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Reactive oxygen species (ROS) play a crucial role in regulating numerous functions in organisms. Among the key regulators of ROS production are NADPH oxidases, primarily referred to as respiratory burst oxidase homologues (RBOHs). However, our understanding of whether and how pathogens directly target RBOHs has been limited. In this study, we revealed that the effector protein RipBJ, originating from the phytopathogenic bacterium Ralstonia solanacearum, was present in low‐ to medium‐virulence strains but absent in high‐virulence strains. Functional genetic assays demonstrated that the expression of ripBJ led to a reduction in bacterial infection. In the plant, RipBJ expression triggered plant cell death and the accumulation of H2O2, while also enhancing host defence against R. solanacearum by modulating multiple defence signalling pathways. Through protein interaction and functional studies, we demonstrated that RipBJ was associated with the plant's plasma membrane and interacted with the tomato RBOH known as SlWfi1, which contributed positively to RipBJ's effects on plants. Importantly, SlWfi1 expression was induced during the early stages following R. solanacearum infection and played a key role in defence against this bacterium. This research uncovers the plant RBOH as an interacting target of a pathogen's effector, providing valuable insights into the mechanisms of plant defence. Summary Statement: This study demonstrates that a tomato plasma membrane‐bound NADPH oxidase is a direct interactor of a bacterial effector protein to mediate plant defence, providing important new information on the interplay between this devastating pathogen and its host plant. [ABSTRACT FROM AUTHOR]

The increased production of reactive oxygen species (ROS) by human neutrophils can lead to oxidative imbalances and several diseases, such as inflammatory bowel disease (IBD). Opuntia ficus-indica (O. ficus-indica) is rich in bioactive substances with anti-inflammatory properties. This study aimed to identify the bioactive compounds present in aqueous cladodes extract (ACE) of O. ficus-indica using high-performance liquid chromatography (HPLC) and to test its effects on human neutrophil inflammatory functions and on ulcerative colitis (UC) induced by acetic acid (Aa) in rats. ROS production and degranulation by neutrophils were assessed by luminol-amplified chemiluminescence, enzymatic techniques, and western blotting. In vivo, the experiment involved seven groups of rats: a negative control group (NaCl), the acetic acid group (Aa), and groups treated with oral sulfasalazine (150 mg/kg) or various doses of ACE for 7 days. Colonic lesions were induced by an intra-rectal Aa injection, and inflammation was assessed. HPLC analysis identified gallic acid, catechin, caffeic acid, and ferulic acid as major compounds in ACE. In vitro, ACE inhibited neutrophil ROS production, including superoxide anion produced by NADPH oxidase, and significantly reduced myeloperoxidase activity and neutrophil degranulation. In vivo, ACE protected rats from Aa-induced histopathological damage of the colonic mucosa, significantly increased catalase, superoxide dismutase and reduced glutathione levels, and significantly suppressed the increases of plasma cytokines (TNF-α and IL-1β) observed in the Aa group. In conclusion, O. ficus-indica ACE has significant anti-inflammatory properties by restoring oxidative balance, indicating that it could be a potential source of therapeutic agents for inflammatory diseases, particularly UC. [ABSTRACT FROM AUTHOR]

Myocardial fibrosis is a critical concern in clinical medicine. This study explores the potential of odoratin as a treatment for myocardial fibrosis and investigates its underlying mechanisms. In vitro experiments involved stimulating primary mouse cardiomyocytes with TGF‐β1, followed by odoratin treatment, to assess levels of reactive oxygen species (ROS) and nitric oxide (NO). In vivo, a mouse model of myocardial fibrosis was established using abdominal aortic constriction (AAC) and treated with odoratin. ROS and NO levels in myocardial tissue were then evaluated. Immunofluorescence and Western blotting analysis showed that odoratin reduced excess ROS, enhanced NO production and decreased fibrosis‐related protein expression in vitro. In vivo, odoratin significantly improved cardiac function, reduced ROS, increased NO levels and mitigated fibrosis in AAC‐induced mice. Both in vitro and in vivo, odoratin inhibited the expression of NADPH oxidase 4 and EZH2, while promoting the expression of phosphorylated endothelial nitric oxide synthase (p‐eNOS) and PPARγ. The anti‐fibrotic effects of odoratin were reversed by PPARγ antagonism, and EZH2 overexpression diminished PPARγ activation by odoratin. These findings suggest that odoratin may combat myocardial fibrosis by balancing ROS and NO through PPARγ activation, with EZH2 inhibition likely playing a key regulatory role. [ABSTRACT FROM AUTHOR]

Purpose: Chronic granulomatous disease (CGD) is an inherited immunodeficiency caused by pathogenic variants of genes encoding the enzyme complex NADPH oxidase. In countries where tuberculosis (TB) is endemic and the Bacillus Calmette–Guérin (BCG) vaccine is routinely administered, mycobacteria are major disease-causing pathogens in CGD. However, information on the clinical evolution and treatment of mycobacterial diseases in patients with CGD is limited. The present study describes the adverse reactions to BCG and TB in Mexican patients with CGD. Methods: Patients with CGD who were evaluated at the Immunodeficiency Laboratory of the National Institute of Pediatrics between 2013 and 2024 were included. Medical records were reviewed to determine the clinical course and treatment of adverse reactions to BCG and TB disease. Results: A total of 79 patients with CGD were included in this study. Adverse reactions to BCG were reported in 55 (72%) of 76 patients who received the vaccine. Tuberculosis was diagnosed in 19 (24%) patients. Relapse was documented in three (10%) of 31 patients with BGC-osis and six (32%) of 19 patients with TB, despite antituberculosis treatment. There was no difference in the frequency of BCG and TB disease between patients with pathogenic variants of the X-linked CYBB gene versus recessive variants. Conclusions: This report highlights the importance of considering TB in endemic areas and BCG complications in children with CGD to enable appropriate diagnostic and therapeutic approaches to improve prognosis and reduce the risk of relapse. [ABSTRACT FROM AUTHOR]

The roots and rhizomes of Panax ginseng C.A. Mey are commonly used herbal medicine in Asian countries. These components contain a large number of secondary metabolites known as ginsenosides, which serve as primary active ingredient. Environmental factors significantly influence the production of secondary metabolites, which are crucial for enhancing plant adaptability to ecological stress. P. ginseng is a shady plant that thrives in a constantly humid and temperate environment. However, it cannot withstand excessive moisture, making soil moisture a significant ecological stress affecting P. ginseng survival. In this study, we applied a water spray to maintain a water-saturated surface on 5-year-old fresh P. ginseng roots for a duration of 5 days, to establish a short-term water stress condition. The results revealed a notable increase in superoxide anion (O2·-), hydrogen peroxide (H2O2), and NADPH oxidase (NOX) activity (p < 0.01), as well as malondialdehyde (MDA) contents (p < 0.01) in both the main root and fibrous root of P. ginseng. Additionally, superoxide dismutase (SOD), catalase (CAT), peroxides (POD), ascorbate peroxidase (APX) and glutathione reductase (GR) activities also elevated significantly under water stress (p < 0.01). Ascorbic acid (AsA), glutathione (GSH) and oxidized glutathione (GSSG) contents also showed a marked increase (p < 0.01). The main root treated with water showed the most positive impact on the 5th day. Water stress boosted the activities of key enzymes including 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), farnesyl pyrophosphate synthase (FPS), squalene synthase (SS), squalene epoxidase (SE), and dammarenediol-II synthase (DS) involved in the ginsenoside biosynthesis pathway (p <0.01). This resulted in a significant an increase in the level of ginsenosides Rg1, Rb1, Rf, Rg2+Rh1, Rc, and Rb3, by 42.4%, 21.0%, 15.7%, 157.9%, 18.3%, and 10.6% respectively, and an increase of 40.1% in total saponins content. Similarly, the fibrous root changes in the treated sample showed the most positive impact on the 4th day. Specifically, Rg1, Re, Rb1, Rf, Rg2+Rh1, Rc, Ro, and Rb2 increased by 41.8%, 20.5%, 17.3%, 84.3%, 30.7%, 35.6%, 8.6%, and 7.6%, respectively, and an increase of 4.2% in total saponins content. Furthermore, 1,3-disphosphoglycerate (1,3-DPG) contents and phosphoenolpyruvate carboxylase (PEPC) activities, which are key intermediate of primary metabolism, were significantly elevated under water stress (p < 0.01). This indicates that the primary source of the raw materials used in the biosynthesis of secondary metabolites is sugars. Pharmacodynamic analysis demonstrated that water stress could increase the contents of ginsenosides, improve the quality of ginseng, and enhance the efficacy of ginseng root to a certain extent. [ABSTRACT FROM AUTHOR]

