bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural integrity following focused ultrasound thalamotomy and its correlation with tremor relief
Authors: Zur Gil , Lesman-Segev Orit , Schlesinger Ilana , Goldsher Dorith , Sinai Alon , Zaaroor Menashe , Assaf Yaniv , Eran Ayelet , Kahn Itamar
Published: May 2019

Background

Magnetic-resonance-guided focused ultrasound ablation of ventral intermediate nucleus of the thalamus is a new treatment for tremor disorders.

Objectives

We sought to evaluate the white matter integrity prior to and following focused ultrasound ablation and its correlation with clinical outcome.

Methods

22 patients with essential tremor and 17 patients with Parkinson’s disease underwent tremor and quality-of-life assessments prior to and at one and six months following focused ultrasound ablation. All patients underwent MRI including T1, T2-FLAIR and diffusion weighted imaging before treatment and at one day, 7–10 days, 1–3 months, and 6 months or more following it. Diffusivity parameters were calculated and fiber tractography measures were extracted. Change in diffusivity parameters were assessed inside the ablated core, in the motor thalamus and throughout the dentato-rubro-thalamo-cortical tract.

Results

We found short-term changes in the motor thalamus and in the tract between the thalamus and regions within the dentato-rubro-thalamo-cortical tract. Long term damage was found in the ablated core and in the tract connecting the thalamus and red-nucleus. Inverse correlation was found between fractional anisotropy in the motor thalamus one day following ablation and tremor improvement in both patient groups, with lower values before treatment associated with better outcome (tremor relief) in essential tremor patients.

Conclusions

Short-and long-term changes in white matter integrity are present following focused ultrasound thalamotomy. Regions demonstrating long-term white matter changes may be responsible for the tremor relief seen in patients, implicating these regions in the disorder’s pathogenesis.
Genome-wide association study of plasma triglycerides, phospholipids and relation to cardio-metabolic risk factors
Authors: Demirkan Ayşe , Pool Rene , Deelen Joris , Beekman Marian , Liu Jun , Harms Amy C. , Vaarhorst Anika , Hagenbeek Fiona A , Willemsen Gonneke , Verhoeven Aswin , Amin Najaf , van Dijk Ko Willems , Hankemeier Thomas , Boomsma Dorret I. , Slagboom Eline , van Duijn Cornelia M.
Published: May 2019

There is continuous interest in the genetic determinants of plasma triglycerides (TGs) and phospholipids and their role in the etiology of cardiovascular disease (CVD). Here, we report the results of a Dutch genome wide association study (GWAS) of an in-house developed lipidomics platform, focusing on 90 plasma lipids. Lipids were assessed by liquid chromatography mass spectrometry in participants from the Leiden Longevity Study, the Netherlands Twin Register and the Erasmus Rucphen Family (ERF) study and meta-analysed, resulting in a sample size of 5537 participants. In addition, we performed genetic correlation analyses between the 90 plasma lipids and markers of metabolic health, as well as vascular pathology and CVD combining our GWAS results with publicly available GWAS outputs. We replicated previously known associations between 34 lipids and 10 lipid quantitative trait loci (lipQTL) (GCKR, APOA1, FADS1, SGPP1,TMEM229B, LIPC, PDXDC1, CETP, CERS4andSPTLC3) with metabolome-wide (P < 1.61 × 10−9) significance. Moreover, we report 6 novel phospholipid-related and 5 triglyceride (TG)-related loci:SGGP1(SM21:0),SPTLC3(SM21:0 and SM25:1),FADS1(LPCO16:1, PC38:2, PEO36:5, PEO38:5, TG56:5, TG56:6, and TG56:7),TMEM229(LPCO16:1),GCKR(TG50:2), andAPOA1(TG54:4). In addition, we report suggestively significant (P < 5 × 10−8) associations mapping to eleven novel lipid quantitative trait loci (lipQTLs), three of which are supported by mining previous GWAS data:MAU(PC34:4),LDLR(SM16:0), andMLXIPL(TG48:1 and TG50:1)). Genetic correlation analysis indicates that one specific specific sphingomyelin, SM22:0, shares common genetic background with CVD. Levels of SM22:0 also positively associate with carotid artery intima-media thickness in the ERF study, and this observation is independent of LDL-C level. Our findings yield higher resolution of plasma lipid species and new insights in the biology of circulating phosholipids and their relation to CVD risk.
The effect of number of healthcare visits on study sample selection and prevalence estimates in electronic health record data
Authors: Rasmussen-Torvik Laura J. , Furmanchuk Al’ona , Stoddard Alexander J. , Osinski Kristen I. , Meurer John R. , Smith Nicholas , Chrischilles Elizabeth , Black Bernard S. , Kho Abel
Published: May 2019

Introduction

Few studies have addressed how to select a study sample when using electronic health record (EHR) data.

Methods

Year 2016 EHR data from three health systems was used to examine how alternate definitions of the study sample, based on number of healthcare visits in one year, affected measures of disease period prevalence. Curated collections of ICD-9, ICD-10, and SNOMED codes were used to define three diseases.

Results

Across all health systems, increasing the minimum required number of visits to be included in the study sample monotonically increased crude period prevalence estimates. The rate at which prevalence estimates increased with number of visits varied across sites and across diseases.

