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Sun, Z.

Publications and source records attributed to Sun, Z..

At least 127 records · Page 7Linked to original sources

Shroom3-Rock interaction and profibrotic function: Resolving mechanism of an intronic CKD risk allele.

Common intronic enhancer SNPs in Shroom3 associate with CKD in GWAS, although there is paucity of detailed mechanism. Previously, we reported a role for Shroom3 in mediating crosstalk between TGF{beta}1- & Wnt/Ctnnb1 pathways promoting renal fibrosis (TIF). However, beneficial roles for Shroom3 in proteinuria have also been reported suggesting pleiotropic effects. Here we focused on identifying the specific profibrotic Shroom3 motif. Given known therapeutic roles for Rho-kinase inhibitors in experimental CKD, and the established interaction between Shroom3 and Rock via its ASD2 domain, we hypothesized that Shroom3-mediated ROCK activation played a crucial role in its profibrotic function in high expressors. To test this hypothesis, we developed transgenic mice and cell lines that inducibly overexpressed wild-type- (WT-Sh3) or ASD2-domain deletion- Shroom3 (ASD2{Delta}-Sh3). Prior scRNAseq data showed that during TIF, Shroom3 and Rock co-expression occurred in injured tubular cells and fibroblasts, highlighting cell-types where this mechanism could be involved. Using HEK293T cells, we first confirmed absent ROCK binding and inhibited TGF{beta}1-signaling with ASD2{Delta}-Sh3-overexpression vs WT-Sh3. In mIMCD cells, ASD2{Delta}-Sh3 overexpression, reduced Rock activation (phospho-MYPT1), pro-fibrotic and pro-inflammatory transcripts vs WT-Sh3. Fibroblast proliferation (3T3) was also reduced with ASD2{Delta}-Sh3. In vivo, we studied ureteric obstruction (UUO) and Aristolochic nephropathy (AAN) as TIF models. In AAN, inducible global-, or Pan-tubular specific-, WTSh3-overexpression showed increased azotemia, and TIF vs ASD2{Delta}-Sh3 mice. WT-Sh3 mice consistently showed significant enrichment of Rho-GTPase, TGF{beta}1- and Wnt/CtnnB1- signaling in kidney transcriptome, paralleling Shroom3-coexpressed genes in tubulo-interstitial transcriptomes from human CKD. In UUO, again WT-Sh3 mice recapitulated increased fibrosis vs ASD2{Delta}-Sh3. Importantly, ASD2{Delta}-Sh3 did not develop albuminuria vs WT-Sh3, while mutating a disparate Fyn-binding Shroom3 motif induced albuminuria in mice, suggesting motif-specific roles for Shroom3 in the kidney. Hence, our data show a critical role for the Rock-binding, ASD2-domain in mediating TIF in milieu of Shroom3 excess, with relevance to human CKD.

systems biology↗

Insights on macrosynteny, 'rebel' genes, and a new sex-linked region in anurans from comparative genomics and a new chromosome-level genome for the western chorus frog

Amphibians have unique genome characteristics including slow karyotypic evolution and cytogenetically undifferentiated sex chromosomes. Yet our understanding of amphibian genomes has not kept pace with that of mammals and birds, partially due to scarce genomic resources and challenges associated with large genome sizes and high repetitiveness. We assembled and annotated a chromosome-level genome for the western chorus frog (Pseudacris triseriata), a species of conservation concern and importance in evolutionary research. Comparison of our new genome with other chromosome-level frog genomes reveals exceptionally conserved evolution of 13 chromosomal elements and gene orders across over 200 million years of anuran evolution. We uncovered rebel Benchmarking Universal Single-Copy Orthologs (BUSCO) genes that have been duplicated in almost all frog species, have been transposed, and showed lineage-specific synteny patterns - possibly relating to key traits such as frog advertisement calls and mitochondrial genome evolution. We also assembled a complete mitochondrial genome and found heteroplasmy of both point polymorphisms and length variation in the tandem repeat arrays in the control region. Double-digest restriction-site associated DNA sequencing analysis indicates that the western chorus frog has an XY sex system and the sex-linked region involved an [~]1Mb indel structural variant. Overall, our study provides important genomic resources for treefrogs and other anurans, documents highly conserved chromosomal evolution and gene orders in anurans, identifies rebel genes that might be important for frog evolution, and reveals a new sex-linked region with indel structural variants in anurans.

