Biology subjects

Chen, J.

Publications and source records attributed to Chen, J..

At least 289 records · Page 16Linked to original sources

bioRxiv2026

Genetics-informed bidirectional mapping of glycemic traits and brain phenotypes

Dysglycaemia is linked to brain atrophy, white-matter disruption and dementia risk, yet the directionality and mechanisms of glycemic-brain coupling remain unclear. Here we integrate large-scale GWAS of fasting glucose, fasting insulin, 2-hour glucose, HbA1c and type 2 diabetes with multimodal brain imaging phenotypes and major brain disorders using bidirectional two-sample Mendelian randomization. Across 4,040 tests, we identify 54 glycaemia and brain causal associations (FDR P < 0.05) and uncover a timescale-dependent hierarchy: short-term glycemic traits map to distributed macrostructure and functional-network, whereas long-term glycemic burden preferentially implicates long-range association and commissural white-matter pathways with focal prefrontal-paracentral vulnerability. Reverse analyses reveal 44 brain IDPs and glycaemia effects. Multi-trait Bayesian colocalization and tissue/cell-type eQTL integration nominate shared causal loci enriched in glial and neurovascular pathways. Individual-level UK Biobank analyses validated glycaemia-associated brain structural alterations and non-linear risk patterns for incident outcomes. Together, our results provide a genetically anchored atlas of bidirectional glycemic-neural relationships, linking metabolic dysregulation to multiscale brain vulnerability and disorder risk.

neuroscience↗

bioRxiv2026

MR-μScope: a multi-scale and simultaneous MRI-miniaturized microscopy system for elucidating neurovascular coupling

Blood Oxygen Level Dependent functional MRI (BOLD-fMRI) revolutionized non-invasive brain mapping, yet the physiological origins of its signal, linking microscopic neurovascular activity to macroscopic hemodynamics, remain elusive. To bridge this gap, we developed MR-Scope: a simultaneous and multimodal platform that integrates preclinic high-field MRI (9.4T) and miniaturized fluorescence microscopy (Miniscope). Our system contains an MR-compatible Miniscope with electromagnetic shielding, a customized radiofrequency coil with a central optical window, and an adjustable animal cradle, enabling artifact-free acquisition of whole-brain fMRI alongside microscopic vascular dynamics. Phantom validation confirmed negligible cross-modal interference (fMRI SNR [≥] 15 dB; optical SNR [≥] 26 dB). MR-Scope captured stimulus-evoked microvascular dilation and blood flow velocity changes in the somatosensory cortex concurrent with BOLD signals, revealing vessel-size-dependent neurovascular coupling. MR-Scope provides an effective solution for deciphering multi-scale neurovascular interactions and offers unique potential for advancing research into brain function and disease mechanisms involving vascular pathology.

bioengineering↗

bioRxiv2026

Diverse bacterial pattern recognition receptors sense the conserved phage proteome

Recognition of foreign molecules inside cells is critical for immunity across all domains of life. Proteins of the STAND NTPase superfamily1,2, including eukaryotic NOD-like receptors (NLRs), play a central role in this process3,4. In bacteria and archaea, although several STAND families sense phage proteins5-9, their functional diversity remains largely unexplored. We conducted a systematic phylogenetic analysis of prokaryotic STAND NTPases and identified at least 90 structurally distinct families associated with antiviral defense. We first show that the uncharacterized Avs7 family recognizes the major capsid protein (MCP) of tailed phages. Three cryo-EM structures of Salmonella enterica Avs7 reveal an asymmetric, butterfly-shaped tetramer that assembles stepwise via large, MCP-induced conformational changes, incorporating bacterial elongation factor Tu (EF-Tu) as a structural component that enhances defense. Using genetic screens with a library of 687 phage genes, we further show that 13 additional STAND families sense 13 conserved phage proteins, encompassing most of the core structural and replicative components of tailed phages. These include two distinct MCP-sensing families--Avs8 (PD-{lambda}-4) and Avs10 (Erebus/Hypnos/bNACHT64)--and 11 others (Avs11-21) recognizing the portal, portal adaptor, tail nozzle, head-tail connector, tail terminator, tail tube protein, tail assembly chaperone, tape measure protein, DNA polymerase, helicase/RecA-type ATPase, and single-stranded DNA annealing protein, respectively. Together, our findings highlight structurebased pattern recognition and host factor repurposing as fundamental strategies of bacterial immunity.

