90 research outputs found
The anti-angiogenic herbal composition Ob-X inhibits adipose tissue growth in obese mice
Objective: The growth and development of adipose tissue are thought to be associated with angiogenesis and extracellular matrix remodeling. Since the composition of the herbal extract called Ob-X has been shown to have both anti-angiogenic and matrix metalloproteinase (MMP)-inhibiting activities, we hypothesized that growth of adipose tissue can be regulated by Ob-X. Materials and Methods: The effects of Ob-X on angiogenesis and extracellular matrix remodeling were measured using in vitro and ex vivo assays. The effects of Ob-X on adipose tissue growth were investigated with nutritionally obese mice. Results: Ob-X inhibited angiogenesis in a dose-dependent manner in the human umbilical vein endothelial cell (HUVEC) tube formation assay in vitro and the rat aortic ring assay ex vivo. Ob-X also suppressed MMP activity in vitro. Administration of Ob-X to high fat diet-induced obese mice produced significant reductions in body weight gain and adipose tissue mass, compared to controls. The mass of both subcutaneous (SC) and visceral (VSC) fat was reduced in Ob-X-treated mice. The size of adipocytes in SC and VSC adipose tissues was also significantly reduced in Ob-X-treated mice. Ob-X treatment decreased the blood vessel density and MMP activity in VSC adipose tissues of nutritionally obese mice. Ob-X reduced mRNA levels of angiogenic factors (VEGF-A and FGF-2) and MMPs (MMP-2 and MMP-9), whereas it increased mRNA levels of angiogenesis inhibitors (TSP-1 and TIMP-2) in SC and VSC adipose tissues of nutritionally obese mice. Conclusion: Ob-X, which has anti-angiogenic and MMP-inhibitory activities, reduces adipose tissue mass in nutritionally induced obese mice, providing evidence that adipose tissue growth and development may be prevented by inhibiting angiogenesis. In addition, these data suggest that regulation of adipose tissue growth by inhibiting angiogenesis may alter the expression of genes involved in angiogenesis and the MMP system
Carbon-Enhanced Metal-Poor star candidates from BP/RP Spectra in DR3
Carbon-enhanced metal-poor (CEMP) stars comprise almost a third of stars with
[Fe/H] < --2, although their origins are still poorly understood. It is highly
likely that one sub-class (CEMP- stars) is tied to mass-transfer events in
binary stars, while another sub-class (CEMP-no stars) are enriched by the
nucleosynthetic yields of the first generations of stars. Previous studies of
CEMP stars have primarily concentrated on the Galactic halo, but more recently
they have also been detected in the thick disk and bulge components of the
Milky Way. DR3 has provided an unprecedented sample of over 200 million
low-resolution ( 50) spectra from the BP and RP photometers. Training
on the CEMP catalog from the SDSS/SEGUE database, we use XGBoost to identify
the largest all-sky sample of CEMP candidate stars to date. In total, we find
58,872 CEMP star candidates, with an estimated contamination rate of 12%. When
comparing to literature high-resolution catalogs, we positively identify 60-68%
of the CEMP stars in the data, validating our results and indicating a high
completeness rate. Our final catalog of CEMP candidates spans from the inner to
outer Milky Way, with distances as close as 0.8 kpc from the Galactic
center, and as far as 30 kpc. Future higher-resolution spectroscopic
follow-up of these candidates will provide validations of their classification
and enable investigations of the frequency of CEMP- and CEMP-no stars
throughout the Galaxy, to further constrain the nature of their progenitors.Comment: 19 pages, 14 figures, accepted to MNRA
Inhibition of Sodium-Glucose Cotransporter-2 during Serum Deprivation Increases Hepatic Gluconeogenesis via the AMPK/AKT/FOXO Signaling Pathway
Background Sodium-dependent glucose cotransporter 2 (SGLT2) mediates glucose reabsorption in the renal proximal tubules, and SGLT2 inhibitors are used as therapeutic agents for treating type 2 diabetes mellitus. This study aimed to elucidate the effects and mechanisms of SGLT2 inhibition on hepatic glucose metabolism in both serum deprivation and serum supplementation states. Methods Huh7 cells were treated with the SGLT2 inhibitors empagliflozin and dapagliflozin to examine the effect of SGLT2 on hepatic glucose uptake. To examine the modulation of glucose metabolism by SGLT2 inhibition under serum deprivation and serum supplementation conditions, HepG2 cells were transfected with SGLT2 small interfering RNA (siRNA), cultured in serum-free Dulbecco’s modified Eagle’s medium for 16 hours, and then cultured in media supplemented with or without 10% fetal bovine serum for 8 hours. Results SGLT2 inhibitors dose-dependently decreased hepatic glucose uptake. Serum deprivation increased the expression levels of the gluconeogenesis genes peroxisome proliferator-activated receptor gamma co-activator 1 alpha (PGC-1α), glucose 6-phosphatase (G6pase), and phosphoenolpyruvate