Hesperidin mitigates oxidative stress-induced ferroptosis in nucleus pulposus cells via Nrf2/NF-κB axis to protect intervertebral disc from degeneration

Therapeutic potential of Da Cheng Qi Decoction and its ingredients in regulating ferroptosis via the NOX2-GPX4 signaling pathway to alleviate and predict severe acute pancreatitis

OBJECTIVE

This study aimed to elucidate the protective effects of Da Cheng Qi Decoction (DCQD) on severe acute pancreatitis (SAP) by targeting ferroptosis in pancreatic acinar cells and to establish a predictive signature and nomogram for acute pancreatitis (AP) risk assessment.

METHODS

We utilized microarray analysis to delineate gene expression patterns among 32 healthy controls and 87 AP patients stratified by severity. Employing SAP models and NOX2-deficient cells, we investigated the molecular underpinnings of ferroptosis. The impact of DCQD and the ferroptosis inhibitor Fer-1 on gene expression, oxidative stress, and inflammation was assessed. Machine learning algorithms identified differentially expressed genes (DEGs) sensitive to DCQD, SAP, and ferroptosis (DSNFGs), which were validated across multiple datasets. A predictive nomogram integrating DSNFGs was developed, and single-cell analysis provided a comprehensive view of the cellular dynamics.

RESULTS

The microarray analysis revealed upregulation of NOX2 and downregulation of GPX4 in AP, with expression patterns correlating with disease severity. DCQD ameliorated SAP-induced pancreatic acinar cell damage and ferroptosis by reducing inflammatory markers and enhancing GPX4 expression. NOX2 knockout mitigated ferroptosis in SAP models, suggesting a key role in the disease process. DCQD and Fer-1 differentially regulated the expression of ferroptosis-related genes, reduced reactive oxygen species (ROS) and high-mobility group box 1 (HMGB1) levels, and suppressed the inflammatory response in a SAP mouse model. The HPLC analysis of DCQD constituents indicated eight components (aloe-emodin, rhein, emodin, chrysophanol, naringin, hesperidin, magnolol, and honokiol) with the capacity to modulate ferroptosis. Venn analysis identified 48 DSNFGs, with a subset of five genes demonstrating significant predictive value. The developed nomogram, based on LASSO regression, showed high accuracy in validation cohorts. Single-cell RNA sequencing (scRNA-seq) and CellChat analysis uncovered heterogeneity and cell-cell communication networks in the pancreas during recovery from pancreatitis, implicating several signaling pathways.

CONCLUSION

DCQD and its eight ingredients exert its protective effect in SAP by inhibiting ferroptosis through the NOX2/GPX4 pathway. The DCQD-SAP-ferroptosis-related signature and nomogram offer a novel tool for AP risk assessment, prognosis prediction, and personalized therapeutic strategies in SAP management.

Role of oxidative stress in intervertebral disc degeneration: mechanisms, pathogenesis, and therapeutic strategies

Intervertebral disc degeneration (IDD) is a prevalent and debilitating spinal condition, characterised by the progressive degradation of disc structure and function, often accompanied by pain. Despite our increasing understanding of IDD, the precise mechanisms underlying its development and potential therapeutic targets remain incompletely understood. Recent research has highlighted that oxidative stress, along with immune abnormalities, mechanical loading imbalances, and metabolic disruptions, play a pivotal role in IDD initiation and progression. Oxidative stress in IDD results from an overproduction of reactive oxygen species (ROS) and a compromised ability to eliminate them, disrupting the redox homeostasis within the intervertebral disc. This disturbance in redox balance leads to extracellular matrix degradation (ECM), induces cellular apoptosis, and worsens the damage to disc tissues. This review provides a comprehensive overview of the pathophysiological processes of IDD, with a particular focus on the role of oxidative stress. Additionally, we explore current advancements in therapeutic strategies targeting oxidative stress, including antioxidant drugs, biomaterials, and stem cell-based approaches, offering promising avenues for the management and treatment of IDD.

