Biology subjects

Yang, H.

Publications and source records attributed to Yang, H..

At least 667 records · Page 37Linked to original sources

bioRxiv2018

Multi-Center Study of Resectable Lung Lesions by Ultra-Deep Sequencing of Targeted Genes in Plasma Cell-Free DNA to Assess Nodule Malignancy and Detect Lung Cancers

BACKGROUNDEarly detection of lung cancer to allow curative treatment remains challenging. Cell-free circulating tumor DNA (ctDNA) analysis may aid in malignancy assessment and early cancer diagnosis of lung nodules found in screening imagery.\n\nMETHODSThe multi-center clinical study enrolled 192 patients with operable occupying lung diseases. Plasma ctDNA, white blood cell genomic DNA (gDNA) and tumor tissue gDNA of each patient were analyzed by ultra-deep sequencing to an average of 35,000X of the coding regions of 65 lung cancer-related genes.\n\nRESULTSThe cohort consists of a quarter of benign lung diseases and three quarters of cancer patients with all histopathology subtypes. 64% of the cancer patients is at Stage I. Gene mutations detection in tissue gDNA and plasma ctDNA results in a sensitivity of 91% and specificity of 88%. When ctDNA assay was used as the test, the sensitivity was 69% and specificity 96%. As for the lung cancer patients, the assay detected 63%, 83%, 94% and 100%, for Stage I, II, III and IV, respectively. In a linear discriminant analysis, combination of ctDNA, patient age and a panel of serum biomarkers boosted the overall sensitivity to 80% at a specificity of 99%. 29 out of the 65 genes harbored mutations in the lung cancer patients with the largest number found in TP53 (30% plasma and 62% tumor tissue samples) and EGFR (20% and 40%, respectively).\n\nCONCLUSIONPlasma ctDNA was analyzed in lung nodule assessment and early cancer detection while an algorithm combining clinical information enhanced the test performance.

clinical trials↗

bioRxiv2018

Genetic population variation and phylogeny of Sinomenium acutum (Menispermaceae) in subtropical China through chloroplast marker

Sinomenium acutum (Menispermaceae) is a traditional Chinese medicine. In recent years, extensive harvesting for medicinal purposes has resulted in a sharp decline in its population. Genetic information is crucial for the proper exploitation and conservation of Sinomenium acutum, but little is known about it at present. In this study, we analyzed 77 samples from 4 populations using four non-coding regions (atpI-atpH, trnQ-5rps16, trnH-psbA, and trnL-trnF) of chloroplast DNA and 14 haplotypes (from C1 to C14) were identified. C1 and C3 were common haplotypes, which were shared by all populations, and C3 was an ancestral haplotype, the rest were rare haplotypes. Obvious phylogeographic structure was not existed inferred by GST / NST test. Mismatch distribution, Tajimas D and Fus FS tests failed to support a rapid demographic expansion in Sinomenium acutum. AMOVA highlighted that the high level of genetic differentiation within population. Low genetic variation among populations illustrated gene flow was not restricted. Genetic diversity analyses demonstrated that the populations of Xuefeng, Dalou, and Daba Mountains were possible refugia localities of Sinomenium acutum. Based on this study, we proposed a preliminary protection strategy for it that C1, C3, C11 and C12 must be collected. These results offer an valuable and useful information for this species of population genetic study as well as further conservation.

molecular biology↗

bioRxiv2018

The mitochondrial DNA content can not predict the embryo viability

ObjectiveTo investigate whether the mitochondrial DNA content could predict the embryo viability\n\nDesignRetrospective analysis.\n\nSettingReproductive genetics laboratory\n\nPatient(s)A total of 421 biopsied samples obtained from 129 patients\n\nIntervention(s)Embryo biopsies samples underwent whole genome amplification (WGA) and were tested by next generation sequencing (NGS) and array Comparative Genomic Hybridization (aCGH), 30 samples were selected randomly to undergo quantitative real-time polymerase chain reaction (qPCR).\n\nMain Outcome Measure(s)Those embryos which obtained the consistent chromosome status determined both aCGH and NGS platform were further classified. We investigated the relationship of mtDNA content with several factors including female patient age, embryo morphology, chromosome status, and live birth rate of both blastocysts and blastomeres.\n\nResult(s)A total of 386 (110 blastomeres and 276 blastocysts) out of 399 embryos showed consistent chromosome status outcome. We found no statistically difference was observed in aneuploid and euploid blastocysts (p=0.14), the same phenomenon was observed in aneuploid and euploid blastomeres (p=0.89). Similarly, the mtDNA content was independent of female patient age, embryo morphology and live birth rate.\n\nConclusion(s)The mtDNA content did not provide a reliable prediction of the viability of blastocysts to initiate a pregnancy.

