The effect of a rotating magnetic field on the antioxidant system in healthy volunteers - preliminary study.

Oxidative stress is characterized by an excessive concentration of reactive oxygen species (ROS) resulting from a disturbance in the balance between ROS production and their removal by antioxidant systems (SOD, CAT, GPx). Prolonged and intense oxidative stress can cause various forms of damage to cells, which markers are total antioxidant capacity (TAC), reactive oxygen species modulator (ROMO1), and malondialdehyde (MDA). It has been demonstrated that magnetic fields can positively affect human health, for example, by reducing oxidative stress. Determination of the effect of a rotating magnetic field (RMF) on the activity/concentration of selected oxidative stress markers. A group of 30 healthy volunteers (15 women and 15 men) (mean age 24.8 ± 5.1) in the study classified into the following groups: internal control group (CG);1 h 25 Hz (samples placed in the field for one hour at 25 Hz); 3 h 25 Hz (samples placed in the field for 3 h at 25 Hz), the 1 h 50 Hz group ( placed in RMF for an hour at 50 Hz), and a group of 3 h 50 Hz (samples placed in the field for 3 h at 50 Hz). Serum samples were collected in K2EDTA tubes.. The magnetic induction value obtained for RMF is 37.06 mT and 42.64 mT.Activity/concentration of selected oxidative stress markers was analyzed by ELISA. The influence of an RMF on the activity/concentration of SOD, MDA, TAC, and ROMO1 was demonstrated (p < 0.001; p = 0.0013; p < 0.001; p = 0.003). The RFM can reduce oxidative stress, as evidenced by higher SOD and CAT activities in the CG than in samples placed in the RFM. Prolonged exposure to the RFM at 50 Hz increased the TAC level, indicating an intensification of oxidative stress in these samples. The optimal conditions for staying in the RFM (reducing oxidative stress) are 1 h 50 Hz for SOD and MDA; 3 h 25 Hz for CAT and TAC. In the case of ROMO1, it is stated that 1 h 25 Hz are the optimal conditions for no increased production of ROS.

Dipeptidase 1 promotes ferroptosis in renal tubular epithelial cells in diabetic nephropathy via inhibition of the GSH/GPX4 axis.

Renal tubular injury is an important pathological change associated with diabetic nephropathy (DN), in which ferroptosis of renal tubular epithelial cells is critical to its pathogenesis. Inhibition of the glutathione/glutathione peroxidase 4 (GSH/GPX4) axis is the most important mechanism in DN tubular epithelial cell ferroptosis, but the underlying reason for this is unclear. Our biogenic analysis showed that a zinc-dependent metalloproteinase, dipeptidase 1 (DPEP1), is associated with DN ferroptosis. Here, we investigated the role and mechanism of DPEP1 in DN tubular epithelial cell ferroptosis. DPEP1 upregulation was observed in the renal tubular epithelial cells of DN patients and model mice, as well as in HK-2 cells stimulated with high glucose. Furthermore, the level of DPEP1 upregulation was associated with the degree of tubular injury in DN patients and HK-2 cell ferroptosis. Mechanistically, knocking down DPEP1 expression could alleviate the inhibition of GSH/GPX4 axis and reduce HK-2 cell ferroptosis levels in a high glucose environment. HK-2 cells with stable DPEP1 overexpression also showed GSH/GPX4 axis inhibition and ferroptosis, but blocking the GSH/GPX4 axis could mitigate these effects. Additionally, treatment with cilastatin, a DPEP1 inhibitor, could ameliorate GSH/GPX4 axis inhibition and relieve ferroptosis and DN progression in DN mice. These results revealed that DPEP1 can promote ferroptosis in DN renal tubular epithelial cells via inhibition of the GSH/GPX4 axis.

Electroacupuncture Inhibits Neural Ferroptosis in Rat Model of Traumatic Brain Injury via Activating System Xc-/GSH/GPX4 Axis.

