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Liang, X.

Publications and source records attributed to Liang, X..

At least 55 records · Page 3Linked to original sources

XChrom: a cross-cell chromatin accessibility prediction model integrating genomic sequence and cellular context

Single-cell chromatin accessibility offers unique insights into transcriptional regulation beyond gene expression. However, paired datasets of these two modalities remain relatively scarce, and existing computational models cannot simultaneously predict chromatin accessibility for unseen genomic regions and cells. Here, we present XChrom, a deep learning framework for genome-wide cross-cell chromatin accessibility prediction that integrates genomic sequence and single-cell transcriptomics-derived cell identity into a unified model. Comprehensive evaluations show that XChrom consistently outperforms existing methods in cross-region and cross-cell predictions, and uniquely enables cross-both predictions. It also supports cross-sample prediction when batch effects are properly corrected. Cross-species analyses demonstrate XChroms robust performance and its ability to capture evolutionarily conserved regulatory rules. Applied to peripheral blood mononuclear cells from COVID-19 patients, XChrom accurately identifies transcription factor activities in novel cell subpopulations and reveals pathogenesis-associated regulatory alterations. XChrom is available as an open-source Python package, facilitating single-cell transcriptional regulation research.

bioinformatics↗

Emergence of Individualized Functional Topography in the Neonatal Brain

The early postnatal period represents a critical phase for establishing the brains fundamental architecture. However, how individualized functional topography emerges and shapes long-term cognition remains unknown. Using multimodal neuroimaging data from 419 neonates, we map personalized functional topographies in the first weeks of life and reveal their association with 18-month neurocognitive outcomes. Unique and stable functional topographies are already present at birth, with interindividual variability organized along a conserved sensorimotor-to-association hierarchy. These individualized maps encode early brain maturity and robustly predict cognitive, language, and motor outcomes at 18-month of age, with predictive features concentrated at network boundaries. This functional refinement is structurally anchored by concurrent maturation in cortical myelination and sulcal depth. Preterm birth results in distinctive topographic alterations characterized by accelerated maturation of association networks. Our work establishes a foundation for precision models of early brain development and elucidates its significance for long-term neurocognitive outcomes.

neuroscience↗

Large Language Models for Accessible Reporting of Bioinformatics Analyses in Interdisciplinary Contexts

Health and life scientists frequently rely on quantitative experts to perform complex data analyses, yet interpretation of these results often becomes a bottleneck due to communication barriers across disciplines. Large Language Models (LLMs) have the potential to act as intermediaries that translate analytical outputs into accessible scientific narratives, but their ability to reliably interpret outputs from real-world biomedical data analyses across disciplines remains unclear. In this study, we investigate how state-of-the-art LLMs behave when integrated into real bioinformatics analysis workflows as report-generation assistants for interdisciplinary teams. We evaluated LLM-generated summaries using both automated and human evaluation frameworks to ensure holistic evaluation. Automated assessment employed multiple choice questions designed using Bloom's taxonomy to assess multiple levels of understanding, while human evaluation tasked scientists to score summaries for factual consistency, lack of harmfulness, comprehensiveness, and coherence. All generally produced readable and largely safe summaries, confirming their value for first-pass translation of technical analyses, however frequently misinterpreted visualisations, produced verbose summaries and rarely offered novel insights beyond what was already contained in the analytics. Our findings suggest that LLMs are best suited for easing interdisciplinary communication rather than replacing domain expertise and human oversight remains essential to guarantee accuracy, interpretative depth, and the generation of genuinely novel scientific insights.

bioinformatics↗

Iterative immunogen optimization to focus elicited responses on a conserved, subdominant influenza hemagglutinin epitope

