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Xu, W.

Publications and source records attributed to Xu, W..

At least 37 records · Page 2Linked to original sources

Ribonucleotide Reductase Inhibition Overcomes FLT3 Inhibitor Resistance in Acute Myeloid Leukemia

Internal tandem duplication mutations in FLT3 (FLT3ITD) occur in approximately 30% of patients with acute myeloid leukemia (AML) and are among the most common genetic alterations in this disease. FLT3ITD is a major driver of AML and is associated with poor clinical outcomes. Although FLT3 inhibitors (FLT3is) have significantly improved outcomes for patients with FLT3ITD+ AML, acquired resistance remains a major barrier to durable clinical benefit. Reactivation of RAS/MAPK signaling, often driven by activating NRAS mutations, is a major mechanism of FLT3i resistance in AML; however, effective strategies to overcome this resistance remain lacking. Here, we identify ribonucleotide reductase (RNR) as a critical therapeutic vulnerability in NRAS-driven FLT3i-resistant FLT3ITD+ AML. Activation of RAS signaling through SPRY3 loss or oncogenic NRAS mutations confers robust resistance to FLT3is, whereas pharmacologic inhibition of RNR with multiple inhibitors, as well as siRNA-mediated RNR suppression, reverses FLT3i resistance and restores FLT3i sensitivity across multiple FLT3ITD+ AML models in vitro. In vivo, clofarabine, an FDA-approved RNR inhibitor (RNRi), significantly overcomes NRAS mutation-driven FLT3i resistance. In combination with FLT3 inhibition, clofarabine markedly suppresses the progression of FLT3i-resistant AML and significantly prolongs survival in cell line-derived xenograft (CDX) models. Importantly, the therapeutic efficacy of the gilteritinib/clofarabine combination was independently validated in two genetically distinct patient-derived xenograft (PDX) models harboring different NRAS mutations, demonstrating robust reduction of leukemia burden and confirming the generalizability of RNR inhibition in primary FLT3i-resistant AML. Together, these findings identify a previously unrecognized therapeutic vulnerability in FLT3i-resistant FLT3mut+ AML and establish RNR inhibition as an effective strategy to overcome FLT3i resistance, providing a strong rationale for the clinical evaluation of RNRis in combination with FLT3is in patients with resistant AML. SignificanceAlthough FLT3 inhibitors (FLT3i) are an important therapeutic advance in FLT3ITD+ AML, resistance commonly develops. We identified ribonucleotide reductase (RNR) as a new key vulnerability in NRAS-driven FLT3i-resistant AML and demonstrated that multiple RNRis, including the FDA-approved agent clofarabine, restore FLT3i sensitivity and enhance antileukemic activity, supporting a clinically actionable combination strategy.

cancer biology↗

Critical reassessment of lipophilic dye labeling reveals negligible incorporation into small extracellular vesicles derived form serum-free cultured cells

Lipophilic dyes are widely used to track extracellular vesicles (EVs), yet their labeling efficiency toward bona fide small EVs (sEVs) remains poorly defined. Using a serum-free HEK293F system that produces endogenously fluorescent protein-tagged sEVs (sEVs-FPT) as an unambiguous reference while minimizing interference from dye-binding non-vesicular particles, we reassessed this efficiency with two orthogonal methods: nanoflow cytometry and fluorescence microscopy. PKH26, PKH67, and DiD labeled less than 0.5% of sEVs-FPT, regardless of vesicle heterogeneity. In vivo, dye-derived signals were far less abundant than tag-derived signals and failed to colocalize with them. Mechanistic evidence indicates that this failure stems from the inability of sEVs, as acellular structures, to actively internalize dye aggregates. These findings reveal a fundamental limitation of lipophilic dye-based EV tracking and underscore the need for orthogonally validated labeling strategies. One Sentence SummaryLipophilic dyes fail to label bona fide small extracellular vesicles, calling dye-based vesicle tracking into question.

bioengineering↗

High Dimensional Immune Profiling Reveals CD39 as a Correlate of Tuberculosis Disease Severity

