Search bioRxiv⌕ Search

Biology subjects

Wong, B.

Publications and source records attributed to Wong, B..

At least 19 recordsLinked to original sources

Mapping Functional Tumor Suppressor Networks in Esophageal Adenocarcinoma Using In Vivo CRISPR Screening and Perturb-sequencing

Esophageal adenocarcinoma (EAC) is a genetically heterogeneous malignancy with few recurrent drivers, limiting effective targeted therapies. Although EAC arises from Barretts esophagus (BE), mechanisms driving progression from this premalignant state to invasive cancer remain unclear. We combined pooled CRISPR-Cas9 loss-of-function screening, in vivo tumorigenicity assays, and Perturb-seq profiling to define functional drivers of BE transformation. We identified 37 tumor suppressors whose loss promotes progression to EAC, defining a functional landscape of tumor initiation. Despite genetic diversity, these losses converged on four transcriptional programs involving metabolic reprogramming, cell cycle progression, RNA processing, and cellular motility. Furthermore, we identify loss of NIPBL, TGFBR2, and RPL22 as key mediators of resistance to platinum- and taxane-based chemotherapy. Collectively, these findings provide a unifying framework for genomic heterogeneity in EAC, uncover underappreciated tumor suppressor pathways, and establish a resource to guide mechanistic and translational studies aimed at improving treatment strategies in this aggressive cancer.

cancer biology↗

Diffusion Latent Representations for Neural Decoding

Neural decoding can be viewed as a representation learning problem in which neural activity is mapped into an intermediate representation before downstream reconstruction. The choice of intermediate representation influences both performance and learning difficulty. Here we developed a novel framework for studying how intermediate representation choice influences downstream learning and reconstruction. As a proof-of-concept, we instantiated our framework using diffusion latent representations extracted from different diffusion timesteps for neural speech decoding. Component-wise evaluation showed that reconstruction performance differed substantially across diffusion timesteps, with teacher-forced Word Error Rates of 44.7%, 7.5%, and 3.5% for different latent models. These results demonstrate that diffusion latent representations can serve as effective intermediate representations for learning from neural activity, but that their effectiveness depends strongly on the selected diffusion timestep. More broadly, our framework provides a basis for systematically studying how intermediate representation choice influences downstream learning and reconstruction.

neuroscience↗

Open-source, Hardware-Independent GPU Acceleration for Scalable Nanopore Basecalling with Slorado and Openfish

Nanopore sequencing technologies are used widely in genomics research and their adoption continues to accelerate. 'Basecalling' is an essential step in the nanopore sequencing workflow, during which raw electrical signals are translated into nucleotide sequences. The current state-of-the-art basecaller, Oxford Nanopore Technologies (ONT) software 'Dorado,' relies on proprietary, platform-specific NVIDIA GPU optimisations bundled in the closed-source 'Koi' library. As a result, practical, high-speed basecalling is effectively restricted to a narrow class of supported hardware, limiting accessibility, portability, and innovation. We present (1) 'Openfish,' an open-source GPU-accelerated nanopore basecaller decoding library that provides a competitive alternative to ONT's proprietary Koi library; and (2) Slorado, a fully open-source basecalling framework that supports both DNA and RNA with equivalent accuracy to Dorado. Together, Openfish and Slorado remove the hardware lock-in that currently limits high-performance nanopore basecalling. Our framework scales efficiently across heterogeneous computing environments, from low-power embedded devices to GPU-equipped datacenters, without sacrificing speed or accuracy. Openfish and Slorado are available as free open-source packages for basecalling research, optimisation and deployment beyond the constraints of proprietary software and hardware ecosystems: Openfish: https://github.com/warp9seq/openfish, Slorado: https://github.com/BonsonW/slorado.

bioinformatics↗

Association of OXA-1 and TEM-1 Genes with Antibiotic Resistance to Piperacillin/Tazobactam in ESBL-Producing Pathogens: Insights from a Multi-Center Analysis

