MCL attenuates atherosclerosis by suppressing macrophage ferroptosis via targeting KEAP1/NRF2 interaction

Natural products and ferroptosis: A novel approach for heart failure management

BACKGROUND

The discovery of ferroptosis has brought a revolutionary breakthrough in heart failure treatment, and natural products, as a significant source of drug discovery, are gradually demonstrating their extraordinary potential in regulating ferroptosis and alleviating heart failure symptoms. In addition to chemically synthesized small molecule compounds, natural products have attracted attention as an important source for discovering compounds that target ferroptosis in treating heart failure.

PURPOSE

Systematically summarize and analyze the research progress on improving heart failure through natural products' modulation of the ferroptosis pathway.

METHODS

By comprehensively searching authoritative databases like PubMed, Web of Science, and China National Knowledge Infrastructure with keywords such as "heart failure", "cardiovascular disease", "heart disease", "ferroptosis", "natural products", "active compounds", "traditional Chinese medicine formulas", "traditional Chinese medicine", and "acupuncture", we aim to systematically review the mechanism of ferroptosis and its link with heart failure. We also want to explore natural small-molecule compounds, traditional Chinese medicine formulas, and acupuncture therapies that can inhibit ferroptosis to improve heart failure.

RESULTS

In this review, we not only trace the evolution of the concept of ferroptosis and clearly distinguish it from other forms of cell death but also establish a comprehensive theoretical framework encompassing core mechanisms such as iron overload and system xc-/GSH/GPX4 imbalance, along with multiple auxiliary pathways. On this basis, we innovatively link ferroptosis with various types of heart failure, covering classic heart failure types and extending our research to pre-heart failure conditions such as arrhythmia and aortic aneurysm, providing new insights for early intervention in heart failure. Importantly, this article systematically integrates multiple strategies of natural products for interfering with ferroptosis, ranging from monomeric compounds and bioactive components to crude extracts and further to traditional Chinese medicine formulae. In addition, non-pharmacological means such as acupuncture are also included.

CONCLUSION

This study fills the gap in the systematic description of the relationship between ferroptosis and heart failure and the therapeutic strategies of natural products, aiming to provide patients with more diverse treatment options and promote the development of the heart failure treatment field.

The molecular mechanism by which CTSB degrades FPN to disrupt macrophage iron homeostasis and promote the progression of atherosclerosis

The incidence of atherosclerosis (AS) remains high, and iron-dependent cell death (termed ferroptosis) is thought to play a key role in the progression of AS. Studies have shown that cathepsin B (CTSB) is an important regulatory molecule in atherosclerosis. However, how CTSB regulates AS progression has not been reported, and whether it is related to ferroptosis is poorly studied. In the present study, we observed a significant upregulation of CTSB expression in two AS models, ApoE knockout mice and SD rats given a HFD. According to our findings, CTSB can promote development of the AS plaque region, while inhibition of CTSB showed a reduction of AS lesion area and lipid deposition. Single-cell transcriptome analysis of AS tissue from humans revealed that CTSB is primarily expressed in macrophages. Oxidized low-density lipoprotein (ox-LDL) significantly enhanced macrophage CTSB expression, and induced ferroptosis in vitro. Mechanistically, Ferroportin (FPN) is the binding target of CTSB. CTSB can negatively regulate the protein level of FPN and promote its degradation, which further leads to ferroptosis of macrophages. We confirmed that ferroptosis in macrophages could be effectively inhibited by knockdown or pharmacological inhibition of CTSB, which in turn slowed the progression of AS. In conclusion, our study suggests that CTSB disrupts iron homeostasis in macrophages by degrading FPN and induces ferroptosis, thereby exacerbating the development of AS. Targeting CTSB may become an important potential strategy for the treatment of AS.

