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Biology subjects

Meng, D.

Publications and source records attributed to Meng, D..

At least 19 recordsLinked to original sources

Cellular context shapes the transcriptomic impact of somatic variants

Somatic SNVs are commonly prioritized by recurrence or sequence annotation, leaving the molecular consequences of private variants unresolved. We developed PrismSNV and Ligo-Seq, a single-cell full-length transcriptome sequencing platform, to quantify transcriptomic displacement associated with within-cell SNV-state toggling. Across 26 samples from three cancer types, more than 60% of candidate SNVs showed significant cell-type-specific displacement with over 30% variation in magnitude. Sequence-based deleteriousness was poorly aligned with cellular displacement, and fewer than 3% of top-displacement SNVs across six tumor types were catalogued in ClinVar. Displacement was strongest in transcriptionally plastic, less differentiated states. Analysis of 655,349 CD4+ T-cell transcriptomes further showed that SNV-gene associations changed in magnitude and sometimes direction during activation. Lack of recurrence or clinical annotation does not imply transcriptomic inertness; variant impact is shaped by cellular context rather than sequence alone, establishing the variant-cell pair as a critical unit for interpreting somatic variation.

genetics↗

Harnessing Human Immune Organoid model for Systemic and Comparative Analysis of Clinically Vaccine Adjuvants

Effective vaccine adjuvants are crucial for eliciting strong, specific, and long-lasting adaptive immune responses. However, traditional vaccine and adjuvant development is often hindered by prolonged animal testing, reliance on singular evaluation metrics, and batch variability, limiting the comparative analysis of immune responses induced by different adjuvants. To our knowledge, systematic adjuvant-focused analysis in human immune organoids remains limited, particularly across distinct antigen-conditioned immune baselines. Here, we established a matrix supported human tonsil immune organoid (M-hTIO) platform, derived from tonsil tissue for systemic adjuvant evaluation. Within 2 days, the platform replicated key germinal center (GC) features, with the potential for antigen-specific antibody production and plasmablast differentiation. Dynamic GC formation and T-B cell interactions were tracked using light-field imaging. Notably, IL-21 significantly accelerates GC-like remodeling and enhanced immune responses. Employing bulk cell transcriptomics we systematically analyzed early immune signatures and prolonged adaptive responses induced by five clinical-grade adjuvants (Alum, MnJ{beta}, AddaSO3, R848, ODN 1018) paired with influenza HA and SARS-CoV-2 RBD antigens across only adjuvant, weak and strong memory backgrounds. By integrating early and prolonged response phases, M-hTIO captured complementary dimensions of adjuvant activity, distinguishing rapid immune activation from sustained adaptive remodeling. Importantly, early activation signatures and prolonged adaptive remodeling provided complementary information, highlighting the value of temporally resolved adjuvant evaluation. AddaSO3 showed a consistent activity pattern across early and prolonged response phases, supporting both rapid immune activation and sustained adaptive remodeling. Moreover, our findings reveal shared/exclusive signaling pathways and gene networks. These results represent systematic and comparative analysis of clinically tested vaccine adjuvants in a human model, paving the way for high-throughput systems vaccinology research.

immunology↗

Bacillus velezensis-derived muropeptide promotes growth of zebrafish via NOD2-mediated induction of IGF1 signaling

The role of gut microbiome in regulating vertebrate metabolism has been well-recognized. However, the effects of gut bacteria on growth have been less studied. Bacillus is a prevalent genus in the gut microbiota of human and animals. In this study, the effect of gut-derived Bacillus velezensis T23 on growth was investigated in zebrafish. B. velezensis T23 improved the growth of zebrafish and promoted IGF1 production in the liver and muscle, with a concomitant activation of the AKT/mTOR signaling pathway. The growth-promoting effect of B. velezensis T23 was not dependent on lipopeptides and polyketides. Cell wall peptidoglycan isolated from B. velezensis T23, as well as muramyl dipeptide (MDP), was sufficient to stimulate IGF1 signaling and growth. Further, the effect of B. velezensis T23 on growth and IGF1 production was abrogated in nod2-/- zebrafish, confirming that B. velezensis T23 promoted growth via MDP-NOD2 signaling. Gut transcriptomic analysis indicated that B. velezensis T23 promoted renewal and differentiation of intestinal cells, suggesting an involvement of gut-liver axis in the effect of B. velezensis T23 on systemic IGF1 production. Together, our results revealed an effect of gut Bacillus-derived muropeptide on growth via NOD2-IGF1 signaling, and provided novel mechanistic insights in the beneficial effect of Bacillus spp. as probiotics.

