The thioredoxin antioxidant system

Structural simplification of quaternary benzophenanthridine alkaloids generating a candidate for the treatment of non-small cell lung cancer

Quaternary benzophenanthridine alkaloids (QBAs), such as sanguinarine, chelerythrine, and nitidine, possess diverse pharmacological activities. This study presents a simplified structure for QBAs, yielding twelve three-membered phenanthridine alkaloids. Notably, compound 6f demonstrates enhanced potency in selectively inhibiting thioredoxin reductase (TrxR, TXNRD) and exhibits significant cytotoxicity against non-small cell lung cancer (NSCLC) cells. While TrxR is a selenoenzyme, many of its inhibitors react with biological thiols; however, 6f shows minimal reactivity with thiols such as glutathione (GSH) and cysteine. Mechanistic investigations reveal that 6f stimulates reactive oxygen species production, reduces intracellular thiols, and decreases the GSH/GSSG ratio, leading to cell apoptosis through oxidative stress. Moreover, significant tumor regression has been observed in nude mice with NSCLC following treatment with 6f. The pronounced anticancer activity and possible mechanism of action of 6f suggest its potential as a candidate for further development in NSCLC therapy.

Sensitizing ferroptotic and apoptotic cancer therapy via tailored micelles-mediated coenzyme and ATP depletion under hypoxia

Concurrent induction of apoptosis and ferroptosis is promising in handling heterogenous cancers. We report a tailored polymeric micellar nanoplatform for the combinational anti-tumor therapy. Two stimuli-responsive amphiphlic block copolymers were synthesized, bearing three functional moieties, i.e. azobenzene, nitroimidazole and 3-fluorophenylboronic acid. Azobenzene could enhance the cellular uptake of micelles. Nitroimidazole and 3-fluorophenylboronic acid could deplete the reduced nicotinamide adenine dinucleotide phosphate (NADPH), glucose and adenosine triphosphate (ATP) under hypoxia, sensitizing ferroptotic and apoptotic cell death. The proof-of-concept was demonstrated in a triple-negative breast cancer cell line (MDA-MB-231). Irrespective of the free or encapsulated form, doxorubicin and auranofin showed a synergistic action, evidenced by a low combination index (< 1). The co-delivery micelles showed improved potency than the single drug-loaded micelles in terms of the biomarkers of apoptosis (e.g. caspase 3/9, cytochrome c and ATP) and ferroptosis (e.g. thioredoxin reductase, thioredoxin, glutathione, NADPH, malondialdehyde and lipid peroxides). The apoptosis and ferroptosis induction ability of cargo-free micelles was proved. The in vivo efficacy was verified in the MDA-MB 231 tumor-bearing nude mice model. The current work offers a promising strategy of combinational anti-tumor drug delivery for potent induction of ferroptosis and apoptosis via the sensitization effect of vehicle in the hypoxic tumor.

The antioxidant protein PntA coordinates with OmpW to resist oxidant stress in Actinobacillus pleuropneumoniae

Bacteria have evolved various strategies to combat oxidative stress caused by reactive oxygen species (ROS). Outer membrane proteins including OmpW play multiple roles in bacterial physiology, stress responses and virulence. In this study, the OmpW protein of Actinobacillus pleuropneumoniae, an important porcine respiratory tract pathogen, was found to contribute to virulence but concurrently to reduce resistance to oxidative stress. An ompW deletion (ΔompW) showed attenuation in mice, and decreased adherence to pig tracheal epithelial cells and resistance to hyperosmotic stress, compared to the wild-type (WT) strain. However, the ΔompW strain exhibited increased resistance to H2O2, enhanced survival ability within macrophages, and lower intracellular ROS level. OmpW may serve as a H2O2 channel. Further study showed that exposure to H2O2 significantly suppressed ompW transcription in the WT strain. Overexpression of these two proteins in WT and ΔompW increased the antioxidative properties of the bacteria. Furthermore, by construction of the double gene mutant ΔompWΔpntA, it was found that PntA could reverse the effects of OmpW on the bacterial survivability and intracellular ROS level after H2O2 treatment. Therefore, by interacting with OmpW, PntA alleviated the increased oxidative stress sensitivity caused by OmpW. These results suggest a mechanism whereby antioxidant proteins collaborate with OMPs to protect bacteria from oxidative stress.

Participation of a cysteine tetrad in the recycling mechanism of methionine sulfoxide reductase A from radiation-tolerant Deinococcus bacteria

Methionine oxidation leads to the formation of methionine sulfoxide (MetO), which is reduced back to Met by methionine sulfoxide reductases (Msrs). The catalytic mechanism used by A-type Msr (MsrA) for MetO reduction requires a catalytic cysteine (Cys), which is converted to a sulfenic acid. In general, two resolving Cys are required for the regeneration of the catalytic Cys forming two consecutive disulfide bridges, the last one being efficiently reduced by thioredoxin (Trx). Here, we performed the biochemical characterization of MsrA from Deinococcus deserti. It possesses four Cys, two present in the active site motif (18 and 21) and two distal ones (53 and 163). We produced MsrA variants mutated for these cysteines and analyzed their capacity to reduce MetO in the presence of the NADPH-Trx reductase/Trx system, their ability to form heterodimers with Trxs, and their redox status after incubation with MetO. We show that all four Cys are involved in the regeneration process of enzyme activity by Trx. After MetO reduction by Cys18, a first disulfide bridge is formed with Cys21. A second disulfide involving Cys21 with either Cys53 or Cys163 is reduced by Trx, and a third Cys53-Cys163 disulfide can be formed and also reduced by Trx. These findings highlighting for the first time the involvement of a Cys tetrad in the catalytic and regeneration mechanisms for a MsrA are placed in a structural context by performing 3D modelling and discussed in relation to the known recycling mechanisms involving a Cys triad.

The involvement of thioredoxin reductase genes in development, reproduction and deltamethrin tolerance in the red flour beetle, Tribolium castaneum

As an essential component of the thioredoxin system, thioredoxin reductase (TrxR) plays an important role in maintaining redox homeostasis in mammalian cells, however, functional characterization of insect TrxRs is still limited. In this study, full-length cDNAs of TcTrxR1 and TcTrxR2 were cloned from the red flour beetle, Tribolium castaneum. Sequence analysis revealed the highly conserved active site motifs CVNVGC and CCS at the N-terminal and C-terminal of TcTrxR1, respectively, whereas TcTrxR2 lacks these two conserved motifs. Analysis of the spatio-temporal expression pattern by RT-qPCR showed that the expression of TcTrxR1 was the highest in 1-day-old larva and brain, and TcTrxR2 was highly expressed in eggs and fat body, respectively. Further functional analysis by RNA interference (RNAi) revealed that knockdown of TcTrxR1 and TcTrxR2 at the larval stage led to 100 % and 98.67 % mortality of larvae beetles, and pupal RNAi of TcTrxR1 and TcTrxR2 resulted in decreased eclosion rates as well as failure of the female adults to lay eggs. Additionally, injection of dsTcTrxR2 decreased the tolerance of beetles to deltamethrin, whereas knockdown of TcTrxR1 significantly increased the tolerance of beetles to deltamethrin. Notably, knockdown of TcTrxR1 significantly upregulated the expression of TcCYP6BQ2, TcCYP6BQ4 and TcCYP6BQ7, and led to nuclear translocation of transcription factor CncC, a major regulator of detoxification in insects. These findings provide insights into the function of insect TrxRs as well as the regulatory mechanisms of CncC, and have applied implications for the RNAi-based insect pest control.

S-nitrosylation and S-glutathionylation: Lying at the forefront of redox dichotomy or a visible synergism?

The discovery of novel oxidoreductases and their specific functional revelations as cellular disulfide reductants, S-denitrosylases, or S-deglutathionylases, alongside the well-established major redoxins/antioxidant systems comprising thioredoxin and glutaredoxin, enlarges the spectrum of redox players in the intracellular milieu as well as pushes us to stand at the crossroads concerning the choice of antioxidants that can serve the benefit of catalyzing their cognate protein/non-protein substrates with better efficiencies than the rest. The complexity is extended to exploring the redundancy amongst the redoxin systems and identifying their overlapping or unique substrate preferences to intervene with oxidative or nitrosative stress-induced reversible protein posttranslational modifications such as S-nitrosylation and S-glutathionylation. Contrary to popular expectations of reiterating the theoretical and evidence-based existence of these modifications, the current review aims to take the first leap in delineating the logical reasons behind the competing susceptibility of reactive cysteine thiols toward either or both redox modifications and their subsequent extent of stability in the presence of cellular reductants (thioredoxin, glutaredoxin, thioredoxin-like mimetic or lipoic acid, dihydrolipoic acid, and glutathione), thus rebuilding the underpinnings of a 'redox-interactome' that can further pave the way for the global mapping of ideal substrates exhibiting stringencies or synergism in the context of translational redox research.

