Ferroptotic mechanisms and therapeutic targeting of iron metabolism and lipid peroxidation in the kidney

Injectable and adhesive MgO2-potentiated hydrogel with sequential tumor synergistic therapy and osteogenesis for challenging postsurgical osteosarcoma treatment

The clinical treatment of osteosarcoma faces great challenges of residual tumor cells leading to tumor recurrence and irregular bone defects difficult to repair after surgery removal of the primary tumor tissue. We developed an injectable and in-situ cross-linkable hydrogel (named MOG hydrogel) using MgO2 nanoparticles and dopamine-conjugated gelatin as main components. MgO2 was rationally designed as a multifunctional active ingredient to mediate in situ gelation, tumor therapy, and bone repair sequentially. The 10MOG (with 10 mg/mL MgO2 content) showed excellent gel stability, injectability, shape adaptability, tissue adhesion, and rapid hemostatic ability. Importantly, 10MOG exhibited ideal sequential H2O2 and Mg2+ release property. The released H2O2 synergized with photothermal therapy for enhanced tumor recurrence suppression, and the sustainable Mg2+ release efficiently promoted bone regeneration. The MOG hydrogel, possessing excellent on-demand antitumor and osteogenic capabilities in vitro and in vivo, exhibited tremendous potential in the clinical application for challenging postsurgical osteosarcoma treatment.

Crucial roles of asprosin in cisplatin-induced ferroptosis and acute kidney injury

Ferroptosis is a type of non-apoptotic regulated cell death characterized by iron accumulation and lipid peroxidation. Cisplatin is an effective chemotherapy drug with several serious side effects including acute kidney injury (AKI). Asprosin is a peptide contributing to metabolism regulation and metabolic disorders. This study aimed to determine the role and mechanism of asprosin in AKI. Cisplatin was used to induce cell damage in mouse renal tubular epithelial (TCMK-1) cells and AKI in C57BL/6 mice. Cisplatin caused asprosin upregulation in cisplatin-treated TCMK-1 cells and mice. In TCMK-1 cells, asprosin overexpression led to iron overload and lipid peroxidation, while asprosin knockdown attenuated cisplatin-induced iron overload, lipid peroxidation and ferroptosis. Exogenous asprosin promoted cell damage and ferroptosis, which were attenuated by ferroptosis inhibitors. Asprosin-induced iron overload, lipid peroxidation, cell damage and SMAD1/5/8 phosphorylation were prevented by bone morphogenetic protein (BMP) type I receptor inhibitor. Integrin antagonist prevented asprosin-induced SMAD1/5/8 phosphorylation, and asprosin can specifically bind to integrin β3. Inhibition of integrin β3 reduced the asprosin-induced increases in Fe2+ and MDA levels. Asprosin knockdown relieved cisplatin-induced hepcidin upregulation, while hepcidin knockdown attenuated asprosin-induced iron overload, lipid peroxidation and ferroptosis. In cisplatin-induced AKI mice, specific knockdown of asprosin in the kidney not only attenuated renal dysfunction and damage, but also alleviated iron overload, lipid peroxidation and ferroptosis. These results indicated that excessively increased asprosin promotes TCMK-1 cells ferroptosis and damage via integrin β3/BMP/hepcidin-mediated iron overload and lipid peroxidation. Silencing of asprosin attenuates renal injury and dysfunction in cisplatin-induced AKI by inhibiting ferroptosis.

Leech granules inhibit ferroptosis and alleviate renal injury in mice with diabetic kidney disease

ETHNOPHARMACOLOGICAL RELEVANCE

The underlying mechanisms of diabetic kidney disease (DKD) and effective treatment strategies remain unclear. DKD progression is closely associated with abnormal iron metabolism and ferroptosis in vivo. Leeches, used in traditional Chinese medicine for promoting blood circulation and resolving blood stasis, are utilized to treat diabetes and its associated complications. Leeches effectively antagonize oxidative stress injury and exert protective effects on renal function. However, whether leeches can inhibit ferroptosis by modulating oxidative stress and iron metabolism remains unclear.

AIM OF THE STUDY

To investigate the therapeutic potential of leech granules in DKD and, specifically, their effects on ferroptosis.

MATERIALS AND METHODS

We used a mouse model of DKD. The mice were treated with leech granules via gavage. Component identification and analysis of leech granules were performed using UPLC-MS, and efficacy was assessed by histopathology and analysis of blood glucose, lipids, and renal function. Additionally, the pharmacological mechanisms of leech granules were explored via proteomics, immunohistochemical staining, western blotting, and cell culture.

RESULTS

Proteomic analysis showed that iron metabolism was dysregulated and ferroptosis increased in DKD mice. Leech granules significantly reduced iron accumulation and renal pathological damage, decreased ROS levels, upregulated GSH levels, and inhibited ferroptosis in the kidneys of DKD mice. Furthermore, in vitro cellular experiments demonstrated that leech granules could inhibit erastin-induced ferroptosis and protect renal cells.

CONCLUSIONS

The regulation of renal iron metabolism and inhibition of ferroptosis mediates the therapeutic effect of leech granules on DKD. Leech granules represent a promising approach for DKD treatment.

T-2 toxin triggers immunotoxic effects in goats by inducing ferroptosis and neutrophil extracellular traps

T-2 toxin, a prevalent mycotoxin, represents a notable global public health risk. Neutrophil extracellular traps (NETs) and ferroptosis are involved in a variety of pathophysiological processes and are implicated in goat immunity. However, the impact of T-2 toxin on NETs release, ferroptosis, and their interplay have not been previously documented. In this study, neutrophils were stimulated with T-2 toxin for 4 h. The structure and mechanism of NETs were analyzed using immunofluorescence and Pico Green staining. The expressions of glutathione peroxidase 4 (GPX4) and ferritin (FT) was quantified by qRT-PCR and western blotting. The levels of ROS and lipid ROS were assessed using DCFH-DA and C11 BODIPY 581/591 probes, and cellular mitochondria Fe2+ were detected by using Mito-FerroGreen probe. Inhibitors were utilized to explore the interaction between these two processes. The results confirmed that the T-2 toxin stimulated the NETs production, characterized by a structure co-modified by citrullinated histones (citH3), neutrophil elastase (NE) and DNA. Notably, significant inhibition of NETs production by T-2 toxin was observed with the NOX inhibitor DPI (P < 0.001), the ERK inhibitor U0126 (P < 0.001), the TLR2 inhibitor C29 (P < 0.001), and the TLR4 inhibitor TLR4-IN-C34 (P < 0.001). T-2 toxin triggered ferroptosis in neutrophils by suppressing GPX4 and FT expression, elevating ROS and lipid ROS, and augmenting the concentration of mitochondrial Fe2+. The ferroptosis inhibitor Fer-1 could rescue this induction; however, Fer-1 was unable to inhibit NETs which is induced by T-2 toxin. Conversely, T-2 toxin effectively triggered the downregulation of GPX4, which was counteracted by DPI, U0126, C29, and C34. This research elucidates the immunotoxic mechanisms of T-2 toxin in goat neutrophils and offers a novel perspective on preventing and treating T-2 toxin.

Exploring Liraglutide's mechanism in reducing renal fibrosis: the Fsp1-CoQ10-NAD(P)H pathway

Studies have confirmed that elevated glucose levels could lead to renal fibrosis through the process of ferroptosis. Liraglutide, a human glucagon-like peptide-1 (GLP-1) analogue, is a potential treatment option for diabetes. This study aimed to examine the potential of liraglutide (LIRA) in inhibiting ferroptosis and reducing high glucose-induced renal fibrotic injury in mice, and whether the Fsp1-CoQ10-NAD(P)H signal pathway is a mechanism for this effect. In our study, we used db/db mice to simulate Type 2 diabetes mellitus (T2DM). The mice were intraperitoneally injected with LIRA (200 µg/kg/d) daily for 6 weeks. Renal function, pathologic changes, lipid peroxidation levels, iron levels, and ferroptosis were assessed. First, LIRA ameliorated renal dysfunction and fibrosis in db/db mice. Second, LIRA inhibited lipid peroxidation by up-regulating T-SOD, GSH-Px, and GSH activities as well as down-regulating the levels of 8-OHDG, MDA, LPO, 4-HNE, 12-Lox, and NOX4 in db/db mice. In addition, LIRA attenuated iron deposition by decreasing the expression of TfR1 and increasing the expression of FPN1. Meanwhile, LIRA reduced high levels of high glucose-induced cell viability decline and intracellular lipid peroxidation. Furthermore, LIRA inhibited ferroptosis by adjusting the Fsp1-CoQ10-NAD(P)H pathway in vivo and in vitro. These findings suggested that LIRA attenuated kidney fibrosis injury in db/db mice by inhibiting ferroptosis through the Fsp1-CoQ10-NAD(P)H pathway.

Research hotspots and future trends in sepsis-associated acute kidney injury: a bibliometric and visualization analysis

Objectives

Sepsis-associated acute kidney injury (SA-AKI) commonly occurs in critically ill patients and is closely associated with adverse outcomes. A comprehensive analysis of the current research landscape in SA-AKI can help uncover trends and key issues in this field. This study aims to provide a scientific basis for research directions and critical issues through bibliometric analysis.

Methods

We searched all articles on SA-AKI indexed in the SCI-Expanded of WoSCC up to May 7, 2024, and conducted bibliometric and visual analyses using bibliometric software CiteSpace and VOSviewer.

Results

Over the past 20 years, there has been a steady increase in literature related to renal repair following AKI. China and the United States contribute over 60% of the publications, driving research in this field. The University of Pittsburgh is the most active academic institution, producing the highest number of publications. J. A. Kellum is both the most prolific and the most cited author in this area. "Shock" and "American Journal of Physiology-Renal Physiology" are the most popular journals, publishing the highest number of articles. Recent high-frequency keywords in this field include "septic AKI," "mitochondrial dysfunction," "inflammasome," "ferroptosis," and "macrophage." The terms "mitochondrial dysfunction," "inflammasome," "ferroptosis," and "macrophage" represent current research hotspots and potential targets in this area.