Dual-Functional Antioxidant CIRAKLC Peptide Discovery: A Biomaterial-Integrated Strategy for ROS Scavenging and Enzyme Modulation in Oxidative Stress Therapeutics

Antioxidants play a pivotal role in activating endogenous defense mechanisms, neutralizing free radicals, and mitigating oxidative stress. In this study, an antioxidant peptide library was constructed based on amino acid structure-activity relationships, focusing on ROS scavenging and enzymatic modulation. Through comprehensive chemical and biological evaluations, we identified the peptide CIRAKLC (designated as CL7), which exhibited exceptional ROS-scavenging capacity and enzyme-modulating activity, demonstrating superior in vitro antioxidant efficacy. CL7 exhibited excellent biocompatibility and effectively protected HepG2 cells from H2O2-induced ROS-mediated oxidative damage through both preventive and reparative mechanisms. Furthermore, CL7 modulated key enzymes (CAT, MDA, SOD, ALT, and AST), displaying hepatoprotective, anti-inflammatory, and antiaging effects, along with significant photoprotective efficacy. Molecular docking revealed key hydrogen bonding and electrostatic interactions when the peptide binds to redox-related receptors (Nrf2/Keap1 and IKK-β). These findings underscore CL7's robust antioxidant capacity and multifunctionality, highlighting its broad therapeutic potential in oxidative stress management.

Kumquat Flavonoids Attenuate Atherosclerosis in ApoE-/- Mice by Inhibiting the Activation of NLRP3 Inflammasome through Upregulating MicroRNA-145

Atherosclerosis (AS) is widely recognized as a consequence of chronic inflammation, with the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome playing a pivotal role in mediating this inflammatory response. Kumquat flavonoids (KFs), the primary active ingredients in kumquat, have demonstrated potential in modulating inflammation and may help prevent AS. Herein, this study aimed to explore the protective effects and underlying mechanisms of KFs on AS using an ApoE-/- mouse model fed a high-fat/cholesterol diet (HFCD) and the mouse aortic vascular smooth muscle cell (MOVAS) inflammation model induced by oxidized low-density lipoprotein (ox-LDL). Our results show that KFs significantly reduced serum lipid levels and suppressed the overproduction of inflammatory cytokines in ApoE-/- mice. Notably, KFs also decreased the area of atherosclerotic lesions and plaque formation in the aorta of ApoE-/- mice. Additionally, in vivo (mouse aortic tissue) and in vitro (MOVAS cells), KFs were found to inhibit the activation of NLRP3 inflammasome and simultaneously upregulate microRNA-145 (miR-145). In conclusion, our findings suggest that KFs exert their inhibitory effects on NLRP3 inflammasome through upregulating miR-145, thereby alleviating the progression of AS.

Virtual Screening of Kelch-like ECH-Associated Protein 1-Nuclear Factor Erythroid 2-Related Factor 2 (Keap1-Nrf2) Inhibitors and In Vitro Validation

The transcription factor erythroid 2-related factor 2 (Nrf2) is a central regulator of cellular defense mechanisms against oxidative stress and inflammation. Keap1 (Kelch-like ECH-associated protein 1) regulates Nrf2 activity by ubiquitination-mediated cytoplasmic retention, thereby suppressing its nuclear translocation and subsequent transcriptional activation of genes encoding phase II detoxifying enzymes. Using a structure-based virtual screening approach, we screened ~16,000 natural compounds to identify Keap1-Nrf2 PPI inhibitors. Nine compounds were identified based on their high binding affinities and favorable interactions with Keap1, primarily through non-covalent interactions. To validate the binding stability of these inhibitors, molecular dynamics (MD) simulations were performed, confirming the robustness of the Keap1-inhibitor complexes over time. Subsequent in vitro assays on human epithelial keratinocyte cells (HaCaT) revealed that six of these compounds notably upregulated Nrf2 mRNA expression, regis tering increases from 23% to 50% in comparison to the control. Notably, chebulinic acid emerged as the most potent compound, demonstrating the greatest elevation in Nrf2 expression. Penetration studies further showed that chebulinic acid, when encapsulated in silk fibroin, achieved a 0.14% penetration rate after 24 h though it could not penetrate into the stratum corneum alone. This result highlighted the potential of chebulinic acid in the use of anti-aging skincare formulations. Collectively, our findings affirmed that molecular docking is a reliable and effective approach for the identification of novel anti-aging agents targeting the Keap1-Nrf2 pathway.

