bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effective infection with dengue virus in experimental neonate and adult mice through intranasal route
Authors: Qiu Minyue , Zhao Lixin , Zhang Junjie , Wang Yalan , Liu Minchi , Hua Dong , Ding Xiaoyan , Zhou Xiaoyang , Zeng Jie , Yan Huacheng , Li Jintao 
Published: February 2022

AbstractAs a member of the family Flaviviridae, the dengue virus is transmitted to humans through mosquito vectors. The virus causes dengue fever with flu-like symptoms, life-threatening dengue hemorrhagic fever, and dengue shock syndrome that affects four billion people in 128 countries. It can also be transmitted through atypical routes, such as needle stick injury, vertical transmission, and the receipt of contaminated blood or organs. Although sporadic cases cannot be classified as atypical transmission routes and raise respiratory exposure concerns, the risks remain unclear. Here, we analyzed the respiratory infectivity of the dengue virus in BALB/c suckling and A6 adult mice using the dengue virus serotype 2 and intranasal inoculation. The results showed that the clinical symptoms of intranasally infected mice included excitement, emaciation, malaise, and death, and histopathological changes and viremia dynamics were observed in multiple tissues, including the brain, liver, and spleen. Notably, the DENV serotype 2 showed clear brain tropism after intranasal infection, and viral loads peaked at seven days post-inoculation. Furthermore, the virus was isolated from mouse brains, and the sequence homology between the viral stock and dengue virus isolates was 99.99%. Similar results were observed in adult IFN-α/β receptor-deficient mice. Taken together, our results suggest that the DENV serotype 2 can infect suckling mice and adult immune-deficient mice via the nasal route. The results of our study broaden our perception of atypical dengue transmission routes and may help explain dengue virus infections that occur without the presence of mosquito vectors.ImportanceDengue is transmitted mainly via mosquito vectors. Flu-like dengue fever or life-threatening severe dengue threatens four billion people in 128 countries. Non-vector dengue cases have occurred occasionally since 1990. These cases cannot be classified as atypical transmission routes and are suspected to have arisen via sexual or respiratory transmission. Recently, the sexual transmission of dengue has been confirmed in humans. The respiratory infectivity of other members of the Flaviviridae family, such as Zika and Japanese encephalitis viruses, has been determined under experimental conditions. The potential for respiratory infection with the dengue virus has not yet been confirmed. In this study, we analyzed the respiratory infectivity of the dengue virus in suckling mice and adult immunodeficient mice via intranasal inoculation, thereby exploring the potential for respiratory transmission in cases with non-vector dengue infection, especially for patients who were exposed to dengue virus contaminants.
Loss of β-ketoacyl acyl carrier protein synthase III activity restores multidrug-resistantEscherichia colisensitivity to previously ineffective antibiotics
Authors: Hong Yaoqin , Qin Jilong , Verderosa Anthony D. , Hawas Sophia , Zhang Bing , Blaskovich Mark A. T. , Cronan John E. , Totsika Makrina 
Published: February 2022