Metal-Based Approaches for the Fight against Antimicrobial Resistance: Mechanisms, Opportunities, and Challenges

The rapid emergency and spread of antimicrobial-resistant (AMR) bacteria and the lack of new antibiotics being developed pose serious threats to the global healthcare system. Therefore, the development of more effective therapies to overcome AMR is highly desirable. Metal ions have a long history of serving as antimicrobial agents, and metal-based compounds are now attracting more interest from scientific communities in the fight against AMR owing to their unique mechanism. Moreover, they may also serve as antibiotic adjuvants to enhance the efficacy of clinically used antibiotics. In this perspective, we highlight important showcase studies in the last 10 years on the development of metal-based strategies to overcome the AMR crisis. Specifically, we categorize these metallo-antimicrobials into five classes based on their modes of action (i.e., metallo-enzymes and metal-binding enzyme inhibitors, membrane perturbants, uptake/efflux system inhibitors/regulators, persisters inhibitors, and oxidative stress inducers). The significant advantages of metallo-antimicrobials over traditional antibiotics lie in their multitargeted mechanisms, which render less likelihood to generate resistance. However, we notice that such modes of action of metallo-antimicrobials may also raise concern over their potential side effects owing to the low selectivity toward pathogens and host, which appears to be the biggest obstacle for downstream translational research. We anticipate that combination therapy through repurposing (metallo)drugs with antibiotics and the optimization of their absorption route through formulation to achieve a target-oriented delivery will be a powerful way to combat AMR. Despite significant challenges, metallo-antimicrobials hold great opportunities for the therapeutic intervention of infection by resistant bacteria.

Ferulic Acid Ameliorates Chromium-Induced Nephrotoxicity: Modulation of PERK/eIF2α/ATF4/CHOP, Nrf2, and Inflammatory Signaling

Hexavalent chromium (HVC) is a highly toxic heavy metal that induces organ damage especially to the kidney. It induces tubular damage and glomerular dysfunction basically through triggering inflammation, redox imbalance, and apoptotic cell death. The current study aimed at investigating the possible protective ability of ferulic acid (FA) against HVC-induced nephrotoxicity employing male Wistar rats as an experimental model. The results revealed the ability of FA to suppress the HVC-evoked renal tissue injury and to improve the renal function, as evidenced by enhanced histopathological picture, reduced levels of the tubular injury biomarker KIM- 1, and the glomerular dysfunction biomarkers serum cystatin C and urea, along with boosted glomerular filtration rate. At the molecular level, FA suppressed HVC-induced inflammation, as indicated by decreased nuclear NF-κB p65 protein abundance and phosphorylation, and reduced cyclooxygenase- 2, IL- 1β, and TNF-α levels. FA significantly alleviated the HVC-induced redox imbalance as demonstrated by reduced lipids and DNA oxidation, upregulation of Nrf2 signaling, improved activity of the antioxidant enzymes thioredoxin reductase, catalase, and glutathione peroxidase, along with significant elevation of the reduced glutathione level. FA inhibited apoptosis in the HVC-intoxicated rats as evidenced by reduced activity of the apoptotic marker caspase- 3 and modulation of BAX and Bcl2 proteins. Interestingly, FA suppressed the unfolded protein response signaling molecules including PERK, eIF2α, ATF4, and CHOP, which play essential roles in induction of apoptosis and inflammation. Together, these results underscore the nephroprotective impact of FA against HVC-evoked nephrotoxicity and highlight PERK, eIF2α, ATF4, CHOP, Nrf2, and NF-κB as potential molecular targets.

Mechanism of glutathionylation of the active site thiols of peroxiredoxin 2

Peroxiredoxin 2 (Prdx2) undergoes ready glutathionylation, and glutaredoxin-catalyzed deglutathionylation provides an alternative mechanism to thioredoxin/thioredoxin reductase for recycling the reduced protein (Peskin et al JBC 216, 3053, 2016). To elucidate the mechanism of glutathionylation, we have carried out kinetic studies using stopped flow and SDS PAGE plus product analysis by mass spectrometry. Kinetic modelling shows a mechanism in which exchange of Prdx2 disulfide with physiological concentrations of GSH occurs over seconds to minutes, initially at one active site to produce glutathionylated dimers linked by one disulfide. Exchange with GSH yields glutathionylation at both the peroxidatic (CP) and resolving cysteines (CR), the former predominating. Rate constants of 1.5 M-1s-1 and 0.021 s-1 were determined for exchange-mediated glutathionylation and deglutathionylation. Similar exchange reactions subsequently occur at the second active site. The rate of reaction of the CP sulfenic acid of wildtype Prdx2 with GSH (k = 10 M-1s-1) is 8-30 fold slower than when CR is mutated to Ser, Trp or Asp and this reaction cannot effectively compete with intramolecular condensation. Consequently, when H2O2 reacts with reduced Prdx2 in the presence of GSH, the initial product is predominately the Prdx disulfide and glutathionylation subsequently occurs by exchange. However, glutathionylation of CR in the presence of H2O2 facilitates condensation of CP sulfenic acid with GSH to give diglutathionylated products and suppresses hyperoxidation. This displaces equilibria and accelerates the conversion of Prdx2 to monomeric species. These results have implications for understanding the mechanism of relays between Prdx2 and other thiol proteins.

How acetamiprid induced toxicity on freshwater mussel: Biomarker and histopathological responses?

This study examines the acute and chronic toxicity, immunological responses, oxidative stress, and histopathological effects of acetamiprid (ACE) on the freshwater mussel Unio terminalis. Laboratory experiments determined the 96-h LC50 value, classifying ACE as moderately toxic to this species. Chronic toxicity tests were conducted using two controls [freshwater and dimethyl sulfoxide (DMSO)] and two ACE concentrations (3.52 mg/L and 6.70 mg/L), with exposure durations of 48 h, 7 days, and 21 days under semi-static conditions. Sublethal effects were assessed by analyzing total hemocyte count (THC), total antioxidant status (TAS), and total oxidative stress (TOS) in hemolymph samples. ACE exposure significantly reduced THC, indicating immunosuppression that could impair physiological functions and immune defense. TAS values remained stable, suggesting robust antioxidant regulation, while prolonged exposure led to elevated TOS levels, indicating oxidative stress and potential cellular damage. Histopathological changes observed included lipofuscin accumulation, hemocytic infiltration, gill tissue degeneration, and tubular degeneration in digestive glands. These results highlight the vulnerability of U. terminalis to ACE exposure and its usefulness as a bioindicator species of aquatic ecosystem health. The study underscores the need for stricter pesticide regulation and further research into chronic exposure and combined chemical effects to protect aquatic biodiversity.

Sublethal damage and recovery of Staphylococcus aureus exposed to intense pulsed light: Implications for minimally processed foods

The growing demand for minimally processed foods has promoted the application of non-thermal sterilization technologies, such as intense pulsed light (IPL), to ensure food safety while preserving nutritional and sensory attributes. However, the potential for sublethal bacterial recovery after IPL treatment remains a major concern. In this study, IPL showed varying bactericidal capacities for Staphylococcus aureus in water and pork surfaces, respectively reducing by approximately 4 and 1.2 log CFU/mL after 2 applications at 4 cm, despite similar damage was observed by SEM. The differences in sterilization were speculated that sublethal S. aureus cells caused by IPL could be recovered within a nutritive environment such as pork. To elucidate the underlying mechanisms, intracellular redox enzyme activities and transcriptomic responses of sublethal S. aureus were analyzed. The results indicate that S. aureus repaired the damage caused by IPL mainly through three ways. Firstly, DNA damage was repaired by activating SOS response, restoring DNA double-strand breaks, and improving purine metabolism. Besides, S. aureus responded to oxidative damage by maintaining iron homeostasis, synthesizing biotin and clearing aldehyde metabolites. Meanwhile, amino acids, phosphate and ferric ions served as substrates and ATP for cell repair by amino acid metabolism. In conclusion, this study analyzed the recovery mechanism of sublethal S. aureus under IPL stimulus, and provides new insights for controlling pathogenic bacteria in minimally processed food industry.

Inhibition of thioredoxin reductase 1 sensitizes glucose-starved glioblastoma cells to disulfidptosis

Disulfidptosis is a recently identified form of cell death characterized by the aberrant accumulation of cellular disulfides. This process primarily occurs in glucose-starved cells expressing higher levels of SLC7A11 and has been proposed as a therapeutic strategy for cancers with hyperactive SCL7A11. However, the potential for inducing disulfidptosis through other mechanisms in cancers remains unclear. Here, we found that inhibiting thioredoxin reductase 1 (TrxR1), a key enzyme in the thioredoxin system, induces disulfidptosis in glioblastoma (GBM) cells. TrxR1 expression is elevated in GBM with activated transcriptional coactivator with PDZ-binding motif (TAZ) and correlates with poor prognosis. TrxR1 inhibitors induced GBM cell death that can be rescued by disulfide reducers but not by ROS scavengers or inhibitors of apoptosis, ferroptosis, or necroptosis. Glucose-starved cells, but not those deprived of oxygen or glutamine, increased TrxR1 expression in an NRF2-dependent manner and were more sensitive to TrxR1 inhibition-induced cell death. The dying cells initially exhibited highly dynamic lamellipodia, followed by actin cytoskeleton collapse. This process involved the accumulation of cytosolic peroxisomes and micropinocytic caveolae, as well as small gaps in the plasma membrane. Depletion of the WAVE complex component NCKAP1 partially rescued the cells, whereas Rac inhibition enhanced cell death. In an orthotopic xenograft GBM mouse model, TrxR1 depletion inhibited tumor growth and improved survival. Furthermore, cells undergoing TrxR1 inhibition exhibited features of immunogenic cell death. Therefore, this study suggests the potential of targeting TrxR1 as a therapeutic strategy in GBM.

