Exploring miR-9 Involvement in Ciona intestinalis Neural Development Using Peptide Nucleic Acids

The microRNAs are small RNAs that regulate gene expression at the post-transcriptional level and can be involved in the onset of neurodegenerative diseases and cancer. They are emerging as possible targets for antisense-based therapy, even though the in vivo stability of miRNA analogues is still questioned. We tested the ability of peptide nucleic acids, a novel class of nucleic acid mimics, to downregulate miR-9 in vivo in an invertebrate model organism, the ascidian Ciona intestinalis, by microinjection of antisense molecules in the eggs. It is known that miR-9 is a well-conserved microRNA in bilaterians and we found that it is expressed in epidermal sensory neurons of the tail in the larva of C. intestinalis. Larvae developed from injected eggs showed a reduced differentiation of tail neurons, confirming the possibility to use peptide nucleic acid PNA to downregulate miRNA in a whole organism. By identifying putative targets of miR-9, we discuss the role of this miRNA in the development of the peripheral nervous system of ascidians

Chemical Characterization and Nematicidal Activity of the Essential Oil of Nepeta nuda L. ssp. pubescens and Nepeta curviflora Boiss. from Lebanon

The chemical characterization and the nematicidal activity of the essential oils from Nepeta nuda L. ssp. pubescens and Nepeta curviflora Boiss. growing wild in Lebanon are reported. A comparative study was carried out as, to the best of our knowledge, no information is available on Nepeta nuda L. ssp. pubescens. In addition, both Nepeta species were collected in the same geographical area in order to rule out the environmental factors influencing essential oil composition and bioactivity. The most abundant (> 5 %) components of N. nuda ssp. pubescens essential oil were pinene (12.89 %), 1-ethyl-1H-pyrrole (12.67 %), 1-cycloethyl- 1-(2-methylenecyclohexyl) ethanol (10.37 %), 3-methyl-2-cyclohexen-1-one (9.17 %) and 2,3-dimethyl-3- hexanol (5.88 %). Among oxygenated monoterpenes, two nepetalactones were identified, i.e. (E, Z)nepetalactone (2.24 %) and (Z, E)-nepetalactone (0.31 %). The major constituents (> 5 %) of N. curviflora essential oil were 2-isopropyl-5-methyl-3-cyclohexen-1-one (12.51%), (-)-spathulenol (11.73%), cis-Z-alpha-bisabolene epoxide (8.07 %), widdrol (7.0 %), (E, Z)-5,7-dodecadiene (6.93 %), dihydronepetalactone (5.57 %) and 4-propyl-cyclohexene (5.43 %). The essential oil of N. curviflora was more active than the N. nuda ssp. pubescens one against the nematode Panagrolaimus rigidus. According to the motility assay, LD50 was 0.5 mg/mL and 2.5 mg/mL 24 h after treatment with N. curviflora and N. nuda ssp. pubescens essential oil, respectively

proPO system of Allogamus auricollis (Insecta): Effects of various compounds on phenoloxidase activity

The phenoloxidase activity in the hemolymph cell-free fraction from Allogamus auricollis was studied in the presence of Escherichia coli lipopolysaccharides and Saccharomyces cerevisiae \u3b2-1,3-glucans. The proPO system seems to be strongly activated by lipopolysaccharides (LPS). The basic activation observed in this model appears not to be affected by the use of protease inhibitors (\u3b12 macroglobulin, soybean trypsin inhibitor), and, in addition, the LPS-activated proPO system is not inhibited by their presence. Calcium ions at high concentrations inhibit the phenoloxidase activity, and EDTA chelation strongly enhances dopachrome formation. Analytical polyacrylamide gel electrophoresis (PAGE) of the hemolymph cell-free fraction showed two main components, with a molecular mass of 76 and 80 kDa. After electro-elution from a native PAGE of L-dihydroxy-phenylalanine positive bands, the analytical SDS-PAGE again showed the same two major bands