ecology↗

bioRxiv2018

Bacterial strain displacement in inflammatory bowel diseases after fecal microbiota transplantation

Fecal microbiota transplantation (FMT), which is thought to have the potential to correct dysbiosis of gut microbiota, has recently been used to treat inflammatory bowel disease (IBD). To elucidate the extent and principles of microbiota engraftment in IBD patients after FMT treatment, we conducted an interventional prospective cohort study. The cohort included two categories of patients: (1) patients with moderate to severe Crohns disease (CD) (Harvey-Bradshaw Index [≥] 7, n = 11, and (2) patients with ulcerative colitis (UC) (Montreal classification, S2 and S3, n = 4). All patients were treated with a single FMT (via mid-gut, from healthy donors) and follow-up visits were performed at baseline, 3 days, one week, and one month after FMT (missing time points included). At each follow-up time point, fecal samples of the participants were collected along with their clinical metadata. For comparative analysis, 10 fecal samples from 10 healthy people were included to represent the diversity level of normal gut microbiota. Additionally, the metagenomic data of 25 fecal samples from 5 individuals with metabolic syndrome who underwent autologous FMT treatment were downloaded from a previous published paper to represent natural microbiota shifts during FMT. All fecal samples underwent shotgun metagenomic sequencing. We found that 3 days after FMT, 11 out of 15 recipients were in remission (3 out of 4 UC recipients; 8 out of 11 CD recipients). Generally, bacterial colonization was observed to be lower in CD recipients than in UC recipients at both species and strain levels. Furthermore, across species, different strains displayed disease-specific displacement advantages under two-disease status. Finally, most post-FMT species (> 80%) could be properly predicted (AUC > 85%) using a random forest classification model, with the gut microbiota composition and clinical parameters of pre-FMT recipients acting as the most contributive factors for prediction accuracy.

clinical trials↗

bioRxiv2018

Ultra-high throughput multiplexing and sequencing of >500 bp amplicon regions on the Illumina HiSeq 2500 platform

Amplification, sequencing and analysis of the 16S rRNA gene affords characterization of microbial community composition. As this tool has become more popular and amplicon-sequencing applications have grown in the total number of samples, growth in sample multiplexing is becoming necessary while maintaining high sequence quality and sequencing depth. Here, modifications to the Illumina HiSeq 2500 platform are described which produce greater multiplexing capabilities and 300 bp paired-end reads of higher quality than produced by the current Illumina MiSeq platform. To improve the feasibility and flexibility of this method, a 2-Step PCR amplification protocol is also described that allows for targeting of different amplicon regions, thus improving amplification success from low bacterial bioburden samples.\n\nImportanceAmplicon sequencing has become a popular and widespread tool for surveying microbial communities. Lower overall costs associated with high throughput sequencing have made it a widely-adopted approach, especially for projects which necessitate sample multiplexing to eliminate batch effect and reduced time to acquire data. The method for amplicon sequencing on the Illumina HiSeq 2500 platform described here provides improved multiplexing capabilities while simultaneously producing greater quality sequence data and lower per sample cost relative to the Illumina MiSeq platform, without sacrificing amplicon length. To make this method more flexible to various amplicon targeted regions as well as improve amplification from low biomass samples, we also present and validate a 2-Step PCR library preparation method.

microbiology↗

bioRxiv2018

Skepticism toward adaptive signals in DNA sequence comparisons - Is the neutral theory dead yet?