BackgroundThe emergence of extended-spectrum {beta}-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae presents significant challenges in treating infections caused by these pathogens. This multi-center retrospective study investigated the prevalence of OXA-1 and TEM-1 genes in ESBL-producing E. coli and K. pneumoniae, along with their association with piperacillin/tazobactam susceptibility. MethodsClinical isolates were collected from three institutions as part of routine patient care: Tripler Army Medical Center (TAMC) in Hawaii, Madigan Army Medical Center (MAMC) in Washington, and Brooke Army Medical Center (BAMC) in Southern Texas. A total of 416 isolates were analyzed through genome sequencing and CLSI-guided susceptibility testing. ResultsOXA-1 and TEM-1 {beta}-lactamase enzymes were present in 20.9% (73/349) and 38.7% (135/349) of the E. coli isolates, respectively. Relative risk analysis of non-susceptibility to piperacillin/tazobactam across isolates from the three study sites revealed a highly significant association for OXA-1 (P < 0.001), whereas no significant associations were observed for TEM-1 (P = 0.424) or the combination of OXA-1 and TEM-1 (P = 0.082). When analyzed by institution, the relative risk of non-susceptibility to piperacillin/tazobactam remained highly significant for OXA-1 at TAMC and MAMC (P < 0.001 for both) but was not significant at BAMC (P = 0.21). OXA-1 and TEM-1-positive variants showed a significant association with genes conferring resistance to other antibiotics. ConclusionsThe OXA-1 gene plays a key role in resistance to piperacillin/tazobactam in ESBL-producing organisms, with geographic differences in non-susceptibility observed. Genetic profiling and localized data are crucial for optimizing antibiotic therapy and improving treatment outcomes.

microbiology↗

Protocol Optimization Improves the Performance of Multiplexed RNA Imaging

Spatial transcriptomics has emerged as a powerful tool to define the cellular structure of diverse tissues. One such method is multiplexed error robust fluorescence in situ hybridization (MERFISH). MERFISH identifies RNAs with error tolerant optical barcodes generated through sequential rounds of single-molecule fluorescence in situ hybridization (smFISH). MERFISH performance depends on a variety of protocol choices, yet their effect on performance has yet to be systematically examined. Here we explore a variety of properties to identify optimal choices for probe design, hybridization, buffer storage, and buffer composition. In each case, we introduce protocol modifications that can improve performance, and we show that, collectively, these modified protocols can improve MERFISH quality in both cell culture and tissue samples. As RNA FISH-based methods are used in many different contexts, we anticipate that the optimization experiments we present here may provide empirical design guidance for a broad range of methods.

genomics↗

Deviant functional connectivity patterns in the EEG and their potential use for dyslexia screening

Developmental dyslexia (DD) is a common learning disorder with potential neural origins. While EEG-based brain activation measures combined with machine learning have shown promise for DD screening, these approaches often lack validation on independent participants, which is a crucial step for practical application. This study developed an EEG-based screening approach and investigated the neural correlates of DD in Chinese children. EEG signals were recorded from 130 children (82 with DD, 48 typically developing) aged betweeen 7 and 11 during resting-state and working memory tasks. The EEG data were preprocessed into clean segments to compute functional connectivity (FC) matrices across four frequency bands (delta, theta, alpha, beta). The segments were split into two independent samples, ensuring independence at the participant level: Sample 1, used for training and five-fold cross validation of the convolutional neural networks, and Sample 2, used for cross-sample validation with the trained model. The beta-band FC index in the eyes-open condition achieved the highest within-sample classification accuracy (98%) and cross-sample accuracy (70%, p < .001). Discriminative FC patterns revealed that children with DD exhibited reduced temporal-parietal and central connectivity but increased frontal-central connectivity, likely reflecting compensatory mechanisms. Within the DD group, stronger FCs showed significant negative correlations with Chinese word reading accuracy and fluency. These findings suggest that EEG-based FC measures can effectively distinguish DD and reveal neural markers associated with impaired reading performance. This approach shows promise for noninvasive screening and deeper insight into the neural basis of DD, particularly in non-alphabetic language systems.

