Biology subjects

Zhou, Y.

Publications and source records attributed to Zhou, Y..

At least 19 recordsLinked to original sources

bioRxiv2026

Systemic Analysis of Patient Derived Esophageal Epithelial Organoid Model Reveals Cell State Heterogeneity and Conservation of Differentiation Hierarchy

Background and Aims: Eosinophilic esophagitis (EoE) features prominent epithelial dysregulation that persists despite resolution of eosinophilia. Interleukin-13 (IL-13) is known to be a key upstream driver of epithelial abnormalities in EoE. We sought to benchmark an IL-13 esophageal organoid model against the in vivo epithelial state in EoE at a single cell resolution, to define in the role of IL-13 in aberrant epithelial development and inflammation in EoE, and to validate the IL-13 organoid as a model system to study the epithelial changes seen in EoE. Methods: We performed scRNA-Seq on esophageal biopsies from control and EoE patients, and esophageal biopsy-derived organoids with or without IL-13. We compared cellular composition, differentiation trajectories, pathway enrichment, and differential gene expression within both systems, and assessed findings at a protein level. Results: Seven distinct epithelial cell clusters were identified and preserved in both biopsies and organoids. EoE biopsies demonstrated expansion of cycling cells, whereas IL-13-treated organoids showed shift in the composition of the suprabasal compartments. Pseudotime topology was preserved across tissues, with a shift away from terminal differentiation in both EoE biopsies and IL-13-treated organoids. IL-13 reproduced changes in the transcription of central EoE genes and the dysregulation of epithelial proliferation and differentiation pathways seen in EoE. There was broad activation of immune related pathways within both EoE biopsies and IL-13-treated organoids, however, biopsies additionally showed activation in several immune and extracellular matrix remodeling programs that IL-13 alone did not reproduce. Conclusion: IL-13-treated esophageal organoids replicate key epithelial features of EoE including dysregulated epithelial development, impaired cornification, and inflammatory signals, while preserving lineage architecture, providing a tractable platform for epithelial-targeted mechanistic and therapeutic studies.

cell biology↗

bioRxiv2026

Revealing multiscale architecture of the intact human spine using hierarchical phase contrast tomography

Background: Computed tomography (CT) and magnetic resonance imaging (MRI) provide detailed clinical assessment of the human spine; however, their millimeter-scale spatial resolution limits direct visualization of tissue microarchitecture and interfaces. Hierarchical phase-contrast tomography (HiP-CT) enables ex vivo non-destructive, micron-resolution imaging of intact human organs without exogenous contrast agents, extending anatomical assessment to spatial scales inaccessible to conventional clinical imaging. Purpose: To evaluate the capability of HiP-CT to visualize macro- to microanatomy of an intact adult human spine ex vivo. Methods: An intact spine (C1-L5) from a 62-year-old male donor without known skeletal disease was formalin-fixed and imaged by HiP-CT at the European Synchrotron. Whole-spine imaging was performed at 16.26 m isotropic voxels, with selected regions of interest imaged using 2.2 m voxels. Ex vivo MRI using clinical sequences was performed for anatomical comparison. Three-dimensional segmentation and quantitative analyses included intervertebral disc (IVD) grading, annulus fibrosus fiber tracing, and vertebral trabecular micro-morphometry. Results: HiP-CT enabled high spatial-resolution, multiscale imaging of the intact human spine, simultaneously visualizing vertebral bone and endplate, IVDs, spinal cord and meninges, nerve roots and ganglia, vasculature, ligaments, and musculature. Three-dimensional segmentation and virtual sectioning mapped neurovascular anatomy and vertebral vascular supply, without exogenous contrast enhancement, while preserving their relationships with surrounding tissues. Whole-spine images enabled quantitative analysis of annulus fibrosus fiber organization and vertebral trabecular microarchitecture, permitting the detection of focal posterolateral fiber disruption at the L4-L5 IVD and regional differences in trabecular architecture between cervical and lumbar vertebral bodies. Local tomography resolved annulus fibrosus lamellae, vertebral endplate Haversian systems, and facet joint hyaline cartilage at micron resolution. Conclusions: HiP-CT enables non-destructive, multiscale three-dimensional imaging of the intact human spine while preserving tissue relationships across spatial scales and hard-soft tissue boundaries. HiP-CT could provide an ex vivo microanatomical reference for future correlation with clinical imaging investigations of spinal disease and in the development and validation of imaging biomarkers.

