Physiological Signaling Functions of Reactive Oxygen Species in Stem Cells: From Flies to Man

Reactivity of trinuclear ruthenium acetates with nitrite and nitric oxide ligands in aqueous media

The chemical reactivity of nitrosyl- and nitrite-coordinated compounds in an aqueous environment is a vital part of understanding the action of these compounds as potential nitric oxide-releasing molecules (NORMs). This work reports the behaviour of the [Ru3O(CH3COO)6(py)2NO2] (1) complex, which is an isomeric mixture of nitrite-N and nitrite-O, and the nitrosyl complex [Ru3O(CH3COO)6(py)2NO]PF6 (2) in aqueous medium with and without light irradiation. NO release under light irradiation was detected through chronoamperometry, which showed that nitrite complex 1 produces NO but is less effective than nitrosyl complex 2. This difference is due to the mechanism of NO production by complex 1, which depends on the nitrite-O isomer, present in minor proportion in the synthetic sample, as shown by computational and NMR data. The reactivity of these compounds in the dark was investigated under various pH values. The nitrite complex 1 had the coordinated nitrite converted to NO+, with a pK = 4.2. NO+ was readily released, yielding the solvate species [Ru3O(CH3COO)6(py)2S]+. For the nitrosyl complex 2, two successive nucleophilic attacks by hydroxide ions were observed producing the [Ru3O(CH3COO)6(py)2HNO2] (3) and [Ru3O(CH3COO)6(py)2NO2]- (4) compounds, with pK values of 9.8 and 12.3, respectively. In buffered solutions (TRIS.HCl and PBS), the kinetic trace for the conversion of 2 to 3 suggested an induction period followed by the complete conversion to [Ru3O(CH3COO)6(py)2HNO2] at pH values where the nitrosyl [Ru3O(CH3COO)6(py)2NO]+ should be the major species. Based on these observations, our data suggest a sequence of steps in which compound 3 accumulates and then, with the aid of the buffer components, increases the rate of its own formation.

Gene network analysis combined with preclinical studies to identify and elucidate the mechanism of action of novel irreversible Keap1 inhibitor for Parkinson's disease

The cysteine residues of Keap1 such as C151, C273, and C288 are critical for its repressor activity on Nrf2. However, to date, no molecules have been identified to covalently modify all three cysteine residues for Nrf2 activation. Hence, in this study, our goal is to discover new Keap1 covalent inhibitors that can undergo a Michael addition with all three cysteine residues. The Keap1's intervening region was modeled using Modeller v10.4. Covalent docking and binding free energy were calculated using CovDock. Molecular dynamics (MD) was performed using Desmond. Various in-vitro assays were carried out to confirm the neuroprotective effects of the hit molecule in 6-OHDA-treated SH-SY5Y cells. Further, the best hit was evaluated in vivo for its ability to improve rotenone-induced postural instability and cognitive impairment in male rats. Finally, network pharmacology was used to summarize the complete molecular mechanism of the hit molecule. Chalcone and plumbagin were found to form the necessary covalent bonds with all three cysteine residues. However, MD analysis indicated that the binding of plumbagin is more stable than chalcone. Plumbagin displayed neuroprotective effects in 6-OHDA-treated SH-SY5Y cells at concentrations 0.01 and 0.1 μM. Plumbagin at 0.1 µM had positive effects on reactive oxygen species formation and glutathione levels. Plumbagin also improved postural instability and cognitive impairment in rotenone-treated male rats. Our network analysis indicated that plumbagin could also improve dopamine signaling. Additionally, plumbagin could exhibit anti-oxidant and anti-inflammatory activity through the activation of Nrf2. Cumulatively, our study suggests that plumbagin is a novel Keap1 covalent inhibitor for Nrf2-mediated neuroprotection in PD.

Electrochemical detection of superoxide anion in living systems: Recent trends and clinical implications

Superoxide plays a significant role in maintaining physiological states of living systems, with major roles in eradicating invading microorganisms and in cell signaling. It is regulated intricately by the enzyme superoxide dismutase (SOD), and when not properly regulated it can lead to cascade biological pathways with severe and irreversible damage to biofilms, tissue, and organs, being linked with many neurodegenerative diseases, atherosclerotic and cardiovascular diseases. Therefore, superoxide anion (O2•-) detection has a tremendous potential in clinical diagnostics to assess oxidative stress in living cells. This comprehensive review aims to explore, discuss, and analyze recent trends in the electrochemical detection of O2•- in living systems, focusing not only on the recognition mechanism for in vitro assays (living cell cultures/tissues) but also on the importance of the electrode design and operational parameters for in vivo measurements (implantable sensors). By analyzing current in vitro/in vivo electrochemical strategies we gather information that is helpful to overcome existing limitations in the dynamic monitoring of O2•-, and further improve electrochemical strategies that can be adopted and applied to prevent its negative effect, with an insight into the pathophysiology of neurodegenerative disorders and even cellular malignancies that derive from its accumulation in living systems.

Unveiling the key toxicity indicators and mechanisms on phytotoxicity of cerium dioxide nanoparticles in rice (Oryza sativa)

The splendid varieties of cerium dioxide nanoparticles (nCeO2) and their diverse applications stimulated their uncontrolled discharge in the biological system. So, in the present study, Oryza sativa was adopted as a model plant and its phytotoxic effects were studied with neutrally charged, >12 nm sized spherical nCeO2 (0 g/L, 2 g/L, 4 g/L, 6 g/L, 8 g/L & 10 g/L). The studies were also conducted with bulk ceria counterparts and compared. This work is focused on a systematic approach to evaluate the phytotoxicity of nCeO2 in Oryza sativa, in terms of key toxicity indicators, nanoparticle uptake, and aggregation mechanisms. With this study, we propose a new sensing approach with non-fluorescent/non-chemiluminescent molecules for the detection of the generation of reactive oxygen species (ROS) to study the mechanism of phytotoxicity. An aggregation mechanism was also detailed to explicate the ROS-induced phytotoxicity. The study demonstrates that an increase in the production of ROS causes progressive cellular damage in Oryza sativa only at lower exposure level concentrations of nCeO2 (≥4 g/L). Our findings revealed that the key toxicity indicators and the actual nanoparticle uptake and aggregation mechanisms will decide the extent of phytotoxicity of nCeO2 in Oryza sativa.

Protein-responsive gut hormone tachykinin directs food choice and impacts lifespan

Animals select food based on hungers that reflect dynamic macronutrient needs, but the hormonal mechanisms underlying nutrient-specific appetite regulation remain poorly defined. Here, we identify tachykinin (Tk) as a protein-responsive gut hormone in Drosophila and female mice, regulated by conserved environmental and nutrient-sensing mechanisms. Protein intake activates Tk-expressing enteroendocrine cells (EECs), driving the release of gut Tk through mechanisms involving target of rapamycin (TOR) and transient receptor potential A1 (TrpA1). In flies, we delineate a pathway by which gut Tk controls selective appetite and sleep after protein ingestion, mediated by glucagon-like adipokinetic hormone (AKH) signalling to neurons and adipose tissue. This mechanism suppresses protein appetite, promotes sugar hunger and modulates wakefulness to align behaviour with nutritional needs. Inhibiting protein-responsive gut Tk prolongs lifespan through AKH, revealing a role for nutrient-dependent gut hormone signalling in longevity. Our results provide a framework for understanding EEC-derived nutrient-specific satiety signals and the role of gut hormones in regulating food choice, sleep and lifespan.

The Clinical Utility and Plausibility of Oxidative and Antioxidant Variables in Chronic and End-Stage Kidney Disease: A Review of the Literature

Oxidative stress (OS) is caused by an imbalance between the production of reactive oxygen species (ROS) in cells and tissues and the ability of the biological system to detoxify these products. In chronic kidney disease (CKD), OS contributes to deterioration of kidney function and disease progression. In patients with end-stage kidney disease undergoing hemodialysis or peritoneal dialysis, OS is further increased and associated with adverse clinical outcomes, including deterioration and subsequent loss of residual renal function, atherosclerosis, hypertension, cardiovascular disease and death. However, currently, there is no consensus or guidelines for the diagnosis and treatment of OS in these patients. Herein, we aim to present the existing data regarding biomarkers of OS, pro-oxidants (oxidized albumin, advanced oxidation protein products, xanthine oxidase/dehydrogenase, nitrite/nitrate, malondialdehyde) and antioxidants (superoxide dismutase, catalase, vitamin E, total antioxidant capacity, N-acetylcysteine) that are most clinically relevant and have been more extensively studied in patients with chronic kidney disease, aiming to provide a clearer understanding of this complex area.

