Biology subjects

Wu, J.

Publications and source records attributed to Wu, J..

At least 775 records · Page 43Linked to original sources

bioRxiv2020

Molecular Typing of Human Respiratory Adenoviruses with Universal PCR and Sequencing Primers for Three Major Capsid Genes: Penton base, Hexon, and Fiber

Human adenoviruses (HAdVs) within species B, C, and E include the predominant types responsible for highly contagious and potentially severe respiratory infections. The traditional method to type these pathogens was based on virus neutralization and hemagglutination assays using antisera, which is both time-consuming and difficult, particularly due to the non-availability of reagents. Molecular typing based on partial characterization of HAdV hexon, as well as the restriction enzyme analysis (REA) of the genomics DNA, is difficult to identify recombinants. Here, a rapid, simple, and cost-effective molecular typing of respiratory HAdVs is presented. This incorporates three pairs of universal PCR primers that target the variable regions of the three major capsid genes, i.e. hexon, penton base and fiber genes. The protocol developed enables detection and typing of respiratory HAdVs within species B, C, and E, as well as of some strains within species D and F. Using this method, we surveyed a total of 100 children with acute respiratory infection caused by HAdVs in Hong Kong, Summer 2014 (July to October). 100 Throat swab specimens were collected. The samples were analyzed by PCR and the sequences were characterized by BLAST. HAdVs were detected in 98 out of 100 (98%) samples. The predominant HAdV type was species B type 3. Among the patients, 74 were of HAdV-B3 (74%), 10 were of HAdV-E4 (10%), 6 were of HAdV-C2 (21.7%), 2 were of HAdV-C6 (2%), 1 were of HAdV-B7 (2%), 1 were of HAdV-C1 (74%), and 2 were of recombinant types. The developed method allows the rapid identification of HAdVs with recombinant genomes, and bypasses the need for whole genome data, for the real-time surveillance of circulating adenovirus strains in immediate outbreaks and populations by clinical microbiologists, public health officers, and epidemiologists.

microbiology↗

bioRxiv2020

RBD mutations from circulating SARS-CoV-2 strains enhance the structure stability and infectivity of the spike protein

The current global pandemic of COVID-19 is caused by a novel coronavirus SARS-CoV-2. The SARS-CoV-2 spike protein receptor-binding domain (RBD) is the critical determinant of viral tropism and infectivity. To investigate whether naturally occurring mutations in the RBD during the early transmission phase have altered the receptor binding affinity and infectivity, firstly we analyzed in silico the binding dynamics between mutated SARS-CoV-2 RBDs and the human ACE2 receptor. Among 32,123 genomes of SARS-CoV-2 isolates (January through March, 2020), 302 non-synonymous RBD mutants were identified and clustered into 96 mutant types. The six dominant mutations were analyzed applying molecular dynamics simulations. The mutant type V367F continuously circulating worldwide displayed higher binding affinity to human ACE2 due to the enhanced structural stabilization of the RBD beta-sheet scaffold. The increased infectivity of V367 mutants was further validated by performing receptor-ligand binding ELISA, surface plasmon resonance, and pseudotyped virus assays. Genome phylogenetic analysis of V367F mutants showed that during the early transmission phase, most V367F mutants clustered more closely with the SARS-CoV-2 prototype strain than the dual-mutation variants (V367F + D614G) which emerged later and formed a distinct sub-cluster. The analysis of critical RBD mutations provides further insights into the evolutionary trajectory of SARS-CoV-2 under negative selection pressure and supports the continuing surveillance of spike mutations to aid in the development of new COVID-19 drugs and vaccines. ImportanceA novel coronavirus SARS-CoV-2 has caused the pandemic of COVID-19. The origin of SARS-CoV-2 was associated with zoonotic infections. The spike protein receptor-binding domain (RBD) is identified as the critical determinant of viral tropism and infectivity. Thus, whether the mutations in the RBD of the circulating SARS-CoV-2 isolates have altered the receptor binding affinity and caused them more infectious, should be paid more attentions to. Given that SARS-CoV-2 is a novel coronavirus, the significance of our research is in identifying and validating the RBD mutant types emerging during the early transmission phase that have increased human ACE2 receptor binding affinity and infectivity. The RBD mutation analysis provides insights into SARS-CoV-2 evolution. The continuous surveillance of RBD mutations with increased human ACE2 affinity in human or other animals is important and necessary, particularly when the direct correlation between the virus variations and vaccine effectiveness is underdetermined during the sustained COVID-19 pandemic.

