Biology subjects

Yu, X.

Publications and source records attributed to Yu, X..

At least 127 records · Page 7Linked to original sources

bioRxiv2025

Transcript-Capture sequencing enriches mRNA of Mycobacterium tuberculosis from host samples

Bacterial gene expression from sites of infection are poorly studied due to low levels of bacterial mRNA present in clinical samples. Here, we develop Transcript-Capture Seq, which uses customizable biotinylated probes generated in-house to enrich bacteria-specific RNA from host samples before Next Generation Sequencing (NGS). This method results in a >200-fold increase in bacterial mRNA reads from mixed samples and allows analysis of the complete bacterial transcriptome from clinical samples. We apply Transcript-Capture to models of tuberculosis (TB) infection as well as sputum samples from TB patients. TB patients exhibit unexplained heterogeneity in disease progression, and the activity of Mycobacterium tuberculosis (Mtb) has been proposed to affect treatment response. By applying Transcript-Capture to sputum samples collected from TB patients we generate the first complete in vivo bacterial transcriptome of Mtb via NGS. Mtb from patient sputa shows upregulation of genes involved in host lipid utilization and zinc limitation, as well as a similar gene expression profile to Mtb log phase growth in vitro. Applying Transcript-Capture to clinical sputa provides a snapshot of bacterial activity directly from human patients and can be used to investigate the physiological state of bacteria surviving in vivo. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=74 SRC="FIGDIR/small/685133v1_ufig1.gif" ALT="Figure 1"> View larger version (21K): org.highwire.dtl.DTLVardef@406294org.highwire.dtl.DTLVardef@1080173org.highwire.dtl.DTLVardef@973909org.highwire.dtl.DTLVardef@21becc_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2025

Multicellular Calcium Waves in Cancer-Associated Fibroblasts Regulate Neuronal Mimicry and Anisotropy Leading to Immune Exclusion

Stromal barriers exclude CD8+ T cells from accessing cancer cells and hamper immune-mediated tumour control. Through multi-pronged analysis of tumours that transition from immune inflamed to immune excluded, we reveal that the formation of stromal barriers is associated with the acquisition of neuronal gene expression programmes in cancer-associated fibroblasts (CAFs), including TUBB3 expression. This leads to neuronal mimicry, with stromal barrier formation underpinned by coordinated transient bursts of intracellular calcium release, similar to those observed in neuronal tissue. Blockade of calcium release through either pharmacological or molecular interventions, such as STC2 depletion, prevents CAF alignment and the build-up of CD8+ T cells at stromal boundaries. Nintedanib treatment prevents neuronal mimicry and restores immune-mediated tumour control. Thus, we uncover unexpected mimicry of neuronal behaviour in CAFs, document the mechanism by which it leads to immune exclusion, and identify ways to prevent the induction of neuronal mimicry and restore immune-mediated tumour control. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=95 SRC="FIGDIR/small/684281v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@938ee5org.highwire.dtl.DTLVardef@18a9c48org.highwire.dtl.DTLVardef@11a5982org.highwire.dtl.DTLVardef@ea6a79_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2025

Oncogenic EGFR rewires STING-TBK1 immune machinery to license DNA damage tolerance

EGFR hotspot mutations (mEGFR), including primary L858R, exon 19 deletion, and secondary T790M, are pivotal oncogenic drivers in human non-small cell lung cancer (NSCLC). Meanwhile, NSCLC resistance to third-generation tyrosine kinase inhibitors (TKIs) is a major clinical challenge and remains mechanistically unresolved. Here, we uncover a previously unrecognized immunological mechanism whereby mEGFR exploits cGAS-STING innate immune signaling, conventionally regarded as tumor-suppressive, to sustain oncogenic signaling and therapeutic resistance. Mechanistically, mutant EGFR kinase aberrantly incorporates into STING signalosomes, directly phosphorylating STING (Y245/Y314) and TBK1 (Y577/Y677), stabilizing and hyperactivating TBK1 proteins, and establishing an unexpected and kinase loop critical for DNA damage repair. Disruption of this mEGFR-STING-TBK1 axis, genetically or pharmacologically, profoundly sensitized resistant patient-derived NSCLC organoids to chemotherapy. Combining TBK1 inhibition with cisplatin notably eradicated mEGFR-driven tumors in spontaneous and immunocompetent NSCLC murine models and patient-derived organoids. Our findings suggest a new function of cGAS-STING in the DNA damage repair program, its paradoxical exploitation by oncogenic driver mutations, and an innate immune therapeutic vulnerability in NSCLC.

