Transcriptional Regulation by Nrf2

Flavonoids from Polypodium hastatum as neuroprotective agents attenuate cerebral ischemia/reperfusion injury in vitro and in vivo via activating Nrf2

OBJECTIVES

Cerebral ischemic stroke is a leading cause of death worldwide. Though timely reperfusion reduces the infarction size, it exacerbates neuronal apoptosis due to oxidative stress. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor regulating the expression of antioxidant enzymes. Activating Nrf2 gives a therapeutic approach to ischemic stroke.

METHODS

Herein we explored flavonoids identified from Polypodium hastatum as Nrf2 activators and their protective effects on PC12 cells injured by oxygen and glucose deprivation/restoration (OGD/R) as well as middle cerebral artery occlusion (MCAO) mice.

RESULTS

The results showed among these flavonoids, AAKR significantly improved the survival of PC12 cells induced by OGD/R and activated Nrf2 in a Keap1-dependent manner. Further investigations have disclosed AAKR attenuated oxidative stress, mitochondrial dysfunction and following apoptosis resulting from OGD/R. Meanwhile, activation of Nrf2 by AAKR was involved in the protective effects. Finally, it was found that AAKR could protect MCAO mice brains against ischemia/reperfusion injury via activating Nrf2.

DISCUSSION

This investigation could provide lead compounds for the discovery of novel Nrf2 activators targeting ischemia/reperfusion injury.

Dexmedetomidine inhibits ferroptosis through the Akt/GSK3β/Nrf2 axis and alleviates adriamycin-induced cardiotoxicity

The cardiotoxicity of Adriamycin(ADR) limits its clinical application, and its molecular mechanism is not very clear. At present, Dexrazoxane (DXZ) is the only approved drug to prevent ADR-induced cardiotoxicity (DIC), but it also has serious adverse reactions. Therefore, it is a key scientific challenge to find a drug with strong myocardial protection, few adverse reactions and no effect on the anti-tumor effect of ADR. In this study, we established the DIC model in rats. Cardiomyocyte hypertrophy and myocardial fibrosis increased significantly, and MDA and LDH increased significantly in serum. Dexmedetomidine (DEX) is a carbohydrate with multiple biological activities that can significantly improve the above DIC process. Echocardiography confirmed that DEX could reverse the changes of ESV, EDV, EF and FS induced by ADR. In vitro, experiments confirmed that DEX reversed the upregulation of ANP, BNP, MHC and Collagen III protein levels induced by ADR. DEX improves DIC by inhibiting ferroptosis. Erastin, a ferroptosis agonist, confirmed that DEX improved DIC by inhibiting ferroptosis. Mechanically, DEX increases the expression of Nrf2 in the nucleus through the Akt/Gsk3β signalling axis, thereby regulating ferroptosis in cardiomyocytes. In addition, DEX can improve DIC while not affecting the anti-tumor effect of ADR.

Reductive stress and mitochondrial dysfunction: The hidden link in chronic disease

Conventional theories of oxidative stress have long focused on the deleterious consequences of excessive reactive oxygen species (ROS) formation. However, growing evidence reveals that an overload of reducing equivalents-termed reductive stress-may be equally pivotal in driving mitochondrial dysfunction and chronic disease. In this paradigm, abnormally high concentrations of NADH and NADPH create an electron "traffic jam" in the mitochondrial electron transport chain (ETC), leading to partial inhibition or reverse electron flow at upstream complexes. Paradoxically, this hyper-reduced environment promotes ROS generation by increasing electron leakage to molecular oxygen, thereby intensifying oxidative damage to lipids, proteins, and mitochondrial DNA. This review explores the intertwined nature of reductive and oxidative stress, showing how a surplus of reducing equivalents can potentiate metabolic derangements in conditions such as type 2 diabetes, nonalcoholic fatty liver disease, and neurodegenerative disorders. The review discusses common drivers of reductive overload, including chronic hyperglycemia, high-fat diets, and specific dietary patterns-particularly those enriched in polyunsaturated omega-6 fatty acids-that inundate mitochondria with electron donors. The review also highlights emerging evidence that targeted assessment of redox biomarkers (e.g., lactate:pyruvate, β-hydroxybutyrate:acetoacetate ratios) can provide clinically relevant indicators of reductive stress. Finally, the review examines how novel therapeutic strategies can address the underlying reductive imbalance, from rational nutrient modulation to pharmacologic interventions that restore NAD+ levels or optimize ETC flux. Recognizing reductive stress as a critical inflection point in mitochondrial pathophysiology underscores the need for a refined redox framework, one that moves beyond conventional oxidative paradigms to embrace the full spectrum of redox dysregulation in chronic degenerative disease.

Alpha-aminobutyric acid ameliorates diet-induced metabolic dysfunction-associated steatotic liver disease (MASLD) progression in mice via enhancing AMPK/SIRT1 pathway and modulating the gut-liver axis

Alpha-aminobutyric acid (ABA) is a nonproteinogenic amino acid, a metabolite which could be generated from the metabolism of methionine, threonine, serine and glycine or as a gut-microbiome-derived metabolite. Changes in ABA levels have been embroiled in metabolic dysfunction-associated steatotic liver disease (MASLD) intervention studies, but their relation to MASLD pathogenesis remains unclear. Hence, this present study aimed to investigate the effect of oral ABA supplementation on the progression of a high fat/high cholesterol diet (HFD) induced MASLD mice model. ABA was found to remodel the gut microbiome composition and ameliorate MASLD parameters in HFD-fed mice. ABA mitigated HFD-induced gain in liver weight, hepatic steatosis, insulin resistance, serum and hepatic triglyceride levels, and liver cholesterol levels. Modulation of lipid metabolism was observed in the liver, in which expression of proteins and/or genes involved in de novo lipogenesis were suppressed, while those involved in fatty acid oxidation and autophagy were upregulated together with cellular antioxidant capacity, in addition to the enhancement of the AMPK/SIRT1 pathway. ABA reshaped the gut composition by enriching nine bacterial species, including Helicobacter hepaticus, Desulfovibrio sp. G11, Parabacteroides distasonis, and Bacteroides fragilis, while diminishing the abundance of 16 species, which included four Helicobacter species. KEGG pathway analysis of microbial functions found that ABA impeded secondary bile acid biosynthesis - which was reflected in the faecal BA composition analysis. Notably, ABA also inhibited ileal FXR-Fgf15 signaling, allowing for increased hepatic Cyp7a1 expression to eliminate cholesterol buildup in the liver. Overall, our findings indicate that ABA could be used as a promising therapeutic approach for the intervention of MASLD.

Activation, interaction and intimation of Nrf2 pathway and their mutational studies causing Nrf2 associated cancer

Responses against infection trigger several signaling pathways that lead to the production of cytokines, these cytokines release ROS and RNS, damaging DNA and proteins turn into various diseases including cancer. To combat these harmful cytokines, the Nrf2 pathway is activated. The gene NFE2L2 encodes Nrf2, which is divided into seven conserved domains (Neh1-7). The DLG and ETGE motifs, conserved sequences of amino acid in the Neh2 domain of Nrf2, bind to the BTB domain of Keap1. BTB domain promotes Keap1's homodimerization resulting in Cul3 recruitment providing scaffold formation to E2 ubiquitin ligase to form ubiquitin complex. Under normal conditions, this complex regularly degrades Nrf2. However, once the cell is exposed to oxidative stress by ROS interaction with Keap1 resulting in conformational changes that stabilize the Nrf2. Nrf2 further concentrates on the nucleus where it binds with the transcriptional factor to perform the desired genes transcription for synthesizing SOD, GSH, CAT, and various other proteins which reduce the ROS levels preventing certain diseases. To prevent cells from oxidative stress, molecular hydrogen activates the Nrf2 pathway. To activate the Nrf2 pathway, molecular hydrogen oxidizes the iron porphyrin which acts as an electrophile and interacts with Keap1's cysteine residue.

Nuclear factor erythroid 2-related factor improves depression and cognitive dysfunction in rats with ischemic stroke by mediating wolfram syndrome 1

OBJECTIVE

This research aims to investigate the molecular mechanism of nuclear factor erythroid 2-related factor (Nrf2) in improving post-stroke depression and cognitive impairment (PSDCI) by mediating wolfram syndrome 1 (Wfs1).

METHODS

PSDCI rat model was established through middle cerebral artery occlusion (MCAO) and chronic unpredictable mild stress (CUMS). Dimethyl fumarate (DMF) was utilized as an Nrf2 activator, while Wfs1 knockdown lentiviral plasmid was injected into rats for functional investigations. Cognitive function- and depression-relevant parameters were assessed using Morris water maze, forced swimming, sucrose preference, modified neurological severity score (mNSS) tests. The infarct size, pathological changes, and neuronal damage were also evaluated. Additionally, oxidative stress- and inflammatory response-associated proteins were detected by enzyme-linked immunosorbent assay. The binding relation between Nrf2 and the Wfs1 promoter region was analyzed and verified by dual-luciferase and chromatin immunoprecipitation assays.

RESULTS

PSDCI rats had reduced Nrf2 and Wfs1 expression in the hippocampal tissue and inhibited nuclear translocation of Nrf2, showing aggravated oxidative stress and inflammatory responses as well as cognitive dysfunction- and depressive-like symptoms. However, these symptoms in PSDCI rats can be alleviated in response to Nrf2 activation. Furthermore, Nrf2 activation increased the enrichment level of Nrf2 in the Wfs1 promoter region, promoting the transcriptional expression of Wfs1. Wfs1 knockdown partly reversed the effect of Nrf2 activation on the neuronal damage, cognitive dysfunction- and depressive-like symptoms of PSDCI rats.

CONCLUSION

Nrf2 activation can promote Wfs1 expression to reduce neuroinflammation and oxidative stress responses, ultimately alleviating PSDCI in rats.