microbiology↗

Endothelial MRG15 Is a Mechanosensitive Suppressor of Atherosclerosis

Disturbed blood flow induces early endothelial inflammation in atherosclerosis, yet the precise mechanisms of endothelial sensing of disturbed flow remain incompletely understood. In this study, we integrated proteomic profiling of human endothelial cells (ECs) subjected to disturbed flow with coronary artery disease risk related genes from large-scale genome-wide association studies (GWAS). We identified mortality factor 4-like protein 1 (MORF4L1, also called MRG15) as a critical modulator in the pathogenesis of atherosclerosis induced by disturbed flow. We show that the expression of MRG15 is markedly reduced in ECs of human aortic atherosclerotic plaques, as well as in ECs exposed to disturbed flow in mouse carotid artery and in cultured human umbilical vein endothelial cells (HUVECs). Endothelial-specific deletion of Mrg15 significantly worsened, while its overexpression attenuated endothelial inflammation and atherosclerotic lesions in turbulent blood flow- or Western diet-induced mouse atherosclerosis model. Single-cell transcriptomics showed that Mrg15 deficiency increased endothelial inflammation and intercellular adhesion molecule 1 (Icam1) expression, and enhanced integrin-mediated adhesion pathways. Mechanistically, MRG15 facilitated the recruitment of enhancer of zeste homolog 2 (EZH2) to maintain repressive histone H3 lysine 27 trimethylation (H3K27me3) marks on the promoters of ICAM1 and integrin subunit alpha 5 (ITGA5). Disturbed blood flow rapidly led to an elevation of protein neddylation, which subsequently induced neddylation-dependent degradation of MRG15 within endothelial cells. This degradation of MRG15 alleviated the transcriptional repression of ICAM1 and ITGA5, thereby enhancing monocyte adhesion to ECs. These findings highlight endothelial MRG15 as a mechanosensitive suppressor of atherosclerosis induced by disturbed flow. Consequently, MRG15 emerges as a promising novel therapeutic target for atherosclerosis.

molecular biology↗

Telomere-to-telomere gap-free and phased genome assembly reveals post-allopolyploidization subgenomic diversification of tobacco centromeres

Common tobacco (Nicotiana tabacum) is an economically important crop worldwide whose allotetraploid genome sequence remains incompletely assembled. We report a 4.2Gb telomere-to-telomere gap-free N. tabacum reference genome phased into two subgenomes (subS/subT) , revealing differential evolutionary trajectories between two subgenomes marked by a rapid divergence in paternal T-genome, especially for heterochromatic centromeric regions. To understand the evolutionary dynamics of tobacco centromeres following polyploidization, we characterize the centromere architecture in tetraploid N. tabacum and its diploid progenitors, demonstrating clear subgenomic diversification and repositioning of centromeres during speciation and allopolyploidization. These findings enrich our knowledge on centromere paradox in polyploid genomes.

genomics↗

LINKER-Pred: A Public Web Server for Accurate Prediction of Disordered Flexible Linkers in Proteins

