Starkgarrison1008

Transforming growth factor (TGF)β/activin superfamily regulates diverse biological processes including germ layer specification and axis patterning in vertebrates. TGFβ/activin leads to phosphorylation of Smad2 and Smad3, followed by regulation of their target genes. Activin treatment also induces the essential organizer gene chordin (chrd). The involvement of Smad2/3 in chrd expression has been unclear as to whether Smad2/3 involvement is direct or indirect and whether any cis-acting response elements for Smad2/3 are present in the proximal or distal regions of its promoter. In the present study, we isolated the -2250 bps portion of the chrd promoter, showing that it contained Smad2/3 direct binding sites at its distal portion, separate from the proximal locations of other organizer genes, goosecoid and cerberus. The pattern of transcription activation for the promoter (-2250 bps) was indistinguishable from that of the endogenous chrd in gastrula Xenopus embryos. N-acetylcysteine Reporter gene assays and site-directed mutagenesis analysis of the chrd promoter mapped two active activin/Smad response elements (ARE1 and ARE2) for Smad2 and Smad3. For a differential chrd induction, Smad2 acted on both ARE1 and ARE2, but Smad3 was only active for ARE2. Collectively, the results demonstrate that the distal region of chrd promoter contains the direct binding cis-acting elements for Smad2 and Smad3, which differentially modulate chrd transcription in gastrula Xenopus embryos.Chronic infection with hepatitis B virus (HBV) is a major risk factor for the development of hepatocellular carcinoma (HCC). The HBV encoded oncoprotein, HBx, alters the expression of host genes and the activity of multiple signal transduction pathways that contribute to the pathogenesis of HCC by multiple mechanisms independent of HBV replication. However, it is not clear which pathways are the most relevant therapeutic targets in hepatocarcinogenesis. Short chain fatty acids (SCFAs) have strong anti-inflammatory and anti-neoplastic properties, suggesting that they may block the progression of chronic liver disease (CLD) to HCC, thereby identifying the mechanisms relevant to HCC development. This hypothesis was tested in HBx transgenic (HBxTg) mice fed SCFAs. Groups of HBxTg mice were fed with SCFAs or vehicle from 6 to 9 months of age and then assessed for dysplasia, and from 9 to 12 months of age and then assessed for HCC. Livers from 12 month old mice were then analyzed for changes in gene expression by mass spectrometry-based proteomics. SCFA-fed mice had significantly fewer dysplastic and HCC nodules compared to controls at 9 and 12 months, respectively. Pathway analysis of SCFA-fed mice showed down-regulation of signaling pathways altered by HBx in human CLD and HCC, including those involved in inflammation, phosphatidylinositol 3-kinase, epidermal growth factor, and Ras. SCFA treatment promoted increased expression of the tumor suppressor, disabled homolog 2 (DAB2). DAB2 depresses Ras pathway activity, which is constitutively activated by HBx. SCFAs also reduced cell viability in HBx-transfected cell lines in a dose-dependent manner while the viability of primary human hepatocytes was unaffected. These unique findings demonstrate that SCFAs delay the pathogenesis of CLD and development of HCC, and provide insight into some of the underlying mechanisms that are relevant to pathogenesis in that they are responsive to treatment.Lysine-specific demethylase 1 (LSD1) is a FAD-dependent enzyme, which has been proposed as a promising target for therapeutic cancer. Herein, a series of benzofuran derivatives were designed, synthesized and biochemical evaluated as novel LSD1 inhibitors based on scaffold hopping and conformational restriction strategy. Most of the compounds potently suppressed the enzymatic activities of LSD1 and potently inhibited tumor cells proliferation. In particular, the representative compound 17i exhibited excellent LSD1 inhibition at the molecular levels with IC50 = 0.065 μM, as well as anti-proliferation against MCF-7, MGC-803, H460, A549 and THP-1 tumor cells with IC50 values of 2.90 ± 0.32, 5.85 ± 0.35, 2.06 ± 0.27, 5.74 ± 1.03 and 6.15 ± 0.49 μM, respectively. The binding modes of these compounds were rationalized by molecular docking. Meanwhile, a preliminary druggability evaluation showed that compound 17i displayed favorable liver microsomal stability and weak inhibitory activity against CYPs at 10 μM. Remarkably, H460 xenograft tumors studies revealed that 17i demonstrated robust in vivo antitumor efficacy without significant side effects. All the results demonstrated that compound 17i could represent a promising lead for further development.The lantibiotic nisin, usually used as a 2.5%w/w in NaCl and milk solids, has activity against a wide range of Gram-positive bacteria, especially food-borne pathogens, and has been used as a food preservative for decades without the development of significant resistance. It has been reported that the high purity (>95%) nisin Z form has activity against the Gram-negative speciesE. coli, which is significantly reduced in the presence of NaCl. This current study examined, by1H NMR spectroscopy, the effects of NaCl, and a range of other salts, on the observed aqueous solution1H NMR spectra of nisin Z in the pH 3-4 range, where nisin Z has its maximum stability. Nisin's mechanism of action involves binding to the polyoxygenated pyrophosphate moiety of lipid II, and in acidic solution the positively charged C-terminus region is reported to interact with the negative sulfate groups of SDS micelles, so the study was extended to include a number of polyoxygenated anions commonly used as buffers in many biological assays. In general, the biggest changes found were in the chemical shifts of protons in the hydrophobic N-terminus region, rather than the more polar C-terminus region. The effects seen on the addition of the salts (cations and anions) were not just an overall non-specific ionic strength effect, as different salts caused different effects, in an unpredictive