genomics↗

Searching for Sulfotyrosines (sY) in a HA(pY)STACK

Protein sulfation can be crucial in regulating protein-protein interactions but remains largely underexplored. Sulfation is near-isobaric to phosphorylation, making it particularly challenging to investigate using mass spectrometry. The degree to which tyrosine sulfation (sY) is misidentified as phosphorylation (pY) is thus an unresolved concern. This study explores the extent of sY misidentification within the human phosphoproteome by distinguishing between sulfation and phosphorylation based on their mass difference. Using Gaussian mixture models (GMMs), we screened [~]45M peptide-spectrum matches (PSMs) from the PeptideAtlas Human Phosphoproteome build for peptidoforms with mass error shifts indicative of sulfation. This analysis pinpointed 104 candidate sulfated peptidoforms, backed-up by Gene Ontology (GO) terms and custom terms linked to sulfation. False positive filtering by manual annotation resulted in 31 convincing peptidoforms spanning 7 known and 7 novel sY sites. Y47 in Calumenin was particularly intriguing since mass error shifts, acidic motif conservation, and MS2 neutral loss patterns characteristic of sulfation provided strong evidence that this site is sulfated rather than phosphorylated. Overall, although misidentification of sulfation in phosphoproteomics datasets derived from cell and tissue intracellular extracts can occur, it appears relatively rare and should not be considered a substantive confounding factor in high-quality phosphoproteomics datasets.

bioinformatics↗

Novel regulator Fpr2 controls immune homeostasis via CCL4-dependent neutrophils

Polymorphonuclear leukocytes (PMNs) in Fpr2-deficient mice have significantly impaired bactericidal activity, yet the precise mechanism remains elusive. Our research unveiled the cellular heterogeneity of peripheral blood PMNs through single-cell RNA-sequencing (scRNA-seq) and identified two new neutrophil clusters related to bacterial infection, including a sterilization cluster named Neu_CSTA and a regulation cluster named Neu_CCL4. The lack of Fpr2 leads to an immune regulation imbalance of Neu_CCL4 on other clusters in uninfected conditions, resulting in persistent instability of PMNs in peripheral blood, elevated inflammatory factors, and increased NOX2 expression. Furthermore, our findings corroborate that the regulatory function of Neu_CCL4 on PMNs immune balance is closely tied to its high expression of the anti-inflammatory ligand Anxa1. Regulon analysis inferred by scRNA-seq and ChIP-seq data suggested that a specific transcription factor Elf4, could modulate the expression of Anxa1, thereby facilitating its regulatory impact on other clusters. In the infection state, there was a noted increase in intercellular interactions across different clusters, leading to a general improvement in the bactericidal activity of PMNs. In summary, our research revealed distinct functional cellular sub-populations of PMNs, discovered the potential regulatory mechanisms, and elucidated the essential roles of Fpr2 in their ability to resist infection.

immunology↗

High-quality peptide evidence for annotating non-canonical open reading frames as human proteins

A major scientific drive is to characterize the protein-coding genome as it provides the primary basis for the study of human health. But the fundamental question remains: what has been missed in prior genomic analyses? Over the past decade, the translation of non-canonical open reading frames (ncORFs) has been observed across human cell types and disease states, with major implications for proteomics, genomics, and clinical science. However, the impact of ncORFs has been limited by the absence of a large-scale understanding of their contribution to the human proteome. Here, we report the collaborative efforts of stakeholders in proteomics, immunopeptidomics, Ribo-seq ORF discovery, and gene annotation, to produce a consensus landscape of protein-level evidence for ncORFs. We show that at least 25% of a set of 7,264 ncORFs give rise to translated gene products, yielding over 3,000 peptides in a pan-proteome analysis encompassing 3.8 billion mass spectra from 95,520 experiments. With these data, we developed an annotation framework for ncORFs and created public tools for researchers through GENCODE and PeptideAtlas. This work will provide a platform to advance ncORF-derived proteins in biomedical discovery and, beyond humans, diverse animals and plants where ncORFs are similarly observed.

molecular biology↗

Structural and molecular basis of the epistasis effect in enhanced affinity between SARS-CoV-2 KP.3 and ACE2