Pharmacological Inhibition of TXNRD1 by a Small Molecule Flavonoid Butein Overcomes Cisplatin Resistance in Lung Cancer Cells

Mammalian cytosolic selenoprotein thioredoxin reductase (TXNRD1) is crucial for maintaining the reduced state of cellular thioredoxin 1 (TXN1) and is commonly up-regulated in cancer cells. TXNRD1 has been identified as an effective target in cancer chemotherapy. Discovering novel TXNRD1 inhibitors and elucidating the cellular effects of TXNRD1 inhibition are valuable for developing targeted therapies based on redox regulation strategies. In this study, we demonstrated that butein, a plant-derived small molecule flavonoid, is a novel TXNRD1 inhibitor. We found that butein irreversibly inhibited recombinant TXNRD1 activity in a time-dependent manner. Using TXNRD1 mutant variants and LC-MS, we identified that butein modifies the catalytic cysteine (Cys) residues of TXNRD1. In cellular contexts, butein promoted the accumulation of reactive oxygen species (ROS) and exhibited cytotoxic effects in HeLa cells. Notably, we found that pharmacological inhibition of TXNRD1 by butein overcame the cisplatin resistance of A549 cisplatin-resistant cells, accompanied by increased cellular ROS levels and enhanced expression of p53. Taken together, the results of this study demonstrate that butein is an effective small molecule inhibitor of TXNRD1, highlighting the therapeutic potential of inhibiting TXNRD1 in platinum-resistant cancer cells.

Suppression of the LKB1-AMPK-SLC7A11-GSH signaling pathway sensitizes NSCLC to albumin-bound paclitaxel via oxidative stress

Albumin-bound paclitaxel (nab-PTX) is an important chemotherapeutic drug used for the treatment of advanced and metastatic non-small cell lung cancer (NSCLC). One critical issue in its clinical application is the development of resistance; thus, a deeper understanding of the mechanisms underlying the primary resistance to nab-PTX is expected to help to develop effective therapeutic strategies to overcome resistance. In this study, we made an unexpected discovery that NSCLC with wild-type (WT) Liver kinase B1 (LKB1), an important tumor suppressor and upstream kinase of AMP-activated protein kinase (AMPK), is more resistant to nab-PTX than NSCLC with mutant LKB1. Mechanistically, LKB1 status does not alter the intracellular concentration of nab-PTX or affect its canonical pharmacological action in promoting microtubule polymerization. Instead, we found that LKB1 mediates AMPK activation, leading to increased expression of SLC7A11, a key amino acid transporter and intracellular level of glutathione (GSH), which then attenuates the production of reactive oxygen species (ROS) and apoptotic cell death induced by nab-PTX. On the other hand, genetic or pharmacological inhibition of AMPK in LKB1-WT NSCLC reduces the expression of SLC7A11 and intracellular GSH, increases ROS level, and eventually promotes the apoptotic cell death induced by nab-PTX in vitro. Consistently, the combination of nab-PTX with an AMPK inhibitor exhibits a greater therapeutic efficacy in LKB1-WT NSCLC using xenograft models in vivo. Taken together, our data reveal a novel role of LKB1-AMPK-SLC7A11-GSH signaling pathway in the primary resistance to nab-PTX, and provide a therapeutic strategy for the treatment of LKB1-WT NSCLC by targeting the LKB1-AMPK-SLC7A11-GSH pathway.

A new gold(I) phosphine complex induces apoptosis in prostate cancer cells by increasing reactive oxygen species

Thioredoxin reductase (TrxR) is a pivotal regulator of redox homeostasis. It is frequently overexpressed in various cancer cells, including prostate cancer, making it a promising target for the development of anti-cancer drugs. In this study, we screened a series of newly designed complexes of gold(I) phosphine. Specifically, Compound 5 exhibited the highest cytotoxicity against prostate cancer cells and demonstrated stronger antitumor effects than commonly used drugs, such as cisplatin and auranofin. Importantly, our mechanistic study revealed that Compound 5 effectively inhibits the TrxR system in vitro. Additionally, Compound 5 promoted intracellular accumulation of reactive oxygen species (ROS), leading to mitochondrial dysfunction and irreversible apoptosis in prostate cancer cells. Our in vivo xenograft study further demonstrated that Compound 5 has excellent antitumor activity against prostate cancer cells, but does not cause severe side effects. These findings provide a promising lead Compound for the development of novel antitumor agents targeting prostate cancer and offer a valuable tool for investigating biological pathways involving TrxR and ROS modulation.

Metabolic and Mitochondrial Dysregulations in Diabetic Cardiac Complications

The growing prevalence of diabetes highlights the urgent need to study diabetic cardiovascular complications, specifically diabetic cardiomyopathy, which is a diabetes-induced myocardial dysfunction independent of hypertension or coronary artery disease. This review examines the role of mitochondrial dysfunction in promoting diabetic cardiac dysfunction and highlights metabolic mechanisms such as hyperglycaemia-induced oxidative stress. Chronic hyperglycaemia and insulin resistance can activate harmful pathways, including advanced glycation end-products (AGEs), protein kinase C (PKC) and hexosamine signalling, uncontrolled reactive oxygen species (ROS) production and mishandling of Ca2+ transient. These processes lead to cardiomyocyte apoptosis, fibrosis and contractile dysfunction. Moreover, endoplasmic reticulum (ER) stress and dysregulated RNA-binding proteins (RBPs) and extracellular vesicles (EVs) contribute to tissue damage, which drives cardiac function towards heart failure (HF). Advanced patient-derived induced pluripotent stem cell (iPSC) cardiac organoids (iPS-COs) are transformative tools for modelling diabetic cardiomyopathy and capturing human disease's genetic, epigenetic and metabolic hallmarks. iPS-COs may facilitate the precise examination of molecular pathways and therapeutic interventions. Future research directions encourage the integration of advanced models with mechanistic techniques to promote novel therapeutic strategies.

SCFA biotherapy delays diabetes in humanized gnotobiotic mice by remodeling mucosal homeostasis and metabolome

Type 1 diabetes (T1D) is linked to an altered gut microbiota characterized by reduced short-chain fatty acid (SCFA) production. Oral delivery of a SCFA-yielding biotherapy in adults with T1D was followed by increased SCFAs, altered gut microbiota and immunoregulation, as well as delaying diabetes in preclinical models. Here, we show that SCFA-biotherapy in humans is accompanied by remodeling of the gut proteome and mucosal immune homeostasis. Metabolomics showed arginine, glutamate, nucleotide and tryptophan metabolism were enriched following the SCFA-biotherapy, and found metabolites that correlated with glycemic control. Fecal microbiota transfer demonstrated that the microbiota of SCFA-responders delayed diabetes progression in humanized gnotobiotic mice. The protected mice increased similar metabolite pathways to the humans including producing aryl-hydrocarbon receptor ligands and reducing inflammatory mucosal immunity and increasing IgA production in the gut. These data demonstrate that a potent SCFA immunomodulator promotes multiple beneficial pathways and supports targeting the microbiota as an approach against T1D. Trial registration: Australia New Zealand Clinical Trials Registry ACTRN12618001391268.

Two redox-responsive LysR-type transcription factors control the oxidative stress response of Agrobacterium tumefaciens

Pathogenic bacteria often encounter fluctuating reactive oxygen species (ROS) levels, particularly during host infection, necessitating robust redox-sensing mechanisms for survival. The LysR-type transcriptional regulator (LTTR) OxyR is a widely conserved bacterial thiol-based redox sensor. However, members of the Rhizobiales also encode LsrB, a second LTTR with potential redox-sensing function. This study explores the roles of OxyR and LsrB in the plant-pathogen Agrobacterium tumefaciens. Through single and combined deletions, we observed increased H2O2 sensitivity, underscoring their function in oxidative defense. Genome-wide transcriptome profiling under H2O2 exposure revealed that OxyR and LsrB co-regulate key antioxidant genes, including katG, encoding a bifunctional catalase/peroxidase. Agrobacterium tumefaciens LsrB possesses four cysteine residues potentially involved in redox sensing. To elucidate the structural basis for redox-sensing, we applied single-particle cryo-EM (cryogenic electron microscopy) to experimentally confirm an AlphaFold model of LsrB, identifying two proximal cysteine pairs. In vitro thiol-trapping coupled with mass spectrometry confirmed reversible thiol modifications of all four residues, suggesting a functional role in redox regulation. Collectively, these findings reveal that A. tumefaciens employs two cysteine-based redox sensing transcription factors, OxyR and LsrB, to withstand oxidative stress encountered in host and soil environments.

Topical Instillation of N-Acetylcysteine and N-Acetylcysteine Amide Impedes Age-Related Lens Opacity in Mice

Cataracts, the leading cause of blindness globally, are caused by oxidative stress and inflammation, which disrupt lens transparency due to increased accumulation of reactive oxygen species (ROS) as well as protein and DNA damage during aging. Using in vitro, ex vivo, and in vivo models, we determined the protective efficacy of N-acetylcysteine amide (NACA) against oxidative stress-induced and aging-induced cataractogenesis. We found that lens epithelial cells exposed to the oxidative stress inducers hydrogen peroxide (H2O2) or tert-butyl hydroperoxide showed significant ROS accumulation and reduced cellular viability. These effects were inhibited by NACA via the suppression of ROS and thioredoxin-interacting protein (Txnip) expression, a regulator of oxidative stress-related cellular damage and inflammation. In ex vivo lens experiments, NACA significantly reduced H2O2-induced lens opacity and preserved lens integrity. Similarly to NACA-treated lenses ex vivo, the integrity and opacity of aged mouse lenses, when topically instilled with NACA, were preserved and reduced, respectively, and are directly related to reduced Txnip and increased thioredoxin (Trx) expression levels. Overall, our findings demonstrated the protective ability of NACA to abate aberrant redox-active pathways, particularly the ROS/TRX/TXNIP axis, thereby preventing cataractogenesis and preserving eye lens integrity and ultimately impeding aging-related cataracts.

