bluuebunny/crossref_metadata_2025 huggingface dataset:
Feed restriction in mid-lactation dairy cows. II: Effects on protein metabolism-related blood metabolites
Authors: Ansia I. , Ohta Y. , Fujieda T. , Drackley J. K.
Published: June 2020

The aim of the study was to describe the metabolic responses of protein metabolism to a period of negative nutrient balance induced by feed restriction (FR). Seven multiparous Holstein cows (93 ± 15 days in milk) were randomly assigned to 7 treatments in a 7 × 4 Youden square design. Daily intake was restricted to provide 60% of energy requirements during 5 d except for one treatment with ad libitum (AL) feeding. While 5 out of 7 experimental treatments involved abomasal supplementation of AA or glucose, in this article we evaluated only the effects of FR by comparing both control treatments (AL and FR). Data of 2 cows within the AL group were removed due to sickness and therefore it had n = 2. A rapid decrease of most amino acids in plasma was paired with an increase in blood urea N with its peak on d 2 and decreasing afterwards. On the other hand, Lys, Arg, Gly, Gln, and Cys were greater during FR. Comparing the fluctuation of all the essayed N components in circulation across the 5-d period, protein tissue mobilization may have supplied amino acids for catabolism to provide needs for N and energy precursors.

Implications

The short-term feed restriction model described in this article can serve as an alternative to study metabolic adaptations during the transition period. The response observed of the protein metabolism sets the baseline to measure the effect of nutrients supplementation and identify those candidates that will improve milk production and overall health after calving.
A peptide-signal amplification strategy for the detection and validation of neoepitope presentation on cancer biopsies
Authors: Ramarathinam Sri H. , Faridi Pouya , Peng Angela , Szeto Pacman , Wong Nicholas C. , Behren Andreas , Shackleton Mark , Purcell Anthony W.
Published: June 2020

Targeting the right cancer-specific peptides presented by Human Leukocyte antigen (HLA) class I and II molecules on the tumor cell surface is a crucial step in cancer immunotherapy. Numerous approaches have been proposed to predict the presentation of potential neoepitopes that may be targeted through immune-based therapies. Often founded on patient specific somatic mutations, the routine validation of their actual appearance on the tumor cell surface is a significant barrier to realising personalized cancer immunotherapy. This can be attributed to the lack of robust and adaptable assays for antigen presentation that offer the required sensitivity to deal with the limited amounts of patient tumor tissue available. Rather than personalize individual assays we propose the use mass spectrometry to identify tumor neoepitopes from HLA-bound peptides directly isolated form the surface of tumor biopsies. We have developed a microscale HLA-peptide complex immunoprecipitation protocol combined with tandem mass tagging (TMT) to directly sequence HLA-bound peptides using mass spectrometry. Using this strategy, we identified HLA-bound peptides from as few as ~1000 cultured cells and from a small piece (~1 mg) of whole melanoma tumour tissue, encompassing epitopes derived from Melanoma-associated antigens and potential neoantigens.
Mapping Connectional Differences between Humans and Macaques in the Nucleus Accumbens Shell-Core Architecture
Authors: Xia Xiaoluan , Fan Lingzhong , Cheng Chen , Cheng Luqi , Cao Long , He Bin , Chen Junjie , Li Haifang , Jiang Tianzi
Published: June 2020

Two nucleus accumbens subregions, the shell and core, differ in the patterns whereby they integrate signals from prefrontal and limbic areas of the brain. In this study, we investigated whether the disproportionate volumetric differences of these brain areas, particularly the prefrontal cortex, between humans and macaques are accompanied by unique modifications of their macroscopic integrative connections with the shell and core. More specifically, we characterized the tractographic connectivity profiles of the human and macaque shell-core architecture and compared them between the two species. To make the cross-species comparisons more viable, we used the same whole-brain voxel-wise tractography-defined shell-like and core-like divisions in the two species as seeds and delineated pairs of interspecies connectionally comparable (ICC) target regions based on the similarity of the resting-state functional connectivity profiles for the two species, and finally used these seeds and ICC targets to establish a fingerprint-based common space for cross-species comparisons. Our results revealed that dissimilar structural connectivity profiles were found in the prefrontal but not the subcortical target group. We further localized this difference to specific targets to infer possible functional modifications between the two species.
Dynamic integration of enteric neural stem cells in ex vivo organotypic colon cultures
Authors: Navoly Georgina , McCann Conor J.
Published: June 2020

Enteric neural stem cells (ENSC) have been identified as a possible treatment for enteric neuropathies. Afterin vivotransplantation, ENSC and their derivatives have been shown to engraft within colonic tissue, migrate and populate endogenous ganglia, and functionally integrate with the enteric nervous system. However, the mechanisms underlying the integration of donor ENSC, in recipient tissues, remains unclear. Here, using a modifiedex vivoorganotypic culture system we show that donor ENSC-derived cells integrate across the colonic wall in a dynamic fashion, across a three-week period. We further show that donor cells display two integrative patterns; longitudinal migration and medial invasion which allow donor cells to populate colonic tissue. Moreover, we demonstrate that significant remodelling of the intestinal ECM, and musculature, occurs upon transplantation to facilitate donor cell integration. Thus, our results provide critical evidence on the timescale, and mechanisms, which regulate donor ENSC integration within recipient gut tissue.
Global FAW population genomic signature supports complex introduction events across the Old World
Authors: Tay WT , Rane RV , Padovan A , Walsh TK , Elfekih S , Downes S , Nam K , d’Alençon E , Zhang J , Wu Y , Nègre N , Kunz D , Kriticos DJ , Czepak C , Otim MH , Gordon KHJ
Published: June 2020

