Search Results (2,013)

The fungal pathogen Candida albicans coordinated metabolism, organelle homeostasis, and stress responses for adapting to diverse host environments and maintaining virulence. While transcriptional control of these processes has been extensively studied, the contribution of post-transcriptional regulation remains incompletely understood. Here, we identify the P-body component Lsm1 as a critical factor of metabolic adaptation, mitochondrial homeostasis, and pathogenicity in C. albicans. Transcriptomic analysis revealed that loss of Lsm1 causes global transcriptional imbalance, leading to dysfunction of amino acid metabolism, mitochondrial function, endocytic trafficking, and autophagy processes. This dysfunction is accompanied by diminished TORC1 activity. Due to the aberrant TORC1 regulation caused by loss of Lsm1, ATG mRNA stability and autophagy flux was impaired under nutrient-rich condition and nitrogen starvation condition. In this context, the lsm1Δ/Δ cells established an adaptive metabolic and redox state characterized by altered NAD⁺/NADH and NADP⁺/NADPH balance, and enhanced antioxidant capacity. Moreover, the lsm1Δ/Δ cells displayed the defects in hyphal development, biofilm formation, and host cell interaction, and exhibited the attenuated virulence in a murine infection model. Together, our findings revealed that Lsm1-mediated post-transcriptional regulation is associated with the maintenance of amino acid metabolism, mitochondrial function, and TORC1 activity to fungal virulence, revealing a potential therapeutic target for C. albicans infections. 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

High-efficiency Ovum Pick-Up (OPU) and in vitro embryo production (IVP) are critical for the genetic improvement of high-value Wagyu cattle. However, oxidative stress and mitochondrial dysfunction during oocyte maturation remain major bottlenecks limiting blastocyst yield. This study investigated the role of inhibin in Wagyu oocyte competence through two independent proof-of-concept approaches. In the in vivo active immunization model, thirty Wagyu donors were immunized with a recombinant inhibin protein (INHA group), resulting in a significant increase in the number of recovered cumulus–oocyte complexes (COCs) (461 vs. 279, p < 0.05) and the proportion of high-quality oocytes compared to controls. Oocytes from the INHA group exhibited improved cytoplasmic maturation and mitochondrial function, characterized by higher membrane potential (ΔΨm, JC-1 ratio: 1.55 ± 0.06 vs. 0.83 ± 0.08, p < 0.05), elevated ATP content (2.35 ± 0.07 vs. 1.63 ± 0.03 pmol/oocyte, p < 0.05), and increased NADPH levels. Furthermore, the INHA group showed significantly reduced reactive oxygen species (ROS) accumulation and an increased GSH/GSSG ratio (8.48 ± 0.18 vs. 6.25 ± 0.09, p < 0.05), indicating restored redox homeostasis. Independently, in the in vitro anti-inhibin antibody (AIA) supplementation model, AIA supplementation during oocyte maturation significantly improved the nuclear maturation rate (92.96% ± 1.04%), blastocyst formation rate (56.63% ± 2.36%), and total cell number compared to controls (p < 0.05). Notably, AIA-derived blastocysts achieved a significantly higher pregnancy rate (78.65% ± 1.57%) following transfer. Collectively, these findings demonstrate that targeting inhibin mitigates oxidative injury and stabilizes mitochondrial bioenergetics, providing two distinct, physiology-based strategies for optimizing Wagyu oocyte yield and embryo production. Full article