A comprehensive survey of cytotoxic active half-sandwich Ir(III) complexes: structural perspective, and mechanism of action

Iridium(III) complexes, particularly those with piano-stool structures, have drawn a lot of interest recently as possible anticancer drugs. These complexes, which have displayed enhanced cytotoxicity and cytoselectivity compared with clinically approved drugs like cisplatin, oxaliplatin, and carboplatin, hold promising prospects for further anticancer research. Our review aims to explore the complex interplay between cytotoxic properties, cellular uptake efficiency, and intracellular distribution properties of this class of Ir(III) complexes, considering the variation of the coordination site atoms. We provide an overview of the majority of research on mono- and polynunclear half-sandwich Ir(III) complexes with mono- and bidentate ligands, focusing on the impact of altering the leaving group, tethers, substituents on the cyclopentadienyl ring and ligand, spacers, and counter ions on the cytotoxicity and mode of action.

Dissecting Metabolic Functions and Sugar Transporters Using Genome and Transportome of Probiotic Limosilactobacillus fermentum KUB-D18

Background/Objectives:Limosilactobacillus fermentum KUB-D18, a heterofermentative lactic acid bacterium with promising probiotic properties, is known for promoting gut health and nutrient absorption. Originally isolated from chicken intestines, this strain demonstrates versatile metabolic capabilities in diverse gastrointestinal environments. However, the metabolic functions and sugar transport-related genes remain largely unexplored. This study thus aimed to dissect metabolic functions and sugar transports of L. fermentum KUB-D18. Methods: Next-generation and third-generation sequencing techniques using integrative genomic platform towards transportome analysis were performed. Results: The complete genome, sized at 2.12 Mbps with a GC content of 51.36%, revealed 2079 protein-encoding genes, of which 1876 protein functions were annotated and identified in top categories involved in amino acids, nucleotide, energy, and carbohydrate transports and metabolisms. Comparative genes analysis identified 50 core and 12 strain-specific genes linked to probiotic properties, e.g., acid resistances and bile tolerances, antioxidant functions, or anti-inflammatory properties. Further, sugar transportome analysis uncovered 57 transporter genes, demonstrating diverse carbon utilization and phosphotransferase (PTS) systems, corroborated by API 50 CHL test results for carbohydrate metabolism profile. Conclusions: These findings enhance the comprehensive metabolic understanding of L. fermentum KUB-D18, supporting its industrial potential and applications in engineered probiotics.

Disulfidptosis: a new target for central nervous system disease therapy

Disulfidptosis is a pathologic process that occurs under conditions of NADPH deficiency and excess disulfide bonds in cells that express high levels of SLC7A11. This process is caused by glucose deprivation-induced disulfide stress and was first described by cancer researchers. Oxidative stress is a hypothesized mechanism underlying diseases of the central nervous system (CNS), and disulfide stress is a specific type of oxidative stress. Proteins linked to disulfidptosis and metabolic pathways involved in disulfidptosis are significantly associated with diseases of the CNS (neurodegenerative disease, neurogliomas and ischemic stroke). However, the specific mechanism responsible for this correlation remains unknown. This review provides a comprehensive overview of the current knowledge regarding the origin elements, genetic factors, and signaling proteins involved in the pathogenesis of disulfidptosis. It demonstrates that the disruption of thiometabolism and disulfide stress play critical roles in CNS diseases, which are associated with the potential role of disulfidptosis. We also summarize disulfidptosis-related drugs and highlight potential therapeutic strategies for treating CNS diseases. Additionally, this paper suggests a testable hypothesis that might be a promising target for treating CNS diseases.

Marine mussel metabolism under stress: Dual effects of nanoplastics and coastal hypoxia

Emerging challenges in marine environments include nanoplastics (NPs) pollution and coastal hypoxia. Although NPs toxicity in marine organisms is being increasingly documented, the complex interactions between coastal hypoxia and NPs remain largely unexplored. This study investigated the dual effects of polystyrene nanoplastics and different oxygen levels on redox homeostasis and bioenergetics in the marine model organism Mytilus galloprovincialis. Both NPs and hypoxia significantly disrupted redox homeostasis in mussels. Exposure to NPs alone increased electron transport chain activity, whereas exposure to hypoxia alone and co-exposure significantly reduced this activity. Metabolomic analysis showed that NPs primarily affected the pentose phosphate pathway (PPP), tricarboxylic acid (TCA) cycle, and amino acid metabolism; hypoxia exposure alone disrupted the TCA cycle, pyruvate metabolism, and glycolysis/gluconeogenesis, whereas combined exposure notably altered the TCA cycle, PPP, and sugar interconversion. This suggests that regulating these pathways would help mussels cope with the combined environmental stress. Furthermore, co-exposure severely disrupted redox homeostasis and energy metabolism in mussels, suggesting that hypoxia exacerbates NPs toxicity. We believe that these new findings would enhance our understanding of the compounded ecological risks posed by NPs in the context of climate change.

Probiotic Potential of Yeast, Mold, and Intermediate Morphotypes of Geotrichum candidum in Modulating Gut Microbiota and Body Physiology in Mice

Geotrichum candidum, a polymorphic fungus, exists in yeast, mold, and intermediate morphotypes, each with varying genome sizes and phenotypic traits. While G. candidum has been studied as a probiotic in dairy cattle and aquaculture, the differential probiotic potential of its morphotypes has not been fully investigated; therefore, the current study was designed to investigate their impact on the modulation of physiological and gut microbial diversity in BALB/c male mice. In this study, four strains of G. candidum were used, comprising two yeast morphotypes (QAUGC01 and UCMA3730), one mold morphotype (UCMA103), and one intermediate morphotype (UCMA91). BALB/c male mice were administered G. candidum yeast, intermediate, and mold morphotypes via drinking water for 4 weeks. After 4 weeks of experimentation, the yeast morphotype (QAUGC01) notably facilitated healthy weight gain compared to other groups. This was accompanied by significant increases in red blood cell count (p = 0.01). Importantly, QAUGC01 showed no detrimental effects on kidney function, as evidenced by significantly reduced CPK levels (77.25 ± 4.87 U/L) and low cholesterol levels (64.75 ± 0.83 mg/dL). Metagenomic analysis revealed that Firmicutes, Bacteroidetes, and Proteobacteria were predominant bacterial phyla, while Ascomycota and Basidiomycota dominated the fungal populations. Lactobacillus and Bifidobacterium were prominent in the gastrointestinal tract of QAUGC01-treated mice, while Lactococcus correlated with intermediate and mold morphotypes. Predictive functional annotation (PICRUSt2) has revealed the maximum relative abundance of metabolic pathways in mold and intermediate-supplemented mice gut. In contrast, the yeast morphotype (UCMA3730) exhibited a higher metabolic pathway activity in the large intestine. Conclusively, yeast morphotypes increase beneficial bacterial diversity, including Brevibacillus and Bacillus, particularly lactic acid bacteria throughout the gastrointestinal tract. These findings suggest that different G. candidum morphotypes have distinct probiotic potentials, with implications for enhancing gut health in food and feed applications.

1,3,4-oxadiazoles with effective anti-mycobacterial activity

The search for new drugs to treat tuberculosis and nontuberculous mycobacteria (NTM)-caused diseases is still desired. This is the first study aimed at determining the activity of two innovative synthetic 1,3,4-oxadiazole molecules, (4-[cyclohexyl(ethyl) sulfamoyl]-N-[5-(furan-2-yl)-1,3,4-oxadiazol-2-yl]benzamide), namely LMM11, and ((N-cyclo-hexyl-N-ethylsulfamoil)-N-(5- (4-fluorophenyl)-1,3,4-oxadiazol-2-il) benzamide), namely LMM6, against Mycobacterium tuberculosis and nontuberculous mycobacteria, and their ability to present synergism in activity against M. tuberculosis when combined with anti-TB drugs. In vitro cytotoxicity studies were conducted in HeLa and VERO cells. The minimum inhibitory concentration (MIC) and combinatory effect were carried out in M. tuberculosis H37Rv and resistant isolates, NTM, and other genera of bacteria. The LMM6 and LMM11 MIC ranged from 8.27 to 33.07 µM and 15.58 to 70.30 µM in M. tuberculosis, respectively. LMM6 showed activity against M. smegmatis mc2 155 (8.25 μM), M. szulgai (2.05 μM), and M. kansasii (66.03 μM), while LMM11 showed activity against M. szulgai (8.77 μM), and M. smegmatis (70.19 μM). Synergism and modulatory activity of LMM6 and LMM11 with anti-TB drugs were observed, and they showed to be more selective for mycobacteria than HeLa and VERO cells. Both new oxadiazoles showed activity against mycobacteria, in fact, more pronounced against M. tuberculosis, and seem to bring light to the synthesis of new antimicobacterial.

Redox regulation of focal adhesions

Focal adhesions (FAs), multi-protein complexes that link the extracellular matrix to the intracellular cytoskeleton, are key mediators of cell adhesion, migration, and proliferation. These dynamic structures act as mechanical sensors, transmitting stimuli from the extracellular to intracellular environment activating in this way signaling pathways and enabling cells to adapt to environmental changes. As such, FAs are critical for tissue organization and serve as hubs governing cell spatial arrangement within the organism. The assembly, reactivity, and functional regulation of FAs are tightly controlled by post-translational modifications, including redox modulation by reactive oxygen and nitrogen species. Increasing evidence suggests that redox signaling plays a pivotal role in both the physiological and pathological functions of FAs and their downstream processes. Redox regulation affects various components of the FA complex, including integrins, focal adhesion kinase 1 (FAK1), SRC, adapter proteins, and cytoskeletal elements. In this review, we provide an updated overview of the complex interplay between redox signaling and post-translational modifications in FAs. We explore how redox reactions influence the structure, dynamics, and function of FAs, shedding light on their broader implications in health and disease.

