The influence of the structural orientation of amide linkers on the serum compatibility and lung transfection properties of cationic amphiphiles.

PubMed

Srujan, Marepally; Chandrashekhar, Voshavar; Reddy, Rakesh C; Prabhakar, Rairala; Sreedhar, Bojja; Chaudhuri, Arabinda

2011-08-01

Understanding the structural parameters of cationic amphiphiles which can influence gene transfer efficiencies of cationic amphiphiles continues to remain important for designing efficient liposomal gene delivery reagents. Previously we demonstrated the influence of structural orientation of the ester linker (widely used in covalently tethering the polar head and the non-polar tails) in modulating in vitro gene transfer efficiencies of cationic amphiphiles. However, our previously described cationic amphiphiles with ester linkers failed to deliver genes under in vivo conditions. Herein we report on the development of a highly serum compatible cationic amphiphile with circulation stable amide linker which shows remarkable selectivity in transfecting mouse lung. We also demonstrate that reversing structural orientation of the amide linker adversely affects both serum compatibility and the lung selective gene transfer property. Dynamic laser light scattering and atomic force microscopic studies revealed smaller average hydrodynamic sizes of the liposomes of transfection efficient lipid than those for the liposomes of transfection incompetent analog (148 ± 1 nm vs 214 ± 4 nm). Average surface potential of the liposomes of transfection competent amphiphiles were found to be significantly higher than that for the liposomes of transfection incompetent analog (10.7 ± 5.4 mV vs 2.8 ± 1.3 mV, respectively). Findings in fluorescence resonance energy transfer and dye entrapment experiments support lower rigidity and higher biomembrane fusogenicity of the liposomes of the transfection efficient amphiphiles. Importantly, cationic lipoplexes of the novel amide-linker based amphiphile exhibited higher mouse lung selective gene transfer properties than DOTAP, one of the widely used commercially available liposomal lung transfection kits. In summary, the present findings demonstrate for the first time that amide linker structural orientation profoundly influences the serum

Novel mechanism of gene transfection by low-energy shock wave.

PubMed

Ha, Chang Hoon; Lee, Seok Cheol; Kim, Sunghyen; Chung, Jihwa; Bae, Hasuk; Kwon, Kihwan

2015-08-05

Extracorporeal shock wave (SW) therapy has been studied in the transfection of naked nucleic acids into various cell lines through the process of sonoporation, a process that affects the permeation of cell membranes, which can be an effect of cavitation. In this study, siRNAs were efficiently transfected into primary cultured cells and mouse tumor tissue via SW treatment. Furthermore SW-induced siRNA transfection was not mediated by SW-induced sonoporation, but by microparticles (MPs) secreted from the cells. Interestingly, the transfection effect of the siRNAs was transferable through the secreted MPs from human umbilical vein endothelial cell (HUVEC) culture medium after treatment with SW, into HUVECs in another culture plate without SW treatment. In this study, we suggest for the first time a mechanism of gene transfection induced by low-energy SW through secreted MPs, and show that it is an efficient physical gene transfection method in vitro and represents a safe therapeutic strategy for site-specific gene delivery in vivo.

Bio-Orthogonal Mediated Nucleic Acid Transfection of Cells via Cell Surface Engineering.

PubMed

O'Brien, Paul J; Elahipanah, Sina; Rogozhnikov, Dmitry; Yousaf, Muhammad N

2017-05-24

The efficient delivery of foreign nucleic acids (transfection) into cells is a critical tool for fundamental biomedical research and a pillar of several biotechnology industries. There are currently three main strategies for transfection including reagent, instrument, and viral based methods. Each technology has significantly advanced cell transfection; however, reagent based methods have captured the majority of the transfection market due to their relatively low cost and ease of use. This general method relies on the efficient packaging of a reagent with nucleic acids to form a stable complex that is subsequently associated and delivered to cells via nonspecific electrostatic targeting. Reagent transfection methods generally use various polyamine cationic type molecules to condense with negatively charged nucleic acids into a highly positively charged complex, which is subsequently delivered to negatively charged cells in culture for association, internalization, release, and expression. Although this appears to be a straightforward procedure, there are several major issues including toxicity, low efficiency, sorting of viable transfected from nontransfected cells, and limited scope of transfectable cell types. Herein, we report a new strategy (SnapFect) for nucleic acid transfection to cells that does not rely on electrostatic interactions but instead uses an integrated approach combining bio-orthogonal liposome fusion, click chemistry, and cell surface engineering. We show that a target cell population is rapidly and efficiently engineered to present a bio-orthogonal functional group on its cell surface through nanoparticle liposome delivery and fusion. A complementary bio-orthogonal nucleic acid complex is then formed and delivered to which chemoselective click chemistry induced transfection occurs to the primed cell. This new strategy requires minimal time, steps, and reagents and leads to superior transfection results for a broad range of cell types

Cationic lipids: molecular structure/ transfection activity relationships and interactions with biomembranes.

PubMed

Koynova, Rumiana; Tenchov, Boris

2010-01-01

Abstract Synthetic cationic lipids, which form complexes (lipoplexes) with polyanionic DNA, are presently the most widely used constituents of nonviral gene carriers. A large number of cationic amphiphiles have been synthesized and tested in transfection studies. However, due to the complexity of the transfection pathway, no general schemes have emerged for correlating the cationic lipid chemistry with their transfection efficacy and the approaches for optimizing their molecular structures are still largely empirical. Here we summarize data on the relationships between transfection activity and cationic lipid molecular structure and demonstrate that the transfection activity depends in a systematic way on the lipid hydrocarbon chain structure. A number of examples, including a large series of cationic phosphatidylcholine derivatives, show that optimum transfection is displayed by lipids with chain length of approximately 14 carbon atoms and that the transfection efficiency strongly increases with increase of chain unsaturation, specifically upon replacement of saturated with monounsaturated chains.

Reverse Transfection Using Gold Nanoparticles

NASA Astrophysics Data System (ADS)

Yamada, Shigeru; Fujita, Satoshi; Uchimura, Eiichiro; Miyake, Masato; Miyake, Jun

Reverse transfection from a solid surface has the potential to deliver genes into various types of cell and tissue more effectively than conventional methods of transfection. We present a method for reverse transfection using a gold colloid (GC) as a nanoscaffold by generating nanoclusters of the DNA/reagentcomplex on a glass surface, which could then be used for the regulation of the particle size of the complex and delivery of DNA into nuclei. With this method, we have found that the conjugation of gold nanoparticles (20 nm in particle size) to the pEGFP-N1/Jet-PEI complex resulted in an increase in the intensity of fluorescence of enhanced green fluorescent protein (EGFP) (based on the efficiency of transfection) from human mesenchymal stem cells (hMSCs), as compared with the control without GC. In this manner, we constructed a method for reverse transfection using GC to deliver genes into the cells effectively.

Effects of molecular size and chemical factor on plasma gene transfection

NASA Astrophysics Data System (ADS)

Ikeda, Yoshihisa; Motomura, Hideki; Kido, Yugo; Satoh, Susumu; Jinno, Masafumi

2016-07-01

In order to clarify the mechanism of plasma gene transfection, the relationship between transfection efficiency and transferred molecular size was investigated. Molecules with low molecular mass (less than 50 kDa; dye or dye-labeled oligonucleotide) and high molecular mass (more than 1 MDa; plasmid DNA or fragment of plasmid DNA) were transferred to L-929 cells. It was found that the transfection efficiency decreases with increasing in transferred molecular size and also depends on the tertiary structure of transferred molecules. Moreover, it was suggested the transfection mechanism is different between the molecules with low (less than 50 kDa) and high molecular mass (higher than 1 MDa). For the amount of gene transfection after plasma irradiation, which is comparable to that during plasma irradiation, it is shown that H2O2 molecules are the main contributor. The transfection efficiency decreased to 0.40 ± 0.22 upon scavenging the H2O2 generated by plasma irradiation using the catalase. On the other hand, when the H2O2 solution is dropped into the cell suspension without plasma irradiation, the transfection efficiency is almost 0%. In these results, it is also suggested that there is a synergetic effect of H2O2 with electrical factors or other reactive species generated by plasma irradiation.

Recombination and Transfection Mapping of Cistron 5 of Bacteriophage Sp82g

PubMed Central

Green, D. MacDonald; Urban, Margeret I.

1972-01-01

Recombination between transfecting SP82G DNA molecules has been studied in Bacillus subtilis. Recombinant progeny issuing from transfected cells show many of the features that characterize progeny production in multiplicity reactivated bacteriophage, such as: majority recombinant clones, non-reciprocity of recombinant clones and the frequent absence of input alleles. While transfection substantially lowers the linkage observed between markers in normal phage crosses, linkage is observed at small map distances in transfection either by plating transfected bacteria or the progeny phage. Maps constructed from transfection crosses are identical to those of normal phage crosses, except in magnitude.—Examination of the concentration response of two marker biparental crosses, and three marker triparental crosses using transfecting DNA leads to the conclusion that at all concentrations, transfective centers are saturated with respect to the number of molecules that can be taken up. Thus, the frequency of recombinant infective centers, or recombinant progeny is independent of concentration effects. PMID:17248556

Synthesis of linear polyethylenimine derivatives for DNA transfection.

PubMed

Brissault, Blandine; Kichler, Antoine; Guis, Christine; Leborgne, Christian; Danos, Olivier; Cheradame, Hervé

2003-01-01

A series of linear polymers containing varying amounts of ethylenimine or N-propylethylenimine units were synthesized by hydrolysis and/or reduction of polyethyloxazolines. The pK(a)s of the polyamines were determined potentiometrically. Gel mobility shift assay showed that the efficiency of DNA complexation was related to the fraction of amino groups that are protonated at neutral pH. The effects of cationic charge density and molar weight of the polymers on the transfection efficiency were evaluated on HepG2 cells. The results obtained with different copolymers show that the transfection efficiency primarily depends on the fraction of ethylenimine units included in the polymer albeit the molar weight is also of importance. On the basis of the results obtained with poly(N-propylethylenimines), we also demonstrate that the high transfection efficiency of polyethylenimines does not solely rely on their capacity to capture protons which are transferred into the endo-lysosomes during acidification.

Enhanced transfection by antioxidative polymeric gene carrier that reduces polyplex-mediated cellular oxidative stress.

PubMed

Lee, Min Sang; Kim, Nak Won; Lee, Kyuri; Kim, Hongtae; Jeong, Ji Hoon

2013-06-01

To test the hypothesis in which polyplex-induced oxidative stress may affect overall transfection efficiency, an antioxidative transfection system minimizing cellular oxidative stress was designed for enhanced transfection. An amphiphilic copolymer (PEI-PLGA) was synthesized and used as a micelle-type gene carrier containing hydrophobic antioxidant, α-tocopherol. Cellular oxidative stress and the change of mitochondrial membrane potential after transfection was measured by using a fluorescent probe (H₂DCFDA) and lipophilic cationic probe (JC-1), respectively. Transfection efficiency was determined by measuring a reporter gene (luciferase) expression level. The initial transfection study with conventional PEI/plasmid DNA polyplex showed significant generation of reactive oxygen species (ROS). The PEI-PLGA copolymer successfully carried out the simultaneous delivery of α-tocopherol and plasmid DNA (PEI-PLGA/Toco/pDNA polyplex) into cells, resulting in a significant reduction in cellular ROS generation after transfection and helped to maintain the mitochondrial membrane potential (ΔΨ). In addition, the transfection efficiency was dramatically increased using the antioxidative transfection system. This work showed that oxidative stress would be one of the important factors that should be considered in designing non-viral gene carriers and suggested a possible way to reduce the carrier-mediated oxidative stress, which consequently leads to enhanced transfection.

Transfection of isolated rainbow trout, Oncorhynchus mykiss, granulosa cells through chemical transfection and electroporation at 12°C.

PubMed

Marivin, E; Mourot, B; Loyer, P; Rime, H; Bobe, J; Fostier, A

2015-09-15

Over-expression or inhibition of gene expression can be efficiently used to analyse the functions and/or regulation of target genes. Modulation of gene expression can be achieved through transfection of exogenous nucleic acids into target cells. Such techniques require the development of specific protocols to transfect cell cultures with nucleic acids. The aim of this study was to develop a method of transfection suitable for rainbow trout granulosa cells in primary culture. After the isolation of rainbow trout granulosa cells, chemical transfection of cells with a fluorescent morpholino oligonucleotide (MO) was tested using FuGENE HD at 12 °C. Electroporation was also employed to transfect these cells with either a plasmid or MO. Transfection was more efficient using electroporation (with the following settings: 1200 V/40 ms/1p) than chemical transfection, but electroporation by itself was deleterious, resulting in a decrease of the steroidogenic capacity of the cells, measured via estradiol production from its androgenic substrate. The disturbance of cell biology induced by the transfection method per se should be taken into account in data interpretation when investigating the effects of under- or over-expression of candidate genes. Copyright © 2015 Elsevier Inc. All rights reserved.

Superhydrophilic-Superhydrophobic Patterned Surfaces as High-Density Cell Microarrays: Optimization of Reverse Transfection.

PubMed

Ueda, Erica; Feng, Wenqian; Levkin, Pavel A

2016-10-01

High-density microarrays can screen thousands of genetic and chemical probes at once in a miniaturized and parallelized manner, and thus are a cost-effective alternative to microwell plates. Here, high-density cell microarrays are fabricated by creating superhydrophilic-superhydrophobic micropatterns in thin, nanoporous polymer substrates such that the superhydrophobic barriers confine both aqueous solutions and adherent cells within each superhydrophilic microspot. The superhydrophobic barriers confine and prevent the mixing of larger droplet volumes, and also control the spreading of droplets independent of the volume, minimizing the variability that arises due to different liquid and surface properties. Using a novel liposomal transfection reagent, ScreenFect A, the method of reverse cell transfection is optimized on the patterned substrates and several factors that affect transfection efficiency and cytotoxicity are identified. Higher levels of transfection are achieved on HOOC- versus NH 2 -functionalized superhydrophilic spots, as well as when gelatin and fibronectin are added to the transfection mixture, while minimizing the amount of transfection reagent improves cell viability. Almost no diffusion of the printed transfection mixtures to the neighboring microspots is detected. Thus, superhydrophilic-superhydrophobic patterned surfaces can be used as cell microarrays and for optimizing reverse cell transfection conditions before performing further cell screenings. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluation of different photosensitizers for use in photochemical gene transfection.

PubMed

Prasmickaite, L; Høgset, A; Berg, K

2001-04-01

Many potentially therapeutic macromolecules, e.g. transgenes used in gene therapy, are taken into the cells by endocytosis, and have to be liberated from endocytic vesicles in order to express a therapeutic function. To achieve this we have developed a new technology, named photochemical internalization (PCI), based on photochemical reactions inducing rupture of endocytic vesicles. The aim of this study was to clarify which properties of photosensitizers are important for obtaining the PCI effect improving gene transfection. The photochemical effect on transfection of human melanoma THX cells has been studied employing photosensitizers with different physicochemical properties and using two gene delivery vectors: the cationic polypeptide polylysine and the cationic lipid 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP). Photochemical treatment by photosensitizers that do not localize in endocytic vesicles (tetra[3-hydroxyphenyl]porphyrin and 5-aminolevulinic acid-induced protoporphyrin IX) do not stimulate transfection, irrespective of the gene delivery vector. In contrast, photosensitizers localized in endocytic vesicles stimulate polylysine-mediated transfection, and amphiphilic photosensitizers (disulfonated aluminium phthalocyanine [AlPcS2a] and meso-tetraphenylporphynes) show the strongest positive effect, inducing approximately 10-fold increase in transfection efficiency. In contrast, DOTAP-mediated transfection is inhibited by all photochemical treatments irrespective of the photosensitizer used. Neither AlPcS2a nor Photofrin affects the uptake of the transfecting DNA over the plasma membrane, therefore photochemical permeabilization of endocytic vesicles seems to be the most likely mechanism responsible for the positive PCI effect on gene transfection.

Enhanced photo-transfection efficiency of mammalian cells on graphene coated substrates

NASA Astrophysics Data System (ADS)

Mthunzi, Patience; He, Kuang; Ngcobo, Sandile; Warner, Jamie W.

2014-03-01

Literature reports graphene, an atomic-thick sheet of carbon atoms as one of the promising biocompatible scaffolds that promotes cellular proliferation in human mesenchymal stem cells. On the other hand, different mammalian cell lines including the induced pluripotent stem cells exhibited an accelerated proliferation rate when cultured on graphene or graphene oxide coated substrates. These findings provide strong motivation to explore the full capability of graphene in further pluripotent stem cell research activities as there exists an urgent requirement to preserve their therapeutic potential. This therefore calls for non-invasive procedures for handling stem cells in-vitro. For example, resent literature has shown successful laser light driven transfection in both multipotent and pluripotent stem cells. In order to explore the non-invasive nature of optical transfection alongside biocompatible qualities of graphene, in this work we investigated the impact of optically transfecting mouse embryonic stem (mES) cells plated on graphene coated sample chambers. Using Chinese Hamster Ovary cells (CHO-K1), we further studied the influence of graphene on cell viability as well as cell cytotoxicity through assessing changes in levels of mitochondrial adenosine triphosphate (ATP) activity and the release of cytosolic lactate dehydrogenase (LHD) respectively. Our results showed that compared to those treated on plain glass, CHO-K1 cells optically treated while plated on graphene coated substrates exhibited a higher production of ATP and a milder release of LDH. In addition there was enhanced photo-transfection efficiency in both CHO-K1 and mES cells irradiated on graphene sample chambers.

[EFFECT OF RECOMBINANT ADENOVIRUS-BONE MORPHOGENETIC PROTEIN 12 TRANSFECTION ON DIFFERENTIATION OF PERIPHERAL BLOOD MESENCHYMAL STEM CELLS INTO TENDON/LIGAMENT CELLS].

PubMed

Fu, Weili; Chen, Gang; Tang, Xin; Li, Qi; Ll, Jian

2015-04-01

To research the effect of recombinant adenovirus-bone morphogenetic protein 12 (Ad-BMP-12) transfection on the differentiation of peripheral blood mesenchymal stem cells (MSCs) into tendon/ligament cells. Peripheral blood MSCs were isolated from New Zealand rabbits (3-4 months old) and cultured in vitro until passage 3. The recombinant adenoviral vector system was prepared using AdEasy system, then transfected into MSCs at passage 3 (transfected group); untransfected MSCs served as control (untransfected group). The morphological characteristics and growth of transfected cells were observed under inverted phase contrast microscope. The transfection efficiency and green fluorescent protein (GFP) expression were detected by flow cytometry (FCM) and fluorescence microscopy. After cultured for 14 days in vitro, the expressions of tendon/ligament-specific markers were determined by immunohistochemistry and real-time fluorescent quantitative PCR. GFP expression could be observed in peripheral blood MSCs at 8 hours after transfection. At 24 hours after transfection, the cells had clear morphology and grew slowly under inverted phase contrast microscope and almost all expressed GFP at the same field under fluorescence microscopy. FCM analysis showed that the transfection efficiency of the transfected group was 99.57%, while it was 2.46% in the untransfected group. The immunohistochemistry showed that the expression of collagen type I gradually increased with culture time in vitro. Real-time fluorescent quantitative PCR results showed that the mRNA expressions of the tendon/ligament-specific genes (Tenomodulin, Tenascin-C, and Decorin) in the transfected group were significantly higher than those in untransfected group (0.061+/- 0.013 vs. 0.004 +/- 0.002, t = -7.700, P=0.031; 0.029 +/- 0.008 vs. 0.003 +/- 0.001, t = -5.741, P=0.020; 0.679 +/- 0.067 vs. 0.142 +/- 0.024, t = -12.998, P=0.000). Ad-BMP-12 can significantly promote differentiation of peripheral blood MSCs into

Live-cell imaging to compare the transfection and gene silencing efficiency of calcium phosphate nanoparticles and a liposomal transfection agent.

PubMed

Chernousova, S; Epple, M

2017-05-01

The processing of DNA (for transfection) and short interfering RNA (siRNA; for gene silencing), introduced into HeLa cells by triple-shell calcium phosphate nanoparticles, was followed by live-cell imaging. For comparison, the commercial liposomal transfection agent Lipofectamine was used. The cells were incubated with these delivery systems, carrying either enhanced green fluorescent protein (eGFP)-encoding DNA or siRNA against eGFP. In the latter case, HeLa cells that stably expressed eGFP were used. The expression of eGFP started after 5 h in the case of nanoparticles and after 4 h in the case of Lipofectamine. The corresponding times for gene silencing were 5 h (nanoparticles) and immediately after incubation (Lipofectamine). The expression of eGFP was notably enhanced 2-3 h after cell division (mitosis). In general, the transfection and gene silencing efficiencies of the nanoparticles were lower than those of Lipofectamime, even at a substantially higher dose (factor 20) of nucleic acids. However, the cytotoxicity of the nanoparticles was lower than that of Lipofectamine, making them suitable vectors for in vivo application.

Live-cell imaging to compare the transfection and gene silencing efficiency of calcium phosphate nanoparticles and a liposomal transfection agent

PubMed Central

Chernousova, S; Epple, M

2017-01-01

The processing of DNA (for transfection) and short interfering RNA (siRNA; for gene silencing), introduced into HeLa cells by triple-shell calcium phosphate nanoparticles, was followed by live-cell imaging. For comparison, the commercial liposomal transfection agent Lipofectamine was used. The cells were incubated with these delivery systems, carrying either enhanced green fluorescent protein (eGFP)-encoding DNA or siRNA against eGFP. In the latter case, HeLa cells that stably expressed eGFP were used. The expression of eGFP started after 5 h in the case of nanoparticles and after 4 h in the case of Lipofectamine. The corresponding times for gene silencing were 5 h (nanoparticles) and immediately after incubation (Lipofectamine). The expression of eGFP was notably enhanced 2–3 h after cell division (mitosis). In general, the transfection and gene silencing efficiencies of the nanoparticles were lower than those of Lipofectamime, even at a substantially higher dose (factor 20) of nucleic acids. However, the cytotoxicity of the nanoparticles was lower than that of Lipofectamine, making them suitable vectors for in vivo application. PMID:28218744

Transient transfection of intraerythrocytic Babesia gibsoni using elongation factor-1 alpha promoter.

PubMed

Liu, Mingming; Asada, Masahito; Cao, Shinuo; Adjou Moumouni, Paul Franck; Vudriko, Patrick; Efstratiou, Artemis; Hakimi, Hassan; Masatani, Tatsunori; Sunaga, Fujiko; Kawazu, Shin-Ichiro; Yamagishi, Junya; Xuan, Xuenan

2017-09-01

The development of gene manipulation techniques has been reported in many protozoan parasites over the past few years. However, these techniques have not yet been established for Babesia gibsoni. Here, we report for the first time, the successful transient transfection of B. gibsoni. The plasmid containing the firefly luciferase reporter gene (pBS-ELA) was transfected into B. gibsoni by an AMAXA 4D Nucleofector™ device. Transfection using program FA113 and Lonza buffer SF showed the highest luciferase expression. Twenty micrograms of plasmid produced the highest relative transfection efficiency. The fluorescent protein-expressing parasites were determined by GFP-containing plasmid (pBS-EGA) at 48 and 72h post transfection. This finding is the first step towards a stable transfection method for B. gibsoni, which may contribute to a better understanding of the biology of the parasite. Copyright © 2017 Elsevier B.V. All rights reserved.

Transfection in perfused microfluidic cell culture devices: A case study.

PubMed

Raimes, William; Rubi, Mathieu; Super, Alexandre; Marques, Marco P C; Veraitch, Farlan; Szita, Nicolas

2017-08-01

Automated microfluidic devices are a promising route towards a point-of-care autologous cell therapy. The initial steps of induced pluripotent stem cell (iPSC) derivation involve transfection and long term cell culture. Integration of these steps would help reduce the cost and footprint of micro-scale devices with applications in cell reprogramming or gene correction. Current examples of transfection integration focus on maximising efficiency rather than viable long-term culture. Here we look for whole process compatibility by integrating automated transfection with a perfused microfluidic device designed for homogeneous culture conditions. The injection process was characterised using fluorescein to establish a LabVIEW-based routine for user-defined automation. Proof-of-concept is demonstrated by chemically transfecting a GFP plasmid into mouse embryonic stem cells (mESCs). Cells transfected in the device showed an improvement in efficiency (34%, n = 3) compared with standard protocols (17.2%, n = 3). This represents a first step towards microfluidic processing systems for cell reprogramming or gene therapy.

Proteome alteration induced by hTERT transfection of human fibroblast cells.

PubMed

Mazzucchelli, Gabriel D; Gabelica, Valérie; Smargiasso, Nicolas; Fléron, Maximilien; Ashimwe, Wilson; Rosu, Frédéric; De Pauw-Gillet, Marie-Claire; Riou, Jean-François; De Pauw, Edwin

2008-04-17

Telomerase confers cellular immortality by elongating telomeres, thereby circumventing the Hayflick limit. Extended-life-span cells have been generated by transfection with the human telomerase reverse transcriptase (hTERT) gene. hTERT transfected cell lines may be of outstanding interest to monitor the effect of drugs targeting the telomerase activity. The incidence of hTERT gene transfection at the proteome level is a prerequisite to that purpose. The effect of the transfection has been studied on the proteome of human fibroblast (WI38). Cytosolic and nuclear fractions of WI38 cells, empty vector transfected WI38 (WI38-HPV) and hTERT WI38 cells were submitted to a 2D-DIGE (Two-Dimensional Differential In-Gel Electrophoresis) analysis. Only spots that had a similar abundance in WI38 and WI38-HPV, but were differentially expressed in WI38 hTERT were selected for MS identification. This method directly points to the proteins linked with the hTERT expression. Number of false positive differentially expressed proteins has been excluded by using control WI38-HPV cells. The proteome alteration induced by hTERT WI38 transfection should be taken into account in subsequent use of the cell line for anti-telomerase drugs evaluation. 2D-DIGE experiment shows that 57 spots out of 2246 are significantly differentially expressed in the cytosolic fraction due to hTERT transfection, and 38 were confidently identified. In the nuclear fraction, 44 spots out of 2172 were selected in the differential proteome analysis, and 14 were identified. The results show that, in addition to elongating telomeres, hTERT gene transfection has other physiological roles, among which an enhanced ER capacity and a potent cell protection against apoptosis. We show that the methodology reduces the complexity of the proteome analysis and highlights proteins implicated in other processes than telomere elongation. hTERT induced proteome changes suggest that telomerase expression enhances natural cell repair

Evaluation of cationic liposomes composed of an amino acid-based lipid for neuronal transfection.

PubMed

Obata, Yosuke; Ciofani, Gianni; Raffa, Vittoria; Cuschieri, Alfred; Menciassi, Arianna; Dario, Paolo; Takeoka, Shinji

2010-02-01

We investigated the ability of cationic liposomes composed of 1,5-dihexadecyl N-arginyl-L-glutamate (Arg-Glu2C(16)) to carry nucleic acids into neuronal cells. Such liposomes have been shown to have a remarkable capacity for transfecting immortalized cell lines. Lipoplexes between the Arg-Glu2C(16) liposomes and plasmid DNA encoding green fluorescent protein (GFP) were analyzed in terms of lipoplex formation, intracellular DNA trafficking, transfection efficiency, and cytotoxicity in neuronal SH-SY5Y cells. A maximum number of cells expressing GFP was obtained with lipoplexes at a lipid-to-DNA ratio of 15. With these lipoplexes, 16% of the cells were GFP-positive, which was approximately fourfold higher than the level obtained with a commercially available transfection reagent, Lipofectamine 2000. Furthermore, as a result of the low cytotoxicity of the Arg-Glu2C(16) lipoplexes, the proportion of GFP-positive cells could be increased to 25% by increasing the concentration of lipoplexes that was applied to the cells. We have demonstrated that Arg-Glu2C(16), as a model cationic amino acid-based lipid, has a high capability as a gene carrier, even for neuronal transfection. In this study, specific cationic liposomes were characterized as nucleic acid transfection agents for neuronal cells. A fourfold higher transfection rate with low cytotoxicity was reported compared to Lipofectamine 2000, a commercial reagent. The authors conclude that the studied cationic liposomes have a high capability as a gene carrier for neuronal transfection. This may become clinically significant in future gene therapy efforts of neuronal diseases. Copyright 2010 Elsevier Inc. All rights reserved.

Transient transfection of mammalian cells using a violet diode laser

NASA Astrophysics Data System (ADS)

Torres-Mapa, Maria Leilani; Angus, Liselotte; Ploschner, Martin; Dholakia, Kishan; Gunn-Moore, Frank J.

2010-07-01

We demonstrate the first use of the violet diode laser for transient mammalian cell transfection. In contrast to previous studies, which showed the generation of stable cell lines over a few weeks, we develop a methodology to transiently transfect cells with an efficiency of up to ~40%. Chinese hamster ovary (CHO-K1) and human embryonic kidney (HEK293) cells are exposed to a tightly focused 405-nm laser in the presence of plasmid DNA encoding for a mitochondrial targeted red fluorescent protein. We report transfection efficiencies as a function of laser power and exposure time for our system. We also show, for the first time, that a continuous wave laser source can be successfully applied to selective gene silencing experiments using small interfering RNA. This work is a major step towards an inexpensive and portable phototransfection system.

Calcium phosphate transfection of primary hippocampal neurons.

PubMed

Sun, Miao; Bernard, Laura P; Dibona, Victoria L; Wu, Qian; Zhang, Huaye

2013-11-12

Calcium phosphate precipitation is a convenient and economical method for transfection of cultured cells. With optimization, it is possible to use this method on hard-to-transfect cells like primary neurons. Here we describe our detailed protocol for calcium phosphate transfection of hippocampal neurons cocultured with astroglial cells.

Antitumoral effect of IL-12 gene transfected via liposomes into B16F0 cells.

PubMed

Speroni, Lucía; Gasparri, Julieta; de los A Bustuoabad, Victoria; Chiaramoni, Nadia S; Smagur, Andrzej; Szala, Stanisław; Taira, María C; del V Alonso, Silvia

2009-01-01

Murine melanoma B16F0 cells were transfected with SA:DPPC:DOPE (2:1:1 molar ratio) liposomes associated with a plasmid encoding murine IL-12. Stearylamine, a cationic lipid, showed a greater transfection efficiency compared to DOTAP-containing liposomes. The lipid:DNA ratio was 2:1 (w/w). Control groups were mock transfected or transfected with an empty plasmid (pNeo). pNeo or IL-12 transfected cells and controls were inoculated intradermically into the dorsal region of the foot or the lateral flank of C57BL6 mice. Results showed that IL-12 expression had a marked effect on in vivo growth of B16 melanoma tumors developed in both anatomic sites, significantly retarding their growth and prolonging host survival.

Calcium Phosphate Transfection of Primary Hippocampal Neurons

PubMed Central

DiBona, Victoria L.; Wu, Qian; Zhang, Huaye

2013-01-01

Calcium phosphate precipitation is a convenient and economical method for transfection of cultured cells. With optimization, it is possible to use this method on hard-to-transfect cells like primary neurons. Here we describe our detailed protocol for calcium phosphate transfection of hippocampal neurons cocultured with astroglial cells. PMID:24300106

[EFFECT OF Akt1 GENE TRANSFECTION ON HYPOXIA TOLERANCE OF BONE MARROW MESENCHYMAL STEM CELLS].

PubMed

Yu, Fengxu; Chen, Yongen; Chen, Feng; Xia, Jiyi; Liu, Hongduan; Fu, Yong; Li, Miaoling; Liao, Bin

2016-04-01

. MTT assay showed tat absorbance (A) values of groups B and C were significantly higher than those of groups B1 and C1 at each time point (P < 0.05); the A value of group B was significantly lower than that of group C at each time point (P < 0.05). The A value of group B1 was significantly lower than that of group Cl at 6, 9, and 12 hours after hypoxia intervention (P < 0.05). Western blot results showed that the Caspase-3 expression of group C1 significantly reduced when compared with group B1 at each time point (P < 0.05). Akt1 gene transfection mediated by recombinant LVs could significantly improve hypoxia tolerance of BMSCs by inhibiting the apoptosis, which could provide new ideas for improving the effectiveness of stem cells transplantation.

Poly(β-Amino Ester)-Nanoparticle Mediated Transfection of Retinal Pigment Epithelial Cells In Vitro and In Vivo

PubMed Central

Bhutto, Imran; Handa, James T.; Green, Jordan J.

2012-01-01

A variety of genetic diseases in the retina, including retinitis pigmentosa and leber congenital amaurosis, might be excellent targets for gene delivery as treatment. A major challenge in non-viral gene delivery remains finding a safe and effective delivery system. Poly(beta-amino ester)s (PBAEs) have shown great potential as gene delivery reagents because they are easily synthesized and they transfect a wide variety of cell types with high efficacy in vitro. We synthesized a combinatorial library of PBAEs and evaluated them for transfection efficacy and toxicity in retinal pigment epithelial (ARPE-19) cells to identify lead polymer structures and transfection formulations. Our optimal polymer (B5-S5-E7 at 60 w/w polymer∶DNA ratio) transfected ARPE-19 cells with 44±5% transfection efficacy, significantly higher than with optimized formulations of leading commercially available reagents Lipofectamine 2000 (26±7%) and X-tremeGENE HP DNA (22±6%); (p<0.001 for both). Ten formulations exceeded 30% transfection efficacy. This high non-viral efficacy was achieved with comparable cytotoxicity (23±6%) to controls; optimized formulations of Lipofectamine 2000 and X-tremeGENE HP DNA showed 15±3% and 32±9% toxicity respectively (p>0.05 for both). Our optimal polymer was also significantly better than a gold standard polymeric transfection reagent, branched 25 kDa polyethyleneimine (PEI), which achieved only 8±1% transfection efficacy with 25±6% cytotoxicity. Subretinal injections using lyophilized GFP-PBAE nanoparticles resulted in 1.1±1×103-fold and 1.5±0.7×103-fold increased GFP expression in the retinal pigment epithelium (RPE)/choroid and neural retina respectively, compared to injection of DNA alone (p = 0.003 for RPE/choroid, p<0.001 for neural retina). The successful transfection of the RPE in vivo suggests that these nanoparticles could be used to study a number of genetic diseases in the laboratory with the potential to treat debilitating eye

Fast targeted gene transfection and optogenetic modification of single neurons using femtosecond laser irradiation.

PubMed

Antkowiak, Maciej; Torres-Mapa, Maria Leilani; Witts, Emily C; Miles, Gareth B; Dholakia, Kishan; Gunn-Moore, Frank J

2013-11-21

A prevailing problem in neuroscience is the fast and targeted delivery of DNA into selected neurons. The development of an appropriate methodology would enable the transfection of multiple genes into the same cell or different genes into different neighboring cells as well as rapid cell selective functionalization of neurons. Here, we show that optimized femtosecond optical transfection fulfills these requirements. We also demonstrate successful optical transfection of channelrhodopsin-2 in single selected neurons. We extend the functionality of this technique for wider uptake by neuroscientists by using fast three-dimensional laser beam steering enabling an image-guided "point-and-transfect" user-friendly transfection of selected cells. A sub-second transfection timescale per cell makes this method more rapid by at least two orders of magnitude when compared to alternative single-cell transfection techniques. This novel technology provides the ability to carry out large-scale cell selective genetic studies on neuronal ensembles and perform rapid genetic programming of neural circuits.

[Optimizing condition for oligofectamine-mediated SP1 decoy oligodeoxynucleotides transfection into SV-40-PED cells].

PubMed

Huang, Yabing; Xu, Jing; Chen, Song

2007-08-01

To determine the optimizing parameters in transfecting the SV-40-PED cells mediated by oligofectamine. With a change of Decoy oligodeoxynucleotides (ODNs)/oligofectamine in ratio and the transfection time, the uptake rate and the mean fluorescence intensity of SP1 ODNs in the SV-40-PED cells were measured by flow cytometry to evaluate the transfection efficiencies. 4 microl oligofectamine with different concentrations of ODNs(2.5, 5.0, 7.5, 10.0 and 12.5 microl) were put into 100 microl of DMEM without serum and antibiotics. the (SV-40-PED) cells were transfected after 20 min at room temperature. the final concentration of SP1 decay ODNs were 50,100, 150, 200 and 250 nmol/L. Transfection effieiency was detected at 26 h after transfection. The intracellular distribution of SP1 ODNs was determined with a fluorescence microscope. The lactate dehydrogenase (LDH) activity in the supernatant was measured to assess the cytotoxicity. The uptake of SP1 ODNs into the SV-40-PED cells was significantly improved by oligofectamine. The cell appearance did not change much in the groups of 50, 100 and 150 nmol/L. In the groups of 200 and 250 nmol/L, the cell reverted after being shrinked and altered to round. At 26 h after the transfection, there was no marked change in the cell form at the concentration of 250 nmol/L. There was floatation at 48 and 72 h after the transfection. Under the fluorescence microscope, we observed fluorescent materials distributed in the cell nucleus in the successfully-transferred groups. We could see the nucleoli clearly in the groups of 200 nmol/L and 250 nmol/L. There was a stronger fluorescence intensity with a higher concentration and the fluorescent materials gathered at the cell nucleus. At the final concentration of 250 nmol/L, the LDH level was 137.12+/-3.92 U/L in the 72-h group, which was significantly higher those that in the 26-h group (49.61+/-17.13 U/L) and the 48-h group (120.26 +/- 8.42 U/L) (P<0.01). At 26 h after the transfection

Spatial and Temporal Control of Cavitation Allows High In Vitro Transfection Efficiency in the Absence of Transfection Reagents or Contrast Agents.

PubMed

Chettab, Kamel; Roux, Stéphanie; Mathé, Doriane; Cros-Perrial, Emeline; Lafond, Maxime; Lafon, Cyril; Dumontet, Charles; Mestas, Jean-Louis

2015-01-01

Sonoporation using low-frequency high-pressure ultrasound (US) is a non-viral approach for in vitro and in vivo gene delivery. In this study, we developed a new sonoporation device designed for spatial and temporal control of ultrasound cavitation. The regulation system incorporated in the device allowed a real-time control of the cavitation level during sonoporation. This device was evaluated for the in vitro transfection efficiency of a plasmid coding for Green Fluorescent Protein (pEGFP-C1) in adherent and non-adherent cell lines. The transfection efficiency of the device was compared to those observed with lipofection and nucleofection methods. In both adherent and non-adherent cell lines, the sonoporation device allowed high rate of transfection of pEGFP-C1 (40-80%), as determined by flow cytometry analysis of GFP expression, along with a low rate of mortality assessed by propidium iodide staining. The transfection efficiency and toxicity of sonoporation on the non-adherent cell lines Jurkat and K562 were similar to those of nucleofection, while these two cell lines were resistant to transfection by lipofection. Moreover, sonoporation was used to produce three stably transfected human lymphoma and leukemia lines. Significant transfection efficiency was also observed in two fresh samples of human acute myeloid leukemia cells. In conclusion, we developed a user-friendly and cost-effective ultrasound device, well adapted for routine in vitro high-yield transfection experiments and which does not require the use of any transfection reagent or gas micro-bubbles.

Uptake of DNA by cancer cells without a transfection reagent.

PubMed

Kong, Yanping; Zhang, Xianbo; Zhao, Yongliang; Xue, Yanfang; Zhang, Ye

2017-01-21

Cancer cells exhibit elevated levels of glucose uptake and may obtain pre-formed, diet-derived fatty acids from the bloodstream to boost their rapid growth; they may also use nucleic acid from their microenvironment. The study of processing nucleic acid by cancer cells will help improve the understanding of the metabolism of cancer. DNA is commonly packaged into a viral or lipid particle to be transferred into cells; this process is called transfection in laboratory. Cancer cells are known for having gene mutations and the evolving ability of endocytosis. Their uptake of DNAs might be different from normal cells; they may take in DNAs directly from the environment. In this report, we studied the uptake of DNAs in cancer cells without a transfection reagent. A group of DNA fragments were prepared with PCR and labeled with isotope phosphorous-32 to test their uptake by Huh 7 (liver cancer) and THLE3 (normal liver cells) after incubation overnight by counting radioactivity of the cells' genomic DNA. Multiple cell lines including breast cancer and lung cancer were tested with the same method. DNA molecules were also labeled with fluorescence to test the location in the cells using a kit of "label it fluorescence in situ hybridization (FISH)" from Mirus (USA). The data demonstrated that hepatocellular carcinoma cells possess the ability to take in large DNA fragments directly without a transfection reagent whereas normal liver cells cannot. Huh7 and MDA-MB231 cells displayed a significantly higher Rhodamine density in the cytoplasmic phagosomes and this suggests that the mechanism of uptake of large DNA by cancer cells is likely endocytosis. The efficacy of uptake is related to the DNA's size. Some cell lines of lung cancer and breast cancer also showed similar uptake of DNA. In the present study, we have revealed the evidence that some cancer cells, but not nontumorigenic cells, can take DNA fragments directly from the environment without the aid of the transfecting

[The effect of retrovirus-mediated hTRT transfection into cultured oral keratinocytes].

PubMed

Huang, Ji-yan; Liu, Wei; Zhou, Zeng-tong; Zhou, Hai-wen

2014-06-01

Human telomerase reverse transcriptase (hTRT) was transfected into cultured oral keratinocytes (OKC) mediated by pBABE-tert recombined retrovirus to investigate the effect on OKC lifespan. pBABE-tert recombined retrovirus loaded with hTRT gene was amplified by transfected PT67 cells, and then transfected into cultured OKC in vitro. The positive clones of OKC were separated by puromycin and subcultured. Telomerase activity was analyzed by telomerase PCR-ELISA and PCR-PAGE. The hTRT positive clones of OKC showed telomerase expression, with extending lifespan to 8-9 passages. The hTRT transfected OKC can prolong doubly lifespan but not be immortalized, which indicates that cellular immortality mechanism is complicated and multi-controled. Telomerase activity is the key for cell immortalization but not the only impact factor.

[Study of the antitumor activity of alveolar macrophages after transfected human INF-γ gene].

PubMed

Zhou, Fengli; Bi, Xiaogang; Zhang, Tiantuo; Huang, Jing

2011-05-01

Alveolar macrophages (AMs) activated have the antitumor activity. The interferon-γ (INF-γ) is one of the stimulating factors. INF-γ can enhance the immune function of AMs in vitro. The aim of this study is to investigate the effect of human INF-γ gene on the antitumor activity of AMs when transfected into the alveolar macrophages (AMs) from the patients with lung cancer in vitro. AMs obtained by brochoalveolar lavage were separated and transfected by INF-γ gene. RT-PCR and ELISA were applied to determine whether the transfection was successful. The levels of tumor necrosis factor α (TNF-α), nitric oxide (NO) and interleukin-1 (IL-1) produced by AMs and the killing activity of AMs against L1210 cells was detected respectively. Both RT-PCR and ELISA demonstrated that human INF-γ gene had been successfully transfected into AMs. When transfected by human INF-γ gene, the levels of TNF-α, NO and IL-1 produced by AMs from the patients with lung cancer and the killing activity of AMs against L1210 cells were significantly higher than those of the control groups. Human INF-γ gene can enhance the antitumor activity of AMs when transfected into AMs from the patients with lung cancer.

The Synergistic Effect between Electrical and Chemical Factors in Plasma Gene/Molecule-Transfection

NASA Astrophysics Data System (ADS)

Jinno, Masafumi

2016-09-01

This study has been done to know what kind of factors in plasma and processes on cells promote plasma gene/molecule transfection. We have discovered a new plasma source using a microcapillary electrode which enables high transfection efficiency and high cell survivability simultaneously. However, the mechanism of the transfection by plasma was not clear. To clarify the transfection mechanisms by micro plasma, we focused on the effects of electrical (current, charge, field, etc.) and chemical (radicals, RONS, etc.) factors generated by the micro plasma and evaluated the contribution weight of three groups of the effects and processes, i.e. electrical, chemical and biochemical ones. At first, the necessity of the electrical factors was estimated by the laser produced plasma (LPP). Mouse L-929 fibroblast cell was cultured on a 96-well plate or 12-well micro slide chamber. Plasmids pCX-EGFP in Tris-EDTA buffer was dropped on the cells and they were exposed to the capillary discharge plasma (CDP) or the LPP. In the case of the CDP, the plasma was generated between the tip of the capillary electrode and the cells so that both electrical and chemical factors were supplied to the cells. In this setup, about 20% of average transfection efficiency was obtained. In the case of the LPP, the plasma was generated apart from the cells so that electrical factors were not supplied to the cells. In this setup, no transfection was observed. These results show that the electrical factors are necessary for the plasma gene transfection. Next, the necessity of the chemical factors was estimated the effect of catalase to remove H2O2 in CDP. The transfection efficiency decreased to 0.4 by scavenging H2O2 with catalase. However, only the solution of H2O2 caused no gene transfection in cells. These results shows that H2O2 is important species to cause gene/molecule transfection but still needs a synergistic effect with electrical or other chemical factors. This work was partly supported by

Dual-degradable disulfide-containing PEI–Pluronic/DNA polyplexes: transfection efficiency and balancing protection and DNA release

PubMed Central

Zhang, Lifen; Chen, Zhenzhen; Li, Yanfeng

2013-01-01

Polymeric gene-delivery vectors to achieve lack of toxicity and a balance between protection and DNA release remains a formidable challenge. Incorporating intracellular environment-responsive degradable bonds is an appreciable step toward developing safer transfection agents. In this study, novel, dual-degradable polycation copolymers (Pluronic-diacrylate [PA]–polyethyleneimine [PEI]–SS) were synthesized through the addition of low molecular weight (800 Da) PEI cross-linked with SS (PEI-SS) to PA. Three PA-PEI-SS copolymers (PA-PEI-SS1, 2, and 3) with different PEI-SS to Pluronic molar ratios were investigated and found to strongly condense plasmid DNA into positively charged nanoparticles with an average particle size of approximately 200 nm and to possess higher stability against DNase I digestion and sodium heparin. Disulfide and ester bonds of the copolymers were susceptible to intracellular redox conditions. In vitro experiments demonstrated that the PA-PEI-SS copolymers had significantly lower cytotoxicity and higher transfection efficiency in both BGC-823 and 293T cell lines than the controls of degradable PEI-SS and nondegradable 25 kDa PEI. Transfection activity was influenced by the PEI-SS content in the polymers and PA-PEI-SS1 showed the highest efficiency of the three copolymers. These studies suggest that these dual-degradable copolymers could be used as potential biocompatible gene delivery carriers. PMID:24109182

Effects of BDNF-Transfected BMSCs on Neural Functional Recovery and Synaptophysin Expression in Rats with Cerebral Infarction.

PubMed

Zhang, Yongming; Qiu, Binghui; Wang, Jinbiao; Yao, Yi; Wang, Chunlin; Liu, Jiachuan

2017-07-01

The purpose of this study was to investigate the effects of brain-derived neurotrophic factor (BDNF)-transfected bone marrow mesenchymal stem cells (BMSCs) on neural functional recovery and synaptophysin expression in rats with cerebral infarction (CI). A total of 120 healthy Sprague Dawley rats were randomly divided into sham group, control group, and model group. Craniotomy was conducted and neurological function defect scoring was used to verify the model. BDNF containing recombinant plasmid was transfected into rat BMSCs, which was verified by flow cytometry and Western Blot. After injection of the transfected BMSCs, neural functional recovery of the CI rats and synaptophysin expression were measured. After the CI rat model was established, magnetic resonance (MR) imaging, 2, 3, 5- triphenyl tetrazolium chloride (TTC) staining, and the neurological function defect scoring determined the success of the model. CD34 (-), CD45 (-), CD29 (+), and CD90 (+) cells detected showed that the obtained BMSCs have high purity. BDNF protein was highly expressed in the BMSCs successfully transfected with the recombinant plasmid. Balance beam walking score, rotating bar walking score, and screen test score were significantly lower, while synaptophysin expression was higher in the BDNF model group than those in the non-BDNF model group and sham group with time extension. BDNF can increase synaptic plasticity and neurogenesis and have a promotional role in neural functional recovery and synaptophysin expression in rats with CI. BDNF-transfected BMSCs may therefore have better treatment efficacy for CI clinically.

Fast targeted gene transfection and optogenetic modification of single neurons using femtosecond laser irradiation

PubMed Central

Antkowiak, Maciej; Torres-Mapa, Maria Leilani; Witts, Emily C.; Miles, Gareth B.; Dholakia, Kishan; Gunn-Moore, Frank J.

2013-01-01

A prevailing problem in neuroscience is the fast and targeted delivery of DNA into selected neurons. The development of an appropriate methodology would enable the transfection of multiple genes into the same cell or different genes into different neighboring cells as well as rapid cell selective functionalization of neurons. Here, we show that optimized femtosecond optical transfection fulfills these requirements. We also demonstrate successful optical transfection of channelrhodopsin-2 in single selected neurons. We extend the functionality of this technique for wider uptake by neuroscientists by using fast three-dimensional laser beam steering enabling an image-guided “point-and-transfect” user-friendly transfection of selected cells. A sub-second transfection timescale per cell makes this method more rapid by at least two orders of magnitude when compared to alternative single-cell transfection techniques. This novel technology provides the ability to carry out large-scale cell selective genetic studies on neuronal ensembles and perform rapid genetic programming of neural circuits. PMID:24257461

Enhancement and optimization of plasmid expression in femtosecond optical transfection.

PubMed

Praveen, Bavishna B; Stevenson, David J; Antkowiak, Maciej; Dholakia, Kishan; Gunn-Moore, Frank J

2011-04-01

Cell transfection using femtosecond lasers is gaining importance for its proven ability to achieve selective transfection in a sterile and relatively non-invasive manner. However, the net efficiency of this technique is limited due to a number of factors that ultimately makes it difficult to be used as a viable and widely used technique. We report here a method to achieve significant enhancement in the efficiency of femtosecond optical transfection. The transfection procedure is modified by incorporating a suitable synthetic peptide containing nuclear localization and DNA binding sequences, assisting DNA import into the nucleus. We achieved a 3-fold enhancement in the transfection efficiency for adherent Chinese Hamster Ovary (CHO-K1) cells with this modified protocol. Further, in the presence of this biochemical reagent, we were able to reduce the required plasmid concentration by ~70% without compromising the transfection efficiency. Also, we report for the first time the successful photo-transfection of recently trypsinised cells with significantly high transfection efficiency when transfected with modified plasmid. This paves the way for the development of high throughput microfluidic optical transfection devices. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The effect of environmental pH on polymeric transfection efficiency.

PubMed

Kang, Han Chang; Samsonova, Olga; Kang, Sun-Woong; Bae, You Han

2012-02-01

Although polymers, polyplexes, and cells are exposed to various extracellular and intracellular pH environments during polyplex preparation and polymeric transfection, the impact of environmental pH on polymeric transfection has not yet been investigated. This study aims to understand the influence of environmental pH on polymeric transfection by modulating the pH of the transfection medium or the culture medium. Changes in the extracellular pH affected polymeric transfection by way of complex factors such as pH-induced changes in polymer characteristics (e.g., proton buffering capacity and ionization), polyplex characteristics (e.g., size, surface charge, and decomplexation), and cellular characteristics (e.g., cellular uptake, cell cycle phases, and intracellular pH environment). Notably, acidic medium delayed endocytosis, endosomal acidification, cytosolic release, and decomplexation of polyplexes, thereby negatively affecting gene expression. However, acidic medium inhibited mitosis and reduced dilution of gene expression, resulting in increased transfection efficiency. Compared to pH 7.4 medium, acidic transfection medium reduced gene expression 1.6-7.7-fold whereas acidic culture medium enhanced transfection efficiency 2.1-2.6-fold. Polymeric transfection was affected more by the culture medium than by the transfection medium. Understanding the effects of extracellular pH during polymeric transfection may stimulate new strategies for determining effective and safe polymeric gene carriers. Copyright © 2011 Elsevier Ltd. All rights reserved.

Prolonging the expression duration of ultrasound-mediated gene transfection using PEI nanoparticles.

PubMed

Lee, Jyun-Lin; Lo, Chia-Wen; Ka, Shuk-Man; Chen, Ann; Chen, Wen-Shiang

2012-05-30

Ultrasound (US) irradiation has been found to facilitate the inward transport of genetic materials across cell membranes (sonoporation). However, its transfection efficiency is generally low, and the expression duration of transfected gene is short. Polyethylenimine (PEI), a cationic polymer, has been shown to aggregate plasmid DNA and facilitate its internalization. The purpose of this study is to determine whether PEI can also prolong the expression duration after US-mediated transfection. A mixture of pCMViLUC and 22-kDa linear PEI was transfected to cultured cells or mouse muscle by exposure to 1-MHz pulsed US. The duration of expression was assessed periodically following US treatment. As expected, strong expression of luciferase could be found 30days after the treatment of DNA-PEI complex with US exposure, both in vitro and in vivo. However, without US, only very low transfection level could be obtained in vivo. The DNA/PEI complex showed protective effect against digestion of DNase I enzymes as compared with groups without PEI or to which PEI was added following the mixing of plasmid DNA with DNase I. PEI enhanced the US transfection efficiency by increasing both the intracellular uptake of plasmid DNA and the percentage of transfected cells. Most of the DNA uptake occurred at 3h after US exposure, suggesting that endocytosis took place. Moreover, the PEI-facilitated US gene transfection depended on the ratio of PEI and DNA (N/P ratio), which was different for in-vitro and in-vivo conditions. This system could be applied in future human gene therapies. Copyright © 2012 Elsevier B.V. All rights reserved.

Inner Ear Gene Transfection in Neonatal Mice Using Adeno-Associated Viral Vector: A Comparison of Two Approaches

PubMed Central

Xia, Li; Yin, Shankai; Wang, Jian

2012-01-01

Local gene transfection is a promising technique for the prevention and/or correction of inner ear diseases, particularly those resulting from genetic defects. Adeno-associated virus (AAV) is an ideal viral vector for inner ear gene transfection because of its safety, stability, long-lasting expression, and its high tropism for many different cell types. Recently, a new generation of AAV vectors with a tyrosine mutation (mut-AAV) has demonstrated significant improvement in transfection efficiency. A method for inner ear gene transfection via the intact round window membrane (RWM) has been developed in our laboratory. This method has not been tested in neonatal mice, an important species for the study of inherited hearing loss. Following a preliminary study to optimize the experimental protocol in order to reduce mortality, the present study investigated inner ear gene transfection in mice at postnatal day 7. We compared transfection efficiency, the safety of the scala tympani injection via RWM puncture, and the trans-RWM diffusion following partial digestion with an enzyme technique. The results revealed that approximately 47% of inner hair cells (IHCs) and 17% of outer hair cells (OHCs) were transfected via the trans-RWM approach. Transfection efficiency via RWM puncture (58% and 19% for IHCs and OHCs, respectively) was slightly higher, but the difference was not significant. PMID:22912830

Enhancing magnetic nanoparticle-based DNA transfection: Intracellular-active cassette features

NASA Astrophysics Data System (ADS)

Vernon, Matthew Martin

Efficient plasmid DNA transfection of embryonic stem cells, mesenchymal stem cells, neural cell lines and the majority of primary cell lines is a current challenge in gene therapy research. Magnetic nanoparticle-based DNA transfection is a gene vectoring technique that is promising because it is capable of outperforming most other non-viral transfection methods in terms of both transfection efficiency and cell viability. The nature of the DNA vector implemented depends on the target cell phenotype, where the particle surface chemistry and DNA binding/unbinding kinetics of the DNA carrier molecule play a critical role in the many steps required for successful gene transfection. Accordingly, Neuromag, an iron oxide/polymer nanoparticle optimized for transfection of neural phenotypes, outperforms many other nanoparticles and lipidbased DNA carriers. Up to now, improvements to nanomagnetic transfection techniques have focused mostly on particle functionalization and transfection parameter optimization (cell confluence, growth media, serum starvation, magnet oscillation parameters, etc.). None of these parameters are capable of assisting the nuclear translocation of delivered plasmid DNA once the particle-DNA complex is released from the endosome and dissociates in the cell's cytoplasm. In this study, incorporation of a DNA targeting sequence (DTS) feature in the transfecting plasmid DNA confers improved nuclear translocation, demonstrating significant improvement in nanomagnetic transfection efficiency in differentiated SH-SY5Y neuroblastoma cells. Other parameters, such as days in vitro, are also found to play a role and represent potential targets for further optimization.

Intranuclear DNA release is a determinant of transfection activity for a non-viral vector: biocleavable polyrotaxane as a supramolecularly dissociative condenser for efficient intranuclear DNA release.

PubMed

Yamada, Yuma; Nomura, Taku; Harashima, Hideyoshi; Yamashita, Atsushi; Katoono, Ryo; Yui, Nobuhiko

2010-01-01

It has been believed that nuclear gene delivery is the most important process for gene expression, and various non-viral vectors are currently being developed with this assumption. However, some of our earlier studies revealed a surprising difference in transfection activity between viral and non-viral vectors: this difference is largely due to the result of the intranuclear disposition of DNA rather than its delivery to the nucleus (Hama S. et al. (2006), Quantitative comparison of intracellular trafficking and nuclear transcription between adenoviral and lipoplex systems. Mol. Ther., 13, 786-794). Here, we report on some direct evidence that demonstrates the importance of the release of intranuclear DNA on transfection activity. The data show that transfection activity can be substantially enhanced by integrating a multifunctional envelope-type nano device (MEND) and a biocleavable polyrotaxane (DMAE-SS-PRX) as an artificial condenser. Our integration system showed significantly higher transfection activity compared to conventional gene delivery system. Moreover, this system provides a strong support for our hypothesis that intranuclear DNA disposition plays a critical role in gene expression for non-viral vectors.

Spontaneous gene transfection of human bone cells using 3D mineralized alginate-chitosan macrocapsules.

PubMed

Green, David W; Kim, Eun-Jung; Jung, Han-Sung

2015-09-01

The effectiveness of nonviral gene therapy remains uncertain because of low transfection efficiencies and high toxicities compared with viral-based strategies. We describe a simple system for transient transfection of continuous human cell lines, with low toxicity, using mineral-coated chitosan and alginate capsules. As proof-of-concept, we demonstrate transfection of Saos-2 and MG63 human osteosarcoma continuous cell lines with gfp, LacZ reporter genes, and a Sox-9 carrying plasmid, to illustrate expression of a functional gene with therapeutic relevance. We show that continuous cell lines transfect with significant efficiency of up to 65% possibly through the interplay between chitosan and DNA complexation and calcium/phosphate-induced translocation into cells entrapped within the 3D polysaccharide based environment, as evidenced by an absence of transfection in unmineralized and chitosan-free capsules. We demonstrated that our transfection system was equally effective at transfection of primary human bone marrow stromal cells. To illustrate, the Sox-9, DNA plasmid was spontaneously expressed in primary human bone marrow stromal cells at 7 days with up to 90% efficiency in two repeats. Mineralized polysaccharide macrocapsules are gene delivery vehicles with a number of biological and practical advantages. They are highly efficient at self-transfecting primary bone cells, with programmable spatial and temporal delivery prospects, premineralized bone-like environments, and have no cytotoxic effects, as compared with many other nonviral systems. © 2015 Wiley Periodicals, Inc.

Cholesterol-conjugated supramolecular assemblies of low generations polyamidoamine dendrimers for enhanced EGFP plasmid DNA transfection

NASA Astrophysics Data System (ADS)

Golkar, Nasim; Samani, Soliman Mohammadi; Tamaddon, Ali Mohammad

2016-05-01

Aimed to prepare an enhanced gene delivery system with low cytotoxicity and high transfection efficiency, various cholesterol-conjugated derivates of low generation polyamidoamine (PAMAM) dendrimers were prepared. The conjugates were characterized by TNBS assay, FTIR, and 1H-NMR spectroscopy. Self-assembly of the dendrimer conjugates (G1-Chol, G2-Chol, and G3-Chol) was investigated by pyrene assay. Following formation of the complexes between enhanced green fluorescence protein plasmid and the dendrimer conjugates at various N (primary amine)/P (phosphate) mole ratios, plasmid condensation, biologic stability, cytotoxicity, and protein expression were investigated. The conjugates self-assembled into micellar dispersions with the critical micelle concentration values (<50 µg/ml) depending on the dendrimer generation and cholesterol/amine mole ratio. Cholesterol conjugation resulted in higher resistance of the condensed plasmid DNA in a competition assay with heparin sulfate. Also, the transfection efficiency was determined higher for the cholesterol conjugates than unmodified dendrimers in HepG2 cells, showing the highest for G2-Chol at 40 % degree of cholesterol modification (G2-Chol40 %) among various dendrimer generations. Interestingly, such conjugate showed a complete protection of plasmid against serum nucleases. Our results confirmed that the cholesterol conjugation to PAMAM dendrimers of low generations bearing little cytotoxicity improves their several physicochemical and biological characteristics required for an enhanced delivery of plasmid DNA into cells.

Intracellular pathways and nuclear localization signal peptide-mediated gene transfection by cationic polymeric nanovectors.

PubMed

Hu, Qinglian; Wang, Jinlei; Shen, Jie; Liu, Min; Jin, Xue; Tang, Guping; Chu, Paul K

2012-02-01

Polyethylenimine (PEI) - based polymers are promising cationic nanovectors. A good understanding of the mechanism by which cationic polymers/DNA complexes are internalized and delivered to nuclei helps to identify which transport steps may be manipulated in order to improve the transfection efficiency. In this work, cell internalization and trafficking of PEI-CyD (PC) composed of β-cyclodextrin (β-CyD) and polyethylenimine (PEI, Mw 600) are studied. The results show that the PC transfected DNA is internalized by binding membrane-associated proteoglycans. The endocytic pathway of the PC particles is caveolae- and clathrin-dependent with both pathways converging to the lysosome. The intracellular fate of the PC provides visual evidence that it can escape from the lysosome. Lysosomal inhibition with chloroquine has no effect on PC mediated transfection implying that blocking the lysosomal traffic does not improve transfection. To improve the nuclear delivery of PC transfected DNA, nuclear localization signal (NLS) peptides are chosen to conjugate and combine with the PC. Compared to PC/pDNA, PC-NLS/pDNA, and PC/pDNA/NLS can effectively improve gene transfection in dividing and non-dividing cells. Copyright © 2011 Elsevier Ltd. All rights reserved.

pEGFP transfection into murine skeletal muscle by electrosonoporation

NASA Astrophysics Data System (ADS)

Tamošiūnas, Mindaugas; Jakovels, Dainis; Rubins, Uldis; Kadikis, Roberts; Petrovska, Ramona; Šatkauskas, Saulius

2017-12-01

In this study, we aimed to determine whether the combination of electroporation (EP) and ultrasound (US) waves (sonoporation) can affect the plasmid DNA transfection to mice tibialis cranialis muscle. Multispectral imaging technique combined with fluorescence spectroscopy point measurements has been used for the transcutaneous detection of enhanced green fluorescent protein (EGFP) fluorescence, providing information on location and duration of EGFP expression. We found that electrosonoporation, commonly enhancing pDNA transfection in vitro, had no positive effect on EGFP transfection efficiency increase in vivo with respect to electroporation alone. We presume that this may be associated with decreased viability of transfected fibers.

Optical transfection using an endoscope-like system.

PubMed

Ma, Nan; Gunn-Moore, Frank; Dholakia, Kishan

2011-02-01

Optical transfection is a powerful method for targeted delivery of therapeutic agents to biological cells. A tightly focused pulsed laser beam may transiently change the permeability of a cell membrane to facilitate the delivery of foreign genetic material into cells. We report the first realization of an endoscope-like integrated system for optical transfection. An imaging fiber (coherent optical fiber bundle) with ∼ 6000 cores (pixels) embedded in a fiber cladding of ∼ 300 μm in diameter, produces an image circle (area) of ∼ 270 μm diam. This imaging fiber, with an ordered axicon lens array chemically etched at its exit face, is used for the delivery of a femtosecond laser to the cell membrane for optical transfection along with subcellular resolution imaging. A microcapillary-based microfluidic system for localized drug delivery was also combined in this miniature, flexible system. Using this novel system, a plasmid transfection efficiency up to ∼ 72% was obtained for CHO-K1 cells. This endoscope-like system opens a range of exciting applications, in particular, in the targeted in vivo optical microsurgery area.

Rat embryo cells immortalized with transfected oncogenes are transformed by gamma irradiation.

PubMed

Endlich, B; Salavati, R; Sullivan, T; Ling, C C

1992-12-01

Cesium-137 gamma rays were used to transform rat embryo cells (REC) which were first transfected with activated c-myc or c-Ha-ras oncogenes to produce immortal cell lines (REC:myc and REC:ras). When exposed to 6 Gy of 137Cs gamma rays, some cells became morphologically transformed with focus formation frequencies of approximately 3 x 10(-4) for REC:myc and approximately 1 x 10(-4) for REC:ras, respectively. Cells isolated from foci of gamma-ray-transformed REC:myc (REC:myc:gamma) formed anchorage-independent colonies and were tumorigenic in nude mice, but foci from gamma-ray-transformed REC:ras (REC:ras:gamma) did not exhibit either of these criteria of transformation. Similar to the results with gamma irradiation, we observed a sequence-dependent phenomenon when myc and ras were transfected into REC, one at a time. REC immortalized by ras transfection were not converted to a tumorigenic phenotype by secondary transfection with myc, but REC transfected with myc were very susceptible to transformation by subsequent ras transfection. This suggests that myc-immortalized cells are more permissive to transformation via secondary treatments. In sequentially transfected REC, myc expression was high whether it was transfected first or second, whereas ras expression was highest when the ras gene was transfected secondarily into myc-containing REC. Molecular analysis of REC:ras:gamma transformants showed no alterations in structure of the transfected ras or of the endogenous ras, myc, p53, or fos genes. The expression of ras and p53 was increased in some isolates of REC:ras:gamma, but myc and fos expression were not affected. Similarly, REC:myc:gamma transformants did not demonstrate rearrangement or amplification of the transfected or the endogenous myc genes, or of the potentially cooperating Ha-, Ki-, or N-ras genes. Northern hybridization analysis revealed increased expression of N-ras in two isolates, REC:myc:gamma 33 and gamma 41, but no alterations in the expression

Sustained delivery of proangiogenic microRNA-132 by nanoparticle transfection improves endothelial cell transplantation

PubMed Central

Devalliere, Julie; Chang, William G.; Andrejecsk, Jillian W.; Abrahimi, Parwiz; Cheng, Christopher J.; Jane-wit, Dan; Saltzman, W. Mark; Pober, Jordan S.

2014-01-01

Transplantation of endothelial cells (ECs) for therapeutic vascularization or tissue engineering is a promising method for increasing tissue perfusion. Here, we report on a new approach for enhanced EC transplantation using targeted nanoparticle transfection to deliver proangiogenic microRNA-132 (miR-132) to cultured ECs before their transplantation, thereby sensitizing cells to the effects of endogenous growth factors. We synthesized biodegradable PLGA polymer nanoparticles (NPs) that were loaded with miR-132 and coated with cyclic RGD (cRGD) peptides that target integrin αvβ3 expressed on cultured human umbilical vein ECs (HUVECs), increasing NP uptake through clathrin-coated pits. Unlike previously reported NPs for miR delivery, these NPs slowly release RNA for several weeks. The endocytosed NPs remain in clathrin-coated vesicles from which they mediate intracellular delivery of siRNA or miRNA. Transfection of HUVECs with miR-132 enhances growth factor-induced proliferation and migration in 2D culture, producing a 1.8- and 5-fold increase, respectively. However, while the effects of conventional transfection were short-lived, NP transfection produced protein knockdown and biological effects that were significantly longer in duration (≥6 d). Transfection of HUVECs with miR-132 NP resulted in a 2-fold increase in the number of microvessels per square millimeter compared to lipid after transplantation into immunodeficient mice and led to a higher number of mural cell-invested vessels than control transfection. These data suggest that sustained delivery of miR-132 encapsulated in a targeted biodegradable polymer NP is a safe and efficient strategy to improve EC transplantation and vascularization.—Devalliere, J., Chang, W. G., Andrejecsk, J. W., Abrahimi, P., Cheng, C. J., Jane-wit, D., Saltzman, W. M., Pober, J. S. Sustained delivery of proangiogenic microRNA-132 by nanoparticle transfection improves endothelial cell transplantation. PMID:24221087

Thiolated trimethyl chitosan nanocomplexes as gene carriers with high in vitro and in vivo transfection efficiency.

PubMed

Zhao, Xin; Yin, Lichen; Ding, Jieying; Tang, Cui; Gu, Shaohua; Yin, Chunhua; Mao, Yumin

2010-05-21

Trimethyl chitosan-cysteine conjugate (TMC-Cys) was evaluated as non-viral gene carriers to combine the advantages of TMC and thiolated chitosan. TMC-Cys with various molecular weights (30, 100, and 200 kDa) and quaternization degrees (15 and 30%) was allowed to form polyelectrolyte nanocomplexes with plasmid encoding enhanced green fluorescence protein (pEGFP), which demonstrated preferable diameters of below 200 nm and zeta potentials of +15 to +20 mV. Cell binding and uptake of TMC-Cys/pEGFP nanocomplexes (TMC-Cys NC) were enhanced 2.4-3.0 and 1.4-3.0 folds, respectively, compared to TMC/pEGFP nanocomplexes (TMC NC). pEGFP could be easily released from TMC-Cys NC at the intracellular glutathione concentration, which promoted its nuclear transport and accumulation. Consequently, TMC-Cys NC showed a 1.4 to 3.2-fold increase in the transfection efficiency in HEK293 cells as compared to TMC NC and the optimal TMC-Cys(100,30) NC showed a 1.5-fold enhancement than Lipofectamine2000. Such results were further confirmed by in vivo transfection with a 2.3-fold and 4.1-fold higher transfection efficiency of TMC-Cys(100,30) NC than TMC(100,30) NC and Lipofectamine2000, respectively. Therefore, TMC-Cys/DNA nanocomplexes could be a promising gene delivery system with in vitro and in vivo superiority to Lipofectamine2000. Copyright 2010 Elsevier B.V. All rights reserved.

C33-A cells transfected with E6*I or E6*II the short forms of HPV-16 E6, displayed opposite effects on cisplatin-induced apoptosis.

PubMed

Vaisman, Carolina E; Del Moral-Hernandez, Oscar; Moreno-Campuzano, Samadhi; Aréchaga-Ocampo, Elena; Bonilla-Moreno, Raul; Garcia-Aguiar, Israel; Cedillo-Barron, Leticia; Berumen, Jaime; Nava, Porfirio; Villegas-Sepúlveda, Nicolas

2018-03-02

The HPV-16 E6/E7 bicistronic immature transcript produces 4 mature RNAs: the unspliced HPV-16 E6/E7 pre-mRNA product and 3 alternatively spliced mRNAs. The 3 spliced mRNAs encode short forms of the E6 oncoprotein, namely E6*I, E6*II and E6^E7. In this study we showed that transfection of C-33A cells with monocistronic constructs of these cDNAs fused to GFP, produced different effects on apoptosis, after the treatment with cisplatin. Transfection of C-33A cells with the full-length E6-GFP oncoprotein resulted in a 50% decrease in cell death, while the transfection with the E6*I-GFP construct showed only a 25% of diminution of cell death, compared to the control cells. Transfection with the E6^E7-GFP or E7-GFP construct had no effect on the number of the apoptotic cells, compared with control cells. Conversely, transfection with the E6*II construct resulted in higher cell death than the control cells. Taken together, these results suggested that E6*I or E6*II, the short forms of HPV-16 E6, displayed opposite effects on cisplatin-induced apoptosis, when transfected in C-33A cells. Copyright © 2018 Elsevier B.V. All rights reserved.

Development of mRuby2-Transfected C3H10T1/2 Fibroblasts for Musculoskeletal Tissue Engineering

PubMed Central

Yang, Yunzhi Peter

2015-01-01

Mouse C3H10T1/2 fibroblasts are multipotent, mesenchymal stem cell (MSC)-like progenitor cells that are widely used in musculoskeletal research. In this study, we have established a clonal population of C3H10T1/2 cells stably-transfected with mRuby2, an orange-red fluorescence reporter gene. Flow cytometry analysis and fluorescence imaging confirmed successful transfection of these cells. Cell counting studies showed that untransfected C3H10T1/2 cells and mRuby2-transfected C3H10T1/2 cells proliferated at similar rates. Adipogenic differentiation experiments demonstrated that untransfected C3H10T1/2 cells and mRuby2-transfected C3H10T1/2 cells stained positive for Oil Red O and showed increased expression of adipogenic genes including adiponectin and lipoprotein lipase. Chondrogenic differentiation experiments demonstrated that untransfected C3H10T1/2 cells and mRuby2-transfected C3H10T1/2 cells stained positive for Alcian Blue and showed increased expression of chondrogenic genes including aggrecan. Osteogenic differentiation experiments demonstrated that untransfected C3H10T1/2 cells and mRuby2-transfected C3H10T1/2 cells stained positive for alkaline phosphatase (ALP) as well as Alizarin Red and showed increased expression of osteogenic genes including alp, ocn and osf-1. When seeded on calcium phosphate-based ceramic scaffolds, mRuby2-transfected C3H10T1/2 cells maintained even fluorescence labeling and osteogenic differentiation. In summary, mRuby2-transfected C3H10T1/2 cells exhibit mRuby2 fluorescence and showed little-to-no difference in terms of cell proliferation and differentiation as untransfected C3H10T1/2 cells. These cells will be available from American Type Culture Collection (ATCC; CRL-3268™) and may be a valuable tool for preclinical studies. PMID:26407291

Development of mRuby2-Transfected C3H10T1/2 Fibroblasts for Musculoskeletal Tissue Engineering.

PubMed

Ker, Dai Fei Elmer; Sharma, Rashmi; Wang, Evelyna Tsi Hsin; Yang, Yunzhi Peter

2015-01-01

Mouse C3H10T1/2 fibroblasts are multipotent, mesenchymal stem cell (MSC)-like progenitor cells that are widely used in musculoskeletal research. In this study, we have established a clonal population of C3H10T1/2 cells stably-transfected with mRuby2, an orange-red fluorescence reporter gene. Flow cytometry analysis and fluorescence imaging confirmed successful transfection of these cells. Cell counting studies showed that untransfected C3H10T1/2 cells and mRuby2-transfected C3H10T1/2 cells proliferated at similar rates. Adipogenic differentiation experiments demonstrated that untransfected C3H10T1/2 cells and mRuby2-transfected C3H10T1/2 cells stained positive for Oil Red O and showed increased expression of adipogenic genes including adiponectin and lipoprotein lipase. Chondrogenic differentiation experiments demonstrated that untransfected C3H10T1/2 cells and mRuby2-transfected C3H10T1/2 cells stained positive for Alcian Blue and showed increased expression of chondrogenic genes including aggrecan. Osteogenic differentiation experiments demonstrated that untransfected C3H10T1/2 cells and mRuby2-transfected C3H10T1/2 cells stained positive for alkaline phosphatase (ALP) as well as Alizarin Red and showed increased expression of osteogenic genes including alp, ocn and osf-1. When seeded on calcium phosphate-based ceramic scaffolds, mRuby2-transfected C3H10T1/2 cells maintained even fluorescence labeling and osteogenic differentiation. In summary, mRuby2-transfected C3H10T1/2 cells exhibit mRuby2 fluorescence and showed little-to-no difference in terms of cell proliferation and differentiation as untransfected C3H10T1/2 cells. These cells will be available from American Type Culture Collection (ATCC; CRL-3268™) and may be a valuable tool for preclinical studies.

Structural characterization of a new lipid/DNA complex showing a selective transfection efficiency in ovarian cancer cells

NASA Astrophysics Data System (ADS)

Caracciolo, G.; Pozzi, D.; Caminiti, R.; Congiu Castellano, A.

2003-04-01

We investigated, for the first time, by using Energy Dispersive X-ray Diffraction, the structure of a new ternary cationic liposome formulated with dioleoyl trimethylammonium propane (DOTAP), 1,2-dioleoyl-3-phosphatidylethanolamine (DOPE) and cholesterol (Chol) (DDC) which has been recently found to have a selective high gene transfer ability in ovarian cancer cells. Our structural results provide a further experimental support to the widely accepted statement that there is not a simple and direct correlation between structure and transfection efficiency and that the factors controlling cationic lipid/DNA (CL-DNA) complexes-mediated gene transfer depend not only on the formulations of the cationic liposomes and their thermodynamic phase, but also significantly on the cell properties.

Carbon nanoparticles for gene transfection in eukaryotic cell lines.

PubMed

Zanin, H; Hollanda, L M; Ceragioli, H J; Ferreira, M S; Machado, D; Lancellotti, M; Catharino, R R; Baranauskas, V; Lobo, A O

2014-06-01

For the first time, oxygen terminated cellulose carbon nanoparticles (CCN) was synthesised and applied in gene transfection of pIRES plasmid. The CCN was prepared from catalytic of polyaniline by chemical vapour deposition techniques. This plasmid contains one gene that encodes the green fluorescent protein (GFP) in eukaryotic cells, making them fluorescent. This new nanomaterial and pIRES plasmid formed π-stacking when dispersed in water by magnetic stirring. The frequencies shift in zeta potential confirmed the plasmid strongly connects to the nanomaterial. In vitro tests found that this conjugation was phagocytised by NG97, NIH-3T3 and A549 cell lines making them fluorescent, which was visualised by fluorescent microscopy. Before the transfection test, we studied CCN in cell viability. Both MTT and Neutral Red uptake tests were carried out using NG97, NIH-3T3 and A549 cell lines. Further, we use metabolomics to verify if small amounts of nanomaterial would be enough to cause some cellular damage in NG97 cells. We showed two mechanisms of action by CCN-DNA complex, producing an exogenous protein by the transfected cell and metabolomic changes that contributed by better understanding of glioblastoma, being the major finding of this work. Our results suggested that this nanomaterial has great potential as a gene carrier agent in non-viral based therapy, with low cytotoxicity, good transfection efficiency, and low cell damage in small amounts of nanomaterials in metabolomic tests. Copyright © 2014 Elsevier B.V. All rights reserved.

Plasmid transfection in bovine cells: Optimization using a realtime monitoring of green fluorescent protein and effect on gene reporter assay.

PubMed

Osorio, Johan S; Bionaz, Massimo

2017-08-30

Gene reporter technology (GRT) has opened several new avenues for monitoring biological events including the activation of transcription factors, which are central to the study of nutrigenomics. However, this technology relies heavily on the insertion of foreign plasmid DNA into the nuclei of cells (i.e., transfection), which can be very challenging and highly variable among cell types. The objective of this study was to investigate the optimal conditions to generate reliable GRT assay data on bovine immortalized cell lines, Madin Darby Bovine Kidney (MDBK) and bovine mammary epithelial alveolar (MACT) cells. Results are reported for two experiments. In Experiment 1, using 96 well-plate and a robotic inverted fluorescent microscope, we compared transfection efficiency among commercially available transfection reagents (TR) Lipofectamine® 3000 (Lipo3), Lipofectamine® LTX (LipoLTX), and TransIT-X2® (TransX2), three doses of TR (i.e., 0.15, 0.3, and 0.4μL/well), and three doses of Green Fluorescent Protein plasmid DNA (i.e., 10, 25, and 50ng/well). Transfection efficiency and mortality rate were analyzed using CellProfiler software. Transfection efficiency increased until the end of the experiment (20h post-transfection) at which point MACT had greater transfection than MDBK cells (16.3% vs. 2.2%). It is unclear the reason for the low transfection in MDBK cells. Maximal transfection efficiency was obtained with 0.3μL/well of LipoLTX plus 25ng/well of plasmid DNA (ca. 29.5±1.9%) and 0.15μL/well of LipoLTX plus 25ng/well of plasmid DNA (ca. 4.0±0.4%) for MACT and MDBK cells, respectively. The higher amount of TR and DNA was generally associated with higher cell mortality. Using high, medium, and low transfection efficiency conditions determined in Experiment 1, we performed a GRT assay for peroxisome proliferator-activated response element (PPRE) luciferase in MACT and MDBK cells treated with 10nM or 100nM of synthetic Peroxisome Proliferator-activated Receptor

Use of inert gas jets to measure the forces required for mechanical gene transfection

PubMed Central

2012-01-01

Background Transferring genes and drugs into cells is central to how we now study, identify and treat diseases. Several non-viral gene therapy methods that rely on the mechanical disruption of the plasma membrane have been proposed, but the success of these methods has been limited due to a lack of understanding of the mechanical parameters that lead to cell membrane permeability. Methods We use a simple jet of inert gas to induce local transfection of plasmid DNA both in vitro (HeLa cells) and in vivo (chicken chorioallantoic membrane). Five different capillary tube inner diameters and three different gases were used to treat the cells to understand the dependency of transfection efficiency on the dynamic parameters. Results The simple setup has the advantage of allowing us to calculate the forces acting on cells during transfection. We found permeabilization efficiency was related to the dynamic pressure of the jet. The range of dynamic pressures that led to transfection in HeLa cells was small (200 ± 20 Pa) above which cell stripping occurred. We determined that the temporary pores allow the passage of dextran up to 40 kDa and reclose in less than 5 seconds after treatment. The optimized parameters were also successfully tested in vivo using the chorioallantoic membrane of the chick embryo. Conclusions The results show that the number of cells transfected with the plasmid scales with the dynamic pressure of the jet. Our results show that mechanical methods have a very small window in which cells are permeabilized without injury (200 to 290 Pa). This simple apparatus helps define the forces needed for physical cell transfection methods. PMID:22963645

NanoSMGT: transgene transmission into bovine embryos using halloysite clay nanotubes or nanopolymer to improve transfection efficiency.

PubMed

Campos, Vinicius Farias; de Leon, Priscila Marques Moura; Komninou, Eliza Rossi; Dellagostin, Odir Antônio; Deschamps, João Carlos; Seixas, Fabiana Kömmling; Collares, Tiago

2011-11-01

The objectives were to investigate whether: 1) nanotransfectants are more effective than other common transfection methods for SMGT; 2) NanoSMGT is able to transmit exogenous DNA molecules to bovine embryos; and 3) halloysite clay nanotubes (HCNs) can be used as a transfection reagent to improve transgene transmission. Four transfection systems were used: naked DNA (without transfectant), lipofection, nanopolymer, and halloysite clay nanotubes. Plasmid uptake by sperm and its transfer to embryos were quantified by conventional and real-time PCR, as well as EGFP expression by fluorescence microscopy. Furthermore, sperm motility and viability, and embryo development were investigated. Mean number of plasmids taken up was affected (P < 0.05) by transfection procedure, with the nanopolymer being the most effective transfectant (∼ 153 plasmids per spermatozoon). None of the treatments affected sperm motility or viability. The mean number of plasmids transmitted to four-cell stage embryos was higher (P < 0.05) in nanopolymer and HCNs than liposomes and naked DNA groups. The number of embryos carrying the transgene increased from 8-10% using naked DNA or liposomes to 40-45% using nanopolymer or HCN as transfectants (P < 0.05). There were no significant differences among transfection procedures regarding blastocyst formation rate of resulting embryos. However, no EGFP-expressing embryo was identified in any treatment. Therefore, nanotransfectants improved transgene transmission in bovine embryos without deleterious effects on embryo development. To our knowledge, this was the first time that bovine embryos carrying a transgene were produced by NanoSMGT. Copyright © 2011 Elsevier Inc. All rights reserved.

Hydrodynamics based transfection in normal and fibrotic rats

PubMed Central

Yeikilis, Rita; Gal, Shunit; Kopeiko, Natalia; Paizi, Melia; Pines, Mark; Braet, Filip; Spira, Gadi

2006-01-01

AIM: Hydrodynamics based transfection (HBT), the injection of a large volume of naked plasmid DNA in a short time is a relatively simple, efficient and safe method for in vivo transfection of liver cells. Though used for quite some time, the mechanism of gene transfection has not yet been elucidated. METHODS: A luciferase encoding plasmid was injected using the hydrodynamics based procedure into normal and thioacetamide-induced fibrotic Sprague Dawley rats. Scanning and transmission electron microscopy images were taken. The consequence of a dual injection of Ringer solution and luciferase pDNA was followed. Halofuginone, an anti collagen type I inhibitor was used to reduce ECM load in fibrotic rats prior to the hydrodynamic injection. RESULTS: Large endothelial gaps formed as soon as 10’ following hydrodynamic injection; these gradually returned to normal 10 d post injection. Hydrodynamic administration of Ringer 10 or 30 m prior to moderate injection of plasmid did not result in efficient transfection suggesting that endothelial gaps by themselves are not sufficient for gene expression. Gene transfection following hydrodynamic injection in thioacetamide induced fibrotic rats was diminished coinciding with the level of fibrosis. Halofuginone, a specific collagen typeIinhibitor, alleviated this effect. CONCLUSION: The hydrodynamic pressure formed following HBT results in the formation of large endothelial gaps. These gaps, though important in the transfer of DNA molecules from the blood to the space of Disse are not enough to provide the appropriate conditions for hepatocyte transfection. Hydrodynamics based injection is applicable in fibrotic rats provided that ECM load is reduced. PMID:17036386

A convenient method of preparing gene vector for real time monitoring transfection process based on the quantum dots

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

Zhang, Hai-Li; Zhang, Ming-Zhen; Li, Xiang-Yong

2012-11-15

Highlights: ► An easy and direct way to prepare QDs–DNA complexes was developed. ► Surface charge of QDs was tuned with different ratio of amino and glycolate. ► Transfection efficiency was dependent on the surface zeta potentials of QDs. ► Cellular toxicity of this gene vectors is much lower than commercial liposome. ► Whole intracellular behavior of QDs–DNA complexes can be monitored in real time. -- Abstract: Nanoparticle carrier has been developed by combining water-soluble quantum dots and plasmid DNA expressed enhanced green fluorescent protein (EGFP) in a convenient and direct way. First the QDs with different surface charges weremore » obtained by coating with amino and carboxyl terminals at different ratios. Then plasmid DNA was conjugated to QDs via electrostatic interaction. The resultant QDs–DNA complexes showed enhanced resistance to DNase I digestion. The following transfection experiments demonstrated that the transfection efficiency was dependent on the surface charges on QDs. The real time imaging of the transfection process showed that the nanoparticles experienced binding, penetrating the cell membrane and entering cytoplasm in the first 6 h of transfection. The green fluorescence of EGFP began to appear after 18 h transfection and plasmid DNA was fully expressed in the following 6 h. This new QDs–DNA platform showed great potential as new gene delivery carrier.« less

Local gene transfection in the cochlea (Review).

