularly interested in USP7's regulatory role in ferroptosis-mediated MI and its underlying mechanisms. METHODS: In this study, we established MI models and lentivirus-transfected groups to inhibit USP7 expression both in vivo and in vitro. Cardiac function was detected with Echocardiography. TTC and HE staining were employed to assess myocardial alterations. The expression of ferroptosis markers (PTGS2, ACSL4, GPX4) were analyzed by RT-qPCR and Western blotting. Flow cytometry and ELISA were used for measuring Fe2+, lipid ROS, GSH, and GSSG levels. TEM and Prussian blue staining were used to observe mitochondrial alterations and iron deposition. RT-qPCR, Western blotting, and immunofluorescence were conducted to analyze Keap1, Nrf2, and nuclear Nrf2 expression in vitro and in vivo. RESULTS: In the MI model group, USP7 expression significantly increased, worsening ferroptosis-mediated MI. Conversely, in the USP7-inhibited group, activation of the Keap1-Nrf2 signaling pathway improved ferroptosis-mediated MI outcomes. In vitro, the MI model exhibited a marked decline in cardiomyocyte viability and notable mitochondrial damage. However, these issues improved in the USP7-inhibited groups. In vivo, USP7 intensified MI and iron deposition within the MI model group, with decreased values of LVEF, LVFS, SV, LVAWd, and LVPWs, all of which showed improvement in the USP7-inhibited group, except for LVPWd and LVPWs, which showed no significant variation. Importantly, both the in vitro and in vivo experiments revealed analogous results: a reduction in Keap1 expression and an increase in both Nrf2 and nuclear Nrf2 post USP7 inhibition. Additionally, GPX4 expression decreased while PTGS2 and ACSL4 expressions increased. Notably, concentrations of Fe2+, lipid ROS, GSH, and GSSG significantly decreased. CONCLUSION: In vitro and in vivo studies have found that inhibition of USP7 attenuates iron deposition and suppresses oxidative stress, resulting in amelioration of ferroptosis-induced MI.

Allosteric regulation of Keap1 by 8ß-hydroxy-α-cyclocostunolide for the treatment of acute lung injury.

Image 1.

The role of Keap1-Nrf2 signaling pathway in the treatment of respiratory diseases and the research progress on targeted drugs.

Lungs are exposed to external oxidants from the environment as in harmful particles and smog, causing oxidative stress in the lungs and consequently respiratory ailment. The NF-E2-related factor 2 (Nrf2) is the one with transcriptional regulatory function, while its related protein Kelch-like ECH-associated protein 1 (Keap1) inhibits Nrf2 activity. Together, they form the Keap1-Nrf2 pathway, which regulates the body's defense against oxidative stress. This pathway has been shown to maintain cellular homeostasis during oxidative stressing, inflammation, oncogenesis, and apoptosis by coordinating the expression of cytoprotective genes and making it a potential therapeutic target for respiratory diseases. This paper summarizes this point in detail in Chapter 2. In addition, this article summarizes the current drug development and clinical research progress related to the Keap1-Nrf2 signaling pathway, with a focus on the potential of Nrf2 agonists in treating respiratory diseases. Overall, the article reviews the regulatory mechanisms of the Keap1-Nrf2 signaling pathway in respiratory diseases and the progress of targeted drug research, aiming to provide new insights for treatment.

Nuclear factor erythroid 2-related factor 2 (Nrf2) signaling in heavy metals-induced oxidative stress.

Organisms encounter reactive oxidants through intrinsic metabolism and environmental exposure to toxicants. Reactive oxygen and nitrogen species (ROS, RNS) are generally considered detrimental because they induce oxidative stress. In order to combat oxidative stress, a potential modulator of cellular defense nuclear factor erythroid 2-related factor 2 (Nrf2) and its endogenous inhibitor Kelch-like ECH-associated protein 1 (Keap1) operate as a common, genetically preserved intrinsic defense system. There has been a significant increase in the amount of harmful metalloids and metals that individuals are exposed to through their food, water, and air, primarily due to human activities. Many studies have looked at the connection between the emergence of different ailments in humans and ecological exposure to metalloids, i.e., arsenic (As) and metals viz., chromium (Cr), mercury (Hg), cadmium (Cd), cobalt (Co), and lead (Pb). It is known that they can produce ROS in several organs by both direct and indirect means. Studies suggest that Nrf2 signaling is a crucial mechanism in maintaining antioxidant balance and can have two roles, depending on the particular biological setting. From one perspective, Nrf2 is an essential defense mechanism against metal-induced toxicity. Still, it may also operate as a catalyst for metal-induced carcinogenesis in situations involving protracted exposure and persistent activation. Therefore, this review aims to provide an overview of the antioxidant defense mechanism of Nrf2-Keap1 signaling and the interrelation between Nrf2 signaling and the toxic elements.

