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PRDX1 facilitates USP7-dependent stabilization of SCD1 and promotes bladder cancer progression.

Bladder cancer is characterized by redox adaptation and metabolic plasticity, but the mechanisms linking these processes remain incompletely understood. Integrating bulk, single-cell, and spatial transcriptomic analyses, we identified PRDX1 as a malignant epithelial cell-associated factor linked to adverse outcome. Genetic gain- and loss-of-function studies showed that PRDX1 promoted proliferation, motility, and xenograft growth while limiting reactive oxygen species accumulation and mitochondrial apoptosis. Proteomic and biochemical analyses identified an association between PRDX1 and SCD1. PRDX1 prolonged the SCD1 protein half-life without detectably altering SCD1 transcript abundance and increased USP7-SCD1 co-precipitation. USP7 removed K48-linked polyubiquitin chains from SCD1 and prevented its proteasomal degradation, whereas catalytically inactive USP7 failed to deubiquitinate SCD1. Deletion of PRDX1 residues 157-199 weakened its association with SCD1 and reduced USP7-SCD1 co-precipitation. Depletion of SCD1 or USP7 suppressed PRDX1-dependent growth in vitro and in xenografts. These findings support a model in which PRDX1 facilitates USP7-dependent stabilization of SCD1 and promotes bladder cancer progression.

Bladder cancer

Redox Regulation in Glioblastoma: Mechanisms, Biomarkers, and Therapeutic Implications.

Glioblastoma is the most aggressive primary tumor of the central nervous system, characterized by high invasiveness, rapid progression, and a poor prognosis despite the current treatment modalities. Molecular stratification, using biomarkers such as IDH1, TERT, and MGMT, is a crucial step in the 2021 WHO classification for improving diagnosis and prognosis. Oxidative stress, a feature of GB, has been identified as an important factor in the initiation, progression, and resistance to treatment. It occurs due to an imbalance between reactive oxygen species generated by mitochondrial metabolism, NADPH oxidases, and exogenous sources such as ionizing radiation and xenobiotics and antioxidant defense. This imbalance leads to DNA damage, genomic instability, and deregulation of signaling pathways involved in cell proliferation, apoptosis, and tumor progression. This review provides an overview of key oxidative stress biomarkers and their dual roles in tumor suppression and progression. It highlights how oxidative stress contributes to treatment responses and resistance to current GB treatments, including redox-adaptive mechanisms such as the Nrf2-Keap1 pathway, which promotes radioresistance. Finally, it discusses the potential of understanding these mechanisms to develop therapeutic strategies that target redox balance and homeostasis, aiming to overcome resistance and improve survival outcomes for glioblastoma patients.

Humans

Redox Rewiring in Nicotine-Driven Gastric Carcinogenesis: Uncovering ROS-Dependent Oncogenic Circuits.

SIGNIFICANCE: Nicotine from tobacco products, secondhand smoke, and emerging delivery systems remains a major but underappreciated driver of gastric carcinogenesis (GC). Although reactive oxygen species (ROS) have long been implicated in tumor biology, current models incompletely explain how chronic nicotine selectively reprograms gastric epithelial signaling. This review advances the concept of redox rewiring, whereby nicotine establishes a persistent oxidative state that orchestrates multiple oncogenic programs via spatially compartmentalized NOX signaling. RECENT ADVANCES: We synthesize evidence for a unified model wherein nicotine activates nAChR/β-AR signaling, Ca2+ influx, PKC, and compartmentalized NOX-derived ROS to generate distinct oncogenic outputs. Beyond the established NOX/ROS/NF-κB/MAPK-driven IL-8 and MMP-9 axes, we integrate emerging evidence into three interconnected modules governing EMT/metastasis (ABL1/STAT3/COX-2/periostin), survival/chemoresistance (ERK/GLI1/Bcl-2), and invasion/immune evasion (miR-21/PDCD4). Collectively, these circuits suggest that ROS function not merely as damaging byproducts but as spatially organized signaling mediators dictating tumor behavior. CRITICAL ISSUES: A major challenge is distinguishing established mechanisms from incompletely validated models. The three proposed axes are testable hypotheses requiring experimental validation. Most data derive from in vitro studies with nonphysiologic nicotine concentrations, and artifacts from nonspecific ROS probes are common. Compensatory pathway activation and multi-target effects of natural products remain underexplored. FUTURE DIRECTIONS: We outline a precision-redox oncology roadmap linking pathway-specific biomarkers, mechanistically matched natural products, and biomarker-enriched trials. Priorities include genetic validation of the three axes, time-resolved ROS imaging, and pulsed natural product regimens. By reframing nicotine-driven GC as adaptive redox network remodeling, this review provides a framework for prevention, stratification, and next-generation therapy. Antioxid. Redox Signal. 00, 000-000.

