Biology subjects

Guo, Q.

Publications and source records attributed to Guo, Q..

At least 127 records · Page 7Linked to original sources

bioRxiv2021

The transcription factor Zeb2 drives differentiation of age-associated B cells

Age-associated B-cells (ABCs) accumulate during infection, aging and autoimmunity, contributing to lupus pathogenesis. Here, we screen for transcription factors driving ABC formation and find Zeb2 is required for human and mouse ABC differentiation in-vitro. ABCs are reduced in ZEB2 haploinsufficient individuals and in mice lacking Zeb2 in B-cells. In mice with TLR7-driven lupus, Zeb2 is essential for ABC formation and autoimmune pathology. Zeb2 binds to the +20kb intronic enhancer of Mef2b, repressing Mef2b-mediated germinal center B-cell differentiation and promoting ABC formation. Zeb2 also targets genes important for ABC specification and function including Itgax. Zeb2-driven ABC differentiation requires Jak-Stat signaling, and treatment with the Jak1/3 inhibitor tofacitinib reduces ABC accumulation in autoimmune mice and patients. Zeb2 thus emerges as a driver of B-cell autoimmunity. One-Sentence SummaryZeb2 is essential for Age-associated B cells differentiation and function.

immunology↗

bioRxiv2021

A novel SERPINE1-FOSB fusion gene in a case of pseudomyogenic hemangioendothelioma results in activation of intact FOSB and the PI3K-AKT-mTOR signaling pathway and responsiveness to sirolimus

Pseudomyogenic hemangioendothelioma (PHE) is an extremely rare disease that affects mainly the young and more men than women. PHE are multicentric, locally aggressive, have low metastatic potential, and affect multiple tissue planes. Genetic aberrations are frequently detected in PHE and may play important roles in the occurrence, development, and treatment of this disease. In this study, we report a case of PHE with a novel SERPINE1-FOSB fusion gene. The fusion introduced a strong promoter near the coding region of FOSB, resulting in overexpression of intact FOSB. Immunohistochemical analysis showed overexpression of pAKT and mTOR in tumor cells, suggesting activation of the PI3K-AKT-mTOR signaling pathway. The patient responded well to targeted therapy with sirolimus, an mTOR inhibitor. Our study correlated dysregulation of a specific signaling pathway and the effectiveness of a targeted therapy to a specific genetic aberration. This information may be useful for future investigations of targeted therapeutics and provide a potential predictive biomarker for therapeutic effectiveness in cases of PHE with this genetic aberration.

genetics↗

bioRxiv2021

Rapid characterization of spike variants via mammalian cell surface display

The SARS-CoV-2 spike (S) protein is a critical component of subunit vaccines and a target for neutralizing antibodies. Spike is also undergoing immunogenic selection with clinical variants that increase infectivity and partially escape convalescent plasma. Here, we describe spike display, a high-throughput platform to rapidly characterize glycosylated spike ectodomains across multiple coronavirus-family proteins. We assayed [~]200 variant SARS-CoV-2 spikes for their expression, ACE2 binding, and recognition by thirteen neutralizing antibodies (nAbs). An alanine scan of all five N-terminal domain (NTD) loops highlights a public class of epitopes in the N1, N3, and N5 loops that are recognized by most of the NTD-binding nAbs. Some clinical NTD substitutions abrogate binding to these epitopes but are circulating at low frequencies around the globe. NTD mutations in variants of concern B.1.1.7 (United Kingdom), B.1.351 (South Africa), B.1.1.248 (Brazil), and B.1.427/B.1.429 (California) impact spike expression and escape most NTD-targeting nAbs. However, two classes of NTD nAbs still bind B.1.1.7 spikes and neutralize in pseudoviral assays. B.1.351 and B.1.1.248 include compensatory mutations that either increase spike expression or increase ACE2 binding affinity. Finally, B.1.351 and B.1.1.248 completely escape a potent ACE2 peptide mimic. We anticipate that spike display will accelerate antigen design, deep scanning mutagenesis, and antibody epitope mapping for SARS-CoV-2 and other emerging viral threats.

biochemistry↗

bioRxiv2021

Predicting hosts based on early SARS-CoV-2 samples and analyzing later world-wide pandemic in 2020