bioengineering↗

bioRxiv2026

Mechanistic insights into coronavirus inhibition by a distinct base-modified adenosine analog targeting the viral polymerase

Nucleoside analog (NA) inhibitors of viral polymerases are a chemically diverse and prominent class of antivirals, with most agents bearing sugar modifications to induce chain termination. Compounds with a modified base yet natural ribose are comparatively rare and typically incorporated to act as virus mutagens, raising significant safety concerns. How nucleobase modifications interfere with polymerization and the molecular basis of this effect remain poorly understood. We here define the mechanism of 6-ethyl-modified 7-deazaadenosine (EDA), a recently identified coronavirus (CoV) inhibitor that does not induce virus mutagenesis. Its strong activity spans across multiple CoVs and cell models and is dictated by the 6-ethyl substituent, with poor tolerance for smaller, larger or heteroatom-containing substituents. At the level of SARS-CoV-2 RNA-dependent RNA polymerase (RdRp), EDA-triphosphate incorporates as a mimic of ATP but not other NTPs, inducing immediate stalling but also excision by the viral 3'-to-5' exonuclease. While EDA incorporation prevents extension with a second EDA residue, the stalling of natural NTP incorporation is transient and still allows the formation of longer products. A similar phenomenon is observed with template-embedded EDA. Cryo-EM analysis with SARS-CoV-2 RdRp revealed that 3'-terminal EDA is accommodated without distortion of the template:primer duplex, but its 6-ethyl group induces rearrangements in the NTP binding pocket that prevent stable binding of the incoming nucleotide. The mechanistic findings were validated through antiviral studies with SARS-CoV-2 mutants bearing core substitutions in the RdRp or exonuclease. Together, these findings position EDA as a mechanistically distinct base-modified NA prototype that has relevance beyond coronaviruses and underscores the ever-expanding versatility of NA-based polymerase inhibitors.

microbiology↗

bioRxiv2026

Disease-associated NK-cell state remodeling reveals transcriptional profiles predictive of clinical phenotypes

Natural killer (NK) cells adapt their cellular states to diverse tissue and inflammatory environments, yet how this plasticity manifests across pathological contexts and relates to patient-level disease phenotypes remains poorly defined. Here we established the Human NK-cell Atlas (HNKA) from over 1 million NK cells, including samples from 1,632 donors spanning 50 diseases. Within a shared NK-cell state architecture, analyses of state abundance and matched-reference exceedance distinguished disease-biased redistribution from transcriptional displacement. Fine-grained analyses localized disease-associated remodeling to specific NK-cell states, including CD56dim NK ISG15 in infection and autoimmunity and CD56bright NK ITM2C in tumors. These patterns were accompanied by recurrent interferon responses and state-specific regulatory activity. Cytokine perturbations recapitulated key transcriptional features of disease-associated NK-cell states. We developed NKceiver, a model based on state-specific NK-cell expression profiles for patient-level prediction. It distinguished 18 diseases and predicted COVID-19 severity and response to immune checkpoint inhibitors, with predictive performance retained in unseen patients and studies. Collectively, our results reveal that disease-associated remodeling within the diverse NK-cell state repertoire resolved by HNKA is biologically interpretable and clinically informative, supporting disease discrimination and prediction of clinical phenotypes.

immunology↗

bioRxiv2026

Early-life core microbiota are associated with postlarval survival of Penaeus vannamei: A meta-analysis

