NADPH Oxidases (NOX): An Overview from Discovery, Molecular Mechanisms to Physiology and Pathology

Ferroptosis in schizophrenia: Mechanisms and therapeutic potentials (Review)

Schizophrenia, a complex psychiatric disorder, presents with multifaceted symptoms and important challenges in treatment, primarily due to its pathophysiological complexity, which involves oxidative stress and aberrant iron metabolism. Recent insights into ferroptosis, a unique form of iron‑dependent cell death characterized by lipid peroxidation and antioxidant system failures, open new avenues for understanding the neurobiological foundation of schizophrenia. The present review explores the interplay between ferroptosis and schizophrenia, emphasizing the potential contributions of disrupted iron homeostasis and oxidative mechanisms to the pathology and progression of this disease. The emerging evidence linking ferroptosis with the oxidative stress observed in schizophrenia provides a compelling narrative for re‑evaluating current therapeutic strategies and exploring novel interventions targeting these molecular pathways, such as the glutathione peroxidase 4 pathway and the ferroptosis suppressor protein 1 pathway. By integrating recent advances in ferroptosis research, the current review highlights innovative therapeutic potentials, including N‑acetylcysteine, selenium, omega‑3 fatty acids and iron chelation therapy, which could address the limitations of existing treatments and improve clinical outcomes for individuals with schizophrenia.

NOX4 deficiency improves the impaired viability, inhibited the apoptosis and suppressed autophagy of DHEA-treated ovarian granulosa cells through inhibiting endoplasmic reticulum stress via inactivating PERK/ATF4 pathway

BACKGROUND

PCOS is the most prevalent endocrine and metabolic problem in women of reproductive age. This current study was formulated to thoroughly expound the ovary-protecting effects of NOX4 deficiency in PCOS and probe into the intrinsic mechanisms underlying the protective effects of NOX4 deficiency against DHEA injury in ovarian GCs.

METHODS

KGN cells were subjected to 20 nM DHEA for 48 h to establish PCOS cellular model. For loss-of-function experiments, KGN cells were transfected with si-NOX4. In addition, to investigate the biological roles of ERS and PERK/ATF4 pathway in the ovary-protecting effects of NOX4 deficiency in DHEA-treated ovarian GCs, KGN cells were pretreated with ERS agonist TM or PERK agonist CCT020312.

RESULTS

NOX4 was highly expressed in DHEA-treated ovarian GCs. NOX4 deficiency improved the impaired viability, inhibited the apoptosis and suppressed autophagy of DHEA-treated ovarian GCs. Besides, NOX4 deficiency inactivated PERK/ATF4 pathway in DHEA-treated ovarian GCs. NOX4 deficiency repressed DHEA-induced ERS of ovarian GCs through inactivating PERK/ATF4 pathway. Pretreatment with ERS agonist TM or pretreatment with PERK agonist CCT020312 can both reduced the viability, promoted the apoptosis and strengthened autophagy of ovarian GCs, partially abolishing the ovary-protecting effects of NOX4 deficiency in DHEA-treated ovarian GCs. In general, NOX4 deficiency could improve the impaired viability, inhibited the apoptosis and suppressed autophagy of DHEA-treated ovarian GCs through repressing ERS depending on inactivation of PERK/ATF4 pathway.

CONCLUSION

To conclude, downregulation of NOX4 could exert ovary-protecting effects in DHEA-induced PCOS cellular model through repressing ERS via inactivating PERK/ATF4 pathway.

Safeguarding the brain from oxidative damage

Oxidative stress imposes a substantial cellular burden on the brain and contributes to diverse neurodegenerative diseases. Various antioxidant signaling pathways have been implicated in oxidative stress and have a protective effect on brain cells by increasing the release of numerous enzymes and through anti-inflammatory responses to oxidative damage caused by abnormal levels of reactive oxygen species (ROS). Although many molecules evaluated as antioxidants have shown therapeutic potentials in preclinical studies, the results of clinical trials have been less than satisfactory. This review focuses on several signaling pathways involved in oxidative stress that are associated with antioxidants. These pathways have a protective effect against stressors by increasing the release of various enzymes and also exert anti-inflammatory responses against oxidative damage. There is no doubt that oxidative stress is a crucial therapeutic target in the treatment of neurological diseases. Therefore, it is essential to understand the discovery of multiple routes that can efficiently repair the damage caused by ROS and prevent neurodegenerative disorders. This paper aims to provide a concise and objective review of the oxidative and antioxidant pathways and their potential therapeutic applications in treating oxidative injury in the brain.

NOX proteins and ROS generation: role in invadopodia formation and cancer cell invasion

NADPH oxidases (NOX) are membrane-bound proteins involved in the localized generation of reactive oxygen species (ROS) at the cellular surface. In cancer, these highly reactive molecules primarily originate in mitochondria and via NOX, playing a crucial role in regulating fundamental cellular processes such as cell survival, angiogenesis, migration, invasion, and metastasis. The NOX protein family comprises seven members (NOX1-5 and DUOX1-2), each sharing a catalytic domain and an intracellular dehydrogenase site. NOX-derived ROS promote invadopodia formation, aberrant tyrosine kinase activation, and upregulation of matrix metalloproteinases (MMPs). Specifically, NOX5 modulates adhesion, motility, and proteolytic activation, while NOX1 likely contributes to invadopodia formation and adhesive capacity. NOX2 and NOX4 are implicated in regulating the invasive phenotype, expression of MMPs and EMT markers. DUOX1-2 participate in epithelial-mesenchymal transition (EMT), crucial for invasive phenotype development. Soluble molecules such as TGF-β and EGF modulate NOX protein activation, enhancing cell invasion through localized ROS production. This review focuses on elucidating the specific role of NOX proteins in regulating signaling pathways promoting cancer cell spread, particularly EMT, invadopodia formation and invasive capacity.

To activate NAD(P)H oxidase with a brief pulse of photodynamic action

Reduced nicotinamide adenine dinucleotide phosphate [NAD(P)H] oxidases (NOX) are a major cellular source of reactive oxygen species, regulating vital physiological functions, whose dys-regulation leads to a plethora of major diseases. Much effort has been made to develop varied types of NOX inhibitors, but biotechnologies for spatially and temporally controlled NOX activation, however, are not readily available. We previously found that ultraviolet A (UVA) irradiation activates NOX2 in rodent mast cells, to elicit persistent calcium spikes. NOX2 is composed of multiple subunits, making studies of its activation rather complicated. Here we show that the single-subunit nonrodent-expressing NOX5, when expressed ectopically in CHO-K1 cells, is activated by UVA irradiation (380 nm, 0.1-12 mW/cm2, 1.5 min) inducing repetitive calcium spikes, as monitored by Fura-2 fluorescent calcium imaging. UVA-elicited calcium oscillations are inhibited by NOX inhibitor diphenyleneiodonium chloride (DPI) and blocked by singlet oxygen (1O2) quencher Trolox-C (300 μM). A brief pulse of photodynamic action (1.5 min) with photosensitizer sulfonated aluminum phthalocyanine (SALPC 2 μM, 675 nm, 85 mW/cm2) in NOX5-CHO-K1 cells, or with genetically encoded protein photosensitizer miniSOG fused to N-terminus of NOX5 (450 nm, 85 mW/cm2) in miniSOG-NOX5-CHO-K1 cells, induces persistent calcium oscillations, which are blocked by DPI. In the presence of Trolox-C, miniSOG photodynamic action no longer induces any calcium increases in miniSOG-NOX5-CHO-K1 cells. DUOX2 in human thyroid follicular cells SW579 and in DUOX2-CHO-K1 cells is similarly activated by UVA irradiation and SALPC photodynamic action. These data together suggest that NOX   is activated with a brief pulse of photodynamic action.

