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Zhu, J.

Publications and source records attributed to Zhu, J..

At least 19 recordsLinked to original sources

Paired activity learning supports systematic identification of mutant-selective EGFR inhibitors

Acquired resistance to epidermal growth factor receptor (EGFR) inhibitors remains a major clinical challenge in non-small cell lung cancer (NSCLC), where successive rounds of therapy with first- and third-generation EGFR inhibitors often lead to increasingly resistant EGFR variants. In particular, EGFR L858R/T790M/C797S triple mutation renders tumors resistant to earlier-generation inhibitors, while disrupting the covalent engagement required by third-generation inhibitors such as osimertinib. Here, we developed an integrated computational-experimental framework for identifying compounds with differential activity between the triple-mutant EGFR and wild-type EGFR. Matched bioactivity measurements were leveraged to train a mutant-aware paired-activity regression framework, and the predicted candidates meeting stringent potency and mutant-preference criteria were subsequently evaluated using a support vector machine classifier for triple-mutant activity. Application of this sequential screening approach to 12 million molecules identified 16 consensus hits, including several previously reported inhibitors of drug-resistant EGFR variants. Based on their predicted differential activity and degree of prior characterization, five hit compounds were prioritized for initial biochemical evaluation, and two were selected for further biochemical, cellular and structural characterization. Mutant EGFR crystal structures in complex with the best-performing compounds revealed two distinct noncovalent binding modes within the ATP-binding cleft, demonstrating the ability of the framework to identify potent inhibitors with diverse binding modes. Together, this work illustrates how incorporating mutant-selectivity into a predictive framework as paired activities support the identification of mutant EGFR inhibitors and provide insights into their potency and selectivity. The discovered complementary structures provide experimentally defined templates for optimizing potency, mutant preference and drug-like properties of these and future compounds combating drug resistant NSCLC.

bioinformatics↗

Enzymatic extracellular matrix remodeling in ex vivo slices of aged myocardium

Cardiac aging is accompanied by extracellular matrix (ECM) remodeling and increased myocardial stiffness, which may contribute to age-associated functional decline. However, whether direct remodeling of the aged cardiac ECM can modify myocardial mechanics and function remains poorly understood. Here, we established an ex vivo living myocardial slice platform to investigate whether enzymatic remodeling of the aged ECM can alter myocardial structure, mechanics, and function. Left ventricular myocardial slices (LMS) from young and aged mice were maintained under static stretch for 48 hours using a custom 3D-printed culture setup. Aged slices were treated with collagenase and subsequently characterized using quantitative imaging, tensile testing, contractility measurements, and transcriptomic analysis. Aged myocardium exhibited increased collagen and fibronectin abundance, altered collagen network architecture, and increased stiffness compared with young tissue. Collagenase treatment reduced collagen and network complexity and reduced myocardial stiffness toward young tissue values without compromising ultimate tensile stress. Despite these structural and biomechanical changes, age-associated differences in myocardial contractility remained comparable across groups. Transcriptomic analysis indicated that treated aged tissue largely retained its age-associated molecular phenotype, despite pathway-level shifts involving metabolism, cardiac function, and inflammatory responses. These findings demonstrate that enzymatic ECM remodeling can modify the aged myocardial mechanical environment while selected functional and transcriptional features of aging persist over 48 hours. The LMS platform provides a controllable ex vivo tissue-level approach for investigating ECM contributions during cardiac aging and evaluating strategies for ECM engineering.