microbiology↗

bioRxiv2020

Reactive oxygen species as important regulators of cell division

Currently, the role of reactive oxygen species (ROS) in plant growth is a topic of interest. In this study, we discuss the role of ROS in cell division. We analyzed ROS impact on the stiffness of plant cell walls and whether ROS play an important role in Brassica napus ability to adapt to cold stress. Cultivated sterile seedlings and calli of cold-tolerant cultivar 16NTS309 were subjected to cold stress at 25{degrees}C and 4{degrees}C, respectively. Under normal conditions, O2.- mainly accumulated in the leaf edges, shoot apical meristem, leaf primordia, root tips, lateral root primordia, calli of meristematic nodular tissues, cambia, vascular bundles and root primordia, which are characterized by high division rates. After exposure to cold stress, the malondialdehyde and ROS (O2.-) contents in roots, stems and leaves of cultivar 16NTS309 were significantly higher than under non-cold conditions (P < 0.05). ROS (O2.-) were not only distributed in these zones, but also in other cells, at higher levels than under normal conditions. A strong ROS-based staining appeared in the cell wall. The results support a dual role for apoplastic ROS, in which they have direct effects on the stiffness of the cell wall, because ROS cleave cell-wall, and act as wall loosening agents, thereby either promoting or restricting cellular division. This promotes the appearance of new shoots and a strong root system, allowing plants to adapt to cold stress.

plant biology↗

bioRxiv2020

Viral Architecture of SARS-CoV-2 with Post-Fusion Spike Revealed by Cryo-EM

Since December 2019, the outbreak of Coronavirus Disease 2019 (COVID-19) spread from Wuhan, China to the world, it has caused more than 87,000 diagnosed cases and more than 3,000 deaths globally. To fight against COVID-19, we carried out research for the near native SARS-CoV-2 and report here our preliminary results obtained. The pathogen of the COVID-19, the native SARS-CoV-2, was isolated, amplified and purified in a BSL-3 laboratory. The whole viral architecture of SARS-CoV-2 was examined by transmission electron microscopy (both negative staining and cryo-EM). We observed that the virion particles are roughly spherical or moderately pleiomorphic. Spikes have nail-like shape towards outside with a long body embedded in the envelope. The morphology of virion observed in our result indicates that the S protein of SARS-CoV-2 is in post-fusion state, with S1 disassociated. This state revealed by cryo-EM first time could provide an important information for the identification and relevant clinical research of this new coronavirus.

microbiology↗

bioRxiv2020

An In Vitro Vascularized Micro-Tumor Model of Human Colorectal Cancer Recapitulates In Vivo Drug Responses

Around 95% of anti-cancer drugs that show promise during preclinical study fail to gain FDA-approval for clinical use. This failure of the preclinical pipeline highlights the need for improved, physiologically-relevant in vitro models that can better serve as reliable drug-screening tools. The vascularized micro-tumor (VMT) is a novel three-dimensional model system that recapitulates the complex human tumor microenvironment, including perfused vasculature, within a transparent microfluidic device, allowing real-time study of drug responses and tumor-stromal interactions. Here we have validated the VMT platform for the study of colorectal cancer (CRC), the second leading cause of cancer-related deaths, by showing that gene expression, tumor heterogeneity, and treatment response in the VMT more closely model CRC tumor clinicopathology than current standard drug screening modalities, including 2-dimensional (2D) monolayer culture and 3-dimensional (3D) spheroids.

cancer biology↗

bioRxiv2020

Public broadly neutralizing antibodies against hepatitis B virus in individuals with elite serologic activity

