• Applied Biological Chemistry
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• v.44 no.1
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• pp.1-6
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• 2001

To elucidate the apoptosis mechanism of Trichoplusia ni cell, fundamental studies for apoptosis induction and suppression were performed. Hygromycin B, a known inducer of apoptosis, started the inhibition of T. ni cell growth at $200\;{\mu}/ml$ concentration. Furthermore, at $400\;{\mu}/ml$ concentration, DNA fragmentation was detected on day 2 of incubation. Although both dexamethasone and sodium butyrate inhibited T. ni cell growth, DNA fragmentation was not detected by both treatments. Also, when apoptosis induced T. ni cells with $200\;{\mu}/ml$ hygromycin B were treated with caspase inhibitor (Ac-DEVD-CHO), the apoptotsis was suppressed by 36%. In addition, N-acetylcysteine, another apoptosis repressor, also inhibited the apoptosis of T. ni cells. In order to express the anti-apoptosis gene (bcl-2), T. ni cells were transiently transformed with bcl-2 and its expression was confirmed by western blot analysis. These results showed the potential of developing new insect cell lines with suppressed apoptosis.

• Development and Reproduction
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• v.6 no.1
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• pp.25-30
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• 2002

Endocrine disruptors have been reported to adversely affect reproduction and embryonic development in wild animals. One of the major abnormalities observed during early embryonic development is cellular fragmentation. In this study, we exposed mouse preimplantation embryos to PCB, BPA and DDT in vivo or in vitro. Embryos exposed to endocrine disrupter showed a variety of morphological abnormalities such as fragmentation, irregular blastomeres and cracked empty zonae pellucidae. To investigate the levels of gene expression related which genes contribute to apoptosis in preimplantation mouse embryos, we carried out the reverse transcription polymerase chain reaction to assess mRNA levels far apoptotic gene. Bcl-2, bad and bax expression levels were compared between control group and endocrine disrupter treated group. Expression level of bcl-2 gene tended to be lower in the treated group than control while expression levels of bad and bax genes were higher in the treated group. Results of this study may provide a useful tool for rapidly screening developmental toxicants in preimplantation embryos exposed to endocrine disruptors in vivo or in vitro.

• The Journal of Korean Medicine
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• v.20 no.1 s.37
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• pp.91-105
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• 1999

The effects of Yinjin and Yinjinsaryongsangagambang on a DNA damaging agent, etoposide-induced apoptosis, cell viability, cell cycle progression, and mRNA expression of apoptosis-related genes of human hepatocyte cell line HepG2 were investigated using tryphan blue exclusion assay, MTT assay, flow cytometry, immunocytometric analysis of PCNA, and quantitative RT-PCR analysis. MTT assay showed that Yinjin and Yinjinsaryongsangagambang increases cellular viability of HepG2 cells in a dosage-dependent manner. Stimulation of cell cycle progression by Yinjin or Yinjinsaryongsangagambang was detected by flow cytometric analysis of the DNA content and immunocytometric analysis of PCNA expression. A significant reduction of a DNA-damaging agent, etoposide-induced apoptosis were found in both Yinjin and Yinjinsaryongsangagambang-treated cells in dosage-dependent manner. In overall, 3-fold reduction of apoptosis was recognized in $10.0\;{\mu}g/ml$ of Yinjin or Yinjinsaryongsangagambang-treated cells compared to untreated cells. Although the difference is not significant, Yinjinsaryongsangagambang showed slightly higher effect on the inhibition of apoptosis than Yinjin. From flow cytometric analysis of apoptosis, while 39.9% of untreated cells showed etoposide-induced apoptotic cell death, only 19.6% or 17.4% of Yinjin or Yinjinsaryongsangagambang-treated cells were fond at apoptotic sub G1 phase, respectively. Interestingly, strong induction of Gadd45-mRNA was observed from Yinjin or Yinjinsaryongsangagambang-treated cells. However, no changes in expression levels of p53 and Waf1 were detected, demonstrating that induction of Gadd45 mRNA expression by Yinjin or Yinjinsaryongsangagambang occurs by p53-independent mechanism. Marked mRNA inductions of two apoptosis-inhibiting genes, Bcl-2 and Bcl- XL, were found in both Yinjin or Yinjinsaryongsangagambang-treated HepG2 cells while no changes was detected in expression levels of an apoptosis-promoting gene, Bax.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.6
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• pp.329-335
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• 2006

This study was aimed to investigate the nitric oxide (NO)-induced cytotoxic mechanism in PC12 cells. Sodium nitroprusside (SNP), an NO donor, decreased the viability of PC12 cells in dose-and time-dependent manners. SNP enhanced the production of reactive oxygen species (ROS), and gave rise to apoptotic morphological changes including cell shrinkage, chromatin condensation, and DNA fragmentation. Expression of Bax was not affected, whereas Bcl-2 was downregulated in SNP-treated PC12 cells. SNP augmented the release of cytochrome c from mitochondria into cytosol and enhanced caspase -8, -9, and -3 activities. SNP upregulated both Fas and Fas-L, which are known to be components of death receptor assembly. These results suggest that NO induces apoptosis of PC12 cells through both mitochondria-and death receptor-mediated pathways mediated by ROS and Bcl-2 family.

