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Found 37769 matches. Displaying 4641-4650
de Verdiere SC, Noel E, Lozano C, Catherinot E, Martin M, Rivaud E, Couderc LJ, Salvator H, Bustamante J, Martin T
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Respiratory Complications Lead to the Diagnosis of Chronic Granulomatous Disease in Two Adult Patients

JOURNAL OF CLINICAL IMMUNOLOGY 2017 FEB; 37(2):113-116
Chronic granulomatous disease (CGD) is a primary immunodeficiency associated to multiple life-threatening bacterial and fungal infections, beginning in childhood. There are rare cases of diagnosis in adulthood. We describe here two cases of late diagnosis in adults: a 45-year-old woman and 59-year-old-man. CGD diagnosis should be considered in adult patients with unexplained infectious diseases with tissue granuloma.
Ceglia I, Lee KW, Cahill ME, Graves SM, Dietz D, Surmeier DJ, Nestler EJ, Nairn AC, Greengard P, Kim Y
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WAVE1 in neurons expressing the D1 dopamine receptor regulates cellular and behavioral actions of cocaine

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2017 FEB 7; 114(6):1395-1400
Wiskott-Aldrich syndrome protein (WASP) family verprolin homologous protein 1 (WAVE1) regulates actin-related protein 2/3 (Arp2/3) complex-mediated actin polymerization. Our previous studies have found WAVE1 to be inhibited by Cdk5-mediated phosphorylation in brain and to play a role in the regulation of dendritic spine morphology. Herewe report thatmice inwhich WAVE1was knocked out (KO) in neurons expressing the D1 dopamine receptor (D1-KO), but not mice where WAVE1 was knocked out in neurons expressing the D2 dopamine receptor (D2-KO), exhibited a significant decrease in place preference associated with cocaine. In contrast to wild-type (WT) and WAVE1 D2-KO mice, cocaine-induced sensitized locomotor behavior was not maintained in WAVE1 D1-KO mice. After chronic cocaine administration and following withdrawal, an acute cocaine challenge induced WAVE1 activation in striatum, which was assessed by dephosphorylation. The cocaine-induced WAVE1 dephosphorylation was attenuated by coadministration of either a D1 dopamine receptor or NMDA glutamate receptor antagonist. Upon an acute challenge of cocaine following chronic cocaine exposure and withdrawal, we also observed in WT, but not in WAVE1 D1-KO mice, a decrease in dendritic spine density and a decrease in the frequency of excitatory postsynaptic AMPA receptor currents in medium spiny projection neurons expressing the D1 dopamine receptor (D1-MSNs) in the nucleus accumbens. These results suggest that WAVE1 is involved selectively in D1-MSNs in cocaine-evoked neuronal activitymediated feedback regulation of glutamatergic synapses.
Forgacs PB, Frey HP, Velazquez A, Thompson S, Brodie D, Moitra V, Rabani L, Park S, Agarwal S, Falo MC, Schiff ND, Claassen J
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Dynamic regimes of neocortical activity linked to corticothalamic integrity correlate with outcomes in acute anoxic brain injury after cardiac arrest

ANNALS OF CLINICAL AND TRANSLATIONAL NEUROLOGY 2017 FEB; 4(2):119-129
Objective: Recognition of potential for neurological recovery in patients who remain comatose after cardiac arrest is challenging and strains clinical decision making. Here, we utilize an approach that is based on physiological principles underlying recovery of consciousness and show correlation with clinical recovery after acute anoxic brain injury. Methods: A cohort study of 54 patients admitted to an Intensive Care Unit after cardiac arrest who underwent standardized bedside behavioral testing (Coma Recovery Scale -Revised[ CRS-R]) during EEG monitoring. Blinded to all clinical variables, artifact-free EEG segments were selected around maximally aroused states and analyzed using a multi-taper method to assess frequency spectral content. EEG spectral features were assessed based on pre-defined categories that are linked to anterior forebrain corticothalamic integrity. Clinical outcomes were determined at the time of hospital discharge, using Cerebral Performance Categories (CPC). Results: Ten patients with ongoing seizures, myogenic artifacts or technical limitations obscuring recognition of underlying cortical dynamic activity were excluded from primary analysis. Of the 44 remaining patients with distinct EEG spectral features, 39 (88%) fit into our predefined categories. In these patients, spectral features corresponding to higher levels of anterior forebrain corticothalamic integrity correlated with higher levels of consciousness and favorable clinical outcome at the time of hospital discharge (P = 0.014). Interpretation: Predicted transitions of neocortical dynamics that indicate functional integrity of anterior forebrain corticothalamic circuitry correlate with clinical outcomes in postcardiac-arrest patients. Our results support a new biologically driven approach toward better understanding of neurological recovery after cardiac arrest.
Kafkova L, Debler EW, Fisk JC, Jain K, Clarke SG, Read LK
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The Major Protein Arginine Methyltransferase in Trypanosoma brucei Functions as an Enzyme-Prozyme Complex