cancer biology↗

bioRxiv2025

Blind Virtual Screening at Scale: A Scalable End-to-End Pipeline for Blind Docking and Affinity Prediction

Accurate and scalable prediction of protein-ligand interactions remains a central challenge in computational drug discovery, especially when the binding site is unknown (i.e., blind docking). We present a high-throughput, end-to-end algorithm for virtual screening that combines DiffDock, a diffusion-based generative model for blind docking, with UniDock Vina, an algorithm for rapid scoring. We benchmarked this approach on the CASF-2016 and DUD-E datasets, analyzing pose quality, scoring accuracy, and screening performance. We find that competitive screening power can be achieved when generating and scoring as few as three poses and without pose refinement, which facilitates scalability. Notably, our method achieves 86.78% and 82.00% for the percent of actives among the top 1% and 10% of ranked ligands, respectively, when generating as few as three poses per protein-ligand pair. The workflow is scalable, supporting blind docking and affinity prediction at a mean throughput of 0.76 seconds per protein-ligand pair when generating 40 ligand poses in batched mode parallelized to 8 NVIDIA A100 80G GPUs. These results demonstrate that accurate, large-scale blind virtual screening is feasible and offers a practical solution for screening against novel or less characterized protein targets. Code is available at: https://github.com/xinyu-dev/blind-screening-benchmark

bioinformatics↗

bioRxiv2025

Age- and Sex- Driven Transcriptional and Metabolic Diversity in Myeloid-Derived Suppressor Cells After Mouse Sepsis

Sepsis induces profound immune dysregulation, often resulting in chronic critical illness characterized by persistent immunosuppression and poor outcomes. Myeloid-derived suppressor cells (MDSCs) are central mediators of this immunosuppressive phenotype, yet the influence of age and sex on their transcriptional and metabolic states remain poorly understood. Here, we employed single-cell RNA sequencing of splenic leukocytes from young (3-4 months) and older (18-24 months) adult male and female mice subjected to a clinically relevant murine sepsis model to define age- and sex-specific MDSC phenotypes. We identified significant differences regarding age and sex in MDSC expansion, transcriptome, canonical pathway activation, RNA velocity, mitochondrial metabolism, and predicted cell-cell communication after sepsis. Using drug2cell analysis of total leukocytes we also identified cohort-specific drug target profiles. These findings underscore the importance of age and sex in shaping sepsis-induced MDSC biology and suggest that personalized immunomodulatory strategies targeting MDSCs could improve sepsis outcomes.

immunology↗

bioRxiv2025

Hierarchical Coarse-to-Fine cGAN for Subtype-Specific Freezing of Gait Signal Generation

Freezing of gait (FOG), a debilitating symptom of Parkinsons disease, manifests in subtypes as shuffling, trembling, or akinesias, with occurrence and frequency varying across patients. While deep learning (DL) models show promise in FOG detection, their robustness and generalization across subtypes are limited by data scarcity and imbalances between FOG/non-FOG classes and among subtypes. To address this, we propose a subtype-aware FOG augmentation technique enabling training of DL models to perform consistently across subtypes. Specifically, we introduce Hierarchical Coarse-to-Fine conditional Generative Adversary Network (Hi-CF cGAN), a two-stage model that generates subtype-conditioned FOG-like ankle accelerations that are realistic and diverse, as verified through visualization, UMAPs, and Maximum Mean Discrepancy comparison against real signals. We evaluate its effectiveness by training CNNs for FOG detection with both general (subtype-stratified) and personalized (subtype-variant, based on patient-specific subtype composition) augmentation via Hi-CF cGAN, benchmarking against classical augmentations and baseline (no augmentation). Compared to baseline, general augmentation with Hi-CF cGAN effectively improves average detection rates of FOG, trembling FOG, and especially the previously overlooked minor subtypes, shuffling FOG (from 66.8% to 81.6%) and akinesia FOG (from 58.7% to 77.9%). These improvements exceed those of classical augmentations, demonstrating superior realism, richness, and adaptability of Hi-CF cGAN-generated data in addressing FOG/non-FOG and subtype imbalances. Personalized augmentation further enhances accuracy on targeted subtype(s) compared to general augmentation, highlighting its potential for tailored model optimization.

