Biology subjects

Chen, R.

Publications and source records attributed to Chen, R..

At least 361 records · Page 20Linked to original sources

bioRxiv2019

Vascularized human cortical organoids model cortical development in vivo

Modelling the neuronal progenitor proliferation and organization processes that produce mature cortical neuron subtypes is essential for the study of human brain development and the search for potential cell therapies. To provide a vascularized and functional model of brain organoids, we demonstrated a new paradigm to generate vascularized organoids that consist of typical human cortical cell types and recapitulate the lamination of the neocortex with a vascular structure formation for over 200 days. In addition, the observation of the sEPSCs (spontaneous Excitatory Postsynaptic Potential) and sIPSCs (spontaneous Inhibitory Postsynaptic Potential) and the bidirectional electrical transmission indicated the presence of chemical and electrical synapses in the vOrganoids. More importantly, the single-cell RNA-seq analysis illustrated that the vOrganoids exhibited microenvironments to promote neurogenesis and neuronal maturation that resembled in vivo processes. The transplantation of the vOrganoids to the mouse S1 cortex showed human-mouse co-constructed functional blood vessels in the grafts that could promote the survival and integration of the transplanted cells to the host. This vOrganoid culture method could not only serve as a model to study human cortical development and to explore brain disease pathology but could also provide potential prospects for new cell therapies for neural system disorders and injury.

neuroscience↗

bioRxiv2019

Molecular Profiles of Matched Primary and Metastatic Tumor Samples Support an Evolutionary Model of Breast Cancer

The interpretation of accumulating genomic data with respect to tumor evolution and cancer progression requires integrated models. We developed a computational approach that enables the construction of disease progression models using static sample data. Application to breast cancer data revealed a linear, branching evolutionary model with two distinct trajectories for malignant progression. Here, we used the progression model as a foundation to investigate the relationships between matched primary and metastasis breast tumor samples. Mapping paired data onto the model confirmed that molecular breast cancer subtypes can shift during progression, and supported directional tumor evolution through luminal subtypes to increasingly malignant states. Cancer progression modeling through the analysis of available static samples represents a promising breakthrough. Further refinement of a roadmap of breast cancer progression will facilitate the development of improved cancer diagnostics, prognostics and targeted therapeutics.

bioinformatics↗

bioRxiv2019

Optimal recovery of missing values for non-negative matrix factorization

We extend the approximation-theoretic technique of optimal recovery to the setting of imputing missing values in clustered data, specifically for non-negative matrix factorization (NMF), and develop an implementable algorithm. Under certain geometric conditions, we prove tight upper bounds on NMF relative error, which is the first bound of this type for missing values. We also give probabilistic bounds for the same geometric assumptions. Experiments on image data and biological data show that this theoretically-grounded technique performs as well as or better than other imputation techniques that account for local structure.

bioinformatics↗

bioRxiv2019

Deep Learning Approach to Identifying Breast Cancer Subtypes Using High-Dimensional Genomic Data

MotivationCancer subtype classification has the potential to significantly improve disease prognosis and develop individualized patient management. Existing methods are limited by their ability to handle extremely high-dimensional data and by the influence of misleading, irrelevant factors, resulting in ambiguous and overlapping subtypes.\n\nResultsTo address the above issues, we proposed a novel approach to disentangling and eliminating irrelevant factors by leveraging the power of deep learning. Specifically, we designed a deep learning framework, referred to as DeepType, that performs joint supervised classification, unsupervised clustering and dimensionality reduction to learn cancer-relevant data representation with cluster structure. We applied DeepType to the METABRIC breast cancer dataset and compared its performance to state-of-the-art methods. DeepType significantly outperformed the existing methods, identifying more robust subtypes while using fewer genes. The new approach provides a framework for the derivation of more accurate and robust molecular cancer subtypes by using increasingly complex, multi-source data.\n\nAvailability and implementationAn open-source software package for the proposed method is freely available at www.acsu.buffalo.edu/~yijunsun/lab/DeepType.html.