Conclusion

This is the first comprehensive bibliometric study to summarize the trends and advancements in SA-AKI research in recent years. These findings identify current research frontiers and hot topics, providing valuable insights for scholars studying SA-AKI.

Iron-Mediated Regulation in Adipose Tissue: A Comprehensive Review of Metabolism and Physiological Effects

PURPOSE OF REVIEW

Review the latest data regarding the intersection of adipose tissue (AT) and iron to meet the needs of AT metabolism and the progression of related diseases.

RECENT FINDINGS

Iron is involved in fundamental biological metabolic processes and is precisely fine-tuned within the body to maintain cellular, tissue and even systemic iron homeostasis. AT not only serves as an energy storage depot but also represents the largest endocrine organ in the human body, maintaining systemic metabolic homeostasis. It is involved in physiological processes such as energy storage, insulin sensitivity regulation and lipid metabolism. As a unique iron-sensing tissue, AT expresses related regulatory factors, including the classic hepcidin, ferroportin (FPN), iron regulatory protein/iron responsive element (IRP/IRE) and ferritin. Consequently, the interaction between AT and iron is intricately intertwined. Imbalance of iron homeostasis produces the potential risks of steatosis, impaired glucose tolerance and insulin resistance, leading to AT dysfunction diseases, including obesity, type 2 diabetes and metabolic dysfunction-associated steatotic liver disease (MASLD). Despite the role of AT iron has garnered increasing attention in recent years, a comprehensive review that systematically organizes the connection between iron and AT remains lacking. Given the necessity of iron homeostasis, emphasizing its potential impact on AT function and metabolism regulation provides valuable insights into physiological effects such as adipocyte differentiation and thermogenesis. Futhermore, regulators including adipokines, mitochondria and macrophages have been mentioned, along with analyzing the novel perspective of iron as a key mediator influencing the fat-gut crosstalk.

Nebulized Immunotherapy of Orthotopic Lung Cancer by Mild Magnetothermal-Based Innate Immunity Activations

Advances in adaptive immunity have greatly contributed to the development of cancer immunotherapy. However, its over-low efficacy and insufficient invasion of immune cells in the tumor tissue, and safety problems caused by cytokine storm, have seriously impeded further clinical application for solid tumor immunotherapy. Notably, the immune microenvironment of the lungs is naturally enriched with alveolar macrophages (AMs). Herein, we introduce a novel nebulized magnetothermal immunotherapy strategy to treat orthotopic lung cancer by using magnetothermal nanomaterial (Zn-CoFe2O4@Zn-MnFe2O4-PEG, named ZCMP), which can release iron ions via an acid/thermal-catalytic reaction to maximize the use of lung's immune environment through the cascade activations of AMs and natural killer (NK) cells. Nebulized administration greatly enhance drug bioavailability by localized drug accumulation at the lesion site. Upon mild magnetic hyperthermia, the released iron ions catalyze endogenous H2O2 decomposition to produce reactive oxygen species (ROS), which triggers the M1 polarization of AMs, and the resultant inflammatory cytokine IFN-β, IL-1β and IL-15 releases to activate c-Jun, STAT5 and GZMB related signaling pathways, promoting NK cells proliferation and activation. This innovative strategy optimally utilizes the lung's immune environment and shows excellent immunotherapeutic outcomes against orthotopic lung cancer.

Ultrasmall Black Phosphorus Quantum Dots with Robust Antioxidative Properties for Acute Kidney and Liver Injury Therapy

Acute organ injuries, such as acute kidney injury (AKI) and acute liver injury (ALI), usually present high morbidity and mortality in patients. However, the current clinical treatments remain limited, especially the lack of effective drug-based treatment. Since these acute injuries are often associated with reactive oxygen species (ROS) overproduction, it is a promising strategy to develop therapeutic agents with potent ROS scavenging ability and excellent biocompatibility for efficient antioxidation therapy. Black phosphorus quantum dots (BPQDs), low-dimensional nanomaterials prepared through a straightforward one-step method and capable of complete controllable biodegradation, offer significant potential. This study comprehensively explores the extensive free-radical scavenging capabilities of BPQDs, underscoring their immense potential in treating ROS-related organ injuries. BPQDs could simultaneously achieve radical scavenging of DPPH, ABTS·, OH·, and O2 -· and exhibit excellent cytoprotective effects against ROS-mediated damage even at extremely low dosages. Besides, the ultrasmall size of BPQDs (≈3-5 nm) allows them to effectively penetrate the glomerular filtration barrier (≈6 nm), significantly improving the symptoms of AKI and ALI in vivo. The therapeutic efficacy and great biocompatibility of BPQDs facilitate the clinical management of ROS-related diseases, which will broaden the applications of QDs in the field of biomedicine.

Ginsenoside Rb1 targets to HO-1 to improve sepsis by inhibiting ferroptosis

Sepsis remains the leading cause of mortality among Intensive Care Unit (ICU) patients, with its pathogenesis and treatment not yet fully elucidated. Ferroptosis plays a critical role in sepsis, suggesting that ferroptosis-related genes may serve as potential therapeutic targets. This study aims to identify key ferroptosis-related genes in sepsis and explore targeted therapeutics. Through differential expression analysis of the GSE13940 and GSE26440 datasets, heme oxygenase-1 (HO-1) was identified as a hub gene associated with ferroptosis. Additionally, single-cell analysis of the GSE175453 dataset revealed a significant upregulation of HO-1 expression in monocyte lineages during sepsis. The cecal ligation and puncture (CLP) method was employed to induce sepsis in a mouse model, lung and intestinal tissues exhibited typical ferroptosis characteristics, with a significant increase in HO-1 expression. However, treatment with the HO-1 inhibitor zinc protoporphyrin (ZNPP) significantly ameliorated ferroptosis in CLP-induced lung and intestinal tissues, as well as in lipopolysaccharide (LPS)-induced THP-1 cells. Subsequently, molecular docking, surface plasmon resonance (SPR), and microscale thermophoresis (MST) experiments demonstrated that ginsenoside Rb1 specifically targets HO-1, identifying K18A as the key binding residue. Finally, experiments conducted both in vitro and in vivo verified that ginsenoside Rb1 significantly reduces HO-1 expression, inhibits ferroptosis in sepsis-induced lung, and intestinal tissues and THP-1 cells, and improves sepsis-induced pulmonary and intestinal damage. In conclusion, this study identifies HO-1 as a key ferroptosis target in sepsis and suggests ginsenoside Rb1 as a potential novel HO-1 inhibitor for the therapeutic approach of sepsis-induced organ dysfunction.

Radish red attenuates chronic kidney disease in obese mice through repressing oxidative stress and ferroptosis via Nrf2 signaling improvement

Chronic kidney disease (CKD) presents a significant public health concern, with obesity being a prominent contributing factor to kidney disorders by inducing oxidative stress, lipotoxicity, and tubular cell injury. Natural anthocyanins extracted from red radishes (Raphanus sativus L.) exert antioxidant and anti-apoptotic functions. This study aims to employ a novel natural pigment anthocyanin, referred to as radish red (RR) isolated from red radishes, to alleviate obesity-related metabolic disturbances and kidney impairment in a CKD mouse model induced by high-fat and high-fructose diets (HFFD). The in vitro study initially demonstrated that RR treatment significantly mitigated the palmitate acid (PA)-induced injury and cytotoxicity in human tubular epithelial HK2 cells. Subsequently, RR supplementation notably improved obesity and associated metabolic dysfunctions in mice caused by HFFD. Abnormal renal function indices including serum creatinine, blood urea nitrogen (BUN), uric acid (UA), urine protein, albuminuria and urine albumin-to-creatinine ratio (UACR) were detected in HFFD-fed mice, which were effectively alleviated by RR treatment. Histologically, renal tubular cell injury, lipid deposition, tubular dilatation, and renal fibrosis induced by HFFD were markedly improved after RR administration in mice. Furthermore, RR treatment significantly alleviated oxidative stress in HFFD-fed mice, as evidenced by the decreased renal reactive oxygen species (ROS) production, 4-HNE, and NOX4 expression levels. Anti-oxidants such as superoxide dismutase-1 (SOD1), NAD (P) H: quinone oxidoreductase (NQO1), heme oxygenase-1 (HO-1) and glutamate cysteine ligase (GCLC) were highly upregulated in kidney of HFFD-fed mice with RR consumption through improving NFE2-related factor 2 (Nrf2) signaling activation. Furthermore, ferroptosis was identified in the kidneys of HFFD-fed mice, evidenced by the elevated levels of malondialdehyde (MDA), iron content, and lipid peroxidation, along with the decreased expression of glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11). These occurrences were significantly mitigated following RR treatment. Mechanistically, we further discovered that the suppressive effects of RR in restricting oxidative stress, ferroptosis, lipid accumulation, and injury of tubular epithelial cells induced by PA were significantly counteracted by Nrf2 knockdown. Collectively, our results demonstrated that dietary supplementation with RR could potentially serve as an efficacious therapeutic modality for the management of obesity-related CKD progression by enhancing Nrf2 activation to impede oxidative stress and ferroptosis.

Targeting PTGDS Promotes ferroptosis in peripheral T cell lymphoma through regulating HMOX1-mediated iron metabolism

BACKGROUND

Peripheral T cell lymphoma (PTCL) is characterized by high heterogeneity, strong aggressiveness, and extremely poor prognosis. Ferroptosis, a novel form of programmed cell death, has been involved in tumor development and targeting ferroptosis holds great potential for tumor therapy.

METHODS

Lentiviral transfection was performed to regulate gene expression, followed by Tandem mass tag (TMT)-mass spectrometry and RNA-sequencing. Tumor xenograft models were established for in vivo experiments.