bioengineering↗

bioRxiv2025

Evolutionarily Conserved and Divergent Mechanisms of Dual Ca2+ Sensors in Synaptic Vesicle Exocytosis

Neurotransmitter release at the C. elegans neuromuscular junction is governed by a dual Ca{superscript 2} sensor system composed of SNT-1 and SNT-3, which are functional analogs of synaptotagmin-1 and -7 (Syt1/Syt7) in mammalian central synapses. In this study, we investigated how SNT-1 and SNT-3 mediate fast and slow neurotransmitter release through their potential interactions with the SNARE complex and their polybasic motifs. AlphaFold 3 models of SNT-1-SNARE and SNT-3-SNARE complexes accurately recapitulated the canonical Syt1 C2B-SNARE primary interface (Zhou et al., 2015, Nature) and precisely identified conserved binding residues within the C2B domains, as well as in SNAP-25 and Syntaxin, highlighting the evolutionary conservation of this interaction. Electrophysiological analyses using targeted mutagenesis demonstrated that both SNT-1 and SNT-3 require C2B-SNARE interactions and polybasic motifs within their C2 domains to drive evoked fast and slow neurotransmitter release. Notably, SNT-1 and SNT-3 exhibited differential dependence on distinct regions of the C2B-SNARE interface and their respective polybasic motifs, suggesting that Ca{superscript 2}-triggered fast and slow release operate via distinct mechanistic strategies. Furthermore, we found that SNT-1 mediates spontaneous neurotransmitter release through multiple pathways, involving not only the primary C2B-SNARE interface but also additional putative SNARE-binding interactions. Together, our findings uncover both conserved and divergent mechanisms for synaptic exocytosis regulated by the dual Ca2+ sensors in C. elegans.

neuroscience↗

bioRxiv2025

Low Dose GLP-1 Therapy Attenuates Pathological Cardiac and Hepatic Remodelling in HFpEF Independent of Weight Loss

BACKGROUND AND AIMSHeart failure with preserved ejection fraction (HFpEF) remains a therapeutic challenge. GLP-1 receptor agonists (GLP-1RAs) show clinical promise, and the prevailing hypothesis is that their benefits are primarily driven by weight loss and the downstream benefits of improved functional status. We investigated the weight loss-independent effects of low-dose GLP-1RA therapy in a clinically relevant rodent model of severe cardiometabolic HFpEF. METHODSTen-week-old male ZSF1 obese rats with spontaneous HFpEF were treated with low-dose semaglutide (30 nmol/kg twice weekly, n=6) or vehicle for 16 weeks. Comprehensive assessments included body weight, 2-D echocardiography, invasive hemodynamics, exercise capacity as well as cardiac and hepatic fibrosis and lipid deposition. The study utilized advanced multi-omics approaches, including single-cell RNA sequencing of the heart and liver, as well as cardiac, hepatic and plasma proteomics, to explore underlying mechanisms. RESULTSIn ZSF1 obese rats, low-dose semaglutide in the absence of weight loss, significantly improved cardiac function, exercise tolerance, and attenuated fibrosis in the heart and liver. Interestingly, semaglutide therapy reduced cardiac and hepatic lipid content as well as lipid droplets in cardiac myocytes and hepatocytes. Mechanistically, multi-omics analyses of cardiac and hepatic tissues revealed that semaglutide exerted these benefits by improving cardiac metabolism, interfering with pro-fibrotic and pro-hypertrophic signals, and by reducing systemic inflammation. CONCLUSIONSLow-dose semaglutide provides significant cardioprotective, hepatoprotective, and metabolic benefits in HFpEF independent of weight loss. Our findings support the investigation of lower GLP-1RA dosing in HFpEF and other cardiovascular conditions, including in non-obese patients, to expand the clinical utility of these potent drugs. Translational PerspectiveWe demonstrate that low-dose semaglutide attenuates HFpEF-mediated pathological cardiac and hepatic remodelling in HFpEF independently of the weight loss effects of GLP-1 receptor activation. Primary mechanisms are attenuated cardiac and hepatic fibrosis and reverse lipid transport. These findings provide a mechanistic basis for the direct cardiovascular actions of GLP-1RAs, revealing their potential to modulate key disease drivers like fibrosis and lipotoxicity. These data support the use of lower, better-tolerated doses of GLP-1RAs to treat HFpEF, potentially benefiting a wider range of patients, including those who are not obese or who suffer from side effects with current GLP-1 regimens.

