The serine/threonine phosphatase-2 (PP2A) controls mitogen-associated signaling and DNA replication. The WEE1 protein tyrosine kinase controls S phase progression and G2/M phase transition. Databases disclose that the levels of PP2A and WEE1 are associated with poor prognosis of leukemic patients (p = 0,0017/0,025; n = 54-163). We applied advanced, clinically used drugs that block PP2A and WEE1 to human cultured leukemia cells, primary pre-leukemic and chronic myeloid leukemia cells, and pancreatic ductal adenocarcinoma cells. Combined application of the drugs depleted cells in all cell cycle phases, synergistically triggered apoptosis, and evoked the induction of DNA stress foci and mitotic catastrophe. In 93 lymphoid, 40 myeloid, and 47 pancreatic cancer cells, genetic depletion of PP2A-Cα and WEE1 stalls the proliferation of most cells. Unlike cancer cells, normal human immune cells are not killed upon inhibition of PP2A and WEE1. This is linked to higher expression of PP2A and WEE1 in chronic myeloid (n = 274), acute myeloid (n = 1858) and acute lymphoblastic leukemia cells (n = 1817) than in normal blood cells. These data suggest that pharmacological modulators of serine/threonine and tyrosine signaling allow targeted chemotherapy.
Glioblastoma (GB) is one of the most aggressive brain tumours, with low survival rates despite combined radiation and chemotherapy. The blood-brain barrier (BBB) limits the delivery and efficacy of many chemotherapeutic agents, highlighting the need for more effective and alternative therapeutic strategies. 5-Ethynyl-2-deoxyuridine (EdU), a thymidine analogue capable of crossing the BBB, has recently been investigated for its effects on cellular processes in glioma, particularly in relation to replication stress and DNA damage responses. This study aimed to investigate the effects of EdU on apoptosis, autophagy, and cell cycle regulation in U87-MG glioma cells (PTEN mutant, p53 wild-type) using both 2D monolayer and 3D spheroid culture models. EdU exposure significantly reduced glioma cell proliferation and migration, was associated with increased apoptotic markers including cleaved caspase-3, and modulated autophagy-related markers including LC3A, LAMP2A, and HSC70 expression. Moreover, EdU exposure was associated with alterations in epithelial-mesenchymal transition (EMT) markers, including decreased N-cadherin and β-catenin and increased E-cadherin levels, and with reduced nuclear translocation of Hsp70.In 3D spheroid cultures, 50 μM EdU significantly reduced spheroid growth and migration, supporting its biological activity in a physiologically relevant model. These findings suggest that EdU-induced cellular stress responses may represent a potential area for further investigation in glioblastoma, particularly in relation to autophagy and apoptosis. Further studies are warranted to better understand the underlying mechanisms and potential applications of EdU in glioblastoma.
Ageing and interventions modulate health and mortality1, yet the underlying molecular mechanisms of this modulation remain unclear. Here we integrate more than 11,000 transcriptomes from more than 25 tissues across 4 mammals (mouse, rat, macaque and human) to develop accurate, interpretable rodent and multi-species biomarkers of chronological age and expected mortality, predicting lifespan-modulating interventions, time to death, chronic diseases and rejuvenation. Ageing-related changes were conserved across species and cell types, revealing universal transcriptomic signatures of mammalian ageing and mortality, including CDKN1A and LGALS3, whose protein levels were also associated with mortality and multimorbidity in UK Biobank. Mortality-associated features were recapitulated across in vivo and in vitro damage-accumulation models, including inflammation, replicative senescence, metabolic inhibition and γ-irradiation, and were attenuated or reversed by cell immortalization, reprogramming, heterochronic parabiosis and early embryogenesis. Network analysis uncovered a modular architecture of ageing- and mortality-associated hallmarks, encompassing inflammation, interferon signalling, mitochondrial function, chromatin modification and extracellular matrix organization. To quantify ageing of individual cellular components, we developed module-specific clocks, which revealed pathway-specific effects of interventions: chronic diseases primarily accelerated inflammatory-module ageing, whereas caloric restriction and Klotho (also known as Kl) deficiency targeted mitochondrial and metabolic modules. Transcriptomic and DNA methylation clocks showed correlated age acceleration in human blood, which was strongest for the chromatin-associated module clock, highlighting mechanistic links between molecular ageing modalities. This study reveals conserved signatures and a modular architecture of mortality regulation, providing a framework for quantifying and targeting ageing of cellular subsystems across species and tissues.
