Biology subjects

Yang, W.

Publications and source records attributed to Yang, W..

At least 325 records · Page 18Linked to original sources

bioRxiv2020

RIPK2 Stabilizes c-Myc and is an Actionable Target for Inhibiting Prostate Cancer Metastasis

Despite advances in diagnosis and treatment, metastatic prostate cancer remains incurable and is associated with high mortality rates. Thus, novel actionable drug targets are urgently needed for therapeutic interventions in advanced prostate cancer. Here we report receptor-interacting protein kinase 2 (RIPK2) as an actionable drug target for suppressing prostate cancer metastasis. RIPK2 is frequently amplified in lethal prostate cancers and its overexpression is associated with disease progression and aggressiveness. Genetic and pharmacological inhibition of RIPK2 significantly suppressed prostate cancer progression in vitro and metastasis in vivo. Multi-level proteomic analysis revealed that RIPK2 strongly regulates c-Myc protein stability and activity, largely by activating the MKK7/JNK/c-Myc phosphorylation pathway--a novel, non-canonical RIPK2 signaling pathway. Targeting RIPK2 inhibits this phosphorylation pathway, and thus promotes the degradation of c-Myc--a potent oncoprotein for which no drugs have been approved for clinical use yet. These results support targeting RIPK2 for personalized therapy in prostate cancer patients towards improving survival.

cancer biology↗

bioRxiv2020

Snipe: Highly sensitive pathogen detection from metagenomic sequencing data

Metagenomics data provides rich information for the detection of foodborne pathogens from food and environmental samples that are mixed with complex background bacteria strains. While pathogen detection from metagenomic sequencing data has become an activity of increasing interest, shotgun sequencing of uncultured food samples typically produces data that contains reads from many different organisms, making accurate strain typing a challenging task. Particularly, as many pathogens may contain a common set of genes that are highly similar to those from normal bacteria in food samples, traditional strain-level abundance profiling approaches do not perform well at detecting pathogens of very low abundance levels. To overcome this limitation, we propose an abundance correction method based on species-specific genomic regions to achieve high sensitivity and high specificity in target pathogen detection at low abundance.

microbiology↗

bioRxiv2020

Submodular sketches of single-cell RNA-seq measurements

Analyzing and sharing massive single-cell RNA-seq data sets can be facilitated by creating a "sketch" of the data--a selected subset of cells that accurately represent the full data set. Using an existing benchmark, we demonstrate the utility of submodular optimization in efficiently creating high quality sketches of scRNA-seq data.

bioinformatics↗

bioRxiv2020

Circuit mechanisms underlying chronic epilepsy in a mouse model of focal cortical malformation

HighlightsO_LIEctopic interlaminar excitatory inputs from infragranular layers to layer 2/3 pyramidal neurons is a key component of the hyperexcitable circuitry C_LIO_LIDisrupted E/I balance was located far away from cortical malformations C_LIO_LIDendritic inhibition from somatostatin interneurons play a key role in epileptogenesis C_LIO_LIClosed-loop optogenetic stimulation to activate remainder somatostatin interneurons irreversibly stops the spontaneous spike-wave discharges in vivo. C_LI In BriefYang et al. report abnormal synaptic reorganization in an epileptogenesis zone in a mouse model of cortical malformation. The authors further demonstrate that spontaneous spike-wave discharges can be curbed by selectively activating somatostatin interneurons using close-loop fiber optogenetic stimulation to a small cortical region away from the microgyrus. SummaryHow aberrant neural circuits contribute to chronic epilepsy remains unclear. Using a mouse model of focal cortical malformation with spontaneous seizures, we dissected the circuit mechanisms underlying epileptogenesis. Spontaneous and optogenetically induced hyperexcitable bursts in vivo were present in a cortical region distal to (> 1mm) freeze-lesion induced microgyrus, instead of a region near it. ChR2-assisted circuit mapping revealed ectopic interlaminar excitatory inputs from infragranular layers to layer 2/3 pyramidal neurons as a key component of the hyperexcitable circuitry. This disrupted balance between excitation and inhibition was prominent in the cortical region distal to the microgyrus. Consistently, the synapses of both parvalbumin-positive interneurons (PV) and somatostatin-positive interneurons (SOM) to pyramidal neurons were maladaptive in a layer- and site-specific fashion. Finally, closed-loop optogenetic stimulation of SOM, but not PV, terminated spontaneous spike-wave discharges. Together, these results demonstrate highly site- and cell-type specific synaptic reorganization underlying chronic cortical epilepsy and provide insights into potential treatment strategies for this devastating neurological disorder.