pharmacology and toxicology↗

bioRxiv2025

Convergent utilization of APN receptor by hedgehog merbecoviruses

Dipeptidyl peptidase-4 (DPP4) and angiotensin-converting enzyme 2 (ACE2) are well-established receptors for merbecoviruses, yet the receptor usage of merbecoviruses of European and Asian hedgehogs (EriCoVs) remains unknown. Here, by testing hedgehog orthologs of known coronavirus receptors, we identify hedgehog aminopeptidase N (APN) as a functional receptor for EriCoVs. Analysis of 94 APN orthologs indicates that EriCoVs have a limited host range, primarily utilizing hedgehog APN and, to a lesser extent, APN from certain felids, shaped by specific determinants at the virus-receptor interface. Cryo-EM reveals an APN-binding mode distinct from those used by alpha- and deltacoronaviruses. Functional assays indicate that hedgehog transmembrane serine protease 2 (TMPRSS2) enhances spike activation and promotes pseudovirus entry. Neutralizing antibodies targeting RBD and APN were developed and could effectively block EriCoV pseudovirus entry and propagation. These findings reveal an unexpected convergent evolution of APN utilization among merbecovirus, establishing a foundation for risk assessment and countermeasure development. Graphic abstractConvergent utilization of hedgehog APN by EriCoVs O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=115 SRC="FIGDIR/small/676546v1_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@1ea334aorg.highwire.dtl.DTLVardef@cd53bforg.highwire.dtl.DTLVardef@352102org.highwire.dtl.DTLVardef@a1eed_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2025

Design, Optimization and Development of RIPK1 Degraders with Improved Pharmacokinetic and Pharmacodynamic Properties

The pivotal role of receptor-interacting protein kinase 1 (RIPK1) as a scaffold protein in mediating tumor resistance to immune checkpoint inhibitors (ICBs) underscores the significance of pharmacological RIPK1 degradation as a therapeutic strategy to enhance antitumor immunity. In this study, we present the design, synthesis, and evaluation of a novel series of RIPK1 degraders, derived from the optimization of the previously identified compound LD4172. Through systematic refinement of the linker, exit vector of the RIPK1 warhead, and the VHL ligand portion, we identified compound LD5097 (24b), which exhibited potent RIPK1 degradation activity across various cancer cell lines, with DC50 values of single digit nanomolar range and inducing more than 95% maximum degradation. Remarkably, LD5097 (24b) induced rapid and complete degradation of RIPK1 within 2 hours of treatment and enhanced TNF-mediated apoptosis in Jurkat cells. Furthermore, proteomic profiling unveiled the high selectivity of LD5097 (24b) in degrading RIPK1. LD5097 (24b) exhibited excellent metabolic stability and pharmacokinetic properties, characterized by low clearance, an extended half-life, and high plasma drug concentrations. Notably, a single administration of LD5097 (24b) effectively reduced RIPK1 protein levels in Jurkat xenograft tumor tissues in mice at both 6- and 24-hour post-administration. These findings underscore LD5097 (24b) as a promising RIPK1 degrader candidate, offering potent activity, favorable pharmaco-kinetic profiles, and notable pharmacodynamic effects, thereby holding significant promise in cancer immunology therapies.

pharmacology and toxicology↗

bioRxiv2025

CryoDataBot: a pipeline to curate cryoEM datasets for AI-driven structural biology

