290 research outputs found
Expression and function of CCN2-derived circRNAs in chondrocytes
Cellular communication network factor 2 (CCN2) molecules promote endochondral ossification and articular cartilage regeneration, and circular RNAs (circRNAs), which arise from various genes and regulate gene expression by adsorbing miRNAs, are known to be synthesized from CCN2 in human vascular endothelial cells and other types of cells. However, in chondrocytes, not only the function but also the presence of CCN2-derived circRNA remains completely unknown. In the present study, we investigated the expression and function of CCN2-derived circRNAs in chondrocytes. Amplicons smaller than those from known CCN2-derived circRNAs were observed using RT-PCR analysis that could specifically amplify CCN2-derived circRNAs in human chondrocytic HCS-2/8 cells. The nucleotide sequences of the PCR products indicated novel circRNAs in the HCS-2/8 cells that were different from known CCN2-derived circRNAs. Moreover, the expression of several Ccn2-derived circRNAs in murine chondroblastic ATDC5 cells was confirmed and observed to change alongside chondrocytic differentiation. Next, one of these circRNAs was knocked down in HCS-2/8 cells to investigate the function of the human CCN2-derived circRNA. As a result, CCN2-derived circRNA knockdown significantly reduced the expression of aggrecan mRNA and proteoglycan synthesis. Our data suggest that CCN2-derived circRNAs are expressed in chondrocytes and play a role in chondrogenic differentiation
Metastases of soft tissue sarcoma to the liver: A Historical Cohort Study from a Hospital-based Cancer Registry
Background: Hepatic metastasis of soft tissue sarcoma is rare compared to lung metastasis, and the literature is scarce. We examined the risk of hepatic metastasis according to the site of occurrence and histological type. Methods: From a Hospital-based Cancer Registry, 658 patients registered between 2007 and 2017 with soft tissue sarcomas were evaluated. The exclusion criteria were gastrointestinal stromal tumors, tumors of unknown origin, and follow-up periods of less than 1 month. SPSS 25 was used for statistical analysis. Results: The risk of hepatic metastasis was significantly higher in the retroperitoneum (HR, 5.981; 95% CI, 2.793-12.808) and leiomyosarcoma (HR, 4.303; 95% CI, 1.782-10.390). Multivariate analysis showed that the risk of hepatic metastasis as first distant metastasis was high in leiomyosarcoma (HR, 4.546; 95% CI, 2.275-9.086) and retroperitoneal onset (HR, 4.588; 95% CI, 2.280-9.231). The 2-year survival rate after hepatic metastasis was 21.7%. Conclusions: The onset of hepatic metastasis indicates a poor prognosis. However, hepatic metastasis from retroperitoneal sarcoma and leiomyosarcoma may be the first distant metastasis in some cases. For retroperitoneal sarcoma and leiomyosarcoma, additional screening for hepatic metastasis such as contrast CT should be considered during staging and follow-up after treatment.ArticleCancer medicine 17(17) : 6159-6165(2020)journal articl
Ultra-broadband surface-normal coherent optical receiver with nanometallic polarizers
A coherent receiver that can demodulate high-speed in-phase and quadrature
signals of light is an essential component for optical communication,
interconnects, imaging, and computing. Conventional waveguide-based coherent
receivers, however, exhibit large footprints, difficulty in coupling a large
number of spatial channels efficiently, and limited operating bandwidth imposed
by the waveguide-based optical hybrid. Here, we present a surface-normal
coherent receiver with nanometallic-grating-based polarizers integrated
directly on top of photodetectors without the need for an optical hybrid
circuit. Using a fabricated device with the active section occupying a
70-{\mu}m-square footprint, we demonstrate demodulation of high-speed (up to 64
Gbaud) coherent signals in various formats. Moreover, ultra-broadband operation
from 1260 nm to 1630 nm is demonstrated, thanks to the wavelength-insensitive
nanometallic polarizers. To our knowledge, this is the first demonstration of a
surface-normal homodyne optical receiver, which can easily be scaled to a
compact two-dimensional arrayed device to receive highly parallelized coherent
signals.Comment: 23 pages, 4 figures (main manuscript) + 4 pages, 2 figures
(supporting info
Swift X-Ray Observations of Classical Novae. II. The Super Soft Source sample
The Swift GRB satellite is an excellent facility for studying novae. Its
rapid response time and sensitive X-ray detector provides an unparalleled
opportunity to investigate the previously poorly sampled evolution of novae in
the X-ray regime. This paper presents Swift observations of 52
Galactic/Magellanic Cloud novae. We included the XRT (0.3-10 keV) X-ray
instrument count rates and the UVOT (1700-8000 Angstroms) filter photometry.