Designing effective vaccination strategies against genetically diverse viruses, such as HIV or influenza, is hindered by the ability of these pathogens to mutate and readily evade immune responses. While these viruses contain conserved regions that cannot easily mutate without affecting viral fitness, these sites are subdominant, meaning that they are not the primary target of antibodies elicited by natural infection or current vaccines. Here, we integrated recent advances in machine learning methods for protein structure prediction and design to engineer protein immunogens that focus immune responses on a conserved, subdominant HA epitope targeted by broadly cross-reactive influenza antibodies. Iterating between computation-guided optimization and in vivo analyses generated immunogens that faithfully displayed the target epitope and redirected humoral responses toward it upon vaccination. These results provide a blueprint for applying recent protein engineering approaches to immunogen design and may inform the development of broadly protective influenza vaccines.

immunology↗

Hemin Inhibits the Activation of STING in Macrophages by Inducing HO-1, Promoting Endometriosis Development

IntroductionEndometriosis (EMS) is an estrogen-dependent inflammatory disorder characterized by immune dysregulation. This condition profoundly affects the quality of life and reproductive health of nearly 200 million women of reproductive age worldwide and poses significant clinical challenges due to lack of diagnosis tools and effective treatment. Peritoneal macrophages play a central role in promoting the initiation and progression of EMS. Bioinformatics studies have indicated that the STimulator of INterferon Gene (STING) was downregulated in the macrophages in EMS, and this influenced their polarization and functional. However, the specific contribution of STING pathway alterations to EMS pathogenesis remains unclear. MethodsWe integrated scRNA-seq data from EMS patients and healthy controls-including lesions, eutopic endometrium, non-lesional tissue, and peritoneal fluid from EMS patients and healthy controls(n = 19,291 total samples)-to analyze macrophage STING expression and function. Mouse EMS model was generated by injecting uterus fragments into WT or STING-/- mice. Peritoneal fluid was collected and macrophage proportions and subtypes were assessed via flow cytometry. Macrophages were depleted in STING-/- mice prior to EMS induction to evaluate their role in disease progression. In vitro, hemin was used to treat macrophages to investigate how heme oxygenase-1 (HO-1) modulates the STING pathway, assessed through immunoblotting, co-immunoprecipitation, ELISA, and multiplex immunofluorescence. ResultsBioinformatic analysis revealed that macrophages within the EMS lesions are primarily derived from peritoneal macrophages and exhibit decreased STING expression, which correlated negatively with HO-1. STING-/- mice developed more numerous and larger EMS lesions, accompanied by a decreased proportion of large peritoneal macrophages and an increase in small peritoneal macrophages. A marked elevation in M2-type macrophages within the lesions was detected in STING-/- mice. In vitro, hemin-induced HO-1 suppressed STING pathway activation in macrophages. Mechanistically, HO-1 inhibited the translocation of STING from the endoplasmic reticulum to the Golgi, thereby suppressing STING signaling and facilitating EMS. ConclusionMacrophages are essential for lesion formation in STING-/- mice. In vitro, hemin promotes EMS progression via HO-1 - mediated suppression of the STING pathway. Our findings identify the heme-HO-1-STING axis as a key immunomodulatory pathway in EMS and suggest its potential as a therapeutic target. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=157 SRC="FIGDIR/small/683839v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@6901beorg.highwire.dtl.DTLVardef@1f18d44org.highwire.dtl.DTLVardef@1716f6forg.highwire.dtl.DTLVardef@4ae22d_HPS_FORMAT_FIGEXP M_FIG Graphical abstract (Created in BioRender.com) Retrograde menstruation leads to the accumulation of heme in the peritoneal cavity, which upregulates HO-1 expression in peritoneal macrophages. HO-1 inhibits the translocation of STING from the endoplasmic reticulum to the Golgi apparatus in macrophages, thereby suppressing the STING pathway and promoting the development and progression of EMS. The progression of EMS, in turn, reinforces this mechanism, creating a self-sustaining vicious cycle. C_FIG

immunology↗

Predicting enhancer-gene links from single-cell multi-omics data by integrating prior Hi-C information

