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Taylor, S.

Publications and source records attributed to Taylor, S..

At least 55 records · Page 3Linked to original sources

LanceOtron: a deep learning peak caller for ATAC-seq, ChIP-seq, and DNase-seq

ATAC-seq, ChIP-seq, and DNase-seq have revolutionized molecular biology by allowing researchers to identify important DNA-encoded elements genome-wide. Regions where these elements are found appear as peaks in the analog signal of an assays coverage track, and despite the ease with which humans can visually categorize these regions, meaningful peak calls from whole genome datasets require complex analytical techniques. Current methods focus on statistical tests to classify peaks, reducing the information-dense peak shapes to simply maximum height, and discounting that background signals do not completely follow any known probability distribution for significance testing. Deep learning has been shown to be highly accurate for image recognition, on par or exceeding human ability, providing an opportunity to reimagine and improve peak calling. We present the peak calling framework LanceOtron, which combines multifaceted enrichment measurements with deep learning image recognition techniques for assessing peak shape. In benchmarking transcription factor binding, chromatin modification, and open chromatin datasets, LanceOtron outperforms the long-standing, gold-standard peak caller MACS2 through its improved selectivity and near perfect sensitivity. In addition to command line accessibility, a graphical web application was designed to give any researcher the ability to generate optimal peak calls and interactive visualizations in a single step.

bioinformatics↗

Endogenous Retroviral Elements Generate Pathologic Neutrophils and Elastase Rich Exosomes in Pulmonary Arterial Hypertension

Neutrophil elastase (NE) is implicated in pulmonary arterial hypertension (PAH) but the role of neutrophils in the pathogenesis of PAH is unclear. Here we show that neutrophils from PAH vs. control subjects produce and release increased NE associated with enhanced extracellular trap formation. PAH neutrophils are highly adherent and show decreased migration consistent with increased vinculin, identified on proteomic analysis and previously linked to an antiviral response. This was substantiated by a transcriptomic interferon signature in PAH neutrophils and an increase in human endogenous retrovirus (HERV-K) envelope protein. NE and interferon genes are induced by HERV-K envelope and vinculin is increased by HERV-K dUTPase that is elevated in PAH plasma. Neutrophil exosomes from PAH plasma contain increased NE and HERV-K envelope and induce pulmonary hypertension in mice, that is mitigated by the NE inhibitor and antiviral agent, elafin. Thus, elevated HERVs explain pathological neutrophils linked to PAH induction and progression.

immunology↗

Multi-omic profiling reveals widespread dysregulation of innate immunity and hematopoiesis in COVID-19

Our understanding of protective vs. pathologic immune responses to SARS-CoV-2, the virus that causes Coronavirus disease 2019 (COVID-19), is limited by inadequate profiling of patients at the extremes of the disease severity spectrum. Here, we performed multi-omic single-cell immune profiling of 64 COVID-19 patients across the full range of disease severity, from outpatients with mild disease to fatal cases. Our transcriptomic, epigenomic, and proteomic analyses reveal widespread dysfunction of peripheral innate immunity in severe and fatal COVID-19, with the most profound disturbances including a prominent neutrophil hyperactivation signature and monocytes with anti-inflammatory features. We further demonstrate that emergency myelopoiesis is a prominent feature of fatal COVID-19. Collectively, our results reveal disease severity-associated immune phenotypes in COVID-19 and identify pathogenesis-associated pathways that are potential targets for therapeutic intervention. One Sentence SummarySingle-cell profiling demonstrates multifarious dysregulation of innate immune phenotype associated with COVID-19 severity.

immunology↗

PARG inhibition induces replication catastrophe in ovarian cancer cells with down-regulated DNA replication genes

