bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bone morphogenetic protein 4 reduces global H3K4me3 to inhibit proliferation and promote differentiation of human neural stem cells
Authors: Nayak Sonali , Best Benjamin , Hayes Emily , Mahenthiran Ashorne , Wadhwani Nitin R , Mania-Farnell Barbara , Hashizume Rintaro , Kessler John A , James Charles David , Tomita Tadanori , Xi Guifa 
Published: January 2020

ABSTRACTPosttranslational modifications (PTMs) on histone tails spatiotemporally dictate mammalian neural stem cell (NSC) fate. Bone morphogenetic protein 4 (BMP4), a member of the transforming growth factor β (TGF-β) superfamily, suppresses NSC proliferation and fosters differentiation into astroglial cells. Whether PTMs mediate these effects of BMP4 is unknown. Here we demonstrate that BMP4 signaling causes a net reduction in cellular histone H3 lysine 4 trimethylation (H3K4me3), an active histone mark at promoters of genes associated with human NSC proliferation. We also show that H3K4me3 reduction by BMP4 is mediated by decreased expression of SETD1A and WDR82, two methyltransferase components of SETD1A-COMPASS. Down-regulation of these components decreases expression of key genes expressed in hNSCs, while ectopic expression via transfection dedifferentiates human astrocytes (HAs). These observations suggest that BMP4 influences NSC fate by regulating PTMs and altering chromatin structure.SIGNIFICANCE STATEMENTBMP4 is critical in determining hNSC fate. Whether histone posttranslational modifications (PTM) mediate the effects of BMP4 is unknown. Here we report that H3K4me3, brought about by its methyltransferases SETD1A and WDR82, at promoters of stem cell genes OCT4 and NESTIN is involved in human neural stem cell (hNSC) maintenance. BMP4 promotes hNSC astroglial differentiation in part through reduction of SETD1A and WDR82 and thus decreased frequency of H3K4me3 at the promoters of these genes. These results provide evidence that BMP4 promotes hNSC differentiation through a potential epigenetic mechanism and extend our understanding of the role of histone PTM in central nervous system development.
Membrane-associated α-tubulin is less acetylated in postmortem prefrontal cortex from depressed subjects relative to controls: cytoskeletal dynamics, HDAC6 and depression
Authors: Singh Harinder , Chmura Justyna , Bhaumik Runa , Pandey Ghanshyam N. , Rasenick Mark M. 
Published: January 2020

AbstractCytoskeletal proteins and post-translational modifications play a role in mood disorders. Post-translational modifications of tubulin also alter microtubule dynamics. Furthermore, tubulin interacts closely with Gαs, the G-protein responsible for activation of adenylyl cyclase. Postmortem tissue derived from depressed suicide brain showed increased Gαsin lipid-raft domains compared to normal subjects. Gαs, when ensconced in lipid-rafts, couples less effectively with adenylyl cyclase to produce cAMP and this is reversed by antidepressant treatment. A recentin-vitrostudy demonstrated that tubulin anchors Gαsto lipid-rafts and that increased tubulin acetylation (due to HDAC-6 inhibition) and antidepressant treatment decreased the proportion of Gαscomplexed with tubulin. This suggested that deacetylated-tubulin might be more prevalent in depression. This study, examined tubulin acetylation in whole tissue homogenate, plasma-membrane and lipid-raft membrane domains in tissue from normal control (NC) subjects, depressed suicides and depressed non-suicides. While tissue homogenate showed no changes in 〈-tubulin/tubulin acetylation between control, depressed suicides and depressed non-suicides, plasma-membrane associated tubulin showed significant decreases in acetylation in depressed suicides and depressed non-suicides compared to controls. No change was seen in expression of the enzymes responsible for tubulin acetylation or deacetylation. These data suggest that during depression, membrane localized tubulin maintains a lower acetylation state, permitting increased sequestration of Gαsin lipid-raft domains, where it is less likely to couple to adenylyl cyclase for cAMP production. Thus, membrane tubulin may play a role in mood disorders which could be exploited for diagnosis and treatment.Significance StatementThere is little understanding about the molecular mechanisms involved in the development of depression and in severe cases, suicide. Evidence for the role of microtubule modifications in progression of depressive disorders is emerging. These postmortem data provide strong evidence for membrane tubulin modification leading to reduced efficacy of the G protein, Gsα, in depression. This study reveals a direct link between decreased tubulin acetylation in human depression and the increased localization of Gαsin lipid-raft domains responsible for attenuated cAMP signaling. The evidence presented here suggest a novel diagnostic and therapeutic locus for depression.
Hierarchical transcriptional regulation of quorum-sensing genes inVibrio harveyi
Authors: Chaparian Ryan R. , Ball Alyssa , van Kessel Julia C. 
Published: January 2020

