acyl-CoA Synthetase Long-chain Family Member Research Articles

The role of ACSL4 in stroke: mechanisms and potential therapeutic target.

Stroke, as a neurological disorder with a poor overall prognosis, has long plagued the patients. Current stroke therapy lacks effective treatments. Ferroptosis has emerged as a prominent subject of discourse across various maladies in recent years. As an emerging therapeutic target, notwithstanding its initial identification in tumor cells associated with brain diseases, it has lately been recognized as a pivotal factor in the pathological progression of stroke. Acyl-CoA synthetase long-chain family member 4 (ACSL4) is a potential target and biomarker of catalytic unsaturated fatty acids mediating ferroptosis in stroke. Specifically, the upregulation of ACSL4 leads to heightened accumulation of lipid peroxidation products and reactive oxygen species (ROS), thereby exacerbating the progression of ferroptosis in neuronal cells. ACSL4 is present in various tissues and involved in multiple pathways of ferroptosis. At present, the pharmacological mechanisms of targeting ACSL4 to inhibit ferroptosis have been found in many drugs, but the molecular mechanisms of targeting ACSL4 are still in the exploratory stage. This paper introduces the physiopathological mechanism of ACSL4 and the current status of the research involved in ferroptosis crosstalk and epigenetics, and summarizes the application status of ACSL4 in modern pharmacology research, and discusses the potential application value of ACSL4 in the field of stroke.

Role of Hippo/ACSL4 Axis in Ferroptosis-Induced Pericyte Loss and Vascular Dysfunction in Sepsis

Sepsis is a critical condition characterized by a systemic inflammatory response to infection, often leading to severe vascular dysfunction and high mortality. One of the hallmarks of vascular dysfunction in sepsis is increased vascular permeability and the loss of pericytes, which are essential for maintaining vascular integrity. Despite the significance of pericyte loss in sepsis, the primary type of cell death responsible and the underlying molecular mechanisms remain incompletely understood. This study aims to elucidate these mechanisms by focusing on ferroptosis, a form of programmed cell death, and its regulation through the Hippo/ACSL4 axis. Our research confirmed significant pericyte loss in patients with sepsis. Through advanced single-cell analysis and proteomics, ferroptosis was identified as a key differentiating cell death type between sepsis and sham samples. Further metabolomics analysis revealed that Acyl-CoA Synthetase Long-Chain Family Member 4 (ACSL4) plays a pivotal role in the ferroptosis of pericytes during sepsis. In vitro experiments demonstrated that downregulation of ACSL4 effectively reduced lipopolysaccharide (LPS)-induced lipid peroxidation, restored pericyte viability, and improved endothelial permeability. In vivo studies with pericyte-specific ACSL4 knockout mice showed a marked decrease in pericyte loss and enhanced vascular barrier function following sepsis induction. To translate these findings into potential therapeutic strategies, we developed pericyte-targeting liposomes encapsulating ACSL4 shRNA adenovirus. These liposomes successfully restored pulmonary vascular barrier function and significantly reduced pericyte loss in septic conditions. The results of this study underscore the crucial role of ACSL4 in mediating ferroptosis in pericytes and highlight the therapeutic potential of targeting ACSL4 to mitigate vascular dysfunction in sepsis.

Cefiderocol has immunoregulative effects in LPS-induced vitro experimental model via inhibiting inflammation and ferroptosis

BackgroundCefiderocol is a new catecholamine-containing siderophore cephalosporin. It, however, remains unclear how cefiderocol modulates the immune response of the host. ObjectivesThis study elucidated whether cefiderocol exerts immunoprotective effects in an in vitro experimental model induced with lipopolysaccharide (LPS). MethodsMouse macrophage RAW 264.7 cells were exposed to LPS (100 ng/mL) or LPS + cefiderocol (40 mg/L) to assess the immunomodulatory effect of cefiderocol in vitro. ELISA was performed on cell culture supernatants to estimate cytokine levels. Ferroptosis level was also quantified by detecting intracellular reactive oxygen species (ROS) and iron levels through flow cytometry analysis. Malondialdehyde (MDA) and glutathione (GSH) levels were estimated by ELISA. We conducted western blotting assay for evaluating key ferroptosis pathway proteins. ResultsCefiderocol alleviated LPS-induced inflammation by reducing IL-6, TNF-α, and IL-1β production levels and enhancing the IL-10 production level. Further analysis to determine the underlying mechanism revealed that cefiderocol inhibited ferroptosis; this was confirmed by reduced ROS, MDA, and Fe2+ ion levels; increased GSH levels; upregulated expression of solute carrier family 7 member 11, glutathione peroxidase 4, nuclear factor erythroid 2-related factor 2, and ferroptosis suppressor protein 1; and downregulated expression of acyl-CoA synthetase long-chain family member 4. ConclusionsCefiderocol may play a key role in reducing inflammation by decreasing inflammatory cytokine release and suppressing ferroptosis.