BACKGROUND: Ferroptosis is an iron-dependent regulating programmed cell death discovered recently that has been receiving much attention in traumatic brain injury (TBI). xCT, a major functional subunit of Cystine/glutamic acid reverse transporter (System Xc-), promotes cystine intake and glutathione biosynthesis, thereby protecting against oxidative stress and ferroptosis. OBJECTIVE: The intention of this research was to verify the hypothesis that electroacupuncture (EA) exerted an anti-ferroptosis effect via an increase in the expression of xCT and activation of the System Xc-/GSH/GPX4 axis in cortical neurons of TBI rats. METHODS: After the TBI rat model was prepared, animals received EA treatment at GV20, GV26, ST36 and PC6, for 15min. The xCT inhibitor Sulfasalazine (SSZ) was administered 2h prior to model being prepared. The degree of neurological impairment was evaluated by means of TUNEL staining and the modified neurological severity score (mNSS). Specific indicators of ferroptosis (Ultrastructure of mitochondria, Iron and ROS) were detected by transmission electron microscopy (TEM), Prussian blue staining (Perls stain) and flow cytometry (FCM), respectively. GSH synthesis and metabolism-related factors in the content of the cerebral cortex were detected by an assay kit. Real-time quantitative PCR (RT-QPCR), Western blot (WB), and immunofluorescence (IF) were used for detecting the expression of System Xc-/GSH/GPX4 axisrelated proteins in injured cerebral cortex tissues. RESULTS: EA successfully relieved nerve damage within 7 days after TBI, significantly inhibited neuronal ferroptosis, upregulated the expression of xCT and System Xc-/GSH/GPX4 axis forward protein and promoted glutathione (GSH) synthesis and metabolism in the injured area of the cerebral cortex. However, aggravation of nerve damage and increased ferroptosis effect were found in TBI rats injected with xCT inhibitors. CONCLUSIONS: EA inhibits neuronal ferroptosis by up-regulated xCT expression and by activating System Xc-/GSH/GPX4 axis after TBI, confirming the relevant theories regarding the EA effect in treating TBI and providing theoretical support for clinical practice.

[Fuyu Decoction ameliorates myocardial fibrosis in rat model of heart failure by regulating Nrf2/GPX4-mediated ferroptosis].

This study aims to investigate the effect and mechanism of Fuyu Decoction(FYD) in the treatment of myocardial fibrosis in the rat model of heart failure(HF). Sixty Wistar rats were randomized into a modeling group(n=50) and a sham group(n=10). A post-myocardial infarction HF model was established by ligating the left anterior descending coronary artery in rats. The successfully modeled rats were assigned into model, low-dose(2.5 g·kg~(-1)) FYD(FYD-L), high-dose(5.0 g·kg~(-1)) FYD(FYD-H), and FYD+Nrf2 inhibitor(ML385, 30 mg·kg~(-1)) groups(n=10). FYD was administrated by gavage and ML385 by intraperitoneal injection. The rats in the sham and model groups were administrated with equal amounts of normal saline by gavage. After 8 weeks of intervention, the cardiac function indicators were measured, and the myocardial tissue morphology and collagen deposition were observed. The positive expression of collagens Ⅰ and Ⅲ, apoptosis, and oxidative stress were examined, and the levels of Fe~(2+) and reactive oxygen species(ROS) were determined. The protein levels of nuclear factor erythroid 2-related factor 2(Nrf2), solute carrier family 7 member 11(SLC7A11), glutathione peroxidase 4(GPX4), and acyl-coenzyme A synthase long chain family member 4(ACSL4) in the myocardial tissue were determined. Compared with sham group, the model group showed decreased left ventricular ejection fraction(LVEF) and left ventricular fractional shortening(LVFS), increased left ventricular end internal dimension in systole(LVIDs), left ventricular internal diameter in diastole(LVIDd), and myocardial collagen deposition, positive expression of collagens Ⅰ and Ⅲ, elevated apoptosis rate and malondialdehyde(MDA), Fe~(2+), and ROS levels, lowered superoxide dismutase(SOD) and glutathione peroxidase(GSH) levels, down-regulated protein levels of Nrf2, SLC7A11, and GPX4, and up-regulated protein level of ACSL4. Compared with the model group, the above indicators were restored by FYD. Moreover, ML385 reversed the protective effect of FYD on myocardial fibrosis in HF rats. In conclusion, FYD can inhibit ferroptosis by activating the Nrf2/GPX4 pathway, thereby ameliorating myocardial fibrosis in HF rats.

GPX4, ferroptosis, and diseases.

GPX4 (Glutathione peroxidase 4) serves as a crucial intracellular regulatory factor, participating in various physiological processes and playing a significant role in maintaining the redox homeostasis within the body. Ferroptosis, a form of iron-dependent non-apoptotic cell death, has gained considerable attention in recent years due to its involvement in multiple pathological processes. GPX4 is closely associated with ferroptosis and functions as the primary inhibitor of this process. Together, GPX4 and ferroptosis contribute to the pathophysiology of several diseases, including sepsis, nervous system diseases, ischemia reperfusion injury, cardiovascular diseases, and cancer. This review comprehensively explores the regulatory roles and impacts of GPX4 and ferroptosis in the development and progression of these diseases, with the aim of providing insights for identifying potential therapeutic strategies in the future.