Immune biomarkers of tuberculosis (TB) disease severity present a challenging area of research that remains poorly understood. New technologies are able to perform larger, unbiased studies that can unravel the complex host-pathogen dynamics occurring during a Mycobacterium tuberculosis infection, the causative agent of TB. In this study, we designed a high dimensional approach combining viable bacterial burden (CFU, colony forming units) with time-of-flight mass cytometry (CyTOF) analysis to profile differences in cell-type abundance and cell-type specific protein expression during states of low, intermediate and high TB disease burden. Broadly, we segregated cell-type specific immune responses into those driven by bacterial burden and/or the mycobacterial infection strain. Interrogating these immune signatures allowed us to identify ATP-catabolizing protein CD39 as a correlate of disease severity. Treatment of mice with a small molecule inhibitor of CD39 promoted effector T cell functions and CD4 T cell expansion during Mtb infection. Collectively, our data defines the differential lung immune environment between various mycobacterial disease severity states and uncovers a potential immune biomarker of infection and therapeutic immunomodulating target to aid in the treatment of TB.

immunology↗

Sequential infection reprograms the immune landscape to shape future responses

Mouse models have been instrumental in defining immune mechanisms but often fail to capture the complexity of human immunity, limiting clinical translation. A major limitation is the immunological immaturity of specific pathogen-free (SPF) mice relative to pathogen-experienced adult humans. Here, we use a sequential infection (SI) model that recapitulates cumulative pathogen exposure and define its impact on immune composition and function. Beyond the previously reported expansion of memory T cells, SI induced durable, system-wide remodeling across lymphoid and non-lymphoid tissues, reshaping innate and adaptive immune populations, tissue-resident immunity, and hematopoietic output. Single-cell transcriptomic analyses revealed inflammatory imprinting of naive CD4 and CD8 T cells, whereas memory T cells acquired enhanced effector programs coupled with reduced biosynthetic activity, transcriptional states that more closely resemble those of pathogen-experienced adult humans. Functionally, SI mice recapitulated the human response to anti-CD28 super-agonist and exhibited altered magnitude and differentiation of acute and chronic antiviral T cell responses, demonstrating that cumulative pathogen exposure reshapes both existing immunity and the generation of future immune responses. Thus, cumulative pathogen exposure coordinately remodels hematopoiesis and naive and memory lymphocyte states, establishing a durable inflammation-experienced immune landscape that reshapes both immune memory and future immune responses, with broad implications for the translational fidelity of preclinical mouse models.

immunology↗

IL-38 limits alloreactivity through modulating myeloid and T cell activation

Interleukin-38 (IL-38) is a cytokine of the IL-1 cytokine family that promotes the resolution of inflammation. Resolution mechanisms comprise the induction or recovery of immune tolerance that is lacking in various acute and chronic inflammatory pathologies, including Graft-versus-Host Disease (GvHD). The role of IL-38 in the context of immune tolerance, its primary immune cell targets and underlying molecular mechanisms are not defined. In this study, we investigated the impact of IL-38 on human alloreactivity and in a mouse model of acute GvHD. Our data suggests that monocytes differentiating into macrophages are the main cellular target of IL-38. Specifically, IL-38 reduces antigen presentation capacity in differentiating monocytes through an IL-1 family receptor-independent mechanism, which subsequently avoids T-cell activation. In parallel, IL-38 ameliorates inflammation in allogeneic settings in human and murine GvHD models by promoting the expansion of regulatory T-cells. Our findings indicate that IL-38 promotes immune tolerance during alloreactivity by affecting myeloid cells and T-cells.

immunology↗

Structural basis of substrate recognition and allosteric inhibition in human B0AT2

The SLC6 family is a major target for neuropsychiatric therapeutics. Human B0AT2 (SLC6A15) regulates amino acid homeostasis and glutamatergic transmission and is linked to major depressive disorder, yet its transport and inhibition mechanisms remain unclear. Here we report cryo-EM structures of B0AT2 in apo state and in complex with substrates (proline, leucine, methionine) and inhibitors (loratadine, tiagabine), capturing outward-open, early substrate-bound intermediate, outward-occluded, and inward-open conformations along the transport cycle. These structures reveal an early substrate-sensing mechanism at the substrate-binding pocket (S1), where a substrate-dependent rotameric switch of Phe308 remodels pocket geometry to tune substrate accommodation and selectivity. Loratadine stabilizes an outward-occluded state via allosteric inhibition at the extracellular S2 pocket, whereas tiagabine stabilizes the inward-open state through cooperative multi-site inhibition involving S1 and two previously unrecognized intracellular cavities (S3 and S4). Together with functional assays, these data define the molecular basis of B0AT2 substrate selectivity and state-dependent inhibition. Notably, the two intracellular cavities are conserved across SLC6 transporters, reflecting a shared intracellular vestibular architecture and enabling rational design of conformation-selective modulators for neuropsychiatric disorders.