SUMMARYAlthough there is no effective cure for chronic hepatitis B virus (HBV) infection, antibodies are protective and constitute clinical correlates of recovery from infection. To examine the human neutralizing antibody response to HBV in elite neutralizers we screened 144 individuals. The top individuals produced shared clones of broadly neutralizing antibodies (bNAbs) that targeted 3 non-overlapping epitopes on the HBV S antigen (HBsAg). Single bNAbs protected humanized mice against infection, but selected for resistance mutations in mice with established infection. In contrast, infection was controlled by a combination of bNAbs targeting non-overlapping epitopes with complementary sensitivity to mutations that commonly emerge during human infection. The co-crystal structure of one of the bNAbs with a peptide epitope containing residues frequently mutated in human immune escape variants revealed a loop anchored by oppositely charged residues. The structure provides a molecular explanation for why immunotherapy for HBV infection may require combinations of complementary bNAbs.

immunology↗

bioRxiv2020

A Novel Non-hypermucoviscous ST11 Hypervirulent Carbapenem-resistant Klebsiella pneumoniae Lacking Classical Virulence Factors

BackgroundHypervirulent Klebsiella pneumoniae lacking classical virulence factors is uncommon, and the virulence mechanisms of this organism are not understood. MethodsFollowing a retrospective study of carbapenem-resistant K. pneumoniae based on core genome multilocus sequence typing (cgMLST), isolates that caused high mortality were investigated with a genome-wide association study (GWAS), proteome analysis and an animal model. ResultsThe sublineage of sequence type 11 (ST11) K. pneumoniae, which belongs to complex type 3176 (CT3176) and K-locus 47 (KL47), was highlighted due to the high mortality of infected patients. GWAS analysis showed that ampR was associated with the CT3176 isolates. In a mouse model, the mortality of ampR-carrying isolates was comparable to that of the typical hypervirulent isolate GM2. Even during the first 24 hours of infection, the bacterial load and pathological changes of the ampR-carrying isolates in the lungs were more severe than those of GM2. The ampR complement mutant was able to enhance the virulence of the KL47 isolate but not the virulence of KL1. Proteome analysis showed that the expression of WcaJ in the ampR+ isolates was significantly higher than that in the ampR- isolates, and this result was also confirmed by transcription tests and capsule staining. It is suggested that the enhancement of the initial stage of capsule synthesis may be the cause of the high virulence of these non-hypermucoviscous ST11 carbapenem-resistant K. pneumoniae isolates. ConclusionsNon-hypermucoviscous ST11 hypervirulent carbapenem-resistant K. pneumoniae warrants continued surveillance and investigation.

microbiology↗

bioRxiv2020

Artesunate interacts with Vitamin D receptor to reverse mouse model of sepsis-induced immunosuppression via enhancing autophagy

Background and PurposeImmunosuppression is the predominant cause of mortality for sepsis due to failure to eradicate invading pathogens. Unfortunately, no effective and specific drugs capable of reversing immunosuppression are available for clinical use. Increasing evidence implicates vitamin D receptor (VDR) involved in sepsis-induced immunosuppression. Herein, artesunate (AS) was discovered to reverse sepsis-induced immunosuppression and its molecular mechanism is investigated. Experimental ApproachEffect of artesunate on sepsis-induced immunosuppression was investigated in mice and in vitro. VDR was predicted to be an interacted candidate of AS by bioinformatics predict, then identified using PCR and immunoblotting. VDR, ATG16L1 and NF-{kappa}B p65 were modified to investigate the alteration of ASs effect on pro-inflammatory cytokines release, bacteria clearance and autophagy activities in sepsis-induced immunosuppression. Key ResultsAS significantly reduced the mortality of cecal ligation and puncture (CLP)-induced sepsis immunosuppression mice challenged with Pseudomonas Aeruginosa, and enhanced proinflammatory cytokines release and bacterial clearance to reverse sepsis-induced immunosuppression in vivo and in vitro. Mechanically, AS interacted with VDR thereby inhibited the nuclear translocation of VDR, then influencing ATG16L1 transcription and subsequent autophagy activity. In addition, AS inhibited physical interaction between VDR and NF-{kappa}B p65 in LPS tolerance macrophages, then promoted nuclear translocation of NF-{kappa}B p65, which activated the transcription of NF-{kappa}B p65 target genes such as pro-inflammatory cytokines. Conclusion and ImplicationsOur findings provide an evidence that AS interacted with VDR to reverse sepsis-induced immunosuppression in an autophagy and NF-{kappa}B dependent way, highlighting a novel approach for sepsis treatment and drug repurposing of AS in the future.