The discovery that PARP1/2 inhibitors selectively kill BRCA mutant cells has led to a paradigm shift in the treatment of women with homologous recombination (HR)-deficient high-grade serous ovarian cancer (HGSOC), driving unprecedented improvements in progression-free and, more recently, overall survival. However, because most HGSOC cases are not HR-defective, and are therefore unlikely to benefit from PARPi-based therapies, additional strategies will be required to improve outcomes for women with HR-proficient disease. To develop novel therapeutic strategies, considerable attention is now being focused on inhibitors targeting PARG, the poly(ADP ribose) glycohydrolase that counterbalances PARP1/2 activity. Here we characterise ten ovarian cancer cell lines in response to the PARG inhibitor PDD00017273, hereafter PARGi. We demonstrate that six lines are resistant while four are sensitive, and that sensitivity correlates with several markers of persistent DNA replication stress, DNA damage and replication catastrophe, namely the accumulation of asymmetric DNA replication fibres, {gamma}H2AX and RPA foci, KAP1 and Chk1 phosphorylation, a pre-mitotic cell cycle block and, following prolonged exposure, a pan-nuclear {gamma}H2AX phenotype that indicates RPA exhaustion. We demonstrate that PARGi-sensitive cell lines have down-regulated DNA replication genes, including components of the fork protection complex, namely TIMELESS, TIPIN and CLASPIN. These observations suggest that a subset of HGSOC may respond to PARG inhibitors and that "replication stress" gene expression signature could serve as a predictive biomarker to guide the design of clinical trials.

cancer biology↗

Multi-omic profiling of primary mouse neutrophils reveals a pattern of sex and age-related functional regulation

SummaryNeutrophils are the most abundant white blood cells in humans and constitute one of the first lines of defense in the innate immune response. Neutrophils are extremely short-lived cells, which survive less than a day after reaching terminal differentiation. Thus, little is known about how organismal aging, rather than the daily cellular aging process, may impact neutrophil biology. In addition, accumulating evidence suggests that both immunity and organismal aging are sex-dimorphic. Here, we describe a multi-omic resource of mouse primary bone marrow neutrophils from young and old female and male mice, at the transcriptomic, metabolomic and lipidomic levels. Importantly, we identify widespread age-related and sex-dimorphic regulation of ‘omics’ in neutrophils, specifically regulation of chromatin. Using machine-learning, we identify candidate molecular drivers of age-related and sex-dimorphic transcriptional regulation of neutrophils. We leverage our resource to predict increased levels/release of neutrophil elastase in male mice. To date, this dataset represents the largest multi-omics resource for the study of neutrophils across biological sex and ages. This resource identifies molecular states linked to neutrophil characteristics linked to organismal age or sex, which could be targeted to improve immune responses across individuals.Competing Interest StatementThe authors have declared no competing interest.View Full Text

genomics↗

Multi Locus View : An Extensible Web Based Tool for the Analysis of Genomic Data

MotivationTracking and understanding data quality, analysis and reproducibility are critical concerns in the biological sciences. This is especially true in genomics where Next Generation Sequencing (NGS) based technologies such as ChIP-seq, RNA-seq and ATAC-seq are generating a flood of genome-scale data. These data-types are extremely high level and complex with single experiments capable of mapping ten to hundreds of thousands of biologically meaningful events across the genome. However, such data are usually processed with automated tools and pipelines, generating tabular outputs and static visualizations. These are difficult to interact with and require substantial bioinformatic skills to manipulate and query. Similarly, interpretation is normally made at a high level without the ability to visualise the underlying data in detail and so the complexity and quality of the real underlying biological signal is lost. Also genomics datasets require integration with other genomics datasets to be properly interpreted and this integration with multiple tracks again requires substantial bioinformatics skills and is difficult to visualise across multiple pertinent datasets. Conventional genome browsers do allow for the detailed visualisation of multiple tracks but are limited to browsing single locations and do not allow for interactions with the dataset as a whole. MLV has been developed to allow users to fluidly interact with genomics datasets at multiple scales, from complete metadata labelled and clustered populations to detailed representations of individual elements. It has inbuilt tools to integrate signals across multiple datasets and to perform dimensionality reduction and clustering analysis based on the extracted signal, allowing for the high-level analysis of complex datasets while maintaining visualisation of the fine grain structure of the data. MLVs ability to visualise clustering within the data combined with efficient tools for large-scale tagging of individual elements makes it a unique tool for the generation of annotated datasets for modern machine learning approaches. ResultsMulti Locus View (MLV) is a web based tool for the visualisation, analysis and annotation of Next Generation Sequencing data sets. The user is able to browse the raw data, cluster, and combine the data with other analysis. Intuitive filtering and visualisation then enables the user to quickly locate and annotate regions of interest. User datasets can then be shared with other users or made public for quick assessment from the academic community. MLV is publically available at https://mlv.molbiol.ox.ac.uk and the source code is available at https://github.com/Hughes-Genome-Group/mlv

