sea Sedimentary and tectonic controls on Lower Carboniferous (Visean) mixed carbonate-siliciclastic deposition in NE England and the Southern North Sea: implications for reservoir architecture By pg.lyellcollection.org Published On :: 2020-05-01T00:30:41-07:00 Discovery of the Breagh gas field in the Southern North Sea (SNS) has demonstrated the potential that the Lower Carboniferous (Visean, 346.7–330.9 Ma) Farne Group reservoirs have to contribute to the UK's future energy mix. New biostratigraphic correlations provide a basis to compare Asbian and Brigantian sedimentary cores from the Breagh Field and age-equivalent sediments exposed on the Northumberland Coast, which has proved critical in gaining an understanding of exploration and development opportunities. Thirteen facies associations characterize the mixed carbonate–siliciclastic system, grouped into: marine, delta front, delta shoreface, lower delta plain and upper delta plain gross depositional environments. The facies associations are interpreted as depositing in a mixed carbonate and siliciclastic fluvio-deltaic environment, and are arranged into coarsening- and cleaning-upward cycles (parasequences) bounded by flooding surfaces. Most cycles are characterized by mouth bars, distributary channels, interdistributary bays and common braided rivers, interpreted as river-dominated deltaic deposits. Some cycles include rare shoreface and tidally-influenced deposits, interpreted as river-dominated and wave- or tide-influenced deltaic deposits. The depositional processes that formed each cycle have important implications for the reservoir net/gross ratio (where this ratio indicates the proportion of sandstone beds in a cycle), thickness and lateral extent. The deltaic deposits were controlled by a combination of tectonic and eustatic (allocyclic) events and delta avulsion (autocyclic) processes, and are likely to reflect a changing tectonic regime, from extension within elongate fault-bounded basins (synrift) to passive regional thermal subsidence (post-rift). Deep incision by the Base Permian Unconformity across the Breagh Field has removed the Westphalian, Namurian and upper Visean, to leave the more prospective thicker clastic reservoirs within closure. Thematic collection: This article is part of the Under-explored plays and frontier basins of the UK continental shelf collection available at: https://www.lyellcollection.org/cc/under-explored-plays-and-frontier-basins-of-the-uk-continental-shelf Full Article
sea Structural evolution of the Breagh area: implications for carboniferous prospectivity of the Mid North Sea High, Southern North Sea By pg.lyellcollection.org Published On :: 2020-05-01T00:30:41-07:00 Exploration success at Breagh demonstrates that western parts of the Mid North Sea High area are prospective despite the absence of an Upper Permian (Rotliegend Group) Leman Sandstone Formation reservoir and source rocks belonging to the Upper Carboniferous Westphalian Coal Measures Group. Detailed seismic and well interpretation shows that the Breagh trap was a long-lived footwall high, the prospectivity of which was enhanced by Variscan folding and uplift, leading to the truncation (subcrop) of Lower Carboniferous reservoirs beneath the Base Permian Unconformity. Its drape (supra-crop) by Upper Permian (Zechstein Super Group) evaporites creates the seal. The complexity of its overburden means that an accurate picture of the Breagh structure only emerges after accurate depth-conversion that takes the effects of the Mesozoic graben into account. Pronounced easterly tilting during the Cenozoic affected the area and controlled gas migration into the structure from palaeostructures lying to the east. However, evidence that Breagh is not filled to spill point (underfill) suggests that charge limitation remained an issue. The study demonstrates that a poorly-documented and under-explored Lower Carboniferous play exists in Southern North Sea, which relies upon careful structural mapping and basin modelling to be undertaken for the play to be understood and its further potential to be realized. Thematic collection: This article is part of the Under-explored plays and frontier basins of the UK continental shelf collection available at: https://www.lyellcollection.org/cc/under-explored-plays-and-frontier-basins-of-the-uk-continental-shelf Full Article
sea Structural and stratigraphic evolution of the Mid North Sea High region of the UK Continental Shelf By pg.lyellcollection.org Published On :: 2020-05-01T00:30:41-07:00 Interpretation of newly acquired seismic and legacy well data has led to a greater understanding of the Upper Paleozoic–Recent geological evolution of the Mid North Sea High (MNSH), an under-explored region of the North Sea. The position of granite-cored blocks controlled the distribution of Devono-Carboniferous highs and basins before Variscan uplift led to peneplanation and the creation of the Base Permian Unconformity. The MNSH became the dominant feature during the Permian when it formed a west–east-striking ridge between the Southern and Northern Permian basins. Following a period of non-deposition, sedimentation was renewed in the Late Permian–Triassic before Middle Jurassic doming caused uplift to the NE. Subsequent Late Jurassic North Sea rifting transected the MNSH to create the Western Platform between the Central Graben and Moray Firth rift arms. Following Cretaceous post-rift deposition, the area experienced a significant easterly tilt in the Cenozoic that led to the demise of the MNSH as a prominent topographical feature. The tectonic and stratigraphic evolution exerts a strong control over reservoir facies distribution, source-rock deposition and maturation. However, the area is not barren of petroleum potential. Despite the lack of Upper Carboniferous source rocks over large areas, hydrocarbon potential is evident through shows in legacy wells, indicating the Lower Carboniferous as a potential source rock. Cenozoic uplift to the west imparted a regional tilt, the effects of which remains key to unlocking the area's prospectivity since it reconfigured structures and formed remigration pathways from Lower Carboniferous and Jurassic source rocks. Thematic collection: This article is part of the Under-explored plays and frontier basins of the UK continental shelf collection available at: https://www.lyellcollection.org/cc/under-explored-plays-and-frontier-basins-of-the-uk-continental-shelf Full Article
sea Single-cycle rituximab-induced immunologic changes in children: Enhanced in neuroimmunologic disease? By nn.neurology.org Published On :: 2020-05-06T12:45:12-07:00 Objective To investigate the immunologic impact of a single cycle of rituximab (RTX) in children and adolescents with immune-mediated disorders, we evaluated B cells and immunoglobulin levels of 20 patients with neuroimmunologic, nephrologic, dermatologic, and rheumatologic disorders treated under recommended guidelines. Methods Retrospective study of immunologic changes in children (aged ≤18 years) diagnosed with immune-mediated disorders in which RTX was prescribed between June 2014 and February 2019. Patients were excluded if they had prior diagnosis of malignant disease or primary immunodeficiency. Patients were clinically and immunologically followed up every 3 months. Only patients having received a single cycle of RTX and with a follow-up greater than 12 months were included in the analysis of persistent dysgammaglobulinemia. Results Twenty children were included. Median age at RTX treatment was 12.8 years (interquartile range [IQR] 6.6–15.5 years). Median follow-up was 12.6 months (IQR 10.2–24 months). Of the 14 patients eligible for persistent dysgammaglobulinemia analysis (3 had received RTX retreatment, 2 had <12 months post-RTX follow-up, and in 1 data for this time point was missing), 2/14 (14%) remained with complete B-cell depletion, and 5/14 (36%) had dysgammaglobulinemia. Patients with dysgammaglobulinemia were younger (7.8 vs 15.6 years, p = 0.072), had more underlying neuroimmunologic diseases (5/5 vs 0/9, p < 0.001), and had received more frequently concentrated doses of RTX (3/5 vs 1/9, p = 0.05) than patients without dysgammaglobulinemia. Kinetics of immunoglobulins in the 20 patients revealed a decrease as early as 3 months after RTX in patients with neuroimmunologic disorders. Conclusion In our cohort, single-cycle RTX-induced dysgammaglobulinemia was enhanced in patients with neuroimmunologic diseases. Further studies are needed to confirm this observation. Full Article
sea Monitoring of radiologic disease activity by serum neurofilaments in MS By nn.neurology.org Published On :: 2020-04-09T14:01:03-07:00 Objective To determine whether serum neurofilament light chain (sNfL) levels are associated with recent MRI activity in patients with relapsing-remitting MS (RRMS). Methods This observational study included 163 patients (405 samples) with early RRMS from the Study of Early interferon-beta1a (IFN-β1a) Treatment (SET) cohort and 179 patients (664 samples) with more advanced RRMS from the Genome-Wide Association Study of Multiple Sclerosis (GeneMSA) cohort. Based on annual brain MRI, we assessed the ability of sNfL cutoffs to reflect the presence of combined unique active lesions, defined as new/enlarging lesion compared with MRI in the preceding year or contrast-enhancing lesion. The probability of active MRI lesions among patients with different sNfL levels was estimated with generalized estimating equations models. Results From the sNfL samples ≥90th percentile, 81.6% of the SET (OR = 3.4, 95% CI = 1.8-6.4) and 48.9% of the GeneMSA cohort samples (OR = 2.6, 95% CI = 1.7-3.9) was associated with radiological disease activity on MRI. The sNfL level between the 10th and 30th percentile was reflective of negligible MRI activity: 1.4% (SET) and 6.5% (GeneMSA) of patients developed ≥3 active lesions, 5.8% (SET) and 6.5% (GeneMSA) developed ≥2 active lesions, and 34.8% (SET) and 11.8% (GeneMSA) showed ≥1 active lesion on brain MRI. The sNfL level <10th percentile was associated with even lower MRI activity. Similar results were found in a subgroup of clinically stable patients. Conclusions Low sNfL levels (≤30th percentile) help identify patients with MS with very low probability of recent radiologic disease activity during the preceding year. This result suggests that in future, sNfL assessment may substitute the need for annual brain MRI monitoring in considerable number (23.1%–36.4%) of visits in clinically stable patients. Full Article
