Glutathione Peroxidase 4 Levels Research Articles

TRIM22 mechanism promoting KAT2A ubiquitination degradation to regulate ferroptosis in hepatocellular carcinoma cell invasion and metastasis.

Hepatocellular carcinoma (HCC) is a highly fatal cancer. This study aims to investigate the underlying mechanism of tripartite motif-containing 22 (TRIM22) in HCC cell invasion and metastasis through the K (lysine) acetyltransferase 2A (KAT2A)/glutathione peroxidase 4 (GPX4) axis. Human HCC cells BEL7405 were cultured in vitro and treated with MG-132, Ferrostain-1, pcDNA3.1-TRIM22, pcDNA3.1-KAT2A, or pcDNA3.1-NC. TRIM22-KAT2A interaction and KAT2A ubiquitination level, cell proliferation, invasion, migration, and histone H3 lysine 9 acetylation (H3K9ac) enrichment level on the GPX4 promoter were assessed by Co-IP, CCK-8, Transwell, and ChIP-qPCR assays. Mice were injected subcutaneously with Lv-oe-NC or Lv-oe-TRIM22 BEL7405 cells via the tail vein. Tumor proliferation and levels of TRIM22, KAT2A, GPX4, Fe2+, malondialdehyde (MDA), reactive oxygen species (ROS), and glutathione (GSH) in tissues and cells were evaluated by immunohistochemistry, RT-qPCR, western blot, and kits. oe-TRIM22-treated BEL7405 cells exhibited increased TRIM22 expression, and abated KAT2A protein expression and malignant cell biological behaviors, which were partially reversed by upregulating KAT2A or suppressing ferroptosis. TRIM22 interacted with KAT2A, which was ubiquitinated to regulate GPX4 histone acetylation. TRIM22 overexpression elevated Fe2+, MDA, and ROS levels and cell death, and diminished GSH, GPX4, and H3K9ac enrichment levels, whereas further overexpression of KAT2A brought about opposite trends. TRIM22 suppressed HCC growth and metastasis by mediating ferroptosis through the KAT2A/GPX4 axis. TRIM22 promoted KAT2A ubiquitination degradation to reduce H3K9ac enrichment levels in the GPX4 promoter region, and facilitated ferroptosis, thereby inhibiting HCC cell invasion and metastasis and in vivo growth and metastasis.

Targeting inhibition of T3JAM reduces brain cell ferroptosis in rat following ischemia/reperfusion via a mechanism involving prevention of TLR4-mediated iron overload

Iron overload-dependent ferroptosis is believed to contribute to the brain injury of ischemia/reperfusion (I/R), whereas toll-like receptor 4 (TLR4) can exert pro-ferroptosis effect via inhibiting the glutathione peroxidase 4 (GPX4) level, but the mechanisms behind these phenomenon are not fully elucidated. Tumor necrosis factor receptor correlated factor 3-interaction Jun amino-terminal kinase [JNK]-activating modulator (T3JAM) can activate specific molecule and its downstream signaling pathways, including TLR4. This study aims to explore whether targeting T3JAM can reduce I/R-induced ferroptosis in brain via downregulating TLR4. A Sprague Dawley (SD) rat model of cerebral I/R injury was established by 2 h-ischemia plus 24 h-reperfusion, which displayed brain injury (increases in neurological deficit score and infarct volume) and upregulation of T3JAM and TLR4, concomitant with the increased ferroptosis, reflected by increases in the levels of transferrin receptor protein 1 (TfR1), total iron, Fe2+ and lipid peroxidation (LPO) while decreases in the levels of ferroportin (FPN) and GPX4. Consistently, similar results were achieved in the cultured HT22 cells subjected to 8h-oxygen-glucose deprivation plus 12 h-reoxygenation (OGD/R), and knockdown of T3JAM reversed these phenomena. Moreover, Telaprevir, an anti-hepatitis C virus (HCV) drug, could also provide beneficial effect on alleviating ischemic brain injury via inhibition of T3JAM. Based on these observations, we conclud that inhibition of T3JAM can reduce I/R-induced brain cell ferroptosis through downregulating TLR4 and that T3JAM could be a potential target for identifying novel or existing drugs (such as Telaprevir) to treat cerebral I/R injury.

Rbbp6-Mediated Bmal1 Ubiquitination Inhibits YAP1 Signaling Pathway to Promote Ferroptosis in Diabetes-Induced Testicular Damage.

