acyl-CoA Synthetase Long-chain Family Member Research Articles

WWP2 protects against sepsis-induced cardiac injury through inhibiting cardiomyocyte ferroptosis.

Cardiac injury plays a critical role in contributing to the mortality associated with sepsis, a condition marked by various forms of programmed cell deaths. Previous studies hinted at the WW domain-containing E3 ubiquitin protein ligase 2 (WWP2) involving in heart failure and endothelial injury. However, the precise implications of WWP2 in sepsis-induced cardiac injury, along with the underlying mechanisms, remain enigmatic. Sepsis induced cardiac injury were constructed by intraperitoneal injection of lipopolysaccharide. To discover the function of WWP2 during this process, we designed and performed loss/gain-of-function studies with cardiac-specific vectors and WWP2 knockout mice. Combination experiments were performed to investigate the relationship between WWP2 and downstream signaling in septic myocardium injury. The protein level of WWP2 was downregulated in cardiomyocytes during sepsis. Cardiac-specific overexpression of WWP2 protected heart from sepsis induced mitochondrial oxidative stress, programmed cell death and cardiac injury, while knockdown or knockout of WWP2 exacerbated this process. The protective potency of WWP2 was predominantly linked to its ability to suppress cardiomyocyte ferroptosis rather than apoptosis. Mechanistically, our study revealed a direct interaction between WWP2 and acyl-CoA synthetase long-chain family member 4 (FACL4), through which WWP2 facilitated the ubiquitin-dependent degradation of FACL4. Notably, we observed a notable reduction in ferroptosis and cardiac injury within WWP2 knockout mice after FACL4 knockdown during sepsis. WWP2 assumes a critical role in safeguarding the heart against injury induced by sepsis via regulating FACL4 to inhibit LPS-induced cardiomyocytes ferroptosis.

Selenium binding protein 1 protects renal tubular epithelial cells from ferroptosis by upregulating glutathione peroxidase 4

Ferroptosis is a form of programmed cell death involved in various types of acute kidney injury (AKI). It is characterized by inactivation of the selenoprotein, glutathione peroxidase 4 (GPX4), and upregulation of acyl-CoA synthetase long-chain family member 4 (ACSL4). Since urinary selenium binding protein 1 (SBP1/SELENBP1) is a potential biomarker for AKI, this study investigated whether SBP1 plays a role in AKI. First, we showed that SBP1 is expressed in proximal tubular cells in normal human kidney, but is significant downregulated in cases of AKI in association with reduced GPX4 expression and increased ACSL4 expression. In mouse renal ischemia-reperfusion injury (I/R), the rapid downregulation of SBP1 protein levels preceded downregulation of GPX4 and the onset of necrosis. In vitro, hypoxia/reoxygenation (H/R) stimulation in human proximal tubular epithelial (HK-2) cells induced ferroptotic cell death in associated with an acute reduction in SBP1 and GPX4 expression, and increased oxidative stress. Knockdown of SBP1 reduced GPX4 expression and increased the susceptibility of HK-2 cells to H/R-induced cell death, whereas overexpression of SBP1 reduced oxidative stress, maintained GPX4 expression, reduced mitochondrial damage, and reduced H/R-induced cell death. Finally, selenium deficiency reduced GPX4 expression and promoted H/R-induced cell death, whereas addition of selenium was protective against H/R-induced oxidative stress. In conclusion, SBP1 plays a functional role in hypoxia-induced tubular cell death. Enhancing SBP1 expression is a potential therapeutic approach for the treatment of AKI.

Electroacupuncture suppresses neuronal ferroptosis to relieve chronic neuropathic pain.

Growing evidence supports the analgesic efficacy of electroacupuncture (EA) in managing chronic neuropathic pain (NP) in both patients and NP models induced by peripheral nerve injury. However, the underlying mechanisms remain incompletely understood. Ferroptosis, a novel form of programmed cell death, has been found to be activated during NP development, while EA has shown potential in promoting neurological recovery following acute cerebral injury by targeting ferroptosis. In this study, to investigate the detailed mechanism underlying EA intervention on NP, male Sprague-Dawley rats with chronic constriction injury (CCI)-induced NP model received EA treatment at acupoints ST36 and GV20 for 14 days. Results demonstrated that EA effectively attenuated CCI-induced pain hypersensitivity and mitigated neuron damage and loss in the spinal cord of NP rats. Moreover, EA reversed the oxidative stress-mediated spinal ferroptosis phenotype by upregulating reduced expression of xCT, glutathione peroxidase 4 (GPX4), ferritin heavy chain (FTH1) and superoxide dismutase (SOD) levels, and downregulating increased expression of acyl-CoA synthetase long-chain family member 4 (ACSL4), malondialdehyde levels and iron overload. Furthermore, EA increased the immunofluorescence co-staining of GPX4 in neurons cells of the spinal cord of CCI rats. Mechanistic analysis unveiled that the inhibition of antioxidant pathway of Nrf2 signalling via its specific inhibitor, ML385, significantly countered EA's protective effect against neuronal ferroptosis in NP rats while marginally diminishing its analgesic effect. These findings suggest that EA treatment at acupoints ST36 and GV20 may protect against NP by inhibiting neuronal ferroptosis in the spinal cord, partially through the activation of Nrf2 signalling.