gastric cancer

Cyclin-dependent kinase 4 and 6 inhibitors and the breast cancer immune ecosystem: immune remodeling, resistance, and therapeutic reprogramming.

Cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6 inhibitors) combined with endocrine therapy have become a therapeutic backbone for hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer, yet durable disease control is frequently limited by intrinsic and acquired resistance. Canonical tumor-cell mechanisms, including retinoblastoma-pathway escape, cyclin E-cyclin-dependent kinase 2 (CDK2) activation, endocrine adaptation, and phosphoinositide 3-kinase (PI3K)-AKT-mechanistic target of rapamycin (mTOR) signaling, explain only part of this failure because they do not fully capture dynamic immune and stromal remodeling. Preclinical and translational studies indicate that early CDK4/6 inhibition can enhance antigen presentation, activate interferon-related programs, restrain regulatory T cells, and promote a T-cell-inflamed state. These effects are conditional and may not persist during prolonged treatment. Sustained therapy can instead drive heterogeneous resistant niches characterized by stromal remodeling, myeloid recruitment, checkpoint adaptation, and T-cell dysfunction. This immune-state dependence provides a rationale for immune checkpoint blockade, although clinical combinations have shown mixed efficacy and clinically relevant hepatic, pulmonary, and hematologic toxicities. Sequential or lead-in strategies therefore warrant prospective evaluation. Oxidative phosphorylation (OXPHOS) and redox adaptation may sustain selected resistant states and expose context-dependent ferroptotic vulnerabilities. Ferroptosis may connect tumor-cell killing with immune regulation, whereas nanomedicine may improve tumor-selective delivery. Both strategies remain largely preclinical and require further evaluation of pharmacokinetics, biodistribution, toxicity, manufacturability, and immune-cell safety. This Review distinguishes intrinsic from acquired resistance across interpatient, intratumoral, spatial, and temporal dimensions. It integrates tumor-cell escape with cytokine, immune, stromal, vascular, and metabolic remodeling and summarizes emerging therapeutic strategies. We further propose a candidate biomarker-informed framework that integrates genomic profiling, spatial immune architecture, circulating biomarkers, T-cell receptor (TCR) dynamics, transcriptomic and single-cell analyses, artificial intelligence (AI)-assisted multimodal integration, and longitudinal sampling. This framework is intended to support biomarker development and prospective trial design rather than current clinical decision-making, providing a translational basis for testing state-informed and sequence-aware therapeutic strategies.

Humans

Subcellular Proteomic Analyses Reveal REEP5 Knockdown in the Mouse Heart Disrupts Mitochondrial Networks.

Receptor Expression-Enhancing Protein 5 (REEP5) is a cardiac-enriched, membrane-shaping protein localized to the sarco(endo)plasmic reticulum (SR/ER), where it supports membrane network architecture and cardiomyocyte function. While REEP5 has been implicated in calcium handling and contractility, its role in regulating inter-organelle communication and mitochondrial homeostasis remains less well-understood. In this study, we used recombinant adeno-associated virus serotype 9-mediated shRNA knockdown of Reep5 in mouse hearts, combined with subcellular fractionation and data-independent acquisition mass spectrometry, to define proteomic remodeling across microsomal (SR/ER), mitochondrial, and cytosolic compartments. Loss of REEP5 altered the composition of SR/ER membrane-shaping proteins, including upregulation of RTN4, ATL3, and CKAP4, suggesting a partial compensatory response. Microsomal, mitochondrial and cytosolic proteomes exhibited broad reorganization, with enrichment of proteins involved in redox adaptation and proteostasis, alongside depletion of mitochondrial import machinery and antioxidant enzymes. Imaging of isolated cardiomyocytes confirmed fragmented mitochondrial networks and increased reactive oxygen species, consistent with proteomic signatures of disrupted mitochondrial dynamics and oxidative stress. Gene ontology enrichment across all fractions highlighted widespread dysregulation in organelle-specific processes, including translation, protein localization, and metabolic remodeling. Notably, several altered pathways converged on mitochondria-associated membranes, suggesting that REEP5 may support SR/ER-mitochondria tethering and functional crosstalk. These findings position REEP5 as a key regulator of organelle homeostasis in the heart and underscore how its loss disrupts mitochondrial integrity and inter-organelle communication across cellular compartments.