biophysics↗

Rapid reduction in global chromatin loop size after acute STAG2 reconstitution in human cancer cells

Truncating mutations in the tumor suppressor STAG2, which encodes a component of the cohesin complex, are prevalent across diverse human cancers. Here, we report that acute reconstitution of physiological STAG2 levels in STAG2-mutant human glioblastoma multiforme cancer cells triggers a rapid reduction in the size of chromatin loops genome-wide. Despite this global change in chromatin loop size, early transcriptional responses to STAG2 restoration are limited to a small number of genes, most of which are induced by STAG2 reconstitution. Notably, the growth-suppressor EFEMP1 (Fibulin-3), a secreted glycoprotein that functions as an extracellular matrix-associated inhibitor of glioblastoma growth and invasion, was the only gene consistently induced across all experimental models. The most robust and conserved STAG2-induced genes all reside within intense chromatin loops whose anchors and overall intensity did not appear to change in response to STAG2 reconstitution. These findings suggest that inactivating mutations of STAG2 promote neoplastic transformation by alleviating a restriction on chromatin loop size, allowing for an expanded range of chromatin interactions that disrupts the maintenance of a tumor-suppressive transcriptome.

cancer biology↗

PRISMA: A tensor-based framework for deconstructing the genetic architecture of complex diseases, with application to diabetic retinopathy

Complex-disease GWAS compress heterogeneous, tissue-dependent genetic effects into global locus-level statistics, masking local regulatory routes through which polygenic risk contributes to disease architecture. Here we introduce PRISMA (Polygenic Risk Integration via Summary-statistics Multi-tissue Array-decomposition), a summary-statistics framework for quantifying tissue-resolved genetic heterogeneity hidden within aggregate GWAS signals. PRISMA integrates GWAS and multi-tissue cis-eQTL data using graph Laplacian-regularized block-wise factorization, preserving local linkage disequilibrium topology during decomposition. Applied to diabetic retinopathy, PRISMA deconvolved aggregated polygenic risk into three tissue-biased genetic axes corresponding to vascular-metabolic, systemic immune-inflammatory, and retina-specific neurodegenerative trajectories. The framework prioritized 549 axis-associated targets, including 403 below the conventional genome-wide significance threshold, and showed higher tissue-regulatory resolution than PCA, NMF, and K-means. A height GWAS negative-control analysis supported trait-dependent regulatory reprioritization within a shared eQTL-mappable framework. Independent single-cell transcriptomic analyses supported axis-specific enrichment across fibrovascular, immune, and retinal compartments. Exploratory vitreous humor proteomic and metabolomic profiling further nominated candidate molecular correlates of downstream convergence. PRISMA reframes complex-disease GWAS from aggregate locus discovery toward quantitative, LD-aware mapping of tissue-resolved genetic trajectories.

genomics↗

Biosynthesis of bisbenzylisoquinoline alkaloids

Bisbenzylisoquinoline alkaloids (bisBIAs) are pharmacologically valuable plant metabolites with complex stereochemical architectures, yet the catalytic principles governing their assembly have remained largely unclear. Here, we elucidate the enzymatic pathway to cyclic bisBIAs and uncover a non-canonical redox-mediated mechanism for post-assembly stereochemical control. We identify cytochrome P450 enzymes that catalyze regioselective oxidative dimerization and macrocyclization of benzylisoquinoline monomers, establishing the macrocyclic scaffold. Subsequent stereochemical specification is achieved by a paired oxidase-reductase module that selectively epimerizes a single stereocenter through a transient imine formation, converting (R,S)-configured intermediates to (S,S)-products. Reconstitution of the pathway in yeast enabled production of both native bisBIAs and non-natural analogs, demonstrating pathway modularity and engineering potential. These results establish the biochemical principle underlying bisBIA biosynthesis and provide a framework for programmable biosynthesis of these complex natural products.

