• Parasites, Hosts and Diseases
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• v.61 no.2
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• pp.138-146
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• 2023

Toxoplasma gondii is an intracellular protozoan parasite which can infect most warm-blooded animals and humans. Among the different mouse models, C57BL/6 mice are more susceptible to T. gondii infection compared to BALB/c mice, and this increased susceptibility has been attributed to various factors, including T-cell responses. Dendritic cells (DCs) are the most prominent type of antigen-presenting cells and regulate the host immune response, including the response of T-cells. However, differences in the DC responses of these mouse strains to T. gondii infection have yet to be characterized. In this study, we cultured bone marrow-derived DCs (BMDCs) from BALB/c and C57BL/6 mice. These cells were infected with T. gondii. The activation of the BMDCs was assessed based on the expression of cell surface markers and cytokines. In the BMDCs of both mouse strains, we detected significant increases in the expression of cell surface T-cell co-stimulatory molecules (major histocompatibility complex (MHC) II, CD40, CD80, and CD86) and cytokines (tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-12p40, IL-1β, and IL-10) from 3 h post-T. gondii infection. The expression of MHC II, CD40, CD80, CD86, IFN-γ, IL-12p40, and IL-1β was significantly higher in the T. gondii-infected BMDCs obtained from the C57BL/6 mice than in those from the BALB/c mice. These findings indicate that differences in the activation status of the BMDCs in the BALB/c and C57BL/6 mice may account for their differential susceptibility to T. gondii.

• Journal of Life Science
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• v.21 no.4
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• pp.481-485
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• 2011

T0901317 is a potent synthetic ligand for liver X receptor (LXR, NR1H2/3), a member of the nuclear receptor superfamily that functions as a transcription factor. However, T0901317 has been also reported to modulate the activity at least four other nuclear receptors (NRs), acting as agonists for farnesoid X receptor (FXR, NR1H4) and pregnane X receptor (PXR, NR1I2) and as antagonists for androgen receptor (AR, NR3C4) and retinoid-related orphan receptor-${\alpha}$ (ROR-${\alpha}$, NR1F1). We report here that T0901317 can also function as an inhibitor for constitutive androstane receptor (CAR, NR1I3). Since CAR is a major player of xenobiotic and cholesterol metabolism in the liver, along with PXR, FXR and LXR, which are reported to be regulated by T0901317, this further complicates the interpretation of potential results with T0901317 in liver cells.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.20-20
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• 2011

It has been known that, under certain conditions, application of low-temperature atmospheric-pressure plasmas can enhance proliferation of cells. In this study, conditions for optimal cell proliferation were examined for various cells relevant for orthopaedic applications. Plasmas used in our experiments were generated by dielectric barrier discharge (DBD) with a helium flow (of approximately 3 litter/min) into ambient air at atmospheric pressure by a 10 kV~20 kHz power supply. Such plasmas were directly applied to a medium, in which cells of interest were cultured. The cells examined in this study were human synoviocytes, rat mesenchymal stem cells derived from bone marrow or adipose tissue, a mouse osteoblastic cell line (MC3T3-E1), a mouse embryonic mesenchymal cell line (C3H-10T1/2), human osteosarcoma cells (HOS), a mouse myoblast cell line (C2C12), and rat Schwann cells. Since cell proliferation can be enhanced even if the cells are not directly exposed to plasmas but cultured in a medium that is pre-treated by plasma application, it is surmised that long-life free radicals generated in the medium by plasma application stimulate cell proliferation if their densities are appropriate. The level of free radical generation in the medium was examined by dROMs tests and correlation between cell proliferation and oxidative stress was observed. Other applications of plasma medicine in orthopaedics, such as plasma modification of artificial bones and wound healing effects by direct plasma application for mouse models, will be also discussed. The work has been done in collaboration with Prof. H. Yoshikawa and his group members at the School of Medicine, Osaka University.

• Environmental Mutagens and Carcinogens
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• v.18 no.2
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• pp.98-103
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• 1998

Epigallocatechin gallate (EGCG) was reported to exert weak cytotoxicity against normal healthy cells such as C3H10T1/2 cells, but profound inhibitory effects on the initiation or promotion stage of chemical carcinogenesis in mammary gland, blood and mouse skin. This study was carried out to develop antitumor agents with weak side effects and strong antitumor activity. Human skin melanoma cells (HBT 69) and human oral epitheloid carcinoma cells (OCL 17) were cultured in RPMI-1640 media containing 10% fetal bovine serum, antibiotic, and fungizone. After incubation for 24 hrs, the cells were treated with various amounts of (EGCG) for 48 hrs. The growth inhibitory effects of EGCG in human oral epitheloid carcinoma cells were evaluated by the 3- (4,5-djmethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), neutral red (NR), and sulforhodamine B protein (SRB) assays of colorimetric methods. The light microscopic study was also carried out to observe morphological changes of the treated cells. These results obtained were as follows; 1. Significantly inhibitory effects of EGCG against cultured human oral epithelioid carcinoma cells. 2. Significantly inhibitory effects against cultured human skin melanoma cells treated with 50 $\mu$M EGCG, but decreased inhibitory effects in 100 $\mu$M EGCG. 3. Degenerative changes against cultured human oral epitheloid carcinoma cells. 4. Degenerative changes against human skin melanoma cells treated with 50 UM EGCG, but recovered degenerative changes in 100 $\mu$M EGCG.

