Search Results (208)

We investigated the role of the intermediate-conductance, Ca²⁺-activated K⁺ channel K_Ca3.1 and volume-regulatory anion channel LRRC8A in regulating C-C motif chemokine ligand 2 (CCL2) expression in THP-1-differentiated M₂ macrophages (M₂-MACs), which serve as a useful model for studying tumor-associated macrophages (TAMs). CCL2 is a potent chemoattractant involved in the recruitment of immunosuppressive cells and its expression is regulated through intracellular signaling pathways such as ERK, JNK, and Nrf2 in various types of cells including macrophages. The transcriptional expression of CCL2 was suppressed in M₂-MACs following treatment with a K_Ca3.1 activator or an LRRC8A inhibitor via distinct signaling pathways: ERK–CREB2 and JNK–c-Jun pathways for K_Ca3.1, and the NOX2–Nrf2–CEBPB pathway for LRRC8A. Under in vitro conditions mimicking the elevated extracellular K⁺ concentration ([K⁺]_e) characteristic of the tumor microenvironment (TME), CCL2 expression was markedly upregulated, and this increase was reversed by treatment with them in M₂-MACs. Additionally, the WNK1–AMPK pathway was, at least in part, involved in the high [K⁺]_e-induced upregulation of CCL2. Collectively, modulating K_Ca3.1 and LRRC8A activities offers a promising strategy to suppress CCL2 secretion in TAMs, potentially limiting the CCL2-induced infiltration of immunosuppressive cells (TAMs, T_regs, and MDSCs) in the TME. Full article

Although platelets have been traditionally thought of to be essential hemostasis mediators, new research shows how important they are for controlling cellular oxidative stress, inflammatory processes, and immunological responses—particularly during major surgery on the abdomen. Perioperative problems are largely caused by the continually changing interaction of inflammatory cytokines, the formation of reactive oxygen species (ROS), and platelet activation. The purpose of this review is to summarize the most recent data regarding the complex function of platelets in abdominal surgery, with an emphasis on how they interact with inflammation and oxidative stress, and to investigate the impact on postoperative therapy and subsequent studies. Recent study data on platelet biology, redox signals, surgical stress, and antiplatelet tactics was reviewed in a systematic manner. Novel tailored therapies, perioperative antiplatelet medication, oxidative biomarkers of interest, and platelet-derived microscopic particles are important themes. In surgical procedures, oxidative stress dramatically increases the reactive capacity of platelets, spurring thromboinflammatory processes that affect cardiac attacks, infection risk, and recovery. A number of biomarkers, including soluble CD40L, thromboxane B2, and sNOX2-derived peptide, showed potential in forecasting results and tailored treatment. Antiplatelet medications are still essential for controlling risk factors for cardiovascular disease, yet using them during surgery necessitates carefully weighing the risks of thrombosis and bleeding. Biomarker-guided therapies, antioxidant adjuncts, and specific platelet inhibitors are examples of evolving tactics. In abdominal procedures, platelets strategically operate at the nexus of oxidative stress, inflammatory processes, and clotting. Improved patient classification, fewer problems, and the creation of individualized surgical care strategies could result from an increased incorporation of platelet-focused tests and therapies into perioperative processes. To improve clinical recommendations, subsequent studies may want to focus on randomized studies, biomarker verification, and using translational approaches. Full article

Alzheimer’s disease (AD) is associated with an abnormal accumulation of amyloid β (Aβ) fibrils in the brain parenchyma and cerebrovasculature, which leads to cognitive impairment and cerebrovascular dysfunction. Cerebrovascular endothelial cells play a crucial role in regulating cerebral blood flow, vascular permeability, and neurovascular function. Reactive oxygen species (ROS), particularly those generated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2), contribute to vascular dysfunction and amyloid deposition in the Alzheimer’s disease (AD) brain. However, the role of the NOX4 isoform in AD pathogenesis remains to be examined. In the present study, we found that NOX4 among the NOX isoforms is predominantly expressed in bEnd.3 mouse brain endothelial cells. Treatment with Aβ₄₀ significantly enhanced the release of H₂O₂ and NO, and increased the endothelial cell viability. To test the involvement of NOX4 in Aβ₄₀-induced H₂O₂ production, we utilized pharmacological inhibitors of NOX isoforms. Aβ₄₀-induced H₂O₂ production was attenuated in the presence of the pan-NOX inhibitor, apocynin, or the NOX1/4-selective inhibitors, setanaxib and GKT136901. Since only the NOX4 isoform is expressed in bEnd.3 cells, these results indicate that NOX4 is responsible for the release of H₂O₂ stimulated by Aβ₄₀. Taken together, the present study demonstrated that Aβ₄₀ peptide exerts beneficial effects in bEnd.3 endothelial cells via the NOX4-dependent mechanism. Full article