Larviculture is critical to the production of Penaeus vannamei, the world's leading farmed shrimp species, but remains constrained by erratic postlarval survival. Although early-life microbiome establishment is increasingly recognized as essential for larval health and survival, microbiome-based hatchery interventions are hindered by limited understanding of larval core microbiota. Here, we synthesized publicly available and self-generated 16S rRNA gene amplicon datasets of larval and rearing-water microbiota from 13 studies encompassing seven major producing regions worldwide to characterize shrimp larval core microbiota, their assembly processes, and their associations with larval survival. Although larval prokaryotic communities exhibited stronger geographic variation than developmental-stage succession, a conserved set of dominant bacterial families, including Roseobacteraceae, Vibrionaceae, Flavobacteriaceae, Moraxellaceae, and Pseudoalteromonadaceae, consistently prevailed across developmental stages and regions. By integrating occupancy, persistence, and ecological network centrality analyses, we demonstrated that common, temporal, and ecological core microbiota differ substantially in composition, diversity, stage specificity, and ecological roles in network stability. Compared with non-core taxa, core taxa were generally assembled more deterministically, irrespective of core category, suggesting stronger host selection and/or more rapid dispersal during microbiome establishment. Core microbiota also generally showed stronger associations with postlarval survival than total communities or non-core taxa, although contrasting survival associations among core members indicated that core microbiota are not ecologically homogeneous. Our work provides the first systematic categorization and characterization of larval core microbiota throughout the shrimp larviculture cycle, offering new insights into the ecological significance of core microbiota and identifying potential universal targets for microbiome-based intervention in shrimp larviculture.

microbiology↗

bioRxiv2026

A genomic foundation model for interpreting human genetic diversity

Interpreting human genomes requires models that recognize shared biological functions while accounting for variation underlying traits, disease susceptibility and adaptation. Here we present hEVO, a genomic foundation model trained on 4.784 billion distinct haplotype sequences reconstructed from whole genome sequencing (WGS) data for 63,809 individuals selected from 550,237 samples across eight cohorts. Pretraining integrates shared sequence features and naturally occurring allelic differences without clinical or functional labels. Against representatives of the Evo 2, NT, GPN and other genomic model families, hEVO ranked first in 18 of 19 primary comparisons spanning functional annotation, variant interpretation and human evolution. Its pretrained allele scores generalized across all six complementary variant benchmarks without task-specific training, achieving the highest performance across clinical pathogenicity, fine-mapped causal variants and experimentally measured regulatory effects. Retrospective ClinVar reclassification further demonstrated improved identification of pathogenic classifications later downgraded, supporting reassessment of earlier clinical interpretations. Predictive strengths extended to ancestry inference, human accelerated sequences and preference for reported selected alleles. This breadth was achieved with substantially fewer parameters than billion-parameter comparators and low inference overhead in the evaluated workloads. These findings establish human haplotype diversity as a source of transferable biological information for interpreting both the disruption of genome function and the variation retained during human evolution.

genomics↗

bioRxiv2026

ClonoDeconv: reference-based α - β paired recurrent clonotype proportion estimation from bulk-TCR sequencing

T cell receptor (TCR) sequencing is crucial when studying antigen-specific T cell responses and clonal dynamics. A key objective of TCR repertoire analysis is to identify recurring clonotypes across timepoints or different disease states, providing insight into the evolution of immune response. Bulk-TCR sequencing enables high-throughput profiling of TCR and {beta} sequences but lacks pairing information, while single cell TCR sequencing (scTCR-seq) retains pairing information but is limited by sensitivity, throughput, and costs. We present ClonoDeconv, a computational framework to deconvolute paired TCR {beta} ; clonotype frequency from bulk TCR sequencing experiments using a paired scTCR-seq reference. ClonoDeconv robustly estimated shared clonotype abundances from 5' RACE bulk-TCR datasets using a scTCR-seq reference from the same donor. Applied to longitudinal samples, ClonoDeonv successfully captured the expansion and contraction of rare virus-specific clones across timepoints. Taken together, ClonoDeconv provides a cost-effective and scalable approach for studying the longitudinal T-cell clonal dynamics.

bioinformatics↗

bioRxiv2026

Development of a nanomedicine approach to improve the therapeutic index of bexarotene.