bioengineering↗

Venetoclax Resistance Creates Canonical Pyroptosis Vulnerability in AML

Venetoclax has transformed acute myeloid leukemia (AML) therapy, yet resistance is almost inevitable. Its diverse, often difficult-to-target drivers frequently converge on monocytic differentiation, a state that survives on MCL1 rather than BCL2. Here, we show that the very cells that escape BCL2 inhibition retain the canonical pyroptosis machinery of normal monocytes. Across 15 bulk and 4 single-cell cohorts, the canonical pyroptosis program was enriched in monocytic AML and monocytic leukemia stem cells, correlated with venetoclax resistance, and associated with inferior survival specifically after venetoclax-based therapy. In 24 cell lines and 142 patient specimens, both DPP8/9 inhibition by Val-boroPro and NLRP3 activation by lipopolysaccharide (LPS) plus nigericin preferentially killed monocytic AML cells through GSDMD-mediated pyroptosis, largely sparing non-monocytic AML and lymphoid leukemias. Venetoclax preferentially depleted primitive AML blasts but enriched a monocytic residuum vulnerable to canonical pyroptosis; combining venetoclax with Val-boroPro achieved deeper ex vivo clearance than either agent alone. In venetoclax-resistant xenografts, Val-boroPro suppressed leukemia progression, and adding venetoclax further reduced leukemia burden and prolonged survival beyond either monotherapy. Thus, venetoclax resistance itself exposes an alternative, druggable cell-death program that can be therapeutically exploited to overcome this resistance.

cancer biology↗

Rationally Engineered Self-Assembling Protein Nanoparticles for Allergen-Specific Peanut Allergy Immunotherapy

Peanut allergy is a prevalent immunoglobulin E (IgE)-mediated food allergy that can cause life-threatening anaphylaxis. Current treatment options provide limited efficacy and variable durability of protection. While allergen-displaying virus-like particles (VLPs) have shown promise, their development is often constrained by limited design flexibility and manufacturing complexity. Here, we develop self-assembling protein nanoparticles (SApNPs) displaying the major allergens Ara h 2 and Ara h 6 as a modular platform for peanut allergy immunotherapy. Using the 60-mer TIP60 scaffold, we engineer nanoparticles by expanding particle size through -helical insertion and replacing the human myosin-X segment with evolutionarily distant catfish homologs, followed by structure-guided and evolution-inspired optimization to enhance thermostability while minimizing human sequence content. Formulated with a Toll-like receptor 9 (TLR9) agonist, these allergen-displaying SApNPs confer robust protection against peanut-induced anaphylaxis in both prophylactic and therapeutic settings. Mechanistically, SApNPs exhibit prolonged lymph node retention, sustained presentation on follicular dendritic cells, and enhanced germinal center responses compared with soluble allergens, promoting allergen-specific IgG and functional T cell responses while limiting IgE escalation. Collectively, these findings establish allergen-displaying SApNPs as a rationally engineered, scalable, and modular platform for peanut allergy treatment with potential applicability to other allergic diseases.

immunology↗

Xenoglycosylation of the HIV-1 Glycan Shield Promotes Cross-Clade Neutralization and Diverse Human Antibody Lineages

Despite advances in HIV-1 envelope glycoprotein (Env)-based vaccine design, eliciting broadly neutralizing antibodies (bNAbs) remains a central challenge. Here, we identify core (1,3)-fucose as a key modulator of neutralizing antibody (NAb) induction and breadth. Uncleaved prefusion-optimized (UFO) trimers and self-assembling protein nanoparticles (SApNPs) produced in High Five (Hi5) insect cells incorporate core (1,3)-fucose into the Env glycan shield. Crystal structures of Hi5-produced BG505 UFO trimers in complex with bNAbs confirm native-like Env architecture and epitope presentation. In wild-type mice, these trimers and SApNPs elicit robust autologous and heterologous NAb responses. We then engineer Chinese hamster ovary (CHO) cells to co-express three insect- and plant-derived core (1,3)-fucosyltransferases. The resulting immunogens carry fucosylated mammalian glycans and elicit cross-clade NAb responses in mice, supporting an important role for core (1,3)-fucose in broadened neutralization. Env-specific IgE responses suggest engagement of associated immune pathways during vaccination. In ATX-Gx humanized mice, core (1,3)-fucosylated, glycan-trimmed Env elicits detectable cross-clade neutralization by week 11. Single-cell analysis identifies distinct human antibody lineages with cross-clade activity and noncanonical Env recognition. Repertoire and functional analyses uncover putatively related lineage members across two animals within the same group. Together, these findings support xenoglycosylation as a promising, germline-agnostic strategy for HIV-1 vaccine design.

