Biology subjects

Kong, X.

Publications and source records attributed to Kong, X..

At least 19 recordsLinked to original sources

bioRxiv2026

LEUTX mediates amplification of DUX4 signaling and aberrant myotube differentiation in facioscapulohumeral muscular dystrophy

Aberrant reactivation of an embryonic DUX4 transcription factor gene encoded in the D4Z4 macrosatellite repeats on chromosome 4q is considered the root cause of facioscapulohumeral muscular dystrophy (FSHD). While DUX4 target gene expression correlates with the clinical severity, DUX4 expression itself is very rare. How this limited DUX4 expression leads to definitive target gene activation and how these downstream genes contribute to FSHD pathology remain elusive. We previously found the evidence for LEUTX and ZSCAN4 representing two distinct DUX4 target subpathways. Here we present functional analyses in control and FSHD skeletal myocytes identifying LEUTX, but not ZSCAN4, as a major amplifier of DUX4 target gene expression. Furthermore, LEUTX uniquely disrupts myotube differentiation by impairing muscle gene induction and promoting persistent mitotic gene expression. Forced LEUTX expression causes aberrant DNA replication in myotube nuclei. A subset of misregulated genes is bound by LEUTX, strongly suggesting that they are direct targets of LEUTX. Notably, LEUTX requires the presence of DUX4 to gain access to DUX4 target gene promoters for their activation. Taken together, our results establish the critical role of LEUTX in DUX4 signal amplification and defective myotube differentiation, revealing distinct contributions of DUX4 target gene pathways in FSHD pathogenesis.

cell biology↗

bioRxiv2026

Acetylation of NDUFA13 at K7 Senses OXPHOS Dysfunction to Disrupt Prohibitin Scaffolds and Drive Cristae Remodelling in Heart Failure

Mitochondrial cristae disintegration is a hallmark of heart failure, yet how oxidative phosphorylation (OXPHOS) dysfunction triggers this structural collapse remains unclear. Here we identify acetylation of the complex I subunit NDUFA13 at lysine 7 (K7) as a metabolic sensor coupling OXPHOS dysfunction to cristae remodelling. OXPHOS inhibition drove NDUFA13-K7 hyperacetylation, inducing conformational compaction and translocation to the intermembrane space. Acetylated NDUFA13 competitively engaged PHB2 through its coiled-coil domain, displacing PHB1 and disassembling prohibitin scaffolds. The acetylation-mimetic NDUFA13-K7Q induced cristae fragmentation in vitro, and cardiomyocyte-specific K7Q knock-in mice showed accelerated mortality and cristae loss under pressure overload, accompanied by impaired TCA cycle flux, defective fatty acid oxidation and selective depletion of polyunsaturated cardiolipins. These findings establish NDUFA13-K7 acetylation as a reversible switch converting bioenergetic failure into pathological cristae remodelling and metabolic reprogramming, highlighting therapeutic potential for targeted deacetylation.

cell biology↗

bioRxiv2026

Diffusion MR Microscopy of the Human Hippocampus at 50 μm Resolution at 14.1 T for 3D Virtual Histology

Bridging the gap between macroscopic neuroimaging and microscopic histology remains a challenge in neuroscience. Here, we present a technical feasibility study of diffusion MR microscopy (dMRM) in the ex vivo human hippocampus using a 14.1 T ultrahigh-field MRI system. Mid-hippocampal blocks from control and Alzheimers disease (AD) patients were acquired at 50 x 50 x 100 {micro}m3, representing, to our knowledge, the highest resolution reported for human brain diffusion MRI. At a spatial scale approaching cellular dimensions, dMRM maps and tractography showed close correspondence with immunohistological markers of axons and dendrites. The acquired data delineated six hippocampal laminae, distinguished the inner and outer molecular layers, and preserved short, lamina-specific trajectories that became attenuated or blurred at 100 {micro}m resolution. Tractography further depicted the major components of the hippocampal tri-synaptic circuit--the perforant path, mossy fibers, and Schaffer collaterals in 3D. In the AD specimen, dMRM revealed reduced laminar contrast, local discontinuities, and altered radial and tangential fibers that were paralleled by pathological staining. With the 3D nondestructive characterization of human brain microstructure and circuitry, ex vivo dMRM showed its potential toward the goal of 3D virtual histology.

neuroscience↗

bioRxiv2026

Brassinosteroid-auxin crosstalk shapes rice flag leaf angle to boost dense planting yield