Enhancers play an important role in transcriptional regulation by modulating gene expression from distal genomic locations. Although single-cell ATAC and RNA sequencing (scATAC/RNA-seq) data have been leveraged to infer enhancer-gene links, establishing regulatory links between enhancers and their target genes remains a challenge due to the absence of chromatin conformation information. Here, we present SCEG-HiC, a machine learning method based on weighted graphical lasso, which decodes enhancer-gene links from single-cell multi-omics data by integrating bulk average Hi-C as prior knowledge. Comprehensive evaluation across ten single-cell multi-omics datasets from both humans and mice demonstrates that SCEG-HiC outperforms existing single-cell models, regardless of using paired scATAC/RNA-seq or scATAC-seq data alone. Application of SCEG-HiC to COVID-19 datasets illustrates its capacity to more reliably reconstruct gene regulatory networks underlying disease severity, and elucidate functional associations between non-coding variants and their putative target genes. SCEG-HiC is freely available as an open-source and user-friendly R package, facilitating broad applications in regulatory genomics research.

bioinformatics↗

TopoLa: A Universal Framework to Enhance Cell Representations for Single-cell and Spatial Omics through Topology-encoded Latent Hyperbolic Geometry

Recent advances in cellular research demonstrate that scRNA-seq characterizes cellular heterogeneity, while spatial transcriptomics reveals the spatial distribution of gene expression. Cell representation is the fundamental issue in the two fields. Here, we propose Topology-encoded Latent Hyperbolic Geometry (TopoLa), a computational framework enhancing cell representations by capturing fine-grained intercellular topological relationships. The framework introduces a new metric, TopoLa distance (TLd), which quantifies the geometric distance between cells within latent hyperbolic space, capturing the networks topological structure more effectively. With this framework, the cell representation can be enhanced considerably by performing convolution on its neighboring cells. Performance evaluation across seven biological tasks, including scRNA-seq data clustering and spatial transcriptomics domain identification, shows that TopoLa significantly improves the performance of several state-of-the-art models. These results underscore the generalizability and robustness of TopoLa, establishing it as a valuable tool for advancing both biological discovery and computational methodologies.

bioinformatics↗

Systemic Inflammation Modulates Clearance and drives Extra-Hepatic Distribution of Extracellular Vesicles

Extracellular vesicles (EVs) are promising vehicles for targeted therapeutic delivery, capable of encapsulating and transporting biomolecules to specific cells and tissues. Given that inflammation is central to many acute and chronic diseases, understanding EV biodistribution under inflammatory conditions is essential for therapeutic optimization. This study examines how acute systemic inflammation influences EV biodistribution, clearance, and plasma half-life, with a focus on the role of macrophages and their polarization states. Using a lipopolysaccharide (LPS)-induced inflammation model in wild-type mice and bioluminescent and fluorescent labelling of EVs, we observed that inflammation extends the plasma half-life of EVs by over 600-fold within 2 hours and 900-fold at 24 hours post-administration, leading to significant enrichment in inflamed organs, particularly the liver and spleen. Enhanced accumulation in specific tissues translated to increased targeting of immune- and epithelial cells within those organs, with notable uptake by hepatocytes in the liver. This prolonged half-life was attributed to the altered EV protein corona in inflamed tissues, which facilitates cellular association. These findings underscore the complex dynamics between EVs and immune cells under inflammatory conditions and provide critical insights for advancing EV-based therapies in chronic inflammatory diseases.

bioengineering↗

Agropyron cristatum genome provides a new insight for wheat improvement with wild relatives

Exploring novel genetic variation for target traits is crucial for advancing wheat breeding and genetic improvement. Since 1990, we have been transferring genes from Agropyron cristatum, a promising wild relative genetic resource featuring robust spike morphology and stress tolerance, into common wheat by distant hybridization. To efficiently harness A. cristatum genes, we de novo assembled a 25.62-Gb high-quality genome of an autotetraploid accession Z559 with 28 chromosomes, and uncovered its specific genome features and an extensive repertoire of genes associated with yield and resistance to abiotic and biotic stresses. We systematically characterized A. cristatum genome introgressions by resequencing 431 wheat-A. cristatum derivatives and cloned the gene AcGNS1, which functions in the regulation of grain number per spike in wheat. Subsequently, we developed an optimized genome-selection model for wheat-A. cristatum breeding derivatives, enabling the rapid selection of new potential varieties. These findings demonstrate a genomic breeding strategy for leveraging novel genetic resources of wild relatives and advancing wheat improvement.