biochemistry↗

Microglial pruning of extinction-ensemble synapses preserves fear memory

Fear extinction suppresses learned fear without erasing the original memory, yet how competing fear and extinction ensembles are selectively updated remains unknown. Here, we show that microglia preserve fear memory by selectively editing extinction-ensemble synapses during retrieval. In medial prefrontal cortex, microglial processes, but not somata, expand, ramify, and tighten their engagement with extinction-ensemble dendrites and spines, where they preferentially engulf excitatory postsynaptic material and bias spine remodeling toward elimination. This selectivity is instructed by local find-me, eat-me, and dont-eat-me cues: purinergic signaling recruits microglial processes, phosphatidylserine exposure licenses engulfment of extinction-ensemble synapses, and CD47-SIRP protects fear ensembles from removal. Weakening microglial recruitment or engulfment, or removing this protection, accelerates extinction without impairing fear acquisition. These findings identify microglial processes as active gatekeepers of ensemble competition and reveal a neuroimmune mechanism that preserves fear memory by limiting extinction. In BriefDuring memory updating, microglial processes selectively engage extinction-ensemble synapses rather than globally pruning active circuits. Local recruitment, engulfment, and protection cues determine this choice, allowing microglia to preserve fear memory by limiting extinction. HighlightsO_LIExtinction retrieval selectively recruits microglial processes to extinction ensembles. C_LIO_LIMicroglia preferentially engulf excitatory postsynaptic material from extinction ensembles. C_LIO_LILocal "find-me," "eat-me," and "dont-eat-me" cues determine synapse selection. C_LIO_LIDisrupting microglial pruning facilitates extinction without impairing fear learning. C_LI

neuroscience↗

Hydrocephalus caused by Katnip deletion is linked to increased ciliogenesis and reduced proliferation of neuroprogenitor cells

BackgroundKATNIP (Katanin-interacting protein), also known as KIAA0556, is one of the human genes with pathogenic variants linked to Joubert syndrome, an archetypal neurodevelopmental ciliopathy. KATNIP is a scaffolding protein with a critical role in ciliogenesis. In this study, we characterized the ciliopathy phenotypes due to KATNIP gene deletion. ResultsWe produced a Katnip null mouse model using CRISPR-Cas12a (Cpf1). The null heterozygotes appeared normal while the homozygotes died around postnatal day 9, showing severe hydrocephalus and deficiency in neuroprogenitor cell proliferation. Katnip-deficient cells in the brain have a higher rate of cilia formation and longer cilia than wild type cells. ConclusionKATNIP loss of function gives rise to hydrocephalus found in Joubert syndrome. The results indicate that KATNIP restricts ciliogenesis and cilia extension and supports proliferation of neuroprogenitor cells in the brain.

cell biology↗

Bioinspired Virus-Like Porous Silica Amplify Lipid-Mediated mRNA Delivery

Lipid nanoparticles (LNPs) have demonstrated strong potential in COVID-19 mRNA vaccines nevertheless they still face the challenges in low mRNA delivery efficacy. Virus-like porous silica (VLPSi) nanoparticles (NPs) represent a promising biomimetic delivery platform because their spiked morphology may enhance cellular internalization and promote endosomal membrane disruption. However, the application of VLPSi for mRNA has been rarely explored. In this study, hybrid lipid-VLPSi NPs were developed by combining VLPSi with either lipoplexes (LPs) or LNPs. The effects of lipid types, mass ratio of different compositions, and amine modifications of VLPSi on mRNA delivery were studied. The results demonstrated that both LP and LNP could be successfully integrated with VLPSi to form hybrid delivery systems for mRNA transfection. VLPSi could significantly enhance mRNA delivery of both LPs and LNPs due to improved cellular uptake, structural stabilization of the mRNA complex, and enhanced endosomal escape mediated by the rigid virus-like surface architecture. Among the tested lipid formulations, the ionizable lipid ALC-0315 and helper lipid DOPE with mass ratio of 5:3 was the most effective lipid composition to be integrated with VLPSi, showing the highest mRNA delivery performance. In addition, amino modification of VLPSi was found to be a critical factor for efficient mRNA delivery. Hybrid LNPs containing amino-modified VLPSi showed significantly higher transfection efficiency than those containing unmodified VLPSi. Notably, amino-modified LNP-VLPSi achieved up to fivefold higher gene expression than conventional LNPs. Overall, this study establishes VLPSi as an efficient platform for amplifying lipid-mediated mRNA delivery. Owing to its straightforward integration into widely used LNP systems, VLPSi offers an adaptable and effective strategy for advancing next-generation mRNA therapeutics.