Flag leaf angle (FLA) critically determines rice yield potential under dense planting conditions. As two pivotal phytohormones determine rice FLA, the antagonistic interaction between brassinosteroid (BR) and auxin remains largely uncharacterized. We here demonstrate that BR signaling reduces auxin biosynthesis to control FLA via regulating the biosynthesis of secondary cell wall (SCW). Genetic evidence demonstrates OsYUC8 mutants disrupt SCW formation, leading to increased FLA. At the molecular level, the BR-related transcription factor OsBZR1 directly binds to and represses OsYUC8 promoter activity, thereby fine-tuning auxin-mediated SCW biosynthesis. Field evaluations reveal that osbzr1 mutants display optimized flag leaf architecture and improved yield performance under high-density cultivation. Our study not only delineates the antagonistic BR-auxin interaction governing FLA but also establishes a genetic strategy for manipulating crop architecture to maximize yield in dense planting conditions. One-sentence summaryOsBZR1-mediated repression of OsYUC8-driven auxin biosynthesis modulates secondary cell wall formation to optimize flag leaf architecture, providing a genetic strategy for maximizing yield under high-density cultivation.

plant biology↗

bioRxiv2026

Accurate de novo design of peptides from programming biophysical landscape

Peptides regulate virtually every cellular process and emerge as transformative modalities in bioengineering and therapeutics. However, the de novo design of functional peptides remains challenging, as peptide-protein interactions are governed by delicate and dynamic biophysics that are difficult to model, and experimental datasets are scarce. Here we present NeoPep, a generative deep-learning framework that encodes biophysical principles to accurately design functional peptides de novo. By integrating over 5 million peptide-protein complexes spanning experimentally determined, sequence mimics, and structure ensembles, NeoPep learns the complex biophysical landscape governing peptide function and enables its programmable control. In prospective application across 10 diverse and challenging targets, NeoPep generated potent peptide binders, agonists, and antagonists with hit rates of 12.5-66.7%, even in the absence of defined binding sites or structure information. Beyond de novo co-design, NeoPep supports standalone structure or sequence redesign, readily discriminating subtle context differences. In the structure redesign mode, it generates highly selective peptides with atomic-level conformational accuracy (C RMSD < 2.0 [A] to our solved cryo-EM structure). This structural precision circumvents the need for experimental structure determination, further accelerating iterative sequence redesign to yield a 43.3-fold improvement in potency. These findings establish a general framework for translating biophysical principles into actionable peptide functions, with broad implications for basic research, bioengineering, and medicine.

molecular biology↗

bioRxiv2026

Plac1 Ablation Disrupts Signaling Pathways Essential for Prenatal Development and Induces a Preeclampsia-Associated Transcriptomic Signature

Plac1 is an X-linked gene essential for placental and embryonic development. A knockout (KO) mouse model was used to define placental gene expression changes associated with Plac1 loss at E16.5 and E18.5 using gene expression microarray. Genes exhibiting at least a 1.5-fold change and FDR < 0.05 were considered significant. At E16.5, 717 genes were downregulated and 796 upregulated in KO placentas relative to wild type (WT), whereas at E18.5, 1121 genes were downregulated and 1151 upregulated. Subsets of highly and uniquely dysregulated genes were examined by gene-level curation alongside systems-level analyses, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Ingenuity Pathway Analysis (IPA), applied to the full differentially expressed gene (DEG) datasets. Downregulated genes were enriched for Rho GTPase-mediated and actin cytoskeleton-based processes, as well as membrane-associated signaling pathways with established roles in placental and embryonic development, vascular function, and branching morphogenesis. Overlap with pathways and molecular features associated with preeclampsia was also observed. In contrast, upregulated genes reflected, in part, immune activation and oxidative stress responses. These findings represent an important exploratory, hypothesis-generating analysis and provide a biologically coherent framework for understanding how Plac1 loss may be associated with placental dysfunction and pregnancy-related disease.

developmental biology↗

bioRxiv2026

Lipid mobilization establishes metabolic tolerance and prevents autonomic collapse in infection

