-
G3 (Bethesda, Md.) Nov 2017We have previously identified () mutations that resulted in maize kernels containing abnormal embryos with normal-appearing endosperm among the progeny of active...
We have previously identified () mutations that resulted in maize kernels containing abnormal embryos with normal-appearing endosperm among the progeny of active Robertson's stocks. Our rationale for the mutant screen described here is that it should be possible to produce ethyl methane sulfonate (EMS)-induced mutations at a frequency higher than that obtained by transposon mutagenesis and with greater ease. This proved to be the case when we screened for mutations that are embryo-specific among progeny of materials generated with EMS-treated pollen. The EMS-induced mutation frequency reported here is nearly three times the 4.5% we obtained with the transposable element stocks. The 45 mutants reported here were all tested for germination capacity and nearly all were lethal. The embryo phenotypes of 34 mutations were examined by dissection of the mature embryos. All were found to be retarded in development and morphologically abnormal. Half of the mutants in this group were blocked in the proembryo and transition stages. They likely include mutations in nuclear genes coding for plastid proteins. The other 17 are mainly blocked in the coleoptilar stage, or in later stages with a low frequency. This group likely includes mutations in genes regulating the completion of shoot apical meristem (SAM) development and accompanying morphogenetic events. Most of the complementation tests using 19 of the mutations in 35 unique combinations complimented each other, except for two pairs of mutations with similar phenotypes. Our results provide additional evidence for the presence of many loci in the maize genome.
Topics: Chloroplast Proteins; Endosperm; Ethyl Methanesulfonate; Gene Expression Regulation, Developmental; Gene Expression Regulation, Plant; Germination; Mutation; Zea mays
PubMed: 28978631
DOI: 10.1534/g3.117.300293 -
Journal of Chromatography. A Apr 2021A simple and rapid analytical method was developed for determination of four biogenic amines [histamine (Him), cadaverine (Cad), tyramine (Tym), 2-phenylethylamine...
Simple and rapid determination of biogenic amines in fish and fish products by liquid chromatography-tandem mass spectrometry using 2,4,6-triethyl-3,5-dimethyl pyrylium trifluoromethanesulfonate as a derivatization reagent.
A simple and rapid analytical method was developed for determination of four biogenic amines [histamine (Him), cadaverine (Cad), tyramine (Tym), 2-phenylethylamine (Pea)] in fish and fish products. This method uses a new derivatization reagent, 2,4,6-triethyl-3,5-dimethyl pyrylium trifluoromethanesulfonate (Py-Tag). The four biogenic amines in the samples were extracted with trichloroacetic acid. The diluted extract was derivatized with Py-Tag (15 min at 50°C) and then subjected to liquid chromatography-tandem mass spectrometry (LC-MS/MS). The limits of quantification for the method were 2 mg/kg for Him, Tym, and Pea and 10 mg/kg for Cad. The matrix effects derived from the tested fish and fish products were negligible in the LC-MS/MS analysis. The impact of the sample matrices on the Py-Tag derivatization was also negligible. The trueness and repeatability of the method were assessed by performing replicate analyses (n = 5) of five samples of fish and fish products, each spiked with the four biogenic amines at three different concentration levels. Analysis of the samples found 87%-104% of the spiked concentrations and the relative standard deviations were <6.1%. A reference sample and quality control canned fish samples were analyzed by the method, and the concentrations of the Him were within acceptable limits. The developed method was successfully used to determine concentrations of the four biogenic amines in 48 fish and fish products on the Japanese market. The developed method does not require cleanup using a solid-phase extraction column or similar, and the derivatization reaction time was only 15 min. The results suggested that the present method is reliable and suitable for rapid analysis of the four biogenic amines in fish and fish products.
Topics: Animals; Biogenic Amines; Cadaverine; Calibration; Chromatography, Liquid; Fish Products; Fishes; Histamine; Limit of Detection; Mesylates; Phenethylamines; Quality Control; Reference Standards; Tandem Mass Spectrometry; Tyramine
PubMed: 33774435
DOI: 10.1016/j.chroma.2021.462046 -
Bioorganic & Medicinal Chemistry Letters Sep 2017A series of 1-substituted 3-(t-butyl/trifluoromethyl)pyrazole C-region analogues of 2-(3-fluoro-4-methylsulfonamidophenyl)propanamides were investigated for hTRPV1...
