Identification of a DNA aptamer that inhibits sclerostin's antagonistic effect on Wnt signalling

Sclerostin is an extracellular negative regulator of bone formation that is a recognized therapeutic target for osteoporosis therapy. In the present study, we performed DNA aptamer selection against sclerostin, then characterized aptamer–sclerostin binding and the ability to inhibit sclerostin function in cell culture. We show that a selected DNA aptamer was highly selective for binding to sclerostin with affinities in the nanomolar range as determined by solid-phase assays and by isothermal titration calorimetry. Binding between sclerostin and the aptamer was exothermic and enthalpically driven. CD confirmed that the aptamer had temperature-dependent parallel G-quadruplex characteristics. The aptamer was stabilized with 3′ inverted thymidine to investigate efficacy at inhibiting sclerostin function in cell culture. The stabilized DNA aptamer showed potent and specific dose-dependent inhibition of sclerostin's antagonistic effect on Wnt activity using a reporter assay. Taken together, the present findings suggest an alternative approach to inhibiting sclerostin function with therapeutic potential.

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Triazolylthioacetamides Confer Inhibitory Efficacy against Metallo-β-Lactamase IMP-1

Letters in Drug Design & Discovery ◽

10.2174/1570180817999200831094019 ◽

2020 ◽

Vol 17 ◽

Author(s):

Yue-Juan Zhang ◽

Le Zhai ◽

Yi Wan ◽

Ke-Wu Yang

Keyword(s):

Antibiotic Resistance ◽

Antimicrobial Activities ◽

Docking Studies ◽

Titration Calorimetry ◽

Global Public Health ◽

Inhibition Activity ◽

Dependent Inhibition ◽

Dose Dependent Inhibition

Background: : The appearance of antibiotic resistance caused by metallo-β-lactamases (MβLs) is a global public health threat. Developing MβLs inhibitor is an effective way to overcome antibiotic resistance. Recently, azolylthioacetamides were reported to be promising MβLs inhibitors. Methods:: Triazolylthioacetamides were synthesized and tested for inhibition activity against the purified MβL IMP-1. Antimicrobial activities of these inhibitors in combination with cefazolin were evaluated. Isothermal titration calorimetry (ITC) was employed to characterize the binding of the inhibitor to IMP-1, and their action mechanism was studied by molecular docking. Results and Discussion: : Twenty compounds exhibited specific inhibitory activity against IMP-1 with an IC50 value in the range of 3.1-62.5 μM. Eight of the compounds can restore the antibacterial efficacy of cefazolin against E. coli BL21 strain producing IMP-1 by 2-4 fold. ITC monitoring showed that 1c exhibited dose-dependent inhibition on IMP-1. Docking studies revealed that the triazole group in 1c and 2d played an essential role in the inhibition activity. Cytotoxicity assay showed that 1c and 2d have low toxicity in L929 mouse fibroblastic cells. Conclusion: : The triazolylthioacetamides are efficient inhibitors of IMP-1 in vitro and in vivo.

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VP35 Knockdown Inhibits Ebola Virus Amplification and Protects against Lethal Infection in Mice

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.50.3.984-993.2006 ◽

2006 ◽

Vol 50 (3) ◽

pp. 984-993 ◽

Cited By ~ 86

Author(s):

Sven Enterlein ◽

Kelly L. Warfield ◽

Dana L. Swenson ◽

David A. Stein ◽

Jeffery L. Smith ◽

...