Diabetes-induced testicular damage (DITD) is a common complication of diabetes. We investigated underlying mechanism of retinoblastoma-binding protein 6 (Rbbp6)-mediated brain and muscle ARNT-like 1 (Bmal1) ubiquitination in modulating ferroptosis in DITD. Spermatogenic cell apoptosis and viability were measured by flow cytometry and cell counting kit 8 (CCK-8), respectively. The impact of Rbbp6 and Bmal1 on ferroptosis was assessed by determining expression of ferroptosis markers glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11), and levels of malondialdehyde (MDA), glutathione (GSH), iron, and lipid peroxidation. Co-immunoprecipitation was performed to determine the interaction between Rbbp6 and Bmal1, as well as the ubiquitination level of Bmal1. The expression levels of Rbbp6, Bmal1, Yes-associated protein 1 (YAP1), ferroptosis markers, and testicular steroidogenic enzymes were tested by Western blot. Bmal1 protein expression was significantly downregulated, while Rbbp6 was upregulated in DITD mouse model and high glucose (HG)-induced GC-1 spg cells. Overexpression of Bmal1 improved testicular injury in diabetic mice, reduced 4-hydroxynonenal (4-HNE), MDA, iron levels, and increased expression levels of GPX4, SLC7A11, GSH, as well as testicular steroidogenic enzymes. Rbbp6 decreased Bmal1 level through promoting its ubiquitination. Meanwhile, Rbbp6 knockdown inhibited the ferroptosis of HG-induced GC-1 spg cells, which were abolished by silencing Bmal1. In addition, knockdown of YAP1 or treatment with ferroptosis inducer erastin blocked the above effects caused by Bmal1 overexpression. Rbbp6-mediated Bmal1 ubiquitination suppressed YAP1 pathway, promoting ferroptosis in DITD. This study highlighted Rbbp6/Bmal1/YAP1 axis as a potential therapeutic target for mitigating DITD.

The contribution of SLC7A11-mediated ferroptosis to cardiac injury in iron overload cardiomyopathy: an in vitro study

Abstract Background Recent studies have indicated that iron overload can induce myocardial ferroptosis in iron overload cardiomyopathy (IOC), but the specific mechanisms, including the role of SLC7A11, remain unclear. Purpose By delving into the role of SLC7A11-mediated ferroptosis in IOC, this research endeavors to provide novel insights and therapeutic strategies for understanding and treating IOC. Methods To induce an in vitro model of IOC, wild-type rat cardiomyocytes (H9C2) were cultured in a ferric citrate (FAC) medium. Cardiomyocytes were exposed to various concentrations of iron overload (ranging from 0 mM to 2 mM) for durations of 4, 8, 12, and 24 hours. Cell viability at different FAC concentrations was assessed by the cell counting kit-8 (CCK8) assay and the level of the ferroptosis indicator malondialdehyde (MDA) was measured to determine the optimal concentration and duration of FAC treatment which was required to establish the IOC cell model. Next, ferroptosis indicators, including MDA, prostaglandin peroxide synthase 2 (PTGS2), and glutathione peroxidase 4 (GPX4), and the pivotal factor, SLC7A11 of IOC cardiomyocytes were evaluated. The protein and mRNA levels of SLC7A11 were assessed by molecular biology techniques. Additionally, the mitochondrial morphology of the IOC cardiomyocytes was meticulously examined by transmission electron microscopy (TEM). Flow cytometry was employed for detecting reactive oxygen species (ROS) levels. Furthermore, we elucidated the underlying mechanism of myocardial injury in IOC by overexpressing SLC7A11 and subsequently detecting changes in ferroptosis markers. Results CCK-8 results showed that the viability of cardiomyocytes exhibited dose-dependently with increasing FAC concentration (R2=0.5483, p<0.0001). Furthermore, the viability of cardiomyocytes remained relatively stable, with survival rates of approximately 50% and not decreasing below 50%. Additionally, the MDA content in IOC cardiomyocytes increased dose-dependently with the elevation of FAC concentration (R2=0.75, p<0.05), with a significant increase observed at 0.75mM. Expression levels of ferroptosis marker genes, GPX4 and PTGS2, both at the mRNA and protein levels, are indicative of diminished antioxidant capacity. Meanwhile, the level of myocardial MDA and ROS were markedly elevated, indicating underscoring increased oxidative stress within the IOC cardiomyocytes. Moreover, there was a downregulation in the expression of SLC7A11 mRNA and protein in IOC cardiomyocytes, suggesting a potential compensatory mechanism to counteract oxidative damage. TEM further elucidated cardiac mitochondrial injuries in IOC rats, including focal vacuolization, swelling, crest disruption, and even disappearance. Overexpression of SLC7A11 resulted in a significant augmentation of GPX4 and a reduction of PTGS2mRNA and protein expression levels. Conclusions Ferroptosis, mediated by SLC7A11, may represent a pivotal mechanism underlying myocardial injury in IOC.