Abiotic stresses severely constrain crop productivity by disrupting cellular redox homeostasis and hormone signaling. Although individual stresses differ in origin, plant responses converge on a conserved regulatory system centered on reactive oxygen species (ROS) and phytohormone crosstalk. Controlled ROS production in chloroplasts, mitochondria and the apoplast functions as a signaling mechanism that interacts dynamically with abscisic acid, auxin, ethylene, jasmonate and cytokinin pathways through shared regulatory nodes, including nicotinamide adenine dinucleotide phosphate (NADPH) oxidases and redox-sensitive transcriptional cascades. Endogenous metabolites, including phenolics, terpenoids, carotenoids, alkaloids, polyamines, glutathione and signaling peptides, are embedded within this network and modulate its amplitude and sensitivity. In parallel, non-microbial biostimulants derived from seaweeds, higher plants, protein hydrolysates and humic substances have been widely reported to enhance crop performance under abiotic stress. However, mechanistic integration between biostimulant research and plant stress signaling remains limited. In this review, we propose that terrestrial plant- and algal-derived biostimulants act not as external substitutes for hormones or antioxidants but as modulators of endogenous ROS–hormone signaling hubs. We first synthesize the current understanding of redox–hormone integration under abiotic stress, then examine endogenous metabolites as intrinsic regulators of this network, followed by an analysis of biostimulants in relation to shared regulatory nodes. By positioning biostimulant action within the established redox–hormone network, we provide a mechanistic framework that links stress biology with agronomic application and supports rational strategies to enhance crop resilience. Full article

Gelatin hydrolysate (GH), a bioactive compound derived from collagen, has demonstrated potential therapeutic benefits in various medical conditions. However, its effects on chronic cerebral hypoperfusion-induced vascular dementia remain underexplored. This study aimed to investigate the anti-oxidative stress effects of GH in alleviating brain damage and cognitive impairment in CCH-induced rats. Male Wistar rats underwent bilateral common carotid artery occlusion to induce CCH and were randomly divided into five groups: (1) sham, (2) 2-vessel occlusion (2VO), (3) 2VO + 250 mg/kg GH, (4) 2VO + 500 mg/kg GH, and (5) 2VO + piracetam. Treatments were administered for 35 days of post-operation. GH treatment significantly mitigated oxidative stress, as evidenced by reduced levels of reactive oxygen species (ROS), nitric oxide (NO), and the expression of 4-hydroxynonenal (4-HNE) and NADPH oxidase 4 (NOX4). Furthermore, GH exhibited antioxidant activity by upregulating superoxide dismutase (SOD) levels via nuclear factor E2-related factor 2 (Nrf-2) activation. This, in turn, reduced neuronal apoptosis by decreasing Bax and cleaved-caspase 3 levels and increasing Bcl-2 expression. Additionally, GH treatment ameliorated Tau protein hyperphosphorylation and improved synaptic function. Overall, GH exerted neuroprotective effects against oxidative stress-related neuronal damage and enhanced neuroplasticity, learning, and memory in rats with CCH-induced cognitive impairment. Full article

Vein graft disease remains a significant limitation to the long-term patency of venous conduits following coronary artery bypass grafting. Early oxidative stress, triggered by ischaemia–reperfusion injury and haemodynamic changes following the implantation of veins into the arterial circulation, disrupts endothelial integrity and initiates inflammation, apoptosis, and maladaptive remodelling. The KEAP1-NRF2 axis is a central regulator of cellular antioxidant responses; however, its role in the development of vein graft disease remains poorly defined. This narrative review aimed to summarise what is known about NRF2/KEAP1 signalling in modulating vein graft pathology. Methods: A systematic search of PubMed was conducted to identify original research studies examining the NRF2/KEAP1 pathway in human saphenous vein tissue in vivo or ex vivo. Narrative synthesis was performed due to limited evidential availability and study heterogeneity. Results: Only one study has directly evaluated NRF2 pathway activation directly in human saphenous vein tissue, and it demonstrated that Protandim (a herbal dietary supplement) treatment increased antioxidant enzyme activity and reduced oxidative stress markers, including superoxide and 4-hydroxynonenal, both known activators of MAPK-dependent smooth muscle proliferation. Adjacent studies in other cells and tissues reveal that NRF2 intersects with multiple pathways central to vein graft pathology: it suppresses NFκB-mediated inflammation, modulates eNOS-NO signalling, inhibits NADPH oxidase expression, regulates MAPK activation, and influences angiogenic responses. However, context-dependent activation of NRF2 under arterial cyclic stretch can paradoxically drive proliferation through p62-mediated KEAP1 sequestration and enhanced glutathione synthesis. Conclusions: The NRF2/KEAP1 pathway serves as a central integrator of oxidative stress responses that directly intersect with established mechanisms of intimal hyperplasia and pathological angiogenesis. Post-translational KEAP1 inhibition may offer a targeted intervention point to limit these processes. Critical gaps remain regarding our understanding of the role of NRF2 in human saphenous vein under physiological arterial conditions and sex-specific pathway regulation. Mechanistic studies in vein-specific models are essential for advancing our understanding and any potential therapeutic translation. Full article