Animals

Genome-resolved analysis reveals disruption of gut microbial vitamin B and K2 biosynthesis during Toxoplasma gondii infection in mice.

UNLABELLED: Toxoplasma gondii infection remodels the gut microbiome, yet its impact on microbial vitamin biosynthetic potential and host redox metabolism remains unclear. Here, we integrated mouse gut metagenomes with publicly available metagenome-assembled genomes (MAGs) to construct a genome-resolved atlas of B-vitamin and vitamin K2 biosynthesis. From 45,697 MAGs, we curated 4,771 representative genomes, of which 2,682 met high-quality criteria (completeness &#x2265;90%, contamination <5%). Functional annotation identified 229,717 vitamin-related genes corresponding to 177 Kyoto Encyclopedia of Genes and Genomes (KEGG) orthologs across de novo pathways for eight B vitamins, thiamine (B1), riboflavin (B2), niacin (B3), pantothenate (B5), pyridoxine (B6), biotin (B7), folate (B9), cobalamin (B12), and vitamin K2. Among the high-quality genomes, 1,665 encoded complete de novo pathways for at least one vitamin, highlighting functional specialization and community-level complementarity. Transcripts per million-normalized metagenomic read counts revealed significant differences in KEGG ortholog abundances across six of the nine vitamin pathways. Reanalysis of metagenomic data from infected mice (acute, chronic, and control; n = 10 per group) revealed a stage-dependent reduction in &#x3b1;-diversity of vitamin biosynthesis pathways during acute infection, and a clear &#x3b2;-diversity separation from chronic and control groups. Core niacin biosynthesis genes (nadB, nadA, nadC) displayed phylum-specific redistribution, indicating selective remodeling of microbial NAD+ precursor production under infection-induced metabolic stress. These results suggest that T. gondii infection disrupts cooperative vitamin biosynthetic networks while specifically modulating niacin pathways linked to host NAD+ metabolism. IMPORTANCE: Gut microbes can synthesize essential vitamins, but how infection alters this function is poorly understood. By integrating mouse gut metagenomes with genome-resolved microbial data, we show that Toxoplasma gondii infection reshapes the vitamin biosynthetic potential of the gut microbiome in a stage-dependent manner. Acute infection reduces the diversity of vitamin biosynthesis pathways and shifts the taxonomic distribution of key niacin biosynthesis genes involved in microbial NAD+ precursor production. These findings identify vitamin metabolism, especially niacin-related pathways, as a sensitive functional axis of microbiome remodeling during infection. Our work links microbial taxonomic changes to functional metabolic consequences and suggests that microbiome-mediated regulation of NAD+-related metabolism may contribute to host redox adaptation during T. gondii infection.

B vitamins

Feedstock-specific effects of sulfur-rich vegetable fractions on food waste anaerobic digestion: Sulfide-associated redox perturbation and adaptive microbial reassembly.