Genome-Wide CRISPR Screen Identifies KEAP1 Perturbation as a Vulnerability of ARID1A-Deficient Cells.

ARID1A is the core DNA-binding subunit of the BAF chromatin remodeling complex and is mutated in about 8% of all cancers. The frequency of ARID1A loss varies between cancer subtypes, with clear cell ovarian carcinoma (CCOC) presenting the highest incidence at > 50% of cases. Despite a growing understanding of the consequences of ARID1A loss in cancer, there remains limited targeted therapeutic options for ARID1A-deficient cancers. Using a genome-wide CRISPR screening approach, we identify KEAP1 as a genetic dependency of ARID1A in CCOC. Depletion or chemical perturbation of KEAP1 results in selective growth inhibition of ARID1A-KO cell lines and edited primary endometrial epithelial cells. While we confirm that KEAP1-NRF2 signalling is dysregulated in ARID1A-KO cells, we suggest that this synthetic lethality is not due to aberrant NRF2 signalling. Rather, we find that KEAP1 perturbation exacerbates genome instability phenotypes associated with ARID1A deficiency. Together, our findings identify a potentially novel synthetic lethal interaction of ARID1A-deficient cells.

Computational Analysis and Experimental Data Exploring the Role of Hesperetin in Ameliorating ADHD and SIRT1/Nrf2/Keap1/OH-1 Signaling.

Attention deficit hyperactivity disorder (ADHD) manifests as poor attention, hyperactivity, as well as impulsive behaviors. Hesperetin (HSP) is a citrus flavanone with strong antioxidant and anti-inflammatory activities. The present study aimed to test hesperetin efficacy in alleviating experimental ADHD in mice and its influence on hippocampal neuron integrity and sirtuin 1 (SIRT1) signaling. An in silico study was performed to test the related proteins. Groups of mice were assigned as control, ADHD model, ADHD/HSP (25 mg/kg), and ADHD/HSP (50 mg/kg). ADHD was induced by feeding with monosodium glutamate (0.4 g/kg, for 8 weeks) and assessed by measuring the motor and attentive behaviors (open filed test, Y-maze test, and marble burying test), histopathological examination of the whole brain tissues, and estimation of inflammatory markers. The in-silico results indicated the putative effects of hesperetin on ADHD by allowing the integration and analysis of large-scale genomic, transcriptomic, and proteomic data. The in vivo results showed that ADHD model mice displayed motor hyperactivity and poor attention in the behavioral tasks and shrank neurons at various hippocampal regions. Further, there was a decline in the mRNA expression and protein levels for SIRT1, the erythroid 2-related factor-2 (Nrf2), kelch like ECH associated protein 1 (Keap1) and hemeoxygenase-1 (OH-1) proteins. Treatment with HSP normalized the motor and attentive behaviors, prevented hippocampal neuron shrinkage, and upregulated SIRT1/Nrf2/Keap1/OH-1 proteins. Taken together, HSP mainly acts by its antioxidant potential. However, therapeutic interventions with hesperetin or a hesperetin-rich diet can be suggested as a complementary treatment in ADHD patients but cannot be suggested as an ADHD treatment per se as it is a heterogeneous and complex disease.

Lutein protects senescent ciliary muscle against oxidative stress through the Keap1/Nrf2/ARE pathway.

