Search Results (481)

Extracellular vesicles (EVs) are promising biomarkers for liquid biopsy, but their clinical application is limited by intrinsic heterogeneity and the lack of methods capable of resolving functionally distinct EV subpopulations at the single-vesicle level. Conventional bulk analyses obscure rare but clinically relevant EV subsets, while most single-EV approaches focus on physical properties or surface markers, with limited access to intravesicular functional information. Here, we report a fusion-enabled EV detection strategy at the single-particle level for functional profiling of macrophage-derived EVs. Liposomal probes encapsulating L-arginine, NADPH, and a nitric oxide (NO)-responsive fluorescent dye are engineered to fuse with EV membranes, delivering substrates into the vesicle lumen. In macrophage-derived EVs, inducible nitric oxide synthase (iNOS) catalyzes NO production, activating the fluorescent probe and generating a localized signal within individual vesicles. Signal generation is confined to vesicle-restricted reactions, ensuring specificity and minimizing background. The formation of hybrid vesicles further facilitates optical detection using conventional fluorescence microscopy. Full article

Sea urchins are invertebrates that play a crucial role in marine ecosystems by controlling benthic algal communities and whose natural populations are being affected by different biotic and abiotic factors. Triggering physiological processes promotes the activation of certain metabolic pathways, so oxidative status markers could be a suitable tool to asses maturation stage in which natural populations are. Antioxidant status of three species of Mediterranean Sea urchins, A. lixula, P. lividus and S. granularis, was evaluated in gonadal and digestive tissue. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione s-transferase (GST), glucose 6-phosphate dehydrogenase (G6PDH), NAD(P)H: quinone oxidoreductase (NQO1) and lipid peroxidation were assayed. Significant differences were found among species, displaying in general higher antioxidant activity in A. lixula and S. granularis compared to P. lividus. A significant effect of sex was observed with females exhibiting a higher gonadosomatic index and higher levels of lipid peroxidation mainly in A. lixula. These results seem to be related to metabolic fluctuations associated with the gonadal maturation stage. Changes in digestive tissue were less evident, but some differences among species could be related to triggered digestive processes for replenishment of energy reserves in gonads. Oxidative status can be a useful complementary tool to evaluate gonadal condition in species of sea urchin from the same habitat. Integrative physiological and biochemical studies will contribute to the knowledge of invertebrate physiology. Full article

Background/Objectives: MYC-driven tumors exhibit significant glutamine addiction, but the metabolic adaptation mechanisms enabling their survival under glutamine deprivation remain incompletely understood. Malic enzymes catalyze the oxidative decarboxylation of malate to pyruvate while generating NADPH, linking central carbon metabolism to redox homeostasis. This study investigates whether and how ME1 and ME2 mediate cell adaptation to glutamine starvation and explores their functional division in relation to p53 status. Methods: Using MYC-amplified, p53-mutant (G266E) SF188 glioblastoma cells, we performed siRNA-mediated knockdown, overexpression, and rescue experiments. Cell survival was assessed by trypan blue exclusion and Annexin V/PI staining. ROS levels and NADP⁺/NADPH ratios were measured by DCFH-DA fluorescence and enzymatic assays. Metabolite tracing was conducted using [U-¹³C₅] glutamine followed by LC-MS. Key findings were validated in additional cell lines including HCT116, U2OS and MDA-MB-231. Results: ME1 and ME2 promote SF188 cell survival under glutamine deprivation, an effect that depends on their catalytic activity but is independent of TCA cycle anaplerosis. ME1 maintains redox balance by generating NADPH, and antioxidant treatment rescues the survival defect caused by ME1 knockdown. In contrast, ME2 does not contribute to redox regulation but stabilizes mutant p53 (G266E) via proteasome inhibition. Both of these pro-survival functions are attenuated upon MYC knockdown, suggesting a dependency on MYC expression. Across all cell lines tested, ME1 and ME2 also promote survival through redox maintenance, although the isoform responsible for antioxidant function differs. Conclusions: ME1 and ME2 support metabolic adaptation to glutamine starvation through distinct, isoform-specific mechanisms that depend on MYC expression and p53 mutation status. These findings suggest malic enzymes as potential therapeutic targets in MYC-driven, p53-mutant tumors. Full article

