Objective Ferroptosis has been shown to participate in luteolysis, yet the upstream signals and metabolic remodeling that trigger it remain unknown. This study aims to clarify these mechanisms.Methods Physiological postpartum and PGF2α-induced luteolysis models were established in mice. Targeted energy metabolomics, pharmacological inhibition and adenoviral shRNA-mediated knockdown were employed in vivo and in primary luteal cells to measure ferroptosis markers, G6PD activity, NADP⁺/NADPH ratio and NOX2/NOX4 expression.Results In both models, luteal regression was accompanied by increased ACSL4, decreased GPx4 and GSH, and elevated Fe2⁺ and lipid peroxidation and NOX2 and NOX4 expression. Metabolic analysis revealed 6-phosphogluconate accumulation, reduced pyruvate and pyruvate kinase M activity, and increased G6PD expression and activity, but NADPH depletion and redox imbalance. In vivo, combined NOX2/NOX4 knockdown reduced ROS accumulation, suppressed G6PD hyperactivation, alleviated ferroptotic injuryand delayed regression Moreover, G6PD inhibition with 6-AN similarly reduced oxidative stress and ferroptosis and partially restored progesterone secretion. In primary luteal cells, G6PD knockdown or 6-AN treatment attenuated PGF2α-induced ferroptosis and improved cell viability. Simultaneously, NOX2/NOX4 silencing, N-acetylcysteine, or Ferrostatin-1 suppressed PGF2α-induced G6PD activation, and attenuated oxidative stress and ferroptosis.Conclusion NOX2/NOX4-associated oxidative stress contributes to G6PD-associated metabolic remodeling and ferroptosis during mice luteolysis.
Objectives: Reactive oxygen and nitrogen species (RONS) act as signalling molecules under physiological conditions; however, how oxidative eustress regulates glucose uptake in skeletal muscle remains poorly defined. We investigated the role of moderate oxidation in skeletal muscle glucose uptake, focusing on AKT/AMPK phosphorylation, GLUT4 translocation and functional glucose uptake. Methods: AKT and AMPK phosphorylation were analysed in C2C12 myoblasts/myotubes exposed to insulin and redox-modulating stimuli associated with oxidative eustress, including hydrogen peroxide, nitric oxide donors and angiotensin II. GLUT4 translocation was assessed by quantitative immunocytochemistry and confocal fluorescence microscopy in cells expressing a GLUT4 reporter. Glucose uptake was evaluated in isolated skeletal muscle fibres using 6-NBDG. Results: Oxidative eustress was associated with increased AKT and AMPK phosphorylation and enhanced GLUT4 translocation to the plasma membrane. Hydrogen peroxide, nitric oxide donors and angiotensin II increased GLUT4 presence at the plasma membrane and enhanced glucose uptake, with hydrogen peroxide showing a dose-dependent effect. Increased glucose uptake was consistent with GLUT4 translocation. Discussion: These findings support oxidative eustress as a physiological redox mechanism linking AKT/AMPK activation, GLUT4 translocation and glucose uptake in skeletal muscle. Redox signalling may therefore contribute to skeletal muscle glucose metabolism.
Objectives Cr(VI) and DON are natural co-occurring pollutants in the environment. This study aimed to investigate the molecular mechanisms underlying oxidative damage to the intestinal barrier and intestinal epithelial cell (IECs) toxicity induced by Cr(VI) and DON.Methods The target genes and signaling pathways were predicted using the network toxicology method. This was verified through cell intervention experiments with Nrf2 activator TBHQ, NF-κB inhibitor PDTC, and NLRP3 inhibitor MCC950.Results Cr(VI) and/or DON aggravated inflammatory infiltration in the intestine, disrupted tight junction structures. Network toxicology revealed that ferroptosis and pyroptosis pathways are involved in regulating oxidative damage and barrier dysfunction in primary small IECs in broilers. Cr(VI) and/or DON induced oxidative stress and inhibited Nrf2 expression. They abnormally activated the NF-κB/NLRP3 pathway in IECs, thereby triggering ferroptosis and pyroptosis, and exacerbating oxidative damage to the intestinal barrier. Overexpression of Nrf2 and silencing of NLRP3/NF-κB could bidirectionally reverse oxidative stress, iron accumulation, inflammatory factor secretion and intestinal barrier dysfunction in IECs, inhibit the progression of ferroptosis and pyroptosis.Conclusion The cross-regulation of ferroptosis and pyroptosis mediated by the bidirectional imbalance of the Nrf2/NF‑κB/NLRP3 axis constitutes the core molecular mechanism underlying intestinal epithelial barrier dysfunction and oxidative damage induced by co-exposure to Cr(VI) and DON.