Conclusions

When using EHR data authors must carefully describe how a study sample is identified and report outcomes for a range of sample definitions, so that others can assess the sensitivity of reported results to sample definition in EHR data.
Genomic and physiological analyses reveal that extremely thermophilicCaldicellulosiruptor changbaiensisdeploys unique cellulose attachment mechanisms
Authors: Khan Asma M.A.M. , Mendoza Carl , Hauk Valerie J. , Blumer-Schuette Sara E.
Published: May 2019

The genusCaldicellulosiruptorare extremely thermophilic, heterotrophic anaerobes that degrade plant biomass using modular, multifunctional enzymes. Prior pangenome analyses determined that this genus is genetically diverse, with the current pangenome remaining open, meaning that new genes are expected with each additional genome sequence added. Given the high biodiversity observed among the genusCaldicellulosiruptor, we have sequenced and added a 14thspecies,Caldicellulosiruptor changbaiensis, to the pangenome. The pangenome now includes 3,791 ortholog clusters, 120 of which are unique toC. changbaiensisand may be involved in plant biomass degradation. Comparisons betweenC. changbaiensisandCaldicellulosiruptor besciion the basis of growth kinetics, cellulose solubilization and cell attachment to polysaccharides highlighted physiological differences between the two species which are supported by their respective gene inventories. Most significantly, these comparisons indicated thatC. changbaiensispossesses unique cellulose attachment mechanisms not observed among the other strongly cellulolytic members of the genusCaldicellulosiruptor.
In vivomicrostructural heterogeneity of white matter lesions in Alzheimer’s disease using tissue compositional analysis of diffusion MRI data
Authors: Mito Remika , Dhollander Thijs , Xia Ying , Raffelt David , Salvado Olivier , Churilov Leonid , Rowe Christopher C , Brodtmann Amy , Villemagne Victor L , Connelly Alan
Published: May 2019

White matter hyperintensities (WMH) are commonly observed in elderly individuals, and are typically more prevalent in Alzheimer’s disease subjects than in healthy subjects. These lesions can be identified on fluid attenuated inversion recovery (FLAIR) MRI, on which they are hyperintense compared to their surroundings. These MRI-visible lesions appear homogeneously hyperintense despite known heterogeneity in their pathological underpinnings, and are commonly regarded as surrogate markers of small vessel disease inin vivostudies. Consequently, the extent to which these lesions contribute to Alzheimer’s disease remains unclear, likely due to the somewhat limited way in which these lesions are assessedin vivo. Diffusion MRI is sensitive to white matter microstructure, and might thus be used to investigate microstructural changes within WMH. In this study, we applied a method called single-shell 3-tissue constrained spherical deconvolution, which models white matter microstructure while also accounting for other tissue compartments, to investigate WMHin vivo. Diffusion MRI data and FLAIR images were obtained from Alzheimer’s disease (n= 48) and healthy elderly control (n= 94) subjects from the Australian Imaging, Biomarkers and Lifestyle study of ageing. WMH were automatically segmented and classified as periventricular or deep lesions from FLAIR images based on their continuity with the lateral ventricles, and the 3-tissue profile of different classes of WMH was characterised by three metrics, which together characterised the relative tissue profile in terms of the white matter-, grey matter-, and fluid-like characteristics of the diffusion signal. Our findings revealed that periventricular and deep lesion classes could be distinguished from one another, and from normal-appearing white matter based on their 3-tissue profile, with substantially higher free water content in periventricular lesions than deep. Given the higher lesion load of periventricular lesions in Alzheimer’s disease patients, the 3-tissue profile of these WMH could be interpreted as reflecting the more deleterious pathological underpinnings that are associated with disease. However, when alternatively classifying lesion sub-regions in terms of distance contours from the ventricles to account for potential heterogeneity within confluent lesions, we found that the highest fluid content was present in lesion areas most proximal to the ventricles, which were common to both Alzheimer’s disease subjects and healthy controls. We argue that whatever classification scheme is used when investigating WMH, failure to account for heterogeneity within lesions may result in classification-scheme dependent conclusions. Future studies of WMH in Alzheimer’s Disease would benefit from inclusion of microstructural information when characterising lesions.
Mitochondrial glycerol phosphate oxidation is modulated by adenylates through allosteric regulation of cytochromecoxidase activity in mosquito flight muscle
Authors: Gaviraghi Alessandro , Correa Soares Juliana B.R. , Mignaco Julio A. , L. Fontes Carlos Frederico , Oliveira Marcus F.
Published: May 2019

The huge energy demand posed by insect flight activity is met by an efficient oxidative phosphorylation process that takes place within flight muscle mitochondria. In the major arbovirus vectorAedes aegypti, mitochondrial oxidation of pyruvate, proline and glycerol 3 phosphate (G3P) represent the major energy sources of ATP to sustain flight muscle energy demand. Although adenylates exert critical regulatory effects on several mitochondrial enzyme activities, the potential consequences of altered adenylate levels to G3P oxidation remains to be determined. Here, we report that mitochondrial G3P oxidation is controlled by adenylates through allosteric regulation of cytochrome c oxidase (COX) activity inA. aegyptiflight muscle. We observed that ADP significantly activated respiratory rates linked to G3P oxidation, in a protonmotive force-independent manner. Kinetic analyses revealed that ADP activates respiration through a slightly cooperative mechanism. Despite adenylates caused no effects on G3P-cytochromecoxidoreductase activity, COX activity was allosterically activated by ADP. Conversely, ATP exerted powerful inhibitory effects on respiratory rates linked to G3P oxidation and on COX activity. We also observed that high energy phosphate recycling mechanisms did not contribute to the regulatory effects of adenylates on COX activity or G3P oxidation. We conclude that mitochondrial G3P oxidation byA. aegyptiflight muscle is regulated by adenylates essentially through the allosteric modulation of COX activity, underscoring the bioenergetic relevance of this novel mechanism and the potential consequences for mosquito dispersal.
Parsing out the variability of transmission at central synapses using optical quantal analysis
Authors: Soares Cary , Trotter Daniel , Longtin André , Béïque Jean-Claude , Naud Richard
Published: May 2019

