243 research outputs found

    Epigenetic Editing of Ascl1 Gene in Neural Stem Cells by Optogenetics

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    Enzymes involved in epigenetic processes such as methyltransferases or demethylases are becoming highly utilized for their persistent DNA or histone modifying efficacy. Herein, we have developed an optogenetic toolbox fused to the catalytic domain (CD) of DNA-methyltransferase3A (DNMT3A-CD) or Ten-Eleven Dioxygenase-1 (TET1-CD) for loci-specific alteration of the methylation state at the promoter of Ascl1 (Mash1), a candidate proneuron gene. Optogenetical protein pairs, CRY2 linked to DNMT3A-CD or TET1-CD and CIB1 fused to a Transcription Activator-Like Element (TALE) locating an Ascl1 promoter region, were designed for site specific epigenetic editing. A differentially methylated region at the Ascl1 promoter, isolated from murine dorsal root ganglion (hypermethylated) and striated cells (hypomethylated), was targeted with these optogenetic-epigenetic constructs. Optimized blue-light illumination triggered the co-localization of TALE constructs with DNMT3A-CD or TET1-CD fusion proteins at the targeted site of the Ascl1 promoter. We found that this spatiotemporal association of the fusion proteins selectively alters the methylation state and also regulates gene activity. This proof of concept developed herein holds immense promise for the ability to regulate gene activity via epigenetic modulation with spatiotemporal precision

    Clinical Manifestations Vary with Different Age Spectrums in Infants with Kawasaki Disease

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    Background. Kawasaki disease (KD) is an acute systemic vasculitis with unknown etiology. The diagnosis of KD depends on clinical manifestations. The prevalence of coronary artery abnormality (CAA) is 11.0% and results in cardiac sequelae, such as myocardial infarction or coronary aneurysm, which are the most serious complications in KD. Methods. We divided KD's children into different age groups: ≤6 months old, 7 months to 1 year old, and >1 year old, respectively. Different parameters were compared in each group. Results. Infants ≤6 months old are less likely to fulfill KD's major diagnostic criteria within 10 days, are prone to develop incomplete KD with the lowest cholesterol level, and have the greatest chance to have CAA and the laboratory features associated with CAA, such as the longest time needed to confirm CA diagnosis, lower hemoglobin level, lower albumin level, and higher platelet count. Infants <1 year old develop higher percentage of leukocytosis and sterile pyuria. But this group has fewer patients with neck lymphadenopathy

    Understanding the Role of Knowledge Co-Production between Users and Developers in ISD Project: An Intellectual Capital Perspective

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    Information system development (ISD) has long been treated as that process that system developers craft an artifact to support business operation based on their special expertise. However, a significant portion of projects still have failed because the developed outcome cannot fit users’ needs. An emerging internal service concept indicates that, by treating ISD as one type of service, the requirement definition can be viewed as a co-production process in which users and developers integrate their own knowledge. By incorporating this concept into research design and taking intellectual capital perspective into account, this study proposed a model to examine the antecedents and consequences of knowledge co-production between users and developers. Data collected from 267 developers confirmed our hypotheses that knowledge co-production can benefit ISD outcomes, and common knowledge, relational capital and participative decision-making between these two parties increase the effectiveness of knowledge co-production effectively. Lastly, the implications toward academic and practitioner are also provided

    Terrestrial water storage anomalies emphasize interannual variations in global mean sea level during 1997-1998 and 2015-2016 El Nino Events

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    © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Kuo, Y.-N., Lo, M.-H., Liang, Y.-C., Tseng, Y.-H., & Hsu, C.-W. Terrestrial water storage anomalies emphasize interannual variations in global mean sea level during 1997-1998 and 2015-2016 El Nino Events. Geophysical Research Letters, 48(18), (2021): e2021GL094104, https://doi.org/10.1029/2021GL094104.Interannual variations in global mean sea level (GMSL) closely correlate with the evolution of El Niño-Southern Oscillation. However, GMSL differences occur in extreme El Niños; for example, in the 2015–2016 and 1997–1998 El Niños, the peak GMSL during the mature stage of the former (9.00 mm) is almost 2.5 times higher than the latter (3.72 mm). Analyses from satellite and reanalysis data sets show that the disparity in GMSL is primarily due to barystatic (ocean mass) changes. We find that the 2015–2016 event developed not purely as an Eastern Pacific El Niño event but with Central Pacific (CP) El Niño forcing. CP El Niños contribute to a stronger negative anomaly of global terrestrial water storage and subsequent higher barystatic heights. Our results suggest that the mechanism of hydrology-related interannual variations of GMSL should be further emphasized, as more CP El Niño events are projected to occur.This study was supported by a grant of MOST 106-2111-M-002-010-MY4 to National Taiwan University

    Increased ATP generation in the host cell is required for efficient vaccinia virus production

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    To search for cellular genes up-regulated by vaccinia virus (VV) infection, differential display-reverse transcription-polymerase chain reaction (ddRT-PCR) assays were used to examine the expression of mRNAs from mock-infected and VV-infected HeLa cells. Two mitochondrial genes for proteins that are part of the electron transport chain that generates ATP, ND4 and CO II, were up-regulated after VV infection. Up-regulation of ND4 level by VV infection was confirmed by Western blotting analysis. Up-regulation of ND4 was reduced by the MAPK inhibitor, apigenin, which has been demonstrated elsewhere to inhibit VV replication. The induction of ND4 expression occurred after viral DNA replication since ara C, an inhibitor of poxviral DNA replication, could block this induction. ATP production was increased in the host cells after VV infection. Moreover, 4.5 μM oligomycin, an inhibitor of ATP production, reduced the ATP level 13 hr after virus infection to that of mock-infected cells and inhibited viral protein expression and virus production, suggesting that increased ATP production is required for efficient VV production. Our results further suggest that induction of ND4 expression is through a Bcl-2 independent pathway