BACKGROUND: Aging-induced decline in ciliary muscle function is an important factor in visual accommodative deficits in elderly adults. With this study, we provide an innovative investigation of the interaction between ciliary muscle aging and oxidative stress. METHODS: Tricolor guinea pigs were used for the experiments in vivo and primary guinea pig ciliary smooth muscle cells were used for the experiments in vitro. RESULTS: We enriched for genes associated with muscle-aging-lutein relationship using bioinformatics, including Nuclear factor-erythroid 2-related factor-2 (Nrf2), Glutathione Peroxidase (GPx) gene family, Superoxide Dismutase (SOD) gene family, NAD(P)H: Quinone Oxidoreductase 1 (NQO1) and Heme Oxygenase-1 (HO-1). After gavage to aged guinea pigs, lutein reduced Reactive Oxygen Species (ROS) and P21 levels in senescent ciliary muscle; lutein decreased refractive error and restored accommodation of the eye. In addition, lutein increased GPx, SOD, and Catalase (CAT) levels in serum; lutein increased GPx and CAT levels in ciliary bodies. Lutein regulated the expression of proteins such as Nrf2, Kelch-like ECH-associated protein 1 (Keap1), and downstream proteins in senescent ciliary bodies. Similarly, guinea pig ciliary muscle cell senescence was associated with oxidative stress. In vitro, 100 µM lutein reversed the damage caused by 800 µM H2O2; it reduced Senescence-Associated ß-galactosidase (SA-ß-Gal) and ROS activites, cell apoptosis and cell migration. Also, lutein increased the expression of smooth muscle contractile proteins. Lutein also increased the expression of Nrf2, GPx2, NQO1 and HO-1, decreased the expression of Keap1. A reduction in Nrf2 activity led to a reduction in the ability of lutein to activate antioxidant enzymes in the cells, thus reducing its inhibitory effect on cell senescence. CONCLUSION: lutein improved resistance to oxidative stress in senescent ciliary muscle in vivo and in vitro by regulating the Keap1/Nrf2/Antioxidant Response Element pathway. We have innovatively demonstrated the molecular pharmacological mechanism by which lutein reverse age-related ciliary muscle systolic and diastolic deficits.

Natural Linoleic Acid from Marine Fungus Eutypella sp. F0219 Blocks KEAP1/NRF2 Interaction and Ameliorates MASLD by Targeting FABP4.

Ectopic lipid accumulation induced lipotoxicity plays a crucial role in exacerbating the development of metabolic dysfunction-associated steatotic liver disease (MASLD), which affects over 30% of the worldwide population and 85% of the obese population. The growing demand for effective therapeutic agents highlights the need for high-efficacy lipotoxicity ameliorators and relevant therapeutic targets in the fight against MASLD. This study aimed to discover natural anti-lipotoxic and anti-MASLD candidates and elucidate the underlying mechanism and therapeutic targets. Utilizing palmitic acid (PA)-induced HepG-2 and primary mouse hepatocyte models, we identified linoleic acid (HN-002), a ligand of fatty acid binding protein 4 (FABP4), from the marine fungus Eutypella sp. F0219. HN-002 dose-dependently prevented lipid overload-induced hepatocyte damage and lipid accumulation, inhibited fatty acid esterification, and ameliorated oxidative stress. These beneficial effects were associated with improvements in mitochondrial adaptive oxidation. HN-002 treatment enhanced lipid transport into mitochondria and oxidation, inhibited mitochondrial depolarization, and reduced mitochondrial ROS (mtROS) level in PA-treated hepatocytes. Mechanistically, HN-002 treatment disrupted the interaction between KEAP1 and NRF2, leading to NRF2 deubiquitylation and nuclear translocation, which activated beneficial metabolic regulation. In vivo, HN-002 treatment (20 mg/kg/per 2 days, i. p.) for 25 days effectively reversed hepatic steatosis and liver injury in the fast/refeeding plus high-fat/high-cholesterol diet induced MASLD mice. These therapeutic effects were associated with enhanced mitochondrial adaptive oxidation and activation of NRF2 signaling in the liver. These data suggest that HN-002 would be an interesting candidate for MASLD by improving mitochondrial oxidation via the FABP4/KEAP1/NRF2 axis. The discovery offers new insights into developing novel anti- MASLD agents derived from marine sources.

[Suppression effect of secoisolariciresinol diglucoside against trans fatty acids-induced oxidative damage and inflammatory in brain of offspring mice].

