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Wu, K.

Publications and source records attributed to Wu, K..

At least 19 recordsLinked to original sources

Characterization of the Preclinical in Vitro and in Vivo Pharmacokinetic Properties of the Cyclic Oligomeric Depsipeptide Ryanodine Receptor 2 Inhibitor ent-Verticilide

ent-Verticilide is a synthetic cyclic oligomeric depsipeptide that inhibits ryanodine receptor 2 (RyR2)-mediated calcium (Ca) leak and has demonstrated antiarrhythmic activity in mice. This study characterized the preclinical absorption, distribution, metabolism, and pharmacokinetic properties of ent-verticilide and investigated factors affecting its oral exposure. ent-Verticilide was stable in rat plasma and simulated gastric and intestinal fluids but exhibited extensive plasma protein binding (>94%) and low apparent permeability in Caco-2 cells, with no evidence of pronounced net efflux. In rat and human liver microsomes, ent-verticilide underwent rapid NADPH-dependent metabolism, with an in vitro half-life of 5.43 min and 4.35 min, respectively, and a predicted hepatic extraction ratio of 0.90 and 0.92, respectively. Following intravenous administration in rats, ent-verticilide exhibited a systemic clearance of 25.5 mL/min/kg and a large steady-state volume of distribution (4.72 L/kg). Absolute oral bioavailability was approximately 16%. Simultaneous portal and systemic sampling estimated intestinal availability (FaFg) at 0.25 and hepatic availability (Fh) at 0.64, suggesting that processes occurring before hepatic entry are a major limitation to oral exposure. Pretreatment with the CYP inhibitor 1-aminobenzotriazole increased portal and systemic exposure approximately 10.6- and 18.5-fold, respectively, and increased apparent Fh to approximately 1. Collectively, these findings identify limited intestinal availability and CYP-mediated presystemic metabolism as important determinants of ent-verticilide exposure and provide a framework for its continued development as an RyR2-targeted therapeutic.

pharmacology and toxicology↗

Design of readers for pathological PTM proteoforms in Alzheimer's disease

Alzheimer's disease (AD) is characterized by heterogeneous Tau phosphorylation and aberrant amyloid-beta (Abeta) processing, yet molecular tools that distinguish closely related molecular states of tau and Abeta with predefined specificity remain difficult to develop. Here, we designed de novo protein readers targeting three disease-associated phospho-Tau regions and N-terminal pyroglutamate-modified Abeta (N3pG-Abeta). Screening 192 designs per target identified 51 modification-selective hits among 768 candidates (6.6%). Representative readers exhibited nanomolar to subnanomolar affinities for modified peptides, discriminated authentic modifications from unmodified or substitution-based controls, and preferentially recognized modified full-length targets. We further programmed local modification specificity by interface redesign, generating pT231 readers conditional on the phosphorylation state of neighboring S235 and S237. A 2.0-angstrom crystal structure of an N3pG-Abeta reader closely matched the computational design model (interface C-alpha RMSD = 0.52 angstrom), and redesign of pT231 readers tuned apparent binding affinities from greater than 1 uM to below 1 nM. In a human 3D neuronal culture with both pathological Abeta and tau, selective readers targeting N3pG-Abeta, Tau pT231, and Tau pT217 recognized disease-associated signals, exhibiting colocalization with related antibodies and much higher signal in the AD line than the control. Tau pT231 readers further quantitatively distinguish AD patients and control human brain lysates in dot-blot assays. Together, these results establish genetically encoded readers with programmable specificity for defined Tau and Abeta modification states, enabling molecular-state-resolved detection in human disease models and biological samples, and lay a foundation for controlled pathological molecular perturbation.