Oxidized low-density lipoprotein induced ferroptosis in nucleus pulposus cell contributes to intervertebral disc degeneration via LOX-1/NF-κB/NOX signal

Oxidized low-density lipoprotein (oxLDL) activates the NF-κB signaling pathway through LOX-1, contributing to intervertebral disc degeneration (IVDD). Ferroptosis, a lipid peroxidation-driven cell death, is implicated in IVDD. This study investigates the role of ferroptosis in oxLDL-induced IVDD. Nucleus pulposus cells (NPCs) were treated with oxLDL, and ferroptosis and NF-κB p65 nuclear translocation were assessed. Bioinformatics analysis, silencing experiments, and inhibitors were used to validate the findings. In oxLDL-treated NPCs, LOX-1 and ferroptosis markers (MDA, Fe2+, lipid ROS) increased, while GSH decreased. These effects were mitigated by Liproxstatin-1 or shLOX-1. NF-κB p65 bound to LOX-1 and NOX1 promoters, forming a positive feedback loop. VAS2870 and Schisantherin A improved NPC viability and reduced ferroptosis. A mouse model showed worsening IVDD and ferroptosis over time. Clinical tissues revealed a strong correlation between LOX-1 and ferroptosis markers. oxLDL induces ferroptosis in NPCs via the LOX-1/NF-κB/NOX loop, advancing IVDD. Disrupting this loop in mice mitigated IVDD, highlighting the therapeutic potential of targeting this pathway.

Natural flavonoids from herbs and nutraceuticals as ferroptosis inhibitors in central nervous system diseases: current preclinical evidence and future perspectives

Flavonoids are a class of important polyphenolic compounds, renowned for their antioxidant properties. However, recent studies have uncovered an additional function of these natural flavonoids: their ability to inhibit ferroptosis. Ferroptosis is a key mechanism driving cell death in central nervous system (CNS) diseases, including both acute injuries and chronic neurodegenerative disorders, characterized by iron overload-induced lipid peroxidation and dysfunction of the antioxidant defense system. This review discusses the therapeutic potential of natural flavonoids from herbs and nutraceuticals as ferroptosis inhibitors in CNS diseases, focusing on their molecular mechanisms, summarizing findings from preclinical animal models, and providing insights for clinical translation. We specifically highlight natural flavonoids such as Baicalin, Baicalein, Chrysin, Vitexin, Galangin, Quercetin, Isoquercetin, Eriodictyol, Proanthocyanidin, (-)-epigallocatechin-3-gallate, Dihydromyricetin, Soybean Isoflavones, Calycosin, Icariside II, and Safflower Yellow, which have shown promising results in animal models of acute CNS injuries, including ischemic stroke, cerebral ischemia-reperfusion injury, intracerebral hemorrhage, subarachnoid hemorrhage, traumatic brain injury, and spinal cord injury. Among these, Baicalin and its precursor Baicalein stand out due to extensive research and favorable outcomes in acute injury models. Mechanistically, these flavonoids not only regulate the Nrf2/ARE pathway and activate GPX4/GSH-related antioxidant pathways but also modulate iron metabolism proteins, thereby alleviating iron overload and inhibiting ferroptosis. While flavonoids show promise as ferroptosis inhibitors for CNS diseases, especially in acute injury settings, further studies are needed to evaluate their efficacy, safety, pharmacokinetics, and blood-brain barrier penetration for clinical application.

Ferroptosis: A New Direction in the Treatment of Intervertebral Disc Degeneration

Intervertebral disc degeneration (IVDD) is one of the most common musculoskeletal disorders in middle-aged and elderly people, and lower back pain (LBP) is the main clinical symptom [1, 2], which often causes significant pain and great economic burden to patients [3]. The current molecular mechanisms of IVDD include extracellular matrix degradation, cellular pyroptosis, apoptosis, necrotic apoptosis, senescence, and the newly discovered ferroptosis [4, 5], among which ferroptosis, as a new hot spot of research, has a non-negligible role in IVDD. Ferroptosis is an iron-dependent cell death caused by lipid peroxide accumulation [6]. Its main mechanism is cell death caused by lipid peroxidation by oxygen radicals due to iron overload and inhibition of pathways such as SLC7A11-GSH-GPX4. Currently, more and more studies have found a close relationship between IVDD and ferroptosis [7]. In the process of ferroptosis, the most important factors are abnormal iron metabolism, increased ROS, lipid peroxidation, and abnormal proteins such as GSH, GPX4, and system XC-. Our group has previously elucidated the pathogenesis of IVDD in terms of extracellular matrix degradation, myeloid cell senescence and pyroptosis, apoptosis, and inflammatory immunity. Therefore, this time, we will use ferroptosis as an entry point to discover the new mechanism of IVDD and provide guidance for clinical treatment.

