The Keap1-Nrf2-ARE Pathway As a Potential Preventive and Therapeutic Target: An Update

Cell polarization in ischemic stroke: molecular mechanisms and advances

Ischemic stroke is a cerebrovascular disease associated with high mortality and disability rates. Since the inflammation and immune response play a central role in driving ischemic damage, it becomes essential to modulate excessive inflammatory reactions to promote cell survival and facilitate tissue repair around the injury site. Various cell types are involved in the inflammatory response, including microglia, astrocytes, and neutrophils, each exhibiting distinct phenotypic profiles upon stimulation. They display either proinflammatory or anti-inflammatory states, a phenomenon known as 'cell polarization.' There are two cell polarization therapy strategies. The first involves inducing cells into a neuroprotective phenotype in vitro, then reintroducing them autologously. The second approach utilizes small molecular substances to directly affect cells in vivo. In this review, we elucidate the polarization dynamics of the three reactive cell populations (microglia, astrocytes, and neutrophils) in the context of ischemic stroke, and provide a comprehensive summary of the molecular mechanisms involved in their phenotypic switching. By unraveling the complexity of cell polarization, we hope to offer insights for future research on neuroinflammation and novel therapeutic strategies for ischemic stroke.

Hesperidin activates Nrf2 to protect cochlear hair cells from cisplatin-induced damage

Cisplatin is widely employed in clinical oncology as an anticancer chemotherapy drug in clinical practice and is known for its severe ototoxic side effects. Prior research indicates that the accumulation of reactive oxygen species (ROS) plays a pivotal role in cisplatin's inner ear toxicity. Hesperidin is a flavanone glycoside extracted from citrus fruits that has anti-inflammatory and antioxidant effects. Nonetheless, the specific pharmacological actions of hesperidin in alleviating cisplatin-induced ototoxicity remain elusive. The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) is a critical mediator of the cellular oxidative stress response, is influenced by hesperidin. Activation of Nrf2 was shown to have a protective effect against cisplatin-induced ototoxicity. The potential of hesperidin to stimulate Nrf2 in attenuating cisplatin's adverse effects on the inner ear warrants further investigation. This study employs both in vivo and in vitro models of cisplatin ototoxicity to explore this possibility. Our results reveal that hesperidin mitigates cisplatin-induced ototoxicity by activating the Nrf2/NQO1 pathway in sensory hair cells, thereby reducing ROS accumulation, preventing hair cell apoptosis, and alleviating hearing loss.

Qifu-yin activates the Keap1/Nrf2/ARE signaling and ameliorates synaptic injury and oxidative stress in APP/PS1 mice

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional medicinal formulation, Qifu-yin (QFY), has been widely prescribed for Alzheimer's disease (AD) treatment in China, yet the comprehensive mechanisms through which QFY mitigates AD pathology remain to be fully delineated.

AIM OF THE STUDY

This study aimed to explore the therapeutic implications of QFY on the synaptic injury and oxidative stress in the hippocampus of APPswe/PS1dE9 (APP/PS1) mice, with a concerted effort to elucidate the molecular mechanisms related to synaptic preservation and memory improvement.

MATERIALS AND METHODS

The components of QFY were identified by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The neuroprotective effects of QFY was evaluated using six-month-old male APP/PS1 mice. Subsequent to a 15 days of QFY regimen, spatial memory was assessed utilizing the Morris water maze (MWM) test. Amyloid-beta (Aβ) aggregation was detected via immunostaining, while the quantification of Aβ1-40 and Aβ1-42 was achieved through enzyme-linked immunosorbent assay (ELISA). Transmission electron microscopy (TEM) was used to investigate the synaptic structure and mitochondrial morphology. Golgi staining was applied to examine dendritic spine density. Reactive oxygen species (ROS), 3-nitrotyrosine (3-NT) and 4-hydroxy-nonenal (4-HNE) assays were employed to assess oxidative stress. The expression profiles of Aβ metabolism-associated enzymes and the Keap1/Nrf2/ARE signaling pathway were determined by Western blot.

RESULTS

A total of 20 principal compounds in QFY were identified. QFY mitigated memory deficits of APP/PS1 mice, including reducing escape latency and search distance and increasing the time and distance spent in the target quadrant. In addition, QFY increased platform crossings of APP/PS1 mice in the probe trial of MWM tests. TEM analysis showed that QFY increased synapse number in the CA1 region of APP/PS1 mice. Further studies indicated that QFY elevated the expression levels of Post synaptic density protein 95 (PSD95) and synaptophysin, and mitigated the loss of dendritic spine density in the hippocampus of APP/PS1 mice. QFY has been shown to ameliorated the structural abnormalities of mitochondria, including mitochondrial dissolution and degradation, up-regulate ATP synthesis and membrane potential in the hippocampus of APP/PS1 mice. Moreover, QFY activated the Keap1/Nrf2/ARE signaling pathway in the hippocampus of APP/PS1 mice, which might contribute to the neuroprotective effects of QFY.

CONCLUSION

QFY activates the Keap1/Nrf2/ARE signaling, and protects against synaptic and mitochondrial dysfunction in APP/PS1 mice, proposing a potential alternative therapeutic strategy for AD management.

Resveratrol targeting NRF2 disrupts the binding between KEAP1 and NRF2-DLG motif to ameliorate oxidative stress damage in mice pulmonary infection

ETHNOPHARMACOLOGICAL RELEVANCE

The root of Polygonum cuspidatum Sieb. et Zucc (PC), known as 'Huzhang' in the Chinese Pharmacopoeia, has been traditionally employed for its anti-inflammatory, antiviral, antimicrobial, and other biological activities. Polydatin (PD) and its aglycone, resveratrol (RES), are key pharmacologically active components responsible for exerting anti-inflammatory and antioxidant effects. However, its specific targets and action mechanisms remain unclear.

AIM OF THE STUDY

The equilibrium of the KEAP1-NRF2 system serves as the primary protective response to oxidative and electrophilic stresses within the body, particularly in cases of acute lung injury caused by pathogenic microbial infection. In this study, the precise mechanisms by which RES alleviates oxidative stress damage in conjunction with NRF2 activators are discussed.

MATERIALS AND METHODS

The active components from PC were screened to evaluate their potential to inhibit reactive oxygen species (ROS) and activate antioxidant activity dependent on antioxidant response elements (ARE). RES was evaluated for its potential to alleviate the oxidative stress caused by pathogenic microbial infection. Functional probes were designed to study the RES distribution and identify its targets. A lipopolysaccharide (LPS)-induced oxidative injury model was used to evaluate the effects of RES on the KEAP1-NRF2/ARE pathway in RAW 264.7 cells. The interaction between RES and NRF2 was elucidated using drug-affinity responsive target stability (DARTS), cellular thermal shift assays (CETSA), co-immunoprecipitation (Co-IP), and microscale thermophoresis (MST) techniques. The key binding sites were predicted using molecular docking and validated in NRF2-knockdownand reconstructed cells. Finally, protective effects against pulmonary stress were verified in a mouse model of pathogenic infection.

RESULTS

The accumulation of RES in lung macrophages disrupted the binding between KEAP1 and NRF2, thereby preventing the ubiquitination degradation of NRF2 through its interaction with Ile28 on the NRF2-DLG motif. The activation of NRF2 resulted in the upregulation of nuclear transcription, enhances the expression of antioxidant genes dependent on ARE, suppresses ROS generation, and ameliorates oxidative damage both in vivo and in vitro.

CONCLUSION

These findings shed light on the potential of RES to mitigate oxidative stress damage caused by pathogenic microorganism-induced lung infections and facilitate the discovery of novel small molecule modulators targeting the KEAP1-NRF2 DLG motif interaction.

Rosolic acid as a novel activator of the Nrf2/ARE pathway in arsenic-induced male reproductive toxicity: An in silico study

Male reproductive toxicity as a result of arsenic exposure is linked with oxidative stress and excessive generation of reactive oxygen species (ROS). It leads to an imbalance between ROS production and antioxidant defense mechanisms ultimately resulting in male infertility. The nuclear factor erythroid 2 (NFE2)-related factor 2 (Nrf2) is a transcription factor that responds to cellular stressors controlling the oxidative state, mitochondrial dysfunction, inflammation, and proteostasis. This study aims to investigate the potential of Rosolic acid (ROA) to act as a novel Nrf2 activator by mitigating oxidative stress to combat arsenic-induced male reproductive toxicity. The protein and ligands were prepared in the BIOVIA Discovery Studio, followed by protein-ligand docking using auto dock vina integrated with the PyRx-Virtual Screening Tool. Then the ADME properties were analyzed using the SwissADME tool to get a clear idea about the physicochemical properties, lipophilicity, water solubility, pharmacokinetics, and drug likeliness of ROA. It was followed by molecular dynamics simulation (MDS) studies using GROMACS. The 3D and 2D interaction maps revealed the interactions of Keap 1 with ROA. Keap1-ROA complex was found to have a binding energy of -7.8 kcal/mol. ROA showed 0 violations for Lipinski and 0 alerts each for PAINS and Brenk and a bioavailability score of 0.55. The BOILED-Egg representation showcases that ROA is predicted as passively crossing the blood-brain barrier (BBB). The MDS described 2FLU-ROA as a stable system. This work portrays that ROA can be a potent Nrf2 activator by exhibiting an inhibitory activity against the Keap1 protein and thus mitigating oxidative stress in arsenic-induced male reproductive toxicity.

Active fraction of Polyrhachis vicina (Rogers) inhibits osteoclastogenesis by targeting Trim38 mediated proteasomal degradation of TRAF6

BACKGROUND

Reactive Oxygen Species (ROS) is a key factor in the pathogenesis of osteoporosis (OP) primarily characterized by excessive osteoclast activity. Active fraction of Polyrhachis vicina Rogers (AFPR) exerts antioxidant effects and possesses extensive promising therapeutic effects in various conditions, however, its function in osteoclastogenesis and OP is unknown.

PURPOSE

The aim of this study is to elucidate the cellular and molecular mechanisms of AFPR in OP.

STUDY DESIGN AND METHODS

CCK8 assay was used to evaluate the cell viability under AFPR treatment. TRAcP staining, podosome belts staining and bone resorption were used to test the effect of AFPR on osteoclastogenesis. Immunofluorescence staining was used to observe the effect of AFPR on ROS production. si-RNA transfection, coimmunoprecipitation and Western-blot were used to clarify the underlying mechanisms. Further, an ovariectomy (OVX) -induced OP mice model was used to identify the effect of AFPR on bone loss using Micro-CT scanning and histological examination.