AbstractIn vibrios, quorum sensing controls hundreds of genes that are required for cell density-specific behaviors including bioluminescence, biofilm formation, competence, secretion, and swarming motility. The central transcription factor in the quorum-sensing pathway is LuxR/HapR, which directly regulates ∼100 genes in the >400-gene regulon ofVibrio harveyi. Among these directly controlled genes are 15 transcription factors, which we predicted would comprise the second tier in the hierarchy of the quorum-sensing regulon. We confirmed that LuxR binds to the promoters of these genesin vitroand quantified the extent of LuxR activation or repression of transcript levels. RNA-seq indicates that most of these transcriptional regulators control only a few genes, with the exception of MetJ, which is a global regulator. The genes regulated by these transcription factors are predicted to be involved in methionine and thiamine biosynthesis, membrane stability, RNA processing, c-di-GMP degradation, sugar transport, and other cellular processes. These data support a hierarchical model in which LuxR directly regulates 15 transcription factors that drive the second level of the gene expression cascade to influence cell density-dependent metabolic states and behaviors inV. harveyi.ImportanceQuorum sensing is important for survival of bacteria in nature and influences the actions of bacterial groups. In the relatively few studied examples of quorum sensing-controlled genes, these genes are associated with competition or cooperation in complex microbial communities and/or virulence in a host. However, quorum sensing in vibrios controls the expression of hundreds of genes, and their functions are mostly unknown or uncharacterized. In this study, we identify the regulators of the second-tier of gene expression in the quorum-sensing system of the aquatic pathogenVibrio harveyi.Our identification of regulatory networks and metabolic pathways controlled by quorum sensing can be extended and compared to otherVibriospecies to understand the physiology, ecology, and pathogenesis of these organisms.
The defining genomic and predicted metabolic features of the Acetobacterium genus
Authors: Ross Daniel E. , Marshall Christopher W. , Gulliver Djuna , May Harold D. , Norman R. Sean 
Published: January 2020

AbstractAcetogens are anaerobic bacteria capable of fixing CO2or CO to produce acetyl-CoA and ultimately acetate using the Wood-Ljungdahl pathway (WLP). This autotrophic metabolism plays a major role in the global carbon cycle.Acetobacterium woodii, which is a member of theEubacteriaceaefamily and type strain of theAcetobacteriumgenus, has been critical for understanding the biochemistry and energy conservation in acetogens. Other members of theAcetobacteriumgenus have been isolated from a variety of environments or have had genomes recovered from metagenome data, but no systematic investigation has been done into the unique and varying metabolisms of the genus. Using the 4 sequenced isolates and 5 metagenome-assembled genomes available, we sequenced the genomes of an additional 4 isolates (A. fimetarium, A. malicum, A. paludosum,andA. tundrae) and conducted a comparative genome analysis of 13 differentAcetobacteriumgenomes to obtain better phylogenomic resolution and understand the metabolic diversity of theAcetobacteriumgenus. Our findings suggest that outside of the reductive acetyl-CoA (Wood-Ljungdahl) pathway, theAcetobacteriumgenus is more phylogenetically and metabolically diverse than expected, with metabolism of fructose, lactate, and H2:CO2constant across the genus, and ethanol, methanol, caffeate, and 2,3-butanediol varying across the genus. While the gene arrangement and predicted proteins of the methyl (Cluster II) and carbonyl (Cluster III) branches of the Wood Ljungdahl pathway are highly conserved across all sequencedAcetobacteriumgenomes, Cluster 1, encoding the formate dehydrogenase, is not. Furthermore, the accessory WLP components, including the Rnf cluster and electron bifurcating hydrogenase, were also well conserved, though all but four strains encode for two Rnf clusters. Additionally, comparative genomics revealed clade-specific potential functional capabilities, such as amino acid transport and metabolism in the psychrophilic group, and biofilm formation in theA. wieringaeclade, which may afford these groups an advantage in low-temperature growth or attachment to solid surfaces, respectively. Overall, the data presented herein provides a framework for examining the ecology and evolution of theAcetobacteriumgenus and highlights the potential of these species as a source of fuels and chemicals from CO2-feedstocks.
Effects of methionine supplementing on intestine, liver and uterus morphology, and on positivity and expression of calbindin-D28k and TRPV6 calcium carriers in laying quails in thermoneutral conditions and under thermal stress
Authors: de Moraes Lanuza Ribeiro , Delicato Maria Eduarda Araújo , da Silva Cruz André , da Silva Hugo Thyares Fonseca Nascimento Per , de Vasconcelos Alves Clara Virgínia Batista , Campos Danila Barreiro , Saraiva Edilson Paes , da Costa Fernando Perazzo , Guerra Ricardo Romão 
Published: January 2020