Bexarotene (BEX), a retinoid X receptor (RXR) agonist, has demonstrated therapeutic potential in oncology, neurodegenerative diseases and inflammatory conditions, including multiple sclerosis (MS). However, its broader clinical application is limited by poor aqueous solubility, low bioavailability, and dose-limiting adverse effects, most notably hypertriglyceridaemia. In this study, we investigated whether conjugation of BEX to dextrin, a biodegradable polysaccharide, could improve its physicochemical properties and therapeutic index. A dextrin-BEX conjugate was synthesised using succinoylated dextrin (30 mol%) and characterised by gel permeation chromatography (GPC), Fourier-transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (1H-NMR) and dynamic light scattering (DLS). The effects of conjugation on solubility, aggregation behaviour and biological activity were evaluated using in vitro cytotoxicity assays in leukaemia, liver and fibroblast cell lines, alongside measurements of intracellular triglyceride levels. The impact on lipid metabolism and toxicity was further assessed in an in vivo murine model of hyperlipidaemia. Dextrin conjugation significantly increased the aqueous solubility of BEX (from <0.004 mg/mL to 9.88 mg/mL) and led to the formation of nanoscale aggregates in solution. This was associated with a marked increase in in vitro potency, with IC50 values reduced by up to 14-fold across multiple cell lines. However, the increased cytotoxicity was not selective for cancer cells and was also observed in normal fibroblast and hepatic cell models. The dextrin-BEX conjugate did not induce intracellular triglyceride accumulation in vitro. In vivo, dextrin conjugation did not mitigate BEX-associated lipid dysregulation, while serum triglyceride levels and markers of liver injury remained unchanged. However, although free BEX led to a significant increase in liver weight after 14 days, the dextrin-BEX conjugate did not produce a statistically significant effect. In conclusion, dextrin conjugation markedly improves the solubility and in vitro potency of BEX but does not enhance its selectivity or reduce its metabolic toxicity in vivo. These findings suggest that while polymer conjugation is an effective strategy for addressing physicochemical limitations, it is insufficient to overcome the inherent dyslipidaemia associated with systemic RXR activation. Future strategies should focus on integrating targeting and controlled release mechanisms, alongside approaches that address the underlying pharmacological drivers of lipid dysregulation.

pharmacology and toxicology↗

bioRxiv2026

NE52-QQ57 attenuates post-ischemia protein phosphorylation in the mouse brain

Introduction: Cerebral ischemia induces a reduction in brain pH. GPR4, a proton-sensing G protein-coupled receptor is highly expressed in vascular endothelial cells. Pharmacological inhibition of GPR4 with NE52-QQ57 (NEQQ) reduces ischemia-induced blood-brain barrier (BBB) disruption and brain injury. To facilitate targeting GPR4 in vivo, it is important to better define the effect of NEQQ on post-ischemia signaling and the pharmacokinetics of NEQQ in vivo. Methods: We performed biochemical analysis following transient middle cerebral artery occlusion (tMCAO). We used Liquid Chromatography-Mass spectrometry (LC-MS/MS) to quantify the concentration of NEQQ in serum, brain, and peripheral tissues. Results: NEQQ administration decreased the phosphorylation of PKA substrates, PKC substrates, ERK1/2, and CREB. LC-MS/MS analysis detected NEQQ in both ipsilateral and contralateral hemisphere of the brain at 5 h and 24 h after reperfusion, demonstrating that NEQQ crosses the BBB. In peripheral tissues, NEQQ exhibited highest level in kidney and lowest in the heart. In sham controls, average serum concentrations were ~4 and 0.9 g/g at 5 and 24 h, respectively. Following tMCAO, ipsilateral brain exhibited higher levels as compared to the contralateral side at 5 h while the difference diminished at 24 h. Conclusions: NEQQ attenuated the ischemia-induced activation of multiple signaling pathways. NEQQ exhibited broad distribution in peripheral organs, and its brain level was sufficient for GPR4 inhibition at 24 h after injection. These findings support the use of NEQQ as a pharmacological inhibitor of GPR4-mediated signaling following ischemic stroke.

neuroscience↗

bioRxiv2026

Impacts of different SETD1A mutations and genetic backgrounds on human induced pluripotent stem cell-derived hippocampal neurons

