Biology subjects

Xue, L.

Publications and source records attributed to Xue, L..

At least 37 records · Page 2Linked to original sources

bioRxiv2025

Deciphering the microbial landscape of lower respiratory tract in health and respiratory diseases

The microbiota plays an important role in maintaining lung homeostasis and the development of respiratory diseases. However, there have not been detailed characteristics of lung microbiome in health and respiratory diseases. Bronchoalveolar lavage fluid of 43 healthy individuals, 23 COVID patients, and 28 non-small cell lung cancer patients was conducted to characterize microbial diversity and function by metagenomic sequencing. We identified 196 species in health lung after removing low abnudance species. The most abundant species were Staphylococcus aureus, Salmonella enterica, and Klebsiella pneumoniae. Keystone species were identified through co-network analysis, such as Granulicatella adiacens and Mogibacterium diversum. To further explore the microbial function in the healthy lung, we obtained 56 non-redundant metagenome-assembled genomes (MAGs) and subsequently classified them into nine phyla. Metabolism and genetic information processing exhibit high abundance, including bacterial secretion systems, protein export, and Staphylococcus aureus infection, indicating a close correlation between microbiota and the host. Furthermore, the microbiome pairwise distances of non-small cell lung cancer (NSCLC) participants were more similar to those of the healthy group than those of individuals with COVID-19. Rothia dentocariosa, Corynebacterium kefirresidentii, Sphingobium yanoikuyae were enriched in the healthy group, while Schaalia odontolytica, Actinomyces graevenitzii, and Rothia mucilaginosa was enriched in the NSCLC group. Overall, this study provides a comprehensive overview of the diversity and gene function of the lung microbiome, which will facilitate future studies of microbiota associated with respiratory diseases in humans.

microbiology↗

bioRxiv2025

High-throughput in vivo screening using barcoded mRNA identifies lipid nanoparticles with extrahepatic tropism for cancer immunotherapy

Interest continues to grow in the use of mRNA vaccines for cancer immunotherapy. While effective for immunization against infectious diseases, current clinical lipid nanoparticle (LNP) formulations used for mRNA delivery suffer from off-target accumulation, poor immune transfection, and reactogenicity, limiting their application to cancer immunotherapy. Development of new mRNA LNPs is severely bottlenecked by the LNP discovery process, which is historically low-throughput due to reliance on low-plexity measurements. Here, we develop a next-generation high-throughput in vivo mRNA LNP screening platform based on barcoded mRNA (b-mRNA). Using this b-mRNA screening platform to simultaneously evaluate 122 LNPs, we identify novel LNP formulations capable of potent hepatic and extrahepatic transfection. We employ novel biochemical characterization techniques to analyze nanoparticle protein corona formation with single-particle resolution and gain insight into the influence of protein adsorption on hepatic and splenic transfection. We evaluate a lead LNP candidate for therapeutic cancer vaccination in a syngeneic mouse model of melanoma and demonstrate a significant reduction in tumor burden and increase in survival compared to a clinical mRNA LNP formulation. Together, our results demonstrate the value of advanced LNP screening and characterization techniques for the development of next-generation mRNA therapeutics and vaccines.

bioengineering↗

bioRxiv2025

In-cell discovery and characterization of a non-canonical bacterial protein translocation-folding complex

Cryo-electron tomography has emerged as powerful technology for in-cell structural biology, and in combination with breakthroughs in protein structure prediction, offers a unique opportunity for illuminating functions of previously uncharacterized macromolecular complexes. Here, we used the genome-reduced bacterium Mycoplasma pneumoniae as a minimal cell model, and determined in-cell maps of an unknown complex located at the cell surface. By combining proteomics, structure prediction, and bioinformatics, we identified the complex to include the conserved Sec-translocon and an extracellular dome-like structure largely formed by three uncharacterized proteins (Mdps). The Mdps show structural homology to a periplasmic ATP-independent foldase, PrsA, with Mdp444 retaining key catalytic residues. Our study provides the first sub-nanometer resolution maps of the complete bacterial Sec-translocation machinery, depicting several conformational states that allow us to suggest a model for translocation initiation, and revealing its coordination with a novel, extracellular, protein-folding system.