neuroscience↗

Repeated LPS induces training and tolerance of microglial responses across brain regions

BackgroundNeuroinflammation is involved in the pathogenesis of almost every central nervous system disorder. As the brains innate immune cells, microglia fine tune their activity to a dynamic brain environment. Previous studies have shown that repeated bouts of peripheral inflammation can trigger long-term changes in microglial gene expression and function, a form of innate immune memory. Methods and ResultsIn this study, we used multiple low-dose lipopolysaccharide (LPS) injections in adult mice to study the acute cytokine, transcriptomic, and microglia morphological changes that contribute to the formation of immune memory in the frontal cortex, hippocampus, and striatum, as well as the long-term effects of these changes on behavior. Training and tolerance of gene expression was shared across regions, and we identified 3 unique clusters of DEGs (2xLPS-sensitive, 4xLPS-sensitive, LPS-decreased) with different biological functions. 2xLPS-sensitive DEG promoters were enriched for binding sites for IRF and NFkB family transcription factors, two key regulators of innate immune memory. We quantified shifts in microglia morphological populations and found that while the proportion of ramified and rod-like microglia mostly remained consistent within brain regions and sexes with LPS treatment, there was a shift from ameboid towards hypertrophic morphological states across immune memory states and a dynamic emergence and resolution of trains of rod-like microglia with repeated LPS. ConclusionsTogether, findings support the dynamic regulation of microglia during the formation of immune memories in the brain and support future work to exploit this model in brain disease contexts.

neuroscience↗

Spatially resolved single-cell analysis uncovers protein kinase C-& expressing microglia with anti-tumor activity in glioblastoma

Glioblastoma (GBM) is a brain tumor that poses a formidable challenge to treatment options available. The tumor microenvironment (TME) in GBM is highly complex, marked by immunosuppression and cellular heterogeneity. Understanding the cellular interactions and their spatial organization within the TME is crucial for developing effective therapeutic strategies. In this study, we integrated single-cell RNA sequencing and spatial transcriptomics in a GBM mouse model to unravel the spatial landscape of the brain TME. We identified a previously unrecognized microglia subtype expressing protein kinase C{delta} (PKC{delta}) associated with potent anti-tumor functions. The presence of PKC{delta}-expressing microglia was confirmed in resected human GBM specimens. Elevating tumoral PKC{delta} expression using niacin or adeno-associated virus in mice enhanced the phagocytosis of GBM cells by microglia in culture and increased the lifespan of mice with intracranial GBM. These findings were corroborated in analyses of the TCGA GBM datasets where low PKC{delta} samples showed negative pathway enrichment for apoptosis, phagocytosis, and immune signaling pathways, as well as lower levels of immune cell infiltration overall. Our study underscores the importance of integrating spatial context to unravel the TME, resulting in the identification of previously unrecognized subsets of microglia with anti-tumor functions. These findings provide valuable insights for advancing innovative immunotherapeutic strategies in GBM.

immunology↗

Streamlining remote nanopore data access with slow5curl

As adoption of nanopore sequencing technology continues to advance, the need to maintain large volumes of raw current signal data for reanalysis with updated algorithms is a growing challenge. Here we introduce slow5curl, a software package designed to streamline nanopore data sharing, accessibility and reanalysis. Slow5curl allows a user to fetch a specified read or group of reads from a raw nanopore dataset stored on a remote server, such as a public data repository, without downloading the entire file. Slow5curl uses an index to quickly fetch specific reads from a large dataset in SLOW5/BLOW5 format and highly parallelised data access requests to maximise download speeds. Using all public nanopore data from the Human Pangenome Reference Consortium (>22 TB), we demonstrate how slow5curl can be used to quickly fetch and reanalyse signal reads corresponding to a set of target genes from each individual in large cohort dataset (n = 91), minimising the time, egress costs, and local storage requirements for their reanalysis. We provide slow5curl as a free, open-source package that will reduce frictions in data sharing for the nanopore community: https://github.com/BonsonW/slow5curl

bioinformatics↗

Dopamine D1 and NMDA receptor co-regulation of protein translation in cultured nucleus accumbens neurons