Neuroinvasive virus facilitates viral replication by employing lipid droplets to reduce arachidonic acid-induced ferroptosis

Lipids have been previously implicated in the lifecycle of neuroinvasive viruses. However, the role of lipids in programmed cell death and the relationship between programmed cell death and lipid droplets (LDs) in neuroinvasive virus infection remains unclear. Here, we found that the infection of neuroinvasive virus, such as rabies virus and encephalomyocarditis virus could enhance the LD formation in N2a cells, and decreasing LDs production by targeting diacylglycerol acyltransferase could suppress viral replication. The lipidomics analysis revealed that arachidonic acid (AA) was significantly increased after reducing LD formation by restricting diacylglycerol acyltransferase, and AA was further demonstrated to induce ferroptosis to inhibit neuroinvasive virus replication. Moreover, lipid peroxidation and viral replication inhibition could be significantly alleviated by a ferroptosis inhibitor, ferrostatin-1, indicating that AA affected neuroinvasive virus replication mainly through inducing ferroptosis. Furthermore, AA was demonstrated to activate the acyl-CoA synthetase long-chain family member 4-lysophosphatidylcholine acyltransferase 3-cytochrome P450 oxidoreductase axis to induce ferroptosis. Our findings highlight novel cross-talks among viral infection, LDs, and ferroptosis for the first time, providing a potential target for antiviral drug development.

METTL3 promotes trophoblast ferroptosis in preeclampsia by stabilizing the ACSL4 m6A modification

This study aims to explore the role of methyltransferase-like 3 (METTL3) modulation of ferroptosis in the pathogenesis of trophoblast-mediated preeclampsia. The expression of METTL3 and acyl-CoA synthetase long chain family member 4 (ACSL4) was measured in clinical placental tissues and trophoblasts using qPCR and Western blot techniques. The effects of METTL3 on the symptoms of preeclampsia were also validated in rat models. METTL3 and ACSL4 were upregulated in placental tissues from patients with preeclampsia and in hypoxia-induced trophoblasts. METTL3 silencing increased the migration and invasion of trophoblasts cultured under hypoxic conditions. Knockdown of METTL3 increased cell viability and suppressed ferroptosis in hypoxia-stimulated trophoblasts. Hypoxia increased the level of m6A in cells, whereas silencing METTL3 partially reversed this change. Silencing METTL3 resulted in a decrease in m6A modification of ACSL4 mRNA, which led to a reduction in ACSL4 mRNA stability. ACSL4 upregulation partially reversed the effects of METTL3 silencing on cell viability, migration, invasion, and ferroptosis in hypoxia-stimulated trophoblasts. Inhibition of METTL3 in preeclampsia rats decreased blood pressure, urine protein levels, fetal survival rate, and ACSL4-mediated ferroptosis. METTL3 elevates ferroptosis to inhibit the migration and invasion of trophoblasts and in vivo preeclampsia symptoms by catalyzing the m6A modification of ACSL4 mRNA.

Chaihu Sanshen Capsules protect rats from myocardial ischemia reperfusion injury via PKCβⅡ/NOX2/ROS signaling pathway

