Chemical basis for the phytotoxicity of N-aryl hydroxamic acids and acetanilide analogues.

PubMed

Bravo, Héctor R; Villarroel, Elisa; Copaja, Sylvia V; Argandoña, Victor H

2008-01-01

Germination inhibition activity of N-aryl hydroxamic acids and acetanilide analogues was measured on lettuce seeds (Lactuca sativa). Lipophilicity of the compounds was determined by HPLC. A correlation between lipophilicity values and percentage of germination inhibition was established. A model mechanism of action for auxin was used for analyzing the effect of the substituent at the alpha carbon atom (Ca) on the polarization of hydroxamic and amide functions in relation to the germination inhibition activity observed. Results suggest that the lipophilic and acidic properties play an important role in the phytotoxicity of the compounds. A test with the microalga Chlorella vulgaris was used to evaluate the potential herbicide activity of the hydroxamic acids and acetanilides.

Metabolic changes in rat serum after administration of suberoylanilide hydroxamic acid and discriminated by SVM.

PubMed

Yu, J; Wu, H; Lin, Z; Su, K; Zhang, J; Sun, F; Wang, X; Wen, C; Cao, H; Hu, L

2017-12-01

Suberoylanilide hydroxamic acid (SAHA) exerts marked anticancer effects via promotion of apoptosis, cell cycle arrest, and prevention of oncogene expression. In this study, serum metabolomics and artificial intelligence recognition were used to investigate SAHA toxicity. Forty rats (220 ± 20 g) were randomly divided into control and three SAHA groups (low, medium, and high); the experimental groups were treated with 12.3, 24.5, or 49.0 mg kg -1 SAHA once a day via intragastric administration. After 7 days, blood samples from the four groups were collected and analyzed by gas chromatography-mass spectrometry, and pathological changes in the liver were examined using microscopy. The results showed that increased levels of urea, oleic acid, and glutaconic acid were the most significant indicators of toxicity. Octadecanoic acid, pentadecanoic acid, glycerol, propanoic acid, and uric acid levels were lower in the high SAHA group. Microscopic observation revealed no obvious damage to the liver. Based on these data, a support vector machine (SVM) discrimination model was established that recognized the metabolic changes in the three SAHA groups and the control group with 100% accuracy. In conclusion, the main toxicity caused by SAHA was due to excessive metabolism of saturated fatty acids, which could be recognized by an SVM model.

Potent histone deacetylase inhibitors built from trichostatin A and cyclic tetrapeptide antibiotics including trapoxin

PubMed Central

Furumai, Ryohei; Komatsu, Yasuhiko; Nishino, Norikazu; Khochbin, Saadi; Yoshida, Minoru; Horinouchi, Sueharu

2001-01-01

Trichostatin A (TSA) and trapoxin (TPX) are potent inhibitors of histone deacetylases (HDACs). TSA is proposed to block the catalytic reaction by chelating a zinc ion in the active-site pocket through its hydroxamic acid group. On the other hand, the epoxyketone is suggested to be the functional group of TPX capable of alkylating the enzyme. We synthesized a novel TPX analogue containing a hydroxamic acid instead of the epoxyketone. The hybrid compound cyclic hydroxamic acid-containing peptide (CHAP) 1 inhibited HDAC1 at low nanomolar concentrations. The HDAC1 inhibition by CHAP1 was reversible as it was by TSA, in contrast to the irreversible inhibition by TPX. CHAP with an aliphatic chain length of five, which corresponded to that of acetylated lysine, was stronger than those with other lengths. These results suggest that TPX is a substrate mimic and that the replacement of the epoxyketone with the hydroxamic acid converted TPX to an inhibitor chelating the zinc like TSA. Interestingly, HDAC6, but not HDAC1 or HDAC4, was resistant to TPX and CHAP1, whereas TSA inhibited these HDACs to a similar extent. HDAC6 inhibition by TPX at a high concentration was reversible, probably because HDAC6 is not alkylated by TPX. We further synthesized the counterparts of all known naturally occurring cyclic tetrapeptides containing the epoxyketone. HDAC1 was highly sensitive to all these CHAPs much more than HDAC6, indicating that the structure of the cyclic tetrapeptide framework affects the target enzyme specificity. These results suggest that CHAP is a unique lead to develop isoform-specific HDAC inhibitors. PMID:11134513

Hydroxamic acid content and toxicity of rye at selected growth stages.

PubMed

Rice, Clifford P; Park, Yong Bong; Adam, Frédérick; Abdul-Baki, Aref A; Teasdale, John R

2005-08-01

Rye (Secale cereale L.) is an important cover crop that provides many benefits to cropping systems including weed and pest suppression resulting from allelopathic substances. Hydroxamic acids have been identified as allelopathic compounds in rye. This research was conducted to improve the methodology for quantifying hydroxamic acids and to determine the relationship between hydroxamic acid content and phytotoxicity of extracts of rye root and shoot tissue harvested at selected growth stages. Detection limits for an LC/MS-MS method for analysis of hydroxamic acids from crude aqueous extracts were better than have been reported previously. (2R)-2-beta-D-Glucopyranosyloxy-4-hydroxy-(2H)-1,4-benzoxazin-3(4H)-one (DIBOA-G), 2,4-dihydroxy-(2H)-1,4-benzoxazin-3(4H)-one (DIBOA), benzoxazolin-2(3H)-one (BOA), and the methoxy-substituted form of these compounds, (2R)-2-beta-D-glucopyranosyloxy-4-hydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one (DIMBOA glucose), 2,4-hydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one (DIMBOA), and 6-methoxy-benzoxazolin-2(3H)-one (MBOA), were all detected in rye tissue. DIBOA and BOA were prevalent in shoot tissue, whereas the methoxy-substituted compounds, DIMBOA glucose and MBOA, were prevalent in root tissue. Total hydroxamic acid concentration in rye tissue generally declined with age. Aqueous crude extracts of rye shoot tissue were more toxic than extracts of root tissue to lettuce (Lactuca sativa L.) and tomato (Lycopersicon esculentum Mill.) root length. Extracts of rye seedlings (Feekes growth stage 2) were most phytotoxic, but there was no pattern to the phytotoxicity of extracts of rye sampled at growth stages 4 to 10.5.4, and no correlation of hydroxamic acid content and phytotoxicity (I50 values). Analysis of dose-response model slope coefficients indicated a lack of parallelism among models for rye extracts from different growth stages, suggesting that phytotoxicity may be attributed to compounds with different modes of action at different stages. Hydroxamic acids may account for the phytoxicity of extracts derived from rye at early growth stages, but other compounds are probably responsible in later growth stages.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neu, Mary Patricia

The coordination chemistry and solution behavior of the toxic ions lead(II) and plutonium(IV, V, VI) have been investigated. The ligand pK as and ligand-lead(II) stability constants of one hydroxamic acid and four thiohydroaxamic acids were determined. Solution thermodynamic results indicate that thiohydroxamic acids are more acidic and slightly better lead chelators than hydroxamates, e.g., N-methylthioaceto-hydroxamic acid, pK a = 5.94, logβ 120 = 10.92; acetohydroxamic acid, pK a = 9.34, logβ 120 = 9.52. The syntheses of lead complexes of two bulky hydroxamate ligands are presented. The X-ray crystal structures show the lead hydroxamates are di-bridged dimers with irregular five-coordinatemore » geometry about the metal atom and a stereochemically active lone pair of electrons. Molecular orbital calculations of a lead hydroxamate and a highly symmetric pseudo octahedral lead complex were performed. The thermodynamic stability of plutonium(IV) complexes of the siderophore, desferrioxamine B (DFO), and two octadentate derivatives of DFO were investigated using competition spectrophotometric titrations. The stability constant measured for the plutonium(IV) complex of DFO-methylterephthalamide is logβ 120 = 41.7. The solubility limited speciation of 242Pu as a function of time in near neutral carbonate solution was measured. Individual solutions of plutonium in a single oxidation state were added to individual solutions at pH = 6.0, T = 30.0, 1.93 mM dissolved carbonate, and sampled over intervals up to 150 days. Plutonium solubility was measured, and speciation was investigated using laser photoacoustic spectroscopy and chemical methods.« less

3-Hydroxypyridin-2-thione as novel zinc binding group for selective histone deacetylase inhibition.

PubMed

Patil, Vishal; Sodji, Quaovi H; Kornacki, James R; Mrksich, Milan; Oyelere, Adegboyega K

2013-05-09

Small molecules bearing hydroxamic acid as the zinc binding group (ZBG) have been the most effective histone deacetylase inhibitors (HDACi) to date. However, concerns about the pharmacokinetic liabilities of the hydroxamic acid moiety have stimulated research efforts aimed at finding alternative nonhydroxamate ZBGs. We have identified 3-hydroxypyridin-2-thione (3-HPT) as a novel ZBG that is compatible with HDAC inhibition. 3-HPT inhibits HDAC 6 and HDAC 8 with an IC50 of 681 and 3675 nM, respectively. Remarkably, 3-HPT gives no inhibition of HDAC 1. Subsequent optimization led to several novel 3HPT-based HDACi that are selective for HDAC 6 and HDAC 8. Furthermore, a subset of these inhibitors induces apoptosis in various cancer cell lines.

Design and synthesis of aryl ether and sulfone hydroxamic acids as potent histone deacetylase (HDAC) inhibitors.

PubMed

Pabba, Chittari; Gregg, Brian T; Kitchen, Douglas B; Chen, Zhen Jia; Judkins, Angela

2011-01-01

A series of novel hydroxamic acid based histone deacetylases (HDAC) inhibitors with aryl ether and aryl sulfone residues at the terminus of a substituted, unsaturated 5-carbon spacer moiety have been synthesized for the first time and evaluated. Compounds with meta- and para-substitution on the aryl ring of ether hydroxamic acids 19c, 20c, 19e, 19f and 19g are potent HDAC inhibitors with activities at low nanomolar levels. Copyright © 2010 Elsevier Ltd. All rights reserved.

Multimodal HDAC Inhibitors with Improved Anticancer Activity.

PubMed

Schobert, Rainer; Biersack, Bernhard

2018-01-01

Histone deacetylases (HDACs) play a significant role in the proliferation and dissemination of cancer and represent promising epigenetic drug targets. The HDAC inhibitor vorinostat featuring a zinc-binding hydroxamate fragment was already clinically approved. However, HDAC inhibitors containing hydroxamic acids are often hampered by acquired or intrinsic drug resistance and may lead to enhanced tumor aggressiveness. In order to overcome these drawbacks of hydroxamate HDAC inhibitors, a series of multimodal derivatives of this compound class, including such with different zinc-binding groups, was recently developed and showed promising anticancer activity. This review provides an overview of the chemistry and pleiotropic anticancer modes of action of these conceptually new HDAC inhibitors. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Chiral mercaptoacetamides display enantioselective inhibition of histone deacetylase 6 and exhibit neuroprotection in cortical neuron models of oxidative stress.

PubMed

Kalin, Jay H; Zhang, Hankun; Gaudrel-Grosay, Sophie; Vistoli, Giulio; Kozikowski, Alan P

2012-03-05

Mercaptoacetamide-based ligands have been designed as a new class of histone deacetylase (HDAC) inhibitors for possible use in the treatment of neurodegenerative diseases. The thiol group of these compounds provides a key binding element for interaction with the catalytic zinc ion, and thus differs from the more typically employed hydroxamic acid based zinc binding groups. Herein we disclose the chemistry and biology of some substituted mercaptoacetamides with the intention of increasing HDAC6 isoform selectivity while maintaining potency similar to their hydroxamic acid analogues. The introduction of a stereocenter α to the thiol group was found to have a considerable impact on HDAC inhibitor potency. These new compounds were also profiled for their therapeutic potential in an in vitro model of stress-induced neuronal injury and were found to act as nontoxic neuroprotective agents. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tabun scavengers based on hydroxamic acid containing cyclodextrins.

PubMed

Brandhuber, Florian; Zengerle, Michael; Porwol, Luzian; Bierwisch, Anne; Koller, Marianne; Reiter, Georg; Worek, Franz; Kubik, Stefan

2013-04-28

Arrangement of several hydroxamic acid-derived substituents along the cavity of a cyclodextrin ring leads to compounds that detoxify tabun in TRIS-HCl buffer at physiological pH and 37.0 °C with half-times as low as 3 min.

Benzyl and Methyl Fatty Hydroxamic Acids Based on Palm Kernel Oil as Chelating Agent for Liquid-Liquid Iron(III) Extraction

PubMed Central

Haron, Md Jelas; Jahangirian, Hossein; Silong, Sidik; Yusof, Nor Azah; Kassim, Anuar; Rafiee-Moghaddam, Roshanak; Mahdavi, Behnam; Peyda, Mazyar; Abdollahi, Yadollah; Amin, Jamileh

2012-01-01

Liquid-liquid iron(III) extraction was investigated using benzyl fatty hydroxamic acids (BFHAs) and methyl fatty hydroxamic acids (MFHAs) as chelating agents through the formation of iron(III) methyl fatty hydroxamate (Fe-MFHs) or iron(III) benzyl fatty hydroxamate (Fe-BFHs) in the organic phase. The results obtained under optimized conditions, showed that the chelating agents in hexane extract iron(III) at pH 1.9 were realized effectively with a high percentage of extraction (97.2% and 98.1% for MFHAs and BFHAs, respectively). The presence of a large amount of Mg(II), Ni(II), Al(III), Mn(II) and Co(II) ions did affect the iron(III) extraction. Finally stripping studies for recovering iron(III) from organic phase (Fe-MFHs or Fe-BFHs dissolved in hexane) were carried out at various concentrations of HCl, HNO3 and H2SO4. The results showed that the desired acid for recovery of iron(III) was 5 M HCl and quantitative recovery of iron(III) was achieved from Fe(III)-MFHs and Fe(III)-BFHs solutions in hexane containing 5 mg/L of Fe(III). PMID:22408444

Synthesis and structure-activity relationship of histone deacetylase (HDAC) inhibitors with triazole-linked cap group.

PubMed

Chen, Po C; Patil, Vishal; Guerrant, William; Green, Patience; Oyelere, Adegboyega K

2008-05-01

Histone deacetylase (HDAC) inhibition is a recent, clinically validated therapeutic strategy for cancer treatment. Small molecule HDAC inhibitors identified so far fall in to three distinct structural motifs: the zinc-binding group (ZBG), a hydrophobic linker, and a recognition cap group. Here we report the suitability of a 1,2,3-triazole ring as a surface recognition cap group-linking moiety in suberoylanilide hydroxamic acid-like (SAHA-like) HDAC inhibitors. Using "click" chemistry (Huisgen cycloaddition reaction), several triazole-linked SAHA-like hydroxamates were synthesized. Structure-activity relationship revealed that the position of the triazole moiety as well as the identity of the cap group markedly affected the in vitro HDAC inhibition and cell growth inhibitory activities of this class of compounds.

Zinc binding in HDAC inhibitors: a DFT study.

PubMed

Wang, Difei; Helquist, Paul; Wiest, Olaf

2007-07-06

Histone deacetylases (HDACs) are attractive targets for the treatment of cancers and a variety of other diseases. Most currently studied HDAC inhibitors contain hydroxamic acids, which are potentially problematic in the development of practical drugs. DFT calculations of the binding modes and free energies of binding for a variety of other functionalities in a model active site of HDAC are described. The protonation state of hydroxamic acids in the active site and the origin of the high affinity are discussed. These results emphasize the importance of a carefully chosen pKa for zinc binding and provide guidance for the design of novel, non-hydroxamic acid HDAC inhibitors.

Investigation on the ZBG-functionality of phenyl-4-yl-acrylohydroxamic acid derivatives as histone deacetylase inhibitors.

PubMed

Musso, Loana; Cincinelli, Raffaella; Zuco, Valentina; Zunino, Franco; Nurisso, Alessandra; Cuendet, Muriel; Giannini, Giuseppe; Vesci, Loredana; Pisano, Claudio; Dallavalle, Sabrina

2015-10-15

A series of alternative Zn-binding groups were explored in the design of phenyl-4-yl-acrylohydroxamic acid derivatives as histone deacetylase (HDAC) inhibitors. Most of the synthesized compounds were less effective than the parent hydroxamic acid. However, the profile of activity shown by the analog bearing a hydroxyurea head group, makes this derivative promising for further investigation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Exploring alternative Zn-binding groups in the design of HDAC inhibitors: squaric acid, N-hydroxyurea, and oxazoline analogues of SAHA.

PubMed

Hanessian, Stephen; Vinci, Valerio; Auzzas, Luciana; Marzi, Mauro; Giannini, Giuseppe

2006-09-15

Analogues of suberoylanilide hydroxamic acid (SAHA) were prepared by replacing the Zn-binding group with squaric acid, N-hydroxyurea, and 4-hydroxymethyl oxazoline units, also varying the length of the aliphatic chain. No inhibitory activity on HDAC was observed below 1.0 microM and no cytotoxic activity on different tumor cell lines was seen below 20.0 microM.

Potent, selective, orally bioavailable inhibitors of tumor necrosis factor-alpha converting enzyme (TACE): discovery of indole, benzofuran, imidazopyridine and pyrazolopyridine P1' substituents.

PubMed

Lu, Zhonghui; Ott, Gregory R; Anand, Rajan; Liu, Rui-Qin; Covington, Maryanne B; Vaddi, Krishna; Qian, Mingxin; Newton, Robert C; Christ, David D; Trzaskos, James; Duan, James J-W

2008-03-15

Potent and selective inhibitors of tumor necrosis factor-alpha converting enzyme (TACE) were discovered with several new heterocyclic P1' groups in conjunction with cyclic beta-amino hydroxamic acid scaffolds. Among them, the pyrazolopyridine provided the best overall profile when combined with tetrahydropyran beta-amino hydroxamic acid scaffold. Specifically, inhibitor 49 showed IC(50) value of 1 nM against porcine TACE and 170 nM in the suppression of LPS-induced TNF-alpha of human whole blood. Compound 49 also displayed excellent selectivity over a wide panel of MMPs as well as excellent oral bioavailability (F%>90%) in rat n-in-1 PK studies.

Hyaluronic acid based hydroxamate and conjugates with biologically active amines: In vitro effect on matrix metalloproteinase-2.

PubMed

Ponedel'kina, Irina Yu; Gaskarova, Aigul R; Khaybrakhmanova, Elvira A; Lukina, Elena S; Odinokov, Victor N

2016-06-25

In this study, water soluble hyaluronic acid (HA) based hydroxamate and conjugates with biologically active amines and hydrazides such as p- and o-aminophenols, anthranilic, 4- and 5-aminosalicylic acids, nicotinic, N-benzylnicotinic and isonicotinic hydrazides, p-aminobenzenesulfonamide (Streptocide), p-aminobenzoic acid diethylaminoethyl ester (Procaine), and 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one (4-aminoantipyrene) were examined as matrix metalloproteinase-2 inhibitors (MMPIs). In a dose of 0.27-270μM, the most efficient MMPIs were HA conjugates with o-aminophenol=4-aminoantipyrine>4-aminosalicylic acid>5-aminosalicylic acid. Conjugates with Streptocide, Procaine and HA hydroxamate showed 40-50% inhibitory effect at all used concentrations. Conjugates with anthranilic acid and isonicotinic hydrazide (Isoniazid) in a dose of 0.27μM inhibited enzyme activity by ∼70%, but with the concentration increase their inhibitory effect was decreased. Copyright © 2016 Elsevier Ltd. All rights reserved.

Zinc chelation with hydroxamate in histone deacetylases modulated by water access to the linker binding channel.

PubMed

Wu, Ruibo; Lu, Zhenyu; Cao, Zexing; Zhang, Yingkai

2011-04-27

It is of significant biological interest and medical importance to develop class- and isoform-selective histone deacetylase (HDAC) modulators. The impact of the linker component on HDAC inhibition specificity has been revealed but is not understood. Using Born-Oppenheimer ab initio QM/MM MD simulations, a state-of-the-art approach to simulating metallo-enzymes, we have found that the hydroxamic acid remains to be protonated upon its binding to HDAC8, and thus disproved the mechanistic hypothesis that the distinct zinc-hydroxamate chelation modes between two HDAC subclasses come from different protonation states of the hydroxamic acid. Instead, our simulations suggest a novel mechanism in which the chelation mode of hydroxamate with the zinc ion in HDACs is modulated by water access to the linker binding channel. This new insight into the interplay between the linker binding and the zinc chelation emphasizes its importance and gives guidance regarding linker design for the development of new class-IIa-specific HDAC inhibitors.

Hydroxamic acid interactions with solvated cerium hydroxides in the flotation of monazite and bastnäsite-Experiments and DFT study

NASA Astrophysics Data System (ADS)

Sarvaramini, A.; Azizi, D.; Larachi, F.

2016-11-01

Density functional theory (DFT) simulations and experiments were performed to clarify the interaction mechanisms between hydroxamic acid collectors and cerium hydroxides during the flotation of bastnäsite and monazite minerals. These minerals showed considerable floatability at moderately alkaline pH which was related to the adsorption of hydroxamic acids on their surfaces as confirmed by vibrational spectroscopic and zeta potential measurements. DFT simulations showed that at moderately alkaline pH, the interactions between solvated Ce(OH)2+ and Ce(OH)2+ and heptyl-hydroxamic acid (HHA) anions resulted in the formation of, respectively, [Ce(OH)(HHA)x(H2O)y]2-x (x[y = ] = 1[6],2[3],3[1]) and [Ce(OH)2(HHA)x(H2O)y]1-x (x[y = ] = 1[5],2[1],3[0]) complexes. The collector anions were found to interact directly through formation of two covalent bonds between their two polar-head oxygen atoms and cerium in the hydroxide complexes. However, formation of such new bonds resulted in breakage of a few covalent/electrostatic bonds between cerium and water molecules initially present in the first hydration shell of the rare-earth metal cation. Building up in the electric double layer of the semi-soluble minerals, these complexes, and by extension, those from other rare-earth elements belonging to monazite and bastnäsite, are speculated to play a role in the interactions between rare-earth minerals and hydroxamic acid collectors.

Nitroreductase-dependent mutagenicity of p-nitrophenylhydroxylamine and its N-acetyl and N-formyl hydroxamic acids.

PubMed

Corbett, M D; Wei, C; Corbett, B R

1985-05-01

p-Nitrophenylhydroxylamine (NPH) and two hydroxamic acids derived from it were synthesized and subjected to mutagenicity testing in Salmonella typhimurium strains TA98, TA98NR, TA1538 and TA1538NR. In addition, p-dinitrobenzene (DNB), p-nitroaniline (NA) and p-nitroacetanilide (AcNA) were simultaneously examined for mutagenic action against these four tester strains. NPH, its N-acetyl (AcNPH) and N-formyl (FoNPH) derivatives, and also DNB displayed strong mutagenic action to the nitroreductase-containing strains, TA98 and TA1538. NPH was the most potent chemical in this series against both of these strains, while the two hydroxamic acids AcNPH and FoNPH, and also DNB displayed approximately the same degree of mutagenicity. In the nitroreductase-deficient strains, TA98NR and TA1538NR, the mutagenicity of these four compounds was markedly reduced. The necessity for nitroreduction in order to activate these promutagens is fairly certain; however, the lack of mutagenicity of NA and AcNA towards all four tester strains made the interpretation of these data somewhat more complicated. Several possible bioactivation pathways were presented, with one mechanism in particular being proposed. This mechanism requires only that the strong electron-withdrawing nitro group be converted to an electron-donating group by bacterial nitroreductase. Such a mechanism is unique for the bioactivation of nitro aromatics by nitroreductase, since the enzymatic reduction need not produce the intermediary hydroxylamine metabolite.

Catalytic Kinetic Resolution of Saturated N-Heterocycles by Enantioselective Amidation with Chiral Hydroxamic Acids.

PubMed

Kreituss, Imants; Bode, Jeffrey W

2016-12-20

The preparation of enantioenriched chiral compounds by kinetic resolution dates back to the laboratories of Louis Pasteur in the middle of the 19th century. Unlike asymmetric synthesis, this process can always deliver enantiopure material (ee > 99%) if the reactions are allowed to proceed to sufficient conversion and the selectivity of the process is not unity (s > 1). One of the most appealing and practical variants is acylative kinetic resolution, which affords easily separable reaction products, and several highly efficient enzymatic and small molecule catalysts are available. Unfortunately, this method is applicable to limited substrate classes such as alcohols and primary benzylamines. This Account focuses on our work in catalytic acylative kinetic resolution of saturated N-heterocycles, a class of molecules that has been notoriously difficult to access via asymmetric synthesis. We document the development of hydroxamic acids as suitable catalysts for enantioselective acylation of amines through relay catalysis. Alongside catalyst optimization and reaction development, we present mechanistic studies and theoretical calculation accounting for the origins of selectivity and revealing the concerted nature of many amide-bond forming reactions. Immobilization of the hydroxamic acid to form a polymer supported reagent allows simplification of the experimental setup, improvement in product purification, and extension of the substrate scope. The kinetic resolutions are operationally straight forward: reactions proceed at room temperature and open to air conditions, without generation of difficult-to-remove side products. This was utilized to achieve decagram scale resolution of antimalarial drug mefloquine to prepare more than 50 g of (+)-erythro-meflqouine (er > 99:1) from the racemate. The immobilized quasienantiomeric acyl hydroxamic acid reagents were also exploited for a rare practical implementation of parallel kinetic resolution that affords both enantiomers of the amine products in high enantiopurity. The success of this process relied on identification of two cleavable acyl groups alongside implementation of flow-chemistry techniques to ensure reusability of the resolving agents. The work discussed in this Account has laid foundations for new catalyst design as well as development of desymmetrization and dynamic kinetic resolution processes. In the meantime, as all the requisite reagents are commercially available, we hope that hydroxamic acid promoted acylative kinetic resolution will become a method of choice for preparation of saturated N-heterocycles in enantiopure form.

Oxidative cycloaddition of hydroxamic acids with dienes or guaiacols mediated by iodine(III) reagents.

PubMed

Shimizu, Hisato; Yoshimura, Akira; Noguchi, Keiichi; Nemykin, Victor N; Zhdankin, Viktor V; Saito, Akio

2018-01-01

[Bis(trifluoroacetoxy)iodo]benzene (BTI) and (diacetoxyiodo)benzene (DIB) efficiently promote the formation of acylnitroso species from hydroxamic acids in the presence of various dienes to give the corresponding hetero-Diels-Alder (HDA) adducts in moderate to high yields. The present method could be applied to the HDA reactions of acylnitroso species with o -benzoquinones generated by the oxidative dearomatization of guaiacols.

Improved production and processing of ⁸⁹Zr using a solution target.

PubMed

Pandey, Mukesh K; Bansal, Aditya; Engelbrecht, Hendrik P; Byrne, John F; Packard, Alan B; DeGrado, Timothy R

2016-01-01

The objectives of the present work were to improve the cyclotron production yield of (89)Zr using a solution target, develop a practical synthesis of the hydroxamate resin used to process the target, and develop a biocompatible medium for (89)Zr elution from the hydroxamate resin. A new solution target (BMLT-2) with enhanced heat dissipation capabilities was designed by using helium-cooled dual foils (0.2 mm Al and 25 μ Havar) and an enhanced water-cooled, elongated solution cavity in the target insert. Irradiations were performed with 14 MeV protons on a 2M solution of yttrium nitrate in 1.25 M nitric acid at 40-μA beam current for 2 h in a closed system. Zirconium-89 was separated from Y by use of a hydroxamate resin. A one-pot synthesis of hydroxamate resin was accomplished by activating the carboxylate groups on a carboxymethyl cation exchange resin using methyl chloroformate followed by reaction with hydroxylamine hydrochloride. After trapping of (89)Zr on hydroxamate resin and rinsing the resin with HCl and water to release Y, (89)Zr was eluted with 1.2 M K2HPO4/KH2PO4 buffer (pH3.5). ICP-MS was used to measure metal contaminants in the final (89)Zr solution. The BMLT-2 target produced 349±49 MBq (9.4±1.2 mCi) of (89)Zr at the end of irradiation with a specific activity of 1.18±0.79 GBq/μg. The hydroxamate resin prepared using the new synthesis method showed a trapping efficiency of 93% with a 75 mg resin bed and 96-97% with a 100-120 mg resin bed. The elution efficiency of (89)Zr with 1.2M K2HPO4/KH2PO4 solution was found to be 91.7±3.7%, compared to >95% for 1 M oxalic acid. Elution with phosphate buffer gave very small levels of metal contaminants: Al=0.40-0.86 μg (n=2), Fe=1.22±0.71 μg (n=3), Y=0.29 μg (n=1). The BMLT-2 target allowed doubling of the beam current for production of (89)Zr, resulting in a greater than 2-fold increase in production yield in comparison with a conventional liquid target. The new one-pot synthesis of hydroxamate resin provides a simpler synthesis method for the (89)Zr trapping resin. Finally, phosphate buffer elutes the (89)Zrfrom the hydroxamate resin in high efficiency while at the same time providing a more biocompatible medium for subsequent use of (89)Zr. Copyright © 2015 Elsevier Inc. All rights reserved.

Exploration and Pharmacokinetic Profiling of Phenylalanine Based Carbamates as Novel Substance P 1–7 Analogues

PubMed Central

2014-01-01

The bioactive metabolite of Substance P, the heptapeptide SP1–7 (H-Arg-Pro-Lys-Pro-Gln-Gln-Phe-OH), has been shown to attenuate signs of hyperalgesia in diabetic mice, which indicate a possible use of compounds targeting the SP1–7 binding site as analgesics for neuropathic pain. Aiming at the development of drug-like SP1–7 peptidomimetics we have previously reported on the discovery of H-Phe-Phe-NH2 as a high affinity lead compound. Unfortunately, the pharmacophore of this compound was accompanied by a poor pharmacokinetic (PK) profile. Herein, further lead optimization of H-Phe-Phe-NH2 by substituting the N-terminal phenylalanine for a benzylcarbamate group giving a new type of SP1–7 analogues with good binding affinities is reported. Extensive in vitro as well as in vivo PK characterization is presented for this compound. Evaluation of different C-terminal functional groups, i.e., hydroxamic acid, acyl sulfonamide, acyl cyanamide, acyl hydrazine, and oxadiazole, suggested hydroxamic acid as a bioisosteric replacement for the original primary amide. PMID:25516784

Exploration and pharmacokinetic profiling of phenylalanine based carbamates as novel substance p 1-7 analogues.

PubMed

Fransson, Rebecca; Nordvall, Gunnar; Bylund, Johan; Carlsson-Jonsson, Anna; Kratz, Jadel M; Svensson, Richard; Artursson, Per; Hallberg, Mathias; Sandström, Anja

2014-12-11

The bioactive metabolite of Substance P, the heptapeptide SP1-7 (H-Arg-Pro-Lys-Pro-Gln-Gln-Phe-OH), has been shown to attenuate signs of hyperalgesia in diabetic mice, which indicate a possible use of compounds targeting the SP1-7 binding site as analgesics for neuropathic pain. Aiming at the development of drug-like SP1-7 peptidomimetics we have previously reported on the discovery of H-Phe-Phe-NH2 as a high affinity lead compound. Unfortunately, the pharmacophore of this compound was accompanied by a poor pharmacokinetic (PK) profile. Herein, further lead optimization of H-Phe-Phe-NH2 by substituting the N-terminal phenylalanine for a benzylcarbamate group giving a new type of SP1-7 analogues with good binding affinities is reported. Extensive in vitro as well as in vivo PK characterization is presented for this compound. Evaluation of different C-terminal functional groups, i.e., hydroxamic acid, acyl sulfonamide, acyl cyanamide, acyl hydrazine, and oxadiazole, suggested hydroxamic acid as a bioisosteric replacement for the original primary amide.

In silico modification of Zn2+ binding group of suberoylanilide hydroxamic acid (SAHA) by organoselenium compounds as Homo sapiens class II HDAC inhibitor of cervical cancer

NASA Astrophysics Data System (ADS)

Sumo Friend Tambunan, Usman; Bakri, Ridla; Aditya Parikesit, Arli; Ariyani, Titin; Dyah Puspitasari, Ratih; Kerami, Djati

2016-02-01

Cervical cancer is the most common cancer in women, and ranks seventh of all cancers worldwide, with 529000 cases in 2008 and more than 85% cases occur in developing countries. One way to treat this cancer is through the inhibition of HDAC enzymes which play a strategic role in the regulation of gene expression. Suberoyl Anilide Hydroxamic Acid (SAHA) or Vorinostat is a drug which commercially available to treat the cancer, but still has some side effects. This research present in silico SAHA modification in Zinc Binding Group (ZBG) by organoselenium compound to get ligands which less side effect. From molecular docking simulation, and interaction analysis, there are five best ligands, namely CC27, HA27, HB28, IB25, and KA7. These five ligands have better binding affinity than the standards, and also have interaction with Zn2+ cofactor of inhibited HDAC enzymes. This research is expected to produce more potent HDAC inhibitor as novel drug for cervical cancer treatment.

Hydroxamate anchors for improved photoconversion in dye-sensitized solar cells.

PubMed

Brewster, Timothy P; Konezny, Steven J; Sheehan, Stafford W; Martini, Lauren A; Schmuttenmaer, Charles A; Batista, Victor S; Crabtree, Robert H

2013-06-03

We present the first analysis of performance of hydroxamate linkers as compared to carboxylate and phosphonate groups when anchoring ruthenium-polypyridyl dyes to TiO2 surfaces in dye-sensitized solar cells (DSSCs). The study provides fundamental insight into structure/function relationships that are critical for cell performance. Our DSSCs have been produced by using newly synthesized dye molecules and characterized by combining measurements and simulations of experimental current density-voltage (J-V) characteristic curves. We show that the choice of anchoring group has a direct effect on the overall sunlight-to-electricity conversion efficiency (η), with hydroxamate anchors showing the best performance. Solar cells based on the pyridyl-hydroxamate complex exhibit higher efficiency since they suppress electron transfer from the photoanode to the electrolyte and have superior photoinjection characteristics. These findings suggest that hydroxamate anchoring groups should be particularly valuable in DSSCs and photocatalytic applications based on molecular adsorbates covalently bound to semiconductor surfaces. In contrast, analogous acetylacetonate anchors might undergo decomposition under similar conditions suggesting limited potential in future applications.

Dual function catalysts. Dehydrogenation and asymmetric intramolecular Diels-Alder cycloaddition of N-hydroxy formate esters and hydroxamic acids: evidence for a ruthenium-acylnitroso intermediate.

PubMed

Chow, Chun P; Shea, Kenneth J

2005-03-23

The chiral ruthenium salen complex, 13b, functions as an efficient catalyst for the sequential oxidation and asymmetric Diels-Alder cycloaddition of hydroxamic acids and N-hydroxy formate esters. This result provides evidence for the formation of a ruthenium-nitroso formate (acyl nitroso) intermediate. The Diels-Alder precursors are prepared from simple building blocks, and the cycloadducts, bridged oxazinolactams, can serve as useful intermediates in organic synthesis.

Utilization of Boron Compounds for the Modification of Suberoyl Anilide Hydroxamic Acid as Inhibitor of Histone Deacetylase Class II Homo sapiens

PubMed Central

Bakri, Ridla; Parikesit, Arli Aditya; Satriyanto, Cipta Prio; Kerami, Djati; Tambunan, Usman Sumo Friend

2014-01-01

Histone deacetylase (HDAC) has a critical function in regulating gene expression. The inhibition of HDAC has developed as an interesting anticancer research area that targets biological processes such as cell cycle, apoptosis, and cell differentiation. In this study, an HDAC inhibitor that is available commercially, suberoyl anilide hydroxamic acid (SAHA), has been modified to improve its efficacy and reduce the side effects of the compound. Hydrophobic cap and zinc-binding group of these compounds were substituted with boron-based compounds, whereas the linker region was substituted with p-aminobenzoic acid. The molecular docking analysis resulted in 8 ligands with ΔG binding value more negative than the standards, SAHA and trichostatin A (TSA). That ligands were analyzed based on the nature of QSAR, pharmacological properties, and ADME-Tox. It is conducted to obtain a potent inhibitor of HDAC class II Homo sapiens. The screening process result gave one best ligand, Nova2 (513246-99-6), which was then further studied by molecular dynamics simulations. PMID:25214833

Exploring bis-(indolyl)methane moiety as an alternative and innovative CAP group in the design of histone deacetylase (HDAC) inhibitors.

PubMed

Giannini, Giuseppe; Marzi, Mauro; Marzo, Maria Di; Battistuzzi, Gianfranco; Pezzi, Riccardo; Brunetti, Tiziana; Cabri, Walter; Vesci, Loredana; Pisano, Claudio

2009-05-15

In order to gather further knowledge about the structural requirements on histone deacetylase inhibitors (HDACi), starting from the schematic model of the common pharmacophore that characterizes this class of molecules (surface recognition CAP group-connection unit-linker region-Zinc Binding Group), we designed and synthesized a series of hydroxamic acids containing a bis-(indolyl)methane moiety. HDAC inhibition profile and antiproliferative activity were evaluated.

Synthesis of Pyrrolo[1,2-a]pyrimidine Enantiomers via Domino Ring-Closure followed by Retro Diels-Alder Protocol.

PubMed

Fekete, Beáta; Palkó, Márta; Haukka, Matti; Fülöp, Ferenc

2017-04-13

From 2-aminonorbornene hydroxamic acids, a simple and efficient method for the preparation of pyrrolo[1,2- a ]pyrimidine enantiomers is reported. The synthesis is based on domino ring-closure followed by microwave-induced retro Diels-Alder (RDA) protocols, where the chirality of the desired products is transferred from norbornene derivatives. The stereochemistry of the synthesized compounds was proven by X-ray crystallography. The absolute configuration of the product is determined by the configuration of the starting amino hydroxamic acid.

Discovery of a new class of histone deacetylase inhibitors with a novel zinc binding group.

PubMed

Li, Youxuan; Woster, Patrick M

2015-04-01

Small molecules featuring a hydroxamic acid or a benzamide zinc binding group (ZBG) are the most thoroughly studied histone deacetylase (HDAC) inhibitors. However, concerns about the pharmacokinetic liabilities of the hydroxamic acid moiety and potential metabolic toxicity of the aniline portion of benzamide HDAC inhibitors have stimulated research efforts aimed at discovering alternative ZBGs. Here we report the 2-(oxazol-2-yl)phenol moiety as a novel ZBG that can be used to produce compounds that are potent HDAC inhibitors. A series of analogues with this novel ZBG have been synthesized, and these analogues exhibit selective inhibition against HDAC1 as well as the class IIb HDACs (HDAC6 and HDAC10). Compound 10 possesses an IC 50 value of 7.5 μM in the MV-4-11 leukemia cell line, and induces a comparable amount of acetylated histone 3 lysine 9 (H3K9) and p21Waf1/CIP1 as 0.5 μM of SAHA. Modeling of compound 10 in the active site of HDAC2 demonstrates that the 2-(oxazol-2-yl)phenol moiety has a zinc-binding pattern similar to benzamide HDAC inhibitors.

Design, synthesis, molecular docking, anti-Proteus mirabilis and urease inhibition of new fluoroquinolone carboxylic acid derivatives.

PubMed

Abdullah, Mohammed A A; Abuo-Rahma, Gamal El-Din A A; Abdelhafez, El-Shimaa M N; Hassan, Heba A; Abd El-Baky, Rehab M

2017-02-01

New hydroxamic acid, hydrazide and amide derivatives of ciprofloxacin in addition to their analogues of levofloxacin were prepared and identified by different spectroscopic techniques. Some of the prepared compounds revealed good activity against the urease splitting bacteria, Proteus mirabilis. The urease inhibitory activity was investigated using indophenol method. Most of the tested compounds showed better activity than the reference acetohydroxamic acid (AHA). The ciprofloxacin hydrazide derivative 3a and levofloxacin hydroxamic acid 7 experienced the highest activity (IC 50 =1.22μM and 2.20μM, respectively). Molecular docking study revealed high spontaneous binding ability of the tested compounds to the active site of urease. Copyright © 2016 Elsevier Inc. All rights reserved.

Design and synthesis of novel and highly-active pan-histone deacetylase (pan-HDAC) inhibitors.

PubMed

Tashima, Toshihiko; Murata, Hiroaki; Kodama, Hidehiko

2014-07-15

Histone deacetylase (HDAC) inhibitions are known to elicit anticancer effects. We designed and synthesized several HDAC inhibitors. Among these compounds, compound 40 exhibited a more than 10-fold stronger inhibitory activity compared with that of suberoylanilide hydroxamic acid (SAHA) against each human HDAC isozyme in vitro (IC50 values of 40: HDAC1, 0.0038μM; HDAC2, 0.0082μM; HDAC3, 0.015μM; HDAC8, 0.0060μM; HDAC4, 0.058μM; HDAC9, 0.0052μM; HDAC6, 0.058μM). The dose of the administered HDAC inhibitors that contain hydroxamic acid as the zinc-binding group may be reduced by 40. Because the carbostyril subunit is a time-tested structural component of drugs and biologically active compounds, 40 most likely exhibits good absorption, distribution, metabolism, excretion, and toxicity (ADMET). Thus, compound 40 is expected to be a promising therapeutic agent or chemical tool for the investigation of life process. Copyright © 2014 Elsevier Ltd. All rights reserved.

Studies at the Ionizable Position of Cephalosporins and Penicillins: Hydroxamates as Substitutes for the Traditional Carboxylate Group

PubMed Central

Majewski, Mark W.; Miller, Patricia A.; Miller, Marvin J.

2016-01-01

Classically, β-lactams need an ionizable group to potentiate antibacterial activity. Sets of cephalosporins and penicillins featuring different substituted hydroxamates in place of the traditional carboxylate group have been synthesized and tested for antibiotic activity. Many of the compounds exhibited anti-bacterial activities with notable MIC values in the range of 6-0.2 μM. PMID:27999444

45Ti extraction using hydroxamate resin

NASA Astrophysics Data System (ADS)

Gagnon, K.; Severin, G. W.; Barnhart, T. E.; Engle, J. W.; Valdovinos, H. F.; Nickles, R. J.

2012-12-01

As an attractive radionuclide for positron emission tomography, this study explores the extraction and reactivity of 45Ti produced via the 45Sc(p,n)45Ti reaction on a GE PETtrace. Using a small hydroxamate column, we have demonstrated an overall recovery of >50% of 45Ti in ˜1 mL of 1M oxalic acid. Conditions for reacting with desferal were also explored, with effective specific activities up to 38 GBq/μmol obtained.

Speciation of plutonium and other metals under UREX process conditIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paulenova, Alena; Tkac, Peter; Matteson, Brent S.

2007-07-01

The extractability of various Pu and Np species into tri-n-butyl phosphate (TBP) was investigated. The concentration effects of aceto-hydroxamic acid, nitric acid and nitrate on the distribution ratio of U, Pu and Np were investigated. The considerable ability of AHA to form complexes with the studied elements even under strong acidic conditions was found. While the difference in the extraction of uranyl in the presence and absence of AHA is minimal, extraction yields of Pu and Np decrease significantly. The UV-Vis-NIR and FT-IR spectroscopic investigations of uranium, plutonium, and neptunium species in the presence and absence of AHA in bothmore » aqueous and organic extraction phase were also performed. Spectroscopic analysis showed that the organic phase can contain a substantial amount of metal-hydroxamate species. A solvated ternary complex of uranium UO{sub 2}.AHA.NO{sub 3}.2TBP was observed only after prolonged contact between the aqueous and organic phases, whereas the plutonium hydroxamate species, presumably Pu(AHA){sub x}(NO{sub 3}){sub 4-x}.2TBP, appeared in the organic phase after a four minute extraction. (authors)« less

Exploiting the biosynthetic machinery of Streptomyces pilosus to engineer a water-soluble zirconium(iv) chelator.

PubMed

Richardson-Sanchez, Tomas; Tieu, William; Gotsbacher, Michael P; Telfer, Thomas J; Codd, Rachel

2017-07-21

The water solubility of a natural product-inspired octadentate hydroxamic acid chelator designed to coordinate Zr(iv)-89 has been improved by using a combined microbiological-chemical approach to engineer four ether oxygen atoms into the main-chain region of a methylene-containing analogue. First, an analogue of the trimeric hydroxamic acid desferrioxamine B (DFOB) that contained three main-chain ether oxygen atoms (DFOB-O 3 ) was generated from cultures of the native DFOB-producer Streptomyces pilosus supplemented with oxybis(ethanamine) (OBEA), which competed against the native 1,5-diaminopentane (DP) substrate during DFOB assembly. This precursor-directed biosynthesis (PDB) approach generated a suite of DFOB analogues containing one (DFOB-O 1 ), two (DFOB-O 2 ) or three (DFOB-O 3 ) ether oxygen atoms, with the latter produced as the major species. Log P measurements showed DFOB-O 3 was about 45 times more water soluble than DFOB. Second, a peptide coupling chain-extension reaction between DFOB-O 3 and the synthetic ether-containing endo-hydroxamic acid monomer 4-((2-(2-aminoethoxy)ethyl)(hydroxy)amino)-4-oxobutanoic acid (PBH-O 1 ) gave the water soluble tetrameric hydroxamic acid DFOB-O 3 -PBH-O 1 as an isostere of sparingly water soluble DFOB-PBH. The complex between DFOB-O 3 -PBH-O 1 and nat Zr(iv), examined as a surrogate measure of the radiolabelling procedure, analysed by LC-MS as the protonated adduct ([M + H] + , m/z obs = 855.2; m/z calc = 855.3), with supporting HRMS data. The use of a microbiological system to generate a water-soluble analogue of a natural product for downstream semi-synthetic chemistry is an attractive pathway for developing new drugs and imaging agents. The improved water solubility of DFOB-O 3 -PBH-O 1 could facilitate the synthesis and purification of downstream products, as part of the ongoing development of ligands optimised for Zr(iv)-89 immunological PET imaging.

Glutamic acid is an active site residue of angiotensin I-converting enzyme. Use of the Lossen rearrangement for identification of dicarboxylic acid residues.

PubMed

Harris, R B; Wilson, I B

1983-01-25

A set of chemical reactions was used to show that one glutamic acid residue at the active site of bovine lung angiotensin I-converting enzyme is esterified with the alkylating agent p-[N,N-bis(chloroethyl)amino] phenylbutyryl-L-Pro (chlorambucyl-L-Pro), an affinity label for this enzyme (Harris, R. B., and Wilson, I. B. (1982) J. Biol. Chem. 257, 811-815). The same procedure was used to confirm that a glutamic acid residue of carboxypeptidase A alpha is esterified by reaction with bromoacetyl-N-methyl-L-phenylalanine (Haas, G. M., and Neurath, H. (1971) Biochemistry 10, 3535-3546). In the procedure described in this paper, the esterified residue at the active site is converted to the hydroxamic acid by reaction with hydroxylamine and the hydroxamic acid is subject to the Lossen rearrangement. If a glutamic acid residue was esterified, 1 eq of 2,4-diaminobutyric acid will be formed. Aspartyl esters will give 2,3-diaminopropionic acid. The diamino acids can be quantitatively measured using the short column of an amino acid analyzer if the amount of lysine and histidine is largely decreased by modification with suitable side chain protecting groups. With carboxypeptidase A, the reactions were done on the whole undigested enzyme. With the converting enzyme, we first cleaved the esterified enzyme with cyanogen bromide. Twenty-nine cleavage peptides were separated on high performance liquid chromatography and one of these contained all of the bound radioactive inhibitor. This active site peptide was then subjected to the derivatization and Lossen procedures, and 1 eq of 2,4-diaminobutyric acid was obtained.

Discovery of novel hydroxamates as highly potent tumor necrosis factor-[alpha] converting enzyme inhibitors. Part II: Optimization of the S3′ pocket

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mazzola Jr., Robert D.; Zhu, Zhaoning; Sinning, Lisa

2010-10-01

A series of cyclopropyl hydroxamic acids were prepared. Many of the compounds displayed picomolar affinity for the TACE enzyme while maintaining good to excellent selectivity profiles versus MMP-1, -2, -3, -7, -14, and ADAM-10. X-ray analysis of an inhibitor in the TACE active site indicated that the molecules bound to the enzyme in the S1{prime}-S3{prime} pocket.

Hydroxamic acids as weak base indicators: protonation in strong acid media.

PubMed

García, B; Ibeas, S; Hoyuelos, F J; Leal, J M; Secco, F; Venturini, M

2001-11-30

The protonation equilibria of N-phenylbenzohydroxamic, benzohydroxamic, salicylhydroxamic, and N-p-tolylcinnamohydroxamic acids have been studied at 25 degrees C in concentrated sulfuric, hydrochloric, and perchloric acid media; the UV-vis spectral measurements were analyzed using the Hammett equation and the Bunnett-Olsen and excess acidity methods. The medium effects observed in the UV spectral curves were corrected with the Cox-Yates and vector analysis methods. The H(A) acidity function based on benzamides provided the best results. The range of variation of the solvation coefficient m is similar to that of amides, this indicating similar solvation requirements for amides and hydroxamic acids. For the same substrate, the observed variations of pK(BH)(+) with the mineral acid used was justified by formation of solvent-separated ion pairs; for the same mineral acid, the observed changes in pK(BH)(+) can be explained by the solvation of BH(+). The change of the pK(BH)(+) values was in reasonably good agreement with the sequence of the catalytic efficiency of the mineral acids used, HCl > H(2)SO(4) > HClO(4).

Trithiocarbonates: exploration of a new head group for HDAC inhibitors.

PubMed

Dehmel, Florian; Ciossek, Thomas; Maier, Thomas; Weinbrenner, Steffen; Schmidt, Beate; Zoche, Martin; Beckers, Thomas

2007-09-01

Inhibition of histone deacetylases class I/II enzymes is a new, promising approach for cancer therapy. In the present study, we disclose a new structural class of HDAC inhibitors with the trithiocarbonate motif. A clear structure-activity-relationship was obtained for the cap-linker motif and the putative Zn(2+) complexing head group. Selected analogs display potent inhibition of HDAC enzymatic activity and a cellular potency comparable to that of suberoylanilide hydroxamic acid (SAHA), recently approved for treatment of patients with advanced cutaneous T-cell lymphoma.

Computational exploration of zinc binding groups for HDAC inhibition.

PubMed

Chen, Kai; Xu, Liping; Wiest, Olaf

2013-05-17

Histone deacetylases (HDACs) have emerged as important drug targets in epigenetics. The most common HDAC inhibitors use hydroxamic acids as zinc binding groups despite unfavorable pharmacokinetic properties. A two-stage protocol of M05-2X calculations of a library of 48 fragments in a small model active site, followed by QM/MM hybrid calculations of the full enzyme with selected binders, is used to prospectively select potential bidentate zinc binders. The energetics and interaction patterns of several zinc binders not previously used for the inhibition of HDACs are discussed.

Design, synthesis and biological evaluation of di-substituted cinnamic hydroxamic acids bearing urea/thiourea unit as potent histone deacetylase inhibitors.

PubMed

Ning, Chengqing; Bi, Yanjing; He, Yujun; Huang, WenYuan; Liu, Lifei; Li, Yi; Zhang, Sihan; Liu, Xiaoyu; Yu, Niefang

2013-12-01

A novel class of di-substituted cinnamic hydroxamic acid derivatives containing urea or thiourea unit was designed, synthesized and evaluated as HDAC inhibitors. All tested compounds demonstrated significant HDAC inhibitory activities and anti-proliferative effects against diverse human tumor cell lines. Among them, 7l exhibited most potent pan-HDAC inhibitory activity, with an IC50 value of 130 nM. It also showed strong cellular inhibition against diverse cell lines including HCT-116, MCF-7, MDB-MB-435 and NCI-460, with GI50 values of 0.35, 0.22, 0.51 and 0.48 μM, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

Carbamates as Potential Prodrugs and a New Warhead for HDAC Inhibition.

PubMed

King, Kristina; Hauser, Alexander-Thomas; Melesina, Jelena; Sippl, Wolfgang; Jung, Manfred

2018-02-02

We designed and synthesized carbamates of the clinically-approved HDAC (histone deacetylase) inhibitor vorinostat (suberoylanilide hydroxamic acid, SAHA) in order to validate our previously-proposed hypothesis that these carbamates might serve as prodrugs for hydroxamic acid containing HDAC inhibitors. Biochemical assays proved our new compounds to be potent inhibitors of histone deacetylases in vitro, and they also showed antiproliferative effects in leukemic cells. These results, as well as stability analysis led to the suggestion that the intact carbamates are inhibitors of histone deacetylases themselves, representing a new zinc-binding warhead in HDAC inhibitor design. This suggestion was further supported by the synthesis and evaluation of a carbamate derivative of the HDAC6-selective inhibitor bufexamac.

Inhibition of class IIb histone deacetylase significantly improves cloning efficiency in mice.

PubMed

Ono, Tetsuo; Li, Chong; Mizutani, Eiji; Terashita, Yukari; Yamagata, Kazuo; Wakayama, Teruhiko

2010-12-01

Since the first mouse clone was produced by somatic cell nuclear transfer, the success rate of cloning in mice has been extremely low. Some histone deacetylase inhibitors, such as trichostatin A and scriptaid, have improved the full-term development of mouse clones significantly, but the mechanisms allowing for this are unclear. Here, we found that two other specific inhibitors, suberoylanilide hydroxamic acid and oxamflatin, could also reduce the rate of apoptosis in blastocysts, improve the full-term development of cloned mice, and increase establishment of nuclear transfer-generated embryonic stem cell lines significantly without leading to obvious abnormalities. However, another inhibitor, valproic acid, could not improve cloning efficiency. Suberoylanilide hydroxamic acid, oxamflatin, trichostatin A, and scriptaid are inhibitors for classes I and IIa/b histone deacetylase, whereas valproic acid is an inhibitor for classes I and IIa, suggesting that inhibiting class IIb histone deacetylase is an important step for reprogramming mouse cloning efficiency.

(7-Diethylaminocoumarin-4-yl)methyl ester of suberoylanilide hydroxamic acid as a caged inhibitor for photocontrol of histone deacetylase activity.

PubMed

Ieda, Naoya; Yamada, Sota; Kawaguchi, Mitsuyasu; Miyata, Naoki; Nakagawa, Hidehiko

2016-06-15

Histone deacetylases (HDACs) are involved in epigenetic control of the expression of various genes by catalyzing deacetylation of ε-acetylated lysine residues. Here, we report the design, synthesis and evaluation of the (7-diethylaminocoumarin-4-yl)methyl ester of suberoylanilide hydroxamic acid (AC-SAHA) as a caged HDAC inhibitor, which releases the known pan-HDAC inhibitor SAHA upon cleavage of the photolabile (7-diethylaminocoumarin-4-yl)methyl protecting group in response to photoirradiation. A key advantage of AC-SAHA is that the caged derivative itself shows essentially no HDAC-inhibitory activity. Upon photoirradiation, AC-SAHA decomposes to SAHA and a 7-diethylaminocoumarin derivative, together with some minor products. We confirmed that AC-SAHA inhibits HDAC in response to photoirradiation in vitro by means of chemiluminescence assay. AC-SAHA also showed photoinduced inhibition of proliferation of human colon cancer cell line HCT116, as determined by MTT assay. Thus, AC-SAHA should be a useful tool for spatiotemporally controlled inhibition of HDAC activity, as well as a candidate chemotherapeutic reagent for human colon cancer. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Iron chelating active packaging: Influence of competing ions and pH value on effectiveness of soluble and immobilized hydroxamate chelators.

PubMed

Ogiwara, Yoshiko; Roman, Maxine J; Decker, Eric A; Goddard, Julie M

2016-04-01

Many packaged foods utilize synthetic chelators (e.g. ethylenediaminetetraacetic acid, EDTA) to inhibit iron-promoted oxidation or microbial growth which would result in quality loss. To address consumer demands for all natural products, we have previously developed a non-migratory iron chelating active packaging material by covalent immobilization of polyhydroxamate and demonstrated its efficacy in delaying lipid oxidation. Herein, we demonstrate the ability of this hydroxamate-functionalized iron chelating active packaging to retain iron chelating capacity; even in the presence of competing ions common in food. Both immobilized and soluble hydroxamate chelators retained iron chelating capacity in the presence of calcium, magnesium, and sodium competing ions, although at pH 5.0 the presence of calcium reduced immobilized hydroxamate iron chelation. A strong correlation was found between colorimetric and mass spectral analysis of iron chelation by the chelating packaging material. Such chelating active packaging may support reducing additive use in product formulations, while retaining quality and shelf life. Copyright © 2015 Elsevier Ltd. All rights reserved.

Suberoylanilide hydroxamic acid (vorinostat): its role on equine corneal fibrosis and matrix metalloproteinase activity.

PubMed

Donnelly, Kevin S; Giuliano, Elizabeth A; Sharm, Ajay; Mohan, Rajiv R

2014-07-01

To explore the effect of suberoylanilide hydroxamic acid (SAHA) (i) on corneal fibroblast differentiation, morphology, and viability; and (ii) on the expression levels of matrix metalloproteinases (MMPs) 2 and 9 using an in vitro model of equine corneal fibrosis. Healthy donor corneas were used to generate primary cultures of equine corneal fibroblasts. The fibroblasts were exposed to 5 ng/mL TGFβ1 to induce myofibroblast formation. The cultures were treated with either 5 μm or 10 μm SAHA for 72 h in the presence of TGFβ1. Real-time PCR and immunocytochemistry were used to determine the antifibrotic efficacy of SAHA by quantifying α-smooth muscle actin (αSMA), a marker of myofibroblast formation and fibrosis. Real-time PCR was used to determine the effects of SAHA on MMP2 and MMP9 expression. Cytotoxicity of SAHA was evaluated with phase contrast microscopy and trypan blue exclusion assays. Suberoylanilide hydroxamic acid (SAHA) significantly attenuated TGFβ1-induced differentiation of equine fibroblasts to myofibroblasts as indicated by 3- to 3.5-fold (P < 0.001) decrease in αSMA mRNA and 86-88% (P < 0.001) decrease in αSMA+ immunocytochemical staining. SAHA treatment also resulted in 4.5- to 5.5-fold (P < 0.01) decrease in MMP9 expression. A dose-dependent bimodal effect of SAHA on MMP2 expression was noted (3.5-fold increase with 5 μm dose; 0.5-fold decrease with 10 μm dose). No change in fibroblast viability was observed with a 5 μm SAHA dose, whereas a 10 μm dose resulted in a moderate 17% decrease in cell viability. Suberoylanilide hydroxamic acid (SAHA) can effectively inhibit TGFβ-induced differentiation of equine corneal fibroblasts to myofibroblasts and modulates MMP production in vitro. © 2013 American College of Veterinary Ophthalmologists.

Facile solid-phase synthesis of C-terminal peptide aldehydes and hydroxamates from a common Backbone Amide-Linked (BAL) intermediate.

PubMed

Gazal, S; Masterson, L R; Barany, G

2005-12-01

C-Terminal peptide aldehydes and hydroxamates comprise two separate classes of effective inhibitors of a number of serine, aspartate, cysteine, and metalloproteases. Presented here is a method for preparation of both classes of peptide derivatives from the same resin-bound Weinreb amide precursor. Thus, 5-[(2 or 4)-formyl-3,5-dimethoxyphenoxy]butyramido-polyethylene glycol-polystyrene (BAL-PEG-PS) was treated with methoxylamine hydrochloride in the presence of sodium cyanoborohydride to provide a resin-bound methoxylamine, which was efficiently acylated by different Fmoc-amino acids upon bromo-tris-pyrrolidone-phosphonium hexafluorophosphate (PyBrOP) activation. Solid-phase chain elongation gave backbone amide-linked (BAL) peptide Weinreb amides, which were cleaved either by trifluoroacetic acid (TFA) in the presence of scavengers to provide the corresponding peptide hydroxamates, or by lithium aluminum hydride in tetrahydrofuran (THF) to provide the corresponding C-terminal peptide aldehydes. With several model sequences, peptide hydroxamates were obtained in crude yields of 68-83% and initial purities of at least 85%, whereas peptide aldehydes were obtained in crude yields of 16-53% and initial purities in the range of 30-40%. Under the LiAlH4 cleavage conditions used, those model peptides containing t-Bu-protected aspartate residues underwent partial side chain reduction to the corresponding homoserine-containing peptides. Similar results were obtained when working with high-load aminomethyl-polystyrene, suggesting that this chemistry will be generally applicable to a range of supporting materials.

Contaminant Organic Complexes: Their Structure and Energetics in Surface Decontamination Processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Satish C. B. Myneni

2005-12-13

Siderophores are biological macromolecules (400-2000 Da) released by bacteria in iron limiting situations to sequester Fe from iron oxyhydroxides and silicates in the natural environment. These molecules contain hydroxamate and phenolate functional groups, and exhibit very high affinity for Fe{sup 3+}. While several studies were conducted to understand the behavior of siderophores and their application to the metal sequestration and mineral dissolution, only a few of them have examined the molecular structure of siderophores and their interactions with metals and mineral surfaces in aqueous solutions. Improved understanding of the chemical state of different functional moieties in siderophores can assist inmore » the application of these biological molecules in actinide separation, sequestration and decontamination processes. The focus of our research group is to evaluate the (a) functional group chemistry of selected siderophores and their metal complexes in aqueous solutions, and (b) the nature of siderophore interactions at the mineral-water interfaces. We selected desferrioxamine B (desB), a hydroxamate siderophore, and its small structural analogue, acetohydroxamic acid (aHa), for this investigation. We examined the functional group chemistry of these molecules as a function of pH, and their complexation with aqueous and solid phase Fe(III). For solid phase Fe, we synthesized all naturally occurring Fe(III)-oxyhydroxides (goethite, lepidocrocite, akaganeite, feroxyhite) and hematite. We also synthesized Fe-oxides (goethite and hematite) of different sizes to evaluate the influence of particle size on mineral dissolution kinetics. We used a series of molecular techniques to explore the functional group chemistry of these molecules and their complexes. Infrared spectroscopy is used to specifically identify the variations in oxime group as a function of pH and Fe(III) complexation. Resonance Raman spectroscopy was used to evaluate the nature of hydroxamate binding in the case of Fe(III)-siderophore complexes and model ligands. Soft and hard X-ray spectroscopy techniques were used to examine the electronic structure of binding groups, and their local structural environment. The synchrotron X-ray studies were conducted at the Stanford Synchrotron Radiation Laboratory and at the Advanced Light Source (Lawrence Berkeley National Laboratory). These experimental vibrational and X-ray spectroscopy studies were complemented with density functional theory calculations. The highlight of this study is the evaluation of the fundamental electronic state information of the hydroxamate moiety in siderophores during deprotonation and Fe(III) complexation. The applications of soft X-ray studies are also new, and were applied, for the first time, to examine the chemistry of organic macromolecules in aqueous solutions.« less

Experimental and theoretical vibrational spectroscopy studies of acetohydroxamic acid and desferrioxamine B in aqueous solution: Effects of pH and iron complexation

NASA Astrophysics Data System (ADS)

Edwards, David C.; Nielsen, Steen B.; Jarzęcki, Andrzej A.; Spiro, Thomas G.; Myneni, Satish C. B.

2005-07-01

The deprotonation and iron complexation of the hydroxamate siderophore, desferrioxamine B (desB), and a model hydroxamate ligand, acetohydroxamic acid (aHa), were studied using infrared, resonance Raman and UV-vis spectroscopy. The experimental spectra were interpreted by a comparison with DFT calculated spectra of aHa (partly hydrated) and desB (reactive groups of unhydrated molecule) at the B3LYP/6-31G* level of theory. The ab initio models include three water molecules surrounding the deprotonation site of aHa to account for partial hydration. Experiments and calculations were also conducted in D 2O to verify spectral assignments. These studies of aHa suggest that the cis-keto-aHa is the dominant form, and its deprotonation occurs at the oxime oxygen atom in aqueous solutions. The stable form of iron-complexed aHa is identified as Fe(aHa) 3 for a wide range of pH conditions. The spectral information of aHa and an ab initio model of desB were used to interpret the chemical state of different functional groups in desB. Vibrational spectra of desB indicate that the oxime and amide carbonyl groups can be identified unambiguously. Vibrational spectral analysis of the oxime carbonyl after deprotonation and iron complexation of desB indicates that the conformational changes between anion and the iron-complexed anion are small. Enhanced electron delocalization in the oxime group of Fe-desB when compared to that of Fe(aHa) 3 may be responsible for higher stability constant of the former.

Cu(I)/Cu(II) mixed-valence surface complexes of S-[(2-hydroxyamino)-2-oxoethyl]-N,N-dibutyldithiocarbamate: Hydrophobic mechanism to malachite flotation.

PubMed

Liu, Sheng; Zhong, Hong; Liu, Guangyi; Xu, Zhenghe

2018-02-15

Hydroxamate and sulfhydryl surfactants are effective collectors for flotation of copper minerals. The combination application of hydroxamate and sulfhydryl collectors has been proved to be an effective approach for improving the flotation recovery of non-sulfide copper minerals. A surfactant owing both hydroxamate and dithiocarbamate groups might exhibit strong affinity to non-sulfide copper minerals through double sites adsorption, rendering an enhanced hydrophobization to non-sulfide copper minerals flotation. The flotation performance of S-[(2-hydroxyamino)-2-oxoethyl]- N,N-dibutyldithiocarbamate (HABTC) to malachite, calcite and quartz were first evaluated through systematic micro-flotation experiments. HABTC's hydrophobic mechanism to malachite was further investigated and analyzed by zeta potential, Fourier transform infrared spectroscopy (FTIR), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS). The micro-flotation results demonstrated HABTC was an excellent collector for malachite flotation and exhibited favorable selectivity for flotation separation of malachite from quartz or calcite under pH 8.5-10.3. Zeta potential and FTIR implied that HABTC might bond with the surface copper atoms of malachite, with releasing the H + ions of its hydroxamate group into pulp. ToF-SIMS provided clear evidences that the Cu-hydroxamate and Cu-dithiocarbamate groups were formed on malachite surfaces after HABTC adsorption. XPS revealed that Cu(I)/Cu(II) mixed-valence surface complexes of HABTC anchored on malachite through formation of Cu(I)S and Cu(II)O bonds, accompanying with reduction of partial surface Cu(II) to Cu(I). The Cu(I)/Cu(II) mixed-valence double chelating character and "chair"-shape N,N-dibutyldithiocarbamate hydrophobic group, resulting in an enhanced affinity and hydrophobization of HABTC to malachite flotation. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluation of adamantane hydroxamates as botulinum neurotoxin inhibitors: synthesis, crystallography, modeling, kinetic and cellular based studies.

PubMed

Šilhár, Peter; Silvaggi, Nicholas R; Pellett, Sabine; Čapková, Kateřina; Johnson, Eric A; Allen, Karen N; Janda, Kim D

2013-03-01

Botulinum neurotoxins (BoNTs) are the most lethal biotoxins known to mankind and are responsible for the neuroparalytic disease botulism. Current treatments for botulinum poisoning are all protein based and thus have a limited window of treatment opportunity. Inhibition of the BoNT light chain protease (LC) has emerged as a therapeutic strategy for the treatment of botulism as it may provide an effective post exposure remedy. Using a combination of crystallographic and modeling studies a series of hydroxamates derived from 1-adamantylacetohydroxamic acid (3a) were prepared. From this group of compounds, an improved potency of about 17-fold was observed for two derivatives. Detailed mechanistic studies on these structures revealed a competitive inhibition model, with a K(i)=27 nM, which makes these compounds some of the most potent small molecule, non-peptidic BoNT/A LC inhibitors reported to date. Copyright © 2012 Elsevier Ltd. All rights reserved.

Complex structure of a bacterial class 2 histone deacetylase homologue with a trifluoromethylketone inhibitor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nielsen, Tine Kragh; Hildmann, Christian; Riester, Daniel

2007-04-01

The crystal structure of HDAH FB188 in complex with a trifluoromethylketone at 2.2 Å resolution is reported and compared to a previously determined inhibitor complex. Histone deacetylases (HDACs) have emerged as attractive targets in anticancer drug development. To date, a number of HDAC inhibitors have been developed and most of them are hydroxamic acid derivatives, typified by suberoylanilide hydroxamic acid (SAHA). Not surprisingly, structural information that can greatly enhance the design of novel HDAC inhibitors is so far only available for hydroxamic acids in complex with HDAC or HDAC-like enzymes. Here, the first structure of an enzyme complex with amore » nonhydroxamate HDAC inhibitor is presented. The structure of the trifluoromethyl ketone inhibitor 9,9,9-trifluoro-8-oxo-N-phenylnonanamide in complex with bacterial FB188 HDAH (histone deacetylase-like amidohydrolase from Bordetella/Alcaligenes strain FB188) has been determined. HDAH reveals high sequential and functional homology to human class 2 HDACs and a high structural homology to human class 1 HDACs. Comparison with the structure of HDAH in complex with SAHA reveals that the two inhibitors superimpose well. However, significant differences in binding to the active site of HDAH were observed. In the presented structure the O atom of the trifluoromethyl ketone moiety is within binding distance of the Zn atom of the enzyme and the F atoms participate in interactions with the enzyme, thereby involving more amino acids in enzyme–inhibitor binding.« less

Virtual medicinal chemistry: in silico pre-docking functional group transformation for discovery of novel inhibitors of botulinum toxin serotype A light chain.

PubMed

O'Malley, Sean; Sareth, Sina; Jiao, Guan-Sheng; Kim, Seongjin; Thai, April; Cregar-Hernandez, Lynne; McKasson, Linda; Margosiak, Stephen A; Johnson, Alan T

2013-05-01

A novel method for applying high-throughput docking to challenging metalloenzyme targets is described. The method utilizes information-based virtual transformation of library carboxylates to hydroxamic acids prior to docking, followed by compound acquisition, one-pot (two steps) chemical synthesis and in vitro screening. In two experiments targeting the botulinum neurotoxin serotype A metalloprotease light chain, hit rates of 32% and 18% were observed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Zinc binding groups for histone deacetylase inhibitors.

PubMed

Zhang, Lei; Zhang, Jian; Jiang, Qixiao; Zhang, Li; Song, Weiguo

2018-12-01

Zinc binding groups (ZBGs) play a crucial role in targeting histone deacetylase inhibitors (HDACIs) to the active site of histone deacetylases (HDACs), thus determining the potency of HDACIs. Due to the high affinity to the zinc ion, hydroxamic acid is the most commonly used ZBG in the structure of HDACs. An alternative ZBG is benzamide group, which features excellent inhibitory selectivity for class I HDACs. Various ZBGs have been designed and tested to improve the activity and selectivity of HDACIs, and to overcome the pharmacokinetic limitations of current HDACIs. Herein, different kinds of ZBGs are reviewed and their features have been discussed for further design of HDACIs.

Histone deacetylase inhibitors with a primary amide zinc binding group display antitumor activity in xenograft model.

PubMed

Attenni, Barbara; Ontoria, Jesus M; Cruz, Jonathan C; Rowley, Michael; Schultz-Fademrecht, Carsten; Steinkühler, Christian; Jones, Philip

2009-06-01

Histone deacetylase (HDAC) inhibition causes hyperacetylation of histones leading to differentiation, growth arrest and apoptosis of malignant cells, representing a new strategy in cancer therapy. Many of the known HDAC inhibitors (HDACi) that are in clinical trials possess a hydroxamic acid, that is a strong Zn(2+) binding group, thereby inhibiting some of the class I and class II isoforms. Herein we describe the identification of a selective class I HDAC inhibitor bearing a primary carboxamide moiety as zinc binding group. This HDACi displays good antiproliferative activity against multiple cancer cell lines, and demonstrates efficacy in a xenograft model comparable to vorinostat.

Synergistic Effect of the Combination of Novel Suberoylanilide Hydroxamic Acid Derivatives with Cisplatin on Anti-proliferation of Human Cancer Cells.

PubMed

Xie, Rui; Shi, Jinghua; Cheng, Chunhui; Yun, Fan; Liu, Xia; Tang, Pingwah; Wu, Xinying; Yang, Ming; Yuan, Qipeng

2016-01-01

A novel, green, and atom-economical boric acid catalyzed direct amidation without the use of any coupling agents for the preparation of suberoylanilide hydroxamic acid (SAHA) and SAHA-based inhibitors targeting anti-proliferation of cancer cells is provided. The new SAHA-based inhibitor B123, when used alone, exhibited higher anti-proliferative activities than SAHA or Cisplatin against a number of human cancer cells. We have examined the effect of combination of these SAHA-based inhibitors with Cisplatin. We found synergistic effects of the combination of SAHA-based inhibitors with Cisplatin over a wide range of concentrations against human liver cancer cells HepG2 and two human lung cancer cell lines H1299 and H460. This synergism leads up to 8-fold of dose reduction for Cisplatin in the combination with our synthesized inhibitor B123 against H1299.

Thiol Versus Hydroxamate as Zinc Binding Group In HDAC Inhibition: An Ab Initio QM/MM Molecular Dynamics Study

PubMed Central

Gong, Wenjing; Wu, Ruibo; Zhang, Yingkai

2015-01-01

Zinc-dependent histone deacetylases (HDACs) play a critical role in transcriptional repression and gene silencing, and are among the most attractive targets for the development of new therapeutics against cancer and various other diseases. Two HDAC inhibitors have been approved by FDA as anti-cancer drugs: one is SAHA whose hydroxamate is directly bound to zinc, the other is FK228 whose active form may use thiol as the zinc binding group. In spite of extensive studies, it remains to be ambiguous regarding how thiol and hydroxamate are bound to the zinc active site of HDACs. In this work, our computational approaches center on Born-Oppenheimer ab initio quantum mechanical/molecular mechanical (QM/MM) molecular dynamics with umbrella sampling, which allow for modeling of the zinc active site with reasonable accuracy while properly including dynamics and effects of protein environment. Meanwhile, an improved short-long effective function (SLEF2) to describe non-bonded interactions between zinc and other atoms has been employed in initial MM equilibrations. Our ab initio QM/MM MD simulations have confirmed that hydroxamate is neutral when it is bound to HDAC8, and found that thiol is deprotonated when directly bound to zinc in the HDAC active site. By comparing thiol and hydroxamate, our results elucidated the differences in their binding environment in the HDAC active sites, and emphasized the importance of the linker design to achieve more specific binding towards class IIa HDACs. PMID:26452222

Thiol versus hydroxamate as zinc binding group in HDAC inhibition: An ab initio QM/MM molecular dynamics study.

PubMed

Gong, Wenjing; Wu, Ruibo; Zhang, Yingkai

2015-11-15

Zinc-dependent histone deacetylases (HDACs) play a critical role in transcriptional repression and gene silencing, and are among the most attractive targets for the development of new therapeutics against cancer and various other diseases. Two HDAC inhibitors have been approved by FDA as anti-cancer drugs: one is SAHA whose hydroxamate is directly bound to zinc, the other is FK228 whose active form may use thiol as the zinc binding group. In spite of extensive studies, it remains to be ambiguous regarding how thiol and hydroxamate are bound to the zinc active site of HDACs. In this work, our computational approaches center on Born-Oppenheimer ab initio quantum mechanical/molecular mechanical (QM/MM) molecular dynamics with umbrella sampling, which allow for modeling of the zinc active site with reasonable accuracy while properly including dynamics and effects of protein environment. Meanwhile, an improved short-long effective function (SLEF2) to describe non-bonded interactions between zinc and other atoms has been employed in initial MM equilibrations. Our ab initio QM/MM MD simulations have confirmed that hydroxamate is neutral when it is bound to HDAC8, and found that thiol is deprotonated when directly bound to zinc in the HDAC active site. By comparing thiol and hydroxamate, our results elucidated the differences in their binding environment in the HDAC active sites, and emphasized the importance of the linker design to achieve more specific binding toward class IIa HDACs. © 2015 Wiley Periodicals, Inc.

Penicillins and other acylamino compounds synthesized by the cell-bound penicillin acylase of Escherichia coli

PubMed Central

Cole, M.

1969-01-01

1. The penicillin acylase of Eschericha coli N.C.I.B. 8743 is a reversible enzyme. Reaction rates for the two directions have been determined. 2. Measurements of the rates of enzymic synthesis of penicillins from 6-aminopenicillanic acid and various carboxylic acids revealed that p-hydroxyphenylacetic acid was the best substrate, followed by phenylacetic, 2-thienylacetic, substituted phenylacetic, 3-hexenoic and n-hexanoic acids. 3. The rate of synthesis of penicillin improved when amides or N-acylglycines were used; α-aminobenzylpenicillin and phenoxymethylpenicillin were only synthesized when using these more energy-rich compounds. 4. Phenyl-acetylglycine was the best substrate for the synthesis of benzylpenicillin compared with other derivatives of phenylacetic acid. 5. The enzyme was specific for acyl-l-amino acids, benzylpenicillin being synthesized from phenylacetyl-l-α-aminophenylacetic acid but not from phenylacetyl-d-α-aminophenylacetic acid. 6. α-Phenoxyethylpenicillin was synthesized from 6-aminopenicillanic acid and α-phenoxypropionylthioglycollic acid non-enzymically, but the rate was faster in the presence of the enzyme. 7. The E. coli acylase catalysed the acylation of hydroxylamine by acids or amides to give hydroxamic acids, the phenylacetyl group being the most suitable acyl group. The enzyme also catalysed other acyl-group transfers. PMID:4982418

Entropy as a Driver of Selectivity for Inhibitor Binding to Histone Deacetylase 6.

PubMed

Porter, Nicholas J; Wagner, Florence F; Christianson, David W

2018-05-18

Among the metal-dependent histone deacetylases, the class IIb isozyme HDAC6 is remarkable because of its role in the regulation of microtubule dynamics in the cytosol. Selective inhibition of HDAC6 results in microtubule hyperacetylation, leading to cell cycle arrest and apoptosis, which is a validated strategy for cancer chemotherapy and the treatment of other disorders. HDAC6 inhibitors generally consist of a Zn 2+ -binding group such as a hydroxamate, a linker, and a capping group; the capping group is a critical determinant of isozyme selectivity. Surprisingly, however, even "capless" inhibitors exhibit appreciable HDAC6 selectivity. To probe the chemical basis for this selectivity, we now report high-resolution crystal structures of HDAC6 complexed with capless cycloalkyl hydroxamate inhibitors 1-4. Each inhibitor hydroxamate group coordinates to the catalytic Zn 2+ ion with canonical bidentate geometry. Additionally, the olefin moieties of compounds 2 and 4 bind in an aromatic crevice between the side chains of F583 and F643. Reasoning that similar binding could be achieved in the representative class I isozyme HDAC8, we employed isothermal titration calorimetry to study the thermodynamics of inhibitor binding. These measurements indicate that the entropy of inhibitor binding is generally positive for binding to HDAC6 and negative for binding to HDAC8, resulting in ≤313-fold selectivity for binding to HDAC6 relative to HDAC8. Thus, favorable binding entropy contributes to HDAC6 selectivity. Notably, cyclohexenyl hydroxamate 2 represents a promising lead for derivatization with capping groups that may further enhance its impressive 313-fold thermodynamic selectivity for HDAC6 inhibition.

Inhibition of urease activity in the urinary tract pathogen Staphylococcus saprophyticus.

PubMed

Loes, A N; Ruyle, L; Arvizu, M; Gresko, K E; Wilson, A L; Deutch, C E

2014-01-01

Urease is a virulence factor for the Gram-positive urinary tract pathogen Staphylococcus saprophyticus. The susceptibility of this enzyme to chemical inhibition was determined using soluble extracts of Staph. saprophyticus strain ATCC 15305. Acetohydroxamic acid (Ki = 8.2 μg ml(-1) = 0.106 mmol l(-1) ) and DL-phenylalanine hydroxamic acid (Ki = 21 μg ml(-1) = 0.116 mmol l(-1) ) inhibited urease activity competitively. The phosphorodiamidate fluorofamide also caused competitive inhibition (Ki = 0.12 μg ml(-1) = 0.553 μmol l(-1) = 0.000553 mmol l(-1) ), but the imidazole omeprazole had no effect. Two flavonoids found in green tea extract [(+)-catechin hydrate (Ki = 357 μg ml(-1) = 1.23 mmol l(-1) ) and (-)-epigallocatechin gallate (Ki = 210 μg ml(-1) = 0.460 mmol l(-1) )] gave mixed inhibition. Acetohydroxamic acid, DL-phenylalanine hydroxamic acid, fluorofamide, (+)-catechin hydrate and (-)-epigallocatechin gallate also inhibited urease activity in whole cells of strains ATCC 15305, ATCC 35552 and ATCC 49907 grown in a rich medium or an artificial urine medium. Addition of acetohydroxamic acid or fluorofamide to cultures of Staph. saprophyticus in an artificial urine medium delayed the increase in pH that normally occurs during growth. These results suggest that urease inhibitors may be useful for treating urinary tract infections caused by Staph. saprophyticus. The enzyme urease is a virulence factor for the Gram-positive urinary tract pathogen Staphylococcus saprophyticus. We have shown that urease activity in cell-free extracts and whole bacterial cells is susceptible to inhibition by hydroxamates, phosphorodiamidates and flavonoids, but not by imidazoles. Acetohydroxamic acid and fluorofamide in particular can temporarily delay the increase in pH that occurs when Staph. saprophyticus is grown in an artificial urine medium. These results suggest that urease inhibitors may be useful as chemotherapeutic agents for the treatment of urinary tract infections caused by this micro-organism. © 2013 The Society for Applied Microbiology.

Bio-waste corn-cob cellulose supported poly(hydroxamic acid) copper complex for Huisgen reaction: Waste to wealth approach.

PubMed

Mandal, Bablu Hira; Rahman, Md Lutfor; Yusoff, Mashitah Mohd; Chong, Kwok Feng; Sarkar, Shaheen M

2017-01-20

Corn-cob cellulose supported poly(hydroxamic acid) Cu(II) complex was prepared by the surface modification of waste corn-cob cellulose through graft copolymerization and subsequent hydroximation. The complex was characterized by IR, UV, FESEM, TEM, XPS, EDX and ICP-AES analyses. The complex has been found to be an efficient catalyst for 1,3-dipolar Huisgen cycloaddition (CuAAC) of aryl/alkyl azides with a variety of alkynes as well as one-pot three-components reaction in the presence of sodium ascorbate to give the corresponding cycloaddition products in up to 96% yield and high turn over number (TON 18,600) and turn over frequency (TOF 930h -1 ) were achieved. The complex was easy to recover from the reaction mixture and reused six times without significant loss of its catalytic activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

4-N-Hydroxy-4-[1-(sulfonyl)piperidin-4-yl]-butyramides as HDAC inhibitors.

PubMed

Rossi, Cristina; Fincham, Christopher I; D'Andrea, Piero; Porcelloni, Marina; Ettorre, Alessandro; Mauro, Sandro; Bigioni, Mario; Binaschi, Monica; Maggi, Carlo A; Nardelli, Federica; Parlani, Massimo; Fattori, Daniela

2011-11-15

A series of N-substituted 4-alkylpiperidine hydroxamic acids, corresponding to the basic structure of histone deacetylase (HDAC) inhibitors (zinc binding moiety-linker-capping group) has been previously reported by our group. Linker length and aromatic capping group connection were systematically varied to find the optimal geometric parameters. A new series of submicromolar inhibitors was thus identified, which showed antiproliferative activity on HCT-116 colon carcinoma cells. We report here the second part of the strategy used in our research group to find a new class of HDAC inhibitors, namely the SAR study for the compounds bearing a sulfonyl group on the piperidine nitrogen. In the present work, we have considered both sulfonamides and sulfonyl ureas. Copyright © 2011 Elsevier Ltd. All rights reserved.

Synthesis and structural characterization of dioxomolybdenum and dioxotungsten hydroxamato complexes and their function in the protection of radiation induced DNA damage.

PubMed

Paul, Shiv Shankar; Selim, Md; Saha, Abhijit; Mukherjea, Kalyan K

2014-02-21

The synthesis and structural characterization of two novel dioxomolybdenum(VI) (1) and dioxotungsten(VI) (2) complexes with 2-phenylacetylhydroxamic acid (PAHH) [M(O)2(PAH)2] [M = Mo, W] have been accomplished. The dioxomolybdenum(VI) and dioxotungsten(VI) moiety is coordinated by the hydroxamate group (-CONHO(-)) of the 2-phenylacetylhydroxamate (PAH) ligand in a bi-dentate fashion. In both the complexes the PAHH ligand is coordinated through oxygen atoms forming a five membered chelate. The hydrogen atom of N-H of the hydroxamate group is engaged in intermolecular H-bonding with the carbonyl oxygen of another coordinated hydroxamate ligand, thereby forming an extended 1D chain. The ligand as well as both the complexes exhibit the ability to protect from radiation induced damage both in CTDNA as well as in pUC19 plasmid DNA. As the damage to DNA is caused by the radicals generated during radiolysis, its scavenging imparts protection from the damage to DNA. To understand the mechanism of protection, binding affinities of the ligand and the complex with DNA were determined using absorption and emission spectral studies and viscosity measurements, whereby the results indicate that both the complexes and the hydroxamate ligand interact with calf thymus DNA in the minor groove. The intrinsic binding constants, obtained from UV-vis studies, are 7.2 × 10(3) M(-1), 5.2 × 10(4) M(-1) and 1.2 × 10(4) M(-1) for the ligand and complexes 1 and 2 respectively. The Stern-Volmer quenching constants obtained from a luminescence study for both the complexes are 5.6 × 10(4) M(-1) and 1.6 × 10(4) M(-1) respectively. The dioxomolybdenum(VI) complex is found to be a more potent radioprotector compared to the dioxotungsten(VI) complex and the ligand. Radical scavenging chemical studies suggest that the complexes have a greater ability to scavenge both the hydroxyl as well as the superoxide radicals compared to the ligand. The free radical scavenging ability of the ligand and the complexes was further established by EPR spectroscopy using a stable free radical, the DPPH, as a probe. The experimental results of DNA binding are further supported by molecular docking studies.

Bacterial iron transport: coordination properties of azotobactin, the highly fluorescent siderophore of Azotobacter vinelandii.

PubMed

Palanché, Tania; Blanc, Sylvie; Hennard, Christophe; Abdallah, Mohamed A; Albrecht-Gary, Anne-Marie

2004-02-09

Azotobacter vinelandii, a nitrogen-fixing soil bacterium, secretes in iron deficiency azotobactin delta, a highly fluorescent pyoverdin-like chromopeptidic hexadentate siderophore. The chromophore, derived from 2,3-diamino-6,7 dihydroxyquinoline, is bound to a peptide chain of 10 amino acids: (L)-Asp-(D)-Ser-(L)-Hse-Gly-(D)-beta-threo-HOAsp-(L)-Ser-(D)-Cit-(L)-Hse-(L)-Hse lactone-(D)-N(delta)-Acetyl, N(delta)-HOOrn. Azotobactin delta has three different iron(III) binding sites which are one hydroxamate group at the C-terminal end of the peptidic chain (N(delta)-Acetyl, N(delta)-HOOrn), one alpha-hydroxycarboxylic function in the middle of the chain (beta-threo-hydroxyaspartic acid), and one catechol group on the chromophore. The coordination properties of its iron(III) and iron(II) complexes were measured by spectrophotometry, potentiometry, and voltammetry after the determination of the acid-base functions of the uncomplexed free siderophore. Strongly negatively charged ferric species were observed at neutral p[H]'s corresponding to a predominant absolute configuration Lambda of the ferric complex in solution as deduced from CD measurements. The presence of an alpha-hydroxycarboxylic chelating group does not decrease the stability of the iron(III) complex when compared to the main trishydroxamate siderophores or to pyoverdins. The value of the redox potential of ferric azotobactin is highly consistent with a reductive step by physiological reductants for the iron release. Formation and dissociation kinetics of the azotobactin delta ferric complex point out that both ends of this long siderophore chain get coordinated to Fe(III) before the middle. The most striking result provided by fluorescence measurements is the lasting quenching of the fluorophore in the course of the protonation of the ferric azotobactin delta complex. Despite the release of the hydroxyacid and of the catechol, the fluorescence remains indeed quenched, when iron(III) is bound only to the hydroxamic acid, suggesting a folded conformation at this stage, around the metal ion, in contrast to the unfolded species observed for other siderophores such as ferrioxamine or pyoverdin PaA.

Functional differences in epigenetic modulators-superiority of mercaptoacetamide-based histone deacetylase inhibitors relative to hydroxamates in cortical neuron neuroprotection studies.

PubMed

Kozikowski, Alan P; Chen, Yufeng; Gaysin, Arsen; Chen, Bin; D'Annibale, Melissa A; Suto, Carla M; Langley, Brett C

2007-06-28

We compare the ability of two structurally different classes of epigenetic modulators, namely, histone deacetylase (HDAC) inhibitors containing either a hydroxamate or a mercaptoacetamide as the zinc binding group, to protect cortical neurons in culture from oxidative stress-induced death. This study reveals that some of the mercaptoacetamide-based HDAC inhibitors are fully protective, whereas the hydroxamates show toxicity at higher concentrations. Our present results appear to be consistent with the possibility that the mercaptoacetamide-based HDAC inhibitors interact with a different subset of the HDAC isozymes [less activity at HDAC1 and 2 correlates with less inhibitor toxicity], or alternatively, are interacting selectively with only the cytoplasmic HDACs that are crucial for protection from oxidative stress.

Synthesis and structure of a heptanuclear nickel(II) complex uniquely exhibiting four distinct binding modes, two of which are novel, for a hydroxamate ligand.

PubMed

Gaynor, Declan; Starikova, Zoya A; Ostrovsky, Sergei; Haase, Wolfgang; Nolan, Kevin B

2002-03-07

The reaction of 2-(dimethylamino)phenylhydroxamic acid (2-dmAphaH) with NiSO(4).6H2O gives the complex [Ni7(2-dmAphaH-1)2(2-dmApha)8(H2O)2]SO(4).15H2O uniquely exhibiting four distinct hydroxamate binding modes, two of which are novel, and showing both antiferromagnetic and ferromagnetic interactions in contrast to [Cu5(2-dmAphaH-1)4(HSO4)2(MeOH)2].2MeOH, a strongly antiferromagnetic metallacrown formed with CuSO(4).5H2O.

Effects of the microbial siderophore DFO-B on Pb and Cd speciation in aqueous solution.

PubMed

Mishra, Bhoopesh; Haack, Elizabeth A; Maurice, Patricia A; Bunker, Bruce A

2009-01-01

This study investigates the complexation environments of aqueous Pb and Cd in the presence of the trihydroxamate microbial siderophore, desferrioxamine-B (DFO-B) as a function of pH. Complexation of aqueous Pb and Cd with DFO-B was predicted using equilibrium speciation calculation. Synchrotron-based X-ray absorption fine structure (XAFS) spectroscopy at Pb L(III) edge and Cd K edge was used to characterize Pb and Cd-DFO-B complexes at pH values predicted to best represent each of the metal-siderophore complexes. Pb was not found to be complexed measurably by DFO-B at pH 3.0, but was complexed by all three hydroxamate groups to form a totally "caged" hexadentate structure at pH 7.5-9.0. At the intermediate pH value (pH 4.8), a mixture of Pb-DFOB complexes involving binding of the metal through one and two hydroxamate groups was observed. Cd, on the other hand, remained as hydrated Cd2+ at pH 5.0, occurred as a mixture of Cd-DFOB and inorganic species at pH 8.0, and was bound by three hydroxamate groups from DFO-B at pH 9.0. Overall, the solution species observed with EXAFS were consistent with those predicted thermodynamically. However, Pb speciation at higher pH values differed from that predicted and suggests that published constants underestimate the binding constant for complexation of Pb with all three hydroxamate groups of the DFO-B ligand. This molecular-level understanding of metal-siderophore solution coordination provides physical evidence for complexes of Pb and Cd with DFO-B, and is an important first step toward understanding processes at the microbial- and/or mineral-water interface in the presence of siderophores.

Carboxylic acid isosteres improve the activity of ring-fused 2-pyridones that inhibit pilus biogenesis in E. coli

PubMed Central

Åberg, Veronica; Das, Pralay; Chorell, Erik; Hedenström, Mattias; Pinkner, Jerome S.; Hultgren, Scott J.; Almqvist, Fredrik

2009-01-01

Ring-fused 2-pyridones, termed pilicides, are small synthetic compounds that inhibit pilus assembly in uropathogenic E. coli. Their biological activity is clearly dependent upon a carboxylic acid functionality. Here we present the synthesis and biological evaluation of carboxylic acid isosteres, including e.g. tetrazoles, acyl sulfonamides and hydroxamic acids, of two lead 2-pyridones. Two independent biological evaluations show that acyl sulfonamides and tetrazoles significantly improve pilicide activity against uropathogenic E. coli. PMID:18499455

Metabolism of 4-Chloronitrobenzene by the Yeast Rhodosporidium sp

PubMed Central

Corbett, Michael D.; Corbett, Bernadette R.

1981-01-01

The yeast Rhodosporidium sp. metabolized 4-chloronitrobenzene by a reductive pathway to give 4-chloroacetanilide and 4-chloro-2-hydroxyacetanilide as the major final metabolites. The intermediate production of 4-chloronitrosobenzene, 4-chlorophenylhydroxylamine, and 4-chloroaniline was demonstrated by high-pressure liquid chromatography. Additional studies with selected metabolites established that the metabolite 4-chloro-2-hydroxyacetanilide was produced by an initial Bamberger rearrangement of the hydroxylamine metabolite, followed by acetylation. Direct C hydroxylation of the aromatic ring was not observed in this species. No hydroxamic acid production was detected, even though significant concentrations of the nitroso and hydroxylamine precursors to this functional group were observed. PMID:16345757

Quinolone-based HDAC inhibitors.

PubMed

Balasubramanian, Gopalan; Kilambi, Narasimhan; Rathinasamy, Suresh; Rajendran, Praveen; Narayanan, Shridhar; Rajagopal, Sridharan

2014-08-01

HDAC inhibitors emerged as promising drug candidates in combating wide variety of cancers. At present, two of the compounds SAHA and Romidepsin were approved by FDA for cutaneous T-cell lymphoma and many are in various clinical phases. A new quinolone cap structure was explored with hydroxamic acid as zinc-binding group (ZBG). The pan HDAC inhibitory and antiproliferative activities against three human cancer cell lines HCT-116 (colon), NCI-H460 (lung) and U251 (glioblastoma) of the compounds (4a-4w) were evaluated. Introduction of heterocyclic amines in CAP region increased the enzyme inhibitory and antiproliferative activities and few of the compounds tested are metabolically stable in both MLM and HLM.