sea A Fully Automated Multiplex Assay for Diagnosis of Lyme Disease with High Specificity and Improved Early Sensitivity [Immunoassays] By jcm.asm.org Published On :: 2020-04-23T08:00:29-07:00 Lyme borreliosis is a tick-borne disease caused by the Borrelia burgdorferi sensu lato complex. Bio-Rad Laboratories has developed a fully automated multiplex bead-based assay for the detection of IgM and IgG antibodies to B. burgdorferi. The BioPlex 2200 Lyme Total assay exhibits an improved rate of seropositivity in patients with early Lyme infection. Asymptomatic subjects from endemic and nonendemic origins demonstrated a seroreactivity rate of approximately 4% that was similar to other commercial assays evaluated in this study. Coupled to this result was the observation that the Lyme Total assay retained a high first-tier specificity of 96% while demonstrating a relatively high sensitivity of 91% among a well-characterized CDC Premarketing Lyme serum panel. The Lyme Total assay also performs well under a modified two-tier algorithm (sensitivity, 84.4 to 88.9%; specificity, 98.4 to 99.5%). Furthermore, the new assay is able to readily detect early Lyme infection in patient samples from outside North America. Full Article
sea Impact of Changes in Clinical Microbiology Laboratory Location and Ownership on the Practice of Infectious Diseases [Epidemiology] By jcm.asm.org Published On :: 2020-04-23T08:00:28-07:00 The number of onsite clinical microbiology laboratories in hospitals is decreasing, likely related to the business model for laboratory consolidation and labor shortages, and this impacts a variety of clinical practices, including that of banking isolates for clinical or epidemiologic purposes. To determine the impact of these trends, infectious disease (ID) physicians were surveyed regarding their perceptions of offsite services. Clinical microbiology practices for retention of clinical isolates for future use were also determined. Surveys were sent to members of the Infectious Diseases Society of America’s (IDSA) Emerging Infections Network (EIN). The EIN is a sentinel network of ID physicians who care for adult and/or pediatric patients in North America and who are members of IDSA. The response rate was 763 (45%) of 1,680 potential respondents. Five hundred forty (81%) respondents reported interacting with the clinical microbiology laboratory. Eighty-six percent of respondents thought an onsite laboratory very important for timely diagnostic reporting and ongoing communication with the clinical microbiologist. Thirty-five percent practiced in institutions where the core microbiology laboratory has been moved offsite, and an additional 7% (n = 38) reported that movement of core laboratory functions offsite was being considered. The respondents reported that only 24% of laboratories banked all isolates, with the majority saving isolates for less than 30 days. Based on these results, the trend toward centralized core laboratories negatively impacts the practice of ID physicians, potentially delays effective implementation of prompt and targeted care for patients with serious infections, and similarly adversely impacts infection control epidemiologic investigations. Full Article
sea Pharmacy-Based Infectious Disease Management Programs Incorporating CLIA-Waived Point-of-Care Tests [Minireviews] By jcm.asm.org Published On :: 2020-04-23T08:00:28-07:00 There are roughly 48,000 deaths caused by influenza annually and an estimated 200,000 people who have undiagnosed human immunodeficiency virus (HIV). These are examples of acute and chronic illnesses that can be identified by employing a CLIA-waived test. Pharmacies across the country have been incorporating CLIA-waived point-of-care tests (POCT) into disease screening and management programs offered in the pharmacy. The rationale behind these programs is discussed. Additionally, a summary of clinical data for some of these programs in the infectious disease arena is provided. Finally, we discuss the future potential for CLIA-waived POCT-based programs in community pharmacies. Full Article
sea Arabidopsis retrotransposon virus-like particles and their regulation by epigenetically activated small RNA [RESEARCH] By genome.cshlp.org Published On :: 2020-04-27T12:09:24-07:00 In Arabidopsis, LTR retrotransposons are activated by mutations in the chromatin gene DECREASE in DNA METHYLATION 1 (DDM1), giving rise to 21- to 22-nt epigenetically activated siRNA (easiRNA) that depend on RNA DEPENDENT RNA POLYMERASE 6 (RDR6). We purified virus-like particles (VLPs) from ddm1 and ddm1rdr6 mutants in which genomic RNA is reverse transcribed into complementary DNA. High-throughput short-read and long-read sequencing of VLP DNA (VLP DNA-seq) revealed a comprehensive catalog of active LTR retrotransposons without the need for mapping transposition, as well as independent of genomic copy number. Linear replication intermediates of the functionally intact COPIA element EVADE revealed multiple central polypurine tracts (cPPTs), a feature shared with HIV in which cPPTs promote nuclear localization. For one member of the ATCOPIA52 subfamily (SISYPHUS), cPPT intermediates were not observed, but abundant circular DNA indicated transposon "suicide" by auto-integration within the VLP. easiRNA targeted EVADE genomic RNA, polysome association of GYPSY (ATHILA) subgenomic RNA, and transcription via histone H3 lysine-9 dimethylation. VLP DNA-seq provides a comprehensive landscape of LTR retrotransposons and their control at transcriptional, post-transcriptional, and reverse transcriptional levels. Full Article
sea Rapid evolution of piRNA-mediated silencing of an invading transposable element was driven by abundant de novo mutations [RESEARCH] By genome.cshlp.org Published On :: 2020-04-27T12:09:24-07:00 The regulation of transposable element (TE) activity by small RNAs is a ubiquitous feature of germlines. However, despite the obvious benefits to the host in terms of ensuring the production of viable gametes and maintaining the integrity of the genomes they carry, it remains controversial whether TE regulation evolves adaptively. We examined the emergence and evolutionary dynamics of repressor alleles after P-elements invaded the Drosophila melanogaster genome in the mid-twentieth century. In many animals including Drosophila, repressor alleles are produced by transpositional insertions into piRNA clusters, genomic regions encoding the Piwi-interacting RNAs (piRNAs) that regulate TEs. We discovered that ~94% of recently collected isofemale lines in the Drosophila melanogaster Genetic Reference Panel (DGRP) contain at least one P-element insertion in a piRNA cluster, indicating that repressor alleles are produced by de novo insertion at an exceptional rate. Furthermore, in our sample of approximately 200 genomes, we uncovered no fewer than 80 unique P-element insertion alleles in at least 15 different piRNA clusters. Finally, we observe no footprint of positive selection on P-element insertions in piRNA clusters, suggesting that the rapid evolution of piRNA-mediated repression in D. melanogaster was driven primarily by mutation. Our results reveal for the first time how the unique genetic architecture of piRNA production, in which numerous piRNA clusters can encode regulatory small RNAs upon transpositional insertion, facilitates the nonadaptive rapid evolution of repression. Full Article
sea Noncoding regions underpin avian bill shape diversification at macroevolutionary scales [RESEARCH] By genome.cshlp.org Published On :: 2020-04-27T12:09:24-07:00 Recent progress has been made in identifying genomic regions implicated in trait evolution on a microevolutionary scale in many species, but whether these are relevant over macroevolutionary time remains unclear. Here, we directly address this fundamental question using bird beak shape, a key evolutionary innovation linked to patterns of resource use, divergence, and speciation, as a model trait. We integrate class-wide geometric-morphometric analyses with evolutionary sequence analyses of 10,322 protein-coding genes as well as 229,001 genomic regions spanning 72 species. We identify 1434 protein-coding genes and 39,806 noncoding regions for which molecular rates were significantly related to rates of bill shape evolution. We show that homologs of the identified protein-coding genes as well as genes in close proximity to the identified noncoding regions are involved in craniofacial embryo development in mammals. They are associated with embryonic stem cell pathways, including BMP and Wnt signaling, both of which have repeatedly been implicated in the morphological development of avian beaks. This suggests that identifying genotype-phenotype association on a genome-wide scale over macroevolutionary time is feasible. Although the coding and noncoding gene sets are associated with similar pathways, the actual genes are highly distinct, with significantly reduced overlap between them and bill-related phenotype associations specific to noncoding loci. Evidence for signatures of recent diversifying selection on our identified noncoding loci in Darwin finch populations further suggests that regulatory rather than coding changes are major drivers of morphological diversification over macroevolutionary times. Full Article