Bee Pollen Potential to Modulate Ferroptosis: Phytochemical Insights for Age-Related Diseases

Bee pollen (BP) is one of the richest known natural resources of micronutrients and bioactive phytochemicals. Some captivating bioactivities of BP compounds, although being largely investigated for the latter as individual molecules, remain very scarcely investigated or completely uninvestigated in bee pollen as a whole product. Among the most intriguing of these bioactivities, we identified ferroptosis as a major one. Ferroptosis, a recently discovered form of cell death (connecting oxidative stress and inflammation), is a complex pathophysiological process and one of the most crucial and perplexing events in current challenging human diseases such as cancer, neurodegeneration, and general aging diseases. Many BP compounds were found to intricately modulate ferroptosis depending on the cellular context by inducing this cell death mechanism in malignant cells and preventing it in non-malignant cells. Since research in both fields, i.e., BP and ferroptosis, is still recent, we deemed it necessary to undertake this review to figure out the extent of BP potential in modulating ferroptosis mechanisms. Our research proved that a wide range of BP compounds (polyphenols, phenolamides, carotenoids, vitamins, minerals, and others) substantially modulate diverse ferroptosis mechanisms. Accordingly, these phytochemicals and nutrients showed interesting potential in preclinical studies to lead to ferroptosis-mediated outcomes in important pathophysiological processes, including many aging-related disorders. One of the most paramount challenges that remain to be resolved is to determine how different BP compounds act on ferroptosis in different biological and pathophysiological contexts, either through synergistic or antagonistic behaviors. We hope that our current work constitutes a valuable incentive for future investigations in this promising and very relevant research avenue.

From Pathophysiology to Treatment: The Role of Ferroptosis in PCOS

Polycystic ovary syndrome (PCOS) is a prevalent gynecological endocrine and metabolic disorder in women, with an incidence rate of 10-13%. The etiology of PCOS is multifaceted, involving genetic predisposition, environmental influences, lifestyle factors, and endocrine metabolic dysregulation. Iron, a critical mineral, not only plays a role in regulating female physiological functions and the progression of PCOS but also requires careful management to avoid deficiency. However, excess iron can trigger ferroptosis, a form of nonapoptotic cell death characterized by the accumulation of lipid peroxides. While numerous studies have explored ferroptosis in patients with PCOS and animal models, the precise mechanisms and therapeutic implications remain inadequately understood. This review seeks to elucidate the pathophysiology of PCOS and the contributory factors of ferroptosis. Additionally, we examine the diverse manifestations of ferroptosis in PCOS and evaluate its role. Furthermore, we introduce ferroptosis-related traditional Chinese medicines that may enhance the understanding of PCOS pathogenesis and aid in the development of targeted therapies for ferroptosis in PCOS.

Iron chelating, antioxidant and anti-apoptotic activities of hesperidin and/or rutin against induced-ferroptosis in heart tissue of rats

Excess iron has been associated with cardiovascular diseases. Flavonoids are antioxidants and cardioprotectants. Therefore, the goal of the current study is to evaluate the anti-apoptotic, antioxidant, and iron-chelating qualities of two flavonoids, rutin (R) and hesperidin (H), as well as their potential to prevent induced ferroptosis in rats. It is an in vivo cross-sectional study, in which rats were divided into 12 groups; control, H, R, H + R, Fe, Fe + IR, Fe + IR + Ref, Fe + H, Fe + IR + H, Fe + R, Fe + IR + R and Fe + IR + H + R. Cardiac and serum iron levels, serum troponin I, creatine kinase-MB (CK-MB), total iron binding capacity (TIBC), transferrin, ferritin, and hepicidin were determined. Moreover, the levels of malondialdehyde (MDA), nitric oxide (NO) and glutathione (GSH) and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx), were also determined. The expression levels of DMT1, ACSL4, GPX4, Nrf2, and caspase-3 genes were evaluated by RT-qPCR. Lastly, a histological analysis of the heart tissues from several groups of rats was conducted. After hesperidin and/or rutin treatment, our results revealed that cardiac markers (serum troponin I and CK-MB), iron metabolism markers (serum and cardiac iron, TIBC, ferritin, transferrin, hepicidin and DMT1 expression levels) and oxidative stress markers (MDA, NO and ACSL4 expression levels) were significantly (P ⩽ 0.05) reduced, while the antioxidant markers (GSH level, GPx and SOD activities and GPX4 and Nrf2 expression levels) were significantly (P ⩽ 0.05) increased. Also, hesperidin and rutin exerted its protective anti-apoptotic role by significantly (P ⩽ 0.05) decreasing caspase-3 expression levels. Hesperidin and/or rutin treatment can be proposed as a therapeutic candidate to attenuate ferroptosis.