PubMed

Xia, Li; Yin, Shankai

2013-07-01

There is much interest in the potential application of vector-induced gene therapeutic approaches to several forms of hearing disorders due to the poor efficacy of existing treatments. The cochlea is an ideal site for local gene transfection due to its anatomical encapsulation and fluid flow within its ducts. However, this requires the development of novel technologies in materials science and microbial supply vectors for target gene delivery. This review focuses on the introduction of various viral and non-viral vectors as well as injection approaches to transfecting cochlear cells in vivo. Finally, the perspective of local gene therapy was discussed. Therapeutic approaches using local gene transfection may provide a means of cochlear cell and tissue protection and treatment in cases of exogenous hearing loss and endogenous disorders.

Gene Transfection Method Using Atmospheric Pressure Dielectric-Barrier Discharge Plasmas

NASA Astrophysics Data System (ADS)

Sasaki, Shota; Kanzaki, Makoto; Kaneko, Toshiro

2013-09-01

Gene transfection which is the process of deliberately introducing nucleic acids into cells is expected to play an important role in medical treatment because the process is necessary for gene therapy and creation of induced pluripotent stem (iPS) cells. However, the conventional transfection methods have some problems, so we focus attention on promising transfection methods by atmospheric pressure dielectric-barrier discharge (AP-DBD) plasmas. AP-DBD He plasmas are irradiated to the living cell covered with genes. Preliminarily, we use fluorescent dye YOYO-1 instead of the genes and use LIVE/DEAD Stain for cell viability test, and we analyze the transfection efficiency and cell viability under the various conditions. It is clarified that the transfection efficiency is strongly dependence on the plasma irradiation time and cell viability rates is high rates (>90%) regardless of long plasma irradiation time. These results suggest that ROS (Reactive Oxygen Species) and electric field generated by the plasma affect the gene transfection. In addition to this (the plasma irradiation time) dependency, we now investigate the effect of the plasma irradiation under the various conditions.

A strategy to improve serum-tolerant transfection activity of polycation vectors by surface hydroxylation.

PubMed

Luo, Xiao-hua; Huang, Fu-wei; Qin, Si-yong; Wang, Hua-fen; Feng, Jun; Zhang, Xian-zheng; Zhuo, Ren-xi

2011-12-01

The aim of this contribution is to develop a universal method to promote the serum-tolerant capability of polycation-based gene delivery system. A "hydroxylation camouflage" strategy was put forward by coating the polycation vectors with hydroxyl-enriched "skin". Branched polyethyleneimine (PEI) was herein used as the polycation model and modified via the catalyst-free aminolysis reaction with 5-ethyl-5-(hydroxymethyl)-1,3-dioxan-2-oxo (EHDO). PEI-g-EHDO, PEI and alkylated PEI derivative termed as PEI-g-DPA were comparatively explored with respect to the transfection efficiency in the serum-free and serum-conditioned medium. The resultant data indicate that the serum-tolerant capability largely depended on the surface composition and substitution degree. In addition to the reduced surface charge, the introduced function caused by hydroxyl coating is believed to play a crucial role for the improved properties of PEI-g-EHDOs. The EHDO modification can effectively inhibit the adsorption of BSA proteins onto polyplexes surface. And the polyplexes stability was remarkably enhanced in the presence of DNase and heparin after EHDO modification. Note that the transfection activity of PEI-g-EHDO(34.5%) in the serum-conditioned medium was even higher than that without serum addition. In contrast, serum addition led to appreciable reduction in the transfection efficiency mediated by PEI and PEI-g-DPAs. Specifically, as far as the transfection activity in the presence of serum is concerned, PEI-g-EHDO could be up to 30-fold higher than unmodified PEI25k. PEI-g-EHDO(34.5%) displayed little to no hemolytic effect and high cell-biocompatibility with nearly no cytotoxicity detected in 293T cells and HeLa cells. Taking into account the high biocompatibility and serum-tolerant transfection activity, PEI-g-EHDO(34.5%) holds great potential for the use as efficient gene vector. More importantly, it is expected that such "hydroxylation camouflage" strategy may be universally applicable

Synergistic effect of electrical and chemical factors on endocytosis in micro-discharge plasma gene transfection

NASA Astrophysics Data System (ADS)

Jinno, M.; Ikeda, Y.; Motomura, H.; Isozaki, Y.; Kido, Y.; Satoh, S.

2017-06-01

We have developed a new micro-discharge plasma (MDP)-based gene transfection method, which transfers genes into cells with high efficiency and low cytotoxicity; however, the mechanism underlying the method is still unknown. Studies revealed that the N-acetylcysteine-mediated inhibition of reactive oxygen species (ROS) activity completely abolished gene transfer. In this study, we used laser-produced plasma to demonstrate that gene transfer does not occur in the absence of electrical factors. Our results show that both electrical and chemical factors are necessary for gene transfer inside cells by microplasma irradiation. This indicates that plasma-mediated gene transfection utilizes the synergy between electrical and chemical factors. The electric field threshold required for transfection was approximately 1 kV m-1 in our MDP system. This indicates that MDP irradiation supplies sufficient concentrations of ROS, and the stimulation intensity of the electric field determines the transfection efficiency in our system. Gene transfer by plasma irradiation depends mainly on endocytosis, which accounts for at least 80% of the transfer, and clathrin-mediated endocytosis is a dominant endocytosis. In plasma-mediated gene transfection, alterations in electrical and chemical factors can independently regulate plasmid DNA adhesion and triggering of endocytosis, respectively. This implies that plasma characteristics can be adjusted according to target cell requirements, and the transfection process can be optimized with minimum damage to cells and maximum efficiency. This may explain how MDP simultaneously achieves high transfection efficiency with minimal cell damage.

Regional and National Grid Integration Studies Consistently Show Higher

Science.gov Websites

Levels of Renewables Are Possible | Energy Analysis | NREL Regional and National Grid Integration Studies Consistently Show Higher Levels of Renewables Are Possible Regional and National Grid Integration Studies Consistently Show Higher Levels of Renewables Are Possible Analysis Insights: April 2015

Structure-activity correlation in transfection promoted by pyridinium cationic lipids.

PubMed

Parvizi-Bahktar, P; Mendez-Campos, J; Raju, L; Khalique, N A; Jubeli, E; Larsen, H; Nicholson, D; Pungente, M D; Fyles, T M

2016-03-21

The efficiency of the transfection of a plasmid DNA encoding a galactosidase promoted by a series of pyridinium lipids in mixtures with other cationic lipids and neutral lipids was assessed in CHO-K1 cells. We identify key molecular parameters of the lipids in the mixture - clog P, lipid length, partial molar volume - to predict the morphology of the lipid-DNA lipoplex and then correlate these same parameters with transfection efficiency in an in vitro assay. We define a Transfection Index that provides a linear correlation with normalized transfection efficiency over a series of 90 different lipoplex compositions. We also explore the influence of the same set of molecular parameters on the cytotoxicity of the formulations.

The Renilla luciferase gene as a reference gene for normalization of gene expression in transiently transfected cells.

PubMed

Jiwaji, Meesbah; Daly, Rónán; Pansare, Kshama; McLean, Pauline; Yang, Jingli; Kolch, Walter; Pitt, Andrew R

2010-12-31

The importance of appropriate normalization controls in quantitative real-time polymerase chain reaction (qPCR) experiments has become more apparent as the number of biological studies using this methodology has increased. In developing a system to study gene expression from transiently transfected plasmids, it became clear that normalization using chromosomally encoded genes is not ideal, at it does not take into account the transfection efficiency and the significantly lower expression levels of the plasmids. We have developed and validated a normalization method for qPCR using a co-transfected plasmid. The best chromosomal gene for normalization in the presence of the transcriptional activators used in this study, cadmium, dexamethasone, forskolin and phorbol-12-myristate 13-acetate was first identified. qPCR data was analyzed using geNorm, Normfinder and BestKeeper. Each software application was found to rank the normalization controls differently with no clear correlation. Including a co-transfected plasmid encoding the Renilla luciferase gene (Rluc) in this analysis showed that its calculated stability was not as good as the optimised chromosomal genes, most likely as a result of the lower expression levels and transfection variability. Finally, we validated these analyses by testing two chromosomal genes (B2M and ActB) and a co-transfected gene (Rluc) under biological conditions. When analyzing co-transfected plasmids, Rluc normalization gave the smallest errors compared to the chromosomal reference genes. Our data demonstrates that transfected Rluc is the most appropriate normalization reference gene for transient transfection qPCR analysis; it significantly reduces the standard deviation within biological experiments as it takes into account the transfection efficiencies and has easily controllable expression levels. This improves reproducibility, data validity and most importantly, enables accurate interpretation of qPCR data.

Mechanism of gene transfection by polyamidoamine (PAMAM) dendrimers modified with ornithine residues.

PubMed

Kumar, Ajay; Yellepeddi, Venkata K; Vangara, Kiran K; Strychar, Kevin B; Palakurthi, Srinath

2011-11-01

The aim of this study was to prepare and investigate the mechanism of uptake of the dendriplexes prepared with ornithine-conjugated polyamidoamine (PAMAM) G4 dendrimers. Ornithine-conjugated PAMAMG4 dendrimers were prepared by Fmoc synthesis. A comparative transfection study in NCI H157G cells and polyamine transport-deficient cell line NCI H157R was performed to confirm the role of the polyamine transporter system (PAT) in the dendriplex uptake. Transfection efficiency significantly increased with increase in generation number and extent of ornithine conjugation. Transfection efficiency of the PAMAMG4-ORN60 dendrimers significantly decreased in presence of excess of ornithine (P < 0.05) and paraquat (P < 0.01) but not of PAMAMG4 dendrimers. Transfection efficiency of PAMAMG4-ORN60 was significantly low in NCI H157R (31.66 ± 3.95%, RFU: 17.87 ± 1.34) as compared to NCI H157G cell line (63.07 ± 6.8%, relative fluorescence units (RFU): 23.28 ± 0.66). Results indicate the role of PAT in addition to charge-mediated endocytosis in the internalization of ornithine-conjugated PAMAMG4 dendrimers. Cytotoxicity analysis (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay) in human embryonic kidney cell line (HEK) 293T cells showed that the dendriplexes were non-toxic at N/P 10.

Cell cycle distribution, cellular viability and mRNA expression of hGCase-gene-transfected cells in dairy goat.

PubMed

Zhang, Yan-Li; Wan, Yong-Jie; Wang, Zi-Yu; Qi, Wei-Wei; Zhou, Zheng-Rong; Huang, Rong; Wang, Feng

2010-05-07

Nuclear transfer using transgenic donor cells is an efficient way of generating transgenic goats, wherein the preparation of competent transgenic donor cells is the pivotal upstream step. We have measured the efficiency of transfection with a plasmid containing hGCase (human lysosomal acid beta-glucosidase) gene into goat FFC (fetal-derived fibroblast cells), MEC (mammary epithelial cells) and AEFC (adult ear skin-derived fibroblast cells), and the characteristics of cell cycle, apoptosis and chromosome abnormalities after transfection. The expression of genes involved in imprinting [IGF2 (insulin-like growth factor 2), IGF2R (IGF2 receptor)], apoptosis (Bax), stress (heat-shock protein, Hsp70.1), cellular connections [Cx43 (connexin 43)] and DNA methylation [DNMT1 (DNA methyltransferase 1)] in transgenic fetal cells has been investigated. The hGCase transgene was successfully detected in the transfected cell lines, and chromosomal stability remained similar in FFC and transgenic FFC (70.9 compared with 66.8%), whereas a smaller percentage (P<0.05) of cells at G(0)/G(1) in the transgenic FFC, MEC and AEFC (T-FFC, T-MEC and T-AEFC), and higher percentage (P<0.05) of apoptotic cells in T-FFC than the non-transfected controls were detected by flow cytometric analysis. Among the genes tested, the relative expressions of IGF2, IGF2R and transcripts of Cx43 were significantly higher (P<0.05) in T-FFC compared with non-transfected FFC. These novel findings on gene expression in transgenic fetal cells may have certain implications in the biopharming industry and in our understanding the low efficiency of transgenic cloning.

Toward Contactless Biology: Acoustophoretic DNA Transfection

NASA Astrophysics Data System (ADS)

Vasileiou, Thomas; Foresti, Daniele; Bayram, Adem; Poulikakos, Dimos; Ferrari, Aldo

2016-02-01

Acoustophoresis revolutionized the field of container-less manipulation of liquids and solids by enabling mixing procedures which avoid contamination and loss of reagents due to the contact with the support. While its applications to chemistry and engineering are straightforward, additional developments are needed to obtain reliable biological protocols in a contactless environment. Here, we provide a first, fundamental step towards biological reactions in air by demonstrating the acoustophoretic DNA transfection of mammalian cells. We developed an original acoustophoretic design capable of levitating, moving and mixing biological suspensions of living mammalians cells and of DNA plasmids. The precise and sequential delivery of the mixed solutions into tissue culture plates is actuated by a novel mechanism based on the controlled actuation of the acoustophoretic force. The viability of the contactless procedure is tested using a cellular model sensitive to small perturbation of neuronal differentiation pathways. Additionally, the efficiency of the transfection procedure is compared to standard, container-based methods for both single and double DNA transfection and for different cell types including adherent growing HeLa cancer cells, and low adhesion neuron-like PC12 cells. In all, this work provides a proof of principle which paves the way to the development of high-throughput acoustophoretic biological reactors.

Toward Contactless Biology: Acoustophoretic DNA Transfection.

PubMed

Vasileiou, Thomas; Foresti, Daniele; Bayram, Adem; Poulikakos, Dimos; Ferrari, Aldo

2016-02-01

Acoustophoresis revolutionized the field of container-less manipulation of liquids and solids by enabling mixing procedures which avoid contamination and loss of reagents due to the contact with the support. While its applications to chemistry and engineering are straightforward, additional developments are needed to obtain reliable biological protocols in a contactless environment. Here, we provide a first, fundamental step towards biological reactions in air by demonstrating the acoustophoretic DNA transfection of mammalian cells. We developed an original acoustophoretic design capable of levitating, moving and mixing biological suspensions of living mammalians cells and of DNA plasmids. The precise and sequential delivery of the mixed solutions into tissue culture plates is actuated by a novel mechanism based on the controlled actuation of the acoustophoretic force. The viability of the contactless procedure is tested using a cellular model sensitive to small perturbation of neuronal differentiation pathways. Additionally, the efficiency of the transfection procedure is compared to standard, container-based methods for both single and double DNA transfection and for different cell types including adherent growing HeLa cancer cells, and low adhesion neuron-like PC12 cells. In all, this work provides a proof of principle which paves the way to the development of high-throughput acoustophoretic biological reactors.

Toward Contactless Biology: Acoustophoretic DNA Transfection

PubMed Central

Vasileiou, Thomas; Foresti, Daniele; Bayram, Adem; Poulikakos, Dimos; Ferrari, Aldo

2016-01-01

Acoustophoresis revolutionized the field of container-less manipulation of liquids and solids by enabling mixing procedures which avoid contamination and loss of reagents due to the contact with the support. While its applications to chemistry and engineering are straightforward, additional developments are needed to obtain reliable biological protocols in a contactless environment. Here, we provide a first, fundamental step towards biological reactions in air by demonstrating the acoustophoretic DNA transfection of mammalian cells. We developed an original acoustophoretic design capable of levitating, moving and mixing biological suspensions of living mammalians cells and of DNA plasmids. The precise and sequential delivery of the mixed solutions into tissue culture plates is actuated by a novel mechanism based on the controlled actuation of the acoustophoretic force. The viability of the contactless procedure is tested using a cellular model sensitive to small perturbation of neuronal differentiation pathways. Additionally, the efficiency of the transfection procedure is compared to standard, container-based methods for both single and double DNA transfection and for different cell types including adherent growing HeLa cancer cells, and low adhesion neuron-like PC12 cells. In all, this work provides a proof of principle which paves the way to the development of high-throughput acoustophoretic biological reactors. PMID:26828312

Transfection of Fv-1 permissive and restrictive mouse cells with integrated DNA of murine leukemia viruses (host range restriction/Fv-1 gene/DNA transfection)

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

Hsu, I.C.; Yang, W.K.; Tennant, R.W.

1978-03-01

Whole-cell DNA preparations isolated from SC-1 cells chronically infected with N- or B-tropic murine leukemia viruses (MuLV) were tested for infectious activity in an Fv-1/sup n/ (NIH-3T3) and two Fv-1/sup b/ (C57BL/6 and SV-A31) cell cultures. Efficiency of transfection for all DNAs was better in the NIH-3T3 cells than in C57BL/6 or SV-A31 cells; and an (N-tropic MuLV)SC-1 cell DNA preparation was slightly more infectious than a (B-tropic MuLV)SC-1 cell DNA preparation in all three cell cultures, regardless of their Fv-1 geonotypes. Progeny viruses from the transfection showed N- or B-tropism corresponding to that of the parent viruses produced bymore » the infected SC-I cells that were used for the DNA preparation. DNA dose-response studies in NIH-3T3 cells revealed a one-hit mechanism for both the (B-tropic MuLV)SC-1 cell DNA and the (N-tropic MuLV)SC-1 cell DNA preparation. These results demonstrate that, in contrast to virion infection, transfection of N- and B-tropic MuLV with DNA preparations from chronically infected cells is not affected by the Fv-1 gene.« less

Water-soluble N-[(2-hydroxy-3-trimethylammonium)propyl]chitosan chloride as a nucleic acids vector for cell transfection.

PubMed

Faizuloev, Evgeny; Marova, Anna; Nikonova, Alexandra; Volkova, Irina; Gorshkova, Marina; Izumrudov, Vladimir

2012-08-01

To endow the cationic polysaccharides with solubility in the whole pH-range without loss of functionality of the amino groups, different chitosan samples were treated with glycidyltrimethylammonium chloride. Each modified unit of the exhaustively alkylated quaternized chitosan (QCht) contained both quaternary and secondary amino groups. The intercalated dye displacement assay and ζ-potential measurements implied stability of QCht polyplexes at physiological conditions and protonation of the secondary amino groups in slightly acidic media which is favorable for transfection according to proton sponge mechanism. The cytotoxicity and transfection efficacy increased with the chain lengthening. Nevertheless, the longest chains of QCht, 250 kDa were less toxic than PEI for COS-1 cells and revealed comparable and even significantly higher transfection activity of siRNA and plasmid DNA, respectively. Thus, highly polymerized QCht (250 kDa) provided the highest level of the plasmid DNA transfection being 5 and 80 times more active than QCht (100 kDa) and QCht (50 kDa), respectively, and 4-fold more effective than PEI, 25 kDa. The established influence of QCht molecular weight on toxicity and transfection efficacy allows elaborating polysaccharide vectors that possess rational balance of these characteristics. Copyright © 2012 Elsevier Ltd. All rights reserved.

Lipofection: a highly efficient, lipid-mediated DNA-transfection procedure.

PubMed Central

Felgner, P L; Gadek, T R; Holm, M; Roman, R; Chan, H W; Wenz, M; Northrop, J P; Ringold, G M; Danielsen, M

1987-01-01

A DNA-transfection protocol has been developed that makes use of a synthetic cationic lipid, N-[1-(2,3-dioleyloxy)propyl]-N,N,N-trimethylammonium chloride (DOTMA). Small unilamellar liposomes containing DOTMA interact spontaneously with DNA to form lipid-DNA complexes with 100% entrapment of the DNA, DOTMA facilitates fusion of the complex with the plasma membrane of tissue culture cells, resulting in both uptake and expression of the DNA. The technique is simple, highly reproducible, and effective for both transient and stable expression of transfected DNA. Depending upon the cell line, lipofection is from 5- to greater than 100-fold more effective than either the calcium phosphate or the DEAE-dextran transfection technique. Images PMID:2823261

Ultrasound-mediated interferon {beta} gene transfection inhibits growth of malignant melanoma

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

Yamaguchi, Kazuki; Department of Anatomy, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka City 814-0180; Feril, Loreto B., E-mail: ferilism@yahoo.com

2011-07-22

Highlights: {yields} Successful ultrasound-mediated transfection of melanoma (C32) cells with IFN-{beta} genes both in vitro and in vivo. {yields} Ultrasound-mediated IFN-{beta} transfection inhibited proliferation of melanoma cells in vitro. {yields} Ultrasound-mediated IFN-{beta} transfection inhibited melanoma tumor growth in vivo. -- Abstract: We investigated the effects of ultrasound-mediated transfection (sonotransfection) of interferon {beta} (IFN-{beta}) gene on melanoma (C32) both in vitro and in vivo. C32 cells were sonotransfected with IFN-{beta} in vitro. Subcutaneous C32 tumors in mice were sonicated weekly immediately after intra-tumor injection with IFN-{beta} genes mixed with microbubbles. Successful sonotransfection with IFN-{beta} gene in vitro was confirmed by ELISA,more » which resulted in C32 growth inhibition. In vivo, the growth ratio of tumors transfected with IFN-{beta} gene was significantly lower than the other experimental groups. These results may lead to a new method of treatment against melanoma and other hard-to-treat cancers.« less

Nonviral transfection of suspension cells in ultrasound standing wave fields.

PubMed

Lee, Yu-Hsiang; Peng, Ching-An

2007-05-01

Ultrasound-induced cavitation has been widely used for delivering DNA vectors into cells. However, this approach may seriously disrupt cell membranes and cause lethal damage when cells are exposed to the inertial cavitation field. In this study, instead of using sonoporation, ultrasound standing wave fields (USWF) were explored for nonviral transfection of suspension cells. Acoustic resonance in a tubular chamber was generated from the interference of waves emitted from a piezoelectric transducer and consequently reflected from a borosilicate glass coverslip. The suspended K562 erythroleukemia cells were transfected by polyethyleneimine (PEI)/DNA complexes with and without exposure to 1-MHz USWF for 5 min. During USWF exposure, K562 cells moved to the pressure nodal planes first and formed cell bands by the primary radiation force. Nanometer-sized PEI/DNA complexes, circulated between nodal planes by acoustic microstreaming, then used the cell agglomerates as the nucleating sites on which to attach. After incubation at 37 degrees C for 48 h, the efficiency of nonviral transfection based on EGFP transgene expression was determined by fluorescent microscopy and fluorometry. Both studies showed that USWF brought suspended K562 cells and PEI/DNA complexes into close contact at the pressure nodal planes, yielding an approximately 10-fold increment of EGFP transgene expression compared with the group without ultrasonic treatment.

Chitosan derivatives for gene transfer: effect of phosphorylcholine and diethylaminoethyl grafts on the in vitro transfection efficiency.

PubMed

Picola, Isadora Pfeifer Dalla; Shi, Qin; Fernandes, Júlio Cesar; Petrônio, Maicon Segalla; Lima, Aline Margarete Furuyama; de Oliveira Tiera, Vera Aparecida; Tiera, Marcio José

2016-11-01

The purpose of this work was to improve the functional properties of chitosan for gene transfer by inserting phosphorylcholine (PC) and diethylaminoethyl (DEAE) groups into the main chain. A series of derivatives containing increasing contents of DEAE and a fixed content of PC groups were synthesized and characterized, aiming to evaluate the effect of these groups on the nanoparticles' properties and the in vitro transfection efficiency. The derivatives were soluble at physiological pH levels and all derivatives were less cytotoxic than the control, the lipid lipofectamine. The obtained derivatives complexed pDNA into nanoparticles with smaller sizes and higher zeta potentials than plain chitosan. The in vitro transfection was performed with nanoparticles prepared at pH 6.3 and 7.4 and the results showed that nanoparticles prepared with derivatives containing 20% of PC groups (PC18-CH) and high degrees of substitution by DEAE (PC20-CH-DEAE100, CH-DEAE80, CH-DEAE100) displayed the better transfection efficiencies in HeLa cells, reaching relative values comparable to lipofectamine. The most effective derivative, PC18CH, was selected for complexation with siRNA and its complexes demonstrated an in vitro knockdown efficiency highly dependent on the N/P ratio. Our combined results indicated that, by means of controlled modifications, the limitations of chitosan can be overcome to obtain more effective carriers based on chitosan, and the derivatives here studied hold potential for in vivo studies.

[Detection of stable expression of human interlukin-2 gene in transfected keratinocytes].

PubMed

Liao, W; Liu, Y; Ye, L

1999-09-01

To investigate the stable expression and secretion of human interlukin-2 gene in transfected keratinocytes. Keratinocytes were transfected with lipofectamine and selected by G418. Then the samples were analyzed with the techniques of DNA dot blot, RNA dot blot, hybridization in situ, immunohistochemistry, Western blot and MTT. The positive signals were observed in transfected keratinocytes by DNA dot blot, RNA dot blot, hybridization in situ and immunohistochemistry. With Western blot analysis, a specific band exhibiting a molecular weight of 15,000 was detected in transfected keratinocytes, which was in acordance with that of IL-2. The expression of IL-2 can maintain for up to 1 month. The amounts of IL-2 in the supernatants of two and four passages transfected keratinocytes were 27.7 U/ml and 15.0 U/ml, respectively. Keratinocytes have the potential for stable gene expression and secretion of active transgene products. Thus, it is possible to use keratinocytes as a target cell for gene transfection, gene expression and even gene therapy.

Covalently bound DNA on naked iron oxide nanoparticles: Intelligent colloidal nano-vector for cell transfection.

PubMed

Magro, Massimiliano; Martinello, Tiziana; Bonaiuto, Emanuela; Gomiero, Chiara; Baratella, Davide; Zoppellaro, Giorgio; Cozza, Giorgio; Patruno, Marco; Zboril, Radek; Vianello, Fabio

2017-11-01

Conversely to common coated iron oxide nanoparticles, novel naked surface active maghemite nanoparticles (SAMNs) can covalently bind DNA. Plasmid (pDNA) harboring the coding gene for GFP was directly chemisorbed onto SAMNs, leading to a novel DNA nanovector (SAMN@pDNA). The spontaneous internalization of SAMN@pDNA into cells was compared with an extensively studied fluorescent SAMN derivative (SAMN@RITC). Moreover, the transfection efficiency of SAMN@pDNA was evaluated and explained by computational model. SAMN@pDNA was prepared and characterized by spectroscopic and computational methods, and molecular dynamic simulation. The size and hydrodynamic properties of SAMN@pDNA and SAMN@RITC were studied by electron transmission microscopy, light scattering and zeta-potential. The two nanomaterials were tested by confocal scanning microscopy on equine peripheral blood-derived mesenchymal stem cells (ePB-MSCs) and GFP expression by SAMN@pDNA was determined. Nanomaterials characterized by similar hydrodynamic properties were successfully internalized and stored into mesenchymal stem cells. Transfection by SAMN@pDNA occurred and GFP expression was higher than lipofectamine procedure, even in the absence of an external magnetic field. A computational model clarified that transfection efficiency can be ascribed to DNA availability inside cells. Direct covalent binding of DNA on naked magnetic nanoparticles led to an extremely robust gene delivery tool. Hydrodynamic and chemical-physical properties of SAMN@pDNA were responsible of the successful uptake by cells and of the efficiency of GFP gene transfection. SAMNs are characterized by colloidal stability, excellent cell uptake, persistence in the host cells, low toxicity and are proposed as novel intelligent DNA nanovectors for efficient cell transfection. Copyright © 2017 Elsevier B.V. All rights reserved.

Novel dextran-spermine conjugates as transfecting agents: comparing water-soluble and micellar polymers.

PubMed

Eliyahu, H; Makovitzki, A; Azzam, T; Zlotkin, A; Joseph, A; Gazit, D; Barenholz, Y; Domb, A J

2005-03-01

Recently, a novel cationic polymer, dextran-spermine (D-SPM) was developed for gene delivery. An efficient transfection was obtained using this polycation for a variety of genes and cell lines in serum-free or serum-poor medium. However, transfection using the water-soluble D-SPM-based polyplexes decreased with increasing serum concentration in cell culture in a concentration-dependent manner, reaching 95% inhibition at 50% serum in the cell growth medium. In order to overcome this obstacle, oleyl derivatives of D-SPM (which form micelles in aqueous phase) were synthesized at 1, 10, and 20 mol% of oleyl moiety to polymer epsilon-NH2 to form N-oleyl-D-SPM (ODS). Polyplexes based on ODS transfected well in medium containing 50% serum. Comparison with polyplexes based on well-established polymers (branched and linear polyethyleneimine) and with DOTAP/Cholesterol lipoplexes showed that regarding beta-galactosidase transgene expression level and cytotoxicity in tissue culture, the D-SPM and ODS compare well with the above polyplexes and lipoplexes. Intracellular trafficking using FITC-labeled ODS and Rhodamine-labeled pGeneGrip plasmid cloned with hBMP2 monitored by confocal microscopy revealed that during the transfection process the fluorescent-labeled polymer concentrates in the Golgi apparatus and around the nucleus, while the cell cytoplasm was free of fluorescent particles, suggesting that the polyplexes move in the cell toward the nucleus by vesicular transport through the cytoplasm and not by a random diffusion. We found that the plasmids penetrate the cell nucleus without the polymer. Preliminary results in zebra fish and mice demonstrate the potential of ODS to serve as an efficient nonviral vector for in vivo transfection.

Hormonal induction of transfected genes depends on DNA topology.

PubMed Central

Piña, B; Haché, R J; Arnemann, J; Chalepakis, G; Slater, E P; Beato, M

1990-01-01

Plasmids containing the hormone regulatory element of mouse mammary tumor virus linked to the thymidine kinase promoter of herpes simplex virus and the reporter gene chloramphenicol acetyltransferase of Escherichia coli respond to glucocorticoids and progestins when transfected into appropriate cells. In the human mammary tumor cell line T47D, the response to progestins, but not to glucocorticoids, is highly dependent on the topology of the transfected DNA. Although negatively supercoiled plasmids respond optimally to the synthetic progestin R5020, their linearized counterparts exhibit markedly reduced progestin inducibility. This is not due to changes in the efficiency of DNA transfection, since the amount of DNA incorporated into the cell nucleus is not significantly dependent on the initial topology of the plasmids. In contrast, cotransfection experiments with glucocorticoid receptor cDNA in the same cell line show no significant influence of DNA topology on induction by dexamethasone. A similar result was obtained with fibroblasts that contain endogenous glucocorticoid receptors. When the distance between receptor-binding sites or between the binding sites and the promoter was increased, the dependence of progestin induction on DNA topology was more pronounced. In contrast to the original plasmid, these constructs also revealed a similar topological dependence for induction by glucocorticoids. The differential influence of DNA topology is not due to differences in the affinity of the two hormone receptors for DNA of various topologies, but probably reflects an influence of DNA topology on the interaction between different DNA-bound receptor molecules and between receptors and other transcription factors. Images PMID:2153920

Targeting the kinesin Eg5 to monitor siRNA transfection in mammalian cells.

PubMed

Weil, D; Garçon, L; Harper, M; Duménil, D; Dautry, F; Kress, M

2002-12-01

RNA interference, the inhibition of gene expression by double-stranded RNA, provides a powerful tool for functional studies once the sequence of a gene is known. In most mammalian cells, only short molecules can be used because long ones induce the interferon pathway. With the identification of a proper target sequence, the penetration of the oligonucleotides constitutes the most serious limitation in the application of this technique. Here we show that a small interfering RNA (siRNA) targeting the mRNA of the kinesin Eg5 induces a rapid mitotic arrest and provides a convenient assay for the optimization of siRNA transfection. Thus, dose responses can be established for different transfection techniques, highlighting the great differences in response to transfection techniques of various cell types. We report that the calcium phosphate precipitation technique can be an efficient and cost-effective alternative to Oligofectamine in some adherent cells, while electroporation can be efficient for some cells growing in suspension such as hematopoietic cells and some adherent cells. Significantly, the optimal parameters for the electroporation of siRNA differ from those for plasmids, allowing the use of milder conditions that induce less cell toxicity. In summary, a single siRNA leading to an easily assayed phenotype can be used to monitor the transfection of siRNA into any type of proliferating cells of both human and murine origin.

Transformation and radiosensitivity of human diploid skin fibroblasts transfected with activated ras oncogene and SV40 T-antigen.

PubMed

Su, L N; Little, J B

1992-08-01

Three normal human diploid cell strains were transfected with an activated Ha-ras oncogene (EJ ras) or SV40 T-antigen. Multiple clones were examined for morphological alterations, growth requirements, ability to grow under anchorage independent conditions, immortality and tumorigenicity in nude mice. Clones expressing SV40 T-antigen alone or in combination with ras protein p21 were significantly radioresistant as compared with their parent cells or clones transfected with the neo gene only. This radioresistant phenotype persisted in post-crisis, immortalized cell lines. Cells transfected with EJ ras alone showed no morphological alterations nor significant changes in radiosensitivity. Cell clones expressing ras and/or SV40 T-antigen showed a reduced requirement for serum supplements, an increase in aneuploidy and chromosomal aberrations, and enhanced growth in soft agar as an early cellular response to SV40 T-antigen expression. The sequential order of transfection with SV40 T-antigen and ras influenced radio-sensitivity but not the induction of morphological changes. These data suggest that expression of the SV40 T-antigen but not activated Ha-ras plays an important role in the radiosensitivity of human diploid cells. The radioresistant phenotype in SV40 T transfected cells was not related to the enhanced level of genetic instability seen in pre-crisis and newly immortalized cells, nor to the process of immortalization itself.

Enduring high-efficiency in vivo transfection of neurons with non-viral magnetoparticles in the rat visual cortex for optogenetic applications.

PubMed

Soto-Sánchez, Cristina; Martínez-Navarrete, Gema; Humphreys, Lawrence; Puras, Gustavo; Zarate, Jon; Pedraz, José Luis; Fernández, Eduardo

2015-05-01

This work demonstrates the successful long-term transfection in vivo of a DNA plasmid vector in rat visual cortex neurons using the magnetofection technique. The transfection rates reached values of up to 97% of the neurons after 30days, comparable to those achieved by viral vectors. Immunohistochemical treatment with anti-EGFP antibodies enhanced the detection of the EYFP-channelrhodopsin expression throughout the dendritic trees and cell bodies. These results show that magnetic nanoparticles offer highly efficient and enduring in vivo high-rate transfection in identified neurons of an adult mammalian brain and suggest that the magnetotechnique facilitates the introduction of large functional genetic material like channelrhodopsin with safe non-viral vectors using minimally invasive approaches. Gene therapy may be one of the treatment modalities for neurological diseases in the future. The use of viral transfection remains a concern due to restrictions to the size limit of the genetic material able to be packed, as well as safety issues. In this work, the authors evaluated magnetoplexes as an alternative vehicle. The results showed very promising data in that these nanoparticles could offer high transfection efficiency. Copyright © 2015 Elsevier Inc. All rights reserved.

Role of cholesterol on the transfection barriers of cationic lipid/DNA complexes

NASA Astrophysics Data System (ADS)

Pozzi, Daniela; Cardarelli, Francesco; Salomone, Fabrizio; Marchini, Cristina; Amenitsch, Heinz; Barbera, Giorgia La; Caracciolo, Giulio

2014-08-01

Most lipid formulations need cholesterol for efficient transfection, but the precise motivation remains unclear. Here, we have investigated the effect of cholesterol on the transfection efficiency (TE) of cationic liposomes made of 1,2-dioleoyl-3-trimethylammonium-propane and dioleoylphosphocholine in Chinese hamster ovary cells. The transfection mechanisms of cholesterol-containing lipoplexes have been investigated by TE, synchrotron small angle X-ray scattering, and laser scanning confocal microscopy experiments. We prove that cholesterol-containing lipoplexes enter the cells using different endocytosis pathways. Formulations with high cholesterol content efficiently escape from endosomes and exhibit a lamellar-nonlamellar phase transition in mixture with biomembrane mimicking lipid formulations. This might explain both the DNA release ability and the high transfection efficiency. These studies highlight the enrichment in cholesterol as a decisive factor for transfection and will contribute to the rational design of lipid nanocarriers with superior TE.

Over-expression of brain-derived neurotrophic factor in mesenchymal stem cells transfected with recombinant lentivirus BDNF gene.

PubMed

Zhang, X; Zhu, J; Zhang, K; Liu, T; Zhang, Z

2016-12-30

This study was aimed at investigating the expression of brain-derived neurotrophic factor (BDNF) in mesenchymal stem cells (MSCs) modified with recombinant lentivirus bearing BDNF gene. Lentivirus vectors bearing BDNF gene were constructed. MSCs were isolated from rats and cultured. The lentiviral vectors containing BDNF gene were transfected into the MSCs, and BDNF gene and protein expressions were monitored with enhanced green fluorescent protein (EGFP). RT-PCR and Western blot were used to measure gene and protein expressions, respectibvely in MSCs, MSCs-EGFP and MSCs-EGFP-BDNF groups. Green fluorescence assay confirmed successful transfection of BDNF gene recombinant lentivirus into MSCs. RT-PCR and Western blot revealed that BDNF gene and protein expressions in the MSCs-EGFP-BDNF group were significantly higher than that in MSCs group and MSCs-EGFP group. There were no statistically significant differences in gene expression between MSCs and MSCs-EGFP groups. MSCs can over-express BDNF when transfected with recombinant lentivirus bearing BDNF gene.

Design, synthesis, and in vitro transfection biology of novel tocopherol based monocationic lipids: a structure-activity investigation.

PubMed

Kedika, Bhavani; Patri, Srilakshmi V

2011-01-27

Herein, we report on the design, synthesis, and in vitro gene delivery efficacies of five novel tocopherol based cationic lipids (1-5) in transfecting CHO, B16F10, A-549, and HepG2 cells. The in vitro gene transfer efficiencies of lipids (1-5) were evaluated by both β-galactosidase reporter gene expression and inverted fluorescent microscopic experiments. The results of the present structure-activity investigation convincingly demonstrate that the tocopherol based lipid with three hydroxyl groups in its headgroup region showed 4-fold better transfection efficiency than the commercial formulation. The results also demonstrate that these tocopherol based lipids may be targeted to liver. Transfection efficiency of all the relevant lipids was maintained even when the serum was present during the transfection conditions. The results indicated that the designed systems are quite capable of transferring the DNA into all four types of cells studied with low or no toxicity.

Improving ultrasound gene transfection efficiency by controlling ultrasound excitation of microbubbles

PubMed Central

Fan, Z.; Chen, D.; Deng, C.X.

2013-01-01

Ultrasound application in the presence of microbubbles has shown great potential for non-viral gene transfection via transient disruption of cell membrane (sonoporation). However, improvement of its efficiency has largely relied on empirical approaches without consistent and translatable results. The goal of this study is to develop a rational strategy based on new results obtained using novel experimental techniques and analysis to improve sonoporation gene transfection. We conducted experiments using targeted microbubbles that were attached to cell membrane to facilitate sonoporation. We quantified the dynamic activities of microbubbles exposed to pulsed ultrasound and the resulting sonoporation outcome and identified distinct regimes of characteristic microbubble behaviors: stable cavitation, coalescence and translation, and inertial cavitation. We found that inertial cavitation generated the highest rate of membrane poration. By establishing direct correlation of ultrasound-induced bubble activities with intracellular uptake and pore size, we designed a ramped pulse exposure scheme for optimizing microbubble excitation to improve sonoporation gene transfection. We implemented a novel sonoporation gene transfection system using an aqueous two phase system (ATPS) for efficient use of reagents and high throughput operation. Using plasmid coding for the green fluorescence protein (GFP), we achieved a sonoporation transfection efficiency in rate aortic smooth muscle cells (RASMCs) of 6.9% ± 2.2% (n = 9), comparable with lipofection (7.5% ± 0.8%, n = 9). Our results reveal characteristic microbubble behaviors responsible for sonoporation and demonstrated a rational strategy to improve sonoporation gene transfection. PMID:23770009

Establishment of a stable transfection system for genetic manipulation of Babesia gibsoni.

PubMed

Liu, Mingming; Adjou Moumouni, Paul Franck; Asada, Masahito; Hakimi, Hassan; Masatani, Tatsunori; Vudriko, Patrick; Lee, Seung-Hun; Kawazu, Shin-Ichiro; Yamagishi, Junya; Xuan, Xuenan

2018-04-23

Genetic manipulation techniques, such as transfection, have been previously reported in many protozoan parasites. In Babesia, stable transfection systems have only been established for bovine Babesia parasites. We recently reported a transient transfection system and the selection of promoter candidates for Babesia gibsoni. The establishment of a stable transfection system for B. gibsoni is considered to be urgent to improve our understanding of the basic biology of canine Babesia parasites for a better control of babesiosis. GFP-expressing parasites were observed by fluorescence microscopy as early as two weeks after drug selection, and consistently expressed GFP for more than 3 months without drug pressure. Genome integration was confirmed by PCR, sequencing and Southern blot analysis. We present the first successful establishment of a stable transfection system for B. gibsoni. This finding will facilitate functional analysis of Babesia genomes using genetic manipulation and will serve as a foundation for the development of tick-Babesia and host-Babesia infection models.

Bacteriophage Mediates Efficient Gene Transfer in Combination with Conventional Transfection Reagents

PubMed Central

Donnelly, Amanda; Yata, Teerapong; Bentayebi, Kaoutar; Suwan, Keittisak; Hajitou, Amin

2015-01-01

The development of commercially available transfection reagents for gene transfer applications has revolutionized the field of molecular biology and scientific research. However, the challenge remains in ensuring that they are efficient, safe, reproducible and cost effective. Bacteriophage (phage)-based viral vectors have the potential to be utilized for general gene transfer applications within research and industry. Yet, they require adaptations in order to enable them to efficiently enter cells and overcome mammalian cellular barriers, as they infect bacteria only; furthermore, limited progress has been made at increasing their efficiency. The production of a novel hybrid nanocomplex system consisting of two different nanomaterial systems, phage vectors and conventional transfection reagents, could overcome these limitations. Here we demonstrate that the combination of cationic lipids, cationic polymers or calcium phosphate with M13 bacteriophage-derived vectors, engineered to carry a mammalian transgene cassette, resulted in increased cellular attachment, entry and improved transgene expression in human cells. Moreover, addition of a targeting ligand into the nanocomplex system, through genetic engineering of the phage capsid further increased gene expression and was effective in a stable cell line generation application. Overall, this new hybrid nanocomplex system (i) provides enhanced phage-mediated gene transfer; (ii) is applicable for laboratory transfection processes and (iii) shows promise within industry for large-scale gene transfer applications. PMID:26670247

Bacteriophage Mediates Efficient Gene Transfer in Combination with Conventional Transfection Reagents.

PubMed

Donnelly, Amanda; Yata, Teerapong; Bentayebi, Kaoutar; Suwan, Keittisak; Hajitou, Amin

2015-12-08

The development of commercially available transfection reagents for gene transfer applications has revolutionized the field of molecular biology and scientific research. However, the challenge remains in ensuring that they are efficient, safe, reproducible and cost effective. Bacteriophage (phage)-based viral vectors have the potential to be utilized for general gene transfer applications within research and industry. Yet, they require adaptations in order to enable them to efficiently enter cells and overcome mammalian cellular barriers, as they infect bacteria only; furthermore, limited progress has been made at increasing their efficiency. The production of a novel hybrid nanocomplex system consisting of two different nanomaterial systems, phage vectors and conventional transfection reagents, could overcome these limitations. Here we demonstrate that the combination of cationic lipids, cationic polymers or calcium phosphate with M13 bacteriophage-derived vectors, engineered to carry a mammalian transgene cassette, resulted in increased cellular attachment, entry and improved transgene expression in human cells. Moreover, addition of a targeting ligand into the nanocomplex system, through genetic engineering of the phage capsid further increased gene expression and was effective in a stable cell line generation application. Overall, this new hybrid nanocomplex system (i) provides enhanced phage-mediated gene transfer; (ii) is applicable for laboratory transfection processes and (iii) shows promise within industry for large-scale gene transfer applications.

Differences in the expression of endogenous efflux transporters in MDR1-transfected versus wildtype cell lines affect P-glycoprotein mediated drug transport

PubMed Central

Kuteykin-Teplyakov, Konstantin; Luna-Tortós, Carlos; Ambroziak, Kamila; Löscher, Wolfgang

2010-01-01

Background and purpose: P-glycoprotein (Pgp) efflux assays are widely used to identify Pgp substrates. The kidney cell lines Madin-Darby canine kidney (MDCK)-II and LLC-PK1, transfected with human MDR1 (ABCB1) are used to provide recombinant models of drug transport. Endogenous transporters in these cells may contribute to the activities of recombinant transporters, so that drug transport in MDR1-transfected cells is often corrected for the transport obtained in parental (wildtype) cells. However, expression of endogenous transporters may vary between transfected and wildtype cells, so that this correction may cause erroneous data. Here, we have measured the expression of endogenous efflux transporters in transfected and wildtype MDCK-II or LLC cells and the consequences for Pgp-mediated drug transport. Experimental approach: Using quantitative real-time RT-PCR, we determined the expression of endogenous Mdr1 mRNA and other efflux transporters in wildtype and MDR1-transfected MDCK-II and LLC cells. Transcellular transport was measured with the test substrate vinblastine. Key results: In MDR1-transfected MDCK cells, expression of endogenous (canine) Mdr1 and Mrp2 (Abcc2) mRNA was markedly lower than in wildtype cells, whereas MDR1-transfected LLC cells exhibited comparable Mdr1 but strikingly higher Mrp2 mRNA levels than wildtype cells. As a consequence, transport of vinblastine by human Pgp in efflux experiments was markedly underestimated when transport in MDR1-transfected MDCK cells was corrected for transport obtained in wildtype cells. This problem did not occur in LLC cells. Conclusions and implications: Differences in the expression of endogenous efflux transporters between transfected and wildtype MDCK cells provide a potential bias for in vitro studies on Pgp-mediated drug transport. PMID:20590635

Guide RNA selection for CRISPR-Cas9 transfections in Plasmodium falciparum.

PubMed

Ribeiro, Jose M; Garriga, Meera; Potchen, Nicole; Crater, Anna K; Gupta, Ankit; Ito, Daisuke; Desai, Sanjay A

2018-06-12

CRISPR-Cas9 mediated genome editing is addressing key limitations in the transfection of malaria parasites. While this method has already simplified the needed molecular cloning and reduced the time required to generate mutants in the human pathogen Plasmodium falciparum, optimal selection of required guide RNAs and guidelines for successful transfections have not been well characterized, leading workers to use time-consuming trial and error approaches. We used a genome-wide computational approach to create a comprehensive and publicly accessible database of possible guide RNA sequences in the P. falciparum genome. For each guide, we report on-target efficiency and specificity scores as well as information about the genomic site relevant to optimal design of CRISPR-Cas9 transfections to modify, disrupt, or conditionally knockdown any gene. As many antimalarial drug and vaccine targets are encoded by multigene families, we also developed a new paralog specificity score that should facilitate modification of either a single family member of interest or multiple paralogs that serve overlapping roles. Finally, we tabulated features of successful transfections in our laboratory, providing broadly useful guidelines for parasite transfections. Molecular studies aimed at understanding parasite biology or characterizing drug and vaccine targets in P. falciparum should be facilitated by this comprehensive database. Published by Elsevier Ltd.

[Transfection of hBcl-2 gene protects the liver against ischemia/reperfusion injury in rats during liver transplantation].

PubMed

Liu, Ji-tong; Liu, Jing-shi; Jiang, Jin-yu; Zhou, Li-xue; Liang, Gang; Li, Yan-chun

2010-12-01

To study the effect of hBcl-2 gene transfer on rat liver against ischemia-reperfusion injury, and explore the feasibility of this approach to reduce ischemia-reperfusion injury in liver transplantation. We constructed the replication-deficient recombinant adenoviruses Adv-EGFP and Adv-Bcl-2 and transfected them into 293 cells and packaged into adenovirus particles for amplification and purification. The empty plasmid vector virus was constructed similarly. Male SD rats were randomized into Adv-Bcl-2-transfected group, Adv-EGFP-transfected group, ischemia-reperfusion group, and sham-operated group, and liver allograft transplantation model was established by sleeve method. In the transfected groups, the recombinant viruses were administered by perfusion through the portal vein, and the ischemia-reperfusion and sham-operated groups received no treatment. Real-time quantitative PCR and Western blotting were used to detect the mRNA and protein expressions of bcl-2 in the liver tissue of each group, and at 0, 60 and 180 min after reperfusion, serum AST, LDH, and MDA levels were measured. Histological changes of the liver cells were evaluated by HE staining. Bcl-2 mRNA and protein expressions in Adv-Bcl-2-transfected group, as compared with those in Adv-EGFP-transfected group and control group, were significantly increased (P<0.01); the serum levels of AST, LDH and MDA in Adv-Bcl-2-transfected group were significantly lower than those of Adv-EGFP-transfected group and ischemia-reperfusion group (P<0.05 or 0.01). Compared with the sham-operated group, Adv-Bcl-2 treatment group showed lessened edema and vacuolar degeneration of the liver cells without patches or spots of necrosis. In ischemia-reperfusion and Adv-EGFP group, HE staining revealed hepatic lobular destruction and extensive liver cell swelling, enlargement, vacuolar degeneration, edema and occasional focal necrosis. Adv-Bcl-2 transfection can induce the expression of bcl-2 gene to reduce ischemia

Genomic Knockout of Endogenous Canine P-Glycoprotein in Wild-Type, Human P-Glycoprotein and Human BCRP Transfected MDCKII Cell Lines by Zinc Finger Nucleases.

PubMed

Gartzke, Dominik; Delzer, Jürgen; Laplanche, Loic; Uchida, Yasuo; Hoshi, Yutaro; Tachikawa, Masanori; Terasaki, Tetsuya; Sydor, Jens; Fricker, Gert

2015-06-01

To investigate whether it is possible to specifically suppress the expression and function of endogenous canine P-glycoprotein (cPgp) in Madin-Darby canine kidney type II cells (MDCKII) transfected with hPGP and breast cancer resistance protein (hBCRP) by zinc finger nuclease (ZFN) producing sequence specific DNA double strand breaks. Wild-type, hPGP-transfected, and hBCRP-transfected MDCKII cells were transfected with ZFN targeting for cPgp. Net efflux ratios (NER) of Pgp and Bcrp substrates were determined by dividing efflux ratios (basal-to-apical / apical-to-basal) in over-expressing cell monolayers by those in wild-type ones. From ZFN-transfected cells, cell populations (ko-cells) showing knockout of cPgp were selected based on genotyping by PCR. qRT-PCR analysis showed the significant knock-downs of cPgp and interestingly also cMrp2 expressions. Specific knock-downs of protein expression for cPgp were shown by western blotting and quantitative targeted absolute proteomics. Endogenous canine Bcrp proteins were not detected. For PGP-transfected cells, NERs of 5 Pgp substrates in ko-cells were significantly greater than those in parental cells not transfected with ZFN. Similar result was obtained for BCRP-transfected cells with a dual Pgp and Bcrp substrate. Specific efflux mediated by hPGP or hBCRP can be determined with MDCKII cells where cPgp has been knocked out by ZFN.

Non-Viral Transfection Methods Optimized for Gene Delivery to a Lung Cancer Cell Line

PubMed Central

Salimzadeh, Loghman; Jaberipour, Mansooreh; Hosseini, Ahmad; Ghaderi, Abbas

2013-01-01

Background Mehr-80 is a newly established adherent human large cell lung cancer cell line that has not been transfected until now. This study aims to define the optimal transfection conditions and effects of some critical elements for enhancing gene delivery to this cell line by utilizing different non-viral transfection Procedures. Methods In the current study, calcium phosphate (CaP), DEAE-dextran, superfect, electroporation and lipofection transfection methods were used to optimize delivery of a plasmid construct that expressed Green Fluorescent Protein (GFP). Transgene expression was detected by fluorescent microscopy and flowcytometry. Toxicities of the methods were estimated by trypan blue staining. In order to evaluate the density of the transfected gene, we used a plasmid construct that expressed the Stromal cell-Derived Factor-1 (SDF-1) gene and measured its expression by real-time PCR. Results Mean levels of GFP-expressing cells 48 hr after transfection were 8.4% (CaP), 8.2% (DEAE-dextran), 4.9% (superfect), 34.1% (electroporation), and 40.1% (lipofection). Lipofection had the highest intense SDF-1 expression of the analyzed methods. Conclusion This study has shown that the lipofection and electroporation methods were more efficient at gene delivery to Mehr-80 cells. The quantity of DNA per transfection, reagent concentration, and incubation time were identified as essential factors for successful transfection in all of the studied methods. PMID:23799175

Large-Scale Transient Transfection of Suspension Mammalian Cells for VLP Production.

PubMed

Cervera, Laura; Kamen, Amine A

2018-01-01

Large-scale transient transfection of mammalian cell suspension cultures enables the production of biological products in sufficient quantity and under stringent quality attributes to perform accelerated in vitro evaluations and has the potential to support preclinical or even clinical studies. Here we describe the methodology to produce VLPs in a 3L bioreactor, using suspension HEK 293 cells and PEIPro as a transfection reagent. Cells are grown in the bioreactor to 1 × 10 6 cells/mL and transfected with a plasmid DNA-PEI complex at a ratio of 1:2. Dissolved oxygen and pH are controlled and are online monitored during the production phase and cell growth and viability can be measured off line taking samples from the bioreactor. If the product is labeled with a fluorescent marker, transfection efficiency can be also assessed using flow cytometry analysis. Typically, the production phase lasts between 48 and 96 h until the product is harvested.

Targeted nanobubbles in low-frequency ultrasound-mediated gene transfection and growth inhibition of hepatocellular carcinoma cells.

PubMed

Wu, Bolin; Qiao, Qiang; Han, Xue; Jing, Hui; Zhang, Hao; Liang, Hongjian; Cheng, Wen

2016-09-01

The use of SonoVue combined with ultrasound exposure increases the transfection efficiency of short interfering RNA (siRNA). The objective of this study was to prepare targeted nanobubbles (TNB) conjugated with NET-1 siRNA and an antibody GPC3 to direct nanobubbles to hepatocellular carcinoma cells. SMMC-7721 human hepatocellular carcinoma cells were treated with six different groups. The transfection efficiency and cellular apoptosis were measured by flow cytometry. The protein and messenger RNA (mRNA) expression were measured by Western blot and quantitative real-time PCR, respectively. The migration and invasion potential of the cells were determined by Transwell analysis. The results show that US-guided siRNA-TNB transfection effectively enhanced gene silencing. In summary, siRNA-TNB may be an effective delivery vector to mediate highly effective RNA interference in tumor treatment.

Transfection efficiency of chitosan and thiolated chitosan in retinal pigment epithelium cells: A comparative study

PubMed Central

Oliveira, Ana V.; Silva, Andreia P.; Bitoque, Diogo B.; Silva, Gabriela A.; Rosa da Costa, Ana M.

2013-01-01

OBJECTIVE: Gene therapy relies on efficient vector for a therapeutic effect. Efficient non-viral vectors are sought as an alternative to viral vectors. Chitosan, a cationic polymer, has been studied for its gene delivery potential. In this work, disulfide bond containing groups were covalently added to chitosan to improve the transfection efficiency. These bonds can be cleaved by cytoplasmic glutathione, thus, releasing the DNA load more efficiently. MATERIALS AND METHODS: Chitosan and thiolated chitosan nanoparticles (NPs) were prepared in order to obtain a NH3+:PO4− ratio of 5:1 and characterized for plasmid DNA complexation and release efficiency. Cytotoxicity and gene delivery studies were carried out on retinal pigment epithelial cells. RESULTS: In this work, we show that chitosan was effectively modified to incorporate a disulfide bond. The transfection efficiency of chitosan and thiolated chitosan varied according to the cell line used, however, thiolation did not seem to significantly improve transfection efficiency. CONCLUSION: The apparent lack of improvement in transfection efficiency of the thiolated chitosan NPs is most likely due to its size increase and charge inversion relatively to chitosan. Therefore, for retinal cells, thiolated chitosan does not seem to constitute an efficient strategy for gene delivery. PMID:23833516

Enhancement of reverse transfection efficiency by combining stimulated DNA surface desorption and electroporation

NASA Astrophysics Data System (ADS)

Creasey, Rhiannon; Hook, Andrew; Thissen, Helmut; Voelcker, Nicolas H.

2007-12-01

Transfection cell microarrays (TCMs) are a high-throughput, miniaturised cell-culture system utilising reverse transfection, in which cells are seeded onto a DNA array resulting in localised regions of transfected cells. TCMs are useful for the analysis of gene expression, and can be used to identify genes involved in many cellular processes. This is of significant interest in fields such as tissue engineering, diagnostic screening, and drug testing [1, 2]. Low transfection efficiency has so far limited the application and utility of this technique. Recently, the transfection efficiency of TCMs was improved by an application of a high voltage for a short period of time to the DNA array resulting in the electroporation of cells attached to the surface [3, 4]. Furthermore, application of a low voltage for a longer period of time to the DNA array was shown to improve the transfection efficiency by stimulating the desorption of attached DNA, increasing the concentration of DNA available for cellular uptake [5]. In the present study, the optimisation of the uptake of adsorbed DNA vectors by adherent cells, utilising a voltage bias without compromising cell viability was investigated. This was achieved by depositing negatively charged DNA plasmids onto a positively charged allylamine plasma polymer (ALAPP) layer deposited on highly doped p-type silicon wafers either using a pipettor or a microarray contact printer. Surface-dependant human embryonic kidney (HEK 293 line) cells were cultured onto the DNA vector loaded ALAPP spots and the plasmid transfection events were detected by fluorescence microscopy. Cell viability assays, including fluorescein diacetate (FDA) / Hoechst DNA labelling, were carried out to determine the number of live adherent cells before and after application of a voltage. A protocol was developed to screen for voltage biases and exposure times in order to optimise transfection efficiency and cell viability. Cross-contamination between the microarray

Enhanced plasmid DNA utilization in transiently transfected CHO-DG44 cells in the presence of polar solvents.

PubMed

Rajendra, Yashas; Balasubramanian, Sowmya; Kiseljak, Divor; Baldi, Lucia; Wurm, Florian M; Hacker, David L

2015-01-01

Although the protein yields from transient gene expression (TGE) with Chinese hamster ovary (CHO) cells have recently improved, the amount of plasmid DNA (pDNA) needed for transfection remains relatively high. We describe a strategy to reduce the pDNA amount by transfecting CHO-DG44 cells with 0.06 μg pDNA/10(6) cells (10% of the optimal amount) in the presence of nonspecific (filler) DNA and various polar solvents including dimethylsufoxide, dimethyl formamide, acetonitrile, dimethyl acetamide (DMA), and hexamethyl phosphoramide (HMP). All of the polar solvents with the exception of HMP increased the production of a recombinant antibody in comparison to the untreated control transfection. In the presence of 0.25% DMA, the antibody yield in a 7-day batch culture was 500 mg/L. This was fourfold higher than the yield from the untreated control transfection. Mechanistic studies revealed that the polar solvents did not affect polyethylenimine-mediated pDNA delivery into cells or nuclei. The steady-state transgene mRNA level was elevated in the presence of each of the polar solvents tested, while the transgene mRNA half-life remained the same. These results indicated that the polar solvents enhanced transgene transcription. When screening a panel of recombinant antibodies and Fc-fusion proteins for production in the presence of the polar solvents, the highest increase in yield was observed following DMA addition for 11 of the 12 proteins. These results are expected to enhance the applicability of high-yielding TGE processes with CHO-DG44 cells by decreasing the amount of pDNA required for transfection. © 2015 American Institute of Chemical Engineers.

In vitro expression of erythropoietin by transfected human mesenchymal stromal cells.

PubMed

Mok, P-L; Cheong, S-K; Leong, C-F; Othman, A

2008-01-01

Mesenchymal stromal cells (MSC) are pluripotent progenitor cells that can be found in human bone marrow (BM). These cells have low immunogenicity and could suppress alloreactive T-cell responses. In the current study, MSC were tested for their capacity to carry and deliver the erythropoietin (EPO) gene in vitro. Expanded BM MSC was transfected with EPO-encoded plasmid pMCV1.2 and EPO-encoded MIDGE (minimalistic immunologically defined gene expression) vector by electroporation. The expressed EPO was used to induce hematopoietic stem cells (HSC) into erythroid colonies. The results showed that the MIDGE vector was more effective and stable than the plasmid (pMCV1.2) in delivering EPO gene into MSC. The supernatants containing EPO obtained from the transfected cell culture were able to induce the differentiation of HSC into erythroid colonies. MSC hold promise as a cell factory for the production of biologic molecules, and MIDGE vector is more effective and stable than the plasmid in nucleofection involving the EPO gene.

Effect of biodegradability on CXCR4 antagonism, transfection efficacy and antimetastatic activity of polymeric Plerixafor

PubMed Central

Li, Jing; Oupický, David

2014-01-01

Chemokine receptor CXCR4 and its sole ligand SDF-1 are key players in regulating cancer cell invasion and metastasis. Plerixafor (AMD3100) is a small-molecule CXCR4 antagonist that prevents binding of SDF-1 to CXCR4 and has potential in prevention of cancer metastasis. This study investigates the influence of biodegradability of a recently reported polymeric Plerixafor (PAMD) on CXCR4 antagonism, antimetastatic activity, and transfection efficacy of PAMD polyplexes with plasmid DNA. We show that PAMD exhibits CXCR4 antagonism and inhibition of cancer cell invasion in vitro regardless of its biodegradability. Biodegradable PAMD showed considerably enhanced transfection efficiency and decreased cytotoxicity when compared with the non-degradable PAMD. Despite similar CXCR4 antagonism in vitro, only biodegradable PAMD displayed antimetastatic activity in experimental lung metastasis model in vivo. PMID:24726746

Transfection using hydroxyapatite nanoparticles in the inner ear via an intact round window membrane in chinchilla

NASA Astrophysics Data System (ADS)

Wu, Xuewen; Ding, Dalian; Jiang, Haiyan; Xing, Xiaowei; Huang, Suping; Liu, Hong; Chen, Zhedong; Sun, Hong

2012-01-01

Hydroxyapatite nanoparticles (nHAT) are known to have excellent biocompatibility, and have attracted increasing attention as new candidates of non-viral vectors for gene therapy. In our previous studies, nHAT carrying a therapeutic gene and a reporter gene were successfully transfected into the spiral ganglion neurons in the inner ear of guinea pigs in vivo as well as in the cultured cell lines, although the transfection efficiencies were never higher than 30%. In this study, the surface modification of nHAT with polyethylenimine (PEI) was made (PEI-nHAT, diameter = 73.09 ± 27.32 nm) and a recombinant plasmid carrying enhanced green fluorescent protein (EGFP) gene and neurotrophin-3 (NT-3) gene was constructed as pEGFPC2-NT3. The PEI modified nHAT and the recombinant plasmid was then connected to form the nHAT-based vector-gene complex (PEI-nHAT-pEGFPC2-NT3). This complex was then placed onto the intact round window membranes of the chinchillas for inner ear transfection. Auditory brainstem response (ABR) was tested to evaluate auditory function. Green fluorescence of EGFP was observed using confocal microscopy 48 h after administering vector-gene complexes. There was no significant threshold shift in tone burst-evoked ABR at any tested frequency. Abundant, condensed green fluorescence was found in dark cells on both sides of the crista and around the macula of the utricle. Scattered EGFP signals were also detected in vestibular hair cells, some Schwann cells in the cochlear spiral ganglion region, some outer pillar cells in the organ of Corti, and a few cells in the stria vascularis. The density of green fluorescence-marked cells was obviously higher in the vestibular dark cell area than in other areas of the inner ear, suggesting that vestibular dark cells may have the ability to actively engulf the nHAT-based vector-gene complexes. Considering the high transfection efficiency in the vestibular system, PEI-nHAT may be a potential vector for gene therapy of inner

Transfection Studies with Colloidal Systems Containing Highly Purified Bipolar Tetraether Lipids from Sulfolobus acidocaldarius.

PubMed

Engelhardt, Konrad H; Pinnapireddy, Shashank Reddy; Baghdan, Elias; Jedelská, Jarmila; Bakowsky, Udo

2017-01-01

Lipid vectors are commonly used to facilitate the transfer of nucleic acids into mammalian cells. In this study, two fractions of tetraether lipids from the archaea Sulfolobus acidocaldarius were extracted and purified using different methods. The purified lipid fractions polar lipid fraction E (PLFE) and hydrolysed glycerol-dialkyl-nonitol tetraether (hGDNT) differ in their structures, charge, size, and miscibility from conventional lipids. Liposomes were prepared by mixing tetraether lipids with cholesterol (CH) and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) resulting in stable vectors for gene delivery. Lipoplexes were prepared by complexation of liposomes with a luciferase expressing plasmid (pCMV-luc) at certain nitrogen-to-phosphorus (N/P) ratios and optimised for the transient transfection of ovarian adenocarcinoma cells (SK-OV-3). Complexation efficacy was investigated by gel-red fluorescence assay. Biophysical properties, like size, surface charge, and morphology, were investigated by differential light scattering (DLS), atomic force microscopy (AFM), and scanning electron microscopy (Cryo-SEM), respectively, revealing structural differences between liposomes and lipoplexes. A range of stable transfecting agents containing tetraether lipids were obtained by incorporating 5 mol% of tetraether lipids. Lipoplexes showed a decrease in free gel-red with increasing N/P ratios indicating efficient incorporation of plasmid DNA (pDNA) and remarkable stability. Transfection experiments of the lipoplexes revealed successful and superior transfection of SK-OV-3 cell line compared to the commercially available DOTAP and branched polyethyleneimine (25 kDa bPEI).

Transfection Studies with Colloidal Systems Containing Highly Purified Bipolar Tetraether Lipids from Sulfolobus acidocaldarius

PubMed Central

Pinnapireddy, Shashank Reddy; Baghdan, Elias; Jedelská, Jarmila

2017-01-01

Lipid vectors are commonly used to facilitate the transfer of nucleic acids into mammalian cells. In this study, two fractions of tetraether lipids from the archaea Sulfolobus acidocaldarius were extracted and purified using different methods. The purified lipid fractions polar lipid fraction E (PLFE) and hydrolysed glycerol-dialkyl-nonitol tetraether (hGDNT) differ in their structures, charge, size, and miscibility from conventional lipids. Liposomes were prepared by mixing tetraether lipids with cholesterol (CH) and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) resulting in stable vectors for gene delivery. Lipoplexes were prepared by complexation of liposomes with a luciferase expressing plasmid (pCMV-luc) at certain nitrogen-to-phosphorus (N/P) ratios and optimised for the transient transfection of ovarian adenocarcinoma cells (SK-OV-3). Complexation efficacy was investigated by gel-red fluorescence assay. Biophysical properties, like size, surface charge, and morphology, were investigated by differential light scattering (DLS), atomic force microscopy (AFM), and scanning electron microscopy (Cryo-SEM), respectively, revealing structural differences between liposomes and lipoplexes. A range of stable transfecting agents containing tetraether lipids were obtained by incorporating 5 mol% of tetraether lipids. Lipoplexes showed a decrease in free gel-red with increasing N/P ratios indicating efficient incorporation of plasmid DNA (pDNA) and remarkable stability. Transfection experiments of the lipoplexes revealed successful and superior transfection of SK-OV-3 cell line compared to the commercially available DOTAP and branched polyethyleneimine (25 kDa bPEI). PMID:28239294

Minimally-Invasive Gene Transfection by Chemical and Physical Interaction of Atmospheric Pressure Plasma Flow

NASA Astrophysics Data System (ADS)

Kaneko, Toshiro

2014-10-01

Non-equilibrium atmospheric pressure plasma irradiated to the living-cell is investigated for medical applications such as gene transfection, which is expected to play an important role in molecular biology, gene therapy, and creation of induced pluripotent stem (iPS) cells. However, the conventional gene transfection using the plasma has some problems that the cell viability is low and the genes cannot be transferred into some specific lipid cells, which is attributed to the unknown mechanism of the gene transfection using the plasma. Therefore, the time-controlled atmospheric pressure plasma flow is generated and irradiated to the living-cell suspended solution for clarifying the transfection mechanism toward developing highly-efficient and minimally- invasive gene transfection system. In this experiment, fluorescent dye YOYO-1 is used as the simulated gene and LIVE/DEAD Stain is simultaneously used for cell viability assay. By the fluorescence image, the transfection efficiency is calculated as the ratio of the number of transferred and surviving cells to total cell count. It is clarified that the transfection efficiency is significantly increased by the short-time (<4 sec) and short-distance (<40 mm) plasma irradiation, and the high transfection efficiency of 53% is realized together with the high cell viability (>90%). This result indicates that the physical effects such as the electric field caused by the charged particles arriving at the surface of the cell membrane, and chemical effects associated with plasma-activated products in solution act synergistically to enhance the cell-membrane transport with low-damage. This work was supported by JSPS KAKENHI Grant Number 24108004.

Targeted surface expression of an exogenous antigen in stably transfected babesia bovis

USDA-ARS?s Scientific Manuscript database

Babesia bovis is a tick-borne intraerythocytic protozoan responsible for acute disease in cattle which can be controlled by vaccination with attenuated B. bovis strains. Emerging B. bovis transfection technologies may increase the usefulness of these live vaccines. Here we propose using transfected ...

[Construction of injectable tissue engineered adipose tissue with fibrin glue scaffold and human adipose-derived stem cells transfected by lentivirus vector expressing hepatocyte growth factor].

PubMed

Zhu, Yuanzheng; Yi, Yangyan; Yang, Shuifa; Zhang, Jing; Wu, Shu; Wang, Zhaohui

2017-09-01

-born tissue in the transfected group [(32.30±4.06) mg] was significantly heavier than that of the untransfected group [(25.27±3.94) mg] ( t =3.929, P =0.001). The mature adipose cells in the transfected group [(126.93±5.36) cells/field] were significantly more than that in the untransfected group [(71.36±4.52) cells/field] ( t =30.700, P =0.000). Under fluorescence microscopy, some of the single cell adipocytes showed a network of green fluorescence, indicating the presence of GFP labeled exogenous hADSCs in the tissue. The vascular density of new-born tissue of the transfected group [(16.37±2.76)/field] was significantly higher than that of the untransfected group [(9.13±1.68)/field] ( t =8.678, P =0.000). The hADSCs extracted from the lipid part after liposuction can be used as seed cells. After HGF-GFP-LVs transfection and adipose induction, the hADSCs combined with injectable fibrin glue scaffold can construct mature adipose tissue in vivo , which may stimulate angiogenesis, and improve retention rate of new-born tissue.

A novel rapid and reproducible flow cytometric method for optimization of transfection efficiency in cells

PubMed Central

Homann, Stefanie; Hofmann, Christian; Gorin, Aleksandr M.; Nguyen, Huy Cong Xuan; Huynh, Diana; Hamid, Phillip; Maithel, Neil; Yacoubian, Vahe; Mu, Wenli; Kossyvakis, Athanasios; Sen Roy, Shubhendu; Yang, Otto Orlean

2017-01-01

Transfection is one of the most frequently used techniques in molecular biology that is also applicable for gene therapy studies in humans. One of the biggest challenges to investigate the protein function and interaction in gene therapy studies is to have reliable monospecific detection reagents, particularly antibodies, for all human gene products. Thus, a reliable method that can optimize transfection efficiency based on not only expression of the target protein of interest but also the uptake of the nucleic acid plasmid, can be an important tool in molecular biology. Here, we present a simple, rapid and robust flow cytometric method that can be used as a tool to optimize transfection efficiency at the single cell level while overcoming limitations of prior established methods that quantify transfection efficiency. By using optimized ratios of transfection reagent and a nucleic acid (DNA or RNA) vector directly labeled with a fluorochrome, this method can be used as a tool to simultaneously quantify cellular toxicity of different transfection reagents, the amount of nucleic acid plasmid that cells have taken up during transfection as well as the amount of the encoded expressed protein. Finally, we demonstrate that this method is reproducible, can be standardized and can reliably and rapidly quantify transfection efficiency, reducing assay costs and increasing throughput while increasing data robustness. PMID:28863132

Optimized pulmonary gene transfection in mice by spray-freeze dried powder inhalation.

PubMed

Mohri, Kohta; Okuda, Tomoyuki; Mori, Asami; Danjo, Kazumi; Okamoto, Hirokazu

2010-06-01

Spray-freeze drying (SFD) is an attractive technique to prepare highly porous dry powders for inhalation. However, there have been few reports of its application to dry powder inhalers (DPIs). Therefore, in this study, we prepared dry plasmid DNA (pDNA) powders with different molecular ratios of chitosan to pDNA (N/P ratios) by SFD. All the pDNA powders were spherical and highly porous, with particles approximately 20-40microm in geometric diameter. The morphology changed little with the alteration of the N/P ratio. On electrophoresis, a band of linear pDNA was detected in the preparation without chitosan, suggesting the destabilization of pDNA through SFD. However, the addition of chitosan protected pDNA from destabilization. Moreover, the pDNA powders were evaluated for pulmonary gene transfection efficiency using an in vivo dual imaging technique for gene DPIs developed previously. Maximum gene expression was observed at 9-12h following pulmonary administration of the powders into mice. The powder with the N/P ratio of 10 had the highest gene transfection efficiency. A higher affinity of chitosan for pDNA and a smaller (approximately 100nm) pDNA/chitosan complex (N/Pf10) were found at pH 6.5 (in lung) than at pH 7.4 (in physiological conditions), suggesting that the effective compaction of pDNA by chitosan at the N/P ratio of 10 at pH 6.5 contributes to the gene transfection efficiency in the lung. These results suggest inhalable dry pDNA powders with chitosan prepared by SFD to be a suitable formulation for pulmonary gene therapy. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Ultrasonic destruction of albumin microbubbles enhances gene transfection and expression in cardiac myocytes.

PubMed

Wang, Guo-zhong; Liu, Jing-hua; Lü, Shu-zheng; Lü, Yun; Guo, Cheng-jun; Zhao, Dong-hui; Fang, Dong-ping; He, Dong-fang; Zhou, Yuan; Ge, Chang-jiang

2011-05-01

It has been proven that ultrasonic destruction of microbubbles can enhance gene transfection efficiency into the noncardiac cells, but there are few reports about cardiac myocytes. Moreover, the exact mechanisms are not yet clear; whether the characteristic of microbubbles can affect the gene transfection efficiency or not is still controversial. This study was designed to investigate whether the ultrasound destruction of gene-loaded microbubbles could enhance the plasmids carried reporter gene transfection in primary cultured myocardial cell, and evaluate the effects of microbubbles characteristics on the transgene expression in cardiac myocytes. The β-galactosidase plasmids attached to the two types of microbubbles, air-contained sonicated dextrose albumin (ASDA) and perfluoropropane-exposed sonicated dextrose albumin (PESDA) were prepared. The gene transfection into cardiac myocytes was performed in vitro by naked plasmids, ultrasound exposure, ultrasonic destruction of gene-loaded microbubbles and calcium phosphate precipitation, and then the gene expression and cell viability were analyzed. The ultrasonic destruction of gene-loaded microbubbles enhanced gene expression in cardiac myocytes compared with naked plasmid transfection ((51.95 ± 2.41) U/g or (29.28 ± 3.65) U/g vs. (0.84 ± 0.21) U/g, P < 0.01), and ultrasonic destruction PESDA resulted in more significant gene expression than ASDA ((51.95 ± 2.41) U/g vs. (29.28 ± 3.65) U/g, P < 0.05). Ultrasonic destruction of microbubbles during calcium phosphate precipitation gene transfection enhanced β-galactosidase activity nearly 8-fold compared with calcium phosphate precipitation gene transfection alone ((111.35 ± 11.21) U/g protein vs. (14.13 ± 2.58) U/g protein, P < 0.01). Even 6 hours after calcium phosphate precipitation gene transfection, ultrasound-mediated microbubbles destruction resulted in more intense gene expression ((35.63 ± 7.65) U/g vs. (14.13 ± 2.58) U/g, P < 0.05). Ultrasonic

Intracellular ROS mediates gas plasma-facilitated cellular transfection in 2D and 3D cultures

PubMed Central

Xu, Dehui; Wang, Biqing; Xu, Yujing; Chen, Zeyu; Cui, Qinjie; Yang, Yanjie; Chen, Hailan; Kong, Michael G.

2016-01-01

This study reports the potential of cold atmospheric plasma (CAP) as a versatile tool for delivering oligonucleotides into mammalian cells. Compared to lipofection and electroporation methods, plasma transfection showed a better uptake efficiency and less cell death in the transfection of oligonucleotides. We demonstrated that the level of extracellular aqueous reactive oxygen species (ROS) produced by gas plasma is correlated with the uptake efficiency and that this is achieved through an increase of intracellular ROS levels and the resulting increase in cell membrane permeability. This finding was supported by the use of ROS scavengers, which reduced CAP-based uptake efficiency. In addition, we found that cold atmospheric plasma could transfer oligonucleotides such as siRNA and miRNA into cells even in 3D cultures, thus suggesting the potential for unique applications of CAP beyond those provided by standard transfection techniques. Together, our results suggest that cold plasma might provide an efficient technique for the delivery of siRNA and miRNA in 2D and 3D culture models. PMID:27296089

Single Cell Transfection through Precise Microinjection with Quantitatively Controlled Injection Volumes

NASA Astrophysics Data System (ADS)

Chow, Yu Ting; Chen, Shuxun; Wang, Ran; Liu, Chichi; Kong, Chi-Wing; Li, Ronald A.; Cheng, Shuk Han; Sun, Dong

2016-04-01

Cell transfection is a technique wherein foreign genetic molecules are delivered into cells. To elucidate distinct responses during cell genetic modification, methods to achieve transfection at the single-cell level are of great value. Herein, we developed an automated micropipette-based quantitative microinjection technology that can deliver precise amounts of materials into cells. The developed microinjection system achieved precise single-cell microinjection by pre-patterning cells in an array and controlling the amount of substance delivered based on injection pressure and time. The precision of the proposed injection technique was examined by comparing the fluorescence intensities of fluorescent dye droplets with a standard concentration and water droplets with a known injection amount of the dye in oil. Injection of synthetic modified mRNA (modRNA) encoding green fluorescence proteins or a cocktail of plasmids encoding green and red fluorescence proteins into human foreskin fibroblast cells demonstrated that the resulting green fluorescence intensity or green/red fluorescence intensity ratio were well correlated with the amount of genetic material injected into the cells. Single-cell transfection via the developed microinjection technique will be of particular use in cases where cell transfection is challenging and genetically modified of selected cells are desired.

Single Cell Transfection through Precise Microinjection with Quantitatively Controlled Injection Volumes.

PubMed

Chow, Yu Ting; Chen, Shuxun; Wang, Ran; Liu, Chichi; Kong, Chi-Wing; Li, Ronald A; Cheng, Shuk Han; Sun, Dong

2016-04-12

Cell transfection is a technique wherein foreign genetic molecules are delivered into cells. To elucidate distinct responses during cell genetic modification, methods to achieve transfection at the single-cell level are of great value. Herein, we developed an automated micropipette-based quantitative microinjection technology that can deliver precise amounts of materials into cells. The developed microinjection system achieved precise single-cell microinjection by pre-patterning cells in an array and controlling the amount of substance delivered based on injection pressure and time. The precision of the proposed injection technique was examined by comparing the fluorescence intensities of fluorescent dye droplets with a standard concentration and water droplets with a known injection amount of the dye in oil. Injection of synthetic modified mRNA (modRNA) encoding green fluorescence proteins or a cocktail of plasmids encoding green and red fluorescence proteins into human foreskin fibroblast cells demonstrated that the resulting green fluorescence intensity or green/red fluorescence intensity ratio were well correlated with the amount of genetic material injected into the cells. Single-cell transfection via the developed microinjection technique will be of particular use in cases where cell transfection is challenging and genetically modified of selected cells are desired.

Single histidine residue in head-group region is sufficient to impart remarkable gene transfection properties to cationic lipids: evidence for histidine-mediated membrane fusion at acidic pH.

PubMed

Kumar, V V; Pichon, C; Refregiers, M; Guerin, B; Midoux, P; Chaudhuri, A

2003-08-01

Presence of endosome-disrupting multiple histidine functionalities in the molecular architecture of cationic polymers, such as polylysine, has previously been demonstrated to significantly enhance their in vitro gene delivery efficiencies. Towards harnessing improved transfection property through covalent grafting of endosome-disrupting single histidine functionality in the molecular structure of cationic lipids, herein, we report on the design, the synthesis and the transfection efficiency of two novel nonglycerol-based histidylated cationic amphiphiles. We found that L-histidine-(N,N-di-n-hexadecylamine)ethylamide (lipid 1) and L-histidine-(N,N-di-n-hexadecylamine,-N-methyl)ethylamide (lipid 2) in combination with cholesterol gave efficient transfections into various cell lines. The transfection efficiency of Chol/lipid 1 lipoplexes into HepG2 cells was two order of magnitude higher than that of FuGENE(TM)6 and DC-Chol lipoplexes, whereas it was similar into A549, 293T7 and HeLa cells. A better efficiency was obtained with Chol/lipid 2 lipoplexes when using the cytosolic luciferase expression vector (pT7Luc) under the control of the bacterial T7 promoter. Membrane fusion activity measurements using fluorescence resonance energy transfer (FRET) technique showed that the histidine head-groups of Chol/lipid 1 liposomes mediated membrane fusion in the pH range 5-7. In addition, the transgene expression results using the T7Luc expression vector convincingly support the endosome-disrupting role of the presently described mono-histidylated cationic transfection lipids and the release of DNA into the cytosol. We conclude that covalent grafting of a single histidine amino acid residue to suitable twin-chain hydrophobic compounds is able to impart remarkable transfection properties on the resulting mono-histidylated cationic amphiphile, presumably via the endosome-disrupting characteristics of the histidine functionalities.

Using a nanopore for single molecule detection and single cell transfection.

PubMed

Nelson, Edward M; Kurz, Volker; Shim, Jiwook; Timp, Winston; Timp, Gregory

2012-07-07

We assert that it is possible to trap and identify proteins, and even (conceivably) manipulate proteins secreted from a single cell (i.e. the secretome) through transfection via electroporation by exploiting the exquisite control over the electrostatic potential available in a nanopore. These capabilities may be leveraged for single cell analysis and transfection with single molecule resolution, ultimately enabling a careful scrutiny of tissue heterogeneity.

In vitro and in vivo transfection of primary phagocytes via microbubble-mediated intraphagosomal sonoporation.

PubMed

Lemmon, Jason C M; McFarland, Ryan J; Rybicka, Joanna M; Balce, Dale R; McKeown, Kyle R; Krohn, Regina M; Matsunaga, Terry O; Yates, Robin M

2011-08-31

The professional phagocytes, such as macrophages and dendritic cells, are the subject of numerous research efforts in immunology and cell biology. The use of primary phagocytes in these investigations however, are limited by their inherent resistance to transfection with DNA constructs. As a result, the use of phagocyte-like immortalized cell lines is widespread. While these cell lines are transfection permissive, they are generally regarded as poor biological substitutes for primary phagocytes. By exploiting the phagocytic machinery of primary phagocytes, we developed a non-viral method of DNA transfection of macrophages that employs intraphagosomal sonoporation mediated by internalized lipid-based microbubbles. This approach enables the transfection of primary phagocytes in vitro, with a modest, but reliable efficiency. Furthermore, this methodology was readily adapted to transfect murine peritoneal macrophages in vivo. This technology has immediate application to current research efforts and has potential for use in gene therapy and vaccination strategies. Copyright © 2011 Elsevier B.V. All rights reserved.

Gold Nanoparticle Mediated Laser Transfection for Efficient siRNA Mediated Gene Knock Down

PubMed Central

Heinemann, Dag; Schomaker, Markus; Kalies, Stefan; Schieck, Maximilian; Carlson, Regina; Escobar, Hugo Murua; Ripken, Tammo; Meyer, Heiko; Heisterkamp, Alexander

2013-01-01

Laser based transfection methods have proven to be an efficient and gentle alternative to established molecule delivery methods like lipofection or electroporation. Among the laser based methods, gold nanoparticle mediated laser transfection bears the major advantage of high throughput and easy usability. This approach uses plasmon resonances on gold nanoparticles unspecifically attached to the cell membrane to evoke transient and spatially defined cell membrane permeabilization. In this study, we explore the parameter regime for gold nanoparticle mediated laser transfection for the delivery of molecules into cell lines and prove its suitability for siRNA mediated gene knock down. The developed setup allows easy usage and safe laser operation in a normal lab environment. We applied a 532 nm Nd:YAG microchip laser emitting 850 ps pulses at a repetition rate of 20.25 kHz. Scanning velocities of the laser spot over the sample of up to 200 mm/s were tested without a decline in perforation efficiency. This velocity leads to a process speed of ∼8 s per well of a 96 well plate. The optimal particle density was determined to be ∼6 particles per cell using environmental scanning electron microscopy. Applying the optimized parameters transfection efficiencies of 88% were achieved in canine pleomorphic adenoma ZMTH3 cells using a fluorescent labeled siRNA while maintaining a high cell viability of >90%. Gene knock down of d2-EGFP was demonstrated and validated by fluorescence repression and western blot analysis. On basis of our findings and established mathematical models we suppose a mixed transfection mechanism consisting of thermal and multiphoton near field effects. Our findings emphasize that gold nanoparticle mediated laser transfection provides an excellent tool for molecular delivery for both, high throughput purposes and the transfection of sensitive cells types. PMID:23536802

A transfected cell model for the renal toxin transporter, rOCT2.