Hyperuricemia is associated with liver dysfunction, yet its molecular mechanisms remain unclear. This study investigated high uric acid (HUA)-induced hepatocyte injury using a hyperuricemia mouse model (HUM) and uric acid (UA)-treated L02 cells. HUM exhibited elevated aspartate aminotransferase (AST)/alanine aminotransferase (ALT) and pathological liver changes. Transmission electron microscopy (TEM) confirmed ferroptotic hallmarks, including mitochondrial shrinkage and increased membrane density. UA exposure upregulated NADPH oxidase 4 (NOX4), increased reactive oxygen species (ROS), and promoted lipid peroxidation (LPO), accompanied by intracellular Fe²⁺ accumulation. Mechanistically, UA increased hypoxia-inducible factor-2α (HIF-2α) expression, subsequently upregulating iron transporters divalent metal transporter 1 (DMT1) and transferrin receptor (TFRC). Deferoxamine (DFO) treatment effectively reversed Fe²⁺ overload and alleviated oxidative stress. Notably, pharmacological inhibition or genetic knockdown of HIF-2α specifically suppressed DMT1 upregulation and restored iron homeostasis, while TFRC expression remained unaffected. Blocking the HIF-2α/DMT1 axis significantly reduced LPO and mitochondrial dysfunction. These findings demonstrate that HUA induces hepatocyte ferroptosis through HIF-2α-mediated DMT1 upregulation, leading to Fe²⁺ overload and mitochondrial impairment. This study identifies the HIF-2α/DMT1 pathway as a key driver of HUA-induced liver injury and a potential therapeutic target. Full article

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are central regulators of monocyte and macrophage biology, shaping their survival, differentiation, migration, and effector functions. In monocytes and macrophages, ROS and RNS arise from endogenous sources, such as mitochondria, NADPH oxidases, and myeloperoxidase, and from exogenous stimuli including pathogens, damaged tissues, and environmental oxidants. These reactive intermediates converge on redox-sensitive pathways such as NF-κB, Nrf2/HO-1, mitochondrial ROS signalling, and the NLRP3 inflammasome, thereby integrating metabolic stress with inflammatory activation. Redox balance is a key determinant of macrophage polarization: heightened ROS and RNS production drives pro-inflammatory M1 programs, whereas tightly regulated oxidative signalling supports M2 phenotypes associated with tissue repair and resolution. In chronic inflammatory disorders, notably atherosclerosis, oxidative stress amplifies monocyte recruitment, foam-cell formation, plaque instability, and maladaptive immunometabolic responses. The aim of this review is to recapitulate the major sources and functions of ROS and RNS in monocytes and macrophages and to synthesize current evidence on how these pathways collectively maintain or disrupt immune homeostasis. We further highlight emerging therapeutic strategies, such as NOX inhibitors, mitochondrial-targeted antioxidants, and Nrf2 activators, that seek to restore redox balance and offer promising avenues for the treatment of cardiovascular and immune-mediated diseases. Full article

Cofactors are small molecules or ions that participate in enzymatic reactions as essential carriers of electrons, atoms, or functional groups, thereby governing cellular redox balance and energy metabolism. In the yeast Saccharomyces cerevisiae, the availability of cofactors such as NAD(H), NADP(H), CoA, and acetyl-CoA directly influences the flux through biosynthetic pathways leading to aroma-active compounds. Esters and higher alcohols are the two most important families of volatile flavor compounds in fermented alcoholic beverages. Their synthesis is intimately linked to the intracellular levels and ratios of these cofactors. This review summarizes recent progress in cofactor engineering strategies aimed at modulating the production of esters, higher alcohols, and 2,3-butanediol in S. cerevisiae. We discuss the underlying metabolic pathways, highlight key studies that manipulate cofactor pools to redirect carbon flux, and examine emerging tools (e.g., riboswitches, fine-tuned promoter systems) that enable precise cofactor balancing. Finally, we outline future challenges and opportunities for applying cofactor engineering to design yeast cell factories with tailored flavor profiles. Full article