Effects of dietary Inonotus obliquus fermentation products supplementation on meat quality and antioxidant capacity of finishing pigs

This study aimed to investigate the supplementation of finishing pigs with Inonotus obliquus fermentation products (IOFP) on the meat quality, amino acid and fatty acid composition, muscle fiber characteristics, and antioxidant capacity. Eighteen healthy castrated piglets were randomly divided into three groups and fed a basal diet or supplemented with IOFP (obliquus (Chaga fungus) products fermented for 3 or 7 days (IOFP-3 and IOFP-7) at 8 g per kg feed). The results demonstrated that, compared to the control group, IOFP significantly increased the pH24h from 5.44 to 5.52, a* value from 3.8 to 4.5, crude protein content from 21.9 % to 24.0 %, and intramuscular fat content from 3.03 % to 3.56 %. Additionally, IOFP led to significant increases in the content of total amino acids (TAA), essential amino acids (EAA), flavor amino acids, total polyunsaturated fatty acids (PUFA), and the percentage of unsaturated fatty acids (P < 0.05). Furthermore, it resulted in a significant decrease 45.3 N to 40.3 N in shear force (P < 0.05) in the Longissimus thoracis et lumborum (LTL) muscle of pigs. IOFP-7 supplementation also increased (P < 0.05) the MyHC I mRNA expression and decreased (P < 0.05) MyHC IIb mRNA levels. IOFP not only increased superoxide dismutase (SOD) (P < 0.05) in the serum and muscle tissue, but also decreased the content of MDA (P < 0.05) in serum. IOFP-7 supplementation significantly increased enzyme activity and enhanced the expression of Nuclear factor E2-related factor 2 (Nrf2) and downstream genes (P < 0.05), and reduced MDA and carbonyl contents of pork during storage in high‑oxygen modified atmosphere packaging. In summary, this study demonstrated that dietary IOFP supplementation can effectively improve pork's color and nutritional value, increase slow-twitch fiber percentage, enhance the antioxidant capacity of pigs, prevent lipid and protein oxidation, and improve pork quality.

Hollow mesoporous Prussian blue nanozymes alleviate doxorubicin-induced cardiotoxicity by restraining oxidative stress associated with Nrf2 signaling

Doxorubicin-induced cardiomyopathy (DIC) is a toxic side effect that cannot be ignored during chemotherapy for malignant tumors. In this work, we synthesized a novel nano-chemotherapeutic drug based on Prussian blue nanozyme to alleviate DIC. Hollow mesoporous Prussian blue (HmPB) nanoparticles were used as a carrier to load doxorubicin (DOX) through electrostatic adsorption and obtain a novel chemotherapy drug, HmPB(DOX). In vivo and in vitro chemotherapy efficacy and acute toxicity evaluation experiments were conducted. The results suggest that HmPB(DOX) exhibits pH-responsive characteristics and minimizes the release of DOX from within HmPB(DOX) in cardiomyocytes. However, in the acidic tumor microenvironment, the release of DOX from HmPB(DOX) is notably enhanced. More importantly, HmPB(DOX) possesses excellent antioxidant enzyme activity, effectively clearing DOX-induced reactive oxygen species (ROS) and alleviating oxidative stress in cardiomyocytes. Doxorubicin is pivotal in the chemotherapy of malignant tumors. This study presents novel insights for mitigating the toxic and side effects of DOX, offering new strategies to enhance tolerance to chemotherapy.

Navigating the complexities of neuronal signaling and targets in neurological disorders: From pathology to therapeutics

Neurological disorders arising from structural and functional disruptions in the nervous system present major global health challenges. This review examines the intricacies of various cellular signaling pathways, including Nrf2/Keap1/HO-1, SIRT-1, JAK/STAT3/mTOR, and BACE-1/gamma-secretase/MAPT, which play pivotal roles in neuronal health and pathology. The Nrf2-Keap1 pathway, a key antioxidant response mechanism, mitigates oxidative stress, while SIRT-1 contributes to mitochondrial integrity and inflammation control. Dysregulation of these pathways has been identified in neurodegenerative and neuropsychiatric disorders, including Alzheimer's and Parkinson's diseases, characterized by inflammation, protein aggregation, and mitochondrial dysfunction. Additionally, the JAK/STAT3 signaling pathway emphasizes the connection between cytokine responses and neuroinflammation, further compounding disease progression. This review explores the crosstalk among these signaling networks, elucidating how their disruption leads to neuronal decline. It also addresses the dual roles of these pathways, presenting challenges in targeting them for therapeutic purposes. Despite the potential benefits of activating neuroprotective pathways, excessive stimulation may cause deleterious effects, including tumorigenesis. Future research should focus on designing multi-targeted therapies that enhance the effectiveness and safety of treatments, considering individual variabilities and the obstacles posed by the blood-brain barrier to drug delivery. Understanding these complex signaling interactions is crucial for developing innovative and effective neuroprotective strategies that could significantly improve the management of neurological disorders.

Effects of aged garlic extract on aging?related changes in gastrointestinal function and enteric nervous system cells

Dysmotility of the gastrointestinal (GI) tract is commonly seen in elderly individuals, where it causes significant morbidity and can lead to more severe conditions, including sarcopenia and frailty. Although the precise mechanisms underlying aging-related GI dysmotility are not fully understood, neuronal loss or degeneration in the enteric nervous system (ENS) may be involved. Aged garlic extract (AGE) has been shown to have several beneficial effects in the GI tract; however, it is not known whether AGE can improve GI motility in older animals. The aim of the present study was to examine the effects of AGE on the ENS and gut motility in older mice and elucidate potential mechanisms of action. An AGE-formulated diet was given to 18-month-old female mice for 2 weeks. Organ bath studies and cell culture demonstrated that AGE: i) Altered gut contractile activity; ii) enhanced viability of ENS cells; and iii) exhibited neuroprotective effects on the ENS via reduction in oxidative stress. These findings suggest that AGE could be used to develop novel dietary therapeutics for aging-related GI dysmotility by targeting the associated loss and damage of the ENS.

Curcumin Inhibits Lipopolysaccharide-Induced Inflammation Through the HMGB1/NF-κB Signaling Pathway to Promote the Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells

Curcumin has strong anti-inflammatory properties and promotes the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). The aim of this study was to explore the role and potential molecular mechanism of curcumin in ameliorating osteogenic differentiation disorders caused by inflammation. We used LPS to induce an inflammatory response in hBMSCs. The expression of related mRNAs and proteins was detected by RT‒qPCR, Western blotting, immunofluorescence, and ELISA. The osteogenic differentiation of hBMSCs was detected by alkaline phosphatase (ALP) staining and alizarin red S (ARS) staining. The results showed that after LPS treatment, the levels of the inflammatory cytokines TNF-α, IL-6 and IL-1β in hBMSCs increased, and the activity of ALP, the level of calcium salt deposition and the expression levels of the osteogenic proteins Runx2, COL1, OCN and OPN significantly decreased. The curcumin treatment alleviated this effect. These results indicated that curcumin improved the LPS-induced inflammation and osteogenic differentiation disorder in hBMSCs. Further studies revealed that the therapeutic effect of curcumin was caused by the inhibition of HMGB1 expression. From a mechanistic perspective, curcumin inhibits LPS-induced inflammation by inhibiting the expression of HMGB1, thereby inhibiting the NF-κB pathway and activating the NRF2 pathway, thereby improving the disordered osteogenic differentiation of hBMSCs. In conclusion, curcumin can reduce the LPS-induced inflammation of hBMSCs and ameliorate their osteogenic differentiation disorders.

An insight into nitrite-induced reproductive toxicity and the alleviation of injury by selenomethionine through activation of the Keap1/Nrf2 pathway in Procambarus clarkii

Nitrite (NIT) is one of the most common toxic compounds in aquaculture. However, the effects of NIT exposure on the reproductive capabilities of aquatic animals remain largely unknown. This study explored the consequences of NIT exposure on the ovarian tissues of Procambarus clarkii and revealed that it significantly reduced ATP content and gonadosomatic index (GSI), causing metabolic imbalance, reactive oxygen species (ROS) accumulation, increased oxidative stress, and altered antioxidant enzyme activity. Pathological investigation revealed a decrease in the number of oogonia and oocytes, as well as an increase in vacuolated and apoptotic cells in the ovary. Differentially expressed genes (DEGs) and gene set enrichment analysis (GSEA) revealed that genes related to oxidative stress, apoptosis, and autophagy were significantly upregulated, whereas genes involved in ovarian development and energy metabolism were downregulated. These findings suggested that NIT exposure not only caused oxidative stress and abnormal energy metabolism, but also activated autophagy and apoptosis in the ovarian cells. In addition, the Nrf2/Keap1 (nuclear factor erythroid 2-related factor 2/Kelch-like ECH-associated protein 1) signaling pathway was found to be activated. Nrf2 knockdown inhibited antioxidant, apoptotic, and autophagy activities while increasing the expression of genes related to reproduction and nutrient metabolism. Selenomethionine (Se-Met) treatment alleviated NIT exposure-induced ovarian damage by elevating antioxidant capacity, superoxide dismutase, and catalase activities and reducing the levels of H2O2, malondialdehyde, glutathione, and ROS. In addition, Se-Met improved the anti-inflammatory and antioxidant stress responses by activating the Nrf2/Keap1 pathway and attenuating NIT-induced ovarian toxicity. Overall, this study provides a novel approach for maintaining ovarian homeostasis after NIT exposure.

Diroximel Fumarate Acts Through Nrf2 to Attenuate Methylglyoxal-Induced Nociception in Mice and Decrease ISR Activation in DRG Neurons

Diabetic neuropathic pain is associated with elevated plasma levels of methylglyoxal (MGO). MGO is a metabolite of glycolysis that causes pain hypersensitivity in mice by stimulating the phosphorylation of eukaryotic initiation factor 2α (p-eIF2α) and subsequently activating the integrated stress response (ISR). We first established that Zucker diabetic fatty rats have enhanced MGO signaling, engage ISR, and develop pain hypersensitivity. Since nuclear factor erythroid 2-related factor 2 (Nrf2) regulates the expression of antioxidant proteins that neutralize MGO, we hypothesized that fumarates, like diroximel fumarate (DRF), will stimulate Nrf2 signaling, and prevent MGO-induced ISR and pain hypersensitivity. DRF (100 mg/kg) treated animals were protected from developing MGO (20 ng) induced mechanical and cold hypersensitivity. Mechanistically, DRF treatment protected against MGO-induced increase in p-eIF2α levels in the sciatic nerve and reduced loss of intraepidermal nerve fiber density. Using Nrf2 knockout mice, we demonstrate that Nrf2 is necessary for the antinociceptive effects of DRF. Cotreatment of MGO (1 µmol/L) with monomethyl fumarate (10, 20, and 50 µmol/L), the active metabolite of DRF, prevented ISR in both mouse and human dorsal root ganglia neurons. Our data show that targeting Nrf2 with DRF is a strategy to potentially alleviate pain associated with elevated MGO levels.