sea Suppressor mutations in Mecp2-null mice implicate the DNA damage response in Rett syndrome pathology [RESEARCH] By genome.cshlp.org Published On :: 2020-04-27T12:09:24-07:00 Mutations in X-linked methyl-CpG-binding protein 2 (MECP2) cause Rett syndrome (RTT). To identify functional pathways that could inform therapeutic entry points, we carried out a genetic screen for secondary mutations that improved phenotypes in Mecp2/Y mice after mutagenesis with N-ethyl-N-nitrosourea (ENU). Here, we report the isolation of 106 founder animals that show suppression of Mecp2-null traits from screening 3177 Mecp2/Y genomes. Whole-exome sequencing, genetic crosses, and association analysis identified 22 candidate genes. Additional lesions in these candidate genes or pathway components associate variant alleles with phenotypic improvement in 30 lines. A network analysis shows that 63% of the genes cluster into the functional categories of transcriptional repression, chromatin modification, or DNA repair, delineating a pathway relationship with MECP2. Many mutations lie in genes that modulate synaptic signaling or lipid homeostasis. Mutations in genes that function in the DNA damage response (DDR) also improve phenotypes in Mecp2/Y mice. Association analysis was successful in resolving combinatorial effects of multiple loci. One line, which carries a suppressor mutation in a gene required for cholesterol synthesis, Sqle, carries a second mutation in retinoblastoma binding protein 8, endonuclease (Rbbp8, also known as CtIP), which regulates a DDR choice in double-stranded break (DSB) repair. Cells from Mecp2/Y mice have increased DSBs, so this finding suggests that the balance between homology-directed repair and nonhomologous end joining is important for neuronal cells. In this and other lines, two suppressor mutations confer greater improvement than one alone, suggesting that combination therapies could be effective in RTT. Full Article
sea Leveraging mouse chromatin data for heritability enrichment informs common disease architecture and reveals cortical layer contributions to schizophrenia [RESEARCH] By genome.cshlp.org Published On :: 2020-04-27T12:09:23-07:00 Genome-wide association studies have implicated thousands of noncoding variants across common human phenotypes. However, they cannot directly inform the cellular context in which disease-associated variants act. Here, we use open chromatin profiles from discrete mouse cell populations to address this challenge. We applied stratified linkage disequilibrium score regression and evaluated heritability enrichment in 64 genome-wide association studies, emphasizing schizophrenia. We provide evidence that mouse-derived human open chromatin profiles can serve as powerful proxies for difficult to obtain human cell populations, facilitating the illumination of common disease heritability enrichment across an array of human phenotypes. We demonstrate that signatures from discrete subpopulations of cortical excitatory and inhibitory neurons are significantly enriched for schizophrenia heritability with maximal enrichment in cortical layer V excitatory neurons. We also show that differences between schizophrenia and bipolar disorder are concentrated in excitatory neurons in cortical layers II-III, IV, and V, as well as the dentate gyrus. Finally, we leverage these data to fine-map variants in 177 schizophrenia loci nominating variants in 104/177. We integrate these data with transcription factor binding site, chromatin interaction, and validated enhancer data, placing variants in the cellular context where they may modulate risk. Full Article
sea Redundant and specific roles of cohesin STAG subunits in chromatin looping and transcriptional control [RESEARCH] By genome.cshlp.org Published On :: 2020-04-27T12:09:23-07:00 Cohesin is a ring-shaped multiprotein complex that is crucial for 3D genome organization and transcriptional regulation during differentiation and development. It also confers sister chromatid cohesion and facilitates DNA damage repair. Besides its core subunits SMC3, SMC1A, and RAD21, cohesin in somatic cells contains one of two orthologous STAG subunits, STAG1 or STAG2. How these variable subunits affect the function of the cohesin complex is still unclear. STAG1- and STAG2-cohesin were initially proposed to organize cohesion at telomeres and centromeres, respectively. Here, we uncover redundant and specific roles of STAG1 and STAG2 in gene regulation and chromatin looping using HCT116 cells with an auxin-inducible degron (AID) tag fused to either STAG1 or STAG2. Following rapid depletion of either subunit, we perform high-resolution Hi-C, gene expression, and sequential ChIP studies to show that STAG1 and STAG2 do not co-occupy individual binding sites and have distinct ways by which they affect looping and gene expression. These findings are further supported by single-molecule localizations via direct stochastic optical reconstruction microscopy (dSTORM) super-resolution imaging. Since somatic and congenital mutations of the STAG subunits are associated with cancer (STAG2) and intellectual disability syndromes with congenital abnormalities (STAG1 and STAG2), we verified STAG1-/STAG2-dependencies using human neural stem cells, hence highlighting their importance in particular disease contexts. Full Article
sea Learning-induced mRNA alterations in olfactory bulb mitral cells in neonatal rats [RESEARCH] By learnmem.cshlp.org Published On :: 2020-04-15T06:30:12-07:00 In the olfactory bulb, a cAMP/PKA/CREB-dependent form of learning occurs in the first week of life that provides a unique mammalian model for defining the epigenetic role of this evolutionarily ancient plasticity cascade. Odor preference learning in the week-old rat pup is rapidly induced by a 10-min pairing of odor and stroking. Memory is demonstrable at 24 h, but not 48 h, posttraining. Using this paradigm, pups that showed peppermint preference 30 min posttraining were sacrificed 20 min later for laser microdissection of odor-encoding mitral cells. Controls were given odor only. Microarray analysis revealed that 13 nonprotein-coding mRNAs linked to mRNA translation and splicing and 11 protein-coding mRNAs linked to transcription differed with odor preference training. MicroRNA23b, a translation inhibitor of multiple plasticity-related mRNAs, was down-regulated. Protein-coding transcription was up-regulated for Sec23b, Clic2, Rpp14, Dcbld1, Magee2, Mstn, Fam229b, RGD1566265, and Mgst2. Gng12 and Srcg1 mRNAs were down-regulated. Increases in Sec23b, Clic2, and Dcbld1 proteins were confirmed in mitral cells in situ at the same time point following training. The protein-coding changes are consistent with extracellular matrix remodeling and ryanodine receptor involvement in odor preference learning. A role for CREB and AP1 as triggers of memory-related mRNA regulation is supported. The small number of gene changes identified in the mitral cell input/output link for 24 h memory will facilitate investigation of the nature, and reversibility, of changes supporting temporally restricted long-term memory. Full Article
sea Systems consolidation impairs behavioral flexibility [RESEARCH] By learnmem.cshlp.org Published On :: 2020-04-15T06:30:12-07:00 Behavioral flexibility is important in a changing environment. Previous research suggests that systems consolidation, a long-term poststorage process that alters memory traces, may reduce behavioral flexibility. However, exactly how systems consolidation affects flexibility is unknown. Here, we tested how systems consolidation affects: (1) flexibility in response to value changes and (2) flexibility in response to changes in the optimal sequence of actions. Mice were trained to obtain food rewards in a Y-maze by switching nose pokes between three arms. During initial training, all arms were rewarded and mice simply had to switch arms in order to maximize rewards. Then, after either a 1 or 28 d delay, we either devalued one arm, or we reinforced a specific sequence of pokes. We found that after a 1 d delay mice adapted relatively easily to the changes. In contrast, mice given a 28 d delay struggled to adapt, especially for changes to the optimal sequence of actions. Immediate early gene imaging suggested that the 28 d mice were less reliant on their hippocampus and more reliant on their medial prefrontal cortex. These data suggest that systems consolidation reduces behavioral flexibility, particularly for changes to the optimal sequence of actions. Full Article
sea Checking responses of goal- and sign-trackers are differentially affected by threat in a rodent analog of obsessive-compulsive disorder [RESEARCH] By learnmem.cshlp.org Published On :: 2020-04-15T06:30:12-07:00 In obsessive–compulsive disorder (OCD), functional behaviors such as checking that a door is locked become dysfunctional, maladaptive, and debilitating. However, it is currently unknown how aversive and appetitive motivations interact to produce functional and dysfunctional behavior in OCD. Here we show a double dissociation in the effects of anxiogenic cues and sensitivity to rewarding stimuli on the propensity to develop functional and dysfunctional checking behavior in a rodent analog of OCD, the observing response task (ORT). While anxiogenic manipulations of perceived threat (presentation of threat-associated contextual cues) and actual threat (punishment of incorrect responding on the ORT) enhanced functional checking, dysfunctional checking was unaffected. In contrast, rats that had previously been identified as "sign-trackers" on an autoshaping task—and therefore were highly sensitive to the incentive salience of appetitive environmental cues—selectively showed elevated levels of dysfunctional checking under a range of conditions, but particularly so under conditions of uncertainty. These data indicate that functional and dysfunctional checking are dissociable and supported by aversive and appetitive motivational processes, respectively. While functional checking is modulated by perceived and actual threat, dysfunctional checking recruits appetitive motivational processes, possibly akin to the "incentive habits" that contribute to drug-seeking in addiction. Full Article