RESULTS

High expression of prostaglandin D2 synthase (PTGDS) was closely associated with poor prognosis of PTCL patients. PTGDS knockdown and AT56 treatment significantly inhibited the progression of PTCL through regulating cell viability, proliferation, apoptosis, cell cycle and invasion in vitro and in vivo. We further revealed that targeting PTGDS promoted ferroptosis process and enhanced the sensitivity of PTCL cells to ferroptosis inducers Sorafenib in vitro and in vivo. Mechanically, PTGDS interacted with heme-degrading enzymes HMOX1, and targeting PTGDS increased the level of iron and induced ferroptosis in PTCL through promoting HMOX1-mediated heme catabolism and ferritin autophagy process. Through the construction of H25A mutation, the specific gene site of HMOX1 corresponding to its role was identified.

CONCLUSIONS

Taken together, our findings firstly identified that targeting PTGDS promotes the ferroptosis in PTCL through regulating HMOX1-mediated iron metabolism, and highlighted novel therapeutic strategies to improve the efficacy of ferroptosis-targeted therapy in PTCL patients.

The role of ferroptosis-related non-coding RNA in liver fibrosis

Liver fibrosis represents a reversible pathophysiological process, caused by chronic inflammation stemming from hepatocyte damage. It delineates the initial stage in the progression of chronic liver disease. This pathological progression is characterized by the excessive accumulation of the extracellular matrix (ECM), which leads to significant structural disruption and ultimately impairs liver function. To date, no specific antifibrotic drugs have been developed, and advanced liver fibrosis remains largely incurable. Liver transplantation remains the sole efficacious intervention for advanced liver fibrosis; nevertheless, it is constrained by exorbitant costs and the risk of postoperative immune rejection, underscoring the imperative for novel therapeutic strategies. Ferroptosis, an emergent form of regulated cell death, has been identified as a pivotal regulatory mechanism in the development of liver fibrosis and is intricately linked with the progression of liver diseases. Recent investigations have elucidated that a diverse array of non-coding RNAs (ncRNAs), including microRNAs, long non-coding RNAs, and circular RNAs, are involved in the ferroptosis pathway, thereby modulating the progression of various diseases, including liver fibrosis. In recent years, the roles of ferroptosis and ferroptosis-related ncRNAs in liver fibrosis have attracted escalating scholarly attention. This paper elucidates the pathophysiology of liver fibrosis, explores the mechanisms underlying ferroptosis, and delineates the involvement of ncRNA-mediated ferroptosis pathways in the pathology of liver fibrosis. It aims to propose novel strategies for the prevention and therapeutic intervention of liver fibrosis.

RTA408 alleviates lipopolysaccharide-induced acute lung injury via inhibiting Bach1-mediated ferroptosis

The approved traditional Asian medicine RTA408 (Omaveloxolone) has demonstrated potent anti-inflammatory properties in the treatment of Friedreich's ataxia. However, its effect on lipopolysaccharide (LPS)-induced acute lung injury (ALI) remains poorly understood. This study aims to evaluate the effect of RTA408 on LPS-induced ALI and elucidate its underlying mechanisms. In this study, in vivo experiments demonstrated that RTA408 significantly ameliorated LPS-induced mouse ALI, characterized by reduced pathological damage and neutrophil infiltration as well as decreased lung edema of murine lung tissues. Moreover, LPS administration induced ferroptosis in ALI mice, evidenced by increased MDA levels, reduced GSH and SOD activity, and decreased expression of ferroptosis repressors (GPX4 and SLC7A11), whereas RTA408 reversed these changes. Consistently, RTA408 reduced ferroptosis and improved cell damage in LPS-stimulated MLE-12 cells, as evidenced by decreased ROS and MDA levels, increased SOD, GSH activity and ferroptosis repressors expression. Meanwhile, the protective effective of RTA408 on LPS-induced oxidative damage was blocked by ferroptosis inhibitor ferrostatin-1 (Fer-1). Mechanistic studies demonstrated that RTA408 inhibited the expression and nuclear translocation of Bach1, and the anti-ferroptosis effect was diminished by Bach1 siRNA or Bach1 knockout (Bach1-/-) mice. Furthermore, Bach1-/- mice exhibited attenuated ALI induced by LPS compared to wild-type (WT) mice, and the protective effect of RTA408 on LPS-challenged ALI was not observed in Bach1-/- mice. In conclusion, our data suggested that RTA408 alleviates LPS-induced ALI by interfering Bach1-mediated ferroptosis and might be a novel candidate for LPS-induced ALI/ARDS therapy.

The connection between autophagy and ferroptosis in AKI: recent advances regarding selective autophagy

Acute kidney injury (AKI) is a significant issue in public health, displaying a high occurrence rate and mortality rate. Ferroptosis, a form of programmed cell death (PCD), is characterized by iron accumulation and intensified lipid peroxidation. Recent studies have demonstrated the pivotal significance of ferroptosis in AKI caused by diverse stimuli, including ischemia-reperfusion injury (IRI), sepsis and toxins. Autophagy, a multistep process that targets damaged organelles and macromolecules for degradation and recycling, also plays an essential role in AKI. Previous research has demonstrated that autophagy deletion in proximal tubules could aggravate tubular injury and renal function loss, indicating the protective function of autophagy in AKI. Consequently, finding ways to stimulate autophagy has become a crucial therapeutic strategy. The recent discovery of the role of selective autophagy in influencing ferroptosis has identified new therapeutic targets for AKI and has highlighted the importance of understanding the cross-talk between autophagy and ferroptosis. This study aims to provide an overview of the signaling pathways involved in ferroptosis and autophagy, focusing on the mechanisms and functions of selective autophagy and autophagy-dependent ferroptosis. We hope to establish a foundation for future investigations into the interaction between autophagy and ferroptosis in AKI as well as other diseases.

Ferroptosis: Potential therapeutic targets and prognostic predictions for acute myeloid leukemia (Review)

Ferroptosis is a relatively recently discovered type of regulated cell death that is induced by iron-dependent lipid peroxidation. The key contributing factors to ferroptosis are the loss of glutathione peroxidase 4 which is required for reversing lipid peroxidation, the buildup of redox-active iron and the oxidation of phospholipids containing polyunsaturated fatty acids. Ferroptosis has been associated with a number of diseases, including cancers such as hepatocellular carcinoma, breast cancer, acute renal damage and neurological disorders such as Alzheimer's disease and Alzheimer's disease, and there may be an association between ferroptosis and acute myeloid leukemia (AML). The present review aims to describe the primary regulatory pathways of ferroptosis, and the relationship between ferroptosis and the occurrence and development of AML. Furthermore, the present review comprehensively summarizes the latest advances in the treatment and prognosis of ferroptosis in AML.

Exploring the role and therapeutic potential of lipid metabolism in acute kidney injury

Acute kidney injury (AKI) is a prevalent condition, yet no specific treatment is available. Extensive research has revealed the pivotal role of lipid-related alterations in AKI. Lipid metabolism plays an essential role in the sustenance of the kidneys. In addition to their energy-supplying function, lipids contribute to the formation of renal biomembranes and the establishment of the renal microenvironment. Moreover, lipids or their metabolites actively participate in signal transduction, which governs various vital biological processes, such as proliferation, differentiation, apoptosis, autophagy, and epithelial-mesenchymal transition. While previous studies have focused predominantly on abnormalities in lipid metabolism in chronic kidney disease, this review focuses on lipid metabolism anomalies in AKI. We explore the significance of lipid metabolism products as potential biomarkers for the early diagnosis and classification of AKI. Additionally, this review assesses current preclinical investigations on the modulation of lipid metabolism in the progression of AKI. Finally, on the basis of existing research, this review proposes future directions, highlights challenges, and presents novel targets and innovative ideas for the treatment of and intervention in AKI.

Imperatorin ameliorates ferroptotic cell death, inflammation, and renal fibrosis in a unilateral ureteral obstruction mouse model

BACKGROUND

Imperatorin is a naturally occurring furocoumarin derivative found in traditional Chinese medicine Angelica dahurica for its anticancer, antihypertensive, and antidiabetic properties. Chronic kidney disease (CKD) is a global health issue, characterized by a high prevalence, significant morbidity and mortality, and a range of related complications.

OBJECTIVE

This study aims to investigate the protective effects of imperatorin treatment and the specific underlying mechanisms in progressive CKD.

METHODS

Imperatorin was orally administrated for 14 consecutive days to mice with unilateral ureteral obstruction (UUO) to investigate the renal pathological alternations, pro-inflammatory mediators, antioxidant response, and ferroptotic death signaling. Imperatorin was also tested in the erastin-induced injury of renal proximal tubular cells (NRK-52E). Cell viability, ferroptosis protein markers, erastin-induced oxidative stress, and lipid peroxidation were assessed.

RESULTS

In vivo, imperatorin treatment alleviated kidney histology alternations and attenuated the protein expression of fibrotic markers. Furthermore, imperatorin administration reduced inflammatory cell infiltration, and alleviated the oxidative stress burden by downregulating protein markers such as catalase, superoxide dismutase 2 (SOD-2), NADPH oxidase 4 (NOX-4), and thioredoxin reductase 1 (Trxr-1). It also mitigated ferroptosis markers such as glutathione peroxidase 4 (GPX4), solute carrier family 7 member 11/cystine transporter (SLC7A11/xCT), and transferrin receptor 1 (TFR-1), and attenuated renal cell apoptosis. In vitro, imperatorin treatment effectively decreased erastin-induced feroptotic cell death, restored the antioxidant enzyme levels, and mitigated lipid peroxidation as well as the expression of ferroptosis-related markers (XCT, GPX4, and p-p53) in a dose-dependent manner.

CONCLUSION

Our finding demonstrated for the first time, that imperatorin treatment holds therapeutic potential in a UUO mouse model of CKD and inhibits the erastin-induced oxidative stress, ferroptosis, and subsequent lipid peroxidation in vitro. This highlights the potential of imperatorin as a future therapeutic target for ferroptosis to improve the progression of CKD.