Au-thymine, thymidine and thymidine 5\u2019-monophosphate nanoparticles: chemical characterisation and cellular uptake studies into U87 cancer cells

Gold nanoparticles were obtained by reduction of a tetrachloroaurate aqueous solution in the presence of a RGD-(GC)2 peptide as stabiliser. As comparison, the behaviour of the (GC)2 peptide has been studied. The (GC)2 and RGD-(GC)2 peptides were prepared ad hoc by Fmoc syntheses. The colloidal systems have been characterised by UV-visible, ATR-FTIR, mono and bidimensional NMR techniques and Confocal and TEM microscopies. The efficient cellular uptake of Au-RGD-(GC)2 and Au-(GC)2 stabilised gold particles into U87 cells (human glioblastoma cell), were investigated by confocal microscopy and compared with the behaviour of the (GC)2 capped gold nanoparticles. A quantitative determination of the uptaken nanoparticles have been carried out by measuring the pixel brightness of the images that highlighted the importance of the RGD termination of the peptide. A deep insight of the cellular uptake mechanism was investigated by TEM microscopy. Various important evidences indicated the selective uptake of RGD-(GC)2 gold nanoparticles into the nucleus

Biochemical evidence of phenoloxidase activity (pro-PO system) in larvae of Allogamus auricollis (Insecta, Trichoptera)

1. 1. Allogamus auricollis cell-free hemolymph proteins were analyzed by SDS-PAGE. Under reducing conditions the gel pattern showed two main components (83 and 76 kDa) and some lesser bands. 2. 2. After native PAGE, a single band showed phenoloxidase activity by in situ enzymatic staining. 3. 3. Spectrophotometric analysis of the cell-free plasma fraction was carried out with substrate and PTU as inhibitor

Synthesis and full characterisation of nickel(II) colloidal particles and their transformation into NiO

Monodispersed nickel(II) particles were achieved by ageing aqueous solutions of NiSO4\ub76H2O in the presence of urea, at 90\ub0C for 3.5 h. Working up this colloidal dispersion led to a green powder with the stoichiometry 5[Ni3(OH)5(NCO)]\ub7[NiCO3]\ub7[H2O]. This mixed salt was characterised by extensive spectroscopic investigations and chemical\u2013physical analyses. The nickel intermediate was further thermally decomposed at various temperatures, under both aerobic and anaerobic conditions, and gave black mono dispersed particles of Ni(II) and Ni(III) oxides. The phase transformations were studied in detail and the oxidation products (NiO and NiO(OH)) were characterised

New Au(0) sols as precursors for heterogeneous liquid-phase oxidation catalysts

New Au(0) sols were obtained by reducing antic compounds (AuCl3, NaAuC4, and HAuCl4)with reducing compounds (H2C2O4, SnCl2, and NaBH4) in the presence of protective agents [polyvinylalcohol, PVA, and poly(diallyldimethylammonium chloride), PDDA] in aqueous solutions. The sols, characterized by TEM microscopy and UV-visible spectroscopy, consisted of nanoparticles of different sizes depending on the preparation method. The colloidal solutions were immobilized on activated carbon and titania. The obtained heterogeneous catalysts were tested in the selective liquid-phase oxidation of ethylene glycol to glycolate (pO(2) = 300 kPa, T = 343 K, r.t. = 1 h, [EG] = 0.5 M, EG/Au = 1000, EG/NaOH = 1, EG = ethylene glycol). A comparison of the catalytic activity underlines the importance of using the correct sol with respect to the support. (C) 2002 Elsevier Science (USA)

Synthesis of Au(0) nanoparticles from W/O microemulsions

Clear W/O microemulsions of NaAuCl4 and NaBH4 Can be obtained using the four components: cetyltrimethylammonium bromide, 1-butanol, n-octane and aqueous solutions of inorganic salts. They can be mixed giving microemulsions of Au(0) nanoparticles in the micellar cores. The red gold systems have been supported on activated carbon and tested in the catalytic liquid phase selective oxidation of glycol to glycolate by O-2