bioinformatics↗

Golgi-Dependent Copper Homeostasis Sustains Synaptic Development and Mitochondrial Content

Rare genetic diseases preponderantly affect the nervous system with phenotypes spanning from neurodegeneration to neurodevelopmental disorders. This is the case for both Menkes and Wilson disease, arising from mutations in ATP7A and ATP7B, respectively. The ATP7A and ATP7B proteins localize to the Golgi and regulate copper homeostasis. We demonstrate conserved interactions between ATP7 paralogs with the COG complex, a Golgi complex tether. Disruption of Drosophila copper homeostasis by ATP7 tissue-specific transgenic expression caused alterations in epidermis, catecholaminergic, sensory, and motor neurons. Prominent among neuronal phenotypes was a decreased mitochondrial content at synapses, a phenotype that paralleled with alterations of synaptic morphology, transmission, and plasticity. These neuronal and synaptic phenotypes caused by transgenic expression of ATP7 were rescued by downregulation or haploinsufficiency of COG complex subunits. We conclude that the integrity of Golgi-dependent copper homeostasis mechanisms, requiring ATP7 and COG, are necessary to maintain mitochondria functional integrity and localization to synapses. Significance StatementMenkes and Wilson disease affect copper homeostasis and characteristically afflict the nervous system. However, their molecular neuropathology mechanisms remain mostly unexplored. We demonstrate that copper homeostasis in neurons is maintained by two factors that localize to the Golgi apparatus, ATP7 and the COG complex. Disruption of these mechanisms affect mitochondrial function and localization to synapses as well as neurotransmission and synaptic plasticity. These findings suggest a new principle of interorganelle communication whereby the Golgi apparatus and mitochondria are functionally coupled through homeostatically controlled cellular copper levels.

neuroscience↗

CaptureCompendium: a comprehensive toolkit for 3C analysis.

DNA folding within nuclei is a highly ordered process, with implications for gene regulation and development. An array of chromosome conformation capture (3C) methods have been developed to investigate how DNA is packaged within nuclei and to interrogate specific interactions. While these methods use different approaches to examine target loci (many-versus-all) or the entire genome (all-versus-all), they all rely on the core principle of endonuclease digestion and proximity-based ligation to re-arrange genomic order to reflect the three-dimensional nuclear conformation. This sequence reorganization creates novel chimeric DNA fragments which require specialist bioinformatic tools to analyze and visualize. Despite this need for specialist bioinformatic skills, the core biological importance of genome folding has seen widespread methodological uptake. To service the needs of experimentalists using the many-versus-all Capture-C family of methods we have developed CaptureCompendium; a toolkit of software to simplify the design, analysis and presentation of 3C experiments.