OBJECTIVES:Spinal cord injury (SCI) causes myelin breakdown and membrane disruption, leading to the release and redistribution of cholesterol, fatty acids, and other lipids within the lesion. The resulting disruption of lipid homeostasis can promote sustained lipid peroxidation, neuroinflammation, and repair failure. In recent years, lipid droplets (LDs) have been recognized as highly dynamic organelles that coordinate lipid storage, mobilization, energy metabolism, and stress responses. However, the stage- and cell-specific roles of LDs in lipid-redox dysregulation after SCI remain poorly understood. METHODS:This review summarizes the basic mechanisms of LD formation, lipolysis, and lipophagy, examines the regulation of lipid peroxidation by LDs, and discusses bidirectional LD-mitochondria crosstalk. We further integrate evidence on LD remodeling across microglia/macrophages, astrocytes, neurons, oligodendrocyte-lineage cells, and microvascular endothelial cells. We also consider how these cell-specific changes relate to lipid detoxification and transfer, neuronal oxidative injury, blood-spinal cord barrier dysfunction, and remyelination. RESULTS:We propose that LDs are not passive markers of lipid deposition after SCI but stage- and cell-type-dependent redox-metabolic regulators. Early LD formation may buffer acute lipid overload, whereas persistent oxidative stress, mitochondrial dysfunction, and impaired LD turnover may convert LDs into pathological lipid reservoirs that amplify lipid peroxidation and neuroinflammation. Finally, we discuss therapeutic strategies aimed at limiting pathological lipid accumulation, restoring LD turnover and cholesterol efflux, suppressing lipid peroxidation, and preserving mitochondrial redox homeostasis. DISCUSSION:Together, this review provides an integrated framework for understanding how LD remodeling links lipid metabolic imbalance to secondary injury and neural repair after SCI.
Objectives Neuroblastoma (NB) is a common pediatric extracranial solid tumor. Dimethylaminomicheliolide (DMAMCL), a prodrug of Micheliolide (MCL), shows antitumor activity against NB, but its mechanisms remain unclear. This study investigated the antitumor mechanisms of DMAMCL in NB.Methods Key pathways/genes were identified by RNA-seq and ferroptosis PCR array. Ferroptosis was confirmed by indicators. Mechanisms were investigated using siRNAs, shRNAs, and overexpression plasmids in vitro and in vivo. Direct targets were screened by LiP-MS. Molecular biology experiments elucidated the mechanisms.Results DMAMCL induced ferroptosis in NB in vitro and in vivo, upregulating HMOX1. HMOX1 knockdown attenuated DMAMCL-induced ferroptosis and its overexpression triggered ferroptosis in MYCN-amplified NB cells but not in MYCN-nonamplified cells. DMAMCL-induced ferroptosis via HMOX1 upregulation depended on MYCN levels. Mechanistically, DMAMCL bound to KEAP1 in MYCN-amplified NB cells, increasing nuclear NRF2 and upregulating HMOX1. In MYCN-nonamplified NB cells, DMAMCL upregulated STEAP3, increasing Fe2+ and lipid peroxidation to induce ferroptosis. STEAP3 overexpression induced ferroptosis and suppressed tumor growth.Disscusion DMAMCL induces ferroptosis in NB through MYCN-associated dual pathways, activating the NRF2/HMOX1 axis via KEAP1 binding in MYCN-amplified cells, while upregulating STEAP3 in MYCN-nonamplified cells. This provides new insights for DMAMCL application in treating NB subtypes with different MYCN levels.