RESULTS

In the present study, AFPR inhibited osteoclast differentiation and bone resorption induced by nuclear factor-κB receptor activator (NF-κB) ligand (RANKL) in dose-/ time-dependent with no cytotoxicity. Meanwhile, AFPR decreased RANKL-mediated ROS levels and enhanced ROS scavenging enzymes. Mechanistically, AFPR promoted proteasomal degradation of TRAF6 by significantly upregulating its K48-linked ubiquitination, subsequently inhibiting NFATc1 activity. We further observed that tripartite motif protein 38 (TRIM38) could mediate the ubiquitination of TRAF6 in response to RANKL. Moreover, TRIM38 could negatively regulate the RANKL pathway by binding to TRAF6 and promoting K48-linked polyubiquitination. In addition, TRIM38 deficiency rescued the inhibition of AFPR on ROS and NFATc1 activity and osteoclastogenesis. In line with these results, AFPR reduced OP caused by OVX through ameliorating osteoclastogenesis.

CONCLUSION

AFPR alleviates ovariectomized-induced bone loss via suppressing ROS and NFATc1 by targeting Trim38 mediated proteasomal degradation of TRAF6. The research offers innovative perspectives on AFPR's suppressive impact in vivo OVX mouse model and in vitro, and clarifies the fundamental mechanism.

Paternal exercise induces antioxidant defenses by α-Klotho/Keap1 pathways in the skeletal muscle of offspring exposed to a high fat-diet without changing telomere length

Although previous studies demonstrated that the ancestral lifestyle can enhance the metabolic health of offspring exposed to an obesogenic diet, the specific connections between these positive effects in redox state and telomere length are unknown. We investigated the impact of paternal resistance training (RT) on stress-responsive signaling and the pathways involved in telomere homeostasis in skeletal muscle. This investigation encompassed both the fathers and first-generation litter exposed to a long-term standard diet (24 weeks) and high fat diet (HFD). Wistar rats were randomized into sedentary or trained fathers (8 weeks of resistance training). The offspring were obtained by mating with sedentary females. Upon weaning, male offspring were divided into four groups: offspring of sedentary or trained fathers exposed to either a control diet or HFD. The gastrocnemius was prepared for reverse transcription-quantitative polymerase chain reaction, immunoblotting, ELISA, and electron paramagnetic resonance spectroscopy. RT upregulated shelterin mRNA levels and antioxidant protein, preserving muscle telomere in fathers. Conversely, HFD induced a disturbance in the redox balance, which may have contributed to the offspring telomere shortening from sedentary fathers. Pre-conceptional paternal RT downregulates Kelch-like ECH-associated protein 1 (Keap1) mRNA levels in the skeletal muscle of progeny exposed to HFD, driving an increase in Glutathione reductase mRNA levels, Sod1 and Catalase protein levels to mitigate ROS production. Also, paternal exercise upregulates α-Klotho protein levels, mediating antioxidative responses without altering shelterin mRNA levels and telomere length. We provide the first in-depth analysis that the offspring's redox state seems to be directly associated with the beneficial effects of paternal exercise.

Z-ligustilide provides a neuroprotective effect by regulating the phenotypic polarization of microglia via activating Nrf2-TrxR axis in the Parkinson's disease mouse model

The polarization phenotype of microglia is critical in the progression of Parkinson's disease (PD). Molecules that can polarize microglia toward the M2 phenotype represent a promising class of compounds for anti-PD medications. Z-ligustilide (ZLG) is a naturally occurring enol ester with diverse pharmacological properties, especially in neuroprotection. For the first time, we investigated the effect of ZLG on anti-PD and elucidated its underlying mechanism. The results primarily showed that ZLG attenuated motor deficits in mice and prevented the loss of dopaminergic neurons in the substantia nigra. Mechanistically, ZLG alleviates oxidative stress-induced apoptosis of microglia by triggering the endogenous antioxidant system. Besides, ZLG modulated phenotypic polarization of the microglia through the activation of the Nrf2-TrxR axis, leading to microglia polarization towards the M2 phenotype. Taken together, our research showed that ZLG is a prospective therapy candidate for PD by altering microglia polarization and restoring redox equilibrium through the Nrf2-TrxR axis.

Research progress on the role and inhibitors of Keap1 signaling pathway in inflammation

Inflammation is a protective mechanism against endogenous and exogenous pathogens. It is a typical feature of numerous chronic diseases and their complications. Keap1 is an essential target in oxidative stress and inflammatory diseases. Among them, the Keap1-Nrf2-ARE pathway (including Keap1-Nrf2-HO-1) is the most significant pathway of Keap1 targets, which participates in the control of inflammation in multiple organs (including renal inflammation, lung inflammation, liver inflammation, neuroinflammation, etc.). Identifying new Keap1 inhibitors is crucial for new drug discovery. However, most drugs have specificity issues as they covalently bind to cysteine residues of Keap1, causing off-target effects. Therefore, direct inhibition of Keap1-Nrf2 PPIs is a new research idea. Through non-electrophilic and non-covalent binding, its inhibitors have better specificity and ability to activate Nrf2, and targeting therapy against Keap1-Nrf2 PPIs has become a new method for drug development in chronic diseases. This review summarizes the members and downstream genes of the Keap1-related pathway and their roles in inflammatory disease models. In addition, we summarize all the research progress of anti-inflammatory drugs targeting Keap1 from 2010 to 2024, mainly describing their biological functions, molecular mechanisms of action, and therapeutic roles in inflammatory diseases.

Artesunate induces HO-1-mediated cell cycle arrest and senescence to protect against ocular fibrosis

Recent research found artesunate could inhibit ocular fibrosis; however, the underlying mechanisms are not fully known. Since the ocular fibroblast is the main effector cell in fibrosis, we hypothesized that artesunate may exert its protective effects by inhibiting the fibroblasts proliferation. TGF-β1-induced ocular fibroblasts and glaucoma filtration surgery (GFS)-treated rabbits were used as ocular fibrotic models. Firstly, we analyzed fibrosis levels by assessing the expression of fibrotic marker proteins, and used Ki67 immunofluorescence, EdU staining, flow cytometry to determine cell cycle status, and SA-β-gal staining to assess cellular senescence levels. Then to predict target genes and pathways of artesunate, we analyzed the differentially expressed genes and enriched pathways through RNA-seq. Western blot and immunohistochemistry were used to detect the pathway-related proteins. Additionally, we validated the dependence of artesunate's effects on HO-1 expression through HO-1 siRNA. Moreover, DCFDA and MitoSOX fluorescence staining were used to examine ROS level. We found artesunate significantly inhibits the expression of fibrosis-related proteins, induces cell cycle arrest and cellular senescence. Knocking down HO-1 in fibroblasts with siRNA reverses these regulatory effects of artesunate. Mechanistic studies show that artesunate significantly inhibits the activation of the Cyclin D1/CDK4-pRB pathway, induces an increase in cellular and mitochondrial ROS levels and activates the Nrf2/HO-1 pathway. In conclusion, the present study identifies that artesunate induces HO-1 expression through ROS to activate the antioxidant Nrf2/HO-1 pathway, subsequently inhibits the cell cycle regulation pathway Cyclin D1/CDK4-pRB in an HO-1-dependent way, induces cell cycle arrest and senescence, and thereby resists periorbital fibrosis.

Nrf2 mediated signaling axis in heart failure: Potential pharmacological receptor

Heart failure (HF) has emerged as the most pressing health concerns globally, and extant clinical therapies are accompanied by side effects and patients have a high burden of financial. The protein products of nuclear factor erythroid 2-related factor 2 (Nrf2) target genes have a variety of cardioprotective effects, including antioxidant, metabolic functions and anti-inflammatory. By evaluating established preclinical and clinical research in HF to date, we explored the potential of Nrf2 to exert unique cardioprotective functions as a novel therapeutic receptor for HF. In this review, we generalize the progression, structure, and function of Nrf2 research in the cardiovascular system. The mechanism of action of Nrf2 involved in HF as well as agonists of Nrf2 in natural compounds are summarized. Additionally, we discuss the challenges and implications for future clinical translation and application of pharmacology targeting Nrf2. It's critical to developing new drugs for HF.

Natural products act as game-changer potentially in treatment and management of sepsis-mediated inflammation: A clinical perspective

BACKGROUND

Sepsis, a life-threatening condition resulting from uncontrolled host responses to infection, poses a global health challenge with limited therapeutic options. Due to high heterogeneity, sepsis lacks specific therapeutic drugs. Additionally, there remains a significant gap in the clinical management of sepsis regarding personalized and precise medicine.

PURPOSE

This review critically examines the scientific landscape surrounding natural products in sepsis and sepsis-mediated inflammation, highlighting their clinical potential.

METHODS

Following the PRISMA guidelines, we retrieved articles from PubMed to explore potential natural products with therapeutic effects in sepsis-mediated inflammation.

RESULTS

434 relevant in vitro and in vivo studies were identified and screened. Ultimately, 55 studies were obtained as the supporting resources for the present review. We divided the 55 natural products into three categories: those influencing the synthesis of inflammatory factors, those affecting surface receptors and modulatory factors, and those influencing signaling pathways and the inflammatory cascade.

CONCLUSION

Natural products' potential as game-changers in sepsis-mediated inflammation management lies in their ability to modulate hallmarks in sepsis, including inflammation, immunity, and coagulopathy, which provides new therapeutic avenues that are readily accessible and capable of undergoing rapid clinical validation and deployment, offering a gift from nature to humanity. Innovative techniques like bioinformatics, metabolomics, and systems biology offer promising solutions to overcome these obstacles and facilitate the development of natural product-based therapeutics, holding promise for personalized and precise sepsis management and improving patient outcomes. However, standardization, bioavailability, and safety challenges arise during experimental validation and clinical trials of natural products.

