bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physiological alterations in microglial morphology associate with the sleep-wake cycle in a brain region-specific manner
Authors: Steffens Sarah Katharina , Stenberg Tarja Helena , Wigren Henna-Kaisa 
Published: March 2022

AbstractLong-term total sleep deprivation induces changes in cortical - and hippocampal microglial morphology that closely resemble the microglial response to the gram-negative bacterial cell wall component lipopolysaccharide (LPS). A recent study found evidence that microglia could modify vigilance-states/sleep, but only few studies investigated microglial throughout the diurnal behavioral inactivity/activity pattern or the naturally occurring sleep-wake cycle, and those who have, only concentrated on the cortical or hippocampal microglia. As microglia demonstrate regional heterogeneity, we compared microglial diurnal morphological alterations in the somatosensory cortex (SC) and dorsal hippocampus (HC) to the basal forebrain (BF), which is a subcortical brain area involved in the regulation of vigilance states.We collected mouse brain samples every 3h throughout the 24h light-dark-cycle and applied a 3D reconstruction method for the acquired confocal microscopy images for each brain area separately. While microglial regional heterogeneity was evident, stimulation of microglia with LPS caused comparable microglial responses in all brain areas. When comparing microglial features between the 12h light- and dark periods, regional heterogeneity re-appeared. As most of the morphological alterations occurred during the light period-the habitual sleeping period of the mice, we performed polysomnography to study the possible interaction of microglial morphology and sleep. We found that cortical-, but not HC- or BF microglial territory and volume negatively correlated with sleep slow wave activity (SWA), an electroencephalic feature of non-REM sleep (NREMS). Since microglia are sensitive to neuronal activity, we propose that the regional differences reflect vigilance-state specific neuronal activity patterns.Table of contents imageMain PointsMicroglia show morphological differences between the somatosensory cortex (SC), hippocampus (HC) and basal forebrain (BF) under physiological conditions.Cortical-, but not HC- or BF microglial cell volume negatively correlates with non-REM sleep slow wave activity.
Blinding efficacy and adverse events following repeated transcranial alternating current, direct current, and random noise stimulation
Authors: Sheffield James G. , Ramerpresad Sumientra , Brem Anna-Katharine , Mansfield Karen , Orhan Umut , Dillard Michael , McKanna James , Plessow Franziska , Thompson Todd , Santarnecchi Emiliano , Pascual-Leone Alvaro , Pavel Misha , Mathan Santosh , Kadosh Roi Cohen 
Published: March 2022

AbstractAs transcranial electrical stimulation (tES) protocols advance, assumptions underlying the technique need to be retested to ensure they still hold. Whilst the safety of stimulation has been demonstrated mainly for a small number of sessions, and small sample size, adverse events (AEs) following multiple sessions remain largely untested. Similarly, whilst blinding procedures are typically assumed to be effective, the effect of multiple stimulation sessions on the efficacy of blinding procedures also remains under question. This is especially relevant in multisite projects where small unintentional variations in protocol could lead to inter-site difference. We report AE and blinding data from 1,019 participants who received up to 11 semi-consecutive sessions of active or sham transcranial alternating current stimulation (tACS), direct current stimulation (tDCS), and random noise stimulation (tRNS), at 4 sites in the UK and US. We found that AEs were often best predicted by factors other than tES, such as testing site or session number. Results from the blinding analysis suggested that blinding was less effective for tDCS and tACS than tRNS. The occurrence of AEs did not appear to be linked to tES despite the use of smaller electrodes or repeated delivery. However, blinding efficacy was impacted in tES conditions with higher cutaneous sensation, highlighting a need for alternative stimulation blinding protocols. This may be increasingly necessary in studies wishing to deliver stimulation with higher intensities.
A mass spectrometry-based method for the determination ofin vivobiodistribution of tumor targeting small molecule-metal conjugates
Authors: Gilardoni Ettore , Zana Aureliano , Galbiati Andrea , Sturm Theo , Millul Jacopo , Cazzamalli Samuele , Neri Dario , Stucchi Riccardo 
Published: March 2022

