Biology subjects

He, Y.

Publications and source records attributed to He, Y..

At least 271 records · Page 15Linked to original sources

bioRxiv2024

Alpha-synuclein preformed fibril-induced aggregation and dopaminergic cell death in cathepsin D overexpression and ZKSCAN3 knockout mice

-synuclein accumulation is recognized as a prominent feature in the majority of Parkinsons disease cases and also occurs in a broad range of neurodegenerative disorders including Alzheimers disease. It has been shown that -synuclein can spread from a donor cell to neighboring cells and thus propagate cellular damage, antagonizing the effectiveness of therapies such as transplantation of fetal or iPSC derived dopaminergic cells. As we and others previously have shown, insufficient lysosomal function due to genetic mutations or targeted disruption of cathepsin D can cause -synuclein accumulation. We here investigated whether overexpression of cathepsin D or knockout (KO) of the transcriptional suppressor of lysosomal biogenesis ZKSCAN3 can attenuate propagation of -synuclein aggregation and cell death. We examined dopaminergic neurodegeneration in the substantia nigra using stereology of tyrosine hydroxylase-immunoreactive cells 4 months and 6 months after intrastriatal injection of -synuclein preformed fibrils or monomeric -synuclein control in control, central nervous system (CNS)-cathepsin D overexpressing and CNS-specific ZKSCAN3 KO mice. We also examined pS129--synuclein aggregates in the substantia nigra, cortex, amygdala and striatum. The extent of dopaminergic neurodegeneration and pS129--synuclein aggregation in the brains of CNS-specific ZKSCAN3 knockout mice and CNS-cathepsin D overexpressing mice was similar to that observed in wild-type mice. Our results indicate that neither enhancing cathepsin D expression nor disrupting ZKSCAN3 in the CNS is sufficient to attenuate pS129--synuclein aggregate accumulation or dopaminergic neurodegeneration.

neuroscience↗

bioRxiv2024

Identification of potent biparatopic antibodies targeting FGFR2 fusion driven cholangiocarcinoma.

Translocations involving FGFR2 gene fusions are common in cholangiocarcinoma and predict response to FGFR kinase inhibitors. However, the rate and durability of response are limited due to the emergence of resistance, typically involving acquired FGFR2 kinase domain mutations, and to sub-optimal dosing, relating to drug adverse effects. Here, we report the development of biparatopic antibodies targeting the FGFR2 extracellular domain (ECD), as candidate therapeutics. Biparatopic antibodies can overcome drawbacks of standard bivalent monoparatopic antibodies, which often show poor inhibitory or even agonist activity against oncogenic receptors. We show that oncogenic transformation by FGFR2 fusions requires an intact ECD. Moreover, by systematically generating biparatopic antibodies that target distinct epitope pairs along the FGFR2 ECD, we identified antibodies that effectively block signaling and malignant growth driven by FGFR2-fusions. Importantly, these antibodies demonstrate efficacy in vivo, synergy with FGFR inhibitors, and activity against FGFR2 fusions harboring kinase domain mutations. Thus, biparatopic antibodies may serve as new treatment options for patients with FGFR2-altered cholangiocarcinoma. SummaryWe identify biparatopic FGFR2 antibodies that are effective against FGFR2 fusion driven cholangiocarcinoma.

cancer biology↗

bioRxiv2024

Interpretable high-resolution dimension reduction of spatial transcriptomics data by DeepFuseNMF

Spatial transcriptomics (ST) technologies have revolutionized tissue architecture studies by capturing gene expression with spatial context. However, high-dimensional ST data often have limited spatial resolution and exhibit considerable noise and sparsity, posing significant challenges in deciphering subtle spatial structures and underlying biological activities. Here, we introduce SpaHDmap, an interpretable dimension reduction framework that enhances spatial resolution by integrating ST gene expression with high-resolution histology images. SpaHDmap incorporates non-negative matrix factorization into a multimodal fusion encoder-decoder architecture, enabling the identification of interpretable, high-resolution embeddings. Furthermore, SpaHDmap can simultaneously analyze multiple samples and is compatible with various types of histology images. Extensive evaluations on synthetic and real ST datasets from various technologies and tissue types demonstrate that SpaHDmap can effectively produce highly interpretable, high-resolution embeddings, and detects refined spatial structures. SpaHDmap represents a powerful approach for integrating ST data and histology images, offering deeper insights into complex tissue structures and functions.