Iron chelated cyclic peptide, ferrichrysin, for oral treatment of iron deficiency: solution properties and efficacy in anemic rats.

PubMed

Suzuki, Sachiko; Fukuda, Katsuharu; Irie, Motoko; Hata, Yoji

2007-01-01

Ferrichrysin (Fcy), which is produced by Aspergillus oryzae and is present in foods used for human consumption, belongs to a group of hydroxamate siderophore ferric iron chelators. Fcy (100 mg/mL) dissolves completely at both pH 2.0 and 7.0, being very stable at a wide range of pH, high temperatures and pressures, with little reactivity to dietary iron absorption inhibitors, phytic acid, tannic acid, and catechin. We studied the effect of Fcy in male Sprague-Dawley rats with iron-deficiency anemia, which were separated into three different dietary groups (n=5) and supplementing diets as follows: (i) ferric citrate, (ii) heme iron concentrate, and (iii) Fcy (35 mg Fe/kg diet) for three weeks. Fcy exhibited the same beneficial effect in improving iron deficiency anemia as ferric citrate, being significantly greater than the effect of heme iron. The iron concentration of liver in the Fcy group was 35% greater than that in the ferric citrate group. These findings indicate that Fcy could be an efficient oral iron supplement to prevent or treat iron deficiency.

Interaction of solid organic acids with carbon nanotube field effect transistors

NASA Astrophysics Data System (ADS)

Klinke, Christian; Afzali, Ali; Avouris, Phaedon

2006-10-01

A series of solid organic acids were used to p-dope carbon nanotubes. The extent of doping is shown to be dependent on the pKa value of the acids. Highly fluorinated carboxylic acids and sulfonic acids are very effective in shifting the threshold voltage and making carbon nanotube field effect transistors to be more p-type devices. Weaker acids like phosphonic or hydroxamic acids had less effect. The doping of the devices was accompanied by a reduction of the hysteresis in the transfer characteristics. In-solution doping survives standard fabrication processes and renders p-doped carbon nanotube field effect transistors with good transport characteristics.

Development of Matrix Metalloproteinase-2 Inhibitors for Cardioprotection

PubMed Central

Bencsik, Péter; Kupai, Krisztina; Görbe, Anikó; Kenyeres, Éva; Varga, Zoltán V.; Pálóczi, János; Gáspár, Renáta; Kovács, László; Weber, Lutz; Takács, Ferenc; Hajdú, István; Fabó, Gabriella; Cseh, Sándor; Barna, László; Csont, Tamás; Csonka, Csaba; Dormán, György; Ferdinandy, Péter

2018-01-01

The objective of our present study is to develop novel inhibitors for MMP-2 for acute cardioprotection. In a series of pilot studies, novel substituted carboxylic acid derivatives were synthesized based on imidazole and thiazole scaffolds and then tested in a screeening cascade for MMP inhibition. We found that the MMP-inhibiting effects of imidazole and thiazole carboxylic acid-based compounds are superior in efficacy in comparison to the conventional hydroxamic acid derivatives of the same molecules. Based on these results, a 568-membered focused library of imidazole and thiazole compounds was generated in silico and then the library members were docked to the 3D model of MMP-2 followed by an in vitro medium throughput screening (MTS) based on a fluorescent assay employing MMP-2 catalytic domain. Altogether 45 compounds showed a docking score of >70, from which 30 compounds were successfully synthesized. Based on the MMP-2 inhibitory tests using gelatin zymography, 7 compounds were then selected and tested in neonatal rat cardiac myocytes subjected to simulated I/R injury. Six compounds showed significant cardio-cytoprotecion and the most effective compound (MMPI-1154) significantly decreased infarct size when applied at 1 μM in an ex vivo model for acute myocardial infarction. This is the first demonstration that imidazole and thiazole carboxylic acid-based compounds are more efficacious MMP-2 inhibitor than their hydroxamic acid derivatives. MMPI-1154 is a promising novel cardio-cytoprotective imidazole-carboxylic acid MMP-2 inhibitor lead candidate for the treatment of acute myocardial infarction. PMID:29674965

Altering histone acetylation status in donor cells with suberoylanilide hydroxamic acid does not affect dog cloning efficiency.

PubMed

Kim, Min Jung; Oh, Hyun Ju; Kim, Geon A; Suh, Han Na; Jo, Young Kwang; Choi, Yoo Bin; Kim, Dong Hoon; Han, Ho Jae; Lee, Byeong Chun

2015-10-15

Although dog cloning technology has been applied to conservation of endangered canids, propagation of elite dogs, and production of transgenic dogs, the efficiency of cloning is still very low. To help overcome this problem, we evaluated the effect of treating donor cells with suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, on dog cloning efficiency. Relative messenger RNA expressions of the bax1/bcl2 ratio and Dnmt1 in fibroblasts treated with different concentrations (0, 1, 10, 50 μM) of SAHA and durations (0, 20, 44 hours) were compared. Treatment with 1 μM for 20 hours showed significantly lower bax1/bcl2 and Dnmt1 transcript abundance. Acetylation of H3K9 was significantly increased after SAHA treatment, but H4K5, H4K8 and H4K16 were not changed. After SCNT using control or donor cells treated with SAHA, a total of 76 and 64 cloned embryos were transferred to seven and five recipients, respectively. Three fetuses were diagnosed in both control and SAHA-treated groups by ultrasonography 29 days after the embryo transfer, but there was no significant difference in the pregnancy rate (4.2% vs. 4.3%). In conclusion, although SAHA treatment as used in this study significantly decreased bax1/bcl2 and Dnmt1 transcripts of donor nuclei, as well as increased H3 acetylation, it was not enough to increase in vivo developmental competence of cloned dog embryos. Copyright © 2015 Elsevier Inc. All rights reserved.

Histone deacetylase inhibitors selectively suppress expression of HDAC7.

PubMed

Dokmanovic, Milos; Perez, Gisela; Xu, Weisheng; Ngo, Lang; Clarke, Cathy; Parmigiani, Raphael B; Marks, Paul A

2007-09-01

There are 18 histone deacetylases (HDAC) generally divided into four classes based on homology to yeast HDACs. HDACs have many protein substrates in addition to histones that are involved in regulation of gene expression, cell proliferation, and cell death. Inhibition of HDACs can cause accumulation of acetylated forms of these proteins, thus altering their function. HDAC inhibitors (HDACi), such as the hydroxamic acid-based vorinostat (suberoylanilide hydroxamic acid), inhibit the zinc-containing classes I, II, and IV, but not the NAD(+)-dependent class III, enzymes. HDACis are a group of novel anticancer agents. Vorinostat is the first HDACi approved for clinical use in the treatment of the cancer cutaneous T-cell lymphoma. Factors affecting expression of HDACs are not well understood. This study focuses on the effect of the HDACi vorinostat on the expression of class I and class II HDACs. We found that vorinostat selectively down-regulates HDAC7 with little or no effect on the expression of other class I or class II HDACs. Fourteen cell lines were examined, including normal, immortalized, genetically transformed, and human cancer-derived cell lines. Down-regulation of HDAC7 by vorinostat is more pronounced in transformed cells sensitive to inhibitor-induced cell death than in normal cells or cancer cells resistant to induced cell death. Modulation of HDAC7 levels by small interfering RNA-mediated knockdown or by HDAC7 overexpression is associated with growth arrest but without detectable changes in acetylation of histones or p21 gene expression. Selective down-regulation of HDAC7 protein may serve as a marker of response of tumors to HDACi.

Nanostructured delivery system for Suberoylanilide hydroxamic acid against lung cancer cells.

PubMed

Sankar, Renu; Karthik, Selvaraju; Subramanian, Natesan; Krishnaswami, Venkateshwaran; Sonnemann, Jürgen; Ravikumar, Vilwanathan

2015-06-01

With the objective to provide a potential approach for the treatment of lung cancer, nanotechnology based Suberoylanilide hydroxamic acid (SAHA)-loaded Poly-d, l-lactide-co glycolide (PLGA) nanoparticles have been formulated using the nanoprecipitation technique. The acquired nanoparticles were characterized by various throughput techniques and the analyses showed the presence of smooth and spherical shaped SAHA-loaded PLGA nanoparticles, with an encapsulation efficiency of 44.8% and a particle size of 208nm. The compatibility between polymer and drug in the formulation was tested using FT-IR, Micro-Raman spectrum and DSC thermogram analyses, revealing a major interaction between the drug and polymer. The in vitro drug release from the SAHA-loaded PLGA nanoparticles was found to be biphasic with an initial burst followed by a sustained release for up to 50h. In experiments using the lung cancer cell line A549, SAHA-loaded PLGA nanoparticles demonstrated a superior antineoplastic activity over free SAHA. In conclusion, SAHA-loaded PLGA nanoparticles may be a useful novel approach for the treatment of lung cancer. Copyright © 2015. Published by Elsevier B.V.

LBH589, A Hydroxamic Acid-Derived HDAC Inhibitor, is Neuroprotective in Mouse Models of Huntington’s Disease

PubMed Central

Chopra, Vanita; Quinti, Luisa; Khanna, Prarthana; Paganetti, Paolo; Kuhn, Rainer; Young, Anne B.; Kazantsev, Aleksey G.; Hersch, Steven

2016-01-01

Background: Modulation of gene transcription by HDAC inhibitors has been shown repeatedly to be neuroprotective in cellular, invertebrate, and rodent models of Huntington’s disease (HD). It has been difficult to translate these treatments to the clinic, however, because existing compounds have limited potency or brain bioavailability. Objective: In the present study, we assessed the therapeutic potential of LBH589, an orally bioavailable hydroxamic acid-derived nonselective HDAC inhibitor in mouse models of HD. Method: The efficacy of LBH589 is tested in two HD mouse models using various biochemical, behavioral and neuropathological outcome measures. Results: We show that LBH589 crosses the blood brain barrier; induces histone hyperacetylation and prevents striatal neuronal shrinkage in R6/2 HD mice. In full-length knock-in HD mice LBH589-treatment improves motor performance and reduces neuronal atrophy. Conclusions: Our efficacious results of LBH589 in fragment and full-length mouse models of HD suggest that LBH589 is a promising candidate for clinical assessment in HD patients and provides confirmation that non-selective HDAC inhibitors can be viable clinical candidates. PMID:27983565

Influence of natural and synthetic histone deacetylase inhibitors on chromatin.

PubMed

Licciardi, Paul V; Kwa, Faith A A; Ververis, Katherine; Di Costanzo, Natasha; Balcerczyk, Aneta; Tang, Mimi L; El-Osta, Assam; Karagiannis, Tom C

2012-07-15

Histone deacetylase inhibitors (HDACIs) have emerged as a new class of anticancer therapeutics. The hydroxamic acid, suberoylanilide hydroxamic acid (Vorinostat, Zolinza™), and the cyclic peptide, depsipeptide (Romidepsin, Istodax™), were approved by the U.S. Food and Drug Administration (FDA) for the treatment of cutaneous T-cell lymphoma in 2006 and 2009, respectively. At least 15 HDACIs are currently undergoing clinical trials either alone or in combination with other therapeutic modalities for the treatment of numerous hematological and solid malignancies. The potential utility of HDACIs has been extended to nononcologic applications, including autoimmune disorders, inflammation, diseases of the central nervous system, and malaria. Given the promise of HDACIs, there is growing interest in the potential of dietary compounds that possess HDAC inhibition activity. This review is focused on the identification of and recent findings with HDACIs from dietary, medicinal plant, and microbial sources. We discuss the mechanisms of action and clinical potential of natural HDACIs. Apart from identification of further HDACI compounds from dietary sources, further research will be aimed at understanding the effects on gene regulation on lifetime exposure to these compounds. Another important issue that requires clarification.

Epigenetic therapy potential of suberoylanilide hydroxamic acid on invasive human non-small cell lung cancer cells.

PubMed

Zhang, Shirong; Wu, Kan; Feng, Jianguo; Wu, Zhibing; Deng, Qinghua; Guo, Chao; Xia, Bing; Zhang, Jing; Huang, Haixiu; Zhu, Lucheng; Zhang, Ke; Shen, Binghui; Chen, Xufeng; Ma, Shenglin

2016-10-18

Metastasis is the reason for most cancer death, and a crucial primary step for cancer metastasis is invasion of the surrounding tissue, which may be initiated by some rare tumor cells that escape the heterogeneous primary tumor. In this study, we isolated invasive subpopulations of cancer cells from human non-small cell lung cancer (NSCLC) H460 and H1299 cell lines, and determined the gene expression profiles and the responses of these invasive cancer cells to treatments of ionizing radiation and chemotherapeutic agents. The subpopulation of highly invasive NSCLC cells showed epigenetic signatures of epithelial-mesenchymal transition, cancer cell stemness, increased DNA damage repair and cell survival signaling. We also investigated the epigenetic therapy potential of suberoylanilide hydroxamic acid (SAHA) on invasive cancer cells, and found that SAHA suppresses cancer cell invasiveness and sensitizes cancer cells to treatments of IR and chemotherapeutic agents. Our results provide guidelines for identification of metastatic predictors and for clinical management of NSCLC. This study also suggests a beneficial clinical potential of SAHA as a chemotherapeutic agent for NSCLC patients.

Selective matrix metalloproteinase inhibitor, N-biphenyl sulfonyl phenylalanine hydroxamic acid, inhibits the migration of CD4+ T lymphocytes in patients with HTLV-I-associated myelopathy.

PubMed

Ikegami, Mayumi; Umehara, Fujio; Ikegami, Naohito; Maekawa, Ryuji; Osame, Mitsuhiro

2002-06-01

Matrix metalloproteinases (MMPs) have been reported to be involved in various inflammatory disorders. Previous studies revealed that MMP-2 and MMP-9 might play important roles in the breakdown of the blood-brain barrier (BBB) in the central nervous system (CNS) of patients with HTLV-I-associated myelopathy (HAM)/tropical spastic paraparesis (TSP). N-Biphenyl sulfonyl-phenylalanine hydroxamic acid (BPHA) selectively inhibits MMP-2, -9 and -14, but not MMP-1, -3 and -7. In the present study, we examined whether or not the selective MMP inhibitor BPHA could inhibit the heightened migrating activity of CD4+ T cells in HAM/TSP patients. The migration assay using an invasion chamber showed that migration of CD4+ T cells in HAM/TSP patients was inhibited by 25 microM BPHA. In addition, the inhibitory ratio of migrating CD4+ lymphocytes was higher in HAM patients compared to normal controls. These results suggest that the selective MMP inhibitor BPHA has therapeutic potential for HAM/TSP.

LBH589, A Hydroxamic Acid-Derived HDAC Inhibitor, is Neuroprotective in Mouse Models of Huntington's Disease.

PubMed

Chopra, Vanita; Quinti, Luisa; Khanna, Prarthana; Paganetti, Paolo; Kuhn, Rainer; Young, Anne B; Kazantsev, Aleksey G; Hersch, Steven

2016-12-15

Modulation of gene transcription by HDAC inhibitors has been shown repeatedly to be neuroprotective in cellular, invertebrate, and rodent models of Huntington's disease (HD). It has been difficult to translate these treatments to the clinic, however, because existing compounds have limited potency or brain bioavailability. In the present study, we assessed the therapeutic potential of LBH589, an orally bioavailable hydroxamic acid-derived nonselective HDAC inhibitor in mouse models of HD. The efficacy of LBH589 is tested in two HD mouse models using various biochemical, behavioral and neuropathological outcome measures. We show that LBH589 crosses the blood brain barrier; induces histone hyperacetylation and prevents striatal neuronal shrinkage in R6/2 HD mice. In full-length knock-in HD mice LBH589-treatment improves motor performance and reduces neuronal atrophy. Our efficacious results of LBH589 in fragment and full-length mouse models of HD suggest that LBH589 is a promising candidate for clinical assessment in HD patients and provides confirmation that non-selective HDAC inhibitors can be viable clinical candidates.

Isolation of an iron-binding compound from Pseudomonas aeruginosa.

PubMed Central

Cox, C D; Graham, R

1979-01-01

An iron-binding compound was isolated from ethyl acetate extracts of culture supernatant fluids of Pseudomonas aeruginosa and was purified by successive paper and thin-layer chromatographic procedures. The purified compound was characterized by UV, visible, infrared, and fluorescence spectroscopy. The compound possesses phenolic characteristics, with little or no similarity to dihydroxybenzoates and no indication of a hydroxamate group. P. aeruginosa synthesized the compound during active growth in culture media containing less than 5 X 10(-6) M added FeCl3. When added to iron-poor cultures of P. aeruginosa, the compound promoted the growth of the bacterium and also reversed growth inhibition by the iron chelator ethylenediamine-di-(o-hydroxyphenylacetic acid). PMID:104968

Design, synthesis and biological evaluation of bisthiazole-based trifluoromethyl ketone derivatives as potent HDAC inhibitors with improved cellular efficacy.

PubMed

Gong, Chao-Jun; Gao, An-Hui; Zhang, Yang-Ming; Su, Ming-Bo; Chen, Fei; Sheng, Li; Zhou, Yu-Bo; Li, Jing-Ya; Li, Jia; Nan, Fa-Jun

2016-04-13

Histone deacetylases (HDACs) are a class of epigenetic modulators with complex functions in histone post-translational modifications and are well known targets for antineoplastic drugs. We have previously developed a series of bisthiazole-based hydroxamic acids as novel potent HDAC inhibitors. In the present work, a new series of bisthiazole-based compounds with different zinc binding groups (ZBGs) have been designed and synthesized. Among them is compound 7, containing a trifluoromethyl ketone as the ZBG, which displays potent inhibitory activity towards human HDACs and improved antiproliferative activity in several cancer cell lines. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Chemical heterogeneity as a result of hydroxylamine cleavage of a fusion protein of human insulin-like growth factor I.

PubMed Central

Canova-Davis, E; Eng, M; Mukku, V; Reifsnyder, D H; Olson, C V; Ling, V T

1992-01-01

Recombinant DNA techniques were used to biosynthesize human insulin-like growth factor I (hIGF-I) as a fusion protein wherein the fusion polypeptide is an IgG-binding moiety derived from staphylococcal protein A. This fusion protein is produced in Escherichia coli and secreted into the fermentation broth. In order to release mature recombinant-derived hIGF-I (rhIGF-I), the fusion protein is treated with hydroxylamine, which cleaves a susceptible Asn-Gly bond that has been engineered into the fusion protein gene. Reversed-phase h.p.l.c. was used to estimate the purity of the rhIGF-I preparations, especially for the quantification of the methionine sulphoxide-containing variant. It was determined that hydroxylamine cleavage of the fusion protein produced, as a side reaction, hydroxamates of the asparagine and glutamine residues in rhIGF-I. Although isoelectric focusing was effective in detecting, and reversed-phase h.p.l.c. for producing enriched fractions of the hydroxamate variants, ion-exchange chromatography was a more definitive procedure, as it allowed quantification and facile removal of these variants. The identity of the variants as hydroxamates was established by Staphylococcus aureus V8 proteinase digestion, followed by m.s., as the modification was transparent to amino acid and N-terminal sequence analyses. The biological activity of rhIGF-I was established by its ability to incorporate [3H]thymidine into the DNA of BALB/c373 cells and by a radioreceptor assay utilizing human placental membranes. Both assays demonstrate that the native, recombinant and methionine sulphoxide and hydroxamate IGF-I variants are essentially equipotent. Images Fig. 2. PMID:1637301

Comparative molecular dynamics simulations of histone deacetylase-like protein: binding modes and free energy analysis to hydroxamic acid inhibitors.

PubMed

Yan, Chunli; Xiu, Zhilong; Li, Xiaohui; Li, Shenmin; Hao, Ce; Teng, Hu

2008-10-01

Histone deacetylases (HDACs) play an important role in gene transcription, and inhibitors of HDACs can induce cell differentiation and suppress cell proliferation in tumor cells. Histone deacetylase1 (HDAC1) binds suberanilohydroxamic acid (SAHA) and 7-phenyl-2, 4, 6-hepta-trienoyl hydroxamic acid (CG-1521) with moderately low affinity (DeltaG = -8.6 and -7.8 kcal mol(-1)). The structurally related (E)-2-(3-(3-(hydroxyamino)-3-oxoprop-1-enyl)phenyl)-N(1),N(3)-diphenylmalonamide (SK-683), a Trichostatin A (TSA)-like HDAC1 inhibitor, and TSA are bound to the HDAC1 with -12.3 and -10.3 kcal mol(-1) of DeltaG, higher binding free energies than SAHA and CG-1521. Histone deacetylase-like protein (HDLP), an HDAC homologue, shows a 35.2% sequence identity of HDLP and human HDAC1. Molecular dynamics simulation and the molecular mechanics/generalized-Born surface area (MM-GBSA) free energy calculations were applied to investigate the factors responsible for the relatively activity of these four inhibitors to HDLP. In addition, computational alanine scanning of the binding site residues was carried out to determine the contribution components from van der Waals, electrostatic interaction, nonpolar and polar energy of solvation as well as the effects of backbones and side-chains with the MM-GBSA method. MM-GBSA methods reproduced the experimental relative affinities of the four inhibitors in good agreement (R(2) = 0.996) between experimental and computed binding energies. The MM-GBSA calculations showed that, the number of hydrogen bonds formed between the HDLP and inhibitors, which varied in the system studied, and electrostatic interactions determined the magnitude of the free energies for HDLP-inhibitor interactions. The MM-GBSA calculations revealed that the binding of HDLP to these four hydroxamic acid inhibitors is mainly driven by van der Waals/nonpolar interactions. This study can be a guide for the optimization of HDAC inhibitors and future design of new therapeutic agents for the treatment of cancer.

Degradation of cytokinins by maize cytokinin dehydrogenase is mediated by free radicals generated by enzymatic oxidation of natural benzoxazinones.

PubMed

Frébortová, Jitka; Novák, Ondrej; Frébort, Ivo; Jorda, Radek

2010-02-01

Hydroxamic acid 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-one (DIMBOA) was isolated from maize phloem sap as a compound enhancing the degradation of isopentenyl adenine by maize cytokinin dehydrogenase (CKX), after oxidative conversion by either laccase or peroxidase. Laccase and peroxidase catalyze oxidative cleavage of DIMBOA to 4-nitrosoresorcinol-1-monomethyl ether (coniferron), which serves as a weak electron acceptor of CKX. The oxidation of DIMBOA and coniferron generates transitional free radicals that are used by CKX as effective electron acceptors. The function of free radicals in the CKX-catalyzed reaction was also verified with a stable free radical of 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid. Application of exogenous cytokinin to maize seedlings resulted in an enhanced benzoxazinoid content in maize phloem sap. The results indicate a new function for DIMBOA in the metabolism of the cytokinin group of plant hormones.

N-Alkyl Urea Hydroxamic Acids as a New Class of Peptide Deformylase Inhibitors with Antibacterial Activity

PubMed Central

Hackbarth, Corinne J.; Chen, Dawn Z.; Lewis, Jason G.; Clark, Kirk; Mangold, James B.; Cramer, Jeffrey A.; Margolis, Peter S.; Wang, Wen; Koehn, Jim; Wu, Charlotte; Lopez, S.; Withers III, George; Gu, Helen; Dunn, Elina; Kulathila, R.; Pan, Shi-Hao; Porter, Wilma L.; Jacobs, Jeff; Trias, Joaquim; Patel, Dinesh V.; Weidmann, Beat; White, Richard J.; Yuan, Zhengyu

2002-01-01

Peptide deformylase (PDF) is a prokaryotic metalloenzyme that is essential for bacterial growth and is a new target for the development of antibacterial agents. All previously reported PDF inhibitors with sufficient antibacterial activity share the structural feature of a 2-substituted alkanoyl at the P1′ site. Using a combination of iterative parallel synthesis and traditional medicinal chemistry, we have identified a new class of PDF inhibitors with N-alkyl urea at the P1′ site. Compounds with MICs of ≤4 μg/ml against gram-positive and gram-negative pathogens, including Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae, have been identified. The concentrations needed to inhibit 50% of enzyme activity (IC50s) for Escherichia coli Ni-PDF were ≤0.1 μM, demonstrating the specificity of the inhibitors. In addition, these compounds were very selective for PDF, with IC50s of consistently >200 μM for matrilysin and other mammalian metalloproteases. Structure-activity relationship analysis identified preferred substitutions resulting in improved potency and decreased cytotoxity. One of the compounds (VRC4307) was cocrystallized with PDF, and the enzyme-inhibitor structure was determined at a resolution of 1.7 Å. This structural information indicated that the urea compounds adopt a binding position similar to that previously determined for succinate hydroxamates. Two compounds, VRC4232 and VRC4307, displayed in vivo efficacy in a mouse protection assay, with 50% protective doses of 30.8 and 17.9 mg/kg of body weight, respectively. These N-alkyl urea hydroxamic acids provide a starting point for identifying new PDF inhibitors that can serve as antimicrobial agents. PMID:12183225

Studies of benzamide- and thiol-based histone deacetylase inhibitors in models of oxidative-stress-induced neuronal death: identification of some HDAC3-selective inhibitors.

PubMed

Chen, Yufeng; He, Rong; Chen, Yihua; D'Annibale, Melissa A; Langley, Brett; Kozikowski, Alan P

2009-05-01

We compare three structurally different classes of histone deacetylase (HDAC) inhibitors that contain benzamide, hydroxamate, or thiol groups as the zinc binding group (ZBG) for their ability to protect cortical neurons in culture from cell death induced by oxidative stress. This study reveals that none of the benzamide-based HDAC inhibitors (HDACIs) provides any neuroprotection whatsoever, in distinct contrast to HDACIs that contain other ZBGs. Some of the sulfur-containing HDACIs, namely the thiols, thioesters, and disulfides present modest neuroprotective activity but show toxicity at higher concentrations. Taken together, these data demonstrate that the HDAC6-selective mercaptoacetamides that were reported previously provide the best protection in the homocysteic acid model of oxidative stress, thus further supporting their study in animal models of neurodegenerative diseases.

Endogenous sulfur dioxide aggravates myocardial injury in isolated rat heart with ischemia and reperfusion.

PubMed

Zhang, Suqing; Du, Junbao; Jin, Hongfang; Li, Wei; Liang, Yinfang; Geng, Bin; Li, Shukui; Zhang, Chunyu; Tang, Chaoshu

2009-02-27

Ischemia-reperfusion (I/R) injury is an important clinical problem. This article investigated the role of sulfur dioxide (SO2) in the regulation of cardiac function and in the pathogenesis of cardiac I/R injury in isolated rat heart. Rat hearts isolated on a Langendorff apparatus were divided into control, I/R, I/R+SO2, and I/R+hydroxamate groups. Hydroxamate is an inhibitor of SO2 synthetase. I/R treatment was ischemia for 2 hr in hypothermic solution (4 degrees C), then reperfusion/rewarming (37 degrees C) for 60 min. Cardiac function was monitored by MacLab analog to a digital converter. Determination of sulfite content involved reverse-phase high performance liquid chromatography with fluorescence detection. Myoglobin content of coronary perfusate was determined at 410 nm. Myocardial malondialdehyde (MDA) was determined by thiobarbituric acid method, and conjugated diene (CD) was extracted by chloroform. 5,50-Dithiobis-2-nitrobenzoic acid was used to determine glutathione (GSH). The results showed that I/R treatment obviously increased myocardial sulfite content, and sulfite content of myocardium was negatively correlated with the recovery rate of left-ventricle developed pressure and positively correlated with the leakage of myoglobin. In postreperfusion, myocardial function recovery was decreased by SO2. During reperfusion, myocardium-released enzymes, MDA and CD level were increased but myocardial GSH content was depressed with the treatment of SO2 donor. Incubation of myocardial tissue with SO2 significantly increased MDA and CD generation. Endogenous SO2 might be involved in the pathogenesis of myocardial I/R injury, and its mechanism might be associated with an increase in lipid peroxide level and a decrease in GSH generation.

Pyridone Methylsulfone Hydroxamate LpxC Inhibitors for the Treatment of Serious Gram-Negative Infections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Montgomery, Justin I.; Brown, Matthew F.; Reilly, Usa

The synthesis and biological activity of a new series of LpxC inhibitors represented by pyridone methylsulfone hydroxamate 2a is presented. Members of this series have improved solubility and free fraction when compared to compounds in the previously described biphenyl methylsulfone hydroxamate series, and they maintain superior Gram-negative antibacterial activity to comparator agents.

Photometric microdetermination of malathion

USGS Publications Warehouse

Kallman, B.J.

1962-01-01

Carboxylic esters and lactones react with alkaline hydroxylamine to yield hydroxamates; these in acidic solution form colored iron(III) complexes. A photometric determination of such esters and lactones is thus permitted and has been extensively applied ( I-6). Hestrin ( 3) utilized this method for the microdetermination of acetylcholine and his procedure is much used for the in vitro study of cholinesterase activity and inhibition (4-6).

The discovery of novel tartrate-based TNF-[alpha] converting enzyme (TACE) inhibitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosner, Kristin E.; Guo, Zhuyan; Orth, Peter

2010-09-17

A novel series of TNF-{alpha} convertase (TACE) inhibitors which are non-hydroxamate have been discovered. These compounds are bis-amides of L-tartaric acid (tartrate) and coordinate to the active site zinc in a tridentate manner. They are selective for TACE over other MMP's. We report the first X-ray crystal structure for a tartrate-based TACE inhibitor.

Suberoylanilide hydroxamic acid increases progranulin production in iPSC-derived cortical neurons of frontotemporal dementia patients.

PubMed

Almeida, Sandra; Gao, Fuying; Coppola, Giovanni; Gao, Fen-Biao

2016-06-01

Mutations in the granulin (GRN) gene cause frontotemporal dementia (FTD) due to progranulin haploinsufficiency. Compounds that can increase progranulin production and secretion may be considered as potential therapeutic drugs; however, very few of them have been directly tested on human cortical neurons. To this end, we differentiated 9 induced pluripotent stem cell lines derived from a control subject, a sporadic FTD case and an FTD patient with progranulin S116X mutation. Treatment with 1 μM suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, increased the production of progranulin in cortical neurons of all subjects at both the mRNA and protein levels without affecting their viability. Microarray analysis revealed that SAHA treatment not only reversed some gene expression changes caused by progranulin haploinsufficiency but also caused massive alterations in the overall transcriptome. Thus, histone deacetylase inhibitors may be considered as therapeutic drugs for GRN mutation carriers. However, this class of drugs also causes drastic changes in overall gene expression in human cortical neurons and their side effects and potential impacts on other pathways should be carefully evaluated. Copyright © 2016 Elsevier Inc. All rights reserved.

Histone Deacetylase Inhibitors: An Attractive Therapeutic Strategy Against Breast Cancer.

PubMed

Damaskos, Christos; Garmpis, Nikolaos; Valsami, Serena; Kontos, Michael; Spartalis, Eleftherios; Kalampokas, Theodoros; Kalampokas, Emmanouil; Athanasiou, Antonios; Moris, Demetrios; Daskalopoulou, Afrodite; Davakis, Spyridon; Tsourouflis, Gerasimos; Kontzoglou, Konstantinos; Perrea, Despina; Nikiteas, Nikolaos; Dimitroulis, Dimitrios

2017-01-01

With a lifetime risk estimated to be one in eight in industrialized countries, breast cancer is the most frequent type of cancer among women worldwide. Patients are often treated with anti-estrogens, but it is common that some tumors develop resistance to therapy. The causation and progression of cancer is controlled by epigenetic processes, so there is an ongoing interest in research into mechanisms, genes and signaling pathways associating carcinogenesis with epigenetic modulation of gene expression. Given the fact that histone deacetylases (HDACs) have a great impact on chromatin remodeling and epigenetics, their inhibitors have become a very interesting field of research. This review focused on the use of HDAC inhibitors as anticancer treatment and explains the mechanisms of therapeutic effects on breast cancer. We anticipate further clinical benefits of this new class of drugs, both as single agents and in combination therapy. Molecules such as suberoylanilide hydroxamic acid, trichostatin A, suberoylbis-hydroxamic acid, panobinostat, entinostat, valproic acid, sodium butyrate, SK7041, FTY720, N-(2-hydroxyphenyl)-2-propylpentanamide, Scriptaid, YCW1, santacruzamate A and ferrocenyl have shown promising antitumor effects against breast cancer. HDAC inhibitors consists an attractive field for targeted therapy against breast cancer. Future therapeutic strategies will include combination of HDAC inhibitors and chemotherapy or other inhibitors, in order to target multiple oncogenic signaling pathways. More trials are needed. Copyright© 2017 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Characterization of PAH matrix with monazite stream containing uranium, gadolinium and iron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pal, Sangita, E-mail: sangpal@barc.gov.in; Goswami, D.; Meena, Sher Singh

2016-05-23

Uranium (U) gadolinium (Gd) and iron (Fe) containing alkaline waste simulated effluent (relevant to alkaline effluent of monazite ore) has been treated with a novel amphoteric resin viz, Polyamidehydroxamate (PAH) containing amide and hydroxamic acid groups. The resin has been synthesized in an eco-friendly manner by polymerization nad conversion to functional groups characterized by FT-IR spectra and architectural overview by SEM. Coloration of the loaded matrix and de-coloration after extraction of uranium is the special characteristic of the matrix. Effluent streams have been analyzed by ICP-AES, U loaded PAH has been characterized by FT-IR, EXAFS, Gd and Fe by X-raymore » energy values of EDXRF at 6.053 KeVand 6.405 KeV respectively. The remarkable change has been observed in Mössbauer spectrum of Fe-loaded PAH samples.« less

Recent advances in the discovery of potent and selective HDAC6 inhibitors.

PubMed

Wang, Xiu-Xiu; Wan, Ren-Zhong; Liu, Zhao-Peng

2018-01-01

Histone deacetylase HDAC6, a member of the class IIb HDAC family, is unique among HDAC enzymes in having two active catalytic domains, and has unique physiological function. In addition to the modification of histone, HDAC6 targets specific substrates including α-tubulin and HSP90, and are involved in protein trafficking and degradation, cell shape and migration. Selective HDAC6 inhibitors are an emerging class of pharmaceuticals due to the involvement of HDAC6 in different pathways related to neurodegenerative diseases, cancer, and immunology. Therefore, extensive investigations have been made in the discovery of selective HDAC6 inhibitors. Based on their different zinc binding groups (ZBGs), in this review, HDAC6 inhibitors are grouped as hydroxamic acids, a sulfur containing ZBG based derivatives and other ZBG-derived compounds, and their enzymatic inhibitory activity, selectivity and other biological activities are introduced and summarized. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Selective class IIa histone deacetylase inhibition via a nonchelating zinc-binding group.

PubMed

Lobera, Mercedes; Madauss, Kevin P; Pohlhaus, Denise T; Wright, Quentin G; Trocha, Mark; Schmidt, Darby R; Baloglu, Erkan; Trump, Ryan P; Head, Martha S; Hofmann, Glenn A; Murray-Thompson, Monique; Schwartz, Benjamin; Chakravorty, Subhas; Wu, Zining; Mander, Palwinder K; Kruidenier, Laurens; Reid, Robert A; Burkhart, William; Turunen, Brandon J; Rong, James X; Wagner, Craig; Moyer, Mary B; Wells, Carrow; Hong, Xuan; Moore, John T; Williams, Jon D; Soler, Dulce; Ghosh, Shomir; Nolan, Michael A

2013-05-01

In contrast to studies on class I histone deacetylase (HDAC) inhibitors, the elucidation of the molecular mechanisms and therapeutic potential of class IIa HDACs (HDAC4, HDAC5, HDAC7 and HDAC9) is impaired by the lack of potent and selective chemical probes. Here we report the discovery of inhibitors that fill this void with an unprecedented metal-binding group, trifluoromethyloxadiazole (TFMO), which circumvents the selectivity and pharmacologic liabilities of hydroxamates. We confirm direct metal binding of the TFMO through crystallographic approaches and use chemoproteomics to demonstrate the superior selectivity of the TFMO series relative to a hydroxamate-substituted analog. We further apply these tool compounds to reveal gene regulation dependent on the catalytic active site of class IIa HDACs. The discovery of these inhibitors challenges the design process for targeting metalloenzymes through a chelating metal-binding group and suggests therapeutic potential for class IIa HDAC enzyme blockers distinct in mechanism and application compared to current HDAC inhibitors.

Selective flotation of phosphate minerals with hydroxamate collectors

DOEpatents

Miller, Jan D.; Wang, Xuming; Li, Minhua

2002-01-01

A method is disclosed for separating phosphate minerals from a mineral mixture, particularly from high-dolomite containing phosphate ores. The method involves conditioning the mineral mixture by contacting in an aqueous in environment with a collector in an amount sufficient for promoting flotation of phosphate minerals. The collector is a hydroxamate compound of the formula; ##STR1## wherein R is generally hydrophobic and chosen such that the collector has solubility or dispersion properties it can be distributed in the mineral mixture, typically an alkyl, aryl, or alkylaryl group having 6 to 18 carbon atoms. M is a cation, typically hydrogen, an alkali metal or an alkaline earth metal. Preferably, the collector also comprises an alcohol of the formula, R'--OH wherein R' is generally hydrophobic and chosen such that the collector has solubility or dispersion properties so that it can be distributed in the mineral mixture, typically an alkyl, aryl, or alkylaryl group having 6 to 18 carbon atoms.

Development of iron chelators for Cooley's anemia. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crosby, W.H.; Green, R.

Iron chelators were screened in an iron-loaded rat model using selective radioiron probes. In all experiments, chelators D and F, in that order, induced significant loss of radioiron compared with controls. However, use of chelator D was associated with side effects, and resulted in the death of some animals. There was some evidence that chelator A also caused iron loss significantly greater than controls. Chelators B, C and E were without apparent enhancing effect on radioiron excretion. This was a blind study and the compounds used were A - 2,3-Dihydroxybenzoic acid; B - N,N1-Dimethyladipohydroxamic acid; C - DL-Phenylalanine hydroxamic acid;more » D - Ethylenediamine-N,N1-bis(2-hydroxphenylacetic acid); E - Propionohydroxamic acid; and F - Deferrioxamine B.« less

Identifying Novel Type ZBGs and Nonhydroxamate HDAC Inhibitors Through a SVM Based Virtual Screening Approach.

PubMed

Liu, X H; Song, H Y; Zhang, J X; Han, B C; Wei, X N; Ma, X H; Cui, W K; Chen, Y Z

2010-05-17

Histone deacetylase inhibitors (HDACi) have been successfully used for the treatment of cancers and other diseases. Search for novel type ZBGs and development of non-hydroxamate HDACi has become a focus in current research. To complement this, it is desirable to explore a virtual screening (VS) tool capable of identifying different types of potential inhibitors from large compound libraries with high yields and low false-hit rates similar to HTS. This work explored the use of support vector machines (SVM) combined with our newly developed putative non-inhibitor generation method as such a tool. SVM trained by 702 pre-2008 hydroxamate HDACi and 64334 putative non-HDACi showed good yields and low false-hit rates in cross-validation test and independent test using 220 diverse types of HDACi reported since 2008. The SVM hit rates in scanning 13.56 M PubChem and 168K MDDR compounds are comparable to HTS rates. Further structural analysis of SVM virtual hits suggests its potential for identification of non-hydroxamate HDACi. From this analysis, a series of novel ZBG and cap groups were proposed for HDACi design. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

15N and13C NMR investigation of hydroxylamine-derivatized humic substances

USGS Publications Warehouse

Thorn, K.A.; Arterburn, J.B.; Mikita, M.A.

1992-01-01

Five fulvic and humic acid samples of diverse origins were derivatized with 15N-labeled hydroxylamine and analyzed by liquid-phase 15N NMR spectrometry. The 15N NMR spectra indicated that hydroxylamine reacted similarly with all samples and could discriminate among carbonyl functional groups. Oximes were the major derivatives; resonances attributable to hydroxamic acids, the reaction products of hydroxylamine with esters, and resonances attributable to the tautomeric equilibrium position between the nitrosophenol and monoxime derivatives of quinones, the first direct spectroscopic evidence for quinones, also were evident. The 15N NMR spectra also suggested the presence of nitriles, oxazoles, oxazolines, isocyanides, amides, and lactams, which may all be explained in terms of Beckmann reactions of the initial oxime derivatives. INEPT and ACOUSTIC 15N NMR spectra provided complementary information on the derivatized samples. 13C NMR spectra of derivatized samples indicated that the ketone/quinone functionality is incompletely derivatized with hydroxylamine. ?? 1991 American Chemical Society.

Detoxification of Benzoxazolinone Allelochemicals from Wheat by Gaeumannomyces graminis var. tritici, G. graminis var. graminis, G. graminis var. avenae, and Fusarium culmorum

PubMed Central

Friebe, A.; Vilich, V.; Hennig, L.; Kluge, M.; Sicker, D.

1998-01-01

The ability of phytopathogenic fungi to overcome the chemical defense barriers of their host plants is of great importance for fungal pathogenicity. We studied the role of cyclic hydroxamic acids and their related benzoxazolinones in plant interactions with pathogenic fungi. We identified species-dependent differences in the abilities of Gaeumannomyces graminis var. tritici, Gaeumannomyces graminis var. graminis, Gaeumannomyces graminis var. avenae, and Fusarium culmorum to detoxify these allelochemicals of gramineous plants. The G. graminis var. graminis isolate degraded benzoxazolin-2(3H)-one (BOA) and 6-methoxy-benzoxazolin-2(3H)-one (MBOA) more efficiently than did G. graminis var. tritici and G. graminis var. avenae. F. culmorum degraded BOA but not MBOA. N-(2-Hydroxyphenyl)-malonamic acid and N-(2-hydroxy-4-methoxyphenyl)-malonamic acid were the primary G. graminis var. graminis and G. graminis var. tritici metabolites of BOA and MBOA, respectively, as well as of the related cyclic hydroxamic acids. 2-Amino-3H-phenoxazin-3-one was identified as an additional G. graminis var. tritici metabolite of BOA. No metabolite accumulation was detected for G. graminis var. avenae and F. culmorum by high-pressure liquid chromatography. The mycelial growth of the pathogenic fungi was inhibited more by BOA and MBOA than by their related fungal metabolites. The tolerance of Gaeumannomyces spp. for benzoxazolinone compounds is correlated with their detoxification ability. The ability of Gaeumannomyces isolates to cause root rot symptoms in wheat (cultivars Rektor and Astron) parallels their potential to degrade wheat allelochemicals to nontoxic compounds. PMID:9647804

Suberoylanilide hydroxamic acid sensitizes neuroblastoma to paclitaxel by inhibiting thioredoxin-related protein 14-mediated autophagy.

PubMed

Zhen, Zijun; Yang, Kaibin; Ye, Litong; You, Zhiyao; Chen, Rirong; Liu, Ying; He, Youjian

2017-07-01

Paclitaxel is not as effective for neuroblastoma as most of the front-line chemotherapeutics due to drug resistance. This study explored the regulatory mechanism of paclitaxel-associated autophagy and potential solutions to paclitaxel resistance in neuroblastoma. The formation of autophagic vesicles was detected by scanning transmission electron microscopy and flow cytometry. The autophagy-associated proteins were assessed by western blot. Autophagy was induced and the autophagy-associated proteins LC3-I, LC3-II, Beclin 1, and thioredoxin-related protein 14 (TRP14), were found to be upregulated in neuroblastoma cells that were exposed to paclitaxel. The inhibition of Beclin 1 or TRP14 by siRNA increased the sensitivity of the tumor cells to paclitaxel. In addition, Beclin 1-mediated autophagy was regulated by TRP14. Furthermore, the TRP14 inhibitor suberoylanilide hydroxamic acid (SAHA) downregulated paclitaxel-induced autophagy and enhanced the anticancer effects of paclitaxel in normal control cancer cells but not in cells with upregulated Beclin 1 and TRP14 expression. Our findings showed that paclitaxel-induced autophagy in neuroblastoma cells was regulated by TRP14 and that SAHA could sensitize neuroblastoma cells to paclitaxel by specifically inhibiting TRP14. © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

Suberoylanilide hydroxamic acid treatment reveals crosstalks among proteome, ubiquitylome and acetylome in non-small cell lung cancer A549 cell line.

PubMed

Wu, Quan; Cheng, Zhongyi; Zhu, Jun; Xu, Weiqing; Peng, Xiaojun; Chen, Chuangbin; Li, Wenting; Wang, Fengsong; Cao, Lejie; Yi, Xingling; Wu, Zhiwei; Li, Jing; Fan, Pingsheng

2015-03-31

Suberoylanilide hydroxamic acid (SAHA) is a well-known histone deacetylase (HDAC) inhibitor and has been used as practical therapy for breast cancer and non-small cell lung cancer (NSCLC). It is previously demonstrated that SAHA treatment could extensively change the profile of acetylome and proteome in cancer cells. However, little is known about the impact of SAHA on other protein modifications and the crosstalks among different modifications and proteome, hindering the deep understanding of SAHA-mediated cancer therapy. In this work, by using SILAC technique, antibody-based affinity enrichment and high-resolution LC-MS/MS analysis, we investigated quantitative proteome, acetylome and ubiquitylome as well as crosstalks among the three datasets in A549 cells toward SAHA treatment. In total, 2968 proteins, 1099 acetylation sites and 1012 ubiquitination sites were quantified in response to SAHA treatment, respectively. With the aid of intensive bioinformatics, we revealed that the proteome and ubiquitylome were negatively related upon SAHA treatment. Moreover, the impact of SAHA on acetylome resulted in 258 up-regulated and 99 down-regulated acetylation sites at the threshold of 1.5 folds. Finally, we identified 55 common sites with both acetylation and ubiquitination, among which ubiquitination level in 43 sites (78.2%) was positive related to acetylation level.

8-Hydroxyquinoline and hydroxamic acid inhibitors of botulinum neurotoxin BoNT/A.

PubMed

Dickerson, Tobin J; Smith, Garry R; Pelletier, Jeffrey C; Reitz, Allen B

2014-01-01

We describe here the state of the art of certain aspects concerning potential small molecule therapy directed toward botulism, by inhibition of the zinc-protease containing light chain (LC) of botulinum neurotoxin BoNT/A from the anaerobic bacillus Clostridium botulinum. Botulinum neurotoxins (BoNTs) are comprised of eight serologically-distinct proteins (A - H), several of which are further divided, such as BoNT/A which has five subtypes. The BoNTs are the most toxic substances known to mankind, causing a form of flaccid paralysis that can be rapid and is often lethal. BoNT/A is comprised of a ~100 kDa heavy chain (HC) attached via a single disulfide Cys-Cys bond to a ~50 kDa LC. The HC mediates transport to and uptake by presynaptic glutamatergic neurons, where the LC cleaves the protein SNAP-25 and thus prevents vesicular trafficking and release of acetylcholine. The Zn-endoprotease activity of the LC of BoNT/A is a target for the development of small molecule inhibitors of BoNT/A-mediated toxicity. A variety of BoNT/A LC inhibitors have been described to date and we focus here primarily on the Zn-binding 8-hydroxyquinoline structural type as well as some of the previously-described hydroxamic acids.

Crystal structure of a eukaryotic zinc-dependent histone deacetylase, human HDAC8, complexed with a hydroxamic acid inhibitor.

PubMed

Vannini, Alessandro; Volpari, Cinzia; Filocamo, Gessica; Casavola, Elena Caroli; Brunetti, Mirko; Renzoni, Debora; Chakravarty, Prasun; Paolini, Chantal; De Francesco, Raffaele; Gallinari, Paola; Steinkühler, Christian; Di Marco, Stefania

2004-10-19

Histone deacetylases (HDACs) are a family of enzymes involved in the regulation of gene expression, DNA repair, and stress response. These processes often are altered in tumors, and HDAC inhibitors have had pronounced antitumor activity with promising results in clinical trials. Here, we report the crystal structure of human HDAC8 in complex with a hydroxamic acid inhibitor. Such a structure of a eukaryotic zinc-dependent HDAC has not be described previously. Similar to bacterial HDAC-like protein, HDAC8 folds in a single alpha/beta domain. The inhibitor and the zinc-binding sites are similar in both proteins. However, significant differences are observed in the length and structure of the loops surrounding the active site, including the presence of two potassium ions in HDAC8 structure, one of which interacts with key catalytic residues. CD data suggest a direct role of potassium in the fold stabilization of HDAC8. Knockdown of HDAC8 by RNA interference inhibits growth of human lung, colon, and cervical cancer cell lines, highlighting the importance of this HDAC subtype for tumor cell proliferation. Our findings open the way for the design and development of selective inhibitors of HDAC8 as possible antitumor agents.

Trichostatin A increases SMN expression and survival in a mouse model of spinal muscular atrophy

PubMed Central

Avila, Amy M.; Burnett, Barrington G.; Taye, Addis A.; Gabanella, Francesca; Knight, Melanie A.; Hartenstein, Parvana; Cizman, Ziga; Di Prospero, Nicholas A.; Pellizzoni, Livio; Fischbeck, Kenneth H.; Sumner, Charlotte J.

2007-01-01

The inherited motor neuron disease spinal muscular atrophy (SMA) is caused by mutation of the telomeric survival motor neuron 1 (SMN1) gene with retention of the centromeric SMN2 gene. We sought to establish whether the potent and specific hydroxamic acid class of histone deacetylase (HDAC) inhibitors activates SMN2 gene expression in vivo and modulates the SMA disease phenotype when delivered after disease onset. Single intraperitoneal doses of 10 mg/kg trichostatin A (TSA) in nontransgenic and SMA model mice resulted in increased levels of acetylated H3 and H4 histones and modest increases in SMN gene expression. Repeated daily doses of TSA caused increases in both SMN2-derived transcript and SMN protein levels in neural tissues and muscle, which were associated with an improvement in small nuclear ribonucleoprotein (snRNP) assembly. When TSA was delivered daily beginning on P5, after the onset of weight loss and motor deficit, there was improved survival, attenuated weight loss, and enhanced motor behavior. Pathological analysis showed increased myofiber size and number and increased anterior horn cell size. These results indicate that the hydroxamic acid class of HDAC inhibitors activates SMN2 gene expression in vivo and has an ameliorating effect on the SMA disease phenotype when administered after disease onset. PMID:17318264

Tandem mass spectrometry of coprogen and deferoxamine hydroxamic siderophores.

PubMed

Simionato, Ana V C; de Souza, Gezimar D; Rodrigues-Filho, Edson; Glick, James; Vouros, Paul; Carrilho, Emanuel

2006-01-01

Mechanisms of fragmentation of hydroxamic siderophores are proposed comparing deuterated and nondeuterated samples. Standard siderophores (e.g. deferoxamine and coprogen) were directly injected into both ion trap and linear quadrupole mass spectrometers with electrospray ionization (ESI). Four and two fragmentation steps were carried out for deferoxamine and coprogen (analyzed by positive and negative ESI, respectively). Deferoxamine cleavages occurred in both peptide and hydroxamic bonds while the coprogen fragmentation pattern is more elaborate, since it contains Fe(III) in its structure.

Histone Deacetylase (HDAC) Inhibitors: Current Evidence for Therapeutic Activities in Pancreatic Cancer.

PubMed

Damaskos, Christos; Garmpis, Nikolaos; Karatzas, Theodore; Nikolidakis, Lampros; Kostakis, Ioannis D; Garmpi, Anna; Karamaroudis, Stefanos; Boutsikos, Georgios; Damaskou, Zoi; Kostakis, Alkiviadis; Kouraklis, Gregory

2015-06-01

Pancreatic carcinoma is one of the leading causes of cancer death. Current standard treatments include surgical resection, chemotherapy and radiotherapy but patient's prognosis remains poor and present severe side-effects. Contemporary oncology found a wide variety of novel anticancer drugs that regulate the epigenetic mechanisms of tumor genesis. Histone deacetylases (HDACs) are enzymes with pleiotropic activities that control critical functions of the cell through regulation of the acetylation states of histone proteins and other non-histone protein targets. They are divided into four groups, each with different localization in the cell, role and structure. Histone deacetylase inhibitors (HDACIs) are substances, which inhibit the function of HDACs. We recognize four leading groups (hydroxamic acid, cyclic tetrapeptide, benzamide, aliphatic acid). There are many HDACIs currently in pre-clinical and two (vorinostat, romidepsin) in clinical stages of investigation for pancreatic cancer. Numerous studies argue for the use HDACIs as monotherapy, others suggest that combination of HDACIs with other antitumor drugs has better therapeutic results. This review focuses on the use of HDACIs as novel anticancer drugs and will explain the mechanisms of therapeutic effect on pancreatic cancer. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Design, synthesis and anticancer activity of piperazine hydroxamates and their histone deacetylase (HDAC) inhibitory activity.

PubMed

Chetan, Bhadaliya; Bunha, Mahesh; Jagrat, Monika; Sinha, Barij Nayan; Saiko, Philipp; Graser, Geraldine; Szekeres, Thomas; Raman, Ganapathy; Rajendran, Praveen; Moorthy, Dhatchana; Basu, Arijit; Jayaprakash, Venkatesan

2010-07-01

Six compounds were synthesized with piperazine in linker region and hydroxamate as Zinc Binding Group (ZBG). They were screened against three cancer cell-lines (NCIH460; HCT116; U251). Compounds 5c and 5f with GI(50) value of 9.33+/-1.3 microM and 12.03+/-4 microM, respectively, were tested for their inhibitory potential on hHDAC8. Compound 5c had IC(50) of 33.67 microM. Compounds were also screened for their anticancer activity against HL60 human promyelocytic leukemia cell line due to the presence of pharmacophoric features of RR inhibitors in them. Compound 5c had IC(50) of 0.6 microM at 48h. 2010 Elsevier Ltd. All rights reserved.

Structure-activity relationships of hydroxamate-based histone deacetylase-8 inhibitors: reality behind anticancer drug discovery.

PubMed

Amin, Sk Abdul; Adhikari, Nilanjan; Jha, Tarun

2017-12-01

The pan-histone deacetylase (HDAC) inhibitors comprise a fish-like structural orientation where hydrophobic aryl- and zinc-binding groups act as head and tail, respectively of a fish. The linker moiety correlates the body of the fish linking head and tail groups. Despite these pan-HDAC inhibitors, selective HDAC-8 inhibitors are still in demand as a safe remedy. HDAC-8 is involved in invasion and metastasis in cancer. This review deals with the rationale behind HDAC-8 inhibitory activity and selectivity along with detailed structure-activity relationships of diverse hydroxamate-based HDAC-8 inhibitors. HDAC-8 inhibitory potency may be increased by modifying the fish-like pharmacophoric features of such type of pan-HDAC inhibitors. This review may provide a preliminary basis to design and optimize new lead molecules with higher HDAC-8 inhibitory activity. This work may surely enlighten in providing useful information in the field of target-specific anticancer therapy.

FhuD1, a Ferric Hydroxamate-binding Lipoprotein in Staphylococcus aureus - A case of gene duplication and lateral transfer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sebulsky, M. Tom; Speziali, Craig D.; Shilton, Brian H.

Staphylococcus aureus can utilize ferric hydroxamates as a source of iron under iron-restricted growth conditions. Proteins involved in this transport process are: FhuCBG, which encodes a traffic ATPase; FhuD2, a post-translationally modified lipoprotein that acts as a high affinity receptor at the cytoplasmic membrane for the efficient capture of ferric hydroxamates; and FhuD1, a protein with similarity to FhuD2. Gene duplication likely gave rise to fhuD1 and fhuD2. While the genomic locations of fhuCBG and fhuD2 in S. aureus strains are conserved, both the presence and the location of fhuD1 are variable. The apparent redundancy of FhuD1 led us tomore » examine the role of this protein. We demonstrate that FhuD1 is expressed only under conditions of iron limitation through the regulatory activity of Fur. FhuD1 fractions with the cell membrane and binds hydroxamate siderophores but with lower affinity than FhuD2. Using small angle x-ray scattering, the solution structure of FhuD1 resembles that of FhuD2, and only a small conformational change is associated with ferrichrome binding. FhuD1, therefore, appears to be a receptor for ferric hydroxamates, like FhuD2. Our data to date suggest, however, that FhuD1 is redundant to FhuD2 and plays a minor role in hydroxamate transport. However, given the very real possibility that we have not yet identified the proper conditions where FhuD1 does provide an advantage over FhuD2, we anticipate that FhuD1 serves an enhanced role in the transport of untested hydroxamate siderophores and that it may play a prominent role during the growth of S. aureus in its natural environments.« less

A Rational Approach for the Identification of Non-Hydroxamate HDAC6-Selective Inhibitors

NASA Astrophysics Data System (ADS)

Goracci, Laura; Deschamps, Nathalie; Randazzo, Giuseppe Marco; Petit, Charlotte; Dos Santos Passos, Carolina; Carrupt, Pierre-Alain; Simões-Pires, Claudia; Nurisso, Alessandra

2016-07-01

The human histone deacetylase isoform 6 (HDAC6) has been demonstrated to play a major role in cell motility and aggresome formation, being interesting for the treatment of multiple tumour types and neurodegenerative conditions. Currently, most HDAC inhibitors in preclinical or clinical evaluations are non-selective inhibitors, characterised by a hydroxamate zinc-binding group (ZBG) showing off-target effects and mutagenicity. The identification of selective HDAC6 inhibitors with novel chemical properties has not been successful yet, also because of the absence of crystallographic information that makes the rational design of HDAC6 selective inhibitors difficult. Using HDAC inhibitory data retrieved from the ChEMBL database and ligand-based computational strategies, we identified 8 original new non-hydroxamate HDAC6 inhibitors from the SPECS database, with activity in the low μM range. The most potent and selective compound, bearing a hydrazide ZBG, was shown to increase tubulin acetylation in human cells. No effects on histone H4 acetylation were observed. To the best of our knowledge, this is the first report of an HDAC6 selective inhibitor bearing a hydrazide ZBG. Its capability to passively cross the blood-brain barrier (BBB), as observed through PAMPA assays, and its low cytotoxicity in vitro, suggested its potential for drug development.

Promotion of Germination Using Hydroxamic Acid Inhibitors of 9-cis-Epoxycarotenoid Dioxygenase

PubMed Central

Awan, Sajjad Z.; Chandler, Jake O.; Harrison, Peter J.; Sergeant, Martin J.; Bugg, Timothy D. H.; Thompson, Andrew J.

2017-01-01

Abscisic acid (ABA) inhibits seed germination and the regulation of ABA biosynthesis has a role in maintenance of seed dormancy. The key rate-limiting step in ABA biosynthesis is catalyzed by 9-cis-epoxycarotenoid dioxygenase (NCED). Two hydroxamic acid inhibitors of carotenoid cleavage dioxygenase (CCD), D4 and D7, previously found to inhibit CCD and NCED in vitro, are shown to have the novel property of decreasing mean germination time of tomato (Solanum lycopersicum L.) seeds constitutively overexpressing LeNCED1. Post-germination, D4 exhibited no negative effects on tomato seedling growth in terms of height, dry weight, and fresh weight. Tobacco (Nicotiana tabacum L.) seeds containing a tetracycline-inducible LeNCED1 transgene were used to show that germination could be negatively and positively controlled through the chemical induction of gene expression and the chemical inhibition of the NCED protein: application of tetracycline increased mean germination time and delayed hypocotyl emergence in a similar manner to that observed when exogenous ABA was applied and this was reversed by D4 when NCED expression was induced at intermediate levels. D4 also improved germination in lettuce (Lactuca sativa L.) seeds under thermoinhibitory temperatures and in tomato seeds imbibed in high osmolarity solutions of polyethylene glycol. D4 reduced ABA and dihydrophaseic acid accumulation in tomato seeds overexpressing LeNCED1 and reduced ABA accumulation in wild type tomato seeds imbibed on polyethylene glycol. The evidence supports a mode of action of D4 through NCED inhibition, and this molecule provides a lead compound for the design of NCED inhibitors with greater specificity and potency. PMID:28373878

Substrate-Directed Catalytic Selective Chemical Reactions.

PubMed

Sawano, Takahiro; Yamamoto, Hisashi

2018-05-04

The development of highly efficient reactions at only the desired position is one of the most important subjects in organic chemistry. Most of the reactions in current organic chemistry are reagent- or catalyst-controlled reactions, and the regio- and stereoselectivity of the reactions are determined by the inherent nature of the reagent or catalyst. In sharp contrast, substrate-directed reaction determines the selectivity of the reactions by the functional group on the substrate and can strictly distinguish sterically and electronically similar multiple reaction sites in the substrate. In this Perspective, three topics of substrate-directed reaction are mainly reviewed: (1) directing group-assisted epoxidation of alkenes, (2) ring-opening reactions of epoxides by various nucleophiles, and (3) catalytic peptide synthesis. Our newly developed synthetic methods with new ligands including hydroxamic acid derived ligands realized not only highly efficient reactions but also pinpointed reactions at the expected position, demonstrating the substrate-directed reaction as a powerful method to achieve the desired regio- and stereoselective functionalization of molecules from different viewpoints of reagent- or catalyst-controlled reactions.

Investigation of non-hydroxamate scaffolds against HDAC6 inhibition: A pharmacophore modeling, molecular docking, and molecular dynamics simulation approach.

PubMed

Zeb, Amir; Park, Chanin; Son, Minky; Rampogu, Shailima; Alam, Syed Ibrar; Park, Seok Ju; Lee, Keun Woo

2018-06-01

Proteins deacetylation by Histone deacetylase 6 (HDAC6) has been shown in various human chronic diseases like neurodegenerative diseases and cancer, and hence is an important therapeutic target. Since, the existing inhibitors have hydroxamate group, and are not HDAC6-selective, therefore, this study has designed to investigate non-hydroxamate HDAC6 inhibitors. Ligand-based pharmacophore was generated from 26 training set compounds of HDAC6 inhibitors. The statistical parameters of pharmacophore (Hypo1) included lowest total cost of 115.63, highest cost difference of 135.00, lowest RMSD of 0.70 and the highest correlation of 0.98. The pharmacophore was validated by Fischer's Randomization and Test Set validation, and used as screening tool for chemical databases. The screened compounds were filtered by fit value ([Formula: see text]), estimated Inhibitory Concentration (IC[Formula: see text]) ([Formula: see text]), Lipinski's Rule of Five and Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) Descriptors to identify drug-like compounds. Furthermore, the drug-like compounds were docked into the active site of HDAC6. The best docked compounds were selected having goldfitness score [Formula: see text] and [Formula: see text], and hydrogen bond interaction with catalytic active residues. Finally, three inhibitors having sulfamoyl group were selected by Molecular Dynamic (MD) simulation, which showed stable root mean square deviation (RMSD) (1.6-1.9[Formula: see text]Å), lowest potential energy ([Formula: see text][Formula: see text]kJ/mol), and hydrogen bonding with catalytic active residues of HDAC6.

Production and Characterization of Desmalonichrome Relative Binding Affinity for Uranyl Ions in Relation to Other Siderophores

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mo, Kai-For; Dai, Ziyu; Wunschel, David S.

2016-06-24

Siderophores are Fe binding secondary metabolites that have been investigated for their uranium binding properties. Much of the previous work has focused on characterizing hydroxamate types of siderophores, such as desferrioxamine B, for their uranyl binding affinity. Carboxylate forms of these metabolites hold potential to be more efficient chelators of uranyl, yet they have not been widely studied and are more difficult to obtain. Desmalonichrome is a carboxylate siderophore which is not commercially available and so was obtained from the ascomycete fungus Fusarium oxysporum cultivated under Fe depleted conditions. The relative affinity for uranyl binding of desmalonichrome was investigated usingmore » a competitive analysis of binding affinities between uranyl acetate and different concentrations of iron(III) chloride using electrospray ionization mass spectrometry (ESI-MS). In addition to desmalonichrome, three other siderophores, including two hydroxamates (desferrioxamine B and desferrichrome) and one carboxylate (desferrichrome A) were studied to understand their relative affinities for the uranyl ion at two pH values. The binding affinities of hydroxymate siderophores to uranyl ion were found to decrease to a greater degree at lower pH as the concentration of Fe (III) ion increases. On the other hand, lowering pH has little impact on the binding affinities between carboxylate siderophores and uranyl ion. Desmalonichrome was shown to have the greatest relative affinity for uranyl at any pH and Fe(III) concentration. These results suggest that acidic functional groups in the ligands are critical for strong chelation with uranium at lower pH.« less

Regioselective copper-catalyzed alkylation of [2.2.2]-acylnitroso cycloadducts: remarkable effect of the halide of Grignard reagents.

PubMed

Crotti, Stefano; Bertolini, Ferruccio; di Bussolo, Valeria; Pineschi, Mauro

2010-04-16

Ring opening with organometallic reagents of [2.2.2]-acylnitroso cycloadducts, including an enantioselective kinetic resolution of these compounds, has been accomplished for the first time. By the careful choice of reaction conditions, it was possible to obtain new cyclohexenyl hydroxamic acids with complete anti-stereoselectivity and a nice regioalternating control. A remarkable effect of the halogen of the Grignard reagent was observed during ring opening.

Anti-tumor effects of suberoylanilide hydroxamic acid on Epstein–Barr virus-associated T cell and natural killer cell lymphoma

PubMed Central

Siddiquey, Mohammed NA; Nakagawa, Hikaru; Iwata, Seiko; Kanazawa, Tetsuhiro; Suzuki, Michio; Imadome, Ken-Ichi; Fujiwara, Shigeyoshi; Goshima, Fumi; Murata, Takayuki; Kimura, Hiroshi

2014-01-01

The ubiquitous Epstein–Barr virus (EBV) infects not only B cells but also T cells and natural killer (NK) cells and is associated with various lymphoid malignancies. Recent studies have reported that histone deacetylase (HDAC) inhibitors exert anticancer effects against various tumor cells. In the present study, we have evaluated both the in vitro and in vivo effects of suberoylanilide hydroxamic acid (SAHA), an HDAC inhibitor, on EBV-positive and EBV-negative T and NK lymphoma cells. Several EBV-positive and EBV-negative T and NK cell lines were treated with various concentrations of SAHA. SAHA suppressed the proliferation of T and NK cell lines, although no significant difference was observed between EBV-positive and EBV-negative cell lines. SAHA induced apoptosis and/or cell cycle arrest in several T and NK cell lines. In addition, SAHA increased the expression of EBV-lytic genes and decreased the expression of EBV-latent genes. Next, EBV-positive NK cell lymphoma cells were subcutaneously inoculated into severely immunodeficient NOD/Shi-scid/IL-2Rγnull mice, and then SAHA was administered intraperitoneally. SAHA inhibited tumor progression and metastasis in the murine xenograft model. SAHA displayed a marked suppressive effect against EBV-associated T and NK cell lymphomas through either induction of apoptosis or cell cycle arrest, and may represent an alternative treatment option. PMID:24712440

A quantum chemical study of molecular properties and QSPR modeling of oximes, amidoximes and hydroxamic acids with nucleophilic activity against toxic organophosphorus agents

NASA Astrophysics Data System (ADS)

Alencar Filho, Edilson B.; Santos, Aline A.; Oliveira, Boaz G.

2017-04-01

The proposal of this work includes the use of quantum chemical methods and cheminformatics strategies in order to understand the structural profile and reactivity of α-nucleophiles compounds such as oximes, amidoximes and hydroxamic acids, related to hydrolysis rate of organophosphates. Theoretical conformational study of 41 compounds were carried out through the PM3 semiempirical Hamiltonian, followed by the geometry optimization at the B3LYP/6-31+G(d,p) level of theory, complemented by Polarized Continuum Model (PCM) to simulate the aqueous environment. In line with the experimental hypothesis about hydrolytic power, the strength of the Intramolecular Hydrogen Bonds (IHBs) at light of the Bader's Quantum Theory of Atoms in Molecules (QTAIM) is related to the preferential conformations of α-nucleophiles. A set of E-Dragon descriptors (1,666) were submitted to a variable selection through Ordered Predictor Selection (OPS) algorithm. Five descriptors, including atomic charges obtained from the Natural Bond Orbitals (NBO) protocol jointly with a fragment index associated to the presence/absence of IHBs, provided a Quantitative Structure-Property Relationship (QSPR) model via Multiple Linear Regression (MLR). This model showed good validation parameters (R2 = 0.80, Qloo2 = 0.67 and Qext2 = 0.81) and allowed the identification of significant physicochemical features on the molecular scaffold in order to design compounds potentially more active against organophosphorus poisoning.

Efficacy and Safety Comparison Between Suberoylanilide Hydroxamic Acid and Mitomycin C in Reducing the Risk of Corneal Haze After PRK Treatment In Vivo.

PubMed

Anumanthan, Govindaraj; Sharma, Ajay; Waggoner, Michael; Hamm, Chuck W; Gupta, Suneel; Hesemann, Nathan P; Mohan, Rajiv R

2017-12-01

This study compared the efficacy and safety of suberoylanilide hydroxamic acid (SAHA) and mitomycin C (MMC) up to 4 months in the prevention of corneal haze induced by photorefractive keratectomy (PRK) in rabbits in vivo. Corneal haze in rabbits was produced with -9.00 diopter PRK. A single application of SAHA (25 μM) or MMC (0.02%) was applied topically immediately after PRK. Effects of the two drugs were analyzed by slit-lamp microscope, specular microscope, TUNEL assay, and immunofluorescence. Single topical adjunct use of SAHA (25 μM) or MMC (0.02%) after PRK attenuated more than 95% corneal haze and myofibroblast formation (P < .001). SAHA did not reduce keratocyte density, cause keratocyte apoptosis, or increase immune cell infiltration compared to MMC (P < .01 or .001). Furthermore, SAHA dosing did not compromise corneal endothelial phenotype, density, or function in rabbit eyes, whereas MMC application did (P < .01 or .001). SAHA and MMC significantly decreased corneal haze after PRK in rabbits in vivo. SAHA exhibited significantly reduced short- and long-term damage to the corneal endothelium compared to MMC in rabbits. SAHA is an effective and potentially safer alternative to MMC for the prevention of corneal haze after PRK. Clinical trials are warranted. [J Refract Surg. 2017;33(12):834-839.]. Copyright 2017, SLACK Incorporated.

The epigenetic agents suberoylanilide hydroxamic acid and 5‑AZA‑2' deoxycytidine decrease cell proliferation, induce cell death and delay the growth of MiaPaCa2 pancreatic cancer cells in vivo.

PubMed

Susanto, Johana M; Colvin, Emily K; Pinese, Mark; Chang, David K; Pajic, Marina; Mawson, Amanda; Caldon, C Elizabeth; Musgrove, Elizabeth A; Henshall, Susan M; Sutherland, Robert L; Biankin, Andrew V; Scarlett, Christopher J

2015-05-01

Despite incremental advances in the diagnosis and treatment for pancreatic cancer (PC), the 5‑year survival rate remains <5%. Novel therapies to increase survival and quality of life for PC patients are desperately needed. Epigenetic thera-peutic agents such as histone deacetylase inhibitors (HDACi) and DNA methyltransferase inhibitors (DNMTi) have demonstrated therapeutic benefits in human cancer. We assessed the efficacy of these epigenetic therapeutic agents as potential therapies for PC using in vitro and in vivo models. Treatment with HDACi [suberoylanilide hydroxamic acid (SAHA)] and DNMTi [5‑AZA‑2' deoxycytidine (5‑AZA‑dc)] decreased cell proliferation in MiaPaCa2 cells, and SAHA treatment, with or without 5‑AZA‑dc, resulted in higher cell death and lower DNA synthesis compared to 5‑AZA‑dc alone and controls (DMSO). Further, combination treatment with SAHA and 5‑AZA‑dc significantly increased expression of p21WAF1, leading to G1 arrest. Treatment with epigenetic agents delayed tumour growth in vivo, but did not decrease growth of established pancreatic tumours. In conclusion, these data demonstrate a potential role for epigenetic modifier drugs for the management of PC, specifically in the chemoprevention of PC, in combination with other chemotherapeutic agents.

Ionic liquid containing hydroxamate and N-alkyl sulfamate ions

DOEpatents

Friesen, Cody A.; Wolfe, Derek; Johnson, Paul Bryan

2016-03-15

Embodiments of the invention are related to ionic liquids and more specifically to ionic liquids used in electrochemical metal-air cells in which the ionic liquid includes a cation and an anion selected from hydroxamate and/or N-alkyl sulfamate anions.

Stereoselective HDAC inhibition from cysteine-derived zinc-binding groups.

PubMed

Butler, Kyle V; He, Rong; McLaughlin, Kathryn; Vistoli, Giulio; Langley, Brett; Kozikowski, Alan P

2009-08-01

A series of small-molecule histone deacetylase (HDAC) inhibitors, which feature zinc binding groups derived from cysteine, were synthesized. These inhibitors were tested against multiple HDAC isoforms, and the most potent, compound 10, was determined to have IC(50) values below 1 microM. The compounds were also tested in a cellular assay of oxidative stress-induced neurodegeneration. Many of the inhibitors gave near-complete protection against cell death at 10 microM without the neurotoxicity seen with hydroxamic acid-based inhibitors, and were far more neuroprotective than HDAC inhibitors currently in clinical trials. Both enantiomers of cysteine were used in the synthesis of a variety of novel zinc-binding groups (ZBGs). Derivatives of L-cysteine were active in the HDAC inhibition assays, while the derivatives of D-cysteine were inactive. Notably, the finding that both the D- and L-cysteine derivatives were active in the neuroprotection assays suggests that multiple mechanisms are working to protect the neurons from cell death. Molecular modeling was employed to investigate the differences in inhibitory activity between the HDAC inhibitors generated from the two enantiomeric forms of cysteine.

A structure-based virtual screening approach toward the discovery of histone deacetylase inhibitors: identification of promising zinc-chelating groups.

PubMed

Park, Hwangseo; Kim, Sukyoung; Kim, Yong Eun; Lim, Soo-Jeong

2010-04-06

The inhibitors of histone deacetylases (HDACs) have drawn a great deal of attention due to their promising potential as small-molecule therapeutics for the treatment of cancer. By means of virtual screening with docking simulations under consideration of the effects of ligand solvation, we were able to identify six novel HDAC inhibitors with IC(50) values ranging from 1 to 100 muM. These newly identified inhibitors are structurally diverse and have various chelating groups for the active site zinc ion, including N-[1,3,4]thiadiazol-2-yl sulfonamide, N-thiazol-2-yl sulfonamide, and hydroxamic acid moieties. The former two groups are included in many drugs in current clinical use and have not yet been reported as HDAC inhibitors. Therefore, they can be considered as new inhibitor scaffolds for the development of anticancer drugs by structure-activity relationship studies to improve the inhibitory activities against HDACs. Interactions with the HDAC1 active site residues responsible for stabilizing these new inhibitors are addressed in detail.

Differential protein acetylation induced by novel histone deacetylase inhibitors.

PubMed

Glaser, K B; Li, J; Pease, L J; Staver, M J; Marcotte, P A; Guo, J; Frey, R R; Garland, R B; Heyman, H R; Wada, C K; Vasudevan, A; Michaelides, M R; Davidsen, S K; Curtin, M L

2004-12-17

Histone deacetylase (HDAC) inhibitors induce the hyperacetylation of nucleosomal histones in carcinoma cells resulting in the expression of repressed genes that cause growth arrest, terminal differentiation, and/or apoptosis. In vitro selectivity of several novel hydroxamate HDAC inhibitors including succinimide macrocyclic hydroxamates and the non-hydroxamate alpha-ketoamide inhibitors was investigated using isolated enzyme preparations and cellular assays. In vitro selectivity for the HDAC isozymes (HDAC1/2, 3, 4/3, and 6) was not observed for these HDAC inhibitors or the reference HDAC inhibitors, MS-275 and SAHA. In T24 and HCT116 cells these compounds caused the accumulation of acetylated histones H3 and H4; however, the succinimide macrocyclic hydroxamates and the alpha-ketoamides did not cause the accumulation of acetylated alpha-tubulin. These data suggest "selectivity" can be observed at the cellular level with HDAC inhibitors and that the nature of the zinc-chelating moiety is an important determinant of activity against tubulin deacetylase.

4-(1-Ethyl-4-anisyl-imidazol-5-yl)-N-hydroxycinnamide - A new pleiotropic HDAC inhibitor targeting cancer cell signalling and cytoskeletal organisation.

PubMed

Mahal, Katharina; Kahlen, Philip; Biersack, Bernhard; Schobert, Rainer

2015-08-15

Histone deacetylases (HDAC) which play a crucial role in cancer cell proliferation are promising drug targets. However, HDAC inhibitors (HDACi) modelled on natural hydroxamic acids such as trichostatin A frequently lead to resistance or even an increased agressiveness of tumours. As a workaround we developed 4-(1-ethyl-4-anisyl-imidazol-5-yl)-N-hydroxycinnamide (etacrox), a hydroxamic acid that combines HDAC inhibition with synergistic effects of the 4,5-diarylimidazole residue. Etacrox proved highly cytotoxic against a panel of metastatic and resistant cancer cell lines while showing greater specificity for cancer over non-malignant cells when compared to the approved HDACi vorinostat. Like the latter, etacrox and the closely related imidazoles bimacroxam and animacroxam acted as pan-HDACi yet showed some specificity for HDAC6. Akt signalling and interference with nuclear beta-catenin localisation were elicited by etacrox at lower concentrations when compared to vorinostat. Moreover, etacrox disrupted the microtubule and focal adhesion dynamics of cancer cells and inhibited the proteolytic activity of prometastatic and proangiogenic matrix metalloproteinases. As a consequence, etacrox acted strongly antimigratory and antiinvasive against various cancer cell lines in three-dimensional transwell invasion assays and also antiangiogenic in vivo with respect to blood vessel formation in the chorioallantoic membrane assay. These pleiotropic effects and its water-solubility and tolerance by mice render etacrox a promising new HDACi candidate. Copyright © 2015 Elsevier Inc. All rights reserved.

N-(2-hydroxyphenyl)-2-propylpentanamide, a valproic acid aryl derivative designed in silico with improved anti-proliferative activity in HeLa, rhabdomyosarcoma and breast cancer cells.

PubMed

Prestegui-Martel, Berenice; Bermúdez-Lugo, Jorge Antonio; Chávez-Blanco, Alma; Dueñas-González, Alfonso; García-Sánchez, José Rubén; Pérez-González, Oscar Alberto; Padilla-Martínez, Itzia Irene; Fragoso-Vázquez, Manuel Jonathan; Mendieta-Wejebe, Jessica Elena; Correa-Basurto, Ana María; Méndez-Luna, David; Trujillo-Ferrara, José; Correa-Basurto, José

2016-01-01

Epigenetic alterations are associated with cancer and their targeting is a promising approach for treatment of this disease. Among current epigenetic drugs, histone deacetylase (HDAC) inhibitors induce changes in gene expression that can lead to cell death in tumors. Valproic acid (VPA) is a HDAC inhibitor that has antitumor activity at mM range. However, it is known that VPA is a hepatotoxic drug. Therefore, the aim of this study was to design a set of VPA derivatives adding the arylamine core of the suberoylanilide hydroxamic acid (SAHA) with different substituents at its carboxyl group. These derivatives were submitted to docking simulations to select the most promising compound. The compound 2 (N-(2-hydroxyphenyl)-2-propylpentanamide) was the best candidate to be synthesized and evaluated in vitro as an anti-cancer agent against HeLa, rhabdomyosarcoma and breast cancer cell lines. Compound 2 showed a better IC 50 (μM range) than VPA (mM range) on these cancer cells. And also, 2 was particularly effective on triple negative breast cancer cells. In conclusion, 2 is an example of drugs designed in silico that show biological properties against human cancer difficult to treat as triple negative breast cancer.

Synthesis of hexavalent molybdenum formo- and aceto-hydroxamates and deferoxamine via liquid-liquid metal partitioning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Breshears, Andrew T.; Brown, M. Alex; Bloom, Ira

We report a new method of crystal growth and synthesis based on liquid-liquid partitioning that allows for isolation and in-depth characterization of molybdenyl bis(formohydroxamate), Mo-FHA, molybdenyl bis(acetohydroxamate), Mo-AHA, and molybdenyl deferoxamine, Mo-DFO, for the first time. This novel approach affords shorter crystal growth time (hourly timeframe) without sacrificing crystal size or integrity when other methods of crystallization were unsuccessful. All three Mo complexes are characterized in solution via FTIR, NMR, UV-vis, and EXAFS spectroscopy. Mo-AHA and Mo-FHA structures are resolved by single crystal X-ray diffraction. Using the molybdenyl hydroxamate structural information, the speciation of Mo in a siderophore complex (Mo-DFO)more » is determined via complimentary spectroscopic methods and confirmed by DFT calculations. ESI-MS verifies that a complex of 1:1 molybdenum to deferoxamine is present in solution. Additionally, the Mo solution speciation in the precursor organic phase, MoO2(NO3)2HEH[EHP]2 (where HEH[EHP] is 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester), is characterized by FTIR and EXAFS spectroscopy as well as DFT calculations.« less

Novel Bis-(arylsulfonamide) hydroxamate-Based Selective MMP Inhibitors

PubMed Central

Subramaniam, Rajesh; Haldar, Manas K.; Tobwala, Shakila; Ganguly, Bratati; Srivastava, D. K.; Mallik, Sanku

2008-01-01

A series of bis-(arylsulfonamide) hydroxamate inhibitors were synthesized. These compounds exhibit good potency against MMP-7 and MMP-9 depending on the nature, steric bulk and substitution pattern of the substituents in the benzene ring. In general, the preliminary structure-activity relationships (SAR) suggest that among the DAPA hydroxamates (i) electron-rich benzene rings of the sulfonamides may produce better inhibitors than electron-poor analogs. However, potential H-bond acceptors can reverse the trend depending on the isozyme; (ii) isozyme-selectivity between MMP-7 and -9 can be conferred through steric bulk and substitution pattern of the substituents in the benzene ring and (iii) the MMP-10 inhibition pattern of the compounds paralleled that for MMP-9. PMID:18442906

Acetyl transfer in arylamine metabolism

PubMed Central

Booth, J.

1966-01-01

1. N-Hydroxyacetamidoaryl compounds (hydroxamic acids) are metabolites of arylamides, and an enzyme that transfers the acetyl group from these derivatives to arylamines has been found in rat tissues. The reaction products were identified by thin-layer chromatography and a spectrophotometric method, with 4-amino-azobenzene as acetyl acceptor, was used to measure enzyme activity. 2. The acetyltransferase was in the soluble fraction of rat liver, required a thiol for maximum activity and had a pH optimum between 6·0 and 7·5. 3. The soluble fractions of various rat tissues showed decreasing activity in the following order: liver, adrenal, kidney, lung, spleen, testis, heart; brain was inactive. 4. With the exception of aniline and aniline derivatives all the arylamines tested were effective as acetyl acceptors but aromatic compounds with side-chain amino groups were inactive. 5. The N-hydroxyacetamido derivatives of 2-naphthylamine, 4-amino-biphenyl and 2-aminofluorene were active acetyl donors but N-hydroxyacetanilide showed only slight activity. Acetyl-CoA was not a donor. 6. Some properties of the enzyme are compared with those of other acetyltransferases. PMID:5969287

Oxime amides as a novel zinc binding group in histone deacetylase inhibitors: synthesis, biological activity, and computational evaluation.

PubMed

Botta, Cinzia B; Cabri, Walter; Cini, Elena; De Cesare, Lucia; Fattorusso, Caterina; Giannini, Giuseppe; Persico, Marco; Petrella, Antonello; Rondinelli, Francesca; Rodriquez, Manuela; Russo, Adele; Taddei, Maurizio

2011-04-14

Several oxime containing molecules, characterized by a SAHA-like structure, were explored to select a potentially new biasing binding element for the zinc in HDAC catalytic site. All compounds were evaluated for their in vitro inhibitory activity against the 11 human HDACs isoforms. After identification of a "hit" molecule, a programmed variation at the cap group and at the linker was carried out in order to increase HDAC inhibition and/or paralogue selectivity. Some of the new derivatives showed increased activity against a number of HDAC isoforms, even if their overall activity range is still far from the inhibition values reported for SAHA. Moreover, different from what was reported for their hydroxamic acid analogues the new α-oxime amide derivatives do not select between class I and class II HDACs; rather they target specific isoforms in each class. These somehow contradictory results were finally rationalized by a computational assisted SAR, which gave us the chance to understand how the oxime derivatives interact with the catalytic site and justify the observed activity profile.

[Modeling of linoleyl hydroxamic acid influence on lipoxygenases in vitro].

PubMed

Skaterna, T D; Kopich, V M; Tserniuk, V M; Kharchenko, O V

2009-01-01

5-Lipoxygenase (5-LO) (1.13.11.12) demonstrates its activity in membrane-associated state. A system in vitro with increasing quantity of mixed micelle of nonionic detergent Lubrol PX and substrate--linoleic acid (LA) was used for understanding of 5-LO catalytic activity mechanism, which depends on the membrane environment. Physical parameters of micelles with molar ratio LA-Lubrol PX = 0.3:1 and micelles with 5-LO inhibitor--linoleyl hydroxamic acid (LHA), LA and Lubrol PX (0.03:0.3:1) were characterized by gel-filtration method on Sephadex G-200. It was determined, that Stock's radii were 4.83-5.79 nm for micelles with total LA--50-2000 microM and average molecular mass--177 000-212 000 Da. The presence of 10 microM LHA has no influence on physical parameters of the system. Influence of LHA on kinetic parameters of LA oxidation reaction catalized by potato tubers 5-LO in characterized mixed micelle system was also studied. Substrate dependences curves of 5-LO LA oxidation steady-state rates under conditions of the mixed micelle with ratio LA-lubrol PX = 0.3:1, LHA-LA-Lubrol PX = 0.03:0.3:1 and LHA-LA-Lubrol PX = 0.12:0.3:1 were typical of the substrate inhibition. The presence of inhibitor had no effect on the number of additional substrate molecules--LA which contact with enzyme-substrate complex and decreased V(max) essentially. To predict further inhibitor transformation in the cell the influence of 13-hydroperoxy- and 13-hydroxy LHA on potato tubers 5-LO and porcine leucocyte 12-LO was investigated. It was established that LHA oxidized forms displayed as no less effective inhibitors of the analyzed enzymes; 13-hydroperoxy LHA efficiency increased by an order (IC50 was 0.7 microM) for 12-LO. The possibility of 5-LO to oxidize inhibitor LHA under 50 microM phosphatidic acid at pH 5.0 was demonstrated.

A cyclodextrin-capped histone deacetylase inhibitor.

PubMed

Amin, Jahangir; Puglisi, Antonino; Clarke, James; Milton, John; Wang, Minghua; Paranal, Ronald M; Bradner, James E; Spencer, John

2013-06-01

We have synthesized a β-cyclodextrin (βCD)-capped histone deacetylase (HDAC) inhibitor 3 containing an alkyl linker and a zinc-binding hydroxamic acid motif. Biological evaluation (HDAC inhibition studies) of 3 enabled us to establish the effect of replacing an aryl cap (in SAHA (vorinostat,)) 1 by a large saccharidic scaffold "cap". HDAC inhibition was observed for 3, to a lesser extent than SAHA, and rationalized by molecular docking into the active site of HDAC8. However, compound 3 displayed no cellular activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

Synthesis and biological evaluation of Santacruzamate-A based analogues.

PubMed

Randino, Rosario; Gazzerro, Patrizia; Mazitschek, Ralph; Rodriquez, Manuela

2017-12-15

Several derivatives of Santacruzamate-A, a natural product that is structurally related to SAHA, were synthesized to explore the potential of carbamates and oxalylamides as novel biasing element for targeting the catalytic site of zinc-dependent histone deacetylases (HDACs). An additional class of Santacruzamate-A derivatives was synthesized to investigate the influence of the cap group and the linker element on HDAC inhibitory activity. All compounds were evaluated in dose response for their in vitro cytotoxic activity in MTT assay in HCT116 cells. HDAC inhibitory activity was evaluated in vitro by western blot analysis for histone hyperacetylation assay and biochemically for representative human HDACs isoforms. Two novel compounds were identified to exhibit potent time dependent anti proliferative activity. However, unlike hydroxamic acid analogues, the tested Santacruzamate-A derivatives showed no noticeable HDAC inhibitory activity. The ethylcarbamate moiety as unusual zinc-binding group displayed no ability to coordinate the zinc ion and thus, presumably, was not able to reproduce known inhibitor-substrate zinc-binding group interactions with the HDAC catalytic site. This study confirmed that the accommodation of the zinc-binding group is deeply critical of the positioning of the linker and the projection of the cap group toward the different surface pockets of the enzyme. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cardiomyogenic Differentiation of Human Dental Follicle-derived Stem Cells by Suberoylanilide Hydroxamic Acid and Their In Vivo Homing Property.

PubMed

Sung, Iel-Yong; Son, Han-Na; Ullah, Imran; Bharti, Dinesh; Park, Ju-Mi; Cho, Yeong-Cheol; Byun, June-Ho; Kang, Young-Hoon; Sung, Su-Jin; Kim, Jong-Woo; Rho, Gyu-Jin; Park, Bong-Wook

2016-01-01

The purpose of the present study was to investigate the in vitro cardiomyogenic differentiation potential of human dental follicle-derived stem cells (DFCs) under the influence of suberoylanilide hydroxamic acid (SAHA), a member of the histone deacetylase inhibitor family, and analyze the in vivo homing capacity of induced cardiomyocytes (iCMs) when transplanted systemically. DFCs from extracted wisdom teeth showed mesenchymal stem cell (MSC) characteristics such as plate adherent growing, expression of MSC markers (CD44, CD90, and CD105), and mesenchymal lineage-specific differentiation potential. Adding SAHA to the culture medium induced the successful in vitro differentiation of DFCs into cardiomyocytes. These iCMs expressed cardiomyogenic markers, including alpha-smooth muscle actin (α-SMA), cardiac muscle troponin T (TNNT2), Desmin, and cardiac muscle alpha actin (ACTC1) , at both the mRNA and protein level. For the assessment of homing capacity, PKH26 labeled iCMs were intraperitoneally injected (1×10 6 cells in 100 µL of PBS) into the experimental mice, and the ratios of PKH26 positive cells to the total number of injected cells, in multiple organs were determined. The calculated homing ratios, 14 days after systemic cell transplantation, were 5.6 ± 1.0%, 3.6 ± 1.1%, and 11.6 ± 2.7% in heart, liver, and kidney respectively. There was no difference in the serum levels of interleukin-2 and interleukin-10 at 14 days after transplantation, between the experimental (iCM injected) and control (no injection or PBS injection) groups. These results demonstrate that DFCs can be an excellent source for cardiomyocyte differentiation and regeneration. Moreover, the iCMs can be delivered into heart muscle via systemic administration without eliciting inflammatory or immune response. This can serve as the pilot study for further investigations into the in vitro cardiomyogenic differentiation potential of DFCs under the influence of SAHA and the in vivo homing capacity of the iCMs into the heart muscle, when injected systemically.

Non-coding nucleotides and amino acids near the active site regulate peptide deformylase expression and inhibitor susceptibility in Chlamydia trachomatis

PubMed Central

Bao, Xiaofeng; Pachikara, Niseema D.; Oey, Christopher B.; Balakrishnan, Amit; Westblade, Lars F.; Tan, Ming; Chase, Theodore; Nickels, Bryce E.

2011-01-01

Chlamydia trachomatis, an obligate intracellular bacterium, is a highly prevalent human pathogen. Hydroxamic-acid-based matrix metalloprotease inhibitors can effectively inhibit the pathogen both in vitro and in vivo, and have exhibited therapeutic potential. Here, we provide genome sequencing data indicating that peptide deformylase (PDF) is the sole target of the inhibitors in this organism. We further report molecular mechanisms that control chlamydial PDF (cPDF) expression and inhibition efficiency. In particular, we identify the σ66-dependent promoter that controls cPDF gene expression and demonstrate that point mutations in this promoter lead to resistance by increasing cPDF transcription. Furthermore, we show that substitution of two amino acids near the active site of the enzyme alters enzyme kinetics and protein stability. PMID:21719536

Equilibrium of molybdenum in selected extraction systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tkac, Peter; Paulenova, Alena

2007-07-01

The concentration of molybdenum(VI) in dissolved irradiated nuclear fuel is comparable with the concentrations of Tc, Am and Np. Therefore it is of big interest to understand its behavior under conditions related to the UREX/TRUEX process. The effect of the poly-speciation of molybdenum in aqueous solution on its extraction by neutral solvents TBP and CMPO/TBP was studied. Extraction yields of molybdenum decreased significantly when AHA was added to aqueous phase. Our investigation confirmed a strong ability of the aceto-hydroxamic acid to form complexes with Mo in high acidic solutions. Spectroscopic data (UV-Vis) confirmed that a fraction of the Mo(VI)-AHA complexmore » is present in the organic phase after extraction. (authors)« less

Infrared multiple photon dissociation spectroscopy of group I and group II metal complexes with Boc-hydroxylamine.

PubMed

Dain, Ryan P; Gresham, Gary; Groenewold, Gary S; Steill, Jeffrey D; Oomens, Jos; Van Stipdonk, Michael J

2013-08-30

Hydroxamates are essential growth factors for some microbes, acting primarily as siderophores that solubilize iron for transport into a cell. Here we determined the intrinsic structure of 1:1 complexes between Boc-protected hydroxylamine and group I ([M(L)](+)) and group II ([M(L-H)](+)) cations, where M and L are the cation and ligand, respectively, which are convenient models for the functional unit of hydroxamate siderphores. The relevant complex ions were generated by electrospray ionization (ESI) and isolated and stored in a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. Infrared spectra of the isolated complexes were collected by monitoring (infrared) photodissociation yield as a function of photon energy. Experimental spectra were then compared to those predicted by density functional theory (DFT) calculations. The infrared multiple photon dissociation (IRMPD) spectra collected are in good agreement with those predicted to be lowest-energy by DFT. The spectra for the group I complexes contain six resolved absorptions that can be attributed to amide I and II type and hydroxylamine N-OH vibrations. Similar absorptions are observed for the group II cation complexes, with shifts of the amide I and amide II vibrations due to the change in structure with deprotonation of the hydroxylamine group. IRMPD spectroscopy unequivocally shows that the intrinsic binding mode for the group I cations involves the O atoms of the amide carbonyl and hydroxylamine groups of Boc-hydroxylamine. A similar binding mode is preferred for the group II cations, except that in this case the metal ion is coordinated by the O atom of the deprotonated hydroxylamine group. Copyright © 2013 John Wiley & Sons, Ltd.