Native to the Americas, the invasiveSpodoptera frugiperda(fall armyworm; FAW) was reported in West Africa in 2016, followed by chronological order of detections across the Old World and the hypothesis of an eastward Asia expansion. We explored population genomic signatures of American and Old World FAW and identified 12 maternal mitochondrial DNA genome lineages across the invasive range, while from 870 high-quality nuclear single nucleotide polymorphic DNA markers five distinct New World population clusters were identified, broadly reflected their native geographical ranges and absence of host-plant preferences. We identified unique admixed Old World populations, and admixed and non-admixed Asian FAW individuals, all of which suggested multiple introductions underpinned the pest’s global spread. Directional gene flow from the East into eastern Africa was also detected, in contrast to the west-to-east spread hypothesis. Our study demonstrated population genomic approaches via international partnership to address global emerging pest threats and biosecurity challenges.
An Adaptive Detection for Automatic Spike Sorting Based on Mixture of Skew-t distributions
Authors: Toosi Ramin , Akhaee Mohammad Ali , Dehaqani Mohammad-Reza A.
Published: June 2020

Developing new techniques of simultaneous recoding using thousand electrodes, make the wide variety of spike waveforms across multiple channels. This problem causes spike loss and raise the crucial issue of spike sorting with unstable clusters. While there exist many automatic spike sorting methods, there has been a lack of studies developing robust and adaptive spike detection algorithm. Here, an adaptive procedure is introduced to improve the detection of spikes in different scenarios. This procedure includes a new algorithm which aligns the spike waveforms at the point of extremums. The other part is statistical filtering, which seeks to remove noises that mistakenly detected as true spike. To deal with non-symmetrical clusters, we proposed a new clustering algorithm based on the mixture of skew-t distributions. The proposed method could overcome the spike loss and skewed cells challenges by offering an improvement over automatic detection, alignment, and clustering of spikes. Investigating the sorted spikes, reveals that proposed adaptive algorithm improves the performance of the spike detection in both terms of precision and recall. The adaptive algorithm has been validated on different datasets and demonstrates a general solution to precise spike sorting, in vitro and in vivo.
Gonads or body? Differences in gonadal and somatic photoperiodic growth response in two vole species
Authors: van Rosmalen Laura , van Dalum Jayme , Hazlerigg David G. , Hut Roelof A.
Published: June 2020

To optimally time reproduction, seasonal mammals use a photoperiodic neuroendocrine system (PNES) that measures photoperiod and subsequently drives reproduction. To adapt to late spring arrival at northern latitudes, a lower photoperiodic sensitivity and therefore a higher critical photoperiod for reproductive onset is necessary in northern species to arrest reproductive development until spring onset. Temperature-photoperiod relationships, and hence food availability-photoperiod relationships, are highly latitude dependent. Therefore, we predict PNES sensitivity characteristics to be latitude-dependent. Here, we investigated photoperiodic responses at different times during development in northern- (tundra/root vole,Microtus oeconomus) and southern vole species (common vole,Microtus arvalis) exposed to constant short (SP) or long photoperiod (LP).

M. oeconomusgrows faster under LP, whereas no photoperiodic effect on somatic growth is observed inM. arvalis. Contrastingly, gonadal growth is more sensitive to photoperiod inM. arvalis, suggesting that photoperiodic responses in somatic and gonadal growth can be plastic, and might be regulated through different mechanisms. In both species, thyroid-stimulating-hormone-β subunit (Tshβ) and iodothyronine-deiodinase 2 (Dio2) expression is highly increased under LP, whereasTshrandDio3decreases under LP. HighTshrlevels in voles raised under SP may lead to increased sensitivity to increasing photoperiods later in life. The higher photoperiodic inducedTshrresponse inM. oeconomussuggests that the northern vole species might be more sensitive to TSH when raised under SP.

Species differences in developmental programming of the PNES, which is dependent on photoperiod early in development, may form part divergent breeding strategies evolving as part of latitudinal adaptation.

Summary statement

Development of the neuroendocrine system driving photoperiodic responses in gonadal and somatic growth differ between the common and the tundra vole, indicating that they use a different breeding strategy.
Overhauling a faulty control in the CDC-recommended SARS-CoV-2 RT-PCR test panel
Authors: Dekker Rob J. , Ensink Wim A. , van Leeuwen Selina , Rauwerda Han , Breit Timo M.
Published: June 2020

To battle the COVID-19 pandemic, widespread testing for the presence of the SARS-CoV-2 virus is worldwide being employed by specific real-time RT-PCR (rRT-PCR) of viral RNA. The CDC has issued a recommended panel of PCR-based test sets that entail several primer/probe sets that target the SARS-CoV-2 N-gene, but also one that targets the human RNase P gene (h-RP) as a positive control for RNA extraction and/or reverse-transcription (RT) efficacy.

We discovered that the CDC-recommended h-RP primer/probe set has a faulty design, because both PCR primers are located in the same exon, which allows for unwanted PCR-amplification of background genomic DNA (gDNA). By removing RNA from nose-swab samples by an RNase treatment, we showed that the presence of gDNA in samples resulted in false-positive signals for the h-RP test control. This is rather serious, because it could lead to false-negative test outcomes, since the CDC interpretation of an absent SARS-CoV-2 rRT-PCR signal plus a positive h-RP rRT-PCR signal is interpreted as “2019-nCoV not detected”, whereas a false-positive h-RP rRT-PCR signal resulting from amplification of gDNA should be interpreted as “Invalid Result” and the procedure should be repeated.