OBJECTIVE: To probe into the protective effect of different dose of secoisolariciresinol diglucoside(SDG) on brain of offspring of mice anainst oxidative damage and inflammatory reaction induced by maternal exposure to trans fatty acids(TFA) during gestation, and observe the the changes of regulating Nrf2/Keap1 pathway in the course. METHODS: 30 healthy female mice(C57BL/6) were divided into 5 groups randomly, they are respectively control group, TFA-exposed group, and three SDG-intervention groups(low-(TFA+LSDG), medium-(TFA+MSDG) and high-(TFA+HSDG)). The pregnancy mice of control group and TFA group were treated with distilled water and 60 mg/kg·d TFA by gavage, in the same time, the mice of three SDG-intervention groups were treated with 60 mg/kg·d TFA by gavage and fed with feed included SDG(10, 20 and 30 mg/kg). The treatment to pregnancy mice continued to birth of offspring. After 21 days of lactation, the offspring were killed under anesthesia and the experiment was ended. The coefficient of brain was calculated. The levels of superoxide dismutase(SOD), glutathione peroxidase(GSH-Px), malondialdehyde(MDA), tumor necrosis factor-α(TNF-α), interferon-γ(IFN-γ) and amyloid-ß(Aß)of brain were detected. RT-PCR and Western Blot was used to detected gene expression and protein levels of nuclear factor erythroid-2 related factor 2(Nrf2), kelch-like ECH-associated protein 1(Keap1), quinone oxidoreductase 1(NQO1) and hemeoxygenase-l(HO-1). RESULTS: Compared with control group, the brain coefficient and Aß1-40 of offspring of TFA-group had no significant changes(P>0.05), the activity of SOD and GSH-Px reduced, the content of MDA, IFN-γ, TNF-α and Aß1-42 increased, the level of mRNA and protein expression of Nrf2, NQO1 and HO-1 decreased and the level of mRNA and protein expression of Keap1 increase because of the exposion to TFA during gestation and all the differences were statistically significant(P<0.05). Compared with TFA-group, the brain coefficient, Aß1-40 and the level of NQO1 mRNA of offspring of three SDG-intervention groups had no significant changes(P>0.05), the activity of SOD(the middle and high dose SDG intervention groups) and GSH-Px(three SDG-intervention groups) increased, the content of MDA(the middle and high dose SDG intervention groups), IFN-γ(the middle and high dose SDG intervention groups), TNF-α(three SDG-intervention groups) and Aß1-42(the middle and high dose SDG intervention groups) decreased, the mRNA expression of Nrf2 and HO-1(the middle and high dose SDG intervention groups) was up-regulated, the mRNA expression of Keap1(the middle and high dose SDG intervention group) decreased, proteic expression of Nrf2, NQO1 and HO-1 of three SDG-intervention groups increase and the level of protein of Keap1 decreased because of the intervention of SDG during gestation(P<0.05). CONCLUSION: These result suggest that maternal TFA exposure during gestation can result in oxidative stress and inflammation to brain of offspring in a way. SDG can protect brain of mice of offspring from TFA-induced oxidative injury by up-regulating the expression of mRNA and protein of Nrf2, down-regulating the expression of Keap1, accelerating expression of protein of NQO1 and HO-1 which are antioxidant protein lying downstream of pathway of Nrf2/Keap1.

KEAP1-NRF2 pathway as a novel therapeutic target for EGFR-mutant non-small cell lung cancer.