Kidney Injury in a Murine Hemorrhagic Shock/Resuscitation Model Is Alleviated by sulforaphane's Anti-Inflammatory and Antioxidant Action

Hemorrhagic shock/resuscitation (HS/R) can lead to acute kidney injury, mainly manifested as oxidative stress and inflammatory injury in the renal tubular epithelial cells, as well as abnormal autophagy and apoptosis. Sulforaphane (SFN), an agonist of the nuclear factor-erythroid factor 2-related factor 2 (Nrf2) signaling pathway, is involved in multiple biological activities, such as anti-inflammatory, antioxidant, autophagy, and apoptosis regulation. This study investigated the effect of SFN on acute kidney injury after HS/R in mice. Hemorrhagic shock was induced in mice by controlling the arterial blood pressure at a range of 35-45 mmHg for 90 min within arterial blood withdrawal. Fluid resuscitation was carried out by reintroducing withdrawn blood and 0.9% NaCl. We found that SFN suppressed the elevation of urea nitrogen and serum creatinine levels in the blood induced by HS/R. SFN mitigated pathological alterations including swollen renal tubules and renal casts in kidney tissue of HS/R mice. Inflammation levels and oxidative stress were significantly downregulated in mouse kidney tissue after SFN administration. In addition, the kidney tissue of HS/R mice showed high levels of autophagosomes as observed by electron microscopy. However, SFN can further enhance the formation of autophagosomes in the HS/R + SFN group. SFN also increased autophagy-related proteins Beclin1 expression and suppressed P62 expression, while increasing the ratio of microtubule-associated protein 1 light chain 3 (LC3)-II and LC3-I (LC3-II/LC3-I). SFN also effectively decreased cleaved caspase-3 level and enhanced the ratio of anti-apoptotic protein B cell lymphoma 2 and Bcl2-associated X protein (Bcl2/Bax). Collectively, SFN effectively inhibited inflammation and oxidative stress, enhanced autophagy, thereby reducing HS/R-induced kidney injury and apoptosis levels in mouse kidneys.

An overview of 6-shogaol: new insights into its pharmacological properties and potential therapeutic activities

Ginger (Zingiber officinale Roscoe) has traditionally been used as a cooking spice and herbal medicine for treating nausea and vomiting. More recently, ginger was found to effectively reduce the risk of diseases such as gastroenteritis, migraine, gonarthritis, etc., due to its various bioactive compounds. 6-Shogaol, the pungent phenolic substance in ginger, is the most pharmacologically active among such compounds. The aim of the present study was to review the pharmacological characteristic of 6-shogaol, including the properties of anti-inflammatory, antioxidant and antitumour, and its corresponding molecular mechanism. With its multiple mechanisms, 6-shogaol is considered a beneficial natural compound, and therefore, this review will shed some light on the therapeutic role of 6-shogaol and provide a theoretical basis for the development and clinical application of 6-shogaol.

Melatonin regulates the antioxidant capacity of sheep granulosa cells through a novel uORF-Nrf2aa mediated Nrf2/KEAP1 pathway

Ovarian dysfunction stands as a prevalent contributor to female infertility, with its etiology intertwined with genetic, autoimmune, and environmental factors. Within the ovarian follicles, granulosa cells (GCs) represent the predominant cell population. Alterations in GCs, notably oxidative stress (OS) and the consequential surge in reactive oxygen species (ROS), play pivotal roles in the orchestration of ovarian function. Nrf2aa, a newly identified upstream open reading frame (uORF), is situated within the 5' untranslated region (5'UTR) of sheep Nrf2 mRNA and is regulated by melatonin, a crucial intrafollicular antioxidant. In this study, we have noted that Nrf2aa has the capacity to encode a peptide and exerts a negative regulatory effect on the translation efficiency (TE) of the Nrf2 CDs region. Further in vitro experiments, we observed that interfering with Nrf2aa can enhance the cellular functionality of GCs under 3-np-induced oxidative stress, while overexpressing Nrf2aa has the opposite effect. Furthermore, overexpression of Nrf2aa counteracts the rescuing effect of melatonin on the cellular functions of GCs under oxidative stress conditions, including estrogen secretion, proliferation, apoptosis, and many more. Finally, we confirmed that Nrf2aa, by regulating the expression of key proteins in the Nrf2/KEAP1 signaling pathway, further modulates the antioxidant levels in GCs.

Oxidative and carbonyl stress induced AMD and Codonopsis lanceolata ameliorates AMD via controlling oxidative and carbonyl stress

Age-related macular degeneration (AMD) is one of the leading causes of blindness. AMD is currently incurable; the best solution is to prevent its occurrence. To develop drugs for AMD, it is crucial to have a model system that mimics the symptoms and mechanisms in patients. It is most important to develop safer and more effective anti-AMD drug. In this study, the dose of A2E and the intensity of blue light were evaluated to establish an appropriate atrophic in vitro model of AMD and anti-AMD effect and therapeutic mechanism of Codonopsis lanceolata. The experimental groups included a control group an AMD group treated with A2E and blue light, a lutein group treated with 25 μM lutein after AMD induction, and three groups treated with different doses of C. lanceolata (10, 20, and 50 μg/mL) after AMD induction. Intrinsic apoptotic pathway (Bcl-2 family), anti-oxidative system (Keap1/Nrf2/HO-1 antioxidant response element), and anti-carbonyl effect (4-hydroxynonenal [4-HNE]) were evaluated using immunofluorescence, MTT, TUNEL, FACS, and western blotting analyses. A2E accumulation in the cytoplasm of ARPE-19 cells depending on the dose of A2E. Cell viability of ARPE-19 cells according to the dose of A2E and/or blue light intensity. The population of apoptotic or necrotic cells increased based on the A2E dose and blue light intensity. Codonopsis lanceolata dose-dependently prevented cell death which was induced by A2E and blue light. The antiapoptotic effect of that was caused by activating Keap1/Nrf2/HO-1 pathway, suppressing 4-HNE, and modulating Bcl-2 family proteins like increase of antiapoptotic proteins such as Bcl-2 and Bcl-XL and decrease of proapoptotic protein such as Bim. Based on these findings, 30 μM A2E and 20 mW/cm2 blue light on adult retinal pigment epithelium-19 cells was an appropriate condition for AMD model and C. lanceolata shows promise as an anti-AMD agent.

Regulation of Keap1-Nrf2 signaling in health and diseases

Nuclear factor erythroid 2-related factor 2 (Nrf2) functions as a central regulator in modulating the activities of diverse antioxidant enzymes, maintaining cellular redox balance, and responding to oxidative stress (OS). Kelch-like ECH-associated protein 1 (Keap1) serves as a principal negative modulator in controlling the expression of detoxification and antioxidant genes. It is widely accepted that OS plays a pivotal role in the pathogenesis of various diseases. When OS occurs, leading to inflammatory infiltration of neutrophils, increased secretion of proteases, and the generation of large quantities of reactive oxygen radicals (ROS). These ROS can oxidize or disrupt DNA, lipids, and proteins either directly or indirectly. They also cause gene mutations, lipid peroxidation, and protein denaturation, all of which can result in disease. The Keap1-Nrf2 signaling pathway regulates the balance between oxidants and antioxidants in vivo, maintains the stability of the intracellular environment, and promotes cell growth and repair. However, the antioxidant properties of the Keap1-Nrf2 signaling pathway are reduced in disease. This review overviews the mechanisms of OS generation, the biological properties of Keap1-Nrf2, and the regulatory role of its pathway in health and disease, to explore therapeutic strategies for the Keap1-Nrf2 signaling pathway in different diseases.

The role of oxidative stress in aortic dissection: a potential therapeutic target

The incidence of aortic dissection (AD) is steadily increasing, driven by the rising prevalence of chronic conditions such as hypertension and the global aging of the population. Oxidative stress emerges as a pivotal pathophysiological mechanism contributing to the progression of AD. Oxidative stress triggers apoptosis in vascular smooth muscle cells, reshapes the extracellular matrix (ECM), and governs ECM degradation and remodeling, subsequently impacting aortic compliance. Furthermore, oxidative stress not only facilitates the infiltration of macrophages and mononuclear lymphocytes but also disrupts the integral structure and functionality of endothelial cells, thereby inducing endothelial cell dysfunction and furthering the degeneration of the middle layer of the aortic wall. Investigating antioxidants holds promise as a therapeutic avenue for addressing AD.

Promoting reactive oxygen species accumulation to overcome tyrosine kinase inhibitor resistance in cancer

BACKGROUND

In tumor treatment, protein tyrosine kinase inhibitors (TKIs) have been extensively utilized. However, the efficacy of TKI is significantly compromised by drug resistance. Consequently, finding an effective solution to overcome TKI resistance becomes crucial. Reactive oxygen species (ROS) are a group of highly active molecules that play important roles in targeted cancer therapy including TKI targeted therapy. In this review, we concentrate on the ROS-associated mechanisms of TKI lethality in tumors and strategies for regulating ROS to reverse TKI resistance in cancer.

MAIN BODY

Elevated ROS levels often manifest during TKI therapy in cancers, potentially causing organelle damage and cell death, which are critical to the success of TKIs in eradicating cancer cells. However, it is noteworthy that cancer cells might initiate resistance pathways to shield themselves from ROS-induced damage, leading to TKI resistance. Addressing this challenge involves blocking these resistance pathways, for instance, the NRF2-KEAP1 axis and protective autophagy, to promote ROS accumulation in cells, thereby resensitizing drug-resistant cancer cells to TKIs. Additional effective approaches inducing ROS generation within drug-resistant cells and providing exogenous ROS stimulation.

CONCLUSION

ROS play pivotal roles in the eradication of tumor cells by TKI. Harnessing the accumulation of ROS to overcome TKI resistance is an effective and widely applicable approach.

Chemopreventive effects of atractylenolide-III on mammary tumorigenesis via activation of the Nrf2/ARE pathway through autophagic degradation of Keap1

The incidence of breast cancer is increasing annually, making it a major health threat for women. Chemoprevention using natural, dietary, or synthetic products has emerged as a promising approach to address this growing burden. Atractylenolide-III (AT-III), a sesquiterpenoid present in various medicinal herbs, has demonstrated potential therapeutic effects against several diseases, including tumors, nonalcoholic fatty liver disease, and cerebral ischemic injury. However, its impact on breast cancer chemoprevention remains unexplored. In this study, we used an N-methyl-N-nitrosourea (NMU)-induced rat breast cancer model and 17β-estradiol (E2)-treated MCF-10A cells to evaluate the chemopreventive potential of AT-III on mammary tumorigenesis. AT-III inhibited mammary tumor progression, evidenced by reduced tumor volume and multiplicity, prolonged tumor latency, and the reversal of NMU-induced weight loss. Furthermore, AT-III suppressed NMU-induced inflammation and oxidative stress through the Nrf2/ARE pathway in breast cancer tissues. In vitro, AT-III effectively suppressed E2-induced anchorage-independent growth and cell migration in MCF-10A cells. Nrf2 knockdown attenuated the protective effects of AT-III, highlighting the pivotal role of Nrf2 in AT-III-mediated suppression of tumorigenesis. The mechanism involves the induction of Nrf2 expression by AT-III through the autophagic degradation of Kelch-like ECH-associated protein 1 (Keap1). Overall, the results of this study indicate that AT-III is a promising candidate for breast cancer chemoprevention and provide valuable insights into its molecular interactions and signaling pathways.