Survival during infection depends on both pathogen clearance and the ability to tolerate infection-induced physiological changes. Metabolic adaptations are a central component of this tolerance, but the mechanisms underlying these responses remain incompletely defined. Here, we identify white adipose tissue (WAT) lipolysis as a central regulator of metabolic tolerance to infection. In patients with sepsis, higher circulating non-esterified fatty acid (NEFA) levels were associated with reduced mortality. In mouse models of polymicrobial sepsis, infection induced robust adipose lipolysis and increased circulating NEFAs. Genetic ablation of adipose triglyceride lipase (ATGL) in adipose tissue impaired lipolysis, leading to hypothermia, bradycardia, and increased mortality without altering immune cell populations or pathogen burden, consistent with a defect in tolerance rather than resistance. Mechanistically, lipolysis-derived NEFAs, but not glycerol, were required for protection, as restoring circulating NEFAs rescued autonomic stability and survival in adipose tissue ATGL-deficient mice. Infection-induced lipolysis was redundantly regulated and did not depend on any single upstream signaling pathway. Both pharmacologic activation of lipolysis using a {beta}3-adrenergic agonist and exogenous fatty acid supplementation increased circulating NEFAs, improved survival, and promoted tolerance in mice. Consistent with these findings, analysis of real-world electronic health record data demonstrated that septic patients receiving FDA-approved {beta}3-adrenergic agonists had reduced mortality or hospice discharge in a propensity-matched cohort. Together, these results identify WAT lipolysis and circulating fatty acids as key mediators of tolerance to infection and support a therapeutic strategy based on repurposing clinically available {beta}3-adrenergic agonists to improve outcomes in sepsis. One Sentence SummaryWhite adipose tissue lipolysis promotes metabolic tolerance to infection through circulating fatty acids and is associated with improved survival in sepsis

physiology↗

bioRxiv2026

A Divergent Class of Arylamine N-Acetyltransferases Catalyzes Convergent Amidative Condensation of Polyketides in Manumycins Biosynthesis

Polyketides are prized for their structural complexity and therapeutic potential, yet the incorporation of amide bonds into their frameworks typically relies on linear, nonribosomal peptide synthetase (NRPS)-dependent assembly. The direct, convergent coupling of distinct polyketide chains via amide bond formation--an ideal strategy for combinatorial biosynthesis--has remained largely elusive. Here, we report the discovery of a novel family of arylamine N-acetyltransferases (NATs) from manumycin-type biosynthetic pathways that catalyze an unprecedented intermolecular amidative chain transfer/condensation between an acyl carrier protein (ACP)-tethered polyketide donor and a free polyketide acceptor. Biochemical, structural, and molecular dynamics studies reveal that the representative enzyme, ColC2, possesses a distinctive substrate-binding pocket that diverges from canonical arylamine NATs, conferring exceptional promiscuity toward diverse acyl donors and acceptors. We demonstrate the utility of this biocatalyst by coupling arylamines with either synthetic acyl-thioesters or polyketide synthase (PKS) machinery to generate a library of non-natural polyketide amides and manumycin derivatives. These findings establish a new paradigm for amide bond formation in polyketide biosynthesis and position arylamine NATs as powerful tools for the development of novel therapeutics through combinatorial synthesis.

synthetic biology↗

bioRxiv2026

Programming Biomolecular Interactions with All-Atom Generative Model

Biomolecular interactions lie at the core of cellular life, spanning diverse molecular modalities from small molecules to nucleic acids and proteins. Nevertheless, design strategies remain separated despite shared physicochemical principles of molecular recognition. Here we present AnewOmni, a unified generative framework trained on more than 5 million biomolecular complexes, that enables transferable molecular design across molecular scales by assembling chemically meaningful building blocks at atomic resolution. We further introduce programmable graph prompts to support user-defined chemical, topological, and geometric steering during generation, exploring hybrid and unconventional chemistries beyond canonical structures. We demonstrate that transferable learning of interaction patterns and physical constraints across molecular modalities is possible, via an atom-to-block latent space capturing both atomic details and structural priors. The framework successfully designed small molecules, peptides, and nanobodies targeting the challenging KRAS G12D switch II pocket, as well as orthosteric peptides and allosteric small-molecule inhibitors for PCSK9 in the absence of known binding site, achieving 23%-75% success with only low-throughput validation, bypassing modality-specific high-throughput screening. AnewOmni is the first to succeed in functional molecular design across all scales, from small chemical entities to large biologics, and represents a stepstone towards general molecular reasoning engines, advocating a generative foundation model for biomolecular interactions to enter regimes where data and human intuition remain limited.