A series of 1-substituted 3-(t-butyl/trifluoromethyl)pyrazole C-region analogues of 2-(3-fluoro-4-methylsulfonamidophenyl)propanamides were investigated for hTRPV1 antagonism. The structure activity relationship indicated that the 3-chlorophenyl group at the 1-position of pyrazole was the optimized hydrophobic group for antagonistic potency and the activity was stereospecific to the S-configuration, providing exceptionally potent antagonists 13S and 16S with K=0.1nM. Particularly significant, 13S exhibited antagonism selective for capsaicin and NADA and not for low pH or elevated temperature. Both compounds also proved to be very potent antagonists for rTRPV1, blocking in vivo the hypothermic action of capsaicin, consistent with their in vitro mechanism. The docking study of compounds 13S and 16S in our hTRPV1 homology model indicated that the binding modes differed somewhat, with that of 13S more closely resembling that of GRT12360.
Topics: Dose-Response Relationship, Drug; Humans; Mesylates; Models, Molecular; Molecular Structure; Phenylpropionates; Pyrazoles; Structure-Activity Relationship; TRPV Cation Channels
PubMed: 28838698
DOI: 10.1016/j.bmcl.2017.08.020 -
Molecular Biology of the Cell Mar 2020Cells depend on robust DNA damage recognition and repair systems to maintain genomic integrity for survival in a mutagenic environment. In the pathogenic yeast , a...
Cells depend on robust DNA damage recognition and repair systems to maintain genomic integrity for survival in a mutagenic environment. In the pathogenic yeast , a subset of genes involved in the response to DNA damage-induced genome instability and morphological changes has been found to regulate virulence. To better understand the virulence-linked DNA repair network, we screened for methyl methane sulfonate (MMS) sensitivity within the GRACE conditional expression collection and identified 56 hits. One of these potential DNA damage repair-associated genes, a conditional mutant, unexpectedly had a previously characterized function in cytokinesis. Deletion of resulted in MMS sensitivity and genome instability, suggesting Hof1 acts in the DNA damage response. By probing genetic interactions with distinct DNA repair pathways, we found that Hof1 is genetically linked to the Rad53 pathway. Furthermore, Hof1 is down-regulated in a Rad53-dependent manner and its importance in the MMS response is reduced when Rad53 is overexpressed or when or is deleted. Together, this work expands our understanding of the DNA repair network and uncovers interplay between the cytokinesis regulator Hof1 and the Rad53-mediated checkpoint.
Topics: Candida albicans; Cell Cycle Checkpoints; Cell Nucleus; DNA Damage; Epistasis, Genetic; Fungal Proteins; Genomic Instability; Methyl Methanesulfonate; Models, Biological; Mutation; Protein Domains
PubMed: 31940254
DOI: 10.1091/mbc.E19-06-0316 -
Biochemical and Biophysical Research... Jan 2020Methyl sulfur compounds are a rich source of environmental sulfur for microorganisms, but their use requires redox systems. The bacterial sfn and msu operons contain...
Methyl sulfur compounds are a rich source of environmental sulfur for microorganisms, but their use requires redox systems. The bacterial sfn and msu operons contain two-component flavin-dependent monooxygenases for dimethylsulfone (DMSO) assimilation: SfnG converts DMSO to methanesulfinate (MSI), and MsuD converts methanesulfonate (MS) to sulfite. However, the enzymatic oxidation of MSI to MS has not been demonstrated, and the function of the last enzyme of the msu operon (MsuC) is unresolved. We employed crystallographic and biochemical studies to identify the function of MsuC from Pseudomonas fluorescens. The crystal structure of MsuC adopts the acyl-CoA dehydrogenase fold with putative binding sites for flavin and MSI, and functional assays of MsuC in the presence of its oxidoreductase MsuE, FMN, and NADH confirm the enzymatic generation of MS. These studies reveal that MsuC converts MSI to MS in sulfite biosynthesis from DMSO.
Topics: Acyl-CoA Dehydrogenase; Bacterial Proteins; Binding Sites; Crystallography, X-Ray; Dimerization; Dimethyl Sulfoxide; Flavins; Magnetic Resonance Spectroscopy; Mesylates; Molecular Docking Simulation; Oxidoreductases; Oxygen; Protein Structure, Secondary; Pseudomonas fluorescens; Structure-Activity Relationship; Sulfides; Sulfones; Sulfur; Thiophenes
PubMed: 31753487
DOI: 10.1016/j.bbrc.2019.11.008 -
The Journal of Organic Chemistry Nov 2021We developed an electrochemical trifluoromethylation of thiophenols without the use of metal catalysts and oxidants. This reaction features mild reaction conditions,...