bioinformatics↗

bioRxiv2019

Long noncoding RNA AVAN promotes antiviral innate immunity by interacting with TRIM25 and enhancing the transcription of FOXO3a

Accumulating evidence has shown that long noncoding RNAs (lncRNAs) are involved in several biological processes, including immune responses. However, the role of lncRNAs in antiviral innate immune responses remains largely unexplored. Here, we identify an uncharacterized human lncRNA from influenza A virus (IAV) patients, antivirus and activate neutrophil (AVAN), that is significantly up-regulated upon virus infection. Mechanistically, nuclear lncRNA-AVAN positively regulates the transcription of forkhead box O3A (FOXO3a) by associating with its promoter and inducing chromatin remodeling to promote neutrophil chemotaxis. Furthermore, we also found that cytoplasmic lncRNA-AVAN directly binds tripartite motif containing 25 (TRIM25) and enhances the association of TRIM25 and Retinoic acid inducible gene-1 proteins (RIG-I) and the ubiquitylation of RIG-I, thereby promoting TRIM25- and RIG-I-mediated antiviral innate immune signaling. More importantly, we enforced the expression of AVAN in transgenic mice and found that it significantly alleviated IAV virulence and virus production. Collectively, these findings highlight the potential clinical implications of lncRNA-AVAN as a key positive regulator of the antiviral innate immune response and a promising target for developing broad antiviral therapeutics.

immunology↗

bioRxiv2019

The gut microbiota regulates mouse biliary regenerative responses

Injury to the biliary epithelium triggers cholangiopathies. However, factors involved in regulating the pathogenesis remains incompletely understood. Here, we report that the gut microbiota is important in regulating hepatobiliary fibroproliferative regenerative process. In helminth Clonorchis sinensis-induced bile duct injury model, wild-type mice showed more extensive peribiliary fibroproliferative responses than non-littermate IL-33-deficient mice. However, these reactions could be attenuated by co-housing of the animals together. In the meantime, the relatively fibroproliferative-resistant IL-33-deficient mice could become fibroproliferative-responsive especially in large intrahepatic bile duct by antibiotics treatment. Furthermore, microbiota-derived metabolite butyrate was able to inhibit biliary organoid expansion in vitro and temper 3,5-diethoxycarbonyl-1,4-dihydrocollidine-induced biliary fibrosis in vivo. Together, our data implies a potential way of management of hepatobiliary diseases by modulating gut microbiota.

microbiology↗

bioRxiv2019

Analysis on epidemiological characteristics of 4 species natural-focal diseases in Shandong Province, China in 2009-2017: a descriptive analysis

BackgroundNatural-focal diseases have always been a kind of serious disease that endangers human health. It threatens about 100 million people in Shandong Province, and causes illness in thousands of people each year. However, information on the epidemiological characteristics of natural-focal diseases in Shandong Province has been limited. The purpose of the study is to describe and analyze the epidemiological characteristics of natural-focal diseases in Shandong Province, 2009-2017. MethodsWe describe the incidence and distribution of 4 species natural-focal diseases in Shandong Province using surveillance data from 2009-2017. ResultsFrom 2009-2017, 11123 cases of 4 species natural-focal diseases including 257 deaths were reported in Shandong Province, China. The 4 species natural-focal diseases were severe fever with thrombocytopenia syndrome (SFTS), human granulocytic anaplasmosis (HGA), typhus and scrub typhus respectively. The high-risk groups of the 4 species diseases all were farmers and the elderly. The incidence rate of scrub typhus was significantly higher in females, however, this difference was not seen in the other 3 diseases. The 4 species diseases were mainly clustered in middle-southern part of Shandong (Mount Yimeng) and Shandong Peninsula (Laoshan Mountain). The annual incidence of SFTS and scrub typhus had increased in the mass, typhus had been relatively stable, and HGA had declined. However, the popular range of SFTS had been expanding, HGA had been shrinking, and typhus and scrub typhus were unchanged. The epidemic period of SFTS and HGA was from May to October, typhus was from October to November, scrub typhus was from September to November in Shandong Province. The fatality rates of SFTS, typhus, scrub typhus, HGA were 9.19%, 0%, 0.01%, 2.24%, respectively. ConclusionsOur study described and analyzed the prevalence of natural-focal diseases in Shandong, and confirmed that age was closely related to the SFTS fatality rate. This study may be applicable to an improved understanding of the prevalence of natural-focal diseases in Shandong Province in recent years and the better development of the accurate prevention and control strategies for natural-focal diseases in Shandong Province. Author SummaryNatural-focal diseases are a serious public health problem in Shandong Province, China. It threatens about 100 million people in Shandong Province, and causes illness in thousands of people each year. This study used the monitoring data from Shandong Province for 2009-2017 to describe and analyze the epidemiological characteristics of the 4 species natural-focal diseases. The results showed that the risk population of natural-focal diseases in Shandong Province was farmers and the elderly, the epidemic season was mainly in summer and autumn, the middle-southern part of Shandong Province and Shandong Peninsula were more seriously affected compared with other regions. In addition, the epidemic area of SFTS was expanded, with a fatality rate of 9.19%. These findings indicated that public awareness of natural-focal diseases should be raised in the epidemic focus, especially for farmers, and further efforts should be strengthen specially in high-risk areas and during the epidemic season.