JOURNAL OF BIOLOGICAL CHEMISTRY 2017 FEB 10; 292(6):2089-2100
Prozymes are catalytically inactive enzyme paralogs that dramatically stimulate the function of weakly active enzymes through complex formation. The two prozymes described to date reside in the polyamine biosynthesis pathway of the human parasite Trypanosoma brucei, an early branching eukaryote that lacks transcriptional regulation and regulates its proteome through posttranscriptional and posttranslational means. Arginine methylation is a common posttranslational modification in eukaryotes catalyzed by protein arginine methyltransferases (PRMTs) that are typically thought to function as homodimers. Wedemonstrate that a major T. brucei PRMT, TbPRMT1, functions as a heterotetrameric enzyme-prozyme pair. The inactive PRMT paralog, TbPRMT1(PRO), is essential for catalytic activity of the TbPRMT1(ENZ) subunit. Mutational analysis definitively demonstrates that TbPRMT1(ENZ) is the cofactor-binding subunit and carries all catalytic activity of the complex. Our results are the first demonstration of an obligate heteromeric PRMT, and they suggest that enzyme-prozyme organization is expanded in trypanosomes as a posttranslational means of enzyme regulation.
Qi YC, Zhang XJ, Renier N, Wu ZH, Atkin T, Sun ZY, Ozair MZ, Tchieu J, Zimmer B, Fattahi F, Ganat Y, Azevedo R, Zeltner N, Briyanlou AH, Karayiorgou M, Gogos J, Tomishima M, Tessier-Lavigne M, Shi SH, Studer L
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Combined small-molecule inhibition accelerates the derivation of functional cortical neurons from human pluripotent stem cells

NATURE BIOTECHNOLOGY 2017 FEB; 35(2):154-163
Considerable progress has been made in converting human pluripotent stem cells (hPSCs) into functional neurons. However, the protracted timing of human neuron specification and functional maturation remains a key challenge that hampers the routine application of hPSC-derived lineages in disease modeling and regenerative medicine. Using a combinatorial small molecule screen, we previously identified conditions to rapidly differentiate hPSCs into peripheral sensory neurons. Here we generalize the approach to central nervous system (CNS) fates by developing a small-molecule approach for accelerated induction of early-born cortical neurons. Combinatorial application of six pathway inhibitors induces post-mitotic cortical neurons with functional electrophysiological properties by day 16 of differentiation, in the absence of glial cell co-culture. The resulting neurons, transplanted at 8 d of differentiation into the postnatal mouse cortex, are functional and establish long-distance projections, as shown using iDISCO whole-brain imaging. Accelerated differentiation into cortical neuron fates should facilitate hPSC-based strategies for disease modeling and cell therapy in CNS disorders.
Coulter TI, Chandra A, Bacon CM, Babar J, Curtis J, Screaton N, Goodlad JR, Farmer G, Steele CL, Leahy TR, Doffinger R, Baxendale H, Bernatoniene J, Edgar JDM, Longhurst HJ, Ehl S, Speckmann C, Grimbacher B, Sediva A, Milota T, Faust SN, Williams AP, Hayman G, Kucuk ZY, Hague R, French P, Brooker R, Forsyth P, Herriot R, Cancrini C, Palma P, Ariganello P, Conlon N, Feighery C, Gavin PJ, Jones A, Imai K, Ibrahim MAA, Markelj G, Abinun M, Rieux-Laucat F, Latour S, Pellier I, Fischer A, Touzot F, Casanova JL, Durandy A, Burns SO, Savic S, Kumararatne DS, Moshous D, Kracker S, Vanhaesebroeck B, Okkenhaug K, Picard C, Nejentsev S, Condliffe AM, Cant AJ
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Clinical spectrum and features of activated phosphoinositide 3-kinase delta syndrome: A large patient cohort study

JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY 2017 FEB; 139(2):597-606.e4
Background: Activated phosphoinositide 3-kinase delta syndrome (APDS) is a recently described combined immunodeficiency resulting from gain-of-function mutations in PIK3CD, the gene encoding the catalytic subunit of phosphoinositide 3-kinase delta (PI3K delta). Objective: We sought to review the clinical, immunologic, histopathologic, and radiologic features of APDS in a large genetically defined international cohort. Methods: We applied a clinical questionnaire and performed review of medical notes, radiology, histopathology, and laboratory investigations of 53 patients with APDS. Results: Recurrent sinopulmonary infections (98%) and nonneoplastic lymphoproliferation (75%) were common, often from childhood. Other significant complications included herpesvirus infections (49%), autoinflammatory disease (34%), and lymphoma (13%). Unexpectedly, neurodevelopmental delay occurred in 19% of the cohort, suggesting a role for PI3K delta in the central nervous system; consistent with this, PI3K delta is broadly expressed in the developing murine central nervous system. Thoracic imaging revealed high rates of mosaic attenuation (90%) and bronchiectasis (60%). Increased IgM levels (78%), IgG deficiency (43%), and CD4 lymphopenia (84%) were significant immunologic features. No immunologic marker reliably predicted clinical severity, which ranged from asymptomatic to death in early childhood. The majority of patients received immunoglobulin replacement and antibiotic prophylaxis, and 5 patients underwent hematopoietic stem cell transplantation. Five patients died from complications of APDS. Conclusion: APDS is a combined immunodeficiency with multiple clinical manifestations, many with incomplete penetrance and others with variable expressivity. The severity of complications in some patients supports consideration of hematopoietic stem cell transplantation for severe childhood disease. Clinical trials of selective PI3K delta inhibitors offer new prospects for APDS treatment.
Schaafsma SM, Gagnidze K, Reyes A, Norstedt N, Mansson K, Francis K, Pfaff DW
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Sex-specific gene-environment interactions underlying ASD-like behaviors

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2017 FEB 7; 114(6):1383-1388
The male bias in the incidence of autism spectrum disorders (ASDs) is one of the most notable characteristics of this group of neurodevelopmental disorders. The etiology of this sex bias is far from known, but pivotal for understanding the etiology of ASDs in general. Here we investigate whether a "three-hit" (genetic load x environmental factor x sex) theory of autism may help explain the male predominance. We found that LPS-induced maternal immune activation caused male-specific deficits in certain social responses in the contactin-associated protein-like 2 (Cntnap2) mouse model for ASD. The three " hits" had cumulative effects on ultrasonic vocalizations at postnatal day 3. Hits synergistically affected social recognition in adulthood: only mice exposed to all three hits showed deficits in this aspect of social behavior. In brains of the same mice we found a significant three-way interaction on corticotropin-releasing hormone receptor-1 (Crhr1) gene expression, in the left hippocampus specifically, which co-occurred with epigenetic alterations in histone H3 N-terminal lysine 4 trimethylation (H3K4me3) over the Crhr1 promoter. Although it is highly likely that multiple (synergistic) interactions may be at work, change in the expression of genes in the hypothalamic-pituitary-adrenal/stress system (e. g., Crhr1) is one of them. The data provide proof-of-principle that genetic and environmental factors interact to cause sex-specific effects that may help explain the male bias in ASD incidence.
Jang H, Levy S, Flavell SW, Mende F, Latham R, Zimmer M, Bargmann CI
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Dissection of neuronal gap junction circuits that regulate social behavior in Caenorhabditis elegans