Growth Arrest-specific 1 Inhibits Keap1/Nrf2 Signaling Transduction in the Activation of the Ferroptosis Program in Retinal Müller Cells

BACKGROUND

Diabetes retinopathy (DR) represents a microvascular disease in diabetes. Growth arrest-specific 1 (GAS1) is differentially expressed in rat retinal Müller cells under high glucose (HG) conditions, and its promotion of ferroptosis contributes to retinal cell death. However, the influence of GAS1 in DR is elusive. Herein, we aimed to investigate the effect and potential mechanism based on GAS1-mediated ferroptosis on DR.

METHODS

After HG treatment, the differentially expressed genes in rat retinal Müller cells were analyzed by transcriptome sequencing followed by Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses; finally, GAS1 was selected. The effects of GAS1 knockdown/overexpression and nuclear factor erythroid 2-related factor (Nrf2) silencing on viability, apoptosis, lipid peroxidation, Fe2+, and oxidative stress levels in HG-induced/transfected Müller cells were measured by Cell Counting Kit-8 (CCK-8) assay, flow cytometry, and commercial reagent kits. The potential effects of GAS1 and Nrf2, especially on GAS1, Nrf2, and Kelch-like ECH-associated protein 1 (Keap1) expressions in cells, were determined by quantitative real-time polymerase chain reaction (qRT-PCR) or Western blot.

RESULTS

HG treatment decreased cell viability and glutathione (GSH) levels and increased apoptosis, lipid reactive oxygen species (ROS), glutathione disulfide (GSSG), malondialdehyde (MDA), oxidative stress, and Fe2+ levels in Müller cells (p < 0.01). HG treatment also upregulated GAS1, Keap1, and total Nrf2 expressions while downregulating nuclear Nrf2 in Müller cells (p < 0.001). GAS1 downregulation enhanced cell viability, GSH levels, and nuclear Nrf2 expression while reducing the levels of apoptosis, lipid ROS, GSSG, MDA, Fe2+, Keap1, and total Nrf2 in HG-treated Müller cells (p < 0.001), whereas GAS1 overexpression had the opposite effects. Additionally, Nrf2 silencing reversed the impact of GAS1 overexpression in HG-treated Müller cells (p < 0.05).

CONCLUSION

GAS1 inhibits Keap1/Nrf2 signaling transduction in activating ferroptosis in retinal Müller cells; thus, this study can aid in setting the stage for novel treatment methods against DR.

Thirty years of NRF2: advances and therapeutic challenges

Over the last 30 years, NRF2 has evolved from being recognized as a transcription factor primarily involved in redox balance and detoxification to a well-appreciated master regulator of cellular proteostasis, metabolism and iron homeostasis. NRF2 plays a pivotal role in diverse pathologies, including cancer, and metabolic, inflammatory and neurodegenerative disorders. It exhibits a Janus-faced duality, safeguarding cellular integrity in normal cells against environmental insults to prevent disease onset, whereas in certain cancers, constitutively elevated NRF2 levels provide a tumour survival advantage, promoting progression, therapy resistance and metastasis. Advances in understanding the mechanistic regulation of NRF2 and its roles in human pathology have propelled the investigation of NRF2-targeted therapeutic strategies. This Review dissects the mechanistic intricacies of NRF2 signalling, its cross-talk with biological processes and its far-reaching implications for health and disease, highlighting key discoveries that have shaped innovative therapeutic approaches targeting NRF2.

Spermine delivered by ZIF90 nanoparticles alleviates atherosclerosis by targeted inhibition of macrophage ferroptosis in plaque

BACKGROUND

Nowadays, emerging evidence have suggested that the ferroptosis of macrophages could contribute to the progression of atherosclerosis (AS). Meanwhile, Spermine (Sp) could serve as an endogenous small molecule exhibiting a wide range of cardiovascular protective effects.