Background Ferroptosis induction is a promising triple-negative breast cancer (TNBC) therapy, but current inducers are suboptimal. Nitazoxanide (NTZ), an FDA-approved antiparasitic with anticancer and redox activity, may be repurposed as a ferroptosis inducer, yet its effects and mechanisms in TNBC are unclear.Methods Anti-TNBC effects of NTZ were assessed in MDA-MB-231 and Hs578T cells via viability, clonogenicity, migration/invasion, and zebrafish xenografts. Ferroptosis was evaluated by iron levels, lipid peroxidation, GSH/GSSG, MDA, ROS, and mitochondrial TEM. Mechanisms were studied by docking, western blot, qPCR, apoptosis assay, cycloheximide chase, and pharmacological rescue.Results NTZ inhibited proliferation, migration, and invasion in vitro and tumor growth in vivo, and induced ferroptosis. Mechanistically, it disrupted iron homeostasis by upregulating TFR1 and downregulating FPN1, causing iron overload and lipid peroxidation, and promoted β-catenin degradation, which transcriptionally suppressed GPX4, weakening antioxidant defense. Both β-catenin stabilization and ferroptosis inhibition reversed these effects.Conclusion NTZ is repurposed as a ferroptosis inducer for TNBC via dual disruption of iron homeostasis and β-catenin/GPX4 axis, providing a strong preclinical rationale for its therapeutic use.
ObjectiveOxidative protein modifications have been linked to several diseases, but the variety and diversity of modifications are less studied.MethodsWe used the chicken egg protein ovalbumin and gas plasma technology, a potent source of various reactive species, for protein oxidation. Using high-resolution mass spectrometry and an in-house workflow, over 80 distinct oxidative protein modifications were mapped at per-amino-acid resolution. To examine how modification profiles depend on changes in reactive species types and concentrations, we generated 12 distinct argon gas plasmas by systematically varying molecular gas admixtures (water, ethanol, oxygen, and nitrogen).ResultsOptical emission spectroscopy (OES) and photometric determination of deposited long-lived species (hydrogen peroxide, nitrite, and nitrate) were applied to profile gas plasma conditions, revealing the admixture-dependent impact on the reactive oxygen/nitrogen species (ROS/RNS) fingerprint. Correlation analysis with mass spectrometry data revealed the significant involvement of atomic oxygen and hydrogen peroxide in protein oxidation. The enrichment of specific reactive species created by a defined gas plasma composition generated specific ovalbumin oxidation profiles resolved per amino acid. Feed gas-dependent oxidation hotspots, such as Trp149 for dry argon gas or Met274 for hydroxyl radical-rich humidified argon gas, were identified.DiscussionThis first-of-its-kind study reveals intricate relationships between dynamic reactive species environments and protein oxidation profiles using ovalbumin as a model system.
Due to the proliferative nature of cancer cells, they utilize more dietary extracellular nutrients via one-carbon metabolism for the various metabolic processes, including the synthesis of antioxidants such as glutathione (GSH) and hydrogen sulfide (H2S). Indeed, several studies have found that specific cancer types produce significantly higher levels of GSH and H2S than normal healthy cells, which may serve as a protective mechanism, allowing them to resist stress, survive, and grow. This metabolic heterogeneity, driven by intrinsic and extrinsic factors, contributes to the distinct metabolic characteristics and vulnerabilities of tumor subtypes, which can be exploited to develop anticancer strategies. In this review, we summarize the fundamental roles and regulation of GSH and H2S in normal physiological systems and in the genesis and progression of cancer, their effects on the tumor microenvironment (TME), and their contribution to drug resistance. We also discuss the influences of diet and the gut microbiome on GSH and H2S production, and how cancer cells reprogram their metabolism to grow and survive in a stressful environment by overproducing GSH and H2S.
