Biology subjects

Wu, Q.

Publications and source records attributed to Wu, Q..

At least 289 records · Page 16Linked to original sources

bioRxiv2019

Tandem Directional CTCF Sites Balance Protocadherin Promoter Usage

CTCF is a key insulator-binding protein and mammalian genomes contain numerous CTCF-binding sites (CBSs), many of which are organized in tandem arrays. Here we provide direct evidence that CBSs, if located between enhancers and promoters in the Pcdh and {beta}-globin clusters, function as an enhancer-blocking insulator by forming distinct directional chromatin loops, regardless whether enhancers contain CBS or not. Moreover, computational simulation and experimental capture revealed balanced promoter usage in cell populations and stochastic monoallelic expression in single cells by large arrays of tandem variable CBSs. Finally, gene expression levels are negatively correlated with CBS insulators located between enhancers and promoters on a genome-wide scale. Thus, single CBS insulators ensure proper enhancer insulation and promoter activation while tandem-arrayed CBS insulators determine balanced promoter usage. This finding has interesting implications on the role of topological insulators in 3D genome folding and developmental gene regulation.

molecular biology↗

bioRxiv2019

IFITM3 protects the heart during influenza virus infection

Influenza virus primarily targets the lungs, but dissemination and damage to heart tissue is also known to occur in severe infections. Despite this knowledge, influenza virus-induced cardiac pathogenesis and its underlying mechanisms have been difficult to study due to a lack of small animal models. In humans, polymorphisms in the gene encoding interferon-induced transmembrane protein 3 (IFITM3), an antiviral restriction factor, are associated with susceptibility to severe influenza, but whether IFITM3 deficiencies contribute to other aspects of pathogenesis, including cardiac dysfunction, is unknown. We now show that IFITM3 deficiency in a newly generated knockout (KO) mouse model exacerbates illness and mortality following influenza A virus infection. Enhanced pathogenesis correlated with increased replication of virus in the lungs, spleens, and hearts of KO mice relative to wildtype (WT) mice. IFITM3 KO mice exhibited normal cardiac function at baseline, but developed severely aberrant electrical activity upon infection, including decreased heart rate and irregular, arrhythmic RR (interbeat) intervals. In contrast, WT mice exhibited a mild decrease in heart rate without irregularity of RR intervals. Heightened cardiac virus titers and electrical dysfunction in KO animals was accompanied by increased activation of fibrotic pathways and fibrotic lesions in the heart. Our findings reveal an essential role for IFITM3 in controlling influenza virus replication and pathogenesis in heart tissue and establish IFITM3 KO mice as a powerful model to study virus-induced cardiac dysfunction.

immunology↗

bioRxiv2019

Construction of synthetic microbiota for reproducible flavor metabolism in Chinese light aroma type liquor produced by solid-state fermentation

Natural microbiota plays an essential role in flavor compounds producing for traditional food fermentation. Whereas, the fluctuation of natural microbiota results in the inconstancy of food quality. Thus, it is critical to reveal the core microbiota for flavor compounds producing and construct a synthetic core microbiota for constant food fermentation. Here, we revealed the core microbiota based on their flavor-producing and co-occurrence performance, using Chinese light aroma type liquor as a model system. Five genera were identified to be the core microbiota, including Lactobacillus, Saccharomyces, Pichia, Geotrichum, and Candida. The synthetic core microbiota of these five genera presented a reproducible dynamic profile with that in the natural microbiota. Monte Carlo test showed that the interpretation of five environmental factors (lactic acid, ethanol and acetic acid contents, moisture and pH) on the synthetic microbiota distribution were highly significant (P < 0.01), which was similar with that in the natural fermentation system. In addition, 77.27% of the flavor compounds produced by the synthetic core microbiota showed a similar dynamic profile ({rho} > 0) with that in the natural liquor fermentation process, and the flavor profile presented a similar composition. It indicated that the synthetic core microbiota is efficient for reproducible flavor metabolism. This work established a method for identifying core microbiota and constructing a synthetic microbiota for reproducible flavor compounds. It is of great significance for the tractable and constant production of various fermented foods.\n\nIMPORTANCEThe transformation from natural fermentation to synthetic fermentation is essential to construct a constant food fermentation process, which is the premise for stably making high-quality food. According to the functions of flavor-producing and co-occurring in dominant microbes, we provided a system-level approach to identify the core microbiota in Chinese light aroma type liquor fermentation. In addition, we successfully constructed a synthetic core microbiota to simulate the microbial community succession and flavor compounds production in the in vitro system. The constructed synthetic core microbiota could not only facilitate a mechanistic understanding of the structure and function of the microbiota, but also be beneficial for constructing a tractable and reproducible food fermentation process.