immunology↗

Programmable design of functional RNAs through multimodal generative learning

RNA engineering is bottlenecked by the tight coupling among sequence, structure, and function, leaving the field reliant on heuristics or screening. We introduce RNAverse, a multimodal generative model that learns a conditionable design grammar from RNA sequences, experimental structural probing profiles, and functional annotations. Beyond setting a new state of the art across 16 predictive modeling tasks, RNAverse inverts into generative design across four distinct RNA classes through three regimes, requiring experimental testing of no more than 20 candidates per-task. Zero-shot in-painting generates snoRNAs that promote premature termination codon (PTC) readthrough, and chimeric aptazymes for ligand-controlled gene regulation, exceeding rational design or large-scale screens. In both settings, RNAverse outperforms family-adapted sequence-only baselines. Fine-tuned in-painting extends to an unseen functional class, yielding IGFBP3-binding aptamers with picomolar affinity that outperform SELEX winners. Iterative optimization engineers 5' UTRs that outperform clinical benchmarks, enhancing protein production in cell-based assays for both the Zolgensma gene therapy and the BNT162b2 COVID-19 vaccine, and boosting antibody responses to BNT162b2 in mice. Together, these results establish multimodal generative learning as a route from predictive RNA modeling to programmable specification of functional RNAs.

bioinformatics↗

Targeted RNA degradation of HIV-1 TAR element at 5'UTR by CRISPR-Cas13X blocks HIV-1 lytic reactivation

Human immunodeficiency virus type 1 (HIV-1) latency remains a major barrier to a cure. Here, we developed a hypercompact CRISPR-Cas13X.1 system to target the HIV-1 5' untranslated region (5'UTR), focusing on the transactivation response (TAR) RNA element required for Tat-dependent transcription. Following validation of a single-vector system, we screened CRISPR RNAs (crRNAs) targeting distinct 5'UTR elements and identified crRNA-TAR-2 as the most effective inhibitor of Tat-dependent reporter activity. Mechanistic analyses demonstrated that TAR targeting disrupted Tat-TAR interactions. In HIV-1 infection models, Cas13X.1-mediated TAR targeting reduced HIV-1 Gag precursor (p55) and capsid (p24) protein expression, as well as gag and tat transcript levels, accompanied by activation of the PKR-eIF2a; antiviral pathway. TAR targeting also suppressed viral gene expression and reactivation in multiple latency models and reduced viral load in HIV-1-infected primary peripheral blood mononuclear cells (PBMCs). These findings establish HIV-1 TAR RNA as a target for Cas13X.1-mediated antiviral activity and support RNA-targeting CRISPR systems as a potential strategy to suppress HIV-1 infection and reactivation.

microbiology↗

BioMod: Biological Module Tokenization for Single-Cell Foundation Modeling

Single-cell foundation models typically represent cells as flat sequences of individual genes, requiring higher-order biological organization to be inferred implicitly from sparse expression profiles. Similar to the evolution from character-level to semantic tokenization in natural language processing,we hypothesize that cellular states can be more efficiently represented using biologically meaningful intermediate units. Here we present BioMod, a 50-million-parameter single-cell foundation model that introduces biological modules as representation units between genes and cells. BioMod constructs an overlapping vocabulary of 660 biological modules derived from curated pathways and data-driven gene programs, replacing thousands of gene-level inputs with compact module representations. Pretrained on approximately 73 million human cells using high-ratio module masking with an asymmetric decoder, BioMod achieves state-of-the-art performance across cell-type annotation, zero-shot batch integration, perturbation-response prediction and drug-response forecasting while maintaining a compact architecture that enables efficient inference on a single GPU. Module-level analyses further demonstrate that BioMod captures biologically meaningful cellular programs and preserves pathway-level organization.

bioinformatics↗

The Onset of Breathing at Birth Switches Off Regenerative Capacity

Many mammalian tissues, including the central nervous system (CNS), lose regenerative capacity in adulthood, but when and how this transition is initiated remains unclear. By monitoring mTOR activity, an evolutionarily conserved readout of cellular growth and intrinsic regenerative potential, we found that mTOR signaling declines within minutes after birth in murine CNS neurons and in other organs such as the heart and skeletal muscles. Focusing on retinal ganglion cells (RGCs), we show that this abrupt decline is driven primarily by CO2 exhalation following the onset of breathing after birth. Using real-time in vivo imaging of RGCs during the earliest postnatal period, we further discover that breathing-induced CO2 exhalation rapidly causes intracellular alkalinization, activates an AMPK-family kinase, SNF-related kinase (SNRK), which in turn suppresses mTOR signaling. Importantly, this process remains reversible in adulthood: CO2 inhalation or Snrk deletion restores mTOR activity in RGCs and enables robust regeneration of their axons after injury. Similar CO2 inhalation-induced mTOR reactivation occurs across multiple cell types and organs, suggesting a general mechanism by which breathing-associated CO2/pH signaling shapes the regenerative capacity across life and pointing to a potential CO2-based strategy for promoting tissue regeneration.