bioengineering↗

bioRxiv2026

Peripheral B cell populations tune spontaneous neuronal activity in the uninjured hippocampus after stroke

B cells infiltrate the contralesional hippocampus following stroke, but whether lymphocytes modulate post-stroke plasticity and neuronal network function remains unknown. To identify immune cell mechanism(s) supporting remote plasticity, we examined the impact of B cell depletion on synaptic and neuronal activity in the hippocampal circuit following stroke. Basal synaptic transmission in the contralesional dentate gyrus (DG) following a stroke in adult male mice was decreased with B cell depletion. Expanding our studies to encompass the CA1 and DG regions of the hippocampal circuit in male and female mice of different ages, we utilized synapsin-Cre/GCaMP6s mice to visualize spontaneous calcium activity during a 3-week B cell depletion with and without prior stroke. Systemic B cell depletion in the absence of injury altered neuronal activity in the DG, suggesting a novel neuromodulatory role for circulating immune cells. Stroke increased Ca2+ transient amplitudes in the contralesional DG and CA1, with B cell depletion again reducing DG amplitudes while increasing the frequency of Ca2+ transients. Robust linear regression revealed significant main effects and higher-order interactions (depletionxsexxagexinjury), including increased Ca2+ transient amplitudes in older post-stroke mice lowered by systemic B cell depletion, though overall the DG appears more sensitive to modulation versus CA1. These results suggest that circulating B cells can tune hippocampal network activity dependent on age, sex, and the presence of brain injury. The selective vulnerability of the DG to depletion-age-injury interactions opens an avenue for future studies on region-specific neuroimmune crosstalk during post-stroke cognitive recovery. Presubmission inquiry for NeuronWe uncover crucial insights on the capacity of circulating B cells to directly modulate hippocampal network activity, showing that B cells are not just passive players, but active neuromodulators whose effects are dependent on sex, age, and stroke injury status. In fact, B cells are central players to functional recovery whose evolving role shifts over time, from acutely beneficial and neurotrophic to chronically maladaptive, depending on timing, context, and responding B cell subset. Our study demonstrates a mechanistic link between systemic immune modulation and neuronal calcium activity. This integrative perspective aligns with Neurons mission to publish studies that link cellular processes to systems-level functions. These novel findings also add to a more unified model of neuro-immune interactions that highlights how immunotherapies could be harnessed to improve neuronal function during stroke and aging, with several FDA-approved immunotherapeutics available to modulate systemic adaptive immune responses.

neuroscience↗

bioRxiv2026

VC-RDAgent: An efficient rare disease diagnosis agent via virtual case construction informed by hybrid statistical-metric and hyperbolic-semantic prioritization

While Large Language Models (LLMs) have shown promise in clinical decision support, current Retrieval-Augmented Generation (RAG) paradigms face a fundamental bottleneck in rare disease diagnosis: the scarcity, privacy restrictions, and extreme heterogeneity of real-world patient records. This reliance on sparse or inaccessible data leads to a severe "retrieval mismatch," where the lack of high-quality reference cases causes diagnostic performance to degrade sharply. To break this deadlock, we propose VC-RDAgent, a privacy-preserving and offline-capable framework that decouples diagnostic reasoning from sensitive real-world records by synthesizing virtual standardized cases. The system is powered by VC-Ranker, a multi-dimensional engine that integrates statistical-metric measures with hyperbolic-semantic embeddings to capture deep hierarchical ontology relationships. This approach allows for the dynamic generation of high-fidelity virtual references directly from authoritative knowledge bases. Extensive benchmarking across four diverse datasets demonstrates that VC-RDAgent effectively functions as a "performance equalizer." It boosts average Top-1 hit rates by 8.7% to 85.9% over zero-case baselines, enabling lightweight open-source models to rival frontier commercial systems. Notably, VC-Ranker alone achieved an aggregate Top-10 hit rate of 0.819, outperforming prior state-of-the-art methods by 6%. By eliminating the dependency on real-time web retrieval and private case sharing, VC-RDAgent provides a scalable, robust, and clinically deployable solution to shorten the diagnostic odyssey, which is made accessible through an intuitive, chat-based web application https://rarellm.service.bio-it.tech/rdagent/.

bioinformatics↗

bioRxiv2026

Ripk1 Deficiency or K376R Mutation in Dendritic Cells Promotes Potent Antitumor Immunity