Bufalin induces ferroptosis by modulating the 2,4-dienoyl-CoA reductase (DECR1)-SLC7A11 axis in breast cancer

Breast cancer (BC) is a leading cause of cancer-related mortality worldwide. 2,4-dienoyl-CoA reductase (DECR1), an auxiliary component of beta-oxidation, has been recognized for its role in enhancing lipid peroxidation and inducing ferroptosis in prostate cancer. However, its involvement in breast cancer remains largely unexplored. Our study revealed a notably elevated expression of DECR1 in breast cancer tissues, which correlated with increased malignant characteristics. Importantly, the overexpression of DECR1 significantly enhanced proliferation and migration capabilities in MDA-MB-231 cells. Through a comprehensive high-content screening approach, we identified bufalin and its derivative as potent inhibitors of DECR1 expression. Notably, bufalin demonstrated the highest binding energy during molecular docking studies and was found to promote the degradation of DECR1 via autophagy and ubiquitination. Furthermore, bufalin induced ferroptosis in MDA-MB-231 cells by modulating levels of malondialdehyde (MDA), triglycerides (TG), reactive oxygen species (ROS) and Fe2+ while downregulating the expression of hormone-sensitive lipase (HSL), ferritin heavy chain protein 1 (FPN), solute carrier family 7 member 11 (SLC7A11), and glutathione peroxidase 4 (GPX4). These effects were counteracted by DECR1 overexpression. In vivo experiments demonstrated that bufalin inhibited the tumor growth, while decreasing the expression levels of HSL, FPN, SLC7A11, and GPX4, alongside increasing levels of 4-hydroxynonenal (4-HNE). Crucially, the ferroptosis effects induced by bufalin in vivo were also reversed by DECR1 overexpression. Subsequently, we discovered that SLC7A11 interacts with DECR1, inhibition of SLC7A11 led to decreased expression levels of DECR1 along with an accumulation of MDA and Fe2+, effects that were similarly reversed by DECR1 overexpression. Collectively, our findings suggest that targeted therapy against DECR1 combined with further inhibition of its downstream pathway involving SLC7A11/GPX4 may represent a promising strategy for treating breast cancer.

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.

Long-term exposure of sucralose induces neuroinflammation and ferroptosis in human microglia cells via SIRT1/NLRP3/IL-1β/GPx4 signaling pathways.

Microglia serve as the primary defense mechanism in the brain. Artificial sweeteners are widely used as dietary supplements, though their long-term effects remain uncertain. In this study, we investigated the effects of sucralose on microglia during prolonged exposure via the neuroinflammatory and ferroptosis pathways. Initially, human microglial clone 3 (HMC3) cells were exposed to sucralose (0-50 mM) for 24, 48, and 72 h to investigate the short-term effects. Subsequently, HMC3 cells were treated with 1 mM sucralose for 7, 14, and 21 days to examine long-term effects. We measured levels of interleukin-1β (IL-1β), NOD-like receptor protein 3 (NLRP3), 8-hydroxydeoxyguanosine (8-OHdG), Sirtuin-1 (SIRT1), glutathione peroxidase-4 (GPx4), reduced glutathione (GSH), malondialdehyde (MDA), ferrous iron (Fe2+), and caspase 3/7. Additionally, we analyzed the impact of sucralose on cell morphology, migration, and expression levels of IL-1β, NLRP3, SIRT1, and GPx4. Sucralose inhibited cell viability and proliferation in HMC3 cells in a concentration- and time-dependent manner and induced membrane and nuclear abnormalities. Moreover, sucralose significantly reduced the cell migration rate. Long-term sucralose treatment decreased Fe2+, GPx4, GSH, and SIRT1 levels in HMC3 cells while increasing IL-1β, MDA, NLRP3, 8-OHdG, and caspase 3/7 activity. Sucralose treatment also enhanced microglial activation and neuroinflammation by upregulating IL-1β and NLRP3 and downregulating SIRT1 and GPx4, thereby inducing ferroptosis and suppressing cell viability. Consequently, high concentrations or long-term sucralose treatment may induce neuroinflammation and ferroptosis by targeting the SIRT1/NLRP3/IL-1β/GPx4 pathway in HMC3 cells.

Evaluation of Known Markers of Ferroptosis in Semen of Patients with Different Reproductive Pathologies and Fertile Men.

This study aims to investigate the role of ferroptosis, an iron-dependent form of regulated cell death, in male infertility. The motivation behind this research stems from the increasing recognition of oxidative stress and iron metabolism dysregulation as critical factors in male reproductive health. In this study, 28 infertile patients (grouped by the presence of urogenital infections or varicocele) and 19 fertile men were selected. Spermiograms were performed by light microscopy (WHO, 2021). Testosterone, ferritin, transferrin-bound iron, transferrin, and F2-isoprostanes (F2-IsoPs) were detected in seminal plasma. Glutathione peroxidase 4 (GPX4) and acyl coenzyme A synthetase long chain family member 4 (ACSL4) were also assessed in sperm cells using enzyme-linked immunosorbent assays (ELISA). All the variables were correlated (statistically significant Spearman's rank correlations) in the whole population, and then the comparison between variables of the different groups of men were carried out. Seminal ferritin and transferrin positively correlated with seminal F2-IsoPs, which had positive correlations with ACSL4 detected in sperm cells. Ferritin and ACSL4 negatively correlated with the seminal parameters. No correlation was detected for GPX4. Comparing the variables in the three examined groups, elevated levels of ACSL4 were observed in infertile patients with urogenital infections and varicocele; GPX4 levels were similar in the three groups. These results suggested a mechanism of ferroptosis, identified by increased ACSL4 levels and the occurrence of lipid peroxidation. Such events appear to be GPX4-independent in reproductive pathologies such as varicocele and urogenital infections.