The recent emergence of SARS-CoV-2 variants KP.2 and KP.3 has been marked by mutations F456L/R346T and F456L/Q493E, respectively, which significantly impact the viruss interaction with human ACE2 and its resistance to neutralizing antibodies. KP.3, featuring F456L and Q493E, exhibits a markedly enhanced ACE2 binding affinity compared to KP.2 and the JN.1 variant due to synergistic effects between these mutations. This study elucidated the structures of KP.2 and KP.3 RBD in complex with ACE2 using cryogenic electron microscopy (Cryo-EM) and decipher the structural and thermodynamic implications of these mutations on receptor binding by molecular dynamics (MD) simulations, revealing that F456L mutation facilitates a more favorable binding environment for Q493E, leading to stronger receptor interactions which consequently enhance the potential for incorporating additional evasive mutations. These results underscore the importance of understanding mutational epistatic interactions in predicting SARS-CoV-2 evolution and optimizing vaccine updates. Continued monitoring of such epistatic effects is crucial for anticipating new dominant strains and preparing appropriate public health responses.

molecular biology↗

Competition and Compromise between Exogenous Probiotics and Native Microbiota

Probiotic interventions are effective strategies to modulate the gut microbiome, but how exogenous probiotics compete with native gut microbiota remains elusive. Here, we use a mouse model and a well-documented probiotic Bifidobacterium animalis subsp. lactis V9 (BV9) to mechanistically investigate its competitive strategies. We perform metagenomic and whole genome sequencing of stool samples and isolated BV9, longitudinally collected from 24 mice orally administered with BV9 and different diets. Results show that a high-fiber diet most effectively supports the colonization of BV9, where BV9 selectively competes with Parabacteroides distasonis (P. distasonis), rather than extensively with other gut bacteria. By comparing the genomic structures of BV9 and P. distasonis isolated during the washout period, we infer their co-evolution mechanisms, highlighting their competition and compromise in utilizing inulin-derived glucose. Finally, our in vitro co-culture experiments validate such competitive dynamics. This study fills a critical gap in our understanding of niche competition in colonization.

microbiology↗

A modified decision tree improves generalization across multiple brains proteomic data sets and reveals the role of ferroptosis in Alzheimer disease

Low generalization to the patient cohort and variety of experimental conditions in the proteomic search for disease biomarkers are among the main reasons for the bumpy road of quantitative proteomics from discovery stage to clinical validation. Only a small fraction of biomarkers discovered so far by proteomic analysis reaches clinical trials. Here, we presented a machine learning-based workflow for proteomics data analysis, which partially solves some of these issues. In particular, we used a customized decision tree model, which was regulated using a newly introduced parameter, min_cohorts_leaf, that resulted in better generalization of trained models. Further, we analyzed the trend of feature importances curve as a function of min_cohorts_leaf parameter and found that it could be used for accurate feature selection to obtain a list of proteins with significantly improved generalization. Finally, we demonstrated that the recently introduced DirectMS1 search algorithm for protein identification and quantitation provides a simple, yet, a highly efficient solution for the problem of combining multiple data sets obtained using different experimental settings. The developed workflow was tested using five published LC-MS/MS data sets obtained in the large consortia studies of Alzheimers disease brain samples. The selected data sets consist of 535 files in total analyzed using label-free single-shot data-dependent or data-independent acquisitions. Using the proposed modified ExtraTrees model we found that the expressions of two proteins involved in ferroptosis Serotransferrin TRFE and DNA repair nuclease/redox regulator APEX1, are important for explaining a lack of dementia for patients with the presence of neuritic plaques and neurofibrillary tangles.

molecular biology↗

Representation of visual uniformity in the lateral prefrontal cortex

Visual illusions tend to have early visual cortical correlates. However, this general trend may not apply to our subjective impression of a detailed and uniform visual world, which may be considered illusory given the paucity of peripheral processing. Using a psychophysically calibrated visual illusion, we assessed the patterns of hemodynamic activity in the human brain that distinguished between the illusory percept of uniformity in the periphery (i.e., Gabor patches having identical orientations) from the accurate perception of incoherence. We identified voxel patterns in the lateral prefrontal cortex that predicted perceived uniformity, which could also generalize to scene uniformity in naturalistic movies. Because similar representations of visual uniformity can also be found in the intermediate and late layers of a feedforward convolutional neural network, the perception of uniformity may involve high-level coding of abstract properties of the entire scene as a whole, that is distinct from the filling-in of specific details in early visual areas.