Cotargeting of thioredoxin 1 and glutamate-cysteine ligase in both imatinib-sensitive and imatinib-resistant CML cells

Chronic myeloid leukemia (CML) is a type of malignancy characterized by harboring the oncogene Bcr-Abl, which encodes the constitutively activated tyrosine kinase BCR-ABL. Although tyrosine kinase inhibitors targeting BCR-ABL have revolutionized CML therapy, native and acquired drug resistance commonly remains a great challenge. Thioredoxin 1 (Trx1) and glutamate-cysteine ligase (GCL), which are two major antioxidants that maintain cellular redox homeostasis, are potential targets for cancer therapy and overcoming drug resistance. However, how their inhibition is implicated in CML is still unclear. Here, our results revealed that Trx1 was overexpressed in patients with CML compared with healthy donors. Trx1 expression was greater in imatinib-resistant CML cells than in imatinib-sensitive cells. Pharmacological inhibitors of Trx1 attenuated cell growth and reduced colony formation in both imatinib-sensitive and imatinib-resistant CML cells. Furthermore, decreased Trx1 expression enhanced the cytotoxicity of the GCL inhibitor buthionine sulfoximine (BSO). We surmise that the combined inhibition of Trx1 and GCL promotes the induction of hydrogen peroxide and depletes GPX4 expression in CML cells, resulting in ferroptosis in cancerous cells. Finally, the combined inhibition of Trx1 and GCL had a synergistic effect on CML cells in murine xenograft models. These findings offer crucial informationregarding the combined roles ofTrx1 and GCL in triggering ferroptosis in CML and suggestefficacioustherapeutic uses for these systems in this disease.

Effects of environmentally relevant concentrations of glyphosate and aminomethylphosphonic acid on biotransformation and stress response proteins in the liver of zebrafish (Danio rerio)

Herbicides pose a threat to various non-target organisms, including fish. A widely used herbicide, glyphosate, and its main breakdown product, aminomethylphosphonic acid (AMPA), are quite ubiquitous in freshwater systems. The aim of this work was to analyze changes in the relative abundance of hepatic proteins participating in the biotransformation and response to chemical stress in adult zebrafish Danio rerio exposed to environmentally relevant concentrations of glyphosate (100 μg/L), AMPA (100 μg/L), and their mixture (50 μg/L + 50 μg/L) for two weeks. Proteomic analysis showed that the tested concentrations caused dysregulation of various biotransformation proteins, the most upregulated of which in all treatment groups was the Phase I enzyme cyp27a7. While glyphosate had a more pronounced impact on the biotransformation pathways, AMPA showed stronger interference with redox homeostasis. When acting together, the parent compound and its metabolite were more potent to disturb fish metabolic processes, including nucleotide metabolism and proteasome pathway, and to downregulate proteins known for their roles in protection from oxidative modifications of cellular constituents and disruption of redox signaling.

Auranofin induces disulfide bond-mimicking S-Au adducts in protein thiol pairs

Auranofin is an inhibitor of human thioredoxin reductase, clinically used in the treatment of rheumatoid arthritis. More recently, it has been shown to possess strong antibacterial activity. Despite the structural dissimilarity and the independent evolutionary origins of human thioredoxin reductase and its bacterial counterpart (TrxB), inhibition of bacterial thioredoxin reductase is often suggested to be a major factor in auranofin's antibacterial mode of action. To test this hypothesis, we attempted to determine the mechanism of inhibition of auranofin for bacterial TrxB in the presence of thioredoxin, TrxB's natural substrate. However, the data obtained in these experiments was not consistent with a specific and exclusive interaction between TrxB and auranofin. Instead, it suggested that auranofin directly interacts with the cysteine thiols in thioredoxin, TrxB's substrate. Using the fluorescent redox protein roGFP2, we showed that auranofin does indeed directly interact with cysteine pairs in proteins, forming a thiol modification that is similar to, but clearly distinct from a disulfide bond. The Au:protein stoichiometries of auranofin-treated roGFP2 and thioredoxin strongly suggest the presence of an S-Au-S bridge between two cysteines in those proteins. These S-Au adducts form independent of thioredoxin reductase at a rate that indicates their pertinence in auranofin's antibacterial mode of action.

Trp31 Residue of Trx-1 Is Essential for Maintaining Antioxidant Activity and Cellular Redox Defense Against Oxidative Stress

Thioredoxin-1 (Trx-1) is an important redox protein found in almost all prokaryotic and eukaryotic cells, which has a highly conserved active site sequence: Trp-Cys-Gly-Pro-Cys. To investigate whether the Trp31 residue is essential for the antioxidant activity of human Trx-1 (hTrx-1), we mutated Trx-1 by replacing Trp31 with Ala31 (31Ala) or deleting Trp31 residue (31Del). We introduced 31Ala and 31Del mutations into prokaryotic cells for hTrx-1 protein expression, protein purification and evaluation of antioxidant activity. The results showed that neither the replacing mutation to Ala31 nor the deletion of Trp31 residue affected the efficient expression of hTrx-1 protein in prokaryotic cells, indicating that neither form of Trp31 mutation would disrupt the folded structure of the Trx-1 protein. Comparison of the antioxidant activity of purified hTrx-1 proteins of wild-type, 31Ala and 31Del forms revealed that both mutant forms significantly decreased the antioxidant capacity of hTrx-1. Further investigations on eukaryotic cells showed that H2O2 treatment caused massive cell death in EA.Hy926 human endothelial cells with 31Ala and 31Del mutations compared to wild-type cells, which was associated with increased ROS production and downregulation of antioxidant Nrf2 and HO-1 expression in the mutant cells. These results suggested that mutations in the Trp31 residue of hTrx-1 remarkably disrupted cellular redox defense against oxidative stress. The antioxidant activity of hTrx-1 relies on the thiol-disulfide exchange reaction, in which the content of thiol groups forming disulfide bonds in hTrx-1 is critical. We found that the content of free thiol groups specifically participating in disulfide bond formation was significantly lower in Trp31 mutant hTrx-1 than in wild-type hTrx-1; that was speculated to affect the formation of disulfide bonds between Cys32 and Cys35 by virtual analysis, thus abolishing the antioxidant activity of hTrx-1 in cleaving oxidized groups and defending against oxidative stress. The present study provided valuable insights towards understanding the importance of Trp31 residue of hTrx-1 in maintaining the correct conformation of the Trx fold structure, the antioxidant functionality of hTrx-1 and the cellular redox defense capability against oxidative stress.

Structure and Function Analyses of the Thioredoxin 2 and Thioredoxin Reductase Gene in Pacific White Shrimp (Litopenaeus vannamei)

The thioredoxin (Trx) system is one of the most significant systems in living organisms as it regulates cellular redox reactions and plays a pivotal protective role within the cell by promoting redox homeostasis. Trx and thioredoxin reductase (TrxR) are the core oxidoreductases of the Trx system. In this study, the novel full-length cDNAs of LvTrx2 and LvTrxR were cloned from Litopenaeus vannamei. The ORFs of LvTrx2 and LvTrxR were 453 bp and 1785 bp, encoding polypeptides consisting of 150 and 596 amino acids. Sequence alignment analysis revealed that the amino acid sequence of LvTrx2 shared a high degree of identity (93%) with that of Penaeus chinensis, while in LvTrxR, it exhibited a similarity level of 95% with previously submitted Penaeus chinensis and Penaeus monodon sequences. Regarding tissue-specific expression patterns, LvTrx2 showed its highest expression levels in hepatopancreas and gill. For LvTrxR, the highest expression was observed in gill followed by hepatopancreas and intestine. During exposure to ammonia-N, there was a significant upregulation in the relative mRNA levels of LvTrx2 and LvTrxR in hepatopancreas and gill, with the peak values occurring at 24 h or 48 h of exposure. After LPS injection, the LvTrx2 and LvTrxR transcripts in hepatopancreas and gill had different upregulated levels. These findings suggest that LvTrx2 and LvTrxR play pivotal roles in enhancing stress resistance and bolstering antibacterial defense mechanisms in L. vannamei. To explore the roles, LvTrx2 expression was knocked down in vivo to verify the defense mechanism against 4-NP stress. LvTrx2 silencing in 4-NP-challenged shrimp could significantly induce the gene expression of antioxidant-related genes (except for LvTrxR) and aggravate the oxidative damage of lipids. This study suggests that the Trx system is involved in regulating the antioxidant processes, and LvTrx2 and LvTrxR play a vital role in defense responses against environmental stress.

Single-Nucleotide Polymorphisms in the Thioredoxin Antioxidant System and Their Association with Diabetic Nephropathy in Slovenian Patients with Type 2 Diabetes-A Preliminary Study

Diabetic nephropathy (DN) is a microvascular complication of type 2 diabetes mellitus (T2DM) that develops after years of T2DM and affects approximately one in four diabetic patients. Thioredoxin (TXN), thioredoxin reductase (TXNRD), and thioredoxin-interacting protein (TXNIP) are part of the thioredoxin antioxidant system, which is involved in DN. We included 897 Slovenian patients with T2DM lasting more than 10 years in our preliminary study. In total, 344 patients with DN were included in our case group, while 553 without DN comprised our control group. The genotypes of TXN2 rs8140110, TXNRD2 rs1548357, and TXNIP rs7212 were determined for all participants using real-time PCR. We found a statistically significant association between the T allele of the TXN2 rs8140110 polymorphism and DN (p < 0.001; OR: 0.52; 95% CI: 0.36-0.74). The TT and TC genotypes were also significantly less likely to develop DN in comparison to the CC genotype according to the dominant model of inheritance (p < 0.001; OR: 0.51; 95 CI: 0.34-0.75). We did not find a statistically significant association between rs1548357 or rs7212 and DN. To conclude, the rs8140110 polymorphism in the TXN2 gene is associated with DN in Slovenian patients with T2DM.

