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Biology subjects

Lu, X.

Publications and source records attributed to Lu, X..

At least 73 records · Page 4Linked to original sources

Methionine metabolism and the NOP2 methyltransferase are essential for MYC-Driven liver tumorigenesis.

Hepatocellular carcinoma (HCC) represents the third leading cause of cancer-related death worldwide and has been increasing in developed nations.1,2 The MYC oncogene or its paralogs are frequently amplified or overexpressed in subtypes of cancer associated with stem cell-like features and worse clinical outcomes,3,4 including in liver cancer.5 Unfortunately, selective inhibitors that target MYC or its transcriptional program are not yet clinically available for therapy of HCC. Here, we identified methionine metabolism as a selective vulnerability for MYC but not RAS-driven liver cancers. MYC-driven liver cancer cells are methionine dependent, with markedly diminished tumor growth when mice are fed a methionine low diet. While RAS-driven liver cancer was resistant to a low methionine diet. S-adenosylmethionine (SAM), the predominant methyl donor, partially rescues cell proliferation following methionine depletion, suggesting that methylation processes are especially critical in the context of MYC high tumor cells. Heavy isotope methionine tracing in MYC high cells identified increased levels of m5C nucleotides. We found NOP2, an rRNA m5C-methyltransferase, was regulated by both MYC overexpression and methionine abundance linking the two processes. Methionine depletion reduced methylation of multiple 28S rRNA residues as did NOP2 knockdown. Depletion of NOP2 selectively inhibited MYC liver cancer cell proliferation and in vivo tumor growth. Thus, methionine catabolism is critical for MYC-driven liver tumorigenesis and the rRNA methyltransferase NOP2 may serve as a new therapeutic target in liver cancer.

cancer biology↗

Identification of an epigenetically and phenotypically distinct peritumoral glioblastoma cell population linked to inferior patient outcome

Glioblastoma (GB) is an aggressive and therapy-resistant primary brain tumor with dismal prognosis. Lethality is in most patients caused by a local peritumoral (Edge) relapse near the resection cavity. This region is insufficiently studied and experimental models are scarce. We have analyzed matched tissue samples and cell cultures from bulk tumors and Edge regions of 11 GB patients. Genomic profiling displayed similar genetic alterations and subclonal distributions of matched bulk and Edge regions. Functional, phenotypic and combined single nucleus (sn) RNA-seq and ATAC-seq analyses showed distinct differences between bulk and Edge GB cells with similar shifts across patients. Sn multiomics uncovered a subset of Edge cells defined by unique chromatin accessibility signatures and elevated mesenchymal and immune gene expression. Integrated computational and functional investigations converged on microglia-derived Oncostatin-M as a driver of the Edge-unique phenotype, and high expression of Edge-related signatures correlated with inferior patient outcome in independent GB cohorts.

cancer biology↗

Enhancing volumetric microscopy with blind computational correction of spatially variant aberrations using neural field representation

Studying biological processes across multi-millimeter scales requires imaging systems that combine high spatial resolution with a large field of view (FOV). However, optical aberrations degrade image quality, particularly in large-FOV systems where distortions gradually worsen toward the periphery. Existing methods for correcting field-dependent aberrations are limited and often impractical. Hardware-based solutions such as adaptive optics demand additional components and sample manipulation, increasing system complexity and experimental burden. Computational approaches, while promising, typically rely on exhaustive point spread function (PSF) calibration or large training datasets, restricting their applicability. We introduce a self-supervised algorithm that simultaneously estimates spatially varying aberrations and reconstructs 3D sample structure from a single blurred image--without PSF calibration or training data. Our method was implemented on optically cleared mouse hippocampal neurons and cortical vasculature imaged with oblique plane microscopy (OPM), as well as in vivo mouse retinal vasculature captured with adaptive optics scanning laser ophthalmoscopy (AOSLO), where PSF calibration is infeasible. The algorithm predicts and corrects aberrations across multi-millimeter FOVs, enhances contrast in low signal-to-noise regions, and reveals critical structural details in neuronal and vascular systems that are obscured in raw images. This approach enables high-resolution, large-scale imaging without hardware modifications, expanding the accessibility of advanced microscopy techniques.