METHODS

Zeolitic imidazolate framework-90 (ZIF90) nanoparticles were synthesized and utilized to create a novel delivery nanosystem encapsulated with Sp (CD16/32-ZIF90@Sp). The efficacy of CD16/32-ZIF90@Sp in protecting against AS and ferroptosis was evaluated in ApoE-/- mice and macrophages, with a focus on assessing potential adverse effects in vivo.

RESULTS

CD16/32-ZIF90@Sp exhibited reliable and stable delivery of Sp within acidic environments and ATP sensitivity. CD16/32-ZIF90@Sp effectively reduced the cytotoxicity of Sp. As is evidenced by in vitro and vivo experiments, CD16/32-ZIF90@Sp showed precise targeting of macrophages within atherosclerotic plaques and ox-LDL-activated macrophages. Furthermore, treatment with CD16/32-ZIF90@Sp effectively attenuated the progression of AS and the ferroptosis of macrophage within plaque in ApoE-/- mice without causing significant side effects. Mechanistically, we found that CD16/32-ZIF90@Sp inhibited ferroptosis via improving mitochondrial function and upregulating the expression level of GPX4/xCT.

CONCLUSION

Our study demonstrated that CD16/32-modified ZIF90 nanoparticles could effectively target macrophages within atherosclerotic plaques, leading to the inhibition of atherosclerotic plaque progression in ApoE-/- mice. These effects were attributed to the enhancement of mitochondrial function and the inhibition of macrophage ferroptosis, with limited side effects.

Ferroptosis in senescence and age-related diseases: pathogenic mechanisms and potential intervention targets

As the global population continues to age, the prevalence of age-related diseases is increasing, significantly influencing social and economic development, the stability of social security systems, and progress in medical technology. Ferroptosis, a recently discovered form of programmed cell death driven by iron-dependent lipid peroxidation, has emerged as a key area of research. Studies have revealed a strong association between ferroptosis and senescence. In this article, we systematically summarize the molecular mechanisms and associated signaling pathways underlying ferroptosis, emphasizing its pivotal role in the onset and progression of age-related diseases. By providing new perspectives, we aim to advance understanding of the pathogenesis of age-related diseases and guide the development of effective intervention strategies.

Micheliolide attenuates sepsis-induced acute lung injury by suppressing mitochondrial oxidative stress and PFKFB3-driven glycolysis

BACKGROUND

Sepsis is a potentially fatal condition with a significant risk of death. Acute lung injury (ALI) is a life-threatening complication of sepsis, and the inflammatory response plays a critical role in sepsis-induced ALI. The protective effects of micheliolide (MCL) against renal fibrosis and leukemia have been demonstrated, but the precise underlying mechanisms remain unclear.

METHODS

In vitro, lipopolysaccharides (LPS) and interferon-gamma (IFN-γ) were used to stimulate RAW264.7 cells and bone marrow-derived macrophages (BMDMs) to investigate the protective effect of MCL on sepsis-induced ALI. Cecal ligation and puncture (CLP) models were constructed in mice to induce ALI in vivo. The expression of inflammatory factors, macrophage polarization markers, and the glycolysis-related enzyme 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) were measured in vivo. Mitochondrial function, oxidative stress, and mitochondrial-related proteins were evaluated in vitro.

RESULTS

MCL inhibited CLP-induced ALI, as evidenced by improvements in proinflammatory factor levels, lung wet/dry ratios, and histopathological findings. In vitro, MCL treatment significantly suppressed LPS + IFN-γ-induced M1-type polarization of RAW264.7 cells and BMDMs, as well as the production of inflammatory factors and oxidative stress. Mechanistic experiments revealed that MCL suppresses PFKFB3-driven glycolysis to reduce inflammation and activates the mitochondrial unfolded protein response (UPRmt) to alleviate mitochondrial stress. However, the therapeutic effect of MCL was diminished when PFKFB3 was overexpressed in cells.

CONCLUSION

This study is the first to demonstrate that MCL attenuates sepsis-induced ALI by reducing M1-type macrophage polarization. Its therapeutic effect is closely related to the suppression of oxidative stress and PFKFB3-driven glycolysis.