neuroscience↗

Multi-omic profiling of intraductal papillary neoplasms of the pancreas reveals distinct expression patterns and potential markers of progression

In order to advance our understanding of precancers in the pancreas, 69 pancreatic intraductal papillary neoplasms (IPNs), including 64 intraductal papillary mucinous neoplasms (IPMNs) and 5 intraductal oncocytic papillary neoplasms (IOPNs), 32 pancreatic cyst fluid samples, 104 invasive pancreatic ductal adenocarcinomas (PDACs), 43 normal adjacent tissues (NATs), and 76 macro-dissected normal pancreatic ducts (NDs) were analyzed by mass spectrometry. A total of 10,246 proteins and 22,284 glycopeptides were identified in all tissue samples, and 756 proteins with more than 1.5-fold increase in abundance in IPMNs relative to NDs were identified, 45% of which were also identified in cyst fluids. The over-expression of selected proteins was validated by immunolabeling. Proteins and glycoproteins overexpressed in IPMNs included those involved in glycan biosynthesis and the immune system. In addition, multiomics clustering identified two subtypes of IPMNs. This study provides a foundation for understanding tumor progression and targets for earlier detection and therapies. SignificanceThis multilevel characterization of intraductal papillary neoplasms of the pancreas provides a foundation for understanding the changes in protein and glycoprotein expression during the progression from normal duct to intraductal papillary neoplasm, and to invasive pancreatic carcinoma, providing a foundation for informed approaches to earlier detection and treatment.

cancer biology↗

Post-flowering photoperiod sensitivity of soybean in pod-setting responses

The development of soybean (Glycine max) is regulated by photoperiod, with genes related to photoperiod sensitivity primarily focused on flowering time. However, their roles in post-flowering reproductive development and the mechanisms by which photoperiod affects them are not yet determined. In this study, we found that pod formation is sensitive to photoperiod. Long-day (LD) conditions tend to extend the time from flowering to pod formation (R1 to R3 stage), and the first wave of flowers tends to fall off. Additionally, photoperiod affects pistil morphology; under short-day (SD) conditions, the stigma has a curved hook-like structure that facilitates better interaction with the filaments when pollen is released, ultimately influencing the timing of pod formation. Photoperiod-insensitive mutants, lacking E1 family and Evening Complex genes, showed no difference in pod formation time under LD or SD conditions. Hormone content analysis and transcriptome data analysis indicated that various hormones, ROS signals, and the application of sucrose solution in vitro might influence floral organ abscission. HighlightPhotoperiod sensitivity after flowering affects the pod-setting time in soybean.

plant biology↗

An orphan viral genome with controversial evolutionary status sheds light on a distinct lineage of flavi-like virus infecting plants

Advancements in high-throughput sequencing and associated bioinformatics methods have significantly expanded the RNA virus repertoire, including novel viruses with highly divergent genomes encoding orphan proteins that apparently lack homologous sequences. This absence of homologs in routine sequence similarity search complicates their taxonomic classification and raises a fundamental question: Do these orphan viral genomes represent bona fide viruses? In 2022, an orphan viral genome encoding a large polyprotein was identified in alfalfa (Medicago sativa) and named Snake River alfalfa virus (SRAV). Initially, SRAV was proposed to be within the flavi-like lineage of the family Flaviviridae. Subsequently, another research group showed its common occurrence in alfalfa but challenged its taxonomic position, suggesting it belongs to the family Endornaviridae rather than Flaviviridae. In this study, a large-scale analysis of 77 publicly available small RNA datasets indicated that SRAV could be detected across various tissues and cultivars of alfalfa, and has a broad geographical distribution. Moreover, profiles of the SRAV-derived small interfering RNAs (vsiRNAs) exhibited typical characteristics of virus in plant hosts. Through comprehensive evolutionary analysis, we demonstrated that SRAV should be a positive single-stranded RNA (ssRNA) flavi-like virus that infects alfalfa, rather than a member of the double-stranded RNA (dsRNA) of the family Endornaviridae. Our findings suggest that SRAV represents a unique class of plant-hosted flavi-like viruses with unusual genome organization and evolutionary status, differing from previously identified flavi-like viruses documented to infect plants. The latter shows a close evolutionary relationship to flavi-like viruses primarily found in plant-feeding invertebrates and lacks evidence of triggering host RNA interference (RNAi) responses so far. In summary, our study resolves the taxonomic controversy surrounding SRAV and suggests the potential existence of two distinct clades of plant-hosted flavi-like viruses with independent evolutionary origins. Furthermore, our research provides the first evidence of plant-hosted flavi-like viruses triggering the hosts RNAi antiviral response. The widespread occurrence of SRAV underscores its potential ecological significance in alfalfa, a crop of substantial economic importance.