Abstract Human induced pluripotent stem cells (hiPSCs) provide a translational platform to interrogate the impact of genetic risk factors for various disorders on human biology. It has been a common practice to engineer premature stop codons to model predicted loss-of-function mutations using isogenic hiPSCs, yet effects of mutation position for the same gene and genetic background have been rarely tested systematically and at multiple levels for comparison to those of patient-specific mutations. Ultra-rare, heterozygous, and predicted loss-of-function mutations in the SETD1A gene, which encodes a H3K4 methyltransferase, are highly penetrant genetic risk factors for schizophrenia. Here, we generated a large panel of isogenic heterozygous SETD1A mutant hiPSC lines, including premature stop-codon mutations in one early exon and one late exon in five genetic backgrounds and two patient-specific mutations, to gain insight into molecular, cellular, and functional changes in a disease-relevant and highly pure population of human hippocampal dentate granule cell-like neurons. Our multi-level analyses showed that different SETD1A mutations lead to divergent molecular and cellular phenotypes related to synapses, but convergent neuronal network deficits, while the genetic background influences gene expression with no substantial effects at cellular and network levels. Mechanistic analysis confirmed the early exon patient mutation as loss-of-function, but revealed that the predicted loss-of-function patient mutation in the late exon is likely gain-of-function. Consequently, while all mutations decreased global H3K4me3 levels, deficits were only partially rescued by inhibiting H3K4 demethylase LSD1 for early exon mutations, but not for late exon mutations. Together, these results suggest that highly penetrant mutations can lead to similar cellular and functional phenotypes across different genetic backgrounds, whereas different premature stop-codon mutations could have contrasting impacts due to distinct mechanisms. Our findings have practical implications for applying genome-editing in hiPSCs to model disorders, highlight the value of modeling patient-specific mutations and testing multiple mutations, and suggest the need for tailored mutation-dependent therapeutic strategies.

neuroscience↗

bioRxiv2026

Pharmacokinetic properties of Ogerin and its regulation of post-ischemia signaling in mice

Ogerin, a positive regulator of GPR68, reduces infarct volume and attenuates blood-brain barrier (BBB) leakage post transient middle cerebral artery occlusion (tMCAO). These data support the potential use of Ogerin for ischemic protection. For therapeutic interventions, tissue distribution, kinetics, and brain penetration are important characteristics for a compound. For these reasons, we performed liquid chromatography-mass spectrometry (LC-MS) analysis of Ogerin in mice. At 3 hours following intraperitoneal (IP) injection, liver exhibited highest level of Ogerin among all major organs assessed. We further analyzed time-dependent changes in Ogerin concentration in serum following intravenous delivery. Brain Ogerin level was ~140 ng/g at 2 hour and ~0.06ng/g at 24 hours. The brain-to-serum ratio of Ogerin was ~0.6 at 5 hr. To determine the effect of Ogerin on signaling, we collected samples 24 hours after tMCAO with or without Ogerin delivered and performed Western blotting. Consistent with the diminished level of Ogerin in brain at 24 hour, tMCAO increased similar changes in phosphorylation of PKA substrates and PKC substrates in vehicle- and Ogerin-treated groups. The pharmacokinetic data suggests that Ogerin is effective mainly during acute hours after injection. This finding generates important insights on the design of effective protocol for Ogerin delivery to potentiate GPR68 function in vivo.

neuroscience↗

bioRxiv2026

Genetic accessibility, not superior fitness, determines which anti-HBs antibody escape variants are selected in patients

Background and Aims: Genetic diversity within the hepatitis B virus (HBV) surface antigen (HBsAg) drives the emergence of immune escape variants, but studying this diversity in vivo has been limited by the difficulty of establishing infection from patient isolates. We aimed to perform unbiased in vivo screening of variants in the HBs antigenic loop for antibody escape and fitness, using synthetic DNA launch of HBV in human hepatocyte chimeric mice. Approach and Results: Direct intrahepatic injection (IHI) of barcoded, recombinant cccDNA established infection from up to 32,000 independent launch events of a genotype A strain and successfully launched clinical consensus sequences across the major genotypes. Using IHI, we performed deep mutational scanning of 4,608 codon variants across the HBs antigenic loop. Under control antibody treatment, diverse variants expanded, revealing differences in variant fitness in the absence of adaptive immune pressure. Anti-HBs monoclonal antibody treatment suppressed wild-type viremia while permitting breakthrough of resistant variants from the library. Sequencing identified strong enrichment for substitutions at G145 (G145Q, G145H, G145R). Notably, G145Q, rather than the clinically dominant G145R, showed the greatest fitness advantage, indicating that G145R's clinical prevalence does not reflect superior intrinsic fitness. Conclusions: Unbiased in vivo screening reveals that clinically observed HBV escape mutations reflect which substitutions are genetically accessible by single nucleotide change and compatible with the overlapping polymerase reading frame, rather than which confer optimal fitness. This approach establishes a platform for high-resolution mapping of viral variant fitness under antiviral selection pressure.