Disordered Flexible Linkers (DFLs) are unstructured regions that play critical roles in inter-domain communication and multivalent protein interactions. Despite their biological significance, the accurate identification of DFLs remains challenging due to limited experimental annotations and sparsity of dedicated prediction tools. Here we introduce LINKER-Pred, a publicly available web server featuring two convolutional neural network-based predictors trained on a novel large-scale dataset of linkers connecting folded domains (DLD dataset) and DisProt linkers. LINKER-Pred2 combines ProtTrans and MSA-Transformer embeddings within an ensemble CNN framework, achieving state-of-the-art performance on CAID2 and CAID3 benchmarks. LINKER-Pred-Lite excludes MSA-based features, improving speed while maintaining competitive predictive accuracy. LINKER-Pred predictors offer robust residue-level DFL predictions directly from sequence, providing a scalable solution for DFL annotation across proteomes. The LINKER-Pred web server and associated resources are freely available at https://linkerpred.chemeslab.org/, offering the research community an accessible tool for studying protein disorder and modularity.

bioinformatics↗

MolUNet++: Adaptive-grained Explicit Substructure and Interaction Aware Molecular Representation Learning

Molecular representation learning is a critical task in AI-driven drug development. While graph neural networks (GNNs) have demonstrated strong performance and gained widespread adoption in this field, efficiently extracting and explicitly analyzing functional groups remains a challenge. To address this issue, we propose MolUNet++, a novel model that employs Molecular Edge Shrinkage Pooling (MESPool) for hierarchical substructure extraction, utilizes a Nested UNet framework for multi-granularity feature integration, and incorporates a substructure masking explainer for quantitative fragment analysis. We evaluated MolUNet++ on tasks including molecular property prediction, drug-drug interaction (DDI) prediction, and drug-target interaction (DTI) prediction. Experimental results demonstrate that MolUNet++ not only outperforms traditional GNN models in predictive performance but also exhibits explicit, intuitive, and chemically logical interpretability. This capability provides valuable insights and tools for researchers in drug design and optimization.

bioinformatics↗

The evolution of high-order genome architecture revealed from 1,000 species

Spatial genome organization plays a crucial regulatory role, but its evolution remains unknown. Leveraging Hi-C data from 1,025 species, we trace the evolutionary trajectories of 3D genome, through two higher-order architectures, global folding (spatial organization of karyotype) and checkerboard (chromatin compartments). Early life forms, including prokaryotes and unicellular eukaryotes, mostly display random configurations. Through the evolution of plants, global folding became the prominent architecture with eudicots and remained dominant. Animals, however, progressively developed stronger checkerboard throughout vertebrate and invertebrate evolution, and even during early embryogenesis, suggesting a conserved gene co-regulation mechanism. In contrast, plants prefer linear gene clusters over checkerboard. Both strategies of gene arrangement reinforce the biological principle structure determines function: divergent evolutionary paths converge on architectural solutions to meet the greater regulatory demands.

evolutionary biology↗

Gap-free genomes and transcriptomes uncover race-specific effectors in watermelon wilt pathogen Fusarium oxysporum f. sp. niveum

Watermelon (Citrullus lanatus L.) is one of the worlds most economically important fruit crops, yet it is susceptible to devastating diseases such as vascular wilt caused by Fusarium oxysporum f. sp. niveum (Fon), with limited effective control measures. Fon evolves rapidly in the field to overcome host resistance and global watermelon production is constantly threatened by new pathogenic races. High-quality genomic resources are key to understanding the molecular mechanisms underlying Fon virulence evolution for disease management. Here, we de novo assembled and annotated gapless genomes of three physiological races of Fon (race 1, 2, and 3), and dissected the mechanisms behind their distinctive virulence through comparative genomics and transcriptomics. Whole-genome alignments identified core and accessory chromosomes in Fon where each race carried a unique set of accessory chromosomes or regions. Comparative transcriptomics of Fon infection revealed distinctive temporal patterns of gene expression even among core gene families, particularly those related to cell wall degradation enzymes. Effectoromic prediction and comparative analysis in three gap-free genomes identified 13 race-specific effectors (RSEs) in FonR3, one (FonRSE1) of which was a critical virulence factor of FonR3 on watermelon as demonstrated via functional experiments. The gap-free genome assemblies and annotations, and the RSEs are valuable resources for studying Fon pathobiology and genome evolution, adding in the design of improved disease control strategies.