MCL restrained ROS/AKT/ASAH1 pathway to therapy tamoxifen resistance breast cancer by stabilizing NRF2

Tamoxifen resistance is a common and difficult problem in the clinical treatment of breast cancer (BC). As a novel antitumor agent, Micheliolide (MCL) has shown a better therapeutic effect on tumours; however, little is known about MCL and its role in BC therapy. With tamoxifen stimulation, drug-resistant BC cells MCF7TAMR and T47DTAMR obtained a high oxidative status and Amidohydrolase 1 (ASAH1) was abnormally activated. The inhibition of ASAH1 rescued the sensitivity of resistant cells to tamoxifen. We found that MCL inhibited the expression of ASAH1 and cell proliferation, especially in MCF7TAMR and T47DTAMR cells. The high oxidative stress status of resistant cells stimulated the expression of ASAH1 by positively regulating AKT, which was restrained by MCL. MCL activated NRF2 by directly binding to KEAP1 and promoting the antioxidant level of tamoxifen-resistant (TAMR) cells. In addition, ACT001, the prodrug of MCL, significantly inhibited the tumour growth of TAMR cells in preclinical xenograft tumour models. In conclusion, ASAH1 mediates tamoxifen resistance in ER-positive BC cells. MCL could activate the cellular antioxidant system via NRF2/KEAP1 and inhibit ASAH1 expression through the ROS/AKT signalling pathway, thus suppressing cell proliferation. MCL could be used as a potential treatment for TAMR-BC.

Bivalent inhibitors of the BTB E3 ligase KEAP1 enable instant NRF2 activation to suppress acute inflammatory response

Most BTB-containing E3 ligases homodimerize to recognize a single substrate by engaging multiple degrons, represented by E3 ligase KEAP1 dimer and its substrate NRF2. Inactivating KEAP1 to hinder ubiquitination-dependent NRF2 degradation activates NRF2. While various KEAP1 inhibitors have been reported, all reported inhibitors bind to KEAP1 in a monovalent fashion and activate NRF2 in a lagging manner. Herein, we report a unique bivalent KEAP1 inhibitor, biKEAP1 (3), that engages cellular KEAP1 dimer to directly release sequestered NRF2 protein, leading to an instant NRF2 activation. 3 promotes the nuclear translocation of NRF2, directly suppressing proinflammatory cytokine transcription. Data from in vivo experiments showed that 3, with unprecedented potency, reduced acute inflammatory burden in several acute inflammation models in a timely manner. Our findings demonstrate that the bivalent KEAP1 inhibitor can directly enable sequestered substrate NRF2 to suppress inflammatory transcription response and dampen various acute inflammation injuries.

KEAP1 overexpression is correlated with poor prognosis and immune infiltration in liver hepatocellular carcinoma

Purpose

Liver hepatocellular carcinoma (LIHC) is the most common type of liver cancer, but there is a lack of effective indicators for its early diagnosis and prognosis, so we explored the role of KEAP1 in LIHC patients in this study.

Methods

The Cancer Genome Atlas (TCGA) dataset was used to investigate the relationship between KEAP1 expression and clinicopathological features and prognosis of LIHC patients. KEAP1 expression related pathways were enriched by Gene Ontology (GO) and gene set enrichment analysis (GSEA). Besides, KEAP1 expression-related immune infiltration was performed by single-sample GSEA (ssGSEA), and function of immune cells was detected by flow cytometry.

Results

It was found that KEAP1 expression was significantly increased and correlated with overall survival of LIHC patients. A total of 231 differentially expressed genes (DEGs) between LIHC patients with high- and low-KEAP1 expression were found, which associated with various biological pathways. Besides, KEAP1 expression was positively correlated with the infiltration level of T helper cells and Th2 cells but negatively correlated with DCs and cytotoxic cells. Functional analysis revealed that the expression of IL 4 in Th2 cells and CD107a, GrA and GrB in cytotoxic cells was significantly greater in LIHC patients than in HCs. In addition, KEAP1 expression was closely correlated with liver function in LIHC patients.

Conclusion

Highly expressed KEAP1 was closely related to the diagnosis, prognosis, immune cell infiltration, and liver function of LIHC, which might promote the progression of LIHC through regulating cell development, signal transduction, and abnormal immune response. The current study partially revealed the role of KEAP1 in LIHC and provided a potential biomarker for the diagnosis, prognosis and treatment of LIHC.

miR-141-3p attenuates inflammation and oxidative stress-induced pulmonary fibrosis in ARDS via the Keap1/Nrf2/ARE signaling pathway

The present research aimed to investigate the effects and mechanisms of microRNA (miR)-141-3p on pulmonary fibrosis of acute respiratory distress syndrome (ARDS). A rat ARDS model was established by the intratracheal drip of 10 mg/kg lipopolysaccharide (LPS). miR-141-3p and Kelch-like ECH-associated protein 1 (Keap1) expression was detected using RT-qPCR assay. Inflammatory factors in bronchoalveolar lavage fluid (BALF) and lung tissues were measured with enzyme-linked immunosorbent assay (ELISA). Lung fibrosis was evaluated using Masson's trichrome staining and hydroxyproline assay kits. Tissue oxidative stress marker levels were assessed by a commercial kit. Protein variations in the EMT pathway and Keap1/nuclear factor-erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway were investigated by Western blot analysis. Targeting relationship verified by dual-luciferase reporter assay. The expression of miR-141-3p was significantly upregulated in LPS-induced ARDS rats, while Keap1 was downregulated. Overexpression of miR-141-3p decreased the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, superoxide dismutase (SOD), and glutathione (GSH) while elevating malondialdehyde (MDA) expression in LPS-induced ARDS rats. Elevation of miR-141-3p reduced fibrosis scores, enhanced E-cadherin protein expression, and decreased vimentin and α-SMA protein expression in LPS-induced ARDS rats. This elevation of miR-141-3p also upregulated Nrf2, heme oxygenase-1 (HO-1), and NAD(P)H:quinone oxido-reductase-1 (NQO1) proteins levels. Moreover, Keap1 overexpression reversed the inhibitory effects of miR-141-3p on LPS-triggered inflammation, oxidative stress, and fibrosis. miR-141-3p may attenuate inflammation and oxidative stress-induced pulmonary fibrosis in ARDS via the Keap1/Nrf2/ARE signaling pathway. Our study provides new ideas for the treatment of ARDS.

Ethanol extract of Eclipta prostrata induces multiple myeloma ferroptosis via Keap1/Nrf2/HO-1 axis

BACKGROUND

Multiple myeloma (MM) is an incurable hematological malignancy with limited therapeutic efficacy. Eclipta prostrata is a traditional Chinese medicinal plant reported to possess antitumor properties. However, the effects of E. prostrata in MM have not been explored.

PURPOSE

The aim of this study was to define the mechanism of the ethanol extract of E. prostrata (EEEP) in treating MM and identify its major components.

METHODS

The pro-ferroptotic effects of EEEP on cell death, cell proliferation, iron accumulation, lipid peroxidation, and mitochondrial morphology were determined in RPMI-8226 and U266 cells. The expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), kelch-like ECH-associated protein 1 (Keap1), heme oxygenase-1 (HO-1), glutathione peroxidase 4 (GPX4), and 4-hydroxynonenal (4HNE) were detected using western blotting during EEEP-mediated ferroptosis regulation. The RPMI-8226 and U266 xenograft mouse models were used to explore the in vivo anticancer effects of EEEP. Finally, high performance liquid chromatography (HPLC) and ultra-high-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry system (UPLC-Q/TOF-MS) were used to identify the major constituents of EEEP.

RESULTS

EEEP inhibited MM cell growth and induced cell death in vitro and in vivo. By promoting malondialdehyde and Fe2+ accumulation, lipid peroxidation, and GSH suppression, EEEP triggers ferroptosis in MM. Mechanistically, EEEP regulates the Keap1/Nrf2/HO-1 axis and stimulates ferroptosis. EEEP-induced lipid peroxidation and malondialdehyde accumulation were blocked by the Nrf2 activator NK-252. In addition, HPLC and UPLC-Q/TOF-MS analysis elucidated the main components of EEEP, including demethylwedelolactone, wedelolactone, chlorogenic acid and apigenin, which may play important roles in the anti-tumor function of EEEP.

CONCLUSION

In summary, EEEP exerts its anti-MM function by inducing MM cell death and inhibiting tumor growth in mice. We also showed that EEEP can induce lipid peroxidation and accumulation of ferrous irons in MM cells both in vivo and in vitro, leading to ferroptosis. In addition, this anti-tumor function may be achieved by the EEEP activation of Keap1/Nrf2/HO-1 axis. This is the first study to reveal that EEEP exerts anti-MM activity through the Keap1/Nrf2/HO-1-dependent ferroptosis regulatory axis, making it a promising candidate for MM treatment.

Shizukaol C alleviates trimethylamine oxide-induced inflammation through activating Keap1-Nrf2-GSTpi pathway in vascular smooth muscle cell

BACKGROUND

Cardiovascular disease is one of the main causes of global mortality, and there is an urgent need for effective treatment strategies. Gut microbiota-dependent metabolite trimethylamine-N-oxide (TMAO) promotes the development of cardiovascular diseases, and shizukaol C, a natural sesquiterpene isolated from Chloranthus multistachys with various biological activities, might exhibit beneficial role in preventing TMAO-induced vascular inflammation.

PURPOSE

The purpose of this study was to investigate the anti-inflammatory effects and the underlying mechanisms of shizukaol C on TMAO-induced vascular inflammation.

METHODS

The effect and underlying mechanism of shizukaol C on TMAO-induced adhesion molecules expression, bone marrow-derived macrophages (BMDM) adhesion to VSMC were evaluated by western blot, cell adhesion assay, co-immunoprecipitation, immunofluorescence assay, and quantitative Real-Time PCR, respectively. To verify the role of shizukaol C in vivo, TMAO-induced vascular inflammation model were established using guidewire-induced injury on mice carotid artery. Changes in the intima area and the expression of GSTpi, VCAM-1, CD68 were examined using haematoxylin-eosin staining, and immunofluorescence assay.