PTGER3 knockdown inhibits the vulnerability of triple-negative breast cancer to ferroptosis.

Prostaglandin E receptor 3 (PTGER3) is involved in a variety of biological processes in the human body and is closely associated with the development and progression of a variety of cancer types. However, the role of PTGER3 in triple-negative breast cancer (TNBC) remains unclear. In the present study, low PTGER3 expression was found to be associated with poor prognosis in TNBC patients. PTGER3 plays a crucial role in regulating TNBC cell invasion, migration, and proliferation. Upregulation of PTGER3 weakens the epithelial-mesenchymal phenotype in TNBC and promotes ferroptosis both in vitro and in vivo by repressing glutathione peroxidase 4 (GPX4) expression. On the other hand, downregulation of PTGER3 inhibits ferroptosis by increasing GPX4 expression and activating the PI3K-AKT pathway. Upregulation of PTGER3 also enhances the sensitivity of TNBC cells to paclitaxel. Overall, this study has elucidated critical pathways in which low PTGER3 expression protects TNBC cells from undergoing ferroptosis, thereby promoting its progression. PTGER3 may thus serve as a novel and promising biomarker and therapeutic target for TNBC.

Downregulation of GPX8 in hepatocellular carcinoma: impact on tumor stemness and migration.

PURPOSE: GPX8, which is found in the endoplasmic reticulum lumen, is a member of the Glutathione Peroxidases (GPXs) family. Its role in hepatocellular carcinoma (HCC) is unknown. METHODS: Immunohistochemical staining was used to detect the protein levels of GPX8 in HCC tissue microarrays. A short hairpin RNA lentivirus was used to knock down GPX8, and the main signaling pathways were investigated using transcriptome sequencing and a phosphorylated kinase array. The sphere formation assays, cloning-formation assays and cell migration assays were used to evaluate the stemness and migration ability of HCC cells. Identifying the GPX8-interacting proteins was accomplished through immunoprecipitation and protein mass spectrometry. RESULTS: The GPX8 protein levels were downregulated in HCC patients. Low expression of GPX8 protein was related to early recurrence and poor prognosis in HCC patients. GPX8 knockdown could enhance the stemness and migration ability of HCC cells. Consistently, Based on transcriptome analysis, multiple signaling pathways that include the PI3K-AKT and signaling pathways that regulate the pluripotency of stem cells, were activated after GPX8 knockdown. The downregulation of GPX8 could increase the expression of the tumor stemness markers KLF4, OCT4, and CD133. The in vivo downregulation of GPX8 could also promote the subcutaneous tumor-forming and migration ability of HCC cells. MK-2206, which is a small-molecule inhibitor of AKT, could reverse the tumor-promoting effects both in vivo and in vitro. We discovered that GPX8 and the 71-kDa heat shock cognate protein (Hsc70) have a direct interaction. The phosphorylation of AKT encouraged the translocation of Hsc70 into the nucleus and the expression of the PI3K p110 subunit, thereby increasing the downregulation of GPX8. CONCLUSION: The findings from this study demonstrate the anticancer activity of GPX8 in HCC by inactivating the Hsc70/AKT pathway. The results suggest a possible therapeutic target for HCC.

Relationship of mTORC1 and ferroptosis in tumors.

Ferroptosis is a novel form of programmed death, dependent on iron ions and oxidative stress, with a predominant intracellular form of lipid peroxidation. In recent years, ferroptosis has gained more and more interest of people in the treatment mechanism of targeted tumors. mTOR, always overexpressed in the tumor, and controlling cell growth and metabolic activities, has an important role in both autophagy and ferroptosis. Interestingly, the selective types of autophay plays an important role in promoting ferroptosis, which is related to mTOR and some metabolic pathways (especially in iron and amino acids). In this paper, we list the main mechanisms linking ferroptosis with mTOR signaling pathway and further summarize the current compounds targeting ferroptosis in these ways. There are growing experimental evidences that targeting mTOR and ferroptosis may have effective impact in many tumors, and understanding the mechanisms linking mTOR to ferroptosis could provide a potential therapeutic approach for tumor treatment.

Overexpression of TNFSF11 reduces GPX4 levels and increases sensitivity to ferroptosis inducers in lung adenocarcinoma.