This study aims to explore the pathogenesis of myocardial ischaemia reperfusion injury(MIRI) based on oxidative stress-mediated programmed cell death and the mechanism and targets of Chaihu Sanshen Capsules in treating MIRI via the protein kinase Cβ(PKCβⅡ)/NADPH oxidase 2(NOX2)/reactive oxygen species(ROS) signaling pathway. The rat model of MIRI was established by the ligation of the left anterior descending branch. Rats were randomized into 6 groups: sham group, model group, clinically equivalent-, high-dose Chaihu Sanshen Capsules groups, N-acetylcysteine group, and CGP53353 group. After drug administration for 7 consecutive days, the area of myocardial infarction in each group was measured. The pathological morphology of the myocardial tissue was observed by hematoxylin-eosin(HE) staining. The apoptosis in the myocardial tissue was observed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling(TUNEL). Enzyme-linked immunosorbent assay(ELISA) was employed to measure the le-vels of indicators of myocardial injury and oxidative stress. The level of ROS was detected by flow cytometry. The protein and mRNA levels of the related proteins in the myocardial tissue were determined by Western blot and real-time quantitative PCR(RT-qPCR), respectively. Compared with the sham group, the model group showed obvious myocardial infarction, myocardial structural disorders, interstitial edema and hemorrhage, presence of a large number of vacuoles, elevated levels of myocardial injury markers, myocardial apoptosis, ROS, and malondialdehyde(MDA), lowered superoxide dismutase(SOD) level, and up-regulated protein and mRNA le-vels of PKCβⅡ, NOX2, cysteinyl aspartate specific proteinase-3(caspase-3), and acyl-CoA synthetase long-chain family member 4(ACSL4) in the myocardial tissue. Compared with the model group, Chaihu Sanshen Capsules reduced the area of myocardial infarction, alleviated the pathological changes in the myocardial tissue, lowered the levels of myocardial injury and oxidative stress indicators and apoptosis, and down-regulated the mRNA and protein levels of PKCβⅡ, NOX2, caspase-3, and ACSL4 in the myocardial tissue. Chaihu Sanshen Capsules can inhibit oxidative stress and programmed cell death(apoptosis, ferroptosis) by regulating the PKCβⅡ/NOX2/ROS signaling pathway, thus mitigating myocardial ischemia reperfusion injury.

Iron-induced kidney cell damage: insights into molecular mechanisms and potential diagnostic significance of urinary FTL.

Background: Iron overload can lead to organ and cell injuries. Although the mechanisms of iron-induced cell damage have been extensively studied using various cells, little is known about these processes in kidney cells. Methods: In this study, we first examined the correlation between serum iron levels and kidney function. Subsequently, we investigated the molecular impact of excess iron on kidney cell lines, HEK293T and HK-2. The presence of the upregulated protein was further validated in urine. Results: The results revealed that excess iron caused significant cell death accompanied by morphological changes. Transcriptomic analysis revealed an up-regulation of the ferroptosis pathway during iron treatment. This was confirmed by up-regulation of ferroptosis markers, ferritin light chain (FTL), and prostaglandin-endoperoxide synthase 2 (PTGS2), and down-regulation of acyl-CoA synthetase long-chain family member 4 (ACSL4) and glutathione peroxidase 4 (GPX4) using real-time PCR and Western blotting. In addition, excess iron treatment enhanced protein and lipid oxidation. Supportively, an inverse correlation between urinary FTL protein level and kidney function was observed. Conclusion: These findings suggest that excess iron disrupts cellular homeostasis and affects key proteins involved in kidney cell death. Our study demonstrated that high iron levels caused kidney cell damage. Additionally, urinary FTL might be a useful biomarker to detect kidney damage caused by iron toxicity. Our study also provided insights into the molecular mechanisms of iron-induced kidney injury, discussing several potential targets for future interventions.

Silencing KPNA2 Promotes Ferroptosis in Laryngeal Cancer by Activating the FoxO Signaling Pathway.

We aim to clarify the specific role of Karyopherin α2 (KPNA2) in the progression of laryngeal cancer, a kind of malignant tumor with a poor curative effect.We performed the bioinformatic analysis to obtain the ferroptosis-related differentially expressed genes. KPNA2 was screened out. Then the CCK-8 assay, wound healing assay, and transwell assay were used to clarify the changes in the proliferation, migration, and invasion abilities of laryngeal cancer cells after silencing KPNA2. The concentrations of iron ions, glutathione, superoxide dismutase, and malondialdehyde were evaluated by the corresponding detection kits. The expression levels of cyclooxygenase 2, Acyl-CoA synthetase long-chain family member 4, glutathione peroxidase 4, forkhead box O (FoxO)1a and FoxO3a were determined by Western Blot.A total of 45 ferroptosis-related differentially expressed genes in laryngeal cancer were obtained, and KPNA2 was selected after bioinformatic analysis. In ferroptosis-induced laryngeal cancer cells, the cell viability, migration rate, invasion ability, and the expression of glutathione peroxidase 4, glutathione, and superoxide dismutase were further decreased and the expression of cyclooxygenase 2, Acyl-CoA synthetase long-chain family member 4, iron ions, and malondialdehyde were further increased after silencing KPNA2. The expression levels of FoxO1a and FoxO3a in laryngeal cancer cells were increased by silencing KPNA2.KPNA2 may be a promising therapeutic target for laryngeal cancer. Down-regulation of KPNA2 can promote ferroptosis in laryngeal cancer by stimulating the FoxO signaling pathway.