Protein translation is essential for some forms of synaptic plasticity. We used nucleus accumbens (NAc) medium spiny neurons (MSN), co-cultured with cortical neurons to restore excitatory synapses, to examine whether dopamine modulates protein translation in NAc MSN. FUNCAT was used to measure translation in MSNs under basal conditions and after disinhibiting excitatory transmission using the GABAA receptor antagonist bicuculline (2 hr). Under basal conditions, translation was not altered by the D1-class receptor (D1R) agonist SKF81297 or the D2-class receptor (D2R) agonist quinpirole. Bicuculline alone robustly increased translation. This was reversed by quinpirole but not SKF81297. It was also reversed by co-incubation with the D1R antagonist SCH23390, but not the D2R antagonist eticlopride, suggesting dopaminergic tone at D1Rs. This was surprising because no dopamine neurons are present. An alternative explanation is that bicuculline activates translation by increasing glutamate tone at NMDA receptors (NMDAR) within D1R/NMDAR heteromers, which have been described in other cell types. Supporting this, immunocytochemistry and proximity ligation assays revealed D1/NMDAR heteromers on NAc cells both in vitro and in vivo. Further, bicucullines effect was reversed to the same extent by SCH23390 alone, the NMDAR antagonist APV alone, or SCH23390+APV. These results suggest that: 1) excitatory synaptic transmission stimulates translation in NAc MSNs, 2) this is opposed when glutamate activates D1R/NMDAR heteromers, even in the absence of dopamine, and 3) antagonist occupation of D1Rs within the heteromers prevents their activation. Our study is the first to suggest a role for D2 receptors and D1R/NMDAR heteromers in regulating protein translation.

neuroscience↗

Integrative Multiomics to Dissect the Lung Transcriptional Landscape of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) remains an incurable and often fatal disease despite currently available therapies. Multiomics systems biology analysis can shed new light on PAH pathobiology and inform translational research efforts. Using RNA sequencing on the largest PAH lung biobank to date (96 disease and 52 control), we aim to identify gene co-expression network modules associated with PAH and potential therapeutic targets. Co-expression network analysis was performed to identify modules of co-expressed genes which were then assessed for and prioritized by importance in PAH, regulatory role, and therapeutic potential via integration with clinicopathologic data, human genome-wide association studies (GWAS) of PAH, lung Bayesian regulatory networks, single-cell RNA-sequencing data, and pharmacotranscriptomic profiles. We identified a co-expression module of 266 genes, called the pink module, which may be a response to the underlying disease process to counteract disease progression in PAH. This module was associated not only with PAH severity such as increased PVR and intimal thickness, but also with compensated PAH such as lower number of hospitalizations, WHO functional class and NT-proBNP. GWAS integration demonstrated the pink module is enriched for PAH-associated genetic variation in multiple cohorts. Regulatory network analysis revealed that BMPR2 regulates the main target of FDA-approved riociguat, GUCY1A2, in the pink module. Analysis of pathway enrichment and pink hub genes (i.e. ANTXR1 and SFRP4) suggests the pink module inhibits Wnt signaling and epithelial-mesenchymal transition. Cell type deconvolution showed the pink module correlates with higher vascular cell fractions (i.e. myofibroblasts). A pharmacotranscriptomic screen discovered ubiquitin-specific peptidases (USPs) as potential therapeutic targets to mimic the pink module signature. Our multiomics integrative study uncovered a novel gene subnetwork associated with clinicopathologic severity, genetic risk, specific vascular cell types, and new therapeutic targets in PAH. Future studies are warranted to investigate the role and therapeutic potential of the pink module and targeting USPs in PAH.