BACKGROUND: Lung adenocarcinoma (LUAD), the most common and lethal subtype of lung cancer, continues to be a major health concern worldwide. Despite advances in targeted and immune therapies, only a minority of patients derive substantial benefits. As a result, the urgent need for novel therapeutic strategies to improve lung cancer treatment outcomes remains undiminished. METHODS: In our study, we employed the TIMER database to scrutinize TNFSF11 expression across various cancer types. We further examined the differential expression of TNFSF11 in normal and tumor tissues utilizing the TCGA-LUAD dataset and tissue microarray, and probed the associations between TNFSF11 expression and clinicopathological parameters within the TCGA-LUAD dataset. We used the GSE31210 dataset for external validation. To identify genes strongly linked to TNFSF11, we engaged LinkedOmics and conducted a KEGG pathway enrichment analysis using the WEB-based Gene SeT AnaLysis Toolkit. Moreover, we investigated the function of TNFSF11 through gene knockdown or overexpression approaches and explore its function in tumor cells. The therapeutic impact of ferroptosis inducers in tumors overexpressing TNFSF11 were also investigated through in vivo and in vitro experiments. Through these extensive analyses, we shed light on the potential role of TNFSF11 in lung adenocarcinoma, underscoring potential therapeutic targets for this malignancy. RESULTS: This research uncovers the overexpression of TNFSF11 in LUAD patients and its inverse correlation with peroxisome-related enzymes. By utilizing gene knockdown or overexpression assays, we found that TNFSF11 was negatively associated with GPX4. Furthermore, cells with TNFSF11 overexpression were relatively more sensitive to the ferroptosis inducers. CONCLUSIONS: Our research has provided valuable insights into the role of TNFSF11, revealing its negative regulation of GPX4, which could be influential in crafting therapeutic strategies. These findings set the stage for further exploration into the mechanisms underpinning the relationship between TNFSF11 and GPX4, potentially opening up new avenues for precision medicine in the treatment of LUAD.

GPX4 degradation contributes to fluoride-induced neuronal ferroptosis and cognitive impairment via mtROS-chaperone-mediated autophagy.

Ferroptosis is a newly recognized type of programmed cell death that is implicated in the pathophysiological process of neurological disorders. Our previous studies have revealed that exposure to high concentrations of fluoride for long periods of time induces hippocampal neural injury and cognitive deficits. However, whether ferroptosis is involved in fluoride-induced neuronal death and the underlying mechanism remain unknown. In this study, the results indicated that exposure to high fluoride triggered ferroptosis in SH-SY5Y cells and in the hippocampus of mice. Fluoride exposure accelerated the lysosomal degradation of GPX4 and led to neuronal ferroptosis, while GPX4 overexpression protected SH-SY5Y cells against fluoride-induced neurotoxicity. Intriguingly, the enhanced chaperone-mediated autophagy (CMA) induced by fluoride stimulation was responsible for GPX4 degradation because the inhibition of CMA activity by LAMP2A knockdown effectively prevented fluoride-induced GPX4 loss. Furthermore, mitochondrial ROS (mtROS) accumulation caused by fluoride contributed to CMA activation-mediated GPX4 degradation and subsequent neuronal ferroptosis. Notably, the ferroptosis-specific inhibitor ferrostatin-1 (Fer-1) or the ROS scavenger N-acetyl-L-cysteine (NAC) alleviated fluoride-evoked hippocampal neuronal death and synaptic injury as well as cognitive deficits in mice. The present studies indicates that ferroptosis is a novel mechanism of fluoride-induced neurotoxicity and that chronic fluoride exposure facilitates GPX4 degradation via mtROS chaperone-mediated autophagy, leading to neuronal ferroptosis and cognitive impairment.

Resveratrol protects cardiomyocytes against ischemia/reperfusion-induced ferroptosis via inhibition of the VDAC1/GPX4 pathway.

