Liproxstatin-1 Alleviates Lung Transplantation-induced Cold Ischemia-Reperfusion Injury by Inhibiting Ferroptosis

Single-cell RNA Sequencing of Pig Lung Transplantation Reveals Macrophage Ferroptosis in Lung IschemiaReperfusion Injury

Primary graft dysfunction (PGD), which is caused primarily by ischemia-reperfusion injury (IRI), is a major obstacle in lung transplantation. Here, we developed an orthotopic, single-lung transplant pig model to simulate prolonged cold IRI. After 24 hours of cold ischemia and 8 hours of warm reperfusion, the transplanted lung exhibited severe allograft injury. Subsequent single-cell RNA sequencing (scRNA-seq) revealed significant changes in alveolar macrophages after IRI, with prominently enriched ferroptosis pathways. Transmission electron microscopy (TEM) confirmed characteristic ferroptosis changes in lung macrophages, and decreased GPX4 expression in macrophages indicated increased susceptibility to ferroptosis. Overall, our pig orthotopic left lung transplant model effectively simulates IRI after transplantation, which offers a valuable platform for more detailed investigations of early reperfusion injury to pulmonary grafts. Moreover, we preliminarily demonstrated the importance of macrophage ferroptosis in IRI, suggesting that inhibiting macrophage ferroptosis may be a promising therapeutic strategy for lung IRI.

Ferroptosis: when metabolism meets cell death

We present here a comprehensive update on recent advancements in the field of ferroptosis, with a particular emphasis on its metabolic underpinnings and physiological impacts. After briefly introducing landmark studies that have helped to shape the concept of ferroptosis as a distinct form of cell death, we critically evaluate the key metabolic determinants involved in its regulation. These include the metabolism of essential trace elements such as selenium and iron; amino acids such as cyst(e)ine, methionine, glutamine/glutamate, and tryptophan; and carbohydrates, covering glycolysis, the citric acid cycle, the electron transport chain, and the pentose phosphate pathway. We also delve into the mevalonate pathway and subsequent cholesterol biosynthesis, including intermediate metabolites like dimethylallyl pyrophosphate, squalene, coenzyme Q (CoQ), vitamin K, and 7-dehydrocholesterol, as well as fatty acid and phospholipid metabolism, including the biosynthesis and remodeling of ester and ether phospholipids and lipid peroxidation. Next, we highlight major ferroptosis surveillance systems, specifically the cyst(e)ine/glutathione/glutathione peroxidase 4 axis, the NAD(P)H/ferroptosis suppressor protein 1/CoQ/vitamin K system, and the guanosine triphosphate cyclohydrolase 1/tetrahydrobiopterin/dihydrofolate reductase axis. We also discuss other potential anti- and proferroptotic systems, including glutathione S-transferase P1, peroxiredoxin 6, dihydroorotate dehydrogenase, glycerol-3-phosphate dehydrogenase 2, vitamin K epoxide reductase complex subunit 1 like 1, nitric oxide, and acyl-CoA synthetase long-chain family member 4. Finally, we explore ferroptosis's physiological roles in aging, tumor suppression, and infection control, its pathological implications in tissue ischemia-reperfusion injury and neurodegeneration, and its potential therapeutic applications in cancer treatment. Existing drugs and compounds that may regulate ferroptosis in vivo are enumerated.

Warm-ischemia and cold storage induced modulation of ferroptosis observed in human hearts donated after circulatory death and brain death