Humanin reduces nucleus pulposus cells ferroptosis to alleviate intervertebral disc degeneration: An in vitro and in vivo study

Background

Intervertebral disc degeneration (IDD) is a prevalent etiology of low back pain in the global adult population, leading to considerable morbidity and healthcare costs. Existing therapeutic modalities for IDD remain constrained. Ferroptosis in the nucleus pulposus (NP) cells emerges as a pivotal contributor to IDD. Humanin (HN), a mitochondrial-secreted peptide, is intricately linked to age-related maladies and showcases antioxidant, anti-inflammatory, and anti-apoptotic properties. Nonetheless, its precise involvement in IDD remains enigmatic.

Methods

The expression profile of HN in IDD was scrutinized utilizing human NP cell cultures and an IDD rat model (n = 5). The therapeutic efficacy of HN in rats was assessed via MRI and histological evaluation, alongside an exploration of the molecular underpinnings of HN's therapeutic actions in IDD management.

Results

This pioneering study unveiled a downregulation of HN expression in IDD patients, a finding corroborated through cell and rat IDD models. Furthermore, it was ascertained that exogenous HN could trigger endogenous HN expression, impede the JAK2/STAT3 and NF-κB pathways, thereby mitigating erastin-induced ferroptosis in NP cells, contingent upon the upregulation of HSP27 expression. Moreover, the study validated the role of HN in preserving mitochondrial homeostasis, curbing mitochondrial reactive oxygen species (mtROS) generation and mtDNA leakage, consequently hindering mtDNA binding to TLR9 and subsequent activation of the NF-κB pathway. Notably, in vivo rat experiments underscored the efficacy of HN treatment in ameliorating IDD progression induced by annulus fibrosus puncture.

Conclusion

By assuaging ferroptosis in NP cells, HN exhibits promise as a viable candidate for IDD treatment, capable of impeding disease advancement. The translational potential of this article: This study highlights the importance and effectiveness of HN in alleviating IDD by inhibiting ferroptosis in NP cells. The addition of exogenous HN may represent a potential therapeutic strategy for treating IDD.

Natural Products in the Prevention of Degenerative Bone and Joint Diseases: Mechanisms Based on the Regulation of Ferroptosis

Degenerative bone and joint diseases (DBJDs), characterized by osteoporosis, osteoarthritis, and chronic inflammation of surrounding soft tissues, are systemic conditions primarily affecting the skeletal system. Ferroptosis, a programmed cell death pathway distinct from apoptosis, autophagy, and necroptosis. Accumulating evidence suggests that ferroptosis is intricately linked to the pathogenesis of DBJDs, and targeting its regulation could be beneficial in managing these conditions. Natural products, known for their anti-inflammatory and antioxidant properties, have shown unique advantages in preventing DBJDs, potentially through modulating ferroptosis. This article provides an overview of the latest research on ferroptosis, with a focus on its role in the pathogenesis of DBJDs and the therapeutic potential of natural products targeting this cell death pathway, offering novel insights for the prevention and treatment of DBJDs.

Decoding ferroptosis: transforming orthopedic disease management

As a mechanism of cell death, ferroptosis has gained popularity since 2012. The process is distinguished by iron toxicity and phospholipid accumulation, in contrast to autophagy, apoptosis, and other cell death mechanisms. It is implicated in the advancement of multiple diseases across the body. Researchers currently know that osteosarcoma, osteoporosis, and other orthopedic disorders are caused by NRF2, GPX4, and other ferroptosis star proteins. The effective relief of osteoarthritis symptoms from deterioration has been confirmed by clinical treatment with multiple ferroptosis inhibitors. At the same time, it should be reminded that the mechanisms involved in ferroptosis that regulate orthopedic diseases are not currently understood. In this manuscript, we present the discovery process of ferroptosis, the mechanisms involved in ferroptosis, and the role of ferroptosis in a variety of orthopedic diseases. We expect that this manuscript can provide a new perspective on clinical diagnosis and treatment of related diseases.