Objectives: Allergic rhinitis (AR) is a complex disorder with variable pathogenesis. Increasing evidence suggests that the LRRC8A is involved in maintaining cellular stability, regulating immune cell activation and function, and playing significant roles in inflammation. However, the involvement of LRRC8A in AR inflammation and its underlying mechanisms remain unclear. Methods: LRRC8A expression in AR patients, confirmed by qRT-PCR and Western blotting, was analyzed to investigate its relationship with the clinical characteristics of AR patients. In vitro, IL-13 stimulated HNEpCs to establish a Th2 inflammation model, with subsequent LRRC8A knockout or overexpression. NOX1/NOX4 inhibitor (GKT137831) and chloride channel inhibitor (DCPIB) were utilized to investigate AR development mechanisms during LRRC8A overexpression. An OVA-induced AR model with nasal mucosa LRRC8A knockdown confirmed LRRC8A's regulatory role in AR inflammation. Results: LRRC8A mRNA and protein levels were significantly elevated in AR patients, positively correlating with NADPH oxidase subunits and Th2 inflammatory markers. In vitro, IL-13 stimulation of HNEpCs resulted in upregulation of LRRC8A and increased expression of NOX1, NOX4, and p22phox, along with mitochondrial dysfunction and NF-κB pathway activation. The knockout of LRRC8A reversed these effects. In nasal mucosal epithelial cells, DCPIB and GKT137831 completely blocked mitochondrial dysfunction caused by the overexpression of LRRC8A, which led to up-regulation of NOX1, NOX4, and p22phox. In vivo, knocking down LRRC8A reduced eosinophil infiltration, downregulated the expression of NOX1, NOX4, p22phox IL-4, IL-5, and IL-13, and decreased NF-κB pathway activation. Conclusion: LRRC8A drives the upregulation of NOX1, NOX4, and p22phox, leading to ROS overproduction and mitochondrial dysfunction. It also activates NF-κB, ultimately leading to nasal mucosal epithelial inflammation. LRRC8A may be a potential target for the treatment of AR. [ABSTRACT FROM AUTHOR]

Cross‐presentation by MHCI is optimally efficient in type 1 dendritic cells (DC) due to their high capacity for antigen processing. However, through specific pathways, other DCs, such as type 2 DCs and inflammatory DCs (iDCs) can also cross‐present antigens. FcγR‐mediated uptake by type 2 DC and iDC subsets mediates antibody‐dependent cross‐presentation and activation of CD8+ T cell responses. Here, an important role for the p84 regulatory subunit of PI3Kγ in mediating efficient cross‐presentation of exogenous antigens in otherwise inefficient cross‐presenting cells, such as type 2 DCs and GM‐CSF‐derived iDCs is identified. FcγR‐mediated cross‐presentation is shown in type 2 and iDCs depend on the enzymatic activity of the p84/p110γ complex of PI3Kγ, which controls the activity of the NADPH oxidase NOX2 and ROS production in murine spleen type 2 DCs and GM‐CSF‐derived iDCs. In contrast, p84/p110γ is largely dispensable for cross‐presentation by type 1 DCs. These findings suggest that PI3Kγ‐targeted therapies, currently considered for oncological practice, may interfere with the ability of type 2 DCs and iDCs to cross‐present antigens contained in immune complexes. [ABSTRACT FROM AUTHOR]

Background: The present study investigated the function of G protein-coupled receptor kinase 2 (GRK2) in acute liver injury (ALI) by cisplatin, and investigated the protective effect of pharmacological inhibition of GRK2. Methods: ALI models were generated in global adult hemizygous (ALI-Grk2±) mice and wild-type (WT) mice. Liver biochemistry parameters and histopathology were used to evaluate the severity of ALI and the protective effect of pharmacological inhibition of GRK2. GRK2-siRNA was used to knock down the expression of GRK2 in AML12 cells in vitro. Results: ALI model mice exhibited increased blood levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and abnormal liver pathology accompanied by imbalanced L-glutathione (GSH) levels. Cisplatin administration upregulated GKR2, p-GRK2 and NADPH oxidase 4 (NOX4) expression in the liver tissues of ALI model mice. Compared to WT mice injected with cisplatin, Grk2± mice that received cisplatin showed significant improvements in liver function and pathological performance, decreased NOX4 levels, reduced endoplasmic reticulum (ER) stress, and diminished liver cell apoptosis. In vitro, the transfection of AML12 cells with siRNA significantly reduced NOX4 expression and inhibited cisplatin-induced reactive oxygen species production, ER stress (increased levels of GRP94, GRP78, p-elF2α and CHOP) and apoptotic death. Moreover, pharmacological treatment with drugs that inhibit GRK2 (CP-25 or paroxetine) significantly ameliorated cisplatin-induced ALI by improving liver pathological manifestations, inhibiting oxidative stress and ER stress, and reducing liver cell apoptosis. Similar results were observed in vitro. Conclusions: GRK2 mediates the development of cisplatin-induced ALI by modulating NOX4 and ER stress. Pharmacological inhibition of GRK2 with CP-25 or paroxetine effectively alleviated ALI. GRK2 can be used as a potential target for the prevention and treatment of liver injury. [ABSTRACT FROM AUTHOR]

Oxidative stress is linked to the pathogenesis of Alzheimer's disease (AD), a neurodegenerative disorder marked by memory impairment and cognitive decline. AD is characterized by the accumulation of amyloid-beta (Aβ) plaques and the formation of neurofibrillary tangles (NFTs) of hyperphosphorylated tau. AD is associated with an imbalance in redox states and excessive reactive oxygen species (ROS). Recent studies report that NADPH oxidase (NOX) enzymes are significant contributors to ROS generation in neurodegenerative diseases, including AD. NOX-derived ROS aggravates oxidative stress and neuroinflammation during AD. In this review, we provide the potential role of all NOX isoforms in AD pathogenesis and their respective structural involvement in AD progression, highlighting NOX enzymes as a strategic therapeutic target. A comprehensive understanding of NOX isoforms and their inhibitors could provide valuable insights into AD pathology and aid in the development of targeted treatments for AD. [ABSTRACT FROM AUTHOR]

Preeclampsia (PE) is associated with increased angiotensin II sensitivity and poor neurological outcomes marked by temporal loss of neural control of blood pressure. Yet the role of centrally expressed angiotensin II type 1 receptor (AT1R) within the paraventricular nucleus of the hypothalamus (PVN) in the PE model is not understood. In a PE rat model with reduced placental perfusion pressure (RUPP) induced on gestational day 14 (GD14), the PVN expression and cellular localization of AT1R were assessed using immunofluorescence and western blotting. The sensitivity of RUPP to acute angiotensin II infusion was assessed. AT1R was antagonized by losartan (100 µg/kg/day) for 5 days intracerebroventricularly (ICV). Hemodynamic data and samples were collected on GD19 for further analysis. RUPP upregulated (p < 0.05) mRNA and protein of AT1R within the PVN and lowered (p < 0.05) circulating angiotensin II in rats. RUPP increased neural and microglial activation. Cellular localization assessment revealed that AT1R was primarily expressed in neurons and slightly in microglia and astrocytes. Infusion of 100 ng/kg as bolus increased the mean arterial pressure (MAP in mmHg) in both RUPP and Sham. ICV losartan infusion attenuated RUPP-increased MAP (113.6 ± 6.22 in RUPP vs. 92.16 ± 5.30 in RUPP + Los, p = 0.021) and the expression of nuclear transcription factor NF-κB, tyrosine hydroxylase (TH), NADPH oxidase 4 (NOX4) and reactive oxygen species (ROS) in the PVN. Our data suggest that centrally expressed AT1R, within the PVN, contributes to placental ischemia–induced hypertension in RUPP rats highlighting its therapeutic potential in PE. [ABSTRACT FROM AUTHOR]

Electronic cigarettes and heated tobacco products have seen significant growth in sales and usage in recent years. Initially promoted as potentially less harmful alternatives to traditional tobacco, recent scientific evidence has raised serious concerns about the risks they pose, particularly in relation to atherosclerosis. While atherosclerosis has long been associated with conventional tobacco smoking, emerging research suggests that electronic cigarettes and heated tobacco may also contribute to the development of this condition and related cardiovascular complications. In a narrative review, we examined the potential effects of heated tobacco products and electronic cigarettes on oxidative stress and atherosclerosis. Several studies have shown that e-cigarettes and heated tobacco increase oxidative stress through the activation of enzymes such as NADPH oxidase. One of the primary effects of these products is their pro-thrombotic and pro-atherosclerotic impact on endothelial cells and platelets, which promotes inflammatory processes within the arteries. Furthermore, the chemicals found in electronic cigarette liquids may exacerbate inflammation and cause endothelial dysfunction. Furthermore, through a systematic review, we analyzed the effects of chronic exposure to electronic and heated tobacco cigarettes on endothelial function, as assessed by brachial flow-mediated dilation (FMD). Although electronic cigarettes and heated tobacco cigarettes are often perceived as safer alternatives to traditional smoking, they could still present risks to cardiovascular health. It is essential to raise public awareness about the potential dangers associated with these products and implement protective measures, particularly for young people. [ABSTRACT FROM AUTHOR]