BACKGROUND: Kelch-like ECH-associated protein 1 (KEAP1)-nuclear factor erythroid-2-related factor 2 (NRF2) pathway is a major regulator protecting cells from oxidative and metabolic stress. Studies have revealed that this pathway is involved in mediating resistance to cytotoxic chemotherapy and immunotherapy, however, its implications in oncogene-addicted tumors are largely unknown. This study aimed to elucidate whether this pathway could be a potential therapeutic target for epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer. METHODS: We measured the baseline expression of NRF2 using EGFR-mutant parental cells and acquired gefitinib resistant cells. We investigated whether NRF2 inhibition affected cell death in vitro and tumor growth in vivo using a xenograft mouse model, and compared the transcriptional changes before and after NRF2 inhibition. RESULTS: Baseline NRF2 expression was enhanced in PC9 and PC9 with gefitinib resistance (PC9/GR) cells than in other cell lines, with a more prominent expression in PC9/GR. The NRF2 inhibitor induced NRF2 downregulation and cell death in a dose-dependent manner. Co-treatment with an NRF2 inhibitor enhanced osimertinib-induced cell death in vitro, and potentiated tumor growth inhibition in a PC9/GR xenograft model. Finally, RNA sequencing revealed that NRF2 inhibition resulted in the altered expression of multiple genes involved in various signaling pathways. CONCLUSION: We identified that NRF2 inhibition enhanced cell death and inhibited tumor growth in TKI-resistant lung cancer with EGFR-mutation. Thus, NRF2 modulation may be a novel therapeutic strategy to overcome the resistance to EGFR-tyrosine kinase inhibitors.

New insights into evodiamine attenuates IPEC-J2 cells pyroptosis induced by T-2 toxin - Activating Keap1-Nrf2/NF-κB signaling pathway through binding with Keap1.

T-2 toxin (T-2) is a highly toxic mycotoxin with a molecular weight of 466.52 g/mol. Evodiamine (EV), an alkaloid component of Evodia, has anti-inflammation and antioxidant properties. As a receptor of oxidative stress, Keap1 with a molecular weight of 70 kDa, is a molecular switch that controls the Nrf2 signaling pathway. In this paper, the effect of EV on Keap1-Nrf2/NF-κB pathway was investigated. Based on our research outcomes, it was observed that T-2 exposure substantially increased IPEC-J2 cells intracellular ROS levels and MDA accumulation, decreased SOD and CAT activities, disrupted intestinal tight junction (ZO-1, occludin, and claudin-1), and up-regulated pyroptosis-related protein (ASC, NLRP3, caspase-1, GSDMD, IL-1ß, and IL-18). Additionally, EV could bind well with Keap1, the separating it from Nrf2, promoting Nrf2 into the nucleus, enhanced antioxidant enzyme activities, reduced the production of ROS, down-regulated NF-κB expression, alleviated T-2-induced pyroptosis, and restored tight junction protein expression. However, after treatment with the Nrf2 inhibitor ML385, ML385 reversed the protective effect of EV on IPEC-J2 cells. Collectively, EV can activate the Keap1-Nrf2/NF-κB signaling pathway via binding to Keap1, exert anti-inflammatory and antioxidant effects, inhibit the pyroptosis of IPEC-J2 cells triggered by T-2, and retore intestinal barrier function.

Enhancing radioprotection: exploring the impact of L-carnitine supplementation on the oxidative stress in the liver.

BACKGROUND: The adverse effects of radiotherapy (RT) primarily occur through oxidative stress, and attempts are being made to mitigate these effects. L-Carnitine (L-Car) involved in physiological functions, possesses antioxidant and tissue-protective properties. The goal of this investigation is to appraise the radioprotective efficacy of L-Car supplementation. METHODS AND RESULTS: The groups were established by dividing thirty-two rats as: control, RT (10 Gy), RT + L-Car (200 mg/kg/d), L-Car. Upon completion of the experiment, the livers were harvested for histopathological, immunostaining [tumor necrosis factor-alpha (TNF-α), Caspase-3], spectrophotometric [total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI)], and mRNA expression [(Nuclear factor erythroid 2-related factor 2 (Nrf2), Kelch-like ECH-associated protein 1 (Keap-1), Heme Oxygenase (HO-1), Transforming growth factor beta 1 (TGF-ß1)] analyses. In the damage group, decreased Keap-1, Nrf2, HO-1, and TAS values, along with increased histopathological findings, alanine transferase, aspartate transferase, TNF-α, Caspase-3, TOS, OSI, TGF-ß1 levels were found. All findings were improved with L-Car treatment. CONCLUSIONS: Considering these findings, it can be inferred that L-Car exhibits tissue-protective effects against organ damage predominantly induced by RT-related oxidative stress. Additionally, it has prevented the development of inflammation, apoptosis, and fibrosis. Therefore, L-Car may be considered as a supplement to reduce complications associated with RT.