In order to overhaul the faulty h-RP rRT-PCR primer/probe set with minimal modification, we designed and tested several new h-RP reverse primers. Replacement of the CDC-recommended PCR reverse primer with our selected exon-exon junction reverse primer corrected the problem of false-positive results with this important SARS-CoV-2 RT-PCR test control and thus eliminated the problem of potential false-negative COVID-19 diagnoses.
CRISPR/Cas “non-target” sites inhibit on-target cutting rates
Authors: Moreb Eirik A. , Hutmacher Mitchell , Lynch Michael D.
Published: June 2020

CRISPR/Cas systems have become ubiquitous for genome editing in eukaryotic as well as bacterial systems. Cas9 associated with a guide RNA (gRNA) searches DNA for a matching sequence (target site) next to a protospacer adjacent motif (PAM) and once found, cuts the DNA. The number of PAM sites in the genome are effectively a non-target pool of inhibitory substrates, competing with the target site for the Cas9/gRNA complex. We demonstrate that increasing the number of non-target sites for a given gRNA reduces on-target activity in a dose dependent manner. Furthermore, we show that the use of Cas9 mutants with increased PAM specificity towards a smaller subset of PAMs (or smaller pool of competitive substrates) improves cutting rates. Decreasing the non-target pool by increasing PAM specificity provides a path towards improving on-target activity for slower high fidelity Cas9 variants. These results demonstrate the importance of competitive non-target sites on Cas9 activity and, in part, may help to explain sequence and context dependent activities of gRNAs. Engineering improved PAM specificity to reduce the competitive non-target pool offers an alternative strategy to engineer Cas9 variants with increased specificity and maintained on-target activity.

Highlights

The pool of non-target PAM sites inhibit Cas9/gRNA on-target activity

non-target PAM inhibition is dose dependent

non-target PAM inhibition is a function of gRNA sequence

non-target PAM inhibition is a function of Cas9 levels
Computational studies of drug repurposing targeting P-glycoprotein mediated multidrug-resistance phenotypes in agents of neglected tropical diseases
Authors: Jaishankar Nivedita , Muthamilselvan Sangeetha , Palaniappan Ashok
Published: June 2020

Mammalian ABCB1P-glycoprotein is an ATP- dependent efflux pump with broad substrate specificity associated with cellular drug resistance. Homologous to this role in mammalian biology, the P-glycoprotein of agents of neglected tropical diseases (NTDs) mediates the emergence of multidrug-resistance phenotypes. The clinical and socioeconomic implications of NTDs are exacerbated by the lack of research interest among Big Pharma for treating such conditions. This work aims to characterise P-gp homologues in certain agents of key NTDs, namely

Protozoa: Leishmania major, Trypanosoma cruzi;

Helminths: Onchocerca volvulus, Schistosoma mansoni.

PSI-BLAST searches against the genome of each of these organisms confirmed the presence of P-gp homologues. Each homologue was aligned against five P-gp sequences of known structure, to identify the most suitable template based on sequence homology, phylogenetic nearest neighbor, and query coverage. Antibiotics used in the current line of therapy against each of these pathogens were identified using PubChem and their SMILES structures were converted to PDB using BABEL software. Potential antibiotics to test against the set of FDA-approved antibiotics were identified based on similarity to the chemical class of the known drugs and repurposing of the existing drugs. Docking studies of the respective modelled Pgp structures and the set of antibiotic ligands were carried out using AutoDock and the most tenable target-ligand conformations were assessed. The interacting residues within 4.5 Å of the ligand were identified, and the binding pockets were studied. The relative efficacy of the new drugs and the interacting pump residues were identified. Our studies could lay the foundation for the development of effective synergistic or new therapies against key neglected tropical diseases.
Spatial distribution and cognitive impact of cerebrovascular risk-related white matter hyperintensities
Authors: Veldsman Michele , Kindalova Petya , Husain Masud , Kosmidis Ioannis , Nichols Thomas E.
Published: June 2020

Objectives

White matter hyperintensities (WMHs) are considered macroscale markers of cerebrovascular burden and are associated with increased risk of vascular cognitive impairment and dementia. However, the spatial location of WMHs has typically been considered in broad categories of periventricular versus deep white matter. The spatial distribution of WHMs associated with individual cerebrovascular risk factors (CVR), controlling for frequently comorbid risk factors, has not been systematically investigated at the population level in a healthy ageing cohort. Furthermore, there is an inconsistent relationship between total white matter hyperintensity load and cognition, which may be due to the confounding of several simultaneous risk factors in models based on smaller cohorts.

Methods

We examined trends in individual CVR factors on total WMH burden in 13,680 individuals (aged 45-80) using data from the UK Biobank. We estimated the spatial distribution of white matter hyperintensities associated with each risk factor and their contribution to explaining total WMH load using voxel-wise probit regression and univariate linear regression. Finally, we explored the impact of CVR-related WMHs on speed of processing using regression and mediation analysis.