Asiatic acid induces lung cancer toxicity by triggering SRC-mediated ferroptosis

Ferroptosis is a recently discovered form of regulated cell death that shows promise as a novel approach for inducing tumor cell death in cancer treatment, with significant research potential. Asiatic acid (AA), a key component of the traditional Chinese medicine Centella asiatica, has been identified as having potential therapeutic benefits for various diseases, particularly cancer. Non-small cell lung cancer (NSCLC) is a challenging and prevalent form of cancer to treat. In our study, we utilized network pharmacology, molecular docking, and experimental methods to investigate the potential of AA in treating NSCLC and to elucidate its role in inhibiting cancer through the ferroptosis pathway. Through network pharmacology analysis, we identified that AA targets the core NSCLC protein SRC through the ferroptosis pathway. Our experiments demonstrated that treatment with AA led to increased iron accumulation, mitochondrial membrane potential, and expression of ferroptosis markers glutathione peroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), and acyl-CoA synthetase long chain family member 4 (ACSL4) in NSCLC cells, confirming the induction of ferroptosis. In conclusion, AA has the potential to target SRC and induce NSCLC cell death through the ferroptosis pathway, offering a promising approach for cancer treatment.

Ion Channel Piezo1 Induces Ferroptosis of Trabecular Meshwork Cells: A Novel Observation in the Pathogenesis in Primary Open Angle Glaucoma.

This study aims to elucidate the role of Piezo1, a mechanosensitive molecule, in trabecular meshwork cells (TMCs) in the context of Primary Open Angle Glaucoma (POAG), a leading cause of irreversible visual impairment. Dysfunction of the trabecular meshwork (TM) is a key factor in the elevated intraocular pressure (IOP) observed in POAG, yet the specific mechanisms leading to TM dysfunction are not fully understood. We performed cell stretching on human trabecular meshwork cells (HTMCs) and pharmacologically activated HTMCs with Yoda1 to study the role of Piezo1 in HTMCs. We focused on assessing cell viability, mitochondrial changes, lipid peroxidation, and the expression of ferroptosis-related targets such as acyl-CoA synthetase long-chain family member 4 (ACSL4) and glutathione peroxidase 4 (GPX4). Cell stretching induces ferroptosis in HTMCs, and this phenomenon is reversed by Piezo1 knockdown. Additionally, pharmacological activation of Piezo1 also leads to ferroptosis in HTMCs. Furthermore, inhibiting the JNK/p38 signaling pathway was found to mitigate the ferroptotic response induced by Yoda1, thereby confirming that Piezo1 induces ferroptosis in TMCs through this pathway. Notably, our experiments suggest that Yoda1 may trigger ferroptosis in the TM of mouse eyes. Our findings demonstrate that the Piezo1 pathway is a crucial mediator of ferroptosis in TMCs, providing new insights into the pathogenic mechanisms of glaucoma, particularly POAG. This study highlights the potential of targeting the Piezo1 pathway as a therapeutic approach for mitigating TM dysfunction and managing POAG.

Reduced glutathione attenuates pediatric sepsis-associated encephalopathy by inhibiting inflammatory cytokine release and mitigating lipid peroxidation-induced brain injury.