From Bench to Bedside: ROS-Responsive Nanocarriers in Cancer Therapy

Reactive oxygen species (ROS) play a dual role in cancer, acting as both signaling molecules that promote tumour growth and as agents that can inhibit tumour progression through cytotoxic effects. In cancer therapy, ROS-responsive drug delivery systems take advantage of the elevated ROS levels found in tumors compared to healthy tissues. These systems are engineered to release drugs precisely in response to increased ROS levels in tumour cells, allowing targeted and controlled treatment, minimizing side effects, and enhancing therapeutic outcomes. ROS generation in cancer cells is linked to metabolic changes, mitochondrial dysfunction, and oncogenic signaling, leading to increased oxidative stress. Tumour cells manage this by upregulating antioxidant defenses to prevent ROS from reaching harmful levels. This balance between ROS production and neutralization is critical for cancer cell survival, making ROS both a challenge and an opportunity for targeted therapies. ROS also connect inflammation and cancer. Chronic inflammation leads to elevated ROS, which can damage DNA and proteins, promoting mutations and cancer development. Additionally, ROS contribute to protein degradation, affecting essential cellular functions. Therapeutic strategies targeting ROS aim to either increase ROS beyond tolerable levels for cancer cells or inhibit their antioxidant defenses. Nanocarriers responsive to ROS show great potential in improving the precision of cancer treatments by releasing drugs specifically in high ROS environments, like tumors. This review discusses the mechanisms of ROS in cancer, its role in inflammation and protein degradation, and the advances in ROS-targeted nanocarrier therapies across different cancer types.

Identification of oxidative stress biomarkers in apical periodontitis: A scoping review with bibliometric analysis

Oxidative stress (OS) is a ubiquitous process for protecting against microorganisms' challenges. This review maps the most used methods for obtaining samples and analysing reactive oxygen species levels in apical periodontitis, following the PRISMA Extension for Scoping Reviews and is registered in Open Science Framework ([https://doi.org/10.17605/OSF.IO/D5U76]). A systematic search was conducted in electronic databases MEDLINE (PubMed), Embase, Scopus, Web of Science, LILACS, SciElo, OATD and DANS up to 17 July 2023. A total of 18 studies were included, with periapical tissue being the most common sample. Twenty-eight different oxidative stress markers were identified, with inducible nitric oxide synthase being the most prevalent. The use of diverse biomarkers for oxidative stress assessment lacks specificity in identifying particular OS species for evaluating apical periodontitis and potential systemic effects. Studies are necessary to compare results obtained from less invasive methods (such as saliva and crevicular fluid) with those from periapical lesion samples.

Targeting pericyte retention in Diabetic Retinopathy: a review

Diabetic retinopathy is a common yet severe complication of diabetes mellitus and is the leading cause of blindness in middle-aged adults. After years of poorly managed hyperglycemia, complications begin as non-proliferative diabetic retinopathy but can then progress into the proliferative stage marked by neovascularization of the retina. Multiple pathologic mechanisms caused by chronic hyperglycemia damage the retinal vasculature leading to pericyte drop out and the progression of the disease. This review outlines the major pathways of pathogenesis in diabetic retinopathy, highlighting the protective role pericytes play in preserving the blood-retinal barrier. Given the loss of this cell line is a defining feature of the disease, ways in which to prevent pericyte dropout within retinal vasculature is discussed, targeting various pathogenesis pathways of diabetic retinopathy.

Regulation of NLRPs by reactive oxygen species: A story of crosstalk

The nucleotide oligomerization domain (NOD)-like receptors containing pyrin (NLRP) family of cytosolic pattern-recognition receptors play an integral role in host defense following exposure to a diverse set of pathogenic and sterile threats. The canonical event following ligand recognition is the formation of a heterooligomeric signaling complex termed the inflammasome that produces pro-inflammatory cytokines. Dysregulation of this process is associated with many autoimmune, cardiovascular, metabolic, and neurodegenerative diseases. Despite the range of activating stimuli which affect varied cell types, recent literature makes evident that reactive oxygen species (ROS) are integral to the initiation and propagation of inflammasome signaling. Notably, ROS production and inflammasome activation act in a positive feedback loop to promote this potent immune response. While NLRP3 is by far the most extensively studied NLRP, there is also sufficient literature to make these conclusions for other NLRPs family members. In all cases, a knowledge gap exists regarding the molecular targets and effects of ROS. Future research to define these targets and to parse the order and timing of ROS-mediated NLRP activation will provide meaningful insights into inflammasome biology. This will create novel therapeutic opportunities for the numerous illnesses that are impacted by inflammasome activity.

Nebivolol prevents redox imbalance and attenuates bladder dysfunction induced by cyclophosphamide in mice

Cyclophosphamide (CYP) is combined with cytoprotective agents to minimize its toxicity in the bladder, which is mediated by reactive oxygen species (ROS). Using multiple antioxidant mechanisms, nebivolol protects from oxidative stress in distinctive conditions. We hypothesized that nebivolol would attenuate both molecular and functional alterations induced by CYP in the bladder. Male C57BL/6 were pretreated or not with nebivolol (10 mg/kg/day, gavage), which was given 5 days before a single injection of CYP (300 mg/kg; i.p.). Molecular and functional parameters were assessed at 24 h in the bladder. Nebivolol prevented increases in ROS generation and lipoperoxidation as well as reduction of superoxide dismutase activity induced by CYP. Increased voiding frequency, decreased voiding interval, and reduced bladder capacity were found in CYP-treated mice. These responses were prevented by nebivolol. An augmented number of urinary spots and smaller urinary volumes were detected in CYP-injected mice, and nebivolol partially prevented these responses. The reduction of ROS levels is the primary mechanism by which nebivolol attenuates the deleterious effects of CYP in the bladder. The association of nebivolol with other cytoprotective agents could be an option to prevent CYP-associated oxidative damage to the bladder during chemotherapy.

Adjuvant therapy with zinc supplementation; anti-inflammatory and anti-oxidative role in multiple myeloma patients receiving autologous hematopoietic stem cell transplantation: a randomized controlled clinical trial

Multiple myeloma (MM) patients are often accompanied by heightened levels of oxidative stress, even following bone marrow transplantation. Trace mineral supplements have been found to regulate and inhibit the activity of oxidative radicals and inflammatory factors, which are involved in the pathogenesis of MM. The study sought to evaluate the effectiveness of the supplementation by analyzing changes in oxidative, anti-oxidative, and inflammation markers. Patients were randomly assigned to a zinc or placebo group, with the former receiving 30 mg of zinc or placebo tablets daily for 1 month. Blood samples were collected from the patients on the day of transplantation, 15 days, and 30 days post-transplantation. Real-time PCR was employed to measure the expression of oxidative/antioxidative genes. Furthermore, the protein level of oxidative markers in serum samples was assessed. Finally, serum TNF-α concentrations were measured using the ELISA technique. The expression levels of SOD1, SOD2, and NRF2 genes were significantly higher on days 15 and 30 compared to the control group (P < 0.05), with a greater increase on day 30 (P < 0.05). Conversely, the expression levels of Keap1 and NOX2 genes were lower on day 30 than those of the control group (P < 0.05), with a further decrease from day 15 to day 30 (P < 0.05). The experimental group exhibited a notable reduction in TNF-α cytokine levels on day 30 compared to the control and placebo groups (P < 0.05). All findings were coordinated according to the nutritional questionnaire. Our findings suggest a potential benefit of zinc supplementation in managing the adverse effects of chemotherapy in MM patients, warranting further investigation.

NOX2 in Alzheimer's and Parkinson's disease

Alzheimer's Disease (AD), and related dementias, represent a growing concern for the worldwide population given the increased numbers of people of advanced age. Marked by significant degradation of neurological tissues and critical processes, in addition to more specific factors such as the presence of amyloid plaques and neurofibrillary tangles in AD, robust discussion is ongoing regarding the precise mechanisms by which these diseases arise. One of the major interests in recent years has been the contribution of reactive oxygen species (ROS) and, particularly, the contribution of the ROS-generating NADPH Oxidase proteins. NADPH Oxidase 2 (NOX2), the prototypical member of the family, represents a particularly interesting target for study given its close association with vascular and inflammatory processes in all tissues, including the brain, and the association of these processes with AD development and progression. In this review, we discuss the most relevant and recent work regarding the contribution of NOX2 to AD progression in neuronal, microglial, and cerebrovascular signaling. Furthermore, we will discuss the most promising NOX2-targeted therapeutics for potential AD management and treatment.