Results

Contrary to the assumed dominance of hypertension as the biggest predictor of WMH burden, we show associations with a number of risk factors including diabetes, heavy smoking, APOEε4/ε4 status and high waist-to-hip ratio of similar, or greater magnitude to hypertension. The spatial distribution of WMHs varied considerably with individual cerebrovascular risk factors. There were independent effects of visceral adiposity, as measured by waist-to-hip ratio, and carriage of the APOEε4 allele in terms of the unique spatial distribution of CVR-related WMHs. Importantly, the relationship between total WMH load and speed of processing was mediated by waist-to-hip ratio suggesting cognitive consequences to WMHs associated with excessive visceral fat deposition.

Conclusion

Waist-to-hip ratio, diabetes, heavy smoking, hypercholesterolemia and homozygous APOEε4 status are important risk factors, beyond hypertension, associated with WMH total burden and warrant careful control across ageing. The spatial distribution associated with different risk factors may provide important clues as to the pathogenesis and cognitive consequences of WMHs. High waist-to-hip ratio is a key risk factor associated with slowing in speed of processing. With global obesity levels rising, focused management of visceral adiposity may present a useful strategy for the mitigation of cognitive decline in ageing.
SalivaryAsHPX12influence pre-blood meal associated behavioral properties in the mosquitoAnopheles stephensi
Authors: Kumari Seena , De Tanwee Das , Chauhan Charu , Rani Jyoti , Tevatiya Sanjay , Sharma Punita , Pandey Kailash C , Pande Veena , Dixit Rajnikant
Published: June 2020

In the adult female mosquito, successful blood meal acquisition is accomplished by salivary glands, which releases a cocktail of proteins to counteract vertebrate host’s immune-homeostasis. However, the biological relevance of many salivary proteins remains unknown. Here, we characterize a salivary specific Heme peroxidase family member HPX12, originally identified fromPlasmodium vivaxinfected salivary RNAseq data of the mosquitoAnopheles stephensi. We demonstrate that dsRNA silencing mediated mRNA depletion of salivaryAsHPX12(80-90%), causes enhanced host attraction but reduced blood-meal acquisition abilities, by increasing probing propensity (31%), as well as probing time (100–200s,P<0.0001) as compared to control (35-90s) mosquitoes group. Altered expression of the salivary secretory and antennal proteins may account for an unusual fast release of salivary cocktail proteins, but the slowing acquisition of blood meal, possibly due to salivary homeostasis disruption ofAsHPX12silenced mosquitoes. A parallel transcriptional modulation in response to blood feeding andP. vivaxinfection, further establish a possible functional correlation ofAsHPX12role in salivary immune-physiology andPlasmodiumsporozoites survival/transmission. We propose that salivary HPX12 may have a vital role in the management of ‘pre- and post’-blood meal associated physiological-homeostasis and parasite transmission.

Graphical abstract

Figure 1:

Schematic representation of mosquito’s blood meal acquisition and upshot on blood-feeding after silencing of salivary gland HPX-12.(A)After landing over host skin, mosquito mouthparts (proboscis) actively engaged to search, probe, and pierce the skin followed by a rapid release of the pre-synthesized salivary cocktail, which counteracts the host homeostasis, inflammation, and immune responses, during blood meal uptake.(B)Silencing of HPX-12 disrupts salivary gland homeostasis, enhancing mosquito attraction, possibly by up-regulating odorant-binding proteins genes-OBP-7,10 and OBP-20 expression in the Olfactory System. However, HPX-12 disruption may also cause significant effects on pre-blood meal associated probing abilities, which may be due to fast down-regulation of salivary cocktail proteins such as Anopheline, Apyrase, D7L proteins.
Persistence of quantal synaptic vesicle recycling following dynamin depletion
Authors: Afuwape Olusoji A.T. , Chanaday Natali L. , Kasap Merve , Monteggia Lisa M. , Kavalali Ege T.
Published: June 2020

Dynamins are GTPases required for pinching vesicles off the plasma membrane once a critical curvature is reached during endocytosis. Here, we probed dynamin function in central synapses by depleting all three dynamin isoforms in postnatal hippocampal neurons. We found a decrease in the propensity of evoked neurotransmission as well as a reduction in synaptic vesicle numbers. Using the fluorescent reporter vGluT1-pHluorin, we observed that compensatory endocytosis after 20 Hz stimulation was arrested in ~40% of presynaptic boutons, while remaining synapses showed only a modest effect suggesting the existence of a dynamin-independent endocytic pathway in central synapses. Surprisingly, we found that the retrieval of single synaptic vesicles, after either evoked or spontaneous fusion, was largely impervious to disruption of dynamins. Overall, our results suggest that classical dynamin-dependent endocytosis is not essential for retrieval of synaptic vesicle proteins after quantal single synaptic vesicle fusion.
Flanking sequence preference modulatesde novoDNA methylation in the mouse genome
Authors: Mallona Izaskun , Ilie Ioana Mariuca , Manzo Massimiliano , Caflisch Amedeo , Baubec Tuncay
Published: June 2020

Mammaliande novoDNA methyltransferases (DNMT) are responsible for the establishment of cell-type-specific DNA methylation in healthy and diseased tissues. Through genome-wide analysis ofde novomethylation activity in murine stem cells we uncover that DNMT3A prefers to methylate CpGs followed by cytosines or thymines, while DNMT3B predominantly methylates CpGs followed by guanines or adenines. These signatures are further observed at non-CpG sites, resembling methylation context observed in specialised cell types, including neurons and oocytes. We further show that these preferences are not mediated by the differential recruitment of the twode novoDNMTs to the genome but are resulting from structural differences in their catalytic domains. Molecular dynamics simulations suggest that, in case of DNMT3A, the preference is due to favourable polar interactions between the flexible Arg836 side chain and the guanine that base-pairs with the cytosine following the CpG. This context-dependentde novoDNA methylation provides additional insights into the complex regulation of methylation patterns in different cell types.
Bypassing juvenility, first report of functional flowering and fruiting in six months old seedlings ofCordia myxa L.(lasuda)
Authors: Guleria Vipan
Published: June 2020