bioinformatics↗

bioRxiv2024

G3BP1 Maintains Vascular Endothelial Barrier Integrity by Negatively Regulating the MYD88-ARNO-ARF6 Signaling Pathway

Endothelial permeability is essential for vascular function. This process is regulated by intercellular junctions, including adherens junctions (AJs) and tight junctions (TJs), which form the endothelial barrier and dynamically connect adjacent cells. However, the mechanisms that control endothelial permeability are not fully understood. We investigated the role of the RNA-binding protein G3BP1 in regulating endothelial permeability. We examined the effects of Loss of g3bp1 in conditional knockout mice and primary human HUVEC cells. We analyzed endothelial barrier integrity and permeability, focusing on AJ and TJ expression, under both normal and LPS-induced inflammatory conditions. Loss of g3bp1 in vascular endothelial cells decreased AJ and TJ expression, compromised barrier integrity, and increased permeability. These effects were exacerbated under LPS-induced inflammatory conditions. Loss of g3bp1 also increased the expression of MYD88, ARNO, and ARF6, and enhanced ARF6 activity. Mechanistically, G3BP1 bound to and stabilized MYD88 mRNA, negatively regulating the MYD88-ARNO-ARF6 signaling pathway. Inhibiting this pathway by reducing MYD88 or ARF6 expression, or inhibiting ARNO activity, restored AJ/TJ expression and barrier function in G3BP1-deficient models. Our findings identify G3BP1 as a novel regulator of vascular endothelial permeability. G3BP1 acts by negatively regulating the MYD88-ARNO-ARF6 signaling pathway. Targeting G3BP1 may be a potential therapeutic strategy for diseases associated with endothelial barrier dysfunction.

physiology↗

bioRxiv2024

Development of a DNA-encoded library screening method DEL Zipper to empower the study of RNA-targeted chemical matter

To date, RNA-targeted chemical matter is under explored due to a lack of robust screening assays. In this study, we present a novel RNA-targeted small molecule screening approach using a specialized DNA-encoded library (DEL). Our findings reveal that the specialized DEL library, called "DEL Zipper", can significantly reduce single-stranded DNA-RNA region interaction signals during various kinds of RNA selection. By performing the selection against both G-quadruplex, we have identified novel hits that interact with RNA targets and the results are validated through binding. This study demonstrates that the "DEL Zipper" method is a robust screening assay that has potential for discovering small molecule ligands for diverse RNA targets.

molecular biology↗

bioRxiv2024

Toxoplasma gondii transcription factor AP2XII-8: a key regulator of G1 phase progression and parasite division

The apicomplexan parasite Toxoplasma gondii can infect humans and virtually all warm-blooded animals worldwide, posing a significant threat to public health and being of veterinary importance. Acute infections are characterized by the fast replication of tachyzoites inside host cells. During this fast amplification process, gene expression is highly regulated by a series of regulatory networks. The G1 phase, which is usually conserved across species, is responsible for preparing the materials necessary for the next replicating cell cycle; however, few regulators have been identified at this stage. Here, we functionally characterized the C/G1 phase-expressed ApiAP2 transcription factor, TgAP2XII-8, in T. gondii tachyzoites. Conditional knockdown of TgAP2XII-8 leads to significant growth defects and asexual division disorders. Additionally, parasite cell cycle progression was disrupted following TgAP2XII-8 depletion, characterized by G1 phase arrest. RNA-seq and CUT&Tag experiments revealed that TgAP2XII-8 acts as an activator of ribosomal proteins expressed in the G1 phase. Moreover, TgAP2XII-8 binds to a specific DNA motif ([T/C]GCATGCA), which is abundant and conserved in the intergenic region of several other apicomplexans, possibly suggesting a broad and conserved role for this ApiAP2 in the Phylum of Apicomplexa. Our study reveals that TgAP2XII-8 acts as a critical C/G1 phase regulator, orchestrating the cell cycle in T. gondii tachyzoites. This study contributes to a broader understanding of the complexity of the parasites cell cycle and its key regulators.