Food waste (FW) anaerobic digestion (AD) is strongly affected by feedstock heterogeneity, yet the role of sulfur-rich vegetable fractions remains poorly defined. Here, garlic (GAR), Chinese cabbage (CHC), and cabbage (CAB) were used as representative sulfur-rich vegetables to assess their effects on methane production, redox status, and microbial function during FW AD. At equal volatile solids loading, GAR showed no significant effect, whereas CHC and CAB caused a biphasic response, with delayed methane accumulation and reduced cumulative yield followed by late-stage daily methane production 39.6% and 45.9% higher than the control, respectively. CHC and CAB promoted sulfide accumulation and elevated reactive oxygen species (ROS) during the early stage. Elevated ROS levels were associated with lower NADH/NAD+ ratios, reduced electron transport activity, and volatile fatty acid accumulation, collectively indicating a redox-perturbed state characterized by functional decoupling between acidogenesis and methanogenesis. Metagenomic analysis showed that this early disturbance was followed by functional reassembly of the community. Hydrolytic-acidogenic bacteria sustained fermentation, accompanied by enrichment of genes associated with PFOR-Rnf-mediated energy conservation and the ED and oxidative PPP pathways, while methanogenesis shifted toward acetoclastic and methylotrophic routes. Genome-resolved analysis attributed the genomic potential for PFOR-Rnf-mediated energy conservation to Aminobacterium and Defluviitoga MAGs, and showed that Methanosarcina possessed the broadest oxidative stress defense repertoire, supporting its dominance after ROS perturbation. These findings provide a mechanistic framework linking sulfur-rich feedstock heterogeneity to methane-production dynamics, involving sulfide-associated redox perturbation and subsequent microbial functional reassembly.

Energy conservation

Metabolic adaptation to hypoxia. Redox state of the cellular free NAD pools, phosphorylation state of the adenylate system and the (Na+-K+)-stimulated ATP-ase in rat liver.

The effect of hypoxia (30 min 10% or 8% O2) on the phosphorylation state and redox state of the cytosol and mitochondria of rat liver were studied. Measurements were made both from normal animals and animals which had been exposed to the reduced partial pressure of oxygen (50.5 kPa or 40.8 kPa of air) for one or seven days. Cytostolic free NAD was reduced in the liver both in acute hypoxia and in hypoxia after one or seven days, i.e. the lactate/pyruvate and sn-glycerol-3-phosphate/dioxyacetonephosphate ratios increased markedly. A marked reduction in the mitochondrial free NAD pool occurred only in acute hypoxia and only a slight reduction was observed in animals kept at 40.8 kPa for one or seven days, as evaluated from the hepatic hydroxybutyrate/acetoacetate ratio. Liver ATP concentration decreased rapidly in acute hypoxia without any significant recovery during one or seven days at 40.8 kPa. The hepatic ATP/ADP X Pi ratio decreased significantly, with a simultaneous decrease in the total adenine nucleotide concentration. A tendency was observed for the ATP/ADP X Pi ratio to return to normal after seven days, i.e. the values in acute hypoxia were significantly smaller than those noted in hypoxia after seven days, demonstrating an adaptation of the energy metabolism during prolonged hypoxia. Hepatic (Na+-K+)-stimulated ATP-ase activity was not affected by hypoxia.

Acetates

Oxidative stress and cancer: current insights and therapeutic implications.

OXIDATIVE STRESS: good or evil? Oxidative stress occurs when the balance between reactive oxygen species (ROS) and antioxidant defenses shifts toward an excess of ROS; while essential in physiological processes, it plays a context-dependent role in cancer, contributing to both the promotion and inhibition of tumorigenesis. Small to moderate amounts of ROS activate pathways supporting tumor progression and proliferation, while large amounts lead to genomic instability and cell death. ROS are generated endogenously and exogenously. In cancer, ROS activate pathways that prompt tumor development (KRAS, MYC, PI3K-Akt-mTOR) and block tumor suppressors (p53, BRCA1), allowing tumorigenesis and drug resistance. They also modulate the tumor microenvironment (TME) by altering tumor, stromal and immune cell interactions, which initiate angiogenesis, epithelial-mesenchymal transition (EMT), inflammation and metastasis. Myeloid-derived suppressor cells (MDSCs) and cancer-associated fibroblasts (CAFs) contribute to ROS-driven immunosuppression. Cancer cells mainly rely on glycolysis and oxidative phosphorylation (OXPHOS) to sustain their energetic and metabolic requirements. Generated ROS act as metabolic byproducts and signaling molecules supporting proliferation and tumorigenesis. Cancer stem cells (CSCs) produce low ROS levels by activating antioxidant pathways and mitochondria remodeling, ensuring recurrence and persistence. There is a redox duality that presents challenges and opportunities for therapies. Pro-oxidant approaches attempt to overwhelm the tumor's defenses, while antioxidants preserve healthy tissues. Advances in targeted redox modulation with immunotherapies improve therapy effectiveness. We propose a new "Adaptive Directed Redox Therapy" (ADRT), which involves a dynamic, feedback-controlled methodology that alternates pro- and antioxidant phases to selectively collapse tumor redox balance while preserving normal tissues.

