Biology subjects

Li, S.

Publications and source records attributed to Li, S..

At least 199 records · Page 11Linked to original sources

bioRxiv2026

A Single-Cell and Spatial 3D Multi-omic Atlas of Developing Human Basal Ganglia and Inhibitory Neurons

The human basal ganglia (BG), subcortical nuclei fundamental to motor regulation and cognitive modulation, is constructed from neurons produced during gestation in the adjacent ganglionic eminences (GEs). GEs are transient structures in the ventral prenatal brain that also generate GABAergic inhibitory neurons which migrate to destinations in the BG, cortex and other destinations. This study aims to elucidate the epigenomic and 3D-genomic dynamics involved in the specification and maturation of GEs and GE-derived neurons, using single-nucleus methyl-3C sequencing (snm3C-seq), highly-multiplexed spatial transcriptomics, and chromatin+RNA single-molecule imaging. Our multi-modal data support a heterogeneous temporal progression across GE subregions, with the lateral GE (LGE) showing declining neurogenic activity in mid-gestation and caudal GE (CGE) exhibiting ongoing developmental progression through infancy. We identified regulatory programs that specify subtypes of BG principal cells, medium spiny neurons (MSN), via synchronized maturation of the 3D-epigenome. In infant brains, we found a transient short-range enriched (SE) chromatin conformation during the transition between oligodendrocyte progenitors (OPCs) and oligodendrocytes (ODCs), and a temporary shift toward Long-range Enriched (LE) chromatin conformation in projection neurons, extending previous works showing the differentiation of neurons and glial cells is associated with permanent SE and LE conformation, respectively. Lastly, we found that gene regulatory regions active in MSNs were enriched in loci associated with genetic risk for neuropsychiatric disease. Our study delineates the highly complex, lineage-specific 3D genomic dynamics in ventral progenitors and basal ganglia populations of the perinatal human brain. HighlightsO_LIJoint 3D genome and DNA methylome analysis of ventral brain progenitor zones C_LIO_LIHeterogeneous developmental progressions of the ganglionic eminences C_LIO_LIDistinct development dynamics and regulatory landscape of MSNs and interneurons C_LIO_LITransient remodeling of the 3D-genome in neurons and oligodendrocyte progenitors C_LI

genomics↗

bioRxiv2026

Programmable artificial RNA condensates in mammalian cells

Artificial biomolecular condensates have emerged as powerful tools to control cellular behaviors. Here we introduce a method to build artificial condensates within living mammalian cells through the design of modular RNA motifs formed by a single, short strand of RNA. These condensates emerge spontaneously, creating RNA-rich compartments that remain separated from their surrounding environment. The RNA sequences include stem-loop domains that fold as the RNA is transcribed, and then condense in the nucleus and cytoplasm through loop-loop interactions. These sequences can be optimized and diversified, enabling the generation of distinct, non-mixing condensate populations and the programmable control of their subcellular localization. The RNA motifs can also be modified to recruit small molecules, proteins, and RNA molecules in a sequence-specific manner to the RNA-rich phase. By introducing additional RNAs that link two distinct types of condensates, we can create droplets with multiple subcompartments, whose organization can be controlled by tuning the stoichiometry of different RNA sequences. These artificial condensates provide a versatile platform for studying and manipulating molecular functions inside living cells.

synthetic biology↗

bioRxiv2026

Flexible perception of face attributes under naturalistic visual constraints

How does human brain adapt face perception to naturalistic visual constraints? While faces are typically perceived under dynamic and uncertain conditions, most studies use static presentation and enough temporal exposure, leaving the neural mechanisms of adaptive face processing poorly understood. Here, we employed steady-state evoked potential electroencephalography (EEG) to track how perception of multiple face attributes (age, emotion, gender, and race) adjusts to two ecologically relevant scenarios: (1) faces gradually sharpening from blur to clear (mimicking approaching from a distance), and (2) faces presented with incrementally increasing exposure times (mimicking brief, flashed encounters). By progressively increasing sensory input (via spatial frequency content in Experiment 1 and exposure time in Experiment 2) in a stepwise manner, we show that emotion and race categorization emerge early, even under high blur (e.g., 4.89 cycles/image) or brief exposures (e.g., 41.7-50 ms), reflecting coarse visual processing. In contrast, age discrimination requires higher clarity (e.g., 7.31 cycles/image) but shorter exposure (e.g., 41.7 ms) if clear images are presented. In both scenarios, gender processing exhibits the strongest dependence on clarity (e.g., 10.94 cycles/image) and time (e.g., 66.7 ms). Representational similarity analyses further show that reliable response patterns for emotion and race emerge earlier in the posterior brain region relative to those for gender in both experiments. Together, these results identify a flexible temporal order for face perception that adapts to naturalistic visual constraints, bridging the gap between controlled laboratory paradigms and naturalistic social vision.