ARTICLE HIGHLIGHTS

Exploring the links between polyphenols, Nrf2, and diabetes: A review

Diabetes mellitus, a complex metabolic disorder, is marked by chronic hyperglycemia that drives oxidative stress and inflammation, leading to complications such as neuropathy, retinopathy, and cardiovascular disease. The Nrf2 pathway, a key regulator of cellular antioxidant defenses, plays a vital role in mitigating oxidative damage and maintaining glucose homeostasis. Dysfunction of Nrf2 has been implicated in the progression of diabetes and its related complications. Polyphenols, a class of plant-derived bioactive compounds, have shown potential in modulating the Nrf2 pathway. Numerous compounds have been found to activate Nrf2 through mechanisms including Keap1 interaction, transcriptional regulation, and epigenetic modification. Preclinical studies indicate their ability to reduce reactive oxygen species (ROS), improve insulin sensitivity, and attenuate inflammation in diabetic models. Clinical trials with certain polyphenols, such as resveratrol, have demonstrated improvements in glycemic parameters, though results remain inconsistent. While polyphenols show promise as a component of non-pharmacological approaches to diabetes management, challenges such as bioavailability, individual variability in response, and limited clinical evidence highlight the need for further investigation. Continued research could enhance understanding of their mechanisms and improve their practical application in mitigating diabetes-related complications.

Redox modulation via a synthetic thiol compound reshapes energy metabolism in endothelial cells and ameliorates angiogenic expression in a co-culture study with activated macrophages

The vascular endothelium is the first interface exposed to circulating compounds and oxidative as well as pro-inflammatory stimuli. Nowadays, cysteine pro-drugs are emerging as new and potential therapies in cardiovascular and inflammatory diseases due to their cytoprotective effects. In this study, the effects of redox modulation by a synthetic thiol compound, i.e., I-152, a precursor of N-acetylcysteine (NAC) and cysteamine (MEA), were evaluated after 6 h and 24 h treatment on human umbilical cord endothelial cell (HUVECs) energy metabolism. Following I-152 treatment, higher cysteine and glutathione (GSH) content were detected via HPLC, in concomitance with I-152 derivatives, i.e., NAC and MEA. Untargeted metabolomics confirmed GSH upregulation and NAC presence in addition to I-152 itself and other metabolites, such as dithiol compound (NACMEAA) and triacetylated I-152. Mass spectrometry revealed that I-152 boosted ATP production, specifically through the mitochondrial OXPHOS, as determined via Seahorse assay without inducing oxidative stress. Additionally, I-152 treatment of HUVECs before co-culture with LPS-stimulated macrophages provided GSH and cysteine sustainment and attenuated the transcription of adhesion molecules as well as iNOS expression. Identifying the impact of redox regulation in physiological conditions and the possible metabolic targets could aid the application of novel thiol-based therapeutics.

Endothelial SHP-1 regulates diabetes-induced abnormal collateral vessel formation and endothelial cell senescence

BACKGROUND

Critical limb ischemia is a major cause of peripheral arterial disease and morbidity affecting patients with diabetes. Diabetes-induced premature senescence of endothelial cells (EC) has been proposed as a mechanism leading to impaired ischemia-driven angiogenesis. We showed that hyperglycemia induced expression of the protein tyrosine phosphatase SHP-1, which reduced angiogenic factor activity in ischemic muscle of diabetic mice. Here, we evaluate the impact of SHP-1 deletion on EC function and senescence.

METHODS

Ligation of the femoral artery was performed in nondiabetic (NDM) and 3 months diabetic (DM) mice with EC-specific deletion of SHP-1. Cell migration, proliferation and protein expression were evaluated in EC exposed to normal (NG) or high glucose (HG) concentrations. Gastrocnemius and tibial artery of patients with diabetes were collected and analyzed.

RESULTS

Blood flow reperfusion and limb function were reduced by 43 % and 82 %, respectively in DM mice as compared to NDM mice. EC-specific deletion of SHP-1 in DM mice restored blood flow reperfusion by 60 %, and limb function by 86 %, while capillary density was similar to NDM mice. Moreover, ablation of SHP-1 in EC prevented diabetes-induced expression of the senescence markers p53 and p21 and counteracted Nrf2 downregulation. In EC, elevated expression of beta-galactosidase, p21 and p53, and suppression of Nrf2 and VEGF actions were observed in EC exposed to HG levels and human muscle and artery of patients with diabetes, effects that were reversed by overexpression of dominant negative SHP-1.

CONCLUSION

SHP-1 in EC is a central effector of diabetes-induced senescence and induces aberrant collateral vessel formation and blood flow reperfusion. Reduced SHP-1 expression counteracts these pathologic features.

Bacteria escape macrophage-mediated phagocytosis via targeting apurinic/apyrimidinic endonuclease 1 in sepsis

Sepsis is a serious disease resulting from an imbalanced host response to bacterial infection, in which macrophages play a crucial role. However, the connection between bacterial infection and macrophage phagocytosis remains largely unknown. Here, we provide evidence supporting the role of apurinic/apyrimidinic endonuclease 1 (APE1) in regulating bacterial infection and macrophage immune function during sepsis. We confirmed down-regulation of APE1 expression in macrophages from both in vitro and in vivo septic models. APE1 deficiency significantly increases the mortality rate of septic mice. Experiments using fluorescent latex beads and Escherichia coli uptake demonstrated that reduced APE1 levels inhibit macrophage phagocytosis. Specifically, APE1 deficiency activates GSK3β, leading to the ubiquitination and subsequent proteasomal degradation of NRF2, thereby reducing the expression of phagocytic receptors. Additionally, APE1 participates in the process through its redox function. In conclusion, APE1 is a critical protein involved in the evasion of macrophage phagocytosis by bacteria. Our study suggests that targeting the APE1/NRF2 axis could serve as a promising therapeutic strategy for sepsis and bacterial infections.

Endoplasmic reticulum stress inhibition preserves mitochondrial function and cell survival during the early onset of isoniazid-induced oxidative stress

A comprehensive understanding of isoniazid (INH)-mediated hepatotoxic effects is essential for developing strategies to predict and prevent severe liver toxicity in tuberculosis treatment. In this study, we used multi-omics profiling in vitro to investigate the toxic effects of INH, revealing significant involvement of endoplasmic reticulum (ER) stress, mitochondrial impairment, redox imbalance, and altered metabolism. Additional analysis using transcriptomics data from repeated time-course INH treatments on human hepatic microtissues revealed that cellular responses to ER stress and oxidative stress happened prior to disturbances in mitochondrial complexes. Mechanistic validation studies using time-lapse measurements of cytosolic and mitochondrial reactive oxygen species (ROS) revealed that INH initially triggered cytosolic ROS increasement and Nrf2 signaling pathway activation before mitochondrial ROS accumulation. Molecular imaging showed that INH subsequently disrupted mitochondrial function by impairing respiratory complexes I-IV and caused mitochondrial membrane proton leakage without affecting mitochondrial complex V, leading to mitochondrial depolarization and reduced ATP production. These disturbances enhanced mitochondrial fission and mitophagy. Our findings highlight the potential of inhibiting ER stress during early INH exposure to mitigate cytosolic and mitochondrial oxidative stress. We also revealed the critical role of Nrf2 signaling in protecting hepatocytes under INH-induced oxidative stress by maintaining redox homeostasis and enabling metabolic reprogramming through regulating antioxidant gene expression and cellular lipid abundance. Alternative antioxidant pathways, including selenocompound metabolism, HIF-1 signaling, and the pentose phosphate pathway, also responded to INH-induced oxidative stress. Collectively, our study emphasizes the importance of ER stress, redox imbalance, metabolic changes, and mitochondrial dysfunction that underlie INH-induced hepatotoxicity.

Targeting epigenetic and post-translational modifications of NRF2: key regulatory factors in disease treatment

Nuclear factor erythroid 2-related factor 2 (NRF2) is a key transcription factor involved in regulating cellular antioxidant defense and detoxification mechanisms. It mitigates oxidative stress and xenobiotic-induced damage by inducing the expression of cytoprotective enzymes, including HO-1 and NQO1. NRF2 also modulates inflammatory responses by inhibiting pro-inflammatory genes and mediates cell death pathways, including apoptosis and ferroptosis. Targeting NRF2 offers potential therapeutic avenues for treating various diseases. NRF2 is regulated through two principal mechanisms: post-translational modifications (PTMs) and epigenetic alterations. PTMs, including phosphorylation, ubiquitination, and acetylation, play a pivotal role in modulating NRF2's stability, activity, and subcellular localization, thereby precisely controlling its function in the antioxidant response. For instance, ubiquitination can lead to NRF2 degradation and reduced antioxidant activity, while deubiquitination enhances its stability and function. Epigenetic modifications, such as DNA methylation, histone modifications, and interactions with non-coding RNAs (e.g., MALAT1, PVT1, MIR4435-2HG, and TUG1), are essential for regulating NRF2 expression by modulating chromatin architecture and gene accessibility. This paper systematically summarizes the molecular mechanisms by which PTMs and epigenetic alterations regulate NRF2, and elucidates its critical role in cellular defense and disease. By analyzing the impact of PTMs, such as phosphorylation, ubiquitination, and acetylation, as well as DNA methylation, histone modifications, and non-coding RNA interactions on NRF2 stability, activity, and expression, the study reveals the complex cellular protection network mediated by NRF2. Furthermore, the paper explores how these regulatory mechanisms affect NRF2's roles in oxidative stress, inflammation, and cell death, identifying novel therapeutic targets and strategies. This provides new insights into the treatment of NRF2-related diseases, such as cancer, neurodegenerative disorders, and metabolic syndrome. This research deepens our understanding of NRF2's role in cellular homeostasis and lays the foundation for the development of NRF2-targeted therapies.

