Biology subjects

Zhao, F.

Publications and source records attributed to Zhao, F..

At least 91 records · Page 5Linked to original sources

bioRxiv2022

Large-scale benchmarking of circRNA detection tools reveals large differences in sensitivity but not in precision

The detection of circular RNA molecules (circRNAs) is typically based on short-read RNA sequencing data processed by computational detection tools. During the last decade, a plethora of such tools have been developed, but a systematic comparison with orthogonal validation is missing. Here, we set up a circRNA detection tool benchmarking study, in which 16 tools were used and detected over 315,000 unique circRNAs in three deeply sequenced human cell types. Next, 1,516 predicted circRNAs were empirically validated using three orthogonal methods. Generally, tool-specific precision values are high and similar (median of 98.8%, 96.3%, and 95.5% for qPCR, RNase R, and amplicon sequencing, respectively) whereas the sensitivity and number of predicted circRNAs (ranging from 1,372 to 58,032) are the most significant tool differentiators. Furthermore, we demonstrate the complementarity of tools through the increase in detection sensitivity by considering the union of highly-precise tool combinations while keeping the number of false discoveries low. Finally, based on the benchmarking results, recommendations are put forward for circRNA detection and validation.

genomics↗

bioRxiv2022

ExposomeX: Integrative Exposomic Platform Expediates Discovery of "Exposure-Biology-Disease" Nexus

Exposome has become the hotspot of next-generation health studies. To date, there is no available effective platform to standardize the analysis of exposomic data. In this study, we aim to propose one new framework of exposomic analysis and build up one novel integrated platform "ExposomeX" to expediate the discovery of the "Exposure-Biology-Disease" nexus. We have developed 13 standardized modules to accomplish six major functions including statistical learning (E-STAT), exposome database search (E-DB), mass spectrometry data processing (E-MS), meta-analysis (E-META), biological link via pathway integration and protein-protein interaction (E-BIO) and data visualization (E-VIZ). Using ExposomeX, we can effectively analyze the multiple-dimensional exposomics data and investigate the "Exposure-Biology-Disease" nexus by exploring mediation and interaction effects, understanding statistical and biological mechanisms, strengthening prediction performance, and automatically conducting meta-analysis based on well-established literature databases. The performance of ExposomeX has been well validated by re-analyzing two previous multi-omics studies. Additionally, ExposomeX can efficiently help discover new associations, as well as relevant in-depth biological pathways via protein-protein interaction and gene ontology network analysis. In sum, we have proposed a novel framework for standardized exposomic analysis, which can be accessed using both R and online interactive platform (http://www.exposomex.cn/).

bioinformatics↗

bioRxiv2022

Integrated Multi-omics Analyses of NFKB1 patients B cells points towards an up regula-tion of NF-κB network inhibitors

The transcription factor NF-{kappa}B plays a pivotal role in the adaptive immune response. Pathogenic variants in NFKB1 are the most common genetic etiology of common variable immunodeficiency (CVID). Patients frequently present with impaired terminal B cell differentiation, autoimmunity, and hyperinflammatory immune dysregulation. NF-{kappa}B signaling and target gene expression are expected to be dysregulated in NFKB1-mutated patients. Here, we performed a multi-omics characterization of B cells from a cohort of clinically affected and unaffected NFKB1 mutation carriers. Our analysis identified specific epigenetic dysregulation and gene expression differences on B cells from NFKB1-mutated patients. We observed an aberrant expression of negative regulators of NF-{kappa}B signaling in NFKB1 mutation carriers, which may be a key factor for the autoinflammatory phenotype of these patients. Moreover, our analysis points towards a dysregulation of XBP1 and BCL3, key players of B cell activation and proliferation at different stages of B cell differentiation. The reduced expression of negative regulators of the NF-{kappa}B network is likely to be one of several mechanisms responsible for the aberrant NF-{kappa}B signaling, which impairs the maintenance of a normal humoral immune response. In summary, our findings highlight epigenetic and gene expression changes in B cells associated with NFKB1 mutations. Our data give insight into future therapeutic opportunities for patients with NFKB1 (haplo)insufficiency.