Environmental pollutants, lifestyle factors, and intrinsic metabolism can amplify reactive oxygen and nitrogen species (ROS/RNS) generation beyond antioxidant capacity. The resulting oxidative stress damages macromolecules, perturbs redox signaling, and may accelerate biological aging. This review synthesizes evidence published mainly in 2020–2025 on how major pollutant classes (air pollutants, metals, pesticides, nanoparticles, and micro-/nanoplastics) induce ROS through shared nodes mitochondrial electron transport disruption, NADPH oxidase activation, and redox cycling/Fenton chemistry and how these signals propagate to epigenetic remodeling (DNA methylation, histone modifications, and non-coding RNAs). To move beyond descriptive cataloging, we grade the strength of evidence by study context (cell culture, animal models, human observational studies, and clinically oriented biomarker research), highlight convergent findings and unresolved controversies, and specify key methodological limits. We then compare oxidative-stress biomarker platforms by analytical specificity, pre-analytical susceptibility, and translational readiness, distinguishing validated markers from exploratory redox-epigenetic and multi-omics signatures. Finally, we discuss how exposomics and AI-assisted multi-omics integration may support biomarker discovery while emphasizing current constraints (confounding, batch effects, and limited prospective validation) that must be addressed for clinical translation. Full article

Alcohol-associated Hepatitis (AH) is a rare acute injury caused by alcohol consumption, which can lead to one of the most severe manifestations of liver disease. It is part of the alcohol-related liver diseases (ArLD) spectrum, which represents a major global health burden, with oxidative stress and inflammation serving as central, interconnected pathogenic mechanisms. Chronic alcohol (ethanol) consumption induces hepatic reactive oxygen species (ROS) generation through multiple pathways, including cytochrome P450 2E1 (CYP2E1) induction, mitochondrial dysfunction, and NADPH oxidase activation. These oxidative insults trigger a cascade of cellular damage encompassing lipid peroxidation, protein adduct formation, DNA damage, and endoplasmic reticulum stress, ultimately leading to hepatocyte dysfunction and multiple forms of cell death, including apoptosis, necroptosis, pyroptosis, and ferroptosis. The inflammatory response, orchestrated primarily by Kupffer cells and infiltrating neutrophils through Toll-like receptor (TLR) signalling and inflammasome activation, not only amplifies hepatic injury but also promotes fibrogenesis through hepatic stellate cell activation. Neutrophils, characterised by elevated lipocalin-2 expression and spontaneous NETosis in AH, exhibit a paradoxical role by driving both tissue damage and repair. Current therapeutic strategies include corticosteroids, which remain the first-line treatment for severe AH, while emerging therapies targeting the gut–liver axis, hepatic regeneration, and specific molecular targets show promise in clinical trials. This review comprehensively examines the molecular crosstalk between oxidative stress and inflammation in the pathogenesis of AH to highlight current and investigational therapeutic approaches targeting these interconnected pathways. Full article

