Use of H2O2 to Cause Oxidative Stress, the Catalase Issue

Electrochemical biosensors for early detection of Alzheimer's disease

In recent years, electrochemical biosensors have shown great promise as innovative tools for the early identification of Alzheimer's disease (AD), a neurodegenerative disorder that severely affects cognitive ability and overall quality of life. This comprehensive review aims to consolidate the latest research on the creation and implementation of electrochemical biosensors designed to detect AD-related biomarkers. We examine cutting-edge approaches to surface modification that enhance the attachment of biorecognition molecules, thus enabling the simultaneous identification of multiple biomarkers. This review emphasizes the crucial role that electrochemical biosensors play in the early diagnosis of Alzheimer's disease, highlighting their potential to revolutionize clinical practices by facilitating timely interventions. In the future, research efforts should concentrate on refining these technologies for widespread clinical adoption, ensuring that they meet the needs of both healthcare professionals and patients.

Novel 2,5-dihydro-3H-[1,2,4]triazino[5,6-b]indole derivatives decorated with disulfide moiety are effective for treating bacterial infections by inducing reactive oxygen species

BACKGROUND

Infectious diseases caused by pathogenic bacteria are the main causes of death in humans, and responsible for reduced yield quality and quantity of plants globally. This underscores the need for developing bactericide alternatives with novel modes-of-action.

RESULTS

Herein, we devised a series of novel 2,5-dihydro-3H-[1,2,4]triazino[5,6-b]indole derivatives decorating with the disulfide moiety (W1-W36). Bioassay results indicated their antibacterial activity against three pathogenic bacteria [Xoo (Xanthomonas oryzae pv. oryzae), Xac (Xanthomonas axonopodis pv. citri) and Psa (Pseudomonas syringae pv. actinidiae)]. Compound W1 demonstrated eminent anti-Xoo activity in vitro, with a median effecgtive concentration (EC50) value of 0.77 μg mL-1, which was considerably higher than that of the reference agent thiodiazole copper (TC, EC50 = 104 μg mL-1). At 200 μg mL-1, compound W1 demonstrated better in vivo control efficiency (46.09% curative activity; 51.26% protective activity) toward rice bacterial blight diseases, with a >20% increase in activity relative to that of the control TC. Mechanistic studies revealed that compound W1 enabled the suppression of the activities of oxidoreductases including superoxide dismutase and catalase, disrupted the redox balance, and ultimately induced bacterial cell apoptosis.

CONCLUSION

Overall, these new molecules were characterized by high antibacterial ability, reactive oxygen species targeting performance, and low toxicity. They demonstrated unprecedented potential for controlling bacterial infection. © 2025 Society of Chemical Industry.

Enzyme-Based Anti-Inflammatory Therapeutics for Inflammatory Diseases

Inflammation is a multifaceted biological response of the immune system against various harmful stimuli, including pathogens (such as bacteria and viruses), cellular damage, toxins, and natural/synthetic irritants. This protective mechanism is essential for eliminating the cause of injury, removing damaged cells, and initiating the repair process. While inflammation is a fundamental component of the body's defense and healing process, its dysregulation can lead to pathological consequences, contributing to various acute and chronic diseases, such as autoimmune disorders, cancer, metabolic syndromes, cardiovascular diseases, neurodegenerative conditions, and other systemic complications. Generally, non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, disease-modifying anti-rheumatic drugs (DMARDs), antihistamines, biologics, and colchicine are used as pharmacological agents in the management of inflammatory diseases. However, these conventional treatments often have limitations, including adverse side effects, long-term toxicity, and drug resistance. In contrast, enzyme-based therapeutics have emerged as a promising alternative due to their high specificity, catalytic efficiency, and ability to modulate inflammatory pathways with reduced side effects. These enzymes function by scavenging reactive oxygen species (ROS), inhibiting cytokine transcription, degrading circulating cytokines, and blocking cytokine release by targeting exocytosis-related receptors. Additionally, their role in tissue repair and regeneration further enhances their therapeutic potential. Most natural anti-inflammatory enzymes belong to the oxidoreductase class, including catalase and superoxide dismutase, as well as hydrolases such as trypsin, chymotrypsin, nattokinase, bromelain, papain, serratiopeptidase, collagenase, hyaluronidase, and lysozyme. Engineered enzymes, such as Tobacco Etch Virus (TEV) protease and botulinum neurotoxin type A (BoNT/A), have also demonstrated significant potential in targeted anti-inflammatory therapies. Recent advancements in enzyme engineering, nanotechnology-based enzyme delivery, and biopharmaceutical formulations have further expanded their applicability in treating inflammatory diseases. This review provides a comprehensive overview of both natural and engineered enzymes, along with their formulations, used as anti-inflammatory therapeutics. It highlights improvements in stability, efficacy, and specificity, as well as minimized immunogenicity, while discussing their mechanisms of action and clinical applications and potential future developments in enzyme-based biomedical therapeutics.

Oxidative stress responses and histological changes in the liver of Nile tilapia exposed to silver bulk and nanoparticles

The increased utilization of silver nanoparticles (AgNPs) in multiple applications is leading to a rise in environmental contamination caused by their release, particularly in aquatic ecosystems. This study investigates the effects of different concentrations of AgNPs (10, 20, 50, and 100 µg/L) and bulk silver nitrate (AgNO3) at 100 µg/L, on the hepatic antioxidant defense system, oxidative stress markers, and liver histopathology of Nile tilapia (Oreochromis niloticus), with sampling conducted biweekly over six weeks. AgNPs were chemically synthesized using trisodium acetate, yielding an average crystallite size of 29.92 nm. Results demonstrated that both antioxidant enzyme activities and lipid peroxidation (LPO) levels in Nile tilapia exhibited a dose-dependent response. During weeks 2 and 4, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), activities, along with LPO levels were significantly increased, while TAC levels notably decreased, especially at higher AgNPs concentrations. By week 6, antioxidant enzyme activities were suppressed, and LPO levels were markedly elevated in the higher AgNPs groups (AgNPs-50 and AgNPs-100). In contrast, fish exposed to bulk AgNO3 exhibited activation of the enzymatic antioxidant system, although LPO levels remained elevated throughout the experimental period. Histopathological analysis revealed progressive liver damage, including congestion, dilation, fibrosis, fatty degeneration, and necrosis. These effects were more pronounced with higher doses of AgNPs. The results showed a mitigation response among all experimental groups during the first four weeks. However, by week 6, the antioxidant system in Nile tilapia exposed to higher doses of AgNPs failed to cope with the induced oxidative stress. This underscores the significantly higher ecological risks associated with prolonged exposure to AgNPs compared to AgNO3, revealing a critical concern for the stability and health of aquatic ecosystems.

Proteomics Analysis of the TDP-43 Interactome in Cellular Models of ALS Pathogenesis

Cytoplasmic aggregation and nuclear depletion of TAR DNA-binding protein 43 (TDP-43) is a hallmark pathology of several neurodegenerative diseases including amyotrophic lateral sclerosis (ALS), frontotemporal lobar degeneration (FTLD) and limbic-predominant age-related TDP-43 encephalopathy (LATE). However, the protein interactome of TDP-43 remains incompletely defined. In this study, we aimed to identify putative TDP-43 protein partners within the nucleus and the cytoplasm and with different disease models of TDP-43 by comparing TDP-43 interaction partners in three different cell lines. We verified the levels of interaction of protein partners under stress conditions as well as after introducing TDP-43 variants containing ALS missense mutations (G294V and A315T). Overall, we identified 58 putative wild-type TDP-43 interactors, including novel binding partners responsible for RNA metabolism and splicing. Oxidative stress exposure broadly led to changes in TDP-43WT interactions with proteins involved in mRNA metabolism, suggesting a dysregulation of the transcriptional machinery early in disease. Conversely, although G294V and A315T mutations are both located in the C-terminal domain of TDP-43, both mutants presented different interactome profiles with most interaction partners involved in translational and transcriptional machinery. Overall, by correlating different cell lines and disease-simulating interventions, we provide a list of high-confidence TDP-43 interaction partners, including novel and previously reported proteins. Understanding pathological changes to TDP-43 and its specific interaction partners in different models of stress is critical to better understand TDP-43 proteinopathies and provide novel potential therapeutic targets and biomarkers.

Vitamin D receptor upregulation promotes ferroptosis-related salivary hyposecretion caused by Sod1 knockout in female mice

Oxidative stress is a key factor in reducing salivary flow and damaging salivary gland tissues, and females are more likely to experience saliva hyposecretion than males, with the underlying mechanism not elucidated. To investigate the potential link between salivary gland function and systemic oxidative stress, we employed a superoxide dismutase 1 gene (Sod1) knockout (SKO) mouse model to simulate elevated endogenous oxidative stress. Concurrent with increased endogenous reactive oxygen species (ROS) levels, we observed reduced salivary production, increased vitamin D receptor (VDR) expression, and altered gene expression profiles associated with ferroptosis, inflammation, and circadian regulation. These changes were specifically detected in female SKO mice but not in their male counterparts. In A253 salivary gland epithelial cells, exposure to 4-nitroquinoline N-oxide (4NQO), a superoxide inducer, led to the expression changes of ferroptosis-related genes and VDR. Overexpressed VDR enhanced the expression of transferrin receptor (TFRC) by targeting its predicted gene promoter, which stimulates ferroptosis. Ferroptosis occurs in the salivary glands of female SKO mice, contributing to impaired salivary secretion. Our findings underscore the potential role of VDR upregulation in reducing salivary secretion by modulating ferroptosis pathways and offer a promising avenue for future research to develop therapeutic strategies for preventing dry mouth and salivary gland dysfunction associated with oxidative stress and aging.