AbstractNuclear medicine plays a key role in modern diagnosis and cancer therapy. The development of tumor targeting radionuclide conjugates (also named Small Molecule-Radio Conjugates - SMRCs) represents a significant improvement over the clinical use of metabolic radiotracers (e.g., [18F]-Fluorodeoxyglucose) for imaging and over the application of biocidal external beam radiations for therapy. During the discovery of SMRCs, molecular candidates must be carefully evaluated typically by performing biodistribution assays in preclinical tumor models. Quantification methodologies based on radioactive counts are typically demanding due to safety concerns, availability of radioactive material, and infrastructures. In this article, we report the development of a mass spectrometry (MS)-based method for the detection and quantification of small molecule-metal conjugates (SMMCs) as cold surrogates of SMRCs. We applied this methodology for the evaluation of the biodistribution of a particular class of tumor-targeting drug candidates based onnatLu,natGa,natF and directed against Fibroblast Activation Protein (FAP). The reliability of the LC-MS analysis was validated by direct comparison of MSbased and radioactivity-based biodistribution data. Results show that MS biodistribution of stable isotope metal conjugates is an orthogonal tool for the preclinical characterization of different classes of radiopharmaceuticals.
Flipped elevational pattern of pollination mode in tropical vs. temperate Americas
Authors: Dellinger Agnes S. , Hamilton Ashley M. , Wessinger Carolyn A. , Smith Stacey 
Published: March 2022

AbstractAimAbiotic factors, such as temperature and precipitation, vary markedly along elevational gradients, and can in turn, shape key biotic interactions, such as herbivory and pollination. Despite the well-known effects of climatic conditions on pollinator activity and efficiency, we know little about the role of climate in pollinator shifts in animal-pollinated plants at broad geographic scales. Here we investigate patterns of altitudinal turnover in pollination mode across the Americas, with a focus on the most common pollinators (bees and hummingbirds). Specifically, we test Cruden’s classic hypothesis that plants are likely to shift to bird pollination at high elevations because endothermic pollinators are more reliable in cold and rainy conditions.LocationAmericasTime periodCurrentMajor taxa studied2232 plant taxa from 26 cladesMethodsWe collated information on pollination mode (1262 insect-pollinated, 970 vertebrate-pollinated) for the study taxa from the literature, and used GBIF occurrence data to estimate median distributions and bioclimatic attributes of each species. We used (phylogenetic) GLMMs to test for associations between pollination mode and ecogeographic variables.ResultsTo our surprise, we found flipped elevational patterns of insect- and vertebrate-pollination strategies across latitudes, with vertebrate pollination dominating at high elevations in the tropics, but not in temperate zones. We term this pattern the ‘Tropical flip’. We recovered a strong association of vertebrate-pollinated plants with moist, forested habitats across latitudes, while insect-pollinated plants were often found in cool and dry or warm and moist conditions.Main conclusionsAltitudinal gradients in temperature may not serve as a universal explanation for shifts among endothermic insect and ectothermic vertebrate pollination. Instead, strong abiotic niche differentiation among insect- and vertebrate-pollinated plants, along with competition for pollination niche space, has likely shaped the ‘tropical flip’.
Crippled Coronavirus: 5’-PolyU targeted Oligo prevents development of infectious Virions
Authors: Ullah Hemayet , Averick Saadyah , Tang Qiyi 
Published: March 2022

AbstractCurrent RNA viral pandemic of COVID-19 has been worsened by rapidly spreading viral variants. To inhibit mutation-based development of new escape variants, elements that are indispensable for the virus may be targeted. The 5’-polyU tract of the antigenome offers one such target. Host cells do not harbor 5’-polyU tracts on any of their transcripts, making the tract an attractive virus-specific target. We hypothesize that inhibiting the 5’-polyU by complementary oligonucleotide can limit the use of the tract as template for virus to generate 3’ polyA tails of RNA viruses. Here, we used a frameshift-inducing DNA oligonucleotide with 3’ polyAs to target the 5’-polyU tract of mouse coronavirus (MHV-A59). Results from assays for double stranded RNA (dsRNA) synthesis, infectivity of released virions, and syncytium formation indicate that the oligonucleotide treatment prevented generation of infectious virions. Our results show a unique mode of action of the designed 3’-polyA oligonucleotide against mouse coronavirus which leaves host cells unaffected. This strategy can be adopted for the development of novel classes of oligonucleotide-based drugs that inhibit the production of infectious RNA viruses, including the coronaviruses. Since the 5’-polyU tract is conserved and is essential for variants of coronaviruses, this strategy can potentially address coronavirus variant emergence as well.
Meta-analysis and experimental re-evaluation of the Boyle van ‘t Hoff relation with osmoregulation modelled by linear elastic principles and ion-osmolyte leakage
Authors: Olver Dominic J , Azam Iqra , Benson James D 
Published: March 2022