Properties of synaptic release dictates the core of information transfer in neural circuits. Despite decades of technical and theoretical advances, distinguishing bona fide information content from the multiple sources of synaptic variability remains a challenging problem. Here, we employed a combination of computational approaches with cellular electrophysiology, two-photon uncaging of MNI-Glutamate and imaging at single synapses. We describe and calibrate the use of the fluorescent glutamate sensor iGluSnFR and found that its kinetic profile is close to that of AMPA receptors, therefore providing several distinct advantages over slower methods relying on NMDA receptor activation (i.e., chemical or genetically encoded Calcium indicators). Using an array of statistical methods, we further developed, and validated on surrogate data, an expectation-maximization algorithm that, by biophysically constraining release variability, extracts the quantal parameters n (maximum number of released vesicles) and p (unitary probability of release) from single-synapse iGluSnFR-mediated transients. Together, we present a generalizable mathematical formalism which, when applied to optical recordings, paves the way to an increasingly precise investigation of information transfer at central synapses.
Single cell transcriptomics reveals involution mimicry during the specification of the basal breast cancer subtype
Authors: Valdes-Mora Fatima , Salomon Robert , Gloss Brian , Law Andrew MK. , Castillo Lesley , Murphy Kendelle J. , Venhuizen Jeron , Magenau Astrid , Papanicolau Michael , de la Fuente Laura Rodriguez , Roden Daniel L. , Colino-Sanguino Yolanda , Kikhtyak Zoya , Farbehi Nona , Conway James RW. , Oakes Samantha R. , Sikta Neblina , O’Donoghue Seán I. , Cox Thomas R , Timpson Paul , Ormandy Christopher J. , Gallego-Ortega David
Published: May 2019

Both luminal and basal breast cancer subtypes originate in the mammary luminal progenitor cell compartment. Basal breast cancer is associated with younger age, early relapse, and high mortality rate. Here we used unbiased droplet-based single-cell RNAseq to elucidate the cellular basis of tumour progression during the specification of the basal breast cancer subtype from the luminal progenitor population. Basal–like cancer cells resembled the alveolar lineage that is specified upon pregnancy and showed molecular features indicative of an interaction with the tumour microenvironment (TME) including epithelial-to-mesenchymal transition (EMT), hypoxia, lactation and involution. Involution signatures in luminal breast cancer tumours with alveolar lineage features were associated with worse prognosis and features of basal breast cancer. Our high-resolution molecular characterisation of the tumour ecosystem also revealed a highly interactive cell-cell network reminiscent of an involution process. This involution mimicry involves malignant education of cancer-associated fibroblasts and myeloid cell recruitment to support tissue remodelling and sustained inflammation. Our study shows how luminal breast cancer acquires an aberrant post-lactation developmental program that involves both cancer cells and cells from the TME, to shift molecular subtype and promote tumour progression, with potential to explain the increased risk and poor prognosis of breast cancer associated to childbirth.
Reassessing the Evidence for Universal School-age Bacillus Calmette Guerin (BCG) Vaccination in England and Wales
Authors: Abbott Sam , Christensen Hannah , Brooks-Pollock Ellen
Published: May 2019

Background

In 2005, England and Wales switched from universal BCG vaccination against tuberculosis (TB) disease for school-age children to targeted vaccination of neonates. We assessed the quantitative evidence that informed this policy change.

Methods

We recreated a previous approach for estimating the impact of ending the BCG schools’ scheme in England and Wales, updating the model with parameter uncertainty. We investigated scenarios considered by the UK’s Joint Committee on Vaccination and Immunisation, and explored new approaches using notification data. We estimated the number of vaccines needed to prevent a single notification, and the average annual additional notifications caused by ending the BCG schools’ scheme.

Results

We found a 1.9% annual decrease in TB incidence rates best matched notification data. We estimate that 1600 (2.5-97.5% Quantiles (Q): 1300 - 2100) vaccines would have been required to prevent a single notification in 2004. If the scheme had ended in 2001, 302 (2.5-97.5% Q: 238 - 369) additional annual notifications would have occurred compared to if the scheme had continued. If the scheme ended in 2016, 120 (2.5-97.5% Q: 88 - 155) additional annual notifications would have occurred.

Conclusions

Our estimates of the impact of ending the BCG schools’ scheme were highly sensitive to the annual decrease in incidence rates. The impact of ending the BCG schools’ scheme was found to be greater than previously thought when parameter values were updated and notification data were used. Our results highlight the importance of including uncertainty when forecasting the impact of changes in vaccination policy.

What is already known on this subject

Targeted Bacillus Calmette Guerin (BCG) vaccination against TB is recommended in low incidence countries over universal vaccination.

The impact of replacing universal BCG vaccination in England and Wales with a targeted programme in 2005 was assessed under the assumption of static declines in TB rates.

The BCG Guerin vaccine was shown to be effective in the UK born in England, regardless of the age at which it was given. School-age vaccination maybe more beneficial in this population than in other settings.