immunology↗

bioRxiv2022

An exploratory study of a simple approach for evaluating drug solubility in milk related vehicles

Milk related materials are frequently used as a vehicle for drug product administration. Therefore, drug solubility information in milk related vehicles is desirable for prediction of how they may influence in vivo drug release and bioavailability. However, there are very limited data published on this topic. This study explored a practical method to address the key challenges associated with solubility assessment in milk, including the sample equilibration time and cleanup procedures. Amitriptyline, acetaminophen, dexamethasone, nifedipine, piroxicam, and prednisolone were selected as model drugs to represent a wide range of physicochemical properties. Their solubilities were determined at room temperature in pH 6.8 phosphate buffer, skim milk, whole milk, reconstituted whole milk powder, and unprocessed raw milk. The overall results confirmed that milk greatly improves the solubility of poorly water-soluble drugs. However, the extent of improvement and mechanism of solubilization appeared unique for each drug, highlighting the importance of evaluating milk solubility experimentally. The method used in this exploratory study can be applied in future investigations of a broader range of drugs and milk-related vehicles.

biochemistry↗

bioRxiv2022

Characterization of three-dimensional bone-like tissue growth and organization under influence of curvature and directional fluid flow

The transition in the field of bone tissue engineering from bone regeneration to three-dimensional in vitro models has come with the challenge of recreating a dense and anisotropic bone-like extracellular matrix with cell culture. The creation of such an organized bone-like extracellular matrix has received little attention thus far. Although the mechanism by which bone extracellular matrix gains its structure is not fully understood, curvature (especially concavities), mechanical loading due to deformations or directional fluid flow, and osteocyte signaling have been identified as potential contributors. Here, guided by computational simulations, we evaluated three-dimensional cell and bone-like tissue growth and organization in a concave channel with and without directional fluid flow stimulation. Human bone-marrow derived mesenchymal stromal cells were seeded on donut-shaped silk fibroin scaffolds and stimulated to undergo osteogenic differentiation for 42 days statically or in a flow perfusion bioreactor. Constructs were investigated for cell distribution, and tissue growth and organization on day 14, 28, and 42. As a result, directional fluid flow was able to improve bone-like tissue growth but not organization. After 28 days of culture, when osteogenic differentiation was likely accomplished, cells tended to have a small preference for orientation in the tangential (i.e., circumferential) direction of the channel. Based on our results, we suggest that three-dimensional bone-like tissue anisotropy might be guided by curvature, while extracellular matrix production can be increased through the application of fluid shear stress. With this study, an initial attempt in three-dimensions was made to improve the resemblance of in vitro produced bone-like extracellular matrix to the physiological bone extracellular matrix.

bioengineering↗

bioRxiv2022

A unique peptide recognition mechanism by the human relaxin family peptide receptor 4 (RXFP4)

Members of the insulin superfamily regulate a variety of biological processes through two types of target-specific but structurally conserved peptides, insulin/insulin-like growth factors and relaxin/insulin-like peptides. The latter bind to the human relaxin family peptide receptors (RXFPs), which are class A G protein-coupled receptors (GPCRs), to exert pleiotropic actions. Here, we report three cryo-electron microscopy structures of RXFP4-Gi protein complexes in the presence of the endogenous ligand insulin-like peptide 5 (INSL5) or one of the two small molecule agonists, compound 4 and DC591053, both were discovered through medicinal chemistry efforts. The B chain of INSL5 adopts a single -helix that penetrates into the orthostatic pocket, while the A chain sits above the orthosteric pocket to interact with the extracellular surface of RXFP4, revealing a unique peptide-binding mode previously unknown. Together with mutagenesis and functional analyses, the key determinants responsible for the peptidomimetic agonism and subtype selectivity were identified. DC591053 selectively mimicked the action of INSL5 at RXFP4 whereas compound 4 activated both RXFP3 and RXFP4. Comparison of peptide binding modes within the insulin superfamily displayed diverse interaction mechanisms distinct to each type of the peptides. Our findings not only provide valuable insights into ligand recognition and subtype selectivity among class A GPCRs, but also expand the knowledge of signaling mechanisms in the insulin superfamily.