pharmacology and toxicology↗

bioRxiv2020

Lack of dcf1 leads to neuronal migration delay, axonal swollen and autism-related deficits

Perturbed neuronal migration and abnormal axonogenesis have been shown to be implicated in the pathogenesis of autism spectrum disorder (ASD). However, the molecular mechanism remains unknown. Here we demonstrate that dendritic cell factor 1(DCF1) is involved in neuronal migration and axonogenesis. The deletion of dcf1 in mice delays the localization of callosal projection neurons, while dcf1 overexpression restores normal migration. Delayed neurons appear as axon swelling and axonal boutons loss, resulting in a permanent deficit in the callosal projections. Western blot analysis indicates that absence of dcf1 leads to the abnormal activation of ERK signal. Differential protein expression assay shows that PEBP1, a negative regulator of the ERK signal, is significant downregulation in dcf1 KO mice. Direct interaction between DCF1 and PEBP1 is confirmed by Co-immunoprecipitation test, thus indicating that DCF1 regulates the ERK signal in a PEBP1-dependent pattern. As a result of the neurodevelopmental migration disorder, dcf1 deletion results in ASD-like behaviors in mice. This finding identifies a link between abnormal activated ERK signaling, delayed neuronal migration and autistic-like behaviors in humans.

neuroscience↗

bioRxiv2020

Loss of rice PARAQUAT TOLERANCE 3 confers enhanced resistance to abiotic stresses and increases grain yield in field

Plants frequently suffer from environmental stresses in nature and have evolved sophisticated and efficient mechanisms to cope with the stresses. To balance between growth and stress response, plants are equipped with efficient means to switch off the activated stress responses when stresses diminish. We previously revealed such an off-switch mechanism conferred by Arabidopsis PQT3, knockout of which significantly enhances resistance to abiotic stresses. To explore whether the rice homolog OsPQT3 is functionally conserved, we generated three knockout mutants with CRISPR-Cas9 technology. The OsPQT3 knockout mutants (ospqt3) display enhanced resistance to oxidative and salt stress with elevated expression of OsGPX1, OsAPX1, and OsSOD1. More importantly, the ospqt3 mutants show significantly enhanced agronomic performance with higher yield compared with the wild type under salt stress in greenhouse as well as in field conditions. We further showed that OsPQT3 was rapidly down regulated in response to oxidative and other abiotic stresses as AtPQT3. Taken together, these results support our previous findings that AtPQT3 acts as an off-switch in stress response, which is well conserved in rice. Therefore, PQT3 locus provides a promising candidate for crop improvement with enhanced stress resistance by gene editing technology.

plant biology↗

bioRxiv2020

Rice NIN-LIKE PROTEIN 1 Rapidly Responds to Nitrogen Deficiency and Improves Yield and Nitrogen Use Efficiency

Nitrogen (N) is indispensable for crop growth and yield, but excessive agricultural application of nitrogenous fertilizers has generated severe environmental problems. A desirable and economical solution to cope with these issues is to improve crop nitrogen use efficiency (NUE). Plant NUE has been a focal point of intensive research worldwide, yet much more has to be learned about its genetic determinants and regulation. Here, we show that rice NIN-LIKE PROTEIN 1 (OsNLP1) plays a fundamental role in N utilization. OsNLP1 protein localizes in nucleus and its transcript level is rapidly induced by N starvation. Overexpression of OsNLP1 improves plant growth, grain yield and NUE under different N conditions while knockout of OsNLP1 impairs grain yield and NUE under N limiting conditions. OsNLP1 regulates nitrate and ammonium utilization by cooperatively orchestrating multiple N uptake and assimilation genes. Chromatin immunoprecipitation and yeast-one-hybrid assays show that OsNLP1 can directly bind to the promoter of these genes to activate their expression. Therefore, our results demonstrate that OsNLP1 is a key regulator of N utilization and represents a potential target for improving NUE and yield in rice. One-sentence summaryOsNLP1 rapidly responds to N availability, enhances N uptake and assimilation, and holds great potential in promoting high yield in rice.

