• Journal of Pharmaceutical Investigation
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• v.28 no.2
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• pp.93-98
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• 1998

We have developed liposomes which can be easily prepared with inexpensive lipid, have enhanced stability, and can efficiently deliver DNA into the COS-l cells, Liposome formulations were prepared using cationic materials such as dimethyldioctadecyl ammonium bromide (DDAB), cetyltrimethyl ammonium bromide(CTAB), We investigated the effect of cationic liposome formulations on in vitro DNA transfection, DDAB-containing liposomes showed increased transfection efficiency which was 3.2-fold as much as that by $Lipofectin^{\circledR}$, but CTAB-containing liposomes were inactive in gene transfection. The effect of colipid of DDAB-containing liposome was also investegated. As a colipid, dioleylphosphatidylethanolamine(DOPE) and cholesterol did altered the transfection efficiency of DDAB-containing liposomes. And increased DDAB concentration lowered the transfection efficiency. The optimum amount of liposomal formulation was $10\;{\mu}M$ for $1\;{\mu}g$ of DNA. In the experiment of stability, DOPE-containing liposomes formulation showed a broad size distribution and separation of two major peaks on a 5th day of preparation, but liposomes containing cholesterol was stable for 10 days. DDAB-containing liposomal DNA delivery system was prepared easily and was stable.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.4
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• pp.581-589
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• 1993

A plasmid vector, $RSVLTR/{\beta}G2$, containing lacZ gene under the control of the RSVLTR promoter were transfected into chicken embryo fibroblasts by three different transfection methods. Calcium phosphate, lipsome and DEAE-dextran techniques were applied for transfection of chicken cells. A histochemical assay with X-gal was used as a simple method for screening transfected cells. Plasmid $RSVLTR/{\beta}G2$ was expressed proficiently in the chicken embryo fibroblast. Calcium phosphate-DNA precipitate transfection resulted in the highest efficiency for transient expression of $RSVLTR/{\beta}G2$. Transfected cells formed colonies on the 9th day of incubation indicating stable transformation of the inserted plasmid.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.640-647
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• 2016

By minimizing fluorescence interference phenomena, aequorin-based luminescence technology can provide a relatively sensitive detection platform with integration of $G{\alpha}16$ protein in order to track internal calcium mobilization by G protein-coupled receptors (GPCR). In this type of cell-based functional assay format, it is essential to optimize the transfection process of a receptor and $G{\alpha}16$ protein. For this study, corticotropin releasing factor receptor subtype 2(CRF2) was set as a model system to generate three stable cells with CRF2 and $G{\alpha}16$ in addition to transiently transfected cells under three different conditions. Agonist (sauvagine) and antagonist (K41498) responses in those cells were analyzed to develop the optimum transfection process. As a result, the effective signal ratio in the dose response experiments of sauvagine and K41498 were at least 10-fold higher (z'=0.77) in CRF2-$G{\alpha}16$ stable cells. For the transient transfection cells, stable expression of $G{\alpha}16$ prior to the CRF2 represented a two-fold higher signal (z'=0.84) than the other cases of transient transfection. In conclusion, for the utilization of transient transfection processes to develop a cell-based GPCR functional assay system, it is suggested to introduce various target receptors after stable expression of $G{\alpha}16$ protein.

• Bulletin of the Korean Chemical Society
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• v.26 no.8
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• pp.1209-1213
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• 2005

Nuclear membrane is one of the main barriers in intracellular delivery of genetic materials. The previous report showed that glucocorticoid receptor dilated the nuclear pore to 60 nm in the presence of a ligand. It was also suggested that the transport of genetic material to nucleus might be facilitated by glucocorticoid. In this study, the effect of glucocorticoid preincubation in the polymeric gene delivery was investigated. The cells were preincubated with dexamethasone, a potent glucocorticoid, and transfection assays were performed with polyethylenimine (PEI) and polyamidoamine (PAMAM) dendrimer. As a result, the transfection efficiency of PEI or PAMAM to the cells in the presence of dexamethasone was enhanced, compared to the cells without dexamethasone. This effect was not observed in the cells preincubated with cholesterol. The polymer/DNA complex was stable in the presence of dexamethasone. In addition, the cytotoxicities of the polymeric carriers to the cells were observed in the presence of dexamethasone. In conclusion, dexamethasone enhances the transfection efficiency of polymeric carriers and may be useful in the development of polymeric gene carriers.

• Korean Journal of Microbiology
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• v.27 no.1
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• pp.10-15
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• 1989

The plasmid pKOneo, containing SV40 transcriptional promoter, has been used in the mouse tumorigenicity assay for oncogene studies. This assay employs a cotransfection of NIG3T3 fibroblast cells with the desired DNA and the plasmid pKOneo. This oncogene assay, however, has been speculated due to the SV40 transcriptional promoter in the plasmid pKOneo. This research was designed to investigate if the plasmid pKOneo alone is capable of transforming NiH3T3 fibroblast cells. The NIH3T3 subclones were established after the NIH3T3 cells were transfected with the plasmid pKOneo alone. The estabilished NIH3T3 subclones, containing the exogeneous plasmid pKOneo in their chromosomes, were examined for their expression of transformation-associated parameters. The results indicate that this plasmid pKOneo alone has positive effects on transformation of NIH3T3 cells after integration into cellular chromosomes.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1536-1540
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• 2012