Impact of the uranium (VI) speciation in mineralised urines on its extraction by calix[6]arene bearing hydroxamic groups used in chromatography columns.

PubMed

Baghdadi, S; Bouvier-Capely, C; Ritt, A; Peroux, A; Fevrier, L; Rebiere, F; Agarande, M; Cote, G

2015-11-01

Actinides determination in urine samples is part of the analyses performed to monitor internal contamination in case of an accident or a terrorist attack involving nuclear matter. Mineralisation is the first step of any of these analyses. It aims at reducing the sample volume and at destroying all organic compounds present. The mineralisation protocol is usually based on a wet ashing step, followed by actinides co-precipitation and a furnace ashing step, before redissolution and the quantification of the actinides by the appropriate techniques. Amongst the existing methods to perform the actinides co-precipitation, alkali-earth (typically calcium) precipitation is widely used. In the present work, the extraction of uranium(VI), plutonium(IV) and americium(III) from the redissolution solutions (called "mineralised urines") on calix[6]arene columns bearing hydroxamic groups was investigated as such an extraction is a necessary step before their determination by ICP-MS or alpha spectrometry. Difficulties were encountered in the transfer of uranium(VI) from raw to mineralised urines, with yield of transfer ranging between 0% and 85%, compared to about 90% for Pu and Am, depending on the starting raw urines. To understand the origin of such a difficulty, the speciation of uranium (VI) in mineralised urines was investigated by computer simulation using the MEDUSA software and the associated HYDRA database, compiled with recently published data. These calculations showed that the presence of phosphates in the "mineralised urines" leads to the formation of strong uranyl-phosphate complexes (such as UO2HPO4) which compete with the uranium (VI) extraction by the calix[6]arene bearing hydroxamic groups. The extraction constant of uranium (VI) by calix[6]arene bearing hydroxamic groups was determined in a 0.04 mol L(-1) sodium nitrate solution (logK=4.86±0.03) and implemented in an extraction model taking into account the speciation in the aqueous phase. This model allowed to simulate satisfactorily the experimental uranium extraction data and to support the preliminary conclusions about the role of the phosphates present in mineralised urines. These calculations also showed that the phosphate/calcium ratio is a key parameter as far as the efficiency of the uranium (VI) extraction by the calix[6]arene columns is concerned. It predicted that the addition of CaCl2 in mineralised urines would release uranium (VI) from phosphates by forming calcium (II)-phosphate complexes and thus facilitate the uranium (VI) extraction on calix[6]arene columns. These predictions were confirmed experimentally as the addition of 0.1 mol L(-1) CaCl2 to a mineralised urine containing naturally a high concentration of phosphate (typically 0.04 mol L(-1)) significantly increased the percentage of uranium (VI) extraction on the calix[6]arene columns. Copyright © 2015 Elsevier B.V. All rights reserved.

Overview of reductants utilized in nuclear fuel reprocessing/recycling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patricia Paviet-Hartmann; Catherine Riddle; Keri Campbell

2013-10-01

Most of the aqueous processes developed, or under consideration worldwide for the recycling of used nuclear fuel (UNF) utilize the oxido-reduction properties of actinides to separate them from other radionuclides. Generally, after acid dissolution of the UNF, (essentially in nitric acid solution), actinides are separated from the raffinate by liquid-liquid extraction using specific solvents, associated along the process, with a particular reductant that will allow the separation to occur. For example, the industrial PUREX process utilizes hydroxylamine as a plutonium reductant. Hydroxylamine has numerous advantages: not only does it have the proper attributes to reduce Pu(IV) to Pu(III), but itmore » is also a non-metallic chemical that is readily decomposed to innocuous products by heating. However, it has been observed that the presence of high nitric acid concentrations or impurities (such as metal ions) in hydroxylamine solutions increase the likelihood of the initiation of an autocatalytic reaction. Recently there has been some interest in the application of simple hydrophilic hydroxamic ligands such as acetohydroxamic acid (AHA) for the stripping of tetravalent actinides in the UREX process flowsheet. This approach is based on the high coordinating ability of hydroxamic acids with tetravalent actinides (Np and Pu) compared with hexavalent uranium. Thus, the use of AHA offers a route for controlling neptunium and plutonium in the UREX process by complexant based stripping of Np(IV) and Pu(IV) from the TBP solvent phase, while U(VI) ions are not affected by AHA and remain solvated in the TBP phase. In the European GANEX process, AHA is also used to form hydrophilic complexes with actinides and strip them from the organic phase into nitric acid. However, AHA does not decompose completely when treated with nitric acid and hampers nitric acid recycling. In lieu of using AHA in the UREX + process, formohydroxamic acid (FHA), although not commercially available, hold promises as a replacement for AHA. FHA undergoes hydrolysis to formic acid which is volatile, thus allowing the recycling of nitric acid. Unfortunately, FHA powder was not stable in the experiments we ran in our laboratory. In addition, AHA and FHA also decompose to hydroxylamine which may undergo an autocatalytic reaction. Other reductants are available and could be extremely useful for actinides separation. The review presents the current plutonium reductants used in used nuclear fuel reprocessing and will introduce innovative and novel reductants that could become reducers for future research on UNF separation.« less

Suberoylanilide hydroxamic acid increases anti-cancer effect of tumor necrosis factor-α through up-regulation of TNF receptor 1 in lung cancer cells.

PubMed

You, Bo Ra; Han, Bo Ram; Park, Woo Hyun

2017-03-14

Suberoylanilide hydroxamic acid (SAHA) as a histone deacetylase (HDAC) inhibitor has anti-cancer effect. Here, we evaluated the effect of SAHA on HDAC activity and cell growth in many normal lung and cancer cells. We observed that the HDAC activities of lung cancer cells were higher than that of normal lung cells. SAHA inhibited the growth of lung cancer cells regardless of the inhibitory effect on HDAC. This agent induced a G2/M phase arrest and apoptosis, which was accompanied by mitochondrial membrane potential (MMP: ΔΨm) loss in lung cancer cells. However, SAHA did not induce cell death in normal lung cells. All tested caspase inhibitors prevented apoptotic cell death in SAHA-treated A549 and Calu-6 lung cancer cells. Treatment with tumor necrosis factor-alpha (TNF-α) enhanced apoptosis in SAHA-treated lung cancer cells through caspase-8 and caspase-9 activations. Especially, SAHA increased the expression level of TNF-α receptor 1 (TNFR1), especially acetylation of the region of TNFR1 promoter -223/-29 in lung cancer cells. The down-regulation of TNFR1 suppressed apoptosis in TNF-α and SAHA-treated lung cancer cells. In conclusion, SAHA inhibited the growth of lung cancer cells via a G2/M phase arrest and caspase-dependent apoptosis. SAHA also enhanced apoptotic effect of TNF-α in human lung cancer cells through up-regulation of TNFR1. TNF-α may be a key to improve anti-cancer effect of HDAC inhibitors.

A novel histone deacetylase inhibitor, CG200745, potentiates anticancer effect of docetaxel in prostate cancer via decreasing Mcl-1 and Bcl-XL.

PubMed

Hwang, Jung Jin; Kim, Yong Sook; Kim, Taelim; Kim, Mi Joung; Jeong, In Gab; Lee, Je-Hwan; Choi, Jene; Jang, Sejin; Ro, Seonggu; Kim, Choung-Soo

2012-08-01

We synthesized a novel hydroxamate-based pan-histone deacetylase inhibitor (HDACI), CG200745 {(E)-2-(Naphthalen-1-yloxymethyl)-oct-2-enedioic acid 1-[(3-dimethylamino-propyl)-amide] 8-hydroxyamide]}. Like other inhibitors, for example vorinostat and belinostat, CG200745 has the hydroxamic acid moiety to bind zinc at the bottom of catalytic pocket. Firstly, we analyzed its inhibitory activity against histone deacetylase (HDAC) in hormone-dependent LNCaP cells and hormone-independent DU145 and PC3 cells. CG200745 inhibited deacetylation of histone H3 and tubulin as much as vorinostat and belinostat did. CG200745 also inhibited growth of prostate cancer cells, increased sub-G1 population, and activated caspase-9, -3 and -8 in LNCaP, DU145 and PC3 cells. These results indicate that CG200745 induces apoptosis. Next, we examined the effect of CG200745 on cell death induced by docetaxel in DU145 cells in vitro and in vivo. Compared to mono-treatment with each drug, pre-treatment of DU145 cells with docetaxel followed by CG200745 showed synergistic cytotoxicity, and increased the apoptotic sub-G1 population, caspase activation, and tubulin acetylation. Moreover, the combination treatment decreased Mcl-1 and Bcl-(XL). Docetaxel and CG200745 combination reduced tumor size in the DU145 xenograft model. These preclinical results show that combination treatment with docetaxel and new HDACI, CG200745, potentiated anti-tumor effect in hormone-refractory prostate cancer (HRPC) cells via activation of apoptosis.

Structure of ‘linkerless’ hydroxamic acid inhibitor-HDAC8 complex confirms the formation of an isoform-specific subpocket

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tabackman, Alexa A.; Frankson, Rochelle; Marsan, Eric S.

Histone deacetylases (HDACs) catalyze the hydrolysis of acetylated lysine side chains in histone and non-histone proteins, and play a critical role in the regulation of many biological processes, including cell differentiation, proliferation, senescence, and apoptosis. Aberrant HDAC activity is associated with cancer, making these enzymes important targets for drug design. In general, HDAC inhibitors (HDACi) block the proliferation of tumor cells by inducing cell differentiation, cell cycle arrest, and/or apoptosis, and comprise some of the leading therapies in cancer treatments. To date, four HDACi have been FDA approved for the treatment of cancers: suberoylanilide hydroxamic acid (SAHA, Vorinostat, Zolinza®), romidepsinmore » (FK228, Istodax®), belinostat (Beleodaq®), and panobinostat (Farydak®). Most current inhibitors are pan-HDACi, and non-selectively target a number of HDAC isoforms. Six previously reported HDACi were rationally designed, however, to target a unique sub-pocket found only in HDAC8. While these inhibitors were indeed potent against HDAC8, and even demonstrated specificity for HDAC8 over HDACs 1 and 6, there were no structural data to confirm the mode of binding. Here we report the X-ray crystal structure of Compound 6 complexed with HDAC8 to 1.98 Å resolution. We also describe the use of molecular docking studies to explore the binding interactions of the other 5 related HDACi. Our studies confirm that the HDACi induce the formation of and bind in the HDAC8-specific subpocket, offering insights into isoform-specific inhibition.« less

Suberoylanilide hydroxamic acid increases anti-cancer effect of tumor necrosis factor-α through up-regulation of TNF receptor 1 in lung cancer cells

PubMed Central

You, Bo Ra; Han, Bo Ram; Park, Woo Hyun

2017-01-01

Suberoylanilide hydroxamic acid (SAHA) as a histone deacetylase (HDAC) inhibitor has anti-cancer effect. Here, we evaluated the effect of SAHA on HDAC activity and cell growth in many normal lung and cancer cells. We observed that the HDAC activities of lung cancer cells were higher than that of normal lung cells. SAHA inhibited the growth of lung cancer cells regardless of the inhibitory effect on HDAC. This agent induced a G2/M phase arrest and apoptosis, which was accompanied by mitochondrial membrane potential (MMP: ΔΨm) loss in lung cancer cells. However, SAHA did not induce cell death in normal lung cells. All tested caspase inhibitors prevented apoptotic cell death in SAHA-treated A549 and Calu-6 lung cancer cells. Treatment with tumor necrosis factor-alpha (TNF-α) enhanced apoptosis in SAHA-treated lung cancer cells through caspase-8 and caspase-9 activations. Especially, SAHA increased the expression level of TNF-α receptor 1 (TNFR1), especially acetylation of the region of TNFR1 promoter −223/-29 in lung cancer cells. The down-regulation of TNFR1 suppressed apoptosis in TNF-α and SAHA-treated lung cancer cells. In conclusion, SAHA inhibited the growth of lung cancer cells via a G2/M phase arrest and caspase-dependent apoptosis. SAHA also enhanced apoptotic effect of TNF-α in human lung cancer cells through up-regulation of TNFR1. TNF-α may be a key to improve anti-cancer effect of HDAC inhibitors. PMID:28099148

Consumption and utilization of experimentally altered corn by southern armyworm: Iron, nitrogen, and cyclic hydroxamates.

PubMed

Manuwoto, S; Scriber, J M

1985-11-01

The effects of differential leaf water, leaf nitrogen and cyclic hydroxamate (DIMBOA) concentrations in corn seedlings were analyzed for a polyphagous insect, the southern armyworm (Spodoptera eridania Cram.). Six different combinations of nutrients and allelochemicals [DIMBOA = 2,4-dihydroxy-7-methoxy(2H)-benzoxazin-3(4H)-one] were generated using two corn genotypes (WF9 and CI3IA) and three fertility regimes (complete nutrient, Fe-deficient, and N-deficient solutions) in the University Biotron. Poorest larval growth was observed in the low-nitrogen treatments (1.2% and 1.7% leaf N) and was the result of both low consumption rates and high metabolic costs (low efficiency of conversion of digested food, ECD). Fastest growth rates were observed forthe larvae fed leaves from the high-nitrogen treatments (4.6% and 4.4% leaf N). It is noteworthy that these treatments also contained the highest concentration of cyclic hydroxamates, which are generally believed to be the primary defensive chemicals mediating resistance against the European corn borer,Ostrinia nubilalis (Hubner). If these hydroxamates do have any deleterious or costly effects (perhaps accounting for a large portion of metabolic expenditures), the high digestibility of the leaf tissue and the increased consumption rates more than compensate, resulting in rapid growth (growth rate = consumption rate × approximate digestibility × efficiency of conversion of the digested food). These studies illustrate that variation in key nutrients and allelochemicals within a single plant species (Zea mays L.) may have significantly different effects upon various potential leaf-chewing caterpillars, such as these armyworms versus corn borers (which cannot handle the cyclic hydroxamates, even if provided with young nutritious leaf tissues).

Adsorption of Salicylhydroxamic Acid on Selected Rare Earth Oxides and Carbonates

NASA Astrophysics Data System (ADS)

Galt, Greer Elaine

Adsorption behavior of the anionic collector salicylhydroxamic acid (SHA) on a selected group of rare earth oxides (REOs) and carbonates (RECs) was studied via experimental methods and modelling software. Synthetic oxide and carbonate powders of the rare earth elements cerium (Ce), praseodymium (Pr), europium (Eu), and terbium (Tb) were tested for this research. Studies were conducted at different pH levels to analyze the kinetics of collector adsorption onto the oxide and carbonate surfaces in attempts to optimize recovery parameters for commercial flotation processes using SHA. In addition, thermodynamic software StabCal was implemented to compare theoretical adsorption behavior of collectors SHA and octylhydroxamic acid (OHA) on these four rare earth oxides and carbonates. Theoretical points of zero charge were also estimated via StabCal and compared to experimental values to establish validity. Results for oxides indicate that both the amount and rate of SHA adsorption are highest for lighter REOs, decreasing as ionic diameter increases, a chelation phenomenon common with hydroxamates. However, results for the carbonates exhibit the opposite trend: strongest SHA adsorption was seen in the heavy RECs. This pattern correlates to the increasing stability of the carbonate such that ionic diameter of the REs becomes more amenable to chelation due to differences in bonding chemistry. Overall, adsorption kinetics appear dependent on pH, coordination chemistry, and cation size.

Synthesis, antimalarial properties, and SAR studies of alkoxyurea-based HDAC inhibitors.

PubMed

Hansen, Finn K; Skinner-Adams, Tina S; Duffy, Sandra; Marek, Linda; Sumanadasa, Subathdrage D M; Kuna, Krystina; Held, Jana; Avery, Vicky M; Andrews, Katherine T; Kurz, Thomas

2014-03-01

Histone deacetylase (HDAC) inhibitors are an emerging class of potential antimalarial drugs. We investigated the antiplasmodial properties of 16 alkoxyurea-based HDAC inhibitors containing various cap and zinc binding groups (ZBGs). Ten compounds displayed sub-micromolar activity against the 3D7 line of Plasmodium falciparum. Structure-activity relationship studies revealed that a hydroxamic acid ZBG is crucial for antiplasmodial activity, and that the introduction of bulky alkyl substituents to cap groups increases potency against asexual blood-stage parasites. We also demonstrate that selected compounds cause hyperacetylation of P. falciparum histone H4, indicating inhibition of one or more PfHDACs. To assess the selectivity of alkoxyurea-based HDAC inhibitors for parasite over normal mammalian cells, the cytotoxicity of representative compounds was evaluated against neonatal foreskin fibroblast (NFF) cells. The most active compound, 6-((3-(4-(tert-butyl)phenyl)ureido)oxy)-N-hydroxyhexanamide (1 e, Pf3D7 IC50 : 0.16 μM) was 31-fold more toxic against the asexual blood stages than towards normal mammalian cells. Moreover, a subset of four structurally diverse HDAC inhibitors revealed moderate activity against late-stage (IV-V) gametocytes. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Suberoylanilide hydroxamic acid, an inhibitor of histone deacetylase, suppresses vasculogenic mimicry and proliferation of highly aggressive pancreatic cancer PaTu8988 cells

PubMed Central

2014-01-01

Background Pancreatic cancer is one of the most aggressive human malignancies with a extremely low 5-year survival rate. Hence, the search for more effective anti-pancreatic cancer agents is urgent. Methods PaTu8988 pancreatic cancer cells were treated with different concentrations of suberoylanilide hydroxamic acid (SAHA), cell survival, proliferation, migration and vasculogenic mimicry (VM) were analyzed. Associated signaling changes were also analyzed by RT-PCR and Western blots. Results Here, we reported that SAHA, a histone deacetylase inhibitor (HDACi), exerted significant inhibitory efficiency against pancreatic cancer cell survival, proliferation, migration and VM. SAHA dose-dependently inhibited PaTu8988 pancreatic cancer cell growth with the IC-50 of 3.4 ± 0. 7 μM. Meanwhile, SAHA suppressed PaTu8988 cell cycle progression through inducing G2/M arrest, which was associated with cyclin-dependent kinase 1 (CDK-1)/cyclin-B1 degradation and p21/p27 upregulation. Further, SAHA induced both apoptotic and non-apoptotic death of PaTu8988 cells. Significantly, SAHA suppressed PaTu8988 cell in vitro migration and cell-dominant tube formation or VM, which was accompanied by semaphorin-4D (Sema-4D) and integrin-β5 down-regulation. Our evidences showed that Akt activation might be important for Sema-4D expression in PaTu8988 cells, and SAHA-induced Sema-4D down-regulation might be associated with Akt inhibition. Conclusions This study is among the first to report the VM formation in cultured human pancreatic cancer cells. And we provided strong evidence to suggest that SAHA executes significant anti-VM efficiency in the progressive pancreatic cancer cells. Thus, SAHA could be further investigated as a promising anti-pancreatic cancer agent. PMID:24886166

Effect of Suberoylanilide Hydroxamic Acid (SAHA) Administration on the Residual Virus Pool in a Model of Combination Antiretroviral Therapy-Mediated Suppression in SIVmac239-Infected Indian Rhesus Macaques

PubMed Central

Del Prete, Gregory Q.; Shoemaker, Rebecca; Oswald, Kelli; Lara, Abigail; Trubey, Charles M.; Fast, Randy; Schneider, Douglas K.; Kiser, Rebecca; Coalter, Vicky; Wiles, Adam; Wiles, Rodney; Freemire, Brandi; Keele, Brandon F.; Estes, Jacob D.; Quiñones, Octavio A.; Smedley, Jeremy; Macallister, Rhonda; Sanchez, Rosa I.; Wai, John S.; Tan, Christopher M.; Alvord, W. Gregory; Hazuda, Daria J.; Piatak, Michael

2014-01-01

Nonhuman primate models are needed for evaluations of proposed strategies targeting residual virus that persists in HIV-1-infected individuals receiving suppressive combination antiretroviral therapy (cART). However, relevant nonhuman primate (NHP) models of cART-mediated suppression have proven challenging to develop. We used a novel three-class, six-drug cART regimen to achieve durable 4.0- to 5.5-log reductions in plasma viremia levels and declines in cell-associated viral RNA and DNA in blood and tissues of simian immunodeficiency virus SIVmac239-infected Indian-origin rhesus macaques, then evaluated the impact of treatment with the histone deacetylase inhibitor (HDACi) suberoylanilide hydroxamic acid (SAHA; Vorinostat) on the residual virus pool. Ex vivo SAHA treatment of CD4+ T cells obtained from cART-suppressed animals increased histone acetylation and viral RNA levels in culture supernatants. cART-suppressed animals each received 84 total doses of oral SAHA. We observed SAHA dose-dependent increases in acetylated histones with evidence for sustained modulation as well as refractoriness following prolonged administration. In vivo virologic activity was demonstrated based on the ratio of viral RNA to viral DNA in peripheral blood mononuclear cells, a presumptive measure of viral transcription, which significantly increased in SAHA-treated animals. However, residual virus was readily detected at the end of treatment, suggesting that SAHA alone may be insufficient for viral eradication in the setting of suppressive cART. The effects observed were similar to emerging data for repeat-dose SAHA treatment of HIV-infected individuals on cART, demonstrating the feasibility, utility, and relevance of NHP models of cART-mediated suppression for in vivo assessments of AIDS virus functional cure/eradication approaches. PMID:25182644

Overview of reductants utilized in nuclear fuel reprocessing/recycling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paviet-Hartmann, P.; Riddle, C.; Campbell, K.

2013-07-01

The most widely used reductant to partition plutonium from uranium in the Purex process was ferrous sulfamate, other alternates were proposed such as hydrazine-stabilized ferrous nitrate or uranous nitrate, platinum catalyzed hydrogen, and hydrazine, hydroxylamine salts. New candidates to replace hydrazine or hydroxylamine nitrate (HAN) are pursued worldwide. They may improve the performance of the industrial Purex process towards different operations such as de-extraction of plutonium and reduction of the amount of hydrazine which will limit the formation of hydrazoic acid. When looking at future recycling technologies using hydroxamic ligands, neither acetohydroxamic acid (AHA) nor formohydroxamic acid (FHA) seem promisingmore » because they hydrolyze to give hydroxylamine and the parent carboxylic acid. Hydroxyethylhydrazine, HOC{sub 2}H{sub 4}N{sub 2}H{sub 3} (HEH) is a promising non-salt-forming reductant of Np and Pu ions because it is selective to neptunium and plutonium ions at room temperature and at relatively low acidity, it could serve as a replacement of HAN or AHA for the development of a novel used nuclear fuel recycling process.« less

Studies on the mucin derived from human colloid breast carcinoma

PubMed Central

Adams, J. B.

1965-01-01

1. A non-diffusible mucoid, showing a single peak in the ultracentrifuge, was isolated from human colloid breast carcinoma by treatment with trypsin and pepsin. The material contained threonine, leucine (isoleucine), valine, proline, glycine and glutamic acid in the approximate molar proportions 5:1:1:2:1:1. Smaller amounts of aspartic acid and serine were also found. For each 5 threonine residues, 6 N-acetylgalactosamine and 3–4 galactose residues were present. 2. The mucoid possessed reducing properties by the Park & Johnson (1949) procedure; these were attributable to the action of mild alkali, as employed in this procedure. Mild alkaline treatment by the Aminoff, Morgan & Watkins (1952) procedure gave rise to a diffusible N-acetylgalactosamine chromophore that gave an enhanced colour with Ehrlich's reagent. That galactosyl-(1→3)-N-acetylgalactosamine residues were liberated was supported by periodate studies. 3. Alkaline liberation of hexosamine residues was accompanied by a specific destruction of threonine. After 40 min. at 100° in 0·18 n-lithium hydroxide, both moieties had almost completely disappeared from the ninhydrin-positive components formed on subsequent acid hydrolysis. Glycine and α-oxobutyric acid were present in the acid hydrolysate, showing that both possible pathways of a β-elimination reaction were involved. Formation of diffusible peptide on very mild alkaline treatment was attributable to the rupture of the original peptide core, necessitated by the second of these two pathways. 4. Hydroxamate formation on treatment with hydroxylamine showed the presence of carbohydrate linkage to glutamic acid or aspartic acid residues or both. This could account for the single N-acetylgalactosamine residue not linked to threonine. 5. The native mucin contained sialic acid, which was cleaved by the acid environment used in the treatment with pepsin. A statistical model of the mucin would require each prosthetic group to be linked, via N-acetylgalactosamine, to threonine, which would occupy every alternate position among the amino acids in the peptide core. ImagesFig. 1.Fig. 4. PMID:14348196

Evolution of siderophore pathways in human pathogenic bacteria.

PubMed

Franke, Jakob; Ishida, Keishi; Hertweck, Christian

2014-04-16

Ornibactin and malleobactin are hydroxamate siderophores employed by human pathogenic bacteria belonging to the genus Burkholderia. Similarities in their structures and corresponding biosynthesis gene clusters strongly suggest an evolutionary relationship. Through gene coexpression and targeted gene manipulations, the malleobactin pathway was successfully morphed into an ornibactin assembly line. Such an evolutionary-guided approach has been unprecedented for nonribosomal peptide synthetases. Furthermore, the timing of amino acid acylation before peptide assembly, the absolute configuration of the ornibactin side chain, and the function of the acyl transferase were elucidated. Beyond providing a proof of principle for the rational design of siderophore pathways, a compelling model for the evolution of virulence traits is presented.

Hematologic Response to Vorinostat Treatment in Relapsed Myeloid Leukemia of Down Syndrome.

PubMed

Scheer, Carina; Kratz, Christian; Witt, Olaf; Creutzig, Ursula; Reinhardt, Dirk; Klusmann, Jan-Henning

2016-09-01

Children with Down syndrome are at high risk to develop myeloid leukemia (ML-DS). Despite their excellent prognosis, children with ML-DS particularly suffer from severe therapy-related toxicities and for relapsed ML-DS the cure rates are very poor. Here we report the clinical course of one child with ML-DS treated with the histone deacetylase (HDAC) inhibitor vorinostat (suberoylanilide hydroxamic acid) after second relapse. The child had previously received conventional chemotherapy and stem cell transplantation, yet showed a remarkable clinical and hematologic response. Thus, HDAC inhibitor may represent an effective class of drugs for the treatment of ML-DS. © 2016 Wiley Periodicals, Inc.

Trihydroxamate siderophore-fluoroquinolone conjugates are selective sideromycin antibiotics that target Staphylococcus aureus.

PubMed

Wencewicz, Timothy A; Long, Timothy E; Möllmann, Ute; Miller, Marvin J

2013-03-20

Siderophores are multidentate iron(III) chelators used by bacteria for iron assimilation. Sideromycins, also called siderophore-antibiotic conjugates, are a unique subset of siderophores that enter bacterial cells via siderophore uptake pathways and deliver the toxic antibiotic in a "Trojan horse" fashion. Sideromycins represent a novel antibiotic delivery technology with untapped potential for developing sophisticated microbe-selective antibacterial agents that limit the emergence of bacterial resistance. The chemical synthesis of a series of mono-, bis-, and trihydroxamate sideromycins are described here along with their biological evaluation in antibacterial susceptibility assays. The linear hydroxamate siderophores used for the sideromycins in this study were derived from the ferrioxamine family and inspired by the naturally occurring salmycin sideromycins. The antibacterial agents used were a β-lactam carbacepholosporin, Lorabid, and a fluoroquinolone, ciprofloxacin, chosen for the different locations of their biological targets, the periplasm (extracellular) and the cytoplasm (intracellular). The linear hydroxamate-based sideromycins were selectively toxic toward Gram-positive bacteria, especially Staphylococcus aureus SG511 (MIC = 1.0 μM for the trihydroxamate-fluoroquinolone sideromycin). Siderophore-sideromycin competition assays demonstrated that only the fluoroquinolone sideromycins required membrane transport to reach their cytoplasmic biological target and that a trihydroxamate siderophore backbone was required for protein-mediated active transport of the sideromycins into S. aureus cells via siderophore uptake pathways. This work represents a comprehensive study of linear hydroxamate sideromycins and teaches how to build effective hydroxamate-based sideromycins as Gram-positive selective antibiotic agents.

Study on the spectrophotometric detection of free fatty acids in palm oil utilizing enzymatic reactions.

PubMed

Azeman, Nur Hidayah; Yusof, Nor Azah; Abdullah, Jaafar; Yunus, Robiah; Hamidon, Mohd Nizar; Hajian, Reza

2015-07-07

In this paper, a comprehensive study has been made on the detection of free fatty acids (FFAs) in palm oil via an optical technique based on enzymatic aminolysis reactions. FFAs in crude palm oil (CPO) were converted into fatty hydroxamic acids (FHAs) in a biphasic lipid/aqueous medium in the presence of immobilized lipase. The colored compound formed after complexation between FHA and vanadium (V) ion solution was proportional to the FFA content in the CPO samples and was analyzed using a spectrophotometric method. In order to develop a rapid detection system, the parameters involved in the aminolysis process were studied. The utilization of immobilized lipase as catalyst during the aminolysis process offers simplicity in the product isolation and the possibility of conducting the process under extreme reaction conditions. A good agreement was found between the developed method using immobilized Thermomyces lanuginose lipase as catalyst for the aminolysis process and the Malaysian Palm Oil Board (MPOB) standard titration method (R2 = 0.9453).

Process for the displacement of cyanide ions from metal-cyanide complexes

DOEpatents

Smith, Barbara F.; Robinson, Thomas W.

1997-01-01

The present invention relates to water-soluble polymers and the use of such water-soluble polymers in a process for the displacement of the cyanide ions from the metal ions within metal-cyanide complexes. The process waste streams can include metal-cyanide containing electroplating waste streams, mining leach waste streams, mineral processing waste streams, and related metal-cyanide containing waste streams. The metal ions of interest are metals that give very strong complexes with cyanide, mostly iron, nickel, and copper. The physical separation of the water-soluble polymer-metal complex from the cyanide ions can be accomplished through the use of ultrafiltration. Once the metal-cyanide complex is disrupted, the freed cyanide ions can be recovered for reuse or destroyed using available oxidative processes rendering the cyanide nonhazardous. The metal ions are released from the polymer, using dilute acid, metal ion oxidation state adjustment, or competing chelating agents, and collected and recovered or disposed of by appropriate waste management techniques. The water-soluble polymer can then be recycled. Preferred water-soluble polymers include polyethyleneimine and polyethyleneimine having a catechol or hydroxamate group.

Prevention of acetic acid-induced colitis by desferrithiocin analogs in a rat model.

PubMed

Bergeron, Raymond J; Wiegand, Jan; Weimar, William R; Nguyen, John Nhut; Sninsky, Charles A

2003-02-01

Iron contributes significantly to the formation of reactive oxygen species via the Fenton reaction. Therefore, we assessed whether a series of desferrithiocin analogs, both carboxylic acids and hydroxamates, could (1) either promote or diminish the iron-mediated oxidation of ascorbate, (2) quench a model radical species, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+), and (3) when applied topically, prevent acetic acid-induced colitis in rats. Surprisingly, most of the desferrithiocin analogs inhibited the Fenton reaction to an approximately equivalent degree; however, substantial differences were observed in the capacity of the analogs to scavenge the model radical cation. Four carboxylic acid desferrithiocin analogs and their respective N-methylhydroxamates were tested along with desferrioxamine and Rowasa, a currently accepted topical therapeutic agent for inflammatory bowel disease (IBD), in a rodent model of acetic acid-induced colitis. The colonic damage was quantitated by two independent measurements. Although neither radical scavenging nor prevention of Fenton chemistry was a definitive predictor of in vivo efficacy, the overall trend is that desferrithiocin analogs substituted with an N-methylhydroxamate in the place of the carboxylic acid are both better free radical scavengers and more active against acetic acid-induced colitis. These results represent an intriguing alternative avenue to the development of improved IBD therapeutic agents.

Foam and gel methods for the decontamination of metallic surfaces

DOEpatents

Nunez, Luis; Kaminski, Michael Donald

2007-01-23

Decontamination of nuclear facilities is necessary to reduce the radiation field during normal operations and decommissioning of complex equipment. In this invention, we discuss gel and foam based diphosphonic acid (HEDPA) chemical solutions that are unique in that these solutions can be applied at room temperature; provide protection to the base metal for continued applications of the equipment; and reduce the final waste form production to one step. The HEDPA gels and foams are formulated with benign chemicals, including various solvents, such as ionic liquids and reducing and complexing agents such as hydroxamic acids, and formaldehyde sulfoxylate. Gel and foam based HEDPA processes allow for decontamination of difficult to reach surfaces that are unmanageable with traditional aqueous process methods. Also, the gel and foam components are optimized to maximize the dissolution rate and assist in the chemical transformation of the gel and foam to a stable waste form.

Identification of novel potential scaffold for class I HDACs inhibition: An in-silico protocol based on virtual screening, molecular dynamics, mathematical analysis and machine learning.

PubMed

Fan, Cong; Huang, Yanxin

2017-09-23

Histone deacetylases (HDACs) family has been widely reported as an important class of enzyme targets for cancer therapy. Much effort has been made in discovery of novel scaffolds for HDACs inhibition besides existing hydroxamic acids, cyclic peptides, benzamides, and short-chain fatty acids. Herein we set up an in-silico protocol which not only could detect potential Zn 2+ chelation bonds but also still adopted non-bonded model to be effective in discovery of Class I HDACs inhibitors, with little human's subjective visual judgment involved. We applied the protocol to screening of Chembridge database and selected out 7 scaffolds, 3 with probability of more than 99%. Biological assay results demonstrated that two of them exhibited HDAC-inhibitory activity and are thus considerable for structure modification to further improve their bio-activity. Copyright © 2017. Published by Elsevier Inc.

Growth stimulation of Brevibacterium sp. by siderophores.

PubMed

Noordman, W H; Reissbrodt, R; Bongers, R S; Rademaker, J L W; Bockelmann, W; Smit, G

2006-09-01

To assess which types of siderophores are typically produced by Brevibacterium and how siderophore production and utilization traits are distributed within this genus. During co-cultivation experiments it was found that growth of B. linens Br5 was stimulated by B. linens NIZO B1410 by two orders of magnitude. The stimulation was caused by the production of hydroxamate siderophores by B. linens NIZO B1410 that enabled the siderophore-auxotrophic strain Br5 to grow faster under the applied iron-limited growth conditions. Different patterns of siderophore production and utilization were observed within the genus Brevibacterium. These patterns did not reflect the phylogenetic relations within the group as determined by partial 16S rDNA sequencing. Most Brevibacterium strains were found to utilize hydroxamate siderophores. Brevibacteria can produce and utilize siderophores although certain strains within this genus are siderophore-auxotrophic. It is reported for the first time that brevibacteria produce and utilize siderophores. This knowledge can be utilized to stimulate growth of auxotrophic strains under certain conditions. Enhancing the growth rate of Brevibacterium is of importance for the application of this species, for example, for cheese manufacturing or for industrial production of enzymes or metabolites.

A Novel Hydroxamate-Based Compound WMJ-J-09 Causes Head and Neck Squamous Cell Carcinoma Cell Death via LKB1-AMPK-p38MAPK-p63-Survivin Cascade.

PubMed

Yen, Chia-Sheng; Choy, Cheuk-Sing; Huang, Wei-Jan; Huang, Shiu-Wen; Lai, Pin-Ye; Yu, Meng-Chieh; Shiue, Ching; Hsu, Ya-Fen; Hsu, Ming-Jen

2018-01-01

Growing evidence shows that hydroxamate-based compounds exhibit broad-spectrum pharmacological properties including anti-tumor activity. However, the precise mechanisms underlying hydroxamate derivative-induced cancer cell death remain incomplete understood. In this study, we explored the anti-tumor mechanisms of a novel aliphatic hydroxamate-based compound, WMJ-J-09, in FaDu head and neck squamous cell carcinoma (HNSCC) cells. WMJ-J-09 induced G2/M cell cycle arrest and apoptosis in FaDu cells. These actions were associated with liver kinase B1 (LKB1), AMP-activated protein kinase (AMPK) and p38 mitogen-activated protein kinase (p38MAPK) activation, transcription factor p63 phosphorylation, as well as modulation of p21 and survivin. LKB1-AMPK-p38MAPK signaling blockade reduced WMJ-J-09's enhancing effects in p63 phosphorylation, p21 elevation and survivin reduction. Moreover, WMJ-J-09 caused an increase in α-tubulin acetylation and interfered with microtubule assembly. Furthermore, WMJ-J-09 suppressed the growth of subcutaneous FaDu xenografts in vivo . Taken together, WMJ-J-09-induced FaDu cell death may involve LKB1-AMPK-p38MAPK-p63-survivin signaling cascade. HDACs inhibition and disruption of microtubule assembly may also contribute to WMJ-J-09's actions in FaDu cells. This study suggests that WMJ-J-09 may be a potential lead compound and warrant the clinical development in the treatment of HNSCC.

Histone Deacetylase (HDAC) Inhibitor Kinetic Rate Constants Correlate with Cellular Histone Acetylation but Not Transcription and Cell Viability

PubMed Central

Lauffer, Benjamin E. L.; Mintzer, Robert; Fong, Rina; Mukund, Susmith; Tam, Christine; Zilberleyb, Inna; Flicke, Birgit; Ritscher, Allegra; Fedorowicz, Grazyna; Vallero, Roxanne; Ortwine, Daniel F.; Gunzner, Janet; Modrusan, Zora; Neumann, Lars; Koth, Christopher M.; Lupardus, Patrick J.; Kaminker, Joshua S.; Heise, Christopher E.; Steiner, Pascal

2013-01-01

Histone deacetylases (HDACs) are critical in the control of gene expression, and dysregulation of their activity has been implicated in a broad range of diseases, including cancer, cardiovascular, and neurological diseases. HDAC inhibitors (HDACi) employing different zinc chelating functionalities such as hydroxamic acids and benzamides have shown promising results in cancer therapy. Although it has also been suggested that HDACi with increased isozyme selectivity and potency may broaden their clinical utility and minimize side effects, the translation of this idea to the clinic remains to be investigated. Moreover, a detailed understanding of how HDACi with different pharmacological properties affect biological functions in vitro and in vivo is still missing. Here, we show that a panel of benzamide-containing HDACi are slow tight-binding inhibitors with long residence times unlike the hydroxamate-containing HDACi vorinostat and trichostatin-A. Characterization of changes in H2BK5 and H4K14 acetylation following HDACi treatment in the neuroblastoma cell line SH-SY5Y revealed that the timing and magnitude of histone acetylation mirrored both the association and dissociation kinetic rates of the inhibitors. In contrast, cell viability and microarray gene expression analysis indicated that cell death induction and changes in transcriptional regulation do not correlate with the dissociation kinetic rates of the HDACi. Therefore, our study suggests that determining how the selective and kinetic inhibition properties of HDACi affect cell function will help to evaluate their therapeutic utility. PMID:23897821

Kinetic and Thermodynamic Rationale for SAHA Being a Preferential Human HDAC8 Inhibitor as Compared to the Structurally Similar Ligand, TSA

PubMed Central

Singh, Raushan K.; Lall, Naveena; Leedahl, Travis S.; McGillivray, Abigail; Mandal, Tanmay; Haldar, Manas; Mallik, Sanku; Cook, Gregory; Srivastava, D.K.

2013-01-01

Of the different hydroxamate-based histone deacetylase (HDAC) inhibitors, Suberoylanilide hydroxamic acid (SAHA) has been approved by the FDA for treatment of T-cell lymphoma. Interestingly, a structurally similar inhibitor, Trichostatin A (TSA), which has a higher in vitro inhibitory-potency against HDAC8, reportedly shows a poor efficacy in clinical settings. In order to gain the molecular insight into the above discriminatory feature, we performed transient kinetic and isothermal titration calorimetric studies for the interaction of SAHA and TSA to the recombinant form of human HDAC8. The transient kinetic data revealed that the binding of both the inhibitors to the enzyme showed the biphasic profiles, which represented an initial encounter of enzyme with the inhibitor followed by the isomerization of the transient enzyme-inhibitor complexes. The temperature-dependent transient kinetic studies with the above inhibitors revealed that the bimolecular process is primarily dominated by favorable enthalpic changes, as opposed to the isomerization step; which is solely contributed by entropic changes. The standard binding-enthalpy (ΔH0) of SAHA, deduced from the transient kinetic as well as the isothermal titration calorimetric experiments, was 2–3 kcal/mol higher as compared to TSA. The experimental data presented herein suggests that SAHA serves as a preferential (target-specific/selective) HDAC8 inhibitor as compared to TSA. Arguments are presented that the detailed kinetic and thermodynamic studies may guide in the rational design of HDAC inhibitors as therapeutic agents. PMID:24079912

Histone deacetylase (HDAC) inhibitor kinetic rate constants correlate with cellular histone acetylation but not transcription and cell viability.

PubMed

Lauffer, Benjamin E L; Mintzer, Robert; Fong, Rina; Mukund, Susmith; Tam, Christine; Zilberleyb, Inna; Flicke, Birgit; Ritscher, Allegra; Fedorowicz, Grazyna; Vallero, Roxanne; Ortwine, Daniel F; Gunzner, Janet; Modrusan, Zora; Neumann, Lars; Koth, Christopher M; Lupardus, Patrick J; Kaminker, Joshua S; Heise, Christopher E; Steiner, Pascal

2013-09-13

Histone deacetylases (HDACs) are critical in the control of gene expression, and dysregulation of their activity has been implicated in a broad range of diseases, including cancer, cardiovascular, and neurological diseases. HDAC inhibitors (HDACi) employing different zinc chelating functionalities such as hydroxamic acids and benzamides have shown promising results in cancer therapy. Although it has also been suggested that HDACi with increased isozyme selectivity and potency may broaden their clinical utility and minimize side effects, the translation of this idea to the clinic remains to be investigated. Moreover, a detailed understanding of how HDACi with different pharmacological properties affect biological functions in vitro and in vivo is still missing. Here, we show that a panel of benzamide-containing HDACi are slow tight-binding inhibitors with long residence times unlike the hydroxamate-containing HDACi vorinostat and trichostatin-A. Characterization of changes in H2BK5 and H4K14 acetylation following HDACi treatment in the neuroblastoma cell line SH-SY5Y revealed that the timing and magnitude of histone acetylation mirrored both the association and dissociation kinetic rates of the inhibitors. In contrast, cell viability and microarray gene expression analysis indicated that cell death induction and changes in transcriptional regulation do not correlate with the dissociation kinetic rates of the HDACi. Therefore, our study suggests that determining how the selective and kinetic inhibition properties of HDACi affect cell function will help to evaluate their therapeutic utility.

Enhanced suppression of tumor growth by concomitant treatment of human lung cancer cells with suberoylanilide hydroxamic acid and arsenic trioxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chien, Chia-Wen; Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 11490, Taiwan; Yao, Ju-Hsien

2011-11-15

The efficacy of arsenic trioxide (ATO) against acute promyelocytic leukemia (APL) and relapsed APL has been well documented. ATO may cause DNA damage by generating reactive oxygen intermediates. Suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, modulates gene and protein expression via histone-dependent or -independent pathways that may result in chromatin decondensation, cell cycle arrest, differentiation, and apoptosis. We investigated whether ATO and SAHA act synergistically to enhance the death of cancer cells. Our current findings showed that combined treatment with ATO and SAHA resulted in enhanced suppression of non-small-cell lung carcinoma in vitro in H1299 cells and in vivomore » in a xenograft mouse model. Flow cytometric analysis of annexin V+ cells showed that apoptotic cell death was significantly enhanced after combined treatment with ATO and SAHA. At the doses used, ATO did not interfere with cell cycle progression, but SAHA induced p21 expression and led to G1 arrest. A Comet assay demonstrated that ATO, but not SAHA, induced DNA strand breaks in H1299 cells; however, co-treatment with SAHA significantly increased ATO-induced DNA damage. Moreover, SAHA enhanced acetylation of histone H3 and sensitized genomic DNA to DNase I digestion. Our results suggest that SAHA may cause chromatin relaxation and increase cellular susceptibility to ATO-induced DNA damage. Combined administration of SAHA and ATO may be an effective approach to the treatment of lung cancer. -- Highlights: Black-Right-Pointing-Pointer ATO and SAHA are therapeutic agents with different action modes. Black-Right-Pointing-Pointer Combination of ATO and SAHA synergistically inhibits tumor cell growth. Black-Right-Pointing-Pointer SAHA loosens chromatin structure resulting in increased sensitivity to DNase I. Black-Right-Pointing-Pointer ATO-induced DNA damage and apoptosis are enhanced by co-treatment with SAHA.« less

Combination of suberoylanilide hydroxamic acid with heavy ion therapy shows promising effects in infantile sarcoma cell lines

PubMed Central

2011-01-01

Introduction The pan-HDAC inhibitor (HDACI) suberoylanilide hydroxamic acid (SAHA) has previously shown to be a radio-sensitizer to conventional photon radiotherapy (XRT) in pediatric sarcoma cell lines. Here, we investigate its effect on the response of two sarcoma cell lines and a normal tissue cell line to heavy ion irradiation (HIT). Materials and methods Clonogenic assays after different doses of heavy ions were performed. DNA damage and repair were evaluated by measuring γH2AX via flow-cytometry. Apoptosis and cell cycle analysis were also measured via flow cytometry. Protein expression of repair proteins, p53 and p21 were measured using immunoblot analysis. Changes of nuclear architecture after treatment with SAHA and HIT were observed in one of the sarcoma cell lines via light microscopy after staining towards chromatin and γH2AX. Results Corresponding with previously reported photon data, SAHA lead to an increase of sensitivity to heavy ions along with an increase of DSB and apoptosis in the two sarcoma cell lines. In contrast, in the osteoblast cell line (hFOB 1.19), the combination of SAHA and HIT showed a significant radio-protective effect. Laser scanning microscopy revealed no significant morphologic changes after HIT compared to the combined treatment with SAHA. Immunoblot analysis revealed no significant up or down regulation of p53. However, p21 was significantly increased by SAHA and combination treatment as compared to HIT only in the two sarcoma cell lines - again in contrast to the osteoblast cell line. Changes in the repair kinetics of DSB p53-independent apoptosis with p21 involvement may be part of the underlying mechanisms for radio-sensitization by SAHA. Conclusion Our in vitro data suggest an increase of the therapeutic ratio by the combination of SAHA with HIT in infantile sarcoma cell lines. PMID:21933400

Effects of treatment with suppressive combination antiretroviral drug therapy and the histone deacetylase inhibitor suberoylanilide hydroxamic acid; (SAHA) on SIV-infected Chinese rhesus macaques.

PubMed

Ling, Binhua; Piatak, Michael; Rogers, Linda; Johnson, Ann-Marie; Russell-Lodrigue, Kasi; Hazuda, Daria J; Lifson, Jeffrey D; Veazey, Ronald S

2014-01-01

Viral reservoirs-persistent residual virus despite combination antiretroviral therapy (cART)-remain an obstacle to cure of HIV-1 infection. Difficulty studying reservoirs in patients underscores the need for animal models that mimics HIV infected humans on cART. We studied SIV-infected Chinese-origin rhesus macaques (Ch-RM) treated with intensive combination antiretroviral therapy (cART) and 3 weeks of treatment with the histone deacetyalse inhibitor, suberoylanilide hydroxamic acid (SAHA). SIVmac251 infected Ch-RM received reverse transcriptase inhibitors PMPA and FTC and integrase inhibitor L-870812 beginning 7 weeks post infection. Integrase inhibitor L-900564 and boosted protease inhibitor treatment with Darunavir and Ritonavir were added later. cART was continued for 45 weeks, with daily SAHA administered for the last 3 weeks, followed by euthanasia/necropsy. Plasma viral RNA and cell/tissue-associated SIV gag RNA and DNA were quantified by qRT-PCR/qPCR, with flow cytometry monitoring changes in immune cell populations. Upon cART initiation, plasma viremia declined, remaining <30 SIV RNA copy Eq/ml during cART, with occasional blips. Decreased viral replication was associated with decreased immune activation and partial restoration of intestinal CD4+ T cells. SAHA was well tolerated but did not result in demonstrable treatment-associated changes in plasma or cell associated viral parameters. The ability to achieve and sustain virological suppression makes cART-suppressed, SIV-infected Ch-RM a potentially useful model to evaluate interventions targeting residual virus. However, despite intensive cART over one year, persistent viral DNA and RNA remained in tissues of all three animals. While well tolerated, three weeks of SAHA treatment did not demonstrably impact viral RNA levels in plasma or tissues; perhaps reflecting dosing, sampling and assay limitations.

4-(1-Ethyl-4-anisyl-imidazol-5-yl)-N-hydroxycinnamide – A new pleiotropic HDAC inhibitor targeting cancer cell signalling and cytoskeletal organisation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahal, Katharina, E-mail: katharina.mahal@uni-bayreuth.de; Kahlen, Philip, E-mail: philip.kahlen@uni-bayreuth.de; Biersack, Bernhard, E-mail: bernhard.biersack@yahoo.com

2015-08-15

Histone deacetylases (HDAC) which play a crucial role in cancer cell proliferation are promising drug targets. However, HDAC inhibitors (HDACi) modelled on natural hydroxamic acids such as trichostatin A frequently lead to resistance or even an increased agressiveness of tumours. As a workaround we developed 4-(1-ethyl-4-anisyl-imidazol-5-yl)-N-hydroxycinnamide (etacrox), a hydroxamic acid that combines HDAC inhibition with synergistic effects of the 4,5-diarylimidazole residue. Etacrox proved highly cytotoxic against a panel of metastatic and resistant cancer cell lines while showing greater specificity for cancer over non-malignant cells when compared to the approved HDACi vorinostat. Like the latter, etacrox and the closely related imidazolesmore » bimacroxam and animacroxam acted as pan-HDACi yet showed some specificity for HDAC6. Akt signalling and interference with nuclear beta-catenin localisation were elicited by etacrox at lower concentrations when compared to vorinostat. Moreover, etacrox disrupted the microtubule and focal adhesion dynamics of cancer cells and inhibited the proteolytic activity of prometastatic and proangiogenic matrix metalloproteinases. As a consequence, etacrox acted strongly antimigratory and antiinvasive against various cancer cell lines in three-dimensional transwell invasion assays and also antiangiogenic in vivo with respect to blood vessel formation in the chorioallantoic membrane assay. These pleiotropic effects and its water-solubility and tolerance by mice render etacrox a promising new HDACi candidate. - Graphical abstract: A novel histone deacetylase inhibitor with pleiotropic anticancer effects. - Highlights: • Etacrox is a new HDACi with cytotoxic, antiangiogenic and antiinvasive activity. • Etacrox causes aberrant cancer cell signalling and cytoskeletal reorganisation. • Pro-metastatic and angiogenic matrix metalloproteinases are inhibited by etacrox. • Etacrox impairs blood vessel maturation in vivo and cancer cell invasion in vitro. • Etacrox is tolerated well by mice in doses as high as 150 mg/kg.« less

Quantitative Analysis of Global Proteome and Lysine Acetylome Reveal the Differential Impacts of VPA and SAHA on HL60 Cells.

PubMed

Zhu, Xiaoyu; Liu, Xin; Cheng, Zhongyi; Zhu, Jun; Xu, Lei; Wang, Fengsong; Qi, Wulin; Yan, Jiawei; Liu, Ning; Sun, Zimin; Liu, Huilan; Peng, Xiaojun; Hao, Yingchan; Zheng, Nan; Wu, Quan

2016-01-29

Valproic acid (VPA) and suberoylanilide hydroxamic acid (SAHA) are both HDAC inhibitors (HDACi). Previous studies indicated that both inhibitors show therapeutic effects on acute myeloid leukaemia (AML), while the differential impacts of the two different HDACi on AML treatment still remains elusive. In this study, using 3-plex SILAC based quantitative proteomics technique, anti-acetyllysine antibody based affinity enrichment, high resolution LC-MS/MS and intensive bioinformatic analysis, the quantitative proteome and acetylome in SAHA and VPA treated AML HL60 cells were extensively studied. In total, 5,775 proteins and 1,124 lysine acetylation sites were successfully obtained in response to VAP and SAHA treatment. It is found that VPA and SAHA treatment differently induced proteome and acetylome profiling in AML HL60 cells. This study revealed the differential impacts of VPA and SAHA on proteome/acetylome in AML cells, deepening our understanding of HDAC inhibitor mediated AML therapeutics.

Antiproliferative effects of TSA, PXD‑101 and MS‑275 in A2780 and MCF7 cells: Acetylated histone H4 and acetylated tubulin as markers for HDACi potency and selectivity.

PubMed

Androutsopoulos, Vasilis P; Spandidos, Demetrios A

2017-12-01

Inhibition of histone deacetylase enzymes (HDACs) has been well documented as an attractive target for the development of chemotherapeutic drugs. The present study investigated the effects of two prototype hydroxamic acid HDAC inhibitors, namely Trichostatin A (TSA) and Belinostat (PXD‑101) and the benzamide Entinostat (MS‑275) in A2780 ovarian carcinoma and MCF7 breast adenocarcinoma cells. The three HDACi inhibited the proliferation of A2780 and MCF7 cells at comparable levels, below the µM range. Enzyme inhibition assays in a cell‑free system showed that TSA was the most potent inhibitor of total HDAC enzyme activity followed by PXD‑101 and MS‑275. Incubation of A2780 and MCF7 cells with the hydroxamates TSA and PXD‑101 for 24 h resulted in a dramatic increase of acetylated tubulin induction (up to 30‑fold for TSA). In contrast to acetylated tubulin, western blot analysis and flow cytometry indicated that the induction of acetylated histone H4 was considerably smaller. The benzamide MS‑275 exhibited nearly a 2‑fold induction of acetylated histone H4 and an even smaller induction of acetylated tubulin in A2780 and MCF7 cells. Taken together, these data suggest that although the three HDACi were equipotent in inhibiting proliferation of MCF7 and A2780 cells, only the benzamide MS‑275 did not induce acetylated tubulin expression, a marker of class IIb HDACs.

Development of Iron-Chelating Poly(ethylene terephthalate) Packaging for Inhibiting Lipid Oxidation in Oil-in-Water Emulsions.

PubMed

Johnson, David R; Tian, Fang; Roman, Maxine J; Decker, Eric A; Goddard, Julie M

2015-05-27

Foods such as bulk oils, salad dressings, and nutritionally fortified beverages that are susceptible to oxidative degradation are often packaged in poly(ethylene terephthalate) (PET) bottles with metal chelators added to the food to maintain product quality. In the present work, a metal-chelating active packaging material is designed and characterized, in which poly(hydroxamic acid) (PHA) metal-chelating moieties were grafted from the surface of PET. Biomimetic PHA groups were grafted in a two-step UV-initiated process without the use of a photoinitiator. Surface characterization of the films by attenuated total reflective Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM) suggested successful grafting and conversion of poly(hydroxyethyl acrylate) (PHEA) to PHA chelating moieties from the surface of PET. Colorimetric (ferrozine) and inductively coupled plasma mass spectroscopy (ICP-MS) assays demonstrated the ability of PET-g-PHA to chelate iron in a low-pH (3.0) environment containing a competitive metal chelator (citric acid). Lipid oxidation studies demonstrated the antioxidant activity of PET-g-PHA films in inhibiting iron-promoted oxidation in an acidified oil-in-water (O/W) emulsion model system (pH 3.0). Particle size and ζ-potential analysis indicated that the addition of PET-g-PHA films did not affect the physical stability of the emulsion system. This work suggests that biomimetic chelating moieties can be grafted from PET and effectively inhibit iron-promoted degradation reactions, enabling removal of metal-chelating additives from product formulations.

Probing the Carbonyl Functionality of a Petroleum Resin and Asphaltene through Oximation and Schiff Base Formation in Conjunction with N-15 NMR

PubMed Central

Thorn, Kevin A.; Cox, Larry G.

2015-01-01

Despite recent advances in spectroscopic techniques, there is uncertainty regarding the nature of the carbonyl groups in the asphaltene and resin fractions of crude oil, information necessary for an understanding of the physical properties and environmental fate of these materials. Carbonyl and hydroxyl group functionalities are not observed in natural abundance 13C nuclear magnetic resonance (NMR) spectra of asphaltenes and resins and therefore require spin labeling techniques for detection. In this study, the carbonyl functionalities of the resin and asphaltene fractions from a light aliphatic crude oil that is the source of groundwater contamination at the long term USGS study site near Bemidji, Minnesota, have been examined through reaction with 15N-labeled hydroxylamine and aniline in conjunction with analysis by solid and liquid state 15N NMR. Ketone groups were revealed through 15N NMR detection of their oxime and Schiff base derivatives, and esters through their hydroxamic acid derivatives. Anilinohydroquinone adducts provided evidence for quinones. Some possible configurations of the ketone groups in the resin and asphaltene fractions can be inferred from a consideration of the likely reactions that lead to heterocyclic condensation products with aniline and to the Beckmann reaction products from the initially formed oximes. These include aromatic ketones and ketones adjacent to quaternary carbon centers, β-hydroxyketones, β-diketones, and β-ketoesters. In a solid state cross polarization/magic angle spinning (CP/MAS) 15N NMR spectrum recorded on the underivatized asphaltene as a control, carbazole and pyrrole-like nitrogens were the major naturally abundant nitrogens detected. PMID:26556054

Analysis of hydroxamate siderophores in soil solution using liquid chromatography with mass spectrometry and tandem mass spectrometry with on-line sample preconcentration.

PubMed

Olofsson, Madelen A; Bylund, Dan

2015-10-01

A liquid chromatography with electrospray ionization mass spectrometry method was developed to quantitatively and qualitatively analyze 13 hydroxamate siderophores (ferrichrome, ferrirubin, ferrirhodin, ferrichrysin, ferricrocin, ferrioxamine B, D1 , E and G, neocoprogen I and II, coprogen and triacetylfusarinine C). Samples were preconcentrated on-line by a switch-valve setup prior to analyte separation on a Kinetex C18 column. Gradient elution was performed using a mixture of an ammonium formate buffer and acetonitrile. Total analysis time including column conditioning was 20.5 min. Analytes were fragmented by applying collision-induced dissociation, enabling structural identification by tandem mass spectrometry. Limit of detection values for the selected ion monitoring method ranged from 71 pM to 1.5 nM with corresponding values of two to nine times higher for the multiple reaction monitoring method. The liquid chromatography with mass spectrometry method resulted in a robust and sensitive quantification of hydroxamate siderophores as indicated by retention time stability, linearity, sensitivity, precision and recovery. The analytical error of the methods, assessed through random-order, duplicate analysis of soil samples extracted with a mixture of 10 mM phosphate buffer and methanol, appears negligible in relation to between-sample variations. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An additional role for the Brønsted acid-base catalysts of mandelate racemase in transition state stabilization.

PubMed

Nagar, Mitesh; Bearne, Stephen L

2015-11-10

Mandelate racemase (MR) catalyzes the interconversion of the enantiomers of mandelate and serves as a paradigm for understanding the enzyme-catalyzed abstraction of an α-proton from a carbon acid substrate with a high pKa. The enzyme utilizes a two-base mechanism with Lys 166 and His 297 acting as Brønsted acid and base catalysts, respectively, in the R → S reaction direction. In the S → R reaction direction, their roles are reversed. Using isothermal titration calorimetry (ITC), MR is shown to bind the intermediate/transition state (TS) analogue inhibitor benzohydroxamate (BzH) in an entropy-driven process with a value of ΔCp equal to -358 ± 3 cal mol(-1) K(-1), consistent with an increased number of hydrophobic interactions. However, MR binds BzH with an affinity that is ∼2 orders of magnitude greater than that predicted solely on the basis of hydrophobic interactions [St. Maurice, M., and Bearne, S. L. (2004) Biochemistry 43, 2524], suggesting that additional specific interactions contribute to binding. To test the hypothesis that cation-π/NH-π interactions between the side chains of Lys 166 and His 297 and the aromatic ring and/or the hydroxamate/hydroximate moiety of BzH contribute to the binding of BzH, site-directed mutagenesis was used to generate the MR variants K166M, K166C, H297N, and K166M/H297N and their binding affinity for various ligands determined using ITC. Comparison of the binding affinities of these MR variants with the intermediate/TS analogues BzH and cyclohexanecarbohydroxamate revealed that cation-π/NH-π interactions between His 297 and the hydroxamate/hydroximate moiety and the phenyl ring of BzH contribute approximately 0.26 and 0.91 kcal/mol to binding, respectively, while interactions with Lys 166 contribute approximately 1.74 and 1.74 kcal/mol, respectively. Similarly, comparison of the binding affinities of these mutants with substrate analogues revealed that Lys 166 contributes >2.93 kcal/mol to the binding of (R)-atrolactate, and His 297 contributes 2.46 kcal/mol to the binding of (S)-atrolactate. These results are consistent with Lys 166 and His 297 playing dual roles in catalysis: they act as Brønsted acid-base catalysts, and they stabilize both the enolate moiety and phenyl ring of the altered substrate in the TS.

Role of growth media and chemical enhancers in secondary metabolites production from Aspergillus carbonarius (NRL-369) and their pharmaceutical potentials.

PubMed

Khan, Abid Ali; Bacha, Nafess; Ahmad, Bashir; Cox, R J; Bakht, Jehan

2016-07-01

The present study investigates the effect of different growth media and chemical enhancer on silent genes in Aspergillus carbonarius (NRL-369) for secondary metabolites production and its in vitro biological activities. Results revealed that Aspergillus carbonarius (NRL-369) grown in Czapeak yeast extract broth medium produced more metabolites compared with other media. Chemical epigenetic modifiers (suberoyl-anilide hydroxamic acid (SAHA) and 5-azacytidine (5-AZA) at concentration of 15mM were effective for the expression of silent genes resulting in increased secondary metabolites production. Secondary metabolites extracted in ethyl acetate and fractionized in n-Hexane showed variable degree of growth inhibitions of the tested microorganisms. Similarly, these samples were also active against brine shrimps and Lemna.

Electron injection dynamics in high-potential porphyrin photoanodes.

PubMed

Milot, Rebecca L; Schmuttenmaer, Charles A

2015-05-19

There is a growing need to utilize carbon neutral energy sources, and it is well known that solar energy can easily satisfy all of humanity's requirements. In order to make solar energy a viable alternative to fossil fuels, the problem of intermittency must be solved. Batteries and supercapacitors are an area of active research, but they currently have relatively low energy-to-mass storage capacity. An alternative and very promising possibility is to store energy in chemical bonds, or make a solar fuel. The process of making solar fuel is not new, since photosynthesis has been occurring on earth for about 3 billion years. In order to produce any fuel, protons and electrons must be harvested from a species in its oxidized form. Photosynthesis uses the only viable source of electrons and protons on the scale needed for global energy demands: water. Because artificial photosynthesis is a lofty goal, water oxidation, which is a crucial step in the process, has been the initial focus. This Account provides an overview of how terahertz spectroscopy is used to study electron injection, highlights trends from previously published reports, and concludes with a future outlook. It begins by exploring similarities and differences between dye-sensitized solar cells (DSSCs) for producing electricity and a putative device for splitting water and producing a solar fuel. It then identifies two important problems encountered when adapting DSSC technology to water oxidation-improper energy matching between sensitizer energy levels with the potential for water oxidation and the instability of common anchoring groups in water-and discusses steps to address them. Emphasis is placed on electron injection from sensitizers to metal oxides because this process is the initial step in charge transport. Both the rate and efficiency of electron injection are analyzed on a sub-picosecond time scale using time-resolved terahertz spectroscopy (TRTS). Bio-inspired pentafluorophenyl porphyrins are promising sensitizers because their high reduction potentials are compatible with the energy requirements of water oxidation. TRTS of free-base and metalated pentafluorophenyl porphyrins reveal inefficient electron injection into TiO2 nanoparticles but more efficient electron injection into SnO2 nanoparticles. With SnO2, injection time scales depend strongly on the identity of the central substituent and are affected by competition with excited-state deactivation processes. Heavy or paramagnetic metal ions increase the electron injection time scale by roughly one order of magnitude relative to free-base or Zn(2+) porphyrins due to the possibility of electron injection from longer-lived, lower-lying triplet states. Furthermore, electron injection efficiency loosely correlates with DSSC performance. The carboxylate anchoring group is commonly used to bind DSSC sensitizers to metal oxide surfaces but typically is not stable under the aqueous and oxidative conditions required for water oxidation. Electron injection efficiency of several water-stable alternatives, including phosphonic acid, hydroxamic acid, acetylacetone, and boronic acid, were evaluated using TRTS, and hydroxamate was found to perform as well as the carboxylate. The next challenge is incorporating a water oxidation catalyst into the design. An early example, in which an Ir-based precatalyst is cosensitized with a fluorinated porphyrin, reveals decreased electron injection efficiency despite an increase in photocurrent. Future research will seek to better understand and address these difficulties.

Chemical intervention in bacterial lignin degradation pathways: Development of selective inhibitors for intradiol and extradiol catechol dioxygenases.

PubMed

Sainsbury, Paul D; Mineyeva, Yelena; Mycroft, Zoe; Bugg, Timothy D H

2015-06-01

Bacterial lignin degradation could be used to generate aromatic chemicals from the renewable resource lignin, provided that the breakdown pathways can be manipulated. In this study, selective inhibitors of enzymatic steps in bacterial degradation pathways were developed and tested for their effects upon lignin degradation. Screening of a collection of hydroxamic acid metallo-oxygenase inhibitors against two catechol dioxygenase enzymes, protocatechuate 3,4-dioxygenase (3,4-PCD) and 2,3-dihydroxyphenylpropionate 1,2-dioxygenase (MhpB), resulted in the identification of selective inhibitors D13 for 3,4-PCD (IC50 15μM) and D3 for MhpB (IC50 110μM). Application of D13 to Rhodococcus jostii RHA1 in minimal media containing ferulic acid led to the appearance of metabolic precursor protocatechuic acid at low concentration. Application of 1mM disulfiram, an inhibitor of mammalian aldehyde dehydrogenase, to R. jostii RHA1, gave rise to 4-carboxymuconolactone on the β-ketoadipate pathway, whereas in Pseudomonas fluorescens Pf-5 disulfiram treatment gave rise to a metabolite found to be glycine betaine aldehyde. Copyright © 2015 Elsevier Inc. All rights reserved.

Histone deacetylase inhibitors induce growth arrest and differentiation in uveal melanoma

PubMed Central

Landreville, Solange; Agapova, Olga A.; Matatall, Katie A.; Kneass, Zachary T.; Onken, Michael D.; Lee, Ryan S.; Bowcock, Anne M.; Harbour, J. William

2011-01-01

Purpose Metastasis is responsible for the death of most cancer patients, yet few therapeutic agents are available which specifically target the molecular events that lead to metastasis. We recently showed that inactivating mutations in the tumor suppressor gene BAP1 are closely associated with loss of melanocytic differentiation in uveal melanoma and metastasis (UM). The purpose of this study was to identify therapeutic agents that reverse the phenotypic effects of BAP1 loss in UM. Experimental Design In silico screens were performed to identify therapeutic compounds predicted to differentiate UM cells using Gene Set Enrichment Analysis and Connectivity Map databases. Valproic acid, trichostatin A, LBH-589 and suberoylanilide hydroxamic acid were evaluated for their effects on UM cells using morphologic evaluation, MTS viability assays, BrdU incorporation, flow cytometry, clonogenic assays, gene expression profiling, histone acetylation and ubiquitination assays, and a murine xenograft tumorigenicity model. Results HDAC inhibitors induced morphologic differentiation, cell cycle exit, and a shift to a differentiated, melanocytic gene expression profile in cultured UM cells. Valproic acid inhibited the growth of UM tumors in vivo. Conclusions These findings suggest that HDAC inhibitors may have therapeutic potential for inducing differentiation and prolonged dormancy of micrometastatic disease in UM. PMID:22038994

Application of INEPT nitrogen-15 and silicon-29 nuclear magnetic resonance spectrometry to derivatized fulvic acids

USGS Publications Warehouse

Thorn, K.A.; Folan, D.W.; Arterburn, J.B.; Mikita, M.A.; MacCarthy, P.

1989-01-01

Use of the INEPT experiment has been examined in two derivatization studies of the Suwannee River fulvic acid. In the first study, the fulvic acid was derivatized with 15N enriched hydroxylamine. The quantitative 15N NMR spectrum, acquired with a 45° pulse angle, 2.0 second pulse delay and inverse gated decoupling, showed that oximes (390-340 ppm) were the major derivatives, followed by nitriles (270-240 ppm), hydroxamic acids (170-160 ppm), secondary amides (150-115 ppm), and lactams (115-90 ppm). The INEPT 15N NMR spectrum was acquired using refocussing delays and polarization transfer times optimized for signal enhancement of singly protonated nitrogens. INEPT greatly enhanced the amide and lactam resonances, and showed that resonances downfield of 180 ppm in the quantitative spectrum represented nonprotonated nitrogens. In the second study, the fulvic acid was first methylated with diazomethane and then silylated with hexamethyldisilazane. The 29Si NMR spectra exhibited two major peaks, from approximately 33 to 22 ppm, representing silyl esters of carboxylic acids, and from 22 to 13 ppm, representing silyl ethers of alcohols and phenols. The INEPT 29Si NMR spectrum was virtually identical to the quantitative 29Si spectrum, acquired with a 90° pulse angle, 5.0 second pulse delay, inverse gated decoupling, and relaxation reagent. INEPT therefore can be used for quantitative analysis of trimethylsilyl derivatives of the fulvic acid, saving spectrometer time and eliminating the need for relaxation reagents.

Suberoylanilide hydroxamic acid (SAHA; vorinostat) causes bone loss by inhibiting immature osteoblasts.

PubMed

McGee-Lawrence, Meghan E; McCleary-Wheeler, Angela L; Secreto, Frank J; Razidlo, David F; Zhang, Minzhi; Stensgard, Bridget A; Li, Xiaodong; Stein, Gary S; Lian, Jane B; Westendorf, Jennifer J

2011-05-01

Histone deacetylase (Hdac) inhibitors are used clinically to treat cancer and epilepsy. Although Hdac inhibition accelerates osteoblast maturation and suppresses osteoclast maturation in vitro, the effects of Hdac inhibitors on the skeleton are not understood. The purpose of this study was to determine how the pan-Hdac inhibitor, suberoylanilide hydroxamic acid (SAHA; a.k.a. vorinostat or Zolinza(TM)) affects bone mass and remodeling in vivo. Male C57BL/6J mice received daily SAHA (100mg/kg) or vehicle injections for 3 to 4weeks. SAHA decreased trabecular bone volume fraction and trabecular number in the distal femur. Cortical bone at the femoral midshaft was not affected. SAHA reduced serum levels of P1NP, a bone formation marker, and also suppressed tibial mRNA levels of type I collagen, osteocalcin and osteopontin, but did not alter Runx2 or osterix transcripts. SAHA decreased histological measures of osteoblast number but interestingly increased indices of osteoblast activity including mineral apposition rate and bone formation rate. Neither serum (TRAcP 5b) nor histological markers of bone resorption were affected by SAHA. P1NP levels returned to baseline in animals which were allowed to recover for 4weeks after 4weeks of daily SAHA injections, but bone density remained low. In vitro, SAHA suppressed osteogenic colony formation, decreased osteoblastic gene expression, induced cell cycle arrest, and caused DNA damage in bone marrow-derived adherent cells. Collectively, these data demonstrate that bone loss following treatment with SAHA is primarily due to a reduction in osteoblast number. Moreover, these decreases in osteoblast number can be attributed to the deleterious effects of SAHA on immature osteoblasts, even while mature osteoblasts are resistant to the harmful effects and demonstrate increased activity in vivo, indicating that the response of osteoblasts to SAHA is dependent upon their differentiation state. These studies suggest that clinical use of SAHA and other Hdac inhibitors to treat cancer, epilepsy or other conditions may potentially compromise skeletal structure and function. Copyright © 2011 Elsevier Inc. All rights reserved.

Histone deacetylase inhibitors containing a benzamide functional group and a pyridyl cap are preferentially effective human immunodeficiency virus-1 latency-reversing agents in primary resting CD4+ T cells

PubMed Central

Gélinas, Céline

2017-01-01

Antiretroviral therapy (ART) can control human immunodeficiency virus-1 (HIV-1) replication in infected individuals. Unfortunately, patients remain persistently infected owing to the establishment of latent infection requiring that ART be maintained indefinitely. One strategy being pursued involves the development of latency-reversing agents (LRAs) to eliminate the latent arm of the infection. One class of molecules that has been tested for LRA activity is the epigenetic modulating compounds histone deacetylases inhibitors (HDACis). Previously, initial screening of these molecules typically commenced using established cell models of viral latency, and although certain drugs such as the HDACi suberoylanilide hydroxamic acid demonstrated strong activity in these models, it did not translate to comparable activity with patient samples. Here we developed a primary cell model of viral latency using primary resting CD4+ T cells infected with Vpx-complemented HIV-1 and found that the activation profile using previously described LRAs mimicked that obtained with patient samples. This primary cell model was used to evaluate 94 epigenetic compounds. Not surprisingly, HDACis were found to be the strongest activators. However, within the HDACi class, the most active LRAs with the least pronounced toxicity contained a benzamide functional moiety with a pyridyl cap group, as exemplified by the HDACi chidamide. The results indicate that HDACis with a benzamide moiety and pyridyl cap group should be considered for further drug development in the pursuit of a successful viral clearance strategy. PMID:28113052

Probing the carbonyl functionality of a petroleum resin and asphaltene through oximation and schiff base formation in conjunction with N-15 NMR

USGS Publications Warehouse

Thorn, Kevin A.; Cox, Larry G.

2015-01-01

Despite recent advances in spectroscopic techniques, there is uncertainty regarding the nature of the carbonyl groups in the asphaltene and resin fractions of crude oil, information necessary for an understanding of the physical properties and environmental fate of these materials. Carbonyl and hydroxyl group functionalities are not observed in natural abundance 13C nuclear magnetic resonance (NMR) spectra of asphaltenes and resins and therefore require spin labeling techniques for detection. In this study, the carbonyl functionalities of the resin and asphaltene fractions from a light aliphatic crude oil that is the source of groundwater contamination at the long term USGS study site near Bemidji, Minnesota, have been examined through reaction with 15N-labeled hydroxylamine and aniline in conjunction with analysis by solid and liquid state 15N NMR. Ketone groups were revealed through 15N NMR detection of their oxime and Schiff base derivatives, and esters through their hydroxamic acid derivatives. Anilinohydroquinone adducts provided evidence for quinones. Some possible configurations of the ketone groups in the resin and asphaltene fractions can be inferred from a consideration of the likely reactions that lead to heterocyclic condensation products with aniline and to the Beckmann reaction products from the initially formed oximes. These include aromatic ketones and ketones adjacent to quaternary carbon centers, β-hydroxyketones, β-diketones, and β-ketoesters. In a solid state cross polarization/magic angle spinning (CP/MAS) 15N NMR spectrum recorded on the underivatized asphaltene as a control, carbazole and pyrrole-like nitrogens were the major naturally abundant nitrogens detected.

Evaluation of 6-([18F] fluoroacetamido)-1-hexanoic-anilide (18F-FAHA) as imaging probe in tumor xenograft mice model

NASA Astrophysics Data System (ADS)

Li, Fiona; Cho, Sung Ju; Yu, Lihai; Hudson, Robert H. E.; Luyt, Leonard G.; Pin, Christopher L.; Kovacs, Michael S.; Koropatnick, James; Lee, Ting-Yim

2016-03-01

Alteration in genetic expression is as important as gene mutation in cancer development and proliferation. Epigenetic changes affect gene expression without altering the DNA sequence. Histone deacetylase (HDAC), an enzyme facilitating histone remodelling, can lead to silencing of tumor suppressor genes making HDAC inhibitors viable anticancer drugs against tumors with increased activity of the enzyme. In this study we evaluated 18F-fluroacetamido-1-hexanoicanilide (18F-FAHA), an artificial HDAC substrate, as imaging probe of HDAC activity of human tumor xenografts in immunocompromised host mice. Human breast and melanoma cell lines, MDA-MB-468 and MDA-MB-435 respectively, known to overexpress HDAC activity were xenografted into immunocompromised mice and HDAC activity was imaged using 18F-FAHA. The melanoma group was treated with saline, SAHA (suberoylanilide hydroxamic acid, an approved anticancer HDAC inhibitor) in DMSO, or DMSO as positive control. Tracer kinetic modelling and SUV were used to estimate HDAC activity from dynamic PET data. Both breast tumor and melanoma group showed great variability in binding rate constant (BRC) of 18F-FAHA suggesting highly variable inter- and intra-tumoral HDAC activity. For the SAHA treated melanoma group, HDAC activity, as monitored by BRC of 18F-FAHA, decreased more than the two (positive and negative) control groups but not tumor growth. Our preliminary study showed that noninvasive PET imaging with 18F-FAHA has the potential to identify patients for whom treatment with HDAC inhibitors are appropriate, to assess the effectiveness of that treatment as an early marker of target reduction, and also eliminate the need for invasive tissue biopsy to individualize treatment.

SAHA Suppresses Peritoneal Fibrosis in Mice

PubMed Central

Io, Kumiko; Nishino, Tomoya; Obata, Yoko; Kitamura, Mineaki; Koji, Takehiko; Kohno, Shigeru

2015-01-01

♦ Objective: Long-term peritoneal dialysis causes peritoneal fibrosis in submesothelial areas. However, the mechanism of peritoneal fibrosis is unclear. Epigenetics is the mechanism to induce heritable changes without any changes in DNA sequences. Among epigenetic modifications, histone acetylation leads to the transcriptional activation of genes. Recent studies indicate that histone acetylation is involved in the progression of fibrosis. Therefore, we examined the effect of suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, on the progression of peritoneal fibrosis in mice. ♦ Methods: Peritoneal fibrosis was induced by the injection of chlorhexidine gluconate (CG) into the peritoneal cavity of mice every other day for 3 weeks. SAHA, or a dimethylsulfoxide and saline vehicle, was administered subcutaneously every day from the start of the CG injections for 3 weeks. Morphologic peritoneal changes were assessed by Masson’s trichrome staining, and fibrosis-associated factors were assessed by immunohistochemistry. ♦ Results: In CG-injected mice, a marked thickening of the submesothelial compact zone was observed. In contrast, the administration of SAHA suppressed the progression of submesothelial thickening and type III collagen accumulation in CG-injected mice. The numbers of fibroblast-specific protein-1-positive cells and α-smooth muscle actin α-positive cells were significantly decreased in the CG + SAHA group compared to that of the CG group. The level of histone acetylation was reduced in the peritoneum of the CG group, whereas it was increased in the CG + SAHA group. ♦ Conclusions: Our results indicate that SAHA can suppress peritoneal thickening and fibrosis in mice through up-regulation of histone acetylation. These results suggest that SAHA may have therapeutic potential for treating peritoneal fibrosis. PMID:24584598

Plants Release Precursors of Histone Deacetylase Inhibitors to Suppress Growth of Competitors[OPEN

PubMed Central

Venturelli, Sascha; Belz, Regina G.; Kämper, Andreas; Berger, Alexander; von Horn, Kyra; Wegner, André; Böcker, Alexander; Zabulon, Gérald; Barneche, Fredy; Lauer, Ulrich M.; Bitzer, Michael

2015-01-01

To secure their access to water, light, and nutrients, many plant species have developed allelopathic strategies to suppress competitors. To this end, they release into the rhizosphere phytotoxic substances that inhibit the germination and growth of neighbors. Despite the importance of allelopathy in shaping natural plant communities and for agricultural production, the underlying molecular mechanisms are largely unknown. Here, we report that allelochemicals derived from the common class of cyclic hydroxamic acid root exudates directly affect the chromatin-modifying machinery in Arabidopsis thaliana. These allelochemicals inhibit histone deacetylases both in vitro and in vivo and exert their activity through locus-specific alterations of histone acetylation and associated gene expression. Our multilevel analysis collectively shows how plant-plant interactions interfere with a fundamental cellular process, histone acetylation, by targeting an evolutionarily highly conserved class of enzymes. PMID:26530086

Design, Synthesis, and Properties of a Potent Inhibitor of Pseudomonas aeruginosa Deacetylase LpxC.

PubMed

Piizzi, Grazia; Parker, David T; Peng, Yunshan; Dobler, Markus; Patnaik, Anup; Wattanasin, Som; Liu, Eugene; Lenoir, Francois; Nunez, Jill; Kerrigan, John; McKenney, David; Osborne, Colin; Yu, Donghui; Lanieri, Leanne; Bojkovic, Jade; Dzink-Fox, JoAnn; Lilly, Maria-Dawn; Sprague, Elizabeth R; Lu, Yipin; Wang, Hongming; Ranjitkar, Srijan; Xie, Lili; Wang, Bing; Glick, Meir; Hamann, Lawrence G; Tommasi, Ruben; Yang, Xia; Dean, Charles R

2017-06-22

Over the past several decades, the frequency of antibacterial resistance in hospitals, including multidrug resistance (MDR) and its association with serious infectious diseases, has increased at alarming rates. Pseudomonas aeruginosa is a leading cause of nosocomial infections, and resistance to virtually all approved antibacterial agents is emerging in this pathogen. To address the need for new agents to treat MDR P. aeruginosa, we focused on inhibiting the first committed step in the biosynthesis of lipid A, the deacetylation of uridyldiphospho-3-O-(R-hydroxydecanoyl)-N-acetylglucosamine by the enzyme LpxC. We approached this through the design, synthesis, and biological evaluation of novel hydroxamic acid LpxC inhibitors, exemplified by 1, where cytotoxicity against mammalian cell lines was reduced, solubility and plasma-protein binding were improved while retaining potent anti-pseudomonal activity in vitro and in vivo.

PLGA-PEG Nanoparticles Coated with Anti-CD45RO and Loaded with HDAC Plus Protease Inhibitors Activate Latent HIV and Inhibit Viral Spread

NASA Astrophysics Data System (ADS)

Tang, Xiaolong; Liang, Yong; Liu, Xinkuang; Zhou, Shuping; Liu, Liang; Zhang, Fujina; Xie, Chunmei; Cai, Shuyu; Wei, Jia; Zhu, Yongqiang; Hou, Wei

2015-10-01

Activating HIV-1 proviruses in latent reservoirs combined with inhibiting viral spread might be an effective anti-HIV therapeutic strategy. Active specific delivery of therapeutic drugs into cells harboring latent HIV, without the use of viral vectors, is a critical challenge to this objective. In this study, nanoparticles of poly(lactic-co-glycolic acid)-polyethylene glycol diblock copolymers conjugated with anti-CD45RO antibody and loaded with the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) and/or protease inhibitor nelfinavir (Nel) were tested for activity against latent virus in vitro. Nanoparticles loaded with SAHA, Nel, and SAHA + Nel were characterized in terms of size, surface morphology, zeta potential, entrapment efficiency, drug release, and toxicity to ACH-2 cells. We show that SAHA- and SAHA + Nel-loaded nanoparticles can target latently infected CD4+ T-cells and stimulate virus production. Moreover, nanoparticles loaded with SAHA + NEL were capable of both activating latent virus and inhibiting viral spread. Taken together, these data demonstrate the potential of this novel reagent for targeting and eliminating latent HIV reservoirs.

Differentiation and upregulation of heat shock protein 70 induced by a subset of histone deacetylase inhibitors in mouse and human embryonic stem cells.

PubMed

Park, Jeong-A; Kim, Young-Eun; Seok, Hyun-Jeong; Park, Woo-Youn; Kwon, Hyung-Joo; Lee, Younghee

2011-03-01

Inhibiting histone deacetylase (HDAC) activity modulates the epigenetic status of cells, resulting in an alteration of gene expression and cellular function. Here, we investigated the effects of HDAC inhibitors on mouse embryonic stem (ES) cells. The HDAC inhibitors trichostatin A, suberoylanilide hydroxamic acid, sodium butyrate, and valproic acid induced early differentiation of mouse ES cells and triggered induction of heatshock protein (HSP)70. In contrast, class III HDAC inhibitors failed to induce differentiation or HSP70 expression. Transcriptional upregulation of HSP70 was confirmed by mRNA expression analysis, an inhibitor study, and chromatin immunoprecipitation. HSP70 induction was dependent on the SAPK/ JNK, p38, and PI3K/Akt pathways. Differentiation and induction of HSP70 by a subset of HDAC inhibitors was also examined in human ES cells, which suggests that the phenomenon generally occurs in ES cells. A better understanding of the effects of HDAC inhibitors may give more insight into their application in stem cell biology.

Rational Design Synthesis and Evaluation of New Selective Inhibitors of Microbial Class II (Zinc Dependent) Fructose Bis-phosphate Aldolases

DOE Office of Scientific and Technical Information (OSTI.GOV)

R Daher; M Coincon; M Fonvielle

2011-12-31

We report the synthesis and biochemical evaluation of several selective inhibitors of class II (zinc dependent) fructose bis-phosphate aldolases (Fba). The products were designed as transition-state analogues of the catalyzed reaction, structurally related to the substrate fructose bis-phosphate (or sedoheptulose bis-phosphate) and based on an N-substituted hydroxamic acid, as a chelator of the zinc ion present in active site. The compounds synthesized were tested on class II Fbas from various pathogenic microorganisms and, by comparison, on a mammalian class I Fba. The best inhibitor shows Ki against class II Fbas from various pathogens in the nM range, with very highmore » selectivity (up to 105). Structural analyses of inhibitors in complex with aldolases rationalize and corroborate the enzymatic kinetics results. These inhibitors represent lead compounds for the preparation of new synthetic antibiotics, notably for tuberculosis prophylaxis.« less

HDAC Inhibitors Disrupt Programmed Resistance to Apoptosis During Drosophila Development.

PubMed

Kang, Yunsik; Marischuk, Khailee; Castelvecchi, Gina D; Bashirullah, Arash

2017-06-07

We have previously shown that the ability to respond to apoptotic triggers is regulated during Drosophila development, effectively dividing the fly life cycle into stages that are either sensitive or resistant to apoptosis. Here, we show that the developmentally programmed resistance to apoptosis involves transcriptional repression of critical proapoptotic genes by histone deacetylases (HDACs). Administration of HDAC inhibitors (HDACi), like trichostatin A or suberoylanilide hydroxamic acid, increases expression of proapoptotic genes and is sufficient to sensitize otherwise resistant stages. Conversely, reducing levels of proapoptotic genes confers resistance to otherwise sensitive stages. Given that resistance to apoptosis is a hallmark of cancer cells, and that HDACi have been recently added to the repertoire of FDA-approved agents for cancer therapy, our results provide new insights for how HDACi help kill malignant cells and also raise concerns for their potential unintended effects on healthy cells. Copyright © 2017 Kang et al.

The evolution of the matrix metalloproteinase inhibitor drug discovery program at abbott laboratories.

PubMed

Wada, Carol K

2004-01-01

Matrix metalloproteinases (MMPs) have been implicated in several pathologies. At Abbott Laboratories, the matrix metalloproteinases inhibitor drug discovery program has focused on the discovery of a potent, selective, orally bioavailable MMP inhibitor for the treatment of cancer. The program evolved from early succinate-based inhibitors to utilizing in-house technology such as SAR by NMR to develop a novel class of biaryl hydroxamate MMP inhibitors. The metabolic instability of the biaryl hydroxamates led to the discovery of a new class of N-formylhydroxylamine (retrohydroxamate) biaryl ethers, exemplified by ABT-770 (16). Toxicity issues with this pre-clinical candidate led to the discovery of another novel class of retrohydroxamate MMP inhibitors, the phenoxyphenyl sulfones such as ABT-518 (19j). ABT-518 is a potent, orally bioavailable, selective inhibitor of MMP-2 and 9 over MMP-1 that has been evaluated in Phase I clinical trials in cancer patients.

Siderophore-mediated iron acquisition mechanisms in Vibrio vulnificus biotype 2.

PubMed Central

Biosca, E G; Fouz, B; Alcaide, E; Amaro, C

1996-01-01

Vibrio vulnificus biotype 2 is a primary pathogen for eels and, as has recently been suggested, an opportunistic pathogen for humans. In this study we have investigated the ability of V. vulnificus biotype 2 to obtain iron by siderophore-mediated mechanisms and evaluated the importance of free iron in vibriosis. The virulence degree for eels was dependent on iron availability from host fluids, as was revealed by a reduction in the 50% lethal dose for iron-overloaded eels. This biotype produced both phenolate- and hydroxamate-type siderophores of an unknown nature and two new outer membrane proteins of around 84 and 72 kDa in response to iron starvation. No alterations in lipopolysaccharide patterns were detected in response to iron stress. Finally, our data suggest that V. vulnificus biotype 2 uses the hydroxamate-type siderophore for removal of iron from transferrin rather than relying on a receptor for this iron-binding protein. PMID:8975620

Adsorption and detection of Escherichia coli using an Au substrate modified with a catecholate-type artificial siderophore-Fe3+ complex.

PubMed

Inomata, Tomohiko; Tanabashi, Hirohito; Funahashi, Yasuhiro; Ozawa, Tomohiro; Masuda, Hideki

2013-12-07

A catecholate-type artificial siderophore with a terminal-NH2 group (1) and its Fe(3+) complex (2) were prepared. Siderophore 1 was characterized by (1)H NMR, FT-IR, and ESI-TOF MS spectroscopy. The corresponding Fe(3+) complex 2 was obtained by reaction of 1 with Fe(acac)3. The absorption band at 500 nm (ε = 4670 M(-1) cm(-1) at pH 7.0) of the electronic absorption spectrum of 2 is assignable as the LMCT (O(catecholate) → Fe(3+)) absorption band. This band indicates the formation of the Fe(3+) complex of 1. The biological activity of 2 with respect to Escherichia coli was clearly confirmed by observing that it permeates into the cell membrane. The self-assembled monolayer of 2 on an Au substrate, 2/Au, was prepared and its preparation was confirmed by FT-IR reflection-absorption spectroscopy (IR-RAS) and cyclic voltammetry (CV). Furthermore, a quartz crystal microbalance (QCM) chip modified with 2 effectively adsorbed E. coli. M. flavescens, an organism which is incapable of synthesizing siderophores and must therefore use exogenous hydroxamate-type siderophores for growth, did not adsorb on 2/Au. In contrast, E. coli did not adsorb on the hydroxamate-type artificial siderophore-Fe(3+) complex (3)-modified Au substrate, 3/Au. These results provide preliminary evidence that microbes recognized Fe(3+) ion-bound siderophores on the surface. The detection limit of 2/Au was ∼10(4) CFU mL(-1).

A comparative study based on docking and molecular dynamics simulations over HDAC-tubulin dual inhibitors.

PubMed

Hassanzadeh, Malihe; Bagherzadeh, Kowsar; Amanlou, Massoud

2016-11-01

Nowadays the ability to prediction of complex behavior rationally based on the computational approaches has been a successful technique in drug discovery. In the present study interactions of a new series of hybrids, which were made by linking colchicine as a tubulin inhibitor and suberoylanilide hydroxamic acid (SAHA) as a HDAC inhibitor, with HDAC8 and HDAC1 were investigated and compared. This research has been facilitated by the availability of experimental information besides employing docking methodology as well as classical molecular dynamics simulations and binding free energy calculation were performed. The obtained findings indicate different modes of interactions and inhibition strengths of the studied inhibitors for HDAC8 and HDAC1. HDAC8 binding free energies (-34.35 to -26.27kcal/mol) revealed higher binding affinity to HDAC8 compared to HDAC1 (-33.17 to -7.99kcal/mol). The binding energy contribution of each residue with the hybrid compounds 4a-4e within the active site of HDAC1 and HDAC8 was analyzed and the results confirmed the rule of key amino acids in interaction with the hybrid compounds. Copyright © 2016 Elsevier Inc. All rights reserved.

Potential of chromatin modifying compounds for the treatment of Alzheimer's disease

PubMed Central

Karagiannis, Tom C.; Ververis, Katherine

2012-01-01

Alzheimer's disease is a very common progressive neurodegenerative disorder affecting the learning and memory centers in the brain. The hallmarks of disease are the accumulation of β-amyloid neuritic plaques and neurofibrillary tangles formed by abnormally phosphorylated tau protein. Alzheimer's disease is currently incurable and there is an intense interest in the development of new potential therapies. Chromatin modifying compounds such as sirtuin modulators and histone deacetylase inhibitors have been evaluated in models of Alzheimer's disease with some promising results. For example, the natural antioxidant and sirtuin 1 activator resveratrol has been shown to have beneficial effects in animal models of disease. Similarly, numerous histone deacetylase inhibitors including Trichostatin A, suberoylanilide hydroxamic acid, valproic acid and phenylbutyrate reduction have shown promising results in models of Alzheimer's disease. These beneficial effects include a reduction of β-amyloid production and stabilization of tau protein. In this review we provide an overview of the histone deacetylase enzymes, with a focus on enzymes that have been identified to have an important role in the pathobiology of Alzheimer's disease. Further, we discuss the potential for pharmacological intervention with chromatin modifying compounds that modulate histone deacetylase enzymes. PMID:22953035

Potential of chromatin modifying compounds for the treatment of Alzheimer's disease.

PubMed

Karagiannis, Tom C; Ververis, Katherine

2012-01-01

Alzheimer's disease is a very common progressive neurodegenerative disorder affecting the learning and memory centers in the brain. The hallmarks of disease are the accumulation of β-amyloid neuritic plaques and neurofibrillary tangles formed by abnormally phosphorylated tau protein. Alzheimer's disease is currently incurable and there is an intense interest in the development of new potential therapies. Chromatin modifying compounds such as sirtuin modulators and histone deacetylase inhibitors have been evaluated in models of Alzheimer's disease with some promising results. For example, the natural antioxidant and sirtuin 1 activator resveratrol has been shown to have beneficial effects in animal models of disease. Similarly, numerous histone deacetylase inhibitors including Trichostatin A, suberoylanilide hydroxamic acid, valproic acid and phenylbutyrate reduction have shown promising results in models of Alzheimer's disease. These beneficial effects include a reduction of β-amyloid production and stabilization of tau protein. In this review we provide an overview of the histone deacetylase enzymes, with a focus on enzymes that have been identified to have an important role in the pathobiology of Alzheimer's disease. Further, we discuss the potential for pharmacological intervention with chromatin modifying compounds that modulate histone deacetylase enzymes.