neuroscience↗

bioRxiv2026

Identification a Compact Promoter using a New Promoter Selection Strategy and Engineering Hybrid Pol II/III Enable Efficient Genome Editing in Human Retinal Ganglion Cells

Promoters and vectors are critical components of gene therapy, enabling the delivery and expression of therapeutic genes to correct both loss- and gain-of-function mutations. Adeno-associated virus (AAV) vectors are the leading platform for in vivo gene delivery; however, the widely used Streptococcus pyogenes Cas9 (SpCas9, 4.1 kb) approaches the AAV packaging limit of 4.7 kb. This constraint often necessitates dual-vector systems, which reduce therapeutic efficiency, or the use of smaller nucleases such as SaCas9 (3.2 kb) and AacCas12b (3.4 kb), which have lower PAM site frequencies. To enhance promoter selection for gene therapy applications, we developed a strategy to identify compact, cell-preferred RNA polymerase II (Pol II) promoters. Analysis of approximately 300 compact Pol II promoters revealed that exogenous expression levels in one cell type correlate more strongly with those in other cell types than with endogenous expression, underscoring the importance of exogenous expression efficiency in promoter selection. Using this approach, we identified a compact Pol II promoter #2 (Pro2, 133 bp) that drives robust transgene expression in human retinal ganglion cells (RGCs). To enable single-AAV delivery of SpCas9, we analyzed three commonly used Pol III promoters (H1, 7SK and U6) and determined their minimal functional lengths using a CRISPR/Cas9 reporter assay. We further engineered three compact hybrid Pol II/III promoters which combined pro2 with minimal H1, 7SK and U6 (276, 294, and 323 bp) capable of co-expressing SpCas9 and gRNA, enabling efficient genome editing in both transfected HEK293 cells (approaching 100%) and human RGCs (up to 55.9%) from human stem cell-derived retinal ganglion cells (RGCs). Together, these findings establish a framework for developing single-AAV CRISPR-based gene therapy strategies. Authors contributionsPWZ and DJZ conceived the study, designed the experiments, performed data analysis and interpretation, and were the primary contributors to manuscript writing. STZ played a key role in data collection and correlation analysis. YYC, SL, LF, CJK, YD, CAB, JC, and DW contributed to the execution of essential experiments and subsequent data analysis. All authors have read and approved the final manuscript. Declaration of interestsThe authors declare no conflicts of interest.

molecular biology↗

bioRxiv2026

A brain dynamic model based on graph neural network reflect the inter-region interaction of cortical areas

A central objective in neuroscience is to elucidate how the brain generates complex dynamic activity through the interactions of brain areas. In this study, we utilized Interaction Network, a graph neural network model, to develop a computational framework for predicting whole-brain cortical blood oxygenation level dependent (BOLD) signals. We derived an Inter-Regional Interaction (IRI) metric to quantify information exchange among brain areas probing the underlying dynamical mechanisms. In addition, the total IRI emitted from each brain region was calculated and defined as the IRI sent by region (RS-IRI). Our model predicted the following 10 time points BOLD activity from initial BOLD signals, and achieved a mean absolute error of 0.04. The predicted functional connectivity (FC) achieves a correlation coefficient of 0.97 compared to the empirical FC. The fluctuation amplitude of the IRI increases with the length of the connection and the largest RS-IRI oscillation amplitude is observed in visual areas. The RS-IRI demonstrates a hierarchical organization, characterized by more concentrated distributions in association regions and larger fluctuation amplitudes in unimodal regions. Applying our approach to Alzheimers disease (AD), we demonstrate that the frequency-specific amplitudes of IRI oscillations discriminate AD patients from healthy controls and correlate with Mini-Mental State Examination scores. Together, this work presents a deep learning-based framework for modeling brain dynamics as well a quantitative index of inter-areal interactions, and offers a new perspective for disease characterization. Author SummaryThe human brain comprises distinct regions that interact through complex fiber tracts, forming the functional dynamics for diverse cognitive processes. We employed fMRI to assess functional activity and DTI to reconstruct fiber tract connectivity. To elucidate how brain function emerges from these inter-regional interactions, we developed a novel computational framework based on Graph Neural Network (GNN) to model the brains interactive dynamics for its capacity to uncover hidden and intricate patterns within data. From this model, we derived a quantitative metric termed Inter-Regional Interaction (IRI), which characterized the fine-grained, dynamic fluctuations in communication between brain areas. Our results suggest that this GNN-based model can accurately simulate brain functional activity and provide a quantitative description of neural interaction patterns. Applying this model to a cohort of Alzheimers disease patients, we demonstrated that the IRI metric not only effectively distinguished patients from healthy controls but also significantly correlated with clinical cognitive performance (MMSE scores). This approach advances our understanding of the fundamental principles of brain function and offers a promising tool for identifying the underlying mechanisms of neurological disorders.

