• 통합자연과학논문집
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• 제7권1호
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• pp.25-38
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• 2014

Amyloid-${\beta}$-peptide ($A{\beta}$) is important in the pathogenesis of Alzheimer's disease (AD). Calpain ($Ca^{2+}$-dependent protease) and caspase-8 (the initiating caspase for the extrinsic, receptor-mediated apoptosis pathway) have been implicated in $AD/A{\beta}$ toxicity. We found that $A{\beta}$ promoted degradation of calpastatin (the specific endogenous calpain inhibitor); calpastatin degradation was prevented by inhibitors of either calpain or caspase-8. The results implied a cross-talk between the two proteases and suggested that one protease was responsible for the activity of the other one. In neuron-like differentiated PC12 cells, calpain promotes active caspase-8 formation from procaspase-8 via the $A{\beta}$ and CD95 pathways, along with degradation of the procaspase-8 processing inhibitor caspase-8 (FLICE)-like inhibitory protein, short isoform (FLIPS). Inhibition of calpain (by pharmacological inhibitors and by overexpression of calpastatin) prevents the cleavage of procaspase-8 to mature, active caspase-8, and inhibits FLIPS degradation in the $A{\beta}$-treated and CD95-triggered cells. Increased cellular Ca2+ per se results in calpain activation but does not lead to caspase-8 activation or FLIPS degradation. The results suggest that procaspase-8 and FLIPS association with cell membrane receptor complexes is required for calpain-induced caspase-8 activation. The results presented here add to the understanding of the roles of calpain, caspase- 8, and CD95 pathway in $AD/A{\beta}$ toxicity. Calpain-promoted activation of caspase-8 may have implications for other types of CD95-induced cell damage, and for nonapoptotic functions of caspase-8. Inhibition of calpain may be useful for modulating certain caspase-8-dependent processes.

• 생명과학회지
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• 제13권1호
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• pp.118-127
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• 2003

Phenylalanine의 구조유사체인 p-fluotophenylalanine (FPA)은 인체 급성백혈병세포주인 Jurkat T 세포의 세포자살을 유도한다. FPA에 의한 세포자살에 미치는 Bcl-2 또는 Bcl-xL의 영향을 조사하기 위해, Bcl-2 또는 Bcl-xL을 stable transfection하거나 empty vectors만을 Transfection한 Jurkat 세포를 이용하여 FPA의 세포독성과 FPA에 의한 세포내 세포자살 신호전달경로를 비교 분석하였다. Jurkt T 세포에 0.63∼3.0 mLf의 FPA를 처리하였을 때 세포의 생육도는 농도에 비례하여 감소하였다. 또한 세포자살관련 DNA fragmentation, caspase-8 activatoin, Bid cleavage, mitochondria로 부터의 cytochrome c 방출, caspase-9 및 -3 activation, PARP degradation 등이 유도되었다. 한편, FPA에 의해 유도되는 이러한 일련의 생화학적 현상들은 Bcl-2 또는 Bcl-xL의 overexpression에 의해 현저히 저해되었다. 이상의 결과들은 caspase-8 activation, Bid cleavage, mitochondnal cytochrome c 방출에 의해 활성화되는 casuase cascade 등의 현상이, Bcl-2 또는 Bcl-xL에 의해 억제됨을 나타내며 FPA에 의해 유도되는 세포자살에 필요한 과정임을 시사한다.

• BMB Reports
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• 제37권4호
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• pp.445-453
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• 2004

We identified apoptosis as being a significant mechanism of toxicity following the exposure of HeLa cell cultures to abrin holotoxin, which is in addition to its inhibition of protein biosynthesis by N-glycosidase activity. The treatment of HeLa cell cultures with abrin resulted in apoptotic cell death, as characterized by morphological and biochemical changes, i.e., cell shrinkage, internucleosomal DNA fragmentation, the occurrence of hypodiploid DNA, chromatin condensation, nuclear breakdown, DNA single strand breaks by TUNEL assay, and phosphatidylserine (PS) externalization. This apoptotic cell death was accompanied by caspase-9 and caspase-3 activation, as indicated by the cleavage of caspase substrates, which was preceded by mitochondrial cytochrome c release. The broad-spectrum caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone (zVAD-fmk), prevented abrin-triggered caspase activation and partially abolished apoptotic cell death, but did not affect mitochondrial cytochrome c release. These results suggest that the release of mitochondrial cytochrome c, and the sequential caspase-9 and caspase-3 activations are important events in the signal transduction pathway of abrin-induced apoptotic cell death in the HeLa cell line.

