bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impaired Layer Specific Retinal Vascular Reactivity Among Diabetic Subjects
Authors: Singer Maxwell , Ashimatey Bright S. , Zhou Xiao , Chu Zhongdi , Wang Ruikang K. , Kashani Amir H. 
Published: May 2020

AbstractPurposeTo investigate layer specific retinal vascular reactivity (RVR) in capillaries of diabetic subjects with no or mild non-proliferative diabetic retinopathy (NPDR).MethodsA previously described nonrebreathing apparatus was used to deliver room air, 5% CO2, or 100% O2to 41 controls and 22 diabetic subjects (with mild or no NPDR) while simultaneously acquiring fovea-centered 3×3mm2Swept-Source Optical Coherence Tomography Angiography. Vessel skeleton density (VSD) and vessel diameter index (VDI) were calculated for each gas condition for the superficial retinal layer (SRL) and deep retinal layer (DRL). The superficial layer analysis excluded regions of arterioles and venules. Data analysis was performed using mixed factorial analysis of covariance stratified by diabetic status. All models were adjusted for age, gender, and hypertension.ResultsAmong controls, there was a significant difference in capillary VSD between all gas conditions (p<0.001). This difference was present in both the SRL and DRL. Among diabetics, there was no significant difference in response to CO2conditions in the SRL (p=0.072), and a blunted response to both CO2and O2in the DRL. A significant gas effect was detected in the capillary VDI in the SRL of controls (p=0.001), which was driven by higher VDI in the oxygen condition compared to that of carbon dioxide.ConclusionsImpairment in RVR in diabetic subjects is driven largely by a decrease in the magnitude of the capillary response to O2in the DRL as well as almost complete attenuation of capillary CO2response in all layers. These layer and gas specific impairments in diabetics seem to occur early in the disease and to be driven primarily at the capillary level.
Cephalosporins target quorum sensing and suppress virulence ofPseudomonas aeruginosainCaenorhabditis elegansinfection model
Authors: Kumar Lokender , Brenner Nathanael , Brice John , Klein-Seetharaman Judith , Sarkar Susanta K. 
Published: May 2020

ABSTRACTPseudomonas aeruginosautilizes a chemical social networking system referred to as quorum sensing (QS) to strategically co-ordinate the expression of virulence factors and biofilm formation. Virulence attributes damage the host cells, impair the host immune system, and protect bacterial cells from antibiotic attack. Thus, anti-QS agents may act as novel anti-infective therapeutics to treatP. aeruginosainfections. The present study was performed to evaluate the anti-QS, anti-biofilm, and anti-virulence activity of β-lactam antibiotics (carbapenems and cephalosporins) againstP. aeruginosa. The anti-QS activity was quantified usingChromobacterium violaceumCV026 as a QS reporter strain. Our results showed that cephalosporins including cefepime (CP), ceftazidime (CF), and ceftriaxone (CT) exhibited potent anti-QS and anti-virulence activities againstP. aeruginosaPAO1. These antibiotics significantly impaired motility phenotypes, decreased pyocyanin production, and reduced the biofilm formation byP. aeruginosaPAO1. In the present study, we studied isogenic QS mutants of PAO1: ΔLasR, ΔRhlR, ΔPqsA, and ΔPqsR and found that the levels of virulence factors of antibiotic-treated PAO1 were comparable to QS mutant strains. Molecular docking predicted high binding affinities of cephalosporins for the ligand-binding pocket of QS receptors (CviR, LasR, and PqsR). In addition, our results showed that the anti-microbial activity of aminoglycosides increased in the presence of sub-inhibitory concentrations (sub-MICs) of CP againstP. aeruginosaPAO1. Further, utilizingCaenorhabditis elegansas an animal model for thein vivoanti-virulence effects of antibiotics, cephalosporins showed a significant increase inC. eleganssurvival by suppressing virulence factor production inP. aeruginosa. Thus, our results indicate that cephalosporins might provide a viable anti-virulence therapy in the treatment of infections caused by multi-drug resistantP. aeruginosa.
SR7 - a dual function antisense RNA fromBacillus subtilis
Authors: Haq Inam Ul , Müller Peter , Brantl Sabine 
Published: May 2020