We investigated ferroptosis, a type of programmed cell death mechanism, in human hearts donated after brain death (DBD) and those donated after circulatory death (DCD), focusing on warm ischemia time (WIT) and cold storage. A total of 24 hearts were procured, with six from the DBD group and 18 from the DCD group. The DCD group was divided into three subgroups, each containing six hearts, based on different WITs of 20, 40, and 60 min. All procured hearts were placed in cold storage for up to 6 h. Left ventricular biopsies were performed at 0, 2, 4, and 6 h. We measured ferroptosis regulators [glutathione peroxidase 4 (GPX4), acyl-CoA synthetase long chain family member 4 (ACSL4), and transferrin receptor], iron content (Fe2+ and Fe3+), and lipid peroxidation (malondialdehyde, MDA) in the cardiac tissue. Modulation of ferroptosis was observed in both DBD and DCD hearts. Warm ischemia injury increased myocardial vulnerability to ferroptotic cell death. For DBD hearts, up to 6 h of cold storage increases cardiac levels of MDA, iron content, and ACSL4, thereby increasing vulnerability to ferroptotic cell death. In contrast, for DCD hearts with a WIT of 40 min or more, warm ischemia injury was identified as the primary factor contributing to increased myocardial susceptibility to ferroptotic cell death. Ferroptosis may serve as a promising target to optimize cold preservation for DBD hearts. For DCD hearts, strategies to inhibit ferroptosis should focus on the early warm ischemia phase to assess donor heart quality and suitability for transplantation.NEW & NOTEWORTHY The first human heart research explored the effects of ischemia on the myocardial ferroptotic cell death mechanism. Prolonged cold storage increases the susceptibility of DBD hearts to ferroptotic cell death. In contrast, warm ischemic injury appears to be the main factor leading to the vulnerability of DCD heart ferroptosis. Targeting ferroptosis could be beneficial in optimizing cold preservation for DBD hearts. However, for DCD hearts, interventions should focus on the early phase of warm ischemia.

L-Alanyl-L-Glutamine Alleviated Ischemia-Reperfusion Injury and Primary Graft Dysfunction in Rat Lung Transplants

BACKGROUND

Concern of ischemia-reperfusion injury reduces utilization of donor lungs. We hypothesized adding L-alanyl-L-glutamine (L-AG) to preservation solution may protect donor lungs from ischemia-reperfusion injury through its multiple cytoprotective effects.

METHODS

A lung transplantation cell culture model was used on human lung epithelial cells and pulmonary microvascular endothelial cells, and the effects of adding different concentrations of L-AG on basic cellular function were tested. Rat donor lungs were preserved at 4 °C with 8 mmol/L L-AG for 12 h followed by 4 h reperfusion or monitored for 3 d. Lung function, lung histology, inflammation, and cell death biomarker were tested. Computerized tomography scan was used and metabolomic analysis was performed on lung tissues.

RESULTS

Cold preservation with L-AG improved cell viability and inhibited apoptosis in cell culture. Rat donor lungs treated with L-AG during cold storage showed decreased peak airway pressure, higher dynamic compliance and oxygenation ability, reduced lung injury, apoptosis, and oxidative stress during reperfusion. L-AG treatment significantly changed 130 metabolites during reperfusion, with enhanced amino acid biosynthesis and tricarboxylic acid cycle. Furthermore, cold storage with L-AG decreased primary graft dysfunction grade, improved oxygenation, reduced pulmonary atelectasis, sign of infection, and pneumothorax in a rat left lung transplant 3-d survival model.

CONCLUSIONS

Adding L-AG to cold preservation solution reduced lung injury and alleviated primary graft dysfunction by inhibiting inflammation, oxidative stress, and cell death with modified metabolic activities.

Integrated Analysis and Validation of Ferroptosis-Related Genes Associated with Ischemia/Reperfusion Injury in Lung Transplantation

Background

Lung transplantation is the only effective therapeutic option for patients with end-stage lung disease. However, ischemia/reperfusion injury (IRI) during transplantation is a leading cause of primary graft dysfunction (PGD). Ferroptosis, a form of iron-dependent cell death driven by lipid peroxidation, has been implicated in IRI across various organs. This study aims to explore the role of ferroptosis in lung transplantation-related ischemia/reperfusion injury and to identify its potential molecular mechanisms through bioinformatics analysis.

Methods

Transcriptome data from lung transplant patients were obtained from the Gene Expression Omnibus (GEO) database. Ferroptosis-related differentially expressed genes (FRGs) were identified by analyzing gene expression profiles before and after reperfusion. Weighted gene co-expression network analysis (WGCNA) was used to identify module genes, and overlapping genes were further analyzed using two machine learning algorithms. The CIBERSORT algorithm was applied to assess immune cell infiltration, while Mendelian randomization (MR) analysis was used to investigate causal relationships between candidate genes and PGD. Finally, Consensus clustering based on FRGs was performed to identify subtypes.