molecular biology↗

bioRxiv2025

ZMS-6659, a selective Polθ helicase inhibitor, demonstrates anti-tumor activity as monotherapy and synergy effect with PARP inhibitors and topoisomerase inhibitors

The repair of DNA double strand break (DSB) is crucial for genome stability. Homologous recombination (HR) is a high-fidelity, error-free DSB repair pathway, and its dysfunction leads to genome instability and can result in tumorigenesis. In HR deficient contexts, microhomology-mediated end joining (MMEJ), dependent on DNA polymerase theta (Pol{theta}), is up-regulated to serve as a backup pathway for DSB repair. Several studies have proved that Pol{theta} inhibition causes synthetic lethality with HR deficiency, and Pol{theta} emerges as a potential DNA damage repair (DDR) target for the treatment of HR deficient tumors both as single agent or in combination with PARP inhibitors (PARPi). In addition, evidences show that the blockage of Pol{theta} can enhance the sensitivity to DNA damage agents. Herein, we characterized ZMS-6659, a highly potent small-molecule Pol{theta} inhibitor targeting the helicase domain. ZMS-6659 induces synthetic lethality in HR deficient models, elicits synergistic effects with even low dose of PARPi and delays PARPi resistance without additional hematotoxicity. Besides, ZMS-6659 also enhance the sensitivity to topoisomerase inhibitors in HR proficient cell lines. These findings support the clinical exploration of ZMS-6659 in combination with PARPi in HR deficient tumors, and suggest a potential application expansion beyond HR deficiency.

cancer biology↗

bioRxiv2025

ER fusogens maintain membrane reservoir to ensure brain function

How the morphological dynamics of the endoplasmic reticulum (ER) are linked to its functions is unclear. Atlastins (ATLs), a class of GTPases, mediate ER fusion, and human mutations in ATL1 cause hereditary spastic paraplegia (HSP). Here, we show that ATL2-knockout mice are embryonic lethal with compromised development, particularly of the cerebellum. ATL2 is highly expressed in neuroglia, though ATL1 is dominant in the brain. Lack of ATL2 disorganizes the positioning of Bergmann glia, which in turn interferes with granule cell migration. These cells have significant shrinkage in the intracellular membrane area, which is associated with decreased phosphatidylcholine and cholesterol synthesis. When tested in calyx-type synapses in ATL-deleted mice, a reduced membrane reservoir, represented by fewer presynaptic vesicles, leads to defective synaptic function and deafness. Collectively, these findings suggest that ER-shaping activity by ATL is essential for sustained lipid synthesis, and boosted lipid uptake is potentially beneficial for HSP patients.

neuroscience↗

bioRxiv2025

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↗

bioRxiv2025

spVelo: RNA velocity inference for multi-batch spatial transcriptomics data

RNA velocity has emerged as a powerful tool to interpret transcriptional dynamics and infer trajectory from snapshot datasets. However, current methods fail to utilize the spatial information inherent in spatial transcriptomics and lack scalability in multi-batch datasets. Here, we introduce spVelo (spatial Velocity inference), a scalable framework for RNA velocity inference in multi-batch spatial transcriptomics data. Our model comparison studies show that spVelo compares favorably to existing methods regarding velocity consistency, transition accuracy, and direction correctness across expression levels, spatial graphs in each batch, and MNN graphs between batches. Furthermore, spVelo supports several downstream applications, including uncertainty quantification, complex trajectory pattern discovery, biologically significant state driver marker identification, gene regulatory network inference and temporal cell-cell communication inference. In conclusion, spVelo has the potential to provide deeper insights into complex tissue organization and underscore their biological mechanisms based on spatially-resolved patterns.

bioinformatics↗

bioRxiv2025

Plug-and-play assembly of biodegradable ionizable lipids for potent mRNA delivery and gene editing in vivo

mRNA-based gene editing therapeutics offer the potential to permanently cure diseases but are hindered by suboptimal delivery platforms. Here, we devise a robust combinatorial chemistry for plug-and-play assembly of diverse biodegradable ionizable lipids and identify a lead candidate that produces superior lipid nanoparticles for various gene editing tools delivery in vivo. Our study highlights the utility of this synthetic approach and the generality of this platform for potent in vivo gene editing.

