40 research outputs found
Velocity Structure of Jets in Coronal Hole
Velocity structures of jets in a coronal hole have been derived for the first
time. Hinode observations revealed the existence of many bright points in
coronal holes. They are loop-shaped and sometimes associated with coronal jets.
Spectra obtained with the Extreme ultraviolet Imaging Spectrometer (EIS) on
board Hinode are analyzed to infer Doppler velocity of bright loops and jets in
a coronal hole of the north polar region. Elongated jets above bright loops are
found to be blue-shifted by 30 km/s at maximum, while foot points of bright
loops are red-shifted. Blue-shifts detected in coronal jets are interpreted as
upflows produced by magnetic reconnection between emerging flux and the ambient
field in the coronal hole.Comment: 11 pages, 7 figures, accepted for publication in PASJ Hinode special
issu
GALAXY CRUISE: Deep Insights into Interacting Galaxies in the Local Universe
We present the first results from GALAXY CRUISE, a community (or citizen)
science project based on data from the Hyper Suprime-Cam Subaru Strategic
Program (HSC-SSP). The current paradigm of galaxy evolution suggests that
galaxies grow hierarchically via mergers, but our observational understanding
of the role of mergers is still limited. The data from HSC-SSP are ideally
suited to improve our understanding with improved identifications of
interacting galaxies thanks to the superb depth and image quality of HSC-SSP.
We have launched a community science project, GALAXY CRUISE, in 2019 and
collected over 2 million independent classifications of 20,686 galaxies at z <
0.2. We first characterize the accuracy of the participants' classifications
and demonstrate that it surpasses previous studies based on shallower imaging
data. We then investigate various aspects of interacting galaxies in detail. We
show that there is a clear sign of enhanced activities of super massive black
holes and star formation in interacting galaxies compared to those in isolated
galaxies. The enhancement seems particularly strong for galaxies undergoing
violent merger. We also show that the mass growth rate inferred from our
results is roughly consistent with the observed evolution of the stellar mass
function. The 2nd season of GALAXY CRUISE is currently under way and we
conclude with future prospects. We make the morphological classification
catalog used in this paper publicly available at the GALAXY CRUISE website,
which will be particularly useful for machine-learning applications.Comment: 23 pages, 22 figures, PASJ in press. Data available at
https://galaxycruise.mtk.nao.ac.jp/en/for_researchers.htm
Extracellular vesicles from senescent hepatic stellate cells promote cell viability of hepatoma cells through increasing EGF secretion from differentiated THP?1 cells
Since the discovery of the senescence-associated secretory phenotype, the role of senescent hepatic stellate cells (HSCs) in hepatocellular carcinoma (HCC) development has gained increasing attention. Similar to cytokines, extracellular vesicles (EVs) are essential for intercellular communication. However, the function of EVs derived from senescent HSCs in HCC progression has not been extensively studied. The aims of the present study were to characterize the EVs derived from senescent HSCs and determine their role in the tumor microenvironment. Cellular senescence was induced in human hepatic stellate cells (HHSteCs) with various concentrations of etoposide. Induction was confirmed using EdU staining and 53BP1 and p21 immunostaining. EVs were isolated by ultracentrifugation and analyzed by nanoparticle tracking analysis. Multiplex immunoassays were used to compare the levels of growth factors secreted from hepatoma cell lines and macrophage cells pretreated with EVs derived from senescent HHSteCs (senescent EVs) with those pretreated with EVs derived from normal cultured HHSteCs (normal EVs). Treatment with 25 μM etoposide for 3 days was the most effective at inducing senescence in HHSteCs. This finding was confirmed by induction of irreversible cell-cycle arrest, upregulation of 53BP1 and p21 expression, and increased SA-β-gal staining. Senescent HHSteCs released increased quantities of EV particles compared with normally cultured HHSteCs. Multiplex analysis revealed that there was no difference between hepatoma cell lines treated with normal EVs and those treated with senescent EVs in growth factor secretion. In contrast, the secretion of epidermal growth factor (EGF) was increased by macrophage cells treated with senescent EVs compared with those treated with normal EVs. Furthermore, senescent EVs did not affect the viability of hepatoma cells but increased the viability of hepatoma cells co-cultured with macrophage cells. In conclusion, the release of EVs from senescent HSCs was higher compared with normal HSCs. Furthermore, senescent EVs promoted HCC development by upregulating EGF secretion from macrophages
The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force
「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection
DOCK2 is involved in the host genetics and biology of severe COVID-19
「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target
Identification of biosynthetic intermediates for the mating hormone α2 of the plant pathogen Phytophthora
Distribution of Tributyltin in Tissues of Mature Japanese Whiting, Sillago japonica and Their Eggs
The McGill Pain Questionnaire, Japanese Version, Reconsidered: Confirming the Theoretical Structure
BACKGROUND: Based on a tripartite theoretical model of pain, the Pain Rating Index (PRI) of the McGill Pain Questionnaire (MPQ) continues to be one of the most frequently used instruments to measure clinical pain. However, language and cultural barriers have hindered its wide use and standardization in Japan. Although a number of exploratory factor analysis studies have failed to support consistently the theoretical structure of the MPQ, a few previous confirmatory factor analysis studies did statistically support the a priori model