neuroscience↗

bioRxiv2020

Ratio of the interferon-γ signature to the immunosuppression signature predicts anti-PD-1 therapy response in melanoma

Immune checkpoint inhibitor (ICI) treatments produce clinical benefit in many patients. However, better pretreatment predictive biomarkers for ICI are still needed to help match individual patients to the treatment most likely to be of benefit. Existing gene expression profiling (GEP)-based biomarkers for ICI are primarily focused on measuring a T cell-inflamed tumour microenvironment that contributes positively to the response to ICI. Here, we identified an immunosuppression signature (IMS) through analysing RNA sequencing data from a combined discovery cohort (n = 120) consisting of three publicly available melanoma datasets. Using the ratio of an established IFN-{gamma} signature and IMS led to consistently better prediction of the ICI therapy outcome compared to a collection of nine published GEP signatures from the literature on a newly generated internal validation cohort (n = 55) and three published datasets of metastatic melanoma treated with anti-PD-1 (n = 48) and anti-CTLA-4 (n = 42) as well as in patients with gastric cancer treated with antiPD-1 (n = 45), demonstrating the potential utility of IMS as a predictive/prognostic biomarker that complements existing GEP signatures for immunotherapy.

immunology↗

bioRxiv2020

Humanized Single Domain Antibodies Neutralize SARS-CoV-2 by Targeting Spike Receptor Binding Domain

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread across more than 200 countries and regions, leading to an unprecedented medical burden and live lost. SARS-CoV-2 specific antivirals or prophylactic vaccines are not available. Neutralizing antibodies provide efficient blockade for viral infection and are a promising category of biological therapies. Using SARS-CoV-2 spike RBD as a bait, we have discovered a panel of humanized single domain antibodies (sdAbs). These sdAbs revealed binding kinetics with the equilibrium dissociation constant (KD) of 0.7~33 nM. The monomeric sdAbs showed half maximal inhibitory concentration (IC50) of 0.003~0.3 g/mL in pseudotyped particle neutralization assay, and 0.23~0.50 g/mL in authentic SARS-CoV-2 neutralization assay. Competitive ligand-binding data suggested that the sdAbs either completely blocked or significantly inhibited the association between SARS-CoV-2 RBD and viral entry receptor ACE2. Finally, we showed that fusion of the human IgG1 Fc to sdAbs improved their neutralization activity by tens of times. These results reveal the novel SARS-CoV-2 RBD targeting sdAbs and pave a road for antibody drug development.

microbiology↗

bioRxiv2020

A general model to explain repeated turnovers of sex determination in the Salicaceae

Dioecy, the presence of separate sexes on distinct individuals, has evolved repeatedly in multiple plant lineages. However, the specific mechanisms through which sex systems evolve and their commonalities among plant species remain poorly understood. With both XY and ZW sex systems, the family Salicaceae provides a system to uncover the evolutionary forces driving sex chromosome turnovers. In this study, we performed a genome-wide association study to characterize sex determination in two Populus species, P. euphratica and P. alba. Our results reveal an XY system of sex determination on chromosome 14 of P. euphratica, and a ZW system on chromosome 19 of P. alba. We further assembled the corresponding sex determination regions, and found that their sex chromosome turnovers may be driven by the repeated translocations of a Helitron-like transposon. During the translocation, this factor may have captured partial or intact sequences that are orthologous to a type-A cytokinin response regulator gene. Based on results from this and other recently published studies, we hypothesize that this gene may act as a master regulator of sex determination for the entire family. We propose a general model to explain how the XY and ZW sex systems in this family can be determined by the same RR gene. Our study provides new insights into the diversification of incipient sex chromosome in flowering plants by showing how transposition and rearrangement of a single gene can control sex in both XY and ZW systems.

genomics↗

bioRxiv2020

Identification of 38 novel loci for systemic lupus erythematosus and genetic heterogeneity that may underly population disparities in this disease

Systemic lupus erythematosus (SLE), a worldwide autoimmune disease with high heritability, shows differences in prevalence, severity and age of onset among different ancestral groups. Previous genetic studies have focused more on European populations, which appear to be the least affected. Consequently, the genetic variations that underly the commonalities, differences and treatment options in SLE among ancestral groups have not been well elucidated. To address this, we undertook a genome-wide association study, increasing the sample size of Chinese populations to the level of existing European studies. Thirty-eight novel SLE-associated loci and incomplete sharing of genetic architecture were identified. Nine disease loci showed clear ancestral group heterogeneity and implicated antibody production as a potential mechanism for differences in disease manifestation. Polygenic risk scores performed significantly better when trained on matched ancestral data sets. These analyses help to reveal the genetic bases for disparities in SLE among ancestral groups.