The SARS-CoV-2 pandemic has raised the concern for identifying hosts of the virus since the early-stage outbreak. To address this problem, we proposed a deep learning method, DeepHoF, based on extracting the viral genomic features automatically, to predict host likelihood scores on five host types, including plant, germ, invertebrate, non-human vertebrate and human, for novel viruses. DeepHoF made up for the lack of an accurate tool applicable to any novel virus and overcame the limitation of the sequence similarity-based methods, reaching a satisfactory AUC of 0.987 on the five-classification. Additionally, to fill the gap in the efficient inference of host species for SARS-CoV-2 using existed tools, we conducted a deep analysis on the host likelihood profile calculated by DeepHoF. Using the isolates sequenced in the earliest stage of COVID-19, we inferred minks, bats, dogs and cats were potential hosts of SARS-CoV-2, while minks might be one of the most noteworthy hosts. Several genes of SARS-CoV-2 demonstrated their significance in determining the host range. Furthermore, the large-scale genome analysis, based on DeepHoFs computation for the later world-wide pandemic in 2020, disclosed the uniformity of host range among SARS-CoV-2 samples and the strong association of SARS-CoV-2 between humans and minks.

bioinformatics↗

bioRxiv2021

Gel-like inclusions of C-terminal fragments of TDP-43 sequester and inhibit proteasomes in neurons

TDP-43 inclusions enriched in C-terminal fragments of ~25kDa ("TDP-25") are associated with neurodegeneration in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Here, we analyzed gain-of-function mechanisms of TDP-25 combining cryo-electron tomography, proteomics and functional assays. TDP-25 inclusions are amorphous with gel-like biophysical properties and sequester proteasomes adopting exclusively substrate-processing conformations. This leads to proteostasis impairment, further enhanced by pathogenic mutations. These findings bolster the importance of proteasome dysfunction in ALS/FTD.

neuroscience↗

bioRxiv2021

The mutational signatures of formalin fixation on the human genome

BackgroundFormalin fixation and paraffin embedding (FFPE) of patient material remains standard practice in clinical pathology labs around the world. Clinical archives of patient material near-exclusively consist of FFPE blocks. The ability to perform high quality genome sequencing on FFPE-derived DNA would accelerate a broad spectrum of medical research. However, formalin is a recognised mutagen and sequencing of DNA derived from FFPE material is known to be riddled with artefactual mutations. ResultsHere we derive genome-wide mutational signatures caused by formalin fixation, and provide a computational method to correct mutational profiles for these formalin-induced artefacts. We show that the FFPE-signature is dominated by C>T transitions caused by cytosine deamination, and has very high similarity to COSMIC signature SBS30 (base excision repair deficiency due to inactivation mutations in NTHL1). Further, we demonstrate that chemical repair of formalin-induced DNA lesions, a process that is routinely performed as part of sequencing library preparation, leads to a signature highly similar to COSMIC signature SBS1 (spontaneous deamination of methylated cytosine). Next, we design FFPEsig, a computational method to remove the formalin-induced artefacts from mutational counts. We prove the efficacy of this method by generating synthetic FFPE samples using 2,780 cancer genomes from the Pan-Cancer Analysis of Whole Genome (PCAWG) project, and via analysis of FFPE-derived genome sequencing data from colorectal cancers. ConclusionsFormalin fixation leaves a predictable mutational footprint across the genome. The application of our FFPEsig software corrects the mutational profile for the influence of formalin, enabling robust mutational signature analysis in FFPE-derived patient material.

bioinformatics↗

bioRxiv2021

Identify phage hosts from metaviromic short reads based on deep learning and Markov chain model

Phages - viruses that infect bacteria and archaea - are dominant in the virosphere and play an important role in the microbial community. It is very important to identify the host of a given phage fragment from metavriome data for understanding the ecological impact of phage in a microbial community. State-of-the-art tools for host identification only present reliable results on long sequences within a narrow candidate host range, while there are a large number of short fragments in real metagenomic data and the taxonomic composition of a microbial community is often complicated. Here, we present a method, named HoPhage, to identify the host of a given phage fragment from metavirome data at the genus level. HoPhage integrates two modules using the deep learning algorithms and the Markov chain model, respectively. By testing on both the artificial benchmark dataset of phage contigs and the real virome data, HoPhage demonstrates a satisfactory performance on short fragments within a wide candidate host range at every taxonomic level. HoPhage is freely available at http://cqb.pku.edu.cn/ZhuLab/HoPhage/.