microbiology↗

bioRxiv2024

Integration of binocular vision and motor state to promote prey pursuit

Most animals with two eyes combine the inputs to achieve binocular vision, which can serve numerous functions, and is particularly useful in hunting prey. However, the mechanisms by which visual information from the two eyes are combined remain largely unknown. Here, we designed a device to reversibly occlude the eyes of a head-fixed zebrafish larva, and used large-scale volumetric two-photon imaging to identify binocular neurons that respond to prey stimuli. We found these binocular prey-responsive neurons (bino-PRNs) were primarily located in three areas, the pretectum, thalamus, and nucleus isthmi. We then characterized the bino-PRNs functional properties, and found that their left and right eye receptive fields are offset to varying degrees, which would correspond to objects at naturalistic hunting distances for a larva with converged eyes. We also found that bino-PRNs have a significantly greater response in hunting trials, which could be the result of an eye convergence-related corollary discharge. We then optogenetically induced prey capture eye and tail movements, and found that this hunting command activates prey responsive neurons in the pretectum, thalamus, and nucleus isthmi. These findings indicate that bino-PRNs receive visual and motor input that would allow them to encode prey position in three dimensions.

neuroscience↗

bioRxiv2024

Cardiac Fibroblasts regulate myocardium and coronary vasculature development via the collagen signaling pathway

The fibroblast (FB), cardiomyocyte (CM), and vascular endothelial cell (Vas_EC) are the three major cell types in the heart, yet their relationships during development are largely unexplored. To address this gap, we employed RNA staining of the FB marker gene Col1a1 together with the CM marker gene Actn2 and the Vas_EC marker gene Cdh5 at different stages. This approach enabled us to discern the anatomical pattern of cardiac FBs and identify approximately one EC and four CMs directly interacting with each FB. Molecularly, through the analysis of single-cell mRNA sequencing (scRNA-seq) data, we unveiled collagen as the top signaling molecule derived from FBs influencing CM and Vas_EC development. Subsequently, we used a Pdgfra-CreER controlled diphtheria toxin A (DTA) system to ablate the FBs at different stages. We found that the ablation of FBs disrupted myocardium and vasculature development and led to embryonic heart defects. Using scRNA-seq, we further profiled the ablated hearts and identified molecular defects in their ventricular CMs and Vas_ECs compared to control hearts. Moreover, we identified a reduction of collagen in the ablated hearts and predicted collagen as the major signaling pathway regulating the differentially expressed genes in the ablated ventricular CMs. Finally, we performed both short-term and long-term fibroblast ablation at the neonatal stage. We found that short-term ablation caused a reduction in collagen and Vas_EC density, while long-term ablation may induce compensatory collagen expression without causing heart function reduction. In summary, our study has identified the function of fibroblasts in regulating myocardium and vasculature development and implicated an important role for the collagen pathway in this process.

developmental biology↗

bioRxiv2024

Three Subtypes Of Autism Spectrum Disorder With Transcriptomic Signatures Derived From Morphometric Similarity Networks

Autism spectrum disorder (ASD) is a prevalent and highly heterogeneous neurodevelopmental disorder. Previous studies have attempted to identify ASD subgroups by analyzing isolated cortical structural features. However, these studies have not considered the relationship between multiple structural features, which provide information on the structural organization of the brain. Morphometric similarity network (MSN), a structural brain network contributed by multiple anatomical features (gray matter volume, mean cortical thickness, surface area, mean curvature, Gaussian curvature, curvature index, and fold index), strongly relates to cytoarchitectonic and genomic measures of histological similarity between cortical areas. We applied K-means clustering on MSN from 236 individuals with ASD and identified three subtypes. Subtype-1 showed relatively similar MSN values with typically developmental individuals (TD). Subtype-2 showed higher morphometric similarities in the lateral frontal and temporal cortical regions and lower in anterior prefrontal and occipital regions compared to TD. These patterns were the opposite in subtype-3. Behaviorally, subtype-3 had more severe verbal and social deficits compared to subtype-2. The weaker resting-state functional connectivity (rs-FC) between the language and salience networks was observed between subtype-2 and TD. Subtype-3 had stronger rs-FC between salience and default mode networks (DMN), between frontoparietal and visual networks, and between language and dorsal attention networks, while weaker rs-FC within DMN, within sensorimotor, and within salience networks. In addition, genes with expression patterns associated with regional MS changes in ASD subtypes were functionally enriched in neuron-specific biological processes related to nervous system development, synaptic signaling and chromatin organization. These genes were particularly enriched in GABAergic neurons, glutamatergic neurons, astrocytes and microglia. Taken together, our findings suggest the existence of different neuroanatomical subtypes based on multiple anatomical features in ASD with distinct transcriptomic signatures and functional connectome patterns.