PubMed

Pan, B F; Sweet, D H; Pritchard, J B; Chen, R; Nelson, J A

1999-02-01

A cDNA for the organic cation transporter (rOCT2) of the rat kidney was inserted into the retroviral plasmid pLXSN. This plasmid was used to stably transfect NIH3T3 cells. The transfected cell line exhibited an enhanced rate of tetraethylammonium (TEA) uptake and efflux compared to wild-type NIH3T3 cells. Uptake of TEA by the transfected cells was markedly reduced upon incubation at 4 degrees C. When the extracellular pH was lowered from 8.1 to 5.9, uptake was also reduced, suggesting inhibition of rOCT2 by extracellular protons. The apparent K(m) for TEA in the transfected cells was 141 microM. The classical organic cation transport inhibitors, cyanine 863 and cimetidine, produced noncompetitive inhibition with apparent Ki values of 0.81 and 198 microM, respectively. Daunomycin, vinblastine, and the deoxyadenosine analogs, 2'-deoxytubercidin and 2-chlorodeoxyadenosine, did not appear to be substrates for rOCT2. However, the anticancer drug, cisplatin, competitively inhibited TEA uptake by rOCT2 with an apparent Ki value of 925 microM, suggesting that rOCT2 may play a role in its renal secretion. In summary, transfected NIH3T3 cells provide a facile system by which this and other organic ion transporters can be studied.

Structure relationship of cationic lipids on gene transfection mediated by cationic liposomes.

PubMed

Paecharoenchai, Orapan; Niyomtham, Nattisa; Apirakaramwong, Auayporn; Ngawhirunpat, Tanasait; Rojanarata, Theerasak; Yingyongnarongkul, Boon-ek; Opanasopit, Praneet

2012-12-01

The aim of this study was to investigate the transfection efficiency of cationic liposomes formulated with phosphatidylcholine (PC) and novel synthesized diethanolamine-based cationic lipids at a molar ratio of 5:1 in comparison with Lipofectamine™ 2000. Factors affecting transfection efficiency and cell viability, including the chemical structure of the cationic lipids, such as different amine head group (diamine and polyamine; and non-spermine and spermine) and acyl chain lengths (C14, C16, and C18) and the weight ratio of liposomes to DNA were evaluated on a human cervical carcinoma cell line (HeLa cells) using the pDNA encoding green fluorescent protein (pEGFP-C2). Characterizations of these lipoplexes in terms of size and charge measurement and agarose gel electrophoresis were performed. The results from this study revealed that almost no transfection was observed in the liposome formulations composed of cationic lipids with a non-spermine head group. In addition, the transfection efficiency of these cationic liposomes was in the following order: spermine-C14 > spermine-C16 > spermine-C18. The highest transfection efficiency was observed in the formulation of spermine-C14 liposomes at a weight ratio of 25; furthermore, this formulation was safe for use in vitro. In conclusion, cationic liposomes containing spermine head groups demonstrated promising potential as gene carriers.

Microsphere-liposome complexes protect adenoviral vectors from neutralising antibody without losses in transfection efficiency, in-vitro.

PubMed

Steel, Jason C; Cavanagh, Heather M A; Burton, Mark A; Kalle, Wouter H J

2004-11-01

Adenoviral vectors have been commonly used in gene therapy protocols but the success of their use is often limited by the induction of host immunity to the vector. Following exposure to the adenoviral vector, adenoviral-specific neutralising antibodies are produced, which limits further administration. This study examines the effectiveness of a novel combination of microspheres and liposomes for the shielding of adenovirus from neutralising antibodies in an in-vitro setting. We show that liposomes are effective in the protection of adenovirus from neutralising antibody and that the conjugation of these complexes to microspheres augments the level of protection. This study further reveals that previously neutralised adenovirus may still be transported into the cell via liposome-cell interactions and is still capable of expressing its genes, making this vector an effective tool for circumvention of the humoral immune response. We also looked at possible side effects of using the complexes, namely increases in cytotoxicity and reductions in transfection efficiency. Our results showed that varying the liposome:adenovirus ratio can reduce the cytotoxicity of the vector as well as increase the transfection efficiency. In addition, in cell lines that are adenoviral competent, transfection efficiencies on par with uncomplexed adenoviral vectors were achievable with the combination vector.

[Construction of the superantigen SEA transfected laryngocarcinoma cells].

PubMed

Ji, Xiaobin; Jingli, J V; Liu, Qicai; Xie, Jinghua

2013-04-01

To construct an eukaryotic expression vectors containing superantigen staphylococcal enterotoxin A (SEA) gene, and to identify its expression in laryngeal squamous carcinoma cells. SEA full-length gene fragment was obtained from ATCC13565 genome of the staphylococcus, referencing standard strains producing SEA. Coding sequence of SEA was artificially synthetized. Than, SEA gene fragments was subcloned into eukaryotic expression vector pIRES-EGFP. The recombinant plasmid pSEA-IRES-EGFP was constructed and was transfected to laryngocarcinoma Hep-2 cells. Resistant clones were screened by G418. The expression of SEA in laryngocarcinoma cells was identified with ELISA and RT-PCR method. The subclone of artificially synthetized SEA gene was subclone to eukaryotic expression vector pires-EGFP. Flanking sequence confirmed that SEA sequence was fully identical to the coding sequence of standard staphylococcus strains ATCC13565 in Genbank. After recombinant plasmid transfected to laryngocarcinoma cells, the resistant clones was obtained after screening for two weeks. The clones were selected. The specific gene fragment was obtained by RT-PCR amplification. ELISA assay confirmed that the content of SEA protein in supernatant fluid of cell culture had reached about Pg level. The recombinant eukaryotic expression vector containing superantigen SEA gene is successfully constructed, and is capable of effective expression and continued secretion of SEA protein in laryngochrcinoma Hep-2 cells after recombinant plasmid transfected to laryngocarcinoma cells.

[Experimental study on dog's bone marrow stem cells transfected by pIRES2-EGFP-IGF-1 gene].

PubMed

Zhu, Guo-qiang; Wu, Zhi-fen; Li, Yuan-fei; Hu, De-hua; Wang, Qin-tao

2006-12-01

To establish the bone marrow stem cells (MSC) model which could highly express the insulin-like growth factor 1 (IGF-1) transfected by dog's IGF-1 gene. pIRES2-EGFP-IGF-1 was transfected into MSC by lipofectamine. Positive clones were selected with G418. The expression of IGF-1 protein in the MSC was determined by immunohistochemistry and Western blot analysis. The IGF-1 in the supernatant of the transfected MSC was detected by sandwich-in ELISA. The periodontal ligament cells (PDLC) were cultured in the supernatant of the transfected MSC. The changes of PDLC' proliferation were observed by MTT. IGF-1-transfected MSC could apparently express IGF-1. The IGF-1 protein in the supernatant of the transfected MSC was confirmed by sandwich-in ELISA. IGF-1 could promote the PDLC' proliferation. The MSC transfected by dog's IGF-1 gene can highly express IGF-1, which may lay the foundation for further study on periodontal regeneration.

Formation of functional asialoglycoprotein receptor after transfection with cDNAs encoding the receptor proteins.

PubMed Central

McPhaul, M; Berg, P

1986-01-01

The rat asialoglycoprotein receptor (ASGP-R) has been expressed in cultured rat hepatoma cells (HTC cells) after transfection with cloned cDNAs. Fluorescence-activated cell sorting of transfected cells was used to identify the functional cDNA clones and to isolate cells expressing the ASGP-R. Simultaneous or sequential transfections with two cloned cDNAs that encode related but distinctive polypeptide chains were needed to obtain ASGP-R activity; transfection with either cDNA alone failed to produce detectable ASGP-R. The affinity of transduced ASGP-R for asialo orosomucoid is less than that of the native rat ASGP-R, and the number of surface receptors in clones expressing ASGP-R is about one-fifth that found on rat hepatocytes. Images PMID:3466162

Specificity of gap junction communication among human mammary cells and connexin transfectants in culture

PubMed Central

1993-01-01

In a previous paper (Lee et al., 1992), it was shown that normal human mammary epithelial cells (NMEC) express two connexin genes, Cx26 and Cx43, whereas neither gene is transcribed in a series of mammary tumor cell lines (TMEC). In this paper it is shown that normal human mammary fibroblasts (NMF) communicate and express Cx43 mRNA and protein. Transfection of either Cx26 or Cx43 genes into a tumor line, 21MT-2, induced the expression of the corresponding mRNAs and proteins as well as communication via gap junctions (GJs), although immunofluorescence demonstrated that the majority of Cx26 and Cx43 proteins present in transfected TMEC was largely cytoplasmic. Immunoblotting demonstrated that NMEC, NMF, and transfected TMEC each displayed a unique pattern of posttranslationally modified forms of Cx43 protein. The role of different connexins in regulating gap junction intercellular communication (GJIC) was examined using a novel two-dye method to assess homologous and heterologous communication quantitatively. The recipient cell population was prestained with a permanent non-toxic lipophilic dye that binds to membranes irreversibly (PKH26, Zynaxis); and the donor population is treated with a GJ-permeable dye Calcein, a derivative of fluorescein diacetate (Molecular Probes). After mixing the two cell populations under conditions promoting GJ formation, cells were analyzed by flow cytometry to determine the percentage of cells containing both dyes. It is shown here that Cx26 and Cx43 transfectants display strong homologous communication, as do NMEC and NMF. Furthermore, NMEC mixed with NMF communicate efficiently, Cx26 transfectants communicate with NMEC but not with NMF, and Cx43 transfectants communicate with NMF. Communication between Cx26 TMEC transfectants and NMEC was asymetrical with preferential movement of calcein from TMEC to NMEC. Despite the presence of Cx43 as well as Cx26 encoded proteins in the GJs of NMEC, few Cx43 transfectants communicated with NMEC

Hyperbranched-dendrimer architectural copolymer gene delivery using hyperbranched PEI conjugated to poly(propyleneimine) dendrimers: synthesis, characterization, and evaluation of transfection efficiency

NASA Astrophysics Data System (ADS)

Alavi, Seyyed Jamal; Gholami, Leila; Askarian, Saeedeh; Darroudi, Majid; Massoudi, Abdolhossein; Rezaee, Mehdi; Kazemi Oskuee, Reza

2017-02-01

The applications of dendrimer-based vectors seem to be promising in non-viral gene delivery because of their potential for addressing the problems with viral vectors. In this study, generation 3 poly(propyleneimine) (G3-PPI) dendrimers with 1, 4-diaminobutane as a core initiator was synthesized using a divergent growth approach. To increase the hydrophobicity and reduce toxicity, 10% of primary amines of G3-PPI dendrimers were replaced with bromoalkylcarboxylates with different chain lengths (6-bromohexanoic and 10-bromodecanoic). Then, to retain the overall buffering capacity and enhance transfection, the alkylcarboxylate-PPIs were conjugated to 10 kDa branched polyethylenimine (PEI). The results showed that the modified PPI was able to form complexes with the diameter of less than 60 nm with net-positive surface charge around 20 mV. No significant toxicity was observed in modified PPIs; however, the hexanoate conjugated PPI-PEI (PPI-HEX-10% PEI) and the decanoate conjugated PPI-PEI (PPI-DEC-10%-PEI) showed the best transfection efficiency in murine neuroblastoma (Neuro-2a) cell line, even PPI-HEX-10%-PEI showed transfection efficiency equal to standard PEI 25 kDa with reduced toxicity. This study suggested a new series of hyperbranched (PEI)-dendrimer (PPI) architectural copolymers as non-viral gene delivery vectors with high transfection efficiency and low toxicity.

Prolonged expression of MHC class I - peptide expression in bone marrow derived retrovirus transfected matured dendritic cells by continuous centrifugation in the presence of IL-4.

PubMed

Hettihewa, L M

2011-11-01

Dendritic cells (DCs) are potent antigen presenting cells which proceed from immature to a mature stage during their differentiation. There are several methods of obtaining long lasting mature antigen expressing DCs and different methods show different levels of antigen expressions. We investigated bone marrow derived DCs for the degree of maturation and genetically engineered antigen presentation in the presence of interleukin-4 (IL-4) as a maturity enhancer. DCs and transfected retrovirus were cultured together in the presence of granulocyte-macrophage colony stimulating factor (GMCSF)-IL4, GMCSF +IL4, lipopolysaccharide (LPS). B 7.1, B7.2 and CD11c were measured by the degree of immune fluorescence using enhanced green fluorescent protein (EGFP) shuttled retrovirus transfected antigen. Degree of MHC class I molecule with antigen presentation of antigen was also evaluated by fluorescence activated cell sorting. The antigen presenting capacity of transfected DCs was investigated. Bone marrow DCs were generated in the presence of GMCSF and IL-4 in vitro. Dividing bone marrow cells were infected with EGFP shuttled retrovirus expressing SSP2 by prolonged centrifugation for three consecutive days from day 5, 6 and 7 and continued to culture in the presence of GMSCF and IL-4 until day 8. IL-4 as a cytokine increased the maturation of retrovirus transfected DCs by high expression of B 7-1 and B 7-2. Also, IL-4 induced DC enhanced by the prolonged centrifugation and it was shown by increased antigen presentation of these dendric cells as antigen presenting cell (APC). Cytolytic effects were significantly higher in cytotoxic T cell response (CTLs) mixed with transfected DCs than CTLs mixed with pulsed DCs. There was an enhanced antigen presentation by prolonged expression of antigen loaded MHC class I receptors in DCs in the presence of IL-4 by prolonged centrifugation.

GAP JUNCTION COMMUNICATON IN A TRANSFECTED HUMAN CELL LINE: ACTION OF MELATONIN AND MAGNETIC FIELDS

EPA Science Inventory

GAP JUNCTION COMMUNICTION IN TRANSFECTED HUMAN CELL LINE: ACTION OF MELATONIN AND MAGNETIC FIELDS.

OBJECTIVE: We previously showed that functional gap junction communication (GJC), as monitored by dye transfer (DT), could be enhanced in mouse C3H 10T112 cells and in mouse...

Transfection of brain capillary endothelial cells in primary culture with defined blood-brain barrier properties.

PubMed

Burkhart, Annette; Thomsen, Louiza Bohn; Thomsen, Maj Schneider; Lichota, Jacek; Fazakas, Csilla; Krizbai, István; Moos, Torben

2015-08-07

Primary brain capillary endothelial cells (BCECs) are a promising tool to study the blood-brain barrier (BBB) in vitro, as they maintain many important characteristics of the BBB in vivo, especially when co-cultured with pericytes and/or astrocytes. A novel strategy for drug delivery to the brain is to transform BCECs into protein factories by genetic modifications leading to secretion of otherwise BBB impermeable proteins into the central nervous system. However, a huge challenge underlying this strategy is to enable transfection of non-mitotic BCECs, taking a non-viral approach. We therefore aimed to study transfection in primary, non-mitotic BCECs cultured with defined BBB properties without disrupting the cells' integrity. Primary cultures of BCECs, pericytes and astrocytes were generated from rat brains and used in three different in vitro BBB experimental arrangements, which were characterised based on a their expression of tight junction proteins and other BBB specific proteins, high trans-endothelial electrical resistance (TEER), and low passive permeability to radiolabeled mannitol. Recombinant gene expression and protein synthesis were examined in primary BCECs. The BCECs were transfected using a commercially available transfection agent Turbofect™ to express the red fluorescent protein HcRed1-C1. The BCECs were transfected at different time points to monitor transfection in relation to mitotic or non-mitotic cells, as indicated by fluorescence-activated cell sorting analysis after 5-and 6-carboxylfluorescein diacetate succinidyl ester incorporation. The cell cultures exhibited important BBB characteristics judged from their expression of BBB specific proteins, high TEER values, and low passive permeability. Among the three in vitro BBB models, co-culturing with BCECs and astrocytes was well suited for the transfection studies. Transfection was independent of cell division and with equal efficacy between the mitotic and non-mitotic BCECs. Importantly

Mechanisms of Nanoparticle Mediated siRNA Transfection by Melittin-Derived Peptides

PubMed Central

Hou, Kirk K.; Pan, Hua; Ratner, Lee; Schlesinger, Paul H.; Wickline, Samuel A.

2014-01-01

Traditional peptide-mediated siRNA transfection via peptide transduction domains exhibits limited cytoplasmic delivery of siRNA due to endosomal entrapment. This work overcomes these limitations with the use of membrane-destabilizing peptides derived from melittin for the knockdown of NFkB signaling in a model of adult T-Cell leukemia/lymphoma. While the mechanism of siRNA delivery into the cytoplasmic compartment by peptide transduction domains has not been well studied, our analysis of melittin derivatives indicates that concurrent nanocomplex disassembly and peptide-mediated endosomolysis are crucial to siRNA transfection. Importantly, in the case of the most active derivative, p5RHH, this process is initiated by acidic pH, indicating that endosomal acidification after macropinocytosis can trigger siRNA release into the cytoplasm. These data provide general principles regarding nanocomplex response to endocytosis which may guide the development of peptide/siRNA nanocomplex-based transfection. PMID:24053333

Biodegradable gadolinium-chelated cationic poly(urethane amide) copolymers for gene transfection and magnetic resonance imaging.

PubMed

Gao, Xiaolong; Wang, Gangmin; Shi, Ting; Shao, Zhihong; Zhao, Peng; Shi, Donglu; Ren, Jie; Lin, Chao; Wang, Peijun

2016-08-01

Theranostic nano-polyplexes containing gene and imaging agents hold a great promise for tumor diagnosis and therapy. In this work, we develop a group of new gadolinium (Gd)-chelated cationic poly(urethane amide)s for gene delivery and T1-weighted magnetic resonance (MR) imaging. Cationic poly(urethane amide)s (denoted as CPUAs) having multiple disulfide bonds, urethane and amide linkages were synthesized by stepwise polycondensation reaction between 1,4-bis(3-aminopropyl)piperazine and a mixture of di(4-nitrophenyl)-2, 2'-dithiodiethanocarbonate (DTDE-PNC) and diethylenetriaminepentaacetic acid (DTPA) dianhydride at varied molar ratios. Then, Gd-chelated CPUAs (denoted as GdCPUAs) were produced by chelating Gd(III) ions with DTPA residues of CPUAs. These GdCPUAs could condense gene into nanosized and positively-charged polyplexes in a physiological condition and, however, liberated gene in an intracellular reductive environment. In vitro transfection experiments revealed that the GdCPUA at a DTDE-PNC/DTPA residue molar ratio of 85/15 induced the highest transfection efficiency in different cancer cells. This efficiency was higher than that yielded with 25kDa branched polyethylenimine as a positive control. GdCPUAs and their polyplexes exhibited low cytotoxicity when an optimal transfection activity was detected. Moreover, GdCPUAs may serve as contrast agents for T1-weighted magnetic resonance imaging. The results of this work indicate that biodegradable Gd-chelated cationic poly(urethane amide) copolymers have high potential for tumor theranostics. Copyright © 2016 Elsevier B.V. All rights reserved.

The role of helper lipids in the intracellular disposition and transfection efficiency of niosome formulations for gene delivery to retinal pigment epithelial cells.

PubMed

Ojeda, Edilberto; Puras, Gustavo; Agirre, Mireia; Zarate, Jon; Grijalvo, Santiago; Eritja, Ramon; DiGiacomo, Luca; Caracciolo, Giulio; Pedraz, Jose-Luis

2016-04-30

In this work, we carried out a comparative study of four different niosome formulations based on the same cationic lipid and non-ionic tensoactive. The niosomes prepared by oil-in-water emulsion technique (o/w) only differed in the helper lipid composition: squalene, cholesterol, squalane or no helper lipid. Niosomes and nioplexes elaborated upon the addition of pCMS-EGFP reporter plasmid were characterized in terms of size, zeta potential and polydispersity index. The capacity of the niosomes to condense, release and protect the DNA against enzymatic degradation was evaluated by agarose gel electrophoresis. In vitro experiments were carried out to evaluate transfection efficiency and cell viability in retinal pigment epithelial cells. Moreover, uptake and intracellular trafficking studies were performed to further understand the role of the helper lipids in the transfection process. Interestingly, among all tested formulations, niosomes elaborated with squalene as helper lipid were the most efficient transfecting cells. Such transfection efficiency could be attributed to their higher cellular uptake and the particular entry pathways used, where macropinocytosis pathway and lysosomal release played an important role. Therefore, these results suggest that helper lipid composition is a crucial step to be considered in the design of niosome formulation for retinal gene delivery applications since clearly modulates the cellular uptake, internalization mechanism and consequently, the final transfection efficiency. Copyright © 2016 Elsevier B.V. All rights reserved.

Inflammatory mediator mRNA expression by adenovirus E1A-transfected bronchial epithelial cells.

PubMed

Higashimoto, Yuji; Elliott, W Mark; Behzad, Ali R; Sedgwick, Edward G; Takei, Tatsuo; Hogg, James C; Hayashi, Shizu

2002-07-15

Lung tissue from patients with emphysema and airway obstruction carries excess adenoviral E1A DNA that is expressed as protein in airway surface epithelium and is associated with an increased inflammatory response. To examine mechanisms by which latent adenoviral infection might amplify the inflammatory process, we transfected primary human bronchial epithelial (HBE) cells from three separate patients undergoing lung resection so that they stably expressed adenovirus E1A. Lipopolysaccharide stimulation of the E1A-transfected HBE cells increased intercellular adhesion molecule-1 and interleukin-8 mRNA and protein expression compared with control cells from the same patient. It also induced greater intercellular adhesion molecule-1 promoter activity and greater nuclear factor-kappa B binding activity of nuclear extracts in E1A transfectants than controls. E1A-positive transfectants constitutively expressed transforming growth factor-beta 1 mRNA and protein, whereas this expression was either very low or not detected in control cells. We conclude that adenoviral E1A transfection transforms primary HBE cells and upregulates their production of mediators that are clinically relevant to the pathogenesis of chronic obstructive pulmonary disease.

Tissue Engineering Using Transfected Growth-Factor Genes

NASA Technical Reports Server (NTRS)

Madry, Henning; Langer, Robert S.; Freed, Lisa E.; Trippel, Stephen; Vunjak-Novakovic, Gordana

2005-01-01

A method of growing bioengineered tissues includes, as a major component, the use of mammalian cells that have been transfected with genes for secretion of regulator and growth-factor substances. In a typical application, one either seeds the cells onto an artificial matrix made of a synthetic or natural biocompatible material, or else one cultures the cells until they secrete a desired amount of an extracellular matrix. If such a bioengineered tissue construct is to be used for surgical replacement of injured tissue, then the cells should preferably be the patient s own cells or, if not, at least cells matched to the patient s cells according to a human-leucocyteantigen (HLA) test. The bioengineered tissue construct is typically implanted in the patient's injured natural tissue, wherein the growth-factor genes enhance metabolic functions that promote the in vitro development of functional tissue constructs and their integration with native tissues. If the matrix is biodegradable, then one of the results of metabolism could be absorption of the matrix and replacement of the matrix with tissue formed at least partly by the transfected cells. The method was developed for articular chondrocytes but can (at least in principle) be extended to a variety of cell types and biocompatible matrix materials, including ones that have been exploited in prior tissue-engineering methods. Examples of cell types include chondrocytes, hepatocytes, islet cells, nerve cells, muscle cells, other organ cells, bone- and cartilage-forming cells, epithelial and endothelial cells, connective- tissue stem cells, mesodermal stem cells, and cells of the liver and the pancreas. Cells can be obtained from cell-line cultures, biopsies, and tissue banks. Genes, molecules, or nucleic acids that secrete factors that influence the growth of cells, the production of extracellular matrix material, and other cell functions can be inserted in cells by any of a variety of standard transfection techniques.

Comparative transfection of DNA into primary and transformed mammalian cells from different lineages

PubMed Central

2010-01-01

Background The delivery of DNA into human cells has been the basis of advances in the understanding of gene function and the development of genetic therapies. Numerous chemical and physical approaches have been used to deliver the DNA, but their efficacy has been variable and is highly dependent on the cell type to be transfected. Results Studies were undertaken to evaluate and compare the transfection efficacy of several chemical reagents to that of the electroporation/nucleofection system using both adherent cells (primary and transformed airway epithelial cells and primary fibroblasts as well as embryonic stem cells) and cells in suspension (primary hematopoietic stem/progenitor cells and lymphoblasts). With the exception of HEK 293 cell transfection, nucleofection proved to be less toxic and more efficient at effectively delivering DNA into the cells as determined by cell proliferation and GFP expression, respectively. Lipofectamine and nucleofection of HEK 293 were essentially equivalent in terms of toxicity and efficiency. Transient transfection efficiency in all the cell systems ranged from 40%-90%, with minimal toxicity and no apparent species specificity. Differences in efficiency and toxicity were cell type/system specific. Conclusions In general, the Amaxa electroporation/nucleofection system appears superior to other chemical systems. However, there are cell-type and species specific differences that need to be evaluated empirically to optimize the conditions for transfection efficiency and cell survival. PMID:20144189

A new protocol for functional analysis of adipogenesis using reverse transfection technology and time-lapse video microscopy.

PubMed

Grönniger, Elke; Wessel, Sonja; Kühn, Sonja Christin; Söhle, Jörn; Wenck, Horst; Stäb, Franz; Winnefeld, Marc

2010-07-01

Since the worldwide increase in obesity represents a growing challenge for healthcare systems, research focusing on fat cell metabolism has become a focal point of interest. Here, we describe a small interfering RNA (siRNA)-technology-based screening method to study fat cell differentiation in human primary preadipocytes that could be further developed towards an automated middle-throughput screening procedure. First, we established optimal conditions for the reverse transfection of human primary preadipocytes demonstrating that an efficient reverse transfection of preadipocytes is technically feasible. Aligning the processes of reverse transfection and fat cell differentiation utilizing peroxisome proliferator-activated receptor gamma (PPAR gamma)-siRNA, we showed that preadipocyte differentiation was suppressed by knock-down of PPAR gamma, the key regulator of fat cell differentiation. The use of fluorescently labelled fatty acids in combination with fluorescence time-lapse microscopy over a longer period of time enabled us to quantify the PPAR gamma phenotype. Additionally, our data demonstrate that reverse transfection of human cultured preadipocytes with TIP60 (HIV-1 Tat-interacting protein 60)-siRNA lead to a TIP60 knock-down and subsequently inhibits fat cell differentiation, suggesting a role of this protein in human adipogenesis. In conclusion, we established a protocol that allows for an efficient functional and time-dependent analysis by quantitative time-lapse microscopy to identify novel adipogenesis-associated genes.

Re-induction of cell differentiation and (131)I uptake in dedifferentiated FTC-133 cell line by TSHR gene transfection.

PubMed

Feng, Fang; Wang, Hui; Hou, Shasha; Fu, Hongliang

2012-11-01

Radioiodine therapy is commonly used to treat differentiated thyroid cancer (DTC), but a major challenge is dedifferentiation of DTC with the loss of radioiodine uptake. TSHR is a key molecule regulating thyrocyte proliferation and function. This study aimed to test the therapeutic potential of TSHR in dedifferentiated DTC by gene transfection in order to restore cell differentiation and radioiodine uptake. Dedifferentiated FTC-133 (dFTC-133) cells were obtained by monoclonal culture of FTC-133 cell line after (131)I radiation. Recombinant plasmid pcDNA3.1-hTSHR was transfected into dFTC-133 cells by using Lipofectamine 2000 reagent. Immunofluorescence analysis was carried out to confirm TSHR expression and its location. Radioiodine uptake assay was thereafter investigated. mRNAs and proteins of TSHR and other thyroid differentiated markers were detected by real-time PCR and western blot respectively. Among the thyroid specific genes in dFTC-133 cells with stable low radioiodine uptake, TSHR was down-regulated most significantly compared with FTC-133. Then, after TSHR gene transfection, augmented expression of TSHR was observed in dFTC-133 cell surface and cytoplasm by immunofluorescence analysis. It was found that (125)I uptake was 2.9 times higher (t=28.63, P<.01) in cells with TSHR transfection than control. The mRNAs of TSHR, NIS, TPO and Tg were also significantly increased by 1.7 times (t=13.8, P<.05), 4 times (t=28.52, P<.05), 1.5 times (t=14.43, P<.05) and 2.2 times (t=19.83, P<.05) respectively compared with control group. Decreased TSHR expression correlated with FTC-133 ongoing dedifferentiation. TSHR transfection contributed to the re-differentiation of dedifferentiated thyroid follicular carcinoma cells. Copyright © 2012 Elsevier Inc. All rights reserved.

Show Me: A Report Card on Public Higher Education in Missouri

ERIC Educational Resources Information Center

Czelusniak, Sandra; Palmiero, Phyllis

2008-01-01

Missouri is the "Show Me" State. And with this goal in mind, the American Council of Trustees and Alumni (ACTA) offers this report card to examine the state of higher education in Missouri. If the nation is to ensure its continued preeminence in higher education, policymakers, trustees, alumni, and taxpayers must know what is going on in…

Minichromosome assembly of non-integrated plasmid DNA transfected into mammalian cells.

PubMed Central

Reeves, R; Gorman, C M; Howard, B

1985-01-01

The nucleoprotein structures formed on various plasmid expression vectors transfected into mammalian cells by both the calcium phosphate and DEAE-dextran methods have been studied. We demonstrate by a variety of means that mammalian cells are capable of rapidly assembling non-integrated circular plasmids (both replicating and non-replicating) into typical "minichromosomes" containing nucleosomes with a 190 bp repetitive spacing. Treatment of recipient cells with sodium butyrate for a short period of time (12-16 h) immediately following transfection markedly increased the DNase I digestion sensitivity of the newly assembled plasmid chromatin. Furthermore, minichromosomes isolated from such butyrate-treated cells are depleted in histone H1 and contain highly acetylated forms of histone H4. These findings are entirely consistent with our earlier speculation (Gorman et al., Nucleic Acids Res. 11, 1044; 1983) that appropriate butyrate treatment might stimulate transient expression of newly transfected genes by facilitating their assembly into an "active" type of chromatin structure. Images PMID:3859838

Localized transfection on arrays of magnetic beads coated with PCR products.

PubMed

Isalan, Mark; Santori, Maria Isabel; Gonzalez, Cayetano; Serrano, Luis

2005-02-01

High-throughput gene analysis would benefit from new approaches for delivering DNA or RNA into cells. Here we describe a simple system that allows any molecular biology laboratory to carry out multiple, parallel cell transfections on microscope coverslip arrays. By using magnetically defined positions and PCR product-coated paramagnetic beads, we achieved transfection in a variety of cell lines. Beads may be added to the cells at any time, allowing both spatial and temporal control of transfection. Because the beads may be coated with more than one gene construct, the method can be used to achieve cotransfection within single cells. Furthermore, PCR-generated mutants may be conveniently screened, bypassing cloning and plasmid purification steps. We illustrated the applicability of the method by screening combinatorial peptide libraries, fused to GFP, to identify previously unknown cellular localization motifs. In this way, we identified several localizing peptides, including structured localization signals based around the scaffold of a single C2H2 zinc finger.

Biophysical and transfection studies of the diC(14)-amidine/DNA complex.

PubMed Central

Cherezov, Vadim; Qiu, Hong; Pector, Veronique; Vandenbranden, Michel; Ruysschaert, Jean-Marie; Caffrey, Martin

2002-01-01

Liposomes of the synthetic cationic lipid, N-t-butyl-N'-tetradecylamino-propionamidine (diC(14)-amidine), efficiently ports DNA into mammalian cells in the absence of other (neutral) lipids. The compositional simplicity of this transfection mix makes it attractive from a formulation perspective. We have used low- and wide-angle x-ray diffraction and polarized light microscopy to characterize the thermotropic phase behavior and microstructure of diC(14)-amidine and of the lipid/DNA (circular plasmid, 5.4 kb) complex with a view to understanding the structure of the complex and its role in transfection. Upon heating, the lipid in buffer undergoes a lamellar crystalline (L(c), d(001) = 41.7 A)-to-lamellar liquid crystal (L(c)(alpha), d(001) depends on hydration and T) transition at approximately 40 degrees C. Sonicated lipid vesicles with a reported transition temperature of approximately 23 degrees C complex with DNA. Complex formation is complete at a DNA/lipid mole ratio (rho) of 0.8. Adding DNA to the lipid causes d(001) of the multilayered complex to drop from 52 to 49 A as rho rises from 0.03 to 1.64. The minimal DNA-DNA duplex separation observed is 26 A, consistent with the close packing of B-DNA. Lipid bilayers in the complex undergo a lamellar gel (L(c)(beta))-to-L(c)(alpha) (superscript c refers to complex) transition at approximately 23 degrees C. Transfection efficiency was maximized at rho = 0.4. The structure and transfection data combined suggest that densely packaged DNA in a net positively charged complex is essential for transfection. PMID:12023234

Application of nanostructured biochips for efficient cell transfection microarrays

NASA Astrophysics Data System (ADS)

Akkamsetty, Yamini; Hook, Andrew L.; Thissen, Helmut; Hayes, Jason P.; Voelcker, Nicolas H.

2007-01-01

Microarrays, high-throughput devices for genomic analysis, can be further improved by developing materials that are able to manipulate the interfacial behaviour of biomolecules. This is achieved both spatially and temporally by smart materials possessing both switchable and patterned surface properties. A system had been developed to spatially manipulate both DNA and cell growth based upon the surface modification of highly doped silicon by plasma polymerisation and polyethylene grafting followed by masked laser ablation for formation of a pattered surface with both bioactive and non-fouling regions. This platform has been successfully applied to transfected cell microarray applications with the parallel expression of genes by utilising its ability to direct and limit both DNA and cell attachment to specific sites. One of the greatest advantages of this system is its application to reverse transfection, whereupon by utilising the switchable adsorption and desorption of DNA using a voltage bias, the efficiency of cell transfection can be enhanced. However, it was shown that application of a voltage also reduces the viability of neuroblastoma cells grown on a plasma polymer surface, but not human embryonic kidney cells. This suggests that the application of a voltage may not only result in the desorption of bound DNA but may also affect attached cells. The characterisation of a DNA microarray by contact printing has also been investigated.

Toward establishing model organisms for marine protists: Successful transfection protocols for Parabodo caudatus (Kinetoplastida: Excavata).

PubMed

Gomaa, Fatma; Garcia, Paulo A; Delaney, Jennifer; Girguis, Peter R; Buie, Cullen R; Edgcomb, Virginia P

2017-09-01

We developed protocols for, and demonstrated successful transfection of, the free-living kinetoplastid flagellate Parabodo caudatus with three plasmids carrying a fluorescence reporter gene (pEF-GFP with the EF1 alpha promoter, pUB-GFP with Ubiquitin C promoter, and pEYFP-Mitotrap with CMV promoter). We evaluated three electroporation approaches: (1) a square-wave electroporator designed for eukaryotes, (2) a novel microfluidic transfection system employing hydrodynamically-controlled electric field waveforms, and (3) a traditional exponential decay electroporator. We found the microfluidic device provides a simple and efficient platform to quickly test a wide range of electric field parameters to find the optimal set of conditions for electroporation of target species. It also allows for processing large sample volumes (>10 ml) within minutes, increasing throughput 100 times over cuvettes. Fluorescence signal from the reporter gene was detected a few hours after transfection and persisted for 3 days in cells transfected by pEF-GFP and pUB-GFP plasmids and for at least 5 days post-transfection for cells transfected with pEYFP-Mitotrap. Expression of the reporter genes (GFP and YFP) was also confirmed using reverse transcription-PCR (RT-PCR). This work opens the door for further efforts with this taxon and close relatives toward establishing model systems for genome editing. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Plasma-mediated transfection of RPE

NASA Astrophysics Data System (ADS)

Palanker, D.; Chalberg, T.; Vankov, A.; Huie, P.; Molnar, F. E.; Butterwick, A.; Calos, M.; Marmor, M.; Blumenkranz, M. S.

2006-02-01

A major obstacle in applying gene therapy to clinical practice is the lack of efficient and safe gene delivery techniques. Viral delivery has encountered a number of serious problems including immunological reactions and malignancy. Non-viral delivery methods (liposomes, sonoporation and electroporation) have either low efficiency in-vivo or produce severe collateral damage to ocular tissues. We discovered that tensile stress greatly increases the susceptibility of cellular membranes to electroporation. For synchronous application of electric field and mechanical stress, both are generated by the electric discharge itself. A pressure wave is produced by rapid vaporization of the medium. To prevent termination of electric current by the vapor cavity it is ionized thus restoring its electric conductivity. For in-vivo experiments with rabbits a plasmid DNA was injected into the subretinal space, and RPE was treated trans-sclerally with an array of microelectodes placed outside the eye. Application of 250-300V and 100-200 μs biphasic pulses via a microelectrode array resulted in efficient transfection of RPE without visible damage to the retina. Gene expression was quantified and monitored using bioluminescence (luciferase) and fluorescence (GFP) imaging. Transfection efficiency of RPE with this new technique exceeded that of standard electroporation by a factor 10,000. Safe and effective non-viral DNA delivery to the mammalian retina may help to materialize the enormous potential of the ocular gene therapy. Future experiments will focus on continued characterization of the safety and efficacy of this method and evaluation of long-term transgene expression in the presence of phiC31 integrase.

Transfected connexin45 alters gap junction permeability in cells expressing endogenous connexin43

PubMed Central

1995-01-01

Many cells express multiple connexins, the gap junction proteins that interconnect the cytosol of adjacent cells. Connexin43 (Cx43) channels allow intercellular transfer of Lucifer Yellow (LY, MW = 443 D), while connexin45 (Cx45) channels do not. We transfected full-length or truncated chicken Cx45 into a rat osteosarcoma cell line ROS-17/2.8, which expresses endogenous Cx43. Both forms of Cx45 were expressed at high levels and colocalized with Cx43 at plasma membrane junctions. Cells transfected with full-length Cx45 (ROS/Cx45) and cells transfected with Cx45 missing the 37 carboxyl-terminal amino acids (ROS/Cx45tr) showed 30-60% of the gap junctional conductance exhibited by ROS cells. Intercellular transfer of three negatively charged fluorescent reporter molecules was examined. In ROS cells, microinjected LY was transferred to an average of 11.2 cells/injected cell, while dye transfer between ROS/Cx45 cells was reduced to 3.9 transfer between ROS/Cx45 cells was reduced to 3.9 cells. In contrast, ROS/Cx45tr cells transferred LY to > 20 cells. Transfer of calcein (MW = 623 D) was also reduced by approximately 50% in ROS/Cx45 cells, but passage of hydroxycoumarin carboxylic acid (HCCA; MW = 206 D) was only reduced by 35% as compared to ROS cells. Thus, introduction of Cx45 altered intercellular coupling between cells expressing Cx43, most likely the result of direct interaction between Cx43 and Cx45. Transfection of Cx45tr and Cx45 had different effects in ROS cells, consistent with a role of the carboxyl-terminal domain of Cx45 in determining gap junction permeability or interactions between connexins. These data suggest that coexpression of multiple connexins may enable cells to achieve forms of intercellular communication that cannot be attained by expression of a single connexin. PMID:7642714

Hyaluronidase and Collagenase Increase the Transfection Efficiency of Gene Electrotransfer in Various Murine Tumors

PubMed Central

Golzio, Muriel; Sersa, Gregor; Escoffre, Jean-Michel; Coer, Andrej; Vidic, Suzana; Teissie, Justin

2012-01-01

Abstract One of the applications of electroporation/electropulsation in biomedicine is gene electrotransfer, the wider use of which is hindered by low transfection efficiency in vivo compared with viral vectors. The aim of our study was to determine whether modulation of the extracellular matrix in solid tumors, using collagenase and hyaluronidase, could increase the transfection efficiency of gene electrotransfer in histologically different solid subcutaneous tumors in mice. Tumors were treated with enzymes before electrotransfer of plasmid DNA encoding either green fluorescent protein or luciferase. Transfection efficiency was determined 3, 9, and 15 days posttransfection. We demonstrated that pretreatment of tumors with a combination of enzymes significantly increased the transfection efficiency of electrotransfer in tumors with a high extracellular matrix area (LPB fibrosarcoma). In tumors with a smaller extracellular matrix area and less organized collagen lattice, the increase was not so pronounced (SA-1 fibrosarcoma and EAT carcinoma), whereas in B16 melanoma, in which only traces of collagen are present, pretreatment of tumors with hyaluronidase alone was more efficient than pretreatment with both enzymes. In conclusion, our results suggest that modification of the extracellular matrix could improve distribution of plasmid DNA in solid subcutaneous tumors, demonstrated by an increase in transfection efficiency, and thus have important clinical implications for electrogene therapy. PMID:21797718

PELA microspheres with encapsulated arginine-chitosan/pBMP-2 nanoparticles induce pBMP-2 controlled-release, transfected osteoblastic progenitor cells, and promoted osteogenic differentiation.

PubMed

Xu, Xiaolong; Qiu, Sujun; Zhang, Yuxian; Yin, Jie; Min, Shaoxiong

2017-03-01

Repair of the bone injury remains a challenge in clinical practices. Recent progress in tissue engineering and therapeutic gene delivery systems have led to promising new strategies for successful acceleration of bone repair process. The aim of this study was to create a controlled-release system to slowly release the arginine-chitosan/plasmid DNA nanoparticles encoding BMP-2 gene (Arg-CS/pBMP-2 NPs), efficiently transfect osteoblastic progenitor cells, secrete functional BMP-2 protein, and promote osteogenic differentiation. In this study, chitosan was conjugated with arginine to generate arginine-chitosan polymer (Arg-CS) for gene delivery. Mix the Arg-CS with pBMP-2 to condense pBMP-2 into nano-sized particles. In vitro transfection assays demonstrated that the transfection efficiency of Arg-CS/pBMP-2 nanoparticles and the expression level of BMP-2 was obviously exceed control groups. Further, PELA microspheres as the controlled-release carrier for the nanoparticles were used to encapsulate Arg-CS/pBMP-2 NPs. We demonstrated that the Arg-CS/pBMP-2 NPs could slowly release from the PELA microspheres at least for 42 d. During the co-culture with the PELA microspheres, the content of BMP-2 protein secreted by MC3T3-E1 reached the peak at 7 d. After 21d, the secretion of BMP-2 protein still maintain a higher level. The alkaline phosphatase activity, alizarin red staining, and osteogenesis-related gene expression by real-time quantitative PCR analysis all showed the PELA microspheres entrapping with Arg-CS/pBMP-2 NPs can obviously induce the osteogenic differentiation. The results indicated that the Arg-CS is a suitable gene vector which can promote the gene transfection. And the novel PELA microspheres-nanoparticle controlled-release system has potential clinical application in the future after further research.

Transfected Babesia bovis Expressing a Tick GST as a Live Vector Vaccine

PubMed Central

Oldiges, Daiane P.; Laughery, Jacob M.; Tagliari, Nelson Junior; Leite Filho, Ronaldo Viana; Davis, William C.; da Silva Vaz, Itabajara; Termignoni, Carlos; Knowles, Donald P.; Suarez, Carlos E.

2016-01-01

. Collectively, these data show the efficacy of a transfected HlGST-Cln B. bovis parasite to induce detectable anti-glutathione-S-transferase antibodies and a reduction in tick size and fecundity of R. microplus feeding in experimentally inoculated animals. PMID:27911903

DyNAvectors: dynamic constitutional vectors for adaptive DNA transfection.

PubMed

Clima, Lilia; Peptanariu, Dragos; Pinteala, Mariana; Salic, Adrian; Barboiu, Mihail

2015-12-25

Dynamic constitutional frameworks, based on squalene, PEG and PEI components, reversibly connected to core centers, allow the efficient identification of adaptive vectors for good DNA transfection efficiency and are well tolerated by mammalian cells.

Effects of AC/DC magnetic fields, frequency, and nanoparticle aspect ratio on cellular transfection of gene vectors

NASA Astrophysics Data System (ADS)

Ford, Kris; Mair, Lamar; Fisher, Mike; Rowshon Alam, Md.; Juliano, Rudolph; Superfine, Richard

2008-10-01

In order to make non-viral gene delivery a useful tool in the study and treatment of genetic disorders, it is imperative that these methodologies be further refined to yield optimal results. Transfection of magnetic nanoparticles and nanorods are used as non-viral gene vectors to transfect HeLa EGFP-654 cells that stably express a mutated enhanced green fluorescent protein (EGFP) gene. We deliver antisense oligonucleotides to these cells designed to correct the aberrant splicing caused by the mutation in the EGFP gene. We also transfect human bronchial endothelial cells and immortalized WI-38 lung cells with pEGFP-N1 vectors. To achieve this we bind the genes to magnetic nanoparticles and nanorods and introduce magnetic fields to effect transfection. We wish to examine the effects of magnetic fields on the transfection of these particles and the benefits of using alternating (AC) magnetic fields in improving transfection rates over direct (DC) magnetic fields. We specifically look at the frequency dependence of the AC field and particle aspect ratio as it pertains to influencing transfection rate. We posit that the increase in angular momentum brought about by the AC field and the high aspect ratio of the nanorod particles, is vital to generating the force needed to move the particle through the cell membrane.

Synthesis and in vitro transfection efficiency of spermine-based cationic lipids with different central core structures and lipophilic tails.

PubMed

Niyomtham, Nattisa; Apiratikul, Nuttapon; Suksen, Kanoknetr; Opanasopit, Praneet; Yingyongnarongkul, Boon-Ek

2015-02-01

Twelve spermine-based cationic lipids with four different central core structures (di(oxyethyl)amino, di(oxyethyl)amino carboxy, 3-amino-1,2-dioxypropyl and 2-amino-1,3-dioxypropyl) and three hydrophobic tails (lauric acid, myristic acid and palmitic acid) were synthesized. The liposomes containing lipids and DOPE showed moderate to good in vitro DNA delivery into HeLa cells. GFP expression experiments revealed that liposomes composed of lipids with 3-amino-1,2-dioxypropyl as a central core structure exhibited highest transfection efficiency under serum-free condition. Whereas, lipid with 2-amino-1,3-dioxypropyl core structure showed highest transfection under 10% serum condition. Moreover, the liposomes and lipoplexes composted of these cationic lipids exhibited low cytotoxicity. Copyright © 2015. Published by Elsevier Ltd.

Transplantation of neurotrophin-3-transfected bone marrow mesenchymal stem cells for the repair of spinal cord injury.

PubMed

Dong, Yuzhen; Yang, Libin; Yang, Lin; Zhao, Hongxing; Zhang, Chao; Wu, Dapeng

2014-08-15

Bone marrow mesenchymal stem cell transplantation has been shown to be therapeutic in the repair of spinal cord injury. However, the low survival rate of transplanted bone marrow mesenchymal stem cells in vivo remains a problem. Neurotrophin-3 promotes motor neuron survival and it is hypothesized that its transfection can enhance the therapeutic effect. We show that in vitro transfection of neurotrophin-3 gene increases the number of bone marrow mesenchymal stem cells in the region of spinal cord injury. These results indicate that neurotrophin-3 can promote the survival of bone marrow mesenchymal stem cells transplanted into the region of spinal cord injury and potentially enhance the therapeutic effect in the repair of spinal cord injury.

Effect of NET-1 siRNA conjugated sub-micron bubble complex combined with low-frequency ultrasound exposure in gene transfection

PubMed Central

Wu, Bolin; Liang, Xitian; Jing, Hui; Han, Xue; Sun, Yixin; Guo, Cunli; Liu, Ying; Cheng, Wen

2018-01-01

The present study evaluated the effect of NET-1 siRNA-conjugated sub-micron bubble (SMB) complexes combined with low-frequency ultrasound exposure in gene transfection. The NET-1 gene was highly expressed level in SMMC-7721 human hepatocellular carcinoma cell line. The cells were divided into seven groups and treated with different conditions. The groups with or without low-frequency ultrasound exposure, groups of adherent cells, and suspension cells were separated. The NET-1 siRNA-conjugated SMB complexes were made in the laboratory and tested by Zetasizer Nano ZS90 analyzer. Flow cytometry was used to estimate the transfection efficiency and cellular apoptosis. Western blot and quantitative real-time polymerase chain reaction (qPCR) were used for the estimation of the protein and mRNA expressions, respectively. Transwell analysis determined the migration and invasion capacities of the tumor cells. The results did not show any difference in the transfection efficiency between adherent and suspension cells. However, the NET-1 siRNA-SMB complexes combined with low-frequency ultrasound exposure could enhance the gene transfection effectively. In summary, the NET-1 siRNA-SMB complexes appeared to be promising gene vehicle. PMID:29423111

[VEGF165 transfected endothelial progenitor cells mediated by lentivirus alleviated ALI in rats].

PubMed

He, Zhaohui; He, Huiwei; Lu, Yuanhua; Chen, Zhi; Xu, Fanghua; Wang, Rongsheng; Yang, Chunli

2017-11-01

To investigate the protective effects of vascular endothelial growth factor-165 (VEGF165) transfected the endothelial progenitor cells (EPCs) mediated by lentivirus on acute lung injury (ALI) in rats. The mononuclear cells from the male Sprague-Dawley (SD) rats were isolated and cultured to get the EPCs for study. The lentivirus vector carrying the human VEGF165 gene was constructed. According to the random number table method, 90 male SD rats were divided into ALI model group, phosphate buffer solution (PBS) group, EPCs treatment group, none transfected EPCs treatment group and VEGF165 transfected EPCs treatment group, and the rats in each group were subdivided into 4, 12 and 48 hours subgroups, with 6 rats in each subgroup. The rat model of ALI was reproduced by intravenous injection of oleic acid (0.15 μL/g). Then each treatment group was given PBS, EPCs, none transfected EPCs and VEGF165 transfected EPCs respectively with the same volume of 0.2 mL. For the groups with cells, about 1×10 6 cells were contained. Abdominal aortic blood and lung tissue were harvested at 4, 12 and 48 hours. Arterial blood gas analysis was performed. The lung wet/dry weight ratio (W/D) was calculated. The expressions of induced nitric oxide synthase (iNOS), endothelin-1 (ET-1) and VEGF165 were determined by enzyme-linked immunosorbent assay (ELISA). After dyed with hematoxylin-eosin (HE), the lung tissue pathology was observed and the lung injury score was performed. Compared with the ALI model group, the arterial partial pressure of oxygen (PaO 2 ) in EPCs, none transfected EPCs and VEGF165 transfected EPCs treatment groups was significantly increased from 4 hours, and lung W/D, expressions of iNOS and ET-1 were significantly decreased, and VEGF165 expression was significantly increased. Compared with the EPCs treatment group, the increase in PaO 2 , the decrease in lung W/D and expressions of iNOS and ET-1, and the increase in VEGF165 expression in VEGF165 transfected EPCs

Co-transplantation of plasmid-transfected myoblasts and myotubes into rat brains enables high levels of gene expression long-term

NASA Technical Reports Server (NTRS)

Jiao, S.; Williams, P.; Safda, N.; Schultz, E.; Wolff, J. A.

1993-01-01

We have previously proposed the use of primary muscle cells as a "platform," or "vehicle" for intracerebral transgene expression. Brain grafts of minced muscle, or cultured muscle cells persisted in rat brains for at least 6 mo without any decrease in graft size, or tumor formation. Stable, but moderate levels of intracerebral transgene expression were obtained by transplanting plasmid-transfected myotubes in culture. In the present study, high and stable levels of intracerebral transgene expression were achieved by the co-transplantation of plasmid-transfected myoblasts and myotubes in culture. Approximately 5 X 10(5) myoblasts and myotubes were transfected with 10 micrograms pRSVL plasmid DNA, and 30 micrograms Lipofectin (BRL), respectively. They were mixed together (total cell number was 1 million), and stereotactically injected into the caudate nucleus of an adult rat brain. The activity of luciferase, the product of transgene expression, was stable for at least 4 mo, and much higher than the levels in myotube grafts, or co-grafts of myoblasts and minced muscle. Presumably, the myotubes served as a framework on which the myoblasts can form myotubes. The sections of brains transplanted with co-graft of myoblasts, and myotubes transfected with pRSVLac-Z were stained immunofluorescently for beta-galactosidase activity. The muscle grafts contained beta-galactosidase positive myofibers 4 mo after transplantation. Such high and stable levels of in vivo expression after postnatal gene transfer have rarely been achieved. Primary muscle cells are useful vehicle for transgene expression in brains, and potentially valuable for gene therapy of degenerative neurological disorders.

Inhibition of breast cancer metastasis by co-transfection of miR-31/193b-mimics

PubMed Central

Hashemi, Zahra Sadat; Moghadam, Mehdi Forouzandeh; Farokhimanesh, Samila; Rajabibazl, Masoumeh; Sadroddiny, Esmaeil

2018-01-01

Objective(s): Various studies have been conducted to reduce the metastatic behavior of cancerous cells. In this regard, ectopic expression of anti-metastatic microRNAs by miR-mimic and miR-restoration-based therapies could bring new insights to the field. In the present study, the consequences of co-transfecting breast cancer cell lines with miR-193b and miR-31 were investigated via invasion and migration assays. Materials and Methods: Double stranded oligonucleotide of mature miR-193b-3p and miR-31-5p were cloned into pcDNA 6.2gw/EmGFP plasmid. The resulting plasmids were used for transfection. Real time-PCR was performed to assess the expression of miR-193b and miR-31 as well as Ras homolog gene family member A (RhoA) and urokinase-type plasminogen activator (uPA) as miR targets. Scratch, Transwell migration and Matrigel invasion assays were carried out to assess the extent of migration and invasion of cell lines. Results: The most significant increase in expression of miRs belonged to the single transfection of mimic-miRs in MDA-MB231. Although the co-transfection was not as successful as single transfection in miR expression, it was significantly more effective in inhibition of the cells invasive potential. Conclusion: Although the miR-restoration therapy based on co-transfection of two miRs could be less effective in expression of each miRNA, the resulting decrease in metastatic behavior of the cells is more significant due to collective effect of co-transfection to decrease target gene expression. Our results revealed that employing this sort of combinatorial strategies could lead to more efficient reduction in metastatic behavior. It seems that using this strategy would bring about more successful therapeutic outcomes. PMID:29796229

Targeted retrograde transfection of adenovirus vector carrying brain-derived neurotrophic factor gene prevents loss of mouse (twy/twy) anterior horn neurons in vivo sustaining mechanical compression.

PubMed

Xu, Kan; Uchida, Kenzo; Nakajima, Hideaki; Kobayashi, Shigeru; Baba, Hisatoshi

2006-08-01

Immunohistochemical analysis after adenovirus (AdV)-mediated BDNF gene transfer in and around the area of mechanical compression in the cervical spinal cord of the hyperostotic mouse (twy/twy). To investigate the neuroprotective effect of targeted AdV-BDNF gene transfection in the twy mouse with spontaneous chronic compression of the spinal cord motoneurons. Several studies reported the neuroprotective effects of neurotrophins on injured spinal cord. However, no report has described the effect of targeted retrograde neurotrophic gene delivery on motoneuron survival in chronic compression lesions of the cervical spinal cord resembling lesions of myelopathy. LacZ marker gene using adenoviral vector (AdV-LacZ) was used to evaluate retrograde delivery from the sternomastoid muscle in adult twy mice (16-week-old) and (control). Four weeks after the AdV-LacZ or AdV-BDNF injection, the compressed cervical spinal cord was removed en bloc for immunohistologic investigation of b-galactosidase activity and immunoreactivity and immunoblot analyses of BDNF. The number of anterior horn neurons was counted using Nissl, ChAT and AChE staining. Spinal accessory motoneurons between C1 and C3 segments were successfully transfected by AdV-LacZ in both twy and ICR mice after targeted intramuscular injection. Immunoreactivity to BDNF was significantly stronger in AdV-BDNF-gene transfected twy mice than in AdV-LacZ-gene transfected mice. At the cord level showing the maximum compression in AdV-BDNF-transfected twy mice, the number of anterior horn neurons was sinificantly higher in the topographic neuronal cell counting of Nissl-, ChAT-, and AChE-stained samples than in AdV-LacZ-injected twy mice. Targeted AdV-BDNF-gene delivery significantly increased Nissl-stained anterior horn neurons and enhanced cholinergic enzyme activities in the twy. Our results suggest that targeted retrograde AdV-BDNF-gene in vivo delivery may enhance neuronal survival even under chronic mechanical compression.

Mechanism of attenuation of a chimeric influenza A/B transfectant virus.

PubMed

Luo, G; Bergmann, M; Garcia-Sastre, A; Palese, P

1992-08-01

The ribonucleoprotein transfection system for influenza virus allowed us to construct an influenza A virus containing a chimeric neuraminidase (NA) gene in which the noncoding sequence is derived from the NS gene of influenza B virus (T. Muster, E. K. Subbarao, M. Enami, B. P. Murphy, and P. Palese, Proc. Natl. Acad. Sci. USA 88:5177-5181, 1991). This transfectant virus is attenuated in mice and grows to lower titers in tissue culture than wild-type virus. Since such a virus has characteristics desirable for a live attenuated vaccine strain, attempts were made to characterize this virus at the molecular level. Our analysis suggests that the attenuation of the virus is due to changes in the cis signal sequences, which resulted in a reduction of transcription and replication of the chimeric NA gene. The major finding concerns a sixfold reduction in NA-specific viral RNA in the virion, causing a reduction in the ratio of infectious particles to physical particles compared with the ratio in wild-type virus. Although the NA-specific mRNA level is also reduced in transfectant virus-infected cells, it does not appear to contribute to the attenuation characteristics of the virus. The levels of the other RNAs and their expression appear to be unchanged for the transfectant virus. It is suggested that downregulation of the synthesis of one viral RNA segment leads to the generation of defective viruses during each replication cycle. We believe that this represents a general principle for attenuation which may be applied to other segmented viruses containing either single-stranded or double-stranded RNA.

Efficient gene transfection to the brain with ultrasound irradiation in mice using stabilized bubble lipopolyplexes prepared by the surface charge regulation method.

PubMed

Ogawa, Koki; Fuchigami, Yuki; Hagimori, Masayori; Fumoto, Shintaro; Miura, Yusuke; Kawakami, Shigeru

2018-01-01

We previously developed anionic ternary bubble lipopolyplexes, an ultrasound-responsive carrier, expecting safe and efficient gene transfection. However, bubble lipopolyplexes have a low capacity for echo gas (C 3 F 8 ) encapsulation (EGE) in nonionic solution such as 5% glucose. On the other hand, we were able to prepare bubble lipopolyplexes by inserting phosphate-buffered saline before C 3 F 8 encapsulation. Surface charge regulation (SCR) by electrolytes stabilizes liposome/plasmid DNA (pDNA) complexes by accelerated membrane fusion. Considering these facts, we hypothesized that SCR by electrolytes such as NaCl would promote C 3 F 8 encapsulation in bubble lipopolyplexes mediated by accelerated membrane fusion. We defined this hypothesis as SCR-based EGE (SCR-EGE). Bubble lipopolyplexes prepared by the SCR-EGE method (SCR-EGE bubble lipopolyplexes) are expected to facilitate the gene transfection because of the high amount of C 3 F 8 . Therefore, we applied these methods for gene delivery to the brain and evaluated the characteristics of transgene expression in the brain. First, we measured the encapsulation efficiency of C 3 F 8 in SCR-EGE bubble lipopolyplexes. Next, we applied these bubble lipopolyplexes to the mouse brain; then, we evaluated the transfection efficiency. Furthermore, three-dimensional transgene distribution was observed using multicolor deep imaging. SCR-EGE bubble lipopolyplexes had a higher C 3 F 8 content than conventional bubble lipopolyplexes. In terms of safety, SCR-EGE bubble lipopolyplexes possessed an anionic potential and showed no aggregation with erythrocytes. After applying SCR-EGE bubble lipopolyplexes to the brain, high transgene expression was observed by combining with ultrasound irradiation. As a result, transgene expression mediated by SCR-EGE bubble lipopolyplexes was observed mainly on blood vessels and partially outside of blood vessels. The SCR-EGE method may promote C 3 F 8 encapsulation in bubble lipopolyplexes, and

[Expression patterns of non-viral transfection with GFP in the organ of Corti in vitro and in vivo. Gene therapy of the inner ear with non-viral vectors].

PubMed

Praetorius, M; Pfannenstiel, S; Klingmann, C; Baumann, I; Plinkert, P K; Staecker, H

2008-05-01

Diseases of the inner ear such as presbycusis, tinnitus, sudden hearing loss, and vertigo affect many patients, but so far there are no specific therapy options. Gene therapy might become a potential modality of treatment. Viral vectors are standard in animal models to date. Future considerations, however, call for a further evaluation of non-viral transfection methods. The non-viral transfection agents Metafectene, Superfect, Effectene, and Mirus TransIT were incubated with a plasmid coding for GFP. In vivo, the plasmid-agent mix was injected via the membrane of the round window, and 48 h later the inner ear was perfused, harvested, decalcified, and histologically evaluated for GFP expression. Cationic lipids (Metafectene) and dendrimers (Superfect) were able to transfect cells in the area of the organ of Corti and lead to GFP expression. The polyamine (Mirus TransIT) did show expression of GFP in the area of Rosenthal's canal and in the area of the inner hair cell. The combination of a non-liposomal lipid with a DNA condensing component (Effectene) did not show transfection of the organ of Corti. In the area of the spiral ganglia cells, GFP expression was seen with all the transfection agents. Non-viral transfection agents are able to introduce a reporter gene in cells of the inner ear in vitro and in vivo. There are, however, differences in the efficiency of the transfection. They might be an alternative in gene therapy of the inner ear. Further investigations to elucidate their potential are needed.

Large-Scale Transient Transfection of Chinese Hamster Ovary Cells in Suspension.

PubMed

Rajendra, Yashas; Balasubramanian, Sowmya; Hacker, David L

2017-01-01

We describe a one-liter transfection of suspension-adapted Chinese hamster ovary (CHO-DG44) cells using polyethyleneimine (PEI) for DNA delivery. The method involves transfection at a high cell density (5 × 10 6 cells/mL) by direct addition of plasmid DNA (pDNA) and PEI to the culture and subsequent incubation at 31 °C with agitation by orbital shaking. We also describe an alternative method in which 90% of the pDNA is replaced by nonspecific (filler) DNA, and the production phase is performed at 31 °C in the presence of 0.25% N, N-dimethylacetamide (DMA).

Tripartite polyionic complex (PIC) micelles as non-viral vectors for mesenchymal stem cell siRNA transfection.

PubMed

Raisin, Sophie; Morille, Marie; Bony, Claire; Noël, Danièle; Devoisselle, Jean-Marie; Belamie, Emmanuel

2017-08-22

In the context of regenerative medicine, the use of RNA interference mechanisms has already proven its efficiency in targeting specific gene expression with the aim of enhancing, accelerating or, more generally, directing stem cell differentiation. However, achievement of good transfection levels requires the use of a gene vector. For in vivo applications, synthetic vectors are an interesting option to avoid possible issues associated with viral vectors (safety, production costs, etc.). Herein, we report on the design of tripartite polyionic complex micelles as original non-viral polymeric vectors suited for mesenchymal stem cell transfection with siRNA. Three micelle formulations were designed to exhibit pH-triggered disassembly in an acidic pH range comparable to that of endosomes. One formulation was selected as the most promising with the highest siRNA loading capacity while clearly maintaining pH-triggered disassembly properties. A thorough investigation of the internalization pathway of micelles into cells with tagged siRNA was made before showing an efficient inhibition of Runx2 expression in primary bone marrow-derived stem cells. This work evidenced PIC micelles as promising synthetic vectors that allow efficient MSC transfection and control over their behavior, from the perspective of their clinical use.

Single-cell optoporation and transfection using femtosecond laser and optical tweezers.

PubMed

Waleed, Muhammad; Hwang, Sun-Uk; Kim, Jung-Dae; Shabbir, Irfan; Shin, Sang-Mo; Lee, Yong-Gu

2013-01-01

In this paper, we demonstrate a new single-cell optoporation and transfection technique using a femtosecond Gaussian laser beam and optical tweezers. Tightly focused near-infrared (NIR) femtosecond laser pulse was employed to transiently perforate the cellular membrane at a single point in MCF-7 cancer cells. A distinct technique was developed by trapping the microparticle using optical tweezers to focus the femtosecond laser precisely on the cell membrane to puncture it. Subsequently, an external gene was introduced in the cell by trapping and inserting the same plasmid-coated microparticle into the optoporated cell using optical tweezers. Various experimental parameters such as femtosecond laser exposure power, exposure time, puncture hole size, exact focusing of the femtosecond laser on the cell membrane, and cell healing time were closely analyzed to create the optimal conditions for cell viability. Following the insertion of plasmid-coated microparticles in the cell, the targeted cells exhibited green fluorescent protein (GFP) under the fluorescent microscope, hence confirming successful transfection into the cell. This new optoporation and transfection technique maximizes the level of selectivity and control over the targeted cell, and this may be a breakthrough method through which to induce controllable genetic changes in the cell.

The sustained-release behavior and in vitro and in vivo transfection of pEGFP-loaded core-shell-structured chitosan-based composite particles

PubMed Central

Wang, Yun; Lin, Fu-xing; Zhao, Yu; Wang, Mo-zhen; Ge, Xue-wu; Gong, Zheng-xing; Bao, Dan-dan; Gu, Yu-fang

2014-01-01

Novel submicron core-shell-structured chitosan-based composite particles encapsulated with enhanced green fluorescent protein plasmids (pEGFP) were prepared by complex coacervation method. The core was pEGFP-loaded thiolated N-alkylated chitosan (TACS) and the shell was pH- and temperature-responsive hydroxybutyl chitosan (HBC). pEGFP-loaded TACS-HBC composite particles were spherical, and had a mean diameter of approximately 120 nm, as measured by transmission electron microscopy and particle size analyzer. pEGFP showed sustained release in vitro for >15 days. Furthermore, in vitro transfection in human embryonic kidney 293T and human cervix epithelial cells, and in vivo transfection in mice skeletal muscle of loaded pEGFP, were investigated. Results showed that the expression of loaded pEGFP, both in vitro and in vivo, was slow but could be sustained over a long period. pEGFP expression in mice skeletal muscle was sustained for >60 days. This work indicates that these submicron core-shell-structured chitosan-based composite particles could potentially be used as a gene vector for in vivo controlled gene transfection. PMID:25364253

The sustained-release behavior and in vitro and in vivo transfection of pEGFP-loaded core-shell-structured chitosan-based composite particles.

PubMed

Wang, Yun; Lin, Fu-xing; Zhao, Yu; Wang, Mo-zhen; Ge, Xue-wu; Gong, Zheng-xing; Bao, Dan-dan; Gu, Yu-fang

2014-01-01

Novel submicron core-shell-structured chitosan-based composite particles encapsulated with enhanced green fluorescent protein plasmids (pEGFP) were prepared by complex coacervation method. The core was pEGFP-loaded thiolated N-alkylated chitosan (TACS) and the shell was pH- and temperature-responsive hydroxybutyl chitosan (HBC). pEGFP-loaded TACS-HBC composite particles were spherical, and had a mean diameter of approximately 120 nm, as measured by transmission electron microscopy and particle size analyzer. pEGFP showed sustained release in vitro for >15 days. Furthermore, in vitro transfection in human embryonic kidney 293T and human cervix epithelial cells, and in vivo transfection in mice skeletal muscle of loaded pEGFP, were investigated. Results showed that the expression of loaded pEGFP, both in vitro and in vivo, was slow but could be sustained over a long period. pEGFP expression in mice skeletal muscle was sustained for >60 days. This work indicates that these submicron core-shell-structured chitosan-based composite particles could potentially be used as a gene vector for in vivo controlled gene transfection.

Pressure-Mediated Oligonucleotide Transfection of Rat and Human Cardiovascular Tissues

NASA Astrophysics Data System (ADS)

Mann, Michael J.; Gibbons, Gary H.; Hutchinson, Howard; Poston, Robert S.; Hoyt, E. Grant; Robbins, Robert C.; Dzau, Victor J.

1999-05-01

The application of gene therapy to human disease is currently restricted by the relatively low efficiency and potential hazards of methods of oligonucleotide or gene delivery. Antisense or transcription factor decoy oligonucleotides have been shown to be effective at altering gene expression in cell culture expreriments, but their in vivo application is limited by the efficiency of cellular delivery, the intracellular stability of the compounds, and their duration of activity. We report herein the development of a highly efficient method for naked oligodeoxynucleotide (ODN) transfection into cardiovascular tissues by using controlled, nondistending pressure without the use of viral vectors, lipid formulations, or exposure to other adjunctive, potentially hazardous substances. In this study, we have documented the ability of ex vivo, pressure-mediated transfection to achieve nuclear localization of fluorescent (FITC)-labeled ODN in approximately 90% and 50% of cells in intact human saphenous vein and rat myocardium, respectively. We have further documented that pressure-mediated delivery of antisense ODN can functionally inhibited target gene expression in both of these tissues in a sequence-specific manner at the mRNA and protein levels. This oligonucleotide transfection system may represent a safe means of achieving the intraoperative genetic engineering of failure-resistant human bypass grafts and may provide an avenue for the genetic manipulation of cardiac allograft rejection, allograft vasculopathy, or other transplant diseases.

Exogenous Nkx2.5- or GATA-4-transfected rabbit bone marrow mesenchymal stem cells and myocardial cell co-culture on the treatment of myocardial infarction in rabbits.

PubMed

Li, Pu; Zhang, Lei

2015-08-01

The present study aimed to investigate the effects of Nkx2.5 or GATA-4 transfection with myocardial extracellular environment co-culture on the transformation of bone marrow mesenchymal stem cells (BMSCs) into differentiated cardiomyocytes. Nkx2.5 or GATA-4 were transfected into myocardial extracellular environment co-cultured BMSCs, and then injected into the periphery of infarcted myocardium of a myocardial infarction rabbit model. The effects of these gene transfections and culture on the infarcted myocardium were observed and the results may provide an experimental basis for the efficient myocardial cell differentiation of BMSCs. The present study also suggested that these cells may provide a source and clinical basis for myocardial injury repair via stem cell transplantation. The present study examined whether Nkx2.5 or GATA-4 exogenous gene transfection with myocardial cell extracellular environment co-culture were able to induce the differentiation of BMSCs into cardiac cells. In addition, the effect of these transfected BMSCs on the repair of the myocardium following myocardial infarction was determined using New Zealand rabbit models. The results demonstrated that myocardial cell differentiation was significantly less effective following exogenous gene transfection of Nkx2.5 or GATA-4 alone compared with that of transfection in combination with extracellular environment co-culture. In addition, the results of the present study showed that exogenous gene transfection of Nkx2.5 or GATA-4 into myocardial cell extracellular environment co-cultured BMSCs was able to significantly enhance the ability to repair, mitigating the death of myocardial cells and activation of the myocardium in rabbits with myocardial infarction compared with those of the rabbits transplanted with untreated BMSCs. In conclusion, the exogenous Nkx2.5 and GATA-4 gene transfection into myocardial extracellular environment co-cultured BMSCs induced increased differentiation into myocardial

Ultrasound-Mediated Vascular Gene Transfection by Cavitation of Endothelial-Targeted Cationic Microbubbles

PubMed Central

Xie, Aris; Belcik, Todd; Qi, Yue; Morgan, Terry K.; Champaneri, Shivam A.; Taylor, Sarah; Davidson, Brian P.; Zhao, Yan; Klibanov, Alexander L.; Kuliszewski, Michael A.; Leong-Poi, Howard; Ammi, Azzdine; Lindner, Jonathan R.

2013-01-01

OBJECTIVES Ultrasound-mediated gene delivery can be amplified by acoustic disruption of microbubble carriers that undergo cavitation. We hypothesized that endothelial targeting of microbubbles bearing cDNA is feasible and, through optimizing proximity to the vessel wall, increases the efficacy of gene transfection. BACKGROUND Contrast ultrasound-mediated gene delivery is a promising approach for site-specific gene therapy, although there are concerns with the reproducibility of this technique and the safety when using high-power ultrasound. METHODS Cationic lipid-shelled decafluorobutane microbubbles bearing a targeting moiety were prepared and compared with nontargeted microbubbles. Microbubble targeting efficiency to endothelial adhesion molecules (P-selectin or intercellular adhesion molecule [ICAM]-1) was tested using in vitro flow chamber studies, intravital microscopy of tumor necrosis factor-alpha (TNF-α)–stimulated murine cremaster muscle, and targeted contrast ultrasound imaging of P-selectin in a model of murine limb ischemia. Ultrasound-mediated transfection of luciferase reporter plasmid charge coupled to microbubbles in the post-ischemic hindlimb muscle was assessed by in vivo optical imaging. RESULTS Charge coupling of cDNA to the microbubble surface was not influenced by the presence of targeting ligand, and did not alter the cavitation properties of cationic microbubbles. In flow chamber studies, surface conjugation of cDNA did not affect attachment of targeted microbubbles at microvascular shear stresses (0.6 and 1.5 dyne/cm2). Attachment in vivo was also not affected by cDNA according to intravital microscopy observations of venular adhesion of ICAM-1–targeted microbubbles and by ultrasound molecular imaging of P-selectin–targeted microbubbles in the post-ischemic hindlimb in mice. Transfection at the site of high acoustic pressures (1.0 and 1.8 MPa) was similar for control and P-selectin–targeted microbubbles but was associated with

Lipid chain geometry of C14 glycerol-based lipids: effect on lipoplex structure and transfection.

PubMed

Kudsiova, Laila; Ho, Jimmy; Fridrich, Barbara; Harvey, Richard; Keppler, Melanie; Ng, Tony; Hart, Stephen L; Tabor, Alethea B; Hailes, Helen C; Lawrence, M Jayne

2011-02-01

The effects have been determined of a systematic alteration of the alkyl chain geometry of a C14 analogue of DOTMA on the detailed molecular architecture of the resulting cationic vesicles formed both in the absence and presence of 50 mol% DOPE, and of the lipoplexes prepared from these vesicles using either calf thymus or plasmid DNA. The C14 DOTMA analogues studied involved cis- or trans-double bonds at positions Δ9 or Δ11, and a compound (ALK) featuring an alkyne at position C9. For all of these analogues, examination by light scattering and neutron scattering, zeta potential measurement, and negative staining electron microscopy showed that there were no significant differences in the structures or charges of the vesicles or of the resulting lipoplexes, regardless of the nature of the DNA incorporated. Differences were observed, however, between the complexes formed by the various lipids when examining the extent of complexation and release by gel electrophoresis, where the E-lipids appeared to complex the DNA more efficiently than all other lipids tested. Moreover, the lipoplexes prepared from the E-lipids were the most effective in transfection of MDA-MB-231 breast cancer cells. As indicated through confocal microscopy studies, the E-lipids also showed a higher internalisation capacity and a more diffuse cellular distribution, possibly indicating a greater degree of endosomal escape and/or nuclear import. These observations suggest that the extent of complexation is the most important factor in determining the transfection efficiency of the complexes tested. At present it is unclear why the E-lipids were more effective at complexing DNA, although it is thought that the effective area per molecule occupied by the cationic lipid and DOPE head groups, and therefore the density of positive charges on the surface of the bilayer most closely matches the negative charge density of the DNA molecule. From a consideration of the geometry of the cationic lipids it is

Evaluation of FTA(®) card for the rescue of infectious foot-and-mouth disease virus by chemical transfection of extracted RNA in cultured cells.

PubMed

Biswal, Jitendra K; Subramaniam, Saravanan; Ranjan, Rajeev; Pattnaik, Bramhadev

2016-08-01

Foot-and-mouth disease (FMD) is a highly contagious epidemic disease of transboundary importance. Inadequate storage and shipment of suspected clinical samples can compromise the ability to detect and characterise FMD virus (FMDV) in endemic countries, thereby, leading to the loss of valuable virological and epidemiological data. This study, investigates the potential of using FTA(®) cards for dry transportation of clinical samples and subsequent recovery of infectious FMDV by chemical transfection of FTA(®) card fixed RNA as an alternative to the conventional cell culture based virus isolation method. A higher proportion of infectious FMDV was rescued from clinical samples (cell culture isolates, tongue epithelial suspension and impression smears) by the FTA(®) card fixed RNA transfection method (76%) compared to the conventional cell culture based virus isolation (56%), suggesting a better performance of the current RNA transfection procedure. Furthermore, it was possible to rescue live virus by the transfection of RNA extracted from FTA(®) card impregnated with clinical samples that had been stored at varying temperature (4-37 °C) up to a period of six weeks. The VP1 sequence data and antigenic relationships with the vaccine strains, between viruses rescued by FTA(®) card fixed RNA transfection and conventional cell culture, were comparable. Therefore, these results support the use of the FTA(®) card for the economic, dry, non-hazardous transport of FMD suspected clinical samples from the site of collection to national/international reference laboratories. Copyright © 2016 Elsevier Ltd. All rights reserved.

Differential polymer structure tunes mechanism of cellular uptake and transfection routes of poly(β-amino ester) polyplexes in human breast cancer cells.

PubMed

Kim, Jayoung; Sunshine, Joel C; Green, Jordan J

2014-01-15

Successful gene delivery with nonviral particles has several barriers, including cellular uptake, endosomal escape, and nuclear transport. Understanding the mechanisms behind these steps is critical to enhancing the effectiveness of gene delivery. Polyplexes formed with poly(β-amino ester)s (PBAEs) have been shown to effectively transfer DNA to various cell types, but the mechanism of their cellular uptake has not been identified. This is the first study to evaluate the uptake mechanism of PBAE polyplexes and the dependence of cellular uptake on the end group and molecular weight of the polymer. We synthesized three different analogues of PBAEs with the same base polymer poly(1,4-butanediol diacrylate-co-4-amino-1-butanol) (B4S4) but with small changes in the end group or molecular weight. We quantified the uptake and transfection efficiencies of the pDNA polyplexes formulated from these polymers in hard-to-transfect triple negative human breast cancer cells (MDA-MB 231). All polymers formed positively charged (10-17 mV) nanoparticles of ∼200 nm in size. Cellular internalization of all three formulations was inhibited the most (60-90% decrease in cellular uptake) by blocking caveolae-mediated endocytosis. Greater inhibition was shown with polymers that had a 1-(3-aminopropyl)-4-methylpiperazine end group (E7) than the others with a 2-(3-aminopropylamino)-ethanol end group (E6) or higher molecular weight. However, caveolae-mediated endocytosis was generally not as efficient as clathrin-mediated endocytosis in leading to transfection. These findings indicate that PBAE polyplexes can be used to transfect triple negative human breast cancer cells and that small changes to the same base polymer can modulate their cellular uptake and transfection routes.

Incorporation of Viral Glycoprotein VSV-G Improves the Delivery of DNA by Erythrocyte Ghost into Cells Refractory to Conventional Transfection.

PubMed

Liu, Xin; Li, Yun-Pan; Zhong, Zhen-Min; Tan, Hui-Qi; Lin, Hao-Peng; Chen, Shao-Jun; Fu, Yu-Cai; Xu, Wen-Can; Wei, Chi-Ju

2017-02-01

The objective of this study was to formulate a novel gene delivery system based on the erythrocyte ghost (EG) integrated with fusogenic viral glycoprotein vesicular stomatitis virus glycoprotein G (VSV-G). VSV-G proteins were harvested as condition medium of Ad293 cells carrying a VSV-G transgene and then incorporated into EG. Plasmid DNA was condensed by various transfection reagents. A luciferase expression construct (pGL3-control) and a DsRed expression cassette (pCMV-DsRed) were used to evaluate the delivery efficiency of DNA/EG/VSV-G complexes. VSV-G proteins could be incorporated into EG in static incubation under acidic conditions as evidenced by the Western blot analysis. Condensed plasmid DNA was bound mostly to the outer surface of EG, which could be detected by electromicroscopy and measured by electrophoresis. EG/VSV-G complexes stimulated the delivery of pGL3-control into Ad293 cells significantly with the luciferase activity increased about 4-fold as compared to that of the control. The delivery of pCMV-DsRed was also enhanced with the percentage of DsRed-positive Ad293 cells increased from 55 % to about 80 %. Moreover, the transfection efficiency in 3T3, HeLa, INS-1, and bone marrow stem cell (BMSC) cells increased about 2-3-fold. Finally, confocal microscopy analysis showed that incorporation of VSV-G significantly enhanced the endocytosis of EG into target cells. In the present study, a novel type of non-viral DNA delivery vehicle consisting of EG and fusogenic VSV-G proteins was formulated, which showed superior transfection efficiency even in cells resistant to classical transfection.

Transfection effect of microbubbles on cells in superposed ultrasound waves and behavior of cavitation bubble.

PubMed

Kodama, Tetsuya; Tomita, Yukio; Koshiyama, Ken-Ichiro; Blomley, Martin J K

2006-06-01

The combination of ultrasound and ultrasound contrast agents (UCAs) is able to induce transient membrane permeability leading to direct delivery of exogenous molecules into cells. Cavitation bubbles are believed to be involved in the membrane permeability; however, the detailed mechanism is still unknown. In the present study, the effects of ultrasound and the UCAs, Optison on transfection in vitro for different medium heights and the related dynamic behaviors of cavitation bubbles were investigated. Cultured CHO-E cells mixed with reporter genes (luciferase or beta-gal plasmid DNA) and UCAs were exposed to 1 MHz ultrasound in 24-well plates. Ultrasound was applied from the bottom of the well and reflected at the free surface of the medium, resulting in the superposition of ultrasound waves within the well. Cells cultured on the bottom of 24-well plates were located near the first node (displacement node) of the incident ultrasound downstream. Transfection activity was a function determined with the height of the medium (wave traveling distance), as well as the concentration of UCAs and the exposure time was also determined with the concentration of UCAs and the exposure duration. Survival fraction was determined by MTT assay, also changes with these values in the reverse pattern compared with luciferase activity. With shallow medium height, high transfection efficacy and high survival fraction were obtained at a low concentration of UCAs. In addition, capillary waves and subsequent atomized particles became significant as the medium height decreased. These phenomena suggested cavitation bubbles were being generated in the medium. To determine the effect of UCAs on bubble generation, we repeated the experiments using crushed heat-treated Optison solution instead of the standard microbubble preparation. The transfection ratio and survival fraction showed no additional benefit when ultrasound was used. These results suggested that cavitation bubbles created by the

Optimization of input parameters of acoustic-transfection for the intracellular delivery of macromolecules using FRET-based biosensors

NASA Astrophysics Data System (ADS)

Yoon, Sangpil; Wang, Yingxiao; Shung, K. K.

2016-03-01

Acoustic-transfection technique has been developed for the first time. We have developed acoustic-transfection by integrating a high frequency ultrasonic transducer and a fluorescence microscope. High frequency ultrasound with the center frequency over 150 MHz can focus acoustic sound field into a confined area with the diameter of 10 μm or less. This focusing capability was used to perturb lipid bilayer of cell membrane to induce intracellular delivery of macromolecules. Single cell level imaging was performed to investigate the behavior of a targeted single-cell after acoustic-transfection. FRET-based Ca2+ biosensor was used to monitor intracellular concentration of Ca2+ after acoustic-transfection and the fluorescence intensity of propidium iodide (PI) was used to observe influx of PI molecules. We changed peak-to-peak voltages and pulse duration to optimize the input parameters of an acoustic pulse. Input parameters that can induce strong perturbations on cell membrane were found and size dependent intracellular delivery of macromolecules was explored. To increase the amount of delivered molecules by acoustic-transfection, we applied several acoustic pulses and the intensity of PI fluorescence increased step wise. Finally, optimized input parameters of acoustic-transfection system were used to deliver pMax-E2F1 plasmid and GFP expression 24 hours after the intracellular delivery was confirmed using HeLa cells.

Transient transfection of serum-free suspension HEK 293 cell culture for efficient production of human rFVIII.

PubMed

Swiech, Kamilla; Kamen, Amine; Ansorge, Sven; Durocher, Yves; Picanço-Castro, Virgínia; Russo-Carbolante, Elisa M S; Neto, Mário S A; Covas, Dimas T

2011-11-24

Hemophilia A is a bleeding disorder caused by deficiency in coagulation factor VIII. Recombinant factor VIII (rFVIII) is an alternative to plasma-derived FVIII for the treatment of hemophilia A. However, commercial manufacturing of rFVIII products is inefficient and costly and is associated to high prices and product shortage, even in economically privileged countries. This situation may be solved by adopting more efficient production methods. Here, we evaluated the potential of transient transfection in producing rFVIII in serum-free suspension HEK 293 cell cultures and investigated the effects of different DNA concentration (0.4, 0.6 and 0.8 μg/106 cells) and repeated transfections done at 34° and 37 °C. We observed a decrease in cell growth when high DNA concentrations were used, but no significant differences in transfection efficiency and in the biological activity of the rFVIII were noticed. The best condition for rFVIII production was obtained with repeated transfections at 34 °C using 0.4 μg DNA/106 cells through which almost 50 IU of active rFVIII was produced six days post-transfection. Serum-free suspension transient transfection is thus a viable option for high-yield-rFVIII production. Work is in progress to further optimize the process and validate its scalability.