genomics↗

Dietary quorum quenching AHL lactonase impairs the adaptation of commensal bacterium to host innate immunity

Quorum sensing (QS) is the communication system of bacteria that depends on QS signals. Quorum quenching (QQ) enzymes degrade QS signals and are promising alternatives of antibiotics to treat bacterial infections. Here, we found that dietary QQ N-acyl homoserine (AHL) lactonase led to microbiota dysbiosis in zebrafish, with reduction of Aeromonas and enrichment of Plesiomonas. Through gnotobiotic zebrafish colonized with a minimal microbiota, we found that QQ-mediated microbial alteration relies on host Myd88 signaling and neutrophil elastase. Mechanistically, quorum quenching increased the susceptibility of commensal Aeromonas to host neutrophil elastase by impairing bacterial lateral flagellar system, leading to reduced colonization of Aeromonas and subsequent enrichment of Plesiomonas due to ecological competition of the two species. Together, we found that dietary QQ lactonase led to microbiota alteration by impairing the adaptation of commensal Aeromonas to host innate immunity, which provided novel insight in the role of quorum sensing in host-microbiota interaction.

microbiology↗

Title: Cell-autonomous and non-cell-autonomous effects of TRIM72 on ALS disease progression

Dysfunction of RNA-binding proteins, including TDP-43 and FUS, has been associated with amyotrophic lateral sclerosis (ALS); however, the underlying mechanisms are largely unknown. Here, we reported that a neuronal upregulation of TRIM72 (Tripartite Motif Containing 72) in FUS mutation knockin ALS models slows disease progression. TRIM72 interacts with Commander, a protein complex for recycling of membrane proteins, facilitating membrane repair and antioxidation. Exosomal TRIM72 is detected in ALS patient cerebrospinal fluid (CSF) and extracellular application of exosomal TRIM72 protects cell from membrane damage. In a sporadic ALS cohort, CSF TRIM72 level associates ALS disease progression. AAV-mediated neuronal expression of TRIM72 slows down the disease progressions in ALS models and in an ALS patient without adverse effects over a year treatment course. Taken together, our results suggest a universal neuronal protection of a TRIM family protein in cell-autonomous and non-cell-autonomous manners in ALS.

neuroscience↗

Engineered mitochondrial A-to-G editors with enhanced efficiency and targeting scope

Mitochondrial base editing is a powerful technology, but the current A-to-G mitochondrial DNA (mtDNA) base editors are reluctant to achieve high efficiency, which is critical for mtDNA engineering. Through laboratory evolution, TadA-8e variants were discovered with substantially increased activity and expanded targeting compatibility, especially for previously unfavorite sequence contexts, when applied to both nuclear and mitochondrial ABEs. Further engineering of the mtDNA editors (eTd-mtABEs) dramatically reduced both DNA and RNA off-targeting effects and enhanced strand-selective A-to-G editing with substitution of DddA to DNA nickases. Moreover, the eTd-mtABEs induced up to 145-fold editing frequencies compared to previous mtDNA adenine base editors in rat cells, and installed targeted mutations in all injected rat embryos with up to 74% efficiency in founders, resulting generation of SNHL and Leigh syndrome models with severe defects. It suggests that eTd-mtABEs are promising mtDNA engineering technology for basic research and for translational studies. HighlightsO_LIEngineered TadA variants enhance nuclear and mitochondrial ABE activity in all sequence contexts. C_LIO_LIAdditional mutations in eTd-mtABEs further minimize both DNA and RNA off-targeting effects. C_LIO_LIEngineered TadA variants are compatible to DNA nickase assisted strand-selective mtDNA editing. C_LIO_LIeTd-mtABEs enable highly efficient generation of rat mtDNA disease models with severe phenotypes. C_LI