Controlling lipid oxidation via a biomimetic iron chelating active packaging material.

PubMed

Tian, Fang; Decker, Eric A; Goddard, Julie M

2013-12-18

Previously, a siderophore-mimetic metal chelating active packaging film was developed by grafting poly(hydroxamic acid) (PHA) from the surface of polypropylene (PP) films. The objective of the current work was to demonstrate the potential applicability of this PP-g-PHA film to control iron-promoted lipid oxidation in food emulsions. The iron chelating activity of this film was investigated, and the surface chemistry and color intensity of films were also analyzed after iron chelation. In comparison to the iron chelating activity in the free Fe(3+) solution, the PP-g-PHA film retained approximately 50 and 30% of its activity in nitrilotriacetic acid (NTA)/Fe(3+) and citric acid/Fe(3+) solutions, respectively (pH 5.0), indicating a strong chelating strength for iron. The ability of PP-g-PHA films to control lipid oxidation was demonstrated in a model emulsion system (pH 3.0). PP-g-PHA films performed even better than ethylenediaminetetraacetic acid (EDTA) in preventing the formation of volatile oxidation products. The particle size and ζ potential results of emulsions indicated that PP-g-PHA films had no adverse effects on the stability of the emulsion system. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) analysis suggested a non-migratory nature of the PP-g-PHA film surface. These results suggest that such biomimetic, non-migratory metal chelating active packaging films have commercial potential in protecting foods against iron-promoted lipid oxidation.

Fundamental Chemical Kinetic And Thermodynamic Data For Purex Process Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, R.J.; Fox, O.D.; Sarsfield, M.J.

2007-07-01

To support either the continued operations of current reprocessing plants or the development of future fuel processing using hydrometallurgical processes, such as Advanced Purex or UREX type flowsheets, the accurate simulation of Purex solvent extraction is required. In recent years we have developed advanced process modeling capabilities that utilize modern software platforms such as Aspen Custom Modeler and can be run in steady state and dynamic simulations. However, such advanced models of the Purex process require a wide range of fundamental data including all relevant basic chemical kinetic and thermodynamic data for the major species present in the process. Thismore » paper will summarize some of these recent process chemistry studies that underpin our simulation, design and testing of Purex solvent extraction flowsheets. Whilst much kinetic data for actinide redox reactions in nitric acid exists in the literature, the data on reactions in the diluted TBP solvent phase is much rarer. This inhibits the accurate modelization of the Purex process particularly when species show a significant extractability in to the solvent phase or when cycling between solvent and aqueous phases occurs, for example in the reductive stripping of Pu(IV) by ferrous sulfamate in the Magnox reprocessing plant. To support current oxide reprocessing, we have investigated a range of solvent phase reactions: - U(IV)+HNO{sub 3}; - U(IV)+HNO{sub 2}; - U(IV)+HNO{sub 3} (Pu catalysis); - U(IV)+HNO{sub 3} (Tc catalysis); - U(IV)+ Np(VI); - U(IV)+Np(V); - Np(IV)+HNO{sub 3}; - Np(V)+Np(V); Rate equations have been determined for all these reactions and kinetic rate constants and activation energies are now available. Specific features of these reactions in the TBP phase include the roles of water and hydrolyzed intermediates in the reaction mechanisms. In reactions involving Np(V), cation-cation complex formation, which is much more favourable in TBP than in HNO{sub 3}, also occurs and complicates the redox chemistry. Whilst some features of the redox chemistry in TBP appear similar to the corresponding reactions in aqueous HNO{sub 3}, there are notable differences in rates, the forms of the rate equations and mechanisms. Secondly, to underpin the development of advanced single cycle flowsheets using the complexant aceto-hydroxamic acid, we have also characterised in some detail its redox chemistry and solvent extraction behaviour with both Np and Pu ions. We find that simple hydroxamic acids are remarkably rapid reducing agents for Np(VI). They also reduce Pu(VI) and cause a much slower reduction of Pu(IV) through a complex mechanism involving acid hydrolysis of the ligand. AHA is a strong hydrophilic and selective complexant for the tetravalent actinide ions as evidenced by stability constant and solvent extraction data for An(IV), M(III) and U(VI) ions. This has allowed the successful design of U/Pu+Np separation flowsheets suitable for advanced fuel cycles. (authors)« less

Endogeous sulfur dioxide protects against oleic acid-induced acute lung injury in association with inhibition of oxidative stress in rats.

PubMed

Chen, Siyao; Zheng, Saijun; Liu, Zhiwei; Tang, Chaoshu; Zhao, Bin; Du, Junbao; Jin, Hongfang

2015-02-01

The role of endogenous sulfur dioxide (SO2), an efficient gasotransmitter maintaining homeostasis, in the development of acute lung injury (ALI) remains unidentified. We aimed to investigate the role of endogenous SO2 in the pathogenesis of ALI. An oleic acid (OA)-induced ALI rat model was established. Endogenous SO2 levels, lung injury, oxidative stress markers and apoptosis were examined. OA-induced ALI rats showed a markedly downregulated endogenous SO2/aspartate aminotransferase 1 (AAT1)/AAT2 pathway and severe lung injury. Chemical colorimetry assays demonstrated upregulated reactive oxygen species generation and downregulated antioxidant capacity in OA-induced ALI rats. However, SO2 increased endogenous SO2 levels, protected against oxidative stress and alleviated ALI. Moreover, compared with OA-treated cells, in human alveolar epithelial cells SO2 downregulated O2(-) and OH(-) generation. In contrast, L-aspartic acid-β-hydroxamate (HDX, Sigma-Aldrich Corporation), an inhibitor of endogenous SO2 generating enzyme, promoted free radical generation, upregulated poly (ADP-ribose) polymerase expression, activated caspase-3, as well as promoted cell apoptosis. Importantly, apoptosis could be inhibited by the free radical scavengers glutathione (GSH) and N-acetyl-L-cysteine (NAC). The results suggest that SO2/AAT1/AAT2 pathway might protect against the development of OA-induced ALI by inhibiting oxidative stress.

Inhibition of monomethylarsonous acid (MMA(III))-induced cell malignant transformation through restoring dysregulated histone acetylation.

PubMed

Ge, Yichen; Gong, Zhihong; Olson, James R; Xu, Peilin; Buck, Michael J; Ren, Xuefeng

2013-10-04

Inorganic arsenic (iAs) and its high toxic metabolite, monomethylarsonous acid (MMA(III)), are able to induce malignant transformation of human cells. Chronic exposure to these chemicals is associated with an increased risk of developing multiple cancers in human. However, the mechanisms contributing to iAs/MMA(III)-induced cell malignant transformation and carcinogenesis are not fully elucidated. We recently showed that iAs/MMA(III) exposure to human cells led to a decreased level of histone acetylation globally, which was associated with an increased sensitivity to arsenic cytotoxicity. In the current study, it demonstrated that prolonged exposure to low-level MMA(III) in human urothelial cells significantly increased the expression and activity of histone deacetylases (HDACs) with an associated reduction of histone acetylation levels both globally and lysine specifically. Administration of the HDAC inhibitor, suberoylanilide hydroxamic acid (SAHA), at 4 weeks after the initial MMA(III) treatment inhibited the MMA(III)-mediated up-regulation of the expression and activities of HDACs, leading to increase histone acetylation and prevention of MMA(III)-induced malignant transformation. These new findings suggest that histone acetylation dysregulation may be a key mechanism in MMA(III)-induced malignant transformation and carcinogenesis, and that HDAC inhibitors could be targeted to prevent or treat iAs-related cancers. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

The effects of a novel aliphatic-chain hydroxamate derivative WMJ-S-001 in HCT116 colorectal cancer cell death

PubMed Central

Huang, Yu-Han; Huang, Shiu-Wen; Hsu, Ya-Fen; Ou, George; Huang, Wei-Jan; Hsu, Ming-Jen

2015-01-01

Hydroxamate derivatives have attracted considerable attention due to their broad pharmacological properties and have been extensively investigated. We recently demonstrated that WMJ-S-001, a novel aliphatic hydroxamate derivative, exhibits anti-inflammatory and anti-angiogenic activities. In this study, we explored the underlying mechanisms by which WMJ-S-001 induces HCT116 colorectal cancer cell death. WMJ-S-001 inhibited cell proliferation and induced cell apoptosis in HCT116 cells. These actions were associated with AMP-activated protein kinase (AMPK) and p38 mitogen-activated protein kinase (MAPK) activation, p53 phosphorylation and acetylation, as well as the modulation of p21cip/Waf1, cyclin D1, survivin and Bax. AMPK-p38MAPK signaling blockade reduced WMJ-S-001-induced p53 phosphorylation. Transfection with AMPK dominant negative mutant (DN) reduced WMJ-S-001’s effects on p53 and Sp1 binding to the survivn promoter region. Transfection with HDAC3-Flag or HDAC4-Flag also abrogated WMJ-S-001’s enhancing effect on p53 acetylation. WMJ-S-001’s actions on p21cip/Waf1, cyclin D1, survivin, Bax were reduced in p53-null HCT116 cells. Furthermore, WMJ-S-001 was shown to suppress the growth of subcutaneous xenografts of HCT116 cells in vivo. In summary, the death of HCT116 colorectal cancer cells exposed to WMJ-S-001 may involve AMPK-p38MAPK-p53-survivin cascade. These results support the role of WMJ-S-001 as a potential drug candidate and warrant the clinical development in the treatment of cancer. PMID:26510776

One Enzyme, Three Metabolites: Shewanella algae Controls Siderophore Production via the Cellular Substrate Pool.

PubMed

Rütschlin, Sina; Gunesch, Sandra; Böttcher, Thomas

2017-05-18

Shewanella algae B516 produces avaroferrin, an asymmetric hydroxamate siderophore, which has been shown to inhibit swarming motility of Vibrio alginolyticus. We aimed to elucidate the biosynthesis of this siderophore and to investigate how S. algae coordinates the production of avaroferrin and its two symmetric counterparts. We reconstituted the reaction in vitro with the main enzyme AvbD and the putative biosynthetic precursors, and demonstrate that multispecificity of this enzyme results in the production of all three cyclic hydroxamate siderophores that were previously isolated as natural products from S. algae. Surprisingly, purified AvbD exhibited a clear preference for the larger cadaverine-derived substrate. In live cells, however, siderophore ratios are maximized toward avaroferrin production, and we demonstrate that these siderophore ratios are the result of a regulation on substrate pool level, which may allow rapid evolutionary adaptation to environmental changes. Our results thereby give insights into a unique evolutionary strategy toward metabolite diversity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Structure of the metal-dependent deacetylase LpxC from Yersinia enterocolitica complexed with the potent inhibitor CHIR-090 .

PubMed

Cole, Kathryn E; Gattis, Samuel G; Angell, Heather D; Fierke, Carol A; Christianson, David W

2011-01-18

The first committed step of lipid A biosynthesis is catalyzed by UDP-(3-O-((R)-3-hydroxymyristoyl))-N-acetylglucosamine deacetylase, a metal-dependent deacetylase also known as LpxC. Because lipid A is essential for bacterial viability, the inhibition of LpxC is an appealing therapeutic strategy for the treatment of Gram-negative bacterial infections. Here we report the 1.79 Å resolution X-ray crystal structure of LpxC from Yersinia enterocolitica (YeLpxC) complexed with the potent hydroxamate inhibitor CHIR-090. This enzyme is a nearly identical orthologue of LpxC from Yersinia pestis (99.7% sequence identity), the pathogen that causes bubonic plague. Similar to the inhibition of LpxC from Escherichia coli, CHIR-090 inhibits YeLpxC via a two-step slow, tight-binding mechanism with an apparent K(i) of 0.54 ± 0.14 nM followed by conversion of the E·I to E·I* species with a rate constant of 0.11 ± 0.01 min(-1). The structure of the LpxC complex with CHIR-090 shows that the inhibitor hydroxamate group chelates the active site zinc ion, and the "tail" of the inhibitor binds in the hydrophobic tunnel in the active site. This hydrophobic tunnel is framed by a βαβ subdomain that exhibits significant conformational flexibility as it accommodates inhibitor binding. CHIR-090 displays a 27 mm zone of inhibition against Y. enterocolitica in a Kirby-Bauer antibiotic assay, which is comparable to its reported activity against other Gram-negative species including E. coli and Pseudomonas aeruginosa. This study demonstrates that the inhibition of LpxC should be explored as a potential therapeutic and/or prophylatic response to infection by weaponized Yersinia species.

RAD51 potentiates synergistic effects of chemotherapy with PCI-24781 and cis-diamminedichloroplatinum on gastric cancer

PubMed Central

He, Wei-Ling; Li, Yu-Huang; Hou, Wei-Jian; Ke, Zun-Fu; Chen, Xin-Lin; Lu, Li-Ya; Cai, Shi-Rong; Song, Wu; Zhang, Chang-Hua; He, Yu-Long

2014-01-01

AIM: To explore the efficacy of PCI-24781, a broad-spectrum, hydroxamic acid-derived histone deacetylase inhibitor, in the treatment of gastric cancer (GC). METHODS: With or without treatment of PCI-24781 and/or cis-diamminedichloroplatinum (CDDP), GC cell lines were subjected to functional analysis, including cell growth, apoptosis and clonogenic assays. Chromatin immunoprecipitation and luciferase reporter assays were used to determine the interacting molecules and the activity of the enzyme. An in vivo study was carried out in GC xenograft mice. Cell culture-based assays were represented as mean ± SD. ANOVA tests were used to assess differences across groups. All pairwise comparisons between tumor weights among treatment groups were made using the Tukey-Kramer method for multiple comparison adjustment to control experimental-wise type I error rates. Significance was set at P < 0.05. RESULTS: PCI-24781 significantly reduced the growth of the GC cells, enhanced cell apoptosis and suppressed clonogenicity, and these effects synergized with the effects of CDDP. PCI-24781 modulated the cell cycle and significantly reduced the expression of RAD51, which is related to homologous recombination. Depletion of RAD51 augmented the biological functions of PCI-24781, CDDP and the combination treatment, whereas overexpressing RAD51 had the opposite effects. Increased binding of the transcription suppressor E2F4 on the RAD51 promoter appeared to play a major role in these processes. Furthermore, significant suppression of tumor growth and weight in vivo was obtained following PCI-24781 treatment, which synergized with the anticancer effect of CDDP. CONCLUSION: These data suggest that RAD51 potentiates the synergistic effects of chemotherapy with PCI-24781 and CDDP on GC. PMID:25110436

Alterations in histone acetylation following exposure to 60Co γ-rays and their relationship with chromosome damage in human lymphoblastoid cells.

PubMed

Tian, Xue-Lei; Lu, Xue; Feng, Jiang-Bin; Cai, Tian-Jing; Li, Shuang; Tian, Mei; Liu, Qing-Jie

2018-05-17

Chromosome damage is related to DNA damage and erroneous repair. It can cause cell dysfunction and ultimately induce carcinogenesis. Histone acetylation is crucial for regulating chromatin structure and DNA damage repair. Ionizing radiation (IR) can alter histone acetylation. However, variations in histone acetylation in response to IR exposure and the relationship between histone acetylation and IR-induced chromosome damage remains unclear. Hence, this study investigated the variation in the total acetylation levels of H3 and H4 in human lymphocytes exposed to 0-2 Gy 60 Co γ-rays. Suberoylanilide hydroxamic acid (SAHA), a histone deacetylase (HDAC) inhibitor, was added to modify the histone acetylation state of irradiated cells. Then, the total acetylation level, enzyme activity, dicentric plus centric rings (dic + r) frequencies, and micronucleus (MN) frequencies of the treated cells were analyzed. Results indicated that the acetylation levels of H3 and H4 significantly decreased at 1 and 24 h, respectively, after radiation exposure. The acetylation levels of H3 and H4 in irradiated groups treated with SAHA were significantly higher than those in irradiated groups that were not treated with SAHA. SAHA treatment inhibited HDAC activity in cells exposed to 0-1 Gy 60 Co γ-rays. SAHA treatment significantly decreased dic + r/cell and MN/cell in cells exposed to 0.5 or 1.0 Gy 60 Co γ-rays relative to that in cells that did not receive SAHA treatment. In conclusion, histone acetylation is significantly affected by IR and is involved in chromosome damage induced by 60 Co γ-radiation.

Design and synthetic considerations of matrix metalloproteinase inhibitors.

PubMed

Skotnicki, J S; Zask, A; Nelson, F C; Albright, J D; Levin, J I

1999-06-30

Experimental evidence confirms that the matrix metalloproteinases (MMPs) play a fundamental role in a wide variety of pathologic conditions that involve connective tissue destruction including osteoarthritis and rheumatoid arthritis, tumor metastasis and angiogenesis, corneal ulceration, multiple sclerosis, periodontal disease, and atherosclerosis. Modulation of MMP regulation is possible at several biochemical sites, but direct inhibition of enzyme action provides a particularly attractive target for therapeutic intervention. Hypotheses concerning inhibition of specific MMP(s) with respect to disease target and/or side-effect profile have emerged. Examples are presented of recent advances in medicinal chemistry approaches to the design of matrix metalloproteinase inhibitors (MMPIs), approaches that address structural requirements and that influence potency, selectivity, and bioavailability. Two important approaches to the design, synthesis, and biological evaluation of MMPIs are highlighted: (1) the invention of alternatives to hydroxamic acid zinc chelators and (2) the construction of nonpeptide scaffolds. One current example in each of these two approaches from our own work is described.

Notch3 overexpression enhances progression and chemoresistance of urothelial carcinoma.

PubMed

Zhang, Heng; Liu, Limei; Liu, Chungang; Pan, Jinhong; Lu, Gensheng; Zhou, Zhansong; Chen, Zhiwen; Qian, Cheng

2017-05-23

Abnormal activation of Notch signaling is involved in the etiology of various diseases, including cancer, but the association between Notch3 expression in urothelial cancer and clinical outcome remains unclear, and the molecular mechanisms underlying Notch3 signaling activation are not well defined. In this study we examined 59 urothelial cancer patients and found that Notch3 was more highly expressed in human urothelial cancer tissues than in non-tumorous bladder tissue samples, with Notch3 overexpression being associated with poor clinical outcome. Notch3 knockdown resulted in decreased proliferation of urothelial cancer cells in vitro and decreased xenograft tumor growth in vivo. In addition, Notch3 knockdown rendered urothelial cancer cells more sensitive to cisplatin. Furthermore, suberoylanilide hydroxamic acid (SAHA, a histone deacetylase [HDAC] inhibitor) induced acetylation of NOTCH3, downregulated Notch 3, prevented urothelial cancer cell proliferation, and induced cell cycle arrest. Taken together, these data suggested that Notch 3 overexpression promotes growth and chemoresistance in urothelial cancer.

Notch3 overexpression enhances progression and chemoresistance of urothelial carcinoma

PubMed Central

Zhang, Heng; Liu, Limei; Liu, Chungang; Pan, Jinhong; Lu, Gensheng; Zhou, Zhansong; Chen, Zhiwen; Qian, Cheng

2017-01-01

Abnormal activation of Notch signaling is involved in the etiology of various diseases, including cancer, but the association between Notch3 expression in urothelial cancer and clinical outcome remains unclear, and the molecular mechanisms underlying Notch3 signaling activation are not well defined. In this study we examined 59 urothelial cancer patients and found that Notch3 was more highly expressed in human urothelial cancer tissues than in non-tumorous bladder tissue samples, with Notch3 overexpression being associated with poor clinical outcome. Notch3 knockdown resulted in decreased proliferation of urothelial cancer cells in vitro and decreased xenograft tumor growth in vivo. In addition, Notch3 knockdown rendered urothelial cancer cells more sensitive to cisplatin. Furthermore, suberoylanilide hydroxamic acid (SAHA, a histone deacetylase [HDAC] inhibitor) induced acetylation of NOTCH3, downregulated Notch 3, prevented urothelial cancer cell proliferation, and induced cell cycle arrest. Taken together, these data suggested that Notch 3 overexpression promotes growth and chemoresistance in urothelial cancer. PMID:28416766

SAHA-based novel HDAC inhibitor design by core hopping method.

PubMed

Zang, Lan-Lan; Wang, Xue-Jiao; Li, Xiao-Bo; Wang, Shu-Qing; Xu, Wei-Ren; Xie, Xian-Bin; Cheng, Xian-Chao; Ma, Huan; Wang, Run-Ling

2014-11-01

The catalytic activity of the histone deacetylase (HDAC) is directly relevant to the pathogenesis of cancer, and HDAC inhibitors represented a promising strategy for cancer therapy. SAHA (suberoanilide hydroxamic acid), an effective HDAC inhibitor, is an anti-cancer agent against T-cell lymphoma. However, SAHA has adverse effects such as poor pharmacokinetic properties and severe toxicities in clinical use. In order to identify better HDAC inhibitors, a compound database was established by core hopping of SAHA, which was then docked into HDAC-8 (PDB ID: 1T69) active site to select a number of candidates with higher docking score and better interaction with catalytic zinc ion. Further ADMET prediction was done to give ten compounds. Molecular dynamics simulation of the representative compound 101 was performed to study the stability of HDAC8-inhibitor system. This work provided an approach to design novel high-efficiency HDAC inhibitors with better ADMET properties. Copyright © 2014 Elsevier Inc. All rights reserved.

Mass Spectrometric Characterization of Benzoxazinoid Glycosides from Rhizopus-Elicited Wheat (Triticum aestivum) Seedlings.

PubMed

de Bruijn, Wouter J C; Vincken, Jean-Paul; Duran, Katharina; Gruppen, Harry

2016-08-17

Benzoxazinoids function as defense compounds and have been suggested to possess health-promoting effects. In this work, the mass spectrometric behavior of benzoxazinoids from the classes benzoxazin-3-ones (with subclasses lactams, hydroxamic acids, and methyl derivatives) and benzoxazolinones was studied. Wheat seeds were germinated with simultaneous elicitation by Rhizopus. The seedling extract was screened for the presence of benzoxazinoid (glycosides) using reversed-phase ultra-high-performance liquid chromatography with photodiode array detection coupled in line to multiple-stage mass spectrometry (RP-UHPLC-PDA-MS(n)). Benzoxazin-3-ones from the different subclasses showed distinctly different ionization and fragmentation behaviors. These features were incorporated into a newly proposed decision guideline to aid the classification of benzoxazinoids. Glycosides of the methyl derivative 2-hydroxy-4-methoxy-1,4-benzoxazin-3-one were tentatively identified for the first time in wheat. We conclude that wheat seedlings germinated with simultaneous fungal elicitation contain a diverse array of benzoxazinoids, mainly constituted by benzoxazin-3-one glycosides.

Trilysinoyl oleylamide-based cationic liposomes for systemic co-delivery of siRNA and an anticancer drug.

PubMed

Shim, Gayong; Han, Su-Eun; Yu, Yong-Hee; Lee, Sangbin; Lee, Han Young; Kim, Kwangmeyung; Kwon, Ick Chan; Park, Tae Gwan; Kim, Young Bong; Choi, Yong Seok; Kim, Chan-Wha; Oh, Yu-Kyoung

2011-10-10

Oligolysine-based cationic lipid derivatives were synthesized for delivery of siRNA, and formulated into cationic liposomes. Among various oligolysine-based lipid derivatives differing in lysine residue number and lipid moiety, trilysinoyl oleylamide (TLO)-based liposomes (TLOL) showed the highest delivery efficiency combined with minimal cytotoxicity. Delivery of siRNA using TLOL silenced target genes both in vitro and in vivo. In green fluorescent protein (GFP)-expressing tumor tissue, a significant reduction of fluorescence was observed after intratumoral administration of siGFP using TLOL compared with control siGL2. Intravenous administration of siMcl1 employing pegylated TLOL (pTLOL) reduced the expression of human Mcl1 protein in KB-xenografted tumor tissue. Despite the reduction in target protein Mcl1 expression following such systemic delivery, tumor growth was only slightly reduced compared to a siGL2-treated control group. To potentiate the anticancer activity of siMcl1, the anticancer drug suberoylanilide hydroxamic acid (SAHA) was additionally encapsulated in pTLOL. After intravenous administration of siMcl1 using SAHA-loaded pTLOL (pSTLOL), a significant reduction in tumor growth was observed compared to that seen in animals treated with free SAHA or siGL2 complexed with pSTLOL. The results indicate that pTLOL could be further developed as a systemic delivery system for synergistic anticancer siRNA and a drug. Copyright © 2010 Elsevier B.V. All rights reserved.

Peptide Deformylase Inhibitors as Potent Antimycobacterial Agents▿ †

PubMed Central

Teo, Jeanette W. P.; Thayalan, Pamela; Beer, David; Yap, Amelia S. L.; Nanjundappa, Mahesh; Ngew, Xinyi; Duraiswamy, Jeyaraj; Liung, Sarah; Dartois, Veronique; Schreiber, Mark; Hasan, Samiul ; Cynamon, Michael; Ryder, Neil S.; Yang, Xia; Weidmann, Beat; Bracken, Kathryn ; Dick, Thomas; Mukherjee, Kakoli

2006-01-01

Peptide deformylase (PDF) catalyzes the hydrolytic removal of the N-terminal formyl group from nascent proteins. This is an essential step in bacterial protein synthesis, making PDF an attractive target for antibacterial drug development. Essentiality of the def gene, encoding PDF from Mycobacterium tuberculosis, was demonstrated through genetic knockout experiments with Mycobacterium bovis BCG. PDF from M. tuberculosis strain H37Rv was cloned, expressed, and purified as an N-terminal histidine-tagged recombinant protein in Escherichia coli. A novel class of PDF inhibitors (PDF-I), the N-alkyl urea hydroxamic acids, were synthesized and evaluated for their activities against the M. tuberculosis PDF enzyme as well as their antimycobacterial effects. Several compounds from the new class had 50% inhibitory concentration (IC50) values of <100 nM. Some of the PDF-I displayed antibacterial activity against M. tuberculosis, including MDR strains with MIC90 values of <1 μM. Pharmacokinetic studies of potential leads showed that the compounds were orally bioavailable. Spontaneous resistance towards these inhibitors arose at a frequency of ≤5 × 10−7 in M. bovis BCG. DNA sequence analysis of several spontaneous PDF-I-resistant mutants revealed that half of the mutants had acquired point mutations in their formyl methyltransferase gene (fmt), which formylated Met-tRNA. The results from this study validate M. tuberculosis PDF as a drug target and suggest that this class of compounds have the potential to be developed as novel antimycobacterial agents. PMID:16966397

Drug forecast - the peptide deformylase inhibitors as antibacterial agents.

PubMed

Guay, David R P

2007-08-01

The relatively rapid development of microbial resistance after the entry of every new antimicrobial into the marketplace necessitates a constant supply of new agents to maintain effective pharmacotherapy. Despite extensive efforts to identify novel lead compounds from molecular targets, only the peptide deformylase inhibitors (PDIs) have shown any real promise, with some advancing to phase I human trials. Bacterial peptide deformylase, which catalyzes the removal of the N-formyl group from N-terminal methionine following translation, is essential for bacterial protein synthesis, growth, and survival. The majority of PDIs are pseudopeptide hydroxamic acids and two of these (IV BB-83698 and oral NVP LBM-415) entered phase I human trials. However, agents to the present have suffered from major potential liabilities. Their in vitro activity has been limited to gram-positive aerobes and some anaerobes and has been quite modest against the majority of such species (MIC(90) values ranging from 1-8 mg/L). They have exerted bacteriostatic, not bacteriocidal, activity, thus reducing their potential usefulness in the management of serious infections in the immunocompromised. The relative ease with which microorganisms have been able to develop resistance and the multiple available mechanisms of resistance (mutations in fmt, defB, folD genes; AcrAB/TolC efflux pump; overexpression of peptide deformylase) are worrisome. These could portend a short timespan of efficacy after marketing. Despite these current liabilities, further pursuit of more potent and broader spectrum PDIs which are less susceptible to bacterial mechanisms of resistance is still warranted.

[Lentivirus-mediated shRNA silencing of LAMP2A inhibits the proliferation of multiple myeloma cells].

PubMed

Li, Lixuan; Li, Jia

2015-05-01

To study the effects of lentivirus-mediated short hairpin RNA (shRNA) silencing of lysosome-associated membrane protein type 2A (LAMP2A) expression on the proliferation of multiple myeloma cells. The constructed shRNA lentiviral vector was applied to infect human multiple myeloma cell line MM.1S, and stable expression cell line was obtained by puromycin screening. Western blotting was used to verify the inhibitory effect on LAMP2A protein expression. MTT assay was conducted to detect the effect of knocked-down LAMP2A on MM.1S cell proliferation, and the anti-tumor potency of suberoylanilide hydroxamic acid (SAHA) against the obtained MM.1S LAMP2A(shRNA) stable cell line. Lactate assay was performed to observe the impact of low LAMP2A expression on cell glycolysis. The stable cell line with low LAMP2A expression were obtained with the constructed human LAMP2A-shRNA lentiviral vector. Down-regulation of LAMP2A expression significantly inhibited MM.1S cell proliferation and enhanced the anti-tumor activity of SAHA. Interestingly, decreased LAMP2A expression also inhibited MM.1S cell lactic acid secretion. Down-regulation of LAMP2A expression could inhibit cell proliferation in multiple myeloma cells.

SCL/TAL1-mediated transcriptional network enhances megakaryocytic specification of human embryonic stem cells.

PubMed

Toscano, Miguel G; Navarro-Montero, Oscar; Ayllon, Veronica; Ramos-Mejia, Veronica; Guerrero-Carreno, Xiomara; Bueno, Clara; Romero, Tamara; Lamolda, Mar; Cobo, Marien; Martin, Francisco; Menendez, Pablo; Real, Pedro J

2015-01-01

Human embryonic stem cells (hESCs) are a unique in vitro model for studying human developmental biology and represent a potential source for cell replacement strategies. Platelets can be generated from cord blood progenitors and hESCs; however, the molecular mechanisms and determinants controlling the in vitro megakaryocytic specification of hESCs remain elusive. We have recently shown that stem cell leukemia (SCL) overexpression accelerates the emergence of hemato-endothelial progenitors from hESCs and promotes their subsequent differentiation into blood cells with higher clonogenic potential. Given that SCL participates in megakaryocytic commitment, we hypothesized that it may potentiate megakaryopoiesis from hESCs. We show that ectopic SCL expression enhances the emergence of megakaryocytic precursors, mature megakaryocytes (MKs), and platelets in vitro. SCL-overexpressing MKs and platelets respond to different activating stimuli similar to their control counterparts. Gene expression profiling of megakaryocytic precursors shows that SCL overexpression renders a megakaryopoietic molecular signature. Connectivity Map analysis reveals that trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA), both histone deacetylase (HDAC) inhibitors, functionally mimic SCL-induced effects. Finally, we confirm that both TSA and SAHA treatment promote the emergence of CD34(+) progenitors, whereas valproic acid, another HDAC inhibitor, potentiates MK and platelet production. We demonstrate that SCL and HDAC inhibitors are megakaryopoiesis regulators in hESCs.

HDAC Inhibitors as Novel Anti-Cancer Therapeutics.

PubMed

De Souza, Cristabelle; Chatterji, Biswa Prasun

2015-01-01

Malignant growth of cells is a condition characterized by unchecked cellular proliferation, genetic instability and epigenetic dysregulation. Up-regulated HDAC (Histone Deacetylase) enzyme activity is associated with a closed chromatin assembly and subsequent gene repression, forming a characteristic feature of malignantly transformed cells. Novel therapeutics are now targeting the zinc containing HDAC enzymes for treating various types of cancers. Recently, a spate of drugs acting via HDAC inhibition have been undergoing clinical trials and several patents present exciting molecules like PCI-24781 (Abexinostat), ITF- 2357 (Givinostat); MS-275 (Entinostat), MGCD 0103 (Mocetinostat), LBH-589 (Panobinostat), FK228 (Romidepsin), PXD-101 (Belinostat) and Valproic Acid to be used as alternatives or adjuvants to traditional chemotherapeutics. However, only three HDAC inhibitors have acquired FDA approval till date. Recently, PXD-101 obtained FDA approval for the treatment of Refractory or Relapsed Peripheral T cell lymphoma. The current article reviews patents that have introduced novel molecules that are HDAC isoform specific, superior to first generation HDAC inhibitors like SAHA (Suberoylanilide Hydroxamic Acid) and TSA (Trichostatin A) and can be modified structurally to reduce toxic side effects and increase specificity. These molecules can combine the best characteristics of an ideal HDAC inhibiting drug either as monotherapy or in combinatorial therapy for cancer treatment thus, indicating promise to be included in the next generation of target specific HDAC inhibiting drugs.

Histone deacetylase inhibitors augment doxorubicin-induced DNA damage in cardiomyocytes.

PubMed

Ververis, Katherine; Rodd, Annabelle L; Tang, Michelle M; El-Osta, Assam; Karagiannis, Tom C

2011-12-01

Histone deacetylase inhibitors have emerged as a new class of anticancer therapeutics with suberoylanilide hydroxamic acid (Vorinostat) and depsipeptide (Romidepsin) already being approved for clinical use. Numerous studies have identified that histone deacetylase inhibitors will be most effective in the clinic when used in combination with conventional cancer therapies such as ionizing radiation and chemotherapeutic agents. One promising combination, particularly for hematologic malignancies, involves the use of histone deacetylase inhibitors with the anthracycline, doxorubicin. However, we previously identified that trichostatin A can potentiate doxorubicin-induced hypertrophy, the dose-limiting side-effect of the anthracycline, in cardiac myocytes. Here we have the extended the earlier studies and evaluated the effects of combinations of the histone deacetylase inhibitors, trichostatin A, valproic acid and sodium butyrate on doxorubicin-induced DNA double-strand breaks in cardiomyocytes. Using γH2AX as a molecular marker for the DNA lesions, we identified that all of the broad-spectrum histone deacetylase inhibitors tested augment doxorubicin-induced DNA damage. Furthermore, it is evident from the fluorescence photomicrographs of stained nuclei that the histone deacetylase inhibitors also augment doxorubicin-induced hypertrophy. These observations highlight the importance of investigating potential side-effects, in relevant model systems, which may be associated with emerging combination therapies for cancer.

HDAC inhibitor-loaded bone cement for advanced local treatment of osteosarcoma and chondrosarcoma.

PubMed

Tonak, Marcus; Becker, Marc; Graf, Claudine; Eckhard, Lukas; Theobald, Matthias; Rommens, Pol-Maria; Wehler, Thomas C; Proschek, Dirk

2014-11-01

The treatment of osteosarcoma, especially wide resection, is challenging. An additional local drug therapy after resection using anti-neoplastic bone cement (Polymethylmethacrylate (PMMA)) could help improve the outcome of therapy. In this study, we evaluated the effects of PMMA loaded with valproic acid (VPA) and suberoylanilide hydroxamic acid (SAHA) on the cell activity of a SaOs-2 cell culture, as well as the elution rate of the drugs out of the bone cement. In our experiments, we used the SaOs-2 osteosarcoma and the SW1353 chondrosarcoma cell line. Bone cement clots (5 g) were prepared and loaded with different drug concentrations of VPA (25 mg and 50 mg) and SAHA (1 mg, 2.5 mg and 5 mg). Two control groups were established, one with a native cement clot, the other with human mesenchymal stem cells, in order to evaluate toxicity on non tumor-cells. Cell activity was measured using an Alamar Blue assay on days 1, 2, 3, 4 and 7. The cement clots were additionally examined in a material testing unit for biomechanical and structural changes. Tumor cells showed a significant and complete reduction of activity under therapy with VPA and SAHA. Drug release of VPA was extensive between days 0 and 3 and decreased progressively to day 7. Cumulative drug concentration in the medium continuously increased. Biomechanical testing of the cement clots showed no differences in stability and architecture compared to the control group. SaOs-2 and SW1353 cells with medium from native cement clots without drug therapy presented a cell activity of 100% in all groups and during all measurements. Human mesenchymal stem cells were not significantly affected during therapy with VPA and low concentrations of SAHA. In contrast, cell activity of human mesenchymal stem cells was significantly reduced under therapy with higher concentrations of SAHA, with an approximately linear decrease between days 0-3 and a rapidly decreasing activity between days 4-7. A local cytotoxic therapy in the treatment of osteosarcoma and chondrosarcoma might improve the rate of metastasis and survival of patients. Our results present an encouraging approach to loading PMMA with anti-neoplastic drugs. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Development of Thioaryl-Based Matrix Metalloproteinase-12 Inhibitors with Alternative Zinc-Binding Groups: Synthesis, Potentiometric, NMR, and Crystallographic Studies.

PubMed

Nuti, Elisa; Cuffaro, Doretta; Bernardini, Elisa; Camodeca, Caterina; Panelli, Laura; Chaves, Sílvia; Ciccone, Lidia; Tepshi, Livia; Vera, Laura; Orlandini, Elisabetta; Nencetti, Susanna; Stura, Enrico A; Santos, M Amélia; Dive, Vincent; Rossello, Armando

2018-05-24

Matrix metalloproteinase-12 (MMP-12) selective inhibitors could play a role in the treatment of lung inflammatory and cardiovascular diseases. In the present study, the previously reported 4-methoxybiphenylsulfonyl hydroxamate and carboxylate based inhibitors (1b and 2b) were modified to enhance their selectivity for MMP-12. In the newly synthesized thioaryl derivatives, the nature of the zinc binding group (ZBG) and the sulfur oxidation state were changed. Biological assays carried out in vitro on human MMPs with the resulting compounds led to identification of a sulfide, 4a, bearing an N-1-hydroxypiperidine-2,6-dione (HPD) group as new ZBG. Compound 4a is a promising hit compound since it displayed a nanomolar affinity for MMP-12 with a marked selectivity over MMP-9, MMP-1, and MMP-14. Solution complexation studies with Zn 2+ were performed to characterize the chelating abilities of the new compounds and confirmed the bidentate binding mode of HPD derivatives. X-ray crystallography studies using MMP-12 and MMP-9 catalytic domains were carried out to rationalize the biological results.

The effect of various zinc binding groups on inhibition of histone deacetylases 1-11.

PubMed

Madsen, Andreas S; Kristensen, Helle M E; Lanz, Gyrithe; Olsen, Christian A

2014-03-01

Histone deacetylases (HDACs) have the ability to cleave the acetyl groups of ε-N-acetylated lysine residues in a variety of proteins. Given that human cells contain thousands of different acetylated lysine residues, HDACS may regulate a wide variety of processes including some implicated in conditions such as cancer and neurodegenerative disorders. Herein we report the synthesis and in vitro biochemical profiling of a series of compounds, including known inhibitors as well as novel chemotypes, that incorporate putative new zinc binding domains. By evaluating the compound collection against all 11 recombinant human HDACs, we found that the trifluoromethyl ketone functionality provides potent inhibition of all four subclasses of the Zn(2+) -dependent HDACs. Potent inhibition was observed with two different scaffolds, demonstrating the efficiency of the trifluoromethyl ketone moiety as a zinc binding motif. Interestingly, we also identified silanediol as a zinc binding group with potential for future development of non-hydroxamate class I and class IIb HDAC inhibitors. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Aspergillus fumigatus (Af) Hydroxamate Siderophores Protect Formation of Af Biofilms from the Pseudomonas aeruginosa (Pa) Product Pyoverdine

PubMed Central

Sass, Gabriele; Stevens, David A

2017-01-01

Abstract Background Pa and Af are pathogens frequently found together in airways of immunocompromised patients and patients with cystic fibrosis (CF). Hence, interactions of Pa and Af require understanding. Both Pa and Af are crucially dependent on the availability of iron, and therefore are competitors in their microenvironment. We have shown, using deletion mutants of Pa, that the Pa siderophore pyoverdine, the dominant Pa inhibitor of Af, interferes with Af biofilms by iron chelation, and denial of iron to the fungus. Methods Protective compounds in Af supernatants were evaluated using assays for the quantification of Af biofilm metabolism by XTT measurement, spectrometric pyoverdine measurement, as well as Chrome Azorole S (CAS) assay for the determination of siderophore production. Results Here we provide evidence that whereas iron usage by Af promotes pyoverdine production by Pa, Af has developed a defense mechanism against anti-fungal pyoverdine effects. The ability of Af to produce hydroxamate siderophores, and shed these into the surrounding medium, where they sequester and transport iron, is a key factor for Af self-defense against Pa. Under low iron conditions, such as in the presence of high amounts of the Pa siderophore pyoverdine, siderophore-bound iron is then fed to Af, protecting the fungus from iron starvation. Af with a deletion mutation in sidA, a gene essential for the production of hydroxamate siderophores, was significantly more sensitive to Pa supernatants, as well as pure pyoverdine, than wild-type Af. Af supernatants, produced in the presence of celastrol, an inhibitor of SidA-generated biosynthesis of siderophores, or produced by the sidA mutant, were not able to protect Af from iron starvation. Conclusion Interference with the iron-dependent Af self-defense mechanism might represent a new approach for therapy against aspergillosis. Disclosures All authors: No reported disclosures.

HDACi Valproic Acid (VPA) and Suberoylanilide Hydroxamic Acid (SAHA) Delay but Fail to Protect against Warm Hepatic Ischemia-Reperfusion Injury.

PubMed

Ruess, Dietrich A; Probst, Moriz; Marjanovic, Goran; Wittel, Uwe A; Hopt, Ulrich T; Keck, Tobias; Bausch, Dirk

2016-01-01

Histone deacetylases (HDAC) catalyze N-terminal deacetylation of lysine-residues on histones and multiple nuclear and cytoplasmic proteins. In various animal models, such as trauma/hemorrhagic shock, ischemic stroke or myocardial infarction, HDAC inhibitor (HDACi) application is cyto- and organoprotective and promotes survival. HDACi reduce stress signaling, cell death and inflammation. Hepatic ischemia-reperfusion (I/R) injury during major liver resection or transplantation increases morbidity and mortality. Assuming protective properties, the aim of this study was to investigate the effect of the HDACi VPA and SAHA on warm hepatic I/R. Male Wistar-Kyoto rats (age: 6-8 weeks) were randomized to VPA, SAHA, vehicle control (pre-) treatment or sham-groups and underwent partial no-flow liver ischemia for 90 minutes with subsequent reperfusion for 6, 12, 24 and 60 hours. Injury and regeneration was quantified by serum AST and ALT levels, by macroscopic aspect and (immuno-) histology. HDACi treatment efficiency, impact on MAPK/SAPK-activation and Hippo-YAP signaling was determined by Western blot. Treatment with HDACi significantly enhanced hyperacetylation of Histone H3-K9 during I/R, indicative of adequate treatment efficiency. Liver injury, as measured by macroscopic aspect, serum transaminases and histology, was delayed, but not alleviated in VPA and SAHA treated animals. Importantly, tissue destruction was significantly more pronounced with VPA. SAPK-activation (p38 and JNK) was reduced by VPA and SAHA in the early (6h) reperfusion phase, but augmented later on (JNK, 24h). Regeneration appeared enhanced in SAHA and VPA treated animals and was dependent on Hippo-YAP signaling. VPA and SAHA delay warm hepatic I/R injury at least in part through modulation of SAPK-activation. However, these HDACi fail to exert organoprotective effects, in this setting. For VPA, belated damage is even aggravated.

Gaseous signalling molecule SO2 via Hippo-MST pathway to improve myocardial fibrosis of diabetic rats

PubMed Central

Liu, Maojun; Liu, Shengquan; Tan, Wenting; Tang, Fen; Long, Junrong; Li, Zining; Liang, Biao; Chu, Chun; Yang, Jun

2017-01-01

Recent studies have indicated the existence of an endogenous sulfur dioxide (SO2)-generating system in the cardiovascular system. The present study aimed to discuss the function and regulatory mechanism of gaseous signal molecule SO2 in inhibiting apoptosis and endoplasmic reticulum stress (ERS) via the Hippo-MST signaling pathway to improve myocardial fibrosis of diabetic rats. A total of 40 male Sprague-Dawley rats were randomly divided into four groups (10 rats per group): Normal control group (control group), diabetic rats group [streptozotocin (STZ) group], SO2 intervention group (STZ+SO2 group) and diabetes mellitus rats treated with L-Aspartic acid β-hydroxamate (HDX) group (HDX group). Diabetic rats models were established by intra-peritoneal injection of STZ (40 mg/kg) Following model establishment, intra-peritoneal injection of Na2SO3/NaHSO3 solution (0.54 mmol/kg) was administered in the STZ+SO2 group, and HDX solution (25 mg/kg/week) was administered in the HDX group. A total of 4 weeks later, echocardiography was performed to evaluate rats' cardiac function; Masson staining, terminal deoxynucleotidyl transferase dUTP nick end labeling staining and transmission electron microscopy examinations were performed to observe myocardial morphological changes. ELISA was employed to determine the SO2 content. Western blot analysis was performed to detect the expression of proteins associated with apoptosis, ERS and the Hippo-MST signalling pathway. Compared with the control group, the STZ group and HDX group had a disordered arrangement of myocardial cells with apparent myocardial fibrosis, and echocardiography indicated that the cardiac function was lowered, there was an obvious increase of apoptosis in myocardial tissue, the expression levels of apoptosis-associated protein B-cell lymphoma associated protein X, caspase-3 and caspase-9 were upregulated, and Bcl-2 expression was downregulated. The expression of ERS and Hippo-MST pathway-associated proteins, including CHOP, GRP94, MST1 and MST2, were significantly upregulated. By contrast, these above-mentioned changes were reversed by SO2 treatment. Compared with STZ group, the HDX group had a further increase of myocardial fibrosis and apoptosis, while there were no statistically significant differences in the expression of Bax/Bcl-2, caspase-3, caspase-9 and ERS and Hippo-MST pathway-associated proteins. The results of the present study demonstrated that the gaseous signal molecule SO2 can effectively improve the myocardial fibrosis of diabetic rats, and its mechanism may be associated with reduced apoptosis and ERS by downregulated Hippo-MST pathway. PMID:28990064

Gaseous signalling molecule SO2 via Hippo‑MST pathway to improve myocardial fibrosis of diabetic rats.

PubMed

Liu, Maojun; Liu, Shengquan; Tan, Wenting; Tang, Fen; Long, Junrong; Li, Zining; Liang, Biao; Chu, Chun; Yang, Jun

2017-12-01

Recent studies have indicated the existence of an endogenous sulfur dioxide (SO2)‑generating system in the cardiovascular system. The present study aimed to discuss the function and regulatory mechanism of gaseous signal molecule SO2 in inhibiting apoptosis and endoplasmic reticulum stress (ERS) via the Hippo‑MST signaling pathway to improve myocardial fibrosis of diabetic rats. A total of 40 male Sprague‑Dawley rats were randomly divided into four groups (10 rats per group): Normal control group (control group), diabetic rats group [streptozotocin (STZ) group], SO2 intervention group (STZ+SO2 group) and diabetes mellitus rats treated with L‑Aspartic acid β‑hydroxamate (HDX) group (HDX group). Diabetic rats models were established by intra‑peritoneal injection of STZ (40 mg/kg) Following model establishment, intra‑peritoneal injection of Na2SO3/NaHSO3 solution (0.54 mmol/kg) was administered in the STZ+SO2 group, and HDX solution (25 mg/kg/week) was administered in the HDX group. A total of 4 weeks later, echocardiography was performed to evaluate rats' cardiac function; Masson staining, terminal deoxynucleotidyl transferase dUTP nick end labeling staining and transmission electron microscopy examinations were performed to observe myocardial morphological changes. ELISA was employed to determine the SO2 content. Western blot analysis was performed to detect the expression of proteins associated with apoptosis, ERS and the Hippo‑MST signalling pathway. Compared with the control group, the STZ group and HDX group had a disordered arrangement of myocardial cells with apparent myocardial fibrosis, and echocardiography indicated that the cardiac function was lowered, there was an obvious increase of apoptosis in myocardial tissue, the expression levels of apoptosis‑associated protein B‑cell lymphoma associated protein X, caspase‑3 and caspase‑9 were upregulated, and Bcl‑2 expression was downregulated. The expression of ERS and Hippo‑MST pathway‑associated proteins, including CHOP, GRP94, MST1 and MST2, were significantly upregulated. By contrast, these above‑mentioned changes were reversed by SO2 treatment. Compared with STZ group, the HDX group had a further increase of myocardial fibrosis and apoptosis, while there were no statistically significant differences in the expression of Bax/Bcl‑2, caspase‑3, caspase‑9 and ERS and Hippo‑MST pathway‑associated proteins. The results of the present study demonstrated that the gaseous signal molecule SO2 can effectively improve the myocardial fibrosis of diabetic rats, and its mechanism may be associated with reduced apoptosis and ERS by downregulated Hippo‑MST pathway.

Epigenetic regulation of opioid-induced hyperalgesia, dependence, and tolerance in mice.

PubMed

Liang, De-Yong; Li, XiangQi; Clark, J David

2013-01-01

Repeated administration of opioids such as morphine induces persistent behavioral changes including opioid-induced hyperalgesia (OIH), tolerance, and physical dependence. In the current work we explored how the balance of histone acetyltransferase (HAT) versus histone deacetylase (HDAC) might regulate these morphine-induced changes. Nociceptive thresholds, analgesia, and physical dependence were assessed during and for a period of several weeks after morphine exposure. To probe the roles of histone acetylation, the HAT inhibitor curcumin or a selective HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) was administered daily to groups of animals. Histone acetylation in spinal cord was assessed by Western blot and immunohistochemistry. Concurrent administration of curcumin with morphine for 4 days significantly reduced development of opioid-induced mechanical allodynia, thermal hyperalgesia, tolerance, and physical dependence. Conversely, the HDAC inhibitor SAHA enhanced these responses. Interestingly, SAHA treatment after the termination of opioid administration sustained these behavioral changes for at least 4 weeks. Histone H3 acetylation in the dorsal horn of the spinal cord was increased after chronic morphine treatment, but H4 acetylation was unchanged. Moreover, we observed a decrease in HDAC activity in the spinal cords of morphine-treated mice while overall HAT activity was unchanged, suggesting a shift toward a state of enhanced histone acetylation. The current study indicates that epigenetic mechanisms play a crucial role in opioid-induced long-lasting neuroplasticity. These results provide new sight into understanding the mechanisms of opioid-induced neuroplasticity and suggest new strategies to limit opioid abuse potential and increase the value of these drugs as analgesics. Copyright © 2013 American Pain Society. All rights reserved.

Cortisol inhibits CSF2 and CSF3 via DNA methylation and inhibits invasion in first-trimester trophoblast cells

PubMed Central

Smith, Arianna; Witte, Elizabeth; McGee, Devin; Knott, Jason; Narang, Kavita; Racicot, Karen

2018-01-01

Problem Heightened maternal stress affects trophoblast function and increases risk for adverse pregnancy outcomes. Methods of Study Studies were performed using the first-trimester trophoblast cell line, Sw.71. Cytokines were quantified using qPCR and ELISA. Epigenetic regulation of cytokines was characterized by inhibiting histone deacetylation (1 μmol/L suberoylanilide hydroxamic acid [SAHA]) or methylation (5 μmol/L 5-azacytidine), or with chromatin immunoprecipitation (ChIP) with a pan-acetyl histone-3 antibody. Invasion assays used Matrigel chambers. Results Cortisol inhibited expression of CSF2 (GM-CSF) and CSF3 (G-CSF) in trophoblast cells. Cortisol-associated inhibition was dependent on DNA methylation and was not affected by acetylation. There was also a modest decrease in trophoblast invasion, not dependent on loss of CSFs. Conclusion In first-trimester trophoblast cells, the physiological glucocorticoid, cortisol, inhibited two cytokines with roles in placental development and decreased trophoblast invasion. Cortisol-associated changes in trophoblast function could increase the risk for immune-mediated abortion or other adverse pregnancy outcomes. PMID:28846166

Intramolecular Diels-Alder Reaction of N-Alkyl-2-cyano-1-azadienes: A Study of the Eschenmoser Cycloreversion of Dihydrooxazines as a Route to N-Alkyl-2-cyano-1-azadienes.

PubMed

Motorina, Irina A.; Fowler, Frank W.; Grierson, David S.

1997-04-04

In connection with the development of the intramolecular Diels-Alder reaction (IMDA) of 1-azadienes, the 5,6-dihydro-4H-1,2-oxazine 12has been evaluated as a synthon equivalent of the 2-cyano-1-azadiene system. It was found that the dihydrooxazonium salt 27, generated in situ from the cyclic hydroxamic acid derivative 26, is converted directly to azadiene 4a via tautomerization to the corresponding enamine and a particularly facile Eschenmoser type cycloreversion process. Conditions were subsequently found for the preparation of synthon 12. N-Alkylation of this intermediate with alkyl bromides in the presence of Ag(+) ion also resulted in direct formation of the 2-cyano-1-azadiene products 38a-dand 4a. Microwave irradiation of a benzene solution of azadiene 4a proved to be a convenient means to effect its IMDA conversion to indolizidine 5a. To avoid decomposition of azadiene 38c, its intramolecular cycloaddition giving 40 (60%) was achieved by flash vacuum thermolysis.

Neutrophil activator of matrix metalloproteinase-2 (NAM).

PubMed

Rollo, Ellen E; Hymowitz, Michelle; Schmidt, Cathleen E; Montana, Steve; Foda, Hussein; Zucker, Stanley

2006-01-01

We have isolated a novel soluble factor(s), neutrophil activator of matrix metalloproteinases (NAM), secreted by unstimulated normal human peripheral blood neutrophils that causes the activation of cell secreted promatrix metalloproteinase-2 (proMMP-2). Partially purified preparations of NAM have been isolated from the conditioned media of neutrophils employing gelatin-Sepharose chromatography and differential membrane filter centrifugation. NAM activity, as assessed by exposing primary human umbilical vein endothelial cells (HUVEC) or HT1080 cells to NAM followed by gelatin zymography, was seen within one hour. Tissue inhibitor of metalloproteinase-2 (TIMP-2) and hydroxamic acid derived inhibitors of MMPs (CT1746 and BB94) abrogated the activation of proMMP-2 by NAM, while inhibitors of serine and cysteine proteases showed no effect. NAM also produced an increase in TIMP-2 binding to HUVEC and HT1080 cell surfaces that was inhibited by TIMP-2, CT1746, and BB94. Time-dependent increases in MT1-MMP protein and mRNA were seen following the addition of NAM to cells. These data support a role for NAM in cancer dissemination.

The clinical development of histone deacetylase inhibitors as targeted anticancer drugs.

PubMed

Marks, Paul A

2010-09-01

Histone deacetylase (HDAC) inhibitors are being developed as a new, targeted class of anticancer drugs. This review focuses on the mechanisms of action of the HDAC inhibitors, which selectively induce cancer cell death. There are 11 zinc-dependent HDACs in humans and the biological roles of these lysine deacetylases are not completely understood. It is clear that these different HDACs are not redundant in their activity. This review focuses on the mechanisms by which HDAC inhibitors can induce transformed cell growth arrest and cell death, inhibit cell mobility and have antiangiogenesis activity. There are more than a dozen HDAC inhibitors, including hydroxamates, cyclic peptides, benzamides and fatty acids, in various stages of clinical trials and many more compounds in preclinical development. The chemically different HDAC inhibitors may target different HDACs. There are extensive preclinical studies with transformed cells in culture and tumor-bearing animal models, as well as limited clinical studies reported to date, which indicate that HDAC inhibitors will be most useful when used in combination with cytotoxic or other targeted anticancer agents.

Identification of small-molecule antagonists of the Pseudomonas aeruginosa transcriptional regulator PqsR: biophysically guided hit discovery and optimization.

PubMed

Klein, Tobias; Henn, Claudia; de Jong, Johannes C; Zimmer, Christina; Kirsch, Benjamin; Maurer, Christine K; Pistorius, Dominik; Müller, Rolf; Steinbach, Anke; Hartmann, Rolf W

2012-09-21

The Gram-negative pathogen Pseudomonas aeruginosa produces an intercellular alkyl quinolone signaling molecule, the Pseudomonas quinolone signal. The pqs quorum sensing communication system that is characteristic for P. aeruginosa regulates the production of virulence factors. Therefore, we consider the pqs system a novel target to limit P. aeruginosa pathogenicity. Here, we present small molecules targeting a key player of the pqs system, PqsR. A rational design strategy in combination with surface plasmon resonance biosensor analysis led to the identification of PqsR binders. Determination of thermodynamic binding signatures and functional characterization in E. coli guided the hit optimization, resulting in the potent hydroxamic acid derived PqsR antagonist 11 (IC(50) = 12.5 μM). Remarkably it displayed a comparable potency in P. aeruginosa (IC(50) = 23.6 μM) and reduced the production of the virulence factor pyocyanin. Beyond this, site-directed mutagenesis together with thermodynamic analysis provided insights into the energetic characteristics of protein-ligand interactions. Thus the identified PqsR antagonists are promising scaffolds for further drug design efforts against this important pathogen.

Histone deacetylase inhibitors protect against cisplatin-induced acute kidney injury by activating autophagy in proximal tubular cells.

PubMed

Liu, Jing; Livingston, Man J; Dong, Guie; Tang, Chengyuan; Su, Yunchao; Wu, Guangyu; Yin, Xiao-Ming; Dong, Zheng

2018-02-23

Histone deacetylase inhibitors (HDACi) have therapeutic effects in models of various renal diseases including acute kidney injury (AKI); however, the underlying mechanism remains unclear. Here we demonstrate that two widely tested HDACi (suberoylanilide hydroxamic acid (SAHA) and trichostatin A (TSA)) protect the kidneys in cisplatin-induced AKI by enhancing autophagy. In cultured renal proximal tubular cells, SAHA and TSA enhanced autophagy during cisplatin treatment. We further verified the protective effect of TSA against cisplatin-induced apoptosis in these cells. Notably, inhibition of autophagy by chloroquine or by autophagy gene 7 (Atg7) ablation diminished the protective effect of TSA. In mice, TSA increased autophagy in renal proximal tubules and protected against cisplatin-induced AKI. The in vivo effect of TSA was also abolished by chloroquine and by Atg7 knockout specifically from renal proximal tubules. Mechanistically, TSA stimulated AMPK and inactivated mTOR during cisplatin treatment of proximal tubule cells and kidneys in mice. Together, these results suggest that HDACi may protect kidneys by activating autophagy in proximal tubular cells.

Immunomodulatory effects of histone deacetylase inhibitors.

PubMed

Licciardi, P V; Ververis, K; Tang, M L; El-Osta, A; Karagiannis, T C

2013-05-01

Histone deacetylase inhibitors (HDACi) have emerged as a new generation of anticancer therapeutics. The classical broad-spectrum HDACi typically alter the cell cycle distribution and induce cell death, apoptosis and differentiation in malignant and transformed cells. This provides the basis for the clinical potential of HDACi in cancer therapy. Currently two compounds, suberoylanilide hydroxamic acid (SAHA, Vorinostat, Zolinza™) and depsipeptide (Romidepsin, Istodax™) have been approved for by the US Food and Drug Administration for the treatment of refractory cutaneous T-cell lymphoma. Apart from clinical application in oncology, HDACi have also been investigated as potential therapeutics for various pathologies including those of the central nervous system (such as Huntington's disease and multiple sclerosis), cardiac conditions (particularly hypertrophy), arthritis and malaria. Further, evidence is accumulating for potent immunomodulatory effects of classical HDACi which is the focus of this review. We review the antiinflammatory effects of HDACi and in particular findings implicating regulation of the innate and adaptive immune systems by HDAC enzymes. The recent findings highlighting the immunomodulatory function of HDAC11 which relates to balancing immune activation versus tolerance are also discussed.

Study on separation of minor actinides from HLLW with new extractant of TODGA-DHOA/Kerosene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ye, Guo-an; Zhu, Wen-bin; Li, Feng-feng

2013-07-01

The extraction behavior of U, Np, Pu, Am, rare earth elements and Sr from nitric acid solutions by TODGA/dodecan, DHOA/dodecane and TODGA-DHOA/dodecane were investigated, respectively. Based on experimental results, a separation process was proposed for minor actinide isolation from high level liquid waste (HLLW): the TODGA-DHOA/kerosene system. The multi-stage counter-current cascade experiments were carried out for the purpose by 0.1 mol/l TODGA-1.0 mol/l DHOA/kerosene with miniature mixer- settler contactor rigs (8 stages for extraction, 6 stages for scrubbing, 8 stages for first stripping, 8 stages for second stripping). The results show that the recovery efficiencies of the actinides and lanthanidesmore » are more than 99.9%, whereas less than 1% Sr was extracted by 0.1 mol/l TODGA - 1.0 mol/l DHOA/kerosene. The stripping efficiencies of U, Np and Pu are more than 95% in the first stripping step by 0.5 mol/l HNO{sub 3} + 0.5 mol/l AHA(aceto-hydroxamic acid), all of the remained actinides and lanthanides can be stripped by 0.01 mol/l HNO{sub 3} in the second stripping step. 99% Sr was extracted by 0.1 mol/l TODGA/kerosene, so Sr can be recovered efficiently directly from the raffinate by 0.1 mol/l TODGA/kerosene. (authors)« less

Comparison of macrocyclic and acyclic chelators for gallium-68 radiolabelling.

PubMed

Tsionou, Maria Iris; Knapp, Caroline E; Foley, Calum A; Munteanu, Catherine R; Cakebread, Andrew; Imberti, Cinzia; Eykyn, Thomas R; Young, Jennifer D; Paterson, Brett M; Blower, Philip J; Ma, Michelle T

2017-10-24

Gallium-68 ( 68 Ga) is a positron-emitting isotope used for clinical PET imaging of peptide receptor expression. 68 Ga radiopharmaceuticals used in molecular PET imaging consist of disease-targeting biomolecules tethered to chelators that complex 68 Ga 3+ . Ideally, the chelator will rapidly, quantitatively and stably coordinate 68 Ga 3+ at room temperature, near neutral pH and low chelator concentration, allowing for simple routine radiopharmaceutical formulation. Identification of chelators that fulfil these requirements will facilitate development of kit-based 68 Ga radiopharmaceuticals. Herein the reaction of a range of widely used macrocyclic and acyclic chelators with 68 Ga 3+ is reported. Radiochemical yields have been measured under conditions of varying chelator concentrations, pH (3.5 and 6.5) and temperature (25 and 90 °C). These chelators are: 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA), 1,4,7-triazacyclononane macrocycles substituted with phosphonic (NOTP) and phosphinic (TRAP) groups at the amine, bis(2-hydroxybenzyl)ethylenediaminediacetic acid (HBED), a tris(hydroxypyridinone) containing three 1,6-dimethyl-3-hydroxypyridin-4-one groups (THP) and the hexadentate tris(hydroxamate) siderophore desferrioxamine-B (DFO). Competition studies have also been undertaken to assess relative complexation efficiencies of each chelator for 68 Ga 3+ under different pH and temperature conditions. Performing radiolabelling reactions at pH 6.5, 25 °C and 5-50 μM chelator concentration resulted in near quantitative radiochemical yields for all chelators, except DOTA. Radiochemical yields either decreased or were not substantially improved when the reactions were undertaken at lower pH or at higher temperature, except in the case of DOTA. THP and DFO were the most effective 68 Ga 3+ chelators at near-neutral pH and 25 °C, rapidly providing near-quantitative radiochemical yields at very low chelator concentrations. NOTP and HBED were only slightly less effective under these conditions. In competition studies with all other chelators, THP demonstrated highest reactivity for 68 Ga 3+ complexation under all conditions. These data point to THP possessing ideal properties for rapid, one-step kit-based syntheses of 68 Ga-biomolecules for molecular PET imaging. LC-MS and 1 H, 13 C{ 1 H} and 71 Ga NMR studies of HBED complexes of Ga 3+ showed that under the analytical conditions employed in this study, multiple HBED-bound Ga complexes exist. X-ray diffraction data indicated that crystals isolated from these solutions contained octahedral [Ga(HBED)(H 2 O)], with HBED coordinated in a pentadentate N 2 O 3 mode, with only one phenolic group coordinated to Ga 3+ , and the remaining coordination site occupied by a water molecule.

Vorinostat with Sustained Exposure and High Solubility in Poly(ethylene glycol)-b-poly(DL-lactic acid) Micelle Nanocarriers: Characterization and Effects on Pharmacokinetics in Rat Serum and Urine

PubMed Central

Mohamed, Elham A.; Zhao, Yunqi; Meshali, Mahasen M.; Remsberg, Connie M.; Borg, Thanaa M.; Foda, Abdel Monem M.; Takemoto, Jody K.; Sayre, Casey; Martinez, Stephanie; Davies, Neal M.; Forrest, M. Laird

2015-01-01

The histone deacetylase inhibitor suberoylanilide hydroxamic acid, known as vorinostat, is a promising anti-cancer drug with a unique mode of action; however, it is plagued by low water solubility, low permeability, and suboptimal pharmacokinetics. In this study, poly(ethylene glycol)-b-poly(DL-lactic acid) (PEG-b-PLA) micelles of vorinostat were developed. Vorinostat’s pharmacokinetics in rats were investigated after intravenous (i.v.) (10 mg/kg) and oral (50 mg/kg) micellar administrations and compared to a conventional PEG400 solution and methylcellulose suspension. The micelles increased the aqueous solubility of vorinostat from 0.2 mg/ml to 8.15 ± 0.60 mg/ml and 10.24 ± 0.92 mg/ml at drug to nanocarrier ratios of 1:10 and 1:15, respectively. Micelles had nanoscopic mean diameters of 75.67 ± 7.57 nm and 87.33 ± 8.62 nm for 1:10 and 1:15 micelles, respectively, with drug loading capacities of 9.93 ± 0.21% and 6.91 ± 1.19 %, and encapsulation efficiencies of 42.74 ± 1.67% and 73.29 ± 4.78%, respectively. The micelles provided sustained exposure and improved pharmacokinetics characterized by a significant increase in serum half-life, area under curve, and mean residence time. The micelles reduced vorinostat clearance particularly after i.v. dosing. Thus, PEG-b-PLA micelles significantly improved the oral and intravenous pharmacokinetics and bioavailability of vorinostat, which warrants further investigation. PMID:22806441

Vorinostat with sustained exposure and high solubility in poly(ethylene glycol)-b-poly(DL-lactic acid) micelle nanocarriers: characterization and effects on pharmacokinetics in rat serum and urine.

PubMed

Mohamed, Elham A; Zhao, Yunqi; Meshali, Mahasen M; Remsberg, Connie M; Borg, Thanaa M; Foda, Abdel Monem M; Takemoto, Jody K; Sayre, Casey L; Martinez, Stephanie E; Davies, Neal M; Forrest, M Laird

2012-10-01

The histone deacetylase inhibitor suberoylanilide hydroxamic acid, known as vorinostat, is a promising anticancer drug with a unique mode of action; however, it is plagued by low water solubility, low permeability, and suboptimal pharmacokinetics. In this study, poly(ethylene glycol)-b-poly(DL-lactic acid) (PEG-b-PLA) micelles of vorinostat were developed. Vorinostat's pharmacokinetics in rats was investigated after intravenous (i.v.) (10 mg/kg) and oral (p.o.) (50 mg/kg) micellar administrations and compared with a conventional polyethylene glycol 400 solution and methylcellulose suspension. The micelles increased the aqueous solubility of vorinostat from 0.2 to 8.15 ± 0.60 and 10.24 ± 0.92 mg/mL at drug to nanocarrier ratios of 1:10 and 1:15, respectively. Micelles had nanoscopic mean diameters of 75.67 ± 7.57 and 87.33 ± 8.62 nm for 1:10 and 1:15 micelles, respectively, with drug loading capacities of 9.93 ± 0.21% and 6.91 ± 1.19%, and encapsulation efficiencies of 42.74 ± 1.67% and 73.29 ± 4.78%, respectively. The micelles provided sustained exposure and improved pharmacokinetics characterized by a significant increase in serum half-life, area under curve, and mean residence time. The micelles reduced vorinostat clearance particularly after i.v. dosing. Thus, PEG-b-PLA micelles significantly improved the p.o. and i.v. pharmacokinetics and bioavailability of vorinostat, which warrants further investigation. Copyright © 2012 Wiley Periodicals, Inc.

Crystal Structure Analyses of the Fosmidomycin-Target Enzyme from Plasmodium Falciparum

NASA Astrophysics Data System (ADS)

Umeda, Tomonobu; Kusakabe, Yoshio; Tanaka, Nobutada

The human malaria parasite Plasmodium falciparum is responsible for the death of more than a million people each year. Fosmidomycin has proved to be efficient in the treatment of P. falciparum malaria through the inhibition of 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR), an enzyme of the non-mevalonate pathway of isoprenoid biosynthesis, which is absent in humans. Crystal structure analyses of P. falciparum DXR (PfDXR) revealed that (i) an intrinsic flexibility of the PfDXR molecule accounts for the induced-fit movement to accommodate the bound inhibitor in the active site, and (ii) a cis arrangement of the oxygen atoms of the hydroxamate group of the bound inhibitor is essential for tight binding of the inhibitor to the active site metal. We believe that our study will serve as a useful guide to develop more potent PfDXR inhibitors.

Histone Deacetylase Inhibitors: A Novel Therapeutic Weapon Against Medullary Thyroid Cancer?

PubMed

Damaskos, Christos; Garmpis, Nikolaos; Valsami, Serena; Spartalis, Eleftherios; Antoniou, Efstathios A; Tomos, Periklis; Karamaroudis, Stefanos; Zoumpou, Theofano; Pergialiotis, Vasilios; Stergios, Konstantinos; Michaelides, Constantinos; Kontzoglou, Konstantinos; Perrea, Despina; Nikiteas, Nikolaos; Dimitroulis, Dimitrios

2016-10-01

Medullary thyroid cancer (MTC) is highly malignant, metastatic and recurrent, remaining generally incurable, and responsible for approximately 14% of all thyroid carcinoma-related deaths. MTC can metastasize to lymph nodes, trachea and distant organs, such as brain, lungs, liver and bones. MTC cells are resistant to chemotherapy and traditional external therapies are not showing definite clinical benefits. Scientists are trying to understand the molecular background of carcinogenesis and histone deacetylase (HDAC) seems to play a potential role to gene transcription. On the other hand, HDAC inhibitors (HDACI) hamper the HDAC action giving promising results as new anticancer drugs. The purpose of this review was to evaluate the current status of research considering the role of HDACIs in MTC treatment and to present the latest trends in MTC treatment protocols. This literature review was accomplished using the MEDLINE database. The key words/phrases were; HDACI, medullary thyroid cancer, HDACI in the therapy of neuroendocrine tumors, HDACI in MTC. Forty-one articles were selected from the total number of the search's results. Only sixteen papers focus on the use of HDACIs in the treatment of MTC. In order to extract our conclusions, we took into account some studies whose main topic does not strictly refer to the MTC but they contain noteworthy and useful information. Only English articles published up to August 2016 were assessed and used for writing this review. Molecules, such as valproid acid (VPA), vorinostat, suberoyl bis-hydroxamic acid (SBHA), depsipeptide, belinostat, m-carboxycinnamic acid bis-hydroxamine (CBHA) and AB3 have shown promising antitumor effects against MTC. HDACIs represent a promising field for targeted therapy both for its anticancer properties, as well as for augmenting radiotherapeutic modalities. More trials are needed. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Iron acquisition by Haemophilus influenzae.

PubMed Central

Pidcock, K A; Wooten, J A; Daley, B A; Stull, T L

1988-01-01

The mechanisms for acquisition of iron by Haemophilus influenzae and their role in pathogenesis are not known. Heme and nonheme sources of iron were evaluated for their effect on growth of type b and nontypable strains of H. influenzae in an iron-restricted, defined medium. All 13 strains acquired iron from heme, hemoglobin, hemoglobin-haptoglobin, and heme-hemopexin. Among nonheme sources of protein-bound iron, growth of H. influenzae was enhanced by partially saturated human transferrin but not by lactoferrin or ferritin. Purified ferrienterochelin and ferridesferrioxamine failed to provide iron to H. influenzae, and the supernatants of H. influenzae E1a grown in iron-restricted medium failed to enhance iron-restricted growth of siderophore-dependent strains of Escherichia coli, Salmonella typhimurium, and Arthrobacter terregens. Marked alterations in the profile of outer membrane proteins of H. influenzae were observed when the level of free iron was varied between 1 microM and 1 mM. Catechols were not detected in the supernatants of strain E1a; however, iron-related hydroxamate production was detected by two biochemical assays. We conclude that the sources of iron for H. influenzae are diverse. The significance of hydroxamate production and iron-related outer membrane proteins to H. influenzae iron acquisition is not yet clear. Images PMID:2964410

New hydroxamate inhibitors of neurotensin-degrading enzymes. Synthesis and enzyme active-site recognition.

PubMed

Bourdel, E; Doulut, S; Jarretou, G; Labbe-Jullie, C; Fehrentz, J A; Doumbia, O; Kitabgi, P; Martinez, J

1996-08-01

Selective and mixed inhibitors of the three zinc metallopeptidases that degrade neurotensin (NT), e.g. endopeptidase 24-16 (EC 3.4.24.16), endopeptidase 24-11 (EC 3.4.24.11 or neutral endopeptidase, NEP) and endopeptidase 24-15 (EC 3.4.24.15), and leucine-aminopeptidase (type IV-S), that degrades the NT-related peptides, Neuromedin N (NN), are of great interest. On the structural basis of compound JMV 390-1 (N-[3-[(hydroxyamino)carbonyl]-1-oxo-2(R)-benzylpropyl]-L- isoleucyl-L-leucine), which was a full inhibitor of the major NT degrading enzymes, several hydroxamate inhibitors corresponding to the general formula HONHCO-CH2-CH(CH2-C6H5)CO-X-Y-OH (with X-Y = dipeptide) have been synthesized. Compound 7a (X-Y = Ile-Ala) was nearly 40-times more potent in inhibiting EC 24-16 than NEP and more than 800-times more potent than EC 24-15, with an IC50 (12 nM) almost equivalent to that of compound JMV 390-1. Therefore, this compound is an interesting selective inhibitor of EC 24-16, and should be an interesting probe to explore the physiological involvement of EC 24-16 in the metabolism of neurotensin.

Structural studies of human histone deacetylase 8 and its site-specific variants complexed with substrate and inhibitors.

PubMed

Dowling, Daniel P; Gantt, Stephanie L; Gattis, Samuel G; Fierke, Carol A; Christianson, David W

2008-12-23

Metal-dependent histone deacetylases (HDACs) require Zn(2+) or Fe(2+) to regulate the acetylation of lysine residues in histones and other proteins in eukaryotic cells. Isozyme HDAC8 is perhaps the archetypical member of the class I HDAC family and serves as a paradigm for studying structure-function relationships. Here, we report the structures of HDAC8 complexes with trichostatin A and 3-(1-methyl-4-phenylacetyl-1H-2-pyrrolyl)-N-hydroxy-2-propenamide (APHA) in a new crystal form. The structure of the APHA complex reveals that the hydroxamate CO group accepts a hydrogen bond from Y306 but does not coordinate to Zn(2+) with favorable geometry, perhaps due to the constraints of its extended pi system. Additionally, since APHA binds to only two of the three protein molecules in the asymmetric unit of this complex, the structure of the third monomer represents the first structure of HDAC8 in the unliganded state. Comparison of unliganded and liganded structures illustrates ligand-induced conformational changes in the L2 loop that likely accompany substrate binding and catalysis. Furthermore, these structures, along with those of the D101N, D101E, D101A, and D101L variants, support the proposal that D101 is critical for the function of the L2 loop. However, amino acid substitutions for D101 can also trigger conformational changes of Y111 and W141 that perturb the substrate binding site. Finally, the structure of H143A HDAC8 complexed with an intact acetylated tetrapeptide substrate molecule confirms the importance of D101 for substrate binding and reveals how Y306 and the active site zinc ion together bind and activate the scissile amide linkage of acetyllysine.

Histone deacetylase inhibition blunts ischemia/reperfusion injury by inducing cardiomyocyte autophagy.

PubMed

Xie, Min; Kong, Yongli; Tan, Wei; May, Herman; Battiprolu, Pavan K; Pedrozo, Zully; Wang, Zhao V; Morales, Cyndi; Luo, Xiang; Cho, Geoffrey; Jiang, Nan; Jessen, Michael E; Warner, John J; Lavandero, Sergio; Gillette, Thomas G; Turer, Aslan T; Hill, Joseph A

2014-03-11

Reperfusion accounts for a substantial fraction of the myocardial injury occurring with ischemic heart disease. Yet, no standard therapies are available targeting reperfusion injury. Here, we tested the hypothesis that suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor approved for cancer treatment by the US Food and Drug Administration, will blunt reperfusion injury. Twenty-one rabbits were randomly assigned to 3 groups: (1) vehicle control, (2) SAHA pretreatment (1 day before and at surgery), and (3) SAHA treatment at the time of reperfusion only. Each arm was subjected to ischemia/reperfusion surgery (30 minutes coronary ligation, 24 hours reperfusion). In addition, cultured neonatal and adult rat ventricular cardiomyocytes were subjected to simulated ischemia/reperfusion to probe mechanism. SAHA reduced infarct size and partially rescued systolic function when administered either before surgery (pretreatment) or solely at the time of reperfusion. SAHA plasma concentrations were similar to those achieved in patients with cancer. In the infarct border zone, SAHA increased autophagic flux, assayed in both rabbit myocardium and in mice harboring an RFP-GFP-LC3 transgene. In cultured myocytes subjected to simulated ischemia/reperfusion, SAHA pretreatment reduced cell death by 40%. This reduction in cell death correlated with increased autophagic activity in SAHA-treated cells. RNAi-mediated knockdown of ATG7 and ATG5, essential autophagy proteins, abolished SAHA's cardioprotective effects. The US Food and Drug Administration-approved anticancer histone deacetylase inhibitor, SAHA, reduces myocardial infarct size in a large animal model, even when delivered in the clinically relevant context of reperfusion. The cardioprotective effects of SAHA during ischemia/reperfusion occur, at least in part, through the induction of autophagic flux.

Hydroxamate Production as a High Affinity Iron Acquisition Mechanism in Paracoccidioides Spp

PubMed Central

Silva-Bailão, Mirelle Garcia; Bailão, Elisa Flávia Luiz Cardoso; Lechner, Beatrix Elisabeth; Gauthier, Gregory M.; Lindner, Herbert; Bailão, Alexandre Melo; Haas, Hubertus; de Almeida Soares, Célia Maria

2014-01-01

Iron is a micronutrient required by almost all living organisms, including fungi. Although this metal is abundant, its bioavailability is low either in aerobic environments or within mammalian hosts. As a consequence, pathogenic microorganisms evolved high affinity iron acquisition mechanisms which include the production and uptake of siderophores. Here we investigated the utilization of these molecules by species of the Paracoccidioides genus, the causative agents of a systemic mycosis. It was demonstrated that iron starvation induces the expression of Paracoccidioides ortholog genes for siderophore biosynthesis and transport. Reversed-phase HPLC analysis revealed that the fungus produces and secretes coprogen B, which generates dimerumic acid as a breakdown product. Ferricrocin and ferrichrome C were detected in Paracoccidioides as the intracellular produced siderophores. Moreover, the fungus is also able to grow in presence of siderophores as the only iron sources, demonstrating that beyond producing, Paracoccidioides is also able to utilize siderophores for growth, including the xenosiderophore ferrioxamine. Exposure to exogenous ferrioxamine and dimerumic acid increased fungus survival during co-cultivation with macrophages indicating that these molecules play a role during host-pathogen interaction. Furthermore, cross-feeding experiments revealed that Paracoccidioides siderophores promotes growth of Aspergillus nidulans strain unable to produce these iron chelators. Together, these data denote that synthesis and utilization of siderophores is a mechanism used by Paracoccidioides to surpass iron limitation. As iron paucity is found within the host, siderophore production may be related to fungus pathogenicity. PMID:25157575

The Impact of Chemical Substitutions on Interfacial Properties of REE Orthophosphates (Monazite, Xenotime)

NASA Astrophysics Data System (ADS)

Gamage McEvoy, J.; Thibault, Y.

2016-12-01

Mineral surface properties strongly influence liquid-solid interface behaviour in the presence of various ligands, and can significantly affect processes of natural (ex. fluids, melts) and industrial (ex. oil recovery) relevance. Many Rare Earth Element (REE)-bearing minerals display extensive solid solutions resulting in significant chemical variations which influence their crystal and surface properties and, can consequently impact the interfacial features of their interaction with substances such as organic molecules (i.e. reactivity and sorption). For example, the surface charge properties of some REE orthophosphates show an uncharacteristically wide variation in reported values, where large differences in literature are commonly attributed to compositional differences between samples. However the impact of these chemical substitutions remains largely unknown. As such, the aim of this research was to systematically investigate the influence of mineralogical variation within the compositional space of the REE orthophosphates on their surface chemistry and resulting interaction with organic molecules. To better isolate the chemical, structural, and morphological variables, the synthesis of REE orthophosphate crystals along a number of defined substitutions was conducted, and their surface chemistry characteristics benchmarked against well-characterized natural monazite and xenotime from various localities. The interaction of these crystal surfaces with model organic molecules (long chain carboxylic acids and alkyl hydroxamic acids, respectively) was then studied and characterized via surface (X-ray photoelectron) and near-surface (vibrational) spectroscopic techniques. The implications of crystal surface-organic molecule interactions to mineral processing through flotation were also experimentally investigated.

A Co16 cluster and a 1-D Mn chain complex supported by benzohydroxamic acid.

PubMed

Cao, Yanyuan; Chen, Yanmei; Li, Lei; Gao, Dandan; Liu, Wei; Hu, Hailiang; Li, Wu; Li, Yahong

2013-08-14

The syntheses, crystal structures and magnetic properties are described for a {Co16} cluster [Co(II)16O(OH)2(bha)12(PhCO2)4(Phen)2(MeOH)4]·2MeOH (1) and a 1-D Mn(II) chain complex [Mn(Hbha)2]n·(2MeOH)n (2) (H2bha = benzohydroxamic acid; Phen = 1,10-phenanthroline). The 1 : 1 : 0.5 reaction of Co(O2CMe)2·4H2O, H2bha and 1,10-phenanthroline in MeOH at 100 °C under autogenous pressure gave cluster 1. Complex 2 was obtained from the 1 : 1 reaction mixture of Mn(O2CMe)2·2H2O and H2bha in MeOH under solvothermal conditions. The {Co16} cluster can be thought as a face-centered cube with two wings. The H2bha ligands show hydroximic form in 1 and exhibit hydroxamic mode in 2. The hydroximate ligands in 1 display three distinct binding modes, one of which is novel. Variable-temperature solid-state dc magnetic susceptibility studies have been performed in the 2.0-300 K range for complexes 1 and 2. Antiferromagnetic M(II)···M(II) exchange interactions were found for both 1 and 2. This work also demonstrates that solvothermal method is a potential synthetic approach for the design and growth of high nuclearity clusters or chain complexes of the H2bha ligand.

The HDAC inhibitor SB939 overcomes resistance to BCR-ABL kinase Inhibitors conferred by the BIM deletion polymorphism in chronic myeloid leukemia.

PubMed

Rauzan, Muhammad; Chuah, Charles T H; Ko, Tun Kiat; Ong, S Tiong

2017-01-01

Chronic myeloid leukemia (CML) treatment has been improved by tyrosine kinase inhibitors (TKIs) such as imatinib mesylate (IM) but various factors can cause TKI resistance in patients with CML. One factor which contributes to TKI resistance is a germline intronic deletion polymorphism in the BCL2-like 11 (BIM) gene which impairs the expression of pro-apoptotic splice isoforms of BIM. SB939 (pracinostat) is a hydroxamic acid based HDAC inhibitor with favorable pharmacokinetic, physicochemical and pharmaceutical properties, and we investigated if this drug could overcome BIM deletion polymorphism-induced TKI resistance. We found that SB939 corrects BIM pre-mRNA splicing in CML cells with the BIM deletion polymorphism, and induces apoptotic cell death in CML cell lines and primary cells with the BIM deletion polymorphism. More importantly, SB939 both decreases the viability of CML cell lines and primary CML progenitors with the BIM deletion and restores TKI-sensitivity. Our results demonstrate that SB939 overcomes BIM deletion polymorphism-induced TKI resistance, and suggest that SB939 may be useful in treating CML patients with BIM deletion-associated TKI resistance.

Effects of FR235222, a novel HDAC inhibitor, in proliferation and apoptosis of human leukaemia cell lines: role of annexin A1.

PubMed

Petrella, Antonello; D'Acunto, Cosimo Walter; Rodriquez, Manuela; Festa, Michela; Tosco, Alessandra; Bruno, Ines; Terracciano, Stefania; Taddei, Maurizio; Paloma, Luigi Gomez; Parente, Luca

2008-03-01

FR235222, a novel histone deacetylase inhibitor (HDACi), at 50nM caused accumulation of acetylated histone H4, inhibition of cell proliferation and G1 cycle arrest accompanied by increase of p21 and down-regulation of cyclin E in human promyelocytic leukaemia U937 cells. The compound was also able to increase the protein and mRNA levels of annexin A1 (ANXA1) without effects on apoptosis. Similar effects were observed in human chronic myelogenous leukaemia K562 cells and human T cell leukaemia Jurkat cells. Cycle arrest and ANXA1 expression, without significant effects on apoptosis, were also induced by different HDACi like suberoylanilide hydroxamic acid (SAHA) and trichostatin-A (TSA). FR235222 at 0.5 microM stimulated apoptosis of all leukaemia cell lines associated to an increased expression of the full-length (37kDa) protein and the appearance of a 33kDa N-terminal cleavage product in both cytosol and membrane. These results suggest that ANXA1 expression may mediate cycle arrest induced by low doses FR235222, whereas apoptosis induced by high doses FR235222 is associated to ANXA1 processing.

Rational combination treatment with histone deacetylase inhibitors and immunomodulatory drugs in multiple myeloma.

PubMed

Hideshima, T; Cottini, F; Ohguchi, H; Jakubikova, J; Gorgun, G; Mimura, N; Tai, Y-T; Munshi, N C; Richardson, P G; Anderson, K C

2015-05-15

Immunomodulatory drugs (IMiDs) thalidomide, lenalidomide (Len) and pomalidomide trigger anti-tumor activities in multiple myeloma (MM) by targetting cereblon and thereby impacting IZF1/3, c-Myc and IRF4. Histone deacetylase inhibitors (HDACi) also downregulate c-Myc. We therefore determined whether IMiDs with HDACi trigger significant MM cell growth inhibition by inhibiting or downregulating c-Myc. Combination treatment of Len with non-selective HDACi suberoylanilide hydroxamic acid or class-I HDAC-selective inhibitor MS275 induces synergic cytotoxicity, associated with downregulation of c-Myc. Unexpectedly, we observed that decreased levels of cereblon (CRBN), a primary target protein of IMiDs, was triggered by these agents. Indeed, sequential treatment of MM cells with MS275 followed by Len shows less efficacy than simultaneous treatment with this combination. Importantly ACY1215, an HDAC6 inhibitor with minimal effects on class-I HDACs, together with Len induces synergistic MM cytotoxicity without alteration of CRBN expression. Our results showed that only modest class-I HDAC inhibition is able to induce synergistic MM cytotoxicity in combination with Len. These studies may provide the framework for utilizing HDACi in combination with Len to both avoid CRBN downregulation and enhance anti-MM activities.

Histone Deacetylase Inhibition Promotes Osteoblast Maturation by Altering the Histone H4 Epigenome and Reduces Akt Phosphorylation*

PubMed Central

Dudakovic, Amel; Evans, Jared M.; Li, Ying; Middha, Sumit; McGee-Lawrence, Meghan E.; van Wijnen, Andre J.; Westendorf, Jennifer J.

2013-01-01

Bone has remarkable regenerative capacity, but this ability diminishes during aging. Histone deacetylase inhibitors (HDIs) promote terminal osteoblast differentiation and extracellular matrix production in culture. The epigenetic events altered by HDIs in osteoblasts may hold clues for the development of new anabolic treatments for osteoporosis and other conditions of low bone mass. To assess how HDIs affect the epigenome of committed osteoblasts, MC3T3 cells were treated with suberoylanilide hydroxamic acid (SAHA) and subjected to microarray gene expression profiling and high-throughput ChIP-Seq analysis. As expected, SAHA induced differentiation and matrix calcification of osteoblasts in vitro. ChIP-Seq analysis revealed that SAHA increased histone H4 acetylation genome-wide and in differentially regulated genes, except for the 500 bp upstream of transcriptional start sites. Pathway analysis indicated that SAHA increased the expression of insulin signaling modulators, including Slc9a3r1. SAHA decreased phosphorylation of insulin receptor β, Akt, and the Akt substrate FoxO1, resulting in FoxO1 stabilization. Thus, SAHA induces genome-wide H4 acetylation and modulates the insulin/Akt/FoxO1 signaling axis, whereas it promotes terminal osteoblast differentiation in vitro. PMID:23940046

A Single Sfp-Type Phosphopantetheinyl Transferase Plays a Major Role in the Biosynthesis of PKS and NRPS Derived Metabolites in Streptomyces ambofaciens ATCC23877

PubMed Central

Bunet, Robert; Riclea, Ramona; Laureti, Luisa; Hôtel, Laurence; Paris, Cédric; Girardet, Jean-Michel; Spiteller, Dieter; Dickschat, Jeroen S.; Leblond, Pierre; Aigle, Bertrand

2014-01-01

The phosphopantetheinyl transferases (PPTases) are responsible for the activation of the carrier protein domains of the polyketide synthases (PKS), non ribosomal peptide synthases (NRPS) and fatty acid synthases (FAS). The analysis of the Streptomyces ambofaciens ATCC23877 genome has revealed the presence of four putative PPTase encoding genes. One of these genes appears to be essential and is likely involved in fatty acid biosynthesis. Two other PPTase genes, samT0172 (alpN) and samL0372, are located within a type II PKS gene cluster responsible for the kinamycin production and an hybrid NRPS-PKS cluster involved in antimycin production, respectively, and their products were shown to be specifically involved in the biosynthesis of these secondary metabolites. Surprisingly, the fourth PPTase gene, which is not located within a secondary metabolite gene cluster, appears to play a pleiotropic role. Its product is likely involved in the activation of the acyl- and peptidyl-carrier protein domains within all the other PKS and NRPS complexes encoded by S. ambofaciens. Indeed, the deletion of this gene affects the production of the spiramycin and stambomycin macrolide antibiotics and of the grey spore pigment, all three being PKS-derived metabolites, as well as the production of the nonribosomally produced compounds, the hydroxamate siderophore coelichelin and the pyrrolamide antibiotic congocidine. In addition, this PPTase seems to act in concert with the product of samL0372 to activate the ACP and/or PCP domains of the antimycin biosynthesis cluster which is also responsible for the production of volatile lactones. PMID:24498152

Role of the Fur Regulon in Iron Transport in Bacillus subtilis

PubMed Central

Ollinger, Juliane; Song, Kyung-Bok; Antelmann, Haike; Hecker, Michael; Helmann, John D.

2006-01-01

The Bacillus subtilis ferric uptake regulator (Fur) protein mediates the iron-dependent repression of at least 20 operons encoding ∼40 genes. We investigated the physiological roles of Fur-regulated genes by the construction of null mutations in 14 transcription units known or predicted to function in siderophore biosynthesis or iron uptake. We demonstrate that ywbLMN, encoding an elemental iron uptake system orthologous to the copper oxidase-dependent Fe(III) uptake system of Saccharomyces cerevisiae, is essential for growth in low iron minimal medium lacking citric acid. 2,3-Dihydroxybenzoyl-glycine (Itoic acid), the siderophore precursor produced by laboratory strains of B. subtilis, is of secondary importance. In the presence of citrate, the YfmCDEF ABC transporter is required for optimal growth. B. subtilis is unable to grow in minimal medium containing the iron chelator EDDHA unless the ability to synthesize the intact bacillibactin siderophore is restored (by the introduction of a functional sfp gene) or exogenous siderophores are provided. Utilization of the catecholate siderophores bacillibactin and enterobactin requires the FeuABC importer and the YusV ATPase. Utilization of hydroxamate siderophores requires the FhuBGC ABC transporter together with the FhuD (ferrichrome) or YxeB (ferrioxamine) substrate-binding proteins. Growth with schizokinen or arthrobactin is at least partially dependent on the YfhA YfiYZ importer and the YusV ATPase. We have also investigated the effects of a fur mutation on the proteome and documented the derepression of 11 Fur-regulated proteins, including a newly identified thioredoxin reductase homolog, YcgT. PMID:16672620

Role of the Fur regulon in iron transport in Bacillus subtilis.

PubMed

Ollinger, Juliane; Song, Kyung-Bok; Antelmann, Haike; Hecker, Michael; Helmann, John D

2006-05-01

The Bacillus subtilis ferric uptake regulator (Fur) protein mediates the iron-dependent repression of at least 20 operons encoding approximately 40 genes. We investigated the physiological roles of Fur-regulated genes by the construction of null mutations in 14 transcription units known or predicted to function in siderophore biosynthesis or iron uptake. We demonstrate that ywbLMN, encoding an elemental iron uptake system orthologous to the copper oxidase-dependent Fe(III) uptake system of Saccharomyces cerevisiae, is essential for growth in low iron minimal medium lacking citric acid. 2,3-Dihydroxybenzoyl-glycine (Itoic acid), the siderophore precursor produced by laboratory strains of B. subtilis, is of secondary importance. In the presence of citrate, the YfmCDEF ABC transporter is required for optimal growth. B. subtilis is unable to grow in minimal medium containing the iron chelator EDDHA unless the ability to synthesize the intact bacillibactin siderophore is restored (by the introduction of a functional sfp gene) or exogenous siderophores are provided. Utilization of the catecholate siderophores bacillibactin and enterobactin requires the FeuABC importer and the YusV ATPase. Utilization of hydroxamate siderophores requires the FhuBGC ABC transporter together with the FhuD (ferrichrome) or YxeB (ferrioxamine) substrate-binding proteins. Growth with schizokinen or arthrobactin is at least partially dependent on the YfhA YfiYZ importer and the YusV ATPase. We have also investigated the effects of a fur mutation on the proteome and documented the derepression of 11 Fur-regulated proteins, including a newly identified thioredoxin reductase homolog, YcgT.