Results

We identified four candidate genes associated with ferroptosis during lung reperfusion: tumor necrosis factor alpha-induced protein 3 (TNFAIP3), C-X-C motif chemokine ligand 2 (CXCL2), neural precursor cell expressed developmentally down-regulated 4-like (NEDD4L), and sestrin 2 (SESN2). These genes were closely associated with immune cell infiltration. MR analysis suggested that SESN2 might play a protective role against PGD. Additionally, consensus clustering revealed distinct immune infiltration patterns across subtypes, providing insights for personalized therapeutic approaches to lung ischemia/reperfusion injury (LIRI).

Conclusion

This study highlights TNFAIP3, CXCL2, NEDD4L, and SESN2 as candidate genes associated with ferroptosis during LIRI, with SESN2 potentially protecting against PGD. These findings offer promising therapeutic targets for preventing LIRI and improving outcomes in lung transplantation.

Ferroptosis in organ ischemia-reperfusion injuries: recent advancements and strategies

Ferroptosis is a newly discovered type of regulated cell death participated in multiple diseases. Different from other classical cell death programs such as necrosis and apoptosis, ferroptosis involving iron-catalyzed lipid peroxidation is characterized by Fe2+ accumulation and mitochondria alterations. The phenomenon of oxidative stress following organ ischemia-reperfusion (I/R) has recently garnered attention for its connection to the onset of ferroptosis and subsequent reperfusion injuries. This article provides a comprehensive overview underlying the mechanisms of ferroptosis, with a further focus on the latest research progress regarding interference with ferroptotic pathways in organ I/R injuries, such as intestine, lung, heart, kidney, liver, and brain. Understanding the links between ferroptosis and I/R injury may inform potential therapeutic strategies and targeted agents.

Neutrophil PPIF exacerbates lung ischemia-reperfusion injury after lung transplantation by promoting calcium overload-induced neutrophil extracellular traps formation

Lung ischemia-reperfusion (I/R) injury is the main risk factor for primary graft dysfunction and patient death after lung transplantation (LTx). It is widely accepted that the main pathological mechanism of lung I/R injury are calcium overload, oxygen free radical explosion and neutrophil-mediated damage, which leading to the lack of effective treatment options. The aim of this study was to further explore the mechanisms of lung I/R injury after LTx and to provide potential therapeutic strategies. Our bioinformatics analysis revealed that the neutrophil extracellular traps (NETs) formation was closely involved in lung I/R injury after LTx, which was accompanied by up-regulation of peptidylprolyl isomerase F (PPIF) and peptidyl arginine deiminase 4 (PADI4). We further established an orthotopic LTx mouse model to simulate lung I/R injury in vivo, and found that PPIF and PADI4 inhibitors effectively reduced neutrophil infiltration, NETs formation, inflammatory response, and lung I/R injury. In the neutrophil model induced by HL-60 cell line in vitro, we found that PPIF inhibitor cyclosporin A (Cys A) better alleviated calcium overload induced inflammatory response, reactive oxygen species content and NETs formation. Further study demonstrated that interfering with neutrophil PPIF protected mitochondrial function by alleviating store-operated calcium entry (SOCE) during calcium overload and played the above positive role. On this basis, we found that the reduction of calcium content in neutrophils was accompanied by the inhibition of calcineurin (CN) and nuclear factor of activated T cells (NFAT). In conclusion, our findings suggested that neutrophil PPIF could serve as a novel biomarker and potential therapeutic target of lung I/R injury after LTx, which provided new clues for its treatment by inhibiting calcium overload-induced NETs formation.

Wogonin Alleviates DCD Liver Ischemia/Reperfusion Injury by Regulating ALOX15/iNOS-mediated Ferroptosis

BACKGROUND

Donation after circulatory death livers are more susceptible to ischemia/reperfusion injury (IRI) because of a longer period of warm ischemia. Growing evidence now suggests that ferroptosis plays a key regulatory role in the development of IRI, so targeting ferroptosis may be an effective strategy to alleviate IRI in liver transplantation (LT).

METHODS

Using donation after circulatory death LT models in rats and oxygen-glucose deprivation/reoxygenation (OGD/R) models in BRL-3A cells, we tested the effect of the Chinese medicine monomer wogonin on liver IRI and explored the specific mechanism.