Fetal bovine serum (FBS) is the standard supplement for cell culture, yet we previously demonstrated that it drives hyper-proliferation and phenotypic drift in Madin–Darby canine kidney (MDCK) cells, compromising their epithelial identity and ciliogenesis. In contrast, a modified chicken embryo extract (CEE) preserved these intrinsic properties, maintaining a stable and physiologically relevant phenotype. To elucidate the metabolic mechanisms driving these distinct cellular fates, we performed a comparative analysis of redox status and metabolomic profiles. We found that FBS forces a metabolic shift toward oxidative phosphorylation, resulting in mitochondrial stress characterized by elevated mitochondrial reactive oxygen species (mtROS), calcium overload, and the accumulation of uremic toxins like hippuric acid. Conversely, CEE established a balanced redox environment. Although CEE induced higher intracellular signaling ROS via NADPH oxidase 1/2, it prevented oxidative damage by upregulating antioxidant transcription factors, such as nuclear factor erythroid 2-related factor 2, and enzymes such as Mn superoxide dismutase. Additionally, metabolomic analysis revealed that CEE is enriched with antioxidants (ascorbic acid, proline) and signaling molecules (5-hydroxyindole-3-acetic acid). These findings indicate that while FBS imposes a metabolic burden leading to cellular stress, CEE provides a favorable metabolic microenvironment that supports homeostasis and epithelial integrity, validating its superiority as a culture supplement. Full article

Hydrogen peroxide (H₂O₂) is a key extracellular redox signaling molecule that regulates diverse physiological processes, including immune cell activation and proliferation. However, its role in maintaining extracellular redox balance and mediating intercellular signaling remains underexplored. In this study, we investigated how extracellular depletion of H₂O₂ by catalase modulates intracellular signaling pathways in macrophages. Catalase treatment effectively depleted extracellular H₂O₂ in a concentration- and time-dependent manner, leading to activation of mitogen-activated protein kinase (MAPK) pathways, including extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38, as well as nuclear translocation of the nuclear factor κB (NF-κB) p65 subunit. Perturbation of extracellular redox status resulted in robust upregulation of inflammatory and oxidative stress–related genes, including cyclooxygenase-2 (COX-2), C-C motif chemokine ligand 5 (CCL5), inducible nitric oxide synthase (iNOS), and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. This transcriptional response was accompanied by increased nitric oxide (NO) production and enhanced nuclear translocation and DNA-binding activity of nuclear factor erythroid 2–related factor 2 (Nrf2). Mechanistically, our data suggest that NO-mediated S-nitrosylation contributes to activation of the cellular antioxidant response. In addition, catalase-mediated depletion of extracellular H₂O₂ significantly (p < 0.05) suppressed 5-bromo-2′-deoxyuridine (BrdU) incorporation, indicating inhibition of macrophage proliferation. Together, these findings demonstrate that extracellular H₂O₂ functions as a physiological redox signal that maintains cellular homeostasis, and that its removal triggers a coordinated intracellular response involving both inflammatory activation and antioxidant defense. This study highlights the critical role of extracellular redox balance in shaping macrophage function and provides mechanistic insight into how changes in the oxidative environment regulate downstream immune signaling pathways. Full article