LMNA R482L mutation causes impairments in C2C12 myoblasts subpopulations, alterations in metabolic reprogramming during differentiation, and oxidative stress

LMNA mutations causing classical familial partial lipodystrophy of Dunnigan type (FPLD2) usually affect residue R482. FPLD is a severe metabolic disorder that often leads to cardiovascular and skeletal muscle complications. How LMNA mutations affect the functional properties of skeletal muscles is still not well understood. In the present project, we investigated the LMNA-R482L mutation-specific alterations in a transgenic mouse C2C12 cell line of myoblasts. Using single-cell RNA sequencing we have studied transcriptional diversity of cultured in vitro C2C12 cells. The LMNA-R482L mutation induces changes in C2C12 cluster composition and increases the expression of genes related to connective tissue development, oxidative stress, stress defense, and autophagy in a population-specific manner. Bulk RNA-seq confirmed these results and revealed the dysregulation of carbohydrate metabolism in differentiated R482L myotubes that was supported by ATP production profile evaluation. The measurement of reactive oxygen species (ROS) levels and glutathione accumulation in myoblasts and myotubes indicates R482L mutation-related dysregulation in mechanisms that control ROS production and scavenging through antioxidant glutathione system. The increased accumulation of autophagy-related structures in R482L myoblasts was also shown. Overall, our experiments showed a connection between the redox status and metabolic alterations with skeletal muscle pathological phenotypes in cells bearing pathogenic LMNA mutation.

Coagulopathy prediction in traumatic brain injury

Traumatic brain injury (TBI) represents a significant public health concern. Besides the initial primary injury, a defining point of TBI is causing secondary, delayed damage through inflammatory biochemical processes. Among the complications arising from this inflammatory response, coagulopathy emerges as a critical concern. With an overall prevalence of 32.7 %, TBI-induced coagulopathy significantly contributes to increased mortality rates and unfavorable patient outcomes, through its clinical manifestations, such as progressive hemorrhagic injury (PHI). This chapter investigates biomarkers capable of accurately detecting coagulopathy and PHI in TBI, evaluating their potential utility based on statistical evidence from various studies and exploring their possible association in the biochemical processes guiding or following TBI-induced coagulopathy. Notably, glucose emerges as a standout candidate, exhibiting a sensitivity of 91.5 % and specificity of 87.5 % for predicting coagulopathy. Furthermore, interleukin-33, with a sensitivity of 93.3 % and specificity of 66.7 %, and galectin-3, with a sensitivity of 67.7 % and specificity of 85.5 %, are promising for PHI. Despite these encouraging findings, significant efforts remain necessary to translate biomarker diagnostic utility into clinical practice effectively. Further research and validation studies are imperative to elucidate the intricate biochemical processes underlying TBI-induced coagulopathy and to refine the clinical application of biomarkers for improved patient management and outcomes in real-world settings.

Synergistic Enhancement of Ferroptosis via Mitochondrial Accumulation and Photodynamic-Controlled Release of an Organogold(I) Cluster Prodrug

Effective delivery and controlled release of metallo-prodrugs with sustained activation and rapid response feed the needs of precise medicine in metal chemotherapeutics. However, gold-based anticancer drugs often suffer from detoxification binding and extracellular transfer by sulfur-containing peptides. To address this challenge, we integrate a thiol-activated prodrug strategy of newly prepared hypercoordinated carbon-centered gold(I) clusters (HCGCs) with their photosensitization character to augment the mitochondrial release of Au(I) in tumors. In contrast to the distorted [CAu4] kernel of a pentanuclear HCGC compound [A5], its dimeric congener [A9] exhibits a symmetrical [{CAu4}-Au-{CAu4}] structure with a remarkable hypercarbon-to-Au4 electron donation. This unique arrangement results in a microsecond long metal-metal-to-ligand charge transfer excited state relative to the nanosecond intraligand excited state of [A5]. Upon light irradiation at 560 nm, [A9] generates active 1O2 to oxidize glutathione (GSH) into poorly coordinating GSSG in the cytoplasm and finally promotes subcellular delivery of HCGCs to mitochondria. Moreover, GSH further triggers consecutive release of active [AuPPh3]+ ions to inhibit cytoplasmic glutathione peroxidase GPX4 and mitochondrial thioredoxin reductase TrxR2, which collectively result in accelerated ferroptosis of human bladder cancer EJ cells and show excellent antitumor performance in mouse bladder tumor models.

Insights into the hydrogen-fueled bioreduction of vanadium(V) by marine Shewanella sp. FDA-1: Process and mechanism

Microbial-driven V(V) reduction plays a crucial role in its biogeochemical cycle, yet the mechanisms underlying this bioreduction remain inadequately understood. While the effectiveness of organic compounds as electron donors in facilitating bacterial reduction of V(V) has been established, the role of inorganic electron donors in initiating this process at the level of pure cultured bacteria has not been explored. In this study, we report on a marine Shewanella sp. FDA-1 that utilizes hydrogen (H2) as an energy source to reduce V(V). In addition, the reduction mechanism was investigated through a combination of genomics, RT-qPCR, heterologous expression of key proteins, extracellular secretion analyses, and electron transfer activity assays. Our results demonstrate that H2 serves as an effective electron donor, enabling Shewanella sp. FDA-1 to reduce V(V) across various salinities (2-7 %) and pH values (5-9). When exposed to 5 mM V(V), the presence of 1-20 mL of H2 resulted in V(V) bioreduction rates ranging from 0.039 to 0.11 h-1 (R2 > 0.73). Amorphous V(IV) compounds were characterized as reduction products using XRD, XPS, FTIR, and SEM. Mechanistic studies indicate that the glutathione system, cytochromes, and extracellular substances such as riboflavin play important roles in V(V) reduction (p < 0.05). Furthermore, our findings reveal that the addition of H2 and lactate triggers different response sequences among these three reduction pathways, suggesting distinct reduction mechanisms between organic and inorganic electron donors. These insights enhance our understanding of microbial vanadium transformation and provide valuable guidance for developing novel H2-based remediation technologies for vanadium-contaminated environments.

Vitamin C: From Self-Sufficiency to Dietary Dependence in the Framework of Its Biological Functions and Medical Implications

Vitamin C is an organic compound biosynthesized in plants and most vertebrates. Since its discovery, the benefits of vitamin C use in the cure and prevention of various pathologies have been frequently reported, including its anti-oxidant, anti-inflammatory, anticoagulant, and immune modulatory properties. Vitamin C plays an important role in collagen synthesis and subsequent scurvy prevention. It is also required in vivo as a cofactor for enzymes involved in carnitine and catecholamine norepinephrine biosynthesis, peptide amidation, and tyrosine catabolism. Moreover, as an enzymatic cofactor, vitamin C is involved in processes of gene transcription and epigenetic regulation. The absence of the synthesis of L-gulono-1,4-lactone oxidase, a key enzyme in the pathway of vitamin C synthesis, is an inborn metabolism error in some fishes and several bird and mammalian species, including humans and non-human primates; it is caused by various changes in the structure of the original GULO gene, making these affected species dependent on external sources of vitamin C. The evolutionary cause of GULO gene pseudogenization remains controversial, as either dietary supplementation or neutral selection is evoked. An evolutionary improvement in the control of redox homeostasis was also considered, as potentially toxic H2O2 is generated as a byproduct in the vitamin C biosynthesis pathway. The inactivation of the GULO gene and the subsequent reliance on dietary vitamin C may have broader implications for aging and age-related diseases, as one of the most important actions of vitamin C is as an anti-oxidant. Therefore, an important aim for medical professionals regarding human and animal health should be establishing vitamin C homeostasis in species that are unable to synthesize it themselves, preventing pathologies such as cardiovascular diseases, cognitive decline, and even cancer.

The adaptation mechanism of desert soil cyanobacterium Chroococcidiopsis sp. to desiccation

Desiccation is a common stress for organisms living in desert soil. Chroococcidiopsis sp. is the dominant species in the soil microbial community of desert regions. Some species of Chroococcidiopsis sp. are highly tolerant to desiccation, making them a good biological system for soil restoration in desert regions, but their adaptation mechanisms to desiccation are not well understood. In this study, different desiccation levels of desert regions were simulated in terms of relative humidity to investigate the adaptation of desert cyanobacterium Chroococcidiopsis sp. ASB-02 to desiccation. Chroococcidiopsis sp. ASB-02 exhibited the ability to rapidly restore PSII activity under desiccation-rehydration conditions. Desiccation-induced oxidative stress is a common feature and the Chroococcidiopsis sp. ASB-02 activated diverse antioxidant genes to eliminate oxidative products. When exposed to desiccation-induced water stress, Chroococcidiopsis sp. ASB-02 can slow water loss and regulate osmotic pressure by enhancing the synthesis of exopolysaccharides and intracellular sucrose. However, under extreme desiccation stress, trehalose is crucial in regulating the osmotic potential of Chroococcidiopsis sp. ASB-02. When the relative humidity is ≤ 56%, with the continuous loss of cellular water, Chroococcidiopsis sp. ASB-02 responds to reduced metabolic activity in the cell by initiating energy-saving pathways and enhancing transcription mechanisms. This study provides a theoretical basis for understanding the adaptation mechanisms of desert cyanobacterium Chroococcidiopsis sp., which is important for soil restoration in desert regions.

