Biology subjects

Liu, Y.

Publications and source records attributed to Liu, Y..

At least 1,639 records · Page 91Linked to original sources

bioRxiv2023

Network-based elucidation of colon cancer drug resistance by phosphoproteomic time-series analysis

Aberrant signaling pathway activity is a hallmark of tumorigenesis and progression, which has guided targeted inhibitor design for over 30 years. Yet, adaptive resistance mechanisms, induced by rapid, context-specific signaling network rewiring, continue to challenge therapeutic efficacy. By leveraging progress in proteomic technologies and network-based methodologies, over the past decade, we developed VESPA--an algorithm designed to elucidate mechanisms of cell response and adaptation to drug perturbations--and used it to analyze 7-point phosphoproteomic time series from colorectal cancer cells treated with clinically-relevant inhibitors and control media. Interrogation of tumor-specific enzyme/substrate interactions accurately inferred kinase and phosphatase activity, based on their inferred substrate phosphorylation state, effectively accounting for signal cross-talk and sparse phosphoproteome coverage. The analysis elucidated time-dependent signaling pathway response to each drug perturbation and, more importantly, cell adaptive response and rewiring that was experimentally confirmed by CRISPRko assays, suggesting broad applicability to cancer and other diseases.

systems biology↗

bioRxiv2023

Semi-conservative transmission of DNA N6-adenine methylation in a unicellular eukaryote

While DNA N6-adenine methylation (6mA) is best known in prokaryotes, its presence in eukaryotes has generated great interest recently. Biochemical and genetic evidence supports that AMT1, a MT-A70 family methyltransferase (MTase), is crucial for 6mA deposition in unicellular eukaryotes. Nonetheless, 6mA transmission mechanism remains to be elucidated. Taking advantage of Single Molecule Real-Time Circular Consensus Sequencing (SMRT CCS), here we provide definitive evidence for semi-conservative transmission of 6mA, showcased in the unicellular eukaryote Tetrahymena thermophila. In wildtype (WT) cells, 6mA occurs at the self-complementary ApT dinucleotide, mostly in full methylation (full-6mApT); hemi-methylation (hemi-6mApT) is transiently present on the parental strand of newly replicated DNA. In {Delta}AMT1 cells, 6mA predominantly occurs as hemi-6mApT. Hemi-to-full conversion in WT cells is fast, robust, and likely processive, while de novo 6mA deposition in {Delta}AMT1 cells is slow and sporadic. In Tetrahymena, regularly spaced 6mA clusters coincide with linker DNA of the canonical nucleosome arrays in the gene body. Importantly, in vitro methylation of human chromatin by reconstituted AMT1 complex recapitulates preferential targeting of hemi-6mApT sites in linker DNA, supporting AMT1s intrinsic and autonomous role in maintenance methylation. We conclude that 6mA is transmitted by a semi-conservative mechanism: full-6mApT is split by DNA replication into hemi-6mApT, which is restored to full-6mApT by AMT1-dependent maintenance methylation. Our study dissects AMT1-dependent maintenance methylation and AMT1-independent de novo methylation, reveals a molecular pathway for 6mA transmission with striking similarity to 5-methyl cytosine (5mC) transmission at the CpG dinucleotide, and establishes 6mA as a bona fide eukaryotic epigenetic mark.

molecular biology↗

bioRxiv2023

SeqScreen-Nano: a computational platform for rapid, in-field characterization of previously unseen pathogens.

The COVID-19 pandemic forever underscored the need for biosurveillance platforms capable of rapid detection of previously unseen pathogens. Oxford Nanopore Technology (ONT) couples long-read sequencing with in-field capability, opening the door to real-time, in-field biosurveillance. Though a promising technology, streaming assignment of accurate functional and taxonomic labels with nanopore reads remains challenging given: (i) individual reads can span multiple genes, (ii) individual reads may contain truncated genes, and pseudogenes, (iii) the error rate of the ONT platform that may introduce frameshifts and missense errors, and (iv) the computational costs of read-by-read analysis may exceed that of in-field computational equipment. Altogether, these challenges highlight a need for novel computational approaches. To this end, we describe SeqSeqscreen-Nano, a novel and portable computational platform for the characterization of novel pathogens. Based on results from simulated and synthetic microbial communities, SeqScreen-Nano can identify Open Reading Frames (ORFs) across the length of raw ONT reads and then use the predicted ORFs for accurate functional characterization and taxonomic classification. SeqScreen-Nano can run efficiently in a memory-constrained environment (less than 32GB of RAM), allowing it to be utilized in resource-limited settings. SeqScreen-Nano can also process reads directly from the ONT MinlON sequencing device, enabling rapid, in-field characterization of previously unseen pathogens. SeqScreen-Nano (v4.0) is available on GitLab at: https://gitlab.com/treangenlab/seqscreen

bioinformatics↗

bioRxiv2023

Olivar: fully automated and variant aware primer design for multiplex tiled amplicon sequencing of pathogen genomes