A recent study suggests that the evidence of adaptive DNA sequence evolution accumulated in the last 20 years may be suspect1. The suspicion thus calls for a re-examination of the reported evidence. The two main lines of evidence are from the McDonald-Kreitman (MK) test, which compares divergence and polymorphism data, and the PAML test, which analyzes multi-species divergence data. Here, we apply these two tests concurrently on the genomic data of Drosophila and Arabidopsis. To our surprise, the >100 genes identified by the two tests do not overlap beyond random expectations. The results could mean i) high false positives by either test or ii) high false-negatives by both tests due to low powers. To rule out the latter, we merge every 20 - 30 genes into a "supergene". At the supergene level, the power of detection is high, with 8% - 56% yielding adaptive signals. Nevertheless, the calls still do not overlap. Since it is unlikely that one test is largely correct and the other is mostly wrong (see Discussion), the total evidence of adaptive DNA sequence evolution should be deemed unreliable. As suggested by Chen et al.1, the reported evidence for positive selection may in fact be signals of fluctuating negative selection, which are handled differently by the two tests. Possible paths forward on this central evolutionary issue are discussed.

evolutionary biology↗

bioRxiv2018

Diagnostic Whole Exome Sequencing in Patients with Short Stature

Short stature is among the most common reasons for children being referred to the pediatric endocrinology clinics. The cause of short stature is broad, in which genetic factors play a substantial role, especially in primary growth disorders. However, identifying the molecular causes for short stature remains as a challenge because of the high heterogeneity of the phenotypes. Here, whole exome sequencing (WES) was used to identify the genetic causes of short stature with unknown etiology for 20 patients aged from 1 to 16 years old. The genetic causes of short stature were identified in 9 of the 20 patients, corresponding to a molecular diagnostic rate of 45%. Notably, in 2 of the 9 patients identified with genetic causes, the diagnosed diseases based on WES are different from the original clinical diagnosis. Our results highlight the clinical utility of WES in the diagnosis of rare, high heterogeneity disorders.

genetics↗

bioRxiv2018

NUCOME: A Comprehensive Database of Nucleosome Organizations in Mammalian Genomes

Nucleosome organization is involved in many regulatory activities in various organisms. However, studies integrating nucleosome organizations in mammalian genomes are very limited mainly due to the lack of comprehensive data management. Here, we present NUCOME, which is the first database to organize publicly available MNase-seq data resource and manage unified processed datasets covering various cell types in human and mouse. The NUCOME provides standard, qualified and informative nucleosome organization data at the genome scale and at any genomic regions for users downstream analyses. NUCOME is freely available at http://compbio.tongji.edu.cn/NUCOME/.

bioinformatics↗

bioRxiv2018

Integrated Analysis Revealed Hub Genes in Breast Cancer

The aim of this study was to identify the hub genes in breast cancer and provide further insight into the tumorigenesis and development of breast cancer. To explore the hub genes in breast cancer, we performed an integrated bioinformatics analysis. Two gene expression profiles were downloaded from the GEO database. The differentially expressed genes (DEGs) were identified by using the \"limma\" package. Then, we performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis to explore the functional annotation and potential pathways of the DEGs. Next, protein-protein interaction (PPI) network analysis and weighted gene coexpression network analysis (WGCNA) were conducted to screen for hub genes. To confirm the reliability of the identified hub genes, we obtained TCGA-BRCA data by using WGCNA to screen for genes that were strongly related to breast cancer. By combining the results from the GEO and TCGA datasets, we finally identified 15 real hub genes in breast cancer. Finally, we performed an overall survival analysis to explore the connection between the expression of hub genes and the overall survival time of breast cancer patients. We found that for all hub genes, higher expression was associated with significantly shorter overall survival times among breast cancer patients.

bioinformatics↗

bioRxiv2018

New genetic variants associated with major adverse cardiovascular events in patients with acute coronary syndromes and treated with clopidogrel and aspirin