The present study aimed to explore how resveratrol (Res) confers myocardial protection by attenuating ferroptosis. In vivo and in vitro myocardial ischemia/reperfusion injury (MIRI) models were established, with or without Res pretreatment. The results showed that Res pretreatment effectively attenuated MIRI, as evidenced by increased cell viability, reduced lactate dehydrogenase activity, decreased infarct size, and maintained cardiac function. Moreover, Res pretreatment inhibited MIRI-induced ferroptosis, as shown by improved mitochondrial integrity, increased glutathione level, decreased prostaglandin-endoperoxide synthase 2 level, inhibited iron overload, and abnormal lipid peroxidation. Of note, Res pretreatment decreased or increased voltage-dependent anion channel 1/glutathione peroxidase 4 (VDAC1/GPX4) expression, which was increased or decreased via anoxia/reoxygenation (A/R) treatment, respectively. However, the overexpression of VDAC1 via pAd/VDAC1 and knockdown of GPX4 through Si-GPX4 reversed the protective effect of Res in A/R-induced H9c2 cells, whereas the inhibition of GPX4 with RSL3 abolished the protective effect of Res on mice treated with ischemia/reperfusion.Interestingly, knockdown of VDAC1 by Si-VDAC1 promoted the protective effect of Res on A/R-induced H9c2 cells and the regulation of GPX4. Finally, the direct interaction between VDAC1 and GPX4 was determined using co-immunoprecipitation. In conclusion, Res pretreatment could protect the myocardium against MIRI-induced ferroptosis via the VDAC1/GPX4 signaling pathway.

USP8-governed GPX4 homeostasis orchestrates ferroptosis and cancer immunotherapy.

Ferroptosis is an iron-dependent type of regulated cell death resulting from extensive lipid peroxidation and plays a critical role in various physiological and pathological processes. However, the regulatory mechanisms for ferroptosis sensitivity remain incompletely understood. Here, we report that homozygous deletion of Usp8 (ubiquitin-specific protease 8) in intestinal epithelial cells (IECs) leads to architectural changes in the colonic epithelium and shortens mouse lifespan accompanied by increased IEC death and signs of lipid peroxidation. However, mice with heterozygous deletion of Usp8 in IECs display normal phenotype and become resistant to azoxymethane/dextran sodium sulfate-induced colorectal tumorigenesis. Mechanistically, USP8 interacts with and deubiquitinates glutathione peroxidase 4 (GPX4), leading to GPX4 stabilization. Thus, USP8 inhibition destabilizes GPX4 and sensitizes cancer cells to ferroptosis in vitro. Notably, USP8 inhibition in combination with ferroptosis inducers retards tumor growth and enhances CD8+ T cell infiltration, which potentiates tumor response to anti-PD-1 immunotherapy in vivo. These findings uncover that USP8 counteracts ferroptosis by stabilizing GPX4 and highlight targeting USP8 as a potential therapeutic strategy to boost ferroptosis for enhancing cancer immunotherapy.

Interferon-α stimulates DExH-box helicase 58 to prevent hepatocyte ferroptosis.

BACKGROUND: Liver ischemia/reperfusion (I/R) injury is usually caused by hepatic inflow occlusion during liver surgery, and is frequently observed during war wounds and trauma. Hepatocyte ferroptosis plays a critical role in liver I/R injury, however, it remains unclear whether this process is controlled or regulated by members of the DEAD/DExH-box helicase (DDX/DHX) family. METHODS: The expression of DDX/DHX family members during liver I/R injury was screened using transcriptome analysis. Hepatocyte-specific Dhx58 knockout mice were constructed, and a partial liver I/R operation was performed. Single-cell RNA sequencing (scRNA-seq) in the liver post I/R suggested enhanced ferroptosis by Dhx58hep-/-. The mRNAs and proteins associated with DExH-box helicase 58 (DHX58) were screened using RNA immunoprecipitation-sequencing (RIP-seq) and IP-mass spectrometry (IP-MS). RESULTS: Excessive production of reactive oxygen species (ROS) decreased the expression of the IFN-stimulated gene Dhx58 in hepatocytes and promoted hepatic ferroptosis, while treatment using IFN-α increased DHX58 expression and prevented ferroptosis during liver I/R injury. Mechanistically, DHX58 with RNA-binding activity constitutively associates with the mRNA of glutathione peroxidase 4 (GPX4), a central ferroptosis suppressor, and recruits the m6A reader YT521-B homology domain containing 2 (YTHDC2) to promote the translation of Gpx4 mRNA in an m6A-dependent manner, thus enhancing GPX4 protein levels and preventing hepatic ferroptosis. CONCLUSIONS: This study provides mechanistic evidence that IFN-α stimulates DHX58 to promote the translation of m6A-modified Gpx4 mRNA, suggesting the potential clinical application of IFN-α in the prevention of hepatic ferroptosis during liver I/R injury.

Salvia miltiorrhiza suppresses cardiomyocyte ferroptosis after myocardial infarction by activating Nrf2 signaling.

