1,134 research outputs found

    Carvedilol inhibits EGF-mediated JB6 P+ colony formation through a mechanism independent of adrenoceptors

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    Carvedilol is reported to prevent cancers in humans and animal models. However, a molecular mechanism has yet to be established, and the extent to which other P-blockers are chemopreventive remains relatively unknown. A comparative pharmacological approach was utilized with the expectation that a mechanism of action could be devised. JB6 CI 41-5a (JB6 P+) murine epidermal cells were used to elucidate the chemopreventative properties of beta-blockers, as JB6 P+ cells recapitulate in vivo tumor promotion and chemoprevention. The initial hypothesis was that beta-blockers that are GRK/beta-arrestin biased agonists, like carvedilol, are chemopreventive. Sixteen beta-blockers of different classes, isoproterenol, and HEAT HCI were individually co-administered with epidermal growth factor (EGF) to JB6 P+ cells to examine the chemopreventative properties of each ligand. Cytotoxicity was examined to ensure that the anti-transformation effects of each ligand were not due to cellular growth inhibition. Many of the examined p-blockers suppressed EGF-induced JB6 P+ cell transformation in a non-cytotoxic and concentration-dependent manner. However, the IC50 values are high for the most potent inhibitors (243, 326, and 431 nM for carvedilol, labetalol, and alprenolol, respectively) and there is no correlation between pharmacological properties and inhibition of transformation. Therefore, the role of alpha 1- and beta 2-adrenergic receptors (AR) was examined by standard competition assays and shRNA targeting beta 2-ARs, the only beta-AR expressed in JB6 P+ cells. The results reveal that pharmacological inhibition of alpha 1- and beta 2-ARs and genetic knockdown of beta 2-ARs did not abrogate carvedilol-mediated inhibition of EGF-induced JB6 P+ cell transformation. Furthermore, topical administration of carvedilol protected mice from UV-induced skin damage, while genetic ablation of beta 2-ARs increased carvedilol-mediated effects. Therefore, the prevailing hypothesis that the chemopreventive property of carvedilol is mediated through P-ARs is not supported by this data.National Cancer Institute of the National Institutes of Health [R15CA227946]; Western University of Health Sciences; Summer Student Research Program (National Center for Toxicological Research, US. FDA)Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

    Nanoscale hepatoprotective herbal decoction attenuates hepatic stellate cell activity and chloroform-induced liver damage in mice

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    Sherry Huang1, Shu-Jen Chang2, Miffy Yang3, Justin Jin-Ching Chen3, Walter H Chang41Department of Biomedical Engineering, Chung Yuan Christian University, Chungli, Taiwan; 2School of Pharmacy, China Medical University, Taichung, Taiwan; 3Center for Nano Bioengineering, 4Department of Biomedical Engineering, Chung Yuan Christian University, Chungli, TaiwanBackground: San-Huang-Xie-Xin-Tang (SHXXT) decoction, a traditional Chinese medicine containing Rhei rhizome, Coptidis rhizome, and Scutellariae radix, is widely used in hepatoprotective therapy. However, preparation of the decoction requires addition of boiling water that causes loss of numerous effective components.Methods: To improve the bioavailability of the decoction, nanoscale SHXXT was developed. Chloroform-induced liver injury and hepatic stellate cell activity in mice were used to demonstrate the hepatoprotective characteristics of nanoscale SHXXT decoction.Results: Liver/body weight ratio and serum aspartate and alanine aminotranferase levels were recovered by the nanoscale SHXXT. TIMP-1 gene expression was inhibited and MMP-2 gene expression was accelerated in activated hepatic stellate cells.Conclusion: Nanoscale SHXXT decoction prepared in room temperature water could have preserved hepatoprotective ability. The results of this study indicate that nanoscale SHXXT could be extracted easily. The simple preparation of this herbal decoction is more convenient and energy-efficient.Keywords: Chinese herb medicine, San-Huang-Xie-Xin-Tang, nanoparticle, liver fibrosis&nbsp

    H0LiCOW III. Quantifying the effect of mass along the line of sight to the gravitational lens HE 0435-1223 through weighted galaxy counts