bioengineering↗

bioRxiv2025

TRIM21-NUP98 interface accommodates structurally diverse molecular glue degraders

Molecular glue degraders enable targeted protein degradation by bridging interactions between target proteins and E3 ubiquitin ligases. Whereas some protein-protein interfaces exhibit the capacity to accommodate structurally diverse degraders, the extent of this adaptability across molecular glue targets remains unclear. We recently identified (S)-ACE-OH as a molecular glue degrader that recruits the E3 ubiquitin ligase TRIM21 to the nuclear pore complex by recognizing NUP98, thereby inducing the degradation of nuclear pore proteins. Here, we analyzed public compound toxicity data across a large collection of cell lines and identified two additional molecular glue degraders, PRLX 93936 and BMS-214662, that engage the TRIM21-NUP98 interface to induce the degradation of nucleopore proteins. Additionally, we confirmed that HGC652, another TRIM21-dependent molecular glue degrader, also binds at this interface. Together with our previously characterized degrader (S)-ACE-OH, these findings demonstrate that the TRIM21-NUP98 interface can accommodate structurally diverse molecular glue degraders, expanding the potential for its therapeutic exploitation.

biochemistry↗

bioRxiv2024

Deciphering Ca2+ Permeation and Valence Selectivity in Cav1: Molecular Dynamics Simulations Reveal the Three-Ion Knock-on Mechanism

Voltage-gated calcium (CaV) channels are pivotal in cellular signaling due to their selective calcium ion permeation upon membrane depolarization. While previous studies have established the highly selective permeability of CaV channels, the detailed molecular mechanism remains elusive. Here we use extensive atomistic molecular dynamics simulations to elucidate the mechanisms governing ion permeation and valence selectivity in CaV1 channels. Employing the electronic continuum correction method, we simulated a calcium conductance of approximately 9-11 pS, aligning closely with experimental measurement. Our simulations uncovered a three-ion knock-on mechanism critical for efficient calcium ion permeation, necessitating the binding of at least two calcium ions within the selectivity filter (SF) and the subsequent entry of a third ion. In silico mutation simulations further validated the importance of multi-ion coordination in the SF for efficient ion permeation, identifying two critical residues, D706 and E1101, that are essential for the binding of two calcium ions in the SF. Moreover, we explored the competitive permeation of calcium and sodium ions, and obtained a valence selectivity favoring calcium over sodium at a ratio of approximately 35:1 under the bi-cation condition. This selectivity arises from the strong electrostatic interactions of calcium ions in the confined SF and the three-ion knock-on mechanism. Our findings provide novel insights into the molecular underpinnings of CaV channel function, with implications for understanding calcium-dependent cellular processes.

biophysics↗

bioRxiv2024

Bidirectional Peptide Conformation Prediction for MHC Class II using PANDORA

Recent discoveries have transformed our understanding of peptide binding in Major Histocompatibility Complex (MHC) molecules, showing that peptides, for some MHC class II alleles, can bind in a reverse orientation (C-terminus to N-terminus) and can still effectively activate CD4+ T cells. These finding challenges established concepts of immune recognition and suggests new pathways for therapeutic intervention, such as vaccine design. We present an updated version of PANDORA, which, to the best of our knowledge, is the first tool capable of modeling reversed-bound peptides. Modeling these peptides presents a unique challenge due to the limited structural data available for these orientations in existing databases. PANDORA has overcome this challenge through integrative modeling using algorithmically reversed peptides as templates. We have validated the new PANDORA feature through a series of experiments, achieving an average backbone binding-core L-RMSD value of 0.63 [A]. Notably, it maintained low RMSD values even when using templates from different alleles and peptide sequences. Our results suggest that PANDORA will be an invaluable resource for the immunology community, aiding in the development of targeted immunotherapies and vaccine design. AvailabilitySource code and data is freely available at https://github.com/X-lab-3D/PANDORA; Contact: Li.Xue@radboudumc.nl

immunology↗

bioRxiv2024

Protocol for Simulating the Effect of THz Electromagnetic Field on Ion Channels

Terahertz (THz) electromagnetic fields are increasingly recognized for their crucial roles in various aspects of medical research and treatment. Recent computational studies have demon-strated that THz waves can modulate ion channel function by interacting with either the channel proteins or the bound ions through distinct mechanisms. Here we outline a universal simulation protocol to identify the THz frequencies that may affect ion channels, which consists of frequency spectrum analysis and ion conductance analysis. Following this protocol, we studied the effect of THz field on a CaV channel and found a broad frequency band in 1 to 20 THz range. We believe that this protocol, along with the identified characteristic frequencies, will provide a theoretical foundation for future terahertz experimental studies.