Multifaceted roles of NADPH oxidases in the growth and pathogenicity of Beauveria bassiana

Reactive oxygen species (ROS), synthesized by the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox) complex, are vital molecules in biological cells, influencing various physiological processes such as fungal growth, development, and virulence. Beauveria bassiana, an entomopathogenic fungus, is a promising biopesticide for agricultural, forestry, and urban pest control. This study focuses on the characterization of NADPH oxidases (Noxs) in B. bassiana. Gene expression profiles of Noxs in B. bassiana (BbNoxs) were analysed using RT-qPCR. Knockout strains of single BbNoxA, BbNoxB, BbNoxR, and double BbNoxA and BbNoxB were constructed via homologous recombination, and their phenotypic characteristics were examined. Fungal virulence was evaluated using Galleria mellonella larvae, and infection structures formation and penetration ability were assessed on cicada wings. ROS production and actin assembly during fungal growth and infection were detected using staining and marker methods. Expression analysis revealed significant upregulation of BbNoxs during fungal growth and infection. Compared to the wild-type strain, single knockouts (ΔBbNoxA/B/R) and double knockout (ΔBbNoxAB) of BbNoxs exhibited reduced conidial yields, accelerated conidial germination rates. Deletion of BbNoxB or BbNoxR decreased fungal virulence compared to the WT strain in topical inoculation experiments. Additionally, loss of BbNoxB or BbNoxR impaired infection structures formation, penetration ability, ROS production, and actin aggregation during fungal infection. BbNoxs are crucial for fungal growth, development, and virulence in B. bassiana, playing essential roles in infection structures formation, penetration, ROS production, and actin assembly. Understanding their functions provides insights into B. bassiana's pathogenic mechanisms.

Perspective: Pathological transdifferentiation-a novel therapeutic target for cardiovascular diseases and chronic inflammation

Pathological transdifferentiation, where differentiated cells aberrantly transform into other cell types that exacerbate disease rather than promote healing, represents a novel and significant concept. This perspective discusses its role and potential targeting in cardiovascular diseases and chronic inflammation. Current therapies mainly focus on mitigating early inflammatory response through proinflammatory cytokines and pathways targeting, including corticosteroids, TNF-α inhibitors, IL-1β monoclonal antibodies and blockers, IL-6 blockers, and nonsteroidal anti-inflammatory drugs (NSAIDs), along with modulating innate immune memory (trained immunity). However, these approaches often fail to address long-term tissue damage and functional regeneration. For instance, fibroblasts can transdifferentiate into myofibroblasts in cardiac fibrosis, and endothelial cells may undergo endothelial to mesenchymal transition (EndMT) in vascular remodeling, resulting in fibrosis and impaired tissue function. Targeting pathological transdifferentiation represents a promising therapeutic avenue by focusing on key signaling pathways that drive these aberrant cellular phenotypic and transcriptomic transitions. This approach seeks to inhibit these pathways or modulate cellular plasticity to promote effective tissue regeneration and prevent fibrosis. Such strategies have the potential to address inflammation, cell death, and the resulting tissue damage, providing a more comprehensive and sustainable treatment solution. Future research should focus on understanding the mechanisms behind pathological transdifferentiation, identifying relevant biomarkers and master regulators, and developing novel therapies through preclinical and clinical trials. Integrating these new therapies with existing anti-inflammatory treatments could enhance efficacy and improve patient outcomes. Highlighting pathological transdifferentiation as a therapeutic target could transform treatment paradigms, leading to better management and functional recovery of cardiovascular tissues in diseases and chronic inflammation.

Role of Rho-associated kinases and their inhibitor fasudil in neurodegenerative diseases

Neurodegenerative diseases (NDDs) are prevalent in the elderly. The pathogenesis of NDDs is complex, and currently, there is no cure available. With the increase in aging population, over 20 million people are affected by common NDDs alone (Alzheimer's disease and Parkinson's disease). Therefore, NDDs have profound negative impacts on patients, their families, and society, making them a major global health concern. Rho-associated kinases (ROCKs) belong to the serine/threonine protein kinases family, which modulate diverse cellular processes (e.g., apoptosis). ROCKs may elevate the risk of various NDDs (including Huntington's disease, Parkinson's disease, and Alzheimer's disease) by disrupting synaptic plasticity and promoting inflammatory responses. Therefore, ROCK inhibitors have been regarded as ideal therapies for NDDs in recent years. Fasudil, one of the classic ROCK inhibitor, is a potential drug for treating NDDs, as it repairs nerve damage and promotes axonal regeneration. Thus, the current review summarizes the relationship between ROCKs and NDDs and the mechanism by which fasudil inhibits ROCKs to provide new ideas for the treatment of NDDs.

Sea food by-products valorization for biomedical applications: evaluation of their wound regeneration capabilities in an Ex vivo skin model

Introduction

The skin is often exposed to harmful stimuli that might compromise its integrity and functionality. After an injury, the skin has a limited capability to restore its complex structure, and in the case of severe skin damage, surgical operations and rapid application of wound dressings are often required to promote optimal wound healing. Nowadays, collagen-based biomaterials are widely used in combination with bioactive molecules able to prevent excessive inflammation and possible infections. In line with a circular economy and blue biotechnology approach, it was recently demonstrated that both collagen and bioactive molecules (i.e., antioxidant compounds) can be sustainably obtained from sea food by-products and effectively used for biomaterial development. Herein, we describe and compare the application of two marine collagen-based wound dressings (CBWDs), produced with materials obtained from sea urchin food waste, for the treatment of skin lesions in a wound healing organ culture (WHOC) model.

Methods

The ex vivo WHOC model was set up starting from rat skin explants and the induced lesions were assigned into three different groups: control (CTRL) group, not treated, marine collagen wound dressing (MCWD) group, and antioxidants-enriched marine collagen wound dressing (A-MCWD) group. After 5 and 10 days, specimens were examined for organ maintenance and assessed for the healing process.

Results

Immunohistochemical results showed that both CBWDs were similarly successful in prolonging skin repair, preserving the epidermal barrier up to 5 days under static culture conditions. Histological and gene expression analysis highlighted that the A-MCWD might support and accelerate skin wound healing by exerting antioxidant activity and counteracting inflammation.

Discussion

Overall, these findings underline the potential of sea urchin food waste as a novel resource for the development of functional medical devices for the treatment of skin wounds.

Molecular Roles of NADPH Oxidase-Mediated Oxidative Stress in Alzheimer's Disease: Isoform-Specific Contributions

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.

The interplay between ferroptosis and inflammation: therapeutic implications for cerebral ischemia-reperfusion

Stroke ranks as the second most significant contributor to mortality worldwide and is a major factor in disability. Ischemic strokes account for 71% of all stroke incidences globally. The foremost approach to treating ischemic stroke prioritizes quick reperfusion, involving methods such as intravenous thrombolysis and endovascular thrombectomy. These techniques can reduce disability but necessitate immediate intervention. After cerebral ischemia, inflammation rapidly arises in the vascular system, producing pro-inflammatory signals that activate immune cells, which in turn worsen neuronal injury. Following reperfusion, an overload of intracellular iron triggers the Fenton reaction, resulting in an excess of free radicals that cause lipid peroxidation and damage to cellular membranes, ultimately leading to ferroptosis. The relationship between inflammation and ferroptosis is increasingly recognized as vital in the process of cerebral ischemia-reperfusion (I/R). Inflammatory processes disturb iron balance and encourage lipid peroxidation (LPO) through neuroglial cells, while also reducing the activity of antioxidant systems, contributing to ferroptosis. Furthermore, the lipid peroxidation products generated during ferroptosis, along with damage-associated molecular patterns (DAMPs) released from ruptured cell membranes, can incite inflammation. Given the complex relationship between ferroptosis and inflammation, investigating their interaction in brain I/R is crucial for understanding disease development and creating innovative therapeutic options. Consequently, this article will provide a comprehensive introduction of the mechanisms linking ferroptosis and neuroinflammation, as well as evaluate potential treatment modalities, with the goal of presenting various insights for alleviating brain I/R injury and exploring new therapeutic avenues.