AbstractThe aim of this study was to provide support for the performance, localization and expression of the epithelial calcium transporter channels, calbindin-D28k (Calb) and TRPV6, and of the morphology of the digestive and reproductive system of laying quails under heat stress, and with methionine supplementation. Therefore, the present study characterized the positivity (immunohistochemistry) and expression (real-time PCR) of calcium channels (Calb and TRPV6) in the kidneys, intestine and uterus of 504 laying quails that were submitted to different methionine supplementation (100, 110 and 120%) and temperatures (20, 24, 28 and 32°C). The animals under thermal stress had lower villus height, villus:crypt ratio, and goblet cell index in the duodenum and jejunum, fewer secondary and tertiary uterine folds, smaller hepatic steatosis, and increased number of distal convoluted renal tubules (CT) positive to Calb (protein), and increased positivity in proximal CTs. The deleterious effects of heat stress were minimized with methionine supplementation for the following variables: duodenal crypts, number of goblet cells of the jejunum, number of uterine folds, decreased Calb positivity in intestines and kidney, increased positivity of Calb in the uterus and increased TRPV6 gene expression in the kidney. Calcium transporters were altered due to less need for calcium absorption and reabsorption due to more calcium available with the supplementation, increasing egg production and quality. Methionine supplementation further increased intestinal villus absorption area and height, increased steatosis, decreased Calb positivity in the intestine and kidney, increased uterine positivity and Calb expression, and increased TRPV6 expression in the uterus under thermoneutrality. This is the first study that describes the gene and protein expression of calcium transporters in the intestine, kidney and uterus of laying quails, and concludes that the use of methionine supplementation is justifiable in order to partially reverse the deleterious effects of thermal stress on the production.
Mechanisms associated with pyrethroid resistance in populations ofAedes aegypti(Diptera: Culicidae) from the Caribbean coast of Colombia
Authors: Pareja-Loaiza Paula X. , Varon Liliana Santacoloma , Vega Gabriela Rey , Gómez-Camargo Doris , Maestre-Serrano Ronald , Lenhart Audrey 
Published: January 2020