Objectives Collagen is a long-lived protein present in the extracellular matrix of force-bearing tissues. It has a unique amino acid composition of predominantly glycine, proline and hydroxyproline that repeats throughout its characteristic triple helical structure. In the extracellular space, collagen interact first by a non-enzymatic, entropy-driven process given their high hydrophobicity. Then, enzymes, such as lysyl oxidase (LOX), create covalent bonds (i.e. crosslinks) between triple helices, generating reactive oxygen species (ROS) as a byproduct. Moreover, it was recently discovered that collagen itself generates ROS upon stretching. Therefore, given the close proximity of ROS-generating sources, it seems plausible that collagen undergoes non-enzymatic oxidation.Methods This review discusses collagen structure, mechanisms of crosslink formation and collagen oxidation.Results Despite abundant data on the mechanisms of LOX-mediated collagen oxidation, there is sparse data on the effects of non-enzymatic oxidation on collagen chemical and biophysical properties, as well as its effects on cells and tissues.Discussion The premise that collagen oxidation could lead to persistent damage is discussed in light of the immunogenicity and proteolysis induced by such modifications. Overall, data support that oxidative modifications in collagen should be further explored and could pose as a novel underlying mechanism in ageing and chronic diseases.
Objectives This study investigated the protective effects and mechanisms of rhaponticin (Rha) against acinar cell injury in acute pancreatitis (AP).Methods Pancreatic acinar cell injury was induced using multiple in vitro and in vivo AP models. The mitochondrial function, necrosis, and oxidative stress were assessed. Network pharmacology and molecular docking were applied to predict potential molecular targets, which were subsequently validated experimentally. The involvement of hypoxia-inducible factor 1-alpha (HIF-1α) signaling and necroptosis-related proteins, including receptor-interacting protein kinase 3 (RIP3) and phosphorylated mixed lineage kinase domain-like protein (p-MLKL), was further explored. Both pharmacological inhibition and siRNA-mediated knockdown were employed to verify the target specificity of Rha.Results Rha treatment significantly preserved mitochondrial function, reduced ROS, and alleviated pancreatic injury. Network pharmacology and molecular dockingresults identified HIF -1a as the key target of Rha. Consistently, Rha treatment markedly downregulated HIF-1α expression and inhibited necroptosis by suppressing the activation of RIP3 and p-MLKL. Notably, neither pharmacological inhibition nor siRNA-mediated knockdown of HIF-1α produced additional protective effects in the presence of Rha, indicating the involvement of HIF-1α in mediating its actions.Conclusion Rha effectively attenuates acinar cell necrosis and oxidative via the HIF-1α-mediated necroptosis pathway, highlighting Rha as a promising therapeutic candidate for AP.
Objectives Iron overload (IO) cardiomyopathy is a major cause of mortality in patients with iron overload disorders. This study investigates the role of cystathionine γ-lyase (CSE), a key enzyme in the transsulfuration pathway for cysteine and hydrogen sulfide (H2S) production, in iron-induced oxidative cardiac injury.Methods We investigated the effects of CSE on oxidative stress, metabolic dysregulation, and cardiac remodeling using in vivo mouse models of chronic iron overload and in vitro ferric citrate (FAC)-treated cardiomyocytes.Results Genetic deletion of Cth (encoding CSE) in mice exacerbated iron overload-induced cardiac hypertrophy, systolic dysfunction, and interstitial fibrosis. These effects correlated with reduced expression of the cysteine transporter SLC7A11, impaired glutathione (GSH) synthesis, and suppression of the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1)/glutathione peroxidase 4 (GPX4) antioxidant signaling pathway. Conversely, CSE overexpression in cardiomyocytes restored SLC7A11 stability, and suppressed reactive oxygen species (ROS) production through the Nrf2/HO-1/GPX4 pathway, thereby attenuating iron-mediated oxidative damage. Mechanistically, CSE deficiency disrupted both cysteine uptake via SLC7A11and cysteine production via transsulfuration pathway, inducing a self-reinforcing cycle of oxidative stress.Conclusion These findings demonstrate that the CSE-transsulfuration pathway serves as a crucial regulator of cysteine metabolism and antioxidant signaling in cardiomyocytes, presenting a potential therapeutic target in iron-induced cardiomyopathy.