Tiled amplicon sequencing has served as an essential tool for tracking the spread and evolution of pathogens. Over 2 million complete SARS-CoV-2 genomes are now publicly available, most sequenced and assembled via tiled amplicon sequencing. While computational tools for tiled amplicon design exist, they require downstream manual optimization both computationally and experimentally, which is slow and costly. Here we present Olivar, a first step towards a fully automated, variant-aware design of tiled amplicons for pathogen genomes. Olivar converts each nucleotide of the target genome into a numeric risk score, capturing undesired sequence features that should be avoided. In a direct comparison with PrimalScheme, we show that Olivar has fewer SNPs overlapping with primers and predicted PCR byproducts. We also compared Olivar head-to-head with ARTIC v4.1, the most widely used primer set for SARS-CoV-2 sequencing, and show Olivar yields similar read mapping rates ([~]90%) and better coverage to the manually designed ARTIC v4.1 amplicons. We also evaluated Olivar on real wastewater samples and found that Olivar had up to 3-fold higher mapping rates while retaining similar coverage. In summary, Olivar automates and accelerates the generation of tiled amplicons, even in situations of high mutation frequency and/or density. Olivar is available as a web application at https://olivar.rice.edu. Olivar can also be installed locally as a command line tool with Bioconda. Source code, installation guide and usage are available at https://github.com/treangenlab/Olivar.

bioinformatics↗

bioRxiv2023

Short Tandem Repeats of Human Genome Are Intrinsically Unstable in Cultured Cells in vivo

Short tandem repeats (STRs) are a class of abundant structural or functional elements in the human genome and exhibit a polymorphic nature of repeat length and genetic variation within human populations. Interestingly, STR expansions underlie about 60 neurological disorders. However, "stutter" artifacts or noises render it difficult to investigate the pathogenesis of STR expansions. Here, we systematically investigated STR instability in cultured human cells using GC-rich CAG and AT-rich ATTCT tandem repeats as examples. We found that triplicate bidirectional Sanger sequencing with PCR amplification under proper conditions can reliably assess STR length. In addition, we found that next-generation sequencing with paired-end reads bidirectionally covering STR regions can accurately and reliably assay STR length. Finally, we found that STRs are intrinsically unstable in cultured human cell populations and during single-cell cloning. Our data suggest a general method for accurately and reliably assessing STR length and have important implications in investigating pathogenesis of STR expansion diseases.

genetics↗

bioRxiv2023

BHLHE40/41 regulate macrophage/microglia responses associated with Alzheimer's disease and other disorders of lipid-rich tissues

BackgroundGenetic and experimental evidence strongly implicates myeloid cells in the etiology of AD and suggests that AD-associated alleles and genes may modulate disease risk by altering the transcriptional and cellular responses of macrophages (like microglia) to damage of lipid-rich tissues (like the brain). Specifically, recent single-cell/nucleus RNA sequencing (sc/nRNA-seq) studies identified a transcriptionally distinct state of subsets of macrophages in aging or degenerating brains (usually referred to as disease- associated microglia or DAM) and in other diseased lipid-rich tissues (e.g., obese adipose tissue, fatty liver, and atherosclerotic plaques). We collectively refer to these subpopulations as lipid-associated macrophages or LAMs. Importantly, this particular activation state is characterized by increased expression of genes involved in the phagocytic clearance of lipid-rich cellular debris (efferocytosis), including several AD risk genes. MethodsWe used sc/nRNA-seq data from human and mouse microglia from healthy and diseased brains and macrophages from other lipid-rich tissues to reconstruct gene regulatory networks and identify transcriptional regulators whose regulons are enriched for LAM response genes (LAM TFs) across species. We then used gene knock- down/knock-out strategies to validate some of these LAM TFs in human THP-1 macrophages and iPSC-derived microglia in vitro, as well as mouse microglia in vivo. ResultsWe nominate 11 strong candidate LAM TFs shared across human and mouse networks (BHLHE41, HIF1A, ID2, JUNB, MAF, MAFB, MEF2A, MEF2C, NACA, POU2F2 and SPI1). We also demonstrate a strong enrichment of AD risk alleles in the cistrome of BHLHE41 (and its close homolog BHLHE40), thus implicating its regulon in the modulation of disease susceptibility. Loss or reduction of BHLHE40/41 expression in human THP-1 macrophages and iPSC-derived microglia, as well as loss of Bhlhe40/41 in mouse microglia led to increased expression of LAM response genes, specifically those involved in cholesterol clearance and lysosomal processing, with a concomitant increase in cholesterol efflux and storage, as well as lysosomal mass and degradative capacity. ConclusionsTaken together, this study nominates transcriptional regulators of the LAM response, experimentally validates BHLHE40/41 in human and mouse macrophages/microglia, and provides novel targets for therapeutic modulation of macrophage/microglia function in AD and other disorders of lipid-rich tissues. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=95 SRC="FIGDIR/small/528372v1_ufig1.gif" ALT="Figure 1"> View larger version (22K): org.highwire.dtl.DTLVardef@10f356forg.highwire.dtl.DTLVardef@17d259forg.highwire.dtl.DTLVardef@1312809org.highwire.dtl.DTLVardef@3b6a8f_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2023