Redox signaling modulates axonal microtubule organization and induces a specific phosphorylation signature of microtubule-regulating proteins

Many life processes are regulated by physiological redox signaling, but excessive oxidative stress can damage biomolecules and contribute to disease. Neuronal microtubules are critically involved in axon homeostasis, regulation of axonal transport, and neurodegenerative processes. However, whether and how physiological redox signaling affects axonal microtubules is largely unknown. Using live cell imaging and super-resolution microscopy, we show that subtoxic concentrations of the central redox metabolite hydrogen peroxide increase axonal microtubule dynamics, alter the structure of the axonal microtubule array, and affect the efficiency of axonal transport. We report that the mitochondria-targeting antioxidant SkQ1 and the microtubule stabilizer EpoD abolish the increase in microtubule dynamics. We found that hydrogen peroxide specifically modulates the phosphorylation state of microtubule-regulating proteins, which differs from arsenite as an alternative stress inducer, and induces a largely non-overlapping phosphorylation pattern of MAP1B as a main target. Cell-wide phosphoproteome analysis revealed signaling pathways that are inversely activated by hydrogen peroxide and arsenite. In particular, hydrogen peroxide treatment was associated with kinases that suppress apoptosis and regulate brain metabolism (PRKDC, CK2, PDKs), suggesting that these pathways play a central role in physiological redox signaling and modulation of axonal microtubule organization. The results suggest that the redox metabolite and second messenger hydrogen peroxide induces rapid and local reorganization of the microtubule array in response to mitochondrial activity or as a messenger from neighboring cells by activating specific signaling cascades.

The Complexities of Interspecies Somatic Cell Nuclear Transfer: From Biological and Molecular Insights to Future Perspectives

For nearly three decades, interspecies somatic cell nuclear transfer (iSCNT) has been explored as a potential tool for cloning, regenerative medicine, and wildlife conservation. However, developmental inefficiencies remain a major challenge, largely due to persistent barriers in nucleocytoplasmic transport, mitonuclear communication, and epigenome crosstalk. This review synthesized peer-reviewed English articles from PubMed, Web of Science, and Scopus, spanning nearly three decades, using relevant keywords to explore the molecular mechanisms underlying iSCNT inefficiencies and potential improvement strategies. We highlight recent findings deepening the understanding of interspecies barriers in iSCNT, emphasizing their interconnected complexities, including the following: (1) nucleocytoplasmic incompatibility may disrupt nuclear pore complex (NPC) assembly and maturation, impairing the nuclear transport of essential transcription factors (TFs), embryonic genome activation (EGA), and nuclear reprogramming; (2) mitonuclear incompatibility could lead to nuclear and mitochondrial DNA (nDNA-mtDNA) mismatches, affecting electron transport chain (ETC) assembly, oxidative phosphorylation, and energy metabolism; (3) these interrelated incompatibilities can further influence epigenetic regulation, potentially leading to incomplete epigenetic reprogramming in iSCNT embryos. Addressing these challenges requires a multifaceted, species-specific approach that balances multiple incompatibilities rather than isolating a single factor. Gaining insight into the molecular interactions between the donor nucleus and recipient cytoplast, coupled with optimizing strategies tailored to specific pairings, could significantly enhance iSCNT efficiency, ultimately transforming experimental breakthroughs into real-world applications in reproductive biotechnology, regenerative medicine, and species conservation.

Moderate levels of folic acid benefit outcomes for cilia based neural tube defects

Folic acid (FA) supplementation is a potent tool to reduce devastating birth defects known as neural tube defects (NTDs). Though effective, questions remain how FA achieves its protective effect and which gene mutations are sensitive to folic acid levels. We explore the relationship between FA dosage and NTD rates using NTD mouse models. We demonstrate that NTD rates in mouse models harboring mutations in cilia genes depend on FA dosage. Cilia mutant mouse models demonstrate reductions in NTD rates when exposed to moderate levels of FA that are not observed at higher fortified levels of FA. This trend continues with a moderate level of FA being beneficial for primary and motile cilia formation. We present a mechanism through which fortified FA levels reduce basal levels of reactive oxygen species (ROS) which in turn reduces ROS-sensitive GTPase activity required for ciliogenesis. Our data indicates that genes involved in cilia formation and function represent a FA sensitive category of mutations and a possible avenue for further reducing NTD and ciliopathy incidences.

GsMTx-4 venom toxin antagonizes biophysical modulation of metastatic traits in human osteosarcoma cells

Despite their genetic diversity, metastatic cells converge on similar physical constraints during tumor progression. At the nanoscale, these forces can induce substantial molecular deformations, altering the structure and behavior of cancer cells. To address the challenges of osteosarcoma (OS), a highly aggressive cancer, we explored the mechanobiology of OS cells, in vitro. Using uniaxial-stretching technology, we examined the biophysical modulation of metastatic traits in SAOS-2, U-2 OS, and non-tumorigenic hFOB cells. Changes in cell morphology were quantified using confocal and fluorescence microscopy. To elucidate the molecular mechanisms that translate biomechanical alterations into biochemical responses, we employed Western blotting, real-time quantitative RT-PCR, reactive oxygen species ROS assay, and the mechanosensitive channel blocker Grammostola MechanoToxin4 (GsMTx-4). Our study reveals that mechanical stimulation uniquely affects OS cells, increasing nuclear size and altering the N/C ratio. We found that mechanosensitive (MS) channels are activated, leading to ROS accumulation, Src protein modulation, and histone H3 acetylation. These changes influence OS cell motility and adhesion but not proliferation. Importantly, mechanical preconditioning differentially impacts doxorubicin resistance, correlating with the Src-H3 acetylation axis. This study underscores the critical role of MS channels in OS cells and highlights the importance of mechanobiology in identifying molecular pathways that traditional biochemical approaches may not reveal. Notably, the GsMTx-4 venom peptide effectively countered mechanically induced responses, particularly by inhibiting OS cell migration, without harming healthy cells. Thus, suggesting its potential as a promising therapeutic agent for targeting osteosarcoma metastasis.

Crosstalk Between Autophagy and Oxidative Stress in Hematological Malignancies: Mechanisms, Implications, and Therapeutic Potential

Autophagy is a fundamental cellular process that maintains homeostasis by degrading damaged components and regulating stress responses. It plays a crucial role in cancer biology, including tumor progression, metastasis, and therapeutic resistance. Oxidative stress, similarly, is key to maintaining cellular balance by regulating oxidants and antioxidants, with its disruption leading to molecular damage. The interplay between autophagy and oxidative stress is particularly significant, as reactive oxygen species (ROS) act as both inducers and by-products of autophagy. While autophagy can function as a tumor suppressor in early cancer stages, it often shifts to a pro-tumorigenic role in advanced disease, aiding cancer cell survival under adverse conditions such as hypoxia and nutrient deprivation. This dual role is mediated by several signaling pathways, including PI3K/AKT/mTOR, AMPK, and HIF-1α, which coordinate the balance between autophagic activity and ROS production. In this review, we explore the mechanisms by which autophagy and oxidative stress interact across different hematological malignancies. We discuss how oxidative stress triggers autophagy, creating a feedback loop that promotes tumor survival, and how autophagic dysregulation leads to increased ROS accumulation, exacerbating tumorigenesis. We also examine the therapeutic implications of targeting the autophagy-oxidative stress axis in cancer. Current strategies involve modulating autophagy through specific inhibitors, enhancing ROS levels with pro-oxidant compounds, and combining these approaches with conventional therapies to overcome drug resistance. Understanding the complex relationship between autophagy and oxidative stress provides critical insights into novel therapeutic strategies aimed at improving cancer treatment outcomes.

UGP2, a novel target gene of TP53, inhibits endothelial cells apoptosis and atherosclerosis

The dysfunction of the endothelial lining in lesion-prone areas of the arterial vasculature significantly contributes to the pathobiology of atherosclerotic cardiovascular disease. Recent studies suggested that UDP-glucose pyrophosphorylase 2 (UGP2) plays a role in cell proliferation and survival. This study investigates the anti-apoptotic and anti-atherogenic effects of UGP2 both in vitro and in vivo. We explored the effects and mechanisms of UGP2 on apoptosis in endothelial cells using flow cytometry and Western blot analysis. Additionally, we evaluate apoptosis levels in atherosclerotic lesions with ldlr-/- ugp2+/- mice. Microarray analysis revealed reduced UGP2 expression in human atherosclerotic plaques. In vitro experiments demonstrated that TP53 interacts with the promoter region of the UGP2 gene, upregulating UGP2 expression. Enhanced UGP2 expression led to decreased reactive oxygen species (ROS) levels, reduced Cleaved caspase-3 expression, and lower apoptosis levels in endothelial cells. The anti-apoptotic effects of UGP2 were significantly diminished by H2O2. In vivo, UGP2 deficiency in ldlr-/- mice fed a Western high-fat diet promoted atherosclerosis, increased ROS levels, and elevated Cleaved caspase-3 expression and apoptosis in atherosclerotic lesions. Our findings identify UGP2 as a novel TP53 target gene that contributes to anti-apoptotic effects by regulating ROS homeostasis via a non-canonical pathway. UGP2 represents a potential therapeutic target for ameliorating atherosclerosis-related diseases.