microbiology↗

bioRxiv2018

Somatic LINE-1 retrotransposition in cortical neurons of Rett patients and healthy individuals

Mounting evidence supports that LINE-1 (L1) retrotransposition can occur postzygotically in healthy and diseased human tissues, contributing to genomic mosaicism in the brain and other somatic tissues of an individual. However, the genomic distribution of somatic L1Hs (Human-specific LINE-1) insertions and their potential impact on carrier cells remain unclear. Here, using a PCR-based targeted bulk sequencing approach, we profiled 9,181 somatic insertions from 20 postmortem tissues from five Rett patients and their matched healthy controls. We identified and validated somatic L1Hs insertions in both cortical neurons and non-brain tissues. In Rett patients, somatic insertions were significantly depleted in exons--mainly contributed by long genes--than healthy controls, implying that cells carrying MECP2 mutations might be defenseless against a second exonic L1Hs insertion. We observed a significant increase of somatic L1Hs insertions in the brain compared with non-brain tissues from the same individual. Compared to germline insertions, somatic insertions were less sense-depleted to transcripts, indicating that they underwent weaker selective pressure on the orientation of insertion. Our observations demonstrate that somatic L1Hs insertions contribute to genomic diversity and MECP2 dysfunction alters their genomic patterns in Rett patients. Author SummaryHuman-specific LINE-1 (L1Hs) is the most active autonomous retrotransposon family in the human genome. Mounting evidence supports that L1Hs retrotransposition occurs postzygotically in the human brain cells, contributing to neuronal genomic diversity, but the extent of L1Hs-driven mosaicism in the brain is debated. In this study, we profiled genome-wide L1Hs insertions among 20 postmortem tissues from Rett patients and matched controls. We identified and validated somatic L1Hs insertions in both cortical neurons and non-brain tissues, with a higher jumping activity in the brain. We further found that MECP2 dysfunction might alter the genomic pattern of somatic L1Hs in Rett patients.

genomics↗

bioRxiv2018

A novel polyphasic identification system for genus Trichoderma

As the rapid-changing in Trichoderma taxonomy, an efficient identification of Trichoderma species is an urgent issue for Trichoderma-based research. In this study, based on the current taxonomy of Trichoderma, we constructed curated databases including 338 ITS sequences, 435 TEF1 sequences, 415 RPB2 sequences and 28 phenotypic characters. In addition, a polyphasic identification system (PIST) was developed. Within PIST, the resolution ability of molecular and phenotype characters could be combined for species identification in a step-by-step way. Compared with other identification systems, the involved Trichoderma species were extended from 88 to 252 species and 175 from 188 tested Trichoderma species could be identified within PIST. In most tested cases, three nucleotide markers and phenotypic characters showed improved identification performance. The TEF1 sequences have superior resolution than other characters.\n\nImportanceThe genus Trichoderma is important to human society with a wide application in industry, agriculture and environment bio-remediation. Thus, a quick and accurate identification of Trichoderma spp. is paramount since it is usually the first step to conduct a Trichoderma-based scientific research and is an obstruction especially for those researchers as nematologist, chemists, nutritionist and the like, lacking of taxonomic knowledge of fungi.

microbiology↗

bioRxiv2018

Comparative transcriptome and proteome profiling of the chlorophyll metabolism pathway in four cultivars of Magnolia officinalis