PRDM16 suppresses ferroptosis to protect against sepsis-associated acute kidney injury by targeting the NRF2/GPX4 axis

Acute kidney injury (AKI) constitutes a significant public health issue. Sepsis accounts for over 50 % of AKI cases in the ICU. Recent findings from our research indicated that the PRD1-BF1-RIZ1 homeodomain protein 16 (PRDM16) inhibited the progression of diabetic kidney disease (DKD). However, its precise role and regulatory mechanism in sepsis-induced AKI remain obscure. This study reveals that lipopolysaccharide (LPS) and cecum ligation and puncture (CLP) instigated PRDM16 expression in Boston University mouse proximal tubule (BUMPT) cells and mouse kidneys, respectively. Functionally, PRDM16 curtailed LPS-induced ferroptosis. Mechanistically, PRDM16 associates with the promoter regions of nuclear factor-erythroid 2-related factor-2 (NRF2) and augments its expression, subsequently enhancing glutathione peroxidase 4 (GPX4) expression. Additionally, PRDM16 directly engages with the promoter regions of GPX4, stimulating its expression. Notably, these observations were corroborated in human renal tubular epithelial (HK-2) cells. Furthermore, the ablation of PRDM16 from kidney proximal tubules in mice inhibited NRF2 and GPX4 expression, leading to decreased glutathione (GSH)/oxidized glutathione (GSSG) ratio, increased Fe2+ and reactive oxygen species (ROS) production, exacerbated ferroptosis, and AKI progression. Conversely, PRDM16 knock-in exhibited the opposite effects. Ultimately, adenovirus (ADV)-PRDM16 plasmid or poly (lactide-glycolide acid) (PLGA)-encapsulated formononetin not only mitigated sepsis-induced AKI but also alleviated liver, cardiac, and lung injury. In summary, PRDM16 inhibits ferroptosis via the NRF2/GPX4 axis or GPX4 to prevent sepsis-induced multi-organ injury, including AKI. PLGA-encapsulated formononetin presents a promising therapeutic approach.

Ferroptosis: mechanisms and therapeutic targets

Ferroptosis is a nonapoptotic form of cell death characterized by iron-dependent lipid peroxidation in membrane phospholipids. Since its identification in 2012, extensive research has unveiled its involvement in the pathophysiology of numerous diseases, including cancers, neurodegenerative disorders, organ injuries, infectious diseases, autoimmune conditions, metabolic disorders, and skin diseases. Oxidizable lipids, overload iron, and compromised antioxidant systems are known as critical prerequisites for driving overwhelming lipid peroxidation, ultimately leading to plasma membrane rupture and ferroptotic cell death. However, the precise regulatory networks governing ferroptosis and ferroptosis-targeted therapy in these diseases remain largely undefined, hindering the development of pharmacological agonists and antagonists. In this review, we first elucidate core mechanisms of ferroptosis and summarize its epigenetic modifications (e.g., histone modifications, DNA methylation, noncoding RNAs, and N6-methyladenosine modification) and nonepigenetic modifications (e.g., genetic mutations, transcriptional regulation, and posttranslational modifications). We then discuss the association between ferroptosis and disease pathogenesis and explore therapeutic approaches for targeting ferroptosis. We also introduce potential clinical monitoring strategies for ferroptosis. Finally, we put forward several unresolved issues in which progress is needed to better understand ferroptosis. We hope this review will offer promise for the clinical application of ferroptosis-targeted therapies in the context of human health and disease.

An In Vitro Strategy to Evaluate Ketoprofen Phototoxicity at the Molecular and Cellular Levels

Phototoxicity is a significant problem that occurs in a large part of the population and is often caused by commonly used pharmaceuticals, including over-the-counter drugs. Therefore, testing drugs with photosensitizing potential is very important. The aim of this study is to analyze the cytotoxicity and phototoxicity of ketoprofen towards human melanocytes and fibroblasts in three different treatment schemes in order to optimize the study. Cytometric tests (studies of viability, proliferation, intracellular thiol levels, mitochondrial potential, cell cycle, and DNA fragmentation), Western blot analysis (cytochrome c and p44/p42 protein levels), and confocal microscopy imaging were performed to assess the impact of the developed treatments on skin cells. Research on experimental schemes may help reduce or eliminate the risk of phototoxic reactions. In the case of ketoprofen, we found that the strongest phototoxic potential was exhibited in the treatment where the drug was present in the solution during the irradiation of cells, both pigmented and non-pigmented cells. These results indicate that the greatest risk of photosensitivity reactions related to ketoprofen occurs after direct contact with the drug and UV exposure.

Association between iron metabolism and acute kidney injury in cardiac surgery with cardiopulmonary bypass: a retrospective analysis from two datasets

OBJECTIVE

We sought to explore the linear or nonlinear relationship between preoperative iron metabolism and acute kidney injury following cardiac surgery (CSA-AKI) with cardiopulmonary bypass (CPB).

METHODS

Patients who underwent cardiac surgery with CPB between December 2018 and April 2021 were retrospectively collected from Fuwai Hospital and Medical Information Mart for Intensive Cared dataset (MIMIC-IV). The measurements of iron metabolism included serum iron (SI), serum ferritin (SF), transferrin (TRF), transferrin saturation (TS), and total iron binding capacity (TIBC). Logistic regression and restricted cubic spline (RCS) were used for linear and nonlinear analysis. The primary outcome was postoperative AKI with 48 h after cardiac surgery.

RESULTS

Of 10,639 patients screened (2420 in Fuwai Hospital and 8219 in MIMIC-IV dataset),1488 eligible patients were enrolled for the final analysis (Fuwai Hospital: n = 744, MIMIC-IV: n = 744).The incidence of AKI was 25.7% and 56.5%, respectively. Logistic regression showed that the levels of TRF (odds ratio (OR) = 1.53,95%CI:1.01-2.14, p = 0.012) and TIBC (OR = 1.05,95%CI:1.02-1.07, p < 0.001) were independent risk factor for AKI. Moreover, in the spline models adjusted with age (median:56), female, and history of diabetes, a significant statistical difference was observed between SI, SF, TRF, TS, TIBC (p for nonlinear < 0.05) and AKI in the Fuwai Hospital dataset. Additionally, the levels of SI (p for nonlinear 0.0364),SF (p for nonlinear 0.0461) were also in non-linear relationship with AKI in the MIMIC-IV dataset.

CONCLUSION

Iron metabolism markers (SI, SF, TS, TRF, and TIBC) displayed a nonlinear relationship with AKI by the RCS model (adjusted by age, gender, and history of diabetes). Notably, the MIMIC-IV dataset, which includes elderly patients, also demonstrated a nonlinear relationship between SI, SF and AKI. These findings highlight the potential therapeutic value of targeting proteins related to iron metabolism in patients with AKI.

CLINICAL TRIAL NUMBER

Not applicable.

Fullerenols as efficient ferroptosis inhibitor by targeting lipid peroxidation for preventing drug-induced acute kidney injury

Acute kidney injury (AKI) is characterized by rapid and significant deterioration of renal function over a short duration with high mortality. However, the intricate pathophysiological mechanisms underlying AKI have hindered the development of effective therapeutic strategies. Recent research has highlighted the crucial role of ferroptosis in the pathogenesis of AKI and has identified it as a promising therapeutic target. Herein, we investigated the prophylactic efficacy of fullerenol nanoparticles, renowned for their broad-spectrum free radical scavenging capabilities and favorable biocompatibility, in preventing and mitigating ferroptosis-mediated cisplatin-induced AKI. Our findings demonstrate the remarkable potential of fullerenols in mitigating AKI. Specifically, fullerenols exert their protective effects primarily by suppressing renal lipid peroxidation and ferrous iron accumulation, which are two defining hallmarks of ferroptosis. Notably, fullerenols significantly inhibited the upregulation of key enzymes involved in the intracellular lipid peroxidation induced by cisplatin, including acyl-coA synthetase long chain family member 4 (ACSL4), arachidonate lipoxygenase 3 (ALOXE3), and cytochrome P450 oxidoreductase (POR), and enhanced antioxidant systems xc-/Glutathione (GSH)/Glutathione Peroxidase 4 (GPX4). Fullerenols also significantly suppressed the increase in mRNA expression of iron regulation-related genes and prevented the elevation of low-valent iron levels in the kidney tissue of AKI mice. Collectively, our study presents fullerenol as a promising drug candidate for the prevention of AKI in clinical settings, and provides valuable insights into the management of various ferroptosis-associated diseases.

A two-pronged approach to inhibit ferroptosis of MSCs caused by the iron overload in postmenopausal osteoporosis and promote osseointegration of titanium implant

Postmenopausal osteoporosis (PMOP) is a prevalent condition among elderly women. After menopause, women exhibit decreased iron excretion, which is prone to osteoporosis. To design a specific titanium implant for PMOP, we first analyze miRNAs and DNA characteristics of postmenopausal patients with and without osteoporosis. The results indicate that iron overload disrupts iron homeostasis in the pathogenesis of PMOP. Further experiments confirm that iron overload can cause lipid peroxidation and ferroptosis of MSCs, thus breaking bone homeostasis. Based on the findings above, we have designed a novel Ti implant coated with nanospheres of caffeic acid (CA) and deferoxamine (DFO). CA can bind on the Ti surface through the two adjacent phenolic hydroxyls and polymerize into polycaffeic acid (PCA) dimer, as well as the PCA nanospheres with the repetitive 1,4-benzodioxan units. DFO was grafted with PCA through borate ester bonds. The experimental results showed that modified Ti can inhibit the ferroptosis of MSCs in the pathological environment of PMOP and promote osseointegration in two main ways. Firstly, DFO was released under high oxidative stress, chelating with excess iron and decreasing the labile iron pool in MSCs. Meanwhile, CA and DFO activated the KEAP1/NRF2/HMOX1 pathway in MSCs and reduced the level of intracellular lipid peroxidation. So, the ferroptosis of MSCs is inhibited by promoting the SLC7A11/GSH/GPX4 pathway. Furthermore, the remained CA coating on the Ti surface could reduce the extracellular oxidative stress and glutathione level. This study offers a novel inspiration for the specific design of Ti implants in the treatment of PMOP.