ABSTRACTIn this study we challenge the paradigm of using the Boyle van ’t Hoff (BvH) relation to relate cell size as a linear function of inverse extracellular osmotic pressure for short time periods (~5 to 30 mins). We present alternative models that account for mechanical resistance (turgor model) and ion-osmolyte leakage (leak model), which is not accounted for by the BvH relation. To test the BvH relation and the alternative models, we conducted a meta-analysis of published BvH datasets, as well as new experiments using a HepG2 cell line. Our meta-analysis showed that the BvH relation may be assumed of the hypertonic region but cannot be assumed a priori over the hyper- and hypotonic region. Both alternative models perform better than the BvH relation but are nearly indistinguishable when plotted. The return to isotonic conditions plot indicated neither alternative model accurate predicts return volumes for HepG2 cells. However, a combined turgor-leak model accurately predicts both the BvH plot and the return to isotonic conditions plot. Moreover, this turgor-leak model provides a facile method to estimate the membrane-cortex Young’s modulus and the cell membrane permeability to intracellular ions/osmolytes during periods of osmotic challenge, and predicts a novel passive method of volume regulation without the need for ion pumps.
Discovery of Potent Pyrazoline-Based Covalent SARS-CoV-2 Main Protease Inhibitors
Authors: Moon Patrick , Boike Lydia , Dovala Dustin , Henning Nathaniel J. , Knapp Mark , Spradlin Jessica N. , Ward Carl C. , Wolleb Helene , Zammit Charlotte M. , Fuller Daniel , Blake Gabrielle , Murphy Jason P. , Wang Feng , Lu Yipin , Moquin Stephanie A. , Tandeske Laura , Hesse Matthew J. , McKenna Jeffrey M. , Tallarico John A. , Schirle Markus , Toste F. Dean , Nomura Daniel K. 
Published: March 2022

AbstractWhile vaccines and antivirals are now being deployed for the current SARS-CoV-2 pandemic, we require additional antiviral therapeutics to not only effectively combat SARS-CoV-2 and its variants, but also future coronaviruses. All coronaviruses have relatively similar genomes that provide a potential exploitable opening to develop antiviral therapies that will be effective against all coronaviruses. Among the various genes and proteins encoded by all coronaviruses, one particularly “druggable” or relatively easy-to-drug target is the coronavirus Main Protease (3CLpro or Mpro), an enzyme that is involved in cleaving a long peptide translated by the viral genome into its individual protein components that are then assembled into the virus to enable viral replication in the cell. Inhibiting Mpro with a small-molecule antiviral would effectively stop the ability of the virus to replicate, providing therapeutic benefit. In this study, we have utilized activity-based protein profiling (ABPP)-based chemoproteomic approaches to discover and further optimize cysteine-reactive pyrazoline-based covalent inhibitors for the SARS-CoV-2 Mpro. Structure-guided medicinal chemistry and modular synthesis of di- and tri-substituted pyrazolines bearing either chloroacetamide or vinyl sulfonamide cysteine-reactive warheads enabled the expedient exploration of structure-activity relationships (SAR), yielding nanomolar potency inhibitors against Mpro from not only SARS-CoV-2, but across many other coronaviruses. Our studies highlight promising chemical scaffolds that may contribute to future pan-coronavirus inhibitors.
ALS-linked KIF5A ΔExon27 mutant causes neuronal toxicity through gain of function
Authors: Pant Devesh C. , Parameswaran Janani , Rao Lu , Shi Liang , Chilukuri Ganesh , McEachin Zachary T. , Glass Jonathan , Bassell Gary J. , Gennerich Arne , Jiang Jie 
Published: March 2022