RESULTS

Wogonin attenuated liver IRI and increased the survival rate of rats by inhibiting lipid peroxidation and ferroptosis. Mechanistically, arachidonic acid 15-lipoxygenase-1 (ALOX15) and inducible nitric oxide synthase (iNOS) were identified as potential targets of baicalein through bioinformatics analysis combined with in vivo and in vitro experiments. This result was further confirmed by molecular docking and cellular thermal shift assays. Finally, we silenced ALOX15 and iNOS in the OGD/R cell model and found that silencing ALOX15 and iNOS could reproduce the regulatory effect of wogonin and abrogate the regulatory effect of wogonin.

CONCLUSIONS

In brief, this study emphasizes that wogonin exerts a protective effect in liver IRI through the regulation of ALOX15- and iNOS-mediated ferroptosis. ALOX15 and iNOS are potential targets for intervention in IRI induced by LT, and wogonin is a drug candidate for LT patients.

Ischemia/Reperfusion Upregulates Genes Related to PANoptosis in Human Lung Transplants

BACKGROUND

Activation of multiple programmed cell death (PCD) pathways has been reported in cellular and animal studies of ischemia/reperfusion injury in lung transplantation. However, the status of these pathways in human lung transplants remains unknown. This study investigates the involvement of PCD pathways and their relationship with inflammation and signaling pathways in human lung transplants.

METHODS

Transcriptomic analysis was conducted on 54 paired human lung tissue samples at the end of cold preservation time and 2 h after reperfusion, collected between 2008 and 2011. Gene Set Enrichment Analysis (GSEA) and single-sample GSEA were used to examine the activation of genes in 6 PCD pathways. The relationships between PCD pathways and inflammation, as well as signaling pathways, were assessed via single-gene GSEA.

RESULTS

GSEA results indicated that apoptosis and necroptosis were significantly upregulated after reperfusion in human lung transplants, whereas the gene sets related to pyroptosis, ferroptosis, autophagy, and cuproptosis were not significantly upregulated. Notably, single-sample GSEA demonstrated an intricate interplay among pyroptosis, apoptosis, and necroptosis, collectively referred to as PANoptosis, which is further supported by enrichment of genes related to PANoptosome, inflammatory response, and nuclear factor-κB and interferon signaling pathways, via single-gene GSEA assays.

CONCLUSIONS

This study demonstrated the genes of PANoptosis are upregulated in human lung grafts during reperfusion. The discovery of PANoptosis as an underlying mechanism of cell death in human lung grafts implies that effective therapeutics to prevent or reduce PANoptosis may alleviate ischemia/reperfusion injury and improve clinical lung transplant outcomes.

Identification of Differentially Expressed Genes in Cold Storage-associated Kidney Transplantation

BACKGROUND

Although it is acknowledged that ischemia-reperfusion injury is the primary pathology of cold storage-associated kidney transplantation, its underlying mechanism is not well elucidated.

METHODS

To extend the understanding of molecular events and mine hub genes posttransplantation, we performed bulk RNA sequencing at different time points (24 h, day 7, and day 14) on a murine kidney transplantation model with prolonged cold storage (10 h).

RESULTS

In the present study, we showed that genes related to the regulation of apoptotic process, DNA damage response, cell cycle/proliferation, and inflammatory response were steadily elevated at 24 h and day 7. The upregulated gene profiling delicately transformed to extracellular matrix organization and fibrosis at day 14. It is prominent that metabolism-associated genes persistently took the first place among downregulated genes. The gene ontology terms of particular note to enrich are fatty acid oxidation and mitochondria energy metabolism. Correspondingly, the key enzymes of the above processes were the products of hub genes as recognized. Moreover, we highlighted the proximal tubular cell-specific increased genes at 24 h by combining the data with public RNA-Seq performed on proximal tubules. We also focused on ferroptosis-related genes and fatty acid oxidation genes to show profound gene dysregulation in kidney transplantation.

CONCLUSIONS

The comprehensive characterization of transcriptomic analysis may help provide diagnostic biomarkers and therapeutic targets in kidney transplantation.