• IMMUNE NETWORK
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• v.10 no.2
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• pp.46-54
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• 2010

Background: Graft-versus-host disease (GVHD) is initiated when alloreactive donor T cells are primed by host APCs to undergo clonal expansion and maturation. Since there is a controversy regarding the role of nonhematopoietic cells in GVHD, we wanted to investigate the influence of MHC disparity on nonhematopoietic cells on the pathogenesis of GVHD in the MHC-haplomismatched C57BL/6 ($H-2^b$) or DBA/2 $(H-2^b){\rightarrow}$unirradiated ($C57BL/6{\times}DBA/2$) $F_1(BDF_1;\;H-2^{b/d})$ murine model of acute GVHD (aGVHD) or chronic GVHD (cGVHD). Methods: We generated ($BDF_1{\rightarrow}C57BL/6$), ($BDF_1{\rightarrow}DBA/2$), and ($BDF1{\rightarrow}BDF_1$) chimeras and examined GVHD-related parameters and donor cell engraftment in those chimeras. Results: Using this experimental system, we found that 1) severe aGVHD across MHC Ag barrier depends on the expression of nonhematopoietically rather than hematopoietically derived alloAgs for maximal GVHD manifestations; 2) host APCs were sufficient to break B cell tolerance to self molecules in cGVHD, whereas host APCs were insufficient to induce autoimmunity in aGVHD; 3) donor cell engraftment was greatly enhanced in the host with MHC-matched nonhematopoietic cells. Conclusion: Taken together, our results provide an insight into how MHC disparity on GVHD target organs contribute to the pathogenesis of GVHD.

• International Journal of Stem Cells
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• v.15 no.3
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• pp.291-300
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• 2022

Background and Objectives: Many preclinical studies have been conducted using animal disease models to determine the effectiveness of human mesenchymal stem cells (hMSCs) for treating immune and inflammatory diseases based on the belief that hMSCs are not immunogenic across species. However, several researchers have suggested xenogeneic immune responses to hMSCs in animals, still without detailed features. This study aimed to investigate a xenogeneic humoral immune response to hMSCs in mice in detail. Methods and Results: Balb/c mice were intraperitoneally injected with adipose tissue-derived or Wharton's jelly-derived hMSCs. Sera from these mice were titrated for each isotype. To confirm specificity of the antibodies, hMSCs were stained with the sera and subjected to a flow cytometic analysis. Spleens were immunostained for proliferating cell nuclear antigen to verify the germinal center formation. Additionally, splenocytes were subjected to a flow cytometric analysis for surface markers including GL-7, B220, CD4, CD8, CD44, and CD62L. Similar experiments were repeated in C57BL/6 mice. The results showed increased IgG₁ and IgG_2a titers in the sera from Balb/c mice injected with hMSCs, and the titers were much higher in the secondary sera than in the primary sera. These antibodies were specifically stained the hMSCs. Germinal centers were observed in the spleen, and flow cytometric analysis of the splenocytes showed higher frequencies of centroblasts (B220⁺ GL7⁺) and memory T cells (CD62L⁺ CD44⁺) both in CD4⁺ and CD8⁺ subsets. Similar results were obtained for C57BL/6 mice. Conclusions: hMSCs induced a humoral immune response in mice, with characters of T cell-dependent immunity.

• Journal of Microbiology and Biotechnology
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• v.23 no.2
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• pp.189-194
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• 2013

In a study of hydrogen-producing bacteria, strain T4384 was isolated from rice field samples in the Republic of Korea. The isolate was identified as Enterobacter sp. T4384 by phylogenetic analysis of 16S rRNA and rpoB gene sequences. Enterobacter sp. T4384 grew at a temperature range of $10-45^{\circ}C$ and at an initial pH range of 4.5-9.5. Strain T4384 produced hydrogen at 0-6% NaCl by using glucose, fructose, and mannose. In serum bottle cultures using a complete medium, Enterobacter sp. T4384 produced 1,098 ml/l $H_2$, 4.0 g/l ethanol, and 1.0 g/l acetic acid. In a pH-regulated jar fermenter culture with the biogas removed, 2,202 ml/l $H_2$, 6.2 g/l ethanol, and 1.0 g/l acetic acid were produced, and the lag-phase time was 4.8 h. Strain T4384 metabolized the hydrolysate of organic waste for the production of hydrogen and volatile fatty acid. The strain T4384 produced 947 ml/l $H_2$, 3.2 g/l ethanol, and 0.2 g/l acetic acid from 6% (w/v) food waste hydrolysate; 738 ml/l $H_2$, 4.2 g/l ethanol, and 0.8 g/l acetic acid from Miscanthus sinensis hydrolysate; and 805 ml/l $H_2$, 5.0 g/l ethanol, and 0.7 g/l acetic acid from Sorghum bicolor hydrolysate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.3
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• pp.367-373
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• 2014