Kinetic method for the large-scale analysis of the binding mechanism of histone deacetylase inhibitors.

PubMed

Meyners, Christian; Baud, Matthias G J; Fuchter, Matthew J; Meyer-Almes, Franz-Josef

2014-09-01

Performing kinetic studies on protein ligand interactions provides important information on complex formation and dissociation. Beside kinetic parameters such as association rates and residence times, kinetic experiments also reveal insights into reaction mechanisms. Exploiting intrinsic tryptophan fluorescence a parallelized high-throughput Förster resonance energy transfer (FRET)-based reporter displacement assay with very low protein consumption was developed to enable the large-scale kinetic characterization of the binding of ligands to recombinant human histone deacetylases (HDACs) and a bacterial histone deacetylase-like amidohydrolase (HDAH) from Bordetella/Alcaligenes. For the binding of trichostatin A (TSA), suberoylanilide hydroxamic acid (SAHA), and two other SAHA derivatives to HDAH, two different modes of action, simple one-step binding and a two-step mechanism comprising initial binding and induced fit, were verified. In contrast to HDAH, all compounds bound to human HDAC1, HDAC6, and HDAC8 through a two-step mechanism. A quantitative view on the inhibitor-HDAC systems revealed two types of interaction, fast binding and slow dissociation. We provide arguments for the thesis that the relationship between quantitative kinetic and mechanistic information and chemical structures of compounds will serve as a valuable tool for drug optimization. Copyright © 2014 Elsevier Inc. All rights reserved.

Quinazolin-4-one derivatives as selective histone deacetylase-6 inhibitors for the treatment of Alzheimer's disease.

PubMed

Yu, Chao-Wu; Chang, Pei-Teh; Hsin, Ling-Wei; Chern, Ji-Wang

2013-09-12

Novel quinazolin-4-one derivatives containing a hydroxamic acid moiety were designed and synthesized. All compounds were subjected to histone deacetylase (HDAC) enzymatic assays to identify selective HDAC6 inhibitors with nanomolar IC50 values. (E)-3-(2-Ethyl-7-fluoro-4-oxo-3-phenethyl-3,4-dihydroquinazolin-6-yl)-N-hydroxyacrylamide, 4b, is the most potent HDAC6 inhibitor (IC50, 8 nM). In vitro, these compounds induced neurite outgrowth accompanied by growth-associated protein 43 expression, and they enhanced the synaptic activities of PC12 and SH-SY5Y neuronal cells without producing toxic or mitogenic effects. Several of the compounds dramatically increased nonhistone protein acetylation, specifically of α-tubulin. Some of the more potent HDAC6 inhibitors decreased zinc-mediated β-amyloid aggregation in vitro. N-Hydroxy-3-(2-methyl-4-oxo-3-phenethyl-3,4-dihydro-quinazolin-7-yl)-acrylamide, 3f, the most promising drug candidate, selectively inhibits HDAC6 (IC50, 29 nM), practically does not affect human ether-a-go-go-related membrane channel activity (IC50 >10 μM) or cytochrome P450 activity (IC50 >6.5 μM) in vitro, and significantly improves learning-based performances of mice with β-amyloid-induced hippocampal lesions.

Synergistic effects of combined treatment with histone deacetylase inhibitor suberoylanilide hydroxamic acid and TRAIL on human breast cancer cells

PubMed Central

Zhou, Weiqiang; Feng, Xiuyan; Han Han; Guo, Shanchun; Wang, Guangdi

2016-01-01

Previous studies showed that either histone deacetylase (HDAC) inhibitors or tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can induce apoptosis in tumor cells including breast cancer. However, the underling mechanisms of combining HDAC inhibitors with TRAIL in the treatment of breast cancer are poorly understood. In this study, we determined the ability of SAHA and TRAIL as single agents or in combination to inhibit the growth and survival of MCF-7 and MDA-MB-231 breast cancer cells. Our results demonstrate that the distinct effects of SAHA or TRAIL individually and in combination on the proliferation, cell viability, apoptosis, cell cycle distribution, and morphological changes of MDA-MB-231 and MCF-7 cells. We further determined the different effects of SAHA or TRAIL alone and combining SAHA with TRAIL on the expression of a number of apoptosis-related molecules, cell cycle, growth factors and their receptors in cancer cells. Our results demonstrated that the combinatorial treatment of SAHA and TRAIL may target multiple pathways and serve as an effective therapeutic strategy against breast cancer. An improved understanding of the molecular mechanisms may facilitate either SAHA or TRAIL targeted use and the selection of suitable combinations. PMID:27292433

Combinatorial Treatment of DNA and Chromatin-Modifying Drugs Cause Cell Death in Human and Canine Osteosarcoma Cell Lines

PubMed Central

Thayanithy, Venugopal; Park, ChangWon; Sarver, Aaron L.; Kartha, Reena V.; Korpela, Derek M.; Graef, Ashley J.; Steer, Clifford J.; Modiano, Jaime F.; Subramanian, Subbaya

2012-01-01

Downregulation of microRNAs (miRNAs) at the 14q32 locus stabilizes the expression of cMYC, thus significantly contributing to osteosarcoma (OS) pathobiology. Here, we show that downregulation of 14q32 miRNAs is epigenetically regulated. The predicted promoter regions of miRNA clusters at 14q32 locus showed no recurrent patterns of differential methylation, but Saos2 cells showed elevated histone deacetylase (HDAC) activity. Treatment with 4-phenylbutyrate increased acetylation of histones associated with 14q32 miRNAs, but interestingly, robust restoration of 14q32 miRNA expression, attenuation of cMYC expression, and induction of apoptosis required concomitant treatment with 5-Azacytidine, an inhibitor of DNA methylation. These events were associated with genome-wide gene expression changes including induction of pro-apoptotic genes and downregulation of cell cycle genes. Comparable effects were achieved in human and canine OS cells using the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA/Vorinostat) and the DNA methylation inhibitor Zebularine (Zeb), with significantly more pronounced cytotoxicity in cells whose molecular phenotypes were indicative of aggressive biological behavior. These results suggested that the combination of these chromatin-modifying drugs may be a useful adjuvant in the treatment of rapidly progressive OS. PMID:22957032

Molecular design of flotation collectors: A recent progress.

PubMed

Liu, Guangyi; Yang, Xianglin; Zhong, Hong

2017-08-01

The nature of froth flotation is to selectively hydrophobize valuable minerals by collector adsorption so that the hydrophobized mineral particles can attach air bubbles. In recent years, the increasing commercial production of refractory complex ores has been urgent to develop special collectors for enhancing flotation separation efficiency of valuable minerals from these ores. Molecular design methods offer an effective way for understanding the structure-property relationship of flotation collectors and developing new ones. The conditional stability constant (CSC), molecular mechanics (MM), quantitative structure-activity relationship (QSAR), and first-principle theory, especially density functional theory (DFT), have been adopted to build the criteria for designing flotation collectors. Azole-thiones, guanidines, acyl thioureas and thionocarbamates, amide-hydroxamates, and double minerophilic-group surfactants such as Gemini, dithiourea and dithionocarbamate molecules have been recently developed as high-performance collectors. To design hydrophobic groups, the hydrophilic-hydrophobic balance parameters have been extensively used as criteria. The replacement of aryl group with aliphatic group or CC single bond(s) with CC double bond(s), reduction of carbon numbers, introduction of oxygen atom(s) and addition of trisiloxane to the tail terminal have been proved to be useful approaches for adjusting the surface activity of collectors. The role of molecular design of collectors in practical flotation applications was also summarized. Based on the critical review, some comments and prospects for further research on molecular design of flotation collectors were also presented in the paper. Copyright © 2017 Elsevier B.V. All rights reserved.

Inhibitors of procollagen C-terminal proteinase block gastrulation and spicule elongation in the sea urchin embryo.

PubMed

Huggins, L G; Lennarz, W J

2001-08-01

In the sea urchin embryo, inhibition of collagen processing and deposition affects both gastrulation and embryonic skeleton (spicule) formation. It has been found that cell-free extracts of gastrula-stage embryos of Strongylocentrotus purpuratus contain a procollagen C-terminal proteinase (PCP) activity. A rationally designed non-peptidic organic hydroxamate, which is a potent and specific inhibitor of human recombinant PCP (FG-HL1), inhibited both the sea urchin PCP as well as purified chick embryo tendon PCP. In the sea urchin embryo, FG-HL1 inhibited gastrulation and blocked spicule elongation, but not spicule nucleation. A related compound with a terminal carboxylate rather than a hydroxamate (FG-HL2) did not inhibit either chick PCP or sea urchin PCP activity in a procollagen-cleavage assay. However, FG-HL2 did block spicule elongation without affecting spicule nucleation or gastrulation. Neither compound was toxic, because their effects were reversible on removal. It was shown that the inhibition of gastrulation and spicule elongation were independent of tissue specification events, because both the endoderm specific marker Endo1 and the primary mesenchyme cell specific marker SM50 were expressed in embryos treated with FG-HL1 and FG-HL2. These results suggest that disruption of the fibrillar collagen deposition in the blastocoele blocks the cell movements of gastrulation and may disrupt the positional information contained within the extracellular matrix, which is necessary for spicule formation.

HDAC inhibitors as cognitive enhancers in fear, anxiety and trauma therapy: where do we stand?

PubMed Central

Whittle, Nigel; Singewald, Nicolas

2014-01-01

A novel strategy to treat anxiety and fear-related disorders such as phobias, panic and PTSD (post-traumatic stress disorder) is combining CBT (cognitive behavioural therapy), including extinction-based exposure therapy, with cognitive enhancers. By targeting and boosting mechanisms underlying learning, drug development in this field aims at designing CBT-augmenting compounds that help to overcome extinction learning deficits, promote long-term fear inhibition and thus support relapse prevention. Progress in revealing the role of epigenetic regulation of specific genes associated with extinction memory generation has opened new avenues in this direction. The present review examines recent evidence from pre-clinical studies showing that increasing histone acetylation, either via genetic or pharmacological inhibition of HDACs (histone deacetylases) by e.g. vorinostat/SAHA (suberoylanilide hydroxamic acid), entinostat/MS-275, sodium butyrate, TSA (trichostatin A) or VPA (valproic acid), or by targeting HATs (histone acetyltransferases), augments fear extinction and, importantly, generates a long-term extinction memory that can protect from return of fear phenomena. The molecular mechanisms and pathways involved including BDNF (brain-derived neurotrophic factor) and NMDA (N-methyl-D-aspartate) receptor signalling are just beginning to be revealed. First studies in healthy humans are in support of extinction-facilitating effects of HDAC inhibitors. Very recent evidence that HDAC inhibitors can rescue deficits in extinction-memory-impaired rodents indicates a potential clinical utility of this approach also for exposure therapy-resistant patients. Important future work includes investigation of the long-term safety aspects of HDAC inhibitor treatment, as well as design of isotype(s)-specific inhibitors. Taken together, HDAC inhibitors display promising potential as pharmacological adjuncts to augment the efficacy of exposure-based approaches in anxiety and trauma therapy. PMID:24646280

Class I Histone Deacetylase Inhibition by Tianeptinaline Modulates Neuroplasticity and Enhances Memory.

PubMed

Zhao, Wen-Ning; Ghosh, Balaram; Tyler, Marshall; Lalonde, Jasmin; Joseph, Nadine F; Kosaric, Nina; Fass, Daniel M; Tsai, Li-Huei; Mazitschek, Ralph; Haggarty, Stephen J

2018-06-22

Through epigenetic and other regulatory functions, the histone deacetylase (HDAC) family of enzymes has emerged as a promising therapeutic target for central nervous system and other disorders. Here we report on the synthesis and functional characterization of new HDAC inhibitors based structurally on tianeptine, a drug used primarily to treat major depressive disorder (MDD) that has a poorly understood mechanism of action. Since the chemical structure of tianeptine resembles certain HDAC inhibitors, we profiled the in vitro HDAC inhibitory activity of tianeptine and demonstrated its ability to inhibit the lysine deacetylase activity of a subset of class I HDACs. Consistent with a model of active site Zn 2+ chelation by the carboxylic acid present in tianeptine, newly synthesized analogues containing either a hydroxamic acid or ortho-aminoanilide exhibited increased potency and selectivity among the HDAC family. This in vitro potency translated to improved efficacy in a panel of high-content imaging assays designed to assess HDAC target engagement and functional effects on critical pathways involved in neuroplasticity in both primary mouse neurons and, for the first time, human neurons differentiated from pluripotent stem cells. Most notably, tianeptinaline, a class I HDAC-selective analogue of tianeptine, but not tianeptine itself, increased histone acetylation, and enhanced CREB-mediated transcription and the expression of Arc (activity-regulated cytoskeleton-associated protein). Systemic in vivo administration of tianeptinaline to mice confirmed its brain penetration and was found to enhance contextual fear conditioning, a behavioral test of hippocampal-dependent memory. Tianeptinaline and its derivatives provide new pharmacological tools to dissect chromatin-mediated neuroplasticity underlying memory and other epigenetically related processes implicated in health and disease.

Targeting Histone Deacetylases in Malignant Melanoma: A Future Therapeutic Agent or Just Great Expectations?

PubMed

Garmpis, Nikolaos; Damaskos, Christos; Garmpi, Anna; Dimitroulis, Dimitrios; Spartalis, Eleftherios; Margonis, Georgios-Antonios; Schizas, Dimitrios; Deskou, Irini; Doula, Chrysoula; Magkouti, Eleni; Andreatos, Nikolaos; Antoniou, Efstathios A; Nonni, Afroditi; Kontzoglou, Konstantinos; Mantas, Dimitrios

2017-10-01

Malignant melanoma is the most aggressive type of skin cancer, with increasing frequency and mortality. Melanoma is characterized by rapid proliferation and metastases. Malignant transformation of normal melanocytes is associated with imbalance between oncogenes' action and tumor suppressor genes. Mutations or inactivation of these genes plays an important role in the pathogenesis of malignant melanoma. Many target-specific agents improved progression-free survival but unfortunately metastatic melanoma remains incurable, so new therapeutic strategies are needed. The balance of histones' acetylation affects cell cycle progression, differentiation and apoptosis. Histone deacetylases (HDAC) are associated with different types of cancer. Histone deacetylase inhibitors (HDACI) are enzymes that inhibit the action of HDAC, resulting in block of tumor cell proliferation. A small number of these enzymes has been studied regarding their anticancer effects in melanoma. The purpose of this article was to review the therapeutic effect of HDACI against malignant melanoma, enlightening the molecular mechanisms of their action. The MEDLINE database was used. The keywords/ phrases were; HDACI, melanoma, targeted therapies for melanoma. Our final conclusions were based on studies that didn't refer solely to melanoma due to their wider experimental data. Thirty-two articles were selected from the total number of the search's results. Only English articles published until March 2017 were used. Molecules, such as valproid acid (VPA), LBH589, LAQ824 (dacinostat), vorinostat, tubacin, sirtinol and tx-527, suberoyl bis-hydroxamic acid (SBHA), depsipeptide and Trichostatin A (TSA) have shown promising antineoplastic effects against melanoma. HDACI represent a promising agent for targeted therapy. More trials are required. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Histone Deacetylase Inhibitors Stimulate Dedifferentiation of Human Breast Cancer Cells through WNT/β-catenin Signaling

PubMed Central

Debeb, Bisrat G; Lacerda, Lara; Xu, Wei; Larson, Richard; Solley, Travis; Atkinson, Rachel; Sulman, Erik P.; Ueno, Naoto T; Krishnamurthy, Savitri; Reuben, James M; Buchholz, Thomas A; Woodward, Wendy A

2015-01-01

Recent studies have shown that differentiated cancer cells can de-differentiate into cancer stem cells (CSCs) although to date no studies have reported whether this transition is influenced by systemic anti-cancer agents. Valproic acid (VA) is a histone deacetylase (HDAC) inhibitor that promotes self renewal and expansion of hematopietic stem cells and facilitates the generation of induced pluripotent stem cells from somatic cells and is currently being investigated in breast cancer clinical trials. We hypothesized that HDAC inhibitors reprogram differentiated cancer cells towards the more resistant stem cell-like state. Two highly aggressive breast cancer cell lines, SUM159 and MDA-231, were FACS-sorted based on ALDH activity and subsequently ALDH-negative and ALDH-positive cells were treated with one of two known HDAC inhibitors, VA or SAHA (suberoylanilide hydroxamic acid). In addition, primary tumor cells from patients with metastatic breast cancer were evaluated for ALDH activity following treatment with HDAC inhibitors. We demonstrate that single cell sorted ALDH- negative cells spontaneously generated ALDH-positive cells in vitro. Treatment of ALDH-negative cells with HDAC inhibitors promoted the expansion of ALDH-positive cells and increased mammosphere forming efficiency. Most importantly, it significantly increased the tumor-initiating capacity of ALDH- negative cells in limiting dilution outgrowth assays. Moreover, while HDAC inhibitors upregulated β-catenin expression and significantly increased WNT reporter activity, a TCF4 dominant negative construct abolished HDAC-inhibitor induced expansion of CSCs. These results demonstrate that HDAC inhibitors promote the expansion of breast CSCs through dedifferentiation and have important clinical implications for the use of HDAC inhibitors in the treatment of cancer. PMID:22961641

A metabolic screening study of trichostatin A (TSA) and TSA-like histone deacetylase inhibitors in rat and human primary hepatocyte cultures.

PubMed

Elaut, G; Laus, G; Alexandre, E; Richert, L; Bachellier, P; Tourwé, D; Rogiers, V; Vanhaecke, T

2007-04-01

Hydroxamic acid (HA)-based histone deacetylase (HDAC) inhibitors, with trichostatin A (TSA) as the reference compound, are potential antitumoral drugs and show promise in the creation of long-term primary cell cultures. However, their metabolic properties have barely been investigated. TSA is rapidly inactivated in rodents both in vitro and in vivo. We previously found that 5-(4-dimethylaminobenzoyl)aminovaleric acid hydroxyamide or 4-Me2N-BAVAH (compound 1) is metabolically more stable upon incubation with rat hepatocyte suspensions. In this study, we show that human hepatocytes also metabolize TSA more rapidly than compound 1 and that similar pathways are involved. Furthermore, structural analogs of compound 1 (compounds 2-9) are reported to have the same favorable metabolic properties. Removal of the dimethylamino substituent of compound 1 creates a very stable but 50% less potent inhibitor. Chain lengthening (4 to 5 carbon spacer) slightly improves both potency and metabolic stability, favoring HA reduction to hydrolysis. On the other hand, Calpha-unsaturation and spacer methylation not only reduce HDAC inhibition but also increase the rate of metabolic inactivation approximately 2-fold, mainly through HA reduction. However, in rat hepatocyte monolayer cultures, compound 1 is shown to be extensively metabolized by phase II conjugation. In conclusion, this study suggests that simple structural modifications of amide-linked TSA analogs can improve their phase I metabolic stability in both rat and human hepatocyte suspensions. Phase II glucuronidation, however, can compensate for their lower phase I metabolism in rat hepatocyte monolayers and could play a yet unidentified role in the determination of their in vivo clearance.

Participation of fad and mbt Genes in Synthesis of Mycobactin in Mycobacterium smegmatis

PubMed Central

LaMarca, B. Babbette D.; Zhu, Wenming; Arceneaux, Jean E. L.; Rowe Byers, B.; Lundrigan, Michael D.

2004-01-01

Colonies of Mycobacterium smegmatis LR222 on iron-limiting (0.1 μM Fe) minimal medium agar fluoresce under UV light due to the accumulation in the cells of the deferri form of the siderophore mycobactin. Two mutants with little or no fluorescence, designated LUN8 and LUN9, were isolated by screening colonies of transposon (Tn611)-mutagenized M. smegmatis. Ferrimycobactin prepared from iron-restricted cells of the wild type had an Rf of 0.62 on high-performance thin-layer chromatography (HPTLC) and a characteristic visible absorption spectrum with a peak near 450 nm. Similar extracts from LUN8 cells contained a small amount of ferrimycobactin with an Rf of 0.58 on HPTLC and an absorption spectrum with the peak shifted to a wavelength lower than that of the wild-type ferrimycobactin. Nuclear magnetic resonance spectroscopy studies suggested that the LUN8 mycobactin may have an altered fatty acid side chain. Mutant strain LUN9 produced no detectable mycobactin. Neither mutant strain produced measurable amounts of excreted mycobactin, although both excreted exochelin (the mycobacterial peptido-hydroxamate siderophore), and both mutants were more sensitive than the wild-type strain to growth inhibition by the iron chelator ethylenediamine-di(o-hydroxyphenylacetic acid). The transposon insertion sites were identified, and sequence analyses of the cloned flanking chromosome regions showed that the mutated gene in LUN9 was an orthologue of the Mycobacterium tuberculosis mycobactin biosynthetic gene mbtE. The mutated gene in LUN8 had homology with M. tuberculosis fadD33 (Rv1345), a gene that may encode an acyl-coenzyme A synthase and which previously was not known to participate in synthesis of mycobactin. PMID:14702306

Global gene expression during stringent response in Corynebacterium glutamicum in presence and absence of the rel gene encoding (p)ppGpp synthase

PubMed Central

Brockmann-Gretza, Olaf; Kalinowski, Jörn

2006-01-01

Background The stringent response is the initial reaction of microorganisms to nutritional stress. During stringent response the small nucleotides (p)ppGpp act as global regulators and reprogram bacterial transcription. In this work, the genetic network controlled by the stringent response was characterized in the amino acid-producing Corynebacterium glutamicum. Results The transcriptome of a C. glutamicum rel gene deletion mutant, unable to synthesize (p)ppGpp and to induce the stringent response, was compared with that of its rel-proficient parent strain by microarray analysis. A total of 357 genes were found to be transcribed differentially in the rel-deficient mutant strain. In a second experiment, the stringent response was induced by addition of DL-serine hydroxamate (SHX) in early exponential growth phase. The time point of the maximal effect on transcription was determined by real-time RT-PCR using the histidine and serine biosynthetic genes. Transcription of all of these genes reached a maximum at 10 minutes after SHX addition. Microarray experiments were performed comparing the transcriptomes of SHX-induced cultures of the rel-proficient strain and the rel mutant. The differentially expressed genes were grouped into three classes. Class A comprises genes which are differentially regulated only in the presence of an intact rel gene. This class includes the non-essential sigma factor gene sigB which was upregulated and a large number of genes involved in nitrogen metabolism which were downregulated. Class B comprises genes which were differentially regulated in response to SHX in both strains, independent of the rel gene. A large number of genes encoding ribosomal proteins fall into this class, all being downregulated. Class C comprises genes which were differentially regulated in response to SHX only in the rel mutant. This class includes genes encoding putative stress proteins and global transcriptional regulators that might be responsible for the complex transcriptional patterns detected in the rel mutant when compared directly with its rel-proficient parent strain. Conclusion In C. glutamicum the stringent response enfolds a fast answer to an induced amino acid starvation on the transcriptome level. It also showed some significant differences to the transcriptional reactions occuring in Escherichia coli and Bacillus subtilis. Notable are the rel-dependent regulation of the nitrogen metabolism genes and the rel-independent regulation of the genes encoding ribosomal proteins. PMID:16961923

3D-quantitative structure-activity relationship studies on benzothiadiazepine hydroxamates as inhibitors of tumor necrosis factor-alpha converting enzyme.

PubMed

Murumkar, Prashant R; Giridhar, Rajani; Yadav, Mange Ram

2008-04-01

A set of 29 benzothiadiazepine hydroxamates having selective tumor necrosis factor-alpha converting enzyme inhibitory activity were used to compare the quality and predictive power of 3D-quantitative structure-activity relationship, comparative molecular field analysis, and comparative molecular similarity indices models for the atom-based, centroid/atom-based, data-based, and docked conformer-based alignment. Removal of two outliers from the initial training set of molecules improved the predictivity of models. Among the 3D-quantitative structure-activity relationship models developed using the above four alignments, the database alignment provided the optimal predictive comparative molecular field analysis model for the training set with cross-validated r(2) (q(2)) = 0.510, non-cross-validated r(2) = 0.972, standard error of estimates (s) = 0.098, and F = 215.44 and the optimal comparative molecular similarity indices model with cross-validated r(2) (q(2)) = 0.556, non-cross-validated r(2) = 0.946, standard error of estimates (s) = 0.163, and F = 99.785. These models also showed the best test set prediction for six compounds with predictive r(2) values of 0.460 and 0.535, respectively. The contour maps obtained from 3D-quantitative structure-activity relationship studies were appraised for activity trends for the molecules analyzed. The comparative molecular similarity indices models exhibited good external predictivity as compared with that of comparative molecular field analysis models. The data generated from the present study helped us to further design and report some novel and potent tumor necrosis factor-alpha converting enzyme inhibitors.

Rational Design, Development, and Stability Assessment of a Macrocyclic Four-Hydroxamate-Bearing Bifunctional Chelating Agent for 89 Zr.

PubMed

Seibold, Uwe; Wängler, Björn; Wängler, Carmen

2017-09-21

Zirconium-89 is a positron-emitting radionuclide of high interest for medical imaging applications with positron emission tomography (PET). For the introduction of this radiometal into biologically active targeting vectors, the chelating agent desferrioxamine B (DFO) is commonly applied. However, DFO is known to form 89 Zr complexes of limited in vivo stability. Herein we describe the rational design and chemical development of a new macrocyclic four-hydroxamate-bearing chelating agent-1,10,19,28-tetrahydroxy-1,5,10,14,19,23,28,32-octaazacyclohexatriacontan-2,6,11,15,20,24,29,33-octaone (CTH36)-for the stable complexation of Zr 4+ . For this purpose, we first performed computational studies to determine the optimal chelator geometry before we developed different synthesis pathways toward the target structures. The best results were obtained using an efficient solution-phase-based synthesis strategy toward the target chelating agent. To enable efficient and chemoselective conjugation to biomolecules, a tetrazine-modified variant of CTH36 was also developed. The excellent conjugation characteristics of the so-functionalized chelator were demonstrated on the example of the model peptide TCO-c(RGDfK). We determined the optimal 89 Zr radiolabeling parameters for CTH36 as well as its bioconjugate, and found that 89 Zr radiolabeling proceeds efficiently under very mild reaction conditions. Finally, we performed comparative complex stability tests for 89 Zr-CHT36-c(RGDfK) and 89 Zr-DFO-c(RGDfK), showing improved complex stability for the newly developed chelator CTH36. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Subchronic Toxicities of HZ1006, a Hydroxamate-Based Histone Deacetylase Inhibitor, in Beagle Dogs and Sprague-Dawley Rats.

PubMed

Zhang, Xiaofang; Zhang, Xiaodong; Yuan, Bojun; Ren, Lijun; Zhang, Tianbao; Lu, Guocai

2016-11-30

Histone deacetylase inhibitors (HDACIs), such as vorinostat and panobinostat, have been shown to have active effects on many hematologic malignancies, including multiple myeloma and cutaneous T-cell lymphoma. Hydroxamate-based (Hb) HDACIs have very good toxicity profiles and are currently being tested in phases I and II clinical trials with promising results in selected neoplasms, such as bladder carcinoma. One of the Hb-HDACIs, HZ1006, has been demonstrated to be a promising drug for clinical use. The aim of our study was to determine the possible target of toxicity and to identify a non-toxic dose of HZ1006 for clinical use. In our studies, the repeated dosage toxicity of HZ1006 in Beagle dogs and Sprague Dawley (SD) rats was identified. Dogs and rats received HZ1006 orally (0-80 and 0-120 mg/kg/day, respectively) on a continuous daily dosing agenda for 28 days following a 14-day dosage-free period. HZ1006's NOAEL (No Observed Adverse Effect Level) by daily oral administration for dogs and rats was 5 mg/kg and 60 mg/kg, respectively, and the minimum toxic dose was 20 and 120 mg/kg, respectively. All the side effects indicated that the digestive tract, the male reproductive tract, the respiratory tract and the hematological systems might be HZ1006 toxic targets in humans. HZ1006 could be a good candidate or a safe succedaneum to other existing HDACIs for the treatment of some solid tumor and hematologic malignancies.

Adsorption of Pb(ll) and Eu(III) by oxide minerals in the presence of natural and synthetic hydroxamate siderophores.

PubMed

Kraemer, Stephan M; Xu, Jide; Raymond, Kenneth N; Sposito, Garrison

2002-03-15

Trihydroxamate siderophores have been proposed for use as mediators of actinide and heavy metal mobility in contaminated subsurface zones. These microbially produced ligands, common in terrestrial and marine environments, recently have been derivatized synthetically to enhance their affinity for transuranic metal cations. However, the interactions between these synthetic derivative and adsorbed trace metals have not been characterized. In this paper we compare a natural siderophore, desferrioxamine-B (DFO-B), with its actinide-specific catecholate derivative, N-(2,3-dihydroxy-4-(methylamido)benzoyl)desferrioxamine-B (DFOMTA), as to their effect on the adsorption of Pb(II) and Eu(III) by goethite and boehmite. In the presence of 240 microM DFO-B, a strongly depleting effect on Eu(III) adsorption by goethite and boehmite occurred above pH 6. By contrast, almost total removal of Eu(III) from solution in the neutral to slightly acidic pH range was observed in the presence of either 10 or 100 microM DFOMTA, due primarilyto the formation of metal-DFOMTA precipitates. Addition of DFOMTA caused an increase in Pb(II) adsorption by goethite below pH 5, but a decrease above pH 5, such that the Pb(II) adsorption edge in the presence of DFOMTA strongly resembled the DFOMTA adsorption envelope, which showed a maximum near pH 5 and decreasing adsorption toward lower and higher pH.

The Histoplasma capsulatum Vacuolar ATPase is Required for Iron Homeostasis, Intracellular Replication in Macrophages, and Virulence in a Murine Model of Histoplasmosis

PubMed Central

Hilty, Jeremy; Smulian, A. George; Newman, Simon L.

2008-01-01

Summary Histoplasma capsulatum is a dimorphic fungal pathogen that survives and replicates within macrophages (Mϕ). To identify specific genes required for intracellular survival, we utilized Agrobacterium tumefaciens-mediated mutagenesis, and screened for H. capsulatum insertional mutants that were unable to survive in human Mϕ. One colony was identified that had an insertion within VMA1, the catalytic subunit A of the vacuolar ATPase (V-ATPase). The vma1 mutant (vma1::HPH) grew normally on iron replete medium, but not on iron deficient media. On iron deficient medium, the growth of the vma1 mutant was restored in the presence of wild type (WT) H. capsulatum yeasts, or the hydroxamate siderophore, rhodotorulic acid. However, the inability to replicate within Mϕ was only partially restored by the addition of exogenous iron. The vma1::HPH mutant also did not grow as a mold at 28°C. Complementation of the mutant (vma/VMA1) restored its ability to replicate in Mϕ, grow on iron poor medium, and grow as a mold at 28°C. The vma1::HPH mutant was avirulent in a mouse model of histoplasmosis, whereas the vma1/VMA1 strain was as pathogenic as WT yeasts. These studies demonstrate the importance of V-ATPase function in the pathogenicity of H. capsulatum, in iron homeostasis, and in fungal dimorphism. PMID:18699866

Enhancement of Radiation Response in Osteosarcoma and Rhabomyosarcoma Cell Lines by Histone Deacetylase Inhibition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blattmann, Claudia, E-mail: claudia.blattmann@med.uni-heidelberg.d; Oertel, Susanne; Ehemann, Volker

2010-09-01

Purpose: Histone deacetylase inhibitors (HDACIs) can enhance the sensitivity of cells to photon radiation treatment (XRT) by altering numerous molecular pathways. We investigated the effect of pan-HDACIs such as suberoylanilide hydroxamic acid (SAHA) on radiation response in two osteosarcoma (OS) and two rhabdomyosarcoma (RMS) cell lines. Methods and Materials: Clonogenic survival, cell cycle analysis, and apoptosis were examined in OS (KHOS-24OS, SAOS2) and RMS (A-204, RD) cell lines treated with HDACI and HDACI plus XRT, respectively. Protein expression was investigated via immunoblot analysis, and cell cycle analysis and measurement of apoptosis were performed using flow cytometry. Results: SAHA induced anmore » inhibition of cell proliferation and clonogenic survival in OS and RMS cell lines and led to a significant radiosensitization of all tumor cell lines. Other HDACI such as M344 and valproate showed similar effects as investigated in one OS cell line. Furthermore, SAHA significantly increased radiation-induced apoptosis in the OS cell lines, whereas in the RMS cell lines radiation-induced apoptosis was insignificant with and without SAHA. In all investigated sarcoma cell lines, SAHA attenuated radiation-induced DNA repair protein expression (Rad51, Ku80). Conclusion: Our results show that HDACIs enhance radiation action in OS and RMS cell lines. Inhibition of DNA repair, as well as increased apoptosis induction after exposure to HDACIs, can be mechanisms of radiosensitization by HDACIs.« less

Kinome expression profiling of human neuroblastoma tumors identifies potential drug targets for ultra high-risk patients.

PubMed

Russo, Roberta; Cimmino, Flora; Pezone, Lucia; Manna, Francesco; Avitabile, Marianna; Langella, Concetta; Koster, Jan; Casale, Fiorina; Raia, Maddalena; Viola, Giampietro; Fischer, Matthias; Iolascon, Achille; Capasso, Mario

2017-10-01

Neuroblastoma (NBL) accounts for >7% of malignancies in patients younger than 15 years. Low- and intermediate-risk patients exhibit excellent or good prognosis after treatment, whereas for high-risk (HR) patients, the estimated 5-year survival rates is still <40%. The ability to stratify HR patients that will not respond to standard treatment strategies is critical for informed treatment decisions. In this study, we have generated a specific kinome gene signature, named Kinome-27, which is able to identify a subset of HR-NBL tumors, named ultra-HR NBL, with highly aggressive clinical behavior that not adequately respond to standard treatments. We have demonstrated that NBL cell lines expressing the same kinome signature of ultra-HR tumors (ultra-HR-like cell lines) may be selectively targeted by the use of two drugs [suberoylanilide hydroxamic acid (SAHA) and Radicicol], and that the synergic combination of these drugs is able to block the ultra-HR-like cells in G2/M phase of cell cycle. The use of our signature in clinical practice will allow identifying patients with negative outcome, which would benefit from new and more personalized treatments. Preclinical in vivo studies are needed to consolidate the SAHA and Radicicol treatment in ultra-HR NBL patients. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Histone deacetylase inhibition modulates indoleamine 2,3-dioxygenase–dependent DC functions and regulates experimental graft-versus-host disease in mice

PubMed Central

Reddy, Pavan; Sun, Yaping; Toubai, Tomomi; Duran-Struuck, Raimon; Clouthier, Shawn G.; Weisiger, Elizabeth; Maeda, Yoshinobu; Tawara, Isao; Krijanovski, Oleg; Gatza, Erin; Liu, Chen; Malter, Chelsea; Mascagni, Paolo; Dinarello, Charles A.; Ferrara, James L.M.

2008-01-01

Histone deacetylase (HDAC) inhibitors are antitumor agents that also have antiinflammatory properties. However, the mechanisms of their immunomodulatory functions are not known. We investigated the mechanisms of action of 2 HDAC inhibitors, suberoylanilide hydroxamic acid (SAHA) and ITF 2357, on mouse DC responses. Pretreatment of DCs with HDAC inhibitors significantly reduced TLR-induced secretion of proinflammatory cytokines, suppressed the expression of CD40 and CD80, and reduced the in vitro and in vivo allostimulatory responses induced by the DCs. In addition, injection of DCs treated ex vivo with HDAC inhibitors reduced experimental graft-versus-host disease (GVHD) in a murine allogeneic BM transplantation model. Exposure of DCs to HDAC inhibitors increased expression of indoleamine 2,3-dioxygenase (IDO), a suppressor of DC function. Blockade of IDO in WT DCs with siRNA and with DCs from IDO-deficient animals caused substantial reversal of HDAC inhibition–induced in vitro suppression of DC-stimulated responses. Direct injection of HDAC inhibitors early after allogeneic BM transplantation to chimeric animals whose BM-derived cells lacked IDO failed to protect from GVHD, demonstrating an in vivo functional role for IDO. Together, these data show that HDAC inhibitors regulate multiple DC functions through the induction of IDO and suggest that they may represent a novel class of agents to treat immune-mediated diseases. PMID:18568076

Potentiation of apoptosis by histone deacetylase inhibitors and doxorubicin combination: cytoplasmic cathepsin B as a mediator of apoptosis in multiple myeloma.

PubMed

Cheriyath, V; Kuhns, M A; Kalaycio, M E; Borden, E C

2011-03-15

Although inhibitors of histone deacetylase inhibitors (HDACis) in combination with genotoxins potentiate apoptosis, the role of proteases other than caspases in this process remained elusive. Therefore, we examined the potentiation of apoptosis and related mechanisms of HDACis and doxorubicin combination in a panel of myeloma cell lines and in 25 primary myelomas. At IC(50) concentrations, sodium butyrate (an HDACi) or doxorubicin alone caused little apoptosis. However, their combination potentiated apoptosis and synergistically reduced the viability of myeloma cells independent of p53 and caspase 3-7 activation. Potentiated apoptosis correlated with nuclear translocation of apoptosis-inducing factor, suggesting the induction of caspase 3- and 7-independent pathways. Consistent with this, butyrate and doxorubicin combination significantly increased the activity of cytoplasmic cathepsin B. Inhibition of cathepsin B either with a small-molecule inhibitor or downregulation with a siRNA reversed butyrate- and doxorubicin-potentiated apoptosis. Finally, ex vivo, clinically relevant concentrations of butyrate or SAHA (suberoylanilide hydroxamic acid, vorinostat, an HDACi in clinical testing) in combination with doxorubicin significantly (P<0.0001) reduced the survival of primary myeloma cells. Cathepsin B has a prominent function in mediating apoptosis potentiated by HDACi and doxorubicin combinations in myeloma. Our results support a molecular model of lysosomal-mitochondrial crosstalk in HDACi- and doxorubicin-potentiated apoptosis through the activation of cathepsin B.

Mechanical stretch induces MMP-2 release and activation in lung endothelium: role of EMMPRIN.

PubMed

Haseneen, Nadia A; Vaday, Gayle G; Zucker, Stanley; Foda, Hussein D

2003-03-01

High-volume mechanical ventilation leads to ventilator-induced lung injury. This type of lung injury is accompanied by an increased release and activation of matrix metalloproteinases (MMPs). To investigate the mechanism leading to the increased MMP release, we systematically studied the effect of mechanical stretch on human microvascular endothelial cells isolated from the lung. We exposed cells grown on collagen 1 BioFlex plates to sinusoidal cyclic stretch at 0.5 Hz using the Flexercell system with 17-18% elongation of cells. After 4 days of cell stretching, conditioned media and cell lysate were collected and analyzed by gelatin, casein, and reverse zymograms as well as Western blotting. RT-PCR of mRNA extracted from stretched cells was performed. Our results show that 1) cyclic stretch led to increased release and activation of MMP-2 and MMP-1; 2) the activation of MMP-2 was accompanied by an increase in membrane type-1 MMP (MT1-MMP) and inhibited by a hydroxamic acid-derived inhibitor of MMPs (Prinomastat, AG3340); and 3) the MMP-2 release and activation were preceded by an increase in production of extracellular MMP inducer (EMMPRIN). These results suggest that cyclic mechanical stretch leads to MMP-2 activation through an MT1-MMP mechanism. EMMPRIN may play an important role in the release and activation of MMPs during lung injury.

Effect of a Histone Deacetylases Inhibitor of IL-18 and TNF-Alpha Secretion in Vitro.

PubMed

Dobreva, Zlatka Georgieva; Grigorov, Boncho Grigorov; Stanilova, Spaska Angelova

2018-02-15

Interleukin-18 (IL-18) and Tumor Necrosis Factor-alpha (TNF-α) are proinflammatory cytokines that increased the development of Th1 immune response, but have a different type of regulation of the gene expression. Whereas TNF-α has an inducible expression, IL-18 is translated as an inactive protein and required proteolytic cleavage by Casp-1 in inflammasome complexes. To investigate the effect of the histone deacetylases inhibitor Suberoylanilide Hydroxamic Acid (SAHA) on the gene expression and secretion of both cytokines, IL-18 and TNF-α, according to their contribution to the cancer development and anticancer immunity. Isolated peripheral blood mononuclear cells (PBMC) were stimulated with LPS and C3bgp with or without SAHA. Cytokine production was assessed by ELISA at 6 and 24h. IL-18 and TNF-α secretion was significantly increased at 6h and 24h in response to stimulation. TNF-α production from stimulated PBMC was downregulated by SAHA at 6 and 24h. Treatment with SAHA does not inhibit the secretion of IL-18 significantly either at 6 or 24h of stimulation. The inhibition of histone deacetylases by SAHA does not influence the inflammasome-dependent production of immunologically active IL-18. In contrast, the production of proinflammatory TNF-α in cultures was mediated by the activity of HDAC class I and class II enzymes.

Targeting histone deacetylase inhibitors for anti-malarial therapy.

PubMed

Andrews, Katherine T; Tran, Thanh N; Wheatley, Nicole C; Fairlie, David P

2009-01-01

It is now clear that histone acetylation plays key roles in regulating gene transcription in both eukaryotes and prokaryotes, the acetylated form inducing gene expression while deacetylation silences genes. Recent studies have identified roles for histone acetyltransferases (HATs) and/or histone deacetylases (HDACs) in a number of parasites including Entamoeba histolytica, Toxoplasma gondii, Schistosoma mansoni, Cryptosporidium sp., Leishmania donovani, Neospora caninum, and Plasmodium falciparum. Here we survey fairly limited efforts to date in profiling antimalarial activities of HDAC inhibitors, showing that such compounds are potent inhibitors of the growth of P. falciparum in vitro and in vivo. Most of the compounds evaluated so far have borne a zinc-binding hydroxamate group that tends to be metabolized in vivo, and thus new zinc-binding groups need to be incorporated into second generation inhibitors in order to mask the catalytic zinc in the active site of HDACs. Also the development of compounds that are selective for parasitic HDACs over mammalian HDACs is still in relative infancy and it will take some time to derive antiparasitic HDAC inhibitor compounds with minimal toxicity for the host and acceptable pharmacokinetic and pharmacodynamic profiles for human treatment. Nevertheless, results to date suggest that HDAC inhibitor development represents a promising new approach to the potential treatment of parasitic infections, including those induced by malaria protozoa, and may offer new therapeutic targets within increasingly drug-resistant malarial parasites.

Siderophores mediate reduced and increased uptake of cadmium by Streptomyces tendae F4 and sunflower (Helianthus annuus), respectively.

PubMed

Dimkpa, C O; Merten, D; Svatos, A; Büchel, G; Kothe, E

2009-11-01

As a toxic metal, cadmium (Cd) affects microbial and plant metabolic processes, thereby potentially reducing the efficiency of microbe or plant-mediated remediation of Cd-polluted soil. The role of siderophores produced by Streptomyces tendae F4 in the uptake of Cd by bacteria and plant was investigated to gain insight into the influence of siderophores on Cd availability to micro-organisms and plants. The bacterium was cultured under siderophore-inducing conditions in the presence of Cd. The kinetics of siderophore production and identification of the siderophores and their metal-bound forms were performed using electrospray ionization mass spectrometry. Inductively coupled plasma spectroscopy was used to measure iron (Fe) and Cd contents in the bacterium and in sunflower plant grown in Cd-amended soil. Siderophores significantly reduced the Cd uptake by the bacterium, while supplying it with iron. Bacterial culture filtrates containing three hydroxamate siderophores secreted by S. tendae F4 significantly promoted plant growth and enhanced uptake of Cd and Fe by the plant, relative to the control. Furthermore, application of siderophores caused slightly more Cd, but similar Fe uptake, compared with EDTA. Bioinoculation with Streptomyces caused a dramatic increase in plant Fe content, but resulted only in slight increase in plant Cd content. It is concluded that siderophores can help reduce toxic metal uptake in bacteria, while simultaneously facilitating the uptake of such metals by plants. Also, EDTA is not superior to hydroxamate siderophores in terms of metal solubilization for plant uptake. The study showed that microbial processes could indirectly influence the availability and amount of toxic metals taken up from the rhizosphere of plants. Furthermore, although EDTA is used for chelator-enhanced phytoremediation, microbial siderophores would be ideal for this purpose.

Constructing and Validating 3D-pharmacophore Models to a Set of MMP-9 Inhibitors for Designing Novel Anti-melanoma Agents.

PubMed

Medeiros Turra, Kely; Pineda Rivelli, Diogo; Berlanga de Moraes Barros, Silvia; Mesquita Pasqualoto, Kerly Fernanda

2016-07-01

A receptor-independent (RI) four-dimensional structure-activity relationship (4D-QSAR) formalism was applied to a set of sixty-four β-N-biaryl ether sulfonamide hydroxamate derivatives, previously reported as potent inhibitors against matrix metalloproteinase subtype 9 (MMP-9). MMP-9 belongs to a group of enzymes related to the cleavage of several extracellular matrix components and has been associated to cancer invasiveness/metastasis. The best RI 4D-QSAR model was statistically significant (N=47; r(2) =0.91; q(2) =0.83; LSE=0.09; LOF=0.35; outliers=0). Leave-N-out (LNO) and y-randomization approaches indicated the QSAR model was robust and presented no chance correlation, respectively. Furthermore, it also had good external predictability (82 %) regarding the test set (N=17). In addition, the grid cell occupancy descriptors (GCOD) of the predicted bioactive conformation for the most potent inhibitor were successfully interpreted when docked into the MMP-9 active site. The 3D-pharmacophore findings were used to predict novel ligands and exploit the MMP-9 calculated binding affinity through molecular docking procedure. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In Vitro and In Vivo Plant Growth Promoting Activities and DNA Fingerprinting of Antagonistic Endophytic Actinomycetes Associates with Medicinal Plants.

PubMed

Passari, Ajit Kumar; Mishra, Vineet Kumar; Gupta, Vijai Kumar; Yadav, Mukesh Kumar; Saikia, Ratul; Singh, Bhim Pratap

2015-01-01

Endophytic actinomycetes have shown unique plant growth promoting as well as antagonistic activity against fungal phytopathogens. In the present study forty-two endophytic actinomycetes recovered from medicinal plants were evaluated for their antagonistic potential and plant growth-promoting abilities. Twenty-two isolates which showed the inhibitory activity against at least one pathogen were subsequently tested for their plant-growth promoting activities and were compared genotypically using DNA based fingerprinting, including enterobacterial repetitive intergenic consensus (ERIC) and BOX repetitive elements. Genetic relatedness based on both ERIC and BOX-PCR generates specific patterns corresponding to particular genotypes. Exponentially grown antagonistic isolates were used to evaluate phosphate solubilization, siderophores, HCN, ammonia, chitinase, indole-3-acetic acid production, as well as antifungal activities. Out of 22 isolates, the amount of indole-3-acetic acid (IAA) ranging between 10-32 μg/ml was produced by 20 isolates and all isolates were positive for ammonia production ranging between 5.2 to 54 mg/ml. Among 22 isolates tested, the amount of hydroxamate-type siderophores were produced by 16 isolates ranging between 5.2 to 36.4 μg/ml, while catechols-type siderophores produced by 5 isolates ranging from 3.2 to 5.4 μg/ml. Fourteen isolates showed the solubilisation of inorganic phosphorous ranging from 3.2 to 32.6 mg/100ml. Chitinase and HCN production was shown by 19 and 15 different isolates, respectively. In addition, genes of indole acetic acid (iaaM) and chitinase (chiC) were successively amplified from 20 and 19 isolates respectively. The two potential strains Streptomyces sp. (BPSAC34) and Leifsonia xyli (BPSAC24) were tested in vivo and improved a range of growth parameters in chilli (Capsicum annuum L.) under greenhouse conditions. This study is the first published report that actinomycetes can be isolated as endophytes from within these plants and were shown to have antagonistic and plant growth promoting abilities. These results clearly suggest the possibility of using endophytic actinomycetes as bioinoculant for plant growth promotion, nutrient mobilization or as biocontrol agent against fungal phytopathogens for sustainable agriculture.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hiser, C.; Herdies, L.; McIntosh, L.

Higher plant mitochondria posses a cyanide-resistant, hydroxamate-sensitive alternative pathway of electron transport that does not conserve energy. Aging of potato tuber slices for 24 hours leads to the development of an alternative pathway capacity. We have shown that a monoclonal antibody raised against the alternative pathway terminal oxidase of Sauromatum guttatum crossreacts with a protein of similar size in aged potato slice mitochondria. This protein was partially purified and characterized by two-dimensional gel electrophoresis, and its relative levels parallel the rise in cyanide-resistant respiration. We are using a putative clone of the S. guttatum alternative oxidase gene to isolate themore » equivalent gene from potato and to examine its expression.« less

Structural characteristics of ScBx genes controlling the biosynthesis of hydroxamic acids in rye (Secale cereale L.).

PubMed

Bakera, Beata; Makowska, Bogna; Groszyk, Jolanta; Niziołek, Michał; Orczyk, Wacław; Bolibok-Brągoszewska, Hanna; Hromada-Judycka, Aneta; Rakoczy-Trojanowska, Monika

2015-08-01

Benzoxazinoids (BX) are major secondary metabolites of gramineous plants that play an important role in disease resistance and allelopathy. They also have many other unique properties including anti-bacterial and anti-fungal activity, and the ability to reduce alfa-amylase activity. The biosynthesis and modification of BX are controlled by the genes Bx1 ÷ Bx10, GT and glu, and the majority of these Bx genes have been mapped in maize, wheat and rye. However, the genetic basis of BX biosynthesis remains largely uncharacterized apart from some data from maize and wheat. The aim of this study was to isolate, sequence and characterize five genes (ScBx1, ScBx2, ScBx3, ScBx4 and ScBx5) encoding enzymes involved in the synthesis of DIBOA, an important defense compound of rye. Using a modified 3D procedure of BAC library screening, seven BAC clones containing all of the ScBx genes were isolated and sequenced. Bioinformatic analyses of the resulting contigs were used to examine the structure and other features of these genes, including their promoters, introns and 3'UTRs. Comparative analysis showed that the ScBx genes are similar to those of other Poaceae species, especially to the TaBx genes. The polymorphisms present both in the coding sequences and non-coding regions of ScBx in relation to other Bx genes are predicted to have an impact on the expression, structure and properties of the encoded proteins.

The HDAC inhibitor SAHA does not rescue CFTR membrane expression in Cystic Fibrosis.

PubMed

Bergougnoux, Anne; Petit, Aurélie; Knabe, Lucie; Bribes, Estelle; Chiron, Raphaël; De Sario, Albertina; Claustres, Mireille; Molinari, Nicolas; Vachier, Isabelle; Taulan-Cadars, Magali; Bourdin, Arnaud

2017-07-01

The development of suitable Cystic Fibrosis (CF) models for preclinical bench tests of therapeutic candidates is challenging. Indeed, the validation of molecules to rescue the p.Phe508del-CFTR channel (encoded by the Cystic Fibrosis Transmembrane conductance Regulator gene carrying the p.Phe508del mutation) requires taking into account their overall effects on the epithelium. Suberoylanilide Hydroxamic Acid (SAHA), a histone deacetylase inhibitor (HDACi), was previously shown to be a CFTR corrector via proteostasis modulation in CFTR-deficient immortalized cells. Here, we tested SAHA effects on goblet cell metaplasia using an ex vivo model based on the air-liquid interface (ALI) culture of differentiated airway epithelial cells obtained by nasal scraping from CF patients and healthy controls. Ex vivo epithelium grew successfully in ALI cultures with significant rise in the expression of CFTR and of markers of airway epithelial differentiation compared to monolayer cell culture. SAHA decreased CFTR transcript and protein levels in CF and non-CF epithelia. Whereas SAHA induced lysine hyperacetylation, it did not change histone modifications at the CFTR promoter. SAHA reduced MUC5AC and MUC5B expression and inhibited goblet epithelial cell differentiation. Similar effects were obtained in CF and non-CF epithelia. All the effects were fully reversible within five days from SAHA withdrawal. We conclude that, ex vivo, SAHA modulate the structure of airway epithelia without specific effect on CFTR gene and protein suggesting that HDACi cannot be useful for CF treatment. Copyright © 2017. Published by Elsevier Ltd.

Soluble Axl Is Generated by ADAM10-Dependent Cleavage and Associates with Gas6 in Mouse Serum†

PubMed Central

Budagian, Vadim; Bulanova, Elena; Orinska, Zane; Duitman, Erwin; Brandt, Katja; Ludwig, Andreas; Hartmann, Dieter; Lemke, Greg; Saftig, Paul; Bulfone-Paus, Silvia

2005-01-01

Axl receptor tyrosine kinase exists as a transmembrane protein and as a soluble molecule. We show that constitutive and phorbol 12-myristate 13-acetate-induced generation of soluble Axl (sAxl) involves the activity of disintegrin-like metalloproteinase 10 (ADAM10). Spontaneous and inducible Axl cleavage was inhibited by the broad-spectrum metalloproteinase inhibitor GM6001 and by hydroxamate GW280264X, which is capable of blocking ADAM10 and ADAM17. Furthermore, murine fibroblasts deficient in ADAM10 expression exhibited a significant reduction in constitutive and inducible Axl shedding, whereas reconstitution of ADAM10 restored sAxl production, suggesting that ADAM10-mediated proteolysis constitutes a major mechanism for sAxl generation in mice. Partially overlapping 14-amino-acid stretch deletions in the membrane-proximal region of Axl dramatically affected sAxl generation, indicating that these regions are involved in regulating the access of the protease to the cleavage site. Importantly, relatively high circulating levels of sAxl are present in mouse sera in a heterocomplex with Axl ligand Gas6. Conversely, two other family members, Tyro3 and Mer, were not detected in mouse sera and conditioned medium. sAxl is constitutively released by murine primary cells such as dendritic and transformed cell lines. Upon immobilization, sAxl promoted cell migration and induced the phosphorylation of Axl and phosphatidylinositol 3-kinase. Thus, ADAM10-mediated generation of sAxl might play an important role in diverse biological processes. PMID:16227584

BCL11B-Mediated Epigenetic Repression Is a Crucial Target for Histone Deacetylase Inhibitors in Cutaneous T-Cell Lymphoma.

PubMed

Fu, Wenjing; Yi, Shengguo; Qiu, Lei; Sun, Jingru; Tu, Ping; Wang, Yang

2017-07-01

The treatment options for advanced cutaneous T-cell lymphoma (CTCL) are limited because of its unclear pathogenesis. Histone deacetylase (HDAC) inhibitors (HDACis) are recently developed therapeutics approved for refractory CTCL. However, the response rate is relatively low and unpredictable. Previously, we discovered that BCL11B, a key T-cell development regulator, was aberrantly overexpressed in mycosis fungoides, the most common CTCL, as compared with benign inflammatory skin. In this study, we identified a positive correlation between BCL11B expression and sensitivity to HDACi in CTCL lines. BCL11B suppression in BCL11B-high cells induced cell apoptosis by de-repressing apoptotic pathways and showed synergistic effects with suberoylanilide hydroxamic acid (SAHA), a pan-HDACi. Next, we identified the physical interaction and shared downstream genes between BCL11B and HDAC1/2 in CTCL lines. This interaction was essential in the anti-apoptosis effect of BCL11B, and the synergism between BCL11B suppression and HDACi treatment. Further, in clinical samples from 46 mycosis fungoides patients, BCL11B showed increased but varied expression in advanced tumor stage. Analysis of four patients receiving SAHA treatment suggested a positive correlation between BCL11B expression and favorable response to SAHA treatment. In conclusion, BCL11B may serve as a therapeutic target and a useful marker for improving HDACi efficacy in advanced CTCL. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Identification of an epigenetic signature of early mouse liver regeneration that is disrupted by Zn-HDAC inhibition.

PubMed

Huang, Jiansheng; Schriefer, Andrew E; Yang, Wei; Cliften, Paul F; Rudnick, David A

2014-11-01

Liver regeneration has been well studied with hope of discovering strategies to improve liver disease outcomes. Nevertheless, the signals that initiate such regeneration remain incompletely defined, and translation of mechanism-based pro-regenerative interventions into new treatments for hepatic diseases has not yet been achieved. We previously reported the isoform-specific regulation and essential function of zinc-dependent histone deacetylases (Zn-HDACs) during mouse liver regeneration. Those data suggest that epigenetically regulated anti-proliferative genes are deacetylated and transcriptionally suppressed by Zn-HDAC activity or that pro-regenerative factors are acetylated and induced by such activity in response to partial hepatectomy (PH). To investigate these possibilities, we conducted genome-wide interrogation of the liver histone acetylome during early PH-induced liver regeneration in mice using acetyL-histone chromatin immunoprecipitation and next generation DNA sequencing. We also compared the findings of that study to those seen during the impaired regenerative response that occurs with Zn-HDAC inhibition. The results reveal an epigenetic signature of early liver regeneration that includes both hyperacetylation of pro-regenerative factors and deacetylation of anti-proliferative and pro-apoptotic genes. Our data also show that administration of an anti-regenerative regimen of the Zn-HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) not only disrupts gene-specific pro-regenerative changes in liver histone deacetylation but also reverses PH-induced effects on histone hyperacetylation. Taken together, these studies offer new insight into and suggest novel hypotheses about the epigenetic mechanisms that regulate liver regeneration.

Histone deacetylase inhibitors: Potential in cancer therapy.

PubMed

Marks, P A; Xu, W-S

2009-07-01

The role of histone deacetylases (HDAC) and the potential of these enzymes as therapeutic targets for cancer, neurodegenerative diseases and a number of other disorders is an area of rapidly expanding investigation. There are 18 HDACs in humans. These enzymes are not redundant in function. Eleven of the HDACs are zinc dependent, classified on the basis of homology to yeast HDACs: Class I includes HDACs 1, 2, 3, and 8; Class IIA includes HDACs 4, 5, 7, and 9; Class IIB, HDACs 6 and 10; and Class IV, HDAC 11. Class III HDACs, sirtuins 1-7, have an absolute requirement for NAD(+), are not zinc dependent and generally not inhibited by compounds that inhibit zinc dependent deacetylases. In addition to histones, HDACs have many nonhistone protein substrates which have a role in regulation of gene expression, cell proliferation, cell migration, cell death, and angiogenesis. HDAC inhibitors (HDACi) have been discovered of different chemical structure. HDACi cause accumulation of acetylated forms of proteins which can alter their structure and function. HDACi can induce different phenotypes in various transformed cells, including growth arrest, apoptosis, reactive oxygen species facilitated cell death and mitotic cell death. Normal cells are relatively resistant to HDACi induced cell death. Several HDACi are in various stages of development, including clinical trials as monotherapy and in combination with other anti-cancer drugs and radiation. The first HDACi approved by the FDA for cancer therapy is suberoylanilide hydroxamic acid (SAHA, vorinostat, Zolinza), approved for treatment of cutaneous T-cell lymphoma. 2009 Wiley-Liss, Inc.

Repression of PDGF-R-α after cellular injury involves TNF-α, formation of a c-Fos-YY1 complex, and negative regulation by HDAC.

PubMed

Zhang, Ning; Chan, Cecilia W S; Sanchez-Guerrero, Estella; Khachigian, Levon M

2012-06-01

Wound healing is a complex dynamic process involving a variety of cell types, including fibroblasts that express and respond to cytokines and growth factors in the local microenvironment. The mechanisms controlling gene expression after injury at a transcriptional level are poorly understood. Here we show that decreased expression of a key receptor, PDGF-receptor (R)-α, after fibroblast injury is due to the release and paracrine activity of TNF-α. TNF-α inhibits PDGF-R-α expression and this involves formation of a c-Fos-Yin Yang 1 (YY1) complex and histone deacetylase (HDAC) activity. c-Fos, induced by TNF-α, negatively regulates PDGF-R-α transcription. Small interfering RNA (siRNA) targeting c-Fos or the zinc finger transcription factor YY1 inhibits TNF-α suppression of PDGF-R-α expression. Coimmunoprecipitation studies show that TNF-α stimulates the formation of a complex between c-Fos with YY1. Furthermore, chromatin immunoprecipitation (ChIP) analysis reveals the enrichment of c-Fos, YY1, and HDAC-1 at the PDGF-R-α promoter in cells exposed to TNF-α. With suberoylanilide hydroxamic acid (SAHA) and HDAC-1 siRNA, we demonstrate that HDAC mediates TNF-α repression of PDGF-R-α. These findings demonstrate that transcriptional repression of PDGF-R-α after fibroblast injury involves paracrine activity of endogenous TNF-α, the formation of a c-Fos-YY1 complex, and negative regulatory activity by HDAC.

Therapeutic utility and medicinal chemistry of cathepsin C inhibitors.

PubMed

Guay, Daniel; Beaulieu, Christian; Percival, M David

2010-01-01

The lysosomal cysteine protease cathepsin C (Cat C), also known as dipeptidyl peptidase I, activates a number of granule-associated serine proteases with pro-inflammatory and immune functions by removal of their inhibitory N-terminal dipeptides. Thus, Cat C is a therapeutic target for the treatment of a number of inflammatory and autoimmune diseases. Cathepsin C null mice and humans with Cat C loss of function mutations (Papillon-Lefèvre syndrome) show deficiencies in disease-relevant proteases including neutrophil elastase, cathepsin G, chymases and granzymes and the Cat C mice are protected in a number of disease models. Several methodologies have been recently reported for assessing the effects of Cat C inhibitors on serine protease activities in cellular assays and prolonged treatment of rats with a reversible, selective Cat C inhibitor reduced the activity of three leukocyte serine proteases. Nearly all potent and selective Cat C inhibitors described are based on the preferred dipeptide substrates bearing either irreversible (e.g. diazomethylketone, acyloxymethyl ketone, o-acyl hydroxamic acid and vinyl sulfone) or reversible (e.g. semicarbazide, nitrile and cyanamide) electrophilic warheads. While potent and highly selective, the best inhibitors described to date still have poor stability and/or rodent pharmacokinetics, likely resulting from their peptidic nature. The lack of selective compounds with appropriate rodent pharmacokinetic properties has hampered the assessment of the effects of Cat C inhibitors on the activation of disease-relevant proteases in vivo and the full evaluation of the therapeutic utility of Cat C inhibitors.

Adsorption of a novel reagent scheme on scheelite and calcite causing an effective flotation separation.

PubMed

Gao, Yuesheng; Gao, Zhiyong; Sun, Wei; Yin, Zhigang; Wang, Jianjun; Hu, Yuehua

2018-02-15

The efficient separation of scheelite from calcium-bearing minerals, especially calcite, remains a challenge in practice. In this work, a novel reagent scheme incorporating a depressant of sodium hexametaphosphate (SHMP) and a collector mixture of octyl hydroxamic acid (HXMA-8) and sodium oleate (NaOl) was employed in both single and mixed binary mineral flotation, and it proved to be highly effective for the separation. Furthermore, the role of the pH value in the separation was evaluated. Additionally, the mechanism of the selective separation was investigated systemically via zeta potential measurements, fourier transform infrared (FTIR) spectroscopy analysis, X-ray photoelectron (XPS) spectroscopy analysis and crystal chemistry calculations. It turns out that the selective chemisorption of SHMP on calcite (in the form of complexation between H 2 PO 4 - /HPO 4 2- and Ca 2+ ) over scheelite is ascribed to the stronger reactivity and higher density of Ca ions on the commonly exposed surfaces of calcite minerals. The intense adsorption of HXMA-8 on scheelite over calcite due to the match of the OO distances in WO 4 2- of scheelite and CONHOH of HXMA-8 holds the key to the successful separation. We were also interested in warranting the previous claim that NaOl is readily adsorbed on both minerals via chemisorption. Our results provided valuable insights into the application of mixed collectors and an effective depressant for flotation separation. Copyright © 2017 Elsevier Inc. All rights reserved.

Novel histone deacetylase inhibitor N25 exerts anti-tumor effects and induces autophagy in human glioma cells by inhibiting HDAC3

PubMed Central

Sun, Xin-Yuan; Qu, Yue; Ni, An-Ran; Wang, Gui-Xiang; Huang, Wei-Bin; Chen, Zhong-Ping; Lv, Zhu-Fen; Zhang, Song; Lindsay, Holly; Zhao, Sibo; Li, Xiao-Nan; Feng, Bing-Hong

2017-01-01

N25, a novel histone deacetylase inhibitor, was created through structural modification of suberoylanilide hydroxamic acid. To evaluate the anti-tumor activity of N25 and clarify its molecular mechanism of inducing autophagy in glioma cells, we investigated its in vitro anti-proliferative effect and in vivo anticancer effect. Moreover, we detected whether N25 induces autophagy in glioma cells by transmission electron microscope and analyzed the protein expression level of HDAC3, Tip60, LC3 in glioma samples by western blot. We additionally analyzed the protein expression level of HDAC3, Tip60, ULK1 (Atg1), and Beclin-1 (Atg6) after treatment with N25 in glioma cells. Our results showed that the anti-tumor activity of N25 in glioma cells is slightly stronger than SAHA both in vitro and in vivo. We found that N25 induced autophagy, and HDAC3 was significantly elevated and Tip60 and LC3 significantly decreased in glioma samples compared with normal brain tissues. Nevertheless, N25 inhibited HDAC3 and up-regulated the protein expression of Tip60, ULK1 (Atg1), and Beclin-1 (Atg6) after treatment of glioma cells with N25. In conclusion, these data suggest that N25 has striking anti-tumor activity in part due to inhibition of HDAC3. Additionally, N25 may induce autophagy through inhibiting HDAC3. PMID:29088860

Trivalent metal ions based on inorganic compounds with in vitro inhibitory activity of matrix metalloproteinase 13.

PubMed

Wen, Hanyu; Qin, Yuan; Zhong, Weilong; Li, Cong; Liu, Xiang; Shen, Yehua

2016-10-01

Collagenase-3 (MMP-13) inhibitors have attracted considerable attention in recent years and have been developed as a therapeutic target for a variety of diseases, including cancer. Matrix metalloproteinases (MMPs) can be inhibited by a multitude of compounds, including hydroxamic acids. Studies have shown that materials and compounds containing trivalent metal ions, particularly potassium hexacyanoferrate (III) (K3[Fe(CN)6]), exhibit cdMMP-13 inhibitory potential with a half maximal inhibitory concentration (IC50) of 1.3μM. The target protein was obtained by refolding the recombinant histidine-tagged cdMMP-13 using size exclusion chromatography (SEC). The secondary structures of the refolded cdMMP-13 with or without metal ions were further analyzed via circular dichroism and the results indicate that upon binding with metal ions, an altered structure with increased domain stability was obtained. Furthermore, isothermal titration calorimetry (ITC) experiments demonstrated that K3[Fe(CN)6]is able to bind to MMP-13 and endothelial cell tube formation tests provide further evidence for this interaction to exhibit anti-angiogenesis potential. To the best of our knowledge, no previous report of an inorganic compound featuring a MMP-13 inhibitory activity has ever been reported in the literature. Our results demonstrate that K3[Fe(CN)6] is useful as a new effective and specific inhibitor for cdMMP-13 which may be of great potential for future drug screening applications. Copyright © 2016. Published by Elsevier Inc.

Structure and membrane affinity of a suite of amphiphilic siderophores produced by a marine bacterium

PubMed Central

Martinez, Jennifer S.; Carter-Franklin, Jayme N.; Mann, Elizabeth L.; Martin, Jessica D.; Haygood, Margo G.; Butler, Alison

2003-01-01

Iron concentrations in the ocean are low enough to limit the growth of marine microorganisms, which raises questions about the molecular mechanisms these organisms use to acquire iron. Marine bacteria have been shown to produce siderophores to facilitate iron(III) uptake. We describe the structures of a suite of amphiphilic siderophores, named the amphibactins, which are produced by a nearshore isolate, γ Proteobacterium, Vibrio sp. R-10. Each amphibactin has the same Tris-hydroxamate-containing peptidic headgroup composed of three ornithine residues and one serine residue but differs in the acyl appendage, which ranges from C-14 to C-18 and varies in the degree of saturation and hydroxylation. Although amphiphilic siderophores are relatively rare, cell-associated amphiphilic siderophores are even less common. We find that the amphibactins are cell-associated siderophores. As a result of the variation in the nature of the fatty acid appendage and the cellular location of the amphibactins, the membrane partitioning of these siderophores was investigated. The physiological mixture of amphibactins had a range of membrane affinities (3.8 × 103 to 8.3 × 102 M−1) that are larger overall than other amphiphilic siderophores, likely accounting for their cell association. This cell association is likely an important defense against siderophore diffusion in the oceanic environment. The phylogenetic affiliation of Vibrio sp. R-10 is discussed, as well as the observed predominance of amphiphilic siderophores produced by marine bacteria in contrast to those produced by terrestrial bacteria. PMID:12651947

SAHA and S116836, a novel tyrosine kinase inhibitor, synergistically induce apoptosis in imatinib-resistant chronic myelogenous leukemia cells

PubMed Central

Bu, Qiangui; Cui, Lijing; Li, Juan; Du, Xin; Zou, Waiyi; Ding, Ke; Pan, Jingxuan

2014-01-01

Limited treatment options are available for chronic myelogenous leukemia (CML) patients who develop imatinib mesylate (IM) resistance. Here we proposed a novel combination regimen, a co-administration of S116836, a novel small molecule multi-targeted tyrosine kinase inhibitor that was synthesized by rational design, and histone deacetylases inhibitor (HDACi) suberoylanilide hydroxamic acid (SAHA), to overcome IM resistance in CML. S116836 at low concentrations used in the present study mildly downregulates auto-tyrosine phosphorylation of Bcr-Abl. SAHA, an FDA-approved HDACi drug, at 1 μM has modest anti-tumor activity in treating CML. However, we found a synergistic interaction between SAHA and S116836 in Bcr-Abl-positive CML cells that were sensitive or resistant to IM. Exposure of KBM5 and KBM5-T315I cells to minimal or non-toxic concentrations of SAHA and S116836 synergistically reduced cell viability and induced cell death. Co-treatment with SAHA and S116838 repressed the expressions of anti-apoptosis proteins, such as Mcl-1 and XIAP, but promoted Bim expression and mitochondrial damage. Of importance, treatment with both drugs significantly reduced cell viability of primary human CML cells, as compared with either agent alone. Taken together, our findings suggest that SAHA exerts synergistically with S116836 at a non-toxic concentration to promote apoptosis in the CML, including those resistant to imatinib or dasatinib. PMID:24759597

Prediction of operon-like gene clusters in the Arabidopsis thaliana genome based on co-expression analysis of neighboring genes.

PubMed

Wada, Masayoshi; Takahashi, Hiroki; Altaf-Ul-Amin, Md; Nakamura, Kensuke; Hirai, Masami Y; Ohta, Daisaku; Kanaya, Shigehiko

2012-07-15

Operon-like arrangements of genes occur in eukaryotes ranging from yeasts and filamentous fungi to nematodes, plants, and mammals. In plants, several examples of operon-like gene clusters involved in metabolic pathways have recently been characterized, e.g. the cyclic hydroxamic acid pathways in maize, the avenacin biosynthesis gene clusters in oat, the thalianol pathway in Arabidopsis thaliana, and the diterpenoid momilactone cluster in rice. Such operon-like gene clusters are defined by their co-regulation or neighboring positions within immediate vicinity of chromosomal regions. A comprehensive analysis of the expression of neighboring genes therefore accounts a crucial step to reveal the complete set of operon-like gene clusters within a genome. Genome-wide prediction of operon-like gene clusters should contribute to functional annotation efforts and provide novel insight into evolutionary aspects acquiring certain biological functions as well. We predicted co-expressed gene clusters by comparing the Pearson correlation coefficient of neighboring genes and randomly selected gene pairs, based on a statistical method that takes false discovery rate (FDR) into consideration for 1469 microarray gene expression datasets of A. thaliana. We estimated that A. thaliana contains 100 operon-like gene clusters in total. We predicted 34 statistically significant gene clusters consisting of 3 to 22 genes each, based on a stringent FDR threshold of 0.1. Functional relationships among genes in individual clusters were estimated by sequence similarity and functional annotation of genes. Duplicated gene pairs (determined based on BLAST with a cutoff of E<10(-5)) are included in 27 clusters. Five clusters are associated with metabolism, containing P450 genes restricted to the Brassica family and predicted to be involved in secondary metabolism. Operon-like clusters tend to include genes encoding bio-machinery associated with ribosomes, the ubiquitin/proteasome system, secondary metabolic pathways, lipid and fatty-acid metabolism, and the lipid transfer system. Copyright © 2012 Elsevier B.V. All rights reserved.

Therapeutic Drug Monitoring of Asparaginase Activity-Method Comparison of MAAT and AHA Test Used in the International AIEOP-BFM ALL 2009 Trial.

PubMed

Lanvers-Kaminsky, Claudia; Rüffer, Andrea; Würthwein, Gudrun; Gerss, Joachim; Zucchetti, Massimo; Ballerini, Andrea; Attarbaschi, Andishe; Smisek, Petr; Nath, Christa; Lee, Samiuela; Elitzur, Sara; Zimmermann, Martin; Möricke, Anja; Schrappe, Martin; Rizzari, Carmelo; Boos, Joachim

2018-02-01

In the international AIEOP-BFM ALL 2009 trial, asparaginase (ASE) activity was monitored after each dose of pegylated Escherichia coli ASE (PEG-ASE). Two methods were used: the aspartic acid β-hydroxamate (AHA) test and medac asparaginase activity test (MAAT). As the latter method overestimates PEG-ASE activity because it calibrates using E. coli ASE, method comparison was performed using samples from the AIEOP-BFM ALL 2009 trial. PEG-ASE activities were determined using MAAT and AHA test in 2 sets of samples (first set: 630 samples and second set: 91 samples). Bland-Altman analysis was performed on ratios between MAAT and AHA tests. The mean difference between both methods, limits of agreement, and 95% confidence intervals were calculated and compared for all samples and samples grouped according to the calibration ranges of the MAAT and the AHA test. PEG-ASE activity determined using the MAAT was significantly higher than when determined using the AHA test (P < 0.001; Wilcoxon signed-rank test). Within the calibration range of the MAAT (30-600 U/L), PEG-ASE activities determined using the MAAT were on average 23% higher than PEG-ASE activities determined using the AHA test. This complies with the mean difference reported in the MAAT manual. With PEG-ASE activities >600 U/L, the discrepancies between MAAT and AHA test increased. Above the calibration range of the MAAT (>600 U/L) and the AHA test (>1000 U/L), a mean difference of 42% was determined. Because more than 70% of samples had PEG-ASE activities >600 U/L and required additional sample dilution, an overall mean difference of 37% was calculated for all samples (37% for the first and 34% for the second set). Comparison of the MAAT and AHA test for PEG-ASE activity confirmed a mean difference of 23% between MAAT and AHA test for PEG-ASE activities between 30 and 600 U/L. The discrepancy increased in samples with >600 U/L PEG-ASE activity, which will be especially relevant when evaluating high PEG-ASE activities in relation to toxicity, efficacy, and population pharmacokinetics.

Epigenetic regulation of the TRAIL/Apo2L apoptotic pathway by histone deacetylase inhibitors: an attractive approach to bypass melanoma immunotherapy resistance

PubMed Central

Jazirehi, Ali R; Arle, Dylan

2013-01-01

TNF-related apoptosis-inducing ligand (TRAIL/Apo2L) is a major cytotoxic mechanism employed by cytotoxic T lymphocytes (CTL) and natural killer (NK) cells to eradicate malignant cells. TRAIL/Apo2L interacts with its cognate receptors located on tumor cell surface namely, TRAIL-R1 (DR4), TRAIL-R2 (DR5), TRAIL-R3 (DcR1), TRAIL-R4 (DcR2) and osteoprotegerin (OPG). The exact function of DcR1 and DcR2 remains elusive. TRAIL/Apo2L or agonistic monoclonal antibodies directed against TRAIL/Apo2L death-inducing receptors (DR4, DR5) have become an attractive immunological therapeutic tools in clinical oncology due to their selective killing of tumors and lack of affinity towards healthy cells. Though a potent anti-cancer modality, some cancer cells exhibit inherent or acquired resistance to TRAIL/Apo2L. Postulated resistance mechanisms include up-regulation of c-FLIP, down-regulation of caspase-8, down-regulation/shedding of death receptors and an imbalanced ratio of pro- to anti-apoptotic genes due to aberrant activity of cellular survival signal transduction pathways. The development of resistance has spurred the use of combination therapy, in particular using small molecule sensitizing agents, to restore apoptosis sensitivity. A novel category of such compounds is histone deacetylase inhibitors (HDACi), which block HDACs from removing acetyl groups from histone tails thereby preventing silencing of pro-apoptotic genes and regulating the expression of non-histone proteins (i.e., apoptosis-associated genes), are effective agents in some malignancies. Some HDACi, such as Suberoylanilide Hydroxamic Acid (SAHA), have received FDA approval for cancer treatment. In various melanoma preclinical models, HDACi in conjunction with TRAIL/Apo2L, via modulation of apoptotic machinery, have proven to overcome acquired/inherent resistance to either agent. Here, we discuss recent findings on the role of TRAIL/Apo2L and its agonistic mAbs in melanoma immunotherapy with discussions on potential cellular and molecular events by which HDACi can sensitize metastatic melanoma to TRAIL/Apo2L-mediated immune-therapy, thereby, overcoming resistance. PMID:23885325

Aspergillus fumigatus SidA is a highly specific ornithine hydroxylase with bound flavin cofactor.

PubMed

Chocklett, Samuel W; Sobrado, Pablo

2010-08-10

Ferrichrome is a hydroxamate-containing siderophore produced by the pathogenic fungus Aspergillus fumigatus under iron-limiting conditions. This siderophore contains N(5)-hydroxylated l-ornithines essential for iron binding. A. fumigatus siderophore A (Af SidA) catalyzes the flavin- and NADPH-dependent hydroxylation of l-ornithine in ferrichrome biosynthesis. Af SidA was recombinantly expressed and purified as a soluble tetramer and is the first member of this class of flavin monooxygenases to be isolated with a bound flavin cofactor. The enzyme showed typical saturation kinetics with respect to l-ornithine while substrate inhibition was observed at high concentrations of NADPH and NADH. Increasing amounts of hydrogen peroxide were measured as a function of reduced nicotinamide coenzyme concentration, indicating that inhibition was caused by increased uncoupling. Af SidA is highly specific for its amino acid substrate, only hydroxylating l-ornithine. An 8-fold preference in the catalytic efficiency was determined for NADPH compared to NADH. In the absence of substrate, Af SidA can be reduced by NADPH, and a C4a-(hydro)peroxyflavin intermediate is observed. The decay of this intermediate is accelerated by l-ornithine binding. This intermediate was only stabilized by NADPH and not by NADH, suggesting a role for NADP(+) in the stabilization of intermediates in the reaction of Af SidA. NADP(+) is a competitive inhibitor with respect to NADPH, demonstrating that Af SidA forms a ternary complex with NADP(+) and l-ornithine during catalysis. The data suggest that Af SidA likely proceeds by a sequential kinetic mechanism.

A homogeneous cellular histone deacetylase assay suitable for compound profiling and robotic screening.

PubMed

Ciossek, Thomas; Julius, Heiko; Wieland, Heike; Maier, Thomas; Beckers, Thomas

2008-01-01

Most cellular assays that quantify the efficacy of histone deacetylase (HDAC) inhibitors measure hyperacetylation of core histone proteins H3 and H4. Here we describe a new approach, directly measuring cellular HDAC enzymatic activity using the substrate Boc-K(Ac)-7-amino-4-methylcoumarin (AMC). After penetration into HeLa cervical carcinoma or K562 chronic myeloid leukemia cells, the deacetylated product Boc-K-AMC is formed which, after cell lysis, is cleaved by trypsin, finally releasing the fluorophor AMC. The cellular potency of suberoylanilide hydroxamic acid, LBH589, trichostatin A, and MS275 as well-known HDAC inhibitors was determined using this assay. IC(50) values derived from concentration-effect curves correlated well with EC(50) values derived from a cellomics array scan histone H3 hyperacetylation assay. The cellular HDAC activity assay was adapted to a homogeneous format, fully compatible with robotic screening. Concentration-effect curves generated on a Tecan Genesis Freedom workstation were highly reproducible with a signal-to-noise ratio of 5.7 and a Z' factor of 0.88, indicating a very robust assay. Finally, a HDAC-inhibitor focused library was profiled in a medium-throughput screening campaign. Inhibition of cellular HDAC activity correlated well with cytotoxicity and histone H3 hyperacetylation in HeLa cells and with inhibition of human recombinant HDAC1 in a biochemical assay. Thus, by using Boc-K(Ac)-AMC as a cell-permeable HDAC substrate, the activity of various protein lysine-specific deacetylases including HDAC1-containing complexes is measurable in intact cells in a simple and homogeneous manner.

Studies Using an in Vitro Model Show Evidence of Involvement of Epithelial-Mesenchymal Transition of Human Endometrial Epithelial Cells in Human Embryo Implantation*

PubMed Central

Uchida, Hiroshi; Maruyama, Tetsuo; Nishikawa-Uchida, Sayaka; Oda, Hideyuki; Miyazaki, Kaoru; Yamasaki, Akiko; Yoshimura, Yasunori

2012-01-01

Human embryo implantation is a critical multistep process consisting of embryo apposition/adhesion, followed by penetration and invasion. Through embryo penetration, the endometrial epithelial cell barrier is disrupted and remodeled by an unknown mechanism. We have previously developed an in vitro model for human embryo implantation employing the human choriocarcinoma cell line JAR and the human endometrial adenocarcinoma cell line Ishikawa. Using this model we have shown that stimulation with ovarian steroid hormones (17β-estradiol and progesterone, E2P4) and suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, enhances the attachment and adhesion of JAR spheroids to Ishikawa. In the present study we showed that the attachment and adhesion of JAR spheroids and treatment with E2P4 or SAHA individually induce the epithelial-mesenchymal transition (EMT) in Ishikawa cells. This was evident by up-regulation of N-cadherin and vimentin, a mesenchymal cell marker, and concomitant down-regulation of E-cadherin in Ishikawa cells. Stimulation with E2P4 or SAHA accelerated Ishikawa cell motility, increased JAR spheroid outgrowth, and enhanced the unique redistribution of N-cadherin, which was most prominent in proximity to the adhered spheroids. Moreover, an N-cadherin functional blocking antibody attenuated all events but not JAR spheroid adhesion. These results collectively provide evidence suggesting that E2P4- and implanting embryo-induced EMT of endometrial epithelial cells may play a pivotal role in the subsequent processes of human embryo implantation with functional control of N-cadherin. PMID:22174415

Identification of an epigenetic signature of early mouse liver regeneration that is disrupted by Zn-HDAC inhibition

PubMed Central

Huang, Jiansheng; Schriefer, Andrew E; Yang, Wei; Cliften, Paul F; Rudnick, David A

2014-01-01

Liver regeneration has been well studied with hope of discovering strategies to improve liver disease outcomes. Nevertheless, the signals that initiate such regeneration remain incompletely defined, and translation of mechanism-based pro-regenerative interventions into new treatments for hepatic diseases has not yet been achieved. We previously reported the isoform-specific regulation and essential function of zinc-dependent histone deacetylases (Zn-HDACs) during mouse liver regeneration. Those data suggest that epigenetically regulated anti-proliferative genes are deacetylated and transcriptionally suppressed by Zn-HDAC activity or that pro-regenerative factors are acetylated and induced by such activity in response to partial hepatectomy (PH). To investigate these possibilities, we conducted genome-wide interrogation of the liver histone acetylome during early PH-induced liver regeneration in mice using acetyL-histone chromatin immunoprecipitation and next generation DNA sequencing. We also compared the findings of that study to those seen during the impaired regenerative response that occurs with Zn-HDAC inhibition. The results reveal an epigenetic signature of early liver regeneration that includes both hyperacetylation of pro-regenerative factors and deacetylation of anti-proliferative and pro-apoptotic genes. Our data also show that administration of an anti-regenerative regimen of the Zn-HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) not only disrupts gene-specific pro-regenerative changes in liver histone deacetylation but also reverses PH-induced effects on histone hyperacetylation. Taken together, these studies offer new insight into and suggest novel hypotheses about the epigenetic mechanisms that regulate liver regeneration. PMID:25482284

Selective targeting of the repressive transcription factors YY1 and cMyc to disrupt quiescent human immunodeficiency viruses.

PubMed

Barton, Kirston; Margolis, David

2013-02-01

Quiescent HIV-1 infection of resting CD4(+) T cells is an obstacle to eradication of HIV-1 infection. These reservoirs are maintained, in part, by repressive complexes that bind to the HIV-1 long terminal repeat (LTR) and recruit histone deacetylases (HDACs). cMyc and YY1 are two transcription factors that are recruited as part of well-described, distinct complexes to the HIV-1 LTR and in turn recruit HDACs. In prior studies, depletion of single factors that recruit HDAC1 in various cell lines was sufficient to upregulate LTR activity. We used short hairpin RNAs (shRNAs) to test the effect of targeted disruption of a single transcription factor on quiescent proviruses in T cell lines. In this study, we found that depletion of YY1 significantly increases mRNA and protein expression from the HIV-1 promoter in some contexts, but does not affect HDAC1, HDAC2, HDAC3, or acetylated histone 3 occupancy of the HIV-1 LTR. Conversely, depletion of cMyc or cMyc and YY1 does not significantly alter the level of transcription from the LTR or affect recruitment of HDACs to the HIV-1 LTR. Furthermore, global inhibition of HDACs with the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) enhanced the increase in LTR transcription in cells that were depleted of YY1.These findings show that despite prior isolated findings, redundancy in repressors of HIV-1 LTR expression will require selective targeting of multiple restrictive mechanisms to comprehensively induce the escape of quiescent proviruses from latency.

Development of a C3-symmetric benzohydroxamate tripod: Trimetallic complexation with Fe(III), Cr(III) and Al(III)

NASA Astrophysics Data System (ADS)

Baral, Minati; Gupta, Amit; Kanungo, B. K.

2016-06-01

The design, synthesis and physicochemical characterization of a C3-symmetry Benzene-1,3,5-tricarbonylhydroxamate tripod, noted here as BTHA, are described. The chelator was built from a benzene as an anchor, symmetrically extended by three hydroxamate as ligating moieties, each bearing O, O donor sites. A combination of absorption spectrophotometry, potentiometry and theoretical investigations are used to explore the complexation behavior of the ligand with some trivalent metal ions: Fe(III), Cr(III), and Al(III). Three protonation constants were calculated for the ligand in a pH range of 2-11 in a highly aqueous medium (9:1 H2O: DMSO). A high rigidity in the molecular structure restricts the formation of 1:1 (M/L) metal encapsulation but shows a high binding efficiency for a 3:1 metal ligand stoichiometry giving formation constant (in β unit) 28.73, 26.13 and 19.69 for [M3L]; Mdbnd Fe(III), Al(III) and Cr(III) respectively, and may be considered as an efficient Fe-carrier. The spectrophotometric study reveals of interesting electronic transitions occurred during the complexation. BTHA exhibits a peak at 238 nm in acidic pH and with the increase of pH, a new peak appeared at 270 nm. A substantial shifting in both of the peaks in presence of the metal ions implicates a s coordination between ligand and metal ions. Moreover, complexation of BTHA with iron shows three distinct colors, violet, reddish orange and yellow in different pH, enables the ligand to be considered for the use as colorimetric sensor.

Tolerogenic Dendritic Cells Generated by In Vitro Treatment With SAHA Are Not Stable In Vivo.

PubMed

Thewissen, Kristof; Broux, Bieke; Hendriks, Jerome J A; Vanhees, Mandy; Stinissen, Piet; Slaets, Helena; Hellings, Niels

2016-01-01

The aim of this study is to examine whether the histone deacetylase inhibitor, suberoylanilide hydroxamic acid (SAHA), can generate dendritic cells (DCs) with a stable tolerogenic phenotype to counteract autoimmune responses in an animal model of multiple sclerosis. We investigated if the tolerogenic potency of DCs could be increased by continuous treatment during in vitro differentiation toward DCs compared to standard 24-h in vitro treatment of already terminally differentiated DCs. We show that in vitro treatment with SAHA reduces the generation of new CD11c(+) DCs out of mouse bone marrow. SAHA-generated DCs show reduced antigen-presenting function as evidenced by a reduction in myelin endocytosis, a decreased MHC II expression, and a failure to upregulate costimulatory molecules upon LPS challenge. In addition, SAHA-generated DCs display a reduction in proinflammatory cytokines and molecules involved in apoptosis induction, inflammatory migration, and TLR signaling, and they are less immunostimulatory compared to untreated DCs. We demonstrated that the underlying mechanism involves a diminished STAT1 phosphorylation and was independent of STAT6 activation. Although in vitro results were promising, SAHA-generated DCs were not able to alleviate the development of experimental autoimmune encephalomyelitis in mice. In vitro washout experiments demonstrated that the tolerogenic phenotype of SAHA-treated DCs is reversible. Taken together, while SAHA potently boosts tolerogenic properties in DCs during the differentiation process in vitro, SAHA-generated DCs were unable to reduce autoimmunity in vivo. Our results imply that caution needs to be taken when developing DC-based therapies to induce tolerance in the context of autoimmune disease.

Impact of novel histone deacetylase inhibitors, CHAP31 and FR901228 (FK228), on adenovirus-mediated transgene expression.

PubMed

Taura, Kojiro; Yamamoto, Yuzo; Nakajima, Akio; Hata, Koichiro; Uchinami, Hiroshi; Yonezawa, Kei; Hatano, Etsuro; Nishino, Norikazu; Yamaoka, Yoshio

2004-05-01

Histone deacetylase inhibitors (HDIs) are known to enhance adenovirus (Ad)-mediated transgene expression. Recently, novel HDIs, including cyclic hydroxamic-acid-containing peptide 31 (CHAP31) and FR901228 (FK228), have been developed. The effects of these two novel HDIs on Ad-transduced or endogenous gene expression were investigated. Acetylation of core histones and the expression of the coxsackie and adenovirus receptor (CAR) in HDI-treated cells were examined using Western blot and a quantitative reverse transcription polymerase chain reaction (TaqMan RT-PCR), respectively. Their in vivo effect on adenoviral gene expression was investigated in BALB/c mice. Both compounds enhanced and prolonged Ad-mediated beta-galactosidase expression more effectively than did trichostatin A, a classic HDI. The same effect was observed in Ad-transduced heat shock protein 72 (HSP72), but not in hyperthermia-induced endogenous expression of HSP72, suggesting that the effect is specific for transduced gene expression. Hyperacetylation of core histones induced by HDIs was considered responsible for the augmentative effects of gene expression. Intravenous administration of either CHAP31 or FR901228 enhanced beta-galactosidase expression in mice infected with AdLacZ. CHAP31 and FR901228 amplified Ad-mediated transgene expression. The enhancement of transgene expression by HDIs may result in fewer vector doses for necessary gene expression, helping to alleviate disadvantages caused by Ad vectors. This could be a useful tool in overcoming current limitations of gene therapy using adenovirus vectors. Copyright 2004 John Wiley & Sons, Ltd.

Lysine Acetylation in Sexual Stage Malaria Parasites Is a Target for Antimalarial Small Molecules

PubMed Central

Trenholme, Katharine; Marek, Linda; Duffy, Sandra; Pradel, Gabriele; Fisher, Gillian; Hansen, Finn K.; Skinner-Adams, Tina S.; Butterworth, Alice; Ngwa, Che Julius; Moecking, Jonas; Goodman, Christopher D.; McFadden, Geoffrey I.; Sumanadasa, Subathdrage D. M.; Fairlie, David P.; Avery, Vicky M.

2014-01-01

Therapies to prevent transmission of malaria parasites to the mosquito vector are a vital part of the global malaria elimination agenda. Primaquine is currently the only drug with such activity; however, its use is limited by side effects. The development of transmission-blocking strategies requires an understanding of sexual stage malaria parasite (gametocyte) biology and the identification of new drug leads. Lysine acetylation is an important posttranslational modification involved in regulating eukaryotic gene expression and other essential processes. Interfering with this process with histone deacetylase (HDAC) inhibitors is a validated strategy for cancer and other diseases, including asexual stage malaria parasites. Here we confirm the expression of at least one HDAC protein in Plasmodium falciparum gametocytes and show that histone and nonhistone protein acetylation occurs in this life cycle stage. The activity of the canonical HDAC inhibitors trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA; Vorinostat) and a panel of novel HDAC inhibitors on early/late-stage gametocytes and on gamete formation was examined. Several compounds displayed early/late-stage gametocytocidal activity, with TSA being the most potent (50% inhibitory concentration, 70 to 90 nM). In contrast, no inhibitory activity was observed in P. falciparum gametocyte exflagellation experiments. Gametocytocidal HDAC inhibitors caused hyperacetylation of gametocyte histones, consistent with a mode of action targeting HDAC activity. Our data identify HDAC inhibitors as being among a limited number of compounds that target both asexual and sexual stage malaria parasites, making them a potential new starting point for gametocytocidal drug leads and valuable tools for dissecting gametocyte biology. PMID:24733477

Targeting the GPI biosynthetic pathway.