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    Based on spectroscopy and multiband wide-field observations of the gravitationally lensed quasar HE 0435-1223, we determine the probability distribution function of the external convergence κext\kappa_\mathrm{ext} for this system. We measure the under/overdensity of the line of sight towards the lens system and compare it to the average line of sight throughout the universe, determined by using the CFHTLenS as a control field. Aiming to constrain κext\kappa_\mathrm{ext} as tightly as possible, we determine under/overdensities using various combinations of relevant informative weighing schemes for the galaxy counts, such as projected distance to the lens, redshift, and stellar mass. We then convert the measured under/overdensities into a κext\kappa_\mathrm{ext} distribution, using ray-tracing through the Millennium Simulation. We explore several limiting magnitudes and apertures, and account for systematic and statistical uncertainties relevant to the quality of the observational data, which we further test through simulations. Our most robust estimate of κext\kappa_\mathrm{ext} has a median value κextmed=0.004\kappa^\mathrm{med}_\mathrm{ext} = 0.004 and a standard deviation of σκ=0.025\sigma_\kappa = 0.025. The measured σκ\sigma_\kappa corresponds to 2.5%2.5\% uncertainty on the time delay distance, and hence the Hubble constant H0H_0 inference from this system. The median κextmed\kappa^\mathrm{med}_\mathrm{ext} value is robust to ∼0.005\sim0.005 (i.e. ∼0.5%\sim0.5\% on H0H_0) regardless of the adopted aperture radius, limiting magnitude and weighting scheme, as long as the latter incorporates galaxy number counts, the projected distance to the main lens, and a prior on the external shear obtained from mass modeling. The availability of a well-constrained κext\kappa_\mathrm{ext} makes \hequad\ a valuable system for measuring cosmological parameters using strong gravitational lens time delays.Comment: 24 pages, 17 figures, 6 tables. Submitted to MNRA

    Formation of a toxic metabolite from gentamicin by a hepatic cytosolic fraction

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    We have demonstrated recently that incubation of the aminoglycoside gentamicin with an hepatic post-mitochondrial fraction produces a compound toxic to sensory cells from the inner ear in short-term culture; in contrast, the parent aminoglycoside was non-toxic in vitro (Huang MY and Schacht J, Biochem Pharmacol 40: R11-R14, 1990). In the present study, we investigated the subcellular distribution of the enzymatic activity and the nature of the metabolite. Isolated outer hair cells from the guinea pig cochlea were used to assay for cytotoxicity. The enzyme(s) responsible for this novel reaction of aminoglycosides was exclusively localized to the cytosolic fraction of guinea pig liver. No activity was detected in nuclear, lysosomal/mitochondrial or microsomal preparations. Furthermore, the toxin-forming enzymatic activity was associated with the high molecular weight fraction of the cytosol and did not require low molecular weight components. Filtration of the toxin through molecular weight cut-off membranes showed a molecular size of approximately 500. This evidence is consistent with the toxin being a gentamicin derivative.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30106/1/0000478.pd

    Notch ligand Delta-like 1 promotes in vivo vasculogenesis in human cord blood-derived endothelial colony forming cells

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    BACKGROUND AIMS: Human cord blood (CB) is enriched in circulating endothelial colony forming cells (ECFCs) that display high proliferative potential and in vivo vessel forming ability. Because Notch signaling is critical for embryonic blood vessel formation in utero, we hypothesized that Notch pathway activation may enhance cultured ECFC vasculogenic properties in vivo. METHODS: In vitro ECFC stimulation with an immobilized chimeric Notch ligand (Delta-like1(ext-IgG)) led to significant increases in the mRNA and protein levels of Notch regulated Hey2 and EphrinB2 that were blocked by treatment with γ-secretase inhibitor addition. However, Notch stimulated preconditioning in vitro failed to enhance ECFC vasculogenesis in vivo. In contrast, in vivo co-implantation of ECFCs with OP9-Delta-like 1 stromal cells that constitutively expressed the Notch ligand delta-like 1 resulted in enhanced Notch activated ECFC-derived increased vessel density and enlarged vessel area in vivo, an effect not induced by OP9 control stromal implantation. RESULTS: This Notch activation was associated with diminished apoptosis in the exposed ECFC. CONCLUSIONS: We conclude that Notch pathway activation in ECFC in vivo via co-implanted stromal cells expressing delta-like 1 promotes vasculogenesis and augments blood vessel formation via diminishing apoptosis of the implanted ECFC

