• 한국발생생물학회지:발생과생식
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• 제23권1호
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• pp.43-54
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• 2019

We examined the effects of endoplasmic reticulum (ER) stress inhibitor treatment during the micromanipulation of porcine somatic cell nuclear transfer (SCNT) on the in vitro development of SCNT embryos. ER stress inhibitors such as salubrinal (200 nM) and tauroursodeoxycholic acid (TUDCA; $100{\mu}M$) were added to the micromanipulation medium and holding medium. The expression of X-box binding protein 1 (Xbp1), ER-stress-associated genes, and apoptotic genes in SCNT embryos was confirmed at the one-cell and blastocyst stages. Levels of Xbp1 splicing and expression of ER-stress-associated genes in SCNT embryos at the one-cell stage decreased significantly with TUDCA treatment (p<0.05). The expression of ER-stress-associated genes also decreased slightly with the addition of both salubrinal and TUDCA (Sal+TUD). The expression levels of caspase-3 and Bcl2-associated X protein (Bax) mRNA were also significantly lower in the TUDCA and Sal+TUD treatments (p<0.05). At the blastocyst stage, there were no differences in levels of Xbp1 splicing, and transcription of ER-stress-associated genes and apoptosis genes between control and treatment groups. However, the blastocyst formation rate (20.2%) and mean blastocyst cell number ($63.0{\pm}7.2$) were significantly higher (p<0.05) for embryos in the TUDCA treatment compared with those for control (12.6% and $41.7{\pm}3.1$, respectively). These results indicate that the addition of ER-stress inhibitors, especially TUDCA, during micromanipulation can inhibit cellular damage and enhance in vitro development of SCNT embryos by reducing stress levels in the ER.

• 생명과학회지
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• 제18권11호
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• pp.1513-1520
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• 2008

4-Hydroxynonenal (4-HNE)는 세포내 레독스의 균형을 깨뜨려 혈관 기능 손상을 일으킨다. 본 연구자들은 HNE의 축적이 야기하는 혈관 기능 손상기전을 더 잘 이해하기 위하여 혈관 내피 세포의 미토콘드리아 세포사 메커니즘을 규명하였다. HNE를 처리한 세포에서는 미토콘드리아 막전위 소실과 그에 따른 cytochrome C의 방출이 유도되었으며, Bax의 증가 및 Bcl-2의 감소가 관찰되었다. ROS 제거제인 NAC와 peroxynitrite 제거제인 페니실라민은 HNE가 유도하는 ROS 생성을 차단하여 cytochrome C 방출과 세포사를 억제하였다. 세포에 HNE와 zVAD-fmk (caspase 저해제)를 같이 처리하면 HNE가 유도하는 세포사를 억제하지 못하는데 이는 HNE에 의한 세포사가 caspase에 비의존적 단계일 가능성을 시사하였다. 위의 결과들은 HNE가 유도하는 혈관 내피 세포의 세포사 매커니즘은 미토콘드리아 막전위의 탈분극에 의해 촉발되며 이는 혈관계 항상성의 악화와 노화에 의해 수반되는 혈관기능 손상을 유도할 것으로 사료된다.

• 동의생리병리학회지
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• 제21권5호
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• pp.1226-1232
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• 2007

Phellinus linteus is a well-known Oriental medicinal fungus that has various biological activities, including immunomodulatory and anti-tumor activities, the mechanisms of which are poorly understood. In the present study, we investigated the anti-proliferative activity of the methanol extract of P. linteus-Barley corn (MEPLB) in human lekemic U937 cells. It was found that exposure of U937 cells to MEPLB resulted morphological change and growth inhibition in a dose-dependent manner as measured by trypan blue count and MTT assay. Upon treatment with MEPLB, U937 cells developed many of the hallmark features of apoptosis, including condensation of chromatin and an increase in the sub-G1 population suggesting that the anti-proliferative effect of MEPLB is associated with the induction of apoptosis. The anti-proliferative and apoptotic effects of MEPLB were connected with a marked induction of the pro-apoptotic Bax and cyclin-dependent kinase (Cdk) inhibitor p21 in a p53-independent manner. Additionally, MEPLB treatment significantly induced the caspase-3 activity in U937 cells. Taken together, the present results suggest that apoptotic signals evoked by MEPLB in human leukemic U937 cells may converge caspase-3 activation through an up-regulation of Bax rather than a down-regulation of Bcl-2 or Bel-xL.