neuroscience↗

Dietary selenium deficiency drives sex-specific circadian disturbance through redox imbalance and causes early systolic dysfunction in mice

Background: Selenium is a vital trace element involved in antioxidant defence and cardiovascular health. Although selenium deficiency is implicated in cardiomyopathies, its early cardiac effects and underlying mechanisms remain poorly defined. Methods: C57BL6/Njr mice were fed either a selenium deficient or control diet for 12 weeks. Systemic selenium status, cardiac function by echocardiography, left ventricular (LV) transcriptomic profiles, redox balance, and circadian pathway markers were assessed, including sex-specific analyses. Results: Selenium deficiency reduced plasma selenium levels without inducing overt cardiac hypertrophy or fibrosis. Echocardiography showed preserved ejection fraction and fractional shortening but reduced global longitudinal strain, indicating early systolic dysfunction. Cardiac stress markers were increased predominantly in male mice. Left ventricular RNA sequencing revealed enrichment of pathways related to cardiac remodelling, redox regulation, mitochondrial function, and circadian rhythm. Additional protein and metabolic analyses supported sex-specific redox circadian alterations, with males showing a more pronounced stress response profile. Conclusions: Dietary selenium deficiency induces early myocardial dysfunction and molecular remodelling before overt cardiac failure. These changes are associated with redox and circadian pathway disruption and show sex specific features, suggesting that selenium contributes to cardiac homeostasis through sex dependent redox circadian regulation.

molecular biology↗

When label-free morphology is sufficient for targeted cellular measurements

Label-free morphology captures cellular responses, but its ability to substitute for targeted cellular measurements depends on the intended use. We assess measurement sufficiency using nearly 10 million paired phase-reporter observations across 1,000 gene knockouts, 52 fluorescent reporters and 73 A549 screens. Ten predictors differed in recovery across held-out fields, genes and screens. Same-cell pairing controls identified reporter-state information beyond perturbation averages and measured covariates. Perturbation ranking often persisted despite reduced variation in predicted response magnitudes. Predictions of held-out knockout responses retained a median 79% of the strongest hits, whereas functional-term retention varied. Atlas-derived criteria identified 30 quantitative and 7 ranking proxies for a fixed ensemble, with reference reproducibility constraining interpretation. In independent primary-hepatocyte data, brightfield predictions prioritized 10 of the 11 compounds with the largest measured metabolic-activity losses among 217 held-out compounds. Measurement sufficiency therefore depends on target, predictor, context and scientific task, beyond predictive correlation alone.

bioinformatics↗

Benchmarking single-cell foundation models for aging biology

Single cell foundation models (scFMs) provide representations of cellular states, but their utility across biological questions in aging research remains unclear. We established a benchmark of cellular representations for aging research, evaluating ten general-purpose scFMs, three aging-specific models and conventional methods across five biological questions using more than 2.5 million single cell transcriptomes. Using frozen pretrained representations, Geneformer performed best among scFMs for chronological age prediction and age pseudotime concordance, although 2,000 highly variable genes achieved higher mean performance. Several scFMs captured positive molecular age shifts across three disease contexts, consistent with reported aging-associated changes. SCimilarity performed well for rare cellular state identification across out-of-distribution datasets, exceeding aging specific models and conventional baselines. At the gene level, scGPT showed the highest recovery of reference TF target interactions, including aging-related regulatory hubs. Overall, scFMs supported diverse aging analyses, but performance depended on the biological question, highlighting their utility for rare cellular state identification and regulatory analysis.