Oxidative stress is a primary contributor to cerebral ischemia/reperfusion (CI/R) injury, and the use of antioxidants represents a crucial therapeutic strategy for managing CI/R injury. This study aims to explore the antioxidant effects of benzyl ferulate on CI/R injury and elucidate its underlying mechanisms. In vivo models of CI/R injury and hypoxia/reoxygenation (H/R) injury in SH‐SY5Y cells were established, followed by treatment with benzyl ferulate. The extent of oxidative stress was assessed through evaluations of neurobiological function, cerebral infarct volume, reactive oxygen species (ROS), apoptosis levels, etc. Results indicated that benzyl ferulate significantly downregulated the expression of NADPH oxidase 2 (NOX) 2/NOX4 while upregulating miRNAs (652/532/92b) in CI/R rats or SH‐SY5Y cells. It also reduced total NOX enzyme activity, enhanced superoxide dismutase (SOD) activity, decreased ROS and malondialdehyde (MDA) production, and inhibited cleaved caspase‐3 and Bax expression—ultimately leading to reduced cell apoptosis. Benzyl ferulate effectively mitigates oxidative stress injuries of middle cerebral artery occlusion (MCAO) rats or SH‐SY5Y cells subjected to H/R, and its mechanism appears to involve modulation of the miRNAs (652/532/92b)/NOX2/4 axis. This study first proved that benzyl ferulate is a promising antioxidant candidate for treating CI/R injury. [ABSTRACT FROM AUTHOR]

Black spot, one of the major diseases of kiwifruit, is caused by Alternaria alternata. A comprehensive investigation into its pathogenicity mechanism is imperative in order to propose a targeted and effective control strategy. The effect of L-arginine on the pathogenicity of A. alternata and the underlying mechanisms were investigated. The results showed that treatment with 5 mM L−1 of L-arginine promoted spore germination and increased the colony diameter and lesion diameter of A. alternata in vivo and in vitro, which were 23.1% and 9.3% higher than that of the control, respectively. Exogenous L-arginine treatment also induced endogenous L-arginine and nitric oxide (NO) accumulation by activating nitric oxide synthase (NOS), arginine decarboxylase (ADC) and ornithine decarboxylase (ODC). In addition, exogenous L-arginine triggered an increase in reactive oxygen species (ROS) levels by activating the activity and inducing gene expression upregulation of NADPH oxidase. The hydrogen peroxide (H2O2) and superoxide anion (O2.−) levels were 15.9% and 2.2 times higher, respectively, than in the control group on the second day of L-arginine treatment. Meanwhile, antioxidant enzyme activities and gene expression levels were enhanced, including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione peroxidase (GPX), and glutathione reductase (GR). In addition, exogenous L-arginine stimulated cell wall-degrading enzymes in vivo and in vitro by activating gene expression. These results suggested that exogenous L-arginine promoted the pathogenicity of A. alternata by inducing the accumulation of polyamines, NO, and ROS, and by activating systems of antioxidants and cell wall-degrading enzymes. The present study not only revealed the mechanism by which low concentrations of L-arginine increase the pathogenicity of A. alternata, but also provided a theoretical basis for the exclusive and precise targeting of A. alternata in kiwifruit. [ABSTRACT FROM AUTHOR]

Background/Objectives: This study aimed to analyze the chemical composition and biological activities of Artemisia absinthium L. essential oil, focusing on its antioxidant and enzyme inhibition (α-amylase and urease) properties. Additionally, in vitro pharmacokinetic and pharmacodynamic evaluations were conducted through in silico molecular docking and BOILED-Egg models to assess its therapeutic potential and its potency in treating oxidative-stress-related diseases. Methods: The essential oil was isolated by the hydrodistillation (HD) of fresh plant material, and volatiles released from dried plant material were sampled via headspace solid-phase microextraction (HS-SPME), followed by a phytochemical profiling analysis through the GC-MS tool. Antioxidant capacity was assessed using DPPH, ABTS, FRAP, and nitric oxide scavenging assays, while enzyme inhibition activities were tested against α-amylase and urease. Molecular docking and BOILED-Egg models were used to evaluate compound interactions with NADPH oxidase and predict pharmacokinetic behavior, respectively. Results: HS-SPME and HD yielded 46 and 25 compounds, respectively, primarily terpenoids represented by camphor (26.4%) and cis-davanone (18.0%) in HS-SPME, while in the HD essential oil, cis-davanone (60.2%) and chamazulene (10.8%) were most prevalent. The antioxidant assays showed a strong activity, with a total antioxidant capacity of 821.8 mg ascorbic acid Eq/gm. The essential oil inhibited urease by 86.7% and α-amylase by 81.8%. Molecular docking showed strong binding affinities with NADPH oxidase, supporting the antioxidant results. Conclusions:A. absinthium EO demonstrated potent antioxidant and enzyme inhibitory activities, suggesting its therapeutic potential for treating enzyme-related disorders like diabetes mellitus and its possible use as a cure for many oxidative-stress-related diseases, thus validating the folkloric use of this plant. [ABSTRACT FROM AUTHOR]

Morphine tolerance (MT) is currently a challenging issue related to intractable pain treatment. Studies have shown that reactive oxygen species (ROSs) derived from NADPH oxidase (NOX) and produced in response to endoplasmic reticulum (ER) stress participate in MT development. However, which NOX subtype initiates ER stress during MT development is unclear. NOX4 is mainly expressed on intracellular membranes, such as the ER and mitochondrial membranes, and its sole function is to produce ROS. Whether NOX4 is activated during MT development and the mechanisms underlying the association between NOX4 and ER stress during this process still need to be confirmed. In our study, we used the classic morphine‐tolerant rat model and evaluated the analgesic effect of intrathecally injected morphine through a hot water tail‐flick assay. Our research demonstrated for the first time that chronic morphine administration upregulates NOX4 expression in the spinal cord by activating three ER stress sensors, protein kinase RNA‐like ER kinase (PERK), inositol‐requiring enzyme 1 (IRE1) and activating transcription factor 6 (ATF6), subsequently leading to the activation of microtubule‐associated protein 1 light chain 3 b (LC3B) and P62 (a well‐known autophagy marker) in GABAergic neurons. Our results may suggest that regulating NOX4 and the key mechanism underlying ER stress or autophagy may be a promising strategy to treat and prevent MT development. [ABSTRACT FROM AUTHOR]

Acute myeloid leukaemia (AML) is a highly heterogeneous malignancy, with a poor 5-year overall survival rate of approximately 30%. Consequently, the search for novel therapeutic strategies is ongoing, and the identification of new vulnerabilities could accelerate progress. Oxidative stress and metabolic rewiring are established hallmarks of cancer, and recent evidence suggests that NADPH oxidases may regulate metabolism, potentially linking these two processes. Increasing research highlights the importance of NOX2 in AML, particularly its role in metabolic regulation. In this study, we investigated the effects of simultaneously inhibiting NOX2 and glycolysis in AML cells. Dual inhibition of NOX2 and glycolysis—by targeting hexokinase or lactate dehydrogenase (LDH)—significantly reduced cell proliferation, markedly impaired clonogenic potential, and induced extensive cell death in a broad panel of AML cell lines. Importantly, these findings were further validated in primary bone marrow samples derived from AML patients, where combined inhibition triggered similar potent anti-leukemic effects. Furthermore, the combined inhibition of NOX2 and LDH enhanced the efficacy of cytarabine (AraC), suggesting this approach could boost the effectiveness of conventional therapies. In an in vivo AML model, targeting NOX2 and LDH in myeloid progenitor cells delayed the onset of leukaemia and extended survival. In conclusion, our findings propose a novel therapeutic strategy for AML through the dual targeting of NOX2 and glycolysis. [ABSTRACT FROM AUTHOR]

Spreading depolarization (SD) causes a massive neuronal/glial depolarization, disturbs ionic homeostasis and deranges neuronal network function. The metabolic burden imposed by SD may also generate marked amounts of reactive oxygen species (ROS). Yet, proper optical tools are required to study this aspect with spatiotemporal detail. Therefore, we earlier generated transgenic redox indicator mice. They express in excitatory projection neurons the cytosolic redox-sensor roGFP, a reduction/oxidation sensitive green fluorescent protein which is ratiometric by excitation and responds reversibly to redox alterations. Using adult male roGFPc mice, we analyzed SD-related ROS production in CA1 stratum pyramidale of submerged slices. SD was induced by K+ microinjection, O2 withdrawal or mitochondrial uncoupling (FCCP). The extracellular DC potential deflection was accompanied by a spreading wavefront of roGFP oxidation, confirming marked neuronal ROS generation. Hypoxia-induced SD was preceded by a moderate oxidation, which became intensified as the DC potential deflection occurred. Upon K+-induced SD, roGFP oxidation slowly recovered within 10-15 min in some slices. Upon FCCPor hypoxia-induced SD, recovery was limited. Withdrawing extracellular Ca2+ markedly dampened the SD-related roGFP oxidation and improved its reversibility, confirming a key-role of neuronal Ca2+ load in SD-related ROS generation. Neither mitochondrial uncoupling, nor inhibition of NADPH oxidase or xanthine oxidase abolished the SD-related roGFP oxidation. Therefore, ROS generation during SD involves mitochondria as well as non-mitochondrial sources. This first-time analysis of SD-related ROS dynamics became possible based on quantitative redox imaging in roGFP mice, an advanced approach, which will contribute to further decipher the molecular understanding of SD in brain pathophysiology. [ABSTRACT FROM AUTHOR]