Protective effects and mechanism of chemical- and plant-based selenocystine against cadmium-induced liver damage

Although selenium (Se) and cadmium (Cd) often coexist naturally in the soil of China, the health risks to local residents consuming Se-Cd co-enriched foods are unknown. In the present study, we investigated the effects of chemical-based selenocystine (SeCys2) on cadmium chloride-induced human hepatocarcinoma (HepG2) cell injury and plant (Cardamine hupingshanensis)-derived SeCys2 against Cd-induced liver injury in mice. We found that chemical- and plant-based SeCys2 showed protective effects against Cd-induced HepG2 cell injury and liver damage in mice, respectively. Compared with Cd intervention group, co-treatment with chemical- or plant-based SeCys2 both alleviated liver toxicity and ferroptosis by decreasing ferrous iron, acyl-CoA synthetase long-chain (ACSL) family member 4, lysophosphatidylcholine acyltransferase 3, reactive oxygen species and lipid peroxide levels, and increasing ACSL3, peroxisome proliferator-activated receptor α, solute carrier family 7 member 11 (SLC7A11) and glutathione and glutathione peroxidase 4 (GPX4) levels. In conclusion, chemical- and plant-based SeCys2 alleviated Cd-induced hepatotoxicity and ferroptosis by regulating SLC7A11/GPX4 signaling and lipid peroxidation. Our findings indicate that potential Cd toxicity from consuming foods grown in Se- and Cd-rich soils should be re-evaluated. This study offers a new perspective for the development of SeCys2-enriched agricultural products.

Role of Ferroptosis in the Progression of COVID-19 and the Development of Long COVID.

To examine the role of ferroptosis on the pathogenesis and progression of COVID-19. A total of 127 patients who were hospitalized for COVID-19 were categorized into two groups according to the intensity of oxygen therapy (high-flow or low-flow). Clinical characteristics, laboratory parameters, plasma markers, and peripheral blood mononuclear cell (PBMC) markers were measured at baseline and one or two weeks after treatment. Telephone follow-up was performed 3 months after discharge to assess long COVID. Patients receiving high-flow oxygen therapy had greater levels of neutrophils; D-dimer; C reactive protein; procalcitonin; plasma protein levels of tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), IL-17, and acyl-CoA synthetase long-chain family member 4 (ACSL4); and PBMC mRNA level of TNF-α; but had lower levels of lymphocytes and plasma glutathione peroxidase 4 (GPX4). There were negative correlations of plasma GPX4 and cystine/glutamate transporter-11 (SLC7A11) with TNF-α, IL-6, and IL-17, and positive correlations of ACSL4 with inflammatory markers in plasma and PBMCs. The plasma levels of TNF-α, IL-6, IL-17, and ACSL4 were significantly lower after treatment than at baseline, but there were higher post-treatment levels of lymphocytes, GPX4, and SLC7A11. Patients with long COVID had a lower baseline level of plasma SLC7A11. Ferroptosis is activated during the progression of COVID-19, and a low baseline level of a ferroptosis marker (SLC7A11) may indicate an increased risk for long COVID-19. Ferroptosis has potential as a clinical indicator of long COVID and as a therapeutic target.

ACSL1-Mediated Fatty Acid β-Oxidation Enhances Metastasis and Proliferation in Endometrial Cancer.

Gynecological malignancies, such as endometrial cancer (EC) and uterine cancer are prevalent. Increased Acyl-CoA synthetase long-chain family member 1 (ACSL1) activity may contribute to aberrant lipid metabolism, which is a potential factor that contributes to the pathogenesis of endometrial cancer. This study aimed to elucidate the potential molecular mechanisms by which ACSL1 is involved in lipid metabolism in endometrial cancer, providing valuable insights for targeted therapeutic strategies. Xenograft mouse models were used to assess the effect of ACSL1 on the regulation of endometrial cancer progression. ACSL1 protein levels were assessed via immunohistochemistry and immunoblotting analysis. To assess the migratory potential of Ishikawa cells, wound-healing and Transwell invasion assays were performed. Changes in lipids in serum samples from mice with endometrial cancer xenotransplants were examined in an untargeted lipidomic study that combined multivariate statistical methods with liquid chromatography‒mass spectrometry (LC/MS). Patient sample and tissue microarray data suggested that higher ACSL1 expression is strongly associated with the malignant progression of EC. Overexpression of ACSL1 enhances fatty acid β-oxidation and 5'-adenylate triphosphate (ATP) generation in EC cells, promoting cell proliferation and migration. Lipidomic analysis revealed that significant changes were induced by ACSL1, including changes to 28 subclasses of lipids and a total of 24,332 distinct lipids that were detected in both positive and negative ion modes. Moreover, pathway analysis revealed the predominant association of these lipid modifications with the AMPK/CPT1C/ATP pathway and fatty acid β-oxidation. This study indicates that ACSL1 regulates the AMPK/CPT1C/ATP pathway, which induces fatty acid β-oxidation, promotes proliferation and migration, and then leads to the malignant progression of EC.