bioinformatics↗

Type-1 IFN primed monocytes in pathogenesis of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is the most severe form of lung fibrosis. It is progressive, and has an extremely poor outcome and limited treatment options. The disease exclusively affects the lungs, and thus less attention has been focused on blood-borne immune cells. which could be a more effective therapeutic target than lung-based cells. Here, we questioned if circulating monocytes, which has been shown to be increased in IPF, bore abnormalities that might contribute to its pathogenesis. We found that levels of circulating monocytes correlated directly with the extent of fibrosis in the lungs, and increased further during acute clinical deterioration. Monocytes in IPF were phenotypically distinct, displaying increased expression of CD64, a type 1 IFN gene expression signature and a greater magnitude of type 1 IFN response when stimulated. These abnormalities were accompanied by markedly raised CSF-1 levels in the serum, prolonged survival of monocytes ex vivo, and increased numbers of monocytes in lung tissue. Our study defines the key monocytic abnormalities in IPF, proposing type 1 IFN-primed monocytes as a potential driver of an aberrant repair response and fibrosis. It provides a rationale for targeting monocytes and identifies monocytic CD64 as a potential specific therapeutic target for IPF.

immunology↗

Molecular Choreography of Acute Exercise

Exercise testing is routinely used in clinical practice to assess fitness - a strong predictor of survival - as well as causes of exercise limitations. While these studies often focus on cardiopulmonary response and selected molecular pathways, the dynamic system-wide molecular response to exercise has not been fully characterized. We performed a longitudinal multi-omic profiling of plasma and peripheral blood mononuclear cells including transcriptome, immunome, proteome, metabolome and lipidome in 36 well-characterized volunteers before and after a controlled bout of acute exercise (2, 15, 30 min and 1 hour in recovery). Integrative analysis revealed an orchestrated choreography of biological processes across key tissues. Most of these processes were dampened in insulin resistant participants. Finally, we discovered biological pathways involved in exercise capacity and developed prediction models revealing potential resting blood-based biomarkers of fitness.

systems biology↗

The in situ structure of Parkinson’s disease-linked LRRK2

Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most frequent cause of familial Parkinsons disease. LRRK2 is a multi-domain protein containing a kinase and GTPase. Using in situ cryo-electron tomography and subtomogram averaging, we reveal a 14-[A] structure of LRRK2 bearing a pathogenic mutation that oligomerizes as a right-handed double-helix around microtubules, which are left-handed. Using integrative modeling, we determine the architecture of LRRK2, showing that the GTPase points towards the microtubule, while the kinase is exposed to the cytoplasm. We identify two oligomerization interfaces mediated by non-catalytic domains. Mutation of one of these abolishes LRRK2 microtubule-association. Our work demonstrates the power of cryo-electron tomography to obtain structures of previously unsolved proteins in their cellular environment and provides insights into LRRK2 function and pathogenicity.

biophysics↗

An integrated platform to systematically identify causal variants and genes for polygenic human traits.

Genome-wide association studies (GWAS) have identified over 150,000 links between common genetic variants and human traits or complex diseases. Over 80% of these associations map to polymorphisms in non-coding DNA. Therefore, the challenge is to identify disease-causing variants, the genes they affect, and the cells in which these effects occur. We have developed a platform using ATAC-seq, DNaseI footprints, NG Capture-C and machine learning to address this challenge. Applying this approach to red blood cell traits identifies a significant proportion of known causative variants and their effector genes, which we show can be validated by direct in vivo modelling.

genetics↗

Is asthma associated with exposure to smoke from a coal mine fire?

In 2014, a fire at the Hazelwood open cut coal mine (Victoria, Australia) burned for about 6 weeks. Residents of the adjacent town of Morwell were exposed to high levels of fine particulate matter (PM2.5) during this period. Three and a half years after the event, this study aimed to investigate the long-term impact of short-term exposure to coal mine fire smoke on asthma.\n\nA cross-sectional analysis was undertaken on a group of exposed participants with asthma from Morwell (n=165) and a group of unexposed participants with asthma from the control town of Sale (n=64). Town exposure status was determined by modelled PM2.5 data for the mine fire period. Respiratory symptoms were assessed with a validated respiratory health questionnaire and symptom severity score. Asthma control was assessed with an asthma control questionnaire. Lung function testing included spirometry, bronchodilator response, and fraction of exhaled nitric oxide.\n\nThere was no evidence that exposed Morwell participants had more severe asthma symptoms, worse lung function, or more eosinophilic airway inflammation compared to unexposed Sale participants. However there was some evidence that Morwell participants had more uncontrolled than well-controlled asthma, compared to the participants from Sale (adjusted relative risk ratio 2.71 95%CI: 1.02, 7.21, p=0.046).\n\nThree and a half years after exposure, coal mine fire smoke does not appear to be associated with more severe asthma symptoms or worse lung function, but may be associated with poorer asthma control.\n\nSummary take home messageIn people with asthma, short-term coal mine fire smoke exposure does not appear to have long-term impact on severity of asthma symptoms, lung function or eosinophilic airway inflammation, but may affect asthma control.