ABSTRACTAntibiotic resistance is one of the most prominent threats to modern medicine. In the latest World Health Organization list of bacterial pathogens that urgently require new antibiotics, nine out of 12 are Gram-negative, with four being of ‘Critical Priority’. One crucial barrier restricting antibiotic efficacy against Gram-negative bacteria is their unique cell envelope. While fatty acids are a shared constituent of all structural membrane lipids, their biosynthesis pathway in bacteria is distinct from eukaryotes making it an attractive target for new antibiotic development that remains less explored. Here, we interrogated the redundant components of the bacterial Type IIFattyAcidSynthesis (FAS II) pathway, showing that disrupting FAS II homeostasis inEscherichia colithrough deletion of thefabHgene damages the cell envelope of antibiotic susceptible and antibiotic resistant clinical isolates. ThefabHgene encodes the β-ketoacyl acyl carrier protein synthase III (KAS III), which catalyzes the initial condensation reactions during fatty acid biosynthesis. We show thatfabHnull mutation potentiated the killing of multi-drug resistantE. coliby a broad panel of previously ineffective antibiotics, despite the presence of relevant antibiotic resistance determinants, for example, carbapenemasekpc2. Enhanced antibiotic sensitivity was additionally demonstrated in the context of eradicating established biofilms and treating established human cell infectionin vitro. Our findings showcase the potential of FabH as a promising target that could be further explored in the development of therapies that may repurpose currently ineffective antibiotics or rescue failing last-resort antibiotics against Gram-negative pathogens.IMPORTANCEGram-negative pathogens are a major concern for global public health due to increasing rates of antibiotic resistance and the lack of new drugs. A major contributing factor towards antibiotic resistance in Gram-negative bacteria is their formidable outer membrane, which acts as a permeability barrier preventing many biologically active antimicrobials from reaching the intracellular targets and thus limiting their efficacy. Fatty acids are the fundamental building blocks of structural membrane lipids and their synthesis constitutes an attractive antimicrobial target as it follows distinct pathways in prokaryotes and eukaryotes. Herein, we identified a component of fatty acid synthesis, FabH, as a ‘gate-keeper’ of outer membrane barrier function. Without FabH, Gram-negative bacteria become susceptible to otherwise impermeable antibiotics and are re-sensitised to killing by last-resort antibiotics. This study supports FabH as a promising target for inhibition in future antimicrobial therapies.
Identification of a SARS-CoV-2 host metalloproteinase-dependent entry pathway differentially used by SARS-CoV-2 and variants of concern Alpha, Delta, and Omicron
Authors: Benlarbi Mehdi , Laroche Geneviève , Fink Corby , Fu Kathy , Mulloy Rory P. , Phan Alexandra , Ariana Ardeshir , Stewart Corina M. , Prévost Jérémie , Beaudoin-Bussières Guillaume , Daniel Redaet , Bo Yuxia , Yockell-Lelièvre Julien , Stanford William L. , Giguère Patrick M. , Mubareka Samira , Finzi Andrés , Dekaban Gregory A. , Dikeakos Jimmy D. , Côté Marceline 
Published: February 2022

ABSTRACTTo infect cells, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) binds to angiotensin converting enzyme 2 (ACE2) via its spike glycoprotein (S), delivering its genome upon S-mediated membrane fusion. SARS-CoV-2 uses two distinct entry pathways: 1) a surface, serine protease-dependent or 2) an endosomal, cysteine protease-dependent pathway. In investigating serine protease-independent cell-cell fusion, we found that the matrix metalloproteinases (MMPs), MMP2/9, can activate SARS-CoV-2 S fusion activity, but not that of SARS-CoV-1. Importantly, metalloproteinase activation of SARS-CoV-2 S represents a third entry pathway in cells expressing high MMP levels. This route of entry required cleavage at the S1/S2 junction in viral producer cells and differential processing of variants of concern S dictated its usage. In addition, metalloproteinase inhibitors reduced replicative Alpha infection and abrogated syncytia formation. Finally, we found that the Omicron S exhibit reduced metalloproteinase-dependent fusion and viral entry. Taken together, we identified a MMP2/9-dependent mode of activation of SARS-CoV-2 S. As MMP2/9 are released during inflammation and severe COVID-19, they may play important roles in SARS-CoV-2 S-mediated cytopathic effects, tropism, and disease outcome.
Right atrial mechanism contributes to atrial fibrillation in a canine model of pulmonary arterial hypertension
Authors: Liu Yang , Zhu Xiyao , Song Ziliang , Qin Mu , Xu Changhao , Liu Xu 
Published: February 2022

AbstractObjectivesThe aim of this study was to investigate proarrhythmic substrates of atrial fibrillation (AF) in a canine model of dehydromonophylline (DMCT)-induced pulmonary arterial hypertension (PAH).MethodsAll cannines (n=12) underwent baseline echocardiographic and hemodynamic examinations, 7 of which were injected with DMCT (3.0mg/kg) to induce PAH via jugular vein cannulation. The control beagles (n=5) were given the same dose of normal saline. Then, both groups were monitored by insertable cardiac monitors. Hemodynamic, echocardiographic, electrophysiological and histological examinations were performed 8 weeks later.ResultsIn PAH group, 2 died after the injection (mortality 28.6%). Thus, 10 beagles (PAH group: 5, control group: 5) underwent all the examinations. The pulmonary artery pressure increased significantly while the right atrium (RA) and right ventricle expanded slightly. Spontaneous AF episodes were recorded in all PAH canines 1 week after the injection. The AF burden increased rapidly from 1 week (7.6±1.8%) and remained high after 2-3 weeks (32.0±4.9% at 8 weeks). Compared with the control group, the PAH group had abbreviated effective refractory periods (ERPs), increased atrial ERP dispersion, and slower conduction velocities. Notably, AF susceptibility and atrial remodeling in RA was more significant those in LA, such as increased WOV(39.0±6.5ms vs. 28.0±5.7ms, P=0.022), enlarged low voltage regions (7.66±0.46% vs. 4.40±0.55%, P<0.0001) and fibrosis (8.22±0.61% vs. 4.93±0.60%, P <0.0001).ConclusionsDMCT-induced canine PAH model increased the incidence of spontaneous and induced AF. The electrophysiological and structural remodeling of the RA facilitated the AF genesis.
Joint effect of changing selection and demography on the site frequency spectrum
Authors: Jain Kavita , Kaushik Sachin 
Published: February 2022