Unveiling the Role of Selenium in Child Development: Impacts on Growth, Neurodevelopment and Immunity

Selenium (Se) is a vital trace element for children, playing a crucial role in numerous physiological processes, including antioxidant defense, immune regulation, thyroid function, and bone metabolism. Emerging evidence highlights its potential impact on child development and growth while also underscoring the complexity of its mechanisms and the global variations in Se intake. The aim of this review is to comprehensively elucidate the significance of Se in various biological processes within the human body, with a focus on its role in child development and growth; its biochemical effects on the nervous system, thyroid function, immune system, and bone tissue; and the implications of Se deficiency and toxicity. This review integrates findings from experimental models, epidemiological studies, and clinical trials to explore Se's role in neurodevelopment, growth regulation, and immune competence in children. Selenoproteins, which regulate oxidative stress and thyroid hormone and bone metabolism, are essential for normal growth and cognitive development in children. Se deficiency and toxicity has been linked to impaired immune function, growth retardation, and decreased immune function. The findings underscore Se's influence on various biological pathways that are critical for healthy child development and its broader importance for child health. Public health strategies aimed at optimizing selenium intake may play a pivotal role in improving pediatric health outcomes worldwide.

Light assisted modulation of stem cell function and secretome production: a systematic review on current status and new avenues for regenerative medicine

Stem cells (SC) based therapies are proving to be the mainstay of regenerative medicine. Despite the significant potential, direct grafting or implantation of SCs for regenerative therapy encounters various translational roadblocks such as paucity of implantable cells, decreased potency, cell death post-implantation, cell damage caused by the pre-existing inflammation and immune rejection. Hence, an emerging avenue is cell-free approach; use of SC secretome. Although priming approaches based on pharmacological molecules/chemicals, cytokines and growth factors are being explored to elicit enhanced secretome production, the potential concerns include the need for continuous replenishment and potential chemical contamination during secretome isolation. To alleviate these concerns, various non-pharmacological approaches for invigorating SCs are also being investigated and among these, use of photobiomodulation (PBM) has garnered considerable interest. Notwithstanding the positive outcomes, standardized parameters are yet to be established for reproducible results. Moreover, the mechanisms of PBM based SC stimulation and secretome production are poorly elucidated and significant knowledge gaps exist on influence of cell type, culture conditions on PBM. This review aims to provide insight into the current status of this emerging field emphasizing on novel avenues and potential challenges for clinical translation. We also summarize the studies on PBM based proliferation, differentiation and secretome production according to SC cell type and culture conditions. Further, as a fixed PBM based protocol for SC proliferation, differentiation and secretome is lacking, the knowledge on functional targets and pathways in PBM based SC stimulation needs upgradation. Consequently, putative mechanisms for PBM based SC secretome have been proposed.

Airway Epithelium-derived CXCL14 Promotes Eosinophil Accumulation in Allergic Airway Inflammation

CXCL14 (C-X-C motif chemokine ligand 14) is expressed in the airway epithelial cells of patients with asthma. However, the mechanisms of CXCL14 secretion and its effects on asthma pathogenesis remain unclear. Here, we investigated the role of CXCL14 in allergic airway inflammation and its effects on eosinophil infiltration. Our findings showed that Alternaria alternata, a major environmental allergen, stimulated CXCL14 secretion from airway epithelial cells via reactive oxygen species generated in mitochondrial oxidative phosphorylation complexes, especially in oxidative phosphorylation complex II. In vivo, in a mouse model of allergic airway inflammation, intranasal administration of anti-CXCL14 antibody suppressed eosinophil and dendritic cell infiltration into the airways and goblet cell hyperplasia. In vitro, in human eosinophil-like cells, CXCL14 promoted cell migration through CXCR4 binding. Eosinophil CXCR4 expression was upregulated by Alternaria stimulation via reactive oxygen species production. These findings suggest that the cross-talk between Alternaria-stimulated airway epithelial CXCL14 secretion and eosinophil CXCR4 upregulation plays an important role in eosinophil infiltration into the lungs during allergic airway inflammation. In summary, this study demonstrates that CXCL14 could be a therapeutic target for allergic airway inflammation.

Review of cancer cell volatile organic compounds: their metabolism and evolution

Cancer is ranked as the top cause of premature mortality. Volatile organic compounds (VOCs) are produced from catalytic peroxidation by reactive oxygen species (ROS) and have become a highly attractive non-invasive cancer screening approach. For future clinical applications, however, the correlation between cancer hallmarks and cancer-specific VOCs requires further study. This review discusses and compares cellular metabolism, signal transduction as well as mitochondrial metabolite translocation in view of cancer evolution and the basic biology of VOCs production. Certain cancerous characteristics as well as the origin of the ROS removal system date back to procaryotes and early eukaryotes and share commonalities with non-cancerous proliferative cells. This calls for future studies on metabolic cross talks and regulation of the VOCs production pathway.

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.

Diabetes and the associated complications: The role of antioxidants in diabetes therapy and care

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by high blood sugar levels (hyperglycemia). Poorly managed diabetes can lead to complications affecting multiple organ systems. Antioxidants play a crucial role in reducing oxidative stress caused by reactive oxygen species (ROS), primarily triggered by uncontrolled high blood sugar levels in diabetes. Antioxidants like vitamin C, E, selenium, and alpha-lipoic acid, when used as supplements, have shown promise in reducing oxidative stress markers and improving antioxidant status in laboratory and animal studies and diabetic patients. Antioxidant supplementation may help reduce the risk of diabetic complications such as neuropathy, nephropathy, retinopathy, and cardiovascular disease. Additionally, antioxidants also have anti-inflammatory properties, which could be beneficial in reducing inflammation associated with diabetes. Antioxidant supplementation has been shown to enhance endothelial function, insulin sensitivity, and glucose metabolism, thereby aiding in glycemic control and overall diabetic management. Combining antioxidants with certain medications may have therapeutic benefits, such as effectively neutralizing free radicals and enhancing the regulation of antioxidant defense systems. This review presents an update on diabetes, the sources of free radical generation, the body's natural defense mechanisms, the clinical evidence regarding using antioxidants in managing diabetic complications, and the potential new therapeutic approaches. Overall, antioxidant supplementation may offer some benefits in managing diabetic complications. However, further studies are needed to understand the mechanisms of action, determine the optimal supplementation, explore potential interactions with other medications, and conduct long-term studies to establish the possible use of antioxidants for optimal benefits in diabetes care.

A shift in chromatin binding of phosphorylated p38 precedes transcriptional changes upon oxidative stress

P38 mitogen-activated protein kinases are key in the regulation of the cellular response to stressors. P38 is known to regulate transcription, mRNA processing, stability, and translation. The transcriptional changes mediated by phosphorylated p38 (P-p38) in response to extracellular stimuli have been thoroughly analyzed in many tissues and organisms. However, the genomic localization of chromatin-associated P-p38 remains poorly understood. Here, we analyze the chromatin binding of activated P-p38 and its role in the response to reactive oxygen species (ROS) in Drosophila S2 cells. We found that P-p38 is already bound to chromatin in basal conditions. After ROS exposure, chromatin-associated P-p38 relocates towards genes involved in the recovery process. Our findings highlight the role of P-p38 dynamic chromatin binding in orchestrating gene expression responses to oxidative stress.

Drosophila: An Important Model for Exploring the Pathways of Inflammatory Bowel Disease (IBD) in the Intestinal Tract

Inflammatory bowel disease (IBD) is a chronic and recurring lifelong condition, the exact etiology of which remains obscure. However, an increasing corpus of research underscores the pivotal role of cellular signaling pathways in both the instigation and management of intestinal inflammation. Drosophila, owing to its prodigious offspring, abbreviated life cycle, and the conservation of signaling pathways with mammals, among other advantages, has become a model organism for IBD research. This review will expound on the feasibility of utilizing Drosophila as an IBD model, comparing its intestinal architecture with that of mammals, its inflammatory responses, and signaling pathways. Furthermore, it will deliberate on the role of natural products across various biological models of IBD pathways, elucidating the viability of fruit flies as IBD models and the modus operandi of cellular signaling pathways in the context of IBD.