genetics↗

bioRxiv2020

DAISM-DNN: Highly accurate cell type proportion estimation with in silico data augmentation and deep neural networks

Understanding the immune cell abundance of cancer and other disease-related tissues has an important role in guiding disease treatments. Computational cell type proportion estimation methods have been previously developed to derive such information from bulk RNA sequencing (RNA-seq) data. Unfortunately, our results show that the performance of these methods can be seriously plagued by the mismatch between training data and real-world data. To tackle this issue, we propose the DAISM-DNNXMBD1 pipeline that trains a deep neural network (DNN) with dataset-specific training data populated from a small number of calibrated samples using DAISM, a novel Data Augmentation method with an In Silico Mixing strategy. The evaluation results demonstrate that the DAISM-DNN pipeline outperforms other existing methods consistently and substantially for all the cell types under evaluation on real-world datasets.

bioinformatics↗

bioRxiv2020

Engineered chemotaxis core signaling units indicate a constrained kinase-off state

Bacterial chemoreceptors, the CheA histidine kinase, and the coupling protein CheW comprise transmembrane molecular arrays with remarkable sensing properties. An unanswered question concerns how receptors turn off CheA kinase activity. Chemoreceptor cytoplasmic regions engineered to assume a trimer-of-receptor-dimers configuration form well-defined complexes with CheA and CheW and promote a kinase-off state. These mimics of core signaling units were assembled to homogeneity and investigated by site-directed spin-labeling with pulse-dipolar ESR spectroscopy (PDS), small-angle x-ray scattering, targeted protein cross-linking, and cryo-electron microscopy. The kinase-off state is especially stable, has relatively low domain mobility and associates the histidine substrate domain P1 and docking domain P2 with the kinase core. Distances measured between spin-labeled ADP molecules bound to the P4 kinase domain provide evidence for a "dipped conformation" that has been previously proposed from molecular dynamics simulations. Taken together, the data provide an experimentally restrained model for the inhibited state of the core-signaling unit and suggest that chemoreceptors indirectly sequester the kinase and substrate domains to limit histidine autophosphorylation.

biochemistry↗

bioRxiv2020

Spirochetes produce ordered chemoreceptor arrays of unusual composition, arrangement, and symmetry to compensate for a highly curved membrane

Abstract/SummaryThe prokaryotic chemotaxis system is arguably the best-understood signaling pathway in biology, but most insights have been obtained from only a few model organisms and many studies have relied on artificial systems that alter membrane curvature1-3. In all previously described species, chemoreceptors organize with the histidine kinase (CheA) and coupling protein (CheW) into a hexagonal (P6 symmetry) extended array that is considered universal among archaea and bacteria4,5. Here, for the first time, we report an alternative symmetry (P2) of the chemotaxis apparatus that emerges from a strict linear organization of CheA in Treponema denticola cells, which possesses arrays with the highest native curvature investigated thus far. Using cryo-ET, we reveal that the Td chemoreceptor arrays assume a truly unusual arrangement of the supra-molecular protein assembly that has likely evolved to accommodate the high membrane curvature. The arrays have several additional atypical features, such as an extended dimerization domain of CheA and a variant CheW-CheR-like fusion protein that is critical for maintaining an ordered chemosensory apparatus in an extremely curved cell. Furthermore, the previously characterized Td oxygen sensor ODP influences array integrity and its loss substantially orders CheA. These results suggest a greater diversity of the chemotaxis signaling system than previously thought and demonstrate the importance of examining transmembrane systems in vivo to retain native membrane curvature.

microbiology↗

bioRxiv2020

Non-coding germline GATA3 variants alter chromatin topology and contribute to pathogenesis of acute lymphoblastic leukemia

Inherited non-coding genetic variants confer significant disease susceptibility in many cancers. However, the molecular processes of by which germline variants contribute to somatic lesions are poorly understood. We performed targeted sequencing in 5,008 patients and identified a key regulatory germline variant in GATA3 strongly associated with Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL). By creating an isogenic cellular model with CRISPR-Cas9 system, we showed that this variant activated a strong enhancer that significantly upregulated GATA3 transcription, which in turn reshaped the global chromatin accessibility and 3D genome organization. Remarkably, this genotype switch induced a chromatin loop between the CRLF2 oncogene and a distal enhancer, similar to the somatically acquired super-enhancer hijacking event in patients. GATA3 genotype-related alterations in transcriptional control and 3D chromatin organization were further validated in Ph-like ALL patients. Finally, we showed that GATA3 directly regulates CRLF2 and potentiates the oncogenic effects of JAK-STAT signaling in leukemogenesis. Altogether, our results provide evidence for a novel mechanism by which a germline non-coding variant contributes to oncogene activation epigenetic regulation and 3D genome reprogramming.

