bluuebunny/crossref_metadata_2025_split huggingface dataset:
Binding of the Andes Virus Nucleocapsid Protein to RhoGDI Induces the Release and Activation of the Permeability Factor RhoA
Authors: Gorbunova Elena E. , Mackow Erich R. 
Published: March 2021

AbstractAndes virus (ANDV) nonlytically infects pulmonary microvascular endothelial cells (PMECs) causing acute pulmonary edema termed hantavirus pulmonary syndrome (HPS). In HPS patients virtually every PMEC is infected, however the mechanism by which ANDV induces vascular permeability and edema remains to be resolved. The ANDV nucleocapsid (N) protein activates the GTPase, RhoA, in primary human PMECs causing VE-Cadherin internalization from adherens junctions and PMEC permeability. We found that ANDV N protein failed to bind RhoA, but co-precipitates RhoGDI (Rho GDP-dissociation inhibitor), the primary RhoA repressor that normally sequesters RhoA in an inactive state. ANDV N protein selectively binds the RhoGDI C-terminus (69-204) but fails to form ternary complexes with RhoA or inhibit RhoA binding to the RhoGDI N-terminus (1-69). However, we found that ANDV N protein uniquely inhibits RhoA binding to an S34D phosphomimetic RhoGDI mutant. Hypoxia and VEGF increase RhoA induced PMEC permeability by directing Protein Kinase Cα (PKCα) phosphorylation of S34 on RhoGDI. Collectively, ANDV N protein alone activates RhoA by sequestering and reducing RhoGDI available to suppress RhoA. In response to hypoxia and VEGF activated PKCα, ANDV N protein additionally directs the release of RhoA from S34-phosphorylated RhoGDI, synergistically activating RhoA and PMEC permeability. These findings reveal a fundamental edemagenic mechanism that permits ANDV to amplify PMEC permeability in hypoxic HPS patients. Our results rationalize therapeutically targeting PKCα and opposing Protein Kinase A (PKA) pathways that control RhoGDI phosphorylation as a means of resolving ANDV induced capillary permeability, edema and HPS.ImportanceHPS causing hantaviruses infect pulmonary endothelial cells causing vascular leakage, pulmonary edema and a 35% fatal acute respiratory distress syndrome (ARDS). Hantaviruses don’t lyse or disrupt the endothelium but dysregulate normal EC barrier functions and increase hypoxia directed permeability. Our findings reveal a novel underlying mechanism of EC permeability resulting from ANDV N protein binding to RhoGDI, a regulatory protein that normally maintains edemagenic RhoA in an inactive state and inhibits EC permeability. ANDV N sequesters RhoGDI and enhances the release of RhoA from S34 phosphorylated RhoGDI. These findings indicate that ANDV N induces the release of RhoA from PKC phosphorylated RhoGDI, synergistically enhancing hypoxia directed RhoA activation and PMEC permeability. Our data suggests inhibiting PKC and activating PKA phosphorylation of RhoGDI as mechanisms of inhibiting ANDV directed EC permeability and therapeutically restricting edema in HPS patients. These findings may be broadly applicable to other causes of ARDS.
SARS-CoV-2 surveillance in Norway rats (Rattus norvegicus) from Antwerp sewer system, Belgium
Authors: Colombo Valeria Carolina , Sluydts Vincent , Mariën Joachim , Broecke Bram Vanden , Van Houtte Natalie , Leirs Wannes , Jacobs Lotte , Iserbyt Arne , Hubert Marine , Heyndrickx Leo , Goris Hanne , Delputte Peter , De Roeck Naomi , Elst Joris , Boudewijns Robbert , Ariën Kevin K. , Leirs Herwig , Gryseels Sophie 
Published: March 2021