Reactive nitrogen species (RNS), particularly peroxynitrite (ONOO⁻), play a central role in post-translational modifications (PTMs) of proteins, including fibrinogen, a key component of the coagulation cascade. This review explores the structural and functional consequences of fibrinogen nitration, with a focus on its impact on clot formation, morphology, mechanical stability, and fibrinolysis. Nitration, primarily targeting tyrosine residues within functional domains of the Aα, Bβ, and γ chains, induces conformational changes, dityrosine crosslinking, and aggregation into high molecular weight species. These modifications result in altered fibrin polymerization, the formation of porous and disorganized clot networks, reduced mechanical resilience, and variable susceptibility to fibrinolysis. Moreover, nitrated fibrinogen may affect interactions with platelets and endothelial cells, although current evidence remains limited. Emerging clinical studies support its role as both a prothrombotic mediator and a potential biomarker of oxidative stress in cardiovascular and inflammatory diseases. Finally, we explore both pharmacological interventions, such as NOX inhibitors, and natural antioxidant strategies at counteracting fibrinogen nitration. Overall, fibrinogen nitration emerges as a critical molecular event linking oxidative stress to thrombotic risk. Full article

CD38, a nicotinamide adenine dinucleotide (NAD⁺) glycohydrolase, increases in old murine macrophages after infection compared to young controls. We aimed to determine whether the increase in CD38 in old murine macrophages after infection is directly associated with enhanced inflammation induced by the oral pathogens Aggregatibacter actinomycetemcomitans (Aa) or Porphyromonas gingivalis (Pg) when compared to young controls. Additionally, we determined the effects of a specific CD38 inhibitor (78c) on CD38, NAD⁺, interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α expressions, and anti-oxidative responses in old murine macrophages induced by oral pathogens. Old and young murine macrophages were either uninfected or infected with the oral pathogens Aa or Pg for 1 to 24 h. Protein levels of CD38 and protein kinases, including nuclear factor kappa-B (NF-κB), phosphoinositide 3-kinase (PI3K), and mitogen-activated protein kinases (MAPKs), NAD⁺, and inflammatory cytokine (IL-1β, IL-6, TNF-α) levels were evaluated. Additionally, old murine macrophages were treated with a vehicle or a CD38 inhibitor (78c) and cells were either uninfected or infected with Aa or Pg. CD38, NAD⁺, cytokine (IL-1β, IL-6, TNF-α) levels, reactive oxygen species (ROS), NAPDH oxidase 1 (Nox1), and anti-oxidative enzymes, including superoxide dismutase1 (Sod1), glutathione peroxidase 4 (Gpx4), Peroxiredoxin 1 (Prdx1), thioredoxin reductase 1 (Txnrd1), and catalase (Cat), were evaluated. The results showed that old murine macrophages significantly enhanced CD38 and reduced NAD⁺ levels 24 h after Aa or Pg infection compared to young controls. This enhanced CD38 in old murine macrophages was not directly correlated with the activation of protein kinases (NF-κB, PI3K, and MAPKs), nor the (IL-1β, IL-6, TNF-α) levels in macrophages. The inhibition of CD38 by 78c reduced CD38, enhanced NAD⁺ levels, attenuated IL-1β, IL-6 and TNF-α pro-inflammatory cytokine levels, reduced ROS and Nox1 expressions, and enhanced expressions of Sod1, Gpx4, Prdx1, Txnrd1, and Cat in old murine macrophages infected with Aa or Pg. These results suggest that the inhibition of CD38 by 78c is a promising therapeutic strategy to treat aging-associated periodontitis. Full article