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2017 FEB 14; 114(7):E1263-E1272
A hub-and-spoke circuit of neurons connected by gap junctions controls aggregation behavior and related behavioral responses to oxygen, pheromones, and food in Caenorhabditis elegans. The molecular composition of the gap junctions connecting RMG hub neurons with sensory spoke neurons is unknown. We show here that the innexin gene unc-9 is required in RMG hub neurons to drive aggregation and related behaviors, indicating that UNC-9containing gap junctions mediate RMG signaling. To dissect the circuit in detail, we developed methods to inhibit unc-9based gap junctions with dominant-negative unc-1 transgenes. unc-1(dn) alters a stomatin-like protein that regulates unc-9 electrical signaling; its disruptive effects can be rescued by a constitutively active UNC-9::GFP protein, demonstrating specificity. Expression of unc-1(dn) in RMG hub neurons, ADL or ASK pheromone-sensing neurons, or URX oxygen-sensing neurons disrupts specific elements of aggregation-related behaviors. In ADL, unc-1(dn) has effects opposite to those of tetanus toxin light chain, separating the roles of ADL electrical and chemical synapses. These results reveal roles of gap junctions in a complex behavior at cellular resolution and provide a tool for similar exploration of other gap junction circuits.
Lv ZY, Rickman KA, Yuan LM, Williams K, Selvam SP, Woosley AN, Howe PH, Ogretmen B, Smogorzewska A, Olsen SK
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S-pombe Uba1-Ubc15 Structure Reveals a Novel Regulatory Mechanism of Ubiquitin E2 Activity

MOLECULAR CELL 2017 FEB 16; 65(4):699-714.e6
Ubiquitin (Ub) E1 initiates the Ub conjugation cascade by activating and transferring Ub to tens of different E2s. How Ub E1 cooperates with E2s that differ substantially in their predicted E1-interacting residues is unknown. Here, we report the structure of S. pombe Uba1 in complex with Ubc15, a Ub E2 with intrinsically low E1- E2 Ub thioester transfer activity. The structure reveals a distinct Ubc15 binding mode that substantially alters the network of interactions at the E1- E2 interface compared to the only other available Ub E1- E2 structure.Structure- function analysis reveals that the intrinsically low activity of Ubc15 largely results from the presence of an acidic residue at its N-terminal region. Notably, Ub E2 N termini are serine/threonine rich in many other Ub E2s, leading us to hypothesize that phosphorylation of these sites may serve as a novel negative regulatory mechanism of Ub E2 activity, which we demonstrate biochemically and in cellbased assays.
Winston ME, Kronauer DJC, Moreau CS
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Early and dynamic colonization of Central America drives speciation in Neotropical army ants

MOLECULAR ECOLOGY 2017 FEB; 26(3):859-870
The emergence of the Isthmus of Panama is one of the most important events in recent geological history, yet its timing and role in fundamental evolutionary processes remain controversial. While the formation of the isthmus was complete around 3 million years ago (Ma), recent studies have suggested prior intercontinental biotic exchange. In particular, the possibility of early intermittent land bridges facilitating colonization constitutes a potential mechanism for speciation and colonization before full closure of the isthmus. To test this hypothesis, we employed genomic methods to study the biogeography of the army ant genus Eciton, a group of keystone arthropod predators in Neotropical rainforests. Army ant colonies are unable to disperse across water and are therefore ideally suited to study the biogeographic impact of land bridge formation. Using a reduced representation genome sequencing approach, we show that all strictly Central American lineages of Eciton diverged from their respective South American sister lineage between 4 and 7 Ma, significantly prior to the complete closure of the isthmus. Furthermore, three of the lineage pairs form extensive and coincident secondary contact zones in Costa Rica and Nicaragua, with no evidence of gene flow. Such a discrete and repeated biogeographic pattern indicates at least two waves of army ant dispersal into Central America that were separated by significant genetic divergence times. Thus, by integrating phylogenomic, population genomic and geographic evidence, we show that early colonization of Central America across the emerging Isthmus of Panama drove parallel speciation in Eciton army ants.