molecular biology↗

bioRxiv2026

Trait anxiety is associated with idiosyncratic neural event boundaries during naturalistic movie-watching

Anxiety is associated with altered patterns of attention to images and objects, but how it influences the perception of continuous experiences remains underexplored. Here, we examined whether trait anxiety is associated with differences in how the brain segments continuous experience into events. Using a large-scale open-access dataset and data-driven methods to detect neural event boundaries, we compared neural event segmentation between healthy adults with high (N=60) and low trait-level anxiety (N=60) as they viewed a short suspenseful film. While the cortical temporal hierarchy was preserved across groups, high-anxiety individuals had more idiosyncratic event boundaries, exhibiting reduced alignment to both low-anxiety individuals and one another. This divergence was most pronounced in the dorsal attention and frontoparietal control networks, suggesting that trait anxiety is associated with idiosyncratic temporal organization in systems involved in attentional control. Furthermore, boundary variability in high-anxiety participants was greater during moments rated as more anxiety-provoking by a large language model, controlling for arousal, valence, and low-level visual features. Together, these findings suggest that anxious individuals organize continuous experience in a more individualized manner. More broadly, they offer a neurocomputational framework for investigating how trait-level variability interacts with narrative content to shape naturalistic event perception.

neuroscience↗

bioRxiv2026

Glucose is a ligand-like trigger for secretion of postprandial GLP-1

Glucagon-like peptide 1 (GLP-1) is secreted from the intestinal L cells in a glucose-dependent manner. However, the mechanism underlying how glucose stimulates the secretion remains unclear. Here, we found that glucose at postprandial concentrations near the Km of GK for glucose ([~]10 mM), as well as nonmetabolizable glucose analogs, triggers GLP-1 secretion by intestinal L cells through directly binding to glucokinase (GK), without increasing intracellular ATP levels. We also show that in postprandially high glucose, glucose-bound GK interacts and inhibits KATP, as assessed by immunoprecipitation and FRET-FLIM analyses, as well as patch clamping. In addition, we have utilized GK mutants identified in diabetics, demonstrating that those mutants defective in binding to glucose impair GLP-1 secretion in however high glucose, whereas mutants constitutively bound to glucose with defects in catalysis, promote GLP-1 secretion even in low glucose. Furthermore, the KATP mutant unable to bind to GK blocks GLP-1 secretion in high glucose. We have also provided evidence showing that sodium-glucose cotransporter 1 (SGLT1) plays an important role in the basal secretion of GLP-1, but not in high glucose. We have thus revealed that glucose the molecule itself and GK act as a ligand and the receptor, respectively, to induce GLP-1 secretion in response to high glucose, providing new therapeutic avenues targeting metabolic diseases.

biochemistry↗

bioRxiv2026

Cryo-EM reveals the structural basis of subtype-specific, noncompetitive inhibition of the human P2X3 receptor

P2X receptors are ATP-gated cation channels, and the P2X3 subtype plays crucial roles in peripheral sensory neurons, including in chronic pain and chronic cough. Accordingly, P2X3 has attracted substantial interest as a therapeutic target. Gefapixant, a negative allosteric modulator (NAM) of P2X3, has been approved in some countries for the treatment of chronic cough; however, its limited selectivity for P2X3 homomers over P2X2/P2X3 heteromers is associated with taste disturbance as a prominent adverse effect. These limitations have motivated the development of next-generation NAMs with improved subtype selectivity, but their subtype-specific allosteric inhibition mechanisms are unclear. Here, we report the cryo-EM structure of the human P2X3 receptor in complex with ATP and the P2X3-selective next-generation NAM sivopixant, an investigational drug. Sivopixant binds to an allosteric site at the portal of the central pocket in the extracellular domain, and structure-based mutational analysis by electrophysiology identifies key residues required for sivopixant-dependent inhibition of human P2X3. Comparisons with P2X structures from other subtypes, together with gain-of-function mutants, define a structural basis for subtype-selective allosteric inhibition of the P2X3 receptor. Furthermore, structural comparisons with apo and ATP-bound open states of P2X3 receptors, together with molecular dynamics simulations, revealed that sivopixant expands the upper body domain to suppress the lower-body movements required for channel activation, thereby preventing channel opening even in the presence of ATP.