evolutionary biology↗

Immunopipe: A comprehensive and flexible scRNA-seq and scTCR-seq data analysis pipeline

Single-cell sequencing technologies provide us with information at the level of individual cells. The combination of single-cell RNA-seq and single-cell TCR-seq profiling enables the exploration of cell heterogeneity and T-cell receptor repertoires simultaneously. The integration of both types of data can play a crucial role in enhancing our understanding of T-cell-mediated immunity and, in turn, facilitate the advancement of immunotherapy. Here, we present immunopipe, a comprehensive and flexible pipeline to perform integrated analysis of scRNA-seq and scTCR-seq data. In addition to the command line tool, we provide a user-friendly web interface for pipeline configuration and execution monitoring, benefiting researchers without extensive programming experience. With its comprehensive functionality and ease of use, immunopipe empowers researchers to uncover valuable insights from scRNA-seq and scTCR-seq data, ultimately advancing the understanding of immune responses and immunotherapy development.

bioinformatics↗

Multi-omics delineate growth factor network underlying exercise effects in an Alzheimer's mouse model

Physical exercise represents a primary defense against age-related cognitive decline and neurodegenerative disorders like Alzheimers disease (AD). To impartially investigate the underlying mechanisms, we conducted single-nucleus transcriptomic and chromatin accessibility analyses (snRNA-seq and ATAC-seq) on the hippocampus of mice carrying AD-linked NL-G-F mutations in the amyloid precursor protein gene (APPNL-G-F) following prolonged voluntary wheel-running exercise. Our study reveals that exercise mitigates amyloid-induced changes in both transcriptomic expression and chromatin accessibility through cell type-specific transcriptional regulatory networks. These networks converge on the activation of growth factor signaling pathways, particularly the epidermal growth factor receptor (EGFR) and insulin signaling, correlating with an increased proportion of immature dentate granule cells and oligodendrocytes. Notably, the beneficial effects of exercise on neurocognitive functions can be blocked by pharmacological inhibition of EGFR and the downstream phosphoinositide 3-kinases (PI3K). Furthermore, exercise leads to elevated levels of heparin-binding EGF (HB-EGF) in the blood, and intranasal administration of HB-EGF enhances memory function in sedentary APPNL-G-F mice. These findings offer a panoramic delineation of cell type-specific hippocampal transcriptional networks activated by exercise and suggest EGF-related growth factor signaling as a druggable contributor to exercise-induced memory enhancement, thereby suggesting therapeutic avenues for combatting AD-related cognitive decline.

animal behavior and cognition↗

Rational Design of Live Biotherapeutic Products for the Prevention of Clostridioides difficile Infection

Clostridioides difficile infection (CDI) is one of the leading causes of healthcare- and antibiotic-associated diarrhea. While fecal microbiota transplantation (FMT) has emerged as a promising therapy for recurrent CDI, its exact mechanisms of action and long-term safety are not fully understood. Defined consortia of clonal bacterial isolates, known as live biotherapeutic products (LBPs), have been proposed as an alternative therapeutic option. However, the rational design of LBPs remains challenging. Here, we employ a computational pipeline and three independent metagenomic datasets to systematically identify microbial strains that have the potential to inhibit CDI. We first constructed the CDI-related microbial genome catalog, comprising 3,741 non-redundant metagenome-assembled genomes (nrMAGs) at the strain level. We then identified multiple potential protective nrMAGs that can be candidates for the design of microbial consortia targeting CDI, including strains from Dorea formicigenerans, Oscillibacter welbionis, and Faecalibacterium prausnitzii. Importantly, some of these potential protective nrMAGs were found to play an important role in the success of FMT, and the majority of the top protective nrMAGs can be validated by various previously reported findings. Our results demonstrate a computational framework for the rational selection of microbial strains targeting CDI, paving the way for the computational design of microbial consortia against other enteric infections.