Cryogenic electron microscopy (cryoEM) has revolutionized structural biology by enabling atomic-resolution visualization of biomacromolecules. To automate atomic model building from cryoEM maps, artificial intelligence (AI) methods have emerged as powerful tools. Although high-quality, task-specific datasets play a critical role in AI-based modeling, assembling such resources often requires considerable effort and domain expertise. We present CryoDataBot, an automated pipeline that addresses this gap. It streamlines data retrieval, preprocessing, and labeling, with fine-grained quality control and flexible customization, enabling efficient generation of robust datasets. CryoDataBots effectiveness is demonstrated through improved training efficiency in U-Net models and rapid, effective retraining of CryoREAD, a widely used RNA modeling tool. By simplifying the workflow and offering customizable quality control, CryoDataBot enables researchers to easily tailor dataset construction to the specific objectives of their models, while ensuring high data quality and reducing manual workload. This flexibility supports a wide range of applications in AI-driven structural biology.

molecular biology↗

bioRxiv2025

Post-transcriptional Regulation Coordinating Transcription and Translation During Circadian Oscillation and Stress Recovery in Plants

Circadian rhythms orchestrate gene expression to align plant growth and development with daily environmental cycles. However, the post-transcriptional mechanisms that coordinate transcriptional and translational rhythmicity remain incompletely understood. To address this, we analyzed time-series transcriptome and translatome profiles in Arabidopsis seedlings, identifying 5,185 genes with rhythmicity at both levels. These genes were classified into four distinct groups based on phase and amplitude differences between transcription and translation. Circadian mRNAs with high oscillation amplitudes tended to undergo co-translational RNA decay (CTRD), whereas intronless genes displayed the lowest amplitudes, likely due to their mRNA instability and short half-lives. While CTRD and NAD capping modulate amplitude differences, intronless and circadian translational efficiency (TE) influence both phase and amplitude variations. Additionally, CTRD, NAD+ capping and circadian TE facilitate fast recovery of heat-induced genes to normal hemostasias. Collectively, our findings demonstrate that these post-transcriptional regulation shapes both synchronized and decoupled transcription and translation during plants response to diel and environmental dynamics.

genetics↗

bioRxiv2025

Genome structural plasticity and copy number dynamics shape adaptive evolution in a barley fungal pathogen

Leaf rust, caused by Puccinia hordei, is one of the most important diseases of barley globally. Here, we report the first haplotype-resolved chromosome-level genome assembly for P. hordei. To gain deeper insight and understanding of the P. hordei genome, we generated such assemblies for two Australian isolates with contrasting virulence, one collected in the 1970s and one in 2001. The two haplotype-phased and chromosome-level assemblies were used to investigate genome architecture in P. hordei and to investigate variability and evolutionary relationships of 41 virulence-divergent isolates that were collected over a 54-year period (1966-2020) in Australia. We report, for the first time in a rust fungus, evidence of a conserved chromosome, chromosome 9, which is enriched for structural variation and accessory features that imply it functions as a compartmentalized core chromosome with regions subject to rapid diversification, potentially acting as a structural hotspot in adaptive evolution in P. hordei. Clear genetic stratification into clonal and recombining lineages was uncovered, with evidence of both long-term asexual propagation and recombination. Analyses of haplotype-resolved mating-type gene phylogenies and chromosome 9 k-mer profiles confirm divergence at key loci underpinning reproductive modes, distinguishing clonally derived from sexually recombined groups. We also identified pervasive copy number variation across the P. hordei genomes, with clonal lineage-specific duplications. Consistent with this finding, the study for the first time links copy number variation of the Cyp51 gene to fungicide insensitivity. This latter discovery is highly significant as it represents the first documented case of fungicide insensitivity in a rust pathogen in which an underlying genetic mechanism has been identified. Together, these findings illuminate how genome structure, recombination, and structural variation shape the evolution and adaptation of P. hordei, providing a guidance for future surveillance and management of this pathogen.

genomics↗

bioRxiv2025

Developmental expression of risk genes implicates the age of onset for neuropsychiatric disorders