Association of Microbleeds on Susceptibility-Weighted Imaging with Ferroptosis and Prognosis in Rabbits with Spinal Cord Injury.

Susceptibility-weighted imaging (SWI) is a common imaging technique used to identify cerebral microbleeds. Given that spinal cord injury (SCI) often creates an environment that favors ferroptosis, a type of cell death driven by iron, this study aimed to explore the relationship between microbleeds on SWI and ferroptosis, and explore the effect of deferoxamine on SCI. Thirty-six rabbits were divided into three groups: sham, SCI, and SCI with deferoxamine (DFO, a ferroptosis inhibitor) treatment (SCI+DFO). Following 48 hours of SCI modeling, the rabbits underwent magnetic resonance imaging (MRI) and SWI examinations. Ferroptosis markers and spinal cord tissue morphology were examined, and the modified Tarlov's score was used to assess neurological function. SWI analysis revealed that rabbits in the SCI group exhibited lower signal intensities and larger microbleed areas compared to the those in the SCI+DFO group (p < 0.05). The SCI+DFO group demonstrated significantly decreased iron and malondialdehyde (MDA) levels, coupled with increased glutathione (GSH) and glutathione peroxidase 4 (GPX4) levels, along with attenuated ferroptosis (p < 0.05). This group also displayed greater Neuronal Nuclei (NeuN) expression, Tarlov's scores, and neurological recovery rates (all p < 0.05). A significant positive correlation was found between the microbleed area and iron content (r = 0.59, p = 0.04), MDA (r = 0.75, p = 0.01), and mitochondrial damage (r = 0.90, p < 0.01). Conversely, a negative correlation was established between the microbleed area and GPX4 levels (r = -0.87, p < 0.01), as well as neurological function recovery (r = -0.62, p = 0.03). The extent of microbleeds on SWI following SCI is closely correlated with ferroptosis, and the inhibition of ferroptosis could improve neurologic function. These findings suggest that the area of microbleeds on SWI could potentially serve as a predictive marker for ferroptosis in spinal cord injury.

Butylphthalide inhibits ferroptosis and ameliorates cerebral Ischaemia–Reperfusion injury in rats by activating the Nrf2/HO-1 signalling pathway

This study aims to investigate whether butylphthalide can inhibit ferroptosis and ameliorate cerebral ischaemia–reperfusion (I/R) injury in rats by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) / heme oxygenase-1 (HO-1) signalling pathway, known for its antioxidative and cytoprotective properties. Middle cerebral artery occlusion reperfusion (MCAO/R) rat models were established. Male rats were randomly divided into five groups: a sham-operated group (sham), MCAO/R group, MCAO/R ​+ ​ML385 (Nrf2-specific inhibitor) group, MCAO/R ​+ ​NBP (butylphthalide) group and MCAO/R ​+ ​ML385 ​+ ​NBP group. The effect of butylphthalide on cerebral I/R injury was evaluated using neurological deficit scores. The expression levels of Nrf2, HO-1, glutathione peroxidase 4 (GPX4), acyl-CoA synthetase long-chain family member 4 (ACSL4) and transferrin receptor 1 (TfR1) protein were detected using Western blot. Moreover, the expression levels of GPX4, HO-1 and TfR1 mRNA were determined through real-time fluorescence quantitative reverse transcription polymerase chain reaction. The distribution of Nrf2, HO-1, GPX4 and TfR1 was detected using immunohistochemical staining. The levels of iron and related lipid peroxidation indexes, such as reduced glutathione, reactive oxygen species, malondialdehyde and nitric oxide, were measured using a kit. The changes in mitochondria were observed through transmission electron microscopy. Butylphthalide treatment significantly improved neurological dysfunction, reduced cerebral infarction volume and mitigated histopathological damage in MCAO/R rats. It induced the nuclear translocation of Nrf2 and upregulated HO-1 expression, which was attenuated by ML385. Butylphthalide also attenuated lipid peroxidation, iron accumulation and mitochondrial damage induced by MCAO/R. The expression of GPX4, ACSL4 and TfR1 proteins, as well as their mRNA levels, was modulated through butylphthalide treatment, with improvements observed in mitochondrial morphology. Butylphthalide exerts neuroprotective effects by attenuating neurological dysfunction and ferroptosis in MCAO/R rats through the activation of the Nrf2/HO-1 pathway and inhibition of lipid peroxidation and iron accumulation.