epidemiology↗

Thermodynamic Measures of Human Brain Development from Fetal Stage to Adulthood

This paper analyzes the data obtained from tissue samples of the human brains containing protein expression values. The data have been processed for their thermodynamic measure in terms of the Gibbs free energy of the corresponding protein-protein interaction networks. We have investigated the functional dependence of the Gibbs free energies on age and found consistent trends for most of the 16 main brain areas. The peak of the Gibbs energy values is found at birth with a trend toward plateauing at the age of maturity. We have also compared the data for males and females and uncovered functional differences for some of the brain regions. Author SummaryIn this paper we briefly outline the theoretical basis for a novel analysis of brain development in terms of a thermodynamic measure (Gibbs free energy) for the corresponding protein-protein interaction networks. We analyzed the overall developmental patterns for Gibbs free energy as a function of age across all brain regions. Of particular note was the significant upward trend in the fetal stages, which is generally followed by a sharp dip at birth and a plateau at maturity. We then compared the trends for female and male samples. A crossover pattern was observed for most of the brain regions, where the Gibbs free energy of the male samples were lower than the female samples at prenatal and neonatal ages, but higher at ages 8-40 finally converging at late adulthood.

neuroscience↗

CSynth: A Dynamic Modelling and Visualisation Tool for 3D Chromatin Structure

The 3D structure of chromatin in the nucleus is important for gene expression and regulation. Chromosomal conformation capture techniques, such as Hi-C, generate large amounts of data showing interaction points on the genome but these are hard to interpret using standard tools. We have developed CSynth, a high performance 3D genome browser and real time chromatin restraint-based modeller to visualise dynamic and interactive models of chromatin capture data. CSynth does its calculations in the GPU hence is much faster than existing modelling software to infer and visualise the chromatin structure which also allow real-time interaction with the modelling parameters. It also allows straightforward comparison of interaction data and the results of third party 3D modelling outputs. In addition we include an option to view and manipulate these complicated structures using Virtual Reality (VR) allowing scientists to immerse themselves in the models for further understanding. This VR component has also proven to be a valuable teaching and public engagement tool. CSynth is web based and available to use at http://csynth.org.

bioinformatics↗

Reconstruction of the global neural crest gene regulatory network in vivo

Precise control of developmental processes is encoded in the genome in the form of gene regulatory networks (GRNs). Such multi-factorial systems are difficult to decode in vertebrates owing to their complex gene hierarchies and transient dynamic molecular interactions. Here we present a genome-wide in vivo reconstruction of the GRN underlying development of neural crest (NC), an emblematic embryonic multipotent cell population. By coupling NC-specific epigenomic and single-cell transcriptome profiling with genome/epigenome engineering in vivo, we identify multiple regulatory layers governing NC ontogeny, including NC-specific enhancers and super-enhancers, novel trans-factors and cis-signatures. Assembling the NC regulome has allowed the comprehensive reverse engineering of the NC-GRN at unprecedented resolution. Furthermore, identification and dissection of divergent upstream combinatorial regulatory codes has afforded new insights into opposing gene circuits that define canonical and neural NC fates. Our integrated approach, allowing dissection of cell-type-specific regulatory circuits in vivo, has broad implications for GRN discovery and investigation.