ETHNOPHARMACOLOGICAL RELEVANCE: Ferroptosis, a recently identified non-apoptotic form of cell death reliant on iron, is distinguished by an escalation in lipid reactive oxygen species (ROS) that are iron-dependent. This phenomenon has a strong correlation with irregularities in iron metabolism and lipid peroxidation. Salvia miltiorrhiza Bunge (DS), a medicinal herb frequently utilized in China, is highly esteemed for its therapeutic effectiveness in enhancing blood circulation and ameliorating blood stasis, particularly during the treatment of cardiovascular diseases (CVDs). Numerous pharmacological studies have identified that DS manifests antioxidative stress effects as well as inhibits lipid peroxidation. However, ambiguity persists regarding the potential of DS to impede ferroptosis in cardiomyocytes and subsequently improve myocardial damage post-myocardial infarction (MI). AIM OF THE STUDY: The present work focused on investigating whether DS could be used to prevent the ferroptosis of cardiomyocytes and improve post-MI myocardial damage. MATERIALS AND METHODS: In vivo experiments: Through ligation of the left anterior descending coronary artery, we constructed both a wild-type (WT) and NF-E2 p45-related factor 2 knockout (Nrf2-/-) mouse model of MI. Effects of DS and ferrostatin-1 (Fer-1) on post-MI cardiomyocyte ferroptosis were examined through detecting ferroptosis and myocardial damage-related indicators as well as Nrf2 signaling-associated protein levels. In vitro experiments: Erastin was used for stimulating H9C2 cardiomyocytes to construct an in vitro ferroptosis cardiomyocyte model. Effects of DS and Fer-1 on cardiomyocyte ferroptosis were determined based on ferroptosis-related indicators and Nrf2 signaling-associated protein levels. Additionally, inhibitor and activator of Nrf2 were used for confirming the impact of Nrf2 signaling on DS's effect on cardiomyocyte ferroptosis. RESULTS: In vivo: In comparison to the model group, DS suppressed ferroptosis in cardiomyocytes post-MI and ameliorated myocardial damage by inducing Nrf2 signaling-related proteins (Nrf2, xCT, GPX4), diminishing tissue ferrous iron and malondialdehyde (MDA) content. Additionally, it enhanced glutathione (GSH) levels and total superoxide dismutase (SOD) activity, effects that are aligned with those of Fer-1. Moreover, the effect of DS on alleviating cardiomyocyte ferroptosis after MI could be partly inhibited through Nrf2 knockdown. In vitro: Compared with the erastin group, DS inhibited cardiomyocyte ferroptosis by promoting the expression of Nrf2 signaling-related proteins, reducing ferrous iron, ROS, and MDA levels, but increasing GSH content and SOD activity, consistent with the effect of Fer-1. Additionally, Nrf2 inhibition increased erastin-mediated ferroptosis of cardiomyocytes through decreasing Nrf2 signaling-related protein expressions. Co-treatment with DS and Nrf2 activator failed to further enhance the anti-ferroptosis effect of DS. CONCLUSION: MI is accompanied by cardiomyocyte ferroptosis, whose underlying mechanism is probably associated with Nrf2 signaling inhibition. DS possibly suppresses ferroptosis of cardiomyocytes and improves myocardial damage after MI through activating Nrf2 signaling.

Human mesenchymal stem cells derived exosomes improve ovarian function in chemotherapy-induced premature ovarian insufficiency mice by inhibiting ferroptosis through Nrf2/GPX4 pathway.

BACKGROUND: Chemotherapy exposure has become a main cause of premature ovarian insufficiency (POI). This study aimed to evaluate the role and molecular mechanism of human umbilical cord mesenchymal stem cell-derived exosomes (hUMSC-Exos) in ovarian function protection after chemotherapy. METHODS: hUMSC-Exos were applied to cyclophosphamide-induced premature ovarian insufficiency mice and human ovarian granulosa tumor cells (KGN) to determine their effects on follicular development and granulosa cell apoptosis. Evaluation was done for iron ion and reactive oxygen species (ROS) production, lipid peroxidation levels, and changes in iron death-related molecules (nuclear factor (erythroid-derived 2)-like 2 (Nrf2), Glutathione Peroxidase enzyme 4 (GPX4), and Solute carrier family 7 member 11 cystine glutamate transporter (SLC7A11; xCT)). Furthermore, rescue experiments using an Nrf2 inhibitor were performed to assess the therapeutic effects of hUMSC-Exos on granulosa cells. RESULTS: hUMSC-Exos promoted ovarian hormone levels and primary follicle development in POI mice and reduced granulosa cell apoptosis. After hUMSC-Exos treatment, the ROS production, free iron ions and lipid peroxidation levels of granulosa cells decreased, and the iron death marker proteins Nrf2, xCT and GPX4 also decreased. Furthermore, the Nrf2 inhibitor ML385 significantly attenuated the effects of hUMSC-Exos on granulosa cells. CONCLUSION: hUMSC-Exos inhibit ferroptosis and protect against CTX-induced ovarian damage and granulosa cell apoptosis through the Nrf2/GPX4 signaling pathway, revealing a novel mechanism of hUMSC-Exos in POI therapy.