microbiology↗

bioRxiv2026

The cleaved C-terminal domain of GmERS1-1 modulates cell cycle via GmACR1

Ethylene signaling orchestrates plant development and stress adaptation, yet how post-translational modifications of its receptors coordinate growth regulation remains unresolved. Here, we uncover a proteolytic processing mechanism of the soybean ethylene receptor GmERS1-1 that directly gates cell cycle progression. The GmERS1-1 mutants exhibit elevated yield under field conditions, whereas overexpression suppresses growth and hypersensitizes plants to ethylene. Ethylene triggers nuclear translocation of C-terminal domain (GmERS1-1-CEND), which is indispensable for receptor function. Mechanistically, GmERS1-1-CEND scaffolds a trimeric complex with GmACR1 and GmCDK7, enforcing G2/M phase arrest, thereby decoupling cell division from canonical ethylene transcriptional responses. Strikingly, ethylene-induced cell cycle blockade during apple fruit maturation mirrors this pathway, suggesting deep conservation across angiosperms. Our work defines a receptor processing-dependent signaling axis that directly interlinks phytohormone perception with cell cycle control, proposing tunable targets (e.g., GmERS1-1 cleavage efficiency) for engineering crop architecture and productivity.

plant biology↗

bioRxiv2026

Lipid acyl chain remodeling governs KRAS nanoclustering and oncogenic functions through membrane composition control

KRAS signaling is spatially organized within the dynamic proteolipid nanoclusters on the plasma membrane (PM) that selectively concentrate anionic phospholipids, yet the molecular determinants governing this lipid sorting remain incompletely defined. Here we identify phospholipid acyl chain composition as a critical regulator of KRAS spatial organization and signal output. Using genetic and pharmacological perturbation of lysophosphatidylcholine acyltransferase 3 (LPCAT3), a key enzyme that incorporates polyunsaturated fatty acids into phospholipids, we demonstrate that remodeling of membrane acyl chain unsaturation alters the phosphatidylserine (PS) lipidome without changing total PS abundance. Loss of LPCAT3 depletes polyunsaturated PS species, disrupts KRAS PM association and nanoclustering, and attenuates downstream MAPK signaling and oncogenic activity across multiple KRAS mutant contexts. Acute restoration of polyunsaturated, but not saturated, lipids rescue KRAS nanoclustering, establishing a direct requirement for lipid unsaturation in sustaining signaling-competent assemblies. Mechanistically, these findings define membrane acyl chain composition as a determinant of proteolipid organization that encodes KRAS signaling capacity. Consistent with this model, LPCAT3 inhibition selectively impairs KRAS-dependent proliferation and sensitizes tumor cells to direct KRAS inhibition. Together, this work uncovers lipid acyl chain remodeling as a fundamental regulator of membrane-associated signaling and identifies membrane composition as an exploitable vulnerability in oncogenic KRAS systems.

