9 research outputs found
In vitro toxicity of FemOn, FemOn-SiO2 composite, and SiO2-FemOn core-shell magnetic nanoparticles
Yana G Toropova,1 Alexey S Golovkin,2 Anna B Malashicheva,3,4 Dmitry V Korolev,5,6 Andrey N Gorshkov,7 Kamil G Gareev,8 Michael V Afonin,9 Michael M Galagudza10,11 1Laboratory of Cardioprotection, Institute of Experimental Medicine, Federal Almazov North-West Medical Research Centre, Saint Petersburg, Russian Federation; 2Gene and Cell Engineering Group, Institute of Molecular Biology and Genetics, Federal Almazov North-West Medical Research Centre, Saint Petersburg, Russian Federation; 3Laboratory of Molecular Cardiology, Institute of Molecular Biology and Genetics, Federal Almazov North-West Medical Research Centre, Saint Petersburg, Russian Federation; 4Department of Embryology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russian Federation; 5Laboratory of Nanotechnology, Institute of Experimental Medicine, Federal Almazov North-West Medical Research Centre, Saint Petersburg, Russian Federation; 6Department of Photonics and Optical Information Technology ITMO University, Saint Petersburg, Russian Federation; 7Laboratory of Intracellular Signaling and Transport Research Institute of Influenza, Saint Petersburg, Russian Federation; 8Department of Micro and Nanoelectronics, Faculty of Electronics, Saint Petersburg Electrotechnical University LETI, Saint Petersburg, Russian Federation; 9Department of Inorganic Chemistry Saint Petersburg State Technological Institute (Technical University), Saint Petersburg, Russian Federation; 10Institute of Experimental Medicine, Federal Almazov North-West Medical Research Centre, Saint Petersburg, Russian Federation; 11Departament of Pathophysiology, First Pavlov State Medical University of Saint Petersburg, Saint Petersburg, Russian Federation Abstract: Over the last decade, magnetic iron oxide nanoparticles (IONPs) have drawn much attention for their potential biomedical applications. However, serious in vitro and in vivo safety concerns continue to exist. In this study, the effects of uncoated, FemOn-SiO2 composite flake-like, and SiO2-FemOn core-shell IONPs on cell viability, function, and morphology were tested 48 h postincubation in human umbilical vein endothelial cell culture. Cell viability and apoptosis/necrosis rate were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and annexin V-phycoerythrin kit, respectively. Cell morphology was evaluated using bright-field microscopy and forward and lateral light scattering profiles obtained with flow cytometry analysis. All tested IONP types were used at three different doses, that is, 0.7, 7.0, and 70.0 µg. Dose-dependent changes in cell morphology, viability, and apoptosis rate were shown. At higher doses, all types of IONPs caused formation of binucleated cells suggesting impaired cytokinesis. FemOn-SiO2 composite flake-like and SiO2-FemOn core-shell IONPs were characterized by similar profile of cytotoxicity, whereas bare IONPs were shown to be less toxic. The presence of either silica core or silica nanoflakes in composite IONPs can promote cytotoxic effects. Keywords: iron oxide nanoparticles, composite nanoparticles, silica coating, silica nanoflakes, cytotoxicit
Systematic identification of factors involved in post-transcriptional processes in wheat grain
The original publication can be found at www.springerlink.comPost-transcriptional processing of primary transcripts can significantly affect both the quantity and the structure of mature mRNAs and the corresponding protein products. It is an important mechanism of gene regulation in animals, yeast and plants. Here we have investigated the interactive networks of pre-mRNA processing factors in the developing grain of wheat (Triticum aestivum), one of the world’s major food staples. As a first step we isolated a homologue of the plant specific AtRSZ33 splicing factor, which has been shown to be involved in the early stages of embryo development in Arabidopsis. Real-time PCR showed that the wheat gene, designated TaRSZ38, is expressed mainly in young, developing organs (flowers, root, stem), and expression peaks in immature grain. In situ hybridization and immunodetection revealed preferential abundance of TaRSZ38 in mitotically active tissues of the major storage organ of the grain, the endosperm. The protein encoded by TaRSZ38 was subsequently used as a starting bait in a two-hybrid screen to identify additional factors in grain that are involved in pre-mRNA processing. Most of the identified proteins showed high homology to known splicing factors and splicing related proteins, supporting a role for TaRSZ38 in spliceosome formation and 5′ site selection. Several clones were selected as baits in further yeast two-hybrid screens. In total, cDNAs for 16 proteins were isolated. Among these proteins, TaRSZ22, TaSRp30, TaU1-70K, and the large and small subunits of TaU2AF, are wheat homologues of known plant splicing factors. Several, additional proteins are novel for plants and show homology to known pre-mRNA splicing, splicing related and mRNA export factors from yeast and mammals.Sergiy Lopato, Ljudmilla Borisjuk, Andrew S. Milligan, Neil Shirley, Natalia Bazanova and Peter Langridg