RESULTS

Our data demonstrated that shizukaol C significantly suppressed TMAO-induced adhesion molecule expression and the bone marrow-derived macrophages (BMDM) adhesion in vascular smooth muscle cells (VSMC). Mechanically, shizukaol C inhibited TMAO-induced c-Jun N-terminal kinase (JNK)-nuclear factor-kappa B (NF-κB)/p65 activation, and the JNK inhibition was dependent on the shizukaol C-mediated glutathione-S-transferase pi (GSTpi) expression. By further molecular docking and protein-binding analysis, we demonstrated that shizukaol C directly binds to Keap1 to induce Nrf2 nuclear translocation and upregulated GSTpi expression. Consistently, our in vivo experiment showed that shizukaol C elevated the expression level of GSTpi in carotid arteries and alleviates TMAO-induced vascular inflammation.

CONCLUSION

Shizukaol C exerts anti-inflammatory effects in TMAO-treated VSMC by targeting Keap1 and activating Nrf2-GSTpi signaling and resultantly inhibits the downstream JNK-NF-κB/p65 activation and VSMC adhesion, and alleviates TMAO-induced vascular inflammation in vivo, suggesting that shizukaol C may be a potential drug for treating TMAO-induced vascular diseases.

Albizzia chinensis (Osbeck) Merr extract YS ameliorates ethanol-induced acute gastric ulcer injury in rats by regulating NRF2 signaling pathway

BACKGROUND

Around the world, there is a high incidence of gastric ulcers. YS, an extract from the Chinese herb Albizzia chinensis (Osbeck) Merr, has potential therapeutic applications for gastrointestinal diseases. Here we elucidated the protective effect and underlying mechanism of action of YS on gastric ulcer in rats injured by ethanol.

METHODS

The ethanol-induced gastric ulcer rat model was used to assess the protective effect of YS. A pathological examination of gastric tissue was performed by H&E staining. GES-1 cells damaged by hydrogen peroxide were used to simulate oxidative damage in gastric mucosal epithelial cells. Endogenous NRF2 was knocked down using small interfering RNA. Immunoprecipitation was used to detect ubiquitination of NRF2. Co-immunoprecipitation was used to detect the NRF2-Keap1 interaction.

RESULTS

YS (10 and 30 mg/kg, i.g.) significantly reduced the ulcer index, decreased MDA level, and increased SOD and GSH levels in gastric tissues damaged by ethanol. YS promoted NRF2 translocation from cytoplasm to nucleus and enhanced the NQO1 and HO-1 expression levels in injured rat gastric tissue. In addition, YS regulated NQO1 and HO-1 via NRF2 in H2O2-induced oxidative injured GES-1 cells. Further studies on the underlying mechanism indicated that YS reduced the interaction between NRF2 and Keap1 and decreased ubiquitylation of NRF2, thereby increasing its stability and expression of downstream factors. NRF2 knockdown abolished the effect of YS on MDA and SOD in GES-1 cells treated with H2O2.

CONCLUSION

YS reduced the NRF2-Keap1 interaction, promoting NRF2 translocation into the nucleus, which increasing the transcription and translation of NQO1 and HO-1 and improved the antioxidant capacity of rat stomach.

Targeting NF-κB in Hepatic Ischemia-Reperfusion Alleviation: from Signaling Networks to Therapeutic Targeting

Hepatic ischemia-reperfusion injury (HIRI) is a major complication of liver trauma, resection, and transplantation that can lead to liver dysfunction and failure. Scholars have proposed a variety of liver protection methods aimed at reducing ischemia-reperfusion damage, but there is still a lack of effective treatment methods, which urgently needs to find new effective treatment methods for patients. Many studies have reported that signaling pathway plays a key role in HIRI pathological process and liver function recovery mechanism, among which nuclear transfer factor-κB (NF-κB) signaling pathway is one of the signal transduction closely related to disease. NF-κB pathway is closely related to HIRI pathologic process, and inhibition of this pathway can delay oxidative stress, inflammatory response, cell death, and mitochondrial dysfunction. In addition, NF-κB can also interact with PI3K/Akt, MAPK, and Nrf2 signaling pathways to participate in HIRI regulation. Based on the role of NF-κB pathway in HIRI, it may be a potential target pathway for HIRI. This review emphasizes the role of inhibiting the NF-κB signaling pathway in oxidative stress, inflammatory response, cell death, and mitochondrial dysfunction in HIRI, as well as the effects of related drugs or inhibitors targeting NF-κB on HIRI. The objective of this review is to elucidate the role and mechanism of NF-κB pathway in HIRI, emphasize the important role of NF-κB pathway in the prevention and treatment of HIRI, and provide a theoretical basis for the target NF-κB pathway as a therapy for HIRI.

Edaravone dexborneol attenuates oxidative stress in experimental subarachnoid hemorrhage via Keap1/Nrf2 signaling pathway

Background

Subarachnoid hemorrhage (SAH) serves as a disease characterized by high incidence rate, which is exceedingly prevalent and severe. Presently, there is no unambiguous or efficacious intervention for the neurological impairment following SAH. Administering multi-targeted neuroprotective agents to reduce oxidative stress (OS) and neuroinflammation caused by early brain injury (EBI) has been demonstrated to improve neurological function and prognosis following SAH. Edaravone dexborneol (EDB), a novel multi targeted neuroprotective medication, combines four parts edaravone (EDA) with 1 part (+)-borneol in proportion. Clinical trials conducted in China have revealed during 2 days of acute ischemic stroke (AIS), early administration of EDB leads to improved therapeutic outcomes compared to treatment in EDA monotherapy. Currently, there is no clear evidence that EDB can effectively treat SAH, therefore, our study aims to investigate its potential therapeutic effects and mechanisms on EBI after SAH.

Method

We used the intravascular threading method to establish a mouse model of SAH to explore whether EDA and EDB could produce anti-OS and anti-apoptosis effects. Behavioral assessment of mice was conducted using the balance beam experiment and the modified Garcia scoring system. Neuronal damage due to OS and Keap1/Nrf2 signaling pathway were detected through techniques of immunofluorescence, Western blotting, spectrophotometry. The group of EDA and EDB were injected intraperitoneally for 72 h after SAH.

Results

The experiment results indicated that EDB lead to remarkably positive results by significantly enhancing neurological function, reducing blood-brain barrier (BBB) injury, and effectively inhibiting neuronal apoptosis after SAH. Further examination indicated EDB significantly reduced the expression of Keap1 and increased the expression of Nrf2, and it inhibited MDA, and enhanced SOD activity after SAH. These outcomes surpassed the effectiveness observed in EDA monotherapy. However, the application of ML385 reversed the anti-OS effects of EDB and EDA.

Conclusion

Our experimental findings indicated that EDB could activate Keap1/Nrf2 signaling pathway to reduce OS damage, thereby protecting neurological function and enhancing behavioral abilities after SAH. These outcomes could facilitate the creation of new approaches for the clinical management of SAH.

Chondrocyte-targeted exosome-mediated delivery of Nrf2 alleviates cartilaginous endplate degeneration by modulating mitochondrial fission

BACKGROUND

Cartilaginous endplate (CEP) degeneration, which is an important contributor to intervertebral disc degeneration (IVDD), is characterized by chondrocyte death. Accumulating evidence has revealed that dynamin-related protein 1 (Drp1)-mediated mitochondrial fission and dysfunction lead to apoptosis during CEP degeneration and IVDD. Exosomes are promising agents for the treatment of many diseases, including osteoporosis, osteosarcoma, osteoarthritis and IVDD. Despite their major success in drug delivery, the full potential of exosomes remains untapped.

MATERIALS AND METHODS

In vitro and in vivo models of CEP degeneration were established by using lipopolysaccharide (LPS). We designed genetically engineered exosomes (CAP-Nrf2-Exos) expressing chondrocyte-affinity peptide (CAP) on the surface and carrying the antioxidant transcription factor nuclear factor E2-related factor 2 (Nrf2). The affinity between CAP-Nrf2-Exos and CEP was evaluated by in vitro internalization assays and in vivo imaging assays. qRT‒PCR, Western blotting and immunofluorescence assays were performed to examine the expression level of Nrf2 and the subcellular localization of Nrf2 and Drp1. Mitochondrial function was measured by the JC-1 probe and MitoSOX Red. Mitochondrial morphology was visualized by MitoTracker staining and transmission electron microscopy (TEM). After subendplate injection of the engineered exosomes, the degree of CEP degeneration and IVDD was validated radiologically and histologically.

RESULTS

We found that the cargo delivery efficiency of exosomes after cargo packaging was increased by surface modification. CAP-Nrf2-Exos facilitated chondrocyte-targeted delivery of Nrf2 and activated the endogenous antioxidant defence system in CEP cells. The engineered exosomes inhibited Drp1 S616 phosphorylation and mitochondrial translocation, thereby preventing mitochondrial fragmentation and dysfunction. LPS-induced CEP cell apoptosis was alleviated by CAP-Nrf2-Exo treatment. In a rat model of CEP degeneration, the engineered exosomes successfully attenuated CEP degeneration and IVDD and exhibited better repair capacity than natural exosomes.

CONCLUSION

Collectively, our findings showed that exosome-mediated chondrocyte-targeted delivery of Nrf2 was an effective strategy for treating CEP degeneration.

CBX7 silencing promoted liver regeneration by interacting with BMI1 and activating the Nrf2/ARE signaling pathway

Multiple studies have shown knockdown of chromobox 7 (CBX7) promotes the regenerative capacity of various cells or tissues. We examined the effect of CBX7 on hepatocyte proliferation and liver regeneration after 2/3 hepatectomy in a mouse model. For in vitro experiments, NCTC 1469 and BNL CL.2 hepatocytes were co-transfected with siRNA-CBX7-1 (si-CBX7-1), siRNA-CBX7-2 (si-CBX7-2), pcDNA-CBX7, si-BMI1-1, si-BMI1-2, pcDNA-BMI1, or their negative control. For in vivo experiments, mice were injected intraperitoneally with lentivirus-packaged shRNA and shRNA CBX7 before hepatectomy. Our results showed that CBX7 was rapidly induced in the early stage of liver regeneration. CBX7 regulated hepatocyte proliferation, cell cycle, and apoptosis of NCTC 1469 and BNL CL.2 hepatocytes. CBX7 interacted with BMI1 and inhibited BMI1 expression in hepatocytes. Silencing BMI1 aggregated the inhibitory effect of CBX7 overexpression on hepatocyte viability and the promotion of apoptosis. Furthermore, silencing BMI1 enhanced the regulatory effect of CBX7 on Nrf2/ARE signaling in HGF-induced hepatocytes. In vivo, CBX7 silencing enhanced liver/body weight ratio in PH mice. CBX7 silencing promoted the Ki67-positive cell count and decreased the Tunel-positive cell count after hepatectomy, and also increased the expression of nuclear Nrf2, HO-1, and NQO-1. Our results suggest that CBX7 silencing may increase survival following hepatectomy by promoting liver regeneration.