Mitochondrial Dysfunction-Evoked DHODH Acetylation is Involved in Renal Cell Ferroptosis during Cisplatin-Induced Acute Kidney Injury

Several studies have observed renal cell ferroptosis during cisplatin-induced acute kidney injury (AKI). However, the mechanism is not completely clear. In this study, oxidized arachidonic acid (AA) metabolites are increased in cisplatin-treated HK-2 cells. Targeted metabolomics showed that the end product of pyrimidine biosynthesis is decreased and the initiating substrate of pyrimidine biosynthesis is increased in cisplatin-treated mouse kidneys. Mitochondrial DHODH, a key enzyme for pyrimidine synthesis, and its downstream product CoQH2, are downregulated. DHODH overexpression attenuated but DHODH silence exacerbated cisplatin-induced CoQH2 depletion and lipid peroxidation. Mechanistically, renal DHODH acetylation is elevated in cisplatin-exposed mice. Mitochondrial SIRT3 is reduced in cisplatin-treated mouse kidneys and HK-2 cells. Both in vitro SIRT3 overexpression and in vivo NMN supplementation attenuated cisplatin-induced mitochondrial DHODH acetylation and renal cell ferroptosis. By contrast, Sirt3 knockout aggravated cisplatin-induced mitochondrial DHODH acetylation and renal cell ferroptosis, which can not be attenuated by NMN. Additional experiments showed that cisplatin caused mitochondrial dysfunction and SIRT3 SUMOylation. Pretreatment with mitochondria-target antioxidant MitoQ alleviated cisplatin-caused mitochondrial dysfunction, SIRT3 SUMOylation, and DHODH acetylation. MitoQ pretreatment protected against cisplatin-caused AKI and renal cell ferroptosis. Taken together, these results suggest that mitochondrial dysfunction-evoked DHODH acetylation partially contributes to renal cell ferroptosis during cisplatin-induced AKI.

Silibinin attenuates ferroptosis in acute kidney injury by targeting FTH1

Acute kidney injury (AKI) is primarily caused by renal ischemia-reperfusion injury (IRI), which is one of the most prevalent triggers. Currently, preventive and therapeutic measures remain limited. Ferroptosis plays a significant role in the pathophysiological process of IRI-induced AKI and is considered a key target for improving its outcomes. Silibinin, a polyphenolic flavonoid, possesses diverse pharmacological properties and is widely used as an effective therapeutic agent for liver diseases. Recent studies have reported that silibinin may improves kidney diseases, though the underlying mechanism remain unclear. In this study, we investigated whether silibinin protects against IRI-induced AKI and explored its mechanism of action. Our findings indicated that pretreatment with silibinin alleviated renal dysfunction, pathological damage, and inflammation in IRI-AKI mice. Furthermore, the results demonstrated that silibinin inhibited ferroptosis both in vivo and in vitro. Proteome microarrays were used to identify silibinin's target, and our results revealed that silibinin binds to FTH1. This binding affinity was confirmed through molecular docking, SPRi, CETSA, and DARTS. Additionally, co-IP assays demonstrated that silibinin disrupted the NCOA4-FTH1 interaction, inhibiting ferritinophagy. Finally, the inhibitory effects of silibinin on ferroptosis were reversed by knocking down FTH1 in vitro. In conclusion, our study shows that silibinin effectively alleviates AKI by targeting FTH1 to reduce ferroptosis, suggesting that silibinin could be developed as a potential therapeutic agent for managing and treating AKI.

The role of inflammatory response and metabolic reprogramming in sepsis-associated acute kidney injury: mechanistic insights and therapeutic potential

Sepsis represents a severe condition characterized by organ dysfunction resulting from a dysregulated host response to infection. Among the organs affected, the kidneys are particularly vulnerable, with significant functional impairment that markedly elevates mortality rates. Previous researches have highlighted that both inflammatory response dysregulation and metabolic reprogramming are crucial in the onset and progression of sepsis associated acute kidney injury (SA-AKI), making these processes potential targets for innovative therapies. This study aims to elucidate the pathophysiological mechanisms of renal injury in sepsis by perspective of inflammatory response dysregulation, with particular emphasis on pyroptosis, necroptosis, autophagy, and ferroptosis. Furthermore, it will incorporate insights into metabolic reprogramming to provide a detailed analysis of the mechanisms driving SA-AKI and explore potential targeted therapeutic strategies, providing solid theoretical framework for the development of targeted therapies for SA-AKI.

C/EBPα-mediated ACSL4-dependent ferroptosis exacerbates tubular injury in diabetic kidney disease

Diabetic kidney disease (DKD) is a prevalent and debilitating complication of diabetes characterized by progressive renal function decline and a lack of effective treatment options. Here, we investigated the role of the transcription factor CCAAT/enhancer binding protein alpha (C/EBPα) in DKD pathogenesis. Analysis of renal biopsy samples revealed increased C/EBPα expression in patients with DKD. Using RNA sequencing and proteomics, we explored the mechanisms through which the C/EBPα contributes to DKD. Our findings demonstrated that C/EBPα exacerbated tubular injury by promoting acyl-CoA synthetase long-chain family member 4 (ACSL4)-dependent ferroptosis. We identified that C/EBPα upregulated ACSL4 expression by binding to its transcription regulatory sequence (TRS), leading to elevated lipid peroxidation and ferroptosis. Furthermore, inhibition or genetic ablation of C/EBPα attenuated ferroptosis and mitigated tubular injury in DKD. These results highlighted the C/EBPα-ACSL4-ferroptosis pathway as a promising therapeutic target for DKD treatment.

Circulating proteins linked to apoptosis processes and fast development of end-stage kidney disease in diabetes

Many circulating proteins are associated with risk of ESKD, but their source and the biological pathways/disease processes they represent are unclear. Using OLINK proteomics platform, concentrations of 455 proteins were measured in plasma specimens obtained at baseline from 399 individuals with diabetes. Elevated concentrations of 46 circulating proteins were associated (P < 1 × 10-5) with development of ESKD (n = 143) during 7-15 years of follow-up. Twenty of these proteins enriched apoptosis/TNF receptor signaling pathways. A subset of 20 proteins (5-7 proteins), summarized as an apoptosis score, together with clinical variables accurately predicted risk of ESKD. Expression of genes encoding the 46 proteins in peripheral WBCs showed no difference between cells from individuals who did or did not develop ESKD. In contrast, plasma concentration of many of the 46 proteins differed by this outcome. In single-nucleus RNA-Seq analysis of kidney biopsies, the majority of genes encoding for the 20 apoptosis/TNF receptor proteins were overexpressed in injured versus healthy proximal tubule cells. Expression of these 20 genes also correlated with the overall index of apoptosis in these cells. Elevated levels of circulating proteins flagging apoptotic processes/TNF receptor signaling pathways - and likely originating from kidney cells, including injured/apoptotic proximal tubular cells - preceded the development of ESKD.

Photothermal Fe3O4 nanoparticles induced immunogenic ferroptosis for synergistic colorectal cancer therapy

Photothermal therapy (PTT) is a promising non-invasive treatment that has shown great potential in eliminating tumors. It not only induces apoptosis of cancer cells but also triggers immunogenic cell death (ICD) which could activate the immune system against cancer. However, the immunosuppressive tumor microenvironment (TIME) poses a challenge to triggering strong immune responses with a single treatment, thus limiting the therapeutic effect of cancer immunotherapy. In this study, dual-targeted nano delivery system (GOx@FeNPs) combined with αPD-L1 immune checkpoint blocker could inhibit colorectal cancer (CRC) progression by mediating PTT, ferroptosis and anti-tumor immune response. Briefly, specific tumor delivery was achieved by the cyclic arginine glycyl aspartate (cRGD) peptide and anisamide (AA)  in GOx@FeNPs which not only had a good photothermal effect to realize PTT and induce ICD, but also could deplete glutathione (GSH) and catalyze the production of reactive oxygen species (ROS) from endogenous H2O2. All these accelerated the Fenton reaction and augmented the process of PTT-induced ICD. Thus, a large amount of tumor specific antigen was released to stimulate the maturation of dendritic cells (DCs) in lymph nodes and enhance the infiltration of CD8+ T cells in tumor. At the same time, the combination with αPD-L1 has favorable synergistic effectiveness against CRC with tumor inhibition rate over 90%. Furthermore, GOx@FeNPs had good magnetic resonance imaging (MRI) capability under T2-weighting owing to the presence of Fe3+, which is favorable for integrated diagnosis and treatment systems of CRC. By constructing a dual-targeted GOx@FeNPs nanoplatform, PTT synergistically combined with ferroptosis was realized to improve the immunotherapeutic effect, providing a new approach for CRC immunotherapy.

Non-radical oxidation driven by iron-based materials without energy assistance in wastewater treatment

Chemical oxidation is extensively utilized to mitigate the impact of organic pollutants in wastewater. The non-radical oxidation driven by iron-based materials is noted for its environmental friendliness and resistance to wastewater matrix, and it is a promising approach for practical wastewater treatment. However, the complexity of heterogeneous systems and the diversity of evolutionary pathways make the mechanisms of non-radical oxidation driven by iron-based materials elusive. This work provides a systematic review of various non-radical oxidation systems driven by iron-based materials, including singlet oxygen (1O2), reactive iron species (RFeS), and interfacial electron transfer. The unique mechanisms by which iron-based materials activate different oxidants (ozone, hydrogen peroxide, persulfate, periodate, and peracetic acid) to produce non-radical oxidation are described. The roles of active sites and the unique structures of iron-based materials in facilitating non-radical oxidation are discussed. Commonly employed identification methods in wastewater treatment are compared, such as quenching, chemical probes, spectroscopy, mass spectrometry, and electrochemical testing. According to the process of iron-based materials driving non-radical oxidation to remove organic pollutants, the driving factors at different stages are summarized. Finally, challenges and countermeasures are proposed in terms of mechanism exploration, detection methods and practical applications of non-radical oxidation driven by iron-based materials. This work provides valuable insights for understanding and developing non-radical oxidation systems.