Catalytic Biomaterials-Activated In Situ Chemical Reactions: Strategic Modulation and Enhanced Disease Treatment

Chemical reactions underpin biological processes, and imbalances in critical biochemical pathways within organisms can lead to the onset of severe diseases. Within this context, the emerging field of "Nanocatalytic Medicine" leverages nanomaterials as catalysts to modulate fundamental chemical reactions specific to the microenvironments of diseases. This approach is designed to facilitate the targeted synthesis and localized accumulation of therapeutic agents, thus enhancing treatment efficacy and precision while simultaneously reducing systemic side effects. The effectiveness of these nanocatalytic strategies critically hinges on a profound understanding of chemical kinetics and the intricate interplay of reactions within particular pathological microenvironments to ensure targeted and effective catalytic actions. This review methodically explores in situ catalytic reactions and their associated biomaterials, emphasizing regulatory strategies that control therapeutic responses. Furthermore, the discussion encapsulates the crucial elements-reactants, catalysts, and reaction conditions/environments-necessary for optimizing the thermodynamics and kinetics of these reactions, while rigorously addressing both the biochemical and biophysical dimensions of the disease microenvironments to enhance therapeutic outcomes. It seeks to clarify the mechanisms underpinning catalytic biomaterials and evaluate their potential to revolutionize treatment strategies across various pathological conditions.

Regulation of cardiovascular diseases by histone deacetylases and NADPH oxidases

Histone deacetylases (HDACs) play critical roles in cardiovascular diseases (CVDs). In addition, reactive oxygen species (ROS) produced by NADPH oxidases (NOXs) exert damaging effects due to oxidative stress on heart and blood vessels. Although NOX-dependent ROS production is implicated in pathogenesis, the relationship between HDACs and NOXs in CVDs remains to be elucidated. Here, we present an overview of the regulatory effects and interconnected signaling pathways of HDACs and NOXs in CVDs. Improved insights into these relationships will facilitate the discovery of novel therapeutic agents that target HDACs, oxidase stress pathways, and the interactions between these systems which may be highly effective in the prevention and treatment of cardiovascular disorders.

Structural and mechanistic insights into Streptococcus pneumoniae NADPH oxidase

Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs) have a major role in the physiology of eukaryotic cells by mediating reactive oxygen species production. Evolutionarily distant proteins with the NOX catalytic core have been found in bacteria, including Streptococcus pneumoniae NOX (SpNOX), which is proposed as a model for studying NOXs because of its high activity and stability in detergent micelles. We present here cryo-electron microscopy structures of substrate-free and nicotinamide adenine dinucleotide (NADH)-bound SpNOX and of NADPH-bound wild-type and F397A SpNOX under turnover conditions. These high-resolution structures provide insights into the electron-transfer pathway and reveal a hydride-transfer mechanism regulated by the displacement of F397. We conducted structure-guided mutagenesis and biochemical analyses that explain the absence of substrate specificity toward NADPH and suggest the mechanism behind constitutive activity. Our study presents the structural basis underlying SpNOX enzymatic activity and sheds light on its potential in vivo function.

Hypoxia-Induced Mitochondrial ROS and Function in Pulmonary Arterial Endothelial Cells

Pulmonary artery endothelial cells (PAECs) are a major contributor to hypoxic pulmonary hypertension (PH) due to the possible roles of reactive oxygen species (ROS). However, the molecular mechanisms and functional roles of ROS in PAECs are not well established. In this study, we first used Amplex UltraRed reagent to assess hydrogen peroxide (H2O2) generation. The result indicated that hypoxic exposure resulted in a significant increase in Amplex UltraRed-derived fluorescence (i.e., H2O2 production) in human PAECs. To complement this result, we employed lucigenin as a probe to detect superoxide (O2-) production. Our assays showed that hypoxia largely increased O2- production. Hypoxia also enhanced H2O2 production in the mitochondria from PAECs. Using the genetically encoded H2O2 sensor HyPer, we further revealed the hypoxic ROS production in PAECs, which was fully blocked by the mitochondrial inhibitor rotenone or myxothiazol. Interestingly, hypoxia caused an increase in the migration of PAECs, determined by scratch wound assay. In contrast, nicotine, a major cigarette or e-cigarette component, had no effect. Moreover, hypoxia and nicotine co-exposure further increased migration. Transfection of lentiviral shRNAs specific for the mitochondrial Rieske iron-sulfur protein (RISP), which knocked down its expression and associated ROS generation, inhibited the hypoxic migration of PAECs. Hypoxia largely increased the proliferation of PAECs, determined using Ki67 staining and direct cell number accounting. Similarly, nicotine caused a large increase in proliferation. Moreover, hypoxia/nicotine co-exposure elicited a further increase in cell proliferation. RISP knockdown inhibited the proliferation of PAECs following hypoxia, nicotine exposure, and hypoxia/nicotine co-exposure. Taken together, our data demonstrate that hypoxia increases RISP-mediated mitochondrial ROS production, migration, and proliferation in human PAECs; nicotine has no effect on migration, increases proliferation, and promotes hypoxic proliferation; the effects of nicotine are largely mediated by RISP-dependent mitochondrial ROS signaling. Conceivably, PAECs may contribute to PH via the RISP-mediated mitochondrial ROS.

NoxO1 regulates EGFR signaling by its interaction with Erbin

NADPH oxidase organizer 1 (NoxO1) is a scaffold cytoplasmic subunit of the reactive oxygen species (ROS) forming Nox1 complex and involved in angiogenesis, differentiation, and atherosclerosis. We found that overexpression of NoxO1 without simultaneous overexpression of any other component of the active Nox1 complex inhibited EGF-induced wound closure and signaling, while NoxO1 KO yielded the opposite effect. Accordingly, we hypothesize NoxO1 to exert Nox1 independent functions. Using the BioID technique, we identified ErbB2 interacting protein (Erbin) as novel interaction partner of NoxO1. Colocalization of NoxO1 with EGFR, as well as with Erbin validated this finding. EGF treatment interrupted colocalization of NoxO1 and EGFR. EGF mediated kinase activation was delayed in NoxO1 overexpressing cells, while knockout of NoxO1 had the opposite effect. In conclusion, Erbin was identified as a novel NoxO1 interacting protein. Through the subsequent interaction of NoxO1 and EGFR, NoxO1 interferes with EGF signaling. The results of this study suggest a potential role of NoxO1 as an adaptor protein with functions beyond the well-established enabling of Nox1 mediated ROS formation.

Screening of m6A-associated ferroptosis-related genes in atherosclerosis based on WGCNA

Background

N6-methyladenosine (m6A) has been shown to mediate ferroptosis but its role in atherosclerosis (AS) is unclear.

Methods

Differentially expressed m6A-associated ferroptosis-related genes (DE-m6A-Ferr-RGs) were obtained using differential expression analysis and Pearson correlation analysis. Weighted gene co-expression network analysis (WGCNA) was also performed. The intersection of the module genes and the DE-m6A-Ferr-RGs were recorded as candidate m6A-Ferr-related signature genes. Finally, the m6A-Ferr-related signature genes were screened using least absolute shrinkage and selection operator (LASSO) analysis. Expression validation, receiver operating characteristic ( mapping, and immune correlation analysis were also performed based on the m6A-Ferr-related signature genes. The expression of m6A-Ferr-related signature genes was further validated using a real-time polymerase chain reaction (RT-qPCR).

Results

In total, 6,167 differentially expressed genes were intersected with 24 m6A- and 259 ferroptosis-related genes, respectively, resulting in 113 DE-m6A-Ferr-RGs obtained using Pearson's correlation analysis. The module genes obtained from the WGCNA and the 113 DE-m6A-Ferr-RGs were intersected to obtain 48 candidate m6A-Ferr-related signature genes. LASSO analysis was performed and six m6A-Ferr-related signature genes were screened. In addition, the area under the curve values of all six m6A-Ferr-related signature genes were greater than 0.7, indicating that they had potential diagnostic value. Furthermore, the RT-qPCR results revealed that the expression of SLC3A2, NOX4, and CDO1 was consistent with the transcriptome level. Moreover, there was a significant difference in two types of immune cells between the AS and control groups. Naive B cells, CD8+ T cells, regulatory T cells, and activated natural killer cells were positively correlated with CDO1 and NOX4 but negatively correlated with ATG7, CYBB, and SLC3A2.

Conclusion

In total, three m6A-Ferr-related signature genes (NOX4, CDO1, and SLC3A2) were obtained through a series of bioinformatics analyses and an RT-qPCR.