PubMed

Yadav, Usha; Khan, Mohd Ashraf

2018-02-27

The GPI (Glycosylphosphatidylinositol) biosynthetic pathway is a multistep conserved pathway in eukaryotes that culminates in the generation of GPI glycolipid which in turn anchors many proteins (GPI-APs) to the cell surface. In spite of the overall conservation of the pathway, there still exist subtle differences in the GPI pathway of mammals and other eukaryotes which holds a great promise so far as the development of drugs/inhibitors against specific targets in the GPI pathway of pathogens is concerned. Many of the GPI structures and their anchored proteins in pathogenic protozoans and fungi act as pathogenicity factors. Notable examples include GPI-anchored variant surface glycoprotein (VSG) in Trypanosoma brucei, GPI-anchored merozoite surface protein 1 (MSP1) and MSP2 in Plasmodium falciparum, protein-free GPI related molecules like lipophosphoglycans (LPGs) and glycoinositolphospholipids (GIPLs) in Leishmania spp., GPI-anchored Gal/GalNAc lectin and proteophosphoglycans in Entamoeba histolytica or the GPI-anchored mannoproteins in pathogenic fungi like Candida albicans. Research in this active area has already yielded encouraging results in Trypanosoma brucei by the development of parasite-specific inhibitors of GlcNCONH 2 -β-PI, GlcNCONH 2 -(2-O-octyl)-PI and salicylic hydroxamic acid (SHAM) targeting trypanosomal GlcNAc-PI de-N-acetylase as well as the development of antifungal inhibitors like BIQ/E1210/gepinacin/G365/G884 and YW3548/M743/M720 targeting the GPI specific fungal inositol acyltransferase (Gwt1) and the phosphoethanolamine transferase-I (Mcd4), respectively. These confirm the fact that the GPI pathway continues to be the focus of researchers, given its implications for the betterment of human life.

Structures of the Peptidoglycan N-Acetylglucosamine Deacetylase Bc1974 and Its Complexes with Zinc Metalloenzyme Inhibitors.

PubMed

Giastas, Petros; Andreou, Athena; Papakyriakou, Athanasios; Koutsioulis, Dimitris; Balomenou, Stavroula; Tzartos, Socrates J; Bouriotis, Vassilis; Eliopoulos, Elias E

2018-02-06

The cell wall peptidoglycan is recognized as a primary target of the innate immune system, and usually its disintegration results in bacterial lysis. Bacillus cereus, a close relative of the highly virulent Bacillus anthracis, contains 10 polysaccharide deacetylases. Among these, the peptidoglycan N-acetylglucosamine deacetylase Bc1974 is the highest homologue to the Bacillus anthracis Ba1977 that is required for full virulence and is involved in resistance to the host's lysozyme. These metalloenzymes belong to the carbohydrate esterase family 4 (CE4) and are attractive targets for the development of new anti-infective agents. Herein we report the first X-ray crystal structures of the NodB domain of Bc1974, the conserved catalytic core of CE4s, in the unliganded form and in complex with four known metalloenzyme inhibitors and two amino acid hydroxamates that target the active site metal. These structures revealed the presence of two conformational states of a catalytic loop known as motif-4 (MT4), which were not observed previously for peptidoglycan deacetylases, but were recently shown in the structure of a Vibrio clolerae chitin deacetylase. By employing molecular docking of a substrate model, we describe a catalytic mechanism that probably involves initial binding of the substrate in a receptive, more open state of MT4 and optimal catalytic activity in the closed state of MT4, consistent with the previous observations. The ligand-bound structures presented here, in addition to the five Bc1974 inhibitors identified, provide a valuable basis for the design of antibacterial agents that target the peptidoglycan deacetylase Ba1977.

Comparison of histological effects of polydeoxyribonucleic acid and hyaluronic acid in experimentally induced osteoarthritis of the knee joints of rats

PubMed Central

Karahan, Nazım; Arslan, İlyas; Orak, Müfit; Midi, Ahmet; Yücel, İstemi

2017-01-01

Aim: The histological effects of intra-articular polydeoxyribonucleic acid and hyaluronic acid in experimentally induced osteoarthritis of the knee joints of rats were investigated. Methods: Thirty rats were divided into three groups, i.e. polydeoxyribonucleic acid group, hyaluronic acid group and saline group. Osteoarthritis of the knee joints of the rats were induced by acl- transection. The polydeoxyribonucleic group was injected with 100 µg (0.05 cc) polydeoxyribonucleic acid. The hyaluronic acid group was injected with 100 µg (0.05 cc) hyaluronic acid, and the saline group was injected with 50 µl (0.05 cc) of 0.9% sodium chloride solution. All of the rats were sacrificed on day 29 and the right knee joints were prepared, and evaluated histologically by Mankin classification. Findings: The differences in total Mankin scores between the three groups were statistically significant (P < 0.01). The differences in total Mankin scores between the polydeoxyribonucleic acid group and the hyaluronic acid group were statistically significant (P < 0.01). The differences in total Mankin scores between hyaluronic acid group and saline group were statistically significant (P < 0.01). Tidemark continuity in all the specimens of the polydeoxyribonucleic acid group was noteworthy. Conclusion: The present study shows that more chondroprotective effect and less degeneration was observed with intra-articularly delivered polydeoxyribonucleic acid compared to hyaluronic acid and saline solution in the experimentally induced osteoarthritis of the knee joints of rats.

[CONTENT OF TRANS FATTY ACIDS IN FOOD PRODUCTS IN SPAIN].

PubMed

Robledo de Dios, Teresa; Dal Re Saavedra, M Ángeles; Villar Villalba, Carmen; Pérez-Farinós, Napoleón

2015-09-01

trans fatty acids are associated to several health disorders, as ischemic heart disease or diabetes mellitus. to assess the content of trans fatty acids in products in Spain, and the percentage of trans fatty acids respecting total fatty acids. 443 food products were acquired in Spain, and they were classified into groups. The content in fatty acids was analyzed using gas chromatography. Estimates of central tendency and variability of the content of trans fatty acids in each food group were computed (in g of trans fatty acids/100 g of product). The percentage of trans fatty acids respecting total fatty acids was calculated in each group. 443 products were grouped into 42 groups. Median of trans fatty acids was less than 0.55 g / 100 g of product in all groups except one. 83 % of groups had less than 2 % of trans fatty acids, and 71 % of groups had less than 1 %. the content of trans fatty acids in Spain is low, and it currently doesn't play a public health problem. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Thermodynamics of ligand binding to histone deacetylase like amidohydrolase from Bordetella/Alcaligenes.

PubMed

Meyners, Christian; Baud, Matthias G J; Fuchter, Matthew J; Meyer-Almes, Franz-Josef

2014-03-01

Thermodynamic studies on ligand-protein binding have become increasingly important in the process of drug design. In combination with structural data and molecular dynamics simulations, thermodynamic studies provide relevant information about the mode of interaction between compounds and their target proteins and therefore build a sound basis for further drug optimization. Using the example of histone deacetylases (HDACs), particularly the histone deacetylase like amidohydrolase (HDAH) from Bordetella/Alcaligenes, a novel sensitive competitive fluorescence resonance energy transfer-based binding assay was developed and the thermodynamics of interaction of both fluorescent ligands and inhibitors to histone deacetylase like amidohydrolase were investigated. The assay consumes only small amounts of valuable target proteins and is suitable for fast kinetic and mechanistic studies as well as high throughput screening applications. Binding affinity increased with increasing length of aliphatic spacers (n = 4-7) between the hydroxamate moiety and the dansyl head group of ligand probes. Van't Hoff plots revealed an optimum in enthalpy contribution to the free energy of binding for the dansyl-ligand with hexyl spacer. The selectivity in the series of dansyl-ligands against human class I HDAC1 but not class II HDACs 4 and 6 increased with the ratio of ΔH(0)/ΔG(0). The data clearly emphasize the importance of thermodynamic signatures as useful general guidance for the optimization of ligands or rational drug design. Copyright © 2014 John Wiley & Sons, Ltd.

Synthesis and antimalarial evaluation of prodrugs of novel fosmidomycin analogues.

PubMed

Faísca Phillips, Ana Maria; Nogueira, Fátima; Murtinheira, Fernanda; Barros, Maria Teresa

2015-01-01

The continuous development of drug resistance by Plasmodium falciparum, the agent responsible for the most severe forms of malaria, creates the need for the development of novel drugs to fight this disease. Fosmidomycin is an effective antimalarial and potent antibiotic, known to act by inhibiting the enzyme 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR), essential for the synthesis of isoprenoids in eubacteria and plasmodia, but not in humans. In this study, novel constrained cyclic prodrug analogues of fosmidomycin were synthesized. One, in which the hydroxamate function is incorporated into a six-membered ring, was found have higher antimalarial activity than fosmidomycin against the chloroquine and mefloquine resistant P. falciparum Dd2 strain. In addition, it showed very low cytotoxicity against cultured human cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

Strong-acid, carboxyl-group structures in fulvic acid from the Suwannee River, Georgia. 1. Minor structures

USGS Publications Warehouse

Leenheer, J.A.; Wershaw, R. L.; Reddy, M.M.

1995-01-01

An investigation of the strong-acid characteristics (pKa 3.0 or less) of fulvic acid from the Suwannee River, Georgia, was conducted. Quantitative determinations were made for amino acid and sulfur-containing acid structures, oxalate half-ester structures, malonic acid structures, keto acid structures, and aromatic carboxyl-group structures. These determinations were made by using a variety of spectrometric (13C-nuclear magnetic resonance, infrared, and ultraviolet spectrometry) and titrimetric characterizations on fulvic acid or fulvic acid samples that were chemically derivatized to indicate certain functional groups. Only keto acid and aromatic carboxyl-group structures contributed significantly to the strong-acid characteristics of the fulvic acid; these structures accounted for 43% of the strong-acid acidity. The remaining 57% of the strong acids are aliphatic carboxyl groups in unusual and/or complex configurations for which limited model compound data are available.

Characterization and diagenesis of strong-acid carboxyl groups in humic substances

USGS Publications Warehouse

Leenheer, J.A.; Wershaw, R. L.; Brown, G.K.; Reddy, M.M.

2003-01-01

A small fraction of carboxylic acid functional groups in humic substances are exceptionally acidic with pKa values as low as 0.5. A review of acid-group theory eliminated most models and explanations for these exceptionally acidic carboxyl groups. These acidic carboxyl groups in Suwannee River fulvic acid were enriched by a 2-stage fractionation process and the fractions were characterized by elemental, molecular-weight, and titrimetric analyses, and by infrared and 13C- and 1H-nuclear magnetic resonance spectrometry. An average structural model of the most acidic fraction derived from the characterization data indicated a high density of carboxyl groups clustered on oxygen-heterocycle alicyclic rings. Intramolecular H-bonding between adjacent carboxyl groups in these ring structures enhanced stabilization of the carboxylate anion which results in low pKa1 values. The standard, tetrahydrofuran tetracarboxylic acid, was shown to have similar acidity characteristics to the highly acidic fulvic acid fraction. The end products of 3 known diagenetic pathways for the formation of humic substances were shown to result in carboxyl groups clustered on oxygen-heterocycle alicyclic rings.

Selective Extraction of Uranium from Liquid or Supercritical Carbon Dioxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farawila, Anne F.; O'Hara, Matthew J.; Wai, Chien M.

2012-07-31

Current liquid-liquid extraction processes used in recycling irradiated nuclear fuel rely on (1) strong nitric acid to dissolve uranium oxide fuel, and (2) the use of aliphatic hydrocarbons as a diluent in formulating the solvent used to extract uranium. The nitric acid dissolution process is not selective. It dissolves virtually the entire fuel meat which complicates the uranium extraction process. In addition, a solvent washing process is used to remove TBP degradation products, which adds complexity to the recycling plant and increases the overall plant footprint and cost. A liquid or supercritical carbon dioxide (l/sc -CO2) system was designed tomore » mitigate these problems. Indeed, TBP nitric acid complexes are highly soluble in l/sc -CO2 and are capable of extracting uranium directly from UO2, UO3 and U3O8 powders. This eliminates the need for total acid dissolution of the irradiated fuel. Furthermore, since CO2 is easily recycled by evaporation at room temperature and pressure, it eliminates the complex solvent washing process. In this report, we demonstrate: (1) A reprocessing scheme starting with the selective extraction of uranium from solid uranium oxides into a TBP-HNO3 loaded Sc-CO2 phase, (2) Back extraction of uranium into an aqueous phase, and (3) Conversion of recovered purified uranium into uranium oxide. The purified uranium product from step 3 can be disposed of as low level waste, or mixed with enriched uranium for use in a reactor for another fuel cycle. After an introduction on the concept and properties of supercritical fluids, we first report the characterization of the different oxides used for this project. Our extraction system and our online monitoring capability using UV-Vis absorbance spectroscopy directly in sc-CO2 is then presented. Next, the uranium extraction efficiencies and kinetics is demonstrated for different oxides and under different physical and chemical conditions: l/sc -CO2 pressure and temperature, TBP/HNO3 complex used, reductant or complexant used for selectivity, and ionic liquids used as supportive media. To complete the extraction and recovery cycle, we then demonstrate uranium back extraction from the TBP loaded sc-CO2 phase into an aqueous phase and the characterization of the uranium complex formed at the end of this process. Another aspect of this project was to limit proliferation risks by either co-extracting uranium and plutonium, or by leaving plutonium behind by selectively extracting uranium. We report that the former is easily achieved, since plutonium is in the tetravalent or hexavalent oxidation state in the oxidizing environment created by the TBP-nitric acid complex, and is therefore co-extracted. The latter is more challenging, as a reductant or complexant to plutonium has to be used to selectively extract uranium. After undertaking experiments on different reducing or complexing systems (e.g., AcetoHydroxamic Acid (AHA), Fe(II), ascorbic acid), oxalic acid was chosen as it can complex tetravalent actinides (Pu, Np, Th) in the aqueous phase while allowing the extraction of hexavalent uranium in the sc-CO2 phase. Finally, we show results using an alternative media to commonly used aqueous phases: ionic liquids. We show the dissolution of uranium in ionic liquids and its extraction using sc-CO2 with and without the presence of AHA. The possible separation of trivalent actinides from uranium is also demonstrated in ionic liquids using neodymium as a surrogate and diglycolamides as the extractant.« less

Effects of maternal folic acid supplementation on airway remodeling and allergic airway disease development.

PubMed

İscan, Burcin; Tuzun, Funda; Eroglu Filibeli, Berna; Cilekar Micili, Serap; Ergur, Bekir Ugur; Duman, Nuray; Ozkan, Hasan; Kumral, Abdullah

2018-03-27

Maternal folic acid supplementation has been recommended prior to and during the first trimester of pregnancy to reduce the risk of infant neural tube defects. However, an uncertain relationship between folic acid supplementation during pregnancy and development of childhood asthma exists. Recent data show a methyl donor-rich diet could increase the risk of developing allergic airway disease through DNA methylation and aberrant gene transcription. This study evaluated the effect of folic acid supplementation during pregnancy on airway remodeling and allergic airway disease vulnerability in a mouse asthma model. BALB/c mice were divided into four groups according to gestational folic acid supplementation and postnatal ovalbumin (OVA) exposure: Group 1 (whole pregnancy folic acid supplementation + OVA-exposed group), Group 2 (first gestational week folic acid supplementation + OVA-exposed group), Group 3 (no folic acid supplementation + OVA-exposed group), and Group 4 (control group). Offspring were sacrificed on day 45 for immunohistological and ultrastructural tests. In OVA challenged groups, folic acid supplementation led to a thicker epithelial and subepithelial smooth muscle layer than in the unsupplemented group. Moreover, folic acid supplementation during whole pregnancy (Group 1) was associated with a thicker epithelial and subepithelial smooth muscle layer than folic acid supplementation during the first week of pregnancy (Group 2), suggesting a duration-response relationship. Electron microscopic imaging revealed that structural changes including the loss of epithelial integrity, thickening of basement membrane, and subepithelial fibrosis were more prominent in the folic acid supplementation groups. This study suggested that maternal folic acid supplementation during pregnancy affects airway remodeling and increases the allergic responses induced by ovalbumin challenge in offspring. In addition, the effect size increased as the duration and cumulative dose increased.

Metabonomics study on Polygonum multiflorum induced liver toxicity in rats by GC-MS

PubMed Central

Zhang, Yuan; Wang, Nannan; Zhang, Meiling; Diao, Tingting; Tang, Jingyue; Dai, Mingzhu; Chen, Suhong; Lin, Guanyang

2015-01-01

Polygonum multiflorum, a traditional Chinese medicinal herb, is widely used in liver and liver nourishing. Recent years, drug regulatory departments reported that Polygonum multiflorum caused serious adverse reaction in clinic, especially liver injury. In this study, we detected the changes in rat serum and liver tissue metabolites through gas chromatography-mass spectrometry (GC-MS). Mass spectrometry, partial least squares-discriminate analysis (PLS-DA) and other diversified techniques were used to analyze the differences among their metabolites. Compared to the control group, the serum concentrations of L-threonine and serine in water extraction groups increased. The serum concentrations of 9,12-octadecadienoic acid, hexadecanoic acid, oleic acid, D-glucose and octadecanoic acid in alcohol extraction groups increased, while lactic acid decreased to a great extent. For liver tissue, compared to the control group, the concentrations of myo-inositol, oleic acid and cholesterol in water extraction groups increased, while those of hexadecanoic acid, octadecanoic acid, ribitol and butanedioic acid decreased to a great extent. The concentrations of myo-inositol, phosphoric acid, uridine, oleic acid, cholesterol and butanoic acid in alcohol extraction groups increased to a great extent, while those of hexadecanoic acid, octadecanoic acid, ribitol and butanedioic acid decreased. The results indicate that Polygonum multiflorum induces the metabolic disorders of energy metabolism, amino acid and lipid metabolism. What’s more, liver injury of alcohol extraction group was more serious than group of water extraction. PMID:26379894

Effect of the association between citric acid and EDTA on root surface etching.

PubMed

Manzolli Leite, Fabio Renato; Nascimento, Gustavo Giacomelli; Manzolli Leite, Elza Regina; Leite, Amauri Antiquera; Cezar Sampaio, Josá Eduardo

2013-09-01

This study aims to compare the clot stabilization on root surfaces conditioned with citric acid and ethylenediamine-tetraacetic acid (EDTA). Scaled root samples (n = 100) were set in fve groups: group I-control group (saline solution); group II (24% EDTA); group III (25% citric acid); group IV (EDTA + citric acid); group V (citric acid + EDTA). Fifty samples were assessed using the root surface modifcation index (RSMI). The other 50 received a blood drop after conditioning. Clot formation was assessed using blood elements adhesion index (BEAI). A blind examiner evaluated photomicrographs. Statistical analysis considered p < 0.05. Groups-III and G-V attained the best results for RSMI and BEAI in comparison to control. The worst results for clot stabilization were seen in group-II. EDTA employment before citric acid (group-IV) reduced clot formation in comparison to citric acid use alone (group-III). Root conditioning with citric acid alone and before EDTA had the best results for smear layer removal and clot stabilization. EDTA inhibited clot stabilization on root surface and must have a residual activity once it has diminished clot adhesion to root even after citric acid conditioning. Thus, EDTA can be used to neutralize citric acid effects on periodontal cells without affecting clot stabilization. Clinical signifcance: To demonstrate that citric acid use on root surfaces previously affected by periodontal disease may favor clot stabilization and may have a benefcial effect on surgical outcomes. Also, EDTA can be used to neutralize citric acid effects on periodontal cells.

Comparison of folic acid levels in schizophrenic patients and control groups

NASA Astrophysics Data System (ADS)

Arthy, C. C.; Amin, M. M.; Effendy, E.

2018-03-01

Folic acid deficiency is a risk factor for schizophrenia through epidemiology, biochemistry and gene-related studies. Compared with healthy people, schizophrenic patients may have high homocysteine plasma values and homocysteine or low levels of folic acid, which seems to correlate with extrapyramidal motor symptoms caused by neuroleptic therapy and with symptoms of schizophrenia. In this present study, we focus on the difference of folic acid level between schizophrenic patient and control group. The study sample consisted of schizophrenic patients and 14 people in the control group and performed blood sampling to obtain the results of folic acid levels. The folic acid level in both groups was within normal range, but the schizophrenic patient group had lower mean folic acid values of 5.00 ng/ml (sb 1.66), compared with the control group with mean folic acid values of 10.75 ng/ml (sb 4.33). there was the group of the control group had a higher value of folic acid than the schizophrenic group.

Effects of boric acid on the healing of Achilles tendons of rats.

PubMed

Kaymaz, Burak; Gölge, Umut Hatay; Ozyalvaclı, Gulzade; Kömürcü, Erkam; Goksel, Ferdi; Mermerkaya, Musa Ugur; Doral, Mahmut Nedim

2016-12-01

Tendinous lesions are among the most frequent pathologies encountered in sportsmen. The objectives of new treatments are to improve the healing process and reduce the recovery time. Boron plays an important role in the wound repair process by increasing components of extracellular matrix and angiogenesis. This animal study aimed to investigate the effect of boric acid on healing of the Achilles tendon. The right Achilles tendons of 40 rats were completely sectioned, and the rats were randomly divided into five groups. Each group consisted of eight rats. Groups 1 and 2 were oral boric acid groups with the doses of 4 and 8 mg/kg/day boric acid, respectively. Group 3 was the local boric acid group (8 mg/kg boric acid intratendinous injection). Group 4 was administered both oral and local boric acid (8 mg/kg/day orally and 8 mg/kg boric acid intratendinous injection), and group 5 was the control group with no boric acid application. At the end of the fourth week, all the rats were killed and histopathological examination of the Achilles tendon repair site was made. Histopathological examination of the tissue sections revealed more properly oriented collagen fibres, more normal cellular distribution of tenocytes and more properly organized vascular bundles in group 1 and group 2, which were the groups administered oral boric acid. Pathological sum scores of groups 1 and 2 were less than those of the other groups, and the differences between the oral boric acid groups (group 1 and group 2) and the other three groups (groups 3, 4 and 5) were statistically significant (p = 0.001). As boric acid is safe and toxicity even after very high doses is unusual, oral boric acid may be used as an agent to improve the healing process of tendon injuries. However, biomechanical tests should also be performed to show the effect of boric acid on strength and endurance of the tendon before it can be used in clinical practice.

[The effect of 18β-sodium glycyrrhetinic acid on the nasal mucosa epithelial cilia in rat models of allergic rhinitis].

PubMed

Yang, Jing; Xi, Kehu; Gui, Yan; Wang, Youhu; Zhang, Fuhong; Ma, Chunxia; Hong, Hao; Liu, Xiangyi; Meng, Nannan; Zhang, Xiaobing

2015-12-01

To investigate 18β-sodium glycyrrhetinic acid impact on nasal mucosa epithelial cilia in rat models of allergic rhinitis (AR). AR models were established by ovalbumin-induction. Wister rats were randomly divided into groups as normal group, model group, budesonide (0.2 mg/kg) group and sodium glycyrrhetinic acid (20 mg/kg and 40 mg/kg) group after the success of AR models. At 2 weeks and 4 weeks after treatment, the behavioral changes of rats were observed and recorded, and nasal septum mucosae were collected after 2 week and 4 week intervention, and the morphological changes of nasal mucosae were observed by electron microscope. Model group developed typical AR symptoms, the total score in all animals was > 5. With budesonide and sodium glycyrrhetinic acid treatment, the AR symptoms were relieved, and the total scores were reduced significantly (P < 0.01). Compared with the model group: after 2 weeks' intervention, thick mucous secretions on the top of columnar epithelium cilia in rat nasal mucosa was significantly reduced, and cilia adhesion, lodging, shedding were relieved in budesonide group and sodium glycyrrhetinic acid group, the relieve in budesonide group was slightly better than that in sodium glycyrrhetinic acid group; after 4 week intervention, Cilia adhesion, lodging, shedding were completely vanished, and the cilia were ranged in regular direction in budesonide group and sodium glycyrrhetinic acid group. Cilia in sodium glycyrrhetinic acid (20 mg/kg) group was more orderly, smooth than that in budesonide group and sodium glycyrrhetinic acid group (40 mg/kg), and the condition of cilia in sodium glycyrrhetinic acid group (20 mg/kg) was similar to the normal group. 18β-sodium glycyrrhetinic acid is effective to restrain the pathological changes of nasal mucosa cilia in rat models of AR.

The Aspergillus fumigatus siderophore biosynthetic gene sidA, encoding L-ornithine N5-oxygenase, is required for virulence.

PubMed

Hissen, Anna H T; Wan, Adrian N C; Warwas, Mark L; Pinto, Linda J; Moore, Margo M

2005-09-01

Aspergillus fumigatus is the leading cause of invasive mold infection and is a serious problem in immunocompromised populations worldwide. We have previously shown that survival of A. fumigatus in serum may be related to secretion of siderophores. In this study, we identified and characterized the sidA gene of A. fumigatus, which encodes l-ornithine N(5)-oxygenase, the first committed step in hydroxamate siderophore biosynthesis. A. fumigatus sidA codes for a protein of 501 amino acids with significant homology to other fungal l-ornithine N(5)-oxygenases. A stable DeltasidA strain was created by deletion of A. fumigatus sidA. This strain was unable to synthesize the siderophores N',N",N'''-triacetylfusarinine C (TAF) and ferricrocin. Growth of the DeltasidA strain was the same as that of the wild type in rich media; however, the DeltasidA strain was unable to grow in low-iron defined media or media containing 10% human serum unless supplemented with TAF or ferricrocin. No significant differences in ferric reduction activities were observed between the parental strain and the DeltasidA strain, indicating that blocking siderophore secretion did not result in upregulation of this pathway. Unlike the parental strain, the DeltasidA strain was unable to remove iron from human transferrin. A rescued strain (DeltasidA + sidA) was constructed; it produced siderophores and had the same growth as the wild type on iron-limited media. Unlike the wild-type and rescued strains, the DeltasidA strain was avirulent in a mouse model of invasive aspergillosis, indicating that sidA is necessary for A. fumigatus virulence.

Concentration of benzoxazinoids in roots of field-grown wheat (Triticum aestivum L.) varieties.

PubMed

Stochmal, Anna; Kus, Jan; Martyniuk, Stefan; Oleszek, Wieslaw

2006-02-22

Benzoxazinones are naturally occurring secondary metabolites of some Gramineae plants, responsible for their resistance to some pathogenic fungi and for their allelopathic action. Six varieties of winter wheat grown in fields under organic or conventional systems and 11 old accessions were tested for two consecutive seasons and three plant development stages for the concentration in their roots of cyclic hydroxamic acids and their degradation products. This is the first report of six benzoxazinones analyzed in plants grown in the field. An analytical technique employing LC-DAD was used for determination. It was shown that 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one, its degradation product 6-methoxybenzoxazolin-2-one, and the lactam 2-hydroxy-7-methoxy-1,4-benzoxazin-2-one were predominant compounds in all tested samples. Their concentrations significantly differed with plant development stage and season, but no significant differences were found between varieties and between plant cultivation systems. The concentrations of 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA) and its degradation product benzoxazolin-2-one (BOA) were much lower, ranging from 60 to 430 mg/kg of dry matter, depending on accession, stage of development, and season. There was no significant difference found between plants grown in different cultivation systems, but there were significant differences between old and new varieties; concentrations of DIBOA and its derivatives were significantly lower in old accessions. It was concluded that the concentrations of DIBOA and BOA, which are precursors of highly fungicidal 2-aminophenol, 2-amino-3H-phenoxazin-3-one, and 2-acetylamino-3H-phenoxazin-3-one, are theoretically high enough to protect plants against some soilborne pathogens.

Lysine acetylation in sexual stage malaria parasites is a target for antimalarial small molecules.

PubMed

Trenholme, Katharine; Marek, Linda; Duffy, Sandra; Pradel, Gabriele; Fisher, Gillian; Hansen, Finn K; Skinner-Adams, Tina S; Butterworth, Alice; Ngwa, Che Julius; Moecking, Jonas; Goodman, Christopher D; McFadden, Geoffrey I; Sumanadasa, Subathdrage D M; Fairlie, David P; Avery, Vicky M; Kurz, Thomas; Andrews, Katherine T

2014-07-01

Therapies to prevent transmission of malaria parasites to the mosquito vector are a vital part of the global malaria elimination agenda. Primaquine is currently the only drug with such activity; however, its use is limited by side effects. The development of transmission-blocking strategies requires an understanding of sexual stage malaria parasite (gametocyte) biology and the identification of new drug leads. Lysine acetylation is an important posttranslational modification involved in regulating eukaryotic gene expression and other essential processes. Interfering with this process with histone deacetylase (HDAC) inhibitors is a validated strategy for cancer and other diseases, including asexual stage malaria parasites. Here we confirm the expression of at least one HDAC protein in Plasmodium falciparum gametocytes and show that histone and nonhistone protein acetylation occurs in this life cycle stage. The activity of the canonical HDAC inhibitors trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA; Vorinostat) and a panel of novel HDAC inhibitors on early/late-stage gametocytes and on gamete formation was examined. Several compounds displayed early/late-stage gametocytocidal activity, with TSA being the most potent (50% inhibitory concentration, 70 to 90 nM). In contrast, no inhibitory activity was observed in P. falciparum gametocyte exflagellation experiments. Gametocytocidal HDAC inhibitors caused hyperacetylation of gametocyte histones, consistent with a mode of action targeting HDAC activity. Our data identify HDAC inhibitors as being among a limited number of compounds that target both asexual and sexual stage malaria parasites, making them a potential new starting point for gametocytocidal drug leads and valuable tools for dissecting gametocyte biology. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Profiling the anti-protozoal activity of anti-cancer HDAC inhibitors against Plasmodium and Trypanosoma parasites.

PubMed

Engel, Jessica A; Jones, Amy J; Avery, Vicky M; Sumanadasa, Subathdrage D M; Ng, Susanna S; Fairlie, David P; Skinner-Adams, Tina; Andrews, Katherine T

2015-12-01

Histone deacetylase (HDAC) enzymes work together with histone acetyltransferases (HATs) to reversibly acetylate both histone and non-histone proteins. As a result, these enzymes are involved in regulating chromatin structure and gene expression as well as other important cellular processes. HDACs are validated drug targets for some types of cancer, with four HDAC inhibitors clinically approved. However, they are also showing promise as novel drug targets for other indications, including malaria and other parasitic diseases. In this study the in vitro activity of four anti-cancer HDAC inhibitors was examined against parasites that cause malaria and trypanosomiasis. Three of these inhibitors, suberoylanilide hydroxamic acid (SAHA; vorinostat(®)), romidepsin (Istodax(®)) and belinostat (Beleodaq(®)), are clinically approved for the treatment of T-cell lymphoma, while the fourth, panobinostat, has recently been approved for combination therapy use in certain patients with multiple myeloma. All HDAC inhibitors were found to inhibit the growth of asexual-stage Plasmodium falciparum malaria parasites in the nanomolar range (IC50 10-200 nM), while only romidepsin was active at sub-μM concentrations against bloodstream form Trypanosoma brucei brucei parasites (IC50 35 nM). The compounds were found to have some selectivity for malaria parasites compared with mammalian cells, but were not selective for trypanosome parasites versus mammalian cells. All compounds caused hyperacetylation of histone and non-histone proteins in P. falciparum asexual stage parasites and inhibited deacetylase activity in P. falciparum nuclear extracts in addition to recombinant PfHDAC1 activity. P. falciparum histone hyperacetylation data indicate that HDAC inhibitors may differentially affect the acetylation profiles of histone H3 and H4.

Combined treatment with Ad-hTRAIL and DTIC or SAHA is associated with increased mitochondrial-mediated apoptosis in human melanoma cell lines.

PubMed

Lillehammer, Trine; Engesaeter, Birgit O; Prasmickaite, Lina; Maelandsmo, Gunhild M; Fodstad, Oystein; Engebraaten, Olav

2007-06-01

Currently, dacarbazine (DTIC) is the only approved systemic treatment for metastatic malignant melanoma. However, the modest treatment effect encourages studies on novel therapeutic molecules, delivery systems and combination therapies. Full-length TRAIL, delivered from an adenoviral vector (Ad-hTRAIL), was studied in combination with DTIC or the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) in human melanoma cell lines. The cytotoxic potential of the combination treatments was assessed by cell viability measurements and CalcuSyn analysis. Involvement of apoptosis was analyzed by TUNEL staining, mitochondrial membrane potential measurements, and activation and expression levels of caspases and other mediators of apoptosis. Ad-hTRAIL in combination with DTIC or SAHA resulted in additive or synergistic growth inhibition compared to each treatment used as single agent. Both combinations augmented apoptosis, which was mediated through the death receptor (DR) pathway by enhanced activation of caspase-8, and through increased loss of mitochondrial integrity. Provoked cleavage of Bid, which bridges the extrinsic and intrinsic apoptosis pathways, and downregulation of the anti-apoptotic mediators Bcl-X(L), Mcl-1 and XIAP (but not Bcl-2) were critical contributing factors. Increased levels of DR4 and DR5 were not a common underlying mechanism as DTIC did not affect the levels of either of the receptors. However, SAHA-induced expression of DR4 may have reduced the TRAIL resistance in the SKMEL-28 cell line. Administration of Ad-hTRAIL in combination with DTIC or SAHA enhances apoptosis in human melanoma cell lines, and suggests that the therapeutic potential of such treatment strategies should be further evaluated for possible clinical use.

RuvBL2 Is Involved in Histone Deacetylase Inhibitor PCI-24781-Induced Cell Death in SK-N-DZ Neuroblastoma Cells

PubMed Central

Zhan, Qinglei; Tsai, Sauna; Lu, Yonghai; Wang, Chunmei; Kwan, Yiuwa; Ngai, Saiming

2013-01-01

Neuroblastoma is the second most common solid tumor diagnosed during infancy. The survival rate among children with high-risk neuroblastoma is less than 40%, highlighting the urgent needs for new treatment strategies. PCI-24781 is a novel hydroxamic acid-based histone deacetylase (HDAC) inhibitor that has high efficacy and safety for cancer treatment. However, the underlying mechanisms of PCI-24781 are not clearly elucidated in neuroblastoma cells. In the present study, we demonstrated that PCI-24781 treatment significantly inhibited tumor growth at very low doses in neuroblastoma cells SK-N-DZ, not in normal cell line HS-68. However, PCI-24781 caused the accumulation of acetylated histone H3 both in SK-N-DZ and HS-68 cell line. Treatment of SK-N-DZ with PCI-24781 also induced cell cycle arrest in G2/M phase and activated apoptosis signaling pathways via the up-regulation of DR4, p21, p53 and caspase 3. Further proteomic analysis revealed differential protein expression profiles between non-treated and PCI-24781 treated SK-N-DZ cells. Totally 42 differentially expressed proteins were identified by MALDI-TOF MS system. Western blotting confirmed the expression level of five candidate proteins including prohibitin, hHR23a, RuvBL2, TRAP1 and PDCD6IP. Selective knockdown of RuvBL2 rescued cells from PCI-24781-induced cell death, implying that RuvBL2 might play an important role in anti-tumor activity of PCI-24781 in SK-N-DZ cells. The present results provide a new insight into the potential mechanism of PCI-24781 in SK-N-DZ cell line. PMID:23977108

Enzymatic characterization of transglutaminase from Streptomyces mobaraensis DSM 40587 in high salt and effect of enzymatic cross-linking of yak milk proteins on functional properties of stirred yogurt.

PubMed

Zhang, L; Zhang, L; Yi, H; Du, M; Ma, C; Han, X; Feng, Z; Jiao, Y; Zhang, Y

2012-07-01

Streptomyces transglutaminase (TGase) purified from high-salt medium was characterized and applied into yak yogurts. The purified enzyme presented a Michaelis constant of 40.47 mmol and a maximum velocity of 44.44 U/mg of protein for N-carboxybenzoyl-l-glutaminyl-glycine in the hydroxamate procedure. The purified TGase exhibited optimum activity at 55°C and pH 6.0. The enzyme was not stable above 50°C and was stable within a pH range of 5.0 to 10.0 at 4°C for 12h and pH 5.0 to 9.0 at 37°C for 30 min. The TGase activity was not affected by Ca(2+), K(+), Ba(2+), or Na(+), but slightly inhibited by Fe(2+), Mg(2+), and Mn(2+), and strongly by Cu(2+) and Zn(2+). To explore yak milk products, it was used to produce yogurt and TGase was used. It was found that TGase-catalyzed cross-linking was effective in improving functional properties of stirred yak yogurt. Treated yogurt produced a strong acid gel, higher consistency, cohesiveness, index of viscosity, and creamier mouth feel than the untreated product. Furthermore, yak yogurt treated with TGase presented lower wet yak hair or sweat odor, or both. Therefore, TGase can be used to pave the way for exploration of novel yak products to overcome the issues of peculiar wet yak hair or sweat odor, or both. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Triggering autophagic cell death with a di-manganese(II) developmental therapeutic.

PubMed

Slator, Creina; Molphy, Zara; McKee, Vickie; Kellett, Andrew

2017-08-01

There is an unmet need for novel metal-based chemotherapeutics with alternative modes of action compared to clinical agents such as cisplatin and metallo-bleomycin. Recent attention in this field has focused on designing intracellular ROS-mediators as powerful cytotoxins of human cancers and identifying potentially unique toxic mechanisms underpinning their utility. Herein, we report the developmental di-manganese(II) therapeutic [Mn 2 (μ-oda)(phen) 4 (H 2 O) 2 ][Mn 2 (μ-oda)(phen) 4 (oda) 2 ]·4H 2 O (Mn-Oda) induces autophagy-promoted apoptosis in human ovarian cancer cells (SKOV3). The complex was initially identified to intercalate DNA by topoisomerase I unwinding and circular dichroism spectroscopy. Intracellular DNA damage, detected by γH2AX and the COMET assay, however, is not linked to direct Mn-Oda free radical generation, but is instead mediated through the promotion of intracellular reactive oxygen species (ROS) leading to autophagic vacuole formation and downstream nuclear degradation. To elucidate the cytotoxic profile of Mn-Oda, a wide range of biomarkers specific to apoptosis and autophagy including caspase release, mitochondrial membrane integrity, fluorogenic probe localisation, and cell cycle analysis were employed. Through these techniques, the activity of Mn-Oda was compared directly to i.) the pro-apoptotic clinical anticancer drug doxorubicin, ii.) the multimodal histone deacetylase inhibitor suberoyanilide hydroxamic acid, and iii.) the autophagy inducer rapamycin. In conjunction with ROS-specific trapping agents and established inhibitors of autophagy, we have identified autophagy-induction linked to mitochondrial superoxide production, with confocal image analysis of SKOV3 cells further supporting autophagosome formation. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Histone deacetylase inhibitor SAHA mediates mast cell death and epigenetic silencing of constitutively active D816V KIT in systemic mastocytosis.

PubMed

Lyberg, Katarina; Ali, Hani Abdulkadir; Grootens, Jennine; Kjellander, Matilda; Tirfing, Malin; Arock, Michel; Hägglund, Hans; Nilsson, Gunnar; Ungerstedt, Johanna

2017-02-07

Systemic mastocytosis (SM) is a clonal bone marrow disorder, where therapeutical options are limited. Over 90% of the patients carry the D816V point mutation in the KIT receptor that renders this receptor constitutively active. We assessed the sensitivity of primary mast cells (MC) and mast cell lines HMC1.2 (D816V mutated), ROSA (KIT WT) and ROSA (KIT D816V) cells to histone deacetylase inhibitor (HDACi) treatment. We found that of four HDACi, suberoyl anilide hydroxamic acid (SAHA) was the most effective in killing mutated MC. SAHA downregulated KIT, followed by major MC apoptosis. Primary SM patient MC cultured ex vivo were even more sensitive to SAHA than HMC1.2 cells, whereas primary MC from healthy subjects were less affected. There was a correlation between cell death and SM disease severity, where cell death was more pronounced in the case of aggressive SM, with almost 100% cell death among MC from the mast cell leukemia patient. Additionally, ROSA (KIT D816V) was more affected by HDACi than ROSA (KIT WT) cells. Using ChIP qPCR, we found that the level of active chromatin mark H3K18ac/H3 decreased significantly in the KIT region. This epigenetic silencing was seen only in the KIT region and not in control genes upstream and downstream of KIT, indicating that the downregulation of KIT is exerted by specific epigenetic silencing. In conclusion, KIT D816V mutation sensitized MC to HDACi mediated killing, and SAHA may be of value as specific treatment for SM, although the specific mechanism of action requires further investigation.

Histone deacetylase inhibitor SAHA mediates mast cell death and epigenetic silencing of constitutively active D816V KIT in systemic mastocytosis

PubMed Central

Lyberg, Katarina; Ali, Hani Abdulkadir; Grootens, Jennine; Kjellander, Matilda; Tirfing, Malin; Arock, Michel; Hägglund, Hans

2017-01-01

Systemic mastocytosis (SM) is a clonal bone marrow disorder, where therapeutical options are limited. Over 90% of the patients carry the D816V point mutation in the KIT receptor that renders this receptor constitutively active. We assessed the sensitivity of primary mast cells (MC) and mast cell lines HMC1.2 (D816V mutated), ROSA (KIT WT) and ROSA (KIT D816V) cells to histone deacetylase inhibitor (HDACi) treatment. We found that of four HDACi, suberoyl anilide hydroxamic acid (SAHA) was the most effective in killing mutated MC. SAHA downregulated KIT, followed by major MC apoptosis. Primary SM patient MC cultured ex vivo were even more sensitive to SAHA than HMC1.2 cells, whereas primary MC from healthy subjects were less affected. There was a correlation between cell death and SM disease severity, where cell death was more pronounced in the case of aggressive SM, with almost 100% cell death among MC from the mast cell leukemia patient. Additionally, ROSA (KIT D816V) was more affected by HDACi than ROSA (KIT WT) cells. Using ChIP qPCR, we found that the level of active chromatin mark H3K18ac/H3 decreased significantly in the KIT region. This epigenetic silencing was seen only in the KIT region and not in control genes upstream and downstream of KIT, indicating that the downregulation of KIT is exerted by specific epigenetic silencing. In conclusion, KIT D816V mutation sensitized MC to HDACi mediated killing, and SAHA may be of value as specific treatment for SM, although the specific mechanism of action requires further investigation. PMID:28038453

Ab initio study of the binding of Trichostatin A (TSA) in the active site of histone deacetylase like protein (HDLP).

PubMed

Vanommeslaeghe, Kenno; Van Alsenoy, Christian; De Proft, Frank; Martins, José C; Tourwé, Dirk; Geerlings, Paul

2003-08-21

Histone deacetylase (HDAC) inhibitors have recently attracted considerable interest because of their therapeutic potential for the treatment of cell proliferative diseases. An X-ray structure of a very potent inhibitor, Trichostatin A (TSA), bound to HDLP (an HDAC analogue isolated from Aquifex aeolicus), is available. From this structure, an active site model (322 atoms), relevant for the binding of TSA and structural analogues, has been derived, and TSA has been minimized in this active site at HF 3-21G* level. The resulting conformation is in excellent accordance with the X-ray structure, and indicates a deprotonation of the hydroxamic acid in TSA by His 131. Also, a water molecule was minimized in the active site. In addition to a similar deprotonation, in accordance with a possible catalytic mechanism of HDAC as proposed by Finnin et al. (M. S. Finnin, J. R. Donigian, A. Cohen, V. M. Richon, R. A. Rifkind and P. A. Marks, Nature, 1999, 401, 188-193), a displacement of the resulting OH- ion in the active site was observed. Based on these results, the difference in energy of binding between TSA and water was calculated. The resulting value is realistic in respect to experimental binding affinities. Furthermore, the mechanism of action of the His 131-Asp 166 charge relay system was investigated. Although the Asp residue in this motif is known to substantially increase the basicity of the His residue, no proton transfer from His 131 to Asp 166 was observed on binding of TSA or water. However, in the empty protonated active site, this proton transfer does occur.

Sequential treatment of CD34+ cells from patients with primary myelofibrosis with chromatin-modifying agents eliminate JAK2V617F-positive NOD/SCID marrow repopulating cells

PubMed Central

Wang, Xiaoli; Zhang, Wei; Tripodi, Joseph; Lu, Min; Xu, Mingjiang; Najfeld, Vesna; Li, Yan

2010-01-01

Because primary myelofibrosis (PMF) originates at the level of the pluripotent hematopoietic stem cell (HSC), we examined the effects of various therapeutic agents on the in vitro and in vivo behavior of PMF CD34+ cells. Treatment of PMF CD34+ cells with chromatin-modifying agents (CMAs) but not hydroxyurea, Janus kinase 2 (JAK2) inhibitors, or low doses of interferon-α led to the generation of greater numbers of CD34+ chemokine (C-X-C motif) receptor (CXCR)4+ cells, which were capable of migrating in response to chemokine (C-X-C motif) ligand (CXCL)12 and resulted in a reduction in the proportion of hematopoietic progenitor cells (HPCs) that were JAK2V617F+. Furthermore, sequential treatment of PMF CD34+ cells but not normal CD34+ cells with decitabine (5-aza-2′-deoxycytidine [5azaD]), followed by suberoylanilide hydroxamic acid (SAHA; 5azaD/SAHA), or trichostatin A (5azaD/TSA) resulted in a higher degree of apoptosis. Two to 6 months after the transplantation of CMAs treated JAK2V617F+ PMF CD34+ cells into nonobese diabetic/severe combined immunodeficient (SCID)/IL-2Rγnull mice, the percentage of JAK2V617F/JAK2total in human CD45+ marrow cells was dramatically reduced. These findings suggest that both PMF HPCs, short-term and long-term SCID repopulating cells (SRCs), are JAK2V617F+ and that JAK2V617F+ HPCs and SRCs can be eliminated by sequential treatment with CMAs. Sequential treatment with CMAs, therefore, represents a possible effective means of treating PMF at the level of the malignant SRC. PMID:20858855

Differential effects of histone deacetylase inhibitors on cellular drug transporters and their implications for using epigenetic modifiers in combination chemotherapy.

PubMed

Valdez, Benigno C; Li, Yang; Murray, David; Brammer, Jonathan E; Liu, Yan; Hosing, Chitra; Nieto, Yago; Champlin, Richard E; Andersson, Borje S

2016-09-27

HDAC inhibitors, DNA alkylators and nucleoside analogs are effective components of combination chemotherapy. To determine a possible mechanism of their synergism, we analyzed the effects of HDAC inhibitors on the expression of drug transporters which export DNA alkylators. Exposure of PEER lymphoma T-cells to 15 nM romidepsin (Rom) resulted in 40%-50% reduction in mRNA for the drug transporter MRP1 and up to ~500-fold increase in the MDR1 mRNA within 32-48 hrs. MRP1 protein levels concomitantly decreased while MDR1 increased. Other HDAC inhibitors - panobinostat, belinostat and suberoylanilide hydroxamic acid (SAHA) - had similar effects on these transporters. The protein level of MRP1 correlated with cellular resistance to busulfan and chlorambucil, and Rom exposure sensitized cells to these DNA alkylators. The decrease in MRP1 correlated with decreased cellular drug export activity, and increased level of MDR1 correlated with increased export of daunorubicin. A similar decrease in the level of MRP1 protein, and increase in MDR1, were observed when mononuclear cells derived from patients with T-cell malignancies were exposed to Rom. Decreased MRP1 and increased MDR1 expressions were also observed in blood mononuclear cells from lymphoma patients who received SAHA-containing chemotherapy in a clinical trial. This inhibitory effect of HDAC inhibitors on the expression of MRP1 suggests that their synergism with DNA alkylating agents is partly due to decreased efflux of these alkylators. Our results further imply the possibility of antagonistic effects when HDAC inhibitors are combined with anthracyclines and other MDR1 drug ligands in chemotherapy.

Potential non-oncological applications of histone deacetylase inhibitors.

PubMed

Ververis, Katherine; Karagiannis, Tom C

2011-01-01

Histone deacetylase inhibitors have emerged as a new class of anticancer therapeutic drugs. Their clinical utility in oncology stems from their intrinsic cytotoxic properties and combinatorial effects with other conventional cancer therapies. To date, the histone deacetylase inhibitors suberoylanilide hydroxamic acid (Vorinostat, Zolinza®) and depsipeptide (Romidepsin, Istodax®) have been approved by the US Food and Drug Administration for the treatment of refractory cutaneous T-cell lymphoma. Further, there are currently over 100 clinical trials involving the use of histone deacetylase inhibitors in a wide range of solid and hematological malignancies. The therapeutic potential of histone deacetylase inhibitors has also been investigated for numerous other diseases. For example, the cytotoxic properties of histone deacetylase inhibitors are currently being harnessed as a potential treatment for malaria, whereas the efficacy of these compounds for HIV relies on de-silencing latent virus. The anti-inflammatory properties of histone deacetylase inhibitors are the predominant mechanisms for other diseases, such as hepatitis, systemic lupus erythematosus and a wide range of neurodegenerative conditions. Additionally, histone deacetylase inhibitors have been shown to be efficacious in animal models of cardiac hypertrophy and asthma. Broad-spectrum histone deacetylase inhibitors are clinically available and have been used almost exclusively in preclinical systems to date. However, it is emerging that class- or isoform-specific compounds, which are becoming more readily available, may be more efficacious particularly for non-oncological applications. The aim of this review is to provide an overview of the effects and clinical potential of histone deacetylase inhibitors in various diseases. Apart from applications in oncology, the discussion is focused on the potential efficacy of histone deacetylase inhibitors for the treatment of neurodegenerative diseases, cardiac hypertrophy and asthma.

Histone deacetylase inhibitors (HDACIs): multitargeted anticancer agents

PubMed Central

Ververis, Katherine; Hiong, Alison; Karagiannis, Tom C; Licciardi, Paul V

2013-01-01

Histone deacetylase (HDAC) inhibitors are an emerging class of therapeutics with potential as anticancer drugs. The rationale for developing HDAC inhibitors (and other chromatin-modifying agents) as anticancer therapies arose from the understanding that in addition to genetic mutations, epigenetic changes such as dysregulation of HDAC enzymes can alter phenotype and gene expression, disturb homeostasis, and contribute to neoplastic growth. The family of HDAC inhibitors is large and diverse. It includes a range of naturally occurring and synthetic compounds that differ in terms of structure, function, and specificity. HDAC inhibitors have multiple cell type-specific effects in vitro and in vivo, such as growth arrest, cell differentiation, and apoptosis in malignant cells. HDAC inhibitors have the potential to be used as monotherapies or in combination with other anticancer therapies. Currently, there are two HDAC inhibitors that have received approval from the US FDA for the treatment of cutaneous T-cell lymphoma: vorinostat (suberoylanilide hydroxamic acid, Zolinza) and depsipeptide (romidepsin, Istodax). More recently, depsipeptide has also gained FDA approval for the treatment of peripheral T-cell lymphoma. Many more clinical trials assessing the effects of various HDAC inhibitors on hematological and solid malignancies are currently being conducted. Despite the proven anticancer effects of particular HDAC inhibitors against certain cancers, many aspects of HDAC enzymes and HDAC inhibitors are still not fully understood. Increasing our understanding of the effects of HDAC inhibitors, their targets and mechanisms of action will be critical for the advancement of these drugs, especially to facilitate the rational design of HDAC inhibitors that are effective as antineoplastic agents. This review will discuss the use of HDAC inhibitors as multitargeted therapies for malignancy. Further, we outline the pharmacology and mechanisms of action of HDAC inhibitors while discussing the safety and efficacy of these compounds in clinical studies to date. PMID:23459471

Histone deacetylase inhibitors (HDACIs): multitargeted anticancer agents.

PubMed

Ververis, Katherine; Hiong, Alison; Karagiannis, Tom C; Licciardi, Paul V

2013-01-01

Histone deacetylase (HDAC) inhibitors are an emerging class of therapeutics with potential as anticancer drugs. The rationale for developing HDAC inhibitors (and other chromatin-modifying agents) as anticancer therapies arose from the understanding that in addition to genetic mutations, epigenetic changes such as dysregulation of HDAC enzymes can alter phenotype and gene expression, disturb homeostasis, and contribute to neoplastic growth. The family of HDAC inhibitors is large and diverse. It includes a range of naturally occurring and synthetic compounds that differ in terms of structure, function, and specificity. HDAC inhibitors have multiple cell type-specific effects in vitro and in vivo, such as growth arrest, cell differentiation, and apoptosis in malignant cells. HDAC inhibitors have the potential to be used as monotherapies or in combination with other anticancer therapies. Currently, there are two HDAC inhibitors that have received approval from the US FDA for the treatment of cutaneous T-cell lymphoma: vorinostat (suberoylanilide hydroxamic acid, Zolinza) and depsipeptide (romidepsin, Istodax). More recently, depsipeptide has also gained FDA approval for the treatment of peripheral T-cell lymphoma. Many more clinical trials assessing the effects of various HDAC inhibitors on hematological and solid malignancies are currently being conducted. Despite the proven anticancer effects of particular HDAC inhibitors against certain cancers, many aspects of HDAC enzymes and HDAC inhibitors are still not fully understood. Increasing our understanding of the effects of HDAC inhibitors, their targets and mechanisms of action will be critical for the advancement of these drugs, especially to facilitate the rational design of HDAC inhibitors that are effective as antineoplastic agents. This review will discuss the use of HDAC inhibitors as multitargeted therapies for malignancy. Further, we outline the pharmacology and mechanisms of action of HDAC inhibitors while discussing the safety and efficacy of these compounds in clinical studies to date.

Potential non-oncological applications of histone deacetylase inhibitors

PubMed Central

Ververis, Katherine; Karagiannis, Tom C

2011-01-01

Histone deacetylase inhibitors have emerged as a new class of anticancer therapeutic drugs. Their clinical utility in oncology stems from their intrinsic cytotoxic properties and combinatorial effects with other conventional cancer therapies. To date, the histone deacetylase inhibitors suberoylanilide hydroxamic acid (Vorinostat, Zolinza®) and depsipeptide (Romidepsin, Istodax®) have been approved by the US Food and Drug Administration for the treatment of refractory cutaneous T-cell lymphoma. Further, there are currently over 100 clinical trials involving the use of histone deacetylase inhibitors in a wide range of solid and hematological malignancies. The therapeutic potential of histone deacetylase inhibitors has also been investigated for numerous other diseases. For example, the cytotoxic properties of histone deacetylase inhibitors are currently being harnessed as a potential treatment for malaria, whereas the efficacy of these compounds for HIV relies on de-silencing latent virus. The anti-inflammatory properties of histone deacetylase inhibitors are the predominant mechanisms for other diseases, such as hepatitis, systemic lupus erythematosus and a wide range of neurodegenerative conditions. Additionally, histone deacetylase inhibitors have been shown to be efficacious in animal models of cardiac hypertrophy and asthma. Broad-spectrum histone deacetylase inhibitors are clinically available and have been used almost exclusively in preclinical systems to date. However, it is emerging that class- or isoform-specific compounds, which are becoming more readily available, may be more efficacious particularly for non-oncological applications. The aim of this review is to provide an overview of the effects and clinical potential of histone deacetylase inhibitors in various diseases. Apart from applications in oncology, the discussion is focused on the potential efficacy of histone deacetylase inhibitors for the treatment of neurodegenerative diseases, cardiac hypertrophy and asthma. PMID:22046487

Histone Deacetylase Inhibitors Enhance Cytotoxicity Towards Breast Tumors While Preserving the Wound-Healing Function of Adipose-Derived Stem Cells.

PubMed

Koko, Kiavash R; Chang, Shaohua; Hagaman, Ashleigh L; Fromer, Marc W; Nolan, Ryan S; Gaughan, John P; Zhang, Ping; Carpenter, Jeffrey P; Brown, Spencer A; Matthews, Martha; Bird, Dorothy

2017-06-01

Paclitaxel improves the oncologic response of breast cancer resections; however, it may negatively affect the wound-healing potential of human adipose-derived stem cells (hASCs) for fat grafting and reconstructive surgery. Histone deacetylase inhibitors (HDACis) modify the epigenetic regulation of gene expression and stabilize microtubules similarly to paclitaxel, thus, creating a synergistic mechanism of cell cycle arrest. We aim to combine these drugs to enhance cytotoxicity towards breast cancer cells, while preserving the wound-healing function of hASCs for downstream reconstructive applications. Triple negative breast cancer cells (MBA-MB-231) and hASCs (institutional review board-approved clinical isolates) were treated with a standard therapeutic dose of paclitaxel (1.0 μM) or with low-dose paclitaxel (0.1 μM) combined with the HDACi suberoylanilide hydroxamic acid or trichostatin A. Cell viability, gene expression, apoptosis, and wound-healing/migration were measured via methylthiazol tetrazolium assay, quantitative real-time polymerase chain reaction, annexin V assay, and fibroblast scratch assay, respectively. Combined HDACi and low-dose paclitaxel therapy maintained cytotoxicity towards breast cancer cells and preserved adipose-derived stem cell viability. Histone deacetylase inhibitor demonstrated selective anti-inflammatory effects on adipose-derived stem cell gene expression and decreased expression of the proapoptotic gene FAS. Furthermore, HDACi therapy did not increase relative apoptosis within hASCs. A scratch assay demonstrated enhanced wound healing among injured fibroblasts indirectly co-cultured with HDACi-treated hASCs. Combining HDACi with low-dose paclitaxel improved cytotoxicity towards breast cancer cells and preserved hASC viability. Furthermore, enhanced wound healing was observed by improved migration in a fibroblast scratch assay. These results suggest that the addition of HDACi to taxane chemotherapy regimens may improve oncologic results and wound-healing outcomes after reconstructive surgery.

Bile acid composition of gallbladder contents in dogs with gallbladder mucocele and biliary sludge.

PubMed

Kakimoto, Toshiaki; Kanemoto, Hideyuki; Fukushima, Kenjiro; Ohno, Koichi; Tsujimoto, Hajime

2017-02-01

OBJECTIVE To examine bile acid composition of gallbladder contents in dogs with gallbladder mucocele and biliary sludge. ANIMALS 18 dogs with gallbladder mucocele (GBM group), 8 dogs with immobile biliary sludge (i-BS group), 17 dogs with mobile biliary sludge (m-BS group), and 14 healthy dogs (control group). PROCEDURES Samples of gallbladder contents were obtained by use of percutaneous ultrasound-guided cholecystocentesis or during cholecystectomy or necropsy. Concentrations of 15 bile acids were determined by use of highperformance liquid chromatography, and a bile acid compositional ratio was calculated for each group. RESULTS Concentrations of most bile acids in the GBM group were significantly lower than those in the control and m-BS groups. Compositional ratio of taurodeoxycholic acid, which is 1 of 3 major bile acids in dogs, was significantly lower in the GBM and i-BS groups, compared with ratios for the control and m-BS groups. The compositional ratio of taurocholic acid was significantly higher and that of taurochenodeoxycholic acid significantly lower in the i-BS group than in the control group. CONCLUSIONS AND CLINICAL RELEVANCE In this study, concentrations and fractions of bile acids in gallbladder contents were significantly different in dogs with gallbladder mucocele or immobile biliary sludge, compared with results for healthy control dogs. Studies are needed to determine whether changes in bile acid composition are primary or secondary events of gallbladder abnormalities.

Chlorogenic acid from honeysuckle improves hepatic lipid dysregulation and modulates hepatic fatty acid composition in rats with chronic endotoxin infusion.

PubMed

Zhou, Yan; Ruan, Zheng; Wen, Yanmei; Yang, Yuhui; Mi, Shumei; Zhou, Lili; Wu, Xin; Ding, Sheng; Deng, Zeyuan; Wu, Guoyao; Yin, Yulong

2016-03-01

Chlorogenic acid as a natural hydroxycinnamic acid has protective effect for liver. Endotoxin induced metabolic disorder, such as lipid dysregulation and hyperlipidemia. In this study, we investigated the effect of chlorogenic acid in rats with chronic endotoxin infusion. The Sprague-Dawley rats with lipid metabolic disorder (LD group) were intraperitoneally injected endotoxin. And the rats of chlorogenic acid-LD group were daily received chlorogenic acid by intragastric administration. In chlorogenic acid-LD group, the area of visceral adipocyte was decreased and liver injury was ameliorated, as compared to LD group. In chlorogenic acid-LD group, serum triglycerides, free fatty acids, hepatic triglycerides and cholesterol were decreased, the proportion of C20:1, C24:1 and C18:3n-6, Δ9-18 and Δ6-desaturase activity index in the liver were decreased, and the proportion of C18:3n-3 acid was increased, compared to the LD group. Moreover, levels of phosphorylated AMP-activated protein kinase, carnitine palmitoyltransferase-I, and fatty acid β-oxidation were increased in chlorogenic acid-LD group compared to LD rats, whereas levels of fatty acid synthase and acetyl-CoA carboxylase were decreased. These findings demonstrate that chlorogenic acid effectively improves hepatic lipid dysregulation in rats by regulating fatty acid metabolism enzymes, stimulating AMP-activated protein kinase activation, and modulating levels of hepatic fatty acids.

Is ursodeoxycholic acid crucial for ischemia/reperfusion-induced ovarian injury in rat ovary?

PubMed

Akdemir, Ali; Sahin, Cagdas; Erbas, Oytun; Yeniel, Ahmet O; Sendag, Fatih

2015-08-01

Ursodeoxycholic acid is frequently used in cholestatic liver diseases. Also, it protects hepatocytes against oxidative stress induced by hydrophobic bile acids. We investigated the anti-oxidative effect of ursodeoxycholic acid on ischemia/reperfusion injury after ovarian de-torsion in rats. We designed five study groups. Group 1 (n = 6): Sham-operated group; group 2 (n = 6): torsion group; group 3 (n = 6): torsion and ursodeoxycholic acid, group 4 (n = 7): torsion/de-torsion group; and group 5 (n = 7): torsion/de-torsion and ursodeoxycholic acid. After that, ovarian samples were obtained and examined histologically and tissue levels of malondialdehyde were measured. Follicular degeneration, edema and inflammatory cells were significantly decreased in groups 3 and 5 in comparison with groups 2 and 4. Also, groups 4 and 5 were compared in terms of vascular congestion and hemorrhage and these were found to be significantly decreased in group 5. In addition, levels of malondialdehyde were significantly decreased in groups 3 and 5 in comparison with groups 2 and 4. We concluded that ursodeoxycholic acid might be useful to protect the ovary against ischemia and reperfusion injury.

Cytotoxic effects of polybasic acids, poly(alkenoic acid)s, and the monomers with various functional groups on human pulp fibroblasts.

PubMed

Kurata, Shigeaki; Morishita, Kumiko; Kawase, Toshio; Umemoto, Kozo

2011-01-01

This study evaluated the cytotoxicity of various polybasic acids, poly(alkenoic acid)s, and the monomers with various acidic functional groups such as carboxyl, phosphoryl, and sulfo group. The cell growth of fibroblasts cultivated in medium containing polybasic acids and polymers up to the concentration to 5 mmol/L was not significantly different compared with that of control without their acids. On the other hand, the cell growth fibroblasts cultivated in medium containing 1 mmol/L of the monomers with acryloyloxy and phosphoryl or carboxyl group decreased remarkably compared with that of the control and the cells were probably lifeless. Those exposed to the monomers with a ether bond and a carboxyl group or a amide bond and a sulfo group was not significantly different compared with that of control.

Catalytic role of Cu(II) in the reduction of Cr(VI) by citric acid under an irradiation of simulated solar light.

PubMed

Li, Ying; Chen, Cheng; Zhang, Jing; Lan, Yeqing

2015-05-01

The catalytic role of Cu(II) in the reduction of Cr(VI) by citric acid with simulated solar light was investigated. The results demonstrated that Cu(II) could significantly accelerate Cr(VI) reduction and the reaction obeyed to pseudo zero-order kinetics with respect to Cr(VI). The removal of Cr(VI) was related to the initial concentrations of Cu(II), citric acid, and the types of organic acids. The optimal removal of Cr(VI) was achieved at pH 4, and the rates of Cu(II) photocatalytic reduction of Cr(VI) by organic acids were in the order: tartaric acid (two α-OH groups, two -COOH groups)>citric acid (one α-OH group, three -COOH groups)>malic acid (one α-OH group, two -COOH groups)>lactic acid (one α-OH group, one -COOH group)≫succinic acid (two -COOH groups), suggesting that the number of α-OH was the key factor for the reaction, followed by the number of -COOH. The formation of Cu(II)-citric acid complex could generate Cu(I) and radicals through a pathway of metal-ligand-electron transfer, promoting the reduction of Cr(VI). This study is helpful to fully understanding the conversion of Cr(VI) in the existence of both organic acids and Cu(II) with solar light in aquatic environments. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of Tranexamic Acid on Blood Loss and Blood Transfusion Reduction after Total Knee Arthroplasty.

PubMed

Seol, Young-Jun; Seon, Jong-Keun; Lee, Seung-Hun; Jin, Cheng; Prakash, Jatin; Park, Yong-Jin; Song, Eun-Kyoo

2016-09-01

Total knee arthroplasty (TKA) accompanies the risk of bleeding and need for transfusion. There are several methods to reduce postoperative blood loss and blood transfusion. One such method is using tranexamic acid during TKA. The purpose of this study was to confirm whether tranexamic acid reduces postoperative blood loss and blood transfusion after TKA. A total of 100 TKA patients were included in the study. The tranexamic acid group consisted of 50 patients who received an intravenous injection of tranexamic acid. The control included 50 patients who received a placebo injection. The amounts of drainage, postoperative hemoglobin, and transfusion were compared between the groups. The mean amount of drainage was lower in the tranexamic acid group (580.6±355.0 mL) than the control group (886.0±375.5 mL). There was a reduction in the transfusion rate in the tranexamic acid group (48%) compared with the control group (64%). The hemoglobin level was higher in the tranexamic acid group than in the control group at 24 hours postoperatively. The mean units of transfusion were smaller in the tranexamic acid group (0.76 units) than in the control group (1.28 units). Our data suggest that intravenous injection of tranexamic acid decreases the total blood loss and transfusion after TKA.

Effects of two antioxidants; α-lipoic acid and fisetin against diabetic cataract in mice.

PubMed

Kan, Emrah; Kiliçkan, Elif; Ayar, Ahmet; Çolak, Ramis

2015-02-01

The purpose of this study was to determine whether α-lipoic acid and fisetin have protective effects against cataract in a streptozotocin-induced experimental cataract model. Twenty-eight male BALB/C mice were made diabetic by the intraperitoneal administration of streptozotocin (200 mg/kg). Three weeks after induction of diabetes, mice were divided randomly into 4 groups in which each group contained 7 mice; fisetin-treated group (group 1), α-lipoic acid-treated group (group 2), fisetin placebo group (group 3), α-lipoic acid placebo group (group 4). Fisetin and α-lipoic acid were administered intraperitoneally weekly for 5 weeks. Cataract development was assessed at the end of 8 weeks by slit lamp examination, and cataract formation was graded using a scale. All groups developed at least grade 1 cataract formation. In the fisetin-treated group, the cataract stages were significantly lower than in the placebo group (p = 0.02). In the α-lipoic acid-treated group, the cataract stages were lower than in the placebo group but it did not reach to a significant value. Both fisetin and α-lipoic acid had a protective effect on cataract development in a streptozotocin-induced experimental cataract model. The protective effect of fisetin appears as though more effective than α-lipoic acid.

Genetic correlations of mid-infrared-predicted milk fatty acid groups with milk production traits.

PubMed

Fleming, A; Schenkel, F S; Malchiodi, F; Ali, R A; Mallard, B; Sargolzaei, M; Jamrozik, J; Johnston, J; Miglior, F

2018-05-01

The objective of this research was to estimate the genetic correlations between milk mid-infrared-predicted fatty acid groups and production traits in first-parity Canadian Holsteins. Contents of short-chain, medium-chain, long-chain, saturated, and unsaturated fatty acid groupings in milk samples can be predicted using mid-infrared spectral data for cows enrolled in milk recording programs. Predicted fatty acid group contents were obtained for 49,127 test-day milk samples from 10,029 first-parity Holstein cows in 810 herds. Milk yield, fat and protein yield, fat and protein percentage, fat-to-protein ratio, and somatic cell score were also available for these test days. Genetic parameters were estimated for the fatty acid groups and production traits using multiple-trait random regression test day models by Bayesian methods via Gibbs sampling. Three separate 8- or 9-trait analyses were performed, including the 5 fatty acid groups with different combinations of the production traits. Posterior standard deviations ranged from <0.001 to 0.01. Average daily genetic correlations were negative and similar to each other for the fatty acid groups with milk yield (-0.62 to -0.59) and with protein yield (-0.32 to -0.25). Weak and positive average daily genetic correlations were found between somatic cell score and the fatty acid groups (from 0.25 to 0.36). Stronger genetic correlations with fat yield, fat and protein percentage, and fat-to-protein ratio were found with medium-chain and saturated fatty acid groups compared with those with long-chain and unsaturated fatty acid groups. Genetic correlations were very strong between the fatty acid groups and fat percentage, ranging between 0.88 for unsaturated and 0.99 for saturated fatty acids. Daily genetic correlations from 5 to 305 d in milk with milk, protein yield and percentage, and somatic cell score traits showed similar patterns for all fatty acid groups. The daily genetic correlations with fat yield at the beginning of lactation were decreasing for long-chain and unsaturated fatty acid groups and increasing for short-chain fatty acids. Genetic correlations between fat percentage and fatty acids were increasing at the beginning of lactation for short- and medium-chain and saturated fatty acids, but slightly decreasing for long-chain and unsaturated fatty acid groups. These results can be used in defining fatty acid traits and breeding objectives. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Acid-functionalized polyolefin materials and their use in acid-promoted chemical reactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oyola, Yatsandra; Tian, Chengcheng; Bauer, John Christopher

An acid-functionalized polyolefin material that can be used as an acid catalyst in a wide range of acid-promoted chemical reactions, wherein the acid-functionalized polyolefin material includes a polyolefin backbone on which acid groups are appended. Also described is a method for the preparation of the acid catalyst in which a precursor polyolefin is subjected to ionizing radiation (e.g., electron beam irradiation) of sufficient power and the irradiated precursor polyolefin reacted with at least one vinyl monomer having an acid group thereon. Further described is a method for conducting an acid-promoted chemical reaction, wherein an acid-reactive organic precursor is contacted inmore » liquid form with a solid heterogeneous acid catalyst comprising a polyolefin backbone of at least 1 micron in one dimension and having carboxylic acid groups and either sulfonic acid or phosphoric acid groups appended thereto.« less

Solid-supported nitroso hetero Diels-Alder reactions. 1. Acylnitroso dienophiles: scope and limitations.

PubMed

Krchnák, Viktor; Moellmann, Ute; Dahse, Hans-Martin; Miller, Marvin J

2008-01-01

Polymer-supported acylnitroso dienophiles were prepared and used in hetero Diels-Alder (HDA) reactions with a variety of dienes. The transient acylnitroso dienophiles were prepared in situ from immobilized hydroxamates, which were attached to solid supports via several linkers each cleavable by different cleavage reagents, and served for the synthesis of both N-unsubstituted and N-derivatized HDA adducts. Model compounds were used to (i) optimize reaction conditions for solid-supported HDA reactions, (ii) evaluate the outcome of the reactions with various dienes, (iii) compare relative reactivities of dienes, and (iv) assess the stability of HDA adducts toward cleavage conditions typically used in solid-phase syntheses. Cleaved products were submitted to biological assays, and the results are reported. The accompanying paper, focused on complementary arylnitroso HDA reactions, includes a comparison of both HDA reactions.

Molecular binding mechanisms of aqueous cadmium and lead to siderophores, bacteria and mineral surfaces

NASA Astrophysics Data System (ADS)

Mishra, Bhoopesh

Recent studies have shown that diverse groups of bacteria adsorb metals to similar extents and uptake can be modeled using a universal adsorption model. In this study, XAFS has been used to resolve whether binding sites determined for single species systems are responsible for adsorption in more complex natural bacterial assemblages. Results obtained from a series of XAFS experiments on pure Gram positive and Gram negative bacterial strains and consortia of bacteria as a function of pH and Cd loading suggests that every bacterial strain has a complex physiology and they are all slightly different from each other. Nevertheless from the metal adsorption chemistry point of view, the main difference between them lies in the site ratio of three fundamental sites only - carboxyl, phosphoryl and sulfide. Two completely different consortia of bacteria (obtained from natural river water, and soil system with severe organic contamination) were successfully modeled in the pH range 3.4--7.8 using the EXAFS models developed for single species systems. Results thus obtained can potentially have very high impact on the modeling of the complex bacterial systems in realistic geological settings, leading to further refinement and development of robust remediation strategies for metal contamination at macroscopic level. In another study, solution speciation of Pb and Cd with DFO-B has been examined using a combination of techniques (ICP, TOC, thermodynamic modeling and XAFS). Results indicate that Pb does not complex with DFO-B at all until about pH 3.5, but forms a totally caged structure at pH 7.5. At intermediate pH conditions, mixture of species (one and two hydroxamate groups complexed) is formed. Cd on the other hand, does not complex until pH 5, forms intermediate complexes at pH 8 and is totally chelated at pH 9. Further studies were conducted for Pb sorption to mineral surface kaolinite with and without DFO-B. In the absence of DFO-B, results suggest outer sphere and inner sphere sorption of Pb on kaolinite surface at acidic and circumneutral pH conditions respectively. In the presence of DFO-B, bulk sorption studies indicated that Pb sorption is enhanced in the presence of DFO-B around pH 6 and inhibited above pH 6.5. This was confirmed by x-ray fluorescence measurements. Extended XAFS study clearly indicated unwrapping of DFO-B molecule at the surface. Our study has unambiguously recognized it as a "Type A" ternary complex ("Type A" complex means surface-metal-ligand type of interaction). Taken together, bulk adsorption measurements and XAFS experiments represent a powerful approach for determining and modeling metal speciation and adsorption.

Inhibition effects of chlorogenic acid on benign prostatic hyperplasia in mice.

PubMed

Huang, Ya; Chen, Huaguo; Zhou, Xin; Wu, Xingdong; Hu, Enming; Jiang, Zhengmeng

2017-08-15

This study aimed to evaluate the inhibitory effects and explore mechanisms of chlorogenic acid against testosterone-induced benign prostatic hyperplasia (BPH) in mice. Benign prostatic hyperplasia model was induced in experimental groups by daily subcutaneous injections of testosterone propionate (7.5mg/kg/d) consecutively for 14 d. A total of 60 mice were randomly divided into six groups: (Group 1) normal control group, (Group 2) benign prostatic hyperplasia model control group, (Group 3) benign prostatic hyperplasia mice treated with finasteride at a dose of 1mg/kg, (Group 4) benign prostatic hyperplasia mice treated with chlorogenic acid at dose levels of 0.8mg/kg (low dose group), (Group 5) benign prostatic hyperplasia mice treated with chlorogenic acid at dose levels of 1.6mg/kg (medium dose group) and (Group 6) benign prostatic hyperplasia mice treated with chlorogenic acid at dose levels of 3.2mg/kg (high dose group). Animals were sacrificed on the scheduled termination, pick out the eyeball to get blood, then prostates were weighed and prostatic index were determined. Then the serum acid phosphatase (ACP), prostatic acid phosphatase (PACP) and typeⅡ5-alpha-reductase (SRD5A2) levels were measured and observed morphological changes of the prostate. Comparing with benign prostatic hyperplasia model group, the high and medium dose of chlorogenic acid could significantly reduce prostate index and levels of acid phosphatase, prostatic acid phosphatase and typeⅡ5-alpha-reductase (P<0.05 or P<0.01). These findings were supported by histopathological observations of prostate tissues. Histopathological examination also indicated that chlorogenic acid treatment at the high and medium doses inhibited testosterone-induced prostatic hyperplasia. The results indicated that chlorogenic acid exhibited restraining effect on benign prostatic hyperplasia model animals, and its mechanism might be related to inhibit typeⅡ5-alpha reductase activity. Copyright © 2017. Published by Elsevier B.V.

Effect of Tranexamic Acid on Blood Loss and Blood Transfusion Reduction after Total Knee Arthroplasty

PubMed Central

Seol, Young-Jun; Seon, Jong-Keun; Lee, Seung-Hun; Jin, Cheng; Prakash, Jatin; Park, Yong-Jin

2016-01-01

Purpose Total knee arthroplasty (TKA) accompanies the risk of bleeding and need for transfusion. There are several methods to reduce postoperative blood loss and blood transfusion. One such method is using tranexamic acid during TKA. The purpose of this study was to confirm whether tranexamic acid reduces postoperative blood loss and blood transfusion after TKA. Materials and Methods A total of 100 TKA patients were included in the study. The tranexamic acid group consisted of 50 patients who received an intravenous injection of tranexamic acid. The control included 50 patients who received a placebo injection. The amounts of drainage, postoperative hemoglobin, and transfusion were compared between the groups. Results The mean amount of drainage was lower in the tranexamic acid group (580.6±355.0 mL) than the control group (886.0±375.5 mL). There was a reduction in the transfusion rate in the tranexamic acid group (48%) compared with the control group (64%). The hemoglobin level was higher in the tranexamic acid group than in the control group at 24 hours postoperatively. The mean units of transfusion were smaller in the tranexamic acid group (0.76 units) than in the control group (1.28 units). Conclusions Our data suggest that intravenous injection of tranexamic acid decreases the total blood loss and transfusion after TKA. PMID:27595071

Control of Clostridium perfringens-induced necrotic enteritis in broilers by target-released butyric acid, fatty acids and essential oils.

PubMed

Timbermont, L; Lanckriet, A; Dewulf, J; Nollet, N; Schwarzer, K; Haesebrouck, F; Ducatelle, R; Van Immerseel, F

2010-04-01

The efficacy of target-released butyric acid, medium-chain fatty acids (C(6) to C(12) but mainly lauric acid) and essential oils (thymol, cinnamaldehyde, essential oil of eucalyptus) micro-encapsulated in a poly-sugar matrix to control necrotic enteritis was investigated. The minimal inhibitory concentrations of the different additives were determined in vitro, showing that lauric acid, thymol, and cinnamaldehyde are very effective in inhibiting the growth of Clostridium perfringens. The in vivo effects were studied in two trials in an experimental necrotic enteritis model in broiler chickens. In the first trial, four groups of chickens were fed a diet supplemented with butyric acid, with essential oils, with butyric acid in combination with medium-chain fatty acids, or with butyric acid in combination with medium-chain fatty acids and essential oils. In all groups except for the group receiving only butyric acid, a significant decrease in the number of birds with necrotic lesions was found compared with the infected, untreated control group. In the second trial the same products were tested but at a higher concentration. An additional group was fed a diet supplemented with only medium-chain fatty acids. In all groups except for that receiving butyric acid in combination with medium-chain fatty acids and essential oils, a significant decrease in the number of birds with necrotic lesions was found compared with the infected, untreated control group. These results suggest that butyric acid, medium-chain fatty acids and/or essential oils may contribute to the prevention of necrotic enteritis in broilers.

Anti-inflammatory and anti-oxidative effects of alpha-lipoic acid in experimentally induced acute otitis media.

PubMed

Tatar, A; Korkmaz, M; Yayla, M; Gozeler, M S; Mutlu, V; Halici, Z; Uslu, H; Korkmaz, H; Selli, J

2016-07-01

To investigate the anti-inflammatory, anti-oxidative and tissue protective effects, as well as the potential therapeutic role, of alpha-lipoic acid in experimentally induced acute otitis media. Twenty-five guinea pigs were assigned to one of five groups: a control (non-otitis) group, and otitis-induced groups treated with saline, penicillin G, alpha-lipoic acid, or alpha-lipoic acid plus penicillin G. Tissue samples were histologically analysed, and oxidative parameters in tissue samples were measured and compared between groups. The epithelial integrity was better preserved, and histological signs of inflammation and secretory metaplasia were decreased, in all groups compared to the saline treated otitis group. In the alpha-lipoic acid plus penicillin G treated otitis group, epithelial integrity was well preserved and histological findings of inflammation were significantly decreased compared to the saline, penicillin G and alpha-lipoic acid treated otitis groups. The most favourable oxidative parameters were observed in the control group, followed by the alpha-lipoic acid plus penicillin G treated otitis group. Alpha-lipoic acid, with its antioxidant, anti-inflammatory and tissue protective properties, may decrease the clinical sequelae and morbidity associated with acute otitis media.

Comparative Evaluation of Efficacy and Tolerability of Glycolic Acid, Salicylic Mandelic Acid, and Phytic Acid Combination Peels in Melasma.

PubMed

Sarkar, Rashmi; Garg, Vijay; Bansal, Shivani; Sethi, Sumit; Gupta, Chitra

2016-03-01

Melasma is acquired symmetric hypermelanosis characterized by light-to-deep brown pigmentation over cheeks, forehead, upper lip, and nose. Treatment of this condition is difficult and associated with high recurrence rates. Chemical peels have become a popular modality in the treatment of melasma. To compare the therapeutic efficacy and tolerability of glycolic acid (35%) versus salicylic-mandelic (SM) acid (20% salicylic/10% mandelic acid) versus phytic combination peels in Indian patients with melasma. Ninety patients diagnosed with melasma were randomly assigned into 3 groups of 30 patients each. Group A received glycolic acid (GA-35%) peel, Group B received SM acid, and Group C received phytic combination peels. Each group was primed with 4% hydroquinone and 0.05% tretinoin cream for 4 weeks before treatment. Chemical peeling was done after every 14 days in all groups until 12 weeks. Clinical evaluation using melasma area and severity index (MASI) score and photography was recorded at every visit and follow-up was done until 20 weeks. There was a decrease in MASI score in all 3 groups but it was statistically significantly lower in Group A than Group C (p = .00), and it was also statistically significantly lower in Group B than Group C (p = .00) but there was no statistically significant difference between Groups A and B (p = .876). Objective response to treatment evaluated by reduction in MASI scoring after 12 weeks was 62.36% reduction in GA group, 60.98% reduction in SM group, and 44.71% in phytic acid group. It is concluded that GA (35%) and SM acid peels are both equally efficacious and a safe treatment modality for melasma in Indian skin, and are more effective than phytic acid peels. Salicylic-mandelic peels are better tolerated and more suitable for Indian skin.

The effects of α-lipoic acid on aortic injury and hypertension in the rat remnant kidney (5/6 nephrectomy) model.

PubMed

Ergür, Bekir Uğur; Çilaker Mıcılı, Serap; Yılmaz, Osman; Akokay, Pınar

2015-06-01

The present study was designed to investigate the effects of α-lipoic acid on the abdominal aorta and hypertension in a remnant kidney model histomorphometrically, immunohistochemically, and ultrastructurally. We surgically reduced the renal tissue mass to 5/6 by applying a remnant kidney model. The rats were divided into 4 groups: Group 1- control group, Group 2- lipoic acid group, Group 3- 5/6 nephrectomy group, and Group IV: 5/6 nephrectomy+lipoic acid-treated group. Lipoic acid solution 100 mg/kg was administered by oral gavage for 8 weeks to Groups II and IV. At the end of the experiment, systemic mean blood pressure was monitored. Then, aortic tissues were removed and fixed. After routine histological procedures, tissue sections were examined histochemically, immunohistochemically (type I angiotensin receptor, vascular endothelial growth factor, alpha-smooth muscle actin), and ultrastructurally. The blood pressure measurements in 5/6 nephrectomy group were significantly higher compared to other groups. In the 5/6 nephrectomy+lipoic acid group, measured blood pressure values and tunica media thickness were significantly lower than in the 5/6 nephrectomy group. In the 5/6 nephrectomy+lipoic acid group, decreased aortic wall thickness, regularity in the structure of elastic fibrils, and more organized elastic lamellae were seen. The expression of type I angiotensin receptor, vascular endothelial growth factor, alpha-smooth muscle actin in the 5/6 nephrectomy+lipoic acid group was decreased compared to the 5/6 nephrectomy group. In the present study, we found that α-lipoic acid could be a favorable agent for the target organ effects of secondary hypertension.

The utility of uric acid assay in dogs as an indicator of functional hepatic mass.

PubMed

Hill, J M; Leisewitz, A L; Goddard, A

2011-06-01

Uric acid was used as a test for liver disease before the advent of enzymology. Three old studies criticised uric acid as a test of liver function. Uric acid, as an end-product of purine metabolism in the liver, deserved re-evaluation as a liver function test. Serum totalbile acids are widely accepted as the most reliable liver function test. This study compared the ability of serum uric acid concentration to assess liver function with that of serum pre-prandial bile acids in dogs. In addition, due to the renal excretion of uric acid the 2 assays were also compared in a renal disease group. Using a control group of healthy dogs, a group of dogs with congenital vascular liver disease, a group of dogs with non-vascular parenchymal liver diseases and a renal disease group, the ability of uric acid and pre-prandial bile acids was compared to detect reduced functional hepatic mass overall and in the vascular or parenchymal liver disease groups separately. Sensitivities, specificities and predictive value parameters were calculated for each test. The medians of uric acid concentration did not differ significantly between any of the groups, whereas pre-prandial bile acids medians were significantly higher in the liver disease groups compared with the normal and renal disease group of dogs. The sensitivity of uric acid in detecting liver disease overall was 65% while the specificity of uric acid in detecting liver disease overall was 59%. The sensitivity and specificity of uric acid in detecting congenital vascular liver disease was 68% and 59%, respectively. The sensitivity and specificity of uric acid in detecting parenchymal liver disease was 63% and 60%, respectively. The overall positive and negative predictive values for uric acid in detecting liver disease were poor and the data in this study indicated uric acid to be an unreliable test of liver function. In dogs suffering from renal compromise serum uric acid concentrations may increase into the abnormal range due to its renal route of excretion.

Conjugated bile acids in gallbladder bile and serum as potential biomarkers for cholesterol polyps and adenomatous polyps.

PubMed

Zhao, Mei-Fen; Huang, Peng; Ge, Chun-Lin; Sun, Tao; Ma, Zhi-Gang; Ye, Fei-Fei

2016-02-28

To identify conjugated bile acids in gallbladder bile and serum as possible biomarkers for cholesterol polyps (CPs) and adenomatous polyps (APs). Gallbladder bile samples and serum samples were collected from 18 patients with CPs (CP group), 9 patients with APs (AP group), and 20 patients with gallstones (control group) from March to November, 2013. High performance liquid chromatography (HPLC) assay with ultraviolent detection was used to detect the concentration of 8 conjugated bile acids (glycocholic acid, GCA; taurocholic acid, TCA; glycochenodeoxycholic acid, GCDCA; taurochenodeoxycholic acid, TCDCA; glycodeoxycholic acid, GDCA; taurodeoxycholic acid, TDCA; taurolithocholic acid, TLCA; tauroursodeoxycholic acid, TUDCA) in bile samples and serum samples. The diagnostic efficacy of serum GCA, GCDCA and TCDCA was evaluated. These 8 conjugated bile acids in gallbladder bile and serum were completely identified within 10 minutes with good linearity (correlation coefficient: R>0.9900; linearity range: 3.91-500 µg/mL). Among these conjugated bile acids, the levels of gallbladder bile GCDCA and TCDCA in the CP group were significantly higher than those in the AP group (p<0.05). Furthermore, serum GCDCA and TCDCA as well as GCA were significantly higher in the AP group than the CP group (p<0.05). Serum GCDCA alone (≤12 µg/mL) had relatively better diagnostic efficacy than the other conjugated bile acids. The levels of serum GCA, GCDCA and TCDCA may be valuable for differentiation of APs and CPs.

Orthodontic tooth movement and root resorption in ovariectomized rats treated by systemic administration of zoledronic acid.

PubMed

Sirisoontorn, Irin; Hotokezaka, Hitoshi; Hashimoto, Megumi; Gonzales, Carmen; Luppanapornlarp, Suwannee; Darendeliler, M Ali; Yoshida, Noriaki

2012-05-01

The effect of zoledronic acid, a potent and novel bisphosphonate, on tooth movement and orthodontically induced root resorption in osteoporotic animals systemically treated with zoledronic acid as similarly used in postmenopausal patients has not been elucidated. Therefore, this study was undertaken. Fifteen 10-week-old female Wistar rats were divided into 3 groups: ovariectomy, ovariectomy + zoledronic acid, and control. Only the ovariectomy and ovariectomy + zoledronic acid groups underwent ovariectomies. Two weeks after the ovariectomy, zoledronic acid was administered only to the ovariectomy + zoledronic acid group. Four weeks after the ovariectomy, 25-g nickel-titanium closed-coil springs were applied to observe tooth movement and orthodontically induced root resorption. There were significant differences in the amounts of tooth movement and orthodontically induced root resorption between the ovariectomy and the control groups, and also between the ovariectomy and the ovariectomy + zoledronic acid groups. There was no statistically significant difference in tooth movement and orthodontically induced root resorption between the ovariectomy + zoledronic acid and the control groups. Zoledronic acid inhibited significantly more tooth movement and significantly reduced the severity of orthodontically induced root resorption in the ovariectomized rats. The ovariectomy + zoledronic acid group showed almost the same results as did the control group in both tooth movement and orthodontically induced root resorption. Zoledronic acid inhibits excessive orthodontic tooth movement and also reduces the risk of severe orthodontically induced root resorption in ovariectomized rats. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Lactic acid bacteria found in fermented fish in Thailand.

PubMed

Tanasupawat, Somboon; Okada, Sanae; Komagata, Kazuo

1998-06-01

Forty-seven strains of homofermentative rod-shaped and 5 heterofermentative sphere-shaped lactic acid bacteria were isolated from 4 kinds of fermented fish (pla-ra, pla-chom, kung-chom, and hoi-dong) in Thailand. These bacteria were separated into four groups by phenotypic and chemotaxonomic characteristics, including fluorometric DNA-DNA hybridization. Five strains (Group I) contained meso-diaminopimelic acid in the cell wall. Four strains were identified as Lactobacillus pentosus, and one strain was L. plantarum. Tested strains of this group produced DL-lactic acid. The rest of the rod-shaped bacteria, 23 strains (Group II) and 19 strains (Group III), lacked meso-diaminopimelic acid in the cell wall and were identified as L. farciminis and Lactobacillus species, respectively. The tested strains of these groups produced L-lactic acid. The amount of cellular fatty acids of C16:0 and C18:1, and the DNA base compositions were significant for differentiating the strains in Groups II and III. Five strains of cocci in chains (Group IV) produced gas from glucose. The tested strains of this group produced d-lactic acid. They were identified as a Leuconostoc species. The distribution of these bacteria in fermented fish in Thailand is discussed.

Effects of Mucuna pruriens on Free Fatty Acid Levels and Histopathological Changes in the Brains of Rats Fed a High Fructose Diet.

PubMed

Akgun, Bekir; Sarı, Aysel; Ozturk, Sait; Erol, Fatih Serhat; Ozercan, Ibrahim Hanifi; Ulu, Ramazan

2017-01-01

To investigate free fatty acid levels and histopathological changes in the brain of rats fed a high fructose diet (HFrD) and to evaluate the effects of Mucuna pruriens, known to have antidiabetic activity, on these changes. The study comprised 28 mature female Wistar rats. The rats were divided into 4 groups, each included 7 rats. Group 1: control; group 2: fed an HFrD; group 3: fed normal rat chow and M. pruriens; group 4: fed an HFrD and M. pruriens for 6 weeks. At the end of 6 weeks, the rats were decapitated, blood and brain tissues were obtained. Serum glucose and triglyceride levels were measured. Free fatty acid levels were measured in 1 cerebral hemisphere of each rat and histopathological changes in the other. The Mann-Whitney U test was used to compare quantitative continuous data between 2 independent groups, and the Kruskal-Wallis test was used to compare quantitative continuous data between more than 2 independent groups. Arachidonic acid and docosahexaenoic acid levels were significantly higher in group 2 than in group 1 (p < 0.05). Free arachidonic acid and docosahexaenoic acid levels in group 4 were significantly less than in group 2 (p < 0.05). Histopathological examination of group 2 revealed extensive gliosis, neuronal hydropic degeneration, and edema. In group 4, gliosis was much lighter than in group 2, and edema was not observed. Neuronal structures in group 4 were similar to those in group 1. The HFrD increased the levels of free arachidonic acid and docosahexaenoic acid probably due to membrane degradation resulting from possible oxidative stress and inflammation in the brain. The HFrD also caused extensive gliosis, neuronal hydropic degeneration, and edema. Hence, M. pruriens could have therapeutic effects on free fatty acid metabolism and local inflammatory responses in the brains of rats fed an HFrD. © 2017 The Author(s) Published by S. Karger AG, Basel.

Effects of Mucuna pruriens on Free Fatty Acid Levels and Histopathological Changes in the Brains of Rats Fed a High Fructose Diet

PubMed Central

Akgun, Bekir; Sarı, Aysel; Ozturk, Sait; Erol, Fatih Serhat; Ozercan, Ibrahim Hanifi; Ulu, Ramazan

2018-01-01

Objective To investigate free fatty acid levels and histopathological changes in the brain of rats fed a high fructose diet (HFrD) and to evaluate the effects of Mucuna pruriens, known to have antidiabetic activity, on these changes. Materials and Methods The study comprised 28 mature female Wistar rats. The rats were divided into 4 groups, each included 7 rats. Group 1: control; group 2: fed an HFrD; group 3: fed normal rat chow and M. pruriens; group 4: fed an HFrD and M. pruriens for 6 weeks. At the end of 6 weeks, the rats were decapitated, blood and brain tissues were obtained. Serum glucose and triglyceride levels were measured. Free fatty acid levels were measured in 1 cerebral hemisphere of each rat and histopathological changes in the other. The Mann-Whitney U test was used to compare quantitative continuous data between 2 independent groups, and the Kruskal-Wallis test was used to compare quantitative continuous data between more than 2 independent groups. Results Arachidonic acid and docosahexaenoic acid levels were significantly higher in group 2 than in group 1 (p < 0.05). Free arachidonic acid and docosahexaenoic acid levels in group 4 were significantly less than in group 2 (p < 0.05). Histopathological examination of group 2 revealed extensive gliosis, neuronal hydropic degeneration, and edema. In group 4, gliosis was much lighter than in group 2, and edema was not observed. Neuronal structures in group 4 were similar to those in group 1. Conclusions The HFrD increased the levels of free arachidonic acid and docosahexaenoic acid probably due to membrane degradation resulting from possible oxidative stress and inflammation in the brain. The HFrD also caused extensive gliosis, neuronal hydropic degeneration, and edema. Hence, M. pruriens could have therapeutic effects on free fatty acid metabolism and local inflammatory responses in the brains of rats fed an HFrD. PMID:28898884

Study of the acid-base properties of mineral soil horizons using pK spectroscopy

NASA Astrophysics Data System (ADS)

Shamrikova, E. V.; Vanchikova, E. V.; Ryazanov, M. A.

