• 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.

• Clinical and Experimental Pediatrics
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• v.51 no.12
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• pp.1336-1341
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• 2008

Purpose : This study aimed to determine the frequencies of $CD4^+CD25^+$ T cells in donor graft and peripheral blood $CD4^+CD25^+$ T cells in recipients after hematopoietic stem cell transplantation (HSCT) and their association with graft-versus-host disease (GVHD). Methods : Seventeen children who underwent HSCT were investigated. $CD4^+CD25^+$ T cells in samples from donor grafts and recipient peripheral blood were assessed by flow cytometry at 1 and 3 months after transplantation. Results : $CD4^+CD25^+$ T cell frequencies in the grafts showed no significant difference between patients with and without acute GVHD (0.90% vs. 1.06%, P=0.62). Absolute $CD4^+CD25^+$ T cell number in grafts were lower in patients with acute GVHD than in those without acute GVHD ($6.18{\times}10^5/kg$ vs. $25.85{\times}10^5/kg$, P=0.09). Patients without acute GVHD showed a significant decrease in peripheral blood $CD4^+CD25^+$ T cell percentage at 3 months compared to those at 1 month after HSCT (2.11% vs. 1.43%, P=0.028). However, in patients with acute GVHD, $CD4^+CD25^+$ T cell percentage at 3 months was not different from the corresponding percentage at 1 month after HSCT (2.47% vs. 2.30%, P=0.5). Conclusion : The effect of frequencies of $CD4^+CD25^+$ T cells in donor grafts on acute GVHD after HSCT could not be identified, and the majority of peripheral blood $CD4^+CD25^+$ T cells in patients who underwent HSCT may be activated T cells related to acute GVHD rather than regulatory T cells. Further studies with additional markers for regulatory T cells are needed to validate our results.

• Journal of Life Science
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• v.33 no.9
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• pp.693-702
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• 2023

The present study examined the rate of cell growth and differentiation potential into adipocytes in A549 lung adenocarcinoma cells exposed to each adipogenic medium containing glucose metabolism hormones, such as thyroxine (T4) thyroid hormone and glucocorticoid (GC) adrenal steroid hormone, as well as pioglitazone (PGZ), a PPARγ agonist. Following each adipogenic treatment for 2 weeks, the rate of cell growth was significantly (p<0.05) inhibited, and the level of telomerase activity was significantly (p<0.05) decreased in the PGZ-based adipogenic medium containing both T4 and GC hormone compared with those containing each T4 or GC hormone. Moreover, the adiposome-like vesicles were highly reacted with Oil-Red O staining solution, and the levels of transcripts expressed in the differentiating adipocytes for adipogenesis, including adinopectin, leptin, and resistin, were significantly (p<0.05) increased in the PGZ-based adipogenic medium containing both T4 and GC hormone compared with those of the adipogenic medium containing each T4 or GC hormone, implying that adipocytic differentiation has fully occurred in the A549 cancer cells. Based on present observations, the PGZ-based adipogenic medium containing both T4 and GC efficiently induces inhibition of cell growth and cellular differentiation into adipocytes in A549 cancer cells rather than in the adipogenic medium containing only T4 or GC hormone. Adipogenic treatment could provide potential probability in cancer chemotherapy.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.31-38
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• 2007

Infection with virulent or attenuated Salmonella typhimuriumhas known to induce reduction in proliferative responses of spleen cells. We investigated a role of lipid A from S. typhimurium, a B cell mitogen, on proliferation of spleen cells by T cell mitogens such as concanavaline A and phytohemagglutinin under in vitro and ex vivo conditions. Lipid A alone induced proliferation of spleen cells in vitroin a dose-dependent manner. However, subsequent treatment of concanavaline A or phytohemagglutin in after lipid A treatment induced proliferation suppression of murine spleen cells in vitro and ex vivo. Removal of macrophages from spleen cells, which were obtained from a lipid A-injected mouse, restored proliferation by concanavaline A and phytohemagglutinin, indicating that macrophages appeared to play a role in lipid A-induced suppression. Secreted molecules from macrophages did not accounted for the suppression because suppressive effect was not achieved when the supernatant from macrophage-containing spleen cell culture was conditoned to macrophage-depleted spleen cell culture. Co-culture of spleen cells from lipid A-treated and - untreated mice showed proliferation suppression as increasing cell numbers of lipid A-treated mouse. These data suggested that the cell-to-cell contact of macrophage with splenic lymphocyte cells is responsible for immune responses against lipid A, which is applicable to the case of human S. typhi infection.