neuroscience↗

bioRxiv2026

An Efficient Constant-Coefficient MSAV Scheme for Computing Vesicle Growth and Shrinkage

We present a fast, unconditionally energy-stable numerical scheme for simulating vesicle deformation under osmotic pressure using a phase-field approach. The model couples an Allen-Cahn equation for the biomembrane interface with a variable-mobility Cahn-Hilliard equation governing mass exchange across the membrane. Classical approaches, including nonlinear multigrid and Multiple Scalar Auxiliary Variable (MSAV) methods, require iterative solution of variable-coefficient systems at each time step, resulting in substantial computational cost. We introduce a constant-coefficient MSAV (CC-MSAV) scheme that incorporates stabilization directly into the Cahn-Hilliard evolution equation rather than the chemical potential. This reformulation yields fully decoupled constant-coefficient elliptic problems solvable via fast discrete cosine transform (DCT), eliminating iterative solvers entirely. The method achieves O(N2 log N) complexity per time step while preserving unconditional energy stability and discrete mass conservation. Numerical experiments verify second-order temporal and spatial accuracy, mass conservation to relative errors below 5 x 10-11, and close agreement with nonlinear multigrid benchmarks. On grids with N [≥] 2048, CC-MSAV achieves 6-15x overall speedup compared to classical MSAV with optimized preconditioning, while the dominant Cahn-Hilliard subsystem is accelerated by up to two orders of magnitude. These efficiency gains, achieved without sacrificing accuracy, make CC-MSAV particularly well-suited for large-scale simulations of vesicle dynamics.

biophysics↗

bioRxiv2026

Single-cell and spatial transcriptomics unveils key regulators governing cell differentiation for Schistosoma sexual development

Schistosomiasis remains a major global health challenge, primarily due to the large number of egg production by sexually mature parasites. However, the cellular basis and regulatory programs governing sexual development and egg production are poorly characterized. Here, we constructed a dynamic single-cell atlas of Schistosoma japonicum (S. japonicum) covering key development stages of sexual maturation and egg production, and integrated it for the first time with spatial transcriptomics to map tissue-resolved cellular niches. Through bioinformatic analysis and experimental validation, we identified several critical cell populations and regulatory networks that drive parasite development and egg laying. By mapping de novo identified transcription factors (TFs) onto these atlases, we generated a comprehensive spatiotemporal expression profile of TFs and define the regulatory programs of several tissue-specific TFs including Zfp, Fbp3, and Lim. Integrated re-clustering further revealed and validated key regulators of germline stem-cell differentiation in S. japonicum. Finally, comparative analyses with S. mansoni single-cell datasets revealed both conserved and species-divergent cellular plasticity, providing unprecedented insights into their distinct biological traits. Collectively, our comprehensive study establishes a foundational resource for understanding schistosome biology, deciphers regulatory programs underlying cell differentiation and pathogenicity, and accelerates the identification of key molecules involved in sexual development against schistosomiasis.

microbiology↗

bioRxiv2026

Efficiency, accuracy and robustness of probability generating function based parameter inference method for stochastic biochemical reactions