bioinformatics↗

bioRxiv2021

PolyQ expansion does not alter the Huntingtin-HAP40 complex

The abnormal amplification of a CAG repeat in the gene coding for huntingtin (HTT) leads to Huntington disease (HD). At the protein level, this translates into the expansion of a poly-glutamine (polyQ) stretch located at the HTT N-terminus, which renders it aggregation-prone by unknown mechanisms. Here we investigated the effects of polyQ expansion on HTT in a complex with its stabilizing interaction partner huntingtin-associated protein 40 (HAP40). Surprisingly, our comprehensive biophysical, crosslinking mass spectrometry and cryo-EM experiments revealed no major differences in the conformation of HTT-HAP40 complexes of various polyQ length, including 17QHTT-HAP40 (wild type), 46QHTT-HAP40 (typical polyQ length in HD patients) and 128QHTT-HAP40 (extreme polyQ length). Thus, HTT polyQ expansion does not alter the global structure of HTT when associated with HAP40.

biophysics↗

bioRxiv2021

Polymerase chain reaction-based assays facilitate the breeding and study of mouse models of Klinefelter syndrome

Klinefelter syndrome (KS) is one of the most frequent genetic abnormalities and the leading genetic cause of non-obstructive azoospermia. The breeding of mouse models of KS and their study are essential to advance our knowledge of the pathologic mechanism. Karyotyping and fluorescence in situ hybridization are reliable methods for identifying chromosomal contents. However, technical issues associated with these methods can decrease the efficiency of breeding KS mouse models and limit studies that require rapid identification of target mice. To overcome these limitations, we developed three polymerase chain reaction-based assays to measure the specific genetic information, including the presence or absence of Sry, copy number of Amelx, and Xist RNA transcript levels. Through a combined analysis of the assay results, we can infer the karyotype of target mice. We confirmed the utility of our assays with the successful generation of KS mouse models. Our assays are rapid, inexpensive, high capacity, easy to perform, and require small amounts of sample. Therefore, they facilitate the breeding and study of KS mouse models and help advance our knowledge of the pathologic mechanism underlying KS.

genetics↗

bioRxiv2021

An amiRNA screen uncovers redundant CBF & ERF34/35 transcription factors that differentially regulate arsenite and cadmium responses

Arsenic stress causes rapid transcriptional responses in plants. However, transcriptional regulators of arsenic-induced gene expression in plants remain less well known. To date, forward genetic screens have proven limited for dissecting arsenic response mechanisms. We hypothesized that this may be due to the extensive genetic redundancy present in plant genomes. To overcome this limitation, we pursued a forward genetics screen for arsenite tolerance using a randomized library of plants expressing >2,000 artificial microRNAs (amiRNAs). This library was designed to knock-down diverse combinations of homologous gene family members within sub-clades of transcription factor and transporter gene families. We identified six transformant lines showing an altered response to arsenite in root growth assays. Further characterization of an amiRNA line targeting closely homologous CBF and ERF transcription factors show that the CBF1,2 and 3 transcription factors negatively regulate arsenite sensitivity. Furthermore, the ERF34 and ERF35 transcription factors are required for cadmium resistance. Generation of CRISPR lines, higher-order T-DNA mutants, and gene expression analyses, further support our findings. These ERF transcription factors differentially regulate arsenite sensitivity and cadmium tolerance.

plant biology↗

bioRxiv2020

Distinguish virulent and temperate phage-derived sequences in metavirome data with a deep learning approach

BackgroundProkaryotic viruses referred to as phages can be divided into virulent and temperate phages. Distinguishing virulent and temperate phage-derived sequences in metavirome data is important for their role in interactions with bacterial hosts and regulations of microbial communities. However there is no experimental or computational approach to classify sequences of these two in culture-independent metavirome effectively, we present a new computational method DeePhage, which can directly and rapidly judge each read or contig as a virulent or temperate phage-derived fragment. FindingsDeePhage utilizes a "one-hot" encoding form to have an overall and detailed representation of DNA sequences. Sequence signatures are detected via a deep learning algorithm, namely a convolutional neural network to extract valuable local features. DeePhage makes better performance than the most related method PHACTS. The accuracy of DeePhage on five-fold validation reach as high as 88%, nearly 30% higher than PHACTS. Evaluation on real metavirome shows DeePhage annotated 54.4% of reliable contigs while PHACTS annotated 44.5%. While running on the same machine, DeePhage reduces computational time than PHACTS by 810 times. Besides, we proposed a new strategy to explore phage transformations in the microbial community by direct detection of the temperate viral fragments from metagenome and metavirome. The detectable transformation of temperate phages provided us a new insight into the potential treatment for human disease. ConclusionsDeePhage is the first tool that can rapidly and efficiently identify two kinds of phage fragments especially for metagenomics analysis with satisfactory performance. DeePhage is freely available via http://cqb.pku.edu.cn/ZhuLab/DeePhage or https://github.com/shufangwu/DeePhage.