Transfection of Fv-1 permissive and restrictive mouse cells with integrated DNA of murine leukemia viruses

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

Hsu, I.C.; Yang, W.K.; Tennant, R.W.

1978-03-01

Whole-cell DNA preparations isolated from SC-1 cells chronically infected with N- or B-tropic murine leukemia viruses (MuLV) were tested for infectious activity in an Fv-I/sup n/ (NIH-3T3) and two Fv-I/sup b/ (C57BL/6 and SV-A31) cell cultures. Efficiency of transfection for all DNAs was better in the NIH-3T3 cells than in C57BL/6 or SV-A31 cells; and an (N-tropic MuLV)SC-1 cell DNA preparation was slightly more infectious than a (B-tropic MuLV)SC-1 cell DNA preparation in all three cell cultures, regardless of their Fv-1 genotypes. Progeny viruses from the transfection showed N- or B-tropism corresponding to that of the parent viruses produced bymore » the infected SC-1 cells that were used for the DNA preparation. DNA dose-response studies in NIH-3T3 cells revealed a one-hit mechanism for both the (B-tropic MuLV)SC-1 cell DNA and the (N-tropic MuLV)SC-1 cell DNA preparation. These results demonstrate that, in contrast to virion infection, transfection of N- and B-tropic MuLV with DNA preparations from chronically infected cells is not affected by the Fv-1 gene.« less

Increased expression of human leucocyte antigen class I free heavy chains on monocytes of patients with spondyloarthritis and cells transfected with HLA-B27.

PubMed

Ding, Jin; Feng, Yuan; Zheng, Zhao Hui; Li, Xue Yi; Wu, Zhen Biao; Zhu, Ping

2015-02-01

Human leucocyte antigen (HLA)-B27 expression is correlated with spondyloarthritis (SpA), but its role in disease pathogenesis remains unclear. The aim of the study was to determine whether HLA-B27 free heavy chain (FHC) contributes to SpA pathogenesis. Flow cytometry was used to analyse the FHC expression on CD3+ and CD14+ cells in the peripheral blood (PB) and synovial fluid (SF) from SpA patients, healthy controls, and rheumatoid arthritis (RA) patients. Human monocytic U937 cell lines stably expressing enhanced green fluorescence protein (EGFP)/HLA-B27, EGFP/HLA-A2 or EGFP alone were created to further investigate the relation between HLA-B27 and FHC expression. The relative FHC level on CD14+ PB cells was significantly higher in SpA patients than in controls, but lower than on the SF cells of SpA patients. No significant correlation was found for relative FHC expression with HLA-B27 or β2-microglobulin expression. HLA-B27-transfected U937 cells expressed higher FHC levels than either EGFP/HLA-A2- or EGFP-transfected cells. HLA class I FHC expression was significantly increased on monocytes of SpA patients and HLA-B27-transfected cells, implying that FHC, perhaps mostly derived from HLA-B27, plays an important role in SpA pathogenesis. © 2014 John Wiley & Sons Ltd.

Selective Gene Transfection of Individual Cells In Vitro with Plasmonic Nanobubbles

PubMed Central

Lukianova-Hleb, Ekaterina; Samaniego, Adam P.; Wen, Jianguo; Metelitsa, Leonid; Chang, Chung-Che; Lapotko, Dmitri

2011-01-01

Gene delivery and transfection of eukaryotic cells is widely used for research and for developing gene cell therapy. However, the existing methods lack selectivity, efficacy and safety when heterogeneous cell systems must be treated. We report a new method that employs plasmonic nanobubbles (PNBs) for delivery and transfection. A PNB is a novel, tunable cellular agent with a dual mechanical and optical action due to the formation of the vapor nanobubble around a transiently heated gold nanoparticle upon its exposure to a laser pulse. PNBs enabled the mechanical injection of the extracellular cDNA plasmid into the cytoplasm of individual target living cells, cultured leukemia cells and human CD34+CD117+ stem cells and expression of a green fluorescent protein (GFP) in those cells. PNB generation and lifetime correlated with the expression of green fluorescent protein in PNB-treated cells. Optical scattering by PNBs additionally provided the detection of the target cells and the guidance of cDNA injection at single cell level. In both cell models PNBs demonstrated a gene transfection effect in a single pulse treatment with high selectivity, efficacy and safety. Thus, PNBs provided targeted gene delivery at the single cell level in a single pulse procedure that can be used for safe and effective gene therapy. PMID:21315120

First siRNA library screening in hard-to-transfect HUVEC cells

PubMed Central

Zumbansen, Markus; Altrogge, Ludger M; Spottke, Nicole UE; Spicker, Sonja; Offizier, Sheila M; Domzalski, Sandra BS; St Amand, Allison L; Toell, Andrea; Leake, Devin; Mueller-Hartmann, Herbert A

2010-01-01

Meaningful RNAi-based data for target gene identification are strongly dependent on the use of a biologically relevant cell type and efficient delivery of highly functional siRNA reagents into the selected cell type. Here we report the use of the Amaxa® Nucleofector® 96-well Shuttle® System for siRNA screening in primary cells. Lonza's Clonetics® HUVEC-Human Umbilical Vein Endothelial Cells were transfected with Thermo Scientific Dharmacon siGENOME® siRNA Libraries targeting protein kinases and cell cycle related genes and screened for genes important for cell viability. Of the 37 primary hits, down-regulation of 33 led to reduced proliferation or increased cell death, while down-regulation of two allowed for better cell viability. The validated four genes out of the 16 strongest primary hits (COPB2, PYCS, CDK4 and MYC) influenced cell proliferation to varying degrees, reflecting differing importance for survival of HUVEC cells. Our results demonstrate that the Nucleofector® 96-well Shuttle® System allows the delivery of siRNA libraries in cell types previously considered to be difficult to transfect. Thus, identification and validation of gene targets can now be conducted in primary cells, as the selection of cell types is not limited to those accessible by lipid-mediated transfection. PMID:20628494

Peptide dendrimer/lipid hybrid systems are efficient DNA transfection reagents: structure--activity relationships highlight the role of charge distribution across dendrimer generations.

PubMed

Kwok, Albert; Eggimann, Gabriela A; Reymond, Jean-Louis; Darbre, Tamis; Hollfelder, Florian

2013-05-28

Efficient DNA delivery into cells is the prerequisite of the genetic manipulation of organisms in molecular and cellular biology as well as, ultimately, in nonviral gene therapy. Current reagents, however, are relatively inefficient, and structure-activity relationships to guide their improvement are hard to come by. We now explore peptide dendrimers as a new type of transfection reagent and provide a quantitative framework for their evaluation. A collection of dendrimers with cationic and hydrophobic amino acid motifs (such as KK, KA, KH, KL, and LL) distributed across three dendrimer generations was synthesized by a solid-phase protocol that provides ready access to dendrimers in milligram quantities. In conjunction with a lipid component (DOTMA/DOPE), the best reagent, G1,2,3-KL ((LysLeu)8(LysLysLeu)4(LysLysLeu)2LysGlySerCys-NH2), improves transfection by 6-10-fold over commercial reagents under their respective optimal conditions. Emerging structure-activity relationships show that dendrimers with cationic and hydrophobic residues distributed in each generation are transfecting most efficiently. The trigenerational dendritic structure has an advantage over a linear analogue worth up to an order of magnitude. The success of placing the decisive cationic charge patterns in inner shells rather than previously on the surface of macromolecules suggests that this class of dendrimers significantly differs from existing transfection reagents. In the future, this platform may be tuned further and coupled to cell-targeting moieties to enhance transfection and cell specificity.

Peptide Dendrimer/Lipid Hybrid Systems Are Efficient DNA Transfection Reagents: Structure–Activity Relationships Highlight the Role of Charge Distribution Across Dendrimer Generations

PubMed Central

2013-01-01

Efficient DNA delivery into cells is the prerequisite of the genetic manipulation of organisms in molecular and cellular biology as well as, ultimately, in nonviral gene therapy. Current reagents, however, are relatively inefficient, and structure–activity relationships to guide their improvement are hard to come by. We now explore peptide dendrimers as a new type of transfection reagent and provide a quantitative framework for their evaluation. A collection of dendrimers with cationic and hydrophobic amino acid motifs (such as KK, KA, KH, KL, and LL) distributed across three dendrimer generations was synthesized by a solid-phase protocol that provides ready access to dendrimers in milligram quantities. In conjunction with a lipid component (DOTMA/DOPE), the best reagent, G1,2,3-KL ((LysLeu)8(LysLysLeu)4(LysLysLeu)2LysGlySerCys-NH2), improves transfection by 6–10-fold over commercial reagents under their respective optimal conditions. Emerging structure–activity relationships show that dendrimers with cationic and hydrophobic residues distributed in each generation are transfecting most efficiently. The trigenerational dendritic structure has an advantage over a linear analogue worth up to an order of magnitude. The success of placing the decisive cationic charge patterns in inner shells rather than previously on the surface of macromolecules suggests that this class of dendrimers significantly differs from existing transfection reagents. In the future, this platform may be tuned further and coupled to cell-targeting moieties to enhance transfection and cell specificity. PMID:23682947

A serum-resistant polyamidoamine-based polypeptide dendrimer for gene transfection.

PubMed

Wu, H M; Pan, S R; Chen, M W; Wu, Y; Wang, C; Wen, Y T; Zeng, X; Wu, C B

2011-02-01

A serum tolerant polycation gene vector, G(2) PAMAM-PGlu-G(1) PAMAMs (ALA), was designed, synthesized, characterized and evaluated. A honeycomb-like molecular structure model for mechanistic explanation of ALA was postulated and discussed. Designed as a star-shaped polyamidoamine (PAMAM)-based polypeptide dendrimer through peptide bond linkages, ALA was with non-toxic low generation G(2) PAMAM (G(2)) as its central core, polyglutamate (PGlu)s as its star-shaped backbone branches and G(1) PAMAM (G(1))s as its branch grafts and peripheral terminals. IR, (1)H NMR demonstrated its successful combination. As a gene carrier, ALA exhibited good DNA binding and condensation capacity with particle size (approximately 87 nm for N/P 40, approximately 170 nm for N/P 30) and ζ-potential (approximately 16 mV for N/P 30-40), negligible cytotoxicity, exciting serum tolerant capacity and significant serum-promoted (serum-containing 56.6%>serum-free 32.7%), cell line dependent (Hek 293 > Bel 7402 > Hela), incubation period dependent (38 h > 18 h > 12 h > 9 h > 4 h > 2 h > 1 h) and sustained (peak transfection appeared at 30 h incubation) transfection efficiency. The presence of serum had not only no inhibition on, but also prominent promotion to, the transfection activity of ALA. All above features differentiated ALA clearly from most other serum-inhibitive nonviral gene carriers, and proved ALA the promising and challenging potential efficient gene vector for practical clinical application. 2010 Elsevier Ltd. All rights reserved.

Gene-carried hepatoma targeting complex induced high gene transfection efficiency with low toxicity and significant antitumor activity.

PubMed

Zhao, Qing-Qing; Hu, Yu-Lan; Zhou, Yang; Li, Ni; Han, Min; Tang, Gu-Ping; Qiu, Feng; Tabata, Yasuhiko; Gao, Jian-Qing

2012-01-01

The success of gene transfection is largely dependent on the development of a vehicle or vector that can efficiently deliver a gene to cells with minimal toxicity. A liver cancer-targeted specific peptide (FQHPSF sequence) was successfully synthesized and linked with chitosan-linked polyethylenimine (CP) to form a new targeted gene delivery vector called CPT (CP/peptide). The structure of CPT was confirmed by (1)H nuclear magnetic resonance spectroscopy and ultraviolet spectrophotometry. The particle size of CPT/ DNA complexes was measured using laser diffraction spectrometry and the cytotoxicity of the copolymer was evaluated by methylthiazol tetrazolium method. The transfection efficiency evaluation of the CP copolymer was performed using luciferase activity assay. Cellular internalization of the CP/DNA complex was observed under confocal laser scanning microscopy. The targeting specificity of the polymer coupled to peptide was measured by competitive inhibition transfection study. The liver targeting specificity of the CPT copolymer in vivo was demonstrated by combining the copolymer with a therapeutic gene, interleukin-12, and assessed by its abilities in suppressing the growth of ascites tumor in mouse model. The results showed that the liver cancer-targeted specific peptide was successfully synthesized and linked with CP to form a new targeted gene delivery vector called CPT. The composition of CPT was confirmed and the vector showed low cytotoxicity and strong targeting specificity to liver tumors in vitro. The in vivo study results showed that interleukin-12 delivered by the new gene vector CPT/DNA significantly enhanced the antitumor effect on ascites tumor-bearing imprinting control region mice as compared with polyethylenimine (25 kDa), CP, and other controls, which further demonstrate the targeting specificity of the new synthesized polymer. The synthesized CPT copolymer was proven to be an effective liver cancer-targeted vector for therapeutic gene

Transfection of Platyhelminthes.

PubMed

Moguel, Bárbara; Bobes, Raúl J; Carrero, Julio C; Laclette, Juan P

2015-01-01

Flatworms are one of the most diverse groups within Lophotrochozoa with more than 20,000 known species, distributed worldwide in different ecosystems, from the free-living organisms in the seas and lakes to highly specialized parasites living in a variety of hosts, including humans. Several infections caused by flatworms are considered major neglected diseases affecting countries in the Americas, Asia, and Africa. For several decades, a particular interest on free-living flatworms was due to their ability to regenerate considerable portions of the body, implying the presence of germ cells that could be important for medicine. The relevance of reverse genetics for this group is clear; understanding the phenotypic characteristics of specific genes will shed light on developmental traits of free-living and parasite worms. The genetic manipulation of flatworms will allow learning more about the mechanisms for tissue regeneration, designing new and more effective anthelmintic drugs, and explaining the host-parasite molecular crosstalk so far partially inaccessible for experimentation. In this review, availability of transfection techniques is analyzed across flatworms, from the initial transient achievements to the stable manipulations now developed for free-living and parasite species.

Quantitative Evaluation of Myostatin Gene in Stably Transfected Caprine Fibroblast Cells by Anti-Myostatin shRNA.

PubMed

Jain, Sudhir Kumar; Jain, Hemlata; Kumar, Dharmendra; Bedekar, Megha Kadam; Pandey, Akhilesh Kumar; Sarkhel, Bikash Chandra

2015-09-01

Skeletal muscle is the major component of lean tissue that is used for consumption, and myostatin is a negative regulator of skeletal muscle growth. Downregulation of this gene therefore offers a strategy for developing superior animals with enhanced muscle growth. Knockdown of myostatin was achieved by RNA interference technology. The anti-myostatin shRNA were designed and stably transfected in caprine fibroblast cells. The reduced expression of target gene was achieved and measured in clonal fibroblast cells by real-time PCR. Two single-cell clones induced significant decrease of myostatin gene expression by 73.96 and 72.66 %, respectively (P < 0.05). To ensure the appropriate growth of transfected cell, seven media were tested. The best suited media was used for transfected fibroblast cell proliferation. The findings suggest that shRNA provides a novel potential tool for gene knockdown and these stably transfected cells can be used as the donor cells for animal cloning.

Effects of Circular DNA Length on Transfection Efficiency by Electroporation into HeLa Cells.

PubMed

Hornstein, Benjamin D; Roman, Dany; Arévalo-Soliz, Lirio M; Engevik, Melinda A; Zechiedrich, Lynn

2016-01-01

The ability to produce extremely small and circular supercoiled vectors has opened new territory for improving non-viral gene therapy vectors. In this work, we compared transfection of supercoiled DNA vectors ranging from 383 to 4,548 bp, each encoding shRNA against GFP under control of the H1 promoter. We assessed knockdown of GFP by electroporation into HeLa cells. All of our vectors entered cells in comparable numbers when electroporated with equal moles of DNA. Despite similar cell entry, we found length-dependent differences in how efficiently the vectors knocked down GFP. As vector length increased up to 1,869 bp, GFP knockdown efficiency per mole of transfected DNA increased. From 1,869 to 4,257 bp, GFP knockdown efficiency per mole was steady, then decreased with increasing vector length. In comparing GFP knockdown with equal masses of vectors, we found that the shorter vectors transfect more efficiently per nanogram of DNA transfected. Our results rule out cell entry and DNA mass as determining factors for gene knockdown efficiency via electroporation. The length-dependent effects we have uncovered are likely explained by differences in nuclear translocation or transcription. These data add an important step towards clinical applications of non-viral vector delivery.

Effects of Circular DNA Length on Transfection Efficiency by Electroporation into HeLa Cells

PubMed Central

Hornstein, Benjamin D.; Roman, Dany; Arévalo-Soliz, Lirio M.; Engevik, Melinda A.

2016-01-01

The ability to produce extremely small and circular supercoiled vectors has opened new territory for improving non-viral gene therapy vectors. In this work, we compared transfection of supercoiled DNA vectors ranging from 383 to 4,548 bp, each encoding shRNA against GFP under control of the H1 promoter. We assessed knockdown of GFP by electroporation into HeLa cells. All of our vectors entered cells in comparable numbers when electroporated with equal moles of DNA. Despite similar cell entry, we found length-dependent differences in how efficiently the vectors knocked down GFP. As vector length increased up to 1,869 bp, GFP knockdown efficiency per mole of transfected DNA increased. From 1,869 to 4,257 bp, GFP knockdown efficiency per mole was steady, then decreased with increasing vector length. In comparing GFP knockdown with equal masses of vectors, we found that the shorter vectors transfect more efficiently per nanogram of DNA transfected. Our results rule out cell entry and DNA mass as determining factors for gene knockdown efficiency via electroporation. The length-dependent effects we have uncovered are likely explained by differences in nuclear translocation or transcription. These data add an important step towards clinical applications of non-viral vector delivery. PMID:27918590

Co-liposomes having anisamide tagged lipid and cholesteryl tryptophan trigger enhanced gene transfection in sigma receptor positive cells.

PubMed

Misra, Santosh K; Moitra, Parikshit; Kondaiah, Paturu; Bhattacharya, Santanu

2016-06-01

Selective gene transfection could be strategy of interest for reducing off-target gene expression and toxicity. In this respect, sigma receptors are found to be over-expressed in many human tumors and liposomal formulations with ability to target these sigma receptors may improve the transfection efficiency to a significant level. To this direction, six novel lipids have been synthesized with different hydrophobic segments such as a long hydrophobic chain or a cholesteryl group and L-tryptophan as the head group. Three of them, Lipid 1, 3 and 5 possessed cationic Me3N(+) moiety at the distal end. In contrast each of the other three Lipid 2, 4 and 6 possessed sigma receptor targeting anisamide group with no cationic charge. Mixing of cationic and anisamide counterparts of the same lipid in a molar ratio of 1:1 produced co-liposomes L-M-1 (Lipid 1+2), L-M-2 (Lipid 3+4) and L-M-3 (Lipid 5+6). These co-liposomes, while keeping the sigma targeting anisamide tag intact, showed good DNA binding and release which were optimized from EB intercalation and gel electrophoresis assays. Inclusion of a zwitterionic, fusogenic natural lipid, DOPE, into the co-liposomes further improved the binding efficiencies of the lipid mixtures with DNA. These co-liposomes having cationic and anisamide lipids and DOPE were highly selective toward sigma positive HEK293 and HEK293T cells compared to the sigma negative HeLa cells. As evidenced from both FACS and luciferase assay, a lipid mixture comprising Lipid 3, 4 and DOPE in a molar ratio of 1:1:1 (L-M-2D1) was the best for transfection of reporter pEGFP-C3 and functional pCEP4-p53 gene plasmids. Anisamide mediated sigma receptor selectivity was further probed by pre-incubating the transfecting cells with lipids possessing anisamide and by quantification of the un-transfected plasmid DNA. Also each formulation was highly non-toxic in the cell lines examined. Copyright © 2016. Published by Elsevier B.V.

Peptide-enhanced mRNA transfection in cultured mouse cardiac fibroblasts and direct reprogramming towards cardiomyocyte-like cells

PubMed Central

Lee, Kunwoo; Yu, Pengzhi; Lingampalli, Nithya; Kim, Hyun Jin; Tang, Richard; Murthy, Niren

2015-01-01

The treatment of myocardial infarction is a major challenge in medicine due to the inability of heart tissue to regenerate. Direct reprogramming of endogenous cardiac fibroblasts into functional cardiomyocytes via the delivery of transcription factor mRNAs has the potential to regenerate cardiac tissue and to treat heart failure. Even though mRNA delivery to cardiac fibroblasts has the therapeutic potential, mRNA transfection in cardiac fibroblasts has been challenging. Herein, we develop an efficient mRNA transfection in cultured mouse cardiac fibroblasts via a polyarginine-fused heart-targeting peptide and lipofectamine complex, termed C-Lipo and demonstrate the partial direct reprogramming of cardiac fibroblasts towards cardiomyocyte cells. C-Lipo enabled the mRNA-induced direct cardiac reprogramming due to its efficient transfection with low toxicity, which allowed for multiple transfections of Gata4, Mef2c, and Tbx5 (GMT) mRNAs for a period of 2 weeks. The induced cardiomyocyte-like cells had α-MHC promoter-driven GFP expression and striated cardiac muscle structure from α-actinin immunohistochemistry. GMT mRNA transfection of cultured mouse cardiac fibroblasts via C-Lipo significantly increased expression of the cardiomyocyte marker genes, Actc1, Actn2, Gja1, Hand2, and Tnnt2, after 2 weeks of transfection. Moreover, this study provides the first direct evidence that the stoichiometry of the GMT reprogramming factors influence the expression of cardiomyocyte marker genes. Our results demonstrate that mRNA delivery is a potential approach for cardiomyocyte generation. PMID:25834424

Ultrasound-mediated vascular gene transfection by cavitation of endothelial-targeted cationic microbubbles.

PubMed

Xie, Aris; Belcik, Todd; Qi, Yue; Morgan, Terry K; Champaneri, Shivam A; Taylor, Sarah; Davidson, Brian P; Zhao, Yan; Klibanov, Alexander L; Kuliszewski, Michael A; Leong-Poi, Howard; Ammi, Azzdine; Lindner, Jonathan R

2012-12-01

Ultrasound-mediated gene delivery can be amplified by acoustic disruption of microbubble carriers that undergo cavitation. We hypothesized that endothelial targeting of microbubbles bearing cDNA is feasible and, through optimizing proximity to the vessel wall, increases the efficacy of gene transfection. Contrast ultrasound-mediated gene delivery is a promising approach for site-specific gene therapy, although there are concerns with the reproducibility of this technique and the safety when using high-power ultrasound. Cationic lipid-shelled decafluorobutane microbubbles bearing a targeting moiety were prepared and compared with nontargeted microbubbles. Microbubble targeting efficiency to endothelial adhesion molecules (P-selectin or intercellular adhesion molecule [ICAM]-1) was tested using in vitro flow chamber studies, intravital microscopy of tumor necrosis factor-alpha (TNF-α)-stimulated murine cremaster muscle, and targeted contrast ultrasound imaging of P-selectin in a model of murine limb ischemia. Ultrasound-mediated transfection of luciferase reporter plasmid charge coupled to microbubbles in the post-ischemic hindlimb muscle was assessed by in vivo optical imaging. Charge coupling of cDNA to the microbubble surface was not influenced by the presence of targeting ligand, and did not alter the cavitation properties of cationic microbubbles. In flow chamber studies, surface conjugation of cDNA did not affect attachment of targeted microbubbles at microvascular shear stresses (0.6 and 1.5 dyne/cm(2)). Attachment in vivo was also not affected by cDNA according to intravital microscopy observations of venular adhesion of ICAM-1-targeted microbubbles and by ultrasound molecular imaging of P-selectin-targeted microbubbles in the post-ischemic hindlimb in mice. Transfection at the site of high acoustic pressures (1.0 and 1.8 MPa) was similar for control and P-selectin-targeted microbubbles but was associated with vascular rupture and hemorrhage. At 0.6 MPa

Selective gene transfection of individual cells in vitro with plasmonic nanobubbles.

PubMed

Lukianova-Hleb, Ekaterina Y; Samaniego, Adam P; Wen, Jianguo; Metelitsa, Leonid S; Chang, Chung-Che; Lapotko, Dmitri O

2011-06-10

Gene delivery and transfection of eukaryotic cells are widely used for research and for developing gene cell therapy. However, the existing methods lack selectivity, efficacy and safety when heterogeneous cell systems must be treated. We report a new method that employs plasmonic nanobubbles (PNBs) for delivery and transfection. A PNB is a novel, tunable cellular agent with a dual mechanical and optical action due to the formation of the vapor nanobubble around a transiently heated gold nanoparticle upon its exposure to a laser pulse. PNBs enabled the mechanical injection of the extracellular cDNA plasmid into the cytoplasm of individual target living cells, cultured leukemia cells and human CD34+ CD117+ stem cells and expression of a green fluorescent protein (GFP) in those cells. PNB generation and lifetime correlated with the expression of green fluorescent protein in PNB-treated cells. Optical scattering by PNBs additionally provided the detection of the target cells and the guidance of cDNA injection at single cell level. In both cell models PNBs demonstrated a gene transfection effect in a single pulse treatment with high selectivity, efficacy and safety. Thus, PNBs provided targeted gene delivery at the single cell level in a single pulse procedure that can be used for safe and effective gene therapy. Copyright © 2011 Elsevier B.V. All rights reserved.

A nonviral DNA delivery system based on surface modified silica-nanoparticles can efficiently transfect cells in vitro.

PubMed

Kneuer, C; Sameti, M; Bakowsky, U; Schiestel, T; Schirra, H; Schmidt, H; Lehr, C M

2000-01-01

Diverse polycationic polymers have been used as nonviral transfection agents. Here we report the ability of colloidal silica particles with covalently attached cationic surface modifications to transfect plasmid DNA in vitro and make an attempt to describe the structure of the resulting transfection complexes. In analogy to the terms lipoplex and polyplex, we propose to describe the nanoparticle-DNA complexes by the term "nanoplex". Three batches, Si10E, Si100E, and Si26H, sized between 10 and 100 nm and with zeta potentials ranging from +7 to +31 mV at pH 7.4 were evaluated. The galactosidase expression plasmid DNA pCMVbeta was immobilized on the particle surface and efficiently transfected Cos-1 cells. The transfection activity was accompanied by very low cytotoxicity, with LD(50) values in the milligrams per milliliter range. The most active batch, Si26H, was produced by modification of commercially available silica particles with N-(6-aminohexyl)-3-aminopropyltrimethoxysilane, yielding spherical nanoparticles with a mean diameter of 26 nm and a zeta potential of +31 mV at pH 7.4. Complexes of Si26H and pCMVbeta plasmid DNA formed at w/w ratios of 10 were most effective in promoting transfection of Cos-1 cells in the absence of serum. At this ratio, >90% of the DNA was associated with the particles, yielding nanoplexes with a net negative surface charge. When the transfection medium was supplemented with 10% serum, maximum gene expression was observed at a w/w ratio of 30, at which the resulting particle-DNA complexes possessed a positive surface charge. Transfection was strongly increased in the presence of 100 microM chloroquine in the incubation medium and reached approximately 30% of the efficiency of a 60 kDa polyethylenimine. In contrast to polyethylenimine, no toxicity was observed at the concentrations required. Atomic force microscopy of Si26H-DNA complexes revealed a spaghetti-meatball-like structure. The surface of complexes prepared at a w/w ratio of

Immobilization of gold nanoparticles on cell culture surfaces for safe and enhanced gold nanoparticle-mediated laser transfection.

PubMed

Kalies, Stefan; Heinemann, Dag; Schomaker, Markus; Gentemann, Lara; Meyer, Heiko; Ripken, Tammo

2014-01-01

In comparison to standard transfection methods, gold nanoparticle-mediated laser transfection has proven to be a versatile alternative. This is based on its minor influence on cell viability and its high efficiency, especially for the delivery of small molecules like small interfering RNA. However, in order to transfer it to routine usage, a safety aspect is of major concern: The avoidance of nanoparticle uptake by the cells is desired. The immobilization of the gold nanoparticles on cell culture surfaces can address this issue. In this study, we achieved this by silanization of the appropriate surfaces and the binding of gold nanoparticles to them. Comparable perforation efficiencies to the previous approaches of gold nanoparticle-mediated laser transfection with free gold nanoparticles are demonstrated. The uptake of the immobilized particles by the cells is unlikely. Consequently, these investigations offer the possibility of bringing gold nanoparticle-mediated laser transfection closer to routine usage.

Interfacial engineering of pyridinium gemini surfactants for the generation of synthetic transfection systems.

PubMed

Sharma, Vishnu D; Aifuwa, Eronmwon O; Heiney, Paul A; Ilies, Marc A

2013-09-01

Pyridinium gemini surfactants possess a soft charge, a high charge/mass ratio and a high molecular flexibility - all key parameters that recommend their use in synthetic gene delivery systems with in vitro and in vivo efficiency. In present study we generated a DNA delivery system through interfacial engineering of pyridinium gemini surfactants at the level of linker, hydrophobic chains and counterions. The self-assembling of the pyridinium amphiphiles and the physicochemical properties of the resultant supra-molecular assemblies were studied in bulk and in solution through a combination of techniques that included DSC, X-ray diffraction, polarized microscopy, CMC, dynamic light scattering and zeta potential measurements. We assessed the impact of different structural elements and formulation parameters of these pyridinium amphiphiles on their DNA compaction properties, transfection efficiency, cytotoxicity, in a complete structure-activity relationship study. This interfacial engineering process generated transfection systems with reduced cytotoxicity and high transfection efficiency in media containing elevated levels of serum that mimic the in vivo conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Multimodal Fluorescence and Bioluminescence Imaging Reveals Transfection Potential of Intratracheally Administered Polyplexes for Breast Cancer Lung Metastases.

PubMed

Geyer, Antonia; Taschauer, Alexander; Alioglu, Fatih; Anton, Martina; Maier, Julia; Drothler, Elisabeth; Simlinger, Manuela; Yavuz, Sümeyye; Sami, Haider; Ogris, Manfred

2017-12-01

Local delivery of anticancer agents or gene therapeutics to lung tumors can circumvent side effects or accumulation in non-target organs, but accessibility via the alveolar side of the blood-air barrier remains challenging. Polyplexes based on plasmid and linear polyethylenimine (LPEI) transfect healthy lung tissue when applied intravenously (i.v.) in the mouse, but direct delivery into the lungs results in low transfection of lung tissue. Nevertheless, LPEI could offer the potential to transfect lung tumors selectively, if accessible from the alveolar side. This study combined near infrared fluorescent protein 720 (iRFP720) and firefly luciferase as reporter genes for detection of tumor lesions and transfection efficiency of LPEI polyplexes, after intratracheal microspraying in mice bearing 4T1 triple negative breast cancer lung metastases. Simultaneous flow cytometric analysis of iRFP720 and enhanced green fluorescent protein expression in vitro demonstrated the potential to combine these reporter genes within transfection studies. Polyplex biophysics was characterized by single nanoparticle tracking analysis (NTA) to monitor physical integrity after microspraying in vitro. 4T1 cells were transduced with iRFP720-encoding lentivirus and evaluated by flow cytometry for stable iRFP720 expression. Growth of 4T1-iRFP720 cells was monitored in Balb/c mice by tomographic near infrared imaging, tissue and tumor morphology by computed tomography and magnetic resonance imaging. In 4T1-iRFP720 tumor-bearing mice, intratracheal administration of luciferase-encoding plasmid DNA by LPEI polyplexes resulted in successful tumor transfection, as revealed by bioluminescence imaging.

Flow-through electroporation based on constant voltage for large-volume transfection of cells.

PubMed

Geng, Tao; Zhan, Yihong; Wang, Hsiang-Yu; Witting, Scott R; Cornetta, Kenneth G; Lu, Chang

2010-05-21

Genetic modification of cells is a critical step involved in many cell therapy and gene therapy protocols. In these applications, cell samples of large volume (10(8)-10(9)cells) are often processed for transfection. This poses new challenges for current transfection methods and practices. Here we present a novel flow-through electroporation method for delivery of genes into cells at high flow rates (up to approximately 20 mL/min) based on disposable microfluidic chips, a syringe pump, and a low-cost direct current (DC) power supply that provides a constant voltage. By eliminating pulse generators used in conventional electroporation, we dramatically lowered the cost of the apparatus and improved the stability and consistency of the electroporation field for long-time operation. We tested the delivery of pEFGP-C1 plasmids encoding enhanced green fluorescent protein into Chinese hamster ovary (CHO-K1) cells in the devices of various dimensions and geometries. Cells were mixed with plasmids and then flowed through a fluidic channel continuously while a constant voltage was established across the device. Together with the applied voltage, the geometry and dimensions of the fluidic channel determined the electrical parameters of the electroporation. With the optimal design, approximately 75% of the viable CHO cells were transfected after the procedure. We also generalize the guidelines for scaling up these flow-through electroporation devices. We envision that this technique will serve as a generic and low-cost tool for a variety of clinical applications requiring large volume of transfected cells. Copyright 2010 Elsevier B.V. All rights reserved.

Direct and sustained intracellular delivery of exogenous molecules using acoustic-transfection with high frequency ultrasound

PubMed Central

Yoon, Sangpil; Kim, Min Gon; Chiu, Chi Tat; Hwang, Jae Youn; Kim, Hyung Ham; Wang, Yingxiao; Shung, K. Kirk

2016-01-01

Controlling cell functions for research and therapeutic purposes may open new strategies for the treatment of many diseases. An efficient and safe introduction of membrane impermeable molecules into target cells will provide versatile means to modulate cell fate. We introduce a new transfection technique that utilizes high frequency ultrasound without any contrast agents such as microbubbles, bringing a single-cell level targeting and size-dependent intracellular delivery of macromolecules. The transfection apparatus consists of an ultrasonic transducer with the center frequency of over 150 MHz and an epi-fluorescence microscope, entitled acoustic-transfection system. Acoustic pulses, emitted from an ultrasonic transducer, perturb the lipid bilayer of the cell membrane of a targeted single-cell to induce intracellular delivery of exogenous molecules. Simultaneous live cell imaging using HeLa cells to investigate the intracellular concentration of Ca2+ and propidium iodide (PI) and the delivery of 3 kDa dextran labeled with Alexa 488 were demonstrated. Cytosolic delivery of 3 kDa dextran induced via acoustic-transfection was manifested by diffused fluorescence throughout whole cells. Short-term (6 hr) cell viability test and long-term (40 hr) cell tracking confirmed that the proposed approach has low cell cytotoxicity. PMID:26843283

Direct and sustained intracellular delivery of exogenous molecules using acoustic-transfection with high frequency ultrasound

NASA Astrophysics Data System (ADS)

Yoon, Sangpil; Kim, Min Gon; Chiu, Chi Tat; Hwang, Jae Youn; Kim, Hyung Ham; Wang, Yingxiao; Shung, K. Kirk

2016-02-01

Controlling cell functions for research and therapeutic purposes may open new strategies for the treatment of many diseases. An efficient and safe introduction of membrane impermeable molecules into target cells will provide versatile means to modulate cell fate. We introduce a new transfection technique that utilizes high frequency ultrasound without any contrast agents such as microbubbles, bringing a single-cell level targeting and size-dependent intracellular delivery of macromolecules. The transfection apparatus consists of an ultrasonic transducer with the center frequency of over 150 MHz and an epi-fluorescence microscope, entitled acoustic-transfection system. Acoustic pulses, emitted from an ultrasonic transducer, perturb the lipid bilayer of the cell membrane of a targeted single-cell to induce intracellular delivery of exogenous molecules. Simultaneous live cell imaging using HeLa cells to investigate the intracellular concentration of Ca2+ and propidium iodide (PI) and the delivery of 3 kDa dextran labeled with Alexa 488 were demonstrated. Cytosolic delivery of 3 kDa dextran induced via acoustic-transfection was manifested by diffused fluorescence throughout whole cells. Short-term (6 hr) cell viability test and long-term (40 hr) cell tracking confirmed that the proposed approach has low cell cytotoxicity.

Co-self-assembly of cationic microparticles to deliver pEGFP-ZNF580 for promoting the transfection and migration of endothelial cells

PubMed Central

Feng, Yakai; Guo, Mengyang; Liu, Wen; Hao, Xuefang; Lu, Wei; Ren, Xiangkui; Shi, Changcan; Zhang, Wencheng

2017-01-01

The gene transfection efficiency of polyethylenimine (PEI) varies with its molecular weight. Usually, high molecular weight of PEI means high gene transfection, as well as high cytotoxicity in gene delivery in vivo. In order to enhance the transfection efficiency and reduce the cytotoxicity of PEI-based gene carriers, a novel cationic gene carrier was developed by co-self-assembly of cationic copolymers. First, a star-shaped copolymer poly(3(S)-methyl-morpholine-2,5-dione-co-lactide) (P(MMD-co-LA)) was synthesized using D-sorbitol as an initiator, and the cationic copolymer (P(MMD-co-LA)-g-PEI) was obtained after grafting low-molecular weight PEI. Then, by co-self-assembly of this cationic copolymer and a diblock copolymer methoxy-poly(ethylene glycol) (mPEG)-b-P(MMD-co-LA), microparticles (MPs) were formed. The core of MPs consisted of a biodegradable block of P(MMD-co-LA), and the shell was formed by mPEG and PEI blocks. Finally, after condensation of pEGFP-ZNF580 by these MPs, the plasmids were protected from enzymatic hydrolysis effectively. The result indicated that pEGFP-ZNF580-loaded MP complexes were suitable for cellular uptake and gene transfection. When the mass ratio of mPEG-b-P(MMD-co-LA) to P(MMD-co-LA)-g-PEI reached 3/1, the cytotoxicity of the complexes was very low at low concentration (20 μg mL−1). Additionally, pEGFP-ZNF580 could be transported into endothelial cells (ECs) effectively via the complexes of MPs/pEGFP-ZNF580. Wound-healing assay showed that the transfected ECs recovered in 24 h. Cationic MPs designed in the present study could be used as an applicable gene carrier for the endothelialization of artificial blood vessels. PMID:28053529

Molecular genetic transfection of the coccidian parasite Sarcocystis neurona.

PubMed

Gaji, Rajshekhar Y; Zhang, Deqing; Breathnach, Cormac C; Vaishnava, Shipra; Striepen, Boris; Howe, Daniel K

2006-11-01

Sarcocystis neurona is an apicomplexan parasite that is the major cause of equine protozoal myeloencephalitis (EPM). The biology of this pathogen remains poorly understood in part due to unavailability of molecular genetic tools. Hence, with an objective to develop DNA transfection capabilities for S. neurona, the 5' flanking region of the SnSAG1 gene was isolated from a genomic library and used to construct expression plasmids. In transient assays, the reporter molecules beta-galactosidase (beta-gal) and yellow fluorescent protein (YFP) could be detected in electroporated S. neurona, thereby confirming the feasibility of transgene expression in this organism. Stable transformation of S. neurona was achieved using a mutant dihydrofolate reductase thymidylate synthase (DHFR-TS) gene of Toxoplasma gondii that confers resistance to pyrimethamine. This selection system was used to create transgenic S. neurona that stably express beta-gal and YFP. As shown in this study, these transgenic clones can be useful for analyzing growth rate of parasites in vitro and for assessing drug sensitivities. More importantly, the DNA transfection methods described herein should greatly facilitate studies examining intracellular parasitism by this important coccidian pathogen.

Ultrasound microbubble-mediated transfection of NF-κB decoy oligodeoxynucleotide into gingival tissues inhibits periodontitis in rats in vivo

PubMed Central

Yamaguchi, Hiroyuki; Hosomichi, Jun; Suzuki, Jun-ichi; Hatano, Kasumi; Usumi-Fujita, Risa; Shimizu, Yasuhiro; Kaneko, Sawa; Ono, Takashi

2017-01-01

Periodontitis is a chronic infectious disease for which the fundamental treatment is to reduce the load of subgingival pathogenic bacteria by debridement. However, previous investigators attempted to implement a nuclear factor kappa B (NF-κB) decoy oligodeoxynucleotide (ODN) as a suppressor of periodontitis progression. Although we recently reported the effectiveness of the ultrasound-microbubble method as a tool for transfecting the NF-κB decoy ODN into healthy rodent gingival tissue, this technique has not yet been applied to the pathological gingiva of periodontitis animal models. Therefore, the aim of this study was to investigate the effectiveness of the technique in transfecting the NF-κB decoy ODN into rats with ligature-induced periodontitis. Micro computed tomography (micro-CT) analysis demonstrated a significant reduction in alveolar bone loss following treatment with the NF-κB decoy ODN in the experimental group. RT-PCR showed that NF-κB decoy ODN treatment resulted in significantly reduced expression of inflammatory cytokine transcripts within rat gingival tissues. Thus, we established a transcutaneous transfection model of NF-κB decoy ODN treatment of periodontal tissues using the ultrasound-microbubble technique. Our findings suggest that the NF-κB decoy ODN could be used as a significant suppressor of gingival inflammation and periodontal disease progression. PMID:29091721

Single-Factor SOX2 Mediates Direct Neural Reprogramming of Human Mesenchymal Stem Cells via Transfection of In Vitro Transcribed mRNA.

PubMed

Kim, Bo-Eun; Choi, Soon Won; Shin, Ji-Hee; Kim, Jae-Jun; Kang, Insung; Lee, Byung-Chul; Lee, Jin Young; Kook, Myoung Geun; Kang, Kyung-Sun

2018-01-01

Neural stem cells (NSCs) are a prominent cell source for understanding neural pathogenesis and for developing therapeutic applications to treat neurodegenerative disease because of their regenerative capacity and multipotency. Recently, a variety of cellular reprogramming technologies have been developed to facilitate in vitro generation of NSCs, called induced NSCs (iNSCs). However, the genetic safety aspects of established virus-based reprogramming methods have been considered, and non-integrating reprogramming methods have been developed. Reprogramming with in vitro transcribed (IVT) mRNA is one of the genetically safe reprogramming methods because exogenous mRNA temporally exists in the cell and is not integrated into the chromosome. Here, we successfully generated expandable iNSCs from human umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) via transfection with IVT mRNA encoding SOX2 (SOX2 mRNA) with properly optimized conditions. We confirmed that generated human UCB-MSC-derived iNSCs (UM-iNSCs) possess characteristics of NSCs, including multipotency and self-renewal capacity. Additionally, we transfected human dermal fibroblasts (HDFs) with SOX2 mRNA. Compared with human embryonic stem cell-derived NSCs, HDFs transfected with SOX2 mRNA exhibited neural reprogramming with similar morphologies and NSC-enriched mRNA levels, but they showed limited proliferation ability. Our results demonstrated that human UCB-MSCs can be used for direct reprogramming into NSCs through transfection with IVT mRNA encoding a single factor, which provides an integration-free reprogramming tool for future therapeutic application.

Tumor transfection after systemic injection of DNA lipid nanocapsules.

PubMed

Morille, Marie; Passirani, Catherine; Dufort, Sandrine; Bastiat, Guillaume; Pitard, Bruno; Coll, Jean-Luc; Benoit, Jean-Pierre

2011-03-01

With the goal of generating an efficient vector for systemic gene delivery, a new kind of nanocarrier consisting of lipid nanocapsules encapsulating DOTAP/DOPE lipoplexes (DNA LNCs) was pegylated by the post-insertion of amphiphilic and flexible polymers. The aim of this surface modification was to create a long-circulating vector, able to circulate in the blood stream and efficient in transfecting tumoral cells after passive targeting by enhanced permeability and retention effect (EPR effect). PEG conformation, electrostatic features, and hydrophylicity are known to be important factors able to influence the pharmacokinetic behaviour of vectors. In this context, the surface structure characteristics of the newly pegylated DNA LNCs were studied by measuring electrophoretic mobility as a function of ionic strength in order to establish a correlation between surface properties and in vivo performance of the vector. Finally, thanks to this PEGylation, gene expression was measured up to 84-fold higher in tumor compared to other tested organs after intravenous injection. The present results indicate that PEGylated DNA LNCs are promising carriers for an efficient cancer gene therapy. Copyright © 2010 Elsevier Ltd. All rights reserved.

MicroRNA-122 mimic transfection contributes to apoptosis in HepG2 cells.

PubMed

Huang, Hongyan; Zhu, Yueyong; Li, Shaoyang

2015-11-01

There is currently a requirement for effective treatment strategies for human hepatocellular carcinoma (HCC), a leading cause of cancer‑associated mortality. MicroRNA-122 (miR-122), a repressor of the endogenous apoptosis regulator Bcl‑w, is frequently downregulated in HCC. Thus, it is hypothesized that the activation of miR‑122 may induce selective hepatocellular apoptosis via caspase activation in a model of HCC. In the present study, an miR‑122 mimic transfection was performed in HepG2 cells, and used to investigate the role and therapeutic potential of miR‑122 in the regulation of HCC‑derived cell lines. The apoptotic rates of HepG2 cells were significantly increased following miR‑122 mimic transfection. Reverse transcription‑polymerase chain reaction analysis revealed that Bcl‑w mRNA was significantly reduced, while the mRNA levels of caspase‑9 and caspase‑3 were markedly increased. The immunocytochemistry results supported the mRNA trends. Collectively, the present results suggest that endogenous miR‑122 contributes to HepG2 apoptosis and that transfection of mimic miR‑122 normalizes apoptotic levels in a model of HCC.

Characterization of insulin-producing cells derived from PDX-1-transfected neural stem cells.

PubMed

Wang, Hailan; Jiang, Zesheng; Li, Aihui; Gao, Yi

2012-12-01

Islet cell transplantation is a promising treatment strategy for type-1 diabetes. However, functional islet cells are hard to obtain for transplantation and are in short supply. Directing the differentiation of stem cells into insulin‑producing cells, which serve as islet cells, would overcome this shortage. Bone marrow contains hematopoietic stem cells and mesenchymal stem cells. The present study used bone marrow cells isolated from rats and neural stem cells (NSCs) that were derived from bone marrow cells in culture. Strong nestin staining was detected in NSCs, but not in bone marrow stromal cells (BMSCs). In vitro transfection of the pancreatic duodenal homeobox-1 (PDX-1) gene into NSCs generated insulin‑producing cells. Reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) analysis confirmed that PDX-1-transfected NSCs expressed insulin mRNA and released insulin protein. However, insulin release from PDX-1-transfected NSCs did not respond to the challenge of glucose and glucagon-like peptide-1. These results support the use of bone marrow-derived NSCs as a renewable source of insulin-producing cells for autologous transplantation to treat type-1 diabetes.

GnRH receptor activation competes at a low level with growth signaling in stably transfected human breast cell lines

PubMed Central

2011-01-01

RH-R immunostaining, with higher levels of expression found in triple-negative and grade 3 cancers. However, functional cell surface receptors are rare in cultured cells. Intense GnRH-R signaling in transfected breast cancer cells did not markedly inhibit growth, in contrast to transfected HEK 293 cells indicating the importance of intracellular context. GnRH-R signaling could not counteract IGF-I receptor-tyrosine kinase addiction in MCF-7 cells. These results suggest that combinatorial strategies with growth factor inhibitors will be needed to enhance GnRH anti-proliferative effects in breast cancer PMID:22051164

Ultrasound-microbubble-mediated intercellular adhesion molecule-1 small interfering ribonucleic acid transfection attenuates neointimal formation after arterial injury in mice.

PubMed

Suzuki, Jun-ichi; Ogawa, Masahito; Takayama, Kiyoshi; Taniyama, Yoshiaki; Morishita, Ryuichi; Hirata, Yasunobu; Nagai, Ryozo; Isobe, Mitsuaki

2010-03-02

The purpose of this study was to investigate the efficiency of small interfering ribonucleic acid (siRNA) in murine arteries. We transfected it using a nonviral ultrasound-microbubble-mediated in vivo gene delivery system. siRNA is an effective methodology to suppress gene function. The siRNA can be synthesized easily; however, a major obstacle in the use of siRNA as therapeutics is the difficulty involved in effective in vivo delivery. To investigate the efficiency of nonviral ultrasound-microbubble-mediated in vivo siRNA delivery, we used a fluorescein-labeled siRNA, green fluorescent protein (GFP) siRNA, and intercellular adhesion molecule (ICAM)-1 siRNA in murine arteries. Murine femoral arteries were injured using flexible wires to establish arterial injury. The fluorescein-labeled siRNA and GFP siRNA showed that this nonviral approach could deliver siRNA into target arteries effectively without any tissue damage and systemic adverse effects. ICAM-1 siRNA transfection into murine injured arteries significantly suppressed the development of neointimal formation in comparison to those in the control group. Immunohistochemistry revealed that accumulation of T cells and adhesion molecule positive cells was observed in nontreated injured arteries, whereas siRNA suppressed accumulation. The nonviral ultrasound-microbubble delivery of siRNA ensures effective transfection into target arteries. ICAM-1 siRNA has the potential to suppress arterial neointimal formation. Transfection of siRNA can be beneficial for the clinical treatment of cardiovascular and other inflammatory diseases. Copyright 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Efficient generation of integration-free human induced pluripotent stem cells from keratinocytes by simple transfection of episomal vectors.

PubMed

Piao, Yulan; Hung, Sandy Shen-Chi; Lim, Shiang Y; Wong, Raymond Ching-Bong; Ko, Minoru S H

2014-07-01

Keratinocytes represent an easily accessible cell source for derivation of human induced pluripotent stem (hiPS) cells, reportedly achieving higher reprogramming efficiency than fibroblasts. However, most studies utilized a retroviral or lentiviral method for reprogramming of keratinocytes, which introduces undesirable transgene integrations into the host genome. Moreover, current protocols of generating integration-free hiPS cells from keratinocytes are mostly inefficient. In this paper, we describe a more efficient, simple-to-use, and cost-effective method for generating integration-free hiPS cells from keratinocytes. Our improved method using lipid-mediated transfection achieved a reprogramming efficiency of ∼0.14% on average. Keratinocyte-derived hiPS cells showed no integration of episomal vectors, expressed stem cell-specific markers and possessed potentials to differentiate into all three germ layers by in vitro embryoid body formation as well as in vivo teratoma formation. To our knowledge, this represents the most efficient method to generate integration-free hiPS cells from keratinocytes. ©AlphaMed Press.

Linear Lepidopteran ambidensovirus 1 sequences drive random integration of a reporter gene in transfected Spodoptera frugiperda cells.

PubMed

Rizk, Francine; Laverdure, Sylvain; d'Alençon, Emmanuelle; Bossin, Hervé; Dupressoir, Thierry

2018-01-01

The Lepidopteran ambidensovirus 1 isolated from Junonia coenia (hereafter JcDV) is an invertebrate parvovirus considered as a viral transduction vector as well as a potential tool for the biological control of insect pests. Previous works showed that JcDV-based circular plasmids experimentally integrate into insect cells genomic DNA. In order to approach the natural conditions of infection and possible integration, we generated linear JcDV- gfp based molecules which were transfected into non permissive Spodoptera frugiperda ( Sf9 ) cultured cells. Cells were monitored for the expression of green fluorescent protein (GFP) and DNA was analyzed for integration of transduced viral sequences. Non-structural protein modulation of the VP-gene cassette promoter activity was additionally assayed. We show that linear JcDV-derived molecules are capable of long term genomic integration and sustained transgene expression in Sf9 cells. As expected, only the deletion of both inverted terminal repeats (ITR) or the polyadenylation signals of NS and VP genes dramatically impairs the global transduction/expression efficiency. However, all the integrated viral sequences we characterized appear "scrambled" whatever the viral content of the transfected vector. Despite a strong GFP expression, we were unable to recover any full sequence of the original constructs and found rearranged viral and non-viral sequences as well. Cellular flanking sequences were identified as non-coding ones. On the other hand, the kinetics of GFP expression over time led us to investigate the apparent down-regulation by non-structural proteins of the VP-gene cassette promoter. Altogether, our results show that JcDV-derived sequences included in linear DNA molecules are able to drive efficiently the integration and expression of a foreign gene into the genome of insect cells, whatever their composition, provided that at least one ITR is present. However, the transfected sequences were extensively rearranged with

Generation of CTL responses against pancreatic cancer in vitro using dendritic cells co-transfected with MUC4 and survivin RNA.

PubMed

Chen, Jiang; Guo, Xiao-Zhong; Li, Hong-Yu; Liu, Xu; Ren, Li-Nan; Wang, Di; Zhao, Jia-Jun

2013-09-23

Pancreatic cancer (PC) is one of the most devastating human malignancies without effective therapies. Tumor vaccine based on RNA-transfected dendritic cells (DCs) has emerged as an alternative therapeutic approach for a variety of human cancers including advanced PC. In the present study we compared the cytotoxic T lymphocyte (CTL) responses against PC cells in vitro, which were induced by DCs co-transfected with two mRNAs of tumor associated-antigens (TAA) MUC4 and survivin, versus DCs transfected with a single mRNA encoding either MUC4 or survivin. DCs co-transfected with two TAA mRNAs were found to induce stronger CTL responses against PC target cells in vitro, compared with the DCs transfected with a single mRNA. Moreover, the antigen-specific CTL responses were MHC class I-restricted. These results provide an experimental foundation for further clinical investigations of DC vaccines encoding multiple TAA epitopes for metastatic PC. Copyright © 2013 Elsevier Ltd. All rights reserved.

Nanothermite-Based Microsystem for Drug Delivery and Cell Transfection

DTIC Science & Technology

2008-12-01

micropyrotechnic-based system in which a nanothermite energy source is coupled to a biological target for gene transfer and drug delivery ... delivery of particulate vaccines and drugs to human skin with a practical, hand-held shock tube-based system . Shock Waves, 12, 23-30. Kodama, T., M...1 NANOTHERMITE-BASED MICROSYSTEM FOR DRUG DELIVERY AND CELL TRANSFECTION S. Apperson, R. Thiruvengadathan, A. Bezmelnitsyn, K. Gangopadhyay, S

Polyamidoamine dendrimer-functionalized carbon nanotubes-mediated GFP gene transfection for HeLa cells: effects of different types of carbon nanotubes.

PubMed

Yang, Keqin; Qin, Weiling; Tang, Hao; Tan, Liang; Xie, Qingji; Ma, Ming; Zhang, Youyu; Yao, Shouzhuo

2011-11-01

Three types of functionalized carbon nanotubes (f-CNTs), polyamidoamine (PAMAM) dendrimer-functionalized single and multi-walled CNTs (MWCNT-PAMAM-1, MWCNT-PAMAM-2, and SWCNT-PAMAM-3), were prepared by covalent linkage approach. The micro-morphologies of the three f-CNTs and the interaction of MWCNT-PAMAM-2 with HeLa cells were characterized by transmission electron microscopy (TEM). The free amine groups on the surface of the three types of CNTs-PAMAM hybrids were quantitatively analyzed. Their cytotoxicity and transfection efficiency of plasmid DNA of enhanced green fluorescent protein (pEGFP-N1) to HeLa cells were investigated in detail. The results suggest that although all three types of CNTs-PAMAM hybrids can deliver pEGFP-N1 into HeLa cells and the exogenous GFP gene has been successfully expressed, MWCNT-PAMAM-2 with shorter length and larger amount of free amine groups on its surface possesses higher transfection efficiency (6.79%), being about 3.0 and 1.7 times as large as those of MWCNT-PAMAM-1 (2.24%) and SWCNT-PAMAM-3 (4.08%), respectively; their cytotoxicity to HeLa cells decrease following the sequence of SWCNT-PAMAM-3 > MWCNT-PAMAM-2 > MWCNT-PAMAM-1. These results may be useful for understanding the effects of the chemical/physical properties of f-CNTs on their gene transfection efficiency and cytotoxicity, allowing for construction of promising CNT-based intracellular delivery vectors for gene therapy. Copyright © 2011 Wiley Periodicals, Inc.

Targeted transfection increases siRNA uptake and gene silencing of primary endothelial cells in vitro--a quantitative study.

PubMed

Asgeirsdóttir, Sigridur A; Talman, Eduard G; de Graaf, Inge A; Kamps, Jan A A M; Satchell, Simon C; Mathieson, Peter W; Ruiters, Marcel H J; Molema, Grietje

2010-01-25

Applications of small-interfering RNA (siRNA) call for specific and efficient delivery of siRNA into particular cell types. We developed a novel, non-viral targeting system to deliver siRNA specifically into inflammation-activated endothelial cells. This was achieved by conjugating the cationic amphiphilic lipid SAINT to antibodies recognizing the inflammatory cell adhesion molecule E-selectin. These anti-E-selectin-SAINT lipoplexes (SAINTarg) maintained antigen recognition capacity of the parental antibody in vitro, and ex vivo in human kidney tissue slices subjected to inflammatory conditions. Regular SAINT mediated transfection resulted in efficient gene silencing in human microvascular endothelial cells (HMEC-1) and conditionally immortalized glomerular endothelial cells (ciGEnC). However, primary human umbilical vein endothelial cells (HUVEC) transfected poorly, a phenomenon that we could quantitatively correlate with a cell-type specific capacity to facilitate siRNA uptake. Importantly, SAINTarg increased siRNA uptake and transfection specificity for activated endothelial cells. Transfection with SAINTarg delivered significantly more siRNA into activated HUVEC, compared to transfection with non-targeted SAINT. The enhanced uptake of siRNA was corroborated by improved silencing of both gene- and protein expression of VE-cadherin in activated HUVEC, indicating that SAINTarg delivered functionally active siRNA into endothelial cells. The obtained results demonstrate a successful design of a small nucleotide carrier system with improved and specific siRNA delivery into otherwise difficult-to-transfect primary endothelial cells, which in addition reduced considerably the amount of siRNA needed for gene silencing. Copyright 2009 Elsevier B.V. All rights reserved.

Transfection of the IHH gene into rabbit BMSCs in a simulated microgravity environment promotes chondrogenic differentiation and inhibits cartilage aging.

PubMed

Liu, Peng-Cheng; Liu, Kuan; Liu, Jun-Feng; Xia, Kuo; Chen, Li-Yang; Wu, Xing

2016-09-27

The effect of overexpressing the Indian hedgehog (IHH) gene on the chondrogenic differentiation of rabbit bone marrow-derived mesenchymal stem cells (BMSCs) was investigated in a simulated microgravity environment. An adenovirus plasmid encoding the rabbit IHH gene was constructed in vitro and transfected into rabbit BMSCs. Two large groups were used: conventional cell culture and induction model group and simulated microgravity environment group. Each large group was further divided into blank control group, GFP transfection group, and IHH transfection group. During differentiation induction, the expression levels of cartilage-related and cartilage hypertrophy-related genes and proteins in each group were determined. In the conventional model, the IHH transfection group expressed high levels of cartilage-related factors (Coll2 and ANCN) at the early stage of differentiation induction and expressed high levels of cartilage hypertrophy-related factors (Coll10, annexin 5, and ALP) at the late stage. Under the simulated microgravity environment, the IHH transfection group expressed high levels of cartilage-related factors and low levels of cartilage hypertrophy-related factors at all stages of differentiation induction. Under the simulated microgravity environment, transfection of the IHH gene into BMSCs effectively promoted the generation of cartilage and inhibited cartilage aging and osteogenesis. Therefore, this technique is suitable for cartilage tissue engineering.

A versatile transfection assay system to evaluate the biological effects of diverse industrial chemicals.

PubMed

Koizumi, Shinji; Ohno, Shotaro; Otsuka, Fuminori

2012-01-01

Gene expression processes are now recognized as important targets of the toxic effects exerted by industrial chemicals. The transient transfection assay is a powerful tool to evaluate such effects. Thus, we developed a versatile assay system by constructing a basic reporter plasmid in which the regulatory DNA sequence to be studied can easily be substituted. To verify the performance of this system, reporter plasmids carrying any of the three distinct regulatory sequences, estrogen responsive element (ERE), glucocorticoid responsive element (GRE) and xenobiotic responsive element (XRE) were constructed. After transfection of human cells, these plasmids successfully expressed the relevant reporter genes in response to specific inducers, β-estradiol, dexamethasone and 3-methylcholanthrene, respectively. Several industrial chemicals were assayed using these reporter plasmids, and the ability of p-dimethylaminoazobenzene to elevate GRE- and XRE-mediated transcription was detected. α-Naphthylamine and o-tolidine were also observed to increase the XRE-mediated response. The transfection assay system established here will be useful to evaluate the effects of a wide variety of industrial chemicals.

Important role of phosphoramido linkage in imidazole-based dioleyl helper lipids for liposome stability and primary cell transfection.

PubMed

Mével, Mathieu; Haudebourg, Thomas; Colombani, Thibault; Peuziat, Pauline; Dallet, Laurence; Chatin, Benoît; Lambert, Olivier; Berchel, Mathieu; Montier, Tristan; Jaffrès, Paul-Alain; Lehn, Pierre; Pitard, Bruno

2016-01-01

To optimize synthetic gene delivery systems, there is a need to develop more efficient lipid formulations. Most cationic lipid formulations contain 'helper' neutral lipids because of their ability to increase DNA delivery, in particular by improving endosomal escape of DNA molecules via the pH-buffering effect of protonatable groups and/or fusion with the lipid bilayer of endosomes. We evaluated the influence of the linker structure between the two oleyl chains in the helper lipid on transfection efficiency in cell lines, as well as in primary cells (hepatocytes/cardiomyocytes). We reported the synthesis of two new pH-buffering imidazole helper lipids characterized by a polar headgroup containing one (compound 6) or two (compound 5) imidazole groups and two oleyl chains linked by an amide group. We studied their association with the aminoglycoside lipidic derivative dioleylsuccinylparomomycin (DOSP), which contains two oleyl chains linked to the aminoglycoside polar headgroup via an amide function. We compared the morphology and transfection properties of such binary liposomes of DOSP/5 and DOSP/6 with those of liposomes combining DOSP with another imidazole-based dioleyl helper lipid (MM27) in which a phosphoramido group acts as a linker between the two oleyl chains and imidazole function. The phosphoramido linker in the helper lipid induces a major difference in terms of morphology and resistance to decomplexation at physical pH for DOSP/helper lipid complexes. This hybrid dioleyl linker composition of DOSP/MM27 led to higher transfection efficiency in cell lines and in primary cells compared to complexes with homogeneous dioleyl linker. Copyright © 2015 John Wiley & Sons, Ltd.

Tumor site-specific silencing of NF-κB p65 by targeted hollow gold nanospheres-mediated photothermal transfection

PubMed Central

Lu, Wei; Zhang, Guodong; Zhang, Rui; Flores, Leo G; Huang, Qian; Gelovani, Juri G; Li, Chun

2010-01-01

Nuclear factor-κB (NF-κB) transcription factor is a critical regulator of the expression of genes involved in tumor formation and progression. Successful RNA interference (RNAi) therapeutics targeting NF-κB is challenged by siRNA delivery systems, which can render targeted in vivo delivery, efficient endo-lysosomal escape and dynamic control over activation of RNAi. Here, we report near-infrared light-inducible NF-κB down-regulation through folate receptor-targeted hollow gold nanospheres carrying siRNA recognizing NF-κB p65 subunit. Using micro-positron emission tomography/computed tomography imaging, the targeted nanoconstructs exhibited significantly higher tumor uptake in nude mice-bearing HeLa cervical cancer xenografts than non-targeted nanoparticles following intravenous administration. Mediated by hollow gold nanospheres, controllable cytoplasmic delivery of siRNA was obtained upon near-infrared light irradiation through photothermal effect. Efficient down-regulation of NF-κB p65 was achieved only in tumors irradiated with near-infrared light, but not in non-irradiated tumors grown in the same mice. Liver, spleen, kidney, and lung were not affected by the treatments, in spite of significant uptake of the siRNA nanoparticles in these organs. We term this mode of action “photothermal transfection”. Combined treatments with p65 siRNA photothermal transfection and irinotecan caused substantially enhanced tumor apoptosis and significant tumor growth delay compared with other treatment regimens. Therefore, photothermal transfection of NF-κB p65 siRNA could effectively sensitize the tumor to chemotherapeutic agents. Because NIR light can penetrate skin and be delivered with high spatiotemporal control, therapeutic RNAi may benefit from this novel transfection strategy while avoiding unwanted side effect. PMID:20388791

Biolistic transfection of neuronal cultures using a hand-held gene gun

PubMed Central

O'Brien, John A; Lummis, Sarah C R

2009-01-01

Biolistic transfection is a technique in which subcellular-sized particles coated with DNA are accelerated to high velocity to propel them into cells. This method is applicable to tissues, cells and organelles, and can be used for both in vitro and in vivo transformations; with the right equipment, it is simple, rapid and efficient. Here we provide a detailed protocol for biolistic transfection of plasmids into cultured human embryonic kidney (HEK) 293 cells and organotypic brain slices using a hand-held gene gun. There are three major steps: (i) coating microcarriers with DNA, (ii) transferring the microcarriers into a cartridge to make a ‘bullet’, and (iii) firing the DNA-coated microcarriers into cells using a pulse of helium gas. The method can be readily adapted to other cell types and tissues. The protocol can be completed in 1–2 h. PMID:17406333

Expression of intracellular interferon-alpha confers antiviral properties in transfected bovine fetal fibroblasts and does not affect the full development of SCNT embryos.

PubMed

Yu, Dawei; Zhang, Shoufeng; Du, Weihua; Zhang, Jinxia; Fan, Zongxing; Hao, Haisheng; Liu, Yan; Zhao, Xueming; Qin, Tong; Zhu, Huabin

2014-01-01

Foot-and-mouth disease, one of the most significant diseases of dairy herds, has substantial effects on farm economics, and currently, disease control measures are limited. In this study, we constructed a vector with a human interferon-α (hIFN-α) (without secretory signal sequence) gene cassette containing the immediate early promoter of human cytomegalovirus. Stably transfected bovine fetal fibroblasts were obtained by G418 selection, and hIFN-α transgenic embryos were produced by somatic cell nuclear transfer (SCNT). Forty-six transgenic embryos were transplanted into surrogate cows, and five cows (10.9%) became pregnant. Two male cloned calves were born. Expression of hIFN-α was detected in transfected bovine fetal fibroblasts, transgenic SCNT embryos, and different tissues from a transgenic SCNT calf at two days old. In transfected bovine fetal fibroblasts, expression of intracellular IFN-α induced resistance to vesicular stomatitis virus infection, increased apoptosis, and induced the expression of double-stranded RNA-activated protein kinase gene (PKR) and the 2'-5'-oligoadenylate synthetase gene (2'-5' OAS), which are IFN-inducible genes with antiviral activity. Analysis by qRT-PCR showed that the mRNA expression levels of PKR, 2'-5' OAS, and P53 were significantly increased in wild-type bovine fetal fibroblasts stimulated with extracellular recombinant human IFN-α-2b, showing that intracellular IFN-α induces biological functions similar to extracellular IFN-α. In conclusion, expression of intracellular hIFN-α conferred antiviral properties in transfected bovine fetal fibroblasts and did not significantly affect the full development of SCNT embryos. Thus, IFN-α transgenic technology may provide a revolutionary way to achieve elite breeding of livestock.

Transfection of primary brain capillary endothelial cells for protein synthesis and secretion of recombinant erythropoietin: a strategy to enable protein delivery to the brain.

PubMed

Burkhart, Annette; Andresen, Thomas Lars; Aigner, Achim; Thomsen, Louiza Bohn; Moos, Torben

2017-07-01

Treatment of chronic disorders affecting the central nervous system (CNS) is complicated by the inability of drugs to cross the blood-brain barrier (BBB). Non-viral gene therapy applied to brain capillary endothelial cells (BCECs) denotes a novel approach to overcome the restraints in this passage, as turning BCECs into recombinant protein factories by transfection could result in protein secretion further into the brain. The present study aims to investigate the possibility of transfecting primary rat brain endothelial cells (RBECs) for recombinant protein synthesis and secretion of the neuroprotective protein erythropoietin (EPO). We previously showed that 4% of RBECs with BBB properties can be transfected without disrupting the BBB integrity in vitro, but it can be questioned whether this is sufficient to enable protein secretion at therapeutic levels. The present study examined various transfection vectors, with regard to increasing the transfection efficiency without disrupting the BBB integrity. Lipofectamine 3000™ was the most potent vector compared to polyethylenimine (PEI) and Turbofect. When co-cultured with astrocytes, the genetically modified RBECs secreted recombinant EPO into the cell culture medium both luminally and abluminally, and despite lower levels of EPO reaching the abluminal chamber, the amount of recombinant EPO was sufficient to evolve a biological effect on astrocytes cultured at the abluminal side in terms of upregulated gene expression of brain-derived neurotropic factor (BDNF). In conclusion, non-viral gene therapy to RBECs leads to protein secretion and signifies a method for therapeutic proteins to target cells inside the CNS otherwise omitted due to the BBB.

Chromosomal rearrangements involving telomeric DNA sequences in Balb/3T3 cells transfected with the Ha-ras oncogene.

PubMed

Peitl, Paulo; Mello, Stephano S; Camparoto, Marjori L; Passos, Geraldo A S; Hande, Manoor P; Cardoso, Renato S; Sakamoto-Hojo, Elza T

2002-01-01

Chromosomal instability involving telomeric DNA sequences was studied in mouse Balb/3T3 fibroblasts transfected with a mutated human c-Ha-ras-1 gene (B61 cells) and spontaneously immortalized normal parental cells (A31 cells), using fluorescence in situ hybridization (FISH). FISH analysis with a telomeric probe revealed high frequencies of chromosome alterations involving telomeric regions, mainly stable and unstable Robertsonian fusion-like configurations (RLC) (0.25 and 1.95/cell in A31 and B61 cells, respectively) and chromosome ends lacking telomeric signals in one (LTS') or both chromatids (LTS") (5.9 and 17.5/cell for A31 and B61 cells, respectively). Interstitial telomeric sequences (ITS) were also detected at both non-telomeric sites and in the centromeres of RLC. The frequencies of RLCs with ITS located in the centromeres were 3-fold higher in B61 compared with A31 cells. We demonstrated a high level of chromosome instability involving telomeric DNA sequences in ras-transfected cells overexpressing ras mRNA, which could be a consequence of rapid cell cycle progression associated with a deficient telomere capping mechanism.

Modulation of pyridinium cationic lipid-DNA complex properties by pyridinium gemini surfactants and its impact on lipoplex transfection properties

PubMed Central

Sharma, Vishnu Dutt; Lees, Julia; Hoffman, Nicholas E.; Brailoiu, Eugen; Madesh, Muniswamy; Wunder, Stephanie L.; Ilies, Marc A.

2014-01-01

The study presents the effects of blending a cationic gemini surfactant into cationic lipid bilayers and its impact towards plasmid DNA compaction and delivery process. Using nanoDSC, dynamic light scattering, zeta potential and electrophoretic mobility measurements, together with transfection (2D- and 3D-) and viability assays, we identified the main physicochemical parameters of the lipid bilayers, liposomes and lipoplexes that are affected by the gemini surfactant addition. We also correlated the cationic bilayer composition with the dynamics of the DNA compaction process, and with transfection efficiency, cytotoxicity and internalization mechanism of the resultant nucleic acid complexes. We found that blending of gemini surfactant into the cationic bilayers fluidized the supramolecular assemblies, reduced the amount of positive charge required to fully compact the plasmid DNA and, in certain cases, changed the internalization mechanism of the lipoplexes. Transfection efficiency of select ternary lipoplexes derived from cationic gemini surfactants and lipids was several times superior to transfection efficiency of corresponding binary lipoplexes, also surpassing standard transfection systems. The overall impact of gemini surfactants into the formation and dynamic of cationic bilayers was found to depend heavily on the presence of co-lipids, their nature and amount present into lipoplexes. The study confirmed the possibility of combining the specific properties of pyridinium gemini surfactants and cationic lipids synergistically for obtaining efficient synthetic transfection systems with negligible cytotoxicity useful for therapeutic gene delivery. PMID:24377350

Effect of transfection and co-incubation of bovine sperm with exogenous DNA on sperm quality and functional parameters for its use in sperm-mediated gene transfer.

PubMed

Arias, María Elena; Sánchez-Villalba, Esther; Delgado, Andrea; Felmer, Ricardo

2017-02-01

Sperm-mediated gene transfer (SMGT) is based on the capacity of sperm to bind exogenous DNA and transfer it into the oocyte during fertilization. In bovines, the progress of this technology has been slow due to the poor reproducibility and efficiency of the production of transgenic embryos. The aim of the present study was to evaluate the effects of different sperm transfection systems on the quality and functional parameters of sperm. Additionally, the ability of sperm to bind and incorporate exogenous DNA was assessed. These analyses were carried out by flow cytometry and confocal fluorescence microscopy, and motility parameters were also evaluated by computer-assisted sperm analysis (CASA). Transfection was carried out using complexes of plasmid DNA with Lipofectamine, SuperFect and TurboFect for 0.5, 1, 2 or 4 h. The results showed that all of the transfection treatments promoted sperm binding and incorporation of exogenous DNA, similar to sperm incorporation of DNA alone, without affecting the viability. Nevertheless, the treatments and incubation times significantly affected the motility parameters, although no effect on the integrity of DNA or the levels of reactive oxygen species (ROS) was observed. Additionally, we observed that transfection using SuperFect and TurboFect negatively affected the acrosome integrity, and TurboFect affected the mitochondrial membrane potential of sperm. In conclusion, we demonstrated binding and incorporation of exogenous DNA by sperm after transfection and confirmed the capacity of sperm to spontaneously incorporate exogenous DNA. These findings will allow the establishment of the most appropriate method [intracytoplasmic sperm injection (ICSI) or in vitro fertilization (IVF)] of generating transgenic embryos via SMGT based on the fertilization capacity of transfected sperm.

PiggyBac transposon-mediated gene delivery efficiently generates stable transfectants derived from cultured primary human deciduous tooth dental pulp cells (HDDPCs) and HDDPC-derived iPS cells.

PubMed

Inada, Emi; Saitoh, Issei; Watanabe, Satoshi; Aoki, Reiji; Miura, Hiromi; Ohtsuka, Masato; Murakami, Tomoya; Sawami, Tadashi; Yamasaki, Youichi; Sato, Masahiro

2015-09-14

The ability of human deciduous tooth dental pulp cells (HDDPCs) to differentiate into odontoblasts that generate mineralized tissue holds immense potential for therapeutic use in the field of tooth regenerative medicine. Realization of this potential depends on efficient and optimized protocols for the genetic manipulation of HDDPCs. In this study, we demonstrate the use of a PiggyBac (PB)-based gene transfer system as a method for introducing nonviral transposon DNA into HDDPCs and HDDPC-derived inducible pluripotent stem cells. The transfection efficiency of the PB-based system was significantly greater than previously reported for electroporation-based transfection of plasmid DNA. Using the neomycin resistance gene as a selection marker, HDDPCs were stably transfected at a rate nearly 40-fold higher than that achieved using conventional methods. Using this system, it was also possible to introduce two constructs simultaneously into a single cell. The resulting stable transfectants, expressing tdTomato and enhanced green fluorescent protein, exhibited both red and green fluorescence. The established cell line did not lose the acquired phenotype over three months of culture. Based on our results, we concluded that PB is superior to currently available methods for introducing plasmid DNA into HDDPCs. There may be significant challenges in the direct clinical application of this method for human dental tissue engineering due to safety risks and ethical concerns. However, the high level of transfection achieved with PB may have significant advantages in basic scientific research for dental tissue engineering applications, such as functional studies of genes and proteins. Furthermore, it is a useful tool for the isolation of genetically engineered HDDPC-derived stem cells for studies in tooth regenerative medicine.

Photochemical internalization-mediated nonviral gene transfection: polyamine core-shell nanoparticles as gene carrier

NASA Astrophysics Data System (ADS)

Zamora, Genesis; Wang, Frederick; Sun, Chung-Ho; Trinidad, Anthony; Kwon, Young Jik; Cho, Soo Kyung; Berg, Kristian; Madsen, Steen J.; Hirschberg, Henry

2014-10-01

The overall objective of the research was to investigate the utility of photochemical internalization (PCI) for the enhanced nonviral transfection of genes into glioma cells. The PCI-mediated introduction of the tumor suppressor gene phosphatase and tensin homolog (PTEN) or the cytosine deaminase (CD) pro-drug activating gene into U87 or U251 glioma cell monolayers and multicell tumor spheroids were evaluated. In the study reported here, polyamine-DNA gene polyplexes were encapsulated in a nanoparticle (NP) with an acid degradable polyketal outer shell. These NP synthetically mimic the roles of viral capsid and envelope, which transport and release the gene, respectively. The effects of PCI-mediated suppressor and suicide genes transfection efficiency employing either "naked" polyplex cores alone or as NP-shelled cores were compared. PCI was performed with the photosensitizer AlPcS2a and λ=670-nm laser irradiance. The results clearly demonstrated that the PCI can enhance the delivery of both the PTEN or CD genes in human glioma cell monolayers and multicell tumor spheroids. The transfection efficiency, as measured by cell survival and inhibition of spheroid growth, was found to be significantly greater at suboptimal light and DNA levels for shelled NPs compared with polyamine-DNA polyplexes alone.

Gene Therapy Vectors with Enhanced Transfection Based on Hydrogels Modified with Affinity Peptides

PubMed Central

Shepard, Jaclyn A.; Wesson, Paul J.; Wang, Christine E.; Stevans, Alyson C.; Holland, Samantha J.; Shikanov, Ariella; Grzybowski, Bartosz A.; Shea, Lonnie D.

2011-01-01

Regenerative strategies for damaged tissue aim to present biochemical cues that recruit and direct progenitor cell migration and differentiation. Hydrogels capable of localized gene delivery are being developed to provide a support for tissue growth, and as a versatile method to induce the expression of inductive proteins; however, the duration, level, and localization of expression isoften insufficient for regeneration. We thus investigated the modification of hydrogels with affinity peptides to enhance vector retention and increase transfection within the matrix. PEG hydrogels were modified with lysine-based repeats (K4, K8), which retained approximately 25% more vector than control peptides. Transfection increased 5- to 15-fold with K8 and K4 respectively, over the RDG control peptide. K8- and K4-modified hydrogels bound similar quantities of vector, yet the vector dissociation rate was reduced for K8, suggesting excessive binding that limited transfection. These hydrogels were subsequently applied to an in vitro co-culture model to induce NGF expression and promote neurite outgrowth. K4-modified hydrogels promoted maximal neurite outgrowth, likely due to retention of both the vector and the NGF. Thus, hydrogels modified with affinity peptides enhanced vector retention and increased gene delivery, and these hydrogels may provide a versatile scaffold for numerous regenerative medicine applications. PMID:21514659

Structure-transfection activity relationships in a series of novel cationic lipids with heterocyclic head-groups.

PubMed

Ivanova, Ekaterina A; Maslov, Mikhail A; Kabilova, Tatyana O; Puchkov, Pavel A; Alekseeva, Anna S; Boldyrev, Ivan A; Vlassov, Valentin V; Serebrennikova, Galina A; Morozova, Nina G; Zenkova, Marina A

2013-11-07

Cationic liposomes are promising candidates for the delivery of various therapeutic nucleic acids. Here, we report a convenient synthesis of carbamate-type cationic lipids with various hydrophobic domains (tetradecanol, dialkylglycerol, cholesterol) and positively charged head-groups (pyridinium, N-methylimidazolium, N-methylmorpholinium) and data on the structure-transfection activity relationships. It was found that single-chain lipids possess high surface activity, which correlates with high cytotoxicity due to their ability to disrupt the cellular membrane by combined hydrophobic and electrostatic interactions. Liposomes containing these lipids also display high cytotoxicity with respect to all cell lines. Irrespective of chemical structures, all cationic lipids form liposomes with similar sizes and surface potentials. The characteristics of complexes composed of cationic liposomes and nucleic acids depend mostly on the type of nucleic acid and P/N ratios. In the case of oligodeoxyribonucleotide delivery, the transfection activity depends on the type of cationic head-group regardless of the type of hydrophobic domain: all types of cationic liposomes mediate efficient oligonucleotide transfer into 80-90% of the eukaryotic cells, and liposomes based on lipids with N-methylmorpholinium cationic head-group display the highest transfection activity. In the case of plasmid DNA and siRNA, the type of hydrophobic domain determines the transfection activity: liposomes composed of cholesterol-based lipids were the most efficient in DNA transfer, while liposomes containing glycerol-based lipids exhibited reasonable activity in siRNA delivery under serum-free conditions.

Femtosecond laser assisted photo-transfection and differentiation of mouse embryonic stem cells

NASA Astrophysics Data System (ADS)

Thobakgale, Lebogang; Manoto, Sello; Ombinda Lemboumba, Satuurnin; Maaza, Malik; Mthunzi-Kufa, Patience

2018-02-01

In tissue engineering research, stem cells have been used as starting material in the synthesis of mammalian cells for the treatment of various cell based diseases. This is done by manipulating the DNA content of the cells to induce a specific effect such as increased proliferation or developing a new cell type through the process of differentiation. Such controlled gene expression of stem cells is achieved by the method of transfection, where exogenous plasmid deoxyribonucleic acid (pDNA) is inserted into a stem cell using chemical, viral or physical methods. In this research, we used femtosecond (fs) laser pulses from a home-build microscope system to perforate the cellular membrane and allow entry of selected pDNA to alter the behaviour of mouse embryonic stem cells (mESCs). In one set of experiments, we induce fluorescence on mESCs using green fluorescence protein plasmid (pGFP) while in other tests; differentiation of mESCs into endoderm cells is performed using Sox-17 plasmid DNA (pSox-17). Primitive endoderm formation was thereafter confirmed using polymerase chain reactions (PCR) and the Sox-17 primer. Cell viability studies using adenosine triphosphate were also conducted. From the data, it was concluded that the photo-transfection method is biocompatible since it was able to induce fluorescence in mESCs. Secondly, it was confirmed that Sox-17 was photo-transfected successfully using 6 μW laser power, 128 fs pulses and 1kHz pulse repetition rate.

Local and Systemic Response of Mice to Interferon-α1 -Transfected Friend Leukemia Cells

PubMed Central

Gabriele, Lucia; Kaido, Thomas; Woodrow, David; Moss, Jill; Ferrantini, Maria; Proletti, Enrico; Santodonato, Laura; Rozera, Carmela; Maury, Chantal; Gresser, Ion

1995-01-01

DBA/2 mice were injected subcutaneously with an interferon (IFN)-α/-resistant line of Friend erythroleukemia cells (FLC) transfected with the mouse IFN-α1 gene. These tumor cells produced IFN constitutively, and mice had persistently high levels of IFN in the circulation. We examined the IFN-induced host mechanisms responsible for the local inhibition of growth of these IFN-α-transfected FLC and some of the unusual systemic effects of constant interferonemia such as extramedullary hematopoiesis in the liver, an increase in myeloid cells in the spleen, and persistently elevated splenic natural killer (NK) cell activity. In addition, both DBA/2 +/bg and beige mice developed a rapid and specific resistance to intravenous challenge with parental FLC In previous experiments DBA/2 beige mice could not be protected by exogenous IFN-α/β. The differences in the response of mice to the constitutive production of IFN-α by IFN-α-transfected tumor cells and their response to exogenous IFN is discussed in terms of the effects of IFN on the host and of antitumor therapy. ImagesFigure 2Figure 3Figure 4Figure 5Figure 6 PMID:7639337

DEVELOPMENT OF AN ENVIRONMENTAL ESTROGEN SCREEN USING TRANSIENTLY TRANSFECTED RAINBOW TROUT CELL LINES

EPA Science Inventory

Rainbow troutp hepatoma (RTH-149) and gonad cells (RTG-2) were used to develop a screening protocol for estrogen disrupting chemicals. Transfection of an estrogen-responsive luciferase reporter plasmid into...

Blueberry antagonism of C-2 ceramide disruption of Ca2+ responses and recovery in MAChR-transfected COS-7 cells involves alterations in stress signaling

USDA-ARS?s Scientific Manuscript database

Muscarinic receptors (MAChRs) show loss of sensitivity in aging and AD, and are selectively sensitive to oxidative stress sensitivity (OSS), transfected (tn) with MAChR subtype M1 showing > OSS [the ability of the cell to extrude or sequester Ca2+ following depolarization (Recovery) by oxotremorine ...

Computational modeling of epithelial fluid and ion transport in the parotid duct after transfection of human aquaporin-1

PubMed Central

Chiorini, John A; Sneyd, James; Suresh, Vinod

2017-01-01

Previous studies have shown that localized delivery of the aquaporin-1 (AQP1) gene to the parotid duct can restore saliva flow in minipigs following irradiation-induced salivary hypofunction. The resulting flow rate and electrochemistry of secreted saliva contradicts current understanding of ductal fluid transport. We hypothesized that changes in expression of ion transport proteins have occurred following AQP1 transfection. We use a mathematical model of ion and fluid transport across the parotid duct epithelial cells to predict the expression profile of ion transporters that are consistent with the experimental measurements of saliva composition and secretion rates. Using a baseline set of parameters, the model reproduces the data for the irradiated, non-AQP1-transfected case. We propose three scenarios which may have occurred after transfection, which differ in the location of the AQP1 gene. The first scenario places AQP1 within nonsecretory cells, and requires that epithelial sodium channel (ENaC) expression is greatly reduced (1.3% of baseline), and ductal bicarbonate concentration is increased from 40.6 to 137.0 mM, to drive water secretion into the duct. The second scenario introduces the AQP1 gene into all ductal cells. The final scenario has AQP1 primarily in the proximal duct cells which secrete water under baseline conditions. We find the change in the remaining cells includes a 95.8% reduction in ENaC expression, enabling us to reproduce all experimental ionic concentrations within 9 mM. These findings provide a mechanistic basis for the observations and will guide the further development of gene transfer therapy for salivary hypofunction. NEW & NOTEWORTHY Following transfection of aquaporin into the parotid ducts of minipigs with salivary hypofunction, the resulting increase in salivary flow rates contradicts current understanding of ductal fluid transport. We show that the change in saliva electrochemistry and flow rate can be explained by changes in

Computational modeling of epithelial fluid and ion transport in the parotid duct after transfection of human aquaporin-1.

