• Archives of Pharmacal Research
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• v.21 no.5
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• pp.521-526
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• 1998

The physicochmical properties of recombinant hepatitis B surface antigen (r-HBsAg), which was expressed in C127 mammalian cell were studied. Using roller bottle culture in DMEM supplemented with fetal bovine serum, 10-15 mg/L of r-HBsAg was produced with about 31% of purification yield. The purity of r-HBsAg by HPLC was 99.8% and electron microscopic examination showed homogeneous spherical particle with 22 nm in diameter, a morphological characteristic of HBsAg. The density of r-HBsAg by CsCI density gradient method was 1.19g/ml and the isoelectric point by Mono $P^{TM}$ HR 5/20 column was 4.6. The analysis of subunit protein pattern using SDS-PAGE followed by scanning densitometry gave 81.3% of S protein and 18.7% of pre-S protein. fluorophore-assisted-carbohydrate-electrophoresis analysis showed the relative amount of carbohydrate to protein was 1.7% and it smajr component was N-acetyl glucosamine, which was about 39% of total carbohydrate. The relative amount of lipid to protein determined by vanillin phosphoric acid method was 32.5% and its major component was phospholipid, which was about 70% of total lipid. The physicochemical properties of C127 mammalian cell-derved r-HBsAg are similar to those of p-HBsAg, suggesting that the r-HBsAg can be used in developing a new preventive vaccine against hepatitis B.

• Molecular & Cellular Toxicology
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• v.4 no.4
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• pp.285-292
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• 2008

Crocin is one of the major components of gardenia fruit and saffron which are widely used as natural food colorants and as traditional Chinese medicines. However, the genotoxicity data on crocin are not sufficient for safety evaluation. The purpose of this study was the examination of the genotoxicity on crocin from gardenia yellow in bacterial and mammalian cells, using various genotoxic battery testing assays and the influence of crocin on methyl methanesulfonate (MMS) and ${H_2}{O_2}$-induced DNA damage in vitro, using single cell gel electrophoresis (comet) assay. From results, no considerable mutagenicity and clastogenicity were seen in bacteria and mammalian cells treated with crocin, by Ames test, chromosomal aberration assay, ${tk}^{+/-}$ gene forward mutation assay and comet assay. And, post-treatment with crocin significantly suppressed ${H_2}{O_2}$-induced DNA damage in a dose-dependent manner. In conclusion, the findings of the present study and other previous observations indicate that crocin has no genotoxic potential. And it showed that crocin clearly repressed the genotoxic potency of ${H_2}{O_2}$. These results suggest that anti-oxidative effects of crocin may be involved in the protective effects of DNA damage.

• Journal of Microbiology and Biotechnology
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• v.15 no.3
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• pp.544-550
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• 2005

To develop a highly efficient mammalian expression vector, a series of vectors were constructed based on the murine cytomegalovirus (MCMV) immediate-early (IE) promoter and human ${\beta}$-globin second intron. The resulting MCMV promoter was several-fold stronger than the HCMV promoter in various mammalian cell lines, such as the NIH3T3, Neuro-2a, 293T, and HT1080 cell lines, and was only slightly weaker than the HCMV promoter in HeLa and CHO cells. The inclusion of the human ${\beta}$-globin second intron behind the MCMV promoter or HCMV promoter markedly enhanced the promoter activity in various mammalian cell lines, and the resultant MCMV/Glo-I expression system was stronger than the HCMV promoter from 4.7- to 11.2-fold in every cell line tested. Also, the MCMV/Glo-I promoter induced a higher level of the VSV-G protein in a transiently transfected 293T cell line, which is useful for the production of recombinant retrovirus and lentivirus vectors.

• Mass Spectrometry Letters
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• v.4 no.3
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• pp.41-46
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• 2013

The goal of this study is to find an experimental condition which enables us to perform enzymatic studies on the cellular behavior of PTEN (phosphatase and tensine homolog) through identification of molecular species of phosphatidylinositol 3,4,5-trisphosphates and their quantitative analysis in a mammalian cell line using mass spectrometry. We initially exployed a two-step extraction process using HCl for extraction of phosphatidylinositol 3,4,5-trisphosphates from two mammalian cell lines and further analyzed the extracted phosphatidylinositol 3,4,5-trisphosphates using tandem mass spectrometry for the identification of them. We finally quantified the concentration of phosphatidylinositol 3,4,5-trisphosphates using internal standard calibration. From these observation, we found that HEK 293-T cells is a good model to examine the enzymatic behavior of PTEN in a cell, and the minimum amount of phosphatidylinositol 3,4,5-trisphosphates is more than 50 pmol for quantification in a mass spectrometer. These results suggest that the well-optimized experimental conditions are required for the investigation of the cellular PTEN in terms of the catalytic mechanism and further for the detailed identification of cellular substrates.

• BMB Reports
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• v.56 no.9
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• pp.502-507
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• 2023

Photobiomodulation therapy has been proposed as a promising therapeutic approach for retinal degenerative diseases. However, its effect on the regenerative capacity in mammalian retina and its intracellular signalling mechanisms remain unknown. Here, we show that photobiomodulation with 670 nm light stimulates Müller glia cell cycle re-entry and dedifferentiation into a progenitor-like state in both the uninjured and injured retina. We also find that 670 nm light treatment inhibits the Hippo pathway, which is activated in Müller glia following NaIO₃-induced retinal injury. YAP, a major downstream effector of the Hippo signalling pathway was translocated into the nucleus of Müller glia along with YAP dephosphorylation in retina treated with 670 nm light. Deficiency of YAP attenuated Müller glia cell cycle re-entry and dedifferentiation. Our data reveal that the Hippo-YAP signalling pathway is associated with the photostimulatory effect on regenerative response in mammalian retina, and suggest a potential therapeutic strategy for retinal degenerative diseases.