Cordia myxaL. is a medium-sized broad-leaved deciduous tree of flowering plant belongs to Boraginaceae. It grows naturally from dry desert India up to hills of Himalayas in India up to 1400 m elevation above mean sea level. Fruits are mostly used for pickle making and dried for its use in local off season vegetable recipes since long time. The ripe fruits are full of vitamins and its regular use is supposed to be helpful in good growth of hair. Lasuda preparations are, thus, good for people whose constitution might have tendency to go bald. In addition to fruit, Lasuda bark and roots are also very effective as a local remedy against cough, cold and various other ailments connected with indigestion and throat problems. At regional research laboratory of Dr. Y. S. Parmar University of Horticulture and Forestry, Nauni (India) we are working for the last 12 years on various aspects like propagation and development of promising strains ofCordia myxa. Grafting/budding techniques have been standardized to produce true to type precocious plants which bear flower and fruits in two to three years. However, flowering and fruiting has been observed in six months old seedling of seed origin, which can be ascribed to biochemical or cellular changes. Early flowering and fruiting is a rare phenomenon in tree seedlings of the species which otherwise flower at the age of 7-8 years. This could be very useful for manipulating the species at gene as well as physiological level in future to get early fruits and breeding of the species.
MSCs from syndecan-3 null mice exhibit enhanced adhesion to collagen type I, hyperactivation of the AKT pathway and increased efficacy in inflammatory arthritis
Authors: Jones Fiona K , Stefan Andrei , Kay Alasdair G , Hyland Mairead , Morgan Rebecca , Forsyth Nicholas R , Pisconti Addolorata , Kehoe Oksana
Published: June 2020

1

Rheumatoid arthritis (RA) is a debilitating and painful inflammatory autoimmune disease characterised by the accumulation of leukocytes in the synovium, cartilage destruction and bone erosion. The immunomodulatory effects of bone marrow derived mesenchymal stem cells (MSCs) has been widely studied and the recent observations that syndecan-3 (SDC3) is selectively pro-inflammatory in the joint led us to hypothesise that SDC3 might play an important role in MSC biology. MSCs isolated from bone marrow of wild type and Sdc3−/−mice were used to assess immunophenotype, differentiation, adhesion and migration properties and cell signalling pathways. While both cell types show similar differentiation potential and forward scatter values, the cell complexity in wild type MSCs was significantly higher than in Sdc3−/−cells and was accompanied by lower spread surface area. Moreover, Sdc3−/−MSCs adhered more rapidly to collagen type I and showed a dramatic increase in AKT phosphorylation, accompanied by a decrease in ERK1/2 phosphorylation compared with control cells. In a mouse model of antigen-induced inflammatory arthritis, intraarticular injection of Sdc3−/−MSCs yielded enhanced recovery compared to injection of wild type MSCs. In conclusion, our data suggest that syndecan-3 regulates MSC adhesion and efficacy in inflammatory arthritis, likely via induction of the AKT pathway.
BUB-1 targets PP2A:B56 to regulate chromosome congression during meiosis I inC. elegansoocytes
Authors: Borja Laura Bel , Soubigou Flavie , Taylor Samuel J.P. , Bringas Conchita Fraguas , Budrewicz Jacqueline , Lara-Gonzalez Pablo , Turpin Christopher G. Sorensen , Bembenek Joshua N. , Cheerambathur Dhanya K. , Pelisch Federico
Published: June 2020

Protein Phosphatase 2A (PP2A) is an heterotrimer composed of scaffolding (A), catalytic (C), and regulatory (B) subunits with various key roles during cell division. While A and C subunits form the core enzyme, the diversity generated by interchangeable B subunits dictates substrate specificity. Within the B subunits, B56-type subunits play important roles during meiosis in yeast and mice by protecting centromeric cohesion and stabilising the kinetochore-microtubule attachments. These functions are achieved through targeting of B56 subunits to centromere and kinetochore by Shugoshin and BUBR1. In the nematodeCaenorhabditis elegans(C. elegans)the closest BUBR1 ortholog lacks the B56 interaction domain and the Shugoshin orthologue is not required for normal segregation during oocyte meiosis. Therefore, the role of PP2A inC. elegansfemale meiosis is not known. Here, we report that PP2A is essential for meiotic spindle assembly and chromosome dynamics duringC. elegansfemale meiosis. Specifically, B56 subunits PPTR-1 and PPTR-2 associate with chromosomes during prometaphase I and regulate chromosome congression. The chromosome localization of B56 subunits does not require shugoshin orthologue SGO-1. Instead we have identified the kinase BUB-1 as the key B56 targeting factor to the chromosomes during meiosis. PP2A BUB-1 recruits PP2A:B56 to the chromosomes via dual mechanism: 1) PPTR-1/2 interacts with the newly identified LxxIxE short linear motif (SLiM) within a disordered region in BUB-1 in a phosphorylation-dependent manner; and 2) PPTR-2 can also be recruited to chromosomes in a BUB-1 kinase domain-dependent manner. Our results highlight a novel, BUB-1-dependent mechanism for B56 recruitment, essential for recruiting a pool of PP2A required for proper chromosome congression during meiosis I.
ALX1-related Frontonasal Dysplasia Results From Defective Neural Crest Cell Development and Migration
Authors: Pini Jonathan , Kueper Janina , Hu Yiyuan David , Kawasaki Kenta , Yeung Pan , Tsimbal Casey , Yoon Baul , Carmichael Nikkola , Maas Richard L. , Cotney Justin , Grinblat Yevgenya , Liao Eric C.
Published: June 2020