Mechanisms and Therapeutic Potential of GPX4 in Pain Modulation

Pain, a complex symptom encompassing both sensory and emotional dimensions, constitutes a significant global public health issue. Oxidative stress is a pivotal factor in the complex pathophysiology of pain, with glutathione peroxidase 4 (GPX4) recognized as a crucial antioxidant enzyme involved in both antioxidant defense mechanisms and ferroptosis pathways. This review systematically explores GPX4's functions across various pain models, including neuropathic, inflammatory, low back, and cancer-related pain. Specifically, the focus includes GPX4's physiological roles, antioxidant defense mechanisms, regulation of ferroptosis, involvement in signal transduction pathways, and metabolic regulation. By summarizing current research, we highlight the potential of GPX4-targeted therapies in pain management.

The IDH1-R132H mutation aggravates cisplatin-induced acute kidney injury by promoting ferroptosis through disrupting NDUFA1 and FSP1 interaction

The IDH1-R132H mutation is implicated in the development of various tumors. Whether cisplatin, a common chemotherapeutic agent, induces more significant renal toxicity in individuals with the IDH1-R132H mutation remains unclear. In this study, we observed that the IDH1-R132H mutation exacerbates mitochondrial lipid peroxidation and dysfunction in renal tubules, rendering the kidneys more susceptible to cisplatin-induced ferroptosis. The IDH1-R132H mutation increases methylation of the Ndufa1 promoter, thereby suppressing NDUFA1 transcription and translation. This suppression disrupts NDUFA1's interaction with FSP1, reducing its resistance to cisplatin-induced tubular epithelial cell death. As a consequence, ROS accumulates, lipid peroxidation occurs, and ferroptosis is triggered, thereby promoting acute kidney injury. In summary, this study elucidates a novel mechanism underlying cisplatin-induced nephrotoxicity and provides valuable insights for the development of personalized treatment strategies for tumor patients carrying the IDH1-R132H mutation.

N -Acetyl-Tryptophan in Acute Kidney Injury after Cardiac Surgery

Key Points

Background

Cardiac surgery–associated AKI is a common serious complication after cardiac surgery. Currently, there are no specific pharmacological therapies. Our understanding of its pathophysiology remains preliminary.

Methods

A total of 2504 patients with and without AKI after cardiac surgery were enrolled. High-performance liquid chromatography coupled with mass spectrometry was used for untargeted analysis of metabolites in plasma, identifying significant differential metabolites. Subsequently, a liquid chromatography–tandem mass spectrometry–based approach using isotope-labeled standard addition was performed for targeted analysis of the metabolic marker N-acetyl-tryptophan (NAT). The function of NAT was determined using different kidney injury mouse models and epithelial cellular models. Transcriptome sequencing, surface plasmon resonance, and protein mutation were used to explore the mechanism of NAT on the kidney.

Results

We identified a total of 32 differential metabolites related to AKI occurrence on the basis of a cohort of 1042 patients. Among them, NAT was elevated in plasma of patients with cardiac surgery–associated AKI compared with those who did not develop AKI after cardiac surgery. The higher level of NAT in plasma was confirmed by accurate targeted quantification. NAT exhibited kidney-protective effects in ischemia-reperfusion–, cisplatin-, and unilateral ureteral obstruction–induced kidney injury mouse models. Mechanistically, NAT exerted kidney-protective effects by interacting with Kelch-like ECH-associated protein 1 at 483 and 508 sites, resulting in Nrf2 nuclear translocation and the transcription of proteasome genes, respectively.

Conclusions

NAT plays a key role in kidney protection.