AbstractMutations in the human kinesin family member 5A (KIF5A) gene were recently identified as a genetic cause of amyotrophic lateral sclerosis (ALS). Several KIF5A ALS variants cause exon 27 skipping and produce motor proteins with an altered C-terminal tail (referred to as ΔExon27). However, the underlying pathogenic mechanism is still unknown. In this study, we performed a comprehensive analysis of ΔExon27 at the single-molecule, cellular, and organism levels. Our results show that ΔExon27 is prone to form cytoplasmic aggregates and is neurotoxic. The mutation relieves motor autoinhibition and increases motor self-association, leading to drastically enhanced processivity on microtubules. Finally, ectopic expression of ΔExon27 in Drosophila melanogaster causes wing defects, motor impairment, paralysis and premature death. Our results suggest gain of function as an underlying disease mechanism in KIF5A-associated ALS.
Characterization of Hydrophobic Interactions of SARS-CoV-2 and MERS-CoV Spike Protein Fusion Peptides Using Single Molecule Force Measurements
Authors: Qiu Cindy , Whittaker Gary R. , Gellman Samuel H. , Daniel Susan , Abbott Nicholas L. 
Published: March 2022

ABSTRACTWe address the challenge of understanding how hydrophobic interactions are encoded by fusion peptide sequences within coronavirus (CoV) spike proteins. Within the fusion peptides of SARS-CoV-2 and MERS-CoV, a largely conserved peptide sequence called FP1 (SFIEDLLFNK and SAIEDLLFDK in SARS-2 and MERS, respectively) has been proposed to play a key role in encoding hydrophobic interactions that drive viral-host cell membrane fusion. While a non-polar triad (LLF) is common to both FP1 sequences, and thought to dominate the encoding of hydrophobic interactions, FP1 from SARS and MERS differ in two residues (Phe 2 versus Ala 2 and Asn 9 versus Asp 9, respectively). Here we explore if single molecule force measurements can quantify hydrophobic interactions encoded by FP1 sequences, and then ask if sequence variations between FP1 from SARS and MERS lead to significant differences in hydrophobic interactions. We find that both SARS-2 and MERS wild-type FP1 generate measurable hydrophobic interactions at the single molecule level, but that SARS-2 FP1 encodes a substantially stronger hydrophobic interaction than its MERS counterpart (1.91 ± 0.03 nN versus 0.68 ± 0.03 nN, respectively). By performing force measurements with FP1 sequences with single amino acid substitutions, we determine that a single residue mutation (Phe 2 versus Ala 2) causes the almost threefold difference in the hydrophobic interaction strength generated by the FP1 of SARS-2 versus MERS, despite the presence of LLF in both sequences. Infrared spectroscopy and circular dichroism measurements support the proposal that the outsized influence of Phe 2 versus Ala 2 on the hydrophobic interaction arises from variation in the secondary structure adopted by FP1. Overall, these insights reveal how single residue diversity in viral fusion peptides, including FP1 of SARS-CoV-2 and MERS-CoV, can lead to substantial changes in intermolecular interactions proposed to play a key role in viral fusion, and hint at strategies for regulating hydrophobic interactions of peptides in a range of contexts.SIGNIFICANCEFusion of coronaviruses (CoVs) and host cells is mediated by the insertion of the fusion peptide (FP) of the viral spike protein into the host cell membrane. Hydrophobic interactions between FPs with their host cell membranes regulate the viral membrane fusion process and are key to determining infection ability. However, it is not fully understood how the amino acid sequences in FPs mediate hydrophobic interactions. We use single-molecule force measurements to characterize hydrophobic interactions of FPs from SARS-CoV-2 and MERS-CoV. Our findings provide insight into the mechanisms by which the amino acid composition of FPs encodes hydrophobic interactions and their implications for fusion activity critical to the spread of infection.
Behavioral differences among domestic cats in the response to cat-attracting plants and their volatile compounds reveal a potential distinct mechanism of action for actinidine
Authors: Bol Sebastiaan , Scaffidi Adrian , Bunnik Evelien M. , Flematti Gavin R. 
Published: March 2022