Understanding the interactions between fungal plant pathogens and host roots is crucial for developing effective disease management strategies. This study investigates the molecular mechanisms underpinning the chemotropic responses of the maize anthracnose fungus Colletotrichum graminicola to maize root exudates. Combining the generation of a deletion mutant with monitoring of disease symptom development and detailed analysis of chemotropic growth using a 3D-printed device, we identify the 7-transmembrane G-protein coupled receptor (GPCR) CgSte3 as a key player in sensing both plant-derived class III peroxidases and diterpenoids. Activation of CgSte3 initiates signaling through CgSo, a homolog to the Cell Wall Integrity Mitogen-Activated Protein Kinase (CWI MAPK) pathway scaffold protein identified in other filamentous fungi, facilitating the pathogen's growth towards plant defense molecules. The NADPH oxidase CgNox2 is crucial for peroxidase sensing but not for diterpenoid detection. These findings reveal that CgSte3 and CWI MAPK pathways are central to C. graminicola's ability to hijack plant defense signals, highlighting potential targets for controlling maize anthracnose. [ABSTRACT FROM AUTHOR]

Several reports, including our previous studies, indicate that hyperglycemia and diabetes mellitus exert differential effects on vascular function in males and females. This study examines sex differences in the vascular effects of type 2 diabetes (T2D) in an established monogenic model of obesity-induced T2D, Zucker Diabetic Fatty (ZDF) rats. Acetylcholine (ACh) responses were assessed in phenylephrine pre-contracted rings before and after apocynin, a NADPH oxidase (NOX) inhibitor. The mRNA expressions of aortic endothelial NOS (eNOS), and key NOX isoforms were also measured. We demonstrated the following: (1) diabetes had contrasting effects on aortic vasorelaxation in ZDF rats, impairing relaxation to ACh in females while enhancing it in male ZDF rats; (2) inhibition of NOX, a major source of superoxide in vasculature, restored aortic vasorelaxation in female ZDF rats; and (3) eNOS and NOX4 mRNA expressions were elevated in female (but not male) ZDF rat aortas compared to their respective leans. This study highlights sexual dimorphism in ACh-mediated vasorelaxation in the aorta of ZDF rats, suggesting that superoxide may play a role in the impaired vasorelaxation observed in female ZDF rats. [ABSTRACT FROM AUTHOR]

Thirteen components were identified in the methanol extract of Moricandia sinaica leaves (MSLE) through analysis utilizing HPLC-ESI-MS/MS., including flavonoids, anthocyanins, phenolic acids, and fatty acids. The methanol extract of M. sinaica leaves contained total phenolics and flavonoids (59.37 ± 2.19 mg GAE/g and 38.94 ± 2.72 mg QE/g), respectively. Furthermore, it revealed in vitro antioxidant properties as determined by the DPPH and FRAP assays, with respective IC50 values of 10.22 ± 0.64 and 20.89 ± 1.25 μg/mL. The extract exhibited a notable hepatoprotective effect in rats who experienced paracetamol-induced hepatotoxicity. When a dose of 250 mg/kg was given, there was a 52% reduction in alanine transaminase and a 30% reduction in aspartate transaminase compared to the group with the disease. Furthermore, it demonstrated a 3.4-fold, 2.2-fold, and 2.6-fold increase in superoxide dismutase, non-protein sulfhydryl, and glutathione peroxidase, respectively. In addition, it demonstrated a 68% decrease in lipid peroxide levels compared to the group with paracetamol-induced condition. The verification was conducted using a histological study, which identified improved liver histology with a small number of distended hepatocytes. Moreover, in silico studies focused on the enzymes NADPH oxidase, butyrylcholinesterase, and tyrosinase as the targets for the major compounds. In conclusion, MSLE showed promising hepatoprotective and antioxidant activities due to its richness in antioxidant metabolites. [ABSTRACT FROM AUTHOR]

Cold atmospheric plasma (CAP) is a promising complement to tissue repair and regenerative medicine approaches. CAP has therapeutic potential in infected cutaneous wounds by mechanisms which remain enigmatic. Here, CAP is shown to activate phagocyte NADPH oxidase complex NOX2. CAP induced increased intracellular reactive oxygen species, alleviated by NOX2 inhibitors. Genetic and pharmacological inhibitions of NOX2 in macrophages and bioengineered skin infected with Staphylococcus aureus and treated with CAP reduced intracellular oxidants and increased bacterial survival. CAP triggered Rac activation and phosphorylation of p40phox and p47phox required for NOX2 assembly and activity. Furthermore, CAP induced collagen I expression by fibroblasts. Infection and healing kinetics showed that murine skin wounds infected with S. aureus and treated with CAP are characterized by decreased bacterial burden, increased length of neoepidermis and extracellular matrix formation. Collectively, our findings identify mechanisms triggered by CAP that subdue infection and result in enhanced repair following skin injury. [ABSTRACT FROM AUTHOR]

Diabetic bladder dysfunction (DBD) is the most prevalent complication of diabetes mellitus (DM), affecting >50% of all patients. Currently, no specific treatment is available for this condition. In the early stages of DBD, patients typically complain of frequent urination and often have difficulty sensing when their bladders are full. Over time, bladder function deteriorates to a decompensated state in which incontinence develops. Based on studies of diabetic changes in the eye, kidney, heart, and nerves, it is now recognized that DM causes tissue damage by altering redox signaling in target organs. NADPH oxidase (NOX), whose sole function is the production of reactive oxygen species (ROS), plays a pivotal role in other well-known and bothersome diabetic complications. However, there is a substantial gap in understanding how NOX controls bladder function in health and the impact of NOX on DBD. The current review provides a thorough overview of the various NOX isoforms and their roles in bladder function and discusses the importance of further investigating the role of NOXs as a key contributor to DBD pathogenesis, either as a trigger and/or an effector and potentially as a target. [ABSTRACT FROM AUTHOR]

NADPH oxidases (NOXs) have been described as critical players in vascular remodeling, a mechanism modulated by matrix metalloproteinases. In this study, we describe for the first time the upregulation of MMP-10 through the activation of NOX5 in endothelial cells. In a chronic NOX5 overexpression model in human endothelial cells, MMP-10 production was measured at different levels: extracellular secretion, gene expression (mRNA and protein levels), and promoter activity. Effects on cell migration were quantified using wound healing assays. NOX5 overexpression increased MMP-10 production, favoring cell migration. In fact, NOX5 and MMP-10 silencing prevented this promigratory effect. We showed that NOX5-mediated MMP-10 upregulation involves the redox-sensitive JNK/AP-1 signaling pathway. All these NOX5-dependent effects were enhanced by angiotensin II (Ang II). Interestingly, MMP-10 protein levels were found to be increased in the hearts of NOX5-expressing mice. In conclusion, we described that NOX5-generated ROS may modulate the MMP-10 expression in endothelial cells, which leads to endothelial cell migration and may play a key role in vascular remodeling. [ABSTRACT FROM AUTHOR]

Aim: The primary endothelial NADPH oxidase isoform 4 (NOX4) is notably induced during hypoxia, with emerging evidence suggesting its vasoprotective role through H2O2 production. Therefore, we aimed to elucidate NOX4′s significance in endothelial function under hypoxia. Methods: Human vessels, in addition to murine vessels from Nox4−/− mice, were explored. On a functional level, Mulvany myograph experiments were performed. To obtain mechanistical insights, human endothelial cells were cultured under hypoxia with inhibitors of hypoxia-inducible factors. Additionally, endothelial cells were cultured under combined hypoxia and laminar shear stress conditions. Results: In human occluded vessels, NOX4 expression strongly correlated with prostaglandin I2 synthase (PTGIS). Hypoxia significantly elevated NOX4 and PTGIS expression and activity in human endothelial cells. Inhibition of prolyl hydroxylase domain (PHD) enzymes, which stabilize hypoxia-inducible factors (HIFs), increased NOX4 and PTGIS expression even under normoxic conditions. NOX4 mRNA expression was reduced by HIF1a inhibition, while PTGIS mRNA expression was only affected by the inhibition of HIF2a under hypoxia. Endothelial function assessments revealed hypoxia-induced endothelial dysfunction in mesenteric arteries from wild-type mice. Mesenteric arteries from Nox4−/− mice exhibited an altered endothelial function under hypoxia, most prominent in the presence of cyclooxygenase inhibitor diclofenac to exclude the impact of prostacyclin. Restored protective laminar shear stress, as it might occur after thrombolysis, angioplasty, or stenting, attenuated the hypoxic response in endothelial cells, reducing HIF1a expression and its target NOX4 while enhancing eNOS expression. Conclusions: Hypoxia strongly induces NOX4 and PTGIS, with a close correlation between both factors in occluded, hypoxic human vessels. This relationship ensured endothelium-dependent vasodilation under hypoxic conditions. Protective laminar blood flow restores eNOS expression and mitigates the hypoxic response on NOX4 and PTGIS. [ABSTRACT FROM AUTHOR]

The article discusses a novel hypomorphic variant in the CYBB gene that causes chronic granulomatous disease (CGD) with incomplete penetrance. CGD is a rare genetic disorder that leads to recurrent infections and inflammatory complications. The variant identified in this study results in reduced NADPH oxidase activity, affecting patients differently, with some showing severe symptoms while others remain asymptomatic. The findings highlight the importance of considering both immunological assays and clinical symptoms for appropriate therapeutic decisions in CGD patients. [Extracted from the article]