Ferroptosis: An Energetic Villain of Age-Related Macular Degeneration

Iron homeostasis plays an important role in maintaining cellular homeostasis; however, excessive iron can promote the production of reactive oxygen species (ROS). Ferroptosis is iron-dependent programmed cell death that is characterized by excessive iron accumulation, elevated lipid peroxides, and the overproduction of ROS. The maintenance of iron homeostasis is contingent upon the activity of the transferrin receptor (TfR), ferritin (Ft), and ferroportin (FPn). In the retina, iron accumulation and lipid peroxidation can contribute to the development of age-related macular degeneration (AMD). This phenomenon can be explained by the occurrence of the Fenton reaction, in which the interaction between divalent iron and hydrogen peroxide leads to the generation of highly reactive hydroxyl radicals. The hydroxyl radicals exhibit a propensity to attack proteins, lipids, nucleic acids, and carbohydrates, thereby instigating oxidative damage and promoting lipid peroxidation. Ultimately, these processes culminate in cell death and retinal degeneration. In this context, a comprehensive understanding of the exact mechanisms underlying ferroptosis may hold significant importance for developing therapeutic interventions. This review summarizes recent findings on iron metabolism, cellular ferroptosis, and lipid metabolism in the aging retina. We also introduce developments in the therapeutic strategies using iron chelating agents. Further refinements of these knowledges would deepen our comprehension of the pathophysiology of AMD and advance the clinical management of degenerative retinopathy. A comprehensive search strategy was employed to identify relevant studies on the role of ferroptosis in AMD. We performed systematic searches of the PubMed and Web of Science electronic databases from inception to the current date. The keywords used in the search included "ferroptosis", "AMD", "age-related macular degeneration", "iron metabolism", "oxidative stress", and "ferroptosis pathways". Peer-reviewed articles, including original research, reviews, meta-analyses, and clinical studies, were included in this paper, with a focus on the molecular mechanisms of ferroptosis in AMDs. Studies not directly related to ferroptosis, iron metabolism, or oxidative stress in the context of AMD were excluded. Furthermore, articles that lacked sufficient data or were not peer-reviewed (e.g., conference abstracts, editorials, or opinion pieces) were not considered.

Evaluated NSUN3 in reticulocytes from HbH-CS disease that reflects cellular stress in erythroblasts

Hemoglobin H Disease-Constant Spring (HbH-CS) represents a severe variant of α-thalassemia characterized by a fundamental pathological mechanism involving inadequate synthesis of α-globin chains. This deficiency results in the formation of unstable Hemoglobin H (HbH) due to the aggregation of free β-globin chains, which subsequently induces an imbalance in oxidative stress within erythrocytes. This imbalance leads to an abnormal accumulation of reactive oxygen species (ROS), which in turn promotes lipid peroxidation, culminating in the production of malondialdehyde (MDA) and a significant depletion of glutathione (GSH). Concurrently, Nrf2 is translocated to the nucleus, where it activates the antioxidant response element (ARE) to mitigate cellular stress. Here, we report that NSUN3 (which, together with ALKBH1, maintains mitochondrial function through m5C→f5C modification) is abnormally overexpressed in reticulocytes from patients with HbH-CS, and an in vitro cellular model of NSUN3 overexpression/silencing was constructed using K562 cells, which have the potential for erythroid lineage differentiation and retain an intact cluster of bead protein genes. Functional assays indicated that the overexpression of NSUN3 significantly intensified the accumulation of intracellular ROS and MDA, led to a reduction in GSH levels, and diminished the overall cellular antioxidant capacity (T-AOC). This may be due to ROS accumulation resulting from inhibition of mitochondrial respiratory chain complex I, II, and IV synthesis through aberrant m5C→f5C modification. In addition, NSUN3 overexpression further exacerbates oxidative stress by inhibiting the phosphorylation of Nrf2 hindering its translocation into the nucleus and weakening the cellular antioxidant system. Moreover, we also observed that NSUN3 overexpression exacerbated intracellular DNA damage and inhibited cellular value-added activity, and silencing NSUN3 showed the opposite result. Our research offers initial insights into the molecular mechanisms through which NSUN3 modulates oxidative stress in erythrocytes via its role in epigenetic modifications. These findings contribute to a deeper understanding of the clinical management of patients with Hb H-CS.

Discovery of β-amino acid substituted naphthalene sulfonamide derivatives as potent Kelch-like ECH-associated protein 1-nuclear factor erythroid 2-related factor 2 (Keap1-Nrf2) protein-protein interaction inhibitors for ulcerative colitis management

The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) is a key regulator of cellular defense system against oxidative insults. Directly inhibiting the Kelch-like ECH-associated protein 1 (Keap1)-Nrf2 protein-protein interaction (PPI) has emerged as a promising approach to activate Nrf2 for the treatment of diseases associated with oxidative stress. Herein, we identified β-amino acids as privileged structural fragments for designing novel naphthalene sulfonamide-based Keap1-Nrf2 PPI inhibitors. Comprehensive structure-activity relationship (SAR) exploration identified compound 19 as the optimal inhibitor with an IC50 of 0.55 μM for disrupting the Keap1-Nrf2 interaction and a Kd of 0.50 μM for binding to Keap1. Further studies demonstrated that 19 effectively activated the Nrf2-regulated cytoprotective system and provided protective effects against dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in both in vitro and in vivo models. These findings highlight the potential of β-amino acid substituted naphthalene sulfonamide Keap1-Nrf2 inhibitor 19 as a prospective therapeutic agent for UC via Keap1 targeting.

Glutathione attenuates diesel exhaust-induced lung epithelial injury via NF-κB/Nrf2/GPX4-mediated ferroptosis

Diesel exhaust (DE) emissions pose a significant threat to public health. This study linked DE-mediated reactive oxygen species (ROS) and ferroptosis with lung epithelial disruption, also the protective potential of exogenous glutathione (GSH) administration was investigated. C57BL/6 mice were divided into three groups: filtered air (control), DE exposed, and DE+GSH (administered intranasally on alternate days). Airway hyperresponsiveness (AHR), lung tissues, and bronchoalveolar lavage fluid (BALF) were used for analysis. DE exposure significantly impaired lung function parameters as shown by AHR. Elevated ROS depleted the GSH/GSSG ratio and suppressed Nrf2 activity, disrupting antioxidant defense mechanisms, which were restored by GSH administration. DE-induced ROS acted as a key driver of ferroptosis, characterized by suppressed SLC7411 expression thereby decreased GSH synthesis and GPX-4 activity, inducing lipid peroxidation. Ferroptosis was significantly mitigated by increased GSH pool, which restored GPX-4 levels and reduced lipid peroxidation. Concurrently, DE induced ROS promoted DNA damage and apoptosis in lung epithelial cells wherein GSH treatment preserved cell survival in DE exposed mice. The heightened DE-associated ROS further amplified inflammation, as shown by increased cytokines (TNF-α, IL-6, TSLP, IL-33) and P-NF-κB activation. Activated inflammatory cascade disrupted tight junction proteins (claudins, occludin), resulted in weakened epithelial barrier and increased permeability. Lung barrier disruption was evidenced by transmission electron microscopy and immunohistochemistry, corroborated with elevated albumin levels. GSH effectively restored tight junction integrity and preserved barrier function in DE+GSH mice lungs. In conclusion, DE-induced oxidative stress and ferroptosis-triggered inflammation compromised epithelial barrier promoting lung injury. Exogenous GSH administration showed potential in restoring DE-associated lung damage.

Methyl isoeugenol suppresses NLRP3 inflammasome-mediated pyroptosis via activation of Nrf2/NQO1/HO-1 signaling in cerebral ischemia-reperfusion injury

Microglial neuroinflammation is considered to be a vital injury factor aggravating ischemia-reperfusion (I/R) injury on the progression of cerebral ischemic stroke. Mounting evidences have verified the effect of pyroptosis mediated by NLRP3 inflammasome on modulating microglial phenotype, and maintaining the microglial M1/M2 phenotype balance could be a novel target to ameliorate cerebral I/R injury. Herein, we focused on the anti-neuroinflammatory effect of methyl isoeugenol, a bioactive compound isolated from Acorus tatarinowii Schott, on nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated NLRP3 inflammasome in vivo or in vitro. The results showed that methyl isoeugenol reduced cerebral infarct volume, modulated microglia M1/M2 phenotypes, and protected against NLRP3 inflammasome-primed pyroptosis. Mechanistically, methyl isoeugenol increased the nuclear translocation of Nrf2 and decreased that of NF-κB, and consequently, upregulated cellular antioxidants (HO-1 and NQO1), with the increased expression of antioxidant enzymes SOD and the decreased expression of lipid peroxidation MDA. These findings suggest that Nrf2 may serve as a vital target for the protective effect of methyl isoeugenol, making methyl isoeugenol as a promising anti-neuroinflammatory agent for NLRP3 inflammasome mediated microglial neuroinflammation in I/R injury.

7β-(3-ethyl-cis-crotonoyloxy)-1α-(2-methylbutyryloxy)-3,14-dehydro-Z-notonipetranone (ECN) attenuates inflammation and oxidative stress via MAPK, and Nrf2/HO-1 signaling in Traumatic brain injury

Traumatic brain injury (TBI) is an acquired neurological insult that has become a major cause of mortality.Hence, immediate and appropriate medical attention is essential. The present study investigated the neuroprotective effect of 7β-(3-ethyl-cis-crotonoyloxy)-1α-(2-methylbutyryloxy)-3,14-dehydro-Z-notonipetranone (ECN), a sesquiterpenoid against a weight drop model of traumatic brain injury (TBI). During the in-vitro analysis, ECN demonstrated neuroprotective potential by remarkably improving the cell viability and also provided significant protection in case of nitric oxide-evoked oxidative stress in HT22 cells. The administration of ECN significantly improved the neurological severity score, and mechanical/periorbital allodynia following TBI, when compared with the TBI-group. The level of brain edema and blood-brain barrier (BBB) disruption were also significantly reduced by ECN treatment. ECN also restored constitutional changes in the protein/lipid profile; simultaneous with histological changes in the brain in contrast to the TBI-group. It significantly ameliorated neuronal loss and also minimized the intracerebral hemorrhages arising from traumatic insult. ECN exhibited potent anti-inflammatory effects, by altering the expression of extracellular-signal-regulated kinase (ERK), p38, and activating protein-1 (AP-1) proteins. It also exhibited antioxidant effects by increasing the production levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). Furthermore, ECN also produced an anti-apoptotic effect by downregulation of caspase3 and upregulation of B-cell lymphoma 2 (Bcl-2). It also increased the levels of antioxidants while reducing the levels of oxidative stress and inflammatory markers in comparison to the TBI-group. In short, it was concluded that ECN exhibited protective anti-inflammatory, antioxidant, and anti-apoptotic effects against trauma-induced brain injury.