AbstractBackgroundSARS-CoV-2 human-to-animal transmission can lead to the establishment of novel reservoirs and the evolution of new variants with the potential to start new outbreaks in humans.AimWe tested Norway rats inhabiting the sewer system of Antwerp, Belgium, for the presence of SARS-CoV-2 following a local COVID-19 epidemic peak. In addition, we discuss the use and interpretation of SARS-CoV-2 serological tests on non-human samples.MethodsBetween November and December 2020, Norway rat oral swabs, feces and tissues from the sewer system of Antwerp were collected to be tested by RT-qPCR for the presence of SARS-CoV-2. Serum samples were screened for the presence of anti-SARS-CoV-2 IgG antibodies using a Luminex microsphere immunoassay (MIA). Samples considered positive were then checked for neutralizing antibodies using a conventional viral neutralization test (cVNT).ResultsThe serum of 35 rats was tested by MIA showing 3 potentially positive sera that were later shown to be negative by cVNT. All tissue samples of 39 rats analyzed tested negative for SARS-CoV-2 RNA.ConclusionThis is the first study that evaluates SARS-CoV-2 infection in urban rats. We can conclude that the sample of 39 rats had never been infected with SARS-CoV-2. We show that diagnostic serology tests can give misleading results when applied on non-human samples. SARS-CoV-2 monitoring activities should continue due to the emergence of new variants prone to infect Muridae rodents.
Diversification ofB. subtilisduring experimental evolution onA. thalianaand the complementarity in root colonization of evolved subpopulations
Authors: Blake Christopher , Nordgaard Mathilde , Maróti Gergely , Kovács Ákos T. 
Published: March 2021

SummaryThe soil bacteriumBacillus subtilisis known to suppress pathogens as well as promote plant growth. However, in order to fully exploit the potential as natural fertilizer, we need a better understanding of the interactions betweenB. subtilisand plants. Here,B. subtiliswas examined for root colonization through experimental evolution onArabidopsis thaliana. The populations evolved rapidly, improved in root colonization and diversified into three distinct morphotypes. In order to better understand the adaptation that had taken place, single evolved isolates from the final transfer were randomly selected for further characterization, revealing changes in growth and pellicle formation in medium supplemented with plant polysaccharides. Intriguingly, certain evolved isolates showed improved root colonization only on the plant species they evolved on, but not on another plant species, namely tomato, suggestingA. thalianaspecific adaption paths. Finally, the mix performed better than the sum of its constituents in monoculture, which was demonstrated to be caused by complementarity effects. Our results suggest, that genetic diversification occurs in an ecological relevant setting on plant roots and proves to be a stable strategy for root colonization.Significance StatementUnderstanding how plant-growth-promoting rhizobacteria (PGPR) colonize plant roots is crucial to fully utilize their potential for agricultural applications. Here, we employ experimental evolution of the PGPRBacillus subtilisonArabidopsis thalianato study root colonization. We revealed that evolving populations rapidly improve in root colonization and diversify into distinct morphotypes. Notably, improved root colonization by evolved isolates was observed onA. thaliana, not on tomato. Moreover, isolates of distinct morphotypes interacted during root colonization and the mixture of morphotypes showed higher productivity than predicted. These findings suggest that genetic diversification might be a stable strategy to maximize root colonization.
Biochemical reconstitution defines new functions for membrane-bound glycosidases in assembly of the bacterial cell wall
Authors: Taguchi Atsushi , Walker Suzanne 
Published: March 2021

ABSTRACTThe peptidoglycan cell wall is a macromolecular structure that encases bacteria and is essential for their survival. Proper assembly of the cell wall requires peptidoglycan synthases as well as membrane-bound cleavage enzymes that control where new peptidoglycan is made and inserted. We are only beginning to understand the roles of peptidoglycan cleavage enzymes in cell wall assembly. Previous studies have shown that two membrane-bound proteins inStreptococcus pneumoniae, here named MpgA and MpgB, are important in maintaining cell wall integrity. MpgA was predicted to be a lytic transglycosylase based on its homology toEscherichia coliMltG while the enzymatic activity of MpgB was unclear. Using nascent peptidoglycan substrates synthesizedin vitrofrom the peptidoglycan precursor Lipid II, we report that both MpgA and MpgB are muramidases. We show that replacing a single amino acid inE. coliMltG with the corresponding amino acid from MpgA results in muramidase activity, allowing us to predict from the presence of this amino acid that other putative lytic transglycosylases actually function as muramidases. Strikingly, we report that MpgA and MpgB cut nascent peptidoglycan at different positions along the sugar backbone relative to the reducing end. MpgA produces much longer peptidoglycan oligomers and we show that its cleavage site selectivity is controlled by the LysM-like subdomain, which is also present in MltG. We propose that MltG’s ability to complement loss of MpgA inS. pneumoniae despite performing different cleavage chemistry is because it can cleave nascent peptidoglycan at the same distance from the lipid anchor.
Resolving the Dynamic Motions of SARS-CoV-2 nsp7 and nsp8 Proteins Using Structural Proteomics
Authors: Courouble Valentine V. , Dey Sanjay Kumar , Yadav Ruchi , Timm Jennifer , Harrison Jerry Joe E. K. , Ruiz Francesc X. , Arnold Eddy , Griffin Patrick R. 
Published: March 2021