Integrating Bulk RNA and Single-Cell RNA Sequencing Identifies and Validates Lactylation-Related Signatures for Intervertebral Disc Degeneration

Glycolysis-related lactylation has gained wide attention for regulating various cellular functions and diseases. Nevertheless, its intricate involvement in intervertebral disc degeneration (IVDD) is not yet fully understood. In this study, we unrevealed the intricate association between elevated lactylation levels and the development of IVDD. Subsequently, we harvested the lactylation-related genes (LRGs) and systematically analysed the expression levels of these genes to establish a gene signature related to IVDD through multiple bulk RNA sequencing data. Six hub LRGs were determined and closely associated with the increased severity of IVDD. Among the six genes, CBX3 was the most upregulated in both in vivo and in vitro experiments. Furthermore, molecular docking identified atosiban acetate as a specific inhibitor for CBX3, and inhibiting the expression of CBX3 using atosiban acetate significantly repressed the glycolysis activity and global lactylation level, thus alleviating the progression of IVDD. In conclusion, the lactylation correlates positively with IVDD and the LRG signature could be used as a biomarker for the effective clinical treatment of IVDD. CBX3 emerged as one of the key LRGs in IVDD, and atosiban acetate, as a specific inhibitor for CBX3, may be a promising therapeutic candidate for IVDD by affecting lactylation.

Therapeutic potential of hesperidin in diabetes mellitus-induced erectile dysfunction through Nrf2-mediated ferroptosis and oxidative stress

BACKGROUND

Among erectile dysfunction (ED) caused by metabolic abnormalities, diabetes mellitus-induced ED (DMED) progresses rapidly, manifests with severe symptoms, and shows reduced responsiveness to conventional medications. Hyperglycemia in the corpus cavernosum has been linked to the induction of both ferroptosis and oxidative stress, which are mediated by nuclear factor E2 related factor 2 (Nrf2). Hesperidin (Hes), a flavonoid compound, has been revealed to activate Nrf2 in certain diabetic complications, yet the efficacy of Hes on DMED and the specific mechanism remain unclear.

OBJECTIVES

To elucidate the potential mechanism and efficacy of Hes in regulating Nrf2-mediated ferroptosis and oxidative stress in DMED.

MATERIALS AND METHODS

DMED rats were constructed through the intraperitoneal injection of streptozotocin (STZ), partially supplemented with Hes. In parallel, in vitro research utilized human umbilical vein endothelial cells (HUVECs), with glucose addition to simulating a high glucose (HG) environment, and induced with Hes or ML385 (an Nrf2 inhibitor). Penile tissues and HUVECs were harvested for subsequent analyses.

RESULTS

The results of this study indicate that Hes partially reversed the impaired erectile function. The expression of Nrf2, glutathione peroxidase 4 (GPX4), and heme oxygenase-1 (HO-1) in the corpus cavernosum elevated after supplementing with Hes, resulted in an inhibition in ferroptosis and oxidative stress. Moreover, the quantity and function of erectile effector cells were restored, and cavernous fibrosis was ameliorated. In HG-induced HUVECs, Hes ameliorated Nrf2-mediated ferroptosis and oxidative stress, effects which ML385 partially reversed.

CONCLUSIONS

Hes exerts a therapeutic effect on DMED rats and a regulatory mechanism on the Nrf2-HO-1/GPX4 axis, concurrently revitalizing endothelial and smooth muscle cells, and diminishing fibrosis. Our study provides robust preclinical evidence for employing Hes in treating DMED.

[Shenqi Tiaoshen Formula alleviates airway inflammation in rats with chronic obstructive pulmonary disease and kidney qi deficiency syndrome by inhibiting ferroptosis via regulating the Nrf2/SLC7A11/GPX4 signaling pathway]

OBJECTIVE

To investigate the effects of Shenqi Tiaoshen Formula (SQTSF) for alleviating airway inflammation in rats with both chronic obstructive pulmonary disease (COPD) and lung-kidney qi deficiency syndrome and explore its therapeutic mechanism.