Learning virus genotype-fitness landscape in embedding space

The relationship between genotype and fitness is fundamental to evolution, but quantitatively mapping genotypes to fitness has remained challenging. We propose the Phenotypic-Embedding theorem (P-E theorem) that bridges genotype-phenotype through an encoder-decoder deep learning framework. Inspired by this, we proposed a more general first principle for correlating genotype-phenotype, and the Phenotypic-Embedding theorem provides a computable basis for the application of first principle. As an application example of the P-E theorem, we developed the Co-attention based Transformer model to bridge Genotype and Fitness (CoT2G-F) model, a Transformer-based pre-train foundation model with downstream supervised fine-tuning (SFT) that can accurately simulate the neutral evolution of viruses and predict immune escape mutations. Accordingly, following the calculation path of the P-E theorem, we accurately obtained the basic reproduction number (R0) of SARS-CoV-2 from first principles, quantitatively linked immune escape to viral fitness, and plotted the genotype-fitness landscape. The theoretical system we established provides a general and interpretable method to construct genotype-phenotype landscapes, providing a new paradigm for studying theoretical and computational biology.

evolutionary biology↗

bioRxiv2023

Exploring the Knowledge of An Outstanding Protein to Protein Interaction Transformer

Protein-to-protein interaction (PPI) prediction aims to predict whether two given proteins interact or not. Compared with traditional experimental methods of high cost and low efficiency, the current deep learning based approach makes it possible to discover massive potential PPIs from large-scale databases. However, deep PPI prediction models perform poorly on unseen species, as their proteins are not in the training set. Targetting on this issue, the paper first proposes PPITrans, a Transformer based PPI prediction model that exploits a language model pre-trained on proteins to conduct binary PPI prediction. To validate the effectiveness on unseen species, PPITrans is trained with Human PPIs and tested on PPIs of other species. Experimental results show that PPITrans significantly outperforms the previous state-of-the-art on various metrics, especially on PPIs of unseen species. For example, the AUPR improves 0.339 absolutely on Fly PPIs. Aiming to explore the knowledge learned by PPITrans from PPI data, this paper also designs a series of probes belonging to three categories. Their results reveal several interesting findings, like that although PPITrans cannot capture the spatial structure of proteins, it can obtain knowledge of PPI type and binding affinity, learning more than binary PPI.

bioinformatics↗

bioRxiv2023

Multivariate adaptive shrinkage improves cross-population transcriptome prediction for transcriptome-wide association studies in underrepresented populations

Transcriptome prediction models built with data from European-descent individuals are less accurate when applied to different populations because of differences in linkage disequilibrium patterns and allele frequencies. We hypothesized methods that leverage shared regulatory effects across different conditions, in this case, across different populations may improve cross-population transcriptome prediction. To test this hypothesis, we made transcriptome prediction models for use in transcriptome-wide association studies (TWAS) using different methods (Elastic Net, Joint-Tissue Imputation (JTI), Matrix eQTL, Multivariate Adaptive Shrinkage in R (MASHR), and Transcriptome-Integrated Genetic Association Resource (TIGAR)) and tested their out-of-sample transcriptome prediction accuracy in population-matched and cross-population scenarios. Additionally, to evaluate model applicability in TWAS, we integrated publicly available multi-ethnic genome-wide association study (GWAS) summary statistics from the Population Architecture using Genomics and Epidemiology Study (PAGE) and Pan-UK Biobank with our developed transcriptome prediction models. In regard to transcriptome prediction accuracy, MASHR models performed better or the same as other methods in both population-matched and cross-population transcriptome predictions. Furthermore, in multi-ethnic TWAS, MASHR models yielded more discoveries that replicate in both PAGE and PanUKBB across all methods analyzed, including loci previously mapped in GWAS and new loci previously not found in GWAS. Overall, our study demonstrates the importance of using methods that benefit from different populations effect size estimates in order to improve TWAS for multi-ethnic or underrepresented populations.