New Emerging Therapeutic Strategies Based on Manipulation of the Redox Regulation Against Therapy Resistance in Cancer

Background: Resistance to standard therapeutic methods, including chemotherapy, immunotherapy, and targeted therapy, remains a critical challenge in effective cancer treatment. Redox homeostasis modification has emerged as a promising approach to address medication resistance. Objective: This review aims to explore the mechanisms of redox alterations and signaling pathways contributing to treatment resistance in cancer. Methods: In this study, a comprehensive review of the molecular mechanisms underlying drug resistance governed by redox signaling was conducted. Emphasis was placed on understanding how tumor cells manage increased reactive oxygen species (ROS) levels through upregulated antioxidant systems, enabling resistance across multiple therapeutic pathways. Results: Key mechanisms identified include alterations in drug efflux, target modifications, metabolic changes, enhanced DNA damage repair, stemness preservation, and tumor microenvironment remodeling. These pathways collectively facilitate tumor cells' adaptive response and resistance to various cancer treatments. Conclusion: Developing a detailed understanding of the interrelationships between these redox-regulated mechanisms and therapeutic resistance holds potential to improve treatment effectiveness, offering valuable insights for both fundamental and clinical cancer research. Antioxid. Redox Signal. 00, 000-000.

Ovatodiolide inhibits endometrial cancer stemness via reactive oxygen species-mediated DNA damage and cell cycle arrest

Endometrial cancer (EC) is a common gynecological cancer worldwide, often associated with a poor prognosis after recurrence or metastasis. Ovatodiolide (OVA) is a macrocyclic diterpenoid derived from Anisomeles indica that shows anticancer effects in various malignancies. This study aimed to evaluate the cytotoxic effects of OVA on EC cell proliferation and cancer stem cell (CSC) activity and explore its underlying molecular mechanisms. OVA treatment dose-dependently reduced the viability and colony formation of three EC cell lines (AN3CA, HEC-1A, and EMC6). It induced G2/M phase cell cycle arrest, associated with decreased cell division cycle 25C (CDC25C) expression and reduced activation of cyclin-dependent kinases 1 (CDK1) and 2 (CDK2). OVA also increased reactive oxygen species (ROS) production and DNA damage, activating the DNA damage-sensitive cell cycle checkpoint kinases 1 (CHK1) and 2 (CHK2) and upregulating the DNA damage marker γ-H2A.X variant histone (H2AX). It also suppressed the activation of mechanistic target of rapamycin kinase (mTOR) and nuclear factor kappa B (NF-κB) and downregulated glutathione peroxidase 1 (GPX1), an antioxidant enzyme counteracting oxidative stress. Moreover, OVA reduced the self-renewal capacity of CSCs, reducing the expression of key stemness proteins Nanog homeobox (NANOG) and octamer-binding transcription factor 4 (OCT4). The ROS inhibitor N-acetylcysteine attenuated the anti-proliferative and anti-CSC effects of OVA. Our findings suggest that OVA acts via ROS generation, leading to oxidative stress and DNA damage, culminating in cell cycle arrest and the suppression of CSC activity in EC. Therefore, OVA is a promising therapeutic agent for EC, either as a standalone treatment or an adjunct to existing therapies.

25-Hydroxycholesterol induces oxidative stress, leading to apoptosis and ferroptosis in extravillous trophoblasts

25-hydroxycholesterol (25HC) is an oxysterol derived from cholesterol and plays a role in various cellular processes, such as lipid metabolism, inflammatory responses, and cell survival. Extravillous trophoblasts (EVTs) are a major cell type found in the placenta, which are highly energetic cells with proliferative and invasive properties. EVT dysfunction can lead to pregnancy complications, including preeclampsia and intrauterine growth restriction. This study investigated the effects and underlying mechanisms of action of 25HC on EVT proliferation. Swan 71 cells, an EVT cell line, were treated with different concentrations of 25HC. Next, cell proliferation was assessed. The mitochondrial reactive oxygen species (mtROS), mitochondrial membrane potentials (MMPs), lipid peroxidation (LPO), and glutathione (GSH) levels were measured. Apoptosis, ferroptosis, and autophagy were evaluated by western blotting and flow cytometry. The results revealed that 25HC significantly inhibited proliferation and decreased the metabolic activity of EVTs. Moreover, 25HC caused oxidative stress by altering mtROS, LPO, MMPs, and GSH levels. Additionally, 25HC induces apoptosis, ferroptosis, and autophagy through the modulation of relevant protein levels. Interestingly, pretreatment with Z-VAD-FMK, an apoptosis inhibitor, and ferrostatin-1, a ferroptosis inhibitor, partially restored the effects of 25HC on cell proliferation, oxidative stress, and cell death. In summary, our findings suggest that 25HC treatment inhibits EVT proliferation and triggers apoptosis, ferroptosis, and autophagy, which are attributable to oxidative stress.

Modulatory Effects of 830 nm on Diabetic Wounded Fibroblast Cells: An In Vitro Study on Inflammatory Cytokines

Background:After skin damage, a complicated set of processes occur for epidermal and dermal wound healing. This process is hindered under diabetic conditions, resulting in nonhealing diabetic ulcers. In diabetes there is an increase in inflammation and proinflammatory cytokines. Modulating cells using photobiomodulation (PBM) may have an effect on inflammation and cell viability, which are crucial for the healing of wounds. Objective: This study explored the impact of PBM in the near-infrared spectrum (830 nm; 5 J/cm2) on inflammation in diabetic wound healing. Materials and Methods: Five cell models, namely normal, wounded, diabetic, diabetic wounded, and wounded with d-galactose were used. Cell morphology and migration rate were assessed, while cellular response measures included viability (Trypan blue and adenosine triphosphate), apoptosis (annexin-V/PI), proinflammatory cytokines interleukin-6, tumor necrosis factor-alpha (TNF-α), and cyclooxygenase-2, nuclear translocation of nuclear factor kappa B (NF-κB), and gene expression of advanced glycation end product receptor (AGER). Results: PBM resulted in increased levels of TNF-α, supported by activation of NF-κB. PBM stimulated translocation of NF-κB and upregulation of AGER. Conclusions: PBM modulates diabetic wound healing in vitro at 830 nm through stimulated NF-κB signaling activated by TNF-α.

Photoprotective Effect of Ultrasonic-Assisted Ethanol Extract from Sargassum horneri on UVB-Exposed HaCaT Keratinocytes

The present study investigated the photoprotective effect of the ultrasonic-assisted ethanol extract (USHE) from Sargassum horneri, a brown seaweed containing fucosterol (6.22 ± 0.06 mg/g), sulfoquinovosyl glycerolipids (C23H43O11S, C25H45O11S, C25H47O11S, C27H49O11S), and polyphenols, against oxidative damage in ultraviolet B (UVB)-exposed HaCaT keratinocytes. USHE indicated antioxidant activity in ferric-reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging. After screening experiments, 15.6, 31.3, and 62.5 µg/mL concentrations of USHE and ascorbic acid as positive control were selected to be used throughout the investigation. USHE increased cell viability by markedly reducing the production of intracellular reactive oxygen species (ROS) in UVB-exposed HaCaT keratinocytes. Additionally, USHE reduced the apoptosis and sub-G1 cell population and increased the mitochondrial membrane potential. Moreover, USHE modulated the protein expression levels of anti-apoptotic molecules (Bcl-xL, Bcl-2, and PARP) and pro-apoptotic molecules (Bax, cleaved caspase-3, p53, cleaved PARP, and cytochrome C). This modulation accorded with the upregulation of cytosolic heme oxygenase (HO)-1, NAD(P)H quinone oxidoreductase 1 (NQO 1), and nuclear factor erythroid-2-related factor 2 (Nrf2), collectively known as components of the antioxidant system. These findings suggest that USHE has a photoprotective effect on UVB-exposed HaCaT keratinocytes and can be utilized to develop cosmeceuticals for UVB protection.