bioinformatics↗

Nsp3 Ubl1-orchestrated dephosphorylation of N protein promotes coronaviral subgenomic RNA synthesis

The coronavirus nucleocapsid (N) protein is indispensable for the viral lifecycle as part of the viral Replication-Transcription Complex together with Nsp3. Recent research demonstrated that phosphorylation of N by several host kinases intricately regulates its functions during infection. However, the mechanisms that control N dephosphorylation, and its physiological consequence, remain poorly understood. Here, we show that SARS-CoV-2 Nsp3 is a key orchestrator of N dephosphorylation by recruiting the phosphatase PP1/{gamma} via a conserved PP1-binding motif in the Ubl1 domain. Disruption of this motif abolishes N dephosphorylation and selectively impairs subgenomic RNA synthesis. Comparative interactome proteomics analysis of phospho-mimic vs. phospho-deficient N, together with functional validation, revealed that the host splicing factor SRSF1 cooperates with unphosphorylated N to promote subgenomic RNA transcription. These findings uncover an unrecognized mechanism in which Nsp3-guided N dephosphorylation by PP1/{gamma} enables coronavirus subgenomic RNA replication and highlight a potentially targetable axis for antiviral intervention.

microbiology↗

Xenon improves autism-like behaviors in mice through potentiation of PVT-CeA glutamatergic neurotransmission

Autism spectrum disorder (ASD) is a common neurodevelopmental disease with no currently effective treatments. In this study, Xenon (Xe), a noble gas used clinically as an anesthetic and a neuroprotectant, has been investigated for its potential therapeutic effects in ASD. Two genetic ASD mouse models (Mef2c mutant and Shank3-/- mice) were exposed to a low concentration of xenon (25%) mixed with oxygen (30%) and balanced with nitrogen for a single exposure of 30 min or for 10 min per day for 10 days. These Xe exposure paradigms rescued ASD-like behaviors in both male and female mice. The behavioral improvements persisted for up to 10 days following termination of the 10-day exposure paradigm. Mechanistically, Xe reduced glutamic acid decarboxylase expression in the inhibitory neurons (verified with RNAseq) of the paraventricular thalamic nucleus (PVT) and decreased GABA release during social interaction. Targeted infusion of the GABAA receptor agonist muscimol into the PVT abolished the Xe-mediated behavioral improvements. Reduced GABAergic transmission following Xe exposure increased PVT glutamatergic neuronal activity. Chemogenetic inhibition of these neurons eliminated the therapeutic effects of Xe, whereas chemogenetic activation mimicked the Xe-induced behavioral improvements. Furthermore, opto-inhibition of PVT glutamatergic projections to the central amygdala (CeA) blocked Xe-mediated behavioral improvement. Opto-activation of the PVT-CeA glutamatergic circuit reversed ASD-like behaviors. These findings demonstrate that Xe ameliorates ASD-like phenotypes in mouse models by modulating the PVT Glu-CeA circuit, supporting Xe as a novel potential therapy for ASD.

animal behavior and cognition↗

SWELL1 channel-mediated D-2HG export promotes immune evasion and metabolic fitness in IDH-mutant gliomas

Isocitrate dehydrogenase (IDH) is the most frequently mutated metabolic enzyme in human cancers. Mutant IDH produces the oncometabolite D-2-hydroxyglutarate (D-2HG), which promotes tumorigenesis in part through epigenetic alterations. Beyond its cell-autonomous effects, tumor-derived D-2HG acts as a potent immunosuppressant that establishes an immune-cold tumor microenvironment. However, the mechanism by which D-2HG is released from tumors remains largely unknown. Here, we identify the SWELL1 (LRRC8A)/LRRC8C-containing volume-regulated anion channel (VRAC) as a principal pathway for D-2HG efflux from IDH-mutant cells. Genetic deletion of SWELL1, the essential VRAC subunit, markedly reduces D-2HG release and reverses associated immunosuppression in an orthotopic mouse model of IDH-mutant glioma. Strikingly, loss of VRAC causes intracellular accumulation of D-2HG, which paradoxically limits tumor cell proliferation by driving epigenetic remodeling and mitochondrial metabolic stress. Pharmacological inhibition of VRAC with dicumarol suppresses IDH-mutant glioma growth, enhances intratumoral T cell activation, synergizes with immune checkpoint blockade, and prolongs survival in tumor-bearing mice. In human IDH-mutant lower-grade gliomas, elevated LRRC8C expression correlates with DNA hypermethylation and an immunosuppressive tumor microenvironment (TME), and predicts poor overall survival. Together, these findings establish VRAC-mediated D-2HG export as a central mechanism regulating both immune evasion and tumor cell fitness, uncovering new therapeutic opportunities across IDH-mutant cancers.