Humans

Protein persulfidation emerges as a conserved component of the redox response to DNA damage.

Genotoxic stress is frequently accompanied by alterations in cellular redox homeostasis; however, the mechanisms linking redox regulation to the DNA damage response (DDR) remain incompletely understood. Here, we investigated the early redox response to DNA damage induced by methyl methanesulfonate (MMS) in Saccharomyces cerevisiae, focusing on cysteine oxidative post-translational modifications (PTM). We show that activation of the DNA damage response is accompanied by rapid redox changes that occur in the absence of a generalized oxidative stress response. MMS exposure promotes selective remodeling of cysteine oxidative modifications, characterized by decreased free thiols, robust induction of protein persulfidation, and comparatively modest changes in sulfenylation. These alterations are accompanied by increased intracellular hydrogen sulfide levels, supporting the involvement of reactive sulfur species in the cellular response to DNA damage. Proteome-wide analyses revealed that cysteine oxidative modifications preferentially target proteins involved in central metabolism, nucleotide biosynthesis, and genome maintenance. Consistent with these observations, MMS-induced genotoxic stress promotes metabolic adaptation characterized by increased mitochondrial respiration, elevated ATP production, and mitochondrial morphological remodeling, linking bioenergetic adaptation to redox regulation. Importantly, perturbation of intracellular redox balance using N-acetylcysteine compromises survival under DNA-damaging conditions, supporting a functional role for redox signaling during the DDR. Finally, MMS treatment also induces protein persulfidation in mammalian cells. Moreover, exposure to etoposide, a mechanistically distinct genotoxic agent that induces DNA double-strand breaks through topoisomerase II inhibition, showed a similar trend, suggesting that protein persulfidation may not be restricted to alkylation-induced DNA damage. Together our findings identify protein persulfidation as a prominent component of the redox response to DNA damage and provide new insight into the functional interplay between mitochondrial metabolism, cysteine-based redox regulation, and genome maintenance.

Oxidation-Reduction

Adaptive and degenerative mitochondrial remodeling define distinct redox states in age-related macular degeneration.

Age-related macular degeneration (AMD) is associated with mitochondrial dysfunction and oxidative stress, yet the relationship between mitochondrial remodeling, redox homeostasis, and disease progression remains poorly understood. Nonhuman primates (NHPs) develop spontaneous AMD-related phenotypes, including punctate deposits and soft drusen, providing a unique animal model to investigate mitochondrial pathology in the aging retinal pigment epithelium (RPE). We integrated quantitative mitochondrial ultrastructural profiling with flavoprotein fluorescence imaging, plasma metabolomics, and whole-exome sequencing to characterize mitochondrial and redox alterations in aged rhesus macaques with AMD-related lesions. Flavoprotein fluorescence imaging demonstrated increased metabolic heterogeneity in eyes with soft drusen, consistent with altered mitochondrial redox states and oxidative stress. Morphometric analysis identified distinct mitochondrial remodeling patterns across phenotypes. Normal aging was characterized by concentric cristae and type I paracrystalline inclusions. Eyes with punctate deposits exhibited increased mitochondrial fusion-associated morphology, hyperbranching, and type I paracrystalline inclusions, consistent with a stress-responsive mitochondrial remodeling pattern. In contrast, eyes with soft drusen exhibited reduced fusion-associated morphology, reduced structural complexity, and ultrastructural features consistent with mitochondrial deterioration. These ultrastructural patterns were accompanied by distinct plasma metabolomic signatures. Punctate deposits were associated with altered glycolytic, tricarboxylic acid cycle, and redox-buffering metabolites, consistent with differences in stress-responsive metabolism, whereas soft drusen exhibited metabolomic signatures consistent with altered redox homeostasis. Whole-exome sequencing identified a mitochondrial DNA variant, MT:9582G&#x202f;>&#x202f;A, in cytochrome c oxidase subunit III (COX3) associated with the drusen phenotype. Collectively, these findings identify distinct mitochondrial remodeling patterns associated with AMD-related phenotypes in aged rhesus macaques. The convergence of ultrastructural, imaging, metabolomic, and genetic analyses suggests that punctate deposits and soft drusen are associated with different mitochondrial and redox-related responses to chronic retinal stress. These findings provide a framework for future studies investigating mitochondrial biology and redox-driven mechanisms in AMD.