genomics↗

bioRxiv2023

A FACT-ETS-1 Antiviral Response Pathway Restricts Viral Replication and is Countered by Poxvirus A51R Proteins

The FACT complex is an ancient chromatin remodeling factor comprised of Spt16 and SSRP1 subunits that regulates specific eukaryotic gene expression programs. However, whether FACT regulates host immune responses to infection was unclear. Here, we identify an antiviral pathway mediated by FACT, distinct from the interferon response, that restricts poxvirus replication. We show that early viral gene expression triggers nuclear accumulation of specialized, SUMOylated Spt16 subunits of FACT required for expression of ETS-1, a downstream transcription factor that activates a virus restriction program. However, poxvirus-encoded A51R proteins block ETS-1 expression by outcompeting SSRP1 for binding to SUMOylated Spt16 in the cytosol and by tethering SUMOylated Spt16 to microtubules. Moreover, we show that A51R antagonism of FACT enhances both poxvirus replication in human cells and viral virulence in mice. Finally, we demonstrate that FACT also restricts unrelated RNA viruses, suggesting a broad role for FACT in antiviral immunity. Our study reveals the FACT-ETS-1 Antiviral Response (FEAR) pathway to be critical for eukaryotic antiviral immunity and describes a unique mechanism of viral immune evasion.

microbiology↗

bioRxiv2023

Syntaxin of plants 32 regulates pollen wall development and pollen tube cell wall integrity via controlling secretory pathway

Pollen tubes (PTs) elongate in a polar way to deliver sperm cells to the ovule. Pollen wall development and PT cell wall integrity (CWI) maintenance are critical for PT growth and double fertilization. Pollen wall development mainly relies on secretion of exine precursors in tapetum. RALF4/19-ANX/BUPS-MRI and RALF4/19-LRX-AUN are two distinct signaling pathways but converge to fine-tune CWI during PT growth. Here, we discovered that atsyp32+/-, AtSYP32 RNAi and AtSYP3132 RNAi lines were male sterile. The tapetum development in these lines were disturbed, and the pollen wall structure was impaired resulting in pollen grain and tube bursting and less PTs navigated to micropyles. Strikingly, there were numerous ectopic secretory vesicles retained in pollen cytoplasm, and the abundance or distribution of polysaccharides and AGPs altered significantly in PTs of the mutants and RNAi lines. AtSYP32 interacted with the vesicle transport regulators SEC31B, SEC22 and BET12, the PT CWI regulators RALF19 and LRX11, and the XyG xylosyltransferase XXT5, in the Golgi apparatus. Transcription of some genes related to pollen wall biosynthesis and PT CWI maintenance were seriously affected by AtSYP32 downregulation. Our findings illustrate that AtSYP32 plays essential roles in pollen wall development and PT CWI maintenance via controlling secretory pathway. IN A NUTSHELLO_ST_ABSBackgroundC_ST_ABSPollen wall is the most complex cell wall. Pollen wall development mainly relies on secretion of precursors of exine and pollen coat in tapetal cells. Pollen tubes (PTs) grow in a polar way to deliver sperm cells to the ovule. Maintenance of PT cell wall integrity (CWI) is critical for PT elongation and double fertilization. RALF4/19 ligands interact with BUPS-ANX receptors, signaling it in an autocrine manner to maintain CWI during PT elongation. RALF4/19-LRX-AUN pathway is distinct with RALF4/19-ANX/BUPS-MRI pathway but they converge to fine-tune CWI during PT growth. Biosynthesis of PT cell wall involves multiple subcellular compartments and vesicle transport pathways. Golgi apparatus acts as a hub in vesicle trafficking. Golgi-syntaxin AtSYP31 and AtSYP32 regulate pollen development by controlling intra-Golgi transport and Golgi morphology QuestionWhat is AtSYP32 role in pollen wall and tapetum development? Who are the AtSYP32 partners that regulate secretion of cell wall biosynthesis materials? FindingsWe found that no homozygote progeny was obtained from self-pollinated atsyp32+/- alleles due to pollen sterile. The tapetum development and degeneration in atsyp32+/- mutants was severely delayed, and the pollen wall and PT wall structure were impaired. Strikingly, there were numerous ectopic secretory vesicles retained in pollen cytoplasm in atsyp32+/- mutants, and the abundance or distribution of PT wall polysaccharides and AGPs altered obviously. AtSYP32 interacted with the vesicle transport regulators SEC31B, SEC22 and BET12, the PT CWI regulators RALF19 and LRX11, and XyG xylosyltransferase XXT5, in the Golgi. All these highlight that AtSYP32 regulates pollen wall development and maintenance of PT CWI via controlling secretory pathway. Next stepsThe biological significances and the molecular mechanisms of AtSYP32 interacting with XXT5, RALF19 and LRX11 are elusive but thought-provoking. We are going to clarify the mechanisms.