developmental biology↗

Structures of the PKA RIα holoenzyme with the FLHCC driver J-PKAcα or wild type PKAcα

Fibrolamellar hepatocellular carcinoma (FLHCC) is driven by J-PKAc, a kinase fusion chimera of the J-domain of DnaJB1 with PKAc, the catalytic subunit of Protein Kinase A (PKA). Here we report the crystal structures of the chimeric fusion RI2:J-PKAc2 holoenzyme formed by J-PKAc and the PKA regulatory (R) subunit RI, and the wild type (wt) RI2:PKAc2 holoenzyme. The chimeric and wt RI holoenzymes have quaternary structures different from the previously solved wt RI{beta} and RII{beta} holoenzymes. The chimeric holoenzyme shows an isoform-specific interface dominated by antiparallel interactions between the N3A-N3A motifs of RI that serves as an anchor for RI structural rearrangements during cAMP activation. The wt RI holoenzyme showed the same configuration as well as a distinct second conformation. In the structure of the chimeric fusion RI2:J-PKAc2 holoenzyme, the presence of the J-domain does not prevent formation of the holoenzymes, and is positioned away from the symmetrical interface between the two RI:J-PKAc heterodimers in the holoenzyme. The J-domains have significantly higher temperature factors than the rest of the holoenzyme, implying a large degree of conformational flexibility. Furthermore molecular dynamics simulations were applied to analyze the conformational states of chimeric fusion and wt RI holoenzymes, and showed an ensemble of conformations in the majority of which the J-domain was dynamic and rotated away from the R:J-PKAc interface. Thus, rather than affecting the interactions with the regulatory subunits, the fusion of the J-domain to the PKAc alters the conformational landscape of the chimeric fusion holoenzymes and potentially, as result, the interactions with other molecules. The structural and dynamic features of these holoenzymes enhance our understanding of the fusion chimera protein J-PKAc that drives FLHCC as well as the isoform specificity of PKA.

biochemistry↗

Neural distinctiveness declines with age in auditory cortex and is associated with auditory GABA levels.

Neural activation patterns in the ventral visual cortex in response to different categories of visual stimuli (e.g., faces vs. houses) are less selective, or distinctive, in older adults than in younger adults, a phenomenon known as age-related neural dedifferentiation. Previous work in animals suggests that age-related reductions of the inhibitory neurotransmitter, gamma aminobutyric acid (GABA), may play a role in this age-related decline in neural distinctiveness. In this study, we investigated whether neural dedifferentiation extends to auditory cortex and whether individual differences in GABA are associated with individual differences in neural distinctiveness in humans. 20 healthy young adults (ages 18-29) and 23 healthy older adults (over 65) completed a functional magnetic resonance imaging (fMRI) scan, during which neural activity was estimated while they listened to foreign speech and music. GABA levels in the auditory, ventrovisual and sensorimotor cortex were estimated in the same individuals in a separate magnetic resonance spectroscopy (MRS) scan. Relative to the younger adults, the older adults exhibited both (1) less distinct activation patterns for music vs. speech stimuli and (2) lower GABA levels in the auditory cortex. Also, individual differences in auditory GABA levels (but not ventrovisual or sensorimotor GABA levels) predicted individual differences in neural distinctiveness in the auditory cortex in the older adults. These results demonstrate that age-related neural dedifferentiation extends to the auditory cortex and suggest that declining GABA levels may play a role in neural dedifferentiation in older adults.\n\nSignificance StatementPrior work has revealed age-related neural dedifferentiation in the visual cortex. GABA levels also decline with age in several parts of the human cortex. Here, we report that these two age-related changes are linked; neural dedifferentiation is associated with lower GABA levels in older adults. We also show that age-related neural dedifferentiation extends to auditory cortex, suggesting that it may be a general feature of the aging brain. These findings provide novel insights into the neurochemical basis of age-related neural dedifferentiation in humans and also offer a potential new avenue for investigating age-related declines in central auditory processing.

neuroscience↗