cancer biology↗

bioRxiv2020

Polyploidization enhancing genetic recombination of the ancestral diploid genome in the evolution of hexaploid wheat

Allopolyploidy increases its evolutionary potential by fixing heterosis and the advantage of gene redundancy. Allelic combinations generated from genetic recombination potentially provide many variations to the selection pools for evolution. May there be any relationship between allopolyploidization and genetic recombination? To study the impact of polyploidy on genetic recombination, we selected wheat as a model and simulated its evolution pathway of allopolyploidy by developing synthetic hexaploid wheat. The change of homologous chromosome recombination were investigated on their diploid DD and tetraploid AABB genomes after their allohexaploidization, respectively. The genetic recombination of the ancestral diploid genome of Aegilops tauschii was enhanced significantly more than 2 folds after their hexaploidization. Hexaploidization enhancing genetic recombination of the ancestral diploid D genome was firstly reported to be a new way to increase evolutionary potential of wheat, which is beneficial for wheat to conquer their narrow origination of D genome, quickly spread and make it a major crop of the world. Finally, re-synthetizing hexaploid wheat using diverse Ae. tauschii species with tetraploid wheat can be considered as a pleiotropic strategy to speed adaptive evolution of bread wheat in breeding processes by increasing both gene allele types and genetic recombination variations.

evolutionary biology↗

bioRxiv2020

ScaleQC: A Scalable Lossy to Lossless Solution for NGS Sequencing Data Compression

MotivationPer-base quality values in NGS sequencing data take a significant portion of storage even after compression. Lossy compression technologies could further reduce the space used by quality values. However, in many applications lossless compression is still desired. Hence, sequencing data in multiple file formats have to be prepared for different applications. ResultsWe developed a scalable lossy to lossless compression solution for quality values named ScaleQC. ScaleQC is able to provide bit-stream level scalability. More specifically, the losslessly compressed bit-stream by ScaleQC can be further truncated to lower data rates without re-encoding. Despite its scalability, ScaleQC still achieves same or better compression performance at both lossless and lossy data rates compared to the state-of-the-art lossless or lossy compressors. AvailabilityScaleQC has been integrated with SAMtools as a special quality value encoding mode for CRAM. Its source codes can be obtained from our integrated SAMtools (https://github.com/xmuyulab/samtools) with dependency on integrated HTSlib (https://github.com/xmuyulab/htslib).

bioinformatics↗

bioRxiv2020

Comparison of High-Throughput Single-Cell RNA Sequencing Data Processing Pipelines

With the development of single-cell RNA sequencing (scRNA-seq) technology, it has become possible to perform large-scale transcript profiling for tens of thousands of cells in a single experiment. Many analysis pipelines have been developed for data generated from different high-throughput scRNA-seq platforms, bringing a new challenge to users to choose a proper workflow that is efficient, robust and reliable for a specific sequencing platform. Moreover, as the amount of public scRNA-seq data has increased rapidly, integrated analysis of scRNA-seq data from different sources has become increasingly popular. How-ever, it remains unclear whether such integrated analysis would be biased if the data were processed by different upstream pipelines. In this study, we encapsulated seven existing high-throughput scRNA-seq data processing pipelines with Nextflow, a general integrative workflow management framework, and evaluated their performances in terms of running time, computational resource consumption, and data processing consistency using nine public datasets generated from five different high-throughput scRNA-seq platforms. Our work provides a useful guideline for the selection of scRNA-seq data processing pipelines based on their performances on different real datasets. In addition, these guidelines can serve as a performance evaluation framework for future developments in high-throughput scRNA-seq data processing.

bioinformatics↗

bioRxiv2020

Pathway-guided deep neural network toward interpretable and predictive modeling of drug sensitivity