Chicken primordial germ cells (cPGCs) are founder germ cells in embryonic stage of development that eventually give rise to sperms or oocytes. Currently cPGCs are only known cells enabling germline transmission in chicken and their cultivation protocols were recently established. Although genome modifications of chickens are now theoretically possible using cPGCs, there are still several hurdles to overcome to practically use cPGCs as mediators for chicken transgenesis. First, efficiency of gene delivery into cPGCs remains low with current methods. Second, there aregene silencing mechanisms against the expression of foreign genes in cPGCs. In this study, we successfully increased the efficiency of gene delivery in cPGCs by taking advantage of the TTAA-specific $piggybac$ transposon system. Moreover, a pipette-type electroporator significantly enhanced transfection efficiency up to 5-fold compared withcuvette-type methods. Taken together, the technological advances in our study will provide practical benefits for the application to fulfill genetic modifications of chicken genome.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3665-3670
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• 2013

The R3V6 peptide includes a hydrophilic arginine stretch and a hydrophobic valine stretch. In previous studies, the R3V6 peptide was evaluated as a gene carrier and was found to have low cytotoxicity. However, the transfection efficiency of R3V6 was lower than that of poly-L-lysine (PLL) in N2A neuroblastoma cells. In this study, the transfection efficiency of R3V6 was improved in combination with high mobility group box 1A domain (HMGA). HMGA is originated from the nuclear protein and has many positively-charged amino acids. Therefore, HMGA binds to DNA via charge interaction. In addition, HMGA has a nuclear localization signal peptide and may increase the delivery efficiency of DNA into the nucleus. The ternary complex with HMGA, R3V6, and DNA was prepared and evaluated as a gene carrier. First, the HMGA/DNA complex was prepared with a negative surface charge. Then, R3V6 was added to the complex to coat the negative charges of the HMGA/DNA complex, forming the ternary complex of HMGA, R3V6, and DNA. A physical characterization study showed that the ternary complex was more stable than the PLL/DNA complex. The HMGA/R3V6/DNA complex had a higher transfection efficiency than the PLL/DNA, HMGA/DNA, or R3V6/DNA complexes in N2A cells. Furthermore, the HMGA/R3V6/DNA complex was not toxic to cells. Therefore, the HMGA/R3V6/DNA complex may be a useful gene delivery carrier.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.651-655
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• 2011

We synthesized a novel cationic dendrimer consisting of a poly(amidoamine) dendrimer (PAMAM, generation 4) backbone with both L-arginine (Arg) at the termini and 6-aminohexanoic acid (Ahx) between the original core polymer and the peripheral Arg units. The sequential chemical modification of PAMAM G4 with Ahx and Arg resulted in higher transfection efficiency with much less cytotoxicity. PAMAM G4-Ahx-Arg formed stable polyplexes at weight ratios of 8:1 or higher (polymer: plasmid DNA), and the mean polyplex diameter was $180{\pm}20nm$. PAMAM G4-Ahx-Arg showed much higher transfection ability than PAMAM G4 or PAMAM G4-Ahx. Furthermore, PAMAM G4-Ahx-Arg was much less cytotoxic than PEI25KD and PAMAM G4-Arg. In addition to Arg grafting of the PAMAM dendrimer, which endows a higher transfection capability, the addition of Ahx spacer increased dendrimer hydrophobicity, introduced flexibility into the conjugated amino acids, and reduced cytotoxicity. Overall, it appears that the concomitant modification of PAMAM with Ahx and Arg could lead to new PAMAM conjugates with better performances.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.500-504
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• 2006

Haptoglobin (Hp) is an acute phase protein, and its plasma level increases consistently in response to inflammation. To investigate the biological role of Hp in lung epithelial cells, the gene expressions of cyclooxygenase-2 (COX-2) and inflammatory cytokines were analyzed using human Hp gene-transfected A549 cells. Western blot analysis showed that COX-2 expression was markedly increased in Hp DNA-transfected cells (stable transfection and transient transfection) compared with that in vehicle DNA-transfected cells. When the Hp-expressing cells were treated with $1{\mu}g/ml$ of LPS or 100 U/ml of $IL-1{\beta}$ for 24 hr, the COX-2 expression was synergistically up-regulated. ACP-based PCR data demonstrated the Hp decreased SPARC expression, but increased IL-4 and S100AI expressions. These findings suggest that the Hp acts as a pro-inflammatory mediator in lung inflammation.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.6
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• pp.886-892
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• 2017

Objective: Transgenic technology is widely used for industrial applications and basic research. Systems that allow for genetic modification play a crucial role in biotechnology for a number of purposes, including the functional analysis of specific genes and the production of exogenous proteins. In this study, we examined and verified the cumate-inducible transgene expression system in chicken DF1 and quail QM7 cells, as well as loxP element-mediated transgene recombination using Cre recombinase in DF1 cells. Methods: After stable transfer of the transgene with piggyBac transposon and transposase, transgene expression was induced by an appropriate concentration of cumate. Additionally, we showed that the transgene can be replaced with additional transgenes by co-transfection with the Cre recombinase expression vector. Results: In the cumate-GFP DF1 and QM7 cells, green fluorescent protein (GFP) expression was repressed in the off state in the absence of cumate, and the GFP transgene expression was successfully induced in the presence of cumate. In the cumate-MyoD DF1 cells, MyoD transgene expression was induced by cumate, and the genes controlled by MyoD were upregulated according to the number of days in culture. Additionally, for the translocation experiments, a stable enhanced green fluorescent protein (eGFP)-expressing DF1 cell line transfected with the loxP66-eGFP-loxP71 vector was established, and DsRed-positive and eGFP-negative cells were observed after 14 days of co-transfection with the DsRed transgene and Cre recombinase indicating that the eGFP transgene was excised, and the DsRed transgene was replaced by Cre recombination. Conclusion: Transgene induction or replacement cassette systems in avian cells can be applied in functional genomics studies of specific genes and adapted further for efficient generation of transgenic poultry to modulate target gene expression.