Loss of AR-regulated AFF3 contributes to prostate cancer progression and reduces ferroptosis sensitivity by downregulating ACSL4 based on single-cell sequencing analysis

Prostate cancer (PCa) is one of the most common cancers affecting the health of men worldwide. Castration-resistant prostate cancer (CRPC), the advanced and refractory phase of prostate cancer, has multiple mechanisms of resistance to androgen deprivation therapy (ADT) such as AR mutations, aberrant androgen synthase, and abnormal expression of AR-related genes. Based on the research of the AR pathway, new drugs for the treatment of CRPC have been developed in clinical practice, such as Abiraterone and enzalutamide. However, many areas in this pathway are still worth exploring. In this study, single-cell sequencing analysis was utilized to scrutinize significant genes in the androgen receptor (AR) pathway related to CRPC. Our analysis of single-cell sequencing combined with bulk-cell sequencing revealed a substantial downregulation of AR-regulated AFF3 in CRPC. Overexpression of AFF3 restricted the proliferation and migration of prostate cancer cells whilst also increasing their sensitivity towards enzalutamide, while knockdown of AFF3 had the opposite effect. To elucidate the mechanism of tumor inhibition by AFF3, we applied GSVA and GSEA to investigate the metabolic pathways related to AFF3 and revealed that AFF3 had an impact on fatty acids metabolism and ferroptosis through the regulation of ACSL4 protein expression. Based on correlation analysis and flow cytometry, we can speculate that AFF3 can impact the sensitivity of the CRPC cell lines to the ferroptosis inducer (RSL3) by regulating ACSL4. Therefore, our findings may provide new insights into the mechanisms of drug resistance in CRPC, and AFF3 may serve as a novel prognostic biomarker in prostate cancer.

Ultrasmall Nanodots with Dual Anti-Ferropototic Effect for Acute Kidney Injury Therapy

Ferroptosis is known to mediate the pathogenesis of chemotherapeutic drug-induced acute kidney injury (AKI); however, leveraging the benefits of ferroptosis-based treatments for nephroprotection remains challenging. Here, ultrasmall nanodots, denoted as FerroD, comprising the amphiphilic conjugate (tetraphenylethylene-L-serine-deferoxamine, TPE-lys-Ser-DFO (TSD)) and entrapped ferrostatin-1 are designed. After being internalized through kidney injury molecule-1-mediated endocytosis, FerroD can simultaneously remove the overloaded iron ions and eliminate the overproduction of lipid peroxides by the coordination-disassembly mechanisms, which collectively confer prominent inhibition efficiency of ferroptosis. In cisplatin (CDDP)-induced AKI mice, FerroD equipped with dual anti-ferroptotic ability can provide long-term nephroprotective effects. This study may shed new light on the design and clinical translation of therapeutics targeting ferroptosis for various ferroptosis-related kidney diseases.

A promising new approach to cancer therapy: Manipulate ferroptosis by hijacking endogenous iron

Ferroptosis, a form of regulated cell death characterized by iron-dependent phospholipid peroxidation, has emerged as a focal point in the field of cancer therapy. Compared with other cell death modes such as apoptosis and necrosis, ferroptosis exhibits many distinct characteristics in the molecular mechanisms and cell morphology, offering a promising avenue for combating cancers that are resistant to conventional therapeutic modalities. In light of the serious side effects associated with current Fenton-modulating ferroptosis therapies utilizing exogenous iron-based inorganic nanomaterials, hijacking endogenous iron could serve as an effective alternative strategy to trigger ferroptosis through targeting cellular iron regulatory mechanisms. A better understanding of the underlying iron regulatory mechanism in the process of ferroptosis has shed light on the current findings of endogenous ferroptosis-based nanomedicine strategies for cancer therapy. Here in this review article, we provide a comprehensive discussion on the regulatory network of iron metabolism and its pivotal role in ferroptosis, and present recent updates on the application of nanoparticles endowed with the ability to hijack endogenous iron for ferroptosis. We envision that the insights in the study may expedite the development and translation of endogenous ferroptosis-based nanomedicines for effective cancer treatment.

Research hotspots and future trends in lipid metabolism in chronic kidney disease: a bibliometric and visualization analysis from 2004 to 2023

Background

Disorders of lipid metabolism play a key role in the initiation and progression of chronic kidney disease (CKD). Recently, research on lipid metabolism in CKD has rapidly increased worldwide. However, comprehensive bibliometric analyses in this field are lacking. Therefore, this study aimed to evaluate publications in the field of lipid metabolism in CKD over the past 20 years based on bibliometric analysis methods to understand the important achievements, popular research topics, and emerging thematic trends.

Methods

Literature on lipid metabolism in CKD, published between 2004 and 2023, was retrieved from the Web of Science Core Collection. The VOSviewer (v.1.6.19), CiteSpace (v.6.3 R1), R language (v.4.3.2), and Bibliometrix (v.4.1.4) packages (https://www.bibliometrix.org) were used for the bibliometric analysis and visualization. Annual output, author, country, institution, journal, cited literature, co-cited literature, and keywords were also included. The citation frequency and H-index were used to evaluate quality and influence.

Results

In total, 1,285 publications in the field of lipid metabolism in CKD were identified in this study. A total of 7,615 authors from 1,885 institutions in 69 countries and regions published articles in 466 journals. Among them, China was the most productive (368 articles), and the United States had the most citations (17,880 times) and the highest H-index (75). Vaziri Nosratola D, Levi Moshe, Fornoni Alessia, Zhao Yingyong, and Merscher Sandra emerged as core authors. Levi Moshe (2,247 times) and Vaziri Nosratola D (1,969 times) were also authors of the top two most cited publications. The International Journal of Molecular Sciences and Kidney International are the most published and cited journals in this field, respectively. Cardiovascular disease (CVD) and diabetic kidney disease (DKD) have attracted significant attention in the field of lipid metabolism. Oxidative stress, inflammation, insulin resistance, autophagy, and cell death are the key research topics in this field.

Conclusion

Through bibliometric analysis, the current status and global trends in lipid metabolism in CKD were demonstrated. CVD and DKD are closely associated with the lipid metabolism of patients with CKD. Future studies should focus on effective CKD treatments using lipid-lowering targets.

The solute carrier transporters (SLCs) family in nutrient metabolism and ferroptosis

Ferroptosis is a novel form of programmed cell death caused by damage to lipid membranes due to the accumulation of lipid peroxides in response to various stimuli, such as high levels of iron, oxidative stress, metabolic disturbance, etc. Sugar, lipid, amino acid, and iron metabolism are crucial in regulating ferroptosis. The solute carrier transporters (SLCs) family, known as the "metabolic gating" of cells, is responsible for transporting intracellular nutrients and metabolites. Recent studies have highlighted the significant role of SLCs family members in ferroptosis by controlling the transport of various nutrients. Here, we summarized the function and mechanism of SLCs in ferroptosis regulated by ion, metabolic control of nutrients, and multiple signaling pathways, with a focus on SLC-related transporters that primarily transport five significant components: glucose, amino acid, lipid, trace metal ion, and other ion. Furthermore, the potential clinical applications of targeting SLCs with ferroptosis inducers for various diseases, including tumors, are discussed. Overall, this paper delves into the novel roles of the SLCs family in ferroptosis, aiming to enhance our understanding of the regulatory mechanisms of ferroptosis and identify new therapeutic targets for clinical applications.

Ferroptosis-based advanced therapies as treatment approaches for metabolic and cardiovascular diseases

Ferroptosis has attracted attention throughout the last decade because of its tremendous clinical importance. Here, we review the rapidly growing body of literature on how inhibition of ferroptosis may be harnessed for the treatment of common diseases, and we focus on metabolic and cardiovascular unmet medical needs. We introduce four classes of preclinically established ferroptosis inhibitors (ferrostatins) such as iron chelators, radical trapping agents that function in the cytoplasmic compartment, lipophilic radical trapping antioxidants and ninjurin-1 (NINJ1) specific monoclonal antibodies. In contrast to ferroptosis inducers that cause serious untoward effects such as acute kidney tubular necrosis, the side effect profile of ferrostatins appears to be limited. We also consider ferroptosis as a potential side effect itself when several advanced therapies harnessing small-interfering RNA (siRNA)-based treatment approaches are tested. Importantly, clinical trial design is impeded by the lack of an appropriate biomarker for ferroptosis detection in serum samples or tissue biopsies. However, we discuss favorable clinical scenarios suited for the design of anti-ferroptosis clinical trials to test such first-in-class compounds. We conclude that targeting ferroptosis exhibits outstanding treatment options for metabolic and cardiovascular diseases, but we have only begun to translate this knowledge into clinically relevant applications.

Renal tubular epithelial cells response to injury in acute kidney injury

Acute kidney injury (AKI) is a clinical syndrome characterized by a rapid and significant decrease in renal function that can arise from various etiologies, and is associated with high morbidity and mortality. The renal tubular epithelial cells (TECs) represent the central cell type affected by AKI, and their notable regenerative capacity is critical for the recovery of renal function in afflicted patients. The adaptive repair process initiated by surviving TECs following mild AKI facilitates full renal recovery. Conversely, when injury is severe or persistent, it allows the TECs to undergo pathological responses, abnormal adaptive repair and phenotypic transformation, which will lead to the development of renal fibrosis. Given the implications of TECs fate after injury in renal outcomes, a deeper understanding of these mechanisms is necessary to identify promising therapeutic targets and biomarkers of the repair process in the human kidney.