Objectives: This study aims to identify the reactive metabolite of acetaminophen (AAP) and the cyanopyrrolidine metabolite of saxagliptin in human induced pluripotent stem cell-derived hepatic organoids (HHOs) and to compare them with human liver microsomes (HLMs) and plateable cryopreserved human hepatocytes (CHHs) to evaluate the feasibility of HHOs for reactive metabolite screening and metabolite profiling. Methods: AAP (50 μM) or sax-agliptin (50 μM) was incubated for 1 h at 37 °C in HLMs with or without NADPH-generating solution and 0.5 mM reduced glutathione (GSH). AAP (50 μM) was incubated for 24 h in HHOs and CHHs at 37 °C in a CO₂ incubator. AAP and saxagliptin metabolites in the reaction mixtures were analyzed using ultra-performance liquid chromatography coupled with tandem mass spectrometry. Results: N-acetyl-p-benzoquinone imine (NAPQI) was identified in the incubation mixture of HLMs with AAP, and its levels were reduced in the presence of GSH, accompanied by increased formation of AAP–GSH adduct. Incubation of AAP with HHOs for 24 h resulted in the formation of NAPQI, AAP–GSH, AAP–glucuronide, and AAP–sulfate. Moreover, CYP1A2 induction using omeprazole treatment increased the formation of AAP and AAP–GSH conjugate from phenacetin, reflecting enhanced CYP1A2 activity in both CHHs and HHOs. The findings indicate that HHOs are a suitable platform for reactive metabolites, such as NAPQI and AAP–GSH adducts, under chronic exposure and metabolic modulator intervention. Additionally, CHHs and HHOs exhibited similar saxagliptin metabolite profiles after incubation with saxagliptin and generated cysteine conjugates of saxagliptin and its hydroxylated metabolite. Conclusions: HHOs system can be used as an in vitro model for screening reactive metabolites, comparable to those obtained with CHHs. Full article

Chemotherapy resistance remains a major obstacle to durable cancer control, yet its underlying mechanisms cannot be fully explained by genetic mutations alone. Increasing evidence suggests that therapeutic stress induces dynamic adaptive programs that reshape tumor phenotypic landscapes. Here, we propose a systems-level framework in which chemotherapy resistance emerges from the stabilization of interconnected stress-response circuits integrating redox signaling, metabolic reprogramming, and transcriptional plasticity. In this model, cytotoxic therapies function as state-generating perturbations that elevate oxidative stress and activate adaptive buffering systems, including NADPH-dependent redox homeostasis, replication stress tolerance, and integrated stress response (ISR)-mediated translational reprogramming. These adaptive modules collectively expand the accessibility of therapy-tolerant phenotypic states within tumor cell populations. Importantly, these circuits coordinate mitochondrial redox homeostasis, metabolic NADPH regeneration, and epigenetic–transcriptional plasticity to sustain cellular survival under persistent oxidative pressure. Such adaptive redox networks not only stabilize stress-tolerant phenotypes but also create vulnerabilities that can be therapeutically exploited. From a translational perspective, this framework suggests that effective strategies to overcome chemotherapy resistance should move beyond single-target inhibition and instead focus on circuit-guided therapeutic interventions that simultaneously destabilize redox buffering systems, constrain phenotypic plasticity, and disrupt metabolic stress adaptation. By conceptualizing therapy resistance as a dynamic redox-regulated state-space phenomenon, this model provides a mechanistic foundation for the development of evolution-aware and plasticity-constraining therapeutic strategies. Targeting the coordinated redox–metabolic–translational circuits that maintain tumor adaptability may therefore represent a promising direction for next-generation redox therapeutics in cancer. Full article

The crystal structure of proteins is generally considered static due to the constraints imposed by crystal packing. We determined the crystal structure of rice NADP-malic enzyme 2 (OsNADP-ME2), an oxidative decarboxylase that converts malic acid to pyruvate and provides NADPH to generate reactive oxygen species. The OsNADP-ME2 is crystallized as a tetramer in the space group of P2₁. In the crystal, all the crystal packing interactions are made through the NADP-binding domain of the enzyme. Interestingly, a protomer shows a conformational change, with a 7.4° tilt in the NADP-binding domain. Basically, the crystal packing consists of a horizontal arrangement of vertically parallel P2₁ screw axes. In the vertical direction, a protomer (Mol A) is tightly sandwiched by two protomers (Mol C) of nearby tetramers and vice versa. In the horizontal direction, two protomers (Mol B and D) of a tetramer are parallelly bound to nearby tetramers, of which one protomer (Mol B) has tighter interactions than the other protomer (Mol D). The protomer Mol D, with the least interaction surface in the crystal packing, adopts an open conformation of the NADP-binding domain, which may be the flexible part of the enzyme for NADP+ cofactor binding. Crystallization can provide valuable information for protein structure. Full article