Targeting the Electron Transport System for Enhanced Longevity

Damage to mitochondrial DNA (mtDNA) results in defective electron transport system (ETS) complexes, initiating a cycle of impaired oxidative phosphorylation (OXPHOS), increased reactive oxygen species (ROS) production, and chronic low-grade inflammation (inflammaging). This culminates in energy failure, cellular senescence, and progressive tissue degeneration. Rapamycin and metformin are the most extensively studied longevity drugs. Rapamycin inhibits mTORC1, promoting mitophagy, enhancing mitochondrial biogenesis, and reducing inflammation. Metformin partially inhibits Complex I, lowering reverse electron transfer (RET)-induced ROS formation and activating AMPK to stimulate autophagy and mitochondrial turnover. Both compounds mimic caloric restriction, shift metabolism toward a catabolic state, and confer preclinical-and, in the case of metformin, clinical-longevity benefits. More recently, small molecules directly targeting mitochondrial membranes and ETS components have emerged. Compounds such as Elamipretide, Sonlicromanol, SUL-138, and others modulate metabolism and mitochondrial function while exhibiting similarities to metformin and rapamycin, highlighting their potential in promoting longevity. The key question moving forward is whether these interventions should be applied chronically to sustain mitochondrial health or intermittently during episodes of stress. A pragmatic strategy may combine chronic metformin use with targeted mitochondrial therapies during acute physiological stress.

Inactivation of Laforin Phosphatase and Increased Glucose Uptake Underlie Glycogen Synthase-Mediated Neuronal Survival Under Oxidative Stress

Recent studies demonstrate that exposure of neurons to physiological stressors triggers glycogen synthase (GS) activation and glycogen synthesis as a transient cell survival mechanism. However, the mechanisms that regulate glycogen synthesis during stress and its role in neuronal physiology remain unclear. This study investigated the mechanisms that guide GS activation and glycogen accumulation under oxidative stress conditions as a model stressor. We use neuronal cell lines to demonstrate that hydrogen peroxide-induced oxidative stress activates GS and glycogen synthesis in neuronal cells. We further demonstrate that the stress-induced glycogen accumulation is dependent on the membrane localization of the Glut3 glucose transporters and increased glucose uptake during stress. The stress-induced activation of glycogen synthesis, however, is independent of intracellular glucose level, suggesting a parallel mechanism for activating GS and glucose uptake in neurons under physiological stress. We demonstrate that oxidative stress results in the inactivation of laforin phosphatase, leading to the membrane localization of Glut3 and activation of GS. Using the Drosophila model, we demonstrate that increased GS activity and concomitant glycogen accumulation are pro-survival mechanisms for neurons under oxidative stress. Our study thus offers novel insights into the pathways that regulate glycogen metabolism in neurons under oxidative stress and underscores their importance for neuronal survival.

Myricetin ameliorates the effects of hydrogen peroxide-induced oxidative stress in human mesenchymal stem cells: an ultrastructural and immunocytochemical study

The development of new strategies to raise the survival and viability of transplanted mesenchymal stem cells (MSCs) is very important for the therapeutic potential of stem cells. The natural flavonoid myricetin has anticancer, antioxidant, anti-inflammatory and antiapoptotic effects. The effects of myricetin on human umbilical cord-derived MSCs (HUC-MSCs) induced oxidative stress with hydrogen peroxide (H2O2) were evaluated by transmission electron microscopy (TEM) and immunocytochemistry (ICC) staining. Myricetin showed an increase in the number of live cells, a decrease in caspase-3 and tumor necrosis factor-α (TNF-α) ICC staining intensity, an increase in the translocase of the mitochondrial inner membrane 17 (TIM17) ICC staining intensity, and a decrease in degeneration of cell ultrastructure in TEM against oxidative stress damage in HUC-MSCs. The results suggest that myricetin prevents oxidative stress-induced apoptosis and inflammation in the HUC-MSCs. Myricetin can be combined with HUC-MSCs in cell culture and considered as a supportive alternative treatment option.

Enhanced functionality and migration of human gingival fibroblasts on vacuum ultraviolet light-treated titanium: An implication for mitigating cellular stress to improve peri-implant cellular reaction

PURPOSE

The maintenance of peri-implant health relies significantly on the integrity of the peri-implant seal, particularly vulnerable at the interface between implant abutment and soft tissue. Early healing stages around implants involve cellular exposure to oxidative stress. This study aimed to investigate whether vacuum ultraviolet (VUV)-treated titanium augments the growth and functionality of human gingival fibroblasts while mitigating cellular stress.

METHODS

Machined titanium plates underwent treatment with 172 nm VUV light for one minute, with untreated plates as controls. Human gingival fibroblasts were cultured on treated and untreated plates, and their behavior, growth, and functionality were assessed. Functionally impaired fibroblasts, treated with hydrogen peroxide, were also cultured on these titanium plates, and plate-to-plate transmigration ability was evaluated.

RESULTS

Fibroblasts on VUV-treated titanium exhibited a 50% reduction in intracellular reactive oxygen species production compared to controls. Additionally, glutathione, an antioxidant, remained undepleted in cells on VUV-treated titanium. Furthermore, the expression levels of inflammatory cytokines IL-1β and IL-8 decreased by 40-60% on VUV-treated titanium. Consequently, fibroblast attachment and proliferation doubled on VUV-treated titanium compared to those in the controls, leading to enhanced cell retention. Plate-to-plate transmigration assays demonstrated that fibroblasts migrated twice as far on VUV-treated surfaces compared to those in the controls. In particular, the transmigration ability, impaired in functionally impaired fibroblasts on the controls, was preserved on VUV-treated titanium.

CONCLUSIONS

VUV-treated titanium promotes the growth, function, and migration of human gingival fibroblasts by reducing cellular stress and enhancing antioxidative capacity. Notably, the transmigration ability significantly improved on VUV-treated titanium.

Exogenous Alpha-Ketoglutaric Acid Alleviates the Rabbit Dermal Papilla Cell Oxidative Damage Caused by Hydrogen Peroxide Through the ERK/Nrf2 Signaling Pathway

As an endogenous metabolite, α-ketoglutarate (AKG) exhibits potent antioxidant properties, yet its molecular mechanisms remain unclear. Dermal Papilla Cells (DPCs), functioning as the regulatory hub of hair follicle morphogenesis, serve as a pivotal model system for deciphering follicular functionality and regeneration mechanisms through their orchestration of signaling networks. Using a hydrogen peroxide (H2O2)-induced oxidative stress model in DPCs, we investigated AKG's protective effects. AKG attenuated H2O2-triggered reactive oxygen species (ROS) overproduction, restored mitochondrial membrane potential, and suppressed apoptosis-related protein dysregulation. It enhanced cellular stress resistance by increasing the Bcl-2/Bax ratio, boosting antioxidant levels, and inhibiting inflammation. Mechanistically, H2O2 activated the Nrf2 pathway, while AKG amplified Nrf2 nuclear translocation and expression. Crucially, ERK inhibition abrogated AKG-mediated Nrf2 regulation, intensifying ROS accumulation and cell death. These results identify the ERK/Nrf2 axis as central to AKG's antioxidative cytoprotection. This study advances AKG's therapeutic potential and deepens insights into its multifunctional roles.

Hydrogen peroxide-induced oxidative stress alters protein expression in two rat salivary acinar cell lines

OBJECTIVES

This study aimed to investigate the impact of hydrogen peroxide-induced oxidative stress on the protein expression profiles of submandibular and parotid acinar cells using a proteomic approach. We sought to evaluate how oxidative stress might contribute to salivary gland dysfunction and whether the two glands respond differently.

DESIGN

Immortalized rat parotid gland (PG) and submandibular gland (SMG) acinar epithelial cell lines were exposed to 50 µM and 150 µM hydrogen peroxide for 24 hr, followed by protein identification and quantification via liquid chromatography-mass spectrometry. Immunofluorescence microscopy and western blot analysis validated selected protein expressions, and cell viability was assessed using trypan blue exclusion assays.

RESULTS

Compared to controls, histone H4 expression increased in both cell types after hydrogen peroxide exposure, whereas voltage-dependent anion-selective channel 1, keratin 7, and keratin 8 increased only in parotid gland cells. Conversely, mitochondrial aldehyde dehydrogenase and kidney isoform glutaminase were downregulated in parotid gland cells. Basal expression of mitochondrial aldehyde dehydrogenase and catalase was higher in submandibular gland cells. At higher hydrogen peroxide concentrations, antioxidant proteins expression and cell viability were greater in submandibular gland cells compared to parotid gland cells.

CONCLUSIONS

Our results suggest that submandibular gland acinar cells exhibit greater resistance to oxidative stress compared to parotid gland cells, potentially due to distinct antioxidant and metabolic coping strategies. Understanding these gland-specific responses may contribute to future approaches to protect salivary glands from oxidative damage under pathological conditions.

Natural xanthones as modulators of the Nrf2/ARE signaling pathway and potential gastroprotective agents

Oxidative stress is implicated in the initiation, pathogenesis, and progression of various gastric inflammatory diseases (GID). The prevalence of these diseases remains a concern along with the increasing risks of adverse effects in current clinical interventions. Hence, new gastroprotective agents capable of inhibiting oxidative stress by modulating cellular defense systems such as the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway are critically needed to address these issues. A candidate to solve the present issue is xanthone, a natural compound that reportedly exerts gastroprotective effects via antioxidant, anti-inflammatory, and cytoprotective mechanisms. Moreover, xanthone derivatives were shown to modulate the Nrf2/ARE signaling pathway to counter oxidative stress in both in vitro and in vivo models. Thirteen natural xanthones have demonstrated the ability to modulate the Nrf2/ARE signaling pathway and have high potential as lead compounds for GID as indicated by their in vivo gastroprotective action-particularly mangiferin (2), α-mangostin (3), and γ-mangostin (4). Further studies on these compounds are recommended to validate the Nrf2 modulatory ability in relation to their gastroprotective action.

