Genome-wide screen for modifiers of Na⁺/K⁺ ATPase alleles identifies critical genetic loci

Background: Mutations affecting the Na+/ K+ ATPase (a.k.a. the sodium-potassium pump) genes cause conditional locomotor phenotypes in flies and three distinct complex neurological diseases in humans. More than 50 mutations have been identified affecting the human ATP1A2 and ATP1A3 genes that are known to cause rapid-onset Dystonia Parkinsonism, familial hemiplegic migraine, alternating hemiplegia of childhood, and variants of familial hemiplegic migraine with neurological complications including seizures and various mood disorders. In flies, mutations affecting the ATPalpha gene have dramatic phenotypes including altered longevity, neural dysfunction, neurodegeneration, myodegeneration, and striking locomotor impairment. Locomotor defects can manifest as conditional bang-sensitive (BS) or temperature-sensitive (TS) paralysis: phenotypes well-suited for genetic screening. Results: We performed a genome-wide deficiency screen using three distinct missense alleles of ATPalpha and conditional locomotor function assays to identify novel modifier loci. A secondary screen confirmed allele-specificity of the interactions and many of the interactions were mapped to single genes and subsequently validated. We successfully identified 64 modifier loci and used classical mutations and RNAi to confirm 50 single gene interactions. The genes identified include those with known function, several with unknown function or that were otherwise uncharacterized, and many loci with no described association with locomotor or Na+/K+ ATPase function. Conclusions: We used an unbiased genome-wide screen to find regions of the genome containing elements important for genetic modulation of ATPalpha dysfunction. We have identified many critical regions and narrowed several of these to single genes. These data demonstrate there are many loci capable of modifying ATPalpha dysfunction, which may provide the basis for modifying migraine, locomotor and seizure dysfunction in animals

Structural and Genetic Studies Demonstrate Neurologic Dysfunction in Triosephosphate Isomerase Deficiency Is Associated with Impaired Synaptic Vesicle Dynamics

Triosephosphate isomerase (TPI) deficiency is a poorly understood disease characterized by hemolytic anemia, cardiomyopathy, neurologic dysfunction, and early death. TPI deficiency is one of a group of diseases known as glycolytic enzymopathies, but is unique for its severe patient neuropathology and early mortality. The disease is caused by missense mutations and dysfunction in the glycolytic enzyme, TPI. Previous studies have detailed structural and catalytic changes elicited by disease-associated TPI substitutions, and samples of patient erythrocytes have yielded insight into patient hemolytic anemia; however, the neuropathophysiology of this disease remains a mystery. This study combines structural, biochemical, and genetic approaches to demonstrate that perturbations of the TPI dimer interface are sufficient to elicit TPI deficiency neuropathogenesis. The present study demonstrates that neurologic dysfunction resulting from TPI deficiency is characterized by synaptic vesicle dysfunction, and can be attenuated with catalytically inactive TPI. Collectively, our findings are the first to identify, to our knowledge, a functional synaptic defect in TPI deficiency derived from molecular changes in the TPI dimer interface

Top-down and bottom-up modulation in processing bimodal face/voice stimuli

<p>Abstract</p> <p>Background</p> <p>Processing of multimodal information is a critical capacity of the human brain, with classic studies showing bimodal stimulation either facilitating or interfering in perceptual processing. Comparing activity to congruent and incongruent bimodal stimuli can reveal sensory dominance in particular cognitive tasks.</p> <p>Results</p> <p>We investigated audiovisual interactions driven by stimulus properties (bottom-up influences) or by task (top-down influences) on congruent and incongruent simultaneously presented faces and voices while ERPs were recorded. Subjects performed gender categorisation, directing attention either to faces or to voices and also judged whether the face/voice stimuli were congruent in terms of gender. Behaviourally, the unattended modality affected processing in the attended modality: the disruption was greater for attended voices. ERPs revealed top-down modulations of early brain processing (30-100 ms) over unisensory cortices. No effects were found on N170 or VPP, but from 180-230 ms larger right frontal activity was seen for incongruent than congruent stimuli.</p> <p>Conclusions</p> <p>Our data demonstrates that in a gender categorisation task the processing of faces dominate over the processing of voices. Brain activity showed different modulation by top-down and bottom-up information. Top-down influences modulated early brain activity whereas bottom-up interactions occurred relatively late.</p