neuroscience↗

bioRxiv2024

Enhancing Vaxign-DL for Vaccine Candidate Prediction with added ESM-Generated Features

Many vaccine design programs have been developed, including our own machine learning approaches Vaxign-ML and Vaxign-DL. Using deep learning techniques, Vaxign-DL predicts bacterial protective antigens by calculating 509 biological and biomedical features from protein sequences. In this study, we first used the protein folding ESM program to calculate a set of 1,280 features from individual protein sequences, and then utilized the new set of features separately or in combination with the traditional set of 509 features to predict protective antigens. Our result showed that the usage of ESM-derived features alone was able to accurately predict vaccine antigens with a performance similar to the orginal Vaxign-DL prediction method, and the usage of the combined ESM-derived and orginal Vaxign-DL features significantly improved the prediction performance according to a set of seven scores including specificity, sensitivity, and AUROC. To further evaluate the updated methods, we conducted a Leave-One-Pathogen-Out Validation (LOPOV) study, and found that the usage of ESM-derived features significantly improved the the prediction of vaccine antigens from 10 bacterial pathogens. This research is the first reported study demonstrating the added value of protein folding features for vaccine antigen prediction.

bioinformatics↗

bioRxiv2024

Deep Generative Optimization of mRNA Codon Sequences for Enhanced Protein Production and Therapeutic Efficacy

Messenger RNA (mRNA) therapeutics show immense promise, but their efficacy is limited by suboptimal protein expression. Here, we present RiboDecode, a deep learning framework that generates mRNA codon sequences for enhanced mRNA translation. RiboDecode introduces several advances, including direct learning from large-scale ribosome profiling data and generative exploration of a large sequence space. In silico analysis demonstrates RiboDecode s robust predictive accuracy for unseen genes and cellular environments. In vitro experiments showed substantial improvements in protein expression, significantly outperforming past methods. In addition, RiboDecode enables mRNA design with consideration of cellular context and demonstrates robust performance across different mRNA formats, including m1{Psi}-modified and circular mRNAs, an important feature for mRNA therapeutics. In vivo mouse studies showed that optimized influenza hemagglutinin mRNAs induce ten times stronger neutralizing antibody responses against influenza virus compared to the unoptimized sequence. In an optic nerve crush model, optimized nerve growth factor mRNAs achieve equivalent neuroprotection of retinal ganglion cells at one-fifth the dose of the unoptimized sequence. Collectively, RiboDecode represents a paradigm shift from rule-based to a data-driven, context-aware approach for mRNA therapeutic applications, enabling the development of more potent and dose-efficient treatments.

bioinformatics↗

bioRxiv2024

Genotype inference from aggregated chromatin accessibility data reveals genetic regulatory mechanisms

BackgroundUnderstanding the genetic causes for variability in chromatin accessibility can shed light on the molecular mechanisms through which genetic variants may affect complex traits. Thousands of ATAC-seq samples have been collected that hold information about chromatin accessibility across diverse cell types and contexts, but most of these are not paired with genetic information and come from diverse distinct projects and laboratories. ResultsWe report here joint genotyping, chromatin accessibility peak calling, and discovery of quantitative trait loci which influence chromatin accessibility (caQTLs), demonstrating the capability of performing caQTL analysis on a large scale in a diverse sample set without pre-existing genotype information. Using 10,293 profiling samples representing 1,454 unique donor individuals across 653 studies from public databases, we catalog 23,381 caQTLs in total. After joint discovery analysis, we cluster samples based on accessible chromatin profiles to identify context-specific caQTLs. We find that caQTLs are strongly enriched for annotations of gene regulatory elements across diverse cell types and tissues and are often strongly linked with genetic variation associated with changes in expression (eQTLs), indicating that caQTLs can mediate genetic effects on gene expression. We demonstrate sharing of causal variants for chromatin accessibility and diverse complex human traits, enabling a more complete picture of the genetic mechanisms underlying complex human phenotypes. ConclusionsOur work provides a proof of principle for caQTL calling from previously ungenotyped samples, and represents one of the largest, most diverse caQTL resources currently available, informing mechanisms of genetic regulation of gene expression and contribution to disease.