Also included in the analysis are the publicly available pointed observations
of 10 additional novae the X-ray archives. This is the largest X-ray sample of
Galactic/Magellanic Cloud novae yet assembled and consists of 26 novae with
super soft X-ray emission, 19 from Swift observations. The data set shows that
the faster novae have an early hard X-ray phase that is usually missing in
slower novae. The Super Soft X-ray phase occurs earlier and does not last as
long in fast novae compared to slower novae. All the Swift novae with
sufficient observations show that novae are highly variable with rapid
variability and different periodicities. In the majority of cases, nuclear
burning ceases less than 3 years after the outburst begins. Previous
relationships, such as the nuclear burning duration vs. t_2 or the expansion
velocity of the eject and nuclear burning duration vs. the orbital period, are
shown to be poorly correlated with the full sample indicating that additional
factors beyond the white dwarf mass and binary separation play important roles
in the evolution of a nova outburst. Finally, we confirm two optical phenomena
that are correlated with strong, soft X-ray emission which can be used to
further increase the efficiency of X-ray campaigns.Comment: Accepted to ApJ Supplements. Full data for Table 2 and Figure 17
available in the electronic edition. New version of the previously posted
paper since the earlier version was all set in landscape mod
Transcriptome-wide discovery of circular RNAs in Archaea
Circular RNA forms had been described in all domains of life. Such RNAs were shown to have diverse biological functions, including roles in the life cycle of viral and viroid genomes, and in maturation of permuted tRNA genes. Despite their potentially important biological roles, discovery of circular RNAs has so far been mostly serendipitous. We have developed circRNA-seq, a combined experimental/computational approach that enriches for circular RNAs and allows profiling their prevalence in a whole-genome, unbiased manner. Application of this approach to the archaeon Sulfolobus solfataricus P2 revealed multiple circular transcripts, a subset of which was further validated independently. The identified circular RNAs included expected forms, such as excised tRNA introns and rRNA processing intermediates, but were also enriched with non-coding RNAs, including C/D box RNAs and RNase P, as well as circular RNAs of unknown function. Many of the identified circles were conserved in Sulfolobus acidocaldarius, further supporting their functional significance. Our results suggest that circular RNAs, and particularly circular non-coding RNAs, are more prevalent in archaea than previously recognized, and might have yet unidentified biological roles. Our study establishes a specific and sensitive approach for identification of circular RNAs using RNA-seq, and can readily be applied to other organisms
Gene Expression Profiles of Intracellular and Membrane Progesterone Receptor Isoforms in the Mediobasal Hypothalamus During Pro-Oestrus
Progesterone action is mediated by its binding to specific receptors. Two progesterone receptor (PR) isoforms (PRA and PRB), three membrane progesterone receptor (mPR) subtypes (mPRĪ±, mPRĪ² and mPRĪ³) and at least one progesterone membrane-binding protein [PR membrane component 1 (PRmc1)] have been identified in reproductive tissues and brain of various species. In the present study, we examined gene expression patterns for PR isoforms, mPR subtypes and PRmc1 in the rat mediobasal hypothalamus (MBH) during pro-oestrus. The mRNA level for each receptor subtype was quantified by a real-time reverse transcriptase-polymerase chain reaction (RT-PCR) at the time points: 13.00 h on dioestrous day 2; 09.00, 13.00, 17.00 and 22.00 h on pro-oestrus; and 13.00 h on oestrus. For PR, one primer set amplified PRA+PRB, whereas a second primer set amplified PRB. As expected, PRA+PRB mRNA expression was greater than PRB in MBH tissue. PRB mRNA levels increased throughout the day on pro-oestrus, with the highest levels being observed at 17.00 h. PRB mRNA levels in the MBH were increased by 2.4- and 3.0-fold at 13.00 and 17.00 h, respectively, on pro-oestrus compared to 13.00 h on dioestrous day 2. There were differential mRNA expression levels for mPRs and PRmc1 in the MBH, with the highest expression for PRmc1 and the lowest for mPRĪ³. The mPRĪ± mRNA contents at 13.00 and 17.00 h on pro-oestrus were increased by 1.5-fold compared to that at 13.00 h on dioestrous day 2. The mPRĪ² mRNA levels at 13.00 and 17.00 h on pro-oestrus were 2.5- and 2.4-fold higher compared to that at 13.00 h on dioestrous day 2, respectively. PRA+PRB, mPRĪ³ and PRmc1 mRNA levels did not vary on pro-oestrus. These findings suggest that the higher expression of PRB, mPRĪ± and mPRĪ² in the MBH on pro-oestrous afternoon may influence both genomic and nongenomic mechanisms of progesterone action during the critical pre-ovulatory period
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