116 research outputs found
R26-WntVis reporter mice showing graded response to Wnt signal levels
The canonical Wnt signaling pathway plays a major role in the regulation of embryogenesis and organogenesis, where signal strength-dependent cellular responses are of particular importance. To assess Wnt signal levels in individual cells, and to circumvent the integration site-dependent bias shown in previous Wnt reporter lines, we constructed a new Wnt signal reporter mouse line R26-WntVis. Heptameric TCF/LEF1 binding sequences were combined with a viral minimal promoter to confer a graded response to the reporter depending on Wnt signal strengths. The histone H2B-EGFP fusion protein was chosen as the fluorescent reporter to facilitate single-cell resolution analyses. This WntVis reporter gene was then inserted into the ROSA26 locus in an orientation opposite to that of the endogenous gene. The R26-WntVis allele was introduced into Wnt3a−/− and Wnt3avt/− mutant mouse embryos and compared with wild-type embryos to assess its performance. The R26-WntVis reporter was activated in known Wnt-dependent tissues and responded in a graded fashion to signal intensity. This analysis also indicated that the major Wnt activity early in embryogenesis switched from Wnt3 to Wnt3a around E7.5. The R26-WntVis mouse line will be widely useful for the study of Wnt signal-dependent processes
Activin E Controls Energy Homeostasis in Both Brown and White Adipose Tissues as a Hepatokine
Brown adipocyte activation or beige adipocyte emergence in white adipose tissue (WAT) increases energy expenditure, leading to a reduction in body fat mass and improved glucose metabolism. We found that activin E functions as a hepatokine that enhances thermogenesis in response to cold exposure through beige adipocyte emergence in inguinal WAT (ingWAT). Hepatic activin E overexpression activated thermogenesis through Ucp1 upregulation in ingWAT and other adipose tissues including interscapular brown adipose tissue and mesenteric WAT. Hepatic activin E-transgenic mice exhibited improved insulin sensitivity. Inhibin βE gene silencing inhibited cold-induced Ucp1 induction in ingWAT. Furthermore, in vitro experiments suggested that activin E directly stimulated expression of Ucp1 and Fgf21, which was mediated by transforming growth factor-β or activin type I receptors. We uncovered a function of activin E to stimulate energy expenditure through brown and beige adipocyte activation, suggesting a possible preventive or therapeutic target for obesity
Identification of novel proteins differentially expressed in pluripotent embryonic stem cells and differentiated cells
Mammalian pluripotent stem cells possess properties of self-renewal and pluripotency. These abilities are maintained by the strict regulation of pluripotent stem cell-specific transcription factor network and unique properties of chromatin in the stem cells. Although these major signaling pathways robustly control the characteristics of stem cells, other regulatory factors, such as metabolic pathways, are also known to modulate stem cell proliferation and differentiation. In this study, we fractionated protein samples from mouse embryonic stem (ES) cells cultured with or without the leukemia inhibitory factor (LIF). Protein expression was quantified by 2-dimensional differential gel electrophoresis (2D-DIGE). In total, 44 proteins were identified as being differentially expressed in the pluripotent stem cells and the differentiated cells. Surprisingly, half of the identified proteins were the proteins localized in mitochondria, which supply cellular energy and regulate cell cycle, development, and cell death. Some of these identified proteins are involved in the metabolic function and the regulation of pluripotency. Further analysis of the identified proteins could provide new information for the manipulation of pluripotency in ES cells
Simple and effective generation of transgene-free induced pluripotent stem cells using an auto-erasable Sendai virus vector responding to microRNA-302
Transgene-free induced pluripotent stem cells (iPSCs) are valuable for both basic research and potential clinical applications. We previously reported that a replication-defective and persistent Sendai virus (SeVdp) vector harboring four reprogramming factors (SeVdp-iPS) can efficiently induce generation of transgene-free iPSCs. This vector can express all four factors stably and simultaneously without chromosomal integration and can be eliminated completely from reprogrammed cells by suppressing vector-derived RNA-dependent RNA polymerase. Here, we describe an improved SeVdp-iPS vector (SeVdp(KOSM)302L) that is automatically erased in response to microRNA-302 (miR-302), uniquely expressed in pluripotent stem cells (PSCs). Gene expression and genome replication of the SeVdp-302L vector, which contains miRNA-302a target sequences at the 3′ untranslated region of L mRNA, are strongly suppressed in PSCs. Consequently, SeVdp(KOSM)302L induces expression of reprogramming factors in somatic cells, while it is automatically erased from cells successfully reprogrammed to express miR-302. As this vector can reprogram somatic cells into transgene-free iPSCs without the aid of exogenous short interfering RNA (siRNA), the results we present here demonstrate that this vector may become an invaluable tool for the generation of human iPSCs for future clinical applications