genomics↗

bioRxiv2024

Leveraging Multi-Modal Feature Learning for Predictions of Antibody Viscosity

The shift towards the subcutaneous administration route for biologics therapeutics has gained momentum due to its patient-friendly nature, convenience, reduced healthcare burden, and improved compliance compared to traditional intravenous infusions. However, one of the potentially significant challenges with this transition is managing the viscosity of the administered solutions. High viscosity can pose substantial development and manufacturability challenges, directly impacting the patient by increasing injection time and pain at the injection site. Moreover, high viscosity formulations can prolong residence time at the injection site, affecting absorption kinetics and potentially altering the intended pharmacological profile and therapeutic efficacy of the biologic candidate. This publication explores the application of a multimodal feature learning workflow for predicting the viscosity of antibodies in therapeutics discovery, integrating multiple data sources such as sequence, structural, physicochemical properties, and embeddings from a language model. This approach enables the model to learn from various underlying rules, including physicochemical rules from molecular simulations and molecular protein evolutionary rules by large, pre-trained deep learning foundation models. By comparing the effectiveness of this approach against other selected published viscosity prediction methods, this study offers insights on their intrinsic viscosity predictive potential and usability in therapeutics antibody early development pipelines.

bioinformatics↗

bioRxiv2024

Chemical crosslinking extends and complements UV crosslinking in analysis of RNA/DNA nucleic acid-protein interaction sites by mass spectrometry

UV (ultra-violet) crosslinking with mass spectrometry (XL-MS) has been established for identifying RNA- and DNA-binding proteins along with their domains and amino acids involved. Here, we explore chemical XL-MS for RNA-protein, DNA-protein, and nucleotide-protein complexes in vitro and in vivo. We introduce a specialized nucleotide-protein-crosslink search engine, NuXL, for robust and fast identification of such crosslinks at amino acid resolution. Chemical XL-MS complements UV XL-MS by generating different crosslink species, increasing crosslinked protein yields in vivo almost four-fold, and thus it expands the structural information accessible via XL-MS. Our workflow facilitates integrative structural modelling of nucleic acid-protein complexes and adds spatial information to the described RNA-binding properties of enzymes, for which crosslinking sites are often observed close to their cofactor-binding domains. In vivo UV and chemical XL-MS data from E. coli cells analysed by NuXL establish a comprehensive nucleic acid-protein crosslink inventory with crosslink sites at amino acid level for more than 1500 proteins. Our new workflow combined with the dedicated NuXL search engine identified RNA crosslinks that cover most RNA-binding proteins, with DNA and RNA crosslinks detected in transcriptional repressors and activators.

biochemistry↗

bioRxiv2024

Tracing the genetic diversity of the bread wheat D genome

Bread wheat (Triticum aestivum) became a globally dominant crop after incorporating the D genome from donor species Aegilops tauschii, while evolutionary history shaping the D genome during this process remains elusive. Here, we proposed a renewed evolutionary model linking Ae. tauschii and hexaploid wheat D genome, based on an ancestral haplotype map covering a total of 762 Ae. tauschii and hexaploid wheat accessions. We dissected the evolutionary process of Ae. tauschii lineages and clarified L3 as the most ancient lineage. A few independent intermediate accessions were reported, demonstrating the low-frequent inter-sublineage geneflow enriched the diversity of Ae. tauschii. We discovered that the D genome of hexaploid wheat inherited from a unified ancestral template, but with a mosaic composition that is highly mixed by three Ae. tauschii L2 sublineages located in the Caspian coastal region, suggesting the early agricultural activities facilitate the innovation of D genome compositions that finalized the success of hexaploidization. We further found that the majority (65.6%) of polymorphisms were attributed to novel mutations absent during the spreading of bread wheat, and also identified large Ae. tauschii introgressions from wild Aegilops lineages, expanding the diversity of wheat D genome and introducing beneficial alleles. This work decoded the mystery of the wheat hexaploidization process and the evolutionary significance of the multi-layered origins of the genetic diversity of the bread wheat D genome.