AbstractIt has been known for centuries that cats respond euphorically to Nepeta cataria (catnip). Recently, we have shown that Lonicera tatarica (Tatarian honeysuckle), Actinidia polygama (silver vine) and Valeriana officinalis (valerian) can also elicit this “catnip response”. The aim of this study was to learn if the behavior seen in response to these plants is similar to the response to catnip. Furthermore, we studied if these responses are fixed or if there are differences between cats. While nepetalactone was identified decades ago as the molecule responsible for the “catnip response”, we know that this volatile is found almost exclusively in catnip. Therefore, we also aimed to identify other compounds in these alternative plants that can elicit the blissful behavior in cats. Bioassays with 6 cats were performed in a stress-free environment, where 6 plants and 13 single compounds were each tested for at least 100 and 17 hours, respectively. All responses were video recorded and BORIS software was used to analyze the cats’ behavior. Both response duration and behavior differed significantly between the cats. While individual cats had preferences for particular plants, the behavior of individual cats was consistent among all plants. About half a dozen lactones similar in structure to nepetalactone were able to elicit the “catnip response”, as were the structurally more distinct molecules actinidine and dihydroactinidiolide. Most cats did not respond to actinidine, whereas those who did, responded longer to this volatile than any of the other secondary plant metabolites, and different behavior was observed. Interestingly, dihydroactinidiolide was also found in excretions and secretions of the red fox, making this the first report of a compound produced by a mammal, that can elicit the “catnip response”. A range of different cat-attracting compounds was detected by chemical analysis of plant materials but differences in cat behavior could not be directly related to differences in chemical composition of the plants. Together with among other results of habituation / dishabituation experiments, this indicates that additional cat-attracting compounds may be present in the plant materials that remain to be discovered. Collectively, these findings suggest that both the personality of the cat and genetic variation in the genes encoding olfactory receptors may play a role in how cats respond to cat-attracting plants. Furthermore, the data suggest a potential distinct mechanism of action for actinidine.
Lack of robust evidence for aWolbachiainfection inAnopheles gambiaefrom Burkina Faso
Authors: Sawadogo Simon P. , Kabore Didier A. , Tibiri Ezechiel B. , Hughes Angela , Gnankine Olivier , Quek Shannon , Diabaté Abdoulaye , Ranson Hilary , Hughes Grant L. , Dabiré Roch K. 
Published: March 2022

AbstractThe endosymbiontWolbachiacan have major effects on the reproductive fitness, and vectorial capacity of host insects and may provide new avenues to control mosquito borne pathogens.Anopheles gambiaes.l is the major vector of malaria in Africa but the use ofWolbachiain this species has been limited by challenges in establishing stable transinfected lines and uncertainty around native infections. High frequencies of infection ofWolbachiahave been previously reported inAn. gambiaecollected from the Valle du Kou region of Burkina Faso in 2011 and 2014. Here we re-evaluated the occurrence ofWolbachiain natural samples, collected from Valle du Kou over a 12-year time span, and in addition, expanded sampling to other sites in Burkina Faso. Our results showed that, in contrast to earlier reports,Wolbachiais present at an extremely low prevalence in natural population ofAn. gambiae. From 5,341 samples analysed only 29 were positive forWolbachiaby nested PCR representing 0.54% of prevalence. No positive samples were found with regular PCR. Phylogenetic analysis of 16S rRNA gene amplicons clustered across supergroup B, with some having similarity to sequences previously found inAnophelesfrom Burkina Faso. However, we cannot discount the possibility that the amplicon positive samples we detected were due to environmental contamination or were false positives. Regardless, the lack of a prominent native infection inAn. gambiaes.l. is encouraging for applications utilisingWolbachiatraninsfected mosquitoes for malaria control.
Cell size asymmetries in the sea star embryo
Authors: Barone Vanessa , Byrne Maria , Lyons Deirdre C. 
Published: March 2022

AbstractCell size asymmetries are often linked to cell fate decisions, due to cell volumes and cell fate determinants being unequally partitioned during asymmetric cell divisions. A clear example is found in the sea urchin embryo, where a characteristic and obvious unequal 4th cleavage generates micromeres, which are necessary for mesendoderm cell fate specification. Unlike sea urchin development, sea star development is generally thought to have only equal cleavage. However, subtle cell size asymmetries can be observed in sea star embryos; whether those cell size asymmetries are consistently produced during sea star development and if they are involved in cell fate decisions remains unknown. Using confocal live imaging of early embryos we quantified cell size asymmetries in 16-cell stage embryos of two sea star species, Patiria miniata and Patiriella regularis. Using photoconversion to perform lineage tracing, we find that the position of the smallest cells of P. miniata embryos is biased toward anterior ventral tissues. However, both blastomere dissociation and mechanical removal of one small cell do not prevent dorsoventral (DV) axis formation, suggesting that embryos compensate for the loss of those cells and asymmetric partitioning of maternal determinants is not strictly necessary for DV patterning. Finally, we show that manipulating cell size to introduce artificial cell size asymmetries is not sufficient to direct the positioning of the future DV axis in P. miniata embryos. Our results show that although cell size asymmetries are consistently produced during sea star early cleavage and may be predictive of the DV axis, they are not necessary to instruct DV axis formation.