PubMed

Fong, Shelley; Chiorini, John A; Sneyd, James; Suresh, Vinod

2017-02-01

Previous studies have shown that localized delivery of the aquaporin-1 (AQP1) gene to the parotid duct can restore saliva flow in minipigs following irradiation-induced salivary hypofunction. The resulting flow rate and electrochemistry of secreted saliva contradicts current understanding of ductal fluid transport. We hypothesized that changes in expression of ion transport proteins have occurred following AQP1 transfection. We use a mathematical model of ion and fluid transport across the parotid duct epithelial cells to predict the expression profile of ion transporters that are consistent with the experimental measurements of saliva composition and secretion rates. Using a baseline set of parameters, the model reproduces the data for the irradiated, non-AQP1-transfected case. We propose three scenarios which may have occurred after transfection, which differ in the location of the AQP1 gene. The first scenario places AQP1 within nonsecretory cells, and requires that epithelial sodium channel (ENaC) expression is greatly reduced (1.3% of baseline), and ductal bicarbonate concentration is increased from 40.6 to 137.0 mM, to drive water secretion into the duct. The second scenario introduces the AQP1 gene into all ductal cells. The final scenario has AQP1 primarily in the proximal duct cells which secrete water under baseline conditions. We find the change in the remaining cells includes a 95.8% reduction in ENaC expression, enabling us to reproduce all experimental ionic concentrations within 9 mM. These findings provide a mechanistic basis for the observations and will guide the further development of gene transfer therapy for salivary hypofunction. Following transfection of aquaporin into the parotid ducts of minipigs with salivary hypofunction, the resulting increase in salivary flow rates contradicts current understanding of ductal fluid transport. We show that the change in saliva electrochemistry and flow rate can be explained by changes in expression of ion

Fs-laser-induced Ca2+ concentration change during membrane perforation for cell transfection.

PubMed

Baumgart, J; Bintig, W; Ngezahayo, A; Lubatschowski, H; Heisterkamp, A

2010-02-01

Fs-laser based opto-perforation is a gentle method for gene transfer into sensitive cells such as stem cells or primary cells. The high selectivity and the low damage to the cell lead to a high efficiency of transfection. However, there are side effects which induce stress to the cell due to the exchange of intra- and extracellular media as well as the disintegration of the structure of biomolecules resulting from the laser exposure. Moreover, the mechanisms of the optical transfection are still unclear. In this paper, we present our study on calcium (Ca(2+)) homeostasis during cell surgery, especially during laser induced membrane perforation. We show that the manipulation of cells can induce an increase in the cytosolic Ca(2+) concentration. This increase was not observed if the manipulation of the cells was performed in absence of the extracellular calcium indicating the importance of the Ca(2+) uptake. We found, that the uptake of extracellular Ca(2+) strongly depends on the repetition rate and the irradiation time of the laser pulses. The exposure for several seconds to kHz pulses even induces Ca(2+) induced Ca(2+) release. Dependent on the location of perforation, probably in the vicinity of an intracellular Ca(2+) stock, an instantaneous intracellular Ca(2+) release can be induced. Since Ca(2+) could be involved in negative side effect by cell surgery, we propose an application of the optoperforation technique in nominal Ca(2+)-free external solution.

Characterization of nanoparticle mediated laser transfection by femtosecond laser pulses for applications in molecular medicine.

PubMed

Schomaker, Markus; Heinemann, Dag; Kalies, Stefan; Willenbrock, Saskia; Wagner, Siegfried; Nolte, Ingo; Ripken, Tammo; Murua Escobar, Hugo; Meyer, Heiko; Heisterkamp, Alexander

2015-02-03

In molecular medicine, the manipulation of cells is prerequisite to evaluate genes as therapeutic targets or to transfect cells to develop cell therapeutic strategies. To achieve these purposes it is essential that given transfection techniques are capable of handling high cell numbers in reasonable time spans. To fulfill this demand, an alternative nanoparticle mediated laser transfection method is presented herein. The fs-laser excitation of cell-adhered gold nanoparticles evokes localized membrane permeabilization and enables an inflow of extracellular molecules into cells. The parameters for an efficient and gentle cell manipulation are evaluated in detail. Efficiencies of 90% with a cell viability of 93% were achieved for siRNA transfection. The proof for a molecular medical approach is demonstrated by highly efficient knock down of the oncogene HMGA2 in a rapidly proliferating prostate carcinoma in vitro model using siRNA. Additionally, investigations concerning the initial perforation mechanism are conducted. Next to theoretical simulations, the laser induced effects are experimentally investigated by spectrometric and microscopic analysis. The results indicate that near field effects are the initial mechanism of membrane permeabilization. This methodical approach combined with an automated setup, allows a high throughput targeting of several 100,000 cells within seconds, providing an excellent tool for in vitro applications in molecular medicine. NIR fs lasers are characterized by specific advantages when compared to lasers employing longer (ps/ns) pulses in the visible regime. The NIR fs pulses generate low thermal impact while allowing high penetration depths into tissue. Therefore fs lasers could be used for prospective in vivo applications.

Transfection of cultured cells of the cotton boll weevil, Anthonomus grandis, with a heat-shock-promoter-chloramphenicol-acetyltransferase construct.

PubMed

Stiles, B; Heilmann, J; Sparks, R B; Santoso, A; Leopold, R A

1992-01-01

Expression of heat shock proteins (hsp) in the BRL-AG-3C cell line from the cotton boll weevil was examined. It was determined that the maximal expression of endogenous hsp occurred at 41 degrees C. Various transfection methods were then compared using this cell line in conjunction with a transiently expressed bacterial gene marker (chloramphenicol acetyltransferase) which was under the control of the Drosophila hsp 70 gene promoter. The cationic lipid preparation Lipofectin was found to be very efficient at transfecting the boll weevil cells. Polylysine and 20-hydroxyecdysone-conjugated polylysine were moderately effective, whereas polybrene and electroporation, under the conditions reported herein, were ineffective at transfecting this cell line.

Transfection efficiency and uptake process of polyplexes in human lung endothelial cells: a comparative study in non-polarized and polarized cells.

PubMed

Mennesson, Eric; Erbacher, Patrick; Piller, Véronique; Kieda, Claudine; Midoux, Patrick; Pichon, Chantal

2005-06-01

Following systemic administration, polyplexes must cross the endothelium barrier to deliver genes to the target cells underneath. To design an efficient gene delivery system into lung epithelium, we evaluated capture and transfection efficiencies of DNA complexed with either Jet-PEI (PEI-polyplexes) or histidylated polylysine (His-polyplexes) in human lung microvascular endothelial cells (HLMEC) and tracheal epithelial cells. After optimizing growth conditions to obtain a tight HLMEC monolayer, we characterized uptake of polyplexes by flow cytometry and evaluated their transfection efficiency. Polyplexes were formulated as small particles. YOYO-labelled plasmid fluorescence intensity and luciferase activity were used as readouts for uptake and gene expression, respectively. PEI-polyplexes were more efficiently taken up than His-polyplexes by both non-polarized (2-fold) and polarized HLMEC (10-fold). They were mainly internalized by a clathrin-dependent pathway whatever the cell state. In non-polarized cells, His-polyplexes entered also mainly via a clathrin-dependent pathway but with an involvement of cholesterol. The cell polarization decreased this way and a clathrin-independent pathway became predominant. PEI-polyplexes transfected more efficiently HLMEC than His-polyplexes (10(7) vs. 10(5) relative light units (RLU)/mg of proteins) with a more pronounced difference in polarized cells. In contrast, no negative effect of the cell polarization was observed with tracheal epithelial cells in which both polyplexes had comparable efficiency. We show that the efficiency of polyplex uptake by HLMEC and their internalization mechanism are polymer-dependent. By contrast with His-polyplexes, the HLMEC polarization has little influence on the uptake process and on the transfection efficiency of PEI-polyplexes. Copyright (c) 2005 John Wiley & Sons, Ltd.

High level transient expression of a chloramphenicol acetyl transferase gene by DEAE-dextran mediated DNA transfection coupled with a dimethyl sulfoxide or glycerol shock treatment.

PubMed Central

Lopata, M A; Cleveland, D W; Sollner-Webb, B

1984-01-01

Using a plasmid containing the bacterial chloramphenicol acetyl transferase gene, we have assayed for transient expression of DNA introduced into mouse L cells by a variety of transfection conditions. High efficiency uptake and expression of this foreign DNA have been achieved by modifying the DEAE dextran mediated transfection procedure of McCutchan and Pagano (1) to include a shock with either dimethyl sulfoxide or glycerol. Inclusion of the shock step can increase expression of the transfected gene a surprising approximately 50 fold. With plasmid constructs that do not replicate after transfection, we can readily detect CAT activity in an overnight autoradiographic exposure from less than 0.1% of an extract from a 60 mm dish of transfected cells. We have determined the amounts of DNA, the amount and time course of DEAE-dextran and dimethyl sulfoxide treatments, the effects of additional DNA, and the time after transfection which yield maximal expression. Overall, this transfection protocol using DEAE-dextran coupled to a shock treatment is simple, straightforward, and gives consistently high levels of expression of the input DNA. Images PMID:6589587

A human GRPr-transfected Ace-1 canine prostate cancer model in mice.

PubMed

Ding, Haiming; Kothandaraman, Shankaran; Gong, Li; Williams, Michelle M; Dirksen, Wessel P; Rosol, Thomas J; Tweedle, Michael F

2016-06-01

A versatile drug screening system was developed to simplify early targeted drug discovery in mice and then translate readily from mice to a dog prostate cancer model that more fully replicates the features of human prostate cancer. We stably transfected human cDNA of the GRPr bombesin (BBN) receptor subtype to canine Ace-1 prostate cancer cells (Ace-1(huGRPr) ). Expression was examined by (125) I-Tyr(4) -BBN competition, calcium stimulation assay, and fluorescent microscopy. A dual tumor nude mouse xenograft model was developed from Ace-1(CMV) (vector transfected Ace-1) and Ace-1(huGRPr) cells. The model was used to explore the in vivo behavior of two new IRDye800-labeled GRPr binding optical imaging agents: 800-G-Abz4-t-BBN, from a GRPr agonist peptide, and 800-G-Abz4-STAT, from a GRPr antagonist peptide, by imaging the tumor mice and dissected organs. Both agents bound Ace-1(huGRPr) and PC-3, a known GRPr-expressing human prostate cancer cell line, with 4-13 nM IC50 against (125) I-Tyr(4) -BBN, but did not bind Ace-1(CMV) cells (vector transfected). Binding was blocked by bombesin. Ca(2+) activation assays demonstrated that Ace-1(huGPRr) expressed biologically active GRPr. Both Ace-1 cell lines grew in the flanks of 100% of the nude mice and formed tumors of ∼0.5 cm diameter in 1 week. In vivo imaging of the mice at 800 nm emission showed GRPr+: GRPr- tumor signal brighter by a factor of two at 24 h post IV administration of 10 nmol of the imaging agents. Blood retention (4-8% ID at 1 h) was greater by a factor >10 and cumulative urine accumulation (28-30% at 4 h) was less by a factor 2 compared to a radioactive analog of the t-BBN containing agent, (177) LuAMBA, probably due to binding to blood albumin, which we confirmed in a mouse serum assay. The dual tumor Ace-1(CMV) /Ace-1(huGRPr) model system provides a rapid test of specific to nonspecific binding of new GRPr avid agents in a model that will extend logically to the known Ace-1 orthotopic

[The transfection and expression of IL-1ra gene to the rabbit cornea in situ via cation polymer mediation].

PubMed

Yuan, Jin; Chen, Jia-qi; Zhou, Shi-you; Liu, Zu-guo; Wang, Zhi-chong; Gu, Jian-jun

2006-08-01

To investigate the efficiency and safety of transfection of PEGFP-IL-1ra plasmid via cation polymer mediation (poly-ethylenimine, PEI) by injection into the corneal stroma. Human IL-1ra cDNA fragments were cloned by RT-PCR. Plasmid PEGFP-hIL-1ra recombinants were constructed and transferred into corneal endothelial cells (CEC) via cation polymer mediation. Expression of IL-1ra mRNA and IL-1ra was detected by green fluorescent protein (GFP) and Western-blotting. In the experiment group, 20 microl preparation containing 10 microg plasmid PEGFP-hIL-1ra recombinants and PEI-in-vivo was injected into the corneal stroma of Wistar rats (n = 30). Equivalent PEI-in-vivo solution was injected into another 15 corneas as the controls. Corneas were harvested at different time points (day 1, 3, 6, 14 and 21) after injection. The changes of tissue structure and function after IL-1ra in situ transfection were studied by HE staining, transmission electron microscopy, trypan blue-alizarin red staining and immunohistochemistry. The location and intensity of IL-1ra-GFP fusion protein expression were monitored by fluorescence microscopy. The size of the RT-PCR product of hIL-1ra fragments was approximately 500 bp in agarose gel electrophoresis. Restrictive enzyme digestion analysis of PstI, BamHI and DNA sequence analysis showed that expression of plasmid PEGFP-hIL-1ra recombinants had been constructed successfully. Twelve hours after the transfection of PEGFP-hIL-1ra, GFP fluorescence was detected in 10% - 15% endothelial cells. IL-1ra protein (RMW: 44,000) was detected by Western-blotting. In PEGFP-hIL-1ra treated group, fluorescence was appeared at day 1 in cornea basal epithelial cells, peaked at day 6 in whole cornea, began to weaken at day 14, and only weak fluorescence remained in cornea epithelial cells at day 21. No fluorescence appeared in the control group. No significant pathologic changes could be found in HE stained cornea tissues in both transfected group and the

Structure-biocompatibility and transfection activity relationships of cationic polyaspartamides with (dialkylamino)alkyl and alkyl or hydroxyalkyl side groups.

PubMed

Salakhieva, Diana; Shevchenko, Vesta; Németh, Csaba; Gyarmati, Benjámin; Szilágyi, András; Abdullin, Timur

2017-01-30

A series of 14 cationic derivatives of poly(aspartic acid) i.e. cationic polyaspartamides with different (dialkylamino)alkyl and alkyl or hydroxyalkyl side groups was synthesized by nucleophilic addition on polysuccinimide. The resulting polyaspartamides have moderate amphiphilic properties. Relationships between the structure and ratio of side groups and in vitro properties of polyaspartamides, including their cytotoxic and membrane-damaging activity towards human cell lines, primary skin fibroblasts and erythrocytes, were established and discussed. Cationic polyaspartamides vary in their DNA-binding, condensing and nuclease-protecting characteristics depending on the concentration ratio of (dialkylamino)alkyl and alkyl or hydroxyalkyl side groups. Effective cell transfection was achieved upon polyaspartamide-mediated plasmid DNA delivery in serum-free medium in the presence of chloroquine. Effect of serum proteins adsorption onto polyaspartamide based polyplexes, and the role of concentration of polyplexes in culture medium in their colloidal stability and transfection process were demonstrated. Synthesized polyaspartamides are biocompatible and long-acting gene carriers, which are applied to cells after dilution and without washing, thus providing transfection level comparable to that of commercial transfection reagent. Copyright © 2016 Elsevier B.V. All rights reserved.

Differentiation of Odontoblast-Like Cells From Mouse Induced Pluripotent Stem Cells by Pax9 and Bmp4 Transfection.

PubMed

Seki, Daisuke; Takeshita, Nobuo; Oyanagi, Toshihito; Sasaki, Shutaro; Takano, Ikuko; Hasegawa, Masakazu; Takano-Yamamoto, Teruko

2015-09-01

The field of tooth regeneration has progressed in recent years, and human tooth regeneration could become viable in the future. Because induced pluripotent stem (iPS) cells can differentiate into odontogenic cells given appropriate conditions, iPS cells are a potential cell source for tooth regeneration. However, a definitive method to induce iPS cell-derived odontogenic cells has not been established. We describe a novel method of odontoblast differentiation from iPS cells using gene transfection. We generated mouse iPS cell-derived neural crest-like cells (iNCLCs), which exhibited neural crest markers. Next, we differentiated iNCLCs into odontoblast-like cells by transfection of Pax9 and Bmp4 expression plasmids. Exogenous Pax9 upregulated expression of Msx1 and dentin matrix protein 1 (Dmp1) in iNCLCs but not bone morphogenetic protein 4 (Bmp4) or dentin sialophosphoprotein (Dspp). Exogenous Bmp4 upregulated expression of Msx1, Dmp1, and Dspp in iNCLCs, but not Pax9. Moreover, cotransfection of Pax9 and Bmp4 plasmids in iNCLCs revealed a higher expression of Pax9 than when Pax9 plasmid was used alone. In contrast, exogenous Pax9 downregulated Bmp4 overexpression. Cotransfection of Pax9 and Bmp4 synergistically upregulated Dmp1 expression; however, Pax9 overexpression downregulated exogenous Bmp4-induced Dspp expression. Together, these findings suggest that an interaction between exogenous Pax9- and Bmp4-induced signaling modulated Dmp1 and Dspp expression. In conclusion, transfection of Pax9 and Bmp4 expression plasmids in iNCLCs induced gene expression associated with odontoblast differentiation, suggesting that iNCLCs differentiated into odontoblast-like cells. The iPS cell-derived odontoblast-like cells could be a useful cell source for tooth regeneration. It has been reported that induced pluripotent stem (iPS) cells differentiate into odontogenic cells by administration of recombinant growth factors and coculture with odontogenic cells. Therefore, they can

Induction of human dendritic cell maturation using transfection with RNA encoding a dominant positive toll-like receptor 4.

PubMed

Cisco, Robin M; Abdel-Wahab, Zeinab; Dannull, Jens; Nair, Smita; Tyler, Douglas S; Gilboa, Eli; Vieweg, Johannes; Daaka, Yehia; Pruitt, Scott K

2004-06-01

Maturation of dendritic cells (DC) is critical for the induction of Ag-specific immunity. Ag-loaded DC matured with LPS, which mediates its effects by binding to Toll-like receptor 4 (TLR4), induce Ag-specific CTL in vitro and in vivo in animal models. However, clinical use of LPS is limited due to potential toxicity. Therefore, we sought to mimic the maturation-inducing effects of LPS on DC by stimulating TLR4-mediated signaling in the absence of exogenous LPS. We developed a constitutively active TLR4 (caTLR4) and demonstrated that transfection of human DC with RNA encoding caTLR4 led to IL-12 and TNF-alpha secretion. Transfection with caTLR4 RNA also induced a mature DC phenotype. Functionally, transfection of DC with caTLR4 RNA enhanced allostimulation of CD4(+) T cells. DC transfected with RNA encoding the MART (Melan-A/MART-1) melanoma Ag were then used to stimulate T cells in vitro. Cotransfection of these DC with caTLR4 RNA enhanced the generation of MART-specific CTL. This CTL activity was superior to that seen when DC maturation was induced using either LPS or a standard mixture of cytokines (TNF-alpha, IL-6, IL-1beta, and PGE(2)). We conclude that transfection of DC with RNA encoding a functional signaling protein, such as caTLR4, may provide a new tool for studying TLR signaling in DC and may be a promising approach for the induction of DC maturation for tumor immunotherapy.

Structure-function relationships of new lipids designed for DNA transfection.

PubMed

Dittrich, Matthias; Heinze, Martin; Wölk, Christian; Funari, Sergio S; Dobner, Bodo; Möhwald, Helmuth; Brezesinski, Gerald

2011-08-22

Cationic liposome/DNA complexes can be used as nonviral vectors for direct delivery of DNA-based biopharmaceuticals to damaged cells and tissues. To obtain more effective and safer liposome-based gene transfection systems, two cationic lipids with identical head groups but different chain structures are investigated with respect to their in vitro gene-transfer activity, their cell-damaging characteristics, and their physicochemical properties. The gene-transfer activities of the two lipids are very different. Differential scanning calorimetry and synchrotron small- and wide-angle X-ray scattering give valuable structural insight. A subgel-like structure with high packing density and high phase-transition temperature from gel to liquid-crystalline state are found for lipid 7 (N'-2-[(2,6-diamino-1-oxohexyl)amino]ethyl-2,N-bis(hexadecyl)propanediamide) containing two saturated chains. Additionally, an ordered head-group lattice based on formation of a hydrogen-bond network is present. In contrast, lipid 8 (N'-2-[(2,6-diamino-1-oxohexyl)amino]ethyl-2-hexadecyl-N-[(9Z)-octadec-9-enyl]propanediamide) with one unsaturated and one saturated chain shows a lower phase-transition temperature and a reduced packing density. These properties enhance incorporation of the helper lipid cholesterol needed for gene transfection. Both lipids, either pure or in mixtures with cholesterol, form lamellar phases, which are preserved after addition of DNA. However, the system separates into phases containing DNA and phases without DNA. On increasing the temperature, DNA is released and only a lipid phase without intercalated DNA strands is observed. The conversion temperatures are very different in the two systems studied. The important parameter seems to be the charge density of the lipid membranes, which is a result of different solubility of cholesterol in the two lipid membranes. Therefore, different binding affinities of the DNA to the lipid mixtures are achieved. Copyright © 2011

[The preparation of recombinant adenovirus Ad-Rad50-GFP and detection of the optimal multiplicity of infection in CNE1 transfected hv Ad-Rad50-GFP].

PubMed

Yan, Ruicheng; Huang, Jiancong; Zhu, Ling; Chang, Lihong; Li, Jingjia; Wu, Xifu; Ye, Jin; Zhang, Gehua

2015-12-01

The optimal multiplicity of infection (MOI) of the recombinant adenovirus Ad-Rad50-GFP carrying a mutant Rad50 gene expression region on the cell growth of nasopharyngeal carcinoma and the viral amplification efficiency of CNE1 cell infected by this adenovirus were studied. The biological titer of Ad-Rad50-GFP was measured by end point dilution method. The impact of recombinant adenoviral vector transfection on the growth of CNE1 cells was observed by cell growth curve. Transfection efficacy of recombinant adenoviral vector was observed and calculated through fluorescence microscope. The expression f mutant Rad50 in the Ad-Rad50-GFP transfected CNE1 cells with optimal MOI was detected by Western Blot after transfection. The biological titer of Ad-Rad50-GFP was 1.26 x 10¹¹ pfu/ml. CNE1 cell growth was not influenced significantly as they were transfected by recombinant adenoviral vector with MOI less than 50. Transfection efficacy of recombinant adenoviral vector was most salient at 24 hours after transfection, with the high expression of mutant Rad50, and the efficiency still remained about 70% after 72 hours. Recombinant adenoviral vector Ad-Rad50-GFP could transfect CNE1 cells as well as result in the expression of mutant Rad50 in CNE1 cells effectively. MOI = 50 was the optimal multiplicity of infection of CNE1 cells transfected by recombinant adenoviral vector Ad-Rad50-GFP.

Amniotic Fluid Cells Show Higher Pluripotency-Related Gene Expression Than Allantoic Fluid Cells.

PubMed

Kehl, Debora; Generali, Melanie; Görtz, Sabrina; Geering, Diego; Slamecka, Jaroslav; Hoerstrup, Simon P; Bleul, Ulrich; Weber, Benedikt

2017-10-01

Amniotic fluid represents an abundant source of multipotent stem cells, referred as broadly multipotent given their differentiation potential and expression of pluripotency-related genes. However, the origin of this broadly multipotent cellular fraction is not fully understood. Several sources have been proposed so far, including embryonic and extraembryonic tissues. In this regard, the ovine developmental model uniquely allows for direct comparison of fetal fluid-derived cells from two separate fetal fluid cavities, the allantois and the amnion, over the entire duration of gestation. As allantoic fluid mainly collects fetal urine, cells originating from the efferent urinary tract can directly be compared with cells deriving from the extraembryonic amniotic tissues and the fetus. This study shows isolation of cells from the amniotic [ovine amniotic fluid cells (oAFCs)] and allantoic fluid [ovine allantoic fluid cells (oALCs)] in a strictly paired fashion with oAFCs and oALCs derived from the same fetus. Both cell types showed cellular phenotypes comparable to standard mesenchymal stem cells (MSCs), with trilineage differentiation potential, and expression of common ovine MSC markers. However, the expression of MSC markers per single cell was higher in oAFCs as measured by flow cytometry. oAFCs exhibited higher proliferative capacities and showed significantly higher expression of pluripotency-related genes OCT4, STAT3, NANOG, and REX1 by quantitative real-time polymerase chain reaction compared with paired oALCs. No significant decrease of pluripotency-related gene expression was noted over gestation, implying that cells with high differentiation potential may be isolated at the end of pregnancy. In conclusion, this study suggests that cells with highest stem cell characteristics may originate from the fetus itself or the amniotic fetal adnexa rather than from the efferent urinary tract or the allantoic fetal adnexa.

Immunological recognition of different forms of the neurotensin receptor in transfected cells and rat brain.

PubMed Central

Boudin, H; Grauz-Guyon, A; Faure, M P; Forgez, P; Lhiaubet, A M; Dennis, M; Beaudet, A; Rostene, W; Pelaprat, D

1995-01-01

In this work, the molecular forms of the rat neurotensin receptor (NTR) expressed in transfected Chinese hamster ovary (CHO) cells, in infected Sf9 insect cells and in rat cerebral cortex were immunologically detected by means of an anti-peptide antibody raised against a fragment of the third intracellular loop of the receptor. Immunoblot experiments against a fusion protein indicated that the anti-peptide antibody recognized, under denaturing conditions, the corresponding amino acid sequence within the NTR. In immunoblot analysis of membranes from NTR-transfected CHO cells, high levels of immunoreactivity were observed between 60 and 72 kDa, while only a faint labelling was observed at 47 kDa, the molecular mass deduced for the rat NTR cDNA. The bands of high molecular mass were no longer observed after deglycosylation of membrane proteins by peptide N-glycosidase F, indicating that they represented glycosylated forms of the receptor. Extracts of membranes derived from baculovirus-infected Sf9 insect-cells expressing the NTR provided a quite different immunoblot pattern, since the major band detected in that case was at 47 kDa, the molecular size of the non-glycosylated receptor. Taken together, these data show that, while most of the NTR protein was glycosylated in CHO cells, it was unglycosylated in Sf9 insect-cells. In addition, molecular sizes of the receptor proteins observed in these two cell lines differed from those obtained for the NTR endogenously expressed in the rat cerebral cortex of 7 day-old rats, where bands at 56 and 54 kDa were detected. Binding experiments carried out on membrane preparations obtained from baculovirus-infected Sf9 cells demonstrated that the immunogenic sequence was still accessible to the antibody when the receptor was embedded in the cell membrane. Immunohistochemical studies carried out on both transfected CHO cells and infected Sf9 cells confirmed this interpretation and further indicated that the antibody could be applied

Sandwiching spherical 1,2-dioleoyltrimethylammoniumpropane liposome in gold nanoparticle on solid transducer for electrochemical ultrasensitive DNA detection and transfection.

PubMed

Shankara Narayanan, Jeyaraman; Bhuvana, Mohanlal; Dharuman, Venkataraman

2014-08-15

Cationic N-[1-(2,3-Dioleoyloxy)propyl]-N,N,N-trimethylammonium propane (DOTAP) liposome is spherically sandwiched in gold nanoparticle (abbreviated as sDOTAP-AuNP) onto a gold electrode surface. The sDOTAP-AuNP is applied for electrochemical label free DNA sensing and Escherichia coli cell transfection for the first time. Complementary target (named as hybridized), non-complementary target (un-hybridized) and single base mismatch target (named as SMM) hybridized surfaces are discriminated sensitively and selectively in presence of [Fe(CN)6](3-/4-). Double strand specific intercalator methylene blue in combination with [Fe(CN)6](3-) is used to enhance target detection limit down to femtomolar concentration. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), differential pulse voltammetry (DPV) techniques are used for characterizing DNA sensing. High Resolution Transmission Electron Microscopy (HRTEM), Fourier Transform Infrared Spectroscopy (FTIR), Atomic Force Microscopy (AFM) and Dynamic Light Scattering (DLS) techniques are used to confirm the spherical nature of the sDOTAP-AuNP-DNA composite in solution and on the solid surface. DNA on the sDOTAP-ssDNA is transferred by potential stripping method (+0.2V (Ag/AgCl)) into buffer solution containing E. coli cells. The transfection is confirmed by the contrast images for the transfected and non-transfected cell from Confocal Laser Scanning Microscopy (CLSM). The results demonstrate effectiveness of the electrochemical DNA transfection method developed and could be applied for other cells. Copyright © 2014 Elsevier B.V. All rights reserved.

MACF1 Overexpression by Transfecting the 21 kbp Large Plasmid PEGFP-C1A-ACF7 Promotes Osteoblast Differentiation and Bone Formation.

PubMed

Zhang, Yan; Yin, Chong; Hu, Lifang; Chen, Zhihao; Zhao, Fan; Li, Dijie; Ma, Jianhua; Ma, Xiaoli; Su, Peihong; Qiu, Wuxia; Yang, Chaofei; Wang, Pai; Li, Siyu; Zhang, Ge; Wang, Liping; Qian, Airong; Xian, Cory J

2018-02-01

Microtubule actin crosslinking factor 1 (MACF1) is a large spectraplakin protein known to have crucial roles in regulating cytoskeletal dynamics, cell migration, growth, and differentiation. However, its role and action mechanism in bone remain unclear. The present study investigated optimal conditions for effective transfection of the large plasmid PEGFP-C1A-ACF7 (∼21 kbp) containing full-length human MACF1 cDNA, as well as the potential role of MACF1 in bone formation. To enhance MACF1 expression, the plasmid was transfected into osteogenic cells by electroporation in vitro and into mouse calvaria with nanoparticles. Then, transfection efficiency, osteogenic marker expression, calvarial thickness, and bone formation were analyzed. Notably, MACF1 overexpression triggered a drastic increase in osteogenic gene expression, alkaline phosphatase activity, and matrix mineralization in vitro. Mouse calvarial thickness, mineral apposition rate, and osteogenic marker protein expression were significantly enhanced by local transfection. In addition, MACF1 overexpression promoted β-catenin expression and signaling. In conclusion, MACF1 overexpression by transfecting the large plasmid containing full-length MACF1 cDNA promotes osteoblast differentiation and bone formation via β-catenin signaling. Current data will provide useful experimental parameters for the transfection of large plasmids and a novel strategy based on promoting bone formation for prevention and therapy of bone disorders.

Autologous dendritic cells transfected with prostate-specific antigen RNA stimulate CTL responses against metastatic prostate tumors

PubMed Central

Heiser, Axel; Coleman, Doris; Dannull, Jens; Yancey, Donna; Maurice, Margaret A.; Lallas, Costas D.; Dahm, Philipp; Niedzwiecki, Donna; Gilboa, Eli; Vieweg, Johannes

2002-01-01

Autologous dendritic cells (DCs) transfected with mRNA encoding prostate-specific antigen (PSA) are able to stimulate potent, T cell–mediated antitumor immune responses in vitro. A phase I trial was performed to evaluate this strategy for safety, feasibility, and efficacy to induce T cell responses against the self-protein PSA in patients with metastatic prostate cancer. In 13 study subjects, escalating doses of PSA mRNA–transfected DCs were administered with no evidence of dose-limiting toxicity or adverse effects, including autoimmunity. Induction of PSA-specific T cell responses was consistently detected in all patients, suggesting in vivo bioactivity of the vaccine. Vaccination was further associated with a significant decrease in the log slope PSA in six of seven subjects; three patients that could be analyzed exhibited a transient molecular clearance of circulating tumor cells. The demonstration of vaccine safety, successful in vivo induction of PSA-specific immunity, and impact on surrogate clinical endpoints provides a scientific rationale for further clinical investigation of RNA-transfected DCs in the treatment of human cancer. PMID:11828001

A herbicide-resistant ACCase 1781 Setaria mutant shows higher fitness than wild type.

PubMed

Wang, T; Picard, J C; Tian, X; Darmency, H

2010-10-01

It is often alleged that mutations conferring herbicide resistance have a negative impact on plant fitness. A mutant ACCase1781 allele endowing resistance to the sethoxydim herbicide was introgressed from a resistant green foxtail (Setaria viridis (L.) Beauv) population into foxtail millet (S. italica (L.) Beauv.). (1) Better and earlier growth of resistant plants was observed in a greenhouse cabinet. (2) Resistant plants of the advanced BC7 backcross generation showed more vigorous juvenile growth in the field, earlier flowering, more tillers and higher numbers of grains than susceptible plants did, especially when both genotypes were grown in mixture, but their seeds were lighter than susceptible seeds. (3) Field populations originating from segregating hybrids had the expected allele frequencies under normal growth conditions, but showed a genotype shift toward an excess of homozygous resistant plants within 3 years in stressful conditions. Lower seed size, lower germination rate and perhaps unexplored differences in seed longevity and predation could explain how the resistant plants have the same field fitness over the whole life cycle as the susceptible ones although they produce more seeds. More rapid growth kinetics probably accounted for higher fitness of the resistant plants in adverse conditions. The likelihood of a linkage with a beneficial gene is discussed versus the hypothesis of a pleiotropic effect of the ACCase resistance allele. It is suggested that autogamous species like Setaria could not develop a resistant population without the help of a linkage with a gene producing a higher fitness.

Increased sensitivity of glioma cells to 5-fluorocytosine following photo-chemical internalization enhanced nonviral transfection of the cytosine deaminase suicide gene

PubMed Central

Zamora, Genesis; Sun, Chung-Ho; Trinidad, Anthony; Chun, Changho; Kwon, Young Jik; Berg, Kristian; Madsen, Steen J.; Hirschberg, Henry

2014-01-01

Despite advances in surgery, chemotherapy and radiotherapy, the outcomes of patients with GBM have not significantly improved. Tumor recurrence in the resection margins occurs in more than 80 % of cases indicating aggressive treatment modalities, such as gene therapy are warranted. We have examined photochemical internalization (PCI) as a method for the non-viral transfection of the cytosine deaminase (CD) suicide gene into glioma cells. The CD gene encodes an enzyme that can convert the nontoxic antifungal agent, 5-fluorocytosine, into the chemotherapeutic drug, 5-fluorouracil. Multicell tumor spheroids derived from established rat and human glioma cell lines were used as in vitro tumor models. Plasmids containing either the CD gene alone or together with the uracil phosphoribosyl transferase (UPRT) gene combined with the gene carrier protamine sulfate were employed in all experiments. PCI was performed with the photosensitizer AlPcS2a and 670 nm laser irradiance. Protamine sulfate/CD DNA polyplexes proved nontoxic but inefficient transfection agents due to endosomal entrapment. In contrast, PCI mediated CD gene transfection resulted in a significant inhibition of spheroid growth in the presence of, but not in the absence of, 5-FC. Repetitive PCI induced transfection was more efficient at low CD plasmid concentration than single treatment. The results clearly indicate that AlPcS2a-mediated PCI can be used to enhance transfection of a tumor suicide gene such as CD, in malignant glioma cells and cells transfected with both the CD and UPRT genes had a pronounced bystander effect. PMID:24610460

SPARC Expression Is Selectively Suppressed in Tumor Initiating Urospheres Isolated from As+3- and Cd+2-Transformed Human Urothelial Cells (UROtsa) Stably Transfected with SPARC.

PubMed

Slusser-Nore, Andrea; Larson-Casey, Jennifer L; Zhang, Ruowen; Zhou, Xu Dong; Somji, Seema; Garrett, Scott H; Sens, Donald A; Dunlevy, Jane R

2016-01-01

This laboratory previously analyzed the expression of SPARC in the parental UROtsa cells, their arsenite (As(+3)) and cadmium (Cd(+2))-transformed cell lines, and tumor transplants generated from the transformed cells. It was demonstrated that SPARC expression was down-regulated to background levels in Cd(+2)-and As(+3)-transformed UROtsa cells and tumor transplants compared to parental cells. In the present study, the transformed cell lines were stably transfected with a SPARC expression vector to determine the effect of SPARC expression on the ability of the cells to form tumors in immune-compromised mice. Real time PCR, western blotting, immunohistochemistry, and immunofluorescence were used to define the expression of SPARC in the As(+3)-and Cd(+2)-transformed cell lines, and urospheres isolated from these cell lines, following their stable transfection with an expression vector containing the SPARC open reading frame (ORF). Transplantation of the cultured cells into immune-compromised mice by subcutaneous injection was used to assess the effect of SPARC expression on tumors generated from the above cell lines and urospheres. It was shown that the As(+3)-and Cd(+2)-transformed UROtsa cells could undergo stable transfection with a SPARC expression vector and that the transfected cells expressed both SPARC mRNA and secreted protein. Tumors formed from these SPARC-transfected cells were shown to have no expression of SPARC. Urospheres isolated from cultures of the SPARC-transfected As(+3)-and Cd(+2)-transformed cell lines were shown to have only background expression of SPARC. Urospheres from both the non-transfected and SPARC-transfected cell lines were tumorigenic and thus fit the definition for a population of tumor initiating cells. Tumor initiating cells isolated from SPARC-transfected As(+3)-and Cd(+2)-transformed cell lines have an inherent mechanism to suppress the expression of SPARC mRNA.

SPARC Expression Is Selectively Suppressed in Tumor Initiating Urospheres Isolated from As+3- and Cd+2-Transformed Human Urothelial Cells (UROtsa) Stably Transfected with SPARC

PubMed Central

Slusser-Nore, Andrea; Larson-Casey, Jennifer L.; Zhang, Ruowen; Zhou, Xu Dong; Somji, Seema; Garrett, Scott H.; Sens, Donald A.; Dunlevy, Jane R.

2016-01-01

Background This laboratory previously analyzed the expression of SPARC in the parental UROtsa cells, their arsenite (As+3) and cadmium (Cd+2)-transformed cell lines, and tumor transplants generated from the transformed cells. It was demonstrated that SPARC expression was down-regulated to background levels in Cd+2-and As+3-transformed UROtsa cells and tumor transplants compared to parental cells. In the present study, the transformed cell lines were stably transfected with a SPARC expression vector to determine the effect of SPARC expression on the ability of the cells to form tumors in immune-compromised mice. Methods Real time PCR, western blotting, immunohistochemistry, and immunofluorescence were used to define the expression of SPARC in the As+3-and Cd+2-transformed cell lines, and urospheres isolated from these cell lines, following their stable transfection with an expression vector containing the SPARC open reading frame (ORF). Transplantation of the cultured cells into immune-compromised mice by subcutaneous injection was used to assess the effect of SPARC expression on tumors generated from the above cell lines and urospheres. Results It was shown that the As+3-and Cd+2-transformed UROtsa cells could undergo stable transfection with a SPARC expression vector and that the transfected cells expressed both SPARC mRNA and secreted protein. Tumors formed from these SPARC-transfected cells were shown to have no expression of SPARC. Urospheres isolated from cultures of the SPARC-transfected As+3-and Cd+2-transformed cell lines were shown to have only background expression of SPARC. Urospheres from both the non-transfected and SPARC-transfected cell lines were tumorigenic and thus fit the definition for a population of tumor initiating cells. Conclusions Tumor initiating cells isolated from SPARC-transfected As+3-and Cd+2-transformed cell lines have an inherent mechanism to suppress the expression of SPARC mRNA. PMID:26783756

Transfection of apoptosis related gene Fas ligand in human hepatocellular carcinoma cells and its significance in apoptosis

PubMed Central

Chen, Jun; Su, Xian-Shi; Jiang, Yong-Fang; Gong, Guo-Zhong; Zheng, Yu-Huang; Li, Gui-Yuan

2005-01-01

AIM: To evaluate the expression of apoptosis related gene Fas ligand (FasL) in human hepatocellular carcinoma (HCC) cells HepG2 and its significance in apoptosis. METHODS: Levels of soluble Fas ligand (sFasL) in a group of patients with hepatitis B virus (HBV)-induced chronic hepatitis, HBV-positive liver cirrhosis and HCC were evaluated. In a further study, the recombinant eukaryotic expression plasmid pcDNA3.1hisB-FasL was transfected into HCC cells HepG2 by lipofection, and then soluble FasL was examined in the supernatant of culture cells by EIA, FasL expression in HepG2 cells was detected by immuohistochemistry. After being stained by annexin V and propidium iodine, cells were passed through a flow cytometer and examined by a fluorescence microscope and a laser scanning microscope. RESULTS: The sFasL levels were significantly lower in patients with HCC when compared to the patients with hepatitis or liver cirrhosis. In comparison with untransfected cells, the soluble FasL could be detected in the supernatant of transfected cells. FasL was expressed on the membranes and cytoplasm of transfected cells. The apoptotic cell rate was 36.30% in transfected cells, and was 11.53% in untransfected cells. Moreover, the different stage of apoptotic cells could be distinguished by annexin V and propidium iodine staining. CONCLUSION: Fas ligand is an apoptotic pathway of HCC cells. PMID:15849828

Effects of pressure characteristics on transfection efficiency in laser-induced stress wave-mediated gene delivery

NASA Astrophysics Data System (ADS)

Ando, Takahiro; Sato, Shunichi; Ashida, Hiroshi; Obara, Minoru

2013-07-01

Laser-induced stress waves (LISWs) generated by irradiating a light-absorbing medium with a pulsed laser can transiently increase the permeability of cell membranes for gene delivery. In this study, we investigated the effects of pressure characteristics of LISWs upon gene transfection efficiency using lasers with different pulse durations: a 6-ns pulsed Nd:YAG laser and 20-ns and 200-µs pulsed ruby lasers. LISWs were generated by irradiating a black rubber disk, on which a transparent plastic sheet was adhered for confinement of the laser-produced plasma. Rat dorsal skin was injected with plasmid DNA coding for luciferase, to which LISWs were applied. With nanosecond laser pulses, transfection efficiency increased linearly with increasing positive peak pressure in the range of 35 to 145 MPa, the corresponding impulse ranging from 10 to 40 Paṡs. With 200-µs laser pulses, on the other hand, efficient gene expression was observed by the application of LISWs even with a 10-fold-lower peak pressure (˜5 MPa), the corresponding impulse being as large as 430 Paṡs. These results indicate that even at low peak pressures, efficient transfection can be achieved by extending the pressure duration and hence by increasing the impulse of LISWs, while the averaged expression efficiencies were relatively low.

In Vitro Repair of UV-Irradiated Micrococcus luteus Bacteriophage N1 Transfecting DNA 1

PubMed Central

Mahler, Inga; George, Jeanne; Grossman, Lawrence

1974-01-01

Calcium-treated UV-sensitive, host cell reactivation− strains of Micrococcus luteus are infected with UV-irradiated N1 DNA. In strains lacking UV endonuclease, in vitro treatment of the irradiated DNA results in transfection enhancement. PMID:4823319

Replication of poliovirus RNA and subgenomic RNA transcripts in transfected cells.

PubMed Central

Collis, P S; O'Donnell, B J; Barton, D J; Rogers, J A; Flanegan, J B

1992-01-01

Full-length and subgenomic poliovirus RNAs were transcribed in vitro and transfected into HeLa cells to study viral RNA replication in vivo. RNAs with deletion mutations were analyzed for the ability to replicate in either the absence or the presence of helper RNA by using a cotransfection procedure and Northern (RNA) blot analysis. An advantage of this approach was that viral RNA replication and genetic complementation could be characterized without first isolating conditional-lethal mutants. A subgenomic RNA with a large in-frame deletion in the capsid coding region (P1) replicated more efficiently than full-length viral RNA transcripts. In cotransfection experiments, both the full-length and subgenomic RNAs replicated at slightly reduced levels and appeared to interfere with each other's replication. In contrast, a subgenomic RNA with a similarly sized out-of-frame deletion in P1 did not replicate in transfected cells, either alone or in the presence of helper RNA. Similar results were observed with an RNA transcript containing a large in-frame deletion spanning the P1, P2, and P3 coding regions. A mutant RNA with an in-frame deletion in the P1-2A coding sequence was self-replicating but at a significantly reduced level. The replication of this RNA was fully complemented after cotransfection with a helper RNA that provided 2A in trans. A P1-2A-2B in-frame deletion, however, totally blocked RNA replication and was not complemented. Control experiments showed that all of the expected viral proteins were both synthesized and processed when the RNA transcripts were translated in vitro. Thus, our results indicated that 2A was a trans-acting protein and that 2B and perhaps other viral proteins were cis acting during poliovirus RNA replication in vivo. Our data support a model for poliovirus RNA replication which directly links the translation of a molecule of plus-strand RNA with the formation of a replication complex for minus-strand RNA synthesis. Images PMID

Cellular Transfection to Deliver Alanine-Glyoxylate Aminotransferase to Hepatocytes: A Rational Gene Therapy for Primary Hyperoxaluria-1 (PH-1)

PubMed Central

Koul, Sweaty; Johnson, Thomas; Pramanik, Saroj; Koul, Hari

2005-01-01

Background: Primary hyperoxaluria-type 1 (PH-1) is a rare autosomal recessive disorder of glyoxalate metabolism caused by deficiency in the liver-specific peroxisomal enzyme alanine-glyoxalate transaminase 1 (AGT) resulting in the increased oxidation of glyoxalate to oxalate. Accumulation of oxalate in the kidney and other soft tissues results in loss of renal function and significant morbidity. The present treatment options offer some relief in the short term, but they are not completely successful. In the present study, we tested the feasibility of corrective gene therapy for this metabolic disorder. Methods: A cDNA library was made from HepG2 cells. PCR primers were designed for the AGT sequence with modifications to preclude mistargeting during gene delivery. Amplified AGT cDNA was cloned as a fusion protein with green fluorescent protein (GFP) using the vector EGFP-C1 (Clontech) for monitoring subcellular distribution. Sequence and expression of the fusion protein was verified. Fusion protein vectors were transfected into hepatocytes by liposomal transfection. AGT expression and subcellular distribution was monitored by GFP fluorescence. Results: HepG2 cells express full-length mRNA coding for AGT as confirmed by insert size as well as sequence determination. Selective primers allowed us to generate a modified recombinant GFP-AGT fusion protein. Cellular transfections with Lipofectamine resulted in transfection efficiencies of 60–90%. The recombinant AGT did localize to peroxisomes as monitored by GFP fluorescence. Conclusions: The results demonstrate preliminary in vitro feasibility data for AGT transfection into the hepatocytes. To the best of our knowledge, this is the first study to attempt recombinant AGT gene therapy for treatment of primary hyperoxaluria-1. PMID:15849465

Transfection of neurotrophin-3 into neural stem cells using ultrasound with microbubbles to treat denervated muscle atrophy.

PubMed

Gong, Lin; Jiang, Changqing; Liu, Li; Wan, Shengxiang; Tan, Wen; Ma, Sushuang; Jia, Xiaojian; Wang, Meiwei; Hu, Azhen; Shi, Yu; Zhang, Yu; Shen, Yuanyuan; Wang, Feng; Chen, Yun

2018-01-01

Neurotrophin-3 (NT-3) has potential as a therapeutic agent for the treatment of patients with denervated muscle atrophy. However, the endogenous secretion of NT-3 is low and exogenous NT-3 lacks sufficient time to accumulate due to its short half-life. The transfection of NT-3 has been demonstrated to have a beneficial effect on denervated muscle and motor endplates. Neural stem cells (NSCs) differentiate into neurons and form motor endplate nerve-muscle connections. It has been previously demonstrated that local and noninvasive transfection can be performed using ultrasound with microbubbles (MBs). In the current study, hematoxylin and eosin, acetylcholinesterase and gold chloride staining, as well as transmission electron microscopy, were performed to verify the effects of this treatment strategy. The results demonstrated that using ultrasound with MBs for the transfection of NT-3 into NSCs, and their subsequent transplantation in vivo , attenuated the atrophy of denervated muscle and reduced motor endplate degeneration. This noninvasive, efficient and targeted treatment strategy may therefore be a potential treatment for patients with denervated muscle atrophy.

The Effects of Lipoplex Formulation Variables on the Protein Corona and Comparisons with in vitro Transfection Efficiency

PubMed Central

Betker, Jamie L.; Gomez, Joe; Anchordoquy, Thomas J.

2013-01-01

The use of lipoplexes for the intracellular delivery of nucleic acids typically involves the optimization of several parameters that are known to affect delivery. Researchers commonly vary charge ratio, and often incorporate different amounts of helper lipids (e.g., cholesterol) to optimize formulations for transfection in cell culture and in vivo. The results of such experiments are often interpreted in the context of nuclease resistance and cell association, but effects on the protein corona are usually not considered. While many studies have demonstrated that lipoplex structure and function can be dramatically compromised in the presence of serum, little attention has been paid to the adsorption of specific proteins and how this might be affected by formulation parameters. In this study, we characterize changes in the protein corona that occur as DOTAP-based lipoplexes are formulated with different amounts of cholesterol and prepared at different charge ratios. Our results demonstrate a significant effect of lipid composition on both total protein adsorption as well as the individual proteins from fetal calf serum that are associated with lipoplexes. In addition, we show that PEGylation increases protein adsorption with our formulations; effects that depend on the type of PEG conjugate employed in the lipoplex. Attempts to identify a specific protein responsible for enhancing transfection were unsuccessful. PMID:23920037

Enhanced Functional Recombinant Factor VII Production by HEK 293 Cells Stably Transfected with VKORC1 where the Gamma-Carboxylase Inhibitor Calumenin is Stably Suppressed by shRNA Transfection

PubMed Central

Wajih, Nadeem; Owen, John; Wallin, Reidar

2008-01-01

Introduction Recombinant members of the vitamin K-dependent protein family (factors IX and VII and protein C) have become important pharmaceuticals in treatment of bleeding disorders and sepsis. However, because the in vivo γ-carboxylation system in stable cell lines used for transfection has a limited capacity of post translational γ carboxylation, the recovery of fully γ-carboxylated and functional proteins is low. Materials and Methods In this work we have engineered recombinant factor VII producing HEK 293 cells to stably overexpress VKORC1, the reduced vitamin K γ-carboxylase cofactor and in addition stably silenced the γ-carboxylase inhibitory protein calumenin. Results and Conclusions Stable cell lines transfected with only a factor VII cDNA had a 9% production of functional recombinant factor VII. On the other hand, these recombinant factor VII producing cells when engineered to overexpress VKORC1 and having calumenin stably suppressed more than 80% by shRNA expression, produced 68% functional factor VII. The technology presented should be applicable to all vertebrae members of the vitamin K-dependent protein family and should lower the production cost of the clinically used factors VII, IX and protein C. PMID:18177690

Enhanced functional recombinant factor VII production by HEK 293 cells stably transfected with VKORC1 where the gamma-carboxylase inhibitor calumenin is stably suppressed by shRNA transfection.

PubMed

Wajih, Nadeem; Owen, John; Wallin, Reidar

2008-01-01

Recombinant members of the vitamin K-dependent protein family (factors IX and VII and protein C) have become important pharmaceuticals in treatment of bleeding disorders and sepsis. However, because the in vivo gamma-carboxylation system in stable cell lines used for transfection has a limited capacity of post translational gamma-carboxylation, the recovery of fully gamma-carboxylated and functional proteins is low. In this work we have engineered recombinant factor VII producing HEK 293 cells to stably overexpress VKORC1, the reduced vitamin K gamma-carboxylase cofactor and in addition stably silenced the gamma-carboxylase inhibitory protein calumenin. Stable cell lines transfected with only a factor VII cDNA had a 9% production of functional recombinant factor VII. On the other hand, these recombinant factor VII producing cells when engineered to overexpress VKORC1 and having calumenin stably suppressed more than 80% by shRNA expression, produced 68% functional factor VII. The technology presented should be applicable to all vertebrae members of the vitamin K-dependent protein family and should lower the production cost of the clinically used factors VII, IX and protein C.

Transfection of the Human Heme Oxygenase Gene Into Rabbit Coronary Microvessel Endothelial Cells: Protective Effect Against Heme and Hemoglobin Toxicity

NASA Astrophysics Data System (ADS)

Abraham, N. G.; Lavrovsky, Y.; Schwartzman, M. L.; Stoltz, R. A.; Levere, R. D.; Gerritsen, M. E.

1995-07-01

Heme oxygenase (HO) is a stress protein and has been suggested to participate in defense mechanisms against agents that may induce oxidative injury such as metals, endotoxin, heme/hemoglobin, and various cytokines. Overexpression of HO in cells might therefore protect against oxidative stress produced by certain of these agents, specifically heme and hemoglobin, by catalyzing their degradation to bilirubin, which itself has antioxidant properties. We report here the successful in vitro transfection of rabbit coronary microvessel endothelial cells with a functioning gene encoding the human HO enzyme. A plasmid containing the cytomegalovirus promoter and the human HO cDNA complexed to cationic liposomes (Lipofectin) was used to transfect rabbit endothelial cells. Cells transfected with human HO exhibited an ≈3.0-fold increase in enzyme activity and expressed a severalfold induction of human HO mRNA as compared with endogenous rabbit HO mRNA. Transfected and nontransfected cells expressed factor VIII antigen and exhibited similar acetylated low-density lipoprotein uptake (two important features that characterize endothelial cells) with >85% of cells staining positive for each marker. Moreover, cells transfected with the human HO gene acquired substantial resistance to toxicity produced by exposure to recombinant hemoglobin and heme as compared with nontransfected cells. The protective effect of HO overexpression against heme/hemoglobin toxicity in endothelial cells shown in these studies provides direct evidence that the inductive response of human HO to such injurious stimuli represents an important tissue adaptive mechanism for moderating the severity of cell damage produced by these blood components.

Fluorescent tag is not a reliable marker for small RNA transfection in the presence of serum.

PubMed

Han, Jing; Wang, Qi-Wei; Wang, Shi-Qiang

2013-09-01

Chemically synthetic siRNA and miRNA have become powerful tools to study gene function in the past decade. Fluorescent dyes covalently attached to the 5' or 3' ends of synthetic small RNAs are widely used for fluorescently imaging and detection of these RNAs. However, the reliability of fluorescent tags as small RNA markers in different conditions has not attracted enough attention. We used Cy3-labelled small RNAs to explore the reliability of fluorescent tags as small RNA markers in cell cultures involving serum. A strong Cy3-fluorescence signal was observed in the cytoplasm of the cells transfected with Cy3-miR24 in the culture medium containing fetal bovine serum (FBS), but qRT-PCR results showed that little miR24 were detected in these cells. Further study demonstrated that small RNAs were degraded in the presence of FBS, suggesting that it was Cy3-RNA fragments, rather than the original Cy3-miR24, diffused into cells. These phenomena disappeared when FBS was replaced by boiled-FBS, further supporting that the Cy3-fluorescence we observed in cells in the presence of FBS could not represent the presence of intact small RNAs. These findings addressed that fluorescent tags are not reliable for small RNA transfection in the presence of serum in culture.

Effect of Proteolytic Enzymes on Transfection and Transformation of Streptococcus lactis Protoplasts †

PubMed Central

Woskow, Steven A.; Kondo, Jeffery K.

1987-01-01

With both chymotrypsin and mutanolysin used to form protoplasts, consistent transformation frequencies of 104 to 105 transformants and transfectants per μg of DNA were achieved. The procedure was used to transform protoplasts of Streptococcus cremoris CS224 at low frequency (5 transformants per μg of DNA). Images PMID:16347474

Treatment of Parkinson's disease in rats by Nrf2 transfection using MRI-guided focused ultrasound delivery of nanomicrobubbles

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

Long, Ling; Cai, Xiaodong; Guo, Ruomi

Parkinson's disease (PD) is a very common neurological disorder. However, effective therapy is lacking. Although the blood-brain-barrier (BBB) protects the brain, it prevents the delivery of about 90% of drugs and nucleotides into the brain, thereby hindering the development of gene therapy for PD. Magnetic resonance imaging (MRI)-guided focused ultrasound delivery of microbubbles enhances the delivery of gene therapy vectors across the BBB and improves transfection efficiency. In the present study, we delivered nuclear factor E2-related factor 2 (Nrf2, NFE2L2) contained in nanomicrobubbles into the substantia nigra of PD rats by MRI-guided focused ultrasound, and we examined the effect ofmore » Nrf2 over-expression in this animal model of PD. The rat model of PD was established by injecting 6-OHDA in the right substantia nigra stereotactically. Plasmids (pDC315 or pDC315/Nrf2) were loaded onto nanomicrobubbles, and then injected through the tail vein with the assistance of MRI-guided focused ultrasound. MRI-guided focused ultrasound delivery of nanomicrobubbles increased gene transfection efficiency. Furthermore, Nrf2 gene transfection reduced reactive oxygen species levels, thereby protecting neurons in the target region. - Highlights: • MRI-guided focused ultrasound enhances gene transfection into the brain of rats. • Increased Nrf2 expression protects neurons in the rat model of PD. • Nrf2 protects neurons in PD by inhibiting ROS production.« less

Transfection of embryonated Muscovy duck eggs with a recombinant plasmid is suitable for rescue of infectious Muscovy duck parvovirus.

PubMed

Wang, Jianye; Huang, Yu; Ling, Jueyi; Wang, Zhixiang; Zhu, Guoqiang

2017-12-01

For members of the family Parvoviridae, rescue of infectious virus from recombinant plasmid is usually done in cultured cells. In this study, the whole genome of the pathogenic Muscovy duck parvovirus (MDPV) strain YY was cloned into the pBluescript II (SK) vector, generating recombinant plasmid pYY. With the aid of a transfection reagent, pYY plasmid was inoculated into 11-day-old embryonated Muscovy duck eggs via the chorioallantoic membrane route, resulting in the successful rescue of infectious virus and death of the embryos. The rescued virus exhibited pathogenicity in Muscovy ducklings similar to that of its parental strain, as evaluated based on the mortality rate. The results demonstrate that plasmid transfection in embryonated Muscovy duck eggs is a convenient and efficacious method for rescue of infectious MDPV in comparison to transfection of primary cells, which is somewhat time-consuming and laborious.

Loss of retrovirus production in JB/RH melanoma cells transfected with H-2Kb and TAP-1 genes.

PubMed

Li, M; Xu, F; Muller, J; Huang, X; Hearing, V J; Gorelik, E

1999-01-20

JB/RH1 melanoma cells, as well as other melanomas of C57BL/6 mice (B16 and JB/MS), express a common melanoma-associated antigen (MAA) encoded by an ecotropic melanoma-associated retrovirus (MelARV). JB/RH1 cells do not express the H-2Kb molecules due to down-regulation of the H-2Kb and TAP-1 genes. When JB/RH1 cells were transfected with the H-2Kb and cotransfected with the TAP-1 gene, it resulted in the appearance of H-2Kb molecules and an increase in their immunogenicity, albeit they lost expression of retrovirus-encoded MAA recognized by MM2-9B6 mAb. Loss of MAA was found to result from a complete and stable elimination of ecotropic MelARV production in the H-2Kb/TAP-1-transfected JB/RH1 cells. Northern blot analysis showed no differences in ecotropic retroviral messages in MelARV-producing and -nonproducing melanoma cells, suggesting that loss of MelARV production was not due to down-regulation of MelARV transcription. Southern blot analysis revealed several rearrangements in the proviral DNA of H-2Kb-positive JB/RH1 melanoma cells. Sequence analysis of the ecotropic proviral DNA from these cells showed numerous nucleotide substitutions, some of which resulted in the appearance of a novel intraviral PstI restriction site and the loss of a HindIII restriction site in the pol region. PCR amplification of the proviral DNAs indicates that an ecotropic provirus found in the H-2Kb-positive cells is novel and does not preexist in the parental H-2Kb-negative melanoma cells. Conversely, the ecotropic provirus of the parental JB/RH1 cells was not amplifable from the H-2Kb-positive cells. Our data indicate that stable loss of retroviral production in the H-2Kb/TAP-1-transfected melanoma cells is probably due to the induction of recombination between a productive ecotropic MelARV and a defective nonecotropic provirus leading to the generation of a defective ecotropic provirus and the loss of MelARV production and expression of the retrovirus-encoded MAA. Copyright 1999

Dual silencing of Bcl-2 and Survivin by HSV-1 vector shows better antitumor efficacy in higher PKR phosphorylation tumor cells in vitro and in vivo.

PubMed

Chen, X; Zhou, Y; Wang, J; Wang, J; Yang, J; Zhai, Y; Li, B

2015-08-01

RNA interference (RNAi) is a promising tool for cancer therapy, but its delivery strategy is a major challenge for its application. Oncolytic herpes simplex virus type 1 (HSV-1) is not only an effective antitumor drug but also an excellent vector. Herein, RNAi of oncogenes Bcl-2 and Survivin was combined with oncolytic HSV-1 (ICP34.5-/ICP6-/ICP47-/CMV-GM-CSF) and a new vector HSV010-BS was constructed. Transfected cell viability assays and animal experiments revealed that the dual silencing of Bcl-2 and Survivin improved the antitumor effect of oncolytic HSV-1 in vitro and in vivo, while the antitumor effect was correlated with the phosphorylation levels of PKR of the tumor cells. The higher the phosphorylation levels of PKR of the tumor cells, the weaker the replication ability of oncolytic HSV-1, and the more powerful HSV010-BS was than its control vectors in inhibiting the growth of the tumor cells. The results provided direct supportive proofs for a new potential cancer therapy strategy.

Reduction-responsive multifunctional hyperbranched polyaminoglycosides with excellent antibacterial activity, biocompatibility and gene transfection capability.

PubMed

Huang, Yajun; Ding, Xiaokang; Qi, Yu; Yu, Bingran; Xu, Fu-Jian

2016-11-01

There is an increasing demand in developing of multifunctional materials with good antibacterial activity, biocompatibility and drug/gene delivery capability for next-generation biomedical applications. To achieve this purpose, in this work series of hydroxyl-rich hyperbranched polyaminoglycosides of gentamicin, tobramycin, and neomycin (HP and SS-HP with redox-responsive disulfide bonds) were readily synthesized via ring-opening reactions in a one-pot manner. Both HP and SS-HP exhibit high antibacterial activity toward Escherichia coli and Staphylococcus aureus. Meanwhile, the hemolysis assay of the above materials shows good biocompatibility. Moreover, SS-HPs show excellent gene transfection efficiency in vitro due to the breakdown of reduction-responsive disulfide bonds. For an in vivo anti-tumor assay, the SS-HP/p53 complexes exhibit potent inhibition capability to the growth of tumors. This study provides a promising approach for the design of next-generation multifunctional biomedical materials. Copyright © 2016 Elsevier Ltd. All rights reserved.

Uptake and transfection with polymeric nanoparticles are dependent on polymer end-group structure, but largely independent of nanoparticle physical and chemical properties

PubMed Central

Sunshine, Joel C.; Peng, Daniel Y.; Green, Jordan J.

2012-01-01

Development of non-viral particles for gene delivery requires a greater understanding of the properties that enable gene delivery particles to overcome the numerous barriers to intracellular DNA delivery. Linear poly(beta-amino) esters (PBAE) have shown substantial promise for gene delivery, but the mechanism behind their effectiveness is not well quantified with respect to these barriers. In this study, we synthesized, characterized, and evaluated for gene delivery an array of linear PBAEs that differed by small changes along the backbone, side chain, and end-group of the polymers. We examined particle size and surface charge, polymer molecular weight, polymer degradation rate, buffering capacity, cellular uptake, transfection, and cytotoxicity of nanoparticles formulated with these polymers. Significantly, this is the first study that has quantified how small differential structural changes to polymers of this class modulate buffering capacity and polymer degradation rate and relates these findings to gene delivery efficacy. All polymers formed positively charged (zeta potential 21–29 mV) nanosized articles (~ 150 nm). The polymers hydrolytically degraded quickly in physiological conditions, with half-lives ranging from 90 minutes to 6 hours depending on polymer structure. The PBAE buffering capacities in the relevant pH range (pH 5.1 – 7.4) varied from 34% to 95% protonable amines, and on a per mass basis, PBAEs buffered 1.4–4.6 mmol H+/g. When compared to 25 kDa branched polyethyleneimine (PEI), PBAEs buffer significantly fewer protons/mass, as PEI buffers 6.2 mmol H+/g over the same range. However, due to the relatively low cytotoxicity of PBAEs, higher polymer mass can be used to form particles than with PEI and total buffering capacity of PBAE-based particles significantly exceeds that of PEI. Uptake into COS-7 cells ranged from 0% to 95% of cells and transfection ranged from 0% to 93% of cells, depending on the base polymer structure and the end

Aspects of nonviral gene therapy: correlation of molecular parameters with lipoplex structure and transfection efficacy in pyridinium-based cationic lipids.

PubMed

Parvizi, Paria; Jubeli, Emile; Raju, Liji; Khalique, Nada Abdul; Almeer, Ahmed; Allam, Hebatalla; Manaa, Maryem Al; Larsen, Helge; Nicholson, David; Pungente, Michael D; Fyles, Thomas M

2014-01-30

This study seeks correlations between the molecular structures of cationic and neutral lipids, the lipid phase behavior of the mixed-lipid lipoplexes they form with plasmid DNA, and the transfection efficacy of the lipoplexes. Synthetic cationic pyridinium lipids were co-formulated (1:1) with the cationic lipid 1,2-dimyristoyl-sn-glycero-3-ethylphosphocholine (EPC), and these lipids were co-formulated (3:2) with the neutral lipids 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine (DOPE) or cholesterol. All lipoplex formulations exhibited plasmid DNA binding and a level of protection from DNase I degradation. Composition-dependent transfection (beta-galactosidase and GFP) and cytotoxicity was observed in Chinese hamster ovarian-K1 cells. The most active formulations containing the pyridinium lipids were less cytotoxic but of comparable activity to a Lipofectamine 2000™ control. Molecular structure parameters and partition coefficients were calculated for all lipids using fragment additive methods. The derived shape parameter values correctly correlated with observed hexagonal lipid phase behavior of lipoplexes as derived from small-angle X-ray scattering experiments. A transfection index applicable to hexagonal phase lipoplexes derived from calculated parameters of the lipid mixture (partition coefficient, shape parameter, lipoplex packing) produced a direct correlation with transfection efficiency. Copyright © 2013 Elsevier B.V. All rights reserved.

Mesenchymal Stem Cell Preparation and Transfection-free Ferumoxytol Labeling for MRI Cell Tracking.

PubMed

Liu, Li; Ho, Chien

2017-11-15

Mesenchymal stem cells (MSCs) are multipotent cells and are the most widely studied cell type for stem cell therapies. In vivo cell tracking of MSCs labeled with an FDA-approved superparamagnetic iron-oxide (SPIO) particle by magnetic resonance imaging (MRI) provides essential information, e.g., MSC engraftment, survival, and fate, thus improving cell therapy accuracy. However, current methodology for labeling MSCs with Ferumoxytol (Feraheme ® ), the only FDA-approved SPIO particle, needs transfection agents. This unit describes a new "bio-mimicry" protocol to prepare more native MSCs by using more "in vivo environment" of MSCs, so that the phagocytic activity of cultured MSCs is restored and expanded MSCs can be labeled with Ferumoxytol, without the need for transfection agents and/or electroporation. Moreover, MSCs re-size to a more native size, reducing from 32.0 to 19.5 μm. The MSCs prepared from this protocol retain more native properties and would be useful for biomedical applications and MSC-tracking studies by MRI. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

Transplantation of motoneurons derived from MASH1-transfected mouse ES cells reconstitutes neural networks and improves motor function in hemiplegic mice.

PubMed

Ikeda, Ritsuko; Kurokawa, Manae S; Chiba, Shunmei; Yoshikawa, Hideshi; Hashimoto, Takuo; Tadokoro, Mamoru; Suzuki, Noboru

2004-10-01

Mouse embryonic stem (ES) cells were transfected with a MASH1 expression vector and G418-resistant cells were selected. The MASH1-transfected cells became neuron-like appearance and expressed betaIIItubulin and panNCAM. Glial fibrillary acidic protein (GFAP) and galactocerebroside (GalC)-expressing cells were rarely detected. Half of the neural cells differentiated into the Islet1+ motoneuron lineage. Thus, we obtained motoneuron lineage-enriched neuronal cells by transfection of ES cells with MASH1. A hemiplegic model of mice was developed by cryogenic injury of the motor cortex, and motoneuron lineage-enriched neuronal cells were transplanted underneath the injured motor cortex neighboring the periventricular region. The motor function of the recipients was assessed by a beam walking and rotarod tests, whereby the results gradually improved, but little improvement was observed in vehicle injected control mice. We found that the grafted cells not only remained close to the implantation site, but also exhibited substantial migration, penetrating into the damaged lesion in a directed manner up to the cortical region. Grafted neuronal cells that had migrated into the cortex were elongated axon-positive for neurofilament middle chain (NFM). Synaptophysin immunostaining showed a positive staining pattern around the graft, suggesting that the transplanted neurons interacted with the recipient neurons to form a neural network. Our study suggests that the motoneuron lineage can be induced from ES cells, and grafted cells adapt to the host environment and can reconstitute a neural network to improve motor function of a paralyzed limb.

Transfection of mitochondria: strategy towards a gene therapy of mitochondrial DNA diseases.

PubMed Central

Seibel, P; Trappe, J; Villani, G; Klopstock, T; Papa, S; Reichmann, H

1995-01-01

Successes in classical gene therapies have been achieved by placing a corrected copy of a defective nuclear gene in cells. A similar gene replacement approach for a mutant mitochondrial genome is invariably linked to the use of a yet unavailable mitochondrial transfection vector. Here we show that DNA coupled covalently to a short mitochondrial leader peptide (chimera) can enter mitochondria via the protein import pathway, opening a new way for gene-, antisense-RNA- or antisense-DNA-delivery in molecular therapies. The import behavior of the purified chimera, composed of the amino-terminal leader peptide of the rat ornithine transcarbamylase (OTC) and a double stranded DNA molecule (17 bp or 322 bp), was tested by incubating with coupled and 'energized' rat liver mitochondria in the presence of reticulocyte lysate. The chimera was translocated with a high efficiency into the matrix of mitochondria utilizing the protein import pathway, independent from the size of its passenger DNA. Images PMID:7870573

Amiloride-enhanced gene transfection of octa-arginine functionalized calcium phosphate nanoparticles

PubMed Central

Tenkumo, Taichi; Kamano, Yuya; Egusa, Hiroshi; Sasaki, Keiichi

2017-01-01

Nanoparticles represent promising gene delivery systems in biomedicine to facilitate prolonged gene expression with low toxicity compared to viral vectors. Specifically, nanoparticles of calcium phosphate (nCaP), the main inorganic component of human bone, exhibit high biocompatibility and good biodegradability and have been reported to have high affinity for protein or DNA, having thus been used as gene transfer vectors. On the other hand, Octa-arginine (R8), which has a high permeability to cell membrane, has been reported to improve intracellular delivery systems. Here, we present an optimized method for nCaP-mediated gene delivery using an octa-arginine (R8)-functionalized nCaP vector containing a marker or functional gene construct. nCaP particle size was between 220–580 nm in diameter and all R8-functionalized nCaPs carried a positive charge. R8 concentration significantly improved nCaP transfection efficiency with high cell compatibility in human mesenchymal stem cells (hMSC) and human osteoblasts (hOB) in particular, suggesting nCaPs as a good option for non-viral vector gene delivery. Furthermore, pre-treatment with different endocytosis inhibitors identified that the endocytic pathway differed among cell lines and functionalized nanoparticles, with amiloride increasing transfection efficiency of R8-functionalized nCaPs in hMSC and hOB. PMID:29145481

Amiloride-enhanced gene transfection of octa-arginine functionalized calcium phosphate nanoparticles.

PubMed

Vanegas Sáenz, Juan Ramón; Tenkumo, Taichi; Kamano, Yuya; Egusa, Hiroshi; Sasaki, Keiichi

2017-01-01

Nanoparticles represent promising gene delivery systems in biomedicine to facilitate prolonged gene expression with low toxicity compared to viral vectors. Specifically, nanoparticles of calcium phosphate (nCaP), the main inorganic component of human bone, exhibit high biocompatibility and good biodegradability and have been reported to have high affinity for protein or DNA, having thus been used as gene transfer vectors. On the other hand, Octa-arginine (R8), which has a high permeability to cell membrane, has been reported to improve intracellular delivery systems. Here, we present an optimized method for nCaP-mediated gene delivery using an octa-arginine (R8)-functionalized nCaP vector containing a marker or functional gene construct. nCaP particle size was between 220-580 nm in diameter and all R8-functionalized nCaPs carried a positive charge. R8 concentration significantly improved nCaP transfection efficiency with high cell compatibility in human mesenchymal stem cells (hMSC) and human osteoblasts (hOB) in particular, suggesting nCaPs as a good option for non-viral vector gene delivery. Furthermore, pre-treatment with different endocytosis inhibitors identified that the endocytic pathway differed among cell lines and functionalized nanoparticles, with amiloride increasing transfection efficiency of R8-functionalized nCaPs in hMSC and hOB.

Specific transfection of inflamed brain by macrophages: a new therapeutic strategy for neurodegenerative diseases.

PubMed

Haney, Matthew J; Zhao, Yuling; Harrison, Emily B; Mahajan, Vivek; Ahmed, Shaheen; He, Zhijian; Suresh, Poornima; Hingtgen, Shawn D; Klyachko, Natalia L; Mosley, R Lee; Gendelman, Howard E; Kabanov, Alexander V; Batrakova, Elena V

2013-01-01

The ability to precisely upregulate genes in inflamed brain holds great therapeutic promise. Here we report a novel class of vectors, genetically modified macrophages that carry reporter and therapeutic genes to neural cells. Systemic administration of macrophages transfected ex vivo with a plasmid DNA (pDNA) encoding a potent antioxidant enzyme, catalase, produced month-long expression levels of catalase in the brain resulting in three-fold reductions in inflammation and complete neuroprotection in mouse models of Parkinson's disease (PD). This resulted in significant improvements in motor functions in PD mice. Mechanistic studies revealed that transfected macrophages secreted extracellular vesicles, exosomes, packed with catalase genetic material, pDNA and mRNA, active catalase, and NF-κb, a transcription factor involved in the encoded gene expression. Exosomes efficiently transfer their contents to contiguous neurons resulting in de novo protein synthesis in target cells. Thus, genetically modified macrophages serve as a highly efficient system for reproduction, packaging, and targeted gene and drug delivery to treat inflammatory and neurodegenerative disorders.

A new strategy in the treatment of chemoresistant lung adenocarcinoma via specific siRNA transfection of SRF, E2F1, Survivin, HIF and STAT3.

PubMed

Stoleriu, Mircea Gabriel; Steger, Volker; Mustafi, Migdat; Michaelis, Martin; Cinatl, Jindrich; Schneider, Wilke; Nolte, Andrea; Kurz, Julia; Wendel, Hans Peter; Schlensak, Christian; Walker, Tobias

2014-11-01

According to the actual treatment strategies of lung cancer, the current therapeutic regimen is an individualized, multidisciplinary concept. The development of chemoresistance in the last decade represents the most important obstacle to an effective treatment. In our study, we examined a new therapeutic alternative in the treatment of multiresistant lung adenocarcinoma via siRNA-specific transfection of six crucial molecules involved in lung carcinogenesis [serum response factor(SFR), E2F1, Survivin, hypoxia inducible factor1 (HIF1), HIF2 and signal transducer and activator of transcription (STAT3)]. Three chemoresistant A549 adenocarcinoma cells were cultured under standard conditions at 37°C and 5% CO2. The chemoresistance against Vinflunine, Vinorelbine and Methotrexate was induced artificially. The A549 cells were transfected for 2 h at 37°C with specific siRNA targeting SRF, E2F1, Survivin, HIF1, HIF2 and STAT3 in a non-viral manner. The efficiency of siRNA silencing was evaluated via quantitative real-time polymerase chain reaction, whereas the surviving cells after siRNA transfection as predictor factor for tumoural growth were analysed with a CASY cell counter 3 days after transfection. The response of the chemotherapeutic resistant adenocarcinoma cells after siRNA transfection was concentration-dependent at both 25 and 100 nM. The CASY analysis showed a very effective suppression of adenocarcinoma cells in Vinorelbine, Vinflunine and Methotrexate groups, with significantly better results in comparison with the control group. In our study, we emphasized that siRNA interference might represent a productive platform for further research in order to investigate whether a new regimen in the treatment of multiresistant non-small-cell lung cancer could be established in vivo in the context of a multimodal cancer therapy. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights

Transport of the placental estriol precursor 16α-hydroxy-dehydroepiandrosterone sulfate (16α-OH-DHEAS) by stably transfected OAT4-, SOAT-, and NTCP-HEK293 cells.

PubMed

Schweigmann, H; Sánchez-Guijo, A; Ugele, B; Hartmann, K; Hartmann, M F; Bergmann, M; Pfarrer, C; Döring, B; Wudy, S A; Petzinger, E; Geyer, J; Grosser, G

2014-09-01

16α-Hydroxy-dehydroepiandrosterone sulfate (16α-OH-DHEAS) mainly originates from the fetus and serves as precursor for placental estriol biosynthesis. For conversion of 16α-OH-DHEAS to estriol several intracellular enzymes are required. However, prior to enzymatic conversion, 16α-OH-DHEAS must enter the cells by carrier mediated transport. To identify these carriers, uptake of 16α-OH-DHEAS by the candidate carriers organic anion transporter OAT4, sodium-dependent organic anion transporter SOAT, Na(+)-taurocholate cotransporting polypeptide NTCP, and organic anion transporting polypeptide OATP2B1 was measured in stably transfected HEK293 cells by LC-MS-MS. Furthermore, the study aimed to localize SOAT in the human placenta. Stably transfected OAT4-HEK293 cells revealed a partly sodium-dependent transport for 16α-OH-DHEAS with an apparent Km of 23.1 ± 5.1 μM and Vmax of 485.0 ± 39.1 pmol/mg protein/min, while stably transfected SOAT- and NTCP-HEK293 cells showed uptake only under sodium conditions with Km of 319.0 ± 59.5 μM and Vmax of 1465.8 ± 118.8 pmol/mg protein/min for SOAT and Km of 51.4 ± 9.9 μM and Vmax of 1423.3 ± 109.6 pmol/mg protein/min for NTCP. In contrast, stably transfected OATP2B1-HEK293 cells did not transport 16α-OH-DHEAS at all. Immunohistochemical studies and in situ hybridization of formalin fixed and paraffin embedded sections of human late term placenta showed expression of SOAT in syncytiotrophoblasts, predominantly at the apical membrane as well as in the vessel endothelium. In conclusion, OAT4, SOAT, and NTCP were identified as carriers for the estriol precursor 16α-OH-DHEAS. At least SOAT and OAT4 seem to play a functional role for the placental estriol synthesis as both are expressed in the syncytiotrophoblast of human placenta. Copyright © 2014 Elsevier Ltd. All rights reserved.

Three-dimensional imaging of nucleolin trafficking in normal cells, transfectants, and heterokaryons

NASA Astrophysics Data System (ADS)

Ballou, Byron T.; Fisher, Gregory W.; Deng, Jau-Shyong; Hakala, Thomas R.; Srivastava, Meera; Farkas, Daniel L.

1996-04-01

The study of intracellular trafficking using labeled molecules has been aided by the development of the cyanine fluorochromes, which are easily coupled, very soluble, resist photobleaching, and fluoresce at far-red wavelengths where background fluorescence is minimal. We have used Cy3-, Cy5-, and Cy5.5-labeled antibodies, antigen-binding fragments, and specifically binding single-stranded oligonucleotides to follow expression and trafficking of nucleolin, the most abundant protein of the nucleolus. Nucleolin shuttles between the nucleolus and the cytoplasm, and is also expressed on the cell surface, allowing us to test our techniques at all three cellular sites. Differentially cyanine-labeled non-specific antibodies were used to control for non-specific binding. Similarly, the differentially labeled non-binding strand of the cloned oligonucleotide served as a control. The multimode microscope allowed us to follow both rapid and slow redistributions of labeled ligands in the same study. We also performed 3-D reconstructions of nucleolin distribution in cells using rapid acquisition and deconvolution. Microinjection of labeled ligands was used to follow intracellular distribution, while incubation of whole cells with antibody and antigen-binding fragments was used to study uptake. To unambiguously define trafficking, and eliminate the possibility of interference by cross-reactive proteins, we transfected mouse renal cell carcinoma cells that express cell surface nucleolin with human nucleolin. We used microinjection and cell surface staining with Cy3- or Cy5- labeled monoclonal antibody D3 (specific for human nucleolin) to assess the cellular distribution of the human protein. Several clones expressed human nucleolin on their surfaces and showed high levels of transport of the human protein into the mouse nucleus and nucleolus. This distribution roughly parallels that of mouse nucleolin as determined by labeled polyclonal antibody. We have used these engineered

In vitro and in vivo gene delivery using chitosan/hyaluronic acid nanoparticles: Influences of molecular mass of hyaluronic acid and lyophilization on transfection efficiency.

PubMed

Sato, Toshinori; Nakata, Mitsuhiro; Yang, Zhihong; Torizuka, Yu; Kishimoto, Satoko; Ishihara, Masayuki

2017-08-01

Lyophilization is an effective method for preserving nonviral gene vectors. To improve the stability and transgene expression of lyophilized plasmid DNA (pDNA) complexes, we coated the surfaces of pDNA/chitosan complexes with hyaluronic acid (HA) of varying molecular masses. The transgene expression of pDNA/chitosan/HA ternary complexes was characterized in vitro and in vivo. pDNA complexes were lyophilized overnight and the resultant products with spongy, porous consistencies were stored at -30, 4 or 25°C for 2 weeks. Rehydrated complexes were characterized using gel retardation assays, aiming to confirm complex formation, measure particle size and evaluate zeta potential, as well as conduct luciferase gene reporter assays. The anti-tumor effects of pDNA ternary complexes were evaluated using suicide gene (pTK) coding thymidine kinase in Huh7-implanted mice. Transfection efficiencies of pDNA/chitosan/HA ternary complexes were dependent on the average molecular masses of HA. The coating of pDNA/chitosan complexes with HA maintained the cellular transfection efficiencies of lyophilized pDNA ternary complexes. Furthermore, intratumoral injection of lyophilized, rehydrated pDNA ternary complexes into tumor-bearing mice showed a significant suppression of tumor growth. The coating of pDNA/chitosan complexes with high-molecular-weight HA augmented the stability and cellular transfection ability of the complexes after lyophilization-rehydration. Copyright © 2017 John Wiley & Sons, Ltd.

Optimization of a nonviral transfection system to evaluate Cox-2 controlled interleukin-4 expression for osteoarthritis gene therapy in vitro.

PubMed

Lang, Annemarie; Neuhaus, Johannes; Pfeiffenberger, Moritz; Schröder, Erik; Ponomarev, Igor; Weber, Yvonne; Gaber, Timo; Schmidt, Michael F G

2014-01-01

Gene therapy appears to have the potential for achieving a long-term remedy for osteoarthritis (OA). However, there is a risk of adverse reactions, especially when using cytomegalovirus-controlled expression. To provide a safe application, we focused on the expression of therapeutic cytokines [e.g. interleukin (IL)-4] in a disease-responsive manner by use of the previously cloned Cox-2 promoter as 'genetic switch'. In the present study, we report the functionality of a controlled gene therapeutic system in an equine osteoarthritic cell model. Different nonviral transfection reagents were tested for their efficiency on equine chondrocytes stimulated with equine IL-1β or lipopolysaccharide to create an inflammatory environment. To optimize the transfection, we successfully redesigned the vector by excluding the internal ribosomal entry site (IRES). The functionality of our Cox-2 promoter construct with respect to expressing IL-4 was proven at the mRNA and protein levels and the anti-inflammatory potential of IL-4 was confirmed by analyzing the expression of IL-1β, IL-6, IL-8, matrix metalloproteinase (MMP)-1, MMP-3 and tumor necrosis factor (TNF)-α using a quantitative polymerase chain reaction. Nonviral transfection reagents yielded transfection rates from 21% to 44% with control vectors with and without IRES, respectively. Stimulation of equine chondrocytes resulted in a 20-fold increase of mRNA expression of IL-1β. Such exogenous stimulation of chondrocytes transfected with pNCox2-IL4 led to an increase of IL-4 mRNA expression, whereas expression of inflammatory mediators decreased. The timely link between these events confirms the anti-inflammatory potential of synthesized IL-4. We consider that this approach has significant potential for translation into a useful anti-inflammation therapy. Molecular tools such as the described therapeutic plasmid pave the way for a local-controlled, self-limiting gene therapy. Copyright © 2014 John Wiley & Sons, Ltd.

Small interfering RNA transfection against serum response factor mediates growth inhibition of benign prostatic hyperplasia fibroblasts.