• Journal of Marine Life Science
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• v.8 no.2
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• pp.186-189
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• 2023

Uncoupling protein 1 (UCP1) is a unique mitochondrial membranous protein expressed in brown adipose tissue (BAT) in mammals. While its expression in response to cold temperatures and adipogenic inducers is well-characterized in mammals and human infants, the molecular characterization and expression of UCP1 in fish remain unexplored. To address this gap, we analyzed UCP1 expression in response to adipogenic inducers in a fish cell line, rainbow trout gonadal cells (RTG-2), and compared it with UCP1 expression in three mammalian preadipocytes, 3T3-L1, T37i, and WT1 exposed to the Peroxisome proliferator-activated receptor gamma (PPARγ) agonists, rosiglitazone (Rosi). In mammalian preadipocytes, UCP1 protein was highly expressed by Rosi, with an induction of adipogenesis observed in a time-dependent manner. This suggests that UCP1 plays a significant role in adipogenesis in mammals. However, RTG-2 cells showed no response to adipogenic inducers and exhibited only marginal expressions of UCP1. These results imply that RTG-2 cells may lack crucial responsive mechanisms to adipogenic signals or that the adipogenic response is regulated by other mechanisms. Further studies are needed to confirm these phenomena in fish preadipocytes when an appropriate cell line is established in future research.

• Journal of Life Science
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• v.18 no.7
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• pp.940-946
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• 2008

Neurotransmitter transporters, which remove neurotransmittesr from the synaptic cleft, are regulated by second messenger such as protein kinases and binding proteins. Neuronal ${\gamma}-aminobutyric$ acid transporters (GATs) are responsible for removing the inhibitory neurotransmitter ${\gamma}-aminobutyric$ acid (GABA) from the synaptic cleft. ${\gamma}-aminobutyric$ acid transporters 2 (GAT2/BGT1) is involved in regulating neurotransmitter recycling, but the mechanism how they are stabilized and regulated by the specific binding protein has not yet been elucidated. Here, we used the yeast two-hybrid system to identify the specific binding protein(s) that interacts with the C-terminal region of GAT2 and found a specific interaction with the mammalian LIN-7b (MALS-2). MALS-2 protein bound to the tail region of GAT2 but not to other GAT members in the yeast two-hybrid assay. The "T-X-L" motif at the C-terminal end of GAT2 is essential for interaction with MALS-2. In addition, this protein showed specific interactions in the glutathione S-transferase (GST) pull-down assay. An antibody to GAT2 specifically co-immunoprecipitated MALS associated with GAT2 from mouse brain extracts. These results suggest that MALS may stabilize GAT2 in brain.

• Molecular & Cellular Toxicology
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• v.2 no.3
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• pp.176-184
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• 2006

The controversy on genotoxicity of molinate, an herbicide, has been reported in bacterial system, and in vitro and in vivo mammalian systems. To clarify the genotoxicity of molinate, we performed bacterial gene mutation test, in vitro chromosome aberration and mouse lymphoma $tk^{+/-}$ gene assay, and in vivo micronucleus assay using bone marrow cells and peripheral reticulocytes of mice. In bacterial gene mutation assay, no mutagenicity of molinate ($12-185{\mu}g/plate$) was observed in Salmonella typhimurium TA 98, 100, 1535 and 1537 both in the absence and in the presence of S-9 metabolic activation system. The clastogenicity of molinate was observed in the presence ($102.1-408.2\;{\mu}g/mL$) of metabolic activation system in mammalian cell system using Chinese hamster lung fibroblast. However, no clastogenicity was observed in the absence ($13.6-54.3\;{\mu}g/mL$) of metabolic activation system. It is suggested that the genotoxicity of molinate was derived some metabolites by metabolic activation. Molinate was also subjected to mouse lymphoma L5178Y $tk^{+/-}$ cells using microtiter cloning technique. In the absence of S-9 mixture, mutation frequencies (MFs) were revealed $1.4-1.9{\times}10^{-4}$ with no statistical significance. However, MFs in the presence of metabolic activation system revealed $3.2-3.4{\times}10^{-4}$ with statistical significance (p<0.05). In vivo micronucleus (MN) assay using mouse bone marrow cells, molinate revealed genotoxic potential in the dose ranges of 100-398 mg/kg of molinate when administered orally. Molinate also subjected to acridine orange MN assay with mouse peripheral reticulocytes. The frequency of micronucleated reticulocytes (MNRETs) induced 48 hr after i.p. injection at a single dose of 91, 182 and 363 mg/kg of molinate was dose-dependently increased as $10.2{\pm}4.7,\;14.6{\pm}3.9\;and\;28.6{\pm}6.3\;(mean{\pm}SD\;of\;MNRETs/2,000\;reticulocytes)$ with statistical significance (p<0.05), respectively. Consequently, genotoxic potential of molinate was observed in in vitro mammalian mutagenicity systems only in the presence of metabolic activation system and in vivo MN assay using both bone marrow cells and peripheral reticulocytes in the dose ranges used in this experiment. These results suggest that metabolic activation plays a critical role to express the genotoxicity of molinate in in vitro and in vivo mammalian system.

• Clinical and Experimental Reproductive Medicine
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• v.12 no.2
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• pp.81-88
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• 1985

• Proceedings of the Zoological Society Korea Conference
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• 2006.08a
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• pp.18-18
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• 2006