What this study adds

Using notification data from England and Wales from 1973 to 2015, we estimate that the ending the BCG schools’ scheme likely resulted in more additional cases than was predicted.

The inclusion of parameter uncertainty, and measurement error, allowed the uncertainty in the final estimates to be presented. Previously published estimates may have been spuriously precise.

This study highlights the need for a more detailed evaluation of the 2005 change in BCG policy. In particular, the impact of including the introduction of targeted neonatal vaccination and capturing the long term, indirect, effects needs further study.
Triphenyl phosphate is a selective PPARγ modulator that does not induce brite adipogenesis in vitro and in vivo
Authors: Kim Stephanie , Rabhi Nabil , Blum Benjamin C. , Hekman Ryan , Wynne Kieran , Emili Andrew , Farmer Stephen , Schlezinger Jennifer J.
Published: May 2019

Triphenyl phosphate (TPhP) is an environmental PPARγ ligand, and growing evidence suggests that it is a metabolic disruptor. We have shown previously that the structurally similar ligand, tributyltin, does not induce brite adipocyte gene expression. Here, using in vivo and in vitro models, we tested the hypothesis that TPhP is a selective PPARγ ligand, which fails to induce brite adipogenesis. C57BL/6J male mice were fed either a low or very high fat diet for 13 weeks. From weeks 7-13, mice were injected intraperitoneally, daily, with vehicle, rosiglitazone (Rosi), or TPhP (10 mg/kg). Compared to Rosi, TPhP did not induce expression of browning-related genes (e.g. Elovl3, Cidea, Acaa2, CoxIV) in mature adipocytes isolated from inguinal adipose. To determine if this resulted from an effect directly on the adipocytes, 3T3-L1 cells and primary human preadipocytes were differentiated into adipocytes in the presence of Rosi or TPhP. Rosi, but not TPhP, induced expression of brite adipocyte genes, mitochondrial biogenesis and cellular respiration. Further, Rosi and TPhP induced distinct proteomes and phosphoproteomes; Rosi enriched more regulatory pathways related to fatty acid oxidation and mitochondrial proteins. We assessed the role of phosphorylation of PPARγ in these differences in 3T3-L1 cells. Only Rosi protected PPARγ from phosphorylation at Ser273. TPhP gained the ability to stimulate brite adipocyte gene expression in the presence of the CDK5 inhibitor and in 3T3-L1 cells expressing alanine at position 273. We conclude that TPhP is a selective PPARγ modulator that fails to protect PPARγ from phosphorylation at ser273.
Microbial community shifts associated with the ongoing stony coral tissue loss disease outbreak on the Florida Reef Tract
Authors: Meyer Julie L. , Castellanos-Gell Jessy , Aeby Greta S. , Häse Claudia , Ushijima Blake , Paul Valerie J.
Published: May 2019

As many as 22 of the 45 coral species on the Florida Reef Tract are currently affected by stony coral tissue loss disease (SCTLD). The ongoing disease outbreak was first observed in 2014 in Southeast Florida near Miami and as of early 2019 has been documented from the northernmost reaches of the reef tract in Martin County down to Key West. We examined the microbiota associated with disease lesions and apparently healthy tissue on diseased colonies of Montastraea cavernosa, Orbicella faveolata, Diploria labyrinthiformis, and Dichocoenia stokesii. Analysis of differentially abundant taxa between disease lesions and apparently healthy tissue identified five unique amplicon sequence variants enriched in the diseased tissue in three of the coral species, namely an unclassified genus of Flavobacteriales and sequences identified as Fusibacter (Clostridiales), Planktotalea (Rhodobacterales), Algicola (Alteromonadales), and Vibrio (Vibrionales). In addition, several groups of likely opportunistic or saprophytic colonizers such as Epsilonbacteraeota, Patescibacteria, Clostridiales, Bacteroidetes, and Rhodobacterales were also enriched in SCTLD disease lesions. This work represents the first microbiological characterization of SCTLD, as an initial step toward identifying the potential pathogen(s) responsible for SCTLD.
A heme-binding protein produced byHaemophilus haemolyticusinhibits non-typeableHaemophilus influenzae
Authors: Latham Roger D. , Torrado Mario , Atto Brianna , Walshe James L. , Wilson Richard , Guss J. Mitchell , Mackay Joel P. , Tristram Stephen , Gell David A.
Published: May 2019

Many commensal bacteria and opportunistic pathogens scavenge heme from their environment. Pathogens and host are engaged in an arms race to control access to heme, but similar conflicts between bacterial species that might regulate pathogen colonisation are largely unknown. We show here that a commensal bacterium,Haemophilus haemolyticus, makes hemophilin, a heme-binding protein that not only allows the bacterium to effectively scavenge heme for its own growth, but also inhibits co-culture of the opportunistic pathogen, non-typeableHaemophilus influenzae(NTHi), by heme starvation. Knockout of the hemophilin gene abrogates the ability ofH. haemolyticusto inhibit NTHi and an x-ray crystal structure shows that hemophilin has a previously unreported heme-binding structure. The bound heme molecule is deeply buried and the heme iron atom is coordinated through a single histidine side chain. Biochemical characterization shows that this arrangement allows heme to be captured in the ferrous or ferric state, and with small ferrous or ferric heme-ligands bound, suggesting hemophilin could function over in a wide range of physiological conditions. Our data raise the possibility that competition for heme between commensal and pathogenic bacteria can influence bacterial colonisation, and therefore disease likelihood, and suggest that strains ofH. haemolyticusthat overproduce hemophilin might have therapeutic uses in reducing colonisation and subsequent opportunistic infection by NTHi.
Two separation-of-function isoforms of human TPP1 and a novel intragenic noncoding RNA dictate telomerase regulation in somatic and germ cells
Authors: Grill Sherilyn , Bisht Kamlesh , Tesmer Valerie M. , Sifuentes Christopher J. , Nandakumar Jayakrishnan
Published: May 2019