AbstractAedes aegyptiis the main vector of dengue, chikungunya, and Zika viruses, which are of great public health importance in Colombia.Aedescontrol strategies in Colombia rely heavily on the use of organophosphate and pyrethroid insecticides, providing constant selection pressure and the emergence of resistant populations. In recent years, insecticide use has increased due to the increased incidence of dengue and recent introductions of chikungunya and Zika. In the present study, pyrethroid resistance was studied across six populations ofA. aegyptifrom the Caribbean coast of Colombia. Susceptibility to λ-cyhalothrin, deltamethrin, and permethrin was assessed, and resistance intensity was determined. Activity levels of enzymes associated with resistance were measured, and the frequencies of threekdralleles (V1016I, F1534C, V410L) were calculated. Results showed variations in pyrethroid susceptibility acrossA. aegyptipopulations and altered enzyme activity levels were detected. Thekdralleles were detected in all populations, with high variations in frequencies: V1016I (frequency ranging from 0.15–0.70), F1534C (range 0.94–1.00), and V410L (range 0.05–0.72). In assays of phenotyped individuals, associations were observed between the presence of V1016I, F1534C, and V410L alleles and resistance to the evaluated pyrethroids, as well as between the VI1016/CC1534/VL410tri-locus genotype and λ-cyhalothrin and permethrin resistance. The results of the present study contribute to the knowledge of the mechanisms underlying the resistance to key pyrethroids used to controlA. aegyptialong the Caribbean coast of Colombia.
Transient amplitude modulation of alpha-band oscillations by short-time intermittent closed-loop tACS
Authors: Zarubin G. , Gundlach C. , Nikulin V. , Villringer A. , Bogdan M. 
Published: January 2020

AbstractNon-invasive brain stimulation techniques such as transcranial alternating current stimulation (tACS) have recently become extensively utilized due to their potential to modulate ongoing neuronal oscillatory activity and consequently to induce cortical plasticity relevant for various cognitive functions. However, the neurophysiological basis for stimulation effects as well as their inter-individual differences are not yet understood. In the present study we used a closed-loop EEG transcranial alternating current stimulation protocol (EEG-tACS) to examine the modulation of alpha oscillations generated in occipito-parietal areas. In particular, we investigated the effects of a repeated short-time intermittent stimulation protocol (1 s in every trial) applied over the visual cortex (Cz and Oz) and adjusted according to the phase and frequency of visual alpha oscillations on the amplitude of these oscillations. Based on previous findings, we expected higher increases in alpha amplitudes for tACS applied in-phase with ongoing oscillations as compared to an application in anti-phase and this modulation to be present in low-alpha amplitude states of the visual system (eyes opened) but not high (eyes closed).Contrary to our expectations, we found a transient suppression of alpha power in inter-individually derived spatially specific parieto-occipital components obtained via the estimation of spatial filters by using the common spatial patterns approach. The amplitude modulation was independent of the phase relationship between tACS signal and alpha oscillations, and the state of the visual system manipulated via closed- and open-eye conditions. It was also absent in conventionally analyzed single-channel and multi-channel data from an average parieto-occipital region.The fact that the tACS modulation of oscillations was phase-independent suggests that mechanisms driving the effects of tACS may not be explained by entrainment alone, but rather require neuroplastic changes or transient disruption of neural oscillations. Our study also supports the notion that the response to tACS is subject specific, where the modulatory effects are shaped by the interplay between the stimulation and different alpha generators. This favors stimulation protocols as well as analysis regimes exploiting inter-individual differences, such as spatial filters to reveal otherwise hidden stimulation effects and, thereby, comprehensively induce and study the effects and underlying mechanisms of tACS.
Most small cerebral cortical veins demonstrate significant flow pulsatility: a human phase contrast MRI study at 7T
Authors: Driver Ian D , Traat Maarika , Fasano Fabrizio , Wise Richard G 
Published: January 2020

AbstractPhase contrast MRI has been used to investigate flow pulsatility in cerebral arteries, larger cerebral veins and the cerebrospinal fluid. Such measurements of intracranial pulsatility and compliance are beginning to inform understanding of the pathophysiology of conditions including normal pressure hydrocephalus, multiple sclerosis and dementias. We demonstrate the presence of flow pulsatility in small cerebral cortical veins, for the first time using phase contrast MRI at 7 Tesla, with the aim of improving our understanding of the haemodynamics of this little-studied vascular compartment. An automated method for establishing where venous flow is pulsatile is introduced, revealing significant pulsatility in 116 out of 146 veins, across 8 healthy participants, assessed in parietal and frontal regions. Distributions of pulsatility index and pulse waveform delay were characterized, indicating a small, but statistically significant (p<0.05), delay of 59±41 ms in cortical veins with respect to the superior sagittal sinus, but no differences between veins draining different arterial supply territories. Measurements of pulsatility in smaller cortical veins, a hitherto unstudied compartment closer to the capillary bed, could lead to a better understanding of intracranial compliance and cerebrovascular (patho)physiology.
Moral norm is the key
Authors: Liu Matthew Tingchi , Liu Yongdan , Mo Ziying 
Published: January 2020