Baicalin alleviates oxygen–glucose deprivation/reoxygenation‐induced SK‐N‐SH cell injury via the regulation of miR‐556‐3p/ACSL4 pathway

AbstractBaicalin (BCL) has been found to have neuroprotective effects in ischemic stroke (IS), but its underlying molecular mechanisms are unknown. SK‐N‐SH cells were treated with BCL and then induced by oxygen–glucose deprivation/reoxygenation (OGD/R). Cell proliferation, apoptosis, inflammation, and ferroptosis were detected. Protein levels were examined by western blot. The expression levels of microRNA (miR)‐556‐3p and ACSL4 were tested via quantitative real‐time PCR. MiR‐556‐3p and Acyl‐CoA synthetase long‐chain family member 4 (ACSL4) interaction was confirmed via dual‐luciferase reporter assay and RNA pull‐down assay. Middle cerebral artery occlusion (MCAO) mice model was constructed to assess the role of BCL on brain injury in vivo. Our study showed that BCL treatment alleviated OGD/R‐induced SK‐N‐SH cell apoptosis, inflammation and ferroptosis. MiR‐556‐3p was decreased in OGD/R‐induced SK‐N‐SH cells, and BCL treatment enhanced its expression. MiR‐556‐3p could target ACSL4, and its overexpression relieved OGD/R‐induced SK‐N‐SH cell injury by targeting ACSL4. Besides, miR‐556‐3p inhibitor or ACSL4 overexpression reversed the inhibitory effect of BCL on OGD/R‐induced SK‐N‐SH cell injury. In vivo, BCL alleviated brain injury in MCAO mice through miR‐556‐3p/ACSL4 axis. In conclusion, BCL alleviated OGD/R‐induced SK‐N‐SH cell injury and relieved brain injury in MCAO mice by regulating miR‐556‐3p/ACSL4 axis.

METTL14 depletion ameliorates ferroptosis in severe acute pancreatitis by increasing the N6-methyladenosine modification of ACSL4 and STA1

Methyltransferase-like 14 (METTL14) is implicated in the regulation of various inflammatory disorders. However, its function and molecular mechanism in severe acute pancreatitis (SAP) remains unrevealed. Here we reported an increase in METTL14 in the pancreas of SAP mice and cerulein-LPS-treated AR42J cells. METTL14 depletion reversed inflammatory response and ferroptosis by reducing the expression of SAT1 (spermidine/spermine N1-acetyltransferase 1) and ACSL4 (acyl-CoA synthetase long chain family member 4) in an m6A-dependent manner. IGF2BP2 (insulin like growth factor 2 mRNA binding protein 2) could recognize m6A-modified SAT1 and ACSL4 mRNA and enhance their stability. Moreover, METTL14 depletion ameliorated pancreatic injury, inflammation, and ferroptosis induced by SAP. METTL14 overexpression aggravated SAP by promoting ferroptosis in vivo. Therefore, these results demonstrated that METTL14-induced ferroptosis promoted the progression of SAP, and targeting METTL14 or ferroptosis could be a potential strategy for the prevention and treatment of SAP.

The Preventative Effect of Chitooligosaccharides against Chronic Alcoholic Liver Disease by Regulating Alcohol Metabolism, Fatty Acid Metabolism, and Intestinal Barrier Damage

Since chronic alcoholic liver disease (ALD) is a significant global health concern, several studies have shown that chitooligosaccharides (COS) exhibit hepatoprotective effects. This paper examined the COS protective effect on chronic ALD mice. Results showed that COS improved the lipid accumulation, liver injury, and oxidative stress levels in the mice while inhibiting cytochrome P450 protein 2E1 (CYP2E1) expression in the liver and promoting alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH1) expression, indicating that COS could ameliorate alcohol metabolism. Moreover, COS intervention also enhanced the antioxidant capacity of the liver and upregulated peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1), silent information regulator 1 (SIRT1), HO-1, and nuclear factor-erythroid 2-related factor 2 (NRF2) protein levels. In addition, COS increased peroxisome proliferator-activated receptor α (PPARα), acyl-CoA oxidase (ACOX), acyl-CoA synthetase long-chain family member (ACSL), carnitine palmitoyltransferase 1A (CPT-1A), and carnitine palmitoyltransferase 2 (CPT2) protein levels by upregulating the fatty acid β oxidation pathway and restoring mitochondrial genesis. From a liver-gut axis perspective, COS enhanced intestinal barrier function by increasing the adhesion junction (AJ) and intestinal tight junction (TJ) protein expression. Therefore, COS displayed a protective ability against chronic ALD. The results provide a theoretical basis for utilizing supplemental dietary COS as a functional food alternative for treating chronic ALD.