Selected Trace Elements and Their Impact on Redox Homeostasis in Eye Health

Oxidative stress plays a crucial role in the pathogenesis of various ocular degenerative diseases, leading to structural and functional changes in eye tissues. This imbalance between reactive oxygen species (ROS) and antioxidants significantly contributes to conditions such as age-related macular degeneration, diabetic retinopathy, cataracts, and glaucoma. Both enzymatic and nonenzymatic antioxidants are vital for maintaining ocular health by neutralizing ROS and restoring cellular redox balance. Essential trace elements, including iron, zinc, copper, and selenium, are fundamental for the proper functioning of these antioxidant systems. Iron is indispensable for enzymatic activity and cellular energy production, zinc supports numerous proteins involved in visual functions and antioxidant defense, copper is essential for various enzymatic reactions preventing oxidative stress, and selenium is critical for the activity of antioxidant enzymes such as glutathione peroxidase (GPX) and thioredoxin reductase (TrxR). This review summarizes current research on the complex interactions between oxidative stress and trace elements in ocular diseases, highlighting the therapeutic potential of antioxidant supplementation to mitigate oxidative damage and improve eye health. By integrating insights from studies on oxidative stress, trace elements, and eye physiology, this article underscores new diagnostic and therapeutic strategies that could lead to more effective prevention and treatment of ocular diseases, aiming to enhance clinical outcomes and guide future research in optimizing therapeutic strategies for eye health.

Lomitapide: navigating cardiovascular challenges with innovative therapies

Dyslipidemia is the most significant risk factor for cardiovascular diseases (CVDs) Secondary dyslipidemia: its treatments and association with atherosclerosis. Glob Health Med, Efficacy and safety of saroglitazar for the management of dyslipidemia: A systematic review and meta-analysis of interventional studies. The current treatment strategies for managing dyslipidemia focus on reducing low-density lipoprotein cholesterol (LDL-C) to minimize the risks of atherosclerosis and myocardial infarction (MI). Homozygous Familial Hypercholesterolemia (HoFH) is an inherited autosomal dominant disease caused by a mutation in the LDL receptor (LDLr), which can lead to extremely high levels of LDL-C The Beneficial Effect of Lomitapide on the Cardiovascular System in LDLr(-/-) Mice with Obesity, The microsomal triglyceride transfer protein inhibitor lomitapide improves vascular function in mice with obesity. Although statin therapy has been the primary treatment for dyslipidemia, HoFH patients do not respond well to statins, requiring alternative therapies. Microsomal triglyceride transfer protein (MTP) inhibition has emerged as a potential therapeutic target for treating HoFH. MTP is primarily responsible for transferring triglyceride and other lipids into apolipoprotein B (ApoB) during the assembly of very low-density lipoprotein (VLDL) particles in the liver. Lomitapide, an inhibitor of MTP, has been approved for treatingof HoFH adults. Unlike statins, lomitapide does not act on the LDLr to reduce cholesterol. Instead, lomitapide lowers the levels of ApoB-containing proteins, primarily VLDL, eventually decreasing LDL-C levels. Studies have shown that lomitapide can reduce LDL-C levels by more than 50% in patients with HoFH who have failed to respond adequately to other treatments. Lowering LDL-C levels is important for preventing atherosclerosis, reducing cardiovascular risk, improving endothelial function, and promoting overall cardiovascular health, especially for patients with HoFH Efficacy and safety of a microsomal triglyceride transfer protein inhibitor in patients with homozygous familial hypercholesterolaemia: a single-arm, open-label, phase 3 study. This review paper focuses on research findings regarding the therapeutic benefits of lomitapide, highlighting its effectiveness in lowering cholesterol levels and reducing the risk of CVDs The microsomal triglyceride transfer protein inhibitor lomitapide improves vascular function in mice with obesity.

Asiaticoside improves diabetic nephropathy by reducing inflammation, oxidative stress, and fibrosis: An in vitro and in vivo study

BACKGROUND

Diabetic nephropathy (DN) is a severe microvascular complication of diabetes characterized by inflammation, oxidative stress, and renal fibrosis. Asiaticoside (AC) exhibits anti-inflammatory, antioxidant, and anti-fibrotic properties, suggesting potential therapeutic benefits for DN. This study aimed to investigate the protective effects of AC against DN and elucidate the underlying mechanisms involving the nuclear factor erythroid 2-related factor 2 (NRF2)/heme oxygenase-1 (HO-1) antioxidant pathway.

AIM

To investigate the renoprotective effects of AC against DN and elucidate the role of the NRF2/HO-1 pathway.

METHODS

The effects of AC on high glucose (HG)-induced proliferation, inflammation, oxidative stress, and fibrosis were evaluated in rat glomerular mesangial cells (HBZY-1) in vitro. A streptozotocin-induced DN rat model was established to assess the in vivo impact of AC on renal injury, inflammation, oxidative stress, and fibrosis. The involvement of the NRF2/HO-1 pathway was examined using pharmacological inhibition studies in the cell model.

RESULTS

AC inhibited HG-induced HBZY-1 cell proliferation and significantly improved various indicators of DN in rats, including reduced body weight, and elevated blood glucose, serum creatinine, blood urea nitrogen, and 24-h urine protein. Both in vitro and in vivo studies demonstrated that AC decreased inflammation and oxidative stress by reducing interleukin (IL)-6, IL-8, tumor necrosis factor-alpha, reactive oxygen species, and malondialdehyde levels while increasing superoxide dismutase activity. Additionally, AC suppressed the expression of fibrogenic markers such as collagen I, collagen IV, and fibronectin. AC activated NRF2 expression in the nucleus and increased HO-1 and NAD(P)H dehydrogenase (Quinone) 1 protein expression in renal tissues and HG-induced HBZY-1 cells.

CONCLUSION

AC improves DN by reducing inflammation, oxidative stress, and fibrosis through the activation of the NRF2/HO-1 signaling pathway. These findings not only highlight AC as a promising therapeutic candidate for DN but also underscore the potential of targeting the NRF2/HO-1 pathway in developing novel treatments for other chronic kidney diseases characterized by oxidative stress and inflammation.

NADPH Oxidases-Inspired Reactive Oxygen Biocatalysts with Electron-Rich Pt Sites to Potently Amplify Immune Checkpoint Blockade Therapy

Clinical immune checkpoint blockade (ICB)-based immunotherapy of malignant tumors only elicits durable responses in a minority of patients, primarily due to the highly immunosuppressive tumor microenvironment. Although inducing immunogenic cell death (ICD) through reactive oxygen biocatalyst represents an attractive therapeutic strategy to amplify ICB, currently reported biocatalysts encounter insurmountable challenges in achieving high ROS-generating activity to induce potent ICD. Here, inspired by the natural catalytic characteristics of NADPH oxidases, the design of efficient, robust, and electron-rich Pt-based redox centers on the non-stoichiometric W18O49 substrates (Pt─WOx) to serve as bioinspired reactive oxygen biocatalysts to potently activate the ICD, which eventually enhance cancer immune responses and amplifies the ICB-based immunotherapy is reported. These studies demonstrate that the Pt─WOx exhibits rapid electron transfer capability and can promote the formation of electron-rich and low oxophilic Pt redox centers for superior reactive oxygen biocatalysis, which enables the Pt─WOx-based inducers to trigger endoplasmic reticulum stress directly and stimulate immune responses potently for amplifying the anti-PD-L1-based ICB therapy. This bioinspired design provides a straightforward strategy to engineer efficient, robust, and electron-rich reactive oxygen biocatalysts and also opens up a new avenue to create efficient ICD inducers for primary/metastatic tumor treatments.