The phytochemical plumbagin: mechanism behind its "pleiotropic" nature and potential as an anticancer treatment

Chemotherapeutics are most often used to treat cancer, but side effects, drug resistance, and toxicity often compromise their effectiveness. In contrast, phytocompound plumbagin possesses a distinct pleiotropic nature, targeting multiple signaling pathways, such as ROS generation, cell death, cellular proliferation, metastasis, and drug resistance, and is shown to enhance the efficacy of chemotherapeutic drugs. Plumbagin has been shown to act synergistically with various chemotherapeutic drugs and enhance their efficacy in drug-resistant cancers. The pleiotropic nature is believed to be due to plumbagin's unique structure, which contains a naphthoquinone ring and a hydroxyl group responsible for plumbagin's various biological responses. Despite limitations such as restricted bioavailability and delivery, recent developments aim to address these challenges and harness the potential of plumbagin as an anticancer therapeutics. This review delves into the structural aspect of the plumbagin molecule contributing to its pleiotropic nature, explores the diverse mechanism that it targets, and discusses emerging strategies to overcome its limitations.

PKCδ is an activator of neuronal mitochondrial metabolism that mediates the spacing effect on memory consolidation

Relevance-based selectivity and high energy cost are two distinct features of long-term memory (LTM) formation that warrant its default inhibition. Spaced repetition of learning is a highly conserved cognitive mechanism that can lift this inhibition. Here, we questioned how the spacing effect integrates experience selection and energy efficiency at the cellular and molecular levels. We showed in Drosophila that spaced training triggers LTM formation by extending over several hours an increased mitochondrial metabolic activity in neurons of the associative memory center, the mushroom bodies (MBs). We found that this effect is mediated by PKCδ, a member of the so-called 'novel PKC' family of enzymes, which uncovers the critical function of PKCδ in neurons as a regulator of mitochondrial metabolism for LTM. Additionally, PKCδ activation and translocation to mitochondria result from LTM-specific dopamine signaling on MB neurons. By bridging experience-dependent neuronal circuit activity with metabolic modulation of memory-encoding neurons, PKCδ signaling binds the cognitive and metabolic constraints underlying LTM formation into a unified gating mechanism.

Kolaviron: a Bioflavonoid from Seed Extract of Garcinia kola Attenuates Chromium (VI)-Induced Gut Dysfunction and Oxidative Damage in Drosophila melanogaster

Hexavalent chromium [Cr(VI)] is of public health significance due to its toxicity and carcinogenic effects. Kolaviron, a bio-flavonoid fraction from Garcinia kola seed, has been reported to possess gastroprotective and antioxidative properties. We hypothesize that Kolaviron-fortified diet will attenuate chromium (VI)-induced gut dysfunction and oxidative damage in Drosophila melanogaster. We exposed D. melanogaster (Oregon strain of 1-3 days old of both male and female) to a 1.0 mg/kg diet of chromium (VI), with or without Kolaviron (100 mg/kg diet) orally for 5 days. We evaluated markers of oxidative stress (total peroxide and protein carbonyl), antioxidative status (total thiols (T-SH), non-protein thiols (NP-SH), and catalase), and inflammatory (nitric oxide (nitrite and nitrate) and gut's morphology. The data indicated that Kolaviron ameliorated chromium (VI)-induced reduction in the levels of T-SH, NP-SH, and catalase activity (p < 0.05). In addition, Kolaviron attenuated chromium (VI)-induced elevation of total peroxide, protein carbonyl, and nitric oxide (p < 0.05). Kolaviron offered a protective role in chromium VI-induced toxicity in the gut of D. melanogaster. This study provided further insights into the protective mechanisms of Kolaviron against chromium (VI)-induced toxicity in D. melanogaster by maintaining epithelial integrity of the gut and oxidative stress-antioxidant balance.

Hydrogen-Rich Water to Enhance Exercise Performance: A Review of Effects and Mechanisms

Background: Hydrogen-rich water (HRW) has garnered significant interest within the sports and exercise science community due to its selective antioxidant properties. Despite its potential benefits, comprehensive reviews specifically addressing its effects on athletic performance are limited. This review aims to assess the impact of HRW on sports performance and explore the underlying molecular biological mechanisms, with the goal of elucidating how HRW might enhance athletic performance. Methods: This review synthesizes research on HRW by examining articles published between 1980 and April 2024 in databases such as PubMed, the Cochrane Library, Embase, Scopus, and Web of Science. Results: It highlights HRW's effects on various aspects of athletic performance, including endurance, strength, sprint times, lunge movements, countermovement jump height, and time to exhaustion. While the precise mechanisms by which HRW affects athletic performance remain unclear, this review investigates its general molecular biological mechanisms beyond the specific context of sports. This provides a theoretical foundation for future research aimed at understanding how HRW can enhance athletic performance. HRW targets the harmful reactive oxygen and nitrogen species produced during intense exercise, thereby reducing oxidative stress-a critical factor in muscle fatigue, inflammation, and diminished athletic performance. HRW helps to scavenge hydroxyl radicals and peroxynitrite, regulate antioxidant enzymes, mitigate lipid peroxidation, reduce inflammation, protect against mitochondrial dysfunction, and modulate cellular signaling pathways. Conclusions: In summary, while a few studies have indicated that HRW may not produce significant beneficial effects, the majority of research supports the conclusion that HRW may enhance athletic performance across various sports. The potential mechanisms underlying these benefits are thought to involve HRW's role as a selective antioxidant, its impact on oxidative stress, and its regulation of redox homeostasis. However, the specific molecular biological mechanisms through which HRW improves athletic performance remain to be fully elucidated.

Short-term induced swimming activity enhanced innate immune parameters and antioxidant status of European eel (Anguilla anguilla)

The swimming activity, although an essential trait in the life cycle of fish, is still poorly understood in farmed fish. The current study aimed to investigate the impact of short-term induced swimming on the immune and antioxidant defence systems in European eel (Anguilla anguilla). Sixteen male yellow European eels (total length: 39.9 ± 0.7 cm; body weight: 108.8 ± 6.1 g) were individually placed in swimming flumes and divided into two groups: i) no swimming (n = 8); and ii) induced-swimming (n = 8) at 0.3 body lengths (BL)·s-1 for 7 h. Swimming resulted in a 2-fold lower cortisol concentration in plasma, whereas plasma glucose, lactate, and several immune-related parameters did not present variations between groups. Interestingly, swimming led to higher lysozyme, peroxidase, and protease activities in skin mucus, whereas bactericidal activity did not show differences among groups. Additionally, the gene expression of interleukin 1 beta showed an up-regulation in the skin of fish with induced swimming, while no differences were observed in the head-kidney or gills. Furthermore, modulation of the antioxidant status was observed in the liver and posterior skeletal muscle after induced swimming. Fish subjected to swimming showed lower lipid peroxidation and higher reduced glutathione levels, increasing the reduced/oxidized glutathione ratio. However, no variations in the antioxidant status were observed between groups in the anterior skeletal muscle. This study showed modulation of immune and oxidative stress markers in European eels upon short-term induced swimming compared to non-swimming fish.

Chlorpyrifos induces cytotoxicity via oxidative stress and mitochondrial dysfunction in HepG2 cells

Chlorpyrifos (CPF), a widely used broad-spectrum organophosphate pesticide, has been associated with various adverse health effects in animals and humans. While its primary mechanism of action involves the irreversible inhibition of acetylcholinesterase, secondary mechanisms have also been suggested. The aim of the present study was to explore the secondary mechanisms of action involved in CPF-induced acute cytotoxicity using human hepatocarcinoma HepG2 cells. In particular, we investigated oxidative stress and mitochondrial function by assessing reactive oxygen species (ROS) generation, lipid peroxidation (LPO) and mitochondrial membrane potential (ΔΨm) alteration. Results showed that 24-h exposure to CPF (78.125-2500 μM) decreased cell viability in a concentration-dependent manner (IC50 = 280.87 ± 26.63 μM). Sub-toxic CPF concentrations (17.5, 35 and 70 μM) induced increases in ROS generation (by 83%), mitochondrial superoxide (by 7.1%), LPO (by 11%), and decreased ΔΨm (by 20%). CPF also upregulated Nrf2 protein expression, indicating the role of the latter in modulating the cellular response to oxidative insults. Overall, our findings suggest that CPF caused hepatotoxicity through oxidative stress and mitochondrial dysfunction. Given the re-emerging use of CPF, this study emphasizes the need for comprehensive analysis to elucidate its toxicity on non-target organs and associated mechanisms.