Inhibition of ALOX12-12-HETE Alleviates Lung Ischemia-Reperfusion Injury by Reducing Endothelial Ferroptosis-Mediated Neutrophil Extracellular Trap Formation

Lung ischemia-reperfusion injury (IRI) stands as the primary culprit behind primary graft dysfunction (PGD) after lung transplantation, yet viable therapeutic options are lacking. In the present study, we used a murine hilar clamp (1 h) and reperfusion (3 h) model to study IRI. The left lung tissues were harvested for metabolomics, transcriptomics, and single-cell RNA sequencing. Metabolomics of plasma from human lung transplantation recipients was also performed. Lung histology, pulmonary function, pulmonary edema, and survival analysis were measured in mice. Integrative analysis of metabolomics and transcriptomics revealed a marked up-regulation of arachidonate 12-lipoxygenase (ALOX12) and its metabolite 12-hydroxyeicosatetraenoic acid (12-HETE), which played a pivotal role in promoting ferroptosis and neutrophil extracellular trap (NET) formation during lung IRI. Additionally, single-cell RNA sequencing revealed that ferroptosis predominantly occurred in pulmonary endothelial cells. Importantly, Alox12-knockout (KO) mice exhibited a notable decrease in ferroptosis, NET formation, and tissue injury. To investigate the interplay between endothelial ferroptosis and NET formation, a hypoxia/reoxygenation (HR) cell model using 2 human endothelial cell lines was established. By incubating conditioned medium from HR cell model with neutrophils, we found that the liberation of high mobility group box 1 (HMGB1) from endothelial cells undergoing ferroptosis facilitated the formation of NETs by activating the TLR4/MYD88 pathway. Last, the administration of ML355, a targeted inhibitor of Alox12, mitigated lung IRI in both murine hilar clamp/reperfusion and rat left lung transplant models. Collectively, our study indicates ALOX12 as a promising therapeutic strategy for lung IRI.

Applications of transcriptomics in ischemia reperfusion research in lung transplantation

Ischemia-reperfusion (IR) injury contributes to primary graft dysfunction, a major cause of early mortality after lung transplantation. Transcriptomics uses high-throughput techniques to profile the RNA transcripts within a sample and provides a unique view of the mechanisms underlying various biological processes. This review aims to highlight the applications of transcriptomics in lung IR injury studies, which have thus far revealed inflammatory responses to be the major event activated by IR, identified potential biomarkers and therapeutic targets, and investigated the mechanisms of therapeutic interventions. Ex vivo lung perfusion, together with advanced bioinformatic and transcriptomic techniques, including single-cell RNA-sequencing, microRNA profiling, and multi-omics, continue to expand the capabilities of transcriptomics. In the future, the construction of biospecimen banks and the promotion of international collaborations among clinicians and researchers have the potential to advance our understanding of IR injury and improve the management of lung transplant recipients.

Ferroptosis in health and disease

Ferroptosis is a pervasive non-apoptotic form of cell death highly relevant in various degenerative diseases and malignancies. The hallmark of ferroptosis is uncontrolled and overwhelming peroxidation of polyunsaturated fatty acids contained in membrane phospholipids, which eventually leads to rupture of the plasma membrane. Ferroptosis is unique in that it is essentially a spontaneous, uncatalyzed chemical process based on perturbed iron and redox homeostasis contributing to the cell death process, but that it is nonetheless modulated by many metabolic nodes that impinge on the cells' susceptibility to ferroptosis. Among the various nodes affecting ferroptosis sensitivity, several have emerged as promising candidates for pharmacological intervention, rendering ferroptosis-related proteins attractive targets for the treatment of numerous currently incurable diseases. Herein, the current members of a Germany-wide research consortium focusing on ferroptosis research, as well as key external experts in ferroptosis who have made seminal contributions to this rapidly growing and exciting field of research, have gathered to provide a comprehensive, state-of-the-art review on ferroptosis. Specific topics include: basic mechanisms, in vivo relevance, specialized methodologies, chemical and pharmacological tools, and the potential contribution of ferroptosis to disease etiopathology and progression. We hope that this article will not only provide established scientists and newcomers to the field with an overview of the multiple facets of ferroptosis, but also encourage additional efforts to characterize further molecular pathways modulating ferroptosis, with the ultimate goal to develop novel pharmacotherapies to tackle the various diseases associated with - or caused by - ferroptosis.