Identification of ferroptosis-related LncRNAs as potential targets for improving immunotherapy in glioblastoma

The effect of ferroptosis-related long non-coding RNAs (lncRNAs) in predicting immunotherapy response to glioblastoma (GBM) remains obscure. This study established a 11-lncRNAs prognostic signature. Differential gene expression analysis, univariate and multivariate Cox regression analyses and the least absolute shrinkage and selection operator (LASSO) regression algorithm were used to identify prognostic ferroptosis-related genes and establish a nomogram model of risk score. Kaplan-Meier survival plots and receiver operating characteristic (ROC) curve analysis were used to evaluate the prognostic accuracy of the model in the TCGA-GBM cohort. To verify the expression of these signatures, we analyzed the expression levels of three lncRNAs (AGAP2-AS1, OSMR-AS1, UNC5B-AS1) in LN229 and U87 cells. The ROC analysis showed that the area under curve (AUC) of this signature is 0.814, suggesting that it has a promising performance on GBM prognostic prediction. Kaplan-Meier analysis showed that the survival rate of GBM patients in high-risk group was significantly lower than low-risk group, and the performance of this signature on GBM prognostic prediction was superior to conventional clinicopathological factors. Further qRT-PCR experiment also confirmed our prediction of lncRNA signatures. These ferroptosis-related lncRNAs might be therapeutic targets for glioblastoma, and targeting these lncRNAs can also improve the efficacy of immunotherapy, especially immune checkpoint inhibitors. Mechanistically, these findings might attribute to N6-methyladenosine (m6A) mRNA modification on lncRNAs.

Adverse Effects of Nrf2 in Different Organs and the Related Diseases

Significance: Under normal physiological conditions, Nrf2 undergoes ubiquitination and subsequent proteasome degradation to maintain its basal activity. Oxidative stress can trigger Nrf2 activation, prompting its translocation to the nucleus where it functions as a transcription factor, activating various antioxidant pathways, and conferring antioxidant properties. Recent Advances: While extensive research has shown Nrf2's protective role in various diseases, emerging evidence suggests that Nrf2 activation can also produce harmful effects. Critical Issues: This review examines the pathological contexts in which Nrf2 assumes different roles, emphasizing the mechanisms and conditions that result in adverse outcomes. Future Directions: Persistent Nrf2 activation may have deleterious consequences, necessitating further investigation into the specific conditions and mechanisms through which Nrf2 exerts its harmful effects. Antioxid. Redox Signal. 00, 000-000.

Mechanisms and treatment of atherosclerosis: focus on macrophages

Macrophages are the basic mediators and coordinators of various types of chronic inflammation and play a crucial role in the formation and development of atherosclerosis (AS). In the complex microenvironment of atherosclerotic plaques, macrophages of different sources are exposed to different signal stimuli and thus polarized into various subpopulations. Various types of macrophages with predominantly M1 and M2 phenotypes also play different regulatory roles in the initiation and progression of AS. Lipid-lowering drugs, mainly statins, are widely used in clinical practice, but the adverse reactions are obvious and there is a lack of personalized treatment. Emerging targeted macrophage and Traditional Chinese medicine (TCM)-related therapies can regulate the cellular microenvironment, inhibit the polarization of M1 macrophages, and promote the activation of M2 macrophages, providing new ideas for the prevention and treatment of AS.

Ginkgo Flavone Aglycone Ameliorates Atherosclerosis via Inhibiting Endothelial Pyroptosis by Activating the Nrf2 Pathway