The functional effects of genetic variants associated with complex diseases exhibit pronounced spatiotemporal specificity. Although spatially resolved studies have advanced, their temporal dynamics remain poorly characterized. Here, we present an analytical framework integrating developmental gene expression with genome-wide association studies to decipher age-specific windows during which genetic variants exert their effects and to elucidate underlying mechanisms. Applying this framework to five major neuropsychiatric disorders, we uncover a fundamental principle: the peak incidence of a disease precisely coincides with the developmental window of peak expression of its associated risk genes in the prefrontal cortex. These risk windows are characterized by distinct biological processes; for instance, childhood risk for attention-deficit/hyperactivity disorder aligns with a peak in presynaptic machinery gene expression, whereas late-life risk for Alzheimers disease corresponds to heightened immune-related gene activity. Leveraging this principle of temporal convergence significantly improves the prioritization of disease genes. Our work establishes the developmental basis for the age of onset of complex diseases, providing a temporal roadmap for understanding disease mechanisms and developing age-appropriate therapeutic strategies.

genetics↗

bioRxiv2025

Structural and functional analysis of VYD222: a broadly neutralizing antibody against SARS-CoV-2 variants

Extensive mutations in SARS-CoV-2 spike protein have rendered most therapeutic monoclonal antibodies (mAbs) ineffective. However, here we describe VYD222 (pemivibart), a human mAb re-engineered from ADG20 (adintrevimab), which maintains potency despite substantial virus evolution. VYD222 received FDA Emergency Use Authorization for pre-exposure prophylaxis of COVID-19 in certain immunocompromised adults and adolescents. Here we show potent neutralization of this antibody against a broad range of emerging variants, including Omicron KP.3 and KP.3.1.1. X-ray crystal structures of VYD222 complexed with the receptor-binding domains of prototype SARS-CoV-2 and Omicron BA.5 demonstrate the binding epitope spans from the receptor binding site to the conserved CR3022 site. Notably, many of the matured residues between ADG20 and VYD222 occur outside the paratopic region. Deep mutational scanning indicates that SARS-CoV-2s ability to escape VYD222 is constrained by structural compatibility and the need to maintain receptor binding. These findings provide crucial insights into the escape-resistant neutralization of VYD222 against a broad panel of clinically relevant SARS-CoV-2 variants and offer valuable guidance for risk assessment of emergent variants.

biophysics↗

bioRxiv2025

NicheScope: Identifying Multicellular Niches and Niche-Regulated Cell States in Spatial Transcriptomics

The functional state of a cell is intrinsically linked to its local microenvironment, or cell niche, a complex milieu formed by multiple interacting cell types. Deciphering how these multicellular niches regulate cell states is fundamental to understanding tissue biology and disease mechanisms, yet remains challenging with current computational approaches. Here, we present NicheScope, a computational framework for transcriptome-wide identification and characterization of Multicellular Niches (MCNs) and their corresponding Niche-Regulated Cell States (NRCSs) from spatial transcriptomics data. NicheScope operates on the principle that a cells transcriptional state is associated with its local multicellular composition. It employs a robust statistical approach to jointly model neighborhood composition and transcriptome-wide gene expression, enabling the simultaneous discovery of MCNs, defined by specific combinations of neighboring cell types, and their associated NRCSs, characterized by distinct gene programs. We demonstrate NicheScopes power and versatility across diverse tissues and platforms, including lymph node, lung adenocarcinoma, and head and neck cancer. NicheScope reproducibly dissected established tissue structures in lymph nodes across tissue regions and platforms, uncovered clinically relevant tumor cell-associated MCNs in lung adenocarcinoma, and revealed shared and condition-specific MCNs in primary and metastatic tumors. Our results establish NicheScope as a powerful, robust, scalable, and interpretable framework for dissecting the spatial and functional organization of complex tissues, providing new insights into multicellular coordination in health and disease.

bioinformatics↗

bioRxiv2025

Ginkgolic acid attenuates e chinococcus granulosus infection-induced hepatic fibrosis by inhibiting Smad4 SUMOylation

