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.

Nodule-specific NRF2-targeted upregulation in patients with KEAP1 mutations and familial nontoxic multinodular goiter.

CONTEXT: Kelch-like ECH-associated protein 1 (KEAP1) is associated with nuclear factor erythroid-2 related factor 2 (NRF2) and promotes NRF2 degradation in normal conditions. Genetic abnormality in KEAP1 is a rare disease and presents with familial multinodular goiter. OBJECTIVE: This study assessed the clinical and molecular findings concerning nodular formation in the thyroid gland of patients harboring KEAP1 germline mutations. METHODS: Next-generation sequencing analysis targeting goiter-associated genes was performed on 39 patients with familial multinodular goiter. The expression of NRF2-targeted genes from surgical thyroid specimens of patients with KEAP1 mutations were analyzed using a whole transcript expression array and immunohistochemistry. RESULTS: We found five probands with pathogenic heterozygous mutations in KEAP1 (p.Q86*, p.L136P, p.V411fs, p.R415C, and p.R483H), which had no meaningful concomitance with mutations of other goiter-associated genes in germline and somatic levels. Their common histopathological features showed multinodular goiters in the entire thyroid gland with few degenerative lesions or complications of malignancy and slow proliferation indicating < 1% at the Ki-67 labeling index. Among 42 NRF2-targeted genes, antioxidant genes were most frequently upregulated (11/12) in the nodule, followed by detoxification genes (6/11). Immunohistochemical analysis showed relatively high expression of glutathione peroxidase 2 and NAD(P)H quinone oxidoreductase 1 (representative NRF2-targeted genes) in the nodules of various patients harboring KEAP1 mutations. CONCLUSION: KEAP1 germline heterozygous mutations exert excessive NRF2 activity in the thyroid gland and may confer cytoprotective effects even under abundant reactive oxygen species associated with thyroid hormone production, resulting in thyroid hyperplasia with scarce degradation.

Quercetin as a therapeutic agent activate the Nrf2/Keap1 pathway to alleviate lung ischemia-reperfusion injury.

Lung ischemia-reperfusion injury (LIRI) causes oxidative stress, inflammation, and immune system activation. The Nrf2/Keap1/HO-1 pathway is important in cellular defense against these effects. Quercetin, a flavonoid with antioxidant, anti-inflammatory, and anti-cancer properties, has been investigated. Our aim in this study was to investigate the effect of quercetin on preventing lung ischemia-reperfusion injury and the role of the Nrf2/Keap1/HO-1 pathway. Sixty-four male Wistar rats were divided into four distinct groups(n = 16). Sham, lung ischemia-reperfusion (LIR), Saline + LIR, Quercetin + LIR (30 mg/kg i.p for a week before LIR). LIR groups were subjected to 60 min of ischemia (left pulmonary artery, vein, and bronchus) and 120 min of reperfusion. Our assessment encompassed a comprehensive analysis of various factors, including the evaluation of expression Nrf2, Keap1, and Heme Oxygenase-1 (HO-1) levels and NF-κB protein. Furthermore, we examined markers related to inflammation (interleukin-1ß and tumor necrosis factor alpha), oxidative stress (malondialdehyde, total oxidant status, superoxide dismutase, glutathione peroxidase, total antioxidant capacity), lung edema (Wet/dry lung weight ratio and total protein concentration), apoptosis (Bax and Bcl2 protein), and histopathological alterations (intra-alveolar edema, alveolar hemorrhage, and neutrophil infiltration). Our results show that ischemia-reperfusion results in heightened inflammation, oxidative stress, apoptosis, lung edema, and histopathological damage. Quercetin showed preventive effects by reducing these markers, acting through modulation of the Nrf2/Keap1 pathway and inhibiting the NF-κB pathway. This anti-inflammatory effect, complementary to the antioxidant effects of quercetin, provides a multifaceted approach to cell protection that is important for developing therapeutic strategies against ischemia-reperfusion injury and could be helpful in preventive strategies against ischemia-reperfusion.

Senegenin regulates the mechanism of insomnia through the Keap1/Nrf2/PINK1/Parkin pathway mediated by GAD67.