bioengineering↗

Design of synthetic activators for programmable gene expression

Transcription factors control gene expression by recruiting transcriptional coactivators through intrinsically disordered transcriptional activation domains (TADs), whose weak and promiscuous interactions make it difficult to establish quantitative relationships between coactivator recruitment and transcriptional output, and to precisely modulate gene expression. To overcome this limitation, we set out to design coactivator-recruiting proteins using AlphaFold3-predicted TAD-coactivator interactions as a guide. We developed a high-throughput functional screening platform in mammalian cells and identified over 300 well folded nanomolar affinity binders to the transcription coactivators Mediator (multiple subunits), BRD4, NCOA, and p300; targeted interface mutations enabled systematic tuning of their binding affinities. Using a panel of p300 binders spanning nanomolar to micromolar affinities, we found an ultrasensitive relationship between coactivator-binding affinity and transcriptional output, with a sharp transcriptional activation threshold at ~500 nM. Incorporating p300 binder designs into CRISPRa yielded compact synthetic effectors that drove stronger activation than VPR across multiple genomic loci with minimal detectable cytotoxicity. Combining p300- and Mediator-specific binders further enhanced transcription, revealing functional synergy between these coactivators. Together, our work establishes a quantitative framework linking coactivator-binding affinity to transcriptional output and provides compact synthetic effectors for programmable gene activation.

synthetic biology↗

MYC targeted de novo binders impair tumor growth

MYC is one of the most frequently dysregulated oncogenic drivers across many cancers, yet direct therapeutic targeting has remained difficult because its function is mediated by disordered regions and transient protein-protein interactions. Here we design proteins that bind epitopes within regions of MYC whose sequence is conserved between human and mouse, including intrinsically disordered motifs required for oncogenic activity. In vitro, the designs bind MYC with nanomolar affinity and in cells they engage MYC, disrupt interactions with MAX, and remodel MYC-associated protein complexes. Expression of the binders decreases cell proliferation across diverse MYC-dependent hematopoietic, liver, pancreatic, and patient-derived tumor models, and in an orthotopic pancreatic cancer model, binder-expressing tumor cells were selectively depleted. This work establishes de novo protein design as a generalizable strategy to therapeutically target intrinsically disordered transcription factors.

biochemistry↗

Splicing-guaranteed artificial introns enable efficient homology-directed repair at internal exons and streamlined cell engineering

Selection-marker-assisted homology-directed repair (HDR) efficiently edits coding sequence termini but is poorly suited for internal exons. Here, we developed artificial reporter intron-based HDR (ARI-HDR), which inserts a selectable intron into target exons to enable precise internal-exon editing. Although designed for scarless removal by splicing, ARIs frequently exhibit inaccurate splicing. Using a random mutagenesis reporter assay, we identified intron upstream sequences (IUS) as key determinants of splicing fidelity and screened degenerate IUS variants to obtain reliably spliced ARI donors. ARI-HDR successfully introduced site-specific mutations into five human genes. Combining long single-stranded DNA donors with conversion-tract optimization increased editing efficiency to over 80%. This efficiency enabled 'Dirty-Editing,' a streamlined workflow that generates precisely edited mixed-cell populations without single-cell cloning. Together, ARI-HDR extends selection-based enrichment to internal exons across protein-coding genes, while our splicing-optimized intron design offers a broadly applicable solution for artificial intron-based technologies.

molecular biology↗

Multimodal Magnetic Resonance Imaging Biomarkers of Pediatric Traumatic Brain Injury Identified by Ensemble Learning Are Associated with Psychopathology

Background: Pediatric traumatic brain injury (TBI) is associated with increased psychopathology, but the neural alterations underlying this vulnerability remain poorly understood. We used interpretable machine learning to identify multimodal MRI features associated with pediatric TBI and their relationship with psychopathology. Methods: Baseline multimodal MRI data from 775 children aged 9-10 years in the Adolescent Brain Cognitive Development Study were analyzed, including 365 children with TBI and 410 controls. Structural MRI, diffusion MRI, and resting-state functional MRI features were evaluated using nested cross-validated ensemble classification. Permutation-based feature importance identified discriminative features, which were subsequently examined using partial least squares (PLS) regression in the TBI and control groups. Results: Classification performance was above chance across models, with accuracy ranging from 0.612-0.665 and AUC from 0.644-0.714, and was comparable in an independent validation sample. Twenty neuroimaging features spanning all three modalities were reliably discriminative, including measures of white matter microstructure, gray matter volume, regional functional variability, and functional connectivity. In the TBI group, a significant PLS component was associated with overall psychopathology scores (r = 0.22, permuted p = 0.008), whereas no significant component was identified in controls. Ten discriminative features contributed substantially to this association. Conclusions: Pediatric TBI is characterized by a distributed multimodal neuroimaging signature specifically associated with psychopathology following injury. Interpretable machine learning combined with multivariate brain-behavior modelling may help identify neural substrates of psychiatric vulnerability after pediatric TBI.