METHODS

Forty-eight SD rats were randomly divided into control group, model group, low-, medium-, and high-dose SQTSF groups, and aminophylline (APL) group. In all but the control group, rat models of COPD with lung-kidney qi deficiency syndrome were established and treated with saline, SQTSF or APL via daily gavage as indicated (starting from day 30). The rats were observed for changes in body weight, grip strength, lung function, lung pathology, inflammatory cytokines in bronchoalveolar lavage fluid (BALF), oxidative stress levels, iron ion metabolism, cellular and mitochondrial ultrastructural changes in the lung tissue, and expressions of Nrf2/SLC7A11/GPX4 signaling pathway and ferroptosis-related proteins.

RESULTS

The rats in the model group exhibited obvious symptoms of lung-kidney qi deficiency syndrome with significantly decreased body weight, grip strength, and lung function parameters. Examination of the lung tissue revealed showed significant inflammatory cell infiltration and emphysema with obvious bronchial, perivascular, and alveolar inflammation and alveolar destruction, significantly increased IL-1β, TNF-α, IL-6, and IL-13 levels in BALF, and elevated pulmonary oxidative stress levels and Fe2+ and total iron ion concentrations. The rat models also showed characteristic ultrastructural changes of ferroptosis in the lung tissue cells under transmission electron microscope and significantly decreased Nrf2, GPX4, and SLC7A11 and increased ACSL4 expressions in the lung tissue. Treatment with SQTSF significantly improved these pathological changes in the rat models with a better effect than APL.

CONCLUSION

SQTSF can effectively improve airway inflammation and oxidative stress in COPD rats with lung-kidney qi deficiency possibly by inhibiting ferroptosis via regulating the Nrf2/SLC7A11/GPX4 signaling pathway.

Glutamine Mitigates Oxidative Stress-Induced Matrix Degradation, Ferroptosis, and Pyroptosis in Nucleus Pulposus Cells via Deubiquitinating and Stabilizing Nrf2

Aims: Intervertebral disc degeneration (IDD) is closely related to low back pain, which is a prevalent age-related problem worldwide; however, the mechanism underlying IDD is unknown. Glutamine, a free amino acid prevalent in plasma, is recognized for its anti-inflammatory and antioxidant properties in various diseases, and the current study aims to clarify the effect and mechanism of glutamine in IDD. Results: A synergistic interplay was observed between pyroptosis and ferroptosis within degenerated human disc specimens. Glutamine significantly mitigated IDD in both ex vivo and in vivo experimental models. Moreover, glutamine protected nucleus pulposus (NP) cells after tert-butyl hydroperoxide (TBHP)-induced pyroptosis, ferroptosis, and extracellular matrix (ECM) degradation in vitro. Glutamine protected NP cells from TBHP-induced ferroptosis by promoting the nuclear factor erythroid 2-related factor 2 (Nrf2) accumulation by inhibiting its ubiquitin-proteasome degradation and inhibiting lipid oxidation. Innovation and Conclusions: A direct correlation is evident in the progression of IDD between the processes of pyroptosis and ferroptosis. Glutamine suppressed oxidative stress-induced cellular processes, including pyroptosis, ferroptosis, and ECM degradation through deubiquitinating Nrf2 and inhibiting lipid oxidation in NP cells. Glutamine is a promising novel therapeutic target for the management of IDD.

[Effect and molecular mechanism of hesperadin-induced ferroptosis in chronic myeloid leukemia K562 cells]

Objective: To investigate the effect and molecular mechanism of hesperadin in inducing ferroptosis in chronic myeloid leukemia cell line K562 cells. Methods: The effects of hesperadin on the viability, proliferation, and migration of K562 cells were detected though CCK8, EDU-594, and Transwell assays, and the apoptotic rate of K562 cells was detected by flow cytometry. In addition, C11-BODIPY and FerroOrange were utilized to detect intracellular lipid peroxidation and Fe(2+) levels. Meanwhile, the expression levels of ferroptosis-associated protein solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) in cells were detected through Western blot. Lipid peroxidation and Fe(2+) levels were also detected after transfection of cells with SLC7A11 overexpression plasmid. Results: Hesperadin decreased cell viability in a dose-dependent manner with IC(50) of 0.544 μmol/L. Hesperadin concentrations of 0.4 and 0.8 μmol/L were selected for follow-up experiments. EDU-594, Transwell, and flow cytometry showed significantly decreased proliferation and migration rate of K562 cells after 0.4 and 0.8 μmol/L hesperadin treatment for 24 h, and the apoptosis rate was significantly increased compared with the control group (P<0.05). Western blot indicated a downregulated expression of the antiapoptotic protein Bcl-2 and an elevated expression of proapoptotic proteins Bax and Caspase-3. Moreover, hesperadin increased intracellular lipid peroxidation and Fe(2+) levels compared with the control treatment (P<0.05). The combination of ferroptosis inhibitor (Fer-1) and hesperadin could reverse the effect of hesperadin on K562 cells. The mRNA and protein levels of ferroptosis-related genes SLC7A11 and GPX4 were significantly decreased in the 0.8 μmol/L hesperadin-treated group (P<0.05). SLC7A11 overexpression can inhibit hesperadin effect and alleviate ferroptosis. Conclusion: Hesperadin can promote ferroptosis in K562 cells by regulating the SLC7A11/GPX4 axis.