biophysics↗

bioRxiv2025

Fast and slow architectures of cortical dynamics in human brain

The human brain operates across a vast temporal range, from fast perception and action to slow physiological regulation. The capacity has attributed to a unitary cortical gradient of intrinsic timescales, yet such a unidimensional model cannot explain how local circuits simulateously support both rapid external behavior and slow internal body-coupled dynamics. Using SPLIT (spectral piecewise-linear inference of timescales) on a large-scale intracranial stereo-electroencephalography (8,619 contacts, 185 individuals), we identified dissociable fast (~10-100 Hz) and slow (~1-10 Hz) temporal components. Only the fast-component timescales followed the canonical sensorimotor-to-association cortical hierarchy. Slow-component timescales showed no hierarchical gradient, but were instead covaried with heart rate and enriched at site with heart-related neural responses. This dual temporal architecture persisted across wakefulness, rest, sleep, and anesthesia, challenging the unitary view of brain timescales and revealing an intrinsic bipartite organization that is associated with cortical hierarchy or neurophysiology.

neuroscience↗

bioRxiv2025

Stabilising selection and ecological trade-offs underpin coexistence in a tropical flora

Tropical forests harbour the majority of global plant biodiversity1,2, yet the genomic mechanisms governing the assembly and maintenance of these communities remain poorly understood. Here, we assembled draft genomes for 499 angiosperm species from a lowland rainforest in Singapore, representing 67% of its flora, and integrated these with plant traits and comprehensive forest census data. Across the community, most gene families evolve under stabilising selection, with copy numbers maintained near long-term optima that differ among ecological strategies. These niche-associated genomic attractor states provide a mechanism for convergent adaptation and species coexistence. Modelling stabilising selection also identified a strong trade-off between defence and growth, indicating that pathogen pressure constrains developmental diversification. Consistent with this, species-specific genome space was enriched for resistance genes and transposable elements. In contrast, genomic processes structuring present-day plant community composition differ from those driving deep-time convergence. Genomic comparisons across forest types revealed stronger selection on defence-related pathways in old-growth primary forests and on growth-related processes in regenerating secondary forests, while community-level genomic profiles showed expansions in gene families associated with rapid responses to environmental fluctuations. Stabilising selection therefore links population-level adaptation3,4 with long-term species diversification in the tropics. Niche similarity promotes long-term coexistence, whereas local community structure is shaped by more rapid ecological filtering driven by environmental change. Taken together, these two distinct evolutionary layers provide a genomic framework for understanding how hyperdiverse rainforest floras arise and persist.

genomics↗

bioRxiv2025

SF3A2 deacetylation at lysin 10 mitigates myocardial pathological remodeling by reprogramming cardiomyocyte metabolism