Head and neck squamous cell carcinoma (HNSCC) frequently resists PD-1 blockade due to an immunologically "cold" tumor microenvironment (TME). Here, we identify Z-DNA binding protein 1 (ZBP1) as a key immunoregulator that reprograms immune-suppressive TMEs. Integrated TCGA/SangerBox analyses revealed ZBP1 as a hub gene strongly correlated with cytotoxic CD8+ T cells (r = 0.48, p < 0.0001) and M1 macrophages (r = 0.39, p < 0.0001). Multi-model validation in 92 HNSCC specimens revealed elevated ZBP1 expression versus normal tissues (p < 0.01), co-localized with infiltrating CD8+/CD4+ T cells and CD68+ macrophages through multiplex immunofluorescence. Clinically, high ZBP1 predicted improved survival (HR = 0.61 for overall survival; HR = 0.45 for disease specific survival; p < 0.0001) and early-stage presentation (p = 0.004). Mechanistically, ZBP1 overexpression in SCC-7/MOC2 models suppressed tumor growth while enhancing IFN-γ+ CD8+ T cell activation and reducing M2 polarization (CD206+: 16.91% vs 38.19% in ZBP1-high vs control, p < 0.001). Single-cell transcriptomics uncovered ZBP1-driven TME remodeling through chemokine signaling networks and expanded effector T cell compartments, validated by 1.49-fold increased CD8+ T cell infiltration via flow cytometry. Spatial analysis revealed ZBP1 overexpression amplified immune cell crosstalk (1.65-fold interaction increase, p < 0.001), upregulating CD8+ T cell chemotaxis (CXCR3/CCR5-CCL5 axis) and effector functions (p < 0.0001). Concurrently, it suppressed immunosuppressive pathways through metabolic reprogramming, establishing ZBP1 as a dual regulator synchronizing lymphocyte recruitment and myeloid suppression. Our integrative approach bridges computational biology with functional validation, demonstrating ZBP1's capacity to convert "cold" tumors into immunologically active niches. This work positions ZBP1 as both a stratification biomarker for checkpoint inhibitor response and a therapeutic target for TME reprogramming in HNSCC.
Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a multidrug-resistant (MDR) pathogen causing severe infections in immunocompromised patients, prompting the exploration of alternative therapies like bacteriophage therapy. In this study, we isolated and characterized a novel halophilic lytic bacteriophage, Halo KS-7, targeting K. pneumoniae, and used an AI-driven annotation pipeline in Python to analyze its genome and therapeutic potential. Bacteriophages were isolated from Hospital wastewater, purified through plaque isolation, and confirmed using the double-layer agar method. Morphological analysis via transmission electron microscopy (TEM) and plaque assays assessed lytic activity. In vitro assays, including one‑step growth curve and MOI determination, were performed to evaluate the replication kinetics and lytic activity of bacteriophage Halo KS‑7 against carbapenem‑resistant Klebsiella pneumoniae. In vivo efficacy was assessed using a BALB/c mouse wound infection model by monitoring wound contraction and performing blinded histopathological analysis following phage treatment. DNA sequencing was done using Illumina HiSeq 2000, followed by genome assembly, AI-guided annotation, gene prediction, protein function classification, and comparative genomics using CLC Genomics Workbench. We also evaluated host range, temperature stability, pH sensitivity, and salt stress tolerance to assess therapeutic potential. Halo KS-7 exhibited strong lytic activity against CRKP and was classified as a Myoviridae bacteriophage by TEM. Phenotypic assays demonstrated optimal activity at 37 °C and neutral pH, effective activity from pH 4-10, and enhanced performance in high-salinity conditions. Bacteriophage Halo KS-7 exhibited a short latent period (~20 min), a modest burst size (5.73 PFU/cell), and optimal antibacterial activity at MOI 0.1, resulting in sustained suppression of K. pneumoniae growth in vitro. In vivo, Halo KS-7 treatment significantly enhanced wound healing in infected BALB/c mice, achieving near-complete wound closure, effective infection control, and improved histopathological regeneration comparable to