sea Rapid acquisition through fast mapping: stable memory over time and role of prior knowledge [RESEARCH] By learnmem.cshlp.org Published On :: 2020-04-15T06:30:12-07:00 In recent years, there have been intensive debates on whether healthy adults acquire new word knowledge through fast mapping (FM) by a different mechanism from explicit encoding (EE). In this study, we focused on this issue and investigated to what extent retention interval, prior knowledge (PK), and lure type modulated memory after FM and EE. Healthy young participants were asked to learn novel word-picture associations through both FM and EE. Half of the pictures were from familiar categories (i.e., high PK) and the other half were from unfamiliar categories (i.e., low PK). After 10 min and 1 wk, the participants were tested by forced-choice (FC) tasks, with lures from different categories (Experiment 1) or from the same categories of the target pictures (Experiment 2). Pseudowords were used to denote names of the novel pictures and baseline performance was controlled for each task. The results showed that in both Experiments 1 and 2, memory performance remained stable after FM, while it declined after EE from 10 min to 1 wk. Moreover, the effect of PK appeared at 10 min after FM while at 1 wk after EE in Experiment 2. PK enhanced memory of word-picture associations when the lures were from the same categories (Experiment 2), rather than from different categories (Experiment 1). These results were largely confirmed in Experiment 3 when encoding condition was manipulated as a between-subjects factor, while lure type as a within-subjects factor. The findings suggest that different from EE, FM facilitates rapid acquisition and consolidation of word-picture knowledge, and highlight that PK plays an important role in this process by enhancing access to detailed information. Full Article
sea The mammalian cytosolic thioredoxin reductase pathway acts via a membrane protein to reduce ER-localised proteins [RESEARCH ARTICLE] By jcs.biologists.org Published On :: 2020-04-30T01:09:45-07:00 Xiaofei Cao, Sergio Lilla, Zhenbo Cao, Marie Anne Pringle, Ojore B. V. Oka, Philip J. Robinson, Tomasz Szmaja, Marcel van Lith, Sara Zanivan, and Neil J. Bulleid Folding of proteins entering the mammalian secretory pathway requires the insertion of the correct disulfides. Disulfide formation involves both an oxidative pathway for their insertion and a reductive pathway to remove incorrectly formed disulfides. Reduction of these disulfides is crucial for correct folding and degradation of misfolded proteins. Previously, we showed that the reductive pathway is driven by NADPH generated in the cytosol. Here, by reconstituting the pathway using purified proteins and ER microsomal membranes, we demonstrate that the thioredoxin reductase system provides the minimal cytosolic components required for reducing proteins within the ER lumen. In particular, saturation of the pathway and its protease sensitivity demonstrates the requirement for a membrane protein to shuttle electrons from the cytosol to the ER. These results provide compelling evidence for the crucial role of the cytosol in regulating ER redox homeostasis, ensuring correct protein folding and facilitating the degradation of misfolded ER proteins. Full Article
sea The ubiquitin hydrolase Doa4 directly binds Snf7 to inhibit recruitment of ESCRT-III remodeling factors in S. cerevisiae [RESEARCH ARTICLE] By jcs.biologists.org Published On :: 2020-04-28T08:24:46-07:00 Dalton Buysse, Anna-Katharina Pfitzner, Matt West, Aurelien Roux, and Greg Odorizzi The ESCRT-III protein complex executes reverse-topology membrane scission. The scission mechanism is unclear but is linked to remodeling of ESCRT-III complexes at the membrane surface. At endosomes, ESCRT-III mediates the budding of intralumenal vesicles (ILVs). In Saccharomyces cerevisiae, ESCRT-III activity at endosomes is regulated through an unknown mechanism by Doa4, an ubiquitin hydrolase that deubiquitylates transmembrane proteins sorted into ILVs. We report that the non-catalytic N-terminus of Doa4 binds Snf7, the predominant ESCRT-III subunit. Through this interaction, Doa4 overexpression alters Snf7 assembly status and inhibits ILV membrane scission. In vitro, the Doa4 N-terminus inhibits association of Snf7 with Vps2, which functions with Vps24 to arrest Snf7 polymerization and remodel Snf7 polymer structure. In vivo, Doa4 overexpression inhibits Snf7 interaction with Vps2 and also with the ATPase Vps4, which is recruited by Vps2 and Vps24 to remodel ESCRT-III complexes by catalyzing subunit turnover. Our data suggest a mechanism by which the deubiquitylation machinery regulates ILV biogenesis by interfering with ESCRT-III remodeling. Full Article
sea Characterization of unconventional kinetochore kinases KKT10 and KKT19 in Trypanosoma brucei [RESEARCH ARTICLE] By jcs.biologists.org Published On :: 2020-04-29T03:28:24-07:00 Midori Ishii and Bungo Akiyoshi The kinetochore is a macromolecular protein complex that drives chromosome segregation in eukaryotes. Unlike most eukaryotes that have canonical kinetochore proteins, evolutionarily divergent kinetoplastids, such as Trypanosoma brucei, have unconventional kinetochore proteins. T. brucei also lacks a canonical spindle checkpoint system, and it therefore remains unknown how mitotic progression is regulated in this organism. Here, we characterized, in the procyclic form of T. brucei, two paralogous kinetochore proteins with a CLK-like kinase domain, KKT10 and KKT19, which localize at kinetochores in metaphase but disappear at the onset of anaphase. We found that these proteins are functionally redundant. Double knockdown of KKT10 and KKT19 led to a significant delay in the metaphase to anaphase transition. We also found that phosphorylation of two kinetochore proteins, KKT4 and KKT7, depended on KKT10 and KKT19 in vivo. Finally, we showed that the N-terminal part of KKT7 directly interacts with KKT10 and that kinetochore localization of KKT10 depends not only on KKT7 but also on the KKT8 complex. Our results reveal that kinetochore localization of KKT10 and KKT19 is tightly controlled to regulate the metaphase to anaphase transition in T. brucei. This article has an associated First Person interview with the first author of the paper. Full Article
sea STIM1 interacts with termini of Orai channels in a sequential manner [RESEARCH ARTICLE] By jcs.biologists.org Published On :: 2020-04-29T03:28:24-07:00 Liling Niu, Fuyun Wu, Kaili Li, Jing Li, Shenyuan L. Zhang, Junjie Hu, and Qian Wang Store-operated Ca2+ entry (SOCE) is critical for numerous Ca2+-related processes. The activation of SOCE requires engagement between stromal interaction molecule 1 (STIM1) molecules on the endoplasmic reticulum and Ca2+ release-activated channel (CRAC) Orai on the plasma membrane. However, the molecular details of their interactions remain elusive. Here, we analyzed STIM1-Orai interactions using synthetic peptides derived from the N- and C-termini of Orai channels (Orai-NT and Orai-CT, respectively) and purified fragments of STIM1. The binding of STIM1 to Orai-NT is hydrophilic based, whereas binding to the Orai-CT is mostly hydrophobic. STIM1 decreases its affinity for Orai-CT when Orai-NT is present, supporting a stepwise interaction. Orai3-CT exhibits stronger binding to STIM1 than Orai1-CT, largely due to the shortness of one helical turn. The role of newly identified residues was confirmed by co-immunoprecipitation and Ca2+ imaging using full-length molecules. Our results provide important insight into CRAC gating by STIM1. Full Article
sea FAK regulates actin polymerization during sperm capacitation via the ERK2/GEF-H1/RhoA signaling pathway [RESEARCH ARTICLE] By jcs.biologists.org Published On :: 2020-04-28T08:24:46-07:00 Monica L. Salgado-Lucio, Danelia Ramirez-Ramirez, Coral Y. Jorge-Cruz, Ana L. Roa-Espitia, and Enrique O. Hernandez-Gonzalez Actin polymerization is a crucial process during sperm capacitation. We have recently described the participation of FAK during actin polymerization in guinea pig spermatozoa. However, the mechanism by which FAK mediates these processes is unknown. Our previous data have shown that MAPK1 (hereafter referred to as ERK2) is activated during the first minutes of capacitation, and inhibition of ERK2 blocked actin polymerization and the acrosome reaction. In this current study, we found that FAK is involved in ERK2 activation – as FAK was phosphorylated at tyrosine residue 925 and bound to Grb2 – and that inhibition of FAK results in a significant decrease of ERK2 activation. We also confirmed the presence of Rho guanine nucleotide exchange factor 2 (ARHGEF2, hereafter referred to as GEF-H1), which is able to associate with RhoA during capacitation. RhoA activation and its participation in actin polymerization were also analyzed. Inhibition of FAK or ERK1/2 impeded GEF-H1 phosphorylation, RhoA activation, and the association between GEF-H1 and RhoA. Finally, we observed the presence of fibronectin on the sperm surface, its role in sperm–sperm interaction as well as participation of β-integrin in the activation of ERK2. Our results show that the signaling pathway downstream of fibronectin, via integrin, FAK, Grb2, MEK1/2, ERK2, GEF-H1 and RhoA regulates the actin polymerization associated with spermatozoa capacitation. Full Article
sea Plakophilin 3 phosphorylation by ribosomal S6 kinases supports desmosome assembly [RESEARCH ARTICLE] By jcs.biologists.org Published On :: 2020-04-16T04:24:24-07:00 Lisa Müller, Katrin Rietscher, Rene Keil, Marvin Neuholz, and Mechthild Hatzfeld Desmosome remodeling is crucial for epidermal regeneration, differentiation and wound healing. It is mediated by adapting the composition, and by post-translational modifications, of constituent proteins. We have previously demonstrated in mouse suprabasal keratinocytes that plakophilin (PKP) 1 mediates strong adhesion, which is negatively regulated by insulin-like growth factor 1 (IGF1) signaling. The importance of PKP3 for epidermal adhesion is incompletely understood. Here, we identify a major role of epidermal growth factor (EGF), but not IGF1, signaling in PKP3 recruitment to the plasma membrane to facilitate desmosome assembly. We find that ribosomal S6 kinases (RSKs) associate with and phosphorylate PKP3, which promotes PKP3 association with desmosomes downstream of the EGF receptor. Knockdown of RSKs as well as mutation of an RSK phosphorylation site in PKP3 interfered with desmosome formation, maturation and adhesion. Our findings implicate a coordinate action of distinct growth factors in the control of adhesive properties of desmosomes through modulation of PKPs in a context-dependent manner. Full Article