• Journal of Life Science
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• v.18 no.11
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• pp.1600-1605
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• 2008

This study was performed to verify the gene expression of 3T3-L1 using the siRNA of the aromatase gene, which is the estrogen synthesis enzymes. First of all three pairs of siRNA were designed from the CYP19A1 (aromatase) and analyzed the formation of fat cell mechanism by transferring gene to 3T3-L1 and differentiating it. As a result, the expression of leptin gene, which is the main gene causing the obesity, was controlled and the cause of the obesity is related with the insulin specifically. The overexpression of adiponectin and adipsin was observed. This result showed that the formation of the fat was controlled a little without any side effect by obstructing a specific material out of all the signal systems in the fat formation. This study will be an important clue to make it clear that the lack or overexpression of estrogen might be the cause of fat formation mechanism.

• Reproductive and Developmental Biology
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• v.31 no.1
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• pp.1-6
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• 2007

The nonobese diabetic / severe combined immune deficiency (NOD/SCID) has been used for determination of proliferation and differentiation of hematopoietic stem cells as xenotransplantation animal model. In this study, we transplanted porcine hematopoietic cells from bone marrow into NOD/SCID mice via intravenous injection to confirm the activity of differentiation and proliferation for porcine hematopoietic cells in vivo. Interestingly, we observed the result of high efficiency with pig T lymphocytes in hematopoietic organs, liver, spleen lymph node, and bone marrow in NOD/SCID mice. The porcine $CD3^{+}$ T cells were detected with $5.4{\pm}1.9%$ in bone marrow, $15.4{\pm}7.3%$ in spleen, $21.3{\pm}1.4%$ in liver, and $33.5{\pm}32.8%$ in lymph node of NOD/SCID mice at 6 weeks after trans-plantation Furthermore, immunohistochemical analysis showed the high engraftment of porcine T lymphocytes in spleen of NOD/SCID mice. Our data suggest that NOD/SCID mice are excellent animal model to determinate the generation md function of pig T lymphocytes.

• Journal of Life Science
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• v.18 no.2
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• pp.200-205
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• 2008

The purpose of this study is to investigate the effects of the herbal Chokong pill (hereafter HCKP) on the liver cell and enzyme activities of serum in rat. HCKP were mixed with pickled black soybeans and five different kinds of medicinal herbs (Rhynchosia nulubilis, Glycyrrhiza uralensis, Zizyphus vulgaris, Atractylodes macrocephala K., Astragalus membranaceus and Cornus officinalis). Four groups of male Sprague-Dawley rats were fed by different diets for 9 weeks: normal diet (Nor), high-fat diet (HF), high-fat diet supplemented with 1% (T1) and 5% (T5) HCKP powder, respectively. Depending on the presence of HCKP in high fat diet, the activities of the blood serum GOT and GPT were decreased. GOT and GPT activities of T1 and T5 were decreased 6.1%, 17.8% and 25.4%, 32.4% compared with HF. On microstructure observing through the transmission electron microscope (TEM) of liver cell, in normal group, a normal large and clear nucleus, rough endoplasmic reticulum (RER) and mitochondria possessing well-defined double outer-limiting membranes were found. However, in HF, it was hard to observe the microstructures in cytoplasm, because of too many fat granules. It showed severely damaged cell, pyknotic nucleus, swollen disintegrating RER and mitochontria loosing the cristae. In T1, there were more repaired liver cells and less fat granules than HF. In T5, there were much less numbers and smaller size of the fat granules than T1, and the morphology was similar to normal cell.

• Journal of Nutrition and Health
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• v.24 no.4
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• pp.356-365
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• 1991

$L-Triiodothyronine(T_3)$ binding to purified plasma membrane and to isolated nuclei from the same liver in obese(ob/ob) mice and their lean littermates was examined. The maximal binding capacity(Bmax) for $T_3$ receptor of liver nuclei, as compared to lean control, was significantly lower in the obese mouse$(obese 527{\pm}80fmol/mg\;DNA ; lean 883{\pm}62fmol/mg\;DNA)$, without an apparent difference in dissociation constant(Kd). The finding that obese mice have fewer liver nuclear $T_3$ receptors confirms previous reports. The Bmax and Kd of liver plasma membrane $T_3$ receptor were not significantly different between obese and lean mouse, which suggests no defect to be occurring in the function of the plasma membrane $T_3$ receptor and reinforces the view that the peripherally impaired thyroid hormone action in obese mice is a post plasma membrane receptor event. These results further support the hypothesis that the major defect of the thyroid hormone metabolism in genetic obesity occurs at the level of the nuclear receptor.