Ca2+/calmodulin signaling in organismal aging and cellular senescence: Impact on human diseases

Molecular mechanisms of aging processes at the level of organisms and cells are in the focus of a large number of research laboratories. This research culminated in recent breakthroughs, which contributed to the better understanding of the natural aging process and aging associated malfunctions leading to age-related diseases. Ca2+ in connection with its master intracellular sensor protein calmodulin (CaM) regulates a plethora of crucial cellular processes orchestrating a wide range of signaling processes. This review focuses on the involvement of Ca2+/CaM in cellular mechanisms, which are associated with normal aging, as well as playing a role in the development of diseases connected with signaling processes during aging. We specifically highlight processes that involve inactivation of proteins, which take part in Ca2+/CaM regulatory systems by oxygen or nitrogen free radical species, during organismal aging and cellular senescence. As examples of organs where aging processes have recently been investigated, we chose to review the literature on molecular aging processes with involvement of Ca2+/CaM in heart and neuronal diseases, as well as in cancer and metabolic diseases, all deeply affected by aging. In addition, this article focuses on cellular senescence, a mechanism that may contribute to aging processes and therefore has been proposed as a target to interfere with the progression of age-associated diseases.

MITOCDNB DECREASES PLATELET ACTIVATION THROUGH ITS SELECTIVE ACTION ON MITOCHONDRIAL THIOREDOXIN REDUCTASE

Platelet inhibition is a fundamental objective to prevent and treat thrombus formation. Platelet activation depends on mitochondrial function. This study aims to identify a new mitochondria-targeting compound with antiplatelet activity at safe concentrations in vitro. Cytotoxicity and viability tests were performed on human platelets from volunteer donors, together with experiments on aggregation, platelet activation, mitochondrial function, mitochondrial respiration, and thioredoxin reductase 2 (TrxR2) enzymatic activity in isolated platelet mitochondria. The compound MitoCDNB, corresponding to the molecule 5-chloro-2,4-dinitrophenylamino linked with triphenylphosphonium cation (TPP+) by a butyl chain and methanesulfonate as the counterion, was evaluated. MitoCDNB demonstrates potent, high mitochondria-selective antiplatelet effects that provide a novel approach to platelet inhibition with potentially minimized systemic risks. Here, we describe the first compound that inhibits platelet activation by decreasing TrxR2 enzymatic activity and collagen-stimulated maximal mitochondrial respiration, preventing aggregation and platelet activation. These results can be used to develop new antiplatelet drugs targeting mitochondria.

ZnO‐CuS/F127 Hydrogels with Multienzyme Properties for Implant‐Related Infection Therapy by Inhibiting Bacterial Arginine Biosynthesis and Promoting Tissue Repair

Implant‐related infections are characterized by the formation of bacterial biofilms. Current treatments have various drawbacks. Nanozymes with enzyme‐like activity can produce highly toxic substances to kill bacteria and remove biofilms without inducing drug resistance. However, it is difficult for current monometallic nanozymes to function well in complex biofilm environments. Therefore, the development of multimetallic nanozymes with efficient multienzyme activities is crucial. In the present study, bimetallic nanozyme, ZnO‐CuS nanoflowers with peroxidase (POD), glutathione oxidase (GSH‐Px), and catalase (CAT) activity are successfully synthesized via calcination and loaded into F127 hydrogels for the treatment of implant‐related infections. The ability of ZnO‐CuS nanoflowers to bind bacteria is key for efficient antimicrobial activity. In addition, ZnO‐CuS nanoflowers with H2O2 disrupt the metabolism of MRSA, including arginine synthesis, nucleotide excision repair, energy metabolism, and protein synthesis. ZnO‐CuS/F127 hydrogel in combination with H2O2 has been demonstrated to be effective in clearing biofilm infection and facilitating the switch of M1 macrophages to M2‐repairative phenotype macrophages for the treatment of implant infections in mice. Furthermore, ZnO‐CuS/F127 hydrogels have favorable biosafety, and their toxicity is negligible. ZnO‐CuS/F127 hydrogel has provided a promising biomedical strategy for the healing of implant‐related infections, highlighting the potential of bimetallic nanozymes for clinical applications.

A comprehensive review of peroxiredoxin 4, a redox protein evolved in oxidative protein folding coupled with hydrogen peroxide detoxification

Peroxiredoxin (PRDX) primarily employs electrons from thioredoxin in order to reduce peroxides. PRDX4 mainly resides either in the endoplasmic reticulum (ER) lumen or in extracellular spaces. Due to the usage of alternative promoters, a first exon is transcribed from different regions of the Prdx4 gene, which results in two types of mRNAs. The first type is designated as Prdx4. It is translated with a cleavable, hydrophobic signal sequence and is expressed in most cells throughout the body. The second type is designated as Prdx4t. The peroxidase activity of PRDX4 is involved in both the reduction of hydrogen peroxides and in the oxidative folding of nascent proteins in the ER. Prdx4 appears to have evolved from an ancestral gene in Eutherians simultaneously with the evolution of sperm protamine to cysteine-rich peptides, and, therefore, the testis-specific PRDX4t is likely involved in spermatogenesis through the oxidative folding of protamine. The dysfunction of PRDX4 leads to oxidative damage and ER stress, and is related to various diseases including diabetes and cancer. In this review article we refer to the results of biological and medical research in order to unveil the functional consequences of this unique member of the PRDX family.

Time Course of Mitochondrial Antioxidant Markers in a Preclinical Model of Severe Penetrating Traumatic Brain Injury

Traumatic brain injury (TBI) results from external mechanical forces exerted on the brain, triggering secondary injuries due to cellular excitotoxicity. A key indicator of damage is mitochondrial dysfunction, which is associated with elevated free radicals and disrupted redox balance following TBI. However, the temporal changes in mitochondrial redox homeostasis after penetrating TBI (PTBI) have not been thoroughly examined. This study aimed to investigate redox alterations from 30 min to two-weeks post-injury in adult male Sprague Dawley rats that experienced either PTBI or a Sham craniectomy. Redox parameters were measured at several points: 30 min, 3 h, 6 h, 24 h, 3 d, 7 d, and 14 d post-injury. Mitochondrial samples from the injury core and perilesional areas exhibited significant elevations in protein modifications including 3-nitrotyrosine (3-NT) and protein carbonyl (PC) adducts (14-53%, vs. Sham). In parallel, antioxidants such as glutathione, NADPH, peroxiredoxin-3 (PRX-3), thioredoxin-2 (TRX-2), and superoxide dismutase 2 (SOD2) were significantly depleted (20-80%, vs. Sham). In contrast, catalase (CAT) expression showed a significant increase (45-75%, vs. Sham). These findings indicate a notable imbalance in redox parameters over the two-week post-PTBI period suggesting that the therapeutic window to employ antioxidant therapy extends well beyond 24 h post-TBI.

Selenium and Selenoproteins: Mechanisms, Health Functions, and Emerging Applications

Selenium (Se) is an essential trace element crucial for human health that primarily functions as an immunonutrient. It is incorporated into polypeptides such as selenocysteine (SeC) and selenomethionine (SeMet), two key amino acids involved in various biochemical processes. All living organisms can convert inorganic Se into biologically active organic forms, with SeMet being the predominant form and a precursor for SeC production in humans and animals. The human genome encodes 25 selenoprotein genes, which incorporate low-molecular-weight Se compounds in the form of SeC. Organic Se, especially in the form of selenoproteins, is more efficiently absorbed than inorganic Se, driving the demand for selenoprotein-based health products, such as functional foods. Se-enriched functional foods offer a practical means of delivering bioavailable Se and are associated with enhanced antioxidant properties and various health benefits. Recent advancements in selenoprotein synthesis have improved our understanding of their roles in antioxidant defense, cancer prevention, immune regulation, anti-inflammation, hypoglycemia, cardiovascular health, Alzheimer's disease, fertility, and COVID-19. This review highlights key selenoproteins and their biological functions, biosynthetic pathways, and emerging applications while highlighting the need for further research.

Structural elucidation of an active arabinoglucan from Gomphrena globosa and its protection effect and mechanism against metabolic dysfunction-associated steatohepatitis

The flower of Gomphrena globosa (G. globosa.) is used as Chinese traditional medicine and functional food. Extractions from G. globosa. have been reported to exert hepatoprotective effects. We further hypothesized that the polysaccharide components, as a bioactive ingredient, might have anti-fatty and hepatitis function. Here, a novel homogeneous arabinoglucan GGL0.05S1 (Mw = 83.9 kDa) from this flower, was characterized by monosaccharide composition analysis, methylation analysis, and NMR. Structural analysis showed that the backbone of GGL0.05S1 consists of →4)-α-Glcp-(1→ and →4,6)-α-Glcp-(1→ residues, and the branched chain linked to the main chain via C-6 of →4,6)-α-Glcp-(1→ in the form α-Araf-(1→[4)-α-Glcp-(1]b→ (b > 2). In vitro experiments demonstrated that GGL0.05S1 could inhibit lipid deposition and ROS overload in free fatty acid-induced hepatocytes, meanwhile in vivo tests showed that GGL0.05S1 effectively protected against liver injury, steatohepatitis, and fibrosis in a CDA-HFD-fed MASH model. Mechanism study further uncovered that GGL0.05S1 augmented the expression and antioxidant ability of thioredoxin protein that ameliorated oxidative stress, promoted fatty acid β-oxidation and mitophagy, up to reducing lipotoxicity and alleviating inflammation via inhibiting NLRP3 signaling pathway. Overall, GGL0.05S1 might be a potential novel active compound with liver-protective effect from G. globosa., and which is informative for anti-MASH new drug development.