Indole-3-carbinol ameliorates ovarian damage in female old mice through Nrf2/HO-1 pathway activation

Ovarian aging leads to infertility and birth defects. We aimed to clarify the role of Indole-3-carbinol (I3C) in resistance to oxidative stress, apoptosis, and fibrosis in ovarian aging. I3C was administered via intraperitoneal injection for 3 weeks in young or old mice. Immunohistochemistry; Masson, Sirius red, and TUNEL staining; follicle counting; estrous cycle analysis; and Western blotting were used for validating the protective effect of I3C against ovarian senescence. Human granulosa-like tumor cell line and primary granulosa cells were used for in vitro assay. The results indicated that I3C inhibited ovarian fibrosis and apoptosis while increasing the number of primordial follicles. Mechanistic studies have shown that I3C promoted the nuclear translocation of nuclear factor-erythroid 2-related factor (Nrf2) and upregulated the expression of heme oxygenase 1 (HO-1). Additionally, I3C increased cell viability and decreased lactate dehydrogenase, malondialdehyde, reactive oxygen species and JC-1 levels. Furthermore, the antioxidant effect of I3C was found to be dependent on the activation of Nrf2 and HO-1, as demonstrated by the disappearance of the effect upon inhibition of Nrf2 expression. In conclusion, I3C can alleviate the ovarian damage caused by aging and may be a protective agent to delay ovarian aging.

Combined exposure of nano-titanium dioxide and polystyrene nanoplastics exacerbate oxidative stress-induced liver injury in mice by regulating the Keap-1/Nrf2/ARE pathway

It is well known that polystyrene nanoplastics (PS-NaP) and nano-titanium dioxide (TiO2 NPs) are frequently co-appeared in daily life and can cause liver injury when they accumulate in the liver. Nonetheless, the combined toxicological impacts and potential molecular mechanisms of PS-NaP and TiO2 NPs in the hepatic system have not been revealed. Thus, we conducted experiments on C57BL/6 mice exposed to PS-NaP or/and TiO2 NPs for 4 weeks. The findings suggested that PS-NaP and TiO2 NPs co-exposed significantly altered the hepatic function parameters, levels of antioxidant-related enzymes and genes expression of Keap-1/Nrf2/ARE signaling pathway, as well as significantly increased the hepatic Ti contents, aggravated hepatic pathological and oxidative stress (OS) damage compared with individual exposure to PS-NaP or TiO2 NPs. Using N-Acetyl-L-cysteine (NAC), an OS inhibitor, we further demonstrated that OS played a pivotal role in coexposure-induced liver injury. NAC reduced the levels of OS in mice, which mitigated co-exposure-induced liver injury. Taken together, we proposed that PS-NaP and TiO2 NPs co-exposed activated the Keap-1, then inhibited the recognition of Nrf2 and ARE, consequently exacerbated liver injury. These findings shed light on the co-toxicity and potential mechanism of nanoplastics and nanoparticles, which informed the risk assessment of human exposure to environmental pollutants.

GSTP alleviates acute lung injury by S-glutathionylation of KEAP1 and subsequent activation of NRF2 pathway

Oxidative stress plays an important role in the pathogenesis of acute lung injury (ALI). As a typical post-translational modification triggered by oxidative stress, protein S-glutathionylation (PSSG) is regulated by redox signaling pathways and plays diverse roles in oxidative stress conditions. In this study, we found that GSTP downregulation exacerbated LPS-induced injury in human lung epithelial cells and in mice ALI models, confirming the protective effect of GSTP against ALI both in vitro and in vivo. Additionally, a positive correlation was observed between total PSSG level and GSTP expression level in cells and mice lung tissues. Further results demonstrated that GSTP inhibited KEAP1-NRF2 interaction by promoting PSSG process of KEAP1. By the integration of protein mass spectrometry, molecular docking, and site-mutation validation assays, we identified C434 in KEAP1 as the key PSSG site catalyzed by GSTP, which promoted the dissociation of KEAP1-NRF2 complex and activated the subsequent anti-oxidant genes. In vivo experiments with AAV-GSTP mice confirmed that GSTP inhibited LPS-induced lung inflammation by promoting PSSG of KEAP1 and activating the NRF2 downstream antioxidant pathways. Collectively, this study revealed the novel regulatory mechanism of GSTP in the anti-inflammatory function of lungs by modulating PSSG of KEAP1 and the subsequent KEAP1/NRF2 pathway. Targeting at manipulation of GSTP level or activity might be a promising therapeutic strategy for oxidative stress-induced ALI progression.

A Gene-Switch Platform Interfacing with Reactive Oxygen Species Enables Transcription Fine-Tuning by Soluble and Volatile Pharmacologics and Food Additives

Synthetic biology aims to engineer transgene switches for precise therapeutic protein control in cell-based gene therapies. However, off-the-shelf trigger-inducible gene circuits are usually switched on by single or structurally similar molecules. This study presents a mammalian gene-switch platform that controls therapeutic gene expression by a wide range of molecules generating low, non-toxic levels of reactive oxygen species (ROS). In this system, KEAP1 (Kelch-like ECH-associated protein 1) serves as ROS sensor, regulating the translocation of NRF2 (nuclear factor erythroid 2-related factor 2) to the nucleus, where NRF2 binds to  antioxidant response elements (ARE) to activate the expression of a gene of interest. It is found that a promoter containing eight-tandem ARE repeats is highly sensitive to the low ROS levels generated by the soluble and volatile molecules, which include food preservatives, food additives, pharmaceuticals, and signal transduction inducers. In a proof-of-concept study, it is shown that many of these compounds can independently trigger microencapsulated engineered cells to produce sufficient insulin to restore normoglycemia in experimental type-1 diabetic mice. It is believed that this system greatly extends the variety of small-molecule inducers available to drive therapeutic gene switches.

Bilirubin ameliorates osteoarthritis via activating Nrf2/HO-1 pathway and suppressing NF-κB signalling

Osteoarthritis (OA) is a chronic degenerative joint disease that affects worldwide. Oxidative stress plays a critical role in the chronic inflammation and OA progression. Scavenging overproduced reactive oxygen species (ROS) could be rational strategy for OA treatment. Bilirubin (BR) is a potent endogenous antioxidant that can scavenge various ROS and also exhibit anti-inflammatory effects. However, whether BR could exert protection on chondrocytes for OA treatment has not yet been elucidated. Here, chondrocytes were exposed to hydrogen peroxide with or without BR treatment. The cell viability was assessed, and the intracellular ROS, inflammation cytokines were monitored to indicate the state of chondrocytes. In addition, BR was also tested on LPS-treated Raw264.7 cells to test the anti-inflammation property. An in vitro bimimic OA microenvironment was constructed by LPS-treated Raw264.7 and chondrocytes, and BR also exert certain protection for chondrocytes by activating Nrf2/HO-1 pathway and suppressing NF-κB signalling. An ACLT-induced OA model was constructed to test the in vivo therapeutic efficacy of BR. Compared to the clinical used HA, BR significantly reduced cartilage degeneration and delayed OA progression. Overall, our data shows that BR has a protective effect on chondrocytes and can delay OA progression caused by oxidative stress.

Neuroprotective effect of curcumin against experimental autoimmune encephalomyelitis-induced cognitive and physical impairments in mice: an insight into the role of the AMPK/SIRT1 pathway

Multiple sclerosis (MS) is an incurable chronic neurodegenerative disease where autoimmunity, oxidative stress, and neuroinflammation collaboration predispose myelin sheath destruction. Interestingly, curcumin, a natural polyphenol, showed a neuroprotective effect in numerous neurodegenerative diseases, including MS. Nevertheless, the influence of curcumin against MS-induced cognitive impairment is still vague. Hence, we induced experimental autoimmune encephalomyelitis (EAE) in mice using spinal cord homogenate (SCH) and complete Freund's adjuvant, which eventually mimic MS. This study aimed not only to evaluate curcumin efficacy against EAE-induced cognitive and motor dysfunction, but also to explore a novel mechanism of action, by which curcumin exerts its beneficial effects in MS. Curcumin (200 mg/kg/day) efficacy was evaluated by behavioral tests, histopathological examination, and biochemical tests. Concisely, curcumin amended EAE-induced cognitive and motor impairments, as demonstrated by the behavioral tests and histopathological examination of the hippocampus. Interestingly, curcumin activated the adenosine monophosphate (AMP)-activated protein kinase/silent mating type information regulation 2 homolog 1 (AMPK/SIRT1) axis, which triggered cyclic AMP response element-binding protein/brain-derived neurotrophic factor/myelin basic protein (CREB/BDNF/MBP) pathway, hindering demyelination of the corpus callosum. Furthermore, AMPK/SIRT1 activation augmented nuclear factor erythroid 2-related factor 2 (Nrf2), a powerful antioxidant, amending EAE-induced oxidative stress. Additionally, curcumin abolished EAE-induced neuroinflammation by inhibiting Janus kinase 2 /signal transducers and activators of transcription 3 (JAK2/STAT3) axis, by various pathways, including AMPK/SIRT1 activation. JAK2/STAT3 inhibition halts inflammatory cytokines synthesis. In conclusion, curcumin's neuroprotective effect in EAE is controlled, at least in part, by AMPK/SIRT1 activation, which ultimately minimizes EAE-induced neuronal demyelination, oxidative stress, and neuroinflammation.

Aerobic exercise improves BKCa channel-mediated vasodilation in diabetic vascular smooth muscle via AMPK/Nrf2/HO-1 pathway

AIMS

This study aims to investigate the effect of aerobic exercise training on BKCa channel in diabetic vascular smooth muscle and explore the underlying mechanism.

METHODS

Control m/m mice and diabetic db/db mice were randomly assigned to sedentary groups (W and D) and exercise training groups (WE and DE). Mice in exercise groups underwent training sessions lasting for 12 weeks, with a speed of 12 m/min for 60 min, five times per week. The thoracic aorta was extracted isolated and examined for measurement of vascular structure, global levels of reactive oxygen species (ROS), vasodilation, and protein expression. Rat thoracic aorta vascular smooth muscle cells (USMCs) were cultured, and siRNA transfection was conducted to detect whether AMPK contributed to the regulation. ROS level and protein expression were measured.