AbstractThe site frequency spectrum (SFS) is an important statistic that summarizes the molecular variation in a population, and used to estimate population-genetic parameters and detect natural selection. While the equilibrium SFS in a constant environment is quite well studied, recent research has focused on nonequilibrium SFS to elucidate the role of demography when selection is constant in time and of fluctuating selection in a population of constant size. However, the joint effect of time-dependent selection and population size has not been investigated so far. Here, we study the SFS in a randomly mating, diploid population in which both the population size and selection coefficient vary periodically with time using a diffusion theory approach, and derive simple analytical expressions for the time-averaged SFS in slowly and rapidly changing environments. We show that for strong selection and in slowly changing environments, the time-averaged SFS differs significantly from the equilibrium SFS when the population experiences both positive and negative cycles of the selection coefficient. The deviation depends on the time spent by the population in the deleterious part of the selection cycle and the phase difference between the selection coefficient and population size. In particular, we find that the time-averaged SFS in slowly to moderately fast varying, on-average neutral environment has the same qualitative shape as the equilibrium SFS for positively selected mutant but differs quantitatively from it which can be captured by an effective population size.
Modular capsid decoration boosts adenovirus vaccine-induced humoral and cellular immunity against SARS-CoV-2
Authors: Dicks Matthew D. J. , Rose Louisa M. , Bowman Lesley A. H. , Graham Carl , Doores Katie J. , Malim Michael H. , Draper Simon J. , Howarth Mark , Biswas Sumi 
Published: February 2022

AbstractAdenovirus vector vaccines have been widely and successfully deployed in response to COVID-19. However, despite inducing potent T cell immunity, improvement of vaccine-specific antibody responses upon homologous boosting is modest compared to other technologies. Here, we describe a system to enable modular decoration of adenovirus capsid surfaces with protein antigens and demonstrate induction of potent humoral immunity against these displayed antigens. Ligand attachment via a covalent isopeptide bond was achieved in a rapid and spontaneous reaction, requiring simple co-incubation of ligand and vector components. We used a recently described protein superglue, DogTag/DogCatcher, which is similar to the widely used SpyTag/SpyCatcher ligation system but performs better in loop structures. DogTag was inserted into surface-exposed loops in the adenovirus hexon protein to allow attachment of DogCatcher-fused ligands on virus particles. Efficient coverage of the capsid surface was achieved using a variety of ligands and vector infectivity was retained in each case. Capsid decoration shielded particles from anti-adenovirus neutralizing antibodies. In prime-boost regimens, proof-of-concept COVID-19 adenovirus vaccines decorated with the receptor-binding domain (RBD) of SARS-CoV-2 spike induced >10-fold higher SARS-CoV-2 neutralization titers compared to an undecorated adenovirus vector encoding spike. Importantly, decorated vectors retained robust T cell immunogenicity to encoded antigens, a key hallmark of adenovirus vector vaccines. We propose capsid decoration via protein superglue-mediated covalent ligation as a novel strategy to improve the efficacy and boostability of adenovirus-based vaccines and therapeutics.One Sentence SummaryDecorating the capsid surface of adenovirus vaccine vectors using a spontaneous protein superglue induces potent pathogen-specific immunity
TFIIB-related factor 1 is a nucleolar protein that promotes RNA polymerase I-directed transcription and tumour cell growth
Authors: Wang Juan , Chen Qiyue , Wang Xin , Zhao Shasha , Deng Huan , Guo Baoqiang , Zhang Cheng , Song Xiaoye , Deng Wensheng , Zhang Shihua , Zhang Tongcun , Ni Hongwei 
Published: February 2022