• Journal of Microbiology and Biotechnology
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• 제12권6호
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• pp.950-956
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• 2002

The antitumor activity of the insect pathogenic fungus Paecilomyces japonica has been attributed to apoptotic cell death. However, the mechanism underlying the induced apoptosis has not yet been elucidated. In this study, we for the first time show that mitochondria-dependent caspase-3 activation were associated with the apoptotic activity of P. japonica in human acute leukemia Jurkat T cells. When Jurkat T cells were treated with the ethyl acetate extract of P japonica at concentrations ranging from $2-6{\mu}g/ml$, apoptotic cell death. accompanied by several biochemical events such as caspase-9 activation, caspase-3 activation, degradation of poly (ADP-ribose) polymerase (PARP), and apoptotic DNA fragmentation, was induced in a dose-dependent manner. In addition, the release of cytochrome c from mitochondria was detected. Under these conditions, the expression of Fas and Fas-ligand (FasL) remained unchanged. Ethyl acetate extract-induced mitochondrial cytochrome c release, caspase-3 activation, PARP cleavage, and apoptotic DNA fragmentation were suppressed by the ectopic expression of Bcl-2, which is known to block mitochondrial cytochrorme c release. Accordingly, these results demonstrate that P. japonica-induced apoptotic cell death is mediated by a cytochrome c-dependent caspase-3 activation pathway that can be interrupted by Bcl-2.

• BMB Reports
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• 제50권10호
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• pp.510-515
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• 2017

Triglyceride (TG) accumulation causes macrophage cell death, which affects the development of atherosclerosis. Here, we examined whether caspase-2 is implicated in TG-induced macrophage cell death. We found that caspase-2 activity is increased in TG-treated THP-1 macrophages, and that inhibition of caspase-2 activity drastically inhibits TG-induced cell death. We previously reported that TG-induced macrophage cell death is triggered by caspase-1, and thus investigated the relationship between caspase-2 and caspase-1 in TG-induced macrophage cell death. Inhibition of caspase-2 activity decreased caspase-1 activity in TG-treated macrophages. However, caspase-1 inhibition did not affect caspase-2 activity, suggesting that caspase-2 is upstream of caspase-1. Furthermore, we found that TG induces activation of caspase-3, -7, -8, and -9, as well as cleavage of PARP. Inhibition of caspase-2 and -1 decreased TG-induced caspase-3, -7, -8, and -9 activation and PARP cleavage. Taken together, these results suggest that TG-induced macrophage cell death is mediated via the caspase-2/caspase-1/apoptotic caspases/PARP pathways.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.325.2-325.2
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• 2002

We investigated the effect of bovine lactoferricin (Lfcin-B) on cell cycle regulation and caspase activation in tumor cells. Treatment with Lfcin-B resulted in the production of intracellular reactive oxygen species (ROS) during apoptosis of THP-1 cells. Biochemical analysis revealed that Lfcin-B-induced apoptosis. the cell cycle arrest and caspase activation were completely abrogated by addition of an antioxidant such as N-acetylcysteine(NAC). (omitted)

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.107.1-107.1
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• 2003

20-O-(${\beta}$-D-Glucopyranosyl)-20(S)-protopanaxadiol (IH901), an intestinal bacterial metabolite of ginseng saponins formed from ginsenosides Rb1, Rb2 and Rc, is suggested to be a potential chemopreventive agent. Here we show that IH901 induces apoptosis in human hepatoblastoma HepG2 cells. IH901 led to an early activation of procaspase-3 (6 h posttreatment), and the activation of caspase-8 became evident only later (18 h posttreatment). Caspase activation was a necessary requirement for apoptosis because caspase inhibitors significantly inhibited cell death by IH901. (omitted)