Diabetic muscular atrophy is a complication of diabetes mellitus that can decrease quality of life. Its complex mechanisms include alterations in proteolytic pathways, oxidative stress, and intracellular lipid accumulation. NADPH oxidase enzymes (NOX) play a key role in the production of ROS, contributing to oxidative damage and insulin resistance. Apocynin, a NOX inhibitor, has antioxidant and anti-inflammatory effects, suggesting its therapeutic potential in various diabetic complications. This study evaluated the impact of apocynin on the mechanisms of muscle atrophy in slow- and fast-twitch muscles of diabetic rats. Diabetes was induced in male Wistar rats by intraperitoneal injection of a single dose of streptozotocin (60 mg/kg). Apocynin treatment (3 mg/kg/day) was administered for 8 weeks. Fasting blood glucose levels, lipid profile, and weight gain were measured. Both slow-twitch (soleus) and fast-twitch (extensor digitorum longus, EDL) skeletal muscles were weighed and used to assess triglycerides (TG) content, histological analysis, lipid peroxidation levels, and gene expression evaluated by qRT-PCR. Apocynin reduced blood glucose levels, improved body weight, and exhibited hypolipidemic effects. It significantly increased muscle weight in EDL and soleus, especially in EDL muscle, lowering triglycerides, lipid peroxidation, and increasing fiber size. Additionally, it decreased mRNA expression levels of MuRF-1, atrogin-1, myostatin and p47phox mRNA and upregulated PGC-1α and follistatin mRNA. Apocynin exerted a myoprotective effect by mitigating muscle atrophy in diabetic rats. Its effects were differentially mediated on TG accumulation and muscle fiber size, reducing oxidative stress, atrogene expression, and positively regulating PGC-1α. Full article

Neutrophil extracellular trap (NET) formation is a process known as NETosis and is a critical innate immune response mechanism that can become pathologically dysregulated in various inflammatory, autoimmune, infectious, and neoplastic diseases. Reactive oxygen species (ROS) play a central role in NETosis induction, making antioxidants a promising therapeutic approach. This review outlines the molecular mechanisms underlying NET formation and highlights three principal antioxidant-based inhibitory strategies: NADPH oxidase (NOX) inhibition, ROS scavenging, and myeloperoxidase (MPO) inhibition. Evidence supports the use of agents such as diphenylene iodonium (NOX inhibitor), N-acetylcysteine and glutathione (ROS scavengers), and thiocyanate (MPO inhibitor), which significantly reduce NETosis in vitro and in vivo. Moreover, natural compounds like resveratrol show pleiotropic effects by modulating neutrophil activation, ROS production, and protease activity. Combination therapies that enhance total antioxidant capacity are particularly effective, though their translation to clinical practice faces challenges such as stimulus specificity, bioavailability, and maintaining immune competence. Antioxidant-based therapies thus represent a promising avenue for targeted NETosis modulation. Future research should focus on improving delivery systems, identifying NET-specific biomarkers, and integrating antioxidants into broader immunomodulatory strategies. Full article

Androgenetic alopecia is associated with testosterone-mediated anagen-to-catagen transition and matrix keratinocyte apoptosis in hair follicle cells. Activation of Nox isozymes is involved in testosterone-mediated keratinocyte apoptosis, leading to androgenetic alopecia. This indicates that Nox isozymes can serve as therapeutic targets for androgenetic alopecia. The isolated compounds from natural products were screened to evaluate their ROS-inhibition efficacy and it was found that 1′S-1′-acetoxychavicol acetate (ACA, 26), a natural compound isolated from Alpinia galanga (L.) Willd. (Zingiberaceae), exhibits inhibitory activity on Nox isozymes. Nox inhibition by ACA suppressed testosterone-dependent H₂O₂ generation and cell death in keratinocytes. Incubation with ACA in human hair follicle organ culture mitigated testosterone-dependent suppression of hair growth. We validated that ACA regulates androgenetic alopecia in a mouse model. Local application of ACA on the dorsal skin in an androgenetic alopecia model of C57BL/6 mice significantly suppressed testosterone-induced hair loss in a dose-dependent manner. Moreover, hair follicle length in ACA-treated mice was enhanced compared to that in control mice. These findings provide a molecular mechanism in which ACA inhibits Nox activity in hair follicle cells, indicating its potential as an effective treatment of AGA. Full article

Background/Objectives: Strawberries are highly appreciated for their rich phytochemical composition, but rapid postharvest deterioration limits their shelf life and nutritional quality. This study aimed to investigate the metabolic changes occurring in both strawberry fruits and leaves during storage and to evaluate the NADPH oxidase 2 (NOX2) inhibitory potential of strawberry-derived metabolites. Methods: Untargeted LC-MS/MS analysis was conducted on fruit and leaf tissues stored at 8 ± 0.5 °C. A total of 37 metabolites were identified, including organic acids, phenolic acids, flavonoids, and hydroxycinnamic acid derivatives. Multivariate statistical analyses (ANOVA, PLS-DA, and volcano plots) were used to assess temporal and tissue-specific metabolic shifts. Additionally, a machine learning-based predictive model was applied to evaluate the NOX2 inhibitory potential of 24 structurally characterized metabolites. Results: Storage induced significant and tissue-specific metabolic changes. In fruits, malic acid, caffeic acid, and quercetin-3-glucuronide showed notable variations, while ellagic acid aglycone and galloylquinic acid emerged as prominent markers in leaves. The predictive model identified 21 out of 24 metabolites as likely NOX2 inhibitors, suggesting potential antioxidant and anti-inflammatory bioactivity. Conclusions: These findings provide new insights into postharvest biochemical dynamics in both strawberry fruits and leaves. The results highlight the value of leaves as a source of bioactive compounds and support their potential valorization in functional food and nutraceutical applications. Full article