Abiotic stresses disrupt redox homeostasis and reduce crop productivity. Antioxidant networks support resilience by limiting excess reactive oxygen species (ROS) and maintaining redox signalling for stress perception, gene expression, and metabolic reprogramming. We summarize advances (2000–2025) in ROS generation, detoxification mechanisms, and signalling across organelles, including chloroplasts, mitochondria, peroxisomes, and the apoplast. This includes compartmentalized enzymes—superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione peroxidase (GPX), and glutathione reductase (GR)—as well as the peroxiredoxin–thioredoxin system and non-enzymatic buffers like ascorbate, glutathione, tocopherols, carotenoids, and flavonoids. We uniquely synthesize these findings in a compartment-resolved “redox rheostat” model, linking ROS concentration–time windows (signaling vs. damage) to antioxidant network design (kinetic tiers, compartmentation, and trade-offs) and identifying intervention points for breeding, genome editing, and field-scale priming. We emphasize constraints, such as NADPH supply and antioxidant recycling capacity, that lead to context-dependent outcomes. We evaluate omics, transgenic strategies, genome editing (CRISPR and Cas systems), exogenous applications, and plant–microbe associations. This synthesis clarifies how antioxidant systems protect photosynthetic and respiratory machinery while supporting signalling, thus outlining routes to climate-resilient, yield-stable crops across varied environments and stresses. Full article

Morchella is a nutritious and artificially cultivable rare ascomycete, and its growth and development regulation mechanisms are a current research hotspot. High-temperature stress severely limits the annual yield of Morchella, and this challenge is intensifying with global warming. However, previous studies have lacked systematic screening for heat-tolerant Morchella strains, and their molecular response mechanisms to heat stress remain unclear. In this study, we conducted a comprehensive analysis of phenotypic characteristics, physiological metabolism, and transcriptomics on 19 Morchella strains under normal (25 °C) and high-temperature (30 °C) conditions. The heat-tolerant strain HLM exhibited superior performance in mycelial growth, morphology, and field cultivation. It maintained cell homeostasis under heat stress through mild osmotic regulation (elevated levels of proline, soluble sugars, and proteins), a robust antioxidant system (increased activities of CAT, POD, and SOD), and reduced malondialdehyde accumulation. Transcriptomic analysis identified a novel regulatory model of “stress perception—metabolic preparation—terminal detoxification” in the heat-tolerant strain HLM under heat stress. The rapid upregulation of the SMPD1 gene may mediate ceramide signal generation, promoting G6PDH expression to drive carbon flow into the pentose phosphate pathway, thereby increasing NADPH output. As the detoxification terminal, AKR4C uses this reducing power to eliminate toxic carbonyl end products like malondialdehyde, completing the defense loop. These findings offer new insights into the heat-tolerance mechanisms of large ascomycetes, provide a theoretical foundation for stress-resistant Morchella breeding and cultivation in high-temperature areas, and serve as valuable resources for exploring heat-tolerance mechanisms and molecular breeding in other edible fungi. Full article