cancer biology↗

bioRxiv2026

Comparative proteomic quantification reveals novel longevity regulators

Proteomics is a powerful tool for profiling the protein landscape underlying cellular and physiological processes. Advances in mass spectrometry-based methods, such as tandem-mass-tags (TMT) isobaric labeling-based proteomics at both MS2 and MS3, label-free quantification (LFQ) with data-dependent-acquisition (DDA) or data-independent acquisition (DIA)-based proteomics, and stable isotope labeling with amino acid (SILAC) spike-in-assisted proteomics, enable quantitative proteome comparisons across biological conditions. These five quantitative proteomic methods offer distinct advantages in coverage, throughput, and quantitative reproducibility. Here, we treated them as orthogonal approaches, retaining protein candidates with significant, consistent-direction changes supported across multiple independently instrumented methods to identify high-confidence protein-level changes associated with longevity. Insulin/insulin-like growth factor signaling (IIS) is a highly conserved longevity regulatory pathway from Caenorhabditis elegans to humans. By quantitatively profiling IIS mutants in C. elegans and performing genetic screening, we obtained a systems-view of proteomic changes linked to longevity and identified new longevity regulators. This systematic cross-method comparison also serves as a valuable resource for guiding the selection of quantitative proteomics approaches.

molecular biology↗

bioRxiv2026

Ambient-Condition Visualization of Metalloenzyme Reactive Intermediates Enabled by the SHINERS Paradigm

Reactive metal-oxygen intermediates are central to metalloenzyme catalysis, yet their low populations and short lifetimes make vibrational characterization under aqueous reaction conditions challenging. Here, we establish shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) as a powerful vibrational approach for visualizing reaction-associated metal-ligand signatures of reactive metalloenzyme states. Across the heme and non-heme iron enzymes TauD, VioC, CYP119, and TqaLNc, isotope-sensitive features provide vibrational information on reactive coordination states. In TauD and VioC, isotope-sensitive features provide vibrational characterization of Fe(IV)=O intermediates. In CYP119, an isotope-sensitive Fe(IV)=O vibration is assigned to P450 Compound I generated by m-CPBA, including under lauric-acid turnover conditions. Most notably, in TqaLNc, combined 18O- and 15N-sensitive vibrational responses support formation of the proposed (R)HN-Fe(IV)=O coordination state and the dynamic-coordination mechanism underlying selective C-N bond formation. These results demonstrate that SHINERS can serve as a powerful technique for the in situ vibrational visualization of reactive intermediates and their coordination states in metalloenzyme catalysis.

biochemistry↗

bioRxiv2026

NexuST: A Hierarchical Foundation Model for Spatial Transcriptomics

Spatial transcriptomics captures molecular states within cells and their organisation in tissue. However, integrating fine-grained gene information with spatial context at scale remains challenging for existing foundation models. Here we present NexuST, a hierarchical foundation model that repeatedly interleaves gene-level molecular modelling with cell-level spatial modelling, allowing the two levels to refine one another during end-to-end pretraining. For pretraining, we curated HumanST-46M, comprising 45.7 million human cells from 72 datasets across 11 organs and three imaging-based platforms. Across four held-out datasets totalling approximately 2.6 million cells, NexuST achieved state-of-the-art or competitive performance in cell-type annotation, region prediction, gene recovery and neighbourhood-composition prediction. We find that cell-intrinsic expression remains informative even for spatial tasks, as shown by an expression-only PCA baseline, while NexuST shows particularly strong gains where spatial context is essential. Overall, NexuST establishes a hierarchical framework that can serve as a general backbone for future spatial transcriptomics foundation models.

bioinformatics↗

bioRxiv2026

Unified modeling of mutation-induced protein stability responses with OmegaTherm

Accurate prediction of mutation-induced protein stability responses, including changes in folding free energy and melting temperature, is critical for protein engineering. Existing models represent these related but non-equivalent measurements separately and often focus on single mutations. Here we present OmegaTherm, a sequence-based framework that jointly learns both stability responses for single and multiple mutations. OmegaTherm introduces a shared protein language model to capture transferable mutation context, measurement-specific encoders to preserve measurement identity, and paired-measurement-informed distillation to learn complementary knowledge from heterogeneous data. An antisymmetric prediction architecture further enforces physical consistency between forward and reverse mutations. Across independent benchmarks, OmegaTherm achieves state-of-the-art performance in quantitative prediction, mutation classification and protein-level ranking. Beyond benchmark prediction, OmegaTherm-derived stability landscapes correlate strongly with fitness landscapes from deep mutational scanning, enrich favorable variants and reveal function-associated mutation-sensitive regions. These results establish unified representation learning as an effective strategy for integrating related but non-equivalent biochemical measurements.

bioinformatics↗