neuroscience↗

Structure-Constrained Intrinsic Timescales Across Tasks

Intrinsic neural timescale (INT) quantifies the persistence of spontaneous neural dynamics and offers a principled metric for characterizing brain-wide temporal organization. Although a hierarchy of INTs has been established during rest, how task engagement reconfigures this organization and how it is constrained by the structural connectome (SC) remain poorly understood. Here, we systematically mapped whole-brain INT using high-resolution fMRI data from the Human Connectome Project during rest and seven tasks spanning working memory, gambling, motor, language, social, relational, and emotion domains. Task engagement induced robust, regionally heterogeneous changes in INT while largely preserving the brain-wide temporal hierarchy across cognitive states. SC-INT coupling remained strong but consistently decreased during tasks, indicating that anatomical architecture continues to constrain INT, although its influence is attenuated under task demands. To investigate these findings mechanistically, we employed a multiscale, whole-brain neuronal-network model, which revealed that INT increase and peak within a broad critical-like regime. Strong SC-INT coupling, as observed empirically, emerged in the subcritical regime, weakened progressively with increasing network excitability, and reversed in the supercritical regime. These results demonstrate that task engagement reconfigures INTs while maintaining their hierarchical organization, suggesting that both resting and task states operate largely within a common subcritical dynamical regime.

neuroscience↗

Visual and Instrumental Assessment of Interaction of UVC Radiation with Liposomes in FeCl3 Solutions

Previously, we have demonstrated that certain ferric salts common in Archean waters, such as iron trichloride and ferric ammonium citrate, can protect liposomes from destruction by short-wavelength UVC light. In this study, we investigate the propagation of 254 nm UV radiation through aqueous FeCl3 solutions and its interactions with liposomes. We then consider these findings in the context of early Earth UV environment, discuss their implications for our hypothesis of the Darwinian evolution of liposomes, and integrate them with our previous experimental results.

evolutionary biology↗

Diagnostic Performance of Fluorescence-Based Rapid On-Site Specimen Evaluation for Helicobacter pylori Antimicrobial Susceptibility Testing Before and After Algorithm Optimization: A Two-Round Comparative Study

ObjectiveThis study was designed to evaluate the diagnostic performance of fluorescence-based rapid on-site specimen evaluation (F-ROSE) for antimicrobial susceptibility testing of Helicobacter pylori (H. pylori) and to compare test performance before and after iterative optimization of fluorescence image acquisition and of the artificial intelligence (AI) recognition algorithm, using two consecutive rounds of paired testing, so as to provide trial data supporting clinical implementation of rapid susceptibility testing. MethodsForty patients with a urea breath test (UBT) or rapid urease test (RUT) positive for H. pylori within the preceding 2 weeks, together with strongly positive endoscopic findings, were prospectively enrolled. In order of enrollment they were allocated to two rounds in which F-ROSE was compared with culture-based susceptibility testing. Twenty patients were tested in round 1 on an automated fluorescence immunoassay scanner running the original algorithm; a further 20 were tested in round 2 with the optimized algorithm. With in vitro culture and E-test as the reference standard, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of F-ROSE were calculated for each round for amoxicillin, levofloxacin hydrochloride and clarithromycin, and agreement between methods was assessed with Cohens kappa. Receiver operating characteristic (ROC) analysis was used to identify the optimal cutoff of the fluorescence residual rate (FRR) and to determine how far threshold adjustment improved performance. ResultsCulture succeeded in 15 patients in round 1 and in 14 patients in round 2, leaving 29 evaluable samples. Overall diagnostic performance after algorithm optimization was clearly better than before. Pooled across the three antibiotics, sensitivity was 92.9%, specificity 71.0% and accuracy 77.8% before optimization; after optimization sensitivity rose to 100.0%, specificity increased slightly to 74.2% and accuracy to 81.0%. NPV reached 100.0% for all three agents after optimization, and no resistant isolate was missed. The gain was largest for clarithromycin, for which sensitivity rose from 85.7% to 100.0%, accuracy from 66.7% to 78.6% and kappa from 0.348 to 0.571, indicating a clear improvement in agreement between the two methods. ROC analysis showed that drug-specific optimal cutoffs derived from the Youden index improved specificity appreciably compared with the uniform 50% FRR threshold currently applied, the gain being most evident for levofloxacin hydrochloride. ConclusionsWith sharper fluorescence images and an improved AI recognition algorithm, F-ROSE performs better in H. pylori susceptibility testing, and the reduction in missed resistant strains is particularly noteworthy; the assay is therefore a plausible option for rapid susceptibility screening in clinical practice. Multicenter studies with larger samples are still required to confirm the stability of the technique.