A pedigree of subjects with frontonasal dysplasia (FND) presented with bilateral oblique facial clefts and ocular phenotypes. Genome sequencing and analysis identified a L165F missense variant in the homeodomain of the transcription factorALX1which was imputed to be pathogenic. Induced pluripotent stem cells (iPSC) were derived from the subjects and differentiated to neural crest cells (NCC). NCC derived from ALX1L165F/L165FiPSC were more sensitive to apoptosis, showed an elevated expression of several neural crest progenitor state markers, and exhibited impaired migration compared to wild type controls. NCC migration was also evaluatedin vivousing lineage tracing in a zebrafish model, which revealed defective migration of the anterior NCC stream that contributes to the median portion of the anterior neurocranium, phenocopying the clinical presentation. Analysis of human NCC culture media revealed a change in the level of bone morphogenic proteins (BMP), with a low-level of BMP2 and a high level of BMP9. Soluble BMP2 and BMP9 antagonist treatments were able to rescue the defective migration phenotype. Taken together, these results demonstrate a mechanistic requirement ofALX1in NCC development and migration.
Competition NMR for Detection of Hit/Lead Inhibitors of Protein-Protein Interactions
Authors: Musielak Bogdan , Janczyk Weronika , Rodriguez Ismael , Plewka Jacek , Sala Dominik , Magiera-Mularz Katarzyna , Holak Tad A.
Published: June 2020

Screening for small-molecule fragments that can lead to potent inhibitors of protein-protein interactions (PPIs) is often a laborious step as the fragments cannot dissociate the targeted PPI due to their low μM-mM affinities. Here, we describe an NMR competition assay - called w-AIDA-NMR (weak-Antagonist Induced Dissociation Assay-NMR) - that is sensitive to weak μM-mM ligand-protein interactions and which can be used in initial fragment screening campaigns. By introducing point mutations in the complex’s protein that is not targeted by the inhibitor, we lower the effective affinity of the complex allowing for short fragments to dissociate the complex. We illustrate the method with the compounds that block the Mdm2/X-p53 and PD-1/PD-L1 oncogenic interactions. Targeting the PD-/PD-L1 PPI has profoundly advanced the treatment of different types of cancers.
Anatomical Plasticity of the Distal Forelimb Projection of the Ventral Premotor Cortex Four weeks After Primary Motor Cortex Injury
Authors: McNeal David W. , Barbay Scott , Frost Shawn B. , Taylor Michael , Guggenmos David J. , Nudo Randolph J.
Published: June 2020

Brain injury affecting the isocortical frontal cortex is a common pathological occurrence. Many patients report severe deficits to functions of daily living. However, there is a variable degree of motor recovery that occurs with some individuals recovering astounding degrees of motor recovery while others have not. This variability has led researchers into investigating the possible mechanisms for this variability. Recently, several non-human primate studies have shed light on the possibility of spared, ipsilesional motor area taken over the lost function to the damaged cortex. Unfortunately, these studies have focused on long-term adaption ranging from 5months to one year post injury. In this present study, we are the first use rigorous stereological quantification to show that significant neuroplastic changes in the form of changes to neuroanatomical connections between distant cortical area occurs at a very early time point of 4 weeks post injury. Much like the Dancause study in 2005, we found that ishemic damage to the distal forelimb area (DFL) of the primary motor cortex (M1) induced plastic changes between the DFL of the ventral premotor cortex (PMv) and area 1/2 of the somatosensory cortex. Indeed, we found a nearly 2 fold increase in the number of boutons between PMV and area 1/2. Additionally, labeled fibers from PMv change direction from their normal termination within M1 and traveled in a ventral posterior direction toward the somatosensory cortex. Also of interest, several labeled fibers actually traveled through the glial scar of M1 toward the somatosensory cortex. These data demonstrate that a massive neuroplastic response has occurred following an ischemic insult to the DFL of M1. These data may suggest that the brain may be undergoing an attempt to re-establish a degree of motor and or sensory control to compensate for the lost function due to the injury.
Effect of Elbow Flexion Angle on Cortical Voluntary Activation of the Non-Impaired Biceps: A 3 Days Repeated Sessions Study
Authors: Roumengous Thibault , Howell Paul A. , Peterson Carrie L.
Published: June 2020