We developed an electrochemical trifluoromethylation of thiophenols without the use of metal catalysts and oxidants. This reaction features mild reaction conditions, readily available substrate, as well as moderate to good yields. In addition, this protocol can be easily scaled up with moderate efficiency.
Topics: Hydrocarbons, Fluorinated; Mesylates; Phenols; Sulfhydryl Compounds
PubMed: 33416327
DOI: 10.1021/acs.joc.0c02659 -
Journal of Biochemical and Molecular... Nov 2018There is a dire need for new treatments for Alzheimer's disease (AD). Principal drugs have reached maturity, and the number of people affected by AD is growing at a... (Comparative Study)
Comparative Study
There is a dire need for new treatments for Alzheimer's disease (AD). Principal drugs have reached maturity, and the number of people affected by AD is growing at a rapid rate. After years of research and many clinical trials, only symptomatic treatments are available. An effective disease-modifying drug for AD needs to be discovered. The research presented in this paper aims to facilitate in the discovery of new potential targets that could help in the ongoing AD research. Aryl methanesulfonate derivatives were screened for their acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activities. IC values between 0.660 and 3.397 µM against AChE and 0.885 and 2.596 µM against BuChE were obtained.
Topics: Acetylcholinesterase; Animals; Butyrylcholinesterase; Cholinesterase Inhibitors; Dithionitrobenzoic Acid; Drug Discovery; Electrophorus; Fish Proteins; Horses; Mesylates; Nerve Tissue Proteins; Nootropic Agents; Osmolar Concentration; Spectrophotometry; Sulfhydryl Reagents
PubMed: 30088833
DOI: 10.1002/jbt.22210 -
Journal of Experimental & Clinical... Nov 2018Ligand-dependent activation of the G-protein coupled receptor 119 (GPR119) lowers blood glucose via glucose-dependent insulin secretion and intestinal glucagon-like...
BACKGROUND
Ligand-dependent activation of the G-protein coupled receptor 119 (GPR119) lowers blood glucose via glucose-dependent insulin secretion and intestinal glucagon-like peptide-1 production. However, the function of GPR119 in cancer cells has not been studied.
METHODS
GPR119 expression was assessed by real-time qPCR and immunohistochemistry in human breast cancer cell lines and breast cancer tissues. Cell proliferation and cell cycle analyses were performed by Incucyte® live cell analysis system and flow cutometry, respectively. Autophagy activity was estimeated by western blottings and LC3-GFP transfection.
RESULTS
mRNA or protein expression of GPR119 was detected in 9 cancer cell lines and 19 tissue samples. Cotreatment with GPR119 agonist (MBX-2982 or GSK1292263) significantly potentiated gefitinib-induced cell growth inhibition in gefitinib-insensitive MCF-7 and MDA-MB-231 breast cancer cells. We observed that caspase-3/7 activity was enhanced with the downregulation of Bcl-2 in MCF-7 cells exposed to MBX-2982. Gefitinib-induced autophagy is related with cancer cell survival and chemoresistance. GPR119 agonists inhibit gefitinib-induced autophagosome formation in MCF-7 and MDA-MB-231 cells. MBX-2982 also caused a metabolic shift to enhanced glycolysis accompanied by reduced mitochondrial oxidative phosphorylation. MBX-2982 increased intracellular (~ 2.5 mM) and extracellular lactate (~ 20 mM) content. Gefitinib-mediated autophagy was suppressed by 20 mM lactate in MCF-7 cells.
CONCLUSIONS
GPR119 agonists reduced mitochondrial OXPHOS and stimulated glycolysis in breast cancer cells, with consequent overproduction of lactate that inhibited autophagosome formation. Because autophagy is crucial for the survival of cancer cells exposed to TKIs, GPR119 agonists potentiated the anticancer effects of TKIs.