microbiology↗

Mapping Functional Tumor Suppressor Networks in Esophageal Adenocarcinoma Using In Vivo CRISPR Screening and Perturb-sequencing

Esophageal adenocarcinoma (EAC) is a genetically heterogeneous malignancy with few recurrent drivers, limiting effective targeted therapies. Although EAC arises from Barretts esophagus (BE), mechanisms driving progression from this premalignant state to invasive cancer remain unclear. We combined pooled CRISPR-Cas9 loss-of-function screening, in vivo tumorigenicity assays, and Perturb-seq profiling to define functional drivers of BE transformation. We identified 37 tumor suppressors whose loss promotes progression to EAC, defining a functional landscape of tumor initiation. Despite genetic diversity, these losses converged on four transcriptional programs involving metabolic reprogramming, cell cycle progression, RNA processing, and cellular motility. Furthermore, we identify loss of NIPBL, TGFBR2, and RPL22 as key mediators of resistance to platinum- and taxane-based chemotherapy. Collectively, these findings provide a unifying framework for genomic heterogeneity in EAC, uncover underappreciated tumor suppressor pathways, and establish a resource to guide mechanistic and translational studies aimed at improving treatment strategies in this aggressive cancer.

cancer biology↗

Optogenetic decoupling of ODC inhibition and degradation reveals a requirement of polyamine oscillation for cell cycle progression

The dysregulation of polyamine homeostasis is a fundamental hallmark of both cancer and aging. Ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine synthesis, is regulated by the antizyme OAZ1 through a dual mechanism: inhibition of enzymatic activity and induction of proteasomal degradation via a C-terminal degron. In Bachmann-Bupp syndrome (BABS), mutations in this degron lead to ODC accumulation and toxic polyamine levels. However, the functional coupling between ODC inhibition and degradation remains poorly understood, and the current therapeutic intervention with DFMO target enzymatic activity without addressing protein accumulation. Here, we developed an optogenetic yeast model of BABS to decouple ODC inhibition from its degradation. By fusing a light-switchable LOV2-based module to a truncated, degron-less yeast ODC, we created a system where ODC degradation is controlled by light, independent of OAZ1 binding. We demonstrate that the loss of the ODC degron mimics the BABS cellular phenotype, characterized by increased polyamines, elevated ROS, and growth arrest. Crucially, while constant light-induced degradation is insufficient to rescue growth, oscillating ODC degradation at a 40-minute period restores polyamine homeostasis, cell cycle progression, and cellular growth. Our findings demonstrate that the inhibitory and degradation-inducing roles of OAZ1 can be decoupled and highlight the necessity of periodic polyamine oscillation for the cell cycle. Our work would be of great value for understanding the regulation mechanism of the polyamine metabolic network and establishing new targeted therapeutic strategies. Significance statementMutations in ODC degron lead to ODC accumulation and toxic polyamine levels in BABS. While DFMO has provided clinical relief for BABS patients, its utility is limited because it only inhibit ODC activity. We utilized an optogenetic approach in Saccharomyces cerevisiae to bridge this knowledge gap. We successfully decoupled the inhibitory and degradation-inducing functions of the ODC-OAZ1 axis and achieved three significant biological insights. First, we established yeast as a powerful and versatile model for investigating of the molecular mechanisms of BABS. Second, we demonstrated that the inhibitory and degradation-inducing roles of OAZ1 can be decoupled under specific conditions. Third, we revealed that periodic oscillation in polyamine levels is essential for maintaining proper cell cycle progressing.

molecular biology↗

A novel AR molecular glue degrader via bivalent engagement of the N-terminal domain and RNF213-UBE2J2 complex