Sepsis-associated encephalopathy (SAE) is a severe complication of sepsis. Reduced glutathione (GSH) has antioxidant properties and is used as a neuroprotective agent in some studies. However, research on the application of exogenous GSH in the treatment of SAE is limited. This study aimed to determine the effects of exogenous GSH in pediatric SAE patients and mice. We evaluated clinical parameters, inflammatory factors, and oxidative stress before and after GSH treatment. The clinical trials demonstrated that GSH treatment improved brain damage markers (S-100 beta protein, brain fatty acid-binding protein), increased neurological status scores (Glasgow coma scale), and reduced Pediatric Risk of Mortality III scores in children with SAE. GSH treatment also significantly reduced the levels of inflammatory factors (interleukin-6, tumor necrosis factor-α) and decreased lipid peroxidation (superoxide dismutase). Additionally, GSH reduced lipid peroxidation resulting from abnormal lipid metabolism, as indicated by the levels of acyl-CoA synthetase long-chain family member 4, lysophosphatidylcholine acyltransferase 3, and glutathione peroxidase 4. In-vivo experiments showed that the neuroprotective effect of GSH was dose-dependent, with better effects observed at medium and high doses. Furthermore, GSH alleviated brain damage, suppressed the release of inflammatory factors, and inhibited lipid peroxidation in SAE mice. The animal experiments also showed that GSH reduces lipid peroxidation through the 15-lipoxygenase/phosphatidylethanolamine binding protein 1/glutathione peroxidase 4 pathway. Our study suggests that exogenous GSH has neuroprotective effects in pediatric SAE. These findings provide a basis for the potential use of GSH as a therapeutic method for SAE.

Deciphering heart failure: an integrated proteomic and transcriptomic approach with experimental validation.

This study analyzed transcriptomic and proteomic data to identify molecular changes during heart failure (HF). Additionally,we embarked on an exploration of the prospect of therapeutic intervention through the manipulation of proteins implicated in ferroptosis. Three publicly available microarray datasets (GSE135055, GSE147236, GSE161472) profiling left ventricular samples from HF patients and healthy controls were obtained. Differentially expressed genes were identified in each dataset and cross-analyzed to determine shared gene signatures. Enrichment analysis of Gene Ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and gene set enrichment analysis were performed. Differentially expressed proteins were obtained from published proteomic studies and integrated with the transcriptomic results. To validate findings, a HF mouse model was generated and ferroptosis-related proteins were evaluated. Additionally, the effect of suppression of ferroptosis on hypoxia-induced ischemia model in HL-1 cardiomyocytes was assessed by knocking down Acyl-CoA synthetase long-chain family member 4 (ACSL4) using small interfering RNA (siRNA).Cross-analysis of differentially expressed genes (DEGs) in the GSE135055, GSE147236 and GSE161472 datasets revealed 224 up-regulated and 187 down-regulated potential genes which showed high enrichment in immune, inflammatory and metabolic pathways. Notably, four proteins, among them ACSL4, displayed consistent alterations at both the transcriptional and protein levels. In the HF mouse model, ACSL4 exhibited an elevation, whereas negative regulators of ferroptosis witnessed a decrement. Subsequently, knockdown of ACSL4 in a hypoxia-induced ischemic HL-1 cardiomyocyte cell model upregulated the expression of ferroptosis inhibitory protein and decreased the levels of reactive oxygen species (ROS), malondialdehyde (MDA)., and free iron and increased cell viability. Comprehensive multi-omics analysis revealed that the expression of the molecular target ACSL4 was increased in HF. Targeting ACSL4 to inhibit ferroptosis may represent a novel therapeutic strategy for HF treatment.

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.

Overexpression of miR-451a Aggravates Renal Ischemia–Reperfusion Injury by Targeting KLF1-ACSL4 to Promote Ferroptosis

Ischemia–reperfusion injury (IRI) is a predominant factor leading to delayed graft function (DGF) following kidney transplantation. MicroRNAs (miRNAs) play a pivotal role in the pathogenesis of renal IRI, with ferroptosis being a critical driving force throughout the process. In this study, we utilized bioinformatics methods to construct a network diagram of differentially expressed miRNAs, transcription factors (TFs), and ferroptosis-related genes. An I/R-induced renal injury model in mice and an in vitro H/R-induced HK-2 cell injury model were established. Quantitative real-time PCR (qRT-PCR) and Western blot analysis were used to measure the mRNA and miRNA levels in cells and tissues. The MDA concentration, iron levels, and GSH concentration were measured to evaluate the ferroptosis levels. CCK-8 assays were performed to assess cell viability. Luciferase reporter assays were conducted to validate the downstream targets of miRNA, and chromatin immunoprecipitation assays were performed to verify the interaction between TFs and mRNAs. Both the in vivo and in vitro results demonstrate that miR-451a was significantly enriched in the IRI renal tissues and cells, exacerbating ferroptosis. MiR-451a was found to reduce the expression of Kruppel-like factor 1 (KLF1) by directly binding to the 3′UTR of KLF1 mRNA. Additionally, KLF1 was identified as a negative transcription factor for acyl-CoA synthetase long-chain family member 4 (ACSL4). We demonstrated that IRI induced the upregulation of miR-451a, which reduced KLF1 expression, thereby promoting ferroptosis by upregulating ACSL4 expression, ultimately aggravating IRI-induced renal damage.