BACKGROUND:Neuroinflammation, oxidative stress, and ferroptosis are implicated in Parkinson' s disease (PD) pathogenesis. Epidemiological studies suggest that elevated uric acid (UA) levels may reduce PD risk, but the precise molecular mechanisms involved remain unclear. In this study, we investigated the effects of UA in lipopolysaccharide (LPS) or MPP+-stimulated BV2 microglia and MPTP-induced PD mouse models. METHODS:BV2 cells are recognized as a standardized and reproducible neural inflammatory cell model for mechanism exploration. The anti-ferroptosis and anti-inflammatory effects of UA were assessed in LPS or MPP+ stimulated BV2 microglia and in an MPTP-induced PD mouse model. Western blot, qPCR, ELISA, and immunofluorescence were used to analyse the expression of inflammasome-related markers. ROS, MDA, GSH, and Fe²⁺ levels were measured using testing kits, while mitochondrial ultrastructure was evaluated through transmission electron microscopy. PD-related markers were assessed by ethology and immunohistochemistry. The Nrf2 inhibitor ML385 was employed to validate pathway specificity. RESULTS:We found that UA treatment reduced the expression of proinflammatory cytokines (TNF-α, IL-6, and IL-1β), ROS production, lipid peroxidation, and intracellular Fe²⁺ in BV2 microglia while increasing the antioxidant capacity and preserving the mitochondrial ultrastructure. In MPTP-treated mice, UA improved motor performance, preserved dopaminergic neuron density in the substantia nigra, and reduced neuroinflammation. UA activated Nrf2 signalling and upregulated GPX4 expression, which were attenuated by ML385, confirming the Nrf2 dependence of these effects. CONCLUSION:UA alleviates ferroptosis and neuroinflammation in LPS or MPP+ stimulated BV2 microglia and MPTP-induced PD mouse models through the activation of the Nrf2 signalling pathway.
Human serum albumin (HSA) is the most abundant circulating protein and a central mediator of extracellular redox homeostasis. Its antioxidant function has been attributed primarily to the free thiol at cysteine residue 34 (Cys34), whose progressive oxidation-yielding nonmercaptoalbumin isoforms HNA1 and HNA2-serves as a sensitive biomarker of systemic oxidative stress. Advances in electrospray ionisation time-of-flight mass spectrometry have enabled precise quantification of Cys34 modifications, establishing cysteinylated albumin as a clinically applicable marker in chronic kidney disease, chronic liver disease, diabetes, and ageing-related functional decline. Beyond its role as a biomarker, oxidized albumin is now recognized as an active pathogenic mediator in preclinical models, with emerging evidence implicating ferroptosis as a potential mechanism of renal tubular cell injury, and contributing to cardiovascular risk and sarcopenia. A previously unrecognized dimension of albumin redox biology has also emerged: the presence of endogenous oxidized polysulfide bonds (Ox-PSS; RSSn-R', n > 1) across multiple intramolecular cysteine bridges. Quantified using the newly developed Elimination Method for Sulfide from Polysulfide, albumin polysulfides are dynamically regulated by oxidative stress and are significantly depleted in chronic kidney disease and early hepatitis, even when conventional Cys34-based markers remain unchanged. Polysulfide depletion impairs both Site II drug-binding capacity and reactive oxygen species scavenging activity, with direct implications for pharmacokinetics and therapeutic efficacy. These findings collectively reframe HSA as a dynamic polysulfide reservoir and extracellular redox regulator, highlighting albumin polysulfide modulation as a compelling emerging therapeutic strategy.
Alzheimer's disease (AD) is a major global neurodegenerative disorder associated with high morbidity and mortality, yet current treatments remain largely symptomatic and ineffective in halting neurodegeneration. Growing evidence links oxidative stress potentially being an early event in AD progression. Consequently, therapeutic strategies targeting oxidative stress-mediated cellular damage are increasingly attractive. This review summarizes clinical evidence of oxidative stress biomarkers in AD and examines the neuroprotective mechanisms of flavonoids against oxidative stress in vivo, together with current clinical findings. Despite inconsistencies among studies due to variations in detection methods, a consistent trend of elevated oxidative stress in AD is evident, correlating with disease severity. Although in vivo studies have demonstrated that flavonoids restore antioxidant defences and suppress neuroinflammation, convincing clinical evidence of their efficacy in AD patients remains limited. Overall, these findings emphasize oxidative stress as a therapeutic target requiring further validation efforts.