genomics↗

MAPseq2: a sensitive and cost-effective barcoded connectomics method

The barcoded connectomics tool MAPseq enables highly multiplexed projection mapping of individual neurons by translating neuroanatomy into a format solvable by DNA sequencing. Here we present MAPseq2, a user-friendly protocol with up to [~]10-fold increased sensitivity compared to the current state of the art and [~]10-fold decreased cost. As MAPseq workflows are used across a range of barcoded connectomics methods, including BARseq, BRICseq, and ConnectID, all improvements in MAPseq2 directly transfer to these technologies.

neuroscience↗

Immune pathways and perinatal environmental exposures contribute to epigenetic gestational age prediction and acceleration

DNA methylation (DNAm), capturing biological gestational age (GA) and epigenetic gestational age acceleration (EGAA), can be modified by environmental exposures. The Asthma&Allergy array is a new DNAm array developed with content focused on asthma and allergy loci. The association between content on the Asthma&Allergy array and chronological GA and EGAA has not been evaluated alone or in the context of perinatal exposures. We performed an epigenome wide association study(EWAS) based on chronological GA at single CpG sites and regions. We further constructed a multi-CpG site methylation model to predict chronological GA in cord blood from 391 newborn children from a Detroit-based birth cohort. Associations between perinatal environmental factors with GA, epigenetic gestational age (EGA), and EGAA were assessed. We identified 2,435 CpG sites associated with chronological GA. HLA class II (HLA-DRB1,HLA-DQB1,HLA-DRB6) were the most significantly associated with chronological GA. Our multi-CpG site model attained predictive accuracy (cross-validated Pearsons correlation=0.75) comparable to other EGA methods. Using genes implicated in region-based analyses (n=395 regions), the pathways most significantly enriched with chronological GA-associated CpGs included T helper 1(Th1) and 2(Th2) activation, macrophage classical activation, and IL10 signaling, which were also enriched in at least one of the other published epigenetic clocks. In multi-exposure models, prenatal indoor pet exposure and unplanned C-section were associated with EGA deceleration, while infants first-born status was associated with EGAA. Our findings highlight enrichment for T cell modulated pathways and antigen presentation as biological processes enriched in chronological GA, as well as novel perinatal factors that may impact EGAA.

genomics↗

Population-specific brain charts reveal Chinese-Western differences in neurodevelopmental trajectories

Human brain charts provide unprecedented opportunities for decoding neurodevelopmental milestones and establishing clinical benchmarks for precision brain medicine 1-7. However, current lifespan brain charts are primarily derived from European and North American cohorts, with Asian populations severely underrepresented. Here, we present the first population-specific brain charts for China, developed through the Chinese Lifespan Brain Mapping Consortium (Phase I) using neuroimaging data from 43,037 participants (aged 0-100 years) across 384 sites nationwide. We establish the lifespan normative trajectories for 296 structural brain phenotypes, encompassing global, subcortical, and cortical measures. Cross-population comparisons with Western brain charts (based on data from 56,339 participants aged 0-100 years) reveal distinct neurodevelopmental patterns in the Chinese population, including prolonged cortical and subcortical maturation, accelerated cerebellar growth, and earlier development of sensorimotor regions relative to paralimbic regions. Crucially, these Chinese-specific charts outperform Western-derived models in predicting healthy brain phenotypes and detecting pathological deviations in Chinese clinical cohorts. These findings highlight the urgent need for diverse, population-representative brain charts to advance equitable precision neuroscience and improve clinical validity across populations.

neuroscience↗

ERM proteins regulate the shape and number of Endoplasmic Reticulum-Plasma Membrane Junctions in neurons