GAD67 impacts insomnia as a key enzyme catalysing the conversion of glutamate (Glu) to gamma-aminobutyric acid (GABA). Senegenin enhances neuroprotection and is used widely to treat insomnia and other neurological diseases. This study aimed to investigate how senegenin regulates insomnia through a GAD67-mediated signalling pathway. We measured GAD67 expression levels in insomnia patients and evaluated the expression levels of GAD67 and Keap1/Nrf2/Parkin/PINK1-related cytokines following GAD67 lentiviral transfection in PC12 cells and in rat models. We also assessed cellular reactive oxygen species (ROS) and mitochondrial membrane potential levels. Additionally, EEG/EMG was used to analyse the sleep phases of rats and to assess memory and exploration functions. Pathological changes and the expression of GAD67 and sleep-related proteins in the hippocampus were examined. The results showed that GAD67 expression was increased in insomnia patients, ROS levels were elevated, and the mitochondrial membrane potential was decreased in the GAD67-KD group. Insomnia rats exhibited changes in sleep rhythm, learning, and exploration dysfunction, pathological changes in the CA1 region of the hippocampus, and differential expression of GAD67 and sleep-related factors. Inhibitory neurofactor expression levels were decreased in insomnia rats, showing a positive correlation in the GAD67-KD group and a negative correlation in the GAD67-OE group. Conversely, excitatory factor expression levels were increased in insomnia rats, showing a positive correlation in the GAD67-KD group and a negative correlation in the GAD67-OE group. Senegenin intervention modulated cytokine expression levels. In conclusion, GAD67 negatively regulates insomnia, and senegenin can regulate insomnia by mediating the expression of cytokines in the GAD67-regulated Keap1/Nrf2/Parkin/PINK1 pathway.

Structural characterization, HepG2 cell cytoprotective ability, and antioxidant mechanism of novel antioxidant peptides identified from black soldier fly larvae (Hermetia illucens L.).

This study isolated a novel antioxidant peptide from black soldier fly larvae (BSFL) using enzymatic hydrolysis. Firstly, the BSFL enzymatic hydrolysate was fractionated through ultrafiltration, with the <3 kDa fraction exhibiting the strongest DPPH and ABTS radical scavenging activity. Subsequently, this fraction was further fractionated through gel filtration chromatography and RP-HPLC. Totally, 153 peptides were identified through LC-MS/MS analysis, from which a novel peptide EDEGTYKCVLS (Pep6) was screened according to activity prediction and verification. Pep6 exhibited high radical scavenging capacity and cytoprotective effect on HepG2 cells against H2O2 damage, meanwhile significantly increasing the intracellular antioxidant enzymes activity. Molecular docking analysis indicated that Pep6 competitively bound to Keap1, thereby inhibiting the formation of Keap1-Nrf2 complex, ultimately protecting cells from oxidative stress damage. In this study, a novel antioxidant peptide Pep6 was identified from BSFL, and its antioxidant mechanism was elucidated, providing a theoretical basis for its use as a natural antioxidant.

Pharmacodynamic insights into maresin 1: Enhancing flap viability via the keap1/Nrf2 axis to control ROS-driven apoptosis and ferroptosis.

Random flaps are widely used in tissue reconstruction, but the high incidence of flap necrosis after operation remains a significant challenge. Maresin 1 (MaR1), a mediator derived from docosahexaenoic acid, has been shown to have significant effects in resolving inflammation and promoting tissue regeneration. This study investigated the role of MaR1 in the survival of random flaps. Histological analysis, laser Doppler blood flow imaging, Masson trichrome staining, and survival area analysis were used to assess the viability of the flaps. Apoptosis, ferroptosis, oxidative stress, angiogenesis, and the underlying mechanisms were explored by examining the expression of specific molecules using immunofluorescence, western blotting, and other immunological and molecular biology techniques. The findings demonstrated that MaR1 could improve flap lifespan by significantly reducing oxidative stress, apoptosis, and ferroptosis, as well as by enhancing angiogenesis. The Keap1-Nrf2 pathway was upregulated by MaR1, which inhibited ROS-mediated apoptosis and ferroptosis. The protective effect of MaR1 on flap survival was abolished by ML385. Our findings indicate that MaR1 could be a novel therapeutic agent for enhancing flap treatment outcomes.

Bioactive proteins and antioxidant peptides from Litsea cubeba fruit meal: Preparation, characterization and ameliorating function on high-fat diet-induced NAFLD through regulating lipid metabolism, oxidative stress and inflammatory response.