Mitochondrial morphology, distribution and activity during oocyte development

Mitochondria have a crucial role in cellular function and exhibit remarkable plasticity, adjusting both their structure and activity to meet the changing energy demands of a cell. Oocytes, female germ cells that become eggs, undergo unique transformations: the extended dormancy period, followed by substantial increase in cell size and subsequent maturation involving the segregation of genetic material for the next generation, present distinct metabolic challenges necessitating varied mitochondrial adaptations. Recent findings in dormant oocytes challenged the established respiratory complex hierarchies and underscored the extent of mitochondrial plasticity in long-lived oocytes. In this review, we discuss mitochondrial adaptations observed during oocyte development across three vertebrate species (Xenopus, mouse, and human), emphasising current knowledge, acknowledging limitations, and outlining future research directions.

Endothelial Reactive Oxygen Species: Key Players in Cardiovascular Health and Disease

Significance: Endothelial cells (ECs) line the entire vasculature system and serve as both barriers and facilitators of intra- and interorgan communication. Positioned to rapidly sense internal and external stressors, ECs dynamically adjust their functionality. Endothelial dysfunction occurs when the ability of ECs to react to stressors is impaired, which precedes many cardiovascular diseases (CVDs). While EC reactive oxygen species (ROS) have historically been implicated as mediators of endothelial dysfunction, more recent studies highlight the central role of ROS in physiological endothelial signaling. Recent Advances: New evidence has uncovered that EC ROS are fundamental in determining how ECs interact with their environment and respond to stress. EC ROS levels are mediated by external factors such as diet and pathogens, as well as inherent characteristics, including sex and location. Changes in EC ROS impact EC function, leading to changes in metabolism, cell communication, and potentially disrupted signaling in CVDs. Critical Issues: Current endothelial biology concepts integrate the dual nature of ROS, emphasizing the importance of EC ROS in physiological stress adaptation and their contribution to CVDs. Understanding the discrete, localized signaling of EC ROS will be critical in preventing adverse cardiovascular outcomes. Future Directions: Exploring how the EC ROS environment alters EC function and cross-cellular communication is critical. Considering the inherent heterogeneity among EC populations and understanding how EC ROS contribute to this diversity and the role of sexual dimorphism in the EC ROS environment will be fundamental for developing new effective cardiovascular treatment strategies.

Harnessing Cannabis sativa Oil for Enhanced Skin Wound Healing: The Role of Reactive Oxygen Species Regulation

Cannabis sativa emerges as a noteworthy candidate for its medicinal potential, particularly in wound healing. This review article explores the efficacy of cannabis oil in reducing reactive oxygen species (ROS) during the healing of acute and chronic wounds, comparing it to the standard treatments. ROS, produced from various internal and external sources, play a crucial role in wound development by causing cell and tissue damage. Understanding the role of ROS on skin wounds is essential, as they act both as signaling molecules and contributors to oxidative damage. Cannabis oil, recognized for its antioxidant properties, may help mitigate oxidative damage by scavenging ROS and upregulating antioxidative mechanisms, potentially enhancing wound healing. This review emphasizes ongoing research and the future potential of cannabis oil in dermatological treatments, highlighted through clinical studies and patent updates. Despite its promising benefits, optimizing cannabis oil formulations for therapeutic applications remains a challenge, underscoring the need for further research to realize its medicinal capabilities in wounds.

Relationship of SOD-1 Activity in Metabolic Syndrome and/or Frailty in Elderly Individuals

INTRODUCTION

Although aging is a natural phenomenon, in recent years it has accelerated. One key factor implicated in the aging process is oxidative stress. Oxidative stress also plays a role in frailty (frail) and metabolic syndrome (MetS).

METHODS

A total of 66 elderly persons (65 years old and older) with no acute or severe chronic disorders were assessed for waist circumference (WC), arterial blood pressure, glycemia, glycated hemoglobin (HbA1c), plasma lipids, and activity of erythrocyte superoxide dismutase (SOD-1). Patients were classified as NonMetS-Nonfrail (n = 19), NonMetS-frail (n = 20), MetS-Nonfrail (n = 17), or MetS-frail (n = 10).

RESULTS

There were no significant differences in superoxide dismutase activity among investigated elderly groups. However, the data suggest that MetS individuals, both frail and nonfrail, have higher risk factors for cardiovascular disease compared to NonMetS individuals. The correlations analyses of SOD-1 and other metabolic indices suggest that SOD-1 levels may be influenced by age, total cholesterol, HDL cholesterol, and fasting glucose levels in certain groups of seniors.

CONCLUSIONS

Aging is associated with decreased antioxidant enzyme SOD-1 activity with glucose alteration in frailty syndrome as well as with lipids disturbances in metabolic syndrome. These factors provide a nuanced view of how frailty and metabolic syndrome interact with various health parameters, informing both clinical practice and future research directions.

Contrasting Effects of an Atherogenic Diet and High-Protein/Unsaturated Fatty Acids Diet on the Accelerated Aging Mouse Model SAMP8 Phenotype

Background/Objectives: Aging has been extensively studied, with a growing interest in memory impairment by a neurobiological approach. Mitochondrial dysfunction is a hallmark of aging, contributing to the aging phenotype; therefore, mitochondrial interventions seem fundamental. The diet is a physiological approximation for modifying mitochondria, which could impact the age-related phenotype. Methods: We studied two diets with low-carbohydrate and high-fat compositions, differing in the amount of protein and the fat type disposable-the atherogenic diet Cocoa (high protein/high saturated fat/high cholesterol) and the South Beach diet (very high-protein/high-unsaturated fat)-on oxidative stress, mitochondrial state, and hippocampus-dependent memory in 3-month-old Senescence-Accelerated Mouse Model (SAMP8) seed over 3 months to determine their pro- or anti-aging effects. Results: Despite its bad reputation, the Cocoa diet reduces the reactive oxygen species (ROS) content without impacting the energy state and hippocampus-dependent spatial acuity. In contrast to the beneficial impact proposed for the South Beach diet, it induced a pro-aging phenotype, increasing oxidative damage and the levels of NR2B subunit of the NMDA, impairing energy and spatial acuity. Surprisingly, despite the negative changes observed with both diets, this led to subtle memory impairment, suggesting the activation of compensatory mechanisms preventing more severe cognitive decline. Conclusions: Our results demonstrated that diets usually considered good could be detrimental to the onset of aging. Also, probably due to the brain plasticity of non-aged animals, they compensate for the damage, preventing a more aggravated phenotype. Nevertheless, these silent changes could predispose or increase the risk of suffering pathologies at advanced age.

Senescence Rejuvenation through Reduction in Mitochondrial Reactive Oxygen Species Generation by Polygonum cuspidatum Extract: In Vitro Evidence

Oxidative stress caused by reactive oxygen species (ROS) is one of the major causes of senescence. Strategies to reduce ROS are known to be important factors in reversing senescence, but effective strategies have not been found. In this study, we screened substances commonly used as cosmetic additives to find substances with antioxidant effects. Polygonum cuspidatum (P. cuspidatum) extract significantly reduced ROS levels in senescent cells. A novel mechanism was discovered in which P. cuspidatum extract reduced ROS, a byproduct of inefficient oxidative phosphorylation (OXPHOS), by increasing OXPHOS efficiency. The reduction in ROS by P. cuspidatum extract restored senescence-associated phenotypes and enhanced skin protection. Then, we identified polydatin as the active ingredient of P. cuspidatum extract that exhibited antioxidant effects. Polydatin, which contains stilbenoid polyphenols that act as singlet oxygen scavengers through redox reactions, increased OXPHOS efficiency and subsequently restored senescence-associated phenotypes. In summary, our data confirmed the effects of P. cuspidatum extract on senescence rejuvenation and skin protection through ROS reduction. This novel finding may be used as a treatment in senescence rejuvenation in clinical and cosmetic fields.

BMP receptor 2 inhibition regulates mitochondrial bioenergetics to induce synergistic cell death with BCL-2 inhibitors in leukemia and NSLC cells

Background

Bone morphogenetic protein (BMP) signaling cascade is a phylogenetically conserved stem cell regulator that is aberrantly expressed in non-small cell lung cancer (NSLC) and leukemias. BMP signaling negatively regulates mitochondrial bioenergetics in lung cancer cells. The impact of inhibiting BMP signaling on mitochondrial bioenergetics and the effect this has on the survival of NSLC and leukemia cells are not known.

Methods

Utilizing the BMP type 2 receptor (BMPR2) JL189, BMPR2 knockout (KO) in cancer cells, and BMP loss of function mutants in C elegans, we determined the effects of BMPR2 inhibition (BMPR2i) on TCA cycle metabolic intermediates, mitochondrial respiration, and the regulation of mitochondrial superoxide anion (SOA) and Ca++ levels. We also examined whether BMPR2i altered the threshold cancer therapeutics induce cell death in NSLC and leukemia cell lines. KO of the mitochondria uniporter (MCU) was used to determine the mechanism BMPR2i regulates the uptake of Ca++ into the mitochondria, mitochondrial bioenergetics, and cell death.