Telomerase replicates chromosome ends in germ and somatic stem cells to facilitate continued proliferation. Telomerase action depends on the telomeric protein TPP1, which recruits telomerase to telomeres and facilitates processive DNA synthesis. Here we identify separation-of-function long (TPP1-L) and short (TPP1-S) isoforms of TPP1 differing only in 86 amino acids at their N-terminus. While both isoforms retain the ability to recruit telomerase, only TPP1-S facilitates telomere synthesis. We identify a novel intragenic noncoding RNA in the 3’-UTR of the TPP1-encoding gene that specifically shuts down telomerase activation-incompatible TPP1-L to establish TPP1-S as the predominant isoform in somatic cells. Strikingly, TPP1-L is the major isoform in testes, where it can function to restrain telomerase in mature germ cells. Our studies uncover how differential expression of two isoforms allows TPP1 to perform separate functions in different cells, and demonstrate how isoform choice can be determined by an intragenic noncoding RNA.
Defined cell types in superior colliculus make distinct contributions to prey capture behavior in the mouse
Authors: Hoy Jennifer L. , Bishop Hannah I. , Niell Cristopher M.
Published: May 2019

The superior colliculus (SC) mediates rapid orienting to visual stimuli across species. To determine the specific circuits within the SC that drive orienting and approach behavior toward appetitive stimuli, we explored the role of three genetically defined cell types in mediating prey capture in mice. Chemogenetic inactivation of two classically defined cell types, the wide-field (WF) and narrow-field (NF) vertical neurons, revealed that they are involved in distinct aspects of prey capture. WF neurons were required for rapid prey detection and distant approach initiation, whereas NF neurons were required for continuous and accurate orienting during pursuit. In contrast, prey capture did not require parvalbumin-expressing (PV) neurons that have previously been implicated in fear responses. The visual coding of WF and NF cells in the awake mouse and their projection targets were consistent with their roles in prey detection versus pursuit. Thus, our studies link specific neural circuit connectivity and function with stimulus detection and orienting behavior, providing insight into visuomotor and attentional mechanisms mediated by superior colliculus.

Highlights

This study provides the first demonstration of the role of specific cell populations in the superior colliculus in orienting and approach behavior.

A genetically targeted population of wide-field vertical neurons in the superior colliculus is required for rapid prey detection and initiation of long-distance approaches.

A genetically targeted population of narrow-field vertical neurons is required for approach initiation, accurate targeting, and approach continuity.

Visual response properties and projection targets of these cells are consistent with their role in prey capture, linking neural circuit connectivity and function with behavior.
Human immune cells infiltrate the lesioned spinal cord and impair recovery after spinal cord injury in humanized mice
Authors: Carpenter Randall S. , Jiang Roselyn R. , Brennan Faith H. , Hall Jodie C.E. , Gottipati Manoj K. , Niewiesk Stefan , Popovich Phillip G.
Published: May 2019

Summary Points

Immune compromised mice require ~4 months of engraftment with human umbilical cord blood CD34+ stem cells to develop a full and functional human immune system

The human neuroinflammatory response elicited after spinal cord injury in humanized mice is limited at 2 months post-engraftment but matures by 4 months

Intraspinal neuroinflammation consists of a florid human T cell and macrophage response, and human T cells co-localize with human macrophages

A human intraspinal neuroinflammatory response exacerbates lesion pathology and impairs functional recovery

Humanized mice are a useful tool to help better understand how the human immune system responds to central nervous system (CNS) injury. However, the optimal parameters for using humanized mice in preclinical CNS injury models have not been established. Here, we show that it takes 3-4 months after engraftment of neonatal immune compromised mice with human umbilical cord stem cells to generate a robust human immune system. Indeed, sub-optimal human immune cell responses occurred when humanized mice received spinal contusion injuries at 2 months vs. 4 months post-engraftment. Human T cells directly contact human macrophages within the spinal cord lesion of these mice and the development of a mature human immune system was associated with worse lesion pathology and neurological recovery. Together, data in this report establish an optimal experimental framework for using humanized mice to help translate promising preclinical therapies for CNS injury.
A hydrophobic network: Intersubunit and intercapsomer interactions stabilizing the bacteriophage P22 capsid
Authors: Asija Kunica , Teschke Carolyn M.
Published: May 2019

dsDNA tailed phages and herpesviruses assemble their capsids using coat proteins that have the ubiquitous HK97 fold. Though this fold is common, we do not have a thorough understanding of the different ways viruses adapt it to maintain stability in various environments. The HK97-fold E-loop, which connects adjacent subunits at the outer periphery of capsomers, has been implicated in capsid stability. Here we show that in bacteriophage P22, residue W61 at the tip of the E-loop plays a role in stabilizing procapsids and in maturation. We hypothesize that a hydrophobic pocket is formed by residues I366 and W410 in the P-domain of a neighboring subunit within a capsomer, into which W61 fits like a peg. In addition, W61 likely bridges to residues A91 and L401 in P-domain loops of an adjacent capsomer, thereby linking the entire capsid together with a network of hydrophobic interactions. There is conservation of this hydrophobic network in the distantly related P22-like phages, indicating that this structural feature is likely important for stabilizing this family of phages. Thus, our data shed light on one of the varied elegant mechanisms used in nature to consistently build stable viral genome containers through subtle adaptation of the HK97 fold.