(1) Background: Silicosis, a chronic lung fibrosis disorder triggered by the accumulation of silica dust in the deep lung regions, is characterized by intricate molecular mechanisms. Among these, the NOX2 (NADPH oxidase 2) and JNK (C-Jun N-terminal kinase) signaling pathways play pivotal roles in the progression of pulmonary fibrosis. Despite their significance, the precise mechanisms underlying the crosstalk between these pathways remain largely unexplored. (2) Methods: To unravel these interactions, we examined the interplay between JNK and NOX2 in human epithelial cells subjected to silica dust exposure through in vivo assays, followed by validation using single-cell sequencing. Our findings consistently revealed elevated expression levels of key components from both the JNK signaling pathway and NOX2 in the lungs of silicosis-induced mice and silica-treated human epithelial cells. (3) Results: Notably, the activation of these pathways was linked to increased ROS (reactive oxygen species) production, elevated levels of profibrogenic factors, and diminished cell proliferation in silica-exposed human lung epithelial cells. Further mechanistic analyses demonstrated that JNK signaling amplifies NOX2 expression and ROS production induced by silica exposure, while treatment with the JNK inhibitor SP600125 mitigates these effects. Conversely, overexpression of NOX2 enhanced silica-induced JNK activation and the expression of epithelial–mesenchymal transition (EMT)-related factors, whereas NOX2 knockdown exerted the opposite effect. These results suggest a positive feedback loop between JNK and NOX2 signaling, which may drive EMT in lung epithelial cells following silica exposure. (4) Conclusions: This reciprocal interaction appears to play a critical role in lung epithelial cell damage and the pathogenesis of silicosis, shedding light on the molecular mechanisms underlying profibrogenic disease and offering potential avenues for therapeutic intervention. Full article

NADPH oxidase enzymes (NOXs) are a family of enzymes generating superoxide, which form reactive oxygen species. NOX2 activity is a causative agent for the progression of many diseases: neurodegenerative, cardiovascular, immune dysregulations, and even hereditary diseases and cancer. Administering antioxidants helps in inhibiting NOX2 activity; however, the development of selective inhibitors may provide greater improvement in the therapy of diseases. Here, an optimized synthesis of two most promising NOX2 inhibitors based on the 3-(indolin-6-yl)-4-(N-pyrazole-sulfonamide)-1H-pyrrolo [2,3-b]pyridine structure, namely, GSK2795039 and NCATS-SM7270, and an isomeric derivative of the same class, IMBIOC-1, is reported. The new modified procedures simplify the isolation, reduce byproduct formation, and improve the yields in 0.1–1 g scale preparations. Molecular modeling of the structures of NOX2 complexes with inhibitors validated their binding at the same site as NADPH, with IMBIOC-1 forming the largest number of intermolecular interactions with the NOX2 active site. Testing the effects of the compounds on amyloid beta-induced oxidative stress and toxicity in HMC3 microglial cells showed that all three inhibitors completely prevented the pathological amyloid-beta effect. At the same time, NCATS-SM7270 and IMBIOC-1 provided a stronger protective effect on microglial cell survival than GSK2795039, which allowed us to assert the potential of those compounds as neuroprotective agents. Full article

Cadmium (Cd) is a toxic heavy metal that threatens public health, with kidney injury being one of the common manifestations after Cd exposure. Oxidative stress plays a crucial role in Cd-induced kidney injury, arising from an imbalance between cellular oxidation and antioxidation processes. Bromodomain-containing protein 4 (BRD4) has been identified as a significant factor in the initiation and advancement of multiple diseases, primarily due to its regulatory role in oxidative stress. Nevertheless, the specific role of BRD4 in Cd-induced kidney oxidative injury remains poorly understood. The present study demonstrates that BRD4 is activated in the kidney after Cd exposure, while JQ1 (a BRD4 inhibitor) treatment inhibits Cd-induced oxidative stress and kidney injury. Subsequently, we investigate the mechanisms by which Cd regulates oxidative stress both in vivo and in vitro. The results indicate that JQ1 treatment reduces the expression levels of NADPH oxidase 4 (Nox4), thereby alleviating mitochondrial damage and reducing reactive oxygen species (ROS) generation. Furthermore, JQ1 treatment facilitates nuclear translocation levels of Nuclear factor erythroid-derived 2-like 2 (Nrf2), thereby enhancing the antioxidant defense system in the kidney after Cd exposure. In conclusion, this study reveals that BRD4 is significantly involved in the process of Cd-induced oxidative damage in the kidney, while inhibiting BRD4 is observed to attenuate ROS generation by regulating Nox4 and enhance ROS scavenging by regulating Nrf2, which, in turn, suppresses the oxidative stress level in the kidney after Cd exposure. These findings suggest that targeting BRD4 may represent an effective strategy for the prevention and treatment of Cd-induced kidney diseases. Full article