Magnolia officinalis is an important herb in Chinese medicine that has good therapeutic effects on gastrointestinal motility and helps regulate the spleen and stomach. Magnolia officinalis Rehd.et Wils. (abbreviated as CH) Magnolia officinalis Rehd.et Wils. var. biloba DaAoye (abbreviated as DA) Magnolia officinalis Rehd.et Wils. var. biloba XiaoAoye (abbreviated as XA)Magnolia officinalis Rehd.et Wils. var. biloba Liuye (abbreviated as LY) are the four main cultivars in Dujiangyan city, Sichuan province in China, and DA has better medicinal effects and higher levels of green pigment than the other three cultivars. Proteomics research not only provides new insights into protein expression patterns but also enables the identification of many attractive candidates for further research on the effects of pesticides on chlorophyll metabolism in Magnolia officinalis. Transcriptome and proteome analysis of the four main Magnolia officinalis cultivars in Sichuan province in China identified 125,100 unigenes and 6,012 proteins. Proteomic data and parallel reaction monitoring (PRM) revealed that porphobilinogen deaminase, uroporphyrinogen decarboxylase, oxygen-dependent coproporphyrinogen-III oxidase, protoporphyrinogen oxidase 1, magnesium protoporphyrin IX methyltransferase, magnesium-protoporphyrin IX monomethyl ester oxidative cyclase, and protochlorophyllide reductase-like protein, all of which are involved in chlorophyll synthesis, have higher expression levels in DA than in the other three cultivars. This finding is consistent with the observation that DA has the highest concentration of chlorophyll (37.56 mg/g Fw) of the four cultivars. This research is beneficial to the understanding of the differences in the growth of the four cultivars on the molecular level.

bioinformatics↗

bioRxiv2018

Anterior insular cortex plays a critical role in interoceptive attention

Although accumulating evidence indicates that the anterior insular cortex (AIC) mediates interoceptive attention, which refers the attention towards physiological signals arising from the body, the necessity of the AIC in this process has not been demonstrated. Using a novel task that directs attention toward breathing rhythm, we assessed the involvement of the AIC in interoceptive attention in healthy participants using functional magnetic resonance imaging and examined the necessity of the AIC in interoceptive attention in patients with AIC lesions. We found that interoceptive attention was associated with greater AIC activation, as well as enhanced coupling between the AIC and somatosensory area along with reduced coupling between AIC and visual sensory areas. AIC activation and connectivity were predictive of individual differences in interoceptive accuracy. Importantly, AIC lesion patients showed disrupted interoceptive discrimination accuracy and sensitivity. Together, these results provide compelling evidence that AIC plays a critical role in interoceptive attention.

neuroscience↗

bioRxiv2018

A Whole-Genome Association Approach for Large-scaled Inter-species Trait

Genome wide association studies (GWAS) have provided an avenue for the association between common genetic variants and complex traits. However, using SNP as a genetic marker, GWAS has been confined to detect genetic basis traits only for within species but not for the large-scale inter-species traits. Here, we propose a practical statistical approach that is using kmer frequencies as the genetic markers to associate genetic variants with large scale inter-species traits. We applied this new approach to the trait of chromosome number in 96 mammalian proteomes, and we prioritized 130 genes including TP53 and BAD, of which 6 were candidate genes. These genes were proved to be associated with cellular reaction of DNA double-strand breaks caused by chromosome fission/fusion. Our study provides a new effective genomic strategy to perform association studies for large-scaled inter-species traits, using the chromosome number as a case. We hope this approach could provide exploration for broadly widely traits.

genomics↗

bioRxiv2018

Human neurons from Christianson syndrome iPSCs reveal allele-specific responses to rescue strategies

Human genetic disorders provide a powerful lens to understanding the human brain. Induced pluripotent stem cells (iPSC) represent an important, new resource for mechanistic studies and therapeutic development. Christianson syndrome (CS), an X-linked neurological disorder with attenuation of brain growth postnatally (postnatal microcephaly), is caused by mutations in SLC9A6, the gene encoding endosomal Na+/H+ exchanger 6 (NHE6). We developed CS iPSC lines from patients with a mutational spectrum, as well as robust biologically-related and isogenic controls. We demonstrate that mutations in CS lead to loss of protein function by a variety of mechanisms. Regardless of mutation, all patient-derived neurons demonstrate reduced neurite growth and arborization, likely underlying diminished postnatal brain growth in patients. Additionally, phenotype rescue strategies show allele-specific responses: a gene replacement strategy shows efficacy in nonsense mutations but not in a missense mutation, whereas application of exogenous trophic factors (BDNF or IGF-1) rescues arborization phenotypes across all mutations. Our data emphasize the important principle of personalized medicine whereby success of some therapeutic strategies may be more linked to patient genotype than others.