Icariin inhibits chondrocyte ferroptosis and alleviates osteoarthritis by enhancing the SLC7A11/GPX4 signaling.

BACKGROUND: Chondrocyte ferroptosis plays a critical role in the pathogenesis of osteoarthritis (OA), regulated by the SLC7A11/GPX4 signaling pathway. Icariin (ICA), a flavonoid glycoside, exhibits strong anti-inflammatory and antioxidant activities. This study investigated whether ICA could modulate the SLC7A11/GPX4 signaling to inhibit chondrocyte ferroptosis and alleviate OA. PURPOSE: The objective was to explore the impact of ICA on chondrocyte ferroptosis in OA and its modulation of the SLC7A11/GPX4 signaling pathway. METHODS: The anti-ferroptosis effects of ICA were evaluated in an interleukin-1ß (IL-1ß)-treated SW1353 cell model, using Ferrostatin-1 (Fer-1) and Erastin (Era) as ferroptosis inhibitor and inducer, respectively, along with GPX4 knockdown via lentivirus-based shRNA. Additionally, the therapeutic efficacy of ICA on OA-related articular cartilage damage was assessed in rats through histopathology and immunohistochemistry (IHC). RESULTS: IL-1ß treatment upregulated the expression of OA-associated matrix metalloproteinases (MMP3 and MMP1), a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS-5), and increased intracellular ROS, lipid ROS, and MDA levels while downregulating collagen II and SOX9 expression in SW1353 cells. ICA treatment countered the IL-1ß-induced upregulation of MMPs and ADAMTS-5, restored collagen II and SOX9 expression, and reduced intracellular ROS, lipid ROS, and MDA levels. Furthermore, IL-1ß upregulated P53 but downregulated SLC7A11 and GPX4 expression in SW1353 cells, effects that were mitigated by ICA or Fer-1 treatment. Significantly, ICA also alleviated Era-induced ferroptosis, whereas it had no effect on GPX4-silenced SW1353 cells. In vivo, ICA treatment reduced articular cartilage damage in OA rats by partially restoring collagen II and GPX4 expression, inhibiting cartilage extracellular matrix (ECM) degradation and chondrocyte ferroptosis. CONCLUSION: ICA treatment mitigated chondrocyte ferroptosis and articular cartilage damage by enhancing the SLC7A11/GPX4 signaling, suggesting its potential as a therapeutic agent for OA interventions.

Selenium maintains intestinal epithelial cells to activate M2 macrophages against deoxynivalenol injury.

Selenium (Se) is indispensable in alleviating various types of intestinal injuries. Here, we thoroughly investigated the protective effect of Se on the regulation of the epithelial cell-M2 macrophages pathway in deoxynivalenol (DON)-induced intestinal damage. In the present study, Se has positive impacts on gut health by improving gut barrier function and reducing the levels of serum DON in vivo. Furthermore, our study revealed that Se supplementation increased the abundances of GPX4, p-PI3K, and AKT, decreased the levels of 4-HNE and inhibited ferroptosis. Moreover, when mice were treated with DON and Fer-1(ferroptosis inhibitor), ferroptosis was suppressed and PI3K/AKT pathway was activated. These results indicated that GPX4-PI3K/AKT-ferroptosis was a predominant pathway in DON-induced intestinal inflammation. Interestingly, we discovered that both the number of M2 anti-inflammatory macrophages and the levels of CSF-1 decreased while the pro-inflammatory cytokine IL-6 increased in the intestine and MODE-K cells supernatant. Therefore, Se supplementation activated the CSF-1-M2 macrophages axis, resulting in a decrease in IL-6 expression and an enhancement of the intestinal anti-inflammatory capacity. This study provides novel insights into how intestinal epithelial cells regulate the CSF-1-M2 macrophage pathway, which is essential in maintaining intestinal homeostasis confer to environmental hazardous stimuli.

Aristolochic acid induces acute kidney injury through ferroptosis.