Natural antioxidants have been shown to be effective against atherosclerosis. Ginkgo flavone aglycone (GA) has strong antioxidant properties and can protect against endothelial damage. However, the mechanisms by which GA protects against atherosclerosis remain largely unexplored. This study hopes to find the anti-atherosclerotic mechanism of GA. ApoE-/- mice fed a high-fat diet were used for modeling atherosclerosis. The efficacy of GA on mice with atherosclerosis was evaluated based on the following indicators: Oil Red O staining, Masson staining, lipid content, and apoptosis. Transmission electron microscopy, Western blot, immunofluorescence staining, and propidium iodide staining were used to analyze the effects of GA on ox-LDL-treated human aortic endothelial cells. GA activated Nrf2 by promoting the nuclear translocation of Nrf2, thereby inhibiting endothelial pyroptosis. GA prevented endothelial pyroptosis suppressed oxidative stress, and inhibited the development of atherosclerosis in ApoE-/- mice fed high-fat diets. At the cellular level, GA suppressed ox-LDL-induced pyroptosis of HAECs by reducing reactive oxygen species (ROS) levels and inhibiting NLRP3 inflammasome. Furthermore, siRNA targeting Nrf2 or ML385, an Nrf2 inhibitor, reversed these effects. GA liberated Nrf2 from Keap1 sequestration, enhanced the nuclear translocation of Nrf2 and the transcription of downstream antioxidant proteins, reinforced the antioxidant defense system, and inhibited oxidative stress, thereby preventing endothelial cell pyroptosis, and attenuating the progression of atherosclerosis. This study indicated that GA mitigated endothelial pyroptosis by modulating Keap1/Nrf2 interactions, shedding light on the potential mechanisms underlying the protective effects of natural antioxidants against atherosclerosis.

Nrf2-mediated ferroptosis inhibition: a novel approach for managing inflammatory diseases

Inflammatory diseases, including psoriasis, atherosclerosis, rheumatoid arthritis, and ulcerative colitis, are characterized by persistent inflammation. Moreover, the existing treatments for inflammatory diseases only provide temporary relief by controlling symptoms, and treatments of unstable and expensive. Therefore, new therapeutic solutions are urgently needed to address the underlying causes or symptoms of inflammatory diseases. Inflammation frequently coincides with a high level of (reactive oxygen species) ROS activation, serving as a fundamental element in numerous physiological and pathological phenotypes that can result in serious harm to the organism. Given its pivotal role in inflammation, oxidative stress, and ferroptosis, ROS represents a focal node for investigating the (nuclear factor E2-related factor 2) Nrf2 pathway and ferroptosis, both of which are intricately linked to ROS. Ferroptosis is mainly triggered by oxidative stress and involves iron-dependent lipid peroxidation. The transcription factor Nrf2 targets several genes within the ferroptosis pathway. Recent studies have shown that Nrf2 plays a significant role in three key ferroptosis-related routes, including the synthesis and metabolism of glutathione/glutathione peroxidase 4, iron metabolism, and lipid processes. As a result, ferroptosis-related treatments for inflammatory diseases have attracted much attention. Moreover, drugs targeting Nrf2 can be used to manage inflammatory conditions. This review aimed to assess ferroptosis regulation mechanism and the role of Nrf2 in ferroptosis inhibition. Therefore, this review article may provide the basis for more research regarding the treatment of inflammatory diseases through Nrf2-inhibited ferroptosis.

Targeting Nrf2 signaling pathway: new therapeutic strategy for cardiovascular diseases

Cardiovascular diseases (CVDs) are the leading cause of death globally, with oxidative stress (OS) identified as a primary contributor to their onset and progression. Given the elevated incidence and mortality rates associated with CVDs, there is an imperative need to investigate novel therapeutic strategies. Nuclear factor erythroid 2-related factor 2 (Nrf2), ubiquitously expressed in the cardiovascular system, has emerged as a promising therapeutic target for CVDs due to its role in regulating OS and inflammation. This review aims to delve into the mechanisms and actions of the Nrf2 pathway, highlighting its potential in mitigating the pathogenesis of CVDs.

Macrophages in cardiovascular diseases: molecular mechanisms and therapeutic targets