PubMed

Nolte, Andrea; Aufderklamm, Stefan; Scheu, Katrin; Walker, Tobias; König, Olivia; Böttcher, Miriam; Niederlaender, Jan; Schwentner, Christian; Schlensak, Christian; Stenzl, Arnulf; Wendel, Hans Peter

2013-02-01

To treat urethral strictures of the lower urinary tract, urethrotomy is the method of choice. But this minimally invasive method suffers from poor outcome rates and leads often to restenosis of the urinary tract because of hyper-proliferating fibroblasts. Our aim is to minimize the proliferation of excessive tissue due to a new minimal invasive therapeutic approach. As an appropriate model, we isolated fibroblasts from different benign prostatic hyperplasia patients and transfected them with small interfering RNA (siRNA) against the transcription factor serum response factor (SRF), a key factor for cell cycle regulation and apoptosis. The resulting knockdown of SRF was examined on the messenger RNA level by quantitative real-time polymerase chain reaction and on the protein level by western blot. The correlation of SRF silencing and impact on cell proliferation was examined by xCELLigence, 5-bromo-2'-deoxiuridine proliferation assay, total cell counts, and senescence assay. The transfection of primary prostatic fibroblasts with SRFsiRNA revealed specific and significant knockdown of SRF, leading to significant inhibition of proliferation after the second transfection, which was revealed by proliferation assay and total cell number. The results of this study indicate a substantial role of SRF in prostatic fibroblasts and we suggest that SRF silencing might be used for the treatment of urethral strictures to achieve a durably patent urethra.

Biophysics and protein corona analysis of Janus cyclodextrin-DNA nanocomplexes. Efficient cellular transfection on cancer cells.

PubMed

Martínez-Negro, M; Caracciolo, G; Palchetti, S; Pozzi, D; Capriotti, A L; Cavaliere, C; Laganà, A; Ortiz Mellet, C; Benito, J M; García Fernández, J M; Aicart, E; Junquera, E

2017-07-01

The self-assembling processes underlining the capabilities of facially differentiated ("Janus") polycationic amphiphilic cyclodextrins (paCDs) as non-viral gene nanocarriers have been investigated by a pluridisciplinary approach. Three representative Janus paCDs bearing a common tetradecahexanoyl multitail domain at the secondary face and differing in the topology of the cluster of amino groups at the primary side were selected for this study. All of them compact pEGFP-C3 plasmid DNA and promote transfection in HeLa and MCF-7 cells, both in absence and in presence of human serum. The electrochemical and structural characteristics of the paCD-pDNA complexes (CDplexes) have been studied by using zeta potential, DLS, SAXS, and cryo-TEM. paCDs and pDNA, when assembled in CDplexes, render effective charges that are lower than the nominal ones. The CDplexes show a self-assembling pattern corresponding to multilamellar lyotropic liquid crystal phases, characterized by a lamellar stacking of bilayers of the CD-based vectors with anionic pDNA sandwiched among them. When exposed to human serum, either in the absence or in the presence of pDNA, the surface of the cationic CD-based vector becomes coated by a protein corona (PC) whose composition has been analyzed by nanoLC-MS/MS. Some of the CDplexes herein studied showed moderate-to-high transfection levels in HeLa and MCF-7 cancer cells combined with moderate-to-high cell viabilities, as determined by FACS and MTT reduction assays. The ensemble of data provides a detail picture of the paCD-pDNA-PC association processes and a rational base to exploit the protein corona for targeted gene delivery on future in vivo applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Treatment of Ischemia-Reperfusion Injury of the Skin Flap Using Human Umbilical Cord Mesenchymal Stem Cells (hUC-MSCs) Transfected with "F-5" Gene.

PubMed

Leng, Xiangfeng; Fan, Yongle; Wang, Yating; Sun, Jian; Cai, Xia; Hu, Chunnan; Ding, Xiaoying; Hu, Xiaoying; Chen, Zhengyu

2017-06-06

BACKGROUND Recent studies have shown that skin flap transplantation technique plays an important role in surgical procedures. However, there are many problems in the process of skin flap transplantation surgeries, especially ischemia-reperfusion injury, which directly affects the survival rate of the skin flap and patient prognosis after surgeries. MATERIAL AND METHODS In this study, we used a new method of the "stem cells-gene" combination therapy. The "F-5" gene fragment of heat shock protein 90-α (Hsp90-α) was transfected into human umbilical cord mesenchymal stem cells (hUC-MSCs) by genetic engineering technique. RESULTS The synergistic effects of "F-5" gene and hUC-MSCs in the treatment of ischemia-reperfusion injury of the skin flap were confirmed by histochemical and immunohistochemical methods. CONCLUSIONS This study showed that the hUC-MSCs transfected with "F-5" gene can effectively improve the repair of ischemia-reperfusion injury.

PC5-A-mediated processing of pro-neurotensin in early compartments of the regulated secretory pathway of PC5-transfected PC12 cells.

PubMed

Barbero, P; Rovère, C; De Bie, I; Seidah, N; Beaudet, A; Kitabgi, P

1998-09-25

Among the members of the proprotein convertase (PC) family, PC1 and PC2 have well established roles as prohormone convertases. Another good candidate for this role is PC5-A that has been shown to be present in the regulated secretory pathway of certain neuroendocrine tissues, but evidence that it can process prohormones is lacking. To determine whether PC5-A could function as a prohormone convertase and to compare its cleavage specificity with that of PC1 and PC2, we stably transfected the rat pheochromocytoma PC12 cell line with PC5-A and analyzed the biosynthesis and subcellular localization of the enzyme, as well as its ability to process pro-neurotensin/neuromedin N (pro-NT/NN) into active peptides. Our data showed that in transfected PC12 cells, PC5-A was converted from its 126-kDa precursor form into a 117-kDa mature form and, to a lesser extent, into a C-terminally truncated 65-kDa form of the 117-kDa product. Metabolic and immunochemical studies showed that PC5-A was sorted to early compartments of the regulated secretory pathway where it colocalized with immunoreactive NT. Furthermore, pro-NT/NN was processed in these compartments according to a pattern that differed from that previously described in PC1- and PC2-transfected PC12 cells. This pattern resembled that previously reported for pro-NT/NN processing in the adrenal medulla, a tissue known to express high levels of PC5-A. Altogether, these data demonstrate for the first time the ability of PC5-A to function as a prohormone convertase in the regulated secretory pathway and suggest a role for this enzyme in the physiological processing of pro-NT/NN.

Identification of drugs and drug metabolites as substrates of multidrug resistance protein 2 (MRP2) using triple-transfected MDCK-OATP1B1-UGT1A1-MRP2 cells

PubMed Central

Fahrmayr, C; König, J; Auge, D; Mieth, M; Fromm, MF

2012-01-01

BACKGROUND AND PURPOSE The coordinate activity of hepatic uptake transporters [e.g. organic anion transporting polypeptide 1B1 (OATP1B1)], drug-metabolizing enzymes [e.g. UDP-glucuronosyltransferase 1A1 (UGT1A1)] and efflux pumps (e.g. MRP2) is a crucial determinant of drug disposition. However, limited data are available on transport of drugs (e.g. ezetimibe, etoposide) and their glucuronidated metabolites by human MRP2 in intact cell systems. EXPERIMENTAL APPROACH Using monolayers of newly established triple-transfected MDCK-OATP1B1-UGT1A1-MRP2 cells as well as MDCK control cells, single- (OATP1B1) and double-transfected (OATP1B1-UGT1A1, OATP1B1-MRP2) MDCK cells, we therefore studied intracellular concentrations and transcellular transport after administration of ezetimibe or etoposide to the basal compartment. KEY RESULTS Intracellular accumulation of ezetimibe was significantly lower in MDCK-OATP1B1-UGT1A1-MRP2 triple-transfected cells compared with all other cell lines. Considerably higher amounts of ezetimibe glucuronide were found in the apical compartment of MDCK-OATP1B1-UGT1A1-MRP2 monolayers compared with all other cell lines. Using HEK cells, etoposide was identified as a substrate of OATP1B1. Intracellular concentrations of etoposide equivalents (i.e. parent compound plus metabolites) were affected only to a minor extent by the absence or presence of OATP1B1/UGT1A1/MRP2. In contrast, apical accumulation of etoposide equivalents was significantly higher in monolayers of both cell lines expressing MRP2 (MDCK-OATP1B1-MRP2, MDCK-OATP1B1-UGT1A1-MRP2) compared with the single-transfected (OATP1B1) and the control cell line. CONCLUSIONS AND IMPLICATIONS Ezetimibe glucuronide is a substrate of human MRP2. Moreover, etoposide and possibly also its glucuronide are substrates of MRP2. These data demonstrate the functional interplay between transporter-mediated uptake, phase II metabolism and export by hepatic proteins involved in drug disposition. PMID:21923755

Optimization of a Biomimetic Apatite Nanoparticle Delivery System for Non-viral Gene Transfection---a Simulated Body Fluid Approach

NASA Astrophysics Data System (ADS)

Das, Debobrato

Current methods for gene delivery utilize nanocarriers such as liposomes and viral vectors that may produce in vivo toxicity, immunogenicity, or mutagenesis. Moreover, these common high-cost systems have a low efficacy of gene-vehicle transport across the cell plasma membrane followed by inadequate release and weak intracellular stability of the genetic sequence. Thus, this study aims to maximize gene transfection while minimizing cytotoxicity by utilizing supersaturated blood-plasma ions derived from simulated body fluids (SBF). With favorable electrostatic interactions to create biocompatible calcium-phosphate nanoparticles (NPs) derived from biomimetic apatite (BA), results suggest that the SBF system, though naturally sensitive to reaction conditions, after optimization can serve as a tunable and versatile platform for the delivery of various types of nucleic acids. From a systematic exploration of the effects of nucleation pH, incubation temperature, and time on transfection efficiency, the study proposes distinct characteristic trends in SBF BA-NP morphology, cellular uptake, cell viability, and gene modulation. Specifically, with aggressive nucleation and growth of BA-NPs in solution (observed via scanning electron microscopy), the ensuing microenvironment imposes a more toxic cellular interaction (indicated by alamarBlue and BCA assays), limiting particle uptake (fluorescence experiments) and subsequent gene knockdown (quantitative loss of function assays). Controlled precipitation of BA-NPs function to increase particle accessibility by surrounding cells, and subsequently enhance uptake and transfection efficiency. By closely examining such trends, an optimal fabrication condition of pH 6.5-37C can be observed where particle growth is more tamed and less chaotic, providing improved, favorable cellular interactions that increase cell uptake and consequently maximize gene transfection, without compromising cellular viability.

IL-1RA gene-transfected bone marrow-derived mesenchymal stem cells in APA microcapsules could alleviate rheumatoid arthritis.

PubMed

Hu, Jianhua; Li, Hongjian; Chi, Guanhao; Yang, Zhao; Zhao, Yi; Liu, Wei; Zhang, Chao

2015-01-01

In order to investigate the encapsulation of interleukin 1 receptor antagonist (IL-RA) gene-modified mesenchymal stem cells (MSCs) in alginate-poly-L-lysine (APA) microcapsules for the persistent delivery of interleukin 1 receptor antagonist (IL-RA) to treat Rheumatoid arthritis (RA). We transfect mesenchymal stem cells with IL-RA gene, and quantify the IL-RA proteins released from the encapsulated cells followed by microencapsulation of recombinant mesenchymal stem cells, and thus observe the permeability of APA microcapsules and evaluate clinical effects after induction and treatment of collagen-induced arthritis (CIA). The concentration of IL-RA in the supernatant was determined by IL-RA ELISA kit by run in technical triplicates using samples from three separate mice. Encapsulated IL-RA gene-transfected cells were capable of constitutive delivery of IL-RA proteins for at least 30 days. Moreover, the APA microcapsules could inhibit the permeation of fluorescein isothiocyanate-conjuncted immunoglobulin G. Also, it has been found that the APA microcapsules can significantly attenuate collagen induced arthritis after delivering of APA microcapsules to rats. Our results demonstrated that the nonautologous IL-RA gene-transfected stem cells are of potential utility for RA therapy.

IL-1RA gene-transfected bone marrow-derived mesenchymal stem cells in APA microcapsules could alleviate rheumatoid arthritis

PubMed Central

Hu, Jianhua; Li, Hongjian; Chi, Guanhao; Yang, Zhao; Zhao, Yi; Liu, Wei; Zhang, Chao

2015-01-01

Objectives: In order to investigate the encapsulation of interleukin 1 receptor antagonist (IL-RA) gene-modified mesenchymal stem cells (MSCs) in alginate-poly-L-lysine (APA) microcapsules for the persistent delivery of interleukin 1 receptor antagonist (IL-RA) to treat Rheumatoid arthritis (RA). Methods: We transfect mesenchymal stem cells with IL-RA gene, and quantify the IL-RA proteins released from the encapsulated cells followed by microencapsulation of recombinant mesenchymal stem cells, and thus observe the permeability of APA microcapsules and evaluate clinical effects after induction and treatment of collagen-induced arthritis (CIA). The concentration of IL-RA in the supernatant was determined by IL-RA ELISA kit by run in technical triplicates using samples from three separate mice. Results: Encapsulated IL-RA gene-transfected cells were capable of constitutive delivery of IL-RA proteins for at least 30 days. Moreover, the APA microcapsules could inhibit the permeation of fluorescein isothiocyanate-conjuncted immunoglobulin G. Also, it has been found that the APA microcapsules can significantly attenuate collagen induced arthritis after delivering of APA microcapsules to rats. Conclusions: Our results demonstrated that the nonautologous IL-RA gene-transfected stem cells are of potential utility for RA therapy. PMID:25785047

A mechanistic dissection of polyethylenimine mediated transfection of CHO cells: to enhance the efficiency of recombinant DNA utilization.

PubMed

Mozley, Olivia L; Thompson, Ben C; Fernandez-Martell, Alejandro; James, David C

2014-01-01

In this study, we examine the molecular and cellular interactions that underpin efficient internalization and utilization of polyethylenimine (PEI):DNA complexes (polyplexes) by Chinese Hamster Ovary (CHO) cells. Cell surface polyplex binding and internalization was a biphasic process, consisting of an initial rapid Phase (I), lasting approximately 15 min, followed by a slower second Phase (II), saturating at approximately 240 min post transfection. The second Phase accounted for the majority (60-70%) of polyplex internalization. While cell surface heparan sulphate proteoglycans (HSPGs) were rapidly cointernalized with polyplexes during Phase I, cell surface polyplex binding was not dependent on HSPGs. However, Phase II polyplex internalization and HSPG regeneration onto the surface of trypsinized cells occurred at similar rates, suggesting that the rate of recycling of HSPG-containing membrane to the plasma membrane limits Phase II internalization rate. Under optimal transfection conditions, polyplexes had a near neutral surface charge (zeta potential) and cell surface binding was dependent on hydrophobic interactions, being significantly inhibited by both chemical sequestration of cholesterol from the plasma membrane and addition of nonionic surfactant. Induced alterations in polyplex zeta potential, using ferric (III) citrate to decrease surface charge and varying PEI:DNA ratio to increase surface charge, served to inhibit polyplex binding or reduce secreted alkaline phosphatase reporter expression and cell viability, respectively. To increase polyplex hydrophobicity and internalization an alkylated derivative of PEI, propyl-PEI, was chemically synthesized. Using Design of Experiments-Response Surface Modeling to optimize the transfection process, the function of propyl-PEI was compared to that of unmodified PEI in both parental CHO-S cells and a subclone (Clone 4), which exhibited superior transgene expression via an increased resistance to polyplex

Development of an electro-responsive platform for the controlled transfection of mammalian cells

NASA Astrophysics Data System (ADS)

Hook, Andrew L.; Thissen, Helmut W.; Hayes, Jason P.; Voelcker, Nicolas H.

2005-02-01

The recent development of living microarrays as novel tools for the analysis of gene expression in an in-situ environment promises to unravel gene function within living organisms. In order to significantly enhance microarray performance, we are working towards electro-responsive DNA transfection chips. This study focuses on the control of DNA adsorption and desorption by appropriate surface modification of highly doped p++ silicon. Silicon was modified by plasma polymerisation of allylamine (ALAPP), a non-toxic surface that sustains cell growth. Subsequent high surface density grafting of poly(ethylene oxide) formed a layer resistant to biomolecule adsorption and cell attachment. Spatially controlled excimer laser ablation of the surface produced micron resolution patterns of re-exposed plasma polymer whilst the rest of the surface remained non-fouling. We observed electro-stimulated preferential adsorption of DNA to the ALAPP surface and subsequent desorption by the application of a negative bias. Cell culture experiments with HEK 293 cells demonstrated efficient and controlled transfection of cells using the expression of green fluorescent protein as a reporter. Thus, these chemically patterned surfaces are promising platforms for use as living microarrays.

Optimized heterologous transfection of viable adult organotypic brain slices using an enhanced gene gun

PubMed Central

2013-01-01

Background Organotypic brain slices (OTBS) are an excellent experimental compromise between the facility of working with cell cultures and the biological relevance of using animal models where anatomical, morphological, and cellular function of specific brain regions can be maintained. The biological characteristics of OTBS can subsequently be examined under well-defined conditions. They do, however, have a number of limitations; most brain slices are derived from neonatal animals, as it is difficult to properly prepare and maintain adult OTBS. There are ample problems with tissue integrity as OTBS are delicate and frequently become damaged during the preparative stages. Notwithstanding these obstacles, the introduced exogenous proteins into both neuronal cells, and cells imbedded within tissues, have been consistently difficult to achieve. Results Following the ex vivo extraction of adult mouse brains, mounted inside a medium-agarose matrix, we have exploited a precise slicing procedure using a custom built vibroslicer. To transfect these slices we used an improved biolistic transfection method using a custom made low-pressure barrel and novel DNA-coated nanoparticles (40 nm), which are drastically smaller than traditional microparticles. These nanoparticles also minimize tissue damage as seen by a significant reduction in lactate dehydrogenase activity as well as propidium iodide (PI) and dUTP labelling compared to larger traditional gold particles used on these OTBS. Furthermore, following EYFP exogene delivery by gene gun, the 40 nm treated OTBS displayed a significantly larger number of viable NeuN and EYFP positive cells. These OTBS expressed the exogenous proteins for many weeks. Conclusions Our described methodology of producing OTBS, which results in better reproducibility with less tissue damage, permits the exploitation of mature fully formed adult brains for advanced neurobiological studies. The novel 40 nm particles are ideal for the viable

Symptomatic rotator cuff tears show higher radioisotope uptake on bone scintigraphy compared with asymptomatic tears.

PubMed

Koike, Yoichi; Sano, Hirotaka; Kita, Atushi; Itoi, Eiji

2013-09-01

Some patients with rotator cuff tears complain of pain, whereas others are asymptomatic. Previous studies have pointed out the presence of active bone metabolism in the painful shoulder, identified with increased radioisotope uptake during bone scintigraphy. Shoulders with symptomatic rotator cuff tears will demonstrate higher radioisotope uptake than shoulders with asymptomatic tears with bone scintigraphy, reflecting active bone metabolism in symptomatic tears. Cross-sectional study; Level of evidence, 3. The study consisted of 3 groups: patients with symptomatic tears (symptomatic group), patients with asymptomatic tears (asymptomatic group), and controls (no tear group). The symptomatic group consisted of 28 shoulders from 28 patients with symptomatic rotator cuff tears (pain score ≤4 on the University of California, Los Angeles [UCLA] shoulder evaluation form) who underwent bone scintigraphy followed by rotator cuff repair. Of 70 volunteers who had previously undergone bone scintigraphy for diseases unrelated to their shoulder, 34 were selected for the asymptomatic group (pain score ≥8 on the UCLA shoulder form), and 32 were selected for the no tear group. The mean radioisotope uptake in the symptomatic group was significantly higher than that in the asymptomatic group (P = .02) and the no tear group (P = .02). Ten of 28 shoulders (36%) in the symptomatic group showed increased radioisotope uptake exceeding 2 standard deviations from the mean of the no tear group. This percentage was significantly higher when compared with the asymptomatic group (0%) (P < .01). Shoulders with a symptomatic rotator cuff tear showed higher radioisotope uptake on bone scintigraphy than those with an asymptomatic tear. The radioisotope uptake in shoulders with an asymptomatic tear was comparable with that in shoulders without a tear. Positive radioisotope uptake may be associated with pain in a subgroup of patients with rotator cuff tears.

Specific Transfection of Inflamed Brain by Macrophages: A New Therapeutic Strategy for Neurodegenerative Diseases

PubMed Central

Haney, Matthew J.; Zhao, Yuling; Harrison, Emily B.; Mahajan, Vivek; Ahmed, Shaheen; He, Zhijian; Suresh, Poornima; Hingtgen, Shawn D.; Klyachko, Natalia L.; Mosley, R. Lee; Gendelman, Howard E.; Kabanov, Alexander V.; Batrakova, Elena V.

2013-01-01

The ability to precisely upregulate genes in inflamed brain holds great therapeutic promise. Here we report a novel class of vectors, genetically modified macrophages that carry reporter and therapeutic genes to neural cells. Systemic administration of macrophages transfected ex vivo with a plasmid DNA (pDNA) encoding a potent antioxidant enzyme, catalase, produced month-long expression levels of catalase in the brain resulting in three-fold reductions in inflammation and complete neuroprotection in mouse models of Parkinson's disease (PD). This resulted in significant improvements in motor functions in PD mice. Mechanistic studies revealed that transfected macrophages secreted extracellular vesicles, exosomes, packed with catalase genetic material, pDNA and mRNA, active catalase, and NF-κb, a transcription factor involved in the encoded gene expression. Exosomes efficiently transfer their contents to contiguous neurons resulting in de novo protein synthesis in target cells. Thus, genetically modified macrophages serve as a highly efficient system for reproduction, packaging, and targeted gene and drug delivery to treat inflammatory and neurodegenerative disorders. PMID:23620794

Regulated expression of the rat recombinant P2X(3) receptor in stably transfected CHO-K1 tTA cells.

PubMed

Lachnit, W G; Oglesby, I B; Gever, J R; Gever, M; Huang, C; Li, X C; Jin, H; McGivern, J G; Ford, A P

2000-07-03

In this report, the regulatable expression by tetracycline of the rat recombinant P2X(3) receptor in stably transfected Chinese hamster ovary (CHO-K1) expressing the tetracycline-controlled transactivator (tTA) is described. cDNA encoding the rat P2X(3)-receptor was subcloned into pTRE (a tetracycline-repressible expression vector) which was used to transfect stably CHO-K1 tTA cells. Using whole cell patch clamp techniques, 100 microM ATP evoked inward currents of 2.9+/-1.6 nA in transfected cells grown in the absence of tetracycline (tet-). The P2X(3) receptor protein was detectable by immunoblot as early as 24 h and protein expression levels continued to increase as much as 192 h following activation of tTA by the removal of the antibiotic. Saturation binding isotherms using [35S]ATP gamma S yielded a pK(d) of 8.2+/-0.1 and a B(max) of 31.9+/-3.5 pmol/mg protein in tet- cell membranes and a pK(d) of 8.1+/-0.1 and a B(max) of 5.8+/-0.8 pmol/mg protein in tet+ cell membranes. The agonist ligands 2MeSATP and alpha beta MeATP displaced the binding of [35S]ATP gamma S in tet- cell membranes with very high affinity, yielding pIC(50) values of 9.4+/-0.2 and 7.5+/-0. 2, respectively. In tet+ cell membrane, displacement of [35S]ATP gamma S by 2MeSATP and alpha beta MeATP was of much lower affinity (pIC(50) values of 7.8 and 6.2, respectively). ATP, ADP and UTP showed similar displacement of [35S]ATP gamma S binding in tet- and tet+ cell membranes. In other experiments, cytosolic Ca(2+) was monitored using the fluorescent indicator, fluo-3. Increases in cytosolic Ca(2+) were elicited by 100 nM alpha beta MeATP in tet- cells while no increases in cytosolic Ca(2+) were detected below 100 microM alpha beta MeATP in either tet+ cells or untransfected cells. These calcium responses to alpha beta MeATP had a pEC(50) of 6.7 and were transient, returning to baseline within 120 s. Suramin produced concentration-dependent, parallel, dextral shifts of E/[A] curves to alpha beta Me

Development of a calcium phosphate co-precipitate/poly(lactide-co-glycolide) DNA delivery system: release kinetics and cellular transfection studies.

PubMed

Kofron, Michelle D; Laurencin, Cato T

2004-06-01

One of the most common non-viral methods for the introduction of foreign deoxyribonucleic acid (DNA) into cultured cells is calcium phosphate co-precipitate transfection. This technique involves the encapsulation of DNA within a calcium phosphate co-precipitate, particulate addition to in vitro cell culture, endocytosis of the co-precipitate, and exogenous DNA expression by the transfected cell. In this study, we fabricated a novel non-viral gene transfer system by adsorbing DNA, encapsulated in calcium phosphate (DNA/Ca-P) co-precipitates, to biodegradable two- and three-dimensional poly(lactide-co-glycolide) matrices (2D-DNA/Ca-P/PLAGA, 3D-DNA/Ca-P/PLAGA). Co-precipitate release studies demonstrated an initial burst release over the first 48 h. By day 7, approximately 96% of the initially adsorbed DNA/Ca-P co-precipitate had been released. This was followed by low levels of co-precipitate release for 42 days. Polymerase chain reaction was used to demonstrate the ability of the released DNA containing co-precipitates to transfect SaOS-2 cells cultured in vitro on the 3D-DNA/Ca-P/PLAGA matrix and maintenance of the structural integrity of the exogenous DNA. In summary, a promising system for the incorporation and controlled delivery of exogenous genes encapsulated within a calcium phosphate co-precipitate from biodegradable polymeric matrices has been developed and may have applicability to the delivery of therapeutic genes and the transfection of other cell types.

Metal-organic frameworks for precise inclusion of single-stranded DNA and transfection in immune cells.

PubMed

Peng, Shuang; Bie, Binglin; Sun, Yangzesheng; Liu, Min; Cong, Hengjiang; Zhou, Wentao; Xia, Yucong; Tang, Heng; Deng, Hexiang; Zhou, Xiang

2018-04-03

Effective transfection of genetic molecules such as DNA usually relies on vectors that can reversibly uptake and release these molecules, and protect them from digestion by nuclease. Non-viral vectors meeting these requirements are rare due to the lack of specific interactions with DNA. Here, we design a series of four isoreticular metal-organic frameworks (Ni-IRMOF-74-II to -V) with progressively tuned pore size from 2.2 to 4.2 nm to precisely include single-stranded DNA (ssDNA, 11-53 nt), and to achieve reversible interaction between MOFs and ssDNA. The entire nucleic acid chain is completely confined inside the pores providing excellent protection, and the geometric distribution of the confined ssDNA is visualized by X-ray diffraction. Two MOFs in this series exhibit excellent transfection efficiency in mammalian immune cells, 92% in the primary mouse immune cells (CD4+ T cell) and 30% in human immune cells (THP-1 cell), unrivaled by the commercialized agents (Lipo and Neofect).

HBV DNA genome co-transfection procedure for the evaluation of relative fitness

PubMed Central

Sevic, Ina; Gonzalez Lopez Ledesma, Maria Mora; Flichman, Diego Martin

2017-01-01

Hepatitis B virus (HBV) has a high mutation rate and exists as a mixture of genetically different but closely related variants. We present a HBV DNA co-transfection fitness assay and use it to evaluate the relative fitness of different HBV variants in two scenarios: seroconversion process and occupation of an ecological niche. In the seroconversion experiment, subgenotype D1 (sgtD1) deletion (1763–1770) had significantly lower fitness comparing with both sgtD1 wild type and sgtD1mut G1896A, while, in the case of occupation of ecological niche experiment, the results showed the same relative fitness between all of the genotype combinations, except F1b-F4. In this case sgtF1b clearly overgrow sgtF4, which is in accordance with the observation that F1b is the most prevalent in the new infections in Argentina. In summary, we present a method aimed to evaluate HBV viral fitness which improve the analysis of the relative frequency of viral variants during the HBV infection process. PMID:28472081

AAV2 production with optimized N/P ratio and PEI-mediated transfection results in low toxicity and high titer for in vitro and in vivo applications.

PubMed

Huang, Xinping; Hartley, Antja-Voy; Yin, Yishi; Herskowitz, Jeremy H; Lah, James J; Ressler, Kerry J

2013-11-01

The adeno-associated virus (AAV) is one of the most useful viral vectors for gene delivery for both in vivo and in vitro applications. A variety of methods have been established to produce and characterize recombinant AAV (rAAV) vectors; however most methods are quite cumbersome and obtaining consistently high titer can be problematic. This protocol describes a triple-plasmid co-transfection approach with 25 kDa linear polyethylenimine (PEI) in 293 T cells for the production of AAV serotype 2. Seventy-two hours post-transfection, supernatant and cells were harvested and purified by a discontinuous iodixanol density gradient ultracentrifugation, then dialyzed and concentrated with an Amicon 15 100,000 MWCO concentration unit. To optimize the protocol for AAV2 production using PEI, various N/P ratios and DNA amounts were compared. We found that an N/P ratio of 40 coupled with 1.05 μg DNA per ml of media (21 μg DNA/15 cm dish) was found to produce the highest yields for viral replication and assembly measured multiple ways. The infectious units, as determined by serial dilution, were between 1×10(8) and 2×10(9) IU/ml. The genomic titer of the viral stock was determined by qPCR and ranged from 2×10(12) to 6×10(13) VG/ml. These viral vectors showed high expression both in vivo within the brain and in vitro in cell culture. The use of linear 25 kDa polyethylenamine PEI as a transfection reagent is a simple, more cost-effective, and stable means of high-throughput production of high-titer AAV serotype 2. The use of PEI also eliminates the need to change cell medium post-transfection, lowering cost and workload, while producing high-titer, efficacious AAV2 vectors for routine gene transfer. Copyright © 2013 Elsevier B.V. All rights reserved.

Spermidine/spermine N1-acetyltransferase (SSAT) activity in human small-cell lung carcinoma cells following transfection with a genomic SSAT construct.

PubMed

Murray-Stewart, Tracy; Applegren, Nancy B; Devereux, Wendy; Hacker, Amy; Smith, Renee; Wang, Yanlin; Casero, Robert A

2003-07-15

Spermidine/spermine N (1)-acetyltransferase (SSAT) activity is typically highly inducible in non-small-cell lung carcinomas in response to treatment with anti-tumour polyamine analogues, and this induction is associated with subsequent cell death. In contrast, cells of the small-cell lung carcinoma (SCLC) phenotype generally do not respond to these compounds with an increase in SSAT activity, and usually are only moderately affected with respect to growth. The goal of the present study was to produce an SSAT-overexpressing SCLC cell line to further investigate the role of SSAT in response to these anti-tumour analogues. To accomplish this, NCI-H82 SCLC cells were stably transfected with plasmids containing either the SSAT genomic sequence or the corresponding cDNA sequence. Individual clones were selected based on their ability to show induced SSAT activity in response to exposure to a polyamine analogue, and an increase in the steady-state SSAT mRNA level. Cells transfected with the genomic sequence exhibited a significant increase in basal SSAT mRNA expression, as well as enhanced SSAT activity, intracellular polyamine pool depletion and growth inhibition following treatment with the analogue N (1), N (11)-bis(ethyl)norspermine. Cells containing the transfected cDNA also exhibited an increase in the basal SSAT mRNA level, but remained phenotypically similar to vector control cells with respect to their response to analogue exposure. These studies indicate that both the genomic SSAT sequence and polyamine analogue exposure play a role in the transcriptional and post-transcriptional regulation and subsequent induction of SSAT activity in these cells. Furthermore, this is the first production of a cell line capable of SSAT protein induction from a generally unresponsive parent line.

PCOS women show significantly higher homocysteine level, independent to glucose and E2 level

PubMed Central

Eskandari, Zahra; Sadrkhanlou, Rajab-Ali; Nejati, Vahid; Tizro, Gholamreza

2016-01-01

Background: It is reasonable to think that some biochemical characteristics of follicular fluid (FF) surrounding the oocyte may play a critical role in determining the quality of oocyte and the subsequent potential needed to achieve fertilization and embryo development. Objective: This study was carried out to evaluate the levels of FF homocysteine (Hcy) in IVF candidate polycystic ovary syndrome (PCOS) women and any relationships with FF glucose and estradiol (E2) levels. Materials and Methods: In this case control study which was performed in Dr. Tizro Day Care and IVF Center 70 infertile patients were enrolled in two groups: comprising 35 PCOS and 35 non PCOS women. Long protocol was performed for all patients. FF Hcy, glucose and E2 levels were analyzed at the time of oocyte retrieval. Results: It was observed that FF Hcy level was significantly higher in PCOS patients compared with non PCOSs (p<0.01). Observations demonstrated that in PCOS group, the Hcy level increased independent to E2, glucose levels, BMI and age, while the PCOS group showed significantly higher BMI compared with non-PCOS group (p=0.03). However, no significant differences were revealed between groups for FF glucose and E2 levels. Conclusion: Present data showed that although FF glucose and E2 levels were constant in PCOS and non PCOS patients, but the FF Hcy levels in PCOS were significantly increased (p=0.01). PMID:27679823

Multifunctional Nucleus-targeting Nanoparticles with Ultra-high Gene Transfection Efficiency for In Vivo Gene Therapy

PubMed Central

Li, Ling; Li, Xia; Wu, Yuzhe; Song, Linjiang; Yang, Xi; He, Tao; Wang, Ning; Yang, Suleixin; Zeng, Yan; Wu, Qinjie; Qian, Zhiyong; Wei, Yuquan; Gong, Changyang

2017-01-01

Cancer stem cell-like cells (CSCL) are responsible for tumor recurrence associated with conventional therapy (e.g. surgery, radiation, and chemotherapy). Here, we developed a novel multifunctional nucleus-targeting nanoparticle-based gene delivery system which is capable of targeting and eradicating CSCL. These nanoparticles can facilitate efficient endosomal escape and spontaneously penetrate into nucleus without additional nuclear localization signal. They also induced extremely high gene transfection efficiency (>95%) even in culture medium containing 30% serum, which significantly surpassed that of some commercial transfection reagents, such as Lipofectamine 2000 and Lipofectamine 3000 etc. Especially, when loaded with the TRAIL gene, this system mediated remarkable depletion of CSCL. Upon systemic administration, the nanoparticles accumulated in tumor sites while sparing the non-cancer tissues and significantly inhibited the growth of tumors with no evident systemic toxicity. Taken together, our results suggest that these novel multifunctional, nucleus-targeting nanoparticles are a very promising in vivo gene delivery system capable of targeting CSCL and represent a new treatment candidate for improving the survival of cancer patients. PMID:28529641

Small interfering RNA-mediated suppression of serum response factor, E2-promotor binding factor and survivin in non-small cell lung cancer cell lines by non-viral transfection.

PubMed

Walker, Tobias; Nolte, Andrea; Steger, Volker; Makowiecki, Christina; Mustafi, Migdat; Friedel, Godehard; Schlensak, Christian; Wendel, Hans-Peter

2013-03-01

Serum response factor (SRF), E2F1 and survivin are well-known factors involved in a multitude of cancer-related regulation processes. However, to date, no suitable means has been found to apply their potential in the therapy of non-small cell lung cancer (NSCLC). This study deals with questions of small interfering ribonucleic acid (siRNA) transfection efficiency by a non-viral transfection of NSCLC cell-lines and the power of siRNA to transiently influence cell division by specific silencing. Different NSCLC cell lines were cultured under standard conditions and transfected, with specific siRNA targeting SRF, E2F1 and survivin in a non-viral manner. Cells treated with non-specific siRNA (SCR-siRNA) served as controls. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed for messenger RNA (mRNA) expression levels. Additionally, transfection efficiency was evaluated by flow cytometry. The analysis of cell proliferation was determined with a CASY cell counter 3 days after transfection with SRF or SCR-siRNA. Transfection of the NSCLC cell lines with specific siRNAs against SRF, E2F1 and survivin resulted in a very considerable reduction of the intracellular mRNA concentration. CASY confirmation of cell viability demonstrated an excellent survival of the cell lines treated with non-specific siRNA, in contrast to with application of specific siRNA. This study reports a reliable transfectability of NSCLC-cell lines by siRNA, initially in a non-viral manner, and a reproducible knockdown of the focussed targets, consequently leading to the death of the tumour cells. This constitutes a strong candidate for a new assessment strategy in the therapy of non-small cell lung cancer.

Guanidinylated polyethyleneimine-polyoxypropylene-polyoxyethylene conjugates as gene transfection agents.

PubMed

Bromberg, Lev; Raduyk, Svetlana; Hatton, T Alan; Concheiro, Angel; Rodriguez-Valencia, Cosme; Silva, Maite; Alvarez-Lorenzo, Carmen

2009-05-20

Conjugates of linear and branched polyethyleneimine (PEI) and monoamine polyether Jeffamine M-2070 (PO/EO mol ratio 10/31, 2000 Da) were synthesized through polyether activation by cyanuric chloride followed by attachment to PEI and guanidinylation by 1H-pyrazole-carboxamidine hydrochloride. The resulting guanidinylated PEI-polyether conjugates (termed gPEI-Jeffamine) efficiently complexed plasmid DNA, and their polyplexes possessed enhanced colloidal stability in the presence of serum proteins. In vitro studies with mammalian CHO-1, 3T3, and Cos-7 cell lines demonstrated improved transfection efficiency of the pCMVbeta-gal plasmid/gPEI-Jeffamine polyplexes. The guanidinylation of the amino groups of PEI and the conjugation of PEI with the Jeffamine polyether enhanced the conjugates' interaction with genetic material and reduced the cytotoxicity of the polyplexes in experiments with the L929 cell line.

Treatment of Ischemia-Reperfusion Injury of the Skin Flap Using Human Umbilical Cord Mesenchymal Stem Cells (hUC-MSCs) Transfected with “F-5” Gene

PubMed Central

Leng, Xiangfeng; Fan, Yongle; Wang, Yating; Sun, Jian; Cai, Xia; Hu, Chunnan; Ding, Xiaoying; Hu, Xiaoying; Chen, Zhenyu

2017-01-01

Background Recent studies have shown that skin flap transplantation technique plays an important role in surgical procedures. However, there are many problems in the process of skin flap transplantation surgeries, especially ischemia-reperfusion injury, which directly affects the survival rate of the skin flap and patient prognosis after surgeries. Material/Methods In this study, we used a new method of the “stem cells-gene” combination therapy. The “F-5” gene fragment of heat shock protein 90-α (Hsp90-α) was transfected into human umbilical cord mesenchymal stem cells (hUC-MSCs) by genetic engineering technique. Results The synergistic effects of “F-5” gene and hUC-MSCs in the treatment of ischemia-reperfusion injury of the skin flap were confirmed by histochemical and immunohistochemical methods. Conclusions This study showed that the hUC-MSCs transfected with “F-5” gene can effectively improve the repair of ischemia-reperfusion injury. PMID:28586321

Tumor Associated Mesenchymal Stromal Cells Show Higher Immunosuppressive and Angiogenic Properties Compared to Adipose Derived MSCs.

PubMed

Langroudi, Ladan; Hassan, Zuhair Muhammad; Soleimani, Masoud; Hashemi, Seyed Mahmoud

2015-12-01

Differentiation, migratory properties and availability of Mesenchymal Stromal Cells (MSC) have become an important part of biomedical research. However, the functional heterogeneity of cells derived from different tissues has hampered providing definitive phenotypic markers for these cells. To characterize and compare the phenotype and cytokines of adipose derived MSCs (AD-MSCs) and tumoral-MSCs (T-MSCs) isolated from mammary tumors of BALB/c mice. Immunophenotyping and in vitro differentiation tests were used for MSC characterization. Cytokine and enzyme profiles were assessed using ELISA and Real-time PCR, respectively. T-MSCs expressed significantly higher levels of HLA-DR (p=0.04). Higher levels of PGE2 and COX-2 enzyme were also observed in T-MSCs (p=0.07 and p=0.00, respectively). Additionally, T-MSCs expressed higher levels of iNOS and MMP9 (p=0.01 and p=0.01, respectively). T-MSCs were also able to induce higher levels of proliferation and migration of HUVEC endothelial cells in wound scratch assay compared to AD-MSCs (p=0.015). Functional differences showed by the surface markers of MSCs, cytokine and enzyme production indicate the effect of different microenvironments on MSCs phenotype and function.

Spatial Control of Cell Transfection Using Soluble or Solid-Phase Redox Agents and a Redox-Active Ferrocenyl Lipid

PubMed Central

Aytar, Burcu S.; Muller, John P. E.; Kondo, Yukishige; Abbott, Nicholas L.; Lynn, David M.

2013-01-01

We report principles for active, user-defined control over the locations and timing with which DNA is expressed in cells. Our approach exploits unique properties of a ferrocenyl cationic lipid that is inactive when oxidized, but active when chemically reduced. We show that methods that exert spatial control over the administration of reducing agents can lead to local activation of lipoplexes and spatial control over gene expression. The versatility of this approach is demonstrated using both soluble and solid-phase reducing agents. These methods provide control over cell transfection, including methods for remote activation and the patterning of expression using solid-phase redox agents, that are difficult to achieve using conventional lipoplexes. PMID:23965341

Spatial control of cell transfection using soluble or solid-phase redox agents and a redox-active ferrocenyl lipid.

PubMed

Aytar, Burcu S; Muller, John P E; Kondo, Yukishige; Abbott, Nicholas L; Lynn, David M

2013-09-11

We report principles for active, user-defined control over the locations and timing with which DNA is expressed in cells. Our approach exploits unique properties of a ferrocenyl cationic lipid that is inactive when oxidized, but active when chemically reduced. We show that methods that exert spatial control over the administration of reducing agents can lead to local activation of lipoplexes and spatial control over gene expression. The versatility of this approach is demonstrated using both soluble and solid-phase reducing agents. These methods provide control over cell transfection, including methods for remote activation and the patterning of expression using solid-phase redox agents, that are difficult to achieve using conventional lipoplexes.

Efficient transformation of oil palm protoplasts by PEG-mediated transfection and DNA microinjection.

PubMed

Masani, Mat Yunus Abdul; Noll, Gundula A; Parveez, Ghulam Kadir Ahmad; Sambanthamurthi, Ravigadevi; Prüfer, Dirk

2014-01-01

Genetic engineering remains a major challenge in oil palm (Elaeis guineensis) because particle bombardment and Agrobacterium-mediated transformation are laborious and/or inefficient in this species, often producing chimeric plants and escapes. Protoplasts are beneficial as a starting material for genetic engineering because they are totipotent, and chimeras are avoided by regenerating transgenic plants from single cells. Novel approaches for the transformation of oil palm protoplasts could therefore offer a new and efficient strategy for the development of transgenic oil palm plants. We recently achieved the regeneration of healthy and fertile oil palms from protoplasts. Therefore, we focused on the development of a reliable PEG-mediated transformation protocol for oil palm protoplasts by establishing and validating optimal heat shock conditions, concentrations of DNA, PEG and magnesium chloride, and the transfection procedure. We also investigated the transformation of oil palm protoplasts by DNA microinjection and successfully regenerated transgenic microcalli expressing green fluorescent protein as a visible marker to determine the efficiency of transformation. We have established the first successful protocols for the transformation of oil palm protoplasts by PEG-mediated transfection and DNA microinjection. These novel protocols allow the rapid and efficient generation of non-chimeric transgenic callus and represent a significant milestone in the use of protoplasts as a starting material for the development of genetically-engineered oil palm plants.

Efficient Transformation of Oil Palm Protoplasts by PEG-Mediated Transfection and DNA Microinjection

PubMed Central

Masani, Mat Yunus Abdul; Noll, Gundula A.; Parveez, Ghulam Kadir Ahmad; Sambanthamurthi, Ravigadevi; Prüfer, Dirk

2014-01-01

Background Genetic engineering remains a major challenge in oil palm (Elaeis guineensis) because particle bombardment and Agrobacterium-mediated transformation are laborious and/or inefficient in this species, often producing chimeric plants and escapes. Protoplasts are beneficial as a starting material for genetic engineering because they are totipotent, and chimeras are avoided by regenerating transgenic plants from single cells. Novel approaches for the transformation of oil palm protoplasts could therefore offer a new and efficient strategy for the development of transgenic oil palm plants. Methodology/Principal Findings We recently achieved the regeneration of healthy and fertile oil palms from protoplasts. Therefore, we focused on the development of a reliable PEG-mediated transformation protocol for oil palm protoplasts by establishing and validating optimal heat shock conditions, concentrations of DNA, PEG and magnesium chloride, and the transfection procedure. We also investigated the transformation of oil palm protoplasts by DNA microinjection and successfully regenerated transgenic microcalli expressing green fluorescent protein as a visible marker to determine the efficiency of transformation. Conclusions/Significance We have established the first successful protocols for the transformation of oil palm protoplasts by PEG-mediated transfection and DNA microinjection. These novel protocols allow the rapid and efficient generation of non-chimeric transgenic callus and represent a significant milestone in the use of protoplasts as a starting material for the development of genetically-engineered oil palm plants. PMID:24821306

Towards high-throughput automated targeted femtosecond laser-based transfection of adherent cells

NASA Astrophysics Data System (ADS)

Antkowiak, Maciej; Torres-Mapa, Maria Leilani; Gunn-Moore, Frank; Dholakia, Kishan

2011-03-01

Femtosecond laser induced cell membrane poration has proven to be an attractive alternative to the classical methods of drug and gene delivery. It is a selective, sterile, non-contact technique that offers a highly localized operation, low toxicity and consistent performance. However, its broader application still requires the development of robust, high-throughput and user-friendly systems. We present a system capable of unassisted enhanced targeted optoinjection and phototransfection of adherent mammalian cells with a femtosecond laser. We demonstrate the advantages of a dynamic diffractive optical element, namely a spatial light modulator (SLM) for precise three dimensional positioning of the beam. It enables the implementation of a "point-and-shoot" system in which using the software interface a user simply points at the cell and a predefined sequence of precisely positioned doses can be applied. We show that irradiation in three axial positions alleviates the problem of exact beam positioning on the cell membrane and doubles the number of viably optoinjected cells when compared with a single dose. The presented system enables untargeted raster scan irradiation which provides transfection of adherent cells at the throughput of 1 cell per second.

Transfected Poly(I:C) Activates Different dsRNA Receptors, Leading to Apoptosis or Immunoadjuvant Response in Androgen-independent Prostate Cancer Cells*

PubMed Central

Palchetti, Sara; Starace, Donatella; De Cesaris, Paola; Filippini, Antonio; Ziparo, Elio; Riccioli, Anna

2015-01-01

Despite the effectiveness of surgery or radiation therapy for the treatment of early-stage prostate cancer (PCa), there is currently no effective strategy for late-stage disease. New therapeutic targets are emerging; in particular, dsRNA receptors Toll-like receptor 3 (TLR3) and cytosolic helicases expressed by cancer cells, once activated, exert a pro-apoptotic effect in different tumors. We previously demonstrated that the synthetic analog of dsRNA poly(I:C) induces apoptosis in the androgen-dependent PCa cell line LNCaP in a TLR3-dependent fashion, whereas only a weak apoptotic effect is observed in the more aggressive and androgen-independent PCa cells PC3 and DU145. In this paper, we characterize the receptors and the signaling pathways involved in the remarkable apoptosis induced by poly(I:C) transfected by Lipofectamine (in-poly(I:C)) compared with the 12-fold higher free poly(I:C) concentration in PC3 and DU145 cells. By using genetic inhibition of different poly(I:C) receptors, we demonstrate the crucial role of TLR3 and Src in in-poly(I:C)-induced apoptosis. Therefore, we show that the increased in-poly(I:C) apoptotic efficacy is due to a higher binding of endosomal TLR3. On the other hand, we show that in-poly(I:C) binding to cytosolic receptors MDA5 and RIG-I triggers IRF3-mediated signaling, leading uniquely to the up-regulation of IFN-β, which likely in turn induces increased TLR3, MDA5, and RIG-I proteins. In summary, in-poly(I:C) activates two distinct antitumor pathways in PC3 and DU145 cells: one mediated by the TLR3/Src/STAT1 axis, leading to apoptosis, and the other one mediated by MDA5/RIG-I/IRF3, leading to immunoadjuvant IFN-β expression. PMID:25568326

[The induction of neovascularization in chorioallantoic membrane of chicken embryos transfected by a recombinant plasmid containing human angiogenin gene].

PubMed

Avdeeva, S V; Khaĭdarova, N V; Logunov, D Iu; Neugodova, G L; Sevast'ianova, G A; Tarantul, V Z; Naroditskiĭ, B S

2003-01-01

A method was elaborated to evaluate the biological activity of expression products of gene in the plasmid vectors, which are crucial for the synthesis of growth factor of blood vessels. It was proven as possible that the chrioallantonic membrane (CAM) of chicken's embryos could be transfected by recombinant plasmids containing both the reporter and target genes. The efficiency of CAM transfection was assessed by a plasmid carrying the reporter gene of green fluorescent protein (GFP). Finally, it was demonstrated that, at an infiltration of the recombinant plasmid containing the human angiogenine gene, its expression products induce the neovascularization in the CAM cells of chicken's embryos and stimulate an accretion in vessels of the 1st, 2nd and 3d orders.

Pancreatic Cancer Cell Exosome-Mediated Macrophage Reprogramming and the Role of MicroRNAs 155 and 125b2 Transfection using Nanoparticle Delivery Systems

PubMed Central

Su, Mei-Ju; Aldawsari, Hibah; Amiji, Mansoor

2016-01-01

Exosomes are nano-sized endosome-derived small intraluminal vesicles, which are important facilitators of intercellular communication by transporting contents, such as protein, mRNA, and microRNAs, between neighboring cells, such as in the tumor microenvironment. The purpose of this study was to understand the mechanisms of exosomes-mediated cellular communication between human pancreatic cancer (Panc-1) cells and macrophages (J771.A1) using a Transwell co-culture system. Following characterization of exosome-mediated cellular communication and pro-tumoral baseline M2 macrophage polarization, the Panc-1 cells were transfected with microRNA-155 (miR-155) and microRNA-125b-2 (miR-125b2) expressing plasmid DNA using hyaluronic acid-poly(ethylene imine)/hyaluronic acid-poly(ethylene glycol) (HA-PEI/HA-PEG) self-assembling nanoparticle-based non-viral vectors. Our results show that upon successful transfection of Panc-1 cells, the exosome content was altered leading to differential communication and reprogramming of the J774.A1 cells to an M1 phenotype. Based on these results, genetic therapies targeted towards selective manipulation of tumor cell-derived exosome content may be very promising for cancer therapy. PMID:27443190

Intracellular metabolism of a 2'-O-methyl-stabilized ribozyme after uptake by DOTAP transfection or asfree ribozyme. A study by capillary electrophoresis.

PubMed Central

Prasmickaite, L; Hogset, A; Maelandsmo, G; Berg, K; Goodchild, J; Perkins, T; Fodstad, O; Hovig, E

1998-01-01

The uptake and cellular metabolism of a fluorescein-labelled synthetic ribozyme stabilized by 2'- O -methyl modification and a 3' inverted thymidine have been studied, employing capillary gel electrophoresis as a novel and efficient analytical method. After internalization by DOTAP transfection, electrophoretic peaks of intact ribozyme and different degradation products were easily resolved and the amount of intracellular intact ribozyme was quantified to >10(7) molecules/cell at the peak value after 4 h transfection. On further incubation the amount of intracellular intact ribozyme decreased due to both degradation and efflux from the cell. However, even after 48 h incubation there were still >10(6) intact ribozyme molecules/cell. Clear differences both in uptake and in metabolism were seen when comparing DOTAP transfection with the uptake of free ribozyme. Fluorescence microscopy studies indicated that the ribozyme was mainly localized in intracellular granules, probably not accessible to target mRNA. This implies that agents able to release the intact ribozyme from intracellular vesicles into the cytosol should have a considerable potential for increasing the biological effects of synthetic ribozymes. PMID:9722645

Local matrix metalloproteinase 2 gene knockdown in balloon-injured rabbit carotid arteries using nonviral-small interfering RNA transfection.

PubMed

Hlawaty, Hanna; San Juan, Aurélie; Jacob, Marie-Paule; Vranckx, Roger; Letourneur, Didier; Feldman, Laurent J

2009-01-01

Small interfering RNA (siRNA) delivery is a promising approach for the treatment of cardiovascular diseases. Matrix metalloproteinase (MMP) 2 over-expression in the arterial wall has been implicated in restenosis after percutaneous coronary intervention, as well as in spontaneous atherosclerotic plaque rupture. We hypothesized that in vivo local delivery of siRNA targeted at MMP2 (MMP2-siRNA) in the balloon-injured carotid artery of hypercholesterolemic rabbits may lead to inhibition of MMP2 expression. Two weeks after balloon injury, 5 micromol/l of Tamra-tagged MMP2-siRNA, scramble siRNA or saline was locally injected in the carotid artery and incubated for 1 h. Fluorescent microscopy studies showed the circumferential uptake of siRNA in the superficial layers of neointimal cells. MMP2 mRNA levels, measured by the real-time reverse transcriptase-polymerase chain reaction, was decreased by 79 +/- 25% in MMP2-siRNA- versus scramble siRNA-transfected arteries (p < 0.05). MMP2 activity, measured by gelatin zymography performed on the conditioned media of MMP2-siRNA versus scramble siRNA transfected arteries, decreased by 53 +/- 29%, 50 +/- 24% and 46 +/- 14% at 24, 48 and 72 h, respectively (p < 0.005 for all). No effect was observed on MMP9, pro-MMP9 and TIMP-2 levels. The results obtained in the present study suggest that significant inhibition of gene expression can be achieved with local delivery of siRNA in the arterial wall in vivo. (c) 2008 John Wiley & Sons, Ltd.

Deterministic transfection drives efficient nonviral reprogramming and uncovers reprogramming barriers.

PubMed

Gallego-Perez, Daniel; Otero, Jose J; Czeisler, Catherine; Ma, Junyu; Ortiz, Cristina; Gygli, Patrick; Catacutan, Fay Patsy; Gokozan, Hamza Numan; Cowgill, Aaron; Sherwood, Thomas; Ghatak, Subhadip; Malkoc, Veysi; Zhao, Xi; Liao, Wei-Ching; Gnyawali, Surya; Wang, Xinmei; Adler, Andrew F; Leong, Kam; Wulff, Brian; Wilgus, Traci A; Askwith, Candice; Khanna, Savita; Rink, Cameron; Sen, Chandan K; Lee, L James

2016-02-01

Safety concerns and/or the stochastic nature of current transduction approaches have hampered nuclear reprogramming's clinical translation. We report a novel non-viral nanotechnology-based platform permitting deterministic large-scale transfection with single-cell resolution. The superior capabilities of our technology are demonstrated by modification of the well-established direct neuronal reprogramming paradigm using overexpression of the transcription factors Brn2, Ascl1, and Myt1l (BAM). Reprogramming efficiencies were comparable to viral methodologies (up to ~9-12%) without the constraints of capsid size and with the ability to control plasmid dosage, in addition to showing superior performance relative to existing non-viral methods. Furthermore, increased neuronal complexity could be tailored by varying BAM ratio and by including additional proneural genes to the BAM cocktail. Furthermore, high-throughput NEP allowed easy interrogation of the reprogramming process. We discovered that BAM-mediated reprogramming is regulated by AsclI dosage, the S-phase cyclin CCNA2, and that some induced neurons passed through a nestin-positive cell stage. In the field of regenerative medicine, the ability to direct cell fate by nuclear reprogramming is an important facet in terms of clinical application. In this article, the authors described their novel technique of cell reprogramming through overexpression of the transcription factors Brn2, Ascl1, and Myt1l (BAM) by in situ electroporation through nanochannels. This new technique could provide a platform for further future designs. Copyright © 2016 Elsevier Inc. All rights reserved.

Quantum dot-insect neuropeptide conjugates for fluorescence imaging, transfection, and nucleus targeting of living cells.

PubMed

Biju, Vasudevanpillai; Muraleedharan, Damodaran; Nakayama, Ken-ichi; Shinohara, Yasuo; Itoh, Tamitake; Baba, Yoshinobu; Ishikawa, Mitsuru

2007-09-25

We identified an insect neuropeptide, namely, allatostatin 1 from Drosophila melanogaster, that transfects living NIH 3T3 and A431 human epidermoid carcinoma cells and transports quantum dots (QDs) inside the cytoplasm and even the nucleus of the cells. QD-conjugated biomolecules are valuable resources for visualizing the structures and functions of biological systems both in vivo and in vitro. Here, we selected allatostatin 1, Ala-Pro-Ser-Gly-Ala-Gln-Arg-Leu-Tyr-Gly-Phe-Gly-Leu-NH2, conjugated to streptavidin-coated CdSe-ZnS QDs. This was followed by investigating the transfection of live mammalian cells with QD-allatostatin conjugates, the transport of QDs by allatostatin inside the nucleus, and the proliferation of cells in the presence of allatostatin. Also, on the basis of dose-dependent proliferation of cells in the presence of allatostatin we identified that allatostatin is not cytotoxic when applied at nanomolar levels. Considering the sequence similarity between the receptors of allatostatin in D. melanogaster and somatostatin/galanin in mammalian cells, we expected interactions and localization of allatostatin to somatostatin/galanin receptors on the membranes of 3T3 and A431 cells. However, with QD conjugation we identified that the peptide was delivered inside the cells and localized mainly to the cytoplasm, microtubules, and nucleus. These results indicate that allatostatin is a promising candidate for high-efficiency cell transfection and nucleus-specific cell labeling. Also, the transport property of allatostatin is promising with respect to label/drug/gene delivery and high contrast imaging of live cells and cell organelles. Another promising application of allatostatin is that the transport of QDs inside the nucleus would lift the limit of general photodynamic therapy to nucleus-specific photodynamic therapy, which is expected to be more efficient than photosensitization at the cell membrane or in the cytoplasm as a result of the short lifetime of

The postmitotic Saccharomyces cerevisiae after spaceflight showed higher viability

NASA Astrophysics Data System (ADS)

Yi, Zong-Chun; Li, Xiao-Fei; Wang, Yan; Wang, Jie; Sun, Yan; Zhuang, Feng-Yuan

2011-06-01

The budding yeast Saccharomyces cerevisiae has been proposed as an ideal model organism for clarifying the biological effects caused by spaceflight conditions. The postmitotic S. cerevisiae cells onboard Practice eight recoverable satellite were subjected to spaceflight for 15 days. After recovery, the viability, the glycogen content, the activities of carbohydrate metabolism enzymes, the DNA content and the lipid peroxidation level in yeast cells were analyzed. The viability of the postmitotic yeast cells after spaceflight showed a three-fold increase as compared with that of the ground control cells. Compared to the ground control cells, the lipid peroxidation level in the spaceflight yeast cells markedly decreased. The spaceflight yeast cells also showed an increase in G2/M cell population and a decrease in Sub-G1 cell population. The glycogen content and the activities of hexokinase and succinate dehydrogenase significantly decreased in the yeast cells after spaceflight. In contrast, the activity of malate dehydrogenase showed an obvious increase after spaceflight. These results suggested that microgravity or spaceflight could promote the survival of postmitotic S. cerevisiae cells through regulating carbohydrate metabolism, ROS level and cell cycle progression.

In vivo monitoring of transfected DNA, gene expression kinetics, and cellular immune responses in mice immunized with a human NIS gene-expressing plasmid.

PubMed

Son, Hye-Youn; Jeon, Yong-Hyun; Chung, June-Key; Kim, Chul-Woo

2016-12-01

In assessing the effectiveness of DNA vaccines, it is important to monitor: (1) the kinetics of target gene expression in vivo; and (2) the movement of cells that become transfected with the plasmid DNA used in the immunization of a subject. In this study, we used, as a visual imaging marker, expression of the transfected human sodium/iodide symporter (hNIS) gene, which enhances intracellular radio-pertechnetate (TcO4-) accumulation. After intradermal (i.d.) and systemic injection of mice with pcDNA-hNIS and radioactive Technetium-99m (Tc-99m), respectively, whole-body images were obtained by nuclear scintigraphy. The migration of mice cells transfected with the hNIS gene was monitored over a 2-week period by gamma-radioactivity counting of isolated cell populations and was demonstrated in peripheral lymphoid tissues, especially in the draining lymph nodes (dLNs). Beginning at 24 h after DNA inoculation and continuing for the 2-week monitoring period, hNIS-expressing cells were observed specifically in the T-cell-rich zones of the paracortical area of the dLNs. Over the same time period, high levels of INF-γ-secreting CD8 T-cells were found in the dLNs of the pcDNA-hNIS immunized mice. Tumor growth was also significantly retarded in the mice that received hNIS DNA immunization followed by inoculation with CT26 colorectal adenocarcinoma cells that had been transfected with the rat NIS gene (rNIS), which is 93% homologous to the hNIS gene. In conclusion, mouse cells transfected with hNIS DNA after i.d. immunization were found to traffic to the dLNs, and hNIS gene expression in these cells continued for at least 2 weeks post immunization. Furthermore, sequential presentation of NIS DNA to T-cells by migratory antigen presenting cells could induce NIS DNA-specific Th1 immune responses and thus retard the growth of NIS-expressing tumors. © The Author(s) 2016.

Genetically engineered cardiac pacemaker: Stem cells transfected with HCN2 gene and myocytes—A model

NASA Astrophysics Data System (ADS)

Kanani, S.; Pumir, A.; Krinsky, V.

2008-01-01

One of the successfully tested methods to design genetically engineered cardiac pacemaker cells consists in transfecting a human mesenchymal stem cell (hMSC) with a HCN2 gene and connecting it to a myocyte. We develop and study a mathematical model, describing a myocyte connected to a hMSC transfected with a HCN2 gene. The cardiac action potential is described both with the simple Beeler Reuter model, as well as with the elaborate dynamic Luo Rudy model. The HCN2 channel is described by fitting electrophysiological records, in the spirit of Hodgkin Huxley. The model shows that oscillations can occur in a pair myocyte-stem cell, that was not observed in the experiments yet. The model predicted that: (1) HCN pacemaker channels can induce oscillations only if the number of expressed I channels is low enough. At too high an expression level of I channels, oscillations cannot be induced, no matter how many pacemaker channels are expressed. (2) At low expression levels of I channels, a large domain of values in the parameter space (n, N) exists, where oscillations should be observed. We denote N the number of expressed pacemaker channels in the stem cell, and n the number of gap junction channels coupling the stem cell and the myocyte. (3) The expression levels of I channels observed in ventricular myocytes, both in the Beeler Reuter and in the dynamic Luo Rudy models are too high to allow to observe oscillations. With expression levels below ˜1/4 of the original value, oscillations can be observed. The main consequence of this work is that in order to obtain oscillations in an experiment with a myocyte-stem cell pair, increasing the values of n, N is unlikely to be helpful, unless the expression level of I has been reduced enough. The model also allows us to explore levels of gene expression not yet achieved in experiments, and could be useful to plan new experiments, aimed at improving the robustness of the oscillations.

Polymer nanoassemblies with hydrophobic pendant groups in the core induce false positive siRNA transfection in luciferase reporter assays.

PubMed

Rheiner, Steven; Reichel, Derek; Rychahou, Piotr; Izumi, Tadahide; Yang, Hsin-Sheng; Bae, Younsoo

2017-08-07

Poly(ethylene glycol)-conjugated polyethylenimine (PEG-PEI) is a widely studied cationic polymer used to develop non-viral vectors for siRNA therapy of genetic disorders including cancer. Cell lines stably expressing luciferase reporter protein typically evaluate the transfection efficacy of siRNA/PEG-PEI complexes, however recent findings revealed that PEG-PEI can reduce luciferase expression independent of siRNA. This study elucidates a cause of the false positive effect in luciferase assays by using polymer nanoassemblies (PNAs) made from PEG, PEI, poly-(l-lysine) (PLL), palmitate (PAL), and deoxycholate (DOC): PEG-PEI (2P), PEG-PEI-PAL (3P), PEG-PLL (2P'), PEG-PLL-PAL (3P'), and PEG-PEI-DOC (2PD). In vitro transfection and western blot assays of luciferase using a colorectal cancer cell line expressing luciferase (HT29/LUC) concluded that 2P and 2P' caused no luciferase expression reduction while hydrophobically modified PNAs induced a 35-50% reduction (3P'<2PD<3P). Although cell viability remained stagnant, 3P triggered cellular stress responses including increased membrane porosity and decreased ATP and cellular protein concentrations. Raman spectroscopy suggested that hydrophobic groups influence PNA conformation changes, which may have caused over-ubiquitination and degradation of luciferase in the cells. These results indicate that hydrophobically modified PEG-PEI induces cellular distress causing over-ubiquitination of the luciferase protein, producing false positive siRNA transfection in the luciferase assay. Copyright © 2017 Elsevier B.V. All rights reserved.

The M sub 1 muscarinic receptor and its second messenger coupling in human neuroblastoma cells and transfected murine fibroblast cells

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

Mei, Lin.

1989-01-01

The data of this study indicate that pirenzepine (PZ)-high affinity muscarinic receptors (mAChRs) are coupled to the hydrolysis of inositol lipids and not to the adenylate cyclase system in human neuroblastoma SH-SY5Y cells. The maximal carbachol(CCh)-stimulated ({sup 3}H)IP{sub 1} accumulation in the SH-SY5Y cells was decreased in the presence of 1{mu}g/ml pertussis toxin, suggesting that a pertussis toxin sensitive G-protein may be involved in the coupling. Several cell clones which express only M{sub 1} mAChR were generated by transfecting the murine fibroblast B82 cells with the cloned rat genomic m{sub 1} gene. The transfected B82 cells (cTB10) showed specific ({supmore » 3}H)(-)QNB binding activity. The mAChRs in these cells are of the M{sub 1} type defined by their high affinity for PZ and low affinity for AF-DX 116 and coupled to hydrolysis of inositol lipids, possibly via a pertussis toxin sensitive G protein. The relationship between the M{sub 1} mAChR density and the receptor-mediated hydrolysis of inositol lipids was studied in 7 clones. The M{sub 1} mAChR densities in these cells characterized by ({sup 3}H)(-)MQNB binding ranged from 12 fmol/10{sup 6} cells in LK3-1 cells to 260 fmol/10{sup 6} cells in the LK3-8 cells.« less

A systematic study of transfection efficiency and cytotoxicity in HeLa cells using iron oxide nanoparticles prepared with organic and inorganic bases.

PubMed

Calmon, Marilia Freitas; de Souza, Aryane Tofanello; Candido, Natalia Maria; Raposo, Maria Irene Bartolomeu; Taboga, Sebastião; Rahal, Paula; Nery, Jose G

2012-12-01

Magnetic iron oxide nanoparticles (magnetite) (MNPs) were prepared using different organic and inorganic bases. Strong inorganic base (KOH) and organic bases (NH(4)OH and 1,4-diazabicyclo[2.2.2]octane (DABCO)) were used in the syntheses of the MNPs. The MNPs were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR) and magnetization measurements. MNPs prepared with strong inorganic base yielded an average size of 100 nm, whereas the average size of the MNPs prepared with the organic bases was 150 nm. The main competitive phase for MNPs prepared with the strong inorganic and organic bases was maghemite; however, syntheses with KOH yielded a pure magnetite phase. The transfection study performed with the MNPs revealed that the highest transfection rate was obtained with the MNPs prepared with KOH (74%). The correlation between the magnetic parameters and the transfection ratio without transfection agents indicated that MNPs prepared with KOH were a better vector for possible applications of these MNPs in biomedicine. HeLa cells incubated with MNP-KOH at 10 μg/mL for 24 and 48 h exhibited a decrease in population in comparison with the control cells and it was presumably related to the toxicity of the MNPs. However, the cells incubated with MNP-KOH at 50 and 100 μg/mL presented a very small difference in the viability between the cell populations studied at 24 and 48 h. These data illustrate the viability of HeLa cells treated with MNP-KOH and suggest the potential use of these MNPs in biomedical applications. Copyright © 2012 Elsevier B.V. All rights reserved.

Fibroblasts maintained in 3 dimensions show a better differentiation state and higher sensitivity to estrogens

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

Montani, Claudia; Steimberg, Nathalie; Boniotti, Jennifer

2014-11-01

Cell differentiation and response to hormonal signals were studied in a 3D environment on an in-house generated mouse fibroblast cell line expressing a reporter gene under the control of estrogen responsive sequences (EREs). 3D cell culture conditions were obtained in a Rotary Cell Culture System; (RCCS™), a microgravity based bioreactor that promotes the aggregation of cells into multicellular spheroids (MCS). In this bioreactor the cells maintained a better differentiated phenotype and more closely resembled in vivo tissue. The RCCS™ cultured fibroblasts showed higher expression of genes regulating cell assembly, differentiation and hormonal functions. Microarray analysis showed that genes related tomore » cell cycle, proliferation, cytoskeleton, migration, adhesion and motility were all down-regulated in 3D as compared to 2D conditions, as well as oncogene expression and inflammatory cytokines. Controlled remodeling of ECM, which is an essential aspect of cell organization, homeostasis and tissue was affected by the culture method as assessed by immunolocalization of β-tubulin. Markers of cell organization, homeostasis and tissue repair, metalloproteinase 2 (MMP2) and its physiological inhibitor (TIMP4) changed expression in association with the relative formation of cell aggregates. The fibroblasts cultured in the RCCS™ maintain a better responsiveness to estrogens, measured as expression of ERα and regulation of an ERE-dependent reporter and of the endogenous target genes CBP, Rarb, MMP1 and Dbp. Our data highlight the interest of this 3D culture model for its potential application in the field of cell response to hormonal signals and the pharmaco-toxicological analyses of chemicals and natural molecules endowed of estrogenic potential. - Highlights: • We here characterized the first cell line derived from an estrogen reporter mouse. • In the RCCS cells express an immortalized behavior but not a transformed phenotype. • The RCCS provides a

[Experimental study of human umbilical cord blood derived stromal cells transfected with recombinant adenoviral vector co-expressing VCAM-1 and GFP].

PubMed

Zhang, Xi; Si, Ying-Jian; Chen, Xing-Hua; Liu, Yao; Gao, Li; Gao, Lei; Peng, Xian-Gui; Wang, Qing-Yu

2008-06-01

This study was aimed to investigate the effect of vcam-1 gene-modified human umbilical cord blood derived stromal cells (CBDSCs) on hematopoietic regulation so as to establish the experimental foundation for further study. The target gene vcam-1 was cloned into the shuttle plasmid with the report gene GFP. The recombinant shuttle plasmid was transformed into BJ5183 bacteria to recombine with backbone vector pAdeasy-l, and the recombinant adenoviral vector ad-vcam-1-gfp was confirmed after transfection with CBDSCs. The results indicated that two fragments of about 9 kb and 2 kb were obtained after digestion of recombinant plasmid pAdTrack-vcam-1 with NotIand XhoI, and single fragment of 600 bp was obtained after amplification with PCR; two fragments of about 31 kb and 4 kb were obtained after digestion of recombinant plasmid pad-vcam-1-gfp with PacI, which suggested a successful homologous recombination. The expression of vcam-1 gene in ad-vcam-1-gfp transfected CBDSCs could be detected by immunocytochemistry, RT-PCR and fluorescent microscopy. It is concluded that the recombinant adenoviral vector ad-vcam-1-gfp has been constructed successfully, and the expression of vcam-1 is up-regulated in CBDSCs transfected by gene ad-vcam-1-gfp.

Cholesterol-based cationic lipids for gene delivery: contribution of molecular structure factors to physico-chemical and biological properties.

PubMed

Sheng, Ruilong; Luo, Ting; Li, Hui; Sun, Jingjing; Wang, Zhao; Cao, Amin

2014-04-01

In this work, we prepared a series of cholesterol-based cationic (Cho-cat) lipids bearing cholesterol hydrophobe, natural amino acid headgroups (lysine/histidine) and linkage (carbonate ester/ether) bonds. In which, the natural amino acid headgroups made dominant contribution to their physico-chemical and biological properties. Among the lipids, the l-lysine headgroup bearing lipids (Cho-es/et-Lys) showed higher pDNA binding affinity and were able to form larger sized and higher surface charged lipoplexes than that of l-histidine headgroup bearing lipids (Cho-es/et-His), they also demonstrated higher transfection efficacy and higher membrane disruption capacities than that of their l-histidine headgroup bearing counterparts. However, compared to the contributions of the headgroups, the (carbonate ester/ether) linkage bonds showed much less affects. Besides, it could be noted that, Cho-es/et-Lys lipids exhibited very high luciferase gene transfection efficiency that almost reached the transfection level of "gold standard" bPEI-25k, made them potential transfection reagents for practical application. Moreover, the results facilitated the understanding for the structure-activity relationship of the cholesterol-based cationic lipids, and also paved a simple and efficient way for achieving high transfection efficiency by modification of suitable headgroups on lipid gene carriers. Copyright © 2014 Elsevier B.V. All rights reserved.

Chemical Oxidation of a Redox-Active, Ferrocene-Containing Cationic Lipid: Influence on Interactions with DNA and Characterization in the Context of Cell Transfection

PubMed Central

Aytar, Burcu S.; Muller, John P. E.; Golan, Sharon; Kondo, Yukishige; Talmon, Yeshayahu; Abbott, Nicholas L.; Lynn, David M.

2012-01-01

We report an approach to the chemical oxidation of a ferrocene-containing cationic lipid [bis(11-ferrocenylundecyl)dimethylammonium bromide, BFDMA] that provides redox-based control over the delivery of DNA to cells. We demonstrate that BFDMA can be oxidized rapidly and quantitatively by treatment with Fe(III)sulfate. This chemical approach, while offering practical advantages compared to electrochemical methods used in past studies, was found to yield BFDMA/DNA lipoplexes that behave differently in the context of cell transfection from lipoplexes formed using electrochemically oxidized BFDMA. Specifically, while lipoplexes of the latter do not transfect cells efficiently, lipoplexes of chemically oxidized BFDMA promoted high levels of transgene expression (similar to levels promoted by reduced BFDMA). Characterization by SANS and cryo-TEM revealed lipoplexes of chemically and electrochemically oxidized BFDMA to both have amorphous nanostructures, but these lipoplexes differed significantly in size and zeta potential. Our results suggest that differences in zeta potential arise from the presence of residual Fe2+ and Fe3+ ions in samples of chemically oxidized BFDMA. Addition of the iron chelating agent EDTA to solutions of chemically oxidized BFDMA produced samples functionally similar to electrochemically oxidized BFDMA. These EDTA-treated samples could also be chemically reduced by treatment with ascorbic acid to produce samples of reduced BFDMA that do promote transfection. Our results demonstrate that entirely chemical approaches to oxidation and reduction can be used to achieve redox-based ‘on/off’ control of cell transfection similar to that achieved using electrochemical methods. PMID:22980739

An Efficient Method for High-Fidelity BAC/PAC Retrofitting with a Selectable Marker for Mammalian Cell Transfection

PubMed Central

Wang, Zunde; Engler, Peter; Longacre, Angelika; Storb, Ursula

2001-01-01

Large-scale genomic sequencing projects have provided DNA sequence information for many genes, but the biological functions for most of them will only be known through functional studies. Bacterial artificial chromosomes (BACs) and P1-derived artificial chromosomes (PACs) are large genomic clones stably maintained in bacteria and are very important in functional studies through transfection because of their large size and stability. Because most BAC or PAC vectors do not have a mammalian selection marker, transfecting mammalian cells with genes cloned in BACs or PACs requires the insertion into the BAC/PAC of a mammalian selectable marker. However, currently available procedures are not satisfactory in efficiency and fidelity. We describe a very simple and efficient procedure that allows one to retrofit dozens of BACs in a day with no detectable deletions or unwanted recombination. We use a BAC/PAC retrofitting vector that, on transformation into competent BAC or PAC strains, will catalyze the specific insertion of itself into BAC/PAC vectors through in vivo cre/loxP site-specific recombination. PMID:11156622

Biodegradable charged polyester-based vectors (BCPVs) as an efficient non-viral transfection nanoagent for gene knockdown of the BCR-ABL hybrid oncogene in a human chronic myeloid leukemia cell line

NASA Astrophysics Data System (ADS)

Yang, Chengbin; Panwar, Nishtha; Wang, Yucheng; Zhang, Butian; Liu, Maixian; Toh, Huiting; Yoon, Ho Sup; Tjin, Swee Chuan; Chong, Peter Han Joo; Law, Wing-Cheung; Chen, Chih-Kuang; Yong, Ken-Tye

2016-04-01

First-line therapy of chronic myelogenous leukemia (CML) has always involved the use of BCR-ABL tyrosine-kinase inhibitors which is associated with an abnormal chromosome called Philadelphia chromosome. Although the overall survival rate has been improved by the current therapeutic regime, the presence of resistance has resulted in limited efficacy. In this study, an RNA interference (RNAi)-based therapeutic regime is proposed with the aim to knockdown the BCR-ABL hybrid oncogene using small interfering RNA (siRNA). The siRNA transfection rates have usually been limited due to the declining contact probability among polyplexes and the non-adherent nature of leukemic cells. Our work aims at addressing this limitation by using a biodegradable charged polyester-based vector (BCPV) as a nanocarrier for the delivery of BCR-ABL-specific siRNA to the suspension culture of a K562 CML cell line. BCR-ABL siRNAs were encapsulated in the BCPVs by electrostatic force. Cell internalization was facilitated by the BCPV and assessed by confocal microscopy and flow cytometry. The regulation of the BCR-ABL level in K562 cells as a result of RNAi was analyzed by real-time polymerase chain reaction (RT-PCR). We observed that BCPV was able to form stable nanoplexes with siRNA molecules, even in the presence of fetal bovine serum (FBS), and successfully assisted in vitro siRNA transfection in the non-adherent K562 cells. As a consequence of downregulation of BCR-ABL, BCPV-siRNA nanoplexes inhibited cell proliferation and promoted cell apoptosis. All results were compared with a commercial transfection reagent, Lipofectamine2000™, which served as a positive control. More importantly, this class of non-viral vector exhibits biodegradable features and negligible cytotoxicity, thus providing a versatile platform to deliver siRNA to non-adherent leukemia cells with high transfection efficiency by effectively overcoming extra- and intra-cellular barriers. Due to the excellent in vitro

Markedly Enhanced Skeletal Muscle Transfection Achieved by the Ultrasound-Targeted Delivery of Non-Viral Gene Nanocarriers with Microbubbles

PubMed Central

Burke, Caitlin W.; Suk, Jung Soo; Kim, Anthony J.; Hsiang, Yu-Han J.; Klibanov, Alexander L.; Hanes, Justin; Price, Richard J.

2012-01-01

Our goal was to enhance ultrasound (US)-targeted skeletal muscle transfection through the use of poly(ethyleneglycol) (PEG)/polyethylenimine (PEI) nanocomplex gene carriers and adjustments to US and microbubble (MB) parameters. C57BL/6 mice received an intravenous infusion of MBs and either “naked” luciferase plasmid or luciferase plasmid condensed in PEG/PEI nanocomplexes. Pulsed ultrasound (1MHz; 0.6 MPa or 0.8 MPa) was applied to the right hindlimb for 12 mins. Luciferase activity in both hindlimbs was assessed at 3, 5, 7, and 10 days post-treatment by bioluminescent imaging. When targeted to hindlimb using unsorted MBs and 0.6 MPa US, 7 days after treatment, we observed a >60-fold increase in luciferase activity in PEG/PEI nanocomplex treated muscles over muscles treated with “naked” plasmid DNA. Luciferase activity was consistently greater after treatment with PEG/PEI nanocomplexes at 0.6 MPa as compared to 0.8 MPa. The combination of small diameter MBs and 0.6 MPa US also resulted in significantly greater gene expression when compared to concentration matched intramuscular injections, a control condition in which considerably more PEG/PEI nanocomplexes were present in tissue. This result suggests that, in addition to facilitating PEG/PEI nanocomplex delivery from the bloodstream to tissue, US enhances transfection via one or more secondary mechanisms, including increased cellular uptake and/or trafficking to the nucleus of PEG/PEI nanocomplexes. We conclude that PEG/PEI nanocomplexes may be used to markedly enhance the amplitude of US-MB-targeted skeletal muscle transfection and that activating “small” MBs with a moderate level (0.6 MPa) of acoustic pressure can further enhance these effects. PMID:22800583

Activation of Estrogen Receptor Transfected into a Receptor-Negative Brest Cancer Cell Line Decreases the Metastatic and Invasive Potential of the Cells

NASA Astrophysics Data System (ADS)

Garcia, Marcel; Derocq, Danielle; Freiss, Gilles; Rochefort, Henri

1992-12-01

Breast cancers containing estrogen receptors are responsive to antiestrogen treatment and have a better prognosis than estrogen receptor-negative tumors. The loss of estrogen and progesterone receptors appears to be associated with a progression to less-differentiated tumors. We transfected the human estrogen receptor into the estrogen receptor-negative metastatic breast cancer cell line MDA-MB-231 in an attempt to restore their sensitivity to antiestrogens. Two stable sublines of MDA-MB-231 cells (HC1 and HE5) expressing functional estrogen receptors were studied for their ability to grow and invade in vitro and to metastasize in athymic nude mice. The number and size of lung metastases developed by these two sublines in ovariectomized nude mice was not markedly altered by tamoxifen but was inhibited 3-fold by estradiol. Estradiol also significantly inhibited in vitro cell proliferation of these sublines and their invasiveness in Matrigel, a reconstituted basement membrane, whereas the antiestrogens 4-hydroxytamoxifen and ICI 164,384 reversed these effects. These results show that estradiol inhibits the metastatic ability of estrogen receptornegative breast cancer cells following transfection with the estrogen receptor, whereas estrogen receptor-positive breast cancers are stimulated by estrogen, indicating that factors other than the estrogen receptor are involved in progression toward hormone independence. Reactivation or transfer of the estrogen receptor gene can therefore be considered as therapeutic approaches to hormone-independent cancers

Ligand-induced adhesion to activated endothelium and to vascular cell adhesion molecule-1 in lymphocytes transfected with the N-formyl peptide receptor.

PubMed

Honda, S; Campbell, J J; Andrew, D P; Engelhardt, B; Butcher, B A; Warnock, R A; Ye, R D; Butcher, E C

1994-04-15

Binding of FMLP to the neutrophil N-formyl peptide receptor (FPR) transmits signals through pertussis toxin-sensitive G proteins triggering Ca2+ flux, superoxide production, granule exocytosis, and neutrophil aggregation and adhesion involving the beta 2 (CD18) integrins. Expression of the FPR in mouse fibroblasts or human kidney cells has been shown to confer an N-formyl peptide-inducible Ca2+ flux in transfectants. Here we demonstrate that the transfected receptor can also support ligand-induced alterations in cellular adhesion. We established stable transfectants of mouse L1-2 pre-B cells with cDNA for human FPR (L1-2 FPR cells). The transfectants bind N-formyl-Nle-Leu-Phe-Nle-Tyr-Lys-fluorescein with 1.4 x 10(5) sites per cell and a dissociation constant of 3.3 nM. Stimulation with FMLP induces a transient Ca2+ flux. FMLP also triggers adhesion of L1-2 FPR cells to TNF-alpha- or LPS-activated bEnd3 cells (mouse brain-derived endothelial cells) and to purified mouse VCAM-1. Binding is inhibited by Abs to VCAM-1 and to the alpha-chain of its lymphocyte receptor (the alpha 4 beta 1 integrin, VLA-4). Stimulation with FMLP does not induce a change in cell surface expression of alpha 4. Induced adhesion to VCAM-1 is rapid, detectable at the earliest times measurable (30 to 60 s after FMLP addition), and is inhibited by pertussis toxin. We conclude that FPR can mediate integrin activation not only in neutrophils but also in lymphocytes, and can trigger rapid adhesion via lymphocyte alpha 4 beta 1. The adhesion of lymphocytes is critical to their migration and targeting; our results suggest the possibility of manipulating adhesive responses through expression of chemoattractant receptors in lymphoid cells engineered for cellular therapy, allowing targeted adhesion and potentially migration in response to locally administered ligands.

Dentin barrier test with transfected bovine pulp-derived cells.

PubMed

Schmalz, G; Schuster, U; Thonemann, B; Barth, M; Esterbauer, S

2001-02-01

Growth kinetics of SV40 large T-antigen-transfected bovine pulp-derived cells on dentin were investigated. These cells were used in a dentin barrier test device, and the system was evaluated by testing a set of dental filling materials. Cells (120 cells/mm2) were seeded on dentin slices and incubated for up to 21 days. Cell proliferation was recorded using MTT assay. For cytotoxicity tests 3500 cells/mm2 were seeded on dentin discs, which were then incorporated into the dentin barrier test device. After 72 h preincubation test materials were applied. After a 24 h exposure with or without perfusion of the pulpal part of the test device, cell survival was evaluated using MTT assay. The cells revealed similar growth kinetics on dentin slices and on tissue culture plates. In cytotoxicity tests the cells were more sensitive toward the test materials than previously used three-dimensional cultures of human foreskin fibroblasts and as anticipated from clinical experience. Further improvement is expected by using three-dimensional cultures of pulp-derived cells.

Enhancement of efficiency of chitosan-based complexes for gene transfection with poly(γ-glutamic acid) by augmenting their cellular uptake and intracellular unpackage.

PubMed

Liao, Zi-Xian; Peng, Shu-Fen; Chiu, Ya-Ling; Hsiao, Chun-Wen; Liu, Hung-Yi; Lim, Woon-Hui; Lu, Hsiang-Ming; Sung, Hsing-Wen

2014-11-10

As a cationic polysaccharide, chitosan (CS) has been identified for its potential use as a non-viral vector for exogenous gene transfection. However, owing to their electrostatic interactions, CS complexes may cause difficulties in gene release upon their arrival at the site of action, thus limiting their transfection efficiency. In this work, an attempt is made to facilitate the release of a gene by incorporating a negatively-charged poly(γ-glutamic acid) (γPGA) into CS complexes in order to diminish their attractive interactions. The mechanisms of exploiting γPGA to enhance the transfection efficiency of CS complexes are elucidated. The feasibility of using this CS/γPGA-based system for DNA or siRNA transfer is explored as well. Additionally, potential of the CS/γPGA formulation to deliver disulfide bond-conjugated dual PEGylated siRNAs for multiple gene silencing is also examined. Moreover, the genetic use of pKillerRed-mem, delivered using complexes of CS and γPGA, to express a membrane-targeted KillerRed as an intrinsically generated photosensitizer for photodynamic therapy is described. Copyright © 2014 Elsevier B.V. All rights reserved.