Porphyromonas gingivalis triggers microglia activation and neurodegenerative processes through NOX4

Periodontitis and infections with periodontal bacteria have been highlighted as risk factors for dementia. In recent years, attention has been drawn to the role of microglia cells in neurodegenerative diseases. However, there is limited knowledge of the influence of periodontal bacteria on microglia cells. The aim of the present study was to investigate the interactions between the periodontal bacteria Porphyromonas gingivalis and microglia cells and to unravel whether these interactions could contribute to the pathology of Alzheimer's disease. We found, through microarray analysis, that stimulation of microglia cells with P. gingivalis resulted in the upregulation of several Alzheimer's disease-associated genes, including NOX4. We also showed that P. gingivalis lipopolysaccharides (LPS) mediated reactive oxygen species (ROS) production and interleukin 6 (IL-6) and interleukin 8 (IL-8) induction via NOX4 in microglia. The viability of neurons was shown to be reduced by conditioned media from microglia cells stimulated with P. gingivalis LPS and the reduction was NOX4 dependent. The levels of total and phosphorylated tau in neurons were increased by conditioned media from microglia cells stimulated with P. gingivalis or LPS. This increase was NOX4-dependent. In summary, our findings provide us with a potential mechanistic explanation of how the periodontal pathogen P. gingivalis could trigger or exacerbate AD pathogenesis.

Conserved perception of host and non-host signals via the a-pheromone receptor Ste3 in Colletotrichum graminicola

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.

Advanced glycation end products promote ROS production via PKC/p47 phox axis in skeletal muscle cells

Advanced glycation end products (AGEs) are risk factors for various diseases, including sarcopenia. One of the deleterious effects of AGEs is the induction of abnormal reactive oxygen species (ROS) production in skeletal muscle. However, the underlying mechanism remains poorly understood. Therefore, the aim of this study was to elucidate how AGEs induce ROS production in skeletal muscle cells. This study demonstrated that AGEs treatment promoted ROS production in myoblasts and myotubes while PKC inhibitor abolished ROS production by AGEs stimulation. Phosphorylation of p47 phox by kinases such as PKCα is required to form the Nox2 complex, which induces ROS production. In this study, AGEs treatment promoted the phosphorylation of PKCα and p47 phox in myoblasts and myotubes. Our findings suggest that AGEs promote ROS production through the phosphorylation of PKCα and p47 phox in skeletal muscle cells.

Oxidative stress-mediated protein sulfenylation in human diseases: Past, present, and future

Reactive Oxygen Species (ROS) refer to a variety of derivatives of molecular oxygen that play crucial roles in regulating a wide range of physiological and pathological processes. Excessive ROS levels can cause oxidative stress, leading to cellular damage and even cell demise. However, moderately elevated levels of ROS can mediate the oxidative post-translational modifications (oxPTMs) of redox-sensitive proteins, thereby affecting protein functions and regulating various cellular signaling pathways. Among the oxPTMs, ROS-induced reversible protein sulfenylation represents the initial form of cysteine oxidation for sensing redox signaling. In this review, we will summarize the discovery, chemical formation, and detection approaches of protein sulfenylation. In addition, we will highlight recent findings for the roles of protein sulfenylation in various diseases, including thrombotic disorders, diabetes, cardiovascular diseases, neurodegenerative diseases, and cancer.

Tumor necrosis factor alpha induces NOX2-dependent reactive oxygen species production in hypothalamic paraventricular nucleus neurons following angiotensin II infusion

There is evidence that tumor necrosis factor alpha (TNFα) influences autonomic processes coordinated within the hypothalamic paraventricular nucleus (PVN), however, the signaling mechanisms subserving TNFα's actions in this brain area are unclear. In non-neuronal cell types, TNFα has been shown to play an important role in canonical NADPH oxidase (NOX2)-mediated production of reactive oxygen species (ROS), molecules also known to be critically involved in hypertension. However, little is known about the role of TNFα in NOX2-dependent ROS production in the PVN within the context of hypertension. Using dual labeling immunoelectron microscopy and dihydroethidium (DHE) microfluorography, we provide structural and functional evidence for interactions between TNFα and NOX2 in the PVN. The TNFα type 1 receptor (TNFR1), the major mediator of TNFα signaling in the PVN, was commonly co-localized with the catalytic gp91phox subunit of NOX2 in postsynaptic sites of PVN neurons. Additionally, there was an increase in dual labeled dendritic profiles following fourteen-day slow-pressor angiotensin II (AngII) infusion. Using DHE microfluorography, it was also shown that TNFα application resulted in a NOX2-dependent increase in ROS in isolated PVN neurons projecting to the spinal cord. Further, TNFα-mediated ROS production was heightened after AngII infusion. The finding that TNFR1 and gp91phox are positioned for rapid interactions, particularly in PVN-spinal cord projection neurons, provides a molecular substrate by which inflammatory signaling and oxidative stress may jointly contribute to AngII hypertension.

NADPH oxidases in healthy white adipose tissue and in obesity: function, regulation, and clinical implications

Reactive oxygen species, when produced in a controlled manner, are physiological modulators of healthy white adipose tissue (WAT) expansion and metabolic function. By contrast, unbridled production of oxidants is associated with pathological WAT expansion and the establishment of metabolic dysfunctions, most notably insulin resistance and type 2 diabetes mellitus. NADPH oxidases (NOXs) produce oxidants in an orderly fashion and are present in adipocytes and in other diverse WAT-constituent cell types. Recent studies have established several links between aberrant NOX-derived oxidant production, adiposity, and metabolic homeostasis. The objective of this review is to highlight the physiological roles attributed to diverse NOX isoforms in healthy WAT and summarize current knowledge of the metabolic consequences related to perturbations in their adequate oxidant production. We detail WAT-related alterations in preclinical investigations conducted in NOX-deficient murine models. In addition, we review clinical studies that have employed NOX inhibitors and currently available data related to human NOX mutations in metabolic disturbances. Future investigations aimed at understanding the integration of NOX-derived oxidants in the regulation of the WAT cellular redox network are essential for designing successful redox-related precision therapies to curb obesity and attenuate obesity-associated metabolic pathologies.

Redox remodeling of central metabolism as a driving force for cellular protection, proliferation, differentiation, and dysfunction

The production of reactive oxygen species (ROS) is elevated via metabolic hyperactivation in response to a variety of stimuli such as growth factors and inflammation. Tolerable amounts of ROS moderately inactivate enzymes via oxidative modification, which can be reversed back to the native form in a redox-dependent manner. The excessive production of ROS, however, causes cell dysfunction and death. Redox-reactive enzymes are present in primary metabolic pathways such as glycolysis and the tricarboxylic acid cycle, and these act as floodgates for carbon flux. Oxidation of a specific form of cysteine inhibits glyceraldehyde-3-phosphate dehydrogenase, which is reversible, and causes an accumulation of upstream intermediary compounds that increases the flux of glucose-6-phosphate to the pentose phosphate pathway. These reactions increase the NADPH and ribose-5-phosphate that are available for reductive reactions and nucleotide synthesis, respectively. On the other hand, oxidative inactivation of mitochondrial aconitase increases citrate, which is then recruited to synthesize fatty acids in the cytoplasm. Decreases in the use of carbohydrate for ATP production can be compensated via amino acid catabolism, and this metabolic change makes nitrogen available for nucleic acid synthesis. Coupling of the urea cycle also converts nitrogen to urea and polyamine, the latter of which supports cell growth. This metabolic remodeling stimulates the proliferation of tumor cells and fibrosis in oxidatively damaged tissues. Oxidative modification of these enzymes is generally reversible in the early stages of oxidizing reactions, which suggests that early treatment with appropriate antioxidants promotes the maintenance of natural metabolism.

SIRT1/NOX1 pathway mediated ameliorative effects of rosmarinic acid in folic acid-induced renal injury

Background and purpose

Renal injury is a serious disorder that can be caused by some diseases or agents. Rosmarinic acid (RA) is a natural and safe compound with powerful antioxidant and anti-inflammatory properties. In this study, the ameliorative effects of RA were assayed in folic acid (FA)-induced renal injury by involving the SIRT1/NOX1 pathway.

Experimental approach

Thirty-six male C57/BL6 mice were divided into 6 groups (n = 6) including control, vehicle, FA, RA, FA + RA 50, and FA + RA 100. After 10 days, blood urea nitrogen (BUN), creatinine, and oxidative stress were measured. The expression of SIRT1 and NOX1 proteins was evaluated by western blot. Also, histopathological alterations were assayed by H&E and PAS staining methods.