Biochemical reactions are inherently stochastic, with their kinetics commonly described by chemical master equations (CMEs). However, the discrete nature of molecular states renders likelihood-based parameter inference from CMEs computationally intensive. Here, we introduce an inference method that leverages analytical solutions in the probability generating function (PGF) space and systematically evaluate its efficiency, accuracy, and robustness. Across both steady-state and time-resolved count data, our numerical experiments demonstrate that the PGF-based method consistently outperforms existing approaches in terms of both computational efficiency and inference accuracy, even under data contamination. These favorable properties further enable the extension of the PGF-based framework to model selection--a task typically considered computationally prohibitive. Using timeresolved data, we show that the method can correctly identify complex gene expression models with more than three gene states, a task that cannot be reliably achieved using steady-state data alone.

systems biology↗

bioRxiv2026

Bacteria-herpesvirus interaction reveals a proviral role of ISGylation in promoting herpesvirus capsid assembly

Herpesviruses are common pathogens of the oral cavity, yet how they interact with other oral microbes are poorly understood. Using murine gamma-herpesvirus 68 (MHV68) as a model for human gamma-herpesviruses, we discover that ISGylation is hijacked to facilitate viral capsid assembly and lytic replication. Co-infection with the oral Aggregatibacter actinomycetemcomitans (A.a.) and MHV68 synergistically induced interferon-stimulated gene 15 (ISG15) expression and global ISGylation. Proteomic profiling revealed viral structural proteins as the dominant targets of ISGylation in MHV68-infected cells. Genetic ablation of ISGylation, using ISGylation-resistant recombinant MHV68 and ISG15-deficient mouse embryonic fibroblasts (MEFs), demonstrated that ISGylation of the major capsid protein ORF25 is required for efficient capsid assembly and maturation into the infectious C-type virions. Strikingly, introduction of a de novo ISGylation site into the ISGylation-resistant MHV68 was sufficient to restore ISGylation, capsid assembly, and virion maturation. Consistent with these findings, A.a. failed to enhance MHV68 lytic replication in ISG15-deficient MEFs. Extending this mechanism to representative herpesviruses, we showed that ISGylation of major capsid proteins is broadly required for efficient lytic replication. Together, these findings uncover a previously unrecognized strategy by which herpesviruses exploit an ISG15 innate immune effector, amplified by microbial co-infection, to promote virion biogenesis and productive infection.

microbiology↗

bioRxiv2026

Microhomology-mediated end joining acts directly on replication forks to repair single-ended double strand breaks

Replication stress, intrinsic to oncogenesis, often leads to fork breakage and double-strand break (DSB) formation. Conventionally, break-induced replication (BIR) is considered the primary mechanism for repairing replication-associated single-ended DSBs (seDSBs). Here, we demonstrate that microhomology-mediated end joining (MMEJ) acts directly to repair seDSBs at broken replication forks (fork-MMEJ), preferentially on the leading strands, and functions cooperatively with BIR. We also showed that while fork-MMEJ is promoted by Pol{theta}, it operates independently of MRE11/CtIP-mediated end resection, relies on RPA, and produces asymmetric deletion patterns, which is distinct from canonical MMEJ (cMMEJ) defined at replication-independent double-ended DSBs (deDSBs). ATR, activated as end resection proceeds, serves as a pivotal switch to suppress fork-MMEJ while promoting BIR. Combined inactivation of ATR and Pol{theta} synergistically kills cancer cells under high replication stress with minimal toxicity to normal cells. Together, our study provides fundamental insights into the MMEJ mechanism and offers new strategies for cancer treatment.

molecular biology↗

bioRxiv2026

Structural insights into the recognition and catalysis of tRNA by human NSUN2

The human RNA m5C methyltransferase NSUN2 catalyzes site-specific cytosine methylation across diverse RNA substrates and thereby regulates a wide range of biological and physiological processes. However, the molecular basis by which NSUN2 achieves broad substrate recognition while maintaining catalytic specificity has remained unclear. Here we determine structures of human NSUN2 in both substrate-free and substrate-bound states using X-ray crystallography and cryo-electron microscopy. Structures of NSUN2 in complex with multiple tRNA substrates reveal a structure-first, sequence-tolerant strategy in which NSUN2 actively remodels tRNA architecture, exposing the buried target cytosine and positioning it within the catalytic pocket for methyl transfer. This recognition strategy enables NSUN2 to accommodate diverse tRNA substrates through a largely conserved interaction interface. Guided by these structural insights, we identify a small-molecule inhibitor that suppresses NSUN2 activity and cancer cell proliferation. Together, our findings define the molecular principles underlying NSUN2-mediated RNA m5C modification and provide a structural foundation for targeting NSUN2 in cancers.