• The Journal of Korean Obstetrics and Gynecology
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• v.24 no.4
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• pp.31-49
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• 2011

Objectives: This study was performed to assess the protective effect of Polygonum multiflorum(PM) on UVB-irradiated HaCaT Keratinocytes damage. Methods: The protective effects of Polygonum multiflorum(PM) were determined by UVB-irradiated HaCaT assay. We assessed protective effects of Polygonum multiflorum(PM) on LDH release and nitrite production from HaCaT. COX-2, Bcl-2, Bax, $TNF{\alpha}$, c-jun, c-fos, NF-${\kappa}B$, iNOS, Bcl-xL gene expression were determined in HaCaT using real-time PCR method. Results: 1. PM inhibited LDH Release in UVB-irradiated HaCaT Keratinocytes. 2. PM inhibited Nitrite Production in UVB-irradiated HaCaT Keratinocytes. 3. PM suppressed the Gene Expression of COX-2 in UVB-irradiated HaCaT Keratinocytes. 4. PM increased the Gene Expression of Bcl-2 in UVB-irradiated HaCaT Keratinocytes. 5. PM didn't increase the Gene Expression of Bax in UVB-irradiated HaCaT Keratinocytes. 6. PM suppressed the Gene Expression of $TNF{\alpha}$ in UVB-irradiated HaCaT Keratinocytes. 7. PM suppressed the Gene Expression of c-jun in UVB-irradiated HaCaT Keratinocytes. 8. PM suppressed the Gene Expression of c-fos in UVB-irradiated HaCaT Keratinocytes. 9. PM suppressed the Gene Expression of NF-${\kappa}B$ in UVB-irradiated HaCaT Keratinocytes. 10. PM suppressed the Gene Expression of i-NOS in UVB-irradiated HaCaT Keratinocytes. 11. PM didn't increase the Gene Expression of Bcl-xL in UVB-irradiated HaCaT Keratinocytes Conclusions: In conclusion, these results suggest that PM inhibited the cell damage in UVB-irradiated HaCaT.

• Molecules and Cells
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• v.45 no.6
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• pp.403-412
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• 2022

Hypoxia leads to significant cellular stress that has diverse pathological consequences such as cardiovascular diseases and cancers. MicroRNAs (miRNAs) are one of regulators of the adaptive pathway in hypoxia. We identified a hypoxia-induced miRNA, miR-34c, that was significantly upregulated in hypoxic human umbilical cord vein endothelial cells (HUVECs) and in murine blood vessels on day 3 of hindlimb ischemia (HLI). miR-34c directly inhibited BCL2 expression, acting as a toggle switch between apoptosis and autophagy in vitro and in vivo. BCL2 repression by miR-34c activated autophagy, which was evaluated by the expression of LC3-II. Overexpression of miR-34c inhibited apoptosis in HUVEC as well as in a murine model of HLI, and increased cell viability in HUVEC. Importantly, the number of viable cells in the blood vessels following HLI was increased by miR-34c overexpression. Collectively, our findings show that miR-34c plays a protective role in hypoxia, suggesting a novel therapeutic target for hypoxic and ischemic diseases in the blood vessels.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.9 no.1
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• pp.15-37
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• 2003

Objective: We are aimed to identify anti-tumor effects of Curcuma longa L. on the stomach cancer cells through molecular biologic methods. Material & Methods: We used AGS as human stomach cancer cells obtained from American Type Culture Collection. The boiled extract of Curcuma longa L. $5{\mu}l$ (Sample I), $10{\mu}l$ (Sample II) was treated to cultural media(ml) for 0, 6, 12, 24, 48 hours. We measured the killing effect on stomach cancer cells through Trypan blue exclusion test and the suppressive effect on viability of stomach cancer cells via MTT assay. For identification of its anticancer mechanism, the revelation of Bcl-2, Bcl-XL, and Bax which are genes related to apoptosis using the quantitative RT-PCR, change of mitochondria membrane permeability and membrane potential via flow cytometry, the cycle of cell mitosis, caspase cleavage and annexin V staining were examined. Results: 1. showed significant killing effect on stomach cancer cell than the control group with a time(6 hours later) and density dependent manner, which was statistical significance. 2. Extract of Curcuma longa L. showed suppressive effect on viability of stomach cancer cells that each test groups had more suppressive effects on viability of stomach cancer cells than the control group with a time(6 hours later), which was statistical significance.(p<0.05) 3. In the test about the revelation of genes related to apoptosis, the revelation of Bcl-2 and Bcl-XL decreased with a density manner which was statistical significance. but the revelation of Bax was not changed with statistical significance. 4. Extract of Curcuma longa L. caused apoptosis by decreasing the absorbance of mitochondria with statistical significance, and also induced apoptosis by decreasing the membrane potential of mitochondria. 5. Extract of Curcuma longa L. destructed the cell cycle of cell mitosos. 6. Cell apoptosis was induced by extract of Curcuma longa L. certificated by method of caspase cleavage and annexin V staining. Conclusion: This experiment showed that Curcuma longa L. has anti-tumor effect with statistical significance. This is in vitro experiment and basic experiment on Curcuma longa L.. We hope more progressive research on Curcuma longa L. will go on and its anti-tumor effects will be more practically identified.