bioinformatics↗

A Bear-Specific Coding Exon in TMEM41B Is Associated with Cold Adaptation

AbstractBears exhibit an unusual form of hibernation in which core body temperature remains relatively high despite profound suppression of whole-body metabolism. How such a warm yet hypometabolic state is achieved remains poorly understood. Here, through integrative analysis of 238 RNA-seq datasets spanning seven species, we identify transmembrane protein 41B (TMEM41B) as an evolutionarily conserved factor associated with thermogenic capacity. Loss of Tmem41b in mice and Drosophila results in severe cold intolerance, whereas its overexpression enhances thermogenic performance, supporting a conserved role in heat production. Comparative genomic analyses reveal a bear-specific 51-amino acid N-terminal extension in TMEM41B, arising from a 5' untranslated region mutation that converts a premature stop codon into coding sequence. Interactome profiling indicates that this bear-specific isoform differs from the canonical TMEM41B in its protein interaction landscape, including reduced association with components of mitochondria-associated endoplasmic reticulum membranes such as voltage-dependent anion-selective channel protein 1 (VDAC1). Consistent with this altered interaction profile, the extended isoform is associated with reduced mitochondrial oxidative activity. Functional analyses further suggest that the 51- amino acid extension modulates multiple cellular programs, including suppression of oxidative phosphorylation and myogenic differentiation alongside activation of osteogenic pathways, collectively biasing cells toward a hypometabolic state. Notably, expression of the polar bear TMEM41B isoform in mice induces a torpor-like phenotype under fasting conditions. Together, these findings identify TMEM41B as a conserved regulator of thermogenic capacity and suggest that evolutionary modification of its N terminus may contribute to metabolic suppression and energy conservation during bear hibernation.

evolutionary biology↗

Loss of nsp14-exonuclease activity impairs the replication, proofreading, fitness and pathogenesis of SARS-CoV-2

Coronaviruses (CoVs) replicate their RNA genomes with increased fidelity than other RNA viruses, a mechanism mediated by the proofreading and recombination activities of the exoribonuclease domain of replicase nonstructural protein 14 (nsp14-ExoN). Both murine hepatitis virus (MHV) and SARS-CoV tolerate nsp14-ExoN loss-of-function mutations (ExoN-) (D90A and E92A) but have impaired replication fidelity and pathogenesis yet identical substitutions in MERS-CoV and SARS-CoV-2 have been reported to be lethal. Here, we report a saturation mutagenesis approach facilitating the recovery and analysis of several constellations of SARS-CoV-2 nsp14 ExoN-inactivating, loss-of-function substitutions, including the canonical D90A and E92A. Biochemical assays with purified WT or ExoN- nsp10-14 fusion proteins confirmed that active site substitutions abolished ExoN activity (ExoN-). SARS-CoV-2 ExoN- viruses had impaired replication, RNA synthesis, and recombination, as well as decreased replication fidelity and loss of fitness in vitro. ExoN- viruses were significantly attenuated for replication in human primary airway epithelial cells and were attenuated for replication and pathogenesis in WT mice as well as the highly susceptible K18 transgenic mice. In the absence of interferon signaling in vivo, SARS-CoV and SARS-CoV-2 ExoN- viral replication could be nearly fully restored. These results demonstrate that SARS-CoV-2 ExoN- are viable but highly impaired for replication, fitness, and fidelity in vitro as well as innate immune antagonism and pathogenesis in vivo. Collectively, our results solidify the multiple critical roles for nsp14-ExoN across CoV genera and establish new approaches for rescue and analysis of loss-of-function substitutions for studies of CoV replication, pathogenesis, and evolution.