Dendritic cells (DCs) are critical for initiating adaptive immunity through antigen presentation and T cell priming. While immunogenic cell death (ICD) enhances anti-tumor immunity, how programmed cell death in DCs shapes tumor immune responses remains unclear. Receptor-interacting protein kinase 1 (RIPK1) regulates apoptosis, necroptosis, and inflammation. Here, we show that mice with disrupted RIPK1 ubiquitination on K376 (Ripk1fl/K376R Cd11c-Cre, Ripk1DC-KO/K376R) develop inflammation and autoimmunity, phenocopying DC-specific RIPK1-deficient(Ripk1fl/fl Cd11c-Cre, Ripk1DC-KO) mice. These phenotypes were rescued by the genetic ablation of Ripk3 or Mlkl, establishing that RIPK1 ubiquitination is essential for suppressing DC necroptosis to maintain immune homeostasis. Remarkably, both Ripk1DC-KO and Ripk1DC-KO/K376R mice exhibit robust resistance to tumor growth, characterized by significantly enhanced T cell infiltration and activation. Mechanistically, we show that Ripk1 deficiency or the loss of its K376 ubiquitination augments antigen-presenting capacity of DCs through both necroptosis-dependent and -independent pathways. Furthermore, adoptive transfer of T cells from Ripk1DC-KO mice further amplifies anti-tumor immunity in recipient hosts. These results identify RIPK1 as a critical immunological checkpoint in DCs that constrains their immunogenic potential. Targeting this pathway represents a promising therapeutic strategy to potentiate T cell-mediated cancer immunotherapy.

immunology↗

bioRxiv2026

PCRD-seq: Proximity Crosslinking-induced RNA Depletion for Low-Input Subcellular Transcriptome Profiling

Chromatin-associated RNAs play critical roles in regulating chromatin organization and transcription, underscoring the importance of their study. Proximity labeling has emerged as a promising and versatile technique for profiling chromatin-associated RNAs with high spatiotemporal resolution. While being a powerful technique, traditional proximity labeling methods depend on complex, high-input enrichment protocols, which significantly limit their wide practical application. Here, we developed a straightforward, enrichment-free chromatin-associated RNA profiling strategy: Proximity Crosslinking-induced RNA Depletion sequencing (PCRD-seq). This approach leverages the proximity crosslinking between chromatin and its surrounding RNAs induced by singlet oxygen generated by HoeDBF, a photosensitizer targeting chromatin region. The proximity crosslinking hinders the release of chromatin-associated RNAs during routine TRIzol extraction, consequently leading to a specific depletion of these RNAs. This method was successfully applied to investigate the role of U1 snRNA in RNA chromatin retention and the differences in chromatin-associated transcriptomes between two ovarian cancer cell lines with opposite metastatic capability. Moreover, our PCRD-seq exhibits potential in profiling nuclear lamina-associated RNAs, which paves the way for its application to profile RNAs associated with other chromatin subdomains. The minimal cell input and simple workflow endow PCRD-seq as a transformative tool for wide applications.

cell biology↗

bioRxiv2026

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

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

evolutionary biology↗

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↗

bioRxiv2025

Genome-wide analysis of FSHD cell lines using Nanopore sequencing reveals allele-specific differences at DUX4 target genes and complex repeats

Facioscapulohumeral muscular dystrophy (FSHD) is linked to a monoallelic contraction of primate-specific 3.3kb D4Z4 macrosatellite repeats on the disease-permissive chromosome 4q (4qA haplotype) with additional mutations of a chromatin regulator SMCHD1 acting as a disease modifier. DNA hypomethylation at the D4Z4 repeat and resulting abnormal derepression of the embryonic transcription factor DUX4 encoded in the D4Z4 repeat are the hallmark of FSHD. In order to investigate the impact of FSHD mutations within as well as outside of the disease loci, we performed Nanopore direct-RNA and genomic sequencing to characterize global and D4Z4-specific changes in isoform expression and DNA methylation using CRISPR-engineered human skeletal myoblast lines carrying FSHD mutations (D4Z4 contraction and SMCHD1 mutation) compared to the isogenic parental healthy control line. Nanopore sequencing allowed us to characterize the entire unedited control and contracted D4Z4 arrays as well as distinguish differential methylation patterns at the disease locus on chromosome 4qA from those at a nearly identical nonpathogenic D4Z4 repeat arrays on chromosome 10 and disease non-permissive 4qB allele. We observe hypomethylation both at the DUX4 locus and globally in FSHD mutant cell lines in myoblasts as well as in myotubes. DUX4 target gene expression is correlated with promoter hypomethylation. De novo haplotype phasing of genomic and RNA reads reveals allele- and isoform-specific expression of DUX4 target genes as well as highly expressed DUX4 target pseudogenes that may contribute to disease pathogenesis. Taken together, our results indicate significant impact of FSHD mutations not only on D4Z4 allele, but also DUX4 targets and repeat regions in the genome, which may be collectively contributing to the FSHD pathogenesis.