manner. Similarly, the polyoxygenated anions behaved differently and not predictably, and neither the cations/anions, or polyoxygenated anions, constitute a Hofmeister or inverse Hofmeister series.Two influential enzymological theories were proposed in the late 1970s - that catalytic power stems only from transition state stabilization, while ground state interactions are either irrelevant or inhibitory; and enzyme substrate binding is nonspontaneous at low substrate concentrations ([S]0  less then less then Km). I show here that ground state destabilization can be a very effective source of catalytic power, especially at high substrate concentrations, and enzyme-substrate binding thermodynamics are independent of initial substrate concentration. Binding free energy ranges from negative (spontaneous) under pre-steady state conditions up to a maximum of zero at steady state. Nonspontaneous binding can only occur under standard state conditions when c° is defined to be less than Km.The black tea could be stored for a long time, and subsequently affects the flavor characteristics. In the present study, the effects of storage years (1, 2, 3, 4, 5, 10, 17 and 20 years) on the chemical profiling and taste quality of keemun black tea (KBT) were compared by metabolomics and quantitative sensory evaluation. The main polyphenols were degraded during the storing, especially 10-year storage, but caffeine and theobromine were stable. The intensity of bitterness, astringency, umami was negatively correlated to storage years, with correlation coefficient at -0.95, -0.91 and -0.83 respectively, whereas sweetness had positive correlation coefficient at 0.74. Quinic acid, galloylated catechins, linolenic acid, linoleic acid, malic acid, palamitic acid, and theaflavin-3́-gallate were marker compounds which were responsible for distinguishing short and long time preserved KBT. The contents of fatty acids were positively correlated to storage time and sweet intensity.Performances of multiresidue analysis of one hundred of pesticides and contaminants, using GC-Q-Orbitrap method in full scan mode were compared to those obtained with GC-triple-quadrupole method in multiple reaction monitoring mode. In terms of sensitivity, 86% of molecules exhibited lower limit of detection values using GC-Q-Orbitrap than using GC-triple-quadrupole. For the GC-Q-Orbitrap method, more than 85% of the pesticides and contaminants showed good recovery [70-120%] in wheat samples, with relative standard deviation values less then 20%. GC-Q-Orbitrap method appeared the most sensitive for most pesticides studied in wheat with limit of quantification values ranged between 0.1 µg/kg and 4 µg/kg. Moreover, the matrix effect was acceptable in wheat extracts for 84 molecules but strong suppression of the chromatographic signal was observed for 16 molecules for the GC-Q-Orbitrap method. The injection of unpurified wheat extracts spiked at 10 µg/kg proved the potential of the GC-Q-Orbitrap method for use in performing high-throughput pesticide screening.The interaction between lipase and quercetin 3-rhamnoside was studied by fluorescence spectroscopy, enzyme kinetics, and molecular dynamics simulation. The results showed that quercetin 3-rhamnoside had a strong quenching effect on the intrinsic fluorescence of lipase. The binding constant decreased with increasing temperature, and the number of binding sites approached 1. Thermodynamic parameters indicated that hydrogen bonding and van der Waals forces are the dominant forces when the interaction occurs. Circular dichroism spectroscopy and infrared spectroscopy proved that the ligand perturbed the structure of lipase. Enzyme kinetics results showed that quercetin 3-rhamnoside inhibited lipase, and the inhibitory effect was dose-dependent. Molecular dynamics simulation further explained the interaction mechanism and inhibitory effect. This study confirmed the inhibitory effect of quercetin 3-rhamnoside on lipase explained their binding mechanism, which will contribute to guiding the development of fat-reducing functional foods.In this study, we developed a lateral flow immunoassay (LFIA) for the detection of pork additives in meat products. LFIA of porcine immunoglobulins (IgG) as a molecular biomarker was carried out in a sandwich format for species identification. Gold nanoparticles as a nano-dispersed label were conjugated to secondary antibodies specific to anti-porcine IgG. The test system was characterized by high specificity, which was confirmed by the absence of cross-reactivity with any other species tested. A short technique of sample preparation was proposed aimed at the effective extraction of IgG from meat samples. The developed LFIA enabled the detection of a pork ingredient at a level as low as 0.063% (w/w) in raw meat within 35 min including sample preparation. A large panel of real meat samples was analyzed by the LFIA. The results showed that porcine IgG can be reliably recognized both in raw meat products and processed meat foodstuffs.The effects of different fertilisation treatments with arbuscular mycorrhizal fungi (AMF) inoculation on AMF root colonisation, fruit yield, nutrient and total phenol contents, volatile compound composition, and sensory attributes of tomato (Solanum lycopersicum L.) were investigated. Mineral, organic, and mineral + organic fertiliser application positively affected tomato yield (35%-50%) and phosphorus concentration (24%-29%) compared with controls. AMF application had a significant impact on the total nitrogen (+9%), manganese (+12%), and hydrophilic phenol (+8%) contents in the fruit. Volatile compounds were affected by the interactive effects of fertilisation and AMF application. The response of tomato fruit sensory quality indicators was relatively modest, with only a few sensory characteristics affected to a lesser extent. Although tomato showed susceptibility to field-native AMF, particular combinations of fertilisation and AMF inoculation were more effective at improving the quality parameters of tomatoes under field conditions applied in this study.