microbiology↗

KDM7B-mediated demethylation of RNF113A regulates small cell lung cancer sensitivity to alkylation damage

Chemoresistance remains a major obstacle to effective cancer treatment, often driven by enhanced DNA repair mechanisms that enable tumor cells to withstand genotoxic therapies. One such pathway involves the atypical DNA damage repair complex ALKBH3-ASCC, activated by the E3 ligase RNF113A in response to alkylation damage. We previously showed that SMYD3-dependent methylation of RNF113A stimulates this pathway, enhancing DNA repair and promoting resistance. Here, we identify KDM7B/PHF8 as the bona fide RNF113A demethylase, establishing one of the first functional examples of a dynamic, reversible non-histone methylation event regulating genome integrity. KDM7B antagonizes SMYD3 activity by maintaining low levels of methylated RNF113A, thereby limiting ASCC activation and sensitizing cancer cells to alkylating agents. To dissect this regulation in depth, we focused on small cell lung cancer (SCLC), a particularly aggressive malignancy characterized by limited therapeutic options and rapid acquisition of resistance. In SCLC, high KDM7B levels correlate with improved patient prognosis, whereas xenografts with reduced expression exhibit diminished responses to alkylating treatment. Moreover, CRISPR-based on/off modulation of KDM7B in genetically engineered SCLC mouse models demonstrates its central role in determining tumor response to chemotherapy. Our findings position the RNF113A-ASCC axis as a central modulator of chemoresistance, regulated through a post-translational methylation switch representing an innovative therapeutic vulnerability that could be exploited to enhance the efficacy of alkylating agents. Targeting this pathway may provide new opportunities to overcome chemoresistance, with KDM7B levels serving as a predictive biomarker to guide treatment in SCLC.

cell biology↗

Deuterated Polyunsaturated Fatty Acids Alleviate In Vitro Skeletal Muscle Dysfunction Induced by Oxidative Stress

Excessive oxidative stress drives lipid peroxidation and contributes to skeletal muscle atrophy in a range of musculoskeletal diseases. Polyunsaturated fatty acids (PUFAs) are essential components of muscle cell membrane phospholipids and are especially susceptible to peroxidation due to the presence of double bonds. Currently, therapeutic options targeting lipid peroxidation to prevent muscle wasting are limited. Substituting the hydrogen atom at the bis-allylic position with deuterium could conceivably limit lipid peroxidation while retaining enzymatic PUFA metabolism. Here we investigated the potential role of deuterated PUFAs (D-PUFAs) in protecting against muscle cell dysfunction under conditions of elevated oxidative stress. Both native (H-) and deuterated (D-) forms of long chain PUFAs including arachidonic acid (ARA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) stimulated in vitro muscle cell growth and development in the absence of oxidative stress. D-ARA, D-EPA, D-DPA, and D-DHA each protected cultured myotubes against the deleterious effects of direct exposure to reactive oxygen species (ROS) by limiting lipid peroxidation. In contrast, H-ARA, H-EPA, H-DPA, and H-DHA each increased sensitivity to ROS-induced lipid peroxidation and exacerbated oxidative stress-induced muscle cell dysfunction. Deuterated short chain linoleic acid (D-LA), alpha linolenic acid (D-ALA), as well as D-ARA and D-EPA (but not D-DPA or D-DHA) also protected against the deleterious effects of ferroptosis inducer erastin on myogenic differentiation. Finally, D-PUFAs modulated local expression of endogenous antioxidant enzymes and muscle-specific protein ligases. Overall, our study suggests a promising role of D-PUFAs as novel therapeutics to protect against skeletal muscle dysfunction induced by oxidative stress.

physiology↗

Versatile high-speed volumetric imaging from microscopic to macroscopic scale by self-adaptive oblique plane microscopy