molecular biology↗

bioRxiv2022

Utilizing a Cell-free Protein Synthesis Platform for Natural Product Synthesis

Natural products are a great source of pharmaceuticals, providing a majority of all small molecule drugs that exist today. However, creating natural products through organic synthesis or in heterologous hosts can be difficult and time-consuming. Therefore, to allow for easier screening and production of natural products, we demonstrated the use of a cell-free protein synthesis (CFPS) system to partially assemble natural products in vitro using coupled enzyme reactions. The tea caffeine synthase TCS1 was utilized to synthesize caffeine within a CFPS system. Cell-free systems also provide the benefit of allowing the use of substrates that would normally be toxic in a cellular environment to synthesize novel products. The automation and reduced metabolic engineering requirements of CFPS systems combined with other synthesis methods can allow for the efficient generation of new compounds.

synthetic biology↗

bioRxiv2022

A Unified Catalog of 19,251 Non-human Reference Species Genomes Provides New Insights into the Mammalian Gut Microbiomes

The gut microbiota is essential for host health and survival. Here, using samples from animals living in the Qinghai-Tibetan Plateau, we recovered 119,568 metagenome-assembled genomes (MAGs) that were clustered into 19,251 species-level genome bins (SGBs) of which most represent novel species. We present a novel mechanism shaping mammalian gut microbiomes using ancestral founder bacteria (AFB) as a core skeleton and recurring lineage-specific gains of microbial species that are transferred frequently among multiple hosts, not strictly limited by host phylogeny. Such lineage specific gains are responsible for increasing gut microbial diversity, maintaining functional stability, and endowing specific functions for host adaptions. Our analyses did not support the existence of co-phylogeny or co-speciation events between mammal hosts and their individual gut symbionts. The results presented in this study not only reveal novel unique gut microbial species and offer insight of value for understanding the diversity, stability, functionality of the mammalian gut microbiomes, and the co-evolution with their hosts, but also emphasize that animals living in extreme environments are a promising resource for the discovery of novel biological functions.

microbiology↗

bioRxiv2022

Patterning of the female reproductive tract along antero-posterior and dorso-ventral axes is dependent on Amhr2+ mesenchyme in mice

Morphogenesis of the female reproductive tract is regulated by the mesenchyme. However, the identity of the mesenchymal lineage that directs the patterning of the female reproductive tract has not been determined. Using in vivo genetic cell ablation, we identified Amhr2+ mesenchyme as an essential mesenchymal population in patterning the female reproductive tract. After partial ablation of Amhr2+ mesenchymal cells, the oviduct failed to develop its characteristic coiling due to decreased epithelial proliferation and tubule elongation during development. The uterus displayed a reduction in size and showed decreased cellular proliferation in both epithelial and mesenchymal compartments. More importantly, in the uterus, partial ablation of Amhr2+ mesenchyme caused abnormal lumen shape and altered the direction of its long axis from the dorsal-ventral axis to the left-right axis (i.e. perpendicular to the dorsal-ventral axis). Despite these morphological defects, epithelia underwent normal differentiation into secretory and ciliated cells in the oviduct and glandular epithelial cells in the uterus. These results demonstrated that Amhr2+ mesenchyme can direct female reproductive tract morphogenesis by regulating epithelial proliferation and lumen shape without affecting the differentiation of epithelial cell types.

developmental biology↗

bioRxiv2022

A Cambrian soft-bodied conical animal illustrates the origins of lophophorate phyla

The origin and early evolution of lophotrochozoans remain a difficult but crucial issue in reconstructing metazoan phylogeny. Exceptionally preserved fossils have provided hopeful information for resolving this lophotrochozoan problem. Here we identify that Conicula striata, a soft-bodied conical animal from the early Cambrian Chengjiang Lagerstatte, has mosaic characteristics of different lophophorate phyla. C. striata possesses a phoronid-like vermiform trunk housing a U-shaped gut and a coiled lophophore comprising [≥]12 arms with numerous tentacles, but it also bears brachiopod-like features including an undivided mantle enclosing lophophore and a pedicle-like protrusion on annulated trunk. Phylogenetic analysis retrieves C. striata as a total-group lophophorate and as an intermediate taxon between Phoronida and Brachiopoda. This suggests that the bivalved architecture of brachiopods originated from an undivided mantle in a phoronid-like ancestor, and that the ancestral vermiform trunk became reduced during the origin of Brachiopoda, illuminating the origins of body plans in the lophophorate phyla.