bioengineering↗

PUNCH2: explore the strategy for Intrinsically Disordered Protein predictor

Intrinsically disordered proteins (IDPs) lack stable three-dimensional structures, which poses significant challenges for their computational prediction. This study introduces PUNCH2, a novel approach for predicting intrinsically disordered regions (IDRs) in proteins. We address key issues such as the scarcity of comprehensive IDR databases, effective feature extraction, and robust model architecture. By integrating sequences from experimental PDB datasets and fully disordered DisProt sequences for training, PUNCH2 achieves superior prediction accuracy. Various sequence embeddings, including One-Hot, MSA-based, and PLM-based methods, were evaluated, with ProtTrans-based embeddings showing the best performance. The optimal model architecture features multiple convolutional layers, enhancing predictive confidence. PUNCH2 and its lighter variant, PUNCH2-light, demonstrate high efficiency and accuracy in benchmarking against top predictors on the CAID2 dataset, offering promising tools for advancing IDP research and understanding.

bioinformatics↗

The complete genome of lettuce reveals centromere landscape and empowers breeding

Lettuce (Lactuca sativa L.) is a globally grown vegetable crop as the most popular salad ingredient. Lettuce breeding is crucial to enhancing yield, nutrition and disease resistance, but impeded by lacking a high-quality genome resource. In addition, the released genomes remain fragmented (with hundreds of gaps) and incomplete with omitting pivotal centromeres and telomeres. Here, we report a 2.59 Gb complete telomere-to-telomere (T2T) genome assembly for lettuce. T2T genome analysis revealed the unique genetic and epigenetic architectures of centromere repeats dominated by retrotransposons and satellites. The complete genome and annotation facilitate the identification of candidate disease resistance (NLR) genes induced during grey mold infection. The genomic resources, and biological insights into genetic and epigenetic landscape of centromeres not only advance lettuce research and breeding, but also propel the biology and evolution of centromeres across plant kingdom.

genomics↗

scCaT: an explainable capsulating architecture for sepsis diagnosis transferring from single-cell RNA sequencing

Sepsis is a life-threatening condition characterized by an exaggerated immune response to pathogens, leading to organ damage and high mortality rates in the intensive care unit. Although deep learning has achieved impressive performance on prediction and classification tasks in medicine, it requires large amounts of data and lacks explainability, which hinder its application to sepsis diagnosis. We introduce a deep learning framework, called scCaT, which blends the capsulating architecture with Transformer to develop a sepsis diagnostic model using single-cell RNA sequencing data and transfers it to bulk RNA data. The capsulating architecture effectively groups genes into capsules based on biological functions, which provides explainability in encoding gene expressions. The Transformer serves as a decoder to classify sepsis patients and controls. Our model achieves high accuracy with an AUROC of 0.93 on the single-cell test set and an average AUROC of 0.98 on seven bulk RNA cohorts. Additionally, the capsules can recognize different cell types and distinguish sepsis from control samples based on their biological pathways. This study presents a novel approach for learning gene modules and transferring the model to other data types, offering potential benefits in diagnosing rare diseases with limited subjects. Author summaryDeep learning models used in disease diagnosis usually suffer from insufficient data for training and the lack of explainability, especially in rare diseases. These shortages hinder their application to sepsis diagnosis. Here we propose a diagnostic framework name scCaT(https://github.com/Kimxbzheng/CaT), which transfers knowledge learned from single-cell RNA-seq, for diseases with insufficient bulk data. The framework uses capsulating architecture to group genes into capsules and provide explainability to the deep learning model for sepsis diagnosis. ScCaT achieves robust and outstanding performance for sepsis diagnosis in both scRNA-seq and bulk RNA datasets. This architecture offers potential approaches in diagnosing rare diseases with limited subjects with explainability.

bioinformatics↗

Comparative genomics of macaques and integrated insights into genetic variation and population history