First Data Release of the Hyper Suprime-Cam Subaru Strategic Program
The Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) is a three-layered
imaging survey aimed at addressing some of the most outstanding questions in
astronomy today, including the nature of dark matter and dark energy. The
survey has been awarded 300 nights of observing time at the Subaru Telescope
and it started in March 2014. This paper presents the first public data release
of HSC-SSP. This release includes data taken in the first 1.7 years of
observations (61.5 nights) and each of the Wide, Deep, and UltraDeep layers
covers about 108, 26, and 4 square degrees down to depths of i~26.4, ~26.5, and
~27.0 mag, respectively (5sigma for point sources). All the layers are observed
in five broad bands (grizy), and the Deep and UltraDeep layers are observed in
narrow bands as well. We achieve an impressive image quality of 0.6 arcsec in
the i-band in the Wide layer. We show that we achieve 1-2 per cent PSF
photometry (rms) both internally and externally (against Pan-STARRS1), and ~10
mas and 40 mas internal and external astrometric accuracy, respectively. Both
the calibrated images and catalogs are made available to the community through
dedicated user interfaces and database servers. In addition to the pipeline
products, we also provide value-added products such as photometric redshifts
and a collection of public spectroscopic redshifts. Detailed descriptions of
all the data can be found online. The data release website is
https://hsc-release.mtk.nao.ac.jp/.Comment: 34 pages, 20 figures, 7 tables, moderate revision, accepted for
publication in PAS
A Role for KLF4 in Promoting the Metabolic Shift via TCL1 during Induced Pluripotent Stem Cell Generation
Reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) is accompanied by morphological, functional, and metabolic alterations before acquisition of full pluripotency. Although the genome-wide effects of the reprogramming factors on gene expression are well documented, precise mechanisms by which gene expression changes evoke phenotypic responses remain to be determined. We used a Sendai virus-based system that permits reprogramming to progress in a strictly KLF4-dependent manner to screen for KLF4 target genes that are critical for the progression of reprogramming. The screening identified Tcl1 as a critical target gene that directs the metabolic shift from oxidative phosphorylation to glycolysis. KLF4-induced TCL1 employs a two-pronged mechanism, whereby TCL1 activates AKT to enhance glycolysis and counteracts PnPase to diminish oxidative phosphorylation. These regulatory mechanisms described here highlight a central role for a reprogramming factor in orchestrating the metabolic shift toward the acquisition of pluripotency during iPSC generation
The Hyper Suprime-Cam SSP survey: Overview and survey design
Hyper Suprime-Cam (HSC) is a wide-field imaging camera on the prime focus of the 8.2-m Subaru telescope on the summit of Mauna Kea in Hawaii. A team of scientists from Japan, Taiwan, and Princeton University is using HSC to carry out a 300-night multi-band imaging survey of the high-latitude sky. The survey includes three layers: the Wide layer will cover 1400 deg2 in five broad bands (grizy), with a 5 σ point-source depth of r ≈ 26. The Deep layer covers a total of 26 deg2 in four fields, going roughly a magnitude fainter, while the UltraDeep layer goes almost a magnitude fainter still in two pointings of HSC (a total of 3.5 deg2). Here we describe the instrument, the science goals of the survey, and the survey strategy and data processing. This paper serves as an introduction to a special issue of the Publications of the Astronomical Society of Japan, which includes a large number of technical and scientific papers describing results from the early phases of this survey
Baseline and Early Predictors of Good Patient Candidates for Second-Line after Sorafenib Treatment in Unresectable Hepatocellular Carcinoma