In Vivo Acute Toxicity and Therapeutic Potential of a Synthetic Peptide, DP1 in a Staphylococcus aureus Infected Murine Wound Excision Model

Bacterial infections at the surgical sites are one of the most prevalent skin infections that impair the healing mechanism. They account for about 20% of all types of infections and lead to approximately 75% of surgical-site infection-associated mortality. Several antibiotics, such as cephalosporins, fluoroquinolones, quinolones, penicillin, sulfonamides, etc., that are used to treat such wound infections not only counter infections but also disrupt the normal flora. Moreover, antibiotics, when used for a prolonged duration, may impair the formation of new blood vessels, delay collagen production, or inhibit the migration of certain cells involved in wound repair, leading to an impaired healing process. Therefore, there is a dire need for alternate therapeutic approaches against such infections. Antimicrobial peptides have gained considerable attention as a promising strategy to counter these pathogens and prevent the spread of infection. Recently, we have reported a designed peptide, DP1, and its broad-spectrum in vitro antimicrobial activity against Gram-positive and Gram-negative bacteria. In the present study, in vivo acute toxicity of DP1 was evaluated and even at a high dose (20 mg/kg body weight) of DP1, a 100% survival of mice was observed. Subsequently, a Staphylococcus aureus-infected murine wound excision model was established to assess the wound healing efficacy of DP1. The study revealed significant wound healing vis-a-vis attenuated S. aureus bioburden at the wound site and also controlled the oxidative stress depicting anti-oxidant activity as well. Healing of the infected wounds was also verified by histopathological examination. Based on the results of this study, it can be concluded that DP1 improves wound resolution despite infections and promotes the healing mechanism. Hence, DP1 holds compelling potential as a novel antimicrobial drug that requires further explorations in clinical platforms.

The cell origin of reactive oxygen species and its implication for evolutionary trade-offs

The allocation of resources in animals is shaped by adaptive trade-offs aimed at maximizing fitness. At the heart of these trade-offs, lies metabolism and the conversion of food resources into energy, a process mostly occurring in mitochondria. Yet, the conversion of nutrients to utilizable energy molecules (adenosine triphosphate) inevitably leads to the by-production of reactive oxygen species (ROS) that may cause damage to important biomolecules such as proteins or lipids. The 'ROS theory of ageing' has thus proposed that the relationship between lifespan and metabolic rate may be mediated by ROS production. However, the relationship is not as straightforward as it may seem: not only are mitochondrial ROS crucial for various cellular functions, but mitochondria are also actually equipped with antioxidant systems, and many extra-mitochondrial sources also produce ROS. In this review, we discuss how viewing the mitochondrion as a regulator of cellular oxidative homeostasis, not merely a ROS producer, may provide new insights into the role of oxidative stress in the reproduction-survival trade-off. We suggest several avenues to test how mitochondrial oxidative buffering capacity might complement current bioenergetic and evolutionary studies.

Dynamic PRDX S-acylation modulates ROS stress and signaling

Peroxiredoxins (PRDXs) are a highly conserved family of peroxidases that serve as the primary scavengers of peroxides. Post-translational modifications play crucial roles modulating PRDX activities, tuning the balance between reactive oxygen species (ROS) signaling and stress. We previously reported that S-acylation occurs at the "peroxidatic" cysteine (Cp) site of PRDX5 and that it inhibits PRDX5 activity. Here, we show that the PRDX family more broadly is subject to S-acylation at the Cp site of all PRDXs and that PRDX S-acylation dynamically responds to cellular ROS levels. Using activity-based fluorescent imaging with DPP-Red, a red-shifted fluorescent indicator for acyl-protein thioesterase (APT) activity, we also discover that the instigation of ROS-stress via exogenous H2O2 activates both the cytosolic and mitochondrial APTs, whereas epidermal growth factor (EGF)-stimulated endogenous H2O2 deactivates the cytosolic APTs. These results indicate that APTs help tune H2O2 signal transduction and ROS protection through PRDX S-deacylation.

Hydrogen Peroxide-Releasing Hydrogel-Mediated Cellular Senescence Model for Aging Research

Cellular senescence, a process that induces irreversible cell cycle arrest in response to diverse stressors, is a primary contributor to aging and age-related diseases. Currently, exposure to hydrogen peroxide is a widely used technique for establishing in vitro cellular senescence models; however, this traditional method is inconsistent, laborious, and ineffective in vivo. To overcome these limitations, we have developed a hydrogen peroxide-releasing hydrogel that can readily and controllably induce senescence in conventional 2-dimensional cell cultures as well as advanced 3-dimensional microphysiological systems. Notably, we have established 2 platforms using our hydrogen peroxide-releasing hydrogel for investigating senolytics, which is a promising innovation in anti-geronic therapy. Conclusively, our advanced model presents a highly promising tool that offers a simple, versatile, convenient, effective, and highly adaptable technique for inducing cellular senescence. This innovation not only lays a crucial foundation for future research on aging but also markedly accelerates the development of novel therapeutic strategies targeting age-related diseases.

Elevated reactive oxygen species can drive the alternative lengthening of telomeres pathway in ATRX-null cancers

The alternative lengthening of telomeres (ALT) pathway is a telomerase-independent mechanism for immortalization in cancer cells and is commonly activated in low-grade and high-grade glioma, as well as osteosarcoma. The ALT pathway can be activated under various conditions and has often been shown to include mutational loss of ATRX. However, this is insufficient in isolation and so other cellular event must also be implicated. It has been shown that excessive accumulation of DNA:RNA hybrid structures (R-loops) and/or formation of DNA-protein crosslinks (DPCs) can be other important driving factors. The underlying cellular events leading to R-loop and DPC formation in ALT cancer cells to date remain unclear. Here, we demonstrate that excessive cellular reactive oxygen species (ROS) is an important causative factor in the evolution of ALT-telomere maintenance in ATRX-deficient glioma. We identified three sources of elevated ROS in ALT-positive gliomas: co-mutation of SETD2, downregulation of DRG2, and hypoxic tumour microenvironment. We demonstrate that elevated ROS leads to accumulation of R-loops and, crucially, resolution of R-loops by the enzyme RNase H1 prevents ALT pathway activity in cells exposed to elevated ROS. Further, we found a possible causal link between the formation of R-loops and the accumulation of DPCs, in particular, formation of TOP1 complexes covalently linked to DNA (Top1cc). We also demonstrate that elevation of ROS can trigger over-activity of the ALT pathway in osteosarcoma and glioma cell lines, resulting in excessive DNA damage and cell death. This work presents important mechanistic insights into the endogenous origin of excessive R-loops and DPCs in ALT-positive cancers, as well as highlighting potential novel therapeutic approaches in these difficult-to-treat cancer types.

Dispensable regulation of brain development and myelination by the immune-related protein Serpina3n

Serine protease inhibitor clade A member 3n (Serpina3n) or its human orthologue SERPINA3 is a secretory immune-related molecule produced primarily in the liver and brain under homeostatic conditions and up-regulated in response to system inflammation. Yet, it remains elusive regarding its cellular identity and physiological significance in the development of the postnatal brain. Here, we reported that oligodendroglial lineage cells are the major cell population expressing Serpina3n protein in the postnatal murine CNS. Using loss-of-function genetic tools, we found that Serpina3n conditional knockout (cKO) from Olig2-expressing cells does not significantly affect cognitive and motor functions in mice. Serpina3n depletion does not appear to interfere with oligodendrocyte differentiation and developmental myelination nor affects the population of other glial cells and neurons in vivo. Interestingly, Serpina3n is significantly up-regulated in response to oxidative stress and its deficiency alleviates oxidative injury and diminishes cell senescence of oligodendrocytes in vitro. Together, our data suggest that the immune-related molecule Serpina3n plays a minor role in neural cell development under homeostasis, yet it primes oligodendrocytes for CNS insults and regulates oligodendrocyte health under injured conditions. Our findings raise the interest in pursuing its functional significance in the CNS under disease/injury conditions.

Bioactivity of Talisia esculenta extracts: Antioxidant and anti-inflammatory action on RAW 264.7 macrophages and protective potential on the zebrafish exposed to oxidative stress inducers

ETHNOPHARMACOLOGICAL RELEVANCE

Talisia esculenta is a fruit tree commonly found in various regions of Brazil. Its fruit is consumed by the local population, and the leaves are used in infusions within traditional Brazilian medicine. These infusions are employed to alleviate pathological conditions such as rheumatic diseases and hypertension, both of which are strongly linked to oxidative stress and chronic inflammation. The investigation of plant extracts represents a promising field of research, as bioactive compounds abundant in plants exhibit pharmacological effects against a variety of pathological conditions.

AIM OF THE STUDY

To investigate the antioxidant, anti-inflammatory activities, and toxicity of the infusion and hydroethanolic extracts of T. esculenta leaves (IF and HF) and fruit peels (IC and HC).

MATERIALS AND METHODS

Initially, the cytotoxicity and the effects of the extracts on oxidative stress in RAW264.7 macrophages were assessed through exposure to H₂O₂, as well as their impact on NO production in RAW264.7 macrophages exposed to LPS. Additionally, the toxicity and ROS production in zebrafish larvae were evaluated using two oxidative stress inducers: H₂O₂ and CuSO₄ combined with ascorbate.

RESULTS

The MTT assay indicated that the extracts exhibited low cytotoxicity, with HF and IF demonstrating protective effects against H₂O₂ exposure. HC reduced NO production in macrophages by 30%. The zebrafish analysis showed that all four T. esculenta extracts (100 μg/mL) were non-toxic, as they did not affect the survival, heart rate, or body size of the animals. Furthermore, all extracts were capable of reducing ROS levels in zebrafish larvae exposed to the H₂O₂ stressor. Notably, ROS reduction by HF, IF, and HC extracts exceeded 50% compared to the positive control (H₂O₂ alone). T. esculenta extracts also demonstrated a significant ability to reduce ROS levels in zebrafish larvae exposed to CuSO₄, with a 70% reduction observed for leaf extracts and over 30% for fruit peel extracts.

CONCLUSION

This study demonstrated that T. esculenta extracts exhibit significant activity against oxidative damage and contain components with anti-inflammatory properties. Among the extracts, those obtained from leaves were the most effective in providing oxidative protection, supporting the traditional use of leaf infusions.