ABSTRACTCoronavirus (CoV) non-structural proteins (nsps) assemble to form the replication-transcription complex (RTC) responsible for viral RNA synthesis. nsp7 and nsp8 are important cofactors of the RTC, as they interact and regulate the activity of RNA-dependent RNA polymerase (RdRp) and other nsps. To date, no structure of full-length SARS-CoV-2 nsp7:nsp8 complex has been published. Current understanding of this complex is based on structures from truncated constructs or with missing electron densities and complexes from related CoV species with which SARS-CoV-2 nsp7 and nsp8 share upwards of 90% sequence identity. Despite available structures being solved using crystallography and cryo-EM representing detailed snapshots of the nsp7:nsp8 complex, it is evident that the complex has a high degree of structural plasticity. However, relatively little is known about the conformational dynamics of the complex and how it assembles to interact with other nsps. Here, the solution-based structural proteomic techniques, hydrogen-deuterium exchange mass spectrometry (HDX-MS) and crosslinking mass spectrometry (XL-MS), illuminate the structural dynamics of the SARS-CoV-2 full-length nsp7:nsp8 complex. The results presented from the two techniques are complementary and validate the interaction surfaces identified from the published three-dimensional heterotetrameric crystal structure of SARS-CoV-2 truncated nsp7:nsp8 complex. Furthermore, mapping of XL-MS data onto higher order complexes suggests that SARS-CoV-2 nsp7 and nsp8 do not assemble into a hexadecameric structure as implied by the SARS-CoV full-length nsp7:nsp8 crystal structure. Instead our results suggest that the nsp7:nsp8 heterotetramer can dissociate into a stable dimeric unit that might bind to nsp12 in the RTC without altering nsp7-nsp8 interactions.
Substrate mediated elastic coupling between motile cells modulates inter–cell interactions and enhances cell–cell contact
Authors: Bose Subhaya , Dasbiswas Kinjal , Gopinath Arvind 
Published: March 2021

AbstractThe mechanical micro–environment of cells and tissues influences key aspects of cell structure and function including cell motility. For proper tissue development, cells need to migrate, interact with other neighbouring cells and form contacts, each of which require the cell to exert physical forces. Cells are known to exert contractile forces on underlying soft substrates. These stresses result in substrate deformation that can affect migratory behavior of cells as well as provide an avenue for cells to sense each other and coordinate their motion. The role of substrate mechanics, particularly its stiffness, in such biological processesis therefore a subject of active investigation. Recent progress in experimental techniques have enabled key insights into pairwise mechanical interactions that control cell motility when they move on compliant soft substrates. Analysis and modeling of such systemsis however still in its nascent stages. Motivated by the role modeling is expected to play in interpreting, informing and guiding experiments, we build a biophysical model for cell migration and cell–cell interactions. Our focus is on situations highly relevant to tissue engineering and regenerative medicine –when substrate traction stresses induced by motile cells enable substrate deformation and serve as a medium of communication. Using a generalizable agent–basedmodel, we compute key metrics of cell motile behavior such as the number of cell–cell contacts over a given time, dispersion of cell trajectories, and probability of permanent cell contact, and analyze how these depend on a cell motility parameter and on substrate stiffness. Our results provide a framework towards modeling the manner in which cells may sense each other mechanically via the substrate and use this information to generate coordinated movements across much longer length scales. Our results also provide a foundation to analyze experiments on the phenomenon known as durotaxis where single cells move preferentially towards regions of high stiffness on patterned substrates.
Molecular basis for SPIN·DOC-Spindlin1 engagement and its role in transcriptional inhibition
Authors: Zhao Fan , Yang Fen , Feng Fan , Peng Bo , Bedford Mark T. , Li Haitao 
Published: March 2021