bioengineering↗

Tunable Rigid Spikes on Virus-Like Porous Silica Enable Mechanistically Controlled Nanovaccine Platforms

Virus-like particles represent an emerging and promising vaccine platform. However, these particles are inherently mechanically soft and have limited control over particle surface architecture, thereby constraining their immunological control. Herein, we report the rational design of bioinspired virus-like porous silica (VLPSi) nanoparticles (NPs) with tunable and mechanically rigid spike architectures that function dually as antigen delivery carriers and immune adjuvants. Using ovalbumin (OVA) as a model antigen, we systematically elucidate the spiky structure-function relationship in antigen delivery and immune response. VLPSi NPs exhibit good biocompatibility, sustained antigen release, and markedly enhanced cellular uptake and endosomal escape compared with soft spike and spherical counterparts. Mechanistic investigations combining molecular dynamics simulations and proteomic analyses reveal that rigid spike architectures reduce the energetic barrier for cellular internalization and concurrently activate dual pathways involving endosomal Toll like receptors and calcium signaling. Consequently, VLPSi with long spikes elicit significantly enhanced humoral and cellular immune responses, outperforming the particles with shorter spikes, spherical shape as well as clinically used alum adjuvant. To demonstrate translational potential, bioinspired antibacterial vaccines were produced by loading Staphylococcus aureus surface protein rEsxB. The VLPSi-based vaccine elicited robust protective immunity to achieve complete (100%) survival following lethal challenge without detectable adverse effects, whereas traditional Alum-adjuvanted formulation conferred only minimal protection, with a survival rate of 10%. Collectively, this work establishes VLPSi with tunable spikes as a mechanistically controlled platform for next generation vaccines. Graphic Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=145 SRC="FIGDIR/small/720861v1_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@1f6c13eorg.highwire.dtl.DTLVardef@1090d07org.highwire.dtl.DTLVardef@1364926org.highwire.dtl.DTLVardef@fc68ab_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

mChIP-seq for Multiplex and Multifactorial Epigenomic Profiling Uncovers Cancer-specific Histone Features in Cellular and Circulating Nucleosomes

Epigenomic profiling facilitates access to investigate regulatory roles of histone marks in a type-specific cell, and serves as a critical path for discovering noninvasive epigenetic models in cell-free nucleosomes. Here, we present mChIP-seq, an epigenomic profiling technology that is compatible with both cell and cell-free samples for synchronously profiling multifactorial epigenetic landscapes on multiple samples. Combining sample indexing in a single reaction with a pool-and-split strategy for immunoprecipitation, mChIP-seq enhances efficiency and reduces cost. Using mChIP-seq, we profiled H2A.Z and 10 histone modifications in cell lines representing 9 cancer types. Integrative analyses further revealed an atypical association of H2A.Z and H3K4me3 at promoter regions in cancer. Based on mChIP-seq, we developed cf-mChIP-seq for circulating nucleosomes, which requires as little as 25 l of plasma per profile. Profiling 38 plasma samples for H2A.Z, H3K4me3, H3K27ac, and H3K9me3 with cf-mChIP-seq revealed distinct histone mark-associated cfDNA fragment patterns in breast cancer versus healthy control, highlighting the potential of cf-mChIP-seq to expand liquid biopsy methodologies. These results demonstrate that mChIP-seq is a widely applicable technology for large-scale epigenomic profiling of nucleosomes in cellular or cell-free forms.

genomics↗

Biomimetic virus-like mesoporous silica nanoparticles activate NK cells indirectly via monocyte crosstalk

Cancer immunotherapies show clinical promise but often rely on T-cell priming and are limited by tumor heterogeneity and the immunosuppressive tumor microenvironment (TME). Innate immune activation offers a complementary strategy, with specific aim in natural killer (NK) cell activation for antigen-independent response. Biomimetic nanoparticles combining virus-like morphology with cell membrane (CM) coating offer a strategy to engage this innate immune axis. This study investigates virus-like mesoporous silica nanoparticles (VLPSi) with tunable spikes, surface functionalization, and CM coating as innate immunity modulators. Optimization revealed that longer spikes, amine functionalization, and CM coating synergistically enhance NK cell activation within human PBMCs, as indicated by CD69/CD25 upregulation and IFN-{gamma} secretion. CD14+ monocyte depletion attenuated activation, identifying monocyte-dependent crosstalk as a key mechanism. In purified NK cells, engineered CM-coated VLPSi induced early activation and supported feeder-free expansion. These results define topology, surface chemistry, and CM coating as parameters for innate immune modulation. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=69 SRC="FIGDIR/small/720074v1_ufig1.gif" ALT="Figure 1"> View larger version (18K): org.highwire.dtl.DTLVardef@db5cdorg.highwire.dtl.DTLVardef@1ab41eorg.highwire.dtl.DTLVardef@127428dorg.highwire.dtl.DTLVardef@82609a_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