evolutionary biology↗

bioRxiv2024

Enhancing Variant Calling in Whole Exome Sequencing (WES) Data Using Population-Matched Reference Genomes

Whole exon sequencing (WES) data are frequently used for cancer diagnosis and genome-wide association studies (GWAS), hinging upon high-coverage read mapping, informative variant calling, and high-quality reference genomes. The center position of the currently used genome assembly, GRCh38, is now challenged by two newly publicized telomere-to-telomere or T2T genomes, T2T-CHM13 and T2T-YAO, and it becomes urgent to have a comparative study to test population specificity using the three reference genomes based on real case WES data. We here report our analysis along this line for 19 tumor samples collected from Chinese patients. The primary comparison of the exon regions among the three references reveals that the sequences in up to [~]1% target regions in YAO are widely diversified from GRCh38 and may lead to off-target in sequence capture. However, YAO still outperforms GRCh38 genomes by obtaining 7.41% more mapped reads. Due to more reliable read-mapping and closer phylogenetic relationship with the samples than GRCh38, YAO reduces half of variant calls of clinical significance which are mostly benign while keeping sensitivity in identifying pathogenic variants. YAO also outperforms CHM13 in reducing calls of Chinese-specific variants. Our findings highlight the critical need for employing population-specific reference genomes in genomic analysis to ensure accurate variant analysis and the significant benefits of tailoring these approaches to the unique genetic backgrounds of each ethnic group.

genomics↗

bioRxiv2024

Protein Carrier AAV

AAV is widely used for efficient delivery of DNA payloads. The extent to which the AAV capsid can be used to deliver a protein payload is unexplored. Here, we report engineered AAV capsids that directly package proteins - Protein Carrier AAV (pcAAV). Nanobodies inserted into the interior of the capsid mediate packaging of a cognate protein, including Green Fluorescent Protein (GFP), Streptococcus pyogenes Cas9, Cre recombinase, and the engineered peroxidase APEX2. We show that protein packaging efficiency is affected by the nanobody insertion position, the capsid protein isoform into which the nanobody is inserted, and the subcellular localization of the packaged protein during recombinant AAV capsid production; each of these factors can be rationally engineered to optimize protein packaging efficiency. We demonstrate that proteins packaged within pcAAV retain their enzymatic activity and that pcAAV can bind and enter the cell to deliver the protein payload. Establishing pcAAV as a protein delivery platform may expand the utility of AAV as a therapeutic and research tool.

synthetic biology↗

bioRxiv2024

A Refined Analysis of Neanderthal-Introgressed Sequences in Modern Humans with a Complete Reference Genome

BackgroundLeveraging long-read sequencing technologies, the first complete human reference genome, T2T-CHM13, corrects the assembly errors in prior references and addresses the remaining 8% of the genome. While the studies on archaic admixture in modern humans so far have been relying on the GRCh37 reference due to the archaic genome data, the impact of T2T-CHM13 in this field remains unknown. ResultsWe remapped the sequencing reads of the high-quality Altai Neanderthal and Denisovan genomes onto GRCh38 and T2T-CHM13 respectively. Compared with GRCh37, we found T2T-CHM13 has a significant improvement of read mapping quality in archaic samples. We then applied IBDmix to identify Neanderthal introgressed sequences in 2,504 individuals from 26 geographically diverse populations in different references. We observed different pre-phasing filtering strategies prevalently used in public data can largely impact determination of archaic ancestry, calling for consideration on the choice of filters. We discovered ~51Mb T2T-CHM13 unique Neanderthal sequences, which are predominantly located in regions where the variants distinct between the GRCh38 and T2T-CHM13 assemblies emerge. Besides, we unfolded new instances of population-specific archaic introgression in diverse populations, covering genes involved in metabolism, olfactory-related, and icon-channel. Finally, we integrated the introgressed sequences and adaptive signals with all references into a visualization database website, called ASH (www.arcseqhub.com), to facilitate the utilization of archaic alleles and adaptive signals in human genomics and evolutionary research. ConclusionsOur study refines the detection of archaic variations in modern humans, highlights the importance of T2T-CHM13 reference utility, and provides novel insights into functional consequences of archaic hominin admixture.

evolutionary biology↗