Endoplasmic Reticulum (ER) - Plasma Membrane (PM) Junctions (EPJs) are specialized contact sites between ER membrane and the inner leaflet of PM. These junctions are critical for lipid exchange and Ca2+ signaling. In excitable cells like neurons and muscle, EPJs further modulate membrane excitability by regulating Ca2+ homeostasis. The mechanisms controlling EPJ abundance and morphology remain poorly understood. Using in vivo fluorescence imaging and electron microscopy of C. elegans neurons, we showed that EPJs form discrete, patch-like structures distributed across the soma. Through a forward genetics screen, we identified two conserved ERM (Ezrin-Radixin-Moesin) proteins, FRM-4 and FRM-1, as key regulators of EPJ shape and abundance. Both proteins localize to EPJs and exhibit liquid-liquid phase separation properties (LLPS). in vitro, purified FRM-4 binds to FRM-1, and together bundle filamentous actin. However, their presence in LLPS condensates and actin-bundling activity are mutually exclusive. In vivo, F-actin cables surround--but do not penetrate--EPJs, where FRM proteins are enriched as phase-separated condensates. Loss of FRM-4, FRM-1, or disruption of F-actin led to increased mobility of EPJs that fused into fewer but enlarged junctions. Together, our findings demonstrate that FRM-4 and FRM-1 control EPJ morphology by organizing peri-junctional F-actin networks, thereby restricting EPJ mobility and fusion.

cell biology↗

Nanopore Sequencing Unveils Somatic Structural Variations as Biomarkers in Laryngeal squamous cell carcinoma Genomes

Laryngeal squamous cell carcinoma (LSCC) is an aggressive cancer with poor quality of life, largely due to the absence of reliable molecular biomarkers for early diagnosis and prognosis. While somatic structural variations (SVs) have been documented in LSCC, conventional short-read sequencing approaches are inherently limited in detecting of large-scale somatic SVs, which are critical to understanding tumorigenesis. Here, we presented SomaGauss-SV, a somatic SVs detection workflow leveraging nanopore long-read sequencing data. Benchmarking against five paired tumor cell line datasets showed SomaGauss-SV consistently achieves a balanced high precision and recall. SomaGauss-SV applied to 15 paired LSCC tumor-blood samples uncovered a comprehensive SVs landscape and a significant positive correlation between somatic deletion burden and smoking intensity. Furthermore, a high-frequency somatic simple repeat expansion was identified in 20/27 (74.1%) of LSCC patients, upregulating the expression of genes TP53BP2 and FBXO28 through spatial proximity. These findings underscore the potential of long-read sequencing and SomaGauss-SV in uncovering previously unexplored genomic rearrangements in LSCC, providing valuable resources for biomarker discovery.

bioinformatics↗

DAPL1 deficiency impairs autophagy in retinal pigment epithelium to drive age-dependent retinal pathologies

Age-related retinopathy, primarily comprising age-related macular degeneration (AMD), is a major cause of irreversible blindness in the elderly population worldwide. Although its precise mechanisms remain incompletely understood, autophagy deficiency in retinal pigment epithelium (RPE) cells has been associated with AMD in patients; however, the regulatory pathways involved are not fully elucidated. In this study, we report that deficiency in the Dapl1 gene inhibits RPE cell autophagy and leads to age-dependent retinal pathologies in mice. Specifically, 18-month-old Dapl1-/- mice manifest age-related retinal dysfunction and structural abnormities, including increased retinal stress, photoreceptor/RPE cell damage, lipid aggregates and microglial activation. Furthermore, we demonstrate that autophagy is impaired in the RPE cells of Dapl1-/- mice, while overexpression of DAPL1 in RPE cells enhances autophagy activity. Mechanistically, we elucidate that DAPL1 suppresses the expression of E2F1 and c-MYC, which consequently downregulates mTOR and upregulates ATG16 and Beclin1 expression via DAPK1 in RPE cells, thereby promoting autophagy. Taken together, our findings demonstrate that DAPL1 acts as a novel regulator of autophagy in RPE cells, and its deficiency increases susceptibility to age-dependent retinal pathologies in mice.

molecular biology↗

Heterogeneity of CD8αα intraepithelial lymphocytes is transcriptionally conserved between TCRαβ and TCRγδ cell lineages.