U-Probe: universal agentic probe design for imaging-based spatial-omics

Probe design for fluorescence in situ hybridization (FISH) underpins spatial transcriptomics, three-dimensional genome studies, and clinical diagnostics, yet remains constrained by two challenges: dependence on expert knowledge for parameter selection and quality evaluation, and the inability of existing tools to accommodate the diverse probe architectures introduced by rapidly emerging methods. Here we present U-Probe, a universal and agentic probe design platform. U-Probe employs a declarative configuration system with a directed acyclic graph (DAG)-based assembly engine that supports arbitrary probe structures from established protocols such as MERFISH, seqFISH, and MiP-seq to entirely novel architectures without code modifications. Integrated LLM-based AI agents enable conversational design workflows, allowing users to specify experimental goals in natural language and receive synthesis-ready probe sequences. We validated U-Probe in three scenarios: agent-driven MiP-seq panel design for influenza-infected mouse lung tissue, genome-tiling DNA-FISH for herpesvirus detection, and a novel RCA-based ligation probe for single-nucleotide mutation discrimination. U-Probe is available as an open-source tool with CLI, Web, and agent interfaces.

bioinformatics↗

Biohybrid Robots with Embedded Conductive Fibers for Actuation, Sensing, and Closed-loop Control

Living organisms achieve adaptive actuation through the seamless integration of neural motor control circuitry and proprioceptive feedback. While biohybrid robotics aims to replicate these capabilities by merging engineered muscle with synthetic scaffolds, the field remains limited by interfaces that lack the efficiency and closed-loop regulation of natural neuromuscular systems. Here, we introduce a biohybrid muscle actuator system featuring a bioelectronic interface based on soft poly(3,4-ethylenedioxythiophene) (PEDOT) fibers for stimulation and sensing. These fibers conformally couple to muscle tissues, eliciting robust contractions at voltages as low as 1 V--requiring ultra-low power (0.376 {+/-} 0.034 mW) and preserving long-term tissue viability. By leveraging the independent addressability of these fibers, we demonstrate selective actuation of individual muscle units to achieve precise spatiotemporal control of a two-muscle-powered walking biohybrid robot, reaching a locomotion speed of 5.43 {+/-} 0.79 mm/min. When configured as strain sensors, the fibers exhibit a high gauge factor of 155.45 {+/-} 6.59 and resolve contractile displacements within tens of micrometers. We demonstrate that this sensing modality can be integrated into a closed-loop controller to autonomously modulate stimulation based on real-time feedback, significantly mitigating muscle fatigue (p = 0.038) during continuous operation. This work establishes a versatile platform for efficient actuation and intrinsic feedback sensing, providing a blueprint for efficient, autonomous, and adaptive biohybrid machines. SummarySoft conductive fibers enable a bioelectronic interface for low-power actuation and closed-loop control in biohybrid robots.

bioengineering↗

Epigenome editing of human hematopoietic stem cells enables sustained and reversible thrombosis prevention

Thrombosis remains a major cause of cardiovascular and cerebrovascular diseases, driven in large part by platelet activation and aggregation. Because platelets are continuously produced from hematopoietic stem cells (HSCs), durable reprogramming of HSC output offers a unique opportunity for a one-time antithrombotic intervention. Here, we show that DNA methylation-based epigenome editors delivered transiently as RNA result in stable, heritable gene silencing in primary human HSCs that persists through long-term self-renewal and megakaryocytic differentiation, while remaining reversible through targeted demethylation. Targeting the platelet integrin {beta}3 (ITGB3), this approach achieves robust, sustained repression and yields platelets with impaired aggregation. Extending this framework to additional genetically-nominated platelet targets establishes HSC epigenome editing as a durable and reversible strategy to modulate thrombotic risk and highlights broader opportunities to engineer hematopoiesis.

genomics↗