The complex interplay between ferroptosis and atherosclerosis

Atherosclerosis, characterized by the accumulation of plaque within the arterial walls, is an intricate cardiovascular disease that often results in severe health issues. Recent studies have emphasized the importance of ferroptosis, a controlled type of cell death dependent on iron, as a critical factor in this disease state. Ferroptosis, distinguished by its reliance on iron and the accumulation of lipid hydroperoxides, offers a unique insight into the pathology of atherosclerotic lesions. This summary encapsulates the current knowledge of the intricate role ferroptosis plays in the onset and progression of atherosclerosis. It explores the molecular processes through which lipid peroxidation and iron metabolism contribute to the development of atheromatous plaques and evaluates the possibility of utilizing ferroptosis as a novel treatment approach for atherosclerosis. By illuminating the intricate relationship between ferroptosis-related processes and atherosclerosis, this review paves the way for future clinical applications and personalized medicine approaches aimed at alleviating the effects of atherosclerosis.

ANKRD1 aggravates renal ischaemia‒reperfusion injury via promoting TRIM25-mediated ubiquitination of ACSL3

BACKGROUND

Renal ischaemia‒reperfusion injury (IRI) is the primary cause of acute kidney injury (AKI). To date, effective therapies for delaying renal IRI and postponing patient survival remain absent. Ankyrin repeat domain 1 (ANKRD1) has been implicated in some pathophysiologic processes, but its role in renal IRI has not been explored.

METHODS

The mouse model of IRI-AKI and in vitro model were utilised to investigate the role of ANKRD1. Immunoprecipitation-mass spectrometry was performed to identify potential ANKRD1-interacting proteins. Protein‒protein interactions and protein ubiquitination were examined using immunoprecipitation and proximity ligation assay and immunoblotting, respectively. Cell viability, damage and lipid peroxidation were evaluated using biochemical and cellular techniques.

RESULTS

First, we unveiled that ANKRD1 were significantly elevated in renal IRI models. Global knockdown of ANKRD1 in all cell types of mouse kidney by recombinant adeno-associated virus (rAAV9)-mitigated ischaemia/reperfusion-induced renal damage and failure. Silencing ANKRD1 enhanced cell viability and alleviated cell damage in human renal proximal tubule cells exposed to hypoxia reoxygenation or hydrogen peroxide, while ANKRD1 overexpression had the opposite effect. Second, we discovered that ANKRD1's detrimental function during renal IRI involves promoting lipid peroxidation and ferroptosis by directly binding to and decreasing levels of acyl-coenzyme A synthetase long-chain family member 3 (ACSL3), a key protein in lipid metabolism. Furthermore, attenuating ACSL3 in vivo through pharmaceutical approach and in vitro via RNA interference mitigated the anti-ferroptotic effect of ANKRD1 knockdown. Finally, we showed ANKRD1 facilitated post-translational degradation of ACSL3 by modulating E3 ligase tripartite motif containing 25 (TRIM25) to catalyse K63-linked ubiquitination of ACSL3, thereby amplifying lipid peroxidation and ferroptosis, exacerbating renal injury.

CONCLUSIONS

Our study revealed a previously unknown function of ANKRD1 in renal IRI. By driving ACSL3 ubiquitination and degradation, ANKRD1 aggravates ferroptosis and ultimately exacerbates IRI-AKI, underlining ANKRD1's potential as a therapeutic target for kidney IRI.

KEY POINTS/HIGHLIGHTS

Ankyrin repeat domain 1 (ANKRD1) is rapidly activated in renal ischaemia‒reperfusion injury (IRI) models in vivo and in vitro. ANKRD1 knockdown mitigates kidney damage and preserves renal function. Ferroptosis contributes to the deteriorating function of ANKRD1 in renal IRI. ANKRD1 promotes acyl-coenzyme A synthetase long-chain family member 3 (ACSL3) degradation via the ubiquitin‒proteasome pathway. The E3 ligase tripartite motif containing 25 (TRIM25) is responsible for ANKRD1-mediated ubiquitination of ACSL3.

Dyslipidemia-induced renal fibrosis related to ferroptosis and endoplasmic reticulum stress

Dyslipidemia may induce chronic kidney disease and trigger both ferroptosis and endoplasmic reticulum (ER) stress, but the instigating factors are incompletely understood. We tested the hypothesis that different models of dyslipidemia engage distinct kidney injury mechanisms. Wild-type (WT) or proprotein-convertase subtilisin/kexin type-9 (PCSK9)-gain-of-function (GOF) Ossabaw pigs were fed with a 6-month normal diet (ND) or high-fat diet (HFD) (n = 5-6 each). Renal function and fat deposition were studied in vivo using CT, and blood and kidney tissue studied ex-vivo for lipid profile, systemic and renal vein FFAs levels, and renal injury mechanisms including lipid peroxidation, ferroptosis, and ER stress. Compared with WT-ND pigs, both HFD and PCSK9-GOF elevated triglyceride levels, which were highest in WT-HFD, whereas total and LDL cholesterol levels rose only in PCSK9-GOF pigs, particularly in PCSK9-GOF/HFD. The HFD groups had worse kidney function than the ND groups. The WT-HFD kidneys retained more FFA than other groups, but all kidneys developed fibrosis. Furthermore, HFD-induced ferroptosis in WT-HFD indicated by increased free iron, lipid peroxidation, and decreased glutathione peroxidase-4 mRNA expression, while PCSK9-GOF induced ER stress with upregulated GRP94 and CHOP protein expression. In vitro, pig kidney epithelial cells treated with palmitic acid and oxidized LDL to mimic HFD and PCSK9-GOF showed similar trends to those observed in vivo. Taken together, HFD-induced hypertriglyceridemia promotes renal FFA retention and ferroptosis, whereas PCSK9-GOF-induced hypercholesterolemia elicits ER stress, both resulting in renal fibrosis. These observations suggest different targets for preventing and treating renal fibrosis in subjects with specific types of dyslipidemia.

The significance of ferroptosis in renal diseases and its therapeutic potential

Kidney diseases are significant global public health concern, with increasing prevalence and substantial economic impact. Developing novel therapeutic approaches are essential for delaying disease progression and improving patient quality of life. Cell death signifying the termination of cellular life, could facilitate appropriate bodily development and internal homeostasis. Recently, regulated cell death (RCD) forms such as ferroptosis, characterized by iron-dependent lipid peroxidation, has garnered attention in diverse renal diseases and other pathological conditions. This review offers a comprehensive examination of ferroptosis, encompassing an analysis of the involvement of iron and lipid metabolism, the System Xc - /glutathione/glutathione peroxidase 4 signaling, and additional associated pathways. Meanwhile, the review delves into the potential of targeting ferroptosis as a therapeutic approach in the management of acute kidney injury (AKI), chronic kidney disease (CKD), diabetic nephropathy, and renal tumors. Furthermore, it emphasizes the significance of ferroptosis in the transition from AKI to CKD and further accentuates the potential for repurposing drug and utilizing traditional medicine in targeting ferroptosis-related pathways for clinical applications. The integrated review provides valuable insights into the role of ferroptosis in kidney diseases and highlights the potential for targeting ferroptosis as a therapeutic strategy.

Human adipose mesenchymal stem cell-derived exosomes alleviate fibrosis by restraining ferroptosis in keloids

Background

Keloid is a fibroproliferative disease with unsatisfactory therapeutic effects and a high recurrence rate. exosomes produced by adipose-derived mesenchymal stem cells (ADSC-Exos) have attracted significant interest due to their ability to treat fibrosis. However, the molecular mechanisms of ADSC-Exos in keloids remain inconclusive.

Objective

Our study revealed the relationship between ferroptosis and fibrosis in keloids. Subsequently, this study aimed to explore further the anti-fibrotic effect of ADSC-Exos on keloids through ferroptosis and the potential underlying mechanisms.

Methods

To investigate the impact of ferroptosis on keloid fibrosis, Erastin and ferrostatin-1 (fer-1) were utilized to treat keloid fibroblast. Keloid keloids treated with Erastin and fer-1 were cocultured with ADSC-Exos to validate the impact of ferroptosis on the effect of ADSC-Exos on keloid anti-ferrotic protein, peroxidase 4 (GPX4) and anti-fibrotic effects in vivo and in vitro by Western blot, as well as variations in iron metabolite expression, malondialdehyde (MDA), liposomal peroxidation (LPO) and glutathione (GSH) were analyzed. The effect of solute carrier family 7-member 11 (SLC7A11) silencing on ADSC-Exo-treated keloid fibroblast was investigated.

Results

Iron metabolite dysregulation was validated in keloids. Fibrosis progression is enhanced by Erastin-induced ferroptosis. The anti-fibrotic effects of ADSC-Exos and fer-1 are related to their ability to prevent iron metabolism. ADSC-Exos effectively suppressed keloid fibrosis progression and increased GSH and GPX4 gene expression. Additionally, the use of Erastin limits the effect of ADSC-Exos in keloids. Furthermore, the effect of ADSC-Exos on keloids was associated with SLC7A11-GPX4 signaling pathway.

Conclusion

We demonstrated a new potential mechanism by which anti-ferroptosis inhibits the progression of keloid fibrosis and identified an ADSC-Exo-based keloid therapeutic strategy. Resisting the occurrence of ferroptosis and the existence of the SLC7A11-GPX4 signaling pathway might serve as a target for ADSC-Exos.