Keyword(s):

Cell Culture ◽

Ebola Virus ◽

Rna Viruses ◽

Marburg Virus ◽

Lethal Infection ◽

Dependent Inhibition ◽

Dna Analogs ◽

Ebov Infection ◽

Dose Dependent Inhibition ◽

Positive Strand Rna

ABSTRACT Phosphorodiamidate morpholino oligomers (PMO) are a class of uncharged single-stranded DNA analogs modified such that each subunit includes a phosphorodiamidate linkage and morpholine ring. PMO antisense agents have been reported to effectively interfere with the replication of several positive-strand RNA viruses in cell culture. The filoviruses, Marburg virus and Ebola virus (EBOV), are negative-strand RNA viruses that cause up to 90% lethality in human outbreaks. There is currently no commercially available vaccine or efficacious therapeutic for any filovirus. In this study, PMO conjugated to arginine-rich cell-penetrating peptide (P-PMO) and nonconjugated PMO were assayed for the ability to inhibit EBOV infection in cell culture and in a mouse model of lethal EBOV infection. A 22-mer P-PMO designed to base pair with the translation start site region of EBOV VP35 positive-sense RNA generated sequence-specific and time- and dose-dependent inhibition of EBOV amplification in cell culture. The same oligomer provided complete protection to mice when administered before or after an otherwise lethal infection of EBOV. A corresponding nonconjugated PMO, as well as nonconjugated truncated versions of 16 and 19 base residues, provided length-dependent protection to mice when administered prophylactically. Together, these data suggest that antisense PMO and P-PMO have the potential to control EBOV infection and are promising therapeutic candidates.

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Solid-phase immunoelectron microscopy for rapid diagnosis of enteroviruses

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100111240 ◽

1984 ◽

Vol 42 ◽

pp. 226-227 ◽

Cited By ~ 1

Author(s):

K. Pegg-Feige ◽

F. W. Doane

Keyword(s):

Electron Microscopy ◽

Cell Culture ◽

Immunoelectron Microscopy ◽

Detection Method ◽

Solid Phase ◽

Protein A ◽

Plant Viruses ◽

Rapid Diagnosis ◽

Virus Diagnosis ◽

Antiviral Antibody

Immunoelectron microscopy (IEM) applied to rapid virus diagnosis offers a more sensitive detection method than direct electron microscopy (DEM), and can also be used to serotype viruses. One of several IEM techniques is that introduced by Derrick in 1972, in which antiviral antibody is attached to the support film of an EM specimen grid. Originally developed for plant viruses, it has recently been applied to several animal viruses, especially rotaviruses. We have investigated the use of this solid phase IEM technique (SPIEM) in detecting and identifying enteroviruses (in the form of crude cell culture isolates), and have compared it with a modified “SPIEM-SPA” method in which grids are coated with protein A from Staphylococcus aureus prior to exposure to antiserum.

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Differences between antigenic determinants of pig and cat zona pellucida proteins

Reproduction ◽

10.1530/reprod/119.1.15 ◽

2000 ◽

pp. 15-23 ◽

Cited By ~ 15

Author(s):

K Jewgenow ◽

M Rohleder ◽

I Wegner

Keyword(s):

In Vitro Fertilization ◽

Zona Pellucida ◽

Antigenic Determinants ◽

Vitro Fertilization ◽

Contraceptive Vaccine ◽

Sperm Binding ◽

Dependent Inhibition ◽

Dose Dependent Inhibition ◽

Dose Dependent

Despite many efforts, the control of reproduction in feral cat populations is still a problem in urban regions around the world. Immunocontraception is a promising approach; thus the present study examined the suitability of the widely used pig zona pellucida proteins (pZP) for contraception in feral domestic cats. Purified zona pellucida proteins obtained from pig and cat ovaries were used to produce highly specific antisera in rabbits. Antibodies against pZP raised in rabbits or lions were not effective inhibitors of either in vitro sperm binding (cat spermatozoa to cat oocytes) or in vitro fertilization in cats, whereas antibodies against feline zona pellucida proteins (fZP) raised in rabbits showed a dose-dependent inhibition of in vitro fertilization. Immunoelectrophoresis, ELISA and immunohistology of ovaries confirmed these results, showing crossreactivity of anti-fZP sera to fZP and to a lesser extent to pZP, but no interaction of anti-pZP sera with fZP. It is concluded that cat and pig zonae pellucidae express a very small number of shared antigenic determinants, making the use of pZP vaccine in cats questionable. A contraceptive vaccine based on feline zona pellucida determinants will be a better choice for the control of reproduction in feral cats if immunogenity can be achieved.