Oxidative Stress Enhances Rubella Virus Infection in Immortalized Human First-Trimester Trophoblasts

Rubella infection (RuV) during early pregnancy is a known cause of congenital rubella syndrome (CRS). However, the mechanisms by which the virus crosses the placenta and infects the fetus are not fully understood. It has been known that various kinds of cell stresses can occur during the placenta formation. Previously, we demonstrated that low-glucose-induced endoplasmic reticulum stress could drastically enhance RuV infection in immortalized human first-trimester trophoblast cells. In this study, we investigated the roles of oxidative stress in RuV infection in these cells. Oxidative stress was induced in Swan.71 cells by culturing them in medium containing hydrogen peroxide (H2O2) in various concentrations and durations (50 µM or 100 µM for 24 h, or 150 µM for 1 h). RuV infection with a clinical strain was performed 24 h post-treatment, and capsid proteins were visualized at 24 and 48 h post-infection (hpi) using flow cytometry (FCM) and fluorescence microscopy (IF), respectively. The findings demonstrated that oxidative stress significantly enhanced RuV infection, as evidenced by FCM analysis, showing a twofold increase in infection rate, and confirmed by IF assay. Additionally, significantly increased intracellular viral replication was observed at 3 dpi. These findings suggest that oxidative stress during early pregnancy may promote the maternal-to-fetal transmission of rubella, contributing to the development of CRS.

The protective effect of Argan oil and its main constituents against xenobiotics-induced toxicities

BACKGROUND

Argan oil (AO) is a vegetable oil extracted from the fruits of Argania spinosa L. tree, belonging to the Sapotaceae family, primarily found in Morocco. Research studies have demonstrated that AO exhibits diverse pharmacological properties, including antioxidant, antimicrobial, anticancer, antiinflammatory, antidiabetic, antihypercholesterolemic, antiatherogenic, and immunomodulatory effects. These effects are attributed to its main constituents, including oleic acid, linoleic acid, γ-tocopherol, α-tocopherol, and ferulic acid.

OBJECTIVE

This review aimed to present the protective role of AO and its main constituents against xenobiotics-induced toxicities.

MATERIAL AND METHODS

Based on results from various in vitro and in vivo investigations published in the main scientific databases, the beneficial action of AO against xenobiotics-induced toxicities was analyzed.

RESULTS

AO and its main constituents have reduced neurotoxicity, hepatotoxicity, nephrotoxicity, pneumotoxicity, thyroid toxicity, hematotoxicity, immunotoxicity, genotoxicity, and colon toxicity induced by different natural and chemical xenobiotics. Different mechanisms of action are involved in these effects, including enhancement of antioxidant defense, reduction of oxidative stress, modulation of inflammation, stimulation of fatty acid oxidation, suppression of apoptosis, regulation of miRNAs expression, elevation of acetylcholinesterase activity, activation of Krebs cycle enzymes, and restoration of mitochondrial function.

CONCLUSION

The study shows clearly the beneficial effect of Argan oil against xenobiotics-induced toxicities was analyzed. However, clinical trials are necessary to verify the protective effects of this oil in human intoxications caused by both natural and chemical xenobiotics.

Increased glucose concentration modifies TGF-β1 and NFκB signaling pathways in aniridia limbal fibroblasts, in vitro

To determine the impact of increased glucose concentration on gene expression of primary healthy human limbal fibroblasts (LFCs) and congenital aniridia human limbal fibroblasts (AN-LFCs), in vitro. LFCs (n = 8) and AN-LFCs (n = 8) were isolated and cultured in serum containing DMEM, including either normal glucose (17.5 mM) or increased glucose (70 mM) concentration for 48h or 72h, respectively. mRNA and protein expression of transforming growth factor beta 1 (TGF-β1), alpha-smooth muscle actin (ACTA)2A1, SMAD 2/3, hypoxia markers such as nuclear factor kappa B (NFκB), inducible nitric oxide synthase (iNOS), hypoxia-inducible factor 1-alpha (HIF-1ɑ), oxidative stress markers such as nuclear factor erythroid 2-related factor 2 (Nrf2) and Catalase (CAT) were analyzed using qPCR and Western blot. In 70 mM glucose concentration medium for 48 h, TGF-β1 mRNA expression was significantly lower (p = 0.001, p < 0.001), Nrf2 (p = 0.001, p = 0.001) and CAT (p = 0.001, p = 0.001) mRNA expression was significantly higher in LFCs and AN-LFCs, than using 17.5 mM glucose concentration medium. In addition, in 70 mM glucose concentration medium for 48 h, SMAD 2, SMAD 3, NFκB, HIF-1ɑ mRNA expression was significantly lower in AN-LFCs, than in 17.5 mM glucose concentration medium (p = 0.003, p = 0.002, p = 0.008, p = 0.020). At this time-point in 70 mM glucose concentration medium, at protein level, TGF-β1, SMAD2/3 and NFκB were significantly lower in AN-LFCs, than in 17.5 mM glucose concentration medium (p = 0.041, p = 0.002, p = 0.012). In 70 mM glucose concentration medium for 72h, TGF-β1 was significantly higher (p < 0.001, p < 0.001) and Nrf2 (p = 0.001, p = 0.001) and CAT (p < 0.001, p < 0.001) mRNA were significantly lower in LFCs and AN-LFCs, than in 17.5 mM glucose concentration medium. At this time-point, in 70 mM glucose concentration medium, NFκB mRNA was significantly higher (p < 0.001) in LFCs, than in 17.5 mM glucose concentration DMEM medium. In 70 mM glucose concentration medium for 72 h, TGF-β1 and NFκB protein were significantly lower in AN-LFCs, than in 17.5 mM glucose concentration medium (p < 0.001, p < 0.001). Our study confirmed that high glucose concentration has an impact on TGF-β1 and NFκB signaling both in AN-LFCs and LFCs. These findings highlight that prolonged exposure to high glucose levels may contribute to cellular stress and dysfunction in LFCs and AN-LFCs.

Facts, Dogmas, and Unknowns About Mitochondrial Reactive Oxygen Species in Cancer

Cancer metabolism is sustained both by enhanced aerobic glycolysis, characteristic of the Warburg phenotype, and oxidative metabolism. Cell survival and proliferation depends on a dynamic equilibrium between mitochondrial function and glycolysis, which is heterogeneous between tumors and even within the same tumor. During oxidative phosphorylation, electrons from NADH and FADH2 originated in the tricarboxylic acid cycle flow through complexes of the electron transport chain. Single electron leaks at specific complexes of the electron transport chain generate reactive oxygen species (ROS). ROS are a concentration-dependent double-edged sword that plays multifaceted roles in cancer metabolism. ROS serve either as signaling molecules favoring cellular homeostasis and proliferation or damage DNA, protein and lipids, causing cell death. Several aspects of ROS biology still remain unsolved. Among the unknowns are the actual levels at which ROS become cytotoxic and if toxicity depends on specific ROS species or if it is caused by a cumulative effect of all of them. In this review, we describe mechanisms of mitochondrial ROS production, detoxification, ROS-induced cytotoxicity, and the use of antioxidants in cancer treatment. We also provide updated information about critical questions on the biology of ROS on cancer metabolism and discuss dogmas that lack adequate experimental demonstration. Overall, this review brings a comprehensive perspective of ROS as drivers of cancer progression, inducers of cell death, and the potential use of antioxidants as anticancer therapy.

Investigation of Impact of Oxidative Stress on Human Periodontal Ligament Cells Exposed to Static Compression

Oxidative stress (OS) is a common feature of many inflammatory diseases, oral pathologies, and aging processes. The impact of OS on periodontal ligament cells (PDLCs) in relation to oral pathologies, including periodontal diseases, has been investigated in different studies. However, its impact on orthodontic tooth movement (OTM) remains poorly understood. This study used an in vitro model with human PDLCs previously exposed to H2O2 to investigate the effects of OS under a static compressive force which simulated the conditions of OTM. Human PDLCs were treated with varying concentrations of H2O2 to identify sub-lethal doses that affected viability minimally. To mimic compromised conditions resembling OTM under OS, the cells were pretreated with the selected H2O2 concentrations for 24 h. Using an in vitro loading model, a static compressive force (2 g/cm2) was applied for an additional 24 h. The cell viability, proliferation, and cytotoxicity were evaluated using live/dead and resazurin assays. Apoptosis induction was assessed based on caspase-3/7 activity. The gene expression related to bone remodeling (RUNX2, TNFRSF11B/OPG, BGLAP), inflammation (IL6, CXCL8/IL8, PTGS2/COX2), apoptosis (CASP3, CASP8), and autophagy (MAP1LC3A/LC3, BECN1) was analyzed using RT-qPCR. This study suggests an altering effect of previous OS exposure on static-compression-related mechanosensing. Further research is needed to fully elucidate these mechanisms.

Astaxanthin Prevents Oxidative Damage and Cell Apoptosis Under Oxidative Stress Involving the Restoration of Mitochondrial Function

Oxidative stress (OS) is one of the factors that result in cell damage and the development of neurological diseases such as Alzheimer's disease (AD). Astaxanthin (ASTA), a natural compound known for its potent antioxidant properties, shows the biological activities in anti-apoptosis and antitumor. However, its specific mechanism on mitochondrial function remains unclear. This study investigated the effects of ASTA on regulation in mitochondrial function and cell apoptosis under OS induced by hydrogen peroxide (H2O2). The results demonstrated that ASTA (0.1, 1, 10 μmol/L) protected cells form H2O2-induced cell damage and apoptosis through mitochondrial pathway. ASTA significantly reduced H2O2-induced mitochondrial dysfunctions and restored the intracellular reactive oxygen species (ROS), mitochondrial membrane potential, and respiratory capacity. These findings suggest that ASTA's antioxidant properties can benefit neurons by maintaining mitochondrial function and alleviating oxidative damage and cell apoptosis induced by H2O2.