Ferroptosis-Mediated Inflammation Promotes Pulmonary Hypertension.

Mitochondrial dysfunction, characterized by impaired lipid metabolism and heightened reactive oxygen species generation, results in lipid peroxidation and ferroptosis. Ferroptosis is an inflammatory mode of cell death that promotes complement activation and macrophage recruitment. In pulmonary arterial hypertension (PAH), pulmonary arterial endothelial cells exhibit cellular phenotypes that promote ferroptosis. Moreover, there is ectopic complement deposition and inflammatory macrophage accumulation in the pulmonary vasculature. However, the effects of ferroptosis inhibition on these pathogenic mechanisms and the cellular landscape of the pulmonary vasculature are incompletely defined. Multiomics and physiological analyses evaluated how ferroptosis inhibition-modulated preclinical PAH. The impact of adeno-associated virus 1-mediated expression of the proferroptotic protein ACSL (acyl-CoA synthetase long-chain family member) 4 on PAH was determined, and a genetic association study in humans further probed the relationship between ferroptosis and pulmonary hypertension. Ferrostatin-1, a small-molecule ferroptosis inhibitor, mitigated PAH severity in monocrotaline rats. RNA-sequencing and proteomics analyses demonstrated ferroptosis was associated with PAH severity. RNA-sequencing, proteomics, and confocal microscopy revealed complement activation and proinflammatory cytokines/chemokines were suppressed by ferrostatin-1. In addition, ferrostatin-1 combatted changes in endothelial, smooth muscle, and interstitial macrophage abundance and gene activation patterns as revealed by deconvolution RNA-sequencing. Ferroptotic pulmonary arterial endothelial cell damage-associated molecular patterns restructured the transcriptomic signature and mitochondrial morphology, promoted the proliferation of pulmonary artery smooth muscle cells, and created a proinflammatory phenotype in monocytes in vitro. Adeno-associated virus 1-Acsl4 induced an inflammatory PAH phenotype in rats. Finally, single-nucleotide polymorphisms in 6 ferroptosis genes identified a potential link between ferroptosis and pulmonary hypertension severity in the Vanderbilt BioVU repository. Ferroptosis promotes PAH through metabolic and inflammatory mechanisms in the pulmonary vasculature.

Liver iron stores and effectors of ferroptosis are dependent on age and sex.

Ferroptosis is a form of cell death characterized by a pro-oxidative cellular milieu and iron-dependent lipid peroxidation. Ferroptosis has been implicated in various forms of liver injury, in keeping with the major role of the liver in iron metabolism. Limited research has addressed potential differences in ferroptosis mediators with age and sex, especially in an in vivo model. The goal of this investigation was to evaluate hepatic labile iron and mediators of ferroptosis with ageing in both sexes. Because female animals generally display greater antioxidant defences than males, we hypothesized that females would display a phenotype resistant to ferroptosis. Here, we determined iron contents, protein expression of ferroptosis mediators and measures of oxidative injury in liver samples from 12- and 24-month-old male and female Fischer 344 rats. In comparison to males, the livers of female rats at both ages contained more non-haem iron, which was associated with greater ferritin heavy chain expression and attenuated expression of transferrin receptor-1. In female rats, the 24-month-old group had higher contents of thiobarbituric acid reactive substances compared with their 12-month-old counterparts, yet similar contents of labile iron. These results suggest a disconnect between labile iron contents and oxidative injury with age. Female animals also displayed greater expression of acyl-CoA synthetase long-chain family member 4 (ACSL4), a modulator of ferroptosis, and greater abundance of high molecular weight 4-hydroxnonenal-modified proteins. These results demonstrate clear differences in iron and ferroptosis mediators between sexes and suggest that female rats of this strain might be more susceptible to ferroptosis.

Succinylated Type I Collagen Regulates Ferroptosis to Attenuate Skin Photoaging.