A modified orthotopic left lung transplantation model in rats

To enhance the operability of the rat orthotopic left lung transplantation model, we implemented several improvements and meticulously detailed the procedure. One hundred and thirty-one healthy male Sprague Dawley rats, weighing between 250 and 300 g, were utilized, with 64 serving as donors, 64 as recipients, and 3 as sham controls. We employed a modified three-cuff technique for the orthotopic left lung transplantation. Notably, our modified perfusion method could prevent donor lung edema, while waist-shaped cuffs minimized suture slippage during anastomosis. Additionally, positioning the recipient rat in a slightly left-elevated supine position during anastomosis reduced tension on the lung hilum, thus mitigating the risk of vascular laceration. The introduction of a unique two-person anastomosis technique significantly reduced operation time and substantially improved success rates. Furthermore, maximizing inflation of donor lungs both during preservation and surgery minimized the occurrence of postoperative atelectasis. Various other procedural refinements contributed to the enhanced operability of our model. Sixty-four rat orthotopic left lung transplantations were performed with only one surgical failure observed. The acquisition time for donor lungs averaged (19 ± 4) minutes, while (11 ± 1) minutes were allocated for donor lung hilum anatomy and cuff installation. Recipient thoracotomy and left lung hilar anatomy before anastomosis required (24 ± 8) minutes, with anastomosis itself taking (31 ± 6) minutes. Remarkably, the survival rate at the 4-h postoperative mark stood at 96.7 %. Even six months post-operation, transplanted left rat lungs continued to exhibit proper inflation and contraction rhythms, displaying signs of chronic pathological changes. In summary, our modified rat model of orthotopic left lung transplantation demonstrates robust operability, significantly reducing surgical duration, improving operation success rates, and enhancing postoperative survival rates. Furthermore, its long-term survival capacity enables the simulation of acute and chronic disease processes following lung transplantation.

Ferroptosis: a new target for hepatic ischemia-reperfusion injury?

Ischemia-reperfusion injury (IRI) can seriously affect graft survival and prognosis and is an unavoidable event during liver transplantation. Ferroptosis is a novel iron-dependent form of cell death characterized by iron accumulation and overwhelming lipid peroxidation; it differs morphologically, genetically, and biochemically from other well-known cell death types (autophagy, necrosis, and apoptosis). Accumulating evidence has shown that ferroptosis is involved in the pathogenesis of hepatic IRI, and targeting ferroptosis may be a promising therapeutic approach. Here, we review the pathways and phenomena involved in ferroptosis, explore the associations and implications of ferroptosis and hepatic IRI, and discuss possible strategies for modulating ferroptosis to alleviate the hepatic IRI.

Unraveling the Molecular Regulation of Ferroptosis in Respiratory Diseases

Ferroptosis, a type of programmed cell death that relies on iron, is distinct in terms of its morphological, biochemical and genetic features. Unlike other forms of cell death, such as autophagy, apoptosis, necrosis, and pyroptosis, ferroptosis is primarily caused by lipid peroxidation. Cells that die due to iron can potentially trigger an immune response which intensifies inflammation and causes severe inflammatory reactions that eventually lead to multiple organ failure. In recent years, ferroptosis has been identified in an increasing number of medical fields, including neurological pathologies, chronic liver diseases and sepsis. Ferroptosis has the potential to cause an inflammatory tempest, with many of the catalysts and pathological indications of respiratory ailments being linked to inflammatory reactions. The growing investigation into ferroptosis in respiratory disorders has also garnered significant interest to better understand the mechanism of ferroptosis in these diseases. In this review, the recent progress in understanding the molecular control of ferroptosis and its mechanism in different respiratory disorders is examined. In addition, this review discusses current challenges and prospects for understanding the link between respiratory diseases and ferroptosis.

Cellular and molecular mechanisms of cell damage and cell death in ischemia-reperfusion injury in organ transplantation

Ischemia-reperfusion injury (IRI) is a critical pathological condition in which cell death plays a major contributory role, and negatively impacts post-transplant outcomes. At the cellular level, hypoxia due to ischemia disturbs cellular metabolism and decreases cellular bioenergetics through dysfunction of mitochondrial electron transport chain, causing a switch from cellular respiration to anaerobic metabolism, and subsequent cascades of events that lead to increased intracellular concentrations of Na+, H+ and Ca2+ and consequently cellular edema. Restoration of blood supply after ischemia provides oxygen to the ischemic tissue in excess of its requirement, resulting in over-production of reactive oxygen species (ROS), which overwhelms the cells' antioxidant defence system, and thereby causing oxidative damage in addition to activating pro-inflammatory pathways to cause cell death. Moderate ischemia and reperfusion may result in cell dysfunction, which may not lead to cell death due to activation of recovery systems to control ROS production and to ensure cell survival. However, prolonged and severe ischemia and reperfusion induce cell death by apoptosis, mitoptosis, necrosis, necroptosis, autophagy, mitophagy, mitochondrial permeability transition (MPT)-driven necrosis, ferroptosis, pyroptosis, cuproptosis and parthanoptosis. This review discusses cellular and molecular mechanisms of these various forms of cell death in the context of organ transplantation, and their inhibition, which holds clinical promise in the quest to prevent IRI and improve allograft quality and function for a long-term success of organ transplantation.