Ferroptosis promotes valproate-induced liver steatosis in vitro and in vivo

Valproic acid (VPA), a common antiepileptic drug, can cause liver steatosis after long-term therapy. However, an impact of ferroptosis on VPA-induced liver steatosis has not been investigated. In the study, treatment with VPA promoted ferroptosis in the livers of mice by elevating ferrous iron (Fe2+) levels derived from the increased absorption by transferrin receptor 1 (TFR1) and the decreased storage by ferritin (FTH1 and FTL), disrupting the redox balance via reduced levels of solute carrier family 7 member 11 (SLC7A11), glutathione (GSH), and glutathione peroxidase 4 (GPX4), and augmenting acyl-CoA synthetase long-chain family member 4 (ACSL4) -mediated lipid peroxide generation, accompanied by enhanced liver steatosis. All the changes were significantly reversed by co-treatment with an iron-chelating agent, deferoxamine mesylate (DFO) and a ferroptosis inhibitor, ferrostatin-1 (Fer-1). Similarly, the increases in Fe2+, TFR1, and ACSL4 levels, as well as the decreases in GSH, GPX4, and ferroportin (FPN) levels, were detected in VPA-treated HepG2 cells. These changes were also attenuated after co-treatment with Fer-1. It demonstrates that ferroptosis promotes VPA-induced liver steatosis through iron overload, inhibition of the GSH-GPX4 axis, and upregulation of ACSL4. It offers a potential therapy targeting ferroptosis for patients with liver steatosis following VPA treatment.

Ferroptosis inhibitor ferrostatin-1 attenuates morphine tolerance development in male rats by inhibiting dorsal root ganglion neuronal ferroptosis.

Ferrostatin-1 and liproxstatin-1, both ferroptosis inhibitors, protect cells. Liproxstatin-1 decreases morphine tolerance. Yet, ferrostatin-1's effect on morphine tolerance remains unexplored. This study aimed to evaluate the influence of ferrostatin-1 on the advancement of morphine tolerance and understand the underlying mechanisms in male rats. This experiment involved 36 adult male Wistar albino rats with an average weight ranging from 220 to 260 g. These rats were categorized into six groups: Control, single dose ferrostatin-1, single dose morphine, single dose ferrostatin-1 + morphine, morphine tolerance (twice daily for five days), and ferrostatin-1 + morphine tolerance (twice daily for five days). The antinociceptive action was evaluated using both the hot plate and tail-flick tests. After completing the analgesic tests, tissue samples were gathered from the dorsal root ganglia (DRG) for subsequent analysis. The levels of glutathione, glutathione peroxidase 4 (GPX4), and nuclear factor erythroid 2-related factor 2 (Nrf2), along with the measurements of total oxidant status (TOS) and total antioxidant status (TAS), were assessed in the tissues of the DRG. After tolerance development, the administration of ferrostatin-1 resulted in a significant decrease in morphine tolerance (P < 0.001). Additionally, ferrostatin-1 treatment led to elevated levels of glutathione, GPX4, Nrf2, and TOS (P < 0.001), while simultaneously causing a decrease in TAS levels (P < 0.001). The study found that ferrostatin-1 can reduce morphine tolerance by suppressing ferroptosis and reducing oxidative stress in DRG neurons, suggesting it as a potential therapy for preventing morphine tolerance.

Role of hypoxia-inducible-factor-1α (HIF-1α) in ferroptosis of adipose tissue during ketosis

Postpartum cows experience lipolysis in adipose tissue due to negative energy balance (NEB), and accumulation of free fatty acids (FFA) leads to metabolic stress in adipose tissue. Ferroptosis is a type of cell death triggered by excessive buildup of iron-dependent lipid peroxides, which is involved in the occurrence and development of various metabolic diseases in nonruminants. However, it is still unclear whether ferroptosis occurs in the adipose tissue of ketotic cows and the regulatory mechanisms behind ferroptosis. Despite multiple studies demonstrating the significant involvement of hypoxia-inducible-factor-1α (HIF-1α) in regulating cellular dysfunction, its specific function in adipose tissue of ketotic dairy cows remains uncertain, particularly its regulation of oxidative stress and ferroptosis. The study aimed to explore the impact of HIF-1α on oxidative stress and ferroptosis in bovine subcutaneous adipose tissue and isolated adipocytes. The adipose tissue of clinical ketosis cows (n = 15) with a serum BHB concentration of 3.13 mM (interquartile range = 0.14) and healthy cows (n = 15) with a serum BHB concentration of and 0.58 mM (interquartile range = 0.13) was collected. The results showed that the concentrations of lipid peroxidation malondialdehyde (MDA), reactive oxygen species (ROS), Fe2+ and total iron were increased in adipose tissue of cows with ketosis, while the contents of glutathione (GSH) were reduced. Furthermore, the protein levels of HIF-1α, heme oxygenase 1 (HMOX1), catalase (CAT), superoxide dismutase 1 (SOD1), acyl-CoA synthetase 4 (ACSL4), and nuclear factor erythroid-derived 2-like 2 (NFE2L2) exhibited higher abundance in adipose tissue obtained from cows with ketosis, whereas the protein abundance of solute carrier family 7 member 11 (SLC7A11), glutamate cysteine ligase catalytic subunit (GCLC), kelch-like ECH-associated protein 1 (KEAP1), glutamate cysteine ligase regulatory subunit (GCLM) and glutathione peroxidase 4 (GPX4) were lower. To simulate the ferroptosis state of adipose tissue in ketotic cows, primary bovine adipocytes were isolated from the adipose tissue of healthy cows and cultured with erastin to construct ferroptosis model. Adipocytes were cultured with either an adenovirus overexpressing HIF-1α or small interfering RNA targeting HIF-for 48 h, followed by exposure to erastin (1 μM) for 24 h. Treatment with erastin led to higher protein abundance of CAT, SOD1, NFE2L2 and HMOX1, while it inhibited the protein expression levels of GCLC, SLC7A11, GCLM, GPX4 and KEAP1. Furthermore, erastin treatment elevated the levels of ROS, MDA, Fe2+, total iron and reduced the content of GSH. The overexpression of HIF-1α reversed the erastin-induced decreases in the protein abundance of GPX4 and SLC7A11, as well as the levels of MDA, ROS, Fe2+ and total iron, while significantly increasing protein abundance and content of CAT, SOD1, NFE2L2, HMOX1, GCLC, GCLM, GPX4, SLC7A11 and GSH. Conversely, the silencing of HIF-1α further exacerbated the erastin-induced levels of MDA, ROS, Fe2+ and total iron, while inhibiting the upregulation of SOD1, CAT, NFE2L2 and HMOX1. Collectively, these findings suggest that activation of HIF-1α may function as an adaptive mechanism to mitigate ferroptosis and alleviate oxidative stress in adipose tissue.