cancer biology↗

RNA self-association limits the removal of double-stranded RNA by affinity chromatography

Double-stranded RNAs are inflammatory byproducts of in vitro transcription of single-stranded RNA. Here we investigate removal of dsRNA byproducts using dsRNA affinity chromatography (dsRNA-AC) and two common mRNA molecules: 1) GFP, and 2) high dsRNA wild-type firefly luciferase (fLucWT). For GFP mRNA, dsRNA levels decreased by 2,000-fold, and mRNA recovery was high. In contrast, dsRNA levels decreased only two-fold for fLucWT, and mRNA yields were lower. Biophysical characterization revealed that fLucWT contains polydisperse higher-order structures that interfered with dsRNA-AC. Sedimentation-velocity analytical ultracentrifugation experiments demonstrated the higher-order structures were driven by mRNA concentration. Decreasing fLucWT concentrations increased the effectiveness of dsRNA-AC by reducing polydispersity. dsRNA levels were measured with ELISA, dot-blots, immuno-northern blots, and a cell-based interferon release assay, enabling comparison and cross-validation of these analytical methods. dsRNA-AC is a new chromatography modality, and this study identifies sample polydispersity as a key determinant of efficient dsRNA removal.

biochemistry↗

DiffDomain-Spectrum identifies structurally reorganized TADs from sparse aggregated single-cell Hi-C contact maps

Structurally reorganized topologically associating domains (TADs) capture condition- or cell-type-specific remodeling of chromatin contacts and are important for understanding genome organization in health and disease. Emerging single-cell Hi-C (scHi-C) technologies enable such comparisons across heterogeneous cell populations, but aggregated scHi-C contact maps remain sparse at biologically meaningful 25 kb resolution, limiting reliable TAD reorganization detection. Here we present DiffDomain-Spectrum, a spectral statistical framework for identifying reorganized TADs between conditions or cell types from aggregated raw scHi-C contact maps. It tests normalized TAD-level difference matrices without separately normalizing sparse maps or enhancing individual scHi-C contact maps. Comparison with a semicircle-law null integrates evidence across the full eigenvalue spectrum. Across multiple scHi-C platforms, DiffDomain-Spectrum balances false positive control and detection sensitivity relative to alternative bulk callers, and detects a substantially higher proportion of reference TADs as reorganized than the boundary-focused single-cell method scHiCluster. Detected TADs show coherent aggregate contact patterns and CTCF binding changes and are enriched for differentially expressed genes, supporting biological relevance. Together, these results establish DiffDomain-Spectrum as a statistically principled framework for comparative domain-level analysis of sparse aggregated scHi-C contact maps without single-cell map enhancement.

genetics↗

Isoleucine and asparagine influence the growth of staphylococcal strains in atopic dermatitis

Atopic dermatitis (AD) is a multifactorial, chronic skin disease associated with microbial factors. It is known that staphylococcal skin microbes play a role in the pathophysiology of AD, notably S. aureus. However, how staphylococcal strain variation affects disease aetiology and progression remains unclear. Using a culture-dependent approach, we analyzed the genomic and phenotypic profile of staphylococcal strains isolated from a Hong Kong children cohort (n = 70). Presence of S. aureus was positively associated with AD skin, whilst S. epidermidis and S. hominis were positively associated with healthy skin, but no overall strain type was associated with AD. In vitro experimentation revealed that there is demarcation in S. aureus strain growth, biofilm biomass formation, and metabolite production by disease severity. While isoleucine and asparagine promoted S. aureus growth, these amino acids suppressed S. hominis growth. These collective findings highlight the importance of strain-level and metabolic interactions of staphylococci in AD pathophysiology.

microbiology↗