epidemiology↗

bioRxiv2019

The Genetic Basis of Transcriptional and Spatial Heterogeneity of Squamous Features in Pancreatic Ductal Adenocarcinoma

Recent studies indicate that pancreatic cancer expression profiles are variable and largely reflect a classical or basal-type phenotype. We performed genetic sequencing, RNA-seq, and histologic review of multiregion sampled pancreatic cancers and found that squamous and squamoid features, indicators of poor prognosis, correlate with a "basal-like" expressional type. Cancers with squamous features were more likely to have truncal mutations in chromatin modifier genes and intercellular heterogeneity for MYC amplification that was associated with entosis. In most patients the basal phenotype coexisted with a glandular component, and phylogenetic studies indicated that it arose from a subclonal population in the tumor. These data provide a unifying paradigm for understanding the interrelationship of basal-type features, squamous histology, and somatic mutations in chromatin modifier genes in the context of the clonal evolution of pancreatic cancer.

cancer biology↗

bioRxiv2019

ADAMDEC1 maintains a novel growth factor signaling loop in cancer stem cells

Glioblastomas (GBM) are lethal brain tumors where poor outcome is attributed to cellular heterogeneity, therapeutic resistance, and a highly infiltrative nature. These characteristics are preferentially linked to GBM cancer stem cells (GSCs), but how GSCs maintain their stemness is incompletely understood and the subject of intense investigation. Here, we identify a novel signaling loop that induces and maintains GSCs. This loop consists of an atypical metalloproteinase, a disintegrin and metalloproteinase domain-like protein decysin 1 (ADAMDEC1), secreted by GSCs. ADAMDEC1 rapidly solubilizes fibroblast growth factor-2 (FGF2) to stimulate FGF receptor 1 (FGFR1) expressed on GSCs. This signaling axis induces upregulation of Zinc finger E-box-binding homeobox 1 (ZEB1) that regulates ADAMDEC1 expression, creating a positive feedback loop. Genetic or pharmacological targeting of components of this axis attenuates self-renewal and tumor growth. These findings reveal a new signaling axis for GSC maintenance and highlight ADAMDEC1 and FGFR1 as potential therapeutic targets in GBM. Statement of SignificanceCancer stem cells (CSC) drive tumor growth in many cancers including glioblastoma. We identified a novel sheddase, a disintegrin and metalloproteinase domain-like protein decysin 1, that initiates a fibroblast growth factor autocrine loop to promote stemness in CSCs. This loop can be targeted to reduce glioblastoma growth.

cancer biology↗

bioRxiv2019

Registration for Image-Based Transcriptomics: Parametric Signal Features and Multivariate Information Measures