• 약학회지
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• 제43권3호
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• pp.385-390
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• 1999

Camptothecin (CPT) has been known to induce apoptosis in various cancer cell lines. To examine the intracellular apoptotic death signal initiated by CPT, we investigated the possible connection between caspase-3 activation and GSH depletion during CPT-induced apoptosis in HL-60 cells. Treatment of cells with $1{\;}{\mu}M$ CPT induced PARP cleavage accompanied by DNA fragmentation. z-VAD-fmk, a caspase-3 inhibitor, blocked the CPT-induced DNA fragmentation. Pretreatment of cells with N-acetylcysteine, a precursor of GSH biosynthesis, failed to inhibit CPT-induced PARP celavage and DNA gragmenatation. No significant changes in GSH depletion is not essential for caspase activation during CPT-induced apoptosis. We also investigated whether CPT-induced apoptosis is associated with changes of the levels of Bax and Bcl-2, two proteins involved in the control of apoptosis. Bcl-2 levels exhibited a late decrease compared with the kinetics of DNA fragmentation, whereas Bax levels increased more rapidly after CPT treatment. These results suggest that Bax plays more important role than Bcl-2 in inducing DNA fragmentation and may function upsteam of proteolytic activation of caspase-3 pathway in CPT-induced apoptosis.

• Archives of Pharmacal Research
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• 제27권8호
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• pp.834-839
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• 2004

In human neuroblastoma SK-N-BE(2) cells undergoing apoptotic death induced by ginsenos-ide Rh2, a dammarane glycoside that was isolated from Panax ginseng C. A. Meyer, caspase-1 and caspase-3 were activated. The expression of Bax was increased in the cells treated with ginsenoside Rh2, whereas Bcl-2 expression was not altered. Treatment with caspase-1 inhibi-tor, Ac-YVAD-CMK, or caspase-3 inhibitor, Z-DEVD-FMK, partially inhibited ginsenoside Rh2-induced cell death but almost suppressed the cleavage of the 116 kDa PARP into a 85 kDa fragment. When the levels of p53 were examined in this process, p53 accumulated rapidly in the cells treated early with ginsenoside Rh2. These results suggest that activation of caspase-1 and -3 and the up-regulation of Bax are required in order for apoptotic death of SK-N-BE(2) cells to be induced by ginsenoside Rh2, and p53 plays an important role in the pathways to promote apoptosis.

• 한국수정란이식학회지
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• 제27권3호
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• pp.183-187
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• 2012

Adult stem cell transplantation has been increased every year, because of the lack of organ donors for regenerative medicine. Therefore, development of reliable and safety cryopreservation and bio-baking method for stem cell therapy is urgently needed. The present study investigated safety of dimethyl sulfoxide (DMSO) such as common cryoprotectant on porcine bone marrow derived mesenchymal stem cells (pBM-MSCs) by evaluating the activation of Caspase-3 and -7, apoptosis related important signal pathway. pBM-MSCs used for the present study were isolated density gradient method by Ficoll-Paque Plus and cultured in A-DMEM supplemented 10% FBS at $38.5^{\circ}C$ in 5% $CO_2$ incubator. pBM-MSCs were cryopreserved in A-DMEM supplemented either with 5%, 10% or 20% DMSO by cooling rate at $-1^{\circ}C$/min in a Kryo 360 (planner 300, Middlesex, UK) and kept into $LN_2$. Survival rate of cells after thawing did not differ between 5% and 10% DMSO but was lowest in 20% DMSO by 0.4% trypan blue exclusion. Activation of Caspase-3 and -7 by Vybrant FAM Caspase-3 and -7 Assay Assay Kit (Molecular probes, Inc.OR, USA) was analyzed with a flow cytometer. Both of cryopreserved and control groups (fresh pBM-MSCs) were observed after the activation of Caspase-3 and -7. The activation did not differ between 5% and 10% DMSO, but was observed highest in 20% DMSO. Therefore 5% DMSO can be possibly used for cell cryopreservation instead of 10% DMSO.