molecular biology↗

bioRxiv2026

Healthcare Infrastructure Shapes Evolutionary Trade-offs and Geographic Dissemination of Multidrug-Resistant Acinetobacter baumannii

Antimicrobial-resistant pathogens pose an existential threat to modern medicine, yet the evolutionary forces driving their adaptation in healthcare systems remain largely unexplored. We revealed that hospital network architecture functions as a primary selective pressure, driving pathogen evolution through infrastructure-dependent virulence-transmission trade-offs. Phylogenomic analysis of 5,023 Acinetobacter baumannii isolates across Chinas centralized healthcare system identifies two co-existing evolutionary strategies: a virulence-optimized clade (ESL2.4) that spread slowly (20.4 km per year) in low-connectivity hospitals, and a transmission-optimized clade (ESL2.5) that disseminate rapidly (65.2 km per year) through mega-city healthcare hubs, likely attributed to its capsule conversion and increased upper respiratory colonization. Comparative analysis with European A. baumannii populations demonstrates that healthcare connectivity, not geography, governs pathogen distribution through convergent genomic adaptations. Our simulation suggests competitive asymmetries of the two clades, following the ecotype principle and enabling stable coexistence. The COVID-19 pandemic provided a natural experiment validating these mechanisms: outpatient restrictions reduced transmission-optimized lineage spread by 89%, while virulence-optimized lineage persisted through inpatient networks. These findings establish healthcare infrastructure as a critical evolutionary driver with immediate implications for predicting and controlling antimicrobial resistance emergence across diverse healthcare systems.

microbiology↗

bioRxiv2026

Ac-FAPI-04 Promotes Anti-tumor Immunity via IL-27 Activation and Tnfaip3 Inhibition

BackgroundAccumulating evidence substantiates the capacity of targeted radionuclide therapy (TRT) to potentiate tumor immunotherapy responses. However, combining TRT and immunotherapies exhibits substantial varying efficacy, underscoring the importance of investigating mechanisms through which TRT remodels the tumor microenvironment (TME). Despite recent advancements, the specific signaling molecules mediated by TRT that regulate the functions of cytotoxic T lymphocytes (CTLs) remain unclear. MethodsGiven the demonstrated potential of -radionuclides targeting the fibroblast activation protein (FAP) in TRT, this study employed [225Ac]Ac-FAPI-04 to investigate the mechanisms of TRT-induced TME remodeling. The cytotoxic effects were first evaluated in the B16F10 cell line, followed by an assessment of its in vivo therapeutic efficacy in tumor-bearing mice. RNA-sequencing analysis was utilized to elucidate underlying signaling pathways involving immune responses. Results[225Ac]Ac-FAPI-04 significantly induced DNA double-strand breaks, further elevated ROS levels, and apoptosis in tumor cells. Transcriptomic profiling revealed that [225Ac]Ac-FAPI-04 activates the IL-27/JAK-STAT pathway to amplify interferon-mediated responses, indicating IL-27 serves as a critical regulatory signal for CTLs during TRT. A concomitant observation was the downregulation of Tnfaip3 following [225Ac]Ac-FAPI-04 treatment. Tnfaip3 is implicated in modulating CTLs behavior and intratumoral infiltration, while its downregulation was associated with the upregulation of cytotoxic effector molecules, as confirmed in this study. ConclusionThis study identifies a TRT-induced pattern of synergistic signaling mediated by IL-27 and Tnfaip3, which collectively enhances CTL recruitment and potentiates their cytotoxic function. These findings provide a detailed mechanistic rationale for strategies aimed at augmenting the therapeutic efficacy of TRT and immunotherapy combinations.

molecular biology↗

bioRxiv2026

The Red Rice Bran Extract (RRBE) Mitigates Photoaging by Targeting Mitochondrial Oxidative Stress and Regulating Thermal Damage Responses