Image-based transcriptomics involves determining spatial patterns in gene expression across cells and tissues. Image registration is a necessary component of data analysis pipelines that study gene expression levels across different cells and intracellular structures. We consider images from multiplexed single molecule fluorescent in situ hybridization (smFISH) and multiplexed in situ sequencing (ISS) datasets from the Human Cell Atlas project and demonstrate a novel approach to groupwise image registration using a parametric representation of images based on finite rate of innovation sampling, together with practical optimization of empirical multivariate information measures.

bioinformatics↗

bioRxiv2019

Moraxellaceae and Moraxella interact with the altered airway mycobiome in asthma

Airway microbial-microbial interaction plays an important role in chronic airway inflammatory diseases such as asthma. Moraxella is widely regarded as a human respiratory tract pathogen. We aimed to investigate the interactions among Moraxella, Moraxellaceae (to which Moraxella belongs) and the airway microbiome in asthma. Induced sputum samples were obtained from 116 asthma patients and 29 healthy individuals, and the bacterial/fungal communities were profiled using 16S rRNA and ITS1 DNA gene sequencing. We found that asthma patients harboured significantly greater airway bacterial and fungal -diversity than that of healthy individuals. Moraxellaceae, Moraxella and Moraxella otu19 (bacteria), and Schizophyllaceae, Polyporaceae, Aspergillus, Schizophyllum and Candida (fungi) were increased in the airway of asthma. Moreover, Moraxellaceae, Schizophyllaceae, Polyporaceae and Candida were positively associated with airway fungal -diversity. Correlation networks revealed Moraxellaceae and Moraxella as microbial \"hubs\" in asthma that had significant negative connections with multiple bacterial communities, such as Leptotrichiaceae, Lachnospiraceae, Peptostreptococcaceae, Porphyromonadaceae, Prevotella, Veillonella, Rothia and Leptotrichia, but positive interactions with fungal communities such as Schizophyllaceae, Polyporaceae, Candida and Meyerozyma. Together, our finding revealed an altered microbiome and complex microbial-microbial interactions in the airway of asthma. Moraxellaceae and Moraxella showed significant interactions with the airway mycobiome, providing potential insights into the novel pathogenic mechanisms of asthma.\n\nIMPORTANCEWith the advent of culture-independent techniques, growing evidence suggests that the airway microbiome is closely correlated with chronic respiratory diseases such as asthma. The complex microbial-microbial interaction exists in the airways of both healthy individuals and patients with respiratory diseases, which is of great significance for the pathogenesis and disease progression of asthma. In this study, we evaluated the airway dysbiosis in asthma patients, described the interaction between Moraxellaceae, Moraxella and airway bacterial/fungal communities, and it contributes to further understanding the pathogenic mechanisms of asthma.

microbiology↗

bioRxiv2018

Single-nuclei RNA-seq on human retinal tissue provides improved transcriptome profiling.

Gene expression profiling is an effective way to provide insights into cell function. However, for heterogeneous tissues, bulk RNA-Seq can only provide the average gene expression profile for all cells from the tissue, making the interpretation of the sequencing result challenging. Single-cell RNA-seq, on the other hand, generates transcriptomic profiles of individual cell and cell types, making it a powerful method to decode the heterogeneity in complex tissues. The retina is a heterogeneous tissue composed of multiple cell types with distinct functions. Here we report the first single-nuclei RNA-seq transcriptomic study on human neural retinal tissue to identify transcriptome profile for individual cell types. Six retina samples from three healthy donors were profiled and RNA-seq data with high quality was obtained for 4730 single nuclei. All seven major cell types were observed from the dataset and signature genes for each cell type were identified by differential gene express analysis. The gene expression of the macular and peripheral retina was compared at the cell type level, showing significant improvement from previous bulk RNA-seq studies. Furthermore, our dataset showed improved power in prioritizing genes associated with human retinal diseases compared to both mouse single-cell RNA-seq and human bulk RNA-seq results. In conclusion, we demonstrated that feasibility of obtaining single cell transcriptome from human frozen tissues to provide additional insights that is missed by either the human bulk RNA-seq or the animal models.

genomics↗

bioRxiv2018

A missense mutation of Ip3r1 in Dp2 mice leads to short-term mydriasis and unfolded protein response in the iris constrictor muscles