Results

BMPR2i increases mtCa++ levels and enhances mitochondrial bioenergetics in both NSLC and leukemia cell lines that is conserved in C elegans. BMPR2i induced increase in mtCa++ levels is regulated through the MCU, effecting mitochondria mass and cell survival. BMPR2i synergistically induced cell death when combined with BCL-2 inhibitors or microtubule targeting agents in both NSLC and leukemia cells. Cell death is caused by synergistic increase in mitochondrial ROS and Ca++ levels. BMPR2i enhances Ca++ uptake into the mitochondria induced by reactive oxygen species (ROS) produced by cancer therapeutics. Both acute myeloid leukemia (AML) and T-cell lymphoblastic leukemia cells lines were more responsive to the JL189 alone and when combined with venetoclax or navitoclax compared to NSLC.

Impact of the redox-active MnTnHex-2-PyP5+ and cisplatin on the metabolome of non-small cell lung cancer cells

Redox-based cancer therapeutic strategies aim to raise reactive oxygen species (ROS) levels in cancer cells, thus modifying their redox status, and eventually inducing cell death. Promising compounds, known as superoxide dismutase mimics (SODm), e.g. MnTnHex-2-Py5+ (MnTnHex), could increase intracellular H2O2 in cancer cells with deficient ROS removal systems and therefore enhance radio- and chemotherapy efficacy. We have previously shown that MnTnHex was cytotoxic either alone or combined with cisplatin to non-small cell lung cancer (NSCLC) cells. To gain a deeper understanding of the effects and safety of this compound, it is crucial to analyze the metabolic alterations that take place within the cell. Our goal was thus to study the intracellular metabolome (intracellular metabolites) of NSCLC cells (A549 and H1975) using nuclear magnetic resonance (NMR) spectroscopy-based metabolomics to evaluate the changes in cellular metabolism upon exposure to MnTnHex per se or in combination with cisplatin. 1H NMR metabolomics revealed a higher number of significantly altered metabolites in A549 cells exposed to MnTnHex alone or combined with cisplatin in comparison with non-treated cells (nine dysregulated metabolites), suggesting an impact on aminoacyl-tRNA biosynthesis, glycolysis/gluconeogenesis, taurine, hypotaurine, glycerophospholipid, pyruvate, arginine and proline metabolisms. Regarding H1975 cells, significant alterations in the levels of six metabolites were observed upon co-treatment with MnTnHex and cisplatin, suggesting dysregulations in aminoacyl-tRNA biosynthesis, arginine and proline metabolism, pyruvate metabolism, and glycolysis/gluconeogenesis. These findings help us to understand the impact of MnTnHex on NSCLC cells. Importantly, specific altered metabolites, such as taurine, may contribute to the chemosensitizing effects of MnTnHex.

Design and synthesis of visible light-activatable photocaged peroxides for optical control of ROS-mediated cellular signaling

We designed and synthesized two novel photocaged peroxide compounds, N5TBHP and N6TBHP, featuring nitrogen-containing fused ring coumarin skeletons. Notably, a tetrahydroquinoline fused coumarin derivative, N6TBHP demonstrated significantly higher photocleavage efficiency under visible light at 455 nm compared to N5TBHP, which contains an indoline fused coumarin. This process effectively releases the oxidative stress inducer tert-butylhydroperoxide (TBHP). Additionally, N6TBHP exhibits high resistance to glutathione (GSH), and its UV spectral analysis suggests enhanced intracellular stability due to reduced reactivity with GSH through self-assembly. Furthermore, N6TBHP can release an optimal amount of TBHP into cells under visible light irradiation with minimal cell damage. These properties position N6TBHP as a promising tool for advancing research in intracellular redox signaling.

Ryegrass uptake behavior and forage risk assessment after exposing to soil with combined polycyclic aromatic hydrocarbons and cadmium

Internalization of chemicals and the forage risks of ryegrass under the combined exposure to PAHs and Cd at environmental concentrations were studied here. The effect of soil pH was also concerned due to the widely occurred soil acidification and general alkali remediation for acidification soil. Unexpectedly, as same as the acid-treated group (pH 6.77), the alkali-treatment (pH 8.83) increased Cd uptake compared with original soil pH group (pH 7.92) for the reason of CdOH+ and CdHCO3+ formed in alkali-treated group. Co-exposure to PAHs induced more oxidative stress than Cd exposure alone due to PAHs aggregated in young root regions, such as root tips, and consequently, affecting the expression of Cd-transporters, destroying the basic structure of plant cells, inhibiting the energy supply for the transporters, even triggering programmed cell death, and finally resulting in decreased Cd uptake. Even under environmental concentrations, combined exposure caused potential risks derived from both PAHs and Cd. Especially, ryegrass grown in alkali-treated soil experienced an increased forage risks despite the soil meeting the national standards for Cd at safe levels. These comprehensive results reveal the mechanism of PAHs inhibiting Cd uptake, improve the understanding of bioavailability of Cd based on different forms, provide a theoretical basis to formulate the safety criteria, and guide the application of actual soil management.

Intelligent salivary biosensors for periodontitis: in vitro simulation of oral oxidative stress conditions

ASTRACT

One of the most common oral diseases affecting millions of people worldwide is periodontitis. Usually, proteins in body fluids are used as biomarkers of diseases. This study focused on hydrogen peroxide, lipopolysaccharide (LPS), and lactic acid as salivary non-protein biomarkers for oxidative stress conditions of periodontitis. Electrochemical analysis of artificial saliva was done using Gamry with increasing hydrogen peroxide, bLPS, and lactic acid concentrations. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were conducted. From EIS data, change in capacitance and CV plot area were calculated for each test condition. Hydrogen peroxide groups had a decrease in CV area and an increase in percentage change in capacitance, lipopolysaccharide groups had a decrease in CV area and a decrease in percentage change in capacitance, and lactic acid groups had an increase of CV area and an increase in percentage change in capacitance with increasing concentrations. These data showed a unique combination of electrochemical properties for the three biomarkers. Scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) employed to observe the change in the electrode surface and elemental composition data present on the sensor surface also showed a unique trend of elemental weight percentages. Machine learning models using hydrogen peroxide, LPS, and lactic acid electrochemical data were applied for the prediction of risk levels of periodontitis. The detection of hydrogen peroxide, LPS, and lactic acid by electrochemical biosensors indicates the potential to use these molecules as electrochemical biomarkers and use the data for ML-driven prediction tool for the periodontitis risk levels.

Oxidative stress mediates nucleocytoplasmic shuttling of KPNA2 via AKT1-CDK1 axis-regulated S62 phosphorylation

Karyopherin α 2 (KPNA2, importin α1), a transport factor shuttling between the nuclear and cytoplasmic compartments, is involved in the nuclear import of proteins and participates in cellular processes such as cell cycle regulation, apoptosis, and transcriptional regulation. However, it is still unclear which signaling regulates the nucleocytoplasmic distribution of KPNA2 in response to cellular stress. In this study, we report that oxidative stress increases nuclear retention of KPNA2 through alpha serine/threonine-protein kinase (AKT1)-mediated reduction of serine 62 (S62) phosphorylation. We first found that AKT1 activation was required for H2O2-induced nuclear accumulation of KPNA2. Immunoprecipitation and quantitative proteomic analysis revealed that the phosphorylation of KPNA2 at S62 was decreased under H2O2-induced oxidative stress. We showed that cyclin-dependent kinase 1 (CDK1), a kinase responsible for KPNA2 S62 phosphorylation, contributes to the localization of KPNA2 in the cytoplasm. AKT1 knockdown increased KPNA2 S62 phosphorylation and inhibited CDK1 activation. Furthermore, H2O2-induced AKT1 activation promoted nuclear KPNA2 interaction with nucleophosmin 1 (NPM1), resulting in attenuation of NPM1-mediated cyclin D1 gene transcription. Thus, we infer that the AKT1-CDK1 axis regulates the nucleocytoplasmic shuttling and function of KPNA2 through spatiotemporal regulation of KPNA2 S62 phosphorylation under oxidative stress conditions.