Background/Objectives: Females are generally more resistant to ischemia-related ferroptosis than males, due to differences in iron metabolism, antioxidant pathways, and sex hormone-mediated regulation of ferroptosis suppressors. This has not been systematically studied in a human donor liver model. To investigate the effect of sex on ferroptosis and oxidative stress pathways in non-utilized donor livers (NDLs), we assessed patterns of gene expression in NDLs under ex vivo normothermic machine perfusion (NMP). Methods: We utilized the PROTECT dual-circuit ex vivo NMP system to assess three male and two female NDLs undergoing 6 h NMP. Perfusate and tissue samples were collected at baseline and 6 h of NMP. Malondialdehyde (MDA) levels were quantified as biochemical markers of iron overload and lipid peroxidation, respectively. Ferroptosis-related gene expression was assessed using molecular assays. Comparisons between male and female NDLs were used to determine the influence of sex on ferroptosis and oxidative injury during NMP. Results: NMP was successfully performed on NDLs (n = 5) from three male (56.3 ± 5.7 years) and two female donors (46.5 ± 0.7 years, p = 0.15). The fold-change in the oxidative stress marker MDA was comparable between female (1.2 ± 0.6) and male (1.0 ± 0.4) NDLs after 6 h NMP (p = 0.76). All livers showed upregulation of ferroptosis-related genes (Hypoxia-inducible factor 1 alpha, Iron Responsive Binding Elements 2, Ribosomal Protein L8, Ferritin Heavy Chain 1, Acyl-CoA synthetase family member 2, ATP synthase membrane subunit c locus 3, Heme-oxygenase 1, NAD(P)H Quinone Dehydrogenase 1, Tetratricopeptide Repeat Domain 35, Nuclear Factor Erythroid 2 Related Factor 2). ACSF2 expression was significantly higher in female NDLs compared with males undergoing 6 h NMP (3.6 ± 3.0 vs. 1.0 ± 0.7-fold change, p = 0.04). There were no sex-based significant differences observed in the expression of other ferroptosis-related genes (HIF-1α, IREB2, RPL8, FTH-1, ATP5G3, HO-1, NQO1, TTC35, and NRF2) between male and female NDLs. No gene reached statistical significance after false-discovery-rate (FDR) correction. Conclusions: Normothermic machine perfusion of NDLs was feasible, and no sex-related differences were observed in MDA levels or most ferroptosis-related gene expression after 6 h. Although ACSF2 showed higher expression in female livers, this was not significant after multiple testing correction, highlighting the need for larger studies to explore sex-dependent ferroptosis signaling during liver preservation. Full article

Diabetic ketoacidosis (DKA) remains a life-threatening complication of diabetes mellitus with suboptimal outcomes despite standard management. Emerging evidence suggests that thiamine (vitamin B1) deficiency may play an under-recognized role in DKA pathophysiology and clinical course. This narrative review synthesizes current evidence regarding thiamine deficiency in diabetes and DKA, examining molecular mechanisms, clinical implications, and the rationale for thiamine supplementation as adjunctive therapy. Thiamine deficiency is highly prevalent in diabetes, with plasma concentrations reduced by approximately 75% compared to healthy controls. In DKA specifically, 25–35% of patients present with thiamine deficiency, which often worsens during insulin therapy. The primary mechanism involves hyperglycemia-induced downregulation of renal thiamine transporters (THTR-1 and THTR-2), resulting in 16–24-fold increased renal clearance and massive urinary losses. Thiamine pyrophosphate serves as an essential cofactor for three critical enzymes in glucose metabolism: pyruvate dehydrogenase, α-ketoglutarate dehydrogenase, and transketolase. Deficiency impairs these pathways, causing pyruvate accumulation with conversion to lactate (resulting in lactic acidosis), compromised TCA cycle function (reducing ATP production by 40–48%), and decreased NADPH generation (increasing oxidative stress). Clinical manifestations include persistent metabolic acidosis despite standard therapy, myocardial dysfunction with elevated cardiac biomarkers, neurological impairment, and prolonged recovery times. Cellular studies demonstrate that thiamine supplementation significantly improves mitochondrial oxygen consumption in DKA patients. The high prevalence of thiamine deficiency in DKA, compelling biochemical rationale, excellent safety profile, and preliminary mechanistic evidence support the urgent need for large-scale randomized controlled trials examining thiamine supplementation to definitively establish efficacy, optimal dosing, and patient selection criteria. Full article