Findings/Results

BUN and creatinine were significantly higher in the FA group compared to the control group; however, their levels decreased after RA treatment in both doses. A significant decrease was observed in swelling, necrosis, and desquamation of tubular epithelial cells in the FA + RA 50 and FA + RA 100 groups compared to the FA group. RA in the animals receiving FA increased SIRT1 expression and the levels of GSH and SOD compared to the FA group. RA in the animals receiving FA showed a significant decrease in NOX1 expression and MDA level compared to the FA group.

Conclusion and implications

The findings declared that the administration of RA has positive effects against renal damage induced by FA. The effect might result from involvement in the SIRT1/NOX1 pathway and thereby attenuation of oxidative stress.

4-Methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP) exposure induces hepatotoxicity and nephrotoxicity - role of oxidative stress, mitochondrial dysfunction and pathways of cytotoxicity

Objective

Bisphenol A (BPA) is a ubiquitous pollutant worldwide and 4-Methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP) is considered a major active metabolite of BPA with a wide range of potent toxicological properties. However, its adverse outcome pathway (AOP) on the hepatic and renal system has not yet been explored.

Methods

Hence, the current study evaluated its effect on cell survival, oxidative stress, and apoptosis. In addition, the influence of signalling pathways on cytotoxicity and ROS generating enzymes (NOX2 and XO) on oxidative stress was explored by siRNA knockdown experiments. Further, its molecular interaction with SOD, CAT, and HSA (molecular docking and dynamics) was evaluated and validated with spectroscopy (fluorescence and FTIR) based methods.

Results

The outcome indicates that MBP exposure dose dependently increased the cytotoxic response, oxidative stress, and apoptosis in both hepatocytes and kidney cells. Further, MAPK signalling pathways and oxidative stress influenced the overall cytotoxic response in both cells. In addition, the stimulatory (NOX2 and XO) and inhibitory (SOD and CAT) effects of MBP were observed, along with a robust interaction with HSA.

Conclusions

The overall observation illustrates that MBP exposure adversely impacts hepatic and renal cells through oxidative stress and relevant molecular pathways which may connect the missing links during risk assessment of BPA.

Regulation of and challenges in targeting NAD+ metabolism

Nicotinamide adenine dinucleotide, in its oxidized (NAD+) and reduced (NADH) forms, is a reduction-oxidation (redox) co-factor and substrate for signalling enzymes that have essential roles in metabolism. The recognition that NAD+ levels fall in response to stress and can be readily replenished through supplementation has fostered great interest in the potential benefits of increasing or restoring NAD+ levels in humans to prevent or delay diseases and degenerative processes. However, much about the biology of NAD+ and related molecules remains poorly understood. In this Review, we discuss the current knowledge of NAD+ metabolism, including limitations of, assumptions about and unappreciated factors that might influence the success or contribute to risks of NAD+ supplementation. We highlight several ongoing controversies in the field, and discuss the role of the microbiome in modulating the availability of NAD+ precursors such as nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN), the presence of multiple cellular compartments that have distinct pools of NAD+ and NADH, and non-canonical NAD+ and NADH degradation pathways. We conclude that a substantial investment in understanding the fundamental biology of NAD+, its detection and its metabolites in specific cells and cellular compartments is needed to support current translational efforts to safely boost NAD+ levels in humans.

NoxO1 Determines the Level of ROS Formation by the Nox1-Centered NADPH Oxidase

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.

Gastrodin Alleviates Angiotensin II-Induced Hypertension and Myocardial Apoptosis via Inhibition of the PRDX2/p53 Pathway In Vivo and In Vitro

Gastrodin, a highly potent compound found in the traditional Chinese medicine Gastrodia elata Blume, exhibits significant antihypertensive properties. However, its role and the mechanism behind its protective effects on hypertensive cardiac conditions are not well understood. This study aims to investigate the cardiac protective effects and underlying mechanisms of gastrodin in angiotensin II (Ang II)-induced hypertensive models, both in vivo and in vitro. Treatment with gastrodin significantly decreased blood pressure and the heart weight/tibial length (HW/TL) ratio and attenuated cardiac dysfunction and pathological damage in Ang II-infused C57BL/6 mice. RNA sequencing analysis (RNA-seq) revealed 697 up-regulated and 714 down-regulated transcripts, along with 1105 signaling pathways, in Ang II-infused C57BL/6 mice following gastrodin treatment, compared to Ang II-induced hypertensive mice. Furthermore, the analyses of the top 30 Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway indicated significant enrichment in apoptosis and the peroxiredoxin 2 (PRDX2)/p53 pathway. Consistently, gastrodin treatment significantly reduced myocardial apoptosis in both the cardiac tissues of Ang II-induced hypertensive mice and Ang II-stimulated H9c2 cells. Additionally, gastrodin treatment significantly decreased the protein levels of PRDX2, p53, cleaved caspase-3, cleaved caspase-9, and Bax/Bcl-2 ratio in the cardiac tissues of Ang II-infused mice and H9c2 cells stimulated with Ang II. In conclusion, gastrodin treatment can mitigate hypertension-induced myocardial apoptosis in hypertensive mice by inhibiting the PRDX2/p53 pathway.

TLR4 induced TRPM2 mediated neuropathic pain

Ion channels play an important role in mediating pain through signal transduction, regulation, and control of responses, particularly in neuropathic pain. Transient receptor potential channel superfamily plays an important role in cation permeability and cellular signaling. Transient receptor potential channel Melastatin 2 (TRPM2) subfamily regulates Ca2+ concentration in response to various chemicals and signals from the surrounding environment. TRPM2 has a role in several physiological functions such as cellular osmosis, temperature sensing, cellular proliferation, as well as the manifestation of many disease processes such as pain process, cancer, apoptosis, endothelial dysfunction, angiogenesis, renal and lung fibrosis, and cerebral ischemic stroke. Toll-like Receptor 4 (TLR4) is a critical initiator of the immune response to inflammatory stimuli, particularly those triggered by Lipopolysaccharide (LPS). It activates downstream pathways leading to the production of oxidative molecules and inflammatory cytokines, which are modulated by basal and store-operated calcium ion signaling. The cytokine production and release cause an imbalance of antioxidant enzymes and redox potential in the Endoplasmic Reticulum and mitochondria due to oxidative stress, which results from TLR-4 activation and consequently induces the production of inflammatory cytokines in neuronal cells, exacerbating the pain process. Very few studies have reported the role of TRPM2 and its association with Toll-like receptors in the context of neuropathic pain. However, the molecular mechanism underlying the interaction between TRPM2 and TLR-4 and the quantum of impact in acute and chronic neuropathic pain remains unclear. Understanding the link between TLR-4 and TRPM2 will provide more insights into pain regulation mechanisms for the development of new therapeutic molecules to address neuropathic pain.

Advanced glycation end products and reactive oxygen species: uncovering the potential role of ferroptosis in diabetic complications

Advanced glycation end products (AGEs) are a diverse range of compounds that are formed when free amino groups of proteins, lipids, and nucleic acids are carbonylated by reactive carbonyl species or glycosylated by reducing sugars. Hyperglycemia in patients with diabetes can cause an overabundance of AGEs. Excess AGEs are generally acknowledged as major contributing factors to the development of diabetic complications because of their ability to break down the extracellular matrix directly and initiate intracellular signaling pathways by binding to the receptor for advanced glycation end products (RAGE). Inflammation and oxidative stress are the two most well-defined pathophysiological states induced by the AGE-RAGE interaction. In addition to oxidative stress, AGEs can also inhibit antioxidative systems and disturb iron homeostasis, all of which may induce ferroptosis. Ferroptosis is a newly identified contributor to diabetic complications. This review outlines the formation of AGEs in individuals with diabetes, explores the oxidative damage resulting from downstream reactions of the AGE-RAGE axis, and proposes a novel connection between AGEs and the ferroptosis pathway. This study introduces the concept of a vicious cycle involving AGEs, oxidative stress, and ferroptosis in the development of diabetic complications.