bioinformatics↗

bioRxiv2020

De novo macrocyclic peptides for inhibiting, stabilising and probing the function of the Retromer endosomal trafficking complex

The Retromer complex (Vps35-Vps26-Vps29) is essential for endosomal membrane trafficking and signalling. Mutations in Retromer cause late-onset Parkinsons disease, while viral and bacterial pathogens can hijack the complex during cellular infection. To modulate and probe its function we have created a novel series of macrocyclic peptides that bind Retromer with high affinity and specificity. Crystal structures show the majority of cyclic peptides bind to Vps29 via a Pro-Leu-containing sequence, structurally mimicking known interactors such as TBC1D5, and blocking their interaction with Retromer in vitro and in cells. By contrast, macrocyclic peptide RT-L4 binds Retromer at the Vps35-Vps26 interface and is a more effective molecular chaperone than reported small molecules, suggesting a new therapeutic avenue for targeting Retromer. Finally, tagged peptides can be used to probe the cellular localisation of Retromer and its functional interactions in cells, providing novel tools for studying Retromer function.

biochemistry↗

bioRxiv2020

A β-catenin-driven switch in TCF/LEF transcription factor binding to DNA targets sites promotes commitment of mammalian nephron progenitor cells

The canonical Wnt pathway transcriptional co-activator {beta}-catenin regulates self-renewal and differentiation of mammalian nephron progenitor cells (NPCs). We modulated {beta}-catenin levels in NPC cultures using the GSK3 inhibitor CHIR9902 (CHIR) to examine opposing developmental actions of {beta}-catenin. Low CHIR-mediated maintenance and expansion of NPCs is independent of direct engagement of TCF/LEF/ {beta}-catenin transcriptional complexes at low-CHIR dependent cell-cycle targets. In contrast, in high CHIR, TCF7/LEF1/{beta}-catenin complexes replaced TCF7L1/TCF7L2 binding on enhancers of differentiation-promoting target genes. Chromosome confirmation studies showed pre-established promoter-enhancer connections to these target genes in NPCs. High CHIR-associated de novo looping was observed in positive transcriptional feedback regulation to the canonical Wnt pathway. Thus, {beta}-catenins direct transcriptional role is restricted to the induction of NPCs where rising {beta}-catenin levels switch inhibitory TCF7L1/TCF7L2 complexes to activating LEF1/TCF7 complexes at primed gene targets poised for rapid initiation of a nephrogenic program.

developmental biology↗

bioRxiv2020

Evolution of ST-4821 clonal complex hyperinvasive and quinolone-resistant meningococci: the next meningococcal pandemic?

The expansion of quinolone-resistant Neisseria meningitidis clone ChinaCC4821-R1-C/B from ST-4821 clonal complex (cc4821) caused a serogroup shift from serogroup A to C in invasive meningococcal disease (IMD) in China. To establish the relationship among globally distributed cc4821 meningococci, we analysed whole genome sequence data from 173 cc4821 meningococci isolated in four continents from 1972-2019. These meningococci clustered into four sub-lineages (1-4), with sub-lineage 1 primarily comprising serogroup C IMD isolates (82%, 41/50). Most isolates from outside China formed a distinct sub-lineage (81.6%, 40/49, the Europe-USA cluster), with the typical strain designation B:P1.17-6,23:F3-36:ST-3200(cc4821) and harbouring mutations in penicillin-binding protein 2. These data show that the quinolone-resistant clone ChinaCC4821-R1-C/B has expanded to other countries. The increasing global distribution of B:cc4821 meningococci raises concern that cc4821 has the potential to cause a global pandemic and, this would be challenging to control though there is indirect evidence that Trumenba(R) vaccine might afford some protection.

bioinformatics↗

bioRxiv2020

Telmisartan potentiates insulin secretion via ion channels, independent of the AT1 receptor and PPARγ