• Neonatal Medicine
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• v.17 no.1
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• pp.44-52
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• 2010

Purpose : The aim of this study was to develop a model for necrotizing enterocolitis (NEC) in the neonatal rat using endotoxin and hypoxia, a plausible insult in a neonatal intensive care and to investigate the role of apoptosis as the underlying mechanism. Methods : Newborn rats were given oral endotoxin and intermittent 8% hypoxia$\pm$caspase inhibitor. The intestinal histology was evaluated using hematoxylin-eosin staining. Apoptosis was analyzed with TUNEL staining and by measuring the caspase 3 activity in the intestinal lysates. IEC-6 cells were assessed for apoptosis and the expression of Bax, Bcl-2, Fas and FasL was measured after treatment with endotoxin and hypoxia. Results : Oral endotoxin (5 mg/kg) and exposure to 8% hypoxia of 60-min duration twice induced human NEC-like lesions in the rat intestine. Intestinal tissue revealed increased apoptosis and caspase-3 activity. After caspase inhibitor treatment, the grades of both apoptosis and NEC were significantly reduced. IEC-6 cells exhibited increased apoptosis and caspase 3 activity after endotoxin and hypoxia treatment and significantly increased Bax/Bcl- 2 ratio compared to control cells. Conclusion : This neonatal rat model of NEC which was induced by oral endotoxin and intermittent hypoxia showed increased apoptosis of intestinal epithelial cells that was mediated by caspase 3 activation. Our model has a advantage in the study of NEC because the use of much more clinically plausible insults may provide a suitable model for the investigation of its pathophysiology and therapeutic trials.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.95-103
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• 2019

Periodontal inflammation, a major kind of periodontal diseases, is characterized to bleed, pain, and teeth loss, and it is resulted from oxidative stress. Membrane-free stem cell extract could avoid the immunogencity rejection by removal of cell membrane. In the present study, we investigated the protective effect of membrane-free stem cell extract from oxidative stress-induced periodontal inflammation in human periodontal ligament fibroblasts (HPLF). In the cell viability measurement, membrane-free stem cell extract showed significant increase of cell viability, compared with the $H_2O_2$-treated control group. To further investigation of molecular mechanisms, we measured inflammation and apoptosis related protein expressions. Membrane-free stem cell extract attenuated inflammation-related protein expressions such as nuclear factor kappa light chain enhancer of activated B cells, inducible nitric oxide synthase, and interleukin-6. In addition, the treatment of membrane-free stem cell extract decreased apoptotic protein expressions such as cleaved caspase-9, -3, poly (ADP-ribose) polymerase, and B-cell lymphoma 2 (Bcl-2)-associated X protein/Bcl-2 ratio in the $H_2O_2$-treated HPLF cells. In conclusion, membrane-free stem cell extract exhibited anti-oxidative stress effects by regulation of inflammation and apoptosis in HPLF, suggesting that it could be used as the treatment agents for periodontal inflammatory disease.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.295-295
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• 2012

염소와 불소 혼합가스와 펄스 직류 전원 플라즈마를 이용하여 GaAs/$Al_{0.2}Ga_{0.8}As$의 선택적 식각을 연구하였다. 식각 주요 공정 변수는 혼합 플라즈마에서 불소 가스의 유량(0~50%) 이었다. 다른 공정 조건은 공정 압력, 펄스 파워, 펄스 주파수, 리버스 시간이 이 있다. 저진공(~100 mTorr) 플라즈마에 대한 연구로 한정하여 기계적 펌프만을 사용하여 공정을 진행하였다. 오실로스코프(Oscilloscope) 데이터에 의하면 가스의 조성 변화에도 척에 걸리는 입력 전압과 전류가 거의 변화가 없었다. $BCl_3/SF_6$플라즈마에서 $SF_6$가스가 10%의 조성에서 GaAs와 $Al_{0.2}Ga_{0.8}As$의 식각 선택비가 약 50:1로 우수한 결과를 나타내었다. 혼합 플라즈마에서 $SF_6$가스의 증가는 GaAs의 식각율과 선택도를 감소시켰다. 그리고 불소 성분 가스의 조성비가 일정량 이상일 경우에는 GaAs와 $Al_{0.2}Ga_{0.8}As$가 거의 식각되지 않았다. 위의 결과들을 종합적으로 보면 펄스 직류 전원 $BCl_3/SF_6$플라즈마에서 불소의 조성비는 GaAs의 선택적 식각에서 중요한 역할을 함을 알 수 있었다.