biophysics↗

bioRxiv2024

The Effect of THz Electromagnetic Field on the Conductance of Potassium and Sodium Channels

Ion channels are essential to various physiological processes and their defects are associated with many diseases. Previous research has revealed that Terahertz electromagnetic field can alter the channel conductance by affecting the motion of chemical groups of ion channels, and hence regulate the electric signals of neurons. In this study, we conducted molecular dynamics simulations to systematically investigate the effects of terahertz electromagnetic fields on the conductance of voltage-gated potassium and sodium channels, particularly focusing on the bound ions in the selectivity filters that have not been studied previously. Our results identified multiple new characteristic frequencies and showed that 1.4, 2.2, or 2.9 THz field increases the conductance of Kv1.2, and 2.5 or 48.6 THz field increases the conductance of Nav1.5. The conductance-enhancing effects are specific to the frequencies and directions of the electric field, which are determined by the intrinsic oscillation motions of the permeating ions in the selectivity filter or certain chemical groups of the ion channels. The amplitude of the THz field positively correlates with the change in ion conductance. Therefore, this study demonstrates that THz fields can specifically regulate ion channel conductances, which may carry great potential in biomedical applications.

biophysics↗

bioRxiv2024

Multi-parametric thrombus profiling microfluidics detects intensified biomechanical thrombogenesis associated with hypertension and aging

Arterial thrombosis, which represents a critical complication of cardiovascular diseases, is a leading cause of death and disability worldwide with no effective bioassay for clinical prediction. As a symbolic feature of arterial thrombosis, severe stenosis in the blood vessel creates a high-shear, high-gradient flow environment that effectively facilitates platelet aggregation towards vessel occlusion even with platelet amplification loops inhibited. However, no approach is currently available to comprehensively characterize the size, composition and platelet activation status of thrombi forming under this biorheological condition. Here, we present a thrombus profiling assay that monitors the multi-dimensional attributes of thrombi forming in conditions mimicking the physiological scenario of arterial thrombosis. Using this platform, we demonstrate that different receptor-ligand interactions contribute distinctively to the composition and activation status of the thrombus. Our investigation into hypertensive and older individuals reveals intensified biomechanical thrombogenesis and multi-dimensional thrombus profile abnormalities, demonstrating a direct contribution of mechanobiology to arterial thrombosis and endorsing the diagnostic potential of the assay. Furthermore, we identify the hyperactivity of GPIb-integrin IIb{beta}3 mechanosensing axis as a molecular mechanism that contributes to hypertension-associated arterial thrombosis. By studying the interactions between anti-thrombotic inhibitors and hypertension, and the inter-individual variability in personal thrombus profiles, our work reveals a critical need for personalized anti-thrombotic drug selection that accommodates each patients pathological profile.

bioengineering↗

bioRxiv2024

Selective degradation of multimeric proteins via chemically induced proximity to TRIM21

Targeted protein degradation (TPD) has emerged as an effective strategy to eliminate disease-causing proteins by inducing their interactions with the protein degradation machinery. First-generation TPD agents exploit a limited set of broadly expressed E3 ubiquitin ligases with constitutive activity, forbidding their application to proteins requiring higher levels of targeting selectivity. Here, by phenotype-based screening, we discovered that the antipsychotic drug acepromazine possesses interferon-enhanced cytotoxicity towards cancer cell lines expressing high levels of aldo-keto reductases 1C. These enzymes convert acepromazine into its stereo-selective metabolite (S)-hydroxyl-acepromazine, which recruits the interferon-induced E3 ubiquitin ligase TRIM21 to the vicinity of the nuclear pore complex, resulting in the degradation of nuclear pore proteins. Co-crystal structures of acepromazine and derivatives in complex with the PRYSPRY domain of TRIM21 revealed a ligandable pocket, which was exploited for designing heterobifunctional degraders. The resulting chemicals selectively degrade multimeric proteins-- such as those in biomolecular condensates--without affecting monomeric proteins, consistent with the requirement of substrate-induced clustering for TRIM21 activation. As aberrant protein assemblies have been causally linked to diseases such as neurodegeneration, autoimmunity, and cancer, our findings highlight the potential of TRIM21-based multimer-selective degraders as a strategy to tackle the direct causes of these diseases.