• 생명과학회지
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• 제23권3호
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• pp.389-398
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• 2013

Platycodin D는 도라지(Platycodon grandiflorum)의 뿌리인 길경(Platycodi Radix)에 함유된 은 triterpene saponin의 일종으로 다양한 약리효능이 있는 것으로 알려져 있다. 본 연구에서는 다양한 암세포 중 platycodin D의 항암활성 감수성이 가장 높았던 인체 혈구암 U937 세포를 대상으로 platycodin D 처리에 따른 apoptosis 유발기전에 대하여 조사하였다. 본 연구의 결과에 의하면 U937 세포에서 platycodin D 처리에 의한 증식억제는 apoptosis 유발과 밀접한 연관이 있음을 알 수 있었다. 이러한 platycodin D에 의한 apoptosis 유발은 pro-apoptotic Bax의 발현 증가와 연관된 미토콘드리아 막 전위의 소실 및 caspase-3의 활성화와 기질단백질들의 분해에 의한 것임을 알 수 있었으며, IAP family 인자들의 발현 감소가 caspase의 활성 증가에도 영향을 미친 것으로 추정된다. 또한 z-DEVD-fmk 선처리에 의하여 platycodin D에 의하여 유발된 apoptosis가 유의적으로 억제되었기에, platycodin D 처리에 의하여 유발되는 apoptosis는 미토콘드리아 경로에 의하여 조절되며, caspase-3의 활성화가 핵심적인 역할을 한 것으로 생각된다.

• Biomolecules & Therapeutics
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• 제17권1호
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• pp.17-24
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• 2009

Histone deacetylase (HDAC) inhibitors are a promising class of anticancer agents that inhibit cancer cell growth in vitro and in vivo. Previous report has shown that apicidin inhibited SK-OV-3 cells proliferation and down-regulation of cyclin B1 and CDK1, and up-regulation of $p21^{WAF1}$ and p27. However, the mechanism of apicidin-mediated apoptotic cell death is not clearly understood. For this study, we investigated the mechanism of apoptotic pathway induced by apicidin in human ovarian cancer cell. We found that SK-OV-3 cells treated with apicidin caused an increase in the percentage of cells in the G2/M phase, which preceded apoptosis characterized by the appearance of cells with sub-G1 population. To further investigate the mechanism of apoptosis induction by apicidin, we measured TUNEL assay, poly-ADP ribose polymerase (PARP) cleavage, and caspase activity in SK-OV-3 cells treated with apicidin for 48 h. Apicidin significantly enhanced apoptosis as measured by TUNEL positive apoptotic cells, PARP cleavage, and increased Bax/Bcl-2 ratio. Induction of apoptosis was confirmed by the release of cytochrome c to cytosol. Our data suggest that apicidin-induced apoptosis in SK-OV-3 cells was accompanied by caspase-3 activation and the increase in Bax/Bcl-2 ratio. These data suggest that apicidin may be effective in the treatment of ovarian cancer through activation of intrinsic apoptotic pathway.