The immune response holds a pivotal role in cardiovascular disease development. As multifunctional cells of the innate immune system, macrophages play an essential role in initial inflammatory response that occurs following cardiovascular injury, thereby inducing subsequent damage while also facilitating recovery. Meanwhile, the diverse phenotypes and phenotypic alterations of macrophages strongly associate with distinct types and severity of cardiovascular diseases, including coronary heart disease, valvular disease, myocarditis, cardiomyopathy, heart failure, atherosclerosis and aneurysm, which underscores the importance of investigating macrophage regulatory mechanisms within the context of specific diseases. Besides, recent strides in single-cell sequencing technologies have revealed macrophage heterogeneity, cell-cell interactions, and downstream mechanisms of therapeutic targets at a higher resolution, which brings new perspectives into macrophage-mediated mechanisms and potential therapeutic targets in cardiovascular diseases. Remarkably, myocardial fibrosis, a prevalent characteristic in most cardiac diseases, remains a formidable clinical challenge, necessitating a profound investigation into the impact of macrophages on myocardial fibrosis within the context of cardiac diseases. In this review, we systematically summarize the diverse phenotypic and functional plasticity of macrophages in regulatory mechanisms of cardiovascular diseases and unprecedented insights introduced by single-cell sequencing technologies, with a focus on different causes and characteristics of diseases, especially the relationship between inflammation and fibrosis in cardiac diseases (myocardial infarction, pressure overload, myocarditis, dilated cardiomyopathy, diabetic cardiomyopathy and cardiac aging) and the relationship between inflammation and vascular injury in vascular diseases (atherosclerosis and aneurysm). Finally, we also highlight the preclinical/clinical macrophage targeting strategies and translational implications.

Melatonin suppresses atherosclerosis by ferroptosis inhibition via activating NRF2 pathway

Melatonin (MLT), a conserved small indole compound, exhibits anti-inflammatory and antioxidant properties, contributing to its cardioprotective effects. Lipoprotein-associated phospholipase A2 (Lp-PLA2) is associated with atherosclerosis disease risk, and is known as an atherosclerosis risk biomarker. This study aimed to investigate the impact of MLT on Lp-PLA2 expression in the atherosclerotic process and explore the underlying mechanisms involved. In vivo, ApoE-/- mice were fed a high-fat diet, with or without MLT administration, after which the plaque area and collagen content were assessed. Macrophages were pretreated with MLT combined with ox-LDL, and the levels of ferroptosis-related proteins, NRF2 activation, mitochondrial function, and oxidative stress were measured. MLT administration significantly attenuated atherosclerotic plaque progression, as evidenced by decreased plaque area and increased collagen. Compared with those in the high-fat diet (HD) group, the levels of glutathione peroxidase 4 (GPX4) and SLC7A11 (xCT, a cystine/glutamate transporter) in atherosclerotic root macrophages were significantly increased in the MLT group. In vitro, MLT activated the nuclear factor-E2-related Factor 2 (NRF2)/SLC7A11/GPX4 signaling pathway, enhancing antioxidant capacity while reducing lipid peroxidation and suppressing Lp-PLA2 expression in macrophages. Moreover, MLT reversed ox-LDL-induced ferroptosis, through the use of ferrostatin-1 (a ferroptosis inhibitor) and/or erastin (a ferroptosis activator). Furthermore, the protective effects of MLT on Lp-PLA2 expression, antioxidant capacity, lipid peroxidation, and ferroptosis were decreased in ML385 (a specific NRF2 inhibitor)-treated macrophages and in AAV-sh-NRF2 treated ApoE-/- mice. MLT suppresses Lp-PLA2 expression and atherosclerosis processes by inhibiting macrophage ferroptosis and partially activating the NRF2 pathway.

Ferroptosis: a potential target for the treatment of atherosclerosis

Atherosclerosis (AS), the main contributor to acute cardiovascular events, such as myocardial infarction and ischemic stroke, is characterized by necrotic core formation and plaque instability induced by cell death. The mechanisms of cell death in AS have recently been identified and elucidated. Ferroptosis, a novel iron-dependent form of cell death, has been proven to participate in atherosclerotic progression by increasing endothelial reactive oxygen species (ROS) levels and lipid peroxidation. Furthermore, accumulated intracellular iron activates various signaling pathways or risk factors for AS, such as abnormal lipid metabolism, oxidative stress, and inflammation, which can eventually lead to the disordered function of macrophages, vascular smooth muscle cells, and vascular endothelial cells. However, the molecular pathways through which ferroptosis affects AS development and progression are not entirely understood. This review systematically summarizes the interactions between AS and ferroptosis and provides a feasible approach for inhibiting AS progression from the perspective of ferroptosis.