Intestinal intraepithelial lymphocytes (IELs) are a versatile population of immune cells with both effector and regulatory roles in gut immunity. Although this functional diversity is thought to arise from distinct IEL subpopulations, the heterogeneity of TCR{beta}+ and TCR{gamma}{delta}+ IELs have not been well-characterized. Using scRNAseq, we identified CD8+ T cell subsets with memory-like (Tcf7) and effector-like (Prdm1) profiles in both TCR{beta}+ and TCR{gamma}{delta}+ IELs. Using CD160 and CD122 as markers of memory-like and effector-like cells, respectively, we found that while effector-like cells dominated the small intestine, memory-like IELs were more prevalent in the large intestine, suggesting a functional specialization of immune responses along the gut. Further transcriptional analysis revealed shared profiles between TCR{beta}+ and TCR{gamma}{delta}+ small intestinal IEL subsets, suggesting conserved functional roles across these populations. Finally, our analysis indicated that TCR{beta}+ memory-like IELs arise from Tcf7 double-negative (DN) precursors, and that effector-like IELs subsequently differentiate from the memory-like population. In contrast, TCR{gamma}{delta}+ IELs appear to originate from two distinct precursor populations, one expressing Tcf7 and the other Zeb2, indicating the presence of parallel developmental pathways within this lineage. Overall, our findings reveal that both TCR{beta}+ and TCR{gamma}{delta}+ cells contain memory-like and effector-like subsets, which may contribute to the functional heterogeneity of IELs.

immunology↗

Aerobic glycolysis and lactate regulate histone H3K18Lactylation occupancy to fine-tune gene expression in developing and mature retina

High aerobic glycolysis in retinal photoreceptors, as in cancer cells, is implicated in mitigating energy and metabolic demands. Lactate, a product of glycolysis, plays a key role in epigenetic regulation through histone lactylation in cancer. Here, we demonstrate that increased ATP production during retinal development is achieved primarily through augmented glycolysis. Histone lactylation, especially H3K18La, parallels enhanced glycolysis and lactate in developing retina and in retinal explants. Multi-omics analyses, combined with confocal imaging, reveal the localization of H3K18La near H3K27Ac in euchromatin at promoters of active retinal genes. H3K18La and gene expression are also concordant with glucose metabolism in retinal explants. Evaluation of accessible chromatin at H3K18La marked promoters uncovers an enrichment of GC-rich motifs for transcription factors of SP, KMT and KLF families, among others, indicating specificity of H3K18La-mediated gene regulation. Our results highlight glycolysis/lactate/H3K18La as a regulatory axis in fine-tuning gene expression in developing and mature retina.

molecular biology↗

Efficient delivery of mRNA-LNPs in primary and secondary liver cancer

Primary liver cancer is the sixth most prevalent cancer globally and is often diagnosed late, when treatment options are limited. Secondary liver cancer, arising from metastasis of other cancers to the liver, is a common complication of advanced solid cancers and a significant cause of cancer-related morbidity and mortality. Existing treatment options for advanced primary and secondary liver tumours have limited efficacy and new treatment modalities have the potential to improve patient outcomes. mRNA therapeutics are readily delivered to the healthy liver after systemic administration, but their uptake and expression within liver tumours is unclear. Here we show that intravenous delivery of mRNA-LNPs efficiently transfects virtually all hepatocytes in healthy, fibrotic, and cirrhotic liver, and also many cells of spontaneous hepatocellular carcinomas in situ. Delivery of mRNA is also possible to xenograft models of both primary and secondary liver cancer, albeit with attenuated protein expression relative to the normal liver. These findings demonstrate the potential for systemically delivered mRNA-LNP therapies for liver disease and cancer.

molecular biology↗