neuroscience↗

bioRxiv2018

Single-cell RNA-seq analysis maps the development of human fetal retina

Vision starts with image formation at the retina, which contains diverse neuronal cell types that extract, process, and relay visual information to higher order processing centers in the brain. Though there has been steady progress in defining retinal cell types, very little is known about retinal development in humans, which starts well before birth. In this study, we performed transcriptomic profiling of developing human fetal retina from gestational weeks 12 to 27 using single-cell RNA-seq (scRNA-seq) and used pseudotime analysis to reconstruct the developmental trajectories of retinogenesis. Our analysis reveals transcriptional programs driving differentiation down four different cell types and suggests that Muller glia (MG) can serve as embryonic progenitors in early retinal development. In addition, we also show that transcriptional differences separate retinal progenitor cells (RPCs) into distinct subtypes and use this information to reconstruct RPC developmental trajectories and cell fate. Our results support a hierarchical program of differentiation governing cell-type diversity in the developing human retina. In summary, our work details comprehensive molecular classification of retinal cells, reconstructs their relationships, and paves the way for future mechanistic studies on the impact of gene regulation upon human retinogenesis.

neuroscience↗

bioRxiv2018

Wnt/Fgf crosstalk is required for the specification of tracheal basal progenitor cells

Basal progenitor cells are critical for the establishment and maintenance of the tracheal epithelium. However, it remains unclear how these progenitor cells are specified during foregut development. Here, we found that ablation of the Wnt chaperon protein Gpr177 (also known as Wntless) in the epithelium causes significant reduction in the numbers of basal progenitor cells accompanied by cartilage loss in Shh-Cre;Gpr177loxp/loxp mutants. Consistent with the association between cartilage and basal cell development, Nkx2.1+p63+ basal cells are co-present with cartilage nodules in Shh-Cre;Ctnnb1DM/loxp mutants which keep partial cell-cell adhesion but not the transcription regulation function of {beta}-catenin. More importantly, deletion of Ctnnb1 in the mesenchyme leads to the loss of basal cells and cartilage concomitant with the reduced transcript levels of Fgf10 in Dermo1-Cre;Ctnnb1loxp/loxp mutants. Furthermore, deletion of Fgf receptor 2 (Fgfr2) in the epithelium also leads to significantly reduced numbers of basal cells, supporting the importance of the Wnt/Fgf crosstalk in early tracheal development.

developmental biology↗

bioRxiv2018

Metformin Intervention Prevents Cardiac Dysfunction in a Murine Model of Adult Congenital Heart Disease

Congenital heart disease (CHD) is the most frequent birth defect worldwide and the number of adult patients with CHD, now referred to as ACHD, is increasing. However the mechanisms whereby ACHD predisposes patients to heart dysfunction are still unclear. ACHD is strongly associated with metabolic syndrome, but how ACHD interacts with poor modern lifestyle choices and other comorbidities, such as hypertension, obesity and diabetes, is mostly unknown. Using a genetic mouse model of ACHD we showed that ACHD mice placed under metabolic stress (high fat diet) displayed decreased heart function. Comprehensive physiological, biochemical and molecular analysis showed that ACHD hearts exhibited early changes in energy metabolism that preceded cardiac dysfunction. Restoration of metabolic balance by metformin prevented the development of heart dysfunction in ACHD mice. This study reveals that early metabolic impairment reinforces heart dysfunction in ACHD predisposed individuals and diet or pharmacological interventions can be used to modulate heart function and attenuate heart failure and may be an important avenue for intervention in ACHD.

genetics↗

bioRxiv2018

A Chemical Toolbox for the Study of Bromodomains and Epigenetic Signaling

Bromodomains (BRDs) are evolutionary conserved epigenetic protein interaction modules which recognize (\"read\") acetyl-lysine, however their role(s) in regulating cellular states and their potential as targets for the development of targeted treatment strategies is poorly understood. Here we present a set of 25 chemical probes, selective tool small molecule inhibitors, covering 29 human bromodomain targets. We comprehensively evaluate the selectivity of this probe-set using BROMOscan(R) and demonstrate the utility of the set using studies of muscle cell differentiation and triple negative breast cancer (TNBC). We identified cross talk between histone acetylation and the glycolytic pathway resulting in a vulnerability of TNBC cell lines to inhibition of BRPF2/3 BRDs under conditions of glucose deprivation or GLUT1 inhibition. This chemical probe set will serve as a resource for future applications in the discovery of new physiological roles of bromodomain proteins in normal and disease states, and as a toolset for bromodomain target validation.