Effects of exercise on different antioxidant enzymes and related indicators: a systematic review and meta-analysis of randomized controlled trials

Numerous studies on the effects of exercise on antioxidant enzymes have generally concluded that regular exercise positively impacts antioxidant enzyme activity. However, some studies suggest that regular exercise may have no effect on antioxidant enzymes or could even negatively impact them. This suggests that other potential factors may influence antioxidant enzyme activity. Therefore, this study synthesizes existing literature on the effects of exercise interventions on antioxidant enzymes and employs subgroup analysis to identify factors that may influence exercise outcomes, offering insights for individuals aiming to enhance antioxidant capacity through exercise. A systematic review and meta-analysis were performed on exercise intervention studies measuring changes in blood antioxidant enzymes. This study was registered in PROSPERO (identifier: CRD 42023477230). (1) Exercise did not significantly increase superoxide dismutase (SOD) activity in women. (2) In individuals over 45 years of age, exercise did not significantly improve SOD activity or total antioxidant capacity (T-AOC) levels. (3) Regardless of exercise type, trends in SOD and catalase (CAT) activity were similar; however, only resistance exercise increased glutathione peroxidase (GPX) activity and reduced thiobarbituric Acid Reactive Substances (TBARS) levels. (4) High-intensity exercise significantly reduced CAT levels but did not significantly increase GPX levels. (5) Exercise interventions lasting more than 16 weeks showed no significant impact on the activity of SOD, CAT, or GPX. 6. Regular exercise at least three times per week significantly increased SOD and GPX activity and had a notable impact on T-AOC and TBARS levels. This study found that exercise significantly enhanced the activity of most antioxidant enzymes and overall antioxidant capacity. Moderate-to-low intensity exercise, performed at least three times per week for more than 16 weeks, demonstrated the greatest efficacy in enhancing antioxidant enzyme activity. Notably, we also found that women may need to exert more effort than men to achieve increases in antioxidant enzyme activity.

High-Resolution Tracking of Aging-Related Small Molecules: Bridging Pollutant Exposure, Brain Aging Mechanisms, and Detection Innovations

Brain aging is a complex process regulated by genetic, environmental, and metabolic factors, and increasing evidence suggests that environmental pollutants can significantly accelerate this process by interfering with oxidative stress, neuroinflammation, and mitochondrial function-related signaling pathways. Traditional studies have focused on the direct damage of pollutants on macromolecules (e.g., proteins, DNA), while the central role of senescence-associated small molecules (e.g., ROS, PGE2, lactate) in early regulatory mechanisms has been long neglected. In this study, we innovatively proposed a cascade framework of "small molecule metabolic imbalance-signaling pathway dysregulation-macromolecule collapse", which reveals that pollutants exacerbate the dynamics of brain aging through activation of NLRP3 inflammatory vesicles and inhibition of HIF-1α. Meanwhile, to address the technical bottleneck of small molecule spatiotemporal dynamics monitoring, this paper systematically reviews the cutting-edge detection tools such as electrochemical sensors, genetically encoded fluorescent probes and antioxidant quantum dots (AQDs). Among them, AQDs show unique advantages in real-time monitoring of ROS fluctuations and intervention of oxidative damage by virtue of their ultra-high specific surface area, controllable surface modification, and free radical scavenging ability. By integrating multimodal detection techniques and mechanism studies, this work provides a new perspective for analyzing pollutant-induced brain aging and lays a methodological foundation for early intervention strategies based on small molecule metabolic networks.

Dexmedetomidine Promotes Angiogenesis After Ischemic Stroke Through the NRF2/HO-1/VEGF Pathway

Neurological dysfunction following stroke presents a significant challenge for patients. Recent studies suggest that angiogenesis can improve neurological function and enhance neuronal survival after ischemic stroke. Dexmedetomidine exhibits neuroprotective effects through various mechanisms; therefore, this study aimed to investigate whether it promotes angiogenesis and improves neurological function after stroke. A mouse model of ischemic stroke was developed by embolizing the middle cerebral arteries. Neurological function was assessed using scoring methods, the water maze test, and histological analyses, including Nissl and hematoxylin and eosin staining, to evaluate neuronal survival in the ischemic penumbra. Angiogenesis was observed through immunofluorescence staining, whereas pathway protein expression was analyzed via western blotting. Additionally, a model of oxygen-glucose deprivation/reoxygenation was established in mouse cerebral microvascular cells to conduct angiogenesis-related experiments. Dexmedetomidine reduced cerebral infarction size, alleviated neurological damage, promoted angiogenesis in the ischemic penumbra, and decreased neuronal death through the Nrf2/HO-1/VEGF pathway. However, these neuroprotective effects were reversed by the NRF2 inhibitor ML385. In vitro, dexmedetomidine enhanced the proliferation, migration, and tube-formation of cerebral microvascular cells in mice. ML385 also reversed the protective effects of dexmedetomidine against hypoxia and glucose deprivation-induced axonal damage. Dexmedetomidine enhances angiogenesis, reduces neuronal damage, and promotes cerebral microvascular cell migration and tube formation in the ischemic penumbra of an ischemic stroke mouse model through the Nrf2/HO-1/VEGF pathway.

The main active components of Prunella vulgaris L. alleviate myocardial ischemia-reperfusion injury by inhibiting oxidative stress and ferroptosis via the NRF2/GPX4 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Prunella vulgaris L. (PV) is a widely distributed medicinal and edible plant used in traditional Chinese medicine for its anti-tumor, anti-inflammatory, anti-oxidant, hypoglycemic, and anti-hypertensive effects. Despite the numerous studies reporting on its cardiovascular protective effects, it is still unknown whether PV could relieve myocardial ischemia-reperfusion (MI/R) injury.

AIM OF THE STUDY

To investigate the effects of PV on MI/R injury and explore the underlying mechanism of action.

MATERIALS AND METHODS

Sprague-Dawley rats were orally administrated with the aqueous extract of P. vulgaris for 7 days before MI/R injury was induced. Echocardiography, infarct staining, and TUNEL assay were used to evaluate the protective effect of P. vulgaris. H2O2- and RSL3-stimulated H9C2 rat myocardial cells were used to explore the underlying mechanism. Ultra-high-performance liquid chromatography/mass spectrometer analysis was used to identify the chemical constituents of P. vulgaris. AutoDock software was used to predict the binding affinity and the interactions between the main active compounds and Keap1. Nuclear factor erythroid 2-related factor 2 (Nrf2) knock-out mice were used to confirm whether the protective effect of P. vulgaris was mediated by Nrf2.

RESULTS

P. vulgaris improved left ventricular systolic function and decreased the myocardial infarct area, which alleviated the MI/R injury. PV also increased the level of Nrf2 proteins and promoted the expression of HO-1, SOD, and GSH, thus upregulating the activity of the antioxidant system. The molecular docking simulations indicated that rosmarinic acid, salviaflaside, ursolic acid, and protocatechuic acid from P. vulgaris could strongly bind to Keap1 protein with good binding affinities. Additionally, ursolic acid was found to elevate NRF2 protein levels and promote NRF2 nuclear translocation. Moreover, the cardiac protective effect of PV or ursolic acid disappeared in NRF2-/- mice, indicating that this protective effect was mediated by NRF2. Also, PV increased the protein levels of GPX4 in MI/R rat or mice models, and this upregulation disappeared in NRF2-/- mice. Results from the RSL-3-induced ferroptosis H9C2 cell model showed that ursolic acid was the main active component of PV that protects cardiomyocytes against ferroptosis.

CONCLUSIONS

Collectively, the findings indicate that PV could alleviate MI/R injury by inhibiting oxidative stress and ferroptosis via the NRF2/GPX4 pathway, and ursolic acid is the main active component responsible for mediating both antioxidative and anti-ferroptosis effects, suggesting its potential use as a therapeutic agent against MI/R injury.

The Ancestral KEAP1-NRF Pathway in Amphioxus Branchiostoma japonicum: Implications for the Evolution of Antioxidant Defense System

The Kelch-like ECH-associated protein 1 (KEAP1)/Nuclear factor E2-related factor 2 (NRF2) pathway is a key mechanism that responds to oxidative stress and xenobiotic stimuli in vertebrates. However, knowledge of its evolutionary origins remains limited. In this study, we identify the ancestral homologues of KEAP1 and NRF (BjKEAP1 and BjNRF) in cephalochordate amphioxus (Branchiostoma japonicum). BjNRF uniquely combines the feature domains of vertebrates NRF1 and NRF2, marking it as an evolutionary intermediate. High expression levels of Bjkeap1 and Bjnrf in the gill, hepatic cecum, and intestine highlight their roles in environmental defense at key interface tissues. Functional studies reveal that BjKEAP1 regulates the cytoplasmic localization of BjNRF. Typical NRF2 activator sulforaphane (SFN) induces its nuclear translocation and significantly elevates the transcriptional expression of BjNRF and phase II detoxification enzymes. Moreover, exposure to the environmental toxin Benzo[a]pyrene (BaP) activates this stress response system. These findings bridge critical gaps in our understanding of this pathway in basal chordates and offer new insights into the evolutionary trajectory of the KEAP1-NRF system. Furthermore, this study highlights crucial implications for the conservation of amphioxus in deteriorating marine environments.