Angiotensin II type 1 receptor blockers (ARBs), as antihypertensive drugs, have drawn attention for their benefits to individuals with diabetes and prediabetes. However, the effects of ARBs on insulin secretion remain unclear. Here, we investigated the insulinotropic effects of ARBs (telmisartan, valsartan, and irbesartan) and the underlying electrophysiological mechanism in rat islets. We found that only telmisartan among the three ARBs exhibited an insulin secretagogue role. Distinct from other ARBs, telmisartan exerted effects on ion channels including voltage-gated potassium (Kv) channels and voltage-gated Ca2+ channels to promote extracellular Ca2+ influx, thereby potentiating insulin secretion in a glucose-dependent manner. We observed that the peroxisome proliferator-activated receptor {gamma} pathway was not involved in these telmisartan-induced effects. Furthermore, we identified that telmisartan at least directly inhibited Kv2.1 channel through construction of a Chinese hamster ovary cell line with Kv2.1 channel overexpression. Acute exposure of type 2 diabetes model (db/db) mice to a telmisartan dose equivalent to therapeutic doses in humans resulted in lower blood glucose and increased plasma insulin concentration in the oral glucose tolerance test. We further observed the telmisartan-induced insulinotropic and electrophysiological effects on pathological pancreatic islets isolated from db/db mice. Collectively, our results establish an important function of telmisartan distinct from other ARBs in the treatment of diabetes.

cell biology↗

bioRxiv2020

Molecular basis for cysteine oxidation by Plant Cysteine Oxidases from Arabidopsis thaliana

Plant Cysteine Oxidases (PCOs) play important roles in controlling the stability of Group VII ethylene response factors (ERF-VIIs) via N-Arg/degron pathway through catalyzing the oxidation of their N-Cys for subsequent Arginyl-tRNA--protein transferase 1 (ATE1) mediated arginine installation. Here we presented structures of PCO2, PCO4, and PCO5 from Arabidopsis thaliana (AtPCOs) and examined their in vitro activity by MS. On the basis of Tris-bound AtPCO2, we modelled the Cys-bound AtPCO2 structure and identified key residues involved in N-Cys oxidation. Alanine substitution of potential N-Cys interaction residues impaired the activity of AtPCO5 remarkably. The structural research, complemented by mutagenesis and mass spectrometry experiments, not only uncovers the substrate recognition and catalytic mode by AtPCOs, but also sheds light on the future design of potent inhibitors for plant cysteine oxidases.

molecular biology↗

bioRxiv2020

Population-based Carrier Screening and Prenatal Diagnosis of Fragile X Syndrome in East Asian Populations

Identification of carriers of fragile X syndrome (FXS) with the subsequent prenatal diagnosis, and knowledge of FXS-associated genetic profiles are essential for intervention in specific populations. We report the results of carrier screening of 39,458 East Asian adult women and prenatal diagnosis from 87 FXS carriers. The prevalence of FXS carriers and incidence of full mutation fetuses in carrier pregnancies were found to be 1/556 and 11.0%, respectively. The prevalence of FXS carriers and full mutation fetuses was estimated to be 1/581 and 1/3124 in East Asian populations, respectively. We confirmed the validity of the current threshold of CGG repeats for FMR1 categorization; the integral risks of full mutation expansion were approximately 6.0%, 43.8%, and 100% for premutation alleles with 55-74, 75-89, and [≥]90 CGG repeats, respectively. The protective effect of AGG interruption in East Asian populations was validated, which is important in protecting premutation alleles with 75-89 CGG repeats from full mutation expansion. Lastly, family history was shown not an effective indicator for FXS carrier screening in East Asian populations and population-based screening was more cost-effective. This study provides an insight into the largest carrier screening and prenatal diagnosis for FXS in East Asian populations to date. The FXS-associated genetic profiles of East Asian populations are delineated and population-based carrier screening is shown to be promising for FXS intervention.

genetics↗

bioRxiv2020

Small molecules inhibit SARS-COV-2 induced aberrant inflammation and viral replication in mice by targeting S100A8/A9-TLR4 axis

The SARS-CoV-2 pandemic poses an unprecedented public health crisis. Accumulating evidences suggest that SARS-CoV-2 infection causes dysregulation of immune system. However, the unique signature of early immune responses remains elusive. We characterized the transcriptome of rhesus macaques and mice infected with SARS-CoV-2. Alarmin S100A8 was robustly induced by SARS-CoV-2 in animal models as well as in COVID-19 patients. Paquinimod, a specific inhibitor of S100A8/A9, could reduce inflammatory response and rescue the pneumonia with substantial reduction of viral titers in SASR-CoV-2 infected animals. Remarkably, Paquinimod treatment resulted in 100% survival of mice in a lethal model of mouse coronavirus (MHV) infection. A novel group of neutrophils that contributed to the uncontrolled inflammation and onset of COVID-19 were dramatically induced by coronavirus infections. Paquinimod treatment could reduce these neutrophils and regain antiviral responses, unveiling key roles of S100A8/A9 and noncanonical neutrophils in the pathogenesis of COVID-19, highlighting new opportunities for therapeutic intervention.

immunology↗