[Construction and identification of recombinant human platelet-derived growth factor-B adenoviral vector and transfection into periodontal ligament stem cells].

PubMed

Shang, Shu-huan; Zhang, Yu-feng; Shi, Bin; Cheng, Xiang-rong

2008-10-01

To construct a recombinant human platelet-derived growth factor-B (PDGF-B) adenoviral vector and to transfect it into human periodontal ligament stem cells (PDLSC). The recombinant plasmid pAd-PDGF-B was constructed by homologous recombination and confirmed by restriction endonucleases digestion. Recombinant adenovirus was packaged in HEK293 cells. PDLSC were transfected with recombinant adenovirus and PDGF-B expression was confirmed. Expression of collagen type I gene was determined by quantitative analysis of the products of RT-PCR. The cell proliferation was determined with MTT colorimetric assay. The recombinant plasmid pAd-PDGF-B was confirmed by restriction endonucleases digestion. EGFP expression was observed on the third day after transfecting, and the expression of PDGF-B was detected. Immunohistochemical methods revealed that PDGF-B was expressed in PDLSC. Levels of expression of collagen type I gene were increased significantly by transfer of the exogenous PDGF-B gene to PDLSC. At the same time, findings indicated that Ad-PDGF-B stimulated PDLSC proliferation. MTT assay indicated the absorbance of PDLSC by stimulating with Ad-PDGF-B was (0.68 +/- 0.02), P < 0.01. Using the AdEasy system, the human PDGF-B recombinant adenovirus can be rapidly obtained. These results indicate that recombinant adenoviruses encoding PDGF-B transgenes could modulate proliferative activity of PDLSC, enhance the high expression of collagen type I and lay the foundation for periodontal tissue regeneration and dental implant gene therapy.

Alterations of DNA content in human endometrial stromal cells transfected with a temperature-sensitive SV40: tetraploidization and physiological consequences.

PubMed

Rinehart, C A; Mayben, J P; Butler, T D; Haskill, J S; Kaufman, D G

1992-01-01

The normal genomic stability of human cells is reversed during neoplastic transformation. The SV40 large T antigen alters the DNA content in human endometrial stromal cells in a manner that relates to neoplastic progression. Human endometrial stromal cells were transfected with a plasmid containing the A209 temperature-sensitive mutant of SV40 (tsSV40), which is also defective in the viral origin of replication. Ninety-seven clonal transfectants from seven different primary cell strains were isolated. Initial analysis revealed that 20% of the clonal populations (19/97) had an apparent diploid DNA content, 35% (34/97) had an apparent tetraploid DNA content, and the remainder were mixed populations of diploid and tetraploid cells. No aneuploid populations were observed. Diploid tsSV40 transformed cells always give rise to a population of cells with a tetraploid DNA content when continuously cultured at the permissive temperature. The doubling of DNA content can be vastly accelerated by the sudden reintroduction of large T antigen activity following a shift from non-permissive to permissive temperature. Tetraploid tsSV40 transfected cells have a lower capacity for anchorage-independent growth and earlier entry into 'crisis' than diploid cells. These results indicate that during the pre-crisis, extended lifespan phase of growth, the SV40 large T antigen causes a doubling of DNA content. This apparent doubling of DNA content does not confer growth advantage during the extended lifespan that precedes 'crisis'.

Encapsulation of adenovirus serotype 5 in anionic lecithin liposomes using a bead-based immunoprecipitation technique enhances transfection efficiency.

PubMed

Mendez, Natalie; Herrera, Vanessa; Zhang, Lingzhi; Hedjran, Farah; Feuer, Ralph; Blair, Sarah L; Trogler, William C; Reid, Tony R; Kummel, Andrew C

2014-11-01

Oncolytic viruses (OVs) constitute a promising class of cancer therapeutics which exploit validated genetic pathways known to be deregulated in many cancers. To overcome an immune response and to enhance its potential use to treat primary and metastatic tumors, a method for liposomal encapsulation of adenovirus has been developed. The encapsulation of adenovirus in non-toxic anionic lecithin-cholesterol-PEG liposomes ranging from 140 to 180 nm in diameter have been prepared by self-assembly around the viral capsid. The encapsulated viruses retain their ability to infect cancer cells. Furthermore, an immunoprecipitation (IP) technique has shown to be a fast and effective method to extract non-encapsulated viruses and homogenize the liposomes remaining in solution. 78% of adenovirus plaque forming units were encapsulated and retained infectivity after IP processing. Additionally, encapsulated viruses have shown enhanced transfection efficiency up to 4 × higher compared to non-encapsulated Ads. Extracting non-encapsulated viruses from solution may prevent an adverse in vivo immune response and may enhance treatment for multiple administrations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Encapsulation of Adenovirus Serotype 5 in Anionic Lecithin Liposomes using a Bead-Based Immunoprecipitation Technique Enhances Transfection Efficiency

PubMed Central

Mendez, N.; Herrera, V.; Zhang, L.; Hedjran, F.; Feuer, R.; Blair, S.; Trogler, W.; Reid, T.

2014-01-01

Oncolytic viruses (OVs) constitute a promising class of cancer therapeutics which exploit validated genetic pathways known to be deregulated in many cancers. To overcome an immune response and to enhance its potential use to treat primary and metastatic tumors, a method for liposomal encapsulation of adenovirus has been developed. The encapsulation of adenovirus in non-toxic anionic lecithin-cholesterol-PEG liposomes ranging from 140–180nm in diameter have been prepared by self-assembly around the viral capsid. The encapsulated viruses retain their ability to infect cancer cells. Furthermore, an immunoprecipitation (IP) technique has shown to be a fast and effective method to extract non-encapsulated viruses and homogenize the liposomes remaining in solution. 78% of adenovirus plaque forming units were encapsulated and retained infectivity after IP processing. Additionally, encapsulated viruses have shown enhanced transfection efficiency up to 4× higher compared to non-encapsulated Ads. Extracting non-encapsulated viruses from solution may prevent an adverse in vivo immune response and may enhance treatment for multiple administrations. PMID:25154663

Block of Inactivation-deficient Na+ Channels by Local Anesthetics in Stably Transfected Mammalian Cells

PubMed Central

Wang, Sho-Ya; Mitchell, Jane; Moczydlowski, Edward; Wang, Ging Kuo

2004-01-01

According to the classic modulated receptor hypothesis, local anesthetics (LAs) such as benzocaine and lidocaine bind preferentially to fast-inactivated Na+ channels with higher affinities. However, an alternative view suggests that activation of Na+ channels plays a crucial role in promoting high-affinity LA binding and that fast inactivation per se is not a prerequisite for LA preferential binding. We investigated the role of activation in LA action in inactivation-deficient rat muscle Na+ channels (rNav1.4-L435W/L437C/A438W) expressed in stably transfected Hek293 cells. The 50% inhibitory concentrations (IC50) for the open-channel block at +30 mV by lidocaine and benzocaine were 20.9 ± 3.3 μM (n = 5) and 81.7 ± 10.6 μM (n = 5), respectively; both were comparable to inactivated-channel affinities. In comparison, IC50 values for resting-channel block at −140 mV were >12-fold higher than those for open-channel block. With 300 μM benzocaine, rapid time-dependent block (τ ≈ 0.8 ms) of inactivation-deficient Na+ currents occurred at +30 mV, but such a rapid time-dependent block was not evident at −30 mV. The peak current at −30 mV, however, was reduced more severely than that at +30 mV. This phenomenon suggested that the LA block of intermediate closed states took place notably when channel activation was slow. Such closed-channel block also readily accounted for the LA-induced hyperpolarizing shift in the conventional steady-state inactivation measurement. Our data together illustrate that the Na+ channel activation pathway, including most, if not all, transient intermediate closed states and the final open state, promotes high-affinity LA binding. PMID:15545401

Nonviral RNA transfection to transiently modify T cells with chimeric antigen receptors for adoptive therapy.

PubMed

Riet, Tobias; Holzinger, Astrid; Dörrie, Jan; Schaft, Niels; Schuler, Gerold; Abken, Hinrich

2013-01-01

Redirecting T cells with a chimeric antigen receptor (CAR) of predefined specificity showed remarkable efficacy in the adoptive therapy trials of malignant diseases. The CAR consists of a single chain fragment of variable region (scFv) antibody targeting domain covalently linked to the CD3ζ signalling domain of the T cell receptor complex to mediate T cell activation upon antigen engagement. By using an antibody-derived targeting domain a CAR can potentially redirect T cells towards any target expressed on the cell surface as long as a binding domain is available. Antibody-mediated targeting moreover circumvents MHC restriction of the targeted antigen, thereby broadening the potential of applicability of adoptive T cell therapy. While T cells were so far genetically modified by viral transduction, transient modification with a CAR by RNA transfection gained increasing interest during the last years. This chapter focuses on methods to modify human T cells from peripheral blood with a CAR by electroporation of in vitro transcribed RNA and to test modified T cells for function for use in adoptive immunotherapy.

Physicochemical properties of polymers: An important system to overcome the cell barriers in gene transfection.

PubMed

Namvar, Ali; Bolhassani, Azam; Khairkhah, Niloofardokht; Motevalli, Fatemeh

2015-07-01

Delivery of the macromolecules including DNA, miRNA, and antisense oligonucleotides is typically mediated by carriers due to the large size and negative charge. Different physical (e.g., gene gun or electroporation), and chemical (e.g., cationic polymer or lipid) vectors have been already used to improve the efficiency of gene transfer. Polymer-based DNA delivery systems have attracted special interest, in particular via intravenous injection with many intra- and extracellular barriers. The recent progress has shown that stimuli-responsive polymers entitled as multifunctional nucleic acid vehicles can act to target specific cells. These nonviral carriers are classified by the type of stimulus including reduction potential, pH, and temperature. Generally, the physicochemical characterization of DNA-polymer complexes is critical to enhance the transfection potency via protection of DNA from nuclease digestion, endosomal escape, and nuclear localization. The successful clinical applications will depend on an exact insight of barriers in gene delivery and development of carriers overcoming these barriers. Consequently, improvement of novel cationic polymers with low toxicity and effective for biomedical use has attracted a great attention in gene therapy. This article summarizes the main physicochemical and biological properties of polyplexes describing their gene transfection behavior, in vitro and in vivo. In this line, the relative efficiencies of various cationic polymers are compared. © 2015 Wiley Periodicals, Inc.

The drug target genes show higher evolutionary conservation than non-target genes.

PubMed

Lv, Wenhua; Xu, Yongdeng; Guo, Yiying; Yu, Ziqi; Feng, Guanglong; Liu, Panpan; Luan, Meiwei; Zhu, Hongjie; Liu, Guiyou; Zhang, Mingming; Lv, Hongchao; Duan, Lian; Shang, Zhenwei; Li, Jin; Jiang, Yongshuai; Zhang, Ruijie

2016-01-26

Although evidence indicates that drug target genes share some common evolutionary features, there have been few studies analyzing evolutionary features of drug targets from an overall level. Therefore, we conducted an analysis which aimed to investigate the evolutionary characteristics of drug target genes. We compared the evolutionary conservation between human drug target genes and non-target genes by combining both the evolutionary features and network topological properties in human protein-protein interaction network. The evolution rate, conservation score and the percentage of orthologous genes of 21 species were included in our study. Meanwhile, four topological features including the average shortest path length, betweenness centrality, clustering coefficient and degree were considered for comparison analysis. Then we got four results as following: compared with non-drug target genes, 1) drug target genes had lower evolutionary rates; 2) drug target genes had higher conservation scores; 3) drug target genes had higher percentages of orthologous genes and 4) drug target genes had a tighter network structure including higher degrees, betweenness centrality, clustering coefficients and lower average shortest path lengths. These results demonstrate that drug target genes are more evolutionarily conserved than non-drug target genes. We hope that our study will provide valuable information for other researchers who are interested in evolutionary conservation of drug targets.

One pyrimidine dimer inactivates expression of a transfected gene in xeroderma pigmentosum cells

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

Protic-Sabljic, M.; Kraemer, K.H.

1985-10-01

The authors have developed a host cell reactivation assay of DNA repair utilizing UV-treated plasmid vectors. The assay primarily reflects cellular repair of transcriptional activity of damaged DNA measured indirectly as enzyme activity of the transfected genes. They studied three plasmids (pSV2cat, 5020 base pairs; pSV2catSVgpt, 7268 base pairs; and pRSVcat, 5027 base pairs) with different sizes and promoters carrying the bacterial cat gene (CAT, chloramphenicol acetyltransferase) in a construction that permits cat expression in human cells. All human simian virus 40-transformed cells studied expressed high levels of the transfected cat gene. UV treatment of the plasmids prior to transfectionmore » resulted in differential decrease in CAT activity in different cell lines. With pSV2catSVgpt, UV inactivation of CAT expression was greater in the xeroderma pigmentosum group A and D lines than in the other human cell lines tested. The D0 of the CAT inactivation curve was 50 J X m-2 for pSV2cat and for pRSVcat in the xeroderma pigmentosum group A cells. The similarity of the D0 data in the xeroderma pigmentosum group A cells for three plasmids of different size and promoters implies they all have similar UV-inactivation target size. UV-induced pyrimidine dimer formation in the plasmids was quantified by assay of the number of UV-induced T4 endonuclease V-sensitive sites. In the most sensitive xeroderma pigmentosum cells, with all three plasmids, one UV-induced pyrimidine dimer inactivates a target of about 2 kilobases, close to the size of the putative CAT mRNA.« less

Giardia canis: ultrastructural analysis of G. canis trophozoites transfected with full length G. canis virus cDNA transcripts

USDA-ARS?s Scientific Manuscript database

Giardia canis virus (GCV) is a double-stranded RNA (dsRNA) virus of the family Totiviridae. In this study, the full-length cDNA of the G. canis virus was constructed in pPoly2/sfinot vector and RNA was transcribed in vitro. Virus-free G. canis trophozoites were transfected with in vitro transcribed ...

Humic acid inhibits HBV-induced autophagosome formation and induces apoptosis in HBV-transfected Hep G2 cells

PubMed Central

Pant, Kishor; Yadav, Ajay K.; Gupta, Parul; Rathore, Abhishek Singh; Nayak, Baibaswata; Venugopal, Senthil K.

2016-01-01

Hepatitis B Virus (HBV) utilizes several mechanisms to survive in the host cells and one of the main pathways being autophagosome formation. Humic acid (HA), one of the major components of Mineral pitch, is an Ayurvedic medicinal food, commonly used by the people of the Himalayan regions of Nepal and India for various body ailments. We hypothesized that HA could induce cell death and inhibit HBV-induced autophagy in hepatic cells. Incubation of Hep G2.2.1.5 cells (HepG2 cells stably expressing HBV) with HA (100 μM) inhibited both cell proliferation and autophagosome formation significantly, while apoptosis induction was enhanced. Western blot results showed that HA incubation resulted in decreased levels of beclin-1, SIRT-1 and c-myc, while caspase-3 and β-catenin expression were up-regulated. Western blot results showed that HA significantly inhibited the expression of HBx (3-fold with 50 μM and 5-fold with 100 μM) compared to control cells. When HA was incubated with HBx-transfected Hep G2 cells, HBx-induced autophagosome formation and beclin-1 levels were decreased. These data showed that HA induced apoptosis and inhibited HBV-induced autophagosome formation and proliferation in hepatoma cells. PMID:27708347

Virus-Inspired Nanogenes Free from Man-Made Materials for Host-Specific Transfection and Bio-Aided MR Imaging.

PubMed

Zhu, Jing-Yi; Zhang, Ming-Kang; Ding, Xian-Guang; Qiu, Wen-Xiu; Yu, Wu-Yang; Feng, Jun; Zhang, Xian-Zheng

2018-05-01

Many viruses have a lipid envelope derived from the host cell membrane that contributes much to the host specificity and the cellular invasion. This study puts forward a virus-inspired technology that allows targeted genetic delivery free from man-made materials. Genetic therapeutics, metal ions, and biologically derived cell membranes are nanointegrated. Vulnerable genetic therapeutics contained in the formed "nanogene" can be well protected from unwanted attacks by blood components and enzymes. The surface envelope composed of cancer cell membrane fragments enables host-specific targeting of the nanogene to the source cancer cells and homologous tumors while effectively inhibiting recognition by macrophages. High transfection efficiency highlights the potential of this technology for practical applications. Another unique merit of this technology arises from the facile combination of special biofunction of metal ions with genetic therapy. Typically, Gd(III)-involved nanogene generates a much higher T 1 relaxation rate than the clinically used Gd magnetic resonance imaging agent and harvests the enhanced MRI contrast at tumors. This virus-inspired technology points out a distinctive new avenue for the disease-specific transport of genetic therapeutics and other biomacromolecules. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Differences in Env and Gag protein expression patterns and epitope availability in feline immunodeficiency virus infected PBMC compared to infected and transfected feline model cell lines.

PubMed

Roukaerts, Inge D M; Grant, Chris K; Theuns, Sebastiaan; Christiaens, Isaura; Acar, Delphine D; Van Bockstael, Sebastiaan; Desmarets, Lowiese M B; Nauwynck, Hans J

2017-01-02

Env and Gag are key components of the FIV virion that are targeted to the plasma membrane for virion assembly. They are both important stimulators and targets of anti-FIV immunity. To investigate and compare the expression pattern and antigenic changes of Gag and Env in various research models, infected PBMC (the natural FIV host cells) and GFox, and transfected CrFK were stained over time with various Env and Gag specific MAbs. In FIV infected GFox and PBMC, Env showed changes in epitope availability for antibody binding during processing and trafficking, which was not seen in transfected CrFK. Interestingly, epitopes exposed on intracellular Env and Env present on the plasma membrane of CrFK and GFox seem to be hidden on plasma membrane expressed Env of FIV infected PBMC. A kinetic follow up of Gag and Env expression showed a polarization of both Gag and Env expression to specific sites at the plasma membrane of PBMC, but not in other cell lines. In conclusion, mature trimeric cell surface expressed Env might be antigenically distinct from intracellular monomeric Env in PBMC and might possibly be unrecognizable by feline humoral immunity. In addition, Env expression is restricted to a small area on the plasma membrane and co-localizes with a large moiety of Gag, which may represent a preferred FIV budding site, or initiation of virological synapses with direct cell-to-cell virus transmission. Copyright © 2016. Published by Elsevier B.V.

Ultraviolet light-resistant primary transfectants of xeroderma pigmentosum cells are also DNA repair-proficient

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

Stark, M.; Naiman, T.; Canaani, D.

1989-08-15

In a previous work, an immortal xeroderma pigmentosum cell line belonging to complementation group C was complemented to a UV-resistant phenotype by transfection with a human cDNA clone library. We now report that the primary transformants selected for UV-resistance also acquired normal levels of DNA repair. This was assessed both by measurement of UV-induced ({sup 3}H)thymidine incorporation and by equilibrium sedimentation analysis of repair-DNA synthesis. Therefore, the transduced DNA element which confers normal UV-resistance also corrects the excision repair defect of the xeroderma pigmentosum group C cell line.

Software-aided automatic laser optoporation and transfection of cells

PubMed Central

Georg Breunig, Hans; Uchugonova, Aisada; Batista, Ana; König, Karsten

2015-01-01

Optoporation, the permeabilization of a cell membrane by laser pulses, has emerged as a powerful non-invasive and highly efficient technique to induce transfection of cells. However, the usual tedious manual targeting of individual cells significantly limits the addressable cell number. To overcome this limitation, we present an experimental setup with custom-made software control, for computer-automated cell optoporation. The software evaluates the image contrast of cell contours, automatically designates cell locations for laser illumination, centres those locations in the laser focus, and executes the illumination. By software-controlled meandering of the sample stage, in principle all cells in a typical cell culture dish can be targeted without further user interaction. The automation allows for a significant increase in the number of treatable cells compared to a manual approach. For a laser illumination duration of 100 ms, 7-8 positions on different cells can be targeted every second inside the area of the microscope field of view. The experimental capabilities of the setup are illustrated in experiments with Chinese hamster ovary cells. Furthermore, the influence of laser power is discussed, with mention on post-treatment cell survival and optoporation-efficiency rates. PMID:26053047

Bone regeneration with active angiogenesis by basic fibroblast growth factor gene transfected mesenchymal stem cells seeded on porous beta-TCP ceramic scaffolds.

PubMed

Guo, Xiaodong; Zheng, Qixin; Kulbatski, Iris; Yuan, Quan; Yang, Shuhua; Shao, Zengwu; Wang, Hong; Xiao, Baojun; Pan, Zhengqi; Tang, Shuo

2006-09-01

Large segmental bone defect repair remains a clinical and scientific challenge with increasing interest focused on combining gene transfer with tissue engineering techniques. Basic fibroblast growth factor (bFGF) is one of the most prominent osteogenic growth factors that has the potential to accelerate bone healing by promoting the proliferation and differentiation of mesenchymal stem cells (MSCs) and the regeneration of capillary vasculature. However, the short biological half-lives of growth factors may impose severe restraints on their clinical usefulness. Gene-based delivery systems provide a better way of achieving a sustained high concentration of growth factors locally in the defect and delivering a more biologically active product than that achieved by exogenous application of recombinant proteins. The objective of this experimental study was to investigate whether the bFGF gene modified MSCs could enhance the repair of large segmental bone defects. The pcDNA3-bFGF gene transfected MSCs were seeded on biodegradable porous beta tricalcium phosphate (beta-TCP) ceramics and allografted into the 15 mm critical-sized segmental bone defects in the radius of 18 New Zealand White rabbits. The pcDNA3 vector gene transfected MSCs were taken as the control. The follow-up times were 2, 4, 6, 8, 10 and 12 weeks. Scanning electron microscopic, roentgenographic, histologic and immunohistological studies were used to assess angiogenesis and bone regeneration. In vitro, the proliferation and differentiation of bFGF gene transfected MSCs were more active than that of the control groups. In vivo, significantly more new bone formation accompanied by abundant active capillary regeneration was observed in pores of the ceramics loaded with bFGF gene transfected MSCs, compared with control groups. Transfer of gene encoding bFGF to MSCs increases their osteogenic properties by enhancing capillary regeneration, thus providing a rich blood supply for new bone formation. This new b

Protective Effects of Moringa oleifera on HBV Genotypes C and H Transiently Transfected Huh7 Cells.

PubMed

Feustel, Sina; Ayón-Pérez, Fabiola; Sandoval-Rodriguez, Ana; Rodríguez-Echevarría, Roberto; Contreras-Salinas, Homero; Armendáriz-Borunda, Juan; Sánchez-Orozco, L V

2017-01-01

Chronic hepatitis B infection treatment implicates a long-lasting treatment. M. oleifera extracts contain compounds with antiviral, antioxidant, and antifibrotic properties. In this study, the effect of M. oleifera was evaluated in Huh7 cells expressing either HBV genotypes C or H for the antiviral, antifibrotic, anti-inflammatory, and antioxidative responses. Huh7 cells were treated with an aqueous extract of M. oleifera (leaves) at doses of 0, 30, 45, or 60 μ g/mL. The replicative virus and TGF-β1 , CTGF , CAT , IFN-β1 , and pgRNA expressions were measured by real time. HBsAg and IL-6 titers were determined by ELISA. CTGF , TGF-β1 , IFN-β1 , and pgRNA expressions decreased with M. oleifera treatment irrespective of the HBV genotype. HBsAg secretion in the supernatant of transfected Huh7 cells with both HBV genotypes was decreased regardless of the dose of M. oleifera . Similar effect was observed in proinflammatory cytokine IL-6, which had a tendency to decrease at 24 hours of treatment. Transfection with both HBV genotypes strongly decreased CAT expression, which is retrieved with M. oleifera treatment. M. oleifera treatment reduced fibrosis markers, IL-6, and HBsAg secretion in HBV genotypes C and H. However, at the level of replication, only HBV-DNA genotype C was slightly reduced with this treatment.

Guinea pig adenovirus infection does not inhibit cochlear transfection with human adenoviral vectors in a model of hearing loss.

PubMed

Hankenson, F Claire; Wathen, Asheley B; Eaton, Kathryn A; Miyazawa, Toru; Swiderski, Donald L; Raphael, Yehoash

2010-04-01

Routine surveillance of guinea pigs maintained within a barrier facility detected guinea pig adenovirus (GPAdV) in sentinel animals. These guinea pigs served as models of induced hearing loss followed by regeneration of cochlear sensory (hair) cells through transdifferentiation of nonsensory cells by using human adenoviral (hAV) gene therapy. To determine whether natural GPAdV infection affected the ability of hAV vectors to transfect inner ear cells, adult male pigmented guinea pigs (n = 7) were enrolled in this study because of their prolonged exposure to GPAdV-seropositive conspecifics. Animals were deafened chemically (n = 2), received an hAV vector carrying the gene for green fluorescent protein (hAV-GFP) surgically without prior deafening (n = 2), or were deafened chemically with subsequent surgical inoculation of hAV-GFP (n = 3). Cochleae were evaluated by using fluorescence microscopy, and GFP expression in supporting cells indicated that the hAV-GFP vector was able to transfect inner ears in GPAdV-seropositive guinea pigs that had been chemically deafened. Animals had histologic evidence of interstitial pneumonia, attributable to prior infection with GPAdV. These findings confirmed that the described guinea pigs were less robust animal models with diminished utility for the overall studies. Serology tests confirmed that 5 of 7 animals (71%) were positive for antibodies against GPAdV at necropsy, approximately 7 mo after initial detection of sentinel infection. Control animals (n = 5) were confirmed to be seronegative for GPAdV with clinically normal pulmonary tissue. This study is the first to demonstrate that natural GPAdV infection does not negatively affect transfection with hAV vectors into guinea pig inner ear cells, despite the presence of other health complications attributed to the viral infection.

Dispersing Zwitterions into Comb Polymers for Nonviral Transfection: Experiments and Molecular Simulation.

PubMed

Ghobadi, Ahmadreza F; Letteri, Rachel; Parelkar, Sangram S; Zhao, Yue; Chan-Seng, Delphine; Emrick, Todd; Jayaraman, Arthi

2016-02-08

Polymer-based gene delivery vehicles benefit from the presence of hydrophilic groups that mitigate the inherent toxicity of polycations and that provide tunable polymer-DNA binding strength and stable complexes (polyplexes). However, hydrophilic groups screen charge, and as such can reduce cell uptake and transfection efficiency. We report the effect of embedding zwitterionic sulfobetaine (SB) groups in cationic comb polymers, using a combination of experiments and molecular simulations. Ring-opening metathesis polymerization (ROMP) produced comb polymers with tetralysine (K4) and SB pendent groups. Dynamic light scattering, zeta potential measurements, and fluorescence-based experiments, together with coarse-grained molecular dynamics simulations, described the effect of SB groups on the size, shape, surface charge, composition, and DNA binding strength of polyplexes formed using these comb polymers. Experiments and simulations showed that increasing SB composition in the comb polymers decreased polymer-DNA binding strength, while simulations indicated that the SB groups distributed throughout the polyplex. This allows polyplexes to maintain a positive surface charge and provide high levels of gene expression in live cells. Notably, comb polymers with nearly 50 mol % SB form polyplexes that exhibit positive surface charge similarly as polyplexes formed from purely cationic comb polymers, indicating the ability to introduce an appreciable amount of SB functionality without screening surface charge. This integrated simulation-experimental study demonstrates the effectiveness of incorporating zwitterions in polyplexes, while guiding the design of new and effective gene delivery vectors.

[Experimental study on human periodontal ligament cells transfected with human amelogenin gene].

PubMed

Yu, Guang; Shu, Rong; Sun, Ying; Cheng, Lan; Song, Zhong-Chen; Zhang, Xiu-Li

2008-02-01

To construct the recombinant lentiviral vector of human amelogenin gene, infect human periodontal ligament cells with the recombinant lentivirus, and evaluate the feasibility of applying modified PDLCs as seeds for a further periodontal reconstruction. The mature peptide of hAm cDNA was cloned and linked into the vector plasmid, the recombinant plasmid FUAmW was confirmed by double enzyme digestion and sequence analysis. Recombinant lentivirus was prepared from 293T cells by polytheylenimine (PEI)-mediated transient cotransfection. The hPDLCs and 293T cells were infected with the generated lentivirus. The infection efficiency was analysed by detection of green fluorescence protein (GFP) with fluorescent microscope and flow cytometer 72 hours later. The expression of hAm gene was detected by reverse transcription polymerase chain reaction (RT-PCR). The sequence of inserted fragment in recombinant plasmid was identical to the hAm sequence reported in Genebank. Green fluorescence was visible under fluorescent microscope, FCM assay showed that positive percentage was 69.46% and 33.99% in 293T and hPDLCs, respectively. The targeted gene was obtained in the experimental groups by RT-PCR. The recombinan lentiviral vector of hAm gene is constructed successfully and it could be transfected into cultured hPDLCs. hAm gene and seed cells may be used for further study in the fields periodontal tissue engineering. Supported by National Natural Science Foundation of China (Grant No. 30672315).

Micro-optical coherence tomography tracking of magnetic gene transfection via Au-Fe3O4 dumbbell nanoparticles

NASA Astrophysics Data System (ADS)

Shi, Wei; Liu, Xinyu; Wei, Chao; Xu, Zhichuan J.; Sim, Stanley Siong Wei; Liu, Linbo; Xu, Chenjie

2015-10-01

Heterogeneous Au-Fe3O4 dumbbell nanoparticles (NPs) are composed of Au NPs and Fe3O4 NPs that bring in optical and magnetic properties respectively. This article reports the engineering of Au-Fe3O4 NPs as gene carriers for magnetic gene transfection as well as contrast agents for micro-optical coherence tomography (μOCT). As a proof-of-concept, Au-Fe3O4 NPs are used to deliver the green fluorescent protein to HEK 293T cells and their entrance into the cells is monitored through μOCT.Heterogeneous Au-Fe3O4 dumbbell nanoparticles (NPs) are composed of Au NPs and Fe3O4 NPs that bring in optical and magnetic properties respectively. This article reports the engineering of Au-Fe3O4 NPs as gene carriers for magnetic gene transfection as well as contrast agents for micro-optical coherence tomography (μOCT). As a proof-of-concept, Au-Fe3O4 NPs are used to deliver the green fluorescent protein to HEK 293T cells and their entrance into the cells is monitored through μOCT. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr05459a

Electroporation of mRNA as Universal Technology Platform to Transfect a Variety of Primary Cells with Antigens and Functional Proteins.

PubMed

Gerer, Kerstin F; Hoyer, Stefanie; Dörrie, Jan; Schaft, Niels

2017-01-01

Electroporation (EP) of mRNA into human cells is a broadly applicable method to transiently express proteins of choice in a variety of different cell types. We have spent more than a decade to optimize and adapt this method, first for antigen-loading of dendritic cells (DCs), and subsequently for T cells, B cells, bulk PBMCs, and several cell lines. In this regard, antigens were introduced, processed, and presented in context of MHC class I and II. Next to that, functional proteins like adhesion receptors, T-cell receptors (TCRs), chimeric antigen receptors (CARs), constitutively active signal transducers, and others were successfully expressed. We have also established this protocol under full GMP compliance as part of a manufacturing license to produce mRNA-electroporated DCs for therapeutic vaccination in clinical trials. Therefore, we here want to share our universal mRNA electroporation protocol and the experience we have gathered with this method. The advantages of the transfection method presented here are: (1) easy adaptation to different cell types, (2) scalability from 10 6 to approximately 10 8 cells per shot, (3) high transfection efficiency (80-99 %), (4) homogenous protein expression, (5) GMP compliance if the EP is performed in a class A clean room, and (6) no transgene integration into the genome. The provided protocol involves: Opti-MEM® as EP medium, a square-wave pulse with 500 V, and 4 mm cuvettes. To adapt the protocol to differently sized cells, simply the pulse time is altered. Next to the basic protocol, we also provide an extensive list of hints and tricks, which in our opinion are of great value for everyone who intends to use this transfection technique.

Chitosan/Hyaluronic Acid Nanoparticles: Rational Design Revisited for RNA Delivery.

PubMed

Lallana, Enrique; Rios de la Rosa, Julio M; Tirella, Annalisa; Pelliccia, Maria; Gennari, Arianna; Stratford, Ian J; Puri, Sanyogitta; Ashford, Marianne; Tirelli, Nicola

2017-07-03

Chitosan/hyaluronic acid (HA) nanoparticles can be used to deliver an RNA/DNA cargo to cells overexpressing HA receptors such as CD44. For these systems, unequivocal links have not been established yet between chitosan macromolecular (molecular weight; degree of deacetylation, i.e., charge density) and nanoparticle variables (complexation strength, i.e., stability; nucleic acid protection; internalization rate) on one hand, and transfection efficiency on the other hand. Here, we have focused on the role of avidity on transfection efficiency in the CD44-expressing HCT-116 as a cellular model; we have employed two differently sized payloads (a large luciferase-encoding mRNA and a much smaller anti-Luc siRNA), and a small library of chitosans (variable molecular weight and degree of deactylation). The RNA avidity for chitosan showed-as expected-an inverse relationship: higher avidity-higher polyplex stability-lower transfection efficiency. The avidity of chitosan for RNA appears to lead to opposite effects: higher avidity-higher polyplex stability but also higher transfection efficiency. Surprisingly, the best transfecting particles were those with the lowest propensity for RNA release, although this might be a misleading relationship: for example, the same macromolecular parameters that increase avidity can also boost chitosan's endosomolytic activity, with a strong enhancement in transfection. The performance of these nonviral vectors appears therefore difficult to predict simply on the basis of carrier- or payload-related variables, and a more holistic consideration of the journey of the nanoparticle, from cell uptake to cytosolic bioavailability of payload, is needed. It is also noteworthy that the nanoparticles used in this study showed optimal performance under slightly acidic conditions (pH 6.4), which is promising for applications in a tumoral extracellular environment. It is also worth pointing out that under these conditions we have for the first time

Utilization of RNA polymerase I promoter and terminator sequences to develop a DNA transfection system for the study of hepatitis C virus internal ribosomal entry site-dependent translation.

PubMed

Oem, Jae-Ku; Xiang, Zhonghua; Zhou, Yan; Babiuk, Lorne A; Liu, Qiang

2007-09-01

Hepatitis C virus (HCV) causes severe liver diseases in a large population worldwide. HCV protein translation is controlled by an internal ribosomal entry site (IRES) within the 5'-untranslated region (UTR). HCV IRES-dependent translation is critical for HCV-associated pathogenesis. To develop a plasmid DNA transfection system by using RNA polymerase I promoter and terminator sequences for studying HCV IRES-dependent translation. A gene cassette containing HCV 5'-UTR, Renilla luciferase reporter gene, and HCV 3'-UTR was inserted between RNA polymerase I promoter and terminator sequences. HCV IRES-directed translation was determined by luciferase assay after transfection. Transfection of the RNA polymerase I-HCV IRES plasmid into human hepatoma Huh-7 and HepG2 cells resulted in luciferase gene expression. Deletion of the IIIf domain in HCV IRES dramatically reduced luciferase activity. Our results indicated that the plasmid vector system-based on RNA polymerase I promoter and terminator sequences represents an effective approach for the study of HCV IRES-dependent translation.

Hydrogels from feather keratin show higher viscoelastic properties and cell proliferation than those from hair and wool keratins.

PubMed

Esparza, Yussef; Bandara, Nandika; Ullah, Aman; Wu, Jianping

2018-09-01

Hydrogel prepared from keratin shows potential applications in tissue engineering. However, the importance of the keratin sources has not been considered. The objectives of this study were to characterize and compare the rheological (storage modulus), physical (porosity, pore size, swelling capacity, and water contact angle) and in vitro cell compatibility of hydrogel scaffolds prepared from various keratin sources. Keratins were characterized by means of their molecular weight, amino acid composition, thermal and conformational properties. Hydrogels from chicken feather keratins demonstrated substantially higher storage modulus (G') than hair and wool keratin hydrogels. However, higher swelling capacity (>3000%) was determined in hair and wool over feather keratin (1500%) hydrogels. Our results suggest that small molecular weight and β-sheet conformation of feather keratin (~10 kDa) facilitated the self-assembly of rigid hydrogels through disulfide bond re-oxidation. Whereas, high molecular weight (10-75 kDa) stretchable α-helix conformation in hair and wool keratins resulted in weaker hydrogels. The cell cultures using fibroblasts showed the highest proliferation rate on chicken feather keratin hydrogel scaffolds. After 15 days of culture, partial breakdown of keratin fibers was observed. Results indicate that stiffer avian keratins can be used to fabricate more mechanically robust biomaterials than mammalian keratins. Copyright © 2018 Elsevier B.V. All rights reserved.

A Study Showing Research Has Been Valued over Teaching in Higher Education

ERIC Educational Resources Information Center

Chen, Chi Yusn

2015-01-01

Research has been valued and given priority over teaching for a long time in academia. In recent decades, the Taiwanese Ministry of Education has pursued objective and quantitative research criteria and has encouraged higher education institutions to ask teachers to publish papers in SSCI or SCI journals as part of the criteria for promotion and…

Women show a higher level of anxiety during IVF treatment than men and hold different concerns: a cohort study.

PubMed

Schaller, Martin Alexander; Griesinger, Georg; Banz-Jansen, Constanze

2016-05-01

The aim of the present study was to determine levels of anxiety during the course of IVF treatment and gender differences in treatment anxiety. This was a prospective cohort study set in a university affiliated, tertiary care IVF program. 119 women and 82 men entering the clinic to undergo IVF treatment filled out questionnaires containing the Spielberger state-trait-anxiety-inventory (STAI) as well as further items on specific stress triggers. Women and men undergoing IVF have higher levels of anxiety than the average population in Germany. Overall, female patients show significantly higher values (mean ± SD) for state and trait anxiety (47.4 ± 11.0 and 40.1 ± 9.85) than their male partners (41.4 ± 9.66 and 35.3 ± 8.57, p < 0.01). Over the course of several IVF cycles, average STAI scores increased for both genders. When asked about specific stress factors on a 4-point scale from 'not at all' to 'very much so', women report as their main anxiety the failure to achieve a successful pregnancy, scoring significantly higher on questions like 'obtaining a negative pregnancy test' (3.24 ± 0.82, p < 0.01) and 'disclosure of infertility' (3.02 ± 1.10, p < 0.001). Their male partners are more concerned about the health risks the women have to take such as 'side effects of ovarian stimulation' (2.55 ± 0.77, p = 0.002) and 'bleeding or infection after the oocyte aspiration' (2.58 ± 0.84, p = 0.007). Both genders indicated to be very little worried about multiple pregnancies after IVF. Women show a higher level of anxiety during IVF treatment and hold different concerns. Neither of the sexes appears to be familiar with the risks associated with multiple pregnancies, a matter that should better be addressed.

Direct and efficient transfection of mouse neural stem cells and mature neurons by in vivo mRNA electroporation.

PubMed

Bugeon, Stéphane; de Chevigny, Antoine; Boutin, Camille; Coré, Nathalie; Wild, Stefan; Bosio, Andreas; Cremer, Harold; Beclin, Christophe

2017-11-01

In vivo brain electroporation of DNA expression vectors is a widely used method for lineage and gene function studies in the developing and postnatal brain. However, transfection efficiency of DNA is limited and adult brain tissue is refractory to electroporation. Here, we present a systematic study of mRNA as a vector for acute genetic manipulation in the developing and adult brain. We demonstrate that mRNA electroporation is far more efficient than DNA electroporation, and leads to faster and more homogeneous protein expression in vivo Importantly, mRNA electroporation allows the manipulation of neural stem cells and postmitotic neurons in the adult brain using minimally invasive procedures. Finally, we show that this approach can be efficiently used for functional studies, as exemplified by transient overexpression of the neurogenic factor Myt1l and by stably inactivating Dicer nuclease in vivo in adult born olfactory bulb interneurons and in fully integrated cortical projection neurons. © 2017. Published by The Company of Biologists Ltd.

Long-lived weight-reduced αMUPA mice show higher and longer maternal-dependent postnatal leptin surge

PubMed Central

Pinsky, Mariel; Rauch, Maayan; Abbas, Atallah; Sharabi-Nov, Adi; Tamir, Snait

2017-01-01

We investigated whether long-lived weight-reduced αMUPA mice differ from their wild types in postnatal body composition and leptin level, and whether these differences are affected by maternal-borne factors. Newborn αMUPA and wild type mice had similar body weight and composition up to the third postnatal week, after which αMUPA mice maintained lower body weight due to lower fat-free mass. Both strains showed a surge in leptin levels at the second postnatal week, initiating earlier in αMUPA mice, rising higher and lasting longer than in the wild types, mainly in females. Leptin level in dams’ serum and breast milk, and in their pup’s stomach content were also higher in αMUPA than in the WT during the surge peak. Leptin surge preceded the strain divergence in body weight, and was associated with an age-dependent decrease in the leptin:fat mass ratio—suggesting that postnatal sex and strain differences in leptin ontogeny are strongly influenced by processes independent of fat mass, such as production and secretion, and possibly outside fat tissues. Dam removal elevated corticosterone level in female pups from both strains similarly, yet mitigated the leptin surge only in αMUPA–eliminating the strain differences in leptin levels. Overall, our results indicate that αMUPA’s postnatal leptin surge is more pronounced than in the wild type, more sensitive to maternal deprivation, less related to pup’s total adiposity, and is associated with a lower post-weaning fat-free mass. These strain-related postnatal differences may be related to αMUPA’s higher milk-borne leptin levels. Thus, our results support the use of αMUPA mice in future studies aimed to explore the relationship between maternal (i.e. milk-borne) factors, postnatal leptin levels, and post-weaning body composition and energy homeostasis. PMID:29190757

Accumulation of a soluble form of human nectin-2 is required for exerting the resistance against herpes simplex virus type 2 infection in transfected cells.

PubMed

Fujimoto, Y; Ozaki, K; Iwamori, N; Takakuwa, H; Ono, E

2016-03-01

Cell entry of herpes simplex virus type 2 (HSV-2) requires the interaction of viral glycoprotein D (gD) with the receptor nectin-1 and herpesvirus entry mediator (HVEM). In addition, it is known that nectin-2 is also functional as a receptor for HSV-2, although the binding to the gD is weak. To examine an antiviral potential of a soluble form of human nectin-2 (hNectin-2Ig), transfected Vero cells expressing the entire ectodomain of nectin-2 fused to the Fc portion of human IgG were established. Specific binding of hNectin-2Ig to HSV-2 gD was confirmed by ELISA. Competitive ELISA demonstrated that accumulation of hNectin-2Ig in transfected cells increased significantly in a cell culture time dependent manner. Viral growth of several HSV-2 strains was significantly inhibited in the transfected cells that were cultured for 72 hr compared with control Vero cells, but not in cells that were cultured for 24 hr. These results indicate that accumulation of a soluble form of nectin-2 is required for exerting the resistance against HSV-2 infection.

Regulation of early gene expression from the bovine papillomavirus genome in transiently transfected C127 cells.

PubMed Central

Szymanski, P; Stenlund, A

1991-01-01

Expression of bovine papillomavirus (BPV) early gene products is required for viral DNA replication and establishment of the transformed phenotype. By the use of a highly efficient electroporation system, we have examined for the first time the transcriptional activity of BPV promoters in their natural genomic context in a replication-permissive cell line. We have determined that a qualitatively distinct stage of transcription is not detectable prior to DNA replication in transiently transfected cells. This suggests that the transcriptional activity of the BPV genome in stably transformed cells represents the early stage of BPV gene expression. Quantitative differences in promoter activity between transiently transfected and stably transformed cells suggest that subtle changes in gene expression may control progression of the viral life cycle. Deletion analysis demonstrated that the E2 transactivator protein stimulates all of the early promoters through sequences located in the upstream regulatory region. This E2-dependent enhancer was found to be highly redundant, and particular E2 binding sites did not display a preference for particular promoters. Despite this dependence on a common cis-acting sequence, the various promoters displayed different sensitivities to the E2 transactivator. The findings that E2 regulates all promoters and, with the exception of the E2 repressors, that no other known viral gene product appears to affect transcription indicate that the E2 system functions as the master regulator of BPV early gene expression. Images PMID:1656065

Improved differentiation of umbilical cord blood-derived mesenchymal stem cells into insulin-producing cells by PDX-1 mRNA transfection.

PubMed

Van Pham, Phuc; Thi-My Nguyen, Phuoc; Thai-Quynh Nguyen, Anh; Minh Pham, Vuong; Nguyen-Tu Bui, Anh; Thi-Tung Dang, Loan; Gia Nguyen, Khue; Kim Phan, Ngoc

2014-06-01

Numerous studies have sought to identify diabetes mellitus treatment strategies with fewer side effects. Mesenchymal stem cell (MSC) therapy was previously considered as a promising therapy; however, it requires the cells to be trans-differentiated into cells of the pancreatic-endocrine lineage before transplantation. Previous studies have shown that PDX-1 expression can facilitate MSC differentiation into insulin-producing cells (IPCs), but the methods employed to date use viral or DNA-based tools to express PDX-1, with the associated risks of insertional mutation and immunogenicity. Thus, this study aimed to establish a new method to induce PDX-1 expression in MSCs by mRNA transfection. MSCs were isolated from human umbilical cord blood and expanded in vitro, with stemness confirmed by surface markers and multipotentiality. MSCs were transfected with PDX-1 mRNA by nucleofection and chemically induced to differentiate into IPCs (combinatorial group). This IPC differentiation was then compared with that of untransfected chemically induced cells (inducer group) and uninduced cells (control group). We found that PDX-1 mRNA transfection significantly improved the differentiation of MSCs into IPCs, with 8.3±2.5% IPCs in the combinatorial group, 3.21±2.11% in the inducer group and 0% in the control. Cells in the combinatorial group also strongly expressed several genes related to beta cells (Pdx-1, Ngn3, Nkx6.1 and insulin) and could produce C-peptide in the cytoplasm and insulin in the supernatant, which was dependent on the extracellular glucose concentration. These results indicate that PDX-1 mRNA may offer a promising approach to produce safe IPCs for clinical diabetes mellitus treatment. Copyright © 2014 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

Establishment, characterization, virus susceptibility and transfection of cell lines from cobia, Rachycentron canadum (L.), brain and fin.

PubMed

Cheng, T-C; Lai, Y-S; Lin, I-Y; Wu, C-P; Chang, S-L; Chen, T-I; Su, M-S

2010-02-01

Establishment and characterization of two cobia, Rachycentron canadum, cell lines derived from cobia brain (CB) and cobia fin (CF) are described. Caudal fin and brain from juvenile cobia were dissociated for 30 and 10 min, respectively, in phosphate-buffered saline containing 0.25% trypsin at 25 degrees C. The optimal culture condition for both dissociated cells (primary cell culture) was at 28 degrees C in Leibovitz-15 medium containing 10% foetal bovine serum. The cells have been sub-cultured at a ratio of 1:2 for more than 160 passages over a period of 3 years. Origin of the cultured cells was verified by comparison of their sequences of mitochondrial cytochrome oxidase subunit I genes (cox I) with the cox 1 sequence from cobia muscle tissue. The cell lines showed polyploidy. No mycoplasma contamination was detected. Susceptibility to grouper iridovirus was observed for the CB cell line but not the CF cell line. Both cell lines expressed green fluorescent protein after being transfected with green fluorescent reporter gene driven by the cytomegalovirus promoter.

An optimized expression vector for improving the yield of dengue virus-like particles from transfected insect cells.

PubMed

Charoensri, Nicha; Suphatrakul, Amporn; Sriburi, Rungtawan; Yasanga, Thippawan; Junjhon, Jiraphan; Keelapang, Poonsook; Utaipat, Utaiwan; Puttikhunt, Chunya; Kasinrerk, Watchara; Malasit, Prida; Sittisombut, Nopporn

2014-09-01

Recombinant virus-like particles (rVLPs) of flaviviruses are non-infectious particles released from cells expressing the envelope glycoproteins prM and E. Dengue virus rVLPs are recognized as a potential vaccine candidate, but large scale production of these particles is hindered by low yields and the occurrence of cytopathic effects. In an approach to improve the yield of rVLPs from transfected insect cells, several components of a dengue serotype 2 virus prM+E expression cassette were modified and the effect of these modifications was assessed during transient expression. Enhancement of extracellular rVLP levels by simultaneous substitutions of the prM signal peptide and the stem-anchor region of E with homologous cellular and viral counterparts, respectively, was further augmented by codon optimization. Extensive formation of multinucleated cells following transfection with the codon-optimized expression cassette was abrogated by introducing an E fusion loop mutation. This mutation also helped restore the extracellular E levels affected negatively by alteration of a charged residue at the pr-M junction, which was intended to promote maturation of rVLPs during export. Optimized expression cassettes generated in this multiple add-on modification approach should be useful in the generation of stably expressing clones and production of dengue virus rVLPs for immunogenicity studies. Copyright © 2014 Elsevier B.V. All rights reserved.

Use of mariner transposases for one-step delivery and integration of DNA in prokaryotes and eukaryotes by transfection

PubMed Central

Michlewski, Gracjan; Finnegan, David J.; Elfick, Alistair; Rosser, Susan J.

2017-01-01

Abstract Delivery of DNA to cells and its subsequent integration into the host genome is a fundamental task in molecular biology, biotechnology and gene therapy. Here we describe an IP-free one-step method that enables stable genome integration into either prokaryotic or eukaryotic cells. A synthetic mariner transposon is generated by flanking a DNA sequence with short inverted repeats. When purified recombinant Mos1 or Mboumar-9 transposase is co-transfected with transposon-containing plasmid DNA, it penetrates prokaryotic or eukaryotic cells and integrates the target DNA into the genome. In vivo integrations by purified transposase can be achieved by electroporation, chemical transfection or Lipofection of the transposase:DNA mixture, in contrast to other published transposon-based protocols which require electroporation or microinjection. As in other transposome systems, no helper plasmids are required since transposases are not expressed inside the host cells, thus leading to generation of stable cell lines. Since it does not require electroporation or microinjection, this tool has the potential to be applied for automated high-throughput creation of libraries of random integrants for purposes including gene knock-out libraries, screening for optimal integration positions or safe genome locations in different organisms, selection of the highest production of valuable compounds for biotechnology, and sequencing. PMID:28204586

Alpha 2-adrenergic receptor stimulation of phospholipase A2 and of adenylate cyclase in transfected Chinese hamster ovary cells is mediated by different mechanisms

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

Jones, S.B.; Halenda, S.P.; Bylund, D.B.

1991-02-01

The effect of alpha 2-adrenergic receptor activation on adenylate cyclase activity in Chinese hamster ovary cells stably transfected with the alpha 2A-adrenergic receptor gene is biphasic. At lower concentrations of epinephrine forskolin-stimulated cyclic AMP production is inhibited, but at higher concentrations the inhibition is reversed. Both of these effects are blocked by the alpha 2 antagonist yohimbine but not by the alpha 1 antagonist prazosin. Pretreatment with pertussis toxin attenuates inhibition at lower concentrations of epinephrine and greatly potentiates forskolin-stimulated cyclic AMP production at higher concentrations of epinephrine. alpha 2-Adrenergic receptor stimulation also causes arachidonic acid mobilization, presumably via phospholipasemore » A2. This effect is blocked by yohimbine, quinacrine, removal of extracellular Ca2+, and pretreatment with pertussis toxin. Quinacrine and removal of extracellular Ca2+, in contrast, have no effect on the enhanced forskolin-stimulated cyclic AMP production. Thus, it appears that the alpha 2-adrenergic receptor in these cells can simultaneously activate distinct signal transduction systems; inhibition of adenylate cyclase and stimulation of phospholipase A2, both via G1, and potentiation of cyclic AMP production by a different (pertussis toxin-insensitive) mechanism.« less

Transfection of Capsaspora owczarzaki, a close unicellular relative of animals.

PubMed

Parra-Acero, Helena; Ros-Rocher, Núria; Perez-Posada, Alberto; Kożyczkowska, Aleksandra; Sánchez-Pons, Núria; Nakata, Azusa; Suga, Hiroshi; Najle, Sebastián R; Ruiz-Trillo, Iñaki

2018-05-11

How animals emerged from their unicellular ancestor remains a major evolutionary question. New genome data from the closest unicellular relatives of animals has provided important insights into animal origins. We know that the unicellular ancestor of animals had an unexpectedly complex genetic repertoire, including many genes key to animal development and multicellularity. Thus, assessing the function of these genes among unicellular relatives of animals is key to understand how were they co-opted at the onset of Metazoa. However, those analyses have been hampered by the lack of genetic tools. Progress has been made in choanoflagellates and teretosporeans, two of the three lineages closely related to animals, while in filastereans no tools are yet available for functional analysis. Importantly, filastereans possess a striking repertoire of genes involved in transcriptional regulation and other developmental processes. Here, we describe a reliable transfection method for the filasterean Capsaspora owczarzaki We also provide a set of constructs for visualizing subcellular structures in live cells. These tools convert Capsaspora into a unique experimentally tractable organism to address the origin and evolution of animal multicellularity. © 2018. Published by The Company of Biologists Ltd.

A method to detect transfected chloramphenicol acetyltransferase gene expression in intact animals

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

Narayanan, R.; Jastreboff, M.M.; Chiu, Chang Fang

1988-01-01

A rapid procedure is described for assaying chloramphenicol acetyltransferase enzyme activity in intact animals following transfection of the RSV CAT plasmid into mouse bone marrow cells by electroporation. The reconstituted mice were injected with ({sup 14}C)chloramphenicol and ethyl acetate extracts of 24-h urine samples were analyzed by TLC autoradiography for the excretion of {sup 14}C-labeled metabolites. CAT expression in vivo can be detected by the presence of acetylated {sup 14}C-labeled metabolites in the urine within 1 week after bone marrow transplantation and, under the conditions described, these metabolites can be detected for at least 3 months. CAT expression in intactmore » mice as monitored by the urine assay correlates with the CAT expression in the hematopoietic tissues assayed in vitro. This method offers a quick mode of screening for introduced CAT gene expression in vivo without sacrificing the mice.« less

Characterisation of human thyroid epithelial cells immortalised in vitro by simian virus 40 DNA transfection.

PubMed Central

Lemoine, N. R.; Mayall, E. S.; Jones, T.; Sheer, D.; McDermid, S.; Kendall-Taylor, P.; Wynford-Thomas, D.

1989-01-01

Human primary thyroid follicular epithelial cells were transfected with a plasmid containing an origin-defective SV40 genome (SVori-) to produce several immortal cell lines. Two of the 10 cell lines analysed expressed specific features of thyroid epithelial function (iodide-trapping and thyroglobulin production). These two lines were characterised in detail and found to be growth factor-independent, capable of anchorage-independent growth at low frequency but non-tumorigenic in nude mice. These differentiated, These differentiated, partially transformed cell lines were shown to be suitable for gene transfer at high frequency using simple coprecipitation techniques. Images Figure 2 Figure 3 Figure 4 PMID:2557880

Transfection of babesia bovis by double selection with WR99210 and blasticidin-S and its application for functional analysis of thioredoxin peroxidase-1

USDA-ARS?s Scientific Manuscript database

Genetic manipulation is an essential technique to analyze gene function; however, limited methods are available for Babesia bovis, a causative pathogen of the globally important cattle disease, bovine babesiosis. To date, two stable transfection systems have been developed for B. bovis, using select...

Show Me the Money! Why Higher Ed Should Help K-12 Do Economic Impact Studies

ERIC Educational Resources Information Center

Alam, Nadia

2010-01-01

In education, economic impact studies have been largely the product of higher education institutions. Colleges and universities have recognized that they can cultivate public, political and financial support by effectively demonstrating their high return-on-investment value. For more than a decade, all types of higher education institutions have…

In vitro uptake of glutamate in GLAST- and GLT-1-transfected mutant CHO-K1 cells is inhibited by the ethylmercury-containing preservative thimerosal.

PubMed

Mutkus, Lysette; Aschner, Judy L; Syversen, Tore; Shanker, Gouri; Sonnewald, Ursula; Aschner, Michael

2005-01-01

Thimerosal, also known as thimersal, Merthrolate, or sodiumethyl-mercurithiosalicylate, is an organic mercurial compound that is used in a variety of commercial as well as biomedical applications. As a preservative, it is used in a number of vaccines and pharmaceutical products. Its active ingredient is ethylmercury. Both inorganic and organic mercurials are known to interfere with glutamate homeostasis. Brain glutamate is removed mainly by astrocytes from the extracellular fluid via high-affinity astroglial Na+-dependent excitatory amino acid transporters, glutamate/ aspartate transporter (GLAST) and glutamate transporter-1 (GLT-1). The effects of thimerosal on glutamate homeostasis have yet to be determined. As a first step in this process, we examined the effects of thimerosal on the transport of [3H]-d-aspartate, a nonmetabolizable glutamate analog, in Chinese hamster ovary (CHO) cells transfected with two glutamate transporter subtypes, GLAST (EAAT1) and GLT-1 (EAAT2). Additionally, studies were undertaken to determine the effects of thimerosal on mRNA and protein levels of these transporters. The results indicate that thimerosal treatment caused significant but selective changes in both glutamate transporter mRNA and protein expression in CHO cells. Thimerosal-mediated inhibition of glutamate transport in the CHO-K1 cell line DdB7 was more pronounced in the GLT-1-transfected cells compared with the GLAST- transfected cells. These studies suggest that thimerosal accumulation in the central nervous system might contribute to dysregulation of glutamate homeostasis.

Differentiation of umbilical cord derived mesenchymal stem cells to hepatocyte cells by transfection of miR-106a, miR-574-3p, and miR-451.

PubMed

Khosravi, Maryam; Azarpira, Negar; Shamdani, Sara; Hojjat-Assari, Suzzan; Naserian, Sina; Karimi, Mohammad Hossein

2018-08-15

Studying the profile of micro RNAs (miRs) elucidated the highest expressed miRs in hepatic differentiation. In this study, we investigated to clarify the role of three embryonic overexpressed miRs (miR-106a, miR-574-3p and miR-451) during hepatic differentiation of human umbilical cord derived mesenchymal stem cells (UC-MSCs). We furthermore, aimed to explore whether overexpression of any of these miRs alone is sufficient to induce the differentiation of the UC-MSCs into hepatocyte-like cells. UC-MSCs were transfected either alone or together with miR-106a, miR-574-3p and miR-451 and their potential hepatic differentiation and alteration in gene expression profile, morphological changes and albumin secretion ability were investigated. We found that up-regulation of any of these three miRs alone cannot induce expression of all hepatic specific genes. Transfection of each miR alone, led to Sox17, FoxA2 expression that are related to initiation step of hepatic differentiation. However, concurrent ectopic overexpression of three miRs together can induce UC-MSCs differentiation into functionally mature hepatocytes. These results show that miRs have the capability to directly convert UC-MSCs to a hepatocyte phenotype in vitro. Copyright © 2018. Published by Elsevier B.V.

Transgene expression of green fluorescent protein and germ line transmission in cloned pigs derived from in vitro transfected adult fibroblasts.

PubMed

Brunetti, Dario; Perota, Andrea; Lagutina, Irina; Colleoni, Silvia; Duchi, Roberto; Calabrese, Fiorella; Seveso, Michela; Cozzi, Emanuele; Lazzari, Giovanna; Lucchini, Franco; Galli, Cesare

2008-12-01

The pig represents the xenogeneic donor of choice for future organ transplantation in humans for anatomical and physiological reasons. However, to bypass several immunological barriers, strong and stable human genes expression must occur in the pig's organs. In this study we created transgenic pigs using in vitro transfection of cultured cells combined with somatic cell nuclear transfer (SCNT) to evaluate the ubiquitous transgene expression driven by pCAGGS vector in presence of different selectors. pCAGGS confirmed to be a very effective vector for ubiquitous transgene expression, irrespective of the selector that was used. Green fluorescent protein (GFP) expression observed in transfected fibroblasts was also maintained after nuclear transfer, through pre- and postimplantation development, at birth and during adulthood. Germ line transmission without silencing of the transgene was demonstrated. The ubiquitous expression of GFP was clearly confirmed in several tissues including endothelial cells, thus making it a suitable vector for the expression of multiple genes relevant to xenotransplantation where tissue specificity is not required. Finally cotransfection of green and red fluorescence protein transgenes was performed in fibroblasts and after nuclear transfer blastocysts expressing both fluorescent proteins were obtained.

Use of rhenium-188 for in vivo imaging and treatment of human cervical cancer cells transfected with lentivirus expressing sodium iodide symporter.

PubMed

Zhang, Min; Shi, Shuo; Guo, Rui; Miao, Yin; Li, Biao

2016-10-01

Although survival rates for cervical cancer have improved, they need further improvement in patients with distant metastases. The sodium iodine symporter (NIS) gene has often been used in cancer therapy and imaging. We examined the therapeutic effects of rhenium-188 (188Re) in a cervical cancer xenograft model expressing the NIS gene under the control of the tumor-specific human telomerase reverse transcriptase (hTERT) promoter. We constructed two recombinant lentiviral vectors expressing enhanced green fluorescent protein (eGFP) or the NIS gene driven by the hTERT promoter. To determine the tumor-specific transcriptional activity of the hTERT promoter, the eGFP-expressing vector was stably transfected into tumor cells and normal cells. A cervical cancer HeLa cell line stably expressing NIS (HeLa-TERTNIS) was created and examined in a similar way. HeLa and HeLa-TERTNIS tumor xenografts were transplanted in nude mice, and in vivo 188Re distribution was measured using micro-SPECT/CT imaging. The therapeutic effects of 188Re were assessed over 21 days on the basis of tumor volume and the immunohistochemical findings of excised tumors. eGFP expression controlled by the hTERT promoter was substantially higher in the tumor cells than normal cells. Quantitative PCR and western blotting confirmed that HeLa-TERTNIS cells expressed high levels of NIS mRNA and protein, respectively. Further, 188Re uptake and accumulation were significantly higher in HeLa-TERTNIS cells and xenografts than HeLa cells and xenografts. In vitro and in vivo, 188Re significantly reduced the survival of HeLa-TERTNIS cells and inhibited the growth of HeLa-TERTNIS xenografts, respectively. Immunohistochemical staining showed that HeLa-TERTNIS xenograft tumors expressed higher levels of NIS and caspase-3 and lower levels of Ki-67 than HeLa xenograft tumors. Our findings indicated that hTERT promoter-driven expression of the NIS gene in HeLa cells led to 188Re uptake and therapeutic effects. Thus, NIS

Evidence that PC2 is the endogenous pro-neurotensin convertase in rMTC 6-23 cells and that PC1- and PC2-transfected PC12 cells differentially process pro-neurotensin.

PubMed

Rovère, C; Barbero, P; Kitabgi, P

1996-05-10

The neuropeptide precursor proneurotensin/neuromedin N (pro-NT/NN) is mainly expressed and differentially processed in the brain and in the small intestine. We showed previously that rMTC 6-23 cells process pro-NT/NN with a pattern similar to brain tissue and increase pro-NT/NN expression in response to dexamethasone, and that PC12 cells also produce pro-NT/NN but are virtually unable to process it. In addition, PC12 cells were reported to be devoid of the prohormone convertases PC1 and PC2. The present study was designed to identify the proprotein convertase(s) (PC) involved in pro-NT/NN processing in rMTC 6-23 cells and to compare PC1- and PC2-transfected PC12 cells for their ability to process pro-NT/NN. rMTC 6-23 cells were devoid of PC1, PC4, and PC5 but expressed furin and PC2. Stable expression of antisense PC2 RNA in rMTC 6-23 cells led to a 90% decrease in PC2 protein levels that correlated with a > 80% reduction of pro-NT/NN processing. PC2 expression was stimulated by dexamethasone in a time- and concentration-dependent manner. Stable PC12/PC2 transfectants processed pro-NT/NN with a pattern similar to that observed in the brain and in rMTC 6-23 cells. In contrast, stable PC12/PC1 transfectants reproduced the pro-NT/NN processing pattern seen in the gut. We conclude that (i) PC2 is the major pro-NT/NN convertase in rMTC 6-23 cells; (ii) its expression is coregulated with that of pro-NT/NN in this cell line; and (iii) PC2 and PC1 differentially process pro-NT/NN with brain and intestinal phenotype, respectively.

Molecular cloning and nucleotide sequence of a transforming gene detected by transfection of chicken B-cell lymphoma DNA

NASA Astrophysics Data System (ADS)

Goubin, Gerard; Goldman, Debra S.; Luce, Judith; Neiman, Paul E.; Cooper, Geoffrey M.

1983-03-01

A transforming gene detected by transfection of chicken B-cell lymphoma DNA has been isolated by molecular cloning. It is homologous to a conserved family of sequences present in normal chicken and human DNAs but is not related to transforming genes of acutely transforming retroviruses. The nucleotide sequence of the cloned transforming gene suggests that it encodes a protein that is partially homologous to the amino terminus of transferrin and related proteins although only about one tenth the size of transferrin.

Transfection and heat-inducible expression of molluscan promoter-luciferase reporter gene constructs in the Biomphalaria glabrata embryonic snail cell line.

PubMed

Yoshino, T P; Wu, X J; Liu, H D

1998-09-01

Studies were initiated to begin developing a genetic transformation system for cells derived from the freshwater gastropod, Biomphalaria glabrata, an intermediate host of the human blood fluke Schistosoma mansoni. Using a 70-kD heat-shock protein (HSP70) cDNA probe obtained from the B. glabrata embryonic (Bge) cell line, we cloned from Bge cells a complete HSP70 gene including a 1-kb genomic DNA fragment in its 5'-flanking region containing sequences indicative of a HSP promoter. Identified in the 5'-half (416 nucleotides) of this genomic fragment were TATA and CAAT boxes, two putative transcription initiation sites, and a series of palindromic DNA repeats with shared homology to the heat-shock element consensus sequence (Bge HSP70(0.5k) promoter). The 3'-half of this upstream flanking region was comprised of a 508-base intron located immediately 5' of the ATG start codon. To determine the functionality of the putative snail promoter sequence, Bge HSP promoter/luciferase (Luc) reporter gene constructs were introduced into Bge cells by N-(1-(2,3-dioleoyloxy) propyl)-N,N,N-trimethylammonium methylsulfate (DOTAP)-mediated transfection methods, and assayed for Luc activity 48 hr following a 1.5-hr heat-shock treatment (40 degrees C). Compared with control vectors or the Bge HSP70(0.5k/1.0k) promoter constructs at 26 degrees C, a 10- to 300-fold increase in Luc expression was obtained only in the Bge HSP70 promoter/Luc-transfected cells following heat-shock. Results of transfection experiments demonstrate that the Bge HSP70(0.5k) DNA segment contains appropriate promoter sequences for driving temperature-inducible gene expression in the Bge snail cell line. This report represents the first isolation and functional characterization of an inducible promoter from a freshwater gastropod mollusc. Successful transient expression of a foreign reporter gene in Bge cells using a homologous, inducible promoter sequence now paves the way for development of methods for stable

Single-provenance mature conifers show higher non-structural carbohydrate storage and reduced growth in a drier location.

PubMed

Piper, Frida I; Fajardo, Alex; Hoch, Günter

2017-08-01

Since growth is more sensitive to drought than photosynthesis, trees inhabiting dry regions are expected to exhibit higher carbohydrate storage and less growth than their conspecifics from more humid regions. However, the same pattern can be the result of different genotypes inhabiting contrasting humidity conditions. To test if reduced growth and high carbohydrate storage are environmentally driven by drought, we examined the growth and non-structural carbohydrate (NSC) concentrations in single-provenance stands of mature trees of Pinus contorta Douglas and Pinus ponderosa Douglas ex C. Lawson planted at contrasting humidity conditions (900 versus 300 mm of annual precipitation) in Patagonia, Chile. Individual tree growth was measured for each species and at each location as mean basal area increment of the last 10 years (BAI10), annual shoot elongation for the period 2011-14, and needle length for 2013 and 2014 cohorts. Additionally, needle, branch, stem sapwood and roots were collected from each sampled tree to determine soluble sugars, starch and total NSC concentrations. The two species showed lower mean BAI10 and 2013 needle length in the dry site; P. ponderosa also had lower annual shoot extension for 2011 and 2014, and lower 2014 needle length, in the dry than in the mesic site. By contrast, NSC concentrations of all woody tissues for both species were either similar or higher in the dry site when compared with the mesic site. Patterns of starch and sugars were substantially different: starch concentrations were similar between sites except for roots of P. ponderosa, which were higher in the dry site, while sugar concentrations of all woody tissues in both species were higher in the dry site. Overall, our study provides evidence that reduced growth along with carbon (C) accumulation is an environmentally driven response to drought. Furthermore, the significant accumulation of low-molecular weight sugars in the dry site is compatible with a prioritized C

The ability of a collagen/calcium phosphate scaffold to act as its own vector for gene delivery and to promote bone formation via transfection with VEGF(165).

PubMed

Keeney, Michael; van den Beucken, Jeroen J J P; van der Kraan, Peter M; Jansen, John A; Pandit, Abhay

2010-04-01

Collagen/calcium phosphate scaffolds have been used for bone reconstruction due to their inherent similarities to the bone extracellular matrix. Calcium phosphate alone has also been used as a non-viral vector for gene delivery. The aim of this study was to determine the capability of a collagen/calcium phosphate scaffold to deliver naked plasmid DNA and mediate transfection in vivo. The second goal of the study was to deliver a plasmid encoding vascular endothelial growth factor(165) (pVEGF(165)) to promote angiogenesis, and hence bone formation, in a mouse intra-femoral model. The delivery of naked plasmid DNA resulted in a 7.6-fold increase in mRNA levels of beta-Galactosidase compared to the delivery of plasmid DNA complexed with a partially degraded PAMAM dendrimer (dPAMAM) in a subcutaneous murine model. When implanted in a muirne intra-femoral model, the delivery of pVEGF(165) resulted in a 2-fold increase in bone volume at the defect site relative to control scaffolds without pVEGF(165). It was concluded that a collagen/calcium phosphate scaffold can mediate transfection without the use of additional transfection vectors and can promote bone formation in a mouse model via the delivery of pVEGF(165). 2009 Elsevier Ltd. All rights reserved.

SUMOylated IRF-1 shows oncogenic potential by mimicking IRF-2

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

Park, Sun-Mi; School of Biological Sciences and Biotechnology, Chonnam National University, Gwangju 500-757; Chae, Myounghee

2010-01-01

Interferon regulatory factor-1 (IRF-1) is an interferon-induced transcriptional activator that suppresses tumors by impeding cell proliferation. Recently, we demonstrated that the level of SUMOylated IRF-1 is elevated in tumor cells, and that SUMOylation of IRF-1 attenuates its tumor-suppressive function. Here we report that SUMOylated IRF-1 mimics IRF-2, an antagonistic repressor, and shows oncogenic potential. To demonstrate the role of SUMOylated IRF-1 in tumorigenesis, we used SUMO-IRF-1 recombinant protein. Stable expression of SUMO-IRF-1 in NIH3T3 cells resulted in focus formation and anchorage-independent growth in soft agar. Inoculation of SUMO-IRF-1-transfected cells into athymic nude mice resulted in tumor formation and infiltration ofmore » adipose tissues. Finally, we demonstrated that SUMO-IRF-1 transforms NIH3T3 cells in a dose-dependent manner suggesting that SUMOylated IRF-1 may act as an oncogenic protein in tumor cells.« less

Mesoporous Silica Nanomaterials for Applications in Catalysis, Sensing, Drug Delivery and Gene Transfection

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

Radu, Daniela Rodica

2004-01-01

surface of MSN and utilize them to complex cationic DNA. The p-EGFP-CI gene-coated MSN nanocomposite was able to transfect cancer cell lines, such as human HeLa and CHO cancer cell lines. The gene carrier ability of MSNs was further proved by transfecting primary cells and cotransfecting of two different genes in cancer cell lines. In sum, MSN are versatile partners in several types of applications.« less

Poly(ethylenimine) conjugated bioreducible dendrimer for efficient gene delivery.

PubMed

Nam, Kihoon; Jung, Simhyun; Nam, Joung-Pyo; Kim, Sung Wan

2015-12-28

Branched poly(ethylenimine) (PEI) 25 kDa is an efficient gene delivery vector with outstanding gene condensation ability and great endosome escape activity. However, it also induces higher cytotoxicity. Transfection efficiency and toxicity of PEI are highly dependent upon their molecular weight and structure. We developed a bioreducible poly(ethylenimine) (PEI (-s-s-)) derived from low molecular weight PEI (1.8 kDa) for efficient gene delivery. Bioreducible core molecule is expected to increase molecular weight and reduce the cytotoxicity of the copolymer. PEI (-s-s-) polyplexes showed higher transfection efficiency and lower cytotoxicity compared to branched PEI 25 kDa, Lipofectamine® 2000 and, FuGENE® 6. In addition, PEI (-s-s-) derivative (16 kDa) formed stable polyplexes with a zeta-potential value of +34 mV and polyplex size of 61 nm. PEI (-s-s-) derivative (16 kDa) showed excellent transfection efficiency: 3.6 times higher than branched PEI 25 kDa in HeLa cells and 7.4 times higher than Lipofectamine® 2000 in H9C2 cell. The derivatives also showed lower cytotoxicity compared with Lipofectamine® 2000 and PEI 25 kDa in various cell types. In addition, newly synthesized PEI (-s-s-) derivatives have high reproducibility. Copyright © 2015 Elsevier B.V. All rights reserved.

Promoter variant -204A > C of the cholesterol 7α-hydroxylase gene: association with response to plant sterols in humans and increased transcriptional activity in transfected HepG2 cells.

PubMed

De Castro-Orós, Isabel; Pampín, Sandra; Cofán, Montserrat; Mozas, Pilar; Pintó, Xavier; Salas-Salvadó, Jordi; Rodríguez-Rey, Jose C; Ros, Emilio; Civeira, Fernando; Pocoví, Miguel

2011-04-01

The bile acid pool influences intestinal cholesterol absorption because this process is strictly dependent on micellar solubilization, which is disrupted by plant sterols (PS). Plasma lipid variation relates to promoter variant -204A > C (rs3808607) of the CYP7A1 gene encoding for 7α-hydroxylase, an enzyme for bile acid synthesis. We hypothesized that this polymorphism would be associated with variability in lipid responses to PS. We investigated 67 subjects (31 AA and 36 AC + CC) with lipid responses to PS documented in two studies. To assess the functionality of the -204A > C variant, electrophoretic mobility gel shift assays were performed and luciferase reporter plasmids containing the promoter were transfected into HepG2 cells. Compared to AA-subjects, C-carriers showed significantly higher adjusted mean reductions in total cholesterol (0.14 versus 0.43 mmol/L, P = 0.042) and increases in lathosterol-to-cholesterol ratios (0.10 versus 0.75, P = 0.013). The C-construct caused a 78% promoter activity increase and gel-shift assays showed lower affinity for nuclear transcription factors, while in silico experiments predicted a binding site for inhibitory nuclear factors RXR-CAR. Results suggest that promoter -204A > C variant is associated with enhanced CYP7A1 activity. Increased intestinal bile acids and ensuing more efficient cholesterol absorption might explain why C-allele carriers show enhanced cholesterol lowering and increased feedback cholesterol synthesis to PS intervention. Copyright © 2010 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Transfection of gene regulation nanoparticles complexed with pDNA and shRNA controls multilineage differentiation of hMSCs.

PubMed

Kim, Hye Jin; Yi, Se Won; Oh, Hyun Jyung; Lee, Jung Sun; Park, Ji Sun; Park, Keun-Hong

2018-05-29

Overexpression and knockdown of specific proteins can control stem cell differentiation for therapeutic purposes. In this study, we fabricated RUNX2, SOX9, and C/EBPα plasmid DNAs (pDNAs) and ATF4-targeting shRNA (shATF4) to induce osteogenesis, chondrogenesis, and adipogenesis of human mesenchymal stem cells (hMSCs). The pDNAs and shATF4 were complexed with TRITC-gene regulation nanoparticles (GRN). Osteogenesis-related gene expression was reduced at early (12 h) and late (36 h) time points after co-delivery of shATF4 and SOX9 or C/EBPα pDNA, respectively, and osteogenesis was inhibited in these hMSCs. By contrast, osteogenesis-related genes were highly expressed upon co-delivery of RUNX2 and ATF4 pDNAs. DEX in GRN enhanced chondrogenic differentiation. Expression of osteogenesis-, chondrogenesis-, and adipogenesis-related genes was higher in hMSCs transfected with NPs complexed with RUNX2 and ATF4 pDNAs, shATF4 and SOX9 pDNA, and shATF4 and C/EBPα pDNA for 72 h than in control hMSCs, respectively. Moreover, delivery of these NPs also increased expression of osteogenesis-, chondrogenesis-, and adipogenesis-related proteins. These alterations in expression led to morphological changes, indicating that hMSCs differentiated into osteoblasts, chondrocytes, and adipose cells. Copyright © 2018 Elsevier Ltd. All rights reserved.

PACAP receptor pharmacology and agonist bias: analysis in primary neurons and glia from the trigeminal ganglia and transfected cells

PubMed Central

Walker, C S; Sundrum, T; Hay, D L

2014-01-01

Background and Purpose A major challenge in the development of new medicines targeting GPCRs is the ability to quantify drug action in physiologically relevant models. Primary cell models that closely resemble the clinically relevant in vivo site of drug action are important translational tools in drug development. However, pharmacological studies in these models are generally very limited due to the methodology used. Experimental Approach We used a neuropeptide system to demonstrate the applicability of using highly sensitive signalling assays in primary cells. We quantified the action of pituitary adenylate cyclase-activating peptide (PACAP)-38, PACAP-27 and vasoactive intestinal polypeptide in primary cultures of neurons and glia derived from rat trigeminal ganglia (TG), comparing our observations to transfected cells. Key Results PACAP-responsive receptors in rat trigeminal neurons, glia and transfected PAC1n receptors were pharmacologically distinct. PACAP-38, but not PACAP-27, activated ERK in glia, while both forms stimulated cellular cAMP production. PACAP(6–38) also displayed cell-type-dependent, agonist-specific, antagonism. Conclusions and Implications The complexity of PACAP pharmacology in the TG may help to direct, more effectively, the development of disease treatments targeting the PACAP receptor. We suggest that these methodologies are broadly applicable to other primary cell types of human or animal origin, and that our approach may allow more thorough characterization of ligand properties in physiologically relevant cell types. PMID:24303997

Oxime Ether Lipids as Transfection Agents: Assembly and Complexation with siRNA.

PubMed

Puri, Anu; Zampino, Serena; Viard, Mathias; Shapiro, Bruce A

2017-01-01

RNAi-based therapeutic approaches to combat cancer and other diseases are currently an area of great interest. However, practical applications of this approach rely on optimal tools to carry and deliver siRNA to the desired site. Oxime ether lipids (OELs) are a class of molecules among other various carriers being examined for siRNA delivery. OELs, relatively new candidates, belong to a class of non-glycerol based lipids and have begun to claim their place as an siRNA delivery carrier in the field of RNAi therapy. Chemical synthesis steps of OELs are considered relatively simple with the ability to modify the functionalities as desired. OEL-siRNA complexes can be assembled in the presence of serum-containing buffers (or cell culture media) and recent data from our and other groups have demonstrated that OELs are viable carriers for siRNA delivery in the cell culture systems. In this chapter, we provide the details of experimental protocols routinely used in our laboratory to examine OEL-siRNA complexes including their assembly, stability, and transfection efficiencies.

TACN-based cationic lipids with amino acid backbone and double tails: materials for non-viral gene delivery.

PubMed

Wang, Bing; Yi, Wen-Jing; Zhang, Ji; Zhang, Qin-Fang; Xun, Miao-Miao; Yu, Xiao-Qi

2014-04-01

Cationic lipids have become an efficient type of non-viral vectors for gene delivery. In this Letter, four cationic lipids containing 1,4,7-triazacyclononane (TACN) headgroup, glutamic/aspartic acid backbone and dioleyl tails were designed and synthesized. The TACN headgroup gives these lipids excellent pH buffering capacities, which were higher than branched 25 kDa PEI. Cationic liposomes prepared from these lipids and DOPE showed good DNA affinity, and full DNA condensation was found at N/P ratio of 3 via agarose gel electrophoresis. The lipoplexes were characterized by dynamic light scattering (DLS) assay, which gave proper particle sizes and zeta-potentials for transfection. In vitro gene transfection results in two cell lines reveal that TAN (with aspartic acid and amide bond in the structure) shows the best transfection efficiency, which is close to commercially available transfection agent Lipofectamine 2000. Copyright © 2014 Elsevier Ltd. All rights reserved.

Show Me Yours: Developing a Faculty-Wide Interdisciplinary Initiative in Built Environment Higher Education

ERIC Educational Resources Information Center

Wilson, Stephanie; Zamberlan, Lisa

2012-01-01

In the competitive market of higher education, government funding agencies consider universities accountable for ensuring a better alignment between educational processes, graduate capabilities and real world employability. Workforce leaders have developed new expectations about the capabilities of graduating students, expecting to employ…

Bovine papillomavirus type 4 L1 gene transfection in a Drosophila S2 cell expression system: absence of L1 protein expression

PubMed Central

Góes, Luiz Gustavo Bentim; de Freitas, Antonio Carlos; Ferraz, Oilita Pereira; Rieger, Tania Tassinari; dos Santos, José Ferreira; Pereira, Alexandre; Beçak, Willy; Lindsey, Charles J.; de Cassia Stocco, Rita

2008-01-01

The development of a bovine papillomavirus (BPV) vaccine is an outstanding challenge. BPV protein L1 gene transfection in the Drosophila melanogaster S2 cell expression system failed to produce L1 protein notwithstanding correct L1 gene insertion. Severe genetic inbalance in the host cell line, including cytogenetic alterations, may account for the lack of protein expression. PMID:24031166

Transport of bile acids in multidrug-resistance-protein 3-overexpressing cells co-transfected with the ileal Na+-dependent bile-acid transporter.

PubMed Central

Zelcer, Noam; Saeki, Tohru; Bot, Ilse; Kuil, Annemieke; Borst, Piet

2003-01-01

Many of the transporters involved in the transport of bile acids in the enterohepatic circulation have been characterized. The basolateral bile-acid transporter of ileocytes and cholangiocytes remains an exception. It has been suggested that rat multidrug resistance protein 3 (Mrp3) fulfills this function. Here we analyse bile-salt transport by human MRP3. Membrane vesicles from insect ( Spodoptera frugiperda ) cells expressing MRP3 show time-dependent uptake of glycocholate and taurocholate. Furthermore, sulphated bile salts were high-affinity competitive inhibitors of etoposide glucuronide transport by MRP3 (IC50 approximately 10 microM). Taurochenodeoxycholate, taurocholate and glycocholate inhibited transport at higher concentrations (IC50 approximately 100, 250 and 500 microM respectively). We used mouse fibroblast-like cell lines derived from mice with disrupted Mdr1a, Mdr1b and Mrp1 genes to generate transfectants that express the murine apical Na+-dependent bile-salt transporter (Asbt) and MRP3. Uptake of glycocholate by these cells is Na+-dependent, with a K(m) and V(max) of 29+/-7 microM and 660 +/- 63 pmol/min per mg of protein respectively and is inhibited by several organic-aniontransport inhibitors. Expression of MRP3 in these cells limits the accumulation of glycocholate and increases the efflux from cells preloaded with taurocholate or glycocholate. In conclusion, we find that MRP3 transports both taurocholate and glycocholate, albeit with low affinity, in contrast with the high-affinity transport by rat Mrp3. Our results suggest that MRP3 is unlikely to be the principal basolateral bile-acid transporter of ileocytes and cholangiocytes, but that it may have a role in the removal of bile acids from the liver in cholestasis. PMID:12220224

Correlated fluorescence microscopy and cryo-electron tomography of virus-infected or transfected mammalian cells

PubMed Central

Hampton, Cheri M; Strauss, Joshua D; Ke, Zunlong; Dillard, Rebecca S; Hammonds, Jason E; Alonas, Eric; Desai, Tanay M; Marin, Mariana; Storms, Rachel E; Leon, Fredrick; Melikyan, Gregory B; Santangelo, Philip J; Spearman, Paul W; Wright, Elizabeth R

2016-01-01

Correlative light and electron microscopy (CLEM) combines spatiotemporal information from fluorescence light microscopy (fLM) with high-resolution structural data from cryo-electron tomography (cryo-ET). These technologies provide opportunities to bridge knowledge gaps between cell and structural biology. Here we describe our protocol for correlated cryo-fLM, cryo-electron microscopy (cryo-EM), and cryo-ET (i.e., cryo-CLEM) of virus-infected or transfected mammalian cells. Mammalian-derived cells are cultured on EM substrates, using optimized conditions that ensure that the cells are spread thinly across the substrate and are not physically disrupted. The cells are then screened by fLM and vitrified before acquisition of cryo-fLM and cryo-ET images, which is followed by data processing. A complete session from grid preparation through data collection and processing takes 5–15 d for an individual experienced in cryo-EM. PMID:27977021

Carbamate-linked cationic lipids with different hydrocarbon chains for gene delivery.