Topics: Animals; Autophagy; Breast Neoplasms; Cell Line, Tumor; Drug Synergism; Female; Gefitinib; Humans; Lactic Acid; MCF-7 Cells; Mesylates; Mice, Inbred BALB C; Mice, Nude; Oxadiazoles; Receptors, G-Protein-Coupled; Tetrazoles; Thiazoles; Transfection
PubMed: 30497501
DOI: 10.1186/s13046-018-0949-2 -
International Journal of Antimicrobial... Jun 2022There has been accumulating interest in nebulised colistin methanesulfonate (CMS) for the treatment of ventilator-associated pneumonia (VAP). In this study, pulmonary...
Pulmonary and systemic pharmacokinetics of colistin methanesulfonate (CMS) and formed colistin following nebulisation of CMS among patients with ventilator-associated pneumonia.
There has been accumulating interest in nebulised colistin methanesulfonate (CMS) for the treatment of ventilator-associated pneumonia (VAP). In this study, pulmonary and systemic pharmacokinetics following nebulisation of CMS at a dose of 3 MIU and 5 MIU, using a vibrating mesh nebuliser, for VAP caused by extensively drug-resistant Gram-negative pathogens was assessed. Blood samples and mini-bronchoalveolar lavage (mini-BAL) was performed post-dose at 1, 4 and 8 h. Concentrations of CMS and formed colistin in mini-BAL and plasma were determined by liquid chromatography-tandem mass spectrometry, and pharmacokinetic analysis was conducted using a population approach. The study population included three groups (n = 10 per group): (A) intravenous CMS and concomitantly nebulised CMS at a dose of 3 MIU (30 min duration); (B) nebulised CMS at a dose of 3 MIU (30 min duration) as monotherapy; and (C) nebulised CMS 5 MIU (45 min duration) as monotherapy. Mean plasma formed colistin concentrations were <1 mg/L following CMS nebulisation as monotherapy (groups B and C). Predicted trough concentrations of formed colistin in the epithelial lining fluid (ELF) following 24-h dosing of 3 MIU and 5 MIU nebulised CMS were 120.4 mg/L and 200.7 mg/L, respectively. The model predicted that concomitant intravenous CMS (group A) had minimal impact on the formed colistin concentration in ELF. This study demonstrated high ELF formed colistin concentrations following nebulised CMS (constantly above colistin MICs), while plasma concentrations were lower than those associated with nephrotoxicity. Our results provide important information for optimisation of nebulised colistin therapy.
Topics: Anti-Bacterial Agents; Colistin; Humans; Lung; Mesylates; Pneumonia, Ventilator-Associated
PubMed: 35405269
DOI: 10.1016/j.ijantimicag.2022.106588 -
Drug Delivery Dec 2022The goal of this work was to improve the aqueous solubility and dissolution rate of eprosartan mesylate by preparing inclusion complex of drug with β-cyclodextrin...
The goal of this work was to improve the aqueous solubility and dissolution rate of eprosartan mesylate by preparing inclusion complex of drug with β-cyclodextrin (β-CD) by microwave technique. In order to determine the solubility of eprosartan, phase solubility was determined and dissolution study was also conducted. Further, analytical techniques for instance, particle size distribution, differential scanning calorimetry, powder X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy were used for the characterization of inclusion complex. In addition, the binding pattern of eprosartan with the β-CD was investigated by molecular modeling study. Phase solubility study revealed that approximately 4.48 folds improvement in the solubility of drug was noted with β-CD (10 mM). The estimated stability constant () values for eprosartan:β-CD binary mixture was found to be 280.78 M. The prepared inclusion complex of drug with β-CD presented better drug release profile (62.96 ± 2.01% in 1 h) as compared to their physical mixture (41.41 ± 1.77% in 1 h) or drug per se (29.97 ± 3.13%). The inclusion complex demonstrated different features and properties from pure drug, and we inferred that this could be due to the inclusion of drug into cyclodextrin cavity that confirmed by different analytical method. Molecular modeling study demonstrated a good affinity of eprosartan to entangle to β-CD. The outcomes have shown that guest molecule has many significant interactions with the host molecule. These observations are very interesting and may be a valuable approach to improve the solubility and in turn the bioavailability of eprosartan.
Topics: Acrylates; Calorimetry, Differential Scanning; Imidazoles; Mesylates; Microwaves; Solubility; Spectroscopy, Fourier Transform Infrared; Technology; Thiophenes; X-Ray Diffraction; beta-Cyclodextrins
PubMed: 35549506
DOI: 10.1080/10717544.2022.2072540