Induction of Cuproptosis by Dichloromethane Extract From Patrinia scabiosaefolia Fisch on K562 Cells

Cuproptosis is a newly identified form of cell death that relies on copper (Cu) ionophores to transport Cu into cancer cells. As a perennial herb, Patrinia scabiosaefolia Fisch (PS) has garnered significant attention owing to its analgesic, anti-inflammatory, antibacterial, and antitumor properties. Previous research has shown that the extract from PS (DEPS) can inhibit the growth of leukemia cell lines. However, the specific mechanism of its anti-leukemic effect has not been fully clarified. Therefore, this study was conducted to investigate the molecular mechanism of cuproptosis in the treatment of leukemia with DEPS. Our results demonstrated that DEPS up-regulated SLC31A1 and down-regulated ATP7B expression, which increased intracellular copper concentration, down-regulated FDX1, influenced the lipoylation of DLAT and DLD, and subsequently increased the expression of the stress protein HSP70 and the expression of PDHA1, inducing copper death in K562 cells. In addition, we investigated the toxicity of DEPS in vivo and demonstrated its low in vivo toxicity and adequate in vivo safety. In conclusion, our results suggest that DEPS may induce cuproptosis in cells, offering valuable insights for the future application of PS in leukemia treatment.

Cell-Free DNA (cfDNA) Regulates Metabolic Remodeling in the ES-2 Ovarian Carcinoma Cell Line, Influencing Cell Proliferation, Quiescence, and Chemoresistance in a Cell-of-Origin-Specific Manner

Background: The cell-free DNA (cfDNA) is an extracellular fragmented DNA found in body fluids in physiological and pathophysiological contexts. In cancer, cfDNA has been pointed out as a marker for disease diagnosis, staging, and prognosis; however, little is known about its biological role. Methods: The role of cfDNA released by ES-2 ovarian cancer cells was investigated, along with the impact of glucose bioavailability and culture duration in the cfDNA-induced phenotype. The effect of cfDNA on ES-2 cell proliferation was evaluated by proliferation curves, and cell migration was assessed through wound healing. We explored the impact of different cfDNA variants on ES-2 cells' metabolic profile using nuclear magnetic resonance (NMR) spectroscopy and cisplatin resistance through flow cytometry. Moreover, we assessed the protein levels of DNA-sensitive Toll-like receptor 9 (TLR9) by immunofluorescence and its colocalization with lysosome-associated membrane protein 1 (LAMP1). Results: This study demonstrated that despite inducing similar effects, different variants of cfDNA promote different effects on cells derived from the ES-2 cell line. We observed instant reactions of adopting the metabolic profile that brings back the cell functioning of more favorable culture conditions supporting proliferation and resembling the cell of origin of the cfDNA variant, as observed in unselected ES-2 cells. However, as a long-term selective factor, certain cfDNA variants induced quiescence that favors the chemoresistance of a subset of cancer cells. Conclusions: Therefore, different tumoral microenvironments may generate cfDNA variants that will impact cancer cells differently, orchestrating the disease fate.

Sulforaphane protects developing neural networks from VPA-induced synaptic alterations

Prenatal brain development is particularly sensitive to chemicals that can disrupt synapse formation and cause neurodevelopmental disorders. In most cases, such chemicals increase cellular oxidative stress. For example, prenatal exposure to the anti-epileptic drug valproic acid (VPA), induces oxidative stress and synaptic alterations, promoting autism spectrum disorders (ASD) in humans and autism-like behaviors in rodents. Using VPA to model chemically induced ASD, we tested whether activation of cellular mechanisms that increase antioxidant gene expression would be sufficient to prevent VPA-induced synaptic alterations. As a master regulator of cellular defense pathways, the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) promotes expression of detoxification enzymes and antioxidant gene products. To increase NRF2 activity, we used the phytochemical and potent NRF2 activator, sulforaphane (SFN). In our models of human neurodevelopment, SFN activated NRF2, increasing expression of antioxidant genes and preventing oxidative stress. SFN also enhanced expression of genes associated with synapse formation. Consistent with these gene expression profiles, SFN protected developing neural networks from VPA-induced reductions in synapse formation. Furthermore, in mouse cortical neurons, SFN rescued VPA-induced reductions in neural activity. These results demonstrate the ability of SFN to protect developing neural networks during the vulnerable period of synapse formation, while also identifying molecular signatures of SFN-mediated neuroprotection that could be relevant for combatting other environmental toxicants.

Cleavage site heterogeneity at the pre-mRNA 3'-untranslated region regulates gene expression in oxidative stress response

The endonucleolytic cleavage step of the eukaryotic mRNA 3'-end processing is considered imprecise, which leads to heterogeneity of cleavage site (CS) with hitherto unknown function. Contrary to popular belief, we show that this imprecision in the cleavage is tightly regulated, resulting in the CS heterogeneity (CSH) that controls gene expression in antioxidant response. CSH centres around a primary CS, followed by several subsidiary cleavages determined by CS's positions. Globally and using reporter antioxidant mRNA, we discovered an inverse relationship between the number of CS and the gene expression, with the primary CS exhibiting the highest cleavage efficiency. Strikingly, reducing CSH and increasing primary CS usage induces gene expression. Under oxidative stress (we employ three conditions that induce antioxidant response, tBHQ, H2O2, and NaAsO2) conditions, there is a decrease in the CSH and an increase in the primary CS usage to induce antioxidant gene expression. Key oxidative stress response genes (NQO1, HMOX1, PRDX1, and CAT) also show higher CSH compared to the non-stress response genes and that the number of CSs are reduced to impart cellular response to oxidative stresses. Concomitantly, ectopic expression of one of the key antioxidant response gene (NQO1) driven by the primary CS but not from other subsidiary CSs, or reduction in CSH imparts tolerance to cellular oxidative stresses (H2O2, and NaAsO2). Genome-wide CS analysis of stress response genes also shows a similar result. Compromised CSH or CSH-mediated gene control hampers cellular response to oxidative stress. We establish that oxidative stress induces affinity/strength of cleavage complex assembly, increasing the fidelity of cleavage at the primary CS, thereby reducing CSH inducing antioxidant response. Together, our study reports a novel cleavage imprecision- or CSH-mediated anti-oxidant response mechanism that is distinct and operates downstream but in concert with the transcriptional pathway of oxidative stress induction.

Natural polyphenols as novel interventions for aging and age-related diseases: Exploring efficacy, mechanisms of action and implications for future research

Natural polyphenols are a group of components widely found in traditional Chinese medicines and have been demonstrated to delay or prevent the development of aging and age-related diseases in recent years. As far as we know, the studies of natural polyphenols in aging and aging-related diseases have never been extensively reviewed. In the present paper, we reviewed recent advances of natural polyphenols in aging and common age-related diseases and the current technological methods to improve the bioavailability of natural polyphenols. The results showed that natural polyphenols have the potential to prevent or treat aging and common age-related diseases through multiple mechanisms. Nanotechnology, structural modifications, and matrix processing could provide strong technical support for the development of natural polyphenols to prevent or treat aging and age-related diseases. In conclusion, natural polyphenols have important potential in the prevention and treatment of aging and age-related diseases.

Capsiate attenuates atherosclerosis by activating Nrf2/GPX4 pathway and reshaping the intestinal microbiota in ApoE-/- mice

Atherosclerosis (AS) is the basis of cardiovascular diseases (CVDs) and remains the major contributor to death worldwide. Capsiate is derived from sweet pepper fruit and exhibits numerous pharmacological activities. The objective of this study was to elucidate the protective role of capsiate in atherosclerosis by examining its effect and the underlying regulatory pathways. Here, we showed that capsiate treatment alleviates atherosclerosis in atherosclerosis-prone apolipoprotein E-deficient (ApoE-/-) mice. We found that capsiate effectively reduced the plaque area and body weight compared to the Model group. Capsiate inhibited inflammatory response by downregulating phosphoinositide 3-kinase/protein kinase B/nuclear factor-κB pathway. Additionally, further investigation indicated that capsiate could regulate lipid levels in mice via reducing the expressions of 3-hydroxy-3-methylglutaryl coenzyme A reductase and low-density lipoprotein receptor, and increasing the expression of recombinant cytochrome P450 7A1. Furthermore, capsiate effectively activated transient receptor potential vanilloid subfamily member 1 in ApoE-/- mice fed a high-fat diet. The microbial sequencing demonstrated capsiate administration significantly regulated the gut microbiota disturbance and increased some beneficial bacterial (Lachnospiraceae NK4A136 group) levels in ApoE-/- mice. Human umbilical vein endothelial cells (HUVECs) were exposed to oxidized low-density lipoprotein (ox-LDL) to stimulate atherosclerotic endothelial damage in vitro. Our study revealed that capsiate inhibited ox-LDL-induced HUVECs injury and inflammation. We further investigated the effects of capsiate on ferroptosis in vivo and in vitro; it was found that capsiate exhibited anti-ferroptosis through regulating nuclear factor erythroid 2-related factor 2/glutathione peroxidase 4 pathway. Interestingly, ML385 reversed the anti-ferroptosis effect of capsiate in HUVECs. Taken together, our findings suggest a promising use of small-molecule drug capsiate for the treatment of AS and related CVDs.

IMPORTANCE

Capsiate has been found to inhibit fat accumulation, promote energy metabolism, and exhibit anti-inflammatory and antioxidative properties. However, there has still been no study on the ferroptosis and gut microbiota of capsiate in atherosclerosis (AS) mouse models. Our study is the first to report on the reshaping of the structure of the gut microbiota by capsiate in AS, and to explore the potential mechanism underlying the improvement of AS. In this study, we demonstrated that capsiate could effectively alleviate high-fat diet-induced AS in apolipoprotein E-deficient mice by inhibiting inflammatory response, improving serum lipid profiles, activating transient receptor potential vanilloid subfamily member 1 pathway, and suppressing ferroptosis. Moreover, the study reported the potential of gut microbiota as mediators of capsiate therapy for AS in animal models. Therefore, these findings may provide robust experimental support for the clinical use of capsiate for AS treatment.