paleontology↗

bioRxiv2022

Hiplot: a comprehensive and easy-to-use web service boosting publication-ready biomedical data visualization

Modern web techniques provide an unprecedented opportunity for leveraging complex biomedical data generating in clinical, omics, and mechanism experiments. Currently, the functions for carrying out publication-ready biomedical data visualization represent primary technical hurdles in the state-of-art omics-based web services, whereas the demand for visualization-based interactive data mining is ever-growing. Here, we propose an easy-to-use web service, Hiplot (https://hiplot.com.cn), equipping with comprehensive and interactive biomedical data visualization functions (230+) including basic statistics, multi-omics, regression, clustering, dimensional reduction, meta-analysis, survival analysis, risk modeling, etc. We used the demo and real datasets to demonstrate the usage workflow and the core functions of Hiplot. It permits users to conveniently and interactively complete a few specialized visualization tasks that previously could only be done by senior bioinformatics or biostatistics researchers. A modern web client with efficient user interfaces and interaction methods has been implemented based on the custom components library and the extensible plugin system. The versatile output can also be produced in different environments via using the cross-platform portable command-line interface (CLI) program, Hctl. A switchable view between the editable data table and the file uploader/path selection could facilitate data importing, previewing, and exporting, while the plumber-based response strategy significantly reduced the time costs for generating basic scientific graphics. Diversified layouts, themes/styles, and color palettes in this website allow users to create high-quality and publication-ready graphics. Researchers devoted to both life and data science may benefit from the emerging web service.

bioinformatics↗

bioRxiv2022

Contribution of the Wolffian duct mesenchyme to the formation of the female reproductive tract

The female reproductive tract develops from its embryonic precursor, the Mullerian duct. In close proximity to the Mullerian duct lies the precursor for the male reproductive tract, the Wolffian duct, which is eliminated in the female embryo during sexual differentiation. We discovered that a component of the Wolffian duct, its mesenchyme, is not eliminated after sexual differentiation. Instead, the Wolffian duct mesenchyme underwent changes in transcriptome and chromatin accessibility from male tract to female tract identity, and became a unique mesenchymal population in the female reproductive tract with localization and transcriptome distinct from the mesenchyme derived from the Mullerian duct. Partial ablation of the Wolffian duct mesenchyme stunted the growth of the fetal female reproductive tract. These findings reveal a new fetal origin of mesenchymal tissues for female reproductive tract formation and reshape our understanding of sexual differentiation of reproductive tracts. Significance statementA female embryo initially possesses both the primitive female and male reproductive tracts, also known as the Mullerian and Wolffian duct. During sexual differentiation, the female eliminates the Wolffian duct and maintains the Mullerian duct that eventually differentiates into the female reproductive tract organs. However, in this paper, we show the female embryo retains mesenchymal cells surrounding the Wolffian duct for its reproductive tract formation. When incorporated into the female reproductive tract organs, the Wolffian duct mesenchyme shows unique anatomical localization and transcriptome and plays critical roles in female reproductive tract growth. This discovery provides new insights into female reproductive tract development and advances our understanding of sexual differentiation of reproductive tracts.

developmental biology↗

bioRxiv2022

An in vitro model of fibrosis using crosslinked native extracellular matrix-derived hydrogels to modulate biomechanics without changing composition