Animals

[Hydrogen metabolism in Anabaena variabilis in the dark].

Cells and extracts of the cyanobacterium Anabaena variabilis are capable of hydrogen absorption in the dark in the presence of H-acceptors with various redox potentials. Preliminary adaptation of the cells to anaerobic conditions has no effect on the process. A. variabilis can also evolve hydrogen in the dark. Reduced methylviologen (RMV), formiate, pyruvate, and glucose may be substrates for hydrogen evolution by the cells. The extracts evolve hydrogen in the presence of RMV, benzylviologen, azocarmine, or NAD (P) H + ATP. No adaptation of the cells to anaerobic conditions is required for hydrogen evolution from RMV, and chloramphenicol has no effect on the process. The rate of hydrogen evolution is however higher in the cells adapted to anaerobic conditions. Production of hydrogen from pyruvate by the cells adapted and non-adapted to anaerobic conditions was detected only after their incubation with the substrate during 2--3 hours, and chloramphenicol inhibited the process.

Cell-Free System

Crosstalk between cysteine and lysine modifications: Integrating redox and metabolic regulation.

Protein post-translational modifications (PTMs) on amino acid residues enable dynamic cellular responses to changes in metabolic and redox state. Cysteine and lysine are among the most extensively modified amino acid residues, with both undergoing a diversity of acylation and oxidative modifications. Indeed, proximal (<10&#x202f;&#xc5;) cysteine and lysine residues may form integration nodes for crosstalk between metabolism and redox homeostasis pathways. This review highlights the interaction of proximal Cys-Lys residues, including influence on residue pKa by local electrostatics, cysteine-to-lysine transfer of PTM moieties, and covalent crosslinking. We discuss candidate Cys-Lys regulatory pairs in proteins involved in redox regulation, proteostasis, metabolic adaptation and inflammation. We further utilize computational modeling to identify proximity between cysteine and lysine residues in proteins known to be regulated by acylation and oxidative PTMs, and to demonstrate changes in these distances and local electrostatic potential due to lysine acetylation. Finally, we review how mass spectrometry-based proteomics and machine-learning PTM predictive tools can enable the identification, validation, and interpretation of proximal Cys-Lys interactions that regulate cellular responses to oxidative challenge and metabolic flux.

Cysteine

[Role of oxidative processes in the realization of the adaptive mechanisms of the human placenta].

Redox reactions were studied in 217 placentas obtained after partus maturus and pathological labor (premature labor, gestoses, incompatibility by Rh antigen, uterine inertia, placentas at early therapeutic and spontaneous abortions). Several uniform alterations were observed in activities of NADP-dependent isocitrate dehydrogenase, lactate-, glutamate- and malate dehydrogenases. Increase in the activity of these enzymes was accompanied by alteration in distribution of LDH isoenzymes and by elevated formation of glutamic acid; activities of transaminases, cytochrome c and cytochrome oxidase were unaltered. The alterations observed appear to be due to activation of compensatory-adaptive mechanisms of placenta.

Abortion, Spontaneous

Involvement of cross-genus phages in bacterial resistance to chlorine disinfection.