ImportanceAlthough a few studies have reported the effects of several polymorphisms on major adverse cardiovascular events (MACE) in patients with acute coronary syndromes (ACS) and those undergoing percutaneous coronary intervention (PCI), these genotypes account for only a small fraction of the variation and evidence is insufficient. This study aims to identify new genetic variants associated with MACE by large-scale sequencing data.\n\nObjectiveTo identify the genetic variants that caused MACE.\n\nDesignAll patients in this study were allocated to dual antiplatelet therapy for up to 12 months and have the follow-up duration of 18 months.\n\nSettingA two-stage association study was performed.\n\nParticipantsWe evaluated the associations of genetic variants and MACE in 1961 patients with ACS undergoing PCI (2009-2012), including high-depth whole exome sequencing of 168 patients in the discovery cohort and high-depth targeted sequencing of 1793 patients in the replication cohort.\n\nMain Outcomes and MeasureThe primary clinical efficacy endpoint was the major adverse cardiovascular events (MACE) composite endpoint, including cardiovascular death, myocardial infarction (MI), stroke (CT or MR scan confirmed) and repeated revascularization (RR).\n\nResultsWe discovered and confirmed six new genotypes associated with MACE in patients with ACS. Of which, rs17064642 at MYOM2 increased the risk of MACE (hazard ratio [HR] 2.76; P = 2.95 x 10-9) and reached genome-wide significance. The other five suggestive variants were KRTAP10-4 (rs201441480), WDR24 (rs11640115), ECHS1 (rs140410716), AGAP3 (rs75750968) and NECAB1 (rs74569896). Notably, the expressions of MYOM2 and ECHS1 are down-regulated in both animal models and patients with phenotypes related to MACE. Importantly, we developed the first superior classifier for predicting MACE and achieved high predictive accuracy (0.809).\n\nConclusions and RelevanceWe identified six new genotypes associated with MACE and developed a superior classifier for predicting MACE. Our findings shed light on the pathogenesis of cardiovascular outcomes and may help clinician to make decision on the therapeutic intervention for ACS patients.\n\nTrial RegistrationThis study has been registered in the Chinese Clinical Trial Registry (http://www.chictr.org.cn, Registration number: ChiCTR-OCH-11001198).

genetics↗

bioRxiv2018

What can facial mechanoreceptors tell the mouse brain about whisking?

Haptic perception synthesizes touch with proprioception, or sense of body position. Humans and mice alike experience rich active touch of the face. Because most facial muscles lack proprioceptor endings, the sensory basis of facial proprioception remains unsolved. Facial proprioception may instead rely on mechanoreceptors that encode both touch and self-motion. In rodents, whisker mechanoreceptors provide a signal that informs the brain about whisker position. Whisking involves coordinated orofacial movements, so mechanoreceptors innervating facial regions other than whiskers could also provide information about whisking. To define all sources of sensory information about whisking available to the brain, we recorded spikes from mechanoreceptors innervating diverse parts of the face. Whisker motion was encoded best by whisker mechanoreceptors, but also by those innervating whisker pad hairy skin and supraorbital vibrissae. Redundant self-motion responses may provide the brain with a stable proprioceptive signal despite mechanical perturbations such as whisker growth and active touch.

neuroscience↗

bioRxiv2018

Sequencing of the MHC region defines HLA-DQA1 as the major independent risk for anti-citrullinated protein antibodies (ACPA)-positive rheumatoid arthritis in Han population

The strong genetic contribution of the major histocompatibility complex (MHC) to rheumatoid arthritis (RA) susceptibility has been generally attributed to HLA-DRB1. However, due to the high linkage disequilibrium in the MHC region, it is difficult to define the real or/and additional independent genetic risks using the conventional HLA genotyping or chip-based microarray technology. By the capture sequencing of entire MHC region for discovery and HLA-typing for validation in 2,773 subjects of Han ancestry, we identified HLA-DQ1:160D as the strongest independent genetic risk for anti-citrullinated protein antibodies (ACPA)-positive RA in Han population (P = 6.16 x 10-36, OR=2.29). Further stepwise conditional analysis revealed that DR{beta}1:37N has an independent protective effect on ACPA-positive RA (P = 5.81 x 10-16, OR=0.49). The DQ1:160 coding allele DQA1*0303 displayed high impact on joint radiographic severity, especially in patients with early disease and smoking (P = 3.02 x 10-5). Interaction analysis by comparative molecular modeling revealed that the negative charge of DQ1:160D stabilizes the dimer of dimers, leading to an increased T cell activation. The electrostatic potential surface analysis indicated that the negative charged DR{beta}1:37N encoding alleles could bind with epitope P9 arginine, thus may result in a decreased RA susceptibility.\n\nIn this study, we provide the first evidence that HLA-DQA1, instead of HLA-DRB1, is the strongest and independent genetic risk for ACPA-positive RA in Chinese Han population. Our study also illustrates the value of MHC deep sequencing for fine mapping disease risk variants in the MHC region.