genomics↗

bioRxiv2025

An Integrated Single-Cell Atlas Reveals Hepatic Stellate Cell Heterogeneity and Spatiotemporal Dynamics after Liver Injury

BackgroundHepatic stellate cells (HSCs) orchestrate fibrosis-free repair after acute liver injury (ALI) and sustain fibrogenesis in chronic liver injury (CLI). However, the heterogeneity and spatiotemporal dynamics of HSCs across these different injury models remain elusive. This study sought to construct a cross-etiological HSC atlas to delineate HSC states and transitions during liver injury. MethodsWe integrated 86,072 single-cell transcriptomes from 84 mouse samples across four etiologies and validated findings using multi-omics data from 277 mouse and 798 human samples. Cellular dynamics were characterized through clustering, trajectory inference, spatial analysis, and multicellular coordination network analysis. Experimental validation included liver injury models and gain-of-functional assays in primary mouse HSCs and LX-2 cells. ResultsWe established a cross-etiological, spatiotemporally resolved HSC atlas comprising 11 subpopulations. Trajectory analysis delineated a continuous quiescence-activation-attenuation (QAA) trajectory, recapitulating the in vivo full spectrum of state transitions and being supported by sequential pathway activation validated in vitro. In ALI, HSCs spatiotemporally completed the QAA trajectory around injury zones, whereas collagen-producing S100a6 HSCs pathologically accumulated in mouse and human CLI due to trajectory dysregulation. Notably, the atlas identified a previously unrecognized apoptosis-prone Mrc2 HSC subtype strongly co-localized with p53 in both mice and humans. Overexpression of transcription factors confirmed that Hbp1, Tbx20, Atoh8, and Plagl1 enriched in Mrc2+ HSCs promoted HSC apoptosis. Finally, we revealed the microenvironment of distinct cellular modules which coordinated HSC progression along the QAA trajectory. A 531-gene signature derived from the inflammatory-fibrotic cellular module significantly correlated with fibrosis stage and hepatocellular carcinoma risk in human cohorts. ConclusionsWe established a comprehensive HSC atlas and delineates HSC heterogeneity and spatiotemporal dynamic across etiologies. Dysregulation of the QAA trajectory underlies fibrotic progression, providing a resource for identifying antifibrotic targets.

cell biology↗

bioRxiv2025

SpecLig: Energy-Guided Hierarchical Model for Target-Specific 3D Ligand Design

Structure-based generative models often optimize single-target affinity with ignorance of specificity, resulting in the generation of high-affinity candidates that exhibit promiscuous binding across unrelated targets. This decoupling of affinity and specificity not only compromises therapeutic efficacy but also elevates off-target risks that constrain translational potential. Therefore, we introduce SpecLig, a unified structure-based framework that jointly generates small molecules and peptides with improved target affinity and specificity. SpecLig represents a complex as a block-based graph, combining a hierarchical SE(3)-equivariant variational autoencoder with an energy-guided geometric latent-diffusion model. Chemical priors derived from block-block contact statistics are explicitly incorporated, biasing generation towards pocket-complementary fragment combinations. We benchmark SpecLig on peptide and small-molecule tasks using standard public datasets and propose precision/breadth testing paradigms to quantify specificity. Across multiple evaluations, ligand candidates generated by SpecLig usually bind to the target pocket with high specificity and affinity while maintaining competitive advantages in other attributes. Ablations indicate that both hierarchical representation and energy guidance contribute to success. Finally, we present multiple real applications that demonstrate how SpecLig improves ligands in natural complexes to mitigate potential off-target risks. SpecLig, therefore, provides a practical route to prioritize higher-specificity designs for downstream experimental validation. The codes are available at: https://github.com/CQ-zhang-2016/SpecLig.

bioinformatics↗