During the process of photoaging in the skin, Succinylated type I collagen has a significant effect on reversing the damage caused by UVB radiation, with the regulation of cellular ferroptosis being one of its important pathophysiological mechanisms. Specifically, Succinylated type I collagen reduces the expression of key cell cycle regulators P16, P21, and P53, as well as the ferroptosis-related factor Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4), induced by UVB radiation in cells and tissues. Meanwhile, it increases the expression of key factors Glutathione Peroxidase 4 (GPX4) and Solute Carrier Family 7 Member 11 (SLC7A11), which inhibit ferroptosis. Additionally, our study also reveals the impact of Succinylated type I collagen on the levels of malondialdehyde (MDA), glutathione (GSH), and reactive oxygen species (ROS) in cells and tissues, directly affecting the cells' ability to cope with oxidative stress. This further suggests that Succinylated type I collagen may improve skin photoaging through various pathways, including regulating ferroptosis, antioxidation, promoting collagen synthesis, protecting the skin barrier, reducing pigmentation, and inhibiting inflammatory responses, contributing to maintaining healthy and youthful skin.

Cancer-associated fibroblast-secreted exosomal miR-454-3p inhibits lipid metabolism and ferroptosis in breast cancer by targeting ACSL4.

Cancer-associated fibroblasts (CAFs) participate in the development of the tumor microenvironment through the secretion of exosomes. Acyl-CoA synthetase long-chain family member 4 (ACSL4) is an essential component of ferroptosis. However, the regulatory mechanism of ACSL4 in breast cancer remains unexplored. The study aimed to determine the influence of exosomal miR-454-3p from CAFs on lipid metabolism and ferroptosis. CAF-derived exosomes (CAF-exo) were isolated from breast cancer tissue of breast cancer patients and characterized using transmission electron microscopy (TEM) and Western blot. Luciferase reporter assay and RNA immunoprecipitation (RIP) were used to demonstrate the relationship between miR-454-3p and ACSL4. Cell viability and ferroptosis-related markers were detected by CCK-8 and Western blot. Malondialdehyde (MDA), glutathione (GSH), and iron levels were detected. Reverse transcription-quantitative PCR (RT-qPCR) and fluorescence in situ hybridization (FISH) were used to assess miR-454-3p expression. miR-454-3p and ACSL4 levels were abnormally expressed in breast cancer tissues. CAF-exo significantly enhanced cell viability and GSH levels and suppressed MDA, and iron levels. CAF-exo upregulated ferroptosis suppressor protein 1 (FSP1) and glutathione peroxidase 4 (GPX4) expression, and reduced ACSL4 levels. miR-454-3p was strongly expressed in CAF-exo, and exosomal miR-454-3p suppressed lipid metabolism and ferroptosis in breast cancer cells. The effects of miR-454-3p inhibitor on lipid metabolism and ferroptosis were eliminated by ACSL4 knockdown. CAF-secreted exosomal miR-454-3p inhibited lipid metabolism and ferroptosis by targeting ACSL4 in breast cancer. This study revealed a novel molecular mechanism that offers a potential therapeutic intervention in breast cancer treatment.

Ferroptosis Regulated by 5-HT3a Receptor via Calcium/Calmodulin Signaling Contributes to Neuropathic Pain in Brachial Plexus Avulsion Rat Models.

Neuropathic pain is a prevalent complication following brachial plexus avulsion (BPA). Ferroptosis has been implicated in various nervous system disorders. However, the association between ferroptosis and neuropathic pain induced by BPA remains unclear. This study aimed to investigate the role of ferroptosis in BPA-induced neuropathic pain. A rat model of neuropathic pain was established via BPA induction. Pain thresholds of rats were measured after BPA surgery and intraperitoneal injection of Fer-1. On day 14 postsurgery, spinal dorsal horn (SDH) samples were collected for Western blotting, biochemical analysis, and immunohistochemistry to analyze the expression and distribution of ferroptosis-related markers. The relationships among 5-HT3a receptor, calcium/calmodulin (CaM) pathway, and ferroptosis were assessed via Western blotting, biochemical analysis, and lipid peroxidation assays, including iron and calcium content, reactive oxygen species, glutathione peroxidase 4 (GPX4), ACSL, and CaM expression. BPA-induced neuropathic pain was associated with iron accumulation, increased lipid peroxidation, dysregulated expression of Acyl-CoA synthetase long-chain family member 4, and GPX4, and changes in transferrin receptor, divalent metal transporter 1, and ferroportin-1 (FPN1). Intraperitoneal administration of Fer-1 reversed all of these alterations and mitigated mechanical and cold hypersensitivity. Inhibition of the 5-HT3a receptor reduced the extent of ferroptosis. Furthermore, the 5-HT3a receptor can regulate the calcium/CaM pathway via L-type calcium channels (LTCCs), and blocking LTCCs with nifedipine also alleviated ferroptosis in the SDH of BPA rats. Taken together, in rats with BPA, the development of neuropathic pain involves ferroptosis, which is regulated by the 5-HT3a receptor through the LTCCs and the calcium/CaM signaling pathway in the SDH.