SummaryHere, we describe SR7, a dual-function antisense RNA from theBacillus subtilischromosome. This RNA was earlier published as the SigB-dependent regulatory RNA S1136 and reported to reduce the amount of the small ribosomal subunit under ethanol stress. We found that the 5’ portion of SR7 encodes a small protein composed of 39 amino acids which we designated SR7P. It is translated from a 185 nt SigB-dependent mRNA under five different stress conditions and a longer SigB-independent RNA constitutively. Two- to three-fold higher amounts of SR7P were detected inB. subtiliscells exposed to salt, ethanol or heat stress. Co-elution experiments with SR7PC-FLAGand Far-Western blotting demonstrated that SR7P interacts with the glycolytic enzyme enolase. Enolase is a scaffolding component of theB. subtilisdegradosome where it interacts with RNase Y and phosphofructokinase PfkA. We found that SR7P increases the amount of RNase Y bound to enolase without affecting PfkA. RNA does not bridge the SR7P-enolase-RNase Y interaction.In vitro-degradation assays with the known RNase Y substratesyitJandrpsOmRNA revealed enhanced enzymatic activity of enolase-bound RNase Y in the presence of SR7P. Northern blots showed a major effect of enolase and a minor effect of SR7P on the half-life ofrpsOmRNA indicating a fine-tuning role of SR7P in RNA degradation. Moreover, SR7P impacts survival ofB. subtilisunder stress conditions. We suggest that the SR7P-dependent modification of the degradosome affects targets in different physiological pathways.
Structural analysis of the SARS-CoV-2 methyltransferase complex involved in coronaviral RNA cap creation
Authors: Krafcikova Petra , Silhan Jan , Nencka Radim , Boura Evzen 
Published: May 2020

AbstractCOVID-19 pandemic is caused by the SARS-CoV-2 virus that has several enzymes that could be targeted by antivirals including a 2’-O RNA methyltransferase (MTase) that is involved in the viral RNA cap formation; an essential process for RNA stability. This MTase is composed of two nonstructural proteins, the nsp16 catalytic subunit and the activating nsp10 protein. We have solved the crystal structure of the nsp10-nsp16 complex bound to the pan-MTase inhibitor sinefungin in the active site. Based on the structural data we built a model of the MTase in complex with RNA that illustrates the catalytic reaction. A structural comparison to the Zika MTase revealed low conservation of the catalytic site between these two RNA viruses suggesting preparation of inhibitors targeting both these viruses will be very difficult. Together, our data will provide the information needed for structure-based drug design.
Regulation by the Pitcher Plant Sarracenia purpurea of the Structure of its Inquiline Food Web
Authors: Ellison Aaron M. , Gotelli Nicholas J. , Błędzki Leszek A. , Butler Jessica L. 
Published: May 2020

AbstractPhytotelmata, the water-filled habitats in pitcher plants, bromeliad tanks, and tree-holes, host multitrophic food webs that are model experimental systems for studying food-web structure and dynamics. However, the plant usually is considered simply as an inert container, not as an interacting part of the food web. We used a manipulative field experiment with a response-surface design to determine effects of nutrient enrichment (multiple levels of NH4NO3, PO4, and captured prey), top predator (removed or present), and the plant itself (with or without plastic tubes inserted into the pitchers to isolate the food web from the plant) on the macrobial food web within the modified leaves (“pitchers”) of the carnivorous pitcher plantSarracenia purpurea. Connection to the plant, addition of NH4NO3and removal of the top predator significantly increased the food web’s saturation, defined as its trophic depth and number of interactions. No effects on food-web saturation resulted from addition of PO4or supplemental prey. Plants such asS. purpureathat create phytotelmata are more than inert containers and their inhabitants are more than commensal inquilines. Rather, both the plant and the inquilines are partners in a complex network of interactions.
Substrate Resistance to Traction Forces Controls Fibroblast Polarization
Authors: Missirlis D. , Haraszti T. , Heckmann L. , Spatz J. P. 
Published: May 2020