AbstractRNA polymerase I (Pol I) products play pivotal roles in ribosomal assembly, protein synthesis and cell growth. Dysregulation of Pol I product synthesis closely correlates with tumourigenesis. However, the factors and pathways governing Pol I-dependent transcription remain to be identified. Here, we report that TFIIB-related factor 1 (BRF1), a subunit of TFIIIB required for Pol III-mediated transcription, is a nucleolar protein and modulates the rRNA synthesis directed by Pol I. We show that BRF1 can be co-localized with nucleolar protein markers in several human cell types. BRF1 expression positively correlates with Pol I product levels and tumour cell growth in vitro and in vivo. Mechanistically, BRF1 binds to the Pol I transcription machinery factors and is recruited to the rDNA promoter with them. Alteration of BRF1 expression affected the recruitment of Pol I transcription machinery at the rDNA promoter, the rDNA promoter activity and expression of TBP and TAF1A, indicating that BRF1 modulates Pol I-direct transcription by controlling the expression of selective factor 1 subunits. Collectively, we demonstrate that BRF1 acts as a positive factor to regulate Pol I-directed transcription, suggesting that BRF1 can concurrently modulate Pol I and Pol III transcription and acts as a key coordinator between them.
Acute thermal stress elicits interactions between gene expression and alternative splicing in a fish of conservation concern
Authors: Thorstensen Matt J , Turko Andy J , Heath Daniel D , Jeffries Ken M , Pitcher Trevor E 
Published: February 2022

ABSTRACTTranscriptomics provides a mechanistic understanding of an organism’s response to environmental challenges such as increasing temperatures, which can provide key insights into the threats posed by thermal challenges associated with urbanization and climate change. Differential gene expression and alternative splicing are two elements of the transcriptomic stress response that may work in tandem, but relatively few studies have investigated these interactions in fishes of conservation concern. We studied the imperilled redside dace (Clinostomus elongatus) as thermal stress is hypothesised to be an important cause of population declines. We tested the hypothesis that gene expression-splicing interactions contribute to the thermal stress response. Wild fish exposed to acute thermal stress were compared with both handling controls and fish sampled directly from a river. Liver tissue was sampled to study the transcriptomic stress response. Thermally stressed fish showed a prominent transcriptional response (estimated with mRNA transcript abundance) related to transcription regulation and responses to unfolded proteins, and prominent alternatively spliced genes related to gene expression regulation and metabolism. One splicing factor, prpf38b, was upregulated in the thermally stressed group compared to the other treatments. This splicing factor may have a role in the Jun/AP-1 cellular stress response, a pathway with wide-ranging and context-dependent effects. Given large gene interaction networks and the context-dependent nature of transcriptional responses, our results highlight the importance of understanding interactions between gene expression and splicing for understanding transcriptomic responses to thermal stress. Our results also reveal transcriptional pathways that can inform conservation breeding, translocation, and reintroduction programs for redside dace and other imperilled species by identifying appropriate source populations.SUMMARY STATEMENTGene expression and alternative splicing interact in response to thermal stress in an imperilled fish, with implications for conservation and mechanisms of thermal tolerance in vertebrate ectotherms.
Performance of plasma amyloid, tau, and astrocyte biomarkers to identify cerebral AD pathophysiology
Authors: Ferreira Pâmela C. L , Tissot Cécile , Ferrari-Souza João Pedro , Brum Wagner S. , Bellaver Bruna , Leffa Douglas T. , Therriault Joseph , Benedet Andréa L. , Lussier Firoza Z. , Chamoun Mira , Bezgin Gleb , Servaes Stijn , Stevenson Jenna , Rahmouni Nesrine , Pallen Vanessa , Kang Min Su , Poltronetti Nina Margherita , Tudorascu Dana L. , Klunk William E. , Villemagne Victor L. , Cohen Annie , Gauthier Serge , Zimmer Eduardo R. , Ashton Nicholas J. , Zetterberg Henrik , Blennow Kaj , Karikari Thomas K. , Rosa-Neto Pedro , Pascoal Tharick A. 
Published: February 2022