Chlorine disinfection resistance in pathogenic microorganisms poses severe environmental concerns and public health risks. While phages play critical roles in host adaptation to environmental stress, how poly-host phages contribute to bacterial resistance to chlorine disinfectants remains poorly understood. Here, we investigated shifts in the population dynamics, transcriptional profiles, and function potentials of cross-genus phage-bacterial communities under exposure to chlorine disinfectants in a continuously operated anaerobic-anoxic-oxic system over a 92-day period, using integrated metagenomic and metatranscriptomic approaches. In the presence and absence of chlorine disinfectants, the genomic abundance and diversity of phage and bacterial communities showed similar variation trends, and the community structures of both exhibited clear differences. A strong significant positive correlation was observed between phage and bacterial diversity under chlorine exposure (R&#x202f;=&#x202f;0.975, p&#x202f;=&#x202f;0.00,057), whereas no significant correlation was detected in the absence of chlorine disinfection (R&#x202f;=&#x202f;-0.314, p&#x202f;=&#x202f;0.613), suggesting that chlorine disinfectants may enhance phage-bacteria interactions. Host-associated phages exhibited high consistency with their corresponding putative hosts in terms of genomic abundance (M2&#x202f;=&#x202f;0.0945, p&#x202f;=&#x202f;0.001) and transcript abundance (M2&#x202f;=&#x202f;0.3668, p&#x202f;=&#x202f;0.001), and they were also significantly correlated with cross-genus phages in both genomic abundance (R&#x202f;=&#x202f;0.97, p&#x202f;<&#x202f;2.2e-16) and transcript abundance (R&#x202f;=&#x202f;0.83, p&#x202f;<&#x202f;2.2e-16), which collectively suggests the critical role of cross-genus phages in the resistance of microbial communities to chlorine disinfectants. Bipartite association network analysis shows that cross-genus phages carry highly homologous genes to their putative hosts and may be involved in the horizontal transfer of these genes among bacteria. These homologous genes are involved in DNA repair, redox balance regulation, environmental stress adaptation and efflux pump functions, suggesting a synergistic role between cross-genus phages and their putative hosts in chlorine resistance. Our findings reveal that cross-genus phages can contribute to the resistance of bacterial communities to chlorine disinfectants, providing the theoretical foundation for evaluating the role of poly-host phages in microbial communities.

Chlorine resistance

Decoding context-dependent sirtuin pharmacology in cancer: Metabolic-epigenetic switches and precision therapeutic targeting.

Sirtuins (SIRT1-SIRT7) are a family of NAD+-dependent lysine deacetylases that possess mono-ADP-ribosyltransferase activity and integrate cellular metabolic status with chromatin regulation, genome maintenance, redox homeostasis, immune responses, and adaptation to cancer therapies. Their translational value has been obscured by a recurring paradox: the same isoform may constrain malignant transformation in one setting yet support metastatic competence, stemness, immune evasion, or drug resistance in another. This review reframes that paradox as a measurable problem of context. We define a SIRT context code in which NAD+ availability and compartmentalization, subcellular localization, PTM state, chromatin occupancy, oncogenic genotype, cell lineage, and tumor microenvironment jointly determine sirtuin output. Using recent mechanistic and translational evidence, we summarize how sirtuins regulate metabolic switching, histone acetylation and lactylation, genome stability, cancer-associated fibroblast programs, regulatory T-cell enrichment, cancer stem-cell plasticity, angiogenesis, and resistance to DNA-damaging, targeted, and immune therapies. We further argue that successful sirtuin pharmacology will require context matching rather than indiscriminate activation or inhibition. Priorities include spatial and single-cell biomarker discovery, compartment-specific NAD+ measurements, PTM-resolved activity assays, structure-guided isoform-selective agents, and degrader strategies targeting non-catalytic scaffolding functions. Sirtuins should therefore be viewed as metabolic-epigenetic decision nodes rather than fixed oncogenes or tumor suppressors. However, the evidence remains predominantly preclinical, and our search identified no clinical-stage oncology trials of direct sirtuin modulators using prospective biomarker stratification, underscoring that this framework remains translationally aspirational rather than clinically validated.

Humans

Salmonella Typhimurium screen identifies shifts in mixed-acid fermentation during gut colonization.

How enteric pathogens adapt their metabolism to a dynamic gut environment is not yet fully understood. To investigate how Salmonella enterica Typhimurium (S.Tm) colonizes the gut, we conducted an in&#xa0;vivo transposon mutagenesis screen in a gnotobiotic mouse model. Our data implicate mixed-acid fermentation in efficient gut-luminal growth and energy conservation throughout infection. During initial growth, the pathogen utilizes acetate fermentation and fumarate respiration. After the onset of gut inflammation, hexoses appear to become limiting, as indicated by carbohydrate analytics and the increased need for gluconeogenesis. In response, S.Tm adapts by ramping up ethanol fermentation for redox balancing and supplying the TCA cycle with &#x3b1;-ketoglutarate for additional energy. Our findings illustrate how S.Tm flexibly adapts mixed fermentation and its use of the TCA cycle to thrive in the changing gut environment. Similar metabolic wiring in other pathogenic Enterobacteriaceae may suggest a broadly conserved mechanism for gut colonization.

Animals