ABSTRACTSpindlin1 is a transcriptional coactivator with three Tudor-like domains, of which the first and second Tudors are engaged in histone methylation readout, while the function of the third Tudor is largely unknown. Recent studies revealed that the transcriptional co-activator activity of Spindlin1 could be attenuated by SPIN•DOC. Here we solved the crystal structure of SPIN•DOC-Spindlin1 complex, revealing that a hydrophobic motif, DOCpep3 (256-281), of SPIN•DOC interacts with Tudor 3 of Spindlin1 and completes its β-barrel fold. Massive hydrophobic contacts and hydrogen bonding interactions ensure a high affinity DOCpep3-Spindlin1 engagement with a bindingKdof 30 nM. Interestingly, we characterized two more K/R-rich motifs of SPIN•DOC, DOCpep1 (187-195) and DOCpep2 (228-239), which bind to Spindlin1 at lower affinities withKdvalues of 78 μM and 31 μM, respectively. Structural and binding studies revealed that DOCpep1 and DOCpep2 competitively bind to the aromatic cage of Spindlin1 Tudor 2 that is responsible for H3K4me3 readout. Although DOCpep3-Spindlin1 engagement is compatible with histone readout, an extended SPIN•DOC fragment containing DOCpep1 and DOCpep2 inhibits histone or TCF4 binding by Spindin1 due to introduced competition. This inhibitory effect is more pronounced for weaker binding targets but not for strong ones such as H3 “K4me3-K9me3” bivalent mark. Our RT-qPCR experiment showed that the removal of the hydrophobic motif or the K/R-rich region compromised the inhibitory effects of SPIN•DOC on Spindlin1-mediated transcriptional activation. In sum, here we revealed multivalent engagement between SPIN•DOC and Spindlin1, in which a hydrophobic motif acts as the primary binding site for stable SPIN•DOC-Spindlin1 association, while two more neighboring K/R-rich motifs further modulate the target selectivity of Spindlin1 via competitive inhibition, therefore attenuating the transcriptional co-activator activities of Spindlin1 through affecting its chromatin association.
Firm performance in the financial industry: the role of foreign entrants and their origin
Authors: Nguyen Dao Thi Hong 
Published: March 2021

PurposeThis study aims to provide firm-level evidence on the relationship between the presence of financial services multinationals and indigenous counterparts’ performance, using a comprehensive sample of firms in the emerging financial industry in Vietnam.Design/methodology/approachThis study uses the generalized method of moments with instrumental variables (IV/GMM) to deal with potential endogeneity problem. Of this technique, a pragmatic approach to constructing instruments is adopted, capitalizing on the geographical and industry segmentation of the local market. The empirical analyses also address statistical issues of the overall model significance, heteroskedasticity and multicollinearity.FindingsThe regression results reveal that foreign entrants have a positive and statistically significant association with indigenous firms’ labor productivity and the average wage, with a more pronounced impact on the latter. The increased entry of financial multinationals appears to be uncorrelated with indigenous firms’ profitability. The extended estimations also suggest that investor origin matters in determining spillover magnitude. The average estimate of Asian affiliates in the examined relationship is approximately half that of European affiliates, whereas foreign entrants originating from America show an insignificant role.Originality/valueThis study sheds light on the broader impacts of foreign financial affiliates by simultaneously exploring their impacts on three key dimensions of indigenous firm performance, namely, labor productivity, average wage and profitability. This paper also enriches the existing literature by disentangling the effects of foreign entrants from different regions of origin, which was largely neglected in the context of financial services multinationals.
Using social media comments to reduce alcohol purchase intentions: An online experiment
Authors: Noel Jonathan K. 
Published: March 2021