There is an increasing need for large-scale high-speed volumetric recording in complex multi-cellular model systems to define dynamic processes. Oblique plane microscopy (OPM) provides a solution that features oblique illumination, rapid optical scanning, and remote focusing to achieve real-time 4D microscopy. OPM implements light sheet imaging via a single primary objective lens, making the entire space below the objective accessible for large specimens, such as living mouse brain. Yet it is challenging to adopt OPM beyond a microscopic scale (i.e. size < 1mm), limiting its broad applications. Here we present a self-adaptive OPM that leverages Abbes sine condition to unlock its flexibility across a range of field-of-views (FOVs) (up to 8 mm2) and resolutions (down to 2.2 {micro}m3). This versatility enables brain-wide single neuron volumetric calcium imaging in behaving larval zebrafish (1x0.4 mm2 FOV at 5 Hz) and capillary blood cell tracking in living mouse brain (>3x3 mm2 FOV) with a sweeping 0.32 mm wide volume section at 100 Hz. In optically cleared mouse brain, the flexibility allows a screen-and-zoom capability by sequentially imaging the whole brain at low-and-high magnifications to locate and resolve subcellular structures such as dendritic tress and spines. By offering a switchable imaging resolution, volume, and speed, the self-adaptive OPM achieves a versatile platform for studying a wide range of multi-cellular model system, whether in vivo or fixed and optically cleared.

bioengineering↗

Development of a universal imaging "phenome" using Shape, Appearance and Motion (SAM) features and the SAM Observation Tool (SPOT)

Cells are plastic, highly heterogeneous and change over time. High-content timelapse imaging promises to reveal dynamic cell behaviors, enabling more accurate identification of cell state and cell fate prediction for biological hypothesis generation and perturbation screens. To empower live-cell imaging based screen, we report the development of 1) a Shape, Appearance, Motion (SAM) "phenome"; a universal set of 2185 image-derived features that act as a image-"transcriptome" to comprehensively quantify an objects instantaneous phenotype; 2) the SAM-Phenotype-Observation-Tool (SPOT), for image-"sequencing" analysis of phenomes. We validated the effectiveness of unbiased SAM-SPOT workflow on publicly available computer vision and 2D single cell imaging datasets. Importantly, we demonstrated that SAM-phenome outperformed features generated by deep learning AI models trained on >1 million fixed single cell and >5000 single cell video frames, respectively. SAM-phenome and SPOT delivers high-throughput, object-treatment-agnostic, comprehensive screening readouts of dynamics, promising to advance novel molecular target discovery and new medicine development.

bioinformatics↗

Identifying phenotype-genotype-function coupling in 3D organoid imaging using Shape, Appearance and Motion Phenotype Observation Tool (SPOT)

Live cells in tissue are plastic, phenotypically dynamic, and modify their function in response to genetic and environmental perturbations. To unleash the power of live-cell imaging to identify phenotype-genotype-function coupling over time, we report the development of a standardized Shape-Appearance-Motion (SAM) "phenome" and SAM-Phenotype-Observation-Tool (SPOT), that act as an image-"transcriptome" and image-"transcriptome analyzer" respectively, and provide unbiased and comprehensive description of morpho-dynamic phenotypes without prior knowledge. We developed and applied SAM-SPOT to our simulated organoids database with known ground-truth and >1.6 million mouse and human organoid instances with defined genetic and chemical perturbations. SAM-SPOT can effectively and robustly characterize 3D morpho-dynamics from 2D projection videos. Combined with single-cell RNA sequencing, SAM-SPOT revealed that altered WNT signaling, but not mutant RAS or p53, predisposes intestinal organoids to irregular morphogenesis. SAM-SPOT advances biomedical discovery by empowering live-cell imaging to identify phenotype-genotype-function relationships through large-scale and cost-effective label-free live-cell imaging.

cancer biology↗

Cross-Species Cortical Geometry Reveals Conserved Gradients Across Primates and Human-Specific Expansion