pharmacology and toxicology↗

bioRxiv2024

CoSpred: Machine learning workflow to predict tandem mass spectrum in proteomics

In mass spectrometry-based proteomics, the identification and quantification of peptides and proteins is usually done using database search algorithms or spectral library matching. The use of deep learning algorithms can help improve the identification rates of peptides and proteins through the generation of high-fidelity theoretical spectrum which can be used as the basis of a more complete spectral library than those presently available. Current methods focus on predicting only backbone ions, such as y- and b-ions. However, the inclusion of non-backbone ions is necessary to truly improve spectral library matching. Here we focus on providing a user-friendly machine learning workflow, which we call Complete Spectrum Predictor (CoSpred). Using CoSpred users can create their own machine learning compatible training dataset and then train a Machine Learning model to predict both backbone and non-backbone ions. For the model a transformer encoder architecture is used to predict the complete MS/MS spectrum from a given peptide sequence. This model does not require background knowledge of fragment ion annotations or fragmentation rules. The model outputs the set of pairs (Mi, Ii) where Mi is the m/z (mass-to-charge ratio) of a peak in the spectrum and Ii is the intensity of the peak. The model presented here for validation was trained on the dataset available in the MassIVE data repository and shows superior performance in terms of various metrics (e.g. precision/recall for mass, cosine similarity for peak intensity, etc) between the true and predicted spectra. Furthermore, CoSpred can be used to create custom models that allow for accurate spectrum prediction for different experimental conditions. In addition to the transformer model provided in the package, the code is built modularly to allow for alternate ML models to be easily "plugged in". The CoSpred workflow (preprocessing->training->inference) provides a path for state-of-art ML capabilities to be more accessible to proteomics scientists.

bioinformatics↗

bioRxiv2024

Multi-faceted roles of β-arrestins in G protein-coupled receptors endocytosis

Internalization plays a crucial role in regulating the density of cell surface receptors and has been demonstrated to regulate intracellular signaling. Dysregulation of this process has been implicated in various diseases. The vast majority of GPCRs were considered to adopt one way for internalization. We challenged this conventional view by showing that multiple pathways converge to regulate the internalization of a specific receptor, based on an unparalleled characterization of 60 GPCR internalization profiles, both in the absence and presence of individual {beta}-arrestins ({beta}arrs). Furthermore, we revealed the internalization mechanism of the glucagon-like peptide-1 receptor (GLP-1R), a class B GPCR pivotal in promoting insulin secretion from pancreatic beta cells to maintain glucose homeostasis. GLP-1R can undergo agonist-induced internalization without {beta}arrs, but can recruit and form stable complexes with {beta}arrs. We found that GLP-1R recruits clathrin adaptor protein-2 for agonist-induced internalization in both {beta}arr-dependent and -independent manners. These results provide a valuable resource for GPCR signaling and reveal the plasticity of different GPCRs to employ or not {beta}arrs in the clathrin-mediated internalization.

cell biology↗

bioRxiv2023

Single cell discovery of m6A RNA modifications in the hippocampus

N6-methyladenosine (m6A) is a prevalent and highly regulated RNA modification essential for RNA metabolism and normal brain function. It is particularly important in the hippocampus, where m6A is implicated in neurogenesis and learning. Although extensively studied, its presence in specific cell types remain poorly understood. We investigated m6A in the hippocampus at the single cell level, revealing a comprehensive landscape of m6A modifications within individual cells. Our data also identifies transcripts which have high m6A density and are associated with brain diseases. Our data suggests that m6A containing transcripts might be of particular importance for Camk2a neurons. Overall, this work provides new insights into the molecular mechanisms underlying hippocampal physiology and lays the foundation for future studies investigating the dynamic nature of m6A RNA methylation in the healthy and diseased brain.

neuroscience↗