2007-11-01

The presence of groups 4 and 5 participating in acid-base equilibria was revealed in samples from mineral horizons of the gley-podzolic soil of the Komi Republic using pK spectroscopy (the mathematical processing of potentiometric titration curves for plotting the distribution of acid groups according to their pK values). The specific quantity of acid-base sites in soil samples was calculated. The contribution of organic and mineral soil components to the groups of acid-base sites was estimated. The pK values of groups determining the potential, exchangeable, and unexchangeable acidities were found. The heterogeneity of acid components determining different types of soil acidity was revealed.

Effects of alpha lipoic acid, ascorbic acid-6-palmitate, and fish oil on the glutathione, malonaldehyde, and fatty acids levels in erythrocytes of streptozotocin induced diabetic male rats.

PubMed

Yilmaz, Okkeş; Ozkan, Yusuf; Yildirim, Mehmet; Oztürk, A Ihsan; Erşan, Yasemin

2002-01-01

In this research, it has been aimed to evaluate the improvement effects of alpha lipoic acid (ALA), ascorbic acid-6-palmitate (AA6P), fish oil (FO), and their combination (COM) on some biochemical properties in erythrocytes of streptozotocin (STZ)-induced diabetic male rats. According to experimental results, glutathione (GSH) level in erythrocytes decreased in diabetes (P < 0.01), D + ALA, and D + AA6P groups (P < 0.001). Malonaldehyde (MA) level increased in diabetes (P < 0.05), D + FO, and D + COM groups (P < 0.001), but its level in D + AA6P and D + ALA groups was lower in diabetes group (P < 0.01). Total lipid level in diabetes and diabetes plus antioxidant administered groups were higher than control. Total cholesterol level was high in diabetes and D + ALA groups (P < 0.05), but its level reduced in D + FO compared to control and diabetes groups, P < 0.05, < 0.001, respectively. Total triglyceride (TTG) level was high in the D + ALA (P < 0.05) and D + COM (P < 0.001) groups. In contrast, TTG level in blood of diabetes group was higher than diabetes plus antioxidant and FO administered groups (P < 0.001). According to gas chromatography analysis results, while the palmitic acid raised in diabetes group (P < 0.05), stearic acid in D + FO, D + ALA, and diabetes groups was lower than control (P < 0.05), oleic acid reduced in D + COM and D + FO groups, but its level raised in D + AA6P and D + ALA groups (P < 0.01). As the linoleic acid (LA) elevated in ALA + D, D + AA6P, and diabetes groups, linolenic acid level in diabetes, D + AA6P, and D + FO groups was lower than control (P < 0.001). Arachidonic acid (AA) decreased in D + ALA, D+ AA6P, and diabetes groups (P < 0.01), but its level in D + COM and D + FO was higher than control (P < 0.05). Docosahexaenoic acid (DHA) increased in D + AA6P and D + COM (P < 0.05). While the total saturated fatty acid level raised in diabetes group, its level reduced in D + ALA and D + FO groups (P < 0.05). In contrast, total unsaturated fatty acid level in D + ALA and D + FO groups was higher than control (P < 0.05). In conclusion, present data have confirmed that the combination of the ALA, AA6P, and FO have improvement effects on the recycling of GSSG to reduced GSH in erythrocytes of diabetic rats, and in addition to this, oxidative stress was suppressed by ALA and AA6P, and unsaturated fatty acid degree was raised by the effects of ALA and FO. Copyright 2002 Wiley-Liss, Inc.

Evaluation of the efficacy and safety of combinations of hydroquinone, glycolic acid, and hyaluronic acid in the treatment of melasma.

PubMed

Ibrahim, Zeinab A; Gheida, Shereen F; El Maghraby, Gamal M; Farag, Zeinab E

2015-06-01

Various treatments are currently available for melasma. However, results are often disappointing. 1 To assess the efficacy and safety of combinations of hydroquinone, glycolic acid, and hyaluronic acid in the treatment of melasma after topical application. 2 To evaluate the dermoscopy as a tool in diagnosis and follow-up of melasma treatment. One hundred patients with mild, moderate-to-severe melasma were divided into five groups. Group I (twenty patients were treated with cream formula containing 4% hydroquinone), group II (twenty patients were treated with cream formula containing 4% hydroquinone + 10% glycolic acid), group III (twenty patients were treated with cream formula containing 4% hydroquinone + 0.01% hyaluronic acid), group IV (twenty patients were treated with cream formula containing 4% hydroquinone + 10% glycolic acid + 0.01% hyaluronic acid), and group V (twenty patients were treated with placebo cream). All patients were subjected to dermoscopic examination and digital photographs before and after treatment. The response and side effects were evaluated. Groups I, III, and IV showed highly significant changes in modified Melasma Area and Severity Index (mMASI) score after using the treatment. Group II showed significant change in mMASI score after using the treatment. The side effects were more reported in group II, followed by group IV, followed by group I, followed by group III. There was highly significant difference between the dermoscopic color findings before and after treatment. Vascularization was another dermoscopic finding. A cream formula containing 4% hydroquinone + 10% glycolic acid + 0.01% hyaluronic acid was very effective in treatment of melasma with tolerable side effects. Dermoscope is a valuable noninvasive tool in the diagnosis and follow-up of melasma treatment. © 2015 Wiley Periodicals, Inc.

[Atorvastatin improves reflow after percutaneous coronary intervention in patients with acute ST-segment elevation myocardial infarction by decreasing serum uric acid level].

PubMed

Yan, Ling; Ye, Lu; Wang, Kun; Zhou, Jie; Zhu, Chunjia

2016-05-25

Objective: To investigate the effect of atorvastatin on reflow in patients with acute ST-segment elevation myocardial infarction (STEMI) after percutaneous coronary intervention (PCI) and its relation to serum uric acid levels. Methods: One hundred and fourteen STEMI patients undergoing primary PCI were enrolled and randomly divided into two groups:55 cases received oral atorvastatin 20 mg before PCI (routine dose group) and 59 cases received oral atorvastatin 80 mg before PCI (high dose group). According to the initial serum uric acid level, patients in two groups were further divided into normal uric acid subgroup and hyperuricemia subgroup. The changes of uric acid level and coronary artery blood flow after PCI were observed. Correlations between the decrease of uric acid, the dose of atorvastatin and the blood flow of coronary artery after PCI were analyzed. Results: Serum uric acid levels were decreased after treatment in both groups (all P <0.05), and patients with hyperuricemia showed more significant decrease in serum uric acid level ( P <0.05). Compared with the routine dose group, serum uric acid level in patients with hyperuricemia decreased more significantly in the high dose group ( P <0.05), but no significant difference was observed between patients with normal serum uric acid levels in two groups ( P >0.05). Among 114 patients, there were 19 cases without reflow after PCI (16.7%). In the routine dose group, there were 12 patients without reflow, in which 3 had normal uric acid and 9 had high uric acid levels ( P <0.01). In the high dose group, there were 7 patients without reflow, in which 2 had normal uric acid and 5 had high uric acid ( P <0.05). Logistic regression analysis showed that hyperuricemia was one of independent risk factors for no-reflow after PCI ( OR =1.01, 95% CI :1.01-1.11, P <0.01). The incidence of no-flow after PCI in the routine dose group was 21.8% (12/55), and that in the high dose group was 11.9% (7/59) ( P <0.01). Conclusion: High dose atorvastatin can decrease serum uric acid levels and improve reflow after PCI in patients with STEMI.

The stability of iso-α-acids and reduced iso-α-acids in stored blood specimens.

PubMed

Rodda, Luke N; Gerostamoulos, Dimitri; Drummer, Olaf H

2014-06-01

The long-term stability of the iso-α-acids, and three structurally similar but chemically altered iso-α-acids (known as 'reduced iso-α-acids' and consisting of the rho-, tetrahydro- and hexahydro-iso-α-acid groups) were investigated in whole blood. Pools of blank blood spiked with the four beer-specific ingredient congener groups at two different concentration levels were stored at 20°C, 4°C and -20°C; and extracted in duplicate in weeks 1, 3, 5 and 8, using a previously published method. A loss of 15% of the initial concentration was considered to indicate possible instability and losses greater than 30% demonstrated significant losses. The individual analytes within the four iso-α-acid groups were also measured to determine which iso-α-acids were subject to greater degradation and were responsible for the overall group instability. All four iso-α-acid groups showed significant losses after 8 weeks of storage under room temperature conditions in particularly the natural iso-α-acid group where major losses were observed (96% and 85% losses for low and high concentrations, respectively). Some degradation in all iso-α-acid groups were seen at 4°C samples predominantly due to the 'n' analogs of the groups showing an increased instability in blood. The -20°C storage conditions resulted in minimal changes in concentrations of all analytes. Higher than frozen storage temperatures can result in substantial changes on the stability of the iso-α-acid type groups in blood. The aim of this study was to highlight the stabilities of the IAA analytes in order to assist in the interpretation of IAA in stored blood specimens. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Reduction of the DNA damages, Hepatoprotective Effect and Antioxidant Potential of the Coconut Water, ascorbic and Caffeic Acids in Oxidative Stress Mediated by Ethanol.

PubMed

Bispo, Vanderson S; Dantas, Lucas S; Chaves, Adriano B; Pinto, Isabella F D; Silva, Railmara P DA; Otsuka, Felipe A M; Santos, Rodrigo B; Santos, Aline C; Trindade, Danielle J; Matos, Humberto R

2017-01-01

Hepatic disorders such as steatosis and alcoholic steatohepatitis are common diseases that affect thousands of people around the globe. This study aims to identify the main phenol compounds using a new HPLC-ESI+-MS/MS method, to evaluate some oxidative stress parameters and the hepatoprotective action of green dwarf coconut water, caffeic and ascorbic acids on the liver and serum of rats treated with ethanol. The results showed five polyphenols in the lyophilized coconut water spiked with standards: chlorogenic acid (0.18 µM), caffeic acid (1.1 µM), methyl caffeate (0.03 µM), quercetin (0.08 µM) and ferulic acid (0.02 µM) isomers. In the animals, the activity of the serum γ-glutamyltranspeptidase (γ-GT) was reduced to 1.8 I.U/L in the coconut water group, 3.6 I.U/L in the ascorbic acid group and 2.9 I.U/L in the caffeic acid groups, when compared with the ethanol group (5.1 I.U/L, p<0.05). Still in liver, the DNA analysis demonstrated a decrease of oxidized bases compared to ethanol group of 36.2% and 48.0% for pretreated and post treated coconut water group respectively, 42.5% for the caffeic acid group, and 34.5% for the ascorbic acid group. The ascorbic acid was efficient in inhibiting the thiobarbituric acid reactive substances (TBARS) in the liver by 16.5% in comparison with the ethanol group. These data indicate that the green dwarf coconut water, caffeic and ascorbic acids have antioxidant, hepatoprotective and reduced DNA damage properties, thus decreasing the oxidative stress induced by ethanol metabolism.

Ascorbic acid and melatonin reduce heat-induced performance inhibition and oxidative stress in Japanese quails.

PubMed

Sahin, N; Onderci, M; Sahin, K; Gursu, M F; Smith, M O

2004-02-01

1. The effects of ascorbic acid (L-ascorbic acid) and melatonin supplementation on performance, carcase characteristics, malondialdehyde (MDA) as lipid peroxidation indicator, ascorbic acid, retinol, tocopherol and mineral status in the Japanese quail (Coturnix coturnix japonica) exposed to high ambient temperature were evaluated. 2. Two hundred and forty Japanese quails (10 d old) were randomly assigned to 8 treatment groups consisting of 10 replicates of three birds each. The birds were kept in a temperature-controlled room at 22 degrees C (Thermoneutral, TN groups) or 34 degrees C (for 8 h/d; 09:00 to 17:00 h; Heat stress, HS groups). Birds in both TN and HS were fed either a basal (control) diet or the basal diet supplemented with 250 mg of L-ascorbic acid/kg of diet (Ascorbic acid group), 40 mg of melatonin/kg of diet (Melatonin group) or both (Ascorbic acid + Melatonin group). 3. Supplementing heat-stressed quails with ascorbic acid and melatonin improved performance compared with the control group. Effects generally were greatest in quails supplemented with both ascorbic acid and melatonin. 4. Although supplementation did not consistently restore the concentrations of serum ascorbic acid, retinol and tocopherol to those of TN groups, these concentrations increased significantly with supplementation. Furthermore, serum and liver MDA and serum cholesterol and glucose concentrations were lower in the supplemented groups than in the heat-stressed controls. 5. Within each environment, excretion of Ca, P, Mg, Zn, Fe and Cr were lowest in the combination group and, in all cases, highest in the HS group. Interactions between diet and temperature were detected for live weight gain, cold carcase weight, MDA, ascorbic acid, tocopherol concentrations and excretion of zinc. 6. The results of the study indicate that ascorbic acid and melatonin supplementation attenuate the decline in performance and antioxidant and mineral status caused by heat stress and such supplementation may offer protection against heat-stress-related depression in performance of Japanese quails.

An impact of the diet on serum fatty acid and lipid profiles in Polish vegetarian children and children with allergy.

PubMed

Gorczyca, D; Paściak, M; Szponar, B; Gamian, A; Jankowski, A

2011-02-01

Vegetarian diet has become an increasing trend in western world and in Poland. The frequency of allergies is growing, and the effectiveness of vegetarian diet in allergic diseases is a concern for research. We aimed to study an effect of vegetarian diet on lipid profile in serum in a group of Polish children in Poland and to investigate lipid parameters in healthy vegetarian children and in omnivorous children with diagnosed atopic disease. Serum lipid profiles (triglycerides, total cholesterol, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, fatty acids) were assessed in groups of children: healthy vegetarians (n=24) and children with diagnosed atopic diseases (n=16), with control group of healthy omnivores (n=18). Diet classification was assessed by a questionnaire. No differences were observed in serum triglycerides, LDL cholesterol and saturated and monounsaturated fatty acids level in all groups. In the group of Polish vegetarian children, we recorded high consumption of vegetable oils rich in monounsaturated fatty acid, and sunflower oil containing linoleic acid. This observation was associated with higher content of linoleic acid in serum in this group. Among polyunsaturated n-6 fatty acids, linoleic acid revealed significantly (P<0.05) lower levels in allergy vs vegetarian groups. In case of eicosapentaenoic acid (n-3 fatty acid), the allergy group showed higher levels of this compound in comparison to vegetarians. Significantly higher concentration of linoleic acid in vegetarian children in comparison to allergy group indicated possible alternative path of lipid metabolism in studied groups, and in consequence, some elements of vegetarian diet may promote protection against allergy.

Strong-acid, carboxyl-group structures in fulvic acid from the Suwannee River, Georgia. 2. Major structures

USGS Publications Warehouse

Leenheer, J.A.; Wershaw, R. L.; Reddy, M.M.

1995-01-01

Polycarboxylic acid structures that account for the strong-acid characteristics (pKa1 near 2.0) were examined for fulvic acid from the Suwannee River. Studies of model compounds demonstrated that pKa values near 2.0 occur only if the ??-ether or ??-ester groups were in cyclic structures with two to three additional electronegative functional groups (carboxyl, ester, ketone, aromatic groups) at adjacent positions on the ring. Ester linkage removal by alkaline hydrolysis and destruction of ether linkages through cleavage and reduction with hydriodic acid confirmed that the strong carboxyl acidity in fulvic acid was associated with polycarboxylic ??-ether and ??-ester structures. Studies of hypothetical structural models of fulvic acid indicated possible relation of these polycarboxylic structures with the amphiphilic and metal-binding properties of fulvic acid.

Effects of Rice Bran, Flax Seed, and Sunflower Seed on Growth Performance, Carcass Characteristics, Fatty Acid Composition, Free Amino Acid and Peptide Contents, and Sensory Evaluations of Native Korean Cattle (Hanwoo)

PubMed Central

Choi, Chang Bon; Kwon, Hana; Kim, Sung Il; Yang, Un Mok; Lee, Ju Hwan; Park, Eun Kyu

2016-01-01

This study was conducted to evaluate the effect of dietary supplementation with rice bran, flax seed, or sunflower seed to finishing native Korean cattle (Hanwoo) on growth performances, carcass characteristics, fatty acid composition, free amino acid and peptide contents, and sensory evaluations of Longissimus muscle (LM). A total of 39 Hanwoo steers (average age of 22.2 mo and average body weight (BW) of 552.2 kg) were randomly divided into Control, rice bran (RB), flax seed (FS), or Sunflower seed (SS) groups. The steers were group fed for 273 d until they reached an average age of 31.2 mo. Final BW was 768.2, 785.8, 786.2, and 789.0 kg, and average daily gain was 0.79, 0.85, 0.82, and 0.84 kg for the Control, RS, FS, and SS groups, respectively (p>0.05). Fat thickness of the FS group (19.8 mm) was greater (p<0.05) than that of the other groups. Final yield grade converted into numerical values was 2.0 for the RB group, 1.7 for the Control and SS groups, and 1.4 for the FS group. Marbling degrees for the Control, SS, RB, and FS groups were 5.3, 5.1, 4.7, and 4.6, respectively. Percentages of palmitic acid (C16:0), stearic acid (C18:0), and arachidic acid (C20:0) in the LM were not different among the groups. Palmitoleic (C16:1) acid was higher (p<0.05) in the SS group. The concentration of oleic acid was highest (p<0.05) in the Control group (47.73%). The level of linolenic acid (C18:3) was 2.3 times higher (p<0.05) in the FS group compared to the other groups. Methionine concentration was (p<0.05) higher in FS (1.7 mg/100 g) and SS (1.2 mg/100 g) steers than in the Control or RB groups. Glutamic acid and α-aminoadipic acid (α-AAA) contents were (p<0.05) higher in the FS group compared to the other groups. LM from the FS group had numerically higher (p>0.05) scores for flavor, umami, and overall palatability in sensory evaluations. In conclusion, supplementation of flax seed to diets of finishing Hanwoo steers improved sensory evaluations which might have been caused by increases in flavor related amino acids such as methionine, glutamic acid and α-AAA and peptides, anserine and carnosine, and their complex reactions. PMID:26732444

The α-lipoic acid improves high-fat diet-induced cerebral damage through inhibition of oxidative stress and inflammatory reaction.

PubMed

Liu, Yang; Zhang, Qinghua; Wang, Li; Wang, Hui; Sun, Tao; Xia, Hechun; Yang, Yi; Zhang, Li

2017-12-01

This study is to clarify the protective role of α-lipoic acid in high-fat diet-induced cerebral damage mice. The mice were divided into 5 groups: normal control group, high-fat diet (HFD) group, low-dose α-lipoic acid group for prevention, high-dose α-lipoic acid group for prevention, and high-dose α-lipoic acid group for treatment. The groups' weights and blood glucose changes were monitored. We used HE staining to observe morphological changes in the cerebral cortex. The expression levels of the oxidative stress proteins SOD2, catalase, and the inflammatory pathway proteins p-JNK, p-ERK were measured by western blot and immunochemistry. Compared with the control group, the quantity of cortical neurons in the HFD group was decreased, and the samples exhibited retrogression. However, the lipoic acid significantly protected and promoted the cortical neurons survival. Moreover, compared with the HFD group, the expression levels of SOD2 and catalase in the three α-lipoic acid obtained groups were significantly increased. However, the expression levels of the inflammatory pathway proteins p-JNK and p-ERK were significantly decreased. These results indicate that theα-lipoic acid greatly protects the cortical neurons, and inhibited the oxidative stress and inflammatory reactions in the high-fat diet mice. Copyright © 2017 Elsevier B.V. All rights reserved.

Pantothenic acid deficiency may increase the urinary excretion of 2-oxo acids and nicotinamide catabolites in rats.

PubMed

Shibata, Katsumi; Inomoto, Kasumi; Nakata, Chifumi; Fukuwatari, Tsutomu

2013-01-01

Pantothenic acid (PaA) is involved in the metabolism of amino acids as well as fatty acid. We investigated the systemic metabolism of amino acids in PaA-deficient rats. For this purpose, urine samples were collected and 2-oxo acids and L-tryptophan (L-Trp) and its metabolites including nicotinamide were measured. Group 1 was freely fed a conventional chemically-defined complete diet and used as an ad lib-fed control, which group was used for showing reference values. Group 2 was freely fed the complete diet without PaA (PaA-free diet) and used as a PaA-deficient group. Group 3 was fed the complete diet, but the daily food amount was equal to the amount of the PaA-deficient group and used as a pair-fed control group. All rats were orally administered 100 mg of L-Trp/kg body weight at 09:00 on day 34 of the experiment and the following 24-h urine samples were collected. The urinary excretion of the sum of pyruvic acid and oxaloacetic acid was higher in rats fed the PaA-free diets than in the rats fed pair-fed the complete diet. PaA deficiency elicited the increased urinary excretion of anthranilic acid and kynurenic acid, while the urinary excretion of xanthurenic acid decreased. The urinary excretion of L-Trp itself, 3-hydroxyanthranilic acid, and quinolinic acid revealed no differences between the rats fed the PaA-free and pair-fed the complete diets. PaA deficiency elicited the increased excretion of N(1)-methylnicotinamide, N(1)-methyl-2-pyridone-5-carboxamide, and N(1)-methyl-4-pyridone-3-carboxamide. These findings suggest that PaA deficiency disturbs the amino acid catabolism.

Synergistic effects of intravenous and intra-articular tranexamic acid on reducing hemoglobin loss in revision total knee arthroplasty: a prospective, randomized, controlled study.

PubMed

Yuan, Xiangwei; Wang, Jiaxing; Wang, Qiaojie; Zhang, Xianlong

2018-04-01

Tranexamic acid decreases blood loss in primary total knee arthroplasty, and no related prospective randomized clinical trials have been conducted to evaluate the effectiveness and safety of tranexamic acid in revision total knee arthroplasty. Thus, we conducted this work to evaluate the synergistic effects of intravenous plus intra-articular tranexamic acid on reducing hemoglobin loss compared with intra-articular tranexamic acid alone in revision total knee arthroplasty. This prospective, controlled study randomized 96 patients undergoing revision total knee arthroplasty into two groups: an intravenous plus intra-articular tranexamic acid group (48 patients who received 20 mg/kg intravenous tranexamic acid and 3.0 g intra-articular tranexamic acid); and an intra-articular tranexamic acid alone group (48 patients who received the same intravenous volume of normal saline and 3.0 g intra-articular tranexamic acid). The primary outcome was hemoglobin loss. Secondary outcomes included the volume of drain output, the percentage of patients who received transfusions, the number of units transfused, and thromboembolic events. The baseline data, preoperative hemoglobin, and tourniquet time were similar in both groups. There was significantly less hemoglobin loss in the intravenous plus intra-articular tranexamic acid group compared with the intra-articular tranexamic acid alone group (2.7 ± 0.6 g/dL and 3.7 ± 0.7 g/dL; p < 0.001). Compared with the intra-articular tranexamic acid alone group, the intravenous plus intra-articular tranexamic acid group also had significantly less drain output, fewer patients who received transfusions, and fewer units transfused (all p < 0.05). There were no significant differences in thromboembolic events in the two groups during the 3-month follow-up. Compared with intra-articular tranexamic acid alone, combined intravenous plus intra-articular tranexamic acid significantly reduced hemoglobin loss and the need for transfusion without an apparent increase in thromboembolic events in patients who underwent revision total knee arthroplasty. © 2018 AABB.

Effects of acidic polysaccharides from gastrodia rhizome on systolic blood pressure and serum lipid concentrations in spontaneously hypertensive rats fed a high-fat diet.

PubMed

Lee, Ok-Hwan; Kim, Kyung-Im; Han, Chan-Kyu; Kim, Young-Chan; Hong, Hee-Do

2012-01-01

The effects of acidic polysaccharides purified from Gastrodia rhizome on blood pressure and serum lipid levels in spontaneously hypertensive rats (SHR) fed a high-fat diet were investigated. Acidic polysaccharides were purified from crude polysaccharides by DEAE-Sepharose CL-6B. Thirty-six male SHR were randomly divided into three groups: Gastrodia rhizome crude polysaccharide (A), acidic polysaccharide (B) groups, and a control group (C). A 5-week oral administration of all treatment groups was performed daily in 3- to 8-week-old SHRs with a dose of 6 mg/kg of body weight/day. After 5 weeks of treatment, total cholesterol in the acidic polysaccharide group, at 69.7 ± 10.6 mg/dL, was lower than in the crude polysaccharide group (75.0 ± 6.0 mg/dL) and the control group (89.2 ± 7.4 mg/dL). In addition, triglyceride and low-density lipoprotein cholesterol levels in the acidic polysaccharide group were lower than in the crude polysaccharide and control groups. The atherogenic index of the acidic polysaccharide group was 46.3% lower than in the control group. Initial blood pressure after the initial three weeks on the high-fat diet averaged 195.9 ± 3.3 mmHg among all rats. Compared with the initial blood pressure, the final blood pressure in the control group was increased by 22.8 mmHg, whereas it decreased in the acidic polysaccharide group by 14.9 mmHg. These results indicate that acidic polysaccharides from Gastrodia rhizome reduce hypertension and improve serum lipid levels.

A randomized control trial to evaluate the effectiveness of intravenous, intra-articular and topical wash regimes of tranexamic acid in primary total knee arthroplasty.

PubMed

Prakash, Jatin; Seon, Jong-Keun; Park, Yong Jin; Jin, Cheng; Song, Eun-Kyoo

2017-01-01

The efficacy of tranexamic acid to decrease post-operative blood loss and blood transfusion is well established in literature. However, the ideal mode of administration is debatable. Limited literature has compared all the available modes of administration including intravenous (IV), topical irrigation and retrograde through drain. We hypothesized that no difference would be present in either form of administration of tranexamic acid. Fifty patients in four groups were enrolled for study. Group 1 received drug intravenously, group 2 had topical washing with drug before closure, group 3 received drug after closure through drain and group 4 was control that received no tranexamic acid. Post-operative blood loss, calculated blood loss, haemoglobin drop, transfusion requirements and complications were studied for all four groups. Tranexamic acid results in lower bleeding irrespective of the mode of administration compared to control group. Total loss at end of 5 days is similar in all tranexamic acid groups irrespective of method used to deliver the drug. Calculated blood loss and haemoglobin drop was minimum for IV and in patients who were administered drug retrograde through drain. Requirement for blood transfusion was found to be lower in all tranexamic acid patients compared to non-tranexamic acid group. The requirement was highest in topical wash group among all tranexamic acid groups. We conclude that intra-articular administration through drain and IV administration are equally effective and superior to topical wash method in reducing blood loss, haemoglobin fall and transfusion requirements.

Topical use of tranexamic acid in open heart surgery.

PubMed

Chaudhary, Farid Ahmad; Pervaz, Zahid; Ilyas, Sana; Niaz, Muhammad Nabeel

2018-04-01

To determine the efficacy of topical pouring of tranexamic acid in reducing post-operative mediastinal bleeding, requirement for blood products and the rate of re-exploration for re-securing haemostasis or relief of pericardial tamponade after open heart surgery. The prospective, randomised, placebo-controlled, double-blind comparative study was conducted from March 2013 to September 2015 at Rehmatul-lil-Alameen Institute of Cardiology, Punjab Employees Social Security Institution, Lahore, and comprised patients scheduled for primary isolated elective or urgent open heart surgery. The subjects were divided into two equal groups. The hetranexamic acid group received cardiac bath with 2gm of tranexamic acid diluted in 50mlof normal saline, while the placebo group received cardiac bath without tranexamic acid. Before the closure of sternum, the solution was poured into pericardial cavity as cardiac bath while the chest tubes were temporarily clamped. Data was entered into a pre-designed proforma. Of the 100 subjects, there were 50(50%) in each of the two groups. There was no difference in surgical characteristics and perioperative complications in the groups (p>0.05). After 48 post-operative hours, total blood loss was significantly less in the tranexamic acid group compared to the placebo group (p<0.05). Significantly less number of blood pints were transfused in the acid group than the placebo group (p<0.05). No patient in the acid group was re-explored for excessive bleeding compared to 4(8%) in the placebo group. There was significant reduction in post-operative blood drainage, need of blood products and rate of re-exploration after topical use of tranexamic acid in open heart surgery.

Comparison of acetic acid and ethanol sclerotherapy for simple renal cysts: clinical experience with 86 patients.

PubMed

Cho, Young Jun; Shin, Ji Hoon

2016-01-01

To compare the efficacy and treatment session numbers of acetic acid to that of ethanol sclerotherapy for the treatment of simple renal cysts. Between February 2004 and June 2013, 86 patients with simple renal cysts underwent percutaneous aspiration and injection of 50 %-acetic-acid (42 cysts) and 95 %-ethanol (44 cysts). The patient demographics, volume reduction rate, number of treatment sessions, and complications were then analyzed. The volume reduction rate was 94.1 ± 7.6 % in the 50 %-acetic acid group and 94.7 ± 11.7 % in the 95 %-ethanol group, and without a statistical difference. The rates of complete remission, partial remission, and no response were 57.1, 42.9 and 0 %, respectively, for the acetic acid group, and 70.5, 25.0, and 4.5 %, respectively, for the ethanol group. No statistical difference was observed between the two groups. Compared to the acetic acid group, the ethanol group had a higher number of treatment sessions, i.e. 1.10 ± 0.30 in the acetic acid group and 1.80 ± 0.79 in the ethanol group. Mild flank pain was a minor complication that occurred in both groups. Acetic acid seems to have equivalent sclerosing effects on simple renal cysts compared with those of ethanol despites of fewer treatment sessions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Radchenko, Valery; Meyer, Catherine Anne Louise; Engle, Jonathan Ward

Scandium-44 g (half-life 3.97 h) shows promise for positron emission tomography (PET) imaging of longer biological processes than that of the current gold standard, 18F, due to its favorable decay parameters. One source of 44gSc is the long-lived parent nuclide 44Ti (half-life 60.0 a). A 44Ti/ 44gSc generator would have the ability to provide radionuclidically pure 44gSc on a daily basis. The production of 44Ti via the 45Sc(p,2n) reaction requires high proton beam currents and long irradiation times. Recovery and purification of no-carrier added (nca) 44Ti from scandium metal targets involves complex separation chemistry. In this study, separation systems basedmore » on solid phase extraction chromatography were investigated, including branched diglycolamide (BDGA) resin and hydroxamate based ZR resin. Lastly, results indicate that ZR resin in HCl media represents an effective 44Ti/ 44gSc separation system.« less

Pathogenetic aspects of uncomplicated urinary tract infection: recent advances.

PubMed

Fünfstück, R; Smith, J W; Tschäpe, H; Stein, G

1997-01-01

Urinary tract infections mostly are caused by Enterobacteriaceae; E. coli dominating in 80-90% for uncomplicated diseases. Microorganisms possessing the ability to colonize the uroepithelium (fimbriae/pili) and to cytotoxically damage cells and tissue (hemolysin) may initiate acute infection. Properties such as serum resistance, iron sequesteration, hydroxamate production and the presence of K-antigen are found in strains which persist in the host without initiating clinical symptoms. The ability of bacteria to adhere to cells of the epithelial boundary layer of the host organisms is of initial importance in the origin and progress of an infection. A variety of specific factors, e.g. glycolipids on the surface of the uroepithelium as well as cellular and humoral disorders of immunoreactions in the host determine the course of a disease. The immune response may ameliorate clinical symptoms and select urovirulent characteristics of the causative microorganism in recurrent diseases.

The Protective Effects of Alpha-Lipoic Acid and Coenzyme Q10 Combination on Ovarian Ischemia-Reperfusion Injury: An Experimental Study.

PubMed

Tuncer, Ahmet Ali; Bozkurt, Mehmet Fatih; Koken, Tulay; Dogan, Nurhan; Pektaş, Mine Kanat; Baskin Embleton, Didem

2016-01-01

Objective. This study aims to evaluate whether alpha-lipoic acid and/or coenzyme Q10 can protect the prepubertal ovarian tissue from ischemia-reperfusion injury in an experimental rat model of ovarian torsion. Materials and Methods. Forty-two female preadolescent Wistar-Albino rats were divided into 6 equal groups randomly. The sham group had laparotomy without torsion; the other groups had torsion/detorsion procedure. After undergoing torsion, group 2 received saline, group 3 received olive oil, group 4 received alpha-lipoic acid, group 5 received coenzyme Q10, and group 6 received both alpha-lipoic acid and coenzyme Q10 orally. The oxidant-antioxidant statuses of these groups were compared using biochemical measurement of oxidized/reduced glutathione, glutathione peroxidase and malondialdehyde, pathological evaluation of damage and apoptosis within the ovarian tissue, and immunohistochemical assessment of nitric oxide synthase. Results. The left ovaries of the alpha-lipoic acid + coenzyme Q10 group had significantly lower apoptosis scores and significantly higher nitric oxide synthase content than the left ovaries of the control groups. The alpha-lipoic acid + coenzyme Q10 group had significantly higher glutathione peroxidase levels and serum malondialdehyde concentrations than the sham group. Conclusions. The combination of alpha-lipoic acid and coenzyme Q10 has beneficial effects on oxidative stress induced by ischemia-reperfusion injury related to ovarian torsion.

Potency of pre-post treatment of coenzyme Q10 and melatonin supplement in ameliorating the impaired fatty acid profile in rodent model of autism.

PubMed

El-Ansary, Afaf; Al-Ghamdi, Mashael; Bhat, Ramesa Shafi; Al-Daihan, Sooad; Al-Ayadhi, Laila

2016-01-01

Abnormalities in fatty acid metabolism and membrane fatty acid composition play a part in a wide range of neurodevelopmental and psychiatric disorders. Altered fatty acid homeostasis as a result of insufficient dietary supplementation, genetic defects, the function of enzymes involved in their metabolism, or mitochondrial dysfunction contributes to the development of autism. This study evaluates the association of altered brain lipid composition and neurotoxicity related to autism spectrum disorders in propionic acid (PA)-treated rats. Forty-eight young male western albino rats were used in this study. They were grouped into six equal groups with eight rats in each. The first group received only phosphate buffered saline (control group). The second group received a neurotoxic dose of buffered PA (250 mg/kg body weight/day for 3 consecutive days). The third and fourth groups were intoxicated with PA as described above followed by treatment with either coenzyme Q (4.5 mg/kg body weight) or melatonin (10 mg/kg body weight) for 1 week (therapeutically treated groups). The fifth and sixth groups were administered both compounds for 1 week prior to PA (protected groups). Methyl esters of fatty acid were extracted with hexane, and the fatty acid composition of the extract was analyzed on a gas chromatography. The obtained data proved that fatty acids are altered in brain tissue of PA-treated rats. All saturated fatty acids were increased while all unsaturated fatty acids were significantly decreased in the PA-treated group and relatively ameliorated in the pre-post melatonin and coenzyme Q groups. Melatonin and coenzyme Q were effective in restoring normal level of most of the impaired fatty acids in PA-intoxicated rats which could help suggest both as supplements to ameliorate the autistic features induced in rat pups.

Tissue Fatty Acid Profile is Differently Modulated from Olive Oil and Omega-3 Polyunsaturated Fatty Acids in ApcMin/+ Mice.

PubMed

Tutino, Valeria; Caruso, Maria G; De Leonardis, Giampiero; De Nunzio, Valentina; Notarnicola, Maria

2017-11-16

Fatty acid profile can be considered an appropriate biomarker for investigating the relations between the patterns of fatty acid metabolism and specific diseases, as cancer, cardiovascular and degenerative diseases. Aim of this study was to test the effects of diets enriched with olive oil and omega-3 Polyunsaturated Fatty Acids (PUFAs) on fatty acid profile in intestinal tissue of ApcMin/+ mice. Three groups of animals were considered: control group, receiving a standard diet; olive oilgroup, receiving a standard diet enriched with olive oil; omega-3 group, receiving a standard diet enriched with salmon fish. Tissue fatty acid profile was evaluated by gas chromatography method. Olive oil and omega-3 PUFAs in the diet differently affect the tissue fatty acid profile. Compared to control group, the levels of Saturated Fatty Acids (SFAs) were lower in olive oil group, while an increase of SFAs was found in omega-3 group. Monounsaturated Fatty Acids (MUFAs) levels were enhanced after olive oil treatment, and in particular, a significant increase of oleic acid levels was detected; MUFAs levels were instead reduced in omega-3 group in line with the decrease of oleic acid levels. The total PUFAs levels were lower in olive oil respect to control group. Moreover, a significant induction of Saturation Index (SI) levels was observed after omega-3 PUFAs treatment, while its levels were reduced in mice fed with olive oil. Our data demonstrated a different effect of olive oil and omega-3 PUFAs on tissue lipid profile in APCMin/+ mice. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Evaluation of the Efficacy of Tranexamic Acid on the Surgical Field in Primary Cleft Palate Surgery on Children-A Prospective, Randomized Clinical Study.

PubMed

Durga, Padmaja; Raavula, Parvathi; Gurajala, Indira; Gunnam, Poojita; Veerabathula, Prardhana; Reddy, Mukund; Upputuri, Omkar; Ramachandran, Gopinath

2015-09-01

To assess the effect of tranexamic acid on the quality of the surgical field. Prospective, randomized, double-blind study. Institutional, tertiary referral hospital. American Society of Anesthesiologists physical status class I patients, aged 8 to 60 months with Group II or III (Balakrishnan's classification) clefts scheduled for cleft palate repair. Children were randomized into two groups. The control group received saline, and the tranexamic acid group received tranexamic acid 10 mg/kg as a bolus, 15 minutes before incision. Grade of surgical field on a 10-point scale, surgeon satisfaction, and primary hemorrhage. Significant improvements were noted in surgeon satisfaction and median grade of assessment of the surgical field (4 [interquartile range, 4 to 6] in the control group vs. 3 [interquartile range, 2 to 4] in the test group; P = .003) in the tranexamic acid group compared to the control group. Preincision administration of 10 mg/kg of tranexamic acid significantly improved the surgical field during cleft palate repair.

Influence of Citric Acid on the Pink Color and Characteristics of Sous Vide Processed Chicken Breasts During Chill Storage

PubMed Central

Lim, Ki-Won

2015-01-01

Chicken breast dipped with citric acid (CA) was treated by sous vide processing and stored in a refrigerated state for 0, 3, 6, 9, and 14 d. A non-dipped control group (CON) and three groups dipped in different concentrations of citric acid concentration were analyzed (0.5%, 0.5CIT; 2.0%, 2CIT and 5.0%, 5CIT; w/v). Cooking yield and moisture content increased due to the citric acid. While the redness of the juice and meat in all groups showed significant increase during storage, the redness of the citric acid groups was reduced compared to the control group (p<0.05). The percentage of myoglobin denaturation (PMD) of the CA groups was also increased according to the level of CA during storage. Total aerobic counts, Enterobacteriaceae counts, volatile basic nitrogen and thiobarbituric acid reactive substances (TBARS) were generally lower in the citric acid-treated samples than in untreated ones, indicating extended shelf life of the cooked chicken breast dipped in citric acid solution. The shear force of the 2CIT and 5CIT groups was significantly lower (p<0.05). The findings indicated positive effects in the physicochemical properties and storage ability of sous vide chicken breast at 2% and 5% citric acid concentrations. PMID:26761885

Effects of tranexamic acid on coagulation indexes of patients undergoing heart valve replacement surgery under cardiopulmonary bypass

PubMed Central

Liu, Fei; Xu, Dong; Zhang, Kefeng; Zhang, Jian

2016-01-01

This study aims to explore the effects of tranexamic acid on the coagulation indexes of patients undergoing heart valve replacement surgery under the condition of cardiopulmonary bypass (CPB). One hundred patients who conformed to the inclusive criteria were selected and divided into a tranexamic acid group and a non-tranexamic acid group. They all underwent heart valve replacement surgery under CPB. Patients in the tranexamic acid group were intravenously injected with 1 g of tranexamic acid (100 mL) at the time point after anesthesia induction and before skin incision and at the time point after the neutralization of heparin. Patients in the non-tranexamic acid group were given 100 mL of normal saline at corresponding time points, respectively. Then the coagulation indexes of the two groups were analyzed. The activated blood clotting time (ACT) of the two groups was within normal scope before CPB, while four coagulation indexes including prothrombin time (PT), activated partial thromboplastin time (APTT), international normalized ratio (INR), and fibrinogen (FIB) had significant increases after surgery; the PT and INR of the tranexamic acid group had a remarkable decline after surgery. All the findings suggest that the application of tranexamic acid in heart valve replacement surgery under CPB can effectively reduce intraoperative and postoperative blood loss. PMID:27694613

Renoprotective Effect of Humic Acid on Renal Ischemia-Reperfusion Injury: An Experimental Study in Rats.

PubMed

Akbas, Alpaslan; Silan, Coskun; Gulpinar, Murat Tolga; Sancak, Eyup Burak; Ozkanli, Sidika Seyma; Cakir, Dilek Ulker

2015-12-01

Humic acid is an antioxidant molecule used in agriculture and livestock breeding, as well as in medicine. Our aim was to investigate the potential renoprotective effects of humic acid in a renal ischemia reperfusion model. Twenty-one rats were randomly divided into three equal groups. Intraperitoneal serum or humic acid was injected at 1, 12, and 24 h. Non-ischemic group I was evaluated as sham. The left renal artery was clamped in serum (group II) and intraperitoneal humic acid (group III) to subject to left renal ischemic reperfusion procedure. Ischemia and reperfusion time was 60 min for each. Total antioxidant status, total oxidative status, oxidative stress index, and ischemia-modified albumin levels were analyzed biochemically from the serum samples. Kidneys were evaluated histopatologically and immunohistochemically. Biochemical results showed that total oxidative status, ischemia-modified albumin, and oxidative stress index levels were significantly decreased, but total antioxidant status was increased in the humic acid group (III) compared with the ischemia group (II) On histopathological examination, renal tubular dilatation, tubular cell damage and necrosis, dilatation of Bowman's capsule, hyaline casts, and tubular cell spillage were decreased in the humic acid group (III) compared with the ischemia group (II). Immunohistochemical results showed that apoptosis was deteriorated in group III. Renal ischemia reperfusion injury was attenuated by humic acid administration. These observations indicate that humic acid may have a potential therapeutic effect on renal ischemia reperfusion injury by preventing oxidative stress.

A novel amino acid analysis method using derivatization of multiple functional groups followed by liquid chromatography/tandem mass spectrometry.

PubMed

Sakaguchi, Yohei; Kinumi, Tomoya; Yamazaki, Taichi; Takatsu, Akiko

2015-03-21

We have developed a novel amino acid analysis method using derivatization of multiple functional groups (amino, carboxyl, and phenolic hydroxyl groups). The amino, carboxyl, and phenolic hydroxyl groups of the amino acids were derivatized with 1-bromobutane so that the hydrophobicities and basicities of the amino acids were improved. The derivatized amino acids, including amino group-modified amino acids, could be detected with high sensitivity using liquid chromatography/tandem mass spectrometry (LC-MS/MS). In this study, 17 amino acids obtained by hydrolyzing proteins and 4 amino group-modified amino acids found in the human body (N,N-dimethylglycine, N-formyl-L-methionine, L-pyroglutamic acid, and sarcosine) were selected as target compounds. The 21 derivatized amino acids could be separated using an octadecyl-silylated silica column within 20 min and simultaneously detected. The detection limits for the 21 amino acids were 5.4-91 fmol, and the calibration curves were linear over the range of 10-100 nmol L(-1) (r(2) > 0.9984) with good repeatability. A confirmatory experiment showed that our proposed method could be applied to the determination of a protein certified reference material using the analysis of 12 amino acids combined with isotope dilution mass spectrometry. Furthermore, the proposed method was successfully applied to a stable isotope-coded derivatization method using 1-bromobutane and 1-bromobutane-4,4,4-d3 for comparative analysis of amino acids in human serum.

Dietary (n-6 : n-3) Fatty Acids Alter Plasma and Tissue Fatty Acid Composition in Pregnant Sprague Dawley Rats

PubMed Central

Kassem, Amira Abdulbari; Abu Bakar, Md Zuki; Yong Meng, Goh; Mustapha, Noordin Mohamed

2012-01-01

The objective of this paper is to study the effects of varying dietary levels of n-6 : n-3 fatty acid ratio on plasma and tissue fatty acid composition in rat. The treatment groups included control rats fed chow diet only, rats fed 50% soybean oil (SBO): 50% cod liver oil (CLO) (1 : 1), 84% SBO: 16% CLO (6 : 1), 96% SBO: 4% CLO (30 : 1). Blood samples were taken at day 15 of pregnancy, and the plasma and tissue were analyzed for fatty acid profile. The n-3 PUFA in plasma of Diet 1 : 1 group was significantly higher than the other diet groups, while the total n-6 PUFA in plasma was significantly higher in Diet 30 : 1 group as compared to the control and Diet 1 : 1 groups. The Diet 1 : 1 group showed significantly greater percentages of total n-3 PUFA and docosahexaenoic acid in adipose and liver tissue, and this clearly reflected the contribution of n-3 fatty acids from CLO. The total n-6 PUFA, linoleic acid, and arachidonic acid were significantly difference in Diet 30 : 1 as compared to Diet 1 : 1 and control group. These results demonstrated that the dietary ratio of n-6 : n-3 fatty acid ratio significantly affected plasma and tissue fatty acids profile in pregnant rat. PMID:22489205

The effect of amino acid infusion on anesthesia-induced hypothermia in muscle atrophy model rats.

PubMed

Kanazawa, Masahiro; Ando, Satoko; Tsuda, Michio; Suzuki, Toshiyasu

2010-01-01

An infusion of amino acids stimulates heat production in skeletal muscle and then attenuates the anesthesia-induced hypothermia. However, in a clinical setting, some patients have atrophic skeletal muscle caused by various factors. The present study was therefore conducted to investigate the effect of amino acids on the anesthesia-induced hypothermia in the state of muscle atrophy. As the muscle atrophy model, Sprague-Dawley rats were subjected to hindlimb immobilization for 2 wk. Normal rats and atrophy model rats were randomly assigned to one of the two treatment groups: saline or amino acids (n=8 for each group). Test solutions were administered intravenously to the rats under sevoflurane anesthesia for 180 min, and the rectal temperature was measured. Plasma samples were collected for measurement of insulin, blood glucose, and free amino acids. The rectal temperature was significantly higher in the normal-amino acid group than in the muscle atrophy-amino acid group from 75 to 180 min. The plasma insulin level was significantly higher in the rats given amino acids than in the rats given saline in both normal and model groups. In the rats given amino acids, plasma total free amino acid concentration was higher in the model group than in the normal group. These results indicate that skeletal muscle plays an important role in changes in body temperature during anesthesia and the effect of amino acids on anesthesia-induced hypothermia decreases in the muscle atrophy state. In addition, intravenous amino acids administration during anesthesia induces an increase in the plasma insulin level.

Neuroprotective effect of humic Acid on focal cerebral ischemia injury: an experimental study in rats.

PubMed

Ozkan, Adile; Sen, Halil Murat; Sehitoglu, Ibrahim; Alacam, Hasan; Guven, Mustafa; Aras, Adem Bozkurt; Akman, Tarik; Silan, Coşkun; Cosar, Murat; Karaman, Handan Isin Ozisik

2015-02-01

Stroke is still a major cause of death and permanent neurological disability. As humic acids are well-known antioxidant molecules, the purpose of this study was to investigate the potential neuroprotective effects of humic acid in a focal cerebral ischemia model. Twenty-four rats were divided equally into three groups. A middle cerebral artery occlusion model was performed in this study where control (group II) and humic acid (group III) were administered intraperitoneally following an ischemic experimental procedure. Group I was evaluated as sham. Malondialdehyde (MDA), superoxide dismutase (SOD), and nuclear respiratory factor-1 (NRF-1) levels were analyzed biochemically on the right side of the ischemic cerebral hemisphere, while ischemic histopathological studies were completed on the left side to investigate the antioxidant status. Biochemical results showed that SOD and NRF-1 levels were significantly increased in the humic acid group (III) compared with the control group (II) while MDA levels were significantly decreased. On histopathological examination, cerebral edema, vacuolization, degeneration, and destruction of neural elements were decreased in the humic acid group (III) compared with the control group (II). Cerebral ischemia was attenuated by humic acid administration. These observations indicate that humic acid may have potential as a therapeutic agent in cerebral ischemia by preventing oxidative stress.

Mixed micelles of 7,12-dioxolithocholic acid and selected hydrophobic bile acids: interaction parameter, partition coefficient of nitrazepam and mixed micelles haemolytic potential.

PubMed

Poša, Mihalj; Tepavčević, Vesna

2011-09-01

The formation of mixed micelles built of 7,12-dioxolithocholic and the following hydrophobic bile acids was examined by conductometric method: cholic (C), deoxycholic (D), chenodeoxycholic (CD), 12-oxolithocholic (12-oxoL), 7-oxolithocholic (7-oxoL), ursodeoxycholic (UD) and hiodeoxycholic (HD). Interaction parameter (β) in the studied binary mixed micelles had negative value, suggesting synergism between micelle building units. Based on β value, the hydrophobic bile acids formed two groups: group I (C, D and CD) and group II (12-oxoL, 7-oxoL, UD and HD). Bile acids from group II had more negative β values than bile acids from group I. Also, bile acids from group II formed intermolecular hydrogen bonds in aggregates with both smaller (2) and higher (4) aggregation numbers, according to the analysis of their stereochemical (conformational) structures and possible structures of mixed micelles built of these bile acids and 7,12-dioxolithocholic acid. Haemolytic potential and partition coefficient of nitrazepam were higher in mixed micelles built of the more hydrophobic bile acids (C, D, CD) and 7,12-dioxolithocholic acid than in micelles built only of 7,12-dioxolithocholic acid. On the other hand, these mixed micelles still had lower values of haemolytic potential than micelles built of C, D or CD. The mixed micelles that included bile acids: 12-oxoL, 7-oxoL, UD or HD did not significantly differ from the micelles of 7,12-dioxolithocholic acid, observing the values of their haemolytic potential. Copyright © 2011 Elsevier B.V. All rights reserved.

Amino acid ionic liquids.

PubMed

Ohno, Hiroyuki; Fukumoto, Kenta

2007-11-01

The preparation of ionic liquids derived from amino acids, and their properties, are outlined. Since amino acids have both a carboxylic acid residue and an amino group in a single molecule, they can be used as either anions or cations. These groups are also useful in their ability to introduce functional group(s). Twenty different natural amino acids were used as anions, to couple with the 1-ethyl-3-methylimidazolium cation. The salts obtained were all liquid at room temperature. The properties of the resulting ionic liquids (AAILs) depend on the side groups of the amino acids involved. These AAILs, composed of an amino acid with some functional groups such as a hydrogen bonding group, a charged group, or an aromatic ring, had an increased glass transition (or melting) temperature and/or higher viscosity as a result of additional interactions among the ions. Viscosity is reduced and the decomposition temperature of imidazolium-type salts is improved by using the tetrabutylphosphonium cation. The chirality of AAILs was maintained even upon heating to 150 degrees C after acetylation of the free amino group. The amino group was also modified to introduce a strong acid group so as to form hydrophobic and chiral ionic liquids. Unique phase behavior of the resulting hydrophobic ionic liquids and water mixture is found; the mixture is clearly phase separated at room temperature, but the solubility of water in this IL increases upon cooling, to give a homogeneous solution. This phase change is reversible, and separation occurs again by raising the temperature a few degrees. It is extraordinary for an IL/water mixture to display such behavior with a lower critical solution temperature. Some likely applications are proposed for these amino acid derived ionic liquids.

The effect of systemic lipoic acid on hearing preservation after cochlear implantation via the round window approach: A guinea pig model.

PubMed

Chang, Mun Young; Gwon, Tae Mok; Lee, Ho Sun; Lee, Jun Ho; Oh, Seung Ha; Kim, Sung June; Park, Min-Hyun

2017-03-15

The present study aimed to evaluate the effects of systemic lipoic acid on hearing preservation after cochlear implantation. Twelve Dunkin-Hartley guinea pigs were randomly divided into two groups: the control group and the lipoic acid group. Animals in the lipoic acid group received lipoic acid intraperitoneally for 4 weeks. A sterilised silicone electrode-dummy was inserted through the round window to a depth of approximately 5 mm. The hearing level was measured using auditory brainstem responses (ABRs) prior to electrode-dummy insertion, and at 4 days and 1, 2, 3 and 4 weeks after electrode-dummy insertion. The threshold shift was defined as the difference between the pre-operative threshold and each of the post-operative thresholds. The cochleae were examined histologically 4 weeks after electrode-dummy insertion. Threshold shifts changed with frequency but not time. At 2kHz, ABR threshold shifts were statistically significantly lower in the lipoic acid group than the control group. At 8, 16 and 32kHz, there was no significant difference in the ABR threshold shift between the two groups. Histologic review revealed less intracochlear fibrosis along the electrode-dummy insertion site in the lipoic acid group than in the control group. The spiral ganglion cell densities of the basal, middle and apical turns were significantly higher in the lipoic acid group compared with the control group. Therefore, systemic lipoic acid administration appears to effectively preserve hearing at low frequencies in patients undergoing cochlear implantation. These effects may be attributed to the protection of spiral ganglion cells and prevention of intracochlear fibrosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of intraoperative amino acids with or without glucose infusion on body temperature, insulin, and blood glucose levels in patients undergoing laparoscopic colectomy: a preliminary report.

PubMed

Fujita, Yasuki; Tokunaga, Chiharu; Yamaguchi, Sayo; Nakamura, Kayo; Horiguchi, Yuu; Kaneko, Michiko; Iwakura, Takeo

2014-09-01

Amino acid administration helps to prevent intraoperative hypothermia but may enhance thermogenesis when combined with glucose infusion. The aim of this study was to examine the effect of intraoperative amino acid administration, with or without glucose infusion, on temperature regulation during laparoscopic colectomy. Twenty-one patients whose physical status was classified I or II by the American Society of Anesthesiologists, and who were undergoing elective laparoscopic colectomy were enrolled. The exclusion criteria were a history of diabetes and/or obesity, preoperative high levels of C-reactive protein, high blood glucose and/or body temperature after anesthesia induction, and surgical time >500 minutes. Each patient received an acetate ringer solution and was randomly assigned to one of three groups. Group A patients were given only amino acids. Group AG patients were given amino acids and glucose. Group C patients were given neither amino acids nor glucose. Tympanic membrane temperatures and blood glucose and insulin levels were measured intraoperatively. Intraoperative amino acid infusion significantly increased body temperature during surgery as compared with either Group AG or C. The blood glucose levels in Group AG were significantly higher than those in Groups A and C. However, there were no significant differences between Groups A and C. Two hours after anesthesia induction, serum insulin levels in Groups A and AG significantly increased compared with Group C. No significant differences in the postoperative complications or patient hospitalization lengths were detected between the groups. Intraoperative amino acid infusion without glucose administration maintains body temperature more effectively than combined amino acid and glucose infusion in patients undergoing laparoscopic colectomy, despite unaltered intraoperative insulin levels. Copyright © 2014. Published by Elsevier B.V.

Changes of lipid and fatty acid absorption induced by high dose of citric acid ester and lecithin emulsifiers.

PubMed

Sadouki, Mohamed; Bouchoucha, Michel

2014-09-01

To describe the effect of two food emulsifiers, lecithin (E322) and citric acid esters of mono-and diglycerides of fatty acids (E472c), on the intestinal absorption of lipids. The experiment was conducted on 24 male Wistar rats randomly assigned in three groups. For two groups of six rats, 30% of the lipid intake was replaced with lecithin (L) or citric acid ester of mono and diglycerides, (E); the remaining 12 rats were the control group (C). Diet and fecal fat analysis was used to determine the apparent lipid absorption (ALA) and fatty acids. ALA was significantly lower in the group E than in the groups C and L (p < 0.001). ALA of long saturated chain fatty acids decreased while the length of the carbon chains increased, and this decrease was higher in the group E. E472c emulsifier decreased the intestinal absorption of lipids.

Genetic analysis of groups of mid-infrared predicted fatty acids in milk.

PubMed

Narayana, S G; Schenkel, F S; Fleming, A; Koeck, A; Malchiodi, F; Jamrozik, J; Johnston, J; Sargolzaei, M; Miglior, F

2017-06-01

The objective of this study was to investigate genetic variability of mid-infrared predicted fatty acid groups in Canadian Holstein cattle. Genetic parameters were estimated for 5 groups of fatty acids: short-chain (4 to 10 carbons), medium-chain (11 to 16 carbons), long-chain (17 to 22 carbons), saturated, and unsaturated fatty acids. The data set included 49,127 test-day records from 10,029 first-lactation Holstein cows in 810 herds. The random regression animal test-day model included days in milk, herd-test date, and age-season of calving (polynomial regression) as fixed effects, herd-year of calving, animal additive genetic effect, and permanent environment effects as random polynomial regressions, and random residual effect. Legendre polynomials of the third degree were selected for the fixed regression for age-season of calving effect and Legendre polynomials of the fourth degree were selected for the random regression for animal additive genetic, permanent environment, and herd-year effect. The average daily heritability over the lactation for the medium-chain fatty acid group (0.32) was higher than for the short-chain (0.24) and long-chain (0.23) fatty acid groups. The average daily heritability for the saturated fatty acid group (0.33) was greater than for the unsaturated fatty acid group (0.21). Estimated average daily genetic correlations were positive among all fatty acid groups and ranged from moderate to high (0.63-0.96). The genetic correlations illustrated similarities and differences in their origin and the makeup of the groupings based on chain length and saturation. These results provide evidence for the existence of genetic variation in mid-infrared predicted fatty acid groups, and the possibility of improving milk fatty acid profile through genetic selection in Canadian dairy cattle. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Caffeic acid treatment alters the extracellular adenine nucleotide hydrolysis in platelets and lymphocytes of adult rats.

PubMed

Anwar, Javed; Spanevello, Roselia Maria; Pimentel, Victor Camera; Gutierres, Jessié; Thomé, Gustavo; Cardoso, Andreia; Zanini, Daniela; Martins, Caroline; Palma, Heloisa Einloft; Bagatini, Margarete Dulce; Baldissarelli, Jucimara; Schmatz, Roberta; Leal, Cláudio Alberto Martins; da Costa, Pauline; Morsch, Vera Maria; Schetinger, Maria Rosa Chitolina

2013-06-01

This study evaluated the effects of caffeic acid on ectonucleotidase activities such as NTPDase (nucleoside triphosphate diphosphohydrolase), Ecto-NPP (nucleotide pyrophosphatase/phosphodiesterase), 5'-nucleotidase and adenosine deaminase (ADA) in platelets and lymphocytes of rats, as well as in the profile of platelet aggregation. Animals were divided into five groups: I (control); II (oil); III (caffeic acid 10 mg/kg); IV (caffeic acid 50 mg/kg); and V (caffeic acid 100 mg/kg). Animals were treated with caffeic acid diluted in oil for 30 days. In platelets, caffeic acid decreased the ATP hydrolysis and increased ADP hydrolysis in groups III, IV and V when compared to control (P<0.05). The 5'-nucleotidase activity was decreased, while E-NPP and ADA activities were increased in platelets of rats of groups III, IV and V (P<0.05). Caffeic acid reduced significantly the platelet aggregation in the animals of groups III, IV and V in relation to group I (P<0.05). In lymphocytes, the NTPDase and ADA activities were increased in all groups treated with caffeic acid when compared to control (P<0.05). These findings demonstrated that the enzymes were altered in tissues by caffeic acid and this compound decreased the platelet aggregation suggesting that caffeic acid should be considered a potentially therapeutic agent in disorders related to the purinergic system. Copyright © 2013 Elsevier Ltd. All rights reserved.

H9N2-specific IgG and CD4+CD25+ T cells in broilers fed a diet supplemented with organic acids.

PubMed

Lee, In Kyu; Bae, Suhan; Gu, Min Jeong; You, Sun Jong; Kim, Girak; Park, Sung-Moo; Jeung, Woon-Hee; Ko, Kwang Hyun; Cho, Kyung Jin; Kang, Jung Sun; Yun, Cheol-Heui

2017-05-01

Organic acids have long been known for their beneficial effects on growth performance in domestic animals. However, their impact on immune responses against viral antigens in chickens is unclear. The present study aimed to investigate immunological parameters in broilers immunized with a H9N2 vaccine and/or fed a diet containing organic acids (citric, formic, and lactic acids). We allotted 1-day-old broilers into 4 groups: control (C), fed a diet supplemented with organic acids (O), administered a H9N2 vaccine (V), and fed a diet supplemented with organic acids and administered a H9N2 vaccine (OV). Blood and spleen samples were taken at 2, 7 and 14 d post vaccination (DPV). At 14 DPV, total and H9N2-specific IgG levels were significantly lower in the OV group than in the V group. However, it was intriguing to observe that at 2 DPV, the percentage of CD4+CD25+ T cells was significantly higher in the OV group than in the other groups, indicating the potential induction of regulatory T cells by organic acids. In contrast, at 2 DPV, the percentage of CD4+CD28+ T cells were significantly lower in the OV group than in the other groups, suggesting that CD28 molecules are down-regulated by the treatment. The expression of CD28 on CD4+ T cells, up-regulated by the stimulation with phorbol 12-myristate 13-acetate (PMA) and ionomycin (Iono), was inhibited upon organic acid treatment in OV group. In addition, the proliferation of lymphocytes, stimulated with formalin-inactivated H9N2, was significantly higher in the V group than in the OV group. Alpha 1-acid glycoprotein (AGP) production was significantly lower in the OV group than in the V group, suggesting that the organic acids inhibited the inflammation caused by the vaccination. Overall, induction of regulatory CD4+CD25+ T cells, coinciding with the decrease of H9N2-specific antibodies, was observed in broilers fed organic acids. © 2016 Poultry Science Association Inc.

Amino acid supplementation alters bone metabolism during simulated weightlessness

NASA Technical Reports Server (NTRS)

Zwart, S. R.; Davis-Street, J. E.; Paddon-Jones, D.; Ferrando, A. A.; Wolfe, R. R.; Smith, S. M.

2005-01-01

High-protein and acidogenic diets induce hypercalciuria. Foods or supplements with excess sulfur-containing amino acids increase endogenous sulfuric acid production and therefore have the potential to increase calcium excretion and alter bone metabolism. In this study, effects of an amino acid/carbohydrate supplement on bone resorption were examined during bed rest. Thirteen subjects were divided at random into two groups: a control group (Con, n = 6) and an amino acid-supplemented group (AA, n = 7) who consumed an extra 49.5 g essential amino acids and 90 g carbohydrate per day for 28 days. Urine was collected for n-telopeptide (NTX), deoxypyridinoline (DPD), calcium, and pH determinations. Bone mineral content was determined and potential renal acid load was calculated. Bone-specific alkaline phosphatase was measured in serum samples collected on day 1 (immediately before bed rest) and on day 28. Potential renal acid load was higher in the AA group than in the Con group during bed rest (P < 0.05). For all subjects, during bed rest urinary NTX and DPD concentrations were greater than pre-bed rest levels (P < 0.05). Urinary NTX and DPD tended to be higher in the AA group (P = 0.073 and P = 0.056, respectively). During bed rest, urinary calcium was greater than baseline levels (P < 0.05) in the AA group but not the Con group. Total bone mineral content was lower after bed rest than before bed rest in the AA group but not the Con group (P < 0.05). During bed rest, urinary pH decreased (P < 0.05), and it was lower in the AA group than the Con group. These data suggest that bone resorption increased, without changes in bone formation, in the AA group.

Consequences of the Combined α-tocopherol, Ascorbic Acid and α-lipoic Acid on the Glutathione, Cholesterol and Fatty Acid Composition in Muscle and Liver of Diabetic Rats

PubMed Central

YILMAZ, Okkes; ERSAN, Yasemin; Dilek OZSAHIN, Ayse; Ihsan OZTURK, Ali; OZKAN, Yusuf

2013-01-01

Objective(s): Our objective was to evaluate the effects of a triple antioxidant combination [α-tocopherol (AT), ascorbic acid (AA) and α-lipoic acid (LA); AT+AA+LA] on the cholesterol and glutathione levels, and the fatty acid composition of liver and muscle tissues in diabetic rats. Materials and Methods: Forty-three Wistar rats were randomly divided into five groups. The first group was used as a control. The second, third and fourth groups received STZ (45 mg/kg) in citrate buffer. The fourth and fifth groups were injected with intraperitoneal (IP) 50 mg/kg DL-AT and 50 mg /kg DL-LA four times per week and received water-soluble vitamin C (50 mg/kg) in their drinking water for a period of six weeks. Results: Liver cholesterol levels in the AT+AA+LA group were lower than the control (P<0.05). Glutathione level was lower in D-2 (P<0.05) and were higher in D+AT+AA+LA and AT+AA+LA groups than the control groups (P≤ 0.05). The muscle cholesterol levels in the D-1 and D+AT+AA+LA groups were higher than the control group (P≤ 0.05). The levels of oleic acid were higher in the D-1 group and lower in the D-2 group (P<0.001). The arachidonic acid level in the D-1 and D-2 groups were lower (P<0.05), and higher in the D+AT+AA+LA group. Conclusion: Our results revealed that glutathione levels and the Stearoyl CoA Desaturase enzyme products in liver tissues of diabetic and non-diabetic rats were increased by triple antioxidant mixture. PMID:24298385

Consequences of the Combined α-tocopherol, Ascorbic Acid and α-lipoic Acid on the Glutathione, Cholesterol and Fatty Acid Composition in Muscle and Liver of Diabetic Rats.

PubMed

Yilmaz, Okkes; Ersan, Yasemin; Dilek Ozsahin, Ayse; Ihsan Ozturk, Ali; Ozkan, Yusuf

2013-02-01

Our objective was to evaluate the effects of a triple antioxidant combination [α-tocopherol (AT), ascorbic acid (AA) and α-lipoic acid (LA); AT+AA+LA] on the cholesterol and glutathione levels, and the fatty acid composition of liver and muscle tissues in diabetic rats. Forty-three Wistar rats were randomly divided into five groups. The first group was used as a control. The second, third and fourth groups received STZ (45 mg/kg) in citrate buffer. The fourth and fifth groups were injected with intraperitoneal (IP) 50 mg/kg DL-AT and 50 mg /kg DL-LA four times per week and received water-soluble vitamin C (50 mg/kg) in their drinking water for a period of six weeks. Liver cholesterol levels in the AT+AA+LA group were lower than the control (P<0.05). Glutathione level was lower in D-2 (P<0.05) and were higher in D+AT+AA+LA and AT+AA+LA groups than the control groups (P≤ 0.05). The muscle cholesterol levels in the D-1 and D+AT+AA+LA groups were higher than the control group (P≤ 0.05). The levels of oleic acid were higher in the D-1 group and lower in the D-2 group (P<0.001). The arachidonic acid level in the D-1 and D-2 groups were lower (P<0.05), and higher in the D+AT+AA+LA group. Our results revealed that glutathione levels and the Stearoyl CoA Desaturase enzyme products in liver tissues of diabetic and non-diabetic rats were increased by triple antioxidant mixture.

Dietary chlorogenic acid regulates gut microbiota, serum-free amino acids and colonic serotonin levels in growing pigs.

PubMed

Wu, Yi; Liu, Wenhui; Li, Qi; Li, Yafei; Yan, Yali; Huang, Fang; Wu, Xin; Zhou, Quancheng; Shu, Xugang; Ruan, Zheng

2018-08-01

Chlorogenic acid (CGA) has many biological properties, including antibacterial, antioxidant and anti-inflammatory properties, and is one of the most abundant phenolic acids available in the human diet. The aim of this study was to investigate the effects of CGA on regulation of the gut microbiota, and on the levels of free amino acids and 5-hydroxytryptamine (5-HT, serotonin). Ninety-six healthy growing pigs were randomly assigned to two treatment groups: the Ctrl group (control group, standard feed) and the CGA group [standard feed plus 0.05% 3-caffeoylquinic acid (3-CQA)] for 60 days. The diversity of the gut microbiota was increased after CGA supplementation. Changes in these microbes were significantly associated with the serum free amino acid levels and colonic 5-HT level. Compared with the Ctrl group, the levels of serum aspartic acid, threonine, alanine, arginine, and colonic 5-HT were significantly increased (p < .05). These data suggest important roles for CGA in regulating the gut microbiota and increasing the serum free amino acid levels.

[Studies on anaerobic infection in oro-maxillary region--rapid diagnosis by gas-liquid chromatography and antibiotic susceptibilities of anaerobic bacteria].

PubMed

Tanaka, J I

1989-08-01

Subject material for this study was pus collected from patients with purulent inflammation in the oro-maxillary region. Direct gas-liquid chromatography (GLC) analysis was made, bacterial isolation and identification were carried out, and comparisons were made with results from GLC analysis and anaerobic isolates in a PYG medium. In addition, antibiotic susceptibilities of anaerobic bacteria were examined. Results 1. Anaerobic bacteria were isolated from 85 of 100 cases of obstructive abscesses. Of the 85, 49 were cases of mixed infection involving both anaerobic and aerobic bacteria; and 64 cases were involved with more than 2 species of anaerobic bacteria. Of the 184 strains of anaerobic isolates, 53 were Bacteroides sp. and 51 were Peptostreptococcus sp. The 2 groups accounted for more than half of the isolates. 2. Group A, in which no VFA was detected, accounted for 17 out of 100 cases. Group B, in which acetic acid was detected, accounted for 20 cases; and Group C, in which butyric acid was detected, accounted for 20 cases; and Group D, in which iso-valeric acid was detected, accounted for 8 cases. Direct GLC analysis revealed iso-caproic and caproic acids in the 35 cases constituting Group E. 3. Whereas the percentage of anaerobic bacteria was 64.7% in Group A and 60% in Group B, significantly higher percentages were noted in Group C (95%), Group D (100%) and Group E (100%). The following species were isolated as major member in the groups; Group A--Streptococcus intermedius, Group B--Peptostreptococcus micros, Group C--Fusobacterium nucleatum, Group D--Bacteroides gingivalis, and Group E--Peptostreptococcus anaerobius. 4. In all cases, the sum of VFA produced in the PYG medium by anaerobic isolates was classified into Group A' to E'. Ratios of agreement between VFA as revealed by direct GLC and VFA as revealed by PYG.GLC were as follows: Group A-A'; 47.1%, Group B-B' and C-C'; 45%, Group D-D'; 87.5%, and Group E-E'; 62.9%. 5. In Group B, no propionic acid was detected. The 2 cases in which acetic acid occurred in a concentration greater than 14 x 10(-4) meq/ml belonged to Group B'. In Group C, no isobutyric acid was detected; and the 5 cases in which butyric acid was detected in a concentration of more than 7 x 10(-4) meq/ml belonged to Group C'. Varelic acid was not detected in Group D; and 7 out of the 8 cases in which iso-valeric acid, irrespective of concentration, was detected belonged to Group D'.(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of triple antioxidant combination (vitamin E, vitamin C and alpha-lipoic acid) with insulin on lipid and cholesterol levels and fatty acid composition of brain tissue in experimental diabetic and non-diabetic rats.

PubMed

Ozkan, Yusuf; Yilmaz, Okkeş; Oztürk, Ali Ihsan; Erşan, Yasemin

2005-09-01

The aim of this research was to examine the effects of a triple antioxidant combination (vitamins E (VE) and C (VC) plus alpha-lipoic acid (LA)) on the total lipid and cholesterol levels and the fatty acid composition of brain tissues in experimental diabetic and non-diabetic rats. VE and LA were injected intraperitoneally (50 mg/kg) four times per week and VC was provided as a supplement dissolved in the drinking water (50 mg/kg). In addition, rats in the diabetes 1 and D+VELAVC groups were given daily by subcutaneous insulin injections (8 IU/kg), but no insulin was given to rats in the diabetes 2 group. The results indicate that the brain lipid levels in the D+VELAVC, diabetes 1 and diabetes 2 groups were higher than in the control group (P<0.01). Total lipid was also higher in the non-diabetic rats treated with LA and VC. Total cholesterol was higher in the diabetes 1 and diabetes 2 groups (P<0.05) than in controls. Cholesterol levels were similar in the D+VELAVC and LA groups but lower in the VC, VE and VELAVC groups of non-diabetic rats (P<0.05 and P<0.01). In respect of fatty acid composition, palmitic acid levels were lower in the diabetes 2 and non-diabetic VE groups than the control group (P<0.05), but higher in the non-diabetic LA group (P<0.05). Oleic acid (18:1 n-9) levels were lower in the diabetic and non-diabetic groups than the control group (P<0.01), but higher in the non-diabetic LA group. Arachidonic acid (20:4 n-6) levels were similar in the diabetes 1, D+VELAVC and control groups (P>0.05) but higher in the non-diabetic VE, VC, LA and VEVCLA groups (P<0.05) and lower in the diabetes 2 group (P<0.05). Docosahexaenoic acid (22:6 n-3) was elevated in the diabetes 2 and VEVCLA groups (P<0.01, P<0.05). In conclusion, the current study confirmed that treatment with a triple combination of VE, VC and LA protects the arachidonic acid level in the brains of diabetic and non-diabetic rats.

Comparison of norfloxacin versus nalidixic acid in therapy of acute urinary tract infections

PubMed Central

Selin, Liisa K; Harding, Godfrey KM; Thomson, Margaret J; Kennedy, James K; Urias, Barbara A; Ronald, Allan R

1990-01-01

Thirty-seven adult patients with acute urinary tract infections (UTI) were randomized to receive either a seven day (lower UTI) or a 14 day (upper UTI) course of norfloxacin 400 mg orally twice daily, or nalidixic acid 1 g orally four times per day. Mean age, underlying disease and infecting organisms were similar in the two groups. Nine patients in the norfloxacin group and seven in the nalidixic acid group had presumptive evidence of upper UTI. Overall, 12 patients had antibody-coated bacteria-positive infections. The infecting organisms were: Escherichia coli (27), coagulase-negative staphylococci (four), Citrobacter freundii (three), Klebsiella pneumoniae (three), and Proteus mirabilis, Proteus vulgaris, Pseudomonas aeruginosa, Enterobacter agglomerans, Streptococcus agalactiae, Enterococcus faecalis (one of each). All of the organisms were susceptible to norfloxacin, while 81% were susceptible to nalidixic acid. The effects on the periurethral and anal canal flora were similar in both groups. Five patients in each group experienced adverse clinical effects. The cure rates for norfloxacin and nalidixic acid were 79 and 83%, respectively. There were two failures, two relapses and four reinfections in the norfloxacin group. In the nalidixic acid group, there were two failures, one relapse and four reinfections. One of the failure patients in the nalidixic acid group developed resistance to the drug, and two of the four reinfections were due to organisms resistant to nalidixic acid. In this patient population it was concluded that nalidixic acid may be as effective as norfloxacin in the treatment of acute, symptomatic UTI. PMID:22553437

Evaluation of the protective effect of α-lipoic acid on cisplatin ototoxicity using distortion-product otoacoustic emission measurements: an experimental animal study.

PubMed

Ozkul, Yilmaz; Songu, Murat; Basoglu, Mehmet Sinan; Ozturkcan, Sedat; Katilmis, Huseyin

2014-07-01

The aim of our study was to determine the effectiveness of intratympanic α-lipoic acid injection as an otoprotective agent against cisplatin-induced ototoxicity in guinea pigs. Twenty-four adult male albino guinea pigs with normal hearing were divided into 4 groups. The guinea pigs received intraperitoneal cisplatin in group 1, intraperitoneal cisplatin and intratympanic α-lipoic acid in group 2, intratympanic α-lipoic acid in group 3, as well as intraperitoneal cisplatin and intratympanic saline in group 4. Distortion-product otoacoustic emission measurements were obtained for both ears at the following time points: before administration (baseline recording) and on day 3 (72 h later). In group 1 (cisplatin), significant deterioration was observed at all frequencies on day 3 (P < 0.05). In group 2 (cisplatin + α-lipoic acid), deterioration was observed at all frequencies on day 3; however, this deterioration did not reach a statistical significance (P > 0.05). In group 3 (α-lipoic acid), no significant difference was observed between baseline and day 3 (P > 0.05). In group 4 (cisplatin + saline), deterioration was observed at all frequencies on day 3; however, this deterioration did not reach a statistical significance (P > 0.05). Cisplatin-induced hearing loss in the guinea pigs may be limited to some extent by the concomitant use of α-lipoic acid. Dose-dependent changes in the possible effects of α-lipoic acid need further investigation. Future morphologic studies may contribute to expose clearly the protective effect of α-lipoic acid.

Increased serum triglycerides and reduced HDL cholesterol in male rats after intake of ammonium chloride for 3 weeks

PubMed Central

2013-01-01

Background Previous data suggested that intake of sodas and other acid beverages might be associated with increased levels of serum triglycerides, lowered HDL cholesterol, and increased formation of mono unsaturated fatty acids, which are the preferred ones for triglyceride synthesis. The present work is an extension of these studies. Methods Thirty male rats were divided into 3 groups. All groups were given the same food, but various beverages: water (W), ammonium chloride, 200 mmol/L (AC), or sodium bicarbonate, 200 mmol/L (SB). Serum triglycerides, HDL cholesterol, and the fatty acid distribution in total serum lipids were determined. Delta9-desaturase in serum lipids was estimated by the ratio of palmitoleic to palmitic acid, and by the oleic/stearic acid ratio. Correlation and ANOVA were used to study associations and group differences. Results After 3 weeks, the AC group had higher triglyceride concentration and higher Delta9 desaturase indexes, but lower serum HDL and body weight as compared with the SB and W groups. In each of the groups, the oleic acid/stearic acid ratio correlated positively with serum triglycerides; in the pooled group the correlation coefficient was r = 0.963, p<0.01. Conclusions Rats ingesting ammonium chloride as compared with sodium bicarbonate responded with increased desaturase indexes, increased serum triglycerides, and lowered HDL cholesterol concentration, thereby possibly contributing to explain the increased triglyceride concentration previously observed in subjects with a frequent intake of acid beverages, such as sodas containing carbonic acid, citric acid, and phosphoric acid. PMID:23800210

Effects of tranexamic acid on coagulation indexes of patients undergoing heart valve replacement surgery under cardiopulmonary bypass.

PubMed

Liu, Fei; Xu, Dong; Zhang, Kefeng; Zhang, Jian

2016-12-01

This study aims to explore the effects of tranexamic acid on the coagulation indexes of patients undergoing heart valve replacement surgery under the condition of cardiopulmonary bypass (CPB). One hundred patients who conformed to the inclusive criteria were selected and divided into a tranexamic acid group and a non-tranexamic acid group. They all underwent heart valve replacement surgery under CPB. Patients in the tranexamic acid group were intravenously injected with 1 g of tranexamic acid (100 mL) at the time point after anesthesia induction and before skin incision and at the time point after the neutralization of heparin. Patients in the non-tranexamic acid group were given 100 mL of normal saline at corresponding time points, respectively. Then the coagulation indexes of the two groups were analyzed. The activated blood clotting time (ACT) of the two groups was within normal scope before CPB, while four coagulation indexes including prothrombin time (PT), activated partial thromboplastin time (APTT), international normalized ratio (INR), and fibrinogen (FIB) had significant increases after surgery; the PT and INR of the tranexamic acid group had a remarkable decline after surgery. All the findings suggest that the application of tranexamic acid in heart valve replacement surgery under CPB can effectively reduce intraoperative and postoperative blood loss. © The Author(s) 2016.

The effects of different lipid emulsions on the lipid profile, fatty acid composition, and antioxidant capacity of preterm infants: A double-blind, randomized clinical trial.

PubMed

Wang, Ying; Feng, Yi; Lu, Li-Na; Wang, Wei-Ping; He, Zhen-Juan; Xie, Li-Juan; Hong, Li; Tang, Qing-Ya; Cai, Wei

2016-10-01

Olive oil (OO), medium-chain triglycerides (MCT)/long-chain triglycerides (LCT) mixture and soybean oil (SO) lipid emulsions are currently used for preterm infants in China. The aim of our study was to compare the lipid profile, fatty acid composition, and antioxidant capacity of preterm infants administered OO, MCT/LCT, or SO lipid emulsions. In this study, 156 preterm infants (birth weight < 2000 g and gestational age < 37 weeks) received parenteral nutrition (PN) containing OO, MCT/LCT, or SO lipid emulsions for a minimum of 14 d. On days 0, 7, and 14, the lipid profile, fatty acid composition and antioxidant capacity were analyzed. On day 7, HDL levels in the MCT/LCT group were significantly lower than in the OO (1.06 ± 0.40 mmol/L) or SO groups. LDL levels were higher in the OO group than in the MCT/LCT or SO groups on day 7. A-I/B was higher in MCT/LCT than in OO or SO groups. Myristic acid (C14:0) levels on days 7 and 14 increased in MCT/LCT compared to the OO and SO groups. The OO group had higher oleic acid (C18:1n9) levels than the two other groups. Linoleic acid (C18:2n6), linolenic acid (C18:3n3), and eicosapentaenoic acid (20:5n3) were significantly lower in the OO group than in MCT/LCT or SO groups. Monounsaturated fatty acid levels decreased, and ω-6 polyunsaturated fatty acid and essential fatty acids levels increased in MCT/LCT and SO groups. No significant differences were obtained in SOD, MDA, GSH-Px, and T-AOC among the groups. The three lipid emulsions were safe and well tolerated in preterm infants. Oleic acid (C18:1n9) levels increased and LA (C18:2n6), ALA (C18:3n3), and EPA (C20:5n23) levels decreased in OO compared to MCT/LCT or SO. NCT01683162, https://register.clinicaltrials.gov/. Copyright © 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Chemopreventive effects of rofecoxib and folic acid on gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in rats.

PubMed

Fei, Su Juan; Xiao, Shu Dong; Peng, Yan Shen; Chen, Xiao Yu; Shi, Yao

2006-01-01

Epidemiological and experimental studies indicate that non-steroidal anti-inflammatory drugs (NSAIDs) are chemopreventive agents of gastrointestinal cancers, but few studies on gastric cancer have been carried out. A decrease in folic acid supplement and subsequent DNA hypomethylation are related to gastrointestinal cancers, and it has been shown that high-dose folic acid may interfere with gastric carcinogenesis in dogs. The objective of this study was to investigate the effects of rofecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, and folic acid on the chemoprevention of gastric cancer induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in Wistar rats, and to evaluate the cell proliferation of gastric mucosa in different experimental groups. Eighty male Wistar rats were randomly divided into five groups (16 rats in each group). In the control group, the rats were given pure water and basal diet. In the MNNG group, the rats received MNNG in drinking water (100 mg/L) and basal diet. In the MNNG + low-dose rofecoxib group, the rats were given MNNG and rofecoxib 5 mg/kg per day with basal diet. In the MNNG + high-dose rofecoxib group, the rats were given MNNG and rofecoxib 15 mg/kg per day with basal diet. In the MNNG + folic acid group, the rats were given MNNG and folic acid 5 mg/kg per day with basal diet. The experiment was terminated at 50 weeks, and all rats were killed. Blood samples of 3 mL were obtained for measurement of serum folic acid concentrations in the control group, the MNNG group and the MNNG + folic acid group by using chemiluminescent method. The stomach was removed from all rats for histopathological examination and immunohistochemical study. Proliferating cell nuclear antigen (PCNA) expression in gastric epithelial cells was also determined. In the MNNG group, five of 11 rats (45.5%) developed gastric cancer, while in all other four groups no gastric cancer was found (P < 0.05). The positivity rate of PCNA expression in the cancerous tissues was significantly higher than that in the non-cancerous tissues (80.0%vs 14.1%, P < 0.05). The positivity rate of PCNA expression in the gastric mucosal cells of the MNNG group was significantly higher than that in the other four groups. The mean serum folic acid concentration of rats was significantly higher in the MNNG + folic acid group (193.70 +/- 60.73 ng/mL) than those in the control group (84.21 +/- 25.26 ng/mL) and the MNNG group (72.27 +/- 16.70 ng/mL, P < 0.05). It was shown that both low- and high-dose rofecoxib as well as folic acid interfered with the development of gastric cancer induced by MNNG in Wistar rats. The results indicate that rofecoxib as well as folic acid interferes with gastric carcinogenesis induced by MNNG in Wistar rats, and the suppression of gastric cell proliferation may play a crucial role in the chemoprevention of gastric cancer by rofecoxib and folic acid. The higher serum folic acid concentration of rats may play an important role in the prevention of gastric cancer.

Blood fatty acid changes in healthy young Americans in response to a 10-week diet that increased n-3 and reduced n-6 fatty acid consumption: a randomised controlled trial.

PubMed

Young, Andrew J; Marriott, Bernadette P; Champagne, Catherine M; Hawes, Michael R; Montain, Scott J; Johannsen, Neil M; Berry, Kevin; Hibbeln, Joseph R

2017-05-01

Military personnel generally under-consume n-3 fatty acids and overconsume n-6 fatty acids. In a placebo-controlled, double-blinded study, we investigated whether a diet suitable for implementation in military dining facilities and civilian cafeterias could benefit n-3/n-6 fatty acid status of consumers. Three volunteer groups were provided different diets for 10 weeks. Control (CON) participants consumed meals from the US Military's Standard Garrison Dining Facility Menu. Experimental, moderate (EXP-Mod) and experimental-high (EXP-High) participants consumed the same meals, but high n-6 fatty acid and low n-3 fatty acid containing chicken, egg, oils and food ingredients were replaced with products having less n-6 fatty acids and more n-3 fatty acids. The EXP-High participants also consumed smoothies containing 1000 mg n-3 fatty acids per serving, whereas other participants received placebo smoothies. Plasma and erythrocyte EPA and DHA in CON group remained unchanged throughout, whereas EPA, DHA and Omega-3 Index increased in EXP-Mod and EXP-High groups, and were higher than in CON group after 5 weeks. After 10 weeks, Omega-3 Index in EXP-High group had increased further. No participants exhibited changes in fasting plasma TAG, total cholesterol, LDL, HDL, mood or emotional reactivity. Replacing high linoleic acid (LA) containing foods in dining facility menus with similar high oleic acid/low LA and high n-3 fatty acid foods can improve n-6/n-3 blood fatty acid status after 5 weeks. The diets were well accepted and suitable for implementation in group feeding settings like military dining facilities and civilian cafeterias.

Quality and fatty acid profile of the milk of indigenous goats subjected to different local diets in Tunisian arid lands.

PubMed

Ayeb, N; Addis, M; Fiori, M; Khorchani, S; Atigui, M; Khorchani, T

2016-02-01

The study tested the hypothesis that certain pastoral forages and olive by-products, available in arid areas, may positively influence fatty acid composition and physicochemical properties of goat's milk. Thirty indigenous goats (body weight = 25.2 kg; age = 4.1 years) were allocated to three groups. During 60 days, the goats received ad libitum either dried olive leaves + Stipa tenacissima (group OL), khortane grass hay (group Ko) or oat hay (control diet, group OH). Milk samples were collected and analysed for total solids, fat, protein, lactose and ash content and fatty acid profile. Average milk yield did not statistically differ among groups. Milk total solids from OL group were higher in comparison with Ko and C groups (15.3, 14.7 and 14.5%, respectively; p < 0.05). Fat content was also higher for the OL group as compared to the other groups (5.44 vs. 5.01 and 4.66%, respectively, for Ko and OH). No significant differences were observed for the milk content of lactose, protein and ash. The percentage of saturated fatty acids of total milk fat was higher in OL and Ko groups compared to the C group (p < 0.001); the milk whereof was characterized by the highest percentage of monounsaturated (p < 0.01) and total unsaturated fatty acids. Milk fat of Ko and C groups showed significantly higher proportions of rumenic (CLA cis-9 trans-11) and vaccenic acids (C18:1 trans-11) compared to OL milk. The feeding system based on Stipa tenacissima and dried olive leaves resulted in the milk lowest proportion of trans-fatty acids and the highest proportion of polyunsaturated ω3-fatty acids (p < 0.05). Journal of Animal Physiology and Animal Nutrition © 2015 Blackwell Verlag GmbH.

Effect of lipoic acid combined with paclitaxel on breast cancer cells.

PubMed

Li, B J; Hao, X Y; Ren, G H; Gong, Y

2015-12-22

Breast cancer is the most common gynecologic tumor globally that threatens women's health. Lipoic acid is a type of antioxidant that can alleviate oxidative stress damage. Studies showed that lipoic acid could inhibit the proliferation of tumor cells in cervical cancer and colon cancer. This paper intends to explore the combined effect of lipoic acid and paclitaxel on breast cancer cells. Breast cancer MCF-7 cells were divided into four groups: control group, lipoic acid group, paclitaxel group, and a combination group. MTT was applied to detect the drugs' influence on breast cancer cell proliferation. A colony formation test was used to determine the effects on breast cancer cell clone formation rate. Western blot was performed to detect the effects on nuclear factor (NF)-κB. Lipoic acid alone can inhibit tumor cell proliferation and clone formation with time dependence. Compared with the control, paclitaxel alone can significantly suppress tumor cell proliferation and clone formation (P < 0.05). Lipoic acid and paclitaxel in combination obviously strengthened their individual inhibitory effects on tumor cells (P < 0.05). Compared with the paclitaxel alone group, the combination group exhibited more remarkable inhibitory effect (P < 0.05). Lipoic acid alone or combined with paclitaxel can inhibit NF-κB expression and inhibit breast cancer cell proliferation.

The antioxidant and antiapoptotic effect of boric acid on hepatoxicity in chronic alcohol-fed rats.

PubMed

Sogut, Ibrahim; Paltun, Sıla Ozlem; Tuncdemir, Matem; Ersoz, Melike; Hurdag, Canan

2018-04-01

The harmful use of alcohol is a worldwide problem involving all ages. This study aims to investigate chronic alcohol exposure related hepatotoxicity on the rat liver and possible hepatoprotective effects of boric acid. Rats were separated into 4 different groups: control, ethanol, ethanol+boric acid, and boric acid. We measured (i) malondialdehyde (MDA), total sialic acid (TSA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) levels, which are known to be the markers of alcohol damage; and also (ii) caspase-3, tumor necrosis factor-alpha (TNF-α), and the terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) as the markers of apoptosis. In the ethanol group, MDA, TSA, and TNF-α levels increased whereas SOD and CAT levels decreased compared with the control group. Ethanol+boric acid group MDA, TSA, caspase-3, and TNF-α levels decreased whereas SOD and CAT levels increased compared with the ethanol group. Using histopathological evaluation of light microscope images, immunohistochemical caspase-3 and TNF-α activity in the ethanol+boric acid group were shown to be decreased compared with that in the ethanol group. Our results revealed that ethanol is capable of triggering oxidative stress and apoptosis in the rat liver. We propose that boric acid is an effective compound in protecting the rat liver against ethanol.

Plasma fatty acid profile and alternative nutrition.

PubMed

Krajcovicová-Kudlácková, M; Simoncic, R; Béderová, A; Klvanová, J

1997-01-01

Plasma profile of fatty acids was examined in a group of children consisting of 7 vegans, 15 lactoovovegetarians and 10 semivegetarians. The children were 11-15 years old and the average period of alternative nutrition was 3.4 years. The results were compared with a group of 19 omnivores that constituted an average sample with respect to biochemical and hematological parameters from a larger study of health and nutritional status of children in Slovakia. Alternative nutrition groups had significantly lower values of saturated fatty acids. The content of oleic acid was identical to omnivores. A significant increase was observed for linoleic and alpha-linolenic (n-3) acids. The dihomo-gamma-linolenic (n-6) acid and arachidonic (n-6) acid values were comparable to omnivores for all alternative nutrition groups. Values of n-3 polyunsaturated fatty acids in lactoovovegetarians were identical to those of omnivores whereas they were significantly increased in semivegetarians consuming fish twice a week. Due to the total exclusion of animal fats from the diet, vegans had significantly reduced values of palmitoleic acid as well as eicosapentaenoic (n-3) acid and docosahexaenoic (n-3) acid resulting in an increased n-6/n-3 ratio. Values of plasma fatty acids found in alternative nutrition groups can be explained by the higher intake of common vegetable oils (high content of linoleic acid), oils rich in alpha-linolenic acid (cereal germs, soybean oil, walnuts), as well as in n-3 polyunsaturated fatty acids (fish). The results of fatty acids (except n-3 in vegans) and other lipid parameters confirm the beneficial effect of vegetarian nutrition in the prevention of cardiovascular diseases.

Docosahexaenoic Acid and Eicosapentaenoic Acid Did not Alter trans-10,cis-12 Conjugated Linoleic Acid Incorporation into Mice Brain and Eye Lipids.

PubMed

Vemuri, Madhuri; Adkins, Yuriko; Mackey, Bruce E; Kelley, Darshan S

2017-09-01

trans 10,cis 12-CLA has been reported to alter fatty acid composition in several non-neurological tissues, but its effects are less known in neurological tissues. Therefore, the purpose of this study was to determine if CLA supplementation would alter brain and eye fatty acid composition and if those changes could be prevented by concomitant supplementation with docosahexaenoic acid (DHA; 22:6n3) or eicosapentaenoic acid (EPA; 20:5n3). Eight-week-old, pathogen-free C57BL/6N female mice (n = 6/group) were fed either the control diet or diets containing 0.5% (w/w) t10,c12-CLA in the presence or absence of either 1.5% DHA or 1.5% EPA for 8 weeks. CLA concentration was significantly (P < 0.05) greater in the eye but not in the brain lipids of the CLA group when compared with the control group. The sums of saturated, monounsaturated, polyunsaturated fatty acids, and n3:n6 ratio did not differ between these two groups for both tissues. The n3:n6 ratio and concentrations of 20:5n3 and 22:5n3 were significantly greater, and those of 20:4n6, 22:4n6, and 22:5n6 were lesser in the CLA + DHA and CLA + EPA groups than in the control and CLA groups for either tissue. DHA concentration was higher in the CLA + DHA group only but not in the CLA + EPA group when compared with the CLA group for both tissues. The dietary fatty acids generally induced similar changes in brain and eye fatty acid concentration and at the concentrations used both DHA and EPA fed individually with CLA were more potent than CLA alone in altering the tissue fatty acid concentration.

Effects of the food additive, citric acid, on kidney cells of mice.