The primate cerebral cortex, characterized by its complex structural geometry, underlies advanced cognitive functions and represents a defining feature distinguishing primates from other mammals. However, cross-species patterns of cortical geometry and the links between human cortical geometry and transcriptional architecture remain poorly understood. We developed a geometry-based cross-species cortical alignment framework to systematically investigate the similarities and differences in structural connectivity and cortical expansion characteristics among macaques, chimpanzees, and humans, and additionally explored the transcriptional underpinnings of human cortical geometry. Our analysis revealed conserved spatial patterns of cortical geometric features across species, providing the foundation for constructing a cross-species structural common space to support the alignment framework. We found that primary sensory, somatomotor, and face-selective regions exhibited high structural connectivity similarity across species, whereas prefrontal and parietal association cortices displayed significant divergence. We also identified disproportionate cortical expansion in the default mode network, with a consistent expansion trend across different evolutionary lineages in primates. Furthermore, neuroimage-transcription analysis indicated that cortical geometric features were correlated with transcriptional profiles enriched in neurodevelopmental and connectivity-related pathways. These results highlight a conserved yet hierarchically differentiated organization of the cerebral cortex in primates, providing new insights into the biological basis of human brain evolution.

neuroscience↗

CDH3 as a Novel Therapeutic Target in Basal-like Double-Negative Prostate Cancer

PurposeBasal-like (also known as double-negative) prostate cancers are aggressive tumors that lack effective targeted therapies. We aimed to delineate the role of CDH3 (P-cadherin) in basal-like prostate cancer and evaluate CDH3-directed therapeutic strategies. MethodsWe integrated genetically engineered mouse models (GEMMs) of prostate cancer, bulk and single-cell transcriptomic analyses, and a suite of in vitro and in vivo experiments. CDH3 expression and associated signaling pathways were examined in Pten/Apc double-knockout mouse prostates and human datasets. Functional studies included antibody-drug conjugate (ADC) cytotoxicity assays and the development of chimeric antigen receptor (CAR) T cells targeting CDH3, tested in prostate cancer cell lines and xenograft models. ResultsPten/Apc double deletion in prostate GEMMs led to highly aggressive tumors with markedly elevated CDH3 expression and enrichment of non-canonical WNT signaling components. Transcriptomic analyses of patient-derived prostate tumors confirmed that CDH3 is significantly upregulated in basal-like prostate cancer subtypes relative to luminal subtypes. Single-cell RNA sequencing revealed CDH3 expression predominantly in basal epithelial cells. Mechanistically, we found that active YAP1 signaling and a WNT5A-ROR2 non-canonical WNT axis drive CDH3 expression. Targeting CDH3 with a CDH3-specific ADC induced potent, antigen-dependent killing of CDH3 prostate cancer cells in vitro and significantly suppressed tumor growth in in vivo metastatic prostate cancer models. Likewise, CDH3-targeted CAR T cells specifically recognized and lysed CDH3-expressing prostate tumor cells while sparing CDH3-negative cells, leading to tumor regression and improved survival in mouse models, especially when combined with PD-1 checkpoint blockade. ConclusionsCDH3 is a key marker and functional driver of basal-like prostate cancer. Therapeutic strategies leveraging CDH3, including ADCs and CAR T cells, demonstrate strong preclinical efficacy, supporting the development of CDH3-targeted treatments to overcome resistance in aggressive prostate cancer.

cancer biology↗

Brain-wide Genome Editing via STEP-RNPs for Treatment of Angelman Syndrome

Brain-wide genome-editing remains a major hurdle for the treatment of neurogenetic disorders. Here, we report a non-viral, non-nanoparticle, chemical modification-based method, called Stimuli-Responsive Traceless Engineering Platform (STEP) that achieves highly efficient and brain-wide genome-editing of neurons in mice. Using cholesterol-based STEP as a lead, we show that a single administration of STEP-ribonucleoproteins (RNPs) results in functional genetic rescue with significant improvements across a battery of neurobehavioral domains in the Angelman syndrome (AS) mouse model. No significant off-target events or general toxicity effects are observed. STEP-RNPs are also highly efficient at editing human neurons and cortical brain organoids differentiated from AS patient-derived iPSCs. scRNA-seq analysis confirms functional genetic rescue via reactivation of Ube3a/UBE3A expression in human and mouse STEP-RNP-treated neuronal cells. Genome editing via STEP-RNPs has broad applications and the potential to treat many other neurogenetic disorders.