Research Progress on the Mechanism, Monitoring, and Prevention of Cardiac Injury Caused by Antineoplastic Drugs-Anthracyclines

Anthracyclines represent a highly efficacious class of chemotherapeutic agents employed extensively in antitumor therapy. They are universally recognized for their potency in treating diverse malignancies, encompassing breast cancer, gastrointestinal tumors, and lymphomas. Nevertheless, the accumulation of anthracyclines within the body can lead to significant cardiac toxicity, adversely impacting both the survival rates and quality of life for tumor patients. This limitation somewhat restricts their clinical utilization. Determining how to monitor and mitigate their cardiotoxicity at an early stage has become an urgent clinical problem to be solved. Therefore, this paper reviews the mechanism of action, early monitoring, and strategies for the prevention of anthracycline-induced cardiotoxicity for clinical reference.

Amonafide-based H2O2-responsive theranostic prodrugs: Exploring the correlation between H2O2 level and anticancer efficacy

Leveraging the elevated hydrogen peroxide (H2O2) levels in cancer cells, H2O2-activated prodrugs have emerged as promising candidates for anticancer therapy. Notably, the efficacy of these prodrugs is influenced by the varying H2O2 levels across different cancer cell types. In this context, we have developed a novel H2O2-activated prodrug, PBE-AMF, which incorporates a phenylboronic ester (PBE) motif. Upon H2O2 exposure, PBE-AMF liberates the fluorescent and cytotoxic molecule amonafide (AMF), functioning as a theranostic agent. Our studies with PBE-AMF have demonstrated a positive correlation between intracellular H2O2 concentration and anticancer activity. The breast cancer cell line MDA-MB-231, characterized by high H2O2 content, showed the greatest susceptibility to this prodrug. Subsequently, we replaced the PBE structure with phenylboronic acid (PBA) to obtain the prodrug PBA-AMF, which exhibited enhanced stability, aqueous solubility, and tumor cell selectivity. This selectivity is attributed to its affinity for sialic acid, which is overexpressed on the surfaces of cancer cells. In vitro assays confirmed that PBA-AMF potently and selectively inhibited the proliferation of MDA-MB-231 cells, while sparing non-cancerous MCF-10A cells. Mechanistic investigations indicated that PBA-AMF impedes tumor proliferation by inhibiting DNA synthesis, reducing ATP levels, inducing apoptosis, and arresting the cell cycle. Our work broadens the range of small molecule H2O2-activated anticancer theranostic prodrugs, which are currently limited in number. We anticipate that the applications of PBA-AMF will extend to a wider spectrum of tumors and other diseases associated with increased H2O2 levels, thereby offering new horizons in cancer diagnostics and treatment.

Melatonin Alleviates Osteoarthritis by Regulating NADPH Oxidase 4-Induced Ferroptosis and Mitigating Mitochondrial Dysfunction

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.

Role of NADPH Oxidases in Stroke Recovery

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.

Epidemiology, Pathophysiology, and Current Treatment Strategies in Stroke

Both ischemic and hemorrhagic strokes are critical health issues and the incidence is on the rise. The rapid neurological degeneration that can occur with either type of stroke warrants prompt medical attention. In the article, we critically reviewed the literature examining their incidence, pathophysiology, and present treatment strategies. Clinical trials show conflicting findings, with ischemic strokes accounting for 87% of all strokes. Brain injury following an ischemic stroke results in cell death and necrosis, immune cells being the primary actors in the process of neuroinflammation. In order to develop neuroprotective drugs against ischemic stroke, detailed investigation of glutamate production and metabolism as well as downstream pathways controlled by glutamate receptors provides significant information on the underlying mechanisms. The permeability of the blood-brain barrier and the degradation of glutamine synthase are two potential mechanisms by which peritoneal dialysis accelerates brain-to-blood glutamate clearance and thus reduces glutamate levels in the brain after a stroke. Oxidative stress in an ischemic stroke disturbs the oxidant-antioxidant balance, which is particularly problematic for brain cells that are high in polyunsaturated fatty acids. Because of demographic factors like age, sex, race/ethnicity, and socioeconomic status, the incidence and prevalence of stroke differ across people and regions. For rapid diagnosis and treatment decisions, diagnostic imaging tools such as vascular imaging, CT, and MRI are essential. To aid in the recovery and lessen neurological impairments following a stroke, novel avenues of research are under investigation on neuroprotective medications that target inflammation, oxidative stress, and neuronal death.

NOX1-mediated oxidative stress induces chondrocyte ferroptosis by inhibiting the Nrf2/HO-1 pathway

Osteoarthritis (OA) is a common joint disease associated with the aging of the population, and it reduces the quality of life of patients. It is characterized by the destruction of articular cartilage and the secretion of inflammatory cytokines. Owing to the unclear pathogenesis of OA, current treatment methods have significant limitations. Oxidative stress has been revealed to play an important role in the development of OA. Our experiments indicated that the levels of GSH decreased and the level of MDA increased in chondrocytes, which induced ferroptosis in chondrocytes in OA. We also revealed that ferroptosis was the main mechanism of cartilage destruction caused by the addition of the ferroptosis activator erastin and the ferroptosis inhibitor ferrostatin-1. NOX1 is the main modulator of oxidative stress by increasing the generation of reactive oxidative species (ROS). We suppressed the expression of NOX1 in chondrocytes through cell transfection. The expression of collagen II and MMP13, and the secretion of IL-1β and TNF-α were reversed. An increase in the mitochondrial membrane potential and a decrease in the level of intracellular ROS indicate an improvement in oxidative damage. Additionally, we determined the effect of the Nrf2/HO-1 pathway on NOX1-mediated chondrocyte injury. We found that NOX1 inhibited the expression of Nrf2/HO-1, but the activation of Nrf2 improved the oxidative damage to chondrocytes in vivo and vitro. This study revealed that NOX1-mediated oxidative stress induces chondrocyte ferroptosis by inhibiting the Nrf2/HO-1 pathway. Our findings contribute to revealing the pathogenesis of OA, providing targets for drug design and optimizing the clinical treatment of OA.

Role of mitochondria in inflammatory lung diseases

Mitochondria play a significant and varied role in inflammatory lung disorders. Mitochondria, known as the powerhouse of the cell because of their role in producing energy, are now recognized as crucial regulators of inflammation and immunological responses. Asthma, chronic obstructive pulmonary disease, and acute respiratory distress syndrome are characterized by complex interactions between immune cells, inflammatory substances, and tissue damage. Dysfunctional mitochondria can increase the generation of reactive oxygen species (ROS), triggering inflammatory pathways. Moreover, mitochondrial failure impacts cellular signaling, which in turn affects the expression of molecules that promote inflammation. In addition, mitochondria have a crucial role in controlling the behavior of immune cells, such as their activation and differentiation, which is essential in the development of inflammatory lung diseases. Their dynamic behavior, encompassing fusion, fission, and mitophagy, also impacts cellular responses to inflammation and oxidative stress. Gaining a comprehensive understanding of the intricate correlation between mitochondria and lung inflammation is essential in order to develop accurate treatment strategies. Targeting ROS generation, dynamics, and mitochondrial function may offer novel approaches to treating inflammatory lung diseases while minimizing tissue damage. Additional investigation into the precise contributions of mitochondria to lung inflammation will provide significant knowledge regarding disease mechanisms and potential therapeutic approaches. This review will focus on how mitochondria in the lung regulate these processes and their involvement in acute and chronic lung diseases.

Targeting and activation of macrophages in leishmaniasis. A focus on iron oxide nanoparticles

Macrophages play a pivotal role as host cells for Leishmania parasites, displaying a notable functional adaptability ranging from the proinflammatory, leishmanicidal M1 phenotype to the anti-inflammatory, parasite-permissive M2 phenotype. While macrophages can potentially eradicate amastigotes through appropriate activation, Leishmania employs diverse strategies to thwart this activation and redirect macrophages toward an M2 phenotype, facilitating its survival and replication. Additionally, a competition for iron between the two entities exits, as iron is vital for both and is also implicated in macrophage defensive oxidative mechanisms and modulation of their phenotype. This review explores the intricate interplay between macrophages, Leishmania, and iron. We focus the attention on the potential of iron oxide nanoparticles (IONPs) as a sort of immunotherapy to treat some leishmaniasis forms by reprogramming Leishmania-permissive M2 macrophages into antimicrobial M1 macrophages. Through the specific targeting of iron in macrophages, the use of IONPs emerges as a promising strategy to finely tune the parasite-host interaction, endowing macrophages with an augmented antimicrobial arsenal capable of efficiently eliminating these intrusive microbes.