Serum ACSL4 levels in patients with ST-segment elevation myocardial infarction (STEMI) and its association with one-year major adverse cardiovascular events (MACE): A prospective cohort study.

In the present prospective cohort research, we aimed to explore the serum levels of Acyl-CoA synthetase long-chain family member 4 (ACSL4) in patients with ST-segment elevation myocardial infarction (STEMI) and its association with 1-year major adverse cardiovascular events (MACE). This prospective cohort study recruited 507 patients who underwent percutaneous coronary intervention for the treatment of STEMI at our hospital during August 2019 to July 2022. The serum ACSL4, tumor necrosis factor-α, interleukin (IL)-6, IL-1β, and C-reactive protein levels were measured by enzyme-linked immunosorbent assay. Demographic and clinical statistics were also collected. In addition, all patients were followed up for 1 year, and patients with MACE were defined as poor prognosis group. All data used SPSS 26.0 to statistical analyses. The poor prognosis group had significantly higher age and low-density leptin cholesterol (LDLC) levels compared to the favorable prognosis group (P < .05). STEMI patients exhibited significantly elevated serum levels of ACSL4, tumor necrosis factor-α, IL-6, IL-1β, and C-reactive protein (P < .05). Serum ACSL4 and IL-1β levels in the poor prognosis group were remarkably enhanced compared to the favorable prognosis group. Curvilinear regression analysis demonstrated that ACSL4 was associated with LDLC and IL-1β. Moreover, ACSL4 (B = 0.138, 95% CI 1.108-1.189, P < .001), LDLC (B = 2.317, 95% CI 5.253-19.603, P < .001), and IL-1β (B = 0.061, 95%CI 1.008-1.122, P = .025) levels were the risk factors for STEMI patients with 1-year MACE. This study showed that the serum ACSL4 levels was remarkably elevated in STEMI patients. This study might provide new targets and a comprehensive approach to cardiovascular protection in STEMI patients.

Propionate promotes ferroptosis and apoptosis through mitophagy and ACSL4-mediated ferroptosis elicits anti-leukemia immunity

Short-chain fatty acids (SCFAs), particularly propionate and butyrate, have been reported in many cancers. However, the relationship between propionate and acute myeloid leukemia (AML) remains unclear. Additionally, Acyl-CoA synthetase long chain family member 4 (ACSL4) has been reported to regulate immunity in solid tumors, but there are still many gaps to be filled in AML. Here, we discovered the underlying mechanism of propionate and ACSL4-mediated ferroptosis for immunotherapy. Our results showed that the level of propionate in the AML patients’ feces was decreased, which was correlated to gut microbiota dysbiosis. Moreover, we demonstrated that propionate suppressed AML progression both in vivo and in vitro. In mechanism, propionate induced AML cells apoptosis and ferroptosis. The imbalance of reactive oxygen species (ROS) and redox homeostasis induced by propionate caused mitochondrial fission and mitophagy, which enhanced ferroptosis and apoptosis. Furthermore, ACSL4-mediated ferroptosis caused by propionate increased the immunogenicity of AML cells, induced the release of damage-associated molecular patterns (DAMPs), and promoted the maturation of dendritic cells (DCs). The increased level of immunogenicity due to ferroptosis enable propionate-based whole-cell vaccines to activate immunity, thus further facilitating effective killing of AML cells. Collectively, our study uncovers a crucial role for propionate suppresses AML progression by inducing ferroptosis and the potential mechanisms of ACSL4-mediated ferroptosis in the regulation of AML immunity.

A Mechanism Study on the Antioxidant Pathway of Keap1-Nrf2-ARE Inhibiting Ferroptosis in Dopaminergic Neurons.