BackgroundDysregulation of splicing factor-mediated pre-mRNA alternative splicing (AS) underlies the progression of complex diseases, but the specific involvement of AS in myocardial pathological remodeling remains unclear. This study aimed to elucidate the role of splicing factor 3A, subunit 2 (SF3A2) in the development of myocardial pathological remodeling by regulating AS and its effect on metabolic reprogramming. MethodsWe evaluated the function and mechanism of SF3A2 in myocardial pathological remodeling using murine models induced by myocardial infarction (MI) and isoproterenol. The gain- and loss-of-function models (AAV9-cTNT delivery-mediated knock-in and lentivirus-mediated knockdown) combined with acetylomics, metabolomics, lipidomics, 13C-glucose tracing and immunoprecipitation coupled with liquid chromatography-tandem mass spectrometry (IP-MS) analyses were used to demonstrate the mechanism of SIRT7-mediated SF3A2 deacetylation at lysin 10 (K10). Unbiased RNA sequencing and AS analysis were conducted to identify the downstream effector of SF3A2. ResultsSF3A2 acetylation at lysine 10 was upregulated in cardiomyocytes in response to myocardial pathological remodeling. Functionally, the knock-in of a deacetylation-mimetic SF3A2 (K10R) mutant attenuated myocardial hypertrophy, fibrosis, and improved heart function. These phenotypes were accompanied by a redirection of glucose flux from anaerobic glycolysis to the TCA cycle, along with a promotion of fatty acid {beta}-oxidation by inhibiting CD36 translocation and decreasing ACLY activity. Mechanistically, SF3A2 mitigated metabolic reprogramming and mitochondrial dysfunction by regulating Nnt AS, a process involving the SF3A2-interacting protein Ddx1. IP-MS further identified SIRT7 as the deacetylase for SF3A2, which was found to be activated by ginsenoside Rg1 in a high-throughput screen, leading to improved heart function. ConclusionsOverall, our findings establish the SIRT7-SF3A2-Nnt axis as a critical regulator in metabolic reprogramming to delay pathological myocardial remodeling. Promoting SF3A2 deacetylation, mediated by AAV9 delivery or pharmacological activation of SIRT7, improved heart function, suggesting its potential as a therapeutic target for pathological myocardial remodeling.

molecular biology↗

bioRxiv2025

Modeling Individualized Adolescent Mental Health through a Multifactorial Causal Framework to Identify Potential Intervention Strategies

Associations between psychopathology, cognition, and personality are well established. However, these associations unfold within a broader developmental context shaped by brain maturation, environmental exposures and pubertal transitions, whose influences remain poorly understood. Here, we characterized how cognition and personality relate to adolescent mental health within this developmental context. Using data from the Adolescent Brain Cognitive Development Study (N = 4501), we simultaneously modeled 16610 brain structural, environmental, and pubertal measures to examine 165 behavioral pairs comprising cognitive and personality traits with mental health symptoms. Using an integrated analytic pipeline combining multifactorial mediation and longitudinal interaction-inclusive models, we evaluated whether developmental changes in cognition and personality relate to mental health at the individual level, and whether these associations vary across brain, environmental, and pubertal profiles. Most behavioral pairs showing significant mediation effects likewise exhibited significant longitudinal effects. These pairs were primarily influenced by neurobiological and environmental measures; cortical frontal and temporal regions relevant for cognitive control and emotional regulation as well as family and lifestyle contexts were most prominently implicated. Finally, after accounting for inter-individual heterogeneity, personality traits emerged as the main behavior associated with mental health. These findings characterize developmental associations linking cognition and personality with adolescent mental health, and show that these associations vary across brain, environmental, and pubertal profiles. The study advances understanding of behavioral development and provides a framework for identifying targets for psychopathology prevention.

neuroscience↗

bioRxiv2025

FlashDeconv enables atlas-scale, multi-resolution spatial deconvolution via structure-preserving sketching

Coarsening Visium HD resolution from 8 to 64 m can flip cell-type co-localization from negative to positive (r = -0.12 [->] +0.80), yet many widely used compositional deconvolution workflows require coarsening or subsampling at million-bin scale. Here we introduce FlashDeconv, which combines leverage-score importance sampling with sparse spatial regularization to achieve competitive benchmark accuracy while processing 1.6 million bins in 153 seconds on commodity hardware. Systematic multi-resolution analysis of Visium HD mouse intestine reveals a tissue-specific resolution horizon (8-16 m), the scale at which this sign inversion occurs, validated by Xenium ground truth. Below this horizon, FlashDeconv provides, to our knowledge, the first sequencing-based quantification of Tuft cell chemosensory niches (15.3-fold stem cell enrichment). In a 1.6-million-bin human colorectal cancer cohort, FlashDeconv uncovers neutrophil inflammatory microdomains co-localized with immunoregulatory dendritic cells (mRegDC) at the tumor-stroma interface, spatial niches largely missed by discrete-label summaries, with RCTD doublet mode labeling only 2.3% of hotspot bins as neutrophil singlets.

bioinformatics↗

bioRxiv2025

Cigarette Smoke and E-Cigarette Aerosol Extracts Induce Myelopoiesis and Suppress Inflammatory Cytokine Production