genomics↗

A Tm4sf1-Marked Subpopulation of Endothelial Stem/Progenitor Cells Identified by Lung Single-Cell Omics of Pulmonary Arterial Hypertension

RationaleThe identification and role of endothelial progenitor cells (EPCs) in pulmonary arterial hypertension (PAH) remains controversial. Single-cell omics analysis can shed light on EPCs and their potential contribution to PAH pathobiology. ObjectivesWe aim to identify EPCs in rat lungs and assess their relevance to preclinical and human PAH. MethodsDifferential expression, gene set enrichment, cell-cell communication, and trajectory reconstruction analyses were performed on lung endothelial cells from single-cell RNA-seq of Sugen-hypoxia, monocrotaline, and control rats. Relevance to human PAH was assessed in multiple independent blood and lung transcriptomic datasets. Measurements and Main ResultsA subpopulation of endothelial cells (EA2) marked by Tm4sf1, a gene strongly implicated in cancer, harbored a distinct transcriptomic signature including Bmpr2 downregulation that was enriched for pathways such as inflammation and angiogenesis. Cell-to-cell communication networks specific to EA2 were activated in PAH such as CXCL12 signaling. Trajectory analysis demonstrated EA2 has a stem/progenitor cell phenotype. Analysis of independent datasets revealed Tm4sf1 is a marker for hematopoietic stem cells and is upregulated in PAH peripheral blood, particularly in patients with worse WHO functional class. EA2 signature genes including Procr and Sulf1 were found to be differentially regulated in the lungs of PAH patients and in PAH models in vitro, such as BMPR2 knockdown. ConclusionsOur study uncovered a novel Tm4sf1-marked stem/progenitor subpopulation of rat lung endothelial cells and demonstrated its relevance to preclinical and human PAH. Future experimental studies are warranted to further elucidate the pathogenic role and therapeutic potential of targeting EA2 and Tm4sf1 in PAH.

genomics↗

Improved Transcriptome Assembly Using a Hybrid of Long and Short Reads with StringTie

Short-read RNA sequencing and long-read RNA sequencing each have their strengths and weaknesses for transcriptome assembly. While short reads are highly accurate, they are unable to span multiple exons. Long-read technology can capture full-length transcripts, but its high error rate often leads to mis-identified splice sites, and its low throughput makes quantification difficult. Here we present a new release of StringTie that performs hybrid-read assembly. By taking advantage of the strengths of both long and short reads, hybrid-read assembly with StringTie is more accurate than long-read only or short-read only assembly, and on some datasets it can more than double the number of correctly assembled transcripts, while obtaining substantially higher precision than the long-read data assembly alone. Here we demonstrate the improved accuracy on simulated data and real data from Arabidopsis thaliana, Mus musculus, and human. We also show that hybrid-read assembly is more accurate than correcting long reads prior to assembly while also being substantially faster. StringTie is freely available as open source software at https://github.com/gpertea/stringtie.

bioinformatics↗

Detecting and phasing minor single-nucleotide variants from long-read sequencing data

Cellular genetic heterogeneity is common in many biological conditions including cancer, microbiome, co-infection of multiple pathogens. Detecting and phasing minor variants, which is to determine whether multiple variants are from the same haplotype, play an instrumental role in deciphering cellular genetic heterogeneity, but are still difficult because of technological limitations. Recently, long-read sequencing technologies, including those by Pacific Biosciences and Oxford Nanopore, have provided an unprecedented opportunity to tackle these challenges. However, high error rates make it difficult to take full advantage of these technologies. To fill this gap, we introduce iGDA, an open-source tool that can accurately detect and phase minor single-nucleotide variants (SNVs), whose frequencies are as low as 0.2%, from raw long-read sequencing data. We also demonstrated that iGDA can accurately reconstruct haplotypes in closely-related strains of the same species (divergence[&ge;] 0.011%) from long-read metagenomic data. Our approach, therefore, presents a significant advance towards the complete deciphering of cellular genetic heterogeneity.