    Differential Developmental Deficits in Retinal Function in the Absence of either Protein Tyrosine Sulfotransferase-1 or -2

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    To investigate the role(s) of protein-tyrosine sulfation in the retina and to determine the differential role(s) of tyrosylprotein sulfotransferases (TPST) 1 and 2 in vision, retinal function and structure were examined in mice lacking TPST-1 or TPST-2. Despite the normal histologic retinal appearance in both Tpst1−/− and Tpst2−/− mice, retinal function was compromised during early development. However, Tpst1−/− retinas became electrophysiologically normal by postnatal day 90 while Tpst2−/− mice did not functionally normalize with age. Ultrastructurally, the absence of TPST-1 or TPST-2 caused minor reductions in neuronal plexus. These results demonstrate the functional importance of protein-tyrosine sulfation for proper development of the retina and suggest that the different phenotypes resulting from elimination of either TPST-1 or -2 may reflect differential expression patterns or levels of the enzymes. Furthermore, single knock-out mice of either TPST-1 or -2 did not phenocopy mice with double-knockout of both TPSTs, suggesting that the functions of the TPSTs are at least partially redundant, which points to the functional importance of these enzymes in the retina

    The YH database: the first Asian diploid genome database

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    The YH database is a server that allows the user to easily browse and download data from the first Asian diploid genome. The aim of this platform is to facilitate the study of this Asian genome and to enable improved organization and presentation large-scale personal genome data. Powered by GBrowse, we illustrate here the genome sequences, SNPs, and sequencing reads in the MapView. The relationships between phenotype and genotype can be searched by location, dbSNP ID, HGMD ID, gene symbol and disease name. A BLAST web service is also provided for the purpose of aligning query sequence against YH genome consensus. The YH database is currently one of the three personal genome database, organizing the original data and analysis results in a user-friendly interface, which is an endeavor to achieve fundamental goals for establishing personal medicine. The database is available at http://yh.genomics.org.cn

    Polymorphisms in the Taste Receptor Gene (Tas1r3) Region are Associated with Saccharin Preference in 30 Mouse Strains.

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    The results of recent studies suggest that the mouse Sac (saccharin preference) locus is identical to the Tas1r3 (taste receptor) gene. The goal of this study was to identify Tas1r3 sequence variants associated with saccharin preference in a large number of inbred mouse strains. Initially, we sequenced approximately 6.7 kb of the Tas1r3 gene and its flanking regions from six inbred mouse strains with high and low saccharin preference, including the strains in which the Sac alleles were described originally (C57BL/6J, Sac(b); DBA/2J, Sac(d)). Of the 89 sequence variants detected among these six strains, eight polymorphic sites were significantly associated with preferences for 1.6 mm saccharin. Next, each of these eight variant sites were genotyped in 24 additional mouse strains. Analysis of the genotype-phenotype associations in all 30 strains showed the strongest association with saccharin preference at three sites: nucleotide (nt) -791 (3 bp insertion/deletion), nt +135 (Ser45Ser), and nt +179 (Ile60Thr). We measured Tas1r3 gene expression, transcript size, and T1R3 immunoreactivity in the taste tissue of two inbred mouse strains with different Tas1r3 haplotypes and saccharin preferences. The results of these experiments suggest that the polymorphisms associated with saccharin preference do not act by blocking gene expression, changing alternative splicing, or interfering with protein translation in taste tissue. The amino acid substitution (Ile60Thr) may influence the ability of the protein to form dimers or bind sweeteners. Here, we present data for future studies directed to experimentally confirm the function of these polymorphisms and highlight some of the difficulties of identifying specific DNA sequence variants that underlie quantitative trait loci
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