genetics↗

bioRxiv2018

PIRD: Pan immune repertoire database

MotivationT and B cell receptors (TCRs and BCRs) play a pivotal role in the adaptive immune system by recognizing an enormous variety of external and internal antigens. Understanding these receptors is critical for exploring the process of immunoreaction and exploiting potential applications in immunotherapy and antibody drug design. Although a large number of samples have had their TCR and BCR repertoires sequenced using high-throughput sequencing in recent years, very few databases have been constructed to store these kinds of data. To resolve this issue, we developed a database.\n\nResultsWe developed a database, the Pan Immune Repertoire Database (PIRD), located in China National GeneBank (CNGBdb), to collect and store annotated TCR and BCR sequencing data, including from Homo sapiens and other species. In addition to data storage, PIRD also provides functions of data visualisation and interactive online analysis. Additionally, a manually curated database of TCRs and BCRs targeting known antigens (TBAdb) was also deposited in PIRD.\n\nAvailability and ImplementationPIRD can be freely accessed at https://db.cngb.org/pird.

immunology↗

bioRxiv2018

MetaPGN: a pipeline for construction and graphical visualization of annotated pangenome networks

Pangenome analyses facilitate the interpretation of genetic diversity and evolutionary history of a taxon. However, there is an urgent and unmet need to develop new tools for advanced pangenome construction and visualization, especially for metagenomic data. Here we present an integrated pipeline, named MetaPGN, for construction and graphical visualization of pangenome network from either microbial genomes or metagenomes. Given either isolated genomes or metagenomic assemblies coupled with a reference genome of the targeted taxon, MetaPGN generates a pangenome in a topological network, consisting of genes (nodes) and gene-gene genomic adjacencies (edges) of which biological information can be easily updated and retrieved. MetaPGN also includes a self-developed Cytoscape plugin for layout of and interaction with the resulting pangenome network, providing an intuitive and interactive interface for full exploration of genetic diversity. We demonstrate the utility of MetaPGN by constructing Escherichia coli (E. coli) pangenome networks from five E. coli pathogenic strains and 760 human gut microbiomes respectively, revealing extensive genetic diversity of E. coli within both isolates and gut microbial populations. With the ability to extract and visualize gene contents and gene-gene physical adjacencies of a specific taxon from large-scale metagenomic data, MetaPGN provides advantages in expanding pangenome analysis to uncultured microbial taxa. MetaPGN is available at https://github.com/peng-ye/MetaPGN.

genomics↗

bioRxiv2018

Single-cell RNA-seq reveals dynamic transcriptome profiling in human early neural differentiation

BackgroundInvestigating cell fate decision and subpopulation specification in the context of the neural lineage is fundamental to understanding neurogenesis and neurodegenerative diseases. The differentiation process of neural-tube-like rosettes in vitro is representative of neural tube structures, which are composed of radially organized, columnar epithelial cells and give rise to functional neural cells. However, the underlying regulatory network of cell fate commitment during early neural differentiation remains elusive.\n\nResultsIn this study, we investigated the genome-wide transcriptome profile of single cells from six consecutive reprogramming and neural differentiation time points and identified cellular subpopulations present at each differentiation stage. Based on the inferred reconstructed trajectory and the characteristics of subpopulations contributing the most towards commitment to the central nervous system (CNS) lineage at each stage during differentiation, we identified putative novel transcription factors in regulating neural differentiation. In addition, we dissected the dynamics of chromatin accessibility at the neural differentiation stages and revealed active c/s-regulatory elements for transcription factors known to have a key role in neural differentiation as well as for those that we suggest are also involved. Further, communication network analysis demonstrated that cellular interactions most frequently occurred among embryoid body (EB) stage and each cell subpopulation possessed a distinctive spectrum of ligands and receptors associated with neural differentiation which could reflect the identity of each subpopulation.\n\nConclusionsOur study provides a comprehensive and integrative study of the transcriptomics and epigenetics of human early neural differentiation, which paves the way for a deeper understanding of the regulatory mechanisms driving the differentiation of the neural lineage.