sea Regenerative responses following DNA damage - {beta}-catenin mediates head regrowth in the planarian Schmidtea mediterranea [RESEARCH ARTICLE] By jcs.biologists.org Published On :: 2020-04-24T07:56:32-07:00 Annelies Wouters, Jan-Pieter Ploem, Sabine A. S. Langie, Tom Artois, Aziz Aboobaker, and Karen Smeets Pluripotent stem cells hold great potential for regenerative medicine. Increased replication and division, such is the case during regeneration, concomitantly increases the risk of adverse outcomes through the acquisition of mutations. Seeking for driving mechanisms of such outcomes, we challenged a pluripotent stem cell system during the tightly controlled regeneration process in the planarian Schmidtea mediterranea. Exposure to the genotoxic compound methyl methanesulfonate (MMS) revealed that despite a similar DNA-damaging effect along the anteroposterior axis of intact animals, responses differed between anterior and posterior fragments after amputation. Stem cell proliferation and differentiation proceeded successfully in the amputated heads, leading to regeneration of missing tissues. Stem cells in the amputated tails showed decreased proliferation and differentiation capacity. As a result, tails could not regenerate. Interference with the body-axis-associated component β-catenin-1 increased regenerative success in tail fragments by stimulating proliferation at an early time point. Our results suggest that differences in the Wnt signalling gradient along the body axis modulate stem cell responses to MMS. Full Article
sea Delineating the role of membrane blebs in a hybrid mode of cancer cell invasion in three-dimensional environments [RESEARCH ARTICLE] By jcs.biologists.org Published On :: 2020-04-28T08:24:46-07:00 Asja Guzman, Rachel C. Avard, Alexander J. Devanny, Oh Sang Kweon, and Laura J. Kaufman The study of cancer cell invasion in 3D environments in vitro has revealed a variety of invasive modes, including amoeboid migration, characterized by primarily round cells that invade in a protease- and adhesion-independent manner. Here, we delineate a contractility-dependent migratory mode of primarily round breast cancer cells that is associated with extensive integrin-mediated extracellular matrix (ECM) reorganization that occurs at membrane blebs, with bleb necks sites of integrin clustering and integrin-dependent ECM alignment. We show that the spatiotemporal distribution of blebs and their utilization for ECM reorganization is mediated by functional β1 integrin receptors and other components of focal adhesions. Taken together, the work presented here characterizes a migratory mode of primarily round cancer cells in complex 3D environments and reveals a fundamentally new function for membrane blebs in cancer cell invasion. Full Article
sea Dynein-mediated microtubule translocation powering neurite outgrowth in chick and Aplysia neurons requires microtubule assembly [RESEARCH ARTICLE] By jcs.biologists.org Published On :: 2020-04-24T07:56:32-07:00 Kristi McElmurry, Jessica E. Stone, Donghan Ma, Phillip Lamoureux, Yueyun Zhang, Michelle Steidemann, Lucas Fix, Fang Huang, Kyle E. Miller, and Daniel M. Suter Previously, we have shown that bulk microtubule (MT) movement correlates with neurite elongation, and blocking either dynein activity or MT assembly inhibits both processes. However, whether the contributions of MT dynamics and dynein activity to neurite elongation are separate or interdependent is unclear. Here, we investigated the underlying mechanism by testing the roles of dynein and MT assembly in neurite elongation of Aplysia and chick neurites using time-lapse imaging, fluorescent speckle microscopy, super-resolution imaging and biophysical analysis. Pharmacologically inhibiting either dynein activity or MT assembly reduced neurite elongation rates as well as bulk and individual MT anterograde translocation. Simultaneously suppressing both processes did not have additive effects, suggesting a shared mechanism of action. Single-molecule switching nanoscopy revealed that inhibition of MT assembly decreased the association of dynein with MTs. Finally, inhibiting MT assembly prevented the rise in tension induced by dynein inhibition. Taken together, our results suggest that MT assembly is required for dynein-driven MT translocation and neurite outgrowth. Full Article
sea Monocarboxylate Transporters (SLC16): Function, Regulation, and Role in Health and Disease [Review Articles] By pharmrev.aspetjournals.org Published On :: 2020-03-06T10:34:34-08:00 The solute carrier family 16 (SLC16) is comprised of 14 members of the monocarboxylate transporter (MCT) family that play an essential role in the transport of important cell nutrients and for cellular metabolism and pH regulation. MCTs 1–4 have been extensively studied and are involved in the proton-dependent transport of L-lactate, pyruvate, short-chain fatty acids, and monocarboxylate drugs in a wide variety of tissues. MCTs 1 and 4 are overexpressed in a number of cancers, and current investigations have focused on transporter inhibition as a novel therapeutic strategy in cancers. MCT1 has also been used in strategies aimed at enhancing drug absorption due to its high expression in the intestine. Other MCT isoforms are less well characterized, but ongoing studies indicate that MCT6 transports xenobiotics such as bumetanide, nateglinide, and probenecid, whereas MCT7 has been characterized as a transporter of ketone bodies. MCT8 and MCT10 transport thyroid hormones, and recently, MCT9 has been characterized as a carnitine efflux transporter and MCT12 as a creatine transporter. Expressed at the blood brain barrier, MCT8 mutations have been associated with an X-linked intellectual disability, known as Allan-Herndon-Dudley syndrome. Many MCT isoforms are associated with hormone, lipid, and glucose homeostasis, and recent research has focused on their potential roles in disease, with MCTs representing promising novel therapeutic targets. This review will provide a summary of the current literature focusing on the characterization, function, and regulation of the MCT family isoforms and on their roles in drug disposition and in health and disease. Significance Statement The 14-member solute carrier family 16 of monocarboxylate transporters (MCTs) plays a fundamental role in maintaining intracellular concentrations of a broad range of important endogenous molecules in health and disease. MCTs 1, 2, and 4 (L-lactate transporters) are overexpressed in cancers and represent a novel therapeutic target in cancer. Recent studies have highlighted the importance of MCTs in glucose, lipid, and hormone homeostasis, including MCT8 in thyroid hormone brain uptake, MCT12 in carnitine transport, and MCT11 in type 2 diabetes. Full Article
sea The rRNA m6A methyltransferase METTL5 is involved in pluripotency and developmental programs [Research Papers] By genesdev.cshlp.org Published On :: 2020-05-01T06:30:22-07:00 Covalent chemical modifications of cellular RNAs directly impact all biological processes. However, our mechanistic understanding of the enzymes catalyzing these modifications, their substrates and biological functions, remains vague. Amongst RNA modifications N6-methyladenosine (m6A) is widespread and found in messenger (mRNA), ribosomal (rRNA), and noncoding RNAs. Here, we undertook a systematic screen to uncover new RNA methyltransferases. We demonstrate that the methyltransferase-like 5 (METTL5) protein catalyzes m6A in 18S rRNA at position A1832. We report that absence of Mettl5 in mouse embryonic stem cells (mESCs) results in a decrease in global translation rate, spontaneous loss of pluripotency, and compromised differentiation potential. METTL5-deficient mice are born at non-Mendelian rates and develop morphological and behavioral abnormalities. Importantly, mice lacking METTL5 recapitulate symptoms of patients with DNA variants in METTL5, thereby providing a new mouse disease model. Overall, our biochemical, molecular, and in vivo characterization highlights the importance of m6A in rRNA in stemness, differentiation, development, and diseases. Full Article
sea Drosophila estrogen-related receptor directs a transcriptional switch that supports adult glycolysis and lipogenesis [Research Papers] By genesdev.cshlp.org Published On :: 2020-05-01T06:30:22-07:00 Metabolism and development must be closely coupled to meet the changing physiological needs of each stage in the life cycle. The molecular mechanisms that link these pathways, however, remain poorly understood. Here we show that the Drosophila estrogen-related receptor (dERR) directs a transcriptional switch in mid-pupae that promotes glucose oxidation and lipogenesis in young adults. dERR mutant adults are viable but display reduced locomotor activity, susceptibility to starvation, elevated glucose, and an almost complete lack of stored triglycerides. Molecular profiling by RNA-seq, ChIP-seq, and metabolomics revealed that glycolytic and pentose phosphate pathway genes are induced by dERR, and their reduced expression in mutants is accompanied by elevated glycolytic intermediates, reduced TCA cycle intermediates, and reduced levels of long chain fatty acids. Unexpectedly, we found that the central pathways of energy metabolism, including glycolysis, the tricarboxylic acid cycle, and electron transport chain, are coordinately induced at the transcriptional level in mid-pupae and maintained into adulthood, and this response is partially dependent on dERR, leading to the metabolic defects observed in mutants. Our data support the model that dERR contributes to a transcriptional switch during pupal development that establishes the metabolic state of the adult fly. Full Article