Tobacco and nicotine use remain the leading preventable drivers of cancer risk, and both direct and secondhand exposure to combustible cigarettes or electronic nicotine devices perturbs immune function and hematopoiesis. Here, we evaluate the impact of e-cigarette vapor and combustible cigarette smoke on in vitro cell inflammatory responses and in vivo long-term hematopoietic differentiation. In cell-based studies, cigarette smoke extract (CSE) and e-cigarette vapor extract (EVE) consistently suppress LPS-induced TNF- secretion across macrophage/monocyte models, including primary mouse and human cells and complementary cell lines, indicating a reproducible immunosuppressive effect on mature myeloid cells. Brief ex vivo exposure to CSE also alters myeloid subset composition and modifies the proliferative behavior of Tet2-knockout cells, suggesting that smoke-related cues can reshape competitive dynamics among mutant and wild-type myeloid progenitors. To assess consequences of smoking behavior in vivo, we used a custom nose-cone inhalation system to deliver controlled exposures to combustible cigarette smoke or e-cigarette aerosol to mice. Chronic exposure increased myeloid proliferation, consistent with smoking behavior inducing premature aging of the hematopoietic stem cell pool. Thus, these studies support a model in which tobacco exposures blunt innate immune responsiveness while simultaneously driving myeloid expansion conditions that accelerate hematopoietic aging.

cancer biology↗

bioRxiv2025

Ser129 Phosphorylation Paradox: Non-phosphorylated α-Synuclein Drives Parkinson' s Disease-like Pathogenesis in Vivo

Accumulation of phosphorylated -synuclein at serine 129 is a hallmark of Parkinsons disease (PD), but its pathogenic role remains controversial. We conducted longitudinal studies using non-phosphorylatable S129A and phosphomimetic S129D -synuclein global knock-in mice. Unexpectedly, the S129A mice--rather than S129D mice--developed reproducible olfactory, motor, and cognitive deficits, dopaminergic dysfunction and neurodegeneration, -synuclein insolubility, and Lewy-like inclusions by 3 to 9 months, with progressive worsening up to 12 months of age. Spatial transcriptomics and electron microscopy revealed mitochondrial, synaptic, and protein ubiquitination abnormalities in the substantia nigra of S129A -synuclein mice. Viral vector-mediated nigral overexpression of S129D--synuclein or systemic administration of an anti--synuclein-aggregation drug partially alleviated the early neurological phenotypes of S129A mice. These results implicate non-phosphorylatable -synuclein as a direct pathogenic driver for PD.

neuroscience↗

bioRxiv2025

Dynamic domain interactions encode possible CheA autophosphorylation mechanisms revealed by coarse-grained simulations

Autophosphorylation of CheA is key to initiation of the phosphorylation cascade that eventually controls the direction of downstream flagellar motors for chemotaxis signaling in motile bacteria. The phospho-transfer reaction, from ATP bound in the P4 catalytic domain to a specific His residue in the P1 substrate domain in CheA, can be significantly accelerated within core signaling unit complexes containing chemoreceptors, CheA and CheW. Previous studies have proposed that CheA autophosphorylation activity is regulated by changing the dynamics of P4 and/or altering its interactions with P1 in response to signals transmitted from chemoreceptors. However, the positions of CheA P1 and P2 domains in the core signaling unit are not well-characterized because they form only transient interactions with other domains. Though previous studies have identified possible domain-domain interaction surfaces, especially for P1 and P4, a bottom-up analysis of these interactions has not been performed. Here, we employed extensive molecular simulations to analyze interactions among CheA domains using a hybrid resolution (HyRes) protein model designed for dynamic protein structures and interactions. The results revealed multiple major modes of dynamic P1/P4 interactions. In particular, P1 was found to bind dynamically near the preferential binding surfaces on P4 even in the ATP free state. ATP binding to P4 reduces the motion of P1 binding and promotes a trans- productive-like mode that brings His48 in close contact with the bound ATP for possible autophosphorylation. The predicted non-productive and productive P1/P4 interaction modes appear highly consistent with existing NMR, mutagenesis, and chemical modification data. Together, these findings provide a more complete picture of the dynamics of domain-domain interactions of CheA and new insights into the possible regulation mechanism of its autophosphorylation.