BACKGROUND:Pseudomonas aeruginosa relies on antioxidant enzymes to withstand host-derived oxidative stress during infection. Here, we investigated the role of bacterial glutathione peroxidase (GPx) in survival and virulence of the PA14 strain under inflammatory conditions associated with hyperuricemia. METHODS:Wild-type (WT) and Δgpx strains were exposed to isolated hypochlorous acid (HOCl), hydrogen peroxide (H₂O₂), tert-butyl hydroperoxide, and urate hydroperoxide (HOOU) or challenged with human neutrophils in the presence or absence of oxidative burst modulators. In vivo, normouricemic and potassium oxonate-induced hyperuricemic mice were intranasally infected with WT or Δgpx strains to assess bacterial burden, inflammation, oxidative damage, and survival. RESULTS:Deletion of gpx increased bacterial susceptibility to all oxidants, particularly HOOU, and significantly reduced survival in activated neutrophils. In mice, Δgpx infection resulted in reduced pulmonary bacterial burden, attenuated neutrophil infiltration, lower oxidative damage, and markedly improved survival compared to WT infection, an effect exacerbated by hyperuricemia in WT-infected animals. These findings demonstrate that GPx detoxifies organic hydroperoxides generated during inflammation, enhancing P. aeruginosa resistance to oxidative killing and promoting virulence. CONCLUSION:Collectively, our results highlight the importance of redox regulation in bacterial pathogenesis and identify GPx as a potential target for redox-based anti-virulence strategies against multidrug-resistant P. aeruginosa.
Background Oxidative stress-induced liver injury can progress to severe hepatic conditions. Polysaccharides are promising therapeutic agents, but the protective effects of Angelica dahurica polysaccharide (ADP) against this injury remain unclear.Purpose This study was conducted to elucidate ADP's protective effects and underlying molecular mechanisms in Ovariectomize/D-galactose (OVX/D-Gal) rats.Methods Fifty female OVX rats and ten sham-operated (SO) rats were randomly divided into six groups. Except SO group, rats were administered the corresponding doses of ADP and resveratrol respectively, and the model was established by 49-day daily subcutaneous D-Gal injection. Serum and liver samples were collected to examine the hepatic histopathological changes, oxidative stress-related biomarkers, inflammatory factors, and protein and gene expression levels.Results ADP reduced serum ALT and AST levels (P < 0.01) and improved liver histology. ADP increased SOD and GSH-Px activities , decreased MDA levels (P < 0.05). ADP also lowered pro-inflammatory cytokines levels, upregulated Nrf2, HO-1, and NQO-1 expression, promoted Bcl-2 and suppressed Bax and cleaved caspase-3 (P < 0.05).Conclusions ADP alleviated OVX/D-Gal-induced oxidative stress and liver injury by increasing antioxidant capacity, inhibiting apoptosis, attenuating inflammation, and activating Nrf2/HO-1/NQO-1 signaling pathway.
Background Cancer stem cells (CSCs) support colorectal cancer progression and therapy resistance, yet the redox regulators that sustain CSC identity are incompletely defined. We investigated the role of peroxiredoxin 5 (PRX5) in CSC formation and tumorigenicity using HCT116 colorectal cancer models.Methods CSCs were enriched by serum-free spheroid culture and characterized by qPCR and western blotting for pluripotency and surface markers. PRX5 expression was regulated via siRNA or shRNA gene disruption and overexpression. Intracellular ROS was measured with DCF-DA staining. STAT3 activation was analyzed by p-STAT3 immunoblot. Functional assays included sphere formation, extreme limiting dilution analysis (ELDA), colony formation, and in vivo xenograft tumorigenicity in BALB/c-nu mice.Results Spheroid induction selectively upregulated PRX5 among PRX isoforms. Efficient PRX5 knockdown (>95%) reduced OCT4, SOX2, NANOG, and CD133 expression, increased intracellular ROS, lowered p-STAT3 levels, and decreased sphere-forming frequency. Conversely, PRX5 overexpression enhanced pluripotency marker expression and proliferation. In vivo, PRX5-overexpressing xenografts grew faster, achieving a 2.5-fold greater tumor volume by day 19 and a 1.82-fold higher mean tumor weight compared with controls. Tumor tissues showed elevated OCT4, SOX2, NANOG, CD133, and EPCAM.Conclusion PRX5 contributes to maintaining a redox environment associated with STAT3 activation and core stemness programs in CRC, promoting CSC phenotypes and tumorigenicity. Targeting PRX5-mediated redox signaling may warrant further investigation as a potential approach to disrupt CSC maintenance and overcome chemoresistance.