Silibinin promotes healing in spinal cord injury through anti-ferroptotic mechanisms.

Pre-clinical animal experiment. In this study, we investigated therapeutic effects of silibinin in a spinal cord injury (SCI) model. In SCI, loss of cells due to secondary damage mechanisms exceeds that caused by primary damage. Ferroptosis, which is iron-dependent non-apoptotic cell death, is shown to be influential in the pathogenesis of SCI. The study was conducted as an in vivo experiment using a total of 78 adult male/female Sprague Dawley rats. Groups were as follows: Sham, SCI, deferoxamine (DFO) treatment, and silibinin treatment. There were subgroups with follow-up periods of 24 h, 72 h, and 6 weeks in all groups. Malondialdehyde (MDA), glutathione (GSH), and Fe2+ levels were measured by spectrophotometry. Glutathione peroxidase-4 (GPX4), ferroportin (FPN), transferrin receptor (TfR1), and 4-hydroxynonenal (4-HNE)-modified protein levels were assessed by Western blotting. Functional recovery was assessed using Basso-Beattie-Bresnahan test. Silibinin achieved significant suppression in MDA and 4-HNE levels compared to the SCI both in 72-h and 6 weeks group (p < 0.05). GSH, GPX4, and FNP levels were found to be significantly higher in the silibinin 24 h, 72 h, and 6 weeks group compared to corresponding SCI groups (p < 0.05). Significant reduction in iron levels was observed in silibinin treated rats in 72 h and 6 weeks group (p < 0.05). Silibinin substantially suppressed TfR1 levels in 24 h and 72 h groups (p < 0.05). Significant difference among recovery capacities was observed as follows: Silibinin > DFO > SCI (p < 0.05). Impact of silibinin on iron metabolism and lipid peroxidation, both of which are features of ferroptosis, may contribute to therapeutic activity. Within this context, our findings posit silibinin as a potential therapeutic candidate possessing antiferroptotic properties in SCI model. Therapeutic agents capable of effectively and safely mitigating ferroptotic cell death hold the potential to be critical points of future clinical investigations.

MiR-1909-5p targeting GPX4 affects the progression of aortic dissection by modulating nicotine-induced ferroptosis

ObjectiveAortic dissection (AD) is a prevalent and acute clinical catastrophe characterized by abrupt manifestation, swift progression, and elevated fatality rates. Despite smoking being a significant risk factor for AD, the precise pathological process remains elusive. This investigation endeavors to explore the mechanisms by which smoking accelerates AD through ferroptosis induction. MethodologyIn this novel study, we detected considerable endothelial cell death by ferroptosis within the aortic inner lining of both human AD patients with a smoking history and murine AD models induced by β-aminopropionitrile, angiotensin II, and nicotine. Utilizing bioinformatic approaches, we identified microRNAs regulating the expression of the ferroptosis inhibitor Glutathione peroxidase 4 (GPX4). Nicotine's impact on ferroptosis was further assessed in human umbilical vein endothelial cells (HUVECs) through modulation of miR-1909-5p. Additionally, the therapeutic potential of miR-1909-5p antagomir was evaluated in vivo in nicotine-exposed AD mice. FindingsOur results indicate a predominance of ferroptosis over apoptosis, pyroptosis, and necroptosis in the aortas of AD patients who smoke. Nicotine exposure instigated ferroptosis in HUVECs, where the miR-1909-5p/GPX4 axis was implicated. Modulation of miR-1909-5p in these cells revealed its regulatory role over GPX4 levels and subsequent endothelial ferroptosis. In vivo, miR-1909-5p suppression reduced ferroptosis and mitigated AD progression in the murine model. ConclusionsOur data underscore the involvement of the miR-1909-5p/GPX4 axis in the pathogenesis of nicotine-induced endothelial ferroptosis in AD.