Dual Effect of Carnosine on ROS Formation in Rat Cultured Cortical Astrocytes

Carnosine is composed of β-alanine and L-histidine and is considered to be an important neuroprotective agent with antioxidant, metal chelating, and antisenescence properties. However, children with serum carnosinase deficiency present increased circulating carnosine and severe neurological symptoms. We here investigated the in vitro effects of carnosine on redox and mitochondrial parameters in cultured cortical astrocytes from neonatal rats. Carnosine did not alter mitochondrial content or mitochondrial membrane potential. On the other hand, carnosine increased mitochondrial superoxide anion formation, levels of thiobarbituric acid reactive substances and oxidation of 2',7'-dichlorofluorescin diacetate (DCF-DA), indicating that carnosine per se acts as a pro-oxidant agent. Nonetheless, carnosine prevented DCF-DA oxidation induced by H2O2 in cultured cortical astrocytes. Since alterations on mitochondrial membrane potential are not likely to be involved in these effects of carnosine, the involvement of N-Methyl-D-aspartate (NMDA) receptors in the pro-oxidant actions of carnosine was investigated. MK-801, an antagonist of NMDA receptors, prevented DCF-DA oxidation induced by carnosine in cultured cortical astrocytes. Astrocyte reactivity induced by carnosine was also prevented by the coincubation with MK-801. The present study shows for the very first time the pro-oxidant effects of carnosine per se in astrocytes. The data raise awareness on the importance of a better understanding of the biological actions of carnosine, a nutraceutical otherwise widely reported as devoid of side effects.

Fmp40 ampylase regulates cell survival upon oxidative stress by controlling Prx1 and Trx3 oxidation

Reactive oxygen species (ROS), play important roles in cellular signaling, nonetheless are toxic at higher concentrations. Cells have many interconnected, overlapped or backup systems to neutralize ROS, but their regulatory mechanisms remain poorly understood. Here, we reveal an essential role for mitochondrial AMPylase Fmp40 from budding yeast in regulating the redox states of the mitochondrial 1-Cys peroxiredoxin Prx1, which is the only protein shown to neutralize H2O2 with the oxidation of the mitochondrial glutathione and the thioredoxin Trx3, directly involved in the reduction of Prx1. Deletion of FMP40 impacts a cellular response to H2O2 treatment that leads to programmed cell death (PCD) induction and an adaptive response involving up or down regulation of genes encoding, among others the catalase Cta1, PCD inducing factor Aif1, and mitochondrial redoxins Trx3 and Grx2. This ultimately perturbs the reduced glutathione and NADPH cellular pools. We further demonstrated that Fmp40 AMPylates Prx1, Trx3, and Grx2 in vitro and interacts with Trx3 in vivo. AMPylation of the threonine residue 66 in Trx3 is essential for this protein's proper endogenous level and its precursor forms' maturation under oxidative stress conditions. Additionally, we showed the Grx2 involvement in the reduction of Trx3 in vivo. Taken together, Fmp40, through control of the reduction of mitochondrial redoxins, regulates the hydrogen peroxide, GSH and NADPH signaling influencing the yeast cell survival.

Molecular cascade reveals sequential milestones underlying hippocampal neural stem cell development into an adult state

Quiescent adult neural stem cells (NSCs) in the mammalian brain arise from proliferating NSCs during development. Beyond acquisition of quiescence, an adult NSC hallmark, little is known about the process, milestones, and mechanisms underlying the transition of developmental NSCs to an adult NSC state. Here, we performed targeted single-cell RNA-seq analysis to reveal the molecular cascade underlying NSC development in the early postnatal mouse dentate gyrus. We identified two sequential steps, first a transition to quiescence followed by further maturation, each of which involved distinct changes in metabolic gene expression. Direct metabolic analysis uncovered distinct milestones, including an autophagy burst before NSC quiescence acquisition and cellular reactive oxygen species level elevation along NSC maturation. Functionally, autophagy is important for the NSC transition to quiescence during early postnatal development. Together, our study reveals a multi-step process with defined milestones underlying establishment of the adult NSC pool in the mammalian brain.

Alkaptonuria: From Molecular Insights to a Dedicated Digital Platform

Alkaptonuria (AKU) is a genetic disorder that affects connective tissues of several body compartments causing cartilage degeneration, tendon calcification, heart problems, and an invalidating, early-onset form of osteoarthritis. The molecular mechanisms underlying AKU involve homogentisic acid (HGA) accumulation in cells and tissues. HGA is highly reactive, able to modify several macromolecules, and activates different pathways, mostly involved in the onset and propagation of oxidative stress and inflammation, with consequences spreading from the microscopic to the macroscopic level leading to irreversible damage. Gaining a deeper understanding of AKU molecular mechanisms may provide novel possible therapeutical approaches to counteract disease progression. In this review, we first describe inflammation and oxidative stress in AKU and discuss similarities with other more common disorders. Then, we focus on HGA reactivity and AKU molecular mechanisms. We finally describe a multi-purpose digital platform, named ApreciseKUre, created to facilitate data collection, integration, and analysis of AKU-related data.

PKCδ is an activator of neuronal mitochondrial metabolism that mediates the spacing effect on memory consolidation

Relevance-based selectivity and high energy cost are two distinct features of long-term memory (LTM) formation that warrant its default inhibition. Spaced repetition of learning is a highly conserved cognitive mechanism that can lift this inhibition. Here, we questioned how the spacing effect integrates experience selection and energy efficiency at the cellular and molecular levels. We showed in Drosophila that spaced training triggers LTM formation by extending over several hours an increased mitochondrial metabolic activity in neurons of the associative memory center, the mushroom bodies (MBs). We found that this effect is mediated by PKCδ, a member of the so-called 'novel PKC' family of enzymes, which uncovers the critical function of PKCδ in neurons as a regulator of mitochondrial metabolism for LTM. Additionally, PKCδ activation and translocation to mitochondria result from LTM-specific dopamine signaling on MB neurons. By bridging experience-dependent neuronal circuit activity with metabolic modulation of memory-encoding neurons, PKCδ signaling binds the cognitive and metabolic constraints underlying LTM formation into a unified gating mechanism.

Host stress drives tolerance and persistence: The bane of anti-microbial therapeutics

Antibiotic resistance, typically associated with genetic changes within a bacterial population, is a frequent contributor to antibiotic treatment failures. Antibiotic persistence and tolerance, which we collectively term recalcitrance, represent transient phenotypic changes in the bacterial population that prolong survival in the presence of typically lethal concentrations of antibiotics. Antibiotic recalcitrance is challenging to detect and investigate-traditionally studied under in vitro conditions, our understanding during infection and its contribution to antibiotic failure is limited. Recently, significant progress has been made in the study of antibiotic-recalcitrant populations in pathogenic species, including Mycobacterium tuberculosis, Staphylococcus aureus, Salmonella enterica, and Yersiniae, in the context of the host environment. Despite the diversity of these pathogens and infection models, shared signals and responses promote recalcitrance, and common features and vulnerabilities of persisters and tolerant bacteria have emerged. These will be discussed here, along with progress toward developing therapeutic interventions to better treat recalcitrant pathogens.

Electrical Pulse Stimulation Protects C2C12 Myotubes against Hydrogen Peroxide-Induced Cytotoxicity via Nrf2/Antioxidant Pathway

Skeletal muscle contraction evokes numerous biochemical alterations that underpin exercise benefits. This present study aimed to elucidate the mechanism for electrical pulse stimulation (EPS)-induced antioxidant adaptation in C2C12 myotubes. We found that EPS significantly upregulated Nrf2 and a broad array of downstream antioxidant enzymes involved in multiple antioxidant systems. These effects were completely abolished by pretreatment with a ROS scavenger, N-acetylcysteine. MitoSOX-Red, CM-H2DCFDA, and EPR spectroscopy revealed a significantly higher ROS level in mitochondria and cytosol in EPS cells compared to non-stimulated cells. Seahorse and Oroboros revealed that EPS significantly increased the maximal mitochondrial oxygen consumption rate, along with an upregulated protein expression of mitochondrial complexes I/V, mitofusin-1, and mitochondrial fission factor. A post-stimulation time-course experiment demonstrated that upregulated NQO1 and GSTA2 last at least 24 h following the cessation of EPS, whereas elevated ROS declines immediately. These findings suggest an antioxidant preconditioning effect in the EPS cells. A cell viability study suggested that the EPS cells displayed 11- and 36-fold higher survival rates compared to the control cells in response to 2 and 4 mM H2O2 treatment, respectively. In summary, we found that EPS upregulated a large group of antioxidant enzymes in C2C12 myotubes via a contraction-mitochondrial-ROS-Nrf2 pathway. This antioxidant adaptation protects cells against oxidative stress-associated cytotoxicity.