carboxykinase (PEPCK), and their expression levels during serum deprivation were further increased in cells transfected with SGLT2 siRNA. SGLT2 inhibition by siRNA during serum deprivation induces nuclear localization of the transcription factor forkhead box class O 1 (FOXO1), decreases nuclear phosphorylated-AKT (p-AKT), and p-FOXO1 protein expression, and increases phosphorylated-adenosine monophosphate-activated protein kinase (p-AMPK) protein expression. However, treatment with the AMPK inhibitor, compound C, reversed the reduction in the protein expression levels of nuclear p-AKT and p-FOXO1 and decreased the protein expression levels of p-AMPK and PEPCK in cells transfected with SGLT2 siRNA during serum deprivation. Conclusion These data show that SGLT2 mediates glucose uptake in hepatocytes and that SGLT2 inhibition during serum deprivation increases gluconeogenesis via the AMPK/AKT/FOXO1 signaling pathway
Sucrose preferentially promotes expression of OsWRKY7 and OsPR10a to enhance defense response to blast fungus in rice
Sucrose controls various developmental and metabolic processes in plants. It also functions as a signaling molecule in the synthesis of carbohydrates, storage proteins, and anthocyanins, as well as in floral induction and defense response. We found that sucrose preferentially induced OsWRKY7, whereas other sugars (such as mannitol, glucose, fructose, galactose, and maltose) did not have the same effect. A hexokinase inhibitor mannoheptulose did not block the effect of sucrose, which is consequently thought to function directly. MG132 inhibited sucrose induction, suggesting that a repressor upstream of OsWRKY7 is degraded by the 26S proteasome pathway. The 3-kb promoter sequence of OsWRKY7 was preferentially induced by sucrose in the luciferase system. Knockout mutants of OsWRKY7 were more sensitive to the rice blast fungus Magnaporthe oryzae, whereas the overexpression of OsWRKY7 enhanced the resistance, indicating that this gene is a positive regulator in the plant defense against this pathogen. The luciferase activity driven by the OsPR10a promoter was induced by OsWRKY7 and this transcription factor bound to the promoter region of OsPR10a, suggesting that OsWRKY7 directly controls the expression of OsPR10a. We conclude that sucrose promotes the transcript level of OsWRKY7, thereby increasing the expression of OsPR10a for the defense response in rice
Exendin-4 Improves Steatohepatitis by Increasing Sirt1 Expression in High-Fat Diet-Induced Obese C57BL/6J Mice
The effects of exendin-4 on Sirt1 expression as a mechanism of reducing fatty liver have not been previously reported. Therefore, we investigated whether the beneficial effects of exendin-4 treatment on fatty liver are mediated via Sirt1 in high-fat (HF) diet-induced obese C57BL/6J mice and related cell culture models. Exendin-4 treatment decreased body weight, serum free fatty acid (FA), and triglyceride levels in HF-induced obese C57BL/6J mice. Histological analysis showed that exendin-4 reversed HF-induced hepatic accumulation of lipids and inflammation. Exendin-4 treatment increased mRNA and protein expression of Sirt1 and its downstream factor, AMPK, in vivo and also induced genes associated with FA oxidation and glucose metabolism. In addition, a significant increase in the hepatic expression of Lkb1 and Nampt mRNA was observed in exendin-4-treated groups. We also observed increased expression of phospho-Foxo1 and GLUT2, which are involved in hepatic glucose metabolism. In HepG2 and Huh7 cells, mRNA and protein expressions of GLP-1R were increased by exendin-4 treatment in a dose-dependent manner. Exendin-4 enhanced protein expression of Sirt1 and phospho-AMPKα in HepG2 cells treated with 0.4 mM palmitic acid. We also found that Sirt1 was an upstream regulator of AMPK in hepatocytes. A novel finding of this study was the observation that expression of GLP-1R is proportional to exendin-4 concentration and exendin-4 could attenuate fatty liver through activation of Sirt1
The Science Performance of JWST as Characterized in Commissioning
This paper characterizes the actual science performance of the James Webb
Space Telescope (JWST), as determined from the six month commissioning period.
We summarize the performance of the spacecraft, telescope, science instruments,
and ground system, with an emphasis on differences from pre-launch
expectations. Commissioning has made clear that JWST is fully capable of
achieving the discoveries for which it was built. Moreover, almost across the
board, the science performance of JWST is better than expected; in most cases,
JWST will go deeper faster than expected. The telescope and instrument suite
have demonstrated the sensitivity, stability, image quality, and spectral range
that are necessary to transform our understanding of the cosmos through
observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures;
https://iopscience.iop.org/article/10.1088/1538-3873/acb29
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