plant biology↗

bioRxiv2020

The Neural Basis for a Persistent Internal State in Drosophila Females

Sustained changes in mood or action require persistent changes in neural activity, but it has been difficult to identify and characterize the neural circuit mechanisms that underlie persistent activity and contribute to long-lasting changes in behavior. Here, we focus on changes in the behavioral state of Drosophila females that persist for minutes following optogenetic activation of a single class of central brain neurons termed pC1. We find that female pC1 neurons drive a variety of persistent behaviors in the presence of males, including increased receptivity, shoving, and chasing. By reconstructing cells in a volume electron microscopic image of the female brain, we classify 7 different pC1 cell types and, using cell type specific driver lines, determine that one of these, pC1-Alpha, is responsible for driving persistent female shoving and chasing. Using calcium imaging, we locate sites of minutes-long persistent neural activity in the brain, which include pC1 neurons themselves. Finally, we exhaustively reconstruct all synaptic partners of a single pC1-Alpha neuron, and find recurrent connectivity that could support the persistent neural activity. Our work thus links minutes-long persistent changes in behavior with persistent neural activity and recurrent circuit architecture in the female brain.

neuroscience↗

bioRxiv2020

ATG8-interacting (ATI) 1 and 2 define a plant starvation-induced ER-phagy pathway and serve as MSBP1 (MAPR5) cargo-receptors

ER-phagy, the selective autophagy of endoplasmic reticulum (ER) components, is known to operate in eukaryotes from yeast and unicellular algae to animals and plants. Thus far, only ER-stress derived ER-phagy was reported and analyzed in plants. In this study we characterize an ER-phagy pathway in Arabidopsis thaliana that is triggered by dark-induced starvation and not by ER-stress. This pathway is defined by the previously reported ATG8-interacting proteins, ATI1 and ATI2 and is regulated by the TOR signaling pathway. We further identified ER-localized Membrane Steroid Binding Protein 1 (MSBP1) as an ATI1 and 2 interacting protein and an autophagy cargo, and show that ATI1 and 2 serve as its cargo receptors. Together, these findings expand our knowledge on plants responses during energy deprivation and highlight the role of this special type of ER-phagy in this process.

plant biology↗

bioRxiv2020

Finding new cancer epigenetic and genetic biomarkers from cell-free DNA by combining SALP-seq and machine learning：esophageal cancer as an example

BackgroundCancer is an important public health problem worldwide and its early diagnosis and effective prognosis are critical for its treatment. In recent years, as a good material for cancer liquid biopsy, plasma cell-free DNA (cfDNA) has been widely analyzed by next generation sequencing (NGS) for finding new molecular markers for cancer diagnosis such as size, methylation and end coordinate. However, the current studies did not still involve esophageal cancer (ESCA), a main cancer that seriously threatens human health and life in China. Here we therefore tried to find new biomarkers for this cancer from cfDNA. Materials & methodsThirty cfDNA samples from 26 ESCA patients and 4 healthy people were used to construct the NGS libraries and sequenced by using SALP-seq. The sequencing data were analyzed with variant bioinformatics methods for finding ESCA molecular biomarkers. Results & conclusionWe identified 103 epigenetic markers (including 54 genome-wide and 49 promoter markers) and 37 genetic markers for ESCA. These markers provide new molecular biomarkers for ESCA diagnosis, prognosis and therapy. Importantly, this study provides a new pipeline for finding new molecular markers for cancers from cfDNA by combining SALP-seq and machine learning. Finally, by finding new molecular markers for ESCA from cfDNA, this study sheds important new insights on the clinical worth of cfDNA.