Nematode and Arthropod Genomes Provide New Insights into the Evolution of Class 2 B1 GPCRs

Nematodes and arthropods are the most speciose animal groups and possess Class 2 B1 G-protein coupled receptors (GPCRs). Existing models of invertebrate Class 2 B1 GPCR evolution are mainly centered on Caenorhabditis elegans and Drosophila melanogaster and a few other nematode and arthropod representatives. The present study reevaluates the evolution of metazoan Class 2 B1 GPCRs and orthologues by exploring the receptors in several nematode and arthropod genomes and comparing them to the human receptors. Three novel receptor phylogenetic clusters were identified and designated cluster A, cluster B and PDF-R-related cluster. Clusters A and B were identified in several nematode and arthropod genomes but were absent from D. melanogaster and Culicidae genomes, whereas the majority of the members of the PDF-R-related cluster were from nematodes. Cluster A receptors were nematode and arthropod-specific but shared a conserved gene environment with human receptor loci. Cluster B members were orthologous to human GCGR, PTHR and Secretin members with which they probably shared a common origin. PDF-R and PDF-R related clusters were present in representatives of both nematodes and arthropods. The results of comparative analysis of GPCR evolution and diversity in protostomes confirm previous notions that C. elegans and D. melanogaster genomes are not good representatives of nematode and arthropod phyla. We hypothesize that at least four ancestral Class 2 B1 genes emerged early in the metazoan radiation, which after the protostome-deuterostome split underwent distinct selective pressures that resulted in duplication and deletion events that originated the current Class 2 B1 GPCRs in nematode and arthropod genomes.This work was supported by the Portuguese Foundation for Science and Technology (FCT) project PTDC/BIA-BCM/114395/2009, by the European Regional Development Fund through COMPETE and FCT under the project ‘‘PEst-C/MAR/LA0015/2011.’’ RCF is in receipt of an FCT grant (SFRH/BPD/89811/2012) and JCRC is supported by auxiliary research contract FCT Pluriannual funds attributed to CCMAR. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Remote control of renal physiology by the intestinal neuropeptide pigment-dispersing factor in Drosophila.

The role of the central neuropeptide pigment-dispersing factor (PDF) in circadian timekeeping in Drosophila is remarkably similar to that of vasoactive intestinal peptide (VIP) in mammals. Like VIP, PDF is expressed outside the circadian network by neurons innervating the gut, but the function and mode of action of this PDF have not been characterized. Here we investigate the visceral roles of PDF by adapting cellular and physiological methods to the study of visceral responses to PDF signaling in wild-type and mutant genetic backgrounds. We find that intestinal PDF acts at a distance on the renal system, where it regulates ureter contractions. We show that PdfR, PDFs established receptor, is expressed by the muscles of the excretory system, and present evidence that PdfR-induced cAMP increases underlie the myotropic effects of PDF. These findings extend the similarities between PDF and VIP beyond their shared central role as circadian regulators, and uncover an unexpected endocrine mode of myotropic action for an intestinal neuropeptide on the renal system

De effecten van vaccinatie, het voorkomen van de doelziekten

As a result of improved socio-economic state and related hygiene, and the introduction of the National Vaccination Programme (RVP), the incidence of the target diseases of the RVP is low nowadays. Insight in the occurrence of the diseases remains necessary in order to be able to signal possible secondary effects at an early stage. The vaccination coverage is very high in the Netherlands, but considerable geographic differences exist within the country. Especially in municipalities where groups that reject vaccination on religious ground are clustered, the vaccination coverage is low. Herd immunity can be broken in socially and geographically clustered non-vaccinated groups. On the basis of the occurrence results of the target diseases of the RVP, we give recommendations for the future surveillance of the target diseases of the RVP and invasive meningococcal and pneumococcal infections. Besides continuation of the surveillance, additional research in case of outbreaks and epidemics is recommended, in order to obtain more insight into the circulation of the pathogens.Door verbetering van sociaal-economische omstandigheden en de daarmee samenhangende hygiene, en de invoering van het Rijksvaccinatieprogramma (RVP), komen de doelziekten uit het RVP tegenwoordig weinig meer voor. Inzicht in het voorkomen van de ziekten blijft nodig om zo tijdig mogelijke secundaire effecten van het vaccinatieprogramma te herkennen. De vaccinatiegraad is erg hoog in Nederland maar er zijn grote geografische verschillen binnen het land. Vooral in gemeenten, waar groepen die vaccinatie om religieuze redenen afwijzen, zijn geclusterd, is de vaccinatiegraad laag. De groepsimmuniteit kan worden doorbroken in sociaal en geografisch geclusterde niet-gevaccineerde groepen. Op basis van de resulaten van het voorkomen van de doelziekten uit het RVP geven wij aanbevelingen voor de surveillance van de doelziekten uit het RVP en invasieve meningo- en pneumokokken infecties in de toekomst. Naast voortzetting van de surveillance zoals deze er op dit moment is, wordt aanbevolen additioneel onderzoek te doen bij outbreaks en epidemieen om zodoende meer inzicht te krijgen in de circulatie van de ziekteverwekkers