Untargeted metabolomics unravels the effects of ginkgolide B-producing Lactiplantibacillus plantarum and co-induced fermentation of ginkgo kernel juice and their underlying vascular endothelial cell protection activity

The objective of this study was to investigate the fermentation mechanism of ginkgo kernel juice (GKJ) under unfermented (Group A), Ginkgolide B (GB)-producing Lactiplantibacillus plantarum fermented (Group B), and co-induced fermented (Group C) conditions. The conditions were optimized and further evaluated for their vascular endothelial cell protective effects in vitro. The co-induced fermented GKJ group extensively promoted GB and total phenol contents, reaching 109.94 and 599.57 μg/mL, respectively. While pH declined from 5.90 to 3.42 during fermentation, the highest total viable count (8.85 log CFU/mL) was detected at 16 h in the L. plantarum group. The co-induced group recorded the highest total phenol contents (594.05 μg/mL) and markedly induced the survival rate, reactive oxygen species formation, and lactate dehydrogenase assay cytotoxicity of H2O2-induced human umbilical vein endothelial cells. An untargeted metabolomics analysis identified 2633 metabolites in the groups. The principal component and orthogonal partial least squares discriminant score plots showed a clear metabolite distinction among the fermentation groups. From the Kyoto Encyclopedia of Genes and Genomes analysis, 309 differential accumulated metabolites (DAMs) were up-regulated and 604 were down-regulated in the A vs. B group, while 702 downregulated and 304 upregulated DAMs were exhibited in the B vs. C group. These DAMs were primarily lipids and lipid-like molecules, organic acids and their derivatives, organoheterocyclic compounds, organic oxygen compounds, benzenoids, phenylpropanoids and polyketides, and unclassified compounds at the superclass level. Overall, the results indicated that L. plantarum and co-induced fermentation improved the cell protection efficacy of GKJ, showing excellent potential for drug delivery applications.

Navigating the redox landscape: reactive oxygen species in regulation of cell cycle

Objectives: To advance our knowledge of disease mechanisms and therapeutic options, understanding cell cycle regulation is critical. Recent research has highlighted the importance of reactive oxygen species (ROS) in cell cycle regulation. Although excessive ROS levels can lead to age-related pathologies, ROS also play an essential role in normal cellular functions. Many cell cycle regulatory proteins are affected by their redox status, but the precise mechanisms and conditions under which ROS promote or inhibit cell proliferation are not fully understood.Methods: This review presents data from the scientific literature and publicly available databases on changes in redox state during the cell cycle and their effects on key regulatory proteins.Results: We identified redox-sensitive targets within the cell cycle machinery and analysed different effects of ROS (type, concentration, duration of exposure) on cell cycle phases. For example, moderate levels of ROS can promote cell proliferation by activating signalling pathways involved in cell cycle progression, whereas excessive ROS levels can induce DNA damage and trigger cell cycle arrest or cell death.Discussion: Our findings encourage future research focused on identifying redox-sensitive targets in the cell cycle machinery, potentially leading to new treatments for diseases with dysregulated cell proliferation.

The Effect of Monobenzone Cream on Oxidative Stress and Its Relationship With Serum Levels of IL-1β and IL-18 in Vitiligo Patients

BACKGROUND

Monobenzyl ether hydroquinone (MEBHQ) is a cream that promotes the spread and evenness of skin patches in vitiligo. Our aim was to investigate the oxidative and inflammatory effects of this cream on vitiligo patients consuming MEBHQ.

METHODS

A case-control study was conducted with three groups of 30 people from the control group, vitiligo patients before and after treatment. The percentage of vitiligo spots was determined by a specialist doctor. The levels of biochemical factors, oxidative stress profile and inflammatory factors were measured by enzymatic, colorimetric and ELISA methods, respectively.

RESULTS

Vitiligo patients showed a high level of inflammation and oxidative stress compared to healthy people. Although after 3 months of using MBEHQ cream, the percentage of skin spots in vitiligo patients increased from an average of 63%-91% and the skin color became almost uniform, but it still increased the level of oxidative stress and inflammation in these patients. Although the level of oxidative stress increased significantly in these patients, there was no significant increase in the level of malondialdehyde. The lack of significant differences in the levels of biochemical factors between healthy people and vitiligo patients before and after using the treatment shows the absence of side effects.

CONCLUSION

The use of MBEHQ increased the size of skin spots and uneven skin color in vitiligo patients. Although MBEHQ did not show side effects such as diabetes, liver and kidney diseases, it increased the levels of oxidative stress and inflammatory cytokines, which needs further study.

Melatonin-based priming of stem cells to alleviate oxidative stress

Stem cell expansion in vitro and transplantation in the cytokine-rich proinflammatory milieu in the injured tissue generate immense oxidative stress that interferes with the cells' survival, stemness, and repairability. Stem cell priming has gained popularity to overcome these issues. Given melatonin's oxidative-scavenging properties, Gu et al have used periodontal ligament stem cells cultured under oxidative stress as an in vitro model to study the cytoprotective effects of melatonin. Our letter to the editor delves into melatonin-induced stem cell priming and the underlying molecular mechanism, focusing on the intriguing role of Yes-associated protein signaling in alleviating oxidative stress. We stress the importance of understanding the distinction between in vitro and in vivo oxidative stress conditions, a crucial aspect of stem cell research that invokes a sense of critical thinking in the readership. The study by Gu et al presents a novel approach to oxidative stress management, offering exciting possibilities for future research and applications.

The Potential Protective Role of Ascorbic Acid Against Testicular Toxicity Induced by Fluoxetine in Male Wistar Rats

Background

Fluoxetine (FLX) is a Selective Serotonin Re-uptake Inhibitor (SSRI) commonly used as a first-line treatment for depression, anxiety, and mood disorders. It can cause infertility in the male reproductive system through the release of Reactive Oxygen Species (ROS). This study aimed to evaluate the testiculo-protective potential of ascorbic acid against fluoxetine-induced spermatotoxicity in male Wistar rats.

Methods

This study assessed Vitamin C's effect on male fertility in fluoxetine-treated Wistar rats. Thirty rats (130 ± 40 g) were divided into six groups (n=5): Control (distilled water), fluoxetine 20 mg/kg, Vitamin C 100 mg/kg, fluoxetine 20 mg/kg + Vitamin C 50 mg/kg, fluoxetine 20 mg/kg + Vitamin C 100 mg/kg, and fluoxetine 20 mg/kg + Vitamin C 150 mg/kg. Treatments were administered daily via oral gavage for 60 days, followed by assessments of testicular weight, semen analysis, oxidative stress biomarkers (CAT and GPx), and histomorphology. The data was analyzed using one-way ANOVA and Turkey's post-hoc multiple comparison test, reporting as mean±SEM using The GraphPad Prism version 6.0 for Windows, with significance set at p<0.05.

Results

Vitamin C, administered particularly at higher doses, significantly increased body weight, testicular weight, and antioxidant enzyme levels (glutathione peroxidase and catalase) while improving fertility parameters such as sperm count, motility, and viability in treated rats (P<0.05). Fluoxetine alone led to a significant reduction (P<0.05) in these parameters, but the combination with Vitamin C mitigated these effects. Histological analysis showed improved testicular structure in Vitamin C-treated groups, highlighting its protective role against fluoxetine-induced testicular damage.

Conclusion

Ascorbic acid has testiculoprotective potential in fluoxetine-induced spermatotoxicity, mainly owing to its antioxidant properties.

Flavonoid Fisetin Alleviates Ovarian Aging of Laying Chickens by Enhancing Antioxidant Capacity and Glucose Metabolic Homeostasis

Oxidative stress is a crucial factor contributing to ovarian follicular atresia and an imbalance in ovarian energy metabolism in poultry, leading to decreased laying performance in aging hens. This study aimed to investigate the effects of a natural flavonoid, fisetin, on laying performance, ovarian redox status, and energy metabolism in laying chickens. The results showed that dietary fisetin supplementation improved egg production and eggshell quality in aging laying chickens, reduced follicular atresia rate, promoted ovarian cell proliferation, elevated serum estrogen and progesterone levels, restored ovarian antioxidant capacity, and improved energy metabolism. Furthermore, fisetin treatment increased the activity of antioxidant enzymes by inhibiting NF-κB signaling and COX-2 expression while promoting SIRT1 expression in the H2O2-induced small white follicle (SWF). Additionally, fisetin significantly enhanced the anti-apoptotic capacity of SWF and promoted glucose catabolism by activating the AKT and JNK signaling pathways. In summary, fisetin supplementation can alleviate ovarian oxidative stress in aging laying chickens by upregulating SIRT1 expression and inhibiting NF-κB signaling. The activation of AKT and JNK signaling pathways by fisetin contributes to the balance of energy metabolism and promotion of follicular development in the ovaries of aging laying chickens, thereby retarding ovarian aging in poultry production.

Antioxidant, neuroprotective, and neuroblastoma cells (SH-SY5Y) differentiation effects of melanins and arginine-modified melanins from Daedaleopsis tricolor and Fomes fomentarius

BACKGROUND

Microbial melanins possess a broad spectrum of biological activities. However, there is little understanding of their neuroprotective and neuronal cell differentiation properties. This study aimed to extract, purify, and modify melanins from two medicinal fungi (Daedaleopsis tricolor and Fomes fomentarius), and to evaluate their antioxidant activity, as well as their cell protective ability against neurotoxins. In addition, the study also investigated the feasibility of combining melanins or modified melanins with retinoic acid (RA) to induce neuronal differentiation.

METHODS

Melanin was extracted and purified using alkaline acid-based methods. Antioxidant activities and neuroprotective effects were evaluated using the DPPH (1,1-diphenyl-2-picrylhydrazyl) and MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assays, respectively. In addition, morphological changes of SH-SY5Y cells were recorded by using a Pannoramic MIDI scanner.