• Journal of Life Science
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• v.19 no.11
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• pp.1529-1537
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• 2009

To elucidate further the antitumor effects of a natural L-arginine analogue, L-canavanine, the mechanism underlying apoptogenic activity of L-canavanine and its modulation by protein tyrosine kinase $p56^{lck}$ was investigated in human Jurkat T cells. When the cells were treated with 1.25 to 2.5 mM L-canavanine for 36 h, several apoptotic events including mitochondrial membrane potential (${\Delta\Psi}m$) loss, activation of caspase-9, -3, -8, and -7, poly (ADP-ribose) polymerase (PARP) degradation, and DNA fragmentation were induced without alteration in the levels of Fas or FasL. These apoptotic changes were more significant in $p56^{lck}$-deficient Jurkat clone JCaM1.6 than in $p56^{lck}$-positive Jurkat clone E6.1. The L-canavanine-induced apoptosis observed in $p56^{lck}$-deficient JCaM1.6 cells was significantly reduced by introducing $p56^{lck}$ gene into JCaM1.6 cells by stable transfection. Treatment of JCaM1.6/lck cells with L-canavanine caused a transient 1.6-fold increase in the kinase activity of $p56^{lck}$. Both FADD-positive wild-type Jurkat T cell clone A3 and FADD-deficient Jurkat T cell clone I2.1 exhibited a similar susceptibility to the cytotoxicity of L-canavanine, excluding involvement of Fas/FasL system in triggering L-canavanine-induced apoptosis. The L-canavanine-induced apoptotic sub-$G_1$ peak and activation of caspase-3, -8, and -7 were abrogated by pan-caspase inhibitor (z-VAD-fmk), whereas L-canavanine-induced activation of caspase-9 was not affected. These results demonstrated that L-canavanine caused apoptosis of Jurkat T cells via the loss of ${\Delta\Psi}m$, and the activation of caspase-9, -3, -8, and -7, leading to PARP degradation, and that the $p56^{lck}$ kinase attenuated the ${\Delta\Psi}m$ loss and activation of caspases, and thus contributed as a negative regulator to L-canavanine-induced apoptosis.

• Journal of Periodontal and Implant Science
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• v.33 no.1
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• pp.79-89
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• 2003

치주질환은 세균감염에 의해 치조골이 파괴되는 염증성질환으로서 치아상실의 주된 원인이다. Treponema denticola는 성인성 치주염의 병소에서 자주 발견되는 세균으로서 부착능 및 단백분해효소생성능과 같은 독성 인자가 밝혀져 치주조직 파괴에 있어서 중요성이 강조되어 왔다. 골개조는 조골세포의 골형성및 파골세포에 의한 골흡수의 균형에 의하여 유지되며 치주염시 야기되는 치조골파괴는 조골세포 및 파골세포 기능의 불균형에 의하여 야기되는 것으로 설명되고 있다. 골세포에 대한 영향으로서 T. denticola는 파골세포의 형성을 촉진시키는 것으로 보고되었으나 조골세포에 대한 영향은 아직 밝혀져 있지 않다. 따라서 본 연구에서는 T. denticola가 골형성에 미치는 영향을 알아보고자 마우스의 두개골세포로부터 조골세포를 분리한 후 T. denticola분쇄액으로 처리하여 본 세균이 조골세포의 alkaline phosphatase(ALPase) 활성, 석회화결절 형성 및 Prostaglandin $E_2\;(PGE_2)$ 생성에 미치는 영향을 평가하였다. ALPase활성은 p-nitrophenylphosphate분해능, 석회화결절형성은 Von Kossa 염색법, 그리고 PGE2의 농도는 효소면역측정법으로 측정하였다. T. denticola분쇄액 (2.5 ug/ml)은 마우스 두개골세포의 ALPase활성을 억제하였으며 석회화결절의 형성을 감소시켰다. 또한 동일한 농도의 균분쇄액은 마우스 두개골세포의 $PGE_2$ 생산을 증가시켰다. 균분쇄액과 prostaglandin의 합성억제제인 indomethacin으로 세포를 동시에 처리한 경우 T .denticola분쇄액에 의한 $PGE_2$의 생산은 감소되었으나, ALPase의 활성억제에는 변화가 없었다. 균분쇄액을 열처리하여 마우스 두개골세포에 처리하였을 때에도 ALPase의 활성이 억제되는 것에는 변함이 없었다. 이러한 결과는 T. denticola의 구성성분 중 열에 안정한 물질이 prostaglandin과 무관한 경로를 통해 조골세포의 분화를 억제함을 시사하며 이와 같은 T. denticola에 의한 골형성억제가 치주염시 야기되는 치조골 파괴에 관여할 수 있을 것으로 생각된다.