The membrane‐integrated NADPH oxidases DUOX1 and DUOX2 are recruited to the apical plasma membrane in epithelial cells to release hydrogen peroxide, thereby playing crucial roles in various functions such as thyroid hormone synthesis and host defense. However, it has remained unknown about the molecular mechanism for apical sorting of DUOX1 and DUOX2. Here we show that DUOX1 and DUOX2 are correctly sorted to the apical membrane via the membrane‐spanning DUOX maturation proteins DUOXA1 and DUOXA2, respectively, when co‐expressed in MDCK epithelial cells. Impairment of N‐glycosylation of DUOXA1 results in mistargeting of DUOX1 to the basolateral membrane. Similar to DUOX1 complexed with the glycosylation‐defective DUOXA1, the naturally non‐glycosylated oxidase NOX5, which forms a homo‐oligomer, is targeted basolaterally. On the other hand, a mutant DUOXA2 deficient in N‐glycosylation is less stable than the wild‐type protein but still capable of recruiting DUOX2 to the apical membrane, whereas DUOX2 is missorted to the basolateral membrane when paired with DUOXA1. These findings indicate that DUOXA2 is crucial but its N‐glycosylation is dispensable for DUOX2 apical recruitment; instead, its C‐terminal region seems to be involved. Thus, apical sorting of DUOX1 and DUOX2 is likely regulated in a distinct manner by their respective partners DUOXA1 and DUOXA2. [ABSTRACT FROM AUTHOR]

Black spot caused by Alternaria alternata is one of the most common postharvest diseases in fruit and vegetables. A comprehensive investigation into its pathogenicity mechanism is imperative in order to propose a targeted and effective control strategy. The effect of nitric oxide (NO) on the pathogenicity of A. alternata and its underlying mechanism was studied. The results showed that treatment with 0.5 mM L−1 of sodium nitroprusside (SNP) (NO donor) increased the lesion diameter of A. alternata in vivo and in vitro, which was 22.8% and 13.2% higher than that of the control, respectively. Exogenous NO treatment also induced endogenous NO accumulation by activating nitric oxide synthase (NOS). In addition, NO triggered an increase in reactive oxygen species (ROS) levels. NO enhanced activities and gene expression levels of NADPH oxidase (NOX), superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione peroxidase (GPX), and glutathione reductase (GR). Moreover, NO stimulated cell wall degrading enzymes by activating the corresponding gene expression in vivo and in vitro. These results suggested that exogenous NO promoted the pathogenicity of A. alternata by inducing ROS accumulation and activating antioxidants and cell wall degrading enzymes. The present results could establish a theoretical foundation for the targeted control of the black spot disease in pear fruit. [ABSTRACT FROM AUTHOR]

Obesity is associated with excess lipid deposition in nonadipose tissues, leading to increased oxidative stress and insulin resistance. Very low-density lipoprotein receptor (VLDLR), a member of the LDL receptor family, binds and increases the catabolism of triglyceride-rich lipoproteins. Although VLDLR is highly expressed in the heart, its role in obesity-associated oxidative stress and insulin resistance is unclear. Here, we used lean (wild type), genetically obese leptin-deficient (ob/ob), and leptin-VLDLR double-null (ob/ob-VLDLR−/−) mice to determine the impact of VLDLR deficiency on obesity-induced oxidative stress and insulin resistance in the heart. Although insulin sensitivity and glucose uptake were reduced in the hearts of ob/ob mice, VLDLR expression was upregulated and was associated with increased VLDL uptake and excess lipid deposition. This was accompanied by an upregulation of cardiac NADPH oxidase (Nox) expression and increased production of Nox-dependent superoxides. Silencing the VLDLR in ob/ob mice had reduced VLDL uptake and prevented excess lipid deposition in the heart, in addition to a reduction of superoxide overproduction and the normalization of insulin sensitivity and glucose uptake. In isolated cardiomyocytes, VLDLR deficiency had prevented VLDL-mediated induction of Nox activity and superoxide overproduction while improving insulin sensitivity and glucose uptake. Our findings indicate that VLDLR deficiency prevents excess lipid accumulation and moderates oxidative stress and insulin resistance in the hearts of obese mice. This effect is linked to the active role of VLDLR in VLDL uptake, which triggers a cascade of events leading to increased Nox activity, superoxide overproduction, and insulin resistance. NEW & NOTEWORTHY: Obesity is associated with excess lipid deposition in muscles, which is considered as a leading cause of metabolic dysfunction and oxidative stress. Cellular uptake of lipids is regulated by several membrane receptors, among which is the very low-density lipoprotein receptor (VLDLR). This article provides information on the role of VLDLR in cardiac muscle and how its expression regulates insulin resistance and oxidative stress in the obese mouse model. [ABSTRACT FROM AUTHOR]

The study explored proteomics to better understand the relationship between type 2 diabetes (T2DM) and hypertension (HT) in Thai adults, using shotgun proteomics and bioinformatics analysis. Plasma samples were taken from 61 subjects: 14 healthy subjects (mean age = 40.85 ± 7.12), 13 with T2DM (mean age = 57.38 ± 6.03), 16 with HT (mean age = 66.87 ± 10.09), and 18 with coexisting T2DM/HT (mean age = 58.22 ± 10.65). Proteins were identified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Protein–protein interactions were analyzed using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) version 11.5. We identified six unique proteins in T2DM patients, including translationally controlled 1 (TPT1) and nibrin (NBN), which are associated with the DNA damage response. In HT patients, seven unique proteins were identified, among them long-chain fatty acid-CoA ligase (ASCL), which functions in the stimulation of triacylglycerol and cholesterol synthesis, and NADPH oxidase activator 1 (NOXA1), which is involved in high blood pressure via angiotensin II-induced reactive oxygen species (ROS)-generating systems. In coexisting T2DM/HT patients, six unique proteins were identified, of which two—microtubule-associated protein 1A (MAP1A)—might be involved in dementia via RhoB-p53 and diacylglycerol kinase beta (DGKB), associated with lipid metabolism. This study identified new candidate proteins that are possibly involved in the pathology of these diseases. [ABSTRACT FROM AUTHOR]

Fusarium head blight (FHB), caused by Fusarium graminearum, is a devastating disease of wheat globally. However, the molecular mechanisms underlying the interactions between F. graminearum and wheat remain unclear. Here, we identified a secreted effector protein, FgEC1, that is induced during wheat infection and is required for F. graminearum virulence. FgEC1 suppressed flg22‐ and chitin‐induced callose deposition and reactive oxygen species (ROS) burst in Nicotiana benthamiana. FgEC1 directly interacts with TaGF14b, which is upregulated in wheat heads during F. graminearum infection. Overexpression of TaGF14b increases FHB resistance in wheat without compromising yield. TaGF14b interacts with NADPH oxidase respiratory burst oxidase homolog D (TaRBOHD) and protects it against degradation by the 26S proteasome. FgEC1 inhibited the interaction of TaGF14b with TaRBOHD and promoted TaRBOHD degradation, thereby reducing TaRBOHD‐mediated ROS production. Our findings reveal a novel pathogenic mechanism in which a fungal pathogen acts via an effector to reduce TaRBOHD‐mediated ROS production. [ABSTRACT FROM AUTHOR]

Babesia microti is an Apicomplexan parasite that infects erythrocytes and causes the tick-transmitted infection, babesiosis. B. microti can cause a wide variety of clinical manifestations ranging from asymptomatic to severe infection and death. Some risk factors for severe disease are well-defined, an immune compromised state, age greater than 50, and asplenia. However, increasing cases of severe disease and hospitalization in otherwise healthy individuals suggests that there are unknown risk factors. The immunopathology of babesiosis is poorly described. CD4+ T cells and the spleen both play a critical role in parasite clearance, but few other factors have been found that significantly impact the course of disease. Here, we evaluated the role of several immune mediators in B. microti infection. Mice lacking TNF receptors 1 and 2, the receptors for TNFα and LTα, had a higher peak parasitemia, reduced parasite killing in infected red blood cells (iRBCs), and delayed parasite clearance compared to control mice. Mice lacking CCR2, a chemokine receptor involved in the recruitment of inflammatory monocytes, and mice lacking NADPH oxidase, which generates superoxide radicals, demonstrated reduced parasite killing but had little effect on the course of parasitemia. These results suggest that TNFR-mediated responses play an important role in limiting parasite growth, the death of parasites in iRBCs, and the clearance of iRBCs, and that the parasite killing in iRBCs is being primarily mediated by ROS and inflammatory monocytes/macrophages. By identifying factors involved in parasite killing and clearance, we can begin to identify additional risk factors for severe infection and newer therapeutic interventions. [ABSTRACT FROM AUTHOR]