The photoprotective efficacy of natural skin-active complexes is well recognized, yet their ap-plication is often hindered by the challenge of deciphering their complex, multi-component, and multi-target mechanisms. To bridge the gap between established phenotypes and molecular mechanisms, we developed an AI-driven integrated platform that combines phytochemical profiling, network pharmacology, and deep learning-based target prediction with rigorous biophysical validation. We applied this platform to investigate RRBE, a bioactive complex refined from red rice bran extract. In vivo clinical studies confirmed that RRBE significantly accelerates the resolution of UV-induced erythema, while cellular and 3D tissue models demonstrated robust suppression of oxidative stress and DNA damage responses. To decode its material basis, the platform deconstructed RRBE into 10 distinct chemical modules. Leveraging our SCOPE-DTI deep learning model for global target prediction, we identified flavonoids (Module 1) and phenolic acids (Module 10) as the primary bioactive drivers relevant to photoprotection. These computational predictions were structurally supported by molecular docking and definitively validated in a physiological environment via Cellular Thermal Shift Assay-Mass Spectrometry (CETSA-MS). Mechanistically, RRBE functions through a synergistic polypharmacology: (1) Module 1 components, represented by procyanidin B2, target NDUFA7 to stabilize mitochondrial function and mitigate ROS; (2) Module 10 components, exemplified by caffeic acid, ferulic acid, and p-coumaric acid, engage FKBP11 and HSP90AA1 to regulate protein homeostasis and stress responses. This work not only deciphers the polypharmacological basis of RRBEs photoprotective action but also validates a scalable "AI-guided, cell-validated" discovery pipeline, offering a rational paradigm for uncovering the protective benefits of complex natural extracts.

systems biology↗

bioRxiv2026

Arousal modulates functional connectivity through structured and hemispherically asymmetric community architecture during wakefulness

Arousal fluctuates continuously during wakefulness, yet how these moment-to-moment variations shape large-scale functional connectivity (FC) remains unclear. Here, we combined 7T fMRI with concurrent pupillometry to quantify, for every functional connection, how time-varying FC covaries with spontaneous arousal in the awake human brain. Rather than exerting a uniform influence across the connectome, arousal organized FC into a low-dimensional set of seven connectivity communities, each defined by characteristic network compositions. These communities exhibited systematic hemispheric asymmetries, specifically identifying a "left-hemisphere centripetal architecture" where the left hemisphere serves as a structural sink for the asymmetric convergence of arousal-modulated signals. Importantly, hemispheric asymmetry did not arise from global shifts in connectivity strength, but instead reflected structured spatial heterogeneity embedded within community architecture. This modular and asymmetric organization was highly preserved during naturalistic movie watching, indicating that arousal-related modulation of FC reflects intrinsic principles that generalize across awake cognitive contexts. Together, these findings demonstrate that moment-to-moment arousal fluctuations shape large-scale FC through structured, hemispherically asymmetric network organization during wakefulness.

neuroscience↗

bioRxiv2026

Microglial Lag3 Drives α-Synuclein--induced Neurotoxic Activated (A1) Astrocytes and Neurodegeneration

BackgroundNeuroinflammation and pathologic -synuclein (-syn) aggregation cooperate to drive dopaminergic neurodegeneration in Parkinsons disease, but the glial receptors that couple extracellular -syn to inflammatory cascades remain incompletely defined. Microglia express higher levels of lymphocyte activation gene 3 (Lag3) than neurons, yet the contribution of microglial Lag3 to -syn recognition, glial crosstalk, and neurodegeneration is unknown. MethodsBiochemical binding assays, live-cell imaging, cytokine profiling, and neuron-microglia-astrocyte co-culture paradigms were used to define Lag3-dependent -syn preformed fibril (PFF) binding, uptake, and microglial activation. To interrogate in vivo function, microglia-specific Lag3 conditional knockout mice (Lag3L/L-Cx3cr1CreER) and littermate controls received unilateral intrastriatal -syn PFF injections, followed by histological, biochemical, and behavioral assessments of -syn pathology, gliosis, nigrostriatal integrity, and motor performance. Results-syn PFFs bound microglial Lag3 with high specificity and nanomolar affinity and required Lag3 for efficient fibril internalization and induction of proinflammatory cytokines. Microglial Lag3 deficiency markedly blunted -syn PFF-evoked microglial activation, prevented cytokine-driven conversion of astrocytes into neurotoxic reactive A1 astrocytes, and abolished astrocyte-dependent neuronal death in vitro. In vivo, microglia-specific Lag3 deletion reduced cortical, striatal, and substantia nigra pS129 -syn pathology, suppressed microgliosis and A1 astrocyte induction, preserved substantia nigra dopaminergic neurons and striatal dopamine transporter/tyrosine hydroxylase expression, and ameliorated -syn PFF-induced motor deficits. ConclusionsThis study identifies microglial Lag3 as a key receptor linking extracellular -syn PFF recognition to inflammatory amplification, neurotoxic reactive A1 astrocyte conversion, and dopaminergic neurodegeneration. Together with prior work on neuronal Lag3, these findings support a cell-type-specific dual-axis model in which neuronal Lag3 mediates -syn propagation while microglial Lag3 drives glia-dependent neurotoxicity, positioning Lag3 as a promising precision therapeutic target in -synucleinopathies.