Serum ACSL4 levels in prostate cancer patients and its relationship between patient prognosis: A prospective observational study.

In this prospective observational study, our objective was to investigate the serum levels of Acyl-CoA synthetase long-chain family member 4 (ACSL4) in prostate cancer (PCa) patients and examine its association with other serum biomarkers, and the clinical outcomes of PCa patients. This prospective observational study was conducted from January 2019 to October 2021, including 103 cases of PCa patients and 101 cases of benign prostate hyperplasia (BPH) patients who received treatment at our hospital. All patients had their serum ACSL4 levels measured using enzyme-linked immunosorbent assay before treatment. The clinical outcomes included age, body mass index, gender, systolic blood pressure, diastolic blood pressure, tumor node metastasis stage, Gleason scores, and prostate volume and serum biomarkers were collected. All patients were followed up for 36 months, the overall survival and disease-free survival were recorded for all patients. All data used SPSS 26.0 for analysis. The phosphorus (P) and serum low-density lipoprotein cholesterol levels were significantly higher in PCa patients compared to BPH patients. Furthermore, compared to the BPH patients, the serum ACSL4 and free prostate-specific antigen levels were significantly decreased while serum total prostate-specific antigen (tPSA) levels were significantly elevated in PCa patients. Pearson correlation analysis showed a positive correlation between ACSL4 levels and free prostate-specific antigen levels, while a negative correlation was observed with P and tPSA levels. ACSL4 might serve as a biomarker for diagnosing PCa with the AUC was 0.747, cutoff value of 33.68 ng/mL, sensitivity of 70.3%, and specificity of 60.2%. Finally, we found that ACSL4, tPSA, and P were identified as risk factors associated with PCa patients. Our findings indicated that the serum levels of ACSL4 were significantly decreased in PCa patients compared to BPH patients. Serum ACSL4 could be used as a potential biomarker for early PCa diagnosis and prognosis.

Network pharmacology, molecular docking and experimental study on the mechanism of Curcumin's anti-ferroptosis in melanocytes

Ferroptosis is a form of regulated nonapoptotic cell death associated with iron-dependent lipid peroxidation, closely associated with Vitiligo. Although the impact of Curcumin (Cur), a polyphenolic compound derived from the plant Curcuma longa Linn, on vitiligo has been established, the specific role and potential mechanistic pathways through which Cur modulates ferroptosis in vitiligo remain elusive. In this study, the critical targets and potential mechanisms of Cur in treating vitiligo were predicted by network pharmacology and molecule docking. Then, the effects of Cur on Erastin-induced ferroptosis were investigated in melanocytes induced by Erastin in vitro. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of Cur acting on Vitiligo found that these intersection genes are associated with the vitiligo oxidative stress pathway, including nuclear factor erythroid 2-related factor 2(Nrf2)/Heme Oxygenase 1(HO-1) signaling pathway. Further molecular docking shows that Cur has a good binding effect with Nrf2(the binding energy of Cur and Nrf2 protein is −6 kcal/mol). Through the CCK8 assay, showed that 10 μM Cur treatment 24 h after Erastin significantly improved cell viability In vitro. Then we found that Erastin induced cell death, ROS production, the mitochondrial membrane potential(MMP) decreased, Superoxide dismutase (SOD) and Glutathione (GSH) levels reduced, Malonaldehyde (MDA) and iron ion accumulation in melanocytes. In addition, the expression of glutathione peroxidase 4(GPX4) mRNA and protein was inhibited, while the expression of acyl-CoA synthetase long-chain family member 4(ACSL4), Transferrin Receptor Protein 1(TFR1) mRNA and protein was increased. However, the damage induced by Erastin was significantly relieved by Cur and Fer-1 treatment. Mechanistically, Cur treatment significantly promoted nuclear translocation of transcriptional factor Nrf2 and HO-1 expression. Interestingly, pretreatment with ML385, a selective Nrf2 inhibitor, counteracted anti-ferroptosis effects induced by Cur treatment. Taken together, these results demonstrate that Cur inhibits ferroptosis by regulating the Nrf2/HO-1 pathway to protect melanocytes.