PurposeThis research extends the theory of planned behaviour (TPB) and aims to study the underlying factors that influence Chinese consumers' purchase intentions towards green products. The conceptual model encompasses four elements (subjective norms, perceived behaviour control, moral norms and attitude) and one consumer response (purchase intention).Design/methodology/approachThe current research employs a questionnaire survey and two experiments. In Study 1, the hypotheses were tested using structural equation modelling with 485 consumers in China. Study 2 employed a single-factor, two-condition (morally engaged vs control), between-subject design.FindingsThe findings reveal that the morally extended TPB framework is more applicable in predicting Chinese consumers' green purchase intentions than the original TPB model. Attitude plays the most significant role in predicting purchase intentions, and moral norms prove to be a mediator of the relationship between the original construct of subjective norms and purchase intentions. The findings further revealed that moral norms comprise the underlying mechanism of the relationship between subjective norms and attitude.Originality/valueThis study therefore expands the TPB theory by including moral norms. Moreover, it contributes to the literature by clarifying the direct, indirect and total effects of each TPB element on the purchase intentions towards green products. Finally, managerial implications are given.
Customer loyalty in Sabah full service restaurant
Authors: Ing Phang Grace , Zheng Lin Ng , Xu Ming , Thurasamy Ramayah 
Published: January 2020

PurposeLoyal customers are committed to repeat patronage, make business referrals and provide publicity for the business. However, rising customer expectations and price consciousness, advancement of technology, lack of product differentiation and consumer choices have posted more challenges for customer retention. The purpose of this paper is to examine the relationships between transaction specific characteristics (i.e. food quality, service quality, atmosphere, convenience and price perception), customer satisfaction and customer loyalty (behavioral and attitudinal loyalties) in the context of Sabah full-service restaurant. The mediating effect of customer satisfaction and moderating effect of customer innovativeness were also tested.Design/methodology/approachA total of 225 valid questionnaires was collected via purposive sampling method and analyzed using Smart-PLS software 3.0.FindingsAll transaction specific characteristics have positive influences on customer satisfaction with price perception as the strongest predictor. Satisfaction had stronger effect on behavioral loyalty as compared to attitudinal loyalty. The mediating effects of customer satisfaction were only found in some of the relationships. None of the moderating effects of customer innovativeness was significant.Originality/valueUtilizing the value-percept theory and transaction specific model which combine the evaluations of service and product elements of the full-service restaurant, this study contributed to the better understanding of the relationships between transaction specific characteristics, customer satisfaction and customer loyalty. The examination of both attitudinal and behavioral loyalties provided valuable insights to practitioners and researchers in understanding full-service restaurant consumers’ repatronage intention, intention to spread positive words-of-mouth (WoM) and commitment.
Political stability, political rights and earnings management: some international evidence
Authors: Lemma Tesfaye Taddese , Lulseged Ayalew , Mlilo Mthokozisi , Negash Minga 
Published: January 2020

Purpose
This study aims to examine the impact of political stability and political rights on firm-level earnings (both accrual-based and real) management.

Design/methodology/approach
The authors develop models that link political stability, political rights, and the interplay between the two and earnings (both accrual-based and real) management. The authors analyze 63,872 firm-year observations of publicly listed, non-financial, firms drawn from 39 countries, for the period 1995 to 2016.

Findings
The authors find that political stability (political rights) attenuates (accentuates) accrual-based earnings management; political rights (political stability) accentuates (have no effect on) real earnings management; and the association between political rights and real earnings management is more pronounced in countries with better political stability.

Practical implications
The findings imply that users of financial statements should take cognizance of a country’s ambient political environment in assessing the potential for earnings management by firms.

Originality/value
No prior research examined the role of political forces in shaping firm-level earnings management behavior in a cross-country setting.