AbstractThe mechanics of fibronectin-rich extracellular matrix regulate cell physiology in a number of diseases, prompting efforts to elucidate cell mechanosensing mechanisms at the molecular and cellular scale. Here, the use of fibronectin-functionalized silicone elastomers that exhibit considerable frequency-dependence in viscoelastic properties unveiled the presence of two cellular processes that respond discreetly to substrate mechanical properties. Soft elastomers supported efficient focal adhesion maturation and fibroblast spreading due to an apparent stiff surface layer. However, soft elastomers did not enable cytoskeletal and fibroblast polarization; elastomers with high cross-linking and low deformability were required for polarization. The underlying reason for this behavior was the inability of soft elastomeric substrates to resist traction forces, rather than a lack of sufficient traction force generation; accordingly, mild inhibition of actomyosin contractility rescued fibroblast polarization even on the softer elastomers. Our findings help reconcile previously proposed local and global models of cell mechanosensing by demonstrating the differential dependence of substrate mechanics on distinct cellular processes.Statement of SignificanceThe mechanisms cells employ to sense and respond to the mechanical properties of their surroundings remain incompletely understood. In this study we used a commercial silicone elastomer formulation to prepare compliant, fibronectin-coated substrates and investigate the adhesion and polarization of human fibroblasts. Our results suggest the existence of at least two discrete mechanosensing processes regulated at different time and length (force) scales. Focal adhesion assembly and cell spreading were promoted by a stiff surface layer independent from bulk viscoelasticity, whereas effective cell polarization required elevated elastomer stiffness, sufficient to resist applied cell traction. The results presented here have implications on the use of elastomeric substrates as biomaterials for mechanosensing studies or clinical applications.
Yeast-Expressed SARS-CoV Recombinant Receptor-Binding Domain (RBD219-N1) Formulated with Aluminum Hydroxide Induces Protective Immunity and Reduces Immune Enhancement
Authors: Chen Wen-Hsiang , Tao Xinrong , Agrawal Anurodh , Algaissi Abdullah , Peng Bi-Hung , Pollet Jeroen , Strych Ulrich , Bottazzi Maria Elena , Hotez Peter J. , Lustigman Sara , Du Lanying , Jiang Shibo , Tseng Chien-Te K. 
Published: May 2020

AbstractWe developed a severe acute respiratory syndrome (SARS) subunit recombinant protein vaccine candidate based on a high-yielding, yeast-engineered, receptor-binding domain (RBD219-N1) of the SARS beta-coronavirus (SARS-CoV) spike (S) protein. When formulated with Alhydrogel®, RBD219-N1 induced high-level neutralizing antibodies against both pseudotyped virus and a clinical (mouse-adapted) isolate of SARS-CoV. Here, we report that mice immunized with RBD219-N1/Alhydrogel® were fully protected from lethal SARS-CoV challenge (0% mortality), compared to ∼ 30% mortality in mice when immunized with the SARS S protein formulated with Alhydrogel®, and 100% mortality in negative controls. An RBD219-N1 formulation Alhydrogel® was also superior to the S protein, unadjuvanted RBD, and AddaVax (MF59-like adjuvant)-formulated RBD in inducing specific antibodies and preventing cellular infiltrates in the lungs upon SARS-CoV challenge. Specifically, a formulation with a 1:25 ratio of RBD219-N1 to Alhydrogel® provided high neutralizing antibody titers, 100% protection with non-detectable viral loads with minimal or no eosinophilic pulmonary infiltrates. As a result, this vaccine formulation is under consideration for further development against SARS-CoV and potentially other emerging and re-emerging beta-CoVs such as SARS-CoV-2.
Optical control of ERK and AKT signaling promotes axon regeneration and functional recovery of PNS and CNS inDrosophila
Authors: Wang Qin , Fan Huaxun , Li Feng , Skeeters Savanna S. , Krishnamurthy Vishnu , Song Yuanquan , Zhang Kai 
Published: May 2020

AbstractNeuroregeneration is a dynamic process synergizing the functional outcomes of multiple signaling circuits. Channelrhodopsin-based optogenetics shows feasibility of stimulating neural repair but does not pin down specific signaling cascades. Here, we utilized optogenetic systems, optoRaf and optoAKT, to delineate the contribution of the ERK and AKT signaling pathways to neuroregeneration in liveDrosophilalarvae. We showed that optoRaf or optoAKT activation not only enhanced axon regeneration in both regeneration competent and incompetent sensory neurons in the peripheral nervous system, but also allowed temporal tuning and proper guidance of axon regrowth. Furthermore, optoRaf and optoAKT differ in their signaling kinetics during regeneration, showing a gated versus graded response, respectively. Importantly in the central nervous system, their activation promotes axon regrowth and functional recovery of the thermonociceptive behavior. We conclude that non-neuronal optogenetics target damaged neurons and signaling subcircuits, providing a novel strategy in the intervention of neural damage with improved precision.
Evolutionary Changes in Left-Right Visceral Asymmetry inAstyanaxCavefish
Authors: Ma Li , Ng Mandy , Shi Janet , Gore Aniket V. , Castranova Daniel , Weinstein Brant M. , Jeffery William R. 
Published: May 2020