Ip3r1 encodes an inositol 1,4,5-triphosphate-responsive calcium channel. Mutations in the Ip3r1 gene in humans may cause Gillespie syndrome (GS) typically presents as fixed dilated pupils in affected infants, which was referred to as iris hypoplasia. However, there is no report of mice with Ip3r1 heterozygous mutations showing dilated pupils. Here, we report a new Ip3r1 allele (dilated pupil 2; Dp2) with short-term dilated pupil phenotype derived from an N-ethyl-N-nitrosourea (ENU) mutagenesis screen. This allele carries a G5927A transition mutation, which is predicted to result in a C1976Y amino acid change in the open reading frame. Histology and pharmacological tests show that the dilated pupil phenotype is a mydriasis caused by the functional defect in the iris constrictor muscles in Dp2. The dilated pupil phenotype in Dp2 was referred to as mydriasis and excluding iris hypoplasia. IHC analysis revealed increased expression of BIP protein, the master regulator of unfolded protein response (UPR) signaling, in Dp2 mice that did not recover. Apart from the dilated pupil phenotype (mydriasis), there are no other abnormal phenotypes including Ip3r1-related ataxia that may be found. This study is the first report of an Ip3r1 mutation being associated with the mydriasis phenotype. Dp2 mice represent a valuable self-healing model that may be used to study the therapeutic approach for Ip3r1-related diseases or diseases caused by similar pathomechanisms.

genetics↗

bioRxiv2018

GRIPT: A novel case-control analysis method for Mendelian disease gene discovery

Despite rapid progress of next-generation sequencing (NGS) technologies, the disease-causing genes underpinning about 50% of Mendelian diseases remain elusive. One main challenge is the high genetic heterogeneity of Mendelian diseases in which similar phenotypes are caused by different genes and each gene only accounts for a small proportion of the patients. To overcome this gap, we developed a novel method, the Gene Ranking, Identification and Prediction Tool (GRIPT), for performing case-control analysis of NGS data. Analyses of simulated and real datasets show that GRIPT is well-powered for disease gene discovery, especially for diseases with high locus heterogeneity.

genomics↗

bioRxiv2018

Centrosome-nuclear envelope tethering and microtubule motor-based pulling forces collaborate in centrosome positioning during mitotic entry

Centrosome positioning relative to the nucleus and cell shape is highly regulated across cell types, during cell migration and during spindle formation in cell division. Across most sexually reproducing animals, centrosomes are provided to the oocyte through fertilization and must be positioned properly to establish the zygotic mitotic spindle. How centrosomes are positioned in space and time through the concerted action of key mitotic entry biochemical regulators including Protein Phosphatase 2A (PP2A-B55/SUR-6), biophysical regulators including Dynein and the nuclear lamina is unclear. Here, we uncover a role for PP2A-B55/SUR-6 in regulating centrosome positioning. Mechanistically, PP2A-B55/SUR-6 regulates nuclear size prior to mitotic entry, in turn affecting nuclear envelope-based Dynein density and motor capacity. Using computational simulations, PP2A-B55/ SUR-6 regulation of nuclear size and nuclear envelope Dynein density were both predicted to be required for proper centrosome positioning. Conversely, compromising nuclear lamina integrity led to centrosome detachment from the nuclear envelope and migration defects. Removal of PP2A-B55/SUR-6 and the nuclear lamina simultaneously further disrupted centrosome positioning, leading to unseparated centrosome pairs dissociated from the nuclear envelope. Taken together, we propose a model in which centrosomes migrate and are positioned through the concerted action of nuclear envelope-based Dynein pulling forces and cen-trosome-nuclear envelope tethering.

cell biology↗

bioRxiv2018

Physical and functional interaction between SET1/COMPASS complex component CFP-1 and a Sin3 HDAC complex