Non-alcoholic fatty liver disease (NAFLD) plays an increasingly significant threat to human health. In this study, the processing by-products of Litsea cubeba fruit meal were defatted by ultrasound-assisted methods, then the acetone-precipitated protein of L. cubeba (LCP) was obtained and structural analysis was performed. LCP was hydrolyzed by a two-step sequential hydrolysis method using alcalase and papain. Subsequently, antioxidant peptide fraction (IV2) was isolated and identified from the resultant hydrolysate through membrane ultrafiltration, Sephadex G-15 chromatography, and liquid chromatograph mass spectrometer (LC-MS). Animal experimentation indicated the potential of IV2 to mitigate hepatic steatosis. Moreover, IV2 could effectively reduce oxidative stress-induced damage by modulating the Keap1-Nrf2 pathway to activate downstream heme oxygenase-1 (HO-1) and NAD(P) H quinone oxidoreductase 1 (NQO1). Integrating metabolomics and transcriptomics revealed enrichment in pathways associated with glycerolipid metabolism and fatty acid ß-oxidation, suggesting the principal mechanisms underlying IV2's ameliorative effects on NAFLD. Transcriptome sequencing identified 3092 up-regulated and 3010 down-regulated genes following IV2 treatment. Interaction analyses based on different lipid compositions (DELs) and differentially expressed genes (DEGs) indicated that IV2 primarily alleviated hepatic steatosis by modulating peroxisome proliferator-activated receptor α (PPAR-α) related pathways, thereby augmenting fatty acid ß-oxidation within liver cells. These results indicate that IV2 shows potential in improving high-fat diet (HFD)-induced NAFLD, with improved fatty acid ß-oxidation and reduced triglyceride biosynthesis emerging as underlying mechanisms.

Serine ubiquitination of SQSTM1 regulates NFE2L2-dependent redox homeostasis.

The KEAP1-NFE2L2 axis is essential for the cellular response against metabolic and oxidative stress. KEAP1 is an adaptor protein of CUL3 (cullin 3) ubiquitin ligase that controls the cellular levels of NFE2L2, a critical transcription factor of several cytoprotective genes. Oxidative stress, defective autophagy and pathogenic infections activate NFE2L2 signaling through phosphorylation of the autophagy receptor protein SQSTM1, which competes with NFE2L2 for binding to KEAP1. Here we show that phosphoribosyl-linked serine ubiquitination of SQSTM1 catalyzed by SidE effectors of Legionella pneumophila controls NFE2L2 signaling and cell metabolism upon Legionella infection. Serine ubiquitination of SQSTM1 sterically blocks its binding to KEAP1, resulting in NFE2L2 ubiquitination and degradation. This reduces NFE2L2-dependent antioxidant synthesis in the early phase of infection. Levels of serine ubiquitinated SQSTM1 diminish in the later stage of infection allowing the expression of NFE2L2-target genes; causing a differential regulation of the host metabolome and proteome in a NFE2L2-dependent manner.Abbreviation: ARE: antioxidant response element; Dup: deubiquitinase specific for phosphoribosyl-linked serine ubiquitination; ER: endoplasmic reticulum; h.p.i: hours post infection; HIF1A/HIF-1α: hypoxia inducible factor 1 subunit alpha; KEAP1: kelch like ECH associated protein 1; KIR: KEAP1-interacting region; LIR: LC3-interacting region; NES: nuclear export signal; NFKB/NF-κB: nuclear factor kappa B; NLS: nuclear localization signal; NFE2L2/Nrf2: NFE2 like bZIP transcription factor 2; PB1 domain: Phox1 and Bem1 domain; PR-Ub: phosphoribosyl-linked serine ubiquitination; ROS: reactive oxygen species; SQSTM1/p62: sequestosome 1; tBHQ: tertiary butylhydroquinone; TUBE2: tandem ubiquitiin binding entity 2; UBA domain: ubiquitin-associated domain.

LFHP-1c improves cognitive function after TBI in mice by reducing oxidative stress through the PGAM5-NRF2-KEAP1 ternary complex.

Traumatic brain injury (TBI) is a leading cause of disability and death. Thus, timely and effective secondary brain injury intervention is crucial, with potential to improve the prognosis of TBI. Oxidative stress contributes to post-traumatic secondary cognitive impairment, and the reduction of post-traumatic oxidative stress effectively enhances cognitive function. Phosphoglycerate-mutating enzyme 5 (PGAM5), a member of the phosphoglycerate transporter enzyme family, is upregulated in TBI and induces mitochondrial autophagy. This further exacerbates damage following TBI. The present study focused on the small molecule drug, LFHP-1c, which is a novel inhibitor of PGAM5. The present study used an in vivo mouse model incorporating a controlled cortical impact-induced TBI, to examine the impact of LFHP-1c on oxidative stress and cognitive function. The present study aimed to determine the impact of LFHP-1c on the PGAM5-Kelch-like ECH-associated protein 1 (KEAP1)- nuclear factor erythroid 2-related factor 2 (NRF2) ternary complex within the TBI context. Results of the present study indicated that LFHP-1c suppresses PGAM5 expression and inhibits the development of the PGAM5-KEAP1-NRF2 ternary complex, thereby promoting the release of NRF2 and KEAP1. This in turn promotes the entry of NRF2 into the nucleus following TBI, leading to increased expression of anti-oxidative stress downstream factors, such as heme oxygenase-1, glutathione peroxidase 1 and superoxide dismutase 1. In addition, LFHP-1c also released KEAP1, leading to mitochondrial Rho GTPase 2 degradation and reducing perinuclear aggregation of mitochondria in the cell, which reduced oxidative stress and ultimately improved cognitive function after TBI.