• Molecules and Cells
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• 제41권3호
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• pp.234-243
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• 2018

In recent years, the interest towards the relationship between incretins and bone has been increasing. Previous studies have suggested that glucagon-like peptide-1 (GLP-1) and its receptor agonists exert beneficial anabolic influence on skeletal metabolism, such as promoting proliferation and differentiation of osteoblasts via entero-osseous-axis. However, little is known regarding the effects of GLP-1 on osteoblast apoptosis and the underlying mechanisms involved. Thus, in the present study, we investigated the effects of liraglutide, a glucagon-like peptide-1 receptor agonist, on apoptosis of murine MC3T3-E1 osteoblastic cells. We confirmed the presence of GLP-1 receptor (GLP-1R) in MC3T3-E1 cells. Our data demonstrated that liraglutide inhibited the apoptosis of osteoblastic MC3T3-E1 cells induced by serum deprivation, as detected by Annexin V/PI and Hoechst 33258 staining and ELISA assays. Moreover, liraglutide upregulated Bcl-2 expression and downregulated Bax expression and caspase-3 activity at intermediate concentration (100 nM) for maximum effect. Further study suggested that liraglutide stimulated the phosphorylation of AKT and enhanced cAMP level, along with decreased phosphorylation of $GSK3{\beta}$, increased ${\beta}-catenin$ phosphorylation at Ser675 site and upregulated nuclear ${\beta}-catenin$ content and transcriptional activity. Pretreatment of cells with the PI3K inhibitor LY294002, PKA inhibitor H89, and siRNAs GLP-1R, ${\beta}-catenin$ abrogated the liraglutide-induced activation of cAMP, AKT, ${\beta}-catenin$, respectively. In conclusion, these findings illustrate that activation of GLP-1 receptor by liraglutide inhibits the apoptosis of osteoblastic MC3T3-E1 cells induced by serum deprivation through $cAMP/PKA/{\beta}-catenin$ and $PI3K/Akt/GSK3{\beta}$ signaling pathways.

• Journal of Acupuncture Research
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• 제23권2호
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• pp.47-59
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• 2006

We previously found that cobrotoxin inhibited $NF-{\kappa}B$ activity by reacting with signal molecules of $NF-{\kappa}B$ which is critical contributor in cancer cell growth by induction of apoptotic cell death. We here investigated whether cobrotoxin inhibits cell growth of human prostate cancer cells through induction of apoptotic cell death, which is related with the suppression of the $NF-{\kappa}B$ activity. Cobrotoxin $(0{\sim}8\;nM)$ inhibited prostate cancer cell growth through increased apoptosis in a dose dependent manner. Cobrotoxin inhibited DNA binding activity of $NF-{\kappa}B$, an anti-apoptotic transcriptional factor. Consistent with the induction of apoptosis and inhibition of $NF-{\kappa}B$, cobrotoxin increased the expression of pro-apoptotic proteins caspase 3. Cobrotoxin, a venom of Vipera lebetina turanica, is a group of basicpeptides composed of 233 amino acids with six disulfide bonds formed by twelve cysteins. NF-kB is activated by subsequent release of inhibitory IkB and translocation of p50. Since sulfhydryl group is present in kinase domain of p50 subunit of NF-kB, cobrotoxin could modify NF-kB activity by protein-protein interaction. And Cobrotoxin down regulated Akt signals. Salicylic acid as a reducing agent of Sulf-hydryl group and LY294002 as a Akt inhibitor abrogated cobrotoxin-induced cell growth and DNA binding activity of $NF-{\kappa}B$. These findings suggest that nano to pico molar range of cobrotoxin could inhibit prostate cancer cell growth, and the effect may be related with the induction of apoptotic cell death through Akt dependent inhibition of $NF-{\kappa}B$ signal.

• Journal of Photoscience
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• 제9권2호
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• pp.485-487
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• 2002