Liproxstatin-1 Alleviated Ischemia/Reperfusion-Induced Acute Kidney Injury via Inhibiting Ferroptosis

Ferroptosis, as a novel regulable cell death, is characterized by iron overload, glutathione depletion, and an accumulation of lipid peroxides. Recently, it has been discovered that ferroptosis is involved in ischemia/reperfusion (I/R)-induced acute kidney injury (AKI) and plays a crucial role in renal tubular cell death. In this study, we tried to investigate the effect and mechanism of liproxstatin-1 (Lip-1) in I/R-induced AKI and seek the key regulator of ferroptosis in I/R-induced AKI. Mice were administrated with clamping bilateral renal pedicles for 30 min. We found that early growth response 1 (EGR1) might be a key regulator of ferroptosis, and Lip-1 could suppress ferroptosis via EGR1. Meanwhile, Lip-1 could reduce macrophage recruitment and the release of inflammatory cytokines. These findings indicated that Lip-1 alleviated I/R-induced AKI via regulating EGR1, and it might pave the theoretical basis of a new therapeutic strategy for I/R-induced AKI.

The Therapeutic Potential of Targeting Ferroptosis in the Treatment of Mitochondrial Cardiomyopathies and Heart Failure

ABSTRACT

Ferroptosis is a form of iron-regulated cell death implicated in a wide array of diseases, including heart failure, hypertension, and numerous cardiomyopathies. In addition, mitochondrial dysfunction has been associated with several of these same disease states. However, the role of the mitochondrion in ferroptotic cell death remains debated. As a major regulator of cellular iron levels, the mitochondria may very well play a crucial role in the mechanisms behind ferroptosis, but at this point, this has not been adequately defined. Emerging evidence from our laboratory and others indicates a critical role of mitochondrial Sirtuin 3, a deacetylase linked with longevity and protection against numerous conditions, in the prevention of cardiovascular diseases. Here, we provide a brief overview of the potential roles of Sirtuin 3 in mitochondrial iron homeostasis and its contribution to the mitochondrial cardiomyopathy of Friedreich's ataxia and diabetic cardiomyopathy. We also discuss the current knowledge of the involvement of ferroptosis and the mitochondria in these and other cardiovascular disease states, including doxorubicin-induced cardiomyopathy, and provide insight into areas requiring further investigation.

Fraxetin alleviates BLM-induced idiopathic pulmonary fibrosis by inhibiting NCOA4-mediated epithelial cell ferroptosis

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is a debilitating lung condition with few available treatments. The early driver of wound repair that contributes to IPF has been extensively identified as repetitive alveolar epithelial damage. According to recent reports, IPF is linked to ferroptosis, a unique type of cell death characterized by a fatal buildup of iron and lipid peroxidation.

OBJECTIVE AND METHOD

There is little information on epithelial cells that induce pulmonary fibrosis by going through ferroptosis. In this study, we used bleomycin (BLM) to examine the impact of ferroptosis on IPF in mouse lung epithelial cells (MLE-12).

RESULTS

We discovered that BLM increases ferroptosis in MLE-12. Additionally, we found that NCOA4 is overexpressed and plays a key role in the ferroptosis of epithelial cells throughout the IPF process. Using Molecular docking, we found that Fraxetin, a natural component extracted from Fraxinus rhynchophylla, formed a stable binding to NCOA4. In vitro investigations showed that Fraxetin administration greatly decreased ferroptosis and NCOA4 expression, which in turn lowered the release of inflammatory cytokines.

CONCLUSION

Fraxetin treatment significantly alleviated BLM-induced lung inflammation and fibrosis. Our findings imply that fraxetin possesses inhibitory roles in ferroptosis and can be a potential drug against IPF.