Targeted protein degradation enables the elimination of disease-relevant proteins through induced proximity between E3 ligases and substrates. Current androgen receptor (AR) therapies act via the ligand-binding domain (LBD) but fail against constitutively active LBD mutants or splice variants such as AR-V7. Here, we identify GZL626, a small-molecule degrader that induces proteasome-dependent degradation of both full-length AR and AR-V7. GZL626 suppresses AR transcriptional activity, inhibits proliferation of AR-positive prostate cancer cells, and blocks SARS-CoV-2 infection. Mechanistically, GZL626 binds the intrinsically disordered AR N-terminal domain (NTD) and promotes formation of a noncanonical RNF213-UBE2J2-AR ternary complex that drives AR ubiquitination and degradation. The AR DNA-binding domain (DBD) acts as a structural hub within this assembly. Distinct from PROTACs or classical molecular glues, GZL626 engages both AR and RNF213 bivalently, remodeling protein interactions to stabilize a functional E3-E2-substrate complex. These findings establish GZL626 as a first-in-class NTD degrader with potential to overcome resistance in advanced prostate cancer.

biophysics↗

Oral Gut Microbial Axis in Inflammatory Bowel Disease and Primary Sclerosing Cholangitis

The oral cavity is increasingly recognized as a reservoir of microbes that can translocate to and influence the gut microbiome. This oral-gut microbial axis may contribute to the pathogenesis of chronic gastrointestinal and hepatobiliary disorders, including inflammatory bowel disease (IBD) and its comorbidity, primary sclerosing cholangitis (PSC). To investigate the oral-gut microbial axis in IBD and PSC, we enrolled 191 participants spanning Crohns disease (CD), ulcerative colitis (UC), CD with PSC (CD-PSC), UC with PSC (UC-PSC), and healthy controls. We generated and analyzed the whole-metagenome shotgun sequencing data from saliva, tongue swabs, and fecal samples. Across oral and gut niches, we identified multiple microbial species differentially enriched in participants with UC compared with healthy controls, including Fusobacterium nucleatum and Gemella sanguinis in saliva, Catonella massiliensis and Tannerella serpentiformis on the tongue, and G. sanguinis and Sellimonas intestinalis in feces. Paired oral-gut analyses revealed 15 potential oral-origin species enriched in fecal samples; notably, G. sanguinis and Veillonella rogosae were consistently enriched in participants with UC. These findings were further supported by an external validation dataset comprising 1,716 gut metagenomes from five independent IBD cohorts, highlighting the reproducibility of oral microbial signatures. In exploratory analyses, smoking history was associated with shifts in the oral microbiome toward a UC-like state in healthy controls, suggesting a possible environmental modifier of the oral-gut microbial axis. Collectively, our study identifies distinct oral microbial signatures and their potential translocation to the gut in IBD and PSC, underscoring the role of the oral- gut microbial axis in disease progression.

microbiology↗

The novel HP1a interactor Clump/CG30403 safeguards transposon silencing and reproductive resilience in the Drosophila ovary

Heterochromatin and its core effectors from the Heterochromatin Protein 1 (HP1) family are essential for epigenetic silencing of repetitive regions and genome integrity from yeast to humans. However, how HP1s and associated factors regulate heterochromatin properties in vivo to sustain silencing across development, aging, and environmental factors, remains incompletely understood. Here, we identify Clump/CG30403 -- a previously uncharacterized MADF-BESS domain protein -- as a novel heterochromatin factor required for robust transposon silencing during Drosophila oogenesis and sustained fertility with age and temperature stress. Clump/CG30403 interacts with the main HP1-family silencing effector Su(var)205/HP1a through a noncanonical binding motif within its large intrinsically disordered region. Notably, in the absence of Clump/CG30403, HP1a mobility and silencing capacity are compromised despite largely unperturbed genomic distribution, showing that HP1a presence alone is insufficient for repression. We also show that Clump/CG30403 uniquely accumulates at its own promoter to self-repress and prevent ectopic aggregation, revealing a feedback mechanism to constrain protein dosage and phase behavior. Overall, we propose that Clump/CG30403 is a HP1 corepressor that acts as a tightly calibrated safeguard of the heterochromatin environment properties to ensure stable silencing, genome integrity, and persistent reproductive function.

molecular biology↗

Chronic Polystyrene Nanoplastics Exposure Reprograms Gene Expression, Alternative Splicing, and Disrupts Host Microbiome Metabolic Networks to Promote Atherosclerosis in LDLr- Knockout Mice