SummaryVertebrates show conserved left-right (L-R) asymmetry of internal organs controlled by Nodal-Pitx2/Lefty signaling [1-3]. Modifications in L-R asymmetry occur in mutants [4] and rarely in humans [5], but little is known about natural L-R changes during evolution. Here we describe changes in L-R asymmetry inAstyanax mexicanus, a teleost with ancestral surface (surface fish) and derived cave (cavefish) morphs [6]. In teleosts, Nodal-Pitx2 signaling is activated in the left lateral plate mesoderm (LPM), the cardiac tube jogs to the left and loops to the right (D-looping), and the liver and pancreas form on opposite sides of the midline. Surface fish show conventional L-R patterning, but cavefish can show Nodal-Pitx2 expression in the right LPM or bilaterally, left (L)-looping hearts, and reversed liver and pancreas asymmetry, and these reversals have no effect on survival. The Lefty1 Nodal antagonist is expressed along the surface fish and cavefish midlines, but expression of the Lefty2 antagonist is absent in the LPM of most cavefish embryos, suggesting a role forlefty2(lft2) in changing organ asymmetry. Although CRISPR-Cas9lft2editing affected D-looping in surface fish, the cavefishlft2gene showed no coding mutations, and was expressed normally during cavefish gastrulation, suggesting downregulation by regulatory changes. Reciprocal hybridization, the fertilization of cavefish eggs with surface fish sperm andvice versa, indicated that the change in cavefish L-R asymmetry is a maternal genetic effect. Our studies reveal natural changes in internal organ asymmetry during evolution and introduceA. mexicanusas a new model to study the underlying mechanisms.
BioVizConnect: Web application linking CyVerse cloud resources to genomic visualization in the Integrated Genome Browser
Authors: Raveendran Karthik , Freese Nowlan H , Kintali Chaitanya , Tiwari Srishti , Bole Pawan , Dias Chester , Loraine Ann E 
Published: May 2020

AbstractGenomics researchers do better work when they can interactively explore and visualize data. However, due to the vast size of experimental datasets, researchers are increasingly using powerful, cloud-based systems to process and analyze data. These remote systems, called science gateways, offer user-friendly, Web-based access to high performance computing and storage resources, but typically lack interactive visualization capability. In this paper, we present BioVizConnect, a middleware Web application that links the CyVerse science gateway to the Integrated Genome Browser (IGB), a highly interactive native application implemented in Java that runs on the user’s personal computer. Using BioVizConnect, users can (i) stream data from the CyVerse data store into IGB for visualization, (ii) improve the IGB user experience for themselves and others by adding IGB specific metadata to CyVerse data files, including genome version and track appearance, and (iii) run compute-intensive visual analytics functions on CyVerse infrastructure to create new datasets for visualization in IGB or other applications. To demonstrate how BioVizConnectfacilitates interactive data visualization, we describe an example RNA-Seq data analysis investigating how heat and desiccation stresses affect gene expression in the model plantArabidopsis thaliana. Lastly, we discuss limitations of the technologies used and suggest opportunities for future work. BioVizConnectis available fromhttps://bioviz.org.
The architecture of EMC reveals a path for membrane protein insertion
Authors: O’Donnell John P. , Phillips Ben P. , Yagita Yuichi , Juszkiewicz Szymon , Wagner Armin , Malinverni Duccio , Keenan Robert J. , Miller Elizabeth A. , Hegde Ramanujan S. 
Published: May 2020

AbstractApproximately 25% of eukaryotic genes code for integral membrane proteins that are assembled at the endoplasmic reticulum. An abundant and widely conserved multi-protein complex termed EMC has been implicated in membrane protein biogenesis, but its mechanism of action is poorly understood. Here, we define the composition and architecture of human EMC using biochemical assays, crystallography of individual subunits, site-specific photocrosslinking, and cryo-EM reconstruction. Our results show that EMC’s cytosolic domain contains a large, moderately hydrophobic vestibule that binds a substrate’s transmembrane domain (TMD). The cytosolic vestibule leads into a lumenally-sealed, lipid-exposed intramembrane groove large enough to accommodate a single substrate TMD. A gap between the cytosolic vestibule and intramembrane groove provides a path for substrate egress from EMC. These findings suggest how EMC facilitates energy-independent membrane insertion of TMDs, explain why only short lumenal domains are translocated by EMC, and constrain models of EMC’s proposed chaperone function.
Spinal motoneurones are intrinsically more responsive in the adult G93A SOD1 mouse model of Amyotrophic Lateral Sclerosis
Authors: Jensen D.B. , Kadlecova M. , Allodi I. , Meehan C.F. 
Published: May 2020