IMPORTANCE

Similarities in assembly reactions and coat protein structures of the dsDNA tailed phages and herpesviruses make phages ideal models to understand capsid assembly and identify potential targets for antiviral drug discovery. The coat protein E-loops of these viruses are involved in both intra-and intercapsomer interactions. In phage P22, hydrophobic interactions peg the coat protein subunits together within a capsomer, where the E-loop hydrophobic residue W61 of one subunit packs into a pocket of hydrophobic residues I366 and W410 of the adjacent subunit. W61 also makes hydrophobic interactions with A91 and L401 of a subunit in an adjacent capsomer. We show these intra-and intercapsomer hydrophobic interactions form a network crucial to capsid stability and proper assembly.
The CXCL12/CXCR4 signalling axis retains neutrophils at inflammatory sites in zebrafish
Authors: Isles Hannah M. , Herman Kimberly , Robertson Anne L. , Loynes Catherine A. , Prince Lynne R. , Elks Philip M. , Renshaw Stephen A.
Published: May 2019

The inappropriate retention of neutrophils in the lung is a major driver of the excessive tissue damage characteristic of respiratory inflammatory diseases including COPD, ARDS and cystic fibrosis. The molecular programmes which orchestrate neutrophil recruitment to inflammatory sites through chemotactic guidance have been well studied. However, how neutrophil sensitivity to these cues is modulated during inflammation resolution is not understood. The identification of neutrophil reverse migration as a mechanism of inflammation resolution and the ability to modulate this therapeutically has identified a new target to treat inflammatory disease. Here we investigate the role of the CXCL12/CXCR4 signalling axis in modulating neutrophil retention at inflammatory sites. We used anin vivotissue injury model to study inflammation using transgenic zebrafish larvae. Expression ofcxcl12aandcxcr4bduring the tissue damage response was assessed usingin situhybridisation and analysis of RNA sequencing data. CRISPR/Cas9 was used to knockdowncxcl12aandcxcr4bin zebrafish larvae. The CXCR4 antagonist AMD3100 was used to block the Cxcl12/Cxcr4 signalling axis pharmacologically. We identified thatcxcr4bandcxcl12aare expressed at the wound site in zebrafish larvae during the inflammatory response. Following tail-fin transection, removal of neutrophils from inflammatory sites is significantly increased incxcr4bandcxcl12aCRISPR knockdown larvae. Pharmacological inhibition of the Cxcl12/Cxcr4 signalling axis accelerates inflammation resolution, an effect caused by an increase in neutrophil reverse migration. The findings of this study suggest that CXCR4/CXCL12 signalling may play an important role in neutrophil retention at inflammatory sites, identifying a potential new target for the therapeutic removal of neutrophils from the lung in chronic inflammatory disease.
Characterization of bulk phosphatidylcholine compositions in human plasma using side-chain resolving lipidomics
Authors: Quell Jan D. , Römisch-Margl Werner , Haid Mark , Krumsiek Jan , Skurk Thomas , Halama Anna , Stephan Nisha , Adamski Jerzy , Hauner Hans , Mook-Kanamori Dennis , Mohney Robert P. , Daniel Hannelore , Suhre Karsten , Kastenmüller Gabi
Published: May 2019

Kit-based assays, such as AbsoluteIDQ™ p150, are widely used in large cohort studies and provide a standardized method to quantify blood concentrations of phosphatidylcholines (PCs). Many disease-relevant associations of PCs were reported using this method. However, their interpretation is hampered by lack of functionally relevant information on the detailed fatty acid side chain compositions as only the total number of carbon atoms and double bonds is identified by the kit. To enable more substantiated interpretations, we characterized these PC sums using the side chain resolving Lipidyzer™ platform, analyzing 223 samples in parallel to the AbsoluteIDQ™. Combining these datasets, we estimated the quantitative composition of PC sums and subsequently tested their replication in an independent cohort. We identified major constituents of 28 PC sums, revealing also various unexpected compositions. As an example, PC 16:0_22:5 accounted for more than 50% of the PC sum with in total 38 carbon atoms and 5 double bonds (PC aa 38:5). For 13 PC sums, we found relatively high abundances of odd-chain fatty acids. In conclusion, our study provides insights in PC compositions in human plasma, facilitating interpretation of existing epidemiological datasets and potentially enabling imputation of PC compositions for future meta-analyses of lipidomics data.
Microtubule Binding Kinetics of Membrane-bound Kinesin Predicts High Motor Copy Numbers on Intracellular Cargo
Authors: Jiang Rui , Vandal Steven , Park SooHyun , Majd Sheereen , Tüzel Erkan , Hancock William O.
Published: May 2019