Although micro- and nanoplastics have been detected in human atherosclerotic plaques, their mechanistic contribution to disease pathogenesis remains poorly defined. Most experimental studies have used microplastics (particles > 1 m) in non-atherosclerotic animal models or the ApoE-/- mouse, relying on short-term exposure or single-pathway analyses, whereas the chronic cardiovascular effects of nanoplastics (< 100 nm) remain exceedingly scarce--despite their higher biological reactivity and greater tissue penetrance. To address this gap, this study employs a multi-omics approach to investigate the chronic (12-week) oral exposure to 80 nm polystyrene nanoplastics in LDLr-/- mice. We uniquely integrate aortic plaque quantification, hepatic transcriptomics with global alternative splicing profiling, gut microbiome 16S sequencing, and liver untargeted metabolomics to construct a unified host-microbiome-metabolite network. Nanoplastic exposure significantly exacerbates aortic lipid deposition, suppresses hepatic detoxification and anti-atherogenic lipid pathways primarily through transcriptional and post-transcriptional level changes driven by alternative splicing events (e.g., intron retention and isoform switching), and induces gut dysbiosis marked by a reduction in SCFA-producing commensals and enrichment of pro-atherogenic pathobionts--perturbations that correlate with specific hepatic functional modules. Metabolomic changes, including decreased levels of the glutathione precursor {gamma}-glutamylcysteine and the choline-derived metabolite neurine, implicate oxidative stress and TMAO-related pathways. Cross-species validation using human atherosclerotic transcriptomic and metagenomic datasets supports the clinical translatability. By integrating multi-level biological responses, this work establishes nanoplastics as an environmental cardiovascular risk factor and uncovers novel regulatory mechanisms involving splicing-associated transcriptional reprogramming and gut-liver crosstalk, offering potential early-warning biomarkers and therapeutic targets for nanoplastic-associated cardiovascular disease. HighlightsO_LIExposure to polystyrene nanoplastics (80 nm) increases aortic lipid burden in LDLr-/- mice. C_LIO_LIAlternative splicing and isoform switching were identified as novel hepatic responses. C_LIO_LISCFA-producing gut commensals are depleted, and pathobionts are enriched in response to nanoplastics. C_LIO_LIA gut-liver network links suppressed detoxification to gut microbial dysbiosis. C_LIO_LIMouse transcriptomics and metagenomics overlap with human atherosclerosis omics datasets. C_LI O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=142 SRC="FIGDIR/small/736446v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@196ad0eorg.highwire.dtl.DTLVardef@13b95d3org.highwire.dtl.DTLVardef@e963c4org.highwire.dtl.DTLVardef@94f60c_HPS_FORMAT_FIGEXP M_FIG Graphical Abstract C_FIG

molecular biology↗

Polystyrene microplastics uptake drives Inflammatory, Epitranscriptomic, and Metabolic Reprogramming in Human aortic endothelial cells

Microplastics (MPLs) are pervasive environmental pollutants increasingly linked to adverse human health outcomes, including atherosclerosis. However, the underlying mechanisms remain poorly understood. Human aortic endothelial cells (HAECs), which line the inner surface of blood vessels, play a critical role in maintaining vascular homeostasis and in the development of atherosclerosis. This study demonstrates that polystyrene microplastics enter HAECs through clathrin-mediated endocytosis and macropinocytosis and subsequently co-localize with mitochondria and lysosomes. Exposure to MPLs induced coordinated transcriptional, epitranscriptomic, and metabolomic reprogramming in HAECs. Transcriptomic analysis revealed disruption of mitochondrial genes and activation of inflammatory pathways with the response of the NF-{kappa}B pathway being particularly prominent. Mass spectrometry analysis of RNA modification further identified significant remodeling of the epitranscriptomic landscape, highlighted by increased 1-methyladenosine (m1A) modification and reciprocal regulation of its associated enzymes (TRMT61A upregulation and ALKBH3 suppression), along with alterations in other RNA modifications such as m3C, pseudouridine ({Psi}), m5C, and m7G. Comparative analysis of transcriptomic profiles from human atherosclerotic plaques revealed shared dysregulated pathways in vascular regulation and cellular signaling. Metabolomic profiling further showed extensive remodeling of lipid metabolic networks associated with oxidative stress and inflammation. Together, these findings suggest that MPLs exposure may disrupt endothelial function and pose a potential risk to human cardiovascular health. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=141 SRC="FIGDIR/small/737624v2_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@2ad601org.highwire.dtl.DTLVardef@47f041org.highwire.dtl.DTLVardef@ee45cdorg.highwire.dtl.DTLVardef@128d6d5_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