uninfected controls. Halo KS-7 have 58.716 kb linear dsDNA genome (44.4% G + C), contains 49 predicted ORFs, lacks integrase, lysogeny, or antibiotic-resistance genes, and includes three tRNA genes (tRNATyr, tRNAPro, and tRNAAsn). It also includes a toxin gene and auxiliary factors like MazG, pyrophosphatase, and HNH endonucleases that enhance bacterial killing without promoting horizontal gene transfer or resistance. Functional annotation assigned ~65% of ORFs to structural, replication, and packaging roles. Comparative genomics showed moderate similarity to other Myoviridae but with distinct accessory features, emphasizing its novelty and therapeutic value. Halo KS-7 is a novel, strictly lytic bacteriophage with strong antibacterial activity and stress resilience, supporting its use as a promising biocontrol agent against CRKP and its potential for clinical development in managing MDR infections.
Neurodegenerative diseases (NDDs) represent a growing global health burden, particularly in aging populations. These disorders primarily affect neurons and are characterized by progressive neuronal dysfunction and loss within specific regions of the central nervous system. Major NDDs include Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease, multiple sclerosis, and stroke. Although each disorder exhibits distinct genetic backgrounds and pathological protein aggregates, they share common pathogenic mechanisms, including chronic neuroinflammation, impaired autophagy and mitophagy, disrupted proteostasis, telomere instability, and epigenetic alterations. A hallmark feature across NDDs is the accumulation of misfolded proteins, leading to synaptic dysfunction and neuronal degeneration. Small ubiquitin-like modifiers (SUMOs) are a family of ∼100 amino acid proteins, including SUMO1 and the closely related SUMO2/3 isoforms. SUMOylation is a dynamic posttranslational modification that regulates protein function through the covalent attachment or removal of SUMO moieties. This reversible process is mediated by SUMO-specific E1 activating, E2 conjugating, and E3 ligating enzymes and is counterbalanced by SUMO/Sentrin-specific proteases. The SUMOylation status of target proteins depends on the tightly controlled balance between conjugation and deconjugation systems. Acting as a molecular switch, SUMOylation modulates diverse cellular processes such as DNA damage repair, RNA metabolism, transcriptional regulation, and protein quality control, all of which are essential for maintaining cellular homeostasis. Accumulating evidence links dysregulated SUMOylation to the pathogenesis of multiple neurological disorders, including polyglutamine and synucleinopathies. SUMOylation influences neuroinflammation, oxidative stress, protein aggregation, neuroangiogenesis, ischemic injury, and demyelination. This review highlights recent advances in understanding the role of SUMOylation in NDDs and explores its potential as a promising therapeutic target.
N6 -methyladenosine (m6A) is a major post-transcriptional RNA modification, and the demethylase ALKBH5 has emerged as a versatile but highly context-dependent regulator of RNA fate. This review integrates current evidence showing that ALKBH5 links epitranscriptomic control to cellular stress adaptation, genome maintenance, immune-cell function, viral infection, and therapeutic response. In DNA damage and cell-cycle regulation, ALKBH5 modulates checkpoint, repair, and apoptotic pathways, thereby influencing genome stability and sensitivity to radiotherapy or chemotherapy. In immune biology, it shapes γδ T-cell development, CD4+ T-cell pathogenicity, CD8+ T-cell infiltration, and tumor-immune crosstalk. In host-pathogen interactions, ALKBH5 can either enhance antiviral defense or promote viral persistence and latency, including HIV-1 reactivation, depending on the regulated transcript network. We propose that the biological output of ALKBH5 is determined by target transcript identity, cellular context, reader environment, and upstream regulatory signals. This framework positions ALKBH5 as both a mechanistic hub and a context-guided therapeutic target.