Extracellular matrix (ECM) is a dynamic network of proteins, proteoglycans and glycosaminoglycans, providing structure to the tissue and biochemical and biomechanical instructions to the resident cells. In fibrosis, the composition and the organization of the ECM are altered, and these changes influence cellular behaviour. Biochemical (i. e. protein composition) and biomechanical changes in ECM take place simultaneously in vivo. Investigating these changes individually in vitro to examine their (patho)physiological effects has been difficult. In this study, we generated an in vitro model to reflect the altered mechanics of a fibrotic microenvironment through applying fibre crosslinking via ruthenium/sodium persulfate crosslinking on native lung ECM-derived hydrogels. Crosslinking of the hydrogels without changing the biochemical composition of the ECM resulted in increased stiffness and decreased viscoelastic stress relaxation. The altered stress relaxation behaviour was explained using a generalized Maxwell model. Fibre analysis of the hydrogels showed that crosslinked hydrogels had a higher percentage of matrix with a high density and a shorter average fibre length. Fibroblasts seeded on ruthenium-crosslinked lung ECM-derived hydrogels showed myofibroblastic differentiation with a loss of spindle-like morphology together with greater -smooth muscle actin (-SMA) expression, increased nuclear area and circularity without any decrease in the viability, compared with the fibroblasts seeded on the native lung-derived ECM hydrogels. In summary, ruthenium crosslinking of native ECM-derived hydrogels provides an exciting opportunity to alter the biomechanical properties of the ECM-derived hydrogels while maintaining the protein composition of the ECM to study the influence of mechanics during fibrotic lung diseases.

pathology↗

bioRxiv2022

Ligand-independent modulation of GIPR signaling by splice variants

Glucose-dependent insulinotropic polypeptide receptor (GIPR) is a potential drug target for metabolic disorders. It works with glucagon-like peptide-1 receptor (GLP-1R) and glucagon receptor (GCGR) in humans to maintain glucose homeostasis. Unlike the other two receptors, GIPR has at least 7 reported (EMBL-EBI, 2022; NCBI, 2022a, 2022b) splice variants (SVs) with previously undefined functions. To explore their roles in endogenous peptide mediated GIPR signaling, we investigated the outcome of co-expressing each of the four SVs in question with GIPR in terms of ligand binding, cAMP accumulation, Gs activation, {beta}-arrestin recruitment and cell surface localization. The effects of these SVs on intracellular cAMP responses modulated by receptor activity-modifying proteins (RAMPs) were also studied. It was found that while SVs of GIPR neither bound to the hormone nor affected its signal transduction per se, they differentially regulated GIPR-mediated cAMP and {beta}-arrestin responses. Specifically, SV1 and SV4 were preferable to Gs signaling, SV3 was biased towards {beta}-arrestin recruitment, whereas SV2 was inactive on both pathways. In the presence of RAMPs, only SV1 and SV4 synergized the repressive action of RAMP3 on GIP-elicited cAMP production. The results suggest a new form of signal bias that is constitutive and ligand-independent, thereby expanding our knowledge of biased signaling beyond pharmacological manipulation (i.e., ligand specific) as well as constitutive and ligand-dependent (e.g., SV1 of the growth hormone-releasing hormone receptor).

molecular biology↗

bioRxiv2022

Control of Leaf Width by the APC/CTAD1-WL1-NAL1 Pathway in Rice

Leaf morphology is one of the most important features of the ideal plant architecture. However, the genetic and molecular mechanisms controlling leaf morphology in crops remain largely unknown, despite their central importance. Here we demonstrate that the APC/CTAD1-WL1-NAL1 pathway regulates leaf width in rice, and mutation of WL1 leads to width leaf variation. WL1 interacts with TAD1 and is degraded by APC/CTAD1, with the loss of TAD1 function resulting in narrow leaves. The WL1 protein directly binds to the regulatory region of NAL1 and recruits the corepressor TOPLESS-RELATED PROTEIN to inhibit NAL1 expression by down-regulating the level of histone acetylation of chromatin. Furthermore, biochemical and genetic analyses revealed that TAD1, WL1, and NAL1 function in a common pathway to control leaf width. Our study establishes an important framework for the APC/CTAD1-WL1-NAL1 pathway-mediated control of leaf width in rice and introduces novel perspectives for using this regulatory pathway for improving crop plant architecture.

plant biology↗

bioRxiv2022

Engineering SARS-CoV-2 neutralizing antibodies for increased potency and reduced viral escape