RESULTS

All melanins and arginine-modified melanins displayed mild DPPH scavenging activities, which were statistically lower than that of ascorbic acid (p < 0.05). In terms of neuroprotection, both melanins and arginine-modified melanins exhibited significant cell protection against H2O2 after 24 h exposure (p < 0.05). Notably, there is no significant difference between F. fomentarius melanin and its modified form as they both increased cell viability by about 20%. Contrarily, while D. tricolor melanin enhanced the cell viability with 16%, its modified form increased the cell viability with 21%. These activities, however, are significantly lower than the positive control (N-acetylcysteine, p < 0.05). Regarding MPTP, only the arginine-modified melanins of the two fungi significantly protected the cells after 24 h exposure to the toxin (p < 0.05). Specifically, F. fomentarius and D. tricolor modified melanins enhanced the cell viability with 10.2% and 11.1%, respectively, whereas that of the positive control was 13.2%. Interestingly, combining RA (10 µM) with 20 µg/mL of either F. fomentarius, or especially D. tricolor arginine-modified melanin, significantly promoted neuroblastoma cell differentiation into mature neuronal cells compared to using RA alone (p < 0.05).

CONCLUSIONS

The arginine-modified melanins of D. tricolor and F. fomentarius have potential for neuroprotection against Parkinsonian neurotoxins. In addition, the arginine-modified melanin of D. tricolor may serve as an excellent material for research in neuroblastoma treatment.

Utilizing the apical-out enteroids in vitro model to investigate intestinal glucose transport, barrier function, oxidative stress, and inflammatory responses in broiler chickens

Introduction

Conventional 2D intestinal epithelial cell lines have been widely used in investigating intestinal functions, yet with limitations in recapitulating the in vivo gut physiology of chickens. A recently established chicken enteroid model with apical-out nature and the presence of leukocyte components represents intestinal mucosal functions. The objectives of this study were to 1) evaluate basic gut nutrient transport and barrier functions in this model and 2) identify the model's effectiveness in studying inflammation and oxidative stress responses.

Methods

Enteroids were generated from individual villus units isolated from the small intestine of Cobb500 broiler embryos. Enteroid viability, morphology, and epithelial cell markers were monitored; barrier function was evaluated based on the permeability to fluorescein isothiocyanate-dextran (FD4) with or without EDTA and lipopolysaccharide (LPS) challenges; nutrient transport was evaluated by fluorescence-labeled glucose (2NBD-G) with or without transporter blockade; the oxidative status was indicated by reactive oxygen species (ROS). Inflammatory and oxidative challenges were induced by LPS and menadione treatment, respectively. Selected marker gene expressions, including tight junction proteins (CLDN-1, CLDN-2, ZO-1, and OCCL), epithelial cell markers (Lgr-5, LYZ, and MUC-2), cytokines (IL-1β, IL-6, IL-8, IL-10, TNF-α, and INF-γ), and antioxidant enzymes (Nrf-2, catalase, and SOD), were determined by using RT-qPCR. Data were analyzed by one-way ANOVA among treatment groups.

Results

Enteroid cell activity was stable from day (d) 2 to d 6 and declined at d 7. Epithelial cell marker and cytokine expressions were stable from d 4 to d 6. FD4 permeability was increased after the EDTA treatment (P ≤ 0.05). Transporter-mediated 2NBD-G absorption was observed, which was reduced with glucose transporter blockade (P ≤ 0.05). Enteroids showed classic responses to LPS challenges, including upregulated gene expressions of IL-1β and IL-6, downregulated gene expressions of ZO-1 and OCCL, and increased FD4 permeability (P ≤ 0.05). Enteroids showed increased ROS generation (P ≤ 0.05) in response to oxidative stress.

Discussion

In conclusion, this apical-out enteroid model is a stable alternative in vitro model that exhibits intestinal barrier, nutrient transport, oxidation, and inflammation functions. With this enteroid model, we developed two challenge protocols for evaluating intestinal functions under oxidative stress and inflammation conditions.

Dual isotope labelling combined with multi-omics analysis revealing the N2O source evolution in aerobic biological systems driven by salinity gradient

Salinity is considered a major factor influencing nitrous oxide (N2O) emissions from biochemical treatment of high-salinity wastewater, but its mechanism has not been thoroughly investigated. In this study, we investigated the effects of salinity on N2O emissions under aerobic conditions. As salinity rose from 0.66 % to 3.66 %, N2O emission flux first increased and then decreased, while the emission factor (EF) consistently increased, likely due to significant inhibition of nitrification at 3.66 % salinity. Nitrogen‑oxygen dual isotope labeling experiments demonstrated that the dominant N2O production pathway shifted with salinity: from nitrifier nitrification (NN, 36.07 %-40.97 %) at low salinity (0.66 %, 1.66 %), to nitrification-coupled denitrification (NCD, 51.67 %) at 2.66 %, and to nitrifier denitrification (ND, up to 80.81 %) at the salinity of 3.66 %. From the changes in bacterial relative abundances and expressions of 4 key functional genes (amoA, hao, nor, and nosZ) revealed by metatranscriptomic sequencing, Nitrosomonas, unclassified Rhodospirillales, and Nitrospira were identified as key contributors to NN, NCD, and ND pathways, respectively, as salinity increased. We also found that the differential expressed genes and metabolites involved in energy metabolism, oxidative phosphorylation, and metabolism of amino acids, pyrimidines, and nucleotides may affect N-cycling bacteria, thereby influencing nitrogen conversion and salinity tolerance as well. This study sheds light on nitrification process in response to salinity stress and offers insights for mitigating greenhouse gas emissions from high-salinity wastewater treatment.

The Arabidopsis thaliana ecotype Ct-1 achieves higher salt tolerance relative to Col-0 via higher tissue retention of K+ and NO3. JOURNAL OF PLANT PHYSIOLOGY 2024;302:154321. [PMID: 39116627 DOI: 10.1016/j.jplph.2024.154321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Agriculture is vital for global food security, and irrigation is essential for improving crop yields. However, irrigation can pose challenges such as mineral scarcity and salt accumulation in the soil, which negatively impact plant growth and crop productivity. While numerous studies have focused on enhancing plant tolerance to high salinity, research targeting various ecotypes of Arabidopsis thaliana has been relatively limited. In this study, we aimed to identify salt-tolerant ecotypes among the diverse wild types of Arabidopsis thaliana and elucidate their characteristics at the molecular level. As a result, we found that Catania-1 (Ct-1), one of the ecotypes of Arabidopsis, exhibits greater salt tolerance compared to Col-0. Specifically, Ct-1 exhibited less damage from reactive oxygen species (ROS) than Col-0, despite not accumulating antioxidants like anthocyanins. Additionally, Ct-1 accumulated more potassium ions (K+) in its shoots and roots than Col-0 under high salinity, which is crucial for water balance and preventing dehydration. In contrast, Ct-1 plants were observed to accumulate slightly lower levels of Na+ than Col-0 in both root and shoot tissues, regardless of salt treatment. These findings suggest that Ct-1 plants achieve high salinity resistance not by extruding more Na+ than Col-0, but rather by absorbing more K+ or releasing less K+. Ct-1 exhibited higher nitrate (NO3-) levels than Col-0 under high salinity conditions, which is associated with enhanced retention of K+ ions. Additionally, genes involved in NO3- transport and uptake, such as NRT1.5 and NPF2.3, showed higher transcript levels in Ct-1 compared to Col-0 when exposed to high salinity. However, Ct-1 did not demonstrate significantly greater resistance to osmotic stress compared to Col-0. These findings suggest that enhancing plant tolerance to salt stress could involve targeting the cellular processes responsible for regulating the transport of NO3- and K+. Overall, our study sheds light on the mechanisms of plant salinity tolerance, emphasizing the importance of K+ and NO3- transport in crop improvement and food security in regions facing salinity stress.

Sea cucumber-derived extract can protect skin cells from oxidative DNA damage and mitochondrial degradation, and promote wound healing

Our skin serves as the primary barrier against external environmental insults, the latter of which can cause oxidative stress within cells, while various bioactive peptides sourced from natural resources hold promise in protecting cells against such oxidative stress. In this study, we investigate the efficacy of a low molecular weight extract from the sea cucumber Apostichopus japonicus, denoted as Sample-P, in facilitating cell migration and wound healing under oxidative stress conditions in skin cells. The naturally derived compound is a highly complex mix of peptides exhibiting antioxidative properties, as highlighted through liquid chromatography-mass spectrometry peptide screening and an in vitro antioxidant assay. Our results demonstrate that Sample-P is capable of promoting cell migration while preventing severe stress responses such as visible through mTOR expression. To further identify the molecular pathways underpinning the overall protective mechanism of Sample-P, we have utilised a proteomics approach. Our data reveal that Sample-P regulates protein expression associated with ribosomal pathways, glycolysis/gluconeogenesis and protein processing in the endoplasmic reticulum (ER), which help in preserving DNA integrity and safeguarding cellular organelles, such as mitochondria and the ER, under oxidative stress conditions in skin cells. In summary, in the presence of H2O2, Sample-P exhibits antioxidative properties at both molecular and cellular levels, rendering it a promising candidate for topical skin treatment to wound healing and to address age-related skin conditions.

Nano- and Micro-Platforms in Therapeutic Proteins Delivery for Cancer Therapy: Materials and Strategies

Proteins have emerged as promising therapeutics in oncology due to their great specificity. Many treatment strategies are developed based on protein biologics, such as immunotherapy, starvation therapy, and pro-apoptosis therapy, while some protein biologics have entered the clinics. However, clinical translation is severely impeded by instability, short circulation time, poor transmembrane transportation, and immunogenicity. Micro- and nano-particles-based drug delivery platforms are designed to solve those problems and enhance protein therapeutic efficacy. This review first summarizes the different types of therapeutic proteins in clinical and research stages, highlighting their administration limitations. Next, various types of micro- and nano-particles are described to demonstrate how they can overcome those limitations. The potential of micro- and nano-particles are then explored to enhance the therapeutic efficacy of proteins by combinational therapies. Finally, the challenges and future directions of protein biologics carriers are discussed for optimized protein delivery.