Mild therapeutic hypothermic protection activates the PI3K/AKT signaling pathway to inhibit TRPM7 and suppress ferroptosis induced by myocardial ischemia‑reperfusion injury.

The present study aimed to investigate the role of PI3K‑mediated ferroptosis signaling induced by mild therapeutic hypothermia (MTH), which was defined as a temperature of 34˚C, in protecting against myocardial ischemia-reperfusion (I/R) injury (MIRI). To meet this aim, H9C2 cells underwent hypoxia‑reperfusion (H/R) and/or MTH. The MTT assay was used to assess cell viability, cytotoxicity was measured using a lactate dehydrogenase cytotoxicity assay, and Annexin V‑FITC/PI flow cytometric analysis was used to analyze early and late cell apoptosis. In addition, 84 healthy adult male Sprague‑Dawley rats were randomly divided into seven groups (n=12), and underwent I/R and various treatments. Hemodynamics were monitored, and the levels of myocardial injury marker enzymes and oxidative stress markers in myocardial tissue were measured using ELISA. The expression levels of PI3K, AKT, transient receptor potential cation channel subfamily M member 7 (TRPM7), glutathione peroxidase 4 (GPX4) and acyl‑CoA synthetase long chain family member 4 (ACSL4) in animals and cells were measured using western blot analysis. These experiments revealed that MTH could effectively reduce myocardial infarct size, improve hemodynamic performance following MIRI and suppress myocardial apoptosis, thereby contributing to the recovery from H/R injury. Mechanistically, MTH was revealed to be able to activate the PI3K/AKT signaling pathway in cells, upregulating GPX4, and downregulating the expression levels of TRPM7 and ACSL4. Treatment with 2‑aminoethoxydiphenyl borate (an inhibitor of TRPM7) could further strengthen the myocardial protective effects of MTH, whereas treatment with erastin (promoter of ferroptosis) and wortmannin (inhibitor of PI3K) led to the effective elimination of the myocardial protective effects of MTH. Compared with in the I/R group, the PI3K/AKT activation level and the expression levels of GPX4 were both significantly increased, whereas the expression levels of TRPM7 and ACSL4 were significantly decreased in the I/R + MTH group. Taken together, the results of the present study indicated that MTH may activate the PI3K/AKT signaling pathway to inhibit TRPM7 and suppress ferroptosis induced by MIRI.

ACSL4-mediated lipid rafts prevent membrane rupture and inhibit immunogenic cell death in melanoma

Chemotherapy including platinum-based drugs are a possible strategy to enhance the immune response in advanced melanoma patients who are resistant to immune checkpoint blockade (ICB) therapy. However, the immune-boosting effects of these drugs are a subject of controversy, and their impact on the tumor microenvironment are poorly understood. In this study, we discovered that lipid peroxidation (LPO) promotes the formation of lipid rafts in the membrane, which mediated by Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4) impairs the sensitivity of melanoma cells to platinum-based drugs. This reduction primarily occurs through the inhibition of immunogenic ferroptosis and pyroptosis by reducing cell membrane pore formation. By disrupting ACSL4-mediaged lipid rafts via the removal of membrane cholesterol, we promoted immunogenic cell death, transformed the immunosuppressive environment, and improved the antitumor effectiveness of platinum-based drugs and immune response. This disruption also helped reverse the decrease in CD8+ T cells while maintaining their ability to secrete cytokines. Our results reveal that ACSL4-dependent LPO is a key regulator of lipid rafts formation and antitumor immunity, and that disrupting lipid rafts has the potential to enhance platinum-based drug-induced immunogenic ferroptosis and pyroptosis in melanoma. This novel strategy may augment the antitumor immunity of platinum-based therapy and further complement ICB therapy.