RESULTS

Compared with control mice, diabetic mice had a larger vascular medium thickness, impaired BKCa-mediated vasodilation, a higher level of ROS, and a lower expression of BKCa α, BKCa β1, Nrf2, p-Nrf2, p-Nrf2/Nrf2, HO-1, and p-AMPK/AMPK. Exercise training increased the expression of BKCa α, Nrf2, p-Nrf2, p-Nrf2/Nrf2, HO-1, and p-AMPK/AMPK. AMPK deletion led to lower ROS levels and expression of BKCa α, β1, Nrf2, and HO-1 in USMCs cultured in high glucose conditions.

CONCLUSIONS

BKCa channel protein expression reduction in VSMCs contributes to vasodilation and vascular remodeling dysfunction in diabetes mellitus. Aerobic exercise can promote the expression of BKCa channel and improve BKCa-mediated vascular dysfunction in diabetic VSMCs through AMPK/Nrf2/HO-1 signaling pathway.

Redox Regulation of Immunometabolism in Microglia Underpinning Diabetic Retinopathy

Diabetic retinopathy (DR) is the leading cause of visual impairment and blindness among the working-age population. Microglia, resident immune cells in the retina, are recognized as crucial drivers in the DR process. Microglia activation is a tightly regulated immunometabolic process. In the early stages of DR, the M1 phenotype commonly shifts from oxidative phosphorylation to aerobic glycolysis for energy production. Emerging evidence suggests that microglia in DR not only engage specific metabolic pathways but also rearrange their oxidation-reduction (redox) system. This redox adaptation supports metabolic reprogramming and offers potential therapeutic strategies using antioxidants. Here, we provide an overview of recent insights into the involvement of reactive oxygen species and the distinct roles played by key cellular antioxidant pathways, including the NADPH oxidase 2 system, which promotes glycolysis via enhanced glucose transporter 4 translocation to the cell membrane through the AKT/mTOR pathway, as well as the involvement of the thioredoxin and nuclear factor E2-related factor 2 antioxidant systems, which maintain microglia in an anti-inflammatory state. Therefore, we highlight the potential for targeting the modulation of microglial redox metabolism to offer new concepts for DR treatment.

Genistein Alleviates Intestinal Oxidative Stress by Activating the Nrf2 Signaling Pathway in IPEC-J2 Cells

In the weaning period, piglets often face oxidative stress, which will cause increased diarrhea and mortality. Genistein, a flavonoid, which is extracted from leguminous plants, possesses anti-inflammatory and antioxidative bioactivities. However, little is known about whether genistein could attenuate the oxidative stress that occurs in porcine intestinal epithelial cells (IPEC-J2). Herein, this experiment was carried out to investigate the protective effects of genistein in the IPEC-J2 cells oxidative stress model. Our results disclosed that H2O2 stimulation brought about a significant diminution in catalase (CAT) activity and cell viability, as well as an increase in the levels of reactive oxygen species (ROS) in IPEC-J2 cells (p < 0.05), whereas pretreating cells with genistein before H2O2 exposure helped to alleviate the reduction in CAT activity and cell viability (p < 0.05) and the raise in the levels of ROS (p = 0.061) caused by H2O2. Furthermore, H2O2 stimulation of IPEC-J2 cells remarkably suppressed gene level Nrf2 and CAT expression, in addition to protein level Nrf2 expression, but pretreating cells with genistein reversed this change (p < 0.05). Moreover, genistein pretreatment prevented the downregulation of occludin expression at the gene and protein level, and ZO-1 expression at gene level (p < 0.05). In summary, our findings indicate that genistein possesses an antioxidant capacity in IPEC-J2 cells which is effective against oxidative stress; the potential mechanism may involve the Nrf2 signaling pathway. Our findings could offer a novel nutritional intervention strategy to enhance the intestinal health of piglets during the weaning process.

Camptothecin enhances the anti-tumor effect of low-dose apatinib combined with PD-1 inhibitor on hepatocellular carcinoma

Apatinib has been shown to apply to a variety of solid tumors, including advanced hepatocellular carcinoma. Preclinical and preliminary clinical results confirmed the synergistic antitumor effects of apatinib in combination with anti-programmed death-1 (PD-1) inhibitors. In this study, we investigated camptothecin (CPT) enhances the anti-tumor effect of low-dose apatinib combined with PD-1 inhibitor on hepatocellular carcinoma. CPT combined with a PD-1 inhibitor enhances the anti-tumor effects of low-dose apatinib in hepatocellular carcinoma which was evaluated in making use of the H22 mouse model (n = 32), which was divided into four groups. Immunohistochemical staining and western blotting were used to detect nuclear factor erythroid 2-related factor 2 (Nrf2) as well as sequestosome 1 (p62), vascular endothelial growth factor A (VEGFA), vascular endothelial growth factor receptor 2 (VEGFR2), PD-1, and programmed cell death ligand 1 (PD-L1). The results showed that the average size of the tumor of the combination group (Group D) was significantly less than that of the apatinib + PD-1 inhibitor group (Group C). The expression levels of Nrf2, p62, VEGFA, VEGFR2, PD-1, and PD-L1 in the apatinib + PD-1 inhibitor group(Group C) were lower than those in the control group (Group A) (P < 0.05). The expression levels of these genes in the apatinib + PD-1 inhibitor group (Group C) were significantly lower in the combination group (Group D) (P < 0.05). There was no obvious difference in body weight and liver and kidney functions between the four groups of mice. In conclusion, CPT improves the anti-tumor effect of low-dose apatinib combined with PD-1 inhibitor on hepatocellular carcinoma.

A review of chemotherapeutic drugs-induced arrhythmia and potential intervention with traditional Chinese medicines

Significant advances in chemotherapy drugs have reduced mortality in patients with malignant tumors. However, chemotherapy-related cardiotoxicity increases the morbidity and mortality of patients, and has become the second leading cause of death after tumor recurrence, which has received more and more attention in recent years. Arrhythmia is one of the common types of chemotherapy-induced cardiotoxicity, and has become a new risk related to chemotherapy treatment, which seriously affects the therapeutic outcome in patients. Traditional Chinese medicine has experienced thousands of years of clinical practice in China, and has accumulated a wealth of medical theories and treatment formulas, which has unique advantages in the prevention and treatment of malignant diseases. Traditional Chinese medicine may reduce the arrhythmic toxicity caused by chemotherapy without affecting the anti-cancer effect. This paper mainly discussed the types and pathogenesis of secondary chemotherapeutic drug-induced arrhythmia (CDIA), and summarized the studies on Chinese medicine compounds, Chinese medicine Combination Formula and Chinese medicine injection that may be beneficial in intervention with secondary CDIA including atrial fibrillation, ventricular arrhythmia and sinus bradycardia, in order to provide reference for clinical prevention and treatment of chemotherapy-induced arrhythmias.

Melatonin alleviates T-2 toxin-induced oxidative damage, inflammatory response, and apoptosis in piglet spleen and thymus

T-2 toxin, an unavoidable contaminant in animal feeds, can induce oxidative stress and damage immune organs. Melatonin (MT), a natural and potent antioxidant, has shown promise as a detoxifier for various mycotoxins. However, the detoxifying effect of MT on T-2 toxin has not been previously reported. In order to investigate the protective effect of MT added to diets on the immune system of T-2 toxin-exposed piglets, twenty piglets weaned at 28d of age were randomly divided into control, T-2 toxin (1 mg/kg), MT (5 mg/kg), and T-2 toxin (1 mg/kg) + MT (5 mg/kg) groups(n = 5 per group). Our results demonstrated that MT mitigated T-2 toxin-induced histoarchitectural alterations in the spleen and thymus, such as hemorrhage, decreased white pulp size in the spleen, and medullary cell sparing in the thymus. Further research revealed that MT promoted the expression of Nrf2 and increased the activities of antioxidant enzymes CAT and SOD, while reducing the production of the lipid peroxidation product MDA. Moreover, MT inhibited the NF-κB signaling pathway, regulated the expression of downstream cytokines IL-1β, IL-6, TNF-α, and TGF-β1. MT also suppressed the activation of caspase-3 while down-regulating the ratio of Bax/Bcl-2 to reduce apoptosis. Additionally, MT ameliorated the T-2 toxin-induced disorders of immune cells and immune molecules in the blood. In conclusion, our findings suggest that MT may effectively protect the immune system of piglets against T-2 toxin-induced damage by inhibiting oxidative stress, inflammatory response, and apoptosis in the spleen and thymus. Therefore, MT holds the potential as an antidote for T-2 toxin poisoning.

Screening approaches for the identification of Nrf2-Keap1 protein-protein interaction inhibitors targeting hot spot residues

Protein-protein interactions (PPIs) play a crucial role in most biological processes and are important targets in the development of therapeutic agents. However, small molecule drug discovery that targets PPIs remains very challenging. Targeting hot spot residues is considered the best option for inhibiting such interactions, but there are few examples of how knowledge of hot spots can be used in high throughput screening to find hit compounds. A substrate adaptor protein for a ubiquitin ligase complex, Kelch-like ECH-associated protein 1 (Keap1), negatively modulates the expression of genes involved in cellular protection against oxidative stress. Here, we focused on three arginine hot spot residues in the Keap1 substrate binding pocket (Arg380, Arg415, and Arg483), and screened the carboxylic acid library owned by Japan Tobacco Inc. for compounds that interact with the arginine residues in differential scanning fluorescence assays. Furthermore, we identified several small molecule compounds that specifically bind to the Keap1 Kelch domain hot spots by comparing binding to alanine mutant proteins (R380A, R415A, and R483A) with binding to the wild-type protein using surface plasmon resonance (SPR) screening. These compounds inhibited the protein-protein interaction between the Keap1 Kelch domain and the nuclear factor erythroid 2-related factor 2 (Nrf2) peptide, and the ubiquitination of Nrf2 catalyzed by the Cul3/RINGBox 1 E3 ligase. In addition, the binding mode of one compound (Compound 4) was determined by X-ray crystallography after validation of binding by isothermal titration calorimetry, native mass spectrometry, and nuclear magnetic resonance. Compound 4 had favorable thermodynamic properties, and noncovalently bound to Keap1 with a stoichiometry of 1:1. Our results suggest that Compound 4 could potentially be developed into effective therapeutic or preventive agents for a variety of diseases and conditions such as oxidative stress response, inflammation, and carcinogenesis. We believe that the use of a set of complementary biophysical techniques including the SPR assay with single alanine mutant of hot spots provides opportunities to identify hit compounds for developing inhibitors of PPIs.