The pathology of Parkinson's disease (PD) indicates that iron deposition exists in dopaminergic neurons, which may be related to the death of cellular lipid iron peroxide. The extracellular autophagy adaptor SQSTM1(p62) of dopamine (DA) neurons can activate the intracellular Keap1-Nrf2-ARE signaling pathway to inhibit ferroptosis, which has a protective effect on DA neurons. The objective of this study was to investigate the protective mechanism of the Keap1- Nrf2-ARE antioxidant pathway against iron death in dopaminergic neurons. The experiment was divided into a control group (Control group), 1-methyl-4- phenylpyridiniumion control group (MPP+ Control group), p62 overexpression group (MPP+OVp62), and p62 overexpression no-load group (MPP+ OV-P62-NC). The inhibitors brusatol and ZnPP inhibited the activation of NF-E2-related factor 2(Nrf2) and Heme oxygenase-1(HO-1), respectively, and were divided into brusatol group (MPP+OV-p62+brusatol) and ZnPP group (MPP+OV-p62+ZnPP). RT-qPCR was used to detect transfection efficiency, and Cell Counting Kit-8 (CCK8) was used to detect cell activity. FerroOrange, 2,7-Dichlorodihydrofluorescein diacetate (DCFH-DA), and Liperfluo probes were used to detect intracellular iron, reactive oxygen species (ROS), and lipid peroxidation (LPO) levels. Western Blotting detected the levels of Nrf2, HO-1, Kelch-like ECH-associated protein1 (Keap1), and their downstream Glutathione peroxidase 4(GPX4) and Acyl-CoA synthetase long-chain family member 4(ACSL4). The levels of LGlutathione (GSH) and Malondialdehyde (MDA) were detected by GSH and MDA kits, and the activation of Keap1-Nrf2-ARE pathway was verified at the cellular level to have an antioxidant protective effect on iron death in dopaminergic neurons. (1) The results of RT-qPCR showed that compared with the control group, the expression of the p62 gene was significantly increased in the MPP+OV-p62 groups (P = 0.039), and the p62 gene was significantly increased in the brusatol and ZnPP groups, indicating successful transfection (P =0.002; P=0.008). (2) The immunofluorescence probe flow results showed that compared to the normal control group, the contents of three kinds of probes in MPP+ model group were significantly increased (P =0.001; P ＜0.001; P＜0.001), and the contents of three kinds of probes in MPP+OV-p62 group were decreased compared to the MPP+ model group (P =0.004). The results indicated that the levels of iron, ROS, and LPO were increased in the MPP+ group and decreased in the MPP+OV-p62 group. (3) Compared with the control group, the expressions of Nrf2, HO-1, and GPX4 in the MPP+OV-p62 group were increased (P =0.007; P =0.004; P=0.010), and the expressions of Keap1 and ACSL4 in MPP+p62 overexpression group were decreased (P =0.017; P =0.005). Compared with the MPP+ control group, Nrf2 and GPX4 were increased in the MPP+OV-p62 group, and ACSL4 was decreased in the MPP+OVp62 group (P =0.041; P ＜0.001; P ＜0.001). The results of the GSH and MDA kit showed that compared with the normal control group, the content of GSH in the MPP+ control group was decreased (P < 0.01), and the content of MDA was increased (P < 0.01). Compared with the MPP+ model group, GSH content was increased (P = 0.003), and MDA content was decreased in the MPP+OV-p62 group (P < 0.001). Nrf2, HO-1, and GPX4 increased in the MPP+p62 overexpression group but decreased in the brusatol group and ZnPP group (P < 0.001). Based on the transfection of P62 plasmid, it was found that P62 plasmid can inhibit the lipid peroxidation of iron death in dopaminergic nerve cells by activating the Nrf2 signaling pathway, thus playing a protective role in dopaminergic nerve cells.

Effect and mechanism of Jiedu Huoxue Decoction in regulating YAP/ACSL4 pathway to inhibit ferroptosis in treatment of acute kidney injury

Jiedu Huoxue Decoction(JDHX), first recorded in the Correction on Errors in Medical Works by WANG Qing-ren, is an effective formula screened out from ancient formulas by the traditional Chinese medicine(TCM) master ZHANG Qi to treat acute kidney injury(AKI) caused by heat, toxicity, stasis, and stagnation. This paper elucidated the therapeutic effect of JDHX on AKI and probed into the potential mechanism from ferroptosis. Thirty-two male C57BL/6 mice were randomized into four groups(n=8): normal, model, and low-and high-dose JDHX. Since the clinical treatment of AKI depends on supportive or alternative therapies and there is no specific drug, this study did not include a positive drug group. The low dose of JDHX corresponded to half of clinically equivalent dose, while the high dose corresponded to the clinically equivalent dose. Mice were administrated with JDHX by gavage daily for 7 consecutive days, while those in the normal group and the model group were administered with the corresponding volume of distilled water. On day 5 of drug administration, mice in other groups except the normal group were injected intraperitoneally with cisplatin solution at a dose of 20 mg·kg~(-1) to induce AKI, and the normal group was injected with saline. All of the mice were sacrificed 72 h after modeling, blood and kidney samples were collected for subsequent analysis. The levels of serum creatine(Scr) and blood urea nitrogen(BUN) were measured by the commercial kits. The expression level of kidney injury molecule 1(KIM-1) in the serum was measured by enzyme-linked immunosorbent assay. Hematoxylin-eosin(HE) staining, periodic acid-Schiff(PAS) staining, and Prussian blue staining were employed to observe the pathological changes, glycogen deposition, and iron deposition, respectively, in the renal tissue. In addition, the levels of glutathione(GSH), superoxide dismutase(SOD), and catalase(CAT) in the renal tissue were examined by biochemical colorimetry. Western blot was performed to determine the protein levels of acyl-CoA synthetase long chain family member 4(ACSL4), lysophosphatidylcholine acyltransferase 3(LPCAT3), and Yes-associated protein(YAP, a key molecule in the Hippo pathway) in the renal tissue. Immunohistochemistry was then employed to detect the location and expression of YAP in the renal tissue. Real-time fluorescence quantitative polymerase chain reaction(qRT-PCR) was performed to measure the mRNA levels of ACSL4 and glutathione peroxidase 4(GPX4). Compared with the normal group, the model group showed elevated serum levels of Scr, BUN, and KIM-1. In the AKI model group, the tubular epithelial cells underwent atrophy and necrotic detachment, disappearance of brush border, and some tubules became protein tubules or experienced vacuole-like degeneration. In addition, this group presented widening of the interstitium or even edema, increased renal tubule injury score, and obvious glycogen and iron deposition in parts of the renal tissue. Moreover, the model group had lower GSH, SOD, and CAT levels, higher ASCL4 and LPCAT3 levels, and lower GPX4 expression and higher YAP expression than the normal group. Compared with the model group, high dose of JDHX effectively protected renal function, lowered the levels of Scr, BUN and KIM-1, alleviated renal pathological injury, reduced glycogen and iron deposition, and elevated the GSH, SOD, and CAT levels in the renal tissue. Furthermore, JDHX down-regulated the protein levels of ACSL4, LPCAT3, and YAP and up-regulated the level of GPX4, compared with the model group. In conclusion, JDHX can protect mice from cisplatin-induced AKI by inhibiting ferroptosis via regulating the YAP/ACSL4 signaling pathway.