AbstractIntroductionPlasma amyloid-β (Aβ), phosphorylated tau (p-tau), and glial fibrillar acid protein (GFAP) can identify Alzheimer’s disease (AD) pathophysiology with high accuracy. However, comparing their performance in the same individuals remains under-explored.MethodsWe compared the predictive performance of plasma Aβ42/40, p-tau(at threonine 181 and 231), neurofilament light (NfL), and GFAP to identify Aβ- and tau-PET positivity in 138 cognitive unimpaired (CU) and 87 cognitive impaired (CI) individuals.ResultsIn CU, plasma p-tau231 had the best performance to identify both Aβ- and tau-PET positivity. In CI, plasma GFAP showed the best predictive accuracy to identify both Aβ and tau-PET positivity.DiscussionOur results support plasma p-tau231 as a marker of early AD pathology and, that GFAP best identifies both PET Aβ and tau abnormalities in the brain of CI individuals. These findings highlight that the performance of blood-based protein biomarkers to identify the presence of AD pathophysiology is disease-stage dependent.
Next Generation Opto-Jasplakinolides Enable Local Remodeling of Actin Networks
Authors: Küllmer Florian , Vepřek Nynke A. , Borowiak Malgorzata , Nasufović Veselin , Barutzki Sebastian , Thorn-Seshold Oliver , Arndt Hans-Dieter , Trauner Dirk 
Published: February 2022

AbstractThe natural product jasplakinolide is a widely used tool compound to stabilize F-actin and influence actin dynamics. We have previously introduced photoswitchable jasplakinolides (optojasps) that are activated with violet light and deactivated with blue light. Based on insights from cryo-electron microscopy and structure-activity relationship (SAR) studies, we now developed a new generation of functionally superior optojasps that are better suited for biological investigations. These compounds are procured through chemical total synthesis and feature rationally designed red-shifted azobenzene photoswitches. Our new optojasps can be activated with longer wavelengths in the visible range (e.g. 440-477 nm) and rapidly return to their inactive state through thermal relaxation. This has enabled the reversible control of F-actin dynamics, as shown through live-cell imaging and cell migration, as well as cell proliferation assays. Brief sub-cellular activation with blue-green light resulted in highly localized F-actin clusters that gradually dissolved in the dark. Our light-responsive tools can be useful in diverse fields to study actin dynamics with outstanding spatiotemporal precision.Graphical Abstract
Comprehensive analysis of PNA-based antisense antibiotics targeting various essential genes in uropathogenic Escherichia coli
Authors: Popella Linda , Jung Jakob , Do Phuong Thao , Barquist Lars , Vogel Jörg 
Published: February 2022

ABSTRACTAntisense peptide nucleic acids (PNAs) that target mRNAs of essential bacterial genes exhibit specific bactericidal effects in several microbial species, but our mechanistic understanding of PNA activity and their target gene spectrum is limited. Here, we present a systematic analysis of PNAs targeting eleven essential genes with varying expression levels in uropathogenic Escherichia coli (UPEC). We demonstrate that UPEC is susceptible to killing by peptide-conjugated PNAs, especially when targeting the widely-used essential gene acpP. Our evaluation yields three additional promising target mRNAs for effective growth inhibition, i.e., dnaB, ftsZ, and rpsH. The analysis also shows that transcript abundance does not predict target vulnerability and that PNA-mediated growth inhibition is not universally associated with target mRNA depletion. Global transcriptomic analyses further reveal PNA sequence-dependent but also -independent responses, including the induction of envelope stress response pathways. Importantly, we show that the growth inhibitory capacity of 9mer PNAs is generally as effective as their 10mer counterparts. Overall, our systematic comparison of a range of PNAs targeting mRNAs of different essential genes in UPEC suggests important features for PNA design, reveals a general bacterial response to PNA conjugates and establishes the feasibility of using PNA antibacterials to combat UPEC.
Quantitative Proteomic Profiling of Murine Embryonic Heart Development Reveals a Role for the Mevalonate Pathway in Cardiomyocyte Proliferation
Authors: Edwards Whitney , Greco Todd M. , Miner Gregory E. , Barker Natalie K. , Herring Laura , Cohen Sarah , Cristea Ileana M. , Conlon Frank L. 
Published: February 2022

SUMMARYDefining the molecular mechanisms that govern heart development is essential for identifying the etiology of congenital heart disease. Here, quantitative proteomics was used to measure temporal changes in the cardiac proteome at eight critical stages of murine embryonic heart development. Global temporal profiles of the over 7,300 identified proteins uncovered signature cardiac protein interaction networks that linked protein dynamics with molecular pathways. Using this integrated dataset, we identified and established a functional role for the mevalonate pathway in the regulation of embryonic cardiomyocyte proliferation and cell signaling. Overall, our proteomic datasets are an invaluable resource for studying molecular events that regulate embryonic heart development and contribute to congenital heart disease.