neuroscience↗

bioRxiv2026

On-virion structural dynamics reveal temperature- and receptor-coordinated activation of an alphacoronavirus spike

Human alphacoronaviruses primarily infect the human upper respiratory tract, yet how physiological temperature and receptor-binding coordinate viral spike (S) protein activation remain unclear. Using cryo-electron tomography and subtomogram averaging, we directly visualized the structural dynamics of S on human coronavirus 229E (HCoV-229E) virions under physiologically relevant temperatures and in the presence of the host receptor human aminopeptidase N (hAPN). We identified two prefusion S2 conformations, compact and loose, that interconvert reversibly by temperature, revealing intrinsic S2 "breathing" on virions. Receptor-binding domain (RBD)-up conformations are rare on apo virions but are promoted at physiological temperature and stabilized upon receptor binding. hAPN can bind bivalently to neighboring S, forming Gemini S-hAPN complexes. Receptor incubation further promotes conversion from prefusion to postfusion S, an effect enhanced at 33. Together, our results demonstrate an optimized temperature for the HCoV-229E viral fitness, establish temperature and receptor binding as synergistic regulators of alphacoronavirus S activation and define an integrated, on-virion model of S conformational transitions during viral entry. These findings provide a structural framework for understanding alphacoronavirus infectivity.

microbiology↗

bioRxiv2026

A comprehensive analysis of flagellar mutations in Vibrio cholerae: Trade-off mechanisms between motility loss and host adaptability

IntroductionCholera, caused by Vibrio cholerae, is a severe diarrheal disease threatening global health. The flagellum of V. cholerae functions not only for motility but also as an environmental sensor regulating virulence. The trade-off mechanism between motility loss and enhanced host adaptation remains unclear. ObjectiveThis study aimed to elucidate how flagellar mutations, which lead to a loss of motility, affect host adaptability in V. cholerae and to uncover the underlying molecular basis. MethodsWe analyzed 3,135 cholera-related samples to identify mutation hotspots in flagellar genes. A relevant flagellar mutant library was constructed and assessed for host adaptability. Multiple approaches, including molecular, genetic, transcriptomic, and proteomic analyses, were applied to dissect the FlgM-mediated pathway, with key findings revalidated in an adult mouse model using a specifically constructed 6N-labeled mutant pool. ResultsBig data analysis reveals those flagellar mutations in V. cholerae cluster in key structural and regulatory genes, including flhB, fliA, fliF, fliD, and fliM. Flagellar mutations led to a scenario where the secretion level of the regulator FlgM was negatively correlated with host adaptability. Intracellular FlgM inactivates either the {sigma}28 factor FliA directly or acts through the VarS/VarA-CsrA/BCD system, ultimately leading to the derepression of the quorum-sensing master regulator named hapR. HapR can directly bind to the promoters of genes involving in methionine transportation to regulate adaptability of V. cholerae. The 6N-labeled mutants pool experiment reconfirmed that motility loss promotes host adaptability via the FlgM-FliA-HapR-methionine axis. ConclusionOur findings demonstrate that secretion levels of the flagellar regulator FlgM drive an adaptive shift in V. cholerae from motility to host adaptability, mediated through quorum sensing and methionine metabolic reprogramming. This reveals a novel mechanism underlying bacterial evolution and pathogenicity.

microbiology↗