Ferroptosis inhibitors: past, present and future

Ferroptosis is a non-apoptotic mode of programmed cell death characterized by iron dependence and lipid peroxidation. Since the ferroptosis was proposed, researchers have revealed the mechanisms of its formation and continue to explore effective inhibitors of ferroptosis in disease. Recent studies have shown a correlation between ferroptosis and the pathological mechanisms of neurodegenerative diseases, as well as diseases involving tissue or organ damage. Acting on ferroptosis-related targets may provide new strategies for the treatment of ferroptosis-mediated diseases. This article specifically describes the metabolic pathways of ferroptosis and summarizes the reported mechanisms of action of natural and synthetic small molecule inhibitors of ferroptosis and their efficacy in disease. The paper also describes ferroptosis treatments such as gene therapy, cell therapy, and nanotechnology, and summarises the challenges encountered in the clinical translation of ferroptosis inhibitors. Finally, the relationship between ferroptosis and other modes of cell death is discussed, hopefully paving the way for future drug design and discovery.

Research on the role and mechanism of IL-17 in intervertebral disc degeneration

Intervertebral disc degeneration (IDD) is one of the primary causes of low back pain (LBP), which seriously affects patients' quality of life. In recent years, interleukin (IL)-17 has been shown to be highly expressed in the intervertebral disc (IVD) tissues and serum of patients with IDD, and IL-17A has been shown to promote IDD through multiple pathways. We first searched databases such as PubMed, Cochrane, Embase, and Web of Science using the search terms "IL-17 or interleukin 17″ and "intervertebral discs". The search period ranged from the inception of the databases to December 2023. A total of 24 articles were selected after full-text screening. The main conclusion of the clinical studies was that IL-17A levels are significantly increased in the IVD tissues and serum of IDD patients. The results from the in vitro studies indicated that IL-17A can activate signaling pathways such as the NF-κB and MAPK pathways; promote inflammatory responses, extracellular matrix degradation, and angiogenesis; and inhibit autophagy in nucleus pulposus cells. The main finding of the in vivo experiments was that puncture of animal IVDs resulted in elevated levels of IL-17A within the IVD, thereby inducing IDD. Clinical studies, in vitro experiments, and in vivo experiments confirmed that IL-17A is closely related to IDD. Therefore, drugs that target IL-17A may be novel treatments for IDD, providing a new theoretical basis for IDD therapy.

Hesperetin promotes diabetic wound healing by inhibiting ferroptosis through the activation of SIRT3

Hesperetin (HST) is a flavonoid compound naturally occurring in citrus fruits and is widespread in various traditional medicinal herbs such as grapefruit peel, orange peel, and tangerine peel. These plant materials are commonly used in traditional Chinese medicine to prepare herbal remedies. The study aimed to investigate the potential molecular mechanisms through which HST reduces ferroptosis in human umbilical vein endothelial cells (HUVECs) and promotes angiogenesis and wound healing. We employed network pharmacology to predict the downstream targets affected by HST. The expression of markers related to ferroptosis was assessed through Western blot (WB) and polymerase chain reaction. Intracellular levels of ferroptosis-related metabolism were examined using glutathione/oxidized glutathione (GSH/GSSG) and malondialdehyde (MDA) assay kits. Mitochondrial status and iron levels within the cells were investigated through staining with Mitosox, FerroOrange, and JC1 staining. Potential downstream direct targets of HST were identified using molecular docking. Additionally, wound healing and neovascularization within the wound site were analyzed using various methods including HE staining, Masson's staining, immunohistochemistry, and Doppler hemodynamics assessment. HST effectively inhibits the elevated levels of intracellular ferroptosis stimulated by ERASTIN. Furthermore, we observed that HST achieves this inhibition of ferroptosis by activating SIRT3. In a diabetic rat wound model, HST significantly promotes wound healing, reducing levels of tissue ferroptosis, consistent with our in vitro findings. This study demonstrates that HST can inhibit the progression of ferroptosis and protect the physiological function of HUVECs by activating SIRT3. HST holds promise as a natural compound for promoting diabetic wound healing.