Bidirectional vesicle transport along microtubules is necessary for cell viability and function, particularly in neurons. When multiple motors are attached to a vesicle, the distance a vesicle travels before dissociating is determined by the race between detachment of the bound motors and attachment of the unbound motors. Motor detachment rate constants (koff) can be measured via single-molecule experiments, but motor reattachment rate constants (kon) are generally unknown, as they involve diffusion through the bilayer, geometrical considerations of the motor tether length, and the intrinsic microtubule binding rate of the motor. To understand motor attachment dynamics during vesicle transport, we quantified the microtubule accumulation rate of fluorescently-labeled kinesin-1 motors in a 2D system where motors were linked to a supported lipid bilayer. From the first-order accumulation rate at varying motor densities, we extrapolated a koff that matched single-molecule measurements, and measured a two-dimensional kon for membrane-bound kinesin-1 motors binding to the microtubule. This kon is consistent with kinesin-1 being able to reach roughly 20 tubulin subunits when attaching to a microtubule. By incorporating cholesterol to reduce membrane diffusivity, we demonstrate that this kon is not limited by the motor diffusion rate, but instead is determined by the intrinsic motor binding rate. For intracellular vesicle trafficking, this two-dimensional kon predicts that long-range transport of 100 nm diameter vesicles requires 35 kinesin-1 motors, suggesting that teamwork between different motor classes and motor clustering may play significant roles in long-range vesicle transport.

Significance Statement

Long-distance transport of membrane-coated vesicles involves coordination of multiple motors such that at least one motor is bound to the microtubule at all times. Microtubule attachment of a membrane-bound motor comprises two steps – diffusing through the lipid bilayer to a binding zone near the microtubule, followed by binding. Using a 2D supported lipid bilayer system, we show that membrane diffusion is not the limiting factor for motor attachment. This result suggests that in cells kinesin-1 binding kinetics are not altered by the membrane composition of vesicle cargos. The intrinsically slow binding properties of kinesin-1 suggest that divergent motor binding kinetics and motor clustering regulate long-range vesicle transport.
Multiple non-auditory cortical regions innervate the auditory midbrain
Authors: Olthof Bas MJ , Rees Adrian , Gartside Sarah E
Published: May 2019

Our perceptual experience of sound depends on the integration of multiple sensory and cognitive domains, but the networks sub-serving this integration are unclear. There are connections linking different cortical domains, however we do not know if there are also connections between multiple cortical domains and subcortical structures. Retrograde tracing in rats revealed that the inferior colliculus – the auditory midbrain - receives dense descending projections from not only the auditory cortex, but also the visual, somatosensory, motor, and prefrontal cortices. While all these descending connections are bilateral, those from sensory areas show a more pronounced ipsilateral dominance than those from motor and prefrontal cortices. Anterograde tracing from cortical areas identified by retrograde tracing, showed cortical fibres terminating in all three subdivisions of the inferior colliculus, targeting both inhibitory and excitatory neurons. These findings demonstrate that auditory perception is served by a network that includes extensive descending connections from sensory, behavioural, and executive cortices.
The rich get richer: synaptic remodeling between climbing fibers and Purkinje cells in the developing cerebellum begins with positive feedback addition of synapses
Authors: Wilson Alyssa Michelle , Schalek Richard , Suissa-Peleg Adi , Jones Thouis Ray , Knowles-Barley Seymour , Pfister Hanspeter , Lichtman Jeff William
Published: May 2019

During postnatal development, cerebellar climbing fibers strongly innervate a subset of their original Purkinje cell targets and eliminate their connections from the rest. In the adult, each climbing fiber innervates a small number of Purkinje cells and each Purkinje cell is innervated by a single climbing fiber. To get insight about the processes responsible for this remapping, we reconstructed serial electron microscopy datasets from mice during the first postnatal week. In contrast to adult connectivity, individual neonatal climbing fibers innervate many nearby Purkinje cells, and multiple climbing fibers innervate each Purkinje cell. Between postnatal days 3 and 7, Purkinje cells retract long dendrites and grow many proximal dendritic processes. On this changing landscape, individual climbing fibers selectively add many synapses to a subset of Purkinje cell targets in a positive-feedback manner, without pruning synapses from other Purkinje cells. The active zone sizes of synapses associated with powerful versus weak inputs are indistinguishable. These results show that changes in synapse number rather than synapse size are the predominant form of early developmental plasticity. Finally, although multiple climbing fibers innervate each Purkinje cell in early postnatal development, the number of climbing fibers and Purkinje cells in a local cerebellar region nearly match. Thus, initial over-innervation of Purkinje cells by climbing fibers is economical, in that the number of axons entering a region is enough to assure that each axon ends up with a postsynaptic target, and that none branched there in vain.

HIGHLIGHTS

Developing climbing fibers establish synapses on many neighboring Purkinje cells unlike the sparse pattern of innervation in later life

Climbing fibers add many synapses onto a few of their Purkinje targets before the pruning stage in a rich-get-richer type process

The synapse sizes of strengthened and weakened climbing fiber inputs are indistinguishable.