bioinformatics↗

Generation of clonal male and female mice through CRISPR/Cas9-mediated Y chromosome deletion in embryonic stem cells

Mice derived entirely from embryonic stem (ES) cells can be generated in one step through tetraploid complementation. Although XY male ES cell lines are commonly used in this system, occasionally, monosomic XO female all-ES mice are produced through spontaneous Y chromosome loss. Here, we describe an efficient method to obtain monosomic XO ES cells by CRISPR/Cas9-mediated deletion of the Y chromosome allowing generation of clonal male and female mice by tetraploid complementation. The monosomic XO female mice are viable and are able to produce normal male and female offspring. Direct generation of clonal male and female mice from the same mutant ES cells significantly accelerates the production of complex genetically modified mouse models by circumventing multiple rounds of outbreeding.Competing Interest StatementThe authors have declared no competing interest.View Full Text

developmental biology↗

JNK pathway restricts DENV, ZIKV and CHIKV infection by activating complement and apoptosis in mosquito salivary glands

Arbovirus infection of Aedes aegypti salivary glands (SGs) determines transmission. However, there is a dearth of knowledge on SG immunity. Here, we characterized SG immune response to dengue, Zika and chikungunya viruses using high-throughput transcriptomics. The three viruses regulate components of Toll, IMD and JNK pathways. However, silencing of Toll and IMD components showed variable effects on SG infection by each virus. In contrast, regulation of JNK pathway produced consistent responses. Virus infection increased with depletion of component Kayak and decreased with depletion of negative regulator Puckered. Virus-induced JNK pathway regulates complement and apoptosis in SGs via TEP20 and Dronc, respectively. Individual and co-silencing of these genes demonstrate their antiviral effects and that both may function together. Co-silencing either TEP20 or Dronc with Puckered annihilates JNK pathway antiviral effect. We identified and characterized the broad antiviral function of JNK pathway in SGs, expanding the immune arsenal that blocks arbovirus transmission.

microbiology↗

Molecular assays to detect the presence and viability of Phytophthora ramorum and Grosmannia clavigera

Abstract/KeywordsTo determine if living microorganisms of phytosanitary concern are present in wood after eradication treatment and to evaluate the efficacy of such treatments, the method of choice is to grow microbes in petri dishes for subsequent identification. However, some plant pathogens are difficult or impossible to grow in axenic cultures. A molecular methodology capable of detecting living fungi and fungus-like organisms in situ can provide a solution. RNA represents the transcription of genes and can therefore only be produced by living organisms, providing a proxy for viability. We designed and used RNA-based molecular diagnostic assays targeting genes essential to vital processes and assessed their presence in wood colonized by fungi and oomycetes through reverse transcription and real-time polymerase chain reaction (PCR). A stability analysis was conducted by comparing the ratio of mRNA to gDNA over time following heat treatment of wood infected with the Oomycete Phytophthora ramorum and the fungus Grosmannia clavigera. The real-time PCR results indicated that the DNA remained stable over a period of 10 days post treatment in heat-treated wood samples, whereas mRNA could not be detected after 24 hours for P. ramorum or 96 hours for G. clavigera. Therefore, this method provides a reliable way to evaluate the viability of these pathogens and test the effectiveness of existing and emerging wood treatments. This can have important phytosanitary impacts on assessing both timber and non-timber forest products of commercial value in international wood trade.

microbiology↗

A unified web platform for network-based analyses of genomic data

Functional genomics networks are widely used to identify unexpected pathway relationships in large genomic datasets. However, it is challenging to quantitatively compare the signal-to-noise ratio of different networks, the biology they describe, and to identify the optimal network to interpret a particular genetic dataset. Via GeNets users can train a machine-learning model (Quack) to make such comparisons; and they can execute, store, and share analyses of genetic and RNA sequencing datasets.

genomics↗