New insights into mechanism of ellagic acid alleviating arsenic-induced oxidative stress through MAPK/keap1-Nrf2 signaling pathway response, molecular docking and metabolomics analysis in HepG2 cells.

The increase of oxidative stress level is one of the vital mechanisms of liver toxicity induced by arsenic (As). Ellagic acid (EA) is widely known due to its excellent antioxidation. Nevertheless, whether EA could alleviate As-induced oxidative stress and the underlying mechanisms remain unknown. Herein, As (2 and 4 µM) and EA (25 and 50 µM) were selected for alone and combined exposure of HepG2 cells to investigate the effects of EA on As-induced oxidative stress. Results indicated that EA could alleviate the oxidative stress caused by As via decreasing intracellular ROS level and MDA content, as well as improving SOD, CAT and GSH-PX activities. qRT-PCR showed that EA might enhance the expression levels of antioxidant enzymes NQO1, CAT and GPX1 by activating MAPK (JNK, p38 and ERK)/keap1-Nrf2 signaling pathway. EA was found to promote dissociation from keap1 and nuclear translocation of Nrf2 by competing with Nrf2 at ARG-380 and ARG-415 sites on keap1 to exert antioxidation using molecular docking. Moreover, metabolomics revealed that EA might maintain the redox balance of HepG2 cells by modulating or reversing disorders of carbon, amino acid, lipid and other metabolisms caused by As. This study provides diversified new insights for the removal of liver toxicity of As and the application of EA.

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.

miR-141-3p promotes paclitaxel resistance by attenuating ferroptosis via the Keap1-Nrf2 signaling pathway in breast cancer.

Purpose: Breast cancer poses a huge threat to the lives and health of women worldwide. However, drug resistance makes the treatment of breast cancer challenging. This study aims to investigate the effect of miR-141-3p on paclitaxel resistance and its underlying mechanisms in breast cancer. Methods: Using bioinformatics analysis and qRT-PCR to explore the potential molecule miR-141-3p. Specific binding of miR-141-3p to Keap1 was determined by using a dual luciferase reporter assay. qRT-PCR and Western blot were utilized to observe the expression of miR-141-3p, Keap1, Nrf2, SLC7A11 and GPX4. GSH/GSSG content, MDA content and JC-1 assays were used to observe the ferroptosis levels of breast cancer cells. CCK-8 assay was used to observe the cell viability of breast cancer cells. Tumor subcutaneous transplantation experiment was used to understand the effect of miR-141-3p on paclitaxel resistance in breast cancer in vivo. Results: In the present study, miR-141-3p was found to be highly expressed and associated with poor prognosis in breast cancer. miR-141-3p inhibited Keap1 expression, promoted Nrf2 expression, and facilitated paclitaxel resistance in breast cancer cells. Inhibition of miR-141-3p promoted Keap1 expression, inhibited Nrf2 and its downstream SLC7A11-GSH-GPX4 signaling pathway, as well as promoted ferroptosis in cancer cells, and inhibited paclitaxel and RSL3 resistance. ML385 blocks the effect of miR-141-3p on paclitaxel resistance and ferroptosis resistance in breast cancer cells. In vivo, miR-141-3p mimics promoted paclitaxel resistance, whereas miR-141-3p inhibitors inhibited paclitaxel resistance in breast cancer cells. Conclusion: This work revealed that modulation of the Keap1-Nrf2 signaling pathway by miR-141-3p promoted paclitaxel resistance via regulating ferroptosis in breast cancer cells.

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.

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.

[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.

Corrigendum: TP53 co-mutations in advanced lung adenocarcinoma: comparative bioinformatic analyses suggest ambivalent character on overall survival alongside KRAS, STK11 and KEAP1 mutations.

[This corrects the article DOI: 10.3389/fonc.2024.1357583.].