developmental biology↗

bioRxiv2018

Single-cell RNA-seq reveals distinct dynamic behavior of sex chromosomes during early human embryogenesis

AbstractO_ST_ABSBackgroundC_ST_ABSSeveral animal and human studies have demonstrated that sex affects kinetics and metabolism during early embryo development. However, the mechanism governing these differences at the molecular level is unknown, warranting a systematic profiling of gene expression in males and females during embryogenesis.\n\nFindingsWe performed comprehensive analyses of gene expression comparing male and female embryos using available single-cell RNA-sequencing data of 1607 individual cells from 99 human preimplantation embryos, covering development stages from 4-cell to late blastocyst (E2 to E7). Consistent chromosome-wide transcription of autosomes was observed, while sex chromosomes showed significant differences after embryonic genome activation (EGA). Differentially expressed genes (DE genes) in male and female embryos mainly involved in the cell cycle, protein translation and metabolism. The Y chromosome was initially activated by pioneer genes, RPS4Y1 and DDX3Y, while the two X chromosomes in female were widely activated after EGA. Expression of X-linked genes in female significantly declined at the late blastocyst stage, especially in trophectoderm cells, revealing a rapid process of dosage compensation.\n\nConclusionsWe observed imbalanced expression from sex chromosomes in male and female embryos during EGA, with dosage compensation occurring first in female trophectoderm cells. Studying the effect of sex differences during human embryogenesis, as well as understanding the mechanism of X chromosome inactivation and its correlation with early miscarriage, will provide a basis for advancing assisted reproductive technology (ART) and thereby improve the treatment of infertility and possibly enhance reproductive health.

developmental biology↗

bioRxiv2018

Using SMOG 2 to simulate complex biomolecular assemblies

Over the last 20 years, the application of structure-based (G[o]-like) models has ranged from protein folding with coarse-grained models to all-atom representations of large-scale molecular assemblies. While there are many variants that may be employed, the common feature of these models is that some (or all) of the stabilizing energetic interactions are defined based on knowledge of a particular experimentally-obtained conformation. With the generality of this approach, there was a need for a versatile computational platform for designing and implementing this class of models. To this end, the SMOG 2 software package provides an easy-to-use interface, where the user has full control of the model parameters. This software allows the user to edit XML-formatted files in order to provide definitions of new structure-based models. SMOG 2 reads these \"template\" files and maps the interactions onto specific structures, which are provided in PDB format. The force field files produced by SMOG 2 may then be used to perform simulations with a variety of popular molecular dynamics suites. In this chapter, we describe some of the key features of the SMOG 2 package, while providing examples and strategies for applying these techniques to complex (often large-scale) molecular assemblies, such as the ribosome.

biophysics↗

bioRxiv2018

Comprehensive analysis of immune evasion in breast cancer by single-cell RNA-seq

The tumor microenvironment is composed of numerous cell types, including tumor, immune and stromal cells. Cancer cells interact with the tumor microenvironment to suppress anticancer immunity. In this study, we molecularly dissected the tumor microenvironment of breast cancer by single-cell RNA-seq. We profiled the breast cancer tumor microenvironment by analyzing the single-cell transcriptomes of 52,163 cells from the tumor tissues of 15 breast cancer patients. The tumor cells and immune cells from individual patients were analyzed simultaneously at the single-cell level. This study explores the diversity of the cell types in the tumor microenvironment and provides information on the mechanisms of escape from clearance by immune cells in breast cancer.\n\nOne Sentence SummaryLandscape of tumor cells and immune cells in breast cancer by single cell RNA-seq

cancer biology↗