molecular biology↗

bioRxiv2023

Single-cell transcriptomic analyses reveal the cellular and genetic basis of aquatic locomotion in scyphozoan jellyfish

The authors have withdrawn their manuscript because the authors need to re-organize the data and writing. More experimental evidence from whole-mount ISH assay and RNAi assays will be added to support the viewpoints. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

ecology↗

bioRxiv2023

Pathogen-driven CRISPR screens identify TREX1 as a regulator of DNA self-sensing during influenza virus infection

Intracellular pathogens interact with host factors, exploiting those that enhance replication while countering those that suppress it. Genetic screens have begun to define the host:pathogen interface and establish a mechanistic basis for host-directed therapies. Yet, limitations of current approaches leave large regions of this interface unexplored. To uncover host factors with pro-pathogen functions, we developed a novel fitness-based screen that queries factors important during the middle-to-late stages of infection. This was achieved by engineering influenza virus to direct the screen by programing dCas9 to modulate host gene expression. A genome-wide screen identified the cytoplasmic DNA exonuclease TREX1 as a potent pro-viral factor. TREX1 normally degrades cytoplasmic DNA to prevent inappropriate innate immune activation by self DNA. Our mechanistic studies revealed that this same process functions during influenza virus infection to enhance replication. Infection triggered release of mitochondrial DNA into the cytoplasm, activating antiviral signaling via cGAS and STING. TREX1 metabolized the mitochondrial DNA preventing its sensing. Collectively, these data show that self-DNA is deployed to amplify host innate sensing during RNA virus infection, a process tempered by TREX1. Moreover, they demonstrate the power and generality of pathogen driven fitness-based screens to pinpoint key host regulators of intracellular pathogens.

microbiology↗

bioRxiv2023

Excess PrPC inhibits muscle cell differentiation via miRNA-enhanced liquid-liquid phase separation implicated in myopathy

The cellular prion protein (PrPC), a glycoprotein existing in membrane-bound and cytoplasmic forms, has functional importance in skeletal muscle, but the mechanism behind the phenomenon remains poorly understood. Here we report that PrPC is overexpressed and located in the cytoplasm of the skeletal muscle of six myopathy patients; cytoplasmic PrPC strongly inhibits skeletal muscle cell autophagy and blocks myoblast differentiation. PrPC selectively binds to a subset of miRNAs during myoblast differentiation, and the co-localization of PrPC with miR-214-3p was clearly observed in the skeletal muscle of six myopathy patients but not in that of four age-matched controls. We demonstrate that PrPC is overexpressed in skeletal muscle cells under pathological conditions and inhibits muscle cell differentiation via physically interacting with a subset of miRNAs to significantly inhibit autophagy-related protein 5-dependent autophagy, and selectively recruits these miRNAs into phase-separated condensates in living myoblasts, which in turn greatly enhances liquid-liquid phase separation (LLPS) of PrPC and results in the subsequent PrP aggregation and muscle bundle formation in myopathy patients characterized by incomplete muscle regeneration. Our findings show how excess PrPC can inhibit muscle cell differentiation via miRNA-enhanced LLPS implicated in myopathy.