LuQi formula attenuates Cardiomyocyte ferroptosis via activating Nrf2/GPX4 signaling axis in heart failure

BACKGROUND

The terminal stage of all cardiovascular diseases typically culminates in heart failure (HF), with no effective intervention available to halt its progression. LuQi formula (LQF) has been employed in clinical for numerous years to significantly ameliorate cardiac function in HF patients. Nevertheless, the underlying mechanism of LQF's efficacy remains inadequately comprehended. Cardiomyocyte ferroptosis has served as a pathogenic mechanism in HF. The goal of the current experiment was to ascertain whether LQF ameliorates HF by preventing cardiomyocyte ferroptosis and to elucidate the intrinsic mechanism involved.

PURPOSE

This research objective is to investigate the impact and underlying mechanism of LQF attenuating cardiomyocyte ferroptosis in heart failure.

METHODS

Transverse aortic constriction (TAC) was performed to construct the HF mouse model. Neonatal rat cardiomyocytes (NRCMs) were subjected to in vitro experiments. High-performance liquid chromatography (HPLC) identified the bioactive compounds in LQF. Transcriptomic and quantitative proteomic analyses revealed the potential targets of LQF anti-HF. Specifically, histological staining evaluated cardiac hypertrophy and fibrosis. Transmission electron microscopy (TEM) observed mitochondrial morphology. The content of Fe2+, ROS, MDA, GSH, and GSSH was detected using kits. Molecular docking evaluated the binding activities between essential active ingredients of LQF and critical proteins of cardiomyocyte ferroptosis. Mechanistically, the expression levels of Nrf2, Keap1, HO-1, SLC7A11, and GPX4 were evaluated using qPCR, Western blot (WB), or immunohistochemical staining.

RESULTS

The primary nine active ingredients in LQF were detected. Transcriptomic and proteomic analyses demonstrated that LQF may ameliorate HF by preventing cardiomyocyte ferroptosis. Histomorphometric analyses revealed that LQF attenuates myocardial hypertrophy and fibrosis. TEM revealed that LQF diminished mitochondrial shrinkage and increased membrane density in myocardial tissue. Additionally, LQF diminished reactive oxygen species (ROS) generation in cardiomyocytes and suppressed cardiomyocyte ferroptosis. Furthermore, the molecular docking technique revealed that the primary active ingredients of LQF had suitable binding activities with Nrf2, GPX4, and SLC7A11. Western analysis further verified that LQF activated the Nrf2/GPX4 signaling axis. decreased SLC7A11 and HO-1 expression.

CONCLUSIONS

These results demonstrated that LQF prevents cardiomyocyte ferroptosis via activating Nrf2/GPX4 signaling axis and suppressing SLC7A11 and HO-1 expression. Concurrently, it contributed to elucidating the intrinsic mechanism of LQF and provided a scientific rationale for its development as a novel cardiovascular therapeutic drug.

Structure characterization of polysaccharides from Cistanche deserticola and their neuroprotective effects against oxidative stress in slow transit constipation mice

Oxidative stress-induced enteric neuropathy is an important factor in slow transit constipation (STC). Cistanche deserticola crude polysaccharides (CDCP) are natural antioxidants with various biological activities. We prepared CDCP through water-extract and alcohol-precipitation methods. The structural characteristics of CDCP were analyzed by infrared spectroscopy and methylation analysis. The results showed that CDCP was primarily composed of (1 → 4)-linked glucans with minor amounts of pectic polysaccharides. Different doses of CDCP (100, 200, and 400 mg/kg) were administered to loperamide-induced STC mice to explore the therapeutic effects of CDCP. Compared with the untreated group, CDCP treatment significantly improved constipation symptoms, relevant gut-regulating peptides levels, colonic pathological damage, and colonic myenteric nerons injury. CDCP enhanced the antioxidant capacity by decreasing Malondialdehyde (MDA) content, increasing Superoxide Dismutase (SOD) activity and Reduced Glutathione (GSH) content. CDCP significantly reduced oxidative stress-induced injury by preserving mitochondrial function in the colonic myenteric plexus. Furthermore, the neuroprotective effects of CDCP might be associated with the Nrf2/Keap1 pathway. Thus, our findings first revealed the potential of CDCP to protect the colonic myenteric plexus against oxidative stress-induced damage in STC, establishing CDCP as promising candidates for natural medicine in the clinical management of STC.

Ozone-mediated cerebral protection: Unraveling the mechanism through ferroptosis and the NRF2/SLC7A11/GPX4 signaling pathway

BACKGROUND

The pathogenesis of brain ischemic/reperfusion (I/R) insult is characterized by neuronal loss due to excessive oxidative stress responses. Ferroptosis, a form of oxidative cell death, can be triggered when the balance between antioxidants and pro-oxidants in cells is disrupted. Ozone, a natural bioactive molecule with antioxidant/anti-apoptotic and pro-autophagic properties, has been shown to enhance the antioxidant system's capacity and ameliorate oxidative stress. However, its role in neuronal ferroptosis remains unclear. Therefore, we investigated the functions and possible mechanisms of ozone in cerebral I/R-induced ferroptotic neuronal death.

METHODS

A cerebral ischemia-reperfusion injury model was induced in Sprague-Dawley (SD) rats pre-treated with ozone. Intraperitoneal administration of the NRF2 inhibitor ML385, the SLC7A11 inhibitor Erastin, and the GPX4 inhibitor RSL3 was performed one hour prior to model establishment.

RESULTS

Our results showed that ozone preconditioning mitigated neuronal damage caused by cerebral I/R, reduced the severity of neurological deficits, lowered cerebral infarct volume in middle cerebral artery occlusion (MCAO) rats, and decreased the volume of cerebral infarcts. Transmission electron microscopy, immunofluorescence, and Western blotting indicated ferroptosis following MCAO-induced brain damage. MCAO resulted in morphological damage to neuronal mitochondria, increased lipid peroxidation accumulation, and elevated malondialdehyde (MDA) production. Furthermore, MCAO decreased levels of FTH1 and GPX4 (negative regulators of ferroptosis) and increased ACSL4 levels (a positive regulator of ferroptosis). Ozone preconditioning demonstrated a neuroprotective effect by increasing NRF2 nuclear translocation and the expression of SLC7A11 and GPX4. Treatment with ML385, Erastin, and RSL3 significantly reversed ozone preconditioning's protective effect on neuronal ferroptosis.

CONCLUSION

Our findings demonstrated that ozone treatment attenuates ferroptosis in a cerebral ischemia/reperfusion injury rat model via the NRF2/SLC7A11/GPX4 pathway, providing a theoretical basis for ozone's potential use as a therapy to prevent ischemic stroke.

The role of ferroptosis in cardio-oncology

With the rapid development of new generations of antitumor therapies, the average survival time of cancer patients is expected to be continuously prolonged. However, these therapies often lead to cardiotoxicity, resulting in a growing number of tumor survivors with cardiovascular disease. Therefore, a new interdisciplinary subspecialty called "cardio-oncology" has emerged, aiming to detect and treat cardiovascular diseases associated with tumors and antitumor therapies. Recent studies have highlighted the role of ferroptosis in both cardiovascular and neoplastic diseases. The balance between intracellular oxidative stress and antioxidant defense is crucial in regulating ferroptosis. Tumor cells can evade ferroptosis by upregulating multiple antioxidant defense pathways, while many antitumor therapies rely on downregulating antioxidant defense and promoting ferroptosis in cancer cells. Unfortunately, these ferroptosis-inducing antitumor therapies often lack tissue specificity and can also cause injury to the heart, resulting in ferroptosis-induced cardiotoxicity. A range of cardioprotective agents exert cardioprotective effects by inhibiting ferroptosis. However, these cardioprotective agents might diminish the efficacy of antitumor treatment due to their antiferroptotic effects. Most current research on ferroptosis only focuses on either tumor treatment or heart protection but rarely considers both in concert. Therefore, further research is needed to study how to protect the heart during antitumor therapies by regulating ferroptosis. In this review, we summarized the role of ferroptosis in the treatment of neoplastic diseases and cardiovascular diseases and also attempted to propose further research directions for ferroptosis in the field of cardio-oncology.

The protective effect of Enteromorpha prolifera polysaccharide on alcoholic liver injury in C57BL/6 mice

An alcohol-induced liver injury model was induced in C57BL/6 mice to assess the protective efficacy of Enteromorpha prolifera polysaccharides (EP) against liver damage. Histological alterations in the liver were examined following hematoxylin-eosin (H&E) staining. Biochemical assay kits and ELISA kits were employed to analyze serum and liver biochemical parameters, as well as the activity of antioxidant enzymes and alcohol metabolism-related enzymes. The presence of oxidative stress-related proteins in the liver was detected using western blotting. Liquid chromatography and mass spectrometry were used to profile serum metabolites in mice. The findings demonstrated that EP-H (100 mg/Kg) reduced serum ALT and AST activity by 2.31-fold and 2.32-fold, respectively, when compared to the alcohol-induced liver injury group. H&E staining revealed a significant attenuation of microvesicular steatosis and ballooning pathology in the EP-H group compared to the model group. EP administration was found to enhance alcohol metabolism by regulating metabolite-related enzymes (ADH and ALDH) and decreasing CYP2E1 expression. EP also modulated the Nrf2/HO-1 signaling pathway to bolster hepatic antioxidant capacity. Furthermore, EP restored the levels of lipid metabolites (Glycine, Butanoyl-CoA, and Acetyl-CoA) to normalcy. In summary, EP confers protection to the liver through the regulation of antioxidant activity and lipid metabolites in the murine liver.

Construction of an oxidative stress-associated genes signature in breast cancer by machine learning algorithms

OBJECTIVE

To construct a prognostic model of a breast cancer-related oxidative stress-related gene (OSRG) signature using machine learning algorithms.

METHODS

The OSRGs of breast cancer were constructed by least absolute shrinkage and selection operator (LASSO) and multivariate Cox regression analysis. The Cancer Genome Atlas (TCGA) was used to analyse the gene expression and prognostic value. The Human Protein Atlas was used to analyse the protein expression of hub genes. Receiver operating characteristic analysis, calibration curve and decision curve analysis were used to predict the stability of this model.

RESULTS

The area under the curve of 1-, 3- and 5-year overall survival were 0.751, 0.707 and 0.645 in the TCGA training dataset; and 0.692, 0.678 and 0.602 in the TCGA testing dataset, respectively. Calibration plot showed good agreement between predicted probabilities and observed outcomes. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Set Enrichment Analysis (GSEA) pathway analysis indicated that multiple cancer-related pathways were highly enriched in the high-risk group. Immune infiltration analysis showed immune cells and their functions may play a key role in the development and mechanism of breast cancer.

CONCLUSIONS

This new OSRG signature was associated with the immune infiltration and it might be useful in predicting the prognosis in patients with breast cancer.