Reactive oxygen species regulation by NCF1 governs ferroptosis susceptibility of Kupffer cells to MASH

Impaired self-renewal of Kupffer cells (KCs) leads to inflammation in metabolic dysfunction-associated steatohepatitis (MASH). Here, we identify neutrophil cytosolic factor 1 (NCF1) as a critical regulator of iron homeostasis in KCs. NCF1 is upregulated in liver macrophages and dendritic cells in humans with metabolic dysfunction-associated steatotic liver disease and in MASH mice. Macrophage NCF1, but not dendritic cell NCF1, triggers KC iron overload, ferroptosis, and monocyte-derived macrophage infiltration, thus aggravating MASH progression. Mechanistically, elevated oxidized phospholipids induced by macrophage NCF1 promote Toll-like receptor (TLR4)-dependent hepatocyte hepcidin production, leading to increased KC iron deposition and subsequent KC ferroptosis. Importantly, the human low-functional polymorphic variant NCF190H alleviates KC ferroptosis and MASH in mice. In conclusion, macrophage NCF1 impairs iron homeostasis in KCs by oxidizing phospholipids, triggering hepatocyte hepcidin release and KC ferroptosis in MASH, highlighting NCF1 as a therapeutic target for improving KC fate and limiting MASH progression.

Human umbilical cord mesenchymal stem cells alleviate chemotherapy-induced premature ovarian insufficiency mouse model by suppressing ferritinophagy-mediated ferroptosis in granulosa cells

Primary ovarian insufficiency (POI) in younger women (under 40) manifests as irregular periods, high follicle-stimulating hormone (FSH), and low estradiol (E2), often triggered by chemotherapy. Though mesenchymal stem cell (MSC) therapy shows promise in treating POI, its exact mechanism remains unclear. This study reveals that human umbilical cord-derived MSCs (hUC-MSCs) can protect ovarian granulosa cells (GCs) from cyclophosphamide (CTX)-induced ferroptosis, a form of cell death driven by iron accumulation. CTX, commonly used to induce POI animal model, triggered ferroptosis in GCs, while hUC-MSCs treatment mitigated this effect, both in vivo and in vitro. Further investigations using ferroptosis and autophagy inhibitors suggest that hUC-MSCs act by suppressing ferroptosis in GCs. Interestingly, hUC-MSCs activate a protective antioxidant pathway in GCs via NRF2, a stress-response regulator. Overall, our findings suggest that hUC-MSCs improve ovarian function in CTX-induced POI by reducing ferroptosis in GCs. This study not only clarifies the mechanism behind the benefits of hUC-MSCs but also strengthens the case for their clinical use in treating POI. Additionally, it opens up a new avenue for protecting ovaries from chemotherapy-induced damage by regulating ferroptosis.

Targeting novel regulated cell death: Ferroptosis, pyroptosis and necroptosis in anti-PD-1/PD-L1 cancer immunotherapy

Chemotherapy, radiotherapy, and immunotherapy represent key tumour treatment strategies. Notably, immune checkpoint inhibitors (ICIs), particularly anti-programmed cell death 1 (PD1) and anti-programmed cell death ligand 1 (PD-L1), have shown clinical efficacy in clinical tumour immunotherapy. However, the limited effectiveness of ICIs is evident due to many cancers exhibiting poor responses to this treatment. An emerging avenue involves triggering non-apoptotic regulated cell death (RCD), a significant mechanism driving cancer cell death in diverse cancer treatments. Recent research demonstrates that combining RCD inducers with ICIs significantly enhances their antitumor efficacy across various cancer types. The use of anti-PD-1/PD-L1 immunotherapy activates CD8+ T cells, prompting the initiation of novel RCD forms, such as ferroptosis, pyroptosis, and necroptosis. However, the functions and mechanisms of non-apoptotic RCD in anti-PD1/PD-L1 therapy remain insufficiently explored. This review summarises the emerging roles of ferroptosis, pyroptosis, and necroptosis in anti-PD1/PD-L1 immunotherapy. It emphasises the synergy between nanomaterials and PD-1/PD-L1 inhibitors to induce non-apoptotic RCD in different cancer types. Furthermore, targeting cell death signalling pathways in combination with anti-PD1/PD-L1 therapies holds promise as a prospective immunotherapy strategy for tumour treatment.

MOFs-Based Magnetic Nanozyme to Boost Cascade ROS Accumulation for Augmented Tumor Ferroptosis

The emerging cell death modality of ferroptosis has garnered increasing attention for antitumor treatment but still suffers from low therapeutic efficacy. A metal-organic frameworks (MOFs)-based magnetic nanozyme (PZFH) comprising porphyrin-based Zr-MOF (PCN) on zinc ferrite (ZF) nanoparticles modified with hyaluronic acid, delivering excellent magnetophotonic response for efficient ferroptosis, is reported here. PZFH shows multienzyme-like cascade activity encompassing a photon-triggered oxidase-like catalysis to generate O2 -, which is converted to H2O2 by superoxide dismutase-like activity and subsequent ·OH by magneto-promoted peroxidase (POD) behavior. Newly formed Fe─N coordination and increased Fe2+/Fe3+ levels in the PZFH contribute to the enhanced POD activity, which is further enhanced by accelerated surface electron transfer when exposure to alternated magnetic field. Accumulation of lipid peroxides is eventually accomplished through the conversion of ·OH radicals and singlet oxygen (1O2) produced through laser irradiation. When combined with the depletion of inhibition of glutathione and glutathione peroxidase 4, PZFH exhibits significantly enhanced ferroptosis in tumor-bearing mice, offering insights into nanomedicine for ferroptosis and holding great promise in clinical antitumor therapies.

Novel Carbon Quantum Dots Precisely Trigger Ferroptosis in Cancer Cells through Antioxidant Inhibition Synergistic Nanocatalytic Activity

High levels of glutathione (GSH) are an important characteristic of malignant tumors and a significant cause of ineffective treatment and multidrug resistance. Although reactive oxygen species (ROS) therapy has been shown to induce tumor cell death, the strong clearance effect of GSH on ROS significantly reduces its therapeutic efficacy. Therefore, there is a need to develop new strategies for targeting GSH. In this study, novel carbon quantum dots derived from gentamycin (GM-CQDs) were designed and synthesized. On the basis of the results obtained, GM-CQDs contain sp2 and sp3 carbon atoms as well as nitrogen oxygen groups, which decrease the intracellular levels of GSH by downregulating SLC7A11, thereby disrupting redox balance, mediating lipid peroxidation, and inducing ferroptosis. Transcriptome analysis demonstrated that GM-CQDs downregulated the expression of molecules related to GSH metabolism while significantly increasing the expression of molecules related to ferroptosis. The in vivo results showed that the GM-CQDs exhibited excellent antitumor activity and immune activation ability. Furthermore, because of their ideal biological safety, GM-CQDs are highly promising for application as drugs targeting GSH in the treatment of malignant tumors.

Habitual Iron Supplementation Associated with Elevated Risk of Chronic Kidney Disease in Individuals with Antihypertensive Medication

The aim of this study was to examine the effects of habitual iron supplementation on the risk of CKD in individuals with different hypertensive statuses and antihypertension treatment statuses. We included a total of 427,939 participants in the UK Biobank study, who were free of CKD and with complete data on blood pressure at baseline. Cox proportional hazards regression models were used to examine the adjusted hazard ratios of habitual iron supplementation for CKD risk. After multivariable adjustment, habitual iron supplementation was found to be associated with a significantly higher risk of incident CKD in hypertensive participants (HR 1.12, 95% CI 1.02 to 1.22), particularly in those using antihypertensive medication (HR 1.21, 95% CI 1.08 to 1.35). In contrast, there was no significant association either in normotensive participants (HR 1.06, 95% CI 0.94 to 1.20) or in hypertensive participants without antihypertensive medication (HR 1.02, 95% CI 0.90 to 1.17). Consistently, significant multiplicative and additive interactions were observed between habitual iron supplementation and antihypertensive medication on the risk of incident CKD (p all interaction < 0.05). In conclusion, habitual iron supplementation was related to a higher risk of incident CKD among hypertensive patients, the association might be driven by the use of antihypertensive medication.

A homologous membrane-camouflaged self-assembled nanodrug for synergistic antitumor therapy

Limited success has been achieved in ferroptosis-induced cancer treatment due to the challenges related to low production of toxic reactive oxygen species (ROS) and inherent ROS resistance in cancer cells. To address this issue, a self-assembled nanodrug have been investigated that enhances ferroptosis therapy by increasing ROS production and reducing ROS inhibition. The nanodrug is constructed by allowing doxorubicin (DOX) to interact with Fe2+ through coordination interactions, forming a stable DOX-Fe2+ chelate, and this chelate further interacts with sorafenib (SRF), resulting in a stable and uniform nanoparticle. In tumor cells, overexpressed glutathione (GSH) triggers the disassembly of nanodrug, thereby activating the drug release. Interestingly, the released DOX not only activates nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) to produce abundant H2O2 production for enhanced ROS production, but also acts as a chemotherapeutics agent, synergizing with ferroptosis. To enhance tumor selectivity and improve the blood clearance, the nanodrug is coated with a related cancer cell membrane, which enhances the selective inhibition of tumor growth and metastasis in a B16F10 mice model. Our findings provide valuable insights into the rational design of self-assembled nanodrug for enhanced ferroptosis therapy in cancer treatment. STATEMENT OF SIGNIFICANCE: Ferroptosis is a non-apoptotic form of cell death induced by the iron-regulated lipid peroxides (LPOs), offering a promising potential for effective and safe anti-cancer treatment. However, two significant challenges hinder its clinical application: 1) The easily oxidized nature of Fe2+ and the low concentration of H2O2 leads to a low efficiency of intracellular Fenton reaction, resulting in poor therapeutic efficacy; 2) The instinctive ROS resistance of cancer cells induce drug resistance. Therefore, we developed a simple and high-efficiency nanodrug composed of self-assembling by Fe2+ sources, H2O2 inducer and ROS resistance inhibitors. This nanodrug can effectively deliver the Fe2+ sources into tumor tissue, enhance intracellular concentration of H2O2, and reduce ROS resistance, achieving a high-efficiency, precise and safe ferroptosis therapy.