The crab-eating macaques (Macaca fascicularis) and rhesus macaques (M. mulatta) are widely studied nonhuman primates in biomedical and evolutionary research. Despite their significance, the current understanding of the complex genomic structure in macaques and the differences between species requires substantial improvement. Here, we present a complete genome assembly of a crab-eating macaque and 20 haplotype-resolved macaque assemblies to investigate the complex regions and major genomic differences between species. Segmental duplication in macaques is [~]42% lower, while centromeres are [~]3.7 times longer than those in humans. The characterization of [~]2 Mbp fixed genetic variants and [~]240 Mbp complex loci highlights potential associations with metabolic differences between the two macaque species (e.g., CYP2C76 and EHBP1L1). Additionally, hundreds of alternative splicing differences show post-transcriptional regulation divergence between these two species (e.g., PNPO). We also characterize 91 large-scale genomic differences between macaques and humans at a single-base-pair resolution and highlight their impact on gene regulation in primate evolution (e.g., FOLH1 and PIEZO2). Finally, population genetics recapitulates macaque speciation and selective sweeps, highlighting potential genetic basis of reproduction and tail phenotype differences (e.g., STAB1, SEMA3F, and HOXD13). In summary, the integrated analysis of genetic variation and population genetics in macaques greatly enhances our comprehension of lineage-specific phenotypes, adaptation, and primate evolution, thereby improving their biomedical applications in human diseases.

genomics↗

Super Pangenome of Grapevines Empowers Improvement of the Oldest Domesticated Fruit

Grapevine (Vitis) is the oldest domesticated fruit crop with great cultural and economic importance. Here, we assemble and annotate haplotype-resolved genomes of 72 Vitis accessions including 25 wild and 47 cultivated grapevines, and a haplotype-resolved complete genome of V. vinifera. Coalescent phylogenomics of 142 haplotype genomes disentangles the mysterious hybridization history of grapevines, revealing enormous genetic diversity among species. Pangenome analysis together with phenotyping data reveals that European cultivars, more susceptible to the most destructive disease downy mildew (DM), had a smaller repertoire of disease resistance genes of NLR family. Through extensive structural variation (SV) characterization, phenotyping, transcriptome profiling of 113 Vitis accessions, and SV-eQTL analysis, we have identified over 79 SVs and their relevant genes significantly associated with DM resistance, exemplified by a lysine histidine transporter, VvLHT8. This haplotype-resolved complete genome and pangenome of Vitis genus will accelerate grapevine breeding and enrich our understanding of the evolution and biology of grapevines.

plant biology↗

Perturbations of glutathione and sphingosine metabolites in Port Wine Birthmark patient-derived induced pluripotent stem cells

Port Wine Birthmark (PWB) is a congenital vascular malformation in the skin, occurring in 1-3 per 1,000 live births. We recently generated PWB-derived induced pluripotent stem cells (iPSCs) as clinically relevant disease models. The metabolites associated with the pathological phenotypes of PWB-derived iPSCs are unknown, which we aimed to explore in this study. Metabolites were separated by ultra-performance liquid chromatography and were screened with electrospray ionization mass spectrometry. Orthogonal partial least-squares discriminant analysis, multivariate and univariate analysis were used to identify differential metabolites (DMs). KEGG analysis was used for the enrichment of metabolic pathways. A total of 339 metabolites were identified. There were 22 DMs confirmed with 9 downregulated DMs including sphingosine and 13 upregulated DMs including glutathione in PWB iPSCs as compared to controls. Pathway enrichment analysis confirmed the upregulation of glutathione and downregulation of sphingolipid metabolism in PWB-derived iPSCs as compared to normal ones. We next examined the expression patterns of the key factors associated with glutathione metabolism in PWB lesions. We found that hypoxia-inducible factor 1 (HIF1), glutathione S-transferase Pi 1 (GSTP1), {gamma}-glutamyl transferase 7 (GGT7), and glutamate cysteine ligase modulatory subunit (GCLM) were upregulated in PWB vasculatures as compared to blood vessels in normal skins. Our data demonstrate that there are perturbations in sphingolipid and cellular redox homeostasis in the PWB vasculature, which may facilitate cell survival and pathological progression. Our data imply that upregulation of glutathione may contribute to laser-resistant phenotypes in the PWB vasculature.

cell biology↗