Exuberant branching of climbing fiber axons in early postnatal life appears to be economical because the numbers of axons and Purkinje cells in a local region match, ensuring that each axon can establish a long-lasting connection there

BLURB

High-resolution serial electron microscopy reconstructions reveal that climbing fiber-Purkinje cell synaptic refinement in the developing cerebellum begins with significant synapse addition. Climbing fibers focus their synapses onto a smaller number of Purkinje cells by selectively adding synapses onto some target cells. All axons that project to a region in development play a role in the final connectivity.
FOP plays a negative role in ciliogenesis and promotes cell cycle re-entry by facilitating primary cilia disassembly
Authors: Jiang Huadong , Cheung Man-Hei , Amin Aftab , Liang Chun
Published: May 2019

Primary cilia are microtubule-based, antenna-like organelles, which are formed in G0phase and resorbed as cells re-enter the cell cycle. It has been reported that the length of primary cilia can influence the timing of cell cycle progression. However, the molecular links between ciliogenesis and cell cycle progression are not clear. FOP (Fibroblast growth factor receptor 1 Oncogene Partner, also known as FGFR1OP) has been implicated in ciliogenesis. Here, we show that the expression of FOP during cell cycle exit and re-entry is negatively correlated with ciliogenesis. Knockdown of FOP promotes cilia elongation and suppresses timely cilia disassembly. In contrast, ectopic expression of FOP inhibits cilia growth. Moreover, pharmacological inhibition of actin polymerization with Cytochalasin D abrogates FOP-induced cilia disassembly, suggesting that FOP facilitates cilia disassembly by promoting actin cytoskeleton formation. Lastly, knockdown of FOP delays cell cycle re-entry of quiescent cells following serum re-stimulation, and this can be reversed by silencing IFT20 (intraflagellar transport 20), an intraflagellar transport protein essential for ciliogenesis. Collectively, these results suggest that FOP plays a negative role in ciliogenesis and can promote cell cycle re-entry by facilitating cilia disassembly.
CENP-F controls force generation and the dynein-dependent stripping of CENP-E at kinetochores
Authors: Auckland Philip , McAinsh Andrew D.
Published: May 2019

Accurate chromosome segregation demands efficient capture of microtubules by kinetochores and their conversion to stable bi-oriented attachments that can congress and then segregate chromosomes. An early event is the shedding of the outermost fibrous corona layer of the kinetochore following microtubule attachment. Centromere protein F (CENP-F) is part of the corona, contains two microtubule-binding domains and physically associates with dynein motor regulators. Here, we have combined CRISPR gene editing and engineered separation-of-function mutants to define how CENP-F contributes to kinetochore function. We show here that the two microtubule-binding domains make distinct contributions to attachment stability and force generation that are required to minimise errors in anaphase, but are dispensable for congression. We further identify a specialised domain that functions to inhibit the dynein mediated stripping of CENP-E motors. We show how this “dynein-brake” is crucial for ensuring kinetochores contain the right number of CENP-E motors at the right time during mitosis, with loss of brake function delaying congression.
Individual vulnerability to stress is associated with increased demand for intravenous heroin self-administration in rats
Authors: Stafford Nathaniel P. , Kazan Theodore N. , Donovan Colleen M. , Hart Erin E. , Drugan Robert C. , Charntikov Sergios
Published: May 2019

Opioid use is a widespread epidemic, and traumatic stress exposure is a critical risk factor in opioid use and relapse. There is a significant gap in our understanding of how stress contributes to heroin use, and there are limited studies investigating individual differences underlying stress reactivity and subsequent stress-induced heroin self-administration. We hypothesized that greater individual vulnerability to stress would predict higher demand for heroin self-administration in a within-subjects rodent model of stress and heroin use comorbidity. Male rats were exposed to inescapable intermittent swim stress and individual biological (corticosterone) or behavioral (open field, social exploration, and forced swim tests) measures were assessed before and after the stress episode. Individual demand for self-administered heroin (0.05 mg/kg/infusion; 12-hour sessions) was assessed using a behavioral economics approach followed by extinction and reinstatement tests triggered by stress re-exposure, non-contingent cue presentations, and yohimbine (0, 1.0, or 2.5 mg/kg). We found that behavioral, biological, and a combination of behavioral and biological markers sampled prior and after the stress episode that occurred weeks before the access to heroin selfadministration predicted the magnitude of individual demand for heroin. Non-contingent presentation of cues, that were previously associated with heroin, reinstated heroin seeking in extinction. For the first time, we show that individual biological response to an ecologically relevant stressor in combination with associated behavioral markers can be used to predict subsequent economic demand for heroin.
Stem cell-derived cranial and spinal motor neurons reveal proteostatic differences between ALS resistant and sensitive motor neurons
Authors: An Disi , Fujiki Ryosuke , Iannitelli Dylan E. , Smerdon John W. , Maity Shuvadeep , Rose Matthew F. , Gelber Alon , Wanaselja Elizabeth K. , Yagudayeva Ilona , Lee Joun Y. , Vogel Christine , Wichterle Hynek , Engle Elizabeth C. , Mazzoni Esteban O.
Published: May 2019

In amyotrophic lateral sclerosis (ALS) spinal motor neurons (SpMN) progressively degenerate while a subset of cranial motor neurons (CrMN) are spared until late stages of the disease. Using a rapid and efficient protocol to differentiate mouse embryonic stem cells (ESC) to SpMNs and CrMNs, we now report that ESC-derived CrMNs accumulate less human (h)SOD1 and insoluble p62 than SpMNs over time. ESC-derived CrMNs have higher proteasome activity to degrade misfolded proteins and are intrinsically more resistant to chemically-induced proteostatic stress than SpMNs. Chemical and genetic activation of the proteasome rescues SpMN sensitivity to proteostatic stress. In agreement, the hSOD1 G93A mouse model reveals that ALS-resistant CrMNs accumulate less insoluble hSOD1 and p62-containing inclusions than SpMNs. Primary-derived ALS-resistant CrMNs are also more resistant than SpMNs to proteostatic stress. Thus, an ESC-based platform has identified a superior capacity to maintain a healthy proteome as a possible mechanism to resist ALS-induced neurodegeneration.