Cells receive signals for survival as well as death, and the balance between the two ultimately determines the fate of the cells. UV-triggered apoptotic signaling has been well documented, whereas UV-induced survival effects have received little attention. We have reported previously that UVB irradiation prevented apoptosis, which was partly dependent on activation of the phosphatidylinositol 3-kinase (PI3-kinase)/ Akt pathway. In this study, anti-apoptotic effects of UV with different wavelength ranges, UVA, UVB and UVC, were examined. NIH3T3 cells showed apoptotic cell death by detachment from the extracellular matrix under serum-free conditions, which was prevented by all wavelengths. However, the effect of UVA was less than those of UVB and UVC. Reduction of mitochondrial transmembrane potential and activation of caspase-9 and -3 were suppressed by all three wavelengths of UV, showing wavelength-dependent effects as mentioned above. The PI3-kinase inhibitor wortmannin partially inhibittrl the UVB and UVC-induced suppression of apoptosis, but not the inhibitoty effect of UVA. The Akt phosphotylation by UVB and UVC was completely inhibittrl by addition of wortmannin, but that by UVA was not P38 MAP kinase inhibitor SB203580 partially inhibited the UVB and UVC-induced suppression of apoptosis and Akt phosphotylation, and completely inhibited UVA-induced those. These results suggested the existence of two different survival pathways leading to suppression of apoptosis, one for UVA that is independent of the PI3-kinase/Akt pathway and dependent on p38 MAP kinase, and the other for UVB and UVC that is dependent on both pathways.

• 대한한방부인과학회지
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• 제18권1호
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• pp.29-44
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• 2005

To address the ability of Herba Portulacae(HP) to induce cell death, we investigated the effect of HP on cell viability. Twenty-four hours later, loss of viability occurred following HP exposure in a dose-dependent manner. The treatment of HP, a commonly used herb formulation in Korea, Japan and China, caused a decrease in cell viability. HP also resulted in apoptotic morphology a brightly blue-fluorescent condensed nuclei by Hoechst 33258-staining, and reduction of cell volume. Our results show that 2mg/ml HP induces mitochondria membrane potential collapse. Immunoblotting data also shows that the expression of Bcl-2, antiaoptotic protein, decrease by the addition of HP. This GFP-Bax overexpression system shows that an important pro-apoptotic Bcl-2-family protein, Bax is translocated to mitochondria by the addition of 2mg/ml HP. Inerestingly, MAPK inhibitor study shows that p38 MAPK inhibitor, SB203580 inhibits HP-induced cell death and caspase-3 activation in HP-treated HeLa cells. Furthermore, HP transiently but significantly induces p38 activation. But P38 MAPK inhibitor does not have any effect on the translocation of Bax. Considering these results, HP induces apoptosis via p38 MAPK activation. But the pathway does not involve the translocation of Bax.

• International Journal of Oral Biology
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• 제45권4호
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• pp.169-178
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• 2020

L-ascorbic acid (L-AA; vitamin C) induces apoptosis in cancer cells. This study aimed to elucidate the molecular mechanisms of L-AA-induced apoptosis in human laryngeal epidermoid carcinoma Hep-2 cells. L-AA suppressed the viability of Hep-2 cells and induced apoptosis, as shown by the cleavage and condensation of nuclear chromatin and increased number of Annexin V-positive cells. L-AA decreased Bcl-2 protein expression but upregulated Bax protein levels. In addition, cytochrome c release from the mitochondria into the cytosol and activation of caspase-9, -8, and -3 were enhanced by L-AA treatment. Furthermore, apoptosis-inducing factor (AIF) and endonuclease G (EndoG) were translocated into the nucleus during apoptosis of L-AA-treated Hep-2 cells. L-AA effectively inhibited the constitutive nuclear factor-κB (NF-κB) activation and attenuated the nuclear expression of the p65 subunit of NF-κB. Interestingly, L-AA treatment of Hep-2 cells markedly activated Akt and mitogen-activated protein kinase (MAPK; extracellular signal-regulated kinase 1/2, p38, and c-Jun N-terminal kinase [JNK]) and and LY294002 (Akt inhibitor), SB203580 (p38 inhibitor) or SP600125 (a JNK inhibitor) decreased the levels of Annexin V-positive cells. These results suggested that L-AA induces the apoptosis of Hep-2 cells via the nuclear translocation of AIF and EndoG by modulating the Bcl-2 family and MAPK/Akt signaling pathways.