cell biology↗

bioRxiv2018

Functional In vivo Single-cell Transcriptome (FIST) Analysis Reveals Molecular Properties of Light-Sensitive Neurons in Mouse V1

Vision formation is classically based on projections from the retinal ganglion cells (RGC) to the lateral geniculate nucleus (LGN) and the primary visual cortex (V1). Although the cellular information of the retina and the LGN has been widely studied, the transcriptome profiles of single neurons with specific functions in V1 still remain unknown. Some neurons in mouse V1 are tuned to light stimulus. To determine the molecular properties of light-stimulated neurons in layer 2/3 of V1, we developed a method of functional in vivo single-cell transcriptome (FIST) analysis that integrates sensory evoked calcium imaging, whole-cell electrophysiological patch-clamp recordings, single-cell mRNA sequencing and three-dimensional morphological characterization in a live mouse, based on a two-photon microscope system. In our study, 58 individual cells from layer 2/3 of V1 were identified as either light-sensitive (LS) or non-light-sensitive (NS) by single-cell light-evoked calcium evaluation and action potential spiking. The contents of every single cell after individual functional tests were aspirated through the patch-clamp pipette for mRNA sequencing. Furthermore, the three-dimensional (3-D) morphological characterizations of the neurons were reconstructed in the live mouse after the whole-cell recordings. Our sequencing results indicated that V1 neurons with high expression of genes related to transmission regulation, such as Rtn4r, Nr4a1, and genes involved in membrane transport, such as Na+/K+ ATPase, NMDA-type glutamatergic receptor, preferentially respond to light stimulation. Our findings demonstrate the ability of FIST analysis to characterize the functional, morphological and transcriptomic properties of a single cell in alive animal, thereby providing precise neuronal information and predicting its network contribution in the brain.

neuroscience↗

bioRxiv2018

Altered microRNA expression profles are involved in Storage Lesions of Apheresis Platelet

Although platelet is anucleate cell, it contains a large amount miRNAs. This study aims to explore the relationship between miRNAs expression profles and platelets function, as well as miRNAs potential roles during platelet storage lesions. Platelets were collected from 15 healthy men with O blood types. MiRNAs profiles in platelets were detected by Agilent Human miRNA Array Differential miRNA levels were studied using human platelets after apheresis and stored for 2, 5 and 8 days using microarray. There were 167 and 230 altered miRNAs during the 5 and 8 day storage, respectively. In addition, the number of reduced miRNAs was much greater than that of increased. And many of them are involved in functions of platelet activation, degranulation, PDGF receptor signaling pathway and cell differentiation. The results of RT-PCR showed that the expression of miR-21-5p, miR-21-3p and miR-155 decreased on the 5th day, while miR-223, miR-3162 and let-7b increased. Flow cytometry results revealed that with increase of storage time, the expression of P2Y12 increased and phosphorylation level of VASP reduced. Meanwhile, the platelet reactivity index (PRI) decreased from 72.7% to 18.2%, while the apoptotic percentage of platelet significantly increased. For the first time, we found altered miRNAs are closely related to platelet aggregation, including P2Y12, VASP and GPb/a. Through KEGG database prediction, we verified there were many miRNAs impacting the pathway of platelet aggregation, such as miR-223, miR-21 and let-7b, which indicated miRNAs might serve as potential biomarkers of storage lesion in platelet. These target miRNAs are related to activation, degranulation and PDGF receptor signaling pathway of platelet.