Oxidative stress has long been implicated in Parkinson's disease (PD) pathogenesis, although the sources and regulation of reactive oxygen species (ROS) production are poorly defined. Pathogenic mutations in the gene encoding leucine-rich repeat kinase 2 (LRRK2) are associated with increased kinase activity and a greater risk of PD. The substrates and downstream consequences of elevated LRRK2 kinase activity are still being elucidated, but overexpression of mutant LRRK2 has been associated with oxidative stress, and antioxidants reportedly mitigate LRRK2 toxicity. Here, using CRISPR-Cas9 gene-edited HEK293 cells, RAW264.7 macrophages, rat primary ventral midbrain cultures, and PD patient–derived lymphoblastoid cells, we found that elevated LRRK2 kinase activity was associated with increased ROS production and lipid peroxidation and that this was blocked by inhibitors of either LRRK2 kinase or NADPH oxidase 2 (NOX2). Oxidative stress induced by the pesticide rotenone was ameliorated by LRRK2 kinase inhibition and was absent in cells devoid of LRRK2. In a rat model of PD induced by rotenone, a LRRK2 kinase inhibitor prevented the lipid peroxidation and NOX2 activation normally seen in nigral dopaminergic neurons in this model. Mechanistically, LRRK2 kinase activity was shown to regulate phosphorylation of serine-345 in the p47phox subunit of NOX2. This, in turn, led to translocation of p47phox from the cytosol to the membrane-associated gp91phox (NOX2) subunit, activation of the NOX2 enzyme complex, and production of ROS. Thus, LRRK2 kinase activity may drive cellular ROS production in PD through the regulation of NOX2 activity. Editor's summary: Production of reactive oxygen species (ROS) has been implicated in Parkinson's disease (PD) pathogenesis, but the source and regulation of ROS are unclear. Overexpression of mutant leucine-rich repeat kinase 2 (LRRK2), which is known to increase PD risk, is associated with oxidative stress–induced tissue damage. Keeney and colleagues now report in several different cellular models of PD and a rat model that LRRK2 kinase activity regulates phosphorylation of serine-345 in the p47phox subunit of NADPH oxidase 2 (NOX2), leading to NOX2 activation and ROS production. These findings implicate LRRK2 kinase activity in cellular ROS production mediated by NOX2 activity. —Orla Smith [ABSTRACT FROM AUTHOR]

Background A growing number of findings have focused on the distinctive physiochemical characteristics that marine microorganisms have acquired as a result of their adaptation to the challenging conditions inherent in the marine environment. It has been established that the marine environment is a very rich source of bioactive substances with a variety of biological effects and structural diversity. A major discovery was the extraction of xyloketals from Xylaria sp. Numerous thorough studies have subsequently been carried out to determine the medicinal potential of these bioactive components. Xyloketals are thought to be a very promising and significant class of naturally occurring substances with a wide range of potent biological activities, such as radical scavenging, suppression of cell proliferation, reduction of neonatal hypoxic-ischemic brain injury, antioxidant activity, inhibition of acetylcholine esterase, inhibition of L-calcium channels, and others. Xyloketal B is one of the most potent molecules with significant therapeutic properties among the numerous variants discovered. Conclusion This review summarizes the structural characterization of all naturally occurring xyloketal compounds, especially the B derivative with an emphasis on their bioactivity and provides an outline of how xyloketals operate in diverse disease scenarios. [ABSTRACT FROM AUTHOR]

Background and Purpose: Fibromyalgia is a complex clinical disorder with an unknown aetiology, characterized by generalized pain and co‐morbid symptoms such as anxiety and depression. An imbalance of oxidants and antioxidants is proposed to play a pivotal role in the pathogenesis of fibromyalgia symptoms. However, the precise mechanisms by which oxidative stress contributes to fibromyalgia‐induced pain remain unclear. The transient receptor potential ankyrin 1 (TRPA1) channel, known as both a pain sensor and an oxidative stress sensor, has been implicated in various painful conditions. Experimental Approach: The feed‐forward mechanism that implicates reactive oxygen species (ROS) driven by TRPA1 was investigated in a reserpine‐induced fibromyalgia model in C57BL/6J mice employing pharmacological interventions and genetic approaches. Key Results: Reserpine‐treated mice developed pain‐like behaviours (mechanical/cold hypersensitivity) and early anxiety‐depressive‐like disorders, accompanied by increased levels of oxidative stress markers in the sciatic nerve tissues. These effects were not observed upon pharmacological blockade or global genetic deletion of the TRPA1 channel and macrophage depletion. Furthermore, we demonstrated that selective silencing of TRPA1 in Schwann cells reduced reserpine‐induced neuroinflammation (NADPH oxidase 1‐dependent ROS generation and macrophage increase in the sciatic nerve) and attenuated fibromyalgia‐like behaviours. Conclusion and Implications: Activated Schwann cells expressing TRPA1 promote an intracellular pathway culminating in the release of ROS and recruitment of macrophages in the mouse sciatic nerve. These cellular and molecular events sustain mechanical and cold hypersensitivity in the reserpine‐evoked fibromyalgia model. Targeting TRPA1 channels on Schwann cells could offer a novel therapeutic approach for managing fibromyalgia‐related behaviours. [ABSTRACT FROM AUTHOR]

Background and Purpose: This study analyses whether first‐line antihypertensive drugs ameliorate the dysbiosis state in hypertension, and to test if this modification contributes to their blood pressure (BP) lowering properties in a genetic model of neurogenic hypertension. Experimental Approach: Twenty‐week‐old male Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) were untreated or treated with captopril, amlodipine or hydrochlorothiazide. A faecal microbiota transplantation (FMT) experiment was also performed by gavage of faecal content from donor SHR‐treated groups to SHR recipients for 3 weeks. Key results: Faeces from SHR showed gut dysbiosis, characterized by lower acetate‐ and higher lactate‐producing bacteria and lower strict anaerobic bacteria. All three drugs increased the anaerobic bacteria proportion, captopril and amlodipine restored the proportion of acetate‐producing bacterial populations to WKY levels, whereas hydrochlorothiazide decreased butyrate‐producing bacteria. Captopril and amlodipine decreased gut pathology and permeability and attenuated sympathetic drive in the gut. Both drugs decreased neuroinflammation and oxidative stress in the hypothalamic paraventricular nuclei. Hydrochlorothiazide was unable to reduce neuroinflammation, gut sympathetic tone and gut integrity. FMT from SHR‐amlodipine to SHR decreased BP, ameliorated aortic endothelium‐dependent relaxation to acetylcholine, lowered NADPH oxidase activity, aortic Th17 infiltration and reduced neuroinflammation, whereas FMT from SHR‐hydrochlorothiazide did not have these effects. Conclusions and Implications: First‐line antihypertensive drugs induced different modifications of gut integrity and gut dysbiosis in SHR, which result in no contribution of microbiota in the BP lowering effects of hydrochlorothiazide, whereas the vasculo‐protective effect induced by amlodipine involves gut microbiota reshaping and gut‐immune system communication. [ABSTRACT FROM AUTHOR]

Myocardial stretch physiologically activates NADPH oxidase 2 (NOX2) to increase reactive oxygen species (ROS) production. Although physiological low‐level ROS are known to be important as signalling molecules, the role of stretch‐induced ROS in the intact myocardium remains unclear. To address this, we investigated the effects of stretch‐induced ROS on myocardial cellular contractility and calcium transients in C57BL/6J and NOX2−/− mice. Axial stretch was applied to the isolated cardiomyocytes using a pair of carbon fibres attached to both cell ends to evaluate stretch‐induced modulation in the time course of the contraction curve and calcium transient, as well as to evaluate maximum cellular elastance, an index of cellular contractility, which is obtained from the end‐systolic force–length relationship. In NOX2−/− mice, the peak calcium transient was not altered by stretch, as that in wild‐type mice, but the lack of stretch‐induced ROS delayed the rise of calcium transients and reduced contractility. Our mathematical modelling studies suggest that the augmented activation of ryanodine receptors by stretch‐induced ROS causes a rapid and large increase in the calcium release flux, resulting in a faster rise in the calcium transient. The slight increase in the magnitude of calcium transients is offset by a decrease in sarcoplasmic reticulum calcium content as a result of ROS‐induced calcium leakage, but the faster rise in calcium transients still maintains higher contractility. In conclusion, a physiological role of stretch‐induced ROS is to increase contractility to counteract a given preload, that is, it contributes to the Frank–Starling law of the heart. Key points: Myocardial stretch increases the production of reactive oxygen species by NADPH oxidase 2.We used NADPH oxidase 2 knockout mice to elucidate the physiological role of stretch‐induced reactive oxygen species in the heart.We showed that stretch‐induced reactive oxygen species modulate the rising phase of calcium transients and increase myocardial contractility.A mathematical model simulation study demonstrated that rapid activation of ryanodine receptors by reactive oxygen species is important for increased contractility.This response is advantageous for the myocardium, which must contract against a given preload. [ABSTRACT FROM AUTHOR]

Although previous studies have demonstrated that methane (CH4) can mitigate the toxicity of cadmium (Cd) in alfalfa seedlings, the CH4-rich water used in these studies may create hypoxic conditions, potentially influencing the experimental outcomes. Therefore, this study aimed to investigate whether CH4 can reduce Cd toxicity in alfalfa seedlings without the interference of hypoxia and to analyze its underlying mechanisms. Here, it was observed that supplementing oxygen with saturated CH4-rich water can significantly alleviate the inhibition of 75 μM CdCl2 on the growth of alfalfa (Medicago sativa L.) seedlings. Less Cd accumulation was also observed in both root and shoot parts, which could be explained by the CH4-altered cell wall components in alfalfa seedling roots, including covalent and ionic soluble pectin, and the degree of demethylation in pectin, thus enabling a higher proportion of Cd binding to the cell walls and reducing the entry of Cd into the cells. The above actions of CH4 were accompanied by an increase in hydrogen peroxide (H2O2) content and NADPH oxidase activity, which could be blocked by the addition of the NADPH oxidase inhibitor diphenylene iodonium (DPI). Taken together, these results implied that exogenously applied CH4 could alleviate Cd toxicity in alfalfa seedlings by enhancing Cd chelation onto the root cell walls, which might be closely associated with NADPH oxidase-dependent H2O2 signals. These findings could provide insight into the mechanism through which CH4 alleviates Cd toxicity in alfalfa plants. [ABSTRACT FROM AUTHOR]