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Antioxidant effects and in vitro cytotoxicity on human cancer cell lines of flavonoid-rich Flamboyant (Delonix regia (Bojer) Raf.) flower extract

Current Pharmaceutical Biotechnology ◽

10.2174/1389201021666201029154746 ◽

2020 ◽

Vol 21 ◽

Author(s):

Putthiporn Khongkaew ◽

Phanphen Wattanaarsakit ◽

Konstantinos I. Papadopoulos ◽

Watcharaphong Chaemsawang

Keyword(s):

Cell Line ◽

Cell Lines ◽

Cancer Cell ◽

Leukemia Cell ◽

Leukemia Cell Line ◽

Flower Extract ◽

Dependent Inhibition ◽

Dose Dependent Inhibition ◽

Murine Leukemia Cell ◽

Dose Dependent

Background: Cancer is a noncommunicable disease with increasing incidence and mortality rates both worldwide and in Thailand. Its apparent lack of effective treatments is posing challenging public health issues. Introduction: Encouraging research results indicating probable anti-cancer properties of the Delonix regia flower extract (DRE) have prompted us to evaluate the feasibility of developing a type of product for future cancer prevention or treatment. Methods and Results: In the present report, using High Performance Liquid Chromatography (HPLC), we demonstrate in the DRE, the presence of high concentrations of three identifiable flavonoids, namely rutin 4.15±0.30 % w/w, isoquercitrin 3.04±0.02 %w/w, and myricetin 2.61±0.01 % w/w respectively while the IC50 of DPPH and ABTS assay antioxidation activity was 66.88±6.30 µg/ml and 53.65±7.24 µg/ml respectively. Discussion: Our cancer cell line studies using the MTT assay demonstrated DREs potent and dose dependent inhibition of murine leukemia cell line (P-388: 35.28±4.07% of cell viability remaining), as well as of human breast adenocarcinoma (MCF-7), human cervical carcinoma (HeLa), human oral cavity carcinoma (KB), and human colon carcinoma (HT-29) cell lines in that order of magnitude. Conclusion: Three identifiable flavonoids (rutin, isoquercitrin and myricetin) with high antioxidation activity and potent and dose dependent inhibition of murine leukemia cell line and five other cancer cell lines were documented in the DRE. The extract’s lack of cytotoxicity in 3 normal cell lines is a rare advantage not usually seen in current antineoplastic agents. Yet another challenge of the DRE was its low dissolution rate and long-term storage stability, issues to be resolved before a future product can be formulated.

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Investigation on the antibacterial activity of electronic cigarette liquids (ECLs): a proof of concept study

Current Pharmaceutical Biotechnology ◽

10.2174/1389201021666200903121624 ◽

2020 ◽

Vol 21 ◽

Cited By ~ 1

Author(s):

Virginia Fuochi ◽

Massimo Caruso ◽

Rosalia Emma ◽

Aldo Stivala ◽

Riccardo Polosa ◽

...

Keyword(s):