Background: Recent advances in the development of tyrosine kinase inhibitors (TKIs) have enabled patients with unresectable hepatocellular carcinoma (HCC) to receive multiple TKIs in sequence. The aim of this study was to identify predictors of good candidates for second-line treatment after disease progression during sorafenib treatment. Methods: This is a retrospective cohort study of 190 consecutive HCC patients who were treated with sorafenib in our hospital. Three criteria of good candidates for second-line TKI at the time of disease progression during sorafenib treatment were defined as follows: criterion 1 was the same as the inclusion criteria of the regorafenib for patients with hepatocellular carcinoma who progressed on sorafenib treatment (RESORCE) study, criterion 2 was the inclusion criteria of the RESORCE study plus Child–Pugh score 5, and criterion 3 was the inclusion criteria of the RESORCE study plus albumin–bilirubin (ALBI) grade 1. Factors at baseline and at week 4 during sorafenib treatment were used to predict patients fulfilling each of these three criteria. Results: The distribution of patients was 29%, 13%, and 6% in criteria 1, 2, and 3, respectively. Significant factors for meeting criterion 1 was the combination of baseline albumin >3.7 g/dL (odds ratio (OR) 2.7) plus degree of decrease in albumin (Δalbumin) at week 4 <0.2 g/dL (OR 2.6), or the combination of baseline ALBI score <−2.33 (OR 2.5) and ΔALBI at week 4 <0.255 (OR 4.9). For criterion 2, the value of baseline albumin and ALBI score was identical to criterion 1; however, Δalbumin (<0.1 g/dL) and ΔALBI score (<0.19) became stricter. For criterion 3, the value of baseline albumin (>3.8 g/dL) and ALBI (<−2.55) became stricter, as did Δalbumin (<0.1 g/dL) and ΔALBI (<0.085). Furthermore, tumor burden (>11) was selected as an additional predictor (OR 5.4). Conclusion: Predictors to satisfy the RESORCE study inclusion criteria were as follows: preserved liver function at baseline, as reflected by albumin or ALBI score, and small deterioration of liver function early during sorafenib therapy, as reflected by Δalbumin or ΔALBI at week 4. Liver function at baseline and degree of change in liver function during sorafenib treatment need to be stricter for better outcomes of liver function with disease progression
Usefulness of Circulating CYFRA21-1 in Patients as a Biomarker in Patients Taking Sorafenib or Lenvatinib for Unresectable Hepatocellular Carcinoma
Background: This study investigated the impact of serum cytokeratin 19 fragment (CYFRA21-1) level on the clinical outcomes of patients with unresectable hepatocellular carcinoma (HCC) treated with sorafenib (SOR) or lenvatinib (LEN). Methods: A total of 71 cases with unresectable HCC taking SOR or LEN were included. Univariate and multivariate analyses were performed to identify the prognostic factors in patients taking SOR or LEN. Results: Among the 71 patients taking SOR or LEN, the frequency of cases showing high CYFRA21-1 levels after administration increased compared to before the administration. There was no association between the CYFRA21-1 level and the result of treatment response using modified Response Evaluation Criteria in Solid Tumors (mRECIST) 12 weeks after the administration. Univariate analysis identified a maximum intrahepatic tumor diameter of 70 mm or more, extrahepatic metastasis, baseline alpha-fetoprotein (AFP) ≥ 2000 ng/mL, baseline AFP-L3 index ≥ 15%, baseline des-gamma-carboxy prothrombin (DCP) ≥ 1000 mAU/mL, baseline CYFRA21-1 > 3.5 ng/mL, 12-week mRECIST progressive disease (PD), 12-week DCP ratio ≥ 4, 12-week CYFRA21-1 ratio ≥ 2, administration period less than 12 weeks, ALBI grade 3 at PD, and no additional treatment after discontinuation of SOR/LEN as prognostic factors. Multivariate analysis revealed that AFP-L3 index ≥ 15%, 12-week mRECIST PD, 12-week DCP ratio ≥ 4, 12-week CYFRA21-1 ratio ≥ 2, administration period less than 12 weeks, and no additional treatment after discontinuation of SOR/LEN were independent factors. Conclusions: Patients with a high CYFRA21-1 level at baseline tend to have poor prognosis, and patients with a high CYFRA21-1 ratio 12 weeks after administration have poor prognosis. Serum CYFRA21-1 measurement may have additional effects on prognostic prediction, and it may be necessary to pay close attention to the transition to the next HCC treatment in cases whose CYFRA21-1 level is high
Steady state in experimentally produced turbidity current under a large amount of suspension supply
Turbidity current is generated in an inclined lock-gate flume under a large amount of suspension supply. By opening the gate, turbidity current generates and flows to downstream. The turbidity current maintains its interface structure and progresses with constant frontal velocity. The inner velocity profile of the quasi-steady body by ultrasound velocity profiler (UVP) falls on the similar convex lines within the fluctuations in space and time. We conclude that turbidity current progresses in a steady state flow structure with small dissipation, which is a key to transport a large amount of sediment in a long distance
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