Reductive stress: The key pathway in metabolic disorders induced by overnutrition

BACKGROUND

The balance of redox states is crucial for maintaining physiological homeostasis. For decades, the focus has been mainly on the concept of oxidative stress, which is involved in the mechanism of almost all diseases. However, robust evidence has highlighted that reductive stress, the other side of the redox spectrum, plays a pivotal role in the development of various diseases, particularly those related to metabolism and cardiovascular health.

AIM OF REVIEW

In this review, we present an extensive array of evidence for the occurrence of reductive stress and its significant implications mainly in metabolic and cardiovascular diseases.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Reductive stress is defined as a shift in the cellular redox balance towards a more reduced state, characterized by an excess of endogenous reductants (such as NADH, NADPH, and GSH) over their oxidized counterparts (NAD+, NADP+, and GSSG). While oxidative stress has been the predominant mechanism studied in obesity, metabolic disorders, and cardiovascular diseases, growing evidence underscores the critical role of reductive stress. This review discusses how reductive stress contributes to metabolic and cardiovascular pathologies, emphasizing its effects on key cellular processes. For example, excessive NADH accumulation can disrupt mitochondrial function by impairing the electron transport chain, leading to decreased ATP production and increased production of reactive oxygen species. In the endoplasmic reticulum (ER), an excess of reductive equivalents hampers protein folding, triggering ER stress and activating the unfolded protein response, which can lead to insulin resistance and compromised cellular homeostasis. Furthermore, we explore how excessive antioxidant supplementation can exacerbate reductive stress by further shifting the redox balance, potentially undermining the beneficial effects of exercise, impairing cardiovascular health, and aggravating metabolic disorders, particularly in obese individuals. This growing body of evidence calls for a reevaluation of the role of reductive stress in disease pathogenesis and therapeutic interventions.

Protozoa-enhanced conjugation frequency alters the dissemination of soil antibiotic resistance

Protozoa, as primary predators of soil bacteria, represent an overlooked natural driver in the dissemination of antibiotic resistance genes (ARGs). However, the effects of protozoan predation on ARGs dissemination at the community level, along with the underlying mechanisms, remain unclear. Here we used fluorescence-activated cell sorting, qPCR, combined with metagenomics and reverse transcription quantitative PCR, to unveil how protozoa (Colpoda steinii and Acanthamoeba castellanii) influence the plasmid-mediated transfer of ARGs to soil microbial communities. Protozoan predation reduced the absolute abundance of plasmids but promoted the expression of conjugation-associated genes, leading to a 5-fold and 4.5-fold increase in conjugation frequency in the presence of C. steinii and A. castellanii, respectively. Excessive oxidative stress, increased membrane permeability, and the provoked SOS response closely associated with the increased conjugative transfer. Protozoan predation also altered the plasmid host range and selected for specific transconjugant taxa along with ARGs and virulence factors carried by transconjugant communities. This study underscores the role of protozoa in the plasmid-mediated conjugative transfer of ARGs, providing new insights into microbial mechanisms that drive the dissemination of environmental antibiotic resistance.

Functional characterization of peroxiredoxin 5 from yellowtail clownfish (Amphiprion clarkii): Immunological expression assessment, antioxidant activities, heavy metal detoxification, and nitrosative stress mitigation

Peroxiredoxin 5 (Prdx5) is the last recognized member of Prdx family. It is a unique, atypical, 2-Cys antioxidant enzyme, protecting cells from death caused by reactive oxygen species (ROS). In this study, the Prdx5 ortholog of Amphiprion clarkii (AcPrdx5) was identified and characterized to explore its specific structural features and functional properties. The open reading frame of AcPrdx5 is 573 bp long and encodes 190 amino acids containing a mitochondrial targeting sequence, thioredoxin domain, and two conserved cysteine residues responsible for antioxidant function. The predicted molecular weight and theoretical isoelectric point of AcPrdx5 are 20.3 kDa and 9.01, respectively. AcPrdx5 sequences were found to be highly conserved across the other orthologs from various organisms and it distinctively clustered within the fish Prdx5 subclade of the phylogenetic tree. The expression of AcPrdx5 was ubiquitously detected among twelve tested tissues, with the highest level in the brain. Furthermore, the mRNA levels of AcPrdx5 in the blood and head-kidney tissues were significantly (p < 0.05) upregulated following polyinosinic-polycytidylic acid (Poly I:C), lipopolysaccharide (LPS), and Vibrio harveyi immune challenge. A concentration-dependent antioxidant potential of recombinant AcPrdx5 was observed in insulin disulfide bond reduction, heavy metal detoxification, free radical and hydrogen peroxide (H2O2) scavenging assays. Additionally, AcPrdx5 overexpression in fathead minnow (FHM) cells upregulated the antioxidant-associated gene (Rrm1, MAPK, SOD2, and PRDX1) expression after H2O2 treatment, and promoted cell viability upon arsenic (As) exposure. In macrophages, AcPrdx5 overexpression effectively suppressed substantial nitric oxide production under lipopolysaccharide treatment. Collectively, our results suggest that AcPrdx5 may play roles in both antioxidant defense system and innate immune response against pathogenic invasions in A. clarkii.

Thioredoxin-1 protein interactions in neuronal survival and neurodegeneration

Neuronal cell death remains the principal pathophysiologic hallmark of neurodegenerative diseases and the main challenge for treatment strategies. Thioredoxin1 (Trx1) is a major cytoplasmic thiol oxidoreductase protein involved in redox signaling, hence a crucial player in maintaining neuronal health. Trx1 levels are notably reduced in neurodegenerative diseases including Alzheimer's and Parkinson's diseases, however, the impact of this decrease on neuronal physiology remains largely unexplored. This is mainly due to the nature of Trx1 redox regulatory role which is afforded by a rapid electron transfer to its oxidized protein substrates. During this reaction, Trx1 forms a transient bond with the oxidized disulfide bond in the substrate. This is a highly fast reaction which makes the identification of Trx1 substrates a technically challenging task. In this project, we utilized a transgenic mouse model expressing a Flag-tagged mutant form of Trx1 that can form stable disulfide bonds with its substrates, hence allowing identification of the Trx1 target proteins. Autophagy is a vital housekeeping process in neurons that is critical for degradation of damaged proteins under oxidative stress conditions and is interrupted in neurodegenerative diseases. Given Trx1's suggested involvement in autophagy, we aimed to identify potential Trx1 substrates following pharmacologic induction of autophagy in primary cortical neurons. Treatment with rapamycin, an autophagy inducer, significantly reduced neurite outgrowth and caused cytoskeletal alterations. Using immunoprecipitation and mass spectrometry, we have identified 77 Trx1 target proteins associated with a wide range of cellular functions including cytoskeletal organization and neurodegenerative diseases. Focusing on neuronal cytoskeleton organization, we identified a novel interaction between Trx1 and RhoB which was confirmed in genetic models of Trx1 downregulation in primary neuronal cultures and HT22 mouse immortalized hippocampal neurons. The applicability of these findings was also tested against the publicly available proteomic data from Alzheimer's patients. Our study uncovers a novel role for Trx1 in regulating neuronal cytoskeleton organization and provides a mechanistic explanation for its multifaceted role in the physiology and pathology of the nervous system, offering new insights into the molecular mechanisms underlying neurodegeneration.

Exploring the immunological functions of thioredoxin domain-containing protein 17 (TXNDC17) in chub mackerel (Scomber japonicus): Immune response and cellular redox homeostasis

All organisms have evolved sophisticated antioxidant networks and enzymes to counteract reactive radicals, among which thioredoxin (Trx) systems are especially noteworthy. Thioredoxin domain-containing protein 17 (TXNDC17) is a ubiquitously expressed enzyme with oxidoreductase activity belonging to the Trx protein family. This study successfully uncovered and analyzed the TXNDC17 gene in Scomber japonicus (SjTXNDC17). The gene consists of a 372-base-pair coding sequence that encodes a protein of 123 amino acids, with an estimated molecular weight of 14.1 kDa. Structural analysis revealed that SjTXNDC17 contains a TRX-related protein 14 domain with two redox-responsive cysteine residues in the 42WCPDC46 motif. Spatial expression analysis indicated that SjTXNDC17 had the highest constitutive expression in the brain. Stimulation with polyinosinic-polycytidylic acid (poly I:C), Vibrio harveyi, and Streptococcus iniae, significantly upregulated the mRNA levels of SjTXNDC17 in the head kidney. The antioxidant activity of the recombinant SjTXNDC17 protein was evidenced by 2,2-Diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging, insulin reduction, and cupric ion-reducing antioxidant capacity assays. SjTXNDC17 overexpression in fathead minnow (FHM) cells significantly reduced reactive oxygen species (ROS) levels and decreased apoptosis. The anti-apoptotic effect was driven by the upregulation of the Bcl2 gene and the downregulation of the Bax gene, as well as the suppression of JNK signaling pathway genes. Moreover, overexpression of SjTXNDC17 facilitated M2 polarization and suppressed nitric oxide production in macrophages. Collectively, these results demonstrate that SjTXNDC17 plays a crucial role in both the immune response and cellular redox balance in Scomber japonicus.