Natural product-derived ferroptosis mediators

It has been 11 years since ferroptosis, a new mode of programmed cell death, was first proposed. Natural products are an important source of drug discovery. In the past five years, natural product-derived ferroptosis regulators have been discovered in an endless stream. Herein, 178 natural products discovered so far to trigger or resist ferroptosis are classified into 6 structural classes based on skeleton type, and the mechanisms of action that have been reported are elaborated upon. If pharmacodynamic data are sufficient, the structure and bioactivity relationship is also presented. This review will provide medicinal chemists with some effective ferroptosis regulators, which will promote the research of natural product-based treatment of ferroptosis-related diseases in the future.

Strontium Ranelate Ameliorates Intervertebral Disc Degeneration via Regulating TGF-β1/NF-κB Axis

Intervertebral disc degeneration (IVDD) is a prevalent and debilitating condition characterized by chronic back pain and reduced quality of life. Strontium ranelate (SRR) is a compound traditionally used for treating osteoporosis via activating TGF-β1 signaling pathway. Recent studies have proved the anti-inflammatory effect of SRR on chondrocytes. Although the exact mechanism of IVDD remains unclear, accumulating evidences have emphasized the involvement of multifactorial pathogenesis including inflammation, oxidative stress damage, and etc. However, the biological effect of SRR on IVDD and its molecular mechanism has not been investigated. Firstly, this study proved the decreased expression of Transforming Growth Factor-beta 1(TGF-β1) in degenerated human intervertebral disc tissues. Subsequently, we confirmed for the first time that SRR could promote cell proliferation, mitigate inflammation and oxidative stress in human nucleus pulposus cells in vitro via increasing the expression of TGF-β1 and suppressing the Nuclear Factor Kappa-Light-Chain-Enhancer of Activated B Cells (NF-κB) pathway. The molecular docking result proved the interaction between SRR and TGF-β1 protein. To further verify this interaction, gain- and loss- of function experiments were conducted. We discovered that both TGF-β1 knockdown and overexpression influenced the activation of the NF-κB pathway. Taken together, SRR could mitigate IL-1β induced-cell dysfunction in human nucleus pulposus cells by regulating TGF-β1/NF-κB axis in vitro. Finally, the in vivo therapeutic effect of SRR on IVDD was confirmed. Our findings may contribute to the understanding of the complex interplay between inflammation and degenerative processes in the intervertebral disc and provide valuable insights into the development of targeted treatment-based therapeutics for IVDD.

The role of ferroptosis in intervertebral disc degeneration

Nucleus pulposus, annulus fibrosus, and cartilage endplate constitute an avascular intervertebral disc (IVD), which is crucial for spinal and intervertebral joint mobility. As one of the most widespread health issues worldwide, intervertebral disc degeneration (IVDD) is recognized as a key contributor to back and neck discomfort. A number of degenerative disorders have a strong correlation with ferroptosis, a recently identified novel regulated cell death (RCD) characterized by an iron-dependent mechanism and a buildup of lipid reactive oxygen species (ROS). There is growing interest in the part ferroptosis plays in IVDD pathophysiology. Inhibiting ferroptosis has been shown to control IVDD development. Several studies have demonstrated that in TBHP-induced oxidative stress models, changes in ferroptosis marker protein levels and increased lipid peroxidation lead to the degeneration of intervertebral disc cells, which subsequently aggravates IVDD. Similarly, IVDD is significantly relieved with the use of ferroptosis inhibitors. The purpose of this review was threefold: 1) to discuss the occurrence of ferroptosis in IVDD; 2) to understand the mechanism of ferroptosis and its role in IVDD pathophysiology; and 3) to investigate the feasibility and prospect of ferroptosis in IVDD treatment.