Fucoxanthin Induces Ferroptosis in Cancer Cells via Downregulation of the Nrf2/HO-1/GPX4 Pathway.

This study investigated the mechanism by which fucoxanthin acts as a novel ferroptosis inducer to inhibit tongue cancer. The MTT assay was used to detect the inhibitory effects of fucoxanthin on SCC-25 human tongue squamous carcinoma cells. The levels of reactive oxygen species (ROS), mitochondrial membrane potential (MMP), glutathione (GSH), superoxide dismutase (SOD), malondialdehyde (MDA), and total iron were measured. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blotting were used to assess glutathione peroxidase 4 (GPX4), nuclear factor erythroid 2-related factor 2 (Nrf2), Keap1, solute carrier family 7 member 11 (SLC7A11), transferrin receptor protein 1 (TFR1), p53, and heme oxygenase 1 (HO-1) expression. Molecular docking was performed to validate interactions. Compared with the control group, the activity of fucoxanthin-treated SCC-25 cells significantly decreased in a dose- and time-dependent manner. The levels of MMP, GSH, and SOD significantly decreased in fucoxanthin-treated SCC-25 cells; the levels of ROS, MDA, and total iron significantly increased. mRNA and protein expression levels of Keap1, GPX4, Nrf2, and HO-1 in fucoxanthin-treated cells were significantly decreased, whereas levels of TFR1 and p53 were significantly increased, in a concentration-dependent manner. Molecular docking analysis revealed that binding free energies of fucoxanthin with p53, SLC7A11, GPX4, Nrf2, Keap1, HO-1, and TFR1 were below -5 kcal/mol, primarily based on active site hydrogen bonding. Our findings suggest that fucoxanthin can induce ferroptosis in SCC-25 cells, highlighting its potential as a treatment for tongue cancer.

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

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

Tetramethylpyrazine alleviates ferroptosis and promotes functional recovery in spinal cord injury by regulating GPX4/ACSL4

ObjectiveTetramethylpyrazine (TMP) has been demonstrated to alleviate neuronal ferroptosis following spinal cord injury (SCI), thereby promoting neural repair. However, the precise underlying mechanisms remain elusive. MethodsThe SCI model was established using a modified version of Allen's method. TMP (40, 80, 120, and 160 mg/kg) and ras-selective lethal 3 (RSL3) (5 mg/kg) were administered intraperitoneally once daily for 7 days. HE and Nissl staining were employed to examine histomorphology and neurons, respectively. Perls staining was used to identify the distribution of iron. A transmission electron microscope was used to observe the microcosmic morphology of mitochondria. Immunofluorescence staining and Western blot were used to analyze neuronal nuclear protein (NeuN) and glial fibrillary acidic protein (GFAP) surrounding injury sites. Additionally, glutathione peroxidase 4 (GPX4)/NeuN + cells and acyl-CoA synthetase long-chain family member 4 (ACSL4)/NeuN + cells were observed. RT-qPCR was conducted to examine the mRNA expression levels of GPX4 and ACSL4. ELISA were used to quantify the concentrations of GPX4, reactive oxygen species (ROS), L-glutathione (GSH), malondialdehyde (MDA), superoxide dismutase (SOD), and tissue iron. ResultsTMP had an inhibitory effect on the concentrations of tissue iron, ROS, GSH, MDA, and SOD. TMP improved the microcosmic morphology of mitochondria and increased GPX4 level while decreasing that of ACSL4. TMP reduced lesion sizes, enhanced neuronal survival, and inhibited glial scar formation. However, the effect of TMP can be effectively reversed by RSL3. ConclusionTMP alleviates neuronal ferroptosis by regulating the GPX4/ACSL4 axis, thereby protecting the remaining neurons surrounding injury sites and reducing glial scar formation.

Specific Knockdown of the NDUFS4 Gene Reveals Important Roles of Ferroptosis in UVB-induced Photoaging.

Ultraviolet (UV) irradiation significantly contributes to photoaging. Ferroptosis, an iron-dependent cell death mode recently identified, plays a key role in UVB-induced skin photoaging. This study examines the functions and regulatory mechanisms of ferroptosis in this regard. Characterized by increased intracellular iron and reactive oxygen species (ROS), ferroptosis is associated with mitochondrial function and structure. Through RNA sequencing, we identified NADH: ubiquinone oxidoreductase subunit S4 (NDUFS4), a gene implicated in UVB-mediated photoaging, and explored its role in ferroptosis by NDUFS4 knockdown. In vitro, inhibiting NDUFS4 reduced ferroptosis, decreased ROS and matrix metallopeptidase 1 levels, and increased collagen type I alpha 1 chain, glutathione peroxidase 4 (GPX4), ferritin heavy chain 1, and solute carrier family 7 member 11 levels, suggesting a reinforced ferroptosis protective mechanism. Additionally, NDUFS4 regulates ferroptosis via the mitogen-activated protein kinase (MAPK) pathway, with its knockdown reducing p38 and ERK phosphorylation and elevating GPX4 levels, enhancing ferroptosis resistance. Animal experiments supported these findings, demonstrating that Ferrostatin-1, a ferroptosis inhibitor, significantly mitigated UVB-induced skin photoaging and related protein expression. This study uncovers NDUFS4's novel role in regulating ferroptosis and provides new insights into ferroptosis-mediated UVB-induced skin photoaging.