genetics↗

A multi-tissue atlas of genetic regulatory effects in sheep

Characterizing the impact of genomic variants on genome function and ultimately complex traits in livestock is essential for the development of sustainable precision agriculture and comparative genomics. Here, as part of the Farm animal Genotype-Tissue Expression (FarmGTEx) project, we present the pilot phase of the SheepGTEx resource through analyzing 6,761 RNA-sequencing samples of 51 primary tissues in a multi-breed population of sheep. We identify millions of regulatory variants associated with seven types of molecular phenotypes, and fine-map 322,468 primary and 114,017 non-primary effects, revealing a high degree of regulatory allelic heterogeneity. We systematically characterize the pleiotropic effects of these variants on molecular phenotypes, assess their context-specific regulatory patterns across tissues, breeds, sexes, and developmental stages, as well as explore their evolutionary constraints across mammals. Finally, we demonstrate the substantial potential of the SheepGTEx resource (https://sheepgtex.farmgtex.org), by providing examples of regulatory mechanisms underpinning 34 complex traits, population divergence between European and Asian breeds, and adaptive evolution in sheep over the past ten millennia.

genomics↗

SIMAIS: A swarm intelligence inspired biosensor for rapid protein detection

Swarm intelligence, the collective behaviour of animals such as birds, fish, and ants, arises from simple local interactions and enables survival, efficient foraging, and decision-making without central control. Inspired by this principle, we aimed to harness swarm intelligence for biosensing applications. Conventional assays often struggle with limited sensitivity, long processing times, and the need for specialised instruments, restricting their use in decentralised healthcare. Here we developed a swarm intelligence of microbead-inspired, artificial intelligence (AI)-assisted, and smartphone-based (SIMAIS) biosensing platform that can transform invisible molecular recognition into visible, macroscale patterns. Millions of antibody-coated magnetic microbeads (MBs) organise into magnetically induced structures upon binding protein biomarkers, with the resulting patterns correlating directly to biomarker concentration. Using interferon-gamma (IFN-{gamma}) as a model biomarker, we demonstrate that this approach delivers results within 10 minutes and achieves a tenfold increase in sensitivity compared to conventional lateral flow assays. Robust performance in human serum and urine confirms clinical applicability. By mimicking natural swarm behaviour, this platform introduces a new biosensing paradigm that bridges biology and engineering. Its versatility, speed, and ease of use highlight its potential for decentralised diagnostics, early disease detection, and broader applications in point-of-care healthcare.

biophysics↗

An oncogenotype-immunophenotype paradigm governing the myeloid landscape in genetically engineered mouse models of prostate cancer

Distinct oncogenotypes sculpt divergent myeloid landscapes in prostate cancer. Using prostate-specific Ptenpc-/-, Ptenpc-/- Trp53pc-/-, Ptenpc-/- Smad4pc-/-, and Ptenpc-/- Trp53pc-/- Smad4pc-/- models, we identify a Smad4-loss-driven neutrophil-enriched subtype (NES) characterized by CXCL5, CXCL2, and CCL20 upregulation, polymorphonuclear myeloid-derived suppressor cell (PMN-MDSC) infiltration, and immune checkpoint resistance. In contrast, Smad4-intact tumors form macrophage-enriched subtypes (MES) responsive to immunotherapy. Mechanistically, Smad4 ablation activates YAP signaling and elevates histone epigenetic regulatory enzymes that enhance histone modification, chromatin accessibility, and transcription of neutrophil-recruiting cytokines. Genetic or pharmacologic inhibition of these enzymes suppresses chemokine expression, reduces neutrophil accumulation, restores CD8 T-cell activity, and limits tumor growth in immunocompetent hosts. Analyses of human prostate cancers support the findings from the murine NES prostate tumors. These findings establish a Smad4-YAP-epigenetic axis linking oncogenotype to immunophenotype and uncover a therapeutic vulnerability within the myeloid-dominant prostate tumor microenvironment.