To describe both host gene expression and microbiome composition in a single sample, parallel experimental and computational workflows (mRNA-sequencing and either 16S rRNA gene or metagenomics) have been traditionally applied. The vulvar milieu represents an area of emerging research for its role in health and disease. Located at the interface between the vagina and the perineum, the vulvar microbiome displays an intermediate signature, with influx from both ecosystems. Following validation of the reliability of poly(A)-enriched mRNA-sequencing in reconstructing the microbiota composition using both a quantitative microbial standard (mock) and metagenomic analysis, we analyze a full cohort of 30 healthy vulvar samples. Crucially, the analysis of the entire cohort relies solely on mRNA-sequencing without the use of parallel DNA metagenomics. This unified approach allows us to analyze not only the vulvar cell transcriptome, but also the composition and dynamics of microbial communities, including the microbial gene expression signatures. This three-level analysis (host-mRNA, individual bacterial species, bacterial gene pathways) on the very same specimens further enables a gene-level exploration of host-microbe molecular crosstalk. Using this unified framework, we reveal marked heterogeneity and high inter-individual variability in the vulvar microbiota, identifying community state types that mirror those described in the vagina. Importantly, we show that distinct microbial configurations are associated with specific host transcriptional programs: Lactobacillus crispatus correlates with epithelial differentiation and barrier integrity, whereas communities enriched in Gardnerella vaginalis, or other taxa associated with dysbiosis, exhibit transcriptional signatures linked to inflammation. Interestingly, Lactobacillus gasseri, which has been associated with lower protection, shows an intermediate effect on vulvar cells. Beyond providing new biological insights into an understudied anatomical niche, our study introduces a broadly applicable strategy with substantial impact for the field. With tens of thousands of human RNA-seq datasets already available in public repositories, our approach enables retrospective extraction of microbiome information and host-microbe interaction signals from existing transcriptomic data, without the need for additional sequencing or specialized microbiome protocols. This unlocks a powerful and cost-effective opportunity to revisit archived RNA-seq studies across tissues, diseases, and low-biomass environments, revealing previously inaccessible layers of host-microbiome crosstalk and maximizing the scientific value of published data. Video Abstract.
Nicotinamide (NAM), the amide form of vitamin B3, has gained increasing attention in dermatology due to its potential role in both skin aging and non-melanoma skin cancer (NMSC) prevention. This review summarizes the biological rationale and current clinical evidence supporting the use of NAM and other NAD+ precursors in photoaging and cutaneous carcinogenesis. Chronic ultraviolet exposure induces DNA damage, oxidative stress, inflammation, immune dysregulation, and extracellular matrix remodeling, linking photoaged skin to increased susceptibility to actinic keratoses (AKs), squamous cell carcinoma (SCCs), and basal cell carcinoma (BCCs). Through the NAD+ salvage pathway, NAM contributes to the maintenance of intracellular NAD+ pools, thereby influencing energy metabolism, DNA repair, mitochondrial function, redox homeostasis, and the activity of NAD+-dependent enzymes. Preclinical studies indicate that NAM enhances DNA repair, reduces oxidative stress and inflammatory signaling, supports autophagy and mitophagy, and improves epidermal barrier function and extracellular matrix integrity. Clinically, the strongest evidence for anti-aging effects concerns topical NAM, which consistently improves wrinkles, texture irregularities, pigmentation, and barrier function. Oral NAM has demonstrated chemopreventive activity in high-risk patients with previous NMSC, particularly by reducing the incidence of new SCCs and AKs during active treatment. However, despite a strong mechanistic rationale, current evidence remains heterogeneous, and additional long-term, skin-focused clinical trials are needed to better define efficacy, safety, optimal dosing strategies, and patient selection.