sea Autophagy promotes mammalian survival by suppressing oxidative stress and p53 [Research Papers] By genesdev.cshlp.org Published On :: 2020-05-01T06:30:22-07:00 Autophagy captures intracellular components and delivers them to lysosomes for degradation and recycling. Conditional autophagy deficiency in adult mice causes liver damage, shortens life span to 3 mo due to neurodegeneration, and is lethal upon fasting. As autophagy deficiency causes p53 induction and cell death in neurons, we sought to test whether p53 mediates the lethal consequences of autophagy deficiency. Here, we conditionally deleted Trp53 (p53 hereafter) and/or the essential autophagy gene Atg7 throughout adult mice. Compared with Atg7/ mice, the life span of Atg7/p53/ mice was extended due to delayed neurodegeneration and resistance to death upon fasting. Atg7 also suppressed apoptosis induced by p53 activator Nutlin-3, suggesting that autophagy inhibited p53 activation. To test whether increased oxidative stress in Atg7/ mice was responsible for p53 activation, Atg7 was deleted in the presence or absence of the master regulator of antioxidant defense nuclear factor erythroid 2-related factor 2 (Nrf2). Nrf2–/–Atg7/ mice died rapidly due to small intestine damage, which was not rescued by p53 codeletion. Thus, Atg7 limits p53 activation and p53-mediated neurodegeneration. In turn, NRF2 mitigates lethal intestine degeneration upon autophagy loss. These findings illustrate the tissue-specific roles for autophagy and functional dependencies on the p53 and NRF2 stress response mechanisms. Full Article
sea Embryo integrity regulates maternal proteostasis and stress resilience [Research Papers] By genesdev.cshlp.org Published On :: 2020-05-01T06:30:22-07:00 The proteostasis network is regulated by transcellular communication to promote health and fitness in metazoans. In Caenorhabditis elegans, signals from the germline initiate the decline of proteostasis and repression of cell stress responses at reproductive maturity, indicating that commitment to reproduction is detrimental to somatic health. Here we show that proteostasis and stress resilience are also regulated by embryo-to-mother communication in reproductive adults. To identify genes that act directly in the reproductive system to regulate somatic proteostasis, we performed a tissue targeted genetic screen for germline modifiers of polyglutamine aggregation in muscle cells. We found that inhibiting the formation of the extracellular vitelline layer of the fertilized embryo inside the uterus suppresses aggregation, improves stress resilience in an HSF-1-dependent manner, and restores the heat-shock response in the somatic tissues of the parent. This pathway relies on DAF-16/FOXO activation in vulval tissues to maintain stress resilience in the mother, suggesting that the integrity of the embryo is monitored by the vulva to detect damage and initiate an organismal protective response. Our findings reveal a previously undescribed transcellular pathway that links the integrity of the developing progeny to proteostasis regulation in the parent. Full Article
sea Developmental regulation of cell type-specific transcription by novel promoter-proximal sequence elements [Research Papers] By genesdev.cshlp.org Published On :: 2020-05-01T06:30:22-07:00 Cell type-specific transcriptional programs that drive differentiation of specialized cell types are key players in development and tissue regeneration. One of the most dramatic changes in the transcription program in Drosophila occurs with the transition from proliferating spermatogonia to differentiating spermatocytes, with >3000 genes either newly expressed or expressed from new alternative promoters in spermatocytes. Here we show that opening of these promoters from their closed state in precursor cells requires function of the spermatocyte-specific tMAC complex, localized at the promoters. The spermatocyte-specific promoters lack the previously identified canonical core promoter elements except for the Inr. Instead, these promoters are enriched for the binding site for the TALE-class homeodomain transcription factors Achi/Vis and for a motif originally identified under tMAC ChIP-seq peaks. The tMAC motif resembles part of the previously identified 14-bp β2UE1 element critical for spermatocyte-specific expression. Analysis of downstream sequences relative to transcription start site usage suggested that ACA and CNAAATT motifs at specific positions can help promote efficient transcription initiation. Our results reveal how promoter-proximal sequence elements that recruit and are acted upon by cell type-specific chromatin binding complexes help establish a robust, cell type-specific transcription program for terminal differentiation. Full Article
sea Telomere length heterogeneity in ALT cells is maintained by PML-dependent localization of the BTR complex to telomeres [Research Papers] By genesdev.cshlp.org Published On :: 2020-05-01T06:30:22-07:00 Telomeres consist of TTAGGG repeats bound by protein complexes that serve to protect the natural end of linear chromosomes. Most cells maintain telomere repeat lengths by using the enzyme telomerase, although there are some cancer cells that use a telomerase-independent mechanism of telomere extension, termed alternative lengthening of telomeres (ALT). Cells that use ALT are characterized, in part, by the presence of specialized PML nuclear bodies called ALT-associated PML bodies (APBs). APBs localize to and cluster telomeric ends together with telomeric and DNA damage factors, which led to the proposal that these bodies act as a platform on which ALT can occur. However, the necessity of APBs and their function in the ALT pathway has remained unclear. Here, we used CRISPR/Cas9 to delete PML and APB components from ALT-positive cells to cleanly define the function of APBs in ALT. We found that PML is required for the ALT mechanism, and that this necessity stems from APBs’ role in localizing the BLM–TOP3A–RMI (BTR) complex to ALT telomere ends. Strikingly, recruitment of the BTR complex to telomeres in a PML-independent manner bypasses the need for PML in the ALT pathway, suggesting that BTR localization to telomeres is sufficient to sustain ALT activity. Full Article
sea Targeted chemotherapy overcomes drug resistance in melanoma [Research Papers] By genesdev.cshlp.org Published On :: 2020-05-01T06:30:22-07:00 The emergence of drug resistance is a major obstacle for the success of targeted therapy in melanoma. Additionally, conventional chemotherapy has not been effective as drug-resistant cells escape lethal DNA damage effects by inducing growth arrest commonly referred to as cellular dormancy. We present a therapeutic strategy termed "targeted chemotherapy" by depleting protein phosphatase 2A (PP2A) or its inhibition using a small molecule inhibitor (1,10-phenanthroline-5,6-dione [phendione]) in drug-resistant melanoma. Targeted chemotherapy induces the DNA damage response without causing DNA breaks or allowing cellular dormancy. Phendione treatment reduces tumor growth of BRAFV600E-driven melanoma patient-derived xenografts (PDX) and diminishes growth of NRASQ61R-driven melanoma, a cancer with no effective therapy. Remarkably, phendione treatment inhibits the acquisition of resistance to BRAF inhibition in BRAFV600E PDX highlighting its effectiveness in combating the advent of drug resistance. Full Article
sea Positive autofeedback regulation of Ptf1a transcription generates the levels of PTF1A required to generate itch circuit neurons [Research Papers] By genesdev.cshlp.org Published On :: 2020-05-01T06:30:22-07:00 Peripheral somatosensory input is modulated in the dorsal spinal cord by a network of excitatory and inhibitory interneurons. PTF1A is a transcription factor essential in dorsal neural tube progenitors for specification of these inhibitory neurons. Thus, mechanisms regulating Ptf1a expression are key for generating neuronal circuits underlying somatosensory behaviors. Mutations targeted to distinct cis-regulatory elements for Ptf1a in mice, tested the in vivo contribution of each element individually and in combination. Mutations in an autoregulatory enhancer resulted in reduced levels of PTF1A, and reduced numbers of specific dorsal spinal cord inhibitory neurons, particularly those expressing Pdyn and Gal. Although these mutants survive postnatally, at ~3–5 wk they elicit a severe scratching phenotype. Behaviorally, the mutants have increased sensitivity to itch, but acute sensitivity to other sensory stimuli such as mechanical or thermal pain is unaffected. We demonstrate a requirement for positive transcriptional autoregulatory feedback to attain the level of the neuronal specification factor PTF1A necessary for generating correctly balanced neuronal circuits. Full Article
sea Prognostic impact of pre-existing interstitial lung disease in non-HIV patients with Pneumocystis pneumonia By openres.ersjournals.com Published On :: 2020-05-04T00:29:32-07:00 Background The increasing incidence of life-threatening Pneumocystis pneumonia (PCP) in non-HIV immunocompromised patients is a global concern. Yet, no reports have examined the prognostic significance of pre-existing interstitial lung disease (ILD) in non-HIV PCP. Methods We retrospectively reviewed the medical records of non-HIV PCP patients with (ILD group) or without (non-ILD group) pre-existing ILD. The clinical features and outcomes of the ILD group were compared with those of the non-ILD group. Cox regression models were constructed to identify prognostic factors. Results 74 patients were enrolled in this study. The 90-day mortality was significantly higher in the ILD group than in the non-ILD group (62.5% versus 19.0%, p<0.001). In the ILD group, patients with a higher percentage of bronchoalveolar lavage fluid neutrophils had worse outcomes compared to those having a lower percentage (p=0.026). Multivariate analyses revealed that pre-existing ILD (p=0.002) and low levels of serum albumin (p=0.009) were independent risk factors for 90-day mortality. Serum levels of β-d-glucan were significantly reduced after treatment of PCP in both groups, whereas levels of Krebs von den Lungen-6 (KL-6) significantly increased in the ILD group. In the ILD group, the 90-day mortality of patients with increasing KL-6 levels after treatment was significantly higher than those with decreasing levels (78.9% versus 0%, p=0.019). Conclusion In non-HIV PCP patients, pre-existing ILD is associated with a poorer prognosis. Prophylaxis for PCP is needed in patients with pre-existing ILD under immunosuppression. Full Article