BackgroundThe SUMOylation modification is closely linked to the progression of fibrotic diseases, yet its role in hepatic fibrosis associated with cystic echinococcosis (CE) remains unclear. This study aimed to investigate the function of SUMOylation in CE-related hepatic fibrosis and evaluate the anti-fibrotic effects and mechanisms of ginkgolic acid (GA) via regulation of the SUMOylation pathway. MethodologyPeri-lesional (PL) and adjacent normal (AN) liver tissues from CE patients were collected to examine histopathology and SUMO pathway proteins. A CE-infected mouse model was established and treated with GA to assess cyst burden, serum TGF-{beta}1 levels, hepatic fibrosis markers, and SUMO-related proteins. In vitro, macrophages and hepatic stellate cells (HSCs, LX-2 line) were stimulated with Echinococcus granulosus cyst fluid (EgCF) or TGF-{beta}1 to evaluate GAs effects on macrophage polarization (CD206/CD86), HSC activation (-SMA/PCNA), Smad4 SUMOylation, and nuclear translocation. Macrophage-HSC crosstalk was investigated via conditioned medium co-culture assays. ResultFibrosis was exacerbated in peri-lesional liver tissues of CE patients, accompanied by SUMO pathway activation. GA significantly alleviated hepatic fibrosis in CE mice and reversed SUMO pathway dysregulation. Mechanistically, GA inhibited EgCF-induced pro-fibrotic M2 macrophage polarization and blocked Smad4 SUMOylation and nuclear translocation by modulating SUMOylation. Furthermore, GA directly suppressed HSC activation and bidirectionally disrupted the pro-fibrotic crosstalk between macrophages and HSCs under EgCF stimulation, ultimately alleviating fibrosis. ConclusionThis study reveals the critical role of SUMOylation modification in CE-associated hepatic fibrosis and elucidates a novel anti-fibrotic mechanism whereby GA targets the SUMOylation-Smad4 axis to regulate the immune microenvironment. Author summaryThis study demonstrates aberrant activation of the SUMOylation pathway during hepatic fibrosis progression in cystic echinococcosis (CE), characterized by upregulated SUMO1/Ubc9 expression and downregulated SENP1 in peri-cystic liver tissue. Ginkgolic acid (GA) intervention significantly attenuated CE-associated liver fibrosis in mice, evidenced by reduced cyst volume, decreased TGF-{beta}1 levels, and suppressed expression of fibrotic markers (-SMA/COL1A1). GA concurrently reversed dysregulated SUMO pathway protein expression. Mechanistically, GA upregulates the deSUMOylating enzyme SENP1, thereby inhibiting Echinococcus granulosus cyst fluid (EgCF)-induced SUMOylation and nuclear translocation of Smad4. This blockade impedes macrophage polarization toward the pro-fibrotic M2 phenotype (CD206{downarrow}) and suppresses hepatic stellate cell (HSC) activation (-SMA/PCNA{downarrow}). Furthermore, GA disrupts the pro-fibrotic bidirectional crosstalk between HSCs and macrophages. Collectively, these findings indicate that GA ameliorates CE-induced hepatic fibrosis by targeting the SUMO-Smad4 axis to modulate the immune microenvironment, providing a novel therapeutic strategy.

molecular biology↗

bioRxiv2025

Mediator Subunit MED16 Collaborates with UBP1-TFCP2 to Control Transcriptional Activation or Repression via Promoter Positional Specificity

The Mediator complex acts as a master transcriptional co-regulator, yet the mechanisms by which its individual subunits mediate gene-specific transcription remain incompletely defined. Here, we report that the Mediator subunit MED16 physically associates with the UBP1-TFCP2 heterodimer, which controls the context-dependent transcriptional activation or repression. Biochemical purification combined with mass spectrometry validated MED16 as a bona fide interactor of UBP1-TFCP2. Integrative transcriptomic analyses demonstrated that UBP1 recruits the Mediator complex through MED16 to activate a panel of silenced genes associated with lung homeostasis, angiogenesis and cell proliferation. By contrast, MED16-UBP1 co-occupancy at the HIV-1 transcription start site (TSS) represses viral transcription and sustains HIV latency by compromising pre-initiation complex assembly. Domain-mapping experiments revealed that MED16 must integrate into the intact Mediator complex to exert either activating or repressive function. Genomic analysis uncovered a positional regulatory logic: UBP1-TFCP2 binding motifs adjacent to the TSS promote transcription, while those overlapping the TSS elicit repression. Collectively, our work identifies an MED16-UBP1 regulatory module with dual transcriptional activity and highlights this signaling axis as a potential target for HIV-1 interventions.

biochemistry↗