GdVO4:Eu3+ and LaVO4:Eu3+ Nanoparticles Exacerbate Oxidative Stress in L929 Cells: Potential Implications for Cancer Therapy

The therapeutic potential of redox-active nanoscale materials as antioxidant- or reactive oxygen species (ROS)-inducing agents was intensely studied. Herein, we demonstrate that the synthesized and characterized GdVO4:Eu3+ and LaVO4:Eu3+ nanoparticles, which have been already shown to have redox-active, anti-inflammatory, antibacterial, and wound healing properties, both in vitro and in vivo, worsen oxidative stress of L929 cells triggered by hydrogen peroxide or tert-butyl hydroperoxide (tBuOOH) at the concentrations that are safe for intact L929 cells. This effect was observed upon internalization of the investigated nanosized materials and is associated with the cleavage of caspase-3 and caspase-9 without recruitment of caspase-8. Such changes in the caspase cascade indicate activation of the intrinsic caspase-9-dependent mitochondrial but not the extrinsic death, receptor-mediated, and caspase-8-dependent apoptotic pathway. The GdVO4:Eu3+ and LaVO4:Eu3+ nanoparticle-induced apoptosis of oxidatively compromised L929 cells is mediated by ROS overgeneration, Ca2+ overload, endoplasmic reticulum stress-associated JNK (c-Jun N-terminal kinase), and DNA damage-inducible transcript 3 (DDIT3). Our findings demonstrate that GdVO4:Eu3+ and LaVO4:Eu3+ nanoparticles aggravate the oxidative stress-induced damage to L929 cells, indicating that they might potentially be applied as anti-cancer agents.

In vitro and in vivo studies of the therapeutic potential of Tinospora crispa extracts in osteoarthritis: Targeting oxidation, inflammation, and chondroprotection

ETHNOPHARMACOLOGICAL RELEVANCE

The increasing incidence of osteoarthritis (OA), especially among the elderly population, highlights the need for more efficacious treatments that go beyond mere symptomatic relief. Tinospora crispa (L.) Hook. f. & Thomson (TC) boasts a rich traditional heritage, widespread use in Ayurveda, traditional Chinese medicine (TCM), and diverse indigenous healing practices throughout Southeast Asia for treating arthritis, rheumatism, fever, and inflammation.

AIM OF THE STUDY

This study investigates the anti-inflammatory and chondroprotective potential of TC stem extracts, including ethanolic TC extract (ETCE) and aqueous TC extract (ATCE), in modulating OA pathogenesis through in vitro and in vivo approaches.

MATERIALS AND METHODS

The study utilized LC-MS/MS to identify key compounds in TC stem extracts. In vitro experiments assessed the antioxidative and anti-inflammatory properties of ETCE and ATCE in activated macrophages, while an in vivo monoiodoacetate (MIA)-induced OA rat model evaluated the efficacy of ETCE treatment. Key markers of oxidative stress, such as superoxide dismutase (SOD) and catalase (CAT), were assessed alongside pro-inflammatory cytokines TNF-α and IL-1β, and matrix-degrading enzymes, matrix metalloproteinase (MMP 13 and MMP 3), to evaluate the therapeutic effects of TC stem extracts on OA.

RESULTS

Chemical profiling of the extracts was conducted using LC-MS/MS in positive ionization, identifying seven compounds, including pseudolaric acid B, stylopine, and reticuline, which were reported for the first time in this species. The study utilized varying concentrations of TC stem extracts, specifically 6.25-25 μg/mL for in vitro assays and 500 mg/kg for in vivo studies. Our findings also revealed that both ETCE and ATCE exhibit dose-dependent reduction in reactive oxygen species (41%-52%) and nitric oxide (NO) levels (50% and 72%), with ETCE displaying superior antioxidative efficacy and marked anti-inflammatory properties, significantly reducing TNF-α and IL-6 at concentrations above 12.5 μg/mL. In the MIA-induced OA rat model, ETCE treatment notably outperformed ATCE, markedly lowering TNF-α (1.91 ± 0.37 pg/mL) and IL-1β (26.30 ± 3.68 pg/mL) levels and effectively inhibiting MMP 13 and MMP 3 enzymes. Furthermore, macroscopic and histopathological assessments, including ICRS scoring and OARSI grading, indicate that TC stem extracts reduce articular damage and proteoglycan loss in rat knee cartilage. These results suggest that TC stem extracts may play a role in preventing cartilage degradation and potentially alleviating inflammation and pain associated with OA, though further studies are needed to confirm these effects.

CONCLUSION

This study highlights the potential of TC stem extracts as a novel, chondroprotective therapeutic avenue for OA management. By targeting oxidative stress, pro-inflammatory cytokines, and cartilage-degrading enzymes, TC stem extracts promise to prevent cartilage degradation and alleviate inflammation and pain associated with OA.

Examining transfer of TERT to mitochondria under oxidative stress

The primary role of telomerase is the lengthening of telomeres. Nonetheless, emerging evidence highlights additional functions of telomerase outside of the nucleus. Specifically, its catalytic subunit, TERT (Telomerase Reverse Transcriptase), is detected in the cytosol and mitochondria. Several studies have suggested an elevation in TERT concentration within mitochondria in response to oxidative stress. However, the origin of this mitochondrial TERT, whether transported from the nucleus or synthesized de novo, remains uncertain. In this study, we investigate the redistribution of TERT, labeled with a SNAP-tag, in response to oxidative stress using laser scanning fluorescence microscopy. Our findings reveal that, under our experimental conditions, there is no discernible transport of TERT from the nucleus to the mitochondria due to oxidative stress.

Proteomics fingerprinting reveals importance of iron and oxidative stress in Streptomyces scabies-Solanum tuberosum interactions

Introduction

The Gram-positive actinobacterium Streptomyces scabies is the major causal agent of potato common scab. The main pathogenicity factor is thaxtomin A, a phytotoxin that causes atypical cell death, although other secondary metabolites have been described to play a role in S. scabies virulence. Despite this, many aspects of the interaction between S. scabies and its primary host Solanum tuberosum L. remain to be elucidated.

Methods

Intracellular proteins of S. scabies EF-35 grown in the presence of in vitro produced tubers (microtubers) of the Russet Burbank and Yukon Gold potato cultivars were extracted and analysed by electrospray mass spectrometry (ES MS/MS). Based on the results of proteomic analysis, iron quantification by ICP-MS and nitrite quantification using Griess reagent in growth media as well as RT-qPCR analysis of the siderophore pyochelin gene expression were performed in the presence and absence of microtubers. Hydrogen peroxide accumulation was also determined in the nutrient medium used for co-cultivation of bacteria and potato microtubers.

Results

Potato microtubers caused an increase in the content of bacterial proteins involved in stress and defense, secondary metabolism, and cell differentiation, as well as secreted proteins. Co-cultivation with potato microtubers induced the accumulation of S. scabies proteins implicated in siderophore pyochelin biosynthesis, nitrite production and oxidative stress perception and response. The increase in the abundance of proteins related to pyochelin biosynthesis was consistent with a significant decrease in the iron content in the culture medium, as well as with induction of expression of pyochelin biosynthesis genes. Elevated nitrite/sulfite reductase protein levels were associated with increased nitrite excretion by S. scabies cells in the presence of host microtubers. The increase in the levels of proteins associated with signaling and oxidative stress response could have been caused by the accumulation of ROS, in particular hydrogen peroxide, detected in the studied system.

Discussion

These findings show that interactions of S. scabies with living potato microtubers induce the production of secondary metabolites, defense responses, and protection from oxidative stress. This study suggests the importance of iron during host - S. scabies interactions, resulting in competition between pathogen and its host.

Genetic variations in the antioxidant genes and their role in modulating susceptibility towards chronic obstructive pulmonary disease in the North Indian population

BACKGROUND

Chronic Obstructive Pulmonary Disease (COPD) is a persistent inflammatory lung condition characterized by an obstruction in removing oxygen from the lungs. Oxidant and antioxidant imbalance have long been hallmarks of COPD development, where the amount of antioxidants produced is less than that of oxidants. Here, polymorphism in the antioxidant enzymes like Catalase, Superoxide dismutase and Glutathione peroxidase plays an essential role in regulating the levels of oxidants.

METHODS

1000 subjects, including 500 COPD cases and 500 controls, have been recruited and genotyped to assess the correlation between COPD and the particular SNPS of antioxidant genes. Logistic regression was used to compute odds ratios (ORs) and 95 % confidence intervals (CIs) to assess the association between SNPs and COPD risk. The relationship between spirometry value and COPD for all SNPs has been analyzed using Kruskal Wallis's. Haplotype analysis has also been performed. The effect of SNP interactions on COPD risk was assessed through the Multifactor Dimensionality Reduction (MDR) approach, a nonparametric test for overcoming some of the limitations of the logistic regression for detecting and characterizing SNP interactions.

RESULTS

Our findings indicated a strong association between COPD and the variations in the CAT rs7943316 (OR = 0.61, Pc = 0.0001), SOD2 rs4880 (OR = 2.07, Pc = 0.0006), and GPx rs1050450 (OR = 0.60, Pc = 0.0018). Furthermore, SOD2 rs4880 was associated with forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) of COPD patients. Our study found that the triple combination of SOD1 (rs2234694), SOD1 (rs36232792) and SOD2 (rs4880) was found to be elevating the risk of COPD (OR = 2.83, Pc = 0.006). SOD2 rs4880 and GPx rs1050450 are also linked to cough and mucus production. The Haplotype study reveals a substantial relationship between CAT (rs7943316 and rs1001179) and SOD (rs2234694 and rs4880), which increases the risk of COPD. The three-locus model (CAT rs794331, CAT rs1101179, and GPx rs1050450) was the most effective for COPD risk assessment based on the MDR findings, which were statistically significant (p < 0.0001).

CONCLUSION

This study shows that rs7943316, rs4880, and rs1050450 are associated with the risk of COPD in the north Indian population and have the potential to enhance our knowledge of COPD at the molecular level, which in turn might pave the way for earlier detection, treatment, and preventive efforts.