    Cis‐acting allele specific expression (ASE) differences induced by alcohol and impacted by sex as well as parental genotype of origin

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    Background Alcohol use disorders (AUDs) are influenced by complex interactions between the genetics of the individual and their environment. We have previously identified hundreds of polygenic genetic variants between the selectively bred high and low alcohol drinking (HAD and LAD) rat lines. Here we report allele specific expression (ASE) differences, between the HAD2 and LAD2 rat lines. Methods The HAD2 and LAD2 rats which have been sequenced were reciprocally crossed to generate 10 litters of F1 progeny. For 5 of these litters, the sire was HAD2; and, for the other 5 litters, the sire was a LAD2. From these 10 litters, two males and two females were picked from each F1 litter (N = 40 total). The F1‐pups were divided, with balancing for sex and direction of cross, into an alcohol (15%) vs a water control group. Alcohol‐drinking started in the middle of adolescence (~PND 35) and lasted 9 weeks. At the end of these treatments, rats were euthanized, the nucleus accumbens was dissected, and RNA was processed for RNA‐sequencing and ASE analyses. Results Analyses revealed that adolescent ethanol drinking, individual ethanol drinking levels, parentage, and sex‐of‐animal affected ASEs of about 300 genes. The identified genes included those associated with ethanol metabolism (e.g., Aldh2); neuromodulatory function [e.g., Cckbr, Slc6a7, and Slc1a1]; ion channel activity (e.g., Kcnc3); as well as other synaptic and epigenetic function. Conclusion These data indicate that ethanol drinking differentially amplified paternal vs maternal allelic contribution to the transcriptome. We hypothesize that this was due, at least in part, to ethanol‐induced changes in cis‐regulation of polymorphisms previously identified between the HAD2 and LAD2 rat lines. This report highlights the complexity of gene‐by‐environment interactions mediating a genetic predisposition for, and/or the active development of, alcohol use disorders

    Cell-Wide DNA De-Methylation and Re-Methylation of Purkinje Neurons in the Developing Cerebellum

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    Global DNA de-methylation is thought to occur only during pre-implantation and gametogenesis in mammals. Scalable, cell-wide de-methylation has not been demonstrated beyond totipotent stages. Here, we observed a large scale de-methylation and subsequent re-methylation (CDR) (including 5-methylcytosine (5mC) and 5-hydroxylmethylcytosine (5hmC)) in post-mitotic cerebellar Purkinje cells (PC) through the course of normal development. Through single cell immuno-identification and cell-specific quantitative methylation assays, we demonstrate that the CDR event is an intrinsically scheduled program, occurring in nearly every PC. Meanwhile, cerebellar granule cells and basket interneurons adopt their own DNA methylation program, independent of PCs. DNA de-methylation was further demonstrated at the gene level, on genes pertinent to PC development. The PC, being one of the largest neurons in the brain, may showcase an amplified epigenetic cycle which may mediate stage transformation including cell cycle arrest, vast axonal-dendritic growth, and synaptogenesis at the onset of neuronal specificity. This discovery is a key step toward better understanding the breadth and role of DNA methylation and de-methylation during neural ontology

    Drain tube migration into the anastomotic site of an esophagojejunostomy for gastric small cell carcinoma: short report

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    Intraluminal migration of a drain through an anastomotic site is a rare complication of gastric surgery. Case Presentation: We herein report the intraluminal migration of a drain placed after a lower esophagectomy and total gastrectomy with Roux-en-Y anastomosis for gastric small cell carcinoma. Persistent drainage was noted 1 month after surgery, and radiographic studies were consistent with drain tube migration. Endoscopy revealed the drain had migrated into the esophagojejunostomy anastomotic site. The drain was removed from outside of abdominal wound while observing the anastomotic site endoscopically. The patient was treated with suction via a nasogastric tube drain for 5 days, and thereafter had an uneventful recovery. Conclusions: Though drain tube migration is a rare occurrence, it should be considered in patients with persistent drainage who have undergone gastric surgery

    Optogenetic regulation of site-specific subtelomeric DNA methylation

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    Telomere length homeostasis, critical for chromosomal integrity and genome stability, is controlled by intricate molecular regulatory machinery that includes epigenetic modifications. Here, we examine site-specific and spatiotemporal alteration of the subtelomeric methylation of CpG islands using optogenetic tools to understand the epigenetic regulatory mechanisms of telomere length maintenance. Human DNA methyltransferase3A (DNMT3A) were assembled selectively at chromosome ends by fusion to cryptochrome 2 protein (CRY2) and its interacting complement, the basic helix loop helix protein-1 (CIB1). CIB1 was fused to the telomere-associated protein telomere repeat binding factor-1 (TRF1), which localized the protein complex DNMT3A-CRY2 at telomeric regions upon excitation by blue-light monitored by single-molecule fluorescence analyses. Increased methylation was achieved selectively at subtelomeric CpG sites on the six examined chromosome ends specifically after blue-light activation, which resulted in progressive increase in telomere length over three generations of HeLa cell replications. The modular design of the fusion constructs presented here allows for the selective substitution of other chromatin modifying enzymes and for loci-specific targeting to regulate the epigenetic pathways at telomeres and other selected genomic regions of interest
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