The CFP1 CXXC zinc finger protein targets the SET1/COMPASS complex to non-methylated CpG rich promoters to implement tri-methylation of histone H3 Ly4 (H3K4me3). Although H3K4me3 is widely associated with gene expression, the effects of CFP1 loss depend on chromatin context, so it is important to understand the relationship between CFP1 and other chromatin factors. Using a proteomics approach, we identified an unexpected link between C. elegans CFP-1 and a Rpd3/Sin3 histone deacetylase complex. We find that mutants of CFP-1, SIN-3, and the catalytic subunit SET-2/SET1 have similar phenotypes and misregulate common genes. CFP-1 directly binds SIN-3 through a region including the conserved PAH1 domain and recruits SIN-3 and the HDA-1/HDAC subunit to H3K4me3 enriched promoters. Our results reveal a novel role for CFP-1 in mediating interaction between SET1/COMPASS and a Sin3 HDAC complex at promoters and uncover coordinate regulation of gene expression by chromatin complexes having distinct activities.

genomics↗

bioRxiv2018

Structural and biochemical characterization on the cognate and heterologous interactions of the MazEF-mt9 TA system

The toxin-antitoxin (TA) modules widely exist in bacteria, and their activities are associated with the persister phenotype of the pathogen Mycobacterium tuberculosis (M. tb). M. tb causes Tuberculosis, a contagious and severe airborne disease. There are ten MazEF TA systems in M. tb, which play important roles in stress adaptation. How the antitoxins antagonize toxins in M. tb or how the ten TA systems crosstalk to each other are of interests, but the detailed molecular mechanisms are largely unclear. MazEF-mt9 is a unique member among the MazEF families due to its tRNase activity, which is usually carried out by the VapC family toxins. Here we present the cocrystal structure of the MazEF-mt9 complex at 2.7 [A]. By characterizing the association mode between the TA pairs through various characterization techniques, we found that MazF-mt9 not only bound its cognate antitoxin, but also the non-cognate antitoxin MazE-mt1, a phenomenon that could be also observed in vivo. Based on our structural and biochemical work, we proposed that the cognate and heterologous interactions among different TA systems work together to relieve MazF-mt9s toxicity to M. tb cells, which may facilitate their adaptation to the stressful conditions encountered during host infection.\n\nIMPORTANCETuberculosis (TB) is one of the most severe contagious diseases. Caused by Mycobacterium tuberculosis (M. tb), it poses a serious threat to human health. Additionally, TB is difficult to cure because of the multipledrug-resistant (MDR) and extensively drug-resistant (XDR) M. tb strains. Toxin-antitoxin (TA) systems have been discovered to widely exist in prokaryotic organisms with diverse roles, normally composed of a pair of molecules that antagonize each other. M. tb has ten MazEF systems, and some of them have been proved to be directly associated with the genesis of persisters and drug-resistance of M. tb. We here report the MazEF-mt9 complex structure, and thoroughly characterized the interactions between MazF-mt9 with MazEs within or outside the MazEF-mt9 family. Our study not only revealed the crosstalks between TA families and its significance to M. tb survival but also offers insights into potential anti-TB drug design.

biochemistry↗

bioRxiv2018

Epigenomic Profiling and Single-Nucleus-RNA-Seq Reveal Cis-Regulatory Elements in Human Retina, Macula and RPE and Non-Coding Genetic Variation.

Cis-regulatory elements (CREs) orchestrate the dynamic and diverse transcriptional programs that assemble the human central nervous system (CNS) during development and maintain its function throughout life. Genetic variation within CREs plays a central role in phenotypic variation in complex traits including the risk of developing disease. However, the cellular complexity of the human brain has largely precluded the identification of functional regulatory variation within the human CNS. We took advantage of the retina, a well-characterized region of the CNS with reduced cellular heterogeneity, to establish a roadmap for characterizing regulatory variation in the human CNS. This comprehensive resource of tissue-specific regulatory elements, transcription factor binding, and gene expression programs in three regions of the human visual system (retina, macula, retinal pigment epithelium/choroid) reveals features of regulatory element evolution that shape tissue-specific gene expression programs and defines the regulatory elements with the potential to contribute to mendelian and complex disorders of human vision.

neuroscience↗