Background/Objectives: Xu Chunfu’s Modified Xianglian Pill (XXLP) has been used for centuries in Chinese medicine to treat “diarrhea” and “dysentery,” conditions analogous to modern ulcerative colitis (UC). However, the scientific basis for its efficacy and mechanisms remains unclear. Methods: The chemical composition of XXLP was analyzed via UPLC-ESI-MS/MS. A colitis mouse model was established using DSS, and the therapeutic effects were assessed based on body weight, disease activity index (DAI), colon length, and histopathology. Inflammatory cytokines were measured using ELISA. Proteomic analysis and molecular docking identified key targets, which were validated using LPS-induced HT-29 cells via Western blot (WB), qRT-PCR, immunofluorescence (IF), and transmission electron microscopy (TEM). Gut microbiota composition was analyzed using 16S rRNA gene sequencing. Results: Analysis of XXLP led to the detection of 373 compounds. XXLP significantly improved colitis symptoms, including weight loss and colon shortening, and reduced the concentrations of inflammatory markers IL-1β, IL-18, TNF-α, and IL-6. Proteomics and molecular docking identified NADPH oxidase 2 (NOX2) as a key target of XXLP intervention in mice with colitis. qRT-PCR, WB, IF, and TEM results further confirmed that XXLP effectively suppressed the expression of NOX2 and its associated protein levels. Sequencing analysis of 16S rRNA showed that XXLP significantly increased the relative abundance of beneficial bacterial genera (Muribaculaceae and Ruminococcaceae) while markedly reducing the levels of harmful bacteria (Enterobacteriaceae). Correlation analysis revealed that specific microorganisms were correlated with NOX2-related protein expression and severity of colonic inflammation. Conclusions: XXLP effectively alleviates colitis by suppressing inflammatory responses. Its mechanism involves regulating the NOX2/ROS/mitochondria/NLRP3 axis and altering gut microbiota composition, providing novel insights for colitis treatment. Full article

During the early pupal stage in butterflies, the peripheral portion of wing tissue undergoes apoptosis to finalize adult wing morphology, and wing color patterns are determined coordinately. We hypothesized that the development of wing morphology and color patterns may involve NADPH oxidase (NOX). To test this hypothesis, we treated pupae of the blue pansy butterfly Junonia orithya with NOX inhibitors. When VAS2870, isuzinaxib, or diphenyleneiodonium chloride (DPI) in dimethyl sulfoxide (DMSO) was topically applied to the pupal wing tissue via the sandwich method, wing morphology and color pattern elements, including eyespots, parafocal elements, submarginal bands, and marginal bands, were severely deformed as if the marginal area were surgically removed. The topical application of DMSO alone mildly deformed and enlarged eyespots without affecting other color patterns and wing morphology. When systemically injected into pupae, VAS2870 increased eyespots in males but decreased eyespots in females, likely due to the sexual dimorphism of this species. These results suggest that NOX and probably hydrogen peroxide play important roles in wing morphogenesis and color pattern fate determination in butterfly wings. Sexually dimorphic eyespot size in this species may also be explained by the sexually differential activities of NOX. Full article

Diabetic nephropathy (DN) is a serious complication in diabetic patients, leading to kidney dysfunction and ultimately end-stage renal disease. Although several pharmacological agents have been developed, treating DN remains challenging due to its complex and multifaceted pathogenesis. Endoplasmic reticulum (ER) stress plays a crucial role in DN pathology; however, the molecular mechanisms underlying reduced ER stress remain poorly understood. This study investigated the protective effects of 4-phenylbutyrate (4-PBA), an ER stress inhibitor, on DN and the related regulatory molecules through gene expression network analysis. A C57BL/6 mouse model of DN was used in combination with a high-fat diet and streptozotocin after unilateral nephrectomy and treated with 4-PBA by intraperitoneal injection for 6 weeks. The 4-PBA treatment effectively improves DN-induced renal structural and functional abnormalities by reducing albuminuria, podocyte loss, glomerular and tubular injury, and renal inflammation and cell death. These changes induced by 4-PBA were associated with decreased expression of ER stress markers and increased autophagy activities in diabetic kidneys. Importantly, 4-PBA reduced components of the complement C1q pathway, the NADPH oxidase complex, and chemokines, thereby attenuating chronic renal dysfunction. Conclusively, inhibition of ER stress is a promising pharmacological target for treating patients with DN. 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