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The Nox1-centered NADPH oxidase complex facilitates the transfer of electrons from intracellular NADPH across the cell membrane to extracellular molecular oxygen, resulting in the formation of superoxide. The complex is comprised of two membrane-bound subunits, namely Nox1 and p22phox, and the cytosolic subunits, namely NoxA1 and NoxO1. The presence of NoxO1 facilitates the proximity of all components, thereby enabling the complex to exhibit constitutive activity. Despite the theoretical sufficiency of all subunits in a 1:1 ratio, the precise composition of the Nox1-centered NADPH oxidase remains unknown. Analyses of mRNA expression in different cell lines revealed an unequal expression of the components, with an excess of NoxO1. Furthermore, plasmid-based overexpression of individual components of the Nox1-centered NADPH oxidase resulted in an excess of NoxO1 mRNA. The objective of this study was to analyze the ability of NoxO1 to control the level of ROS formation by the Nox1 complex. To this end, we generated Hek293 cells for constitutive expression of Nox1 and NoxA1, which were then transfected with increasing concentrations of NoxO1. The data presented herein suggests that ROS formation by the Nox1-centered NADPH oxidase is dependent on the concentration of NoxO1. A surplus of NoxO1 has been observed to exert control over the activity of the complex in accordance with a dose-dependent mechanism. We thus conclude that the ratio of Nox1, NoxA1, and NoxO1 complexes does not adhere to a 1:1 ratio. Conversely, the availability of NoxO1 serves to regulate the formation of ROS by the Nox1-centered NADPH oxidase. [ABSTRACT FROM AUTHOR]

Stroke is one of the most significant causes of death and long-term disability globally. Overproduction of reactive oxygen species by NADPH oxidase (NOX) plays an important role in exacerbating oxidative stress and causing neuronal damage after a stroke. There is growing evidence that NOX inhibition prevents ischemic injury and that the role of NOX in brain damage or recovery depends on specific post-stroke phases. In addition to studies on post-stroke neuroprotection by NOX inhibition, recent reports have also demonstrated the role of NOX in stroke recovery, a critical process for brain adaptation and functional reorganization after a stroke. Therefore, in this review, we investigated the role of NOX in stroke recovery with the aim of integrating preclinical findings into potential therapeutic strategies to improve stroke recovery. [ABSTRACT FROM AUTHOR]

Enhancing crop drought tolerance is crucial for food security amid climate change. This study examines how 5‐aminolevulinic acid (ALA) and hydrogen sulfide (H2S) can improve drought resilience in tomato plants, which are essential for sustainable food production. Drought stress was induced using 12% PEG‐6000. Plants were pre‐treated with 25 mg L−1 ALA and 0.1 mg L−1 hypotaurine (HT), followed by 0.2 mM sodium hydrosulfide (NaHS) treatment to assess the effects on plant physiological effects over 10 days. Drought stress reduced plant dry weight, chlorophylls (a and b), Fv/Fm, leaf water potential, and relative water content, while increasing glycine betaine (GB) and proline levels. Additionally, drought stress elevated NADPH oxidase (NOX) and glycolate oxidase (GOX) activities, inducing oxidative stress and membrane damage. ALA and NaHS enhanced plant growth, photosynthesis, proline, GB, ALA content, ATP synthase, and ATPase activities, while mitigating NOX and GOX activities, thereby reducing O2·−$$ {\mathrm{O}}_2^{\cdotp -} $$ and H2O2 radicals. ALA alone boosted L‐DES activity, promoting H2S accumulation. However, ALA + HT reduced H2S levels, compromising ALA's efficacy. NaHS with ALA + HT reinstated positive effects by restoring H2S levels. Biochemical assays confirmed ALA and NaHS promoted H2S accumulation, bolstering antioxidants, mitigating lipid peroxidation, suggesting their drought resilience potential in tomatoes. [ABSTRACT FROM AUTHOR]

The stress-protective effect of melatonin (N-acetyl-5-methoxytryptamine) on plant cells is mediated by key signaling mediators, in particular calcium ions and reactive oxygen species (ROS). However, the links between changes in calcium and redox homeostasis and the formation of adaptive responses of cultivated cereals (including wheat) to the action of high temperatures have not yet been studied. In the present study, we investigated the possible involvement of ROS and calcium ions as signaling mediators in developing heat resistance in wheat (Triticum aestivum L.) seedlings and activating their antioxidant system. Treatment of 3-day-old etiolated seedlings with melatonin solutions at concentrations 0.01–10 µM increased their survival after exposure to 45 °C for 10 min. The most significant stress-protective effect was exerted by melatonin treatment at 1 µM concentration. Under the influence of melatonin, a transient enhancement of superoxide anion radical (O2•–) generation and an increase in hydrogen peroxide content were observed in roots, with a maximum at 1 h. Four hours after treatment with melatonin, the activity of catalase and guaiacol peroxidase increased in roots, while the activity of superoxide dismutase did not change significantly. After exposure to 45 °C, the activity of catalase and guaiacol peroxidase was higher in the roots of melatonin-treated wheat seedlings, and the indices of ROS generation, content of the lipid peroxidation product malonic dialdehyde, and cell membrane damage were lower than in control seedlings. Melatonin-induced changes in root ROS generation and antioxidant enzyme activities were eliminated by pretreatment with the hydrogen peroxide scavenger dimethylthiourea (DMTU), NADPH oxidase inhibitor imidazole, and calcium antagonists (the extracellular calcium chelator EGTA and phospholipase C inhibitor neomycin). Treatment with DMTU, imidazole, EGTA, and neomycin also abolished the melatonin-induced increase in survival of wheat seedlings after heat stress. The role of calcium ions and ROS, generated with the participation of NADPH oxidase, as signaling mediators in the melatonin-induced antioxidant system and heat stress resistance of wheat seedlings have been demonstrated. [ABSTRACT FROM AUTHOR]

Recent evidence indicates that the damaged regions in osteoarthritis are accompanied by the accumulation of iron ions. Ferroptosis, as an iron‐dependent form of cell death, holds significant implications in osteoarthritis. Melatonin, a natural product with strong scavenging abilities against reactive oxygen species and lipid peroxidation, plays a crucial role in the treatment of osteoarthritis. This study aims to demonstrate the existence of ferroptosis in osteoarthritis and explore the specific mechanism of melatonin in suppressing ferroptosis and alleviating osteoarthritis. Our findings reveal that melatonin reverses inflammation‐induced oxidative stress and lipid peroxidation while promoting the expression of extracellular matrix components in chondrocytes, safeguarding the cells. Our research has revealed that NADPH oxidase 4 (NOX4) serves as a crucial molecule in the ferroptosis process of osteoarthritis. Specifically, NOX4 is located on mitochondria in chondrocytes, which can induce disorders in mitochondrial energy metabolism and dysfunction, thereby intensifying oxidative stress and lipid peroxidation. LC‐MS analysis further uncovered that GRP78 is a downstream binding protein of NOX4. NOX4 induces ferroptosis by weakening GRP78's protective effect on GPX4 and reducing its expression. Melatonin can inhibit the upregulation of NOX4 on mitochondria and mitigate mitochondrial dysfunction, effectively suppressing ferroptosis and alleviating osteoarthritis. This suggests that melatonin therapy represents a promising new approach for the treatment of osteoarthritis. [ABSTRACT FROM AUTHOR]

Objective: This study aims to investigate the effect of NADPH oxidase 4 (NOX4)-mediated inflammation on concanavalin A (ConA)-induced dry eye syndrome (DES) in mice. Methods: Thirty-six mice were randomly divided into Control, Model, no-load Control, and NOX4 interference group. Adenovirus was injected (10 μL) into the lacrimal glands of both eyes of mice in no-load Control group and NOX4 interference group. Four days after adenovirus injection, the Control group was injected with phosphate-buffered saline, and the other groups were injected with ConA (200 μg) in the lacrimal glands of mice to establish DES models. The tear secretion rate was estimated by phenol red thread test. Lissamine green eye staining was used to evaluate conjunctival damage. The corneal surface was observed by hematoxylin–eosin (HE) staining and scanning electron microscopy (SEM). The morphology and quantity of conjunctival epithelial cells and goblet cells were observed by Periodic acid-Schiff staining. The expression of NOX4, NOD-like receptor thermal protein domain-associated protein 3 (NLRP3), interleukin-1β (IL-1β), and mucin 5 subtype AC (MUC5AC) was detected by immunohistochemistry. Results: Compared with the Control group, the Model group showed a significant decrease in tear secretion and an upregulation in microscopic image score. The HE staining and SEM showed corneal and conjunctiva damage in the Model group. The protein expression of NOX4, NLRP3, and IL-1β was upregulated, but MUC5AC was downregulated in the Model group. After interfering with NOX4, all these indicators were reversed. Conclusion: The pathological process of concanavalin A-induced DES appears to be related to NOX4. [ABSTRACT FROM AUTHOR]