FNDC5/Irisin mitigates high glucose-induced neurotoxicity in HT22 cell via ferroptosis.

Diabetes-induced neuropathy represents a major etiology of dementia, highlighting an urgent need for the development of effective therapeutic interventions. In this study, we explored the role of fibronectin type III domain containing 5 (FNDC5)/Irisin in mitigating hyperglycemia-induced neurotoxicity in HT22 cells and investigated the underlying mechanisms. Our findings reveal that high glucose conditions are neurotoxic, leading to reduced viability of HT22 cells and increased apoptosis. Furthermore, the elevated expression of the intracellular ferroptosis marker Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4), along with increased levels of ferrous ions and malondialdehyde (MDA), suggests that high glucose conditions may induce ferroptosis in HT22 cells. FNDC5/Irisin treatment effectively mitigates high glucose-induced neurotoxicity and ferroptosis in HT22 cells. Mechanistically, FNDC5/Irisin enhances cellular antioxidant capacity, regulates ACSL4 expression, and improves intracellular redox status, thereby inhibiting ferroptosis and increasing HT22 cell survival under high-glucose conditions. These results highlight the neuroprotective potential of FNDC5/Irisin in high glucose environments, offering a promising avenue for developing treatments for diabetes-related neurodegenerative diseases.

Study on the Role and Mechanism of SLC3A2 in Tumor-Associated Macrophage Polarization and Bladder Cancer Cells Growth.

Background: Solute carrier family 3 member 2 (SLC3A2) is highly expressed in various types of cancers, including bladder cancer (BLCA). However, the role and mechanism of SLC3A2 in the onset and progression of BLCA are still unclear. Methods: The interfering plasmid for SLC3A2 was constructed and transfected into BLCA cells. Cell proliferation, invasion, and migration abilities were assessed to evaluate the impact of SLC3A2 silencing on BLCA cell growth. M1 and M2 macrophage polarization markers were detected to evaluate macrophage polarization. The levels of reactive oxygen species (ROS), lipid peroxidation, and Fe2+, as well as the expression of ferroptosis-related proteins, were measured to assess the occurrence of ferroptosis. Ferroptosis inhibitors were used to verify the mechanism. Results: The experimental results showed that SLC3A2 was highly expressed in BLCA cell lines. The proliferation, invasion, and migration of BLCA cells were reduced after interfering with SLC3A2. Interference with SLC3A2 led to increase the expression of M1 macrophage markers and decreased the expression of M2 macrophage markers in M0 macrophages co-cultured with tumor cells. Additionally, interference with SLC3A2 led to increased levels of ROS, lipid peroxidation, and Fe2+, downregulated the expression of solute carrier family 7 member11 (SLC7A11) and glutathione peroxidase 4 (GPX4), while upregulated the expression of acyl-coA synthetase long chain family member 4 (ACSL4) and transferrin receptor 1 (TFR1) in BLCA cells. However, the impact of SLC3A2 interference on cell proliferation and macrophage polarization was impeded by ferroptosis inhibitors. Conclusion: Interference with SLC3A2 inhibited the growth of BLCA cells and the polarization of tumor-associated macrophages by promoting ferroptosis in BLCA cells.