Resistance to PARP inhibitors (PARPi), such as olaparib (OLA), is a major challenge in ovarian cancer treatment. In this study, we investigated the combination effect of PARPi and gukulenin A (GUA), a bis-tropolone tetraterpenoid isolated from the marine sponge Phorbas gukhulensis. We found that GUA at a mildly cytotoxic dose synergistically enhanced OLA-induced cytotoxicity in human ovarian cancer cells. The combination treatment significantly increased reactive oxygen species (ROS) levels and lipid peroxidation, leading to ferroptotic rather than apoptotic cell death. Network pharmacology and gene ontology (GO) enrichment analyses revealed oxidative stress-related pathways as key mediators of this effect. Inhibition of NADPH oxidase (NOX) reversed combination-induced cell death, while ferrostatin-1 (FER-1), a ferroptosis inhibitor, significantly reduced lipid peroxidation and cytotoxicity. Additionally, GUA and OLA treatment suppressed ERK1/2 activation, and ERK overexpression attenuated the combination-induced cell death. Collectively, these findings suggest that marine-derived GUA enhances PARPi efficacy in ovarian cancer cells by inducing ferroptosis through oxidative stress and ERK pathway modulation. Full article

Mechanical unloading leads to profound musculoskeletal degeneration, muscle wasting, and weakness. Understanding the specific signaling pathways involved is essential for uncovering effective interventions. This review provides new perspectives on mechanotransduction pathways, focusing on the critical roles of focal adhesions (FAs) and oxidative stress in skeletal muscle atrophy under mechanical unloading. As pivotal mechanosensors, FAs integrate mechanical and biochemical signals to sustain muscle structural integrity. When disrupted, these complexes impair force transmission, activating proteolytic pathways (e.g., ubiquitin–proteasome system) that accelerate atrophy. Oxidative stress, driven by mitochondrial dysfunction and NADPH oxidase-2 (NOX2) hyperactivation, exacerbates muscle degeneration through excessive reactive oxygen species (ROS) production, impaired repair mechanisms, and dysregulated redox signaling. The interplay between FA dysfunction and oxidative stress underscores the complexity of muscle atrophy pathogenesis: FA destabilization heightens oxidative damage, while ROS overproduction further disrupts FA integrity, creating a self-amplifying vicious cycle. Therapeutic strategies, such as NOX2 inhibitors, mitochondrial-targeted antioxidants, and FAK-activating compounds, promise to mitigate muscle atrophy by preserving mechanotransduction signaling and restoring redox balance. By elucidating these pathways, this review advances the understanding of muscle degeneration during unloading and identifies promising synergistic therapeutic targets, emphasizing the need for combinatorial approaches to disrupt the FA-ROS feedback loop. Full article

Hemp (Cannabis sativa L.) leaf oil (HLO) contains several bioactive compounds such as phenolics, flavonoids, and quercetin. However, the effects of HLO on hypertensive conditions have not yet been investigated. This study investigated the cardiovascular protective effects of HLO in a nitric oxide (NO) synthase inhibitor-induced hypertensive rat model. Five weeks of HLO administration significantly prevented blood pressure elevation, improved cardiac function, and mitigated cardiac hypertrophy. Furthermore, HLO ameliorated vascular dysfunction by reducing sympathetic nerve stimulation-induced vasoconstriction, increasing endothelium-dependent vasorelaxation, as well as decreasing vascular wall thickness and vascular smooth muscle cell proliferation. HLO inhibited renin–angiotensin system (RAS) activation and downregulated angiotensin II type 1 (AT1) receptor and NADPH oxidase expression. Additionally, HLO normalized the circulating NO metabolites, decreased oxidative stress, and enhanced antioxidant status. These findings suggest that HLO protects against cardiovascular dysfunction and preserves its morphology. The mechanism of action might involve the suppression of RAS overactivity and oxidative stress through the Ang II/AT1 receptor/NOX2 pathway in NO-deficient hypertension. Full article