The rapid spread of SARS-CoV-2 variants poses a constant threat of escape from monoclonal antibody and vaccine countermeasures. Mutations in the ACE2 receptor binding site on the surface S protein have been shown to disrupt antibody binding and prevent viral neutralization. Here, we use a directed evolution-based approach to engineer three neutralizing antibodies for enhanced binding to S protein. The engineered antibodies showed increased in vitro functional activity in terms of neutralization potency and/or breadth of neutralization against viral variants. Deep mutational scanning revealed that higher binding affinity reduced the total number of viral escape mutations. Studies in the Syrian hamster model showed two examples where the affinity matured antibody provided superior protection compared to the parental antibody. These data suggest that monoclonal antibodies for anti-viral indications could benefit from in vitro affinity maturation to reduce viral escape pathways and appropriate affinity maturation in vaccine immunization could help resist viral variation.

bioengineering↗

bioRxiv2021

A combination of potently neutralizing monoclonal antibodies isolated from an Indian convalescent donor protects against the SARS-CoV-2 delta variant

Although efficacious vaccines have significantly reduced the morbidity and mortality due to COVID-19, there remains an unmet medical need for treatment options, which monoclonal antibodies (mAbs) can potentially fill. This unmet need is exacerbated by the emergence and spread of SARS-CoV-2 variants of concern (VOCs) that have shown some resistance to vaccine responses. Here we report the isolation of two highly potently neutralizing mAbs (THSC20.HVTR04 and THSC20.HVTR26) from an Indian convalescent donor, that neutralize SARS-CoV-2 VOCs at picomolar concentrations including the delta variant (B.1.617.2). These two mAbs target non-overlapping epitopes on the receptor-binding domain (RBD) of the spike protein thereby preventing the virus attachment to its host receptor, human angiotensin converting enzyme-2 (hACE2). Furthermore, the mAb cocktail demonstrated protection against the Delta variant at low antibody doses when passively administered in the K18 hACE2 transgenic mice model, highlighting their potential as cocktail for prophylactic and therapeutic applications. Developing the capacity to rapidly discover and develop mAbs effective against highly transmissible pathogens like coronaviruses at a local level, especially in a low- and middle-income country (LMIC) such as India, will enable prompt responses to future pandemics as an important component of global pandemic preparedness. HighlightsO_LIIdentification of an Indian convalescent donor prior to emergence of SARS-CoV-2 Delta variant whose plasma demonstrated neutralization breadth across SARS-CoV-2 variants of concern (VOCs). C_LIO_LITwo (THSC20.HVTR04 and THSC20.HVTR26) monoclonal antibodies isolated from peripheral memory B cells potently neutralize SARS-CoV-2 VOCs: Alpha, Beta, Gamma, Delta and VOIs: Kappa and Delta Plus. C_LIO_LITHSC20.HVTR04 and THSC20.HVTR26 target non-competing epitopes on the receptor binding domain (RBD) and represent distinct germline lineages. C_LIO_LIPassive transfer of THSC20.HVTR04 and THSC20.HVTR26 mAbs demonstrated protection against Delta virus challenge in K18-hACE2 mice at low antibody doses. C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=142 SRC="FIGDIR/small/474152v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@1f1b55corg.highwire.dtl.DTLVardef@1b9b438org.highwire.dtl.DTLVardef@e6d2a6org.highwire.dtl.DTLVardef@f92cd_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2021

Molecular insights into antibody-mediated protection against the prototypic simian immunodeficiency virus

SIVmac239 infection of macaques is a favored model of human HIV infection. However, the SIVmac239 envelope (Env) trimer structure, glycan occupancy, and the targets and ability of neutralizing antibodies (nAbs) to protect against SIVmac239 remain unknown. Here, we report the isolation of SIVmac239 nAbs that recognize a glycan hole and the V1/V4 loop. A high-resolution structure of a SIVmac239 Env trimer-nAb complex shows many similarities to HIV and SIVcpz Envs, but with distinct V4 features and an extended V1 loop. Moreover, SIVmac239 Env has a higher glycan shield density than HIV Env that may contribute to poor or delayed nAb responses in SIVmac239-infected macaques. Passive transfer of a nAb protects macaques from repeated low dose intraveneous SIVmac239 challenge at serum titers comparable to those described for protection of humans against HIV infection. Our results provide structural insights for vaccine design and shed light on antibody-mediated protection in the SIV model.

immunology↗