Antibacterial Activity ◽

Bacterial Species ◽

A549 Cells ◽

Bactericidal Effect ◽

Minimal Bactericidal Concentration ◽

Viability Assay ◽

Dependent Inhibition ◽

Dose Dependent Inhibition ◽

Dose Dependent

Background: The key ingredients of e-cigarettes liquid are commonly propane-1,2-diol (also called propylene glycol) and propane-1,2,3-triol (vegetal glycerol) and their antimicrobial effects are already established. The nicotine and flavors which are often present in e-liquids can interfere with the growth of some microorganisms. Objective: The effect of the combining these elements in e-liquids is unknown. The aim of the study was to investigate the possible effects of these liquids on bacterial growth in the presence or absence of nicotine and flavors. Methods: Susceptibilities of pathogenic strains (Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli, Enterococcus faecalis and Sarcina lutea) were studied by means of a multidisciplinary approach. Cell viability and antioxidant assays were also evaluated. Results: All e-liquids investigated showed antibacterial activity against at least one pathogenic strain. A higher activity was correlated to the presence of flavors and nicotine. Discussion: In most cases the value of minimal bactericidal concentration is equal to the value of minimal inhibitory concentration showing that these substances have a bactericidal effect. This effect was observed in concentrations up to 6.25% v/v. Antioxidant activity was also correlated to presence of flavors. Over time, the viability assay in human epithelial lung A549 cells showed a dose-dependent inhibition of cell growth. Conclusion: Our results have shown that flavors considerably enhance the antibacterial activity of propane-1,2-diol and propane-1,2,3-triol. This study provides important evidence that should be taken into consideration in further investigative approaches, to clarify the different sensitivity of the various bacterial species to e-liquids, including the respiratory microbiota, to highlight the possible role of flavors and nicotine.

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In VitroActivities of Hexaazatrinaphthylenes against Leishmania spp.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00226-15 ◽

2015 ◽

Vol 59 (5) ◽

pp. 2867-2874 ◽

Cited By ~ 13

Author(s):

Atteneri López-Arencibia ◽

Daniel García-Velázquez ◽

Carmen M. Martín-Navarro ◽

Ines Sifaoui ◽

María Reyes-Batlle ◽

...

Keyword(s):

Therapeutic Agents ◽

Content Type ◽

Inhibition Effect ◽

Intracellular Amastigotes ◽

Dependent Inhibition ◽

Leishmania Spp ◽

Dose Dependent Inhibition ◽

Dose Dependent ◽

Potential Use

ABSTRACTThein vitroactivity of a novel group of compounds, hexaazatrinaphthylene derivatives, against two species ofLeishmaniais described in this study. These compounds showed a significant dose-dependent inhibition effect on the proliferation of the parasites, with 50% inhibitory concentrations (IC50s) ranging from 1.23 to 25.05 μM against the promastigote stage and 0.5 to 0.7 μM against intracellular amastigotes. Also, a cytotoxicity assay was carried out to in order to evaluate the possible toxic effects of these compounds. Moreover, different assays were performed to determine the type of cell death induced after incubation with these compounds. The obtained results highlight the potential use of hexaazatrinaphthylene derivatives againstLeishmaniaspecies, and further studies should be undertaken to establish them as novel leishmanicidal therapeutic agents.

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μ-Opiate Receptors in Neuronal Primary Cultures from Cerebral Cortex

Alternatives to Laboratory Animals ◽

10.1177/026119299001700308 ◽

1990 ◽

Vol 17 (3) ◽

pp. 177-181

Author(s):

Peter S. Eriksson ◽

Elisabeth Hansson ◽

Lars Rönnbäck

Keyword(s):

Cerebral Cortex ◽

Primary Cultures ◽

Opiate Receptors ◽

Neuronal Cultures ◽

Camp Accumulation ◽

Dependent Inhibition ◽

Dose Dependent Inhibition ◽

Neuronal Primary Cultures ◽

Dose Dependent ◽

Μ Receptor

The presence of μ-opioid receptors was demonstrated as effects of receptor stimulation on PGE1-induced cAMP accumulation in neuronal-enriched primary cultures from rat cerebral cortex. Morphine was used as a μ-receptor agonist. There was a dose-dependent inhibition of the PGE1-stimulated cAMP accumulation by morphine, blocked by the μ-receptor antagonist naloxone. These findings suggest that these neuronal cultures express μ-receptors, possibly connected to adenylate cyclase via an inhibitory Gi-protein. The probable use of functional μ-receptors in neurotoxicological tests is discussed.

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