Wet age-related macular degeneration is a leading cause of irreversible vision loss, primarily due to choroidal neovascularization (CNV) and subsequent fibrosis. Although current anti-vascular endothelial growth factor A (anti-VEGF) therapies offer significant benefits, many patients exhibit limited or no response and develop drug resistance over time, necessitating the exploration of complementary or alternative therapeutics. This study aimed to identify and characterize a platelet-derived growth factor-C (PDGF-C)-targeting DNA aptamer and to evaluate its therapeutic potential for suppressing CNV and fibrosis, including in an anti-VEGF-refractory setting. A DNA aptamer against PDGF-C (α-PC aptamer) was identified using systematic evolution of ligands by exponential enrichment. Its binding to PDGF-C and inhibition of PDGF-C/platelet-derived growth factor receptor alpha (PDGFRα) interaction were assessed using surface plasmon resonance. The effects of the α-PC aptamer on PDGF-C-induced proliferation, migration, and PDGFRα, Akt, and extracellular-regulated kinase (ERK) signaling were examined in fibroblasts and human umbilical vein smooth muscle cells (HUVSMCs). In vivo efficacy was evaluated in a laser-induced CNV mouse model, including anti-VEGF refractory aged mice. The α-PC aptamer specifically bound to PDGF-C and effectively blocked its binding to PDGFRα. The α-PC aptamer significantly inhibited PDGFRα, Akt, and ERK activation and suppressed PDGF-C-induced proliferation and migration of both fibroblasts and HUVSMCs. Importantly, in a laser-induced CNV mouse model, the α-PC aptamer markedly reduced neovascularization and fibrosis; it particularly retained efficacy in suppressing CNV in anti-VEGF refractory aged mice, where anti-VEGF treatment failed to do so. These findings suggest that the α-PC aptamer represents a promising therapeutic agent for treating neovascular diseases, especially in patients refractory to anti-VEGF treatment.
Staphylococcus aureus is a major cause of severe infections, including pneumonia and sepsis, partly due to its ability to survive within host cells where many antibiotics are ineffective. Drug repurposing offers a rapid strategy to identify compounds that enhance intracellular antibacterial activity by modulating host pathways. Here, a high-throughput screen of 6297 clinically approved compounds in S. aureus-infected A549 cells identified 5-fluoro-2'-deoxycytidine (5-FdC) as an effective intracellular inhibitor. When combined with rifapentine (5FR), 5-FdC displayed synergistic activity across community- and hospital-acquired MRSA and MSSA strains, as well as in different host cell types, including non-tumorigenic bronchial cells. Metabolomic and host RNA-sequencing analyses showed that 5-FdC treatment activated host stress-response and DNA damage response (DDR) pathways while restoring infection-induced metabolic imbalances, particularly in amino acid and central carbon metabolism. These transcriptional and metabolic changes correlated with reduced intracellular bacterial markers. In vivo, the 5FR combination significantly decreased bacterial loads in Galleria mellonella and murine pneumonia models without detectable toxicity. This study presents the largest repurposing screen performed against intracellular S. aureus and identifies a synergistic host- and pathogen-targeted combination that enhances bacterial clearance through coordinated modulation of host DDR, stress, and metabolic responses.
Immune checkpoint blockade has revolutionized oncology, yet low response rates and acquired resistance-often driven by inadequate Programmed death-ligand 1 (PD-L1) suppression-remain significant barriers. While degradation-based proteolysis-targeting chimeras offer a promising alternative to traditional antibodies, targeting the intracellular and transcriptional drivers of checkpoint expression remains a challenge. We report a programmable, tumor-responsive DNA hydrogel platform, synthesized via rolling circle amplification, designed for the comprehensive, dual-mode modulation of PD-L1. This modular nucleic acid framework codelivers polyvalent aptamer-based lysosome-targeting chimeras (LYTAC mimics) to induce extracellular PD-L1 degradation and siSMARCAL1 to silence the chromatin-remodeling-driven transcriptional activation of PD-L1. By integrating localized, sequential release within the tumor microenvironment, this system achieves a synergistic "degrade-and-silence" effect that effectively dismantles PD-1/PD-L1-mediated immunosuppression while concurrently triggering immunogenic cell death. In murine melanoma models, the hydrogel significantly suppressed primary tumor growth and prevented postoperative recurrence, eliciting a robust and durable systemic antitumor immune response. Our findings establish a versatile, DNA-based materials strategy for programmable protein degradation and multilevel checkpoint modulation, offering a generalizable approach for enhancing the efficacy of cancer immunotherapy.