biophysics↗

bioRxiv2025

Functional modules predict cancer-relevant genetic interactions in mammalian cells

Genetic interactions can reveal gene function and identify disease-relevant synthetic lethals, but resource-intensive screening in human cells constrains experimental scope and limits our understanding of how generalizable sparse hits are. Here, we leverage principles from yeast genetic networks to identify human gene modules involved in receptor tyrosine kinase signaling and DNA damage response that are predicted to be enriched for genetic interactions, then use our enCas12a-based In4mer combinatorial knockout platform to efficiently screen these modules across diverse cancer cell lines. We identify hundreds of unreported synthetic lethals, including a dense network within the protein N-linked glycosylation machinery that shows both evolutionary conservation and network rewiring, and we confirm that interactions discovered in 2D cell culture are maintained in more physiologically relevant models. Critically, a meta-analysis within and between screens highlights sources of variation in published results, reveals the potential for false positives in screens with many essential genes, and demonstrates the need to move beyond DDR for actionable synthetic lethalities.

systems biology↗

bioRxiv2025

Proteolytic Control of an Auto-inhibitory Intrinsically Disordered Region Governs Small RNA Selectivity in Argonaute Proteins

Argonaute proteins are central to small RNA-mediated gene regulation, yet the mechanisms controlling their activity remain incompletely understood. We elucidate a novel regulatory mechanism governing small RNA loading into the C. elegans Argonaute proteins WAGO-1 and WAGO-3. We show that N-terminal intrinsically disordered regions (N-IDRs) of these proteins do not affect subcellular localization but play critical roles in small RNA loading. We demonstrate that the N-IDR-processing protease DPF-3 facilitates small RNA loading in a catalysis-independent manner. Catalysis by DPF-3 and a second protease APP-1 is required, however, for activity. Deletion of these N-IDRs results in loading of aberrant small RNA species that trigger erroneous gene silencing. Supported by atomistic molecular dynamics simulations, we propose a model in which N-IDRs can simultaneously act as tuneable gatekeepers that auto-inhibit small RNA loading and as regulators of Argonaute stability, representing a previously unrecognized layer of regulation in Argonaute activity in small RNA pathways.

molecular biology↗

bioRxiv2025

DINOcell: Learning Generalizable Perturbation Effects through Self-Distillation

AO_SCPLOWBSTRACTC_SCPLOWPredicting cellular responses to therapeutics is a promising approach for novel target discovery. However, state-of-the-art computational models designed to predict perturbation effects struggle to generalize and outperform simple baselines. We present DINOcell, a weakly supervised framework that adapts self-distillation to single-cell transcriptomics for predicting perturbation effects. We demonstrate that DINOcell outperforms baselines in predicting the effects of single gene perturbations. Furthermore, DINOcell accurately predicts non-additive effects of combination perturbations, indicating its capacity to model complex genetic interactions. Finally, we show that DINOcell learns representations that capture biological signals and is a promising, generalizable approach for in silico perturbation modeling, providing a valuable tool for accelerating therapeutic target discovery.

bioinformatics↗

bioRxiv2025

Nuclear N-Glycosylation Redefines the Glycoscape and Directs Cell Identity

Glycans modify nucleic acids, proteins and lipids in fundamental biological processes, but have long been considered confined to the secretory pathway and cell surface. Here, we challenge this view with evidence that N-glycosylation, a ubiquitous glycan modification, occurs within cell nuclei across tissues and species, exhibiting cell type-dependent abundance and localization patterns. Using a multi-faceted approach, we show that numerous classical membrane and secreted glycoproteins localize to the nucleus with N-glycan modifications, exemplified by the cell adhesion molecule L1CAM. Mechanistically, we show that the N-glycosylated L1CAM is transported to the nucleus by KPNB1, where it transcriptionally modulates neuronal differentiation. Moreover, this nuclear N-glycosylation event contributes to neurodevelopmental disorders and is pharmacologically reversible. These findings revise the cellular geography of N-glycosylation and expand the known routes of protein trafficking, and highlight nuclear N-glycosylation pathways as potential therapeutic entry points for developmental disorders.

cell biology↗