Cardiovascular diseases (CVDs) remain the leading cause of mortality worldwide. CVDs are associated with multiple factors, including oxidative stress, mediated endothelial dysfunction, vascular inflammation, and atherothrombosis. Although traditional antioxidant supplementation (such as vitamins C, E, and β-carotene) has shown promising results in rigorous animal model studies, it has consistently failed to demonstrate clinical benefit in most human trials. Consequently, there is a substantial unmet need for novel paradigms involving mechanistically and biologically relevant pharmaceutical-grade antioxidant therapies (“next-generation antioxidants”). Rapid advancements in redox biology, nanotechnology, genetic modulation of redox processes, and metabolic regulation have enabled the development of new antioxidant therapeutics, including mitochondrial-targeted agents, NADPH oxidase (NOX) inhibitors, selenoprotein and Nrf2 activators, engineered nanoparticles, catalytic antioxidants, and RNA-based and gene-editing strategies. These interventions have the potential to modulate specific oxidative pathways that contribute to CVD pathogenesis. This review provides a comprehensive assessment of current oxidative stress–modulating modalities and their potential to inform personalized cardiovascular prevention and treatment strategies. Full article

Oxidative stress (OS) resulting from an imbalance between reactive oxygen species (ROS) generation and antioxidant defenses plays a pivotal role in vascular diseases such as atherosclerosis and hypertension. ROS derived from NADPH oxidase, mitochondria, and xanthine oxidase promote endothelial dysfunction by inducing lipid and protein oxidation, apoptosis, and pro-inflammatory signaling, thereby enhancing smooth muscle proliferation and atherogenesis. This review summarizes the molecular mechanisms linking OS to vascular injury and aims to systematically elucidate the role of OS in vascular diseases, with a specific focus on critiquing the current challenges in translating biomarkers to clinical practice and the emerging trends in personalized antioxidant therapy. Particular attention is given to biomarkers of oxidative stress, including those assessing antioxidant enzyme activity and oxidative damage products, which possess potential for clinical use. Therapeutic strategies targeting OS, including dietary and pharmacological antioxidants, show promise in improving vascular health, although clinical outcomes have been inconsistent and it is necessary to resolve the standardization and validation of these biomarkers, develop precise targeted therapies against specific ROS sources (e.g., NOX inhibitors, mitochondrial antioxidants), and explore personalized clinical trials based on redox stratification. Overall, OS is a central mediator in vascular pathology, and progress in biomarker validation and targeted therapies will be essential to translate current knowledge into effective prevention, diagnosis, and treatment of cardiovascular diseases. Personalized approaches based on accurate redox profiling may enhance efficacy. Full article

Background: The golden apple snail (Pomacea canaliculata), an invasive species originating from South America, has inflicted considerable agricultural and ecological harm in non-native habitats. While the molluscicide niclosamide is currently effective against P. canaliculata, its prolonged use raises environmental concerns and the risk of resistance development. Results: BAM 15 possesses strong molluscicidal activity against P. canaliculata, with 72 h LC₅₀ values of 0.4564 mg/L for adults (shell height: 20–25 mm), 0.3352 mg/L for subadults (10–15 mm), and 0.1142 mg/L for juveniles (2–3 mm). Metabolomic and proteomic profiling revealed that the altered metabolites and proteins both converged on energy metabolism and oxidative stress. Experimental validation revealed that BAM15 collapsed the mitochondrial membrane potential, drove MDA and H₂O₂ upward while depleting NADPH, boosted CAT, SOD and GPX activities, yet suppressed GR, and ultimately inflicted overt damage in the head-foot tissue of P. canaliculata. Conclusions: Our findings reveal that BAM 15 operates via a three-stage mechanism: (1) it disrupts membrane potential (ΔΨm) and impairs ATP production, severely disturbing energy metabolism; (2) energy deficits stimulate excessive electron transport chain activity, generating reactive oxygen species (ROS) and initiating oxidative stress; (3) persistent metabolic imbalance and oxidative damage culminate in extensive tissue injury. These results identify BAM 15 as a promising candidate for molluscicide development. Full article