AbstractIn vitrostudies from transgenic Amyotrophic Lateral Sclerosis models have suggested an increased excitability of spinal motoneurones. However,in vivointracellular recordings from adult ALS mice models have produced conflicting findings. Previous publications using barbiturate anaesthetised G93A SOD1 mice suggested that some motoneurones are hypo-excitable, defined by deficits in repetitive firing. Our own previous recordings in G127X SOD1 mice using different anaesthesia, however, showed no repetitive firing deficits, and increased persistent inward currents at symptom onset. These discrepancies may be due to differences between models, symptomatic stage, anaesthesia or technical differences. To investigate this, we repeated our original experiments, but in adult male G93A mice at both presymptomatic and symptomatic stages, under barbiturate anaesthesia.In vivointracellular recordings from antidromically identified spinal motoneurones revealed no significant differences in the ability to fire repetitively in the G93A SOD1 mice. Motoneurones in G93A SOD1 mice fired significantly more spontaneous action potentials. Rheobase was significantly lower and the input resistance and input-output gain were significantly higher in both presymptomatic and symptomatic G93A SOD1 mice. This was despite a significant increase in the duration of the post-spike after-hyperpolarisation (AHP) in both presymptomatic and symptomatic G93A SOD1 mice. Finally, evidence of increased activation of persistent inward currents was seen in both presymptomatic and symptomatic G93A SOD1 mice. Our results do not confirm previous reports of hypo-excitability of spinal motoneurones in the G93A SOD1 mouse and demonstrate that the motoneurones do in fact show an increased response to inputs.Key Point SummaryAlthoughin vitrorecordings using neonatal preparations from mouse models of Amyotrophic Lateral Sclerosis (ALS) suggest increased motoneurone excitability,in vivorecordings in adult ALS mouse models have been conflicting.In adult G93A SOD1 models, spinal motoneurones have previously been shown to have deficits in repetitive firing, in contrast to the G127X SOD1 mouse model.Ourin vivointracellular recordings in barbiturate-anaesthetised adult male G93A SOD1 mice reveal no deficits in repetitive firing either prior to or after symptom onset.We show that deficits in repetitive firing ability can be a consequence of experimental protocol and should not be used alone to classify otherwise normal motoneurones as hypo-excitable.Motoneurones in the G93A SOD1 mice showed an increased response to inputs, with lower rheobase, higher input-output gains and increased activation of persistent inward currents.
Productivity or illusion? Assessing employees' behavior in an employability paradox
Authors: Imam Hassan , Chambel Maria José 
Published: May 2020

PurposeEmployability has been studied in different disciplines (e.g. occupational health and career) and has been seen as a personal resource with overall positive outcomes. The present research investigates the behavioral implications of (perceived) employability and responds to the recent call of research that perceived employability could have not only positive but also negative behavioral implications. Furthermore, this study aims to reduce the asymmetry of data set and replication of existing results in non-Western economies.Design/methodology/approachMultinationals were taken as context to test the hypotheses, and a sample of 230 white-collar employees was drawn from fast-moving consumer goods companies. Partial least square–structural equation modeling through SmartPLS was used to analyze the data.FindingsIn light of social exchange theory, the present research identified the dark side of employability, which may impair the employer–employee relationship. Perceived employability did not relate significantly with in-role performance, nor did it correlate with organizational citizenship behavior, that is, a discretionary behavior promotes the efficient and effective functioning. However, perceived employability had a positive significant relationship with OCBI, that is, helping supervisors and coworkers with heavy workloads, as well as with counterproductive behaviors.Practical implicationsEmployable workers have always been considered key players and an asset for organizations due to their high productivity skills. A balanced employer–employee relationship creates a mutual win; therefore, a carefully drafted human resources policy may help organizations to fulfill the needs of employable workers and reap optimal benefits in terms of productivity. Behavioral training to supervisors/managers may help to assertively deal with employees' negative behavior without further escalation.Originality/valueThe present study suggests a paradoxical perspective in employability – a behavior debate, which is in an initial phase where it is difficult to determine whether employable workers are productive to the organizations or not.