Background: In the realm of wheat seed germination, abiotic stresses such as salinity and high temperature have been shown to hinder the process. These stresses can lead to the production of reactive oxygen species, which, within a certain concentration range, may actually facilitate seed germination. γ-aminobutyric acid (GABA), a non-protein amino acid, serves as a crucial signaling molecule in the promotion of seed germination. Nevertheless, the potential of GABA to regulate seed germination under the simultaneous stress of heat and salinity remains unexplored in current literature. Methods: This study employed observational methods to assess seed germination rate (GR), physiological methods to measure H2O2 content, and the activities of glutamate decarboxylase (GAD), NADPH oxidase (NOX), superoxide dismutase (SOD), and catalase (CAT). The levels of ABA and GABA were quantified using high-performance liquid chromatography technology. Furthermore, quantitative real-time PCR technology was utilized to analyze the expression levels of two genes encoding antioxidant enzymes, MnSOD and CAT. Results: The findings indicated that combined stress (30 °C + 50 mM NaCl) decreased the GR of wheat seeds to about 21%, while treatment with 2 mM GABA increased the GR to about 48%. However, the stimulatory effect of GABA was mitigated by the presence of ABA, dimethylthiourea, and NOX inhibitor, but was strengthened by H2O2, antioxidant enzyme inhibitor, fluridone, and gibberellin. In comparison to the control group (20 °C + 0 mM NaCl), this combined stress led to elevated levels of ABA, reduced GAD and NOX activity, and a decrease in H2O2 and GABA content. Further investigation revealed that this combined stress significantly suppressed the activity of superoxide dismutase (SOD) and catalase (CAT), as well as downregulated the gene expression levels of MnSOD and CAT. However, the study demonstrates that exogenous GABA effectively reversed the inhibitory effects of combined stress on wheat seed germination. These findings suggest that GABA-induced NOX-mediated H2O2 signalling plays a crucial role in mitigating the adverse impact of combined stress on wheat seed germination. This research holds significant theoretical and practical implications for the regulation of crop seed germination by GABA under conditions of combined stress. [ABSTRACT FROM AUTHOR]

Rationale: Nitric oxide (NO) is increased in the airways and serum of patients with allergic asthma, suggesting an important role in asthma. NO production has been widely attributed to the canonical inducible NO synthase. Much effort has been made to inhibit this enzyme, with two outcomes: no asthma improvement and partial NO reduction, suggesting the involvement of an inducible NO synthase–independent source. Objectives: Neutrophils produce NO under inflammatory conditions, and their role in asthma has been overlooked. The present study analyzes their possible role as sources of NO. Methods: Our hypothesis was tested in 99 allergic patients with intermittent bronchial asthma and 26 healthy donors. NO production by blood and sputum neutrophils in response to allergens, anti-IgE, and anti-IgE receptor antibodies was assessed by Griess reagent, flow cytometry, and confocal microscopy. The formation of extracellular traps (ETs) as a possible consequence of NO production was quantified by Western blot and confocal microscopy, and reactive oxygen species were assessed with luminol-enhanced chemiluminescence. Measurements and Main Results: Among blood and sputum granulocytes from patients with allergic asthma, only neutrophils produce NO by an IgE-dependent mechanism. This production is independent of NO synthase, but dependent on a reaction between L-arginine and reactive oxygen species from NOX2 (NADPH oxidase). NO and ETosis are induced in parallel, and NO amplifies ET formation, which is a key mediator in asthma. Conclusions: Our findings reveal a novel role of neutrophils as the unique allergen/IgE–dependent NO source in allergic asthma, enhancing ET formation. These results suggest that NO produced by neutrophils needs further consideration in the treatment of allergic asthma. [ABSTRACT FROM AUTHOR]

Cellular metabolism is a key determinant of immune cell function. Here we found that CD14+ monocytes from Sub‐Saharan Africans produce higher levels of IL‐10 following TLR‐4 stimulation and are bioenergetically distinct from monocytes from Europeans. Through metabolomic profiling, we identified the higher IL‐10 production to be driven by increased baseline production of NADPH oxidase‐dependent reactive oxygen species, supported by enhanced pentose phosphate pathway activity. Together, these data indicate that NADPH oxidase‐derived ROS is a metabolic checkpoint in monocytes that governs their inflammatory profile and uncovers a metabolic basis for immunological differences across geographically distinct populations. [ABSTRACT FROM AUTHOR]

Chemerin is an adipokine that contributes to metabolism regulation. Nucleus tractus solitarius (NTS) is the first relay station in the brain for accepting various visceral afferent activities for regulating cardiovascular activity. However, the roles of chemerin in the NTS in regulating sympathetic activity and blood pressure are almost unknown. This study aimed to determine the role and potential mechanism of chemerin in the NTS in modulating sympathetic outflow and blood pressure. Bilateral NTS microinjections were performed in anaesthetized adult male Sprague–Dawley rats. Renal sympathetic nerve activity (RSNA), mean arterial pressure (MAP) and heart rate (HR) were continuously recorded. Chemerin and its receptor chemokine‐like receptor 1 (CMKLR1) were highly expressed in caudal NTS (cNTS). Microinjection of chemerin‐9 to the cNTS increased RSNA, MAP and HR, which were prevented by CMKLR1 antagonist α‐NETA, superoxide scavenger tempol or N‐acetyl cysteine, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitors diphenyleneiodonium or apocynin. Chemerin‐9 increased superoxide production and NADPH oxidase activity in the cNTS. The increased superoxide production induced by chemerin‐9 was inhibited by α‐NETA. The effects of cNTS microinjection of chemerin‐9 on the RSNA, MAP and HR were attenuated by the pretreatment with paraventricular nucleus (PVN) microinjection of NMDA receptor antagonist MK‐801 rather than AMPA/kainate receptor antagonist CNQX. These results indicate that chemerin‐9 in the NTS increases sympathetic outflow, blood pressure and HR via CMKLR1‐mediated NADPH oxidase activation and subsequent superoxide production in anaesthetized normotensive rats. Glutamatergic inputs in the PVN are needed for the chemerin‐9‐induced responses. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) is one of the key signaling factors regulating skeletal muscle adaptation to muscle contractions. Eccentric (ECC) and concentric (CONC) contractions drive different muscle adaptations with ECC resulting in greater changes. The present investigation tested the hypothesis that ECC produces higher cytosolic and mitochondrial H2O2 concentrations [H2O2] and alters gene expression more than CONC. Cytosolic and mitochondrial H2O2-sensitive fluorescent proteins, HyPer7 and MLS-HyPer7, were expressed in the anterior tibialis muscle of C57BL6J male mice. Before and for 60 min after either CONC or ECC (100 Hz, 50 contractions), [H2O2]cyto and [H2O2]mito were measured by in vivo fluorescence microscopy. RNA sequencing was performed in control (noncontracted), CONC, and ECC muscles to identify genes impacted by the contractions. [H2O2]cyto immediately after ECC was greater than after CONC (CONC: +6%, ECC: +11% vs. rest, P < 0.05) and remained higher for at least 60 min into recovery. In contrast, the elevation of [H2O2]mito was independent of the contraction modes (time; P < 0.0042, contraction mode; P = 0.4965). The impact of ECC on [H2O2]cyto was abolished by NADPH oxidase 2 (Nox2) inhibition (GSK2795039). Differentially expressed genes were not present after CONC or ECC + GSK but were found after ECC and were enriched for vascular development and apoptosis-related genes, among others. In conclusion, in mouse anterior tibialis, ECC, but not CONC, evokes a pronounced cytosolic H2O2 response, caused by Nox2, that is mechanistically linked to gene expression modifications. NEW & NOTEWORTHY: This in vivo model successfully characterized the effects of eccentric (ECC) and concentric (CONC) contractions on cytosolic and mitochondrial [H2O2] in mouse skeletal muscle. Compared with CONC, ECC induced higher and more sustained [H2O2]cyto—an effect that was abolished by Nox2 inhibition. ECC-induced [H2O2]cyto elevations were requisite for altered gene expression. [ABSTRACT FROM AUTHOR]

Oxidative stress constitutes a main molecular mechanism underlying cardiovascular diseases (CVDs). This pathological mechanism can be triggered by NADPH oxidases (NOXs), which produce reactive oxygen species (ROS). In fact, the different NOXs have been associated with myocardial infarction, atherothrombosis, and stroke. More specifically, we will focus on the implications of NOXs in atherothrombotic stroke. Each NOX member participates in a different way in the several stages of this disease: endothelial dysfunction, immune cell infiltration, foam cell genesis, vascular smooth muscle cells (VSMC) proliferation, and atherosclerotic plaque formation. Additionally, some NOXs are involved in plaque instability, thrombosis, ischemic stroke, and ischemia-reperfusion injury (IRI). Interestingly, the effects of NOXs in this pathology depend on the specific homolog, the cell type in which they are activated, and the stage of the disease. In this review we summarize the most up-to-date information about the implications of vascular NOXs in each of these processes. Finally, we highlight some limitations and future perspectives on the study of NOXs in CVDs. [ABSTRACT FROM AUTHOR]