Background Postmenopausal osteoporosis (PMOP) is characterized by exacerbated bone resorption and inadequate bone formation, with macrophage-driven inflammation playing a key role. However, how immunometabolic reprogramming of macrophages modulates osteoblast fate remains unknown.Methods Using integrated single-cell and bulk transcriptomics, we identified a hypermetabolic macrophage subpopulation in PMOP marrow reliant on HIF-1α-glycolysis. We pharmacologically disrupted this axis with the HDAC inhibitor valproic acid (VPA) and validated its function using the HIF-1α stabilizer DMOG. The paracrine effects on osteoblasts were assessed via conditioned medium, focusing on ferroptosis and differentiation. Therapeutic efficacy was tested in ovariectomized rats.Results VPA upregulated HIF1AN, enhancing its binding to HIF-1α and promoting its degradation. This suppressed glycolytic flux and M1 polarization, reducing IL-6 secretion. The altered secretome protected osteoblasts from ferroptosis by inhibiting the IL-6/p-STAT3/HIF-1α/TFRC axis and rebalancing GPX4/ACSL4. Osteogenic differentiation was restored. In OVX rats, VPA improved bone mass and microstructure, effects abolished by DMOG.Conclusion We unveil a macrophage-centric immunometabolic checkpoint that is linked to osteoblast ferroptosis via IL-6/STAT3 signaling. Targeting this HIF-1α-glycolysis axis, exemplified by VPA, represents a novel therapeutic strategy for PMOP.
Objectives Sepsis is a life-threatening condition driven by a dysregulated immune response to infection, yet therapeutic options beyond antibiotics and vasopressors remain limited. Neutrophil extracellular traps (NETs) contribute significantly to sepsis-induced tissue injury, and NETosis inhibition has emerged as a potential therapeutic strategy. We hypothesized that the endogenous metabolite bilirubin mitigates inflammation in sepsis by inhibiting NETosis through targeting NOX2.Methods Two murine sepsis models were used to assess the effects of bilirubin on survival and systemic NETosis. Plasma NET biomarkers were quantified, and primary human neutrophils were used to validate the NETosis-inhibitory activity of bilirubin in vitro. Mechanistic studies included ROS measurements, NOX2 loop C mutational analysis, and inhibition of endocytosis and autophagy to examine how bilirubin modulates NOX2 stability.Results Bilirubin improved survival and reduced NET biomarkers in both models. It inhibited NETosis in human neutrophils by suppressing ROS-dependent NETosis and promoting the internalization and degradation of NOX2 via endocytosis and autophagy.Discussion These findings identify bilirubin as an endogenous inhibitor of NETosis. By targeting NOX2 and suppressing NETosis, bilirubin may represent a promising therapeutic candidate for sepsis management.
Objective Subarachnoid hemorrhage (SAH) is associated with high mortality and poor outcomes, which are closely related to white matter injury (WMI). (-)-Epigallocatechin-3-gallate (EGCG) exerts neuroprotective effects by inhibiting oxidative stress-related ferroptosis in astrocytes and improving neurological function. However, the role and mechanism of EGCG in regulating reactive astrocytes (RAs) to alleviate WMI after SAH remain unclear.Methods A mouse model of SAH was used to evaluate the effects of EGCG-loaded nanoparticles (EGCG-NPs). Western blot, qPCR, and immunofluorescence were performed for biochemical analysis. Neurological function was assessed using neurological deficit scores and the Morris water maze test.Results Following SAH, HO-1-mediated iron accumulation and ROS production promoted A1/A2 reactive astrocyte polarization, resulting in myelination damage and aggravated WMI. Knockdown of S100A10 inhibited iron-dependent oxidative stress in RAs and attenuated WMI. EGCG-NPs significantly suppressed HO-1/S100A10-mediated iron overload and oxidative stress in both A1 and A2 RAs, thereby alleviating WMI after SAH.Conclusion EGCG-NPs attenuate SAH-induced WMI by inhibiting the iron overload-activated HO-1/S100A10 axis in RAs, representing a promising therapeutic strategy.