Lysyl Oxidases (LOXs) catalyse elastin and collagen cross-linking in the extracellular matrix and have been implicated in cancer cell progression and metastases, particularly in breast cancer. In this study, we sought small-molecule inhibitors of LOXL2 using a library of 4-thiazolidones supported by molecular docking. Five candidates were prioritised, with Les 5740 displaying the highest LOXL2 inhibitory activity (IC50 of 27 μM). Although Les 5740 showed low cytotoxicity in various cancer and normal-like cell lines, the triple-negative breast cancer (TNBC) cell line MDA-MB-231 showed increased susceptibility to this molecule. Les 5740 did not induce DNA damage in mammary cells. At 30 μM, it increased TNBC cells' necrosis. The impact of a non-toxic concentration of Les 5740 (5 μM) on TNBC cell motility was evaluated. Les 5740 reduced 2D chemoinvasion and altered cell morphology. These findings are consistent with a potential reduction in extracellular matrix stiffness as a consequence of LOXL2 inhibition. Les 5740 mildly inhibited tubulin polymerisation, supporting a multi-target profile. Overall, Les 5740 should be viewed as a starting scaffold with LOXL2 inhibitory activity and broader cellular effects, motivating optimisation toward more potent and selective LOXL2 inhibitors for breast cancer therapy.
Human single-strand-selective monofunctional uracil DNA glycosylase 1 (hSMUG1) removes uracil, 5-hydroxymethyluracil (5hmU) and 5-fluorouracil (5FU) from DNA, thereby initiating the base excision repair (BER) process. hSMUG1 is important for maintaining genomic integrity and plays a significant role in cancer biology. Here, we present the structures of hSMUG1, including complexes with products (uracil and 5FU) and an enzyme-product complex of hSMUG1 with double-stranded DNA (dsDNA). Analysis of our hSMUG1-dsDNA complex reveals how uracil is flipped out of the dsDNA for excision and identifies key residues that we confirm to be critical for both DNA binding and enzymatic activity. Furthermore, our hSMUG1 substrate complexes, molecular dynamics simulations and neutron diffraction data suggest a mechanism by which the substrate uracil rotates following base excision. The structural and functional information presented here will be highly useful for the future development of inhibitors and/or activators targeting hSMUG1.
Pseudomonas promysalinigenes is a newly described bacterial species renowned for producing promysalin, a species-selective lipopeptide antibiotic. All previously reported strains of this species are derived from environmental niches such as plant rhizospheres, and no clinical infection cases associated with this bacterium have been documented to date. Thus, the clinical microbiology relevance, genomic features, and adaptive potential of P. promysalinigenes remain largely unexplored, and current reference databases have limited coverage of this rare species. A bacterial strain designated W2469 was isolated from the bile specimen of a patient with acute suppurative cholecystitis and cholecystolithiasis. Conventional phenotypic and molecular identification [matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), VITEK 2 biochemical assay, 16S ribosomal RNA (rRNA), and whole-genome sequencing (WGS)] was performed. Bioinformatics analyses, including average nucleotide identity (ANI), digital DNA-DNA hybridization (dDDH), core genome single-nucleotide polymorphism (cgSNP), pan-genome analysis, and functional annotation against COG, KEGG, CAZy, VFDB, and CARD databases, were conducted to characterize the strain. Conventional methods yielded consistent misidentification of the strain, while WGS definitively assigned it to P. promysalinigenes (ANI = 98.8%, dDDH = 91.1% against the type strain RW10S1). The strain exhibited a narrow-spectrum resistance phenotype, with resistance to aztreonam and ticarcillin/clavulanic acid, intermediate susceptibility to meropenem, and susceptibility to most clinically used antibiotics. Genomic annotation identified 25 antimicrobial resistance genes and 139 niche adaptation-related factors, most of which are low-identity homologs (<80%) of canonical reference sequences. Pan-genome analysis identified 571 clinical-specific genes associated with host adaptation, with complete loss of the environmental promysalin biosynthetic gene cluster. This study provides the first documentation of P. promysalinigenes as a clinical isolate from human bile, expanding the known ecological niche of this species to the clinical setting. Conventional methods are prone to misidentifying this rare species, and WGS is critical for accurate taxonomic identification. Importantly, the strain exhibits clear adaptive phenotypes despite low sequence identity to known functional elements, highlighting profound knowledge gaps in the genomic diversity and uncharacterized adaptive mechanisms of this rare Pseudomonas species. This work provides a foundational genomic resource for future investigations into this emerging opportunistic pathogen.