De effecten van vaccinatie, het voorkomen van de doelziekten

Door verbetering van sociaal-economische omstandigheden en de daarmee samenhangende hygiene, en de invoering van het Rijksvaccinatieprogramma (RVP), komen de doelziekten uit het RVP tegenwoordig weinig meer voor. Inzicht in het voorkomen van de ziekten blijft nodig om zo tijdig mogelijke secundaire effecten van het vaccinatieprogramma te herkennen. De vaccinatiegraad is erg hoog in Nederland maar er zijn grote geografische verschillen binnen het land. Vooral in gemeenten, waar groepen die vaccinatie om religieuze redenen afwijzen, zijn geclusterd, is de vaccinatiegraad laag. De groepsimmuniteit kan worden doorbroken in sociaal en geografisch geclusterde niet-gevaccineerde groepen. Op basis van de resulaten van het voorkomen van de doelziekten uit het RVP geven wij aanbevelingen voor de surveillance van de doelziekten uit het RVP en invasieve meningo- en pneumokokken infecties in de toekomst. Naast voortzetting van de surveillance zoals deze er op dit moment is, wordt aanbevolen additioneel onderzoek te doen bij outbreaks en epidemieen om zodoende meer inzicht te krijgen in de circulatie van de ziekteverwekkers.As a result of improved socio-economic state and related hygiene, and the introduction of the National Vaccination Programme (RVP), the incidence of the target diseases of the RVP is low nowadays. Insight in the occurrence of the diseases remains necessary in order to be able to signal possible secondary effects at an early stage. The vaccination coverage is very high in the Netherlands, but considerable geographic differences exist within the country. Especially in municipalities where groups that reject vaccination on religious ground are clustered, the vaccination coverage is low. Herd immunity can be broken in socially and geographically clustered non-vaccinated groups. On the basis of the occurrence results of the target diseases of the RVP, we give recommendations for the future surveillance of the target diseases of the RVP and invasive meningococcal and pneumococcal infections. Besides continuation of the surveillance, additional research in case of outbreaks and epidemics is recommended, in order to obtain more insight into the circulation of the pathogens.IG

The effects of vaccination, the incidence of the target diseases

Door verbetering van sociaal-economische omstandigheden en de daarmee samenhangende hygiene, en de invoering van het Rijksvaccinatieprogramma (RVP), komen de doelziekten uit het RVP tegenwoordig weinig meer voor. Inzicht in het voorkomen van de ziekten blijft nodig om zo tijdig mogelijke secundaire effecten van het vaccinatieprogramma te herkennen. De vaccinatiegraad is erg hoog in Nederland maar er zijn grote geografische verschillen binnen het land. Vooral in gemeenten, waar groepen die vaccinatie om religieuze redenen afwijzen, zijn geclusterd, is de vaccinatiegraad laag. De groepsimmuniteit kan worden doorbroken in sociaal en geografisch geclusterde niet-gevaccineerde groepen. Op basis van de resulaten van het voorkomen van de doelziekten uit het RVP geven wij aanbevelingen voor de surveillance van de doelziekten uit het RVP en invasieve meningo- en pneumokokken infecties in de toekomst. Naast voortzetting van de surveillance zoals deze er op dit moment is, wordt aanbevolen additioneel onderzoek te doen bij outbreaks en epidemieen om zodoende meer inzicht te krijgen in de circulatie van de ziekteverwekkers.<br