Natural xanthones as modulators of the Nrf2/ARE signaling pathway and potential gastroprotective agents

Oxidative stress is implicated in the initiation, pathogenesis, and progression of various gastric inflammatory diseases (GID). The prevalence of these diseases remains a concern along with the increasing risks of adverse effects in current clinical interventions. Hence, new gastroprotective agents capable of inhibiting oxidative stress by modulating cellular defense systems such as the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway are critically needed to address these issues. A candidate to solve the present issue is xanthone, a natural compound that reportedly exerts gastroprotective effects via antioxidant, anti-inflammatory, and cytoprotective mechanisms. Moreover, xanthone derivatives were shown to modulate the Nrf2/ARE signaling pathway to counter oxidative stress in both in vitro and in vivo models. Thirteen natural xanthones have demonstrated the ability to modulate the Nrf2/ARE signaling pathway and have high potential as lead compounds for GID as indicated by their in vivo gastroprotective action-particularly mangiferin (2), α-mangostin (3), and γ-mangostin (4). Further studies on these compounds are recommended to validate the Nrf2 modulatory ability in relation to their gastroprotective action.

Combined Restraint Stress and Metal Exposure Paradigms in Rats: Unravelling Behavioural and Neurochemical Perturbations

Accumulation of heavy metals (Mn and Ni) and prolonged exposure to stress are associated with adverse health outcomes. Various studies have shown the impacts of stress and metal exposures on brain function. However, no study has examined the effects of co-exposure to stress, Mn, and Ni on the brain. This study addresses this gap by evaluating oxidative and glial responses, apoptotic activity, as well as cognitive processes in a rat model. Adult Wistar rats were exposed to vehicle (control), restraint stress, 25 mg/kg of manganese (Mn) or nickel (Ni), or combined restraint stress plus Mn or Ni. Following treatment, rats were subjected to several behavioural paradigms to assess cognitive function. Enzyme activity, as well as ATPase levels, were evaluated. Thereafter, an immunohistochemical procedure was utilised to evaluate neurochemical markers of glial function, myelination, oxidative stress, and apoptosis in the hippocampus, prefrontal cortex (PFC), and striatum. Results showed that stress and metal exposure increased oxidative stress markers and reduced antioxidant levels. Further, combined stress and metal exposure reduced various forms of learning and memory ability in rats. In addition, there were alterations in Iba1 activity and Nrf2 levels, reduced Olig2 and myelin basic protein (MBP) levels, and increased caspase-3 expression. These neurotoxic outcomes were mostly exacerbated by co-exposure to stress and metals. Overall, our findings establish that stress and metal exposures impaired cognitive performance, induced oxidative stress and apoptosis, and led to demyelination effects which were worsened by combined stress and metal exposure.

Considerations for antibody-based detection of NRF2 in human cells

Based on the knockdown and overexpression experiments, it is accepted that in Tris-glycine SDS-PAGE human NRF2 migrates above 100 kDa, depending on the percentage of the gel. In 8 % Tris-glycine gel, monoclonal anti-NRF2 antibodies detect NRF2 signal as three bands migrating between 100 and 130 kDa. Here we used mass spectrometry to identify proteins immunoprecipitated by anti-NRF2 antibodies migrating in this range under steady state, upon NRF2 activator tert-BHQ and after translation inhibition with emetine. Our results show that three commercial monoclonal antibodies with epitopes in the center and in the C-terminus of NRF2 also bind calmegin, an ER-residing chaperone, that co-migrates with NRF2 in SDS-PAGE and gives stronger signal in western blot than NRF2. Calmegin has a much longer half life than NRF2 and resides in the cytoplasm, which differentiates it from NRF2. The most specific anti-NRF2 antibody in western blot, Cell Signaling Technology clone E5F1 is also specific in staining nuclear NRF2 in immunofluorescence. Other antibodies, that recognize calmegin in western blot, still can be specific for nuclear NRF2 in immunofluorescence, but require prior validation with NRF2 knockdown or knockout. These results appeal for caution and consideration when analyzing and interpreting results from antibody-based NRF2 detection.

Polybrominated biphenyls induce liver injury by disrupting the KEAP1/Nrf2/SLC7A11 axis leading to impaired GSH synthesis and ferroptosis in hepatocytes

Polybrominated biphenyls (PBBs) are persistent organic pollutants (POPs) widespread in the environment, presenting significant health hazards due to their bioaccumulation, particularly in liver. Ferroptosis, an iron-dependent form of cell death, has not been previously linked to PBBs-induced hepatotoxicity. This study investigated whether PBBs induce hepatotoxicity through ferroptosis and the toxicological mechanism using mice and THLE-2 cells models exposed to PBB mixture (BP-6). Histopathological and biochemical analyses revealed that BP-6 exposure-induced hepatic injury, oxidative stress, and inflammatory response in mice. BP-6 exposure induced a significant increase in Fe2+ content and a decrease in FTH1, SLC7A11 and GPX4 protein expression in hepatocytes, resulting in severe lipid peroxide accumulation and GSH depletion. Ferroptosis inhibitors, Fer-1 and DFO, reversed the iron metabolism disruption caused by BP-6, underscoring the critical role of ferroptosis in BP-6-induced liver injury. Mechanistically, BP-6 exposure impaired GSH synthesis by preventing Nrf2 nuclear translocation and Slc7a11 transcription through upregulating KEAP1 levels. Keap1 knockdown or Slc7a11 overexpression reversed BP-6-induced lipid peroxide accumulation and GSH depletion, confirming the involvement of ferroptosis in BP-6-induced hepatotoxicity. In addition, curcumin, a natural Nrf2 agonist, significantly alleviated BP-6-induced ferroptosis and liver injury in vitro and in vivo by restoring SLC7A11 protein expression and GSH synthesis. These findings elucidate the toxicological mechanism of PBBs and suggest potential therapeutic strategies to counteract PBBs exposure.

Aluminum exposure alters oocytes spindle, and tadpole behavior with modifications of proteasome and oxidative stress markers in Xenopus laevis

Aluminum, a non-essential metal, identified as potentially toxic to organisms, is increasingly released and accumulated into the aquatic ecosystems as a result of human activities. However, only a few data are available regarding its action in aquatic vertebrates during their early stages of development. In order to further investigate the toxicity mechanisms induced by this metal, we used a relevant model in ecotoxicology Xenopus laevis. Oocytes and embryos were exposed to aluminum sulfate (Al2(SO4)3), at various concentrations, ranging from environmentally relevant levels to those known to cause toxicity. The results indicate that during oocyte maturation, abnormalities in meiotic spindles were observed at concentrations ranging from 0.05 to 50 mg/L. At these exposure concentrations, the fertilization efficiency, phenotypes and cardiac rhythms of tadpoles were not affected. On the contrary, at 50 mg/L, the behavior of 6 days tadpoles was modified towards a longer hypoactivity. Concomitantly, Western blot analysis showed that heat shock Hsp70 and proteasome Rpn10 were increased, while, oxidative stress markers Sod1, Gst, and Nrf2 were decreased. Our work identifies aluminum as a threat to oocyte maturation and tadpole behavior in Xenopus laevis potentially impacting their population dynamics. Moreover, Nrf2 and Rpn10 are uncovered as potential toxicity markers for this early tadpole period and could serve to evaluate aluminum exposure in aquatic species.

Total alkaloids from Thesium chinense inhibit lipopolysaccharide-induced respiratory inflammation by modulating Nrf2/NF-κB/NLRP3 signaling pathway

Inflammation plays a pivotal role in the etiology and progression of various diseases. In traditional Chinese medicine, the whole plants of Thesium chinense Turcz. and its preparations (e.g. Bairui Granules) have been employed to manage inflammatory conditions. While flavonoids were previously considered the primary anti-inflammatory components, other potentially active constituents have been largely overlooked and not thoroughly investigated. This study presents a novel finding that the total alkaloids of T. chinense (BC-Alk) are potent active substances underlying the traditional and clinical applications of T. chinense and Bairui Granules as anti-inflammatory agents. UPLC-MS/MS analysis identified the composition of BC-Alk as quinolizidine alkaloids. The anti-inflammatory efficacy of BC-Alk was evaluated using a lipopolysaccharide (LPS)-induced lung inflammation model in mice. Results demonstrated that BC-Alk significantly mitigated LPS-induced lung inflammation, attenuated the overproduction of IL-1β and the overproduction of inflammatory factors (TNF-α), and ameliorated lung tissue hyperplasia in mice in vivo. Mechanistic studies in vitro revealed that BC-Alk upregulated the expression of Nrf2 and its downstream proteins NQO1 and glutamate-cystine ligase and modifier subunit (GCLM), inhibited NF-κB phosphorylation, and suppressed NLRP3 activation. Collectively, these findings indicate that BC-Alk exerts potent inhibitory effects against lung inflammation by modulating Nrf2, NF-κB, and NLRP3 pathways. This study provides new insights into the anti-inflammatory constituents of T. chinense and Bairui Granules.

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.

Astaxanthin protects against environmentally persistent free radical-induced oxidative stress in well-differentiated respiratory epithelium

Environmentally persistent free radicals (EPFRs) are combustion products present in substantial numbers on atmospheric particulate matter with half-lives of days to years. The mechanisms linking EPFR exposure and respiratory diseases are unclear, but likely involve oxidative stress. We investigated the mechanisms by which EPFR exposure impact on well-differentiated primary human nasal epithelial cells from subjects sensitive or resistant to oxidant stressors, cultured at an air-liquid interface. We found that EPFR exposure induced mitochondrial reactive oxygen species (mtROS) production; increased mitochondrial DNA copy number; down-regulated mucus production gene, Mucin-5AC (MUC5AC); up-regulated detoxifying gene, cytochrome P450 1A1 (CYP1A1), nuclear factor erythroid 2-related factor 2 (NRF2)-regulated antioxidant pathways including Sirtuin 1 (SIRT1)-Forkhead box O3 (FOXO3), mitophagy, PTEN-induced kinase 1 (PINK1), apoptosis, cyclin-dependent kinase inhibitor p21 (p21), and inflammation, C-C motif chemokine ligand 5 (CCL5). These results indicate that the well-differentiated respiratory epithelium can respond and activate redox reactions when exposed to sublethal concentrations of EPFRs. Increased susceptibility to EPFR exposure is conferred by failure to upregulate the mucin gene, MUC5AC, expression. Pre-treatment with astaxanthin prevented most of the negative impacts caused by EPFRs. Our results demonstrate that EPFRs can induce oxidative stress and cause damage to respiratory epithelium. A dietary antioxidant, astaxanthin, protected cells from EPFR-induced oxidant stress.