biochemistry↗

bioRxiv2023

SoyOmics: A deeply integrated database on soybean multi omics

As one of the most important crops to supply majority plant oil and protein for the whole world, soybean is facing an increasing global demand. Up to now, vast multi-omics data of soybean were generated, thereby providing valuable resources for functional study and molecular breeding. Nevertheless, it is tremendously challenging for researchers to deal with these big multi-omics data, particularly considering the unprecedented rate of data growth. Therefore, we collect the reported high-quality omics, including assembly genomes, graph pan-genome, resequencing and phenotypic data of representative germplasms, transcriptomic and epigenomic data from different tissues, organs and accessions, and construct an integrated soybean multi-omics database, named SoyOmics (https://ngdc.cncb.ac.cn/soyomics). By equipping with multiple analysis modules and toolkits, SoyOmics is of great utility to facilitate the global scientific community to fully use these big omics datasets for a wide range of soybean studies from fundamental functional investigation to molecular breeding.

bioinformatics↗

bioRxiv2023

IMPACT: a web server for exploring immunotherapeutic predictive and cancer prognostic biomarkers

Immune checkpoint inhibitors (ICIs) are a breakthrough in oncology treatment, and studies of screening predictive biomarkers of ICIs are emerging. We developed a web server named IMPACT (http://impact.brbiotech.com/) to thoroughly explore immunotherapeutic predictive or prognostic biomarkers. IMPACT contains a large dataset of 6,276 patients treated with ICIs and integrates 11 well-designed function modules, enabling an in-depth solution for biomarkers exploration. Compared with the existing tools, IMPACT was implemented with one exclusive module for interaction analysis and several optimized conventional functions for discovering novel biomarkers. Specifically, the interaction analysis of biomarker-treatment effect is essential to determine whether a biomarker is predictive and/or prognostic for ICIs. Moreover, several optimized functions allow complicated biomarker exploration, including customized selections of variant types in more detail, automatically screening meaningful co-mutations among multiple genes, and selecting cut-off values for gene expression biomarkers. In summary, IMPACT is a comprehensive analysis resource to facilitate biomarker research of ICIs.

bioinformatics↗

bioRxiv2023

ADO-MEDIATED SYNTHESIS OF TAURINE ALTERS THE CHROMATIN LANDSCAPE OF INGUINAL ADIPOSE TISSUE TO ENHANCE NON-SHIVERING THERMOGENESIS

Non-shivering thermogenesis (NST) has strong potential to combat obesity, however, a safe molecular approach to activate this process has not yet been identified. The sulfur amino acid taurine has the ability to safely activate NST and confer protection against obesity and metabolic disease in both mice and humans, but the mechanism of action is unknown. In this study, we discover that a suite of taurine biosynthetic enzymes, especially that of cysteamine dioxygenase (ADO), significantly increases in response to {beta}3 adrenergic signaling in inguinal tissues (IWAT) in order increase intracellular concentrations of taurine. We further show that ADO is critical for thermogenic mitochondrial function as its ablation in thermogenic adipocytes significantly reduces taurine levels which lead to declines in mitochondrial oxygen consumption rates. Finally, we demonstrate via assay for transposase-accessible chromatin with sequencing (ATAC-Seq) that taurine supplementation has the ability to remodel the chromatin landscape to increase the chromatin accessibility and transcription of genes, such as glucose-6-phosphate isomerase 1 (Gpi1), that are critical for NST. Taken together, our studies highlight a potential mechanism for taurine in the activation of NST that can be leveraged toward the treatment of obesity and metabolic disease.

cell biology↗

bioRxiv2023

Programmable peroxidase-assisted signal amplification enables flexible detection of nucleic acid targets in cellular and histopathological specimens

In situ hybridization (ISH) is a powerful tool for investigating the spatial arrangement of nucleic acid targets in fixed samples. ISH is typically visualized using fluorophores to allow high sensitivity and multiplexing or with colorimetric labels to facilitate co-visualization with histopathological stains. Both approaches benefit from signal amplification, which makes target detection effective, rapid, and compatible with a broad range of optical systems. Here, we introduce a unified technical platform, termed pSABER, for the amplification of ISH signals in cell and tissue systems. pSABER decorates the in situ target with concatemeric binding sites for a horseradish peroxidase-conjugated oligonucleotide which can then catalyze the massive localized deposition of fluorescent or colorimetric substrates. We demonstrate that pSABER effectively labels DNA and RNA targets, works robustly in cultured cells and challenging formalin fixed paraffin embedded (FFPE) specimens. Furthermore, pSABER can achieve 25-fold signal amplification over conventional signal amplification by exchange reaction (SABER) and can be serially multiplexed using solution exchange. Therefore, by linking nucleic acid detection to robust signal amplification capable of diverse readouts, pSABER will have broad utility in research and clinical settings.

genomics↗