In this study, we investigated the anticancer activity of methyl gallate (MG), which is the major biologically active component of Galla Rhois, in RC-58T/h/SA#4 human prostate cancer cells. MG inhibited cell proliferation in a dose-dependent manner. Cell death induced by MG increased the population of cells in sub-G1 phase, formation of apoptotic bodies, nuclear condensation, and DNA fragmentation. Apoptosis induced by MG was associated with activation of initiator caspases-8 and -9 as well as effector caspase-3. Endocrine disruptors such as dioxin and bisphenol A increased growth of RC-58T/h/SA#4 cells in charcoal-treated FBS (cFBS) medium. Cell proliferation was highest upon treatment with 1 nM and $0.1{\mu}M$ dioxin and bisphenol A, respectively. MG also dose-dependently inhibited cell proliferation in RC-58T/h/SA#4 cells treated with endocrine disruptors. These results indicate that MG exerts anticancer effects on RC-58T/h/SA#4 primary human prostate cancer cells.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.9
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• pp.1242-1248
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• 2005

This study was designed to investigate the in vitro developmental ability and apoptosis of bovine embryos nucleartransferred (NT) with frozen-thawed or cooled donor cells. Cultured adult bovine ear cells were used as donor cells after sub-culturing to confluence (CC), cooling to 4$^{\circ}C$ for 48 h, or freezing-thawing (FT). Apoptotic cells in blastocysts were evaluated for apoptosis by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) method. Fusion, cleavage and blastocyst rates were 69.0 (167/242), 68.8 (115/167), and 29.9 (50/167) with CC cells, 70.4 (88/125), 69.3 (61/88), and 29.6 (26/88) with cooled cells and 66.1 (117/177), 70.1 (82/117), and 13.7 (16/117) with FT cells, respectively. Blastocyst rates of NT embryos derived from FT cells were significantly lower than those from CC or cooled cells (p<0.05). In addition, NT blastocysts produced by using FT cells showed significantly higher apoptosis rates (6.4${\pm}$4.0%) than those produced by CC (2.8${\pm}$1.7%) or cooled (2.3${\pm}$1.3%) cells. However, cooling of donor cells had no significant adverse effect on blastocyst rate as well as apoptosis rate. Therefore, our results suggest that cooled cells may be used as an alternative to freshly cultured confluent culture cells, as donor cells, for the production of Somatic nuclear cloned cattle.

• Korean Journal of Ecology and Environment
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• v.46 no.4
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• pp.588-595
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• 2013

This study investigated the influence of temperature and $CO_2$ increase on phytoplankton growth and community structure during cold water season (spring) in Lake Paldang, Korea. Four experimental treatments of temperature and $CO_2$ manipulation were prepared in the laboratory batch culture: (1) Control; ambient low temperature ($6{\pm}2^{\circ}C$) and low $CO_2$ (air level, $400mgL^{-1}$), (2) T1; low temperature and high $CO_2$ ($800mgL^{-1}$), (3) T2; high temperature ($20{\pm}2^{\circ}C$) and low $CO_2$, (4) T3; high temperature and high $CO_2$. Algal growth experiment was carried out for 10 days under the light intensity of $70{\mu}mol\;m^{-2}s^{-1}$ (L :D=24 : 0). The level of pH decreased in both T1 and T3, due to dissolution of added $CO_2$. The dominant phytoplankton species of ambient water, Cyclotella meneghiniana succeeded to Fragilaria capucina var. gracilis in high-temperature treatment groups (T2 and T3). Cyanobacteria were very rare at the beginning of the experiment, while Oscillatoria limnetica appeared in only high-temperature groups (T2 and T3) at $6{\sim}7^{th}$ day. $CO_2$ addition in ambient temperature (T1) induced the highest phytoplankton growth, and thereby producing the highest average cell density of $3.27{\pm}0.33\;10^4\;cells\;mL^{-1}$, followed by T2 ($2.65{\pm}0.26\;10^4\;cells\;mL^{-1}$), T3 ($2.09{\pm}0.16\;10^4\;cells\;mL^{-1}$), and Control ($1.86{\pm}0.13\;10^4\;cells\;mL^{-1}$) (F=7.167, p=0.000). In summary, temperature increase changed the phytoplankton community structure and $CO_2$ increase promoted the phytoplankton growth during the cold spring season in Lake Paldang, suggesting a potential effect of climate change on freshwater phytoplankton.