cancer biology↗

bioRxiv2020

Rice NIN-LIKE PROTEIN 4 is a master regulator of nitrogen use efficiency

Nitrogen (N) is one of the key essential macronutrients that affects rice growth and yield. Inorganic N fertilizers are excessively used to boost yield and generate serious collateral environmental pollution. Therefore, improving crop N use efficiency (NUE) is highly desirable and has been a major endeavor in crop improvement. However, only a few regulators have been identified that can be used to improve NUE in rice to date. Here we show that the NIN-like protein OsNLP4 significantly improves the rice NUE and yield. Field trials consistently showed that loss-of-OsNLP4 dramatically reduced yield and NUE compared with wild type under different N regimes. In contrast, the OsNLP4 overexpression lines remarkably increased yield by 30% and NUE by 47% under moderate N level compared with wild type. Transcriptomic analyses revealed that OsNLP4 orchestrates the expression of a majority of known N uptake, assimilation and signaling genes by directly binding to the nitrate-responsive cis-element in their promoters to regulate their expression. Moreover, overexpression of OsNLP4 can recover the phenotype of Arabidopsis nlp7 mutant and enhance its biomass. Our results demonstrate that OsNLP4 is a master regulator of NUE in rice and sheds light on crop NUE improvement.

plant biology↗

bioRxiv2020

A Connectivity-based Psychometric Prediction Framework for Brain-behavior Relationship Studies

The recent availability of population-based studies with neuroimaging and behavioral measurements opens promising perspectives to investigate the relationships between interindividual variability in brain regions connectivity and behavioral phenotypes. However, the multivariate nature of connectivity-based prediction model severely limits the insight into brain-behavior patterns for neuroscience. To address this issue, we propose a connectivity-based psychometric prediction framework based on individual regions connectivity profiles. We first illustrate two main applications: 1) single brain regions predictive power for a range of psychometric variables, and 2) single psychometric variables predictive power variation across brain region. We compare the patterns of brain-behavior provided by these approaches to the brain-behavior relationships from activation approaches. Then, capitalizing on the increased transparency of our approach, we demonstrate how the influence of various data processing and analyses can directly influence the patterns of brain-behavior relationships, as well as the unique insight into brain-behavior relationships offered by this approach.

neuroscience↗

bioRxiv2020

MicroRNA-574 Regulates FAM210A Expression and Influences Pathological Cardiac Remodeling

Aberrant synthesis of mitochondrial proteins impairs cardiac function and causes heart disease. However, the mechanism of regulation of mitochondria encoded protein expression during cardiac disease remains underexplored. Here, we have shown that multiple pathogenic cardiac stressors induce the expression of miR-574 guide and passenger strands (miR-574-5p/3p) in both humans and mice. miR-574 knockout mice exhibit severe cardiac disorder under heart disease-triggering stresses. miR-574-5p/3p mimics that are delivered systematically using nanoparticles reduce cardiac pathogenesis under disease insults. Transcriptome analysis of miR-574-null hearts uncovers FAM210A as a common target mRNA for both strands of miR-574. The interactome capture and translational state analyses suggest that FAM210A interacts with mitochondrial translation factors and regulates the protein expression of mitochondrial encoded electron transport chain genes. Using a human cardiomyocyte cell culture system, we discover that miR-574 regulates FAM210A expression and modulates mitochondrial encoded protein expression, which influences cardiac remodeling in heart failure.

pathology↗

bioRxiv2020

Circadian Rhythm Is Disrupted by ZNF704 in Breast Carcinogenesis

Copy number gain in chromosome 8q21 is considered as the prototype of genetic abnormalities associated with development of breast cancer, yet the oncogenic potential underlying this amplicon in breast carcinogenesis remains to be delineated. We report here that ZNF704, a gene mapped to 8q21, is recurrently amplified in various malignancies including breast cancer. We found that ZNF704 acts as transcription repressor and interacts with the transcription corepressor SIN3A complex. Genome-wide interrogation of the transcriptional targets identifies that the ZNF704/SIN3A complex represses a panel of genes including PER2 that are critically involved in the function of circadian clock. Indeed, ZNF704 overexpression prolongs the period and dampens the amplitude of circadian clock. We showed that ZNF704 promotes the proliferation and invasion of breast cancer cells in vitro and accelerates the growth and metastasis of breast cancer in vivo. Consistently, the level of ZNF704 expression is inversely correlated with that of PER2 in breast carcinomas, and high level of ZNF704 correlates with advanced histological grades, lymph node positivity, and poor prognosis of breast cancer patients, especially those with HER2+ and basal-like subtypes. These results indicate that ZNF704 is an important regulator of circadian clock and a potential driver for breast carcinogenesis.

cancer biology↗