Methodological Approaches to Experimental Evaluation of Neuroprotective Action of Potential Drugs

The authors propose a novel approach to a comprehensive evaluation of neuroprotective effects using both in vitro and in vivo methods. This approach allows for the initial screening of numerous newly synthesized chemical compounds and substances from plant and animal sources while saving animal life by reducing the number of animals used in research. In vitro techniques, including mitochondrial suspensions and neuronal cell cultures, enable the assessment of neuroprotective activity, which can be challenging in intact organisms. The preliminary methods help outline the neuroprotection mechanism depending on the neurodestruction agent. The authors have validated a model of acute cerebrovascular accident, which simulates key cerebrovascular phenomena such as reduced cerebral blood flow, energy deficit, glutamate-calcium excitotoxicity, oxidative stress, and early gene expression. A significant advantage of this model is its ability to reproduce the clinical picture of cerebral ischemia: impaired motor activity; signs of neurological deficits (paresis, paralysis, etc.); as well as disturbances in attention, learning, and memory. Crucial to this approach is the selection of biochemical, molecular, and cellular markers to evaluate nerve tissue damage and characterize potential neuroprotective agents. Additionally, a comprehensive set of molecular, biochemical, histological, and immunohistochemical methods is proposed for evaluating neuroprotective effects and underlying mechanisms of potential pharmaceutical compounds.

The ABA/LANCL1-2 Hormone/Receptors System Controls ROS Production in Cardiomyocytes through ERRα

Rat H9c2 cardiomyocytes overexpressing the abscisic acid (ABA) hormone receptors LANCL1 and LANCL2 have an increased mitochondrial proton gradient, respiration, and vitality after hypoxia/reoxygenation. Our aim was to investigate the role of the ABA/LANCL1-2 system in ROS turnover in H9c2 cells. H9c2 cells were retrovirally infected to induce the overexpression or silencing of LANCL1 and LANCL2, without or with the concomitant silencing of the transcription factor ERRα. Enzymes involved in radical production or scavenging were studied by qRT-PCR and Western blot. The mitochondrial proton gradient and ROS were measured with specific fluorescent probes. ROS-generating enzymes decreased, ROS-scavenging enzymes increased, and mitochondrial ROS were reduced in LANCL1/2-overexpressing vs. control cells infected with the empty vector, while the opposite occurred in LANCL1/2-silenced cells. The knockdown of ERRα abrogated all beneficial effects on ROS turnover in LANCL1/2 overexpressing cells. Taken together, these results indicate that the ABA/LANCL1-2 system controls ROS turnover in H9c2 via ERRα. The ABA/LANCL system emerges as a promising target to improve cardiomyocyte mitochondrial function and resilience to oxidative stress.

Photothermal Excitation of Neurons Using MXene: Cellular Stress and Phototoxicity Evaluation

Understanding the communication of individual neurons necessitates precise control of neural activity. Photothermal modulation is a remote and non-genetic technique to control neural activity with high spatiotemporal resolution. The local heat release by photothermally active nanomaterial will change the membrane properties of the interfaced neurons during light illumination. Recently, it is demonstrated that the two-dimensional Ti3C2Tx MXene is an outstanding candidate to photothermally excite neurons with low incident energy. However, the safety of using Ti3C2Tx for neural modulation is unknown. Here, the biosafety of Ti3C2Tx-based photothermal modulation is thoroughly investigated, including assessments of plasma membrane integrity, mitochondrial stress, and oxidative stress. It is demonstrated that culturing neurons on 25 µg cm-2 Ti3C2Tx films and illuminating them with laser pulses (635 nm) with different incident energies (2-10 µJ per pulse) and different pulse frequencies (1 pulse, 1 Hz, and 10 Hz) neither damage the cell membrane, induce cellular stress, nor generate oxidative stress. The threshold energy to cause damage (i.e., 14 µJ per pulse) exceeded the incident energy for neural excitation (<10 µJ per pulse). This multi-assay safety evaluation provides crucial insights for guiding the establishment of light conditions and protocols in the clinical translation of photothermal modulation.

An effective algaecide for the targeted destruction of Karenia brevis

We address the targeted destruction of Karenia brevis using the algaecide calcium peroxide, in tandem with the flocculation and sinking of the species. The specific aspect of the approach is the incorporation of the algaecide within the floc to rapidly kill K. brevis, thus minimizing escape of cells from the floc and reentry to the water column. CaO₂ gradually produces H₂O₂, which diffuses through cell membranes and induces oxidative stress, leading to cell death via excessive reactive oxygen species (ROS) formation. The effect of varying doses of calcium peroxide on K. brevis cells was measured with pulse amplitude modulated fluorometry and indicated that doses as low as 30 mg/L when integrated into flocs are effective in suppressing photosynthesis. Cell viability assays also indicate that such low levels are sufficient to cause cell death in a 3-6 hour time period. Thus, the proposed technology involving the incorporation of calcium peroxide in a cationic flocculating agent (polyaluminum chloride, PAC) leads to an inexpensive and scalable technology to mitigate harmful algal blooms of K. brevis.

Mechanistic elucidation of QiJu-DiHuang Wan in management of age-related dry eye through metabolomics and network pharmacology

BACKGROUND

QiJu-DiHuang Wan (QJDHW), a frequently employed Chinese herbal formula, is used to treat blurred vision. Even so, it is unclear how it works in treating age-related dry eyes.

OBJECTIVE

The aim of this research is to explore the potential mechanisms of QJDHW in treating dry eye using UHPLC-QE-MS, metabolomics, and network pharmacology.

METHODS

Six male SD rats were segregated into control and QJDHW groups. Following intervention, The primary active ingredients in QJDHW-containing serum were identified using UHPLC-QE-MS. Metabolomics and network pharmacology were utilized to investigate potential targets and pathways involved following QJDHW use. Primary lacrimal epithelial cells were used for validation.

RESULTS

A total of 425 active ingredients of QJDHW were identified, along with 210 active ingredients in QJDHW-containing serum. A comparison of QJDHW-containing serum and control serum samples revealed 40 metabolic differentiators. A total of 24 metabolites were found in QJDHW and QJDHW-containing serum. Network pharmacology identified 3,144 targets for dry eye disease, and 102 metabolite action targets were found for QJDHW-entering components. KEGG Enrichment Analysis revealed significance of HIF-1, apoptosis, cell cycle and PI3K-Akt, among others. HIF-1 and PI3K-Akt were chosen for verification in the oxidative damage model of lacrimal epithelial cells.

CONCLUSION

The main active ingredients of QJDHW and its containing serum were elucidated by UHPLC-QE-MS demonstrating that QJDHW treats age-associated dry eye by inhibiting HIF1α/NF-κB through ROS inhibition and PI3K/p-AKT activation.

Redox Status as a Key Driver of Healthy Pancreatic Beta-Cells

Redox status plays a multifaceted role in the intricate physiology and pathology of pancreatic beta-cells, the pivotal regulators of glucose homeostasis through insulin secretion. They are highly responsive to changes in metabolic cues where reactive oxygen species are part of it, all arising from nutritional intake. These molecules not only serve as crucial signaling intermediates for insulin secretion but also participate in the nuanced heterogeneity observed within the beta-cell population. A central aspect of beta-cell redox biology revolves around the localized production of hydrogen peroxide and the activity of NADPH oxidases which are tightly regulated and serve diverse physiological functions. Pancreatic beta-cells possess a remarkable array of antioxidant defense mechanisms although considered relatively modest compared to other cell types, are efficient in preserving redox balance within the cellular milieu. This intrinsic antioxidant machinery operates in concert with redox-sensitive signaling pathways, forming an elaborate redox relay system essential for beta-cell function and adaptation to changing metabolic demands. Perturbations in redox homeostasis can lead to oxidative stress exacerbating insulin secretion defect being a hallmark of type 2 diabetes. Understanding the interplay between redox signaling, oxidative stress, and beta-cell dysfunction is paramount for developing effective therapeutic strategies aimed at preserving beta-cell health and function in individuals with type 2 diabetes. Thus, unraveling the intricate complexities of beta-cell redox biology presents exciting avenues for advancing our understanding and treatment of metabolic disorders.

Neuropeptide alpha-Melanocyte stimulating hormone preserves corneal endothelial morphology in a murine model of Fuchs dystrophy

Fuchs endothelial corneal dystrophy is a heterogenous disease with multifactorial etiology, and genetic, epigenetic, and exogenous factors contributing to its pathogenesis. DNA damage plays a significant role, with ultraviolet-A (UV-A) emerging as a key contributing factor. We investigate the potential application of neuropeptide α-melanocyte stimulating hormone (α-MSH) in mitigating oxidative stress induced endothelial damage. First, we examined the effects of α-MSH on a cultured human corneal endothelial cell line (HCEnC-21T) exposed to hydrogen peroxide (H2O2) induced oxidative DNA damage. We performed immunofluorescence and flow cytometry to assess DNA damage and cell death in the cultured cells. Additionally, we used an established mouse model that utilizes ultraviolet light to induce corneal endothelial cell damage resulting in decreased CEnC number, increased cell size variability, and decreased percentage of hexagonal cells. This endothelial decompensation leads to an increase in corneal thickness. Following UV-A exposure, the mice were systemically treated with α-MSH, either immediately after exposure (early treatment) or beginning two weeks post-exposure (delayed treatment). To evaluate treatment efficacy, we analyzed CEnC density and morphology using in vivo confocal microscopy, and central corneal thickness using anterior segment optical coherence tomography. Our findings demonstrated that α-MSH treatment effectively protects HCEnC-21T from free-radical induced oxidative DNA damage and subsequent cell death. In vivo, α-MSH treatment, mitigated the loss of CEnC density, deterioration of cell morphology and suppression of the resultant corneal swelling. These results underline the potential application of α-MSH as a therapeutic agent for mitigating corneal endothelial damage.