cancer biology↗

M1 Macrophage-Derived Small Extracellular Vesicles as Synergistic Nanotherapeutics: Harnessing Intrinsic Anticancer Activity and Drug Delivery Capacity

Small extracellular vesicles (sEVs) have emerged as next-generation multifunctional nanotherapeutics due to their parental-cell traits and role in intercellular communication. Among them, immune cell-derived sEVs are uniquely positioned to couple innate immunomodulatory activities with therapeutic payload delivery, making them highly attractive for cancer therapy. In particular, M1 macrophage-derived sEVs (M1-sEVs) preserve the tumor-suppressive functions of their parent cells, including tumor microenvironment (TME) reprogramming, immune activation, and inhibition of cancer progression. However, the mechanisms by which these activities are coordinated within the TME, and whether they act independently or synergistically, remain poorly understood. Clarifying these mechanisms is crucial for harnessing their intrinsic bioactivity in combination with their natural capacity as drug delivery nanocarriers to optimize therapeutic efficacy. Here, we demonstrate that M1-sEVs exhibit intrinsic stability and circulation longevity via do not eat me ligands, as well as tumor-homing ability revealed by proteomic profiling, enabling efficient uptake and deep infiltration in breast cancer models. Functionally, M1-sEVs deliver antiproliferative microRNAs that suppress tumor metabolism, growth, and progression by inhibiting self-renewal, adhesion, migration, motility, and invasion. Importantly, by integrating this endogenous bioactivity with exogenous doxorubicin loading, we achieved synergistic efficacy: a 3-fold reduction in IC50 in vitro (0.46 M vs. 1.45 M for free drug) and 70.18% tumor growth inhibition in vivo. These findings highlight M1-sEVs as dual-action nanotherapeutics that combine innate immune-regulatory and tumor-inhibitory functions with efficient drug delivery, advancing their development as powerful platforms for cancer therapy.

bioengineering↗

Identification and characterization of emNagⅡ, a novel β-1,2-N-acetylglucosaminidase from Elizabethkingia meningoseptica

N-Acetylglucosamine exists in various forms and linkage patterns within organisms, playing a crucial role in numerous vital biological processes. However, research focusing on {beta}-1,2-linked N-acetylglucosamine within complex biantennary N-glycans on the cell surface remain largely unexplored. Currently, there is a lack of efficient tools and methods capable of directly modifying terminal N-acetylglucosamine on living cells. In this study, we identified a novel {beta}-N-acetylhexosaminidase from Elizabethkingia meningoseptica, which demonstrated favorable enzymatic stability within a pH range of 5-8 and at temperatures from 4 {degrees}C to 37 {degrees}C. This enzyme specifically cleaves non-reducing terminal {beta}-1,2-N-acetylglucosamine, enabling direct removal of this modification from oligosaccharides and native glycoproteins. More importantly, we demonstrate for the first time that this enzyme successfully removes {beta}-1,2-linked N-acetylglucosamine on living cell surfaces. Given its microbial origin and potential utility in living cell glycan editing, we have named it emNagII or cell-surface glycan-editing N-acetylglucosaminidase (csgeNagII). Through sequence analysis and alanine scanning mutagenesis, we identified a predicted active pocket containing the catalytic residue pair Asp317-Glu318, with Asp317 being essential for enzymatic activity. In summary, our findings provide an effective and reliable method for the targeted removal of {beta}-1,2-N-acetylglucosamine on living cell surfaces, establishing a foundation for further functional studies and practical applications.

biophysics↗