PubMed

Shi, Jia; Yu, Shijun; Zhu, Jie; Zhi, Defu; Zhao, Yinan; Cui, Shaohui; Zhang, Shubiao

2016-05-01

A series of carbamate-linked cationic lipids containing saturated or unsaturated hydrocarbon chains and quaternary ammonium head were designed and synthesized. After recrystallization, carbamate-linked cationic lipids with high purity (over 95%) were obtained. The structures of these lipids were proved by IR spectrum, HR-ESI-MS, HPLC, (1)H NMR and (13)C NMR. The liposomes were prepared by using these cationic lipids and neutral lipid DOPE. Particle size and zeta-potential were studied to show that they were suitable for gene transfection. The DNA-bonding ability of C12:0, C14:0 and C18:1 cationic liposomes was much better than others. The results of transfection showed that hydrophobic chains of these lipids have great effects on their transfection activity. The lipids bearing C12:0, C14:0 saturated chains or C18:1 unsaturated chain showed relatively higher transfection efficiency and lower cytotoxicity. So these cationic lipids could be used as non-viral gene carriers for further studies. Copyright © 2016 Elsevier B.V. All rights reserved.

Time-lapse imaging of mitosis after siRNA transfection.

PubMed

Mackay, Douglas R; Ullman, Katharine S; Rodesch, Christopher K

2010-06-06

Changes in cellular organization and chromosome dynamics that occur during mitosis are tightly coordinated to ensure accurate inheritance of genomic and cellular content. Hallmark events of mitosis, such as chromosome movement, can be readily tracked on an individual cell basis using time-lapse fluorescence microscopy of mammalian cell lines expressing specific GFP-tagged proteins. In combination with RNAi-based depletion, this can be a powerful method for pinpointing the stage(s) of mitosis where defects occur after levels of a particular protein have been lowered. In this protocol, we present a basic method for assessing the effect of depleting a potential mitotic regulatory protein on the timing of mitosis. Cells are transfected with siRNA, placed in a stage-top incubation chamber, and imaged using an automated fluorescence microscope. We describe how to use software to set up a time-lapse experiment, how to process the image sequences to make either still-image montages or movies, and how to quantify and analyze the timing of mitotic stages using a cell-line expressing mCherry-tagged histone H2B. Finally, we discuss important considerations for designing a time-lapse experiment. This strategy is complementary to other approaches and offers the advantages of 1) sensitivity to changes in kinetics that might not be observed when looking at cells as a population and 2) analysis of mitosis without the need to synchronize the cell cycle using drug treatments. The visual information from such imaging experiments not only allows the sub-stages of mitosis to be assessed, but can also provide unexpected insight that would not be apparent from cell cycle analysis by FACS.

Occult infection related hepatitis B surface antigen variants showing lowered secretion capacity

PubMed Central

Kim, Hong; Lee, Seoung-Ae; Won, You-Sub; Lee, HyunJoo; Kim, Bum-Joon

2015-01-01

AIM: To elucidate the molecular mechanisms underlying hepatitis B virus (HBV) occult infection of genotype C. METHODS: A total of 10 types of hepatitis B surface antigen (HBsAg) variants from a Korean occult cohort were used. After a complete HBV genome plasmid mutated such that it does not express HBsAg and plasmid encoding, each HBsAg variant was transiently co-transfected into HuH-7 cells. The secretion capacity and intracellular expression of the HBV virions and HBsAgs in their respective variants were analyzed using real-time quantitative polymerase chain reaction assays and commercial HBsAg enzyme-linked immunosorbent assays, respectively. RESULTS: All variants exhibited lower levels of HBsAg secretion into the medium compared with the wild type. In particular, in eight of the ten variants, very low levels of HBsAg secretion that were similar to the negative control were detected. In contrast, most variants (9/10) exhibited normal virion secretion capacities comparable with, or even higher than, the wild type. This provided new insight into the intrinsic nature of occult HBV infection, which leads to HBsAg sero-negativeness but has horizontal infectivity. Furthermore, most variants generated higher reactive oxidative species production than the wild type. This finding provides potential links between occult HBV infection and liver disease progression. CONCLUSION: The presently obtained data indicate that deficiency in the secretion capacity of HBsAg variants may have a pivotal function in the occult infections of HBV genotype C. PMID:25684944

Partial agonist clonidine mediates alpha(2)-AR subtypes specific regulation of cAMP accumulation in adenylyl cyclase II transfected DDT1-MF2 cells.

PubMed

Limon-Boulez, I; Bouet-Alard, R; Gettys, T W; Lanier, S M; Maltier, J P; Legrand, C

2001-02-01

alpha2-Adrenergic receptor (alpha(2)-AR) activation in the pregnant rat myometrium at midterm potentiates beta(2)-AR stimulation of adenylyl cyclase (AC) via Gbetagamma regulation of the type II isoform of adenylyl cyclase. However, at term, alpha(2)-AR activation inhibits beta(2)-AR stimulation of AC. This phenomenon is associated with changes in alpha(2)-AR subtype expression (midterm alpha(2A/D)-AR > alpha(2B)-AR; term alpha(2B) >or =alpha(2A/D)-AR), without any change in ACII mRNA, suggesting that alpha(2A/D)- and alpha(2B)-AR differentially regulate beta(2)-cAMP production. To address this issue, we have stably expressed the same density of alpha(2A/D)- or alpha(2B)-AR with AC II in DDT1-MF2 cells. Clonidine (partial agonist) increased beta(2)-AR-stimulated cAMP production in alpha(2A/D)-AR-ACII transfectants but inhibited it in alpha(2B)-AR-ACII transfectants. In contrast, epinephrine (full agonist) enhanced beta(2)-stimulated ACII in both alpha(2A)- and alpha(2B)-ACII clonal cell lines. 4-Azidoanilido-[alpha-(32)P]GTP-labeling of activated G proteins indicated that, in alpha(2B)-AR transfectants, clonidine activated only Gi(2), whereas epinephrine, the full agonist, effectively coupled to Gi(2) and Gi(3). Thus, partial and full agonists selectively activate G proteins that lead to drug specific effects on effectors. Moreover, these data indicate that Gi(3) activation is required for potentiation of beta(2)-AR stimulation of AC by alpha(2A/D) and alpha(2B)-AR in DDT1-MF2 cells. This may reflect an issue of the amount of Gbetagamma released upon receptor activation and/or betagamma composition of Gi(3) versus Gi(2).

[Construction and characterization of liposomal magnetofection system in pig kidney cells].

PubMed

Chen, Wenjie; Cui, Haixin; Zhao, Xiang; Cui, Jinhui; Wang, Yan; Sun, Changjiao

2014-06-01

Magnetic nano gene vector is one of the non-viral gene vectors, modified by functional group to bind cationic transfect reagents. Coupling magnetofection with the universal lipofection we developed a novel somatic cell transfection method as the so-called liposomal magnetofection (LMF). This approach is potential to provide somatic cell cloning with stable genetic cell lines to cultivate transgenic animals. In order to construct such liposomal magnetic gene vectors complexes system, we used nano magnetic gene vector to combine with liposomal cationic transfect reagents by molecular self-assembly. This vectors system successfully carried exogenous gene and then transfected animal somatic cells. Here, we conducted atomic force microscopy (AFM), zeta potential-diameter analysis and other characterization experiments to investegate the size distribution and morphology of magnetic nanoparticles, the way of the vectors to load and concentrate DNA molecules. Our data reveal that, the LMF of Pig Kidney cells exhibited higher transfection efficiency comparing with the transfection mediated by the commercial lipofectamine2000. Moreover, LMF method overcomes the constraint of transient expression mediated by lipofection. Meanwhile, MTT assay showed low cytotoxicity of LMF. Hence, LMF is a feasible, low cytotoxic and effective method of cell transfection.

Generation of murine induced pluripotent stem cells by using high-density distributed electrodes network.

PubMed

Lu, Ming-Yu; Li, Zhihong; Hwang, Shiaw-Min; Linju Yen, B; Lee, Gwo-Bin

2015-09-01

This study reports a robust method of gene transfection in a murine primary cell model by using a high-density electrodes network (HDEN). By demonstrating high cell viability after gene transfection and successful expression of transgenes including fluorescent proteins, the HDEN device shows great promise as a solution in which reprogramming efficiency using non-viral induction for generation of murine induced pluripotent stem cells (iPSCs) is optimized. High and steady transgene expression levels in host cells of iPSCs can be demonstrated using this method. Moreover, the HDEN device achieved successful gene transfection with a low voltage of less than 180 V while requiring relatively low cell numbers (less than 1.5 × 10(4) cells). The results are comparable to current conventional methods, demonstrating a reasonable fluorescent-plasmid transfection rate (42.4% in single transfection and 24.5% in triple transfection) and high cell viability of over 95%. The gene expression levels of each iPSC factor was measured to be over 10-fold higher than that reported in previous studies using a single mouse embryonic fibroblast cell. Our results demonstrate that the generation of iPSCs using HDEN transfection of plasmid DNA may be a feasible and safe alternative to using viral transfection methods in the near future.

Older adults show higher increases in lower-limb muscle activity during whole-body vibration exercise.

PubMed

Lienhard, Karin; Vienneau, Jordyn; Nigg, Sandro; Friesenbichler, Bernd; Nigg, Benno M

2017-02-08

The purpose of this study was to compare lower limb muscle activity during whole-body vibration (WBV) exercise between a young and an older study population. Thirty young (25.9±4.3yrs) and thirty older (64.2±5.3yrs) individuals stood on a side-alternating WBV platform while surface electromyography (sEMG) was measured for the tibialis anterior (TA), gastrocnemius medialis (GM), soleus (SOL), vastus lateralis (VL), vastus medialis (VM), and biceps femoris (BF). The WBV protocol included nine vibration settings consisting of three frequencies (6, 11, 16Hz) x three amplitudes (0.9, 2.5, 4.0mm), and three control trials without vibration (narrow, medium, wide stance). The vertical platform acceleration (peak values of maximal displacement from equilibrium) was quantified during each vibration exercise using an accelerometer. The outcomes of this study showed that WBV significantly increased muscle activity in both groups for most vibration conditions in the TA (averaged absolute increase: young: +3.9%, older: +18.4%), GM (young: +4.1%, older: +9.5%), VL (young: +6.3%, older: +12.6%) and VM (young: +5.4%, older: +8.0%), and for the high frequency-amplitude combinations in the SOL (young: +7.5%, older: +12.6%) and BF (young: +1.9%, older: +7.5%). The increases in sEMG activity were significantly higher in the older than the young adults for all muscles, i.e., TA (absolute difference: 13.8%, P<0.001), GM (4.6%, P=0.034), VL (7.6%, P=0.001), VM (6.7%, P=0.042), BF (6.4%, P<0.001), except for the SOL (0.3%, P=0.248). Finally, the vertical platform acceleration was a significant predictor of the averaged lower limb muscle activity in the young (r=0.917, P<0.001) and older adults (r=0.931, P<0.001). In conclusion, the older population showed greater increases in lower limb muscle activity during WBV exercise than their young counterparts, meaning that they might benefit more from WBV exercises. Additionally, training intensity can be increased by increasing the vertical

Video game players show higher performance but no difference in speed of attention shifts.

PubMed

Mack, David J; Wiesmann, Helene; Ilg, Uwe J

2016-09-01

Video games have become both a widespread leisure activity and a substantial field of research. In a variety of tasks, video game players (VGPs) perform better than non-video game players (NVGPs). This difference is most likely explained by an alteration of the basic mechanisms underlying visuospatial attention. More specifically, the present study hypothesizes that VGPs are able to shift attention faster than NVGPs. Such alterations in attention cannot be disentangled from changes in stimulus-response mappings in reaction time based measurements. Therefore, we used a spatial cueing task with varying cue lead times (CLTs) to investigate the speed of covert attention shifts of 98 male participants divided into 36 NVGPs and 62 VGPs based on their weekly gaming time. VGPs exhibited higher peak and mean performance than NVGPs. However, we did not find any differences in the speed of covert attention shifts as measured by the CLT needed to achieve peak performance. Thus, our results clearly rule out faster stimulus-response mappings as an explanation for the higher performance of VGPs in line with previous studies. More importantly, our data do not support the notion of faster attention shifts in VGPs as another possible explanation. Copyright © 2016 Elsevier B.V. All rights reserved.

Regulation the morphology of cationized gold nanoparticles for effective gene delivery.

PubMed

Zhang, Peng; Li, Bangbang; Du, Jianwei; Wang, Youxiang

2017-09-01

Recent research indicated that the morphology of nanoparticles could result in distinct biological behaviors, thus played an important role in designing efficient gene delivery systems. Among them, gold nanoparticles (AuNPs) with various shapes were widely studied due to the good biocompatibility and easy modification ability. Our recent research indicated that polyethyleneimine-g-bovine serum albumin (BSA-PEI) as non-viral gene vector showed good colloid stability and high transfection efficiency. In this work, BSA-PEI was utilized to modify gold nanospheres (AuNSs) and gold nanorods (AuNRs) to investigate the influence of the morphology on gene delivery. Both AuNS@BSA-PEI and AuNR@BSA-PEI nanoparticles condensed DNA effectively at N/P ratio above 5 and maintained spherical or rod-like morphology respectively. Due to the higher surface charge density at the tips, the rod-like gene complexes were prone to use the tips to contact with cell membrane, which facilitated to be uptaked by HepG2 cells. The endocytosis inhibition experiments showed some differences in the endocytic pathway. Gene transfection experiment showed that the rod-like complexes had almost 100-fold higher of transfection level than that of spherical complexes at the N/P ratio of 20. This work provided a potential strategy for further design of gene vectors with improved transfection results by adjusting the morphology of gene vectors. Copyright © 2017. Published by Elsevier B.V.

Praziquantel in a Clay Nanoformulation Shows More Bioavailability and Higher Efficacy against Murine Schistosoma mansoni Infection

PubMed Central

Mohamed, Wael S.; Nasr, Hanaa E.; El-Lakkany, Naglaa M.; Seif el-Din, Sayed H.; Botros, Sanaa S.

2015-01-01

Consideration of existing compounds always simplifies and shortens the long and difficult process of discovering new drugs specifically for diseases of developing countries, an approach that may add to the significant potential cost savings. This study focused on improving the biological characteristics of the already-existing antischistosomal praziquantel (PZQ) by incorporating it into montmorillonite (MMT) clay as a delivery carrier to overcome its known bioavailability drawbacks. The oral bioavailability of a PZQ-MMT clay nanoformulation and its in vivo efficacy against Schistosoma mansoni were investigated. The PZQ-MMT clay nanoformulation provided a preparation with a controlled release rate, a decrease in crystallinity, and an appreciable reduction in particle size. Uninfected and infected mice treated with PZQ-MMT clay showed 3.61- and 1.96-fold and 2.16- and 1.94-fold increases, respectively, in area under the concentration-time curve from 0 to 8 h (AUC0–8) and maximum concentration of drug in serum (Cmax), with a decrease in elimination rate constant (kel) by 2.84- and 1.35-fold and increases in the absorption rate constant (ka) and half-life (t1/2e) by 2.11- and 1.51-fold and 2.86- and 1.34-fold, respectively, versus the corresponding conventional PZQ-treated groups. This improved bioavailability has been expressed in higher efficacy of the drug, where the dose necessary to kill 50% of the worms was reduced by >3-fold (PZQ 50% effective dose [ED50] was 20.25 mg/kg of body weight for PZQ-MMT clay compared to 74.07 mg/kg for conventional PZQ), with significant reduction in total tissue egg load and increase in total immature, mature, and dead eggs in most of the drug-treated groups. This formulation showed better bioavailability, enhanced antischistosomal efficacy, and a safer profile despite the longer period of residence in the systemic circulation. Although the conventional drug's toxicity was not examined, animal mortality rates were not different

Localization of peroxisome proliferator-activated receptor in mouse and rat-tissues and demonstration of its nuclear translocation in transfected cv-1 cells.

PubMed

Huang, Q; Yeldandi, A; Alvares, K; Ide, H; Reddy, J; Rao, M

1995-02-01

Hepatocarcinogenesis in rodents induced by nongenotoxic peroxisome proliferators is postulated to be a receptor-mediated process. The peroxisome proliferator-activated receptors (PPAR) are members of the steroid hormone receptor superfamily, which participate in ligand-dependent transcriptional activation of peroxisomal fatty acid beta oxidation enzyme system genes in liver parenchymal cells of rats and mice. In order to study the tissue distribution and cellular localization of PPAR, we raised polyclonal antibodies against PPAR using a recombinant rat PPAR (rPPAR) expressed as a glutathione-S-transferase-rPPAR fusion protein. On immunoblot analysis the antibodies specifically recognized a 55 kDa PPAR protein in rat, mouse and human liver homogenates. Immunoblotting also showed that in the mouse and rat, PPAR is expressed in liver, kidney and heart, and only weakly in brain and testis. Immunohistochemical localization in the rat and mouse revealed that PPAR is highly expressed in perivenular (i.e., those surrounding hepatic vein) hepatocytes and very weakly in the cytoplasm of remaining hepatocytes. In the kidney, PPAR was visualized predominantly in the p(3) segments of proximal convoluted tubular epithelium. CV-1 cells transiently transfected with rPPAR cDNA construct showed predominant cytoplasmic fluorescence; treatment of these cells with ciprofibrate, a peroxisome proliferator, resulted in the nuclear translocation of PPAR signal.

Ganas of Showing the Way: A Grounded Theory Study of Hispanic Presidents in Higher Education

ERIC Educational Resources Information Center

Barrios Gutierrez, Eugenio

2010-01-01

In this dissertation, based on classical grounded theory (Glaser & Strauss, 1967, 1971; Glaser, 1978, 1992, 1993, 1994a, 1994b, 1996, 1998, 2001, 2003, 2004), second generation Hispanic presidents and chancellors in higher education were studied to discover how they continually try to resolve second culture-coping challenges, the…

Caveolin Transfection Results in Caveolae Formation but Not Apical Sorting of Glycosylphosphatidylinositol (GPI)-anchored Proteins in Epithelial Cells

PubMed Central

Lipardi, Concetta; Mora, Rosalia; Colomer, Veronica; Paladino, Simona; Nitsch, Lucio; Rodriguez-Boulan, Enrique; Zurzolo, Chiara

1998-01-01

Most epithelial cells sort glycosylphosphatidylinositol (GPI)-anchored proteins to the apical surface. The “raft” hypothesis, based on data mainly obtained in the prototype cell line MDCK, postulates that apical sorting depends on the incorporation of apical proteins into cholesterol/glycosphingolipid (GSL) rafts, rich in the cholesterol binding protein caveolin/VIP21, in the Golgi apparatus. Fischer rat thyroid (FRT) cells constitute an ideal model to test this hypothesis, since they missort both endogenous and transfected GPI- anchored proteins to the basolateral plasma membrane and fail to incorporate them into cholesterol/glycosphingolipid clusters. Because FRT cells lack caveolin, a major component of the caveolar coat that has been proposed to have a role in apical sorting of GPI- anchored proteins (Zurzolo, C., W. Van't Hoff, G. van Meer, and E. Rodriguez-Boulan. 1994. EMBO [Eur. Mol. Biol. Organ.] J. 13:42–53.), we carried out experiments to determine whether the lack of caveolin accounted for the sorting/clustering defect of GPI- anchored proteins. We report here that FRT cells lack morphological caveolae, but, upon stable transfection of the caveolin1 gene (cav1), form typical flask-shaped caveolae. However, cav1 expression did not redistribute GPI-anchored proteins to the apical surface, nor promote their inclusion into cholesterol/GSL rafts. Our results demonstrate that the absence of caveolin1 and morphologically identifiable caveolae cannot explain the inability of FRT cells to sort GPI-anchored proteins to the apical domain. Thus, FRT cells may lack additional factors required for apical sorting or for the clustering with GSLs of GPI-anchored proteins, or express factors that inhibit these events. Alternatively, cav1 and caveolae may not be directly involved in these processes. PMID:9456321

Live Cell Imaging and 3D Analysis of Angiotensin Receptor Type 1a Trafficking in Transfected Human Embryonic Kidney Cells Using Confocal Microscopy.

PubMed

Kadam, Parnika; McAllister, Ryan; Urbach, Jeffrey S; Sandberg, Kathryn; Mueller, Susette C

2017-03-27

Live-cell imaging is used to simultaneously capture time-lapse images of angiotensin type 1a receptors (AT1aR) and intracellular compartments in transfected human embryonic kidney-293 (HEK) cells following stimulation with angiotensin II (Ang II). HEK cells are transiently transfected with plasmid DNA containing AT1aR tagged with enhanced green fluorescent protein (EGFP). Lysosomes are identified with a red fluorescent dye. Live-cell images are captured on a laser scanning confocal microscope after Ang II stimulation and analyzed by software in three dimensions (3D, voxels) over time. Live-cell imaging enables investigations into receptor trafficking and avoids confounds associated with fixation, and in particular, the loss or artefactual displacement of EGFP-tagged membrane receptors. Thus, as individual cells are tracked through time, the subcellular localization of receptors can be imaged and measured. Images must be acquired sufficiently rapidly to capture rapid vesicle movement. Yet, at faster imaging speeds, the number of photons collected is reduced. Compromises must also be made in the selection of imaging parameters like voxel size in order to gain imaging speed. Significant applications of live-cell imaging are to study protein trafficking, migration, proliferation, cell cycle, apoptosis, autophagy and protein-protein interaction and dynamics, to name but a few.

Gossypol inhibition of mitosis, cyclin D1 and Rb protein in human mammary cancer cells and cyclin-D1 transfected human fibrosarcoma cells.

PubMed Central

Ligueros, M.; Jeoung, D.; Tang, B.; Hochhauser, D.; Reidenberg, M. M.; Sonenberg, M.

1997-01-01

The antiproliferative effects of gossypol on human MCF-7 mammary cancer cells and cyclin D1-transfected HT-1060 human fibrosarcoma cells were investigated by cell cycle analysis and effects on the cell cycle regulatory proteins Rb and cyclin D1. Flow cytometry of MCF-7 cells at 24 h indicated that 10 microM gossypol inhibited DNA synthesis by producing a G1/S block. Western blot analysis using anti-human Rb antibodies and anti-human cyclin D1 antibodies in MCF-7 cells and high- and low-expression cyclin D1-transfected fibrosarcoma cells indicated that, after 6 h exposure, gossypol decreased the expression levels of these proteins in a dose-dependent manner. Gossypol also decreased the ratio of phosphorylated to unphosphorylated Rb protein in human mammary cancer and fibrosarcoma cell lines. Gossypol (10 microM) treated also decreased cyclin D1-associated kinase activity on histone H1 used as a substrate in MCF-7 cells. These results suggest that gossypol might suppress growth by modulating the expression of cell cycle regulatory proteins Rb and cyclin D1 and the phosphorylation of Rb protein. Images Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 PMID:9218727

Small RNA Transfection in Primary Human Th17 Cells by Next Generation Electroporation.

PubMed

Montoya, Misty M; Ansel, K Mark

2017-04-13

CD4 + T cells can differentiate into several subsets of effector T helper cells depending on the surrounding cytokine milieu. Th17 cells can be generated from naïve CD4 + T cells in vitro by activating them in the presence of the polarizing cytokines IL-1β, IL-6, IL-23, and TGFβ. Th17 cells orchestrate immunity against extracellular bacteria and fungi, but their aberrant activity has also been associated with several autoimmune and inflammatory diseases. Th17 cells are identified by the chemokine receptor CCR6 and defined by their master transcription factor, RORγt, and characteristic effector cytokine, IL-17A. Optimized culture conditions for Th17 cell differentiation facilitate mechanistic studies of human T cell biology in a controlled environment. They also provide a setting for studying the importance of specific genes and gene expression programs through RNA interference or the introduction of microRNA (miRNA) mimics or inhibitors. This protocol provides an easy to use, reproducible, and highly efficient method for transient transfection of differentiating primary human Th17 cells with small RNAs using a next generation electroporation device.

Aromatase activity modulation by lindane and bisphenol-A in human placental JEG-3 and transfected kidney E293 cells.

PubMed

Nativelle-Serpentini, C; Richard, S; Séralini, G-E; Sourdaine, P

2003-08-01

Aromatase is the cytochrome P-450 involved in converting androgens to estrogens. The cytochrome P-450 family plays a central role in the oxidative metabolism of compounds including environmental pollutants. Since lindane and bisphenol-A (BPA) are two well-characterized endocrine disruptors that have been detected in animals and humans, it was important to learn whether they could affect aromatase activity and consequently estrogen biosynthesis. The present study investigates the effects of BPA and lindane on cytotoxicity, aromatase activity and mRNA levels in human placental JEG-3 cells and transfected human embryonal kidney 293 cells. Both cell lines were exposed to increasing concentrations of lindane (25, 50 and 75 microM) and bisphenol-A (25, 50 and 100 microM) over different time periods (10 min-18 h). As a result, none of these concentrations showed cytotoxicity. After short pre-incubation times (10 min-6 h), aromatase activity was enhanced by both compounds. Longer time incubation (18 h), however, produced dose-related inhibition. Lindane and BPA had no significant effects on CYP19 mRNA levels. Therefore, lindane and BPA modulate aromatase activity suggesting an interaction with the cytochrome P-450 aromatase. This study highlights the endocrine-modulating properties of lindane and bisphenol-A.

Extraocular motoneurons of the adult rat show higher levels of vascular endothelial growth factor and its receptor Flk-1 than other cranial motoneurons.

PubMed

Silva-Hucha, Silvia; Hernández, Rosendo G; Benítez-Temiño, Beatriz; Pastor, Ángel M; de la Cruz, Rosa R; Morcuende, Sara

2017-01-01

Recent studies show a relationship between the deficit of vascular endothelial growth factor (VEGF) and motoneuronal degeneration, such as that occurring in amyotrophic lateral sclerosis (ALS). VEGF delivery protects motoneurons from cell death and delayed neurodegeneration in animal models of ALS. Strikingly, extraocular motoneurons show lesser vulnerability to neurodegeneration in ALS compared to other cranial or spinal motoneurons. Therefore, the present study investigates possible differences in VEGF and its main receptor VEGFR-2 or Flk-1 between extraocular and non-extraocular brainstem motoneurons. We performed immunohistochemistry and Western blot to determine the presence of VEGF and Flk-1 in rat motoneurons located in the three extraocular motor nuclei (abducens, trochlear and oculomotor) and to compare it to that observed in two other brainstem nuclei (hypoglossal and facial) that are vulnerable to degeneration. Extraocular motoneurons presented higher amounts of VEGF and its receptor Flk-1 than other brainstem motoneurons, and thus these molecules could be participating in their higher resistance to neurodegeneration. In conclusion, we hypothesize that differences in VEGF availability and signaling could be a contributing factor to the different susceptibility of extraocular motoneurons, when compared with other motoneurons, in neurodegenerative diseases.

Design and application of cationic amphiphilic β-cyclodextrin derivatives as gene delivery vectors

NASA Astrophysics Data System (ADS)

Wan, Ning; Huan, Meng-Lei; Ma, Xi-Xi; Jing, Zi-Wei; Zhang, Ya-Xuan; Li, Chen; Zhou, Si-Yuan; Zhang, Bang-Le

2017-11-01

The nano self-assembly profiles of amphiphilic gene delivery vectors could improve the density of local cationic head groups to promote their DNA condensation capability and enhance the interaction between cell membrane and hydrophobic tails, thus increasing cellular uptake and gene transfection. In this paper, two series of cationic amphiphilic β-cyclodextrin (β-CD) derivatives were designed and synthesized by using 6-mono-OTs-β-CD (1) as the precursor to construct amphiphilic gene vectors with different building blocks in a selective and controlled manner. The effect of different type and degree of cationic head groups on transfection and the endocytic mechanism of β-CD derivatives/DNA nanocomplexes were also investigated. The results demonstrated that the designed β-cyclodextrin derivatives were able to compact DNA to form stable nanocomplexes and exhibited low cytotoxicity. Among them, PEI-1 with PEI head group showed enhanced transfection activity, significantly higher than commercially available agent PEI25000 especially in the presence of serum, showing potential application prospects in clinical trials. Moreover, the endocytic uptake mechanism involved in the gene transfection of PEI-1 was mainly through caveolae-mediated endocytosis, which could avoid the lysosomal degradation of loaded gene, and had great importance for improving gene transfection activity.

Design and application of cationic amphiphilic β-cyclodextrin derivatives as gene delivery vectors.

PubMed

Wan, Ning; Huan, Meng-Lei; Ma, Xi-Xi; Jing, Zi-Wei; Zhang, Ya-Xuan; Li, Chen; Zhou, Si-Yuan; Zhang, Bang-Le

2017-11-17

The nano self-assembly profiles of amphiphilic gene delivery vectors could improve the density of local cationic head groups to promote their DNA condensation capability and enhance the interaction between cell membrane and hydrophobic tails, thus increasing cellular uptake and gene transfection. In this paper, two series of cationic amphiphilic β-cyclodextrin (β-CD) derivatives were designed and synthesized by using 6-mono-OTs-β-CD (1) as the precursor to construct amphiphilic gene vectors with different building blocks in a selective and controlled manner. The effect of different type and degree of cationic head groups on transfection and the endocytic mechanism of β-CD derivatives/DNA nanocomplexes were also investigated. The results demonstrated that the designed β-cyclodextrin derivatives were able to compact DNA to form stable nanocomplexes and exhibited low cytotoxicity. Among them, PEI-1 with PEI head group showed enhanced transfection activity, significantly higher than commercially available agent PEI25000 especially in the presence of serum, showing potential application prospects in clinical trials. Moreover, the endocytic uptake mechanism involved in the gene transfection of PEI-1 was mainly through caveolae-mediated endocytosis, which could avoid the lysosomal degradation of loaded gene, and had great importance for improving gene transfection activity.

A new human mast cell line expressing a functional IgE receptor converts to tumorigenic growth by KIT D816V transfection.

PubMed

Saleh, Rosine; Wedeh, Ghaith; Herrmann, Harald; Bibi, Siham; Cerny-Reiterer, Sabine; Sadovnik, Irina; Blatt, Katharina; Hadzijusufovic, Emir; Jeanningros, Sylvie; Blanc, Catherine; Legarff-Tavernier, Magali; Chapiro, Elise; Nguyen-Khac, Florence; Subra, Frédéric; Bonnemye, Patrick; Dubreuil, Patrice; Desplat, Vanessa; Merle-Béral, Hélène; Willmann, Michael; Rülicke, Thomas; Valent, Peter; Arock, Michel

2014-07-03

In systemic mastocytosis (SM), clinical problems arise from factor-independent proliferation of mast cells (MCs) and the increased release of mediators by MCs, but no human cell line model for studying MC activation in the context of SM is available. We have created a stable stem cell factor (SCF) -dependent human MC line, ROSA(KIT WT), expressing a fully functional immunoglobulin E (IgE) receptor. Transfection with KIT D816V converted ROSA(KIT WT) cells into an SCF-independent clone, ROSA(KIT D816V), which produced a mastocytosis-like disease in NSG mice. Although several signaling pathways were activated, ROSA(KIT D816V) did not exhibit an increased, but did exhibit a decreased responsiveness to IgE-dependent stimuli. Moreover, NSG mice bearing ROSA(KIT D816V)-derived tumors did not show mediator-related symptoms, and KIT D816V-positive MCs obtained from patients with SM did not show increased IgE-dependent histamine release or CD63 upregulation. Our data show that KIT D816V is a disease-propagating oncoprotein, but it does not activate MCs to release proinflammatory mediators, which may explain why mediator-related symptoms in SM occur preferentially in the context of a coexisting allergy. ROSA(KIT D816V) may provide a valuable tool for studying the pathogenesis of mastocytosis and should facilitate the development of novel drugs for treating SM patients. © 2014 by The American Society of Hematology.

Autotetraploids of Vicia cracca show a higher allelic richness in natural populations and a higher seed set after artificial selfing than diploids

PubMed Central

Eliášová, Anežka; Trávníček, Pavel; Mandák, Bohumil; Münzbergová, Zuzana

2014-01-01

Background and Aims Despite the great importance of autopolyploidy in the evolution of angiosperms, relatively little attention has been devoted to autopolyploids in natural polyploid systems. Several hypotheses have been proposed to explain why autopolyploids are so common and successful, for example increased genetic diversity and heterozygosity and the transition towards selfing. However, case studies on patterns of genetic diversity and on mating systems in autopolyploids are scarce. In this study allozymes were employed to investigate the origin, population genetic diversity and mating system in the contact zone between diploid and assumed autotetraploid cytotypes of Vicia cracca in Central Europe. Methods Four enzyme systems resolved in six putative loci were investigated in ten diploid, ten tetraploid and five mixed-ploidy populations. Genetic diversity and heterozygosity, partitioning of genetic diversity among populations and cytotypes, spatial genetic structure and fixed heterozygosity were analysed. These studies were supplemented by a pollination experiment and meiotic chromosome observation. Key Results and Conclusions Weak evidence of fixed heterozygosity, a low proportion of unique alleles and genetic variation between cytotypes similar to the variation among populations within cytotypes supported the autopolyploid origin of tetraploids, although no multivalent formation was observed. Tetraploids possessed more alleles than diploids and showed higher observed zygotic heterozygosity than diploids, but the observed gametic heterozygosity was similar to the value observed in diploids and smaller than expected under panmixis. Values of the inbreeding coefficient and differentiation among populations (ρST) suggested that the breeding system in both cytotypes of V. cracca is mixed mating with prevailing outcrossing. The reduction in seed production of tetraploids after selfing was less than that in diploids. An absence of correlation between genetic and

Apollo Lunar Astronauts Show Higher Cardiovascular Disease Mortality: Possible Deep Space Radiation Effects on the Vascular Endothelium

PubMed Central

Delp, Michael D.; Charvat, Jacqueline M.; Limoli, Charles L.; Globus, Ruth K.; Ghosh, Payal

2016-01-01

As multiple spacefaring nations contemplate extended manned missions to Mars and the Moon, health risks could be elevated as travel goes beyond the Earth’s protective magnetosphere into the more intense deep space radiation environment. The primary purpose of this study was to determine whether mortality rates due to cardiovascular disease (CVD), cancer, accidents and all other causes of death differ in (1) astronauts who never flew orbital missions in space, (2) astronauts who flew only in low Earth orbit (LEO), and (3) Apollo lunar astronauts, the only humans to have traveled beyond Earth’s magnetosphere. Results show there were no differences in CVD mortality rate between non-flight (9%) and LEO (11%) astronauts. However, the CVD mortality rate among Apollo lunar astronauts (43%) was 4–5 times higher than in non-flight and LEO astronauts. To test a possible mechanistic basis for these findings, a secondary purpose was to determine the long-term effects of simulated weightlessness and space-relevant total-body irradiation on vascular responsiveness in mice. The results demonstrate that space-relevant irradiation induces a sustained vascular endothelial cell dysfunction. Such impairment is known to lead to occlusive artery disease, and may be an important risk factor for CVD among astronauts exposed to deep space radiation. PMID:27467019

Apollo Lunar Astronauts Show Higher Cardiovascular Disease Mortality: Possible Deep Space Radiation Effects on the Vascular Endothelium.

PubMed

Delp, Michael D; Charvat, Jacqueline M; Limoli, Charles L; Globus, Ruth K; Ghosh, Payal

2016-07-28

As multiple spacefaring nations contemplate extended manned missions to Mars and the Moon, health risks could be elevated as travel goes beyond the Earth's protective magnetosphere into the more intense deep space radiation environment. The primary purpose of this study was to determine whether mortality rates due to cardiovascular disease (CVD), cancer, accidents and all other causes of death differ in (1) astronauts who never flew orbital missions in space, (2) astronauts who flew only in low Earth orbit (LEO), and (3) Apollo lunar astronauts, the only humans to have traveled beyond Earth's magnetosphere. Results show there were no differences in CVD mortality rate between non-flight (9%) and LEO (11%) astronauts. However, the CVD mortality rate among Apollo lunar astronauts (43%) was 4-5 times higher than in non-flight and LEO astronauts. To test a possible mechanistic basis for these findings, a secondary purpose was to determine the long-term effects of simulated weightlessness and space-relevant total-body irradiation on vascular responsiveness in mice. The results demonstrate that space-relevant irradiation induces a sustained vascular endothelial cell dysfunction. Such impairment is known to lead to occlusive artery disease, and may be an important risk factor for CVD among astronauts exposed to deep space radiation.

Synergistic promoting effects of bone morphogenetic protein 12/connective tissue growth factor on functional differentiation of tendon derived stem cells and patellar tendon window defect regeneration.

PubMed

Xu, Kang; Sun, Yanjun; Kh Al-Ani, Mohanad; Wang, Chunli; Sha, Yongqiang; Sung, Kl Paul; Dong, Nianguo; Qiu, Xuefeng; Yang, Li

2018-01-03

Current study investigated bone morphogenetic protein 12 (BMP12) and connective tissue growth factor (CTGF) activate tendon derived stem cells (TDSCs) tenogenic differentiation, and promotion of injured tendon regeneration. TDSCs were transfected with BMP12 and CTGF via recombinant adenovirus (Ad) infection. Gene transfection efficiency, cell viability and cytotoxicity, tenogenic gene expression, collagen I/III synthesis were evaluated in vitro. For the in vivo study, the transfected cells were transplanted into the rat patellar tendon window defect. At weeks 2 and 8 of post-surgery, the repaired tendon tissues were harvested for histological and biomechanical examinations. The transfected TDSCs revealed relatively stable transfection efficiency (80-90%) with active cell viability means while rare cytotoxicity in each group. During days 1 and 5, BMP12 and CTGF transfection caused tenogenic differentiation genes activation in TDSCs: type I/III collagen, tenascin-C, and scleraxis were all up-regulated, whereas osteogenic, adipogenic, and chondrogenic markers were all down-regulated respectively. In addition, BMP12 and CTGF overexpression significantly promote type I/III collagen synthesis. After in vivo transplantation, at 2 and 8 weeks post-surgery, BMP12, CTGF and co-transfection groups showed more integrated tendon tissue structure versus control, meanwhile, the ultimate failure loads and Young's were all higher than control. Remarkably, at 8 weeks post-surgery, the biomechanical properties of co-transfection group was approaching to normal rat patellar tendon, moreover, the ratio of type III/I collagen maintained about 20% in each transfection group, meanwhile, the type I collagen were significantly increased with co-transfection treatment. In conclusion, BMP12 and CTGF transfection stimulate tenogenic differentiation of TDSCs. The synergistic effects of simultaneous transfection of both may significantly promoted rat patellar tendon window defect

AMT1;1 transgenic rice plants with enhanced NH4 + permeability show superior growth and higher yield under optimal and suboptimal NH4 + conditions

PubMed Central

Rothstein, Steven J.

2014-01-01

The major source of nitrogen for rice (Oryza sativa L.) is ammonium (NH4 +). The NH4 + uptake of roots is mainly governed by membrane transporters, with OsAMT1;1 being a prominent member of the OsAMT1 gene family that is known to be involved in NH4 + transport in rice plants. However, little is known about its involvement in NH4 + uptake in rice roots and subsequent effects on NH4 + assimilation. This study shows that OsAMT1;1 is a constitutively expressed, nitrogen-responsive gene, and its protein product is localized in the plasma membrane. Its expression level is under the control of circadian rhythm. Transgenic rice lines (L-2 and L-3) overexpressing the OsAMT1;1 gene had the same root structure as the wild type (WT). However, they had 2-fold greater NH4 + permeability than the WT, whereas OsAMT1;1 gene expression was 20-fold higher than in the WT. Analogous to the expression, transgenic lines had a higher NH4 + content in the shoots and roots than the WT. Direct NH4 + fluxes in the xylem showed that the transgenic lines had significantly greater uptake rates than the WT. Higher NH4 + contents also promoted higher expression levels of genes in the nitrogen assimilation pathway, resulting in greater nitrogen assimilates, chlorophyll, starch, sugars, and grain yield in transgenic lines than in the WT under suboptimal and optimal nitrogen conditions. OsAMT1;1 also enhanced overall plant growth, especially under suboptimal NH4 + levels. These results suggest that OsAMT1;1 has the potential for improving nitrogen use efficiency, plant growth, and grain yield under both suboptimal and optimal nitrogen fertilizer conditions. PMID:24420570

AMT1;1 transgenic rice plants with enhanced NH4(+) permeability show superior growth and higher yield under optimal and suboptimal NH4(+) conditions.

PubMed

Ranathunge, Kosala; El-Kereamy, Ashraf; Gidda, Satinder; Bi, Yong-Mei; Rothstein, Steven J

2014-03-01

The major source of nitrogen for rice (Oryza sativa L.) is ammonium (NH4(+)). The NH4(+) uptake of roots is mainly governed by membrane transporters, with OsAMT1;1 being a prominent member of the OsAMT1 gene family that is known to be involved in NH4(+) transport in rice plants. However, little is known about its involvement in NH4(+) uptake in rice roots and subsequent effects on NH4(+) assimilation. This study shows that OsAMT1;1 is a constitutively expressed, nitrogen-responsive gene, and its protein product is localized in the plasma membrane. Its expression level is under the control of circadian rhythm. Transgenic rice lines (L-2 and L-3) overexpressing the OsAMT1;1 gene had the same root structure as the wild type (WT). However, they had 2-fold greater NH4(+) permeability than the WT, whereas OsAMT1;1 gene expression was 20-fold higher than in the WT. Analogous to the expression, transgenic lines had a higher NH4(+) content in the shoots and roots than the WT. Direct NH4(+) fluxes in the xylem showed that the transgenic lines had significantly greater uptake rates than the WT. Higher NH4(+) contents also promoted higher expression levels of genes in the nitrogen assimilation pathway, resulting in greater nitrogen assimilates, chlorophyll, starch, sugars, and grain yield in transgenic lines than in the WT under suboptimal and optimal nitrogen conditions. OsAMT1;1 also enhanced overall plant growth, especially under suboptimal NH4(+) levels. These results suggest that OsAMT1;1 has the potential for improving nitrogen use efficiency, plant growth, and grain yield under both suboptimal and optimal nitrogen fertilizer conditions.

Exploring the Solid State Properties of Enzymatic Poly(amine-co-ester) Terpolymers to Expand their Applications in Gene Transfection.

PubMed

Voevodina, Irina; Scandola, Mariastella; Zhang, Junwei; Jiang, Zhaozhong

2014-01-01

Polymers bearing amino functional groups are an important class of materials capable of serving as non-viral carriers for DNA delivery to living cells. In this work biodegradable poly(amine- co -ester) terpolymers were synthesized via ring-opening and polycondensation copolymerization of lactone (ε-caprolactone (CL), ω-dodecalactone, ω-pentadecalactone (PDL), and ω-hexadecalactone) with diethyl sebacate (DES) and N-methyldiethanolamine (MDEA) in diphenyl ether, catalyzed by Candida antarctica lipase B (CALB). All lactone-DES-MDEA terpolymers had random distributions of lactone, sebacate, MDEA repeat units in the polymer chains. PDL-DES-MDEA terpolymers were studied in the composition range from 21 mol% to 90 mol% PDL whereas the terpolymers with other lactones were investigated at a single composition (80 mol% lactone). DSC and WAXS analyses showed that all investigated terpolymers crystallize in their respective homopolylactone crystal lattice. Terpolymers with large lactones and a high lactone content melt well above room temperature and are hard solids, whereas terpolymers with small lactones (e.g. CL) or with a low lactone content melt below/around ambient temperature and are waxy/gluey materials. Given the importance of hydrophobicity in influencing gene delivery, water contact angle measurements were carried out on lactone-DES-MDEA terpolymers showing that it is possible to tune the hydrophilic-to-hydrophobic balance by varying polymer composition and size of lactone units. To demonstrate the feasibility of using solid terpolymers as nanocarriers for DNA delivery, PDL-DES-MDEA copolymers with 65-90% PDL were successfully transformed into free-standing nanoparticles with average particle size ranging from 163 to 175 nm. Our preliminary results showed that LucDNA-loaded nanoparticles of the terpolymer with 65% PDL were effective for luciferase gene transfection of HEK293 cells.

Exploring the Solid State Properties of Enzymatic Poly(amine-co-ester) Terpolymers to Expand their Applications in Gene Transfection

PubMed Central

Voevodina, Irina; Scandola, Mariastella; Zhang, Junwei; Jiang, Zhaozhong

2014-01-01

Polymers bearing amino functional groups are an important class of materials capable of serving as non-viral carriers for DNA delivery to living cells. In this work biodegradable poly(amine-co-ester) terpolymers were synthesized via ring-opening and polycondensation copolymerization of lactone (ε-caprolactone (CL), ω-dodecalactone, ω-pentadecalactone (PDL), and ω-hexadecalactone) with diethyl sebacate (DES) and N-methyldiethanolamine (MDEA) in diphenyl ether, catalyzed by Candida antarctica lipase B (CALB). All lactone-DES-MDEA terpolymers had random distributions of lactone, sebacate, MDEA repeat units in the polymer chains. PDL-DES-MDEA terpolymers were studied in the composition range from 21 mol% to 90 mol% PDL whereas the terpolymers with other lactones were investigated at a single composition (80 mol% lactone). DSC and WAXS analyses showed that all investigated terpolymers crystallize in their respective homopolylactone crystal lattice. Terpolymers with large lactones and a high lactone content melt well above room temperature and are hard solids, whereas terpolymers with small lactones (e.g. CL) or with a low lactone content melt below/around ambient temperature and are waxy/gluey materials. Given the importance of hydrophobicity in influencing gene delivery, water contact angle measurements were carried out on lactone-DES-MDEA terpolymers showing that it is possible to tune the hydrophilic-to-hydrophobic balance by varying polymer composition and size of lactone units. To demonstrate the feasibility of using solid terpolymers as nanocarriers for DNA delivery, PDL-DES-MDEA copolymers with 65–90% PDL were successfully transformed into free-standing nanoparticles with average particle size ranging from 163 to 175 nm. Our preliminary results showed that LucDNA-loaded nanoparticles of the terpolymer with 65% PDL were effective for luciferase gene transfection of HEK293 cells. PMID:24683469

Evaluation and mechanism studies of PEGylated dendrigraft poly-L-lysines as novel gene delivery vectors.

PubMed

Huang, Rongqin; Liu, Shuhuan; Shao, Kun; Han, Liang; Ke, Weilun; Liu, Yang; Li, Jianfeng; Huang, Shixian; Jiang, Chen

2010-07-02

Dendrimers have attracted great interest in the field of gene delivery due to their synthetic controllability and excellent gene transfection efficiency. In this work, dendrigraft poly-L-lysines (DGLs) were evaluated as a novel gene vector for the first time. Derivatives of DGLs (generation 2 and 3) with different extents of PEGylation were successfully synthesized and used to compact pDNA as complexes. The result of gel retardation assay showed that pDNA could be effectively packed by all the vectors at a DGLs to pDNA weight ratio greater than 2. An increase in the PEGylation extent of vectors resulted in a decrease in the incorporation efficiency and cytotoxicity of complexes in 293 cells, which also decreased the zeta potential a little but did not affect the mean diameter of complexes. Higher generation of DGLs could mediate higher gene transfection in vitro. Confocal microscopy and cellular uptake inhibition studies demonstrated that caveolae-mediated process and macropinocytosis were involved in the cellular uptake of DGLs-based complexes. Also the results indicate that proper PEGylated DGLs could mediate efficient gene transfection, showing their potential as an alternate biodegradable vector in the field of nonviral gene delivery.

Speed versus endurance tradeoff in plants: Leaves with higher photosynthetic rates show stronger seasonal declines

PubMed Central

Zhang, Yong-Jiang; Sack, Lawren; Cao, Kun-Fang; Wei, Xue-Mei; Li, Nan

2017-01-01

We tested for a tradeoff across species between plant maximum photosynthetic rate and the ability to maintain photosynthesis under adverse conditions in the unfavorable season. Such a trade-off would be consistent with the observed trade-off between maximum speed and endurance in athletes and some animals that has been explained by cost-benefit theory. This trend would have importance for the general understanding of leaf design, and would simplify models of annual leaf carbon relations. We tested for such a trade-off using a database analysis across vascular plants and using an experimental approach for 29 cycad species, representing an ancient plant lineage with diversified evergreen leaves. In both tests, a higher photosynthetic rate per mass or per area in the favorable season was associated with a stronger absolute or percent decline in the unfavorable season. We resolved a possible mechanism based on biomechanics and nitrogen allocation; cycads with high leaf toughness (leaf mass per area) and higher investment in leaf construction than in physiological function (C/N ratio) tended to have lower warm season photosynthesis but less depression in the cool season. We propose that this trade-off, consistent with cost-benefit theory, represents a significant physio-phenological constraint on the diversity and seasonal dynamics of photosynthetic rate. PMID:28186201

Induction of anti-melanoma CTL response using DC transfected with mutated mRNA encoding full-length Melan-A/MART-1 antigen with an A27L amino acid substitution.

PubMed

Abdel-Wahab, Zeinab; Kalady, Matthew F; Emani, Sirisha; Onaitis, Mark W; Abdel-Wahab, Omar I; Cisco, Robin; Wheless, Lee; Cheng, Tsung-Yen; Tyler, Douglas S; Pruitt, Scott K

2003-08-01

Modification of the parental immunodominant Melan-A/MART-1 peptide (MART-1(26-35)) by replacing the alanine with leucine (A27L) enhances its immunogenicity. Because of the reported advantages of RNA over peptides in DC vaccines, we sought to mutate the MART-1 gene to encode a full-length MART-1 antigen with an A27L amino acid substitution. Human DC were transfected with A27L-mutated MART-1 RNA (A27L RNA) or native MART-1 RNA, and then used to stimulate autologous T cells from a series of 8 HLA-A2+ volunteers. After three stimulations, all CTL induced with DC/A27L RNA exhibited more tetramer+ cells, and demonstrated stronger antigen-specific IFNgamma-secreting activity compared to CTL induced with DC/native RNA. A potent MART-1-specific, and predominantly class-I-restricted lysis was detected in most CTL induced with DC/A27L RNA, while native RNA-induced CTL showed minimal and non-specific lysis. HLA-A2+ DC and MART-1 negative/A2+ melanoma cells transfected with the A27L RNA were recognized and killed by MART-1-specific CTL, suggesting that these APC efficiently processed the A27L RNA and presented correct MART-1-specific epitope(s). In summary, introducing an A27L mutation into the MART-1 full-length mRNA sequence enhanced the immunogenicity of the encoded MART-1 Ag. The ease with which such a mutation can be made in RNA presents another potential advantage of using RNA for immunotherapy. Our results support considering this strategy for enhancing the immunogenicity of DC-based RNA vaccines.

Novel cancer vaccines prepared by anchoring cytokines to tumor cells avoiding gene transfection

NASA Astrophysics Data System (ADS)

Nizard, Philippe; Gross, David-Alexandre; Chenal, Alexandre; Beaumelle, Bruno; Kosmatopoulos, Konstadinos; Gillet, Daniel

2002-06-01

Cytokines have a strong potential for triggering anticancer immunity if released in the tumor microenvironment. Successful vaccines have been engineered using tumor cells genetically modified to secrete the cytokines. Unfortunately, this approach remains difficult and hazardous to perform in the clinic. We describe a new way of combining cytokines with tumor cells to prepare anticancer vaccines. This consists in anchoring recombinant cytokines to the membrane of killed tumor cells. Attachment is mediated by a fragment of diphtheria toxin (T) genetically connected to the cytokine. It is triggered by an acid pH pulse. The method was applied to IL-2, a potent anti-tumor cytokine. IL-2 anchored to the surface of tumor cells by the T anchor retained its IL-2 activity and remained exposed several days. Interestingly, vaccination of mice with these modified tumor cells induced a protective anti-tumor immunity mediated by tumor-specific cytotoxic T lymphocytes. This procedure presents several advantages as compared to the conventional approaches based on the transfection of tumor cells with cytokine genes. It does not require the culture of tumor cells from the patients and eliminates the safety problems connected with viral vectors while allowing the control of the amount of cytokines delivered with the vaccine.

MET signalling in primary colon epithelial cells leads to increased transformation irrespective of aberrant Wnt signalling

PubMed Central

Boon, E M J; Kovarikova, M; Derksen, P W B; van der Neut, R

2005-01-01

It has been shown that in hereditary and most sporadic colon tumours, components of the Wnt pathway are mutated. The Wnt target MET has been implicated in the development of colon cancer. Here, we show that overexpression of wild-type or a constitutively activated form of MET in colon epithelial cells leads to increased transformation irrespective of Wnt signalling. Fetal human colon epithelial cells without aberrant Wnt signalling were transfected with wild-type or mutated MET constructs. Expression of these constructs leads to increased phosphorylation of MET and its downstream targets PKB and MAPK. Upon stimulation with HGF, the expression of E-cadherin is downregulated in wild-type MET-transfected cells, whereas cells expressing mutated MET show low E-cadherin levels independent of stimulation with ligand. This implies a higher migratory propensity of these cells. Furthermore, fetal human colon epithelial cells expressing the mutated form of MET have colony-forming capacity in soft agar, while cells expressing wild-type MET show an intermediate phenotype. Subcutaneous injection of mutated MET-transfected cells in nude mice leads to the formation of tumours within 12 days in all mice injected. At this time point, mock-transfected cells do not form tumours, while wild-type MET-transfected cells form subcutaneous tumours in one out of five mice. We thus show that MET signalling can lead to increased transformation of colon epithelial cells independent of Wnt signalling and in this way could play an essential role in the onset and progression of colorectal cancer. PMID:15785735

Development of a slow non-viral DNA release system from PDLLA scaffolds fabricated using a supercritical CO2 technique.

PubMed

Heyde, Mieke; Partridge, Kris A; Howdle, Steven M; Oreffo, Richard O C; Garnett, Martin C; Shakesheff, Kevin M

2007-10-15

Polyamidoamine polymers (PAA) comprising methylene-bisacrylamide/dimethylethylene-diamine monomers were synthesized, complexed with DNA and incorporated into porous P(DL)LA scaffolds by using a supercritical CO(2) (scCO(2)) technique. Scaffolds were made in a dry state consequently there was a need to lyophilize the complexes. A statistically significant reduction of the transfection efficiency was observed in the absence of trehalose when compared to the original complex after freeze-drying. Increasing concentrations (0-10% w/v) of trehalose were added to the complex prior to freeze-drying. Structure dependent differences in DNA binding were evaluated by gel electrophoresis and thermal transition analysis. TEM and PCS showed aggregate formation after freeze-drying without trehalose. Scaffolds were characterized by pore sizes of 173 +/- 73 microm and a porosity of 71%. The transfection potential of the released DNA was investigated by seeding scaffolds with A549 cells and following firefly luciferase as a marker gene after 48 h exposure. Low but continuous levels of transfection were observed for PAA complexes during a 60-day study. Complexes made with Lipofectaminetrade mark gave initially higher levels of DNA release but no further expression was seen after 40 days. Uncomplexed DNA showed background levels of transfection. Culturing cells on 3D scaffolds showed a benefit in retention of transfection activity with time compared to 2D controls. Transfection levels could be increased when cells were grown in OptiMEM. This study demonstrated that PAA/DNA complexes incorporated into a P(DL)LA scaffold made by using scCO(2) processing exhibited a slow release and extended gene expression profile. Copyright 2007 Wiley Periodicals, Inc.

Approach to Rapid Synthesis and Functionalization of Iron Oxide Nanoparticles for High Gene Transfection.

PubMed

Stephen, Zachary R; Dayringer, Christopher J; Lim, Josh J; Revia, Richard A; Halbert, Mackenzie V; Jeon, Mike; Bakthavatsalam, Arvind; Ellenbogen, Richard G; Zhang, Miqin

2016-03-01

Surface functionalization of theranostic nanoparticles (NPs) typically relies on lengthy, aqueous postsynthesis labeling chemistries that have limited ability to fine-tune surface properties and can lead to NP heterogeneity. The need for a rapid, simple synthesis approach that can provide great control over the display of functional moieties on NP surfaces has led to increased use of highly selective bioorthoganol chemistries including metal-affinity coordination. Here we report a simple approach for rapid production of a superparamagnetic iron oxide NPs (SPIONs) with tunable functionality and high reproducibility under aqueous conditions. We utilize the high affinity complex formed between catechol and Fe((III)) as a means to dock well-defined catechol modified polymer modules on the surface of SPIONs during sonochemical coprecipitation synthesis. Polymer modules consisted of chitosan and poly(ethylene glycol) (PEG) copolymer (CP) modified with catechol (CCP), and CCP functionalized with cationic polyethylenimine (CCP-PEI) to facilitate binding and delivery of DNA for gene therapy. This rapid synthesis/functionalization approach provided excellent control over the extent of PEI labeling, improved SPION magnetic resonance imaging (MRI) contrast enhancement and produced an efficient transfection agent.

A polyethylenimine-mimetic biodegradable polycation gene vector and the effect of amine composition in transfection efficiency.

PubMed

Shen, J; Zhao, D J; Li, W; Hu, Q L; Wang, Q W; Xu, F J; Tang, G P

2013-06-01

The low toxicity and efficient gene delivery of polymeric vectors remain the major barrier to the clinical application of non-viral gene therapy. Here, we present a poly-D, L-succinimide (PSI)-based biodegradable cationic polymer which mimicked the golden standard, branched polyethylenimine (PEI, ~25 kDa). To investigate the influence of 1°, 2°, 3° amine group ratio in the polymer, a series of PSI-based vectors (PSI-NN'x-NNy) grafted with different amine side chains of N,N-dimethyldipropylenetriamine (NN') and bis(3-aminopropyl)amine (NN) were first characterized and contrasted by biophysical measurements. The in vitro and in vivo biological assay demonstrated that PSI-NN'0.85-NN1 exhibited better transfection ability and biocompatibility than PEI. The present results suggest that such PEI-mimic biodegradable PSI-NN'0.85-NN1 possesses a good potential application for clinical gene delivery. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

Wu, Li-An; Department of Pediatric Dentistry, School of Stomatology, The Fourth Military Medical University, Xi-an; Yuan, Guohua

Generation of a floxed Bmp2/4 osteoblast cell line is a valuable tool for studying the modulatory effects of Bmp2 and Bmp4 on osteoblast differentiation as well as relevant molecular events. In this study, primary floxed Bmp2/4 mouse osteoblasts were cultured and transfected with simian virus 40 large T-antigen. Transfection was verified by polymerase chain reaction (PCR) and immunohistochemistry. To examine the characteristics of the transfected cells, morphology, proliferation and mineralization were analyzed, expression of cell-specific genes including Runx2, ATF4, Dlx3, Osx, dentin matrix protein 1, bone sialoprotein, osteopontin, osteocalcin, osteonectin and collagen type I was detected. These results show thatmore » transfected floxed Bmp2/4 osteoblasts bypassed senescence with a higher proliferation rate, but retain the genotypic and phenotypic characteristics similar to the primary cells. Thus, we for the first time demonstrate the establishment of an immortalized mouse floxed Bmp2/4 osteoblast cell line.« less

Poly(β-amino amine) cross-linked PEIs as highly efficient gene vectors.

PubMed

Deng, Ji-Zhe; Sun, Yun-Xia; Wang, Hui-Yuan; Li, Cao; Huang, Fu-Wei; Cheng, Si-Xue; Zhuo, Ren-Xi; Zhang, Xian-Zheng

2011-05-01

To increase the release of DNA into the cytoplasm and further improve transgene expression of nucleic acid novel polymeric gene carriers were prepared which would be biodegradable under the reducing conditions in the cytoplasm. Disulfide-containing poly(β-amino amine)s were first synthesized and then used to cross-link low molecular weight polyethyleneimine (1800 Da) through Michael addition to obtain SS-PBAA-PEIs as the final gene carriers. The physicochemical characteristics of SS-PBAA-PEI/DNA complexes were characterized. In vitro transfection mediated by the SS-PBAA-PEIs under serum conditions was carried out. Cell uptake of the gene delivery systems was observed by confocal laser scanning microscopy. The results of the physicochemical characterisation demonstrated that the SS-PBAA-PEIs could efficiently condense DNA. In vitro transfection under serum conditions showed that SS-PBAA-PEIs had comparable or even higher transfection efficiencies than 25 kDa PEI. And SS-PBAA-PEIs showed much lower cytotoxicity compared with 25 kDa PEI. In summary, the SS-PBAA-PEIs possess great potential as non-viral gene vectors and exhibit high transfection efficiency under serum conditions. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Tailoring charge density and hydrogen bonding of imidazolium copolymers for efficient gene delivery.

PubMed

Allen, Michael H; Green, Matthew D; Getaneh, Hiwote K; Miller, Kevin M; Long, Timothy E

2011-06-13

Conventional free radical polymerization with subsequent postpolymerization modification afforded imidazolium copolymers with controlled charge density and side chain hydroxyl number. Novel imidazolium-containing copolymers where each permanent cation contained one or two adjacent hydroxyls allowed precise structure-transfection efficiency studies. The degree of polymerization was identical for all copolymers to eliminate the influence of molecular weight on transfection efficiency. DNA binding, cytotoxicity, and in vitro gene transfection in African green monkey COS-7 cells revealed structure-property-transfection relationships for the copolymers. DNA gel shift assays indicated that higher charge densities and hydroxyl concentrations increased DNA binding. As the charge density of the copolymers increased, toxicity of the copolymers also increased; however, as hydroxyl concentration increased, cytotoxicity remained constant. Changing both charge density and hydroxyl levels in a systematic fashion revealed a dramatic influence on transfection efficiency. Dynamic light scattering of the polyplexes, which were composed of copolymer concentrations required for the highest luciferase expression, showed an intermediate DNA-copolymer binding affinity. Our studies supported the conclusion that cationic copolymer binding affinity significantly impacts overall transfection efficiency of DNA delivery vehicles, and the incorporation of hydroxyl sites offers a less toxic and effective alternative to more conventional highly charged copolymers.

The Lcn2-engineered HEK-293 cells show senescence under stressful condition

PubMed Central

Bahmani, Bahareh; Amiri, Fatemeh; Mohammadi Roushandeh, Amaneh; Bahadori, Marzie; Harati, Mozhgan Dehghan; Habibi Roudkenar, Mehryar

2015-01-01

Objective(s): Lipocalin2 (Lcn2) gene is highly expressed in response to various types of cellular stresses. The precise role of Lcn2 has not been fully understood yet. However, it plays a key role in controlling vital cellular processes such as proliferation, apoptosis and metabolism. Recently it was shown that Lcn2 decreases senescence and increases proliferation of mesenchymal stem cells (MSC) with finite life span under either normal or oxidative stress conditions. However, Lcn2 effects on immortal cell line with infinite proliferation are not defined completely. Materials and Materials and Methods: HEK-293 cells were transfected with recombinant pcDNA3.1 containing Lcn2 fragment (pcDNA3.1-Lcn2). Expression of lipocalin2 in transfected cells was evaluated by RT-PCR, real time RT-PCR, and ELISA. Different cell groups were treated with H2O2 and WST-1 assay was performed to determine their proliferation rate. Senescence was studied by β-galactosidase and gimsa staining methods as well as evaluation of the expression of senescence-related genes by real time RT-PCR. Results: Lcn2 increased cell proliferation under normal culture condition, while the proliferation slightly decreased under oxidative stress. This decrease was further found to be attributed to senescence. Conclusion: Our findings indicated that under harmful conditions, Lcn2 gene is responsible for the regulation of cell survival through senescence. PMID:26124931

Different Types of Luciferase Reporters Show Distinct Susceptibility to T3-Evoked Downregulation.

PubMed

Kollár, Anna; Kvárta-Papp, Zsuzsanna; Egri, Péter; Gereben, Balázs

2016-01-01

The firefly luciferase reporter protein is a crucial tool for studies targeting a broad range of biological questions. Importantly, luciferase assays are also widely used to explore mechanisms underlying thyroid hormone dependent regulation of gene expression. However, it was demonstrated that the firefly luciferase reporter is subject to triiodothyronine (T3)-evoked, promoter independent downregulation that is mediated by the thyroid hormone receptor. Since this effect can interfere with readout accuracy, the study aimed to find luciferase reporters that are not susceptible to this phenomenon. Luciferase reporter constructs were generated under the control of a minimal thymidine kinase (TK) promoter and transiently transfected into JEG-3 cells to test their activity upon T3 treatment. Activity of the TK-(dCpG)Luc encoding a synthetic (dCpG)Luciferase and TK-NanoLuc expressing the NanoLuc reporter was not significantly changed by T3 treatment while the firefly luciferase control was suppressed by ∼2.6-fold. T3 also downregulated the activity of Renilla luciferase by ∼30%. Novel types of luciferase reporters, especially the synthetic (dCpG)Luciferase, can be more accurate to study T3-regulated gene expression than the classical firefly luciferase reporter. Renilla luciferase, a popular transfection control of dual luciferase assays, should be used with caution in conditions with T3 treatment.

2-Aminoimidazole facilitates efficient gene delivery in a low molecular weight poly(amidoamine) dendrimer.

PubMed

Wang, Jing; Hu, Xuefeng; Wang, Dongli; Xie, Cao; Lu, Weiyue; Song, Jie; Wang, Ruifeng; Gao, Chunli; Liu, Min

2018-06-20

Functional groups have shown great potential in gene delivery. However, a number of the reported functional groups can only overcome one certain physiological barrier, resulting in limited transfection efficiencies. Based on the structure-activity relationships of both imidazolyl and guanidyl, we designed a novel multifunctional group, 2-aminoimidazole (AM), for gene delivery. On modifying with the AM group, the transfection efficiency of low molecular weight poly(amidoamine) (G2) was 200 times greater than the parent dendrimer in vitro. In contrast, the transfection efficiency of G2 showed a decreasing trend when it was grafted with imidazole. Assays revealed that the AM group played multiple roles in gene delivery, including condensing DNA into monodisperse nanoparticles of 80-90 nm in diameter, achieving nearly ten times higher cellular-uptake efficacy, and enhancing the abilities of endosome/lysosome escape and nuclear localization. What's more, AM showed low toxicity. These results demonstrate that the AM group could be a promising tool in non-viral gene delivery.

The leukocyte receptor CD84 inhibits Fc epsilon RI-mediated signaling through homophilic interaction in transfected RBL-2H3 cells.

PubMed

Oliver-Vila, Irene; Saborit-Villarroya, Ifigènia; Engel, Pablo; Martin, Margarita

2008-04-01

Signaling through the high-affinity receptor for immunoglobulin E (Fc epsilon RI) results in the coordinated activation of tyrosine kinases, thus leading to calcium mobilization, degranulation, and leukotriene and cytokine synthesis. Here, we show that CD84, a member of the CD150 family of leukocyte receptors, inhibits Fc epsilon RI-mediated mast cell degranulation in CD84-transfected rat basophilic leukaemia-2H3 mast cell line cells (RBL-2H3) through homophilic interaction. There was no reduction in overall protein phosphorylation following IgE triggering in CD84 RBL-2H3 cells. Indeed, phosphorylation of Dok-1 and c-Cbl increased in CD84 RBL-2H3, suggesting that inhibition is mediated by these molecules. MAP kinase phosphorylation (ERK1/2, JNK and p38) and cytokine synthesis were impaired in CD84 RBL-2H3. This inhibitory mechanism was independent of SAP and SHP-2 recruitment. Interestingly, CD84 mutants in tyrosines (Y279F and DeltaY324) reversed this inhibitory profile. These data suggest that CD84 may play a role in modulating Fc epsilon RI-mediated signaling in mast cells. Thus, CD84 could play a protective role against undesired allergic and inflammatory responses.

Vectorial transport of unconjugated and conjugated bile salts by monolayers of LLC-PK1 cells doubly transfected with human NTCP and BSEP or with rat Ntcp and Bsep.

PubMed

Mita, Sachiko; Suzuki, Hiroshi; Akita, Hidetaka; Hayashi, Hisamitsu; Onuki, Reiko; Hofmann, Alan F; Sugiyama, Yuichi

2006-03-01

Na(+)-taurocholate-cotransporting peptide (NTCP)/SLC10A1 and bile salt export pump (BSEP)/ABCB11 synergistically play an important role in the transport of bile salts by the hepatocyte. In this study, we transfected human NTCP and BSEP or rat Ntcp and Bsep into LLC-PK1 cells, a cell line devoid of bile salts transporters. Transport by these cells was characterized with a focus on substrate specificity between rats and humans. The basal to apical flux of taurocholate across NTCP- and BSEP-expressing LLC-PK1 monolayers was 10 times higher than that in the opposite direction, whereas the flux across the monolayer of control and NTCP or BSEP single-expressing cells did not show any vectorial transport. The basal to apical flux of taurocholate was saturated with a K(m) value of 20 microM. Vectorial transcellular transport was also observed for cholate, chenodeoxycholate, ursodeoxycholate, their taurine and glycine conjugates, and taurodeoxycholate and glycodeoxycholate, whereas no transport of lithocholate was detected. To evaluate the respective functions of NTCP and BSEP and to compare them with those of rat Ntcp and Bsep, we calculated the clearance by each transporter in this system. A good correlation in the clearance of the examined bile salts (cholate, chenodeoxycholate, ursodeoxycholate, and their taurine or glycine conjugates) was observed between transport by human and that of rat transporters in terms of their rank order: for NTCP, taurine conjugates > glycine conjugates > unconjugated bile salts, and for BSEP, unconjugated bile salts and glycine conjugates > taurine conjugates. In conclusion, the substrate specificity of human and rat NTCP and BSEP appear to be very similar at least for monovalent bile salts under physiological conditions.

Efficient nucleofection of primary human B cells and B-CLL cells induces apoptosis, which depends on the microenvironment and on the structure of transfected nucleic acids.

PubMed

Seiffert, M; Stilgenbauer, S; Döhner, H; Lichter, P

2007-09-01

Accumulation of neoplastic cells in B-cell chronic lymphocytic leukemia (B-CLL) is thought to be due to intrinsic defects in the apoptotic machinery of the leukemic cells or to an altered, survival-stimulating microenvironment in vivo. Despite their long survival in vivo, B-CLL cells undergo rapid spontaneous apoptosis ex vivo. To maintain survival in vitro, we established a coculture system using the human bone marrow-derived stromal cell line HS-5. The microenvironment in these cocultures lead to B-CLL cell survival for at least several months and therefore provided a tool for valid in vitro analysis, mimicking the in vivo situation. Although primary B lymphocytes are notoriously resistant to most gene transfer techniques, we achieved high transfection efficiency and cell viability in this coculture system by using a nucleofection-based strategy. Surprisingly, the introduction of circular plasmid DNA into B cells and B-CLL cells induced rapid apoptosis, which was independent of the type of transgene used, but dependent on the DNA concentration. However, transfection of these cells with mRNA was highly efficient and resulted in sustained cell viability and potent transgene expression. The described procedure represents a new approach to study gene function in primary B cells and B-CLL cells.

HD-03/ES: A Herbal Medicine Inhibits Hepatitis B Surface Antigen Secretion in Transfected Human Hepatocarcinoma PLC/PRF/5 Cells.

PubMed

Varma, Sandeep R; Sundaram, R; Gopumadhavan, S; Vidyashankar, Satyakumar; Patki, Pralhad S

2013-01-01

HD-03/ES is a herbal formulation used for the treatment of hepatitis B. However, the molecular mechanism involved in the antihepatitis B (HBV) activity of this drug has not been studied using in vitro models. The effect of HD-03/ES on hepatitis B surface antigen (HBsAg) secretion and its gene expression was studied in transfected human hepatocarcinoma PLC/PRF/5 cells. The anti-HBV activity was tested based on the inhibition of HBsAg secretion into the culture media, as detected by HBsAg-specific antibody-mediated enzyme assay (ELISA) at concentrations ranging from 125 to 1000  μ g/mL. The effect of HD-03/ES on HBsAg gene expression was analyzed using semiquantitative multiplex RT-PCR by employing specific primers. The results showed that HD-03/ES suppressed HBsAg production with an IC50 of 380  μ g/mL in PLC/PRF/5 cells for a period of 24 h. HD-03/ES downregulated HBsAg gene expression in PLC/PRF/5 cells. In conclusion, HD-03/ES exhibits strong anti-HBV properties by inhibiting the secretion of hepatitis B surface antigen in PLC/PRF/5 cells, and this action is targeted at the transcription level. Thus, HD-03/ES could be beneficial in the treatment of acute and chronic hepatitis B infections.

A baculovirus (Bombyx mori nuclear polyhedrosis virus) repeat element functions as a powerful constitutive enhancer in transfected insect cells.

PubMed

Lu, M; Farrell, P J; Johnson, R; Iatrou, K

1997-12-05

It has been previously reported that baculovirus homologous regions, the regions of baculovirus genomes that contain the origins of DNA replication, can augment the expression of a small number of baculovirus genes in vitro. We are now reporting that a region of the genome of Bombyx mori nuclear polyhedrosis virus (BmNPV) containing the homologous region 3 (HR3) acts as an enhancer for the promoter of a nonviral gene, the cytoplasmic actin gene of the silkmoth B. mori. Incorporation of the HR3 sequences of BmNPV into an actin promoter-based expression cassette results in an augmentation of transgene expression in transfected cells by two orders of magnitude relative to the control recombinant expression cassette. This increase is due to a corresponding increase in the rate of transcription from the actin promoter and not to replication of the expression cassette and occurs only when the HR3 element is linked to the expression cassette in cis. A comparable degree of enhancement in the activity of the silkworm actin promoter occurs also in heterologous lepidopteran cells. Concomitant supplementation of transfected cells with the BmIE1 trans-activator, which was previously shown to be capable of functioning in vitro as a transcriptional co-activator of the cytoplasmic actin gene promoter, results in more than a 1,000-fold increase in the level of expression of recombinant proteins placed under the control of the actin gene promoter. These findings provide the foundation for the development of a nonlytic insect cell expression system for continuous high-level expression of recombinant proteins. Such a system should provide levels of expression of recombinant proteins comparable to those obtained from baculovirus expression systems and should also have the additional advantage of continuous production in a cellular environment that, in contrast to that generated by a baculovirus infection, supports continuously proper posttranslational modifications of recombinant

Higher Education Exchange, 2014

ERIC Educational Resources Information Center

Brown, David W., Ed.; Witte, Deborah, Ed.

2014-01-01

Research shows that not only does higher education not see the public; when the public, in turn, looks at higher education, it sees mostly malaise, inefficiencies, expense, and unfulfilled promises. Yet, the contributors to this issue of the "Higher Education Exchange" tell of bright spots in higher education where experiments in working…

The Induction of Serine/Threonine Protein Phosphorylations by a PDGFR/TrkA Chimera in Stably Transfected PC12 Cells*

PubMed Central

Biarc, Jordane; Chalkley, Robert J.; Burlingame, A. L.; Bradshaw, Ralph A.

2012-01-01

Stably transfected PC12 cells expressing a chimeric receptor composed of the extracellular domain of the platelet-derived growth factor receptor BB and the transmembrane and intracellular domains of TrkA, the nerve growth factor receptor, were stimulated for 20 min with platelet-derived growth factor and the resulting phosphoproteome was determined from affinity purified tryptic peptides identified by tandem MS (MS/MS) analyses. The changes in the levels of individual phosphorylation sites in stimulated cells versus control were ascertained by the stable isotope labeling of amino acids in cell culture technique. A total of 2035 peptides (806 proteins) were indentified and quantified in both data sets. Of these, 424 phosphopeptides on 259 proteins were found to be up-regulated and 392 sites on 206 proteins were down-regulated (1.8-fold or more). Protein kinases and phosphatases, as well as sites in many proteins involved in G-protein signaling, were prominently represented in the up-regulated group and more than half of the kinase up-regulated phosphosites could be clustered into three sequence motifs; a similar distribution was also found for the down-regulated sites. A comparison of the up-regulated motif profile observed to that calculated from a previous study of the EGFR-induced phosphoproteome in human HeLa cells at the same time point showed a considerable amount of similarity, supporting the view that RTK signal transduction pathways and downstream modifications are likely to be extensively overlapping. PMID:22027198

Upgrading cytochrome P450 activity in HepG2 cells co-transfected with adenoviral vectors for drug hepatotoxicity assessment.

PubMed

Tolosa, Laia; Donato, M Teresa; Pérez-Cataldo, Gabriela; Castell, José Vicente; Gómez-Lechón, M José

2012-12-01

In a number of adverse drug reactions leading to hepatotoxicity, drug metabolism is thought to be involved by the generation of reactive metabolites from non-toxic drugs. The use of hepatoma cell lines, such as HepG2 cell line, for the evaluation of drug-induced hepatotoxicity is hampered by their low cytochrome P450 expression which makes impossible the study of the toxicity produced by bioactivable compounds. Genetically manipulated cells constitute promising tools for hepatotoxicity applications. HepG2 cells were simultaneously transfected with recombinant adenoviruses encoding CYP1A2, CYP2C9 and CYP3A4 to confer them drug-metabolic competence. Upgraded cells (Adv-HepG2) were highly able to metabolize the toxin studied in contrast to the reduced metabolic capacity of HepG2 cells. Aflatoxin B1-induced hepatotoxicity was studied as a proof of concept in metabolically competent and non-competent HepG2 cells by using high content screening technology. Significant differences in mitochondrial membrane potential, intracellular calcium concentration, nuclear morphology and cell viability after treatment with aflatoxin B1 were observed in Adv-HepG2 when compared to HepG2 cells. Rotenone (non bioactivable) and citrate (non hepatotoxic) were analysed as negative controls. This cell model showed to be a suitable hepatic model to test hepatotoxicity of bioactivable drugs and constitutes a valuable alternative for hepatotoxicity testing. Copyright © 2011 Elsevier Ltd. All rights reserved.

Molecular cloning and preliminary function study of iron responsive element binding protein 1 gene from cypermethrin-resistant Culex pipiens pallens

PubMed Central

2011-01-01

Background Insecticide resistance jeopardizes the control of mosquito populations and mosquito-borne disease control, which creates a major public health concern. Two-dimensional electrophoresis identified one protein segment with high sequence homology to part of Aedes aegypti iron-responsive element binding protein (IRE-BP). Method RT-PCR and RACE (rapid amplification of cDNA end) were used to clone a cDNA encoding full length IRE-BP 1. Real-time quantitative RT-PCR was used to evaluate the transcriptional level changes in the Cr-IRE strain Aedes aegypti compared to the susceptible strain of Cx. pipiens pallens. The expression profile of the gene was established in the mosquito life cycle. Methyl tritiated thymidine (3H-TdR) was used to observe the cypermethrin resistance changes in C6/36 cells containing the stably transfected IRE-BP 1 gene of Cx. pipiens pallens. Results The complete sequence of iron responsive element binding protein 1 (IRE-BP 1) has been cloned from the cypermethrin-resistant strain of Culex pipiens pallens (Cr-IRE strain). Quantitative RT-PCR analysis indicated that the IRE-BP 1 transcription level was 6.7 times higher in the Cr-IRE strain than in the susceptible strain of 4th instar larvae. The IRE-BP 1 expression was also found to be consistently higher throughout the life cycle of the Cr-IRE strain. A protein of predicted size 109.4 kDa has been detected by Western blotting in IRE-BP 1-transfected mosquito C6/36 cells. These IRE-BP 1-transfected cells also showed enhanced cypermethrin resistance compared to null-transfected or plasmid vector-transfected cells as determined by 3H-TdR incorporation. Conclusion IRE-BP 1 is expressed at higher levels in the Cr-IRE strain, and may confer some insecticide resistance in Cx. pipiens pallens. PMID:22075242

Comparison of chemotherapeutic drug resistance in cells transfected with canine ABCG2 or feline ABCG2.

PubMed

Lewis, R S; Fidel, J; Dassanayake, S; Court, M H; Burke, N S; Mealey, K L

2017-06-01

ABCG2 (ATP binding cassette subfamily G, member 2) mediates resistance to a variety of cytotoxic agents. Although human ABCG2 is well characterized, the function of canine ABCG2 has not been studied previously. Feline ABCG2 has an amino acid substitution in the adenosine triphosphate-binding domain that decreases its transport capacity relative to human ABCG2. Our goal was to compare canine ABCG2-mediated chemotherapeutic drug resistance to feline ABCG2-mediated chemotherapeutic drug resistance. HEK-293 cells stably transfected with plasmid containing canine ABCG2, feline ABCG2 or no ABCG2 were exposed to carboplatin, doxorubicin, mitoxantrone, toceranib or vincristine, and cell survival was subsequently determined. Canine ABCG2 conferred a greater degree of chemotherapy resistance than feline ABCG2 for mitoxantrone. Neither canine nor feline ABCG2 conferred resistance to doxorubicin, vincristine or toceranib. Canine, but not feline, ABCG2 conferred resistance to carboplatin, a drug that is not reported to be a substrate for ABCG2 in other species. © 2015 John Wiley & Sons Ltd.

[Characteristics of cationic polymers PEI-CyD, PEI-PHPA, PEE-PHPA and PEI25kD in vitro and in vivo].

PubMed

Yao, Qi; Jin, Xue; Hu, Tian-nan; Wang, Qi-wen; Wang, Xun-shi; Hu, Qi-da; Xu, Sang; Zhou, Jun; Tang, Gu-ping

2012-11-01

To study the characteristics of cationic polymers polyethylenimine-β-cyclodextrin (PEI-CyD), polyethylenimine-poly-(3-hydroxypropyl)-aspartamide (PEI-PHPA), N,N-Dimethyldipropylenetriamine-Bis(3-aminopropyl)amine-aspartamide (PEE-PHPA) in vitro and in vivo. PEI-PHPA, PEI-CyD and PEE-PHPA were synthesized and the chemistry structure of PEI-PHPA, PEI-CyD and PEE-PHPA was confirmed by (1)H-NMR. The particle size and zeta potential of these polymers were measured, and capacity of plasmid DNA condensation was tested. The inhibition of COS-7, A549, HEK293 and C6 cells was measured by MTT assay. The transfection efficiency was determined in HEK293 cell lines. The toxicity, tissue distribution and transfection efficiency of cationic polymers were tested in vivo. When the N/P of polymers/DNA at 30, the particle sizes were close 250 nm and the zeta-potential were near 35 mv. They were able to condense DNA at N/P ratio < 5. The MTT assay showed that the IC(50) of PEE-PHPA was 21.5, 20.2, 7.30 and 37.1 μg/ml, and that of PEI25kD was 15.8, 18.3, 11.4 and 36.7 μg/ml in C6, COS-7, A549 and HEK293cell lines, respectively. The cell viability of PEI-CyD and PEI-PHPA in above cell lines was over 60%. They had high transfection efficiency in HEK293 cell lines. The LD(50) of PEI25Kd, PEI-CyD, PEI-PHPA and PEE-PHPA in vivo was 19.50, 100.4, 521.2 and 630.0, respectively by intraperitoneal (ip) injection. The contractions of these polymers were higher in kidney than in other organs and tissues.PEE-PHPA had slight effect on kidney and liver function. PEE and PEI25kD have higher transfection efficiency and higher toxicity; while PC and PHPA-PEI have lower toxicity and higher transfection efficiency to be used as non-viral gene vector.

Transfection of Sclerotinia sclerotiorum with In Vitro Transcripts of a Naturally Occurring Interspecific Recombinant of Sclerotinia sclerotiorum Hypovirus 2 Significantly Reduces Virulence of the Fungus

PubMed Central

Marzano, Shin-Yi Lee; Hobbs, Houston A.; Nelson, Berlin D.; Hartman, Glen L.; Eastburn, Darin M.; McCoppin, Nancy K.

2015-01-01

ABSTRACT A recombinant strain of Sclerotinia sclerotiorum hypovirus 2 (SsHV2) was identified from a North American Sclerotinia sclerotiorum isolate (328) from lettuce (Lactuca sativa L.) by high-throughput sequencing of total RNA. The 5′- and 3′-terminal regions of the genome were determined by rapid amplification of cDNA ends. The assembled nucleotide sequence was up to 92% identical to two recently reported SsHV2 strains but contained a deletion near its 5′ terminus of more than 1.2 kb relative to the other SsHV2 strains and an insertion of 524 nucleotides (nt) that was distantly related to Valsa ceratosperma hypovirus 1. This suggests that the new isolate is a heterologous recombinant of SsHV2 with a yet-uncharacterized hypovirus. We named the new strain Sclerotinia sclerotiorum hypovirus 2 Lactuca (SsHV2L) and deposited the sequence in GenBank with accession number KF898354. Sclerotinia sclerotiorum isolate 328 was coinfected with a strain of Sclerotinia sclerotiorum endornavirus 1 and was debilitated compared to cultures of the same isolate that had been cured of virus infection by cycloheximide treatment and hyphal tipping. To determine whether SsHV2L alone could induce hypovirulence in S. sclerotiorum, a full-length cDNA of the 14,538-nt viral genome was cloned. Transcripts corresponding to the viral RNA were synthesized in vitro and transfected into a virus-free isolate of S. sclerotiorum, DK3. Isolate DK3 transfected with SsHV2L was hypovirulent on soybean and lettuce and exhibited delayed maturation of sclerotia relative to virus-free DK3, completing Koch's postulates for the association of hypovirulence with SsHV2L. IMPORTANCE A cosmopolitan fungus, Sclerotinia sclerotiorum infects more than 400 plant species and causes a plant disease known as white mold that produces significant yield losses in major crops annually. Mycoviruses have been used successfully to reduce losses caused by fungal plant pathogens, but definitive relationships between

[Recombinant adeno-associated virus mediated RNA interference of angiogenin expression inhibits cell growth of human lung adenocarcinoma].