AbstractIntroductionAlcohol advertising is prevalent on social media. The current study sought to identify effective message types to pair with social media alcohol ads to minimise purchase intentions associated with exposure.MethodsA 6 (within) × 5 (between) randomised controlled experiment was conducted with n = 723 US participants. Participants viewed six unique social media alcohol ads and were randomised to view one of four message types (i.e. pro‐drinking comments, anti‐drinking comments, industry responsibility messages and health warning labels) associated with the ads or the control (i.e. no messages). Purchase intentions were measured after each ad exposure. Significant main and interactive effects were determined by two‐level, random intercept hierarchical linear models.ResultsPurchase intentions were significantly lower among participants who viewed anti‐drinking comments relative to the control (P = 0.022) and warning labels (P = 0.016). Purchase intentions were significantly greater among participants who viewed pro‐drinking comments and had a family history of alcohol use (P = 0.032) and among those who viewed warning labels and were previously exposed to alcohol depictions through family and friends' social media posts (P = 0.033).Discussion and ConclusionsAnti‐drinking messages, written by social media users, may be effective at reducing alcohol purchase intentions when posted as social media comments. Current industry responsibility messages had no effect, and caution may be needed if warning labels are applied to ads in this medium.
Assessing liver stiffness with conventional cut‐off values overestimates liver fibrosis staging in patients who received the Fontan procedure
Authors: Cho Yuki , Kabata Daijiro , Ehara Eiji , Yamamoto Akira , Mizuochi Tatsuki , Mushiake Sotaro , Kusano Hironori , Kuwae Yuko , Suzuki Tsugutoshi , Uchida‐Kobayashi Sawako , Morikawa Hiroyasu , Amano‐Teranishi Yuga , Kioka Kiyohide , Jogo Atsushi , Isoura Yoshiharu , Hamazaki Takashi , Murakami Yosuke , Tokuhara Daisuke 
Published: March 2021

AbstractAimPatients who undergo the Fontan procedure for complex congenital heart disease are prone to liver cirrhosis. Liver stiffness (LS) reflects liver fibrosis stage in patients with chronic viral hepatitis; however, its accuracy in predicting liver fibrosis stage in Fontan patients is controversial. We aimed to clarify the correlation between LS and liver fibrosis stage in Fontan patients.MethodsFifty‐eight Fontan patients were prospectively measured for LS with transient elastography. We undertook liver biopsy, cardiac catheterization, and laboratory tests in 22 of these patients (median age, 14.7 years; range, 9.9–32.1 years) with LS > 11.0 kPa (median, 19.2 kPa; range, 12.2–39.8 kPa); these elevated LS values suggest liver cirrhosis.ResultsHistologically, all patients showed mild‐to‐severe portal and sinusoidal fibrosis but no cirrhosis. Statistically, LS did not predict histological liver fibrosis scores (p = 0.175). Liver stiffness was not correlated with central venous pressure (p = 0.456) or with the hepatic venous pressure gradient (HVPG; p = 0.062), although the p value for HVPG was only slightly above the threshold for significance.ConclusionsFontan patients are prone to developing both portal and sinusoidal fibrosis. Liver stiffness could be influenced by HVPG, and using the conventional cut‐off values for LS overestimates and overtreats liver fibrosis in these patients.
Investigating Popular Mental Health Mobile Application Downloads and Activity During the COVID-19 Pandemic
Authors: Wang Xiaomei , Markert Carl , Sasangohar Farzan 
Published: March 2021

Objective This article analyzes the changes in downloads and activity of users of select popular mental health mobile applications (mHealth apps) during coronavirus disease 2019 (COVID-19). Background The outbreak of the COVID-19 crisis has shown a negative impact on public mental health. Mobile health has the potential to help address the psychological needs of existing and new patients during the pandemic and beyond. Method Downloads data of 16 widely used apps were analyzed. The quality of apps was reviewed using the Mobile Application Rating Scale (MARS) framework. Correlation analysis was conducted to investigate the relationship between app quality and app popularity. Results Among the 16 apps, 10 were meditational in nature, 13 showed increased downloads, with 11 apps showing above 10% increase in the downloads after the pandemic started. The popular apps were satisfactory in terms of functionality and esthetics but lacked clinical grounding and evidence base. There exists a gap between app quality and app popularity. Conclusion This study provided evidence for increased downloads of mental mHealth apps (primarily meditation apps) during the COVID-19 pandemic but revealed several gaps and opportunities to address deficiencies in evidence-based design, usability and effective assessment, and integration into current workflows. Application The COVID-19 pandemic is a potential turning point for mHealth applications for mental health care. Whereas the evidence suggests a need for alternative delivery of care, human factors and ergonomics methods should be utilized to ensure these tools are user-centered, easy to use, evidence-based, well-integrated with professional care, and used sustainably.