Measurement of cortical voluntary activation (VA) with transcranial magnetic stimulation (TMS) is limited by technical challenges. One challenge is the difficulty in preferential stimulation of cortical neurons projecting to the target muscle and minimal stimulation of cortical neurons projecting to antagonists. Thus, the motor evoked potential (MEP) response to TMS in the target muscle compared to its primary antagonist may be an important parameter in the assessment of cortical VA. Modulating isometric elbow angle alters the magnitude of MEPs at rest. The purpose of this study was to evaluate the effect of isometric elbow flexion-extension angle on: 1) the ratio of biceps MEP relative to the triceps MEP amplitude across a range of voluntary efforts, and 2) cortical VA. Ten non-impaired participants completed three sessions wherein VA was determined using TMS at 45°, 90° and 120° of isometric elbow flexion, and peripheral electrical stimulation at 90° of elbow flexion. The biceps/triceps MEP ratio was greater in the more flexed elbow angle (120° flexion) compared to 90° during contractions of 50% and 75% of maximum voluntary contraction. Cortical VA assessed in the more extended elbow angle (45° flexion) was lower relative to 90° elbow flexion; this effect was dependent on the biceps/triceps MEP ratio. Cortical VA was sensitive to small changes in the linearity of the voluntary torque and superimposed twitch relationship, regardless of the elbow angle. Peripheral and cortical VA measures at 90° of elbow flexion were repeatable across three days. In conclusion, although the biceps/triceps MEP ratio was increased at a more flexed elbow angle relative to 90°, there was not a corresponding difference in cortical VA. Thus, increasing the MEP ratio via elbow angle did not affect estimation of cortical VA.
Regeneration of a Full-Thickness Defect in Rotator Cuff Tendon with Umbilical Cord-Derived Mesenchymal Stem Cells in a Rat Model
Authors: Yea Ji-Hye , Kim InJa , Sym Gayoung , Park Jin-Kyung , Lee Ah-Young , Cho Byeong Chan , Bae Tae Soo , Kim Byoung Jae , Jo Chris Hyunchul
Published: June 2020

Although rotator cuff disease is a common cause of shoulder pain, there is still no treatment method that could halt or reveres its development and progression. The purpose of this study was to investigate the efficacy of umbilical cord-derived mesenchymal stem cells (UC MSCs) on the regeneration of a full-thickness rotator cuff defect (FTD) in a rat model. We injected either UC MSCs or saline to the FTD and investigated macroscopic, histological and biomechanical results and cell trafficking. Treatment with UC MSCs improved macroscopic appearance in terms of tendon thickness at two weeks, and inflammation, defect size, swelling/redness and connection surrounding tissue and slidability at four weeks compared to the saline group. Histologically, UC MSCs induced the tendon matrix formation recovering collagen organization, nuclear aspect ratio and orientation angle of fibroblast as well as suppressing cartilage-related glycosaminoglycan compared to saline group at four weeks. The UC MSCs group also improved ultimate failure load by 25.0% and 19.0% and ultimate stress by 27.3% and 26.8% at two and four weeks compared to saline group. UC MSCs labeled with PKH26 exhibited 5.3% survival at four weeks compared to three hours after injection. This study demonstrated that UC MSCs regenerated the FTD with tendon tissue similar properties to the normal tendon in terms of macroscopic, histological and biomechanical characteristics in a rat model.
Interactions of SARS-CoV-2 infection with chronic obesity inflammation: a complex network phenomenon
Authors: Favero Giovani Marino , Gomes Mascarenhas Luis Paulo , Furmann Meirielly , Berton Juliana , Miranda Pedro Jeferson
Published: June 2020

Obesity is one of the biggest public health problems in the world, and its pathophysiological characteristics include chronic inflammation with an increase in various circulating inflammatory markers, such as acute inflammatory cytokines. Complications in the respiratory tract are related to bodily problems, which lead to a restriction of lung function due to reduced volume, inducing an increase in respiratory work. SARS-CoV-2 has a high potential for contamination by respiratory secretions and, therefore, obesity is one of the main risk factors for complications due to the association established between obesity, chronic inflammation and respiratory infection. The objective was to analyze the complex relationships between obesity and COVID-19 in a meta-analysis study using complex network modeling and the theoretical knockouts technique. Here, we identify and justify through a mathematical analysis the relationships between all the immunological agents added to the proposed immunological networks, considered as a simple evident interaction, relationship, influence, response, activation, based on our quantifiers. They performed the knockouts of all 52 vertices in the COVID-19 network and obesity - regardless of the environment, which would result in nonsense - and the COVID-19 infection network without considering obesity. The stationary flow vector (flow profile), for some knockouts of immunological interest in COVID-19 infections, was chosen IFNα, IL-6, IL-10, IL-17 and TNFα. This initial study pointed out the importance of chronic inflammation in the obese individual as an important factor in potentiating the disease caused by covid-19 and, in particular, the importance on IL-17.
Glucose Transporter Expression and Regulation Following a Fast in the Ruby-throated Hummingbird,Archilochus colubris
Authors: Ali Raafay S. , Dick Morag F. , Muhammad Saad , Sarver Dylan , Wong G. William , Welch Kenneth C.
Published: June 2020

Hummingbirds subsist almost exclusively on nectar sugar and face extreme challenges blood sugar regulation. Transmembrane sugar transport is mediated by facilitative glucose transporters (GLUTs) and the capacity for sugar transport is dependent on both the activity of GLUTs and their localisation to the plasma membrane (PM). In this study, we determined the relative protein abundance in whole-tissue (WT) homogenates and PM fractions via immunoblot using custom antibodies for GLUT1, GLUT2, GLUT3, and GLUT5 in flight muscle, heart, and, liver of ruby-throated hummingbirds (Archilochus colubris). GLUTs examined were detected in nearly all tissues tested. Hepatic GLUT1 was minimally present in WT homogenates and absent in PM fractions. GLUT5 was expressed in hummingbird flight muscles at levels comparable to that of their liver, consistent with the hypothesised uniquely high fructose-uptake and oxidation capacity of this tissue. To assess GLUT regulation, we fed ruby-throated hummingbirds 1M sucrosead libitumfor 24 hours followed by either 1 hour of fasting or continuedad libitumfeeding until sampling. We measured relative GLUT abundance and concentrations of circulating sugars. Blood fructose concentration in fasted hummingbirds declined from ∼5mM to ∼0.18mM, while fructose-transporting PM GLUT2 and PM GLUT5 did not change in abundance. Blood glucose concentrations remained elevated in both fed and fasted hummingbirds, at ∼30mM, while glucose-transporting PM GLUT1 and PM GLUT3 in the flight muscle and liver, respectively, declined in fasted birds. Our results suggest that glucose uptake capacity is dynamically reduced in response to fasting, allowing for maintenance of elevated blood glucose levels, while fructose uptake capacity remains constitutively elevated promoting depletion of blood total fructose within the first hour of a fast.