FGF21 Alleviates Hypoxic-Ischemic White Matter Injury in Neonatal Mice by Mediating Inflammation and Oxidative Stress Through PPAR-γ Signaling Pathway

White matter injury (WMI), the most common type of brain damage in infants born preterm, is characterized by failure in oligodendrocyte progenitor cell maturation and myelination, thereby contributing to long-term neurological impairments. Regrettably, effective therapies for promoting remyelination and improving function are currently lacking for this growing population affected by WMI. Recombinant human fibroblast growth factor (rhFGF) 21 modulated microglial activation and then ameliorated brain damage and improved neurological deficits in several central nervous system diseases. However, the effects of rhFGF21 treatment on WMI in preterm infants remain uncertain. In this study, we established an in vivo mouse model of cerebral hypoxia-ischemia (HI)-induced brain WMI and an in vitro model using oxygen-glucose deprivation (OGD)-treated HMC3 cells to investigate the neuroprotective effects of rhFGF21 against WMI and elucidated the potential mechanism. Our findings demonstrated that administration of rhFGF21 significantly ameliorated the retardation of oligodendrocyte differentiation, promoted myelination, and mitigated axonal deficits, synaptic loss, and GFAP scarring, thereby improving lifelong cognitive and neurobehavioral dysfunction associated with WMI. Moreover, rhFGF21 modulated microglial polarization, promoted a shift from the M1 to the M2 microglial phenotype, and suppressed microglial activation, thus ameliorating inflammatory response and oxidative stress. Additionally, rhFGF21 treatment significantly inhibited the HMGB1/NF-κB pathway linked to inflammation, and activated the NRF2 pathway associated with oxidative stress through the upregulation of PPAR-γ. Importantly, the beneficial effects of rhFGF21 on HI-induced WMI and microglial activation were dramatically inhibited by PPAR-γ antagonist and its siRNA. Our findings provide compelling evidence that rhFGF21 treatment mitigated the inflammatory response and oxidative stress through the modulation of microglial polarization via the PPAR-γ-mediated HMGB1/NF-κB pathway and the NRF2 pathway, respectively, contributes to neuroprotection and the amelioration of WMI in neonatal mice. Thus, rhFGF21 represents a promising therapeutic agent for the treatment of neonatal WMI.

BRD4 Mediates Cadmium-Induced Oxidative Stress and Kidney Injury in Mice via Disruption of Redox Homeostasis

Cadmium (Cd) is a toxic heavy metal that threatens public health, with kidney injury being one of the common manifestations after Cd exposure. Oxidative stress plays a crucial role in Cd-induced kidney injury, arising from an imbalance between cellular oxidation and antioxidation processes. Bromodomain-containing protein 4 (BRD4) has been identified as a significant factor in the initiation and advancement of multiple diseases, primarily due to its regulatory role in oxidative stress. Nevertheless, the specific role of BRD4 in Cd-induced kidney oxidative injury remains poorly understood. The present study demonstrates that BRD4 is activated in the kidney after Cd exposure, while JQ1 (a BRD4 inhibitor) treatment inhibits Cd-induced oxidative stress and kidney injury. Subsequently, we investigate the mechanisms by which Cd regulates oxidative stress both in vivo and in vitro. The results indicate that JQ1 treatment reduces the expression levels of NADPH oxidase 4 (Nox4), thereby alleviating mitochondrial damage and reducing reactive oxygen species (ROS) generation. Furthermore, JQ1 treatment facilitates nuclear translocation levels of Nuclear factor erythroid-derived 2-like 2 (Nrf2), thereby enhancing the antioxidant defense system in the kidney after Cd exposure. In conclusion, this study reveals that BRD4 is significantly involved in the process of Cd-induced oxidative damage in the kidney, while inhibiting BRD4 is observed to attenuate ROS generation by regulating Nox4 and enhance ROS scavenging by regulating Nrf2, which, in turn, suppresses the oxidative stress level in the kidney after Cd exposure. These findings suggest that targeting BRD4 may represent an effective strategy for the prevention and treatment of Cd-induced kidney diseases.

Transcription factor addictions: exploring the potential Achilles' Heel of endometriosis

A considerable number of women of reproductive age suffer from endometriosis worldwide. There is a significant physical, mental, and financial burden on patients affected by this condition in terms of pelvic pain, either continuously or intermittently, dysmenorrhea, infertility, and a higher risk of certain types of cancer. Several treatments available in clinical settings for endometriosis management do not provide adequate efficacy and have undesirable side effects. Transcription factors (TFs) are crucial regulators of key biological processes involved in endometriosis. Here, we elaborated on the research progress regarding the crucial roles of TFs in endometriosis, emphasizing their implications for clinical outcomes and critical therapeutic contributions. By delving into their involvement in key processes, such as cell proliferation and apoptosis, we revealed the multifaceted role of key TFs in disease progression. We aimed to provide a systemic understanding of TFs regulation in endometriosis pathogenesis, establishing a foundation for innovative treatment approaches.

Cell-Free DNA (cfDNA) Regulates Metabolic Remodeling, Sustaining Proliferation, Quiescence, and Migration in MDA-MB-231, a Triple-Negative Breast Carcinoma (TNBC) Cell Line

Background: The clinical relevance of circulating cell-free DNA (cfDNA) in oncology has gained significant attention, with its potential as a biomarker for cancer diagnosis and monitoring. However, its precise role in cancer biology and progression remains unclear. cfDNA in cancer patients' blood has been shown to activate signaling pathways, such as those mediated by toll-like receptors (TLRs), suggesting its involvement in cancer cell adaptation to the tumor microenvironment. Methods: This impact of cfDNA released from MDA-MB-231, a triple-negative breast cancer (TNBC) cell line was assessed, focusing on glucose availability and culture duration. The impact of cfDNA on the proliferation of MDA-MB-231 cells was investigated using proliferation curves, while cellular migration was evaluated through wound healing assays. The metabolic alterations induced by distinct cfDNA variants in MDA-MB-231 cells were investigated through nuclear magnetic resonance (NMR) spectroscopy, and their effect on cisplatin resistance was evaluated using flow cytometry. Furthermore, the expression levels of DNA-sensitive Toll-like receptor 9 (TLR9) were quantified via immunofluorescence, alongside its colocalization with lysosome-associated membrane protein 1 (LAMP1). Results: This study indicates that cfDNA facilitates metabolic adaptation, particularly under metabolic stress, by modulating glucose and glutamine consumption, key pathways in tumor cell metabolism. Exposure to cfDNA induced distinct metabolic shifts, favoring energy production through oxidative phosphorylation. The anti-cancer activity of cfDNA isolated from conditioned media of cells cultured under stressful conditions is influenced by the culture duration, emphasizing the importance of adaptation and se-lection in releasing cfDNA that can drive pro-tumoral processes. Additionally, cfDNA exposure influenced cell proliferation, quiescence, and migration, processes linked to metastasis and treatment resistance. These findings underscore cfDNA as a key mediator of metabolic reprogramming and adaptive responses in cancer cells, contributing to tumor progression and therapy resistance. Furthermore, the activation of TLR9 signaling suggests a mechanistic basis for cfDNA-induced phenotypic changes. Conclusions: Overall, cfDNA serves as a crucial signaling molecule in the tumor microenvironment, orchestrating adaptive processes that enhance cancer cell survival and progression.

Pharmacological inhibition of STING-mediated GPX4 autophagic degradation by 4-octyl itaconate ameliorates sepsis-induced acute kidney injury

The precise pathogenic mechanisms underlying sepsis-induced acute kidney injury (AKI) remain elusive. Emerging evidence suggests a link between tubular ferroptosis and the pathogenesis of AKI, though the regulatory pathways are not fully understood. Stimulator of interferon genes (STING), previously recognized as a pivotal mediator of innate immunity via DNA-sensing pathways, is increasingly associated with lipid peroxidation, a hallmark of ferroptosis, and 4-octyl itaconate (4-OI) has been shown to inhibit STING activation, exerting anti-inflammatory effects. This study investigates the protective mechanisms of 4-OI in sepsis-AKI. Following cecal ligation and puncture (CLP), inflammation, oxidative stress, and ferroptosis levels in kidney tissue increased. Both 4-OI and ferrostatin-1 (Fer-1) mitigated renal ferroptosis, exerting anti-inflammatory and antioxidant stress effects, and improved renal function. Consistently, in vitro experiments demonstrated that 4-OI reduced ferroptosis in human renal proximal tubule (HK-2) cells induced by lipopolysaccharide (LPS). Mechanistically, 4-OI suppressed LPS-induced activation of the STING pathway and reduced levels of inflammatory cytokines in a manner independent of NF-E2-related factor 2 (Nrf2). Additionally, 4-OI inhibited STING transcription through the activation of Nrf2. These dual actions effectively suppressed LPS-induced STING pathway activation, thereby inhibiting STING-mediated autophagic degradation of glutathione peroxidase 4 (GPX4), reducing reactive oxygen species (ROS) accumulation, and alleviating ferroptosis. In summary, 4-OI is a promising therapeutic candidate, functioning both as a STING inhibitor and a ferroptosis inhibitor, with potential applications in the treatment of sepsis.

Overview of Nrf2 as a target in ovary and ovarian dysfunctions focusing on its antioxidant properties

Female infertility is a common issue caused by various factors, such as hormonal imbalances, age-related decline in oocyte quality, and lifestyle choices. Ovarian dysfunction is a prevalent cause, impacting fertility by damaging cells and impairing functions. Oxidative stress (OS) is a condition resulting from an imbalance between natural antioxidants and the generation of oxidants. This phenomenon acts as a double-edged sword, playing a crucial role as a signaling mechanism in both physiological and pathological processes related to the female reproductive system. OS is linked to ovarian dysfunction, leading to cell damage and reduced fertility. Nrf2 is a key regulator in oxidative homeostasis, helping to defend against OS and improve ovarian function in women of reproductive age. Therefore, this review aims to highlight the role of Nrf2 in the female reproductive system, focusing on its antioxidant properties.