MotivationTo efficiently save cost and reduce risk in drug research and development, there is a pressing demand to develop in-silico methods to predict drug sensitivity to cancer cells. With the exponentially increasing number of multi-omics data derived from high-throughput techniques, machine learning-based methods have been applied to the prediction of drug sensitivities. However, these methods have drawbacks either in the interpretability of mechanism of drug action or limited performance in modeling drug sensitivity. ResultsIn this paper, we presented a pathway-guided deep neural network model, referred to as pathDNN, to predict the drug sensitivity to cancer cells. Biological pathways describe a group of molecules in a cell that collaborates to control various biological functions like cell proliferation and death, thereby abnormal function of pathways can result in disease. To make advantage of both the excellent predictive ability of deep neural network and the biological knowledge of pathways, we reshape the canonical DNN structure by incorporating a layer of pathway nodes and their connections to input gene nodes, which makes the DNN model more interpretable and predictive compared to canonical DNN. We have conducted extensive performance evaluations on multiple independent drug sensitivity data sets, and demonstrate that pathDNN significantly outperformed canonical DNN model and seven other classical regression models. Most importantly, we observed remarkable activity decreases of disease-related pathway nodes during forward propagation upon inputs of drug targets, which implicitly corresponds to the inhibition effect of disease-related pathways induced by drug treatment on cancer cells. Our empirical experiments show that pathDNN achieves pharmacological interpretability and predictive ability in modeling drug sensitivity to cancer cells. AvailabilityThe web server, as well as the processed data sets and source codes for reproducing our work, is available at http://pathdnn.denglab.org

bioinformatics↗

bioRxiv2020

Accumulation of an unprecedented 5'-deoxyadenos-4'-yl radical unmasks the kinetics of the radical-mediated C-C bond formation step in MoaA catalysis

Radical S-adenosyl-L-methionine (SAM) enzymes catalyze various free radical-mediated reactions. In these enzymes, the rate-determining SAM cleavage kinetically masks all the subsequent steps. Due to this kinetic masking, detailed mechanistic characterization of radical transformations catalyzed by these enzymes is very difficult. Here, we report a successful kinetic characterization of the radical C-C bond formation catalyzed by a MoaA radical SAM enzyme. MoaA catalyzes an unprecedented 3',8-cyclization of GTP into 3',8-cyclo-7,8-dihydro-GTP (3',8-cH2GTP) during the molybdenum cofactor (Moco) biosynthesis. Through a series of EPR and biochemical characterization, we found that MoaA accumulates a 5'-deoxyadenos-4'-yl radical (5'-dA-C4'*) under the turnover conditions, and forms (4'S)-5'-deoxyadenosine ((4'S)-5'-dA), which is a C-4' epimer of the naturally occurring (4'R)-5'-dA. Together with kinetic characterizations, these observations revealed the presence of a shunt pathway in which an on-pathway intermediate, GTP C-3' radical, abstracts H-4' atom from 5'-dA to transiently generate 5'-dA-C4'* that is subsequently reduced stereospecifically to yield (4'S)-5'-dA. Detailed kinetic characterization of the shunt and the main pathways provided the comprehensive view of MoaA kinetics, and determined the rate of the on-pathway 3',8-cyclization step as 2.7 {+/-} 0.7 s-1. Together with DFT calculations, this observation suggested that the 3',8-cyclization is accelerated by 6 [~] 9 orders of magnitude by MoaA. Potential contributions of the active-site amino acid residues, and their potential relationships with human Moco deficiency disease are discussed. This is the first determination of the magnitude of catalytic rate acceleration by a radical SAM enzyme, and provides the foundation for understanding how radical SAM enzymes achieve highly specific radical catalysis.

biochemistry↗

bioRxiv2020

EWS-FLI1 regulates and cooperates with core regulatory circuitry in Ewing sarcoma

Core regulatory circuitry (CRC)-dependent transcriptional network is critical for developmental tumors in children and young adults carrying few gene mutations. However, whether and how CRC contributes to transcription regulation in Ewing sarcoma is unknown. Here, we identify and functionally validate a CRC "trio" constituted by three transcription factors (TFs): KLF15, TCF4 and NKX2-2, in Ewing sarcoma cells. Epigenomic analyses demonstrate that EWS-FLI1, the primary fusion driver for this cancer, directly establishes super-enhancers of each of these three TFs to activate their transcription. In turn, KLF15, TCF4 and NKX2-2 co-bind to their own and each others super-enhancers and promoters, forming an inter-connected auto-regulatory loop. Functionally, CRC factors contribute significantly to cell proliferation of Ewing sarcoma both in vitro and in vivo, and are all overexpressed in this cancer. Mechanistically, CRC factors exhibit prominent capacity of co-regulating the epigenome in cooperation with EWS-FLI1, occupying 77.2% of promoters and 55.6% of enhancers genome-wide. Downstream, CRC TFs coordinately regulate gene expression networks in Ewing sarcoma, directly controlling important signaling pathways for cancer, such as lipid metabolism pathway, PI3K/AKT and MAPK signaling pathways. Together, molecular characterization of the oncogenic CRC model advances our understanding of the biology of Ewing sarcoma. Moreover, this study identifies CRC-downstream genes and signaling pathways, which may contain potential targets for therapeutic intervention for this malignancy.

cancer biology↗