Integrin-engaged Cellular Patches Mechanically Impose a Mitochondrial Respiratory Bottleneck to Suppress Cancer Cell Motility

The nanoscale organization of cell-adhesive ligands is increasingly recognized as a determinant of cell behavior, yet whether it directly regulates cellular metabolism remains unclear. Here we show that supramolecular clustering of integrin-binding ligands regulates mitochondrial respiratory capacity through integrin-mediated mechanotransduction. Supramolecular ligand clustering induces integrin redistribution and cytoskeletal remodeling, leading to mitochondrial reorganization and a selective constraint on oxidative phosphorylation. This respiratory limitation functionally constrains tumor cell migration and invasion and cannot be overcome by restoring cytoskeletal contractility, whereas replenishing mitochondrial metabolic substrates effectively rescues motility. In a HeLa xenograft model, the integrin-binding supramolecular system suppresses tumor growth and reduces extracellular matrix deposition. These findings identify mitochondrial respiratory capacity as a critical downstream effector of integrin mechanosignaling and establish extracellular ligand organization as a previously unrecognized driver of mechanically encoded metabolic regulation.

biophysics↗

Culture-Free Rapid Phenotypic Antimicrobial Susceptibility Testing for Helicobacter pylori Based on Fluorescence Rapid On-Site Evaluation Technology: A Preliminary Study

BackgroundPhenotypic antibiotic susceptibility testing (AST) for Helicobacter pylori (H. pylori) has relied on bacterial culture for three decades, requiring 5-7 days to yield results. Genotypic rapid tests can only detect known resistance mutations and fail to reliably identify amoxicillin resistance. To our knowledge, no culture-free rapid phenotypic AST method for H. pylori has been previously reported. MethodsWe developed a phenotypic AST method based on fluorescence rapid on-site evaluation (ROSE) technology that completely bypasses bacterial culture. Gastric mucosal biopsy specimens from 40 H. pylori-positive patients were homogenized and co-incubated with an acridine orange/ethidium bromide (AO/EB)-based viability staining reagent and three first-line antibiotics--amoxicillin, clarithromycin, and levofloxacin--at concentrations corresponding to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints for H. pylori, at 37 {degrees}C for 1 hour. Fluorescence intensity was measured using a microplate reader. A reduction in fluorescence relative to an antibiotic-free control indicated susceptibility, whereas no significant reduction indicated resistance. Conventional culture-based AST (E-test) served as the reference method. The overall concordance rate, sensitivity, specificity, and Cohens kappa coefficient were calculated. ResultsFourteen of the 40 samples had unsuccessful culture and were excluded, leaving 26 samples for statistical analysis of each antibiotic. The overall concordance rates between the ROSE method and culture-based AST were 84.6% (22/26) for amoxicillin, 76.9% (20/26) for levofloxacin, and 69.2% (18/26) for clarithromycin. Cohens kappa coefficients indicated moderate agreement for all three antibiotics ({kappa} = 0.523, 0.539, and 0.412, respectively). Unlike genotypic methods, the ROSE method successfully assessed amoxicillin susceptibility in all 40 patients--a critical first-line antibiotic for which no reliable genetic resistance marker currently exists. The turnaround time was approximately 1 hour (55-65 minutes), compared with 5-7 days for culture-based methods; preliminary estimates indicated a cost reduction of approximately 3,000-5,000 Chinese yuan (CNY) per patient, mainly attributable to the elimination of culture media, prolonged incubation, and repeat clinic visits. ConclusionsThis study reports, for the first time, a culture-free 1-hour phenotypic AST for H. pylori. The method enables same-day, susceptibility-guided treatment decisions, addressing an unmet clinical need spanning three decades. Algorithm optimization and a prospective randomized controlled trial are currently underway to further improve diagnostic accuracy and validate clinical utility.

microbiology↗