Summary statement

Hummingbird ingest nectar rich in glucose and fructose. When fasted, tissue capacity for circulating glucose import declines while remaining elevated for fructose. This may underlie maintenance of high blood glucose and rapid depletion of blood fructose.
Nuclear deformation causes DNA damage by increasing replication stress
Authors: Shah Pragya , Hobson Chad M. , Cheng Svea , Colville Marshall , Paszek Matthew , Superfine Richard , Lammerding Jan
Published: June 2020

Cancer metastasis, i.e., the spreading of tumor cells from the primary tumor to distant organs, is responsible for the vast majority of cancer deaths. In the process, cancer cells migrate through narrow interstitial spaces substantially smaller in cross-section than the cell. During such confined migration, cancer cells experience extensive nuclear deformation, nuclear envelope rupture, and DNA damage. The molecular mechanisms responsible for the confined migration-induced DNA damage remain incompletely understood. While in some cell lines, DNA damage is closely associated with nuclear envelope rupture, we show that in others, mechanical deformation of the nucleus is sufficient to cause DNA damage, even in the absence of nuclear envelope rupture. This deformation-induced DNA damage, unlike nuclear envelope rupture-induced DNA damage, occurs primarily in S/G2 phase of the cell cycle and is associated with replication forks. Nuclear deformation, resulting from either confined migration or external cell compression, increases replication stress, possibly by increasing replication fork stalling, providing a molecular mechanism for the deformation-induced DNA damage. Thus, we have uncovered a new mechanism for mechanically induced DNA damage, linking mechanical deformation of the nucleus to DNA replication stress. This mechanically induced DNA damage could not only increase genomic instability in metastasizing cancer cells, but could also cause DNA damage in non-migrating cells and tissues that experience mechanical compression during development, thereby contributing to tumorigenesis and DNA damage response activation.
Glycocalyx-mediated Cell Adhesion and Migration
Authors: Schmidt Samuel , Weigelin Bettina , Riet Joost te , Boekhorst Veronika te , Lindert Mariska te , Wijers-Rouw Mietske , Lelli Barbara , Rognoni Lorenz , Krause-Vortmeyer Marina , Messent Anthea , Bracci Luisa , Gottschalk Kay-Eberhard , Kissler Stephan , Humphries Martin J. , Lefeber Dirk J. , Fransen Jack , Friedl Peter
Published: June 2020

Cell migration is a force-dependent adaptive process mediated by integrin-dependent adhesion as well as other yet poorly defined interactions to the extracellular matrix. Using enzymatic multi-targeted digestion of sugar moieties on the surface of mesenchymal cells and leukocytes after interference with integrin function, we demonstrate that the surface glycocalyx represents an independent adhesion system. The glycocalyx mediates cell attachment to ECM ligand in the 100-500 pN force range and amoeboid migration in 3D environmentsin vitroandin vivo. Glycan-based adhesions consist of actin-rich membrane deformations and appositions associated with bleb-like and other protrusions forming complex-shaped sub-micron contact sites to ECM fibrils. These data implicate the glycocalyx in mediating generic stickiness to support nanoscale interactions (nanogrips) between the cell surface and ECM, mechano-coupling, and migration.
Inhibiting proBDNF to mature BDNF conversion leads to autism-like phenotypesin vivo
Authors: You He , Mizui Toshiyuki , Kiyosue Kazuyuki , Takao Keizo , Miyakawa Tsuyoshi , Kato Koichi , Otsuka Mitsuru , Bai Ting , Xia Kun , Lu Bai , Kojima Masami
Published: June 2020

Autism spectrum disorders (ASD) comprise a range of early age-onset neurodevelopment disorders with genetic heterogeneity. Most ASD related genes are involved in synaptic function, which is oppositely regulated by brain-derived neurotrophic factor (BDNF): the precursor proBDNF inhibits while mature BDNF (mBDNF) potentiates synapses. Here we generated a knock-in mouse line (BDNFmet/leu) in which the conversion of proBDNF to mBDNF is inhibited. Biochemical experiments revealed residual mBDNF but excessive proBDNF in the brain. Similar to other ASD mouse models, the BDNFmet/leumice showed decreased brain volumes, reduced dendritic arborization, altered spines, and impaired synaptic transmission and plasticity. They also exhibited ASD-like phenotypes, including stereotypical behaviors, deficits in social interaction, hyperactivity, and elevated stress response. Interestingly, the plasma level of proBDNF, but not mBDNF, was significantly elevated in ASD patients. These results suggest that proBDNF level, but notBdnfgene, is associated with autism-spectrum behaviors, and identify a potential blood marker and therapeutic target for ASD.