sea Detecting and Monitoring Porcine Hemagglutinating Encephalomyelitis Virus, an Underresearched Betacoronavirus By msphere.asm.org Published On :: 2020-05-06T07:29:31-07:00 ABSTRACT Members of family Coronaviridae cause a variety of diseases in birds and mammals. Porcine hemagglutinating encephalomyelitis virus (PHEV), a lesser-researched coronavirus, can infect naive pigs of any age, but clinical disease is observed in pigs ≤4 weeks of age. No commercial PHEV vaccines are available, and neonatal protection from PHEV-associated disease is presumably dependent on lactogenic immunity. Although subclinical PHEV infections are thought to be common, PHEV ecology in commercial swine herds is unknown. To begin to address this gap in knowledge, a serum IgG antibody enzyme-linked immunosorbent assay (ELISA) based on the S1 protein was developed and evaluated on known-status samples and then used to estimate PHEV seroprevalence in U.S. sow herds. Assessment of the diagnostic performance of the PHEV S1 ELISA using serum samples (n = 924) collected from 7-week-old pigs (n = 84; 12 pigs per group) inoculated with PHEV, porcine epidemic diarrhea virus, transmissible gastroenteritis virus, porcine respiratory coronavirus, or porcine deltacoronavirus showed that a sample-to-positive cutoff value of ≥0.6 was both sensitive and specific, i.e., all PHEV-inoculated pigs were seropositive from days postinoculation 10 to 42, and no cross-reactivity was observed in samples from other groups. The PHEV S1 ELISA was then used to estimate PHEV seroprevalence in U.S. sow herds (19 states) using 2,756 serum samples from breeding females (>28 weeks old) on commercial farms (n = 104) with no history of PHEV-associated disease. The overall seroprevalence was 53.35% (confidence interval [CI], ±1.86%) and herd seroprevalence was 96.15% (CI, ±3.70%). IMPORTANCE There is a paucity of information concerning the ecology of porcine hemagglutinating encephalomyelitis virus (PHEV) in commercial swine herds. This study provided evidence that PHEV infection is endemic and highly prevalent in U.S. swine herds. These results raised questions for future studies regarding the impact of endemic PHEV on swine health and the mechanisms by which this virus circulates in endemically infected populations. Regardless, the availability of the validated PHEV S1 enzyme-linked immunosorbent assay (ELISA) provides the means for swine producers to detect and monitor PHEV infections, confirm prior exposure to the virus, and to evaluate the immune status of breeding herds. Full Article
sea An Extensive Meta-Metagenomic Search Identifies SARS-CoV-2-Homologous Sequences in Pangolin Lung Viromes By msphere.asm.org Published On :: 2020-05-06T07:29:31-07:00 ABSTRACT In numerous instances, tracking the biological significance of a nucleic acid sequence can be augmented through the identification of environmental niches in which the sequence of interest is present. Many metagenomic data sets are now available, with deep sequencing of samples from diverse biological niches. While any individual metagenomic data set can be readily queried using web-based tools, meta-searches through all such data sets are less accessible. In this brief communication, we demonstrate such a meta-metagenomic approach, examining close matches to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in all high-throughput sequencing data sets in the NCBI Sequence Read Archive accessible with the "virome" keyword. In addition to the homology to bat coronaviruses observed in descriptions of the SARS-CoV-2 sequence (F. Wu, S. Zhao, B. Yu, Y. M. Chen, et al., Nature 579:265–269, 2020, https://doi.org/10.1038/s41586-020-2008-3; P. Zhou, X. L. Yang, X. G. Wang, B. Hu, et al., Nature 579:270–273, 2020, https://doi.org/10.1038/s41586-020-2012-7), we note a strong homology to numerous sequence reads in metavirome data sets generated from the lungs of deceased pangolins reported by Liu et al. (P. Liu, W. Chen, and J. P. Chen, Viruses 11:979, 2019, https://doi.org/10.3390/v11110979). While analysis of these reads indicates the presence of a similar viral sequence in pangolin lung, the similarity is not sufficient to either confirm or rule out a role for pangolins as an intermediate host in the recent emergence of SARS-CoV-2. In addition to the implications for SARS-CoV-2 emergence, this study illustrates the utility and limitations of meta-metagenomic search tools in effective and rapid characterization of potentially significant nucleic acid sequences. IMPORTANCE Meta-metagenomic searches allow for high-speed, low-cost identification of potentially significant biological niches for sequences of interest. Full Article
sea Microbiota-Propelled T Helper 17 Cells in Inflammatory Diseases and Cancer [Review] By mmbr.asm.org Published On :: 2020-03-04T05:30:12-08:00 Technologies allowing genetic sequencing of the human microbiome are opening new realms to discovery. The host microbiota substantially impacts immune responses both in immune-mediated inflammatory diseases (IMIDs) and in tumors affecting tissues beyond skin and mucosae. However, a mechanistic link between host microbiota and cancer or IMIDs has not been well established. Here, we propose T helper 17 (TH17) lymphocytes as the connecting factor between host microbiota and rheumatoid or psoriatic arthritides, multiple sclerosis, breast or ovarian cancer, and multiple myeloma. We theorize that similar mechanisms favor the expansion of gut-borne TH17 cells and their deployment at the site of inflammation in extraborder IMIDs and tumors, where TH17 cells are driving forces. Thus, from a pathogenic standpoint, tumors may share mechanistic routes with IMIDs. A review of similarities and divergences in microbiota-TH17 cell interactions in IMIDs and cancer sheds light on previously ignored pathways in either one of the two groups of pathologies and identifies novel therapeutic avenues. Full Article
sea Chitotriosidase: a marker and modulator of lung disease By err.ersjournals.com Published On :: 2020-04-29T01:39:43-07:00 Chitotriosidase (CHIT1) is a highly conserved and regulated chitinase secreted by activated macrophages; it is a member of the 18-glycosylase family (GH18). CHIT1 is the most prominent chitinase in humans, can cleave chitin and participates in the body's immune response and is associated with inflammation, infection, tissue damage and remodelling processes. Recently, CHIT1 has been reported to be involved in the molecular pathogenesis of pulmonary fibrosis, bronchial asthma, COPD and pulmonary infections, shedding new light on the role of these proteins in lung pathophysiology. The potential roles of CHIT1 in lung diseases are reviewed in this article. Full Article
sea Thoracic ultrasound in the modern management of pleural disease By err.ersjournals.com Published On :: 2020-04-29T01:39:43-07:00 Physician-led thoracic ultrasound (TUS) has substantially changed how respiratory disorders, and in particular pleural diseases, are managed. The use of TUS as a point-of-care test enables the respiratory physician to quickly and accurately diagnose pleural pathology and ensure safe access to the pleural space during thoracentesis or chest drain insertion. Competence in performing TUS is now an obligatory part of respiratory speciality training programmes in different parts of the world. Pleural physicians with higher levels of competence routinely use TUS during the planning and execution of more sophisticated diagnostic and therapeutic interventions, such as core needle pleural biopsies, image-guided drain insertion and medical thoracoscopy. Current research is gauging the potential of TUS in predicting the outcome of different pleural interventions and how it can aid in tailoring the optimum treatment according to different TUS-based parameters. Full Article
sea Modern deep-water agglutinated foraminifera from IODP Expedition 323, Bering Sea: ecological and taxonomic implications By jm.lyellcollection.org Published On :: 2017-08-10T08:29:35-07:00 Despite the importance of the Bering Sea for subarctic oceanography and climate, relatively little is known of the foraminifera from the extensive Aleutian Basin. We report the occurrence of modern deep-water agglutinated foraminifera collected at seven sites cored during Integrated Ocean Drilling Program (IODP) Expedition 323 in the Bering Sea. Assemblages collected from core-top samples contained 32 genera and 50 species and are described and illustrated here for the first time. Commonly occurring species include typical deep-water Rhizammina, Reophax, Rhabdammina, Recurvoides and Nodulina. Assemblages from the northern sites also consist of accessory Cyclammina, Eggerelloides and Glaphyrammina, whilst those of the Bowers Ridge sites consist of other tubular genera and Martinottiella. Of the studied stations with the lowest dissolved oxygen concentrations, the potentially Bering Sea endemic Eggerelloides sp. 1 inhabits the northern slope, which has the highest primary productivity, and the potentially endemic Martinottiella sp. 3 inhabits Bowers Ridge, which has the lowest oxygen concentrations but relatively low annual productivity. Martinottiella sp. 3, with open pores on its test surface, has previously been reported in Pliocene to Recent material from Bowers Ridge. Despite relatively small sample sizes, ecological constraints may imply that the Bering Sea experienced high productivity and reduced oxygen at times since at least the Pliocene. We note the partially endemic nature of the agglutinated foraminiferal assemblages, which may at least in part be due to basin restriction, the geologically long time period of reduced oxygen, and high organic carbon flux. Our results indicate the importance of gathering further surface sample data from the Aleutian Basin. Full Article