ETV4‑mediated transcriptional activation of SLC12A5 exacerbates ferroptosis resistance and glucose metabolism reprogramming in breast cancer cells.

Solute carrier family 12 member 5 (SLC12A5) is an oncogene in numerous types of cancer, however its function in breast cancer (BC) remains elusive. ETS translocation variant 4 (ETV4) promotes BC. Therefore, the present study aimed to elucidate the role of SLC12A5 in ferroptosis and glucose metabolism in BC cells as well as to understand the underlying mechanism. Analysis of data from the UALCAN database demonstrated expression levels of SLC12A5 in BC and its association with prognosis. Reverse transcription‑quantitative PCR and western blotting were conducted to evaluate the expression levels of SLC12A5 and ETV4 in BC cells. The abilities of BC cells to proliferate, migrate and invade were assessed using Cell Counting Kit‑8, colony formation, wound healing and Transwell assays. Thiobarbituric acid reactive substances assay and a C11 BODIPY 581/591 probe were used to evaluate lipid peroxidation. Ferroptosis resistance was evaluated by the measurement of Fe2+ and ferroptosis‑related solute carrier family 7a member 11 (SLC7A11), glutathione peroxidase 4 (GPX4), acyl‑CoA synthetase long‑chain family member 4 (ACSL4) and transferrin receptor 1 (TFR1) protein levels. Glycolysis was assessed via evaluation of extracellular acidification rate, oxygen consumption rate, lactate production and glucose consumption. Finally, luciferase reporter and chromatin immunoprecipitation assay were used to verify the interaction between ETV4 and the SLC12A5 promoter. UALCAN database analysis indicated that SLC12A5 was upregulated in BC tissues and cells and that SLC12A5 elevation indicated a poor prognosis of patients with BC. SLC12A5 knockdown suppressed the BC cell proliferative, migratory and invasive capabilities. Moreover, SLC12A5 knockdown decreased BC cell ferroptosis resistance and glucose metabolism reprogramming. The transcription factor ETV4 was demonstrated to bind to the SLC12A5 promoter and upregulate its transcription. Furthermore, ETV4 overexpression counteracted the suppressive effect of SLC12A5 knockdown on the BC cell proliferative, migratory and invasive abilities, as well as on ferroptosis resistance and glucose metabolism reprogramming. Transcriptional activation of SLC12A5 by ETV4 modulated the migration, invasion, ferroptosis resistance and glucose metabolism reprogramming of BC cells.

Ablation of mitophagy receptor FUNDC1 accentuates septic cardiomyopathy through ACSL4-dependent regulation of ferroptosis and mitochondrial integrity

Sepsis evokes compromised myocardial function prompting heart failure albeit target therapy remains dismal. Our study examined the possible role of mitophagy receptor FUNDC1 in septic cardiomyopathy. A sepsis model was established using cecal ligation and puncture (CLP) in FUNDC1 knockout (FUNDC1−/−) and WT mice prior to the evaluation of cardiac morphology, echocardiographic and cardiomyocyte contractile, oxidative stress, apoptosis, necroptosis, and ferroptosis. RNAseq analysis depicted discrepant patterns in mitophagy, oxidative stress and ferroptosis between CLP-challenged and control murine hearts. Septic patients displayed cardiac injury alongside low plasma FUNDC1 and iron levels. CLP evoked interstitial fibrosis, cardiac dysfunction (lowered ejection fraction, fractional shortening, shortening/relengthening velocity, peak shortening and electrically-stimulated intracellular Ca2+ rise, alongside increased LV end systolic diameter and relengthening duration), O2− buildup, apoptosis, necroptosis, and ferroptosis (downregulated GPX4 and SLC7A11), the responses of which were accentuated by FUNDC1 ablation. In particular, levels of lipid peroxidation enzyme acyl-CoA synthetase long-chain family member 4 (ACSL4) were upregulated following CLP procedure, with a more pronounced response in FUNDC1−/− mice. Co-immunoprecipitation and interaction interface revealed an evident interaction between FUNDC1 and ACSL4. In vitro studies revealed that the endotoxin lipopolysaccharide provoked cardiomyocyte contractile and lipid peroxidation anomalies, the responses were reversed by the mitophagy inducer oleanolic acid, inhibition of ACSL4 and ferroptosis. These findings favor a role for FUNDC1-ACSL4-ferroptosis cascade in septic cardiomyopathy.