PubMed

Chen, Xg; Lv, Qx; Liu, Ym; Deng, W

2015-01-01

Citric acid is a food additive that is widely used in the food and drink industry. We investigated the effects of citric acid injection on mouse kidney. Forty healthy mice were divided into four groups of 10 including one control group and three citric acid-treated groups. Low dose, middle dose and high dose groups were given doses of 120, 240 and 480 mg/kg of citric acid, respectively. On day 7, kidney tissues were collected for histological, biochemical and molecular biological examination. We observed shrinkage of glomeruli, widened urinary spaces and capillary congestion, narrowing of the tubule lumen, edema and cytoplasmic vacuolated tubule cells, and appearance of pyknotic nuclei. The relation between histopathological changes and citric acid was dose dependent. Compared to the control, T-SOD and GSH-Px activities in the treated groups decreased with increasing doses of citric acid, NOS activity tended to increase, and H2O2 and MDA contents gradually decreased, but the differences between any treated group and the control were not statistically significant. The apoptosis assay showed a dose-dependent increase of caspase-3 activity after administering citrate that was statistically significant. DNA ladder formation occurred after treatment with any dose of citric acid. We concluded that administration of citric acid may cause renal toxicity in mice.

[EFFECT OF α-LIPOIC ACID IN INHIBITING OXIDATIVE STRESS AND PROMOTING DIABETIC WOUND HEALING BY SUPPRESSING EXPRESSION OF miR-29b IN MICE].

PubMed

Wu, Jun; Tang, Huiqin; Liu, Qun; Gan, Dingyun; Zhou, Man

2016-08-08

To investigate the effect of α-lipoic acid on the oxidative stress of wound tissues and diabetic wound healing in mice with diabetic feet. Sixty male C57BL/6J mice weighting 200-300 g were randomly divided into model group (control group, n =15), α-lipoic acid-treated model group ( n =15), miR-29b mimic group ( n =15), and miR-29b mimic negative control group (NC group, n =15). All animals received intraperitoneal injection of streptozocin to establish the diabetic model. Then, a full thickness wound of 5 mm×2 mm in size was created at 4 weeks after modeling. All mice were administrated with high-sugar-fat-diet. At the same day after modeling, α-lipoic acid-treated model group was continuously given intravenous injection of 100 mg/(kg·d) α-lipoic acid for 14 days; miR-29b mimic group and NC group received the tail intravenous injection of lentiviral vector for miR-29b mimic and miR-29b mimic negative control (a total of 2×10 7 TU), respectively, with the treatment of α-lipoic acid. The wound healing was observed and wound area was measured at 7 and 14 days. The wound tissues were harvested to detect the levels of superoxide dismutase (SOD) and glutathione (GSH) using xanthine oxidase method and 5, 5-dithiobis-2-nitrobenzoic acid staining method at 14 days. At the same day, 7, and 14 days after modeling, the relative miR-29b expression in wound tissues from control and α-lipoic acid-treated model groups was detected by real-time fluorescence quantitative PCR. All mice survived to the experiment end. The wound healing was faster in α-lipoic acid-treated group than control group. At 7 and 14 days, the relative wound area and miR-29b expression level were significantly lower, while the contents of SOD and GSH were significantly higher in α-lipoic acid-treated group than control group ( P <0.05). In addition, miR-29b mimic group had significantly increased relative wound area and significantly decreased the contents of SOD and GSH when compared with NC group at 7 and 14 days ( P <0.05). α-lipoic acid could inhibit oxidative stress and promote diabetic wound healing by suppressing expression of miR-29b in mice.

Topical zinc oxide vs. salicylic acid-lactic acid combination in the treatment of warts.

PubMed

Khattar, Joe A; Musharrafieh, Umayya M; Tamim, Hala; Hamadeh, Ghassan N

2007-04-01

Warts are a common dermatologic problem. Treatment is painful, prolonged, and can cause scarring. To evaluate topical zinc oxide for the treatment of warts. This was a randomized, double-blind controlled trial of 44 patients. Twenty-two patients were given topical zinc oxide 20% ointment, and the other 22 received salicylic acid 15% + lactic acid 15% ointment twice daily. All patients were followed up for 3 months or until cure, whichever occurred first. All patients were observed for side-effects. Sixteen patients in the zinc group and 19 in the salicylic acid-lactic acid group completed the study. In the zinc oxide-treated group, 50% of the patients showed complete cure and 18.7% failed to respond, compared with 42% and 26%, respectively, in the salicylic acid-lactic acid-treated group. No patients developed serious side-effects. Topical zinc oxide is an efficacious, painless, and safe therapeutic option for wart treatment.

Hydrogen-bonded aggregates in precise acid copolymers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lueth, Christopher A.; Bolintineanu, Dan S.; Stevens, Mark J., E-mail: msteve@sandia.gov

2014-02-07

We perform atomistic molecular dynamics simulations of melts of four precise acid copolymers, two poly(ethylene-co-acrylic acid) (PEAA) copolymers, and two poly(ethylene-co-sulfonic acid) (PESA) copolymers. The acid groups are spaced by either 9 or 21 carbons along the polymer backbones. Hydrogen bonding causes the acid groups to form aggregates. These aggregates give rise to a low wavevector peak in the structure factors, in agreement with X-ray scattering data for the PEAA materials. The structure factors for the PESA copolymers are very similar to those for the PEAA copolymers, indicating a similar distance between aggregates which depends on the spacer length butmore » not on the nature of the acid group. The PEAA copolymers are found to form more dimers and other small aggregates than do the PESA copolymers, while the PESA copolymers have both more free acid groups and more large aggregates.« less

Comparison between topical and intravenous administration of tranexamic acid in primary total hip arthroplasty.

PubMed

Ueno, Masaya; Sonohata, Motoki; Fukumori, Norio; Kawano, Shunsuke; Kitajima, Masaru; Mawatari, Masaaki

2016-01-01

Tranexamic acid has been reported to be safer with topical administration than with intravenous administration in total knee arthroplasty. However, the most effective administration route of tranexamic acid in total hip arthroplasty remains controversial. This study compared the effectiveness of topical tranexamic acid administration with that of intravenous tranexamic acid administration in total hip arthroplasty. We retrospectively examined the medical records of 886 patients with osteoarthritis of the hip joint, who had undergone unilateral primary total hip arthroplasty. The patients were divided into a control group (n = 302; did not receive tranexamic acid), topical group (n = 265; topically administered 2 g tranexamic acid in 30 mL normal saline via drain tubes placed in the joint before wound closure along with posterior soft tissue repair), and intravenous group (n = 319; intravenously administered 1 g tranexamic acid before skin incision along with posterior soft tissue repair). Data on blood loss, hemoglobin levels, transfusion rates, and occurrence of deep vein thrombosis and pulmonary embolization were collected. The mean operation times were approximately 40 min in all of the groups. The operation time and intra-operative blood loss were significantly lower in the control group than in the topical and intravenous groups. However, the post-operative blood loss, total blood loss, and decrease in the hemoglobin level were significantly higher in the control group than in the topical and intravenous groups. There were no significant differences in terms of blood loss and systemic complications between the tranexamic acid administration methods. Tranexamic acid reduces both post-operative and total blood loss in total hip arthroplasty. Moreover, a lower amount of tranexamic acid can be used to reduce blood loss in total hip arthroplasty with intravenous tranexamic acid administration than with topical tranexamic acid administration. Therefore, we suggest that tranexamic acid should be intravenously administered pre-operatively and the posterior soft tissue should be repaired to decrease total hip arthroplasty-related complications. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

The importance of lactic acid in migraines and fibromyalgia.

PubMed

de Sá Ribeiro, Guido Assis Cachuba; Scola, Rosana Hermínia; Piovesan, Elcio Juliato; Wollmann Junior, Darley Rugeri; Paiva, Eduardo Dos Santos; da Cunha, Claudio Leinig Pereira; Werneck, Lineu Cesar

2015-01-01

Lactic acid is a byproduct of both muscle metabolism and the central nervous system. Changes in metabolism are related to various physiological and pathological conditions. The aim of this study was to determine the relationship between migraine and fibromyalgia with the levels of lactic acid in the blood. We study of 93 patients was divided into five groups: 1) patients with fibromyalgia (n=20); 2) episodic migraine (n=20); 3) chronic migraine (n=20); 4) fibromyalgia and episodic migraine (n= 13); and 5) fibromyalgia and chronic migraine (n=20), and 20 healthy subjects (control group). Blood levels of lactic acid were measured at four different time points: at rest, during aerobic exercise, during anaerobic physical activity and while resting after anaerobic exercise. Lactic acid increased in all groups during anaerobic physical activity without predominance for either group. During aerobic physical activity, all groups increased lactic acid levels, but the increase was more expressive in the chronic migraine group and the chronic migraine with fibromyalgia group without statistical significance. We did not found abnormalities involving the metabolism of lactic acid in episodic and chronic migraine with or without fibromyalgia. Copyright © 2015 Elsevier Editora Ltda. All rights reserved.

Interaction of silicene with amino acid analogues—from physical to chemical adsorption in gas and solvated phases

NASA Astrophysics Data System (ADS)

Jagvaral, Yesukhei; He, Haiying; Pandey, Ravindra

2018-01-01

Silicene is an emerging 2D material, and an understanding of its interaction with amino acids, the basic building blocks of protein, is of fundamental importance. In this paper, we investigate the nature of adsorption of amino-acid analogues on silicene employing density functional theory and an implicit solvation model. Amino acid analogues are defined as CH3-R molecules, where R is the functional group of the amino acid side chain. The calculated results find three distinct groups within the amino-acid analogues considered: (i) group I, which includes MeCH3 and MeSH, interacts with silicene via the van der Waals dispersive terms leading to physisorbed configurations; (ii) group II strongly interacts with silicene forming Si-O/N chemical bonds in the chemisorbed configurations; and (iii) group III, which consists of the phenyl group, interacts with silicene via π-π interactions leading to physisorbed configurations. The results show that the lateral chains of the amino acids intrinsically determine the interactions between protein and silicene at the interface under the given physiological conditions.

Expression and role of the genes involved in the transport of bile acids in the liver and kidneys in mice.

PubMed

Attakpa, Eugène S; Djibril, Naguibou M; Baba-Moussa, Farid; Yessoufou, Ganiou; Sezan, Alphonse

2013-01-01

Bile acids are synthesized in the liver from cholesterol. This study investigated the impact and expression of different carriers of bile acid in the liver and kidneys. Eight-week-old male mice were used, which were fed for 15 days and divided into two groups: 15 mice fed with standard diet (control group) and another 15 mice fed with a rich diet of 5% cholesterol (second group). Bile acid dosage was based on their oxidation by 7α hydroxyl-steroid dehydrogenize. The mRNA expression was quantitatively analyzed by the real time of polymerase chain reaction (RT-PCR), and the expression of the renal carrier bile acid protein was analyzed by Western blot. The expression of bile salt export pump involved in the uptake of bile acids in the basolateral membrane of hepatocytes revealed no differences between the two groups of mice. However, the expression of multidrug resistance-associated protein 2 was reduced in mice of the second group. Moreover, the expressions of organic anion transporting polypeptide 4, organic anion transporting polypeptide 1, and sodium taurocholate co-transporting polypeptide (Ntcp) involved in the uptake of bile acids in the apical pole of hepatocytes are suppressed in mice of the second group. The expression of multidrug resistance-associated protein 3 involved in the secretion of bile acids in the apical membrane of hepatocytes revealed no significant differences between the two groups. In mice of the second group, blood concentration of bile acids on the last day was increased. In those mice, the expression of intestinal bile acid transporter was reduced in the kidneys compared with the control mice.

Breast-cancer adjuvant therapy with zoledronic acid.

PubMed

Coleman, Robert E; Marshall, Helen; Cameron, David; Dodwell, David; Burkinshaw, Roger; Keane, Maccon; Gil, Miguel; Houston, Stephen J; Grieve, Robert J; Barrett-Lee, Peter J; Ritchie, Diana; Pugh, Julia; Gaunt, Claire; Rea, Una; Peterson, Jennifer; Davies, Claire; Hiley, Victoria; Gregory, Walter; Bell, Richard

2011-10-13

Data suggest that the adjuvant use of bisphosphonates reduces rates of recurrence and death in patients with early-stage breast cancer. We conducted a study to determine whether treatment with zoledronic acid, in addition to standard adjuvant therapy, would improve disease outcomes in such patients. In this open-label phase 3 study, we randomly assigned 3360 patients to receive standard adjuvant systemic therapy either with or without zoledronic acid. The zoledronic acid was administered every 3 to 4 weeks for 6 doses and then every 3 to 6 months to complete 5 years of treatment. The primary end point of the study was disease-free survival. A second interim analysis revealed that a prespecified boundary for lack of benefit had been crossed. At a median follow-up of 59 months, there was no significant between-group difference in the primary end point, with a rate of disease-free survival of 77% in each group (adjusted hazard ratio in the zoledronic acid group, 0.98; 95% confidence interval [CI], 0.85 to 1.13; P=0.79). Disease recurrence or death occurred in 377 patients in the zoledronic acid group and 375 of those in the control group. The numbers of deaths--243 in the zoledronic acid group and 276 in the control group--were also similar, resulting in rates of overall survival of 85.4% in the zoledronic acid group and 83.1% in the control group (adjusted hazard ratio, 0.85; 95% CI, 0.72 to 1.01; P=0.07). In the zoledronic acid group, there were 17 confirmed cases of osteonecrosis of the jaw (cumulative incidence, 1.1%; 95% CI, 0.6 to 1.7; P<0.001) and 9 suspected cases; there were no cases in the control group. Rates of other adverse effects were similar in the two study groups. These findings do not support the routine use of zoledronic acid in the adjuvant management of breast cancer. (Funded by Novartis Pharmaceuticals and the National Cancer Research Network; AZURE Current Controlled Trials number, ISRCTN79831382.).

The Effect of Ascorbic Acid and Garlic Administration on Lead-Induced Neural Damage in Rat Offspring's Hippocampus.

PubMed

Sadeghi, Akram; Ebrahimzadeh Bideskan, Alireza; Alipour, Fatemeh; Fazel, Alireza; Haghir, Hossein

2013-02-01

The aim of this study was to investigate ascorbic acid and garlic protective effects on lead-induced neurotoxicity during rat hippocampus development. 90 pregnant wistar rats were divided randomly into nine groups: 1- Animals received leaded water (L). 2- Rats received leaded water and ascorbic acid (L+AA). 3- Animals received leaded water and garlic juice (L+G). 4-Animals received leaded water, ascorbic acid and garlic juice (L+G+AA). 5- Rats treated with ascorbic acid (AA). 6- Rats treated with garlic juice (G). 7- Rats treated with ascorbic acid and garlic juice (AA+G). 8- Rats treated with tap water plus 0.4 ml/l normal hydrogen chloride (HCl) and 0.5 mg/l Glucose (Sham). 9- Normal group (N). Leaded water (1500 ppm), garlic juice (1 ml/100g/day, gavage) and ascorbic acid (500 mg/kg/day, IP) were used. Finally, blood lead levels (BLL) were measured in both rats and their offspring. The rat offspring brain sections were stained using Toluidine Blue and photographed. Dark neurons (DNs) were counted to compare all groups. BLL significantly increased in L group compared to control and sham groups and decreased in L+G and L+AA groups in comparison to the L group (P<0.05). the number of DNs in the CA1, CA3, and DG of rat offspring hippocampus significantly increased in L group in comparison to control and sham groups (P<0.05) and decreased in L+G and L+AA groups compared to L group (P<0.05). Garlic juice and ascorbic acid administration during pregnancy and lactation may protect lead-induced neural damage in rat offspring hippocampus.

Unraveling the impact of hydroxylation on interactions of bile acid cationic lipids with model membranes by in-depth calorimetry studies.

PubMed

Singh, Manish; Bajaj, Avinash

2014-09-28

We used eight bile acid cationic lipids differing in the number of hydroxyl groups and performed in-depth differential scanning calorimetry studies on model membranes doped with different percentages of these cationic bile acids. These studies revealed that the number and positioning of free hydroxyl groups on bile acids modulate the phase transition and co-operativity of membranes. Lithocholic acid based cationic lipids having no free hydroxyl groups gel well with dipalmitoylphosphatidylcholine (DPPC) membranes. Chenodeoxycholic acid lipids having one free hydroxyl group at the 7'-carbon position disrupt the membranes and lower their co-operativity. Deoxycholic acid and cholic acid based cationic lipids have free hydroxyl groups at the 12'-carbon position, and at 7'- and 12'-carbon positions respectively. Doping of these lipids at high concentrations increases the co-operativity of membranes suggesting that these lipids might induce self-assembly in DPPC membranes. These different modes of interactions between cationic lipids and model membranes would help in future for exploring their use in DNA/drug delivery.

Higher cord blood levels of fatty acids in pregnant women with type 1 diabetes mellitus.

PubMed

Djelmis, Josip; Ivaniševic, Marina; Desoye, Gernot; van Poppel, Mireille; Berberovic, Edina; Soldo, Dragan; Oreskovic, Slavko

2018-05-01

Type 1 diabetes mellitus is associated with a disturbance of carbohydrate and lipid metabolism. To determine whether type 1 diabetes mellitus (T1DM) alters maternal and neonatal fatty acid levels. Observational study. Academic hospital. Sixty pregnant women (30 women with T1DM with good glycemic control and 30 healthy women) were included in the study. Maternal blood, umbilical vein and artery blood samples were collected immediately upon delivery. Following lipid extraction, the fatty acid profiles of the total fatty acid pool of maternal serum and umbilical vein and artery serum were determined by gas chromatography. Total fatty acid concentration in maternal serum did not differ between the study groups; it was significantly higher in umbilical vein serum of the T1DM group compared with that in the control group, median (interquartile range), T1DM: 2126.2 (1446.4 - 3181.3), control: 1073.8 (657.5 - 2226.0); (P<0.001) and in umbilical artery vein serum T1DM: 1805.7 (1393.1 - 2125.0), control: 990.0 (643.3 - 1668.0); (P<0.001). Composition of fatty acids in umbilical vein serum fatty acids showed significantly higher concentrations of saturated, monounsaturated and polyunsaturated fatty acids in the T1DM group than in compared with those in the control group (P=0.001). Also cord blood levels of leptin (P<0.001), C-peptide (P<0.001), and insulin resistance (P=0.015) were higher in the T1DM group compared to controls. The neonates born to T1DM mothers had higher concentrations of total fatty acids, saturated and monounsaturated fatty acids, as well as polyunsaturated fatty acids, compared to control group newborns.

Heterogeneous chain dynamics and aggregate lifetimes in precise acid-containing polyethylenes: Experiments and simulations

DOE PAGES

Middleton, L. Robert; Tarver, Jacob D.; Cordaro, Joseph; ...

2016-11-10

Melt state dynamics for a series of strictly linear polyethylenes with precisely spaced associating functional groups were investigated. The periodic pendant acrylic acid groups form hydrogen-bonded acid aggregates within the polyethylene (PE) matrix. The dynamics of these nanoscale heterogeneous morphologies were investigated from picosecond to nanosecond timescales by both quasi-elastic neutron scattering (QENS) measurements and fully atomistic molecular dynamics (MD) simulations. Two dynamic processes were observed. The faster dynamic processes which occur at the picosecond timescales are compositionally insensitive and indicative of spatially restricted local motions. The slower dynamic processes are highly composition dependent and indicate the structural relaxation ofmore » the polymer backbone. Higher acid contents, or shorter PE spacers between pendant acid groups, slow the structural relaxation timescale and increase the stretching parameter (β) of the structural relaxation. Additionally, the dynamics of specific hydrogen atom positions along the backbone correlate structural heterogeneity imposed by the associating acid groups with a mobility gradient along the polymer backbone. At time intervals (<2 ns), the mean-squared displacements for the four methylene groups closest to the acid groups are up to 10 times smaller than those of methylene groups further from the acid groups. At longer timescales acid aggregates rearrange and the chain dynamics of the slow, near-aggregate regions and the faster bridge regions converge, implying a characteristic timescale for the passage of chains between aggregates. As a result, the characterization of the nanoscale chain dynamics in these associating polymer systems both provides validation of simulation force fields and provides understanding of heterogeneous chain dynamics in associating polymers.« less

Comparison the effectiveness of pyruvic acid 50% and salicylic acid 30% in the treatment of acne.

PubMed

Jaffary, Fariba; Faghihi, Gita; Saraeian, Sara; Hosseini, Sayed Mohsen

2016-01-01

Acne vulgaris is a chronic inflammatory disease of the pilosebaceous follicles and one of the most common skin diseases. The peeling method has been recently found to be effective for acne treatment. This study aimed to compare the efficacy of pyruvic acid 50% and salicylic acid 30% peeling in the treatment of mild to moderate acne. In a prospective single-blinded clinical trial, 86 patients with acne were randomly assigned into two groups. In both groups, the routine treatment of acne (topical solution of erythromycin 4%, triclorocarban soap, and sunscreen) were used twice a day for 8 weeks. In addition, salicylic acid 30% for the control group and pyruvic acid 50% for the case group were used. In both groups, acne severity index (ASI) was calculated before and at week 2, 4, 6, and 8 of the treatment. Patient satisfaction was assessed at the end of the treatment. Side effects were recorded using a checklist. In both groups, the reduction in the number of comedones, papules, and ASI were statistically significant ( P < 0.001) in the course of treatment. However, it was not significant regarding the number of pustules ( P = 0.09). None of the number of comedone, papules, pustules, and ASI was statistically different between study groups. Both treatment groups had similar side effects except for scaling in the fifth session, which was significantly lower in salicylic acid - treated patients ( P = 0.015). Both pyruvic acid 50% and salicylic acid 30% are effective in the improvement of mild to moderate acne with no significant difference in efficacy and side effects.

[Effects of excess folic acid on growth and metabolism of water-soluble vitamins in weaning rats].

PubMed

Fukuwatari, Tsutomu; Shibata, Katsumi

2008-02-01

In order to determine the tolerable upper intake level of folic acid in humans, we investigated the effects of excessive folic acid administration on the body weight gain, food intake, tissue weight, and metabolism of B-group vitamins in weaning rats. The rats were freely fed ordinary diet containing 0.0002% folic acid (control diet) or the same diet with 0.01%, 0.1%, or 1.0% folic acid for 29 days. The body weight gains and food intakes did not differ among the four groups. Diarrhea was not seen even in the 1.0% group. Excess folic acid did not affect the tissue weights of the brain, heart, liver, kidney, spleen, lung, or testis, or urinary excretion of other B-group vitamins. These results clearly showed that feeding a diet containing up to 1.0% folic acid did not affect the food intake, body weight gain, tissue weight, or urinary excretion of B-group vitamins in weaning rats.

Analysis of hyaluronic acid concentration in rat vocal folds during estral and gravidic puerperal cycles.

PubMed

Pedroso, José Eduardo de Sá; Brasil, Osíris Camponês do; Martins, João Roberto Maciel; Nader, Helena Bociane; Simões, Manuel de Jesus

2009-01-01

Hormone plays an important role in the larynx. Among other substances, vocal folds contain hyaluronic acid, which tissue concentration may vary according to hormone action. the objective of this study is to analyze hyaluronic acid concentration in the vocal folds during estral and gravidic-puerperal cycles. Experimental study. 40 adult rats were divided into two groups. In the first group we used 20 rats to establish the concentration of hyaluronic acid during the estral cycle and in the second group, 20 animals were submitted to the same procedure but during the gravidic-puerperal cycle. Variations in hyaluronic acid concentration was not observed during the estral cycle. In the gravidic puerperal cycle group, an increase in hyaluronic acid concentration was observed in the puerperal subgroup. Comparing the two groups of estral and gravidic-puerperal cycles, no difference was observed. In comparing all subgroups of estral and gravidic-puerperal cycles, an increase in hyaluronic acid concentration was noticed only in the puerperal phase.

Synthesis and characterization of bifunctional surfaces with tunable functional group pairs

NASA Astrophysics Data System (ADS)

Galloway, John M.; Kung, Mayfair; Kung, Harold H.

2016-06-01

Grafting of pairs of functional groups onto a silica surface was demonstrated by tethering both terminals of an organochlorosilane precursor molecule, Cl2(CH3)Si(CH2)4(CO)(OSi(i-Pr)2)(CH2)2Si(CH3)Cl2, that possess a cleavable silyl ester bond, onto a silica surface. Hydrolytic cleavage of the silyl ester bond of the grafted molecule resulted in the generation of organized pairs of carboxylic acid and organosilanol groups. This organosilanol moiety was easily transformed into other functional groups through condensation reactions to form, together with the neighboring acid group, pairs such as carboxylic acid/secondary amine, carboxylic acid/pyridine, and carboxylic acid/phosphine. In the case of carboxylic acid/amine pairing, there was evidence of the formation of amide. A sample grafted with amine-carboxylic acid pairs was three times more active (per free amine) than a sample without such pairs for the nitroaldol condensation of 4-nitrobenzaldehyde and nitromethane.

Comparing Amino Acid Abundances and Distributions Across Carbonaceous Chondrite Groups

NASA Technical Reports Server (NTRS)

Burton, Aaron S.; Callahan, Michael P.; Glavin, Daniel P.; Elsila, Jamie E.; Dworkin, Jason P.

2012-01-01

Meteorites are grouped according to bulk properties such as chemical composition and mineralogy. These parameters can vary significantly among the different carbonaceous chondrite groups (CI, CM, CO, CR, CH, CB, CV and CK). We have determined the amino acid abundances of more than 30 primary amino acids in meteorites from each of the eight groups, revealing several interesting trends. There are noticeable differences in the structural diversity and overall abundances of amino acids between meteorites from the different chondrite groups. Because meteorites may have been an important source of amino acids to the prebiotic Earth and these organic compounds are essential for life as we know it, the observed variations of these molecules may have been important for the origins of life.

Tranexamic acid reduces intraoperative occult blood loss and tourniquet time in obese knee osteoarthritis patients undergoing total knee arthroplasty: a prospective cohort study.

PubMed

Meng, Yutong; Li, Zhirui; Gong, Ke; An, Xiao; Dong, Jiyuan; Tang, Peifu

2018-01-01

Obesity can result in increased blood loss, which is correlated with poor prognosis in total knee arthroplasty (TKA). Clinical application of tranexamic acid is effective in reducing blood loss in TKA. However, most previous studies focused on the effect of tranexamic acid in the whole population, neglecting patients with specific health conditions, such as obesity. We hypothesized that tranexamic acid would reduce blood loss to a greater extent in obese patients than in those of normal weight. A total of 304 patients with knee osteoarthritis treated with TKA from October 2013 to March 2015 were separated into tranexamic, non-tranexamic, obese, and non-obese groups. The demographic characteristics, surgical indices, and hematological indices were all recorded. We first investigated the ability of intravenous tranexamic acid to reduce intraoperative blood loss in knee osteoarthritis patients undergoing unilateral TKA. Second, we performed subgroup analysis to compare the effects of tranexamic acid between obese and non-obese patients separately. Of the 304 patients, 146 (52.0%) received tranexamic acid and 130 (42.8%) were obese. In the analysis of the whole group, both the actual and occult blood loss volume were lower in the tranexamic acid group (both P < 0.05). Tourniquet time was shorter in the tranexamic acid group ( P < 0.05). In subgroup analysis, tranexamic acid was shown to reduce theoretical and actual blood loss in both the obese and non-obese groups ( P < 0.05). Tranexamic acid reduced occult blood loss and tourniquet time in the obese group ( P < 0.05), while no such effects were observed in the non-obese group ( P > 0.05). Tranexamic acid can reduce occult blood loss and tourniquet time in obese patients to a greater extent than in patients of normal weight. Therefore, obese knee osteoarthritis patients undergoing TKA can benefit more from tranexamic acid.

Tranexamic acid reduces intraoperative occult blood loss and tourniquet time in obese knee osteoarthritis patients undergoing total knee arthroplasty: a prospective cohort study

PubMed Central

Gong, Ke; An, Xiao; Dong, Jiyuan; Tang, Peifu

2018-01-01

Purpose Obesity can result in increased blood loss, which is correlated with poor prognosis in total knee arthroplasty (TKA). Clinical application of tranexamic acid is effective in reducing blood loss in TKA. However, most previous studies focused on the effect of tranexamic acid in the whole population, neglecting patients with specific health conditions, such as obesity. We hypothesized that tranexamic acid would reduce blood loss to a greater extent in obese patients than in those of normal weight. Patients and methods A total of 304 patients with knee osteoarthritis treated with TKA from October 2013 to March 2015 were separated into tranexamic, non-tranexamic, obese, and non-obese groups. The demographic characteristics, surgical indices, and hematological indices were all recorded. We first investigated the ability of intravenous tranexamic acid to reduce intraoperative blood loss in knee osteoarthritis patients undergoing unilateral TKA. Second, we performed subgroup analysis to compare the effects of tranexamic acid between obese and non-obese patients separately. Results Of the 304 patients, 146 (52.0%) received tranexamic acid and 130 (42.8%) were obese. In the analysis of the whole group, both the actual and occult blood loss volume were lower in the tranexamic acid group (both P < 0.05). Tourniquet time was shorter in the tranexamic acid group (P < 0.05). In subgroup analysis, tranexamic acid was shown to reduce theoretical and actual blood loss in both the obese and non-obese groups (P < 0.05). Tranexamic acid reduced occult blood loss and tourniquet time in the obese group (P < 0.05), while no such effects were observed in the non-obese group (P > 0.05). Conclusion Tranexamic acid can reduce occult blood loss and tourniquet time in obese patients to a greater extent than in patients of normal weight. Therefore, obese knee osteoarthritis patients undergoing TKA can benefit more from tranexamic acid. PMID:29695912

Evaluation of Adsorption Characteristics of a Fibrous Adsorbent Containing Zwitter-Ionic Functional Group, Targeting Organic Acids.

PubMed

Nakazawa, Akira; Tang, Ning; Inoue, Yoshinori; Kamichatani, Waka; Katoh, Toshifumi; Saito, Mitsuru; Obara, Kenji; Toriba, Akira; Hayakawa, Kazuichi

2017-01-01

Diallylamine-maleic acid copolymer (DAM)-nonwoven fabric (DAM-f), a fibrous adsorbent, contains DAM with zwitter-ionic functional groups and forms a hydration layer on the surface. The aim of this report was to evaluate the adsorption selectivity of DAM-f to semi-volatile organic acid (C1-C5). In the aqueous phase, formic acid dissolved in the hydration layer bound to the imino group of DAM-f due to anion exchange interaction. In the gas phase, the adsorption amounts of organic acids increased with the exposure time. Moreover, the adsorption rate constants correlated with the air/water partition coefficients (log K aw ) for formic acid, propionic acid, butyric acid, valeric acid and isovaleric acid, except for acetic acid. These results indicate that DAM-f is highly selective to hydrophilic compounds which easily move from the air to the hydration layer of DAM-f.

Essential fatty acids supplementation in different-stage atopic dogs fed on a controlled diet.

PubMed

Abba, C; Mussa, P P; Vercelli, A; Raviri, G

2005-01-01

The aim of this trial was to evaluate the effects of polyunsaturated fatty acid (PUFA) supplementation in different-stages atopic dogs fed on a controlled diet. Twenty-two non-seasonal atopic dogs of different breeds and ages were included in the 2-month trial. All the patients were given an essential fatty acid (EFA) supplementation [17 mg/kg eicosapentaenoic acid (EPA) + 5 mg/kg docosahexaenoic acid (DHA) + 35 mg/kg gammalinolenic acid (GLA)], the global (diet + supplementation) omega-6 to omega-3 ratio was 5.5-1. Two groups of dogs were considered: group A 'pre-immunotherapy' (15 cases) included dogs with early stages atopy, which had not been submitted to any treatment yet; group B 'post-immunotherapy' (seven cases) included dogs with chronic atopy immunotherapy non-responsive. Clinical evaluations were performed at the beginning, on day 30 and at the end of the trial. Blood serum fatty acids profile was determined at the beginning and at the end of the study. Better clinical results were obtained in group A, a great difference was found between the two groups on pruritus score. Serum arachidonic acid (AA) was significantly lower at the end of the trial in group A while GLA was significantly higher in group B. We hypothesized that different-stages atopic dogs could have different response to EFA supplementation, maybe because of a different fatty acids metabolism. Early stages cases seem to be more responsive to EFA supplementation.

Fish oil, but not soy bean or olive oil enriched infusion decreases histopathological severity of acute pancreatitis in rats without affecting eicosanoid synthesis.

PubMed

Kilian, Maik; Heukamp, Ina; Gregor, Ja Ilja; Schimke, Ingolf; Kristiansen, Glen; Wenger, Frank Axel

2011-12-01

Different dietary fatty acids affect eicosanoid metabolism in different ways, thus influencing the pro- and anti-inflammatory balance of prostaglandins and leukotrienes. Therefore, we analyzed the impact of [n-3], [n-6], and [n-9] fatty acids on eicosanoid metabolism and histopathology in acute pancreatitis in rats. Seventy-five male Sprague-Dawley rats were randomized into five groups (n = 15). Group 1 underwent only laparotomy, while in groups, 2-5 pancreatitis was induced. Groups 1 and 2 were then given saline infusion, groups 3-5 received fat emulsion (group 3: rich in [n-6], group 4: rich in [n-9], group 5: rich in [n-3] fatty acids) for another 18 h. Infusion rich in [n-3] fatty acids significantly decreased histopathological severity of pancreatitis, compared to all other groups. There was no difference concerning the concentrations of prostaglandins and leukotrienes between all groups. Parenteral infusion rich in [n-3] fatty acids reduced histopathological severity of acute pancreatitis in rats without changing eicosanoid metabolism at the endpoint.

Biotransformation of linoleic acid and bile acids by Eubacterium lentum.

PubMed Central

Eyssen, H; Verhulst, A

1984-01-01

Eubacterium lentum is a gram-positive, nonsporeforming, nonmotile, asaccharolytic anaerobe. In the present investigations, 3 E. lentum strains (group E) isolated from rat feces were compared with 30 E. lentum strains (groups A, B, C, and D) previously studied by Macdonald et al. (I. A. Macdonald, J. F. Jellet, D. E. Mahony, and L. V. Holdeman, Appl. Environ. Microbiol. 37:992-1000, 1979). All strains alkalized (pH 8 to 8.5) arginine-containing (2 to 15 mg/ml) culture media, and growth of the majority of the strains was stimulated by arginine. All strains converted linoleic acid into transvaccenic acid by shifting the 12,13-cis double bond of linoleic acid into an 11,12-trans(?) double bond followed by biohydrogenation of the 9,10-cis double bond. Hence, biohydrogenation of linoleic acid is a new general characteristic of E. lentum. The 33 strains were also studied for bile acid deconjugase and hydroxysteroid dehydrogenase (HSDH) activities. The 6 strains in group D were steroid inactive; the 27 strains in groups A, B, C, and E were steroid active. The steroid-active group contained bile acid deconjugase-producing strains (groups C and E, plus strain 116 in group A) and nondeconjugating strains. All nondeconjugating strains of groups A and B developed 7 alpha- and 12 alpha-HSDH activities and contained 3 alpha-HSDH-positive strains and 3 alpha-HSDH-negative strains. Deconjugating strains varied in HSDH activities. PMID:6582800

The effects of the formula of amino acids enriched BCAA on nutritional support in traumatic patients.

PubMed

Wang, Xin-Ying; Li, Ning; Gu, Jun; Li, Wei-Qin; Li, Jie-Shou

2003-03-01

To investigate the formula of amino acid enriched BCAA on nutritional support in traumatic patients after operation. 40 adult patients after moderate or large abdominal operations were enrolled in a prospective, randomly and single-blind-controlled study, and received total parenteral nutrition (TPN) with either formula of amino acid (AA group, 20 cases) or formula of amino acid enriched BCAA (BCAA group, 20 cases). From the second day after operation, total parenteral nutrition was infused to the patients in both groups with equal calorie and equal nitrogen by central or peripheral vein during more than 12 hours per day for 6 days. Meanwhile, nitrogen balance was assayed by collecting 24 hours urine for 6 days. The markers of protein metabolism were investigated such as amino acid patterns, levels of total protein, albumin, prealbumin, transferrin and fibronectin in serum. The positive nitrogen balance in BCAA group occurred two days earlier than that in AA group. The serum levels of total protein and albumin in BCAA group were increased more obviously than that in AA group. The concentration of valine was notably increased and the concentration of arginine was markedly decreased in BCAA group after the formula of amino acids enriched BCAA transfusion. The formula of amino acid enriched BCAA may normalize the levels of serum amino acids, reduce the proteolysis, increase the synthesis of protein, improve the nutritional status of traumatic patients after operation.

Conversion of α-linolenic acid to long-chain omega-3 fatty acid derivatives and alterations of HDL density subfractions and plasma lipids with dietary polyunsaturated fatty acids in Monk parrots (Myiopsitta monachus).

PubMed

Petzinger, C; Larner, C; Heatley, J J; Bailey, C A; MacFarlane, R D; Bauer, J E

2014-04-01

The effect of α-linolenic acid from a flaxseed (FLX)-enriched diet on plasma lipid and fatty acid metabolism and possible atherosclerosis risk factors was studied in Monk parrots (Myiopsitta monachus). Twenty-four Monk parrots were randomly assigned to diets containing either 10% ground SUNs or 10% ground FLXs. Feed intake was calculated daily. Blood samples, body condition scores and body weights were obtained at -5 weeks, day 0, 7, 14, 28, 42 and 70. Plasma samples were analysed for total cholesterol, free cholesterol, triacylglycerols and lipoproteins. Phospholipid subfraction fatty acid profiles were determined. By day 70, the FLX group had significantly higher plasma phospholipid fatty acids including 18:3n-3 (α-linolenic acid), 20:5n-3 (eicosapentaenoic acid) and 22:6n-3 (docosahexaenoic acid). The sunflower group had significantly higher plasma phospholipid levels of 20:4n-6 (arachidonic acid). By day 70, the high-density lipoprotein (HDL) peak shifted resulting in significantly different HDL peak densities between the two experimental groups (1.097 g/ml FLX group and 1.095 g/ml SUN group, p = 0.028). The plasma fatty acid results indicate that Monk parrots can readily convert α-linolenic acid to the long-chain omega-3 derivatives including docosahexaenoic acid and reduce 20:4n-6 accumulation in plasma phospholipids. The reason for a shift in the HDL peak density is unknown at this time. Journal of Animal Physiology and Animal Nutrition © 2013 Blackwell Verlag GmbH.

A New Covalent Inhibitor of Class C β-Lactamases Reveals Extended Active Site Specificity.

PubMed

Tilvawala, Ronak; Cammarata, Michael; Adediran, S A; Brodbelt, Jennifer S; Pratt, R F

2015-12-22

O-Aryloxycarbonyl hydroxamates have previously been shown to efficiently inactivate class C β-lactamases by cross-linking serine and lysine residues in the active site. A new analogue of these inhibitors, D-(R)-O-(phenoxycarbonyl)-N-[(4-amino-4-carboxy-1-butyl)oxycarbonyl]hydroxylamine, designed to inactivate certain low-molecular mass dd-peptidases, has now been synthesized. Although the new molecule was found to be only a poor inactivator of the latter enzymes, it proved, unexpectedly, to be a very effective inactivator (ki = 3.5 × 10(4) M(-1) s(-1)) of class C β-lactamases, more so than the original lead compound, O-phenoxycarbonyl-N-(benzyloxycarbonyl)hydroxylamine. Furthermore, the mechanism of inactivation is different. Mass spectrometry demonstrated that β-lactamase inactivation by the new molecule involved formation of an O-alkoxycarbonylhydroxamate with the nucleophilic active site serine residue. This acyl-enzyme did not cyclize to cross-link the active site as did that from the lead compound. Model building suggested that the rapid enzyme acylation by the new molecule may occur because of favorable interaction between the polar terminus of its side chain and elements of the Ω loop that abuts the active site, Arg 204 in particular. This interaction should be considered in the design of new covalent β-lactamase inhibitors. The initially formed acyl-enzyme partitions (ratio of ∼ 1) between hydrolysis, which regenerates the active enzyme, and formation of an inert second acyl-enzyme. Structural modeling suggests that the latter intermediate arises from conformational movement of the acyl group away from the reaction center, probably enforced by the inflexibility of the acyl group. The new molecule is thus a mechanism-based inhibitor in which an inert complex is formed by noncovalent rearrangement. Phosphyl analogues of the new molecule were efficient inactivators of neither dd-peptidases nor β-lactamases.

Matched cohort study of topical tranexamic acid in cementless primary total hip replacement.

PubMed

Sanz-Reig, Javier; Mas Martinez, Jesus; Verdu Román, Carmen; Morales Santias, Manuel; Martínez Gimenez, Enrique; Bustamante Suarez de Puga, David

2018-03-29

Tranexamic acid has been shown to be effective in reducing blood loss after total hip replacement. The purpose of this study was to prospectively assess the effectiveness of topical TXA use to reduce blood loss after primary total hip replacement and to compare these outcomes with those of a matched control group from a similar cohort that did not have received tranexamic acid. This is a prospective matched control study to assess the effect of a 2 g topical tranexamic acid in 50 mL physiological saline solution in total hip replacement. Primary outcomes were hemoglobin and hematocrit drop, and total blood loss. Secondary outcomes were transfusion rates, length of hospital stay, deep vein thrombosis, and pulmonary embolism events. We could match 100 patients to a control group. There were no statistical significantly differences between the two groups. The hemoglobin and hematocrit postoperative values were significantly higher in topical tranexamic acid group than in control group (P < 0.001). The mean total blood loss was 769 in topical tranexamic acid group and 1163 in control group with significant differences (P = 0.001), which meant 34% reduction in total blood loss. Length of stay was lower in topical tranexamic acid group. The risk of deep vein thrombosis and pulmonary events did not increase. A single dose of 2 g tranexamic acid in 50 mL physiological saline solution topical administration was effective and safe in reducing bleeding in patients undergoing unilateral primary non-cemented total hip replacement compared to a matched control group.

Toothpaste Prevents Debonded Brackets on Erosive Enamel

PubMed Central

Barros, Érico Luiz Damasceno; Pinto, Shelon Cristina Souza; Borges, Alvaro Henrique; Tonetto, Mateus Rodrigues; Ellwood, Roger Phillip; Pretty, Ian; Bandéca, Matheus Coelho

2015-01-01

This study evaluated the effect of high fluoride dentifrice on the bond strength of brackets after erosive challenge. Eighty-four enamel specimens were divided into seven groups (n = 12): WN (distilled water/no acid challenge), W3C (distilled water/3 cycles of acid challenge), and W6C (distilled water/6 cycles of acid challenge) were not submitted to dentifrice treatment. Groups RF3C (regular fluoride dentifrice/3 cycles of acid challenge) and RF6C (regular fluoride dentifrice/6 cycles of acid challenge) were treated with dentifrices containing 1450 μg F−/g and HF3C (high fluoride dentifrice/3 cycles of acid challenge) and HF6C (high fluoride dentifrice/6 cycles of acid challenge) were with 5000 μg F−/g. Acid challenges were performed for seven days. After bond strength test, there was no significant difference among groups submitted to 3 cycles of acid challenge (P > 0.05). Statistically significant difference was found between the regular and high fluoride dentifrices after 6 cycles of acid challenge (<0.05). Similar areas of adhesive remaining were found among control groups and among groups W6C, RF3C, RF6C, HF3C, and HF6C. The high fluoride dentifrice was able to prevent the reduction of bond strength values of brackets submitted to acid challenge. Clinical relevance: the high fluoride toothpaste prevents debonded brackets on erosive enamel. PMID:25879058

The Streptococcus agalactiae Stringent Response Enhances Virulence and Persistence in Human Blood

PubMed Central

Hooven, Thomas A.; Catomeris, Andrew J.; Bonakdar, Maryam; Tallon, Luke J.; Santana-Cruz, Ivette; Ott, Sandra; Daugherty, Sean C.; Tettelin, Hervé

2017-01-01

ABSTRACT Streptococcus agalactiae (group B Streptococcus [GBS]) causes serious infections in neonates. We previously reported a transposon sequencing (Tn-seq) system for performing genomewide assessment of gene fitness in GBS. In order to identify molecular mechanisms required for GBS to transition from a mucosal commensal lifestyle to bloodstream invasion, we performed Tn-seq on GBS strain A909 with human whole blood. Our analysis identified 16 genes conditionally essential for GBS survival in blood, of which 75% were members of the capsular polysaccharide (cps) operon. Among the non-cps genes identified as conditionally essential was relA, which encodes an enzyme whose activity is central to the bacterial stringent response—a conserved adaptation to environmental stress. We used blood coincubation studies of targeted knockout strains to confirm the expected growth defects of GBS deficient in capsule or stringent response activation. Unexpectedly, we found that the relA knockout strains demonstrated decreased expression of β-hemolysin/cytolysin, an important cytotoxin implicated in facilitating GBS invasion. Furthermore, chemical activation of the stringent response with serine hydroxamate increased β-hemolysin/cytolysin expression. To establish a mechanism by which the stringent response leads to increased cytotoxicity, we performed transcriptome sequencing (RNA-seq) on two GBS strains grown under stringent response or control conditions. This revealed a conserved decrease in the expression of genes in the arginine deiminase pathway during stringent response activation. Through coincubation with supplemental arginine and the arginine antagonist canavanine, we show that arginine availability is a determinant of GBS cytotoxicity and that the pathway between stringent response activation and increased virulence is arginine dependent. PMID:29109175

Role of Omega-3 Fatty Acids on Lipid Profile in Diabetic Dyslipidaemia: Single Blind, Randomised Clinical Trial.

PubMed

Chauhan, Shaylika; Kodali, Hanish; Noor, Jawad; Ramteke, Karuna; Gawai, Vidisha

2017-03-01

Diabetic dyslipidaemia is characterised by hypertriglyceridaemia, low High Density Lipoprotein (HDL), postprandial lipimea, small and dense LDL particles is considered to be a major predisposing factor for various macrovascular complications. Omega-3 fatty acids are fish oil derivative introduced in the market for dyslipidaemia associated with increased triglyceride level. To study the effect of omega-3 fatty acids on lipid profile in Type II diabetes patients. This study was prospective, single blind, randomized comparative trial. Hundred patients were randomized into three groups. Group I received metformin 500 mg twice daily and placebo, Group II received metformin 500 mg twice daily and omega-3 fatty acids (1 gram) once daily and the Group III received metformin 500 mg twice daily and omega-3 fatty acids (1 gram) twice daily. ANOVA test was applied for analysis. Group II was effective in reducing the triglyceride level from 144.59±14.18 mg/dl to 101±13.31 mg/dl which was significant as compared to Group I from 147.67±18.57 mg/dl to 145.8±19.86 mg/dl respectively. Group III containing 1 g of omega-3 fatty acids twice daily showed decrease from 144.83±22.17 mg/dl to 86±17.46 mg/dl and was more effective in reducing triglyceride levels than Group II containing 1 gram of omega-3 fatty acids once daily. Omega-3 fatty acids can be given in conjunction with metformin to reduce triglyceride levels in diabetic dyslipidaemia without any adverse drug reactions or any drug interaction. Omega-3 fatty acids were effective in reducing the triglyceride level significantly as compared to placebo. Two grams of omega-3 fatty acids were more effective than 1 gram of omega-3 fatty acids in reducing triglyceride levels.

Tranexamic Acid in Patients Undergoing Coronary-Artery Surgery.

PubMed

Myles, Paul S; Smith, Julian A; Forbes, Andrew; Silbert, Brendan; Jayarajah, Mohandas; Painter, Thomas; Cooper, D James; Marasco, Silvana; McNeil, John; Bussières, Jean S; McGuinness, Shay; Byrne, Kelly; Chan, Matthew T V; Landoni, Giovanni; Wallace, Sophie

2017-01-12

Tranexamic acid reduces the risk of bleeding among patients undergoing cardiac surgery, but it is unclear whether this leads to improved outcomes. Furthermore, there are concerns that tranexamic acid may have prothrombotic and proconvulsant effects. In a trial with a 2-by-2 factorial design, we randomly assigned patients who were scheduled to undergo coronary-artery surgery and were at risk for perioperative complications to receive aspirin or placebo and tranexamic acid or placebo. The results of the tranexamic acid comparison are reported here. The primary outcome was a composite of death and thrombotic complications (nonfatal myocardial infarction, stroke, pulmonary embolism, renal failure, or bowel infarction) within 30 days after surgery. Of the 4662 patients who were enrolled and provided consent, 4631 underwent surgery and had available outcomes data; 2311 were assigned to the tranexamic acid group and 2320 to the placebo group. A primary outcome event occurred in 386 patients (16.7%) in the tranexamic acid group and in 420 patients (18.1%) in the placebo group (relative risk, 0.92; 95% confidence interval, 0.81 to 1.05; P=0.22). The total number of units of blood products that were transfused during hospitalization was 4331 in the tranexamic acid group and 7994 in the placebo group (P<0.001). Major hemorrhage or cardiac tamponade leading to reoperation occurred in 1.4% of the patients in the tranexamic acid group and in 2.8% of the patients in the placebo group (P=0.001), and seizures occurred in 0.7% and 0.1%, respectively (P=0.002 by Fisher's exact test). Among patients undergoing coronary-artery surgery, tranexamic acid was associated with a lower risk of bleeding than was placebo, without a higher risk of death or thrombotic complications within 30 days after surgery. Tranexamic acid was associated with a higher risk of postoperative seizures. (Funded by the Australian National Health and Medical Research Council and others; ATACAS Australia New Zealand Clinical Trials Registry number, ACTRN12605000557639 .).

Neuroprotective effect of p-coumaric acid in rat model of embolic cerebral ischemia

PubMed Central

Guven, Mustafa; Aras, Adem Bozkurt; Akman, Tarik; Sen, Halil Murat; Ozkan, Adile; Salis, Osman; Sehitoglu, Ibrahim; Kalkan, Yildiray; Silan, Coskun; Deniz, Mustafa; Cosar, Murat

2015-01-01

Objective(s): Stroke poses a crucial risk for mortality and morbidity. Our study aimed to investigate the effect of p-coumaric acid on focal cerebral ischemia in rats. Material and Methods: Rats were randomly divided into four groups, namely Group I (control rats), Group II (ischemia rats), Group III (6 hr ischemia + p-coumaric acid rats) and Group IV (24 hr ischemia + p-coumaric acid rats). Cerebral ischemia was induced via intraluminal monofilament occlusion model. In all groups, the brain was removed after the procedure and rats were sacrificed. Malondialdehyde, superoxide dismutase and nuclear respiratory factor-1 were measured in the ischemic hemisphere. The histopathological changes were observed in the right hemisphere within the samples. Functional assessment was performed for neurological deficit scores. Results: Following the treatment, biochemical factors changed significantly. Histopathologically, it was shown that p-coumaric acid decreased the oxidative damage. The neurological deficit scores of p-coumaric acid-treated rats were significantly improved after cerebral ischemia. Conclusion: Our results showed that p-coumaric acid is a neuroprotective agent on account of its strong anti-oxidant and anti-apoptotic features. Moreover, p-coumaric acid decreased the focal ischemia. Extra effort should be made to introduce p-coumaric acid as a promising therapeutic agent to be utilized for treatment of human cerebral ischemia in the future. PMID:26019798

A randomized controlled experimental study of the efficacy of platelet-rich plasma and hyaluronic acid for the prevention of adhesion formation in a rat uterine horn model.

PubMed

Oz, Murat; Cetinkaya, Nilufer; Bas, Sevda; Korkmaz, Elmas; Ozgu, Emre; Terzioglu, Gokay Serdar; Buyukkagnici, Umran; Akbay, Serap; Caydere, Muzaffer; Gungor, Tayfun

2016-09-01

Platelet-rich plasma (PRP) has been known to possess an efficacy in tissue regeneration. The aim of this study was to determine the role of PRP on post-operative adhesion formation in an experimental rat study. Thirty Sprague-Dawley rats were randomly divided into control, hyaluronic acid, and PRP treatment groups and operated on for uterine horn adhesion modeling. Blood was collected to produce a PRP with platelet counts of 688 × 10(3)/μL, and 1 ml of either hyaluronic acid gel or PRP was administered over the standard lesions, while the control group received no medication. The evaluation of post-operative adhesions was done on the 30th post-operative day. The location, extent, type, and tenacity of adhesions as well as total adhesion scores, tissue inflammation, fibrosis and transforming growth factor-1beta (TGF-1β) expressions were evaluated. The total adhesion score was significantly lower in the PRP group (3.2 ± 1.5) compared with the hyaluronic acid (5.0 ± 1.3) and control (8.1 ± 1.7) groups. The extent of the adhesions was significantly lower in the PRP group. There was no significant difference in the type and tenacity of adhesions between the hyaluronic acid and the PRP group. The level of inflammation was significantly higher in the control group than the others, while there was no difference between the PRP and hyaluronic acid groups. TGF-1β expression was significantly lesser in the PRP group than the control and hyaluronic acid groups. PRP is more effective than hyaluronic acid treatment in preventing post-operative adhesion formation in an experimental rat uterine horn adhesion model.

Chemoprevention of esophageal adenocarcinoma in a rat model by ursodeoxycholic acid.

PubMed

Ojima, Eisuke; Fujimura, Takashi; Oyama, Katsunobu; Tsukada, Tomoya; Kinoshita, Jun; Miyashita, Tomoharu; Tajima, Hidehiro; Fushida, Sachio; Harada, Shin-ichi; Mukaisho, Ken-ichi; Hattori, Takanori; Ohta, Tetsuo

2015-08-01

Reflux of bile acid into the esophagus induces esophagitis, inflammation-stimulated hyperplasia, metaplasia such as Barrett's esophagus (BE), and esophageal adenocarcinoma (EAC). Caudal-type homeobox 2 (Cdx2) via nuclear factor (NF)-κB induced by bile acid is an important factor in the development of BE and EAC. In colorectal cancer, experimental data suggest a chemopreventive effect of ursodeoxycholic acid (UDCA). We hypothesized that UDCA may protect against the esophageal inflammation-metaplasia-carcinoma sequence by decreasing the overall proportion of the toxic bile acids. Wistar male rats that underwent a duodenoesophageal reflux procedure were divided into two groups. One group was given commercial chow (control group), and the other was given experimental chow containing UDCA (UDCA group). The animals were killed at 40 weeks after surgery, and their bile and esophagus were examined. In the UDCA group, the esophagitis was milder and the incidence of BE was significantly lower (p < 0.05) than in the control group, and EAC was not observed (p < 0.05). In analysis of the compartment of bile acid, UDCA was markedly increased in the UDCA group compared with the control group (32.7 ± 11.4 vs. 0.82 ± 0.33 mmol/L, p < 0.05) and cholic acid was decreased (32.7 ± 4.05 vs. 60.9 ± 8.26 mmol/L, p < 0.05). Expression intensity of Cdx2 and NF-κB was greater in the control group than in the UDCA group (p < 0.05). UDCA may be a chemopreventive agent against EAC by varying the bile acid composition.

Metabolomics Profiles of Hepatocellular Carcinoma in a Korean Prospective Cohort: The Korean Cancer Prevention Study-II.

PubMed

Jee, Sun Ha; Kim, Minjoo; Kim, Minkyung; Yoo, Hye Jin; Kim, Hyungyoon; Jung, Keum Ji; Hong, Seri; Lee, Jong Ho

2018-05-01

In the prospective Korean Cancer Prevention Study-II (KCPS-II), we investigated the application of metabolomics to differentiate subjects with incident hepatocellular carcinoma (HCC group) from subjects who remained free of cancer (control group) during a mean follow-up period of 7 years with the aim of identifying valuable metabolic biomarkers for HCC. We used baseline serum samples from 75 subjects with incident HCC and 134 age- and gender-matched cancer-free subjects. Serum metabolic profiles associated with HCC incidence were investigated via metabolomics analysis. Compared with the control group, the HCC group showed significantly higher serum levels of aspartate aminotransferase (AST), alanine aminotransferase, and γ-glutamyl transpeptidase. At baseline, compared with the control group, the HCC group showed significantly higher levels of 9 metabolites, including leucine, 5-hydroxyhexanoic acid, phenylalanine, tyrosine, arachidonic acid, and tauroursodeoxycholic acid (TUDCA), but lower levels of 28 metabolites, including oleamide, androsterone sulfate, L-palmitoylcarnitine, lysophosphatidic acid (LPA) 16:0, LPA 18:1, and lysophosphatidylcholines (lysoPC). Multiple linear regression revealed that the incidence of HCC was associated with the levels of tyrosine, AST, lysoPCs (16:1, 20:3), oleamide, 5-hydroxyhexanoic acid, androsterone sulfate, and TUDCA (adjusted R 2 = 0.514, P = 0.036). This study showed the clinical relevance of the dysregulation of not only branched amino acids, aromatic amino acids, and lysoPCs but also bile acid biosynthesis and linoleic acid, arachidonic acid, and fatty acid metabolism. In addition, tyrosine, AST, lysoPCs (16:1, 20:3), oleamide, 5-hydroxyhexanoic acid, androsterone sulfate, and TUDCA were identified as independent variables associated with the incidence of HCC. Cancer Prev Res; 11(5); 303-12. ©2018 AACR . ©2018 American Association for Cancer Research.

Serum Uric Acid Level as a Prognostic Marker in Patients With Acute Respiratory Distress Syndrome.

PubMed

Lee, Hyun Woo; Choi, Sun Mi; Lee, Jinwoo; Park, Young Sik; Lee, Chang-Hoon; Yim, Jae-Joon; Yoo, Chul-Gyu; Kim, Young Whan; Han, Sung Koo; Lee, Sang-Min

2017-01-01

Uric acid acts as both a pathogenic inflammatory mediator and an antioxidative agent. Several studies have shown that uric acid level correlates with the incidence, severity, and prognosis of pulmonary diseases. However, the association between uric acid level and acute respiratory distress syndrome (ARDS) has not been studied. This study was conducted to elucidate how serum uric acid level is related with clinical prognosis of ARDS. A retrospective cohort study with propensity score matching was conducted at a medical intensive care unit of a tertiary teaching hospital. The medical records of patients diagnosed with ARDS admitted from 2005 through 2011 were reviewed. Two hundred thirty-seven patients with ARDS met the inclusion criteria. Patients with a serum uric acid level <3.0 mg/dL were classified into the low uric acid group, and those with a level ≥3 mg/dL were classified into the normal to high uric acid group. We selected 40 patients in each group using propensity score matching. A higher percentage of patients in the low uric acid group experienced clinical improvement in ARDS. More patients died from sepsis in the normal to high uric acid group. Kaplan-Meier analysis showed that a low serum uric acid level was significantly associated with better survival rate. In patients with ARDS, a low serum uric acid level may be a prognostic marker of a low risk of in-hospital mortality.

Contrasting plasma free amino acid patterns in elite athletes: association with fatigue and infection

PubMed Central

Kingsbury, K. J.; Kay, L.; Hjelm, M.

1998-01-01

AIM: There is little information on the plasma free amino acid patterns of elite athletes against which fatigue and nutrition can be considered. Therefore the aim was to include analysis of this pattern in the medical screening of elite athletes during both especially intense and light training periods. METHODS: Plasma amino acid analysis was undertaken in three situations. (1) A medical screening service was offered to elite athletes during an intense training period before the 1992 Olympics. Screening included a blood haematological/biochemical profile and a microbial screen in athletes who presented with infection. The athletes were divided into three groups who differed in training fatigue and were considered separately. Group A (21 track and field athletes) had no lasting fatigue; group B (12 judo competitors) reported heavy fatigue at night but recovered overnight to continue training; group C (18 track and field athletes, one rower) had chronic fatigue and had been unable to train normally for at least several weeks. (2) Athletes from each group were further screened during a post- Olympic light training period. (3) Athletes who still had low amino acid levels during the light training period were reanalysed after three weeks of additional protein intake. RESULTS: (1) The pre-Olympics amino acid patterns were as follows. Group A had a normal amino acid pattern (glutamine 554 (25.2) micromol/l, histidine 79 (6.1) micromol/l, total amino acids 2839 (92.1) micromol/l); all results are means (SEM). By comparison, both groups B and C had decreased plasma glutamine (average 33%; p<0.001) with, especially in group B, decreased histidine, glucogenic, ketogenic, and branched chain amino acids (p<0.05 to p<0.001). None in group A, one in group B, but ten athletes in group C presented with infection: all 11 athletes had plasma glutamine levels of less than 450 micromol/l. No intergroup differences in haematological or other blood biochemical parameters, apart from a lower plasma creatine kinase activity in group C than in group B (p<0.05) and a low neutrophil to lymphocyte ratio in the athletes with viral infections (1.2 (0.17)), were found. (2) During post-Olympic light training, group A showed no significant amino acid changes. In contrast, group B recovered normal amino acid levels (glutamine 528 (41.4) micromol/l, histidine 76 (5.3) micromol/l, and total amino acids 2772 (165) micromol/l) (p<0.05 to p<0.001) to give a pattern comparable with that of group A, whereas, in group C, valine and threonine had increased (p<0.05), but glutamine (441 (24.5) micromol/l) and histidine (58 (5.3) micromol/l) remained low. Thus none in group A, two in group B, but ten (53%) in group C still had plasma glutamine levels below 450 micromol/l, including eight of the 11 athletes who had presented with infection. (3) With the additional protein intake, virtually all persisting low glutamine levels increased to above 500 micromol/l. Plasma glutamine rose to 592 (35.1) micromol/l and histidine to 86 (6.0) micromol/l. Total amino acids increased to 2761 (128) micromol/l (p<0.05 to p<0.001) and the amino acid pattern normalised. Six of the ten athletes on this protein intake returned to increased training within the three weeks. CONCLUSION: Analysis of these results provided contrasting plasma amino acid patterns: (a) a normal pattern in those without lasting fatigue; (b) marked but temporary changes in those with acute fatigue; (c) a persistent decrease in plasma amino acids, mainly glutamine, in those with chronic fatigue and infection, for which an inadequate protein intake appeared to be a factor. 


 PMID:9562160

Comparative studies on the interaction of caffeic acid, chlorogenic acid and ferulic acid with bovine serum albumin

NASA Astrophysics Data System (ADS)

Li, Shuang; Huang, Kelong; Zhong, Ming; Guo, Jun; Wang, Wei-zheng; Zhu, Ronghua

2010-10-01

The substitution of the hydrogen on aromatic and esterification of carboxyl group of the phenol compounds plays an important role in their bio-activities. In this paper, caffeic acid (CaA), chlorogenic acid (ChA) and ferulic acid (FA) were selected to investigate the binding to bovine serum albumin (BSA) using UV absorption spectroscopy, fluorescence spectroscopy and synchronous fluorescence spectroscopy. It was found that the methoxyl group substituting for the 3-hydroxyl group of CaA decreased the affinity for BSA and the esterification of carboxyl group of CaA with quinic acid increased the affinities. The affinities of ChA and FA with BSA were more sensitive to the temperature than that of CaA with BSA. Synchronous fluorescence spectroscopy and time-resolved fluorescence indicated that the Stern-Volmer plots largely deviated from linearity at high concentrations and were caused by complete quenching of the tyrosine fluorescence of BSA.

Molecular design and synthesis of functional photothermopolymers from hydroxyl benzoic acids

NASA Astrophysics Data System (ADS)

Tong, Xiao; Gu, Jiangnan; Wang, Liyuan; Zou, Yingquan; Yu, Shangxian

2000-06-01

The most applicable hydroxyl benzoic acid monomers were optimized to synthesize the thermolysis-decarboxylation polymers according to the relative results of TG analysis of hydroxyl benzoic acids, their 13C-NMR spectra analyses and their quantum chemistry calculation with AB-INITIO method. On the basis of the empirical rule -- M/A value rule, while phenols with high M/A value and hydroxyl benzoic acids were both cocondensed with formaldehyde at proper ratio, the novolak resin with carboxyl groups used as a thermal imaging material could be obtained. In the presence of an acid catalyst, such as oxalic acid, a hydroxyl benzoic acid could be additionally polymerized with divinyl benzene (DVB) to synthesize another kind of polymer with not only carboxyl groups but also phenolic hydroxyl groups. The thermal imaging mechanisms of these polymers with carboxyl groups were discussed in the paper.

Superhard Transparent Coatings

DTIC Science & Technology

1975-04-01

alcohol has OH groups and polymethacrylic acid has carboxyl COOH groups. These form a clear suspension with the sub- micron hydrophilic particles...PHOSPHORIC ACID /SILICA/PVA 38 SYSTEM 3: ALON/POLYSILICIC ACID /BORACIC ACID 38 SYSTEM 4: ALON/SILICA/CYMEL - MOH HARDNESS VS...60 POLYSILICIC ACID 60 Methods for the Preparation of a Polystllcate/ Alon Suspension 61 Compositions 62 STRETCHED PLEX 63 OPTIMUM COMPOSITIONS

Propofol exposure during early gestation impairs learning and memory in rat offspring by inhibiting the acetylation of histone.

PubMed

Lin, Jiamei; Wang, Shengqiang; Feng, Yunlin; Zhao, Weihong; Zhao, Weilu; Luo, Foquan; Feng, Namin

2018-05-01

Propofol is widely used in clinical practice, including non-obstetric surgery in pregnant women. Previously, we found that propofol anaesthesia in maternal rats during the third trimester (E18) caused learning and memory impairment to the offspring rats, but how about the exposure during early pregnancy and the underlying mechanisms? Histone acetylation plays an important role in synaptic plasticity. In this study, propofol was administered to the pregnant rats in the early pregnancy (E7). The learning and memory function of the offspring were tested by Morris water maze (MWM) test on post-natal day 30. Two hours before each MWM trial, histone deacetylase 2 (HDAC2) inhibitor, suberoylanilide hydroxamic acid (SAHA), Senegenin (SEN, traditional Chinese medicine), hippyragranin (HGN) antisense oligonucleotide (HGNA) or vehicle were given to the offspring. The protein levels of HDAC2, acetylated histone 3 (H3) and 4 (H4), cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB), N-methyl-D-aspartate receptor (NMDAR) 2 subunit B (NR2B), HGN and synaptophysin in offspring's hippocampus were determined by Western blot or immunofluorescence test. It was discovered that infusion with propofol in maternal rats on E7 leads to impairment of learning and memory in offspring, increased the protein levels of HDAC2 and HGN, decreased the levels of acetylated H3 and H4 and phosphorylated CREB, NR2B and synaptophysin. HDAC2 inhibitor SAHA, Senegenin or HGN antisense oligonucleotide reversed all the changes. Thus, present results indicate exposure to propofol during the early gestation impairs offspring's learning and memory via inhibiting histone acetylation. SAHA, Senegenin and HGN antisense oligonucleotide might have therapeutic value for the adverse effect of propofol. © 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Two-dimensional parallel array technology as a new approach to automated combinatorial solid-phase organic synthesis

PubMed

Brennan; Biddison; Frauendorf; Schwarcz; Keen; Ecker; Davis; Tinder; Swayze

1998-01-01

An automated, 96-well parallel array synthesizer for solid-phase organic synthesis has been designed and constructed. The instrument employs a unique reagent array delivery format, in which each reagent utilized has a dedicated plumbing system. An inert atmosphere is maintained during all phases of a synthesis, and temperature can be controlled via a thermal transfer plate which holds the injection molded reaction block. The reaction plate assembly slides in the X-axis direction, while eight nozzle blocks holding the reagent lines slide in the Y-axis direction, allowing for the extremely rapid delivery of any of 64 reagents to 96 wells. In addition, there are six banks of fixed nozzle blocks, which deliver the same reagent or solvent to eight wells at once, for a total of 72 possible reagents. The instrument is controlled by software which allows the straightforward programming of the synthesis of a larger number of compounds. This is accomplished by supplying a general synthetic procedure in the form of a command file, which calls upon certain reagents to be added to specific wells via lookup in a sequence file. The bottle position, flow rate, and concentration of each reagent is stored in a separate reagent table file. To demonstrate the utility of the parallel array synthesizer, a small combinatorial library of hydroxamic acids was prepared in high throughput mode for biological screening. Approximately 1300 compounds were prepared on a 10 μmole scale (3-5 mg) in a few weeks. The resulting crude compounds were generally >80% pure, and were utilized directly for high throughput screening in antibacterial assays. Several active wells were found, and the activity was verified by solution-phase synthesis of analytically pure material, indicating that the system described herein is an efficient means for the parallel synthesis of compounds for lead discovery. Copyright 1998 John Wiley & Sons, Inc.

Synergistic anticancer effects of cisplatin and histone deacetylase inhibitors (SAHA and TSA) on cholangiocarcinoma cell lines.

PubMed

Asgar, Md Ali; Senawong, Gulsiri; Sripa, Banchob; Senawong, Thanaset

2016-01-01

Clinical application of cisplatin against cholangiocarcinoma is often associated with resistance and toxicity posing urgent demand for combination therapy. In this study, we evaluated the combined anticancer effect of cisplatin and histone deacetylase inhibitors (HDACIs), suberoylanilide hydroxamic acid (SAHA) and trichostatin A (TSA), on the cholangiocarcinoma KKU-100 and KKU-M214 cell lines. Antiproliferative activity was evaluated using MTT assay. Apoptosis induction and cell cycle arrest were analyzed by flow cytometry. Cell cycle and apoptosis regulating proteins were evaluated by western blot analysis. MTT assay showed that cisplatin, SAHA and TSA dose-dependently reduced the viability of KKU-100 and KKU-M214 cells. The combination of cisplatin and HDACIs exerted significantly more cytotoxicity than the single drugs. Combination indices below 1.0 reflect synergism between cisplatin and HDACIs, leading to positive dose reductions of cisplatin and HDACIs. Cisplatin and HDACIs alone induced G0/G1 phase arrest in KKU-100 cells, but the drug combinations increased sub-G1 percent more than either drug. However, cisplatin and HDACIs alone or in combination increased only the sub-G1 percent in KKU-M214 cells. Annexin V-FITC staining revealed that cisplatin and HDACIs combinations induced more apoptotic cell death of both KKU-100 and KKU-M214 cells than the single drug. In KKU-100 cells, growth inhibition was accompanied by upregulation of p53 and p21 and downregulation of CDK4 and Bcl-2 due to exposure to cisplatin, SAHA and TSA alone or in combination. Moreover, combination of agents exerted higher impacts on protein expression. Single agents or combination did not affect p53 expression, however, combination of cisplatin and HDACIs increased the expression of p21 in KKU-M214 cells. Taken together, cisplatin and HDACIs combination may improve the therapeutic outcome in cholangiocarcinoma patients.

TSA increases C/EBP‑α expression by increasing its lysine acetylation in hepatic stellate cells.

PubMed

Tao, Li-Li; Ding, Di; Yin, Wei-Hua; Peng, Ji-Ying; Hou, Chen-Jian; Liu, Xiu-Ping; Chen, Yao-Li

2017-11-01

CCAAT enhancer binding protein‑α (C/EBP‑α) is a transcription factor expressed only in certain tissues, including the liver. It has been previously demonstrated that C/EBP‑α may induce apoptosis in hepatic stellate cells (HSCs), raising the question of whether acetylation of C/EBP‑α is associated with HSCs, and the potential associated mechanism. A total of three histone deacetylase inhibitors (HDACIs), including trichostatin A (TSA), suberoylanilide hydroxamic acid and nicotinamide, were selected to determine whether acetylation affects C/EBP‑α expression. A Cell Counting Kit‑8 assay was used to determine the rate of proliferation inhibition following treatment with varying doses of the three HDACIs in HSC‑T6 and BRL‑3A cells. Western blot analysis was used to examine Caspase‑3, ‑8, ‑9, and ‑12 levels in HSC‑T6 cells treated with adenoviral‑C/EBP‑α and/or TSA. Following treatment with TSA, a combination of reverse transcription‑quantitative polymerase chain reaction and western blot analyses was used to determine the inherent C/EBP‑α mRNA and protein levels in HSC‑T6 cells at 0, 1, 2, 4, 8, 12, 24, 36 and 48 h. Nuclear and cytoplasmic proteins were extracted to examine C/EBP‑α distribution. Co‑immunoprecipitation analysis was used to examine the lysine acetylation of C/EBP‑α. It was observed that TSA inhibited the proliferation of HSC‑T6 cells to a greater extent compared with BRL‑3A cells, following treatment with the three HDACIs. TSA induced apoptosis in HSC‑T6 cells and enhanced the expression of C/EBP‑α. Following treatment of HSC‑T6 cells with TSA, inherent C/EBP‑α expression increased in a time‑dependent manner, and its lysine acetylation simultaneously increased. Therefore, the results of the present study suggested that TSA may increase C/EBP‑α expression by increasing its lysine acetylation in HSCs.

The Therapeutic Potential of AN-7, a Novel Histone Deacetylase Inhibitor, for Treatment of Mycosis Fungoides/Sezary Syndrome Alone or with Doxorubicin

PubMed Central

Goldfeiz, Neta; Rephaeli, Ada; Nudelman, Abraham; Weitman, Michal; Tarasenko, Nataly; Gorovitz, Batia; Maron, Leah; Yehezkel, Shiran; Amitay-Laish, Iris; Lubin, Ido; Hodak, Emmilia

2016-01-01

The 2 histone deacetylase inhibitors (HDACIs) approved for the treatment of cutaneous T-cell lymphoma (CTCL) including mycosis fungoides/sezary syndrome (MF/SS), suberoylanilide hydroxamic acid (SAHA) and romidepsin, are associated with low rates of overall response and high rates of adverse effects. Data regarding combination treatments with HDACIs is sparse. Butyroyloxymethyl diethylphosphate (AN-7) is a novel HDACI, which was found to have selective anticancer activity in several cell lines and animal models. The aim of this study was to compare the anticancer effects of AN-7 and SAHA, either alone or combined with doxorubicin, on MF/SS cell lines and peripheral blood lymphocytes (PBL) from patients with Sezary syndrome (SPBL). MyLa cells, Hut78 cells, SPBL, and PBL from healthy normal individuals (NPBL) were exposed to the test drugs, and the findings were analyzed by a viability assay, an apoptosis assay, and Western blot. AN-7 was more selectively toxic to MyLa cells, Hut78 cells, and SPBL (relative to NPBL) than SAHA and also acted more rapidly. Both drugs induced apoptosis in MF/SS cell lines, SAHA had a greater effect on MyLa cell line, while AN-7 induced greater apoptosis in SPBL; both caused an accumulation of acetylated histone H3, but AN-7 was associated with earlier kinetics; and both caused a downregulation of the HDAC1 protein in MF/SS cell lines. AN-7 acted synergistically with doxorubicin in both MF/SS cell lines and SPBL, and antagonistically with doxorubicin in NPBL. By contrast, SAHA acted antagonistically with doxorubicin on MF/SS cell lines, SPBL, and NPBL, leaving <50% viable cells. In conclusion, AN-7 holds promise as a therapeutic agent in MF/SS and has several advantages over SAHA. Our data provide a rationale for combining AN-7, but not SAHA, with doxorubicin to induce the cell death in MF/SS. PMID:26752418

The Therapeutic Potential of AN-7, a Novel Histone Deacetylase Inhibitor, for Treatment of Mycosis Fungoides/Sezary Syndrome Alone or with Doxorubicin.

PubMed

Moyal, Lilach; Feldbaum, Nataly; Goldfeiz, Neta; Rephaeli, Ada; Nudelman, Abraham; Weitman, Michal; Tarasenko, Nataly; Gorovitz, Batia; Maron, Leah; Yehezkel, Shiran; Amitay-Laish, Iris; Lubin, Ido; Hodak, Emmilia

2016-01-01

The 2 histone deacetylase inhibitors (HDACIs) approved for the treatment of cutaneous T-cell lymphoma (CTCL) including mycosis fungoides/sezary syndrome (MF/SS), suberoylanilide hydroxamic acid (SAHA) and romidepsin, are associated with low rates of overall response and high rates of adverse effects. Data regarding combination treatments with HDACIs is sparse. Butyroyloxymethyl diethylphosphate (AN-7) is a novel HDACI, which was found to have selective anticancer activity in several cell lines and animal models. The aim of this study was to compare the anticancer effects of AN-7 and SAHA, either alone or combined with doxorubicin, on MF/SS cell lines and peripheral blood lymphocytes (PBL) from patients with Sezary syndrome (SPBL). MyLa cells, Hut78 cells, SPBL, and PBL from healthy normal individuals (NPBL) were exposed to the test drugs, and the findings were analyzed by a viability assay, an apoptosis assay, and Western blot. AN-7 was more selectively toxic to MyLa cells, Hut78 cells, and SPBL (relative to NPBL) than SAHA and also acted more rapidly. Both drugs induced apoptosis in MF/SS cell lines, SAHA had a greater effect on MyLa cell line, while AN-7 induced greater apoptosis in SPBL; both caused an accumulation of acetylated histone H3, but AN-7 was associated with earlier kinetics; and both caused a downregulation of the HDAC1 protein in MF/SS cell lines. AN-7 acted synergistically with doxorubicin in both MF/SS cell lines and SPBL, and antagonistically with doxorubicin in NPBL. By contrast, SAHA acted antagonistically with doxorubicin on MF/SS cell lines, SPBL, and NPBL, leaving <50% viable cells. In conclusion, AN-7 holds promise as a therapeutic agent in MF/SS and has several advantages over SAHA. Our data provide a rationale for combining AN-7, but not SAHA, with doxorubicin to induce the cell death in MF/SS.

Oleic Acid Protects Against Oxidative Stress Exacerbated by Cytarabine and Doxorubicin in Rat Brain.

PubMed

Guzmán, David Calderón; Brizuela, Norma Osnaya; Herrera, Maribel Ortíz; Olguín, Hugo Juárez; García, Ernestina Hernández; Peraza, Armando Valenzuela; Mejía, Gerardo Barragán

2016-01-01

The objective of this study was to analyze the effect of doxorubicin and cytarabine on biogenic amines and oxidative biomarkers in the brain of rats treated with oleic acid. Thirty-six Wistar rats distributed in 6 groups, were treated as follows: group 1 (control), NaCl 0.9%; group 2 doxorubicin (1mg/kg); group 3 cytarabine (70mg /kg); group 4 oleic acid (1500μl/kg); group 5 doxorubicin + oleic acid; group 6 cytarabine + oleic acid. All compounds were administered intraperitoneally for 5 days. The Rats were sacrificed after receiving the last administration and their brains were dissected in cortex, hemispheres, and cerebellum/medulla oblongata. Blood samples were obtained on sacrifice to assess the levels of glucose and triglycerides. In each brain region, lipoperoxidation (TBARS), H2O2, Na+, K+ ATPase, glutathione (GSH), serotonin metabolites (5-HIAA) and dopamine were measured using validated methods. Cytarabine decreased the levels of dopamine, TBARS, GSH, H2O2 and ATPase in all regions. Doxorubicin combined with oleic acid increased the levels of GSH in cortex, and decreased ATPase in cerebellum/medulla oblongata. These results suggest that the reduction of dopamine and oxidant effect during cytarabine treatment could result in brain injury but could be prevented by oleic acid supplementation.

[Comparison of single-indicator thermodilution versus gravimetric measurement in determination of extra-vascular lung water in dogs with acute respiratory distress syndrome].

PubMed

Shen, Ju-fang; Qiu, Hai-bo; Yang, Yi; Liu, Song-qiao; Chen, Yong-ming; Li, Jia-qiong; Wu, Bin; Ding, Hui-min

2006-06-01

To compare the measurement of extra-vascular lung water (EVLW) by a single-indicator dilution technique and measurement obtained by gravimetry in different types of acute respiratory distress syndrome (ARDS). Thirty-three dogs were randomly assigned to three groups: control group, oleic acid group and hydrochloric acid group. ARDS was reproduced by either intravenous injection of oleic acid or intratracheal instillation of hydrochloric acid. EVLW was measured before ARDS, at the onset of ARDS and 10 hours after ARDS by a single indicator dilution technique. Ten hours after ARDS, dogs were sacrificed and then EVLW was quantitated by a gravimetric measurement (golden standard). Hemodynamics and pulmonary gas exchange were determined. There was a close positive correlation (r=0.8820, P<0.05) between single indicator dilution and gravimetric measurements. However, the measurement with the single indicator dilution was consistently higher than the gravimetric measurement. In the control group, there was a positive correlation (r=0.9870, P<0.05) between the values of EVLW as measured by single indicator dilution and by gravimetric measurements. In the oleic acid group, there was also a significant correlation (r=0.9360, P<0.05) between the values of EVLW as measured by single indicator dilution and by gravimetric measurements. In the hydrochloric acid group, correlation (r=0.7950, P<0.05) was also found between EVLW as measured by the two methods. However, the correlation found was lower in the hydrochloric acid group than those in other two groups. Hydrochloric acid instillation resulted in a significant increase in shunting and the partial pressure of carbon dioxide in artery (PaCO(2)) compared with oleic acid group at 10 hours after ARDS. The results of measuring EVLW using single indicator dilution measurement are closely related with those of gravimetric measurement in ARDS, however, the correlations varies with the methods of reproduction of ARDS.

Uric Acid Level Has a U-shaped Association with Clinical Outcomes in Patients with Vasospastic Angina.

PubMed

Gwag, Hye Bin; Yang, Jeong Hoon; Park, Taek Kyu; Song, Young Bin; Hahn, Joo Yong; Choi, Jin Ho; Lee, Sang Hoon; Gwon, Hyeon Cheol; Choi, Seung Hyuk

2017-08-01

No data are available on the association of serum uric acid and vasospastic angina (VSA) which has endothelial dysfunction as a possible pathophysiologic mechanism. Low uric acid level might cause adverse outcomes in VSA in connection with endothelial dysfunction. We enrolled 818 VSA patients whose uric acid level was measured at admission. Patients were categorized according to tertiles of uric acid level: group I, ≤ 4.8 mg/dL; group II, 4.9-5.9 mg/dL; and group III, ≥ 6.0 mg/dL. Primary outcome was major adverse cardiac events (MACEs), defined as a composite of cardiac death, acute myocardial infarction (MI), ischemic stroke, coronary revascularization, and rehospitalization for angina. Median follow-up duration was 49.2 months. Median uric acid values were 4.1 mg/dL for group I, 5.4 mg/dL for group II, and 6.7 mg/dL for group III. In the overall population, group II had a significantly lower incidence of MACE compared to group I (47 [17.1%] vs. 66 [24.6%]; hazard ratio [HR], 1.52; 95% confidence interval [CI], 1.02-2.26; P = 0.040) and a tendency of lower incidence of MACEs compared to Group III (47 [17.1%] vs. 62 [22.5%]; HR, 1.44; 95% CI, 0.98-2.13; P = 0.067). Among group I patients, those who received nitrates had a higher incidence of MACEs than those without nitrate therapy (P < 0.001). Low uric acid level was associated with adverse clinical outcomes, while high uric acid level had a trend toward an increase in it. Use of nitrate in patients with low uric acid level might have adverse effects on clinical outcomes of VSA. © 2017 The Korean Academy of Medical Sciences.

Comparison the effectiveness of pyruvic acid 50% and salicylic acid 30% in the treatment of acne

PubMed Central

Jaffary, Fariba; Faghihi, Gita; Saraeian, Sara; Hosseini, Sayed Mohsen

2016-01-01

Background: Acne vulgaris is a chronic inflammatory disease of the pilosebaceous follicles and one of the most common skin diseases. The peeling method has been recently found to be effective for acne treatment. This study aimed to compare the efficacy of pyruvic acid 50% and salicylic acid 30% peeling in the treatment of mild to moderate acne. Materials and Methods: In a prospective single-blinded clinical trial, 86 patients with acne were randomly assigned into two groups. In both groups, the routine treatment of acne (topical solution of erythromycin 4%, triclorocarban soap, and sunscreen) were used twice a day for 8 weeks. In addition, salicylic acid 30% for the control group and pyruvic acid 50% for the case group were used. In both groups, acne severity index (ASI) was calculated before and at week 2, 4, 6, and 8 of the treatment. Patient satisfaction was assessed at the end of the treatment. Side effects were recorded using a checklist. Results: In both groups, the reduction in the number of comedones, papules, and ASI were statistically significant (P < 0.001) in the course of treatment. However, it was not significant regarding the number of pustules (P = 0.09). None of the number of comedone, papules, pustules, and ASI was statistically different between study groups. Both treatment groups had similar side effects except for scaling in the fifth session, which was significantly lower in salicylic acid – treated patients (P = 0.015). Conclusion: Both pyruvic acid 50% and salicylic acid 30% are effective in the improvement of mild to moderate acne with no significant difference in efficacy and side effects. PMID:27904577

Effect of Acid on Surface Hydroxyl Groups on Kaolinite and Montmorillonite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sihvonen, Sarah K.; Murphy, Kelly A.; Washton, Nancy M.

Mineral dust aerosol participates in heterogeneous chemistry in the atmosphere. In particular, the hydroxyl groups on the surface of aluminosilicate clay minerals are important for heterogeneous atmospheric processes. These functional groups may be altered by acidic processing during atmospheric transport. In this study, we exposed kaolinite (KGa-1b) and montmorillonite (STx-1b) to aqueous sulfuric acid and then rinsed the soluble reactants and products off in order to explore changes to functional groups on the mineral surface. To quantify the changes due to acid treatment of edge hydroxyl groups, we use 19F magic angle spinning nuclear magnetic resonance spectroscopy and a probemore » molecule, 3,3,3-trifluoropropyldimethylchlorosilane. We find that the edge hydroxyl groups (OH) increase in both number and density with acid treatment. Chemical reactions in the atmosphere may be impacted by the increase in OH at the mineral edge.« less

Biological response to purification and acid functionalization of carbon nanotubes

NASA Astrophysics Data System (ADS)

Figarol, Agathe; Pourchez, Jérémie; Boudard, Delphine; Forest, Valérie; Tulliani, Jean-Marc; Lecompte, Jean-Pierre; Cottier, Michèle; Bernache-Assollant, Didier; Grosseau, Philippe

2014-07-01

Acid functionalization has been considered as an easy way to enhance the dispersion and biodegradation of carbon nanotubes (CNT). However, inconsistencies between toxicity studies of acid functionalized CNT remain unexplained. This could be due to a joint effect of the main physicochemical modifications resulting from an acid functionalization: addition of surface acid groups and purification from catalytic metallic impurities. In this study, the impact on CNT biotoxicity of these two physiochemical features was assessed separately. The in vitro biological response of RAW 264.7 macrophages was evaluated after exposure to 15-240 µg mL-1 of two types of multi-walled CNT. For each type of CNT (small: 20 nm diameter, and big: 90 nm diameter), three different surface chemical properties were studied (total of six CNT samples): pristine, acid functionalized and desorbed. Desorbed CNT were purified by the acid functionalization but presented a very low amount of surface acid groups due to a thermal treatment under vacuum. A Janus effect of acid functionalization with two opposite impacts is highlighted. The CNT purification decreased the overall toxicity, while the surface acid groups intensified it when present at a specific threshold. These acid groups especially amplified the pro-inflammatory response. The threshold mechanism which seemed to regulate the impact of acid groups should be further studied to determine its value and potential link to the other physicochemical state of the CNT. The results suggest that, for a safer-design approach, the benefit-risk balance of an acid functionalization has to be considered, depending on the CNT primary state of purification. Further research should be conducted in this direction.

'Designer oils' low in n-6:n-3 fatty acid ratio beneficially modifies cardiovascular risks in mice.

PubMed

Riediger, Natalie D; Azordegan, Nazila; Harris-Janz, Sydney; Ma, David W L; Suh, Miyoung; Moghadasian, Mohammed H

2009-08-01

Cardiovascular benefits of dietary n-3 fatty acids have been shown. However, benefits of n-3 fatty acids as part of a high fat, low n-6:n-3 fatty acid ratio diet has not been fully characterized. Aim of this study is to investigate cardiovascular and metabolic benefits of 'designer oils' containing a low ratio of n-6:n-3 fatty acids in C57BL/6 mice. Three groups of C57BL/6 mice were fed an atherogenic diet supplemented with either a fish oil- or flaxseed oil-based 'designer oil' with an approximate n-6:n-3 fatty acid ratio of 2:1 (treated groups, n = 6 each) or with a safflower oil-based formulation with a high ratio (25:1) of n-6:n-3 fatty acids (control group, n = 6) for 6 weeks. Food intake, body weight, and blood lipid levels were monitored regularly. Fatty acid profile of the heart tissues was assessed. Histological assessment of liver samples was conducted. At the end of the study body weight and food intake was significantly higher in the flax group compared to control. The levels of 20:5n-3 and 22:6n-3 was significantly increased in the heart phospholipids in both flax and fish groups compared to control; tissue 20:4n-6 was significantly reduced in the fish group compared to control. Significant liver pathology was observed in the control group only. Lowering dietary ratio of n-6:n-3 fatty acids may significantly reduce cardiovascular and metabolic risks in mice regardless of the source of n-3 fatty acids.

Effect of tranexamic acid on intraoperative blood loss and transfusion requirements in patients undergoing excision of intracranial meningioma.

PubMed

Hooda, Bhavna; Chouhan, Rajendra Singh; Rath, Girija Prasad; Bithal, Parmod Kumar; Suri, Ashish; Lamsal, Ritesh

2017-07-01

Surgical excision of meningioma is often complicated by significant blood loss requiring blood transfusion with its attendant risks. Although tranexamic acid is used to reduce perioperative blood loss, its blood conservation effect is uncertain in neurosurgery. Sixty adults undergoing elective craniotomy for meningioma excision were randomized to receive either tranexamic acid or placebo, initiated prior to skin incision. Patients in the tranexamic acid group received intravenous bolus of 20mg/kg over 20min followed by an infusion of 1mg/kg/h till the conclusion of surgery. Intraoperative blood loss, transfusion requirements and estimation of surgical hemostasis using a 5-grade scale were noted. Postoperatively, the extent of tumor excision on CT scan and complications were observed. Demographics, tumor characteristics, amount of fluid infusion, and duration of surgery and anesthesia were comparable between the two groups. The amount of blood loss was significantly less in tranexamic acid group compared to placebo (830mlvs 1124ml; p=0.03). The transfusion requirement was less in tranexamic acid group (p>0.05). The patients in tranexamic acid group fared better on a 5-grade surgical hemostasis scale with more patients showing good hemostasis (p=0.007). There were no significant differences between the groups with regards to extent of tumor removal, perioperative complications, hospital stay or neurologic outcome. To conclude, administration of tranexamic acid significantly reduced blood loss in patients undergoing excision of meningioma. Fewer patients in the tranexamic acid group received blood transfusions. Surgical field hemostasis was better achieved in patients who received tranexamic acid. Copyright © 2017 Elsevier Ltd. All rights reserved.

Benefits of foods supplemented with vegetable oils rich in α-linolenic, stearidonic or docosahexaenoic acid in hypertriglyceridemic subjects: a double-blind, randomized, controlled trail.

PubMed

Dittrich, Manja; Jahreis, Gerhard; Bothor, Kristin; Drechsel, Carina; Kiehntopf, Michael; Blüher, Matthias; Dawczynski, Christine

2015-09-01

The aim of the study was to investigate the influence of foods enriched with vegetable oils varying in their n-3 polyunsaturated fatty acids profile on cardiovascular risk factors for hypertriglyceridemic subjects. Fifty-nine hypertriglyceridemic subjects (triglycerides ≥ 1.5 mmol/L) were included in the randomized, double-blind, placebo-controlled, crossover study. The placebo group received sunflower oil [linoleic acid (LA) group; 10 g LA/day]. The intervention groups received linseed oil [α-linolenic acid (ALA) group; 7 g ALA/day], echium oil [stearidonic acid (SDA) group; 2 g SDA/day] or microalgae oil [docosahexaenoic acid (DHA) group; 2 g DHA/day] over 10 weeks. Blood samples were collected at baseline and at the end of each period. Total cholesterol (TC) and low-density-lipoprotein cholesterol decreased significantly in the LA and ALA groups (LA: P ≤ 0.01, ALA: P ≤ 0.05). No changes in blood lipids were observed in the SDA group. Significant increases in TC and high-density-lipoprotein cholesterol occurred in the DHA group (P ≤ 0.05). In the ALA and SDA groups, the content of eicosapentaenoic acid in erythrocyte lipids increased significantly (P ≤ 0.05) after 10 weeks (ALA group: 38 ± 37 %, SDA group: 73  ± 59 %). Foods enriched with different vegetable oils rich in ALA or SDA are able to increase the n-3 long-chain polyunsaturated fatty acids content in erythrocyte lipids; echium oil is more potent in comparison with linseed oil. Blood lipids were beneficially modified through the consumption of food products enriched with sunflower, linseed and microalgae oils, whereas echium oil did not affect blood lipids. ClinicalTrials.gov: NCT01437930.

α-Lipoic acid reduced weight gain and improved the lipid profile in rats fed with high fat diet.

PubMed

Seo, Eun Young; Ha, Ae Wha; Kim, Woo Kyoung

2012-06-01

The purpose of this study was to investigate the effects of α-lipoic acid on body weight and lipid profiles in Sprague-Dawley rats fed a high fat diet (HFD). After 4 weeks of feeding, rats on the HFD were divided into three groups by randomized block design; the first group received the high-fat-diet (n = 10), and the second group received the HFD administered with 0.25% α-lipoic acid (0.25LA), and the third group received the high-fat diet with 0.5% α-lipoic acid (0.5LA). The high fat diet with α-lipoic acid supplemented groups had significantly inhibited body weight gain, compared to that in the HFD group (P < 0.05). Organ weights of rats were also significantly reduced in liver, kidney, spleen, and visible fat tissues in rats supplemented with α-lipoic acid (P < 0.05). Significant differences in plasma lipid profiles, such as total lipids, total cholesterol, triglycerides, low-density lipoprotein, and high-density lipoprotein, were observed between the HFD and 0.5LA groups. The atherogenic index and the plasma high density lipoprotein-cholesterol/total cholesterol ratio improved significantly with α-lipoic acid supplementation in a dose-dependent manner (P < 0.05). Total hepatic cholesterol and total lipid concentration decreased significantly in high fat fed rats supplemented with α-lipoic acid in a dose-dependent manner (P < 0.05), whereas liver triglyceride content was not affected. In conclusion, α-lipoic acid supplementation had a positive effect on weight gain and plasma and liver lipid profiles in rats.