molecular biology↗

bioRxiv2018

The Enzymes that beyond Non-Oxidative Glycolysis

High yield is an important objective of cell factory. One or several genes cloned into the bacterial may make the synthetic pathway much more optimal, so can increase the yield. But the global benefit enzymes are rare, which can increase the yields of many chemical products for a cell factory such as E.coli. Two of these kinds of global benefit enzymes are the famous enzymes, D-fructose-6-phosphate D-erythrose-4-phosphate-lyase and D-Xylulose 5-phosphate D-glyceraldehyde-3-phosphate-lyase, of non-oxidative glycolysis (NOG) published in Nature, which can improve the utilization ratio of carbon. We expect to find other global benefit enzymes. We use an integrated model, which integrated in silico model of E.coli and KEGG. By computation, we analyze the effect of adding each reaction from KEGG on the theoretical yields of several products with E.coli and find 83 enzymes that may be potentially global benefit enzymes. By comparison, we find about 30 of the 83 enzymes are better in improving the theoretical yields than the two enzymes of NOG.\n\nIn order to compare the global benefit enzymes with NOG, as an example, we select \"Glycerol:NADP+ oxidoreductase\" (GNO) which can increase the supply of NADPH in E.coli. But To increase the supply of reducing power, such as NADPH will probably increase the yield of chemicals in a cell factory. We use flux balance analysis method to testify our assumption. By comparing the maximum yields of 80 products produced by E.coli with respectively using GNO and NOG, we find GNO has better performance in the product production of E.coli. So GNO is a global benefit enzyme which can increase the yields of many chemical products in E.coli.

synthetic biology↗

bioRxiv2018

Dissecting PCNA function with a systematically designed mutation library in yeast

Proliferating cell nuclear antigen (PCNA), encoded by POL30 in Saccharomyces cerevisiae, is a key component of DNA metabolism. Here a library consisting of 308 PCNA mutants was designed and synthesized to probe the contribution of each residue to its biological function. Five regions were identified with elevated sensitivity to DNA damaging reagents using high-throughput phenotype screening. Using a series of genetic and biochemical analyses, we demonstrated that one particular mutant, K168A, which displayed severe DNA damage sensitivity, abolished the DNA damage tolerance (DDT) pathway by disrupting interactions between PCNA and Rad5p. Subsequent domain analysis showed that the PCNA/Rad5p interaction is prerequisite for the function of Rad5p in DDT. Our study not only provides a resource in the form of a library of versatile mutants to study PCNA functions, but also reveals a key regulatory function of Rad5p, which highlights the importance of the PCNA-Rad5p interaction.\n\nAuthor summaryPCNA is regarded as the maestro of DNA replication fork because of the astonishing ability to interact with lots of partner proteins that participate in various DNA metabolism processes. However, it has remained elusive as to how does PCNA orchestrate these functions in harmony. Here, we constructed a systematic mutation library of PCNA, which covers every amino acid to map the functional sites of it. This carefully designed synthetic mutant pool could be generally useful and serve as a flexible resource, such as dissecting the functional mechanism of PCNA by genetic relationship analysis with key proteins through Synthetic genetic array. We further dissected the intrinsic mechanism for damage sensitivity of PCNAK168A, the most severe DNA damage sensitive mutant in our alanine scanning mutation library, this helps us to get better understanding of how PCNA participates in DNA damage tolerance (DDT) pathways. Our findings indicate that K168 site is vital for the interaction between DDT related partner proteins and PCNA, and also highlight the importance of the PCNA-Rad5p interaction.

genetics↗

bioRxiv2018

BAP1 deubiquitinase is a potent repressor of fetal hemoglobin biosynthesis

Human globin gene production transcriptionally \"switches\" from fetal to adult synthesis shortly after birth, and is controlled by macromolecular complexes that enhance or suppress transcription by cis-elements scattered throughout the locus. The DRED repressor is recruited to the {varepsilon}- and {gamma}-globin promoters by the orphan nuclear receptors TR2 (NR2C1) and TR4 (NR2C2) to engender their silencing in adult erythroid cells. Here we found that nuclear receptor corepressor-1 (NCoR1) is a critical component of DRED that acts as a scaffold to unite the DNA binding and epigenetic enzyme components (e.g. DNMT1 and LSD1) that elicit DRED function. We also describe a potent new regulator of {gamma}-globin repression: the deubiquitinase BAP1 is a component of the repressor complex whose activity maintains NCoR1 at sites in the {beta}-globin locus, and BAP1 inhibition in erythroid cells massively induces {gamma}-globin synthesis. These data provide new mechanistic insights through the discovery of novel epigenetic enzymes that mediate {gamma}-globin gene repression.

developmental biology↗