#289 Lipocalin-2 promotes cardiovascular calcification in chronic kidney disease by upregulating STAT3/NCOA4-mediated ferritinophagy and ferroptosis

Abstract Background and Aims Cardiovascular calcification (CVC) is a common complication of chronic kidney disease (CKD) and contributes to cardiovascular morbidity and mortality without any effective therapies. To date, the underlying mechanism of CKD-CVC has not been elucidated. Recent studies suggest that ferroptosis is a novel programmed cell death that may play a role in the process of CKD-CVC, but the mechanism is largely unclear. Ferritinophagy is an important inducer of ferroptosis that is regulated by nuclear receptor coactivator 4 (NCOA4). However, the relationship between ferritinophagy and CKD-CVC has not been explored. Lipocalin-2 (LCN2) is an iron-trafficking protein that has been associated with both osteogenesis and ferroptosis, but the exact role and molecular mechanism of LCN2 in CKD-CVC needs to be explored. Method A cross-sectional clinical study was utilized to examine the association between LCN2 expression and CKD-CVC in serum and calcified radial arteries of CKD patients. LCN2 knockout mice, their wild type littermates and mice infected with VSMCs-targeted adeno-associated virus encoding LCN2 gene or negative control gene were all fed by the high adenine and phosphate diet to induce CKD-CVC.VSMCs transfected with LCN2-overexpressing lentivirus, LCN2-shRNA lentivirus or LCN2 siRNA and recombinant LCN2 stimulated VSMCs were treated under the condition of calcifying medium to investigate the role of LCN2 in CKD-CVC in vitro. Cardiovascular calcification was evaluated by Von-kossa staining and tissue calcium content assay. VSMCs calcification were checked by the Alizarin Red Staining and cellular calcium content assay. Cellular reactive oxygen species (ROS) were measured by the DCFDA assay. Lipid peroxidation was measured by the fluorescence of the fatty acid analog C11-BODIPY581/591 probe. Intracellular labile ferrous iron levels were measured by fluorescence of Phen Green SK probe and ferro-orange probe. Transmission electron microscopy was also used to examine mitochondrial change of ferroptosis. Results The cross-sectional study identified that LCN2 levels in serum and radial arteries were significantly increased as the severity of CKD-CVC increased. High adenine and phosphate diet intake provokes renal fibrosis and cardiovascular calcification in vivo. In vitro, five-days high phosphate sodium stimulation induced calcium deposition and osteoblastic trans differentiation of VSMCs. Meanwhile, high phosphate also increased the levels of ferroptosis in VSMCs as evidenced by decreased cell viability, iron and ROS accumulation, upregulated PTGS2 and MDA levels, reduced glutathione peroxidase 4 (GPX4) levels and significantly mitochondrial damage in VSMCs. Intriguingly, calcium deposition in VSMCs could be reversed by the ferroptosis inhibitor ferrostatin-1. LCN2 expression was significantly upregulated both in the aorta of mice and calcified VSMCs. Compared with WT mice, deletion of LCN2 inhibited cardiovascular calcification whereas VSMC-targeted LCN2 overexpression aggravated CKD-CVC. Consistently, LCN2 knockdown also alleviated calcium deposition of VSMCs. Meanwhile, inhibition of ferroptosis were observed after LCN2 silencing as evidenced by decreased ferrous and lipid oxidation while increased levels of GPX4. Mechanically, we demonstrated high phosphate increased the protein level of NCOA4 and downregulated FTH1, which was reversed by depletion of LCN2. Knockdown of NCOA4 partly alleviated the ferritin reduction, ferroptosis, and calcification in VSMCs, indicating that NCOA4-mediated ferritinophagy was required for VSMCs calcification. Furthermore, we found that the recombinant LCN2 treatment significantly upregulated phosphorylated STAT3. STAT3 signaling inhibitor abolished the recombinant LCN2 induced NCOA4 upregulation and calcification in VSMCs. Conclusion Our findings indicate that the pro-calcific effect of high phosphate is due to VSMCs ferroptosis mediated by LCN2 upregulation. LCN2 silencing alleviates CKD-CVC by suppressing the STAT3/ NCOA4/FTH1 signaling mediated ferritinophagy. LCN2 could serve as a candidate therapeutic strategy for CKD-CVC.