Lipid metabolism is abnormal in patients with atopic dermatitis (AD). This study aimed to screen lipid metabolism-related gene (LMRG) in AD, providing insights into the underlying mechanisms of lipid metabolism abnormalities in AD. Gene expression profiles from the Gene Expression Omnibus were analyzed to identify a hub LMRG in AD through an integrative approach combining weighted gene co-expression network analysis, differential expression analysis, and machine learning. The diagnostic value of the hub gene was assessed by receiver operating characteristic curve analysis. Its biological functions and associations with immune cells were investigated using Gene Set Enrichment Analysis (GSEA)/GSVA and ssGSEA/correlation analysis, respectively. The expression of ganglioside GM2 activator (GM2A) in clinical samples was measured using reverse transcription quantitative polymerase chain reaction and an ELISA assay. We identified 14 LMRGs that were differentially expressed between AD and normal samples and were correlated with AD onset. By three machine learning algorithms, GM2A was identified as a robust LMRG in AD. GM2A expression was observed to be elevated in AD samples across transcriptomic analyses and clinical validation. Moreover, GM2A might be effective in distinguishing between individuals with AD and those without. We further discovered that GM2A was associated with immunomodulation, inflammatory response, and biosynthesis of unsaturated fatty acid pathways. GM2A expression was positively correlated with follicular helper T cells, Activated CD4+ T cells, and natural killer T cells. Besides, there was a significant relationship between GM2A and multiple drugs. This study highlighted the significant up-regulation of GM2A as an efficient biomarker for AD, linking it to immune and inflammatory responses as well as immune cell infiltration.
DNA topoisomerase 1 (Top1) is essential for resolving DNA supercoiling during replication and transcription. Here, we identify protein arginine methyltransferase 5 (PRMT5) as a novel regulator of human Top1 activity via symmetric dimethylation at arginine residues R708 and R749, located in the linker and catalytic domains, respectively. Methylation enhances Top1-mediated strand rotation and DNA relaxation without affecting its DNA binding ability. In contrast, methylation-deficient Top1 mutants (Top1KK) display impaired subnuclear mobility and accumulate elevated levels of trapped Top1-DNA covalent complexes (Top1cc) upon camptothecin (CPT) treatment. These defects are independent of PRMT5-Top1 binding but are dependent on PRMT5's enzymatic activity. Loss of Top1 methylation-via point mutation, PRMT5 knockout, or pharmacological inhibition-delays Top1cc resolution and amplifies CPT-induced DNA damage. Strikingly, combining PRMT5 inhibitors (PRMT5i) with Top1 poisons such as irinotecan enhances cytotoxicity across multiple cancer cell types. In a triple-negative breast cancer mouse model, this combination significantly suppresses tumor growth and metastasis, accompanied by increased DNA damage. Our results define PRMT5-driven Top1 arginine methylation as a crucial regulatory mechanism and highlight PRMT5i as a means to potentiate Top1-based cancer treatment.