sea Underweight Increases the Risk of End-Stage Renal Diseases for Type 2 Diabetes in Korean Population: Data From the National Health Insurance Service Health Checkups 2009-2017 By care.diabetesjournals.org Published On :: 2020-04-20T12:00:33-07:00 OBJECTIVE There is a controversy over the association between obesity and end-stage renal disease (ESRD) in people with or without type 2 diabetes; therefore, we examined the effect of BMI on the risk of ESRD according to glycemic status in the Korean population. RESEARCH DESIGN AND METHODS The study monitored 9,969,848 participants who underwent a National Health Insurance Service health checkup in 2009 from baseline to the date of diagnosis of ESRD during a follow-up period of ~8.2 years. Obesity was categorized by World Health Organization recommendations for Asian populations, and glycemic status was categorized into the following five groups: normal, impaired fasting glucose (IFG), newly diagnosed diabetes, diabetes <5 years, and diabetes ≥5 years. RESULTS Underweight was associated with a higher risk of ESRD in all participants after adjustment for all covariates. In the groups with IFG, newly diagnosed type 2 diabetes, diabetes duration <5 years, and diabetes ≥5 years, the hazard ratio (HR) of the underweight group increased with worsening glycemic status (HR 1.431 for IFG, 2.114 for newly diagnosed diabetes, 4.351 for diabetes <5 years, and 6.397 for diabetes ≥5 years), using normal weight with normal fasting glucose as a reference. The adjusted HRs for ESRD were also the highest in the sustained underweight group regardless of the presence of type 2 diabetes (HR 1.606 for nondiabetes and 2.14 for diabetes). CONCLUSIONS Underweight showed more increased HR of ESRD according to glycemic status and diabetes duration in the Korean population. These associations also persisted in the group with sustained BMI during the study period. Full Article
sea The Prognosis of Patients With Type 2 Diabetes and Nonalbuminuric Diabetic Kidney Disease Is Not Always Poor: Implication of the Effects of Coexisting Macrovascular Complications (JDDM 54) By care.diabetesjournals.org Published On :: 2020-04-20T12:00:33-07:00 OBJECTIVE Nonalbuminuric diabetic kidney disease (DKD) has become the prevailing phenotype in patients with type 2 diabetes. However, it remains unclear whether its prognosis is poorer than that of other DKD phenotypes. RESEARCH DESIGN AND METHODS A total of 2,953 Japanese patients with type 2 diabetes and estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m2, enrolled in an observational cohort study in 2004, were followed until 2015. On the basis of albuminuria (>30 mg/g creatinine) and reduced eGFR (<60 mL/min/1.73 m2) at baseline, participants were classified into the four DKD phenotypes—no-DKD, albuminuric DKD without reduced eGFR, nonalbuminuric DKD with reduced eGFR, and albuminuric DKD with reduced eGFR—to assess the risks of mortality, cardiovascular disease (CVD), and renal function decline. RESULTS During the mean follow-up of 9.7 years, 113 patients died and 263 developed CVD. In nonalbuminuric DKD, the risks of death or CVD were not higher than those in no-DKD (adjusted hazard ratio 1.02 [95% CI 0.66, 1.60]) and the annual decline in eGFR was slower than in other DKD phenotypes. The risks of death or CVD in nonalbuminuric DKD without prior CVD were similar to those in no-DKD without prior CVD, whereas the risks in nonalbuminuric DKD with prior CVD as well as other DKD phenotypes were higher. CONCLUSIONS Nonalbuminuric DKD did not have a higher risk of mortality, CVD events, or renal function decline than the other DKD phenotypes. In nonalbuminuric DKD, the presence of macrovascular complications may be a main determinant of prognosis rather than the renal phenotype. Full Article
sea Dalcetrapib Reduces Risk of New-Onset Diabetes in Patients With Coronary Heart Disease By care.diabetesjournals.org Published On :: 2020-04-20T12:00:33-07:00 OBJECTIVE Incident type 2 diabetes is common among patients with recent acute coronary syndrome and is associated with an adverse prognosis. Some data suggest that cholesteryl ester transfer protein (CETP) inhibitors reduce incident type 2 diabetes. We compared the effect of treatment with the CETP inhibitor dalcetrapib or placebo on incident diabetes in patients with recent acute coronary syndrome. RESEARCH DESIGN AND METHODS In the dal-OUTCOMES trial, 15,871 patients were randomly assigned to treatment with dalcetrapib 600 mg daily or placebo, beginning 4–12 weeks after an acute coronary syndrome. Absence of diabetes at baseline was based on medical history, no use of antihyperglycemic medication, and hemoglobin A1c and serum glucose levels below diagnostic thresholds. Among these patients, incident diabetes after randomization was defined by any diabetes-related adverse event, new use of antihyperglycemic medication, hemoglobin A1c ≥6.5%, or a combination of at least two measurements of serum glucose ≥7.0 mmol/L (fasting) or ≥11.1 mmol/L (random). RESULTS At baseline, 10,645 patients (67% of the trial cohort) did not have diabetes. During a median follow-up of 30 months, incident diabetes was identified in 403 of 5,326 patients (7.6%) assigned to dalcetrapib and in 516 of 5,319 (9.7%) assigned to placebo, corresponding to absolute risk reduction of 2.1%, hazard ratio of 0.77 (95% CI 0.68–0.88; P < 0.001), and a need to treat 40 patients for 3 years to prevent 1 incident case of diabetes. Considering only those with prediabetes at baseline, the number needed to treat for 3 years to prevent 1 incident case of diabetes was 25. Dalcetrapib also decreased the number of patients who progressed from normoglycemia to prediabetes and increased the number who regressed from diabetes to no diabetes. CONCLUSIONS In patients with a recent acute coronary syndrome, incident diabetes is common and is reduced substantially by treatment with dalcetrapib. Full Article
sea Every Fifth Individual With Type 1 Diabetes Suffers From an Additional Autoimmune Disease: A Finnish Nationwide Study By care.diabetesjournals.org Published On :: 2020-04-20T12:00:32-07:00 OBJECTIVE The aim of this study was to quantify the excess risk of autoimmune hypothyroidism and hyperthyroidism, Addison disease, celiac disease, and atrophic gastritis in adults with type 1 diabetes (T1D) compared with nondiabetic individuals in Finland. RESEARCH DESIGN AND METHODS The study included 4,758 individuals with T1D from the Finnish Diabetic Nephropathy (FinnDiane) Study and 12,710 nondiabetic control individuals. The autoimmune diseases (ADs) were identified by linking the data with the Finnish nationwide health registries from 1970 to 2015. RESULTS The median age of the FinnDiane individuals at the end of follow-up in 2015 was 51.4 (interquartile range 42.6–60.1) years, and the median duration of diabetes was 35.5 (26.5–44.0) years. Of individuals with T1D, 22.8% had at least one additional AD, which included 31.6% of women and 14.9% of men. The odds ratios for hypothyroidism, hyperthyroidism, celiac disease, Addison disease, and atrophic gastritis were 3.43 (95% CI 3.09–3.81), 2.98 (2.27–3.90), 4.64 (3.71–5.81), 24.13 (5.60–104.03), and 5.08 (3.15–8.18), respectively, in the individuals with T1D compared with the control individuals. The corresponding ORs for women compared with men were 2.96 (2.53–3.47), 2.83 (1.87–4.28), 1.52 (1.15–2.02), 2.22 (0.83–5.91), and 1.36 (0.77–2.39), respectively, in individuals with T1D. Late onset of T1D and aging increased the risk of hypothyroidism, whereas young age at onset of T1D increased the risk of celiac disease. CONCLUSIONS This is one of the largest studies quantifying the risk of coexisting AD in adult individuals with T1D in the country with the highest incidence of T1D in the world. The results highlight the importance of continuous screening for other ADs in individuals with T1D. Full Article
sea Incidence and Associations of Chronic Kidney Disease in Community Participants With Diabetes: A 5-Year Prospective Analysis of the EXTEND45 Study By care.diabetesjournals.org Published On :: 2020-04-20T12:00:32-07:00 OBJECTIVE To determine the incidence of and factors associated with an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 in people with diabetes. RESEARCH DESIGN AND METHODS We identified people with diabetes in the EXamining ouTcomEs in chroNic Disease in the 45 and Up Study (EXTEND45), a population-based cohort study (2006–2014) that linked the Sax Institute’s 45 and Up Study cohort to community laboratory and administrative data in New South Wales, Australia. The study outcome was the first eGFR measurement <60 mL/min/1.73 m2 recorded during the follow-up period. Participants with eGFR < 60 mL/min/1.73 m2 at baseline were excluded. We used Poisson regression to estimate the incidence of eGFR <60 mL/min/1.73 m2 and multivariable Cox regression to examine factors associated with the study outcome. RESULTS Of 9,313 participants with diabetes, 2,106 (22.6%) developed incident eGFR <60 mL/min/1.73 m2 over a median follow-up time of 5.7 years (interquartile range, 3.0–5.9 years). The eGFR <60 mL/min/1.73 m2 incidence rate per 100 person-years was 6.0 (95% CI 5.7–6.3) overall, 1.5 (1.3–1.9) in participants aged 45–54 years, 3.7 (3.4–4.0) for 55–64 year olds, 7.6 (7.1–8.1) for 65–74 year olds, 15.0 (13.0–16.0) for 75–84 year olds, and 26.0 (22.0–32.0) for those aged 85 years and over. In a fully adjusted multivariable model incidence was independently associated with age (hazard ratio 1.23 per 5-year increase; 95% CI 1.19–1.26), geography (outer regional and remote versus major city: 1.36; 1.17–1.58), obesity (obese class III versus normal: 1.44; 1.16–1.80), and the presence of hypertension (1.52; 1.33–1.73), coronary heart disease (1.13; 1.02–1.24), cancer (1.30; 1.14–1.50), and depression/anxiety (1.14; 1.01–1.27). CONCLUSIONS In participants with diabetes, the incidence of an eGFR <60 mL/min/1.73 m2 was high. Older age, remoteness of residence, and the presence of various comorbid conditions were associated with higher incidence. Full Article