microbiology↗

Domainator, a flexible software suite for domain-based annotation and neighborhood analysis, identifies proteins involved in antiviral systems

The availability of large databases of biological sequences presents an opportunity for in-depth exploration of gene diversity and function. Bacterial defense systems are a rich source of diverse, but difficult to annotate genes with biotechnological applications. In this work, we present Domainator, a flexible and modular software suite for domain-based gene neighborhood and protein search, extraction, and clustering. We demonstrate the utility of Domainator through three examples related to bacterial defense systems. First, we cluster CRISPR-associated Rossman fold (CARF) containing proteins with difficult to annotate effector domains, classifying most of them as likely transcriptional regulators and a subset as likely RNAses. Second, we extract and cluster P4-like phage satellite defense hotspots and identify an abundant system related to Lamassu phage defense systems. Third, we integrate a protein language model into Domainator and use it to identify restriction enzymes with low homology to known reference sequences, validating the activity of one example in-vitro. Domainator is made available as an open-source package with detailed documentation and usage examples.

bioinformatics↗

MetaX: A peptide centric metaproteomic data analysis platform using Operational Taxa-Functions (OTF)

Metaproteomics analyzes the functional dynamics of microbial communities by identifying peptides and mapping them to the most likely proteins and taxa. The challenge in this field lies in seamlessly integrating taxonomic and functional annotations to accurately represent the contributions of individual microbial taxa to functional diversity. We introduce MetaX, a comprehensive tool for analyzing taxa-function relationships in metaproteomics by mapping peptides to their lowest common ancestors and assigning functions based on proportional thresholds, ensuring accurate peptide-level mappings. Importantly, MetaX introduces the Operational Taxa-Functions (OTF), a new conceptual unit for exploring microbial roles and interactions within ecosystems. Additionally, MetaX extends traditional taxonomic classification by adding a genome level below the species level, enhancing the accuracy of function attribution to specific genomes. We demonstrated MetaX by reanalyzing metaproteomic data from gut microbiomes exposed to various sweeteners, achieving results similar to traditional protein analysis. Furthermore, using the peptide-centric approach and OTF, we observed that Parabacteroides distasonis significantly responds to certain sweeteners, highlighting its role in modifying specific metabolic functions. With its intuitive, user-friendly interface, MetaX facilitates detailed study of the complex interactions between microbial taxa and their functions in metaproteomics. It enhances our understanding of microbial roles in ecosystems and health.

bioinformatics↗

MetaDIA: A Novel Database Reduction Strategy for DIA Human Gut Metaproteomics

BackgroundMicrobiomes, especially within the gut, are complex and may comprise hundreds of species. The identification of peptides in metaproteomics presents a significant challenge, as it involves matching peptides to mass spectra within an enormous search space for complex and unknown samples. This poses difficulties for both the accuracy and the speed of identification. Specifically, analysis of data-independent acquisition (DIA) datasets has relied on libraries constructed from prior data-dependent acquisition (DDA) results. This approach requires running the samples in DDA mode to construct a library from the identified results, which can then be used for the DIA data. However, this method is resource-intensive, consumes samples, and limits identification to peptides previously identified by DDA. These limitations restrict the application of DIA in metaproteomics research. ResultsWe introduced a novel strategy to reduce the search space by utilizing species abundance and functional abundance information from the microbiome to score each peptide and prioritize those most likely to be detected. Employing this strategy, we have developed and optimized a workflow called MetaDIA for analysis of microbiome DIA data, which operates independently of DDA assistance. Our method demonstrated strong consistency with the traditional DDA-based library approach at both protein and functional levels. ConclusionOur approach successfully created a smaller, yet sufficient database for DIA data search requirements in metaproteomics, showing high consistency with results from the conventional DDA-based library. We believe this method can facilitate the application of DIA in metaproteomics.

bioinformatics↗