Aristolochic acid (AA)-induced acute kidney injury (AKI) presents with progressive decline in renal function and rapid progression to end-stage renal disease. Among the multiple mechanisms identified in AKI, ferroptosis has been shown to be involved in various forms of AKI. But few studies have elucidated the role of ferroptosis in AA-induced AKI. In this study, we investigated the role of ferroptosis in AA-induced acute renal tubular injury in vivo and in vitro. Mice with acute aristolochic acid nephropathy showed increased malondialdehyde levels, aggravated lipid peroxidation, decreased superoxide dismutase activity, and glutathione depletion. The expression of glutathione peroxidase 4 was decreased and the expression of acyl-CoA synthetase long-chain family member 4 was increased. Inhibition of ferroptosis by ferrostatin-1 significantly improved the renal function, reduced histopathological lesions, partially alleviated lipid peroxidation, and restored the antioxidant capacity. In vitro studies also revealed that AA significantly reduced cell viability, induced reactive oxygen species production, increased intracellular iron level and decreased ferroptosis-related protein expression. Inhibition of ferroptosis significantly increased cell viability and attenuated AA-induced renal tubular epithelial cell injury. It is suggested that ferroptosis plays an important role in AA-induced acute tubular injury. And inhibition of ferroptosis may exert renoprotective effects possibly by preventing lipid peroxidation, restoring the antioxidant activity or regulating iron metabolism.

Baicalein improves renal interstitial fibrosis by inhibiting the ferroptosis in vivo and in vitro.

Evidence indicates that Baicalein can ameliorate renal interstitial fibrosis by inducing myofibroblast apoptosis and inhibit the RLS3-induced ferroptosis in melanocytes. However, the relationship between renal interstitial fibrosis and anti-ferroptosis affected by Baicalein remains unclear. In our study, the anti-fibrosis and anti-ferroptosis effects of Baicalein were assessed in a rat model induced by the UUO method in vivo, and the effects of Baicalein on Erastin-induced ferroptosis of renal MPC-5 cells were examined by Western blot of fibrosis-related and ferroptosis-related proteins in vitro. In the UUO-induced rat model, Baicalein decreased kidney weight loss, improved renal function assessed the biomarks of urinary albumin excretion, serum creatine, and BUN levels, and reduced renal tubular injury. Furthermore, Baicalein inhibited renal ferroptosis by reducing ROS and MDA levels and increasing SOD and GSH levels in the UUO rat model. In addition, Baicalein potently reduced the expression of fibrosis-related proteins such as TGF-ß1, a-SMA, and Smad-2 to prevent renal interstitial fibrosis, and increased the expression of ferroptosis-related proteins such as SLC7A11, GPX4, and FTH to inhibit ferroptosis both in vitro and in vivo. Taken together, Baicalein exerts anti-fibrosis activity by reducing the ferroptosis response on the UUO-induced rat model and renal MPC5 cells. Therefore, Baicalein, as a novel therapeutic method on kidney diseases with strong activity in suppressing ferroptosis, could be a potential alternative treatment for renal interstitial fibrosis.

Targeting FTO induces colorectal cancer ferroptotic cell death by decreasing SLC7A11/GPX4 expression.

Ferroptosis is a newly identified iron-dependent form of death that is becoming increasingly recognized as a promising avenue for cancer therapy. N6-methyladenosine (m6A) is the most abundant reversible methylation modification in mRNA contributing to tumorigenesis. However, the crucial role of m6A modification in regulating ferroptosis during colorectal cancer (CRC) tumorigenesis remains elusive. Herein, we find that m6A modification is increased during ferroptotic cell death and correlates with the decreased m6A demethylase fat mass and obesity-associated protein (FTO) expression. Functionally, we demonstrate that suppressing FTO significantly induces CRC ferroptotic cell death, as well as enhancing CRC cell sensitivity to ferroptosis inducer (Erastin and RSL3) treatment. Mechanistically, high FTO expression increased solute carrier family 7 member 11 (SLC7A11) or glutathione peroxidase 4 (GPX4) expressions in an m6A-YTHDF2 dependent manner, thereby counteracting ferroptotic cell death stress. In addition, we identify Mupirocin as a novel inhibitor of FTO, and Mupirocin induces CRC ferroptosis and inhibits tumor growth. Clinically, the levels of FTO, SLC7A11, and GPX4, are highly correlated expression in CRC tissues. Our findings reveal that FTO protects CRC from ferroptotic cell death in promoting CRC tumorigenesis through triggering SLC7A11/GPX4 expression.