Sulfur mustard (SM), a hazardous chemical warfare agent, poses severe threats to environmental safety and public health due to its persistent toxicity. While the blistering effects of SM are well documented, its impact on the immune system has aroused increasing concern recently. However, the molecular basis underpinning the immune dysregulation elicited by SM remains elusive. Here we found that systemic SM exposure suppressed regulatory T (Treg) cell differentiation, leading to multiple organ inflammation in mice. Both pharmacological inhibition and genetic disruption of DNA methyltransferase Dnmt3b rescued Treg induction and alleviated inflammatory injury in SM-exposed mice, identifying Dnmt3b as a central mediator of SM immunotoxicity. Exposure to SM markedly increased DNA methylation of Foxp3 by upregulating Dnmt3b and enhancing its binding to the Foxp3 promoter. Notably, oleic acid (OA) accumulated upon SM challenge and acted as a signaling molecule to modulate Treg differentiation in a Dnmt3b-dependent manner. Our work reveals that SM disrupts Treg differentiation by altering OA abundance to promote Dnmt3b-mediated DNA methylation, highlighting Dnmt3b as a compelling therapeutic target and identifying Foxp3 promoter methylation and OA as promising biomarkers for SM immunotoxicity assessment.
Checkpoint kinase 1 (CHK1), a key regulator of cell cycle checkpoints, plays a central role in the DNA damage response network, serving as a critical mediator that links DNA damage detection to DNA repair mechanisms. In recent years, several other cellular functions of CHK1 have gradually been discovered. As well as monitoring genomic integrity, CHK1 coordinates the timing of DNA replication with the availability of metabolic resources. This prevents unscheduled DNA synthesis from exceeding the cell's metabolic capacity and causing DNA damage. CHK1 activity also contributes to tumour immune surveillance and the modulation of immune cell infiltration and immune escape mechanisms within the tumour microenvironment. Furthermore, CHK1 is involved in the regulation of differentiation and epigenetics. This perspective on CHK1 provides a strategy foundation for next-generation combinatorial therapies. Indeed, the data presented herein underscores the potential of novel therapeutic strategies that target diverse aspects of tumour biology in a simultaneous manner. Despite the current lack of clinically approved CHK1 inhibitors, the pleiotropic roles of this kinase make it an attractive and promising target for new cancer therapies. The present review aims to analyze the structural and functional aspects of CHK1, with a particular focus on its "non-canonical" functions.
A Gram-stain positive, aerobic, rod-shaped bacterium, designated BYT-33-1T, was isolated from a typical sandy soil in Xinjiang, PR China. This isolate grew well at 20-40 °C, pH 6.0-10.0 and 0-3.0% (w/v) NaCl, with optimal growth at 30 °C, pH 7.0 and 0.5% NaCl, respectively. Phylogenetic analysis of 16S rRNA gene sequences indicated that BYT-33-1T shared the highest sequence similarities with Nocardioides nitrophenolicus NSP 41T (98.4%) and Nocardioides kongjuensis A2-4T (98.3%). The draft genome was 5,327,936 bp, consisting of 24 contigs, with a G+C content of 72.4 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between strain BYT-33-1T and its closely related type strains of genus Nocardioides were 88.1-80.5% and 35.0-23.5%, respectively. The predominant menaquinone was MK-8(H4), and C18:0 10-methyl and iso-C16:0 constituted the major cellular fatty acids. The major polar lipids were diphosphatidylglycerol and phosphatidylglycerol, one unidentified aminolipid (AL) and three unidentified phospholipids. The ll-diaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan. In addition, strain BYT-33-1T exhibits hexadecane degradation ability, suggesting its potential application value in alkane bioremediation of contaminated environments. Based on chemotaxonomic, phylogenetic, phenotypic and genomic analyses, we propose a novel species, named Nocardioides segetis sp. nov., with the type strain BYT-33-1T (=CCTCC AA 2024001T=KCTC 59242T).